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Biomedical subjects

J A Neto

Publications and source records attributed to J A Neto.

15 recordsLinked to original sources
PubMed2001

Electron spin relaxation via vibronic level of rhodium(II) hexacyanide complex in KCl crystal.

Electron spin-lattice relaxation rates for the low-spin [Rh(CN)(6)](4-) complex in KCl were measured by the inversion recovery and saturation recovery techniques, in the range of 5 to 30 K. Angular variation experiments indicate that electron spin-lattice relaxation times present axial symmetry. The data fit very well to a relaxation process involving localized anharmonic vibration modes, also responsible for the g tensor temperature dependence.

Journal Article↗
PubMed1999

Laparoscopic colorectal procedures: a multicenter Brazilian experience.

An evaluation of the results of the Brazilian experience in colorectal laparoscopic procedures in a multicenter prospective protocol done by the Brazilian Society of Colo-Proctology is presented. From December 1991 to August 1998, 1,161 patients (583 men and 578 women; mean age, 49.8 years), were operated on laparoscopically. Most of the procedures (40.5%) were for cancer, and the most common procedure was anterior resection (22.5%). The mean operative time was 189 minutes (3.1 hours). There were 42 (3.6%) perioperative complications; visceral injuries were the most common (1.4%). Conversions occurred in 122 (10.5%) cases. There were 148 (12.7%) postoperative complications; wound infections were the most common (5.2%). A liquid diet was started at a mean time of 1.4 days after the operation, and the mean hospitalization period was 6.4 days.

Adult↗
PubMed1988

Phosphofructokinase from bumblebee flight muscle. Molecular and catalytic properties and role of the enzyme in regulation of the fructose 6-phosphate/fructose 1,6-bisphosphate cycle.

Phosphofructokinase from the flight muscle of bumblebee was purified to homogeneity and its molecular and catalytic properties are presented. The kinetic behavior studies at pH 8.0 are consistent with random or compulsory-order ternary complex. At pH 7.4 the enzyme displays regulatory behavior with respect to both substrates, cooperativity toward fructose 6-phosphate, and inhibition by high concentration of ATP. Determinations of glycolytic intermediates in the flight muscle of insects exposed to low and normal temperatures showed statistically significant increases in the concentrations of AMP, fructose 2,6-bisphosphate, and glucose 6-phosphate during flight at 25 degrees C or rest at 5 degrees C. Measuring the activity of phosphofructokinase and fructose 1,6-bisphosphatase at 25 and 7.5 degrees C, in the presence of physiological concentrations of substrates and key effectors found in the muscle of bumblebee kept under different environmental temperatures and activity levels, suggests that the temperature dependence of fructose 6-phosphate/fructose 1,6-bisphosphate cycling may be regulated by fluctuation of fructose 2,6-bisphosphate concentration and changes in the affinity of both enzymes for substrates and effectors. Moreover, in the presence of in vivo concentrations of substrates, phosphofructokinase is inactive in the absence of fructose 2,6-bisphosphate.

Animals↗
PubMed1975

Abnormal heart rate responses during exercise in patients with Chagas' disease.

Normal subjects and cardiac chagasic patients without previous history of congestive failure or actual evidences of cardiac decompensation were exercised on a treadmill or a bicycle ergometer. Patients with less than the expected increase in heart rate during exercise were found to exhibit also an abnormal heart rate response to pharmacologic blockade and acute alterations in systemic vascular resistance. These results are in agreement with previous observations showing neuronal degeneration and autonomic impairment in chronic Chagas' heart disease.

Chagas Disease↗
PubMed1975

Postural reflexes in chronic Chagas's heart disease. Heart rate and arterial pressure responses.

Studies of heart rate and blood pressure responses to 70 degrees head-up tilt and 30 degrees head-down tilt were conducted in normal subjects and in chronic cardiac chagasic patients without past or present cardiac decompensation. During steady state of tilt, heart rate alterations were less marked in the chagasic than in the control group. Vasodepressor syncope supervened in three cardiac chagasic patients, two of whom showed the distinctive feature of hypotension without reflex bradycardia. In these patients, vagal control of cardiac rate could not be demonstrated either following a full blocking dose of atropine or during sudden elevation of systemic arterial blood pressure. These results are interpreted in the context of the pathologic and functional derangements of autonomic control which occur in Chagas' heart disease.

Adult↗
PubMedDate not supplied

Duhamel procedure for sigmoid cancer.

A description is given of the advantages of the Duhamel technique over that carried out by colorectal anastomosis at the level of the pelvis. The anastomosis is performed at the level of the perineum. Ten patients with cancer of the colon were operated and it was determined that there was no tumoral relapse of the residual ampulla. There were no complications and this technique can be used as a substitute for Hartmann's.

Evaluation Studies as Topic↗