尿钠/尿钾对冠心病患者PCI术后造影剂诱导急性肾损伤发生的诊断价值

目的探讨尿钠/尿钾对冠心病患者经皮冠状动脉介入治疗(PCI)术后造影剂诱导急性肾损伤(CI-AKI)发生的诊断价值。方法选取该院2017年11月至2020年9月收治的行PCI术的冠心病患者368例作为研究对象,根据PCI术后接触造影剂(碘对比剂)3 d内肌酐水平分为CI-AKI组(76例)和非CI-AKI组(292例)。采用全自动生化分析仪检测所有患者尿液中尿钠、尿钾水平,计算尿钠/尿钾。采用受试者工作特性曲线(ROC曲线)分析尿钠/尿钾对冠心病患者PCI术后CI-AKI的诊断价值;采用Logistic分析影响冠心病患者PCI术后CI-AKI的因素。结果与CI-AKI组比较,非CI-AKI组男性比例、左室射血分数(LVEF)水平均升高,体质量指数、糖尿病史比例、白细胞计数、空腹血糖、超敏C反应蛋白(hs-CRP)、肾小球滤过率(eGFR)、尿钠、尿钠/尿钾水平均降低,差异均有统计学意义(P<0.05)。ROC曲线分析结果显示,尿钠/尿钾预测冠心病患者PCI术后CI-AKI的ROC曲线下面积为0.773,截断值为5.56,其灵敏度为71.10%,特异度为74.30%。Logistic回归分析结果显示,hs-CRP、eGFR、尿钠、尿钠/尿钾是影响冠心病患者PCI术后发生CI-AKI的危险因素(P<0.05),LVEF是影响冠心病患者PCI术后发生CI-AKI的保护因素(P<0.05)。结论尿钠/尿钾对冠心病患者PCI术后CI-AKI的发生具有一定的诊断价值,是冠心病患者PCI术后发生CI-AKI的危险因素,在临床上具有一定价值。

测定尿液钠或血清低钠离子浓度的一种电极法

目的介绍一种低于仪器检测下线的钠离子浓度电极测定方法。方法用生理盐水与检测样本按照一定体积比例混匀,在迅达DSI905型电解质分析仪上测定混匀后的样本钠离子浓度,经换算得出检测样本的钠离子浓度。结果该法测定钠离子浓度精密度较高,x=133.2mmol/L,s=1.05,CV=1.5%,能满足临床要求。结论解决了低于仪器检测下线钠离子浓度不能用电极法直接测定的矛盾,特别对尿钠离子浓度测定尤为重要。

Effect of atrial natriuretic peptide on ischemia-reperfusion injury in a porcine total hepatic vascular exclusion model

AIM： To evaluate the effect of ANP on warm I/R injury in a porcine THVE model.METHODS： Miniature pigs （mini-pigs） weighing 16-24 kg were observed for 120 min after reperfusion following 120 min of THVE. The animals were divided into two groups. ANP （0.1 μg/kg per min） was administered to the ANP group （n = 7）, and vehicle was administered to the control group （n = 7）. Either vehicle or ANP was intravenously administered from 30 min before the THVE to the end of the experiment. Arterial blood was collected to measure AST, LDH, and TNF-α. Hepatic tissue blood flow （HTBF） was also measured. Liver specimens were harvested for p38 MAPK analysis and histological study. Those results were compared between the two groups.RESULTS： The AST and LDH levels were lower in the ANP group than in the control group; the AST levels were significantly different between the two groups （60 min： 568.7 ± 113.3 vs 321.6 ± 60.1, P = 0.038 〈 0.05, 120 rain： 673.6± 148.2 vs 281.1±44.8, P = 0.004 〈 0.01）. No significant difference was observed in the TNF-α levels between the two groups. HTBF was higher in the ANP group, but the difference was not significant. A significantly higher level of phosphorylated p38 MAPK was observed in the ANP group compared to the control group （0min： 2.92± 1.1 vs 6.38 ±1.1,,P= 0.011 〈 0.05）.Histological tissue damage was milder in the ANP group than in the control group.CONCLUSION： Our results show that ANP has a protective role in I/R injury with p38 MAPK activation in a porcine THVE model.

Increased N-terminal pro-brain natriuretic peptide level predicts atrial fibrillation after surgery for esophageal carcinoma

AIM: To evaluate the value of plasma N-terminal pro- brain natriuretic peptide (NT-proBNP) level for predicting postoperative atrial fibrillation (AF) in patients undergoing surgery for esophageal carcinoma. METHODS: NT-proBNP levels were measured in 142 patients 24 h before and 1 h after surgery for esophageal carcinoma. All patients having a preoperative cardiac diagnosis by electrocardiogram (ECG), remained under continuous monitoring for at least 48 h after surgery, and then underwent clinical cardiac evaluation until discharge. RESULTS: Postoperative AF occurred in 11 patients (7.7%). AF patients were significantly older (69.6 ± 12.2 years vs 63.4 ± 13.3 years, P = 0.031) than non-AF patients. There were no significant differences in history of diabetes mellitus, sex distribution, surgical approach, anastomosis site, intraoperative hypotension and postoperative fever. The preoperative plasma NT-proBNP level was significantly higher in patients who developed postoperative AF (121.3 ± 18.3 pg/mL vs 396.1 ± 42.6 pg/mL, P = 0.016). After adjustment for age, gender, chronic obstructive pulmonary disease (COPD), history of cardiac diseases, hypertension, postoperative hypoxia and thoracic-gastric dilation, NT-proBNP levels were found to be associated with the highest risk factor for postoperative AF (odds ratio = 4.711, 95% CI = 1.212 to 7.644, P = 0.008).CONCLUSION: An elevated perioperative plasma BNP level is a strong and independent predictor of postoperative AF in patients undergoing surgery for esophageal carcinoma. This finding has important implications for identifying patients at higher risk of postoperative AF who should be considered for preventive antiarrhythmic therapy.

Localization of ANP-synthesizing cells in rat stomach

AIM: To study the morphological positive expression of antrial natriuretic peptide (ANP)-synthesizing cells and ultrastructural localization and the relationship between ANP-synthesizing cells and microvessel density in the stomach of rats and to analyze the distribution of the three histologically distinct regions of ANP-synthesizing cells. METHODS: Using immunohistochemical techniques, we studied positive expression of ANP-synthesizing cells in rat stomach. A postembedding immunogold microscopy technique was used for ultrastructural localization of ANP-synthesizing cells. Microvessel density in the rat stomach was estimated using tannic acid-ferric chloride (TAFC) method staining. Distribution of ANP-synthesizing cells were studied in different regions of rat stomach histochemically. RESULTS: Positive expression of ANP-synthesizing cells were localized in the gastric mucosa of rats. Localization of ANP-synthesizing cells identified them to be enterochrochromaffin cells (EC) by using a postembedding immunogold electron microscopy technique. EC cells were in the basal third of the cardiac mucosa region. ANP-synthesizing cells existed in different regions of rat stomach and its density was largest in the gastric cardiac region, and the distribution order of ANP-synthesizing cells in density was cardiac region, pyloric region and fundic region in mucosa layer. We have also found a close relationship between ANP-synthesizing cells and microvessel density in gastric mucosa of rats using TAFC staining. CONCLUSION: ANP-synthesizing cells are expressedin the gastric mucosa. EC synthesize ANP. There is a close relationship between ANP-synthesizing cells and microvessel density in gastric mucosa of rats.The distribution density of ANP-synthesizing cells is largest in the gastric cardiac region.

The presence of ANP in rat peritoneal mast cells

Atrial natriuretic peptide （ANP） is an important component of the natriuretic peptide system. A great role in many regulatory systems is played by mast cells. Meanwhile involvement of these cells in ANP activity is poorly studied. In this work, we have shown the presence of ANP in rat peritoneal mast cells. Pure fraction of mast cells was obtained by separation of rat peritoneal cells on a Percoll density gradient. By Westem blotting, two ANP-immunoreactive proteins of molecular masses of 2.5 kDa and 16.9 kDa were detected in lysates from these mast cells. Electron microscope immunogold labeling has revealed the presence of ANP-immunoreactive material in storage, secreting and released granules of mast cells. Our findings indicate the rat peritoneal mast cells to contain both ANP prohormone and ANP. These both peptides are located in mast cell secretory granules and released by mechanism of degranulation. It is discussed that many mast cell functions might be due to production of natriuretic peptides by these cells.

PI 3-kinase pathway is responsible for antiapoptotic effects of atrial natriuretic peptide in rat liver transplantation

AIM： To investigate the in vivo effect of atrial natriuretic peptide （ANP） and its signaling pathway during orthotopic rat liver transplantation.METHODS： Rats were infused with NaCI, ANP （5 μg/ kg）, wortmannin （WH, 16μg/kg）, or a combination of both for 20 min. Livers were stored in UW solution （4℃） for 24 h, transplanted and reperfused. Apoptosis was examined by caspase-3 activity and TUNEL staining. Phosphorylation of Akt and Bad was visualized by Western blotting and phospho-Akt-localization by confocal microscopy.RESULTS： ANP-pretreatment decreased caspase-3 activity and TUNELopositive cells after cold ischemia, indicating antiapoptotic effects of ANP in vivo. The an- tiapoptotic signaling of ANP was most likely caused by phosphorylation of Akt and Bad, since pretreatment with PI 3-kinase inhibitor WM abrogated the ANP-induced reduction of caspase-3 activity. Interestingly, analysis of liver tissue by confocal microscopy showed translocation of phosphorylated Akt to the plasma membrane of hepa- tocytes evoked by ANP.CONCLUSION： ANP activates the PI-3-kinase pathway in the liver in vivo leading to phosphorylation of Bad an event triggering antiapoptotic signaling cascade in ischemic liver.

Dendroaspis natriuretic peptide relaxes gastric antral circular smooth muscle of guinea-pig through thecGMP/cGMP-dependent protein kinase pathway

AIM: To systematically investigate if cGMP/cGMP- dependent protein kinase G (PKG) signaling pathway may participate in dendroaspis natriuretic peptide (DNP)-induced relaxation of gastric circular smooth muscle. METHODS: The content of cGMP in guinea pig gastric antral smooth muscle tissue and perfusion solution were measured using radioimmunoassay; spontaneous contraction of gastric antral circular muscles recorded using a 4-channel physiograph; and Ca2+-activated K+ currents (IK(Ca)) and spontaneous transient outward currents (STOCs) in isolated gastric antral myocytes were recorded using the whole-cell patch clamp technique. RESULTS: DNP markedly enhanced cGMP levels in gastric antral smooth muscle tissue and in the perfusion medium. DNP induced relaxation in gastricantral circular smooth muscle, which was inhibited by KT5823, a cGMP-dependent PKG inhibitor. DNP increased IK(Ca). This effect was almost completely blocked by KT5823, and partially blocked by LY83583, an inhibitor of guanylate cyclase to change the production of cGMP. DNP also increased STOCs. The effect of DNP on STOCs was abolished in the presence of KT5823, but not affected by KT-5720, a PKA-specific inhibitor. CONCLUSION: DNP activates IK(Ca) and relaxes guinea-pig gastric antral circular smooth muscle via the cGMP/PKG-dependent singling axis instead of cAMP/ PKA pathway.

CHANGES OF PLASMA ENDOTHELIN AND ATRIAL NATRIURETIC PEPTIDE DURING THE ONSET AND AFTER TERMINATION OF PAROXYSMAL SUPRAVENTRICULAR TACHYCARDIA

Radioimmunoassays were used to measure the concentration changes of plasma endothelin(ET) and atrial natriuretic peptide(ANP) during the onset and after termination of paroxysmal supraventricular tachycardia(SVT). 30 cases were reviewed and compansons with 42 normal subjects were made. There are very significant differences(P<0.0001) in the concentration changes of both plasma ET and ANP during the onset and 30 minutes after the termination of SVT. During the onset period of SVT. the plasma ET and ANP were markedly elevated and 30 minutes after its termination they were lowered significantly, but their concentrations were still 2-fold higher than ihose of the control group. As the biological effects of ANP and ET are antagonistic to each other. their parallel elevation and lowering of plasma concentrations during and.after the termination of SVT reveal that these 2 hormones parucipate in the pathophysiological process of SVT. This phenomenon is possibly one of the homeostatic regulatory functions in the organism.

Effects of vanadate on the activities of mice glucokinase and hexokinase

This study aimed at acquiring knowledge on the hypoglycemic mechanisms of sodium metavanadate (SMV) showed that the liver glucokinase and muscle hexokinase activities increased rapidly after oral SMV was given, and that the blood glucose level was correlated closely with the activities of the two enzymes but not with the insulin level; which indicated that SMV could improve the altered glucose phosphorylation in diabetic mice independently of stimulating insulin secretion. This was probably one of the mechanisms of hypoglycemic effects of SMV.

Elevated plasma levels of N-terminal pro-brain natriuretic peptide in patients with chronic hepatitis C during interferon-based antiviral therapy

AIM: To investigate plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), an established marker of cardiac function, in patients with chronic hepatitis C during interferon-based antiviral therapy. METHODS: Using a sandwich immunoassay, plasma levels of NT-proBNP were determined in 48 patients with chronic hepatitis C at baseline, wk 24 and 48 during antiviral therapy and at wk 72 during follow-up.RESULTS: Plasma NT-proBNP concentrations were significantly increased (P < 0.05) at wk 24, 48 and 72 compared to the baseline values. NT-proBNP concentrations at baseline and wk 24 were closely correlated (r = 0.8; P < 0.001). At wk 24, 7 (14.6%) patients had NT-proBNP concentrations above 200 ng/L compared to 1 (2%) patient at baseline (P = 0.059). Six of these 7 patients had been treated with high-dose IFN-α induction therapy. In multiple regression analysis, NT-proBNP was not related to other clinical parameters, biochemical parameters of liver disease or virus load and response to therapy.CONCLUSION: Elevated levels of NT-proBNP during and after interferon-based antiviral therapy of chronic hepatitis C may indicate the presence of cardiac dysfunction, which may contribute to the clinical symptoms observed in patients during therapy. Plasma levels of NT-proBNP may be used as a diagnostic tool and for guiding therapy in patients during interferon-based antiviral therapy.

Science Letters:Brain natriuretic peptide: A potential indicator of cardiomyogenesis after autologous mesenchymal stem cell transplantation?

We observed in a pilot study that there was a transient elevation of brain natriuretic peptide (BNP) level shortly after the transplantation in the patient with ischemic heart failure, which is unexplainable by the simultaneous increase of the cardiac output and six-minute walk distance. Similar findings were observed in the phase I trial. We postulated on the basis of the finding of Fukuda in vitro that this transient elevation of BNP level against the improvement of cardiac function and exercise capacity might indicate cardiomyogenesis in patients after mesenchymal stem cell transplantation. Further study is warranted to verify the hypothesis.

EFFECT OF ELECTROACUPUNCTURE ON PLASMA ANGIOTENSIN-ALDOSTERONE AND ATRIAL NATRIURETIC POLYPEPTIDE IN RABBITS WITH ACUTE CEREBRAL INFARCTION

Objective: To observe the therapeutic effect of electroacupuncture (EA) on plasma angiotensin (Ang Ⅱ), aldosterone (ALD) and atrial natriuretic polypeptide (ANP) contents in experimental cerebral infarction rabbits for analyzing the underlying mechanism of acupuncture in ameliorating blood supply of the brain tissue. Methods: A total of 80 rabbits were randomized into control (n = 8), pseudo-operation (n = 24), model (n = 24) and EA (n = 24) groups. Cerebral infarction model was established by infusion of self-thrombus into the carotid artery. EA (1 mA, 2 Hz) was applied to 'Baihui'(百会 GV 20) and 'Shuigou'(水沟 GV 26) for 30 min, once every 12 hours. Plasma Ang Ⅱ, ALD and ANP contents were detected with radioimmunoassay method. In the later 3 groups, blood samples were taken at 6 h, 24 h and 48 h after cerebral ischemia. Results: Compared with control and pseudo-operation groups, Ang Ⅱ and ALD contents of model group at 6 h, 24 h and 48 h after cerebral ischemia increased significantly while plasma ANP of the 3 time-courses of model group decreased considerably (P<0.01). In comparison with model group, results showed that Ang-Ⅱ and ALD contents of EA group decreased significantly whereas ANP level of EA group increased strikingly (P<0.01). Conclusion: Electroacupuncture has the effects of raising plasma ANP level and lowering plasma Ang-Ⅱ and ALD in cerebral infarction rabbits.

Plasma brain natriuretic peptide and atria natriuretic peptide as predictors for diastolic heart failure in patients with type 2 diabetes mellitus

Objective To study the change of diastolic cardiac function in diabetic patients and to determine the diagnostic value of plasma brain natriuretic peptide （BNP） and atria natriuretic peptide （ANP） for diastolic heart failure in patients with type 2 diabetes mellitus. Methods Twelve healthy subjects and seventy-one diabetic patients were included in the study. Plasma BNP and ANP were measured with immtmoradiometic assay. Results Plasma levels of BNP and ANP increased significantly with increased severity of diastolic heart dysfunction. The ratio of E/A had significant negative correlation with the plasma levels ofBNP （r=0.669,P〈0.001） and ANP （r=0.579, P〈0.01）. AUC of ANP and BNP in ROC model was 91.9% and 65.3%, respectively. Conclusions The plasma level of BNP might be a valuable predictor for differential diagnosis of diastolic cardiac function in diabetic patients.

慢性阻塞性肺疾病急性加重期患者体液离子含量的变化

目的:了解慢性阻塞性肺疾病(COPD)患者体液离子含量的变化。方法:选择46例合并肺心病的COPD急性加重期患者,测定其血清、红细胞、白细胞及24 h尿K、Na、Ca、Mg离子含量。结果:患者白细胞Ca增高,红细胞Ca、Mg、K及白细胞Mg、血清Mg、Na均显著降低。红细胞Mg与白细胞Mg显著正相关。该组患者尿Ca增多占54%,尿K、Na、Mg减低者分别占92%,65%及32%。结论:COPD患者存在K、Mg缺失,用红细胞Mg评价机体的Mg状态更具有实用性。

Effects of temperature and sodium carboxylate additives on mineralization of calcium oxalate in silica gel systems

The effects of temperature and multifunctional sodium carboxylate additives on the phase composition and morphology of calcium oxalate (CaOxa) crystals grown in silica gel system were systematically investigated using scanning electron microscopy (SEM), powder X-ray diffraction (XRD), and Fourier-transform infrared spectra (FT-IR). The sodium carboxylates investigated include: monocarboxylate sodium acetate (NaAc), disodium tartrate (Na2tart), trisodium citrate (Na3cit), and the disodium salt of ethylenediaminetetraacetic acid (Na2edta). The temperature range was from 7°C to 67°C. The crystallization temperature affects the phase compositions, the growth rate, and the morphology of CaOxa. First, the logarithm of the percentage of calcium oxalate dihydrate (COD) formed at a certain temperature (T) is proportional to the reciprocal of temperature (1/T). Second, the weight of CaOxa crystals decreases as decreasing the temperature. At a given temperature, the ability of the sodium carboxylates to induce COD follows the order: Na2edta Na3cit Na2tart NaAc. Third, the multicarboxylates can decrease the surface area of calcium oxalate monohydrate (COM). It makes the edges and tips of COM crystals blunt and oval. All the three changes, an increase of the content of COD, a decrease of the weight of CaOxa crystals, and a decrease of the surface area of COM crystals, can inhibit the formation of CaOxa stones. These results support the clinical use of citrates and may be helpful in elucidating the mechanisms of the formation of CaOxa calculus. Keywords calcium oxalate - sodium carboxylate - gel - urinary calculi - crystallization - biomineralization

Enhancement of solubility and mass transfer coefficient of salicylic acid through hydrotropy

This study deals with the effect of hydrotropes on the solubility and mass transfer coefficient of salicylic acid. The solubility and mass transfer studies were performed using the hydrotropes, i.e., sodium acetate, sodium salicylate, citric acid, and urea at concentrations of 0-3.0 mol/L and system temperatures of 303-333 K. It was found that the solubility and mass transfer coefficient of salicylic acid increases with increase in hydrotrope concentration and also with system temperature. All hydrotropes used in this work showed an enhancement in solubility and mass transfer coefficient to different degrees. The maximum enhancement factor values were determined for all hydrotropes used in this study. The highest value was 28.08 for solubility studies and 10.42 for mass transfer studies. The performance of hydrotropes was measured in terms of the Setschenow constant （Ks）. The highest value observed was 0.696.