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R Zuniga

Publications and source records attributed to R Zuniga.

4 recordsLinked to original sources

The influence of verapamil on theophylline serum concentrations.

The effect of verapamil on steady state levels of theophylline were studied in 10 healthy volunteers. Sustained release theophylline 3 mg/kg/day was administered 3 days prior to, and during a 7 day treatment of verapamil 80 mg three times daily. Steady state theophylline levels were measured before giving verapamil and on days 3, 5, and 7 of verapamil. Blood for theophylline assay was drawn one hour before the morning theophylline dose. The results showed no statistically significant difference in theophylline levels before and after verapamil. We conclude that oral verapamil does not affect the disposition of oral theophylline at the dose studied.

Adult

Pertussis toxin is required for pertussis vaccine encephalopathy.

A mouse model for encephalopathy induced by pertussis immunization has been described; it has features that closely resemble some of the severe reactions, including seizures and a shock-like state leading to death, occasionally seen after administration of Bordetella pertussis (whooping cough) vaccine. Susceptibility to encephalopathy maps to genes of the major histocompatibility complex and correlates as well with the genetic regulation of the level of antibody response to bovine serum albumin. In this study we have investigated which bacterial determinant is responsible for the encephalopathy. Two lines of evidence implicate pertussis toxin as the active bacterial component. Single-site mutants of B. pertussis with single affected virulence factors were tested. A mutant that produces a defective pertussis toxin had greatly diminished capacity to induce encephalopathy, whereas a hemolysin- and adenylate-cyclase-deficient avirulent mutant had the same activity in the mouse model as a virulent strain. Purified pertussis toxin plus bovine serum albumin was tested and found to induce the lethal encephalopathy, demonstrating that the toxin was the critical constituent of B. pertussis responsible for encephalopathy.

Adenylate Cyclase Toxin

Murine model for pertussis vaccine encephalopathy: role of the major histocompatibility complex; antibody to albumin and to Bordetella pertussis and pertussis toxin.

A mouse model for pertussis immunization encephalopathy has been described with features that closely resemble the severe adverse reactions occasionally seen after pertussis vaccine administration,m including seizures and a shock-like state leading to death. These reactions are produced with nearly one hundred percent efficiency provided that the mice immunized with Bordetella pertussis have 1) the appropriate major histocompatibility (H-2) genotype, 2) have been sensitized to bovine serum albumin (BSA), and 3) that the injected B. pertussis contained sufficient amounts of pertussis toxin. Antibody titres were measured in mice with haplotypes H-2d.s.k. that are highly susceptible to encephalopathy as well as in H-2b mice, that are totally resistant. Mice with H-2d.s.k. haplotypes were high responders to BSA, while H-2b (B10) mice were non-responders to BSA. Both H-2d and H-2b mice responded well to B. pertussis. Encephalopathy was induced in resistant H-2b mice with B. pertussis and passively administered anti-BSA antiserum, but not with B. pertussis and anti-(T,G)-A--L antibody. This indicated that B. pertussis and anti-BSA were absolutely required for development of encephalopathy. Encephalopathy could be induced in mice decomplemented with cobra venom factor and given BSA and B. pertussis. Several single-site mutants of B. pertussis affecting single virulence factors were induced with transposon Tn5. One of these mutants, BP357, deficient in pertussis toxin production, had a greatly reduced encephalopathic potential in the mouse model compared to the virulent strain BP 338, or to BP348, an adenylate cyclase and hemolysin double mutant, or to BP 349, a hemolysin mutant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenylate Cyclase Toxin

Partial trisomy 4q.

Three new cases (one patient and two sibs) of partial trisomy 4q resulting from a parental translocation are reported. From the literature 22 cases are reviewed and the segregation risk of unbalanced and balanced translocations involving 4q chromosome is discussed.

Chromosome Aberrations