Ethnic differences in the anatomical location of colorectal adenomatous polyps

The ratio of right- to left-sided colonic cancer is increasing, but data on the distribution of its usual precursor lesion, the colorectal adenoma, are contradictory. Therefore, we investigated the prevalence of right- and left-sided colorectal adenomatous polyps from January 1, 1970, to September 30, 1989, using the study design of "epidemiologic necropsy" and the autopsy files of The Johns Hopkins Hospital. Compared with the decade of the 1970's, the 1980's showed a slight decrease in the overall prevalence of right-sided adenomas (6.4 per 1,000, 95% confidence limits 4.7-8.8 vs. 5.1 per 1,000, 95% CL 3.6-6.5), but a marked decrease occurred in left-sided adenomas (11.8 per 1,000, 95% CL 9.3-14.3 vs. 6.7 per 1,000, 95% CL 4.8-8.6). As a result, the ratio of right-sided to left-sided adenomas increased from 0.55 in the 1970's to 0.77 in the 1980's. This increased ratio occurred in both sexes, although prevalences were lower in females, and in whites. Unexpectedly, blacks had a ratio of right-sided to left-sided adenomas greater than unity in both the 1970's and 1980's (1.19 vs. 1.79) due to a relatively high prevalence of right-sided adenomas (5.8 per 1,000, 95% CL 3.6-8.0 in 1970's; 5.8 per 1,000, 95% CL 3.3-8.3 in 1980's), but low prevalences of left-sided adenomas (4.9 per 1,000, 95% CL 3.0-6.8 in 1970's; 3.2 per 1,000, 95% CL 1.2-5.2 in 1980's). The overall adenoma prevalence in blacks was lower than in whites. We conclude that the right-sided predominance of colorectal adenomas in blacks suggests ethnic differences in the pathogenesis of colorectal adenomas. This observation may have important implications for secondary prevention of colorectal cancer.     

Application of engineered chimeric antibodies to the calibration of human antibody standards

Immunoassay quantitation of human antibody depends on the availability of reference sera that have been characterized in terms of their antibody content. This report expands upon the concept of "cross-calibration", using reference (dose-response) curves that have been generated with heterologous antibody as a means of calibrating prospective human antibody standards. Engineered human-mouse chimeric antibody, with a single human isotype and specificity, is used to construct the heterologous dose-response curve from which test antibody response data are interpolated. Transfer experiments are used to define and correct for the percentage of the total chimeric antibody that is immunoreactive and bound to solid phase antigen. The chimeric antibody-based calibration procedure is illustrated using H. influenzae Type B as the model antigen and an engineered chimeric IgG1 antibody that has a known mass per volume content and specificity for the hapten, 4-hydroxy-3-nitro-phenylacetyl (NP).     

The Effects of Helium-Neon Laser upon Regeneration of the Crushed Peroneal Nerve

This study was conducted to determine whether helium-neon laser would alter the regeneration process of a crushed nerve. If a biostimulating effect of laser irradiation was found, additional support would be provided for its use in the management of peripheral nerve injured patients. The peroneal nerve in both hind limbs of 12 female New Zealand White rabbits was crushed. The randomly selected limb received laser treatments daily for 15 days. Functional regeneration of the nerves was measured by nerve conduction amplitude performed prior to crush and every third treatment day thereafter. A split-plot ANOVA used to compare the difference in the amplitudes of the evoked motor potentials demonstrated a significant interaction (p < .01) for leg x day, indicating a significantly different pattern in measured amplitudes between treated and nontreated animal limbs over the course of the 15 days following lesion. J Orthop Sports Phys Ther 1992;15(5):209-214.     

Capture your market share. Healthcare's largest growth area requires strategic facilities planning

The outpatient consumer has more choices than ever before. Hospital's delivery systems must be optimized to remain competitive and survive financially.     

Changes in alpha-adrenoceptors during long-term treatment of rabbits with prazosin

Acute intravenous prazosin (0.05 mg/kg) caused marked falls in mean arterial pressure and postsynaptic alpha 1-adrenoceptor blockade in rabbits. During chronic oral dosing (3--21 days), tolerance developed and blood pressure returned to base-line pretreatment levels. This did not appear to be related to changes in plasma renin activity, body weight, prazosin kinetics, or alpha 2-adrenoceptor responsiveness. However, pressor responses to the alpha 1-adrenoceptor agonist phenylephrine and the mixed alpha 1/alpha 2-agonist noradrenaline increased during chronic prazosin therapy. Despite the development of apparent "tolerance," the response to bolus injections of prazosin was unchanged. No changes in the maximum number of prazosin binding sites or their dissociation constant were observed in the heart, spleen, forebrain, or hindbrain after 21 days treatment. It appears that although compensatory mechanisms develop during chronic prazosin treatment, they are not mediated by alterations in alpha 1-receptor binding but are related to changes in alpha 1-adrenoceptor responsiveness beyond the drug-receptor binding site.     

Electrolyte levels and net fluid and electrolyte movements in the gastrointestinal tract of weanling swine.

Electrolyte concentrations, osmolality and pH were determined in conventionally raised weanling swine fed a liquid diet. Incorporation of a dilution marker into the diet in combination with frequent feeding enabled estimations as to the sites of relative fluid and electrolyte absorption and secretion along the gastrointestinal tract. Unlike many other species the weanling pig depends largely on its large intestine for absorption of fluid and electrolytes with small changes in net fluid movement occurring along the jejunal and ileal segments. Additional observations included the absorption of water by the porcine stomach which increased dilution marker concentration by approximately twofold and the high osmolality values recorded in the small and large intestine. The implications of these observations are discussed with regard to pathogenesis of colibacillary diarrhea in the weanling pig.     

The cost of being perfect: perfectionism and suicide ideation in university students

OBJECTIVE: The aim of the study was to assess the relationship between dimensions of perfectionism and suicide ideation in a tertiary student population in Australia. METHOD: The methodology involved 405 students completing the General Health Questionnaire (GHQ-28) which includes a subset of questions which can be used to assess suicide ideation, and the Multidimensional Perfectionism Scale. RESULTS: The presence of suicide ideation was associated with higher scores on total perfectionism and two perfectionism dimensions, and total GHQ scores. There were significant differences between participants with high levels of perfectionism and participants with moderate to low levels of perfectionism on a measure of suicide ideation. Neither gender nor age were associated with differences in the scores, with results indicating high levels of perfectionism may indicate a vulnerability to suicide ideation. CONCLUSIONS: Perfectionism is a valued attribute in high-achieving populations. The question needs to be asked, however, at what cost? The findings indicate that high levels of perfectionism may be associated with an increased vulnerability to suicide ideation. Future research is needed to gain a better understanding of the complex interrelationship between personality and temperament, environmental factors and self-destructive behaviour.     

Domestic swine model for the assessment of chemical warfare agent-anesthetic interactions: some effects of sulfur mustard

A domestic swine model was developed to examine the interaction of chemical warfare agents with anesthetics and other drugs used during general anesthesia. Animals were fully instrumented, and clinically relevant physiological parameters were monitored throughout the experimental procedures. Exposure of animals under halothane anesthesia to the chemical warfare agent sulfur mustard (HD; 1 mg/kg intravenous) produced mild signs of systemic intoxication during the subsequent 5 hours. Induction doses of ketamine 1 hour after HD exposure resulted in periods of profound apnea, with continued respiratory distress for the next 2 hours. When animals were treated with HD 1 hour after the initiation of ketamine anesthesia, severe and persistent convulsion-like muscular activity was observed within 45 minutes of HD administration. This nonpurposeful activity was not ameliorated by diazepam but was dramatically reduced or eliminated by resumption of halothane anesthesia. Treatment of HD-intoxicated pigs with succinylcholine produced a prolonged apnea resulting in death. In these apparently mildly HD-intoxicated animals, the introduction of ketamine or succinylcholine can rapidly induce potentially life-threatening situations.