Oxidative DNA damage and repair in children exposed to low levels of arsenic in utero and during early childhood: Application of salivary and urinary biomarkers

The present study aimed to assess arsenic exposure and its effect on oxidative DNA damage and repair in young children exposed in utero and continued to live in arsenic-contaminated areas. To address the need for biological specimens that can be acquired with minimal discomfort to children, we used non-invasive urinary and salivary-based assays for assessing arsenic exposure and early biological effects that have potentially serious health implications. Levels of arsenic in nails showed the greatest magnitude of difference between exposed and control groups, followed by arsenic concentrations in saliva and urine. Arsenic levels in saliva showed significant positive correlations with other biomarkers of arsenic exposure, including arsenic accumulation in nails (r = 0.56, P < 0.001) and arsenic concentration in urine (r = 0.50, P < 0.05). Exposed children had a significant reduction in arsenic methylation capacity indicated by decreased primary methylation index and secondary methylation index in both urine and saliva samples. Levels of salivary 8-OHdG in exposed children were significantly higher (~ 4-fold, P < 0.01), whereas levels of urinary 8-OHdG excretion and salivary hOGG1 expression were significantly lower in exposed children (~ 3-fold, P < 0.05), suggesting a defect in hOGG1 that resulted in ineffective cleavage of 8-OHdG. Multiple regression analysis results showed that levels of inorganic arsenic (iAs) in saliva and urine had a significant positive association with salivary 8-OHdG and a significant negative association with salivary hOGG1 expression.     

Serotypes and antimicrobial resistance of Salmonella enterica ssp in central Thailand, 2001-2006

This study was carried out to elucidate the epidemiological trends and antimicrobial susceptibilities against Salmonella serovars among Thai patients and asymptomatic carriers during 2001-2006 in central Thailand. A total of 1,401 human and 260 non-human isolates from various sources were included. The isolates were characterized using serotyping and antimicrobial susceptibility testing. The most common serovars in patients submitting stool samples were S. Weltevreden, S. Stanley, S. Anatum, and S. Rissen. Significantly higher odds ratios were observed in blood samples versus stool sample for S. Choleraesuis, S. Enteritidis, S. Typhimurium, and S. Typhi. Children under five years old suffered the most frequently from gastroenteritis. The patients most commonly infected with an invasive serovar were children and people from 26 to 55 years of age. Antimicrobial susceptibility data revealed that S. Schwarzengrund, S. Choleraesuis, S. Anatum, S. Stanley, S. Rissen, and S. Typhimurium were the most resistant serovars observed. The invasive serovar, S. Choleraesuis was resistant to cefotaxime and norfloxacin. Antimicrobial resistance to cefotaxime, was observed in S. Agona, S. Rissen, S. Typhimurium, S. Anatum, and S. Weltevreden. An alarmingly high frequency of resistance to third generation cephalosporins was observed. We recommend Thai authorities take action in order to prevent spread of resistant S. Choleraesuis and other serovars among animals and humans by enforcing a more strict policy on the use of antimicrobials in food animals.     

Moral competence in nursing practice

This article presents the derivation of moral competence in nursing practice by identifying its attributes founded on Thai culture. In this process moral competence is formed and based on the Thai nursing value system, including personal, social and professional values. It is then defined and its three dimensions (moral perception, judgment and behavior) are also identified. Additionally, eight attributes as indicators of moral competence are identified and selected from three basic values. The eight attributes are loving kindness, compassion, sympathetic joy, equanimity, responsibility, discipline, honesty, and respect for human values, dignity and rights. All attributes are discussed by addressing the three moral dimensions in order to present how to deal with ethical issues in nursing practice. As a summary, a model of moral competence is presented to demonstrate moral competence in nursing practice in Thailand.     

Correlation between mutations in the core and NS5A genes of hepatitis C virus genotypes 1a, 1b, 3a, 3b, 6f and the response to pegylated interferon and ribavirin combination therapy

Several studies have reported correlation between mutations in core and NS5A proteins of hepatitis C virus (HCV) and response to interferon (IFN) therapy. In particular, mutations in NS5A protein have been shown to correlate with responsiveness to IFN treatment of HCV-1b in Japanese patients. This study investigated whether amino acid (aa) mutations in the core and NS5A proteins of HCV-1a, 1b, 3a, 3b and 6f correlated with the response to pegylated interferon (Peg-IFN) plus ribavirin (RBV) therapy in Thai patients. The entire sequences of core and NS5A of HCV from 76 HCV-infected patients were analysed in comparison with corresponding reference sequences. The data revealed that the number of aa mutations in full-length NS5A, its C-terminus, IFN sensitivity-determining region, variable region 3 (V3) and V3 plus flanking region of HCV-1b NS5A protein were significantly higher in responders than in the treatment failure group (P = 0.010, 0.031, 0.046, 0.020 and 0.006, respectively). Similar results were found in a putative protein kinase R binding domain region in HCV-6f NS5A protein (P = 0.022). Moreover, specific aa substitutions in NS5A that appeared to be associated with responders or the treatment failure group were observed at positions 78 and 305 for HCV-1b (P = 0.028), 64 and 52 for HCV-1a (P = 0.033) and 6f (P = 0.045). Nevertheless, analysis of aa sequences of core protein revealed highly conserved sequences among HCV genotypes and no significant differences between the viruses from responders and the treatment failure group. Our findings indicate that mutations in aa residues of NS5A of HCV-1a, 1b and 6f correlated well with responsiveness to Peg-IFN and RBV combination therapy.     

Odontogenic orbital inflammation: clinical and CT findings--initial observations

PURPOSE: To retrospectively review computed tomographic (CT) and clinical findings in patients with odontogenic orbital infection. MATERIALS AND METHODS: Approval from the institutional review board was obtained for chart and scan review, and informed consent was waived for this HIPAA-compliant study. Five patients, two male and three female (median age, 37 years; age range, 13-55 years), who had odontogenic orbital cellulitis underwent clinical evaluation, CT scanning, and treatment. CT findings, including periapical lucency suggesting abscess, sinus opacification, and the route of spread of infection, were analyzed in each patient. Imaging, clinical, and surgical findings, including the initial clinical diagnosis and the presence of a periapical abscess at surgery and at pathologic examination, were compared. RESULTS: Periapical lucency and sinus opacification were seen in all patients. The route of infection spread was through either the premalar soft tissues or the maxillary sinuses. The odontogenic origin of the orbital infection was not clinically suspected in any patients. Correct diagnosis was later made at CT in all patients. Four patients had periapical abscesses at pathologic analysis, and the fifth patient had apical periodontitis at clinical analysis and granuloma at pathologic analysis. Dental surgery was required in each of the five patients for resolution of infection; four patients underwent extraction of the infected tooth, and one patient underwent incision and drainage of a periapical abscess. CONCLUSION: Abnormal periapical lucency, widening of the periodontal ligament space, and the presence of a subperiosteal abscess suggested an odontogenic origin of orbital infection.     

Molecular Characterization of Extended-Spectrum Cephalosporinase-Producing Salmonella enterica Serovar Choleraesuis Isolates from Patients in Thailand and Denmark

The objective of this study was to characterize extended-spectrum cephalosporinase (ESC)-producing isolates of Salmonella enterica serovar Choleraesuis recovered from patients in Thailand and Denmark. Twenty-four blood culture isolates from 22 patients were included in the study, of which 23 isolates were recovered from 21 Thai patients during 2003, 2007, or 2008 and one isolate was recovered from a Danish traveler to Thailand. ESC production was confirmed in 13 out of the 24 isolates by MIC testing. Microarray and plasmid profiling (replicon typing and restriction fragment length polymorphism [RFLP]) were used to characterize the genetic mechanisms of antimicrobial resistance in the 13 ESC-producing isolates. Pulsed-field gel electrophoresis (PFGE) and MIC testing were used to compare the clonality between the 13 ESC-producing isolates and the 11 non-ESC-producing isolates. Based on susceptibility patterns, the ESC-producing isolates were more closely related than non-ESC-producing isolates. Microarray, PCR, plasmid profiling, and replicon typing revealed that the 13 ESC-producing isolates harbored either bla_CMY-2 containing incA/C or bla_CTX-M-14 containing incFIIA, incFrepB, and an unknown replicon located on plasmids ranging in size from 75 to 200 kb. The RFLP and replicon typing clustered the isolates into four distinct groups. PFGE revealed 16 unique patterns and five clusters; each cluster contained two or three of the 24 isolates. The isolate from the Danish patient was indistinguishable from two Thai clinical isolates by PFGE. This study revealed the emergence of the bla_CTX-M-14 gene among several clones of Salmonella serovar Choleraesuis. Numerous plasmids were identified containing up to two different ESC genes and four distinct replicons. A “travel-associated” spread was confirmed. Overall, a high degree of clonal diversity between isolates resistant and susceptible to cephalosporins was observed. The findings represent a serious threat to public health for the Thai people and tourists.Salmonella enterica is a common cause of human gastroenteritis and bacteremia worldwide (18, 31), and a wide variety of animals, particularly food animals, have been identified as reservoirs for non-Typhi Salmonella (11, 22, 23). Although approximately 2,600 serovars of Salmonella enterica have been identified, most human infections are caused by a limited number of serovars, and in general these infections are self-limiting. Some Salmonella serovars, including Salmonella Choleraesuis (swine) and Salmonella Dublin (cattle), which are adapted to a specific animal host, have a propensity to cause extraintestinal infections in humans. Compared to those with other serovars of non-Typhi Salmonella, infections with these serovars are associated with higher rates of bacteremia, meningitis, and mortality (4, 5, 24). For patients with severe salmonellosis, antimicrobial chemotherapy may be life-saving. Due to the increasing prevalence of fluoroquinolone resistance, extended-spectrum cephalosporins are increasingly used for the treatment of Salmonella infections in humans (17, 21, 25) and especially for children, for whom treatment of highly resistant Salmonella infections with fluoroquinolones is not advised, since such treatment has been associated with treatment failures (12, 13, 21). Therefore, these compounds have been designated critically important for human health by the World Health Organization (10).We recently reported that the prevalence of human infections with Salmonella serovar Choleraesuis in Thailand increased from 1.5% (n = 87) in 1994 to 9.2% (n = 190) in 2006 (19). The group of people at highest risk for these infections was those between 6 and 40 years of age in the central region of Thailand (19). A 2007 study of Salmonella serovar Choleraesuis isolates from Thailand observed an increasing resistance to both extended-spectrum cephalosporins (ceftriaxone) and fluoroquinolones. Fifty-four isolates obtained between 2003 and 2005 were tested, of which 30% were found to be resistant to an extended-spectrum cephalosporin (ceftriaxone) (25).To date, only two reports, both from Taiwan, have described mechanisms for extended-spectrum cephalosporin resistance in Salmonella serovar Choleraesuis. The first report was published in 2004 with the discovery of the bla_CMY-2 AmpC β-lactamase gene located on a 140-kb F-like plasmid (6). The following year, the same authors detected bla_CTX-M-3 in a Salmonella serovar Choleraesuis isolate from a patient admitted to a university hospital (30). In 2007, a massive increase of fluoroquinolone- and ceftriaxone-resistant Salmonella serovar Choleraesuis isolates was described in Thailand (25).In Taiwan, the usage of antimicrobials in veterinary medicine and as growth promoters in animal feed may have promoted the emergence of resistance (5). Likewise, in Thailand, the extended-spectrum cephalosporin ceftiofur is used as a growth promoter in swine production (25). However, data on antimicrobial usage in disease prevention and as growth promoters are not accessible in both countries.The objective of the present study was to characterize the mechanisms responsible for the emergence of resistance to extended-spectrum cephalosporins in isolates of Salmonella serovar Choleraesuis recovered from patients in Thailand and Denmark.Additional objectives were to determine the clonality of the isolates resistant and susceptible to cephalosporins (ceftriaxone and cefoxitin) using pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility testing and to find biological evidence of transmission through international travel.