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Biomedical subjects

J Wilkinson

Publications and source records attributed to J Wilkinson.

At least 145 records · Page 8Linked to original sources
PubMed1993

What's in general practice annual reports?

All general practices in the United Kingdom are now required to produce an annual report. This paper reports on the analysis of reports in one Family Health Services Authority's area. The reports varied considerably in content, and many of the data were already in the possession of the FHSA for other purposes. The reports lack a clear purpose. Little or no information could be gleaned on the health of the practice population; in particular, morbidity data were absent from the majority of reports. The report mechanism is potentially a useful process, but needs to be further developed with the profession to gain maximum benefit from the process. The changes in the requirements as a result of the new health promotion regulations are a move in the right direction and remedy some of the problems identified in this paper, but the role of the annual report still remains unclear.

Annual Reports as Topic↗
PubMed1993

Nitric oxide production is inhibited in trauma patients.

Elevated levels of nitrates/nitrites, the stable endproducts of nitric oxide (NO), were recently observed in septic patients. In this setting, NO maintains blood flow by vasodilation and inhibition of platelet aggregation. Trauma patients were found to have low plasma levels of nitrates/nitrites, even when they developed sepsis. The current study substantiated that trauma patients have suppressed production of NO; reductions in plasma nitrate/nitrite levels correlated with low urinary excretion of these endproducts. Nitric oxide production was upregulated in trauma patients with clinical infection compared with trauma patients without infection, but was still significantly suppressed compared with nitric oxide production in normal controls. The inability of trauma patients to produce NO may be an important component of the susceptibility of these patients to infection.

Adolescent↗
PubMed1993

Placental transfer and foetal disposition of caffeine and its immediate metabolites in the 20-day pregnant rat: function of dose.

1. The dispositions of caffeine and its immediate dimethylxanthine metabolites, theobromine, theophylline and paraxanthine were studied after a single oral dose of 5 and 25 mg/kg caffeine administered to 20-day pregnant and non-pregnant rats, respectively. 2. Peak plasma levels were reached between 1 and 3 h in all fluids and tissues studied. 3. The elimination phase, however, differed significantly between the pregnant and non-pregnant groups. For 25 mg/kg the plasma half-life (t1/2) of caffeine was significantly longer in the pregnant than the non-pregnant group; for 5 mg/kg the elimination rate of caffeine was similar in both groups. 4. AUC values were used to compare caffeine and metabolite exposure in foetal tissues. At 5 mg/kg, peak concentrations for amniotic fluid, foetal blood, liver and kidney were not significantly different from one another. At 25 mg/kg peak levels in foetal liver and kidney were significantly less than those of foetal blood, amniotic fluid or placenta. 5. Because of the observed increase in maternal t1/2 at high dosage, a cautionary note is sounded about caffeine intake in pregnancy.

Amniotic Fluid↗
PubMed1993

Topography of apolipoprotein B in subcellular fractions of rabbit liver probed with a panel of monoclonal antibodies.

We have used a panel of anti-rabbit apolipoprotein B monoclonal antibodies in a competitive ELISA to probe the availability of apoB in rough endoplasmic reticulum, smooth endoplasmic reticulum, cis-enriched Golgi, and trans-enriched Golgi fractions from rabbit liver. The ability of each subcellular fraction to inhibit binding of monoclonal antibody to immobilized low density lipoprotein (LDL)-apoB was determined and compared with the expected inhibition based on the apoB content of the fraction. The vesicles remained closed during ELISA, demonstrated by monitoring loss of radiolabeled secretory proteins from the lumen and by measuring leakage of albumin from the vesicles. In control experiments, vesicles were permeabilized using 0.4% taurocholate. All epitopes of apoB were fully expressed in closed trans-Golgi vesicles, indicating that the membrane-bound apoB is at the cytosolic side of this fraction. In the smooth endoplasmic reticulum the epitopes were expressed between 55 and 70%, suggesting that the two pools of apoB may exist in these membranes. These results suggest that newly synthesized apoB has two possible fates. It may be incorporated into the cytosolic side of the endoplasmic reticulum from where it moves to the cytosolic side of the Golgi membrane, or newly synthesized apoB may be translocated to the lumenal surface of the endoplasmic reticulum membrane followed by assembly with lipids for secretion.

Animals↗
PubMed1993

Radiofrequency catheter ablation of tachyarrhythmias--adult and paediatric experience.

BACKGROUND AND AIMS: Until recently, curative therapy for supraventricular tachycardia (SVT) was possible only with map-guided cardiac surgery. The ability to ablate permanently the reentrant circuit responsible for tachycardia using radiofrequency electrical current (RF) delivered through a catheter has now allowed cure of SVT by non-surgical means. We present our initial experience with this technique in both adult and paediatric patients. METHODS: In 53 patients of median age 32 years, 56 radiofrequency catheter ablation procedures were performed for control of tachyarrhythmias. Fourteen patients were aged 18 years or less. Indications for RF ablation were SVT due to an accessory pathway (n = 27), SVT due to atrioventricular junctional reentry (AVJRT) (n = 22), incessant SVT (n = 2), ventricular tachycardia (n = 2), and uncontrolled atrial fibrillation (n = 3). General anaesthesia was used in 88% of procedures. Ablation was preceded by electrophysiological testing to confirm tachycardia mechanism in all cases. RESULTS: The ablation procedure was completely successful in 49/56 cases (87.5%) and partially successful in another two cases. Only five procedures (9%) failed. Median procedure time was two hours, median fluoroscopy time was 24 min, and the median number of RF applications was four. There were no major differences in results comparing adult and paediatric patients. A transient ulnar nerve palsy was the only major complication observed. After a follow-up of one to 15 months, tachycardia has recurred in two patients (4%). Of the total 53 patients, 90.5% are currently asymptomatic and off all cardiac drug therapy. RF catheter ablation appears to be an effective, curative, and relatively safe alternative to long term drug therapy in the management of troublesome SVT.

Adolescent↗
PubMed1992

Determination of the intracellular distribution and pool sizes of apolipoprotein B in rabbit liver.

We have investigated the intracellular distribution of apolipoprotein B (apo B) in rabbit liver by immunoblotting, radioimmunoassay (r.i.a.) and enzyme-linked immunoassay (e.l.i.s.a.). Apo B100 was detected in total microsomes, rough microsomes, smooth microsomes, trans-enriched Golgi and cis-enriched Golgi and membrane and cisternal-content subfractions prepared from these fractions. There was also evidence of degradation of apo B100 in the Golgi membrane fractions. The amount of apo B in the subcellular fractions detected by competitive r.i.a. or e.l.i.s.a. ranged from 1.5 micrograms/mg of protein in the rough endoplasmic reticulum to 13 micrograms/mg of protein in the trans-Golgi fraction. Using internal standards (NADPH-cytochrome c reductase for the endoplasmic reticulum and galactosyltransferase for the Golgi membranes) it was calculated that all the apo B of liver is recovered within the secretory compartment, with 63% of the total apo B in the endoplasmic reticulum and the remainder in the Golgi. When the subcellular fractions were separated into membranes and cisternal contents, 60%, 50%, 60% and 30% of the total apo B was recovered in the membrane of the rough microsomes, smooth microsomes, cis-Golgi and trans-Golgi respectively. Using competitive e.l.i.s.a. we found that the membrane-bound form of the apo B was exposed at the cytosolic surface of the intact subcellular fractions. These observations are consistent with a model for assembly of very-low-density lipoproteins (VLDL) in which newly synthesized apo B is incorporated into a membrane-bound pool and a lumenal pool. The membrane-bound pool not used for VLDL assembly may be degraded, possibly in the Golgi region.

Animals↗
PubMed1992

Membrane-bound apolipoprotein B is exposed at the cytosolic surface of liver microsomes.

We have used a competitive enzyme-linked immunoassay with a panel of monoclonal antibodies to probe the topography of the membrane-bound form of apolipoprotein B (apo B) in rabbit microsomes. All epitopes investigated were found to be expressed at the cytosolic side of the microsomal membrane under conditions in which the vesicles remained sealed. These results indicate that the membrane-associated form of apolipoprotein B is either at the cytosolic side of the endoplasmic reticulum membrane or integrated into the membrane. From this site apo B may be translocated to the lumen for assembly into VLDL or may be degraded.

Animals↗
PubMed1992

Dimensions of anger-hostility and cardiovascular reactivity in provoked and angered men.

This study investigated the relationship between two dimensions of anger-hostility--the expression of anger-hostility and the experience of anger-hostility--and cardiovascular reactivity in provoked and angered men. A serial subtraction task was administered to 41 male undergraduates who were provoked and angered. A measure of the expression of anger-hostility correlated positively and significantly with systolic and diastolic blood pressure (BP) reactivity. There were no significant correlations between a measure of the experience of anger-hostility and cardiovascular reactivity. The two types of anger-hostility were also found to relate differentially to life-style variables that have been identified as risk factors for coronary heart disease (CHD), with only the expression of anger-hostility showing positive relationships with these life-style CHD risk factors. These findings are discussed within the context of a similar differential relationship between the two dimensions of anger-hostility and CAD and CHD. Finally, significant negative relationships were obtained between the experience of anger-hostility and resting BP and heart rate levels. These findings are discussed within the context of other data suggesting that trait anxiety-neuroticism may have protective properties.

Adult↗
PubMed1992

Appropriate acid suppression for the management of gastro-oesophageal reflux disease.

Gastro-oesophageal reflux disease (GORD) results from an abnormally prolonged dwell time of acidic gastric contents in the oesophagus. Although GORD is primarily a motor disorder, the injurious effects of gastric acid are central to the pathogenic process of oesophagitis, and the severity of disease correlates with the degree and duration of oesophageal acid exposure. In the majority of patients with mild disease, oesophageal acid exposure occurs predominantly during post-prandial periods. Conventional doses of H2-receptor antagonists cannot overcome the integrated stimulus to acid secretion resulting from a meal, and are thus relatively ineffective in preventing daytime, post-prandial oesophageal acid exposure. In patients with more severe grades of oesophagitis, there are abnormally high levels of nocturnal acid exposure, with the intra-oesophageal pH being less than 4.0 for 36% of the time, compared with 5% of the time in patients with mild GORD. Control of nocturnal acid secretion thus becomes increasingly important. This may be made worse by relative gastric acid hypersecretion in some patients with severe GORD. The long duration of action and effective inhibition of meal-stimulated acid secretion probably explains the superiority of omeprazole in treating GORD. Preliminary meta-analysis shows that the healing rate of erosive oesophagitis at 8 weeks by antisecretory agents is directly related to the duration of suppression of gastric acid secretion achieved over a 24-hour period (r = 0.87; p less than 0.05).

Anti-Ulcer Agents↗
PubMed1992

Influence of bovine somatotropin on the composition and manufacturing properties of milk.

Three studies (84, 140, and 200 d) were performed to examine the effect of injecting dairy cows with various doses (0, 320, 640, or 960 mg/28 d; 0 or 640 mg/28 d; 0, 320 mg/14 d, or 320 or 640 mg/28 d) of bST on milk production, composition, and manufacturing properties. Mean bST response among studies on milk production varied from 0 (trial 1) to 7.3% (trial 2) and from 8.5 to 14.2% (trial 3) in relation to feeding conditions. Neither milk fat nor protein percentages in milk at time of maximum response were affected by the use of bST. Distribution of casein and protein in the whey was not affected by the treatments at any time. The nature of fatty acids varied more with time after injection than with bST doses. Neither coagulation time, standard curd firmness, nor soft or pressed cheese yields were affected by the treatments.

Animals↗
PubMed1992

The use of exit interviews in health service facilities.

Exit Interviews, also known as termination or separation interviews, are conducted in some hospitals and other health service agencies as a routine procedure when staff are ending their period of employment. The major purpose of these interviews is to elicit data regarding the employee's working experience in the organization and hence identify those factors that enhance retention of staff, for example, job satisfaction, study opportunity, challenging milieu, and those that are contributory factors to the decision to resign, such as, dissatisfaction due to poor standards of care becoming the norm and lack of autonomy in planning and implementing nursing care. As a recent study indicated, the hierarchical level of the Exit Interviewer could have a significant effect on the amount and accuracy of the data so obtained. While applicable to all departments of a facility, comments herein are largely concerned with nursing and are based on a thesis by the author.

Humans↗
PubMed1992

Sequential treatment with low dose almitrine bismesylate in hypoxaemic chronic obstructive airways disease.

Daily dose schedules of 100-200 mg of almitrine bismesylate improve arterial blood gases in patients with hypoxaemic chronic obstructive airways disease (COPD) but dose related side effects are evident. In the present study, daily doses approximately half of those previously used were employed in a randomised double blind manner in 85 patients (age 35-79 years) with hypoxaemic COPD. After a one month period to check stability of arterial blood gases, patients were allocated to almitrine (A) or placebo (P) using an unequal code (60% A, 40% P). Tablets, 50-100 mg daily were stopped for one month after 3, 6 and 9 months to counteract drug accumulation. 50 patients in group A and 35 in group P were comparable on entry; mean age 65 (SD = 8) yrs., Pao2 7.8 (0.7) kPa (58.3 (5.0) mmHg), PaCO2 5.8 (0.8) kPa (43.2 (6.0) mmHg), forced expiratory volume in one second--FEV1 0.89 (0.25) l and 6 minute walking distance 296 (97) metres. The improvement in baseline PaO2 values was the same 0.8-1.3 kPa (6-9.8 mmHg) as with previous higher dose therapy. Approximately one third of patients did not respond, defined as PaO2 elevation > 0.67 kPa (5 mmHg). The sequential dosing scheme stabilised blood levels of almitrine within the therapeutic range of 280-300 ng.ml-1. After withdrawal of therapy arterial blood gases and spirometry reverted to pre-treatment levels, suggesting no permanent reversal of pathophysiology. Dose related side effects of breathlessness, indigestion and peripheral neuropathy were not observed. Nerve conduction studies revealed no difference in peripheral nerve dysfunction in hypoxaemic COPD between active and placebo therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗