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Biomedical subjects

R Martinez

Publications and source records attributed to R Martinez.

At least 325 records · Page 18Linked to original sources
PubMedDate not supplied

Limitations of the MANOVA of statistical moments in bioequivalence trials of drugs with slow elimination rate: a study with spironolactone.

The capacity of the statistical moments for detecting bioavailability changes in bioequivalence studies of drugs with high disposition mean residence time (MRT) is analysed. Two bioavailability trials were carried out with spironolactone in which extent and rate of absorption were modified in a controlled way. The statistical analysis employed was a two-way MANOVA of statistical moments of the urinary excretion profiles of canrenone. The results indicate a loss in the sensitivity of MRT for detecting changes in absorption rate as drug elimination rate decreases.

Adult↗
PubMedDate not supplied

Congenital sacrococcygeal teratomas: effect of gestational age on size, morphologic pattern, ploidy, p53, and ret expression.

Prognosis of infants born with sacrococcygeal teratomas (SCTs) correlates with gestational age (GA). The survival rate after 30 weeks of gestation is 75%, compared to 7% before 30 weeks of gestation. Studies correlating GA with size, morphologic composition of teratomas, ploidy or expression of cell cycle control proteins such as p53, and ret [a tyrosine kinase receptor of the GDNF (glial cell line-derived neurotrophic factors)] receptor family may provide information explaining differences in survival. Seven SCTs (GA 21 to 41 weeks), ranging in size from 5 to 15 cm, were evaluated for morphologic composition. DNA ploidy was assessed in mature and immature neural elements. Immunohistochemical reactivity with monoclonal antibodies recognizing p53, and ret was quantitated and correlated with morphological pattern and GA. Relative size of teratomas to infants' weight and content of immature neural tissues correlated inversely with advancement of GA. Yolk sac tumor (YST) and immature tissues showed aneuploid cell populations. Nuclear p53 reactivity was apparent in the teratoma with YST in the microcystic patterns, the neuroectodermal rosettes, and the glandular patterns. Ret reactivity was seen in osteoclasts adjacent to bone formation surrounding developing teeth in an immature teratoma, and in rare mature neural cells of one SCT of 35 weeks GA. The rapid growth of SCT (GA <30 weeks) correlates with increase in immature neural tissues. Our study confirms aneuploidy in YST and suggests aneuploid populations within immature tissues. p53 accumulates in a variety of patterns of YST and may be seen in immature components of SCTs. To understand the possible role of ret, further studies comparing ret expression in immature human tissues are needed.

Aneuploidy↗
PubMedDate not supplied

Sylvatic yellow fever activity in Trinidad, 1988-1989.

Of a total of 18,068 mosquitoes (361 pools) collected in south-eastern Trinidad forests from December 1988 to May 1989, 47 species belonging to 14 genera were identified. Five yellow fever virus isolates were made from Haemagogus janthinomys and one from Sabethes chloropterus. All the other pools of mosquitoes examined were negative for the virus. The mosquito isolates were made in December and January. In addition, in late February and early March, 2 infected howler monkeys (Alouatta sp.) were detected. Since March, despite continued surveillance, no yellow fever virus has been detected in mosquitoes or monkeys. There has been no reported human infection.

Alouatta↗
PubMedDate not supplied

Role of the armadillo Dasypus novemcinctus in the epidemiology of paracoccidioidomycosis.

A study conducted in a rural area of Ibiá, State of Minas Gerais, Brazil, where Paracoccidioides brasiliensis was recently isolated from soil, sought to determine if the armadillo Dasypus novemcinctus developed paracoccidioidomycosis. Out of 21 armadillos captured in the area, one had a lung granuloma containing fungal cells attributable to those of P. brasiliensis. The present report presents the first histopathological evidence for the presence of this pathogen in the lungs of an armadillo. This finding permitted us to establish a linkage between the two species and to suggest that fungal infections of humans and of armadillos occur in the same agricultural and forest microenvironment that they share.

Animals↗
PubMedDate not supplied

Does a patient with hereditary spherocytosis qualify for preoperative autologous blood donation?

BACKGROUND: Hereditary spherocytosis (HS) is characterized by osmotically fragile spherocytic red cells (RBCs), mild to moderate hemolysis, and splenomegaly. Little is known about the safety of blood bank storage of HS RBCs. CASE REPORT: A 50-year-old man with mild autosomally dominant HS asked to make an autologous RBC deposit before his scheduled surgery. His RBCs were serially tested for osmotic fragility during 4 weeks of blood bank storage in CPD with adenine-saline. Aliquots of his fresh and 4-week-old RBCs were also labeled with 51Cr for measurement of in vivo survival. The osmotic fragility of the patient's fresh RBCs was normal, with 50-percent hemolysis at approximately 0.43-percent NaCl and a sigmoid lysis curve. Incubated osmotic fragility (24 hours at 37 degrees C) was abnormal, with 50-percent hemolysis at 0.64-percent NaCl. Median survival of his fresh 51Cr-labeled RBCs was moderately shortened at 17.5 days. Osmotic fragility increased during storage, with 50-percent lysis occurring at 0.58-percent and 0.62-percent NaCl after 2 and 4 weeks, respectively. Volunteer normal donor RBCs exhibited 50-percent lysis in 0.48-percent NaCl after 4 weeks. Median survival of the patient's 4-week-old 51Cr-labeled RBCs was severely shortened, at 3.5 days. At surgery, intraoperatively salvaged RBCs demonstrated osmotic fragility identical to that of the patient's RBCs freshly obtained by venipuncture. CONCLUSION: HS RBCs may lose membrane under optimum storage conditions, becoming unsuitable for transfusion at surgery. Intraoperative autologous transfusion may be preferable to preoperative deposit for avoidance of allogeneic RBC transfusion in patients with HS.

Anion Exchange Protein 1, Erythrocyte↗
PubMedDate not supplied

Neutralizing antibodies in Brazilian sera against three strains of human immunodeficiency virus type 1 (HIV-1).

The MN strain of HIV-1 is known to be more prevalent in Brazil, the BRU strain is more prevalent in Europe, and the NDK strain in Africa. It has been suggested in the literature to include different strains in the same vaccine against HIV-1. To contribute to the studies for the development of a universal vaccine, the occurrence of antibodies (Ab) against three HIV-1 strains (MN, BRU and NDK) was determined in serum samples from 85 HIV-1-positive patients, adult volunteers seen at the University Hospital of the Faculty of Medicine of Ribeirão Preto-USP. One-hundred tissue culture infective unit (TCIU) of the viruses reacted with serial dilutions of the sera (2x) and with MT4 cells added at a final concentration of 0.3 x 10(6) cells/ml, and a cytopathic effect was observed on the 7th and 11th days of incubation. Titres of less than 1/50 were considered to be negative. In 129 tests, the sera were negative for one of the three strains: 40 for MN, 29 for BRU and 60 for NDK. There was a predominance of strains MN and BRU, most of them presenting titres from 1/50 to 1/200. Titres for NDK were detected in 25 sera. We conclude that there seems to be a predominance of strains MN and BRU among the individuals from the region tested; however, the detection of sera with positive NKD titres indicates the need for further studies of this strain in other populations and regions of Brazil.

AIDS Vaccines↗
PubMedDate not supplied

Chromobacterium violaceum infection in Brazil. A case report.

We report the second case of infection with Chromobacterium violaceum that occurred in Brazil. A farm worker living in the State of São Paulo presented fever and severe abdominal pain for four days. At hospitalization the patient was in a toxemic state and had a distended and painful abdomen. Chest X-ray and abdominal ultrasound revealed bilateral pneumonia and hypoechoic areas in the liver. The patient developed failure of multiple organs and died a few hours later. Blood culture led to isolation of C. violaceum resistant to ampicillin and cephalosporins and sensitive to chloramphenicol, tetracyclin, aminoglicosydes, and ciprofloxacin. Autopsy revealed pulmonary microabscesses and multiple abscesses in the liver. The major features of this case are generally observed in infections by C. violaceum: rapid clinical course, multiple visceral abscesses, and high mortality. Because of the antimicrobial resistance profile of this Gram-negative bacillus, for appropriate empirical antibiotic therapy it is important to consider chromobacteriosis in the differential diagnosis of severe community infections in Brazil.

Adult↗