Complicated acute type B dissection and endovascular repair: indications and pitfalls

In light of the morbidity and mortality associated with open repair of complicated acute type B dissection, endoluminal approaches provide an attractive option; however, the challenges of accurate placement within an angulated arch, size of the delivery system, and uncertainty regarding long-term durability have been cited as reasons for caution. This review examines the current literature regarding acute type B dissection and details the methods and potential pitfalls in endovascular management of these complex pathologies.     

Computerized detection of breast masses in digitized mammograms

We propose a system to detect malignant masses on mammograms. We investigated the behavior of an iris filter at different scales. After iris filter was applied, suspicious regions were segmented by means of an adaptive threshold. Suspected regions were characterized with features based on the iris filter output and, gray level, texture, contour-related, and morphological features extracted from the image. A backpropagation neural network classifier was trained to reduce the number of false positives. The system was developed and evaluated with two completely independent data sets. Results for a test set of 66 malignant and 49 normal cases, evaluated with free-response receiver operating characteristic analysis, yielded a sensitivity of 88% and 94% at 1.02 false positives per image for lesion-based and case-based evaluation, respectively. Results suggest that the proposed method could help radiologists as a second reader in mammographic screening.     

Hepatitis B virus genotypes and lamivudine resistance mutations in HIV/hepatitis B virus-coinfected patients

BACKGROUND: Differences in subtypes, hepatitis B early antigen (HBeAg)-negative variants, and drug resistance mutations all seem to influence the clinical and therapeutic outcome in patients with chronic hepatitis B virus (HBV) infection. Information available on the prevalence and distribution of distinct HBV variants in HIV-positive patients is scarce. METHODS: All HIV-infected patients with persistent serum hepatitis B surface antigen and detectable HBV viremia were identified in a reference HIV clinic located in Madrid, Spain. HBV load, subtypes, precore (PC) and basal core promoter (BCP) variants, and lamivudine (LAM) resistance mutations were analyzed. RESULTS: A total of 81 HBV/HIV-coinfected patients (4.1%) were identified in a population of 1968 HIV-positive patients. Plasma specimens with detectable HBV viremia could be obtained from 62 subjects, and this was the study population that underwent further virologic characterization. HBV genotype distribution was as follows: A (n = 27), D (n = 27), E (n = 1), F (n = 2), and G (n = 3). Two patients had mixed HBV genotypes (A/E and A/F). HBV subtype A was predominant (74%) among patients infected through sexual contact, whereas HBV-D was most frequent (74%) among intravenous drug users (P < 0.001). PC/BCP mutants were more frequent in patients with HBV-D than in those with HBV-A (63% vs. 18%; P < 0.01). Median time on LAM was 40 months; patients with HBV-A tended to show LAM resistance mutations more often (53% vs. 44%) and to develop them earlier (35 vs. 45 months) than patients with HBV-D. The dual L180M + M204V/I mutant was the predominant resistance pattern, although a triple rt173V + 180M + 204V, which acts as a vaccine escape mutant, was found in 1 individual. In the multivariate analysis, patients with LAM resistance mutations were significantly more frequently HBeAg-positive and older than individuals with wild-type HBV. Hepatitis-delta was recognized in 13 (21%) of these 62 HBV viremic patients, with no association with specific HBV variants. CONCLUSION: Risk transmission group, age, and positive serum HBeAg are the main determinants of distinct HBV virologic variants, including HBV genotypes and LAM-resistant mutants, in HBV/HIV-coinfected patients.     

Trace Metals Bioavailability Approach in Intertidal Estuarine Sediments and Bioaccumulation in Associated Nereidid Polychaetes

Polychaetes that inhabit the sediments of estuaries are important prey to many species all around the world. Laeonereis acuta is a deposit feeder living in estuaries along the Atlantic coast of South America. Ragworms accumulate metals from the sediment, and represent a means of entry of sediment contaminants into the trophic network. The concentrations of Zn, Pb, Cu, Cr and Cd were determined in polychaetes and sediments (total and extractable) from six estuarine beaches of Río de la Plata. The associations between total and extractable concentrations in sediment and accumulated concentrations in L. acuta were analyzed. Sediments extracted by weak acid digestion appear to be a good proxy model of bioavailable metal fractions in the sediment. The association between metals in sediment and polychaetes denotes the role of L. acuta as an important link in metal trophic transfer from sediments to potential fish and bird predators of the worm.     

HIV and malaria

Malaria and HIV infection are both prevalent in the areas of the world where these diseases have the largest burden. Both diseases interact with one another and this interaction is especially important in areas with non-continuous malaria transmission, in pregnant women, and in patients with more severe immunodeficiency. Malaria has been implicated in transitory higher viral load and in low CD4 counts, so it could have an influence on higher transmission rates of HIV and perhaps in the course of HIV infection. Infection with HIV has been shown to cause more clinical malaria and higher parasitemia in patients living in perennial transmission areas, and higher rates of severe malaria episodes and mortality in areas where malaria is transmitted with seasonal frequency. The HIV-infected patients have also higher rates of malaria treatment failures. Co-trimoxazole prophylaxis has been shown to be effective in the prevention of some opportunistic infections in HIV-infected patients, but also in prevention of malaria episodes. Antiretroviral protease inhibitors demonstrate antimalarial effects that could have important clinical and therapeutic implications. For all of these reasons, HIV and malaria should be considered together as part of healthcare programs for both diseases in countries where their co-presence favors an interaction with important clinical consequences.     

Effects of prenatal stress on motor performance and anxiety behavior in Swiss mice

Stressor presence during the last weeks of gestation has been associated with behavioral disorders in later life. In this study we support further research on the long term effects of prenatal stress on Swiss mice descendant's behavior. Prenatal stress procedure consisted on restraining the dams under bright light for 45 min, three times per day from the 15th day of pregnancy, until birth. After weaning, offspring's motor performance and spontaneous exploratory behavior were measured by the tight-rope and T-maze tests, respectively. We also evaluated anxiety behavior using elevated plus maze test. We found that maternal stress improves the performance of the animals in the tight rope test and that this effect was sex and age dependent: prenatal stressed males obtained the best scores during the first month of life, while in females the same was achieved at the second month. Spontaneous exploratory behavior analysis revealed that it was elevated in prenatal stressed males and that this effect persisted on time. However, we did not find significant differences on this behavioral response among both females groups. Finally, differences on anxiety behavior were found only in females: prenatally stressed animals showed a higher proportion of entries into the open arms of a plus maze (reduced anxiety) compared to the control group. Our results show that prenatal stress modifies the normal behavior of the progeny: prenatal stressed animals have a better performance in the carried out test. These notably results suggest the existence of an adaptive response to prenatal stress.     

Association of putative enteroaggregative Escherichia coli virulence genes and biofilm production in isolates from travelers to developing countries

Enteroaggregative Escherichia coli (EAEC) is an emerging enteric pathogen that causes acute and chronic diarrhea among children, human immunodeficiency virus-infected patients, and travelers to developing regions of the world. The pathogenesis of EAEC strains involves the production of biofilm. In this study, we determined the association between presence of putative EAEC virulence genes and biofilm formation in 57 EAEC isolates (as defined by HEp-2 adherence) from travelers with diarrhea and in 18 EAEC isolates from travelers without diarrhea. Twelve nondiarrheagenic E. coli isolates from healthy travelers were used as controls. Biofilm formation was measured by using a microtiter plate assay with the crystal violet staining method, and the presence of the putative EAEC virulence genes aap, aatA, aggR, astA, irp2, pet, set1A, and shf was determined by PCR. EAEC isolates were more likely to produce biofilm than nondiarrheagenic E. coli isolates (P = 0.027), and the production of biofilm was associated with the virulence genes aggR, set1A, aatA, and irp2, which were found in 16 (40%), 17 (43%), 10 (25%), and 27 (68%) of the biofilm producers versus only 4 (11%), 6 (6%), 2 (6%), and 15 (43%) in non-biofilm producers (P = 0.008 for aggR, P = 0.0004 for set1A, P = 0.029 for aatA, and P = 0.04 for irp2). Although the proportion of EAEC isolates producing biofilm in patients with diarrhea (51%) was similar to that in patients without diarrhea (61%), biofilm production was related to the carriage of aggR (P = 0.015), set1A (P = 0.001), and aatA (P = 0.025). Since aggR is a master regulator of EAEC, the presence of aap (P = 0.004), astA (P = 0.001), irp2 (P = 0.0006), pet (P = 0.002), and set1A (P = 0.014) in an aggR versus an aggR-lacking background was investigated and was also found to be associated with biofilm production. This study suggests that biofilm formation is a common phenomenon among EAEC isolates derived from travelers with or without diarrhea and that multiple genes associated with biofilm formation are regulated by aggR.     

Utilidad de los estudios serológicos en los centros de Atención Primaria para el diagnóstico precoz de la enfermedad de Lyme

Objective

The main aim of this study was to determine the usefulness of an early diagnosis of Lyme disease (LD) in Primary Health Care Centres (PHCC) using the ELISA test as serological screening technique.

Validation of the Sexual Inhibition and Sexual Excitation Scales (SIS/SES) in Portugal: Assessing Gender Differences and Predictors of Sexual Functioning

The Sexual Inhibition and Sexual Excitation Scales (SIS/SES) were developed to assess individual propensities for sexual excitation and sexual inhibition in men and women. The objective of the present study was to validate the Portuguese version of the SIS/SES and to investigate the degree to which SIS/SES scores predict different dimensions of Portuguese men’s and women’s sexual functioning. Gender differences were also examined. A community sample of 370 Portuguese men and 373 women completed self-report measures of sexual function (IIEF, Rosen et al., 1997; FSFI, Rosen et al., 2000) and of the propensity for sexual inhibition and sexual excitation (SIS/SES, Janssen et al., 2002a). Exploratory factor analysis revealed a three-factor solution further supported by confirmatory factor analysis. The three factors identified resemble the original ones, and reliability analyses indicated they have both satisfactory internal consistency and stability over time. Age and Sexual Inhibition Due to the Threat of Performance Failure (SIS1) were both significant negative predictors of men’s sexual desire, erectile function, and orgasm. Sexual Excitation (SES) was a positive predictor of sexual desire in both men and women and of men’s erectile function and of women’s lubrication and orgasm. Age was also a significant and negative predictor of women’s sexual desire. Significant gender differences were found for all three SIS/SES scales with men having significantly higher excitation and lower inhibition scores as compared to women. The Portuguese version of the SIS/SES was shown to be suitable for use within the Portuguese population in both clinical and basic research. Our findings provide further cross-cultural validation of the Dual Control Model of Sexual Response and underscore the importance of the role of excitatory and inhibitory processes in women’s and men’s sexual functioning and response.