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Biomedical subjects

R M Martins

Publications and source records attributed to R M Martins.

At least 19 recordsLinked to original sources
PubMed2001

16alpha,17alpha-Epoxy-20-oxopregn-5-en-3beta-yl acetate.

The title compound, C23H32O4, has a 3beta configuration, with the epoxy O atom at 16alpha,17alpha. Rings A and C have slightly distorted chair conformations. Because of the presence of the C5=C6 double bond, ring B assumes an 8beta,9alpha-half-chair conformation slightly distorted towards an 8beta-sofa. Ring D has a conformation close to a 14alpha-envelope. The acetoxy and acetyl substituents are twisted with respect to the average molecular plane of the steroid. The conformation of the molecule is compared with that given by a quantum chemistry calculation using the RHF-AM1 (RHF = Roothaan Hartree-Fock) Hamiltonian model. Cohesion of the crystal can be attributed to van der Waals interactions and weak intermolecular C-H.O interactions, which link the molecules head-to-tail along [101].

Crystallography, X-Ray↗
PubMed2001

Immunogenicity of a recombinant hepatitis B vaccine (Euvax-B) in haemodialysis patients and staff.

Hepatitis B vaccine is the most effective strategy for preventing the transmission of hepatitis B virus (HBV) in haemodialysis centers. Nevertheless, lower vaccine responses have been reported in haemodialysis patients as compared with healthy subjects. This study examines the response to Euvax-B in Brazilian haemodialysis patients and staff. A total of 102 eligible patients (n = 42) and staff members (n = 60) consented to be studied. Patients were immunized intramuscularly with four doses of 40 microg of Euvax-B vaccine at 0, 1, 2 and 6 months. In staff members, the vaccine was administered in three doses of 20 microg at 0, 1, and 6 months. Post-vaccine samples were taken from all subjects I month after each dose. The vaccine response was determined by measuring antibody to the hepatitis B surface antigen (anti-HBs) levels using ELISA. Subjects with anti-HBs titres equal to or higher than 10 UI/L were considered immune protected. Of the haemodialysis patients who received four doses of hepatitis B vaccine, 89.5% responded to Euvax-B vaccine. The geometric mean of anti-HBs titres was 322.8 IU/L (95% CI: 317.7-328). Among staff members, 93.3% reached anti-HBs protective titres after the third vaccine dose. The geometric mean of anti-HBs titres was 2,209 IU/L (Cl: 2,198-2,219). Age, male gender and body mass index were not associated with vaccine response in either group. This study showed a good immunogenicity response to Euvax-B in haemodialysis patients and staff.

Adolescent↗
PubMed2001

Hepatitis C prevalence and risk factors in hemodialysis patients in Central Brazil: a survey by polymerase chain reaction and serological methods.

An hemodialysis population in Central Brazil was screened by polymerase chain reaction (PCR) and serological methods to assess the prevalence of hepatitis C virus (HCV) infection and to investigate associated risk factors. All hemodialysis patients (n=428) were interviewed in eight dialysis units in Goiânia city. Blood samples were collected and serum samples screened for anti-HCV antibodies by an enzyme-linked immunosorbent assay (ELISA). Positive samples were retested for confirmation with a line immunoassay (LIA). All samples were also tested for HCV RNA by the PCR. An overall prevalence of 46.7% (CI 95%: 42-51.5) was found, ranging from 20.7% (CI 95%: 8.8-38.1) to 90.4% (CI 95%: 79.9-96.4) depending on the dialysis unit. Of the 428 patients, 185 were found to be seropositive by ELISA, and 167 were confirmed positive by LIA, resulting in an anti-HCV prevalence of 39%. A total of 131 patients were HCV RNA-positive. HCV viremia was present in 63.5% of the anti-HCV-positive patients and in 10.3% of the anti-HCV-negative patients. Univariate analysis of risk factors showed that the number of previous blood transfusions, transfusion of blood before mandatory screening for anti-HCV, length of time on hemodialysis, and treatment in multiple units were associated with HCV positivity. However, multivariate analysis revealed that blood transfusion before screening for anti-HCV and length of time on hemodialysis were significantly associated with HCV infection in this population. These data suggest that nosocomial transmission may play a role in the spread of HCV in the dialysis units studied. In addition to anti-HCV screening, HCV RNA detection is necessary for the diagnosis of HCV infection in hemodialysis patients.

Adolescent↗
PubMed2001

Genotyping of group A rotavirus samples from Brazilian children by probe hybridization.

The G genotyping of 74 group A rotavirus samples was done by RNA-DNA hybridization (dot-blot) using oligonucleotide probes for the VP7 gene region of the human rotavirus serotypes/genotypes 1, 2, 3 and 4. Thirty-one samples could be genotyped by dot-blot showing the following results: G1 = 16, G4 = 6, G3 = 5, and G2 = 4. The data show circulation of genotypes G1-G4 and the predominance of G1. The knowledge of genotypes provides important information concerning rotavirus circulation in Central Brazil.

Brazil↗
PubMed1999

Hepatitis B virus: genotypes and subtypes in Brazilian hemodialysis patients.

There are no data concerning the genotypic analysis of hepatitis B virus (HBV) infection in Brazilian dialysis centers. Serum samples from all hemodialysis patients (n = 282) in Goiânia City, Central Brazil, were tested for hepatitis B surface antigen (HBsAg). An overall prevalence of 12.0% was found, ranging from 0 to 33.3% depending on dialysis centers. Positive samples (n = 34) were submitted to serological subtyping by monoclonal ELISA and HBV DNA detection by polymerase chain reaction (PCR). Among 30 PCR-positive samples, 26 were genotyped by use of the line probe assay technology (INNO-LiPA HBV, Innogenetics, Gent, Belgium). HBV genotypes A (50. 0%) and D (46.2%) were the most frequently found whereas genotype F (3.8%) was rare in this population. Serological subtypes adw2 (44. 1%) and ayw3 (41.2%) were dominant. By contrast, adw4 and ayw2 were found at a low frequency (2.9%). A correlation was observed in the distribution of genotypes and subtypes by dialysis center. Genotype D and subtype ayw3 were predominant in 2 hemodialysis centers whereas genotype A and subtype adw2 were predominant in the others. The findings of high HBsAg prevalence rates restricted to certain dialysis centers and the data obtained through genotyping and serological subtyping suggest HBV nosocomial transmission in these hemodialysis centers.

Adolescent↗
PubMed1999

[Varicella: clinical aspects and prevention]

OBJECTIVE: To present, in practical form and updated terms, the clinical aspects of the varicella and its prevention using either vaccination or isolation precautions. METHOD: Review of the literature using MEDLINE and LILACS referring to the last 10 years; presentation of the most recent aspects in the literature as well as reference to the author's professional experience in the area. RESULTS: Current aspects of the clinic and treatment of this disease are analyzed. The vaccine is examined in relation to the soroconversion and safety. The technique of application of the vaccine is presented, considering its indication for healthy children, adults, seniors and high risk patients. Among these, we consider those with leukemia, solid tumors, nephrotic syndrome, AIDS, and those transplanted. The application of the vaccine is analyzed in relation to contacts, personal in the health area and people in closed communities. Precautions, contraindication, production and types of vaccines are analyzed. The association and combination of vaccines, as well as their current indications are carefully discussed. As a nosocomial infection, varicella requires much attention due to its very easy dissemination. Recommended procedures are indicated for both hospitalized and contact cases of varicella or zoster. CONCLUSIONS: The appropriate knowledge of the clinic, treatment and preventive procedures in cases of varicella is mostly important for the pediatrician, especially with the introduction of its vaccine in our country.

Journal Article↗
PubMed1995

Short report: prevalence of hepatitis C viral antibody among Brazilian children, adolescents, and street youths.

The prevalence of hepatitis C antibodies (anti-HCV) was investigated in 1,378 central Brazilian children, students, and street youths (homeless adolescents without family links or adolescents working in poorly paid activities). Sera were tested with a second generation enzyme-linked immunosorbent assay, and positive samples were retested by a confirmatory assay (line immunoassay). All children attending day care centers were anti-HCV negative. Only one (0.2%) adolescent was positive in the student group. However, higher positivity was found in street youths; four (1.0%) living at home and three (3.0%) living in the streets and anti-HCV antibodies. Among these, the prevalence of anti-HCV increased significantly with age from 0% in the 9-12-year-old group to 6.9% in the 17-20-year-old group. Risk factors including blood transfusion, tattooing, intravenous drug use, and sexual intercourse with multiple partners were significantly associated with the presence of anti-HCV in street youths. These results indicate that apparently healthy children and adolescents attending day care centers or primary schools in central Brazil have a low exposure to HCV infection, but street youths in the same area are at risk for infection with this virus.

Adolescent↗
PubMed1994

Quality assurance of a diarrhoea control programme in northeastern Brazil.

In this study quality assurance methods were used in an evaluation of a programme for Control of Diarrhoeal Diseases (CDD) in northeastern Brazil. Seventy-eight randomly selected public primary care facilities in four states were assessed by trained surveyors. Problems observed in the facilities were lack of information on target population and coverage, lack of equipment to permit rehydration in the premises, and frequent unavailability of trained professionals. Health workers showed deficiencies in history taking, physical examination and knowledge on diarrhoea management. Many caretakers had difficulties in recalling information given to them in the health facilities. Eighty-four percent of the cases were treated with oral rehydration, but 90% were sent home immediately and not kept in the facilities to practice rehydration under guidance as recommended by the national CDD programme. An overuse of the medical treatment was observed. More than two-thirds of health professionals gave wrong indications for use of antibiotics. The study showed that oral rehydration therapy is well established in the government health services in the region but that the CDD programme needs to take early action to correct deficiencies in logistics, case management and health education.

Brazil↗
PubMed1991

Management of childhood diarrhoea at the household level: a population-based survey in north-east Brazil.

The management of childhood diarrhoea at the household level was studied in a population-based survey in four states in north-east Brazil. Of a representative sample of 6524 children under 5 years of age, 982 (15.1%) had diarrhoea on the day of the interview or had had diarrhoea at some time during the previous 15 days. A total of 66% of the children were not taken for treatment, while government health services were used by 14%, private doctors by 1%, and traditional healers (rezadeiras) by 24%. Oral rehydration therapy was given to 24.3% of the children as follows: solutions of oral rehydration salts (ORS) were received by 6.8%, salt-and-sugar solutions by 14.7%, and solutions of commercial ORS brands by 4.3%. Although 95% of the caretakers knew about rehydration solutions, only 18% prepared them correctly, the most common error being the use of insufficient water. Of the rehydration solutions used, 39% had a sodium concentration that was potentially dangerous (greater than 120 mmol/l), and 8% had a sodium concentration that was very low. Of those solutions prepared using ORS, 38% had too high a sodium concentration, while 14% of the salt-and-sugar solutions prepared using either the "scoop-and-pinch" approach or a plastic spoon were too concentrated. However, potentially the most dangerous were the salt-and-sugar solutions prepared using nonstandard recipes. More than half of these had an unacceptably high sodium concentration or osmolarity.

Brazil↗
PubMed1989

Mill Hill strain of parainfluenza 1 virus is a potent human interferon inducer.

The interferon (IFN)-inducing capacities of the widely used Cantell strain of Sendai and the Mill Hill strain of parainfluenza 1 were compared. The Mill Hill strain proved to be a more potent inducer of IFN than the Cantell strain when tested in human peripheral blood leukocytes and amniotic membrane cultures. The Mill Hill strain did not produce defective particles readily, nor did these particles appear necessary for IFN induction. The Mill Hill strain of parainfluenza 1 virus appears superior to the Cantell strain of Sendai virus for the production of natural human IFN.

Amnion↗
PubMed1984

Frontofacionasal dysplasia: evidence for autosomal recessive inheritance.

We report on a 2-month-old girl whose parents are first cousins. The patient has severe craniofacial anomalies characterized by: encephalocele, hypertelorism, midface hypoplasia, hypoplasia of frontal bone on the left side, malformed left eye, absent inner eyelashes, irregular S-shaped palpebral fissures, deformed nostrils, hypoplastic right nasal wing and cleft lip, and clefts of premaxilla, palate and uvula. No other malformations were observed. This association of anomalies suggests the diagnosis of frontofacionasal dysplasia. Parental consanguinity suggests autosomal recessive inheritance.

Abnormalities, Multiple↗
PubMed1980

Familial occurrence of bifid femur and monodactylous ectrodactyly.

Two brothers each had one normal upper limb; one had tridactylous ectrodactyly of one hand with normal forearm bones; the other had monodactyly of one hand with absent ipsilateral ulna. Both had monodactyly of the feet, absence of the tibiae, and unilateral bifurcation of the femur. A sister of the paternal grandfather was purportedly similarly affected. Since her parents and the father and paternal grandfather of the affected boys were normal, the pattern of inheritance of the trait in this family is presently unclear.

Child, Preschool↗
PubMedDate not supplied

Anti-HCV related to HCV PCR and risk factors analysis in a blood donor population of central Brazil.

Data concerning HCV infection in Central Brazil are rare. Upon testing 2,350 voluntary blood donors from this region, we found anti-HCV prevalence rates of 2.2% by a second generation ELISA and 1.4% after confirmation by a line immunoassay. Antibodies against core, NS4, and NS5 antigens of HCV were detected in 81.8%, 72.7%, and 57.5%, respectively, of the positive samples in the line immunoassay. HCV viremia was present in 76.6% of the anti-HCV-positive blood donors. A relation was observed between PCR positivity and serum reactivity in recognizing different HCV antigens in the line immunoassay. The majority of the positive donors had history of previous parenteral exposure. While the combination of ALT > 50 IU/l and anti-HBc positivity do not appear to be good surrogate markers for HCV infection, the use of both ALT anti-HCV tests is indicated in the screening of Brazilian blood donors.

Adolescent↗
PubMedDate not supplied

Risk factors and prevalence of antibodies against hepatitis A virus (HAV) in children from day-care centers, in Goiania, Brazil.

A seroepidemiologic survey about hepatitis A virus (HAV) infection was carried out in a group comprising 310 children, ranging in age from 3 months to 9 years, from day-care centers, in Goiania, a middle sized city in the central region of Brazil. The biomarkers employed in the investigation of previous infection include total IgG and IgM anti-HAV antibodies, and for the detection of more recent infection, IgM anti-HAV antibodies were analyzed. The study was performed in 1991 and 1992. According to the results, 69.7% of the children presented total IgG/IgM anti-HAV antibodies, with 60% of the group in the age range of 1 to 3 years. Among 10 day-care centers analyzed, the prevalence of the biomarker IgM anti-HAV was 3.2%, with an uniform distribution of the cases in the group of children ranging in age from 1 to 4 years. Multivariate analysis was performed to investigate the sociodemographic factors that could influence the results. It was verified that the risk for the infection increased with the length of the attendance in the day-care centers, i.e., the risk for children with attendance of one year or more was 4.7 times higher, when compared with children with one month attendance (CI 95% 2.3-9.9). According to the results, hepatitis A is an endemic infection in day-care centers in the study area. The length of attendance in the day-care settings was demonstrated to be a risk factor for the HAV infection. Such findings suggest that if hepatitis A vaccination becomes available as a routine policy in our region, the target group should be children under one year. Moreover, those children should receive the vaccine before they start to attend the day-care centers.

Brazil↗