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Biomedical subjects

S Lima

Publications and source records attributed to S Lima.

15 recordsLinked to original sources
PubMed2006

How does beta-cyclodextrin affect oxygen solubility in aqueous solutions of sodium perfluoroheptanoate?

The solubility of oxygen in aqueous solutions of sodium perfluoroheptanoate (NaPFHept) at different concentrations was measured at 310.15 K with an apparatus based on the saturation method. The effect of adding beta-cyclodextrin (betaCD) on the solubility of oxygen was also studied. Conductimetry measurements showed that the presence of betaCD in aqueous solutions of NaPFHept increases its critical micellar concentration (CMC). In the presence of betaCD (15 mM), the characteristic minimum of oxygen solubility observed at the CMC is shifted from 83 to 114 mM, and the curvature at the minimum is reduced to 64% of the value in the absence of betaCD. Chemical shift changes for the H5 protons of betaCD, recorded as functions of the initial concentration of NaPFHept, point to the formation of a relatively strong 1:1 inclusion in betaCD of the perfluoroheptanoate anion. Hence, it is suggest that the effect of adding betaCD on the solubility of oxygen cannot be accounted for only by the perfluoroheptanoate anion inclusion in betaCD, but has to be ascribed to the direct influence of this inclusion complex on disrupting the aggregation process reducing the increase of oxygen solubility after the CMC value.

Journal Article↗
PubMed2005

Exercise effects on cardiac size and left ventricular diastolic function: relationships to changes in fitness, fatness, blood pressure and insulin resistance.

OBJECTIVES: To determine exercise training effects on cardiac size and left ventricular (LV) diastolic function and relationships of exercise induced changes in physiological and body composition parameters with cardiac parameters. DESIGN: Prospective, randomised controlled trial. SUBJECTS: Men and women (63.6 (5.7) years, body mass index 29.5 (4.4) kg/m(2)) with untreated hypertension (systolic blood pressure (BP) 130-159 or diastolic BP 85-99 mm Hg). MAIN OUTCOME MEASURES: Cardiac size and LV diastolic function, peak oxygen uptake (Vo(2)), muscle strength, general and abdominal fatness, and insulin resistance. INTERVENTIONS: 6 months of exercise training versus usual care. RESULTS: When analysed by group at six months, cardiac size and LV diastolic function did not differ between exercisers (n = 51) and controls (n = 53), whereas exercisers had significantly higher peak Vo(2) (28 v 24 ml/kg/min) and strength (383 v 329 kg), and lower fatness (34% v 37%), diastolic BP (73 v 75 mm Hg) and insulin resistance (quantitative insulin sensitivity check index 0.35 v 0.34) versus controls (all p <or= 0.05). By regression analysis, among six month changes, increased peak Vo(2) and reduced abdominal fat were associated with increased cardiac size. Increased peak Vo(2) and reduced abdominal fat, BP and insulin resistance were associated with improved LV diastolic function. r Values ranged from 0.20 to 0.32 (p <or= 0.05). CONCLUSIONS: When examined by group assignment, exercise had no effect on cardiac size or LV diastolic function. When individual variations in six month changes were examined, participants attaining the greatest increases in fitness and reductions in abdominal fatness, insulin resistance and BP showed a modest trend towards physiological hypertrophy characterised by increased cardiac size and improved LV diastolic function. These results suggest that decreased abdominal fatness may have a role in improving cardiovascular health.

Aged↗
PubMed1989

Percutaneous transhepatic biliary drainage: alternatives in left hepatic duct obstruction.

The left-lobe subxiphoid approach has been the standard way to drain left hepatic duct occlusion. A new, right-side biliary drainage approach is described. Five patients, among 25 patients with bilateral biliary obstruction, were treated by an internal-internal drainage system. Three types of internal-internal drainage techniques are described: internal-internal luminal, type 1; internal-internal luminal, type 2; and internal-internal transductal, type 3. All 5 patients succeeded in biliary drainage. The internal-internal biliary drainage technique, performed from the right-side approach, is effective, avoids additional liver puncture and tract dilatation, and allows the combination of several biliary drainage techniques, adding greatly to the flexibility when treating intrahepatic obstruction. No complications were observed in our small series but special precaution should be taken with the transductal technique due to the possibility of bleeding.

Aged↗
PubMed1988

Transient atrial dysfunction after conversion of chronic atrial fibrillation to sinus rhythm.

Although conversion of atrial fibrillation (AF) to sinus rhythm can usually be accomplished by electrical or drug therapy, effective atrial systole may not be restored. To investigate the return of atrial transport function and its relation to the duration of the arrhythmia, Doppler echocardiography was performed after conversion in 18 patients with acute AF (less than or equal to 1 week duration), 14 patients with chronic AF (greater than 1 week duration) and 15 control patients. Flow velocities during rapid filling (E wave) and atrial systole (A wave) were measured in both left and right ventricles. Patients in the acute AF group had left ventricular A waves (49 +/- 4 cm/s) and A/E ratios (0.97 +/- 0.1) similar to those of the control patients (55 +/- 7 cm/s, 0.87 +/- 0.08, respectively). In contrast, patients in the chronic AF group had much smaller A waves (19 +/- 5 cm/s) and A/E ratios (0.30 +/- 0.08) than those in the other 2 groups (p less than 0.001). Five patients with chronic AF (36%) had complete left atrial paralysis (A/E = 0) despite normal sinus P waves. Measurements in the right ventricle showed similar differences among the groups. Patients with chronic AF who maintained sinus rhythm showed an increase in A/E ratio to control levels, from 0.45 +/- 0.1 to 0.93 +/- 0.1 (p = 0.003) at 48 days (average) after conversion. Thus, atrial transport function is normal after brief periods of AF, but reduced or absent when conversion is achieved after the arrhythmia has been sustained greater than 1 week.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1986

Carotid-cavernous fistulas: embolization through the superior ophthalmic vein approach.

Five patients aged 17-33 years with traumatic carotid-cavernous fistulas (CCFs) were treated by antegrade embolization through a superior ophthalmic vein approach, using cutdown technique on the upper eyelid. CCFs had recurred after prior treatment by multivessel ligation in three patients. Embolization through the ophthalmic vein resulted in long-term cure in three patients. The remaining patients were successfully treated by embolization through the arterial approach after failure of the ophthalmic vein technique. This is a new and rewarding technique to treat patients with CCFs, especially when there has been carotid ligation, provided the ophthalmic vein is thickened and arterialized.

Adolescent↗
PubMed1986

Intravascular foreign bodies: percutaneous retrieval.

Percutaneous retrieval of an intravascular foreign body was performed in 20 patients. There were 14 through-the-needle intravenous catheter fragments. In four patients the embolized foreign body was a broken diagnostic catheter. One patient had a ventriculovenous broken catheter and another patient had a bullet in the pulmonary circulation. Eight foreign bodies were located in the superior vena cava, six in the pulmonary artery, two in the right side of the heart, one in the subclavian vein, one in the thoracic aorta, and two in the aortoiliac segment. Percutaneous retrieval was successful in 95% of the attempts. In one case the procedure was performed to dislodge the foreign body into a better position for surgical retrieval.

Adolescent↗
PubMed1985

Impaired thickening of nonischemic myocardium during acute regional ischemia in the dog.

To study the regional function of nonischemic myocardium after the onset of regional ischemia, graded circumflex coronary arterial stenosis was induced in 18 open-chest anesthetized dogs. Two-dimensional echocardiographic views were obtained at each degree of occlusion in a cross-sectional plane marked by two to three metal beads sewn to the left ventricular epicardium. Percent systolic thickening was measured at 16 equally spaced points around the left ventricle and correlated with microsphere-determined regional myocardial blood flow. Baseline thickening averaged 44.9 +/- 6.4%. During transmural ischemia percent systolic thickening decreased to -16.1 +/- 4.0% in the ischemic region and also decreased in adjacent nonischemic regions (to 2.4 +/- 2.4% in segments closest to the ischemic region [adjacent 1] and to 15.5 +/- 3.9 in segments further away [adjacent 2]), but was unchanged in segments directly opposite the ischemic region (remote region). During subendocardial ischemia, percent systolic thickening fell only in the ischemic and adjacent 1 regions (1.4 +/- 5.2% and 24.9 +/- 5.0%, respectively). Dipyridamole, 0.21 to 0.42 mg/min iv, given to seven dogs during transmural ischemia, caused a three- to fivefold increase in flow to the nonischemic and no change in flow to the ischemic region; function was not altered in any region. Propranolol, 0.1 mg/kg iv, was given to five dogs during transmural ischemia to depress contractility in the remote region. Percent systolic thickening fell in the remote (from 50.0 +/- 7.7% to 34.6 +/- 5.6%), but increased in adjacent 1 (from -0.25 +/- 3.7% to 15.2 +/- 3.9%) and in adjacent 2 (from 17.4 +/- 2.8% to 33.4 +/- 3.9%) regions, and remained unchanged in the ischemic region. We conclude the following: During transmural ischemia percent systolic thickening is markedly impaired in nonischemic myocardium immediately adjacent to the ischemic region, and is impaired to a lesser degree in regions located relatively far from the ischemic border. Dysfunction therefore overestimates the extent of regional ischemia after total coronary occlusion. During subendocardial ischemia function ceases in the ischemic region and functional impairment of nonischemic myocardium is restricted to immediately adjacent regions. Dysfunction of adjacent regions is not caused by "relative ischemia" related to increased local oxygen demands or to a steal phenomenon. Mechanical tethering of nonischemic myocardium adjacent to ischemic regions, secondary to changes in left ventricular shape during contraction, may contribute to the impairment of systolic thickening in adjacent regions during transmural ischemia.

Acute Disease↗
PubMed1984

Management of traumatic hematuria by selective renal artery embolization.

Angiography and selective renal arterial embolization were performed in 17 patients with traumatic lesions of the kidney and hematuria. Of the patients 8 had retroperitoneal extravasation of contrast medium owing to rupture, 6 had traumatic arteriovenous fistulas and 5 had pseudoaneurysms. Immediate control of hemorrhage was achieved in 16 patients (94.1 per cent), while delayed control was obtained in 1. Hematuria recurred in 4 of the 17 patients (23.5 per cent) and resulted in total nephrectomy in 3 (17.6 per cent) despite repeated embolization in 2. Embolization alone was successful in 14 patients (82.4 per cent). According to the followup preservation of renal function and viable parenchyma was excellent in all embolized patients. Our results indicate that transcatheter embolization should be performed in patients with renal trauma and uncontrollable hematuria before any surgical attempt is made.

Adolescent↗
PubMed1981

Angiography in primary myomas of the alimentary tract.

Fifteen cases of smooth muscle tumor of the alimentary tract were collected for analysis from several institutions. The findings showed that angiography is the best method available for diagnosis and evaluation of such tumors but is unable to differentiate benign from malignant lesions unless arterial invasion is detected. Computer tomography, ultrasound, and angiography are compared in the diagnosis of one case. Additionally, the angiographic pattern of a leiomyoblastoma is presented, presumably for the first time.

Adult↗
PubMed1980

Percutaneous transhepatic portography for obliteration of gastroesophageal varices in partial and total portal vein occlusion.

The obliteration of gastroesophageal varices was attempted with percutaneous transhepatic portography in seven patients who had partial and total portal vein occlusion. The procedure was successful and stopped variceal bleeding in three patients. In three cases only portography was performed, and in another patient the examination was not possible. The possibilities of this new treatment for bleeding in portal vein thrombosis are discussed and the problems encountered in performing the examination are presented.

Adolescent↗
PubMedDate not supplied

Hemobilia: transcatheter occlusive therapy and long-term follow-up.

Eight patients with life-threatening hemobilia were treated by percutaneous transcatheter occlusive therapy. The bleeding was caused by a traumatic pseudoaneurysm of the hepatic artery in 6 cases (auto accident in 4, surgery in 1, biliary drainage in 1) and a true aneurysm of the hepatic artery in 2 (unknown etiology in 1 and mycotic in 1). Arterial catheterization was used in all cases except for one in which a direct percutaneous puncture was performed. Gelfoam alone was used as embolic material in 3 patients. In 1 patient each, the material used was gelfoam plus coils, coils alone, blood clot, n-butyl-cyanoacrylate and an occluding balloon catheter. In all cases the bleeding stopped and did not recur during the follow-up period which ranged from 9 months to 14 years. This experience indicates that transcatheter occlusive therapy is an effective method for the treatment of severe hemobilia.

Adolescent↗