Genetic diversity and population structure of different varieties of Morada Nova hair sheep from Brazil.

The aim of this study was to analyze genetic diversity and population structure among varieties of White (N = 40), Red (N = 32), and Black (N = 31) Morada Nova hair sheep from flocks in the northeastern Brazilian semiarid region. Fifteen nuclear microsatellite markers and two regions of mitochondrial DNA were used. The intra-population analysis demonstrated that the White variety had higher diversity, while the Red variety had the lowest values. The Bayesian analysis to assess the genetic population structure allowed differentiation between White, Red, and Black varieties, and revealed a tendency towards sub-structuring in the White variety flocks from the States of Ceará and Paraíba. The results of analyses of molecular variance showed that the greatest genetic structure was found when comparing flocks rather than varieties (8.59 vs 6.64% of the total variation, P < 0.001). Based on genetic distance, Dtl, both the dendrogram analysis and the principal coordinate analysis showed the formation of two main groups: one composed of White and another of Black and Red individuals. Five and two haplotypes were found for the D-loop region and the ND5 gene, respectively. A haplotype unique to the Red variety was found in the D-loop region and a variety haplotype unique to the Black variety was found in the ND5 gene; however, these frequencies were low and therefore require further validation. These results support the existence of substantial differences between the Red and White varieties and should be used as separate genetic resources and to improve conservation programs.

Expression of antisense to integrin subunit beta 3 inhibits microvascular endothelial cell capillary tube formation in fibrin.

alpha(v)beta(3) antagonists are potent angiogenesis inhibitors, and several different classes of inhibitors have been developed, including monoclonal antibodies, synthetic peptides, and small organic molecules. However, each class of inhibitor works by the same principal, by blocking the binding of ligands to alpha(v)beta(3). In an effort to develop an alpha(v)beta(3) inhibitor that down-regulates the actual level of alpha(v)beta(3), we developed an antisense strategy to inhibit alpha(v)beta(3) expression in vitro. beta(3) antisense expressed in endothelial cells specifically down-regulated alpha(v)beta(3) and inhibited capillary tube formation, with the extent of down-regulation correlating with the extent of tube formation inhibition. This inhibition was matrix-specific, since tube formation was not inhibited in Matrigel. These findings support the notion that alpha(v)beta(3) is required for an essential step of angiogenesis in fibrin, namely capillary tube formation. These results suggest that pseudogenetic inhibition of beta(3) integrins using antisense techniques may ultimately provide a therapeutic means to inhibit angiogenesis in vivo.

A site-directed chromosomal translocation induced in embryonic stem cells by Cre-loxP recombination.

We have developed a strategy for chromosome engineering in embryonic stem (ES) cells that relies on sequential gene targeting and Cre-loxP site-specific recombination. Gene targeting was first used to integrate loxP sites at the desired positions in the genome. Transient expression of Cre recombinase was then used to mediate the chromosomal rearrangement. A genetic selection relying on reconstruction of a selectable marker from sequences co-integrated with the loxP sites allowed detection of cells containing the Cre-mediated rearrangement. A programmed translocation between the c-myc and immunoglobulin heavy chain genes on chromosomes 15 and 12 was created by this method. This strategy will allow the design of a variety of chromosome rearrangements that can be selected and verified in ES cells or activated in ES cell-derived mice.

Acute respiratory viral infections in ambulatory children of urban northeast Brazil.

The morbidity of acute respiratory infections in young children and the role of respiratory viruses were evaluated in a 29-month household-based study in an impoverished urban population in Fortaleza, Brazil; subjects were 175 children less than 5 years of age in 63 families. Home visits were conducted three times weekly during which staff recorded the presence of respiratory and systemic symptoms and collected upper respiratory tract samples for viral isolation. A large and sustained burden of respiratory illness was observed, and respiratory viruses were isolated in 35% of the samples collected. Of the isolates, 45.6% were rhinoviruses, 16% parainfluenza viruses, 15.8% enteroviruses, 9.9% adenoviruses, 7.0% herpes simplex viruses, and 5.7% influenza viruses. The results indicate that poor children in northeast Brazil have a high prevalence of respiratory illness and that rhinovirus is the most frequent respiratory virus.

[Seroprevalence and risk factors for hepatitis B virus infection by AgHBs and anti-HBs markers in prisoners and prime blood donors]. / Soroprevalência e fatores de risco para a infecção pelo vírus da hepatite B pelos marcadores AgHBs e anti-HBs em prisioneiros e primodoadores de sangue.

Two cross-sectional surveys on hepatitis B virus (HBV) infection were carried out among 1,033 volunteer first-time blood donors in five blood banks (3 private, 2 public) and among 201 prisoners in the Penitentiary Center of Industrial Activity, in Goiania, Central Brazil, between June 1988 and February 1989. Those surveys were part of a major study designed to estimate seroprevalence of HBsAg and anti-HBsAg markers by ELISA test, and to study risk factors associated with seropositivity. The presence of any serum marker was considered as previous exposure to HBV. A standard questionnaire was applied to both populations to evaluate previous blood transfusion, number of sexual partners, homo/bisexual activity, history of sexually transmitted diseases, drug abusers, use of parenteral medicine, acupuncture, tattooing and VDRL seropositivity. Seroprevalence varied from 12.8% to 26.4% in blood donors and prisoners, respectively, (p less than 0.05) and increased with age (X2 trend=14.0 p less than 0.05%). Prisoners had higher percentages of all risk factors investigated than blood donors, with the exception of number of sexual partners. Among all risk factors studied, age, imprisonment and tattooing were statistically associated with seropositivity, even after multivariate analysis controlling for age and reclusion. The paper discusses the methodologic issues related to this epidemiologic investigation.

[Seroprevalence and risk factors for syphilis in prisoners in Goiás, Brazil]. / Soroprevalência e fatores de risco para sífilis em população carcerária de Goiás.

A cross-sectional survey was carried-out among 299 prisoners in the Penitentiary Center of Industrial Activity of Goiás (CEPAIGO), to determine the seroprevalence to T. pallidum and to identify risk factors associated to seropositivity. The seropositivity criterion was a positive VDRL test at any titer. A questionnaire was applied to evaluate the following risk factors: time of imprisonment, clinical evidence of sexually transmitted diseases (STD), history of syphilis or others STD, homo/bisexuality and number of sexual partners. The positive (PPV) and negative (NPV) predictive values of the history of syphilis were calculated. Seroprevalence of 18.4% was found and no difference was detected in the different age groups. The PPV of history of syphilis was 26% indicating that 74% of the individuals who have reported syphilis in the past presented a negative VDRL test. Among all the risk factors studied, homo/bisexuality was the only one with statistically significant association with seropositivity (relative risks 5.7-95% CL1.2-26, p = 0.03). The paper discusses the methodological problems related with the investigation.

Brazilian popular healers as effective promoters of oral rehydration therapy (ORT) and related child survival strategies.

PIP: In Ceara State in northeastern Brazil in 1986 infant mortality reached 110-139 per 1000 live births, and 50% of those deaths were due to diarrhea and dehydration. Diarrheal deaths can be prevented by oral rehydration therapy (ORT), which replaces lost fluids and electrolytes with oral rehydration salts (ORS) and water. ORT was known in the 1830s, but only in the 1960s was the importance of sugar, which increases the body's ability to absorb fluid some 25 times, realized. In northeastern Brazil access to ORT has been severely limited by poverty, official incompetence, and bureaucratic restrictions. In 1984 a 2-year research project was initiated in the village of Pacatuba to test the theory that mobilizing and training popular healers in ORT would 1) increase awareness and use of ORS, 2) promote continued feeding during diarrhea, 3) increase breast feeding, and 4) reduce the use of costly and nonindicated drugs. 46 popular healers, including rezadeiras and oradores (prayers), Umbandistas (priests), espiritas (mediums), an herbalist, and a lay doctor, were recruited and trained. Most of these people practiced a mixture of folk medicine and religion and were highly respected in the community. For purposes of survey, Pacatuba was divided into 3 groups, each containing houses at 4 different income levels. The mothers in 204 Group 1 homes were interviewed concerning ORT and diarrhea-related knowledge before intervention, and 226 households in Group 2 were interviewed after intervention. The healers were taught the basic biomedical concept of rehydration and how to mix the ORS -- 7 bottle cap-fulls of sugar and 1 of salt in a liter of unsweetened traditional tea. The healers were also taught how to use the World Health Organization's (WHO) ORS packets (2% glucose, 90 mmol/1 of sodium chloride, 1.5 gm potassium chloride, and 2.9 gm sodium bicarbonate) for cases of moderate to severe dehydration. In addition, the healers were taught the 5 basic health messages: give ORS-tea for diarrhea and dehydration (or any similar folk illness, such as evil eye, fallen fontanelle), continue feeding, encourage breast feeding, eliminate drugs, and ask people to seek the healer quickly at the onset of diarrhea. The healers continued to perform all the popular rites and prayers traditionally associated with curing diarrhea. The healers distributed approximately 7400 liters of ORS-tea in 12 months at a unit cost of 48 cents (US). A post-intervention survey of diarrhea-related knowledge was then carried out among the 226 Group 2 households. Before the intervention 2.9% of the mothers knew about ORS; 71.2% did afterward. All of the healers demonstrated that they knew exactly how to mix the ORS-tea. Knowledge of the WHO packets also increased. The number of mothers who continued feeding their children during diarrhea increased to 92%. Following the introduction of the ORS-tea, purchases of the more costly WHO packets and other commercial medications and antibiotics fell off significantly. The people's belief in folk etiologies remained unchanged, showing that traditional healers can be successfully integrated into an effective health care program. The success rate of the ORT program in Pacatuba, carried out entirely by word of mouth, compares favorably with expensive mass media campaigns other places.^ieng

Feasibility and efficacy of in-home water chlorination in rural North-eastern Brazil.

The purpose of this study was to assess the feasibility, acceptability and effect of an in-home water chlorination programme in a rural village. Previous studies at this site showed high levels of faecal coliforms in household water, high diarrhoea rates in children, and enterotoxigenic Escherichia coli and rotaviruses were the most common pathogens isolated from patients. Household water came from a pond and was stored in clay pots. No homes had sanitary facilities. A blind, cross-over trial of treatment of household water with inexpensive hypochlorite by a community health worker was carried out over 18 weeks among 20 families. Water in the clay pots was sampled serially, and symptom surveillance was done by medical students. The programme was generally acceptable to the villagers and no change in water use patterns were apparent. The mean faecal coliform level in the chlorinated water was significantly less than in the placebo treated samples (70 vs 16000 organisms/dl, P less than 0.001). People living in houses receiving placebo treatment had a mean of 11.2 days of diarrhoea per year, and the highest rate of 36.7 was among children less than 2 years old. Diarrhoea rates were not significantly different among the participants while exposed to water treated with hypochlorite. We conclude that a low-cost programme of this type, which utilizes community resources, is logistically feasible, appears to be culturally acceptable in this setting, and can result in a marked reduction in water contamination. The lack of effect on diarrhoea rates suggests that improvement in water quality may affect morbidity only when other variables relating to faecal-oral agent transmission are ameliorated at the same time.

Prospective study of diarrheal illnesses in northeastern Brazil: patterns of disease, nutritional impact, etiologies, and risk factors.

Diarrhea is a leading cause of death in tropical countries. One of the highest childhood mortalities is in northeastern Brazil, where little is known about the morbidity, etiology, and risk factors of diarrhea. Prospective village surveillance over 30 months revealed diarrhea attack rates of more than seven episodes per child-year at six to 11 months of age among the children of the poorest families. Other risk factors included early weaning and the lack of toilets. Diarrhea led to weight loss and stunted growth. Enterotoxigenic Escherichia coli and rotaviruses were the most common pathogens, accounting for 21% and 19% of cases, respectively, followed by Shigella species (8.0%), Campylobacter jejuni (7.5%), Giardia species (6.7%), Strongyloides species (5.3%), and enteropathogenic E coli serotypes (4.6%). Most (84%) enterotoxigenic E coli were isolated during the rainy season of October to March (P less than 0.03), whereas 71% of rotaviral illnesses occurred during the drier months of June to October (P less than 0.03). In the present study, the early occurrence and nutritional impact of diarrhea and weaning, as well as the major etiologic agents of diarrhea and their different seasonal patterns have been defined for this region in which life-threatening diarrhea is endemic.

Surface electrical charge of bloodstream trypomastigotes of Trypanosoma cruzi strains.

Bloodstream trypomastigotes of some Trypanosoma cruzi strains were processed through DEAE-cellulose columns under standardized conditions. The results obtained suggest mainly that these strains present different surface charges, that there are subpopulations of bloodstream trypomastigotes as regards electrical charges and that the broad forms are less negative than the slender ones.