Use of psychoactive substances in three medical specialties: anaesthesia, medicine and surgery.

In order to determine the prevalence of psychoactive substance use in three specialty groupings, 1,624 questionnaires were sent to physicians in medicine, surgery and anaesthesia; all had trained at the same academic institution. A response rate of 57.8% was achieved. Comparison of prevalence of impairment rates showed no differences between Surgery (14.4%), Medicine (19.9%) and Anaesthesia (16.8%). Substance abuse was clearly associated with a family history of abuse; 32.1% of the abusers had a family history of such abuse compared with 11.7% of the non-abusers. Increased stress at various career stages did not appear to increase substance abuse; problem areas during medical life times were similar for each specialty. Substances most frequently used were marijuana (54.7%), amphetamines (32.9%); and benzodiazepines (25.1%). Seventy-three used psychoactive drugs which were non-prescribed. Drug counselling programmes were judged inadequate by most. Use of alcohol and drugs by faculty members was reported by a number of respondents.

Psychoactive substance use among American anesthesiologists: a 30-year retrospective study.

The purpose of this study was to assess the cumulative incidence of substance use among anesthesiologists during training and practice, the effect of stress on drug use, and deterrent efficacy of institutional prevention programmes. The 260 anesthesiologists who had trained at the Medical College of Wisconsin between 1958-1988 were surveyed by mail regarding psychoactive substance use. Analysis of 183 responses focused on demographic and psychosocial factors. Substances used most frequently included: alcohol (91.6%), marijuana (30.8%) and cocaine (9.4%). Twenty-nine (15.8%) anesthesiologists were identified as being substance-dependent: 19 were alcohol-impaired; six were drug-impaired, and four were dependent on both alcohol and drugs. Impairment was more prevalent in anesthesiologists who had completed their training after 1975. Fifty-eight (32%) anesthesiologists had used illicit drugs to "get high"; 11 acknowledged daily use for two weeks or more, with eight admitting dependency. Substance abuse was more common in parents of impaired anesthesiologists (35.7%) than in unimpaired colleagues (8.1%; P < 0.001). The divorce rate for impaired anesthesiologists (24.1%) was greater than for unimpaired anesthesiologists (5.2%; P < 0.001). Increased stress during training was not reflected by increased substance use. Few recalled any drug counseling whatsoever. Seventy percent assessed hospital drug control policies as fair or poor. Younger respondents (born after 1951) were more critical of drug control programmes than their older cohort. Incidents of substance abuse were reported for both residents and faculty. Psychoactive substance abuse remains a serious problem among anesthesiologists.

Substance abuse by anesthesiology residents.

A 1989 cross-sectional substance abuse survey of 260 former anesthesiology residents of the Medical College of Wisconsin (MCW) during the previous 30 years yielded 183 responses (70.3%). Over three-fourths (77.2%) of those who responded reported that they had used alcohol when they were residents; 20.0% had used marijuana; and 15.7% had used cocaine. Forty-three of the 178 respondents had used unprescribed psychoactive drugs. Twenty-nine (15.8%) had been self-admitted problematic substance abusers during their residencies: 23, alcohol dependent and six, drug dependent; among the latter were four with a dual (alcohol and drug) dependency. More than 85% considered the drug policy information available during their residencies had been inadequate; institutional drug-control policies were rated "fair-to-poor" by more than 70%. Thirty-five of the residents had observed their teachers using alcohol and/or other drugs to the detriment of their teaching; approximately one-third of these infractions had gone unreported.

A worldwide survey of management practices in laboratory animal allergy.

A questionnaire survey of laboratory animal facilities sought to determine employer practices and policies regarding allergy to laboratory animals. Information from 159 American institutions and 93 facilities from 20 other nations indicates that an effective program to control the problem of occupational allergy to laboratory animals remains to be developed.

Retrospective confirmation of Mycoplasma infection by the immunoperoxidase technique.

Rat tissues embedded in paraffin blocks stored for 8-10 yr were sectioned for immunoperoxidase staining. Sections of lung, trachea and endometrium of 22 of 32 rats that had exhibited clinical symptoms of mycoplasmal pneumonia prior to euthanasia, and whose organs had shown gross lesions suggesting mycoplasmal infection on necropsy, demonstrated the presence of Mycoplasma pulmonis organisms by the immunoperoxidase technique in one or more of these tissues.

Spontaneous endometrial tumours of 'Sabra' rats.

In a 2 year study of 171 female (101 virgin; 70 multiparous) 'Sabra' rats, spontaneous endometrial tumours were found in 69% of 2 year old animals. Tumour development appeared to be age related, and only virgin females showed tumours before 18 months of age. Polyps were the most prevalent tumour type, followed by adenocarcinomas. The Sabra rat can be included among those rat strains having a high incidence of spontaneous endometrial neoplasia.

Respiratory disease in animal house workers.

A cross-sectional survey was made to determine the prevalence of respiratory disorders, and the association between symptoms and workplace exposure, in 90 animal-house workers (AHW) and 100 controls (C) without occupational exposure to laboratory animals. Each subject provided a detailed history and serum for radioimmunoassays, and underwent: physical examination, skin testing with common inhalant and animal-derived antigens, and pulmonary function studies. Both groups were comparable with respect to age, sex, smoking habits, and atopy. Rhinitis occurred with similar frequency in each group. However, a more frequent occurrence of asthma (p less than 0.05, non-specific infectious respiratory disease (p less than 0.005), and impaired pulmonary functions (p less than 0.001) was found among AHW. An atopic background was a predisposing factor for the development of laboratory-animal-related respiratory symptoms. These findings imply an increased vulnerability to respiratory disease related to workplace exposure to laboratory animals in atopic individuals.

Occupational respiratory disease in veterinarians.

In order to determine the effect of occupational animal exposure on the occurrence of respiratory disease, we studied 257 active veterinarians and 100 control subjects who had not had occupational animal contact. All participants provided a detailed medical history and underwent spirometry, skin tests, and determination of total serum IgE levels. Asthma was significantly more prevalent in veterinarians (16.3%) than in controls (6%), (P less than .05), as was infectious/obstructive respiratory disease, 10.5% in veterinarians, 3% in controls (P less than .025). Only 13 of 257 veterinarians had respiratory symptoms related to animal contact; of these, seven experienced only allergic rhinitis while six reported both asthma and rhinitis. Animal-related allergic rhinitis was found more frequently in laboratory animal veterinarians than among veterinarians in farm, pet, or poultry practice. No symptoms typical of hypersensitivity pneumonitis were reported in veterinarians, nor were precipitins to animal antigens demonstrable.

Allergenic properties of rat urine and pelt extracts.

We studied the relative diagnostic efficacy of skin tests and RAST assays in laboratory animal allergy in 16 rat-sensitive animal workers with the use of epithelial extract and urinary antigens from three inbred rat strains. RAST inhibition was used to evaluate possible urinary antigen-strain specificity. The urinary antigens were more reliable skin test and RAST reagents than were epithelial extracts; data from urinary antigen testing correlated better with historical data. RAST inhibition did not detect strain specificity among the urinary antigens. Antigens in rat urine appear to be of better diagnostic value than do epithelial extracts.

Resistance to mycobacteria in mice treated with fractionated total lymphoid irradiation (TLI) and in mice reconstituted with allogenic bone marrow cells following radiotherapy.

The increased clinical use of total lymphoid irradiation (TLI) as an immunosuppressive adjunct in transplantation suggested the need for determining the effects of TLI on the in vivo susceptibility of animals to infections controlled by cell-mediated immunity. TLI-treated, TLI-treated and splenectomized, and chimeric mice prepared with TLI were inoculated in the hind foot pad with Mycobacterium marinum or Mycobacterium leprae. Although M. marinum organisms multiplied in greater numbers in the TLI mice, ultimately they were destroyed as effectively in TLI mice as in the non-irradiated control mice. M. leprae multiplied at the same rate and to the same maximum in TLI mice as in controls. Mice previously challenged with M. marinum in one hind foot pad, and challenged subsequently with the same organism in the opposite hind foot pad, showed a solid immunity against this reinfection. It appears that upon recovery from the immediate effects of radiotherapy TLI-treated mice are able to mount an effective immune response to experimental infection with M. marinum and M. leprae.

Experimental mycobacterial infections of CBA/N mice.

In an effort to assess the contribution of B-lymphocyte-mediated mechanisms to the immune responses to several mycobacteria, responses to these intracellular pathogens were compared in immunologically normal CBA/CaHN mice and in histocompatible CBA/N (Xid) mice, which exhibit abnormalities of B-lymphocyte function. Swelling in response to local inoculation with Mycobacterium marinum was significantly greater in the hind feet of CBA/CaHN mice than in those of CBA/N mice, but the difference was very small. Survival of mice of both strains after i.v. challenge with M. marinum or i.p. challenge with M. leprae-murium did not differ significantly. Finally, multiplication of M. leprae in the footpads of mice of both strains did not differ significantly. Thus, B-lymphocyte-mediated mechanisms do not appear to be important in the immune responses of mice in experimental infections with these mycobacterial species.

Response of the popliteal lymph node to reinfection of the hind foot pad of the mouse with Mycobacterium marinum.

In C57BL mice inoculated with Mycobacterium marinum in the right hind foot pad 2 weeks earlier ("previously infected mice"), inoculation of M. marinum into the left hind foot pad was followed by accelerated enlargement of the left popliteal node. Popliteal-node lymphocytes harvested from previously infected donors, labeled with 3H-uridine in vitro, and infused intravenously into previously infected recipients at the time of reinfection in the left hind foot pad homed on the left popliteal node. Similarly, there was an accelerated increase of the number of labeled lymphocytes in the left popliteal node of previously infected mice infused intravenously with 3H-thymidine 24 or 48 hr after reinfection in the left hind foot pad. Accelerated enlargement of the lymph node and the early accumulation of labeled lymphocytes in the popliteal lymph node draining the foot pad reinfected with M. marinum appeared more likely to have resulted from influx and accumulation of lymphocytes than from local proliferation, especially as the lesion of the left hind foot pad is a very modest one, and the quantity of antigen in the left hind foot pad and draining node is very small. The accumulation of lymphocytes, which is the cause of the accelerated node enlargement, appears to require the presence of both antigen and antigen-reactive lymphocytes.

The Sabra rat: definition of a laboratory animal.

Study objectives were to provide investigators of the biomedical research community with comprehensive and reliable baseline data for the Sabra rat strain. In addition to a physiological, developmental, hematological and biochemical definition of this laboratory rat, widely used at the Hebrew University and other research laboratories in Israel, a historical insight offers some understanding of the origin and development of this strain. Data collected from 331 male and female rats over a 2-year period characterize the Sabra rat as a useful, stable, economical laboratory animal with good viability under conventional conditions.

Occupational asthma in poultry workers.

Sixteen poultry workers with poultry house--related rhinitis and/or asthma underwent clinical and laboratory evaluation that included history and physical examination, skin tests with common inhalant and PAg, total- and specific-IgE levels, and pulmonary-function studies. Sixteen age- and sex-matched atopic subjects who were not occupationally exposed to poultry and 12 asymptomatic veterinarians with occupational exposure to poultry served as controls. Rhinitis and asthma developed only in symptomatic poultry workers after exposure to poultry; only in these individuals could immediate wheal-and-flare reactions to poultry antigens be detected (p less than 0.001). The elapsed time between the initial poultry exposure and the onset of poultry house--related symptoms averaged 10 yr. In the symptomatic poultry workers, immediate skin test reactivity and RAST reactions were most frequently associated with NFM. The association between respiratory symptoms temporally related to poultry house exposure and the demonstrable IgE antibody-mediated reaction suggests a relationship between the two.

Occupational asthma due to poultry mites.

The possible role of the northern fowl mite (NFM) in occupation-related respiratory disease of poultry workers was examined. The study population included 16 poultry workers with workplace-associated asthma and rhinitis, 27 atopic individuals with similar symptoms but no occupational exposure to poultry, and 12 asymptomatic nonatopic poultry-exposed controls. Ten of the 16 atopic poultry workers had immediate wheal-and-flare reactions to NFM, as compared with two of 27 non-poultry-exposed controls (p less than 0.001). In cutaneous testing with five poultry-related antigens, the NFM was the most reactive. On skin tests, four atopic poultry workers were positive for NFM and negative for Dermatophagoides farinae; four workers were negative for NFM and positive for D. farinae. Radioallergosorbent test (RAST) showed specific IgE levels for NFM, with positive RAST scores in 60% of poultry workers having positive skin tests. A provocative bronchial test with NFM extract in a poultry worker having positive NFM skin test and RAST score resulted in an immediate 25% reduction in the FEV1 and a 62% fall in forced expiratory flow volume at 25% of vital capacity. Collectively, the established presence of NFM in the poultry workplace, associated clinical histories, positive cutaneous tests, positive specific-IgE assays, and positive bronchial challenge combine to establish a role for NFM in occupational allergic respiratory disease of poultry farmers.

Occupational allergy to laboratory animals: employer practices.

Occupational asthma from exposure to laboratory animals has recently been recognized as a compensable prescribed disease in Britain. Current American employer attitudes and policies regarding laboratory animal allergy were surveyed by questionnaire and the findings compiled from 155 institutions. Laboratory animal allergy was reported as a workplace disease of animal house employees by 108 facilities (70%), with rat and rabbit exposure the most frequent cause. While 103 of 155 animal research facilities required a preemployment medical examination, only six of these included hypersensitivity screening. Applicants for jobs involving animal contact were rarely disqualified because of an allergic history. A uniform policy regarding the problem of allergy to laboratory animals in U.S. animal facilities is not presently apparent.

Effects of experimental hyperlipoproteinaemia on the retina and optic nerve in rhesus monkeys.

Hyperlipoproteinaemia resulting from thyroid suppression and long-term ingestion of a high cholesterol diet caused prolonged lipaemia retinalis in 6 rhesus monkeys. No atherosclerotic deposits or other ophthalmoscopically visible changes of the retinal vasculature were detectable. In 2 animals histopathological examination revealed segmental atrophy and gliosis of the optic nerves bearing a resemblance to chronic ischaemic optic neuropathy. One monkey developed ophthalmoscopically visible temporal pallor of the optic discs. Emboli of fat laden cells in blood vessels of the brain in one of these 2 monkeys, and in a penicillated splenic artery in the other animal, were associated with signs of systemic embolic occlusion, suggesting a similar course in the development of optic nerve damage.