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Biomedical subjects

S M Silver

Publications and source records attributed to S M Silver.

44 records · Page 3Linked to original sources

The in vitro synthesis of polypeptides for the platelet membrane glycoproteins IIb and IIIa.

The platelet membrane glycoproteins IIb (GpIIb) and GpIIIa form calcium-dependent heterodimers containing binding sites for fibrinogen, von Willebrand factor, and fibronectin. Although GpIIb and GpIIIa are distinct proteins, both GpIIb and GpIIIa are deficient in platelets from individuals with the recessive disorder Glanzmann's thrombasthenia. To gain a better understanding of the genetic basis for GpIIb and GpIIIa synthesis, we studied their synthesis by two human leukemia cell lines, HEL and K562. HEL cells contained complexes of GpIIb and GpIIIa, and K562 cells expressed GpIIIa, but not GpIIb, when stimulated with phorbol-12-myristate-13-acetate (PMA). RNA from HEL cells directed the in vitro synthesis of a 110,000-Mr precursor for GpIIb and a 92,000-Mr precursor for GpIIIa, which indicates that the synthesis of GpIIb and GpIIIa by HEL cells is directed by separate mRNAs. In contrast, RNA from PMA-stimulated K562 cells only directed the synthesis of a 92,000-Mr precursor for GpIIIa. The dissociation of GpIIb and GpIIIa synthesis in K562 cells suggests that GpIIb and GpIIIa may be the products of separate genes.

Blood Platelets↗

Factor-analytic support for DSM-III's post-traumatic stress disorder for Vietnam veterans.

Found substantial support for DSM-III's criteria for Post-Traumatic Stress using 405 Vietnam combat veterans. The results also suggested that some additional symptoms such as depression and anger be included as major signs, especially when one is dealing with Vietnam veterans. A comparison of symptom intensity was made between Vietnam veterans and non-Vietnam veterans. The results of the second study showed that Vietnam veterans attested to experiencing significantly greater intensities of DSM-III criteria behaviors than did non-Vietnam veterans. However, no significant differences were found for symptoms related to depression.

Combat Disorders↗

Experience in posology.

We used an organized problem-solving method to resolve posology problems in integrated curriculum. A thorough assessment of the extent of problems revealed the need for a mathematical foundation (perhaps due to decreased mathematics SAT scores) to achieve a high level of accuracy with posology in preparation for professional nursing practice. Early curriculum intervention allowed for higher learning level achievement and sufficient time for demonstration of acquired skills. The implementation of a self-learning module in conjunction with small group intervention appeared to have an impact on students' level of knowledge as well as the application of knowledge. This was evidenced by an increased mean score from pre- to post-testing on a multiple-choice examination. Ongoing evaluations will measure students' ability to actualize these concepts in their clinical practice. Perhaps now is the time to identify posology within integrated curricula and examine it as a basis for pharmacology to better prepare all students for this vital nursing responsibility.

Competency-Based Education↗

Loss on serial passage of rhesus monkey kidney cells of proteolytic activity required for Sendai virus activation.

Primary and secondary cultures of rhesus monkey kidney cells supported multiple-cycle replication of Sendai virus, but later passages lost this ability, and this was reflected in decreased plaque formation. Multiple-cycle replication also did not occur in LLC-MK2 cells, a continuous line of RMK cells. Failure of replication in serially passed cells was correlated with a decrease in proteolytic cleavage of a viral surface glycoprotein (Fo), and the ability of cells to support multiple-cycle replication and plaque formation could be restored by the addition of trypsin (0.3 microgram/ml) to the overlay medium. The use of wild-type virus, which requires trypsin, and protease activation mutants that require chymotrypsin or elastase for activation has provided evidence that the activating protease supplied by primary or secondary cells has trypsin-like activity. Inactive virus, with uncleaved Fo glycoprotein, absorbed to primary or secondary cells but did not infect them, even though such cells possess the enzyme that is capable of cleaving the Fo glycoprotein of virus synthesized in these cells. The inability of these cells to activate adsorbed virus indicates that the activating protease that they possess is inacessible to adsorbed virus, although it can act on the Fo glycoprotein during virus maturation in these cells. These data provide a biochemical explanation for the failure of later passages of a cell strain or a continuous cell line to support the replication of a paramyxovirus.

Animals↗

Pectoralis major myocutaneous flap: analysis of complications in a VA population.

Forty-five cases of head and neck reconstruction with pectoralis major myocutaneous flaps (PMMF) between 1985 and 1990 were analyzed retrospectively for complications. Thirty-two cases were done at the VA Medical Center and 13 at Albany Medical Center, a private university hospital. Total complication rate was 58%. In the VA population, complication rate was 59% as compared to 54% at the Albany Medical Center, which appears statistically not significant. It has been suggested that VA populations tend to have poorer health and socioeconomic status and are more likely to have higher complication rates. This conjecture is not borne out by this study. Complications are described and compared.

Fistula↗

A single session, group study of exposure and Eye Movement Desensitization and Reprocessing in treating Posttraumatic Stress Disorder among Vietnam War veterans: preliminary data.

This report summarizes data gathered thus far from an ongoing study. Two groups (total N = 12) of Vietnam War veterans diagnosed with Posttraumatic Stress Disorder (PTSD) received a single session of exposure or Eye Movement Desensitization and Reprocessing (EMDR) focusing on the veterans' most distressing war experience. Group assignment was random, treatment providers were blind to assessment data, and the pre- and posttreatment assessor was blind to treatment assignment. Both groups showed improvement on the Impact of Event Scale. EMDR treatment resulted in greater positive changes in within-session Subjective Units of Discomfort levels and on self-monitored severity of intrusive recollection. A trend toward decreased heart rate reactivity was observed in both groups. Results must be considered carefully due to the small number of subjects used in the study.

Analysis of Variance↗