Peripheral and central arterial haemodynamic interactions are early abnormalities in young male cigarette smokers.

BACKGROUND: smoking, result in endothelial dysfunction and this affects systemic and local haemodynamics. The aim was to assess interactions of the left ventricle and arterial system of smokers at baseline and after a physiological stimulus--the cold pressor test (CPT) which causes a sympathetically driven vasoconstriction that counteracts the normal endothelial dependent vasodilatation. MATERIALS AND METHODS: male smokers and controls were compared using applanation tonometry. Parameters included systolic and diastolic blood pressure, ejection duration, heart rate, aortic augmentation index (AAI), and sub-endocardial viability ratio (SEVR). The CPT was performed at 1 and 3 min following immersion of the hand in ice. RESULTS: smokers have abnormal baseline cardiac timing (heart rate and ejection duration), systolic and diastolic blood pressures which are due to increased peripheral wave reflection (AAI) and thus affect the SEVR. Following CPT, the pressure wave differential, dP/dt, was significantly increased in smokers compared to non-smokers who had a decrease at 1 min in ice. Mean systolic and diastolic pressure was significantly increased in both groups at 1 and 3 min as was end systolic pressure in non-smokers. CONCLUSIONS: baseline ventriculo-vascular dynamics, are abnormal as was the evoked response to CPT. The blunted blood pressure increase of smokers compared to controls following CPT, may represent altered nitric oxide production in the macro and microcirculation through differential upregulation of endothelial nitric oxide synthase (eNOS) and inducible NOS respectively. The potential for therapeutic intervention and prevention of ongoing endothelial injury, requires further investigation.     

Altered genetic response to beta-adrenergic receptor activation in late passage C6 glioma cells.

Previous studies have demonstrated variability in the phenotype of rat C6 glioma cells. In the present study, we compared morphology, growth rate, and beta-adrenergic regulation of gene expression in early (P39-47) and late (P55-90) passage C6 cells. Morphological changes were observed in five independently derived, late passage populations. In four of the five, the untreated cells were more polygonal than the fibroblast-like parental cells, and only a small fraction exhibited process outgrowth after dbcAMP treatment. Untreated cells from the fifth late passage population had longer cytoplasmic processes than parental cells and responded to dbcAMP with further process outgrowth. All late passage populations had shorter generation times than the parental cells. In early passage cells, treatment with the beta-adrenergic agonist, isoproterenol (IPR), resulted in an increase in c-fos mRNA and a decrease in c-jun mRNA (Gu-bits RM, Yu H: J Neurosci Res, 30:625-630, 1991). Both of these immediate early gene responses were irreversibly lost between P50 and P55. Additional differences in basal or IPR-induced mRNA levels were observed for beta-APP, GFAP, NGF, and PPE, but not for a number of other mRNAs. These results are discussed in relationship to previously described differences in the ability of early and late passage C6 cells to accumulate cAMP (Mallorga P, et al.: Biochim Biophys Acta 678:221-229, 1981).     

Custom cervical splint for use during head and neck surgery

A custom-made plaster cervical/occipital splint was described that was made to immobilize a patient with vertebral metastases during neck surgery. This is a single example of a problem solved by the cooperation between the head and neck surgeon and the maxillofacial prosthodontist.     

Systematic review of factors contributing to penicillin treatment failure in Streptococcus pyogenes pharyngitis.

OBJECTIVE: Review the evidence for various explanations for microbiologic treatment failure following use of penicillin in group A streptococcal (GAS) tonsillopharyngitis. DATA SOURCE: Systematic review of the literature based on Medline and EMBASE searches, and review of reference lists of included studies. RESULTS: The explanations for penicillin treatment failure in GAS tonsillopharyngitis include 1) carrier state, 2) lack of compliance, 3) recurrent exposure, 4) in vivo copathogenicity of beta-lactamase-producing normal pharyngeal flora, 5) in vivo bacterial coaggregation, 6) poor antibiotic penetration to tonsillopharyngeal tissue, 7) in vivo eradication of normal protective flora, 8) early initiation of antibiotic therapy resulting in suppression of an adequate host immune response, 9) intracellular localization of GAS, 10) GAS tolerance to penicillin, 11) contaminated toothbrushes or orthodontic appliances, and 12) transmission from the family pet. There is very little type I or II evidence to support any of the above-cited explanations for treatment failure in GAS tonsillopharyngitis; available studies are mostly observational (in patients) or laboratory-based without clinical confirmation. CONCLUSION: Multiple explanations have been offered by investigators to explain penicillin treatment failures in GAS tonsillopharyngitis, but the evidence base to support the proposed explanations is generally weak by current standards. Further research is needed to better understand the mechanism(s) of penicillin treatment failure in GAS tonsillopharyngitis.     

Small bowel rupture after blunt trauma: Computed tomographic signs and their sensitivity

The purpose of this study is to describe the characteristic computed tomographic (CT) signs of small bowel perforation after blunt abdominal trauma and to evaluate their sensitivity. Nineteen preoperative CT scans were obtained from 16 patients with surgically proven small bowel rupture secondary to blunt abdominal trauma. Only the CT findings described in the original CT reports were used. Eleven of 19 CT scans (58 %) had findings that were unequivocal for bowel rupture (i.e., extraluminal air and/or extravasation of oral contrast medium). Seven CT scans (37 %) had findings that were suggestive of severe small bowel injury (i.e., focal small bowel wall thickening and/or free peritoneal fluid without other accompanying organ injuries). In all, 95 % of cases of small bowel rupture had either pathognomonic or suggestive CT findings. One CT scan did not demonstrate small bowel wall thickening, although a hemoperitoneum was present. CT is a sensitive method for suggesting severe small bowel injury and rupture secondary to blunt abdominal trauma.     

Attitudes toward psychiatry among Irish final year medical students

This study investigated the attitudes of medical students towards psychiatry, both as a subject on the medical curriculum and as a career choice. Three separate questionnaires previously validated on medical student populations were administered prior to and immediately following an 8-week clinical training programme. The results indicate that the perception of psychiatry was positive prior to clerkship and became even more so on completion of training. On completion of the clerkship, there was a rise in the proportion of students who indicated that they might choose a career in psychiatry. Attitudes toward psychiatry correlated positively with the psychiatry examination results. Those that intended to specialise in psychiatry achieved significantly higher examination scores in the psychiatry examination.