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Biomedical subjects

A Williams

Publications and source records attributed to A Williams.

At least 289 records · Page 16Linked to original sources
PubMed1997

A gene fusion at a homeobox locus: alterations in leaf shape and implications for morphological evolution.

Compound leaves are seen in many angiosperm genera and are thought to be either fundamentally different from simple leaves or elaborations of simple leaves. The knotted1-like homeobox (knox) genes are known to regulate plant development. When overexpressed in homologous or heterologous species, this family of genes can cause changes in leaf morphology, including excessive leaf compounding in tomato. We describe here an instance of a spontaneously arisen fusion between a gene encoding a metabolic enzyme and a homeodomain protein. We show that the fusion results in overexpression of the homeodomain protein and a change in morphology that approximates the changes caused by overexpression of the same gene under the control of the cauliflower mosaic virus 35S promoter in transgenic plants. Exon-shuffling events can account for the modularity of proteins. If the shuffled exons are associated with altered promoters, changes in gene expression patterns can result. Our results show that gene fusions of this nature can cause changes in expression patterns that lead to altered morphology. We suggest that such phenomena may have played a role in the evolution of form.

Base Sequence↗
PubMed1997

Two-dimensional film dosimetry application in heterogeneous materials exposed to megavoltage photon beams.

Measurement of dose within tissues and tissue interfaces having sharp density discontinuities and heterogeneities (such as in the lung, esophagus, and rectum) is essential for treatment plan verification and accurate prediction of the prescribed dose. This study examines the feasibility and utility of simplifying standard film dosimetry to measure dose distributions deposited by megavoltage beams in tissue substitutes (such as cork for lung) and anthropomorphic phantoms which closely resemble human tissues having large density heterogeneities and having sharp tissue interfaces. In addition, film dosimetry determined the dose distribution involving superposition of multiple radiation fields and helped evaluate the accuracy of a commercial treatment planning program which incorporates tissue heterogeneity effects through the "effective path length" algorithm. This study shows that these treatment planning programs and simple calculations overestimate the dose delivered within the lower density material in heterogeneous regions.

Biophysical Phenomena↗
PubMed1997

Development of a modified paediatric coma scale in intensive care clinical practice.

James' adaptation of the Glasgow coma scale (JGCS) was designed for young children. Intubated patients are not allocated a verbal score, however, so important changes in a patient's conscious level may be missed. A grimace score was therefore developed and assessed for use in intubated children. Two observers made a JGCS observation within 15 minutes of each other. One observer was the patient's nurse and the other a trained investigator. Interobserver reliability was determined between the first and second observation for each component of the scale. Reliability was measured using kappa and weighted kappa statistics. Seventy three children had 104 sets of observations. Interobserver reliability was moderate to good for all components, with the grimace score better than the verbal score. It is concluded that the grimace score is more reliable than the verbal score and may be useful in intubated patients in whom the verbal score cannot be used.

Adolescent↗
PubMed1997

You won't know unless you ask: the biopsychosocial interview for adolescents.

In order to impact morbidity and mortality of adolescents, the health care provider must not only determine the risk status of the teenager but also take time to provide appropriate guidance and interventions. We have developed the West Virginia University Adolescent Risk Score, which is more inclusive than similar screening techniques and requires an 8 +/- 3-minute interview. This format facilitates specific guidance, provides documentation of risk status, and is readily accessible on future visits. Our data provide the basis for planning and research regarding the effectiveness of interventions.

Adolescent↗
PubMed1997

A cost analysis of a tele-oncology practice.

Costs were monitored for three different types of oncology practice: a telemedicine clinic and a fly-in outreach clinic, both held in rural areas, and a traditional clinic held in a city hospital. Total expenses were calculated over the year May 1995 to April 1996. The average cost per telemedicine visit was $812. The average cost per outreach clinic visit was $897. Flying in oncology support for this practice was therefore about 10% more costly than telemedicine. While the outreach cost may have been inappropriately high due to a slow start-up phase, it was still less expensive during this period to be seen via telemedicine. For comparison, the average cost per traditional oncology clinic visit was $149. However, this figure does not take into account the costs of access to a city-based service by rural patients.

Cost-Benefit Analysis↗
PubMed1997

Lymphoedema.

Explore the source record for details and available documents.

Bandages↗
PubMed1997

Serum C-reactive protein as a marker for infection and inflammation in regular dialysis patients.

Serum C-reactive protein (CRP) concentration was measured in 98 hemodialysis (HD) patients and 68 continuous ambulatory peritoneal dialysis patients (CAPD). The effect, if any, of a HD session on serum CRP level and the usefulness of CRP in diagnosing and monitoring proven inflammatory disease were studied. Seventy-five percent of CAPD patients without evidence of inflammation had CRP levels within the quoted normal range (< 10 mg/l), as compared with only 47% of HD patients also without evidence of overt inflammation (p < 0.001). No significant change in the CRP level was detected during a hemodialysis session. Twenty-four patients with overt inflammation (due mainly to infection) were studied, 22 of whom had CRP levels of > 50 mg/l. These increased CRP levels fell with treatment. A CRP level of > 50 mg/l proved highly suggestive of a significant inflammatory process and a value of < 10 mg/l always excluded it. The total period of time on the regular dialysis program was not related to the CRP level. A subclinical inflammatory response resulting in a raised CRP is very common in our hemodialysis patients and less so in CAPD patients. Possible reasons for this are discussed. However, CRP is still useful in the diagnosis and monitoring of response to treatment of inflammatory disease if the level is > 50 mg/l or serial/baseline measurements are available for comparison. Whether any relationship exists between elevation of CRP and the well-documented increased risk of cardiovascular death in dialysis patients is currently unknown.

Adolescent↗
PubMed1996

An adenovirus mutant that replicates selectively in p53-deficient human tumor cells.

The human adenovirus E1B gene encodes a 55-kilodalton protein that inactivates the cellular tumor suppressor protein p53. Here it is shown that a mutant adenovirus that does not express this viral protein can replicate in and lyse p53-deficient human tumor cells but not cells with functional p53. Ectopic expression of the 55-kilodalton EIB protein in the latter cells rendered them sensitive to infection with the mutant virus. Injection of the mutant virus into p53-deficient human cervical carcinomas grown in nude mice caused a significant reduction in tumor size and caused complete regression of 60 percent of the tumors. These data raise the possibility that mutant adenoviruses can be used to treat certain human tumors.

Adenovirus E1B Proteins↗
PubMed1996

Purchasing. The wasted millions.

In the wake of the Child B rationing controversy, the Anti-Rationing Group challenged purchasers to allow them to scrutinise their practice. Eight health authorities accepted and, say Colin Roberts and colleagues, the results show public money being needlessly wasted on a staggering scale.

Community Health Services↗
PubMed1996

Observations on the transmission of scrapie in experiments using embryo transfer.

This investigation studied the maternal transmission of scrapie in sheep by using embryo transfer to examine the viability of highly susceptible offspring derived from scrapie-affected and uninfected donors. The study also examined the effect of washing the embryos. Scrapie occurred in both washed and unwashed embryo-derived Sip sAsA progeny from both groups of donor ewes. As a result, the earlier observation that scrapie might pass via the unwashed embryo to develop as disease in adult sheep has to be reassessed. Several other implications of the work are considered, including the possibility that natural scrapie is not purely a genetic disease.

Alleles↗