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Biomedical subjects

A H Coulson

Publications and source records attributed to A H Coulson.

At least 19 recordsLinked to original sources

Interrelationship between diarrhea and vitamin A deficiency: is vitamin A deficiency a risk factor for diarrhea?

A cross-sectional study, a follow-up study and an evaluation of impact of community-based distribution of vitamin A capsules (200,000 IU) were conducted in Omdurman (Sudan) between November, 1988, and March, 1989. In the cross-sectional survey 1441 children less than 5 years of age participated, which established the baseline values for plasma retinol-binding protein. During the follow-up period 290 cases of diarrhea occurred. Low concentrations of plasma retinol-binding protein (less than 1.85 mg/dl) proved to be a risk factor for diarrhea, especially in girls. The relative risk increased after the second year of life. Children who received vitamin A supplementation before commencement of the study had a lower incidence of diarrhea. The protective effect of vitamin A supplementation was greater in girls (relative risk, 0.297; 95% confidence interval, 0.240 to 0.368) than in boys (relative risk, 0.404; 95% confidence interval, 0.352 to 0.464).

Child, Preschool

Pulmonary status of habitual cocaine smokers.

We determined the prevalence of respiratory symptoms and lung dysfunction in a large sample of habitual smokers of freebase cocaine ("crack") alone and in combination with tobacco and/or marijuana. In addition, we compared these findings with those in an age- and race-matched sample of nonusers of crack who did or did not smoke tobacco and/or marijuana. A detailed respiratory and drug use questionnaire and a battery of lung function tests were administered to (1) a convenience sample of 202 habitual smokers of cocaine (cases) who denied intravenous drug abuse and (2) a reference sample of 99 nonusers of cocaine (control subjects). The cocaine smokers (85% black) included the following: 68 never-smokers of marijuana, of whom 43 currently smoked tobacco and 25 did not, and 134 ever-smokers of marijuana (42 current and 92 former), of whom 92 currently smoked tobacco and 42 did not. The control subjects (96% black) included the following: 69 never-smokers of marijuana, of whom 26 currently smoked tobacco and 43 did not, and 30 ever-smokers of marijuana (18 current and 12 former), of whom 21 currently smoked tobacco and 9 did not. Cases smoked an average of 6.5 g cocaine per week for a mean of 53 months. The median time of the most recent use of crack prior to study was 19 days (range less than 1 to 180 days). After controlling for the use of other smoked substances, frequent crack use was associated with: (1) a high prevalence of at least occasional occurrences of acute cardiorespiratory symptoms within 1 to 12 h after smoking cocaine (cough productive of black sputum [43.7%], hemoptysis [5.7%], chest pain [38.5%], usually worse with deep breathing, and cardiac palpitations [52.6%]) and (2) a mild but significant impairment in the diffusing capacity of the lung.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

A nebulizer chronolog to monitor compliance with inhaler use.

The Lung Health Study is a 10-center 5-year clinical trial sponsored by the National Heart, Lung, and Blood Institute to evaluate the effectiveness of early intervention in chronic obstructive pulmonary disease (COPD). The specific objectives of the trial are to determine whether the accelerated decline in lung function characteristic of COPD and morbidity due to COPD can be reduced by special intervention at a relatively early stage in the evolution of the disease. Special intervention consists of a smoking-cessation program and the use of an inhaled bronchodilator to suppress airway hyperreactivity. The use of the inhaler canister is monitored every 4 months by canister weighing and, at two of the 10 centers, by an electronic recording device, the Nebulizer Chronolog. Among trial participants assigned the latter device, results from the first 4 months of the study indicate that only 52% of trial participants who were uninformed as to the nature of the chronolog used their inhaler at least twice daily as measured by the chronolog, compared with 87% as determined by self-report. Satisfactory or good compliance was achieved by 52% of these subjects as measured by the chronolog compared with 85% as assessed by canister weighing. Eighteen percent of uninformed participants "dumped" their inhalers within a 3-hour time period, contributing to the inaccuracy of canister weights as an indicator of compliance. Feedback of information to the participants from the chronolog improved the level of compliance and eliminated the "dumping" phenomenon. We conclude that, when accurate determinations of compliance are important, as in a drug trial, objective medication monitors should be considered. Electronic monitoring of inhaler use can provide valuable feedback, which encourages improved compliance.

Adult

The UCLA population studies of CORD: X. A cohort study of changes in respiratory function associated with chronic exposure to SOx, NOx, and hydrocarbons.

Two never-smoking cohorts in Southern California, one in Lancaster (N = 2340) exposed only to moderate levels of oxidants and the other in Long Beach (N = 1326) exposed to high levels of SOx, NO2, hydrocarbons and particulates completed spirometry and the single-breath nitrogen test five to six years apart. Forty-seven percent and 45 percent of the participants were retested. Mean results at baseline for those tested and not retested were similar. Loss to follow-up was primarily due to moving (39 percent and 47 percent). Every difference of consequence indicated greater deterioration in lung function in Long Beach. The level of significance of the difference was greatest, even in the youngest age groups, for delta N2(750-1250), suggesting that the earliest site of impairment may occur in the small airways. Greater deterioration in spirometric parameters was observed in every age group in Long Beach females above seven years of age at baseline and in Long Beach males above 15 years of age, suggesting that chronic exposure to the pollutant mix occurring in Long Beach ultimately adversely affects the large airways as well as small airways.

Adolescent

No evidence for a role of alcohol or other psychoactive drugs in accelerating immunodeficiency in HIV-1-positive individuals. A report from the Multicenter AIDS Cohort Study.

In a multicenter cohort study of homosexual men, the proportion of seropositives at enrollment who developed the acquired immunodeficiency syndrome (AIDS) during the following 18 months ranged from 5.5% to 8.2% in 1597 alcohol drinkers vs 9.2% in 109 nondrinkers with no clear trend according to use, and from 6.3% to 9.6% for 1662 users vs 7.2% for 83 nonusers of psychoactive drugs prior to enrollment. Among seropositive men with low initial T helper lymphocyte counts, those who continued to use drugs showed no significantly higher 18-month risk of AIDS than nonusers (13% vs 10%); the corresponding risks were 13% and 15%, respectively, for continued heavier vs continued lighter consumption of alcohol. No other manifestations of immunodeficiency were positively associated with substance use prior to enrollment. Prior use was not associated with low mean T helper cell counts at enrollment, and continued drug or alcohol use after enrollment was not associated with greater subsequent decline in counts. As used in a large cohort of homosexual men, psychoactive substances did not enhance the progression of human immunodeficiency virus infection.

Acquired Immunodeficiency Syndrome

Mineral oil lubricants cause rapid deterioration of latex condoms.

As little as sixty seconds' exposure of commercial latex condoms to mineral oil, a common component of hand lotions and other lubricants used during sexual intercourse, caused approximately 90% decrease in the strength of the condoms, as measured by their burst volumes in the standard ISO (International Standards Organization) Air Burst Test. Burst pressures were also reduced, although less dramatically. Lubricants such as Vaseline Intensive Care and Johnson's Baby Oil, each containing mineral oil, also affected condom integrity. Five min. exposure of condoms to glycerol, a frequent component of hand lotions and 'personal lubricants', did not significantly affect burst volume or pressure. Aqueous nonoxynol-9 spermicide did not affect either burst index. The implications of these results for contraception and protection from sexually transmitted diseases, including AIDS, are discussed.

Contraceptive Devices, Male

Bone mineral content in postmenopausal women: comparison of omnivores and vegetarians.

This cross-sectional study of bone mineral content (BMC)/bone width (BW) (BMC/BW, cortical radius) was conducted in elderly, free-living Methodist omnivores (n = 146) and Seventh-day Adventist vegetarians (n = 144) in southern California. The purpose was to investigate relationships between BMC/BW and dietary factors (primarily vegetarianism and intakes of protein and calcium) and use of prescribed drugs. BMC was measured by single-photon absorptiometry. Dietary intakes during current and early periods of life were assessed by 24-h dietary recall and frequency methods. Information about drug use was obtained by interview. BMC/BW was not different in omnivores vs vegetarians. There were no significant relationships or trends between current or early dietary intakes and BMC/BW in either group. In multiple-regression analysis, age, weight, and use of estrogen and thiazide diuretics were predictive of 31% of the variability in BMC/BW in the total group.

Anthropometry

Respiratory symptoms and lung function in habitual heavy smokers of marijuana alone, smokers of marijuana and tobacco, smokers of tobacco alone, and nonsmokers.

To evaluate the possible pulmonary effects of habitual marijuana smoking with and without tobacco, we administered a detailed respiratory and drug use questionnaire and/or lung function tests to young, habitual, heavy smokers of marijuana alone (n = 144) or with tobacco (n = 135) and control subjects of similar age who smoked tobacco alone (n = 70) or were nonsmokers (n = 97). Mean amounts of marijuana and/or tobacco smoked were 49 to 57 joint-years marijuana (average daily number of joints times number of years smoked) and 16 to 22 pack-years of tobacco. Among the smokers of marijuana and/or tobacco, prevalence of chronic cough (18 to 24%), sputum production (20 to 26%), wheeze (25 to 37%) and greater than 1 prolonged acute bronchitic episode during the previous 3 yr (10 to 14%) was significantly higher than in the nonsmokers (p less than 0.05, chi square). No difference in prevalence of chronic cough, sputum production, or wheeze was noted between the marijuana and tobacco smokers, nor were there additive effects of marijuana and tobacco on symptom prevalence. We noted significant worsening effects of marijuana but not to tobacco on specific airway conductance and airway resistance (tests of mainly large airways function) in men and of tobacco but not of marijuana on carbon monoxide diffusing capacity and on closing volume, closing capacity, and the slope of Phase III of the single-breath nitrogen washout curve (tests reflecting mainly small airways function) (p less than 0.03, two-way ANCOVA). No adverse interactive effects of marijuana and tobacco on lung function were found.

Adult

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

Respiratory effects of cocaine "freebasing" among habitual users of marijuana with or without tobacco.

Use of cocaine by smoking its alkaline precursor ("freebasing") has become increasingly prevalent. Recent studies of small numbers of cocaine users suggest that freebasing frequently causes cough, dyspnea, and abnormalities in diffusing capacity (DCO), although these findings could have been due to concomitant use of other drugs. We therefore evaluated the relationship between cocaine use by freebasing and chronic respiratory symptoms and lung dysfunction in a large sample of habitual smokers of marijuana with or without tobacco who denied intravenous drug abuse. The findings suggested that, among habitual marijuana smokers, "moderate" cocaine smoking damaged both large and small airways, as reflected by functional changes that were independent of concomitant marijuana use and appeared to be synergistic with the effects of tobacco. On the other hand, no adverse influence of cocaine smoking on the pulmonary microcirculation was demonstrated in our sample of freebase users.

Adult

A controlled trial of real and simulated acupuncture in the management of chronic asthma.

In 25 patients with moderate to severe asthma, we compared the therapeutic effectiveness of classic Chinese acupuncture with that of "placebo" acupuncture administered in a randomly ordered, subject- and evaluator-blind, crossover fashion twice weekly for 4 weeks. Real and placebo acupuncture periods were each preceded and followed by 3- to 4-week periods during which no acupuncture was administered. Outcome variables consisted of the following: daily symptoms and medication use self-scored on patient diaries, spirometry and whole body plethysmography performed once weekly during the entire course of the study and repeated serially during 3 hours after real and placebo acupuncture treatment, patients' self-assessment of acute efficacy of acupuncture therapy, and physician's physical findings before and after acupuncture treatment. Two-way analysis of variance failed to reveal a significant effect of either form of acupuncture on symptoms, medication use, or lung function measurements. Similarly, no significant acute effect of acupuncture on lung function, self-ratings of efficacy, or physician's physical findings was found by covariance analysis or the Wilcoxon signed-rank test. When data during the entire course of the study were examined on an individual basis by analysis of variance with repeated measures, only two subjects demonstrated significantly favorable responses to real versus placebo acupuncture, but one subject demonstrated the reverse, suggesting that these responses were not specifically related to acupuncture therapy. Thus, our findings failed to demonstrate any short- or long-term benefit of acupuncture therapy in the management of moderate to severe asthma.

Acupuncture Therapy

Zinc supplementation during pregnancy in low-income teenagers of Mexican descent: effects on selected blood constituents and on progress and outcome of pregnancy.

As a follow-up of our study of pregnant women, we report effects of zinc supplementation during pregnancy in another population of 138 Hispanic teenagers in Los Angeles. Teenagers were randomized (double-blind) to a control or zinc-supplemented group and received similar daily vitamin and mineral supplements except for 20 mg zinc added to the zinc-supplemented group's capsules. Initially, mean dietary zinc intakes of both groups were about 50% of the Recommended Dietary Allowance and their mean serum zinc levels did not differ significantly (69.8 +/- 11.2 micrograms/dl in control and 69.0 +/- 11.4 micrograms/dl in zinc-supplemented group). Zinc supplementation did not maintain mean serum zinc levels during pregnancy but, as in our earlier study, it reduced (p = 0.018) the number of low serum zinc values (less than or equal to 53 micrograms/dl) in late pregnancy. Zinc supplementation did not affect outcome of pregnancy but serum zinc levels were lower (p = 0.038) in teenagers with pregnancy-induced hypertension than in normotensives.

Adolescent

The UCLA population studies of chronic obstructive respiratory disease. I. Methodology and comparison of lung function in areas of high and low pollution.

The prevalence of symptoms of chronic obstructive respiratory disease and of functional respiratory impairment was determined in 3465 residents (70 per cent of enumerated) of an area historically exposed to photochemical/oxidant pollutants and 4509 residents (79 per cent of enumerated) of an area exposed to low levels of chemical pollutants. Tests administered included the NHLI questionnaire, electronic volume spirometry, whole body plethysmography, and the single-breath nitrogen test (deltaN2750-1250 and closing volume). Cough and cough with sputum were more frequently reported in the low-pollution area. Lung function was better among residents of the low-pollution area according to FEV1, FVC, maximal expiratory flow rates, closing volume fraction, thoracic gas volume, and airway resistance. Maximal mid-expiratory flow rate, considered to be a sensitive spirometric test for detection of small airways disease, was similar in residents of both areas. Mean deltaN2750-1250 was slightly worse among residents of the low-pollution area. Findings suggest that adverse effects of long-term exposure to photochemical/oxidant pollutants may occur primarily in the larger airways both among smokers and never smokers. The greatest differences between areas were observed in residents 18-59 years of age, suggesting that long-term exposure may be required to cause measurable impairment and that these differnces may be obliterated by such factors as smoking, differential out-migration and differential survival.

Adolescent

HLA types and immunity in multiple sclerosis.

HLA types and levels of humoral and cell-mediated immune responses to several antigens were studied in a large group of patients with multiple sclerosis, and in controls. Patients were more likely than controls to have the DRw2 antigen. They had higher mean antibody titers to measles but not to cytomegalovirus, herpes 1, or herpes 2, and had less competent cell-mediated responses. Antibody titers to measles were lower and cell-mediated immune responses were more effective in patients with the DRw2 antigen in patients than in patients without it. This apparent specificity for measles suggests that the etiology of multiple sclerosis is related to the immune response to measles or related viruses.

Antibodies, Viral

Comparison of placebo, nitroglycerin, and isosorbide dinitrate for effectiveness of relief of angina and duration of action.

Each of 13 patients with angina had either chewable isosorbide dinitrate, nitroglycerin (sublingual therapy), or placebo administered on each of three different days when mild anginal pain had been induced by walking on a treadmill. Both therapy with isosorbide dinitrate and therapy with nitroglycerin were effective in bringing about complete relief of the angina in less than ten minutes of uninterrupted continuous walking on the treadmill in 11 of the 13 subjects, while administration of placebo afforded complete relief in none. The duration of action of the drug was determined by following the first effort (during which the tested drug was given) by successive ten-minute walks at the same workload that first induced anginal pain. Half-hour resting periods separated the repeated periods of exercise, and the duration of action was taken to be the time from administration of the agent to the return of angina on one of the repetitive efforts. No prolonged protection was afforded by administration of the placebo. Nitroglycerin protected for slightly longer than one hour, while isosorbide dinitrate protected for 2 1/2 to 3 hours.

Aged