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Biomedical subjects

C S Allen

Publications and source records attributed to C S Allen.

8 recordsLinked to original sources
PubMed1998

A tetrahedral zinc(II) complex of tris(2-pyridylethyl)amine.

The zinc ion in the title complex, [N,N'-bis(2-pyridylethyl)-2-(2-pyridyl)ethylamine-kappa 4N]zinc(II) diperchlorate, [Zn(C21H24N4)](ClO4)2, displays a distorted tetrahedral configuration. The Zn-Npy distances range from 1.979 (5) to 1.999 (5) A, while the Zn-Namine distance is 2.028 (5) A. The Npy-Zn-Npy and Npy-Zn-Namine angles range from 111.9 (2) to 119.6 (2) degrees and from 102.3 (2) to 103.4 (2) degrees, respectively. This behavior contrasts with the five-coordinate geometry normally observed in tripodal ligands of similar structure, and can be ascribed to the presence of weakly-coordinating anions and the ligand-metal chelate-ring size.

Crystallography, X-Ray↗
PubMed1997

Phosphotyrosine phosphatase activity associated with c-Src in large multimeric complexes isolated from adrenal medullary chromaffin cells.

Chromaffin cells, which secrete catecholamines in response to acetylcholine, express high levels of the Src-family tyrosine kinases. These kinases contain protein-protein interaction domains which bind signal transduction proteins that participate in a variety of cellular processes. To determine if signalling proteins bind c-Src in chromaffin cells, we examined c-Src immunocomplexes for co-precipitating proteins. We discovered a phosphotyrosine phosphatase (PTPase; EC 3.1.3.48) activity which associates with specific subcellular pools of c-Src in vivo and which preferentially binds the SH2 (Src homology 2) domain of c-Src in vitro. Known PTPases were not identified by blotting of c-Src immunocomplexes with a panel of anti-PTPase antibodies, suggesting that the PTPase may be a novel family member. The c-Src-PTPase complex is enriched in the plasma membrane fraction and exists in several large complexes, as revealed by gel-filtration analysis. This PTPase activity is altered rapidly following stimulation by secretagogues, decreasing within 30 s and returning to basal levels by 60 s of stimulation. Both the subcellular localization and rapid activity changes suggest that the c-Src-associated PTPase may function in early signalling events emanating from the nicotinic acetylcholine receptor. In support of this is the co-precipitation of a PTPase activity with the nicotinic acetylcholine receptor and co-chromatography of this receptor with one or the c-Src-PTPase complexes.

Adrenal Medulla↗
PubMed1996

Narrowing the critical region for a rhabdoid tumor locus in 22q11.

Rhabdoid tumor is a rare malignant neoplasm of childhood that may occur in various locations, including the central nervous system and the kidney. Previous cytogenetic studies of primary rhabdoid tumors have demonstrated monosomy or deletion of chromosome 22 and have implicated the presence of a rhabdoid tumor suppressor gene that maps to 22q. We have employed fluorescence in situ hybridization to narrow the region for this locus in four rhabdoid tumor cell lines with translocations or deletions involving chromosome segment 22q11. The completion of a cosmid and yeast artificial chromosome contig spanning the immunoglobulin lambda gene locus to BCR has allowed us to map a critical region for a rhabdoid tumor gene to a 500 kb span of chromosome segment 22q11.

Chromosome Mapping↗
PubMed1995

Simplified method of sizing implants for orbital fracture repair.

PURPOSE/METHODS: Over the past six years, we have used ordinary radiographic film as a template for sizing alloplastic implants for orbital fracture repair in over 60 patients. The implants are made of such materials as titanium, Vitallium, and porous high-density polyethylene. Autoclaved 9.5 x 4.5-cm rectangles of radiographic film are easily trimmed, held by nontoothed forceps, inserted, and removed from the orbital cavity. RESULTS/CONCLUSIONS: We have found this simple and inexpensive technique to be superior to using aluminum templates that are supplied in commercially available plating sets.

Humans↗
PubMed1976

Blood parasites of Taiwan birds.

Blood films were examined from 1477 birds of Taiwan (193 species, 49 families). Haemoproteus Kruse was by far the commonest parasite, with Leucocytozoon Danilewski a not very close second. it is probable that some of the Haemoproteus infections represented new species, and 1 occurring in the Bamboo Partridge (Bambusicola thoracica sonorivox Gould) seemed characteristic enough to justify recognition as such; the name Haemoproteus bambusicolae sp. n. is proposed for this organism. Malaria was found in 77 birds, the greatest number of infections occurring in the Bamboo Partridge. Most of them were caused by Plasmodium juxtanucleare Versiani & Gomes, a pathogen of chickens, but a number were due to an undetermined species of Plasmodium. The Bamboo Partridge may be a reservoir host of the former. A few other identified species (P. rouxi Sergent & Sergent, P. hexamerium Huff, P. tenue Laveran & Mesnil) were seen, as well as some unidentified ones. Plasmodium tenue was seen in Garrulax canorus taewanus Swinhoe, a babbler: until now it was known only from the Pekin Robin (Leiothrix luteus Scopoli), also a babbler, in which we have found it extremely common. Sixty-four microfilarial infections were identified; they were especially frequent in the Button Quail (Turnix suscitator rostrata Swinhoe).

Animals↗
PubMedDate not supplied

Is Germany a model for managers?

Most American managers have a hard time making sense of Germany. The country has a fraction of the resources and less than one-third the population of the United States. Labor costs are substantially higher, paid vacations are at least three times as long, and strong unions are deeply involved at all levels of business, from the local plant to the corporate boardroom. Yet German companies manage to produce internationally competitive products in key manufacturing sectors, making Germany the greatest competitive threat to the United States after Japan. The seemingly paradoxical nature of the German economy typically evokes one of two diametrically opposed responses. The first is to celebrate the German economy as a "model" worth emulating--indeed, as the answer to declining U.S. competitiveness. The alternative, more skeptical response is to question Germany's staying power in a new, more competitive global economy. According to Kirsten Wever and Christopher Allen, the problem with both points of view is that they miss the forest for the trees. Observers are so preoccupied with praising--or blaming--individual components of the German economy that they fail to see the dynamic logic that ties these components together into a coherent system. In their review of recent research on the German business system, Wever and Allen argue that managers can learn an important lesson from Germany. In the global economy, competition isn't just between companies but between entire socioeconomic systems. Germany's ability to design a cohesive economic and social system that adapts continuously to changing requirements goes a long way toward explaining that country's competitive success.

Administrative Personnel↗