A multicentre, prospective, randomised, blinded clinical trial to compare some perioperative effects of buprenorphine or butorphanol premedication before equine elective general anaesthesia and surgery

Reasons for performing study

Buprenorphine, a μ‐agonist opioid, has recently been licensed for equine use, but butorphanol, a κ‐agonist opioid, is more commonly used in horses. The effect of the 2 opioids has not previously been compared in a large clinical study.

Objectives

To compare post operative analgesia and physiological variables in horses undergoing elective surgery following premedication with either buprenorphine or butorphanol in a conventional clinical setting.

Study design

Multicentre, prospective, randomised, blinded clinical investigation.

Methods

Eighty‐nine healthy horses admitted for elective surgery to one of 6 UK equine veterinary clinics were premedicated with acepromazine, a nonsteroidal anti‐inflammatory drug, and romifidine followed by intravenous (i.v.) buprenorphine or butorphanol. Anaesthesia was induced with diazepam/ketamine and maintained with isoflurane in oxygen. A range of surgical procedures were performed and supplementary anaesthetic agents given as required. Physiological variables were monitored during anaesthesia and pain, ataxia, sedation and vital function were assessed post operatively. Data were analysed using t‐tests, ANOVA, Mann–Whitney U‐test and Chi‐squared test as appropriate and P<0.05 was regarded as significant, except for multiple comparisons, when P<0.01 was used.

Results

Surgery was carried out successfully in all cases and no mortality or serious morbidity occurred. Physiological variables remained within normal limits and all horses recovered successfully, most standing within 1 h of ceasing anaesthesia. There were no significant differences between groups in any variable except post operative pain when scores (simple descriptive scale) between 3 and 6 h were significantly lower after buprenorphine than after butorphanol.

Conclusions

Horses experienced less post operative pain after buprenorphine than after butorphanol premedication. Compared with butorphanol, buprenorphine did not cause any different effects on vital function.

Effects of acepromazine, butorphanol and buprenorphine on thermal and mechanical nociceptive thresholds in horses

REASONS FOR PERFORMING STUDY

To investigate the antinociceptive effects of buprenorphine administered in combination with acepromazine in horses and to establish an effective dose for use in a clinical environment.

OBJECTIVES

To evaluate the responses to thermal and mechanical stimulation following administration of 3 doses of buprenorphine compared to positive (butorphanol) and negative (glucose) controls.

METHODS

Observer blinded, randomised, crossover design using 6 Thoroughbred geldings (3-10 years, 500-560 kg). Thermal and mechanical nociceptive thresholds were measured 3 times at 15 min intervals. Horses then received acepromazine 0.05 mg/kg bwt with one of 5 treatments i.v.: 5% glucose (Glu), butorphanol 100 µg/kg bwt (But) buprenorphine 5 µg/kg bwt (Bup5), buprenorphine 7.5 µg/kg bwt (Bup7.5) and buprenorphine 10 µg/kg bwt (Bup10). Thresholds were measured 15, 30, 45, 60, 90, 120, 150, 180, 230 min, 4, 5, 6, 7, 8, 9, 10, 11, 12 and 24 h post treatment administration. The 95% confidence intervals for threshold temperature (ΔT) for each horse were calculated and an antinociceptive effect defined as ΔT, which was higher than the upper limit of the confidence interval. Duration of thermal antinociception was analysed using a within-subjects ANOVA and peak mechanical thresholds with a general linear model with post hoc Tukey tests. Significance was set at P<0.05.

RESULTS

Mean (± s.d.) durations of thermal antinociception following treatment administration were: Glu 0.5 (1.1), But 2.9 (2.0), Bup5 7.4 (2.3), Bup7.5 7.8 (2.7) and Bup10 9.4 (1.1) h. B5, B7.5 and B10 were significantly different from Glu and But. No serious adverse effects occurred, although determination of mechanical thresholds was confounded by locomotor stimulation.

CONCLUSIONS

Administration of acepromazine and all doses of buprenorphine produced antinociception to a thermal stimulus for significantly longer than acepromazine and either butorphanol or glucose.

POTENTIAL RELEVANCE

This study suggests that buprenorphine has considerable potential as an analgesic in horses and should be examined further under clinical conditions and by investigation of the pharmacokinetic/pharmacodynamic profile.

Assessment of the sedative effects of buprenorphine administered with 10 μg/kg detomidine in horses

The aim of this randomised, observer-blinded, crossover study was to compare the effects of six treatments, administered intravenously to six horses: saline and saline (S/S); detomidine and saline (D/S); detomidine and 5 µg/kg buprenorphine (D/B5); detomidine and 7.5 µg/kg buprenorphine (D/B7.5); detomidine and 10 µg/kg buprenorphine (D/B10); and detomidine and 25 µg/kg butorphanol (D/BUT). The detomidine dose was 10 µg/kg for all treatments in which it was included. Sedation was subjectively assessed and recorded on a visual analogue scale. Peak sedation, duration of sedation and the area under the curve (AUC) for sedation scores were investigated using a univariate general linear model with post-hoc Tukey tests (P<0.05). Peak sedation and duration of sedation were statistically significantly different between treatments (P<0.001). No sedation was apparent after administration of S/S. The AUC was significantly different between treatments (P=0.010), with S/S being significantly different from D/S, D/BUT, D/B5 and D/B7.5, but not D/B10 (P=0.051).

Recovery characteristics following maintenance of anaesthesia with sevoflurane or isoflurane in dogs premedicated with acepromazine

A standard anaesthetic protocol was used to anaesthetise 40 dogs for intravenous urography and a retrograde urethrogram or vaginourethrogram. The dogs were allocated by blocked randomisation to receive either isoflurane or sevoflurane for maintenance of anaesthesia after they had been premedicated with acepromazine and pethidine, and anaesthesia induced with propofol. An observer who was unaware of which agent had been used assessed ataxia 30 and 60 minutes after discontinuation of administration of the anaesthetic and assigned an overall recovery score. No complications occurred during anaesthesia of either group of dogs. The scores for ataxia were significantly lower after 60 minutes than after 30 minutes, but there was no significant difference between the groups. The quality of recovery was significantly better in the dogs that received sevoflurane than in those that received isoflurane, but the recovery times were similar.

[Predictive equations and analysis of influence factors of lung ventilation based on a large occupational population in North China]

OBJECTIVE

To establish suitable predictive equations of lung function for occupational population in North China.

METHODS

A total of 5 002 on the job or retired healthy adults from five enterprises in North China with category of mild or moderate work intensity underwent spirometry using a Chest HI-198 spirometer and the procedures recommended by the American Thoracic Society, were a sample.

RESULTS

The data of 3 913 subjects were used. A normal distribution of our data was shown using the normality test and distribution curve. Univariate analysis showed that both age and height were significantly correlated with FVC, FEV(1), FEV(1)/FVC (%) and MMF. Further multiple linear stepwise regression analysis indicated that the levels of FVC, FEV(1), FEV(1)/FVC (%) and MMF were highly influenced by age, height, and weight rather than chest circumference. Thus, only age, height, and weight were introduced into our regression equations. Data from the studied subjects and other source were utilised to examine the validity of the equations and a high accordance rate (> 90%) was obtained. No significant difference (P > 0.05) was found in the predictive values between the simplified equations and equations in which more variables were included.

CONCLUSION

The studied predictive equations for male non-smokers, female non-smokers, and male smokers were established based on data from a large occupational population. These equations should be more applicable for evaluating lung ventilatory function of occupational populations in North China.

[Changes in bronchoalveolar lavage fluid of rats exposed to metal grinding dusts]

OBJECTIVE

To investigate the effects of composite grinding dusts on rat respiratory system.

METHODS

Rats were administrated with grinding dusts by intratracheal injection. After 2 weeks, the total numbers of cells, the percentage of differential cell, the survival rate of cell, and the activity of lactate dehydrogenase(LDH) and alkaline phosphatase(ALP) in bronchoalveolar lavage fluid were analyzed.

RESULTS

Along with increasing concentration of grinding dusts, the total number of cells in lavage also increased, and was more than that in quartz group. Compared with control group, the percentage of neutrophil in lavage of rats treated with grinding dust and quartz significantly increased and meanwhile that of macrophage significantly decreased[PMN: quartz group (33.83 +/- 4.54)%; grinding dusts group (26.50 +/- 3.99)%, (36.00 +/- 3.58)%, (38.00 +/- 2.10)% at 10, 25, 50 mg/ml respectively. Macrophages: quartz group (62.17 +/- 4.54)%; grinding dusts group (70.83 +/- 3.66)%, (60.83 +/- 2.14)%, (58.17 +/- 2.48)%] while those in control group were (2.83 +/- 0.75)%, (95.67 +/- 1.21)% respectively. The cell survival rate in lavage in control group was 80%, but that in grinding dust and TiO2 group significantly decreased(P < 0.01). The activity of LDH and ALP in all rats treated with dusts obviously increased, and there was significant difference compared with control group(P < 0.01 or P < 0.05). Furthermore, there was significant difference between grinding dust group and quartz group, and between grinding dust group and TiO2 group respectively.

CONCLUSION

Metal grinding dust is very harmful to rat's lung cells and may cause fibrogenesis in the lungs.

Cardiopulmonary resuscitation performed in patients with terminal illness in Chiang Mai University Hospital, Thailand

BACKGROUND

The original target of cardiopulmonary resuscitation (CPR) was victims of acute cardiopulmonary arrest. However, the use of CPR has expanded to a wide variety of patients including those with terminal illness for whom CPR is futile. The objective of this study was to identify the incidence of CPR performed, the severity of illness and the outcome of CPR attempted in terminal illness in a teaching hospital.

METHODS

Cardiopulmonary resuscitation attempted in terminal illness was retrospectively assessed from the medical records of hospital deaths with any one of eight life-threatening diagnoses during a 3.5-year period.

RESULTS

Of 532 hospital deaths from terminal illness, 411 records (77.3%) were reviewed and abstracted. Most of the 411 patients had a low pre-CPR functional status. Generally, CPR was performed in 270 (65.7%) cases; 114 of those given CPR (42.2%) initially survived, but all died shortly after the manoeuvre. The high death rate following CPR may reflect both terminal illnesses and the severity of pre-event functional capacity of patients.

CONCLUSION

The criteria for CPR in this group of patients need to be re-assessed and use of a Cerebral Performance Categories (CPC) score may be helpful.

Prediabetes and perinatal mortality

OBJECTIVE

The association between gestational diabetes mellitus (GDM) and perinatal outcome is largely based on case series and retrospective studies that found an increased risk of perinatal mortality and stillbirth as the onset of diabetes approached. Our objective was to assess the relationship between latency to diabetes and perinatal outcome of prediabetic pregnancies in a contemporary population of women with adult-onset diabetes.

RESEARCH DESIGN AND METHODS

A population of 403 diabetic women from two recruitment sites completed a pretested questionnaire.

RESULTS

Details of 1,181 pregnancy outcomes were obtained. This comprised 1,024 live births, 22 stillbirths, and 8 early neonatal deaths. Crude analysis suggested a relationship between time to diabetes (latency) < or =20 years and both perinatal death and stillbirth: odds ratio (95% CI), 2.41 (1.17-4.95) and 2.15 (0.93-4.98). Generalized additive modeling revealed a nonlinear relationship between the variables time to diabetes, and maternal age and perinatal outcome. Final logistic regression analysis was then performed for the outcomes perinatal death and stillbirth, with maternal age as a second-degree polynomial, year of birth as a continuous variable, and time to diabetes dichotomized < or =20 years to diagnosis and >20 years. This final analysis documented a significant association between time to diabetes < or =20 years and both perinatal death (4.06 [1.79-9.36]) and stillbirth (3.35 [1.25-9.05]).

CONCLUSIONS

There appeared to be an increased risk of perinatal death and stillbirth in pregnancies occurring in the last 20 years before the diagnosis of diabetes.

Optimal timing of cleft palate closure

Treatment objectives for the cleft palate patient--normal speech, normal maxillofacial growth, and normal hearing--are closely related. Controversy about the timing of cleft palate surgery is directed at the need for early palatoplasty for improved speech and hearing versus delayed hard palate repair for undisturbed facial growth. This controversy as to the value of early versus delayed closure continues into the present. The authors present an updated argument regarding this controversy along with a comprehensive literature review. They also present a logical algorithm based on the literature and their personal experience.

Mortality among involuntarily admitted psychiatric patients: a survival analysis

BACKGROUND

Only a few studies have examined mortality among committed psychiatric patients, and most of them suffer methodologically from selected populations, small samples, and inappropriate methods of data analysis. The purpose of this study was to determine whether involuntarily admitted psychiatric inpatients are a high risk group for mortality compared to a group of voluntarily admitted psychiatric inpatients.

METHOD

A retrospective cohort design was used with a maximum 9-year variable follow-up. A multistage sampling procedure was used to generate the sample, which consisted of 1064 involuntarily admitted patients and 1078 voluntarily admitted patients.

RESULTS

During the follow-up period, 107 deaths were identified, 58 involuntary and 49 voluntary [chi 2 (1) = 0.9255, P = 0.336]. No significant differences were observed between the cohorts when survival analysis was used to examine survival experiences in the community.

CONCLUSIONS

Compared to voluntary patients, involuntary patients do not appear to be at a higher risk for mortality. The high standard mortality ratios observed in both cohorts, however, are consistent with previous findings of high mortality among psychiatric patients in general, and support the need for intensive follow-up in the community following discharge from a psychiatric inpatient unit.

[Sequencing and analysis of the NS5 region of HGV/GBV-C gene]

To study the genomic organization of non structural region 5 of HGV in China, 186 nucleotides of NS5 region of HGV were amplified, cloned and sequenced. The data were analyzed with computer programs. The results indicated that the gene sequence homology between 2 HGV isolates in this study was 95.2%. The comparison of these 2 isolates and 3 foreign isolates reported previously showed that the sequence homology was in the range of 84.4% to 92.4%, and was obvious by divergent from the foreign isolates. The results make us consider that HGV may have different genotypes, after a further inspection into the gene sequence of each region of HGV. The 2 isolates were from the sera collected in 1984, therefore the existence of HGV infection in Harbin was retrospectively traced to 1980s.

Suicide following an inpatient hospitalization for a suicide attempt: a Canadian follow-up study

This study contributes a Canadian perspective to a growing body of international studies examining suicide among cohorts of suicide attempters, and a much more limited literature on the epidemiology of suicide in Canada. We evaluated the 13-year mortality experience of a regional cohort of 876 first-ever inpatient hospital admissions for a suicide attempt admitted between 1979 and 1981. Compared to the general population, study subjects were 4 times more likely to die of any cause, but 25 times more likely to commit suicide and 15 times more likely to die of accidental or adverse causes. Ten years after then first hospitalization for attempted suicide, 5.9% of study subjects had committed suicide. Baseline age appeared to be a risk factor for women, but not for men. Women under 60 years had the best 10-year survival (3.6% had committed suicide) and women over 60 years had the poorest (17.5%). A total of 8.7% of men under 60 years and 10% of those over 60 years committed suicide within 10 years. The remainder of the analysis focused on those under 60 years of age at the time of their index inpatient hospitalization. Three factors were prognostic for suicide: being male, which had a relative risk (RR) of 5.0, living in a lower income area (RR = 3.2), and having used a violent method during the index attempt (RR = 2.5). The periods of greatest risk for suicide were within the 1st and 4th years following first-ever inpatient hospitalization, with the 4th year representing the time of highest risk. The identification of time periods subsequent to first-ever hospitalization when patients are at greatest risk of suicide can be used to guide the timing and duration of clinical interventions and aftercare to ensure that patients are appropriately supported during periods of highest risk.

Development, implementation, and validation of the Canadian Intercollegiate Sport Injury Registry

PURPOSE

To outline the development and implementation of the Canadian Intercollegiate Sport Injury Registry (CISIR), to examine its validity, including the data collection forms, the recording of athlete exposure, and the mechanism of injury, and to determine the ability of the CISIR to meet its stated objectives of assessing rates and risk of injury.

DESIGN

Prospective cohort study.

SETTING

Canadian intercollegiate athletics.

SUBJECTS

344 varsity football players from five western Canadian universities. ASSESSMENT OF RISK FACTORS AND OUTCOME MEASURES: Three data collection instruments were developed to capture the principle types of information forming the cornerstones of the CISIR: a medical form for preseason assessment of risk factors, a weekly exposure sheet (WES) for the documentation of daily individual athlete participation, and an individual injury report form (IIRF) for collection of injury-related information. Design and implementation input was provided by therapists and physicians through initial meetings, pilot testing, site visits, questionnaire, and final consensus meeting. The completeness of injury reporting was assessed through cross-referencing with participation time loss data. An item analysis was conducted on the principal elements of the IIRF. The categorization of participation itself was also examined, as was the diagnostic agreement between the therapists and physicians involved in data collection. The recorded mechanism of injury was compared with that noted through a video analysis for game-related injuries. Lastly, a test analysis was conducted to extract data and compute rates and risks of injury.

RESULTS

This developmental phase was successful, with 99.7% subject enrollment, high therapist satisfaction, and good flow of data. A relational database, incorporating dual-entry data verification, was designed and functioned well. The collection process revealed that 100% of the WESs were submitted, and the data therein was 99.7% complete. The injuries resulting in participation time loss were recorded on an IIRF 97.9% of the time. The exposure (participation) codes were thought to be overly precise, and a simplification of these categories is suggested. The diagnostic agreement between physicians and therapists was 70%. It was possible to validate game exposures, but no standard was identified to permit validation of the categories of exposure. Likewise, the mechanism of injury as recorded by the therapists was thought to be more precise than the video analysis. After two modifications in the table structure of the relational database, it was possible to extract data relating to rates and risks of injury.

CONCLUSIONS

This study demonstrated a high degree of validity for many elements of the CISIR. One limitation was that no reference standard existed for some components, limiting some aspects of validity assessment. With the suggested revisions, the CISIR represents the current standard in athletic injury reporting in terms of individual injury risk assessment. This system will be used in the future to explore the prediction and prevention of sport injuries.

Association of semen quality and occupational factors: comparison of case-control analysis and analysis of continuous variables

OBJECTIVE

To compare two statistical approaches, case-control and analysis of continuous parameters of semen, in examining the relationship between occupational exposures and male reproductive function.

DESIGN

Case-control study.

SETTING

Males providing semen samples at a university infertility clinic.

PATIENT(S)

Nonvasectomized males who provided at least one semen sample at an infertility clinic.

MAIN OUTCOME MEASURE(S)

Standard clinical semen analysis.

RESULT(S)

Analyses using a dichotomous dependent variable did not uncover significant associations between any occupational factor and infertility case status. However, linear models incorporating continuous variables identified a number of occupational factors that were associated with specific parameters of semen. A reduction in percentage of progressive sperm and an increase in percentage of coiled tail sperm defects in welders, compared with unexposed subjects, were found. Significant dose-response relationships between level of perceived job stress and percentage of progressive sperm, total motile count, morphology, abnormal heads, and coiled tail defects were found.

CONCLUSION(S)

The findings suggest that subtle changes in semen variables, possibly associated with workplace exposure, may be detected only with parametric analyses of continuous variables of semen.

First year serologic response to treatment for syphilis: a model for prediction of seroreversion

There is no straightforward test available, within weeks of treatment for syphilis, to assess adequacy of serologic response. We propose a method to predict non-treponemal seroreversion based on short term response. To develop and illustrate this method, we used data from 370 individuals with infectious syphilis. Individual serologic response appears to be a linear function of (log) time, suggesting the possibility of using rapid plasma reagin titres recorded in the first few months after treatment to determine the slope of the linear treatment response line. The slope of the response line, during the first year after treatment, is an important predictor of seroreversion but must be considered in conjunction with pre-treatment titre. We recommend development of an action line be developed based on these variables. Such a line would indicate the necessity for retreatment if the line plotted from the patient's first year response failed to fall below the action line.

Athletic injury reporting. Development of universal systems

There are numerous athletic injury reporting systems currently in place. In order for our understanding of athletic injury epidemiology to advance, we must be able to compare data from divergent sources. This paper provides a review of existing athletic injury reporting systems in North America. The epidemiological designs employed in these systems are outlined, along with a description of the strengths and weaknesses of each approach to reporting. The differences between the case-series and cohort methods are delineated and the importance of injury definition, sources of error, denominator data and exposure estimation are discussed within this context. Four recommendations are then offered to assist in moving toward more universal systems for athletic injury reporting. First, comparability of data between systems should be maximised through clear indication of the reporting system design and the methods of data collection. Secondly, an exact definition should be given as to what constitutes a reportable event ('injury'). Thirdly, whenever possible, outcome information should be collected on each reported event so that an injury definition may be applied at the time of data analysis. Lastly, any limitations or sources of error should be acknowledged.

Effect of macrophage stimulation on collagen biosynthesis in the healing wound

Immunomodulators that enhance macrophage function have been shown to be beneficial in a number of wound-healing models in humans and in experimental animals. The exact mechanism of this improved healing is unclear. To assess the role of collagen biosynthesis, the immunomodulator glucan phosphate was utilized in two murine models of wound healing, i.e., colon anastomosis and full-thickness skin incision. Tensile strength was evaluated using computer-assisted constant velocity tensiometry. Collagen biosynthesis was determined by assaying hydroxyproline content of wound hydrolysates by N-(9-fluorenyl)methoxycarbonyl/o-phthalaldehyde high-performance liquid chromatography. Experimental animals were treated with (1-3)-beta-D-glucan phosphate (250 mg/kg) intravenously 24 hours prior to colon anastomosis or skin incision. A second dose of glucan phosphate was given immediately postoperatively. Control animals received dextrose and water (5% w/v) intravenously. Tensile strength and hydroxyproline content were measured on postoperative Day 3. In the skin wound model, glucan phosphate treatment increased (P < 0.05) tensile strength by 42 per cent (342.5 +/- 12.2 vs 241.8 +/- 4.8 g), and hydroxyproline content was increased by 23.5 per cent (242.0 +/- 14.4 vs 196.8 +/- 10.5 pmol/microg; P < 0.05). In the glucan phosphate group, colon tensile strength was significantly (P < 0.05) increased by 34 per cent (34.2 +/- 2.3 g vs 45.8 +/- 2.1 g), and hydroxyproline content was increased by 7 per cent (47.45 +/- 3.31 vs 44.34 +/- 3.74 pmol/microg). These data indicate that macrophage modulation with glucan phosphate will increase tensile strength in experimental colon and skin wounds. In addition, we observed a positive correlation between glucan phosphate treatment, wound tensile strength, and collagen biosynthesis.

Drug-induced depression

BACKGROUND

Certain drugs may contribute to the etiology of depressive symptoms and depressive disorders. The objective of this review is to critically appraise the literature concerned with these potential etiological associations.

METHOD

The review was based on papers uncovered in electronic literature searches using Medline, Psychlit and Psychological Abstracts. Statistical power calculations were used to assist in the interpretation of negative results.

RESULTS

A large number of publications were uncovered, but most of these were case reports. There were relatively few empirical studies. Corticosteroids, certain calcium channel blockers and digoxin have been associated with depression by replicated, well conducted studies. Psychostimulant withdrawal is also associated with prominent depressive symptoms. Preliminary evidence suggests that antihyperlipidemic agents, angiotensin converting enzyme inhibitors, sedative hypnotics, psychostimulants and certain hormonal agents may also cause depression. Despite an extensive literature, the potential association between beta-blockers and depressive symptoms remains controversial. There is no substantial evidence that l-dopa or histamine-2-receptor blockers cause depression and the literature is relatively conclusive in determining that thiazide diuretics are not associated with depressive symptoms.

CONCLUSIONS

A small, but growing, literature confirms that certain drug exposures can contribute to the biopsychosocial etiology of depressive symptoms and disorders. Current beliefs and diagnostic conventions classify drug-induced depression into a distinct category (Substance-Induced Mood Disorder): but this approach is not specifically supported by the existing literature.

Depressive symptoms attributable to medication exposure in a medical inpatient population

OBJECTIVE

Exposure to certain drugs-angiotensin-converting enzyme inhibitors, beta-blockers, calcium channel blockers, corticosteroids. H2 blockers, and sedative hypnotics-may be associated with an increased risk of depression. These drugs are commonly used in inpatient medical therapeutics. Since population attributable risk (PAR) is generally related both to strength of association and to the frequency of exposure to a risk factor, the PAR of depressive symptoms associated with these drug exposures is potentially high. The objective of this study was to estimate the depressive symptoms population attributable risk percent (PAR%) in a medical inpatient population.

METHODS

A prospective cohort design was used in this study. Nondepressed, nondrug-exposed subjects (N = 178) were selected from a series of 369 newly admitted medical inpatients at the Calgary General Hospital. Eighty-six of these 178 subjects were prescribed one of the drugs in question, forming an exposed cohort. The remaining subjects formed a nonexposed cohort. Depressive symptoms and associated psychosocial variables were measured in both subgroups during the hospital stay.

RESULTS

Seventeen of the 86 exposed subjects and 5 of the 92 nonexposed subjects developed incident depressive symptoms during their stay in hospital. The PAR% associated with drug exposure (56.0%) exceeded that associated with poverty (17.9%) or unemployment (21.7%).

CONCLUSIONS

Drug exposures may have a sizeable impact on the incidence of depressive symptoms in medical inpatient populations.

Case-control studies of cardiovascular medications as risk factors for clinically diagnosed depressive disorders in a hospitalized population

OBJECTIVE

Certain medications used in cardiovascular therapeutics may contribute to the etiology of substance-induced mood disorders. These medications include digoxin, angiotensin converting enzyme (ACE) inhibitors, beta-blockers, and calcium channel blockers. The objective of this study was to evaluate associations between these drugs and clinical diagnoses of depressive disorders in a population of hospitalized patients.

METHOD

Two case-control studies were conducted. For each study, subjects were selected from a health records data base maintained at the Calgary General Hospital. Selection of subjects in the first study was restricted to those receiving a discharge diagnosis of congestive heart failure and in the second study to subjects receiving a discharge diagnosis of hypertension. In each of these 2 studies, a single case group was selected along with 2 control groups: a psychiatric control group consisting of subjects receiving a psychiatric diagnosis other than a depressive disorder and a nonpsychiatric control group receiving no psychiatric diagnoses. Drug exposures and other variables were recorded from a chart review.

RESULTS

Exposures to digoxin, beta-blockers, and calcium channel blockers were not associated with depressive diagnoses. An association was observed, however, for ACE inhibitors. An elevated odds ratio (OR) was observed in each case-control study and was stronger in female subjects and subjects over the age of 65.

CONCLUSIONS

This is the first reported epidemiological evidence of an association between ACE inhibitors and depressive disorders. The design of this study does not permit a determination of whether the observed association was causal. Additional studies are needed.

Receptor binding and internalization of a water-soluble (1--&gt;3)-beta-D-glucan biologic response modifier in two monocyte/macrophage cell lines

Glucan phosphate, a water-soluble, chemically defined (1--&gt;3)-beta-D-glucan biologic response modifier, has been reported to exert antisepsis activity and accelerate wound healing. In this study we describe the specific binding of glucan phosphate to human and murine monocyte/macrophage cell lines, U937 and J774A.1, respectively. At 37 degrees C, equilibrium binding was rapidly achieved, i.e., within 1 min. In U937 cells, binding occurred with an affinity (Kd) of 37 microM and a Bmax of 65 x 106 binding sites/cell at 37 degrees C. In J774A.1 cells, glucan phosphate bound with an affinity (Kd) of 24 microM and a Bmax of 53 x 106 binding sites/cell at 37 degrees C. In both cases there was insignificant nonspecific binding. We further demonstrated that bound glucan phosphate cannot be displaced by a 50-fold excess of unlabeled ligand, suggesting internalization of glucan phosphate. Transmission electron microscopy showed significantly increased cytoplasmic vacuolization and significantly decreased mitotic activity in glucan phosphate-treated U937 cells compared with that in untreated cells. Pullulan, a random coil alpha-(1--&gt;4)-(1--&gt;6)-linked glucose polymer that served as a control, did not compete for the same binding site as glucan phosphate in either cell line, indicating the specificity of the binding site for (1--&gt;3)-beta-D-glucans. We conclude that water-soluble pharmaceutical grade (1--&gt;3)-beta-D-glucan phosphate specifically binds to and is internalized by U937 and J774A.1 cells.

Receptor binding and internalization of a water-soluble (1-->3)-beta-D-glucan biologic response modifier in two monocyte/macrophage cell lines

Glucan phosphate, a water-soluble, chemically defined (1-->3)-beta-D-glucan biologic response modifier, has been reported to exert antisepsis activity and accelerate wound healing. In this study we describe the specific binding of glucan phosphate to human and murine monocyte/macrophage cell lines, U937 and J774A.1, respectively. At 37 degrees C, equilibrium binding was rapidly achieved, i.e., within 1 min. In U937 cells, binding occurred with an affinity (Kd) of 37 microM and a Bmax of 65 x 106 binding sites/cell at 37 degrees C. In J774A.1 cells, glucan phosphate bound with an affinity (Kd) of 24 microM and a Bmax of 53 x 106 binding sites/cell at 37 degrees C. In both cases there was insignificant nonspecific binding. We further demonstrated that bound glucan phosphate cannot be displaced by a 50-fold excess of unlabeled ligand, suggesting internalization of glucan phosphate. Transmission electron microscopy showed significantly increased cytoplasmic vacuolization and significantly decreased mitotic activity in glucan phosphate-treated U937 cells compared with that in untreated cells. Pullulan, a random coil alpha-(1-->4)-(1-->6)-linked glucose polymer that served as a control, did not compete for the same binding site as glucan phosphate in either cell line, indicating the specificity of the binding site for (1-->3)-beta-D-glucans. We conclude that water-soluble pharmaceutical grade (1-->3)-beta-D-glucan phosphate specifically binds to and is internalized by U937 and J774A.1 cells.

Self-reported depressive symptoms following treatment with corticosteroids and sedative-hypnotics

OBJECTIVE

To evaluate associations between exposure to corticosteroids or sedative-hypnotic medications and incident self-reported depressive symptoms in medical inpatients.

METHOD

The study utilized a prospective cohort design, focusing on acute depressive symptoms developing soon after medication exposure. The incidence of self-reported depressive symptoms was evaluated using a modified version of the Center for Epidemiological Studies Depression Rating Scale (CES-D). The incidence of depressive symptoms in subjects newly exposed to corticosteroids and sedative-hypnotics was compared to that of a nonexposed comparison cohort.

RESULTS

The incidence of self-reported depressive symptoms was elevated in subjects newly exposed to corticosteroids (Risk Ratio = 3.10), although the association did not attain statistical significance (p = .07). The risk ratio for sedative-hypnotic exposure was 4.18, a statistically significant finding (p = .02). As expected, incident self-reported depressive symptoms were also associated with several psychosocial variables. However, the data did not suggest that the observed associations between drug exposures and depressive symptoms were due to confounding by psychosocial or illness-related variables.

A case-control study of corticosteroid exposure as a risk factor for clinically-diagnosed depressive disorders in a hospitalized population

OBJECTIVE

Depressive symptoms may be a side effect of exogenous corticosteroids. However, the literature does not confirm that corticosteroid exposure is associated with the occurrence of depressive disorders. The objective of this study was to determine whether or not corticosteroid exposures are associated with clinical diagnoses of depressive disorders in hospitalized patients.

METHOD

The study used a case-control design. Cases and 2 control groups were selected from a health records case summary database maintained at the Calgary General Hospital. Additional data were collected by chart review.

RESULTS

The analysis reproduced associations between depressive diagnoses and several psychosocial and biological risk factors. However, the data did not suggest that corticosteroids were associated with an elevated risk of depressive diagnoses. In fact, odds ratios for corticosteroid exposure were less than 1, consistent with a protective effect.

CONCLUSIONS

Although corticosteroids may produce depressive symptoms as a side effect, corticosteroid exposures are not associated with an elevated risk of clinically diagnosed depressive disorders in hospitalized patients. There are several possible explanations for this. Depressive syndromes associated with corticosteroid exposure may not clinically resemble depressive disorders, and may not warrant a diagnosis of a depressive disorder. Alternatively, clinicians may not identify and formally diagnose depressive disorders caused by corticosteroids.

Self-reported depressive symptoms in association with medication exposures among medical inpatients: a cross-sectional study

OBJECTIVE

To evaluate associations between exposure to three classes of medications (angiotensin converting enzyme inhibitors, calcium channel blockers, and corticosteroids) and self-reported depressive symptoms.

METHOD

The study utilised a cross-sectional study design in a sample of medical inpatients.

RESULTS

Associations between self-reported depressive symptoms and exposure to angiotensin converting enzyme inhibitors or calcium channel blockers were not observed. However, an association between self-reported depressive symptoms and corticosteroid exposure was identified. The association was strongest in subjects reporting a past history of depression or a family history of depression. The strength of the corticosteroid-depressive symptom association was comparable with that of associations observed for age, poverty and psychosocial stress.

CONCLUSIONS

Depressive symptoms among medical inpatients have a biopsychosocial etiology. Corticosteroid exposure may be a biological risk factor for depressive symptoms in this population.

Effects of agricultural work and other proxy-derived case-control data on Parkinson's disease risk estimates

This study examined the effects on Parkinson's disease risk estimates of exposure misclassification in proxy-derived data on agricultural work, pesticide use, rural living, well water drinking, head trauma, smoking, and family history of Parkinson's disease or essential tremor. The data were collected in 1989 as part of a population-based case-control study of Parkinson's disease in Calgary, Canada. Nondemented cases (n = 130) were selected from a case register of Calgary residents with neurologist-confirmed Parkinson's disease. For each case, two matched (sex and age +/- 2.5 years) community controls were selected by random digit dialing. Forty cases and 77 controls were randomly selected as index respondents. The cases, controls, and one proxy respondent (spouse or offspring) for each index respondent were interviewed using a structured questionnaire. The data were analyzed using conditional logistic regression. Incorporation of proxy-derived data for 30% of the cases or controls, or both, resulted in considerable misclassification of exposure for some variables and, in most cases, attenuation of the odds ratio. The results indicate that pooling dichotomously classified data derived in part from self- and proxy respondents may result in biased estimates of Parkinson's disease risk associated with agricultural, family history, and head trauma factors.

Incidence of hospital-acquired infections associated with caesarean section

A retrospective cohort study was conducted to determine the incidence of post-caesarean infections in a Canadian community teaching hospital using computer algorithms designed for the diagnosis of nosocomial infections. Inferential chart review was done on 1335 women delivered by lower-segment caesarean section (793 primary and 542 secondary) at the Calgary General Hospital between January 1985 and April 1988. The overall infection rates were 42.1 and 46.1% for women delivered by primary and secondary caesarean section, respectively. Incisional surgical wound infection accounted for the largest proportion of post-caesarean infections found. Women delivered by primary caesarean section had significantly higher rates of endometritis, deep surgical wound infection and bacteraemia than those delivered by secondary section. All types of post-caesarean infection, except asymptomatic bacteriuria, caused the duration of the post-partum hospital stay to be significantly increased.

Preventive antibiotic usage in traumatic thoracic injuries requiring closed tube thoracostomy

OBJECTIVE

To evaluate the safety and effectiveness of antibiotics in reducing the infectious complications following closed tube thoracostomy for isolated chest trauma.

DESIGN

Double-blind, randomized clinical trial.

SETTING

Medical school affiliated large urban teaching hospital and trauma center.

PATIENTS

One hundred nineteen of 159 patients over 18 years old presenting to the emergency department requiring closed tube thoracostomy for isolated chest injuries (113 penetrating, 6 blunt).

INTERVENTION

Patients received either placebo or 1 g cefonicid daily intravenously started at chest tube insertion and stopped within 24 h of removal.

MEASUREMENTS AND RESULTS

The development of wound infections, pneumonia (CDC criteria), or empyema; the incidence of adverse events; length of hospitalization. One nonspecific infection was seen in the cefonicid group (1.6 percent) and six respiratory tract infections (10.7 percent) in the placebo group (three empyema, one empyema with pneumonia, two pneumonia) (p = 0.0505; p = 0.0094 [excluding nonspecific infection]). No significant differences with antibiotic use were seen in the duration of chest tube use (p = 0.766), peak WBC counts (p = 0.108), lower peak temperatures (p = 0.063), or length of hospitalization (p = 0.165). Patients who developed infectious complications averaged approximately 8 days longer hospitalization than those without (p < 0.0001).

CONCLUSION

This study showed that patients receiving antibiotics had a significantly reduced rate of infection than did patients administered placebo. No significant adverse events were seen in either group.

Women and exercise participation: the mixed blessings of motherhood

Exercise participation, perceived barriers to exercise, and perceived benefits of exercise were analyzed in a large random sample of urban women ages 20-49 (N = 1,113). Although mothers and women without children perceived similar benefits of exercising, mothers were much less active than women without children. The differences were greatest for women under the age of 40. After age 40, the differences were smaller as a result of the decrease in exercise in women without children. The study also indicated that motherhood itself, rather than the number and ages of children, was a barrier to exercise participation. In general, mothers perceived more barriers to exercising than did women without children. These findings illustrate the differences in opportunities for mothers and women without children due to sociocultural circumstances and have implications for the planning of exercise promotion for mothers.

Reliability of environmental and occupational exposure data provided by surrogate respondents in a case-control study of Parkinson's disease

This study used data provided by 40 non-demented Parkinson's disease patients and 101 community controls, and by their 110 spouses and 31 adult children to assess the reliability of surrogate-provided rural environmental and occupational exposure information on the index subjects. The level of overall raw agreement between the index subjects and the spouse or adult child surrogates varied from 50.0 to 100.0% for the case-surrogate group and from 80.6 to 96.0% for the control-surrogate group. We did not detect significant differences in overall raw agreement between the case-surrogate and control-surrogate groups or between the spouse-surrogate and adult child-surrogate groups, for any of the variables studied. Considering all index subjects and their surrogates, the level of overall raw agreement was 80.3% for well water consumption, 82.3% for farm living, 85.8% for agricultural work, 87.1% for use of pesticides, 87.9% for field crop farming and 91.9% for use of fertilizers. However, the kappa estimates were lower, varying from 0.48 (SE = 0.20) for fertilizer use to 0.66 (SE = 0.11) for crop farming. The level of specific agreement was 52.2% for fertilizer use, 64.0% for pesticide use, 71.4% for agricultural work, 73.9% for crop farming, 80.9% for farm living, and 83.6% for well water consumption. The overall findings of this study support the use, if necessary, of spouses and adult children of index subjects as surrogate respondents in case-control studies of rural environment and occupational exposures and Parkinson's disease and, possibly, other neurologic diseases. Specific agreement seems to be a better index of reliability than overall agreement in studies where exposure is rare.

Childhood and adolescent passive smoking and the risk of female lung cancer

BACKGROUND

Few studies have reported the relationship between passive smoking (PS) in early life and the risk of lung cancer. This study was done to evaluate the risk of female lung cancer from PS, especially that during childhood and adolescence.

METHODS

Using household exposure to tobacco smoke as an estimate of PS, a 1:1 paired case-control study was conducted in Harbin, China. We interviewed 114 female primary lung cancer cases, aged 30-69 years, and their hospital-based controls. The controls were non-cancer patients, selected from the same hospital as the cases, and matched on age (+/- 5 years), residential area and smoking status over their lifetime. There were 59 pairs who ever smoked and 55 pairs who never smoked. Information on PS was collected by residence for each of the following periods: 0-6, 7-14, 15-22, 23-30 and 31-69 years.

RESULTS

Household PS significantly increases the risk of female lung cancer for those exposed at ages 22 or younger, who have ever smoked. The risk was also increased for those non-smoking pairs when exposed under the age of 15 years. Exposure to maternal smoking at ages 14 or younger increased the risk by about 170% (odds ratio, OR 2.7, 95% confidence interval [CI]: 1.49-4.88), but not to paternal smoking (OR 1.40, 95%CI: 0.92-2.50). The risk was highest for those exposed under the age of seven (OR 3.46, 95%CI: 1.80-6.65) and was also significant at ages 7-14 (OR 3.08, 95% CI: 1.62-5.57) and 15-22 (OR 3.10, 95%CI: 1.52-6.31) years. Under the age of 23 years, the OR increased with amount of PS (P < 0.001). Of note, the OR in all five exposure periods for non-smoking pairs were similar to those for all 114 pairs studied.

CONCLUSIONS

Household PS, particularly that during childhood, increases the risk of female lung cancer. The assessment of PS should be done by different periods of exposure.

Drug-induced depression. Incidence, avoidance and management

According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R), drug-induced depression may be classified as an Organic Mood Syndrome, Depressed Type. Unfortunately, the DSM-III-R diagnostic criteria are not sufficiently precise for application in research, and studies of drug-induced depression have rarely utilised these criteria. Research concerned with drug-induced depression is characterised by a number of methodological complications. These include differing definitions of depression, including depression defined as a symptom, a syndrome, or by diagnostic criteria for a specific mental disorder. In addition, patients undergoing pharmacological treatments for medical illnesses are typically exposed to considerable psychosocial stress due to the suffering and disability associated with illness. These psychosocial factors may in themselves precipitate episodes of depression. Due to these complicating factors, sophisticated study designs are required to confirm an aetiological role for medications as risk factors for depression. Unfortunately, adequate studies have rarely been conducted, and much of the literature consists of case reports and clinical observations. Consequently, clinicians are frequently required to make clinical judgements about the aetiology of patients' depressive symptoms in the absence of definitive scientific information about the role of drugs. Nevertheless, a knowledge of the relevant literature will assist clinicians in making reasoned judgements about the aetiology, prevention and management of these disorders.

Neuropsychiatric adverse drug reactions: passive reports to Health and Welfare Canada's adverse drug reaction database (1965-present)

OBJECTIVE

Since 1965, Health and Welfare Canada has operated an adverse drug reaction (ADR) program. The program accepts spontaneous reports of adverse drug reactions, and maintains an ADR database. The purpose of this article is to summarize the Psychiatric ADRs reported to this database since 1965. The nature of the information prohibits its use in the evaluation of epidemiological hypotheses about the etiology of drug-induced mental disorders. However, in an exploratory sense, the contents of the database may contribute to the development of epidemiological hypotheses about the etiology of drug-induced mental disorders. Of particular interest are areas of apparent contradiction between the contents of the database and the clinical literature.

METHODS

The database was searched for reports of ADRs to a group of drugs which have been frequently implicated in causing psychiatric toxicity. All reports characterized as "psychiatric disorders" were down-loaded from the database for the analysis (n = 1822). The reports were further classified into nine categories according to the type of psychiatric symptoms described.

RESULTS

There were several reports of hallucinations caused by methyldopa, and also several reports of benzodiazepine-induced hallucinations and encephalopathy. These reactions have not been described in the literature. Also, there were few reports of digoxin-induced organic depression, and an absence of reports of organic mania induced by H-2 blockers, despite descriptions of these sorts of reactions in the clinical literature.

CONCLUSIONS

Further research is needed to define the neuropsychiatric toxicity associated with medical drugs. Clinicians must continue to consider the potential role of medications in the etiology of psychiatric symptoms.

Exercising at work: barriers to women's participation

Only a minority of women in an urban random sample have the opportunity to exercise at work, and even fewer women use these opportunities. Lack of time and inconvenient times are the major reasons for not participating in exercise programs at work. Exercise programs at work are used by women who are already physically active, suggesting that workplace exercise programs do not serve the needs of women who may need exercise programs most. Multivariate analysis shows that age, having children, lack of energy, and lack of support are significant barriers to women's exercise participation at work. The results of this study suggest a leadership opportunity for on site occupational health nurses in addressing these barriers to workplace exercise.

Parkinson's disease: a test of the multifactorial etiologic hypothesis

We studied the relative etiologic importance upon the development of Parkinson's disease (PD) of occupational exposure to herbicides and other compounds, ionizing radiation exposure, family history of PD and essential tremor, smoking, and history of various viral and other medical conditions. We identified patients (n = 130) with neurologist-confirmed idiopathic PD through contacts with Calgary general hospitals, long-term care facilities, neurologists, the Movement Disorder Clinic, and the Parkinson's Society of Southern Alberta, and selected two matched (by sex and age +/- 2.5 years) community controls for each case by random digit dialing. We obtained lifetime work, chemical, radiation, medical, and smoking exposure histories and family histories of PD and essential tremor by personal interviews, and analyzed the data using conditional logistic regression for matched sets. After controlling for potential confounding and interaction between the exposure variables, using multivariate statistical methods, having a family history of PD was the strongest predictor of PD risk, followed by head trauma and then occupational herbicide use. Cases and controls did not differ in their previous exposures to smoking or ionizing radiation; family history of essential tremor; work-related contact with aluminum, carbon monoxide, cyanide, manganese, mercury, or mineral oils; or history of arteriosclerosis, chicken pox, encephalitis, hypertension, hypotension, measles, mumps, rubella, or Spanish flu. These results support the hypothesis of a multifactorial etiology for PD, probably involving genetic, environmental, trauma, and possibly other factors.

Can drugs cause depression? A review of the evidence

Drug-induced depressive disorders are classified in the DSM-III-R as organic mood syndrome, depressed type. The ability of certain drugs to cause depression is of clinical relevance because organic mood syndrome is a component of the differential diagnosis of depressive symptoms. Consequently, psychiatric textbooks often provide different lists of drugs thought to be capable of causing depression. Strong evidence supporting the existence of causal associations is often lacking. There is no specific drug for which there is definitive evidence of a causal association with depressive symptoms or depressive disorders. Nevertheless, for a number of drugs, the evidence is suggestive, although not conclusively, of a causal association. Despite this, rational decisions about the continuation or discontinuation of drugs can often be made. In this paper, the literature is reviewed and guidelines are suggested for the management of patients with depressive symptoms which may be related to drugs.

Women's social roles and their exercise participation

How women's social roles such as parenthood, marital status and employment status affect their exercise participation, is important for the rational planning of suitable and effective exercise programs for women in different social contexts. A secondary analysis of a large data-base of urban women aged 20-49 (n = 5939) was carried out to determine if social roles, their characteristics and their combinations were related to women's exercise participation. Parenthood and marital status were significantly related to whether women exercise, and among those exercising, all three roles were significantly related to the amount of exercise. Statistical modelling, including all three roles and their interactions, controlling for age and education, showed that with respect to whether women exercise, parenthood affected exercise participation most and that its effect was dependent on age. Of the role characteristics only the number of children and overall satisfaction with daily activities improved the prediction of exercising. With respect to how much women exercise, the effect of parenthood interacted with marital status. Married parents were least likely to exercise very much. Of the role characteristics only overall satisfaction with daily activities improved the prediction of the amount of exercise.

An assessment of the usefulness of demographic data provided by surrogate respondents in a case-control study of Parkinson's disease

This study, based upon data from 40 non-demented Parkinson's disease cases and 101 community controls, and similar data provided by either the spouse (n = 110) or an adult child (n = 31) of each index subject, attempted to assess the usefulness of various demographic data provided by the surrogate respondents for the index subjects. The data were collected by personal interview using a structured questionnaire specifically developed for this study. Ninety-one percent of the index subjects and their surrogates provided information on the annual family income and 98% provided other demographic information. The analysis was done by three groups: the case-surrogates, the control-surrogates and the combined index subject-surrogates, and within each group by the two types of surrogates for the index subjects: the spouse vs adult child. The overall percent agreement between the index subjects and their surrogates varied from moderate for annual family income (54.1%), to good for educational level (61.6%) and to excellent for ethnic origin (82.6%), for age +/- 1 year (97.9%) and for marital status (100.0%). No significant differences in agreement were found for any of these demographic variables either between the case-surrogate group and the control-surrogate group, or between the spouse surrogates and the child surrogates. These findings suggest that spouses and adult children can provide valid information and are equally reliable informants concerning the demographic characteristics of index subjects in a case-control study of Parkinson's disease and, possibly, of other diseases.

Women's exercise participation: the relevance of social roles compared to non-role-related determinants

The objectives of this study were 1) to determine the relationship between women's exercise participation and their social roles as well as characteristics of these roles, and 2) to determine the relative importance of social roles compared to non-role-related determinants (including social support, perceived barriers, interest in exercise, and perceived importance of exercise). A cross-sectional survey was done among 1,113 randomly selected urban women aged 20-49. Social roles did not emerge as a major risk factor for exercise participation. Statistical modelling indicated that whether women exercise was only related to role overload in the presence of the non-role-related determinants. For women exercising, parenthood as well as role overload were related to the amount of exercise in the presence of the non-role-related determinants. These findings have important implications for exercise promotion for women.

Hypertension and its correlates in the Hutterite community of Alberta

The purpose of this study was to determine the prevalence of hypertension and its correlates in the Hutterite population of Alberta. A total of 811 subjects from 38 Hutterite colonies participated in the survey. A self- and interviewer-administered questionnaire gathered information about past medical history, lifestyle habits, and family history. Blood pressure, blood cholesterol, 2 hour postprandial blood glucose and height and weight were also measured. The prevalence of diastolic blood pressure > or = 90 mm Hg was approximately twice that reported in other Canadian surveys: 60% and 30% for the males and females respectively. Half of the participants found to be hypertensive were unaware of their condition and of those aware, 76% were uncontrolled. There were significant correlations between diastolic blood pressure and Body Mass Index (BMI), cholesterol, age and glucose. This study supports the need for the development of culturally appropriate health promotion programs related to hypertension in this population.

Parkinson's disease and exposure to agricultural work and pesticide chemicals

This population-based case-control study of 130 Calgary residents with neurologist-confirmed idiopathic Parkinson's disease (PD) and 260 randomly selected age- and sex-matched community controls attempted to determine whether agricultural work or the occupational use of pesticide chemicals is associated with an increased risk for PD. We obtained by personal interviews lifetime occupational histories, including chemical exposure data, and analyzed the data using conditional logistic regression for matched sets. In the univariate analysis, a history of field crop farming, grain farming, herbicide use, or insecticide use resulted in a significantly increased crude estimate of the PD risk, and the data suggested a dose-response relation between the PD risk and the cumulative lifetime exposure to field crop farming and to grain farming. However, in the multivariate analysis, which controlled for potential confounding or interaction between the exposure variables, previous occupational herbicide use was consistently the only significant predictor of PD risk. These results support the hypothesis that the occupational use of herbicides is associated with an increased risk for PD.