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Biomedical subjects

A Torres

Publications and source records attributed to A Torres.

At least 19 recordsLinked to original sources
PubMed1995

[Minimal residual disease in chronic myeloid leukemia in patients with long survival after allogeneic bone marrow transplantation].

BACKGROUND: The study of the minimum residual disease in a series of patients diagnosed with chronic myeloid leukemia (CML) treated with non manipulated allogeneic bone marrow transplantation (BMT) reporting a survival longer than 6 months is presented. METHODS: The positivity of the chimeric transcription bcr-abl was studied in 18 long surviving BMT patients. The complementary DNA (cDNA) corresponding to this transcription was amplified by the polymerase chain reaction (PCR) technique. Double internal PCR (PCR nested) was performed to increase the sensitivity of the determination. RESULTS: The first determination was performed in different post BMT stages with a median of 27 months (4-97). Fourteen out the 18 patients were positive for the bcr-abl transcription. On the second determination carried out in 11 cases with a sample obtained 24 months after the first 7 out of the 10 positive cases evaluated presented an identical pattern while the patient who originally was negative, remained so. The original transcription became negative in three patients. Only one of the positive cases developed hematologic relapse during the study period. CONCLUSIONS: Aggressive chemo-radiotherapy does not eradicate the leukemic clone in all patients with chronic myeloid leukemia. The persistence of positive results in a high number of patients with chronic myeloid leukemia in remission for over 6 months after bone marrow transplantation is not predictive of imminent relapse.

Adult↗
PubMed1995

Effect of temperature on opioid dependence and on the abstinence response in the isolated guinea pig ileum.

This paper explores, in the isolated guinea-pig ileum, the effects of temperature on the acute development of opioid dependence and on the precipitation of the abstinence response, using as reference the effect of temperature on the response to a standard nicotine concentration. Additionally, the influence of temperature on acute morphine neurodepression was examined. Three experimental groups were included. In the first, the bath temperature was adjusted and maintained along the experimental session (2.5 h) at one of the following values: 28, 32, 36 or 40 degrees C. In the second, the different values of bath temperature were applied only during the period of morphine exposure before testing the abstinence response at 36 degrees C. In the third, all segments were initially incubated at 36 degrees C for 1 h, and afterwards, abstinence and the nicotine response were elicited at the different temperatures mentioned. In all the series, a single challenge naloxone dose (3.1, 10, 31, 100, 316, 1000 or 3160 nM) was administered after 1h of morphine and complete naloxone concentration-response curves were obtained. The abstinence response was expressed as a percentage of the nicotine reference response. All segments showed robust nicotine responses at all the experimental protocols tested indicating that, at the temperature range studied, the contractile mechanisms were impaired. This study showed that changes in bath temperature modify the magnitude of acute morphine neurodepression, and of the abstinence response but did no affect the development of acute opioid dependence. These data, along with several lines of evidence, strongly suggest that acute neurodepression, the development of opiate dependence and antagonist-precipitated abstinence are separable. Results are discussed on the basis of drug-receptor interactions.

Acute Disease↗
PubMed1995

Bone disease in predialysis, hemodialysis, and CAPD patients: evidence of a better bone response to PTH.

The spectrum of bone disease in predialysis and dialysis patients has changed during the last decade. The incidence of aplastic bone disease has increased and this can not be attributed to bone aluminum deposition; moreover, low bone cellular activity is present despite a moderate elevation in PTH levels. This study compares PTH levels and types of bone disease in both predialysis and dialysis patients from the same geographical area. We prospectively studied 119 unselected end-stage renal disease patients: 38 were immediately predialysis (PreD), 49 on hemodialysis (HD), and 32 on CAPD. A bone biopsy was performed in all patients. Aplastic bone disease with < 5% bone surface aluminum was a common finding (48%, 32%, and 48%, in PreD, HD, and CAPD, respectively). In all groups, an intact PTH level below 120 pg/ml was highly predictive of low bone turnover. Conversely, a PTH level above 450 pg/ml was always associated with histologic features of hyperparathyroid bone disease. Among the bone histomorphometric parameters, osteoblast surface showed the best correlation with intact PTH in each group, and the slope of the regression line for this correlation was significantly steeper in HD and CAPD than PreD patients. Thus, the range of PTH (95% confidence limit bands) needed to obtain a normal osteoblast surface of 1.5% was greater in preD than in HD and CAPD patients (300 to 500 vs. 75 to 260 pg/ml, respectively). In all groups some degree of marrow fibrosis was observed when PTH levels were greater than 250 pg/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium↗
PubMed1995

Informed consent and informed refusal.

BACKGROUND: This article continues our medicolegal series that addresses issues affecting current dermatology practice. Informed consent and informed refusal have become cornerstones of modern American healthcare, and can serve to facilitate communication and trust between physician and patient. METHODS: A format with an initial discussion of legal concepts is followed by hypothetical problems and a review of actual cases to illustrate the principles of informed consent and informed refusal. RESULTS: A valid informed consent from a competent patient should be obtained before initiating most dermatologic treatment. When a competent patient refuses a recommended medical test or procedure, the physician should make sure the patient understands the potential negative consequences of refusal. Some form of written documentation in the medical record is advised in either situation. CONCLUSION: Failure to obtain a patient's informed consent prior to beginning treatment or failing to obtain an informed refusal before accepting a patient's decision to forego a test or procedure may subject the dermatologist to multiple later allegations, most commonly negligence.

Adult↗
PubMed1995

Use of elastin fibre detection in the diagnosis of ventilator associated pneumonia.

BACKGROUND: Elastin fibre detection could be a simple and reliable marker of ventilator associated pneumonia. To confirm this, a prospective study was undertaken to evaluate the diagnostic yield of elastin fibre detection in the diagnosis of ventilator associated pneumonia. METHODS: Seventy eight mechanically ventilated patients were evaluated by examining endotracheal aspirates for the presence of elastin fibres. All patients were previously treated with antibiotics. Quantitative bacterial cultures of endotracheal aspirates and protected specimen brush samples were also performed. Patients were classified into three diagnostic categories: group 1, definite pneumonia (n = 25); group 2, probable pneumonia (n = 35); and group 3, controls (n = 18). RESULTS: Patients with definite and probable pneumonia were grouped together. The presence of elastin fibres in endotracheal aspirate samples was more frequent in groups 1 and 2, being found in 19 of the 60 patients compared with five of the control group. Although the presence of elastin fibres had a low sensitivity (32%), it was a reasonably specific marker (72%) of pneumonia. This specificity increased to 86% and 81% respectively when only Gram negative bacilli and Pseudomonas aeruginosa pneumonia were considered. Again, calculated sensitivity was 43% and 44% when analysing cases infected by Gram negative bacilli and Ps aeruginosa, respectively. The negative predictive value of the detection of elastin fibres in pneumonia caused by Ps aeruginosa was 81%. Detection was more frequent with infection by Gram negative bacilli (14/19), particularly with Ps aeruginosa (8/14). By contrast, pneumonia due to Gram positive cocci or non-bacterial agents uncommonly resulted in positive elastin fibre preparations (4/19, 21%). When analysing patients with and without chronic obstructive pulmonary disease, the diagnostic value of elastin fibre detection did not change. CONCLUSIONS: Potassium hydroxide preparation of elastin fibres is a rapid and simple specific marker of ventilator associated pneumonia and may be a useful technique to help diagnose pulmonary infections in mechanically ventilated patients, although this assessment is at present limited to patients without adult respiratory distress syndrome.

Adult↗
PubMed1995

Prognostic factors influencing the outcome in pneumocystis carinii pneumonia in patients with AIDS.

BACKGROUND: Studies attempting to identify the prognostic factors that influence the outcome of Pneumocystis carinii pneumonia (PCP) in patients with AIDS using a multivariate analysis are few. In order to identify those prognostic factors amenable to medical intervention, univariate and multivariate analyses were performed on 102 patients with AIDS suffering a first episode of PCP. METHODS: One hundred and two consecutive patients with AIDS (51% drug abusers, 45% homosexuals, and 4% with other HIV risk factors) admitted to our institution between 1986 and 1989 whose respiratory infection was diagnosed by bronchoalveolar lavage were studied prospectively. RESULTS: The overall mortality was 28%, rising to 79% in those patients who required mechanical ventilation. According to univariate analysis the following variables were related to a poor prognosis: age > 35 years; risk factor for HIV infection other than drug abuse; and AIDS diagnosis confirmed before 1988; PaO2 < 8 kPa at admission; severe acute respiratory failure on admission (PaO2/FIO2 < 20 kPa); mechanical ventilation; antibiotic therapy for PCP other than trimethoprim-sulphamethoxazole; multiple microbial pulmonary infection; serum lactate dehydrogenase (LDH) > 22.5 mukat/l on admission; serum albumin level < 30 g/l. Multivariate analysis showed that only mechanical ventilation was independently associated with a poor outcome. CONCLUSIONS: The mortality of AIDS patients presenting with a first episode of PCP before 1990 was high (28%). The main prognostic factor associated with poor outcome was the requirement for mechanical ventilation due to severe acute respiratory failure.

AIDS-Related Opportunistic Infections↗
PubMed1995

Re-intubation increases the risk of nosocomial pneumonia in patients needing mechanical ventilation.

In order to confirm that re-intubation can be a risk factor of nosocomial pneumonia in mechanically ventilated patients, a case-control study was performed. Forty consecutive patients needing re-intubation were selected as cases. Each case was paired with a matched control for the previous duration of mechanical ventilation (+/- 2 d). Nineteen (47%) of the cases developed pneumonia after re-intubation compared with 4 (10%) of the controls (odds ratio [OR] = 8.5; 95% confidence interval [CI] 1.7 to 105.9; p = 0.0007). After adjusting for age, sex, and presence of prior bronchoscopy, the conditional logistic regression analysis demonstrated that re-intubation was the only significant factor related to the development of pneumonia (OR: 5.94; 95% CI 1.27 to 22.71; p = 0.023). Sixteen (73%) of the 22 patients lying semirecumbent during the interval between extubation and re-intubation developed nosocomial pneumonia versus three (16%) of the 18 in supine position (p = 0.001). These results indicate that semirecumbency during the period between extubation and re-intubation may play a role in nosocomial pneumonia development in patients who need re-intubation. Total intensive care unit stay (19.4 +/- 10 versus 13.9 +/- 11.9 days, p = 0.0008) and crude mortality (35 versus 20%, p = 0.14) were also higher in re-intubated patients when compared with controls. We conclude that re-intubation is a risk factor for ventilator-associated pneumonia and might be avoided in a substantial number of cases.

Case-Control Studies↗
PubMed1995

Semirecumbent position protects from pulmonary aspiration but not completely from gastroesophageal reflux in mechanically ventilated patients.

The aim of this study was to evaluate the effect of two body positions (supine and semirecumbency) on the dynamics of gastroesophageal reflux (GER) in 15 patients requiring mechanical ventilation and having a nasogastric tube in place. Samples of gastric contents, pharyngeal and bronchial secretions, and blood were obtained at baseline and every hour during a period of 5 h after nasogastric tube isotopic instillation of 37 megabecquerels of Tc99m. Radioactivity counting (RAc) was performed using a gamma counter with correction for decay. Irrespective of the body position, all patients showed at 3, 4, and 5 h after the isotope instillation a significant increase in RAc of the oropharyngeal contents (p < 0.05, each), indicating GER. Although RAc values in the pharynx were higher in supine from 1 through 4 h (p < 0.05), at the end of the study (5 h) the values did not differ between each position. Likewise, the slopes of the regression lines of sequential oropharyngeal RAc values were not different between each position (0.39 +/- 0.09 versus 0.45 +/- 0.11, respectively). In contrast, RAc values in bronchial secretions were higher at 5 h in the supine position compared with baseline (p < 0.05) and to semirecumbency (p < 0.01). These results strongly support that GER in mechanically ventilated patients with a nasogastric tube is a feature occurring irrespective of body position. Semirecumbent position does not protect completely from GER and subsequently from oropharyngeal colonization from gastric origin.

Cross Infection↗
PubMed1995

Diffuse alveolar hemorrhage in allogeneic bone marrow transplantation. A postmortem study.

To define better the syndrome of diffuse alveolar hemorrhage (DAH), we conducted a postmortem study in 77 patients who died of pulmonary complications, distributed into three groups. Group A included 47 patients with hematologic diseases treated with allogeneic bone marrow transplant (BMT); Group B, 20 patients with hematologic diseases treated with conventional chemotherapy; and Group C, 10 patients without hematologic diseases. The diagnosis of DAH was established when there was blood in at least 30% of the lung tissue evaluated without evidence of infection or any other pathologic change that could account for its presence. The presence of an associated pulmonary complication was considered only when there was normal lung parenchyma between both blood and the specific lesions. Diffuse alveolar hemorrhage was shown in 11 patients in Group A (23%) compared with 1 patient in Group B (5%) (p < 0.05). Of the 11 patients with DAH in Group A, 10 had some associated pulmonary complication: 7 presented with diffuse alveolar damage (DAD), 2 with associated bacterial pneumonia and 1 with invasive aspergillosis, 2 others had an associated cytomegalovirus (CMV) pneumonitis, and the remaining patients had an associated herpes pneumonia. There were no clinical differences between patients with and without DAH. Of 8 patients with confirmed DAH in Group A, who had been submitted to a bronchoscopic examination within 1 wk of death, 4 had normal BAL fluid; by contrast, 7 of 13 patients without DAH had hemorrhagic BAL fluid.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Role of bronchoalveolar lavage in the diagnosis of fat embolism syndrome.

Fat embolism syndrome (FES) is a serious clinical disorder occurring in trauma patients. The diagnosis of fat embolism syndrome may be difficult to establish clinically. We therefore wanted to investigate the usefulness of bronchoalveolar lavage (BAL) in the diagnostic evaluation of fat embolism syndrome. We analysed the presence of fat droplets in BAL cells in 32 trauma patients (7 with full diagnostic criteria of fat embolism syndrome, 17 with incomplete diagnostic criteria, and 8 with no diagnostic criteria at the time of bronchoscopy), 9 nontrauma patients with acute respiratory failure and radiographic pulmonary infiltrates, and a control group composed of 10 individuals. An increased percentage of oil red O positive alveolar macrophages (cut-off point > 3%) in BAL was found in 6 out of 7 patients with definite clinical criteria of fat embolism syndrome, and in 6 out of 20 trauma patients without the clinical diagnosis of fat embolism syndrome. In two patients with fat embolism syndrome, sequential BAL showed that the percentage of positive macrophages decreased when the clinical manifestations disappeared. An increased number of BAL macrophages with fat droplets was also observed in two trauma patients without evidence of fat embolism syndrome after long-bone surgical intervention. By contrast, all non-trauma patients had a percentage of positive cells lower than 3%. Our findings suggest that BAL oil red O positive macrophages are frequently observed in trauma patients irrespective of the presence of fat embolism syndrome. Conceivably, a high number of oil red O positive macrophages could reflect clinically silent fat embolization.

Adult↗
PubMed1995

Bovine somatotropin dose titration in lactating dairy ewes. 1. Milk yield and milk composition.

Seventy-four lactating dairy ewes were injected with recombinant bST (sometribove) in a sustained-release formulation. Ewes received 0, 80, 160, or 240 mg of bST every 14 d from wk 3 to 8 of lactation (part 1) and 0, 80, or 160 mg of bST every 14 d from wk 11 to 23 of lactation (part 2). Sometribove increased milk yield over that of the controls for all treatment groups. The increase was largest for the group that was administered 160 mg of bST: milk yield was 34.1 and 53.2% and 6% FCM was 36.9 and 51.8% for parts 1 and 2 of the study, respectively. Sometribove increased milk fat during part 1 of the study, but decreased milk fat during part 2. Protein contents of milk were decreased throughout the study. For all group, bST increased the yield of milk constituents over that of the controls. When milking frequency was reduced from twice to once daily, the difference in milk yield between control ewes and those treated with bST was maintained. Neither mastitis incidence nor milk SCC were affected by bST treatment. Recombinant bST is efficacious in increasing both actual milk yield and 6% FCM over the dose range of 80 to 240 mg/14 d without adverse effects for lactating ewes.

Animals↗
PubMed1995

Nonsteroidal human progesterone receptor modulators from the marine alga Cymopolia barbata.

The co-transfection assay is a novel functional assay using cells transiently transfected with plasmids encoding intracellular receptors and corresponding reporter genes. Using this assay, natural product extracts were tested to identify compounds that modulate intracellular receptor activity, measured as changes in reporter gene activity. A crude extract of the marine alga Cymopolia barbata was found to inhibit progesterone-stimulated reporter gene expression in cells transfected with the human progesterone receptor (hPR) and an appropriate reporter construct. Purification of the active constituents of the extract, guided by the co-transfection assay, yielded two diastereomers of cyclocymopol monomethyl ether, possessing opposing pharmacological activities with the hPR. The antagonist (3R)-cyclocymopol monomethyl ether (LG100127) blocked 1 nM progesterone-stimulated reporter gene expression with an IC50 value of 549 +/- 55 nM in the co-transfection assay. The agonist (3S)-cyclocymopol monomethyl ether (LG100128) had efficacy similar to that of progesterone and an EC50 value of 35 +/- 2 nM. Stimulation by progesterone of the hPR in the human breast cancer cell line T-47D results in enhanced expression of alkaline phosphatase; LG100127 blocked alkaline phosphatase expression stimulated either by progesterone or by LG100128, and LG100128 mimicked progesterone in this assay. Both diastereomers displaced [3H]progesterone from baculovirus-expressed hPR. LG100127 and LG100128 each interacted with the human androgen receptor but did not interact with the human glucocorticoid receptor, estrogen receptor, vitamin D receptor, or retinoid receptors. In summary, these in vitro studies describe the first nonsteroidal pharmacophores for the hPR and demonstrate the use of the co-transfection assay in their discovery.

Animals↗
PubMed1995

Community-acquired pneumonia in the intensive care unit.

CAP requiring ICU admission is a distinct clinical entity. The mortality rate of pneumonia in this subset of patients has been unchanged in the past several years. Aggressive diagnostic of strategies to establish the causative pathogens of pneumonia rapidly will enable clinicians to adjust antibiotic therapy appropriately. It is hoped that new adjunctive therapeutic options that positively influence host-related factors and bolster pulmonary antibacterial defense will result in reduced morbidity and mortality.

AIDS-Related Opportunistic Infections↗
PubMed1994

Prognostic significance of serum CA 125 antigen assay in patients with non-small cell lung cancer.

BACKGROUND: The serum levels of CA 125 tumor-associated antigen in patients with lung cancer have been previously related to TNM stage, histologic type, and survival rate. In the current study, the prognostic information provided by the CA 125 antigen assay was analyzed. METHODS: Preoperative serum of CA 125 antigen was determined in 137 patients with non-small cell lung cancer. The assay was performed by means of a solid-phase enzyme-immunoassay test. The influence of CA 125 serum level on postoperative outcome was studied by a multivariate analysis, performed with Cox's proportional hazards regression model. RESULTS: Patients whose initial CA 125 level was higher than 15 U/ml had a 3.25-fold greater likelihood of relapse (95% confidence interval [CI], 1.7-6.21) (P < 0.001) and a 4.27-fold greater likelihood of deaths (95% CI, 2.42-7.55) (P < 0.001) due to cancer than patients with lower values. For patients with serum levels over 15 U/ml, the 36-month survival rate posttreatment was lower (67% versus 20%) (P < 0.001), as was the disease-free rate (64% versus 13%) (P < 0.001). After adjustment for TNM stages, histologic type, sex, and age, patients with CA 125 values over 15 U/ml continued exhibiting higher risk of relapse (hazard ratio, 2.2; 95% CI, 1.04-4.69) (P = 0.04) and higher risk of death (hazard ratio, 2.42; 95% CI, 1.29-4.54) (P = 0.006). CONCLUSIONS: CA 125 is an independent prognostic factor of survival and tumor relapse in non-small cell lung cancer. The preoperative serum level of CA 125 antigen is inversely correlated with the outcome figures. The authors suggest that CA 125 be included in any future multifactorial analysis of survival.

Adenocarcinoma↗
PubMed1994

Utility of selective digestive decontamination in mechanically ventilated patients.

OBJECTIVE: To assess selective digestive decontamination for preventing nosocomial pneumonia and mortality in mechanically ventilated patients. DESIGN: Prospective, randomized, placebo-controlled, double-blind study. SETTING: Respiratory intensive care unit of a 1000-bed teaching hospital. PATIENTS: 80 patients receiving mechanical ventilation for more than 72 hours. INTERVENTIONS: Patients received selective digestive decontamination using polymyxin E, tobramycin, and amphotericin B through a nasogastric tube and also topically in the oropharynx; control patients received placebo. All patients received intravenous cefotaxime for 4 days or other systemic antibiotics if required. MEASUREMENTS: Bacteriologic surveillance (three times a week) was done by quantitatively culturing tracheal aspirates, pharyngeal swabs, and gastric juice. The diagnosis of pneumonia was based on quantitative cultures of protected specimen brush samples (> or = 10(3) CFU/mL [colony forming units/mL]) or bronchoalveolar lavage fluid (> or = 10(4) CFU/mL) and autopsy findings. RESULTS: Bronchial, oropharyngeal, and gastric colonization by gram-negative bacilli and Candida species was lower in the selective digestive decontamination group compared with the placebo group. Nonsignificant differences were found in the incidence of nosocomial infections (28% compared with 37%; odds ratio, 0.66; 95% CI, 0.35 to 1.25) and nosocomial pneumonia (18% compared with 24%; odds ratio, 0.7; CI, 0.33 to 1.46) and in the crude mortality rate (31% compared with 27%; odds ratio, 1.21; CI, 0.63 to 2.34) when comparing digestive decontamination with placebo, respectively. CONCLUSIONS: Selective digestive decontamination in our mechanically ventilated patients significantly decreased the colonization rate of gram-negative bacilli and of Candida species but not of Staphylococcus aureus. It did not decrease the incidence of nosocomial pneumonia, mortality, length of stay, or the duration of mechanical ventilation.

Adult↗