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Biomedical subjects

A Gutierrez

Publications and source records attributed to A Gutierrez.

At least 19 recordsLinked to original sources
PubMed1992

Hepatic vagotomy does not alter plasma insulin response to a low dose injection of glucose.

It has been reported that insulin concentration is altered by a hepatic vagotomy following intraperitoneal glucose injection (0.3 g/kg) resulting in supraphysiological blood glucose concentrations. On the other hand, neural activity of the hepatic vagus nerve has been shown to be substantially reduced by lower doses (0.05 g/kg intraportal; 0.1 g/kg intravenous). The present study was conducted in order to examine the role of the hepatic vagus nerve in insulin response after intraperitoneal injections of 0.1 and 0.3 g/kg of glucose. Measurements were made 5 days after section of this branch. In a first experiment, arterial glucose and insulin concentrations were not affected by the hepatic vagotomy following injections of either 0.1 or 0.3 g/kg of glucose. The same finding was also found in a second experiment in which portal glucose and insulin levels were measured after injection of 0.1 g/kg of glucose. These results suggest that large changes in neural activity are needed for the hepatic vagus nerve to influence the insulin response.

Animals↗
PubMed1992

Effects of exercise training on insulin response to intravenous glucose in pubertal rats.

This study was undertaken to evaluate the effects of exercise training on glucose tolerance and glucose-stimulated insulin response (GSIR) in 55- and 90-day-old peripubertal female rats. Intravenous glucose tolerance tests (0.5 g/kg) were done in: 1) 90-day-old rats exercised in swimming sessions for either 5 or 10 weeks and evaluated 48 h after the last exercise bout; 2) 55-day-old rats exercised for 5 weeks and evaluated either 24 h or 48 h after the last exercise bout and; 3) unexercised 55- and 90-day-old rats. The total area under the GSIR curve was suppressed in 55- and 90-day-old rats exercised since the age of 21 days. However, this decrease was observed 48 and only 24 h after the last exercise bout in the 90- and 55-day-old rats respectively. Exercise did not affect the GSIR curve for the 90-day-old rats subjected to 5 weeks of exercise training (started at 55 days of age) when evaluated 48 h after the last exercise bout. Nor did one single bout of swimming exercise (2 h) in the last 24 h affect the GSIR in unexercised 55-day-old rats. These results suggest that the shorter duration of the residual effects of exercise in the younger rats (55 days) was related to the shorter length of the training programme. Body weight was not significantly reduced with exercise in 55-day-old rats, whereas the same amount of exercise in 90-day-old rats caused body weight reduction of approximately 35 g (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

APL program for evaluation of heat processes for spherical foods.

The present program solves the heat transfer equations for spherical foods by a numerical procedure that uses the Crank-Nicolson method. The program is implemented for conditions with as few restrictions as possible to enhance versatility. The results agree with the analytical solutions for two particular cases of boundary conditions. The program also computes the thermal effect in the foodstuff from the temperature data obtained by the numerical program.

Algorithms↗
PubMed1992

Influence of a meat-free diet on the urinary excretion of 3-methylhistidine and creatinine in chronic renal failure.

Urinary excretion of 3-methylhistidine has been proposed as an index of internal protein breakdown provided that the intake of exogenous 3-methylhistidine (meat) is excluded. To evaluate the potential use of 3-methylhistidine in the metabolic assessment of patients with advanced renal failure, we studied a group of 11 patients with markedly reduced renal function who were put on a meat-free diet (the protein intake was kept constant). Steady-state plasma concentration and urinary excretion of 3-methylhistidine were not achieved until 14 d after exclusion of meat from the diet. At that time the plasma concentration and urinary excretion of 3-methylhistidine had decreased by 43% and 60%, respectively. We conclude that the delay in reaching steady state makes the clinical use of urinary excretion of 3-methylhistidine in patients with advanced renal failure unpracticable as an index of protein breakdown. The exclusion of meat also resulted in a continuous decrease in the plasma level and urinary excretion of creatinine, with the result that plasma creatinine or its reciprocal become misleading for evaluation of changes in renal function until a new steady state has been reached.

Adult↗
PubMed1992

Effect of physical training on insulin response to intravenous glucose in male peripubertal rats.

This study was undertaken to evaluate the effects of regular endurance-type exercise (i.e., swimming) on glucose tolerance and glucose-stimulated insulin response (GSIR) in 55- and 90-day-old peripubertal male rats. Intravenous glucose tolerance tests (0.5 g/kg) were done in four groups of male Sprague-Dawley rats: two groups of trained (TR; 55- and 90-day-old) and two groups of age- and weight-matched untrained (UNTR) rats. The UNTR rats were subjected to a continuous food restriction to maintain body weights equal to those of the TR rats. Rats were received in our laboratory after weaning at 21 days of age and were evaluated 48 h after the last exercise bout. No significant differences in body weights were found between TR and UNTR rats, at the age of either 55 or 90 days. A significant (P < 0.01) decrease in the mean integrated area under the glucose and insulin curves was observed in TR compared with UNTR groups in 55- as well as 90-day-old rats. These results indicate that exercise training in male rats improves the glucose tolerance and GSIR before and during puberty (21-90 days) independently of a reduction in body weight gain.

Animals↗
PubMed1992

[Two-dimensional and Doppler echocardiography in the non-invasive diagnosis of coronary cardiac fistula].

Two asymptomatic children with an atypical continuous murmur and a clinical diagnosis of coronary artery fistula are reported. Cross-sectional and Doppler echocardiography led to the diagnosis of a right coronary artery-right ventricule fistula in both cases, which was confirmed by coronary angiography. Surgical closure of the fistula was realized without complications.

Arteriovenous Fistula↗
PubMed1992

Protein catabolism in sham-hemodialysis: the effect of different membranes.

To study whether the contact between dialysis membrane of various materials and blood may trigger protein catabolism in muscle and thus contribute to protein depletion in hemodialysis patients we measured the exchange of free amino acids across the leg in healthy subjects undergoing sham-hemodialysis (i.e. in vivo passage of blood through a dialyzer without circulating dialysate). The effect of dialyzers with regenerated cellulose (group CU, n = 16), cellulose acetate (group CA, N = 8) and polysulfone membranes (group PS, n = 8), respectively was studied. Plasma amino acid concentrations were measured in arterial and femoral venous blood and leg blood flow was determined by venous occlusion plethysmography. In group CU the total efflux of all measured amino acids from leg tissues (muscle) increased from 167 +/- 21 nmol/min/100 g tissue in the basal state to 308 +/- 41 nmol/min/100 g tissue at 345 minutes after the start of sham-hemodialysis procedure (p less than 0.01) indicating a protein catabolic effect of contact between blood and regenerated cellulose membranes. In contrast sham-hemodialysis in group CA and group PS, respectively, did not result in significant increases in amino acid efflux from the leg implying that the protein catabolic effect of blood membrane contact depends on the chemical properties of dialysis membranes. In group CU sham-hemodialysis resulted in enhanced net protein breakdown. Increases in arterial concentrations and leg release of 3-methylhistidine suggest that this may be due primarily to increased protein breakdown.

Adult↗
PubMed1992

Granulocyte elastase, beta-thromboglobulin, and C3d during acetate or bicarbonate hemodialysis with Hemophan compared to a cellulose acetate membrane.

Twenty-two patients were dialysed in a cross-over design using Hemophan or cellulose acetate membranes. The dialysate buffer was acetate (n = 12) or bicarbonate (n = 10). Blood was sampled at 0, 15, 60 and 180 min and mean values were adjusted for changes in total protein in each sample. At 15 min during dialysis a decrease in leukocytes and platelets occurred with both membranes, irrespective of the buffer (Wilcoxon, p less than 0.006). During dialysis, increases were found in granulocyte elastase inhibitor complex (E- alpha 1-PI), beta-thromboglobulin and C3d. beta 2-microglobulin was not significantly changed in blood after dialysis with Hemophan or cellulose acetate membranes with bicarbonate buffer. Side effects were more pronounced at 180 min during dialysis with bicarbonate in patients using cellulose acetate than with Hemophan (p = 0.021, n = 8). Hemophan seemed to be more favourable than cellulose acetate membranes in regard to leukopenia and E- alpha 1-PI. The dialysate buffer may also alter membrane biocompatibility.

Biocompatible Materials↗
PubMed1990

Effect of in vivo contact between blood and dialysis membranes on protein catabolism in humans.

To investigate whether the contact between blood and dialysis membranes might induce muscle protein degradation, the exchange of free amino acids across leg tissues was measured by catheterization technique in three groups of healthy subjects before and after a 150 minute sham-hemodialysis procedure (SHDP), that is, in vivo passage of blood (100 ml/min) through a dialyzer but with no circulating dialysate. Dialyzers with either regenerated cellulose membrane (group CU, N = 10 and group CU-IND, N = 6) or polyacrylonitrile membrane (group AN, N = 8) were used in group CU-IND indomethacin was administered before (100 mg) and at the end (50 mg) of SHDP. Leg blood flow was measured by venous occlusion plethysmography. In group CU net leg release of tyrosine and phenylalanine increased from 3.4 +/- 0.8 and 3.6 +/- 0.8 nmol/min/100 g tissue, respectively, before SHDP to 7.8 +/- 1.8 and 8.3 +/- 1.8 nmol/min/100 g tissue, respectively, at 345 minutes after the start of SHDP (P less than 0.01). The total release of all measured amino acids increased from 148 +/- 31 to 309 +/- 50 nmol/min/100 g tissue (P less than 0.01). The results indicate that interaction between blood and regenerated cellulose membranes leads to accelerated net protein breakdown. In group CU-IND no change in leg amino acid release was observed following SHDP, suggesting that the increased net protein catabolism is mediated by prostaglandins. Sham hemodialysis using AN membranes did not result in increased amino acid efflux from leg tissues, implying that the protein catabolic effect of blood-membrane contact depends on the biochemical properties of dialyser.

Acrylic Resins↗
PubMed1989

Repeated application of EMLA cream 5% for the alleviation of cannulation pain in haemodialysis.

The analgesic effect and the occurrence of local reactions after repeated application of a lidocaine/prilocaine cream (EMLA 5%) were investigated in 31 haemodialysis patients. The cream was used for alleviation of cannulation pain prior to the haemodialysis (HD) for a period of 1-1.5 years. In each patient 300 to 312 applications of the cream were made during the period. Local skin reactions were recorded after the cream applications and the analgesic effect was evaluated with double-blind, crossover placebo controls at regular intervals. Seventeen patients completed the study. EMLA gave considerable pain relief and was significantly better than placebo at all effect evaluations but one. The frequency of local reactions was low and not correlated to the number of applications of EMLA. Two patients, however, interrupted their treatment due to local irritation.

Aged↗
PubMed1989

Stockholm clinical study on progression of chronic renal failure--an interim report.

Fifty-seven patients with chronic renal failure (CRF) of diverse etiology entered a prospective, randomized study to evaluate the effect of a low protein diet on the progression rate of CRF. All patients were followed for a control period of 12 or 24 months before randomization into two groups, one permitted unrestricted protein intake and the other prescribed a diet containing 0.4 g/kg body wt/day of protein and 0.1 g/kg body wt/day of essential amino acids, (LPD + EAA). During both the control and study periods, patients were clinically evaluated and had serum biochemistry and 24-hour clearance of creatinine, urea and protein excretion checked monthly. The 51Cr-EDTA clearance (plasma slope and urinary clearance) was determined every third month. The progression of renal failure was evaluated from the regressions of the reciprocal of serum creatinine (SCr-1), creatinine clearance and urinary 51Cr-EDTA clearance against time. Having defined criteria for progression, only patients in whom renal failure had progressed over 12 or 24 months were randomized. In 28 patients, data were available, permitting a comparison of the progression of renal failure (estimated from regression of SCr-1 and of creatinine clearance against time) during the retrospective and prospective periods. There was a significant correlation between the change in progression rate and the change in mean arterial pressure, a relationship which was also present in patients with mild hypertension or those with blood pressure within the "normal" range. The urinary protein excretion also correlated with the change in mean arterial pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Bilateral single ectopic ureter.

A case of single bilateral ureteral ectopia is presented. Patient underwent bilateral ureteral reimplantation with right ureteral tailoring, with a satisfactory result.

Child, Preschool↗
PubMed1988

Reduction of blood pressure retards the progression of chronic renal failure in man.

The effect of blood pressure reduction on the progression rate of chronic renal failure (CRF) was studied in 28 patients with CRF of diverse aetiology entering a prospective study (observation time 7-24 months, mean 16 months). Endogenous creatinine clearance was 12-66 ml/min (mean 30 +/- 3 ml/min). We aimed to keep the blood pressure below 160/90 mmHg. Dietary protein was not restricted. The progression rate of CRF was assessed from the regression coefficients of the regressions of creatinine clearance and the inverse of s-creatinine, respectively, on time. Progression rate and the means of all recordings of mean arterial blood pressure (MAP) and urinary protein excretion, respectively, in each patient during the prospective phase were compared with retrospective data from the proceeding period (observation time 4-25 months, mean 19 months). The patients received various combinations of antihypertensive drugs including diuretics, beta-blockers and vasodilatory drugs. In 19 patients MAP decreased from 109 +/- 2 to 102 +/- 2 mmHg (group I), whereas MAP increased from 105 +/- 2 to 108 +/- 2 mmHg in nine patients (group II). In group I proteinuria was significantly lower (P less than 0.05) and the progression of CRF was approximately 50% slower (P less than 0.01) in the prospective phase than in the retrospective phase; no changes were observed in group II. Calculated for all patients, significant correlations were observed between the change in MAP and the change in progression rate and protein excretion, respectively. These results indicate that lowering of blood pressure results in decreased proteinuria and retardation of the progression of CRF irrespective of the aetiology.

Adult↗