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Biomedical subjects

H Rocha

Publications and source records attributed to H Rocha.

At least 55 records · Page 3Linked to original sources

A prospective study of visceral leishmaniasis in an endemic area of Brazil.

The epidemiology, clinical patterns, and risk factors for visceral leishmaniasis were prospectively studied in an endemic area of Brazil. The prevalence of disease was 3.1% for children less than 15 years of age, and the annual incidence was 4.3 cases per 1,000 children. The number of children with disease fluctuated yearly and seasonally, and distribution of the disease varied within the endemic area. Risk factors included young age (median, three years) and malnutrition before the onset of disease. Intestinal parasitism, recent migration into the area, and house location within the area did not influence the progression of infection to disease. Serological testing indicated that 7.5% of children were infected with Leishmania each year and that the ratio of disease to infection was 1:18.5 for the whole area and 1:6.5 for the section with the highest prevalence of disease. Early diagnosis and therapy altered clinical patterns of the disease.

Adolescent↗

Renal involvement in visceral leishmaniasis.

In a prospective study of 50 patients with visceral leishmaniasis, laboratory abnormalities suggestive of renal involvement were not infrequent. Proteinuria and/or microscopic hematuria or pyuria were observed in 51% of such cases. Twenty-four hour urinary protein excretion was elevated in 57% of patients in all cases below 1g/24 hours. An abnormal acid-load test was demonstrated in 12 of 18 patients studied before therapy of the parasitic infection with N-methyl-glucamine. Of interest was the demonstration of tubulo-interstitial involvement in the renal histology of all seven patients studied; also, in five of seven patients there was a proliferative glomerulonephritis, usually mild, on histologic examination. In general, there was a tendency to subsidence of abnormal laboratory findings within one month after specific therapy. Renal involvement in visceral leishmaniasis was mild and seemed to revert with the cure of the leishmanial infection.

Adolescent↗

Comparison of ceftriaxone and ampicillin plus chloramphenicol for the therapy of acute bacterial meningitis.

Ceftriaxone, a new third-generation cephalosporin, appears to be promising for the therapy of acute bacterial meningitis. The 90% MBCs of ceftriaxone against 54 recent cerebrospinal fluid isolates of Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae were less than or equal to 0.06 to 0.25 micrograms/ml. We examined the efficacy and safety of ceftriaxone therapy of meningitis in Bahia, Brazil. The study was conducted in two phases; in phase A, ceftriaxone was coadministered with ampicillin. The mean cerebrospinal fluid concentrations of ceftriaxone 24 h after an intravenous dose of 80 mg/kg were 4.2 and 2.3 micrograms/ml on days 4 to 6 and 10 to 12 of therapy, respectively. These concentrations were 8- to more than 100-fold greater than the 90% MBCs against the relevant pathogens. In phase B, ceftriaxone (administered once daily at a dose of 80 mg/kg after an initial dose of 100 mg/kg) was compared with conventional dosages of ampicillin and chloramphenicol in a prospective randomized trial of 36 children and adults with meningitis. The groups were comparable based on clinical, laboratory, and etiological parameters. Ceftriaxone given once daily produced results equivalent to those obtained with ampicillin plus chloramphenicol, as judged by cure rate, case fatality ratio, resolution with sequelae, type and severity of sequelae, time to sterility of cerebrospinal fluid, and potentially drug-related adverse effects. The cerebrospinal fluid bactericidal titers obtained 16 to 24 h after ceftriaxone dosing were usually 1:512 to greater than 1:2,048 even late in the treatment course, compared with values of 1:8 to 1:32 in patients receiving ampicillin plus chloramphenicol. Ceftriaxone clearly deserves further evaluation for the therapy of meningitis; the optimal dose, dosing frequency (every 12 h or every 24 h), and duration of therapy remain to be determined.

Ampicillin↗

Cell mediated immunity in American cutaneous and mucosal leishmaniasis.

Cellular immune responses were studied in 35 Brazilian patients with either active cutaneous leishmaniasis (CL), active mucosal leishmaniasis (ML), or healed cutaneous leishmaniasis. The mean age and duration of illness in the two groups were as follows: 14 CL patients, age 28 +/- 13 yr, disease 5 +/- mo; and 16 ML patients, age 34 +/- 15 yr, disease 86 +/- 117 mo. Patients with CL and ML responded well to leishmania antigen in blastogenesis assays. However, the response of ML patients was over three times greater than the response of CL patients. There was a significant correlation between the magnitude of the lymphoproliferative response and the duration of disease activity. There were no significant differences between CL and ML patients in terms of the following parameters: lymphoproliferative responsiveness to mitogens (phytohemagglutinin, concanavalin A, and pokeweed mitogen) and peripheral blood lymphocyte subpopulations (T and B cells, oKT8+ and OKT4+ cells, OKT4:OKT8 ratio). Peripheral blood mononuclear cells from ML patients also generated interferon-gamma containing lymphokine in response to stimulation with leishmania antigen. This lymphokine was capable of inducing macrophages from ML patients to inhibit the intracellular multiplication of leishmania in vitro. These studies have determined that the parameters of lymphocyte and macrophage functions evaluated in ML and CL patients are comparable, except for an enhanced lymphoproliferative response, with leishmania antigen in ML patients. This later finding may be a function of the long duration of active disease in this population and unrelated to the pathogenesis of their mucosal lesions.

Adolescent↗

Rationale for clinical trials evaluating ceftriaxone in the therapy of bacterial meningitis.

Ceftriaxone is a promising antimicrobial agent in the therapy of bacterial meningitis. The rationale for the clinical evaluation of ceftriaxone in patients with meningitis is based on the following favorable characteristics: ceftriaxone has excellent in vitro activity (MBC90 0.25 microgram/ml or less) against the major meningeal pathogens including meningococci, pneumococci, group B streptococci, Hemophilus influenzae, and Escherichia coli, but it is inactive against Listeria monocytogenes; ceftriaxone is rapidly bactericidal within purulent cerebrospinal fluid in experimental animal models of meningitis induced by pneumococci, group B streptococci, H. influenzae, and E. coli; against most of the major meningeal pathogens, the activity attained in cerebrospinal fluid in human subjects with bacterial meningitis is high (1:512 or greater) and active concentrations of ceftriaxone persist in cerebrospinal fluid for prolonged periods compared with those of other cephalosporins; the results of clinical trials reported to date in patients with meningitis are encouraging. Ceftriaxone deserves further clinical evaluation in the treatment of bacterial meningitis; the optimal dose, frequency of administration, and duration of therapy remain to be determined.

Animals↗

Immunological features in different clinical forms of strongyloidiasis.

Serum immunoglobulin levels, skin test response to PPD, lymphocyte surface markers and eosinophil count in peripheral blood were studied in 35 patients with strongyloidiasis diagnosed by stool examination. The patients were divided into three groups based on clinical history, physical examination and laboratory examination: an asymptomatic group (14 patients), a symptomatic group (14 patients) and a group with severe parasitic infection (seven patients). In three of the seven patients with severe strongyloidiasis, massive infection caused by Strongyloides stercoralis had been diagnosed at least once before this study. The IgG levels were significantly lower (p less than 0.05) in patients with severe strongyloidiasis (1180 +/- 529 mg/dl) than in the asymptomatic group (2347 +/- 1224). IgA and IgM levels were also lower in the patients with massive infection when compared to the asymptomatic and symptomatic groups. No decrease of T cells or B cells was found in patients with severe strongyloidiasis. However, the eosinophil count was significantly lower in patients with severe strongyloidiasis than in asymptomatic or symptomatic patients (p less than 0.05). The authors suggest that eosinophils and antibodies may play an important role in the defence mechanism against S. stercoralis larvae.

Adolescent↗

Moxalactam for the treatment of bacterial meningitis in children.

Increasing resistance to antibiotics in meningeal pathogens has stimulated a search for new antimicrobial agents for the treatment of bacterial meningitis. Moxalactam penetrates well into infected cerebrospinal fluid (CSF) and is highly active against most gram-negative bacteria. The clinical efficacy and safety of moxalactam in the treatment of childhood meningitis caused by Haemophilus influenzae (25 patients) or Neisseria meningitidis (five patients) was evaluated in a random, uncontrolled study. The penetration of the antibiotic into CSF was also evaluated in these patients and in another five children with bacterial meningitis. The clinical results were excellent, with 29 of 30 cases cured. The single adverse clinical reaction noted was the development of a wound hematoma in a postoperative patient; this problem may have been related to moxalactam therapy. The levels of moxalactam achieved in CSF greatly exceeded the minimal bactericidal concentrations for the infecting organisms. Moxalactam appears to be safe and effective as primary therapy for meningitis caused by H influenzae or N meningitidis.

Adolescent↗

Pharmacokinetics of cefoperazone in normal subjects and patients with hepatosplenic schistosomiasis.

The pharmacokinetics of cefoperazone were studied and compared in four normal subjects and six patients with hepatosplenic schistosomiasis (HSS) with mild liver disease but marked portal hypertension. All subjects received a 2 g intravenous infusion of cefoperazone over 15 min. Although most pharmacokinetic parameters did not differ significantly between normal subjects and patients with HSS, the serum beta half-life of cefoperazone was longer in patients with HSS compared to normal subjects (3.0 h vs. 1.7 h). This demonstrates only mild impairment of excretion of cefoperazone in patients with HSS.

Adult↗

Circulating immune complexes and rheumatoid factor in schistosomiasis and visceral leishmaniasis.

Circulating immune complexes, measured by the C1q binding and Raji cell radioimmunoassays, were detected in 16 of 25 (64%) patients with schistosomiasis alone, in all 13 patients (100%) with schistosomiasis infection associated with prolonged bacteremia by salmonella organisms, and in 15 of 18 (83%) patients with visceral leishmaniasis. The C3 levels in the serum of patients with schistosomiasis, with and without prolonged salmonella bacteremia, were significantly lower in those with renal disease. Further, in patients with schistosomiasis alone, the absence of renal involvement was positively associated with C1q binding within the normal range (P = 0.015) and the presence of IgM rheumatoid factor in serum (P = 0.04). In six of eight patients with visceral leishmaniasis treated with a pentavalent antimonial, there was a fall in Raji cell binding, suggesting indirectly that the parasitic antigen may be involved in the pathogenic immune complexes in serum.

Adolescent↗

Cefamandole treatment of Salmonella bacteremia.

The efficacy of cefamandole in the treatment of 19 patients with salmonella bacteremia was evaluated. Although all of the salmonella strains isolated were highly susceptible to cefamandole in vitro, a therapeutic failure was observed in 7 (36.8%) of the 19 patients.

Cefamandole↗

Amoxicillin-clavulanic acid in treatment of urinary tract infection due to gram-negative bacteria resistant to penicillin.

Twenty-two adult patients with urinary tract infections caused by penicillin-resistant bacteria completed treatment with amoxicillin alone or amoxicillin plus clavulanic acid in a randomized double-blind clinical trial. Of the 13 patients treated with amoxicillin plus clavulanic acid, the absence of bacteriuria within 7 days of therapy was observed in 85%, as compared with only 25% of the 8 patients receiving amoxicillin only. There were no significant side effects nor any clinical, biochemical, or hematological abnormalities related to either treatment. It was concluded that the combination of clavulanic acid and amoxicillin could be useful in the treatment of uncomplicated urinary tract infection caused by penicillin-resistant bacteria.

Amoxicillin↗

Value of beta 1C/1A globulin serum levels as an early index of glomerular involvement in Schistosoma mansoni infection.

In attempting the early detection of glomerular abnormalities in patients with the hepatosplenic form of Schistosoma mansoni infection, the serum concentration of beta 1C/1A globulin was determined in 17 patients without clinical evidence of nephropathy. Renal biopsies were obtained during splenectomy in all of them. The serum levels of beta 1C/1A globulin were below the normal limit in eight patients; of these, two had histological evidence of focal proliferative glomerulonephritis, two others had membranoproliferative glomerulonephritis, and one showed focal sclerosing glomerulonephritis. Of nine patients with normal serum levels of beta 1C/1A globulin, eight had no glomerular abnormalities demonstrated by light microscopy. Determination of the serum concentration of beta 1C/1A globulin proved to be a valuable index for the detection of early glomerulopathy in patients with hepatosplenic schistosomiasis, since a low level correlated well with the histologic demonstration of glomerular involvement by light microscopy.

Adolescent↗

The role of glutathione in renal cortical tissue. Effects of diamide on Na+ and GSSG levels, amino acid transport and Na+-K+-ATPase activity.

The effects of diamide were studied in rat kidney cortical tissue. It was found that diamide increased oxidized glutathione levels and inhibited Na+-K+-ATPase activity. Consistent with this finding was the observation that diamide compromised the sodium gradients maintained in renal cortical slices. Amino acid transport studies with ouabain or a sodium-free buffer indicated that diamide interferes with both Na+-dependent and Na+-independent transport systems. These results indicate that diamide has a number of different effects on renal cortical tissue and emphasize the important role of glutathione in maintaining control of a number of key metabolic pathways.

Adenosine Triphosphatases↗