Gallium-67 Scans in the Diagnosis of Pyelonephritis

Gallium-67 (⁶⁷Ga) citrate was administered intravenously (50 microcuries per kg of body weight) to patients in whom acute and chronic urinary tract infections were suspected. Scanning was done, using both the Anger-type scintillation camera and the rectilinear scanner, 24 to 78 hours after injection of the isotope.The preliminary results imply that ⁶⁷Ga renal uptake is present in patients with pyelonephritis whether overt or silent, as well as in patients with uretero-sigmoidostomies. However, ⁶⁷Ga renal uptake is not present in patients with radiographic evidence of chronic pyelonephritis without active infection and in patients without renal disease.     

DORMANCY FACTORS IN IRIS (IRIDACEAE) SEEDS

Utilizing a newly developed radish seed bioassay, it has been demonstrated that Iris seed dormancy is caused by water-soluble inhibitor(s). Leached Iris seeds germinate freely when planted in soil without previous chilling. The inhibitor(s) can prevent germination of representative species of both monocotyledonous and dicotyledonous seeds.     

Determination of Antibiotic Susceptibility of Rickettsia by the Plaque Assay Technique

Plaque formation by various rickettsiae was completely inhibited by commercial antibiotic discs impregnated with tetracycline, chloramphenicol, nitrofurantoin, and erythromycin; partial inhibition was observed around discs containing nalidixic acid and sulfisoxazole, but no inhibition was seen around discs containing cephalothin, ampicillin, oxacillin, kanamycin, polymyxin B, streptomycin, or penicillin.     

Cell population density and phenotypic expression of tissue culture fibroblasts from heterozygotes of Lesch-Nyhan's disease (inosinate pyrophosphorylase deficiency)

Radioautographic examination of skin fibroblasts grown in tissue culture from normal donors revealed heavy labeling of almost all cells following incubation with tritiated hypoxanthine. Cells from patients with Lesch-Nyhan's disease, lacking inosinate pyrophosphorylase, had only 10 grains or less per cell. When normal and abnormal cells were mixed prior to culture, there was a progressive increase, with culture time, in the percentage of heavily labeled cells so that by 96 hr, when the cells were confluent, over 95% of the cells were heavily labeled. Reduction of cell density by subculture produced a reversion to original values. Cultures from three obligatory heterozygotes revealed the expected mixed population of cells. This appears to be a practical approach to the identification of the heterozygote.Aided by USPHS CA08748 and GM15508, and the Health Research Council of the City of New York.     

Effect of the Route of Inoculation on Antibody Formation in Guinea Pigs Immunized with Parainfluenza Virus Vaccines

The efficiency of the intramuscular route of immunization of guinea pigs was compared with the intraperitoneal route when trivalent parainfluenza virus vaccine was employed as immunogen. When the routes of immunization were compared by effective dose 50, the intramuscular route was more effective. Likewise, a statistical evaluation of conversion rates and of titers revealed significantly higher values for the intramuscular than for the intraperitoneal route to all three components in two of the lots of vaccine tested.     

Interaction of the exr and lon Genes in Escherichia coli

Strains of Escherichia coli carrying the gene lon typically produced excess capsular polysaccharide, and were sensitive to ultraviolet light (UV) irradiation, thymine starvation, and nalidixic acid, forming long filaments after these treatments. Sensitivity was reduced by a number of posttreatments. In the presence of a second UV sensitivity gene, exr, some of these properties were suppressed: long filaments were not formed, the effect of lon on UV and nalidixic acid sensitivity was greatly reduced, and irradiation posttreatments gave an enhancement of survival characteristic of exr rather than lon strains. Production of capsular polysaccharide was not affected by the exr gene.     

Effects of Ionizing Radiation on Synchronous Cultures of Escherichia coli B/r

The sensitivity of Escherichia coli B/r to X-irradiation is correlated with the replication cycle of deoxyribonucleic acid (DNA). The sensitivity to X-irradiation in the wild type can be attributed to the presence of nuclear targets plus DNA repair mechanisms. The effects of nuclear targets are observed in the recombination-deficient (rec−) mutant B/r, but the sensitivity reflected by changes in the slope of killing curves is absent. A study of different growth conditions indicates that maximal resistance to X rays occurs toward the middle of the division cycle. Evidence is offered that branched chromosomes respond as one-hit targets to X-irradiation. The killing effects of heavy-ion bombardment on E. coli are due primarily to ionizing radiation.     

Structural and immunological studies on the protoplast membrane of the yeast Candida utilis

Cell membranes of the yeast Candida utilis isolated by lysis of protoplasts have been shown to be lipoprotein in nature. Electron microscopy shows that Mg⁺⁺ is responsible for maintaining the integrity of the membrane. A close serological relationship was found between membranes and cell walls isolated from the yeast. This relationship was exhibited not only by membranes obtained by strepzyme treatment but also by those obtained from the action of helicase enzyme. No such relationship existed between membranes and whole cells. Related data have been obtained by treatment of yeasts with different digestive enzymes. All of the results suggest that the protoplast membrane possesses traces of structural cell wall material. This material is detectable by serological tests, but not by electron microscopy.     

Influence of Relative Humidity on the Survival of Some Airborne Viruses

A system for studying the effects of relative humidity (RH) and temperature on biological aerosols, utilizing a modified toroid for a static aerosol chamber, is described. Studies were conducted at 23 C and at three RH levels (10, 35, and 90%) with four viruses (Newcastle disease virus, infectious bovine rhinotracheitis virus, vesicular stomatitis virus, and Escherichia coli B T3 bacteriophage). Virus loss on aerosol generation was consistently lower at 90% than at 10 or 35% RH. When stored at 23 C, Newcastle disease virus and vesicular stomatitis virus survived best at 10% RH. Infectious bovine rhinotracheitis virus and E. coli B T3 bacteriophage survived storage at 23 C best at 90% RH.