Secretory IgA in Urinary Tract Infections

Secretory IgA, measured by radial immunodiffusion, was compared in the urine of children with chronic and recurrent non-obstructive urinary tract infections with that in normal children. IgA, IgG, and IgM were also measured. Absent and low levels of IgA(s) were found in both groups; however, the mean levels of IgA(s) were significantly higher in the infected group compared with normals—3·3 to 0·78 mg./24 hours, respectively. Secretory IgA was found to be locally produced in the bladder. It is suggested that IgA(s) levels reflect an antibody response to infection.     

Effects of a Single Histoplasmin Skin Test on the Serological Diagnosis of Histoplasmosis

Numerous reports have indicated that a single histoplasmin skin test may stimulate humoral antibodies to Histoplasma capsulatum antigens in histoplasmin-hypersensitive individuals. Although these investigations concur that antibody elevations are evoked, they vary in the reported degree of incidence and response induced, and they cast doubt on the interpretation of serological tests in the diagnosis of histoplasmosis. Histoplasmin-hypersensitive subjects (114) were bled prior to administration of the skin test, 2 days later, at the time this test was read, and 15 and 30 days after testing. No significant antibody titers were observed at 2 days. At 15- and 30-day intervals, only 17 (15%) of the subjects demonstrated circulating antibodies. All 17 showed agar gel bands; 5 demonstrated no complement-fixation (CF) titers, 10 produced CF antibodies ranging from 1:8 to 1:16, and 2 demonstrated titers of 1:32. The data suggest that skin testing does not interfere significantly with antibody levels in sera drawn approximately 2 days after administration of antigen. However, since titers as high as 1:32 were obtained at later intervals, such reactions should be evaluated cautiously and only after consideration of clinical findings.     

Ultrastructural and histochemical changes in the murine zona pellucida during the final stages of oocyte maturation prior to ovulation

The ultrastructural morphology of the mouse zona pellucida was studied in preovulatory follicles from the ovaries of immature mice treated with exogenous gonadotrophins. The ovaries were fixed in the presence of cetylpyridinium chloride, which precipitates carbohydrates, so that their loss during fixation and processing is substantially reduced. The semi-thin araldite sections obtained from osmicated material were viewed by conventional light microscopy, while the ultra-thin sections were examined by transmission electron microscopy. A parallel series of semi-thin sections of non-osmicated ovaries was deresined and subsequently stained with periodic acid Schiff (PAS). The morphological appearance of the zona pellucida in preovulatory oocytes changed during the final stages of oocyte maturation. A close correlation was observed between the ultrastructural appearance of the zona pellucida and that observed following PAS staining during the period studied. Real differences were observed in the location, density, and distribution of glycoconjugates within the zona pellucida during the final stages of oocyte maturation prior to and immediately following germinal vesicle breakdown. Similar changes in the zona were observed in adult females autopsied during proestrus and oestrus. The changes in the density and distribution of glycoconjugates are likely to have important consequences for fertilization by affecting sperm-zona binding and sperm-egg interactions.