Collagen fibers in the rectus abdominis muscle of cadavers of different age.

PURPOSE: To assess collagen content and types in the rectus abdominis muscle of cadavers of different ages. METHODS: Forty fresh adult male cadavers within 24 h of death were obtained from an Institute of Legal Medicine and divided by age at death into Group 1 (mean age, 23.3 years; range, 18-30 years; n = 20) and Group 2 (mean age, 46.2 years; range, 31-60 years; n = 20). From each cadaver, samples of the rectus abdominis muscle measuring 1 cm(2) were collected 3 cm superiorly and 2 cm inferiorly to the umbilicus. Histological sections were prepared and stained with picrosirius red and Masson's trichrome stain for visualization of total collagen fibers, and immunohistochemical analysis was performed to distinguish types I, II, III, IV and V collagen. RESULTS: No significant differences in total collagen were found between groups by Masson's trichrome staining. However, picrosirius red staining revealed a significantly greater amount and higher concentration of total collagen and types I and III collagen in Group 1 than in Group 2 (P < 0.05). All but type II collagen were detected by immunohistochemistry in both groups. No significant difference in type IV collagen was found between groups. Type V collagen was detected by immunohistochemistry in both groups, but quantification was not possible due to background staining. CONCLUSION: The amounts of types I and III collagen in the rectus abdominis muscle were significantly smaller in older subjects.

Insulin resistance is associated with DNA damage in peripheral blood cells in non-diabetic patients with genotype 1 chronic hepatitis C.

BACKGROUND: In chronic liver diseases of different etiologies, including viral hepatitis, genotoxic effects of oxidative stress have been shown, both in clinical and in experimental conditions, suggesting that this mechanism may contribute to the evolution of the disease. AIM: To evaluate DNA damage in the peripheral blood of untreated non-diabetic patients with chronic hepatitis C and control subjects, and its correlation with demographic, anthropometric, biochemical, and histological parameters in the patient sample. PATIENTS AND METHODS: This study comprised 100 subjects of both genders, 60 of whom were treatment-naïve patients with positive serology for genotype 1 hepatitis C. The remaining 40 were blood donors with negative serology for hepatitis who were used as control subjects, and matched by gender, age, weight, and BMI. DNA damage was determined using the comet assay in the total peripheral blood. RESULTS: The DNA damage evaluated by the comet assay revealed higher values in the group of patients with hepatitis compared with that in the control group. The relationships of the comet assay with the studied variables were assessed using multivariate analysis; significant correlations were only identified with insulin (r = 0.343, p = 0.008) and Homeostasis Model Assessment Insulin Resistance (HOMA-IR) (r = 0.331, p = 0.011). CONCLUSION: Patients with genotype 1 chronic hepatitis C have higher rates of DNA damage, as determined by comet assay and this alteration is correlated with the HOMA index of insulin resistance.

Relationship between gene polymorphisms and prevalence of myocardial infarction among diabetic and non-diabetic subjects.

This study was aimed to examine cholesteryl ester transfer protein (CETP), apolipoprotein AI and CIII gene polymorphisms, and to verify whether these genetic determinants are associated with the prevalence of myocardial infarction (MI) or type 2 diabetes. The TaqIB restriction fragment length polymorphism (RFLP) in intron I of the CETP gene, the MspI in the third intron of the APOAI gene, and also SstI in the 3' untranslated region of the APOCIII gene were determined using standard methods. The prevalence of these polymorphisms was compared between diabetic (n = 119), and non-diabetic (n = 100) middle-aged individuals of both sexes. We found a higher prevalence of the B2B2 genotype of the CETP gene among diabetics than that observed in non-diabetics (P < 0.05), and a lower prevalence of this genotype among patients with previous MI (P < 0.02). The MspI polymorphisms of the APOAI gene showed that M1++ genotype was found mainly in diabetic patients (P < 0.04). Conversely, the SstI polymorphism of APOCIII gene was not significantly associated with either MI or diabetes. Therefore, among these genetic polymorphisms, TaqIB of CETP and MspI of apolipoprotein AI appeared to help significantly to identify diabetic individuals. In particular, the former may have an additional role in the primary prevention of coronary disease.

Hydrochlorothiazide abolishes the anti-atherosclerotic effect of quinapril.

1. Antihypertensive treatment has been demonstrated to result in persistent reductions in morbidity and mortality due to stroke. However, the coronary risk attributable to hypertension has been only partially reversed. We hypothesized that diuretics could have unfavourable effects on atherosclerosis. 2. New Zealand rabbits were fed a 0.5% cholesterol-enriched diet for 12 weeks, followed by a 0.1% cholesterol diet for another 12 weeks. During the last 12 week period, 40 animals were randomly assigned to one of four groups: (i) group I was the control group; (ii) group II received hydrochlorothiazide (10 mg/day); (iii) group III received quinapril (30 mg/day); and (iv) group IV was treated with hydrochlorothiazide (10 mg/day) plus quinapril (30 mg/day). 3. The treatments did not affect either the lipid profile or serum electrolytes and oxidative stress. However, endothelium-dependent vasorelaxation in isolated aortic rings was significantly improved with quinapril (group III) treatment (P < 0.001 vs other groups). In addition, therapy with quinapril promoted a significant reduction in atherosclerosis (intima area, intima/media ratio and perimeter of vessel with plaque; P < 0.05 vs other groups), as well as in cholesterol content of the aorta (P < 0.05 vs groups II and IV). 4. In conclusion, hydrochlorothiazide did not modify atherosclerosis and, when added to quinapril treatment, impaired the anti-atherosclerotic effect seen with quinapril alone.

Role of smooth muscle cell membrane potential in neointima formation in arteries of spontaneously hypertensive rats.

Based on observations that vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) have altered resting potentials as well as abnormal cell proliferation rates, neointima formation after controlled balloon injury was compared in arteries from SHR and Wistar Kyoto rats (WKY). SHR aortic VSMC showed hyperpolarized resting membrane potentials (-93+/-8 mV) when compared to those from WKY (-61+/-6 mV). Histomorphometric analysis of cross sections from aortic segments submitted to balloon injury showed reduced neointima formation in SHR (neointima/media ratio: 0.04+/-0.03) as compared to WKY (0.2+/-0.1). On the other hand, in injured carotid arteries, neointima formation was more extensive in SHR (neointima/media ratio 5.0+/-0.9) than in WKY (0.8+/-0.7), leading in most cases to luminal occlusion. Measurements of VSMC resting potential showed that carotid artery cells from SHR were depolarized with respect to those from WKY (-46+/-4 vs. -69+/-5 mV, respectively). The results demonstrate an inverse relationship between VSMC membrane polarization and neointima formation in SHR arteries, suggesting that genetic modifications in SHR determine a dysfunctional cellular physiology that may influence cell proliferation subsequent to injury.

Abnormal proliferative response of the carotid artery of spontaneously hypertensive rats after angioplasty may be related to the depolarized state of its smooth muscle cells

Hypertension is one of the major precursors of atherosclerotic vascular disease, and vascular smooth muscle abnormal cell replication is a key feature of plaque formation. The present study was conducted to examine the relationship between hypertension and smooth muscle cell proliferation after balloon injury and to correlate neointima formation with resting membrane potential of uninjured smooth muscle cells, since it has been suggested that altered vascular function in hypertension may be related to the resetting of the resting membrane potential in spontaneously hypertensive rats (SHR). Neointima formation was induced by balloon injury to the carotid arteries of SHR and renovascular hypertensive rats (1K-1C), as well as in their normotensive controls, i.e., Wistar Kyoto (WKY) and normal Wistar (NWR) rats. After 14 days the animals were killed and the carotid arteries were submitted to histomorphometric and immunohistochemical analyses. Resting membrane potential measurements showed that uninjured carotid arteries from SHR smooth muscle cells were significantly depolarized (-46.5 + or - 1.9 mV) compared to NWR (-69 + or - 1.4 mV), NWR 1K-1C (-60.8 + or - 1.6 mV), WKY (-67.1 + or - 3.2 mV) and WKY 1K-1C (-56.9 + or - 1.2 mV). The SHR arteries responded to balloon injury with an enhanced neointima formation (neo/media = 3.97 + or - 0.86) when compared to arteries of all the other groups (NWR 0.93 + or - 0.65, NWR 1K-1C 1.24 + or - 0.45, WKY 1.22 + or - 0.32, WKY 1K-1C 1.15 + or - 0.74). Our results indicate that the increased fibroproliferative response observed in SHR is not related to the hypertensive state but could be associated with the resetting of the carotid smooth muscle cell resting membrane potential to a more depolarized state