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.     

Intraoperative measurement of javid shunt flow with transit-time ultrasound

Transit-time ultrasound methods were used to measure blood flow in 37 patients undergoing carotid endarterectomy. Internal carotid flow before (ICF^bef) and after (ICF^aft) endarterectomy was measured with a 6 mm perivascular probe, and Javid shunt flow (SF) was measured with a clamp-on probe. For the entire group ICF^bef averaged 117±67 ml/min and ICF^aft was 173±67 ml/min. Shunt flow averaged 123±51 ml/min. The differences between ICF^bet and ICF^aft and between SF and ICF^aft were significant (ANOVA,p<0.01) but the difference between ICF^bef and SF was not. The relationship between ICF^bef and SF appeared to define two groups of patients. Those in whom SF was greater than ICF^bef (SF > ICF^bef) had more stenosis evident on preoperative arteriograms (64.7%±14.55% maximum single diameter stenosis) and a greater average increase in ICF (151%±159%) than those with SF ICF^bef (43.3%±20.9% stenosis and 34%±54% increase in ICF), suggesting that the relationship between SF and ICF^bef defines groups with different hemodynamic responses. The similarity between SF and ICF^bef indicates that Javid shunt flow offers adequate protection from cerebral ischemia. A practical benefit of the shunt clamp-on flow probe is the ability afforded to recognize shunt occlusions.Presented at the Twelfth Annual Meeting of the Southern California Vascular Surgical Society, Coronado, Calif., September 17–19, 1993.     

Selective attenuation of neuropeptide-Y-mediated contractile responses in blood vessels from patients with diabetes mellitus

Vascular smooth muscle contractile responses to neuropeptide Y, ,ß-methyleneATP and noradrenaline were studied in circular segments of isolated vessels with intact endotheliumin vitro from 12 patients with diabetes mellitus type 2 (NIDDM) and 12 control subjects. The dilatory effect of acetylcholine was used to test the function of the endothelium. Subcutaneous arteries and veins (diameter 0.1–1.1 mm) were obtained during surgery. There was no difference in contractile responses to noradrenaline or ,ß-methyleneATP between diabetic and control vessels. The contractile response to neuropeptide Y, however, was markedly reduced in the diabetic group. The maximal contractile effect (46.0 ± 14.0%,p < 0.05) but not the sensitivity to neuropeptide Y was significantly less in diabetic veins compared to control (107.5 ± 19.6%). Thus, the attenuation of neuropeptide Y responses was present in humans as previously observed in alloxan-induced diabetes mellitus in rabbits. There was no difference in the dilator effect of acetylcholine between the diabetic and the control group in any of the vessel types, indicating that the difference in vascular reactivity to neuropeptide Y was not endothelium-dependent. In conclusion, the present study has shown that the postjunctional effects of neuropeptide Y, a co-transmitter of the peripheral sympathetic nervous system, is selectively attenuated in diabetes mellitus.     

Molecular genetic studies of early breast cancer evolution

Summary In the past few years there has been an explosion in the number of patients diagnosed with hyperplastic breast disease andin situ breast cancer. Based on epidemiological data, these morphologically defined lesions may be categorized as those with little malignant potential (e.g. typical hyperplasia or proliferative disease without atypia [PDWA]), those with significant malignant potential which may already be initiated (e.g. atypical ductal hyperplasia [ADH]), and early transformed lesions which are malignant but not yet invasive (e.g. ductal carcinomain situ [DCIS]). They may represent sequential evolutionary stages in the ontogeny of invasive breast cancer, with each morphologically defined stage resulting from accumulating genetic changes culminating in a transformed clonal lineage capable of invasion and metastasis. Using loss-of-heterozygosity (LOH) analysis, we are studying the genetic changes associated with these lesions in archival tissue samples. 50% (6/12) of the proliferative lesions (PDWA and ADH) and 80% of the DCIS shared their LOH patterns with more advanced lesions from the same breast, strongly supporting a precursor/product relationship between these lesions and the cancers they accompany.     

Medical Devices Made Into Weapons by Prisoners: An Unrecognized Risk

Study objective: The alteration of a knee immobilizer into a sharp weapon by a prisoner prompted us to survey neighboring penal institutions to determine the frequency of such events. Design: We mailed a nine-item survey to all detention facilities in Tennessee, Arkansas, and Mississippi. A second survey was sent to nonresponding institutions 6 weeks after the initial mailing. Setting: The Regional Medical Center at Memphis, the designated facility for evaluation and treatment of prisoners from the county jail and state penitentiary. Participants: Survey respondents included 25 state penitentiaries, 31 county jails, 1 state minimum-security facility, 1 state maximum-security facility, 1 work-release center, 1 county detention center for drunken-driving offenders, and 1 federal penitentiary. Results: Of the 81 institutions surveyed, 77% responded to one of the two mailings. Forty percent responded in the affirmative when asked whether stolen or unauthorized medical equipment from outside their institutions had been discovered among inmates. When respondents were questioned as to whether medical equipment, prescribed or not, had been used or altered in a criminal manner, 34% responded "yes." Medications and medical appliances were listed in the responses. Conclusion: A survey of 81 local and neighboring penal institutions in a three-state area revealed that the illicit use of medicine and medical devices by prisoners is a legitimate safety concern of prison personnel and health care workers when medical care for inmates must be sought outside the security of their institutions. The modification of medical equipment into weapons by incarcerated patients, although clearly recognized as a security and safety problem by police authorities, appears to be unappreciated by health care workers providing episodic care to inmates. [Hayden JW, Laney C, Kellermann AL: Medical devices made into weapons by prisoners: An unrecognized risk. Ann Emerg Med December 1995;26:739-742.]     

An expert system to teach troubleshooting of common problems associated with the automated anesthesia recordkeeper

Automated anesthesia recordkeepers have been used to monitor patients during surgery in up to 90% of cases at The Ohio State University. The record-keeping devices are complex and can be difficult to troubleshoot. The 1st-CLASS Fusion Program, an expert system shell-program, has been programmed to allow the resident or nurse anesthetist to solve the two most common types of problems associated with the recordkeeper: printer problems and patient monitor problems. Use of this program allows the resident or nurse anesthetist to troubleshoot the recordkeeper quickly and accurately and promotes in the user a sense of competence and control over the technology.     

Characterization of the epitope recognized by a mAb that reacts differentially with murine suppressor T cells

Although reliable antibodies are available that distinguishhuman suppressor T (T_s) cells from CTL and other T cells, feware available for murine T_s cells. We have developed a mAb (984D4.6.5)that, in the presence of complement, depletes alloantigen-specificT_s cells but not CTL. This antibody recognizes activated TT_scells but not their precursors. In these studies, flow cytometricanalysis demonstrates that 984D4.6.5 reacts with several T_scell hybridomas, cloned T_h cell lines and WEHI-3 (a myelomonocytictumor cell line). Reactivity was not detected with BW5147, T_hcell hybridomas, cloned T_h cells, CTL lines and hybridomas,B cell lines, thymocytes, splenocytes, bone marrow cells nora variety of tumor cells. Among 984D4.6.5 positive lines, expressionis heterogeneous and the number of cells expressing high levelsof the epitope is increased when the hybridomas are maintainedat a relatively high cell density. Neuriminidase and pronasedeplete the epitope recognized by mAb 984D4.6.5. Protein synthesisand glycosylation inhibitors also reduce expression of thisepitope. These observations suggest that the epitope recognizedby 984D4.6.5 is a carbohydrate linked to a polypeptide. Thisantibody was tested by ELISA for binding to a large panel ofcarbohydrates and glycollpids coupled to BSA. The only one thatbound 984D4.6.5 was LS tetrasaccharide c (NeuNAc2-6Galpß1-4GIcNAcß1-3GaIß1-4Glc),an O-linked carbohydrate. Comparative analysis shows that boththe sequence and the linkage of these sugars are essential tothe reactivity with the 984D4.6.5 antibody. This epitope isexpressed by a glycoprotein of-200 kDa, as shown by Westernblots. The identity of this glycoprotein remains to be determined,but indirect evidence suggests that it is not CD45.     

Screening of metal ion chelators against Leishmania donovani-infected Syrian hamsters

Leishmania donovani-infected Syrian hamsters were treated intraperitoneally with 0.23 mmoles/kg/day of EDTA, EGTA, HEEDTA and 100 mg/kg/day of Pentostam R. The control group received 0.1 ml of phosphate buffered saline. After 30 days of treatment, the animals were sacrificed. Of the Pentostam-treated animals, 5 out 6 had negative spleen cultures, while all the chelator and PBS-treated ones yielded parasites. While all the Pentostam-treated animals had negative bone marrow cultures, only 1 out of 6 HEEDTA-treated hamsters yielded parasites. Spleen, liver and bone marrow parasite- loads calculated from chelator-treated animals were consistently significantly higher than for Pentostam-treated animals. These results suggest that although metal ion chelators have some antileishmanial potential, their in vivo activity against L. donovani is low compared to Pentostam.