[The experience of medical students as peer tutors]. / Rol de tutor par: experiencia de estudiantes de medicina.

BACKGROUND: Peer tutoring is a process of accompaniment carried out by a student with certain features and skills, whose objective is to support and guide, academically and emotionally, other students who may require it. AIM: To assess the experience of medical students who played the role of peer tutor. MATERIAL AND METHODS: We carried out semi-structured in-depth interviews, with prior informed consent, to a non-probabilistic and intentional sample of six students who performed the role of peer tutor, during 2017 and 2018. The data analysis followed the scheme of constant comparison and progressive reduction in a manual way, according to the comparative method, guaranteeing scientific rigor, maintaining criteria of credibility, dependence, confirmability, and transferability. RESULTS: The first level identified 234 units of meaning that originated in the third level, two qualitative domains, oriented to the contribution of peer tutors derived from their experience to strengthen both the process of peer tutor training and the management of peer tutoring. CONCLUSIONS: Peer tutoring as a teaching-learning strategy contributes to the development of generic competences and metacognitive skills, generating high levels of personal satisfaction and identification their teaching role.

Rol de tutor par: experiencia de estudiantes de medicina / The experience of medical students as peer tutors

Background: Peer tutoring is a process of accompaniment carried out by a student with certain features and skills, whose objective is to support and guide, academically and emotionally, other students who may require it. Aim: To assess the experience of medical students who played the role of peer tutor. Material and Methods: We carried out semi-structured in-depth interviews, with prior informed consent, to a non-probabilistic and intentional sample of six students who performed the role of peer tutor, during 2017 and 2018. The data analysis followed the scheme of constant comparison and progressive reduction in a manual way, according to the comparative method, guaranteeing scientific rigor, maintaining criteria of credibility, dependence, confirmability, and transferability. Results: The first level identified 234 units of meaning that originated in the third level, two qualitative domains, oriented to the contribution of peer tutors derived from their experience to strengthen both the process of peer tutor training and the management of peer tutoring. Conclusions: Peer tutoring as a teaching-learning strategy contributes to the development of generic competences and metacognitive skills, generating high levels of personal satisfaction and identification their teaching role.

Phage cocktail SalmoFREE® reduces Salmonella on a commercial broiler farm.

According to the World Health Organization, Salmonella is one of the most important zoonotic foodborne pathogens. Poultry products are thought to be the main source of Salmonella, which means that it is necessary to control Salmonella at the pre-harvest stage. Bacteriophages, acting as host-specific parasites of bacterial cells, represent one of the alternatives to antibiotics that can contribute to food safety and security. The present study evaluated the effectiveness of the bacteriophage cocktail SalmoFREE® to control Salmonella on a commercial broiler farm. We assessed the relationship between the use of SalmoFREE® and productivity parameters (feed conversion, weight gain, homogeneity). Two field trials (trial 1 n = 34,986; trial 2 n = 34,680) were carried out under commercial rearing conditions on a Colombian broiler farm with a record of Salmonella presence. Each trial comprised 2 control chicken houses and 2 experimental ones. SalmoFREE® and a control suspension were delivered in the drinking water at 3 time points in the production cycle, and the presence of Salmonella was assessed in cloacal swabs the day before and after the treatments. Results revealed that SalmoFREE® controls the incidence of Salmonella and does not affect the animals nor the production parameters, demonstrating its efficacy and innocuity at the production scale. We detected phage-specific genes in samples of total DNA extracted from ceca after the treatment with SalmoFREE®, and tested for the appearance of cocktail-resistant Salmonella, which showed to be an uncommon event. These results contribute relevant information to the adoption of phage therapy as an alternative to growth-promoter antibiotics on poultry farms.

Copy number variants of Ras/MAPK pathway genes in patients with isolated cryptorchidism.

Cryptorchidism is the most common congenital disorder in boys, but the cause for most cases remains unknown. Patients with Noonan Syndrome are characterized by a typical face, growth retardation, congenital heart defects, learning disabilities and cryptorchidism. Copy number variations of Ras/MAPK pathway genes are unusual in patients with several clinical features of Noonan Syndrome; however, they have not been studied in patients with only one feature of this condition, such as cryptorchidism. Our aim was to determine whether patients with isolated cryptorchidism exhibit Ras/MAPK pathway gene copy number variations (CNVs). Fifty-nine patients with isolated cryptorchidism and negative for mutations in genes associated with Noonan Syndrome were recruited. Determination of Ras/MAPK pathway gene CNVs was performed by Comparative Genome Hybridization array. A CNV was identified in two individuals, a ~175 kb microduplication at 3p25.2, partially including RAF1. A similar RAF1 microduplication has been observed in a patient with testicular aplasia. This suggests that some patients with isolated cryptorchidism may harbor Ras/MAPK pathway gene CNVs.

Detection of linezolid resistance due to the optrA gene in Enterococcus faecalis from poultry meat from the American continent (Colombia).

Background: Three Enterococcus isolates obtained from retail chicken collected in 2010-11 as part of the Colombian Integrated Program for Antimicrobial Resistance Surveillance (COIPARS) showed reduced susceptibility towards linezolid (MIC 8 mg/L). Objectives: This study aimed at characterizing the isolates resistant to linezolid and detecting the resistance mechanism. Methods: Strains were analysed in 2011-12 without successful detection of the resistance mechanism. All isolates were found negative for the cfr gene and no 23S rRNA mutations were detected. In 2016, with the novel resistance gene optrA being described, the WGS data were re-analysed using in silico genomic tools for confirmation of species, detection of virulence and resistance genes, MLST and SNP analyses and comparison of the genetic environment with the previously published plasmid pE349. Results: : Three Enterococcus faecalis isolates were found positive for the optrA gene encoding resistance to linezolid and phenicols. Additional screening of 37 enterococci strains from the same study did not detect any further positives. Typing showed that two of the isolates belong to ST59, while the last belongs to ST489. All isolates carry genes encoding resistance to macrolide-lincosamide-streptogramin B, tetracycline and phenicols. In addition, the ST489 isolate also carries genes conferring aminoglycoside resistance and is resistant to quinolones, but no plasmid-mediated gene was detected. The optrA gene regions of the three plasmids showed high similarity to the originally reported optrA -carrying plasmid pE349. Conclusions: To the best of our knowledge, this is the first description of the optrA gene in E. faecalis isolated from poultry meat in the Americas.

ATP leakage induces P2XR activation and contributes to acute synaptic excitotoxicity induced by soluble oligomers of ß-amyloid peptide in hippocampal neurons.

Recent studies suggest that the toxic effects of Aß can be attributed to its capability to insert in membranes and form pore-like structures, which are permeable to cations and molecules such as ATP. Our working hypothesis is that Aß increases extracellular ATP causing activation of P2X receptors and potentiating excitatory synaptic activity. We found that soluble oligomers of ß-amyloid peptide increased cytosolic Ca(2+) 4-fold above control (415 ± 28% of control). Also, ATP leakage (157 ± 10% of control) was independent of extracellular Ca(2+), suggesting that ATP traveled from the cytosol through an Aß pore-mediated efflux and not from exocytotic mechanisms. The subsequent activation of P2XR by ATP can contribute to the cytosolic Ca(2+) increase observed with Aß. Additionally, we found that ß-amyloid oligomers bind preferentially to excitatory neurons inducing an increase in excitatory synaptic current frequency (248.1 ± 32.7%) that was blocked by the use of P2XR antagonists such as PPADS (Aß + PPADS: 110.9 ± 18.35%) or Apyrase plus DPCPX (Aß + inhibitors: 98.97 ± 17.4%). Taken together, we suggest that Aß induces excitotoxicity by binding preferentially to excitatory neuron membranes forming a non-selective pore and by increasing intracellular calcium by itself and through P2XR activation by extracellular ATP leading to an augmention in mEPSC activity. All these effects were blocked with a non-specific P2XR antagonist, indicating that part of the neurotoxicity of Aß is mediated by P2XR activation and facilitation of excitatory neurotransmitter release. These findings suggest that P2XR can be considered as a potential new target for the development of drugs or pharmacological tools to treat Alzheimer's disease. This article is part of the Special Issue entitled 'Synaptopathy--from Biology to Therapy'.

Modulation of the neuronal network activity by P2X receptors and their involvement in neurological disorders.

ATP is a key energetic molecule, fundamental to cell function, which also has an important role in the extracellular milieu as a signaling molecule, acting as a chemoattractant for immune cells and as a neuro- and gliotransmitter. The ionotropic P2X receptors are members of an ATP-gated ion channels family. These ionotropic receptors are widely expressed through the body, with 7 subunits described in mammals, which are arranged in a trimeric configuration with a central pore permeable mainly to Ca(2+) and Na(+). All 7 subunits are expressed in different brain areas, being present in neurons and glia. ATP, through these ionotropic receptors, can act as a neuromodulator, facilitating the Ca(2+)-dependent release of neurotransmitters, inducing the cross-inhibition between P2XR and GABA receptors, and exercising by this way a modulation of synaptic plasticity. Growing evidence shows that P2XR play an important role in neuronal disorders and neurodegenerative diseases, like Parkinson's and Alzheimer's disease; this role involves changes on P2XR expression levels, activation of key pathways like GSK3ß, APP processing, oxidative stress and inflammatory response. This review is focused on the neuromodulatory function of P2XR on pathophysiological conditions of the brain; the recent evidence could open a window to a new therapeutic target.

The Establishment of the Colombian Integrated Program for Antimicrobial Resistance Surveillance (COIPARS): A Pilot Project on Poultry Farms, Slaughterhouses and Retail Market.

The development of antimicrobial resistance among bacteria (AMR) is currently one of the world's most pressing public health problems. The use of antimicrobial agents in humans and animals has resulted in AMR which has narrowed the potential use of antibiotics for the treatment of infections in humans. To monitor AMR and to develop control measures, some countries, such as the USA, Canada and Denmark, have established national integrated surveillance systems (FDA, , CIPARS, 2007, DANMAP,2002). The components of these programs monitor changes in susceptibility/resistance to antimicrobial agents of selected zoonotic pathogens and commensal organisms recovered from animals, retail meats and humans. The rapid development of Colombia's animal production industry has raised food safety issues including the emergence of antibiotic resistance. The Colombian Integrated Surveillance Program for Antimicrobial Resistance (COIPARS) was established as a pilot project to monitor AMR on poultry farms, slaughter houses and retail markets.

Ionizing radiation-induced gene expression changes in TP53 proficient and deficient glioblastoma cell lines.

The genetic heterogeneity presented by different cell lines derived from glioblastoma (GBM) seems to influence their responses to antitumoral agents. Although GBM tumors present several genomic alterations, it has been assumed that TP53, frequently mutated in GBM, may to some extent be responsible for differences in cellular responses to antitumor agents, but this is not clear yet. To directly determine the impact of TP53 on GBM response to ionizing radiation, we compared the transcription profiles of four GBM cell lines (two with wild-type (WT) TP53 and two with mutant (MT) TP53) after 8Gy of gamma-rays. Transcript profiles of cells analyzed 30 min and 6h after irradiation showed that WT TP53 cells presented a higher number of modulated genes than MT TP53 cells. Our findings also indicate that there are several pathways (apoptosis, DNA repair/stress response, cytoskeleton organization and macromolecule metabolic process) in radiation responses of GBM cell lines that were modulated only in WT TP53 cells (30 min and 6h). Interestingly, the majority of differentially expressed genes did not present the TP53 binding site, suggesting secondary effects of TP53 on transcription. We conclude that radiation-induced changes in transcription profiles of irradiated GBM cell lines mainly depend on the functional status of TP53.

Prevalence, risk factors, and antimicrobial resistance profiles of Salmonella from commercial broiler farms in two important poultry-producing regions of Colombia.

Salmonella is one of the most common foodborne pathogens associated with diarrheal disease in humans. Food animals, especially poultry, are important direct and indirect sources of human salmonellosis, and antimicrobial resistance is an emerging problem of public health concern. The use of antimicrobials benefits producers but contributes to the emergence of antimicrobial resistant bacteria. As a step toward implementing the Colombian Integrated Program for Antimicrobial Resistance Surveillance, this study was conducted to establish the prevalence, distribution of serovars, antimicrobial resistance profiles, and risk factors for Salmonella on poultry farms in the two largest states of poultry production in Colombia. Salmonella was isolated from 41% of farms and 65% of the 315 chicken houses sampled. Salmonella Paratyphi B variant Java was the most prevalent serovar (76%), followed by Salmonella Heidelberg (23%). All Salmonella isolates were resistant to 2 to 15 of the antimicrobial drugs tested in this study. For Salmonella Paratyphi B variant Java, 34 drug resistance patterns were present. The predominant resistance pattern was ciprofloxacin, nitrofurantoin, tetracycline, trimethoprim-sulfamethoxazole, ceftiofur, streptomycin, enrofloxacin, and nalidixic acid; this pattern was detected in 15% of isolates. The resistance pattern of tetracycline, ceftiofur, and nalidixic acid was found in over 40% of the isolates of Salmonella Heidelberg. Of the biosecurity practices considered, two factors were significantly associated with reduction in Salmonella: cleaning of fixed equipment and composting of dead birds on the farm. Findings from the present study provide scientific evidence to inform implementation of official policies that support new biosecurity legislation in an effort to decrease the prevalence of Salmonella on Colombian poultry farms.

Colestasias familiares: una causa común de hiperbilirrubinemia conjugada / Familial cholestasis: a comon cause of conjugated hyperbilurubinemia

Cholestasis is defined as a disorder affecting the production of bile resulting in the retention of its components in the liver and blood. In children, this disorder is almost always due to genetic alterations. Functionally, cholestasis may be the result of hepatic failure to secrete bile due to decrease in transport, synthesis or biliary obstruction. Extrahepatic cholestasis may be caused by biliary atresia and other obstructions of the bile ducts. Intrahepatic cholestasis may be the result of several disorders including progressive familial intrahepatic cholestasis (PFIC) types 1, 2 and 3, an autosomal recessive disease due to mutations in the genes ATP8B1, ABCBll and ABCB4 respectively. Pathophysiology and clinical presentation of this disease are now well understood. Clinically, these patients may present with jaundice, itching, anorexia, and generally unwell. Laboratory tests may disclose conjugated bilirubin over lmg/dl or larger than 20 percent of total bilirubin. Ursodeoxycholic acid, cholestiramine and biliary diversion may help in some of these conditions. Ongoing research into the mechanisms of genetic cholestasis could be key to therapy.

La Colestasia corresponde a un trastorno en la formación y excreción de la bilis que provoca retención de sus componentes y daño en hígado y sangre. La colestasia en el niño casi siempre se debe a una alteración hepática secundaria a causas ahora mayormente conocidas a nivel molecular. Desde el punto de vista funcional la colestasia resulta de una insuficiencia secretora del hígado debido a una disminución del flujo biliar por falla en los procesos de transporte o síntesis o a una obstrucción de la vía biliar. La colestasia extrahepática incluye la atresia de vías biliares y otras obstrucciones de la vía biliar. La colestasia intrahepática incluye las colestasias progresivas familiares PFIC 1, 2 y 3 causadas por fallas en los genes ATP8B1, ABCBll y ABCB4 respectivamente. Clínicamente pueden presentarse con ictericia, prurito, anorexia y compromiso del estado general. Desde el punto de vista del laboratorio las enfermedades colestásicas se caracterizan por hiperbilirrubinemia conjugada mayor a 1 mg/dl o mayor a 20 por ciento de bilirrubina total.

[Prevalence and risk factors associated with postpartum depression in puerperal women consulting in primary care]. / Prevalencia y factores de riesgo asociados a la depresión posparto en puérperas de un Centro de Atención Primaria en el Sur de Chile.

BACKGROUND: Mood disorders are common in Chile. Among these, post partum depression (PPD) deranges the maternal and family relationships. AIM: To determine the prevalence and risk factors associated with PPD in puerperal women in Temuco, Chile. MATERIAL AND METHODS: The Edinburgh Postnatal Depression Scale was administered to 73 puerperal women aged 15 to 32 years, between 40 to 45 days after delivery. To detect risk factors, 20 women with and 20 women without post partum depression (PPD) were interviewed and their clinical records were reviewed to assess their perinatal care. RESULTS: The prevalence of PPD in the whole sample was 50.7%. The individual psychological risk factors detected were a feeling of discomfort with their body after giving birth, a personal history of mental health problems and a high level of overload associated to child care. An individual physical risk factor was alcohol consumption during pregnancy. Family risk factors were a poor relationship with the father of the child during pregnancy, a history of mental health problems in close family members, a history of family violence and a poor relationship with parents during puerperium. Having more children was a sociodemographic risk factor. CONCLUSIONS: Post partum depression is common. The characterization of risk factors should lead to the implementation of preventive strategies.

Prevalencia y factores de riesgo asociados a la depresión posparto en puérperas de un Centro de Atención Primaria en el Sur de Chile / Prevalence and risk factors associated with postpartum depression in puerperal women consulting in primary care

Background: Mood disorders are common in Chile. Among these, post partum depression (PPD) deranges the maternal and family relationships. Aim: To determine the prevalence and risk factors associated with PPD in puerperal women in Temuco, Chile. Material and methods: The Edinburgh Postnatal Depression Scale was administered to 73 puerperal women aged 15 to 32 years, between 40 to 45 days after delivery. To detect risk factors, 20 women with and 20 women without post partum depression (PPD) were interviewed and their clinical records were reviewed to assess their perinatal care. Results: The prevalence of PPD in the whole sample was 50.7 percent. The individual psychological risk factors detected were a feeling of discomfort with their body after giving birth, a personal history of mental health problems and a high level of overload associated to child care. An individual physical risk factor was alcohol consumption during pregnancy. Family risk factors were a poor relationship with the father of the child during pregnancy, a history of mental health problems in close family members, a history of family violence and a poor realtionship with parents during puerpurium. Having more children was a sociodemographic risk factor. Conclusions: Pospartum depression is common. The characterization of risk factors should lead to the implementation of preventive strategies.

Transcriptional changes in U343 MG-a glioblastoma cell line exposed to ionizing radiation.

Glioblastoma multiforme (GBM) is a highly invasive and radioresistant brain tumor. Aiming to study how glioma cells respond to gamma-rays in terms of biological processes involved in cellular responses, we performed experiments at cellular context and gene expression analysis in U343-MG-a GBM cells irradiated with 1 Gy and collected at 6 h post-irradiation. The survival rate was approximately 61% for 1 Gy and was completely reduced at 16 Gy. By performing the microarray technique, 859 cDNA clones were analyzed. The Significance Analysis of Microarray algorithm indicated 196 significant expressed genes (false discovery rate (FDR) = 0.42%): 67 down-regulated and 97 up-regulated genes, which belong to several classes: metabolism, adhesion/cytoskeleton, signal transduction, cell cycle/apoptosis, membrane transport, DNA repair/DNA damage signaling, transcription factor, intracellular signaling, and RNA processing. Differential expression patterns of five selected genes (HSPA9B, INPP5A, PIP5K1A, FANCG, and TPP2) observed by the microarray analysis were further confirmed by the quantitative real time RT-PCR method, which demonstrated an up-regulation status of those genes. These results indicate a broad spectrum of biological processes (which may reflect the radio-resistance of U343 cells) that were altered in irradiated glioma cells, so as to guarantee cell survival.

Cinética do fósforo em tecidos de ovinos em crescimento alimentados com diferentes fontes de cálcio / Kinetics of phosphorus in tissues of lambs fed different sources of calcium

Foram utilizados 12 cordeiros machos, inteiros, com peso médio de 31,6kg. Os cordeiros foram alimentados com dietas à base de milho e farelo de soja, suplementadas com diferentes fontes de cálcio: calcário calcítico (CC), feno de alfafa (FA), polpa cítrica (PC) e farinha de conchas de ostras (FCO). Os animais receberam injeção de 7,4 MBq do radiofósforo (32P) e após sete dias foram abatidos para posteriores análises. Utilizou-se o delineamento em blocos ao acaso, com quatro tratamentos e três repetições. A taxa de retenção de 32P, as atividades específicas relativas e padronizadas, e a quantidade de P inorgânico nos tecidos foram iguais para todos os tratamentos (P>0,05). A comparação entre os tecidos mostrou que a concentração de P inorgânico e a taxa de retenção de 32P (P<0,01) foram mais altas nos ossos em relação aos tecidos moles (P<0,01). A retenção de 32P apresentou a seguinte ordem decrescente: rins, fígado, coração, músculos e ossos (P<0,01). A reabsorção óssea de P foi maior que a deposição de P, levando ao balanço negativo do elemento para a maioria dos animais. Concluiu-se que as diferentes fontes de cálcio não interferiram na cinética do P e que a quantidade de P ingerida não atendeu às exigências de P dos animais.

Sixteen growing rams, averaging 31.6kg were studied. They were fed diets based on corn and soya meal, supplemented with different sources of calcium: limestone (CC), alfalfa hay (FA), citrus pulp (PC) and oyster shell meal (OSM). The animals received an injection of 7.4 MBq of radioactive P (32P) and after 7 days they were slaughtered for further analyses. Experimental measurements were analyzed as a completely randomized design with four treatments and three repetitions. The rate of 32P retention, the relative specific activity, the standardized specific activity and the inorganic P in tissue were similar for all treatments (P>0.05). The comparison between tissues showed that the concentration of inorganic P and rate of 32P retention was greater in bone (P<0.01) than in soft tissue. The 32P retention presented the following decreasing order: kidney, liver, heart, muscle and bone (P<0.01). P resorption in bone was higher than P accreted in bone, leading to a negative balance of P in bone for the majority of animals. The means for P accreted in bone were 1.56, 3.29, 2.74 and 2.06g/animal and the means for P resorption in bone were 2.82, 4.51, 4.09 and 3.05g/animal for limestone (CC), alfalfa hay (FA), citrus pulp (PC) and oyster shell meal (OSM), respectively. P resorption values were higher than P accretion in bone leading to a negative balance of P for the majority of animals. It was concluded that the different sources of calcium did not interfere in the kinetics of phosphorus and the amount of P absorbed did not attend P demands of the animals.

Cinética do fósforo em tecidos de ovinos em crescimento alimentados com diferentes fontes de cálcio / Kinetics of phosphorus in tissues of lambs fed different sources of calcium

Foram utilizados 12 cordeiros machos, inteiros, com peso médio de 31,6kg. Os cordeiros foram alimentados com dietas à base de milho e farelo de soja, suplementadas com diferentes fontes de cálcio: calcário calcítico (CC), feno de alfafa (FA), polpa cítrica (PC) e farinha de conchas de ostras (FCO). Os animais receberam injeção de 7,4 MBq do radiofósforo (32P) e após sete dias foram abatidos para posteriores análises. Utilizou-se o delineamento em blocos ao acaso, com quatro tratamentos e três repetições. A taxa de retenção de 32P, as atividades específicas relativas e padronizadas, e a quantidade de P inorgânico nos tecidos foram iguais para todos os tratamentos (P>0,05). A comparação entre os tecidos mostrou que a concentração de P inorgânico e a taxa de retenção de 32P (P<0,01) foram mais altas nos ossos em relação aos tecidos moles (P<0,01). A retenção de 32P apresentou a seguinte ordem decrescente: rins, fígado, coração, músculos e ossos (P<0,01). A reabsorção óssea de P foi maior que a deposição de P, levando ao balanço negativo do elemento para a maioria dos animais. Concluiu-se que as diferentes fontes de cálcio não interferiram na cinética do P e que a quantidade de P ingerida não atendeu às exigências de P dos animais.(AU)

Sixteen growing rams, averaging 31.6kg were studied. They were fed diets based on corn and soya meal, supplemented with different sources of calcium: limestone (CC), alfalfa hay (FA), citrus pulp (PC) and oyster shell meal (OSM). The animals received an injection of 7.4 MBq of radioactive P (32P) and after 7 days they were slaughtered for further analyses. Experimental measurements were analyzed as a completely randomized design with four treatments and three repetitions. The rate of 32P retention, the relative specific activity, the standardized specific activity and the inorganic P in tissue were similar for all treatments (P>0.05). The comparison between tissues showed that the concentration of inorganic P and rate of 32P retention was greater in bone (P<0.01) than in soft tissue. The 32P retention presented the following decreasing order: kidney, liver, heart, muscle and bone (P<0.01). P resorption in bone was higher than P accreted in bone, leading to a negative balance of P in bone for the majority of animals. The means for P accreted in bone were 1.56, 3.29, 2.74 and 2.06g/animal and the means for P resorption in bone were 2.82, 4.51, 4.09 and 3.05g/animal for limestone (CC), alfalfa hay (FA), citrus pulp (PC) and oyster shell meal (OSM), respectively. P resorption values were higher than P accretion in bone leading to a negative balance of P for the majority of animals. It was concluded that the different sources of calcium did not interfere in the kinetics of phosphorus and the amount of P absorbed did not attend P demands of the animals.(AU)

Membrane and extracellular antigens of Paracoccidioides brasiliensis (Mexo): identification of a 28-kDa protein suitable for immunodiagnosis of paracoccidioidomycosis.

In this work, we analyzed serological responses of paracoccidioidomycosis (PCM) patients to membrane and extracellular antigens (Mexo) of Paracoccidioides brasiliensis by ELISA, immunoblot technique and immunofluorescence assays to identify a specific antigen profile. Among 140 PCM serum samples analyzed, a homogeneous IgG response to Mexo was observed. The specificity of this antigen was 96.6% in relation to control sera and 81.2% to sera from patients with diverse infections. Patients undergoing treatment for more than 1 year showed a reduced antibody response against Mexo. These results suggest that the presence of anti-Mexo antibodies might be an indicator of active disease. A protein from Mexo with a molecular weight of 28 kDa (Pb28) was the most specific antigen in humoral immune responses to PCM, since it reacted with 100% of patient sera and did not react with heterologous serum samples tested. This protein was purified by molecular filtration chromatography in FPLC system and, when tested by immunoblotting, it maintained its reactivity and specificity of 100% with PCM sera. The Pb28 N-terminal amino acid sequence comparison analysis in the non-redundant GenBank database at NCBI revealed no significant homology to known PCM proteins or to other fungal proteins of known function. Since the 28-kDa protein of P. brasiliensis seems to be specific for PCM, it can be used as an alternative antigen in immunoblotting diagnostic methods.

Ventilación no invasiva como tratamiento de la insuficiencia respiratoria aguda en Pediatría / Pediatric non-invasive ventilation for acute respiratory failure in an Intermediate Care Unit

Background: Pediatric noninvasive ventilation (NIV) is infrequently used for acute respiratory failure (ARF), BiPAP/CPAP applied through nasal mask can be attempted if strict selection rules are defined. Aim: To evaluate the outcome of NIV in a Pediatric Intermediate Care Unit. Material and methods: The medical records of 14 patients (age range 1 month-13 years, six female), who participated in a prospective protocol of NIV from January to October 2004, were reviewed. Oxygen therapy, delivered through a reservoir bag attached to the ventilation circuit, was used to maintain SaO2 over 90%. Results: The main indication of BiPAP, in 80% of cases, was pulmonary restrictive disease. Indications of NIV were acute exacerbations in patients with chronic domiciliary NIV in three patients, hypoxic ARF in six and hypercapnic ARF in five. The diagnoses were pneumonia/atelectasis in seven patients, bilateral extensive pneumonia in three, RSV bronchiolitis in two, apnea in one, and asthma exacerbation in one. Only one patient required intubation for mechanical ventilation, all others improved. The procedures did not have complications. NIV lasted less than three days in 5 patients, 4 to 7 days in four patients and more than 7 days in five. One third of the patients required fiberoptic bronchoscopy for massive or lobar atelectasis and one third remained on domiciliary NIV program. Conclusions: NIV can be useful and safe in children with ARF admitted to a Pediatric Intermediate Care Unit. If strict inclusion protocols are followed, NIV might avoid mechanical ventilation.

Actividad in vitro de 5 antifúngicos contra aislados clínicos y ambientales de pichia anomala / In vitro activity of 5 antifungal against environmental and clinical isolates of pichia anomala

Las infecciones fúngicas han aumentado en el último tiempo, entre ellas, las infecciones por levaduras emergentes, cuyos patrones de sensibilidad no han sido estudiados debido a la inexistencia de patrones de temperatura y medios de cultivo apropiados para realizar test de sensibilidad. El presente trabajo, fue propuesto como un modelo experimental de Pichia anomala, aislada de pacientes con MICs superiores que los aislados ambientales, siendo la anfotericina B el antifúngico con la mejor actividad antifúngica.