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Biomedical subjects

A Torres

Publications and source records attributed to A Torres.

At least 595 records · Page 33Linked to original sources
PubMed1988

Response of heart rate to atropine and left ventricular function in Chagas' heart disease.

Chagasic patients may have a normal or abnormal response of heart rate to atropine. To determine if this response to atropine is related to the degree of left ventricular dysfunction, we studied 33 patients with a positive complement fixation test for Chagas' disease. Eleven subjects, with atypical chest pain and negative complement fixation test, were used as controls (sero-negative). Left ventricular wall motion and the left ventricular volumes were determined by ventricular cineangiography. Coronary arteriography was also performed. The sero-negative subjects had normal left ventricular wall motion and the left ventricular diastolic volume was 88 +/- 24 ml/m2. The response of heart rate to atropine was 50 +/- 8 (mean +/- SD) (range 40-65 beats/min). On the basis of the response to atropine, the chagasic patients were divided into groups with a normal response (greater than 40 beats/min) and those with an abnormal response (less than 40 beats/min). Sixty five per cent of those with a normal response had left ventricular apical aneurysms. The left ventricular end-diastolic volume was not significantly different from the sero-negative subjects (96 +/- 26 ml/m2). Six patients (30%) had a left ventricular diastolic volume between 110 and 140 ml/m2. Sixty two per cent of those chagasic subjects with an abnormal response had diffuse left ventricular hypokinesis, and the left ventricular end-diastolic volume was 192 +/- 49 ml/m2 (P less than 0.01). The response of heart rate and the left ventricular diastolic volume were inversely correlated in the chagasic patients (r = -0.88, P less than 0.01). Our results indicate that myocardial damage and the degree of left ventricular dilatation are more severe in chagasic patients with an abnormal response of their heart rate to atropine. Furthermore, the inverse correlation between these two variables is highly indicative of a relationship between the response of heart rate to atropine and the degree of left ventricular dysfunction.

Adult↗
PubMed1988

Comparative analysis of the VP3 gene of divergent strains of the rotaviruses simian SA11 and bovine Nebraska calf diarrhea virus.

The gene encoding outer capsid protein VP3 of subpopulations of two animal rotaviruses, simian SA11 and Nebraska calf diarrhea virus (NCDV), was analyzed. Two laboratory strains of simian SA11 rotavirus (SA11-SEM and SA11-FEM) differed with respect to VP3. This dimorphism was indicated by a difference in electrophoretic mobility and a difference in reactivity with anti-VP3 monoclonal antibodies. The overall VP3 amino acid homology between the two SA11 VP3 proteins was 82.7%, whereas the VP3 protein of SA11-FEM was 98.5% homologous in amino acid sequence to NCDV VP3, suggesting that SA11-FEM VP3 was derived by gene reassortment in the laboratory during contamination with a bovine rotavirus. A comparison of the deduced amino acid sequence of the VP3 of two virulent NCDV strains and an attenuated NCDV strain (RIT 4237), revealed only five amino acid differences which were scattered throughout the protein but did not involve the trypsin cleavage sites. Of interest, the VP3 of the standard strain of NCDV which is virulent for cows differed in only one amino acid (position 23, Gln to Lys) from the VP3 of an NCDV mutant which was attenuated both for cows and for children.

Amino Acid Sequence↗
PubMed1988

Morphological variations of human ossicula tympani.

In a series of 100 cases, morphological variations of human ossicula tympani were studied. These have seldom been considered either in classic or recent descriptions. Among them, the malleus and stapes are the most variable ones. A geometric model is proposed to systematically study any variation from the typical ossicles. These morphological variations of ossicles could be related to age, sex, race, and could bring out peculiarities in acoustic transmission.

Ear Ossicles↗
PubMed1988

Effect of almitrine on ventilation-perfusion distribution in adult respiratory distress syndrome.

Almitrine improves ventilation/perfusion relationships (VA/Q) in COPD, but its effects in ARDS, in which VA/Q mismatching is the cause of severe hypoxemia, are not known. The effects of almitrine on pulmonary gas exchange and circulation were assessed in 9 patients with ARDS who were sedated, paralyzed, and mechanically ventilated at constant FlO2 (range, 0.48 to 0.74). Systemic and pulmonary hemodynamics, conventional gas exchange, and the VA/Q distribution by the multiple inert gas elimination technique (MIGT) were measured before (baseline), during (ALM 15), at the end of (ALM 30), and at 30-min intervals after (POSTALM 30, 60, and 90) the intravenous infusion of 0.5 mg/kg body weight of almitrine over 30 min. Almitrine significantly increased PaO2 from 78 +/- 15 mm Hg to 140 +/- 49 at ALM 15 and 138 +/- 52 at ALM 30. AaPO2 and QS/QT decreased during the administration of the drug. The MIGT showed that almitrine redistributed pulmonary blood flow from shunt areas (reduction from 29 +/- 11 to 17 +/- 11% of QT) to lung units with normal VA/Q ratios (increase from 63 +/- 9 to 73 +/- 6% of QT). The Ppa increased from 26 +/- 5 to 30 +/- 5 mm Hg without changes in QT. Changes were transient, returning toward baseline 30 min after stopping the infusion of the drug. Almitrine significantly reduced the VA/Q inequalities present in ARDS and may be useful in the management of those patients.

Adult↗
PubMed1988

Diagnostic value of telescoping plugged catheters in mechanically ventilated patients with bacterial pneumonia using the Metras catheter.

A new guiding technique, Metras catheter (MC), for blindly introducing a telescoping plugged catheter (TPC) was applied to 25 mechanically ventilated patients with suspected bacterial pneumonia (BPN). Results obtained with TPC-MC were compared with those obtained with TPC using a conventional fiberoptic bronchoscope (FB) in random order. The diagnosis of BPN was definitely confirmed in 18 patients. In 7 patients, all TPC samples (MC and FB) were sterile, and a diagnosis other than BPN was proved. In the former group, colony-forming units equal to or greater than 10(3)/ml of one or more microorganisms were obtained in 61% of TPC-MC and in 66% of TPC-FB samples. These percentages increased to 64 and 71%, respectively, when 4 patients with previous antibiotic treatment were excluded from the study group. Agreement was observed between microorganisms cultured from both TPC samples in 11 of 18 patients with proved BPN (61%). Complete disparity was seen only in 2 patients (11%). Two patients developed a self-limiting hemoptysis after the TPC procedure (MC and FB, respectively). We conclude that TPC-MC is both a sensitive and specific technique for the diagnosis of BPN in mechanically ventilated patients. Because the diagnostic value of TPC-MC is similar to that of TPC-FB, we propose that the MC be used in patients receiving mechanical ventilation when the FB is not available. The simplicity and lower cost of this new system are important advantages to be considered over the fiberoptic bronchoscope.

Adult↗
PubMed1988

Nosocomial pneumonia. A multivariate analysis of risk and prognosis.

One hundred and twenty consecutive episodes of nosocomial pneumonia (NP) in 118 nonneutropenic adults admitted to a 1,000-bed teaching hospital were studied in order to investigate the prognosis and risk factors. The overall fatality rate was 36.6 percent. The identification of a "high-risk" microorganism (Pseudomonas aeruginosa, Enterobacteriaceae, and other Gram-negative bacilli, Streptococcus faecalis, Staphylococcus aureus, Candida sp, Aspergillus sp, and episodes of polymicrobial pneumonia), bilateral involvement on chest x-ray examination, the presence of respiratory failure, inappropriate antibiotic therapy, and age older than 60 years or an underlying condition ultimately or rapidly fatal were those factors selected by a stepforward logistic regression analysis as independently worsening the prognosis. A series of variables frequently quoted as predisposing to NP was determined to be either present or absent in the same 120 cases of NP and in an equal number of randomly selected control subjects. After adjusting for confounding, factors significantly predisposing to NP were tracheal intubation, depressed level of consciousness, underlying chronic lung disease, thoracic or upper abdominal surgery, prior episode of a large volume aspiration, and age older than 70 years. Since some of the factors influencing the risk or the prognosis of NP are amenable to medical intervention, a percentage of NP might be prevented and its prognosis can be improved.

Adult↗
PubMed1988

Lung function changes following Legionnaires' disease.

Eleven out of thirteen patients hospitalized because of severe pneumonia caused by Legionella Pneumophila were evaluated over a period of 53 months. During the acute phase, all but one patient manifested severe hypoxaemia, needing either supplementary oxygen or, in the case of three, mechanical ventilation and one died. Following recovery, two patients complained of mild shortness of breath alone. However, most of the individuals showed subclinical mild to moderate ventilatory and/or gas exchange abnormalities a few months after discharge (less than 6 months). Despite the fact that some of these functional findings in part persisted at long-term (6-33 months), a significant overall improvement in lung function was noticed. The main pulmonary functional sequelae following Legionnaires' Disease might include a restrictive ventilatory defect, a low transfer factor and hypoxaemia.

Acute Disease↗
PubMed1987

Hypertensinogenic factors and renal alpha-adrenoceptors in young SHR and WKY rats.

The effects of high sodium intake (drinking 1% NaCl), DOCA and DOCA + 1%NaCl for 6 weeks on renal alpha 1- and alpha 2-adrenoceptors and on systolic blood pressure (SBP) were examined in young spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). On normal sodium intake, SHR rats had higher renal alpha 1 (p less than .001) and alpha 2-adrenoceptor densities (p less than .001) and SBP (p less than .001) than WKY rats. Although, WKY rats given either 1% NaCl, DOCA, and DOCA + 1% NaCl developed hypertension after 6 weeks of treatment, only 1% NaCl administration for the same period produced an increase in the alpha 1- and alpha 2-adrenoceptor densities when compared to the control (p less than .01 and p less than .001, respectively). In the SHR rats, to the contrary, ingestion of 1% NaCl and DOCA + 1% NaCl increased the already elevated alpha 2-adrenoceptor density (p less than .001) and SBP even more in this strain after 6 weeks of treatment. Equilibrium dissociation constants (KD), however, were similar for both classes of receptors in experimental and control rats. This study indicates that postweaning exposure of the WKY and SHR rats to a high salt treatment and DOCA can influence the renal alpha-adrenoceptor densities. Although the functional significance of the changes is unclear, it is reasonable to speculate that postweaning exposure to a hypertensinogenic stimuli such as a 1% NaCl and/or DOCA may ultimately interfere with the functional development of the kidney differently in rats genetically predisposed to hypertension (SHR) from normotensive (WKY) rats.

Animals↗