Transposon mutagenesis of atypical enteroaggregative Escherichia coli reveals a hemagglutinin-associated protein that mediates cell adhesion and contributes to the Galleria mellonella virulence.

Twenty-two atypical enteroaggregative Escherichia coli isolates from a previous epidemiological study harboring EAEC virulence genes were examined for their adhesion properties. Nine strains showed a typical aggregative adherence (AA) pattern, while 13 strains showed variant AA, such as AA with lined up cells characteristic of the chain-like adhesion (CLA) and AA mainly to HeLa cells characteristic of the diffuse adherence (DA). The aggregative forming pilus (AFP) genes afpA2 and afpR were detected only in strain Q015B, which exhibited an AA/DA pattern. Using Tn5-based transposon mutagenesis on Q015B strain, we identified a 5517-bp open reading frame (ORF) encoding a predicted 1838-amino-acid polypeptide that is genetically related to a putative filamentous hemagglutinin identified in E. coli strain 7-233-03_S3_C2. Therefore, the ORF was named orfHA. The regions flanking orfHA were sequenced and two ORFs were found; upstream, an ORF that encodes a 603-amino-acid polypeptide with 99% identity to hemolysin secretion/activation proteins of the ShlB/FhaC/HecB family, and downstream, another ORF, which encodes a 632-amino-acid polypeptide with 72% identity to the glycosyltransferase EtpC. An orfHA mutant (Q015BΔorfHA) was constructed from strain Q015B. Q015BΔorfHA strain did not adhere to HeLa cells, whereas Q015BΔ orfHA transformed with a pACYC184 plasmid carrying orfHA restored the AA/DA phenotype of strain Q015B. Furthermore, the Q015ΔorfHA mutant had a marked effect on the ability of strain Q015B to kill the larvae of Galleria mellonella. Our results suggest that the AA/DA pattern of strain Q015B is mediated by a hemagglutinin-associated protein which also contributes to its virulence in the G. mellonella model.

Rasch Analysis of the Global Appraisal of Individual Needs in the City of São Paulo.

INTRODUCTION: Approximately 5% of the global population used an illicit drug in 2013. Regarding licit drugs, alcohol is responsible for the occurrence of approximately 200 diseases, among them depression. In addition to health impairments, alcohol is also implicated in many acts of violence. This study aimed to measure the properties of the Rasch model of the Portuguese version of the Global Appraisal of Individual Needs-Short Screener based on evidence obtained during care for users of alcohol and other drugs. METHOD: To collect the data, 128 interviews were held at the Psychosocial Care Center for Alcohol and Other Drugs in the state capital, during which the scale was applied. RESULTS: The Rasch model revealed that the subscales of the instrument were appropriate, with all items having mean infit and outfit values from 0.5 to 1.5, considered optimal for measurement. There was no evidence of differential performance for gender. Substance use and crime and violence items presented redundancy for severity measures. CONCLUSION: Given the need for validated instruments for use in Brazil, it is encouraging that the Portuguese version of the scale was valid for the Rasch model. The results are consistent with studies using the other American, Brazilian, and Canadian versions of the instrument.

Role of hypothetical protein YicS in the pathogenicity of Avian Pathogenic Escherichia coli in vivo and in vitro.

Avian Pathogenic Escherichia coli (APEC) strains belong to the extra-intestinal pathogenic group of E. coli (ExPEC) that causes colibacillosis in poultry. A variety of putative virulence factors of APEC are recognized as potent causes of pathogenicity, the mechanisms underlying their pathogenicity are still not fully understood. The role of yicS in the virulence of pathogenic E. coli is still unclear. Thus, yicS may be related to biofilm formation, which in some bacteria plays a role in pathogenicity. Therefore, the fact that this gene appears to be under positive selection pressure suggests that yicS may be associated with the pathogenicity of APEC. To better understand the role of yicS protein in APEC biological characteristics and pathogenicity, we deleted yicS in an APEC Swollen Head Syndrome strain (APEC strain SCI-07) and studied its effects by comparing wild type and isogenic mutants through comprehensive in vitro and in vivo assays. We demonstrated that yicS plays a role in pathogenicity of APEC. We suggest that the yicS gene, which encodes an exporter protein, has a significant role in biofilm formation, motility, invasion of CEC-32 and Hep-2 cells and APEC pathogenicity in a day-old chick model.

Genome-Wide Survey of Genes Under Positive Selection in Avian Pathogenic Escherichia coli Strains.

The ability to obtain bacterial genomes from the same host has allowed for comparative studies that help in the understanding of the molecular evolution of specific pathotypes. Avian pathogenic Escherichia coli (APEC) is a group of extraintestinal strains responsible for causing colibacillosis in birds. APEC is also suggested to possess a role as a zoonotic agent. Despite its importance, APEC pathogenesis still has several cryptic pathogenic processes that need to be better understood. In this work, a genome-wide survey of eight APEC strains for genes with evidence of recombination revealed that ∼14% of the homologous groups evaluated present signs of recombination. Enrichment analyses revealed that nine Gene Ontology (GO) terms were significantly more represented in recombinant genes. Among these GO terms, several were noted to be ATP-related categories. The search for positive selection in these APEC genomes revealed 32 groups of homologous genes with evidence of positive selection. Among these groups, we found several related to cell metabolism, as well as several uncharacterized genes, beyond the well-known virulence factors ompC, lamB, waaW, waaL, and fliC. A GO term enrichment test showed a prevalence of terms related to bacterial cell contact with the external environment (e.g., viral entry into host cell, detection of virus, pore complex, bacterial-type flagellum filament C, and porin activity). Finally, the genes with evidence of positive selection were retrieved from genomes of non-APEC strains and tested as were done for APEC strains. The result revealed that none of the groups of genes presented evidence of positive selection, confirming that the analysis was effective in inferring positive selection for APEC and not for E. coli in general, which means that the study of the genes with evidence of positive selection identified in this study can contribute for the better understanding of APEC pathogenesis processes.

Variants of astA gene among extra-intestinal Escherichia coli of human and avian origin.

Many Escherichia coli strains harbour astA, which is the gene encoding the enteroaggregative E. coli heat-stable enterotoxin (EAST1). This gene is embedded in a putative transposase (ORF1) and presents polymorphism in diarrheagenic strains. Although astA and orf1 are detected in extraintestinal strains, little is known about polymorphism and differential gene transcription in this pathotype. In the present work, extraintestinal E. coli from humans (ExPEC - Extraintestinal Pathogenic E. coli) and poultry (APEC - Avian Pathogenic E. coli) were assayed to verify the presence of astA/orf1 and possible polymorphisms in these genes. Three astA/orf1 patterns were detected via Sanger sequencing. Pattern 1 was novel and represented an astA pseudogene. Pattern 2 and pattern 3 presented distinct amino acids within the reading frame encoding astA and were identical to the sequences found in EAEC 17-2 and EAEC 042, respectively. Regarding the frame encoding ORF1, all mutations detected in the three patterns were neutral. The transcripts of astA/orf1 in vitro were underregulated in strains possessing the pattern 1 sequence. The results demonstrate that the same astA sequences may be detected in diarrheagenic and extra-intestinal E. coli. However, extraintestinal isolates may also present an astA pseudogene that has not been reported in diarrheagenic E. coli.

Internal Consistency and Convergent Validity of the Portuguese Versions of the Global Appraisal of Individual Needs-Initial and Short Screener: Validity of the Portuguese GAIN-I and SS.

The goal of this article is to present evidence on the internal consistency and convergent validity of the Brazilian Portuguese versions of the Global Appraisal of Individual Needs-"Initial" and "Short Screener" versions. METHODS: One hundred sixty-eight individuals from an inpatient service and/or a community-based outpatient service located in São Paulo were interviewed using the Brazilian Portuguese versions of the instruments. The internal consistency of the instruments scales was computed, along with evidence for the convergent validity between corresponding subscales of the Initial and Short Screener instruments. RESULTS: Cronbach's alpha values for both instruments' total scale scores were greater than .7. The Short Screener scales showed strong-to-moderate correlations with corresponding subscales of the Initial. The General Individual Severity Scale from the Initial and Total Disorder Screener from the Short Screener have convergent validity with each other (ρ = 0.801). CONCLUSIONS: The Brazilian Portuguese instrument scales showed evidence for internal consistency and convergent validity performing similarly to the American English versions.

The virulence factor ychO has a pleiotropic action in an Avian Pathogenic Escherichia coli (APEC) strain.

BACKGROUND: Avian pathogenic Escherichia coli strains cause extraintestinal diseases in birds, leading to substantial economic losses to the poultry industry worldwide. Bacteria that invade cells can overcome the host humoral immune response, resulting in a higher pathogenicity potential. Invasins are members of a large family of outer membrane proteins that allow pathogen invasion into host cells by interacting with specific receptors on the cell surface. RESULTS: An in silico analysis of the genome of a septicemic APEC strain (SEPT362) demonstrated the presence of a putative invasin homologous to the ychO gene from E. coli str. K-12 substr. MG1655. In vitro and in vivo assays comparing a mutant strain carrying a null mutation of this gene, a complemented strain, and its counterpart wild-type strain showed that ychO plays a role in the pathogenicity of APEC strain SEPT362. In vitro assays demonstrated that the mutant strain exhibited significant decreases in bacterial adhesiveness and invasiveness in chicken cells and biofilm formation. In vivo assay indicated a decrease in pathogenicity of the mutant strain. Moreover, transcriptome analysis demonstrated that the ychO deletion affected the expression of 426 genes. Among the altered genes, 93.66% were downregulated in the mutant, including membrane proteins and metabolism genes. CONCLUSION: The results led us to propose that gene ychO contributes to the pathogenicity of APEC strain SEPT362 influencing, in a pleiotropic manner, many biological characteristics, such as adhesion and invasion of in vitro cultured cells, biofilm formation and motility, which could be due to the possible membrane location of this protein. All of these results suggest that the absence of gene ychO would influence the virulence of the APEC strain herein studied.

Complete Genomic Sequence of an Avian Pathogenic Escherichia coli Strain of Serotype O7:HNT.

Avian pathogenic Escherichia coli (APEC) is associated with colibacillosis in poultry. Here, we present the first complete sequence of an APEC strain of the O7:HNT serotype and ST73 sequence type, isolated from a broiler with cellulitis. Complete genomes of APEC with distinct genetic backgrounds may be useful for comparative analysis.

Fimbria-Encoding Gene yadC Has a Pleiotropic Effect on Several Biological Characteristics and Plays a Role in Avian Pathogenic Escherichia coli Pathogenicity.

The extraintestinal pathogen termed avian pathogenic Escherichia coli (APEC) is known to cause colibacillosis in chickens. The molecular basis of APEC pathogenesis is not fully elucidated yet. In this work, we deleted a component of the Yad gene cluster (yadC) in order to understand the role of Yad in the pathogenicity of the APEC strain SCI-07. In vitro, the transcription level of yadC was upregulated at 41°C and downregulated at 22°C. The yadC expression in vivo was more pronounced in lungs than in spleen, suggesting a role in the early steps of the infection. Chicks infected with the wild-type and mutant strains presented, respectively, 80% and 50% mortality rates. The ΔyadC strain presented a slightly decreased ability to adhere to HeLa cells with or without the d-mannose analog compared with the wild type. Real-time PCR (RT-PCR) assays showed that fimH was downregulated (P < 0.05) and csgA and ecpA were slightly upregulated in the mutant strain, showing that yadC modulates expression of other fimbriae. Bacterial internalization studies showed that the ΔyadC strain had a lower number of intracellular bacteria recovered from Hep-2 cells and HD11 cells than the wild-type strain (P < 0.05). Motility assays in soft agar demonstrated that the ΔyadC strain was less motile than the wild type (P < 0.01). Curiously, flagellum-associated genes were not dramatically downregulated in the ΔyadC strain. Taken together, the results show that the fimbrial adhesin Yad contributes to the pathogenicity and modulates different biological characteristics of the APEC strain SCI-07.

Genetic analysis of enteropathogenic Escherichia coli (EPEC) adherence factor (EAF) plasmid reveals a new deletion within the EAF probe sequence among O119 typical EPEC strains.

BACKGROUND: Enteropathogenic Escherichia coli (EPEC) are classified into typical and atypical strains based on the presence of the E. coli adherence factor (EAF) plasmid. The EAF plasmid contains the bfp (bundle-forming pilus) operon and the perABC (plasmid encoded regulator) gene cluster. A 1-kb cryptic region of EAF plasmid has been widely used as a genetic probe for EPEC detection. However, some EPEC strains may harbor an EAF plasmid lacking the EAF probe sequence, which makes the differentiation between typical and atypical a complex task. In this study, we report the genetic analysis of the EAF plasmid-encoded genes in a collection of EPEC clinical isolates. METHODS: A total of 222 EPEC clinical isolates, which were previously classified as typical (n=70) or atypical (n=152) by EAF probe reactivity, were screened for the presence of different EAF sequences by PCR and DNA hybridization. RESULTS: All typical strains possessed intact bfpA and perA genes, and most of them were positive in the PCR for EAF probe sequence. However, a subset of 30 typical strains, 22 of which belonged to O119 serogroup, presented a 1652 pb deletion in the region between 1093-bp downstream perC and 616-bp of the EAF fragment. The bfpA, bfpG, and per genes were found in all typical strains. In addition, 32 (21%) atypical strains presented the perA gene, and 20 (13.2%) also presented the bfpA gene. Among the 32 strains, 16 belonged to the O119:H2, O119:HND, and ONT:HND serotypes. All 32 atypical strains contained perA mutation frameshifts and possessed an IS1294 element upstream of the per operon as detected by PCR followed by restriction fragment length polymorphism (RFLP) typing and multiplex PCR. Among the 20 bfpA probe-positive strains, eight O119 strains possessed deletion in the bfp operon at the 3'end of bfpA due to an IS66 element. CONCLUSION: Our data show that typical O119 strains may contain a deletion within the EAF probe sequence not previously reported. This new finding suggests that care should be taken when using the previously described EAF PCR assay in epidemiological studies for the detection of typical O119 strains. In addition, we were able to confirm that some atypical strains carry vestiges of the EAF plasmid.

Rasch model of the GAIN substance problem scale among inpatient and outpatient clients in the city of São Paulo, Brazil.

INTRODUCTION: This study used the Rasch model to evaluate the psychometric properties of the Portuguese version of the Substance Problem Scale (SPS) of the "Global Appraisal of Individual Needs - Initial" for use in Brazil. The SPS measures alcohol and drug problem severity within a DSM-IV-TR framework. The goal of the Rasch analysis was to assess scale dimensionality, item severity, and differential item functioning (DIF). METHODS: Data was collected from 40 inpatients and 70 outpatients in São Paulo, Brazil. The Rasch model fit and DIF by gender and level of care were examined. RESULTS: The SPS fit the Rasch model, with no items distorting the measure. Only three of the sixteen items performed differently between men and women and three performed differently by level of care. CONCLUSIONS: The results were compatible with those from Rasch analyses of the American English and Canadian English versions of the scale. The Portuguese version of the SPS is, thus, valid for use in Brazil, both with men and women in inpatient and outpatient programs.

•Rasch analysis of the Portuguese version of the Substance Problem Scale performed•This scale has performance similar to Canadian and American versions.•None of the scale items distort the measurement.•Further differential item functioning analysis with larger sample needed.

Influence of the major nitrite transporter NirC on the virulence of a Swollen Head Syndrome avian pathogenic E. coli (APEC) strain.

Avian Pathogenic Escherichia coli (APEC) strains are extra-intestinal E. coli that infect poultry and cause diseases. Nitrite is a central branch-point in bacterial nitrogen metabolism and is used as a cytotoxin by macrophages. Unlike nitric oxide (NO), nitrite cannot diffuse across bacterial membrane cells. The NirC protein acts as a specific channel to facilitate the transport of nitrite into Salmonella and E. coli cells for nitrogen metabolism and cytoplasmic detoxification. NirC is also required for the pathogenicity of Salmonella by downregulating the production of NO by the host macrophages. Based on an in vitro microarray that revealed the overexpression of the nirC gene in APEC strain SCI-07, we constructed a nirC-deficient SCI-07 strain (ΔnirC) and evaluated its virulence potential using in vivo and in vitro assays. The final cumulative mortalities caused by mutant and wild-type (WT) were similar; while the ΔnirC caused a gradual increase in the mortality rate during the seven days recorded, the WT caused mortality up to 24h post-infection (hpi). Counts of the ΔnirC cells in the spleen, lung and liver were higher than those of the WT after 48 hpi but similar at 24 hpi. Although similar number of ΔnirC and WT cells was observed in macrophages at 3 hpi, there was higher number of ΔnirC cells at 16 hpi. The cell adhesion ability of the ΔnirC strain was about half the WT level in the presence and absence of alpha-D-mannopyranoside. These results indicate that the nirC gene influences the pathogenicity of SCI-07 strain.

Overlapped sequence types (STs) and serogroups of avian pathogenic (APEC) and human extra-intestinal pathogenic (ExPEC) Escherichia coli isolated in Brazil.

Avian pathogenic Escherichia coli (APEC) strains belong to a category that is associated with colibacillosis, a serious illness in the poultry industry worldwide. Additionally, some APEC groups have recently been described as potential zoonotic agents. In this work, we compared APEC strains with extraintestinal pathogenic E. coli (ExPEC) strains isolated from clinical cases of humans with extra-intestinal diseases such as urinary tract infections (UTI) and bacteremia. PCR results showed that genes usually found in the ColV plasmid (tsh, iucA, iss, and hlyF) were associated with APEC strains while fyuA, irp-2, fepC sitDchrom, fimH, crl, csgA, afa, iha, sat, hlyA, hra, cnf1, kpsMTII, clpVSakai and malX were associated with human ExPEC. Both categories shared nine serogroups (O2, O6, O7, O8, O11, O19, O25, O73 and O153) and seven sequence types (ST10, ST88, ST93, ST117, ST131, ST155, ST359, ST648 and ST1011). Interestingly, ST95, which is associated with the zoonotic potential of APEC and is spread in avian E. coli of North America and Europe, was not detected among 76 APEC strains. When the strains were clustered based on the presence of virulence genes, most ExPEC strains (71.7%) were contained in one cluster while most APEC strains (63.2%) segregated to another. In general, the strains showed distinct genetic and fingerprint patterns, but avian and human strains of ST359, or ST23 clonal complex (CC), presented more than 70% of similarity by PFGE. The results demonstrate that some "zoonotic-related" STs (ST117, ST131, ST10CC, ST23CC) are present in Brazil. Also, the presence of moderate fingerprint similarities between ST359 E. coli of avian and human origin indicates that strains of this ST are candidates for having zoonotic potential.

Avian extraintestinal Escherichia coli exhibits enterotoxigenic-like activity in the in vivo rabbit ligated ileal loop assay.

Avian pathogenic Escherichia coli (APEC) strains harbor a number of virulence genes and cause extraintestinal diseases, such as septicemia, swollen-head syndrome, salpingitis, and omphalitis in poultry. APEC strains are not known to cause intestinal diseases. Herein, for the first time, it is reported that APEC strains were able to induce an enterotoxigenic-like effect in rabbit ligated ileal loops. Strain SEPT362 caused cell detachment of the intestinal villi, which also showed a flattened and wilted appearance, but the integrity of the tight junctions was maintained. Additionally, this strain did not adhere to enterocytes in vivo, although adhesin encoding genes ( fimH, csgA, lpfA2-3, and ECP) were present while other lpfA types, sfa, afa, papC, and ral genes were not. This enterotoxigenic-like activity was conserved after thermal treatment of the supernatant at 65°C but not at 100°C. Moreover, experiments based on filtering with different molecular weight cut-off (MWCO) pore sizes demonstrated that the component associated with the observed biological effect has a molecular weight >100 kDa. Blast search and polymerase chain reaction assays for known E. coli virulence factors showed that strain SEPT362 harbors the gene encoding for the toxin EAST-1 and the serine protease autotransporter (SPATE) Tsh, but is negative for genes encoding for the toxins LT-I, STh, STp, Stx1, Stx2, CNF-1, CNF-2, CDT and the SPATEs Sat, Pic, Vat, SigA, SepA, EatA, EspP, or EspC. A cloned copy of the tsh gene in E. coli K-12 was also tested and was shown to have an enterotoxic effect. These results suggest that APEC might induce fluid accumulation in the rabbit gut. The Tsh autotransporter seems to be one of the factors associated with this phenotype.

In silico phylogenetic and virulence gene profile analyses of avian pathogenic Escherichia coli genome sequences / Análises in silico da filogenia e do perfil de genes associados à virulência, dos genomas de linhagens de Escherichia coli de origem aviária

Avian pathogenic Escherichia coli (APEC) infections are responsible for significant losses in the poultry industry worldwide. A zoonotic risk has been attributed to APEC strains because they present similarities to extraintestinal pathogenic E. coli (ExPEC) associated with illness in humans, mainly urinary tract infections and neonatal meningitis. Here, we present in silico analyses with pathogenic E. coli genome sequences, including recently available APEC genomes. The phylogenetic tree, based on multi-locus sequence typing (MLST) of seven housekeeping genes, revealed high diversity in the allelic composition. Nevertheless, despite this diversity, the phylogenetic tree was able to cluster the different pathotypes together. An in silico virulence gene profile was also determined for each of these strains, through the presence or absence of 83 well-known virulence genes/traits described in pathogenic E. coli strains. The MLST phylogeny and the virulence gene profiles demonstrated a certain genetic similarity between Brazilian APEC strains, APEC isolated in the United States, UPEC (uropathogenic E. coli) and diarrheagenic strains isolated from humans. This correlation corroborates and reinforces the zoonotic potential hypothesis proposed to APEC.

As infecções causadas por linhagens de Escherichia coli de origem aviária (APEC) são responsáveis por perdas significativas na indústria avícola em todo mundo. Risco zoonótico tem sido atribuído às linhagens APEC, devido às semelhanças existentes entre elas e linhagens de E. coli patogênicas extraintestinais (ExPEC) de origem humana, causadoras de infecções no trato urinário e meningite neonatal. Neste trabalho, apresentamos os resultados de análises in silico feitas a partir dos genomas de linhagens patogênicas de E. coli, incluindo genomas recentemente obtidos de linhagens APEC. Uma árvore filogenética foi obtida, com base na tipagem de sequência multilocus (MLST) de sete genes essenciais, revelando alta diversidade na composição de alelos, mas ainda assim possibilitando o agrupamento dos diferentes patótipos. Foi determinado também, para cada linhagem, o perfil gênico, por meio da presença ou ausência de 83 genes associados à virulência. A árvore filogenética e o perfil gênico demonstraram que existem semelhanças genéticas entre cepas APEC brasileiras, APEC isolada nos Estados Unidos, UPEC (uropathogenic E. coli) e linhagens produtoras de diarreia em humanos. Essa correlação corrobora e reforça a hipótese de que linhagens APEC apresentam potencial risco zoonótico.

Genome Sequences of Avian Pathogenic Escherichia coli Strains Isolated from Brazilian Commercial Poultry.

Avian pathogenic Escherichia coli (APEC) infections are responsible for significant losses in the poultry industry worldwide. The disease might present as different local infections or as septicemia. Here, we present the draft genome sequences of three Brazilian APEC strains isolated from different kinds of infections. The availability of these APEC genome sequences is important for gaining a thorough understanding of the genomic features of E. coli, particularly those of this pathotype.

Draft genome of a Brazilian avian-pathogenic Escherichia coli strain and in silico characterization of virulence-related genes.

Avian-pathogenic Escherichia coli (APEC) strains cause extraintestinal diseases in avian species. Here, we present the draft genome of an APEC strain (SCI-07) from Brazil that was isolated from skin lesions (gelatinous edema) on the head and periorbital tissues of a laying hen with swollen head syndrome.

Proinflammatory cytokines during the initial phase of oral mucositis in patients with acute lymphoblastic leukaemia.

OBJECTIVE: The aim of the study was to compare the production of proinflammatory cytokines during the initial phase of mucositis in patients with acute lymphoblastic leukaemia. METHODS: A randomized, controlled clinical trial was carried out. Cytokine levels were determined in blood and saliva using ELISA, three times after the administration of methotrexate and only once in the control group. RESULTS: Comparison of the results showed significant differences for IL-6 and TNF-α in blood and IL-6 in saliva. CONCLUSION: It would seem that 96 h is an ideal time for determining the parameters evaluated both in blood and in saliva.

Parámetros inflamatorios en saliva y sangre en niños y adolescentes sanos / Inflammatory parameters in saliva and blood from healthy children and adolescents

En la actualidad se ha mostrado interés en el empleo de la saliva para ser utilizada como una alternativa de diagnóstico, predicción y progresión de diversas enfermedades con relación a otros fluidos corporales. Los objetivos trazados para la realización de este trabajo fueron: correlacionar las concentraciones en saliva y sangre de IL-1, IL-6, TNF-a, sustancias reactivas al ácido tiobarbitúrico y O2- de niños y adolescentes sistémicamente sanos. Se realizó un estudio de corte transversal en 23 niños y adolescentes sanos, entre 4 y 17 años de edad. Se les realizaron evaluaciones clínicas para determinar las condiciones bucales y estudios inmunológicos con el propósito de identificar los niveles de citosinas, a través del ensayo inmunoenzimático indirecto, el O2- por método citoquímico y las sustancias reactivas al ácido tiobarbitúrico, a través del ensayo colorimétrico. Hubo diferencia significativa entre las muestras de saliva y las de sangre periférica respecto a las citosinas y sustancias reactivas al ácido tiobarbitúrico estudiadas. Los resultados fueron: IL-1 en sangre= 1,646 ± 0,13 pg/mL y de IL-1 en saliva= 552,36 ± 75,7 pg/mL; IL-6 en sangre= 3,506 ± 1,85 pg/mL, e IL-6 en saliva= 26,89 ± 9,97 pg/mL. Al analizar el TNF-a en sangre fue de 12,91 ± 3,05 pg/mL y en saliva= 43,56 ± 6,44 pg/mL, las sustancias reactivas al ácido tiobarbitúrico en sangre= 9,46 ± 3,26 nmol/mL y en saliva= 1,26 ± 0,03 nmol/mL. No se observó correlación estadísticamente significativa entre las muestras de sangre y saliva para los valores de IL-1, IL-6 y sustancias reactivas al ácido tiobarbitúrico. En cuanto al TNF-a se evidenció una correlación significativa, r s= 0,78. No se evidenciaron células positivas para el O2- en las muestras estudiadas. Los resultados del análisis de correlación obtenido entre las muestras salivales y séricas, no aportaron evidencias suficientes para sugerir que la saliva pueda ser utilizada como fluido corporal que permita sustituir la determinación sérica de IL-1, IL-6 y sustancias reactivas al ácido tiobarbitúrico. En cuanto al TNF-a se evidenció una correlación significativa, lo cual podría plantear la posible sustitución de muestras séricas por salivales(AU)

At present times, there is interest in the use of saliva as a diagnosis, prediction and progression alternative of different pathologies in relation to the body fluids. To correlate the concentrations of IL-1, IL-6, TNF-a, substances reactive to thiobarbituric acid (RSTBA) and O2- in the saliva and blood of systematically healthy children and adolescents. A cross-sectional study was performed in 23 healthy children and adolescents aged from 4 to 17 underwent to clinical tests to demonstrate the oral conditions and immunological to identify the cytokine levels and the RSTBAs by colorimetry trial. There was a significant difference in saliva samples compared to that of peripheral blood in study cytokines and RSTBAs: IL-1 (blood: 1.646 ± 0.13 pg/mL, saliva: 552.36 ± 75.7 pg/mL; IL-6 (blood: 3.506 ± 1.85 pg/mL, saliva: 26.89 ± 9.97 pg/mL: TNF-a (blood: 12.91 ± 3.05 pg/mL, saliva: 43.56 ± 6.44 pg/mL), RSTBA (blood: 9.46 ± 3.26 nmol/mL, saliva: 1.26 ± 0.03 nmol/mL). There was not a statistically significant difference among blood and saliva samples for IL-1, IL-6 and RSTBA values. As regards TNF-a it was demonstrated a significant correlation, r s= 0.78. There was not evidence of cells positive to O2 in study samples. Results of correlation analysis obtained among the saliva and serum samples not offer evidences that saliva may be used as body fluid allows substituting the serum determination of IL-1, IL-6 and RSTBA. In the case of the TNF-a, there was a significant correlation, which could to propose the possible substitution of serum samples for the salivary ones(AU)

Evaluación del comportamiento clínico de dos cementos de óxido de cinc mejorados y su relación con el pH del medio bucal / Evalutation of the clinical behavior of two improved zinc-oxide cements and their relationship with oral environment pH

Esta investigación evaluó el comportamiento clínico de dos cementos de óxido de cinc mejorados, fórmulas experimentales fabricadas en Venezuela: un polímero orgánico de metacrilato de metilo sin tratamiento previo del polvo y un polímero orgánico de poliestireno con tratamiento previo del polvo con ácido nítrico. Se utilizó como cemento control el IRM (patentado comercial de la casa Caulk), dada su eficacia suficientemente probada. Las fórmulas experimentales y el control fueron colocados en 150 cavidades clase I de molares primarios, y evaluados 6 meses después de su colocación, de acuerdo a criterios clínicos estandarizados de Ryge: forma anatómica, adaptación marginal e incidencia de caries. Posteriormente, se relacionaron estos hallazgos con los niveles de pH encontrados en el medio bucal. El estudio se calificó de tipo experimental, particularmente como ensayo clínico de tipo ciego sencillo. La muestra estuvo conformada por 150 unidades dentarias distribuidas en 50 niños de ambos sexos, escolarizados, en edades comprendidas entre 5 y 8 años. Según los resultados obtenidos, no se encontraron diferencias estadísticamente significativas entre el comportamiento clínico de las fórmulas experimentales y del cemento control en cuanto a su forma anatómica, adaptación marginal e incidencia de caries. Al relacionar comportamiento clínico de los cementos con el pH del medio bucal, se encontraron diferencias estadísticamente significativas. Se concluye que los tres cementos mostraban hasta el momento las mismas propiedades en cuanto a su comportamiento clínico