A submucosal mass in the floor of the mouth.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to R Mack.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Sociological research on the disabled has for the past 25 years made extensive use of a social deviance model to characterize the status of the physically impaired. The present article, which is based on a three-year anthropological investigation of the social relations of paraplegics and quadriplegics in the New York metropolitan area, argues that there are shortcomings in the deviance model and offers, instead, a model taken from the anthropological study of ritual. The disabled are viewed as being in a 'liminal' state, as in the liminal phases of rites of passages. They are persons having an undefined status: they are neither ill nor well, neither socially alive and active nor socially expunged and removed. The status of the disabled in American society and the symbolism of disability in American culture are reexamined within this framework. This perspective is extended to other types of deep adversity, such as acute loss of income and status or catastrophic illness.
A sequential staining protocol for revealing first G- and then R-bands on early metaphase chromosomes is presented. Lymphocyte cultures are synchronized with methotrexate, and released from the S-phase block with bromodeoxyuridine. The resulting early metaphase cells are initially G-banded with Wright's stain and then R-banded by the fluorescence plus Giemsa (FPG) technique.
A facility was established for long-duration ultraviolet (UV) radiation exposure of natural and synthetic materials in order to test hypotheses concerning Martian soil chemistry observed by the Viking Mars landers. The system utilized a 2500 watt xenon lamp as the radiation source, with the beam passing through a heat-dissipating water filter before impinging upon an exposure chamber containing the samples to be irradiated. The chamber was designed to allow for continuous tumbling of the samples, maintenance of temperatures below 0 degrees C during exposure, and monitoring of beam intensity. The facility also provided for sample preparation under a variety of atmospheric conditions, in addition to the Mars nominal. As many as 33 sealed sample ampules have been irradiated in a single exposure. Over 100 samples have been irradiated for approximately 100 to 700 h. The facility has performed well in providing continuous UV irradiation of multiple samples for long periods of time under simulated Mars atmospheric and thermal conditions.
The chemical reactivity of several minerals thought to be present in Martian fines is tested with respect to gases known in the Martian atmosphere. In these experiments, liquid water is excluded from the system, environmental temperatures are maintained below 0 degrees C, and the solar illumination spectrum is stimulated in the visible and UV using a Xenon arc lamp. Reactions are detected by mass spectrometric analysis of the gas phase over solid samples. No reactions were detected for Mars nominal gas over sulfates, nitrates, chloride, nontronite clay, or magnetitie. Oxidation was not observed for basaltic glass, nontronite, and magnetite. However, experiments incorporating SO2 gas--an expected product of volcanism and intrusive volatile release--gave positive results. Displacement of CO2 by SO2 occurred in all four carbonates tested. These reactions are catalyzed by irradiation with the solar simulator. A calcium nitrate hydrate released NO2 in the presence of SO2. These results have implications for cycling of atmospheric CO2, H2O, and N2 through the regolith.
A method for the quantitative determination of carbaryl insecticide by in situ densitometry was developed. After separation on silica gel thin layer plates, carbaryl residues were detected by using p-nitrobenzenediazonium fluoborate reagent and quantitated by scanning the resultant blue spots with a fiber optics densitometer and comparing them with standards. The method was applied to water fortified with carbaryl at 8 ppb and apples and lettuce fortified at 0.10 ppm; all recoveries were greater than 89%. The 2 crop extracts were cleaned up by using the AOAC thin layer chromatographic method for visual estimation of carbaryl. Related carbamate insecticides were detected by using the same reagent, and the potential for quantitation was demonstrated.
Untreated red cells of the Bombay variant Amh have traces of A. They are Le(b)-positive but H-negative. Following RDE-(Receptor destroying enzyme) treatment H is demonstrable by anti-HLa, -BHEe, and -HUe but not by anti-HLt. This type of reaction resembles that in O-newborns: H is present only in the form of a glycolipoid but not in the form of a mucoid. The barrier of neuraminic acid prevents recognition of H as his own. Anti-H is present. It has been shown that H as a precursor is necessary only for A1 but not for Am, A3, and A2.
A new type of self-retaining dry metal electrode for the electrocardiogram (ECG) is described which adheres to the skin by the application of negative pressure to an annulus surrounding the electrode, which is a bare silver. Data are presented for the factors which govern the adherence to the skin and the range of initial impedance and the values obtained at 2, 5, 10 and 20 minutes and with tap water under the electrodes. The initial impedance is usually high (0.18 to 10 megohms) and decreases progressively with time. Tap water placed under the electrodes dramatically reduces the initial range of impedance. Such electrodes, when used with an amplifier with an adequately high input impedance, can be used for recording electrocardiograms in a variety of situations.
A crossover experimental design was used to examine the effects of saline (SAL) vs. taurocholate (TC) infusion on hepatic excretory function in isolated perfused livers from pregnant (19-21 days gestation) and nonpregnant female rats. Bile flow, bile acid concentration, bile acid secretory rate, dibromosulfophthalein (DBSP) concentration in bile, and DBSP secretory rates were determined in livers infused continuously with DBSP and initially with SAL (1 ml/hr, 45 min), followed by TC (60 mumol/hr, 1 ml/hr; 75 min) or initially with TC (45 min) followed by SAL (75 min). The order of infusion (SAL-TC vs. TC-SAL) had no significant effect. TC infusion significantly increased all measures in livers from both nonpregnant and pregnant rats. Two-way analysis of variance followed by the Tukey-Kramer test showed that bile flow (microliter/min/g liver) and DBSP concentration in bile (mumol/ml) were significantly decreased during SAL infusions in pregnancy. These two measures plus bile acid and DBSP secretory rates (nmol/min/g liver) were also significantly decreased during TC infusion in pregnancy. Pregnancy had no effect on bile acid concentration in the presence of SAL or TC infusions. When bile flow, bile acid, and DBSP secretory rates were calculated per whole liver, only the DBSP secretory rate was significantly decreased in pregnancy. These data indicate that bile flow and bile acid secretion do not increase in proportion to the increase in liver weight in pregnancy so that these measures are decreased when expressed per g liver. Pregnancy appears to have a real inhibitory effect on DBSP since its secretion is depressed when activity is expressed per g liver or per whole organ.