Colloidal copper oxide nanoparticles leading to a biphasic dose-response in growth inhibition of Staphylococcus aureus

Aim: The dose response in growth inhibition of Staphylococcus aureus treated with colloidal copper oxide nanoparticles (CuO-NP) was evaluated. Methods: An in vitro microbial viability assay was conducted with CuO-NP concentrations spreading over the 0.4-848.0 μg/ml range. The dose-response curve was modeled with a double Hill equation. UV-Visible absorption and photoluminescence spectroscopies allowed tracking concentration-dependent modifications in CuO-NP. Results: Two specific phases separated by the critical concentration of 26.5 μg/ml were observed in the dose-response curve, with each exhibiting proper IC₅₀ parameters, Hill coefficients, and relative amplitudes. Spectroscopy techniques reveal the occurrence of a concentration-triggered aggregation of CuO-NP starting from this critical concentration. Conclusion: The findings demonstrate a dose-related change in S. aureus sensitivity to CuO-NP, which probably arises from the aggregation of this agent.

Copaiba oil and Neem extract can be a potential alternative for the behavioral control of Sitophilus zeamais

Insects' ethology is an important factor when it is desired to carry out pest management. This knowledge makes it possible to manipulate behavioral activities, repel, or attract insects according to needs and interests. The maize weevil Sitophilus zeamais (Mots., 1855) (Coleoptera: Curculionidae), one of the main stored grain pests, has been the target of studies of behavioral changes studies through natural substances due to its resistance to different insecticidal classes. Thus, this study aimed to evaluate the effect of sublethal concentrations of neem extract and copaiba oil on the locomotor behavior of S. zeamais. The behavioral characteristic considered were walking activity, the frequency of contact of insects with the treated grain mass, and the time spent for this behavior. The walking activity of the S. zeamais increased with exposure to Neem extract and Copaiba oil. In general, the Neem extract and Copaiba oil-induced more contact with grain mass than the control, suggesting an attractive effect on the insect, however more significant for the Neem oil. The insect's behavior was altered, presenting a specific path due to Copaiba oil and Neem extract stimuli. These results indicate that Copaiba oil and Neem extract can be a potential alternative for controlling S. zeamais on stored products since changes in this pests' behavior can reduce qualitative and quantitative grain damage. Thus, the development of products based on Copaiba oil and Neem extract may be helpful for storage pest management.

Association of Increased Levels of Homocysteine and Peripheral Arterial Disease in a Japanese-Brazilian Population

OBJECTIVES

Our aim was to evaluate the possible association between homocysteine levels and peripheral arterial disease (PAD) in a population-based study of Japanese-Brazilians.

MATERIALS AND METHODS

This cross-sectional study was derived from a population-based survey on the prevalence of diabetes and associated diseases conducted in Japanese-Brazilians. A total of 1330 male and female subjects aged>or=30 years were submitted to clinical examination and laboratory procedures including homocysteine measurement. The ankle-brachial index (ABI) was calculated; subjects with ABI values <0.9 were diagnosed with PAD. The evaluable population included 1008 subjects. Logistic regression was used taking PAD as the dependent variable.

RESULTS

Mean age of the population was 56.5 years and overall prevalence of PAD was 20%. A worse cardiovascular profile was found in male patients, including significantly higher homocysteine levels (11.9+/-1.8 vs. 9.1+/-1.1micromol/L, p<0.001). Men with PAD had higher prevalence rates of hyperhomocysteinemia compared to women (22.7% vs 7.6%). Univariate analysis showed an odds ratio of hyperhomocysteinemia for PAD of 1.51 [1.02-2.25] in men and 1.69 [1.06-2.68] in women. After adjustment for other cardiovascular risk factors, higher levels of homocysteine were only significantly related to PAD in men.

CONCLUSION

In a Japanese-Brazilian population, elevated levels of homocysteine are associated with PAD in men. Prospective studies are necessary to confirm this finding.

[Social representation and its contributions to the health area]

This article approaches, in theory, a notion of Social Representations, describing its origin, concepts, fields of study and manners of approach, which are: dimensional, structural and dynamic. Some comments about the use of this framework in the health area are made, as well as how can it be used in Nursing.

Metabolic and haemodynamic effects of metformin in patients with type 2 diabetes mellitus and hypertension

BACKGROUND

Since metformin improves insulin sensitivity, it has been indicated for patients with diabetes and hypertension, which are insulin-resistant conditions. In contrast to its well-known effects on carbohydrate metabolism, its potential for reducing blood pressure (BP) and its effect on leptin levels have been investigated less frequently.

PATIENTS AND METHODS

A double-blind, randomized, placebo-controlled trial was carried out with 26 overweight diabetic subjects with mild-to-moderate hypertension to assess the effects of metformin-induced glycaemic control on BP and metabolic parameters. After a 4-week placebo period, when BP was stabilized by calcium channel blockers, they received either metformin (MG) or placebo (PG) for 12 weeks.

RESULTS

Neither group showed any change in weight throughout the study. Only metformin-treated patients reduced fasting plasma glucose (8.54 + 1.72 to 7.54 + 1.33 mmol/l, p < 0.05), although HbA(1c) had decreased in both groups (PG: 6.7+/-3.0 to 5.9+/-2.6%; MG: 5.3+/-1.5 to 4.6+/-0.9%; p < 0.05). The initial office mean BPs were similar and decreased at the end of the treatment period in both groups, reaching statistical significance only in MG (105.7+/-8.0 to 99.2+/-9.3 mmHg, p < 0.05). No difference was observed when comparing baseline and final values obtained by 24-h ambulatory BP monitoring. Metformin induced a reduction in both insulinaemia (71.0+/-62.4 to 38.0+/-23.0 pmol/l, p < 0.05) and the insulin resistance index (3.5+/-2.7 to 1.8+/-1.0, p < 0.05). The two groups had similar baseline leptin levels which remained unchanged after treatment (PG: 16.8+/-7.9 to 21.4+/-14.6 microg/l; MG: 18.5+/-10.3 to 18.4+/-8.9 microg/l). Dopamine levels increased significantly only in metformin-treated subjects.

CONCLUSIONS

Reductions in both the insulin levels and the resistance index reinforced metformin capacity to improve peripheral sensitivity. Moreover, such benefits were not accompanied by any hypotensive effects. Since leptin levels were affected neither by metformin per se nor by the induced insulinaemia reduction, our data support the role of body weight as the major determinant of circulating leptin levels.

Ultrasonography for the evaluation of visceral fat and cardiovascular risk

Visceral fat accumulation is associated with increased cardiovascular risk. Clinical evaluation of visceral fat is limited because of the lack of reliable and low-cost methods. To assess the correlation between ultrasonography and computed tomography (CT) for the evaluation of visceral fat, 101 obese women, age 50.5+/-7.7 years with a body mass index of 39.2+/-5.4 kg/m(2), were submitted to ultrasonograph and CT scans. Visceral fat measured by ultrasonography, 1 cm above the umbilical knot, showed a high correlation with CT-determined visceral fat (r=0.67, P<0.0001). The ultrasonograph method showed good reproducibility with an intra-observer variation coefficient of <2%. Both ultrasonograph and CT visceral fat values were correlated with fasting insulin (r=0.29 and r=0.27, P<0.01) and plasma glucose 2 hours after oral glucose load (r=0.22 and r=0.34, P<0.05), indicating that ultrasonography is a useful method to evaluate cardiovascular risk. A significant correlation was also found between visceral fat by CT and serum sodium (r=0.18, P<0.05). A ultrasonograph-determined visceral-to-subcutaneous fat ratio of 2.50 was established as a cutoff value to define patients with abdominal visceral obesity. This value also identified patients with higher levels of plasma glucose, serum insulin and triglycerides and lower levels of HDL-cholesterol, which are metabolic abnormalities characteristic of the metabolic syndrome. Our data demonstrate that ultrasonography is a precise and reliable method for evaluation of visceral fat and identification of patients with adverse metabolic profile.

Influence of dexamethasone and weight loss on the regulation of serum leptin levels in obese individuals

The adipocyte hormone leptin is thought to serve as a signal to the central nervous system reflecting the status of fat stores. Serum leptin levels and adipocyte leptin messenger RNA levels are clearly increased in obesity. Nevertheless, the factors regulating leptin production are not fully understood. The aim of this study was to determine the effects of in vivo administration of the synthetic glucocorticoid dexamethasone and weight loss on serum leptin levels in two independent protocols. Twenty-five obese subjects were studied (18 women and 7 men, mean age 26.6 +/- 6 years, BMI 31.1 +/- 2.5 kg/m(2), %fat 40.3 +/- 8.3) and compared at baseline to 22 healthy individuals. Serum levels of leptin, insulin, proinsulin and glucose were assessed at baseline and after ingestion of dexamethasone, 4 mg per day (2 mg, twice daily) for two consecutive days. To study the effects of weight loss on serum leptin, 17 of the obese subjects were submitted to a low-calorie dietary intervention trial for 8 weeks and again blood samples were collected. Serum leptin levels were significantly higher in the obese group compared to the control group and a high positive correlation between leptinemia and the magnitude of fat mass was found (r = 0.88, P<0.0001). After dexamethasone, there was a significant increase in serum leptin levels (22.9 +/- 12.3 vs 51.4 +/- 23.3 ng/ml, P<0.05). Weight loss (86.1 +/- 15.1 vs 80.6 +/- 14.2 kg, P<0.05) led to a reduction in leptin levels (25.13 +/- 12.8 vs 15.9 +/- 9.1 ng/ml, P<0.05). We conclude that serum leptin levels are primordially dependent on fat mass magnitude. Glucocorticoids at supraphysiologic levels are potent secretagogues of leptin in obese subjects and a mild fat mass reduction leads to a disproportionate decrease in serum leptin levels. This suggests that, in addition to the changes in fat mass, complex nutritional and hormonal interactions may also play an important role in the regulation of leptin levels.

Effect of blood glucose on left ventricular mass in patients with hypertension and type 2 diabetes mellitus

The aim of our prospective study was to evaluate the influence of blood glucose (BG) on left ventricular mass and diastolic function in patients with hypertension and type 2 diabetes mellitus (DM). Fifty-six hypertensive patients with type 2 DM and 26 healthy controls were investigated. They were submitted to echocardiography (ECHO) with Doppler and we calculated the mean of their fasting BG values, office blood pressure (OBP), cholesterol and fractions, and triglycerides during the previous 4 years. The diabetic patients were then followed-up for 1 year with OBP, fasting BG, and lipids measured every 2 months. After this period, the patients were again submitted to ECHO and in 22 patients (group I [GI]), reductions greater than 10% in left ventricular mass index (LVMI) were observed (122 +/- 35 v 89 +/- 23 g/m2, P < .01), whereas increases greater than 10% (group II [GII], n = 17) (94 +/- 18 v 115 +/- 27 g/m2, P < .01) or no changes (group III [GIII], n = 17) (98 +/- 16 v 99 +/- 18 g/m2, NS) in LVMI were detected in the remaining patients. The OBP values did not change during the follow-up. In GI the reduction of LVMI was associated with a BG fall from 178 +/- 36 to 147 +/- 30 mg/dL (P < .01) and a correlation was observed between BG and LVMI percent variations (delta) (r = 0.48, P < .01). No important changes in left ventricular diastolic function were observed during the follow-up. We concluded that the improvement in glycemic control may contribute to LVH regression in hypertensive patients with type 2 DM.

Dietary patterns in a high-risk population for glucose intolerance. Japanese-Brazilian Diabetes Study Group

We evaluated dietary habits as risk factor for glucose intolerance in a high risk population of Japanese-Brazilians enrolled in a study on the prevalence of diabetes (DM). Based on oral glucose tolerance test and WHO criteria, 331 had normal tolerance (NGT), 88 impaired tolerance (IGT) and 83 had type 2 DM (51 self-reported, 32 newly diagnosed diabetics). Clinical, laboratory and dietary data, assessed by food frequency questionnaire (FFQ), were compared between the NGT group and another composed of IGT and newly diagnosed DM (disturbed glucose tolerance or DGT group). Associations of total energy intake and nutrient intakes with glucose intolerance were analyzed by logistic regression. Also, subjects with NGT and DGT entered into separate models of multiple linear regression including BMI as the dependent variable, and total energy intake or each nutrient as independent variables. DGT group showed higher waist-to-hip ratio, blood pressure, plasma glucose and insulin levels and worse lipid profile. Total energy intake, macronutrients, fibers, alcohol and saturated fat intakes did not differ between groups; DGT was not associated with any nutrient intake in multivariate analyses. BMI of the subjects with DGT but not with NGT was associated with protein and cholesterol intakes in linear regression analysis. Our findings did not support an association between nutritional factors and glucose intolerance even in subjects who are unaware of their DGT, using FFQ to reflect current habits. However, we suggest that protein and cholesterol intakes may be markers of increased BMI. Despite assuming that obesity and insulin resistance precedes DM, FFQ may not be useful in the assessment of unfavorable dietary patterns among subjects at risk for glucose intolerance, such as Japanese-Brazilians with elevated BMI.

Weight gain in adulthood and risk of developing glucose tolerance disturbance: a study of a Japanese-Brazilian population. Japanese-Brazilian Diabetes Study Group

We examined the data from 530 subjects enrolled in a survey on the prevalence of diabetes in a Japanese-Brazilian population aged 40-79 years. Past self-reported and current weight values were analysed. Student t test was used to compare anthropometric measures between subjects with and without disturbance of glucose tolerance (DGT), hypertension and dyslipidemia. Point and interval estimates of the weight at 20 years-, age- and sex-adjusted odds ratios (OR) were obtained by logistic regression analysis to evaluate the relationship between these diseases and the percent weight gain. Subjects with DGT, hypertension or dyslipidemia tended to have higher BMI during adulthood and to gain more weight in a shorter interval of time. Also, they presented higher waist-to-hip ratio and plasma glucose and worse lipid profile. OR were consistent with associations between chronic diseases and percent weight gain. Trend test of OR indicated that the risk of developing DGT alone or combined with hypertension and abdominal obesity increased 2% and 15% by percent unit of gained weight, respectively, as compared with those subjects with stable weight. Weight gain and the rate by which this occurs during lifetime may confer increased risk of chronic diseases. We suggested that preventive measures against obesity, i.e. the maintenance of healthy body weight lifelong, are necessary to minimize the occurrence of these diseases, also among migrant populations such as the Japanese-Brazilians.

Frequency of islet cell autoantibodies (IA-2 and GAD) in young Brazilian type 1 diabetes patients

Type 1 diabetes, as an autoimmune disease, presents several islet cell-specific autoantibodies such as islet cell antibody (ICA), anti-insulin, anti-glutamic acid decarboxylase (GAD) and the antibody (Ab) against tyrosine phosphatase (PTP)-like protein known as ICA-512 (IA-2). In order to determine the frequency of the anti-GAD and anti-IA-2 autoantibodies in Brazilian type 1 diabetes patients we studied 35 diabetes mellitus (DM) type 1 patients with recent-onset disease (</=12 months) and 37 type 1 diabetes patients with long-duration diabetes (>12 months) who were compared to 12 children with normal fasting glucose. Anti-GAD65 and anti-IA-2 autoantibodies were detected with commercial immunoprecipitation assays. The frequency of positive results in recent-onset DM type 1 patients was 80.0% for GADAb, 62.9% for IA-2Ab and 82.9% for GADAb and/or IA-2Ab. The long-duration type 1 diabetes subjects presented frequencies of 54.1% for GADAb and IA-2Ab, and 67.5% for GAD and/or IA-2 antibodies. The control group showed no positive cases. Anti-GAD and IA-2 assays showed a high frequency of positivity in these Brazilian type 1 diabetes patients, who presented the same prevalence as a Caucasian population.

Comparison of glucose tolerance categories according to World Health Organization and American Diabetes Association diagnostic criteria in a population-based study in Brazil. The Japanese-Brazilian Diabetes Study Group

OBJECTIVE

To compare the prevalence of different categories of glucose tolerance in a Japanese-Brazihan population using World Health Organization (WHO) and American Diabetes Association (ADA) diagnostic criteria. RESEARCH DIVISION AND METHODS: The analyses were based on the data obtained from a study conducted in a representative sample of the Japanese-Brazilian population composed of 647 subjects (40-79 years) who were submitted to a 2-h oral glucose tolerance test. Prevalence of glucose tolerance categories and the level of agreement (K statistics) were obtained using WHO and ADA criteria. Cardiovascular risk profile of the subjects with different diagnostic categories were compared.

RESULTS

Similar prevalences of diabetes were found considering both criteria (WHO, 20.3%; ADA, 19.2%). The prevalence of impaired glucose tolerance (IGT) by WHO criteria was 14.7%, contrasting with 7.4% of impaired fasting glucose (IFG) by ADA criteria. Subjects with discordant diagnostic categories by the criteria, considered at risk for diabetes (IGT/IFG), showed a worse metabolic profile than the concordant normal subjects. However, subjects with discordant diagnoses who had IGT or diabetes by WHO criteria but who were normal by ADA criteria exhibited a higher number of cardiovascular risk factors (higher blood pressure and triglyceride and low HDL cholesterol) than those who were discordant (IFG/diabetes) by ADA criteria but normal by WHO criteria.

CONCLUSIONS

Although the number of diabetic subjects was similar between the criteria, those identified as being at risk for diabetes were quite distinct. Fewer subjects were classified as having IFG by ADA criteria than as having IGT by WHO criteria. Abnormal glucose tolerance based on WHO criteria seems to identify a worse cardiovascular profile than abnormal tolerance based on ADA criteria. Follow-up studies are necessary to know the prognostic significance of IFG to predict subsequent diabetes.

The use of confocal laser scanning microscopy to analyze the process of parasitic protozoon-host cell interaction

In this communication we review the results obtained with the confocal laser scanning microscope to characterize the interaction of epimastigote and trypomastigote forms of Trypanosoma cruzi and tachyzoites of Toxoplasma gondii with host cells. Early events of the interaction process were studied by the simultaneous localization of sites of protein phosphorylation, revealed by immunocytochemistry, and sites of actin assembly, revealed by the use of labeled phaloidin. The results obtained show that proteins localized in the interaction sites are phosphorylated. The process of formation of the parasitophorous vacuole was monitored by labeling the host cell surface with fluorescent probes for lipids (PKH26), proteins (DTAF) and sialic acid (FITC-thiosemicarbazide) before interaction with the parasites. Evidence was obtained indicating transfer of components of the host cell surface to the parasite surface in the beginning of the interaction process. We also analyzed the distribution of cytoskeletal structures (microtubules and microfilaments visualized with specific antibodies), mitochondria (visualized with rhodamine 123), the Golgi complex (visualized with C6-NBD-ceramide) and the endoplasmic reticulum (visualized with anti-reticulin antibodies and DIOC6) during the evolution of intracellular parasitism. The results obtained show that some, but not all, structures change their position during evolution of the intracellular parasitism.

[Increase in mortality associated with the presence of diabetes mellitus in Japanese-Brazilians]

OBJECTIVE

As part of a study involving Japanese migrants, living in a developed city in the state of S. Paulo, Southeastern Brazil, a four-year experience of mortality among diabetic and non-diabetic subjects is described and their respective death rates are compared. In 1993, a cohort of 530 Japanese-Brazilians (236 issei or 1st generation and 294 nisei or 2nd generation) of both sexes, aged 40 from to 79 years old, were identified.

RESEARCH DESIGN AND METHOD

At that time, 91 (17%) were classified as non-insulin-dependent diabetic subjects (NIDDM), 90 (17%) with impaired glucose tolerance (IGT) and 349 (66%) as normal, according to WHO criteria. In 1996, families were questioned with a view detecting the deaths which had occurred among the subjects previously studied. This information, in addition to that from death certificates was used to record the date and the causes of death. Mortality rates for all causes and for specific causes (circulatory and renal diseases) were obtained for the three groups of subjects, by glucose tolerance status. Proportional hazard regression models were used to compare the mortality rates, adjusted for several covariables (gender, age, generation, hypertension, dyslipidemia, obesity and serum creatinine).

RESULTS AND CONCLUSIONS

Crude mortality rate ratios for all causes and specific causes, for NIDDM, and normal subjects were 2.95 (95% CI: 1.10-7.62) and 4.57 (95% CI: 1.31-16.48), respectively. No difference was observed between the crude mortality rate ratio for IGT and normal subjects. After simultaneous adjustments for the covariates, higher mortality rates for specific causes were observed among NIDDM than in the normal subjects (mortality rates ratio: 3.86; 95% CI: 1.11-13.38). These results in Japanese-Brazilians are consistent with previous reports of increased mortality in other diabetic subjects, thus confirming the adverse effect of this metabolic disturbance on mortality among diabetic subjects.

Abnormal nocturnal blood pressure fall in normotensive adolescents with insulin-dependent diabetes is ameliorated following glycemic improvement

Lack of the physiological nocturnal fall in blood pressure (BP) has been found in diabetics and it seems to be related to the presence of diabetic complications. The present study examined the changes in the nocturnal BP pattern of 8 normotensive insulin-dependent diabetic adolescents without nephropathy following improvement in glycemic control induced by an 8-day program of adequate diet and exercise. The same number of age- and sex-matched control subjects were studied. During the first and eighth nights of the program, BP was obtained by ambulatory BP monitoring. After a 10-min rest, 3 BP and heart rate (HR) recordings were taken and the mean values were considered to represent their awake values. The monitor was programmed to cuff insufflation every 20 min from 10:00 p.m. to 7:00 a.m. The glycemic control of diabetics improved since glycemia (212.0 +/- 91.5 to 140.2 +/- 69.1 mg/dl, P < 0.03), urine glucose (12.7 +/- 11.8 to 8.6 +/- 6.4 g/24 h, P = 0.08) and insulin dose (31.1 +/- 7.7 to 16.1 +/- 9.7 U/day, P < 0.01) were reduced on the last day. The mean BP of control subjects markedly decreased during the sleeping hours of night 1 (92.3 +/- 6.4 to 78.1 +/- 5.0 mmHg, P < 0.001) and night 8 (87.3 +/- 6.7 to 76.9 +/- 3.6 mmHg, P < 0.001). Diabetic patients showed a slight decrease in mean BP during the first night. However, the fall in BP during the nocturnal period increased significantly on the eighth night. The average awake-sleep BP variation was significantly higher at the end of the study (4.2 vs 10.3%, P < 0.05) and this ratio turned out to be similar to that found in the control group (10.3 vs 16.3%). HR variation also increased on the eighth night in the diabetics. Following the metabolic improvement obtained at the end of the period, the nocturnal BP variation of diabetics was close to the normal pattern. We suggest that amelioration of glycemic control may influence the awake-sleep BP and HR differences. This effect may be due at least in part to an attenuated insulin stimulation of sympathetic activity.

Is insulin or its precursor independently associated with hypertension? An epidemiological study in Japanese-Brazilians

Japanese individuals living outside Japan are more susceptible to chronic diseases included in the insulin resistance syndrome. Hyperinsulinemia and hypertension are associated, but large studies adjusting for confounders are still required. The present evaluated if insulin (I) or proinsulin (PI) was associated with hypertension after adjustment for other risk factors, in first (n=238) and second (n=292) generation Japanese-Brazilians, aged 40 to 79 years, living in a developed city in Brazil. Blood pressure (BP) was measured by random-zero sphygmomanometry. People with mean systolic/diastolic BP >140/90 mm Hg or taking antihypertensive drugs were considered hypertensive. Diagnosis of diabetes was based on results of an oral glucose tolerance test using WHO criteria. I and PI after fasting and 2 hours after glucose load were determined by specific immunofluorimetric assays. The first generation was older than the second (65.6+/-9.2 versus 53.6+/-8.4 years, P<.01) and male/female ratios were 1.14 and 0.87, respectively. The age-adjusted prevalence of hypertension was 29.2% with no difference between sexes or generations. Higher body mass index (25.2+/-4.3 versus 23.8+/-3.3 kg/m2), waist-to-hip ratio (0.939+/-0.067 versus 0.919+/-0.073), plasma glucose (6.3+/-2.3 versus 5.6+/-1.8 mmol/L), cholesterol (5.74+/-1.19 versus 5.48+/-1.08 mmol/L), and creatinine (74+/-26 versus 83+/-36 micromol/L) were found among the hypertensives (P<.05). Univariate analyses showed associations of obesity, diabetes, and dyslipidemia with hypertension. Logistic regression analyses demonstrated that 2-hour I (OR, 1.22; 95% CI, 1.02 to 1.46) and fasting PI (OR, 1.14; 95% CI, 1.00 to 1.31) remained significantly associated with hypertension, after adjustment for age, sex, generation, family history of hypertension, smoking habits, waist-to-hip ratio, serum creatinine, glucose intolerance, and dyslipidemia. Japanese-Brazilians have a higher prevalence of hypertension than the general population in Brazil. High levels of 2-hour I, seen in hypertensives, may be interpreted as independent risk factors for hypertension in this population. Our findings suggest that fasting PI should be useful, in addition to insulin, to assess risk factors for hypertension in epidemiological studies.

Factors associated with the development of renal complications of diabetes mellitus in São Paulo city

The incidence of diabetic end-stage renal failure (ESRF) varies worldwide and risk factors have been demonstrated in several populations. The objective of the present study was to identify possible factors associated with the risk of development of ESRF in patients with diabetes mellitus (DM). Two groups of diabetic subjects were included in a case-control study: 1) one group was submitted to renal replacement therapies, attending dialysis centers in São Paulo city and 2) the same number of controls without clinical nephropathy (two negative dipstick tests for urine protein), matched for duration of DM, were obtained from an outpatient clinic. A standardized questionnaire was used by a single investigator and additional data were obtained from the medical records of the patients. A total of 290 diabetic patients from 33 dialysis centers were identified, and 266 questionnaires were considered to contain reliable information. Male/female ratios were 1.13 for ESRF and 0.49 for the control group. A higher frequency of men was observed in the ESRF group when compared with controls (53 vs 33%, P < 0.00001), although logistic regression analysis did not confirm an association of gender and diabetic nephropathy (DN). Similar proportions of non-white individuals were found for both groups. Patients with insulin-dependent diabetes mellitus (IDDM) were less common than patients with non-insulin-dependent diabetes mellitus (NIDDM), particularly in the control group (3.4 vs 26.3%, P < 0.00001, for controls and ESRF patients, respectively); this type of DM was associated with a higher risk of ESRF than NIDDM, as determined by univariate analysis or logistic regression (OR = 4.1). Hypertension by the time of the DM diagnosis conferred a 1.4-fold higher risk of ESRF (P = 0.04), but no difference was observed concerning the presence of a family history. Association between smoking and alcohol habits and increased risk was observed (OR = 4.5 and 5.9, respectively, P < 0.001). A 2.4-fold higher risk of ESRF was demonstrated in patients with multiple hospitalizations due to DM decompensation, which suggested poor metabolic control. Photocoagulation and neuropathy were found to be strongly associated with ESRF but not with macrovascular disease. Data collected in our country reinforce the higher risk attributable to IDDM and the association between hypertension and the progression of DN. Indirect evidence for an association with metabolic control is also suggested.

Different urinary albumin responses to submaximal exercise by normoalbuminuric diabetic children and controls

It is not clear if exercise could be useful to identify diabetic patients at risk for the development of nephropathy. We evaluated the responses of blood pressure (BP) and urinary albumin (Alb) and retinol-binding protein (RBP) excretion to standardized sub-maximal exercise in 17 normoalbuminuric normotensive children with IDDM and 17 matched normal subjects. RBP was used as an index of tubular function. Standardization of exercise load was based on heart rate (HR) which was maintained at 70% of the maximum calculated to age. A step exercise test lasted for 35 min; baseline BP and HR were taken at midtime and during cooling down. Pre- and postexercise urines were obtained for Alb, RBP and creatinine determinations. Both groups showed a significantly increased systolic BP at the midpoint but the percent variations were not different. HR responses did not differ and demonstrated the exercise effectiveness. Great variability in Alb excretion was observed within the normal range for both groups. The baseline Alb/creatine ration was not significantly different between normal and diabetic subjects, but became different following exercise (6.6 +/- 4.1 vs 17.7 +/- 18.7 mg/g. P < 0.05). While this ratio decreased in the control group (14.8 +/- 11.1 to 6.6 +/- mg/g, P < 0.02), it increased (9.0 +/- 7.1 to 17.7 +/- 18.7 mg/g, P = 0.05) in diabetic patients. Percent variations in the two groups occurred in opposite directions and were significantly different. RBP/creatinine followed the same pattern within each group; normals showed a tendency to a decrease (0.058 +/- 0.064 to 0.030 +/- 0.039 microgram/g, P = 0.05) and diabetic patients to an increase (0.116 +/- 0.125 to 0.247 +/- 0.247 microgram/g, P = 0.06). We conclude that there was a variable proteinuric response to exercise among diabetic subjects with normal renal function as evaluated by albumin excretion. A subset of IDDM patients responded abnormally to the exercise stress, increasing albumin excretion to levels compatible with microalbuminuria. Whether this heterogeneity reflects individual risk for diabetic renal disease require further investigation.

Altered blood pressure profile, autonomic neuropathy and nephropathy in insulin-dependent diabetic patients

To evaluate the relationship between autonomic neuropathy (AN) and nephropathy we measured 24-h blood pressure (BP) and overnight urinary albumin excretion (UAE) in 38 patients with insulin dependent diabetes mellitus (IDDM). Autonomic function was evaluated by the heart rate response to deep breathing. Valsalva maneuver, heart rate at rest and BP variation with posture. Sympathetic cutaneous reflex was also tested in both inferior and superior limbs. Patients with mean day diastolic BP (DDBP) < or = 90 mmHg without AN (N = 15) compared to 12 normal controls had similar BP values, but compared to those with DDBP < or = 90 mmHg and AN (N = 12) they had lower night diastolic BP (NDBP) (66 +/- 4.8 vs 72 +/- 8.8 mmHg: p < 0.05) and UAE (9.8 +/- 2.3 vs 107.2 +/- 3.5 micrograms/min; p < 0.001). No difference in DDBP was observed between these two diabetic groups (80 +/- 3.9 vs 83 +/- 6.1 mmHg). Of the 11 patients with DDBP > 90 mmHg, only three were free of AN and only two of the eight with AN where free of diabetic nephropathy. The percentage day/night changes in systolic BP were lower in patients with AN (13 vs 7.9%; p < 0.05) and were inversely related to autonomic score, used as an index of the degree of autonomic dysfunction (r = -0.48; p < 0.01) and to UAE (r = -0.39; p < 0.05). Furthermore, UAE correlated with autonomic score (r = 0.69; p < 0.0001) and with NDBP (r = 0.44; p < 0.01). Our results show that AN in IDDM patients is associated with a reduced nocturnal fall in BP and suggest a pathogenic role of autonomic dysfunction in the development of diabetic nephropathy, possibly favoring both BP elevation during the night and increases in intraglomerular pressure.

Proinsulin and insulin levels according to glucose tolerance among Japanese-Brazilians, aged 40-79 years. Japanese-Brazilian Diabetes Study Group

This study of the Japanese-Brazilians living in Bauru, Sao Paulo, Brazil, aimed at determining the prevalence of DM in the first (Issei) and second (Nisei) generations, according to WHO criteria. Insulin and proinsulin were determined by new immunofluorimetric assays (IMFA), that measure true insulin and intact proinsulin, at fasting and 2 h after glucose load. The data showed a very scattered distribution, so only medians are shown and no statistical testing applied. There was a tendency for higher proinsulin levels in the diabetic groups. The highest fasting proinsulin levels were seen in the diabetic patients, either obese or non-obese. The post-load insulin levels were higher in diabetic and IGT individuals, compared to normals. Both generations showed a distinct behaviour for the obese and non-obese groups, and no major differences were observed between generations. This population seems to be sensitive to environmental changes, since the obese groups showed the higher levels of proinsulin and insulin. In the evaluation of the role of the environmental factors in the pathogenesis of DM, proinsulin and insulin levels could act as early markers of pancreatic dysfunctions.

Disturbances of glucose and lipid metabolism in first and second generation Japanese-Brazilians. Japanese-Brazilian Diabetes Study Group

Increased prevalence of self-reported NIDDM in Japanese-Brazilians was reported when compared to Japan. This study aimed at determining the prevalence of NIDDM and IGT in Japanese-Brazilians living in the city of Bauru, São Paulo, Brazil. The impact of western environment on the frequency of obesity, dyslipidemia and hypertension was investigated. All Issei (first generation; n = 238) and a random sample of Nisei (second generation; n = 292), aged 40-79 years, were selected for clinical examination and OGTT (WHO criteria). Age-adjusted prevalence of NIDDM did not differ between men and women for Issei (12.4 vs. 11.6%, respectively), but it became different for Nisei (21.7 vs. 11.4%, P < 0.03) due to an increased rate among men. Increased IGT prevalence was also observed between Issei and Nisei men (8.5 vs. 19.3%, P < 0.03). Issei women had a higher IGT rate than Issei men (27. 3 vs. 8.5%, P < 0.0005). Body mass index (BMI) was higher in the second generation (24.1 +/- 3.6 vs. 23.3 +/- 3.1 kg/m2, P < 0.00005) and also the frequency of obesity, defined as BMI > 25 kg/m2. Comparison of waist/hip ratio by gender showed that only among women, Nisei had lower ratio than Issei (0.90 vs. 0.88, P < 0.05). Nisei had a lower total and LDL-cholesterol than Issei but triglyceride and HDL-cholesterol did not differ. Nisei women (younger than the Issei) had lower triglyceride and total cholesterol. This pattern was not seen between the two generations of men. Considering the mean blood pressure values, Issei and Nisei groups with normal glucose tolerance were not hypertensive. Systolic blood pressure was lower in Nisei and the inverse was found concerning diastolic levels. NIDDM prevalence in Japanese-Brazilians is higher than in Japan and in the general Brazilian population. Besides environment, genetic factors may confer susceptibility to NIDDM when they are exposed to a western environment. Before developing glucose intolerance, disturbances of lipid profile and blood pressure could be detected. Nisei may be more affected due to a longer exposure to an unfavorable environment and these changes seem to occur earlier among men than women.

Effect of improved glycemic control on blood pressure and albuminuria of insulin-dependent diabetes without nephropathy

To assess the effect of glycemic control on blood pressure (BP) and albumin excretion rate (AER) in insulin-dependent diabetes, 35 patients (age 12.6 +/- 2.7 years) and 45 matched control subjects (11.9 +/- 1.8 years) were studied at an educational camp (Study I). They were evaluated at the beginning and at the end of a 9-day program of adequate diet and exercise twice daily, which induced statistically significant reductions in urinary glucose (18 +/- 21 to 5 +/- 7 g/12 h, P < 0.01) and in insulin requirement (42 +/- 20 to 31 +/- 12 U/day, P < 0.01) in the diabetic group. The mean BP and AER of the diabetic patients fell from 74 +/- 11 to 69 +/- 11 mmHg, P < 0.001, and from 4.9 +/- 6.0 to 2.1 +/- 2.0 micrograms/min, P < 0.01, and a correlation was found between AER and urinary glucose. In contrast, controls showed a lower reduction in BP and no change in AER. To evaluate the mechanisms involved in BP fall another group of 39 diabetics (age 12.7 +/- 2.1 years) was submitted to the same 9-day program and also to improved glycemic control (Study II). Changes in BP (79 +/- 11 to 76 +/- 11 mmHg, P < 0.05) were slighter than in the previous study. Initial creatinine clearance was high and fell to the normal range at the end of the study (159 +/- 99 to 127 +/- 42 ml min-1 (1.73 m2)-1, P < 0.05). Urinary aldosterone decreased from 5.3 +/- 3.9 to 3.4 +/- 2.4 micrograms/24 h (P < 0.05), and fractional Na+ excretion tended to increase. Initial and final metanephrine values did not differ. Changes in mean BP did not correlate with changes in aldosterone, insulin requirement or urinary glucose. The decreases in hyperfiltration and AER may have been due to the improved glycemic control induced by this educational program. Exercise may be responsible for BP reduction in diabetics and controls. BP changes particularly in diabetics could be attributed to the inhibition of the renin-angiotensin-aldosterone system and/or to decreased insulin requirement. The contribution of a negative Na+ balance consequent to decreased plasma insulin levels to the BP fall cannot be excluded.

Antibodies to bovine serum albumin in Brazilian children and young adults with IDDM

OBJECTIVE

To evaluate the prevalence of IgG antibodies to bovine serum albumin (BSA) in a cohort of Brazilian children and young adults with IDDM.

RESEARCH DESIGN AND METHODS

Sera from 81 subjects with < 1 year of IDDM (group 1), III subjects with > 1 year of IDDM (group 2), and 207 normoglycemic subjects were tested using an immunofluorimetric assay. A receiver-operating-characteristic curve was used to establish the threshold of anti-BSA antibody titers defining the positivity of the assay.

RESULTS

The distribution of the fluorimetric index (FI) of anti-BSA antibodies did not have a gaussian profile. Rank sum of FI was significantly higher in patients than in control subjects (P < 0.0001). Average logFI values of both IDDM groups were significantly higher than that of the control group (P < 0.005 for both groups). There was a trend toward higher FI levels in group 1 than in group 2 (P = 0.06). A FI cutoff of 0.7 optimized the ratio of true-positive to false-positive of the assay, with the best equilibrium between sensitivity and specificity. The prevalence of anti-BSA antibodies was 52% in group 1, 47% in group 2, and 28% in the control group (P = 0.0001). An independent association between anti-BSA antibodies and IDDM, with an odds ratio of 3.03 (P < 0.0001), was observed in a logistic regression analysis. However anti-BSA antibodies explained only 5% of the variability of IDDM versus NIDDM.

CONCLUSIONS

Our results confirm that the prevalence of anti-BSA antibodies is higher in IDDM subjects than in control subjects, even after 1 year of diabetes. However, a large overlap of antibody titers is observed in patients and control subjects, suggesting that anti-BSA antibodies are neither sensitive nor specific markers of IDDM.

[Prevention of AIDS: experience with adolescents from a state elementary school in Porto Allegre]

This article refers to a participating experience in AIDS prevention with teenagers from 5th to 8th grade of a state elementary school, through workshops. This working method uses participating technics to allow relaxation, discussion and theme reflection by the group. The results obtained with this work of information and health education indicate the possibility of stimulating preventive acting development through reflection on the health-disease process, which involves HIV virus infection and comprehension of the disease extension and gravity for public health.

Self-reported prevalence of non-insulin-dependent diabetes mellitus in the 1st (Issei) and 2nd (Nisei) generation of Japanese-Brazilians over 40 years of age

The immigration of Japanese people to Brazil began in 1908 with two major waves, from 1925 to 1940 and from 1952 to the 1960s. Brazil has the largest population (about 1,288,000) of Japanese origin outside Japan with varying age groups. A mortality study revealed that diabetes as an underlying cause of death was higher in the first-generation Japanese than in Japan (3.4 vs. 1.9 per 100,000 for men, and 7.2 vs. 1.9 for women). The self-reported prevalences of known diabetes in subjects aged 40 years or older were obtained by questionnaires from three sources. In six Japanese cultural associations in Säo Paulo city, the prevalences were 9.7% and 6.9% for the first generation (mean age 61.5 years) and for the second generation (mean age 40.0 years), respectively. Age-adjusted prevalences, according to the Brazilian population in the 1980 national census, were 6.9% and 8.1% for the first and second generations. According to a study carried out as a part of a socioeconomic census of the Japanese population in Brazil, the prevalences of diabetes were 7.4% and 5.2%, and the age-adjusted prevalences were 5.3% and 5.8% in the first and second generations, respectively. Another study carried out for employees of a bank, owned by Japanese-Brazilian community members, revealed crude prevalences of diabetes in the first and second generations of 7.1% and 4.2%, and age-adjusted prevalences of 7.3% and 8.2%, respectively. These data indicate an increased prevalence of diabetes in this population compared to Japan, suggesting the importance of environmental factors in the pathogenesis of diabetes.

Comparative study of two tests of renal diluting ability in Bartter's syndrome

1. Different results concerning distal NaCl reabsorption have been reported for patients with Bartter's syndrome in tests of renal diluting ability. We describe clearance studies performed on 3 patients with Bartter's syndrome using different routes for body fluid content expansion: water was given orally and 0.45% NaCl solution intravenously. The impact of fluid composition was evaluated in one patient who additionally underwent a "reverse test": i.e., intravenous 5% glucose in water and an oral load of 0.45% NaCl solution. 2. Urine flow per ml glomerular filtration rate (GFR) reached higher levels when the iv route was used (20.6 +/- 1.8 vs 11.8 +/- 5.7%, P < 0.05). Fractional excretion of Na+, Cl- and osmoles increased during NaCl infusion but not during the oral load. Also, distal delivery of solute increased and was greater than that observed in the oral test (21.9 +/- 5.5 vs 11.4 +/- 2.1%, P < 0.05). 3. In contrast, fractional distal chloride reabsorption in the iv test reached subnormal values which were lower than in the oral load test (65.0 +/- 11.2 vs 86.8 +/- 11.0%, P < 0.05). A positive correlation was observed between distal delivery and Cl- fractional excretion (r = 0.87; P < 0.005). In one patient, the 5% glucose infusion resulted in greater urine flow and distal delivery when compared to distilled water or 0.45% NaCl taken orally (28.1 vs 13.3 ml/min and 27.3 vs 12.8%, respectively). These values were as high as those observed during iv administration of hypotonic saline. 4. The iv route was always associated with lower rates of fractional distal chloride reabsorption (70.7 vs 89.1%) regardless of the solute composition and should be recommended when testing the renal diluting ability of patients suspected of Bartter's syndrome.

Familial hypertension and albuminuria in normotensive type I diabetic patients

An inherited predisposition to hypertension may increase susceptibility to nephropathy in type I diabetes. We evaluated the influence of a family history of essential hypertension on albuminuria in normotensive, normoalbuminuric type I diabetic patients. Forty-two diabetics (12.9 +/- 2.04 years) were divided into three groups according to tertiles of albumin excretion rate (group 1, 1.27 +/- 0.35; group 2, 2.43 +/- 0.49; group 3, 6.37 +/- 3.43 micrograms/min; P < .001). Familial hypertension was considered to be present if the patient had one parent or grandparent on antihypertensive therapy. The three groups did not differ concerning age, diabetes duration, insulin requirement, body mass index, blood pressure, and urinary glucose excretion. Albumin excretion rate did not correlate with any parameter studied. The frequency of hypertension was significantly lower among the relatives of the patients from group 1 compared with those from groups 2 and 3 (28.6% versus 64.3% versus 78.6%, P < .03). Our data suggest that a familial antecedent of hypertension in normoalbuminuric type I diabetic patients is associated with a high normal albumin excretion rate not related to increases in blood pressure. Early changes in renal hemodynamics, seen in patients with a predisposition to hypertension, may contribute to increments in albuminuria even within the normal range.

Population-based incidence of IDDM in the state of São Paulo, Brazil

OBJECTIVE

To study the incidence of IDDM among children, infants to 14 yr of age, in the state of São Paulo, Brazil, 1987-1991.

RESEARCH DESIGN AND METHODS

A prospective population-based register was established, using physician reports of newly diagnosed IDDM patients < 15 yr of age as the primary source of case identification and school surveys as the main secondary source. Data were collected according to the methods recommended by the Diabetes Epidemiology Research International group.

RESULTS

Case ascertainment was estimated at 95.0, 92.8, and 98.8% complete for each of the three cities studied. The average annual IDDM incidence was 7.6/100,000 inhabitants (95% confidence interval, 5.6-9.7). We found a higher incidence rate in girls than boys.

CONCLUSIONS

The incidence of childhood IDDM in a tropical region in South America (São Paulo, Brazil) is in the middle incidence range observed in developed countries throughout the world. Increased incidence of IDDM in girls compared with boys will be tested by the ongoing Brazilian incidence study being developed in 18 other centers across the country.

Acute hemodynamic action of captopril in congestive heart failure: contrasts between refractory and untreated patients

To compare the hemodynamic mode of action of captopril in patients with Congestive Heart Failure (CHF) with high- or low-plasma renin activity, we studied the systemic and renal hemodynamic changes induced by this drug in patients with refractory CHF (Group I) or untreated CHF (Group II). Plasma Renin Activity (PRA) was 7.46 +/- 3.7 ng/ml/hr in Group I and 1.15 +/- 0.45 ng/ml/hr in Group II. After the administration of captopril, these values increased to 14.35 +/- 6.19 and to 1.99 +/- 0.76 ng/ml/hr respectively (p less than 0.05). We observed that patients of Group I responded with increases in cardiac index and stroke volume and diminutions in total peripheral resistance, but Group II did not show any significant change in these variables. In contrast to this difference in responses between the refractory and untreated patients, both groups showed similar decreases in pulmonary artery and wedge pressures. Both groups also showed similar increases in plasma volume and effective renal plasma flow, and decreases in renal vascular resistance. These results show that captopril has predominantly venodilator effects in patients with CHF with low PRA levels, and it acts as a mixed vasodilator in patients refractory to conventional therapy, receiving high doses of diuretics, and in whom PRA is elevated. Our results also suggest that the venodilator action of captopril is not mediated by the Renin-Angiotensin System.