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Biomedical subjects

J F James

Publications and source records attributed to J F James.

35 records · Page 2Linked to original sources
PubMed1978

Studies on gonococcus infection. XI. Comparison of in vivo and vitro association of Neisseria gonorrhoeae with human neutrophils.

The levels of association between Neisseria gonorrhoeae and neutrophils as determined by microscopic study of smears of urethral exudate from men with acute gonorrhea and by in vitro assay of N. gonorrhoeae cultivated from those same individuals showed statistically significant correlation. The percentage of N. gonorrhoeae attached to or ingested by neutrophils varied from 30% to 90% in the clinical smears. Neither the apparent in vivo nor the in vitro association with neutrophils could be correlated with piliation of the N. gonorrhoeae studied.

Gonorrhea↗
PubMed1978

Studies on gonococcus infection. XIII. Occurrence of color/opacity colonial variants in clinical cultures.

Colonial variants of Neisseria gonorrhoeae differing in color and opacity characteristics are distributed differently between male urethral and female cervical cultures. Colonial characteristics of cultures isolated from female cervices differ with time of isolation within the menstrual cycle and use of oral contraceptives. These differences may reflect selective forces in the ecology of the cervix, particularly proteolytic enzymes in cervical mucus and menstrual blood. Cycle changes in the characteristics of gonococci isolated from females may have implications for pathogenesis of gonococcal infections and immune response to the gonococcus.

Cervix Uteri↗
PubMed1977

The capsule of the gonococcus.

16 strains of Neisseria gonorrhoeae were subjected to several established techniques for capsule demonstration by light microscopy. In all strains examined, encapsulation of the gonococcus was demonstrated. Although the capsules were somewhat more easily seen in strains recently isolated from clinical material, organisms that had been passaged for several years also were encapsulated as were all the colony types within these strains. The gonococcal capsule is easily disrupted by mechanical forces.

Microscopy↗
PubMedDate not supplied

A nitrocellulose membrane based solid phase enzyme immunoassay for detecting polioviruses in stool.

An enzyme immunoassay was developed with nitrocellulose membrane as the solid phase support built in a 96 well porous polystyrene plate. Monoethanolamine was found to be a satisfactory and better blocking agent than skimmed milk. Up to 10(4.28) TCID50 poliovirus particles/0.1 ml of stool collected in 10% skimmed milk could be detected depending on the initial titer of the antigen specific capturing serum/IgG immobilized on nitrocellulose membrane. Percentage of skimmed milk in the transport medium, composition and pH of the dilution buffer and chloroform treatment of the stool specimens before the test were important determinants of the specificity of the test. Polyvinyl affinity membrane did not appear to be superior to nitrocellulose membrane as a solid phase support.

Antibodies, Viral↗
PubMedDate not supplied

Growth of toxic shock syndrome toxin 1-producing, tryptophan-requiring strains of Staphylococcus aureus associated with the presence of Escherichia coli.

More than 80 percent of TSST-1-positive strains of Staphylococcus aureus are tryptophan auxotrophs (Trp-). Chromosomal mapping has located the genetic determinant for TSST-1 (tst) in the trp operon for strain S411 (Trp-) and near the tyrB site for strain FRI1169 (Trp*). Auxonographic screening on tryptophan-free medium of 28 strains of S. aureus (TSST-1-positive and -negative, Trp+ and Trp-) against Escherichia coli (strains 6094, 7603, and 7877) and other strains of Enterobacteriaceae showed that Trp- S. aureus strains responded only to E. coli and tryptophan. Neither E. coli nor tryptophan inhibited TSST-1 production. Cocultivation of strain FRI1169 or S411 with E. coli strain 7877 showed that TSST-1 production by FRI1169 was not enhanced. In contrast, TSST-1 production by S411 was equal to that of S. aureus alone (less than 640 ng/mL) or enhanced (greater than 12,000 ng/mL) if the input log10 cfu of S. aureus was of equal or greater ratio to input E. coli and if the recovered S. aureus was greater than log10 5 cfu. These results suggest that nutritionally deficient toxicogenic strains of S. aureus may overcome growth limitation by coexisting in dynamic balance with strains of E. coli.

Bacterial Toxins↗
PubMedDate not supplied

Effect of magnesium on in vitro production of toxic shock syndrome toxin 1.

Batch and chemostat culture of Staphylococcus aureus strain S411 was conducted in an investigation of the role of Mg++ in the control of production of toxic shock syndrome toxin 1 (TSST-1). Under both growth conditions, Mg++ influenced bacterial growth, and TSST-1 production was correlated with bacterial growth. The specific activity of TSST-1 (ng/mg yield, ng/mg total protein) increased with increasing concentrations of Mg++ and was maximal at physiologic levels of Mg++. No production of TSST-1 was observed under anaerobic conditions. In chemostat cultures in which valine nutrient limitation was used with various levels of tryptophan in the chemically defined medium, tryptophan concentration controlled the production of TSST-1 by strain S411, regardless of the concentration of Mg++.

Aerobiosis↗
PubMedDate not supplied

Auxotypes and antibiotic susceptibilities of Neisseria gonorrhoeae from women with acute salpingitis. Comparison with gonococci causing uncomplicated genital tract infections in women.

An investigation of the MICs of various antibiotics and the nutritional requirements (auxotypes) of Neisseria gonorrhoeae recovered from the cervix, fallopian tubes, and peritoneal cavity of women with acute salpingitis was done. These MICs and auxotypes were compared to those of gonococci isolated from the cervix of women with uncomplicated or asymptomatic genital tract gonorrhea. The MICs of minocycline, penicillin G, ampicillin, cefoxitin, and cefaclor for gonococci isolated from women with acute salpingitis were significantly higher. Significant differences in auxotype patterns were identified between isolates from salpingitis cases and uncomplicated cases. The prototrophic form was the most common (75%) among salpingitis strains. No strains requiring arginine, hypoxanthine, and uracil were identified among the salpingitis isolates. In contrast, strains that required these nutrients were the most frequent auxotype among isolated from women with uncomplicated genital tract gonorrhea. Discriminant analysis revealed that the MIC of minocycline and the auxotype were the most powerful discriminators between groups of patients with different manifestations of gonorrhea.

Acute Disease↗
PubMedDate not supplied

Gonococcal attachment to eukaryotic cells.

The attachment of Neisseria gonorrhoeae to eukaryotic cells grown in tissue culture was analyzed by use of light and electron microscopy and by labeling of the bacteria with [3H]- and [14C]adenine. Isogenic piliated and nonpiliated N. gonorrhoeae from opaque and transparent colonies were studied. The results of light microscopy studies showed that the gonococci attached to cells of human origin, including Flow 2000, HeLa 229, and HEp 2. Studies using radiolabeled gonococci gave comparable results. Piliated N. gonorrhoeae usually attached in larger numbers than nonpiliated organisms, and those from opaque colonies attached more often than isogenic variants from transparent colonies. Day-to-day variation in rate of attachment was observed. Scanning electron microscopy studies showed the gonococcal attachment to be specific for microvilli of the host cells. It is concluded that more N. gonorrhoeae from opaque colonies, as compared with isogenic variants from transparent colonies, attach to eukaryotic cells grown in tissue culture.

Adenine↗