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Biomedical subjects

R Gross

Publications and source records attributed to R Gross.

At least 343 records · Page 19Linked to original sources
PubMed1983

[Phenotypic and technological influences of the Lupinus mutabilis (Tarwi) seed on its methionine availability and sulfur content].

The present study was carried out to determine the content of available methionine and sulphur in seed cultivars of Lupinus mutabilis from different Andean regions, and to study the influence of processing on methionine and sulphur contents. An additional objective was to evaluate interrelationships among these chemical characteristics and protein quality, as measured by the protein efficiency ratio (PER) method. Results revealed a high variability in the content of available methionine and sulphur between the different ecotypes and varieties of Lupinus mutabilis. Fertilization with CaSO4 (200 kg/ha) did alter the content of available methionine and sulphur in Lupinus albus seeds. Traditional water-debittering of lupines did not affect the methionine content of the seeds, whereas oil-extraction and alcohol-debittering led to a decrease in available methionine (14 and 23% reduction, respectively). Production of a protein isolate further reduced the methionine content (54%). Regression analysis revealed a high correlation between available methionine and sulphur (r = 0.83), between sulphur and PER (r = 0.98) in the processed lupine samples, and lupine mixtures with other protein sources.

Fabaceae↗
PubMed1983

[Comparison of 4 methods of evaluating protein quality in vegetable sources].

This study compares the practical value of the following methods: protein efficiency ratio (PER), blood urea concentration in rats (BUC), relative nutritive value (RNV), and predicted protein value (PPV) to evaluate the protein quality of 41 diets of plant origin. Results demonstrated low correlations between PER and RNV (r = 0.66), PER and PPV (r = 0.53), RNV and PPV (r = 0.54), whereas there was a high negative correlation between PER and BUC (r = -0.89). These different procedures can be useful and valid for distinct and well-defined objectives, but the evaluation of results must be made in accordance with the purpose of the experiment. In assessing the protein quality of foodstuffs, it is therefore recommended that mathematical computer models be developed which take into account the cybernetic system of the amino acid metabolism. This would definitely reduce the actual need of expensive long-term biological assays.

Amino Acids↗
PubMed1982

Cyanide toxicity of sodium nitroprusside in therapeutic use with and without sodium thiosulphate.

Sodium nitroprusside (SNP) as a mono-infusion was administered to 51 patients for periods of a few hours. A further group of 19 patients received SNP for periods of several days as a combination solution of SNP mixed with sodium thiosulphate. The concentrations of cyanide and of thiocyanate in the blood of all patients were measured. In seven of the patients the level of thiosulphate was also measured. Infusion of SNP on its own at levels exceeding 2 microgram/kg/min led to the rising of cyanide levels in the blood being proportional to dosage. Infusion of SNP mixed with thiosulphate showed no such accumulation of cyanide in any patient, irrespective of dosage level and duration. The efficacy at lowering blood pressure was fully maintained in the mixed infusion. The elimination half-life for thiosulphate was 16.5 min. Pharmacokinetic calculation of the rise in cyanide level showed that mono-infusions of 5-10 micrograms SNP/kg/min could within 5-10 h cause a life-threatening cyanide level in the blood. By contrast, mixed infusion of SNP together with thiosulphate, for which light-opaque syringes and tubing must be used, is a procedure free of danger and should become the technique of choice when therapeutically administering SNP in order to lower blood pressure.

Adolescent↗
PubMed1982

[Chemotherapy schedule for the management of metastasizing gastric cancer. Methotrexate, adriamycin and 5-fluorouracil].

The possible effectiveness of methotrexate, 5-fluorouracil and adriamycin was tested in a phase I/II study of patients with metastasising gastric carcinoma. complete of partial remission occurred in 19 of 30 patients (approximately 63%). Two of 30 patients had complete remission. Median survival time of patients with remission cannot as yet be determined: about 68% are still alive after 17 months. Median survival time of patients with advanced tumour was only five months. The difference in survival curve is statistically significant (P less than 0.05). The study is continuing.

Adult↗
PubMed1982

[Treatment of acute leukemias].

The effective treatment of acute (myeloblastic and lymphoblastic) leukaemias depends on the induction of remissions as well as on the maintenance of these remissions. Whereas the use of anthracyclines and of cytosine arabinoside in different combinations notably increased the rate of induction of remissions, their maintenance was less successful until now. We present a scheme using, beside MTX and 6-MP, modified COAP regimes periodically every 3 months. The follow-up of 26 patients treated in this way is encouraging since nearly one third remained in full haematological remission after 3 years of observation.

Adolescent↗
PubMed1982

Beta adrenergic receptors mediated effects, insulin and plasma free fatty acids in the duck.

Beta-adrenergic blockade by IV propranolol treatment (5 mg/kg), resulted in an important drop in plasma immunoreactive insulin (IRI) in normal 24-hour fasted ducks, indicating that basal insulin secretion is controlled by beta-adrenergic receptors. Concomitantly plasma free fatty acids (FFA) are doubled; this effect is suppressed in animals made insulin-deficient by total pancreatectomy or hypophysectomy and in normal animals when the drop of plasma IRI is prevented by simultaneous administration of insulin. These results show that insulin, considered as devoid of any direct actin on lipolysis in birds, does play a role in plasma FFA regulation in the duck and confirm previous studies on totally pancreatectomized animals. This effect was also observed in fed animals in which propranolol, by decreasing plasma IRI to fasting levels, brings back plasma FFA to values observed in fasted ducks. Furthermore, propranolol, by impairing the hypoglycaemia of hypophysectomized or totally pancreatectomized animals suggest that effects mediated by beta-adrenergic receptors play a direct role in the regulation of plasma glucose level in the duck. Finally, glucose administration in propranolol treated animals show that the beta cell becomes insensitive to glucose in the absence of a normal beta adrenergic stimulation. This is not the case in A cell which remains responsive to hyper- and hypoglycaemia.

Adrenergic beta-Antagonists↗
PubMed1982

Modulation by the nutritional state of adrenergic receptor mediated effects on insulin secretion in ducks.

The effects of exogenous (IV Norepinephrine (NE)) and endogenous alpha adrenergic activity (IV phentolamine (PH)) were studied in the duck. Our aim was first to compare their importance in animals fed for 1 1/2 hours and fasted for 24 and 48 hours, and then to assess the relative importance of alpha versus beta adrenergic receptor mediated effects during the development of a 48-hour-fast. NE reduces plasma IRI levels after a fast but not in the postprandial state. PH while ineffective in animals fed for 1 1/2 hours brings fasting IRI values to levels observed in the former group. Twenty-four hour fasted ducks are sensitive to both alpha adrenergic stimulation and beta adrenergic blockade which have additive effects; so, insulin secretion is controlled by 2 distinct mechanisms: a beta stimulating and an alpha inhibiting one. The importance of one component versus the other is modulated by the nutritional state: indeed, a double alpha and beta equimolar adrenergic blockade reveals that during the transition from the postprandial state to a 48-hour-fast, there is a progressive reversal in the importance of one adrenergic component versus the other. The effects of alpha adrenergic stimulation or blockade occur independently of simultaneous glucose variations. This is not the case for A cell function: an alpha adrenergic receptor stimulating effect on glucagon secretion exists, but A cell remains primarily sensitive to plasma glucose level. alpha Adrenergic activity has no direct effect on plasma free fatty acids (FFA) level but plays a role in plasma glucose level regulation especially in animals in the postprandial state.

Animals↗
PubMed1982

Composition and protein quality of Lupinus mutabilis.

The chemical composition and the protein quality of three samples of Lupinus mutabilis (a raw, semi-sweet variety; cooked, water-extracted seeds; and alcohol-extracted oil cake) were studied. The protein content varied from 47.7% dry weight (raw seeds) to 65.3% (oil-cake). Compared to the FAO reference pattern sulfur- containing amino acids are first limiting. The water-extracted sample contained 26.9% oil and the polyunsaturated/saturated fatty acid ratio of 30 seed samples was 5.3. Alkaloid content of raw seed was high (3.3%), but could be reduced or nearly eliminated by water-and-alcohol extraction or plant breeding. Other anti-nutritive substances were present only in trace quantities. Protein quality measured as protein efficiency ratio (PER) gave low values for the non-supplemented lupin proteins (1.34 semi-sweet variety; 1.53 water-extracted seeds; 1.19 oil-cake; 3.09 casein), but the PER's were improved by the addition of 0.2% DL-methionine to the diets (3.05, 2.69, 2,81, respectively). Raw as well as processed lupin protein showed an excellent apparent digestibility (80.0-85.8%, casein 87.1%). Studies of net protein utilization (NPU) and biological value (BV) confirmed the importance of methionine supplementation, The true digestibility of 92% was equivalent to that of casein.

Alkaloids↗
PubMed1981

Selenium and myocardial infarction: glutathione peroxidase in platelets.

The activity of the selenoenzyme glutathione peroxidase (EC 1.11.1.9) was determined in platelets of 15 patients with acute myocardial infarction and 13 control subjects. The platelets of the patients had significantly lower activities of the enzyme (P(t) greater than 0.99). This may be related to the pathogenesis of the disease.

Adult↗