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Biomedical subjects

H Evans

Publications and source records attributed to H Evans.

At least 37 records · Page 2Linked to original sources
PubMed1999

T2 vertebral bone marrow changes after space flight.

Bone biopsies indicate that during immobilization bone marrow adipose tissue increases while the functional cellular fraction decreases. One objective of our Spacelab flight experiment was to determine, using in vivo volume-localized magnetic resonance spectroscopy (VLMRS), whether bone marrow composition was altered by space flight. Four crew members of a 17 day Spacelab mission participated in the experiment. The apparent cellular fraction and transverse relaxation time (T2) were determined twice before launch and at several times after flight. Immediately after flight, no significant change in the cellular fraction was found. However, the T2 of the cellular, but not the fat component increased following flight, although to a variable extent, in all crew members with a time course for return to baseline lasting several months. The T2 of seven control subjects showed no significant change. Although these observations may have several explanations, it is speculated that the observed T2 changes might reflect increased marrow osteoblastic activity during recovery from space flight.

Adult↗
PubMed1999

Loss of chromosome 10 is an independent prognostic factor in high-grade gliomas.

Loss of heterozygosity (LOH) for chromosome 10 is the most frequent genetic abnormality observed in high-grade gliomas. We have used fluorescent microsatellite markers to examine a series of 83 patients, 34 with anaplastic astrocytoma (grade 3) and 49 with glioblastoma multiforme (grade 4), for LOH of chromosome 10. Genotype analysis revealed LOH for all informative chromosome 10 markers in 12 (35%) of patients with grade 3 and 29 (59%) grade 4 tumours respectively, while partial LOH was found in a further eight (24%) grade 3 and ten (20%) grade 4 tumours. Partial LOH, was confined to the long arm (10q) in six and the short arm (10p) in three cases, while alleles from both arms were lost in four cases. Five tumours (one grade 3 and four grade 4) showed heterogeneity with respect to loss at different loci. There was a correlation between any chromosome 10 loss and poorer performance status at presentation (chi2 P = 0.005) and with increasing age at diagnosis (Mann-Whitney U-test P = 0.034) but not with tumour grade (chi2 p= 0.051). A Cox multivariate model for survival duration identified age (proportional hazards (PH), P= 0.004), grade (PH, P= 0.012) and any loss of chromosome 10 (PH, P= 0.009) as the only independent prognostic variables. Specifically, LOH for chromosome 10 was able to identify a subgroup of patients with grade 3 tumours who had a significantly shorter survival time. We conclude that LOH for chromosome 10 is an independent, adverse prognostic variable in high-grade glioma.

Brain Neoplasms↗
PubMed1998

Phase I trial of temozolomide using an extended continuous oral schedule.

Temozolomide, a methylating imidazotetrazinone, has antitumor activity against gliomas, malignant melanoma, and mycosis fungoides and is presently administered as a 5-day oral schedule every 4 weeks. This Phase I study aimed to determine the maximum tolerated dose of temozolomide administered as a single oral daily dose for a continuous 6- or 7-week period, evaluate the plasma pharmacokinetics on this schedule, and compare total plasma exposure over 7 weeks with the conventional 5-day regimen. Twenty-four patients with varying tumor types (17 of 24 gliomas) received temozolomide. All had clinically evaluable, refractory disease; normal renal, hepatic, and bone marrow function; and WHO performance status < or = 2. Temozolomide was administered at 50 mg/m2/day, increasing by 25 mg/m2/day/cohort until at 100 mg/m2/day grade 4 myelotoxicity forced dose reductions to 85 mg/m2/day, then 75 mg/m2/day. At 75 mg/m2/day the regimen was extended to 7 weeks, allowing the future potential combination with irradiation for primary gliomas. Patient responses (standard Union International Contre Cancer criteria; for gliomas objective response) and toxicity were assessed. Temozolomide plasma pharmacokinetics were determined on day 1 and at the beginning of the final week of administration (n = 5). The most frequent toxicities were myelosuppression and grades 1 and 2 nausea and vomiting. Grade 4 leucopenia and thrombocytopenia occurred in one of four patients receiving 100 mg/m2/day temozolomide and in one of seven patients receiving 85 mg/m2/day. These hematological toxicities did not exceed grade 2 in 10 patients receiving 75 mg/m2/day temozolomide. One of 4 malignant melanoma patients and 7 of 17 glioma patients (41%) demonstrated tumor responses. The overall response rate for this prolonged schedule was 33% (objective response, 7 of 24 patients; partial response, 1 of 24 patients); also, 6 of 17 glioma patients maintained SD. Peak plasma temozolomide concentrations were obtained 30-90 min after oral administration. Elimination in plasma was best described by a monoexponential equation with an elimination half-life of 96 +/- 16 min. No plasma accumulation of temozolomide occurred. Toxicity was greatest in higher dose cohorts, with a resultant maximum tolerated dose of 85 mg/m2/day, whereas lower dose cohorts tolerated the schedule well. The area under the temozolomide plasma versus time curve was noncumulative between the first and last week of the schedule. Temozolomide administration of 75 mg/m2/day over a 7-week period permits a 2.1-fold greater drug exposure/4 weeks in comparison with the 5-day schedule of 200 mg/m2/day repeated every 28 days. The overall response rate was 33% (glioma patients, 41% and a further 25% SD). Temozolomide (75 mg/m2/day) for 7 weeks is the recommended starting dose for further assessment of this schedule.

Administration, Oral↗
PubMed1998

Evaluation of three aggression/agitation behaviour rating scales for use on an acute admission and assessment psychogeriatric ward.

BACKGROUND: In recent years many instruments measuring aggressive and agitated behaviours among the elderly in a variety of settings have emerged. Individual instruments have only occasionally been compared with each other. METHOD: Some psychometric properties of three aggression/agitation scales on an acute assessment and admission psychogeriatric ward were examined. The correlation between the Rating Scale for Aggressive Behaviour in the Elderly (RAGE), the Cohen-Mansfield Agitation Inventory (CMAI) and the Brief Agitation Rating Scale (BARS) and their internal consistencies and test-retest and interrater reliabilities were measured. RESULTS: The RAGE was strongly correlated with the CMAI (rho = +0.73) and the BARS (rho = +0.72). The CMAI was strongly correlated with the CMAI (rho = +0.84). The internal consistency, as measured by Cronbach's alpha, was greater than 0.8 on all three scales. The test-retest and interrater reliability correlations were 0.75 or greater for all three scales (except the BARS interrater reliability correlation of 0.6). CONCLUSIONS: All three scales have good psychometric properties for use in acute admission assessment psychogeriatric wards.

Aged↗
PubMed1998

The development of Healthcare Resource Groups--Version 3.

The use of casemix classifications to assist in the analysis of patient-based information is becoming more widespread and routine in the management of the National Health Service (NHS). This paper details the process of modification of and the results of modifications to Healthcare Resource Groups (HRGs), an in-patient classification tailor-made for the English healthcare system. Clinical expertise and extensive statistical analysis of national data were combined to identify areas of HRGs Version 2 where improvement could be made. The ensuing changes were then reviewed by professional associations and the wider NHS before being incorporated into grouping software. Extensive changes were made to the classification, with significant gains in statistical performance. Analysis shows that the revised groupings perform better on English data than other available systems.

Diagnosis-Related Groups↗
PubMed1998

Gross anatomy of the pancreatic lobes and ducts in six breeds of domestic ducks and six species of wild ducks in China.

A previously unreported pancreatic duct was found by Liu (1989) in Pekin ducks. This duct has now been consistently found in six breeds of domestic ducks and six species of wild ducks in China. For purposes of Nomina Anatomica Avium it is hereby called the 'first pancreatic duct' (Ductus pancreaticus primus) since it enters the duodenum at or near the flexure where the descending duodenum becomes the ascending duodenum. All other pancreatic ducts enter the duodenum later, closer to where it joins the jejunum. This first pancreatic duct drains the caudal extremity of the dorsal lobe of the pancreas and can be easily exteriorized for experimental purposes. Within the parenchyma of the dorsal lobe of the pancreas this duct communicates with the dorsal pancreatic duct. In the present study of the gross anatomy of the pancreatic lobes of domestic and wild Chinese ducks we describe and illustrate variations in position and number of all biliary and pancreatic ducts.

Animals↗
PubMed1997

FaFEC: a novel regimen for advanced ovarian cancer.

A palliative combination chemotherapy regimen (FaFEC) was developed for patients with relapsed epithelial ovarian cancer in particular patients relapsing after, or ineligible to enter, phase II trials, usually due to lack of evaluable disease. Forty-six patients were enrolled. Patients had received a mean of 2.3 previous drug regimens and nine (19%) had intestinal obstruction at the start of FaFEC. The majority of patients were inevaluable by WHO criteria so objective response data was obtained from serial serum CA125 evaluations. A serological response was demonstrated in 8/44 (18%). The responders included 6/27 women who had a prior relapse-free interval of less than 3 months, four who were resistant to platinum chemotherapy and three patients who had previously received paclitaxel. The major (WHO grade 3/4) toxicities included leucopenia (six patients), anemia (three patients), thrombocytopenia (two patients), nausea and vomiting (four patients) and severe infections (five patients). Following FaFEC the median time to failure was 0.48 years and the median survival was 0.66 years. FaFEC was effective in this group of very poor prognosis patients. The serological response rate of 18% is noteworthy considering the multiple prior treatments that patients had received and the short treatment free intervals. FaFEC may be useful second line therapy in epithelial ovarian cancer patients ineligible for phase II studies and should be considered for a randomized comparison with paclitaxel.

Journal Article↗
PubMed1997

Thyroid-stimulating hormone and total thyroxine concentrations in euthyroid, sick euthyroid and hypothyroid dogs.

Canine thyroid-stimulating hormone (cTSH) was measured in a variety of clinical cases (n = 72). The cases were classified as euthyroid, sick euthyroid, hypothyroid or hypothyroid on nonthyroidal therapy on the basis of their history, clinical signs, laboratory results (including total thyroxine concentrations and, where indicated, thyroid-releasing hormone [TRH] stimulation tests) and response to appropriate therapy. Additional samples were taken during some of the TRH stimulation tests to measure the response of cTSH concentrations following TRH administration. A reference range (0 to 0.41 ng/ml) was calculated from the basal concentrations of cTSH in a group of 41 euthyroid dogs. Six of nine cases of confirmed hypothyroidism had basal cTSH concentrations above the reference range, whereas the remainder were within the normal range. One of these three remaining cases was a pituitary dwarf and did not show a rise in cTSH concentration following TRH stimulation. In contrast, only one of a group of six hypothyroid dogs that had been on non-thyroidal treatment within the previous four weeks had increased concentrations of basal cTSH. This study also found that five of a group of 16 dogs with sick euthyroid syndrome had increased cTSH concentrations. It was concluded that cTSH measurements are a useful additional diagnostic test in cases of suspected hypothyroidism in dogs but that dynamic testing is still required to confirm the diagnosis of hypothyroidism.

Animals↗
PubMed1997

Phase II trial of oral altretamine for relapsed ovarian carcinoma: evaluation of defining response by serum CA125.

PURPOSE: A phase II study was performed of oral altretamine in 71 patients with ovarian carcinoma who entered clinical complete remission with CA125 levels less than 35 U/mL after initial or second-line chemotherapy, and relapsed more than 6 months later. Response was compared between standard and CA125-based criteria. PATIENTS AND METHODS: Altretamine 260 mg/m2 was given in divided doses daily for 14 days per month. Response was evaluated according to European Organization for Research and Treatment of Cancer (EORTC) criteria in 45 of 66 eligible patients. Response was assessed according to precise CA125 criteria in 51 patients based on either a confirmed > or = 50% or > or = 75% decrease in CA125 levels. RESULTS: A combination of domperidone, dexamethasona, and chlorpromazine at night controlled toxicity in most patients, which was mainly nausea (National Cancer Institute criteria grade 2 or 3 in 27), vomiting (grade 2 or 3 in 19, grade 4 in one), and tiredness (grade 2 or 3 in 15). Responses (complete plus partial) were seen in 18 (40%; 95% confidence interval [CI], 25.4% to 54.6%) of those evaluated according to EORTC criteria and in 20 (39%; 95% CI, 25.5% to 52.9%) of those evaluated according to CA125 level. The overall response rate was 26 of 57 (45.6%) and was related to treatment-free interval: 6 to 12 months, 35%; 12 to 24 months, 52%; and greater than 24 months, 67%. The medium duration of response was 8 months. CONCLUSION: Oral altretamine is a useful agent in patients-who relapse after previously responsive ovarian cancer. Response evaluation by a strict CA125 definition gave a similar estimate of the efficacy of altretamine as EORTC criteria.

Administration, Oral↗
PubMed1996

Transport properties of the human cartilage endplate in relation to its composition and calcification.

STUDY DESIGN: The transport properties of solutes of different sizes and conformations were studied in cartilage endplates. OBJECTIVES: The results were correlated with the composition of the cartilage matrix to determine if a relationship existed between this and the movement of molecules within it. SUMMARY OF BACKGROUND DATA: Solute transport through the hyaline cartilage endplate is important not only for the physiologic and metabolic processes of that tissue, but also for those of the adjacent intervertebral disc. Movement of solutes depends on solute size, shape or charges, and the composition of the matrix itself. Changes in composition of the cartilage endplate, such as those that occur in degeneration or scoliosis, may affect transport. METHODS: Partition and diffusion coefficients of solutes ranging in molecular weight from 115 to 70,000 d have been measured on cores of cartilage endplate. Transport properties were assessed in relation to core composition. RESULTS: The shape and size of the solutes were found to affect their transport through cartilage matrix, with larger molecules being more highly excluded and diffusing more slowly. Long-chain polymers were able to penetrate the matrix less readily than the more globular molecules. The more hydrated the matrix, the higher the degree of penetration and the more easily solutes could move, in contrast to the inverse relationship between the other components of the matrix and solute transport. With increased proteoglycan, collagen, or calcification in the tissue, there was greater restriction of solute movement. CONCLUSIONS: The proteoglycans normally found in the endplate regulate movement of solutes into and out of the disc. It has been shown previously that removal of proteoglycans from the endplate accelerates the loss of proteoglycans from the nucleus. Hence, a major function of the cartilage endplate may be to prevent fragments of osmotically active proteoglycans from leaving the disc.

Adolescent↗
PubMed1996

Secondary radiation environments in heavy space vehicles and instruments.

Secondary radiations produced by the interactions of primary cosmic rays and trapped protons with spacecraft materials and detectors provides an important, and sometimes dominant, radiation environment for sensitive scientific instruments and biological systems. In this paper the success of a number of calculations in predicting a variety of effects will be examined. The calculation techniques include Monte Carlo transport codes and semi-empirical fragmentation calculations. Observations are based on flights of the Cosmic Radiation Environment and Activation Monitor at a number of inclinations and altitudes on Space Shuttle. The Shuttle experiments included an active cosmic-ray detector as well as metal activation foils and passive detector crystals of sodium iodide which were counted for induced radioactivity soon after return to earth. Results show that cosmic-ray secondaries increase the fluxes of particles of linear energy transfer less than 200 MeV/(gm cm-2), while the activation of the crystals is enhanced by about a factor of three due to secondary neutrons. Detailed spectra of induced radioactivity resulting from spallation products have been obtained. More than a hundred significant radioactive nuclides are included in the calculation and overall close agreement with the observations is obtained.

Computer Simulation↗
PubMed1996

The Charing Cross Hospital experience with temozolomide in patients with gliomas.

Temozolomide, a new oral cytotoxic agent, was given to 75 patients with malignant gliomas. The schedule used was for the first course 150 mg/m2 per day for 5 days (i.e. total dose 750 mg/m2), escalating, if no significant myelosuppression was noted on day 22, to 200 mg/m2 per day for 5 days (i.e. total dose 1000 mg/m2) for subsequent courses at 4-week intervals. There were 27 patients with primary disease treated with two courses of temozolomide prior to their radiotherapy and 8 (30%) fulfilled the criteria for an objective response. There were 48 patients whose disease recurred after their initial surgery and radiotherapy and 12 (25%) fulfilled the criteria for an objective response. This gave an overall objective response rate of 20 (27%) out of 75 patients. Temozolomide was generally well tolerated, with little subjective toxicity and predictable myelosuppression. However, the responses induced with this schedule were of short duration and had relatively little impact on overall survival. In conclusion, temozolomide given in this schedule has activity against high grade glioma. However, studies evaluating chemotherapy in primary brain tumours should include a quality-of-life/performance status evaluation in addition to CT or MRI scanning assessment.

Adult↗
PubMed1996

Investigation of the reproductive and growth hormone status of dogs affected by idiopathic recurrent flank alopecia.

The reproductive and growth hormone status of a group of 12 neutered dogs affected by idiopathic recurrent flank alopecia was investigated at both maximum and minimum photoperiod using the adrenocorticotrophic hormone (ACTH) stimulation test, the xylazine stimulation test and the insulin-like growth factor I (IGF-I) assay. When compared with a group of nine neutered control dogs, the plasma reproductive hormone concentrations were not significantly different with one exception; a significantly greater post-ACTH plasma progesterone concentration was detected in the affected group at minimum photoperiod (P < 0.05). The significance of this finding in isolation is unclear. Growth hormone response to intravenous xylazine was assessed in the affected group at maximum photoperiod only and was found to be within normal limits in eight of the dogs. Serum IGF-I concentrations were significantly greater in the affected group at maximum photoperiod but the groups were not significantly different at minimum photoperiod. These results suggest that dogs with idiopathic recurrent flank alopecia are of normal reproductive and growth hormone status.

17-alpha-Hydroxyprogesterone↗
PubMed1996

Urinary tract infection in adolescent boys.

Clinical and laboratory features of 21 adolescent males with urinary tract infections were studied. Sixty-seven percent were symptomatic and 80% revealed abnormalities on initial urinalysis. Forty-eight percent showed structural anomalies of the urinary tract. Recurrences were observed only in those having abnormalities of the urinary tract.

Adolescent↗
PubMed1996

Coronary artery bypass graft surgery and its impact on erectile function: a preliminary retrospective study.

Erectile function is markedly affected by acute alterations in circulatory homeostasis of which coronary artery bypass graft surgery is an excellent model. A group of consecutive patients who had undergone coronary artery bypass surgery 6-12 months previously were selected for detailed review by questionnaires that scored their pre-operative and post-operative sexual function and erectile ability and aspects of the quality of life. Thirty patients were evaluable. 10 men (33.3%) had poor erectile function before surgery. Eleven out of 30 men reported an improvement in erectile function while 10 men experienced a decrease or cessation of erectile function. Four of the five patients reporting new post-operative erectile function had had good pre-operative function suggesting that the surgery was directly associated with the impotence in these men. This pilot study suggests that coronary artery bypass surgery can have a significant impact in erectile function.

Coronary Artery Bypass↗
PubMed1995

Outbreaks of foodborne infectious intestinal disease in England and Wales: 1992 and 1993.

We have analysed data from the surveillance scheme of general foodborne outbreaks of infectious intestinal disease in England and Wales reported to, or otherwise identified by, the PHLS Communicable Disease Surveillance Centre in 1992 and 1993. Data were available about 458 outbreaks, 197 (43%) in commercial catering premises (restaurants, cafés, hotels, public houses, and canteens), 77 (17%) associated with food prepared in private houses, and 58 (13%) in hospitals and residential institutions. Salmonellas and Clostridium perfringens were responsible for 340 outbreaks (74%) and no pathogen was identified in 55 outbreaks (12%). Organisms associated with the highest mean attack rates were Staphylococcus aureus (66%) and C. perfringens (53%). Eleven thousand people were reported to be il and 362 were admitted to hospital. There were 15 deaths, 13 of which were associated with salmonellosis. A specified food was suspected to be the vehicle of infection in 204 outbreaks (45%). Possible contributory factors were identified in 277 (61%), most commonly inappropriate storage, cross contamination, and inadequate heat treatment. Reducing the incidence of food poisoning will depend on concerted action on farms, in abattoirs and food processing plants, in wholesale and retail outlets, and in kitchens.

Disease Outbreaks↗