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Biomedical subjects

A Otero

Publications and source records attributed to A Otero.

At least 19 recordsLinked to original sources
PubMed1992

[New trends in medical education. Evaluation of placements in health centers].

Whether to use just hospitals or a wider range of health resources is one of the debating-points in the updating of undergraduate medical training programmes. The Faculty of Medicine in the Autonomous University of Madrid integrated obligatory Primary Care placements for students in the last year of their course, into its syllabus as from 1988/89. This programme and the students' own assessment of it was studied by means of a systematic, voluntary and anonymous survey, which covered various aspects of their assignments to Primary Care teams. 93% (473) replied. Every student took part in the clinical activities, both on demand and as programmed. 76% went on home visits along with their tutors. 88% considered that their placement was active. The overall evaluation of the placement by the students is 8 out of 10. Half believe that a month is too short a period and suggest that more time is offered as an optional placement. 98% consider that the Centre in which they were placed was sufficiently or very capable of teaching at the undergraduate level. Placing medical students in Primary Care teams is an essential part of today's medical teaching and is feasible within the present health system. The relationship between the University and the general physicians who act as tutors is seen as the main obstacle that needs to be overcome.

Community Health Centers↗
PubMed1992

Distinct mechanisms of inhibition of purified cardiac sarcolemma Ca(2+)-ATPase by two calmodulin antagonists.

The effects of calmidazolium and compound 48/80 were studied in four different states of activation of the purified Ca(2+)-ATPase from cardiac sarcolemma: "basal" or unactivated, activated by calmodulin, activated by phosphatidylserine, and activated by controlled trypsinization. When assayed in the presence of phosphatidylcholine as the sole phospholipid (basal state), the purified enzyme was resistant to inhibition by calmidazolium (0.1 to 3 microM). In the same range, calmidazolium inhibited the enzyme activated by controlled proteolysis as well as the calmodulin-activated enzyme regardless of the calmodulin concentration. The phosphatidylserine-activated enzyme was inhibited at higher calmidazolium concentrations due to non-specific trapping of the inhibitor by the excess of phospholipid. Addition of calmidazolium did not modify the K0.5 for calcium activation of ATP hydrolysis by the enzyme. The inhibition by calmidazolium was counteracted by Pi. Compound 48/80 also had no effect on the enzyme when only phosphatidylcholine was present and, like calmidazolium, it inhibited the calmodulin-activated enzyme and the phosphatidylserine-activated enzyme. The apparent Ki for inhibition by compound 48/80 was dependent on the calmodulin concentration. However, the enzyme activated by controlled trypsinization was insensitive to compound 48/80. Binding of 48/80 to the enzyme in the presence of phosphatidylserine or calmodulin reversed the increased affinity for Ca2+ caused by these activators.

Adenosine Triphosphate↗
PubMed1992

Effect of culture age, pre-incubation at low temperature and pH on the thermal resistance of Aeromonas hydrophila.

The thermal resistance of Aeromonas hydrophila strain NCTC 8049 was determined within the range 48 degrees-65 degrees C with a thermoresistometer TR-SC and McIlvaine buffer. The effects of culture age, pre-incubation at 7 degrees C and the pH of the heating menstruum were evaluated. The pattern of thermal death was dependent on culture age. Cells heated in the late logarithmic growth phase (15 h at 30 degrees C) were twice as resistant as those in the early stage (5 h at 30 degrees C), and the maximum D-value was obtained after 72 h incubation (5.5 total increase). The age of the cells did not affect z-values significantly. The heat resistance of cells incubated for 48 h at 30 degrees C increased (twice) after holding at 7 degrees C for 72 h. Pre-incubation at low temperature of older cultures (72 h, 30 degrees C) did not influence their D-values. Maximum heat resistance was found at pH 6.0 and minimal at pH 4.0. Decreasing the pH from 6.0 to 4.0 reduced D-values by a factor of 5. Although the strain studied was heat-sensitive (D55 degrees C = 0.17 min; z = 5.11 degrees C), survivor curves of cultures older than 50 h showed a significant tailing. Organisms surviving in the tails were only slightly more resistant than were the original population.

Aeromonas hydrophila↗
PubMed1992

Species of Pseudomonas obtained at 7 degrees C and 30 degrees C during aerobic storage of lamb carcasses.

A total of 268 strains of Pseudomonas isolated during storage life of lamb carcasses was identified to species level. One-hundred and thirteen strains obtained at 30 degrees C were Ps. fragi (51), Ps. lundensis (17), Ps. fluorescens biovars I (10), III (9) and VI (1), Ps. putida biovar A (8 strains) and unidentified (17 strains). Species and biovars isolated at 7 degrees C (155) were Ps. fragi (101), Ps. lundensis (32), Ps. fluorescens biovar I (6), Ps. putida biovar A (8) and unidentified (8). Numerical analysis (82% SSM, UPGMA) of 'psychrotrophic' and 'mesophilic' strains resulted in the formation of nine and eight clusters respectively. The dendrograms obtained exhibited similar structures. Most of the strains of Ps. lundensis and Ps. fragi clustered together. Strains of this latter species also joined the type strain of Ps. testosteroni and appeared included with phenons containing the Ps. putida strains. There were clusters made up exclusively of strains assigned to one biovar or group (Ps. fluorescens biovars I and II and unidentified). A high level of similarity was observed between clusters of Ps. fluorescens biovar I and those containing the Ps. fragi-Ps. lundensis complex (> 74% SSM) and Ps. lundensis (> 80%). The recovery of pseudomonads seemed to be affected by the sampling day.

Aerobiosis↗
PubMed1992

Numerical taxonomy of gram-negative, nonmotile, nonfermentative bacteria isolated during chilled storage of lamb carcasses.

A numerical taxonomic study using 75 characters was performed with 132 strains of gram-negative, nonmotile, nonfermentative bacteria selected on the basis of lack of motility and Gram reaction among 1,200 cultures isolated during aerobic storage of lamb carcasses. At the 80% similarity level (SSM), eight clusters were formed. Strains in clusters 1 to 6 could be identified as members of the family Moraxellaceae and, more specifically, as members of the Psychrobacter-[Moraxella] phenylpyruvica subgroup. Of these strains, clusters 1 and 2 (88 strains) were identified as [Moraxella] phenylpyruvica and cluster 3 (15 strains) was identified as Psychrobacter immobilis. Clusters 4, 5, and 6 were not identifiable with any species. Clusters 7 and 8 consisted of 14 strains considered nonmotile variants of Pseudomonas fragi. The highest separation indices corresponded to acid production from certain carbohydrates (melibiose, L-arabinose, and cellobiose). Although strains of Psychrobacter-Moraxella clusters were relatively frequently identified at the completion of slaughter, very few cultures were detected on spoiled carcasses. It appears, therefore, that this group of organisms has only low spoilage potential.

Animals↗
PubMed1992

[Masked Philadelphia chromosome: diagnostic implications in a case of chronic myeloid leukemia presenting in blast crisis].

We present a female patient with acute non-lymphoblastic leukemia (ANLL) and with haematologic features suggestive of its evolution from chronic myeloid leukaemia (CML), in which a bone marrow karyotype showing a "masked" Philadelphia (Ph) chromosome due to a variant translocation of complex type t(9;9;22)(q32;q34;q11) was found. We comment the peculiarities of this special Ph chromosome as well as the differential diagnostic problems between ANLL Ph(+) and CML with onset in blastic crisis.

Aged↗
PubMed1992

[Design and validation of a questionnaire for screening of venous insufficiency of the lower limbs].

OBJECTIVE: To carry out a questionnaire type test for screening of Chronic Venous Insufficiency (CVI) of lower limbs (LL) to be applied to clinical assistance. DESIGN: Observational type epidemiological study and validation of a test. LOCATION: Fuencarral Health Centre (Madrid). PATIENTS: 100 patients with venous alterations of the lower limbs (cases) and 100 without alterations (control group) selected from the register of the Centre. The inclusion criteria was the presence of truncular varicose veins and/or valvular insufficiency detected by ultra-sound (Doppler). MEASUREMENTS AND MAIN RESULTS: 20 variables were studied possibly associated with the disease and which could be collected by means of a questionnaire. From the epidemiological study, 13 simple questions with a YES/NO answer were chosen for the questionnaire, which collected information on the different variables selected. The maximum number of points of the test was 30. The value of each question was based on the strength of association (ODDS Ratio) and on the degree of reliability of the answers. The sensitivity and specificity of the test taking 14 points as the cutting point, was 82% in both cases. The ROC curve is indicated. CONCLUSIONS: Owing to the high prevalence of CVI of LL and to the possibilities of preventive measures if an early diagnosis is carried out, this questionnaire type test is considered useful among people attending the Health Centre and to be able to select those who require a more detailed and expensive diagnosis examination.

Adolescent↗
PubMed1991

Cytochrome c oxidase subunit II mRNA levels during T-lymphocyte proliferation and liver regeneration.

We studied here the variations in the mRNA levels of the mitochondrially-encoded subunit II of cytochrome c oxidase (COII) during the proliferation of thymocytes, splenic T-cells and hepatocytes. The COII mRNA levels increased during thymocyte proliferation and decreased when they were growth arrested. However, its levels remained nearly constant during splenic T-cell proliferation and liver regeneration after partial hepatectomy. The different pattern of COII gene expression in the cellular systems analyzed suggests that an increment in the oxidative metabolism could not always be necessary during cell proliferation.

Animals↗
PubMed1991

Expression of the rat prothymosin alpha gene during T-lymphocyte proliferation and liver regeneration.

Prothymosin alpha (ProT alpha) is a widely distributed acidic protein whose function has been related to cell proliferation. We have analyzed the expression of the rat ProT alpha gene in several proliferative systems: concanavalin A (ConA)/interleukin-2-stimulated thymocytes, ConA-stimulated splenic T-lymphocytes, and hepatocytes proliferating during liver regeneration. In these systems, ProT alpha mRNA was detected in all stages of the cell cycle, with maximal increments (2-4-fold) at the beginning of the S phase. By contrast, the mRNAs for proliferating cell nuclear antigen/cyclin and histone H3, two cell-cycle-regulated proteins, were hardly detected in resting cells but increased notably at the G1/S boundary and in the S phase, respectively. Treatment of T-cells with the calcium ionophore A23187 increased ProT alpha mRNA levels 2.5-fold, whereas phorbol 12-myristate 13-acetate, a protein kinase C activator, had no effect on ProT alpha gene expression. Incubation of ConA-stimulated T-cells with hydroxyurea, a DNA synthesis inhibitor, did not decrease the levels of ProT alpha mRNA, indicating that its expression is independent of DNA synthesis. These findings suggest that ProT alpha is required throughout all the stages of the cell cycle, resembling a constitutively expressed gene rather than one strictly involved in cell proliferation.

Animals↗
PubMed1991

The binding of anionic and nonionic surfactants to collagen through the hydrophobic effect.

The adsorption of nonionic surfactants on hide powder previously treated with anionic surfactants has been studied. The adsorption of nonionic surfactants takes place through hydrophobic interactions. A mechanism has been proposed for this interaction, assuming that the nonionic surfactant has been fixed by means of secondary adsorption (hydrophobic interaction) after the primary adsorption of the anionic surfactant (ionic and hydrophobic interaction) which makes it possible.

Adsorption↗
PubMed1991

A fatal case of parenteral paraquat poisoning.

The chief clinical and analytical aspects of the suicide of a 21-year-old male with psychiatric problems by parenteral administration of a 200 g/l aqueous solution of paraquat are described. Paraquat levels were determined in plasma, urine, kidney, liver and lung after autopsy. Tissue damage was studied by electron microscopy. The death ensued from pulmonary dysfunction 15 days after hospital admission.

Adult↗
PubMed1990

Production of staphylococcal enterotoxins C1 and C2 and thermonuclease throughout the growth cycle.

Synthesis of enterotoxins C1 and C2 and thermonuclease throughout the growth cycle was investigated with Staphylococcus aureus type strains FRI137 and FRI361 and S. aureus isolates M5 (C1) and L2 (C2) of animal origin. Both enterotoxins were produced during the exponential growth phase or at the beginning of the stationary phase. The minimal incubation time (7 to 12 h) and the lowest population (10(7) to 2 x 10(9) CFU/ml) associated with detectable enterotoxin (1 to 6.5 ng/ml) were related to the total amount of toxin produced after 24 h. Thermonuclease was detected in all samples whenever enterotoxins were detected. Furthermore, strain FRI137 produced thermonuclease earlier and at lower cell populations than it did enterotoxin C1. Patterns of enterotoxin and thermonuclease synthesis did not correlate. The concentration of toxins increased throughout the growth cycle, while the concentration of thermonuclease remained constant during the last hours of the growth cycle.

Animals↗
PubMed1990

Duplex Doppler and spectral flow analysis of racial differences in cerebrovascular atherosclerosis.

We compared carotid artery disease in 99 black and 106 white patients using duplex ultrasonography (B-mode imaging and Doppler spectral analysis). Blacks had significantly less stenosis of the extracranial internal carotid artery than whites. Among the risk factors investigated, hypertension alone, ischemic heart disease, diabetes mellitus, and smoking failed to explain the racial difference. Although carotid stenosis of greater than or equal to 40% correlated significantly with age in both races (p = 0.001 in whites and p = 0.005 in blacks), blacks had significantly less carotid stenosis of any degree even when age was taken into account. Multivariate analysis showed that race is a significant and independent risk factor for carotid stenosis (p less than 0.0001). Hypertension interacting with race was also significant. Our results require verification in population-based studies. Carotid duplex ultrasonography offers a noninvasive method for carrying out such studies.

Age Factors↗
PubMed1990

Biovars of coagulase-positive staphylococci isolated from bovine mastitic milk.

Fifty strains of coagulase-positive staphylococci associated with bovine mastitis were biotyped. Of them, 20 were identified as biovar C (cattle & sheep), 17 as biovar B (poultry & swine), 2 as biovar D (hares) and 1 as biovar F (pigeon & fox). Of the remaining strains, 2 were closely related to human biovar A, 2 failed one property to be classified as biovar B, 3 shared properties of biovars B and D and 3 could not be identified. Bovine strains belonging to biovar C formed an heterogeneous group showing differences in crystal violet growth type and production of alpha haemolysin. Only strains associated with biovar A were Tween 80 positive. The highest incidence of lytic reactions amongst all biovars was with phages 42 E (III) and 102 (IV). Antibiotic resistance was most frequently found in biovar C (65%). The 2 strains in biovar D, one classed as biovar C and one as intermediate, were enterotoxigenic (C or D toxins).

Animals↗