Merrill G. Wheatcroft

Long-term observations of radiation changes in salivary glands and the general effects of 1,000 R. to 1,750 R. of x-ray radiation locally administered to the heads of dogs.

Abstract Considerable morphologic alteration was observed in the salivary glands of dogs which had received 1,750 r. of 200 kv. x-ray radiation locally to the head. From a total of six dogs which were irradiated, five were sacrificed during a five- to sixteen-month period following exposure and provided the experimental material for histologic study. Normal glands were obtained from seven unirradiated dogs for comparison. Several special fixatives and stains were used in order to adequately observes the nuclei, mitochondria, connective tissue, and various cellular products of the salivary glands. The parotid, submaxillary, and sublingual glands of three dogs which received 1,750 r. and were sacrificed twenty-five, twenty-nine, and thirty-four weeks later were atrophied, fibrosed, and altered in morphologic detail. Except for knowledge of the anatomic areas from which the tissues were taken, or by special staining reactions, it would have been impossible to identify many tissue sections. The severe changes consisted in various grades of obliteration of acini, leaving whorls of nuclei in streaked concentric patterns, fragmented cells, groups of cells without pattern, partly damaged acini in which one or two cells were identifiable and the rest were vacuolated or in signet-ring configuration. A dog receiving the same amount of treatment, which was sacrificed fifty-eight weeks afterward, had much less apparent total damage, but in many areas some of the changes described previously could be found. A dog receiving 1,000 r. and sacrificed sixty-eight weeks afterward had relatively normal-appearing salivary glands. The general changes observed were stomatitis, surface sloughing, and oral hemorrhage in mild to moderate degree, erythema of exposed areas, particularly over the ears and around the eyes, and epilation. Hair grew back in after six to twelve weeks and was light gray in color. Dogs appeared to be moderately distressed after treatment and one animal developed an ulcerating lesion of the neck.

Clinical and Materials Sciences The Effect of Skylab on the Chemical Composition of Saliva

The levels of specific proteins and electrolytes in stimulated whole saliva were monitored in Skylab crew members before and after each mission. With few exceptions, mission-associated compositional changes in saliva were relatively minimal. There were no changes in Ca++, K+, PO≡ 4, Cl-, albumin, or IgG concentrntions. There were slight decreases in total protein coinciding with moderate saliva flow rate increases iminediately before and after each flight. Other changes included diminutions in Na+ and lysozyme, and elevations in Mg++ and IgA. The IgA increase was the most pronounced mission-associated change observed.

Effects of a Simulated Skylab Mission on the Oral Health of Astronauts

Laboratory and clinical findings related to the oral tissues of three astronauts during a 56-day simulated Skylab mission are described. Changes in the oral counts of specific microorganisms were observed concurrently with alterations in saliva flow rates and levels of secretory IgA and salivary lysozyme.

Oral Microbial Profile of the Marmoset

Qualitative and quantitative assessments were made of the cultivable oral microflora of adult marmosets that were given three difjerent dietary regimens. The identifiable isolates were dispersed among 12 recognized microbial families, 24 genera, and more than 40 species. Generally, marmosets that received a high sucrose diet had the highest bacterial counts.

Hypobaric Chamber for Oral Flora Study in Simulated Spacecraft Environment

A chamber to house two marmosets in a space-simulated environment was built and tested. The chamber was used in three experiments of two weeks duration each to study changes in the oral microflora of marmosets exposed to an atmosphere of 70% oxygen and 30% nitrogen at 5 psi.

Effects of a simulated spacecraft environment on the oral microflora of nonhuman primates

Abstract As part of a program to determine the personal oral hygiene requirements for extended space missions, adult marmosets were maintained in a hypobaric chamber with an atmosphere of 70 per cent O 2 and 30 per cent N 2 at 5 p.s.i. for periods up to 56 days. The marmoset oral microflora was monitored immediately before, during, and after repeated chamber trials. The marmosets adjusted to the space-simulated environment with relatively few problems, except for loss of weight and diarrhea. There were no apparent environment-associated oral tissue changes, qualitative microbial changes, or oral transmission of microorganisms between pairs of chamberhoused animals. There were, however, environment-associated quantitative microbial changes which were animal-related and which were inconsistent with regard to type of microorganism, type of oral specimen, and duration of chamber exposure.

Effect of the Diffusion of Microbial Growth Factors Through Tooth Substance on Production of Carious Lesions in Vitro

SYNOPSIS IN INTERLINGUA LE EFFECTO DEL DIFFUSION DE FACTORES DE CRESCENTIA MICROBIAL A TRANSERVSO LE SUBSTANTIA DEL DENTE SUPER LE PRODUCTION DE LESIONES CARIOSE IN VlTRO.—Le presente studio testava le hypothese que certe nutrientes essential pro le subsistentia de micro-organismos cariogenic es obtenite ab liquidos dentinal. Extrahite dentes esseva montate individualmente in tubos de diffusion construite de maniera a assecurar un barriera hermetic inter un medio de cultura nutritionalmente carente que coperiva le coronas e solutiones de factores de crescentia in que le radices esseva immergite. Varie factores de crescentia diffundeva a transverso le dentes in quantitates sufficiente a supportar crescentia microbial le qual, de su parte, produceva lesiones que non esseva distingubile ab carie clinic. Lamellas de adamante provideva vias specific pro le ingression de micro-organismos.

Study of Cornification of Oral Epithelium by Phase Microscopy

Smears of oral epithelial cells from 20 male students were compared by phase microscopy and by the Papanicotaou technic to determine degrees of cornification. Cell size and numbers of nucleated and nonnucleated cells were dependable criteria for determining degrees of cornification by phase microscopy.