Biomedical subjects
Publications and source records attributed to R Royce.
The importance of radiology departments is growing in all acute hospitals. A review of skill-mix could reduce pressure on radiology departments. The role of radiographers trained in sonography should be extended.
In an effort to understand issues affecting prenatal care access and utilization from the perspectives of human immunodeficiency virus (HIV)-infected women who receive inadequate prenatal care, we conducted three in-depth qualitative and quantitative interviews. From a thematic analysis of the narrative interviews, four broad areas emerged as pertinent to these women's prenatal care experiences. These were issues related to pregnancy, HIV, psychosocial conditions, and the health care system. For these women, the barriers to prenatal care utilization included the unexpected and unplanned nature of the pregnancy and mental health issues related to HIV infection. Poverty, periodic homelessness, addiction to illicit substances, and lack of social support were also important barriers. Furthermore, perceptions of the health care system as threatening, including fears related to consequences of disclosing illicit activities, discrimination, and breach of confidentiality emerged as salient barriers. Facilitating factors included the pregnancy being experienced as a life-transforming event, concern for their children, especially preventing HIV-1 vertical transmission, availability of treatment, and support from health care professionals. Prominent throughout the interviews were the women's mental health concerns and need for professional support.
The culture of primary HIV isolates requires fresh phytohemagglutinin (PHA) stimulated peripheral blood mononuclear cells (PBMC) from seronegative donors. The variation inherent in donor cells, obtained from many different individuals, might affect the likelihood of virus isolation. We developed a quality control (QC) procedure which could determine quantitatively the susceptibility of random donor cells to HIV infection. The QC reagents consisted of cells and supernatants infected with a syncytium-inducing clinical isolate of HIV. Six 5-fold dilutions of QC cells (starting at 1000 cells) and supernatant (starting at a 1:200 dilution) were cultured in parallel with 1 x 10(6) 2-3-day-old PHA stimulated donor cells. After 7 or 14 days the resulting culture supernatant was tested for syncytia formation with MT-2 cells. A total of 127 sequential donors were tested over an 11 month period. All but one donor PBMC preparation was capable of being infected by the QC reagents (and this particular donor was permissive for several other primary isolates). The standard variation observed among all cultures was about one 5-fold dilution. The coefficient of variation ranged from 10.7 to 17.3%. These results suggest that the mononuclear cells from most, if not all, individuals are permissive for HIV to approximately the same level. Other quality control measures used in the laboratory are described.
The seroprevalences of hepatitis B virus (HBV) and hepatitis C virus (HCV) markers were evaluated in a random sample of 803 children attending school in Ashanti-Akim North district in Ghana in order to gain a better understanding of transmission patterns of these viruses, particularly horizontal transmission of HBV. This rural district is typical of 70% of the Ghanaian population. The overall seroprevalence of at least one marker of HBV infection was 61.2%, with rates increasing from 48% to 80% between the ages of 6-18 years (P < 0.001). The overall HBsAg seroprevalence was 15.8%, with the proportion of HBsAg positives amongst those with anti-HBc increasing from 39.3% in 6-7-year-olds to 51.8% in 12-13-year-olds. It appears that horizontal transmission during this age period was accompanied by a high rate of HBsAg carriage. Among those infected but not carriers, i.e., those HBsAg negative and anti-HBc positive, > 50% lacked detectable levels of anti-HBs, an unusual pattern of convalescent immune response to HBV. The overall seroprevalence of anti-HCV was 5.4% and did not differ significantly by age or gender. Anti-HCV seroprevalence was not associated with the presence of any HBV marker. A better understanding of the unusually high prevalences of HBV and HCV infections demonstrated in this population is likely to influence vaccination and blood transfusion policies and to stimulate further evaluations of these infections and their vehicles of spread in highly endemic regions such as sub-Saharan Africa.
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The relationship between CD8+ lymphocyte counts and progression to AIDS was studied in 340 HIV-1-seropositive men participating in a population-based prospective study. Overall, the relative hazard for developing AIDS during 60 months of observation was slightly elevated (1.08, P = 0.003), indicating an 8% increase in risk of progression for every 100 CD8+ cell count increment. When the data were analyzed in relation to date of diagnosis, the relative hazard was depressed (0.90, P less than 0.001) for the period 6 months prior to diagnosis, but was close to 1.0 for the period 6-36 months prior to diagnosis. These findings suggest a complex relationship between CD8+ cell counts and progression to AIDS, with the possibility that various subsets of the CD8+ compartment play different roles.
Serum beta 2-microglobulin (beta 2M) levels were measured by radioimmunoassay in 962 unmarried men recruited by probability sampling from areas in San Francisco, Calif, most severely affected by the epidemic of acquired immunodeficiency syndrome (AIDS). From July 1984 to December 1987, 65 incident AIDS cases occurred in 388 homosexual/bisexual men infected by the human immunodeficiency virus (HIV) at the time of recruitment. The mean level of beta 2M in uninfected individuals at entry was 170 nmol/L. In HIV-seropositive patients who had not developed AIDS, the mean beta 2M level was 254 nmol/L, and in those who had developed AIDS, the beta 2M level was 347 nmol/L. After 36 months of follow-up, 34% of individuals with beta 2M levels greater than 322 nmol/L at entry developed AIDS, 21% of individuals with levels between 246 and 322 nmol/L developed AIDS, while only 7.3% of those with levels below 246 nmol/L developed AIDS. The beta 2M level predicted the development of AIDS independently of the CD4 lymphocyte count in HIV-seropositive individuals. Thus, 65.5% of HIV-seropositive individuals with beta 2M levels above 322 nmol/L and CD4 lymphocyte counts of below 500/microL developed AIDS in 3 years. This represents an 18.4-fold increased relative hazard at 3 years over individuals with beta 2M and CD4 cell counts within the reference range for uninfected individuals. A nomogram is provided that allows the easy calculation of the probability of an HIV-infected person developing AIDS in 36 months depending on prevalent levels of CD4 lymphocytes and serum beta 2M.
CD4 and CD8 T lymphocytes of three groups of men infected by the human immunodeficiency virus (HIV) were examined twice yearly for 36 months to elucidate the temporal trends in T lymphocytes during infection. The three groups were 37 HIV seroconverters, 304 prevalent HIV seropositives remaining free of the acquired immunodeficiency syndrome (AIDS), and 69 men who developed AIDS during observation. Six months before seroconversion, CD4 levels were similar among HIV seroconverters and 356 seronegative controls. Within 18 months of seroconversion, mean CD4 levels fell to the level of the prevalent seropositives at study entry. From there, the rate of decline slowed. CD8 lymphocyte counts rose dramatically at seroconversion. Among AIDS-free prevalent seropositives, CD4 levels fell steadily over 36 months of observation. By contrast, CD8 cell levels rose slowly. Among men who developed AIDS, mean CD4 levels fell more rapidly again during the 18 months prior to diagnosis. CD8 cell levels remained elevated until 6-12 months before diagnosis, when they began to fall.
Forty-nine percent of homosexual/bisexual men were positive for antibody to the human immunodeficiency virus (HIV) in a population-based probability sample of 1034 single men recruited from San Francisco. All heterosexual men were negative. Among seropositive men, marked lymphadenopathy was present in 29%, and 16% had at least two other symptoms or signs suggestive of HIV infection. However, lymphadenopathy alone failed to indicate severity of immune impairment. The occurrence of two or more clinical signs and symptoms, except for marked lymphadenopathy, correlated with HIV infection, diminished skin test reactivity, and reduction in Leu 3a T cells. Twenty-nine percent of seropositive men had fewer than 400 absolute Leu 3a T helper cells per microliter (less than 0.4 X 10(9)/L). Seronegative homosexual/bisexual men did not differ from heterosexual men in any clinical or laboratory variables except for increased numbers of suppressor Leu 2a T suppressor cells per microliter.
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Phospholipid metabolities and phospholipids containing arachidonic acid (AA) inhibited the antidiuretic hormone (ADH)-induced increase in transepithelial water flow in the toad urinary bladder, but had no effect on basal water flow when added to the serosal bathing solution. Other fatty acid-substituted phospholipid metabolites had no effect on osmotic water movement in the presence or absence of ADH. Indomethacin attenuated the inhibitory effects of the AA containing phospholipid metabolities (PMAA), suggesting that the PMAA response required AA release and prostaglandin (PG) formation. PMAA increased PGE formation as measured by radioimmunoassay. PG have been reported to inhibit ADH-stimulated water flow by inhibiting adenylcyclase. PGE2 (10(-8) M) had no effect on cyclic AMP-stimulated water flow, whereas exogenous AA and PMAA attenuated the hydroosmotic response to added cyclic AMP. Indomethacin only partially reversed the inhibition by AA of the cyclic AMP-associated water movement, suggesting that the inhibition by AA and PMAA may involve other metabolites of AA than PG. PG and the AA cascade have been implicated as cellular modulators of the ADH hydroosmotic response. The present results offer additional support to the theory that this system may regulate the intracellular events that are transduced following receptor activation by ADH.
Phenothiazines and W7, calmodulin antagonists, inhibit the water flow response produced by ADH, exogenous cyclic AMP, phosphodiesterase inhibition and serosal hypertonicity. Calmodulin antagonists had no effect on osmotic water movement in the absence of hormone. Calmodulin was isolated and localized by immunofluorescence in bladder epithelial cells. Phenothiazines inhibited toad bladder calmodulin activation of phosphodiesterase and prevented fluorescent antibody recognition. The results suggest that the calcium-calmodulin process plays a role in the hydro-osmotic response to ADH and that produced by serosal hypertonicity. The calmodulin common site occurs subsequent to cyclic AMP formation, perhaps on the microtubule-microfilament system.
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Lung cancer deaths occurring between 1935 and 1969 among women residing near an arsenic emitting smelter were examined. For three geographically defined exposure groups, the observed and expected number of lung cancer deaths were compared. In none of the exposure groups did the observed number of deaths exceed the expected. However, an index of exposure based on distance of residence from the smelter and duration of residence in the area was 27% higher for cases than for age-matched controls (p = .10). Adjusting for a latency of 20 yr, case exposures were 23% higher than for controls (p = .07). Dividing individuals into quintiles of exposure yielded odds ratios ranging from 1 to 1.6 (test of trend, p = .07).
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