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Biomedical subjects

J Munoz

Publications and source records attributed to J Munoz.

At least 37 records · Page 2Linked to original sources
PubMed1989

Production of acid and alkaline phosphatases by Myxococcus coralloides.

Acid and alkaline phosphatase of Myxococcus coralloides were examined during vegetative growth in a liquid medium. Two extracellular phosphatases and two cell-bound phosphatases, acid and alkaline in both cases, were produced. The phosphatase production was unaltered by the presence of high concentrations of inorganic phosphate. Both enzymes were produced constitutively. These two hydrolases were released into the growth medium during the exponential growth phase (approximately 10% of total activity). The production of these enzymes was modified by the presence of organic acids and metal ions in the medium.

Acid Phosphatase↗
PubMed1985

Fetal-neonatal passive immunization against Hemophilus influenzae, type b.

Twenty-one pregnant women were vaccinated with the polyribophosphate capsular antigen of Hemophilus influenzae, type b, at 34 to 36 weeks of gestation. All women experienced a large boost in their own antibody levels of anti-polyribophosphate capsular antigen, and 30% was transferred to their newborn infants. The newborn serum anti-polyribophosphate capsular antigen level at birth was 100-fold greater than that of control newborn infants, and the antibody persisted at a protective level for 12 months. Since newborn infants lose significant antibody by 3 months of age, they are susceptible to infection by Hemophilus influenzae, type b, such that it is the leading cause of meningitis in infants. The passive levels of anti-polyribophosphate capsular antigen achieved in these fetuses-neonates by active immunization of their mothers should theoretically lead to less disease caused by Hemophilus influenzae, type b, during infancy.

Antibodies, Bacterial↗
PubMed1985

Pertussis toxin inhibits fMet-Leu-Phe- but not phorbol ester-stimulated changes in rabbit neutrophils: role of G proteins in excitation response coupling.

Addition of pertussis toxin to rabbit neutrophils inhibits the fMet-Leu-Phe- induced increases in Na+ influx and in intracellular pH. In addition, pretreatment of the cells with the toxin inhibits the decrease in the levels of phosphatidylinositol 4,5-bisphosphate and phosphatidylinositol 4-phosphate and the enhanced production of phosphatidic acid produced by the chemotactic factor fMet-Leu-Phe. Furthermore, the fMet-Leu-Phe-induced changes in the phosphorylation of a 46-kDa protein and of several other proteins are also inhibited by the toxin. On the other hand, the phorbol 12-myristate 13-acetate (PMA)-induced increases in the phosphorylation of several proteins are not inhibited by the toxin. PMA, but not its inactive analogue 4 alpha-phorbol 12,13-didecanoate, was also found to stimulate Na+ influx and to increase the intracellular pH in rabbit neutrophils. These ionic effects, like those produced by fMet-Leu-Phe, are inhibited by amiloride. The stimulated Na+ influx and H+ efflux produced by the phorbol ester, on the other hand, are not inhibited by pertussis toxin. The results reported here suggest that the activity of the Na+/H+ antiport in neutrophils is regulated by protein kinase C; that the G-protein system, either directly or indirectly, is involved in the stimulus-response coupling sequence in these cells; and that the toxin acts at, or prior to, the steps responsible for the activation of phospholipase C, and it does not affect the sequence of reactions initiated by the activation of the protein kinase C.

Animals↗
PubMed1984

Twice daily ceftriaxone therapy for serious bacterial infections in children.

The clinical efficacy and safety of ceftriaxone, a long half-life cephalosporin were evaluated in 48 children with a variety of serious bacterial infections. Clinical cure was achieved in 92% (44 of 48) of patients. Peak serum bactericidal titres for Haemophilus influenzae type b, Streptococcus pneumoniae, Str. pyogenes and Escherichia coli were greater than or equal to 1:1024. Mean peak and trough ceftriaxone levels were 173 and 42 mg/l, respectively. Mild and transient diarrhoea was observed in 10% of patients. Laboratory side effects encountered were eosinophilia, thrombocytosis and neutropenia in another 8%. Ceftriaxone is a useful antibiotic for common childhood infections. Its prolonged half-life allows twice daily administration which reduces problems related to intravenous therapy as well as the cost and personnel time.

Adolescent↗
PubMed1983

Role of the ovary in the regulation of sex hormone binding globulin and its contribution to peripheral levels of androstenedione.

In order to assess the role of the ovary in the regulation of the levels of the sex-hormone-binding-globulin (SHBG) and its contribution to peripheral levels of androstenedione, three subject groups were studied: 10 normally menstruating women, 8 postmenopausic women, and 8 postmenopausic ovariectomized women. A basal venous blood sample was drawn between 8:00 to 9:00 h from all subjects in the latter two groups. The blood samples were drawn from the normally menstruating women on days 7, 14, 21 and 28 of their cycles. The following determinations were made in each sample: oestradiol, progesterone, testosterone, androstenedione SHBG, FSH and LH. It was concluded that: 1) SHBG does not vary during the menstrual cycle, nor there are significant differences between postmenopausic and castrated women, and 2) androstenedione levels in castrated women are significantly different from both postmenopausic and normally menstruating women.

Adult↗
PubMed1980

Immunoglobulin quantitation and enumeration of immunoglobulin-producing cells: comparison of two index of B-cell activation.

Human lymphocytes were cultured under different conditions to determine the effects of technical variations on the response to pokeweed mitogen (PWM) and Staphylococcus aureus as measured by (a) quantitation of immunoglobulins (Ig) in the culture supernatants and (b) enumeration of Ig-secreting cells (ISC) by a reverse plaque technique. The highest numbers of ISC were measured when the cells were cultivated in standing tubes, without glutamine supplementation during the culture, and at a concentration of 1 x 10(6) cells/ml. The highest Ig concentrations were measured under similar conditions, except that somewhat higher values were obtained with cell cultivated at 1 x 10(6)/ml in 2 ml cultures with PWM stimulation and 2.5 x 10(6)/ml in 1 ml cultures with S. aureus stimulation. In time-course studies, peak ISC responses occurred on day 5 with each mitogen, whereas extracellular Ig levels kept rising until day 7, possibly owing to accumulation of secreted Ig. Measurements of the numbers of ISC and of secreted Ig levels in simultaneous cultures of lymphocytes from the same donors showed no correlation; however, co-stimulation of cultures with PWM and concanavalin A (to stimulate suppressor cells) depressed both Ig levels and ISC numbers. These results suggest heterogeneity in the plaque-forming cell population with respect to rate of Ig secretion, but indicate that these two techniques both reflect B-cell activation. They should not, however, be considered interchangeable, and the two probably should be used in conjunction for complete characterization of B-cell activation.

Antibody-Producing Cells↗
PubMed1979

Evidence for the synthesis and release of strongly immunosuppressive, noncytotoxic substances by Streptococcus intermedius.

Products secreted by Streptococcus intermedius were studied for their effects on the immune response. Three different preparations of crude extracellular products from S. intermedius (CEP-Si) were found to have powerful suppressor activity in vitro as shown by inhibition of human lymphocyte proliferation (uptake of [3H]thymidine) and protein synthesis in response to a wide variety of stimulants, including mitogens and antigens, and suppression of plaque formation by human cells in response to sheep erythrocytes. CEP-Si was noncytotoxic, because cells incubated with high concentrations of CEP-Si and subsequently washed were viable and recovered their ability to respond to mitogens, and because leukocyte migration was not inhibited by CEP-Si, nor was the release of leukocyte migration inhibitory factor from sensitized lymphocytes. The possibility of antigen or mitogen competition was excluded. The effects of CEP-Si in vitro were time dependent and did not require the presence of monocytes. Cells pretreated with CEP-Si and then washed suppressed plaque formation by fresh autologous cells in highly stimulated cultures. CEP-Si injected into C57BL/6 mice also strongly suppressed their immune response to sheep erythrocytes, and the in vivo suppression was correlated with the effects of CEP-Si in vitro.

Animals↗
PubMed1971

Antigens of Bordetella pertussis V. Separation of Agglutinogen 1 and Mouse-Protective Antigen.

Agglutinogen 1 of Bordetella pertussis strain 353/Z (serotype 1) was separated from protective antigen and histamine-sensitizing factor by starch-block electrophoresis. Most of the agglutinogen 1 migrated towards the cathode in starch-block electrophoresis, although some remained near the origin. Fractions containing most of the agglutinogen 1 were free of detectable mouse-protecting or histamine-sensitizing activities. Agglutinogen 1 from a serotype 1, 3 B. pertussis strain (J20) migrated similarly to the agglutinogen 1 from strain 353/Z. All agglutinogen 3 activity was found at the point of application in the starch block. No clear relationship was found between agglutinogen 1 and mouse-protecting antigen or histamine-sensitizing factor.

Journal Article↗
PubMed1969

Histamine-sensitizing factor, mouse-protective antigens, and other antigens of some members of the genus Bordetella.

The three species of the genus Bordetella-B. pertussis, B. parapertussis, and B. bronchiseptica-have many antigens in common. Studies on representative strains of these species have shown that there are only a few specific antigens in each species. Whole-cell vaccines and extracts from B. pertussis contained specific mouse-protective antigen and a histamine-sensitizing factor. In addition, whole-cell vaccines and some saline extracts protected mice against intracranial challenge with B. bronchiseptica. Cells and a saline extract of B. parapertussis also protected against B. bronchiseptica but not against B. pertussis. Whole cells of B. bronchiseptica protected against B. bronchiseptica, but only one of three saline extracts protected against this challenge. Neither whole cells nor saline extracts from B. bronchiseptica protected against B. pertussis. The antigen in B. pertussis responsible for cross-protection against B. bronchiseptica was less resistant to heat than the protective antigen in B. bronchiseptica. Since histamine-sensitizing factor was not detected in B. bronchiseptica or B. parapertussis cells or extracts, this factor is not required to protect mice against B. bronchiseptica challenge. Whether B. pertussis vaccines protected against B. bronchiseptica by a nonspecific mechanism was not established, but it is clear that the specific antigen responsible for protection against B. pertussis was found only in B. pertussis and not in B. bronchiseptica or B. parapertussis.

Animals↗