Chemical and pharmacological investigation of Solanum species of Brazil: a search for solasodine and other potentially useful therapeutic agents

A systematic search for solasodine, an important staring material for the partial synthesis of steroidal hormones as well as other potentially bioactive constituents of various Solanum species of Brazil has been undertaken. Thus, the fruits of S. paludosum, S. asperum, S. sessiliforum and Solanum sp. were found to contain significant amounts of solasodine. The root bark of S. paludosum which showe durare like activity yelded tomatidenol and another yet unidentified alkaloid responsible for the biological activity. The fruits of S. asperum yelded a new spirosolane alkaloid, solaparnaine. The stem bark of S. pseudo-quina showed convulsive and exitatory activity from which (25S)-isosolafloridine was identified as the active principle. In addition, the latter alkaloid was also found to show antimicrobial activity.

Localized, diffuse, and aggregative-adhering Escherichia coli from infants with acute diarrhea and matched-controls

Of 126 infants under 2 years, enrolled in a study on the etiology of acute diarrhea in Recife, Brazil, we selected 37 from whom no recognized enteropathogens, except classic enteropathogenic Escherichia coli, were identified. For comparison, we also examined 37 matched-control infants without diarrhea seen at the same hospital setting. This paper had the purpose to determine the prevalence of localized, diffuse, and aggregative-adhering E. coli strains in both groups. Three to five fecal E. coli colonies, of each case and control, were tested individually for adherence to HeLa cells by using the one step 3-h incubation assay. Strains of E. coli showing localized adherence were found significantly more often in patients (37.8%) than in controls (13.5%), p < 0.02, and they were pratically confined to EPEC serovars 055:H-, 0111:H2, and 119:H6. In contrast, E. coli isolates exhibiting the diffuse or aggregative patterns of adherence were restricted to non-EPEC serogroups and were more frequently encountred among controls.

Schistosomiasis mansoni in three localities of western lowland of the state of Maranhão before and after mass treatments

A cross-sectional study for schistosomiasis was carried out in the localities of Aliança, Alegre and Coroatá (districts of Cururupu, São Bento and São João Batista, respectively) in the lowland of the state of Maranhão, after respectively 13, 11 and 4 mass treatments with oxamniquine in the period of ten years (1977-1987). The study included clinical and quantitative fecal examination, skin test for Shistosoma mansoni infection, evaluation of man-water contact of the total population (829 persons) in the three localities and other epidemiological investigations such as infection rate and dynamics of the snail population. After 13 mass treatments in Aliança, the prevalence of S. mansoni infection was reduced from 57.9% to 7.4%. In Coroatá with 11 mass treatments the prevalence fell from 69.2% to 12.8% and in Alegre, with only 4 mass treatments there was pratically no reduction in prevalence: 22.9% to 21%. After mass treatments the type II hepatointestinal clinical form was 10.8% in Aliança, 17.9% in Alegre and 18% in Coroatá. The hepatosplenic (type III) form was not seen in Aliança and Coroatá but unexplanably it was 7.6% in Alegre. There was no correlation between the egg load elimination and the clinical forms.

Parasitismo natural de bufalinos em Botucatu, SP, Brasil: III. Dinâmica do parasitismo gastro-intestinal em vacas e suas crias

Gastro-intestinal parasitism of 24 buffalo cows before parturition, and post-parturition, their infection and that of their respective calves during the following 30 weeks were studied. Willis, Hoffmann and whenever possible, the modified Gordon & Whitlock techniques were used for fecal examinations. Toxocara vitulorum eggs were the earliest forms encountered in calves feces, as follows: during the 1st week after birth, 58.33% of the calves were positive, and in the 4th week, 100% of these animals were positive. Eggs of Strongyloides sp were in the 1st week after birth in two of the calves and in the 5th week, all for them were positive. The next parasites to appear were the Coccidia of which oocysts were detected in the feces of two calves in the 2nd week after birth, and 58.33% of the calves were positive for these in the 3rd week, and in the 6th week, all calves shed oocysts in their feces. On the other hand, eggs of Strongylids were the last forms to appear in calves feces. However, despite their sporadic appearance in the feces, eggs of these parasites were observed continuously from the 11th week onwards, and at this point, the percentage of positive samples began to increase to reach its peak. Relatively to adult animals, eggs of T. vitulorum were observed in the feces of 11 cows, one or twice at most; eggs of Strongyloides sp were seen only once in the feces of four buffalo cows and eggs of Strongylids in 21 out of 24 cows. Oocysts of Coccidia were observed in 16 cows. Mechanisms of infestation of calves with these parasites are discussed.

Influence of the host related factors in the development of the hepatosplenic form of schistosomiasis mansoni

The frequency of hepatosplenomegaly in endemic areas is not proportional to the fecal ova count. This may be explained by epidemiological genetic. The occurrence of two or more cases of schistosomal hepatosplenomegaly in nuclear family is much higher than expected. The concentration is higher among siblings than it is among mothers and children of further and children. It is not significant between father and mother. If the mother, instead of the father has hepatosplenic schistosomiasis the relative risk for the child to acquire hepatosplenomegaly is at least five times (the maternal affect). The inbreeding is highler in the hepatosplenic than in the hepatointestinal patients. In some areas in Brazil the hepatosplenic form of the schistosomiasis mansoni occurs with much higher frequency in whites than in blacks. After treatment, reversion of hepatosplenic schistosomiasis occurs more frequently in non-whithers. It seems that the resistance of blacks to the hepatosplenic form of schistosomiasis may be related to the glyoxalase system , perhaps associated to another genetic marker. The hepatosplenic schistosomiasis is less frequent in longilineal individuals. In some areas the hepatosplenic form of schistosomiasis is more frequent in A blood group of ABO sistem. The family heredograms do not suggest a single mendelian inheritance, but probably a multifactorial and possibility poligenic one.

Cross-sectional and evolutive studies of schistosomiasis mansoni in untreated and mass treated endemic areas in the southeast and northeast of Brazil

Cross-sectional and evolutive studies on schistosomiasis mansoni were carried out before and after mass treatment in the endemic areas of Capitao Andrade and Padre Paraíso, state of Minas Gerais, Riachuelo, state of Sergipe, Alhandra, state of Paraíba, and Aliança, Alegre and Coroatá, lowland of the state of Maranhao, Brazil, in the last eighteen years. The studies included clinical and fecal examination by the Kato-Katz quantitative technique, skin testfor Schistosoma mansoni infection, evaluation of man-water contact and other epidemiological investigations such as infection rate and dynamic of the snail population. Results showed: (1) Higher prevalence of S. mansoni infection, greater egg load elimination and higher and earlier morbidity of the chronic froms of the disease in the southeast areas of Capitao Andrade and Padre Paraíso; (2) The incidence of hepatosplenic form is higher in some family clusters, in whites and mullattos in all the endemic areas but develop earlier in the southeast; (3) The prevalence and morbidity of schistosomiasis are decreasing both in the mass treated northeast and in the untreated southeast areas; (4) The mass treatment reduces rapidily the prevalence of the infection and the morbidity of the disease but can not control it because of the frequent reinfections due to the intensity of man-water contact.

The distribution of intestinal helminth infections in a rural village in Guatemala

Fecal egg count scores were used to investigate the distribution and abundance of intestinal helminths in the population of a rural village. Prevalences of the major helminths were 41% with Ascaris lumbricoides 60% with Trichuris trichiura and 50% with Necator americanus. All three parasites showed a highly aggregated distribution among hosts. Age/prevalence and age/intensity profiles were typical for both A. lumbricoides and T. trichiura with the highest worm burdens in the 50-10 year old children. For hookworm both prevalence and intensity curves were convex in shape with maximum infection levels in the 30-40 year old age class. Infected females had higher burdens of T. trichiura than infected males in all age classes of the population; there were no other effects of host gender. Analysis of associations between parasites within hosts revealed strong correlations between A. lumbricoides and T. lumbricoides and T. trichiura. Individuals with heavy infections of A. lumbricoides and T. trichiura showed highly significant aggregation within households. Associations between a variety of household features and heavy infections with A. lumbricoides and T. trichiura are described.

Use of a selective medium with potassium tellurite to follow intestinal colonization of hospitalized patients by drug-resistant Enterobacteriaceae

Nosocomial infections are a relevant factor in complicating the recovery of patients interned for even minor causes. In attempt to determine their origin it is crucial to consider that their origin is of an endogenous nature. Looking for an acessible expression of intestinal colonization we analyzed fecal samples from 3 separate groups of hospital patients collected after different lenghts of time. For practical reasons one group was studied prospectively and two other groups (patients hospitalized for up to 7 days and patients hospitalized for more than 7 days) were compared to one another. We looked for the emergence of tellurite resistance among Enterobacteriaceae using a selective medium. MacConkey potassium tellurite (MCPT). The frequence of prospectively studied patients with tellurite resistant strains was significantly greater after 7 days of hospitalization. For the two other groups, patients with more than 7 days of hospitalization showed a significant increase of bacterial species and of strains with new antimicrobial resistance markers. High molecular weigth plasmids were detected in some of these strains. These data show that the MCPT medium is a useful tool for the investigation of bowel colonization in hospitalized patients by drug-resistant Enterobacteriaceae.

Intestinal protein absorption in malnourished mice with acute schistosomiasis mansoni

Intestinal protein absorption was studied in undernourished albino Swiss mice with acute schistosomiasis mansoni. Undernutrition was induced by feeding mice with the Regional Basic Diet (RBD) ingested by human populations in Northeast Brazil, an experimental model previously developed in our laboratory. Weaning mice were infected with 40 cercariae and compared to undernourished non-infected mice and/or to infected mice fed a balanced control diet. Apparent and True Protein Absorption Coefficients were determined by nitrogen balance during five consecutive days ending at the 63rd day of the trial (acute phase of murine schistosomiasis). Fecal metabolic nitrogen (FMN) was determined after administration of a non-protein diet and was also calculated through linear regression. Our results showed a reduced protein absorption in non-infected RBD-fed mice as compared to mice fed a casein control diet. Infection with Schistosoma mansoni had apparently no effect on intestinal protein absorption in well-nourished mice. However, infection seemed to interfere with protein absorption in under-nourished animals, since the lowest absorption ratios have been detected among RBD-fed infected mice. A brief discussion is made on the advantages of using the method of linear regression for the determination of FMN.

Schistosomiasis mansoni in the region of the Triângulo Mineiro, State of Minas Gerais, Brazil

In order to reevaluate the possible presence of schistosomiasis mansoni in the Triângulo Mineiro, one of the areas of the State of Minas Gerais where this parasite is not commonly found, malacological survey and fecal examinations were undertaken in the region between October 1990 and June 1992. A sample of 7,032 1st grade school children from 29 counties had their feces examined using the Kato-Katz method. Amongst the children examined, two from Planura and one from each countie of Capinópolis, Conceição das Alagoas, Uberaba, Uberlândia, Prata and Gurinhatã were positive for Schistosoma mansoni. None of the children were identified as being autoctonous cases. In the malacological survey, 5,406 planorbid snails were examined. The specimens were identified morphologically and examined for S. mansoni by squashing between glass plates. The species were identified as Biomphalaria tenagophila in three counties, as B. straminea in ten and B. intermedia in 16. No snails were found in eight other counties studies. The snails were found to be negative for S. mansoni. The presence of intermediate hosts for S. mansoni, associated with parasitized individuals emphasizes the necessity of epidemiological surveillance for schistosomiasis in the region of Triângulo in the State of Minas Gerais.

Intratypic differentiation of polioviruses isolated from suspected cases of poliomyelitis in Brazil during the period of 1990 to 1993

This study analyzed 3129 fecal samples derived from 1626 patients with sudden onset acute flaccid paralysis clinically compatible with poliomyelitis. The samples were collected in the period ranging from January 1990 to September 1993 in all regions of Brazil. Among the 1626 cases studied, 196 had isolation of poliovirus. Nevertheless, it was observed that some factors influenced the isolation rate and the intratypic characterization of these polioviruses. No cases of acute flaccid paralysis has been found to be etiologically related with wild polioviruses.

Cryptosporidium sp. in children suffering from acute diarrhea at Uberlândia City, State of Minas Gerais, Brazil

This study's objective was to search for Cryptosporidium sp. in diarrheic feces from children aged zero to 12 years and cared for at medical units within Universidade Federal de Uberlândia or at a private practice in Uberlândia, State of Minas Gerais, Brazil, from September 1992 to August 1993. Three fecal samples preserved in 10% formalin, were collected from 94 children. Oocyst concentration was performed through Ritchie's (modified) method and staining of fecal smears for each sample (total of 1128 slides) was done by the "Safranin/Methylene Blue" and the "Kinyoun (modified)" techniques. The Hoffmann, Pons & Janer method was also employed to look for other enteroparasites. From 94 children, 4.26% excreted fecal Cryptosporidium oocysts. The infection seemed to vary according to age: 5.08% of patients aged zero to two years old; 33.33% of those aging eight to ten years (P>0.05). Cryptosporidium appeared in November, December and March, during the rainy season. 20.21% of the children harbored at least one enteroparasite different from Cryptosporidium, mainly Giardia intestinalis (12.77%). From Cryptosporidium infected patients, two had only this kind, another harbored Giardia intestinalis; the last one hosted Strongyloides stercoralis.

Age-related worm load and worm fecundity patterns in human populations, as indicated by schistosome circulating antigens

Recently, our group determined the relationship between serum CAA levels and fecal egg counts in two foci with very intense Schistosoma mansoni transmission: Maniema (Zaire), an area endemic for S. mansoni since several decades, and Ndombo (Senegal), where transmission has only been established since a few years. The objective was to study and compare age-related worm load and worm fecundity patterns in these two different endemic settings. Here, we will summarize the most important findings and conclusions of this study.

IgM antibodies to Schistosoma mansoni gut-associated antigens for the study of schistosomiasis transmission in Ribeirão Pires, São Paulo

The potential of an immunofluorescence test for detection of IgM antibodies against Schistosoma mansoni gut-associated antigens (IgM-IFT) was evaluated as a tool for studying aspects related to the schistosomiasis transmission in Ribeirão Pires, in the metropolitan area of the capital of the State of São Paulo, Brazil. Children from a school with about 400 students, 6 to 18 years, were followed-up for two years. In the five surveys, carried out at 6-month intervals, from October 92 to October 94, serological (IgM-IFT) prevalence indices of 5.3%, 5.8%, 6.2%, 2.9% and 3.3% were obtained. These indices were 7 to 10 times higher than the parasitological prevalence indices of 0.5%, 0.5%, 0.7%, 0.4% and 0% determined by the Kato-Katz method. Seroconversion from IFT negative to positive was indicating possible newly acquired S. mansoni infection in three children. But confirmation of infection by fecal examination was possible in only one child. The IgM-IFT can constitute a valuable tool for the improvement of the vigilance program in low endemic areas for schistosomiasis, better characterizing the S. mansoni transmission in such areas.

Immunofluorescence test on Schistosoma mansoni worm paraffin sections (IgM-IFT) for the study of schistosomiasis transmission in Campinas, São Paulo, Brazil

The detection of IgM antibodies for Schistosoma mansoni using gut-associated antigens (IgM-IFT) was compared to the parasitological Kato-Katz method for study of the transmission of schistosomiasis in an urban area in Campinas. About 400 schoolchildren whose ages ranged from 6 to 18 years, were observed for a period of two years. Blood samples on filter paper and fecal samples were collected, at intervals of six months. Serological (IgM-IFT) prevalence rates of 1.2%, 4.3%, 3.6%, 2.9% and 3.4% were obtained in five surveys carried out. S. mansoni eggs were detected in only one child out of the 225 children (0.4%) who were submitted to the Kato-Katz method (three slides for each fecal sample) in the 1st survey. Sixty eight children who submitted five blood samples, one for each survey, were found IFT negative throughout the study. No child was found to be IFT positive in all five surveys, and only four children showed IFT positive results in at least four surveys. Seroconversion from IFT negative to positive was observed from the 1st to the 2nd survey in six chidren, from the 2nd to the 3rd survey in three children, from the 3rd to the 4th survey in four children, and from the 4th to the 5th survey in two cases. However, confirmation of S. mansoni infection using the fecal examination was not possible in any of the cases. Also, in most of them the IFT result oscillated from negative to positive and vice versa. Our data implied that recent transmission of schistosomiasis in the study area was not possible.