Correlation between sodium and potassium excretion in 24- and 12-h urine samples

Low-sodium and high-potassium diets have been recommended as an adjunct to prevention and treatment of hypertension. Analysis of these nutrients in 24-h urine has been considered the reference method to estimate daily intake of these minerals. However, 24-h urine collection is difficult in epidemiological studies, since urine must be collected and stored in job environments. Therefore, strategies for shorter durations of urine collection at home have been proposed. We have previously reported that collecting urine during a 12-h period (overnight) is more feasible and that creatinine clearance correlated strongly with that detected in 24-h samples. In the present study, we collected urine for 24 h divided into two 12-h periods (from 7:00 am to 7:00 pm and from 7:00 pm to 7:00 am next day). A sample of 109 apparently healthy volunteers aged 30 to 74 years of both genders working in a University institution was investigated. Subjects with previous myocardial infarction, stroke, renal insufficiency, and pregnant women were not included. Significant (P < 0.001) Spearman correlation coefficients (r s) were found between the total amount of sodium and potassium excreted in the urine collected at night and in the 24-h period (r s = 0.76 and 0.74, respectively). Additionally, the 12-h sodium and potassium excretions (means ± SD, 95% confidence interval) corresponded to 47.3 ± 11.2%, 95%CI = 45.3-49.3, and 39.3 ± 4.6%, 95%CI = 37.3-41.3, respectively, of the 24-h excretion of these ions. Therefore, these findings support the assumption that 12-h urine collected at night can be used as a reliable tool to estimate 24-h intake/excretion of sodium and potassium.

Effect of castration on renal glycosaminoglycans and their urinary excretion in male and female rats with chronic renal failure

Glycosaminoglycans (GAGs) participate in a variety of processes in the kidney, and evidence suggests that gender-related hormones participate in renal function. The aim of this study was to analyze the relationship of GAGs, gender, and proteinuria in male and female rats with chronic renal failure (CRF). GAGs were analyzed in total kidney tissue and 24-h urine of castrated (c), male (M), and female (F) Wistar control (C) rats (CM, CMc, CF, CFc) and after 30 days of CRF induced by 5/6 nephrectomy (CRFM, CRFMc, CRFF, CRFFc). Total GAG quantification and composition were determined using agarose and polyacrylamide gel electrophoresis, respectively. Renal GAGs were higher in CF compared to CM. CRFM presented an increase in renal GAGs, heparan sulfate (HS), and proteinuria, while castration reduced these parameters. However, CRFF and CRFFc groups showed a decrease in renal GAGs concomitant with an increase in proteinuria. Our results suggest that, in CRFM, sex hormones quantitatively alter GAGs, mainly HS, and possibly the glomerular filtration barrier, leading to proteinuria. The lack of this response in CRFMc, where HS did not increase, corroborates this theory. This pattern was not observed in females. Further studies of CRF are needed to clarify gender-dependent differences in HS synthesis.

Nutritional status of children, inmates of a small institution for homeless children in the capital of the State of S. Paulo, Brazil

Nutritional surveys (food consumption, clinical and biochemichal) were conducted in a small institution for homeless children. Results showed that only 30% of the children presented adequate calorie intake. Most of the children presented adequate protein intake, but almost half consumed less than 2/3 of the calcium RDA considered necessary. Food handling, processing, and distribution also proved inadequate and wastage, high. Skinfold measurement showed up one case of obesity. Furthermore, most of the children presented clinical signs of vitamin A deficiency, mostly skin lesions; while about half presented clinical signs of riboflavin deficiency. Biochemical data showed that 63.6% had deficient plasma levels of vitamin A, none showed abnormal results for riboflavin excretion, four showed packed blood cell volume below normal, and all had normal hemoglobin levels. Stool examinations revealed a high rate of pathogenic protozoa (Hymenolepis nana), in fact, one of the highest in Brazilian literature.

Human cryptosporidiosis: detection of specific antibodies in the serum by an indirect immunofluorescence

Cryptosporidium sp., a coccidian parasite usually found in the faeces of cattle, has been recently implicated as an agent of human intestinal disease, mainly in immunocompromised patients. In the study realized, by an indirect immunofluorescence technique, specific immunoglobulins (IgG and IgM) have been demonstrated in human serum against Cryptosporidium oocysts. Purified oocysts were used as antigens in the indirect immunofluorecence assay. After analyzing this test in sera from selected groups of patients, the frequency of both specific IgG and IgM of immunocompetent children who were excreting oocysts in their faeces was 62% and in children with negative excretion of oocysts was 20% and 40%, respectively. In adults infected with the human immunodeficiency virus (HIV) and who were excreting Cryptosporidium in their stools, the frequency was 57% for IgG but only 2% for IgM. Twenty three percent of immunocompromised adults with not determined excretion of oocysts in their stools had anti-Cryptosporidium IgG in their sera. Children infected with human immunodeficiency virus had no IgM and only 14% had IgG detectable in their sera. The indirect immunoflorescence assay, when used with other parasitological techniques appears to be useful for retrospective population studies and for diagnosis of acute infection. The humoral immune response of HIV positive patients to this protozoan agent needs clarification.

In vitro susceptibility of Paracoccidioides brasiliensis yeast form to antifungal agents

A study was conducted to determine the susceptibility of P. brasiliensis yeast form to amphotericin B (A), ketoconazole (K), 5-fluorocytosine (5-FC) and rifampin (R). The three isolates tested produced minimal inhibitory concentrations (MICs) (mcg/ml) in the following range: A: 0.09-0.18; K: 0.001-0.007; 5-FC: 62.5-250 and R: 40-80. The minimal fungicidal concentrations (MFC) were several times higher than the corresponding MICs. Precise MFC for 5-FC were not obtained (> 500 mcg/ml). Combination of K plus A proved synergic, with the fractional inhibitory concentration (FIC) indices revealing synergy when the drugs were combined at the 1 to 1 and 1 to 5 MIC ratios. R (40 mcg/ml) appeared to antagonize K. These results indicate promise for the combined use of K plus A as a therapeutical regimen.

Splenomegaly in relation to Schistosoma mansoni egg counts: a population based study

A cross: sectional survey on schistosomiasis was done in Comercinho (Minas Gerais State, Brazil), a town with 1474 inhabitants. Stool (Kato-Katz method) and physical examinations were done on 90% of the population and on 84% of the individuals over 2 years of age, respectively. The ecological and individual (case-control) analysis were used to investigate the relation between splenomegaly and S. mansoni egg counts in different age groups. In the ecological analysis there was a clearly correspondence between higher geometric mean of eggs and higher percentage of splenomegaly in the age groups 5-9 and 10-12 years. In the individual analysis it was found that only in the youngest individuals (5-8 or 5-9 years old) the splenomegaly was related with higher mean egg counts in the feces, having been a tendency to the decrease of excretion of eggs in patients with splenomegaly as the age increased. These results strongly suggest that the ecological data are' better indicator of the severity of schistosomiasis in endemic areas, as the decrease of the egg excretion in patients with splenomegaly may be a confounding variable for the individual analysis.

Water-contact patterns and schistosoma mansoni infection in a rural community in northeast Brazil

We evaluated the influence of water-related human activities, contaminative behaviour, house location, education and socio-economic status on endemic Schistosoma mansoni infection. The study was conducted in a hilry non-irrigated area of rural northeast Brazil amongst a defined population of subsistence farmers, of whom 93% were infected by age 20. The area was mapped, water bodies were surveyed, and a detailed questionnaire was performed on each household. Infection was assessed by duplicate stool examinations using the sensitive Bell technique to quantify egg excretion. For each household, and index of intensity of infection was computed by grouping individual log-transformed egg counts as an age-sex adjusted Z score. Few households had a sanitary installation or a domestic water supply. However, neither water-contact nor contaminative behavior were indiscriminate. The people made considerable effort to defaecate far from a water source, to obtain household drinking water from the cleanest source, and to bathe only at certain sites where privacy is assured. Land ownership and literacy correlated poorly with the household index of intensity of infection. The key influence on infection status was the relative location of the house and snail-free or snail colonized water sources. In this area, a safe domestic water supply is the critical input needed to achieve definitive control of endemic Schistosomiasis.

Efficacy of oxamniquine, praziquantel and a combination of both drugs in schistosomiasis mansoni in Brazil

A randomized clinical trial was carried out to compare the efficacy of a low-dosage combination of oxamniquine (7.5 mg/kg) plus praziquantel (20 mg/kg) against either agent, oxamniquine (15 mg/kg) or praziquantel (40 mg/kg) alone, in the treatment of schistosomiasis mansoni in the Brazilian north-east. The drugs were randomly administered per os to 91 patients. Six and twelve months after treatment 89% of those admitted to the trial were reexamined by Kato-Katz method (ten slides) and MIF technique (one gram of stool) The achieved cure rates, as defined by absence of S. mansoni eggs in the faeces of individual patients at all points during the parasitological follow-up, were 81.8%, 81.2% and 67.6% for praziquantel, oxamniquine and the combination respectively. The reduction of eggs excretion in non cured patients six months after therapy ranged from 93.8-96.8% with praziquantel, 32.5-97% with oxamniquine and 76.9-99.5% with the combination. It is concluded that, at the used dosages, the three therapeutical regimens give similar and satisfactory results in the treatment of uncomplicated S. mansoni infection in Brazil.

Epidemiology of Schistosoma mansoni infection in a low-endemic area in Brazil: clinical and nutritional characteristics

A cross-sectional case-control study designed to evaluate the role of malnutrition in the association between the intensity of Schistosoma mansoni infection and clinical schistosomiasis, was conducted in an area with both low frequency of infection and low morbidity of schistosomiasis in Brazil. Cases (256) were patients with a positive stool examination for S. mansoni; their geometrical mean number of eggs/gram of feces was 90. Controls (256) were a random sample of the negative participants paired to the cases by age, sex and length of residence in the area. The clinical signs and symptoms found to be associated with S. mansoni infection, comparing cases and controls, were blood in stools and presence of a palpable liver. A linear trend in the relative odds of these signs and symptoms with increasing levels of infection was detected. Adjusting by the level of egg excretion, the existence of an interaction between palpable liver and ethnic group (white) was suggested. No differences in the nutritional status of infected and non-infected participants were found.

Serological, electrophoretic and biological properties of Fasciola hepatica antigens

Fasciola hepatica somatic antigen, its partially purified fractions and excretion-secretion products were investigated as to serological, electrophoretic and biological properties. In a Sephadex G-100 column (SG-100), Fasciola hepatica total antigen (FhTA) gave 5 fractions, and SDS-PAGE analysis showed they were glycoproteins ranging from 14 to 94 kDa molecular weight (MW). When these fractions were analyzed by enzyme linked immunotransfer blot (EITB) and immunodiffusion in gel (ID) with serum from immunized rats with FhTA, the presence of different antigenic components was revealed. In the SDS-PAGE of excretor-secretor antigen (ESA), it was possible to observe peptides from 12 to 22 kDa, which were also present in FhTA. When the FhTA, its fractions and the ESA were analyzed by EITB with the immune rat serum (IRS), it was observed that only some fractions of the SG-100 shared antigens with the FhTA and ESA. Moreover, DTH and ITH responses were studied in FhTA immunized rats challenged with these different antigen components, revealing that the protein/carbohydrate ratio is important for inducing DTH response. The ESA was the most active component in the DTH and ITH response.

Oogram studies in mice infected with Schistosoma mansoni and treated with dexamethasone

Mice infected with about 90 cercariae of Schistosoma mansoni (LE strain) were treated during five consecutive days with dexamethasone (50 mg/Kg, subcutaneously), starting on the 42th day of infection. Groups of five mice were then daily sacrificed from the first day after onset of treatment until the first day after. The perfusion of the portal system was performed and a piece of the intestine was processed for qualitative and quantitative oograms. This treatment carries to larger numbers of eggs in the tissues of treated mice, when compared with untreated groups. No changes were observed in the kinetics of oviposition, as all stages of viable eggs were observed in the tissues of treated and control mice. These data reinforce the hypothesis of a partial blockade of the egg excretion in immunossupressed mice.

Usefulness of the detection of Toxoplasma gondii antigens in AIDS patients

Toxoplasmic encephalitis (TE) is a mayor cause of central nervous system infection in patients with acquired immunodeficiency syndrome (AIDS). Toxoplasma antibodies were detected in 56 of 79 patients with AIDS (71%), in the present study. Fourteen out of 57 seropositive patients developed TF (25%) and had Toxoplasma gondii antigen detected in their urine. For this, most of them received an effective therapy, with the subsequent disappearance of the symptoms and discontinuity of excretion of the T. gondii antigens. Our results suggest that the monitoring of T. gondii antigen in the urine of AIDS patients may be useful to decide on the proper time for therapy, as well as to avoid the beginning of neurologic signs in these patients.

Persistence of specific antibody response in different experimental infections of mice with Toxocara canis larvae

Anti-Toxocara antibody production and persistence were studied in experimental infections of BALB/c mice, according to three different schedules: Group I (GI) - 25 mice infected with 200 T. canis eggs in a single dose; Group II (GII) 25 mice infected with 150 T. canis eggs given in three occasions, 50 in the 1st, 50 in the 5th and 50 in the 8th days; Group III (GIII) - 25 mice also infected with 150 T. canis eggs, in three 50 eggs portions given in the 1st, 14th and 28th days. A 15 mice control group (GIV) was maintained without infection. In the 30th, 50th, 60th, 75th, 105th and 180th post-infection days three mice of the GI, GII and GIII groups and two mice of the control group had been sacrificed and exsanguinated for sera obtention. In the 360th day the remainder mice of the four groups were, in the same way, killed and processed. The obtained sera were searched for the presence of anti-Toxocara antibodies by an ELISA technique, using T. canis larvae excretion-secretion antigen. In the GI and GII, but not in the GIII, anti-Toxocara antibodies had been found, at least, up to the 180th post-infection day. The GIII only showed anti-Toxocara antibodies, at significant level, in the 30th post-infection day.

Cytomegalovirus infection in a day-care center in the municipality of São Paulo

The prevalence of antibodies against cytomegalovirus (CMV) and the incidence of CMV infection were tested in 98 children aged 5 to 36 months who attended the day-care center of a University hospital in São Paulo. At the beginning of the study the overall prevalence of anti-CMV IgG antibodies was 44% (43/98). Saliva and/or urine samples were obtained from 38 of the 43 children that were seropositive at the beginning of the study for isolation of the virus, and 52.6% of these children were found to excrete CMV in one of the two materials. Among the 37 children that were initially seronegative from whom it was possible to obtain a new blood sample 6 to 12 months later, 22 (59.5%) presented seroconversion. The rate of viral excretion through urine or saliva from the children that seroconverted was 50%. These results indicate that CMV infection is frequent and occurs early among the children who attend this day-care center. However, controlled studies using molecular epidemiology techniques are needed to define more precisely the role of day-care centers in CMV dissemination.

In vivo and in vitro Plasmodium falciparum Resistance to Chloroquine, Amodiaquine and Quinine in the Brazilian Amazon

In order to study the chemoresistance of Plasmodium falciparum to commonly used antimalarial drugs in Brazil the authors have studied ten patients with falciparum malaria, acquired in the Brazilian Amazon region. Patients were submitted to in vivo study of drug sensitivity, after chemotherapy with either 4-aminoquinolines (chloroquine or amodiaquine) or quinine. Adequate drug absorption was confirmed by standard urine excretion tests for antimalarials. Eight patients could be followed up to 28 days. Among these in vivo resistance (R I and R II responses) was seen in all patients who received 4-amino-quinolines. One patient treated with quinine exhibited a R III response. Peripheral blood samples of the same patients were submitted to in vitro microtests for sensitivity to antimalarials. Out of nine successful tests, resistance to chloroquine and amodiaquine was found in 100% and resistance to quinine in 11.11% of isolates. Probit analysis of log dose-response was used to determine effective concentrations EC50, EC90 and EC99 to the studied drugs. Good correlation between in vivo and in vitro results was seen in six patients. The results emphasize high levels of P. falciparum resistance to 4- aminoquinolines and suggest an increase in resistance to quinine in the Brazilian Amazon region, reinforcing the need for continuous monitoring of drug sensitivity to adequate chemotherapy according to the most efficacious drug regimens