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Biomedical subjects

D M Russell

Publications and source records attributed to D M Russell.

At least 37 records · Page 2Linked to original sources
PubMed1986

Effects of peritoneovenous shunting on body composition.

The effect of peritoneovenous shunting on body composition has been studied in 7 cirrhotic patients undergoing a successful shunt and 3 patients in whom the shunt was unsuccessful. In the 7 patients with functioning shunts, their weight had decreased by a mean of 9 kg (p less than 0.001) by 6 wk after initial diuresis, natriuresis, and kaliuresis, and was associated with a decrease in total body potassium (TBK) but not total body nitrogen (TBN). This resulted in a significant decrease in the TBK/TBN ratio from 2.12 +/- 0.74 to 1.66 +/- 0.20 (p less than 0.01). By a mean of 14 mo, in these 7 patients there was a significant increase in mean TBN (from 1.54 +/- 0.10 to 1.84 +/- 0.10, p less than 0.005) associated with an improvement in the mean nitrogen index (from 0.74 +/- 0.04 to 0.88 +/- 0.04, p less than 0.005). These changes were associated with a significant increase in nonalcoholic calories, a nonsignificant increase in protein consumption, and a positive nitrogen balance. After the initial kaliuresis, mean potassium balance remained constantly positive (+22.7 +/- 3.4 mmol/day), serum aldosterone levels normalized, and TBK increased. In contrast, 3 patients with failed peritoneovenous shunting continued to lose weight significantly despite the presence of ascites; TBN and nitrogen index also decreased. In conclusion, body composition studies appear to have confirmed the clinical observation that cirrhotic patients with massive ascites have depleted body protein which is gradually repleted only after successful shunting. In this situation TBK, long used as a measure of lean body mass, is less satisfactory than TBN and nitrogen index. This improvement in body protein appears to be explained by an increased dietary intake associated with improved nitrogen balance, but these changes are not found in patients in whom the shunt failed.

Adult↗
PubMed1985

A survey to evaluate the management of orthodontic patients with a history of rheumatic fever or congenital heart disease.

A survey concerning the orthodontic management of patients with a history of rheumatic fever or congenital heart disease was mailed to a random sample of 500 orthodontists throughout the United States. Two hundred thirty-two surveys were completed and returned. Analysis revealed that 88% of the respondents were aware that they should screen for patients with a history of rheumatic fever or congenital heart disease, only 11% used the antibiotic regimen recommended in 1977 by the American Heart Association (see Fig. 2), one half of the respondents thought it was necessary to provide antibiotic coverage during banding, and 38% deemed it necessary for debanding procedures which were likely to cause some degree of bleeding from the gingival sulcus. Only one half of the respondents would discontinue treatment if a condition of gingivitis developed which did not show signs of improvement, and only 70% provided medication for orthodontic procedures that could result in bacteremia. Furthermore, the results of this survey indicated that there was a great variation in the antibiotic regimen of orthodontic treatment for patients at risk of developing endocarditis and that there was a need to make the orthodontist more aware of the 1977 recommendations of the American Heart Association. Finally, a comparison between the year of graduation from an orthodontic program and the number of respondents who did not screen for or did not premedicate at-risk patients revealed a direct relationship. The earlier the education, the smaller the number of respondents who screened or premedicated.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗
PubMed1984

The effect of fasting and hypocaloric diets on the functional and metabolic characteristics of rat gastrocnemius muscle.

Previous observations have shown that in human subjects with malnutrition and after prolonged fasting, there are characteristic changes in the force-frequency response, relaxation rate and power of muscle during a 30 s stimulus (fatigue). In order to characterize these findings under carefully controlled conditions, in different types of muscle and to correlate them with changes in muscle structure, composition and biochemical status, we developed an animal model in rats. In this model, nutrient restriction, both after an acute fast and after chronic hypocaloric feeding, resulted in: (a) loss of force during high frequency stimulation but preservation of contraction-relaxation characteristics during low frequency stimulation; (b) slower muscle relaxation rate at high frequency stimulation; (c) increased muscle fatiguability at high frequency stimulation. Measurements of muscle enzymes showed that acute fasting resulted in a reduced content of glycolytic enzymes, but preservation of oxidative enzymes, while chronic hypocaloric dieting resulted in a reduction in both classes of enzyme. There was no significant change in ATP, AMP or energy charge, or in intracellular sodium, potassium and magnesium levels. Creatine phosphate was normal in acutely fasted animals but low in those fed hypocalorically. By contrast, increased intracellular calcium and ADP levels were seen in both fasted and hypocalorically fed animals. These findings suggest that subtle disturbances of intracellular energy states with altered calcium flux may be of importance in the genesis of muscle dysfunction caused by malnutrition.

Animals↗
PubMed1984

Metabolic and structural changes in skeletal muscle during hypocaloric dieting.

Hypocaloric dieting and fasting alter the contraction-relaxation characteristics of skeletal muscle and result in low frequency fatigue. We report the metabolic and structural changes in skeletal muscle in five morbidly obese female subjects who had biopsies of the gastrocnemius muscle on a base-line diet (2500 kcal/day) followed by a repeat biopsy after 2 wk of a 400-kcal/day carbohydrate diet. Hypocaloric dieting resulted in a significant increase in the intracellular muscle calcium content (p less than 0.05), which may account for the observed changes in muscle function. There were no significant changes in muscle glycogen, lactate, pyruvate, or free energy stores. There was a significant decrease in muscle enzymes [phosphofructokinase (p less than 0.05), succinate dehydrogenase (p less than 0.02)] and some muscle amino acid levels [glutamine (p less than 0.025), glycine (p less than 0.01), and alanine (p less than 0.02)], while muscle histochemistry showed type II fiber atrophy (p less than 0.025). However, these changes reflect a generalized response to hypocaloric dieting and probably do not explain the specific functional changes. Change in the muscle calcium content is probably an important mediator of the adverse functional effects of malnutrition.

Adolescent↗
PubMed1984

Effects of total parenteral nutrition and chemotherapy on the metabolic derangements in small cell lung cancer.

Changes in energy metabolism, substrate use, and hormone profiles were prospectively studied in 31 patients with small cell lung cancer receiving chemotherapy. Patients were randomized to receive either 4 weeks of total parenteral nutrition (n = 15) or to continue self-regulated p.o. diet (control group; n = 16). The initial actual resting energy expenditure measured by indirect calorimetry was 31% higher than the predicted resting energy expenditure determined by the Harris-Benedict formula. The p.o. calorie intake was inappropriately low for these hypermetabolic patients. Total parenteral nutrition resulted in a significant positive net energy balance, but in follow-up was associated with prolonged anorexia and a negative energy balance. Complete response to therapy reduced resting energy expenditure and increased calorie intake, whereas the contrary was true in nonresponders. Elevated plasma-free fatty acids (800 +/- 62 microM; S.E.) and a low respiratory quotient (0.74 +/- 0.02) indicate that the dominant energy source in patients with small cell lung cancer is fat, and that increased fat oxidation continues despite tumor response. Elevated fasting plasma catecholamines and insulin resistance may contribute to continued fat mobilization. Initially, there was a significant increase in blood lactate (1118 +/- 95 microM) suggesting either increased tumor or tumor-mediated glycolytic activity. Response to therapy was associated with a fall in blood lactate levels. The most effective way of improving the metabolic derangements in patients with small cell lung cancer was to achieve tumor response to therapy.

Adult↗
PubMed1983

Skeletal muscle function during hypocaloric diets and fasting: a comparison with standard nutritional assessment parameters.

Skeletal muscle function and standard nutritional assessment parameters were measured in six obese patients. Base-line measurements were made on a weight-maintaining diet, and further measurements after 2 wk of a 400-cal diet, followed by 2 wk of fasting and then after 2 wk of refeeding. The function of the adductor pollicis muscle was assessed by electrical stimulation of the ulnar nerve. The objective parameters of muscle function measured were: 1) force of contraction expressed as a percentage of the maximal force obtained with electrical stimulation at 10, 20, 30, 50, and 100 Hz. 2) Maximal relaxation rate expressed as percentage force loss/10 ms. 3) Endurance expressed as percentage force loss/30 s. Standard nutritional assessment parameters (serum albumin and transferrin, creatinine height index, anthropometry and total body nitrogen and potassium) were also measured. There was a significant increase in the force of contraction at 10 Hz from a base-line of 29.6 +/- 1.0% to 49.0 +/- 2.8% (mean +/- SEM) after 2 wk of a 400-cal diet (p less than 0.01). These was a significant slowing of the maximal relaxation rate from a base-line of 9.8 +/- 0.03% force loss/10 ms to 8.2 +/0 0.3% force loss/10 ms (mean +/- SEM) (p less than 0.01) after 2 wk of a 400-cal diet. After a further 2 wk of fasting these abnormalities in muscle function persisted. There was a significant increase in muscle force loss from a base-line of 3.9 +/- 0.8% force loss/30 s to 13.7 +/- 3.4% force loss/30 s (mean +/- SEM) after fasting (P less than 0.01). After 2 wk of refeeding all aspects of muscle function measured were normal. During the study the standard nutritional assessment parameters did not change significantly.

Adult↗
PubMed1983

A comparison between muscle function and body composition in anorexia nervosa: the effect of refeeding.

Skeletal muscle function, body composition (total body nitrogen and total body potassium) and standard parameters of nutritional assessment were measured in six severely depleted patients with primary anorexia nervosa, both on admission and during oral refeeding. The function of the adductor pollicis muscle was assessed by electrical stimulation of the ulnar nerve. On admission muscle function was markedly abnormal in the patients with anorexia nervosa (n = 6) compared with normal subjects (n = 22), with a significant increase in the force of contraction at 10 Hz, with a mean +/- SEM of 48.0 +/- 3.7% and 28.8 +/- 1.2%, respectively (p less than 0.001). There was slowing of the maximal relaxation rate, 6.6 +/- 0.6% and 9.6 +/- 0.2%, respectively (p less than 0.001) and increased muscle fatigue 18.6 +/- 5.9% and 3.5 +/- 0.8%, respectively (p less than 0.01). Initially, the mean serum albumin was normal (4.0 +/- 0.1 g/dl), although there was evidence of severe depletion of somatic protein stores, with a low total body nitrogen and creatinine-height index. Within 4 wk of oral refeeding, maximal relaxation rate and muscle fatigability were restored to normal, and within 8 wk all parameters of muscle function were normal. During the study total body nitrogen increased by only 13% and was still 19.4% below the predicted normal total body nitrogen, whereas total body potassium increased by 32% and body fat by 46%. Normalization of muscle function may be related to restoration of muscle electrolytes rather than repletion of body nitrogen.

Adult↗
PubMed1983

Complete remission in Cronkhite-Canada syndrome.

A case of Cronkhite-Canada syndrome, where there was complete remission confirmed by radiology, endoscopy, and histology, is reported. On presentation, there was generalized gastrointestinal polyposis, hypoalbuminemia, skin pigmentation, onycho-dystrophy, and alopecia. Enteral nutrition alone was administered for 10 wk, with resolution of the ectodermal features and disappearance of the polyps within 4 mo of commencement of the treatment. This report of complete remission supports the generally accepted nonneoplastic and essentially inflammatory nature of the polyps in Cronkhite-Canada syndrome. Consideration needs to be given to nutritional deficiency as a cause of the syndrome.

Aged↗
PubMed1982

Skeletal muscle function in malnutrition.

Skeletal muscle function was studied in 10 malnourished patients with various gastrointestinal disorders and in 22 normal subjects. The function of the adductor pollicis muscle was assessed by electrical stimulation of the ulnar nerve. The objective parameters of muscle function measured were: 1) Force of contraction expressed as a percentage of the maximal force obtained with electrical stimulation at 10, 20, 30, 50 and 100 Hz. 2) Maximal relaxation rate expressed as percentage force loss/!10 ms. 3) Endurance expressed as percentage force loss/30 s. The force of contraction at 10 Hz was higher in malnourished patients compared with normal subjects, with a mean +/- SEM (n) of 43.0 +/- 4.2% (n = 10) and 28.8 +/- 1.2% (n = 22), respectively, (p less than 0.001). The maximal relaxation rate was slower in patients compared with normals with a mean +/- SEM (n) of 7.2 +/- 0.4% (n = 9) ad 9.6 +/- 0.2% (n = 22), respectively, (p less than 0.001). Muscle endurance testing showed an increased force loss with prolonged tetanic stimulation in patients compared with normals, with a mean +/- SEM (n) of 29.1 +/- 4.0% (n = 7) and 3.5 +/- 0.8% (n = 22), respectively, (p less than 0.001). Four patients were restudied after a 4-wk period of total parenteral nutrition, with a significant improvement in muscle function parameters. Malnutrition results in both increased muscle fatiguability and an altered pattern of muscle contraction and relaxation which are reversible by nutritional supplementation. This technique promises to be valuable in assessing the functional effects of malnutrition and the response to nutritional support.

Adolescent↗
PubMed1982

Carcinoma of the papilla of Vater.

Carcinoma of the papilla of Vater was diagnosed in 18 patients during the period 1970 to 1980. In ten patients, surgical treatment was facilitated by a preoperative diagnosis based on duodenal endoscopy, biopsy, cytology and retrograde cholangiopancreatography. Of 16 patients with apparently localised disease at laparotomy, nine had pancreatoduodenectomy (Whipple's operation), three had local resection and four had biliary bypass. Six of nine patients treated by pancreatoduodenectomy are surviving for periods ranging from one to ten years, mean four years, whereas the four patients treated by biliary bypass survived for 0 to 18 months. Tumour recurred in the region of the papilla in two of three patients treated by local resection. Carcinoma of the papilla of Vater is usually localised at the time of diagnosis and prolonged survival can be achieved by pancreatoduodenectomy.

Adenocarcinoma↗