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Biomedical subjects

R Detels

Publications and source records attributed to R Detels.

At least 163 records · Page 9Linked to original sources
PubMed1987

Predictors of clinical AIDS in young homosexual men in a high-risk area.

One hundred and sixty-seven homosexual men in Los Angeles characterized by HIV antibody, T-cell numbers, titres to cytomegalovirus (CMV), and specific sexual practices were followed for two years for immune changes and for more than three years for development of clinical AIDS. Thirty-five per cent had antibody to HIV at baseline. The mean level of T-helper (Th) cells was significantly lower and of T-suppressor (Ts) cells significantly higher in HIV seropositives than in seronegatives. The annualized incidence of HIV seroconversion was 7%. Eight men developed AIDS, an attack rate of 14% in those with HIV antibody at baseline. A number of observations were made: T-cell alterations, except a transient elevation in Ts cells, were unusual in the absence of HIV antibody; a seropositive man with a T-cell alteration was significantly less likely to revert to 'within normal limits' than was a seronegative man; a steady decline in the number of Th cells preceded onset of clinical AIDS; the number of Ts cells remained higher in men subsequently developing AIDS than in other seropositive men; clinical AIDS occurred only in men with HIV antibody whose CMV antibody levels were above the median for the group (1:1600); and the attack rate for clinical AIDS was 50% in men with HIV antibody and elevated CMV who at baseline had either: fewer than 325 Th cells/cc, or whose Th/Ts ratio was below 0.8 (but whose levels of Th and Ts cells were within normal limits).(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1987

Factors associated with prevalent human immunodeficiency virus (HIV) infection in the Multicenter AIDS Cohort Study.

Interviews regarding medical history, life-style, specific drug taking and sexual activities, and physical examinations were administered to 4,955 homosexual men who volunteered for the Multicenter AIDS Cohort Study in Baltimore, Chicago, Los Angeles, and Pittsburgh. Overall, the prevalence of antibodies to human immunodeficiency virus (HIV) in these men was 38.0%. The factor most strongly associated with prevalent HIV infection according to a multiple logistic regression model was rectal trauma, a composite variable which included receptive anal fisting, enemas before sex, reporting of blood around the rectum, and the observation of scarring, fissures or fistulas on rectal examination. Receptive anal intercourse also was strongly associated with HIV infection in the model. The multivariate relative odds for HIV antibody positivity was 7.72 for the highest level of rectal trauma and 3.04 for receptive anal intercourse. Symptoms reported to occur in some persons who subsequently develop acquired immunodeficiency syndrome (AIDS) were frequent among HIV seropositive men (12.9%) but were reported in 8.4% of seronegative men as well. Generalized lymphadenopathy was observed significantly more often in seropositive men (48.8%) compared with seronegative men (11.4%). The prevalence of HIV antibodies was inversely related to the number of T-helper cells and directly related (to a lesser extent) to the number of T-suppressor cells. The results suggest that disruption of the rectal mucosa provides access by HIV to the blood stream and to specific immunologic cells. Since symptoms and generalized lymphadenopathy were often reported among seronegative men, they probably also occur among some seropositive men not currently progressing to AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Antibody that inhibits human immunodeficiency virus reverse transcriptase and association with inability to isolate virus.

Most individuals infected with human immunodeficiency virus (HIV), the causative agent of acquired immune deficiency syndrome, produce an antibody against the viral reverse transcriptase (RT). Our studies show that 67% of HIV-seropositive individuals (33 of 49) produced an antibody that specifically inhibited viral RT enzyme activity. We were able to isolate HIV from only 18% of these individuals (6 of 33). On the other hand, virus was readily isolated from 63% of HIV-seropositive individuals (10 of 16) who did not demonstrate this antibody. Further examination of this RT-inhibiting antibody and its role during virus infection is needed, as it may prove to be of diagnostic, prognostic, or therapeutic value in this study and treatment of acquired immune deficiency syndrome.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Significance of quantitative enzyme-linked immunosorbent assay (ELISA) results in evaluation of three ELISAs and Western blot tests for detection of antibodies to human immunodeficiency virus in a high-risk population.

The characteristics of primary (first) tests with three enzyme-linked immunosorbent assay (ELISA) kits for human immunodeficiency virus (HIV) antibody were determined. The three ELISAs were performed on 3,229, 3,130, and 685 specimens from high-risk individuals using the Litton (LT; Litton Bionetics Laboratory Products, Charleston, S.C.), Dupont (DP; E. I. du Pont de Nemours & Co., Inc., Wilmington, Del.), and Genetic Systems (GS; Genetic Systems, Seattle, Wash.) kits, respectively. Evaluation was based on the distribution of quantitative test results (such as optical densities), a comparison with Western blot (WB) results, reproducibility of the tests, and identification of seroconverters. The performances of the GS and the DP kits were good by all four criteria and exceeded that of the LT kit. Primary ELISA-negative results were not always confirmed with repeat ELISA and by WB testing. The largest percentage of these unconfirmed negative test results came from samples with quantitative results in the fifth percentile nearest the cutoff. Thus, supplementary testing was indicated for samples with test results in this borderline negative range. Similarly, borderline positive primary ELISA results that were quantitatively nearest (fifth percentile) the cutoff value were more likely to be antibody negative on supplementary testing than samples with high antibody values. In this study, results of repeated tests by GS ELISA showed the least change from first test results. DP ELISA showed more unconfirmed primary positive test results, and LT ELISA showed more unconfirmed primary negative test results. Designation of a specimen with a single ELISA quantitative level near the cutoff value as positive or negative should be viewed with skepticism. A higher than normal proportion of specimens with high negative optical densities by GS ELISA (fifth percentile nearest the cutoff) and also negative by WB were found to be from individuals in the process of seroconversion.

Antibodies, Viral↗
PubMed1987

The UCLA population studies of chronic obstructive respiratory disease. 9. Lung function changes associated with chronic exposure to photochemical oxidants; a cohort study among never-smokers.

Two cohorts of never-smoking residents of Los Angeles were studied on two occasions five years apart. One cohort (N = 1,099) lived in a community with moderate levels of photochemical pollution and low levels of other pollutants, and the second (N = 1,117) lived in a community with very high levels of photochemical oxidant and relatively high levels of sulfates and particulates. Studies included measurement of forced expiratory volumes and flow rates and single-breath nitrogen washout, as well as use of a standardized questionnaire. The data represent 47 percent of 2,340 and 58 percent of 1,935 residents, respectively, of the original community samples. Mean baseline spirometry and nitrogen washout for those who were and those who were not retested were similar, reflecting the fact that loss to follow-up was primarily due to changes of residence. In the more polluted area there were significantly worse lung function test results for both men and women at baseline and significantly more rapid deterioration at follow-up. Mean changes in nitrogen washout were significantly greater in the more polluted community for both sexes and for all age groups including children. Most of the spirometric test results showed significantly more rapid decline among adults in the more polluted community. These results are consistent with the hypothesis that chronic exposures to a mix of photochemical oxidants, sulfates and particulates are associated with increased loss of lung function, which is especially marked among tests that reflect function of the small airways.

Adolescent↗
PubMed1984

The relation of cytomegalovirus and Epstein-Barr virus antibodies to T-cell subsets in homosexually active men.

Eighty-nine homosexual men participated in a study of sexual practices, T-cell subsets, and antibody titers to cytomegalovirus (CMV) and Epstein-Barr virus (EBV). The prevalence of antibody to CMV was 96% and to EBV, 94%. Titers to CMV were higher in those practicing receptive anal intercourse. The CMV antibody titers were positively correlated with the T-helper/suppressor ratio, number of partners and venereal disease episodes, number of T-suppressor cells, and EBV titers. Twelve percent of the participants had a low ratio only, 18% T-suppressor augmentation, and 3% T-helper deficiency. The CMV titer and prevalence of receptive anal intercourse were higher in those with a low ratio only, T-suppressor augmentation, and T-helper deficiency. These results suggest that CMV infection is acquired through receptive anal intercourse and is associated with an increase in T-suppressor cells and, in some persons, a decrease in T-helper cells.

Adult↗
PubMed1984

Quantitative changes in T helper or T suppressor/cytotoxic lymphocyte subsets that distinguish acquired immune deficiency syndrome from other immune subset disorders.

Quantitative measurements of the immune cell subgroups, T helper (Leu 3+/OKT4+) cells and T suppressor/cytotoxic (Leu 2+/OKT8+) cells, were made in patients having acquired immune deficiency syndrome (AIDS) with Kaposi's sarcoma and in patients with AIDS and opportunistic infection, as well as in three other relevant populations. These included patients with lymphadenopathy syndrome, e.g., homosexually active males with lymphadenopathy who sought medical care for additional symptoms, and healthy male homosexuals, as well as a control population. Decrease in the number of T helper cells is characteristic of AIDS with Kaposi's sarcoma or opportunistic infection. Augmentation of the T suppressor/cytotoxic cell population is rare in AIDS with Kaposi's sarcoma but is more frequent in AIDS with opportunistic infection. Augmentation of the T suppressor/cytotoxic cell population, however, may occur in a variety of circumstances, including cytomegalovirus and other viral infections, in healthy, homosexually active males, and in otherwise healthy hemophiliac subjects receiving factor VIII treatment. Reduced T helper:T suppressor/cytotoxic cell ratio can be caused by either decrease in the number of T helper cells or augmentation of the T suppressor/cytotoxic cell population. Lowered T helper:T suppressor/cytotoxic cell ratio does not, by itself, help to distinguish between AIDS and other causes of reduced ratios. Quantitative measurements are needed to define the T subset changes. AIDS is characterized by decrease in the number of T helper cells and reduced T helper:T suppressor/cytotoxic cell ratio. The T helper (Leu 3+) and T suppressor/cytotoxic (Leu 2+) cell subpopulations can change independently. Identification of decrease in the number of T helper cells as an alteration that occurs independently of numerical change in other lymphoid subpopulations, such as T suppressor/cytotoxic cells and B cells, and the close association of the decrease in the number of T helper cells with AIDS are consistent with a distinct pathogenesis (and cause) for AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Application of simulation techniques for estimating duration of multiple sclerosis derived from prevalence-formed cohorts.

Comparisons of the average duration of multiple sclerosis derived from a prevalence survey of cases alive in 1970 in a low-risk area (Los Angeles County, California) and a high-risk area (King and Pierce Counties, Washington) suggest that patients in the high-risk area had a longer duration of disease than patients in the low-risk area. Because this finding was unexpected and because the underlying population of these two areas has been increasing at different rates, two simulation models were developed to estimate the duration of multiple sclerosis from a prevalence survey, taking into account the effects of changes in the population over time. Comparison of the durations derived from the two simulation studies suggested that underestimation of true backward recurrence time from the simulation studies was similar for the two study areas. Thus, the observed differences in duration between the two areas probably reflect the course of disease rather than differences in rate of growth of the two populations. These studies demonstrate the usefulness of simulation studies in estimating disease duration from cohorts derived from prevalence surveys of non-stable populations.

Adult↗
PubMed1984

Onset symptoms as predictors of mortality and disability in multiple sclerosis.

941 cases of definite/probable multiple sclerosis living in Los Angeles County, California and King and Pierce Counties, Washington in 1970 who had onset between 1960 and 1969 were followed for mortality and disability through 1980. Early age of onset and residence in Washington State were predictors of less rapid and severe subsequent course. Coordination symptoms at onset were prognostic of rapid progression to disability and/or early death, whereas early motor weakness was significantly predictive only for disability. The presence of sensory symptoms in addition to motor and/or coordination symptoms at onset, however, indicated a better prognosis than coordination and/or motor symptoms alone. This observation and the results of regression analyses indicated that specific groupings of symptoms at onset were more important for predicting course than the number of symptoms present at onset.

Adult↗
PubMed1984

The UCLA population studies of chronic obstructive respiratory disease. VII. Relationship between parental smoking and children's lung function.

Results of previous studies of the impact of parents' smoking on children's lung function have been conflicting. To evaluate further the effect of passive smoking on the lung function of children, we analyzed respiratory questionnaire and lung function results obtained during field testing of residents (aggregated according to household) of 4 census tracts in the Los Angeles area. We report here on 971 white, non-Hispanic, nonsmoking, nonasthmatic children residing in households in which the smoking status of both parents was known; households with ex-smoking parents were excluded from analysis. We divided these children into 3 categories related to parental smoking status: (1) at least mother smokes , (2) only father smokes , and (3) neither parent smokes . Prediction equations for several indexes of forced expired volume and flow were derived separately for boys and girls 7 to 17 yr of age. Analysis of variance was used to compare lung function residuals of children in the 3 different passive smoking categories. Analysis was performed separately on younger (7 to 11 yr of age) and older (12 to 17 yr of age) children of each sex. Among younger male children, residual values were significantly lower in the maternal smoking category than in the other 2 household categories for maximal flow and maximal flow after exhalation of 25% of forced vital capacity (FVC) (p less than or equal to 0.05); no differences were noted between the paternal-smoking only and nonsmoking household categories. A trend toward similar results was found in older male children, which approached significance (p less than 0.1). Among females, forced expiratory flow during the middle half of the FVC and maximal flow after exhalation of 75% of FVC were significantly lower in relation to maternal smoking in the older children only (p less than or equal to 0.05). ANOVA revealed no decrement in lung function in relation to passive smoking among children with asthma or bronchitis (n=138).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

The UCLA population studies of chronic obstructive respiratory disease. VIII. Effects of smoking cessation on lung function: a prospective study of a free-living population.

We evaluated effects of smoking cessation on lung function and respiratory symptoms of residents 25 to 64 yr of age from 3 communities in the Los Angeles area who completed a detailed respiratory questionnaire and measurements of forced expired volumes and flow rates, closing volume, and closing capacity at 2 times (T1 and T2) 5 yr apart. Results were analyzed in 2,401 participants who fit into 4 smoking categories: never smokers (414 males, 737 females); former smokers (294 males; 172 females); quitters between T1 and T2 (106 males, 62 females); and continuing smokers (278 males, 338 females). Covariance analysis was used to determine differences in lung function across smoking categories at T1 and T2 (adjusted for T1 values) and differences in decline in lung function between T1 and T2. Chi-square analysis was used to compare continuing smokers and quitters with respect to changes in respiratory symptoms. In this population, smoking at T1 was associated with impairment in all indexes of lung function evaluated. Smoking cessation led to significant improvement in symptoms of cough, wheeze, and phlegm production, and to significantly less decline in indexes of small airway function during 5 yr compared with measurements in continuing smokers. However, at T2, lung function still was lower among quitters compared with former and never smokers. Forced expiratory volume in one second (FEV1) was marginally improved in women who quit compared with those who continued to smoke.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Multiple sclerosis and age at exposure to childhood diseases and animals: cases and their friends.

Eighty-eight multiple sclerosis case-friend pairs were interviewed by telephone to elicit information about early-life exposures. Available mothers were also interviewed. Risk factors included childhood diseases, exposures to animals, and residence. We found a positive association between MS and having measles at a later than usual age. Analysis of the data in the literature showed that this was the third statistically significant association between MS and later age for measles. This is consistent with the hypothesis that the pathogenesis of MS includes an age-dependent host response to measles.

Adult↗
PubMed1984

The UCLA population studies of chronic obstructive respiratory disease. VI. Relationship of physiologic factors to rate of change in forced expiratory volume in one second and forced vital capacity.

The mean annualized changes in height (delta height), in forced expiratory volume in one second (delta FEV1), and in forced vital capacity (delta FVC), measured at a 5-yr interval, were determined by year of age for 1,458 residents 7 to 59 yr of age in 2 communities in Los Angeles. The rate of change in delta height, delta FEV1, and delta FVC increased each year until early puberty and then decreased thereafter. The age at which the delta FEV1 and delta FVC reversed from an increasing to a decreasing rate was older in males (13 yr) than in females (11 yr) and lagged about 1 yr behind the age at which rate of delta height reversed. The rate of delta FEV1 and delta FVC sharply declined thereafter until the early 20s, at which age the rate of change leveled off to a constant value. The age at which the delta FEV1 and delta FVC reversed from positive to negative ranged from 21 to 23+ yr, but was probably of less importance physiologically than the age at which the rate of change in delta FEV1 and delta FVC leveled off. The results suggest that growth factors are the major determinants for changes in delta FEV1 and delta FVC until the late teens. From the until the mid-20s, both growth factors and physiologic deterioration may affect delta FEV1 and delta FVC. Thereafter, the primary determinant of delta FEV1 and delta FVC appears to be a gradual but steady decline in physiologic status.

Adolescent↗
PubMed1983

Relation between sexual practices and T-cell subsets in homosexually active men.

27% of 89 young, non-ill, homosexually active men in Los Angeles had a Leu-3(OKT4)/Leu-2(OKT8) ratio less than or equal to 0 . 8. The low ratio was due to a significantly raised mean number of Leu-2 cells, whereas individuals with acquired immune deficiency syndrome had a decrease in both Leu-3 and Leu-2 cells. The term "acquired immune augmentation" may be appropriate for those with a low ratio due to raised numbers of Leu-2 cells. Those practising passive (receptive) anal intercourse had a significantly higher mean number of Leu-2 cells than did those practising only active (insertive) anal intercourse or no anal intercourse. The results of this study suggest that two distinct conditions occur in homosexually active men. Whether acquired immune augmentation is a precursor of the rarer acquired immune deficiency syndrome or is an unrelated disorder needs to be determined. In this study passive anal intercourse was associated with acquired immune augmentation.

Acquired Immunodeficiency Syndrome↗