Biomedical subjects

S M Carvalho

Publications and source records attributed to S M Carvalho.

9 recordsLinked to original sources

PubMed2001

Diagnosis of HAM/TSP based on CSF proviral HTLV-I DNA and HTLV-I antibody index.

The contribution of human T-cell lymphotropic virus (HTLV-I) DNA by PCR in CSF and the intrathecal synthesis of antibodies to HTLV-I by the antibody index (AI) to the diagnosis of HTLV-1-associated myelopathy (HAM)/tropical spastic paraparesis (TSP) were evaluated. Cases of spastic paraparesis compatible with HAM/TSP had increased AI for HTLV-I (60/73) and HTLV-I proviral sequences in CSF (25/27). Among 27 patients with other neurologic diseases, three had increased AI and another three had positive HTLV-I DNA in CSF. Thus, the combination of PCR for proviral DNA and AI for HTLV-I in CSF provides consistent criteria for the diagnosis of HAM/TSP.

Chi-Square Distribution↗

PubMed2001

Intracellular calcium mobilization by muscarinic receptors is regulated by micromolar concentrations of external Ca2+.

Carbachol-induced contractions of rat stomach fundus strips, obtained in a nutrient solution containing 1.8 mM Ca2+, were resistant to Ca2+ withdrawal, even after 1 h of bathing the tissues in a nominal 0 Ca2+ solution. This was not observed when K+ was used to evoke contractions, which were rapidly inhibited after Ca2+ removal (t1/2=2 min). The effect of carbachol in 0 Ca2+ solution was reduced by using drugs that reduce intracellular pools of Ca2+, such as caffeine (1-3 mM), ryanodine (30 microM) or thapsigargin (1 microM), corroborating the involvement of intracellular Ca2+ stores. On the other hand, when the 0 Ca2+ solution contained EGTA, a complete decline of carbachol effects was observed within about 8 min, indicating the involvement of extracellular Ca2+. Atomic absorption spectrometry showed that our 0 Ca2+ solution still contained 45 microM Ca2+, which was drastically reduced to 5.9 nM in the presence of EGTA. Taken together, our results indicate that the effects of carbachol are due to the mobilization of caffeine-, ryanodine- and thapsigargin-sensitive intracellular Ca2+ stores, and that these stores are not inactivated or depleted if micromolar concentrations (45 microM), but not nanomolar concentrations (5.9 nM) of Ca2+ are maintained in the extracellular milieu.

Animals↗

PubMed2001

Infection with hepatitis A and TT viruses and socioeconomic status in Rio de Janeiro, Brazil.

The prevalence of antibodies directed against the enterically transmitted hepatitis A virus (HAV) was measured in 2 groups of people living in Rio de Janeiro, Brazil. Of 1,056 health care workers (HCWs), 778 (73.7%) were anti-HAV positive. A high prevalence of anti-HAV antibodies (85.7%) was also found among 274 voluntary blood donors (BDs). TT virus (TTV) is a DNA virus that has been found in the sera of patients with post-transfusion hepatitis of unknown etiology. Occurrence of virus shedding suggests that the fecal-oral route may be an important mode of TTV transmission, particularly in the developing world. The presence of TTV DNA was analyzed by PCR in the sera of 191 HCWs and 151 BDs. TTV was detected in 65.4% of HCWs and 79.5% of BDs. In both groups, a family income of < US$400 per month and a level of education of < 11 y of schooling were found to be risk factors for HAV infection. Furthermore, a low family income was associated with TTV viremia in the HCW group. However, the presence of TTV DNA was associated with neither low level of education nor anti-HAV positivity.

Adolescent↗

PubMed2001

Adult T-cell leukemia/lymphoma and cluster of HTLV-I associated diseases in Brazilian settings.

We studied the transmission routes of human T-cell lymphotropic virus type I (HTLV-I) within families of 82 Brazilian patients diagnosed with adult T-cell leukaemia/lymphoma (ATL). Diagnosis of ATL in 43 male and 39 female patients was based on clinical and laboratory criteria of T-cell malignancy and detection of HTLV-I monoclonal integration. Samples were tested for HTLV antibodies and infection was confirmed as HTLV-I by Western Blot and/or polymerase chain reaction (PCR) assays. Overall 26/37 (70%) of mothers, 24/37 (65%) of wives, 8/22 (36%) of husbands, 34/112 (30%) of siblings and 10/82 (12%) offspring were HTLV-I infected. In 11 ATL patients, mothers were repeatedly HTLV-I seronegative, but HTLV-I pol or tax sequences were detected in 2 out of 6 cases tested by PCR. ATL patients with seronegative mothers related the following risk factors for HTLV-I infection: 6 were breast-fed by surrogate mothers with unknown HTLV-I status, 4 had a sexually promiscuous behaviour and 1 had multiple blood transfusions at a young age. Familial aggregation of ATL and other HTLV-I associated diseases such as HTLV-I myelopathy (HAM/TSP) and or uveitis, ATL in sibling pairs or in multiple generations was seen in 9 families. There were 6 families with ATL and TSP sibling pairs. In 3 families at least one parent had died with lymphoma or presenting neurological diseases and 2 offspring with ATL. Further to the extent of vertical and horizontal transmission of HTLV-I infection within ATL families, our results demonstrate that mothers who provide surrogate breast-milk appear to be an important source of HTLV-I transmission and ATL development in Brazil.

Brazil↗

PubMed1995

T-cell malignancies in Brazil. Clinico-pathological and molecular studies of HTLV-I-positive and -negative cases.

T-cell malignancies in Brazil have a high seroprevalence rate of HTLV-I antibodies. We have analyzed the disease features in 188 Brazilian patients with a T-cell disorder. These included 40 with T-lymphoblastic leukaemia or lymphoma (T-ALL/T-LbLy) and 148 with mature T-cell diseases: 5 T-prolymphocytic leukaemia, 53 adult T-cell leukaemia/lymphoma (ATLL), 54 cutaneous T-cell lymphomas, 29 pleomorphic T-cell lymphomas and 7 large granular lymphocyte leukaemia. The diagnosis was based on clinical, morphological and immunological features and HTLV-I serology. ATLL in Brazil has the same diseases features as in other endemic regions, the only apparent differences being: age, Brazilian patients being younger than Japanese, and ethnic grouping, one third of Brazilians being white Caucasians of European descent. We applied a scoring system based on the presence or absence of typical features associated with ATLL; hypercalcaemia, cell morphology, immunophenotype, histopathology and HTLV-I status, to see whether it may help in diagnosing cases of ATLL. All had high scores, whereas all other T-cell diseases scored low. Only 5 ATLL cases were HTLV-I-negative by serology, but they had otherwise typical features of ATLL, and their cells did not have HTLV-I proviral sequences by DNA analysis. Such cases suggest that ATLL may develop in a minority of individuals living in regions where it is endemic, without evidence of HTLV-I infection, and that other factors may contribute to the pathogenesis of the disease.

Adolescent↗

PubMed1992

The effect of fasting and refeeding on oxygen consumption by rats.

Oxygen consumption is usually measured on fasted animals to avoid the thermal effect of feeding. However, fasting itself may decrease oxygen consumption as a way of conserving energy. The present study was undertaken to determine how long the fasting period should be to avoid the thermal effect of feeding without promoting a further decrease in oxygen consumption by the activation of energy-conservation mechanisms. Oxygen consumption was also measured to evaluate the effect of refeeding after different fasting periods. There was a 16% decrease in oxygen consumption from 0 to 12 h fasting related to the thermal effect of feeding, followed by a less intense (12%) decrease from 12 to 48 h fasting resulting from the energy conservation mechanism. During refeeding, oxygen consumption was higher during the first 30-min period than during the last 30-min period of the 1-h measurement, indicating the probable presence of a cephalic phase of postprandial thermogenesis. We conclude that 12-h fasting is the most appropriate period to avoid the thermal effect of feeding without significantly stimulating the energy conservation mechanism.

Animals↗

PubMed1982

Distribution and clearance of 63Ni administered as 63NiCl2 in the rat: intratracheal study.

Microgram amounts of nickel as 63NiCl2 were administered intratracheally to male rats. Regardless of time after instillation, the lungs and kidneys retained the greatest concentration of 63Ni, and 21 days after dose administration they were the only organs where 63Ni was still measurable. Urinary excretion was the main excretion route with 72% of the initial body burden eliminated by the urine at one day. By day 21, almost all 63Ni was excreted in the urine (96.5% of the initial body burden). The lungs retained 29% of their initial (35 min) burden at day 1, decreasing to 0.1% on day 21.

Animals↗

PubMedDate not supplied

Human T-lymphotropic virus type I tax polymorphisms in a transmission cohort: no association between sequence variation and disease manifestations.

OBJECTIVE: To determine whether a unique human T-lymphotropic virus type I (HTLV-I) transmission cohort containing multiple disease manifestations could be used to establish a relationship between tax gene sequence and HTLV disease expression. METHODS: DNA was extracted from the peripheral blood mononuclear cells (PBMC) of the HTLV-infected persons in the cohort. A 1.1-kb fragment of tax was amplified by polymerase chain reaction (PCR) and cloned. Six to 12 individual clones were sequenced per person. RESULTS: Comparison to a reference ATK strain showed numerous differences; however, consensus tax sequences from all persons within the transmission cohort were identical. Intraperson variation was 0.1% to 0.3%. Tax sequences from the index case did not differ from those obtained from a transfusion recipient who developed tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM). Tax sequences from the same index case did not differ from sequences obtained from the asymptomatic or ATL phases of a second recipient. CONCLUSIONS: In this cohort there did not appear to be tax genotypes associated with specific disease manifestations of HTLV infection.

Cohort Studies↗

PubMedDate not supplied

[Abdominal liposarcomas].

Abdominal liposarcomas are a rare group of tumors and their principles of treatment are based in accumulated experiences of retrospective series. PURPOSE--To report seven cases of abdominal liposarcomas and to discuss the main diagnostic and therapeutic aspects of these tumors nowadays. METHODS--Seven patients operated for abdominal liposarcomas were in the Surgical Gastroenterology Discipline of Escola Paulista de Medicina (UFESP) during 30 months. The major clinic, ultrasonographic, tomographic, surgical and histopathological features were collected in each case. RESULTS--Authors call attention to the unusualness of these tumors, their propensity (while primary) to grow in their own place, without invading the tissues around or metastasizing, and when they are recurrent to their more aggressive malignity. They consider that computerized tomography is the most useful diagnostic procedure and they discard the need of percutaneous biopsy (guided or not) in the preoperative period. They emphasize the fundamental role of radical excision surgery in these tumors treatment and also emphasize the importance of the resection with proper margins, even if an associated resection of visceral organs is necessary. They consider that now radiotherapy and chemotherapy are not very effective methods to the adjuvant treatment of these tumors. CONCLUSION--It is important an accurate follow-up of the operated patients in order to indicate, when necessary, repetitive resection surgeries, even if they are palliative (citoredution surgeries), with the purpose of improving the expectation of life.

Adult↗