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Biomedical subjects

T Goodman

Publications and source records attributed to T Goodman.

At least 19 recordsLinked to original sources

Roughness of a tilted anharmonic string at depinning.

We consider the discretized model of a driven string with an anharmonic elastic energy, in a two-dimensional random potential, as introduced by [Phys. Rev. Lett. 87, 187002 (2001)]]. Using finite size scaling, we numerically compute the roughness of the string in a uniform applied force at the critical depinning threshold. By considering a string with a net average tilt, we demonstrate that the anharmonic elastic energy crosses the model over to the quenched KPZ universality class, in agreement with recent theoretical predictions.

Journal Article↗

From current-driven to neoclassically driven tearing modes.

In the TCV tokamak, the m/n = 2/1 island is observed in low-density discharges with central electron-cyclotron current drive. The evolution of its width has two distinct growth phases, one of which can be linked to a "conventional" tearing mode driven unstable by the current profile and the other to a neoclassical tearing mode driven by a perturbation of the bootstrap current. The TCV results provide the first clear observation of such a destabilization mechanism and reconcile the theory of conventional and neoclassical tearing modes, which differ only in the dominant driving term.

Journal Article↗

Wilderness mortalities: a 13-year experience.

STUDY OBJECTIVE: To analyze the epidemiology of wilderness mortalities in a localized area with diverse terrain. METHODS: We conducted a retrospective review of the Pima County (Arizona) Sheriff's Office (PCSO) search and rescue logs and case reports, hospital records, and autopsy reports for all wilderness deaths from 1980 to 1992. The study group comprised all victims of injury or illness in Pima County wilderness who died during a 13-year period in a location remote enough so that standard ground-based emergency medical services units could not extract the body. RESULTS: One hundred fatalities occurred during the 13-year study period. There were 59 unintentional traumas, 18 suicides, 9 homicides, 12 medically related deaths, and 2 deaths of unknown causes. Toxicology tests performed on body fluids yielded positive findings for alcohol in a total of 50 (50%) cases and positive findings for drugs of abuse in 12 (12%) cases. It was estimated that alcohol was "a very probable" or "a probable" causative factor in 23 (40%) of the 59 unintentional trauma deaths, and in 1 (8.3%) of the 12 medically related deaths. Fifty-five (55%) deaths were witnessed events, with 45 (80%) of these victims reported as dying immediately or before arrival of search and rescue personnel. Ten (10%) victims received resuscitation in the field, and according to a review of hospital charts and autopsy reports, only 2 victims had a potentially survivable injury or illness. CONCLUSION: Many wilderness mortalities are related to incidents involving alcohol. Once the accident or injury has occurred, the majority of deaths are immediate, or at least before the arrival of medical personnel. Higher levels of medical care would not have improved the outcomes of those who did survive long enough to receive medical care. Therefore, primary efforts to reduce mortalities in the wilderness should be directed toward prevention, especially diminishing alcohol use in wilderness areas.

Adolescent↗

Steady-state fully noninductive current driven by electron cyclotron waves in a magnetically confined plasma

A steady-state, fully noninductive plasma current has been sustained for the first time in a tokamak using electron cyclotron current drive only. In this discharge, 123 kA of current have been sustained for the entire gyrotron pulse duration of 2 s. Careful distribution across the plasma minor radius of the power deposited from three 0. 5-MW gyrotrons was essential for reaching steady-state conditions. With central current drive, up to 153 kA of current have been fully replaced transiently for 100 ms. The noninductive scenario is confirmed by the ability to recharge the Ohmic transformer. The dependence of the current drive efficiency on the minor radius is also demonstrated.

Journal Article↗

Childhood mortality impact and costs of integrating vitamin A supplementation into immunization campaigns.

Country-specific activity and coverage data were used to estimate the childhood mortality impact (deaths averted) and costs of integrating vitamin A supplements into immunization campaigns conducted in 1998 and 1999. More than 94 million doses of vitamin A were administered in 41 countries in 1998, helping to avert nearly 169,000 deaths. During 1999, delivery of more than 97 million doses in 50 countries helped avert an estimated 242,000 deaths. The estimated incremental cost per death averted was US$72 (range: 36-142) in 1998 and US$64 (range: 32-126) in 1999. The estimated average total cost of providing supplementation per death averted was US$310 (range: 157-609) in 1998 and US$276 (range: 139-540) in 1999. Costs per death averted varied by campaign, depending on the number and proportion of the child population reached, number of doses received per child, and child mortality rates.

Child, Preschool↗

Polio as a platform: using national immunization days to deliver vitamin A supplements.

In 1988 the 41st World Health Assembly committed WHO to the goal of global eradication of poliomyelitis by 2000 "in ways which strengthen national immunization programmes and health infrastructure". The successful use of polio National Immunization Days (NIDs) to deliver vitamin A is an example of how polio eradication can serve as a platform to address other problems of child health. Importantly, this integration is helping to achieve the World Summit for Children goal of eliminating vitamin A deficiency by the year 2000. It is estimated that between 140 million and 250 million preschool children are at risk of subclinical vitamin A deficiency. In 1998 more than 60 million children at risk received vitamin A supplements during polio national immunization days (NIDs). While food fortification and dietary approaches are fundamental to combating vitamin A deficiency, the administration of vitamin A supplements during NIDs helps raise awareness, enhance technical capacity, improve assessment and establish a reporting system. Moreover, polio NIDs provide an entry point for the sustainable provision of vitamin A supplements with routine immunization services and demonstrate how immunization campaigns can be used for the delivery of other preventive health services.

Child↗

Beta 2 (CD18) mutations abolish ligand recognition by I domain integrins LFA-1 (alpha L beta 2, CD11a/CD18) and MAC-1 (alpha M beta 2, CD11b/CD18).

The "I" domains of the beta 2 (CD18) leukocyte integrins are implicated in ligand binding function. Moreover, rather than recognizing linear peptide sequences, this class of integrins generally recognizes multiple discontinuous sites on immunoglobulin superfamily adhesion receptors. A conserved cluster of oxygenated residues is involved in ligand recognition by beta 1 and beta 3 integrins. In the present study, we evaluated the role of this region in the I domain-containing beta 2 integrins. Recombinant alpha L beta 2 (LFA-1, CD11a/CD18) and alpha M beta 2 (MAC-1, CD11b/CD18) were expressed on COS cells, and function was assessed by adhesion to ICAM-1 or iC3b, respectively. Alanine substitution at position Asp134 or Ser136 in beta 2 produced a complete loss in the capacity of both alpha L beta 2 and alpha M beta 2 to support cell adhesion. In contrast, substitution at Asp128 or Ser138 resulted in loss of beta 2 surface expression when co-transfected with alpha L (CD11a) or alpha M (CD11b). These data provide the first evidence for involvement of the beta 2 subunit in ligand binding to I domain integrins.

Amino Acid Sequence↗

NSAID-induced gastrointestinal toxicity.

Recommendations that can be made to decrease the incidence of untoward NSAID-induced GI events include identification of the high-risk patient (Table 3). If it is important to treat these high-risk patients with NSAIDs, either the lowest possible dose of the NSAID, an alternative non-NSAID analgesic, or the nonacetylated salicylates should be used. If that is impossible and a nonsalicylate NSAID is required in the high-risk patient, one should treat concomitantly with tolerable doses of misoprostol and prescribe that the NSAID be taken with food. If the patient is intolerant of misoprostol, H2 antagonists or omeprazole should be considered to decrease the risk of developing an NSAID-induced duodenal ulcer. If patients are not in the defined high-risk groups, given the present costs of H2 antagonists, omeprazole, and misoprostol, there seems to be little justification in treating the patient prophylactically. However, if the patient develops progressive iron-deficiency anemia or occult fecal blood loss not due to an obvious malignancy, endoscopy can be recommended to determine the cause. If there is evidence of a significant NSAID-induced gastric or duodenal ulcer, the NSAID should be stopped and the ulcer treated. If that is impossible, the NSAID dosage should be as low as possible, and the ulcer treated. If an ulcer is found, either a biopsy for H. pylori or a serum assay for the organism should be obtained. Once the ulcer is healed through appropriate therapy, and if NSAIDs are still to be used, prophylaxis with misoprostol should be considered.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Inflammatory Agents, Non-Steroidal↗

Transcultural nursing. A personal and professional challenge.

The traveling nurse is a guest in the host country. It is wise to remember that we represent our country and our culture--we are the only Americans many of the locals have even seen. Be sure that foreigners see in us the very best example of American citizens. After work, there is often opportunity to spend time with the local people. They are usually extremely hospitable and anxious to share their culture. A nurse who can get involved with the local people has the chance to learn so much--different values, priorities, and customs. The culture may be rich in history and folklore. Their approach to health care can be fascinating--very different from our own, yet effective in many ways. There are often highly skilled craftsmen among the people are, producing wonderfully sophisticated things from nearly nothing. It is a source of real joy to bring back treasures from a culture one has come to know. In addition to the opportunity for clinical growth and the refinement of team skills, foreign travel provides an opportunity to grow personally. Adapting to new and more primitive surroundings requires patience and understanding. Interacting with people of a different culture also gives one the opportunity to evaluate ones own beliefs and attitudes. Sometimes it is surprising to realize that we are more snobbish or prejudiced than we believed; that revelation can be an opportunity for growth and change and a new source of pride in our country, our profession, and ourselves.

Developing Countries↗

Extrathymic selection of TCR gamma delta + T cells by class II major histocompatibility complex molecules.

The influence of MHC antigens on TCR gamma delta usage in CD8+ intraepithelial lymphocytes (IELs) was examined using a pan-reactive and V delta 4 region-specific MAb. While an average of 30% of IELs from the majority of mice of various MHC haplotypes were V delta 4+, a 2-fold or greater percentage of IELs from H-2k mice were V delta 4+. Analysis of IELs from F1 mice indicated that the increase in TCRs using V delta 4 was likely to be the result of positive selection. The V delta 4 usage patterns of IELs from recombinant inbred strains and from mice recombinant within H-2 revealed that the increase in V delta 4 usage mapped to H-2 and required I-E expression. Moreover, selection of TCRs using V delta 4 occurred in chimeric mice in the absence of a thymus. The results demonstrate an extrathymic selective mechanism for gamma delta TCRs of CD8+ IELs and suggest that these cells may exhibit MHC class II-restricted antigen recognition.

Animals↗

Intraepithelial lymphocytes. Anatomical site, not T cell receptor form, dictates phenotype and function.

The function and structure of the TCR proteins of intraepithelial lymphocytes (IEL) were examined using a panel of mAbs specific for TCR-gamma/delta. Three subsets of TCR-gamma/delta+ IEL could be detected with five mAbs, termed GL1-GL5. The mAbs were able to trigger lysis via crosslinking of the IEL TCR and all of the subsets were constitutively cytolytic. Immunoprecipitation of IEL TCR proteins revealed that the GL2 mAb reacted only with gamma, delta heterodimers containing high Mr delta chains, while the other mAbs precipitated all of the observed gamma and delta proteins. Two-color fluorescence analysis showed that the GL2+ subset was contained within the larger GL1+ subset. The GL3 and GL4 mAbs appear to be specific for all TCR-gamma/delta while GL2 was V delta 4 specific. Analysis of IEL for TCR-alpha/beta expression demonstrated that approximately 20% of B6 IEL were TCR-alpha/beta+. Interestingly, this population of IEL contained Thy-1- and CT1+ cells, indicating that the unique phenotype of IEL was not restricted to TCR-gamma/delta+ cells. Moreover, the TCR-alpha/beta+ IEL were also constitutively cytolytic, suggesting that the intestinal milieu was controlling the functional programming of IEL regardless of TCR type. The mAbs reported here as well as the ability to exploit the distinct phenotype of IEL should prove useful in determining the function of IEL and the TCR-gamma/delta.

Animals↗