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Biomedical subjects

J Lewis

Publications and source records attributed to J Lewis.

At least 505 records · Page 28Linked to original sources
PubMedDate not supplied

Hair cells without supporting cells: further studies in the ear of the zebrafish mind bomb mutant.

Each sensory hair cell in the ear is normally surrounded by supporting cells, which separate it from the next hair cell. In the mind bomb mutant, as a result of a failure of lateral inhibition, cells that would normally become supporting cells differentiate as hair cells instead, creating sensory patches that consist of hair cells only. This provides a unique opportunity to pinpoint the functions for which supporting cells are required in normal hair cell development. We find that hair cells in the mutant develop an essentially normal cytoskeleton, with a correctly structured hair bundle and well-defined planar polarity, and form apical junctional complexes with one another in standard epithelial fashion. They fail, however, to form a basal lamina or to adhere properly to the adjacent non-sensory epithelial cells, which overgrow them. The hair cells are eventually expelled from the ear epithelium into the underlying mesenchyme, losing their hair bundles in the process. It is not clear whether they undergo apoptosis: many cells staining strongly with the TUNEL procedure are seen but do not appear apoptotic by other criteria. Supporting cells, therefore, are needed to hold hair cells in the otic epithelium and, perhaps, to keep them alive, but are not needed for the construction of normal hair bundles or to give the hair bundles a predictable polarity. Moreover, supporting cells are not absolutely required as a source of materials for otoliths, which, though small and deformed, still develop in their absence.

Animals↗
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Design guidelines for interactive multimedia learning environments to promote social inclusion.

PURPOSE: There is a continuing need for guidelines to aid in the design of Interactive Multimedia Learning Environments (IMLE) to promote effective learning. The project introduced in this paper looks at an important subset of this problem, the design of interactive learning environments to promote social inclusion. METHOD: A consortium of six partners contributed toward defining learning material to develop a range of work based skills, including horticulture, IT and catering. These were then developed into IMLE prototypes. Formative evaluation of these prototypes then revealed a range of usability problems, which were grouped into generic types and frequency of occurrence. RESULTS: The most important and frequently occurring problems were used to distil a set of design guidelines for the development of effective IMLE. The results from this usability content analysis were also used to refine the initial prototypes to improve their usability and effectiveness. CONCLUSIONS: These guidelines, termed the Greenhat Design Guidelines, can be adopted for use by all multimedia developers aiming to promote the social inclusion of vulnerable or socially disadvantaged groups of people. The refined IMLE can be accessed via the Greenhat Server to improve the employment-related skills of socially excluded people.

Computer-Assisted Instruction↗
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Characteristics of state legislation governing medical care at mass gatherings.

UNLABELLED: Organized mass gathering medical care (MGMC) has existed in the United States for 30 years, but there is little evidence to support any standard of care or uniformity in its delivery. OBJECTIVE: To determine whether MGMC regulations exist within state EMS legislation and to describe the characteristics of any such regulations. METHODS: The authors conducted a cross-sectional survey of U.S. state EMS directors in fall 1998 to determine the prevalence of formal legislation governing MGMC. The lead author received copies of legislation from every state EMS office that indicated such legislation existed. RESULTS: Responses were obtained from all 50 state EMS offices and that of the District of Columbia (n = 51). Only six (12%) states provide regulatory guidance for MGMC. These regulations reside within departments of health in all six states and within the divisions of EMS in three of these six. Only one state requires physician oversight of a medical action plan and minimum staffing by EMS personnel, respectively. No state addresses early defibrillation capability or EMS scope of practice. There is no agreement on the definition of either a mass gathering or minimum resource deployment. Public health and hygiene practices at mass gatherings also lack uniformity. CONCLUSION: Few states regulate MGMC. Existing regulations are poorly developed and lack both standardized terminology and content.

Cross-Sectional Studies↗
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A comparison of rating scales for the alcohol-withdrawal syndrome.

This paper reviews the literature on the use of rating scales within the treatment of the alcohol-withdrawal syndrome. A computer-assisted literature search identified trials of therapy for and rating scales used in alcohol-withdrawal states. Eighteen rating scales were identified. There is a wide variation in symptom items included in these scales. Scales also vary in their length and ease of application. We conclude that it is important to use validated and reliable assessment scales in research if proper comparisons of treatments for the alcohol-withdrawal syndrome are to be made.

Anxiety↗
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Effect of cane use on tibial strain and strain rates.

The effect of cane ambulation on hip biomechanics has been well studied, but its effect on tibial strains and strain rates is not known. To test the hypothesis that cane use may lower tibial strain and strain rates during walking, percutaneous axial extensometers were mounted on the right medial cortex of the midtibial diaphysis in seven male volunteers. In vivo peak-to-peak axial tibial strains and strain rates were measured for ipsilateral and contralateral cane usage and compared with a no cane control. Cane-assisted ambulation was not found to significantly lower strain magnitudes; however, tibial strain rates were significantly lowered by both ipsilateral and contralateral cane usage. We conclude that either ipsilateral or contralateral cane usage may be beneficial when lowering tibial strain rate is desired, such as in the treatment of tibia stress fracture or osteoarthrosis of the knee.

Adult↗
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The effect of salicylate infusion on the alveolar epithelial membrane in the isolated perfused lung.

We observed two patients with aspirin (ASA) ingestion (blood levels of 87 and 56.5 mg/100 ml) who presented with noncardiogenic pulmonary edema (adult respiratory distress syndrome. To determine if ASA had a direct effect on the alveolar epithelial membrane, we established an in vitro isolated lung model and perfused it with platelet free plasma. T1/2 (in minutes), the time for 50% equilibration between the plasma and the saline filled lung, was determined before and after 500 mg salicylate infusion for various molecular weight dextrans. T1/2 decreased significantly (p less than 0.05) as follows: 3000 MW dextran, 2273 +/- 932 to 961 +/- 375; 40,000 MW dextran, 4059 +/- 1550 to 733 +/- 275; 70,000 MW dextran, 11,730 +/- 2750 to 7700 +/- 2230. Histamine levels in plasma and lung liquid did not change significantly with ASA infusion. We conclude that ASA directly increases alveolar epithelial permeability to dextrans less than 70,000 MW.

Aged↗
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Shared governance: is it a catalyst of change?

The purpose of this study is to evaluate a practical application of shared governance in a clinical health care setting. This investigation content analyzes monthly reports, personnel meeting minutes, individual preinterview and postinterview and satisfaction scores, a management assessment questionnaire, budget comparisons, and participant observations. Several identified shared governance applications include improved communication, conflict resolution, trust, team building, accountability, responsibility, quality care, and cost containment. This examination does support the value of the shared governance model as a catalyst of change. It indicates a need for more formalized committee structures, development of a peer review program and a staff action group to improve communications, and continued development of the shared governance model. However, this yearlong study strongly supports use of shared governance to increase job satisfaction, improve the budget, increase team building, and build job commitment.

Burn Units↗
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Chronic pain and the measurement of personality: do states influence traits?

STUDY DESIGN: This is a structured evidence-based review of all available studies on the effect of pain, (a state phenomenon) on the measurement of personality characteristics (a trait phenomenon). OBJECTIVES: To determine whether pain treatment changes trait scores. SUMMARY OF BACKGROUND DATA: Recent evidence from the psychiatric literature indicates that the measurement of personality characteristics (traits) can be affected or changed by the presence of state psychiatric disorders, for example, depression. At issue then is whether the measurement of chronic pain patients' (CPPs') trait characteristics is affected by the presence of pain, a state problem. METHODS: Computer and manual literature searches for pain studies that reported a prepain treatment and postpain treatment (test-retest) personality test or inventory score produced 35 such reports. These references were reviewed in detail and information relating to the above problem was abstracted and placed into tabular form. Each report was also categorized as to the type of study it represented according to the guidelines developed by the Agency of Health Care Policy and Research (AHCPR). In addition, a list of 15 quality criteria was utilized to measure the quality of each study. Each study was independently categorized for each criterion as positive (criterion filled), negative (criterion not filled), or not applicable, by two of the authors. Only studies having a quality score of 65% or greater were utilized to formulate the conclusions of this review. The strength and consistency of the evidence represented by the remaining studies were then categorized according to the AHCPR guidelines. Conclusions of this review were based on these results. RESULTS: Of the 35 reports, 32 had quality scores of 65% or greater. According to the AHCPR guidelines, there was a consistent finding that the Minnesota Multiphasic Personality Inventory (MMPI) scores changed (improved) with treatment. In reference to the Millon Behavioral Health Inventory, Locus of Control, the Symptom Checklist-90-Revised (SCL-90-R), trait anxiety, and personality disorders, there were not enough studies to draw conclusions about consistency. In reference to coping/self-efficacy inventories, somatization/illness behavior inventories, and personality questionnaire studies, there was a generally consistent finding that these tests changed (improved) with pain treatment. Overall, of the 32 reports, 92.3% demonstrated a change in trait scores (improvement) with pain treatment. This evidence was categorized as consistent. Finally, 100% of a subgroup of reports (N = 12) that had controlled for pain indicated that there was a relationship between a change in pain scores and a change in trait scores. CONCLUSIONS: Based on the above results, it was concluded that some trait tests and inventories may not be pain state independent. Therefore, caution is warranted in interpreting postpain development personality profiles as being indicative of the true prepain personality structure, if measured by these tests. Why trait scores may change with treatment, confounding test-retest issues, and whether trait tests actually measure what they allegedly measure are discussed.

Affective Symptoms↗
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Surgical management of a patient with cleidocranial dysplasia: a case report.

Cleidocranial dysplasia is associated with the formation of many supernumerary teeth which usually fail to erupt. In later life, cysts may form around the embedded teeth. The following report describes the management of such a case with a method which promotes satisfactory prosthodontic rehabilitation.

Calcium Phosphates↗
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Spontaneous occurrence of hepatic lipidosis in a group of laboratory cats.

Clinical signs consistent with hepatic lipidosis occurred in six obese adult laboratory cats, housed in a group cage, 6 to 7 weeks after changing their diet from a commercial to a purified diet. The affected cats lost 30 to 40% of their body weight in this time period. This rate of weight loss is compatible with little or no food intake. For treatment, 5 cats were tube-fed three or four times daily with a high-fat liquid diet supplemented with L-citrulline and choline. All cats tolerated the diet, which contained 35% protein on an energy basis. Substantial voluntary food intake resumed 12 to 16 days after initiating treatment. The sixth cat was euthanatized. These observations suggest that 6 to 7 weeks of anorexia, associated with 30 to 40% weight loss, can induce hepatic lipidosis in obese but otherwise healthy cats, and confirm that with appropriate management the prognosis for cats with hepatic lipidosis is favorable.

Animals↗
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Plasma taurine concentrations in normal dogs and in dogs with heart disease.

Plasma taurine concentrations were determined in 76 dogs with dilated cardiomyopathy (DCM), 28 dogs with acquired valvular disease (AVD), and 47 normal (control) dogs. The data were collected at 2 referral centers, The Animal Medical Center, New York, NY (AMC), and the University of California, Davis (UCD), and the studies were conducted independently. Different anticoagulants (sodium citrate at AMC and lithium heparin at UCD) were used to collect the plasma samples. Paired analysis of samples showed a significant difference in plasma taurine concentrations, depending on the anticoagulant used. Consequently, results from each clinic were analyzed separately. Plasma taurine concentrations were significantly higher in dogs with AVD (median, 133 nmol/mL; range, 25 to 229 nmol/mL) than in control dogs (median, 63 nmol/mL; range 44 to 224 nmol/mL) and dogs with DCM (median, 72 nmol/mL; range, 1 to 247 nmol/mL) at AMC (P < .001). The number of dogs with AVD at UCD was too small to draw meaningful conclusions. At UCD, the median plasma taurine concentration was 98 nmol/mL (range, 28-169 nmol/mL) in dogs with AVD, 75 nmol/mL (range, 0.1-184 nmol/mL) in dogs with DCM, and 88 nmol/mL (range 52-180 nmol/mL) in control dogs. There were no significant differences in plasma taurine concentrations between dogs with DCM and the control dogs at either hospital. Congestive heart failure and administration of cardiac medication had no significant effect on plasma taurine concentrations. Plasma taurine concentration was low (< 25 nmol/mL) in 17% (13/76) of the dogs with DCM. Seven of the 13 dogs with low plasma taurine concentrations were Cocker Spaniels or Golden Retrievers.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
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Coinfection with chlamydia and gonorrhoea among pregnant women and bacterial vaginosis.

The role of sexual transmission of microorganisms in bacterial vaginosis (BV) is controversial. If sexual intercourse were a risk factor for BV, then we would expect that women with BV would also be coinfected with other sexually transmitted diseases (STD). We investigated the prevalence of STD among pregnant women a low socio-economic status with bacterial vaginosis in Indonesia. Among these women, 23.3% had at least one STD (chlamydia, gonorrhoea, syphilis or trichomoniasis). Chlamydial infection was the most prevalent (19.5%), followed by trichomoniasis (3.8%), gonorrhoea (3.2%) and syphilis (0.4%). Compared to the rates of STD observed in a previous study of all pregnant women (with or without BV) in Indonesia, pregnant women with BV have more than a 2-fold increase in chlamydia (19.5% vs 8.2%) and a 6-fold increase in gonorrhoea (3.2% vs 0.5%). Because detection of BV by Gram stain is easy to perform and economical, detection of BV has potential as a prescreening marker for chlamydia and gonorrhoea among asymptomatic pregnant women of low socio-economic status in Indonesia. Further work is needed to evaluate the usefulness of BV as a prescreening marker for chlamydia and gonorrhoea.

Adult↗
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Positive regulatory gamma delta T cells in contact sensitivity: augmented responses by in vivo treatment with anti-gamma delta monoclonal antibody, or anti-V gamma 5 or V delta 4.

Contact sensitivity (CS) responses, induced by skin painting with reactive haptens like picryl chloride or oxazolone, are classical examples of in vivo immunity mediated by alpha beta T cells. Our previous studies showed that gamma delta T cells were required to assist the alpha beta CS-effector T cells in the successful adoptive cell transfer of CS responses. These spleen and lymph node-derived gamma delta+ CS-assisting regulatory cells were CD3+, CD4-CD8+, non-antigen-specific, and non-MHC-restricted, and preferentially expressed V gamma 5 and V delta 4 variable regions. In the current study we show that systemic treatment of mice in vivo with anti-gamma delta mAb, produced a similar positive influence on CS responses in two different systems: i.e. active sensitization, or adoptive cell transfer. In addition to augmented CS responses produced by treatment with pan anti-gamma delta TCR mAb, anti-gamma delta-V region mAb were examined, and augmentation of CS also was produced by anti-V gamma 5 and anti-V delta 4 mAb, the V regions determined previously to be preferentially expressed on gamma delta CS-assisting cells. We speculate that the positive influence of anti-gamma delta mAb was not caused by quantitative changes in gamma delta T cells, because FACS studies demonstrated a lack of in vivo depletion of peripheral blood and lymphoid gamma delta T cells, and also no depletion of epidermal dendritic gamma delta T cells (DETC), in mice treated with anti-gamma delta TCR mAb. Instead, our data favor the hypothesis that CS-assisting gamma delta T cells can be activated in vivo by anti-gamma delta TCR mAb interacting with their gamma delta TCR, at least with the short term protocols we employed, resulting in augmentation of CS responses perhaps by releasing positively-acting factors, such as certain cytokines.

Adoptive Transfer↗
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The role of nurse practitioners in primary care groups.

The author of this article is a newly elected member of the Hammersmith primary care group. She describes how she developed the role, learned new responsibilities and discovered opportunities to improve her work with patients.

Decision Making, Organizational↗
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HIV infection: immunobiology and laboratory diagnosis.

The immunobiology of human immunodeficiency virus (HIV) and the role of laboratory testing in the diagnosis and management of HIV infection are reviewed. HIV is one of a family of RNA viruses called retroviruses. HIV has three structural genes (one of which codes for reverse transcriptase) and six regulatory and maturation genes. Upon infection in humans, HIV commandeers the immune system by infecting and lysing T-helper lymphocytes. Since these cells are key to directing the body's immune defenses, the person becomes susceptible to a variety of opportunistic infections, neoplasias, and neurologic disorders. Laboratory tests for HIV are used for three purposes: screening of large populations (such blood donors), diagnosis of current or latent infection, and monitoring of disease progression. Diagnosis of HIV infection relies on HIV antibody detection, viral cultures, antigen detection, or polymerase chain reaction viral genome detection. Disease progression can be estimated using immunophenotyping with flow cytometry or using other immunologic markers. The immunologic variables associated with HIV infection disclose a growing spectrum of immune deficits. New tests for diagnosing and monitoring patients infected with HIV have been quickly incorporated into clinical practice.

Clinical Laboratory Techniques↗