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Biomedical subjects

M Torres

Publications and source records attributed to M Torres.

At least 361 records · Page 20Linked to original sources
PubMedDate not supplied

Cleavage of DNA by electrochemically activated MnIII and FeIII complexes of meso-tetrakis (N-methyl-4-pyridiniumyl)porphine.

Electrochemical methods were used to activate MnIII and FeIII complexes of meso-tetrakis(N-methyl-4-pyridiniumyl)porphine (H2TMPyP) to cause cleavage of pBR322 DNA and to study their interaction with sonicated calf thymus DNA. Electrochemical reduction of MnIIITMPyP and FeIIITMPyP (at low concentrations) in the presence of O2 was required to activate these complexes. However, FeIIITMPyP at 1 x 10(-6) M produced DNA strand breakage without being electrochemically reduced. At low concentrations, FeIITMPyP was more efficient at cleaving DNA than MnIITMPyP. Reduction of O2 at a platinum electrode also produced some cleavage but to a much smaller extent. The oxidized form of MnIIITMPyP (charge 5+) has higher affinity for sonicated calf thymus (CT) DNA than the reduced form (charge 4+), as determined by the negative shift in E degrees' for the voltammetric wave in the presence of DNA. Both forms of FeIIITMPyP (charge 4+) interact with DNA to about the same extent. Differential pulse voltammetry was used to determine binding constants (K) and binding-site sizes (s) of the interaction of these metalloporphyrins with sonicated CT DNA. The data were analyzed assuming both mobile and static equilibria. MnIIITMPyP binds to DNA (5 mM Tris, 50 mM NaCl, pH 7) with K = 5 (+/- 2) x 10(6) M-1, s = 3 bp (mobile) or K = 3.6 (+/- 0.3) x 10(6) M-1, s = 4 bp (static). FeIIITMPyP at that ionic strength caused DNA precipitation. At higher ionic strength (0.1 M Tris, 0.1 M NaCl, pH 7), FeIIITMPyP associates to DNA with K = 4.4 (+/- 0.2) x 10(4) M-1, s = 5 bp (mobile) or K = 1.9 (+/- 0.1) x 10(4) M-1, s = 6 bp (static).

DNA↗
PubMedDate not supplied

Sertraline for the prevention of relapse in detoxicated alcohol dependent patients with a comorbid depressive disorder: a randomized controlled trial.

AIMS: We performed a double-blind, placebo-controlled randomized trial of sertraline in recently detoxified alcohol-dependent patients with current depressive symptoms. The objectives of the study were to evaluate the efficacy of sertraline at achieving stable abstinence, at ameliorating depressive symptoms and at improving quality of life in these patients. METHODS: The study included 83 patients, who received either sertraline (50-150 mg/day) or placebo for 24 weeks. The primary outcome criteria were the rate of relapse into alcohol consumption and the rate of response on the Montgomery and Asberg Depression Rating Scale (MADRS). RESULTS: At the end of the treatment period, relapse rates were 23.1% in the placebo group and 31.8% in the sertraline group. Responder rates for depression were 38.5% for the placebo group and 44.2% for the sertraline group. There was no significant difference between treatment groups with either variable. However, when patients were stratified into severe (MADRS score >or=26) and moderate (MADRS score <26) depression at inclusion, a significant treatment benefit with sertraline was observed in the former group. Quality of life, determined by the SF-36, improved in both groups, with more benefit observed for the sertraline group on mental health items. Sertraline was well tolerated, and the incidence of adverse events was similar in the two treatment groups. CONCLUSIONS: The explanation for the overall good outcome in both treatment groups and for the inability to demonstrate a clear treatment effect may reside in the clinical features of the patients included.

Adult↗
PubMedDate not supplied

Therapeutic compliance among asthma patients in an allergy clinic: third evaluation (SEGARIA Project).

OBJECTIVES: To perform a third evaluation of therapeutic compliance in asthma patients managed in our department by using identical methodology to that employed in two prior evaluations (1995 and 1993). To study the possible association between correct inhalation technique and the patient's degree of knowledge about asthma. MATERIAL AND METHODS: A random sample with a fixed rate was obtained, comprising 54 adult patients with asthma (aged more than 18 years old) managed in our department in an outpatient regime. Patients who reported that they habitually failed to comply with the treatment duration, the number of dosage times per day, or the dose at each specific dosage time were classified as noncompliers with the medication in question. The study was performed during October and November, 2003. First visits were excluded. The same categories of medications and procedures as those employed in the 1993 and 1995 studies were used. RESULTS: Of the 54 patients studied, 19% revealed some type of pharmacological noncompliance. The overall percentage of incorrectly used medication was 8%. Among noncompliers, clinical course was poor in 44% and additional visits to specialists or the emergency room were required in 45%. Incorrect use was most frequent with the turbuhaler (32.1%), and faulty technique was also most common with this device (67.9%). CONCLUSIONS: In this evaluation, overall therapeutic compliance was clearly better than that in 1995 (81% compared with 54%), indicating a positive tendency over time. These results were more positive than those reported in the scientific literature on therapeutic compliance. Nevertheless, correct inhalation technique was markedly less frequent than in our previous studies. The most incorrectly used pharmacological groups continue to be the controller medications. A nonsignificant tendency among noncompliers to require more additional visits and to have worse clinical course and less knowledge about their disease than compliers was maintained. This type of evaluation continues to be useful in the clinical monitoring of therapeutic complicance in daily clinical practice.

Administration, Inhalation↗
PubMedDate not supplied

Medical audit on asthma in an emergency department.

BACKGROUND: To determine the management of acute bronchial asthma in an adult emergency department. METHODS: A retrospective medical audit of 46 consecutive adult patients with acute asthma exacerbations was performed. We collected information from 48 episodes of acute asthma over a 5-month period. Using classical audit methodology, four indicators were examined: severity evaluation, diagnostic tests, specific treatment, and discharge treatment plans. RESULTS: The least recorded severity indicators were respiratory rate (27 %), heart rate (50 %) and peak expiratory flow (20 %). Heart and respiratory auscultation were recorded in all patients and oxygen saturation was recorded in 93 %. Laboratory blood test and chest radiograph were performed in all patients. Arterial blood gas was tested in 57 %, electrocardiography in 17 %, and coagulation in 39 %. No treatment was provided in 12 % of patients. Bronchodilator medications were administered in all treated patients and oxygen was prescribed in 60 %. Systemic corticosteroids (methylprednisolone or hydrocortisone) were administered in 80 % of treated patients. Seventeen percent of patients were discharged from hospital with no change to their usual treatment. CONCLUSIONS: The following weak points were identified: 1) Severity assessment is inadequate, 2) use of diagnostic tests is excessive, 3) patients discharged to home with no treatment plan. Opportunities for improvement consisted of: 1) greater availability of peak expiratory flow meters, 2) individualized use of diagnostic tests, and 3) management protocols.

Acute Disease↗
PubMedDate not supplied

Progressive external ophthalmoplegia: a paraneoplastic manifestation of lymphoma.

PURPOSE: Paraneoplastic neurological syndromes are well-known sequelae of some malignancies. To our knowledge, a syndrome mimicking progressive external ophthalmoplegia had never been reported preceding the diagnosis of a lymphoma. CASE REPORT: A 63-year-old man developed progressive external ophthalmoplegia, without any other neurological symptoms, as the initial manifestation of a follicular lymphoma grade III. The ophthalmoplegia resolved after two cycles of combination chemotherapy. CONCLUSIONS: The ophthalmologist, when confronted with a progressive external ophthalmoplegia, should consider a neurological paraneoplastic syndrome associated with a tumor as a possible diagnosis.

Aged↗
PubMedDate not supplied

Immunoscintigraphy with 131I or 111In labelled OC 125 F(ab')2 fragments in patients with ovarian carcinoma.

To evaluate the clinical usefulness of immunoscintigraphy with OC 125 in ovarian carcinoma, we studied 25 patients suspected of having ovarian carcinoma or in follow-up after surgery. Fourteen patients were studied with 131I-OC 125 F(ab')2 and 11 with 111In-OC 125 F(ab')2. No differences were observed with the use of either radionuclide. Global diagnostic indexes obtained were S = 100%, Sp = 44,5% and A = 81%. The low specificity obtained was remarkable: 5 false positive results in two uterine myomas, one abscess, one follicular cyst and one granulation tissue scar. On the other hand, all lesions of ovarian carcinoma were detected. Analysis of the evolution of tumor/background (T/B) uptake ratios from the first to the second day of exploration revealed a tendency for the ratio to diminish significantly (greater than 15%) in false positive cases with the exception of the abscess while this did not happen in true positive cases, with the exception of a regional recurrence. Analysis of T/B ratio variations could contribute towards elevating the test's specificity.

Antibodies, Monoclonal↗
PubMedDate not supplied

CA 549 and SP2 in postoperative breast cancer patients. Comparison with CA 15.3, CEA and TPA.

The levels of CA 549 and SP2 were measured in 430 subjects: 100 healthy blood donors, 130 patients with benign diseases and 200 postoperative breast cancer patients. In the latter group, the serum levels of CA 15.3, CEA and TPA were also measured. The Kolmogorov-Smirnov, Mann Whitney and McNemar tests were used for statistical analysis. The upper normal limits were established on the basis of the values obtained in the healthy blood donors group, the benign diseases group and R.O.C. analysis of the breast cancer group. They were: CA 549 = 13 U/ml, SP2 = 14 U/ml, CA 15.3 = 35 U/ml, CEA = 5 ng/ml and TPA = 110 U/ml. The sensitivity, specificity and accuracy in the breast cancer group were, respectively: CA 549 = 78.1%, 97.1% and 88%; SP2 = 21.9%, 90.4% and 57.5%; CEA = 66.7%, 95.2% and 81.5%; CA 15.3% = 80.2%, 98.1% and 89.5%, and TPA = 73.9%, 78.8% and 76.5%. Statistical analysis showed significant differences only between CA 15.3, the marker which gave the best results, and SP2 (p < 0.001). There was no significant differences with the association of two or three tumor markers.

Antigens, Tumor-Associated, Carbohydrate↗
PubMedDate not supplied

Haematophagy and cleptohaematophagy of clerada apicicornis (Hemiptera: lygaeidae), a potential biological control agent of rhodnius prolixus (Hemiptera: reduviidae).

Because of its ability to prey on Triatominae in rural houses, Clerada apicicornis has been suggested as a potential biological control agent of Rhodnius prolixus. It has also been suggested as a potential vector of mammalian trypanosomes such as Trypanosoma cruzi, because of its ability to take blood directly from mammals. To help resolve these conflicting ideas, we assessed the haematophagic behaviour of C. apicicornis by carrying out feeding trials on laboratory animals. Cleptohaematophagic behaviour was also assessed by allowing C. apicicornis to feed on R. prolixus previously engorged with avian blood. The low proportion of blood meals taken directly from laboratory animals indicates a facultative haematophagy in this species, whereas a greater proportion of nymphs and adults were able to obtain vertebrate blood by predation on engorged R. prolixus. The results suggest that C. apicicornis is unlikely to be effective as a biological control agent, but is also unlikely to have a significant role in the transmission of vertebrate pathogens.

Animals↗
PubMedDate not supplied

Effective career ladders.

Motivation, quality improvement, productivity enhancement. These are just some of the benefits of an effective career ladder program. The key term here is effective. It is easy for laboratory personnel to stagnate professionally if they do not have a career ladder program, but it is even easier for them to become frustrated--even cynical--over a program that fails to live up to its expectations to encourage, support, and reward professional advancement. If you have been looking form some ideas to get your own career ladder program off the ground, the following responses from your colleagues may help as CLMR asks: What makes your career ladder program effective?

Career Mobility↗
PubMedDate not supplied

[Quantification of T CD4+ lymphocytes and viral RNA in patients with HIV/AIDS].

Quantification of CD4+ T lymphocytes and viral RNA in patients with HIV/AIDS. Levels of progression markers (viral load and CD4+ T lymphocytes) in 410 patients with HIV/AIDS that were in different clinical stages of the disease and under different therapeutic schemes were quantified. The objective was to determine the correlation between values of progression markers and clinical stage of the patients. Commercial methodologies for the quantification of lymphocytes, subpopulations and circulating viral RNA were used. Results indicate that there was a correlation between low CD4+ values and high viral load in patients with antiretroviral treatment but not in patients without treatment. Furthermore, analysis of 1,208 samples processed during 1999 showed that 46% of the patients had less than 200 CD4+ T lymphocytes/mL blood and more than 500 copies of circulating viral RNA. Implications of these results in public health in Mexico are discussed.

CD4 Lymphocyte Count↗
PubMedDate not supplied

[Adverse effects of cotrimoxazole in Spanish patients with AIDS and pneumonia caused by Pneumocystis carinii].

We retrospectively analyze the untoward effects due to cotrimoxazole (CMX) when this drug was used as initial therapy in 37 Spanish AIDS patients with Pneumocystis carinii pneumonia (PCP). A total of 46% of patients developed an adverse reaction, that was considered severe in 24.3% of cases, and prompted to stop CMX therapy in 10.8% of patients. The most frequent untoward effects were low white blood cells count (29.7%), skin rash (16.2%) and low platelet count (13.5%). The overall compliance and absence of undesirable effects to CMX seen in our patients, together with the well established clinical efficacy of this drug, allow us to recommend the use of CMX as initial therapy for Spanish AIDS patients with PCP.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

The effect of adjunctive arteriovenous fistula on prosthetic graft patency: a controlled study in a canine model.

Bilateral 6 mm PTFE grafts were placed from the external iliac artery to the femoral artery with ligation of the intervening segment of the iliofemoral artery in 14 dogs. An arteriovenous fistula was constructed at the distal anastomosis on one randomly selected side in each animal while the contralateral graft served as a control. Graft follow-up ranged between 8 and 12 months in all animals. Serial arteriography was performed to confirm graft and fistula patency and demonstrated persistence of antegrade flow into the arterial tree distal to all patent bypasses. Femoral intraarterial pressures distal to patent grafts were identical on both sides in each animal throughout the study. Cumulative life-table patency rates showed higher patency for the arteriovenous fistula bypasses than the control grafts at all time intervals: 71% vs. 57% at 3 months, 48% vs. 25% at 6 months, and 40% vs. 22% at 12 months, respectively. This is the first controlled study that provides experimental evidence suggesting that these bypasses may produce increased patency of prosthetic arterial grafts and lends support to their use in a clinical, prospective, randomized study.

Animals↗