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Biomedical subjects

T Hill

Publications and source records attributed to T Hill.

At least 19 recordsLinked to original sources
PubMed2005

Antileukemic effect of daclizumab in CD25 high-expressing leukemias and impact of tumor burden on antibody dosing.

Humanized anti-CD25 antibody, daclizumab, was applied in a pilot study of 10 patients with CD25(+) leukemias and pharmacokinetic/pharmacodynamic properties were characterized. Two widely held concepts - tumor sink accelerating pharmacokinetics and higher antigen expression correlating with target cell clearance - were supported by this first systematic evaluation of these questions with actual human clinical data. A flexi-dosing regimen was validated for maintaining target drug levels in vivo with a wide range of tumor burdens. Daclizumab induced clearance of peripheral leukemic cells when highly positive for CD25, but durable responses were not obtained. If daclizumab will have a role in antileukemic therapy, it may be in minimal disease settings or as a component of a combination regimen, but only when CD25 expression is high.

Adult↗
PubMed2005

Reorganization of small Co particles on Al2O3 surfaces monitored by ferromagnetic resonance.

Changes of the magnetic properties of ferromagnetic Co particles deposited on the radical31 x radical31R +/- 9 degrees reconstructed alpha-Al2O3(0001) as well as on a thin alumina film grown on a NiAl(110) substrate were investigated as a function of thermal annealing. On the thin film changes of the magnetic response were found above 500 K which correlates with changes in the particle size distribution. Annealing to 870 K leads to a permeation of the metal though the oxide film which causes significant changes in the ferromagnetic resonance response. On the alpha-Al2O3 single crystal sintering of particles requires temperatures above 600 K being about 100 K higher as compared to the thin alumina film. For large clusters intraparticle redistribution takes place already below 600 K a phenomenon not observed for the small clusters. In addition, a significant dependence of the measured g values from the substrate as well as the thermal treatment is found which can be understood in terms of the structural properties of the systems.

Journal Article↗
PubMed2005

Morphological differences between Saturn's ultraviolet aurorae and those of Earth and Jupiter.

It has often been stated that Saturn's magnetosphere and aurorae are intermediate between those of Earth, where the dominant processes are solar wind driven, and those of Jupiter, where processes are driven by a large source of internal plasma. But this view is based on information about Saturn that is far inferior to what is now available. Here we report ultraviolet images of Saturn, which, when combined with simultaneous Cassini measurements of the solar wind and Saturn kilometric radio emission, demonstrate that its aurorae differ morphologically from those of both Earth and Jupiter. Saturn's auroral emissions vary slowly; some features appear in partial corotation whereas others are fixed to the solar wind direction; the auroral oval shifts quickly in latitude; and the aurora is often not centred on the magnetic pole nor closed on itself. In response to a large increase in solar wind dynamic pressure Saturn's aurora brightened dramatically, the brightest auroral emissions moved to higher latitudes, and the dawn side polar regions were filled with intense emissions. The brightening is reminiscent of terrestrial aurorae, but the other two variations are not. Rather than being intermediate between the Earth and Jupiter, Saturn's auroral emissions behave fundamentally differently from those at the other planets.

Journal Article↗
PubMed2005

Vitamin D intake and status in Irish postmenopausal women.

OBJECTIVE: The objective of this study was to assess vitamin D status during late-summer and late-winter/early-spring in postmenopausal Irish women, and whether it was influenced by vitamin D-containing supplement use. DESIGN: A longitudinal observational study. SETTING: Cork City, Ireland (51 degrees north). SUBJECTS: A total of 59 apparently healthy, free-living, postmenopausal women aged between 51 and 69 y were sampled during February/March 2002. Of these, 48 and 47 returned during August/September 2002 and February/March 2003, respectively. None of the women were suffering from any medical condition likely to affect vitamin D status. Fasting serums were collected and analysed for 25-hydroxyvitamin D (25 (OH) D) and parathyroid hormone (PTH) by enzyme immunoassays. RESULTS: Mean daily intake of vitamin D was 3.2 microg from food sources alone and 5.8 microg when vitamin D-containing supplements were included (P<0.01). Serum 25 (OH) D was significantly lower (P<0.001) during February/March 2002 than both August/September 2002 and February/March 2003. Serum 25 (OH) D was also significantly higher (P < or = 0.05) in women who were vitamin D-containing supplement users than nonusers during all three sampling points. Between 17 and 36% of women had inadequate vitamin D status (defined as serum 25 (OH) D <40 nmol/l) during late-winter, but only 4% had inadequate vitamin D status during late-summer. Serum 25 (OH) D was inversely related to serum PTH (r = -0.33; P = 0.028). CONCLUSION: Suboptimal vitamin D status is common in postmenopausal Irish women during winter. Vitamin D supplementation is associated with improved vitamin D status, even during summertime.

Aged↗
PubMed2005

The relationship between the zinc nutritive status and biochemical markers of bone turnover in older European adults: the ZENITH study.

OBJECTIVE: To investigate the relationship between indices of zinc nutritive status and biochemical markers of bone turnover in older adult European subjects. DESIGN: Use of baseline data from a multicentre prospective zinc intervention (ZENITH) study. SETTING: Centres in France, Italy and Northern Ireland. PARTICIPANTS: A total of 387 healthy adults, aged 55-87 y. METHODS: Zinc intake was assessed by 4-day recall records. Circulating and urinary biochemical zinc status measures were assessed by atomic absorption spectrophometry. Serum bone-specific alkaline phosphatase and osteocalcin were assessed by ELISA and urinary pyridinoline (Pyr) and deoxypyridinoline (Dpyr) by HPLC. RESULTS: Zinc intake was negatively correlated with urinary Pyr and Dpyr (r = -0.298 and -0.304, respectively; P < 0.0001), but was not correlated with bone formation markers. There was a tendency for serum zinc to be negatively correlated with urinary Dpyr (r = -0.211; P = 0.080). Erythrocyte zinc was negatively correlated with serum osteocalcin (r = -0.090; P < 0.0001). None of the other correlations were significant. After adjustment for confounder (age, gender and research centre) the only significant association that remained was between serum osteocalcin and erythrocyte zinc (beta = -0.124; P = 0.011). CONCLUSIONS: There was some, albeit inconsistent, evidence of a relationship between zinc nutritive status and bone turnover in the older adult participants of the ZENITH study.

Aged↗
PubMed2005

Intracellular T lymphocyte cytokine profiles in the aqueous humour of patients with uveitis and correlation with clinical phenotype.

This study aimed to investigate whether T cells in aqueous humour are different in different types of uveitis and correlate with clinical phenotype. Patients with clinically different types of uveitis, but all displaying active anterior uveitis, were phenotyped and samples of aqueous humour (AH) and peripheral blood (PB) collected. Cells from AH and PB were separated by centrifugation and by density gradient centrifugation (to obtain mononuclear cells PBMC), respectively. Cells were activated with PMA and ionomycin in the presence of Brefeldin A, stained for surface markers and intracellular cytokines, and analysed by flow cytometry. The cytokine profile was correlated with the clinical phenotype. Increased percentages of interleukin (IL)-10+-, but not interferon (IFN)-gamma+ T lymphocytes were found in AH compared with PB in patients with acute anterior uveitis (AAU), FHC or chronic panuveitis (PU). There was a trend towards elevated levels of IL-10+ T cells in AH from patients with FHC compared with AH from acute uveitis and panuveitis patients. Increased levels of IL-10+ T cells in AH compared with PB were also found in samples from patients with isolated uveitis, but not those with associated systemic disease. Levels of cytokine-positive T cells were not associated with the use of topical steroids or to the severity of the anterior uveitis. While type I cytokine-producing T lymphocytes are present in AH during AU, the presence of increased proportions of IL-10+ T lymphocytes in AH from patients with uveitis may be indicative of an anti-inflammatory mechanism that may influence the type and course of ocular inflammation in these patients.

Acute Disease↗
PubMed2004

A comparison of the sports safety policies and practices of community sports clubs during training and competition in northern Sydney, Australia.

OBJECTIVES: To compare the safety policies and practices reported to be adopted during training and competition by community sports clubs in northern Sydney, Australia. METHODS: This cross sectional study involved face to face interviews, using an 81 item extensively validated questionnaire, with representatives of 163 community netball, rugby league, rugby union, and soccer clubs (response rate 85%). The study was undertaken during the winter sports season of 2000. Two separate 14 item scales were developed to analyse the level of safety policy adoption and safety practice implementation during training and competition. The statistical analysis comprised descriptive and inferential analysis stratified by sport. RESULTS: The reliability of the scales was good: Cronbach's alpha = 0.70 (competition scale) to 0.81 (training scale). Significant differences were found between the safety scores for training and competition for all clubs (mean difference 11.2; 95% confidence interval (CI) 10.0 to 12.5) and for each of the four sports: netball (mean difference 14.9; 95% CI 12.6 to 17.2); rugby league (mean difference 10.3; 95% CI 7.1 to 13.6); rugby union (mean difference 9.4; 95% CI 7.1 to 11.7); and soccer (mean difference 8.4; 95% CI 6.5 to 10.3). CONCLUSIONS: The differences in the mean competition and training safety scores were significant for all sports. This indicates that safety policies were less often adopted and practices less often implemented during training than during competition. As injuries do occur at training, and sports participants often spend considerably more time training than competing, sporting bodies should consider whether the safety policies and practices adopted and implemented at training are adequate.

Athletic Injuries↗
PubMed2003

The development of a tool to audit the safety policies and practices of community sports clubs.

Despite increased national effort directed at sports injury prevention in Australia since the mid 1990s, there is a lack of information available about the sports safety policies and practices of community sports clubs. The aim of this study was to develop a valid and reliable sports safety audit tool (SSAT) to identify these safety policies and practices. A literature review identified issues to be covered by the SSAT. Consultation with "experts" and piloting the SSAT with 19 community sports clubs in metropolitan Sydney established face and content validity. Test-retest reliability was assessed in six clubs. Inter-rater reliability was assessed using twenty-four independent representatives from eight clubs. Face and content validity studies identified issues to include in the SSAT and improvements to language and layout. Test-retest reliability was 91% (range 68-100%). Inter-rater reliability ranged from 40-65% when missing data and 'don't know' answers were included, and from 62-75% when only 'definitive' answers were included. Club presidents and secretaries provided more definitive information than other informants. A preliminary list of safety issues that clubs addressed well or poorly was identified. The SSAT is a useful tool for gathering baseline data, benchmarking and targeting sports safety interventions with community sports clubs. Club presidents and secretaries are the preferred contact point and a face-to-face interview is the best administration mode. A tool to identify safety policies and practices is now available for use by anyone supporting community sports clubs to improve safety.

Athletic Injuries↗
PubMed2001

Emergency and primary care at a Melbourne hospital: reasons for attendance and satisfaction.

The reasons for attendance, presenting health problems, functional status, pain and severity, and satisfaction with emergency and primary care were examined using routinely collected data and an interviewer-assisted survey of patients. Patients attended, mostly after hours, because they believed their health problems required hospital-based management. GPs referred for admission and further evaluation. Ethnicity, employment status, gender and age contributed to differences in access, morbidity and pain scores. Pain scores, functional status and English language skills influenced satisfaction. Culturally sensitive hospital- and community-based clinicians are important to promote better services, after-hours care, referral and triage. It is essential to have appropriate policy and legislation, adequate infrastructure and resources, good communication strategies, telecommunication technology, explicit evidence-based protocols for shared care, referral and triage and ongoing training and support for clinicians and consumers.

Adolescent↗
PubMed2001

Secreted euryarchaeal microhalocins kill hyperthermophilic crenarchaea.

Few antibiotics targeting members of the archaeal domain are currently available for genetic studies. Since bacterial antibiotics are frequently directed against competing and related organisms, archaea by analogy might produce effective antiarchaeal antibiotics. Peptide antibiotic (halocin) preparations from euryarchaeal halophilic strains S8a, GN101, and TuA4 were found to be toxic for members of the hyperthermophilic crenarchaeal genus Sulfolobus. No toxicity was evident against representative bacteria or eukarya. Halocin S8 (strain S8a) and halocin R1 (strain GN101) preparations were cytostatic, while halocin A4 (strain TuA4) preparations were cytocidal. Subsequent studies focused on the use of halocin A4 preparations and Sulfolobus solfataricus. Strain TuA4 cell lysates were not toxic for S. solfataricus, and protease (but not nuclease) treatment of the halocin A4 preparation inactivated toxicity, indicating that the A4 toxic factor must be a secreted protein. Potassium chloride supplementation of the Sulfolobus assay medium potentiated toxicity, implicating use of a salt-dependent mechanism. The utility of halocin A4 preparations for genetic manipulation of S. solfataricus was assessed through the isolation of UV-induced resistant mutants. The mutants exhibited stable phenotypes and were placed into distinct classes based on their levels of resistance.

Anti-Bacterial Agents↗
PubMed2001

Tracking the spread of a lacZ-tagged herpes simplex virus type 1 between the eye and the nervous system of the mouse: comparison of primary and recurrent infection.

The spread of herpes simplex virus type 1 (HSV-1) during primary ocular infection and after reactivation of latent infection in the trigeminal ganglion (TG) was examined in the mouse using a genetically modified virus containing the lacZ reporter gene under the control of the immediate-early 110 promoter. Whole tissue mounts of the eye and lids, their sensory nerves, and TG with the attached dorsal root entry zone (DRE) into the central nervous system (CNS) were stained for beta-galactosidase. Sixteen hours after inoculation of the cornea by scarification, staining was found in the scarified epithelium of the cornea and in the unscarified conjunctiva. By 24 h, staining was also seen in a few TG neurons and by 96 h their number had greatly increased and their distribution was more widespread. Stained cells (identified as Schwann cells by their staining for glial fibrillary acidic protein [GFAP] or S-100) in the TG were first seen close to stained neurons at 40 h, and by 48 h lines of such cells extended partway toward the periphery and toward the DRE. By 72 h, these lines had reached the periphery and the DRE where the adjacent CNS was also stained. In the cornea, stained cells with the morphology and arrangement of Schwann cells were seen from 40 to 120 h. After reactivation of latent infection, 10 of 22 samples had positively stained neurons. In eight samples, corneal and lid epithelial cells were stained. No stained Schwann cells were seen in the TG; however, branched networks of such cells were present in the cornea and the lids. This detailed sequential analysis has provided new information on the involvement of Schwann cells in the pathogenesis of primary and recurrent HSV-1 disease in the TG and the cornea.

Acute Disease↗
PubMed2001

User satisfaction: measurement and interpretation.

Over the past 5 years there has been an increased interest in assessing users' satisfaction with health care services in England. Measuring and interpreting user satisfaction with reproductive and sexual health services can be complex, and efforts have met with varying degrees of success. This paper will summarise the methods that have been used to assess user satisfaction over the past 10 years, describe a different type of approach that has been recently used in England, and provide some suggestions for approaches that may be effective in improving clinical effectiveness in the new millennium.

Family Planning Services↗
PubMed2000

Cell division, guillotining of dimer chromosomes and SOS induction in resolution mutants (dif, xerC and xerD) of Escherichia coli.

We have studied the growth and division of xerC, xerD and dif mutants of Escherichia coli, which are unable to resolve dimer chromosomes. These mutants express the Dif phenotype, which includes reduced viability, SOS induction and filamentation, and abnormal nucleoid morphology. Growth was studied in synchronous cultures and in microcolonies derived from single cells. SOS induction and filamentation commenced after an apparently normal cell division, which sheared unresolved dimer chromosomes. This has been called guillotining. Microcolony analysis demonstrated that cell division in the two daughter cells was inhibited after guillotining, and microcolonies formed that consisted of two filaments lying side by side. Growth of these filaments was severely reduced in hipA+ strains. We propose that guillotining at dif destroys the expression of the adjacent hipBA genes and, in the absence of continued formation of HipB, HipA inhibits growth. The length of the filaments was also affected by SfiA: sfiA dif hipA mutants initially formed filaments, but cell division at the ends of the filaments ultimately produced a number of DNA-negative cells. If SOS induction was blocked by lexA3 (Ind-), filaments did not form, and cell division was not inhibited. However, pedigree analysis of cells in microcolonies demonstrated that lethal sectoring occurred as a result of limited growth and division of dead cells produced by guillotining.

Bacterial Proteins↗
PubMed2000

Fluconazole for the prevention and treatment of tinea gladiatorum.

BACKGROUND: Tinea gladiatorum is a common problem in competitive wrestling. It impacts on a wrestler's ability to compete. Several methods have been advocated to prevent these infections; however, no well-designed study of pharmacologic prophylaxis has been conducted. METHODS: In a double blind placebo-controlled trial during the 1998 to 1999 regular wrestling season, wrestlers were randomized to receive 100 mg of fluconazole once weekly or placebo once weekly. Those not involved in the study were treated as a second control group. The effects of prophylaxis were also examined by assessing treatment of clinical infections with fluconazole 200 mg weekly for 4 weeks. RESULTS: There was a significantly smaller incidence of infection in those given fluconazole (6%) than in those receiving placebo (22%) and those not involved in the prophylaxis phase (18%) (P<0.05). There was also a significant reduction in the total number of infections in the fluconazole group (P<0.05). Prophylaxis with fluconazole did not impact on the severity of disease, if contracted, when compared with the placebo prophylaxis participants who contracted tinea corporis. Of 21 wrestlers with tinea infections and positive cultures, 14 were able to have their isolates identified as Trichophyton tonsurans. CONCLUSIONS: Fluconazole is effective and safe for primary prevention of tinea gladiatorum. We must now define when and in what population prophylaxis would be warranted.

Adolescent↗
PubMed2000

Method for determining antiphase dynamics in a multimode laser

We measure the cross spectrum of the intensity fluctuations of pairs of modes for a multilongitudinal mode neodymium-doped yttrium aluminum garnet laser operating in the steady state regime. From the data we build up a picture of how the longitudinal mode fluctuations interfere and directly show the antiphase dynamics of the intensity fluctuations.

Journal Article↗
PubMed1999

Barriers to effective communication in skilled nursing facilities: differences in perception between nurses and physicians.

BACKGROUND: Effective communication between nurses and physicians is central to the clinical care of nursing home residents. Anecdotal evidence suggests that communication between the groups is unsatisfactory, but no empirical data exist with which to validate assumptions. The purpose of this pilot study was to compare perceptions of potential communication barriers among nurses and physicians in four California nursing homes. METHODS: Registered nurses (n = 59), and physicians (n = 47) involved in the direct clinical care of nursing home residents completed a 12-item questionnaire designed to elicit perceptions about potential communication barriers. Five specific categories of barriers were identified. These included nurse competence, time burden of calls, necessity of calls, professional respect, and language comprehension. Responses were compared using t test analysis. RESULTS: Significant differences in perceived communication barriers were identified. Physicians, but not nurses, perceive nursing competence to be a significant barrier. Nurses perceive physicians to be unpleasant. Both physicians and nurses perceive that physicians do not value nurses' opinions. Neither group perceived language expression, language comprehension, or time burden of phone calls to be barriers to communication. CONCLUSIONS: Issues related to the perceived competency of nurses by physicians is consistent with existing data from other clinical settings. Differences in awareness about scope of practice and regulatory requirements between the groups may offer a partial explanation for the discordant perceptions. Perceptions by nurses (but not physicians) of unpleasantness and/or disrespect during telephone encounters may reflect the broader ongoing differences in professional culture, social status, and gender inequality between the two groups. Further clarification of the causes of barriers to effective communication is essential in order to plan appropriate interventions.

Adult↗
PubMed1999

Validation of the Health of the Nation Outcome Scales.

BACKGROUND: The Health of the Nation Outcome Scales (HoNOS) were developed to assess the outcome of severe mental disorders in relation to the Health of the Nation Strategy for England. AIMS: To validate the HoNOS. METHOD: One hundred and fifteen patients were assessed by keyworkers using HoNOS, and by research workers using SCAN, SBS, and SRPS, and completing HoNOS in the light of this additional material. These assessments were repeated after 6 weeks. RESULTS: The performance of HoNOS in the hands of keyworkers was generally poor, in relation both to the research workers' rating of HoNOS and to the criterion instruments. Performance was particularly poor when the change in scores was used as a measure of outcome. CONCLUSIONS: There are serious problems in using HoNOS as a routine measure of clinical status in busy psychiatric services. Its performance is probably related to the training and experience of keyworkers. Sequential ratings are not a good method for assessing outcome. Managers and planners should be cautious in adopting HoNOS, but it is worthy consideration in developing a suite of locally agreed outcome measures.

Bias↗