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Biomedical subjects

A Torres

Publications and source records attributed to A Torres.

At least 163 records · Page 9Linked to original sources
PubMed2001

Reappraisal of the aetiology and prognostic factors of severe acute respiratory failure in HIV patients.

The introduction of highly active antiretroviral therapy with protease inhibitors in 1996 has changed the morbidity and mortality of acquired immune deficiency syndrome patients. Therefore, the aetiologies and prognostic factors of human immunodeficiency virus (HIV)-infected patients with life-threatening respiratory failure requiring intensive care unit (ICU) admission need to be reassessed. From 1993 to 1998, we prospectively evaluated 57 HIV patients (mean+/-SEM age 36.5+/-1.3 yrs) admitted to the ICU showing pulmonary infiltrates and acute respiratory failure. A total of 21 and 30 patients were diagnosed as having Pneumocystis carinii and bacterial pneumonia, respectively, of whom 13 and eight died during their ICU stay (p=0.01). Both groups of patients had similar age, Acute Physiology and Chronic Health Evaluation (APACHE) II score, and severity in respiratory failure. The number of cases with bacterial pneumonia admitted to ICU decreased after 1996 (p=0.05). Logistic regression analysis showed that (APACHE) II score >17, serum albumin level <25 g.(-1), and diagnosis of P. carinii pneumonia were the only factors at entry associated with ICU mortality (p=0.02). Patients with bacterial pneumonia are less frequently admitted to the intensive care unit after the introduction of highly active antiretroviral therapy with protease inhibitors in 1996. Compared to the previous series, it was observed that the few Pneumocystis carinii pneumonia patients that need intensive care still have a bad prognosis.

AIDS-Related Opportunistic Infections↗
PubMed2001

Systemic inflammatory response after bronchoalveolar lavage in critically ill patients.

Bronchoscopic bronchoalveolar lavage (BAL) may be followed by a systemic inflammatory response. Previous reports have suggested pneumonia as a predisposing condition and systemic cytokines as possible mediators. To test this hypothesis, systemic levels of interleukin (IL)-1beta, IL-6 and tumour necrosis factor-alpha (TNF-alpha) were studied before and at 12 h and 24 h after bronchoscopically guided BAL in 30 mechanically ventilated patients (median age 67 (range 54-76) yrs, simplified acute physiology score II (SAPS II) 33 (12-56)), 20 of whom had pneumonia and 10 of whom were control patients without pneumonia. Arterial oxygen partial pressure to inspired oxygen fraction ratio (Pa,O2/FI,O2), body temperature, mean arterial pressure, and cardiac frequency were recorded. The majority of patients (28/30, 93%) received antibiotic treatment prior to the procedure. Pa,O2/FI,O2 ratio was lower at 12 h compared to baseline in patients with pneumonia (baseline median 192 (range 65-256); 12 h 160 (66-190) mmHg, p<0.001) and ventilated controls (baseline 293 (205-473); 12 h 226 (153-330) mm Hg p=0.011), but returned to baseline levels at 24 h (pneumonia: 194 (92-312), p=0.991; controls: 309 (173-487) mmHg, p=0.785). No changes in other clinical variables were observed. Systemic TNF-alpha levels before BAL (pneumonia: 35 (10-88); controls: 17 (0-33) pg x mL(-1)) did not increase at 12 h (pneumonia: 35 (0-64); p=0.735; controls: 16 (0-21) pg x mL(-1), p=0.123 comparison to baseline) or 24 h (pneumonia: 31 (0-36), p=0.464; controls: 19 (0-43) pg x mL(-1), p=0.358). No changes of IL-1beta (baseline: pneumonia 0 (0-13); controls 1 (0-32) pg x mL(-1)) or IL-6 (baseline: pneumonia, 226 (9-4300); controls, 53 (0-346) pg x mL(-1)) were detected. No deterioration of clinical variables and no increase in systemic cytokine release has been observed after bronchoalveolar lavage, in critically ill patients. The potential cytokine increase is probably too small, in relation to the pre-existing inflammatory response, to yield clinical significance in this population otherwise antibiotic therapy may have been protective.

Aged↗
PubMed2001

Microbial investigation in ventilator-associated pneumonia.

Ventilator-associated pneumonia (VAP) is a serious infectious condition in intensive care unit (ICU) patients, currently related to a high mortality rate. Therefore, this complication of mechanical ventilation requires a prompt diagnosis and adequate antibiotic treatment. The detection of the causative organism is imperative for guiding an appropriate therapy as there is strong evidence of the adverse effect of inadequate empirical treatment on outcome. The major difficulty of the microbial investigation is to obtain the sample from the lower respiratory tract, mainly because of the potential contamination with upper airways flora, which may result in a misinterpretation of the cultures. Microbial investigation in VAP is based on the culture of samples obtained from lower respiratory tract by noninvasive or invasive methods. The most common techniques of sampling are the endotracheal aspirate (ETA), which is considered a noninvasive method, the protected specimen brush (PSB) and the bronchoalveolar lavage (BAL), both being invasive methods of investigation. The latter were designed as an attempt to avoid the colonizing flora of the upper airways. The best of these diagnostic approaches is still controversial. In terms of outcome, there is strong evidence that the impact of both invasive and noninvasive methods seems to be similar. In terms of cost, however, the endotracheal aspirate is less expensive compared to BAL or PSB. On the other hand, invasive methods could be particularly beneficial in patients who are not responding to the initial empirical antibiotic treatment. The rationale for the quantitative culture of the respiratory samples is to differentiate between infection and colonization of lower airways, because the bacterial colonization is a frequent event in mechanically ventilated patients. The thresholds currently employed for the diagnosis of the pneumonia are the following: ETA samples, > or = 10(5)-10(6) colony forming units (cfu).mL(-1); PSB samples, > or =10(3) cfu.mL(-1); and BAL samples, > or =10(4) cfu.mL(-1). Intending to provide a practical approach to the issue, the present manuscript reviews the available noninvasive (blood culture, endotracheal aspirate) and invasive (protected specimen brush, bronchoalveolar lavage, blinded methods and lung biopsy) techniques used for the diagnosis of ventilator-associated pneumonia.

Bacteriological Techniques↗
PubMed2001

Effect of endurance running on cardiac and skeletal muscle in rats.

We studied the effect of resistance running on left cardiac ventricle size and rectus femoris muscle fiber composition. Ten male Wistar rats were trained on a treadmill 6 days per week for 12 weeks. Ten rats remained sedentary and served as controls. A higher endurance time (40%) and cardiac hypertrophy in the trained animals were indicators of training efficiency. Morphometric analysis of the left ventricle cross-sectional area, left ventricular wall, and left ventricular cavity were evaluated. The endurance-running group demonstrated a hypertrophy of the ventricular wall (22%) and an increase in the ventricular cavity (25%); (p<0.0001). Semi-quantitative analysis of rectus femoris fiber-type composition and of the oxidative and glycolytic capacity was histochemically performed. Endurance running demonstrated a significant (p<0.01) increase in the relative frequency of Type I (24%), Type IIA (8%) and Type IIX (16%) oxidative fibers, and a decrease in Type IIB (20%) glycolytic fibers. There was a hypertrophy of both oxidative and glycolytic fiber types. The relative cross-sectional area analysis demonstrated an increase in oxidative fibers and a decrease in glycolytic fibers (p<0.0001). Changes were especially evident for Type IIX oxidative-glycolytic fibers. The results of this study indicate that the left ventricle adapts to endurance running by increasing wall thickness and enlargement of the ventricular cavity. Skeletal muscle adapts to training by increasing oxidative fiber Type. This increase may be related to fiber transformation from Type IIB glycolytic to Type IIX oxidative fibers. These results open the possibility for the use of this type of exercise to prevent muscular atrophy associated with age or post-immobilization.

Animals↗
PubMed2001

Bovine somatotropin dose titration in lactating dairy ewes. 3. Treatment interval.

Seventy-four lactating dairy ewes were injected with recombinant bovine somatotropin (bST; sometribove) in a sustained-release formulation. Ewes received 0, 80, 160, or 240 mg of bST/14 d at the end of 2, 4, and 6 wk postlambing, after which injections were withheld for a 28-d period. Response of milk production to bST presented a positive linear contrast and a negative quadratic contrast. After the final injection of bST (d 0), an increase in daily milk production was observed until d +9. A continuous decrease followed with milk production returned to control levels on d +11, +18, and +20, for 80, 160, and 240 mg of bST/14 d. Milk protein content decreased gradually until d +8 before it returned to control levels on d +12, +14 and +14, for 80, 160, and 240 mg of bST/14 d. Levels of bST and IGF-I in plasma presented positive and highly significant linear contrasts and negative quadratics which were significant only for bST. Relative to the evolution of milk production, the evolution of IGF-I levels in plasma was more similar than that of bST, although the correlation of each measure with milk production was high and highly significant. It was concluded that the period between successive injections should be shorter the lower the dose employed; however, a 14-d period seemed to correspond correctly for the dosages and hormone formulation tested.

Animals↗
PubMed2001

Assessment of hematologic progenitor engraftment by complete reticulocyte maturation parameters after autologous and allogeneic hematopoietic stem cell transplantation.

BACKGROUND AND OBJECTIVES: Hematopoietic restoration after marrow ablation is initiated by the erythroid compartment. However, the absolute microscope counts or corrected percentage of reticulocytes have proven to be poor markers of hematopoietic engraftment. Some reports have highlighted the usefulness of automatic flow cytometry methods to determine highly fluorescent reticulocytes, or mean fluorescence index. In this series of 60 hematopoietic stem cell transplants, we sought the normal kinetics throughout the post-transplant period of the following reticulocyte maturing parameters: highly fluorescent reticulocytes (RETH), immature reticulocyte fraction (IRF), mean fluorescence index (MFI) and also mean reticulocyte volume (MRV). DESIGN AND METHODS: Sixty consecutive patients undergoing allogeneic bone marrow (30 cases) and autologous mobilized stem cell transplantation (30 cases) were studied. Parameters of reticulocyte maturation were measured every other day from the beginning of the conditioning regimen until myeloid engraftment. RESULTS: Nadir values for the analyzed reticulocyte parameters were found between days +4 and +7 and thereafter, increases in these reticulocyte parameters appeared earlier than the rise in neutrophils. We considered erythroid engraftment to have occurred on the day when RETH reached 3%, IRF 10%, MFI 10 and MRV 110 fL. These cut-offs were assigned considering the 25% quartile for each parameter on the day that the myeloid engraftment occurred. The median engraftment days for RETH were +9 and +16, for IRF +9 and +13, for MFI +9 and +13 and for MRV +11 and +13 in autologous and allogeneic procedures, respectively. When compared to standard neutrophil engraftment, IRF and MFI engraftment occurred significantly earlier in all patients. Remarkably, we found a statistical correlation between the day a reticulocyte parameter reached its cut-off and the subsequent day of absolute neutrophil count (ANC) recovery for MFI after allogeneic transplants and for MRV after autologous procedures (p < 0.001 and p= 0.02, respectively). Of all the clinical parameters tested, only the number of infused CD34 cells showed a statistical influence on erythroid engraftment in autologous transplant. INTERPRETATION AND CONCLUSIONS: Early reticulocytes appear sooner than neutrophils after both autologous and allogeneic transplants, and any determined reticulocyte parameter can reliably measure this fraction. Nevertheless, our results show that MRV and MFI cut-offs are useful for determining subsequent myeloid engraftment. These findings could be relevant to decision-making in those patients with primary graft failure heralded by an absence of increasing values of MFI and MRV, indicating very low production of reticulocytes from the graft, who could, therefore, benefit from earlier rescue therapy.

Adolescent↗
PubMed2001

Signal transduction pathways underlying the expression of tissue factor and thrombomodulin in promyelocytic cells induced to differentiate by retinoid acid and dibutyryl cAMP.

Acute promyelocytic leukaemia (APL) may be associated with disseminated intravascular coagulation, as a result of increased tissue factor (TF) expression and reduced thrombomodulin (TM) expression by APL blast cells. During retinoid acid (RA)- and dibutyryl cAMP (dbcAMP)-induced differentiation of the APL cells, there is a marked up-modulation of both the protein kinase A (PKA) and C (PKC) activities. In order to further assess whether these kinases are intimately associated with both the differentiation process and the regulation of TF and TM expression, we have correlated the modulation of their respective pathways with the extent of differentiation and modulation of these cellular receptors. NB4 cells were incubated with all-trans-RA (ATRA) or dbcAMP for up to 48 h. The contribution of phospholipase C (PLC), inositol phosphate (IP), PKC and PKA in the expression of CD11b, TF and TM was studied by the use of specific inhibitors. Myo-inositol uptake and PKC activity increased in cells induced to differentiate by ATRA but the retinoid did not affect cAMP levels or PKA activity. Under treatment with dbcAMP, PKA activity was increased while inositol uptake and PKC activity remained unchanged. Our results show that the effects of ATRA and dbcAMP on promyelocytic cells are closely related, respectively, to the PLC/IP/PKC and the cAMP/PKA pathways. In cells induced to differentiate by ATRA, CD11b expression seems more closely related to inositol uptake than to PKC activity while the expression of TF and TM show the opposite pattern, which suggests cellular events regulated at a different level within a common signal transduction pathway.

Bucladesine↗
PubMed2001

Contribution to the development of the stapedius muscle structure in human fetuses.

The purpose of this report is to contribute to the knowledge of the morphogenesis of the human stapedius muscle. We have studied the stapedius structure development in 17 temporal bones from human fetuses. Chronological ages were from 48 days (21 mm) to 29 weeks (270 mm). Samples were fixed in 10% formol, decalcified with 2% nitric acid, embedded in Paraplast, sectioned in sequence of 7 microns and were stained with haematoxylin & eosin and Martins' trichrome. Four maturation stages were observed in the development of the stapedius muscle structure. First, the formation of the 'primordium muscularis' in the mesenchyme of the tympanic cavity (promyoblasts) was observed in a 36-mm embryo. Second, its differentiation into myoblasts, and its next cellular fusion to form muscle tubes, was seen in a 99-mm foetus. In the third stage, myofibrogenesis phenomena were developed, to synthesize, the myotube myoblasts, myofilaments, phenomena we observed that took place during the 14th to 17th weeks of development. The last stage was characterized by the presence of striated muscle fibres, at first intermingled with myotubes (18th to 26th weeks), until in the 29th week fetuses (270 mm) the skeletal muscle fibre was completely differentiated. We conclude that in the 29th week of development (270 mm) the stapedius muscle structure is completely differentiated, although the functional development is not complete until birth.

Embryonic and Fetal Development↗
PubMed2001

Remitting seronegative symmetrical synovitis with pitting edema associated with subcutaneous Streptobacillus moniliformis abscess.

We describe an 84-year-old woman who developed remitting seronegative symmetrical synovitis with pitting edema (RS3PE) associated with a subcutaneous abscess of the hand due to Streptobacillus moniliformis. Polyarthritis and edema were relieved after therapy with corticosteroids. We review the association of RS3PE to different rheumatologic, neoplastic, or infectious diseases.

Abscess↗
PubMed2001

Contributions to the study of the foetal development of physiological intimal thickening in the human uterine artery.

The morphological study of the development of "intimal thickenings" of the human uterine artery in physiological condition was performed on 72 uterine arteries obtained from foetuses from the 12th week of gestation up to birth. Our results indicate that intimal thickening is formed by the migration and displacement of mesenchymal cells around the site of origin of collateral vessel from uterine mesothelium. These cells firstly differentiate into the myoblasts and then into the myocites. During the development the internal limitans membrane separates the intimal thickening from the tunica media and the elastic fibres appearing inside possessing a muscle-elastic nature. The function of intimal thickenings is the regulation of local blood flow by means of the control of myocitic contractile capacity; these cells play a fundamental role in endothelium-intimal smooth muscle cell contact.

Arteries↗
PubMed2001

[Influence of age and gender on plasma norepinephrine changes produced by orthostatic stress].

The aim of this work was to determine the effect of aging and gender on plasma norepinephrine (NE) response to orthostatic stress. Fifty-six men and sixty women non-smokers, sedentary, non-obese, were studied at supine and standing positions. On the basis of the age of the subjects, they were divided into three groups of either men or women. Group A, young, range 17-34 years, Group B, middle-age, range 40-60 years, and Group C: senescent, range 61-91 years. Senescent subjects had the highest absolute supine values of NE and significant differences between women and men were found in groups B Men: 298 +/- 15 pg/mL; Women: 348 +/- 14 pg/mL), and C (M: 386 +/- 29 pg/mL; W: 473 +/- 19 pg/mL), but not between young (M: 246 +/- 21 pg/mL; W: 261 +/- 18 pg/mL). NE increased markedly in response to the orthostatic stress but the relative (percentage) increases were smaller in the older subjects perhaps related to their elevated baseline levels. The highest percent positive variation was observed in group A (M: 85%; W: 82%). The oldest group (C), had the lowest variation (M: 23%; W: 21%). The relative increases in NE responses were not different in men and women. The orthostatic-induced variation in NE was negatively related to aging in both men and women (M: r = -0.654; p < 0.0001; W: r = -0.557; p < 0.0001). It is concluded that orthostatic stress induced rise of blood NE is attenuated by age but does not appear to be dependent on gender.

Adolescent↗