Mesenteric ischemia secondary to cocaine abuse: case reports and literature review

In summary, we report two cases of mesenteric ischemia following cocaine abuse in young women. In such cases it is always difficult to prove a direct causal relationship between the abuse of cocaine and mesenteric ischemia. Both our patients were relatively young (in their thirties) and did not have any history of atherosclerosis, and their urine toxicity screens were positive for the use of cocaine. Cocaine-related hospital visits are on the increase. Mesenteric ischemia should be considered in the differential diagnosis when evaluating a young patient with a history of cocaine abuse presenting with an acute abdomen.     

Human immunodeficiency virus type 1 and 2 envelope glycoproteins oligomerize through conserved sequences

Hetero-oligomerization between human immunodeficiency virus type 2 (HIV-2) envelope glycoprotein (Env) truncation mutants and epitope-tagged gp160 is dependent on the presence of gp41 transmembrane protein (TM) amino acids 552 to 589, a putative amphipathic alpha-helical sequence. HIV-2 Env truncation mutants containing this sequence were also able to form cross-type hetero-oligomers with HIV-1 Env. HIV-2/HIV-1 hetero-oligomerization was, however, more sensitive to disruption by mutagenesis or increased temperature. The conservation of the Env oligomerization function of the HIV-1 and HIV-2 alpha-helical sequences suggests that retroviral TM alpha-helical motifs may have a universal role in oligomerization.     

Health promotion, health protection, and preventive services

Health promotion, health protection, and preventive services reflect the 21 priority areas of Healthy People 2000. This article focuses on the cost-effectiveness of health promotion and the role that primary care physicians can play in this initiative.     

Concurrence of Graves'' disease and dysplastic cerebral blood vessels of the moyamoya variety

A recent observation that (+)-7-deaza-5'-noraristeromycin (1), as an L-like analogue of aristeromycin, possessed meaningful anti-trypanosomal properties has prompted a search of other 7-deazapurines with similar or improved anti-trypanosomal responses. In that direction a series of pyrazolo[3,4-d]pyrimidines (that is, 8-aza-7-deaza-5'-noraristeromycin derivatives, 2-11) related to 1 have been prepared. These derivatives were evaluated against bloodstream forms of Trypanosoma brucei brucei and Trypanosoma brucei rhodesiense grown in vitro. Of these compounds, the parent L-like derivative 2 was less potent (IC50 40-70 microM) than 1 (IC50 0.165-5.3 microM) whereas the D-like analogue 3 was inactive, which is the same trend observed previously with 7-deaza-5'-noraristeromycin. Interestingly, some moderate activity (IC50 12.2-16.8 microM) was seen in the D-like 4'-methyl derivative 7 while its L-like partner was inactive.     

Individual perceptions of stress by dentists

This paper is concerned with individual responses of four dental practitioners to stress. The subjects were chosen on the basis of age, sex, length of time in practice and whether or not they practised solo or in a group. Responses were measured against ten stressor variables that were previously found to have occurred commonly among dentists. From these responses stressor ratings of the four subjects were obtained and compared. These ratings, which seem to be idiosyncratic and unpredictable, reflect wide differences between the respondents. The findings suggest the possibility that these differences may be attributable to personality factors and differences in coping styles, and tend to support the hypothesis that stress is a unique, perceptual and experimental phenomenon.     

Cardiac morphology and left ventricular function in normotensive morbidly obese patients with and without congestive heart failure, and effect of weight loss

BACKGROUND: Prevention of hypothermia during abdominal surgery by insulating or heat-transferring methods has been the subject of numerous investigations. This study approaches the problem from a less discussed point of view, i.e. the effect of different surgical techniques on body temperature changes. METHODS: Body temperature was measured at 3 core and 6 skin points in 40 patients scheduled for cholecystectomy through open laparotomy or laparoscopy with pneumoperitoneum created and maintained with unwarmed carbon dioxide (CO2) insufflation. End-tidal CO2 was kept constant by adjustments of respiratory frequency. Anaesthesia, intravenous infusions, and draping of the patients were standardized. RESULTS: During the first 1 h of anaesthesia core temperatures decreased approximately by 0.7 degrees C and distal skin temperatures increased by 7 degrees C in both groups. At the end of surgery heat balance was similar in both groups. An increase of 2.5 1.min-1 in respiratory minute volume was needed to control end-tidal CO2 levels in the laparoscopy group during pneumoperitoneum which was maintained with a CO2 flow of 1.2 1.min-1 through the abdominal cavity. CONCLUSION: Laparoscopic technique with unwarmed carbon dioxide insufflation does not offer any advantage in terms of body temperature changes when compared to open surgery.     

Performance of an incoherent temporal-spreading OCDMA system with broadband light sources

The effect of the coherence time of light sources on the performance of an incoherent temporal-spreading optical-code-division multiple-access (OCDMA) system is studied in this paper. Broadband noise-like light sources, such as amplified spontaneous emission (ASE) sources, are used by the transmitters. Three different kinds of receiver structures are examined and compared. Results show the impact of the nonideal light sources on the system performances relative to the ideal case. Analysis shows that to achieve the best performance when the available optical bandwidth and data rate are fixed, there is an optimal range for the spreading code length.