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Biomedical subjects

S Holmes

Publications and source records attributed to S Holmes.

At least 91 records · Page 5Linked to original sources
PubMed1997

Nutrition in patients undergoing radiotherapy.

The metabolic changes accompanying cancer can contribute to a negative energy balance and weight loss. Many people with cancer will require additional nutritional support. Radiotherapy to the gastro-intestinal tract can cause debilitating symptoms affecting the ability to maintain nutritional intake.

Humans↗
PubMed1996

Bootstrap confidence levels for phylogenetic trees.

Evolutionary trees are often estimated from DNA or RNA sequence data. How much confidence should we have in the estimated trees? In 1985, Felsenstein [Felsenstein, J. (1985) Evolution 39, 783-791] suggested the use of the bootstrap to answer this question. Felsenstein's method, which in concept is a straightforward application of the bootstrap, is widely used, but has been criticized as biased in the genetics literature. This paper concerns the use of the bootstrap in the tree problem. We show that Felsenstein's method is not biased, but that it can be corrected to better agree with standard ideas of confidence levels and hypothesis testing. These corrections can be made by using the more elaborate bootstrap method presented here, at the expense of considerably more computation.

Animals↗
PubMed1996

Bootstrap confidence levels for phylogenetic trees.

Evolutionary trees are often estimated from DNA or RNA sequence data. How much confidence should we have in the estimated trees? In 1985, Felsenstein [Felsenstein, J. (1985) Evolution 39, 783-791] suggested the use of the bootstrap to answer this question. Felsenstein's method, which in concept is a straightforward application of the bootstrap, is widely used, but has been criticized as biased in the genetics literature. This paper concerns the use of the bootstrap in the tree problem. We show that Felsenstein's method is not biased, but that it can be corrected to better agree with standard ideas of confidence levels and hypothesis testing. These corrections can be made by using the more elaborate bootstrap method presented here, at the expense of considerably more computation.

Algorithms↗
PubMed1996

Circulating leptin levels are modulated by fasting, cold exposure and insulin administration in lean but not Zucker (fa/fa) rats as measured by ELISA.

The development of a sensitive enzyme-linked immunosorbent assay (ELISA) is described for the quantitation of plasma leptin levels in both mice and rats. Approximately 1.5 ng leptin/ml plasma was detected in lean mice but significantly (p < 0.01) less was found in the plasma of ob/ob mice. In lean Zucker rats leptin circulated at approximately 4ng/ml plasma whereas levels were elevated more than 6-fold in fa/fa rats. Circulating leptin levels declined (p < 0.05) in lean rats which were fasted or exposed to 4 degrees C for 24h, but subsequently recovered to normal within 12h of refeeding or warming, respectively. Administration of insulin increased leptin levels in lean rats within 4h (p < 0.01). However, leptin levels were unchanged in fa/fa rats exposed to the same physiological stimuli.

Acclimatization↗
PubMed1994

Dehydration: burden or benefit to the dying patient?

Significant numbers of patients die each year from malignant disease. The question of whether or not to administer artificial hydration therapy to the patient who is in the last few days of life has been discussed for some time. Some health care professionals contend that a reduced fluid intake, which often accompanies the dying process, may result in a potentially painful and distressing state of dehydration, requiring preventative measures of fluid replacement therapy. In contrast, other clinicians suggest that artificial hydration is often of no proven benefit in the context of the dying and may impose additional physical and psychological burdens on the patient. This paper investigates the advantages and disadvantages of artificial hydration therapies in terms of the symptom distress experienced by the terminally ill cancer patient. Its aim is to promote discussion about this vital aspect of patient care.

Attitude of Health Personnel↗
PubMed1994

Mutations of the tyrosinase gene in patients with oculocutaneous albinism from various ethnic groups in Israel.

We have analyzed the tyrosinase (TYR) gene in 38 unrelated patients with oculocutaneous albinism (OCA), derived from several different ethnic groups of the diverse population of Israel. We detected TYR gene mutations in 23 of the 34 patients with apparent type I (i.e., tyrosinase-deficient) OCA and in none of the patients with other clinical forms of albinism. Among Moroccan Jews with type IA (i.e., tyrosinase-negative) OCA, we detected a highly predominant mutant allele containing a missense substitution, Gly47Asp (G47D). This mutation occurs on the same haplotype as in patients from the Canary Islands and Puerto Rico, suggesting that the G47D mutation in these ethnically distinct populations may stem from a common origin.

Adolescent↗
PubMed1993

Food avoidance in patients undergoing cancer chemotherapy.

Cancer and its treatment are known to cause malnutrition in significant numbers of patients. Although a variety of contributory factors have been identified it is clear that the aetiology of malnutrition is complex and multifactorial. Taste aberrations are believed to be amongst the causative factors and to contribute to the development of food avoidance/aversion in affected patients. The study described investigates the incidence of food avoidance in a random sample of 72 patients undergoing cancer chemotherapy. The results show that 59 (82%) had avoided one or more foods since the instigation of treatment. The foods most commonly affected were coffee, tea, citrus fruit, chocolate and red meat. Changes were noted in the consumption of both sweet and salty foods. In terms of food avoidance no apparent relationships were demonstrated between its incidence and either the type of disease or the drugs used in therapy. In men, the pattern of avoidance showed no differences between the younger (up to 49 years) and older (50 years and older) patients; marked differences were observed between younger and older women. Although the foods avoided in general have little nutritional implication their omission may affect the quality of the patient's life. Food avoidance per se may, however, affect nutritional status; suggestions for overcoming its effects are made. The results of this study, obtained by subjective assessment of food acceptability, highlight the individual nature of food avoidance in affected patients and suggest that each must be individually assessed if appropriate nutritional advice is to be given.

Adolescent↗
PubMed1993

Cognitive-linguistic assessment of individuals with multiple sclerosis.

Four individuals diagnosed as having multiple sclerosis (MS) and four matched controls were assessed with the Arizona Battery for Communication Disorders (ABCD), a standardized battery of memory and cognitive-linguistic tasks. Subjects with MS and controls performed in an equivalent or nearly equivalent fashion for nine of the ABCD subtests. For five of the subtests (Object Description, Generative Naming, Concept Definition, Generative Writing, and Picture Description), subjects with MS performed substantially lower than the control subjects. Results of this pilot study suggest that portions of the ABCD may be useful in identifying profiles of memory, and cognitive-linguistic impairment among individuals with multiple sclerosis. Further research using a larger sampling of individuals with MS is needed to more fully assess the usefulness of the ABCD with this population.

Adult↗
PubMed1993

Segregation and linkage analysis in five manic depression pedigrees excludes the 5HT1a receptor gene (HTR1A).

Five kindreds selected through probands attending an Icelandic hospital were recruited for linkage studies of manic depression. The rates of affection were equal for males and females and the age of onset appeared to be predominantly in early adult life, since prevalence did not rise appreciably with age. A complex segregation analysis was performed using the computer program POINTER to obtain maximum likelihood estimates of the contributions to liability from multifactorial transmission and a single major locus. Likelihood ratios between models supported a role for a single major locus which was dominant and had moderately high penetrance with, in the case of unipolar illness, additional multifactorial transmission. The best-fitting parameters were used to devise a transmission model for linkage analysis. Three markers on chromosome 5 were studied, at D5S76, D5S6 and D5S39. Strongly negative lod scores were obtained which were less than -2 over a distance of 40 cM, which included the region to which the gene for the 5HT1a receptor has been mapped.

Bipolar Disorder↗
PubMed1993

Assay of brain natriuretic peptide (BNP) in human plasma: evidence for high molecular weight BNP as a major plasma component in heart failure.

A RIA for human brain natriuretic peptide (BNP) was developed. Both BNP and atrial natriuretic peptide (ANP) were extracted from human plasma with Vycor glass powder (71% recovery for BNP). The assay had a minimum detection limit of 0.45 fmol/tube and an IC50 of 9 fmol/tube. The within-assay coefficients of variation were 11.4% at 4 pmol/L and 3.2% at 22 pmol/L, and the between-assay coefficient of variation was 11% at 24 pmol/L. There was no significant loss of immunoreactive (IR)-BNP in plasma samples stored at -80 C for 4 weeks. Low rates of labeled BNP and IR-BNP degradation occurred in EDTA plasma incubated at 37 C. The mean venous plasma IR-BNP (6.3 +/- 0.3 pmol/L) in normal subjects (n = 48) was significantly lower than plasma ANP (8.4 +/- 0.6 pmol/L). In contrast to ANP, IR-BNP did not increase when normotensive or hypertensive subjects changed from erect to supine posture. Markedly elevated levels were found in patients with congestive heart failure (mean IR-BNP, 87 +/- 11 pmol/L; ANP, 87 +/- 12 pmol/L; n = 35), recent myocardial infarction (mean IR-BNP, 60 +/- 9 pmol/L; ANP, 33 +/- 6 pmol/L; n = 7), and chronic renal failure. High pressure liquid chromatography of plasma extracts from heart failure subjects revealed both high (mol wt, 10,000) and low (mol wt, 4,000) mol wt IR-BNP. High mol wt BNP was the major component (mean ratio, 1.9:1) and was linearly correlated with low mol wt BNP (r = 0.99). HPLC of plasma extracts from three normal subjects receiving constant infusions of human BNP (2 pmol/kg.min) showed a single major peak eluting in the position of hBNP-32, with no evidence of high mol wt material. These results show that whereas marked elevations in BNP occur in circulatory disorders, a major (> 50%) and consistent contribution to immunoreactivity is due to precursor forms. Further, compared to ANP, there is no IR-BNP response to supine posture in normal and hypertensive subjects.

Adult↗
PubMed1993

A positive response to an adverse reaction. Diagnosis and management of food intolerance in children.

1. Food intolerance is a reproducible abnormal reaction to food or food components which is not psychologically based. 2. It is straightforward to identify immediate hypersensitivity, but delayed reactions (4-27 hours) are more difficult. 3. The main foods causing reactions are wheat, milk, chicken, eggs, fish and shellfish, but any food can cause a reaction in a sensitised individual. 4. The solution to the problem relies on identification of the causative food(s) and its total elimination from the diet.

Child↗