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Biomedical subjects

G L Gitnick

Publications and source records attributed to G L Gitnick.

71 records · Page 4Linked to original sources
PubMed1971

Maternal and neonatal Australia antigen.

Four hundred and fourteen pairs of maternal and cord blood specimens from a county hospital population in southern California were assayed for Australia antigen by complement fixation and immunodiffusion techniques. Four maternal specimens were found to be positive (1 percent). One of the mothers with positive reaction was ill with viral hepatitis at time of delivery. Three had no evidence of symptomatic liver disease during pregnancy; two were born and raised where the prevalence of Australia antigen (Au(1)) is higher than in the United States. Although none of the cord blood specimens were positive for Au(1), one infant whose mother had Au(1) at delivery became positive at one month of age, and positive titers have persisted through 12 months of life. The significance of chronic Au(1) antigenemia in this infant is uncertain. However, it may be of importance in understanding the pathogenesis of viral hepatitis in the neonatal period.

Blood↗
PubMed1969

Immunosuppressive activity of concanavalin A.

Two strains of mice (C-57 B] and DBA) were given skin allografts from Swiss ICR/HA mice and were treated with varying doses of concanavalin A; the dosage ranged from only two injections of 25 micrograms during the experiment to daily doses of 1000 micrograms intraperitoneally. Immullosuppression was present at all dosages, the most prolonged and consistent effect being observed at 300 micrograms per day. Grafts survived for 14 to 21 days at this dosage compared to 4 to 9 days for controls.

Animals↗
PubMed1968

An improved diluent for rubella hemagglutination and hemagglutination-inhibition tests.

Rubella hemagglutinating (HA) antigen was prepared in BHK-21 tissue as 5% cell suspensions and from unconcentrated and 20x concentrated infected supernatant fluids. In some instances, unconcentrated fluids were treated with Tween 80 and ether; cell suspensions were treated with ether alone. Preparations were tested for HA activity in dextrose-gelatin-Veronal (DGV) buffer solutions; 0.85% NaCl; Sorenson's phosphate-buffered saline, pH 7.2; and a diluent of 0.9% NaCl, 0.1% CaCl(2) (anhydrous), and 0.1% MgSO(4).7H(2)O. HA titers were consistently two- to fourfold higher in the saline with added Ca(++) and Mg(++) than in DGV. Hemagglutination-inhibition titers of paired human sera were the same in either diluent. It is suggested that the interaction between rubella HA antigen and the red cells of young (less than 1-day-old) chicks may be at least partially ion dependent and that titers are enhanced by increased quantities of divalent cations.

Animals↗
PubMed1967

Rubella virus: continuous and concurrent production of complement-fixing antigen and infectious virus in suspension cultures.

Rubella complement-fixing (CF) antigen and infectious virus were produced continuously and concurrently for as long as 63 days in suspension cultures of BHK-21 cells prepared from uncloned monolayer stock cultures. CF titers ranged from 1:4 to 1:32, and the peak infectivity titer was greater than 8.0 (TCID(50) log(10)) per ml. Suspension cultures could be recultivated after prolonged storage in liquid nitrogen. The resulting monolayer or suspension cultures also produced CF antigen. Suspension cultures provide an effective system for the long-term continuous and concurrent production of rubella virus diagnostic reagents.

Animals↗
PubMed1967

Production of rubella hemagglutinating antigen in suspension cultures.

Rubella virus specific hemagglutinating antigen was prepared in the fluid phase of suspension cultures. Systems employing baby hamster kidney culture adapted inocula, nonadapted inocula, and cells derived from long-term infected suspension cultures were evaluated. Optimal specific hemagglutinating titers were obtained when kaolin-treated fetal bovine serum was used in the media and when the incoulum had previously been adapted in a suspension culture system. When cultures derived from long-term infected suspension systems were studied, the number of daily harvests in which acceptable titers were present was prolonged. However, titers were generally higher in suspension systems employing cells which had recently been infected.

Animals↗
PubMedDate not supplied

Hepatitis B vaccine: low postvaccination immunity in hospital personnel given gluteal injections.

Although other investigators have found excellent response rates to the hepatitis B vaccine, we report here an unusually low rate of seroconversion following hepatitis B vaccination in a group of apparently healthy medical center personnel. Only 67% of these individuals developed adequate postvaccination antibodies to HBsAg, in contrast to 85 to 96% in other studies. A significant decrease in seroconversion with increasing age was noted with a 54% seroconversion rate in vaccines over the age of 40; all of whom had received gluteal injections. Employees at another facility had been given deltoid injections from the same vaccine lot and had an overall seroconversion rate of 90%. Subsequently, nonresponders from the first group were revaccinated. Seven of the ten individuals tested developed anti-HBs. We believe the relatively low rate of seroconversion in individuals above the age of 40 may have been related to gluteal injection of the hepatitis B vaccine, and further investigation is warranted.

Adult↗
PubMedDate not supplied

Transplantation of hepatitis B surface antigen positive bone marrow.

We considered for bone marrow transplantation a boy whose only histocompatible donor was positive for hepatitis B surface antigen (HBsAg). He was conditioned for transplantation with cyclophosphamide and total body irradiation. Hepatitis hyperimmune gamma globulin was administered following the bone marrow infusion. Fourteen months after transplantation, the recipient remains a chronic HBsAg carrier, but he has neither developed fulminant liver disease nor has there been any evidence of graft failure.

Adolescent↗