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Biomedical subjects

Jayme Diament

Publications and source records attributed to Jayme Diament.

11 recordsLinked to original sources
PubMed2006

Infectious agents, inflammation, and growth factors: how do they interact in the progression or stabilization of mild human atherosclerotic lesions?

Advanced complicated atherosclerotic lesions have been related to many factors, including inflammation, infectious agents, and growth factors. Mycoplasma pneumoniae (MP) and Chlamydia pneumoniae (CP), inflammation, and growth factors have been associated with severe atherosclerotic lesions in necropsy material in recent work at our lab. The present study intends to clarify the pathogenesis of atherosclerosis, analyzing which of these elements (macrophages, MP, CP, lymphocytes, and growth factors) are associated with initial development of atherosclerotic lesions, discriminating elements related to stabilization of the plaque versus those related to subendothelial active accumulation of macrophages in living patients. Surgical ascending aorta fragments presenting mild atherosclerotic lesions from 30 coronary atherosclerotic patients were immunohistochemically quantified regarding CP, MP, T cells (CD4, CD8), B cells (CD20), macrophages (CD68), and growth factors [platelet-derived growth factor A (PDGF-A), PDGF-B, transforming growth factor-beta (TGF-beta), granulocyte-macrophage colony-stimulating factor (GM-CSF)]. Cases were grouped according to the presence or not of active accumulation of macrophages at the subendothelium that indicates atheroma in development: group I (GI) fragments with <4 CD68+ cells/x400 field, in normal distribution (mean 1.8 +/- 1) representing stable atherosclerotic mild lesion, and GII fragments presenting >or=4 CD68+ cells/x400 field, in a non-normal distribution, mean (8.9 +/- 4.8, atheromas in progress), which was followed by increased number of lymphocytes. The median number in GI was significantly lower than that in GII: CD4 T (2.5 vs. 7.7), CD8 T (1.0 vs. 5.5), and CD20 B (1.5 vs. 5.5) cells/x400 field, p < 0.001. Percentage area positive for CP antigens was significantly lower in GI than in GII: 1.0 vs. 9.2, p < 0.001. There was a higher percentage area occupied by MP than CP in both GI and GII (7.8 vs. 13.8). There was no difference regarding mean number of growth factor-positive cells/x400 field: PDGF-A, 1.4 vs. 3.9; PDGF-B, 3.4 vs. 5.7; TGF-beta, 0.9 vs. 2.2; and GM-CSF, 2.0 vs. 2.2. Considering all cases, a positive correlation was seen between inflammatory cells and CP+ cells (r > 0.5 and p < 0.01). Growth factors did not correlate with inflammatory cells, CP, or MP and were usually seen in smooth muscle cell and fibrotic areas. Study of initial atherosclerotic lesions showed that MP is present in both kinds of lesion: stable and active subendothelial accumulation of macrophages. Stabilization was related to proportional increase of both infectious agents, which were also related to increased amount of PDGF-A and PDGF-B. Active macrophage accumulation lesions were related to higher elevation in CP concentration at subendothelial regions, in association with B cells, but not of MP and growth factors. MP and CP, inflammation, and growth factors, which were already described in severe atherosclerotic lesions in necropsy material, are also present in mild lesions in living patients, strongly favoring a pathogenetic role for these bacteria in the pathogenesis of atherosclerosis. Predominance of CP in relation to MP may favor progression of the plaque, which is associated with increased B-cell proliferation. PDGF-A and PDGF-B are associated with plaque stability, at least in arterial segments not prone for development of complicated lesions.

Adult↗
PubMed2006

Metabolic syndrome, abdominal obesity, and cardiovascular risk in elderly women.

BACKGROUND: Metabolic syndrome and abdominal obesity are risk factors for cardiovascular diseases in middle age women but, not completely understood in older people. In this study we analyzed the association between metabolic syndrome and abdominal obesity and the occurrence of cardiovascular events in these elderly women. METHODS: A prospective follow-up study included 516 consecutive women aged 60-84 years who sought medical care at a geriatric outpatient facility. The presence of metabolic syndrome and higher quartiles of waist circumference and waist-to-hip ratio were analyzed as predictive variables, and were adjusted for age, smoking, and previous cardiovascular diseases. The outcomes were the occurrence of stroke, myocardial infarction, evidence of coronary artery disease, or cardiovascular death. RESULTS: During a mean follow-up of 6.6 years, 94 (18.2%) cardiovascular events were observed (48 fatal and 46 non-fatal). Metabolic syndrome was diagnosed in 206 women (39.9%). After adjustments for confounding variables, metabolic syndrome and waist-to-hip ratio above the 75th percentile (>0.98) were predictors of the outcomes, but greater waist circumference (>96 cm) was not. Adjusted hazard ratios for these variables were: metabolic syndrome, 1.66, 95% CI -1.11 to 2.47, p=0.01; waist-to-hip ratio, 1.72, 95% CI -1.05 to 2.82; p=0.03 and waist circumference, 1.37, 95% CI -0.91 to 2.07, p=0.12. CONCLUSION: Metabolic syndrome and high waist-to-hip ratio were associated with increased risk of cardiovascular events in the studied sample.

Abdomen↗
PubMed2006

Co-infection ratios versus inflammation, growth factors and progression of early atheromas.

Mycoplasma pneumoniae (MP) and Chlamydophila pneumoniae (CP) antigens are encountered in complicated atheromas and may be implicated in the diversity of atherosclerotic lesions. Mycoplasma can downregulate the immune system, altering levels of inflammation, which may favor the proliferation of other co-infectious agents. In the present study we analyze whether initially stable human atheromas exhibit different ratios of MP/CP antigens compared to ongoing atheromatous lesions. Two groups were examined for the presence of inflammatory cells, macrophages, growth factors and infectious agents: Group I (GI), n=16, early stable atheromas, <4 CD68(+) macrophages/400 x field, showing a normal distribution and a fibrous cap; Group II (GII), n=14, growing atheromas, > or =4 CD68+ cells/400 x field, lacking a fibrous cap, showing a non-normal macrophage distribution. The amounts of CP (but not MP) antigens and lymphocytes in GI were significantly lower than in GII. MP/CP ratios were higher in GI. MP correlated with CP and PDGFB in GI (r=0.79 and r=0.83, p<0.001), but not in GII (r=-0.4 and r=-0.08, p=0.81). MP and CP antigens are already present in early atheromas, and a higher MP/CP ratio correlates with increased growth factors, lower inflammation and plaque stability.

Adult↗
PubMed2005

[Postprandial lipemia: influence of aging].

OBJECTIVE: To investigate the behavior of postprandial lipemia assessed by means of repeated measurements of triglyceride levels in healthy individuals aged from 20 to 50 years, divided into the following 3 age groups: GI--from 20 to 30 years; GII--from 31 to 40 years; and GIII--from 41 to 50 years. METHODS: Triglyceride levels were measured in 3 conditions: after a 12-hour fast, and 2 and 6 hours after a standard meal containing 40 g of fat. RESULTS: The repeated-measures analysis of triglyceride levels showed a distinct behavior of the age groups throughout the 6 hours. The younger participants (GI) had a reduction in the triglyceride levels in the sixth hour; the elderly (GIII) had increasing values in the sixth hour; and those in the intermediate age group (GII) maintained their triglyceride levels, when comparing the second and sixth hours of blood collection. The differences in behavior were significant (P=0.01). CONCLUSION: In a healthy adult population sample, aging influences the postprandial lipemia behavior.

Adult↗
PubMed2005

[Relationship between body mass index, waist circumference, and waist-to-hip ratio and mortality in elderly women: a 5-year follow-up study].

This study examines the association between body mass index (BMI), waist-to-hip ratio (WHR), and waist circumference (WC) and all-cause and cardiovascular mortality in elderly women in a 5-year longitudinal study of 575 female outpatients 60 years and over. The highest BMI, WHR, and WC quartiles and predefined BMI categories were analyzed as predictive variables. Death occurred in 88 (15.4%). Underweight (BMI < 18.5 kg/m2) was associated with all-cause mortality in uni- and multivariate analyses, regardless of age bracket. The survival curves and univariate analysis showed that the highest WHR quartile (> or = 0.97) was associated with all-cause mortality. However, after adjustment for age, smoking, and previous cardiovascular diseases, the increase in WHR was positively associated only in women from 60 to 80 years of age. None of the anthropometric measurements was associated with cardiovascular mortality. The results indicate that underweight and increased waist-to-hip ratio were predictors of all-cause mortality in elderly women, mainly among those under 80 years.

Aged↗
PubMed2005

Lack of effect of captopril on the metabolism of an artificial lipid emulsion similar to chylomicrons in hypertensive hypercholesterolemic patients.

OBJECTIVE: To assess the effect of captopril, an angiotensin-converting enzyme inhibitor, on the metabolism of chylomicrons and their remnants and the possible alterations in the concentrations of plasma lipids caused by the drug in hypertensive hypercholesterolemic individuals. METHODS: The metabolism of chylomicrons was tested with the method of artificial lipid emulsion of chylomicrons labeled with 3H-cholesteryl oleate. The emulsion was injected intravenously in 10 patients with mild-moderate arterial hypertension before and 45 days after treatment with captopril (50 mg/day). After injection, blood samples were collected during 60 minutes at pre-established time intervals for determining the decay curve, the fractional catabolic rate (FCR in min-1), and the plasma residence time of the artificial lipid emulsion by analyzing different compartments. The plasma concentrations of the lipids were also assessed before and after treatment. RESULTS: The fractional catabolic rate (min-1) of the lipid emulsion before and after treatment with captopril (0.012 +/- 0.003 and 0.011 +/- 0.003, respectively; p = 0.85, n.s.) and the plasma residence time of the emulsion (83.3 +/- 20.8 and 90.9 +/- 22.5 min, n.s.) did not change, but the total cholesterol and LDL-C levels decreased by 7% and 10%, respectively (p = 0.02). The concentrations of HDL-C, triglycerides, Lp(a), and apolipoproteins AI and B did not change. CONCLUSION: Treatment with captopril, evaluated with the artificial lipid emulsion method, does not cause deleterious changes in the metabolism of chylomicrons and their remnants.

Antihypertensive Agents↗
PubMed2002

A method to detect the G894T polymorphism of the NOS3 gene. Clinical validation in familial hypercholesterolemia.

An endothelial nitric oxide synthase gene (NOS3) polymorphism in exon 7 (G894T), resulting in Glu298Asp substitution at protein level, has been associated with myocardial infarction, hypertension and coronary atherosclerosis in some populations. This polymorphism is usually identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). However, the procedures described to date do not eliminate the possibility of misclassification and either require confirmation by DNA sequencing or are time-consuming. In this study, a PCR-RFLP procedure to detect the G894T polymorphism at the NOS3 was optimized by the introduction of a constitutive cleavage site in the amplification product. This cleavage site provides an internal control for enzymatic activity to avoid mistyping. The method was validated by the study of 35 white unrelated individuals with familial hypercholesterolemia and 70 controls. The frequency of the variant allele (T) was similar between both groups (27% vs. 22%, NS), and comparable to the frequency found in other white populations. However, future studies are necessary to confirm these data. In summary, the optimized procedure for detection of the G894T NOS3 polymorphism is rapid, simple, and does not require confirmatory tests. Using this method, we found no association between this polymorphism and familial hypercholesterolemia.

Adolescent↗
PubMedDate not supplied

[Risk factors for atherosclerosis in children and adolescents with family history of premature coronary artery disease].

OBJECTIVES: To identify the prevalence of dyslipidemia in a group of 109 children and adolescents with a family history of premature coronary artery disease and to investigate the association between dyslipidemia and other risk factors for atherosclerosis. METHODS: Total cholesterol, low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), triglycerides, body mass index, blood pressure, physical activity, smoking, per capita income and maternal schooling were investigated. RESULTS: Total cholesterol and LDL-C levels were higher than desirable in 27.5% and 19.3%, respectively, of our patients; 13.8% had lower HDL-C values and 13.0% presented hypertriglyceridemia. Obesity and excess weight were observed in 25.7% of the cases. Out of these, 57.1% had abnormal lipid values. Dyslipidemia was observed in 38.5%, either alone or in combination with other risk factors. Smoking was observed in 3.6%, hypertension in 2.7% and physical inactivity in 72.5%. There was no relationship between dyslipidemia and per capita income, maternal schooling and physical inactivity. However, obesity and excess weight were identified as significantly associated with the occurrence of dyslipidemia (p = 0.02; odds ratio = 2.82, 95% CI = 1.6-6.81). CONCLUSION: In children and adolescents with a family history of premature coronary artery disease, early identification of the risk factors for atherosclerosis is essential to allow the implementation of preventive measures.

Adolescent↗