Inhibitory effect induced by fractional Gaussian noise in neuronal system

We discover a phenomenon of inhibition effect induced by fractional Gaussian noise in a neuronal system. Firstly,essential properties of fractional Brownian motion(fBm) and generation of fractional Gaussian noise(fGn) are presented,and representative sample paths of fBm and corresponding spectral density of fGn are discussed at different Hurst indexes.Next, we consider the effect of fGn on neuronal firing, and observe that neuronal firing decreases first and then increases with increasing noise intensity and Hurst index of fGn by studying the time series evolution. To further quantify the inhibitory effect of fGn, by introducing the average discharge rate, we investigate the effects of noise and external current on neuronal firing, and find the occurrence of inhibitory effect about noise intensity and Hurst index of f Gn at a certain level of current. Moreover, the inhibition effect is not easy to occur when the noise intensity and Hurst index are too large or too small. In view of opposite action mechanism compared with stochastic resonance, this suppression phenomenon is called inverse stochastic resonance(ISR). Finally, the inhibitory effect induced by fGn is further verified based on the inter-spike intervals(ISIs) in the neuronal system. Our work lays a solid foundation for future study of non-Gaussian-type noise on neuronal systems.

Vitamin D,selenium,and antidiabetic drugs in the treatment of type 2 diabetes mellitus with Hashimoto's thyroiditis

BACKGROUND Diabetes and thyroiditis are closely related.They occur in combination and cause significant damage to the body.There is no clear treatment for type-2 diabetes mellitus(T2DM)with Hashimoto's thyroiditis(HT).While single symptomatic drug treatment of the two diseases is less effective,combined drug treatment may improve efficacy.AIM To investigate the effect of a combination of vitamin D,selenium,and hypoglycemic agents in T2DM with HT.METHODS This retrospective study included 150 patients with T2DM and HT treated at The Central Hospital of Shaoyang from March 2020 to February 2023.Fifty patients were assigned to the control group,test group A,and test group B according to different treatment methods.The control group received low-iodine diet guidance and hypoglycemic drug treatment.Test group A received the control treatment plus vitamin D treatment.Test group B received the group A treatment plus selenium.Blood levels of markers of thyroid function[free T3(FT3),thyroid stimulating hormone(TSH),free T4(FT4)],autoantibodies[thyroid peroxidase antibody(TPOAB)and thyroid globulin antibody(TGAB)],blood lipid index[low-density lipoprotein cholesterol(LDL-C),total cholesterol(TC),triacylglycerol(TG)],blood glucose index[fasting blood glucose(FBG),and hemoglobin A1c(HbA1c)]were measured pre-treatment and 3 and 6 months after treatment.The relationships between serum 25-hydroxyvitamin D3[25(OH)D3]level and each of these indices were analyzed.RESULTS The levels of 25(OH)D3,FT3,FT4,and LDL-C increased in the order of the control group,test group A,and test group B(all P<0.05).The TPOAB,TGAB,TC,TG,FBG,HbA1c,and TSH levels increased in the order of test groups B,A,and the control group(all P<0.05).All the above indices were compared after 3 and 6 months of treatment.Pre-treatment,there was no divergence in serum 25(OH)D3 level,thyroid function-related indexes,autoantibodies level,blood glucose,and blood lipid index between the control group,test groups A and B(all P>0.05).The 25(OH)D3 levels in test groups A and B were negatively correlated with FT4 and TGAB(all P<0.05).CONCLUSION The combination drug treatment for T2DM with HT significantly improved thyroid function,autoantibody,and blood glucose and lipid levels.

The neuroprotective effects of the anti-diabetic drug linagliptin against Aβ-induced neurotoxicity

Impaired insulin signaling in Alzheimer’s disease（AD）brains：The insulin signaling pathway is a fundamental physiological mechanism that presents in nearly all vertebrate cells.However,sometimes cells stop responding properly to insulin stimulation.This condition is known as insulin resistance,which is a hallmark of two very common conditions,metabolic syndrome and type 2 diabetes（T2D）.

Excellent effects and possible mechanisms of action of a new antibody–drug conjugate against EGFR-positive triple-negative breast cancer

Background:Triple-negative breast cancer(TNBC)is the most aggressive subtype and occurs in approximately 15%–20%of diagnosed breast cancers.TNBC is characterized by its highly metastatic and recurrent features,as well as a lack of specific targets and targeted therapeutics.Epidermal growth factor receptor(EGFR)is highly expressed in a variety of tumors,especially in TNBC.LR004-VC-MMAE is a new EGFR-targeting antibody–drug conjugate produced by our laboratory.This study aimed to evaluate its antitumor activities against EGFR-positive TNBC and further studied its possible mechanism of antitumor action.Methods:LR004-VC-MMAE was prepared by coupling a cytotoxic payload(MMAE)to an anti-EGFR antibody(LR004)via a linker,and the drug-to-antibody ratio(DAR)was analyzed by HIC-HPLC.The gene expression of EGFR in a series of breast cancer cell lines was assessed using a publicly available microarray dataset(GSE41313)and Western blotting.MDA-MB-468 and MDA-MB-231 cells were treated with LR004-VC-MMAE(0,0.0066,0.066,0.66,6.6 nmol/L),and the inhibitory effects of LR004-VC-MMAE on cell proliferation were examined by CCK-8 and colony formation.The migration and invasion capacity of MDA-MB-468 and MDA-MB-231 cells were tested at different LR004-VCMMAE concentrations(2.5 and 5 nmol/L)with wound healing and Transwell invasion assays.Flow cytometric analysis and tumorsphere-forming assays were used to detect the killing effects of LR004-VC-MMAE on cancer stem cells(MDA-MB-468 and MDA-MB-231 cells).The mouse xenograft models were also used to evaluate the antitumor efficacy of LR004-VC-MMAE in vivo.Briefly,BALB/c nude mice were subcutaneously inoculated with MDA-MB-468 or MDAMB-231 cells.Then they were randomly divided into 4 groups(n=6 per group)and treated with PBS,naked LR004(10 mg/kg),LR004-VC-MMAE(10 mg/kg),or doxorubicin,respectively.Tumor sizes and the body weights of mice were measured every 4 d.The effects of LR004-VC-MMAE on apoptosis and cell cycle distribution were analyzed by flow cytometry.Western blotting was used to detect the effects of LR004-VC-MMAE on EGFR,ERK,MEK phosphorylation and tumor stemness marker gene expression.Results:LR004-VC-MMAE with a DAR of 4.02 were obtained.The expression of EGFR was found to be significantly higher in TNBC cells compared with non-TNBC cells(P<0.01).LR004-VC-MMAE inhibited the proliferation of EGFRpositive TNBC cells,and the ICvalues of MDA-MB-468 and MDA-MB-231 cells treated with LR004-VC-MMAE for 72 h were(0.13±0.02)nmol/L and(0.66±0.06)nmol/L,respectively,which were significantly lower than that of cells treated with MMAE[(3.20±0.60)nmol/L,P<0.01,and(6.60±0.50)nmol/L,P<0.001].LR004-VC-MMAE effectively inhibited migration and invasion of MDA-MB-468 and MDA-MB-231 cells.Moreover,LR004-VC-MMAE also killed tumor stem cells in EGFR-positive TNBC cells and impaired their tumorsphere-forming ability.In TNBC xenograft models,LR004-VC-MMAE at 10 mg/kg significantly suppressed tumor growth and achieved complete tumor regression on day 36.Surprisingly,tumor recurrence was not observed until the end of the experiment on day 52.In a mechanistic study,we found that LR004-VC-MMAE significantly induced cell apoptosis and cell cycle arrest at G/M phase in MDAMB-468[(34±5)%vs.(12±2)%,P<0.001]and MDA-MB-231[(27±4)%vs.(18±3)%,P<0.01]cells.LR004-VC-MMAE also inhibited the activation of EGFR signaling and the expression of cancer stemness marker genes such as Oct4,Sox2,KLF4 and EpCAM.Conclusions:LR004-VC-MMAE showed effective antitumor activity by inhibiting the activation of EGFR signaling and the expression of cancer stemness marker genes.It might be a promising therapeutic candidate and provides a potential therapeutic avenue for the treatment of EGFR-positive TNBC.

Why Don’t We Adequately Identify and Manage Adverse Drug Reactions despite Having the Needed Information?

Importance/Objective: Adverse Drug Reactions (ADRs) are unavoidable, but recognizing and addressing ADRs early can improve wellness and prevent permanent injury. We suggest that available medical information and digital/electronic methods could be used to manage this major healthcare problem for individual patients in real time. Methods: We searched the available digital applications and three literature databases using the medical subject heading terms, adverse drug reaction reporting systems or management, filtered by clinical trial or systemic reviews, to detect publications with data about ADR identification and management approaches. We reviewed the reports that had abstract or summary data or proposed or implemented methods or systems with potential to identify or manage ADRs in clinical settings. Results: The vast majority of the 481 reports used retrospectively collected data for groups of patients or were limited to surveying one population group or class of medication. The reports showed potential and definite associations of ADRs for specific drugs and problems, mostly, but not exclusively, for patients in hospitals and nursing homes. No reports described complete methods to collect comprehensive data on ADRs for individual patients in a healthcare system. The digital applications have ADR information, but all are too cumbersome or incomplete for use in active clinical settings. Several studies suggested that providing information about potential ADRs to clinicians can reduce these problems. Conclusion and Relevance: Although investigators and government agencies agree with the need, there is no comprehensive ADR management program in current use. Informing the patient’s healthcare practitioners of potential ADRs at the point of service has the potential for reduction of these complications, which should improve healthcare and reduce unneeded costs.

Effect of Ultrasound-Guided Transversus Abdominis Plane Block Combined with Lornoxicam on Pain and Recovery Quality After Abdominal Surgery in Patients with Drug Addiction

Objective:This paper aims to analyze the analgesic effect of ultrasound-guided transversus abdominis plane block(TAPB)combined with non-steroidal anti-inflammatory analgesic drug lornoxicam on abdominal surgery in patients with a history of drug addiction.Methods:32 patients aged 18-60 who underwent lower abdominal surgery in the First People's Hospital of Liangshan Yi Autonomous Prefecture and Butuo County People's Hospital of Liangshan Yi Autonomous Prefecture from January 2022 to March 2023 were selected,the patients must have drug abuse history for more than 1 year,with a history of drug withdrawal and relapse.The patients were divided into observation group and control group by the envelope method,with 16 cases in the observation group and 16 cases in the control group.Two groups of patients underwent ultrasound-guided bilateral transversus abdominis plane block after the operation.The observation group was treated with dexmedetomidine hydrochloride 1μg/kg+0.25%ropivacaine hydrochloride 40ml,and the control group was treated with 40ml 0.9%sodium chloride injection,the two groups of patients returned to the ward after operation and given intravenous infusion of lornoxicam for relieving the pain.The visual analogue scale(VAS)score of postoperative pain,the times of rescue analgesia,the time of postoperative anal exhaust,the time of ambulation,nausea and vomiting,withdrawal symptoms,related adverse reactions,and hospitalization days were compared between the two groups.Results:The VAS score of postoperative pain in the observation group was significantly lower than that in the control group,P<0.05.Patients in the observation group used less postoperative rescue analgesics than those in the control group,P<0.05.For postoperative anal exhaust time,the difference between the two groups of patients was relatively small,and the time in the observation group was shorter,P>0.05.The time to get out of bed and the length of hospital stay were not significantly different between the control group and the observation group,P>0.05.The withdrawal symptoms of the patients in the observation group were better,P<0.05,nausea and vomiting,and other adverse reactions were lower in the control group,P<0.05.Conclusion:Ultrasound-guided transversus abdominis plane block combined with lornoxicam can be used to relieve pain in abdominal surgery for patients with drug addiction,which can effectively improve the therapeutic effect of patients and reduce the number of postoperative rescue analgesia.Thus,it has high clinical application value.

Effects of fractal gating of potassium channels on neuronal behaviours

The classical model of voltage-gated ion channels assumes that according to a Markov process ion channels switch among a small number of states without memory, but a bunch of experimental papers show that some ion channels exhibit significant memory effects, and this memory effects can take the form of kinetic rate constant that is fractal. Obviously the gating character of ion channels will affect generation and propagation of action potentials, furthermore, affect generation, coding and propagation of neural information. However, there is little previous research on this series of interesting issues. This paper investigates effects of fractal gating of potassium channel subunits switching from closed state to open state on neuronal behaviours. The obtained results show that fractal gating of potassium channel subunits switching from closed state to open state has important effects on neuronal behaviours, increases excitability, rest potential and spiking frequency of the neuronal membrane, and decreases threshold voltage and threshold injected current of the neuronal membrane. So fractal gating of potassium channel subunits switching from closed state to open state can improve the sensitivity of the neuronal membrane, and enlarge the encoded strength of neural information.

Protective Effect of Interleukin-1β on Motor Neurons after Sciatic Nerve Injury in Rats

Protective effect of interleukin 1β (IL 1β) on motor neurons was studied after peripheral nerve injury. Twenty Wistar rats were divided into 2 groups randomly. The right sciatic nerve of each rat was resected. After silicon tubulization of sciatic nerve in rat, 15 μl 1 ng/ml IL 1β and PBS solution were injected into the silicon capsule respectively. Enzyme histochemistry was performed to show acetyle cholesterase (AchE) and nitric oxide staining (NOS) activity of spinal α motor neurons in spinal segments 2 weeks later. Neurons were counted and the diameter and cross sectional (c/s) area of neurons were analyzed by using computer image analysis system. The results showed that as compared with the normal side, both enzyme activities significantly changed in motor neurons in PBS group. The diameter and c/s area of both neurons changed significantly too ( P< 0 01). These results suggest that exogenous IL 1β protects α motor neurons from degeneration and necrosis after peripheral nerve injury.

Three-dimensional aspects of formulation excipients in drug discovery:a critical assessment on orphan excipients,matrix effects and drug interactions

Formulation/pharmaceutical excipients play a major role in formulating drug candidates,with the objectives of ease of administration,targeted delivery and complete availability.Many excipients used in pharmaceutical formulations are orphanized in preclinical drug discovery.These orphan excipients could enhance formulatability of highly lipophilic compounds.Additionally,they are safe in preclinical species when used below the LD50 values.However,when the excipients are used in formulating compounds with diverse physico-chemical properties,they pose challenges by modulating study results through their bioanalytical matrix effects.Excipients invariably present in study samples and not in the calibration curve standards cause over-/under-estimation of exposures.Thus,the mechanism by which excipients cause matrix effects and strategies to nullify these effects needs to be revisited.Furthermore,formulation excipients cause drug interactions by moderating the pathways of drug metabolizing enzymes and drug transport proteins.Although it is not possible to get rid of excipient driven interactions,it is always advised to be aware of these interactions and apply the knowledge to draw meaningful conclusions from study results.In this review,we will comprehensively discuss a)orphan excipients that have wider applications in preclinical formulations,b)bioanalytical matrix effects and possible approaches to mitigating these effects,and c)excipient driven drug interactions and strategies to alleviate the impacts of drug interactions.

Methodological challenges to control for immortal time bias in addressing drug effects in type 2 diabetes

There are multiple biases in using observational studies to examine treatment effects such as those from prevalent drug users, immortal time and drug indications. We used renin angiotensin system(RAS) inhibitors and statins as reference drugs with proven efficacies in randomized clinical trials(RCTs) and examined their effectiveness in the prospective Hong Kong Diabetes Registry using adjustment methods proposed in the literature. Using time-dependent exposures to drug treatments yielded greatly inflated hazard ratios(HR) regarding the treatment effects of these drugs for cardiovascular disease(CVD) in type 2 diabetes. These errors were probably due to changing indications to use these drugs during follow up periods, especially at the time of drug commencement making time-dependent analysis extremely problematic. Using time-fixed analysis with exclusion of immortal time and adjustment for confounders at baseline and/or during follow-up periods, the HR of RAS inhibitors for CVD was comparable to that in RCT. The result supported the use of the Registry for performing pharmacoepidemiological analysis which revealed an attenuated low low-density lipoprotein cholesterol related cancer risk with RAS inhibitors. On the other hand, time-fixed analysis with including immortal time and adjustment for confounders at baseline and/or during follow-up periods, the HR of statins for CVD was similar to that in the RCT. Our results highlight the complexity and difficulty in removing these biases. We call for validations of the methods to cope with immortal time and drug use indications before applying them to particular research questions, so to avoid making erroneous conclusions.

Preventive Effects of Five Drugs on Mycoplasma Pneumonia of Swine (MPS)

The paper was to explore the preventive effects of five drugs on mycoplasma pneumonia of swine （MPS） and to provide reference for clinical medication of pig farms in Hainan Province. A total of 444 health piglets were randomly divided into 6 groups, including five medication groups （72 piglets in group A, 74 pig- lets in group B, 72 piglets in group C, 76 piglets in group D, 76 piglets in group E） and one control group （74 piglets）. The piglets in experimental groups were treated drugs once a day for successive 5 days at 30, 60, 90, 120 and 150 of age. The piglets in control group were free of medication. At 70 and 140 days of age, 15 piglets of each group were randomly selected to collect their blood sermn. The Mycoplasma hyopneumoniae （M-Hyo） antibodies in serum were measured by en- zyme-linked immunosorbent assay （ELISA）. During the experiment, the incidence rates of respiratory disease, lung lesion, feed conversion rate, average daily gain （ADG）, and mortality rate of pigs were also observed and recorded. The results showed that the five drugs had significant difference in preventative effects. Group C （Zhiyuanjing group） received the best preventive effect and the highest economic benefits. Compared with control group, the ADG and feed conversion rate in group C were increased by 7.53% and 9.09%, respectively; the incidence rate of respiratory disease was reduced by 13.44% and lung lesion was alleviated by 81.43% ; and the earnings of each pig could rise by 132.70 yuan. The preventative effect and economic benefit of the drugs was sequenced by Chansu Kechuanling and Bingchan Kechuanwang. Wante Feilin and amoxicillin had weaker preventive effects against MPS but greatly influenced growth performance of pigs, so they should be used alternatively with other drugs.

Protective effect of melatonin on neurons after oxidative-stress injury

BACKGROUND: It has been suggested that melatonin (MT) can protect secondary neuronal injury. However, the protective effect of MT on neuronal injury in ischemia/reperfusion models in vitro still has not been proved. OBJECTIVE: To investigate the protective effect of MT on central ischemic injury of nerve cells and analyze its possible mechanism. DESIGN: Contrast observational study. SETTING: Department of Biochemistry and Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology. MATERIALS: Rats aged 7-8 days and weighing 10-12 g were provided by Medical Experimental Animal Center, Tongji Medical College, Huazhong University of Science and Technology. MT was provided by Sigma Company, USA. METHODS: The experiment was carried out in the Laboratory of Biochemistry and Molecular Biology, Tongji Hospital, Huazhong University of Science and Technology from October 2002 to March 2004. The effects of MT on the neurodegeneration induced by oxygen-glucose-deprivation (OGD) were tested in cultured rat cerebellar granule cells. Neuron damage was quantitatively assessed by Typan Blue exclusion and MTT assay at different time points after oxygen-glucose-deprivation (90 minutes). DNA gel electrophoresis and acridine orange stain were performed to determine the nature of cell damage. And fluorescence spectrophotometer was used for quantification of intracellular malondialdehyde (MDA) at various time intervals. MAIN OUTCOME MEASURES: Correlation between degrees of neuronal injury and reperfusion times, apoptosis, and production of MDA in cells. RESULTS: ① The neuron injury was aggravated with reperfusion time. ② The protective effect of MT was time- and dose-dependent when its concentration was not higher than 10 μmol/L. ③ When neurons were exposed to OGD for 90 minutes, part of the cells exhibited typical features of apoptosis: internucleosomal DNA condensation and DNA ladder on agarose gel electrophoresis. MT added to cells recovering from OGD exerted neuroprotective action against OGD-induced apoptosis. ④ In OGD exposed cultures, the production of MDA burst 12 hours after OGD, while MT significantly decreased the generation of MDA (P < 0.05) in a time-dependent manner. CONCLUSION: MT may have therapeutic potential in the prevention and treatment of ischemic/hypoxic neuronal damage, and this neuroprotective action may contribute to the antioxidant nature of MT.

The Effects of Antiretroviral Drugs on the Absorbance Characteristics of HIV-Infected Blood

In the twenty first century research works, there may be a need to achieve a more reliable research result through a synergy between engineers and biological researchers. The peak absorbance data for various interacting systems were measured. These were used to show that the antiretroviral drug has the effect of increasing the peak absorbance values of both the uninfected and infected blood components, i.e., the drugs are made able to increase the light absorption capacity of the blood cells. For drug 2 that contains three components including Efavirenz, the drug effect on lymphocytes was increased by about 38% for patients that had been on antiretroviral drug treatment. Mathematical models were proposed and used in determining the coating effectiveness of antiretroviral drugs in the presence and absence of HIV. The use of the findings of this work by pharmaceutical industries may help in the search for more effective antiretroviral drugs for the treatment of HIV patients.

Protective effects of blueberry anthocyanin extracts on hippocampal neuron damage induced by extremely low-frequency electromagnetic field

The protective effects of blueberry anthocyanin extracts against damage induced by extremely lowfrequency electromagnetic field(ELF-EMF)were investigated in a rat model.Wistar rats were exposed to ELF-EMF with or without the administration of blueberry anthocyanin extracts(50,100,and 200 mg/kg per day intragastrically once a day)for 30 days.Blueberry anthocyanin extracts supplementation inhibited the decrease in Nissl substance levels,cell membrane integrity,and mitochondrial membrane potential induced by ELF-EMF;prevented the increase in nitric oxide,malondialdehyde,and Ca2+concentrations;suppressed superoxide dismutase and glutathione depletion;and enhanced the cognitive ability of the rats exposed to ELF-EMF.The protective effects of blueberry anthocyanin extracts against hippocampal neuron injury caused by ELF-EMF were dose-dependent.These results demonstrated that blueberry anthocyanin extracts suppress hippocampal neuron injury caused by ELF-EMF by inhibiting cell membrane damage and oxidative stress pathways,and suggested that blueberry anthocyanin treatment potentially prevents hippocampal neuron injury.

Temperature Effects on Information Capacity and Energy Efficiency of Hodgkin-Huxley Neuron

Recent experimental and theoretical studies show that energy efficiency, which measures the amount of infor- mation processed by a neuron with per unit of energy consumption, plays an important role in the evolution of neural systems. Here we calculate the information rates and energy efficieneies of the Hodgkin-Huxley （HH） neuron model at different temperatures in a noisy environment. It is found that both the information rate and energy efficiency are maximized by certain temperatures. Though the information rate and energy efficiency cannot be maximized simultaneously, the neuron holds a high information processing capacity at the tempera- ture corresponding to the maximal energy efficiency. Our results support the idea that the energy efficiency is a selective pressure that influences the evolution of nervous systems.

Intercalation of Ciprofloxacin in Naturally Occurring Smectite from Bana: Potentiality as Drug Delivery System and Antimicrobial Effects on <i>Escherichia coli</i>and <i>Staphylococcus aureus</i>

Ciprofloxacin (CFX) was loaded on Bana clay (Cameroon) and CFX loaded-clays have been evaluated as drug delivery system. Raw clays and CFX loaded compounds have been characterized by some physico-chemicals methods. In vitro release studies have been done in gastric and phosphate buffer experimental mediums;bacteriological studies have been made up on Escherichia coli and Staphylococcus aureus. X-ray diffractometry patterns of loaded compounds show a basal spacing increasing due to CFX intercalation. On Fourier-Transformed Infrared spectrometry spectra, appearance of CFX characteristic bands and shifting of certain bands already presents on clay confirmed CFX intercalation. After 96 h of CFX released from release mediums, prolonged and continue profiles have been observed. Diffusion tests displayed an inhibition radius of ~2 cm on gelose seeded with Escherichia coli and Staphylococcus aureus due to CFX. The overall results show a modified release of ciprofloxacin with an effective antibacterial activity, giving the way for a new ciprofloxacin drug delivery system using Bana clay as carrier.

Late Protective Effects of the Anticalmodulin Drug Fluphenazine on Carbon Tetrachloride-induced Liver Necrosis

Fluphenazine (FP) treatment (50mg/kg bw, ip in saline) 30 min before or 6 or 10 h after CCl4 administration (1 ml/kg ip in olive oil) significantly prevented the liver necrosis produced by the hepatotoxin at 24 h. FP had enhancing effects on the covalent binding of CCl4 reactive metabolites to cellular constituents and on CCl4 induced lipid peroaldation.FP lowered bOdy temperature of the CCl4-poisoned animals during the 24 h observation period. The obtained results are compatible but do not prove the hypothesis that calmodulin (CaM) had participation in late occurring events preceding necrosis. FP lowering action on body temperature, however, might also play a role in the effects of this drug on the onset of CCl4 induced liver necrosis. FP levels in liver tissue as determined by gas chromatography-mass spectrometry evidenced the presence of the drug in amounts suffi cient to inhibit CaM and that suggests that not all preventive effects of FP are due to its indirect actions on the central nervous system via decreased body temperature

Protective effect of sodium valproate on motor neurons in the spinal cord following sciatic nerve injury in rats

BACKGROUND: Sodium valproate (VPA) is used to be an effective anti-epileptic drug. VPA possesses the characteristics of penetrating rapidly through the blood-brain barrier (BBB) and increasing levels of Bcl-2 and growth cone-associated protein (GAP) 43 in spinal cord. OBJECTIVE: To observe the effect of VPA on Bcl-2 expression and motor neuronal apoptosis in spinal cord of rats following sciatic nerve transection. DESIGN: Randomized controlled experiment. SETTING: Department of Hand Surgery and Microsurgery, Wuhan Puai Hospital. MATERIALS: A total of 30 male healthy SD rats of clean grade and with the body mass of 180-220 g were provided by Experimental Animal Center of Medical College of Wuhan University. Sodium Valproate Tablets were purchases from Hengrui Pharmaceutical Factory, Jiangsu. METHODS: The experiment was performed in the Central Laboratory of Wuhan Puai Hospital and Medical College of Wuhan University from February to May 2006. Totally 30 rats were randomly divided into two groups: treatment group (n =15) and model group (n =15). Longitudinal incision along backside of right hind limbs of rats was made to expose sciatic nerves, which were sharply transected 1 cm distal to the inferior margin of piriform muscle after nerve liberation under operation microscope to establish sciatic nerve injury rat models. Sodium Valproate Tablets were pulverized and diluted into 50 g/L suspension with saline. On the day of operation, the rats in the treatment group received 6 mL/kg VPA suspension by gastric perfusion, once a day, whereas model group received 10 mL/kg saline by gastric perfusion, once a day. L4-6 spinal cords were obtained at days 1, 4, 7, 14 and 28 after operation, respectively. Terminal deoxyribonucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL) technique and immunohistochemical method (SP method) were used to detect absorbance (A) of neurons with positive Bcl-2 expression. Apoptotic rate of cells (number of apoptotic cells/total number of cells×100%) was calculated. MAIN OUTCOME MEASURES: A value of neurons with positive Bcl-2 expression and apoptotic rate in spinal cord of rats in the two groups. RESULTS: A total of 30 SD rats were involved in the result analysis. ①expression of positive Bcl-2 neurons: A value of positive Bcl-2 neurons were 0.71±0.02, 0.86±0.04, 1.02±0.06 at days 4, 7 and 14, respectively after operation in the treatment group, which were obviously higher than those in the model group (0.62±0.03, 0.71±0.05, 0.89±0.04, t = 3.10-4.50, P < 0.05). ②apoptotic result of motor neurons: Apoptotic rate of motor neurons in spinal cord was (6.91±0.89)% and (15.12±2.34)% at days 7 and 14 in the treatment group, which was significantly lower than those in the model group [(9.45±1.61)%, (19.35±0.92)%, t = 2.39, 3.03. P < 0.05]. CONCLUSION: VPA can increase expression of Bcl-2 in spinal cord and reduce neuronal apoptosis in rats following sciatic nerve injury, and has protective effect on motor neuron in spinal cord of rats.

Effect of polygonatum polysaccharide on the hypoxia-induced apoptosis and necrosis in in vitro cultured cerebral cortical neurons from neonatal rats

BACKGROUND： Cardiocerebrovascular diseases induced cerebral circulation insufficiency and senile vascular dementia can result in ischemic/hypoxic apoptosis of central neurons, which we should pay more attention to and prevent and treat as early as possible. Traditional Chinese medicine possesses the unique advantage in this field. Polygonatum, a Chinese herb for invigorating qi, may play a role against the hypoxic apoptosis of brain neurons. OBJECTIVE ： To observe the protective effect of polygonatum polysaccharide on hypoxia-induced apoptosis and necrosis in cerebral cortical neurons cultured in vitro. DESIGN： A comparative experiment.SETTING： Laboratory of Cell Biology, Institute of Basic Medical Sciences, Jiangxi Provincial Academy of Traditional Chinese Medicine. MATERIALS： The experiment was carried out in the Laboratory of Cell Biology, Institute of Basic Medical Sciences, Jiangxi Provincial Academy of Traditional Chinese Medicine from November 2003 to April 2005. Totally 218 Wistar rats （male or female） of clean degree within 24 hours after birth were purchased from the animal center of Jiangxi Medical College （certification number was 021-97-03）. METHODS：① Preparation of cerebral cortical neurons of rats： The cerebral cortical tissues were isolated from the Wistar rats within 24 hours after birth, and prepared to single cell suspension, and the cerebral cortical neurons of neonatal rats were in vitro cultured in serum free medium with Neurobasal plus B27 Supplement. ② Observation on the non-toxic dosage of polygonatum polysaccharide on neurons： After the neurons were cultured for 4 days, polygonatum polysaccharide of different dosages （1-20 g/L） was added for continuous culture for 48 hours, the toxicity and non-toxic dosage of polygonatum polysaccharide on neurons were observed and detected with trypan blue staining. ③Grouping： After hypoxia/reoxygenation, the cultured neurons were divided into normal control group, positive apoptotic group and polygonatum polysaccharide group. In the normal control group, the neurons were cultured at 37℃ in CO2 with the volume fraction of 0.05 under saturated humidity for 6 days. In the apoptotic positive group, the neurons were cultured with hypoxia for 12 hours after 4-day culture, and followed by reoxygenation for 48 hours. In the polygonatum polysaccharide group, polygonatum polysaccharide with the terminal concentration of 0.5, 1 and 1.5 g/L was added to some neurons at 10 hours before the hypoxia culture, and then the neurons were cultured with hypoxia for 12 hours, followed by reoxygenation for 48 hours; polygonatum polysaccharide with the terminal concentration of 0.5, 1 and 1.5 g/L was added to the other neurons at 12 hours after hypoxia followed by reoxygenation for 48 hours.④ The Hoechst33342 fluorescence staining, Annexin V/PI flow cytometer, appearance of DNA agarose gel electrophoresis gradient strap and immunohistochemical staining were used to observe the expressions of Bcl-2, Bax and Caspase-3 apoptotic and anti-apoptotic proteins and the ratio of Bcl-2/Bax, and observe the effect of polygonatum polysaccharide against the hypoxic apoptosis of cerebral cortical neurons of neonatal rats. MAIN OUTCOME MEASURES： ① Toxicity and non-toxic dosage of polygonatum polysaccharide on neurons;② Apoptotic rate of neurons detected with Hoechst33342 fluorescence staining;③ Early apoptotic rate and necrotic rate of neurons detected with Annexin V/PI flow cytometer; ④DNA agarose gel electrophoresis ladder-like strap appeared or not;⑤ Expressions of Bcl-2, Bax and Caspase-3 apoptotic and anti-apoptotic proteins and the ratio of Bcl-2/Bax. RESULTS：① Polygonatum polysaccharide within 6 g/L had no cytotoxicity on the normal cultured cerebral cortical neurons （P 〉 0.05）. ②The apoptotic rates of neurons detected with Hoechst33342 fluorescence staining had significant differences between the polygonatum polysaccharide groups and positive apoptosis group added to neurons at 10 hours before the hypoxia culture [（13.00±4.52）%,（12.72±2.15）%, （11.80±1.18）%,（38.03±1.05）%, P 〈 0.01], and had no significant differences between the polygonatum polysaccharide groups and positive apoptosis group added to neurons at 12 hours after the hypoxia culture （36.77±1.45）%, （36.60±1.61）%, （36.37±2.02）%, （38.03±1.05）%, P 〉 0.05].③ Annexin V/PI flow cytometer detected that the anti-necrotic effect was enhanced with the increased concentration of polygonatum polysaccharide within 0.5-1.5 g/L （P 〈 0.01）. Polygonatum polysaccharide of 0.5-1.5 g/L added before hypoxia could significantly decrease the apoptotic rate of neurons induced by hypoxia/reoxygenation （P 〈 0.01）. ④ No DNA agarose gel electrophoresis ladder-like strap appeared in the groups with polygonatum polysaccharide of 0.5-1.5 g/L added at 10 hours before hypoxia;⑤ After Polygonatum polysaccharide of 0.5-1.5 g/L was added before hypoxia, the expression of Bcl-2 protein of hypoxic neurons was increased （P 〈 0.01）, and those of Bax protein and Caspase-3 protein were reduced （P 〈 0.01）, and the ratio of Bcl-2/Bax was increased （P 〈 0.01）. CONCLUSION： Polygonatum polysaccharide within 6 g/L has no cytotoxicity on the normal cultured cerebral cortical neurons. Polygonatum polysaccharide of 0.5-1.5 g/L added before hypoxia plays a role agains necrosis of neurons induced by hypoxia. Polygonatum polysaccharide of 0.5-1.5 g/L can significantly reduce the apoptosis of neurons induced by hypoxia through up-regulating the expression of Bcl-2 protein, down-regulating the expressions of Bax protein and Caspase-3 protein, and increasing the ratio of Bcl-2/Bax.