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Biomedical subjects

A Torres

Publications and source records attributed to A Torres.

At least 91 records · Page 5Linked to original sources
PubMed2003

Gastro-oesophageal reflux in mechanically ventilated patients: effects of an oesophageal balloon.

Gastro-oesophageal reflux (GOR) and bronchoaspiration of gastric content are risk factors linked with ventilator-associated pneumonia. This study was aimed at evaluating the effect of a nasogastric tube (NGT) incorporating a low-pressure oesophageal balloon on GOR and bronchoaspiration in patients receiving mechanical ventilation. Fourteen patients were studied in a semi-recumbent position for 2 consecutive days. Inflation or deflation of the oesophageal balloon was randomised. Samples of blood, gastric content, and oropharyngeal and bronchial secretions were taken every 2 h over a period of 8 h. A radioactively labelled nutritional solution was continuously administered through the NGT. The magnitude of both the GOR and bronchoaspiration was measured by radioactivity counting of oropharyngeal and bronchial secretion samples, respectively. Inflation of the oesophageal balloon resulted in a significant decrease of both GOR and bronchoaspiration of gastric content. This protective effect was statistically significant from 4 h following inflation throughout the duration of the study. This study demonstrates that an inflated oesophageal balloon delays and decreases gastro-oesophageal and bronchial aspiration of gastric content in patients carrying a nasogastric tube and receiving enteral nutrition during mechanical ventilation. Although the method was found to be safe when applied for 8 h, longer times should be considered with caution.

Aged↗
PubMed2003

Rapid urinary antigen test for diagnosis of pneumococcal community-acquired pneumonia in adults.

Streptococcus pneumoniae is suspected to cause an important proportion of community-acquired pneumonia (CAP) whose aetiology cannot be detected with conventional tests. In this study, the authors evaluated the diagnostic yield of a new immunochromatographic membrane test (ICT) for the detection of the S. pneumoniae antigen in the urine of patients admitted with diagnosed CAP. ICT was performed in unconcentrated and concentrated urine from all the patients. ICT was repeated 1 month after discharge in a group initially testing positive. The authors also studied the ICT in clinically stable human immunodeficiency virus type 1 (HIV1)-infected patients. S. pneumoniae antigen was detected in all of the 68 (100%) patients tested with definitive pneumococcal pneumonia. In five of these cases ICT was only positive when it had been performed on the patients. The S. pneumoniae antigen was also detected in 36 (69.2%) of 52 patients with probable pneumococcal pneumonia and in 50 of 277 (18%) patients without pneumococcal pneumonia. ICT remained positive in 16 (69.5%) of 23 patients, 1 month after hospital discharge. Nasopharyngeal colonisation with S. pneumoniae was detected in 8 (12%) of 68 clinically stable HIV1 infected patients, but none tested ICT positive. The Binax NOW it immunochromatographic membrane test is a rapid, sensitive and specific test for detecting pneumococcal community-acquired pneumonia in adults. The test may remain positive for several weeks after pneumococcal pneumonia.

Acquired Immunodeficiency Syndrome↗
PubMed2003

Community-acquired pneumonia in the elderly: Spanish multicentre study.

Community-acquired pneumonia (CAP) in the elderly has increased as a consequence of an overall increase of the elderly population. A controversy about the aetiology and outcome of CAP in this population still exists and more epidemiological studies are needed. A prospective, 12-month, multicentre study was carried out to assess the clinical characteristics, aetiology, evolution and prognostic factors of elderly patients (> or = 65 yrs) admitted to hospital for CAP. The study included 503 patients (age 76 +/- 7 yrs). The clinical picture lasted < or = 5 days in 318 (63%) and the main clinical features were cough (n = 407, 81%) and fever (n = 380, 76%). Aetiological diagnosis was achieved in 199 (40%) cases, with a definite diagnosis obtained in 164 (33%). Of the 223 microorganisms isolated the main agents found were Streptococcus pneumoniae in 98 (49%) and Haemophilus influenzae in 27 (14%). A total of 53 patients died (11%) and the multivariate analysis showed the following factors of bad prognosis: previous bed confinement, alteration in mental status, absence of chills, plasma creatinine > or = 1.4 mg x dL(-1), oxygen tension in arterial blood/inspiratorv oxygen fraction ratio < 200 at the time of admission, and shock and renal failure during the evolution. The results of this study may aid in the management of empiric antibiotic treatment in elderly patients with community-acquired pneumonia and the patients who have a greater probability of bad evolution may be identified based on the risk factors.

Aged↗
PubMed2003

C-reactive protein levels in community-acquired pneumonia.

The diagnostic value of C-reactive protein (CRP) admission serum levels as an indicator of the aetiology of community-acquired pneumonia (CAP) was evaluated. A cohort of 1,222 patients with CAP was assessed. CRP levels were analysed in 258 patients with a single aetiological diagnosis. The mean CRP values in patients with pyogenic, atypical, viral and Legionella pneumophila pneumonia were: 16 mg x dL(-1), 13 mg x dL(-1), 14 mg x dL(-1) and 25 mg x dL(-1), respectively. CRP levels were not significantly different among patients outcome research team (PORT) groups (19 mg x dL(-1) in groups I-II, 16 mg x dL(-1) in group III and 16 mg x dL(-1) in groups IV-V). A cut-off point of 25 mg x dL(-1) had a sensibility, specificity, positive predictive value and negative predictive value of 0.6, 0.83, 0.3, and 0.94, respectively. After controlling for age and PORT score, the odds of having a CRP level >25 mg x dL(-1) was 6.9 times higher in patients with L. pneumophila pneumonia than in those with non-L. pneumophila pneumonia. Patients with Legionella pneumophila pneumonia had higher C-reactive protein levels than those with pneumonia of any other aetiology, independently of severity of infection. Being a cheap and readily available test, C-reactive protein may be a useful adjunctive procedure in the diagnosis of community-acquired pneumonia.

Aged↗
PubMed2003

Detection limits of antimicrobials in ewe milk by delvotest photometric measurements.

The Delvotest method detection limits per manufacturer's instructions at a fixed reading time of 3 h for 24 antimicrobial agents were determined in ewe milk by photometric measurement. For each drug, eight concentrations were tested on 20 ewe milk samples from individual ewes. Detection limits, determined by means of logistic regression models, were (microg/kg): 3, amoxycillin; 2, ampicillin; 18, cloxacillin; 1, penicillin "G"; 34, cefadroxil; 430, cephalosporin "C"; 40, cephalexin; 20, cefoperazone; 33, Ceftiofur; 18, cefuroxime; 6100, streptomycin; 1200, gentamycin; 2600, neomycin; 830, erythromycin; 100, tylosin; 180, doxycycline; 320, oxytetracycline; 590, tetracycline; 88, sulfadiazine; 44, sulfamethoxazole; 140, sulfametoxypyridazine; 48, sulfaquinoxaline; 12,000, chloramphenicol; and 290, trimethoprim. Whereas the beta-lactam antibiotics, sulphonamides, and tylosin were detected by Delvotest method at levels equal to those of maximum residue limits, its sensitivity needs to be enhanced to detect aminoglycosides, tetracyclines, streptomycin, chloramphenicol, and trimethoprim residues in ewe milk or to develop an integrated residue detection system for ewe milk with different sensitive microorganisms for each group of antiinfectious agents.

Aminoglycosides↗
PubMed2003

Evaluation of screening test for detection of antimicrobial residues in ewe milk.

The effects of preservatives (potassium dichromate and sodium azide), heat treatment (untreated and 82 degrees C/10 min), and lactation stage upon the response of the microbial tests (BRT AiM and Delvotest) utilized for the detection of residues of antimicrobial substances in ewe milk were examined. Milk samples were collected from the morning milking of 50 Manchega ewes every 2 wk, from 15 d postpartum until the end of lactation. A total of 2322 samples were analyzed by BRT AiM with prediffusion and Delvotest microbial tests. The specificity of preservative-free milk samples without heat treatment was high (96.3% for BRT and 97.7% for Delvotest), with results improving for those samples thermally treated at 82 degrees C/10 min (99.0% for BRT and 98.7% for Delvotest). Potassium dichromate produced a total inhibition of growth of Bacillus stearothermophilus with both methods. When acidiol was utilized, the specificity of the samples not treated thermally was lower compared with preservative-free milk samples for the BRT AiM (90.2%) and Delvotest (91.0%) methods, improving when the samples were thermally treated, both for BRT AiM (94.8%) and Delvotest (95.3%), given that the presence of the preservative increased the frequency of doubtful results. The lactation stage significantly affected the results of the methods, with a greater frequency of false-positive and doubtful cases toward the end of the cycle, especially in those samples preserved with acidiol. The greater selectivity in both methods was therefore obtained for preservative-free ewe milk samples with prior heat treatment taken at the beginning or in midlactation period.

Animals↗
PubMed2003

[Bone metabolism alterations after kidney transplantation].

Early after renal transplantation (RT) a rapid decrease in bone mineral density at the lumbar spine, femoral neck, and femoral shaft has been documented. In addition, an appreciable proportion of patients still remain losing bone late after RT. As a consequence, RT patients are at a high risk of bone fractures as compared to general population. Most fractures involve appendicular skeleton, particularly the feet and ankles, and the diabetic patient is at increased risk of fractures. Thus, early institution of preventive measures and treatment of established osteoporosis are central. The major cause of post-transplantation bone loss is corticosteroid treatment, and this should be used at the lower dose compatible with graft survival. Preexisting hyperparathyroidism also affects the early cancellous bone loss at the spine, and post-transplantation bone loss reflects variable individual susceptibility, resembling the polygenic determination of bone mineral density in general. Clinical trials have demonstrated that bisphosphonates or vitamin D plus calcium supplementation, prevent post-transplantation bone loss during the first 6-12 months. However, their role in preventing bone fractures has not been proven. Finally, recommendations for management, prevention and treatment, are summarized.

Absorptiometry, Photon↗
PubMed2003

[Immunoallergic interstitial nephritis vs. cholesterol atheroembolism. Differentiating characteristics].

The commonest clinical presentation of both immunoalergic interstitial nephritis (IIN) and atheroembolic renal disease (ATD) is an acute renal failure accompanied by skin lesions and eosinophilia. As a consequence, differential diagnosis between both entities is often very difficult. We have performed a comparative retrospective study of those patients diagnosed as having IIN or ATD in our Hospital in the period 1980-2000. A total of 42 patients have been diagnosed of IIN and 16 of ATD. Demographic data, as well as clinical and laboratory parameters and outcomes of every studied patient were analysed. We found a significantly higher prevalence of male sex (100% vs 57%, p < 0.01), previous history of hypertension (100% vs 55%, p < 0.01), chronic renal insufficiency (56% vs 17%, p < 0.01), ischemic heart disease (56% vs 14%, p < 0.001), peripheral ischemic disease, endovascular procedures (87% vs 7%, p < 0.001) and anticoagulant treatments (25% vs 5%, p < 0.001) among patients with ATD as compared with IIN, respectively. On the contrary, previous infections (45% vs 12%, p < 0.01) and exposure to new drugs (100% vs 40%, p < 0.001) were significantly more frequent among IIN patients in compare with ATD. ATD patients showed skin lesions consisting of livedo reticularis and digital infarcts (63% vs 31%, p < 0.05) accompanied by blood pressure increase (100% vs 24%, p < 0.001), whereas IIN patients showed fever (41% vs 19%, p < 0.05) and cutaneous rash as significant clinical manifestations, respectively. The number of ATD patients with proteinuria > 1 g/24 h was significantly higher, but no differences between both groups in the prevalence of urinary sediment abnormalities were observed. The prevalence of absolute eosinophilia was high in both groups (88% among ATD patients, 64% among IIN patients; pNS). Prognosis of both entities was clearly different: Almost all patients with ATD died (69%) or evolved to end-stage renal failure, whereas most patients with IIN showed a recovery of renal function after withdrawal of responsible drugs and steroid treatment. In summary, the analysis of clinical and laboratory data allows an initial differential diagnosis in patients suspected as having IIN or ATD.

Acute Kidney Injury↗
PubMed2002

Detrimental effect of protracted hyperglycaemia on beta-cell neogenesis in a mouse murine model of diabetes.

AIMS/HYPOTHESIS: Previous studies have shown that new beta cells differentiate from intra-islet precursors in pancreatic islets of mice in which diabetes is induced by injecting a high dose of the beta-cell toxin streptozotocin. Moreover, the re-establishment of euglycaemia by insulin therapy 1 day after streptozotocin treatment improved the process of regeneration. We sought to assess whether a 1-week delay in the restoration of euglycaemia would affect beta-cell regeneration. METHODS: Adult CD-1 mice were injected with 200 mg/kg of streptozotocin. One group of mice remained hyperglycaemic throughout the experiment while a second group became normoglycaemic following the administration of insulin therapy 1 week after the injection of streptozotocin. Pancreata removed at different times after treatment were processed for visualization ofbeta precursor-cell markers and insulin by confocal microscopy. RESULTS: New beta cells appeared in islets of streptozotocin-treated mice after restoration of normoglycaemia. Like islets of streptozotocin mice in which blood glucose concentrations were rapidly restored, islets of mice that became normoglycaemic 1 week after streptozotocin treatment also had two potential insulin precursor cell types. Protracted hyperglycaemia however, had several harmful effects on insulin cell neogenesis, such as a reduction in the number of euglycaemic mice with successful beta-cell regeneration and a decrease in the number and survival of the newly differentiated insulin-containing cells. CONCLUSION/INTERPRETATION: These results indicate that islets gradually lose their regenerative potential when they are exposed to high circulating glucose concentrations for an extended period of time.

Animals↗
PubMed2002

Parameters related to oxygen free radicals in erythrocytes, plasma and epidermis of the hairless rat.

The following parameters related to oxygen free radicals (OFR) were determined in erythrocytes and the epidermis of hairless rats: catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), reduced (GSH) and oxidized (GSSG) glutathione, glutathione S-transferase (GST), superoxide dismutase (SOD) and thiobarbituric acid reactive substances (TBARS). GSH, GSSG and TBARS were also analyzed in plasma. In erythrocytes, the Pearson correlation coefficients (r) were significant (p < 0.001) between glutathione and other parameters as follows: GSH correlated negatively with GSSG (r = -0.665) and TBARS (r = -0.669); GSSG correlated positively with SOD (r = 0.709) and TBARS (r = 0.752). Plasma GSSG correlated negatively with erythrocytic thermostable GST activity (r = -0.608; p=0.001) and with erythrocytic total GST activity (r = -0.677; p < 0.001). In epidermis (p < 0.001 in all cases), GSH content correlated with GSSG (r = 0.682) and with GPx (r = 0.663); GSSG correlated with GPx (r = 0.731) and with GR (r = 0.794). By multiple linear regression analysis some predictor variables (R(2)) were found: in erythrocytes, thermostable GST was predicted by total GST activity and GSSG, GSSG content was predicted by GSH and by the GSH/GSSG ratio and GPx activity was predicted by GST, CAT and SOD activities; in epidermis, GSSG was predicted by GR and SOD activities and GR was predicted by GSSG, TBARS and GPx. It is concluded that the hairless rat is a good model for studying OFR-related parameters simultaneously in blood and skin, and that it may provide valuable information about other animals under oxidative stress.

Animals↗
PubMed2002

Intrapulmonary neutrophil apoptosis in a pig model of pneumonia.

BACKGROUND: Apoptosis and necrosis are two distinct cell death modalities. Polymorphonuclear leukocytes (PMNL) play an important role in pneumonia and little information is available on whether these cells are cleared by necrosis or apoptosis. We therefore compared the proportion of apoptotic PMNL in lung tissues with and without pneumonia. In addition, the association of PMNL apoptosis and mechanical ventilation (MV) was investigated. METHODS: Samples obtained from a pig model developed to tracheobronchial stenting were analysed. Pneumonia was induced with that model in 10 animals (white-Landrace piglets, Pittman-Moore or Göttingen minipigs). Animals were sacrificed when clinical parameters of pneumonia became evident and 17 lung samples could be analysed for histologic evidence of pneumonia, growth of micro-organisms, and the apoptotic index (proportion of apoptotic PMNL over all PMNL in a 400-power field). In addition, lung samples (n = 7) from two pigs without stent implantation on mechanically ventilated for more than 48 h were studied. RESULTS: A total of 9/17 samples (53%) showed histologic evidence of pneumonia, 11/17 (65%) had significant bacterial growth (> 10(3) cfu/g), and 7/17 (41%) fulfilled both criteria. The apoptotic index was not significantly different in samples with and without histologic evidence of pneumonia (pneumonia: 25.3 +/- 6.1% vs. No pneumonia: 25.2 +/- 11.9%; 95%CI: -9.7 - 9.5, p = 0.989) or in samples with and without significant bacterial growth (significant bacterial growth: 23.5+/-9.3% vs. No significant bacterial growth: 28.5+/-8.2%; 95%CI: -4.6 - 16.7; p = 0.284). However, the apoptotic index was higher in samples of pigs, mechanically ventilated for more than 48 h, compared to the stent group (MV: 36.9+/-10.7% vs. Stent: 25.2 +/- 9.0%; 95% CI: -20.5 - -2.9; p = 0.012). CONCLUSION: In an animal model, the proportion of apoptotic PMNL was not different in lung samples with and without histologic or bacterial pneumonia. However, MV for more than 48 h was associated with a higher proportion of apoptotic PMNL in lung tissue. This study may be helpful for the understanding of the evolution of lung tissue damage induced by bacterial pneumonia and MV.

Animals↗
PubMed2002

Morphometric study of testis of Wistar rat after open-ended vasectomy.

The effects on the testis of open-ended vasectomy in the Wistar rat have been assessed morphometrically and evaluated statistically at 1, 4, 12, and 24 weeks after operation, and compared to those in sham-operated controls. The open-ended technique, ie, without ligation of the epididymal end of the cut ductus deferens, allowed drainage of sperm into the spermatic cord. During the period of our study, it did not affect the structure of the testis; although the germinal epithelium, basement membrane, and the stroma and cells of the interstitial space all showed variations when compared to the control group, these were not statistically significant.

Animals↗
PubMed2002

Efficacy and tolerability of once-daily telithromycin compared with high-dose amoxicillin for treatment of community-acquired pneumonia.

BACKGROUND: This randomized, double-blind study compared the efficacy and tolerability of the new ketolide antimicrobial telithromycin with that of high-dose amoxicillin in the treatment of community-acquired pneumonia (CAP). PATIENTS AND METHODS: Adult patients (n = 404), with signs and symptoms of CAP and radiologic confirmation were randomized to receive telithromycin 800 mg once daily (n = 199) or amoxicillin 1,000 mg three times a day (n = 205) for 10 days. Clinical and bacteriologic outcomes were assessed at post-therapy test-of-cure (days 17-24) and late post therapy (days 31-36). RESULTS: The clinical cure rate for telithromycin-treated patients (per protocol) pst therapy (days 17-24) was 141/149 (94.6%) and compared well with that for amoxicillin (137/152 (90.1%)). Subset analysis of patients (per protocol) showed high clinical cure rates for patients aged >/= 65 years (telithromycin 21/24, 87.5%; amoxicillin 22/29, 75.9%); those with documented pneumococcal bacteremia (telithromycin 10/10, 100%; amoxicillin 7/9, 77.8%); and patients with a Fine score >/= III (telithromycin 31/34, 91.2%; amoxicillin 38/47, 80.9%). Bacterial eradication rates were comparable between treatments (telithromycin 42/48, 87.5%; amoxicillin 39/45, 86.7%), with 22/23 vs 18/21 Streptococcus pneumoniae strains 9/12 vs 11/13 Haemophilus influenzae strains and all Moraxella catarrhalis isolates (five and three patients, respectively) eradicated at the test-of-cure visit. Both treatments were generally well tolerated. CONCLUSION: Telithromycin 800 mg once daily is a convenient, optimal-spectrum, first-line treatment for CAP in adults, at least as effective and well tolerated as high-dose amoxicillin.

Adolescent↗