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Biomedical subjects

M Alvarez

Publications and source records attributed to M Alvarez.

At least 109 records · Page 6Linked to original sources
PubMed2000

Interobserver variability of the measurement of the mortality probability models (MPM II) in the assessment of severity of illness.

OBJECTIVE: To assess the interobserver variability of the measurement of the MPM II system. DESIGN: Random sample of an inception cohort. SETTING: Fifteen adult medical and surgical intensive care units (ICUs) in Spain. PATIENTS: A 5% random sample (n = 119) of 2332 patients consecutively admitted in the ICU, aged 18 years or older. INTERVENTIONS: Prospective data collection during the stay of the patient in the ICU. Repeated data collection, after the patient's hospital discharge. MEASUREMENTS AND MAIN RESULTS: Demographic information, length-of-stay and vital status at both ICU and hospital discharge, as well as all variables necessary for computing the MPM II system were measured. Interobserver variability for categorical variables was measured computing the kappa index. For interval variables the interobserver variability was assessed by the intraclass correlation coefficient, the paired t-test, and linear regression. In the MPM II0 index, the variables coma, heart rate, systolic blood pressure, chronic renal insufficiency, metastatic neoplasm, acute renal failure, cardiac dysrhythmia and cardiopulmonary resuscitation, showed moderate or low levels of agreement. In the MPM II24 index, the variables coma or deep stupor, PaO2 and prothrombin time showed low or moderate interobserver agreement. Agreement for the MPM II probability of death was high, although the external observer obtained a lower estimation than the hospital observer. CONCLUSIONS: The MPM II severity system showed a high level of stability when used in groups of patients. Nevertheless, the observed variability in some variables means that it should be used with caution for individual patients.

Adult↗
PubMed2000

Prevalence and viral persistence of TT virus in patients on hemodialysis.

The aim of this study was toevaluate the prevalence of TT virus (TTV) in 107 hemodialysis patients and 100 healthy individuals. Sixteen percent of hemodialysis patients and 2% of the control population were TTV positive (P<0.001). Sex, time on dialysis, transfusions, and alanine aminotransferase levels were not related to the presence of TTV DNA. TTV was more frequent in patients 50 to 70 (12/51) years of age and persisted in the serum of six of nine patients 8 months later. TTV was found in peripheral blood mononuclear cells of all patients with chronic infection, and sequence variation was noted in the peripheral blood mononuclear cells of two patients. No relationship between TTV infection and hepatitis was observed. Viral persistence and nonparenteral transmission may be possible in patients on hemodialysis.

Aged↗
PubMed2000

New sources and antifungal activity of sesquiterpene lactones.

In the search for new sources of sesquiterpene lactones, six Centaurea species have been analyzed. The activity against the fungus Cunninghamella echinulata of (+)-cnicin (1) and (+)-salonitenolide (2), isolated from the Centaurea plants, as well as that of (+)-costunolide (3), (-)-dehydrocostuslactone (4), (-)-lychnopholide (5) and (-)-eremantholide C (6), has been evaluated. Compounds 3 and 4 showed noticeable EC50 values, whilst more polar lactones were inactive. These results suggest that a relatively low polarity is one of the molecular requirements for the antifungal activity of sesquiterpene lactones.

Antifungal Agents↗
PubMed2000

Oral iron cutaneous adverse reaction and successful desensitization.

BACKGROUND: The oral administering of iron preparations sometimes produces adverse gastrointestinal effects. In contrast, cutaneous reactions are extremely rare. OBJECTIVE: We report a patient with several episodes of generalized pruritus and erythematous maculopapular eruption after receiving oral compounds of iron and on whom desensitization with oral iron was attempted. METHODS: We studied a female with microcytic anemia due to gynecologic blood loss who presented several episodes of cutaneous eruption after receiving oral compounds of iron. Skin prick-test and two simple-blind, placebo-controlled oral challenges were performed with various iron compounds, and finally desensitization with oral iron was carried out. RESULTS: Skin prick-test and patch-test with iron preparations were negative. Two simple-blind, placebo-controlled oral challenges were performed and the patient began experiencing similar cutaneous symptoms. We started a slow desensitization protocol using increasing doses until the target amount of the drug was tolerated without adverse effects. The chronic administration of oral iron therapy once a day for 9 months sustained the desensitized state and the anemia disappeared. CONCLUSION: We present methods to effectively manage iron supply for a microcytic anemia patient with cutaneous reactions due to oral iron compounds, to avoid repeated transfusions, slow desensitization with oral iron was successfully attempted.

Administration, Oral↗
PubMed2000

Serological prevalence to six leptospiral serovars in cattle in Asturias (Northern Spain).

The prevalence of antibody to six serovars of Leptospira interrogans in cattle in Asturias (Northern Spain) was determined by the microscopic agglutination test (MAT). Using 50% agglutination or lysis at a dilution of 1:10 or more as the criteria for seropositivity, 371 of 3578 (10.36%) animals were found to react with one serovar. The most commonly detected serovars were pomona (5.59%) and grippotyphosa (2.37%), whilst serovar hardjo (0.75%), icterohaemorrhagiae (0.64%), poi (0.64%) and autumnalis (0.36%) were found at lower frequencies.

Agglutination Tests↗
PubMed2000

Preparation, stereochemistry, and cytotoxic activity of the melampolides from Mikania minima.

The semisyntheses of melampolides 1 and 2, previously found in Mikania minima, were carried out in order to confirm their chemical structures and to establish their absolute configurations. Their conformational analyses, performed using molecular mechanics, experimental (1)H NMR coupling constants, and NOE experiments, showed a preferred DU conformer in solution at room temperature. The cytotoxic activities of 1 and 2 against three tumor cell lines were also determined. Conjugated aldehyde 2 showed higher activity than alcohol 1.

Antineoplastic Agents, Phytogenic↗
PubMed2000

Immunohistochemical localisation of rabbit haemorrhagic disease virus VP-60 antigen in early infection of young and adult rabbits.

This study evaluated the time course distribution of rabbit haemorrhagic disease virus (RHDV) structural protein VP60 in tissues from experimentally infected rabbits from three different age groups. Viral VP60 antigen could not be detected in tissue samples from animals under four weeks, and only a few hepatocytes (0.01 to 0.2 per cent) were stained in the 6-week-old animals. A 6-week-old rabbit euthanised at 72 hpi showed VP60-labelling in hepatocytes and macrophages close to areas of inflammation. Viral VP60 antigen was detected as early as 12 hpi in a few hepatocytes (0.03 per cent) from adult animals. Within this age group, the extent of hepatocyte labelling considerably increased at 18 (3.0 per cent), 24 (25.5 per cent), 36 (50 per cent) and 48 (60 per cent) hpi. Extrahepatic viral VP60 antigen was also detected at 36 and 48 hpi in spleen macrophages and lymphocytes from adult rabbits. These findings support the hypothesis that the hepatocyte is the only cell type in the liver able to support RHDV replication almost immediately after viral infection.

Animals↗
PubMed2000

Performance of the Mortality Probability Models in assessing severity of illness during the first week in the intensive care unit.

OBJECTIVE: To extend the Mortality Probability Models (MPM) II severity system to time periods between 4 and 7 days after admission to the intensive care unit (ICU). DESIGN: Prospective inception cohort. SETTING: Fifteen adult medical and surgical ICUs in Spain. PATIENTS: A total of 1,441 patients aged > or =18 yrs consecutively admitted from April 1, 1995 through July 31, 1995. INTERVENTIONS: Prospective data collection during the stay of the patient in the ICU. Data collected included demographic information, length-of-stay and vital status at both ICU and hospital discharge, as well as all variables necessary for computing the MPM II system at admission and during the first 7 days of stay in the ICU MEASUREMENTS AND MAIN RESULTS: Calibration and discrimination of the four existing MPM II models (MPM0, MPM24, MPM48, and MPM72) were assessed in the study database. The MPM II system overestimated the mortality of patients with probabilities of death > or =0.4. The MPM24 model was customized. Models for time periods between 48 hrs and 7 days (MPM48 to MPMd7) were obtained using the same strategy that was used to develop the original MPM48 and the MPM72 models. The variable coefficients of the MPM24 model were kept fixed and the constant terms of the MPM48 to MPMd7 models were estimated by logistic regression. The constant term stabilized after the fourth day of admission and it was similar to the constant term of the MPM72 model. The customized MPM72 performed very well for days 4 to 7 after admission to the ICU. CONCLUSIONS: If the patient's condition stays the same day after day, the probability of dying in the hospital increases until 72 hrs, and then stabilizes. A severity measure that performs well at 72 hrs can be a useful tool for measuring severity at later time periods.

Critical Care↗
PubMed2000

Early heart rate variations during head-up tilt table testing as a predictor of outcome of the test.

Head-up tilt table testing (HUTT) is a useful tool for the diagnosis of unknown origin of syncope. A setback is its duration. This study tries to establish a specific parameter that, according to the heart rate elevation in the test's initial phase, allows a reliable prediction of its outcome. In a prospective study, every patient being under unknown syncope workup was included. A two-phase 20-minute tilt table test was performed. The initial phase was passive, and the second required pharmacological stimulation with isoproterenol. The basal and 5- and 10-minute heart rate values of the passive phase were measured and compared within the group and against negative tests. During a 1-year period, 115 HUTT were performed: 88 were positive and 27 negative. The negative HUTT patients had an increase in HR of 5.05 (+/- 13.5) beats/min at 5 minutes, and 5.79 (+/- 12.9) beats/min at 10 minutes (P = 0.2). Those with a positive HUTT had an increase of 9.05 (+/- 14.5) beats/min at 5 minutes, and of 10 (+/- 13.4) beats/min at 10 minutes (P < 0.001). There were no significant changes in HR when comparing positive to negative HUTT. There is no specific number that allows predication of outcome early in HUTT. Within the group, variations are important. Only a group tendency can be established, which strongly correlates with the results obtained during the test.

Adult↗
PubMed2000

Human Dengue antibodies against structural and nonstructural proteins.

Antibodies against dengue virus type 2 and 4 proteins in acute-phase sera of 10 primary and 10 secondary dengue fever and dengue hemorrhagic fever patients were studied by Western blotting. In the first group the immune response was barely detectable, while in the second group more proteins were detected, with a very strong reaction. Anti-NS1 and -NS3 antibodies were detected mainly in secondary cases. Anti-E, -NS3, and -NS5 antibodies were detected in a high number of cases. The possibility of implementing early diagnostic assays for antigen detection is suggested.

Animals↗
PubMed2000

Comparison of rapid centrifugation assay with conventional tissue culture method for isolation of dengue 2 virus in C6/36-HT cells.

A rapid centrifugation assay was compared with conventional tube cell culture for dengue virus isolation in both sera and autopsy samples from dengue and dengue hemorrhagic fever/dengue shock syndrome fatal cases. The rapid centrifugation assay allowed isolation of virus from 16.6% more samples than the conventional method, and it shortened the time for dengue virus detection. Finally, it allowed the isolation of dengue 2 virus in 42.8% of tissue samples from five fatal cases. Our results suggest that the rapid centrifugation assay may be useful for detection of dengue virus in clinical specimens.

Aedes↗
PubMed2000

Effect of olive oil on early and late events of colon carcinogenesis in rats: modulation of arachidonic acid metabolism and local prostaglandin E(2) synthesis.

BACKGROUND: Animal model studies have shown that the colon tumour promoting effect of dietary fat depends not only on the amount but on its fatty acid composition. With respect to this, the effect of n9 fatty acids, present in olive oil, on colon carcinogenesis has been scarcely investigated. AIMS: To assess the effect of an n9 fat diet on precancer events, carcinoma development, and changes in mucosal fatty acid composition and prostaglandin (PG)E(2) formation in male Sprague-Dawley rats with azoxymethane induced colon cancer. METHODS: Rats were divided into three groups to receive isocaloric diets (5% of the energy as fat) rich in n9, n3, or n6 fat, and were administered azoxymethane subcutaneously once a week for 11 weeks at a dose rate of 7.4 mg/kg body weight. Vehicle treated groups received an equal volume of normal saline. Groups of animals were colectomised at weeks 12 and 19 after the first dose of azoxymethane or saline. Mucosal fatty acids were assessed at 12 and 19 weeks. Aberrant crypt foci and the in vivo intracolonic release of PGE(2) were assessed at week 12, and tumour formation at week 19. RESULTS: Rats on the n6 diet were found to have colonic aberrant crypt foci and adenocarcinomas more often than those consuming either the n9 or n3 diet. There were no differences between the rats on the n9 and n3 diets. On the other hand, administration of both n9 and n3 diets was associated with a decrease in mucosal arachidonate concentrations as compared with the n6 diet. Carcinogen treatment induced an appreciable increase in PGE(2) formation in rats fed the n6 diet, but not in those fed the n3 and n9 diets. CONCLUSIONS: Dietary olive oil prevented the development of aberrant crypt foci and colon carcinomas in rats, suggesting that olive oil may have chemopreventive activity against colon carcinogenesis. These effects may be partly due to modulation of arachidonic acid metabolism and local PGE(2) synthesis.

Adenocarcinoma↗
PubMed2000

Human chorionic gonadotropin and intravaginal natural progesterone are equally effective for luteal phase support in IVF.

This prospective randomized study compared human chorionic gonadotropin (hCG) and micronized transvaginal progesterone for luteal support in 310 in vitro fertilization (IVF) patients treated with leuprolide acetate and gonadotropins in a long protocol, and showing normal ovarian response. Both treatment groups were homogeneous for age, BMI, stimulation treatment and ovarian response. Pregnancy rates per embryo transfer were not significantly different (33.1% for the hCG group versus 38.7% for the progesterone group). For IVF patients with a normal response to stimulation under pituitary suppression, the use of hCG or progesterone for luteal support does not seem to have any effect on pregnancy rate. The choice of luteal treatment must balance medical hazard and patient convenience, as both therapeutic regimens seem equally effective.

Administration, Intravaginal↗
PubMed2000

Long-term effects of a nationwide control program on the seropositivity for Trypanosoma cruzi infection in young men from Argentina.

Unselected nationwide cohorts of Argentine men 18 years of age summoned for military service were tested for antibodies to Trypanosoma cruzi each year from 1981 to 1993. After an initial screening using indirect hemagglutination test, the positive sera were retested by titrated indirect hemagglutination and immunofluorescence antibody tests at 39 laboratories or at the national reference center in Buenos Aires. Nearly 1.8 million men were examined for T. cruzi antibodies using the same standardized procedures under a quality assurance program. The prevalence of seropositivity for T. cruzi decreased significantly from 5.8% in 1981 to 1.9% in 1993, but the decrease was not homogeneous among provinces within each region or constant over time. Prior to the nationwide control campaign initiated in 1961-1962, 15 provinces had high (> 20%) percentages of houses with domiciliary infestation by Triatoma infestans bugs, which decreased to nine provinces in 1982, and four provinces in 1992. The observed decrease in the prevalence of seropositivity for T. cruzi may be mostly attributed to the spraying with insecticides to eliminate the domiciliary populations of Triatoma infestans. The lack of a sustainable triatomine surveillance program set a limit to the decrease of seropositivity rates and prompted a revised strategy based on community participation.

Adolescent↗
PubMed2000

[Nocardia asteroides infection in a patient with systemic lupus erythematosus].

Nocardia asteroides infection are unusually observed in systemic Lupus erithematous (SLE) patients. They are generally associated to steroidal and immunosuppressive therapy. We report a 24 years old female with SLE diagnosed in 1994 who developed a severe preeclampsia in her first pregnancy requiring emergency caesarean section. Post partum acute renal failure and type IV lupus nephropathy were treated with hemodialysis, methylprednisolone, cyclophosphamide and prednisone. Three months later, while she was receiving the fourth cyclophosphamide dose, she presented with a pleuro pneumonia and occipital abscess, both caused by Nocardia asteroides. She was treated with cotrimoxazole + cefixime and pleural decortication was required. Five months later, she developed Meningitis caused by Nocardia asteroides and hydrocephalus. She was treated with ceftriaxone, vancomycin, cotrimoxazole and ventricular shunting procedure. Two months later, a retroperitoneal abscess was diagnosed and surgically drained but the patient died, due to a methicillin-resistant Staphylococcus aureus septicemia.

Adult↗
PubMed2000

Detection of HCV and GBV-CHGV RNA in peripheral blood mononuclear cells of patients with chronic type C hepatitis.

Hepatitis C virus (HCV) and hepatitis G virus (HGV) viraemia were investigated by RT-PCR protocols in peripheral blood mononuclear cells (PBMC) of 22 patients with chronic type C hepatitis. Samplings were at basal and 4-8 months after a 12 month period of treatment with interferon-alpha. A plus strand of HCV in PBMC was detected in 8 of 21 patients (38%) (p <0.05; chi2 test) with a lack of response to therapy; a minus strand was detected in 10% of chronic type C hepatitis and 25% of the patients harboured HCV RNA in PBMC. The association with a response was nearly significant (p <0.1; chi2 test). GBV-C/HGV RNA was detected in the serum of 9 of 21 (43%) patients and in PBMC of 20% of the patients viraemic. Genomic sequences of GBVC/HGV in PBMC were found, but further investigation is needed to assess the findings reported for HCV.

Flaviviridae↗