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Biomedical subjects

A Torres

Publications and source records attributed to A Torres.

At least 577 records · Page 32Linked to original sources
PubMed1989

Mechanisms of hypoxemia in patients with status asthmaticus requiring mechanical ventilation.

Eight consecutive patients (mean +/- SD age, 43 +/- 11 yr) with acute severe asthma (status asthmaticus) requiring assisted ventilation were studied within the first 24 to 48 h of admission, at maintenance FIO2 and while breathing 100% O2, using the multiple inert gas elimination technique. Ventilation-perfusion (VA/Q) inequality was characterized by a marked bimodal blood flow distribution (perfusion to normal and low VA/Q populations) in all but two patients, with a mean of 27.6 +/- 12.3% of the total perfusion present in the low VA/Q ratio units (between 0.1 and 0.005). As a result, the dispersion of pulmonary blood flow distribution (log SDQ) was severely abnormal (mean, 1.65 +/- 0.28; normal range, 0.3 to 0.6). No patient had a substantial shunt (VA/Q = 0) (mean value, 1.5 +/- 2.3%). The ventilation distribution was never bimodal, but the dispersion of the ventilation distribution (log SDV) was moderately elevated (1.01 +/- 0.24). High VA/Q areas (ventilation to VA/Q units between 10 and 100) were generally absent. While breathing 100% O2, PaO2, PvO2, and PaCO2 significantly rose, as did shunt and blood flow dispersion. Patients with life-threatening acute severe asthma treated by mechanical ventilation show: (1) the most abnormal gas exchange characteristics of the VA/Q spectrum observed to date in human asthma but essentially the same pattern as in patients with less severe disease; (2) a high level of hypoxic pulmonary vascular response; (3) a significant amount of shunt while breathing 100% O2, suggesting the presence of absorption atelectasis or redistribution of blood flow.

Adult↗
PubMed1989

Diagnostic value of quantitative cultures of bronchoalveolar lavage and telescoping plugged catheters in mechanically ventilated patients with bacterial pneumonia.

We compared the diagnostic value of quantitative cultures of bronchoalveolar lavage (BAL) and telescoping plugged catheter (TPC) samples in 34 nonimmunocompromised, mechanically ventilated (MV) patients with suspected bacterial pneumonia. A control group of seven "noninfected" MV patients was also studied. In 92% of patients with bacterial pneumonia (32 of 34), simple endotracheal aspiration samples recovered one or more microorganisms. Both BAL and TPC samples cultured colony-forming units (cfu) greater than or equal to 10(3)/ml of one or more microorganisms in 56% (19 of 34) of patients. TPC and BAL culture results agreed on 88.5% (54 of 61) of the recovered microorganisms. Sterile TPC and BAL cultures agreed on 80% (4 of 5) of the cases. Microorganisms cultured from blood samples were also cultured from BAL and TPC specimens. Culture results from the two techniques completely disagreed in only one case (3%). In the control group, one TPC and two BAL cultures yielded microorganisms in cfu greater than or equal to 10(3)/ml. Specificities of BAL and TPC were 71 and 86%, respectively, whereas specificity of endotracheal aspiration was only 14%. Both the bacterial index obtained by TPC and BAL, as well as the quantitative cultures, correlated moderately well (r = 0.78 and 0.72, respectively, p less than 0.001 for both correlations). BAL and TPC results caused changes of antibiotic treatment in 11 of 23 survivors. Neither BAL nor TPC caused complications. Our results demonstrate that BAL and TPC diagnose bacterial pneumonia in MV patients with similar accuracy. Culture results from both techniques showed excellent qualitative and reasonable quantitative agreement.

Adult↗
PubMed1989

Ventilation-perfusion mismatching in chronic obstructive pulmonary disease during ventilator weaning.

Using the multiple inert gas elimination technique, we studied ventilation-perfusion (VA/Q) relationships in eight patients with chronic obstructive pulmonary disease (COPD) during mechanical ventilation (MV) and again during weaning (spontaneous ventilation [SV] through an endotracheal tube) from MV needed for acute respiratory failure. The patients, seven men and one woman with a mean age of 63 +/- 2.8 (SEM) yr (FEV1 33 +/- 5.2% of predicted), required MV for 9.0 +/- 2.4 days prior to the study. The patients were studied at maintenance FIO2 (0.28 to 0.40) while breathing 100% O2, both during MV and SV. After 30 min of SV, PaCO2 increased from 48.9 +/- 3.4 to 58.3 +/- 3.1 mm Hg (p = 0.003) and pH decreased from 7.42 +/- 0.01 to 7.36 +/- 0.01 (p = 0.001) without significant changes in PaO2. Despite a decrease in tidal volume (VT) from 700.0 +/- 41.1 during MV to 313.0 +/- 39.6 ml during SV (p = 0.001), minute ventilation remained unchanged (from 8.2 +/- 0.7 during MV to 7.4 +/- 0.6 L/min during SV). Furthermore, cardiac output (QT), oxygen delivery (QO2), and mixed venous PO2 (PVO2) significantly rose during SV when compared with the MV (QT: from 4.7 +/- 0.4 to 6.7 +/- 0.7 L/min, p = 0.011; QO2: from 857.3 +/- 113.0 to 1078.5 +/- 158.9 ml/min, p = 0.0074; PVO2: from 36.7 +/- 1.1 to 42.3 +/- 2.2 mm Hg, p = 0.041). Overall VA/Q inequality worsened as blood flow was redistributed to low VA/Q areas (from 9.4 +/- 4.4 to 19.6 +/- 5.3% of QT, p = 0.05). The dispersion of the ventilation distribution (log SDV) significantly worsened during SV (from 1.0 +/- 0.08 during MV to 1.2 +/- 0.08 during SV, p = 0.044). No changes were observed in either series dead space or ventilation of high VA/Q ratio units.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

Pulmonary infiltrates in immunocompromised patients. Diagnostic value of telescoping plugged catheter and bronchoalveolar lavage.

The usefulness of telescoping plugged catheter (TPC) together with bronchoalveolar lavage (BAL) in the same bronchoscopic act in the diagnosis of pulmonary infiltrates was studied in 113 fiberoptic bronchoscopic examinations performed on 96 immunocompromised patients. The TPC cultures detected pulmonary bacterial infections in 25 (22 percent) cases but showed a high frequency of false positive results (12 microorganisms, 27 percent). Bronchoalveolar lavage had an overall diagnostic yield of 49 percent (53 of 113 cases). Combining TPC and BAL diagnostic values, 78 of 113 pulmonary infiltrates (69 percent) were diagnosed. The results obtained by both techniques allowed us to modify the treatment in 35 (31 percent) cases. Combined, TPC and BAL show a good diagnostic yield in immunocompromised patients with pulmonary infiltrates. Both techniques should be performed as the first approach in the evaluation of these patients, and be done in the same bronchoscopic procedure.

Bacteria↗
PubMed1989

The shift from home to institutional childbirth: a comparative study of the United Kingdom and The Netherlands.

The British system of childbirth with a very low rate of home childbirth is compared to that in The Netherlands, a country with a relatively high percentage of home deliveries. The analysis explores three possible explanations: the structure of the health professions in both countries, the structure of their health systems, and the use of scientific information in guiding policy decisions on birth place. Differences in the professional status and training programs of midwives between The Netherlands and the United Kingdom affected the distribution of home versus institutional deliveries in the two countries. Reimbursement schemes in The Netherlands have been important in maintaining a high percentage of births at home in this country. In the United Kingdom centralized planning and the influence of medical thinking played major roles in accelerating the shift from home to hospital deliveries in the National Health Service.

Birth Rate↗
PubMed1989

Renal alpha-adrenoceptor density and blood pressure in SHR rats exposed chronically to prazosin and/or yohimbine.

In the present study we evaluated the effect of selective alpha 1 and alpha 2-adrenoceptors blockade on the development of hypertension and on renal alpha-adrenoceptor densities in the spontaneously hypertensive rats (SHR). In these rats, daily intraperitoneal administration of 0.1 mg/kg of prazosin, yohimbine or prazosin + yohimbine for seven weeks significantly retarded the development of hypertension. In an attempt to characterize the relationship between changes in blood pressure and the renal alpha-adrenoceptor number after a prolonged alpha-blockade in the SHR, we have used 3H-prazosin and 3H-yohimbine as the selective ligands for alpha 1 and alpha 2-adrenoceptors. Saturation studies showed that renal alpha 1 and alpha 2-receptor densities were significantly decreased by prazosin and yohimbine, respectively, in SHR. Equilibrium dissociation constants (KD), however, were similar for both classes of receptors in experimental and control rats. In WKY rats, to the contrary, only prolonged administration of yohimbine and prazosin + yohimbine for seven weeks decreased the number of 3H-binding sites, and this decrease consisted in a Bmax change rather than an affinity (KD) change. Thus, the study provides evidence that the elevated blood pressure in the SHR is related, at least in part, to an abnormality in the adrenergic system control.

Animals↗
PubMed1989

[Antibody-coated bacteria in the sputum from patients with pneumococcal pneumonia].

In the present study an immunofluorescence technique detecting antibody-coated bacteria was evaluated. It was applied to the sputum of seven patients with bacteremic pneumococcal pneumonia to assess its diagnostic usefulness. We conclude that it is a valid, quick and easy technique which permits to differentiate between bacteria contaminating the sputum from those involved in the infection. This gives, therefore, a new value to the study of sputum. In our series the duration of the disease had no influence on the results, and the three antigammaglobulins used (anti-IgG, anti-IgA and anti-IgM) yielded the same results in each sample. Thus, we feel that the local pulmonary immune response was secondary in type.

Adult↗
PubMed1989

[Bone marrow necrosis as a manifestation of leukemic relapse in a patient with bone marrow transplant].

A case of bone marrow necrosis (BMN) in transplanted acute lymphoblastic leukaemia (ALL) is presented. The propositus is a 16 year-old boy with L-2 type ALL on whom allogeneic bone marrow transplantation (BMT) had been performed after the second relapse. He was admitted to hospital at 415 after BMT with fever, malaise and hip pain. One week later he had aplasia without blast cells. Scanty cellularity with necrobiosis was found in bone marrow aspirates; bone marrow biopsy confirmed the suspicion of BMN. Osseus scintigraphy with 99-Tc-diphosphonate showed poor, irregular distribution. Steroid therapy was followed by a favourable response. Peripheral blast cells appeared two weeks later, and the relapse was confirmed by bone marrow aspiration. Chemotherapy was started, but the patient died on day 467 after BMT. BMN has been reported in ALL at onset, in relapses, after chemotherapy and as necropsy finding; however, it had not been found in patients subjected to BMT. The experience of these Service was revised, this being the only case of 140 patients subjected to BMT who presented such severe complication.

Adolescent↗
PubMed1989

Tumoral calcinosis in two infants.

Tumoral calcinosis (TC) is an uncommon disease, characterized by deposits of large, calcified painless soft-tissue masses around major joints in otherwise healthy children and young adults. This condition is a rare inherited metabolic disorder of unknown etiology. Biochemical findings are normal except for its occasional association with hyperphosphatemia. The youngest occurrence reported in the literature on TC may be one case of a five-month-old boy. The authors report here on two younger infants with TC, one aged ten days and the other aged three months, who were followed for more than three years and observed to completely recover all motorskeletal functions.

Blood Chemical Analysis↗
PubMed1989

[Clinical study of tuberculosis in immunocompromised patients].

We have reviewed the clinical histories of 1,815 immunocompromised patients seen in "La Paz Hospital" over a period of 6 years, in order to study the incidence and clinical forms of tuberculosis (TB) in this group of patients. We have distributed the patients into three groups: Group A: 1,372 patients with neoplasia, Group B: 173 patients under immunosuppressor treatment, and Group C: 270 intravenous drug abusers (IVDA). 53 patients developed TB (2.9%): Of these, 31 belonged to group A (2.25%), 14 to group B (5.78%) and 8 to group C (2.96%), resulting in an incidence 50 to 100 times greater than the calculated for the Spanish general population (0.05%). There is a greater incidence of extrapulmonary and atypical forms in IVDA and patients under immunosuppressor treatment. Patients with neoplasia do not present differences in these aspects with regard to immunocompetent patients. If the TB is diagnosed and treated on time it is a potentially curable disease and the immunosuppressed state does not condition a worse response to treatment.

HIV↗
PubMed1989

Allogeneic bone marrow transplantation versus chemotherapy in the treatment of childhood acute lymphoblastic leukemia in second complete remission.

Seventy-six patients between the ages of 2 and 17 years with acute lymphoblastic leukemia (ALL) achieved a second complete remission induced by polychemotherapy. Twenty-one had an HLA-identical donor and underwent allogeneic bone marrow transplantation (BMT) after conditioning with total body irradiation and cyclophosphamide. The remaining 55 patients lacked a suitable donor and received intensive chemotherapy as treatment. Fifteen patients were excluded from the analysis because they relapsed within 3 months after achieving a second complete remission. Three of the 21 BMT patients died of transplant-related complications and seven relapsed between 90 and 480 days after transplantation. Eleven patients are alive and disease free at 5.5-71 months with an actuarial survival of 47.1%; eight patients are on a plateau extending from 22 to 71 months. Thirty-three patients treated with chemotherapy died from relapse and seven are alive and disease free 7.5-99 months from the second remission, with an actuarial survival of 9%. The probability of survival was significantly higher in the BMT group (p less than 0.025). The probability of remaining in complete remission in the BMT group was 58.5% versus 10.9% in the chemotherapy group (p less than 0.005). Our results show that BMT is the best alternative therapy for children affected by ALL who have had a relapse in the marrow.

Adolescent↗
PubMed1988

An epizootic of blindness and encephalitis associated with a herpesvirus indistinguishable from equine herpesvirus I in a herd of alpacas and llamas.

Blindness characterized by dilated unresponsive pupils and funduscopic evidence of varying degrees of vitritis, retinal vasculitis, retinitis, chorioretinitis, and optic neuritis developed in 21 alpacas and 1 llama within a 30-day period. The animals were part of a group of approximately 100 animals imported from Chile one year earlier. The animals had spent 6 months in quarantine and then, for the 6 months preceding the epizootic, were housed at an exotic animal import-export farm, where the disease developed. Four of the affected animals also had signs of neurologic dysfunction. A herpesvirus indistinguishable from equine herpesvirus I was isolated from 4 of the affected animals, and antibody titers diagnostic for equine herpesvirus I were demonstrated in the serum of all but one of the affected animals.

Animals↗
PubMed1988

Pelvic exenteration for carcinoma of the cervix: analysis of 252 cases.

We present the results of 252 pelvic exenterations for primary and recurrent carcinoma of the cervix at the Hospital General de Mexico, a tertiary-care institution for the indigent. Emphasis is placed on the morbidity and mortality of the procedure in relation to patient selection. In underdeveloped countries, where early detection of cervical cancer is a rare event, pelvic exenteration must continue in the armamentarium of physicians; it can be associated with gains in the quality of life, with long-term survival, with effective rehabilitation, and possibly with cures.

Adult↗
PubMed1988

Valsalva maneuver: a test of the functional state of cardiac innervation in Chagasic myocarditis.

The ratio between maximal and minimal R-R intervals measured during the Valsalva maneuver is an adequate means of studying the functional state of the cardiac parasympathetic nervous system. We studied the changes in heart rate evoked during the Valsalva maneuver in 49 asymptomatic Chagasic patients with different degrees of myocardial involvement. The Chagasic patients were divided in three groups. Twelve patients had no evidence of heart disease except for an abnormal myocardial biopsy. Sixteen patients had a normal electrocardiogram but revealed evidence of localized myocardial damage as shown by left ventricular cineangiography. Twenty-one patients had abnormal electrocardiograms and revealed multiple areas of abnormal left ventricular wall motion. The Valsalva ratio (mean +/- standard error) was 1.62 +/- 0.12 for controls, 1.52 +/- 0.10 for those with an abnormal biopsy, 1.48 +/- 0.06 for those with localized myocardial damage, and 1.31 +/- 0.04 for those with an abnormal electrocardiogram. There were no statistically significant differences between the control group (normal sero-negative subjects) and those patients with normal electrocardiograms. Results in those with an abnormal electrocardiogram, however, were statistically different (P less than 0.05) from the other groups. These results are in discordance with the commonly accepted hypothesis that cardiac parasympathetic denervation causes a dilated myocardiopathy in patients with chronic Chagasic myocarditis.

Adult↗