Potential Effect of Using ABO-Compatible Living-Donor Liver Transplantation

Liver transplantation increased 1.84-fold from 1988 to 2004. However, the number of patients on the waiting list for a liver increased 2.71-fold, from 553 to 1500. We used a mathematical equation to analyze the potential effect of using ABO-compatible living-donor liver transplantation (LDLT) on both our liver transplantation program and the waiting list. We calculated the prevalence distribution of blood groups (O, A, B, and AB) in the population and the probability of having a compatible parent or sibling for LDLT. The incidence of ABO compatibility in the overall population was as follows: A, 0.31; B, 0.133; O, 0.512; and AB, 0.04. The ABO compatibility for parent donors was blood group A, 0.174; B, 0.06; O, 0.152; and AB, 0.03; and for sibling donors was A, 0.121; B, 0.05; O, 0.354; and AB, 0.03. Use of LDLT can reduce the pressure on our liver transplantation waiting list by decreasing its size by at least 16.5% at 20 years after its introduction. Such a program could save an estimated 3600 lives over the same period.

POISSON DISTRIBUTION TO ANALYZE NEAR-THRESHOLD MOTOR EVOKED POTENTIALS

Motor unit action potentials (MUAPs) evoked by repetitive, low-intensity transcranial magnetic stimulation can be modeled as a Poisson process. A mathematical consequence of such a model is that the ratio of the variance to the mean of the amplitudes of motor evoked potentials (MEPs) should provide an estimate of the mean size of the individual MUAPs that summate to generate each MEP. We found that this is, in fact, the case. Our finding thus supports the use of the Poisson distribution to model MEP generation and indicates that this model enables characterization of the motor unit population that contributes to near-threshold MEPs. Muscle Nerve 42: 825-828, 2010

Evaluation of the Expression and Protective Potential of Leptospiral Sphingomyelinases

Leptospirosis is a zoonotic disease of global distribution, which affects both animals and humans. Pathogenic leptospires, the bacteria that cause this disease, require iron for their growth, and these spirochetes probably use their hemolysins, such as the sphingomyelinases, as a way to obtain this important nutrient from host red blood cells during infection. We expressed and purified the leptospiral sphingomyelinases Sph1, Sph2, Sph4, and SphH in a heterologous system. However, the recombinant proteins were not able to lyse sheep erythrocytes, despite having regular secondary structures. Transcripts for all sphingomyelinases tested were detected by RT-PCR analyses, but only Sph2 and SphH native proteins could be detected in Western blot assays using Leptospira whole extracts as well as in renal tubules of infected hamsters. Moreover, antibodies present in the serum of a human patient with laboratory-confirmed leptospirosis recognized Sph2, indicating that this sphingomyelinase is expressed and exposed to the immune system during infection in humans. However, in an animal challenge model, none of the sphingomyelinases tested conferred protection against leptospirosis.

Telehealth in audiology: The need and potential to reach underserved communities

Permanent hearing loss is a leading global health care burden, with 1 in 10 people affected to a mild or greater degree. A shortage of trained healthcare professionals and associated infrastructure and resource limitations mean that hearing health services are unavailable to the majority of the world population. Utilizing information and communication technology in hearing health care, or tele-audiology, combined with automation offer unique opportunities for improved clinical care, widespread access to services, and more cost-effective and sustainable hearing health care. Tele-audiology demonstrates significant potential in areas such as education and training of hearing health care professionals, paraprofessionals, parents, and adults with hearing disorders; screening for auditory disorders; diagnosis of hearing loss; and intervention services. Global connectivity is rapidly growing with increasingly widespread distribution into underserved communities where audiological services may be facilitated through telehealth models. Although many questions related to aspects such as quality control, licensure, jurisdictional responsibility, certification and reimbursement still need to be addressed; no alternative strategy can currently offer the same potential reach for impacting the global burden of hearing loss in the near and foreseeable future.

Distribution of fungi and aflatoxins in a stored peanut variety

The objective of the present study was to evaluate the mycoflora and occurrence of aflatoxins in stored peanut samples (hulls and kernels) from Tupa, State of Sao Paulo, Brazil. The samples were analyzed monthly over a period of one year. The results showed a predominance of Fusarium spp. (67.7% in hulls and 25.8% in kernels) and Aspergillus spp. (10.3% in hulls and 21.8% in kernels), and the presence of five other genera. The growth of Aspergillus flavus was mainly influenced by temperature and relative humidity. Analysis of hulls showed that 6.7% of the samples were contaminated with AFB(1) (mean levels 15-23.9 mu g/kg) and AFB(2) (mean levels = 3.3-5.6 mu g/kg); in kernels, 33.3% of the samples were contaminated with AFB(1) (mean levels 7.0-116 mu g/kg) and 28.3% were contaminated with AFB(2) (mean levels = 3.3-45.5 mu g/kg). Analysis of the toxigenic potential revealed that 93.8% of the A. flavus strains isolated were producers of AFB(1) and AFB(2). mu 2007 Elsevier Ltd. All rights reserved.

Inhibition of C6 rat glioma proliferation by [Ru(2)Cl(Ibp)(4)] depends on changes in p21, p27, Bax/Bcl2 ratio and mitochondrial membrane potential

The ruthenium compound [Ru(2)Cl(Ibp)(4)] (or RuIbp) has been reported to cause significantly greater inhibition of C6 glioma cell proliferation than the parent HIbp. The present study determined the effects of 0-72 h exposure to RuIbp upon C6 cell cycle distribution, mitochondrial membrane potential, reactive species generation and mRNA and protein expression of E2F1, cyclin D1, c-myc, pRb, p21, p27, p53, Ku70, Ku80, Bax, Bcl2, cyclooxygenase 1 and 2 (COX1 and COX2). The most significant changes in mRNA and protein expression were seen for the cyclin-dependent kinase inhibitors p21 and p27 which were both increased (p<0.05). The marked decrease in mitochondrial membrane potential (p<0.01) and modest increase in apoptosis was accompanied by a decrease in anti-apoptotic Bcl2 expression and an increase in pro-apoptotic Bax expression (p<0.05). Interestingly, COX1 expression was increased in response to a significant loss of prostaglandin E(2) production (p<0.001), most likely due to the intracellular action of Ibp. Future studies will investigate the efficacy of this novel ruthenium-ibuprofen complex in human glioma cell lines in vitro and both rat and human glioma cells growing under orthotopic conditions in vivo. (C) 2010 Elsevier Inc. All rights reserved.

The novel ruthenium-gamma-linolenic complex [Ru(2)(aGLA)(4)Cl] inhibits C6 rat glioma cell proliferation and induces changes in mitochondrial membrane potential, increased reactive oxygen species generation and apoptosis in vitro

The present study reports the synthesis of a novel compound with the formula [Ru(2)(aGLA)(4)Cl] according to elemental analyses data, referred to as Ru(2)GLA. The electronic spectra of Ru(2)GLA is typical of a mixed valent diruthenium(II,III) carboxylate. Ru(2)GLA was synthesized with the aim of combining and possibly improving the anti-tumour properties of the two active components ruthenium and gamma-linolenic acid (GLA). The properties of Ru(2)GLA were tested in C6 rat glioma cells by analysing cell number, viability, lipid droplet formation, apoptosis, cell cycle distribution, mitochondrial membrane potential and reactive oxygen species. Ru(2)GLA inhibited cell proliferation in a time and concentration dependent manner. Nile Red staining suggested that Ru(2)GLA enters the cells and ICP-AES elemental analysis found all increase in ruthenium from <0.02 to 425 mg/Kg in treated cells. The sub-G1 apoptotic cell population was increased by Ru(2)GLA (22 +/- 5.2%) when analysed by FACS and this was confirmed by Hoechst staining of nuclei. Mitochondrial membrane potential was decreased in the presence of Ru(2)GLA (44 +/- 2.3%). In contrast, the cells which maintained a high mitochondrial membrane potential had an increase (18 +/- 1.5%) in reactive oxygen species generation. Both decreased mitochondrial membrane potential and increased reactive oxygen species generation may be involved in triggering apoptosis in Ru(2)GLA exposed cells. The EC(50) for Ru(2)GLA decreased with increasing time of exposure from 285 mu M at 24h, 211 mu M at 48 h to 81 mu M at 72 h. In conclusion, Ru(2)GLA is a novel drug with anti proliferative properties in C6 glioma cells and is a potential candidate for novel therapies in gliomas. Copyright (C) 2009 John Wiley & Sons, Ltd.

The effect of additional Si and SiGe layers on the confinement potential of GeMn diluted ferromagnetic semiconductor

In this work we analyze the spin-polarized charge density distribution in the GeMn diluted ferromagnetic semiconductors (DFS). The calculations are performed within a self-consistent k.p method, in which the exchange correlation effects in the local density approximation, as well as the strain effects due to the lattice mismatch, are taken into account. Our findings show that the extra confinement potential provided by the barriers and the variation of the Mn content in the DFS are responsible for a separation between the different spin charge densities, giving rise to higher mobility spin-polarized currents or high ferromagnetism transition temperatures systems. (c) 2008 Elsevier B.V. All rights reserved.

Microbial distribution in the root canal system after periapical lesion induction using different methods

The aim of this study was to evaluate the microbial distribution in the root canal system after periapical lesion induction in dogs' teeth using different methods. Fifty-two root canals were assigned to 4 groups (n=13). Groups I and II: root canals were exposed to the oral cavity for 180 days; groups III and IV: root canals were exposed for 7 days and then the coronal openings were sealed for 53 days. The root apices of groups I and III were perforated, while those of groups II and IV remained intact. After the experimental periods, the animals were euthanized and the anatomic pieces containing the roots were processed and stained with the Brown & Brenn method to assess the presence and distribution of microorganisms. The incidence of microorganisms at different sites of the roots and periapical lesions was analyzed statistically by the chi-square test at 5% significance level. All groups presented microorganisms in the entire root canal system. A larger number of microorganisms was observed on the root canal walls, apical delta and dentinal tubules (p<0.05), followed by cementum and cemental resorption areas. In spite of the different periods of exposure to the oral environment, the methods used for induction of periapical periodontitis yielded similar distribution of microorganisms in the root canal system.

Distribution of biotypes and leukotoxic activity of Aggregatibacter actinomycetemcomitans isolated from Brazilian patients with chronic periodontitis

Aggregatibacter actinomycetemcomitans is an important etiologic agent of the periodontitis and is associated with extra-oral infections. In this study, the detection of the ltxA gene as well as the ltx promoter region from leukotoxic A. actinomycetemcomitans isolated from 50 Brazilian patients with periodontitis and 50 healthy subjects was performed. The leukotoxic activity on HL-60 cells was also evaluated. Leukotoxic activity was determined using a trypan blue exclusion method. The 530 bp deletion in the promoter region was evaluated by PCR using a PRO primer pair. A. actinomycetemcomitans was detected by culture and directly from crude subgingival biofilm by PCR using specific primers. By culture, A. actinomycetemcomitans was detected in nine (18%) of the periodontal patients and one (2%) healthy subject. However, by PCR, this organism was detected in 44% of the periodontal patients and in 16% of the healthy subjects. It was verified a great discrepancy between PCR detection of the ltx operon promoter directly from crude subgingival biofilm and from bacterial DNA. Only one periodontal sample harbored highly leukotoxic A. actinomycetemcomitans. Moreover, biotype II was the most prevalent and no correlation between biotypes and leukotoxic activity was observed. The diversity of leukotoxin expression by A. actinomycetemcomitans suggests a role of this toxin in the pathogenesis of periodontal disease and other infectious diseases.

Inequalities in the distribution of dental caries among 12-year-old Brazilian schoolchildren

We assessed the inequality in the distribution of dental caries and the association between indicators of socioeconomic status and caries experience in a representative sample of schoolchildren. This study followed a cross-sectional design, with a sample of 792 schoolchildren aged 12 years, representative of this age group in Santa Maria, RS, Brazil. Guardians answered questions on socioeconomic status and a dental examination provided information on the dental caries experience (DMF-T). Inequality in dental caries distribution was measured by the Gini coefficient and the Significant Caries Index (SiC). The assessment of association used Poisson regression models. Socioeconomic factors were associated with prevalence of dental caries for the whole sample and also for individuals with a high-caries level. Children from low-income households had the highest prevalence of dental caries. The Gini coefficient was 0.7 and the SiC Index 2.5. The percentage of caries prevalence was 39.3% (95% CI: 35.8%-42.8%) and the mean for DMF-T was 0.9 (± SD 1.5). Inequalities in the distribution of dental caries were observed and socioeconomic factors were found to be strong predictors of the prevalence of oral disease in children of this age group.

Nuclear and mitochondrial DNA markers in traceability of retail beef samples

Several characteristics are important in a traceability system of animal products, such as age at slaughter, breed composition, besides information of the productive chain. In general, the certification agent records information about the animals and the system which it came from, although cannot guarantee that the slaughtering, meat processing and distribution are error proof. Besides, there is a differential price, at least at the international market, based on sex and breed composition of the animals. Genetic markers allow identification of characteristics controlled in the beef cattle traceability program, as sex and breed composition, in order to correctly identify and appraise the final product for the consumer. The hypothesis of this study was that the majority beef samples retailed in the local market originate from female with a great participation of zebu breeds. Therefore, the objective of this work was to characterize retail beef samples with DNA markers that identify cattle sex and breed composition. Within 10 beef shops localized in Pirassununga, SP, Brazil, 61 samples were collected, all were genotyped as harboring Bos taurus mitochondrial DNA and 18 were positive for the Y chromosome amplification (male). For the marker sat1711b-Msp I the frequency of the allele A was 0.278 and for the marker Lhr-Hha I the frequency of the allele T was 0.417. The results of sat1711b-Msp I and Lhr-Hha I allelic frequencies are suggestive that the proportion of indicus genome compared with the taurine genome in the market meat is smaller than the observed in the Nellore breed. The procedure described in this study identified sex and subspecies characteristics of beef meat samples, with potential application in meat products certification in special as an auxiliary tool in beef cattle traceability programs.

Allelopathic evidence in Brachiaria decumbens and its potential to invade the Brazilian Cerrados

The aim of this study was to look for evidence of allelochemicals in B. decumbens, in parts of the plant from where they could easily be released to the environment. The germination inhibition of Phalaris canariensis, Lactuca sativa (standard species) and Melinis minutiflora, another invasive African grass, was tested using B. decumbens germinating seeds and aqueous leachates of the roots, green and senescent leaves, at 5, 10 and 20% w/v. Both the germinating seeds and the aqueous leachates of B. decumbens reduced the germination of the species tested; the effectiveness of the aqueous leachates increased according to concentration. Apparently, the competitive advantage of B. decumbens in the cerrados could be amplified via allelopathy.

A new species of the genus Pimelerodius Vanin from the Amazon Region, with notes on the geografic distribution of Pimelerodius motacilla (Boheman) (Coleoptera, Curculionidae, Otidocephalini)

Pimelerodius punctiventris sp. nov. (type locality Brazil, Amazonas, Itacoatiara) is described and illustrated. The new taxon is compared with similar species, being distinguished from the other 12 known species of the genus by the presence of punctures in ventrite I. The available published key for identification of species of Pimelerodius is adapted to include the new species. A modification of the generic description of the aedeagus of Pimelerodius is provided, a necessity due to the differences observed in the aedeagus of the new species. The occurrence of P. motacilla (Boheman, 1843) in the Amazon Region, recorded in sympatry with P. punctiventris in Itacoatiara, AM, is discussed and confirmed, based on the study of 41 available specimens.

Frog diversity in the Floresta Nacional de Chapecó, Atlantic Forest of southern Brazil

The Atlantic Forest is considered one of the world's biological diversity hotspots but is nevertheless increasingly threatened with the rapid destruction and fragmentation of its natural areas. In the state of Santa Catarina, southern Brazil, remnants of the mixed ombrophilous forest and seasonal deciduous forest exist as islands within large areas of agriculture, pastures and human settlements. Here we present information on species richness and habitat use by anurans in the Floresta Nacional de Chapecó, located in the western portion of the state of Santa Catarina. Anurans were surveyed by active search of potential reproductive sites from December 1998 to December 2001. A total of 29 species were recorded, most of which have a known distribution restricted to southern Brazil and adjacent countries (Argentina, Paraguay, and Uruguay) and use open areas for reproduction. The species composition was most similar to other areas of mixed ombrophilous forest and seasonal deciduous forest from the extreme south of Brazil. The information in this study may support the implementation of conservation and management strategies in the area.