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Biomedical subjects

R Gross

Publications and source records attributed to R Gross.

At least 361 records · Page 20Linked to original sources
PubMed1981

Effect of insulin on glucagon secretion mediated via glucose metabolism of pancreatic A cells in ducks.

A possible action of insulin via glucose metabolism on the pancreatic A cell response to glucose, was studied in ducks. 2-Deoxyglucose, a nonmetabolizable analogue of glucose was used. In normal ducks, the hyperglycaemia induced by 2-deoxyglucose (IV: 0.5 g/kg) resulted in hyperglucagonaemia, while the same degree of hyperglycaemia, induced by glucose infusion (IV injection 25 mg/kg, and infusion 5 mg/kg/min) immediately suppressed glucagon secretion. In diabetic ducks, two days after subtotal pancreatectomy, glucose responsiveness of the A cell was abolished, but could be restored by insulin treatment before (IM 0.2 U/kg insulin + 8 micrograms/kg glucagon every 6 h) and during (IV 3.6 mU/kg + infusion 0.9 mU/kg/min) the glucose test (IV: 0.5 g/kg). The normal response of the A cell to glucose was not observed in diabetic insulin-treated ducks after the administration of 2-deoxyglucose (IV: 0.5 g/kg). These data suggest an inhibitory effect of the metabolism of glucose on the release of glucagon. In addition, the action of insulin on the A cell may be mediated by its effect on glucose metabolism within the A cell.

Animals↗
PubMed1981

In-patient community meetings: problems and purposes.

The role of the in-patient community meeting is discussed in relation to the general difficulty of attributing specific effectiveness to any type of therapeutic activity on an in-patient service. Close scrutiny of such units demonstrates that staff and patients are composed of several heterogeneous subgroups, not all of whom share common attitudes and values or benefit from similar activities. Within this framework the major problems as well as functions of the community meeting are discussed. Specific questions which await investigation with clinical research are elaborated.

Attitude of Health Personnel↗
PubMed1981

Interaction between perfusion pressure and sympathetic nerves in renin release by carotid baroreflex in conscious dogs.

1. The effect of bilateral carotid occlusion on carotid sinus pressure, systemic blood pressure, heart rate, renal blood flow, renal-venous and arterial plasma renin activity was studied in twelve trained conscious foxhounds on a normal sodium diet (4.7 mmol/kg per day). 2. When renal perfusion pressure was allowed to rise with systemic pressure by 51.0 +/- 6.3 mmHg during carotid occlusion, renin release decreased by 72.3 +/- 22.2 ng/min (78% of control; P less than 0.05) while renal blood flow remained at its resting level of 232.7 +/- 20.1 ml/min (n = 8 dogs). 3. When renal perfusion pressure was maintained constant at 93.0 +/- 3.6 mmHg during carotid occlusion (suprarenal aortic cuff), renin release increased by 154.6 +/- 60.4 ng/min (73% of control; P less than 0.05), again there was no significant change of renal blood flow (n = 7 dogs). 4. After beta-adrenergic blockade carotid occlusion increased systemic blood pressure by 47.7 +/- 7.8 mmHg, decreased renin release by 34.6 +/- 9.9 ng/min (67% of control; P less than 0.05) and had no effect on renal blood flow (n = 4 dogs). 5. When renal perfusion pressure was controlled at its resting level, no significant change of renin release and renal blood flow was observed during carotid occlusion in the surgically denervated kidney (n = 3 dogs) or in the intact kidney after beta-adrenergic blockade (n = 4 dogs). 6. It is concluded that a reduction of carotid sinus pressure in the conscious dog increases renin release by a direct beta-adrenergic stimulation without exerting vasomotor effects provided renal perfusion pressure is maintained at control level. The vascular receptor mechanism can effectively counteract the stimulating influence of the renal sympathetic nerves when perfusion pressure is allowed to rise.

Animals↗
PubMed1981

Effect of carotid occlusion and of perfusion pressure on renal function in conscious dogs.

We studied the effect of bilateral common carotid occlusion (implanted pneumatic cuffs) on renal blood flow (electromagnetic flowmeter) and renal function (implanted ureteral catheter) in nine chronically instrumented, conscious dogs on a high sodium diet (14 mmol/kg body weight per day). By means of suprarenal aortic constriction (pneumatic cuff) the influence of renal perfusion pressure was investigated. There was no change in renal blood flow or glomerular filtration rate (inulin clearance) with either reflexly increasing (+49.6%) or constant renal perfusion pressure. Carotid occlusion caused an increase of urine output by 80.5% and of sodium excretion by 85.3% due to a fall in fractional sodium reabsorption (-0.9%) when renal perfusion pressure was allowed to rise. Neither an increase of diuresis or sodium excretion nor an antinatriuresis was observed when renal perfusion pressure was kept constant during carotid occlusion. We conclude that, in conscious dogs at rest, the moderate sympathetic activation associated with carotid occlusion is too small to induce renal sympathetic vasoconstriction or antinatriuresis. The "carotid sinus polyuria" is a pressure-diuresis.

Animals↗
PubMed1981

A graphic approach for prediction of arterial oxygen tension at different concentrations of inspired oxygen.

A rapid, simple method for predicting the arterial oxygen tension (PaO2) at any fractional concentration of inspired oxygen (FIO2) is presented. The method is based on a nomogram interrelating PaO2, arterial carbon dioxide tension (PaCO2) and FIO2, allowing rapid determination of the arterial to alveolar oxygen tension ratio a/A PO2. The applicability of the nomogram and its reliability for predicting the PaO2 at any FIO2 were studied prospectively in nine consecutive patients requiring mechanical ventilation (16 trials). On each occasion, a desired PaO2 was chosen and from the nomogram an FIO2 expected to yield this PaO2 was administered. The PaO2 was then measured. Actual PaO2 differed from desired PaO2 by a mean of 2.6 mm Hg (range 0 to 10 mm Hg, standard deviation (SD) 4.8). Retrospectively, we analyzed the nomogram's ability to predict the PaO2 +/- 9.6 mm Hg (2 SD) at varying FIO2. The overall sensitivity of this method was 85 percent (126 predictions out of 149 trials). We conclude that appropriate levels of supplemental oxygen can be rapidly and reliably chosen using the nomogram in selected patients.

Adult↗
PubMed1981

The influence of patient-practitioner agreement on outcome of care.

A previous study suggested that patient-practitioner agreement and follow-up in ambulatory care facilitates problem resolution as judged by patients. In this study in another medical practice, practitioner-patient agreement on what problems required follow-up was associated with greater problem resolution as judged by the practitioners regardless of the severity of the problems. In this study, patients did not judge problems mentioned only by themselves to be less improved than problems mentioned by both them and their practitioners. However, in this study more of the problems mentioned only by patients were mentioned in the note of the visit contained in the medical record. Patients expected less and reported less improvements of problems that were neither mentioned by the practitioner nor written in the medical record than was the case for problems listed both by patients and practitioners. The findings of this study confirm those of the previous study in suggesting that practitioner-patient agreement about problems is associated with greater expectations for improvement and with better outcome as perceived by patients. In addition, they indicate that practitioners also report better outcome under the same circumstances.

Adult↗
PubMed1981

[Establishment of optimal conditions at laboratory and pilot plant levels for the preparation of a protein isolated from Lupinus mutabilis].

Laboratory conditions were first investigated to determine are optimum processing parameters for the preparation of a protein isolate from the ground, defatted, commercial flakes of Lupinus mutabilis. The extraction variables were: pH (2-10); solvent to lupine ratio (5:1 to 40:1); temperature (28 degrees C - 60 degrees C) and time (10-50 min). The isoelectric point of the lupine protein was found to be pH 4.5 with a protein solubility higher than 80% above pH 8.0. Using 70-100 mesh, ground defatted flakes, and extracting at pH 8.7 for 60 min, a protein isolate was obtained on acidification to pH 4.5 which was 99.8 protein (dry basis), compared to 55.25% protein for the original material. This protein isolate represented 32% of the initial material and 57.6% of the initial nitrogen. When making pilot plant assays we found that the yield of protein isolate decreased to 20.4% of the original material and 36.4% of the initial nitrogen. The protein efficiency ratio for the protein isolate was 2.15 when supplemented with methionine, and had a digestibility of 89.33

Amino Acids↗
PubMed1980

The relationship of sex role to self-concept.

Investigated the relationship of sex role in 136 Ss as measured by the Bem Sex Role Inventory to measures of self-concept and overt anxiety. Persons who rated themselves low in both masculine and feminine attributes were found to have significantly poorer self-concept than both androgynous and masculine Ss, which suggests that this group should be distinguished from high-high scorers labeled as androgynous. There was no significant difference in self-concept between masculine and androgynous Ss, and the masculine group reported significantly lower levels of anxiety. These findings support a previous contention that it is the presence of masculine attributes rather than a balance of masculinity and femininity that is crucial to personal adjustment.

Adult↗