糖尿病大鼠性腺及外周血中性激素的改变

目的:研究糖尿病大鼠性腺及外周血中性激素的变化。方法:用放射免疫法检测糖尿病(DM)大鼠,正常(NDM)大鼠和STZ大鼠血清性激素含量,同时称取性腺重量,镜检睾丸、前列腺及附睾的组织形态学改变。结果:DM组睾酮水平显著低于NDM组、STZ组(P<0.01);NDM组与STZ组之间,睾酮水平无显著性差异;DM组促黄体生成素(LH)水平显著高于NDM组、STZ组(P<0.01);NDM组与STZ组之间。LH水平无显著性差异;促卵泡刺激素(FSH)水平在各组之间无显著性差异;HE结果显示,DM组性腺显微结构较NDM组及STZ组明显改变。结论:提示DM严重影响大鼠性腺功能及睾酮的合成分泌,并显著降低大鼠血清睾酮含量。     

2型糖尿病患者乙型肝炎病毒感染率分析

目的：通过调查糖尿病患者乙型肝炎病毒（HBV）的携带率,阐明糖尿病发生是否与HBV感染有关,并观察糖尿病合并HBV感染时是否加重对肝功能的损害。方法：用ELISA方法检测533例2型糖糖尿病患者和1440例普通人群乙型肝炎表面抗原（HBsAg）以及HBV其他血清学标志,同时常规测定肝功能和血糖等。结果：2型糖尿病HBsAg阳性24例,阳性率4.50%,普通人群HBsAg阳性70例,阳性率4.86%,两组间阳性率差异无统计学意义（x2=0.110,P=0.740）。糖尿病患者感染HBV后的抗体应答与普通人群相似。糖尿病合并HBV感染者与无糖尿病HBV感染者的肝功能异常差异无统计学意义。糖尿病患者中83例（16.3%）谷氨酰转肽酶升高,在肝功能异常指标中最常见,这与HBV感染后丙氨酸转氨酶升高为主不同。结论：糖尿病发生与HBV感染无关,糖尿病合并HBV感染时不加重对肝脏的损害。     

Increased tissue kallikrein amidase activity in urine of patients with type 1 diabetes under insulin therapy, and in those with gestational diabetes mellitus not under insulin therapy

Human tissue kallikrein (hK1) is reduced in hypertension, cardiovascular and renal diseases. There is little information on the participation of hK1 in type 1 diabetes mellitus (DM), type 2 DM, and gestational diabetes mellitus (GDM), respectively. The aim of this study was to evaluate the roles of insulin and hyperglycemia on urinary hK1 activity in type 1 DM and in GDM. Forty-three type 1 DM patients (5–35 years, disease duration ?5 years, receiving insulin, HbA_1c > 7.6%) were selected. Forty-three healthy individuals, paired according to gender and age, were used as controls. Thirty GDM patients (18–42 years, between the 24th and 37th week of pregnancy, recently diagnosed, not under insulin therapy) were also selected. Thirty healthy pregnant (18–42 years, between the 24th and 37th week of pregnancy) and 30 healthy non-pregnant women (18–42 years) were selected as controls. Random midstream urine was used. hK1 amidase activity was estimated with D-Val-Leu-Arg-Nan substrate. Creatinine was determined by Jaffe’s method. hK1 specific amidase activity was expressed as μM/(min mg creatinine) to correct for differences in urine flow rate. hK1 specific amidase activity was significantly higher in the urine of type 1 DM than in controls, and in the urine of GDM patients than in healthy pregnant women and healthy non-pregnant women, respectively. The data suggest that hyperglycemia, rather than insulin, is involved in the mechanism of increased hK1 specific amidase activity in both type 1 DM and GDM patients, respectively.     

Markers of enhanced cholesterol absorption are a strong predictor for cardiovascular diseases in patients without diabetes mellitus

Objective

Hypercholesterolemia is a major risk factor for cardiovascular disease (CVD), and diabetes mellitus and statin treatment affect cholesterol metabolism. The aim of the present study was to evaluate markers of cholesterol metabolism and determine their relationship with CVD in patients without diabetes mellitus who were not receiving statin treatment.

Methods

In addition to conventional CVD risk factors, plasma levels of campesterol and sitosterol (indicators of cholesterol absorption) and lathosterol (an indicator of cholesterol synthesis) were determined in 835 consecutive patients referred for coronary angiography. Coronary artery disease was evaluated by coronary angiograms, carotid atherosclerosis and peripheral vascular disease were assessed by Doppler ultrasound, and cerebrovascular accidents and transient ischemic attacks were identified by medical history.

Results

After excluding patients with known diabetes mellitus and those receiving statin treatment, 177 patients were included in the analysis. Compared to patients without CVDs (n = 111), patients with concomitant CVDs (n = 66) had a reduced lathosterol-to-cholesterol ratio (1.25 ± 0.61 vs. 1.38 ± 0.63, P < 0.05) and an increased campesterol-to-cholesterol ratio (1.81 ± 1.04 vs. 1.50 ± 0.69, P < 0.05), indicating that enhanced absorption and reduced synthesis of cholesterol is associated with CVD development. Logistic regression analysis including all established cardiovascular risk factors (age, sex, total cholesterol, arterial hypertension, body mass index and smoking) revealed that campesterol and the campesterol-to-cholesterol ratio were significant predictors of concomitant CVD in this patient population.

Conclusion

In patients without diabetes mellitus, markers of enhanced cholesterol absorption were a strong predictor for concomitant CVD.     

Stimulated release of calcitonin gene-related peptide from the human right atrium in patients with and without diabetes mellitus

Calcitonin gene-related peptide (CGRP), a potent vasodilator released during activation from a subset of sensory Aδ- and C-fiber afferents, has been suggested to play a beneficial role in myocardial ischemia. Variations in CGRP release can possibly be correlated with diseases that involve changes in activity or degeneration of cardiac afferent fibers. The aim of the present study was to examine basal and stimulated CGRP release from cardiac tissue in patients who underwent cardiopulmonary bypass surgery and to compare patients with and without known history of diabetes mellitus. Small pieces of the right atrium routinely excised during the bypass operations were passed through series of oxygenated solutions. The TRPV1 receptor agonist capsaicin and the nitric oxide donor NONOate were added for stimulation of cardiac afferent fibers. The eluates were processed using an enzyme immuno-assay (EIA) for measurement of CGRP concentrations. Both capsaicin and NONOate caused significant increases in CGRP release. No significant differences in CGRP release between patients with and without diabetes mellitus were examined. The present study evaluates a simple and reproducible model for measuring stimulated CGRP release from the human right atrium.     

Angiotensin II,as well as 5-hydroxytriptamine,is a potent vasospasm inducer of saphenous vein graft for coronary artery bypass grafting in patients with diabetes mellitus

Diabetes mellitus (DM) is an important risk factor for adverse outcomes of coronary artery bypass grafting. The bypass grafts harvested from patients with DM tend to go into spasm after their implantation into the coronary circulation. To clarify the contribution of 5-hydroxytriptamine (5-HT) and angiotensin II (AngII) in the bypass graft spasm, we examined the contractile reactivity to 5-HT or AngII of isolated human endothelium-denuded saphenous vein (SV) harvested from DM and non-DM patients. The 5-HT-induced constriction of the SV was significantly augmented in the DM group than in the non-DM group, which is similar to our previous report. AngII-induced constriction of the SV was also significantly augmented in the DM group than the non-DM group. Especially in the non-DM group, the AngII-induced maximal vasoconstriction was markedly lower than the 5-HT-induced one. Meanwhile, the increasing rates of AngII-induced vasoconstriction in the DM group to the non-DM group were significantly greater than those of 5-HT-induced vasoconstriction. These results indicate that 5-HT is a potent inducer of SV graft spasm in both DM and non-DM patients, while AngII is a potent inducer of SV graft spasm only in patients with DM. Furthermore, the protein level of AngII AT₁ receptor (AT₁R), but not the protein level of 5-HT_2A receptor, in the membrane fraction of the SV smooth muscle cells of DM patients was significantly increased as compared with that of the non-DM patients. These results suggest that the mechanism for hyperreactivity to AngII in the SV from DM patients is due to, at least in part, the increase in the amount of AT₁R on membrane of the SV smooth muscle cells.     

In vitro effect of gliclazide on DNA damage and repair in patients with type 2 diabetes mellitus (T2DM)

Type 2 diabetes mellitus is associated with elevated level of oxidative stress, which is one of the most important factors responsible for the development of chronic complications of this disease. Moreover, it was shown that diabetic patients had increased level of oxidative DNA damage and decreased effectiveness of DNA repair. These changes may be associated with increased risk of cancer in T2DM patients, since DNA damage and DNA repair play a pivotal role in malignant transformation. It was found that gliclazide, an oral hypoglycemic drug with antioxidant properties, diminished DNA damage induced by free radicals. Therefore, the aim of the present study was to evaluate the in vitro impact of gliclazide on: (i) endogenous basal and oxidative DNA damage, (ii) DNA damage induced by hydrogen peroxide and (iii) the efficacy of DNA repair of such damage. DNA damage and DNA repair in peripheral blood lymphocytes of 30 T2DM patients and 30 non-diabetic individuals were evaluated by alkaline single cell electrophoresis (comet) assay. The extent of oxidative DNA damage was assessed by DNA repair enzymes: endonuclease III and formamidopyrimidine-DNA glycosylase. The endogenous basal and oxidative DNA damages were higher in lymphocytes of T2DM patients compared to non-diabetic subjects and gliclazide decreased the level of such damage. The drug significantly decreased the level of DNA damage induced by hydrogen peroxide in both groups. Gliclazide increased the effectiveness of DNA repair in lymphocytes of T2DM patients (93.4% (with gliclazide) vs 79.9% (without gliclazide); P< or =0.001) and non-diabetic subjects (95.1% (with gliclazide) vs 90.5% (without gliclazide); P< or =0.001). These results suggest that gliclazide may protect against the oxidative stress-related chronic diabetes complications, including cancer, by decreasing the level of DNA damage induced by reactive oxygen species.     

The defective protein level of myosin light chain phosphatase (MLCP) in the isolated saphenous vein, as a vascular conduit in coronary artery bypass grafting (CABG), harvested from patients with diabetes mellitus (DM)

We examined the contractile reactivity to 5-hydroxytryptamine (5-HT) in isolated human saphenous vein (SV), as a vascular conduit in coronary artery bypass grafting (CABG), harvested from patients with diabetes mellitus (DM) and non-DM (NDM). Vascular rings of endothelium-denuded SV were used for functional and biochemical experiments. The vasoconstrictions caused by 5-HT were significantly greater (hyperreactivity) in the DM group than in the NDM group. RhoA/ROCK pathway is activated by various G-protein-coupled receptor agonists and consequently induces phosphorylation of myosin phosphatase target subunit 1 (MYPT1), a subunit of myosin light chain phosphatase (MLCP), which inhibits MLCP activity. In the resting state of the vessels, total tissue protein levels of 5-HT_2A receptor, 5-HT_1B receptor, RhoA, ROCK1, and ROCK2 did not differ between NDM and DM groups. However, the total protein level of MYPT1 was significantly lower in the DM group than in the NDM group. Furthermore, the ratio of P(Thr⁶⁹⁶)-MYPT1 to total MYPT1 was significantly higher in the DM group than in the NDM group. These results suggest that the hyperreactivity to 5-HT in the SV smooth muscle of patients with DM is due to not only enhanced phosphorylation of MLCP but also defective protein level of MLCP. Thus, we reveal for the first time that the defective protein level of MLCP in the DM group can partially explain the poor patency of SV graft harvested from patients with DM.     

SMART Digest™ compared with pellet digestion for analysis of human immunoglobulin G1 in rat serum by liquid chromatography tandem mass spectrometry

The newly developed SMART Digest™ kit was applied for the sample preparation of human immunoglobulin G1 (hIgG1) in rat serum prior to qualitative and quantitative analyses by liquid chromatography tandem mass spectrometry (LC–MS/MS). The sequence coverages obtained for the light and heavy chains of hIgG1A were 50 and 76%, respectively. The calibration curve was linear from 1.00 to 1000 μg/ml for three of four generic peptides. Overall, the SMART Digest™ kit resulted in similar quantitative data (linearity, sensitivity, accuracy, and precision) compared with the pellet digestion protocol. However, the SMART Digest™ required only 2 h of sample preparation with fewer reagents.     

Association of RAGE gene polymorphism with circulating AGEs level and paraoxonase activity in relation to macro-vascular complications in Indian type 2 diabetes mellitus patients

Background and aims

Sustained interaction of advanced glycation end products (AGEs) with their receptor RAGE and subsequent signaling plays an important role in the development of diabetic complications. Genetic variation of RAGE gene may be associated with the development of vascular complications in type 2 diabetes mellitus (T2DM).

Objectives

The present study aimed to explore the possible association of RAGE gene polymorphisms namely − 374T/A, − 429T/C and G82S with serum level of AGEs, paraoxonase (PON1) activity and macro-vascular complications (MVC) in Indian type 2 diabetes mellitus patients (T2DM).

Methods

A total of 265 diabetic patients, including DM without any complications (n = 135), DM-MVC (n = 130) and 171 healthy individuals were enrolled. Genotyping of RAGE variants were assessed by polymerase chain reaction-restriction fragment length polymorphism. Serum AGEs were estimated by ELISA and fluorometrically. and PON1 activity was assessed spectrophotometrically.

Results

Of the three examined SNPs, association of − 429T/C polymorphism with MVC in T2DM was observed (OR = 3.001, p = 0.001) in the dominant model. Allele ‘A’ of − 374T/A polymorphism seems to confer better cardiac outcome in T2DM. Patients carrying C allele (− 429T/C) and S allele (G82S) had significantly higher AGEs levels. − 429T/C polymorphism was also found to be associated with low PON1 activity. Interaction analysis revealed that the risk of development of MVC was higher in T2DM patients carrying both a CC genotype of − 429T/C polymorphism and a higher level of AGEs (OR = 1.343, p = 0.040).

Conclusion

RAGE gene polymorphism has a significant effect on AGEs level and PON1 activity in diabetic subjects compared to healthy individuals. Diabetic patients with a CC genotype of − 429T/C are prone to develop MVC, more so if AGEs levels are high and PON1 activity is low.     

Analysis of serum heat shock protein 70 (HSPA1A) concentrations for diagnosis and disease activity monitoring in patients with rheumatoid arthritis

Heat shock proteins (HSPs) have been repeatedly implicated in the pathogenesis of rheumatoid arthritis (RA). The authors aimed to study applicability of heat shock protein 70 (HSPA1A) serum levels as a diagnostic factor and a severity indicator in patients with RA and to quantify cut-off point that predicts status of RA with highest specificity. A total of 76 patients with RA and 36 healthy adults were studied in this case-control analysis. Patients had a higher HSPA1A level than the control group (0.78 ± 0.13 vs. 0.12 ± 0.02 ng/mL, p = 0.006), irrespective of presence of absence of rheumatoid factor or anti-citrullinated cyclic peptide. Next, diagnostic accuracy of the HSPA1A in diagnosis of RA was evaluated (area under curve 0.71; p < 0.05). HSPA1A predicted status of having RA in levels above 0.42 ng/mL with more than 90 % specificity. In addition to diagnostic value, HSPA1A can distinguish between high disease activity (1.66 ± 0.75 ng/mL) and low (0.49 ± 0.1 ng/mL), moderate (0.52 ± 0.12 ng/mL), or remission phase (0.48 ± 0.11 ng/mL). Moreover, patients in remission still had a higher HSPA1A level compared to normal subject (0.48 ± 0.11 vs. 0.12 ± 0.02 ng/mL, p < 0.05). Our results showed that serum HSPA1A could be implemented as a specific tool to facilitate diagnosis and monitoring disease activity in patients with rheumatoid arthritis.

Electronic supplementary material

The online version of this article (doi:10.1007/s12192-015-0578-z) contains supplementary material, which is available to authorized users.