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Biomedical subjects

C Thomas

Publications and source records attributed to C Thomas.

At least 37 records · Page 2Linked to original sources
PubMed2005

Oxygen uptake response to an 800-m running race.

We tested the hypothesis that time course of O (2) uptake (VO (2)) measured during a supramaximal exercise performed in the field is driven to maximal oxygen uptake (VO (2max)). On an outdoor track, five middle-distance male runners first performed a test to determine VO (2max) and a supramaximal 800-m running test at least two days apart. VO (2) response was measured from the start to the end of exercise with the use of a miniaturised telemetric gas exchange system (Cosmed K4). VO (2max) was reached by all subjects 45 +/- 11 s (mean +/- SD) after the onset of the 800-m race (i.e., 316 +/- 75 m), and was maintained during the next 33 +/- 6 s (i.e., 219 +/- 41 m). The mean relative exercise intensity of the 800 m was 120 % VO (2max). An unexpected significant decrease in VO (2) (24.1 +/- 7.0 %; p < 0.05) was observed in all subjects during the final 38 +/- 17 s (i.e., the last 265 +/- 104 m). We concluded that, at onset of a simulated 800 m running event, VO (2) is quickly projected towards the VO (2max), and then becomes limited by the achievable VO (2max). This race profile shown by all athletes is in some contrast to what can be expected from earlier findings in a laboratory setting.

Adult↗
PubMed2005

Calcium scoring of aortic valve calcification in aortic valve stenosis with a multislice computed tomography scanner: non-enhanced versus contrast-enhanced studies.

PURPOSE: Previous studies have shown a positive correlation between amount of aortic valve calcification (AVC) and degree of aortic valve stenosis (AVS). We have investigated whether calcium scoring of AVC from contrast-enhanced images is reliable. MATERIAL AND METHODS: Nineteen patients with suspected AVS underwent retrospectively ECG-gated multislice computed tomography (MSCT). Standardized scan protocols were applied prior to (120 KV, 133 mAseff) and after (120 KV, 500 mAseff) the administration of non-ionic contrast material. Image reconstruction was performed at 60% of the RR interval (slice thickness 3 mm, reconstruction increment 2 mm). AVC was quantified using Agatston score and calcium mass. The number of lesions was calculated. All nonenhanced images were scored using thresholds of 130 HU and 350 HU. Contrast-enhanced images were assessed with a threshold of 350 HU exclusively. RESULTS: Fifteen patients with AVCs were included in the statistical analysis. The mean Agatston score (calcium mass) in non-enhanced images was 2888.4 +/- 2844.4 (694.2 mg +/- 869.3 mg). Altering the threshold from 130 HU to 350 HU led to a 58.2% (30.5%) decrease in the AVC score (P values < 0.001). Contrast-enhanced images showed an increased Agatston score (calcium mass) of 56.2% (33.5%) compared to non-enhanced images (P values <0.05) with the same threshold of 350 HU. CONCLUSION: Quantification of AVC from contrast-enhanced images is not reliable, as contrast material simulates calcification.

Aortic Valve↗
PubMed2005

Use of the CRABEL Score for improving surgical case-note quality.

INTRODUCTION: Quality assurance of medical record keeping in general surgery is facilitated by use of the CRABEL Score. Critical appraisal and constant feedback to staff plays an important part in improving case-note quality. MATERIALS AND METHODS: For each case-note audit, a house officer reviewed two sets of case notes for each of six consultant surgeons. Scores were awarded according to initial clerking, subsequent entries, consent, and discharge summary. Overall scores were derived by subtracting deductions for omissions in each category from a starting score of 100. A larger number of points deducted due to absent data leads to a lower overall score and indicates poorer quality case notes. After four audits, a clerking proforma specifically designed to address some of the common areas of weakness identified in our record keeping was introduced and a further audit was performed in March 2004 to assess its impact. RESULTS: The mean score was lowest in the September 2001 audit and improved over the next two audits. However, there was a small reduction in September 2003 compared to September 2002. When the individual sections of the score were looked at separately, the greatest contribution to a poor score comes from the 'subsequent entries' section since there are five entries scored individually leading to a cumulative effect on the overall score. Within both the 'initial clerking' and 'subsequent entries' sections, early audits showed poor performance across a range of areas but consistent poor implementation of the guidelines was seen in a small number of specific areas as record keeping improved. The quality of medical notes improved over the first three cycles but the improvement was not maintained subsequently. DISCUSSION: The CRABEL score has been shown to be a useful, reproducible and easy-to-perform objective assessment of the quality of medical record keeping. Repeated audit cycles have ensured that case-note quality remains a high priority and have also led to the development of standardised admission documentation. Introduction of the latter has led to a measurable improvement in medical record keeping.

England↗
PubMed2005

Ferroportin is expressed on the mucous granule membrane of a subpopulation of goblet cells in the duodenum of the rat.

Ferroportin is a basolateral transporter involved in the release of iron from cells. In addition to expression on the basolateral membrane of enterocytes, ferroportin is also seen on the microvillus membrane. This led us to consider that ferroportin might be expressed by other cells of the intestine where it contributes to iron metabolism. Ferroportin gene and protein expression in rat duodenum was studied by in situ hybridisation and immunohistochemistry, respectively in rats with different efficiencies of iron absorption. Ferroportin mRNA localised to enterocytes of the villus only. Ferroportin was demonstrated in enterocytes and in 30% of goblet cells. In goblet cells it localised to the mucous granule membrane. In iron-loaded intestine some goblet cells contained iron suggesting that ferroportin may transport iron into the mucous granule where it would be lost during discharge of mucous. The finding of ferroportin in iron deficient goblet cells also suggests an additional role to iron excretion.

Animals↗
PubMed2005

The control of hypertension by use of coconut water and mauby: two tropical food drinks.

In this study, the authors investigated the effect of regular consumption of two tropical food drinks, coconut (Cocos nucifera) water and mauby (Colubrina arborescens), on the control of hypertension. Twenty-eight hypertensive subjects were assigned to four equal groups and their systolic and diastolic blood pressures recorded for two weeks before and then for another two weeks while receiving one of four interventions. One group (the control) received bottled drinking water, the second group received coconut water, the third received mauby and the fourth group, a mixture of coconut water and mauby. Significant decreases in the mean systolic blood pressure were observed for 71%, 40% and 43% respectively of the groups receiving the coconut water, mauby and the mixture (p < or = 0.05). For these groups, the respective proportions showing significant decreases in the mean diastolic pressure were 29%, 40% and 57%. For the group receiving the mixture, the largest decreases in mean systolic and mean diastolic pressure were 24 mmHg and 15 mmHg respectively; these were approximately double the largest values seen with the single interventions.

Beverages↗
PubMed2005

The use and control of heel prick blood samples.

The human body is assuming new meanings and value. When tissue, such as hair, blood and saliva is subjected to DNA analysis, detailed intimate information can be revealed about a person that may predict information about behavioural traits and future disorders. Such genetic information may lead to the development of beneficial therapeutic treatments, but it may also lead to employment or insurance discrimination. Human tissue is commonly used by law enforcement agencies to detect perpetrators of crimes and to identify corpses. There are many sources of such tissue samples. One is from samples routinely collected from newborn babies for a test known as the "Guthrie test" or heel prick test. At about two days of age the child's heel is pricked and the resultant drops of blood are applied to filter paper attached to a test card. This is dried and analysed and, in New Zealand, the cards are stored indefinitely. The potential range of research purposes using such blood samples is increasing, and expanding markets have increased their value. This paper considers the status of the samples in light of recent developments in New Zealand and suggests appropriate approaches for retention and further use of the samples, or third party access to them.

Blood Specimen Collection↗
PubMed2004

Monocarboxylate transporters, blood lactate removal after supramaximal exercise, and fatigue indexes in humans.

The present study investigated whether muscular monocarboxylate transporter (MCT) 1 and 4 contents are related to the blood lactate removal after supramaximal exercise, fatigue indexes measured during different supramaximal exercises, and muscle oxidative parameters in 15 humans with different training status. Lactate recovery curves were obtained after a 1-min all-out exercise. A biexponential time function was then used to determine the velocity constant of the slow phase (gamma(2)), which denoted the blood lactate removal ability. Fatigue indexes were calculated during 1-min all-out (FI(AO)) and repeated 10-s (FI(Sprint)) cycling sprints. Biopsies were taken from the vastus lateralis muscle. MCT1 and MCT4 contents were quantified by Western blots, and maximal muscle oxidative capacity (V(max)) was evaluated with pyruvate + malate and glutamate + malate as substrates. The results showed that the blood lactate removal ability (i.e., gamma(2)) after a 1-min all-out test was significantly related to MCT1 content (r = 0.70, P < 0.01) but not to MCT4 (r = 0.50, P > 0.05). However, greater MCT1 and MCT4 contents were negatively related with a reduction of blood lactate concentration at the end of 1-min all-out exercise (r = -0.56, and r = -0.61, P < 0.05, respectively). Among skeletal muscle oxidative indexes, we only found a relationship between MCT1 and glutamate + malate V(max) (r = 0.63, P < 0.05). Furthermore, MCT1 content, but not MCT4, was inversely related to FI(AO) (r = -0.54, P < 0.05) and FI(Sprint) (r = -0.58, P < 0.05). We concluded that skeletal muscle MCT1 expression was associated with the velocity constant of net blood lactate removal after a 1-min all-out test and with the fatigue indexes. It is proposed that MCT1 expression may be important for blood lactate removal after supramaximal exercise based on the existence of lactate shuttles and, in turn, in favor of a better tolerance to muscle fatigue.

Adult↗
PubMed2004

Relationships between maximal muscle oxidative capacity and blood lactate removal after supramaximal exercise and fatigue indexes in humans.

The present study investigated whether blood lactate removal after supramaximal exercise and fatigue indexes measured during continuous and intermittent supramaximal exercises are related to the maximal muscle oxidative capacity in humans with different training status. Lactate recovery curves were obtained after a 1-min all-out exercise. A biexponential time function was then used to determine the velocity constant of the slow phase (gamma(2)), which denoted the blood lactate removal ability. Fatigue indexes were calculated during all-out (FI(AO)) and repeated 10-s cycling sprints (FI(Sprint)). Biopsies were taken from the vastus lateralis muscle, and maximal ADP-stimulated mitochondrial respiration (V(max)) was evaluated in an oxygraph cell on saponin-permeabilized muscle fibers with pyruvate + malate and glutamate + malate as substrates. Significant relationships were found between gamma(2) and pyruvate + malate V(max) (r = 0.60, P < 0.05), gamma(2) and glutamate + malate V(max) (r = 0.66, P < 0.01), and gamma(2) and citrate synthase activity (r = 0.76, P < 0.01). In addition, gamma(2), glutamate + malate V(max), and pyruvate + malate V(max) were related to FI(AO) (gamma(2) - FI(AO): r = 0.85; P < 0.01; glutamate + malate V(max) - FI(AO): r = 0.70, P < 0.01; and pyruvate + malate V(max) - FI(AO): r = 0.63, P < 0.01) and FI(Sprint) (gamma(2) - FI(Sprint): r = 0.74, P < 0.01; glutamate + malate V(max) - FI(Sprint): r = 0.64, P < 0.01; and pyruvate + malate V(max) - FI(Sprint): r = 0.46, P < 0.01). In conclusion, these results suggested that the maximal muscle oxidative capacity was related to blood lactate removal ability after a 1-min all-out test. Moreover, maximal muscle oxidative capacity and blood lactate removal ability were associated with the delay in the fatigue observed during continuous and intermittent supramaximal exercises in well-trained subjects.

Adult↗
PubMed2004

Identification of markers tightly linked to sbm recessive genes for resistance to Pea seed-borne mosaic virus.

Two virus resistance loci on linkage groups II and VI have provided the only sources of natural resistance against Pea seed-borne mosaic virus (PSbMV, Potyviridae) in the important crop plant Pisum sativum L. A combination of parallel approaches was used to collate linked markers, particularly for sbm-1 resistance on linkage group VI. We have identified sequences derived from the genes for the eukaryotic translation initiation factors eIF4E and eIF(iso)4E as being very tightly linked to the resistance gene clusters on linkage groups VI and II, respectively. In particular, no recombinants between sbm-1 and eIF4E were found amongst 500 individuals of an F2 cross between the BC4 resistant line (JI1405) and its recurrent susceptible parent 'Scout'. In a different mapping population, the gene eIF(iso)4E was also shown to be linked to sbm-2 on linkage group II. A parallel cDNA-AFLP comparison of pairs of resistant and susceptible lines also identified an expressed tag marker just 0.7 cM from sbm-1. eIF4E and eIF(iso)4E have been associated with resistance to related viruses in other hosts. This correlation strengthens the use of our markers as valuable tools to assist in breeding multiple virus resistances into peas, and identifies potential targets for resistance gene identification in pea.

Agriculture↗
PubMed2004

Retinoic acid therapy in "degenerative-like" neuro-langerhans cell histiocytosis: a prospective pilot study.

BACKGROUND: Degenerative-like neuro-Langerhans cell histiocytosis (DN-LCH) is a rare complication of LCH marked by progressive cerebellar ataxia. No treatment has so far been shown to slow this progression. PROCEDURE: All-trans retinoic acid (ATRA) was administered orally at a dose of 45 mg/m(2) daily for 6 weeks and then 2 weeks every month for 1 year. The endpoints were clinical status at 1 year (assessed with rating scales for ataxia and disability), adverse effects, and changes in neurological abnormalities on MRI. RESULTS: Ten patients were studied. The treatment was well tolerated. All the patients were clinically stable at the end of the study. No MRI changes were noted. CONCLUSIONS: DN-LCH appeared to be stable during ATRA therapy, but further studies are required to appreciate the possible long-term benefits of ATRA.

Adolescent↗
PubMed2004

A new clinical score for disease activity in Langerhans cell histiocytosis.

OBJECTIVE: To develop an objective tool for assessing disease activity in patients with Langerhans cell histiocytosis (LCH). METHOD: Scoring system was developed and applied to a database containing information on 612 patients. RESULTS: At diagnosis, the score distribution was highly asymmetrical: the score was between 0 and 2 in 74% of cases, 3-6 in 16%, 7-10 in 3%, and more than 10 in 6%. The 5-year mortality rates were 1, 4.4, and 43.4%, respectively, among patients with initial scores of 0-2, 3-6, and >6. Stability or an increase of the score at 6 weeks was highly predictive of death among patients with initial scores above 6, while score stability had no significant impact on vital outcome among patients with low or moderate scores at diagnosis. CONCLUSIONS: This LCH disease activity score provides an objective tool for assessing disease severity, both at diagnosis and during follow-up and treatment.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

[Prognosis of neuroblastoma in childhood. Methods of assessment and clinical use].

Neuroblastoma and its benign counterpart, ganglioneuroma, are pediatric neuroblastic tumors arising in the sympathetic nervous system from neural-crest cells. Neuroblastoma, the most common extra-cranial solid tumour during childhood, is unique for its broad spectrum of clinical virulence from spontaneous remission to rapid and fatal progression despite intensive multimodality therapy. To a large extent, outcome could be predicted by the stage of disease and the age at diagnosis. However, a number of molecular events in neuroblastoma tumors, accounting for the variability of outcome and response to therapy, have been identified over the past decades. Among these, MYCN amplification is the most relevant prognostic factor and was the first genetic marker, in paediatric oncology, to be included in clinical strategies as a guide for therapeutic decision. This has allowed the most suitable intensity of therapy to be delivered according to a risk-stratified strategy, from observation to megadose chemotherapy with stem cell transplantation. Recent advances in understanding the biology and genetics of neuroblastoma will ultimately allow to select poor-risk patients for appropriate future biologically based therapies.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

Delayed primary closure of the burn wounds.

'Early closure' of burn wounds by excising the burned tissues and promptly covering it with skin-grafts or its substitutes within first 'five' post-burns day is a standard technique of burn-wound-management in the burn-units of the "developed" world. But lack of education in general, and health-education in particular amongst the common people in the "developing" countries could hinder acceptance of this procedure. Lack of well-trained and motivated burns-surgeons could worsen the situation. The Sultanate of Oman is one of the developing gulf-countries in the middle-east, where at Khoula hospital, the National Burns-Center in the capital city of Muscat, 'early' surgery was introduced in November 1997 to soon become a routine protocol for burn-wound-management. But delay in getting consent for surgery from unwilling patients or in transferring them from the peripheral hospitals were often the reasons for delaying the burn-wound excision and closure 'beyond 6 days to 11th or 12th' day post-burn. Hence, instead of the term "early", the authors prefer to call it "delayed primary" burn-wound closure because, it still offers "primary intention healing" of the burn-wounds. The aim of this article is to analyze retrospectively the results of the "delayed primary" closure of the burn-wounds done in the Khoula Hospital Burns-Unit of the Sultanate of Oman. During a period of 50 months from November 1997 to December 2001, carefully selected 143 patients out of a total of 592 admissions in burns-unit were subjected to burn-wound excision and auto-skin-grafting (STSG), of whom about 87% patients had "delayed primary" and 13% had "early" surgery. There was no mortality or post-operative morbidity in these operated patients. However, due to the non-availability of skin substitutes the excision and auto-grafting could not be done in extensive burns with inadequate skin-donor-area. The maximum percentage of burns treated by delayed primary surgery (DPS) was 50% in children and 55% in adults. Follow-up results were good functionally as well as cosmetically. The authors conclude that "delayed primary" is the second best alternative to the "early" burn-wound excision and closure with similar advantages of reducing risk of septicemia, mortality, and morbidity, hospital stay and cost of treatment. It should be preferred over "secondary" skin-grafting of granulating wounds. Thus, in the developing countries, the indications of delayed primary burn surgery could be (1) patients unstable or unfit for surgery during the first post-burn week; (2) delay in transferring in the patients; (3) delay in getting patient's consent for surgery; (4) very major burns without availability of skin substitutes; and (5) lack of operating time in a busy burns-unit. The contraindications for delayed primary surgery are any sign of invasive sepsis or organ failure.

Adolescent↗
PubMed2004

Surgical-site infections after orthopaedic surgery: statewide surveillance using linked administrative databases.

Prospective surveillance programmes to monitor the incidence of surgical-site infection (SSI) in patients who have had orthopaedic implant surgery can be difficult to implement due to limited human and technical resources. In addition, prolonged patient follow-up, up to one year, may be required. Traditional methods of surveillance can be enhanced by using administrative databases to assist in case finding and facilitate overall surveillance activities. The aim of this study was to identify the incidence of SSI in patients who had undergone total hip replacement (THR) or total knee replacement (TKR) surgery in all Western Australian (WA) hospitals during 1999 using the Western Australian Data Linkage System. The WA Data Linkage System links several population-based administrative health datasets within the state, including the Hospital Morbidity Data System (HMDS), containing International Classification of Disease-coded discharge information, and mortality records. A total of 1476 THR and 1875 TKR procedures was identified from 21 WA hospitals during 1999. The incidence of SSI after these procedures was 5% (95% CI 4.3-5.7) [THR (4.86%, 95% CI 3.77-5.95) and TKR (5.15%, 95% CI 4.15-6.15)]. The incidence was 33.72 infections per 1000 person-years. Patients aged over 80 years experienced a significantly higher rate of infection after THR compared with patients aged 80 or less (z-test, z = 2.56, P = 0.015), but not for TKR. No patients with an SSI died during follow-up. The WA Data Linkage System provided a unique opportunity to review the incidence of SSIs in patients undergoing THR or TKR surgery in WA hospitals.

Adult↗
PubMed2004

Functional domains and sub-cellular distribution of the Hedgehog transducing protein Smoothened in Drosophila.

The Hedgehog signalling pathway is deployed repeatedly during normal animal development and its inappropriate activity is associated with various tumours in human. The serpentine protein Smoothened (Smo) is essential for cells to respond to the Hedeghog (Hh) signal; oncogenic forms of Smo have been isolated from human basal cell carcinomas. Despite similarities with ligand binding G-protein coupled receptors, the molecular basis of Smo activity and its regulation remains unclear. In non-responding cells, Smo is suppressed by the activity of another multipass membrane spanning protein Ptc, which acts as the Hh receptor. In Drosophila, binding of Hh to Ptc has been shown to cause an accumulation of phosphorylated Smo protein and a concomitant stabilisation of the activated form of the Ci transcription factor. Here, we identify domains essential for Smo activity and investigate the sub-cellular distribution of the wild type protein in vivo. We find that deletion of the amino terminus and the juxtamembrane region of the carboxy terminus of the protein result in the loss of normal Smo activity. Using Green Fluorescent Protein (GFP) and horseradish peroxidase fusion proteins we show that Smo accumulates in the plasma membrane of cells in which Ptc activity is abrogated by Hh but is targeted to the degradative pathway in cells where Ptc is active. We further demonstrate that Smo accumulation is likely to be a cause, rather than a consequence, of Hh signal transduction.

Alleles↗
PubMed2004

Place of death: preferences among cancer patients and their carers.

The place of death of cancer patients has become an important theme in UK cancer and palliative care policy. This paper examines the place of death preferences of 41 terminally ill cancer patients and 18 of their informal carers, living in the Morecambe Bay area of north-west England. We interviewed cancer patients referred to the research team by 13 specialist palliative care professionals; patients had an estimated 3 months of life remaining. The study design involved an in-depth qualitative interview with each patient soon after referral to the study, followed by an interview some 4 weeks later and subsequent tracking interviews by telephone at 2-4 week intervals until death occurred. Interviews were also conducted with main coresident carers soon after patient referral to the study and again in the post-bereavement period. Thirteen factors were identified as shaping the place of death preference of patients and carers. These are organised into four thematic domains: the informal care resource, management of the body, experience of services, and existential perspectives. In documenting these factors, this paper adds significantly to current knowledge on the factors that shape place of death preference, a field of enquiry acknowledged to be underdeveloped (J. Palliative Med. 3 (2000) 287). More importantly, it uncovers some of the reasons that underpin these preferences. Our research revealed a much stronger preference for deaths in a hospice than had been anticipated, leading us to take a qualified stance on the current policy drive in favour of home deaths by those charged with delivering UK cancer and palliative care services.

Adult↗
PubMed2004

Schizophrenia-spectrum psychoses in people with and without intellectual disability.

BACKGROUND: Although there is an increased risk of schizophrenia-spectrum psychoses (SSP) in people with intellectual disability (ID), there is a paucity of research evidence into clinical presentation of the disorder in comparison with research into SSP in people without ID. AIMS: The aims of the study were to compare clinical, functional, and social factors in patients with mild ID (ICD-10: F70) and SSP (ICD-10: F20-9) attending a specialist mental health service for people with ID, with a control group of patients without ID but with SSP attending a generic adult mental health (GAMH) outpatient clinic. METHOD: A total of 106 patients with SSP (53 with ID and 53 from GAMH) were assessed on psychopathological symptoms, functioning scales and quality of life. They were compared using chi-squared and regression analysis where appropriate. RESULTS: People with ID and SSP appear to be more debilitated by the co-occurring disorder than those with the same disorder but without ID. Increases in observable psychopathology and "negative" schizophrenic symptoms, and decreased functional abilities were observed in the group with ID when compared to the GAMH group. The clinical implications of these findings are discussed.

Adult↗