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Biomedical subjects

A Torres

Publications and source records attributed to A Torres.

At least 613 records · Page 34Linked to original sources
PubMed1987

Decreased insulin binding and antilipolytic response in adipocytes from patients with Cushing's syndrome.

Human adipocytes from patients with chronic endogenous hypercortisolism (Cushing's syndrome) showed a statistically significant decrease in insulin binding at low unlabelled-insulin concentrations but no change in receptor numbers (Cushing's 180,000 +/- 48,000 (3) receptors/cell and controls 189,000 +/- 30,000 (7)) together with a fourfold decrease in apparent receptor affinity (ED50: Cushing's 2.25 x 10(-9) M and controls 0.57 x 10(-9) M) and a decreased sensitivity to the antilipolytic effect of insulin. These events could represent the final situation of a chronic and endogenous regulation by high levels of cortisol of insulin receptors in human adipose tissue.

Adipose Tissue↗
PubMed1987

Noninvasive determination of pulmonary arterial systolic pressure by continuous wave Doppler.

We evaluated the accuracy of continuous wave Doppler for estimating pulmonary arterial systolic pressure in patients with tricuspid regurgitation. Of 44 patients with a variety of cardiac disorders, 39 (89%) had Doppler-detected tricuspid regurgitation. Adequate spectral profiles of the flow signals were obtained in 34 of them (87%), representing 77% of the entire group. Continuous wave Doppler ultrasound was used to measure the maximum velocity of the regurgitant jet, and by applying the modified Bernoulli equation, the systolic pressure gradient between the right ventricle and the right atrium was calculated. Pulmonary arterial systolic pressure was estimated by adding the transtricuspid gradient to the mean right atrial pressure, and correlated well with catheterization values (r = 0.96). The correlation coefficient was not significantly modified if mean right atrial pressures were excluded in the calculations (r = 0.91). Continuous wave Doppler constitutes a sensitive method for the detection of tricuspid regurgitation. The method using the tricuspid gradient provides an accurate estimation of pulmonary arterial systolic pressure. Combined with other available methods (pulsed wave Doppler), this noninvasive technique can yield information comparable with that obtained at catheterization.

Adolescent↗
PubMed1987

Susceptibility of urinary isolates of Corynebacterium group D2 to fifteen antimicrobials and acetohydroxamic acid.

The susceptibility in vitro of 28 Corynebacterium group D2 strains, mainly isolated from urine, to fifteen antimicrobial agents and acetohydroxamic acid (AHA) was determined at two pH values. The bactericidal activity of four antimicrobials and AHA was studied in three reference strains in broth at two pHs and with two inoculum sizes. The activity of norfloxacin and AHA, against one selected strain, in broth and human urine, was also determined. Vancomycin, ofloxacin and norfloxacin were the most active agents tested. Norfloxacin acted bactericidally in broth and in human urine but was not synergic with AHA.

Anti-Bacterial Agents↗
PubMed1987

Neuronal antinuclear antibody (anti-Hu) in paraneoplastic encephalomyelitis simulating acute polyneuritis.

A patient with paraneoplastic encephalomyelitis (PEM) and small cell lung cancer had a clinical presentation of acute polyneuritis. The patient had an antibody (anti-Hu) restricted to nuclei of neurons identical to that reported in patients with subacute sensory neuronopathy and lung cancer. This finding further supports the hypothesis that PEM and subacute sensory neuronopathy are closely related disorders of autoimmune origin. PEM should be considered in patients with small cell lung cancer and clinical features limited to the peripheral nervous system.

Antibodies, Antinuclear↗
PubMed1987

[Chronic effect of prazosin and yohimbine on the renal epinephrine content of DOCA-sodium and SHR-hypertensive rats].

The chronic effect of two alpha-adrenergic receptor blockers, prazosin and yohimbine, on the renal noradrenaline (NA) content was investigated in two models of hypertensive rats, the DOCA-salt and the spontaneously hypertensive rats (SHR). In DOCA-salt rats an inversal relation exists between the level of blood pressure and renal NA content in all groups studied, except those treated with yohimbine and prazosin plus yohimbine. In SHR rats a decreased renal NA content has been detected with respect to their normotensive Wistar-Kyoto (WKY) rat controls. The administration of prazosin and/or yohimbine did not alter the renal NA content of the SHR rats, while on the contrary these agents produced an elevation of these levels in kidneys from normotensive WKY rats. These results suggest that the alpha-selective blocker agents used, demonstrate a different effect on the renal NA content in the two models of hypertension studied.

Adrenergic alpha-Antagonists↗
PubMed1986

Behaviour of the contact phase of blood coagulation in the adult respiratory distress syndrome (ARDS).

In order to assess the role of the kallikrein-kinin (K-K) system in the pathogenesis of the adult respiratory distress syndrome (ARDS) we have prospectively determined coagulation contact phase, blood gas and hemodynamic parameters in patients with ARDS at 0, 36 and 72 h from diagnosis. Compared to normal values, significantly lower mean levels of factor XII (71.4 +/- 9.8%, p less than 0.0005), prekallikrein (PPK) (52 +/- 5.7%, p less than 0.0005), high molecular weight kininogen (HMWK) (73 +/- 2%, p less than 0.0005) and alpha 2-macroglobulin (alpha 2-M) (51 +/- 7.1%, p less than 0.0005) were found in ARDS patients. The functional kallikrein inhibitory activity (KKI) and C1-esterase inhibitor antigenic (CIINH) were significantly higher in these patients (113.2 +/- 5, p less than 0.005 and 124.7 +/- 7.6, p less than 0.0005 respectively) compared with normal values during the entire study period. The KKI/CIINH ratio decreased significantly in our ARDS patients at 0, 36 and 72 h (p less than 0.025; p less than 0.05 and p less than 0.005 respectively). We found a significant correlation between PPK levels and oxygenation index (r = 0.69, p less than 0.001), PPK and the static thoracic compliance values (r = 0.64, p less than 0.001). There was also a significant correlation between PPK levels and Qs/Qt (r = -0.89, p less than 0.001). ARDS patients that survived presented a stability in the PPK values in successive tests. Nevertheless non-survivors showed a progressive decrease in PPK levels during the follow-up period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Comparison of Doppler-determined elevated pulmonary arterial pressure with pressure measured at cardiac catheterization.

This study assesses use of pulsed Doppler echocardiography to measure pulmonary artery (PA) pressure. PA flow at the right ventricular (RV) outflow tract was analyzed in 51 patients. Attention was focused on PA flow morphologic pattern, RV systolic intervals, time to peak flow and acceleration time index. Correlation was made with PA pressure and total pulmonary resistance. Three morphologic patterns of PA flow were found: type I indicates normal PA pressure (sensitivity 85%, specificity 100%) and types II and III indicate PA hypertension (sensitivity 100%, specificity 85%). The RV preejection/RV ejection ratio, time to peak flow and acceleration time index show a good correlation coefficient improved when a logarithmic function was applied. The best correlation was achieved with time to peak flow (r = -0.77 with PA pressure, r = -0.79 with total pulmonary resistance), and especially with acceleration time index (r = -0.84 with PA pressure, r = -0.87 with total pulmonary resistance). Analysis of pulmonary flow is a reliable new tool for evaluating PA pressure and is even better for evaluating total pulmonary resistance. Acceleration time index is the parameter that correlates best with these 2 variables.

Adolescent↗
PubMed1986

Altered renal alpha-adrenoceptor regulation in DOCA-salt rats: chronic effects of alpha 1- and alpha 2-receptor blockers.

Effects on the alpha-adrenoceptor binding in the kidneys of DOCA-salt rats were examined after a 6 week treatment of once-daily injections of prazosin, a selective alpha 1-adrenoceptor blocker; yohimbine, a selective antagonist for alpha 2-adrenoceptors; and prazosin plus yohimbine. alpha 1-Receptor binding was decreased by prazosin, while alpha 2-receptor binding was increased by simultaneous administration of prazosin + yohimbine. Equilibrium dissociation constants (KD) for [3H]prazosin and [3H]yohimbine were not significantly different (between groups). Since these drugs can prevent the development of hypertension in DOCA-salt rats, the present data strongly suggests that selective alteration of alpha-receptor-mediated physiological responses is unrelated to decreased or increased binding site densities. The mechanism of hypertension prevention may involve changes in the coupling of receptors to postreceptor events.

Adrenergic alpha-Antagonists↗
PubMed1986

Comparative activity of ofloxacin and seven other antimicrobials against urea-splitting microorganisms.

Urinary tract infections caused by urea-splitting bacteria are severe clinical conditions and very difficult to treat due to their association with calculi, and because such bacteria form ammonium hydroxide raising the urinary pH and thereby creating an unfavourable condition for the action of most antimicrobials. We tested ofloxacin, norfloxacin, nalidixic acid, amoxicillin, amoxicillin-clavulanic acid, gentamicin, co-trimoxazole and nitrofurantoin against 143 gram-negative and 99 gram-positive bacteria, all urea-splitting, isolated from patients with urinary tract infections. All drugs were tested using media at two different pHs (pH 7.4 and PH 8.5) and two inoculum sizes (10(4) and 10(6) cfu). Although ofloxacin and norfloxacin had a similar spectrum of activity, ofloxacin had somewhat greater intrinsic activity against gram-positive organisms. MICs of ofloxacin for 90% of Proteus mirabilis, indole-positive Proteus spp., Klebsiella pneumoniae, Staphylococcus aureus, coagulase-negative staphylococci and the Corynebacterium group D2 were greater than or equal to 4 mg/l. The activity of the other drugs varied, but there were many strains resistant to these antimicrobials. The pH and inoculum size did not significantly affect the activity of ofloxacin so that this drug should be useful for the treatment of urinary tract infections caused by the commonest urea-splitting bacteria involved in such infections.

Anti-Bacterial Agents↗
PubMed1986

Benign histiocytoma (xanthoma) of the rib.

A 64-year-old man was found to have isolated focal rib lesion(s) by radiographs and radionuclide bone scan. A biopsy of one of the lesions located by imaging was done. The histologic diagnosis was sclerosing (ossifying) xanthoma. A literature search disclosed that xanthomatous lesions of bone are only one of the manifestations in hyperlipidemic patients. These benign lesions should be included among the causes of discrete hot rib abnormalities visualized on bone scan.

Biopsy↗
PubMed1986

The effects of delayed function on recipients of cadaver renal allografts. A study of 158 patients randomized to cyclosporine or ALG-azathioprine.

We randomized 158 recipients of cadaver renal allografts to cyclosporine-prednisone (83) or antilymphocyte globulin-azathioprine-prednisone (75) to evaluate: the effects of immunosuppression and pretransplant risk factors on the incidence of delayed graft function, the effects of immunosuppression on the resolution of delayed graft function, and the effects of delayed graft function and pretransplanted risk factors on patient and graft survival. Cyclosporine did not increase the incidence of delayed graft function, compared with ALG-azathioprine-treated patients (33% versus 27%, P = 0.550) but doubled the mean (+/- SD) duration of oliguria (11.8 +/- 11.0 versus 5.9 +/- 3.2 days, P = 0.002) and the number of required dialyses (6.6 +/- 7.6 versus 3.2 +/- 1.3, P = 0.031). Retransplanted patients had a higher incidence of delayed graft function that recipients of primary grafts in both the cyclosporine (82% versus 25%, P = 0.001) and ALG-azathioprine (55% versus 22%, P = 0.025) treatment groups. The presence of delayed function reduced one-year graft survival from 89% in all patients without delayed function to 72% (P = 0.011) in all patients with delayed function. Cyclosporine-treated patients had a slightly, but not significantly better one-year graft survival rate than ALG-azathioprine treated patients both with (73% versus 68%, P = 0.750) and without (92% versus 82%, P = 0.069) delayed graft function. A preservation time longer than 24 hr did not increase the incidence of delayed graft function in cyclosporine-treated patients (34% versus 32%, P = 0.811) or ALG-azathioprine-treated patients (27% versus 27%, P = 0.902). Cyclosporine-treated patients given kidneys with greater than 24 hr of preservation time had reduced graft survival only when delayed graft function occurred (67% versus 92%, P = 0.009). In conclusion, (1) cyclosporine did not increase the incidence of delayed graft function over ALG-azathioprine treatment; (2) cyclosporine did significantly slow recovery of kidneys with delayed function; (3) delayed graft function correlated with poorer graft survival rate in both treatment groups; but (4) prolonged preservation time did not increase the incidence of delayed graft function or reduce graft survival.

Actuarial Analysis↗
PubMed1986

Diarrheal response of gnotobiotic pigs after fetal infection and neonatal challenge with homologous and heterologous human rotavirus strains.

Pigs exposed in utero to human rotavirus (HRV) strain Wa serotype 1 from 15 to 36 days prior to birth responded immunologically by modifying their clinical response to neonatal oral challenge with a pathogenic dose of homologous Wa or heterologous M serotype 3 HRV. In these cases, diarrhea was prevented in 12 of 14 pigs and greatly reduced in the other two. However, fecal virus shedding was not significantly modified, since it was detected in 12 of 14 pigs. These results suggest the existence of a closer antigenic relationship between these two different HRV serotypes which may only be expressed in an in vivo test system. Exposure of fetal pigs to HRV DS-1 serotype 2 failed to cause infection or to induce any protection when pigs were challenged at birth with HRV Wa. This model for cross-protection studies in gnotobiotic piglets offers good possibilities for the evaluation of potential HRV vaccine candidates, for the in vivo study of antigenic similarities between rotavirus serotypes, and for the understanding of protective immune responses against diarrhea and virus shedding.

Animals↗