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Biomedical subjects

E L Murphy

Publications and source records attributed to E L Murphy.

89 records · Page 5Linked to original sources
PubMed1988

Human immunodeficiency virus and human T-lymphotropic virus type I infection among homosexual men in Kingston, Jamaica.

From August 1985 through January 1986, 125 homosexual or bisexual men from the Kingston area were enrolled in a study to evaluate risk factors for infection with human immunodeficiency virus (HIV) and human T-lymphotropic virus type I (HTLV-I). Twelve men (10%) were seropositive for HIV and 6 (5%) for HTLV-I; 1 man had possible coinfection with HIV and HTLV-I. One third of the men reported having had homosexual encounters with foreign visitors or while travelling outside Jamaica, and sexual contact with men in the U.S. was weakly associated with HIV infection (p = 0.11). The median number of partners was 12 per year (range 0-135) and a greater number of homosexual partners per year was associated with HIV seropositivity (p = 0.01). HIV seropositives also were more likely to have a history of lymphadenopathy (p = 0.07). For HTLV-I, there were no obvious risk factors identified, and age-adjusted seroprevalence was not significantly higher than that of heterosexual men. Compared to studies of homosexual men in the U.S. prior to the advent of extensive AIDS education, the Jamaican homosexual population was more sexually conservative. Despite this circumstance, HIV appears to have entered this population via sexual contact with foreign men and spread efficiently among men with a greater number of sexual partners. The frequency of bisexuality (65/125 men) and the 11% HIV prevalence in bisexual men suggest that secondary infection of female sexual partners may occur.

Acquired Immunodeficiency Syndrome↗
PubMed1978

Quantifying fatigue in working divers.

Thirty professional divers involved in training, bounce dives, working saturations, and deep experimental saturations were observed over a 1-month period. The subjects themselves performed simple twice-daily measurements of oral temperature, heart rate, breathhold time, handgrip strength, length and quality of sleep, and a subjective estimation of fatigue. The data were analysed with respect to the type of work done by the diver, separating diving from nondiving days. The results showed that subjective estimation of fatigue corresponded to the increment of evening oral temperature and heart rate over morning values. Both inspiratory and expiratory breathhold times decreased from morning to evening in those situations deemed most tiring by the divers. Sleep was generally of average duration and quality; however, diving during the daytime was associated with a decreased amount of sleep in the 24-h period including the following night. Sleep was also of poorer quality during periods of saturation diving. In addition to such group variations, individual divers showed significant performance changes on the various tests, demonstrating the value of this approach to the practical question of deciding when a man is too tired to dive safely. Extension of this method can, we hope, aid in the definition of safe working rotations for professional divers.

Adult↗
PubMed1977

Heart rate and core temperature as indicators of heat stress during deep underwater activity.

In hyperbaric environments, comfortable ambient temperatures are necessarily higher than normal room temperature, and high levels of humidity are also common. These conditions are stressful and even hazardous for an exercising diver. We monitored the heart rates and core temperatures of divers participating in deep experimental dives to pressures up to 300 msw. Accelerated heart rates (100 to 180 beats/min) and elevated core temperatures (+0.4 to 0.9 degrees C) were registered. The increase in heart rate can be explained by the rise in core temperature. Formulas are presented for the relationships between heart rate and duration of activity, between core temperature and duration of activity, and between heart rate and core temperature. These formulas allow the estimation of core temperature from the diver's pulse, and serve to prevent excessive heat stress which could lead to an accident.

Body Temperature↗
PubMed1976

Longitudinal study of performance after deep compressions with heliox and He-N2-O2.

This study concerns three hyperbaric experiments. During SAGITTAIRE iv, compression to 610 msw was accomplished in 11 days with an atmosphere of helium-oxygen. For the two CORAZ experiments, compression to 300 msw was done in 4 hours with He-N2-O2 trimix, varying nitrogen concentration from CORAZI (2.8 ATA N2 =9%) to CORAZ II (1.4 ATA N2=4.5%). Oxygen partial pressure was always maintained at 0.4 ATA except during decompression. The same two subjects participated in all three experiments and underwent the following psychometric tests: manual dexterity, visual choice-reaction time, and number ordination. Results show a large decrement in performance at 610 msw after slow compression (-50% and -47% on the number ordination test, -34% and -24% on the visual choice-reaction time). Test performance was less affected after the rapid compressions to 300 msw, and recuperation to control values occurred within 1 day at 300 msw. Our data show that 1.4 ATA N2 is less detrimental to performance than 2.8 ATA N2 for trimix compressions to 300 msw in 4 hours.

Adaptation, Physiological↗
PubMed1969

Intestinal hydrogen and methane of men fed space diet.

Intestinal bacteria form two gases, hydrogen (H2) and methane (CH4), that could constitute a fire hazard in a closed chamber. So H2 and CH4 pass from the anus but these gases are also transported by the blood to the lungs and removed to the atmosphere. Several factors affect gas formation: 1) amount and kind of fermentable substrate; 2) abundance, types, and location of microflora; and 3) psychic and somatic conditions that affect the gut. We evaluated the first factor by studying men fed different diets and have also recorded influences of uncontrollable factors. One group of 6 men ate Gemini-type diet (S) and another received a bland formula (F), for 42 days. Breath and rectal gases were analyzed during the first and final weeks. Flatus gases varied widely within dietary groups but much more gas was generated with diet S than with F. In the first 12-hour collection, subjects fed S passed 3 to 209 ml (ATAP) of rectal H2 (avg 52) and 24 to 156 ml (avg 69) from the lungs (assuming normal pulmonary ventilation). With F, these values were 0 to 3 ml (avg 1) and 6 to 36 ml (avg 20). Subjects were calmer during the second test. Gas production was lower with S than initially; F values were unchanged. Methane differed idiosyncratically, presumably due to differences in flora. Computed from 12-hour values, maximum potential daily H2 and CH4 are per man: for S, 730 ml and 382 ml; for F, 80 and 222 ml. Volumes would be larger at reduced spacecraft and suit pressures.

Bacteria↗
PubMedDate not supplied

Psychological distress in blood donors notified of HTLV-I/II infection. Retrovirus Epidemiology Donor Study.

BACKGROUND: Blood donations in the United States have been screened for antibody to human T-cell lymphotropic virus types I and II (HTLV-I/II) since November 1988. Although clinically diagnosed illness associated with HTLV-I/II remains relatively uncommon, blood donors notified of HTLV infection frequently report negative psychological and social effects following notification. STUDY DESIGN AND METHODS: To assess psychological outcomes, the General Well-Being Scale, a standardized 18-item questionnaire, was administered to 464 HTLV-I/II-positive donors and 91 sex partners at five blood centers in the United States following notification of HTLV-I/II infection. The questionnaire was also given to 735 HTLV-I/II-negative donors. RESULTS: Scores for donors seropositive for HTLV-I and HTLV-II showed significantly more psychological distress than did scores for seronegative donors (p < 0.0005) or a large national sample (p < 0.05). Both HTLV-I (p = 0.02) and HTLV-II (p = 0.01) seropositivity remained significant predictors of lower overall well-being scores after analysis controlling for race, age, gender, education, income, donation type, time since notification, self-reported health status, and intravenous drug use. Variables that predicted higher overall scores were negative HTLV status, older age, higher income, better health, fewer sick days, and fewer work limitations due to health problems. CONCLUSION: Increased psychological distress may be related to notification of HTLV infection among blood donors in the United States.

Adolescent↗
PubMedDate not supplied

Sensitivity and specificity of human T-lymphotropic virus (HTLV) types I and II polymerase chain reaction and several serologic assays in screening a population with a high prevalence of HTLV-II.

BACKGROUND: Since 1988, all blood donations in the United States have been screened for antibodies to human T-lymphotropic virus type I (HTLV-I). However, the sensitivity of current serologic tests for the detection of HTLV type II (HTLV-II) antibodies and the diagnostic utility of direct tests for HTLV-I and -II using polymerase chain reaction (PCR) are poorly defined. STUDY DESIGN AND METHODS: Five hundred sixty-nine HTLV-I- or -II-seropositive and 687 age- and sex-matched seronegative samples from a high-risk population at an inner-city emergency department were selected. All samples were tested with four HTLV enzyme immunoassays (EIAs), one Western blot assay and one type-specific Western blot assay, one HTLV type-specific EIA, and a research HTLV-I/II PCR kit. RESULTS: Sensitivity of the various EIAs ranged from 95.1 to 99.5 percent, and specificity ranged from 97.2 to 99.4 percent. PCR performed in duplicate without selective retesting had lower sensitivity (85.1 %) and specificity (88.0%). However, PCR detected 20 (3.2%) HTLV-I-positive and 47 (7.5%) HTLV-II-positive samples among the 627 samples that were negative in all EIAs. The type-specific EIA and PCR assay had the highest rate of concordance in classifying samples as either HTLV-I or II, with the type-specific EIA and type-specific Western blot having the next highest rates of concordance. CONCLUSION: In this sample set from a population at high risk for HTLV-II, screening with HTLV-I/II PCR had lower sensitivity and specificity than that with EIAs. However, 4.1 to 10.8 percent of samples were PCR positive but seronegative for HTLV-I or -II, and their true infection status remains undetermined.

Adult↗
PubMedDate not supplied

Human T-cell lymphotropic virus type I and adult T-cell leukemia/lymphoma outside Japan and the Caribbean Basin.

Ninety-six patients with the diagnosis of adult T-cell leukemia/lymphoma (ATLL) were identified in countries outside Japan and the Caribbean Basin. Seventy-four of these patients were initially diagnosed in the United States; 25 of 52 patients whose places of birth were known had been born in the United States. The detection of 14 patients born in the southeastern United States, all black, indicates a group deserving particular attention for studies of human T-cell lymphotropic virus type I (HTLV-I), a suspected etiologic agent in most cases of ATLL. Although geographic clustering of ATLL in areas endemic for HTLV-I, particularly southwest Japan and the Caribbean Basin, is a dramatic feature of this disease, a review of the literature indicates that HTLV-I-associated ATLL probably occurs sporadically in a much wider distribution, the disease being diagnosed in native-born African, Chinese, European, and Latin American patients. A registry for ATLL cases is suggested, to assist in the identification of risk factors for this disease and, at the same time, improve case definitions and early diagnosis.

Adult↗