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Biomedical subjects

B Beck

Publications and source records attributed to B Beck.

At least 127 records · Page 7Linked to original sources
PubMed1988

Effect of the duration of malnutrition and of nutritional rehabilitation on blood glucose homeostasis and pancreatic hormones in rats.

1. To study the efficiency of rehabilitation after different periods of protein-energy malnutrition, we used as a model preweaning malnourished rats. After weaning, male Wistar rats were fed on a protein-deficient diet (50 g casein/kg) ad lib. for the whole study (DR group) or rehabilitated with normal diet (180 g casein/kg; RR group) from weaning, week 0, or weeks 1, 3, 5, 8 and 16 thereafter. 2. Twelve animals from the DR group were killed at the beginning of each rehabilitation period. The twelve rehabilitated rats were killed after 2 weeks. Body-weight and epididymal adipose tissue weight, blood glucose, plasma immunoreactive insulin (IRI) and immunoreactive glucagon (IRG), and pancreatic contents of IRI and IRG were determined. 3. Food intake of RR rats rose significantly except during the last period where body-weight increased less than that during the previous period. Fat-pad weights increased in the same manner in DR and RR groups. 4. Blood glucose fell and plasma IRG rose significantly without any change in plasma IRI after each rehabilitation period, except during the last period where blood glucose concentrations became stable. Pancreatic IRG and IRI showed the same type of response to those of the plasma. 5. All short-term rehabilitation periods were similarly efficient at producing catch-up growth. High insulin sensitivity of target cells was responsible for good recovery except after long-term malnutrition.

Animals↗
PubMed1988

Self-assessment of selected interpersonal abilities in hard of hearing and deaf adolescents.

An understanding of the ability of persons with hearing impairments to interact socially needs to consider the impact of their disabilities on communication with non-disabled persons. This study examined the responses of 197 hard of hearing and deaf adolescents and a control group of 53 non-disabled young people between 14 and 18 years of age to statements in a questionnaire designed to elecit how they might behave in different contexts, with additional, independent assessment of the subjects by teachers and other educational staff. Results suggest that biological differences alone do not account for differences in self-conception found between those with hearing disabilities and those without, nor between different subgroups of those with hearing disabilities. Other cognitive, emotional, motivational and social factors also play a part. This opens up the possibility of developing new rehabilitation and training programmes to help young people with hearing disabilities acquire more positive self-assessments.

Adolescent↗
PubMed1988

New catheter technique for recording left free-wall accessory atrioventricular pathway activation. Identification of pathway fiber orientation.

The ability to record accessory atrioventricular (AV) pathway activation consistently may be uniquely beneficial in improving pathway localization, identifying anatomic relations, and providing insight into unusual conduction properties. For the purpose of recording left AV accessory pathway activation, an electrode catheter was specially designed for use in the coronary sinus. The orthogonal catheter has three sets of four electrodes spaced evenly around the circumference. Electrograms were recorded at low gain (less than 1 cm/mV) between adjacent electrodes on the same set (interelectrode distance, 1.5 mm, center to center). This provides a recording dipole perpendicular to the atrioventricular groove to enhance recording of accessory pathway activation while minimizing overlapping atrial or ventricular potentials. The orthogonal electrode catheter was used in the electrophysiological study of 48 consecutive patients with 59 left AV accessory pathways. The catheter could be advanced along the coronary sinus beyond the site of earliest retrograde atrial activation in 49 of the 59 accessory pathways. Activation potentials were recorded from 45 of the 49 (92%) accessory pathways accessible to the catheter (5 of 5 anterior, 8 of 8 anterolateral, 15 of 16 lateral, 5 of 5 posterolateral, 5 of 5 posterior, and 7 of 10 posteroseptal). Accessory pathway potentials were validated by dissociating them from both atrial and ventricular activation by programmed-stimulation techniques. During surgery, accessory pathway potentials were identified from orthogonal catheter electrodes in the coronary sinus in 14 of 16 accessory pathways (12 patients). Epicardial mapping confirmed the location of the accessory pathway, and direct pressure over the orthogonal catheter electrode that recorded the accessory pathway potential resulted in transient conduction block in nine of the 14 accessory pathways. Orthogonal electrode maps of the coronary sinus identified an oblique course in 39 of 45 recorded accessory pathways. Thirty-two of 38 left free-wall accessory pathways were oriented with atrial insertion 4-30 mm (median, 14 mm) proximal (posterior) to the ventricular insertion. In the remaining six free-wall accessory pathways, the lateral excursion could not be determined because either only the atrial end of the accessory pathway was recorded or activation of multiple pathway fibers prevented tracking of individual strands. The seven recorded posteroseptal pathways exhibited accessory pathway potentials throughout an 8-18-mm (median, 10 mm) length of the proximal coronary sinus, but fiber orientation was difficult to determine.(ABSTRACT TRUNCATED AT 400 WORDS)

Atrioventricular Node↗
PubMed1988

Effects of somatostatin on the insulin- and gastric inhibitory polypeptide-stimulated fatty acid esterification in rat adipose tissue.

Relations exist between insulin, somatostatin (S) and gastric inhibitory polypeptide (GIP) for the reciprocal control of their secretion but also for their role in lipid metabolism. In the present experiment, we studied the effects of somatostatin on fatty acid incorporation into epididymal adipose tissue (FIAT) of Wistar rats when it was stimulated by insulin and GIP. Cyclic somatostatin-14 was used at physiological (S1 : 50 pg/ml, S2 : 200 pg/ml) and supraphysiological (S3 : 666 pg/ml) concentrations whereas insulin and GIP were used at postprandial levels (100 microU/ml and 2 ng/ml respectively). Results were expressed as percent of basal incorporation (without any hormones). Somatostatin inhibited basal FIAT at all concentrations and totally abolished the insulin-stimulated FIAT (from 106.4 +/- 2.3 per cent with insulin alone to 92.6 +/- 2.5 per cent with S3, P less than 0.001). GIP enhanced the insulin-stimulated FIAT from 106.4 +/- 2.3 per cent to 113 +/- 3.0 per cent (P less than 0.01). On the contrary, when somatostatin was added with GIP and insulin, FIAT decreased to 102.3 +/- 2.5 per cent for S1 (P less than 0.01) and to 98.2 +/- 2.6 per cent for S3 (P less than 0.001). These results indicate that somatostatin totally inhibits the fatty acid esterification induced by insulin and in the same proportions that induced by insulin associated with GIP. Somatostatin is not only an inhibitor of the secretion of these hormones but also a regulator of their biological action in adipose tissue.

Adipose Tissue↗
PubMed1987

A transformer-coupled double-resonant probe for NMR imaging and spectroscopy.

A new type of double-resonant coil which takes advantage of the properties of a radio-frequency transformer is described. Two concentric loops are wound in close proximity to yield a high mutual inductance. The primary side is tuned to 34 MHz for 31P and the secondary side is tuned to 85 MHz for protons. A single lead allows program control over frequency without the need to rearrange cabling. Proton and phosphorus spectroscopy are made possible over essentially the same volume of interest without the need for repositioning the sample.

Equipment Design↗
PubMed1987

Effect of parental malnutrition on enzyme content of rat pancreas.

The aim of this study was to assess in rat pups the influence of protein diets ingested by their mothers during gestation and lactation on the enzyme content of the pancreas of the offspring. Rat pups born of either well-nourished mothers or of mothers fed a diet moderately restricted in protein (9% casein w/w) were studied. After weaning, the pups were fed on one of three diets: a well-balanced diet, a 5% casein diet (protein restricted), or a well-balanced diet of a similar caloric value as the protein-restricted diet (pair-fed rat pups). The pups were sacrificed after intervals of one to 25 weeks after weaning. The results showed that the enzyme content of the pancreas increased progressively with time in pups born of malnourished mothers, particularly in pups fed the protein-restricted diet. This suggests prolonged maturation of the pancreas. Pups fed the 5% casein diet had a decreased amylase content per milligram of DNA but not of other enzymes. Malnutrition in the mother increased the ratio of enzymes to DNA and the total pancreatic enzyme content at different times after weaning, indicating that maternal malnutrition had a prolonged effect on the pancreatic enzyme content of the pups' pancreas. This mechanism could play a role in the pathogenesis of tropical chronic calcific pancreatitis in man and explain some of the geographic differences in the incidence of the disease.

Amylases↗
PubMed1987

Protein-energy malnutrition in pregnant rats improves the adaptation of the endocrine pancreas in malnourished offspring and induces insulin resistance after rehabilitation.

1. In developing countries, malnutrition begins during pregnancy and lactation. Glucose intolerance is a problem of importance during protein-energy malnutrition (PEM). We therefore studied glucose homeostasis in rats weaned from undernourished mothers. 2. On weaning, 156 male Wistar rats, born from deprived mothers (75 g casein/kg diet), were fed ad lib on either a balanced diet (180 g casein/kg; group DR), or a protein-deficient diet (50 g casein/kg; group DD). At seven time intervals (weeks 0, 1, 3, 5, 8, 16 and 23) twelve rats were weighed, fasted overnight and then decapitated. Blood glucose, plasma insulin (IRI) and glucagon (IRG) levels and pancreatic insulin and glucagon contents were determined. 3. In DR and DD rats blood glucose, which was normal at weaning, dropped in the 1st week and then increased slowly. DR rats were hyperglycaemic from week 16. IRI continually increased during the experiment from near-normal values to hyperinsulinic levels in DR rats; in group DD, it remained stable until week 8 before increasing. IRG, which was very low at weaning, increased to normal levels in the 1st week in group DR; in group DD, it fell slightly during the study. Pancreatic hormone contents were much higher than after normal pregnancy and lactation. 4. We compared these results with those of a previous study with rats born from normal mothers: at weaning in the second experiment the rats were already well adapted to malnutrition. The plasma ratio IRI:IRG in DD rats showed two phases of adaptation: weeks 0-5 when glucose homeostasis did not change and weeks 5-23 when it became increasingly normal. At the end of the experiment DR rats still had a lower body-weight than normal rats but were insulin-resistant.

Adaptation, Physiological↗
PubMed1987

Nutrient homeostasis: long-term interrelations between pancreatic hormones, blood glucose and dietary wheat bran in men.

Postprandial plasma somatostatin (SLI), pancreatic glucagon, insulin (IRI) and blood glucose (BG) were measured at 0, 30, 60, 120 and 180 min after a test meal in 10 healthy men before and after 1, 3 and 7 wk of ingestion of a balanced diet supplemented daily with 20 g wheat bran. BG response to the test meal was significantly and consistently lower after the first week of consuming bran, with a maximum drop after 3 wk. After 1 wk of bran, when compared with the prebran values, SLI secretion was decreased, and glucagon response was significantly enhanced at 120 and 180 min after the meal. IRI secretion did not change significantly until the third week. After consuming bran for 7 wk, postprandial SLI concentrations returned to prebran values, and glucagon levels were not significantly different from those of the first meal. IRI during the fourth test meal (after 7 wk of bran consumption) was significantly higher than after the third meal (after 3 wk of bran ingestion), at 60 min and at 120 min. BG levels remained low. Chronic bran ingestion was therefore associated with an improved glucose tolerance. Its effects on pancreatic hormones varied with time for each hormone, and somatostatin was the only one to return to the prebran values.

Adult↗
PubMed1987

Psycho-social assessment of 36 de Lange patients.

Thirty-six de Lange patients aged 5-47 years with a median age of 16 years were tested by the Vineland Social Maturity Scale. Significant physical handicaps affecting the scoring were found in six patients. The social quotients varied from 2.2-99.5. Eighty-one per cent of the patients scored less than 52. Specific retardation was found in verbal communication. Other cognitive skills also showed low scoring, while the patients showed relatively high scores in self-help items. Fifteen patients lived in large institutions for the mentally retarded, three patients lived in hostels or boarding-schools, and one patient lived in her own home. Only two patients, both severely retarded, did not attend any regular daily activity. It is concluded that de Lange patients will not be able to live without support in the community, that they are particularly retarded in verbal communication but that they function relatively well in everyday self-help skills.

Activities of Daily Living↗
PubMed1987

The reduction in microfilariae loads in the skin and eye after nodulectomy in Ecuadorian onchocerciasis.

This study is concerned with the relationship between palpable onchocercal nodules and Onchocerca volvulus microfilarial loads in the skin. The number of microfilariae in clinically normal skin decreases as the distance from the nodule increases. Surgical removal of nodules reduces the microfilarial loads in 40 of 46 patients studied over a period of five months, with an average reduction of 65.4% of the prenodulectomy microfilarial load at the iliac crest. Complete elimination of detectable parasites was seen in some patients. Five individuals had increased microfilarial loads, all of which had developed new palpable nodules. Also, nodulectomy had a significant effect on ocular tissue, reducing the levels of parasites in the cornea and anterior chamber in 10 of 15 patients observed with no new nodules developing during the observation period. Both dermal and ocular clinical manifestations of onchocerciasis were reduced in a proportion of the patients. These parasitological and clinical findings provide evidence that nodulectomy is a beneficial procedure to O. volvulus infected patients in Ecuador by reducing both microfilarial loads and the degree of pathology.

Animals↗
PubMed1987

[Value of modern study methods in the early diagnosis and assessment of asbestosis].

Results of examinations among 31 asbestos-workers with pleural hyalinosis are presented. The hyalinosis was ascertained by means of pleuroscopy and computed tomography. The value of both methods and special function tests in asbestosis is discussed. Diagnostic and expertising of early signs in asbestosis should not rely on x-ray of thorax but include selected and suitable function tests.

Asbestosis↗