Minorities and AIDS: knowledge, attitudes, and misconceptions among black and Latino adolescents.

White adolescents in San Francisco high schools were more knowledgeable than Black adolescents about the cause, transmission, and prevention of AIDS (acquired immunodeficiency syndrome), and Black adolescents were more knowledgeable than their Latino peers. Black and Latino adolescents were approximately twice as likely as White adolescents to have misconceptions about the casual transmission of AIDS. Less knowledge about AIDS and prevalent misconceptions were associated with greater levels of perceived risk of contracting AIDS.     

Usefulness of frozen-section examination in resected mid-rectal cancer after preoperative radiation

The surgical treatment of rectal cancer of the middle third remains controversial. We treated 30 consecutive patients with preoperative radiotherapy (45 Gy) and low anterior resection. Anastomoses were performed with a stapler. Intraoperative frozen-section examination of the rectal margin established that it was free of tumor. Two patients died of surgery-related causes. Median follow-up of the remaining patients is now 52 months (range: 26 to 76 months). Eight patients had recurrences documented at surgical re-exploration: two local (pelvic) only, three local and distant, and two distant only. Local recurrences happened despite a frozen-section examination of the rectal margin negative for tumor. Six of the eight patients who experienced a recurrence have died of disease progression. Distant metastases were found in six other patients during follow-up; they subsequently died. Thus, our therapeutic approach was not associated with decreases in local or overall recurrences.     

Interpreting Post-Transplant Proteinuria in Patients with Proteinuria Pre-Transplant

Increasing numbers of patients receive kidney transplants before initiation of dialysis or shortly thereafter. Some of these patients have significant proteinuria pre-transplant making the interpretation of post-transplant proteinuria problematic. In this study, we evaluated post-transplant proteinuria in 115 patients who had urine protein measured within 3 months of transplant and assessed the association of proteinuria with allograft pathology. Proteinuria declined rapidly from 3650 +/- 3702 mg/day pre-transplant to 550 + 918 at 3 weeks (p < 0.0001) and continued to decline until 1 year post-transplant (472 +/- 1116, p < 0.0001 vs. 3 weeks). Proteinuria greater than 3000 mg/day was present in 48 patients (42%) pre-transplant, in 1 patient (1%) at 3 weeks and in 4 patients (4%) at 1 year. Surveillance graft biopsies were done at 1 year in 93% of patients. Proteinuria > or = 1500 mg/day and/or an absolute increase in proteinuria > 500 mg/day after 3 weeks post-transplant was associated with allograft glomerular pathology. In conclusion, pre-transplant proteinuria, even when high grade, declines rapidly after transplantation. Failure to decline or persistence of proteinuria greater than 1500 mg/day is indicative of allograft pathology.     

Lipoprotein(a) concentrations in Mexican Americans and non-Hispanic whites: the San Antonio Heart Study.

There is considerable evidence that lipoprotein(a) (Lp(a)) is a strong independent risk factor for coronary heart disease. Based on their risk factor profile, Mexican Americans have an increased risk of coronary heart disease, yet Mexican Americans have coronary heart disease mortality similar to or lower than that of non-Hispanic whites. The authors therefore attempted to determine whether Mexican Americans had decreased Lp(a) concentrations relative to non-Hispanic whites in the San Antonio Heart Study, a population-based study of diabetes and cardiovascular disease. Lp(a) concentrations (mg/dl) were significantly lower in Mexican Americans (n = 316) than in non-Hispanic whites (n = 242) (men: 10.4 vs. 16.3; women: 11.5 vs. 16.4). In addition, the proportion of persons with Lp(a) concentrations of > or = 30 mg/dl (the threshold at which increased risk of coronary heart disease is believed to occur) was significantly higher in non-Hispanic whites than in Mexican Americans (18.6% vs. 7.6%; Mantel-Haenszel odds ratio (adjusted for sex) = 2.79). Age, obesity, body fat distribution, cigarette smoking, alcohol consumption, and glucose and insulin concentrations were not significantly related to Lp(a) levels. Decreased Lp(a) concentrations may account in part for Mexican Americans' relative protection from coronary heart disease mortality.     

Transient right-to-left shunting through a patent foramen ovale secondary to unilateral diaphragmatic paralysis.

A 57 year old patient presented with unilateral diaphragmatic paralysis and severe hypoxaemia secondary to transient right-to-left interatrial shunting through a patent foramen ovale. The final diagnosis was made because of the initial detection of a shunt while the patient was breathing 100% oxygen.     

The effects of ischemia and ischemia-reperfusion on bacterial translocation, lipid peroxidation, and gut histology: studies on hemorrhagic shock in pigs.

The bacterial translocation hypothesis was tested in two studies (acute and subacute) in a porcine model of hemorrhagic shock. Male pigs (30-40 kg each) under general anesthesia had their femoral vein, femoral artery, and portal vein catheterized. After stabilization (1 hour) they were bled (40% of blood volume) over 30 minutes, then maintained in the hypotensive state (MAP = 30-40 mm Hg) for 2 hours, following which, according to randomization, they entered the control group or were resuscitated with whole blood (WB group) or with lactated Ringer's solution (LR group). In the acute study, the mesenteric efferent lymphatic was also cannulated, the control group was not resuscitated, and the animals remained under general anesthesia to the end of the experiment (8.5 hours), when gut tissue was obtained for histologic study and measurement of lipid peroxidation. In the subacute study, the control group was not bled, the animals were awakened at 6.5 hours, and the portal vein catheter remained in situ until 48 hours. In both studies, samples of portal blood were obtained for culture at regular intervals and on completion, samples from mesenteric lymph nodes (MLNs) for culture were taken in the acute study, and in the subacute study samples from MLNs, spleen, and liver were obtained. In the acute study significant bacterial translocation to the MLNs and portal blood did not occur among the controls (n = 3), the LR group (n = 5), and the WB group (n = 6). Significant evidence of lipid peroxidation was found in both the LR and WB groups. Histologic assessment showed no difference among the groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Digestive cancer in relation to diet in Spain.

Dietary factors are widely considered to be largely responsible for the different cancer incidences observed in different populations. In the present study we investigated the possible influence of dietary habits on the incidence of digestive cancer in the provinces of Spain. Data on specific mortality due to digestive cancer corresponding to the period 1975 to 1985 were obtained from the Instituto Nacional de Estadística. Nutritional data on the different provinces were in turn gathered from the Instituto de Nutrición del Consejo Superior de Investigaciones Científicas. The information was processed by the SPSS statistical software package. Lifestyle and socio-cultural factors are found to influence dietary risk factors in digestive cancer, particularly among women. The most significant correlations with the different cancers studied corresponded to total energy intake (responsible for 27.4% of variance), animal fats, and smoked fish and coffee. The latter is related to oral and esophageal cancer in particular (responsible for 15.4% of variance). Consumption of carrots and frozen vegetables is responsible for 6.5% of variance, vs. 4.4% of variance for alcoholic beverages, sugar, and Vitamin D. Differences are noted between both the sexes and their relationship to the different cancers studied.     

Who should have intravenous pyelograms before hysterectomy for benign disease?

A review of 493 cases was undertaken to identify which patients undergoing hysterectomy for benign disease had received a preoperative intravenous pyelogram (IVP), an abnormality identified by IVP, and intraoperative ureteral injuries. Intravenous pyelograms were performed on 299 patients (60.6%). Factors significantly associated with obtaining a preoperative IVP included an abdominal approach, uterine size of 12 weeks or greater, and uterine prolapse. Seventy-seven patients (27%) had an abnormal IVP; factors likely to be associated with abnormality included uterine size of 12 weeks or larger or an adnexal mass of 4 cm or larger. Endometriosis, pelvic inflammatory disease, pelvic relaxation, and previous intra-abdominal surgery were not associated with an increased prevalence of abnormal IVP findings. Two ureteral injuries were documented, one in the IVP group (0.3%) and one in the non-IVP group (0.5%). Clinical findings may be used to select for a preoperative IVP those patients who are likely to have abnormalities of importance to the pelvic surgeon.     

Passive electrical properties of motoneurons in aged cats following axotomy

The objective of this study was to determine whether the aging process influences the changes in the electrophysiological properties of motoneurons that occur as a consequence of axotomy. Accordingly, using intracellular recording and stimulating techniques, the basic electrical properties of control (unaxotomized) and axotomized spinal cord motoneurons of aged cats were determined. Compared with control motoneurons, axotomized motoneurons exhibited increases in input resistance (R_in), membrane time constant (τ_b) and the equalizing time constant (τ_c). While the electrotonic length (L) remained unchanged, axotomy induced a decrease in the total cell capacitance (C_cell. The post-axotomy reduction of C_cell indicates that the motoneuron surface area was reduced and the increased membrane time constant indicates that there was an increase in membrane resistivity (R_m). The post-axotomy conservation of L accompanied by an increase in R_m suggests that aged axotomized motoneurons undergo geometrical changes. Furthermore, calculations based on cable theory suggest that the diameter of the equivalent cylinder (d) decreased following axotomy, whereas the equivalent cylinder length (l) remained unaffected. It is concluded that axotomy produces significant alterations in the soma-dendritic portion of aged spinal motoneurons, as indicated by the changes found in their passive electrophysiological properties, and that the pattern of the response that occurs in axotomized motoneurons of adult cats is also present in axotomized motoneurons of aged animals.