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Biomedical subjects

A A Silva

Publications and source records attributed to A A Silva.

34 records · Page 2Linked to original sources
PubMed1997

Intrathecal reactivity for myelin components precedes development of neurological symptoms in AIDS patients.

The central nervous system is considered an early and common target for the human immunodeficiency virus type 1 (HIV-1). Serum and cerebrospinal fluid (CSF) from 20 HIV positive patients, including 14 with AIDS-dementia complex (CDC stage IV) and 6 asymptomatic individuals (CDC stage II) were analyzed by enzyme immunoassay for detection of antibodies to native myelin basic protein (MBP) and for the amino acid sequence 68-84 exposed after partial degradation of native MBP. Control groups included HIV-1 negative patients with degenerative and/or vascular dementia, chronic multiple sclerosis (MS) and individuals without any sign of neurological or cognitive disturbances. As opposed to control groups, serum and CSF samples from MS and HIV-1 infected patients showed several oligoclonal bands running in the gamma region. AIDS-dementia complex (ADC) patients had increasingly high intrathecal IgG specific antibody titers for the amino acid sequence 68-84 of MBP. Marked intrathecal antibody production for myelin components was also detected in the majority of HIV-1 infected asymptomatic individuals. Such alteration paralleled development of cognitive deficits, neurological abnormalities and appearance of CNS demyelinating plaques. Preferential immune recognition of this myelin epitope within the CSF during early stages of HIV-1 infection might point to an ongoing process of active demyelination and ultimately indicate subclinical CNS involvement.

AIDS Dementia Complex↗
PubMed1993

Fever and neutropenia in children with cancer: a therapeutic approach related to the underlying disease.

Antibiotic monotherapy is increasingly an option for the initial empiric treatment of febrile neutropenic cancer patients. We noted in a previous study that response to empiric therapy was related more to disease classification (solid tumors vs. leukemia) than to the regimen chosen. In the present study we based empiric monotherapy on the underlying disease in treating 240 episodes of fever and neutropenia in 145 children. Patients with leukemia or Stage III/IV non-Hodgkin's lymphoma (higher risk group) were treated with imipenem-cilastatin, whereas those with solid tumors or Stage I/II non-Hodgkin's lymphoma (lower risk group) received ceftriaxone. The regimens were modified in 15% of lower risk and 45% of higher risk episodes. Overall successful outcomes were obtained in 93.2% of the higher risk (n = 119) and 97.5% of the lower risk (n = 121) episodes. The two groups differed significantly in duration of neutropenia, frequency of positive blood cultures and superinfection and the need for modification of the monotherapy (P < 0.05). Empiric monotherapy based on primary disease appears to be safe and effective for febrile neutropenic children with cancer at our Brazilian institution. Further studies will be needed before these findings can be generalized to patient populations in other settings.

Adolescent↗
PubMed1987

Leydig cell hypertrophy and hyperplasia in adult rats treated with an excess of human chorionic gonadotrophin (hCG).

A morphometric study was undertaken to determine to what extent the increase in LEYDIG cell activity is related to an increase in their number and/or size. An attempt was also made to consider the morphological characteristics of the cells in terms of their probable functional capacity. Following 8 h to 3 d of excess hCG treatment, LEYDIG cells nuclear volume exhibited an increase of 16 to 18% while no significant increase in cells number was observed. By 7 d of hCG treatment, the nuclear hypertrophy (42%) coexisted with hyperplasia (33%). After 14 d of stimulation, a 41% augment in cells number and 31% increase in nuclear volumes were found. Such morphometric parameters were correlated with plasma levels of testosterone. The results suggest that hypertrophy plays a more important role in the enhancement of LEYDIG cells secretory activity in the initial phase of hCG stimulation. A subsequent hyperplasia seems to become relatively more important in longer periods of treatment. Our findings support the statement that both hCG dose and time of treatment, and consequently the plasma level of testosterone, are important parameters to be considered when the functional activity of LEYDIG cells is been evaluated by morphometric techniques.

Animals↗
PubMedDate not supplied

Pulmonary hypertension in schistosomiasis mansoni.

To evaluate cardiopulmonary involvement in schistosomiasis mansoni, 246 patients from an endemic area of Brazil were examined; 152 had been previously treated for schistosomiasis. Based on stool examination and/or abdominal ultrasonography, the patients were divided into those with schistosomiasis (69%) and those in whom the disease was not present (31%). M mode measurements were similar in the 2 groups. Pulmonary pressure was measured by Doppler echocardiography; 25% of the subjects had pulmonary hypertension. Those with pulmonary hypertension had a higher prevalence of schistosomiasis (80%) than those without (64%; P = 0.03). No case of cor pulmonale was diagnosed by electrocardiography or Doppler echocardiography. The prevalence of pulmonary hypertension correlated neither with periportal fibrosis nor with prior treatment for schistosomiasis.

Adult↗
PubMedDate not supplied

A case of human rabies in the urban area of Ribeirã Preto, SP, Brazil.

A 39-year old male patient was admitted to the University Hospital of the Faculty of Medicine of Ribeirão, Preto with signs and symptoms of sudden dyspnea, generalized myalgia and behavioral disorders. The initial suspicion was alcohol abstinence syndrome and the patient was referred for psychiatric and neurologic care. The evolution of the patient with a worsening of signs and symptoms, presence of crises of tachypnea, agitation, difficulty to swallow, irritability and hydrophobia, and his report of having been bitten by a suspected dog raised the hypothesis of rabies. The diagnosis was confirmed by examination of a corneal impression, biological tests in the cerebrospinal fluid (CSF) and saliva and visualization of Negri bodies in nervous tissue (direct immunofluorescence). The patient evolved with agitation, aggressiveness, and worsening tachypnea intercalating with apnea, and died on the 4th day after admission.

Adult↗
PubMedDate not supplied

[Monitoring of lettuce crops of Ribeirão Preto, SP, Brazil].

The ingesting of raw vegetables plays an important role in the transmission of several infectious diseases due to the high frequency of irrigation with wastewater. The objective of this study was to evaluate the sanitary conditions of all lettuce producing crops in Ribeirão Preto through microbiological and parasitological analysis of both irrigation water and lettuce together with the implantation of an effective crop monitoring. Laboratory analysis of 129 crops showed irregularities in 26 (20.1%) of these: high concentration of fecal coliforms in 17% of the lettuce, presence of Salmonella in 3.1% and several enteroparasites (Ascaris sp, Ancylostomidae, Strongyloides sp, Hymenolepis nana, and Giardia sp ) in 13.1%. Persistent irregularities determined the definitive closing down of one producer; all of the remaining 128 crops were eventually approved, thus demonstrating the efficacy of lettuce crop monitoring. Crops approved in the laboratory analysis were awarded a Sanitary Inspection Certificate - an unprecedented procedure in our Country - that resulted in a better acceptance of the monitoring.

Agriculture↗
PubMedDate not supplied

[Leishmania (Leishmania) chagasi infection in children from an endemic area of visceral leishmaniasis in the São Luís Island-MA, Brazil].

A prospective study was undertaken in 648 children with less than 6 years of age in the municipality of Raposa, Maranhão, Brazil, from June 1997 to June 1998, to evaluate the characteristics of the infection by L.(L.)chagasi and verify if there is an association between malnutrition and asymptomatic infection. A standardized questionnaire was used containing socioeconomic, environmental and behavioral data. Montenegro skin reaction (IDRM) with L. amazonensis and Enzyme Linked Immunosorbent Assay (ELISA) test to detect infection, and anthropometric examination were performed. Initial and final prevalence and incidence of infection were 18.6%, 20.6% and 10.8% as measured by IDRM and 13.5%, 34.4% and 28% according to ELISA. The prevalence of chronic malnutrition was 26%. No association was detected between malnutrition and asymptomatic infection by L. (L.) chagasi. More effective control measures are needed in these areas since asymptomatic infection seems to be on the increase.

Brazil↗
PubMedDate not supplied

Influence of physical exercise and sodium intake on arterial pressure and cardiac hypertrophy in rats.

Evidence shows that cardiac hypertrophy (CH) is a risk factor for many cardiovascular diseases. Several stimuli may cause CH-like manifestations and promote volume or pressure overload. Exercise-induced cardiac hypertrophy is an expected adaptation to regular exercise training. Salt intake has been shown to be the most important determinant of blood pressure in different populations. The purpose of the present work was to verify the influence of physical exercise and sodium intake on the blood pressure and myocardium. The study was performed on 36 rats divided into six groups: Group I (diet without salt overload), Group II (diet without salt overload and swimming), Group III (diet with 2.5% NaCl solution and swimming), Group IV (diet with 5% NaCl solution and swimming), Group V (diet with 2.5% NaCl solution without exercise), Group VI (diet with 5% NaCl solution without exercise). The arterial pressure was significantly lower in Group I when compared with Group IV. The ratio of cardiac mass/body mass was increased in Groups III and IV. In conclusion, there was evidence that exercise training and NaCl intake promotes arterial hypertension and cardiac hypertrophy.

Animals↗
PubMedDate not supplied

[Risk factors for hospitalization of children aged 1 to 4 years in Sao Luis, Maranhao, Brazil].

Risk factors for pediatric hospitalization were studied using a cross-sectional multi-stage cluster sample survey. A standardized questionnaire was answered by children's mothers or other care providers. In the municipality of São Luís, Maranhão, Brazil, 596 children aged 1 to 4 years were sampled in 50 census tracts. Design effect was calculated for each estimate. Hospitalization rate was 24. 4%. Main causes of hospitalization were pneumonia (7.3%) and diarrhea (7.1%). The Unified National Health System (SUS) and private insurance accounted for 78.1% and 18.2% of hospital admissions, respectively. After adjustment for confounding by Cox proportional hazards model modified for cross-sectional design, children whose families earned less than one minimum monthly wage and those with private insurance were at higher risk of hospitalization. Hospitalization due to outpatient-sensitive diseases accounted for most cases. The U-shaped hospitalization pattern suggests low quality of outpatient services among the poor and may be a proxy indicator for unnecessary and iatrogenic hospitalization among privately insured children.

Brazil↗
PubMedDate not supplied

[Neonatal mortality trends in São Luís, Maranhão, Brazil, from 1979 to 1996].

This study examined neonatal mortality trends in São Luís in the last 18 years. The early and late components were assessed and causes were classified according to SEADE Foundation criteria based on reducibility of deaths and timing of prevention (during prenatal care, childbirth, or neonatal care). Data were derived from official live birth and death records. We detected an unexpected increase in the neonatal mortality rate, due primarily to a steep rise in early neonatal deaths. Causes reducible by early diagnosis and treatment (other specific infections and other neonatal respiratory causes) and those partially reducible by adequate monitoring of pregnancy (preterm births, low birth weight, and respiratory distress syndrome) showed the largest increase. Conversely, the post-neonatal mortality rate fell. The infant mortality rate remained the same, reflecting these antagonistic trends. The important rise in the neonatal mortality rate from 1995 onwards suggests a deterioration in the quality of obstetric and neonatal services. The high cesarean rate and overcrowded neonatal services (i.e., unable to cope with increasing demands foe specialized neonatal care) indicate the urgent need for restructuring the mother and child health care system.

Brazil↗
PubMedDate not supplied

Abdominal colpopexy for complete prolapse of the vagina.

A comparative study of abdominal colpopexy using rectus fascia and sacral fixation for the treatment of prolapsed vagina following hysterectomy was performed. The abdominal approach yields better results than the vaginal route. Fixation of the vaginal vault using a Dacron prosthesis is more rational and was the method of choice, resulting in a complete cure in 10 of 11 patients. The Brady technique failed in 25% of cases.

Abdominal Muscles↗
PubMedDate not supplied

[Fever and neutropenia in children with cancer: a new therapeutic proposal].

Based on our previous experience treating children with cancer, fever and neutropenia we selected two different empirical regimens: Ceftriaxone once a day, for patients with solid tumors and lymphomas I-II (Low Risk group--LR) and Imipenem for patients with leukemias and lymphomas III-IV (High Risk group--HR). From Oct 1988 to Nov 1989, 121 episodes of fever (F+) and granulocytopenia (G+) in LR Group and 119 in HR Group were studied: the HR had 51.3% documented infections and the LR 58.7%. In the HR Group the following organisms were isolated from the blood cultures: Gram + 52%, Gram - 20% and fungal 28%. In the LR Group 78% of the organisms were Gram+. Positive blood cultures was 21% for the HR Group and 8.3% for the LR Group. There were 23.5% superinfections in the HR Group vs 5.7% in the LR. The mean time and the median time of granulocytopenia was 11.5 and 8 days (HR) and 6.9 and 6.0 days (LR), respectively. There were 14.5% (LR) and 45.4% (HR) modifications to the initial empirical antibiotic regimen (Amphotericin B, Vancomycin and Amikacin). The overall success rate was 97.6% (LR) and 94.2% (HR) and for documented infection the success rate was 95.7% (LR) and 91.8% (HR). We conclude that: a) The allocation of patients to two risk groups aiming to use distinguished therapy, allowed us to delineate two different populations, predominantly based on time of granulocytopenia, disappearance of fever, rate of superinfection, causative organisms and need of additional drugs to the initial scheme.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗