Biomedical subjects
J R Thompson
Publications and source records attributed to J R Thompson.
Perspectives in multiple myeloma: survival, prognostic factors and disease complications in a single centre between 1975 and 1988.
One hundred and forty-one patients with multiple myeloma, diagnosed at the City Hospital, Nottingham between January 1975 and October 1986, were followed until death or for at least two years in a retrospective study. Overall median survival was 25 months, with no significant improvement occurring during the study period; increasing age, ESR and serum creatinine concentration at diagnosis were independent predictors of shortened survival. Renal impairment developed in 56 per cent of patients but only 7 per cent died of renal failure. At least one episode of infection occurred in 55 per cent of patients, most commonly in the first month. There was a significant rise in the overall incidence of infection and in the proportion caused by Gram-negative bacteria during the study period. Raised serum urea and low haemoglobin concentrations at diagnosis were independent risk factors for subsequent infection. Infection was associated with 2.75-fold increased risk of death, independent of other risk factors. Prevention of infection is an important aim for improvements in the survival of patients in multiple myeloma.
Comparison of normal saline and heparin solutions for maintenance of arterial catheter patency.
A double-blind, randomized study was conducted in 30 adult medical intensive care unit patients to determine if the presence of heparin in continuous-flush solutions prolongs the functional life span of radial arterial catheters compared with catheters flushed with solutions not containing heparin. Patients were consecutively entered into the study and randomly assigned to receive arterial line flush solutions containing 0.9% sodium chloride (NSS) or heparin 4 U/ml in 0.9% sodium chloride. The flow rate of each flush solution was approximately 3 ml/hr. Use of the heparin-containing flush solution resulted in a catheter survival rate of 86% at 96 hours compared with a rate of only 52% after 40 hours with NSS (p less than 0.05). In addition, the heparin-flushed catheters required significantly less manipulation to prevent catheter occlusion and arterial pressure-wave dampening (p less than 0.01). The use of NSS as a continuous flush for radial artery catheters is associated with an increased frequency of catheter occlusion and malfunctions compared with solution containing heparin, and thus is not recommended in patients with normal coagulation status and platelet count.
Contribution of exogenous substrates to acetyl coenzyme A: measurement by 13C NMR under non-steady-state conditions.
A method is presented for the rapid determination of substrate selection in a manner that is not restricted to conditions of metabolic and isotopic steady state. Competition between several substrates can be assessed directly and continuously in a single experiment, allowing the effect of interventions to be studied. It is shown that a single proton-decoupled 13C NMR spectrum of glutamate provides a direct measure of the contribution of exogenous 13C-labeled substrates to acetyl-CoA without measurement of oxygen consumption and that steady-state conditions need not apply. Two sets of experiments were performed: one in which a metabolic steady state but a non-steady-state 13C distribution was achieved and another in which both metabolism and labeling were not at steady state. In the first group, isolated rat hearts were supplied with [1,2-13C]acetate, [3-13C]lactate, and unlabeled glucose. 13C NMR spectra of extracts from hearts perfused under identical conditions for 5 or 30 min were compared. In spite of significant differences in the spectra, the measured contributions of acetate, lactate, and unlabeled sources to acetyl-CoA were the same. In the second set of experiments, the same group of labeled substrates was used in a regional ischemia model in isolated rabbit hearts to show regional differences in substrate utilization under both metabolic and isotopic non steady state. This sensitive probe of substrate selection was also demonstrated in intact hearts where excellent time resolution (3 min) of substrate selection was feasible.(ABSTRACT TRUNCATED AT 250 WORDS)
The effect of glutamine on protein turnover in chick skeletal muscle in vitro.
The effect of glutamine on the rates of protein synthesis and degradation was studied in isolated chick extensor digitorum communis muscles incubated in the presence of plasma concentrations of amino acids. Addition of 0.5-15 mM-glutamine increases (P less than 0.01) intracellular glutamine concentrations by 31-670%. There is a positive relationship (r = 0.975, P less than 0.01) between intracellular glutamine concentration and the rate of muscle protein synthesis measured by the incorporation of [3H]phenylalanine. The stimulating effect of 15 mM-glutamine on protein synthesis was decreased from 58 to 19% in muscles incubated in the absence of tyrosine. The rates of protein degradation, estimated from [3H]phenylalanine release from muscle proteins prelabelled in vivo, decreased (P less than 0.05) by 15-30% in the presence of 4-15 mM-glutamine when compared with muscles incubated in the presence of physiological concentrations of glutamine (0.5-1 mM). Glutamine concentrations ranging from 2 to 15 mM appear to have an overall anabolic effect on chick skeletal muscles incubated in vitro.
Acute toxoplasmosis in a camel.
A 6-year-old camel was examined because of a history of dyspnea of unknown duration. Approximately 24 L of turbid fluid was drained from the pleural cavity. Numerous Toxoplasma gondii tachyzoites were found in macrophages in smears of the pleural fluid. High titers (1:20,000) of T gondii antibodies were found in pleural fluid.
The effect of ketone bodies on protein turnover in isolated skeletal muscle from the fed and fasted chick.
1. The addition of 4 mM acetoacetate or DL-beta-hydroxybutyrate to the incubation medium decreased the rate of protein synthesis without influencing the rate of protein degradation in extensor digitorum communis (EDC) muscles from fed chicks and decreased the rates of protein synthesis and degradation in muscles from fasted chicks. 2. Ketone bodies markedly decreased intracellular concentrations of glutamine in EDC muscles from fed chicks by increasing glutamine oxidation. 3. The addition of 0.5 mM glutamine to incubation media containing 1.0 mM glutamine reversed the ketone body-induced decrease in intracellular glutamine concentration to the control value and blocked the inhibiting effect of ketone bodies on protein synthesis in skeletal muscles from fed chicks. 4. The addition of 5 mM pyruvate blocked the ability of ketone bodies to increase glutamine oxidation and prevented the associated decrease in intracellular glutamine concentration and the rate of protein synthesis in EDC muscles from fed chicks. 5. These results suggest that ketone bodies can act directly on skeletal muscle to inhibit the rate of protein synthesis in muscles from fed chicks by decreasing intracellular glutamine concentration by increasing its oxidation.
Protective effect of KCl loading in gentamicin nephrotoxicity.
Aminoglycoside nephrotoxicity in experimental animals can be reduced by calcium loading, inducing diabetes, and giving thyroid hormone, while a potassium deficient diet enhances aminoglycoside nephrotoxicity. This study investigated whether potassium loading protects against gentamicin nephrotoxicity in the rat. In part I, group GK ate a diet containing 3.5% potassium and drank 0.2 mol/L KCl. Pair-fed rats eating a standard diet, group G, ate a 1% potassium diet and drank water. After 10 days, each group received gentamicin subcutaneously, 60 mg/kg twice daily for 8 days. The control groups, K and C, received the high or normal potassium diet, respectively. To control for a protective effect from a high solute load, the effect of equimolar NaCl loading was studied in group GNa and Na. At the end of the 8 days of gentamicin, inulin clearance was significantly higher in GK compared with G(0.6 +/- 0.1 v 0.3 +/- 0.1 mL/min per 100 g body weight [BW], P less than 0.05), but group GNa (0.4 +/- 0.1 mL/min per 100 g BW) was not different from group G. Morphological studies demonstrated that potassium-loaded rats (group GK) had significantly less proximal tubular necrosis compared with rats on a standard potassium diet, group G. Sodium loading did not protect against cellular necrosis. Part II studied renal function, cortical Na,K-adenosine triphosphatase (ATPase) and gentamicin accumulation after 2 days of gentamicin to determine the early functional and biochemical effects of potassium loading before overt renal functional impairment.(ABSTRACT TRUNCATED AT 250 WORDS)
The prevalence of age related cataract in the Asian community in Leicester: a community based study.
A community based ophthalmic survey has been carried out in the city of Leicester. Samples of Asians and Caucasians aged 40 years and over were randomly selected from the patients of four general practitioners and invited to have an ophthalmic examination. After adjustment for age, the prevalence rate of age-related cataract was significantly higher in the Asians when compared to the Caucasians. Age-related cataract was found to develop earlier in the Asians. A strict vegetarian diet was found to be a significant risk factor for age-related cataract in the Asian Community in Leicester.
Ultrasound assessment of renal cortical brightness in infants: is naked eye evaluation reliable?
Twenty observers estimated renal cortical brightness compared with the liver in 28 ultrasound images. Their judgment was compared with objective densitometer readings. High inter- and intra-observer variation was found. Estimates of brightness of ultrasound images by eye alone should be interpreted with care.
A survey of the initial referral of children to an ophthalmology department.
We report on a survey of the referral of 525 children making their first visit to an ophthalmology department. Information was gathered by interviewing the parents and reviewing the case notes. Parents and relatives initiated the referrals in 223 cases (42%) and health visitors initiated a further 123 cases (23%). General practitioners were rarely the first to notice a condition, though they played a major part in the subsequent referral process. Of 556 reasons for referral squint was the most important (319 cases, 57%), followed by poor vision (106 cases, 19%). There were 44 confirmed cases of amblyopia, of which 15 (34%) were not detected until the child was aged 5 years or over. The overall accuracy of referral was 66% (367 reasons for referral confirmed). In 109 cases (21%) the child was found to be normal. Parents and relatives first noticed 54% of cases of confirmed squint but only 15% of the cases of poor vision. Health professionals, especially health visitors, were of great importance in first detecting poor vision.
Sequential and simultaneous "in series" hemodialysis and hemoperfusion in the management of theophylline intoxication.
Hemodialysis and hemoperfusion have been evaluated, and both are effective in removing theophylline. We report two consecutive cases of theophylline intoxication in which the sequential treatment of charcoal hemoperfusion and hemodialysis is contrasted to the simultaneous "in series" treatment of hemodialysis and charcoal hemoperfusion. Analysis of the two methodologies shows that the combined in series technique offers several advantages, including increased extraction efficiency, decreased time of hemoperfusion cartridge saturation, and rapid correction of electrolyte and acid-base abnormalities, and that it is well tolerated clinically. Simultaneous hemodialysis and charcoal hemoperfusion should be considered in cases of extreme theophylline intoxication.
Scanning tunneling microscopy and spectroscopy of plasmid DNA.
We present scanning tunneling microscope (STM) images of uncoated deoxyribonucleic acid (DNA) electrochemically mounted on highly-oriented pyrolytic graphite (HOPG) and imaged in air. Images of linear abnormalities inherent to HOPG surfaces that can be confused with DNA are also presented. Scanning tunneling spectroscopic (STS) images generated by superimposing a small, high frequency ac bias onto the dc tunnel bias and recording the ac current signal were taken simultaneously with the topographic images. These spectroscopic images reveal contrast due to local conductivity variations and can be used to differentiate DNA molecules from graphite artifacts.
The 1989 Kentucky Hospital Smoking Policy Survey.
Kentucky leads the nation in percentage of smokers (32.5%), years of potential life lost due to smoking-related illness, and burley tobacco production. In view of this, we sought to determine current practice regarding smoking policies in Kentucky hospitals. Acute care and psychiatric hospitals were identified through the 1988 Kentucky Hospital Association Directory and the Paired Community Laboratory System. One hundred seven institutions were sent standardized questionnaires. An additional 16 hospitals were contacted by phone only. All mail and telephone surveys were directed towards the institution's president, administrative director, or CEO. Eighty-one (75.7%) of those contacted by mail responded to the survey. The 26 non-responding institutions were then contacted through a telephone survey. Thus, 100% of acute care hospitals in Kentucky participated in the survey. Of the 123 institutions surveyed, 110 (89.4%) have some type of smoking policy. Of those 110 hospitals with smoking policies, only 6 totally prohibited smoking on the premises. The 13 hospitals without any form of policy were queried about future plans for smoking policies. Of these, only 4 had no plans to work on a hospital smoking policy. Of the 123 hospitals surveyed, 100 do not sell tobacco products. There were no statistically significant differences between the numbers of beds, average length of stay, occupancy rate, or county populations in Kentucky hospitals that do not sell tobacco versus those hospitals that do sell tobacco.(ABSTRACT TRUNCATED AT 250 WORDS)
Home intravenous diuretic therapy for patient with refractory heart failure.
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Is methionine transaminated in skeletal muscle?
Methionine transamination is extensive in rat and chick skeletal-muscle homogenates, but is barely detectable in intact rat, but not chick, skeletal muscles. Branched-chain amino acids essentially block methionine transamination in intact muscles and homogenates from both species. The physiological significance of methionine transamination in skeletal muscle is questioned.
Formation of alanine and glutamine in chick (Gallus domesticus) skeletal muscle.
1. Incubation of extensor digitorum communis muscles from fed chicks in the presence of plasma concentrations of branched-chain amino acids (BCAA) increased the formation of glutamate, glutamine and alanine. This effect was inhibited by 1.5 mM L-cycloserine. 2. 2-Oxoisocaproate (0.1 and 0.5 mM) increased the formation of leucine but decreased that of glutamate, glutamine and alanine. 3. NH4Cl (0.3 mM) increased the formation of glutamine, and decreased the release and intracellular concentrations of glutamate and alanine. 4. Our results demonstrate that alanine and glutamine are synthesized de novo in chick skeletal muscle and demonstrate the similarity in alanine and glutamine synthesis in skeletal muscle between the domestic fowl and mammals.