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Biomedical subjects

A Shenkin

Publications and source records attributed to A Shenkin.

At least 109 records · Page 6Linked to original sources
PubMed1987

Sealed versus unsealed knitted Dacron prostheses: a comparison of the acute phase protein response.

Twenty patients were randomized to receive either an untreated Dacron aortic bifurcation graft (n = 10), or a similar graft impregnated with gelatin (n = 10). Venous blood samples were taken preoperatively and at frequent intervals until five weeks after surgery. C-reactive protein (normal range less than 10 mg/l) and alpha l-acid glycoprotein (normal range 0.3-1.0 g/l) were measured. The peak mean value of C-reactive protein for the sealed group was 226.3 +/- 49.2 mg/l and 221.3 +/- 56.4 mg/l for the unsealed group. The corresponding values for alpha 1-acid glycoprotein were 1.49 +/- 0.25 g/l and 1.44 +/- 0.3 g/l. The C-reactive protein response returned more quickly to normal, with only two patients in each group having a slightly elevated response after four weeks, while the value for alpha l-acid glycoprotein remained elevated at five weeks for the same two patients in each group. There was no significant difference between the serum acute phase protein response in either group. This suggests that a knitted Dacron graft sealed with gelatin does not exaggerate the inflammatory response.

Acute-Phase Proteins↗
PubMed1987

Is disordered folate metabolism the basis for the genetic predisposition to neural tube defects?

Vitamin levels were measured in twenty women under 35 years of age with a history of two or more neural tube defect pregnancies. Each index case was compared with a female control matched for age, obstetric history and social class. The mean concentration of red cell folate in the subjects was 178 ng/ml, significantly lower than the mean of 268 ng/ml for the control group (P = 0.005). Red cell folate levels showed a linear relationship with the number of neural tube defect pregnancies, the levels being lowest in women who had had three or four affected offspring. There was no significant difference in serum folate; plasma or white cell vitamin C; plasma vitamin A; thiamine, riboflavine or pyridoxine status; serum vitamin B12; plasma vitamin E; total protein, albumin, transferrin, magnesium, copper or zinc. Diet was assessed by a questionnaire. The dietary intakes of total folate and other vitamins except vitamin A were lower in the subjects than the controls but none of the differences were statistically significant. Regression analysis showed a difference between subjects and controls in the relationship of red cell folate to dietary folate. This study demonstrates an association between susceptibility to offspring with neural tube defects and depressed red cell folate levels which cannot be entirely attributed to a lower dietary intake of folate. It is postulated that one factor predisposing to the occurrence of neural tube defects may be an inherited disorder of folate metabolism.

Adult↗
PubMed1986

Observations on serum iron, zinc, copper and magnesium in intravenously fed patients with chronic sepsis.

In a retrospective study of 176 people who received intravenous nutrition, eight developed a septic episode of at least 12 days duration. We investigated the metabolism of four essential elements (iron, zinc, copper and magnesium) in this group. Plasma concentrations of iron, copper and magnesium followed expected trends; unexpectedly the plasma concentration of zinc was maintained. The implications of these findings in relation to the septic patient are discussed.

Journal Article↗
PubMed1986

Essential trace element provision to patients receiving home intravenous nutrition in the United Kingdom.

The methods of provision of essential trace elements to patients receiving long-term home intravenous nutrition in the U.K. have been reviewed and their trace element status has been assessed. Over a 2 year period, 57 patients based on 15 hospitals throughout the country were studied. Although biochemical abnormalities of trace element status were frequent, related clinical complications were apparently rare. Zinc provision from commercial preparations generally required further supplementation. Copper requirements were variable. Manganese provision from trace element mixtures and chromium provision from contaminants of other parenteral nutrient solutions were excessive in many cases. Aluminium contamination is not significant in the nutrient solutions currently used in the U.K. The most common depletion state is for selenium which should probably be provided on a routine basis. The clinical consequences of long-term under- or over-provision of trace elements by the intravenous route requires further study.

Journal Article↗
PubMed1986

The oxidation of body fuel stores in cancer patients.

In an attempt to define the mechanism of weight loss in cancer patients, fat and carbohydrate oxidation rates were calculated in 93 patients. Seventy patients with colorectal or gastric cancer were compared with a control group of 23 patients with nonmalignant illness. Twenty-seven patients with cancer and 13 control patients had lost more than 10% of their pre-illness body weight. Fat and carbohydrate oxidation rates were derived from measurements of oxygen consumption, carbon dioxide production, and urinary nitrogen excretion. Patients with cancer had significantly higher fat oxidation rates (p less than 0.01) and significantly lower carbohydrate oxidation rates (p less than 0.05) when compared with controls. Weight-losing cancer patients had significantly higher fat oxidation rates when compared with weight-stable cancer patients (p less than 0.02), weight-stable controls (p less than 0.01), and weight-losing controls (p less than 0.02). Cancer patients with liver metastases (N = 14) had significantly higher fat oxidation rates (p less than 0.01) and significantly lower carbohydrate oxidation rates (p less than 0.01) compared with cancer patients who had localized disease. There were no significant differences among the groups with respect to resting energy expenditure when expressed as kilocalorie per kilogram lean body mass per day. The presence of cancer appears to be associated with abnormal fat and carbohydrate metabolism. The increased rate of fat oxidation seen in patients with cancer, especially those with weight loss or liver metastases, may be a significant factor in the development of cancer cachexia.

Aged↗
PubMed1986

Comparison of the nutritional state of new and long-term patients in a psychogeriatric unit.

Nutritional deficiencies have been implicated in the pathophysiology of various mental disorders. Life in institutions has been associated with development of nutritional deficiencies, the elderly being most at risk especially those with senile dementia. In this study nutritional status, particularly vitamin and essential mineral status was assessed in a group of 64 new admissions to a psychogeriatric unit and 49 long-term patients. The results indicated that psychogeriatric patients were at risk of experiencing nutritional deficiencies and those with senile dementia were likely to have more abnormalities than those with functional illnesses. Those patients in long-term care would appear to have a better nutritional state than those on admission.

Aged↗
PubMed1985

Endocrine and protein response to elective surgery: effect of nursing at two different environmental temperatures.

Twenty male patients undergoing elective abdominal surgery were studied on one control day pre-operatively and for the first 4 days postoperatively at an environmental temperature of either 20 degrees C or 28 degrees C. Glucose, insulin, growth hormone and urinary catecholamine levels all rose significantly on the first postoperative day returning to within normal limits by day 4. Urine nitrogen excretion also increased significantly postoperatively in both groups. Environmental temperature did not influence these responses. Concentrations of C-reactive protein and a1-antichymotrypsin increased significantly on the first postoperative day and were returning to normal by day 4 while concentrations of haptoglobin, a1-antitrypsin and a1-acid glycoprotein, which also showed a significant increase, remained elevated at the end of the study. Concentrations of albumin, transferrin, a2-macroglobulin, prealbumin and retinol binding protein all decreased significantly following operation. Elevated environmental temperature did not affect the protein response to surgery. Urine cortisol and 17-hydroxycorticosteroid excretion rose significantly postoperatively and remained elevated throughout the study. Patients nursed at 28 degrees C showed significantly lower postoperative excretion of both hormones than patients nursed at 20 degrees C.

Journal Article↗
PubMed1985

Effect of sulphonylurea administration on insulin secretion and amino acid metabolism in non-insulin-dependent diabetic patients.

Sulphonylureas lower blood glucose but other metabolic effects have been little studied. In an assessment of carbohydrate and amino acid metabolism in 9 patients with non-insulin-dependent diabetes mellitus (NIDDM) before and after 3 months' therapy with gliclazide, glycaemic control was improved (mean +/- S.D. glycosylated haemoglobin 13.8 +/- 1.9% before therapy, 10.2 +/- 2.1% after therapy (p less than 0.01], but fasting amino acid levels were not altered. In contrast, postprandial levels of branched chain amino acids (BCAA) were significantly reduced: total BCAA (valine, leucine, and isoleucine) 120 mins following a standard test meal fell from 717 +/- 71 mumol/l before therapy to 600 +/- 90 mumol/l after 3 months' therapy (p less than 0.01). This finding implies an increased action of endogenous insulin on skeletal muscle to promote uptake of BCAA postprandially and, in accord with this, peripheral insulin levels were significantly increased following drug treatment (peak insulin level 55.6 +/- 20.2 mU/l before therapy, 91.3 +/- 17.9 mU/l after therapy (p less than 0.01]. Sulphonylurea drugs therefore do not simply have a hypoglycaemic action but also affect amino acid metabolism in NIDDM patients.

Adult↗
PubMed1984

Modification of postoperative nitrogen balance with preoperative anabolic steroid.

Thirty six patients undergoing abdominal operations were randomly allocated to receive an anabolic steroid, stanozolol (50 mg) or placebo 24 h before surgery. Patients were fasted during the first four postoperative days. During this period the mean daily nitrogen balance was significantly less negative in the stanozolol group (-8.0+/-3.0 gN/day) than in the control group (-10.9+/-4.1 gN/day), although improvement in nitrogen balance was greater in male than in female patients. Muscle catabolism as measured by 3-methylhistidine excretion was similar in both treatment groups. Significant fluid retention occurred in the stanozolol treated group and was more marked in female patients. Improved nitrogen balance in the absence of a measurable change in muscle catabolism suggests that this anabolic steroid acts by improving protein synthesis in the early period after surgery.

Journal Article↗
PubMed1984

Transient hypercalciuria after commencing total intravenous nutrition.

A study of 28 patients receiving a standard regimen of total intravenous nutrition (I.V.N.) for periods of > 14 days has shown the transient development of hypercalciuria in 14 patients (50%). The peak incidence of hypercalciuria occurred in 11 patients (39%) after 1 week of I.V.N. and hypercalciuria persisted for 1-4 weeks. In only one patient was hypercalciuria present at the end of the treatment period. Urine calcium (Ca) and nitrogen (N) excretion rates correlated significantly (r = 0.48 p < 0.001) and urine N excretion varied from week to week in parallel with urine Ca excretion in the hypercalciuric group of patients. There was no significant difference in urine Ca excretion between 12 patients who received 3.75 mmol Ca/day and 16 patients who received 8.75 mmol Ca/day. It is concluded that transient hypercalciuria may be related to increased protein catabolism and N excretion and that it probably does not indicate a major problem in mineral metabolism.

Journal Article↗
PubMed1984

BM strips: how accurate are they in general wards?

In order to test the accuracy of BM Test Glycemie 20-800 strips when used in general wards, simultaneous BM strip results were obtained for 183 emergency out-of-hours plasma glucose requests. The results were considered accurate if the value obtained by the Emergency Biochemistry Laboratory (using a Beckman II glucose analyser) was within one strip-range on either side of the stated BM strip value. Fifty-nine (32.2%) of the BM strip results were considered inaccurate by this definition, and in 22 of these inaccurate results the differences were large enough to have led to inappropriate management if this was based on the BM strip result alone. The reasons for these inaccuracies are not clear, but it is suggested that improved training of ward staff and formal quality control schemes may help to improve results.

Blood Glucose↗
PubMed1983

The effect of isotonic amino acid infusions on serum proteins and muscle breakdown following surgery.

Twenty patients undergoing major surgical procedures received constant infusion (21/day) of either 3.5 per cent amino acid (AA) or 5 per cent dextrose (D5W) solutions in addition to other fluid requirements for 4 postoperative days. Ketosis was evident in AA patients as a mean daily beta-hydroxy butyrate excretion of 2.16 +/- 1.39 mmol and respiratory quotient of 0.708 +/- 0.013 compared with 0.28 +/- 0.45 mmol/day and 0.754 +/- 0.015 respectively in the D5W group. The serum total protein and albumin concentrations (but not those of transferrin and prealbumin) were significantly higher in the AA than the D5W group on day 4. However, the mean fluid balance for days 3 and 4 was significantly less positive in AA patients. The mean daily nitrogen balance of -6.6 +/- 7.7 gN/day in AA patients and -9.5 +/- 5.8 gN/day in D5W patients was not significantly different. Mean daily 3-methyl histidine excretion (38.2 +/- 12.3 mumol/mmol creatinine) in AA patients was significantly higher than in D5W patients (31.2 +/- 10.8 mumol/mmol creatinine). With no improvement in nitrogen balance, an increase in muscle protein breakdown and the possibility that decreased fluid retention explains the higher serum total protein and albumin levels, this study fails to demonstrate improved protein sparing by isotonic amino acid infusions following surgery.

Adult↗
PubMed1983

The relationship between delayed hypersensitivity response, nutritional status and clinical outcome in surgical patients referred for nutritional support.

Delayed hypersensitivity responses to recall antigens were measured in 125 surgical patients referred for nutritional assessment and support. On initial testing 57 patients were skin test positive and 68 were anergic each of these patient groups being closely matched in terms of surgical conditions. There was a mortality of 4 in the skin test positive group and 26 in the anergic group. The anergic patients were significantly older and in biochemical and anthropometric terms were in poorer nutritional status than the skin test positive group. Of 33 anergic patients who were repeat tested, 15 remained anergic and 18 converted to a positive response. Conversion from anergy to a positive response was not associated with changes in the measured indices of nutritional status and did not improve clinical outcome. The value of repeat skin testing is therefore in doubt.

Journal Article↗