Seismic cycles, size of the largest events, and the avalanche size distribution in a model of seismicity.

We address several questions on the behavior of a numerical model recently introduced to study seismic phenomena, which includes relaxation in the plates as a key ingredient. First, we make an analysis of the scaling of the largest events with system size and show that, when parameters are appropriately interpreted, the typical size of the largest events scale as the system size, without the necessity to tune any parameter. Second, we show that the temporal activity in the model is inherently nonstationary and obtain from here justification and support for the concept of a "seismic cycle" in the temporal evolution of seismic activity. Finally, we ask for the reasons that make the model display a realistic value of the decaying exponent b in the Gutenberg-Richter law for the avalanche size distribution. We explain why relaxation induces a systematic increase in b from its value b≃0.4 observed in the absence of relaxation. However, we have not been able to justify the actual robustness of the model in displaying a consistent b value around the experimentally observed value b≃1.

[Improvement of fecal incontinence with silicone implants in patients with internal anal sphincter injury: First report in North America]. / Mejoría de la incontinencia fecal con implantes de silicón en pacientes con lesiones del esfínter anal interno: primer informe en Norteamérica.

The injection of bulking agents has been described as a useful treatment of urinary and fecal incontinence. Among them, silicone implants have shown benefits in patients with internal anal sphincter (IAS) injury. We describe two patients with a history of hemorrhoidectomy and IAS injuries, which underwent placement of silicone implants. The implants were inserted into the intersphincteric space and the IAS under ultrasound guidance. The Wexner continente score fell from 17 and 19 before treatment, to 6 and 8 at six months follow up, respectively. Patients had no postoperative complications or implants migration. In our patients, injection of silicone implants improved fecal continence score, without postoperative complications or implants migration at six month follow up.

Positive supercoiling of mitotic DNA drives decatenation by topoisomerase II in eukaryotes.

DNA topoisomerase II completely removes DNA intertwining, or catenation, between sister chromatids before they are segregated during cell division. How this occurs throughout the genome is poorly understood. We demonstrate that in yeast, centromeric plasmids undergo a dramatic change in their topology as the cells pass through mitosis. This change is characterized by positive supercoiling of the DNA and requires mitotic spindles and the condensin factor Smc2. When mitotic positive supercoiling occurs on decatenated DNA, it is rapidly relaxed by topoisomerase II. However, when positive supercoiling takes place in catenated plasmid, topoisomerase II activity is directed toward decatenation of the molecules before relaxation. Thus, a topological change on DNA drives topoisomerase II to decatenate molecules during mitosis, potentially driving the full decatenation of the genome.

[Surgical treatment of rectal cancer]. / Tratamiento quirúrgico del cáncer de recto.

Rectal affection accounts for 30% of colorectal cancer. The standard of treatment is surgical resection, which often is curative. For superior and middle-rectal involvement, low anterior resection (LAR) is the preferred procedure. For tumors involving the lower portion of the rectum, abdominoperineal resection (APR) or LAR are the options of treatment, depending on sphincter involvement. The main surgical objective is to achieve a R0 resection with an appropriated total mesorrectal excision, greater number of lymph nodes and negative distal and radial margins. These surgical parameters have been used as quality indicators and have prognostic implications in terms of overall and disease-free survival. Total mesorectal excision with preservation of hypogastric nerves has shown a reduction in rates of sexual and bladder dysfunction as well as lower local recurrence. At specialized centers such procedures are performed by minimal invasive surgery; however the number of meta-analysis is scarce.

Quantification of ovarian follicles in bluefin tuna Thunnus thynnus by two stereological methods.

The numbers of different types of ovarian follicles (developing, degenerating and postovulatory follicles) were estimated in bluefin tuna Thunnus thynnus using two stereological procedures: the model-based method of Weibel & Gomez, which has become a tool of broad application in the quantification of oocytes in fishes, and the assumption-free 'disector' (sic) method of Sterio. The estimates of developing follicles (follicles containing lipid-stage, vitellogenic and migratory-nucleus oocytes) made by the model-based method tended to be lower than those obtained with the disector, though significant differences were not observed except for vitellogenic follicles. Counts of atretic follicles by the model-based method were higher than those made using the disector, the differences being remarkable between both techniques, particularly in the case of beta-atresia, where the statistical analysis indicated significantly unequal estimations with the two methods. In contrast, the amount of postovulatory follicles estimated by the disector, which would stand for the realized batch fecundity, was somewhat larger than that calculated with the model-based method.

Physical linkages between sister chromatids and their removal during yeast chromosome segregation.

The fidelity of chromosome inheritance is of paramount importance to all living organisms. In eukaryotic cells, the strategy to ensure physical segregation of chromosomes to daughter cells relies on two basic steps ordered in time: an initial linkage, or cohesion, of sister chromatids and its timely and complete dissolution during anaphase. The current view is that these two basic steps are accomplished around the regulation of a protein complex called cohesin that serves as "clamp brackets" distributed at intervals throughout the genome. However, many of the DNA metabolic activities during interphase also produce physical linking of chromatids. For example, during replication, intertwines between sister chromatids are formed. Here, we review our understanding of the processes that generate physical linkages between chromatids and discuss potential mechanisms that are involved in the removal of such obstacles to the complete physical separation of chromatids at anaphase.

Increase in beta-lactam-resistant Proteus mirabilis strains due to CTX-M- and CMY-type as well as new VEB- and inhibitor-resistant TEM-type beta-lactamases.

OBJECTIVES: The aim of this study was to characterize the different inhibitor-resistant TEM beta-lactamases, extended-spectrum beta-lactamases (ESBLs) and plasmid-mediated AmpC beta-lactamases implicated in beta-lactam resistance in Proteus mirabilis, which has increased over recent years. METHODS: From February 2000 to December 2005, 1423 clinical isolates of P. mirabilis were collected. The AmpC phenotype was checked by means of a double-disc synergy test using cloxacillin as an inhibitor of AmpC enzymes. The production of ESBL was assessed by the double-disc synergy method and by Etest ESBL. Analytical isoelectric focusing, determination of kinetic constants, conjugation, PCR and a sequencing strategy were used to characterize the enzymes. The possible relationships between isolates were analysed by PFGE. RESULTS AND CONCLUSIONS: Twenty-five of 1423 isolates were found to display intermediate or full resistance to co-amoxiclav, cefotaxime or ceftazidime. Seventeen isolates had reduced susceptibility to co-amoxiclav; of these, seven produced TEM-110, eight produced the new TEM-159, one the new TEM-160 and one TEM-1. Five isolates producing TEM-110, TEM-159 or TEM-160 enzymes shared the same PFGE profile. Three isolates produced an ESBL, CTX-M-1, CTX-M-32 and the new variant, VEB-4. Finally, five isolates with an AmpC phenotype produced CMY-2, two with the same PFGE profile. Our data emphasize the diversity of beta-lactamases found in this species.

Clinical and microbiological features of nocardiosis 1997-2003.

Nocardiosis has been believed to be caused by the members of the Nocardia asteroides complex and the Nocardia brasiliensis species. However, recent advances in genotypic identification have shown that the genus exhibits considerable taxonomic complexity and the phenotypic markers used in the past for its identification can be ambiguous. The aim of this study was to assess the species distribution of Nocardia isolates and to determine whether there are differences in pathogenicity or antimicrobial susceptibility between the different species identified. Nocardia isolates obtained over a 7 year period were retrospectively reviewed. The isolates were identified genotypically, their antibiotic susceptibility was tested and the clinical data of the 27 patients were retrieved. Eight different Nocardia species were identified: Nocardia farcinica (n=9), Nocardia abscessus (n=6), Nocardia cyriacigeorgica (n=6), Nocardia otitidiscaviarum (n=2), Nocardia nova (n=1), N. nova complex (n=1), Nocardia carnea (n=1) and Nocardia transvalensis complex (n=1). All species were susceptible to co-trimoxazole but different patterns of susceptibility to other agents were observed. All patients had active comorbidities at the time of infection. A total of 19 patients were immunosuppressed, due to human immunodeficiency virus infection, chronic corticosteroid therapy, immunosuppressive therapy or haematological malignancies. Six patients displayed a Charlson comorbidity index score above 4. Global mortality was 50 % while attributable mortality was 34.6 %. Patients infected with N. farcinica--the most resistant species--had the highest Charlson index score and the highest mortality rate. Accurate identification of the species and susceptibility testing of Nocardia isolates may play an important role in diagnosis and treatment.

Quantificação de Listeria monocytogenes em salames fatiados embalados a vácuo / Occurrence of Listeria monocytogenes in pre-sliced vacuum-packaged

There is scarce information in Brazil and other South American countries about the occurrence of Listeria monocytogenes in food, mainly refrigerated ready-to-eat products. The consumption of sliced vacuum-packaged meat products has increased in the last few years. Nevertheless, a complete assessment of the risk associated with L. monocytogenes in these products is still necessary. Because of the production and storage characteristics of these products, they can be considered potential vehicles for L. monocytogenes to humans, mainly immunocompromised, elderly, and pregnant women. The objectives of this study was to evaluate the population of L. monocytogenes in salami, a ready-to-eat meat product with extended shelf life, acquired in retail stores in São Paulo-Brazil. The three-tube most probable number technique was used and the methodology was that from Health Canada. Strains were biochemically identified and serotyped. Among the 45 samples, 3 (6.7 per cent) harboured 9.2 MPN/g of L. monocytogenes and the others < 0.3 MPN/g. All the strains belonged to serotypes 1/2a and 1/2b, the most frequent serotypes found in food everywhere. Even being low, the population of L. monocytogenes found in this product could be a cause of concern to public health authorities as it can pose a threat to population at risk. This contamination highlights the importance of implementing systems like HACCP to assure safe products to consumers.

Cuidadoras inmigrantes de personas mayores / Inmigrant carers and elderly persons

No disponible

[Continuous quality improvement in the control of the type2 diabetes in Navarra. GEDAPSNA study 1996]. / Mejora continua de la calidad en el control del diabético tipo 2 en Navarra. Estudio GEDAPSNA 1996.

Diabetes mellitus type 2 constitutes one of the principal public health problems today, representing an important burden on care and involving extremely high economic costs, both direct and indirect. To provide an adequate response from the different public health systems, the St. Vincent Declaration was drawn up containing certain recommendations on the protocol of care and the carrying out of controls of continuous quality improvement, since it is a chronic pathology that requires a proactive health policy, which prevents, and provides early detection of its complications. In the present work we set out the results of the first study carried out in Navarra on the indicators of quality in the care provided to diabetics in Primary Health care, carried out by the Study Group on Diabetes Mellitus in Primary Care (GEDAPSNA). The study was made of an aleatory sample of 496 patients, by means of gathering data about their clinical records for the year 1996. 12 process indicators and 12 indicators of intermediate and final results were used. The results detect some important deficiencies that require early intervention: lack of exploration and management of the lesions that make up so-called diabetic foot; low achievement of results in the control of arterial hypertension in this group of patients; and absence of exploration of the lesions of the fundus of the eye in more than 50% of type 2 diabetics.

[Tobacco and health professionals]. / El tabaco y los profesionales de salud: situación actual.

INTRODUCTION: This work reviews current literature on the subject published in Spanish journals that study the attitudes, understanding and behaviour of health professionals concerning tobacco consumption. MATERIAL AND METHODS: 15 papers were selected that had been carried out using surveys similar to the WHO questionnaire for health professionals. RESULTS: A classification was made of the characteristics and results obtained, there has been a significant decline in the number of consumers, with no significant difference between professions. Differences are found by sex and by age, with a greater number of women smoking. This prevalence is higher in hospitals than in primary health care. CONCLUSIONS: A positive evolution in tobacco consumption amongst professionals, with figures that are lower than those for groups of the same age amongst the general population. The need to improve understanding in dealing with individuals who smoke.

Prediction of risk for drug use in high school students.

On the basis of questionnaires administered to almost 2,000 high school students in Cali, Colombia, a subset of items was selected that deal primarily with parent--child relationships. This 53-item set, referred to as the Drug Risk Scale (DRS), was administered to two new cross-validation samples, one consisting of high school students and the other consisting of drug addicts attending drug rehabilitation centers. Significant differences in parent--child relations were found between these new groups. The DRS was also found to have reasonably high sensitivity and specificity. Its potential value as a risk-prediction instrument is discussed.

Prediction of risk for drug use in high school students.

On the basis of questionnaires administered to almost 2,000 high school students in Cali, Colombia, a subset of items was selected that deal primarily with parent-child relationships. This 53 item set, referred to as the Drug Risk Scale (DRS), was administered to two new cross-validation samples, one consisting of high school students and the other consisting of drug addicts attending drug rehabilitation centers. Significant differences in parent-child relations were found between these new groups. The DRS was also found to have reasonably high sensitivity and specificity. Its potential value as a risk-prediction instrument is discussed.

[The migration problem in the pan-Amazon region: a theoretical approximation and a methodological alternative]. / El problema migratorio en la pan-amazonia: una aproximacion teorica y una alternativa metodologica

PIP: Some theoretical concepts concerning the study of migration in the Amazon region of South America are discussed. The concepts considered include differences in the definitions of the region used.^ieng