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Biomedical subjects

R Montes

Publications and source records attributed to R Montes.

46 records · Page 3Linked to original sources
PubMed1993

EMG biofeedback of the abductor pollicis brevis in piano performance.

The aim of the present study was to apply EMG biofeedback as an auxiliary to piano teaching techniques. We studied the changes in integrated electromyographic activity, using the abductor pollicis brevis functioning as an agonist during the teaching of identical selective movements of piano playing in two groups, one with EMG biofeedback and the other following traditional method of instruction. The analysis of variance revealed an increase in the peak amplitude and the relaxation rate values for the biofeedback group. These results have implications for the application of piano playing techniques and reveal EMG biofeedback as an aid in the teaching of thumb attack with the abductor pollicis brevis as agonist.

Adolescent↗
PubMed1992

[Thrombin-antithrombin complexes and F1+2 prothrombin fragment in coronary revascularization surgery. Relationship with graft occlusion].

PURPOSE: To evaluate the possible role played by activation of the coagulation system in the early occlusion of grafts in patients subjected to aortocoronary bypass. PATIENTS AND METHODS: This study includes 30 patients subjected to coronary revascularization surgery. The plasma rates of thrombin-anti-thrombin complexes (TAT) and 1+2 prothrombin fragments (F1+2) were measured before and after surgery. The studies were performed by enzyme immunoassay techniques. Selective angiography was performed in every patient on the 10th day after surgery. Descriptive statistics, Student's t test and Mann-Whitney U test were used for comparison of means ans statistical analysis. RESULTS: Occlusive lesion was shown by angiography in 15 of the 30 patients. The TAT and F1+2 levels showed a statistically significant increase (p less than 0.001) along the postoperative period, without any correlation regarding the presence or absence of occlusion. The preoperative concentration of TAT was significantly higher in patients with thrombotic occlusion (p less than 0.05). CONCLUSIONS: 1) Marked activation of the coagulation system is present in patients subjected to coronary revascularization surgery. 2) The pre-operative determination of TAT may be of value for predicting early graft occlusion.

Aged↗
PubMed1990

Efferent mechanisms mediating renal sodium and water excretion induced by centrally administered serotonin.

Treatments that increase central extracellular serotonin (5-HT) also increase Na excretion. Efferent renal sympathetic nerve activity (ERSNA) contributes to the control of Na and water reabsorption. To determine whether renal nerves play a role in the 5-HT-induced natriuresis, we examined the effect of intracerebroventricular (icv) injection of vehicle or 5-HT (20 micrograms) on Na, K, and urine excretion rates, as well as mean arterial pressure and heart rate in unanesthetized, hydrated rats with renal nerves intact or sectioned. Renal denervation attenuated the natriuresis produced by 5-HT but not the antidiuresis observed 15-30 min after injection. Central 5-HT produced brief pressor and bradycardic responses, followed by continued bradycardia and hypotension, which were more pronounced in intact rats. In other experiments, circulating levels of arginine vasopressin (AVP) and plasma atrial natriuretic polypeptide (ANP) were measured 15 min after icv injection of 5-HT. 5-HT significantly increased circulating AVP, but plasma ANP remained unchanged. These results suggest that renal nerves participate in the natriuresis elicited by centrally administered 5-HT through a decrease in ERSNA. The antidiuresis observed after central 5-HT may be due to an increase in AVP release.

Animals↗
PubMed1986

Adipsia-polydipsia induced by simultaneous lesion of the medioventral septum and anteroventral third ventricle area in the rat.

The medioventral septal area (MVS) and also the tissue surrounding the periventricular preoptic-hypothalamic region (AV3V) of male rats, were destroyed by mean of electrolytic lesions. Before and after the lesions, daily water and food intakes, diuresis, body weight, urine osmolarity, and sodium and potassium excretion were determined. Rats with simultaneous AV3V-MVS lesions showed a biphasic pattern of drinking behavior characterized by a first period of adipsia followed by another period of polydipsia. During the first period of adipsia and except for the first two days, postlesion rats were able to reduce total urine volume but failed to produce an appropriate concentrated urine. During the polydipsia period, on the contrary, rats increased urine output and decreased urine osmolarity in a parallel fashion. Immediately after the lesion, food intake was decreased but recovered to pre-lesion levels gradually. By contrast, body weight was decreased during the entire period of the experiment. Sodium but not potassium excretion showed a significant increase from the 9th to the 20th day postlesion. The results suggest that the AV3V and MVS are part of a circuitry subserving the control of water intake and electrolyte balance.

Animals↗
PubMed1981

Effect of insulin on acetate metabolism in chicken adipocytes.

The effects of insulin on the metabolism of acetate-U-14C in isolated chicken adipocytes have been investigated. Insulin added in vitro at physiological concentrations did not stimulate the incorporation of acetate-U-14C into triglycerides or CO2 when the acetate was present alone. In the presence of glucose 11m M, however, insulin stimulated significantly lipogenesis from acetate. This is an indirect action mediated by glucose.

Acetates↗
PubMedDate not supplied

Direct detection of thermotolerant campylobacters in chicken products by PCR and in situ hybridization.

We have evaluated the use of PCR and fluorescent in situ hybridization (FISH) techniques for the detection of thermotolerant campylobacters in naturally contaminated chicken products. 16S rRNA sequence data was used to design two specific primers and an oligonucleotide probe for PCR and FISH analyses, respectively. The PCR protocol amplified a 439-bp fragment corresponding to a portion of specific 16S RNA gene from thermotolerant campylobacters. The detection range of the PCR assay varied between 10 cells (after enrichment) to 10(2) cells per mL (without enrichment). FISH probes were able to identify thermotolerant Campylobacter species in 'spiked' and 'unspiked' naturally contaminated samples. PCR and FISH were performed on naturally contaminated samples and compared with the isolation of cells on selective media. The in situ hybridization technique was less sensitive than PCR, although its sensitivity of detection was increased considerably after 22 h of enrichment. These results confirm the usefulness of 16S rRNA-based techniques for the direct detection of campylobacters in food samples.

Animals↗