Postoperative morbidity of closely staged bilateral carotid endarterectomies: an intersurgical interval of 4 days or less.

The purpose of this study was to determine if there is increased morbidity and mortality with bilateral carotid endarterectomies (CEAs) done with an intersurgical period of less than 4 days compared to historical groups of unilateral CEAs, or those with a greater intersurgical delay. From January 1991 to July 1998, 1390 carotid endarterectomies were performed, of which 154 (11.1%) were closely staged bilateral CEAs. Seventy-seven patients (51 male, 26 female; mean age 72.5 years) underwent bilateral CEAs within 4 days or less. Immediate and 30-day postoperative morbidity, including neurologic deficits, cranial nerve deficits, and mortality, were documented. Although controversial, there is no increased morbidity or mortality with bilateral CEAs done with an intersurgical delay of less than 4 days, when compared to the unilateral CEA historical groups.

Male reproductive effects of solvent and fuel exposure during aircraft maintenance.

Few studies have addressed the effects of mixed, low-level exposures to complex mixtures on a man's reproductive potential. In this prospective study, each subject was evaluated before first exposure and at 15 and 30 weeks after exposures had begun. A total of 50 men working on aircraft maintenance at an Air Force installation were included in the study. In addition, eight unexposed men were concurrently sampled. Industrial hygiene (IH) sampling and expired breath samples were collected for jet fuel as measured by total napthas, benzene--a component of jet fuel, 1,1,1-trichloroethane, methyl ethyl ketone, xylenes, toluene, and methylene chloride. Sperm production, structure, and function (sperm concentration, sperm motion, viability, morphology, morphometrics, and stability of sperm chromatin) were evaluated. Exposures were low. All mean IH measures were below 6 ppm, which is less than 10% of the Occupational Safety and Health Administration standard for all chemicals except benzene. Sheet metal workers had the highest mean breath levels for both total solvents (24 ppb) and fuels (28.3 ppb). For most sperm measures, mean values remained in the normal range throughout the 30 weeks of exposure. When jobs were analyzed by exposure groups, some adverse changes were observed. The paint shop group had a significant decline in motility of 19.5% at 30 weeks. Internal dose measures, however, did not show a significant association with spermatogenic changes.

Comparison of internal dose measures of solvents in breath, blood and urine and genotoxic changes in aircraft maintenance personnel.

Solvents and fuels are in widespread use both in civilian and military populations. 1,1,1-trichloroethane (TCA), xylene, toluene, methyl ethyl ketone (MEK) and methylene chloride are found in a variety of compounds including degreasing agents, paints, coatings, pesticides and paint strippers. Toluene and xylene are also found in fuels, which are complex mixtures of hundreds of agents. The purpose of this investigation was twofold. The first was to determine the optimum medium to measure internal dose of solvents comparing blood, urine and breath. The second was to determine if low level exposures were associated with genotoxic changes after a short-term exposure of fifteen or thirty weeks. To accomplish the first goal a pilot study was initiated involving eight volunteers who worked in aircraft maintenance including sheet metal, painting and assembly mechanic jobs. Industrial hygiene measurements were evaluated over 30 working days. Breath, blood and a 24-hour urine sample were collected twice to compare internal dose parameters. To achieve the second goal, 58 newly hired subjects were monitored prior to exposure and over 30 weeks to determine if there were genotoxic changes as a result of solvent and/or fuel exposure as measured by sister chromatid exchanges (SCEs) and micronuclei (MN). Exposure groups included workers involved in sheet metal (fuel cell) activities, painting, fueling operations and flight line. Results of the pilot study demonstrated that industrial hygiene air samples and internal breath measures taken on the same day were highly correlated for measuring TCA (r = 0.93) and toluene (r = 0.90) but was not as well correlated for the other compounds. Breath measures were more sensitive for measuring low level exposure than were either analytes in blood or 24-hour urine samples; these latter two measures were usually below the limit of detection. A small but statistically significant increase in the frequency of SCEs occurred after 30 weeks of exposure for sheet metal workers (p = 0.003) and for painters (p = 0.05). The MN frequency in the sheet metal workers initially showed a significant increase by 15 weeks, but by 30 weeks had decreased. Chance occurrence of exposures to other occupational or non-occupational agents can not be eliminated as a cause of the genotoxic results since between 58 and 93 total analytes could be found in the breath of some aircraft maintenance personnel.

Genotoxic changes after low-level solvent and fuel exposure on aircraft maintenance personnel.

Individuals may be exposed to solvent mixtures and fuel either at work or home, through air, water and food contamination. Few studies have addressed the genotoxic effects of mixed, low-level exposure to fuel and solvent. This was an optimally designed study where each subject was sampled prior to exposure and after 15 and 30 weeks while exposed, in a repeated measures design with each subject serving as his own control. Fifty men aged between 18 and 50, working on aircraft equipment operation and maintenance at a military installation were included. Eight unexposed men were concurrently sampled. Sister-chromatid exchanges (SCE) and micronuclei (MN) frequency were measured in conjunction with air sampling and expired breath analysis for jet fuel (JP-4), 1,1,1-trichloroethane, methyl ethyl ketone, xylenes, toluene and methylene chloride. Exposure levels measured by industrial hygiene were very low (all means <6 p.p.m.), <10% of the OSHA standard. Expired breath levels were also low, <25 p.p.b. A small but statistically significant increase in the frequency of SCE occurred after 30 weeks of exposure for sheet metal workers (P = 0.003) and for painters (P = 0.05). The MN frequency in the sheet metal workers initially showed a statistically significant increase, but by 30 weeks had decreased. Cigarette smoking, alcohol and caffeine use were not associated with changes from baseline for either MN or SCE. Smokers, however, had significantly higher values of SCEs at baseline than did nonsmokers. In summary, these findings suggest that small increases in SCEs in particular, may serve as a sensitive biologic indicator of low level hydrocarbon exposure in as much as statistically significant changes occurred in the highest exposed groups but not in the low or no exposure groups. Chance occurrence or exposures to other occupational or non-occupational agents cannot be eliminated as a cause of the study findings.

Antinuclear antibodies in Utah coal miners.

Antinuclear antibodies (ANA) were detected using a mouse kidney substrate in 69 of 238 (29 percent) underground Utah coal miners at a titer of 1:16. At titers of 1:4 and higher, 52 percent were positive. The majority had a speckled pattern and were not directed against any previously characterized antigens. Fifteen of 28 with high titer ANA had reduced complement. The ANA was more apt to be present in those with coal workers' pneumoconiosis (CWP), and as ANA titer increased, the percentage with CWP increased. The ANA increased with both age and coal mine dust exposure. It is hypothesized that ANA and CWP both result from long-term dust exposure, but that there is insufficient evidence to implicate ANA in the pathogenesis of CWP.

An electrophysiological analysis of the anticonvulsant action of cannabidiol on limbic seizures in conscious rats.

The effects of cannabidiol (CBD) on electrically evoked kindled seizures were studied in conscious, unrestrained rats with chronically implanted cortical and limbic electrodes, and the results were compared with those of delta 9-tetrahydrocannabinol (delta 9-THC), phenytoin (PHT), and ethosuximide (ESM). All drugs were anticonvulsant, but there were marked differences in their effects on afterdischarge (AD) threshold, duration, and amplitude. CBD, like PHT and delta 9-THC, elevated the AD threshold; in contrast, ESM decreased the threshold but suppressed AD spread. CBD, however, also resembled ESM inasmuch as both drugs decreased AD duration and amplitude. Electrophysiologically, the antiseizure effects of CBD were a combination of those of PHT and ESM. The combination of effects may account for the observation that CBD was the most efficacious of the drugs tested against limbic ADs and convulsions. Other properties of CBD were also noted: For example, compared with delta 9-THC, it is a much more selective anticonvulsant vis-à-vis motor toxicity. CBD also lacks the CNS excitatory effects produced by delta 9-THC, PHT, and ESM. These characteristics, combined with its apparently unique set of electrophysiological properties, support the suggestion that CBD has therapeutic potential as an antiepileptic.

The influence of cannabidiol and delta 9-tetrahydrocannabinol on cobalt epilepsy in rats.

The mechanisms of the anticonvulsant activity of cannabidiol (CBD) and the central excitation of delta 9-tetrahydrocannabinol (delta 9-THC) were investigated electrophysiologically with conscious, unrestrained cobalt epileptic rats. The well-known antiepileptics, trimethadione (TMO), ethosuximide (ESM), and phenytoin (PHT), were included as reference drugs. Direct measurements were made of spontaneously firing, epileptic potentials from a primary focus on the parietal cortex and convulsions were monitored visually. ESM and TMO decreased the frequency of focal potentials, but PHT and CBD exerted no such effect. Although CBD did not suppress the focal abnormality, it did abolish jaw and limb clonus; in contrast, delta 9-THC markedly increased the frequency of focal potentials, evoked generalized bursts of polyspikes, and produced frank convlusions. 11-OH-delta 9-THC, the major metabolite of delta 9-THC, displayed only one of the excitatory properties of the parent compound: production of bursts of polyspikes. In contrast to delta 9-THC and its 11-OH metabolite, CBD, even in very high doses, did not induce any excitatory effects or convulsions. The present study provides the first evidence that CBD exerts anticonvulsant activity against the motor manifestations of a focal epilepsy, and that the mechanism of the effect may involve a depression of seizure generation or spread in the CNS.

Giving and getting surgery in Utah: an urban-rural comparison.

Using the Blue Cross/Blue Shield and Medicare records for 1 year in Utah, we examined the pattern of surgical performance for 15 selected procedures. Only 60% of those identifying themselves as general surgeons had their specialty boards. General practitioners performed 24% of the procedures. Urban general practitioners performed proportionately more surgery than did their rural counterparts. There was no clear pattern of difference in fees or length of stay by specialty or board certification status. For most procedures studied, at least a third of the rural patients had their operations in urban hospitals. In only 3% of the cases did an urban physician operate in a rural hospital. The pattern of surgery for rural and urban residents was strikingly similar.

Effects of adding a Medex on practice costs and productivity.

Archival data on ten rural practices employing a Medex and on ten matched controls were compared to determine changes in the volume of patients seen and changes in the practice finances before and after the employment of a Medex. There were no significant differences in the changes in patient volume; however, the practices that employed a Medex showed an increase in revenue and in net profit per physician. On the average, the net profit increased approximately $11,000 (22%) for the physicians with Medex, compared with $9,000 (21%) for the control physicians.

The mentally ill in nursing homes. New back wards in the community.

The reduction in state hospital populations in the last two decades is most often attributed to psychotropic medication and community mental health centers. The role the proprietary nursing home has played in this reduction has not been adequately studied. Using data routinely collected for Medicaid utilization review, we studied characteristics of psychiatric nursing home patients in Utah. One third of the nursing home patients had a psychiatric diagnosis; more than half of this group were classified as psychotic. Most psychotic patients were significantly younger than their nonpsychiatric counterparts. Nonpsychiatric patients received a higher mean number of psychoactive drugs than did psychiatric or mentally retarded patients. Over time, all groups of patients showed an increase in prescribed psychoactive medication and a decrease in activity. The consequence of this pattern of care raise serious questions about our current reliance on nursing homes for the care of the psychiatric patient.

Issues underlying prevalence of "doctor-shopping" behavior.

Data were collected on all persons within a sample of upper-and lower-income households who had seen physicians for illness episodes within a year prior to the interview. Forty-eight percent of upper-and 37 percent of lower-income families in the sample had changed doctors because of dissatisfaction with some aspect of the care. Factors related to tendency to shop for doctors in both upper-and lower-income groups were a lack of confidence in doctors' competence, unwillingness of doctors to spend time talking with patients, hostile feelings toward doctors, high cost of services, inconvenience of location and hours, and unfavorable attitudes toward doctors' personal qualities. Hypochondriasis was related to doctorshopping in the upper-income group. Results of this investigation suggest that patients may be becoming more discriminating in their choice of physicians.

Adding a Medex to the medical mix: an evaluation.

Three classes of Medex were followed during their preceptorship training and subsequent employment to assess the impact of adding such physician assistants on 13 private practices. The data suggest that the Medex are readily incorporated into the practice, seeing a similar spectrum of patients and generally functioning as a semicolleague. Although the Medex was almost universally a contributing addition to the practice, increasing patient volume, the specific effects varied with the setting.

Medex and their physician preceptors. Quality of care.

Studies of selected indicators of the process of care provided by a Medex and by a physician preceptor in seven rural practices suggest that the Medex is more likely to use appropriate laboratory tests and less likely to use inappropriate treatments. When outcomes of care were determined in 13 practices with a Medex and a preceptor, the patients seen by the Medex tended to fare about as well as those seen by a physician (71% versus 74%, respectively) in regaining their usual functional status. The addition of a Medex to a rural practice may thus produce both direct and indirected benefits.

The use of utilization review records as a source of data on nursing home care.

Data form the Utah nursing home Utilization Review Program, 1970-73, provide a description of the population of nursing home patients in Utah and changes over time in patient medication and measures of activity. These data are analyzed according to type of care in home: personal, intermediate, or comprehensive. The collection of data in utilization review programs can help to evaluate the quality of care as well as appropriateness of placement, provided the information collected is designed with these ends in mind.

A controlled trial of multiphasic screening.

A clinical controlled trial was designed to determine the impact of Automated Multiphasic Health Testing on morbidity and attitudes. Three strata comprising 574 families (lower-income group enrolled in health maintenance organization, lower-income not enrolled in such a project, and a middle-income group employed by a utility company) were interviewed to obtain information on utilization, morbidity, health status, and attitudes. Sixty percent of adults in each stratum were then screened. All families were interviewed again one year later. The only significant difference found between screened and non-screened subjects was an increase in nights hospitalized for screened subjects. Physicians were interviewed to determine what abnormalities were found and what treatment was required for project and privately referred patients of these physicians. Previously unknown abnormalities prompted retesting for confirmation in only 28 per cent of the cases and even less often led to treatment.

Medical care as a commodity: an exploration of the shipping behavior of patients.

A 10% household sample of high- and low-income census tracts was interviewed to assess the extent of doctor shopping. In 632 households studied, 53% of high socioeconomic status and 51% of low socioeconomic status families had shopped for or changed doctors of their own volition. During the previous year, 4% of each socioeconomic group had consulted more than one doctor without referral for the same episode of illness. Shoppers could be distinguished from non-shoppers--shoppers were younger, were better informed about medical specialties, were less self-reliant, more hypochondriacal, expressed less hostility towarn physicians, and had less positive attitudes toward the medical care system. The differences between shoppers and non-shoppers were generally similar for both high and low socioeconomic status groups. In addition, 52% of the families studied had been forced to change doctors because of circumstances beyond their control, i.e., the patient moved or the doctor moved, retired, or died.

The influence of delta9-tetrahydrocannabinol, cannabinol and cannabidiol on tissue oxygen consumption.

The mechanism of the hypothermia produced in mice by the naturally occurring cannabinoids, delta9-tetrahydrocannabinol, cannabinol, and cannabidiol, was investigated by evaluating the direct effect of these drugs on the oxygen consumption of tissue homogenates and isolated mitochondria. The tissues studied were brain, liver, skeletal muscle, and heart; the mitochondrial preparations were limited to brain and skeletal muscle. The in-vitro studies included a description of the influence of various cannabinoid vehicles containing Tween 80, ethanol, Pluronic F68, and albumin on the oxygen consumption of tissue preparations. Of these vehicles, only albumin was without effect on all tissues. The other vehicles produced diverse responses, including some that were qualitatively different; the data illustrate that the influence of each vehicle on oxygen consumption must be defined for each tissue employed. In spite of the different vehicle effects, delta9-tetrahydrocannabinol generally reduced oxygen consumption of all tissue preparations; however, the vehicles were capable of modifying the dose-effect relationship. The results of all three drugs prepared in Pluronic F68 on brain and skeletal muscle indicated that the cannabinoids generally cause a dose-related depression of oxygen consumption. The findings demonstrate that the cannabinoids can directly decrease oxidative metabolism of tissue and isolated mitochondria and that a marked response occurs in the concentration range of 1 X 10(-5) to 1 X 10(-4) M. Because these concentrations can exist in tissues following the in-vivo administration of delta9-tetrahydrocannabinol, the results suggest that the depressant effect of the cannabinoids on metabolic rate may contribute to the mechanism of the hypothermia produced by the drugs.