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Biomedical subjects

D B Silk

Publications and source records attributed to D B Silk.

At least 91 records · Page 5Linked to original sources
PubMed1986

Improved design of nasogastric feeding tubes.

Disappointed with the overall performance of weighted and unweighted nasogastric feeding tubes, a design programme was initiated which resulted in the development of two new nasogastric tubes, one weighted and one unweighted. The tubes were manufactured with polyurethane rather than polyvinylchloride (PVC) which permitted an increase in diameter of the internal lumen which in turn was coated with water activated lubricant to ease removal of the introducer wire. A specially modelled outflow port was incorporated into the tips of both tubes. The performance of the two new polyurethane nasogastric feeding tubes was assessed under controlled trial condition using as a reference a widely used PVC unweighted open ended tube. While intubation times were similar in patients without concurrent endotracheal intubation, it took a significantly shorter time to intubate patients with concurrent endotracheal intubation with the new weighted tube. Following tube intubation, it was possible to aspirate gastric contents significantly more often through the new polyurethane tubes (p < 0.001) than through the PVC tube, and the unweighted polyurethane tube stayed in situ longer (p < 0.05) than the PVC tube. The newly designed polyurethane nasogastric feeding tubes are the first tubes that have been shown to have advantages over the simpler type of open ended, unweighted PVC nasogastric feeding tubes.

Journal Article↗
PubMed1986

Effect of peptide chain length on amino acid and nitrogen absorption from two lactalbumin hydrolysates in the normal human jejunum.

A double lumen jejunal perfusion technique has been used in man to study the effect of peptide chain length on absorption of amino acid nitrogen from two partial enzymic hydrolysates of lactalbumin. Copper-chelation chromatography showed that one lactalbumin hydrolysate (LH2) contained 98% peptides with a chain length greater than 4, whilst the other (LH1) contained a more even spread of chain lengths with 55% less than 4. Absorption of total nitrogen and of 14 amino acid residues occurred to a significantly greater extent from the low molecular weight LH1 than from the higher molecular weight LH2. The results suggest that the pattern of nitrogen and amino acid absorption from partial enzymic hydrolysates of whole protein is markedly influenced by peptide chain length and that brush border peptide hydrolysis has an important rate limiting effect on absorption rates.

Absorption↗
PubMed1986

Future of enteral nutrition.

Although there has been agreement that enteral nutrition remains an excellent means of providing nutritional support to malnourished patients with normal or near normal gastrointestinal function, it is clear that areas of controversy do exist, and attention needs to be directed towards these in the future.

Enteral Nutrition↗
PubMed1985

Do fibre containing enteral diets have advantages over existing low residue diets?

This study investigated the influence of fibre on the pattern of absorption of protein and carbohydrate following administration of polymeric enteral diet and also the effect of added fibre on frequency of bowel action, stool weight and gastrointestinal side effects during enteral nutrition. No difference was seen in frequency of bowel action, stool weight or gastrointestinal side effects in five patients fed with either a fibre free polymeric diet or with the same diet augmented with 24 g fibre/24 h. Addition of fibre did not significantly alter breath hydrogen excretion. In an oral tolerance test on six normal subjects, the post prandial rises in blood glucose and levels of 17 amino acids were similar on ingestion of a fibre containing or fibre free test meal.

Journal Article↗
PubMed1985

Abdominal tuberculosis in urban Britain--a common disease.

Between 1973 and 1983 abdominal tuberculosis was responsible for the admission of 90 patients to a west London district general hospital. Over the same period Crohn's disease was newly diagnosed in 102 hospitalised patients. In contrast with Crohn's disease, the majority (75) of tuberculous patients were Asian immigrants. Mean duration of residence in the United Kingdom was 4 +/- 0.9 (SD) years, and mean age at presentation was 34.9 +/- 1.1 years. Forty per cent of tuberculosis patients presented as an acute emergency to physicians, surgeons, or gynaecologists while the remainder presented a more insidious, chronic picture. Five groups of tuberculous patients were recognised. Forty two subjects had intestinal tuberculosis characterised by pain (100%), abdominal mass (43%) and abnormal contrast radiology (100%). Ten of these underwent emergency laparotomy for intestinal obstruction or perforation. Twenty seven patients had tuberculous peritonitis although only 16 had ascites. Eight patients presented with pyrexia and granulomatous hepatitis. Five had pulmonary and abdominal tuberculosis. The remaining eight patients represented a miscellaneous group. The diagnosis of abdominal tuberculosis was established histologically (60 cases), bacteriologically (six cases) or radiologically (24 cases). Chest radiograph, tuberculin skin testing and paracentesis were usually unhelpful. Five severely ill patients died. The remainder recovered completely after specific triple chemotherapy and response to treatment was usually evident within 14 days. In urban Britain tuberculosis is an important cause of abdominal disease. Prognosis is excellent following specific therapy.

Abdomen↗
PubMed1985

Influence of protein composition and hydrolysis method on intestinal absorption of protein in man.

An intestinal perfusion technique has been used in normal human subjects to investigate the influence that starter protein composition and hydrolysis procedure have on absorption of amino acid residues from partial enzymic hydrolysates of whole protein. Five starter proteins were studied. Three (egg albumin, casein/soy/lactalbumin, and lactalbumin) were hydrolysed by papain, a second lactalbumin starter protein, and a meat/soy/lactalbumin blend were hydrolysed by a porcine pancreatic enzyme system. Irrespective of starter protein composition or hydrolysis method used, four amino acid residues (threonine, glutamic acid, phenylalanine, and histidine) were absorbed significantly faster from all hydrolysates compared with absorption from their equivalent free amino acid mixtures. In contrast, both starter protein composition and hydrolysis method influenced absorption characteristics of up to nine other amino acid residues.

Adult↗
PubMed1985

Ergotamine abuse and extra-hepatic portal hypertension.

Arterial complications following ergotamine therapy have been well recognized since the beginning of this century. Venous complications, however, have only rarely been reported. A 48 year old Nigerian woman developed extra-hepatic portal hypertension coincident with a chronic overdosage of ergotamine. The literature elucidating the possible mechanisms involved is reviewed.

Ergotamine↗
PubMed1984

Relation between osmolality of diet and gastrointestinal side effects in enteral nutrition.

One hundred and eighteen patients with normal gastrointestinal function were randomly allocated to one of three feeding regimens in a double blind study to determine the relation between the tonicity of the diet and gastrointestinal side effects related to the diet and to evaluate the efficacy of "starter" regimens in reducing gastrointestinal side effects during enteral nutrition. Patients received a hypertonic diet with an osmolality of 430 mmol (mosmol)/kg (group 1), the same diet but with the osmolality increasing from 145 to 430 mmol/kg over the first four days (group 2), or an isotonic diet (300 mmol/kg) (group 3). All diets were prepared aseptically and administered by 24 hour nasogastric infusion. The mean daily nitrogen intake in group 1 was significantly greater (p less than 0.05) than that in both groups 2 and 3, and the mean overall daily nitrogen balance was significantly better (p less than 0.05) in group 1 than groups 2 and 3. The incidence of side effects related to the diet was similar in all three groups, but diarrhoea was significantly (p less than 0.001) associated with concurrent treatment with antibiotics. These findings show that undiluted hypertonic diet results in significantly better nitrogen intake and balance, that starter regimens reduce nutrient intake but not symptoms, and that diarrhoea is significantly related to treatment with antibiotics and not to administration of an undiluted hypertonic polymeric diet.

Clinical Trials as Topic↗
PubMed1984

Inhibition of jejunal water and electrolyte absorption by therapeutic doses of clindamycin in man.

A steady-state perfusion technique has been used in vivo in normal subjects to show that at concentrations occurring during therapeutic use (500 mg/1, 1.1 mmol/l) the antibiotic clindamycin reversibly inhibits bicarbonate-stimulated water and electrolyte absorption from the human jejunum. Lactose-stimulated water and electrolyte absorption was not affected by the addition of clindamycin at the same concentration. Clindamycin-induced malabsorption of water and electrolytes may contribute significantly to the diarrhoea that occurs during clindamycin therapy in the absence of pseudomembranous colitis.

Adolescent↗
PubMed1984

The ileal brake--inhibition of jejunal motility after ileal fat perfusion in man.

The possibility that malabsorbed fat passing through the human ileum exerts an inhibitory feedback control on jejunal motility has been investigated in 24 normal subjects by perfusing the ileum with a fat containing solution designed to produce ileal luminal fat concentrations similar to those in steatorrhoea (30-40 mg/ml). Mean transit times through a 30 cm saline perfused jejunal segment were measured by a dye dilution technique. Thirty minutes after ileal fat perfusion, mean transit times rose markedly to 18.9 +/- 2.5 minutes from a control value of 7.5 +/- 0.9 minutes (n = 5; p less than 0.05). This was associated with an increase in volume of the perfused segment which rose to 175.1 +/- 22.9 ml (control 97.6 +/- 10.3 ml, n = 5; p less than 0.05). Transit times and segmental volumes had returned towards basal values 90 minutes after completing the fat perfusion. Further studies showed that ileal fat perfusion produced a pronounced inhibition of jejunal pressure wave activity, percentage duration of activity falling from a control level of 40.3 +/- 5.0% to 14.9 +/- 2.8% in the hour after ileal perfusion (p less than 0.01). Ileal fat perfusion was associated with marked rises in plasma enteroglucagon and neurotensin, the peak values (218 +/- 37 and 68 +/- 13.1 pmol/l) being comparable with those observed postprandially in coeliac disease. These observations show the existence in man of an inhibitory intestinal control mechanism, whereby ileal fat perfusion inhibits jejunal motility and delays caudal transit of jejunal contents.

Adult↗