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Biomedical subjects

O Muñoz

Publications and source records attributed to O Muñoz.

At least 91 records · Page 5Linked to original sources

Sensitive enzyme immunoassay for early diagnosis of tuberculous meningitis.

Cerebrospinal fluid from patients with tuberculous, pyogenic, and viral meningitis, as well as from appropriate control individuals, were assayed for immunoglobulin G and immunoglobulin M antibody activity to Mycobacterium bovis BCG by an enzyme-linked immunosorbent assay. BCG linked covalently to plastic disks served as the antigen in a classical indirect enzyme-linked immunosorbent assay. A significant difference was found between the tuberculous meningitis group and the nontuberculous meningitis and control groups. All samples from the tuberculous meningitis group gave a positive reaction, and none of the known negative samples gave false-positive reactions. Because of its sensitivity, specificity, and predictive value, this test may be useful in the early diagnosis of tuberculous meningitis.

Adolescent↗

Screening for ampicillin resistant Hemophilus influenzae and penicillin resistant Streptococcus Pneumoniae in healthy carriers.

800 samples of pharyngeal exudate were taken from healthy children and 28 healthy intrafamilial contacts of children with meningitis caused by H. influenzae type b. H. influenzae type be was isolated in 8.7 per cent of nursery children, H. influenzae type e in 0.12 per cent and non typifiable H. influenzae in 5.8 per cent. On intrafamilial contacts, 32 per cent had H. influenzae type b and non typifiable in 3.5 per cent. Percent age of ampicillin resistant H. influenzae type b was 14 per cent. No strains were found resistant to chloramphenicol. S. pneumoniae was isolated in 37 per cent of pharyngeal exudate samples. 25.5 per cent of strains tested were penicillin sensitive; 74.5 per cent has a decrease sensitivity. Based on these results we consider chloramphenicol to the the first drug of choice for treatment of severe H. influenzae infections and penicillin for S. pneumoniae infections recommending in the latter higher doses when dealing with central nervous system infections.

Ampicillin↗

Different polypeptide composition of two human rotavirus types.

Human rotaviruses, which are placed into two groups according to their ribonucleic acid patterns obtained by gel electrophoresis, were characterized both by polypeptide components from purified virions and by polypeptides translated from their denatured ribonucleic acids in rabbit reticulocyte lysates. Viruses assigned to different groups differed in the electrophoretic migration of the second largest of the polypeptides which compose the inner shell; polypeptides that had been synthetized in vitro from ribonucleic acid from each group showed this same difference, thus indicating that this is due to the genomic composition. This study suggests that there are differences in the third largest polypeptide of the inner shell and also in the three smaller polypeptides composing the outer shell. We also demonstrated that there are differences in genomic and polypeptide compositions between simian (SA11) and calf (Nebraska calf diarrhea virus) rotaviruses grown in tissue culture and human rotaviruses.

Capsid↗

Comparison of human rotaviruses isolated in Mexico City and in Santiago, Chile, by electrophoretic migration of their double-stranded ribonucleic acid genome segments.

During the period October to December 1979, rotaviruses were obtained from infants and young children hospitalized with acute gastroenteritis in Mexico City and were compared by analysis of the migration of their double-stranded ribonucleic acid (RNA) genome segments in gel electrophoresis. Comparison of the results of this analysis and of those of similar studies carried out in 1977 and 1978 showed that the two rotavirus electropherotypes designated 2s and 21 have been continuously present and that the proportion in which these two types have been found in hospitalized patients has varied greatly year to year. The RNAs from rotaviruses 2s and 21 differed in the electrophoretic migraton of at least eight genome segments. However, RNAs from virus assigned to the same electrophoreotypes were not necessarily identical: on the basis of small but significant differences in the migration of segment 7, 8, or 9, isolates of types 2s and 21 could be assigned to two and three different subtypes, respectively. Human rotaviruses obtained in a distant geographical region, Santiago, Chile, in July 1979 had RNA electrophoretic patterns similar to that of electropherotype 21 but different from it in the migration of one or two of the larger RNA segments.

Child, Preschool↗

[Coproantibodies in intestinal amebiasis].

E. histolytica tissue invasion induces IgG and IgM and probably IgA serum antibody formation of different types in the intestinal mucosa. 21 children with intestinal invasive amebiasis were studied. Samples were taken from peripheral blood and stools during diagnostic studies and three weeks later. Contraimmunoelectrophoretic antibody determinations and indirect hemagglutination tests IH were made in an attempt to demonstrate its true nature. During the acute phase (first sample), results showed antibodies against amoeba in stools by CIE in 57 per cent and by IH in 80 per cent; in serum, results were 38 and 76 per cent respectively. In the second sample and three weeks after diagnosis was established a decrease in the number of patients with coproantibodies against amoeba was observed and the number of patients with serum antibodies increased. We are also providing evidence that supports the IgG and IgA nature of coproantibodies against amoeba. These results suggest the presence of a local immunological reaction in invasive amebiasis.

Antibodies↗

Detection of antibodies to Salmonella "O" antigens in typhoid fever by counterimmunoelectrophoresis. I. Description of technique.

In the serum of patients with typhoid fever counterimmunoelectrophoretic techniques were used for the detection of antibodies to Salmonella "O" antigen. Lipopolysacharides (LPS) obtained with phenol and water from Salmonella typhi (antigens 0, 9 and 12) were used. Positive results were obtained in those patients with typhoid fever (20). The lower and higher titration levels were 1:8 and 1:32 respectively; the geometric mean was 1:16. The variation coefficient during the intra assay tests was 0.19, and remained stable throughout the inter-assay tests. Reproducibility, as well as a rapid technique, make this test a valuable tool for the serologic diagnosis of typhoid fever.

Adolescent↗

Prospective study of enteropathogens in children with diarrhea in Houston and Mexico.

During a 22-month period, 595 children with diarrhea and 210 age-matched controls attending clinics in Houston (367 children) and Mexico (438) were prospectively evaluated for enteric pathogens. Enteropathogens associated with disease were Shigella (18%), rotavirus (14%), Salmonella (9%), toxigenic Escherichia coli (6%), and others (12%), including 14 Proteus isolates that caused rounding of adrenal cells. Enteropathogens were isolated from a greater (P less than 0.001) number of children with diarrhea (59%) than from asymptomatic controls (6%). Paired sera tested for antibody to heat-labile toxin of E. coli rarely demonstrated a fourfold rise during episodes of diarrhea. This study demonstrates: (1) more striking illness in children from Mexico; (2) more common occurrence of Shigella in Houston, and of rotavirus and Salmonella in Mexico; (3) lack of seasonal occurrence of rotavirus isolation in either population and a summertime occurrence of Shigella in Houston; (4) lack of toxigenic E. coli isolation in endemic diarrhea of either population; and (5) a significant (P less than 0.001) age-related acquisition of E. coli LT antibodies.

Antibodies, Bacterial↗

[pH and lactic acid values in the cerebrospinal fluid as a diagnostic aid for differentiating viral and purulent meningoencephalitis].

Concentrations of lactate and pH were determined in the CSF of 20 normal children, 36 with viral meningitis, 16 with purulent meningitis and six with tuberculous meningitis. No differences were found between normal cases and those with viral meningitis. In patients with purulent meningitis concentration of lactate was above 30 mg/100 ml and pH below 7.3. Both determinations allowed differentiation between viral meningitis and purulent meningitis after 48 hr of treatment with antibiotics in 80% of the cases.

Adolescent↗