Incidence of latex sensitization among latex glove users

BACKGROUND

Although there are several reports of the prevalence of latex sensitization among health care workers, the incidence of sensitization is unknown.

OBJECTIVE

The objective of this study was to estimate the incidence of sensitization among latex glove users at a hospital in Hamilton, Ontario, Canada.

METHODS

Workers with negative results to the skin test at baseline were followed prospectively over 1 year, some wearing powdered gloves and others using powder-free gloves. They were reevaluated in 1995 with a questionnaire and skin prick test (SPT) sensitivity to latex reagents, three common inhalants, and six foods. A conversion was defined as a (new) latex SPT with wheal diameter at least 4 mm greater than saline control. Glove extracts were assayed for antigenic protein, and air samples were obtained to estimate exposure to airborne latex protein.

RESULTS

During powdered glove use, personal exposures ranged from 5 to 616 ng/m3, whereas during powder-free glove use, all but two results for air samples were below the limit of detection (about 0.1 ng/m3). During the study period, the protein concentration in the powdered gloves, initially mean 557 microg/gm of sample, declined at a rate of 295 microg/gm per year (p < 0.0001). Of the 1075 SPT-negative participants at baseline, 479 were working in eligible wards, and of these, 435 (91%) participated in follow-up, 227 using powder-free gloves and 208 using powdered gloves. We identified four conversions, two (1.0%) in the powdered glove group and two (0.9%) in the powder-free group. The two participants using powdered gloves were the only converters who were symptomatic. The significance of skin test conversions identified in the powder-free group, both asymptomatic patients, is unclear. The limitations of the study are discussed, including the limited power, the declines in latex protein concentrations, and the possibility of information (observer) bias.

CONCLUSION

To our knowledge, this represents the first reported estimate (about 1%) of incidence of sensitization in hospital personnel using latex gloves.

Barrier durability of latex and vinyl medical gloves in clinical settings

This study evaluated changes in the tensile strength and barrier integrity of medical gloves during hospital clinical use. Nonsterile vinyl, sterile vinyl, and nonsterile natural rubber latex gloves were collected after use in a clinical setting and then tested for tensile strength, elongation, and water leakage. Tensile properties of vinyl gloves did not change during use, whereas changes in latex depended on the brand evaluated. New gloves, regardless of material of manufacture, were found to have leakage rates of 2% or less. Two brands of nonsterile vinyl gloves were found to have an average rate of leakage after use of 24 to 28% (average 26%), three brands of latex gloves of 6 to 10% (average 8%), and one brand of sterile vinyl gloves of 3%. Low-protein powderless latex gloves leaked slightly less than the powdered brands. The high rates of leakage observed for nonsterile vinyl gloves indicate that they provide less barrier protection than latex in typical hospital use. The low leakage rate observed for sterile vinyl gloves indicates that barrier durability is not solely a function of the generic polymer composition of the barrier.

Endothelin expression in ocular tissues of diabetic and insulin-treated rats

PURPOSE

The endothelins are potent vasoactive peptides that are widely distributed in ocular tissues. There is evidence linking the endothelins to vascular dysfunction in diabetic microangiopathy. Thus, the synthesis and distribution of endothelin-1 (ET-1) and endothelin-3 (ET-3) were studied in the retinas of diabetic and nondiabetic animals.

METHODS

Levels of ET-1 and ET-3 were determined by radioimmunoassay in ocular tissues of normal rats, and in rats with streptozotocin-induced diabetes of 6 and 12 weeks' duration, insulin-treated and untreated. In a separate cohort of similarly treated animals, retinal vascular trypsin digest preparations were immunostained, using antibodies raised against ET-1 and ET-3.

RESULTS

Ocular ET-1 levels were elevated twofold in diabetic animals that received insulin treatment for 7 days when compared with levels in normal rats. Insulin treatment for 10 days before death caused a fourfold elevation of ET-1 in ocular tissues. Endothelin-1 was also increased in 12-week-old diabetic animals and in those maintained on insulin throughout their period of diabetes. Immunofluorescence to anti-ET-1 within the capillary bed and veins of the retina in diabetic insulin-treated animals was elevated when compared with digests from normal litter-matched control animals. Ocular tissue ET-3 levels were unaffected by diabetes.

CONCLUSIONS

Overall ocular and retinal tissue levels of ET-1 were selectively elevated by diabetes and insulin treatment, suggesting that the endothelins may be involved in the pathogenesis of diabetic retinal microangiopathy.

Latex allergy: epidemiological study of 1351 hospital workers

OBJECTIVE

To determine the prevalence of latex sensitisation among a large group of healthcare workers, study the occupational and non-occupational factors associated with latex allergy, and characterise latex exposure in air and by gloves.

METHODS

All 2062 employees of a general hospital in Hamilton, Ontario, Canada who regularly used latex gloves were invited to participate in a cross sectional survey, representing the baseline phase of a prospective cohort morbidity study. Attempts were made to recruit employees who were diagnosed with latex allergy before the survey. Glove extracts were assayed for antigenic protein, and area and personal air samples were obtained on two occasions (summer and winter) to estimate exposure to airborne latex protein. A questionnaire on medical and occupational information was administered by an interviewer. Skin prick tests were performed with latex reagents, three common inhalants, and six foods.

RESULTS

The mean (SD) latex protein concentrations were 324 (227) micrograms/g in powdered surgical gloves and 198 (104) micrograms/g in powdered examination gloves. Personal latex aeroallergen concentrations ranged from 5 to 616 ng/m3. There was a total of 1351 (66%) participants. The prevalence of positive latex skin tests was 12.1% (95% confidence interval (95% CI) 10.3% to 13.9%). This prevalence did not vary by sex, age, hospital, or smoking status but subjects who were latex positive were significantly more likely to be atopic (P < 0.01). Participants who were latex positive were also significantly more likely to have positive skin tests to one or more foods (Mantel-Haenszel odds ratio (OR) adjusted for atopy 12.1, 95% CI 7.6 to 19.6, P < 10(-9)). Work related symptoms were more often reported among latex positive people, and included hives (OR 6.3, 95% CI 3.2 to 12.5), eye symptoms (OR 1.9, 95% CI 1.2 to 2.8), and wheezy or whistling chest (OR 4.7, 95% CI 2.8 to 7.9). The prevalence of latex sensitivity was highest among laboratory workers (16.9%), and nurses and physicians (13.3%). When the glove consumption per healthcare worker for each department was grouped into tertiles, the prevalence of latex skin test positivity was greater in the higher tertiles of glove use for sterile (surgical) gloves (P < 0.005) but not for examination gloves.

CONCLUSIONS

In this large, cross sectional study of healthcare workers, the prevalence of latex sensitisation was 12.1% (9.5% among all those eligible), and there were significant associations with atopy, positive skin tests to certain foods, work related symptoms, and departmental use of gloves per healthcare worker. This cohort is being followed up prospectively and will be retested to determine the incidence of development of latex sensitivity.

Honeydew sugars and osmoregulation in the pea aphid Acyrthosiphon pisum

Pea aphids, Acyrthosiphon pisum, containing their symbiotic bacteria (untreated aphids) and experimentally deprived of their bacteria by treatment with the antibiotic rifampicin (antibiotic-treated aphids) were reared on the plant Vicia faba. The sugars in the honeydew produced by untreated aphids comprised predominantly the monosaccharides glucose and fructose, while the honeydew of antibiotic-treated aphids contained considerable amounts of oligosaccharides of up to 16 hexose units. The honeydew and haemolymph of the aphids were iso-osmotic, and their osmotic pressure was significantly lower in untreated aphids (0.91&shy;0.95 MPa) than in antibiotic-treated aphids (1.01&shy;1.05 MPa) (P&lt;0.05). For insects reared on chemically defined diets containing 0.15&shy;1.0 mol l-1 sucrose (osmotic pressure 1.1&shy;4.0 MPa), the osmotic pressure of the aphid haemolymph did not vary with dietary osmotic pressure, but was regulated to approximately 1.0 MPa in untreated and 1.3 MPa in antibiotic-treated aphids. The sugars in the aphid honeydew varied with dietary sucrose concentration; with monosaccharides dominant at low concentrations and oligosaccharides dominant at high concentrations of dietary sucrose. The lowest dietary sucrose concentration at which honeydew oligosaccharides were detected was 0.2 mol l-1 for the antibiotic-treated aphids and 0.3 mol l-1 for untreated aphids. These data indicate that the aphid, and not its associated microbiota, mediates the synthesis of oligosaccharides when the osmotic pressure of the ingesta is high.

Doctors' retainer scheme in Scotland: time for change?

OBJECTIVES

To describe the present doctors' retainer scheme in Scotland and ascertain the need for change.

DESIGN

Semistructured postal questionnaires to current and past members of the doctors' retainer scheme and general practitioner employers.

SETTING

Scotland, October to December 1994.

SUBJECTS

152/160 current and 104/124 former members responded together with 101/118 general practitioner employers.

RESULTS

93% of members currently working in general practice were either vocationally trained or had previously worked as principals. 84% of current members held postgraduate qualifications. 73% of former members had left the scheme within 4 years and 72% of current members had been with the scheme for 4 years or less. 66% of current members said that the scheme prevented them from leaving medicine. Both members and employers were dissatisfied with the current limit of two working sessions per week, 77% of employers wanting it increased. 61% of current members would not have joined the scheme if suitable part time work had been available and 46% of those would have preferred to work flexibly, up to 5 sessions per week. 52% of members do not receive BMA rates of pay and, of those, 46% work more than 3.5 hours per session.

CONCLUSION

The scheme appears to be appreciated and would be more so if inconsistencies in pay and conditions were addressed. An increase in the permitted number of weekly sessions would enable these highly qualified doctors to maintain their skills and confidence.

Differential sexual activity of isolated and group-housed male mice: lack of substantial influence of acute or chronic naloxone administration

Influences of naloxone upon male sexual behavior were examined using two different baseline activity levels: individually and group-housed mice. In Experiment 1, single injections of 0,12.5, or 50 micrograms per animal were administered before testing. Isolated mice showed more sexual activity than did grouped mice; naloxone failed to alter those differences. In Experiment 2, a similar result was obtained despite administration of 50 or 150 micrograms per animal of naloxone. In Experiment 3,0 or 50 micrograms of naloxone was administered to isolated or grouped males daily on the 5 days before testing. Isolated mice showed performance superior to that of grouped mice, but there was no effect of the drug. In Experiment 4, doses of 0. 12.5, or 50 micrograms of naloxone were given to isolated or grouped males twice daily for 7 days prior to testing, producing little effect. These results suggest that the influences of prior social condition on male sexual activity are robust in the face of naloxone administration.

Classification of deletions and identification of cryptic translocations involving 7q by fluorescence in situ hybridization (FISH)

Monosomy 7 (-7) and deletion of the long arm of chromosome 7, del(7q), are frequent non-random findings in the myelodysplastic syndromes (MDS) and acute myeloid leukaemia (AML), particularly associated with therapy-related disease (t-MDS and t-AML). The cytogenetic breakpoints of 7q deletions are variable, with both terminal and interstitial deletions reported. It is now believed that most deletions are interstitial, and that the variability in reported breakpoints may be due to the difficulty in determining whether the terminal, pale staining G band is present. It has also been suggested that some reported deletions of 7q may be cryptic translocations. To address these questions, we carried out fluorescence in situ hybridization (FISH) studies on leukaemic cells from a large series of patients using a chromosome 7-specific paint and a 7q telomere-specific probe. Of the 26 cases studied, seven were 'pure' deletions (ie without the involvement of other chromosomes); four were interstitial and two terminal. One further patient had two clones each with a different deletion: one with a terminal del(7)(q22) and the second with an interstitial del(7)(q32-qter). A further nine cases had unbalanced translocations with deletion of 7q terminal sequences. The remaining 10 cases were translocations and complex rearrangements, some involving interstitial deletions of 7q. In two cases in which del(7q) was reported as the sole cytogenetic abnormality by G-banding, FISH revealed cryptic translocations involving 7q.

Outcome of wheeze in childhood: the influence of atopy

We have previously demonstrated that the adult outcome of childhood asthma differs from that of wheeze occurring only in the presence of infection. This paper examines the role of atopy in relation to outcome. We investigated the atopic status, current symptoms and bronchial reactivity to methacholine of 235 subjects aged 34-40 yrs, originally classified at age 10-15 yrs as having asthma (asthma group), wheeze only in the presence of infection (wheezy group), or no respiratory symptoms (comparison group). Subjects from the original asthma group were more likely to be atopic as defined by skin test reactivity, total serum immunoglobulin E (IgE) measurement or specific IgE radio allergosorbent test (RAST) measurement than those from the wheezy group. The wheezy group differed significantly from the reference group only in RAST results, when other variables were taken into account. In a logistic regression model, the important independent predictors for adult wheezing symptoms were original group, atopy and current smoking. Methacholine responsiveness was independently associated with original group (the asthma group were more likely to respond positively), atopy and female gender. The results suggest that atopy is an important predictor for wheeze and bronchial hyperreactivity in middle age. However, the difference in outcome for children who had asthma compared to those who had wheeze only in the presence of infection cannot be explained by atopy alone.

Creatine and nucleoside triphosphates in rat cerebral gray and white matter

In vivo localized nuclear magnetic resonance spectroscopy has shown three-fold higher phosphocreatine/nucleoside triphosphate (PCr/NTP) ratios in cerebral white compared to gray matter. To interpret these results, total creatine (Cr) and ATP concentrations were measured enzymatically in samples taken from rapidly frozen rat cerebral cortex and corpus callosum. Total Cr (PCr plus Cr) and ATP concentrations were the same in the two regions. High performance liquid chromatography showed similar concentrations of total NTP in the two regions. These results suggest that higher in vivo PCr/NTP ratios in white compared to gray matter may be due to a higher PCr/Cr ratio in white matter and/or higher percentages of non-adenine mono- or diphosphate nucleotides in gray matter.

Effects of low doses and low dose rates of external ionizing radiation: cancer mortality among nuclear industry workers in three countries

Studies of the mortality among nuclear industry workforces have been carried out, and nationally combined analyses performed, in the U.S., the UK and Canada. This paper presents the results of internationally combined analyses of mortality data on 95,673 workers (85.4% men) monitored for external exposure to ionizing radiation and employed for 6 months or longer in the nuclear industry of one of the three countries. These analyses were undertaken to obtain a more precise direct assessment of the carcinogenic effects of protracted low-level exposure to external, predominantly gamma, radiation. The combination of the data from the various studies increases the power to study associations between radiation and specific cancers. The combined analyses covered a total of 2,124,526 person-years (PY) at risk and 15,825 deaths, 3,976 of which were due to cancer. There was no evidence of an association between radiation dose and mortality from all causes or from all cancers. Mortality from leukemia, excluding chronic lymphocytic leukemia (CLL)--the cause of death most strongly and consistently related to radiation dose in studies of atomic bomb survivors and other populations exposed at high dose rates--was significantly associated with cumulative external radiation dose (one-sided P value = 0.046; 119 deaths). Among the 31 other specific types of cancer studied, a significant association was observed only for multiple myeloma (one-sided P value = 0.037; 44 deaths), and this was attributable primarily to the associations reported previously between this disease and radiation dose in the Hanford (U.S.) and Sellafield (UK) cohorts. The excess relative risk (ERR) estimates for all cancers excluding leukemia, and leukemia excluding CLL, the two main groupings of causes of death for which risk estimates have been derived from studies of atomic bomb survivors, were -0.07 per Sv [90% confidence interval (CI): -0.4, 0.3] and 2.18 per Sv (90% CI: 0.1, 5.7), respectively. These values correspond to a relative risk of 0.99 for all cancers excluding leukemia and 1.22 for leukemia excluding CLL for a cumulative protracted dose of 100 mSv compared to 0 mSv. These estimates, which did not differ significantly across cohorts or between men and women, are the most comprehensive and precise direct estimates of cancer risk associated with low-dose protracted exposures obtained to date. Although they are lower than the linear estimates obtained from studies of atomic bomb survivors, they are compatible with a range of possibilities, from a reduction of risk at low doses, to risks twice those on which current radiation protection recommendations are based.(ABSTRACT TRUNCATED AT 400 WORDS)

Peptide motif of a cattle MHC class I molecule

A consensus motif for a bovine major histocompatibility complex (MHC) class I molecule, A20, was derived from parainfluenza type-3 (PI-3) virus-infected muscle-derived fibroblast cells and peripheral blood leukocytes by extraction of the naturally processed peptides from MHC class I molecules by treatment with TFA and peptide sequencing of the complex mixture. The results showed that the majority of peptides were 9 amino acids long with position 2 occupied by lysine and position 9 occupied by arginine. The arginine at position 9 suggests that cattle, like humans, but unlike the mouse have permissive TAP transporter molecules accepting peptides with positively charged amino acids at their C-terminus. This is the first report of a MHC ligand motif in cattle.

Quantitative analysis of hyaluronan in vitreous humor using capillary electrophoresis

Capillary electrophoresis was used for the separation and quantitative analysis of the glycosaminoglycan hyaluronan in human and bovine vitreous with detection by UV absorbance at 200 nm. Calibration was carried out using standards made up from known concentrations of hyaluronan of umbilical cord origin. The purity of the standard was examined by 1H NMR (nuclear magnetic resonance). Concentrations as low as 25 micrograms/mL could be detected by capillary electrophoresis. Confirmation that the signal was due to hyaluronan was obtained by depolymerization of the native mucopolysaccharide by hyaluronidase. This resulted in loss of the hyaluronan peak and appearance of several new peaks corresponding to the oligomeric fragments which had shorter migration times. Capillary electrophoresis is a reproducible and sensitive technique for the quantification and characterisation of hyaluronan in vitreous samples.

Combined analysis of mortality in three United Kingdom nuclear industry workforces, 1946-1988

Mortality during 1946-1988 has been analyzed in 75,006 employees of the United Kingdom Atomic Energy Authority, the Atomic Weapons Establishment and the Sellafield plant of British Nuclear Fuels. All-cause mortality was 19% lower than national rates among workers monitored for external radiation exposure and 18% lower among nonmonitored workers. Cancer mortality was also lower than national rates and was similar in the two groups of workers [rate ratio (RR) = 0.96]. Of 29 specific cancer sites examined, only for cancers of the pleura and uterus were there statistically significant excesses of mortality in monitored workers relative to nonmonitored workers [RR = 7.08, two-sided P (2P) = 0.008 and RR = 3.02, 2P = 0.003, respectively]. There was little association between cumulative external radiation and risk of death from all cancers combined 10 or more years after exposure [z for trend = +0.11, one-sided P (1P) = 0.5]. A positive association was observed for leukemia (assuming a 2-year lag between external radiation and increasing risk of death) (1P = 0.009) but not for other cancers associated with external radiation in previous analyses (lung, uterus, prostate and multiple myeloma, all 1P > or = 0.1). Positive associations (1P < or = 0.05) were also observed for melanoma and other skin cancers (1P = 0.03) and ill-defined and secondary cancers (1P = 0.04), but these results are difficult to interpret and, given the number of associations examined, may be chance findings. Estimates of excess relative risk per sievert were -0.02 (95% CI = -0.5-+0.6) for all cancers except leukemia and +4.18 for leukemia (95% CI = +0.4-+13.4). The positive estimates for leukemia contrast with negative values found for workers in the United States, although the confidence intervals obtained in the two studies overlap. While our estimates of risk are compatible with those derived from studies of A-bomb survivors, the statistical uncertainty associated with them is such that the data are consistent with risks ranging from no additional risk to twice the risk for cancers other than leukemia and, for leukemia, from one-fifth to three times the risk in A-bomb survivors.

Outcome of wheeze in childhood. Symptoms and pulmonary function 25 years later

The outcome after 25 yr was studied for three groups of children classified in a random community survey in 1964 as having asthma (121 subjects), wheeze in the presence of infection (167 subjects), or no respiratory symptoms (167 comparison subjects). Approximately 80% of the subjects in each group, now aged 34 to 40 yr, were successfully traced. Current symptoms and smoking habit were recorded by questionnaire, and ventilatory function, peak flow variability, and bronchial reactivity to inhaled methacholine were measured. Subjects who had asthma in childhood were more likely to wheeze (odds ratio [OR] 14.4) or produce phlegm (OR 3.3) than comparison subjects. They also had significantly lower FEV1 values and greater bronchial reactivity than comparison subjects. Adult FEV1 correlated with childhood FEV1 (both expressed as % of predicted) (r = 0.44, p < 0.01). The prognosis for those children who were classed as having wheeze in the presence of infection in 1964 was better than for those who had asthma. Although they also were more likely to report wheeze (OR 3.8) or phlegm (OR 4.4) than comparison subjects, the wheezy symptoms were unlikely to interfere with activities and the ventilatory function and bronchial reactivity to methacholine did not differ from those of comparison subjects. Smokers were more likely to report wheeze (OR 2.0), cough (OR 7.2), and phlegm (OR 3.1) than never-smokers, and current smokers with current wheezy symptoms had significantly reduced FEV1 values, although smoking was not associated with increased methacholine reactivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Humoral and cellular immune response to influenza virus vaccination in aged humans

Aging is characterized by an increased susceptibility to infectious diseases; influenza virus infection, which is easily managed by an intact immune system, represents a life-threatening disease in aged subjects. We studied 18 healthy aged subjects (> 65 years of age), vaccinated yearly with conventional anti-influenza vaccine, and 9 healthy young volunteers (mean age 26 years), without previous anti-influenza vaccination, who were vaccinated with the conventional trivalent 1990 anti-influenza preparation. Six out of the 18 aged individuals received a second boost of the same vaccine about 4 months later. In all subjects, we analyzed the humoral response to type A and B influenza viruses and the influenza type A virus-specific CTL generation. Among the elderly population with a single vaccination, 6 and 5 subjects seroconverted against type A and type B influenza virus respectively. Young subjects seroconverted in 5 cases against type A, and in 5 cases against type B influenza virus. Seroconversion took place after the second vaccination in only one subject, and the antibody production was type A specific. Influenza type A virus-specific CTL activity was significantly lower in aged subjects, compared with the values observed in the young volunteers (p = 0.017). The second vaccination partially restored this immunological impairment. These data clearly demonstrate that the elderly do not have the same ability as younger subjects to mount an antibody response, and generate influenza type A virus-specific CTL after conventional anti-influenza vaccination. Moreover, a double anti-influenza vaccination generates CTL activity levels comparable to young subjects, although it does not seem to substantially modify the antibody production.

Comparison of clock drawing with Mini Mental State Examination as a screening test in elderly acute hospital admissions

Clock drawing is a quick, easy to remember test that is well received by patients. It is a good screening test for Alzheimer's disease in the outpatient setting. We evaluated its usefulness compared with the standard Mini Mental State Examination (MMSE) in elderly acute medical and surgical hospital admissions. Within 48 hours of admission, 117 patients over 70 years old were administered the MMSE and asked to draw a clock. Using the MMSE as the standard, clock drawing had a sensitivity of 77% and a specificity of 87%. Patients with discrepant scores were then further evaluated. The findings suggest that normal clock drawing ability reasonably excludes cognitive impairment or other causes of an abnormal MMSE in elderly acute medical and surgical hospital admissions, where cognitive impairment is common and frequently missed.

Quantitative and cytochemical studies of mast cell proteases in rat ovaries and uteri in various reproductive states

A role for mast cell proteases (RMCP I and II) in the cyclical remodelling of ovarian and uterine tissues of rats was investigated in the oestrous and pregnancy cycles using immunocytochemistry and enzyme-linked immunosorbent assays. The concentrations of RMCP I exceeded that of RMCP II by 100-fold in both tissues, but were always much higher in uteri than ovaries. Most of the protease activity in the uterus was located in the myometrium, whereas it was more focally distributed in the hilus and medulla of the ovary. Protease activity was confined to mast cells identified by metachromatic staining and no single cell contained both proteases. The concentrations of RMCP I and II in the two organs did not fluctuate throughout the 4-day oestrous cycle. Neither were RMCP I concentrations in the uterus altered by administration of diethylstilboestrol to ovariectomized animals, although total amounts per uterus were substantially greater than in the controls. Concentrations of RMCP I were substantially reduced in the uterus after day 6 of pregnancy and rose during the puerperium. The reduction was greater in pregnant than in pseudopregnant horns and tended to be lower in the vicinity of conceptuses than between them. The physiological significance of the lower mast cell protease concentrations is unclear, although their absence may contribute to the decreased protein catabolism during pregnancy.

Pituitary volume in men with concurrent heroin and cocaine dependence

Pituitary gland volume was measured in 16 men between the ages of 26-33 with magnetic resonance imaging. Eight male patients had a Diagnostic and Statistical Manual III-Revised, American Psychiatric Association Axis I diagnosis of concurrent opioid and cocaine dependence. The average duration of opioid and cocaine abuse was 7.8 +/- 2.0 and 6.9 +/- 1.4 yr, respectively. All patients were in good physical health as determined by physical examination, blood chemistry, hemogram and hormone analysis, and all tested negatively for the HIV antibody. No patient had any other Diagnostic and Statistical Manual III-Revised Axis I diagnosis or neurological disorder. Eight healthy males served as age-matched control subjects. None of the control subjects had any past or current history of substance abuse or any clinical indication for magnetic resonance imaging. Opioid and cocaine dependent men had significantly larger pituitary gland volumes (730.0 +/- 24.4 mm3) than control subjects (540.0 +/- 26.6 mm3) (P < 0.01). The significant increase in pituitary gland volume in men who abuse opiates and cocaine may be antecedent to detection of abnormal anterior pituitary hormone function.