The Impact of Community Diversity and Consolidated Inequality on Dropping Out of High School

Abstract: Data from the National Education Longitudinal Study were combined with census data at the zip code level to examine the impact of neighborhood racial and ethnic diversity and consolidated inequality, in addition to individual, family, and school factors, on the likelihood of dropping out of high school. Results indicate that while the effects for diversity and consolidated inequality did not support the stated hypotheses, main effects for family risk and prior academic achievement were significant and in the stated direction. Also, when controlling for individual, family, school, and neighborhood characteristics, African Americans were less likely than White students to drop out of school. Implications for contextual effects research and educational outcomes are discussed.     

Mechanism for homologous downregulation of thromboxane A2 receptors in cultured human chronic myelogenous leukemia (K562) cells.

Desensitization of the biologic response to thromboxane A2 (TXA2) mimetics has been observed ex vivo in human platelets due to TXA2 receptor uncoupling and downregulation. To define more clearly the mechanisms of homologous TXA2 receptor downregulation, the effects of the TXA2 mimetics U44069 ([15S)-hydroxy-9,11- (epoxymethano) prostadienoic acid] and I-BOP ([1S-(1 alpha 2 beta(5Z),3 alpha(1E,3S),4 alpha))-7-[3-(3-hydroxy-4- (p-iodophenoxy)-1-butenyl)-7-oxabicyclo[2.2.1]heptan-2-yl]-5 -heptenoic acid) on receptor-mediated calcium fluxes and on ligand binding to TXA2 receptors were studied in the K562 cultured human leukemic cell line which possesses many platelet characteristics. Incubation with U44069 resulted in a time-dependent decrease in the amplitude of TXA2 receptor-mediated intracellular free calcium transients. Under the same conditions, binding of [125I] BOP demonstrated a concurrent loss of K562 plasma membrane binding sites to approximately one-third the original number. The loss of [125I]BOP binding was prevented by coincubation with the TXA2 antagonist SQ29548 ([1S-1 alpha,2 beta (5Z), 3 beta,4 alpha]-7- (3-[2-[phenylamino)-carbonyl) hydrazino) methyl)-7-oxabicyclo-(2.2.1)- heptan-2-yl)-5-heptenoic acid]) and was reversed upon removal of U44069 from the culture medium. SQ29548 alone had no affect on receptor density or affinity. Loss of surface receptors was demonstrated to be mediated by agonist-occupied receptor internalization which was inhibited by incubation at 4 degrees C and did not occur with antagonist occupation. The results indicate that homologous downregulation of TXA2 receptors in K562 cells occurs by agonist-mediated active internalization of plasma membrane TXA2 receptors.     

Pharmacotherapy of psychiatric emergencies

The psychiatric emergency service has become a major provider of psychiatric care over the past decade. Concomitant with this growth has been an emphasis on pharmacological treatment. While rapid tranquilization is the best known and most frequently used intervention, a growing diagnostic awareness has led to a variety of other chemotherapeutic approaches. The current reviews of pharmacologic intervention in the psychiatric emergency service do not detail the variability of treatment approaches or examine alternative treatment approaches. The goal of this article is to critically review current pharmacologic treatments and address areas in which there is no consensus in treatment approach. From this review the authors suggest guidelines for pharmacotherapy of psychiatric emergencies. The authors discuss rapid tranquilization, the treatment of alcohol and drug intoxication and withdrawal, and anxiety disorders.     

Retrorenal colon: implications for percutaneous diskectomy

It has been recommended that computed tomography (CT) with the patient prone be performed in every patient undergoing percutaneous diskectomy; this would enable detection of a retrorenal location of the colon, which could interfere with the percutaneous procedure. In this evaluation of 346 prone CT studies, only one patient (0.29%) was found to have retrorenal or retropsoas bowel that would have been perforated at diskectomy. Because of this extremely low prevalence, the performance of prone CT in every patient undergoing percutaneous lumbar diskectomy is not believed to be necessary.     

Kryokonservierung und Transplantation von Ovarialgewebe

There are relatively few effective clinical options for preserving female fertility, particularly following aggressive chemotherapy and/or radiotherapy treatment protocols. This document reviews scientific background, current technology, clinical results, and potential future applications of ovarian tissue cryopreservation and transplantation. The technology is investigational although rapidly evolving, and the list of appropriate indications may be expanded in the future. Germany stays abreast of these rapid worldwide developments by having founded the first German network of experts for fertility preservation in patients undergoing chemotherapy and/or radiotherapy.     

The immunofluorescence-microscopical evidence of insulin and glucagon in transplantated isolated Langerhans' islets in diabetic rats and dogs (author's transl)]

With the histochemical immunofluorescence technique were demonstrated the insulin and glucagon in the transplantated isolated Langerhans' islets in the liver at diabetic rats and dogs. Further on were tested the diabetic metabolic level with aid of clinico-chemical methods during the period of investigation (blood glucose, serum insulin, glucose tolerance test). It was found that after transplantation, 1 year by the rats and more than 8 weeks by the dogs, is existing a normoglycemic level. In the transplanted islets were seen a good immunofluorescence of insulin in the B cells and the glucagon in the A cells in all investigated stages.     

Proctolin immunoreactive neurons in the human brain stem

Using the peroxidase-antiperoxidase (PAP) technique it could be established that a variety of nerve cells of human Pons and Medulla oblongata contain proctolin-like material. These neurons belong to the Nuc. olivaris caudalis, Nuc. originis n. hypoglossi, Nuc. raphes dorsalis and the Nuc. ambiguus. Furthermore, proctolin immunoreactive peptide was found to be contained in certain fiber systems (Lemniscus medialis and fiber tracts near the Raphe).     

Serotype O157:H7 Escherichia coli from bovine and meat sources.

Serotype O157:H7 Escherichia coli strains from several different bovine and meat (beef) sources were studied to determine the diversity of their virulence properties and to compare their plasmid characteristics. Eighteen strains from cattle feces, 2 from water buffalo feces, 3 from beef samples, and 2 from feces of human hemolytic uremic syndrome cases were examined. All of these strains hybridized with the CVD419 DNA probe which identifies serotype O157:H7 and many other serotypes of verocytotoxin-producing E. coli. Of 15 bovine strains that hybridized with two verocytotoxin DNA probes, 8 hybridized with both verocytotoxin 1 (VT1) and VT2 probes, 5 hybridized with only the VT2 probe, and 2 hybridized with only the VT1 probe. This distribution was similar to that reported for O157:H7 E. coli isolated from humans. All three beef isolates hybridized with both VT1 and VT2 probes. All strains that hybridized with the VT probes were positive in the verocytotoxin assay, and all probe-negative strains were negative in the assay. All the strains possessed large plasmids with molecular sizes ranging from 53 to 64 MDa. Fifteen of the 20 cattle and water buffalo strains had one or more additional small plasmids. Restriction patterns resulting from HindIII, SmaI, and BamHI digestions of the large plasmids were used to compare all possible pairs of five different single plasmid-bearing strains from different countries (Egypt, England, and the United States). The restriction patterns of these strains were distinct, and the mean coefficients of similarity for these comparisons ranged from 71 to 91%, indicating a moderate degree of genetic diversity. This diversity and the presence of multiple plasmids in many bovine and human O157:H7 strains reinforce the usefulness of plasmid analysis in future studies. Only four of the 20 bovine strains and 1 of the 3 beef strains possessed the capability for adherence to HEp-2 and Intestine 407 cells in the presence of mannose, indicating that in vitro expression of localized adherence is not a universal property of O157:H7 strains of bovine origin.     

Long-term ST database: A reference for the development and evaluation of automated ischaemia detectors and for the study of the dynamics of myocardial ischaemia

The long-term ST database is the result of a multinational research effort. The goal was to develop a challenging and realistic research resource for development and evaluation of automated systems to detect transient ST segment changes in electrocardiograms and for supporting basic research into the mechanisms and dynamics of transient myocardial ischaemia. Twenty-four hour ambulatory ECG records were selected from routine clinical practice settings in the USA and Europe, between 1994 and 2000, on the basic of occurrence of ischaemic and non-ischaemic ST segment changes. Human expert annotators used newly developed annotation protocols and a specially developed interactive graphic editor tool (Semia) that supported paperless editing of annotations and facilitated international co-operation via the Internet. The database contains 86 two- and three-channel 24h annotated ambulatory records from 80 patients and is stored on DVD-ROMs. The database annotation files contain ST segment annotations of transient ischaemic (1155) and heart-rate related ST episodes and annotations of non-ischaemic ST segment events related to postural changes and conduction abnormalities. The database is intended to complement the European Society of Cardiology ST-T database and the MIT-BIH and AHA arrhythmia databases. It provides a comprehensive representation of ‘real-world’ data, with numerous examples of transient ischaemic and non-ischaemic ST segment changes, arrhythmias, conduction abnormalities, axis shifts, noise and artifacts.