Search PubMed⌕ Search

Biomedical subjects

A Shenkin

Publications and source records attributed to A Shenkin.

At least 127 records · Page 7Linked to original sources
PubMed1983

The effect of environmental temperature on protein and energy changes following burn injury in the rat.

The metabolic response to a standard burn injury in rats (25% of body surface area) was investigated at environmental temperature 20 degrees C and 30 degrees C. With an intake of 15 g diet (20% w/w protein) per day, burned rats at 20 degrees C were found to be in negative energy balance mainly due to increased insensible (evaporative) losses, and they lost weight. Fat was the main endogenous source of energy, although protein was also catabolised from both carcass and pelt. At 30 degrees C, insensible losses of burned rats were still high, but they had lower sensible (mainly radiative) losses leading to a positive energy balance and a gain in weight. This consisted mainly of carcass water, fat and protein. Urine catecholamines were higher in burned rats at 20 degrees C than at 30 degrees C and correlated with heat loss, urine nitrogen and urine 3-methylhistidine, supporting the hypothesis that catecholamines play a central role in mediating the protein and energy changes following burn injury. For the first 4-6 days, urine nitrogen and 3-methylhistidine excretion increased in rats at 30 degrees C, suggesting that this early part of the metabolic response is obligatory. These findings support the use of raised environmental temperatures to reduce the metabolic response to burns.

Journal Article↗
PubMed1983

Vitamin and mineral provision during enteral nutrition.

The adequacy of vitamin and mineral provision during enteral nutrition for a period of at least two weeks was studied in 20 patients. Significant increases were observed in plasma levels of vitamins C and E, and in B2, B6 and folate status. No significant changes were observed in vitamins A, B1, B12 or in plasma magnesium, zinc or copper. The requirements for vitamins and minerals during enteral nutrition are discussed.

Journal Article↗
PubMed1983

Assessment of nutritional status and in vivo immune responses in alcoholic liver disease.

Nutritional status and in vivo immune responses were investigated in 30 patients with alcoholic liver disease who were drinking heavily up until emergency hospital admission. Investigations were performed on admission and after 2 wk abstention and adequate hospital diet. No relationship was found between the severity of liver disease revealed histologically and the recent quantity or total duration of alcohol intake, inadequacy of diet, or nutritional status. Skin anergy was more common in those patients with cirrhosis but did not relate to depletion in circulating T lymphocytes, poor nutritional status, or to the direct effect of alcohol toxicity. Acute alcohol toxicity did, however, produce extensive and rapidly reversible metabolic and cellular changes including reduction in serum potassium, magnesium and phosphate and depletion of all circulating lymphocyte subpopulations.

Alcoholic Intoxication↗
PubMed1983

Vitamin A deficiency in Crohn's disease.

Fifty two patients with Crohn's disease (31 outpatients and 21 inpatients) were investigated for evidence of vitamin A deficiency. Eleven (21%) had low plasma retinol concentrations (less than 1.2 mumol/l (34.3 micrograms %)). Five of these were outpatients and plasma retinol was only slightly reduced (greater than 1.0 mumol/l (28.6%)). All outpatients weighed 80% or more of ideal, and were considered at low risk of developing vitamin A deficiency. In contrast, of the six inpatients with low plasma retinol concentration, five had a level of less than 1.0 mumol/l (28.6 micrograms %) and weighed less than 80% ideal. Three of these had impaired dark adaptation and a plasma retinol concentration of less than 0.8 mumol/l (less than 22.9 micrograms %). As a group, the inpatients were more protein depleted than the outpatients, with respect to serum albumin (p less than 0.01), transferrin (p less than 0.001), and prealbumin (p less than 0.001) but retinol binding protein levels were not significantly lower. It is suggested that patients with extensive small bowel Crohn's disease, who weigh less than 80% of ideal weight, merit measurement of plasma retinol concentration. Those with plasma retinol less than 0.8 mumol/l (less than 22.9 micrograms %) run a high risk of night blindness. Vitamin supplements should be given and protein depletion corrected.

Adolescent↗
PubMed1982

Factors affecting excretion of human urinary Tamm-Horsfall glycoprotein.

1. Tamm-Horsfall glycoprotein was determined, by radioimmunoassay, in samples of urine from normal individuals under a variety of physiological conditions. 2. The amount of glycoprotein excreted in 24 h by our population (39 +/- 13 mg, corrected for body surface area) was found not to be influenced by sex, age (19-60 years) or amounts of Ca2+, Mg2+ and Na+ excreted. 3. Urine samples collected at 2 h intervals over 24 h from individuals drinking in response to thirst, contained quantities of the glycoprotein which showed high positive correlations with urine volumes, but not with Ca2+, Mg2+ or Na+ excretion. 4. The amounts of urine and of the glycoprotein were correlated for individuals in antidiuresis, induced by restriction of water intake. Relatively small amounts of glycoprotein were excreted by individuals in states of water-induced diuresis. 5. The amounts of glycoprotein excreted after exercise were positively correlated with the small volumes of urine voided, but they were uninfluenced by the degree of proteinuria or of hyaline cast formation. 6. The half-life for turnover of the glycoprotein in a given individual is highly variable, from a minimum of 3-7 to a maximum of 168 h.

Adult↗
PubMed1982

Clinical experience of zinc supplementation during intravenous nutrition in Crohn's disease: value of serum and urine zinc measurements.

Serum zinc concentrations and urine zinc excretion have been studied in 10 patients with severe Crohn's disease before and during 59 patient-weeks of intravenous nutrition. Before serum zinc concentrations (9.9 +/- 1.0 mumol/l: mean +/- SEM) and urine zinc excretion (3-3 +/- 0.6 mumol/24h) were less than controls (p less than 0.01). No patients had clinical signs of zinc deficiency before intravenous nutrition and none developed signs during it. There was no overall change in serum zinc concentrations, despite improvements in body weight, skinfold thickness, and mid-arm circumference in all patients, and increased serum albumin and serum transferrin concentrations during all but two periods of intravenous nutrition. Nor was there any relationship between serum zinc concentrations and zinc uptake (up to 220 mumol/day), serum zinc concentrations remaining significantly lower than control levels. Urine zinc excretion during the first week of intravenous nutrition showed a 1.2 to 53-fold increase (mean 11-fold) over pre-intravenous nutrition levels, and a positive relationship was demonstrated between zinc intake and urine zinc excretion. It is suggested that zinc supplied by the intravenous route is inefficiently transported to the tissues, and that some is excreted in the form of small molecular weight chelates into urine. Recommendations are made for the supply of intravenous zinc, based on monitoring urine zinc excretion in individual patients.

Adolescent↗
PubMed1982

Emergency biochemistry services--are they abused?

An out-of-hours emergency biochemistry service, which allows access by all medical practitioners of varying experience within a hospital, can lead to overuse or even abuse of limited and costly facilities. When the workload increases, problems of staffing a voluntary (but paid) working rota may emerge. An industrial dispute involving medical laboratory scientific officers (MLSOs) caused the role of the emergency service to be examined and alternative regulating mechanisms to be tested. Experience at Glasgow Royal Infirmary between 1974 and 1981 has been reviewed. From 1977 to 1979, when clinicians (usually junior) arranged analyses directly with the MLSOs, test numbers increased by about 26% per annum. This was not associated with any concomitant increase in the range of analyses offered. During a five-week period in 1980, consultant clinicians had to contact a consultant clinical biochemist to arrange all emergency analyses, and test numbers were reduced to 13% of the previous levels. Subsequently, all requests for emergency analyses were made by clinicians to laboratory medical staff, and test numbers fell to approximately 60% of 1979 levels. This requesting system is now firmly established. Continued vigilance is required to maintain the reduced level of requesting, but too great a limitation on emergency requests may cause less efficient patient management. Senior clinical staff should be encouraged to take greater responsibility for the use of emergency laboratory services.

Chemistry, Clinical↗
PubMed1981

Additives in parenteral nutrition.

Adequate provision of minerals and vitamins is necessary for optimal use of the major nutrients provided in parenteral nutrition. Since the requirements of patients is so variable, it is inevitable that a number of additives will be necessary. Appropriate supplements are now available and these should be added under aseptic conditions by an experienced pharmacist. The accurate prescription of these additives moreover requires close co-operation between clinician, laboratory staff, and the pharmacist.

Humans↗
PubMed1981

Synergism between trimethoprim and sulfonamide in urine: does it exist?

In a randomized, crossover, multiple dose study, ten healthy volunteers received the recommended dosages of cotrimoxazole (80 mg trimethoprim and 400 mg sulfamethoxazole) and co-tri-famole (80 mg trimethoprim and 400 mg sulfamoxole) for five days each. Urinary levels of trimethoprim and each sulfonamide were measured daily for five days. The urinary ratios of trimethoprim and sulfonamide for both formulations were consistently lower than those considered optimal for synergy. Concentration of trimethoprim in the urine from both preparations was found to be greatly in excess of the MIC for trimethoprim-sensitive urinary pathogens (approximately 2 microgram/ml). The sulfonamide levels achieved were not consistently in excess of their MIC (approximately 200 microgram/ml) for either preparation.

Drug Combinations↗
PubMed1980

Biochemical changes associated with severe trauma.

The effects of different intravenous nutritional regimens on a number of biochemical indices of nutritional status were studied during the 8-day period following severe trauma. The inclusion of large amounts of amino acids (high nitrogen (N) was shown to greatly improve N balance over an isocaloric regimen containing no amino acids (O g N). The concentration of serum albumin, transferrin, prealbumin, and retinol-binding protein all fell during the study period in both patient groups, whereas the serum concentrations of acute phase reactants and of ribonuclease increased in the two groups. The sum of plasma levels of branched-chain amino acids and the essential amino acids was increased to a greater extent in the high N group. These amino acid totals and the ratio of glycine/valine showed a significant correlation with N balance in this group. Despite the marked difference in N balance, 3-methylhistidine excretion was increased but equal in the two nutritional groups, suggesting an increased rate of muscle protein breakdown in both groups, which appears not to be influenced by amino acid nutrition. It is concluded that N balance can be significantly improved in the immediate posttrauma period by provision of amino acids together with energy substrates. None of the biochemical variables measured, with the exception of plasma levels of essential amino acids, reflected these marked differences in N balance.

Adult↗
PubMed1980

Home enteral tube feeding with a liquid diet in the long term management of inflammatory bowel disease and intestinal failure.

A 35-year-old man, who had spent 10 1/2 out of 18 months in hospital, has required repeated courses of intravenous nutrition (IVN) because of nutritional failure due to severe inflammatory bowel disease. He has been maintained on a nocturnal pump-fed liquid diet supplementing his day-time oral diet for five months, four of which have been at home. The cost of such therapy is less than with an elemental diet and there are other advantages. This regime has been shown to be nutritionally adequate. The need to assess other cheaper liquid diets in patients with intestinal failure is recognised.

Adult↗