Nicotine abstinence syndrome precipitated by central but not peripheral hexamethonium.

A rodent model of nicotine dependence has been developed based on continuous subcutaneous (s.c.) infusion of nicotine tartrate. Nicotine abstinence syndrome was precipitated by s.c. injection of the nicotinic antagonist mecamylamine, which freely crosses the blood-brain barrier. In contrast, the nicotinic antagonist hexamethonium crosses the blood-brain barrier very poorly. This study determined whether central or peripheral administration of hexamethonium could precipitate nicotine abstinence. In the first experiment, 26 nicotine-dependent rats were injected s.c. with 0.5, 5 or 10 mg/kg hexamethonium dichloride or saline alone and observed for 20 min. Few abstinence signs were observed in any group; there was no significant drug effect. In the second experiment, 18 rats were cannulated in the third ventricle and rendered nicotine dependent. One week later, rats were injected through the cannula with 12 or 18 ng hexamethonium or saline alone and observed for 20 min. Both dose groups differed significantly from the saline-injected group, and there was a significant positive linear trend of signs as a function of dose. The high dose had no significant effect in 14 nondependent rats. We conclude that hexamethonium is much more potent by the central route, and there is a major central nervous system component in nicotine dependence.

Neuroendocrine responses to intravenous L-tryptophan in obsessive compulsive disorder.

We studied the neuroendocrine responses produced by intravenous L-tryptophan (TRP) in 16 untreated patients with obsessive compulsive disorder (OCD) and 16 matched healthy controls. The increase in plasma growth hormone seen following TRP was significantly greater in the OCD patients, while TRP-induced prolactin release did not differ from controls. Taken in conjunction with findings from other neuroendocrine studies the data suggest that some aspects of 5-HT1A neurotransmission may be increased in OCD. This increase may represent a compensatory change which promotes adaptation to stress in non-depressed OCD patients.

The functional status of patients. How can it be measured in physicians' offices?

Physicians wishing to maintain the functional capacity of their patients often need, but usually do not have, practical measures of function. The Dartmouth COOP, a primary care research network, developed nine pictorial Charts to efficiently measure patient function in busy office practice. Each Chart has a five-point scale, is illustrated, and can be self-administered or administered by office staff. The Charts are used to measure the patients' overall functional health just as Snellen Charts are used to measure vision. Studies to assess the Charts' reliability, validity, acceptability and clinical utility were conducted on over 2,000 patients in four diverse clinical settings. Results show that the Charts are both reliable and valid. One-hour test-retest intraclass correlations for elderly patients ranged from 0.78 to 0.98 and from 0.73 to 0.98 for low income patients. The average Pearson product-moment correlation between Charts and previously validated measures of function was 0.61 and the Charts were as capable of detecting the association between disease and functioning as were longer, standard measures. Most clinicians and patients report that the Charts are easy to use and provide a valuable tool to measure overall function in busy office practice. For the 25% of patients in which the Charts uncovered new information, changes in clinical management were initiated for 40% of them. We conclude that the COOP Charts are practical, reliable, valid, sensitive to the effects of disease and useful for quickly measuring patient function.

Physician variation in anticoagulating patients with atrial fibrillation. Dartmouth Primary Care COOP Project.

We investigated variations in the oral anticoagulant treatment of atrial fibrillation by physicians in three specialties: family physicians (or general practitioners), general internists, and cardiologists. Results showed general agreement in the anticoagulation decision regarding patients with either mitral valve disease or a history of chronic alcohol abuse, but substantial disagreement in other categories of patients. Estimations of the risk of embolization and risk of hemorrhage differed widely among all physicians, cardiologists generally rating the embolization risks lower than the other physicians. A physician's treatment decision was strongly related to the relative risk of embolism vs hemorrhage derived for each case. A relationship between physician specialty and treatment decision was also demonstrated, with cardiologists least likely, and family practitioners most likely, to institute anticoagulation in nonrheumatic patients with atrial fibrillation. The reason for this variation appears to be differences in the estimated risk of systemic embolism.

Ovarian cancer manifested as exertional hypotension due to obstruction of the inferior vena cava.

We have reported a case of inferior vena cava obstruction caused by recurrent ovarian carcinoma. This case is noteworthy first because it shows that physical findings in inferior vena cava obstruction may be minimal. Secondly, we believe ours is the first reported case of exertional hypotension caused by obstruction of the inferior vena cava. Finally, ovarian cancer has rarely been reported as a cause of inferior vena cava obstruction.

Do primary physicians actually manage their patients' fee-for-service care?

In what proportion of a patient's total health care is the primary physician involved? By means of calendar diaries and telephone interviews, 211 primary care patients from community practices of the Dartmouth Primary Care Cooperative Information Project were followed prospectively for one year. We found that a substantial proportion of care was managed (that is, either actually provided or coordinated in advance) by the patient's primary physician. Specifically, criteria for a primary physician's role in management were met by 75% of 1379 ambulatory visits to physicians, 33% of 786 visits to nonphysician health care providers, 81% of 26 nonemergency hospitalizations, and 78% of 2769 prescriptions. Primary physicians in these settings appear to function as case managers even when they are not participating in formal managed-care systems.

Psychological construing and meaningfulness in schizophrenia.

The ratings of schizophrenic and non-schizophrenic in-patients on a Semantic Differential were compared. Those schizophrenic patients who obtained low scores on a test of psychological construing (the Grid Test) made less use than other schizophrenics of extreme ratings on psychological scales on the Semantic Differential. The two groups of schizophrenics did not differ on their use of non-psychological scales. This indicates that the psychological scales are relatively meaningless to this group of subjects. The findings may explain the presentation of symptoms in schizophrenic patients.

The cooperative information project: Part 2: some initial clinical, quality assurance, and practice management studies.

Many of the obstacles inherent in the conduct of primary care research have been overcome by an experimental program in northern New England, the Primary Care Cooperative Information Project. This project uses a medical information network in 44 rural medical practices to carry out both clinical and management research. This paper describes the developmental problems encountered and the results of some initial clinical, quality assurance, and practice management studies conducted by the network and presents observations on its future research directions.

The Cooperative Information Project: Part 1: A sentinel practice network for service and research in primary care.

This is the first of two papers describing the Primary Care Cooperative Information Project (COOP Project), a program that integrates the interests of community physicians, medical school faculty, and health policymakers. This integration has been accomplished through the uniting of 44 rural medical practices in Maine, New Hampshire, and Vermont with faculty at Dartmouth Medical School in clinical research, quality assurance, practice management, and continuing medical education activities. This paper describes the structure, goals, and history of the COOP Project, together with the design, cost, and output of its computerized medical information system.