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The roles of vitamin C and the effects of supplementation have been under investigation for many years. The purpose of this study was to use high performance liquid chromatography to assess the presence of vitamin C in human sweat, to evaluate sweat as a possible excretory route for vitamin C and to note any effects of vitamin C supplementation. Vitamin C in sweat was determined in samples from 10 active men and women prior to supplementation and weekly for 4 consecutive weeks as the vitamin C supplements were with a reverse-phase liquid chromatograph (Model ALC-202) equipped with a solvent delivery system (Model 6000, Waters Association).The presence of vitamin C in sweat samples was indicated by comparing peaks to those seen with vitamin C observed in sweat samples. Vitamin C was observed in sweat at the end of the first week of supplementation. The pres C.However, 4 and 5 when standards. During the first week of the study, when subjects' diets were not supplemented, vitamin C was not observed in sweat samples. Vitamin C was observed in sweat at the end of the first week o supplementation. The presence of vitamin C in sweat diminished during weeks 4 and 5 when intakes were supplemented with 750 mg and 1000 mg, respectively. It appeared that supplementation affected the presence of vitamin C in human sweat until plasma or tissues were saturated, at which point absorption may have decreased and other means of excretion may have been enhanced.

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Anderson and Putnam, and Kellendonk discovered methods of defining a C*- algebra on a noncommutative space associated with a tiling. The method employed was to use Renault's theory of groupoid C*-algebras of an equivalence relation on the tiling metric space. C*-algebras of a tiling have two purposes, on one hand they reveal information about the long range order of the tiling and on the other hand they provide interesting examples of C*-algebras. However, the two constructions do not include tilings such as the pinwheel tiling, with tiles appearing in an infinite number of orientations. We rectify this deficiency, with many interesting results appearing in the process.

Oxygen availability is critical for survival for most organisms. The nematode, C. elegans, has been useful for studying genetic regulation of anoxia tolerance due to the oxygen deprivation response mechanisms shared with other metazoans. Studies examining long-term anoxia (72h, LTA) tolerance have only been conducted at adult day 1. To investigate the effect of aging on anoxia tolerance wild-type and mutant strains were exposed to LTA between adult day 1 and day 9. Wild-type isolates and daf-16(mu86) (FOXO transcription factor regulated by insulin-signaling) and aak-2(gt33) (catalytic subunit of AMP-activated protein kinase) strains were anoxia sensitive at day 1 and displayed increased LTA tolerance with aging correlated with reproductive senescence followed by a decline in survivorhsip through day 9. The daf-2(e1370) (insulin receptor homologue of C. elegans), glp-1(e2141) (a lin-12/Notch receptor) and fog-2(q71) (required for spermatogenesis) strains were LTA-tolerant through day 5. I conclude that aging influences LTA-tolerance in a strain- and age-dependent manner. In addition to being LTA-tolerant the daf-2(e1370) and glp-1(e2141) strains have a longevity phenotype that is suppressed by loss of kri-1 or daf-12. While loss of kri-1 did not suppress the LTA-tolerant phenotype of glp-1(e2141) at day 1 the portion of impaired survivors increased at day 3 and by day 5 tolerance was suppressed. Similarly, when exposed to 4 days of anoxia the glp-1(e2141);daf-12(rh41rh611) double mutant had a reduced survivor rate at all ages analyzed compared to glp-1(e2141) controls. To better understand formation of an anoxia-tolerant physiology I exposed adults to one or more 24h bouts. Recurrent bouts increased LTA tolerance in wild-type hermaphrodites in a dose-dependent manner. Bout-treated daf-16(mu86) animals had increased survival rate compared to controls yet maximum survival remained below age-matched wild-type. Anoxia bouts decreased LTA-tolerance in aak-2(gt33) mutants, indicating the requirement for ATP regulation in establishing an LTA-tolerant phenotype. These data support the idea that anoxia tolerance is multi-factorial and influenced by environment, metabolism, food, reproduction, sex phenotype and likely additional factors.

La hepatitis C en hemodiálisis es un problema de salud que no ha sido estudiado a largo plazo en el hospital Alberto Sabogal Sologuren, por lo cual decidí realizar un estudio seroepidemiológico de la hepatitis C, de tipo prospectivo, descriptivo y trasversal, en la Unidad de Hemodiálisis, entre los meses de enero y mayo del 2,002, al considerársele a esta patología como la complicación hepática más frecuente a largo plazo entre los pacientes en hemodiálisis, para así poder conocer nuestra realidad y compararla con la de otros países para intercambiar información y lograr una mejora mutua. Durante el lapso de estudio, se presentaron 89 pacientes con IRCT en programa de hemodiálisis. Se encontró una prevalencia de la hepatitis C del 63% (N° 56 pacientes) y una incidencia del 17%, con una tasa de seroconversión del 0.64%. Teniendo en cuenta el tiempo de permanencia de 90 días en hemodiálisis, la prevalencia fue del 58% y la incidencia del 12%. La tasa de seroconversión fue 0.51%. Fueron cuatro pacientes los que tenía menos de 90 días de recibir terapia de reemplazo de la función renal a través de la hemodiálisis, todos ellos presentaron seroconversión durante el estudio. Las causas más frecuentes de IRCT en los pacientes con hepatitis C en orden de frecuencia fueron: la diabetes mellitus, la hipertensión arterial, glomerulonefritis difusa crónica y las uropatías obstructivas. El tiempo promedio en hemodiálisis entre los pacientes con hepatitis C fue de 42.5 meses. El promedio de edad fue de 59 años (24 a 82 años). El 61% de los pacientes con hepatitis C fueron mujeres y el 39% varones. Los factores de riesgo importantes en esta población estuvieron dados, por la creación del acceso vascular (100%), los procedimientos odontológicos (89%), las transfusiones sanguíneas (86%), la promiscuidad heterosexual (88%). Antecedentes familiares de hepatopatía viral (82%). Dada la alta prevalencia e incidencia de hepatitis C en la Unidad de Hemodiálisis del Hospital Sabogal, y conociendo los factores de riesgo, es necesario reforzar las normas de bioseguridad existentes, para evitar la transmisión de dicha infección por la vía horizontal y por productos hemáticos a los pacientes con IRCT en hemodiálisis que no tienen hepatitis C, al personal de salud y a los familiares de los pacientes con hepatitis C.