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Biomedical subjects

K Birch

Publications and source records attributed to K Birch.

At least 19 recordsLinked to original sources
PubMed2002

The diurnal rhythm in isometric muscular performance differs with eumenorrheic menstrual cycle phase.

The aim of this study was to examine the effect of the interaction of circamensal and diurnal rhythms in temperature upon the production of maximal voluntary muscle force. Ten eumenorrheic females (mean age: 24 +/- 3 yr mean body mass: 58.4 +/- 6.9 kg) participated in the experiment at both 06:00 and 18:00h at the mid-point of both the follicular and luteal phases of the menstrual cycle. Subjects performed tasks of maximal isometric lifting strength (MILS) at knee height, and endurance time (t) for lifting 45% of MILS, upon an isometric lift dynamometer. Body temperature was elevated at 18:00h and in the luteal phase by 0.52 +/- 0.4 and 0.26 +/- 0.35 degrees C, respectively. The amplitude of the diurnal variation in temperature was blunted by 0.3 degrees C within the luteal phase. Maximal isometric performance was elevated by 8% at 18:00h in the luteal phase of the cycle (p < 0.05 interaction for MILS) but unaffected by time of day in the follicular phase. Endurance time was unaffected by time or phase (p > 0.05). It should be noted that the classic diurnal rhythm in maximal voluntary isometric muscle force may not be evident in all phases of the female menstrual cycle.

Adult↗
PubMed2001

Technical note: repeatability of measurement in determining stature in sitting and standing postures.

The aim of this study was to determine the effect of sitting and standing postures on the repeatability of a stadiometer designed to detect small variations in spinal length. Two groups of ten healthy subjects, with no previous or known history of back problems, participated in this study. One group was measured in the standing posture, while the other group was measured in a sitting posture. All subjects gave informed consent to participate in this study. Subjects had a set of landmarks defining the spinal contour marked on their backs and then stood in the stadiometer for three series of ten measurements to be performed. At the end of each measurement, the subjects were requested to move away from and then be repositioned in the stadiometer. Subjects improved the repeatability across the measurement series. At the end of the second measurement series, all subjects presented mean standard deviations of 0.43 +/- 0.08 mm (range 0.30-0.50 mm) in the standing posture. In the sitting posture, deviations of less than 0.05 mm were obtained only at the end of the third measurement series (0.48 +/- 0.08 mm; range 0.34-0.62 mm), suggesting that this posture required three measurement series before repeatable measurements could be assured rather than two in the standing posture.

Adult↗
PubMed2000

Putting the 'tele' into health-care effectively.

Although the introduction of new technologies has been successful and become accepted practice in many areas of industry, traditional methods have tended to prevail in health-care. Telemedicine has been adopted by enthusiasts who recognize the potential benefits of a 'global health service'. However, the more widespread introduction of telemedicine requires considerable organizational change in the way health-care is delivered. More evaluation is required of clinical outcomes, organizational effects, benefits to health-care providers and users, and quality assurance.

Global Health↗
PubMed2000

The need to ensure that the globalization of information and telematics does not destabilize health-care worldwide.

Modern telecommunication transcends institutional, organizational and cultural boundaries. In the context of health-care, this means that information, enquiries, demands and service provision can be routed anywhere, free of institutional or natural control. The Internet makes information available to anyone regardless of its quality, source or intention. Organizationally initiated applications such as telemedicine are usually intended to reinforce local systems, but their very design and intention indicate a potential rapidly to transcend inherited but electronically ineffectual boundaries. The consequences of such uncontrolled globalization of health-care activities will range from beneficial empowerment and quality improvement, to detrimental effects such as overloading of experts, and undermining of stable health-care systems. The major unplanned societal re-engineering effects in a paper-based culture are likely to be significant and global institutions need to respond by creating positive global frameworks and policies.

Clinical Competence↗
PubMed1997

NHS reforms. Counting the costs.

Localism predominates in purchaser-provider relationships, with markets strictly limited in practice. Block contracting predominates, largely to enable purchasers to bring pressure to bear on providers' costs and outputs. The administrative costs of operating the purchaser-provider split have led to a clear growth in the overall administrative costs within the NHS. Locality commissioning may conflict with the need to reorganise clinical services.

Contract Services↗
PubMed1997

Primary care. Defining role.

There is no nationally agreed definition of nurse practitioners or of the training required. The extent of the need for nurses to take on doctors' work needs to be established. A clear training framework is required.

Health Care Surveys↗
PubMed1996

Changes in maximal voluntary force of human adductor pollicis muscle during the menstrual cycle.

1. Muscle strength of the adductor pollicis (AP) was studied throughout the menstrual cycle to determine whether any variation in force is similar to the known cyclical changes in ovarian hormones. Three groups of young women were studied: trained regularly menstruating athletes (trained), untrained regularly menstruating (untrained) and trained oral contraceptive pill users (OCU). In addition a group of untrained young men was studied as controls. 2. Maximum voluntary force (MVF) of AP was measured over a maximum period of 6 months. Ovulation was detected by luteinizing hormone measurements or change in basal body temperature. There was a significant increase in MVF (about 10%) during the follicular phase of the menstrual cycle when oestrogen levels are rising, in both the trained and untrained groups. This was followed by a similar in MVF around the time of ovulation. Neither the OCU nor the male subjects showed cyclical changes in MVF.

Adolescent↗
PubMed1994

Pharmacokinetics and pharmacodynamics of recombinant factor VIIa.

OBJECTIVE: To evaluate the pharmacokinetics and pharmacodynamics of recombinant activated factor VII (rFVIIa). METHODS: Single-dose pharmacokinetics of three dose levels (17.5, 35, and 70 micrograms/kg) of rFVIIa were investigated in 15 patients with hemophilia with severe factor VIII or factor IX deficiency (with or without inhibitors) while they were in the nonbleeding state and during bleeding episodes. Factor VII clotting activity (FVII:C) was determined 5 minutes before and at 10, 20, and 50 minutes and 2, 4, 6, 8, 12, and 24 hours after rFVIIa administration. Model-independent pharmacokinetic analysis of FVII:C plasma concentration-time data included determination of plasma clearance, mean residence time, and volume of distribution. rFVIIa recovery was determined from the plasma FVII:C observed 10 minutes after administration. Pharmacodynamic assessments of prothrombin time, activated partial thromboplastic time, and Factor X values obtained concurrently with FVII:C samples were performed. RESULTS: Sufficient data to allow pharmacokinetic parameter calculation were available for 25 nonbleeding episodes in 11 patients (17.5 micrograms/kg, n = 8; 35 micrograms/kg, n = 9; 70 micrograms/kg, n = 8) and for five bleeding episodes in three patients (17.5 micrograms/kg, n = 2; 35 micrograms/kg, n = 2; 35 micrograms/kg, n = 1). Recovery was calculated during 27 nonbleeding and 17 bleeding episodes. rFVIIa distribution volume is two to three times that of plasma. Median clearance was low--31.0 ml/hr.kg in nonbleeding episodes and 32.5 mg/hr.kg in bleeding episodes. In nonbleeding episodes, median mean residence time was 3.44 hours and median half-life was 2.89 hours. In bleeding episodes, the elimination rate appears to be higher, with a median mean residence time of 2.97 hours and a median half-life of 2.30 hours. Recovery was 45.6% during nonbleeding conditions and 43.5% during bleeding episodes (p = 0.0006); it was statistically lower with the highest dose level than with the 17.5 and 35 micrograms/kg doses (p = 0.007). A significant statistical relationship was observed between values of the prothrombin time and activated partial thromboplastin time, and values of FVII:C with use of maximum effect model. CONCLUSIONS: The pharmacokinetics of rFVIIa are linear in the dose range evaluated. The results suggest potential value of prothrombin time determination in the monitoring of rFVIIa therapy.

Adolescent↗
PubMed1994

The relation between isometric lifting strength and muscular fitness measures.

The purpose of this study was to construct an isometric lift dynamometer and relate isometric lifting strength to dynamic measures of muscular fitness, leg and back strength and muscular power output. Thirty-one male subjects, aged 19-24 years, performed a standing broad jump (for distance), a vertical jump (for flight time), 3 maximal pulls (for peak power) on a rowing ergometer and maximal isometric leg and back extensions on a conventional dynamometer. The results of these tests were correlated with the maximum isometric lifting strength (MILS) obtained on the lift dynamometer using cluster correlation and multiple regression. Significant correlations (p < 0.001) were found between isometric lifting strength and back strength (BS) (r = 0.59), and leg strength (LS) (r = 0.74). A significant correlation was also noted between isometric lifting strength and both standing broad jump (SBJ) (r = 0.58, p < 0.001) and power output (PO) (r = 0.38, (p < 0.05). Multiple regression analysis was used to predict lifting performance from a battery of standard fitness tests. The prediction equation for maximal isometric lifting strength included the terms LS, BS, SBJ and PO (r = 0.80). The relation between isometric lifting strength and other muscular fitness variables suggest that the method used provides an acceptable measure of strength and an indication of the involvement of back and leg musculature in squat lifting.

Adult↗
PubMed1993

Safety and initial clinical efficacy of three dose levels of recombinant activated factor VII (rFVIIa): results of a phase I study.

The safety and efficacy of recombinant DNA-produced factor VIIa (rFVIIa) was investigated in 15 haemophilic patients in non-bleeding states and during bleeding episodes (mild to moderate joint bleed). Patients with severe haemophilia A without inhibitors (n = 4), haemophilia A with inhibitors (n = 10), and haemophilia B with inhibitor (n = 1) received one or more doses of rFVIIa during 32 non-bleeding study episodes and 23 bleeding episodes. The study was an open, uncontrolled, dose-escalation (17.5 micrograms/kg, 35 micrograms/kg, 70 micrograms/kg) trial. Physical evaluation, laboratory assessment, and immunology testing were conducted at baseline, monthly for 3 months and every 3 months thereafter. The immediate safety of rFVIIa was assessed by monitoring of D-dimer, fibrinogen, platelet count, antithrombin III, thrombin-antithrombin complex, and alpha 2-antiplasmin 5 min before and at multiple times throughout the following 24 h. Prothrombin time (PT) and activated partial thromboplastin time (aPTT) values were also obtained. Pain, swelling, joint circumference, and range of motion were recorded before administration of the initial dose of rFVIIa in bleeding patients and at 6, 12, and 24 h. Haemostatic response to rFVIIa was observed in patients with severe VIII and IX deficiency with and without inhibitors. Therapy with rFVIIa was judged effective in 19 of the 22 evaluable bleeding episodes at one or more time points. The 35 micrograms/kg and 70 micrograms/kg doses were associated with higher response rates at 6 and 12 h compared to the 17.5 micrograms/kg dose level. A second dose of rFVIIa was administered in 20 of the 22 bleeding episodes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Experience with recombinant factor VIIA in an infant hemophiliac with inhibitors to FVIII:C undergoing emergency central line placement. A case report.

An infant boy with severe factor VIII (FVIII) deficiency hemophilia and antibodies against coagulation FVIII is presented. This case is unique from the point of view of the young age of development and recognition of inhibitors to the FVIII and because this patient received recombinant factor VIIa (rFVIIa), prior to a life-saving surgical procedure. Conventional treatment options had been exhausted. The inhibitor was an IgG antibody that had rapidly increased to 100 Bethesda Units (BU). A broviac central line was placed to provide i.v. access for the purpose of treatment. Porcine FVIII had been used but an inhibitor rapidly developed to that product. Using rFVIIa, hemostasis was secured for placement of a second central line and to stop life-threatening mucosal bleeding. rVIIa was an effective treatment alternative for the management of this patient with inhibitors.

Autoantibodies↗
PubMed1990

Endocrine, metabolic and cardiovascular responses to adrenaline after abdominal surgery.

Adrenaline-induced changes in heart rate, blood pressure, plasma adrenaline and noradrenaline, cortisol, glucagon, insulin, cAMP, glucose lactate, glycerol and beta-hydroxybutyrate were studied preoperatively and 4 and 24 h after skin incision in 8 patients undergoing elective cholecystectomy. Late postoperative responses of blood glucose, plasma cAMP, lactate and glycerol to adrenaline infusion were reduced, whereas other responses were unaffected. Blood glucose appearance and disappearance rate as assessed by [3H]3-glucose infusion was unchanged pre- and postoperatively. The increase in glucose appearance rate following adrenaline was similar pre- and postoperatively. These findings suggest that several beta-receptor-mediated responses to adrenaline are reduced after abdominal surgery.

Adult↗
PubMed1988

Random blood glucose sampling as an early antenatal screening test for diabetes mellitus.

Random blood glucose was measured on 1,992 pregnant women during the initial attendance at our antenatal clinic. The visit usually took place during the first part of the second trimester. Women with a random blood glucose concentration in excess of 6.1 mmol/l within 2 hours of the last meal and 5.6 mmol/l more than 2 hours after the last meal were referred for a fasting blood glucose measurement. A 75 g oral glucose tolerance test was performed in those cases where the fasting blood glucose exceeded 4.0 mmol/l. The cut-off levels were exceeded in 22 cases, but only one of these women was found to be suffering from previously unsuspected diabetes mellitus, based on the criteria of WHO (1). Five other cases of gestational diabetes were not detected by the random blood glucose method. It is concluded that random blood glucose measurements cannot be recommended as a safe and reliable screening procedure during the early part of the second trimester.

Adult↗
PubMed1988

Metabolic state does not influence lymphocyte subsets in type 1 diabetic patients.

In most studies the distribution of peripheral lymphocyte subsets at diagnosis of type 1 diabetes has been found to be altered. Lymphocyte subpopulations were therefore studied during longitudinal changes in the glycaemic control of 11 type 1 diabetics to investigate whether poor metabolic status affects these results. To avoid any influence of the etiopathogenetic mechanisms, the patients studied had a disease duration of 10 +/- 2 (SEM) years and all but one had no residual beta-cell function. The patients were selected randomly amongst those with a long record of poor glycaemic control and at the first examination they had a mean fasting blood glucose of 15 +/- 1 mmol/l and a mean glucosuria of 67 +/- 11 g/24 h. They were then hospitalized and strictly regulated using pump treatment, resulting in a massive reduction in glucosuria (0 +/- 0 g/24 h) and fasting blood glucose (6 +/- 1 mmol/l) at a second examination a week later. Five of the patients were tested for a third time 35 +/- 4 days later and were still in very good glycaemic control. Peripheral lymphocytes were labelled with monoclonal antibodies and examined by flow cytometry (FACS). Neither CD3+ (pan) T-lymphocytes, CD4+ (helper) T-cells, CD8+ (suppressor/cytotoxic) T-cells, the relation between CD4+ and CD8+ T-cells, nor the total amount of lymphocytes, changed significantly between the first, second, and third examination. None of the results were significantly different from those of healthy controls. There was no correlation between any of the immunological and metabolic parameters. It is concluded that metabolic influence on the distribution of lymphocyte subsets is unlikely.

Adult↗
PubMed1987

Effect of i.v. lignocaine on pain and the endocrine metabolic responses after surgery.

Pain intensity, and blood glucose and plasma cortisol concentrations were measured following abdominal hysterectomy in 18 patients allocated randomly to receive either i.v. lignocaine 1.5 mg kg-1 plus 2 mg kg-1 h-1, or saline. The administration of lignocaine resulted in plasma concentrations between 1.5 and 2.0 micrograms ml-1 during the 2-h study period. However, the administration of lignocaine i.v. had no effect on the intensity of pain after surgery, or on the adrenocortical and hyperglycaemic responses to surgery.

Adult↗
PubMed1987

Relationship between subcutaneous blood flow and absorption of lente type insulin.

To study the relationship between the absorption of intermediate acting insulin and the local subcutaneous blood flow (SBF) 8 diabetic patients were given subcutaneous injections of 125I labeled human lente type insulin and 133Xenon in the abdominal wall. External measurements of the tracer disappearance were performed and the insulin absorption rate and SBF were calculated. A curvilinear relationship between the insulin absorption rate and SBF was demonstrated with an initial almost linear relation but with decreasing impact of SBF when this was in the higher physiological range.

Absorption↗