Prostatic stromal microenvironment and experimental diabetes.

The diabetes causes alterations in various organ systems, including the male accessory sex glands. The prostate is very important in the reproductive process and it is a frequent target of malignant changes. The aim of this work was to demonstrate the histochemical and ultrastructural alterations in the prostate of diabetic animals. Two groups of animals were utilized: control and non-obese diabetic mice (NOD). Twelve days after the characterization of diabetic status the ventral prostate was collected, fixed in Karnovsky and paraformaldehyde, processed for histochemistry and TEM associated to stereology. The results showed reduction of the epithelial area and increasing of the stromal area with muscular and collagen hypertrophy in the prostatic gland. It was characterized the development of prostatic intraepithelial neoplasia, inflammatory processes and dilation of the organelles involved in the secretory process. It was concluded that diabetes besides damaging the reproductive process, affects the glandular homeostasis favoring the development of prostatic pathologies.

Assessment of central venous catheter-associated infections using semi-quantitative or quantitative culture methods

Semiquantitative (Maki) and quantitative (Brun-Buisson) culture techniques were employed in the diagnosis of catheter-related bloodstream infections(CRBSI) in patients who have a short-term central venous catheter (inserted for 30 days). The diagnosis of CRBSI was based on the results of semiquantitative and quantitative culture of material from the removed catheters. Catheter tips (118) from 100 patients were evaluated by both methods. Semiquantitative analysis revealed 34 catheters (28.8%) colonized by greater or equal 15 colonyforming units (cfu), while quantitative cultures (34 catheters, 28.8%) showed the growth of greater or equal 103 cfu/mL. Bacteremia was confirmed in four patients by isolating microorganisms of identical species from both catheters and blood samples. Using the semiquantitative culture technique on short-term central venous catheter tips, we have shown that with a cut-off level of greater or equal 15 cfu, the technique had 100.0% sensitivity, specificity of 68.4%, 25.0% positive predictive value (PPV) and 100.0% negative predictive value (NPV), efficiency of 71.4% and a prevalence of 9.5%. The quantitative method, with a cut-off limit of greater or equal 103 cfu/mL, gave identical values: the sensitivity was 100.0%, specificity 68.4%, positive predictive value (PPV) 25.0%, negative predictive value(NPV) 100.0%, efficiency 71.4% and prevalence 9.5%. We concluded that the semiquantitative and quantitative culture methods, evaluated in parallel, for the first time in Brazil, have similar sensitivity and specificity.

Marking with pigments for identification of flies in experimental populations of Megaselia scalaris Loew.

The insect marking technique of Tadei & Mourão (1976) is until now the only experimental method allowing real-age determination of each individual in a population and, consequently, determination of age structure in a given population. We propose an improvement of this technique, used here to determine the population age structure of the geographical strain SR of the Megaselia scalaris Loew (Diptera; Phoridae), maintained by serial transfer technique at constant temperatures 25 +/- 1.0 degree C and 20 +/- 1.0 degree C. Determining the age structure allowed the calculation of the real longevity of the flies and the identification of the effect of temperature decisive factors in these are the technique of marking insects, because otherwise we would only have an estimate, and depending on mistakes there in, the effect of the determinant factor (temperature) cannot be detected.

Marking with pigments for identification of flies in experimental populations of Megaselia scalaris Loew

A técnica de marcação de insetos de Tadei & Mourão (1976) é, até o momento, o único método experimental que possibilita determinar a idade real de cada indivíduo na população e, conseqüentemente, determinar a estrutura etária da mesma. Para isto propomos um aprimoramento dessa técnica, utilizada aqui para determinar a estrutura etária de populaçäes da linhagem geográfica SR do díptero forídeo Megaselia scalaris Loew, mantidas pela técnica da transferência seriada em câmaras com temperatura constante de 25 ñ 1,0§C e 20 ñ 1,0§C. O estabelecimento da estrutura etária permitiu calcular a longevidade real das moscas e detectar o efeito ambiental temperatura, sendo fator determinante neste trabalho a marcação dos insetos, pois se não o fosse, teríamos somente estimativas e, dependendo do erro cometido na estimação, o efeito do fator de interesse (temperatura) poderia não ser detectado.

Estimation of population profiles of two strains of the fly Megaselia scalaris (Diptera: Phoridae) by bootstrap simulation

Based on experimental population profiles of strains of the fly Megaselia scalaris (Phoridae), the minimal number of sample profiles was determined that should be repeated by bootstrap simulation process in order to obtain a confident estimation of the mean population profile and present estimations of the standard error as a precise measure of the simulations made. The original data are from experimental populations founded with SR and R4 strains, with three replicates, which were kept for 33 weeks by serial transfer technique in a constant temperature room (25 ± 1.0°C). The variable used was population size and the model adopted for each profile was a stationary stochastic process. By these simulations, the three experimental population profiles were enlarged so as to determine minimum sample size. After sample size was determined, bootstrap simulations were made in order to calculate confidence intervals and to compare the mean population profiles of these two strains. The results show that with a minimum sample size of 50, stabilization of means begins

Estimation of population profiles of two strains of the fly Megaselia scalaris (Diptera: Phoridae) by bootstrap simulation.

Based on experimental population profiles of strains of the fly Megaselia scalaris (Phoridae), the minimal number of sample profiles was determined that should be repeated by bootstrap simulation process in order to obtain a confident estimation of the mean population profile and present estimations of the standard error as a precise measure of the simulations made. The original data are from experimental populations founded with SR and R4 strains, with three replicates, which were kept for 33 weeks by serial transfer technique in a constant temperature room (25 +/- 1.0 degrees C). The variable used was population size and the model adopted for each profile was a stationary stochastic process. By these simulations, the three experimental population profiles were enlarged so as to determine minimum sample size. After sample size was determined, bootstrap simulations were made in order to calculate confidence intervals and to compare the mean population profiles of these two strains. The results show that with a minimum sample size of 50, stabilization of means begins.

The development of resistance to caffeine in Drosophila prosaltans: productivity and longevity after ten generations of treatment.

The productivity of Drosophila prosaltans treated with six concentrations of caffeine (from 50 micrograms/ml to 2,500 micrograms/ml of culture medium) during ten generations (approximately 8 months) decreased in a dosage dependent manner in every generation, but at the end of the treatment the flies in all experiments recovered normal productivity, except for those treated with 2,500 micrograms/ml. Longevity in the tenth generation was significantly reduced in males and females only in the 2,500 micrograms/ml dosage, with males being much more affected than females. In a previous study in which the treatment was done in a single generation, productivity exhibited only a partial recovery when the treatment ceased and longevity was significantly reduced in 1,500 micrograms/ml dosages. The hypothesis of selection occurring in ten generations leading to recovery in productivity and to a reduction in the processes which cause a decrease in longevity is being considered.

[Age and racial geographic distribution of S hemoglobin in Brazil]. / Distribución geográfica etaria y racial de la hemoglobina S en Brasil.

OBJECTIVES: This paper was meant to analyse distribution of HbS carriers in Brazil, comprising its regional prevalence and the relationship with racial settlement and age groups. MATERIAL AND METHODS: 67,667 blood samples from 48 Brazilian towns were analysed from 1976 to 1988. Such samples were classified as Caucasoid and Negroid. The diagnosis was defined by means of qualitative electrophoresis in alkaline and acid pH, quantification of haemoglobin fractions, cytological studies and some cases were confirmed after examination of the parents. RESULTS: The study of those 67,667 samples allowed us to detect 1,492 HbS carriers (2.2%). That frequency is higher among Negroids (5.16%) than among Caucasoids (1.22%): Z = 22.1397 (Zcritical; 0.05 = 1.9600). Taking the HbS carrier distribution into consideration, we noticed that it is relatively homogeneous among Negroids and higher than 5% in 9 out of the 16 areas involved in the study. By classifying the age group of the areas in the general sample and by comparing the proportions, we found out that there are significant differences (chi 2 = 50.88; chi 2 critical; 0.05; 5 gl = 11.070). CONCLUSIONS: Sickle-cell anaemia diseases play an important role among the pathologies found in several countries, including Brazil. This paper shows that the carriers prevalence varies in the several areas under study and is higher among Negroids in almost all of them. The decreasing frequency occurring from North to South in the general samples and among Caucasoids may be assigned to the contribution of the Negroes in the interracial crossing, particularly in the Northeast.

Effects of caffeine on mating frequency and pre-copulation and copulation durations in Drosophila prosaltans.

Parameters of sexual behaviour were studied in Drosophila prosaltans treated with 2,500 micrograms/ml of caffeine per 1 ml of banana culture medium. The mating frequency and copulation duration were greater in control than in treated flies, while the pre-copulation duration was greater in treated flies than in controls. Statistical analysis showed that for the pre-copulation duration the difference was significant.

Sister-chromatid exchanges in beta-thalassaemic patients under conditions of in vivo and in vitro depletion of folic acid.

In order to investigate the effect of folate depletion, lymphocyte sister-chromatid exchange (SCE) rates were compared among homozygous beta-thalassaemic patients with low folic acid levels, heterozygous beta-thalassaemic patients with normal folate levels and healthy persons with normal haemoglobin, in cultures with both normal and depleted folate conditions. Significantly higher SCE rates were found in homozygous patients in all assays, but the in vitro folate depletion did not induce an increase in SCE frequency in any group.

Sister chromatid exchanges and chromosome aberrations in lymphocytes of nurses handling antineoplastic drugs.

Chromosomal aberrations (CA) and sister-chromatid exchanges (SCE) were investigated in peripheral lymphocytes of 15 nurses and nurse's aides handling cytostatic agents in hospital oncology units. Significantly increased frequencies were noted for both CA and SCE rates when the exposed individuals were compared with 15 nurses working in other hospital units and to a control sample matched by sex and age. This points to the need for emphasizing protective measures in the handling of anti-neoplastic agents.