Correlates and changes over time in drug and alcohol use within a barrio population

Extent and determinants of use of alcohol, marijuana, inhalants, and PCP were explored in a group of 339 Mexican American youths from the East Los Angeles Housing projects. Results from this study were compared to those from a similar survey carried out in the same area 2 years ago. Use of inhalants has declined markedly compared with prevalence reported in the previous report. However, use of alcohol and marijuana have increased across all age and sex cohorts. Prevalence of PCP use, explored for the first time in this report, was shown to be extremely high. Use of all drugs was generally predicted by age, sex, and number of peers reporting use. Self-concept factors, especially one's self-evaluation with respect to others, were also significant predictors to use of marijuana, inhalants, and PCP. However, alcohol use was not related to any self-concept factors. Language (Spanish-English) used both in the home and with peers was related to use of all substances studied. Limitations in the generalization of this study as a result of sampling problems are discussed.

Endoscopic detection of experimentally induced colonic neoplasms in guinea pigs (Cavia porcellus)

Colonoscopic examination was performed daily on 18 normal guinea pigs for 7 weeks and on 27 guinea pigs after 24-35 weeks of biweekly intrarectal instillation of the chemical carcinogen methylnitrosourea. Four normal guinea pigs died during the first 2 weeks of the study, two from colonic perforations and two from cecal bloating due to excessive air insufflation. The other 14 normal animals remained clinically healthy and had no gross abnormalities at the end of the 7-week study. Colonic tumors were detected by colonoscopy in five of seven treated guinea pigs that had grossly visible nodular tumors on the mucosal surface of surgically resected colonic tissue. In another treated guinea pig, a tumor was detected by colonoscopy which was not confirmed grossly. In an additional two treated guinea pigs, tumors were visualized by colonoscopy which could not be demonstrated in surgically resected tissue because of their inaccessible location within the pelvic canal. At necropsy, these latter two guinea pigs had nodular, mucosal growths in the pelvic portion of the colon as indicated by colonoscopy. Microscopically, an additional 13 cases of colonic neoplasms were identified in the resected colonic tissue without gross or colonoscopic evidence of intralumenal nodular growth.

Acute small animal preparation--suitable for fetal metabolic studies?

To determine the immediate effects of the "acute" experimental preparation, 11 near-term pregnant rabbits and 20 fetuses were studied. Blood samples were obtained from the maternal auricular artery, the fetal umbilical vein, and the fetal heart within 90 s of exposure of the uterus by laparotomy. Samples were assayed for pH, O2 and CO2 tension, O2 content, blood urea nitrogen, and plasma glucose. Results indicated that a pronounced fetal acidosis (primarily respiratory) had developed by the time samples were obtained. Further, fetal cardiac glucose levels were significantly elevated above umbilical vein concentrations in 7 of the 20 fetuses. In addition, maternal arterial O2 tension under light pentobarbital anesthesia was significantly less than that found in 35 unanesthetized does (52 vs. 79 Torr, P less than 0.01). All parameters measured varied over a wide range between animals. The results raise serious questions concerning the feasibility of performing and interpreting certain metabolic or cardiorespiratory studies in the acute small animal preparation.

Cerebrovascular accident and abnormal focus of hyperactivity revealed by dynamic study in scintiangioencephalography

A 75-year-old female was admitted to the hospital for suspicion of a cerebrovascular accident. An important focus of hyperactivity was noted during a dynamic study by scintiangioencephalography, consistent with a highly vascular tumor, but corresponding in fact to a focal transitory hyperfusion with accompanying intense neuronal activity.

Necessity for end colostomy with transection of the descending colon in guinea pigs

Surgical procedures for resection and transection of the descending colon in the guinea pig were studied. Wedge resection with removal of less than 1 cm diameter of tissue resulted in an 80% (8 of 10 guinea pigs) survival rate. Colonic transection with restorative anastomosis, either end-to-end or side-to-side, resulted in a 94% (35 of 37 guinea pigs) death rate due to colonic impaction proximal to the site of anastomosis. A modified procedure for ventral end colostomy resulted in a 79% (19 of 24 guinea pigs) survival rate. These results indicated that caution should be taken in surgical manipulations intended to treat or study diseases of the colon in the guinea pig.

[Tomodensitometry: localizing value in hypertension of adrenal origin (author's transl)]

Computarized axial tomography has shown the localization of adrenal lesions in four cases of hypertension of adrenal origin: two phaeochromocytomas, one primary hyperaldosteronism, one Cushing's syndrome. This method has the advantage of being neither invasive, nor time-consuming. Unfortunately, it cannot localize tumors smaller than two cm in diameter. It seems to be highly beneficial in phaeochromocytoma, where it can advantageously take the place of arteriography. It is less fruitful in primary hyperaldosteronism and in Cushing's syndrome because lesions are smaller.

A semiautomated procedure for rapid intrarectal instillation of fluids in the guinea pig

A penumatic operated semiautomatic system was developed for the intrarectal instillation of solutions in the guinea pig. The apparatus permitted one person to inject large numbers of animals at considerable savings in time compared to manually operated syringe techniques. The procedure was shown to be both rapid and safe for administering solutions intrarectally in the guinea pig.

Cultivation of Ureaplasma urealyticum in continuous culture

Continuous culture of Ureaplasma urealyticum is reported with a steady-state cell biomass of greater than 10(6) cells per ml. Thus, large cell numbers can be easily obtained; in addition, the system provides a powerful means for exploring what nutrients(s) limits the growth yield of this organism. Urea is shown not to be the growth-limiting nutrient in conventional media, although when provided in excess it appears to be completely hydrolyzed.

Double contrast examination of the colon

Simplified and readily feasible techniques of double contrast examination of the colon, before and after surgery, are presented. The examination is easy to perform, well tolerated by patients, and has a high diagnostic yield. Methods, indications, and uses are discussed. Illustrative case material is shown.

Ultrastructural study of binucleation in cells of the rat adrenal glomerular zone after a prolonged low-sodium diet

Binucleate cells have been found in the glomerular zone of the adrenal cortex in rats subjected to low-sodium diets. By considering the various possibilities for their production, both the findings of nuclei in process of constriction and nuclei identical in form, confronted and smaller in size than those of neighbour cells, are in agreement with an amitotic nuclear division as the possible mechanism for the formation of these cells.

[Scintigraphy of the choroid plexus (choroid plexography)]

An increase concentration of pertechnate in the choroid plexus was demonstrated in 21 patients pretreated with tin pyrophosphate injected intravenously 24 hours before the examination. Using this technique, the choroid plexus are seen quite clearly, giving indirectly a picture of the intracerebral ventricles. A dynamic study was carried out in 12 patients, 3 of whom had abnormalities of the cerebrospinal fluid circulation demonstrated by isotope cisternography. The results obtained were characterised by a typical diphasic curve with variations in the pathological cases.

Effect of a long-acting estrogen on the pituitary response to LH-releasing hormone (38582)

The effect of Quinestrol, an estrogenic substance of long-lasting activity, on the pituitary responsiveness to LH-RH was studied in ovariectomized rats. Quinestrol administered as a single 200 pg-dose significantly augmented the pituitary response to LH-RH 36 hr, 9 days, and although not significantly, also at 24 days after its oral administration. No effect could be detected 36 days after its administration. At a 20 pg-dose Quinestrol significantly augmented the pituitary response to LH-RH only at the 36 hr-period studied, this effect not being apparent in later time periods.

Hormonal steroids: effects on the vascular system

An increase in the incidence of thromboembolic disorders has been associated with oral contraceptive use, though the causative mechanisms remain unclear. Our studies indicate that the contraceptive steroids, irrespective of the intermediary metabolic processes involved, cause changes in the surface charge characteristics of the blood vessel wall and blood cells in the following cases: (i) in experiments using dogs, the hormonal steroids result in a greater reduction in the pore surface charge of veins than in arteries; (ii) in rats, the current induced mesenteric occlusion times are significantly lowered following administration of combined contraceptives steroids; (iii) in humans, the electrophoretic mobilities of erythrocytes and platelets from women taking Ovral and Demulen are lower than in controls, and (iv) there is no significant alteration of plasma coagulation times of women who are on injectable progestin therapy. Demulen and Ovral appear to result in a slight decrease in activated partial thromboplastin times compared to controls.