The injection to emerging adult workerbees with fluvalinate doses ranging from 1 femtomol to 1 nanomol per individual resulted in a reduction of haemolymph carbohydrate concentrations, particularly at the lowest dose ...The injection to emerging adult workerbees with fluvalinate doses ranging from 1 femtomol to 1 nanomol per individual resulted in a reduction of haemolymph carbohydrate concentrations, particularly at the lowest dose 1 hour after injections. At the same time, a large increase was observed for triacylglycerols and to a much lesser extent for steroids and phospholipids with 0.1 picomol per bee. By contrast, fatty acids, steroids and triacylglycerols exhibited a depress at the higher dose. Most responses were thus biphasic, showing that much attention should be paid to the effects of very low doses of pesticide.展开更多
X-ray excited photodynamic therapy(X-PDT)is the bravo answer of photodynamic therapy(PDT)for deep-seated tumors,as it employs X-ray as the irradiation source to overcome the limitation of light penetration depth.Howev...X-ray excited photodynamic therapy(X-PDT)is the bravo answer of photodynamic therapy(PDT)for deep-seated tumors,as it employs X-ray as the irradiation source to overcome the limitation of light penetration depth.However,high X-ray irradiation dose caused organ lesions and side effects became the major barrier to X-PDT application.To address this issue,this work employed a classic-al co-precipitation reaction to synthesize NaLuF_(4):15%Tb^(3+)(NLF)with an average particle size of(23.48±0.91)nm,which was then coupled with the photosensitizer merocyanine 540(MC540)to form the X-PDT system NLF-MC540 with high production of singlet oxygen.The system could induce antitumor efficacy to about 24%in relative low dose X-ray irradiation range(0.1-0.3 Gy).In vivo,when NLF-MC540 irradiated by 0.1 Gy X-ray,the tumor inhibition percentage reached 89.5%±5.7%.The therapeutic mechanism of low dose X-PDT was found.A significant increase of neutrophils in serum was found on the third day after X-PDT.By immunohistochemical staining of tumor sections,the Ly6G^(+),CD8^(+),and CD11c^(+)cells infiltrated in the tumor microenvironment were studied.Utilizing the bilat-eral tumor model,the NLF-MC540 with 0.1 Gy X-ray irradiation could inhibit both the primary tumor and the distant tumor growth.De-tected by enzyme linked immunosorbent assay(ELISA),two cytokines IFN-γand TNF-αin serum were upregulated 7 and 6 times than negative control,respectively.Detected by enzyme linked immune spot assay(ELISPOT),the number of immune cells attributable to the IFN-γand TNF-αlevels in the group of low dose X-PDT were 14 and 6 times greater than that in the negative control group,respectively.Thus,it conclude that low dose X-PDT system could successfully upregulate the levels of immune cells,stimulate the secretion of cy-tokines(especially IFN-γand TNF-α),activate antitumor immunity,and finally inhibit colon tumor growth.展开更多
The present paradigm of radiation-induced carcinogenesis has been based on somatic mutation theory initiating a mutation in somatic cells derived from DNA damage by ionizing radiation. A non-threshold linear model has...The present paradigm of radiation-induced carcinogenesis has been based on somatic mutation theory initiating a mutation in somatic cells derived from DNA damage by ionizing radiation. A non-threshold linear model has been assumed from high doses to low doses. As an alternative to this, we are proposing a new model that epigenetic changes induced by low dose irradiation may be a first step of carcinogenesis. Our preliminary data suggesting the epigenetic nature and reports on various stress response to ionizing radiation are presented.展开更多
AIM:To describe the outcome of using low-dose laser cycloplasty(LCP)in chronic angle-closure glaucoma(CACG).METHODS:A retrospective case series.Medical charts of CACG patients who underwent LCP in the Eye Hospital of ...AIM:To describe the outcome of using low-dose laser cycloplasty(LCP)in chronic angle-closure glaucoma(CACG).METHODS:A retrospective case series.Medical charts of CACG patients who underwent LCP in the Eye Hospital of Wenzhou Medical University were reviewed.The main outcomes included intraocular pressure(IOP),the number of glaucoma medication,anterior segment parameters and surgery-related complications.RESULTS:A total of 7 eyes of 7 CACG patients(age 38.9±11.0y)underwent LCP with a mean follow-up of 27.1±13.7mo(range 16-48mo).Following LCP,mean IOP and glaucoma medications decreased from 26.1±6.1 mm Hg with 3.1±1.1 glaucoma medications pre-treatment to 14.9±3.1 mm Hg(P=0.027)with 0.4±1.1 glaucoma medications(P=0.001)at final follow-up.The anterior chamber depth(ACD),angle opening distance500 and trabecular-iris angle increased from 1.65±0.33 mm,0.05 mm(range 0-0.30 mm)and 5.1°(range,0-31.97°)at baseline to 1.98±0.43 mm(P=0.073),0.53 mm(range 0.42-0.91 mm,P=0.015),45.9°(range,40.2°-59.4°),(P=0.015)in the long-term follow-up,respectively.The deepening of ACD and reopening of anterior chamber angle(ACA)was observed in 6 eyes(85.7%).CONCLUSION:LCP is a promising treatment option for patients with CACG via reducing IOP and glaucoma medication without serious complications.In addition,LCP can bring a significant deepening in ACD and reopening of ACA.展开更多
Computed Tomography(CT)images have been extensively employed in disease diagnosis and treatment,causing a huge concern over the dose of radiation to which patients are exposed.Increasing the radiation dose to get a be...Computed Tomography(CT)images have been extensively employed in disease diagnosis and treatment,causing a huge concern over the dose of radiation to which patients are exposed.Increasing the radiation dose to get a better image may lead to the development of genetic disorders and cancer in the patients;on the other hand,decreasing it by using a Low-Dose CT(LDCT)image may cause more noise and increased artifacts,which can compromise the diagnosis.So,image reconstruction from LDCT image data is necessary to improve radiologists’judgment and confidence.This study proposed three novel models for denoising LDCT images based on Wasserstein Generative Adversarial Network(WGAN).They were incorporated with different loss functions,including Visual Geometry Group(VGG),Structural Similarity Loss(SSIM),and Structurally Sensitive Loss(SSL),to reduce noise and preserve important information on LDCT images and investigate the effect of different types of loss functions.Furthermore,experiments have been conducted on the Graphical Processing Unit(GPU)and Central Processing Unit(CPU)to compare the performance of the proposed models.The results demonstrated that images from the proposed WGAN-SSIM,WGAN-VGG-SSIM,and WGAN-VGG-SSL were denoised better than those from state-of-the-art models(WGAN,WGAN-VGG,and SMGAN)and converged to a stable equilibrium compared with WGAN and WGAN-VGG.The proposed models are effective in reducing noise,suppressing artifacts,and maintaining informative structure and texture details,especially WGAN-VGG-SSL which achieved a high peak-signalto-noise ratio(PNSR)on both GPU(26.1336)and CPU(25.8270).The average accuracy of WGAN-VGG-SSL outperformed that of the state-ofthe-art methods by 1 percent.Experiments prove that theWGAN-VGG-SSL is more stable than the other models on both GPU and CPU.展开更多
Chronic pain is a multifaceted debilitating experience often associated with significant physical and emotional burden. Low dose naltrexone (LDN) has gained attention in recent years for its potential utility in the m...Chronic pain is a multifaceted debilitating experience often associated with significant physical and emotional burden. Low dose naltrexone (LDN) has gained attention in recent years for its potential utility in the management of fibromyalgia, irritable bowel syndrome, multiple sclerosis, and painful diabetic neuropathy. LDN’s analgesic effects have been associated with its ability to increase the production of endorphins while reducing the production of tumor necrosis factor-alpha, interleukin-6, reactive oxygen species and nitric oxide. This meta-analysis aims to systematically review and synthesize the available evidence on efficacy of LDN as an analgesic in pain syndromes, with a focus on chronic (neuro) inflammatory diseases. The goal is to provide clinicians with a more comprehensive estimate of the effectiveness of LDN as a non-opioid option for managing chronic pain and guide future research in the area. Thirteen randomized control trials, published from 1990 to 2022, were selected for the analysis that satisfied inclusion criteria. The overall effects in these studies were calculated using the standardized mean difference (SMD) between the LDN and placebo groups. We found an overall SMD of -10.77 (95% CI: -13.96 to -7.58) with a p-value of 0.002. This indicated that the LDN group experienced a statistically significant reduction in pain compared to placebo. This meta-analysis provides evidence for the potential efficacy of low dose naltrexone in reducing pain and enhancing analgesia in various pain syndromes. LDN may be a useful treatment option for patients suffering from chronic pain, particularly with fibromyalgia, multiple sclerosis, or diabetic neuropathy. However, further research is needed to confirm the efficacy and safety of low dose naltrexone for chronic pain conditions, especially with larger sample sizes, standardized dosing regimens and treatment durations.展开更多
To study the effects of low dose radiation (LDR) on tumor apoptosis, cellcycle progression and changes of apoptosis-related protein Bcl-2 in tumor-bearing mice. Methods:Male mice of Kunming strain were implanted subcu...To study the effects of low dose radiation (LDR) on tumor apoptosis, cellcycle progression and changes of apoptosis-related protein Bcl-2 in tumor-bearing mice. Methods:Male mice of Kunming strain were implanted subcutaneously with S180 sarcoma cells in the left inguenas an in situ experimental animal model. Seven days later, the mice were subjected to 75 mGywhole-body γ-irradiation. At 24 and 48 h after the irradiation, all mice were sacrificed. The tumorsizes were measured, and tumor cell apoptosis and cell cycle progression were analyzed by flowcytometry. The expression of apoptosis-related protein Bcl-2 and the apoptotic rate of tumor cellswere observed by immunohistochemistry and electron microscopy. Results: Tumors grew significantlyslower after LDR (P 【 0.05). The tumor cells were arrested in G1 phrase and the expression of Bcl-2protein decreased at 24 h. Apoptotic rate of tumor cells was increased significantly at 48 h afterLDR (P 【 0.01). Conclusion: LDR could cause a G1-phase arrest and increase the apoptosis of tumorcells through the low level of apoptosis-related protein bcl-2 in the tumor-bearing mice. Theorganized immune function and anti-tumor ability are markedly increased after LDR. Our studyprovides practical evidence of clinical application to cancer treatment.展开更多
Transmission electron microscopy(TEM)offers unparalleled atomic-resolution imaging of complex materials and heterogeneous structures.However,high-energy imaging electrons can induce structural damage,posing a challeng...Transmission electron microscopy(TEM)offers unparalleled atomic-resolution imaging of complex materials and heterogeneous structures.However,high-energy imaging electrons can induce structural damage,posing a challenge for electron-beam-sensitive materials.Cryogenic TEM(Cryo-TEM)has revolutionized structural biology,enabling the visualization of biomolecules in their near-native states at unprecedented detail.The low electron dose imaging and stable cryogenic environment in Cryo-TEM are now being harnessed for the investigation of electron-beam-sensitive materials and low-temperature quantum phenomena.Here,we present a systematic review of the interaction mechanisms between imaging electrons and atomic structures,illustrating the electron beam-induced damage and the mitigating role of Cryo-TEM.This review then explores the advancements in low-dose Cryo-TEM imaging for elucidating the structures of organic-based materials.Furthermore,we showcase the application of Cryo-TEM in the study of strongly correlated quantum materials,including the detection of charge order and novel topological spin textures.Finally,we discuss the future prospects of Cryo-TEM,emphasizing its transformative potential in unraveling the complexities of materials and phenomena across diverse scientific disciplines.展开更多
Previous reports clearly demonstrated that Helicobacter pylori(H.pylori)infection,nonsteroidal anti-inflammatory drugs(NSAID)or low dose aspirin(ASA)use significantly and independently increased the risk for the devel...Previous reports clearly demonstrated that Helicobacter pylori(H.pylori)infection,nonsteroidal anti-inflammatory drugs(NSAID)or low dose aspirin(ASA)use significantly and independently increased the risk for the development of peptic ulcer disease.Today,the presence of H.pylori infection associated with low dose ASA and/or NSAID use in the same patient is becoming more frequent and therefore the potential interaction between these factors and the consequences of it has important implications.Whether NSAID intake in the presence of H.pylori infection may further increase the risk of peptic ulcer carried by the presence of only one risk factor is still a matter of debate.Studies on the interaction between the two risk factors yielded conflicting data and no consensus has been reached in the last years.In addition,the interaction between H.pylori infection and low-dose ASA remains even more controversial.In real clinical practice,we can find different clinical scenarios involving these three factors associated with the presence of different gastrointestinal and cardiovascular risk factors.These huge variety of possible combinations greatly hinder the decision making process of physicians.展开更多
Summary: The study examined the role of endoplasmic reticulum stress (ERS) and signaling pathways of inositol-requiring enzyme-1 (IRE1), RNA-activated protein kinase-like ER kinase (PERK) and activating transcr...Summary: The study examined the role of endoplasmic reticulum stress (ERS) and signaling pathways of inositol-requiring enzyme-1 (IRE1), RNA-activated protein kinase-like ER kinase (PERK) and activating transcription factor-6 (ATF6) in apoptosis of mouse testicular cells treated with low-dose radiation (LDR). In the dose-dependent experiment, the mice were treated with whole-body X-ray irradiation at different doses (25, 50, 75, 100 or 200 mGy) and sacrificed 12 h later. In the time-dependent experiment, the mice were exposed to 75 mGy X-ray irradiation and killed at different time points (3, 6, 12, 18 or 24 h). Testicular cells were harvested for experiments. H202 and NO concentrations, and Ca2+-ATPase activity were detected by biochemical assays, the calcium ion concentration ([Ca2+]i) by flow cytometry using fluo-3 probe, and GRP78 mRNA and protein expressions by quantitative real-time RT-PCR (qRT-PCR) and Western blotting, respectively. The mRNA expressions of S-XBP1, JNK, caspase-12 and CHOP were measured by qRT-PCR, and the protein expressions of IREla, S-XBP1, p-PERK, p-elF2a, ATF6 p50, p-JNK, pro-caspase-12, cleaved caspase-12 and CHOP by Western blot- ting. The results showed that the concentrations of H202 and NO, the mR_NA expressions of GRP78, S-XBP1, JNK, caspase-12 and CHOP, and the protein expressions of GRP78, S-XBP1, IREla, p-PERK, p-elF2a, ATF6 p50, p-JNK, pro-caspase-12, cleaved caspase-12 and CHOP were significantly increased in a time- and dose-dependent manner after LDR. But the [Ca2]i and Ca2-ATPase activities were sig nificantly decreased in a time and dose-dependent manner. It was concluded that the ERS, regulated by IRE 1, PERK and ATF6 pathways, is involved in the apoptosis of testicular cells in LDR mice, which is associated with ERS-apoptotic signaling molecules of JNK, caspase-12 and CHOP.展开更多
WT5”BZ] To study the molecular mechanism of the stimulatory effect of low dose radiation(LDR) on T cell activation. [WT5”BX]Methods.[WT5”BZ] Thymocytes from Kunming mice exposed to whole body irradiation(WBI) with ...WT5”BZ] To study the molecular mechanism of the stimulatory effect of low dose radiation(LDR) on T cell activation. [WT5”BX]Methods.[WT5”BZ] Thymocytes from Kunming mice exposed to whole body irradiation(WBI) with different doses of X rays were analyzed for the changes in signal molecules of the phospholipase C phosphatidylinositol biphosphate(PLC IP2) and G protein adenylate cyclase(AC) pathways. [WT5”BX]Results.[WT5”BZ]It was found that[Ca 2+ ] i increased in response to doses within 0 2 Gy which was most marked after 0 075 Gy and the increase was accentuated in the presence of Con A. The changes in CD3 and calcineurin(CN) expression of the thymocytes followed the same pattern as the alterations in [Ca 2+ ] i after LDR. The expression of α,β1 and β2 isoforms of protein kinase C(PKC) was all up regulated after 0 075 Gy with the increase in PKC β1 expression being most marked. The cAMP/cGMP ratio and PKA activity of the thymocytes was lowered after low dose radiation and increased after doses above 0 5 Gy in a dose dependent manner, thus giving rise to J shaped dose response curves. The Ca antagonist TMB 8 and cAMP stimulant cholera toxin suppressed the augmented thymocyte proliferation induced by LDR. [WT5”BX]Conclusion.[WT5”BZ]Data presented in the present paper suggest that activation of the PLC PIP2 signal pathway and suppression of the AC cAMP signal pathway are involved in the stimulation of the thymocytes following WBI with low dose X rays.展开更多
Objective This paper is to explore the DNA repair mechanism of immune adaptive response (AR) induced by low dose radiation (LDR), the changes of mRNA levels and protein expressions of p53, ATM, DNA-PK catalytic su...Objective This paper is to explore the DNA repair mechanism of immune adaptive response (AR) induced by low dose radiation (LDR), the changes of mRNA levels and protein expressions of p53, ATM, DNA-PK catalytic subunit (DNA-PKcs) and PARP-1 genes in the LDR-induced AR in EL-4 cells. Methods The apoptosis and cell cycle progression of EL-4 cells were detected by flow cytometry in 12 h after the cells received the pre-exposure of 0.075 Gy X-rays (inductive dose, D 1) and the succeeding high dose irradiation (challenge dose, D2; 1.0, 1.5, and 2.0 Gy X-rays, respectively) with or without wortmannin (inhibitor of ATM and DNA-PK) and 3-aminobenzamid (inhibitor of PARP-1). And the protein expressions and mRNA levels related to these genes were detected with flow cytometry and reverse transcription-polymerase chain reaction in 12 h after irradiation with D2. Results The mRNA and protein expressions of p53 and PARP-1 in EL-4 cells in the D1 + D2 groups were much lower than those in the D2 groups, and those of PARP-1 in the 3-AB + D2 and the 3-AB + D1 + D2 groups were much lower than those in the D2 and the D1 + D2 groups. The percentage of apoptotic EL-4 cells in the 3-AB + D1 + D2 groups was much higher than that in the D1 + D2 groups, that in the G0/G1 and the G2 + M phases was much higher, and that in the S phase were much lower. Although the ATM and DNA-PKcs mRNA and protein expressions in wortmannin + D1 + D2 groups were much lower than those in the D1 + D2 groups, there were no significant changes in the apoptosis and cell cycle progression between the wortmannin + D1 + D2 and the D1 + D2 groups. Conclusion PARP-1 and p53 might play important roles in AR induced by LDR.展开更多
AIM: To study the mechanism involved in the potentially beneficial effect of ultra low dose aspirin (ULDA) in prehepatic portal hypertension, rats were pretreated with selective COX 1 or 2 inhibitors (SC-560 or NS-398...AIM: To study the mechanism involved in the potentially beneficial effect of ultra low dose aspirin (ULDA) in prehepatic portal hypertension, rats were pretreated with selective COX 1 or 2 inhibitors (SC-560 or NS-398 respectively), and subsequently injected with ULDA or placebo. METHODS: Portal hypertension was induced by portal vein ligation. Platelet activity was investigated with an in-vivo model of laser induced thrombus production in mesenteric circulation and induced hemorrhagic time (IHT). Platelet aggregation induced by ADP and dosing of prostanoid products 6-keto-PGF1α, TXB2, PGE2 and LTB4 were also performed. RESULTS: The portal hypertensive group receiving a placebo showed a decreased in vivo platelet activity with prolonged IHT, an effect that was normalized by ULDA. SC-560 induced a mild antithrombotic effect in the normal rats, and an unmodified effect of ULDA. NS-398 had a mild prothrombotic action in portal hypertensive rats, similar to ULDA, but inhibited a further effect when ULDA was added. An increased 6-keto-PGF1α was observed in portal hypertensive group that was normalised after ULDA administration. TXA2 level after ULDA, remained unchanged. CONCLUSION: These results suggest that the effect of ULDA on platelet activity in portal hypertensive rats, could act through a COX 2 pathway more than the COX 1, predominant for aspirin at higher doses.展开更多
We sought to evaluate the efficacy and effects of low-dose tacrolimus (FK506) to recipients with living donor liver transplantation (LDLT). A total of 66 patients who underwent LDLT between 2001 and 2007 were enro...We sought to evaluate the efficacy and effects of low-dose tacrolimus (FK506) to recipients with living donor liver transplantation (LDLT). A total of 66 patients who underwent LDLT between 2001 and 2007 were enrolled in this study. According to different doses of tacrolimus, the recipients were randomly divided into two groups: the low-dose tacrolimus group (group A) and the normal-dose tacrolimus group (group B). The blood concentration of tacrolimus and its side effects including infection, hyperglycemia, hypertension, high blood creatinine and jaundice were monitored once a week at the perioperative period, and once a month thereafter. Besides, the survival rates of the recipients were analyzed at the 1and 3-year time point after operation. Among these patients, no significant acute rejection was detected after LDLT. The incidences of infection, hyperglycemia, liver dysfunction and renal impairment in group A were markedly lower than those in group B. However, no significant differences were detected in the incidence of hypertension between the two groups. Moreover, the recipients in each group had a similar survival rate according to the results of 1and 3-year follow-up. The incidence of side effects that associated with tacrolimus positively correlated with tacrolimus blood concentration. In conclusion, long-term and low-dose administration of tacrolimus is a safe and effective treatment for LDLT recipients.展开更多
Objective:To investigate the value of application of low-dose and optimized length CT scan on puncture results,complications and patients’radiation dosage during CT-guided percutaneous biopsy of pulmonary nodules(PTN...Objective:To investigate the value of application of low-dose and optimized length CT scan on puncture results,complications and patients’radiation dosage during CT-guided percutaneous biopsy of pulmonary nodules(PTNB).Methods:A total of 231 patients with PTNB under CT guidance were collected.Low dose scanning utilized tube current of 20 mA as compared with 40 mA in conventional dosage.Optimized length in CT is defined as intentionally narrowing the range of CT scanning just to cover 25 mm(5 layers)around the target layer during needle adjustment.According to whether low-dose scans and optimized length scans techniques were utilized,patients were divided into three groups:conventional group(conventional sequence+no optimization),optimized length group(conventional sequence+optimized length),and low-dose optimized length group(low dose sequence+optimized length).The ED(effective dose),the DLP(dose length product),the average CTDIvol(Volume CT dose index),total milliampere second between subgroups were compared.Results:Compared with the conventional group,ED,intraoperative guidance DLP,total milliseconds and operation time in the optimized length group were reduced by 18.2%(P=0.01),37%(P=0.003),17.5%(P=0.013)and13.3%(P=0.021)respectively.Compared with the optimized length group,the ED was reduced by 87%,preoperative positioning,intraoperative guidance and postoperative review DLP were also reduced by 88%,total milliampere second was reduced by 79%,with an average CTDIvol was reduced by 86%,in the low-dose optimized length group(P<0.001 for all).Conclusion:Optimizing the length during CT scanning can effectively reduce the intraoperative radiation dose and reduce the operation time compared with conventional plan;low-dose and optimized length CT scan can further reduce the total radiation dose compared with optimized length group with no differences on intraoperative complications,biopsy results and operation time.展开更多
It is first reported in the present paper that whole-body irradiation (WBI) with low dose X-rays could increase intracellular calcium ions ([Ca2+]i) and stimulate protein kinase C (PKC) activity of mouse lymphocytes. ...It is first reported in the present paper that whole-body irradiation (WBI) with low dose X-rays could increase intracellular calcium ions ([Ca2+]i) and stimulate protein kinase C (PKC) activity of mouse lymphocytes. Following WBI of male Kunming micc With 75 mGy X-rays at a dose rate of 12.5 mGy/min the mobilization of [Ca2+]i with Con A in CD4+ and CD8+ Cells in the thymus and spleen was potentiated and the amplitude of [Ca2+], mobilization in thymocytes in response to anti-CD3 monoclonal antibody increased with time from 4 to 24 h following low dose radiation. The PKC activity in the homogenate of spleen was markedly stimulated 12 h after WBl with 75 mGy, reaching its peak value at 24-48 h and coming down to lower than normal on day 7. However, the PKC activity in the separated T lymphocytes reached its peak value at 12 h and that in the B lymphocytes reached its peak value on day 4, both coming down to below control on day 7. The implications of this facilitation of signal transduction in T lymphocytes in the mechanism of immunoenhancement after low dose radiation were discussed展开更多
Human lymphocytes pre-exposed to 10 mGy or 50 mGy of X-rays become less sensitive to subsequent large dose irradiation, exhibited lower rate of chromosome aberration than expected. This adaptive response could be inhi...Human lymphocytes pre-exposed to 10 mGy or 50 mGy of X-rays become less sensitive to subsequent large dose irradiation, exhibited lower rate of chromosome aberration than expected. This adaptive response could be inhibited by cycloheximide, a protein synthesis inhibitor for successive 2 h period ranging from 0.5h before to 4h after the low dose exposure, indicating that the adaptive response was directly related with the protein synthesis.展开更多
The low dose hyper-radiosensitivity (HRS) in human lung cancer cell line A549 was investigated, the changes of ATM kinase, cell cycle and apoptosis of cells at different doses of radiation were observed, and the pos...The low dose hyper-radiosensitivity (HRS) in human lung cancer cell line A549 was investigated, the changes of ATM kinase, cell cycle and apoptosis of cells at different doses of radiation were observed, and the possible mechanisms were discussed. A549 cells in logarithmic growth phase were irradiated with ^60Co y-rays at doses of 0-2 Gy. Together with flow cytometry for precise cell sorting, cell survival fraction was measured by means of conventional colony-formation assay. The expression of ATM1981 Ser-P protein was examined by Western blot 1 h after radiation. Apoptosis was detected by Hoechst 33258 fluorescent staining, and Annexin V-FITC/PI staining flow cytometry 24 h after radiation. Cell cycle distribution was observed by flow cytometry 6, 12 and 24 h after radiation. The results showed that the expression of ATM1981Ser-P protein was observed at 0.2 Gy, followed by an increase at 〉0.2 Gy, and reached the peak at 0.5 Gy, with little further increase as the dose exceeded 0.5 Gy. Twenty-four h after radiation, partial cells presented the characteristic morphological changes of apoptosis, and the cell apoptosis curve was coincident with the survival curve. As compared with control group, the cell cycle almost had no changes after exposure to 0.1 and 0.2 Gy radiation (P〉0.05). After exposure to 0.3, 0.4 and 0.5 Gy radiation, G2/M phase arrest occurred 6 and 12 h after radiation (P〈0.05), and the ratio of G2/M phase cells was decreased 24 h after radiation (P〈0.05). It was concluded that A549 cells displayed the phenomenon of HRS/IRR. The mode of cell death was mainly apoptosis. The activity of ATM and cell cycle change may take an important role in HRS/IRR.展开更多
A dissolution test for fesoterodine low dose extended-release tablets using liquid chromatographic(LC) method equipped with a C18 monolithic column was developed and validated. LC system was operated isocratically a...A dissolution test for fesoterodine low dose extended-release tablets using liquid chromatographic(LC) method equipped with a C18 monolithic column was developed and validated. LC system was operated isocratically at controlled temperature(40 1C) using a mobile phase of acetonitrile:methanol:0.03 M ammonium acetate(p H 3.8)(30:15:55, v/v/v), run at a flow rate of 1.5 m L/min and detected at 208 nm. The best dissolution conditions for this formulation were achieved using a USP apparatus 2(paddle) at 100 rpm and 900 m L of phosphate buffer at p H 6.8 as the dissolution medium.Validation parameters such as the specificity, linearity, accuracy, precision, and robustness were evaluated according to international guidelines, giving results within the acceptable range. The kinetic parameters of drug release were also investigated using model-dependent methods and the dissolution profiles were best described by the Higuchi model. The validated dissolution test can be applied for quality control of this formulation.展开更多
To investigate the effects of long-term low dose hormone replacement therapy (HRT) on postmenopaosal women in homone level, cognition score, hippocampus volume, and magnetic resonance spectroscopy (MRS) parameters...To investigate the effects of long-term low dose hormone replacement therapy (HRT) on postmenopaosal women in homone level, cognition score, hippocampus volume, and magnetic resonance spectroscopy (MRS) parameters. Methods A total of 182 postmenopausal women aged 50-87 years were chosen at Peking Union Medical College Hospital and assigned to HRT group and control group. The volunteers of HRT group had taken low dose hormone [ estradiol (E2 ) 0. 5-1.0 mg and progesterone 0.5-2.0 mg, once a day ] for 4-33 years. The concentrations of E2, progesterone, and testosterone were measured using enzyme-linked immunosorbent assay (ELISA). The gene types of apolipoprotein E (ApoE) were measured by polymerase chain reaction, and the subjects with susceptible genes ( ApoE ε3/ε4) of Alzheimer's disease (AD) were screened. Their hippocampus volumes and MRS parameters were obtained through magnetic resonance imaging (MRI), and results in two groups were analyzed by statistical method. Results Compared with control group, the concentrations of E2 at each age stage in HRT group were significantly higher (P 〈0. 05) except the 80-89 years old subgroup; yet, there were no statistical differences in the concentrations of progesterone and testosterone between the two groups. There was no obvious difference in ApoE subtypes distribution between the two groups The results of hippocampus MRI for the subjects with susceptible genes ApoE ε3/ε4 (HRT group 14 cases, control group 11 cases) showed that the ratio of bilateral hippocampus volume to whole brain volume in HRT group (0. 406 ± 0.028) was signiticantlyhigher than control gronp (0.369±0.031, P〈0.05). Theresults of ^1H MRS for the subjects with susceptible genes ApoE ε3/ε4 ( HRT group 12 cases, control group 11 cases) showed that the N-acetylaspartate/total creatine at the area of hippocampus in HRT group ( 1.54±0. 08 ) were significantly higher than control group ( 1.45±0. 13, P 〈 0. 05). Conclusions For postmenopausal women, long-term low dose HRT can maintain the physiological concentration of E2 in plasma. Furthermore, the hippocampus MRI performed on those with ApoE ε3/ε3 genes shows that long-term low dose HRT can prevent hippocampus atrophy, which is beneficial to maintain the brain function and prevent AD.展开更多
文摘The injection to emerging adult workerbees with fluvalinate doses ranging from 1 femtomol to 1 nanomol per individual resulted in a reduction of haemolymph carbohydrate concentrations, particularly at the lowest dose 1 hour after injections. At the same time, a large increase was observed for triacylglycerols and to a much lesser extent for steroids and phospholipids with 0.1 picomol per bee. By contrast, fatty acids, steroids and triacylglycerols exhibited a depress at the higher dose. Most responses were thus biphasic, showing that much attention should be paid to the effects of very low doses of pesticide.
基金funded by the National Natural Science Foundation of China (Nos.81771972,52171243,and 52371256)the National Key Research and Development Program of China (No.2017YFC0107405).
文摘X-ray excited photodynamic therapy(X-PDT)is the bravo answer of photodynamic therapy(PDT)for deep-seated tumors,as it employs X-ray as the irradiation source to overcome the limitation of light penetration depth.However,high X-ray irradiation dose caused organ lesions and side effects became the major barrier to X-PDT application.To address this issue,this work employed a classic-al co-precipitation reaction to synthesize NaLuF_(4):15%Tb^(3+)(NLF)with an average particle size of(23.48±0.91)nm,which was then coupled with the photosensitizer merocyanine 540(MC540)to form the X-PDT system NLF-MC540 with high production of singlet oxygen.The system could induce antitumor efficacy to about 24%in relative low dose X-ray irradiation range(0.1-0.3 Gy).In vivo,when NLF-MC540 irradiated by 0.1 Gy X-ray,the tumor inhibition percentage reached 89.5%±5.7%.The therapeutic mechanism of low dose X-PDT was found.A significant increase of neutrophils in serum was found on the third day after X-PDT.By immunohistochemical staining of tumor sections,the Ly6G^(+),CD8^(+),and CD11c^(+)cells infiltrated in the tumor microenvironment were studied.Utilizing the bilat-eral tumor model,the NLF-MC540 with 0.1 Gy X-ray irradiation could inhibit both the primary tumor and the distant tumor growth.De-tected by enzyme linked immunosorbent assay(ELISA),two cytokines IFN-γand TNF-αin serum were upregulated 7 and 6 times than negative control,respectively.Detected by enzyme linked immune spot assay(ELISPOT),the number of immune cells attributable to the IFN-γand TNF-αlevels in the group of low dose X-PDT were 14 and 6 times greater than that in the negative control group,respectively.Thus,it conclude that low dose X-PDT system could successfully upregulate the levels of immune cells,stimulate the secretion of cy-tokines(especially IFN-γand TNF-α),activate antitumor immunity,and finally inhibit colon tumor growth.
文摘The present paradigm of radiation-induced carcinogenesis has been based on somatic mutation theory initiating a mutation in somatic cells derived from DNA damage by ionizing radiation. A non-threshold linear model has been assumed from high doses to low doses. As an alternative to this, we are proposing a new model that epigenetic changes induced by low dose irradiation may be a first step of carcinogenesis. Our preliminary data suggesting the epigenetic nature and reports on various stress response to ionizing radiation are presented.
基金Supported by the Program for Zhejiang Leading Talent of S&T Innovation(No.2021R52012)Key Research and Development Projects of Zhejiang Province(No.2022C03112)the Basic Scientific Research Program of Wenzhou(No.Y2020365).
文摘AIM:To describe the outcome of using low-dose laser cycloplasty(LCP)in chronic angle-closure glaucoma(CACG).METHODS:A retrospective case series.Medical charts of CACG patients who underwent LCP in the Eye Hospital of Wenzhou Medical University were reviewed.The main outcomes included intraocular pressure(IOP),the number of glaucoma medication,anterior segment parameters and surgery-related complications.RESULTS:A total of 7 eyes of 7 CACG patients(age 38.9±11.0y)underwent LCP with a mean follow-up of 27.1±13.7mo(range 16-48mo).Following LCP,mean IOP and glaucoma medications decreased from 26.1±6.1 mm Hg with 3.1±1.1 glaucoma medications pre-treatment to 14.9±3.1 mm Hg(P=0.027)with 0.4±1.1 glaucoma medications(P=0.001)at final follow-up.The anterior chamber depth(ACD),angle opening distance500 and trabecular-iris angle increased from 1.65±0.33 mm,0.05 mm(range 0-0.30 mm)and 5.1°(range,0-31.97°)at baseline to 1.98±0.43 mm(P=0.073),0.53 mm(range 0.42-0.91 mm,P=0.015),45.9°(range,40.2°-59.4°),(P=0.015)in the long-term follow-up,respectively.The deepening of ACD and reopening of anterior chamber angle(ACA)was observed in 6 eyes(85.7%).CONCLUSION:LCP is a promising treatment option for patients with CACG via reducing IOP and glaucoma medication without serious complications.In addition,LCP can bring a significant deepening in ACD and reopening of ACA.
文摘Computed Tomography(CT)images have been extensively employed in disease diagnosis and treatment,causing a huge concern over the dose of radiation to which patients are exposed.Increasing the radiation dose to get a better image may lead to the development of genetic disorders and cancer in the patients;on the other hand,decreasing it by using a Low-Dose CT(LDCT)image may cause more noise and increased artifacts,which can compromise the diagnosis.So,image reconstruction from LDCT image data is necessary to improve radiologists’judgment and confidence.This study proposed three novel models for denoising LDCT images based on Wasserstein Generative Adversarial Network(WGAN).They were incorporated with different loss functions,including Visual Geometry Group(VGG),Structural Similarity Loss(SSIM),and Structurally Sensitive Loss(SSL),to reduce noise and preserve important information on LDCT images and investigate the effect of different types of loss functions.Furthermore,experiments have been conducted on the Graphical Processing Unit(GPU)and Central Processing Unit(CPU)to compare the performance of the proposed models.The results demonstrated that images from the proposed WGAN-SSIM,WGAN-VGG-SSIM,and WGAN-VGG-SSL were denoised better than those from state-of-the-art models(WGAN,WGAN-VGG,and SMGAN)and converged to a stable equilibrium compared with WGAN and WGAN-VGG.The proposed models are effective in reducing noise,suppressing artifacts,and maintaining informative structure and texture details,especially WGAN-VGG-SSL which achieved a high peak-signalto-noise ratio(PNSR)on both GPU(26.1336)and CPU(25.8270).The average accuracy of WGAN-VGG-SSL outperformed that of the state-ofthe-art methods by 1 percent.Experiments prove that theWGAN-VGG-SSL is more stable than the other models on both GPU and CPU.
文摘Chronic pain is a multifaceted debilitating experience often associated with significant physical and emotional burden. Low dose naltrexone (LDN) has gained attention in recent years for its potential utility in the management of fibromyalgia, irritable bowel syndrome, multiple sclerosis, and painful diabetic neuropathy. LDN’s analgesic effects have been associated with its ability to increase the production of endorphins while reducing the production of tumor necrosis factor-alpha, interleukin-6, reactive oxygen species and nitric oxide. This meta-analysis aims to systematically review and synthesize the available evidence on efficacy of LDN as an analgesic in pain syndromes, with a focus on chronic (neuro) inflammatory diseases. The goal is to provide clinicians with a more comprehensive estimate of the effectiveness of LDN as a non-opioid option for managing chronic pain and guide future research in the area. Thirteen randomized control trials, published from 1990 to 2022, were selected for the analysis that satisfied inclusion criteria. The overall effects in these studies were calculated using the standardized mean difference (SMD) between the LDN and placebo groups. We found an overall SMD of -10.77 (95% CI: -13.96 to -7.58) with a p-value of 0.002. This indicated that the LDN group experienced a statistically significant reduction in pain compared to placebo. This meta-analysis provides evidence for the potential efficacy of low dose naltrexone in reducing pain and enhancing analgesia in various pain syndromes. LDN may be a useful treatment option for patients suffering from chronic pain, particularly with fibromyalgia, multiple sclerosis, or diabetic neuropathy. However, further research is needed to confirm the efficacy and safety of low dose naltrexone for chronic pain conditions, especially with larger sample sizes, standardized dosing regimens and treatment durations.
文摘To study the effects of low dose radiation (LDR) on tumor apoptosis, cellcycle progression and changes of apoptosis-related protein Bcl-2 in tumor-bearing mice. Methods:Male mice of Kunming strain were implanted subcutaneously with S180 sarcoma cells in the left inguenas an in situ experimental animal model. Seven days later, the mice were subjected to 75 mGywhole-body γ-irradiation. At 24 and 48 h after the irradiation, all mice were sacrificed. The tumorsizes were measured, and tumor cell apoptosis and cell cycle progression were analyzed by flowcytometry. The expression of apoptosis-related protein Bcl-2 and the apoptotic rate of tumor cellswere observed by immunohistochemistry and electron microscopy. Results: Tumors grew significantlyslower after LDR (P 【 0.05). The tumor cells were arrested in G1 phrase and the expression of Bcl-2protein decreased at 24 h. Apoptotic rate of tumor cells was increased significantly at 48 h afterLDR (P 【 0.01). Conclusion: LDR could cause a G1-phase arrest and increase the apoptosis of tumorcells through the low level of apoptosis-related protein bcl-2 in the tumor-bearing mice. Theorganized immune function and anti-tumor ability are markedly increased after LDR. Our studyprovides practical evidence of clinical application to cancer treatment.
基金Project supported by the National Natural Science Foundation of China (Grant No.11974156)the Guangdong Innovative and Entrepreneurial Research Team Program (Grant No.2019ZT08C044)+1 种基金the Shenzhen Science and Technology Program (Grant Nos.KQTD20190929173815000 and 20200925161102001)the Science,Technology and Innovation Commission of Shenzhen Municipality (Grant No.ZDSYS20190902092905285)。
文摘Transmission electron microscopy(TEM)offers unparalleled atomic-resolution imaging of complex materials and heterogeneous structures.However,high-energy imaging electrons can induce structural damage,posing a challenge for electron-beam-sensitive materials.Cryogenic TEM(Cryo-TEM)has revolutionized structural biology,enabling the visualization of biomolecules in their near-native states at unprecedented detail.The low electron dose imaging and stable cryogenic environment in Cryo-TEM are now being harnessed for the investigation of electron-beam-sensitive materials and low-temperature quantum phenomena.Here,we present a systematic review of the interaction mechanisms between imaging electrons and atomic structures,illustrating the electron beam-induced damage and the mitigating role of Cryo-TEM.This review then explores the advancements in low-dose Cryo-TEM imaging for elucidating the structures of organic-based materials.Furthermore,we showcase the application of Cryo-TEM in the study of strongly correlated quantum materials,including the detection of charge order and novel topological spin textures.Finally,we discuss the future prospects of Cryo-TEM,emphasizing its transformative potential in unraveling the complexities of materials and phenomena across diverse scientific disciplines.
文摘Previous reports clearly demonstrated that Helicobacter pylori(H.pylori)infection,nonsteroidal anti-inflammatory drugs(NSAID)or low dose aspirin(ASA)use significantly and independently increased the risk for the development of peptic ulcer disease.Today,the presence of H.pylori infection associated with low dose ASA and/or NSAID use in the same patient is becoming more frequent and therefore the potential interaction between these factors and the consequences of it has important implications.Whether NSAID intake in the presence of H.pylori infection may further increase the risk of peptic ulcer carried by the presence of only one risk factor is still a matter of debate.Studies on the interaction between the two risk factors yielded conflicting data and no consensus has been reached in the last years.In addition,the interaction between H.pylori infection and low-dose ASA remains even more controversial.In real clinical practice,we can find different clinical scenarios involving these three factors associated with the presence of different gastrointestinal and cardiovascular risk factors.These huge variety of possible combinations greatly hinder the decision making process of physicians.
基金supported by the grants from the National Natural Science Foundation of China(No.30970681)Basic Research and Operating Expenses of Jilin University(No.200903116)
文摘Summary: The study examined the role of endoplasmic reticulum stress (ERS) and signaling pathways of inositol-requiring enzyme-1 (IRE1), RNA-activated protein kinase-like ER kinase (PERK) and activating transcription factor-6 (ATF6) in apoptosis of mouse testicular cells treated with low-dose radiation (LDR). In the dose-dependent experiment, the mice were treated with whole-body X-ray irradiation at different doses (25, 50, 75, 100 or 200 mGy) and sacrificed 12 h later. In the time-dependent experiment, the mice were exposed to 75 mGy X-ray irradiation and killed at different time points (3, 6, 12, 18 or 24 h). Testicular cells were harvested for experiments. H202 and NO concentrations, and Ca2+-ATPase activity were detected by biochemical assays, the calcium ion concentration ([Ca2+]i) by flow cytometry using fluo-3 probe, and GRP78 mRNA and protein expressions by quantitative real-time RT-PCR (qRT-PCR) and Western blotting, respectively. The mRNA expressions of S-XBP1, JNK, caspase-12 and CHOP were measured by qRT-PCR, and the protein expressions of IREla, S-XBP1, p-PERK, p-elF2a, ATF6 p50, p-JNK, pro-caspase-12, cleaved caspase-12 and CHOP by Western blot- ting. The results showed that the concentrations of H202 and NO, the mR_NA expressions of GRP78, S-XBP1, JNK, caspase-12 and CHOP, and the protein expressions of GRP78, S-XBP1, IREla, p-PERK, p-elF2a, ATF6 p50, p-JNK, pro-caspase-12, cleaved caspase-12 and CHOP were significantly increased in a time- and dose-dependent manner after LDR. But the [Ca2]i and Ca2-ATPase activities were sig nificantly decreased in a time and dose-dependent manner. It was concluded that the ERS, regulated by IRE 1, PERK and ATF6 pathways, is involved in the apoptosis of testicular cells in LDR mice, which is associated with ERS-apoptotic signaling molecules of JNK, caspase-12 and CHOP.
基金This work was supported by a grant from NSFC (No.39570188)
文摘WT5”BZ] To study the molecular mechanism of the stimulatory effect of low dose radiation(LDR) on T cell activation. [WT5”BX]Methods.[WT5”BZ] Thymocytes from Kunming mice exposed to whole body irradiation(WBI) with different doses of X rays were analyzed for the changes in signal molecules of the phospholipase C phosphatidylinositol biphosphate(PLC IP2) and G protein adenylate cyclase(AC) pathways. [WT5”BX]Results.[WT5”BZ]It was found that[Ca 2+ ] i increased in response to doses within 0 2 Gy which was most marked after 0 075 Gy and the increase was accentuated in the presence of Con A. The changes in CD3 and calcineurin(CN) expression of the thymocytes followed the same pattern as the alterations in [Ca 2+ ] i after LDR. The expression of α,β1 and β2 isoforms of protein kinase C(PKC) was all up regulated after 0 075 Gy with the increase in PKC β1 expression being most marked. The cAMP/cGMP ratio and PKA activity of the thymocytes was lowered after low dose radiation and increased after doses above 0 5 Gy in a dose dependent manner, thus giving rise to J shaped dose response curves. The Ca antagonist TMB 8 and cAMP stimulant cholera toxin suppressed the augmented thymocyte proliferation induced by LDR. [WT5”BX]Conclusion.[WT5”BZ]Data presented in the present paper suggest that activation of the PLC PIP2 signal pathway and suppression of the AC cAMP signal pathway are involved in the stimulation of the thymocytes following WBI with low dose X rays.
基金supported by the National Natural Science Foundation of China(30570546 and 30870747)the Natural Science Foundation of Jilin Province (20090458 and 201015183)+1 种基金the Young Teachers Innovative Foundation of Jilin University(421010043430)the Young Scholars Research Foundation Program of China-Japan Union Hospital(2009)
文摘Objective This paper is to explore the DNA repair mechanism of immune adaptive response (AR) induced by low dose radiation (LDR), the changes of mRNA levels and protein expressions of p53, ATM, DNA-PK catalytic subunit (DNA-PKcs) and PARP-1 genes in the LDR-induced AR in EL-4 cells. Methods The apoptosis and cell cycle progression of EL-4 cells were detected by flow cytometry in 12 h after the cells received the pre-exposure of 0.075 Gy X-rays (inductive dose, D 1) and the succeeding high dose irradiation (challenge dose, D2; 1.0, 1.5, and 2.0 Gy X-rays, respectively) with or without wortmannin (inhibitor of ATM and DNA-PK) and 3-aminobenzamid (inhibitor of PARP-1). And the protein expressions and mRNA levels related to these genes were detected with flow cytometry and reverse transcription-polymerase chain reaction in 12 h after irradiation with D2. Results The mRNA and protein expressions of p53 and PARP-1 in EL-4 cells in the D1 + D2 groups were much lower than those in the D2 groups, and those of PARP-1 in the 3-AB + D2 and the 3-AB + D1 + D2 groups were much lower than those in the D2 and the D1 + D2 groups. The percentage of apoptotic EL-4 cells in the 3-AB + D1 + D2 groups was much higher than that in the D1 + D2 groups, that in the G0/G1 and the G2 + M phases was much higher, and that in the S phase were much lower. Although the ATM and DNA-PKcs mRNA and protein expressions in wortmannin + D1 + D2 groups were much lower than those in the D1 + D2 groups, there were no significant changes in the apoptosis and cell cycle progression between the wortmannin + D1 + D2 and the D1 + D2 groups. Conclusion PARP-1 and p53 might play important roles in AR induced by LDR.
文摘AIM: To study the mechanism involved in the potentially beneficial effect of ultra low dose aspirin (ULDA) in prehepatic portal hypertension, rats were pretreated with selective COX 1 or 2 inhibitors (SC-560 or NS-398 respectively), and subsequently injected with ULDA or placebo. METHODS: Portal hypertension was induced by portal vein ligation. Platelet activity was investigated with an in-vivo model of laser induced thrombus production in mesenteric circulation and induced hemorrhagic time (IHT). Platelet aggregation induced by ADP and dosing of prostanoid products 6-keto-PGF1α, TXB2, PGE2 and LTB4 were also performed. RESULTS: The portal hypertensive group receiving a placebo showed a decreased in vivo platelet activity with prolonged IHT, an effect that was normalized by ULDA. SC-560 induced a mild antithrombotic effect in the normal rats, and an unmodified effect of ULDA. NS-398 had a mild prothrombotic action in portal hypertensive rats, similar to ULDA, but inhibited a further effect when ULDA was added. An increased 6-keto-PGF1α was observed in portal hypertensive group that was normalised after ULDA administration. TXA2 level after ULDA, remained unchanged. CONCLUSION: These results suggest that the effect of ULDA on platelet activity in portal hypertensive rats, could act through a COX 2 pathway more than the COX 1, predominant for aspirin at higher doses.
文摘We sought to evaluate the efficacy and effects of low-dose tacrolimus (FK506) to recipients with living donor liver transplantation (LDLT). A total of 66 patients who underwent LDLT between 2001 and 2007 were enrolled in this study. According to different doses of tacrolimus, the recipients were randomly divided into two groups: the low-dose tacrolimus group (group A) and the normal-dose tacrolimus group (group B). The blood concentration of tacrolimus and its side effects including infection, hyperglycemia, hypertension, high blood creatinine and jaundice were monitored once a week at the perioperative period, and once a month thereafter. Besides, the survival rates of the recipients were analyzed at the 1and 3-year time point after operation. Among these patients, no significant acute rejection was detected after LDLT. The incidences of infection, hyperglycemia, liver dysfunction and renal impairment in group A were markedly lower than those in group B. However, no significant differences were detected in the incidence of hypertension between the two groups. Moreover, the recipients in each group had a similar survival rate according to the results of 1and 3-year follow-up. The incidence of side effects that associated with tacrolimus positively correlated with tacrolimus blood concentration. In conclusion, long-term and low-dose administration of tacrolimus is a safe and effective treatment for LDLT recipients.
基金supported by grants from National Natural Science Foundation of China(No.81801804).
文摘Objective:To investigate the value of application of low-dose and optimized length CT scan on puncture results,complications and patients’radiation dosage during CT-guided percutaneous biopsy of pulmonary nodules(PTNB).Methods:A total of 231 patients with PTNB under CT guidance were collected.Low dose scanning utilized tube current of 20 mA as compared with 40 mA in conventional dosage.Optimized length in CT is defined as intentionally narrowing the range of CT scanning just to cover 25 mm(5 layers)around the target layer during needle adjustment.According to whether low-dose scans and optimized length scans techniques were utilized,patients were divided into three groups:conventional group(conventional sequence+no optimization),optimized length group(conventional sequence+optimized length),and low-dose optimized length group(low dose sequence+optimized length).The ED(effective dose),the DLP(dose length product),the average CTDIvol(Volume CT dose index),total milliampere second between subgroups were compared.Results:Compared with the conventional group,ED,intraoperative guidance DLP,total milliseconds and operation time in the optimized length group were reduced by 18.2%(P=0.01),37%(P=0.003),17.5%(P=0.013)and13.3%(P=0.021)respectively.Compared with the optimized length group,the ED was reduced by 87%,preoperative positioning,intraoperative guidance and postoperative review DLP were also reduced by 88%,total milliampere second was reduced by 79%,with an average CTDIvol was reduced by 86%,in the low-dose optimized length group(P<0.001 for all).Conclusion:Optimizing the length during CT scanning can effectively reduce the intraoperative radiation dose and reduce the operation time compared with conventional plan;low-dose and optimized length CT scan can further reduce the total radiation dose compared with optimized length group with no differences on intraoperative complications,biopsy results and operation time.
文摘It is first reported in the present paper that whole-body irradiation (WBI) with low dose X-rays could increase intracellular calcium ions ([Ca2+]i) and stimulate protein kinase C (PKC) activity of mouse lymphocytes. Following WBI of male Kunming micc With 75 mGy X-rays at a dose rate of 12.5 mGy/min the mobilization of [Ca2+]i with Con A in CD4+ and CD8+ Cells in the thymus and spleen was potentiated and the amplitude of [Ca2+], mobilization in thymocytes in response to anti-CD3 monoclonal antibody increased with time from 4 to 24 h following low dose radiation. The PKC activity in the homogenate of spleen was markedly stimulated 12 h after WBl with 75 mGy, reaching its peak value at 24-48 h and coming down to lower than normal on day 7. However, the PKC activity in the separated T lymphocytes reached its peak value at 12 h and that in the B lymphocytes reached its peak value on day 4, both coming down to below control on day 7. The implications of this facilitation of signal transduction in T lymphocytes in the mechanism of immunoenhancement after low dose radiation were discussed
文摘Human lymphocytes pre-exposed to 10 mGy or 50 mGy of X-rays become less sensitive to subsequent large dose irradiation, exhibited lower rate of chromosome aberration than expected. This adaptive response could be inhibited by cycloheximide, a protein synthesis inhibitor for successive 2 h period ranging from 0.5h before to 4h after the low dose exposure, indicating that the adaptive response was directly related with the protein synthesis.
文摘The low dose hyper-radiosensitivity (HRS) in human lung cancer cell line A549 was investigated, the changes of ATM kinase, cell cycle and apoptosis of cells at different doses of radiation were observed, and the possible mechanisms were discussed. A549 cells in logarithmic growth phase were irradiated with ^60Co y-rays at doses of 0-2 Gy. Together with flow cytometry for precise cell sorting, cell survival fraction was measured by means of conventional colony-formation assay. The expression of ATM1981 Ser-P protein was examined by Western blot 1 h after radiation. Apoptosis was detected by Hoechst 33258 fluorescent staining, and Annexin V-FITC/PI staining flow cytometry 24 h after radiation. Cell cycle distribution was observed by flow cytometry 6, 12 and 24 h after radiation. The results showed that the expression of ATM1981Ser-P protein was observed at 0.2 Gy, followed by an increase at 〉0.2 Gy, and reached the peak at 0.5 Gy, with little further increase as the dose exceeded 0.5 Gy. Twenty-four h after radiation, partial cells presented the characteristic morphological changes of apoptosis, and the cell apoptosis curve was coincident with the survival curve. As compared with control group, the cell cycle almost had no changes after exposure to 0.1 and 0.2 Gy radiation (P〉0.05). After exposure to 0.3, 0.4 and 0.5 Gy radiation, G2/M phase arrest occurred 6 and 12 h after radiation (P〈0.05), and the ratio of G2/M phase cells was decreased 24 h after radiation (P〈0.05). It was concluded that A549 cells displayed the phenomenon of HRS/IRR. The mode of cell death was mainly apoptosis. The activity of ATM and cell cycle change may take an important role in HRS/IRR.
基金CAPES(Coordenacao de Aperfeicoamento de Pessoal de Nível Superior)FAPERJ(Fundacao de Amparo a Pesquisa do Estado do Rio de Janeiro)for the financial support
文摘A dissolution test for fesoterodine low dose extended-release tablets using liquid chromatographic(LC) method equipped with a C18 monolithic column was developed and validated. LC system was operated isocratically at controlled temperature(40 1C) using a mobile phase of acetonitrile:methanol:0.03 M ammonium acetate(p H 3.8)(30:15:55, v/v/v), run at a flow rate of 1.5 m L/min and detected at 208 nm. The best dissolution conditions for this formulation were achieved using a USP apparatus 2(paddle) at 100 rpm and 900 m L of phosphate buffer at p H 6.8 as the dissolution medium.Validation parameters such as the specificity, linearity, accuracy, precision, and robustness were evaluated according to international guidelines, giving results within the acceptable range. The kinetic parameters of drug release were also investigated using model-dependent methods and the dissolution profiles were best described by the Higuchi model. The validated dissolution test can be applied for quality control of this formulation.
文摘To investigate the effects of long-term low dose hormone replacement therapy (HRT) on postmenopaosal women in homone level, cognition score, hippocampus volume, and magnetic resonance spectroscopy (MRS) parameters. Methods A total of 182 postmenopausal women aged 50-87 years were chosen at Peking Union Medical College Hospital and assigned to HRT group and control group. The volunteers of HRT group had taken low dose hormone [ estradiol (E2 ) 0. 5-1.0 mg and progesterone 0.5-2.0 mg, once a day ] for 4-33 years. The concentrations of E2, progesterone, and testosterone were measured using enzyme-linked immunosorbent assay (ELISA). The gene types of apolipoprotein E (ApoE) were measured by polymerase chain reaction, and the subjects with susceptible genes ( ApoE ε3/ε4) of Alzheimer's disease (AD) were screened. Their hippocampus volumes and MRS parameters were obtained through magnetic resonance imaging (MRI), and results in two groups were analyzed by statistical method. Results Compared with control group, the concentrations of E2 at each age stage in HRT group were significantly higher (P 〈0. 05) except the 80-89 years old subgroup; yet, there were no statistical differences in the concentrations of progesterone and testosterone between the two groups. There was no obvious difference in ApoE subtypes distribution between the two groups The results of hippocampus MRI for the subjects with susceptible genes ApoE ε3/ε4 (HRT group 14 cases, control group 11 cases) showed that the ratio of bilateral hippocampus volume to whole brain volume in HRT group (0. 406 ± 0.028) was signiticantlyhigher than control gronp (0.369±0.031, P〈0.05). Theresults of ^1H MRS for the subjects with susceptible genes ApoE ε3/ε4 ( HRT group 12 cases, control group 11 cases) showed that the N-acetylaspartate/total creatine at the area of hippocampus in HRT group ( 1.54±0. 08 ) were significantly higher than control group ( 1.45±0. 13, P 〈 0. 05). Conclusions For postmenopausal women, long-term low dose HRT can maintain the physiological concentration of E2 in plasma. Furthermore, the hippocampus MRI performed on those with ApoE ε3/ε3 genes shows that long-term low dose HRT can prevent hippocampus atrophy, which is beneficial to maintain the brain function and prevent AD.