The effects of enhanced formaldehyde clearance in a gross anatomy laboratory by floor plan redesign and dissection table adjustment.

Formaldehyde has carcinogenic properties. It is associated with nasopharyngeal cancer and causes irritation of the eyes, nose, throat, and respiratory system. Formaldehyde exposure is a significant health concern for those participating in the gross anatomy laboratory, but no learning method can substitute cadaver dissection. We performed a formaldehyde level study in 2018, which found that most of the breathing zone (S-level) and environment (R-level) formaldehyde levels during laboratory sessions at the Faculty of Medicine Siriraj Hospital exceeded international ceiling standards. In the academic year 2019, we adapted the engineering rationale of the NIOSH hierarchy of controls to facilitate formaldehyde clearance by opening the dissection table covers and increasing the area per dissection table, then measured formaldehyde ceiling levels by formaldehyde detector tube with a gas-piston hand pump during (1) body wall, (2) upper limb, (3) head-neck, (4) thorax, (5) spinal cord removal, (6) lower limb, (7) abdomen, and (8) organs of special senses dissection sessions and comparing the results with the 2018 study. The perineum region data were excluded from analyses due to the laboratory closure in 2019 from the COVID-19 outbreak. There were statistically significant differences between the 2018 and 2019 S-levels (p < 0.001) and R-levels (p < 0.001). The mean S-level decreased by 64.18% from 1.34 ± 0.71 to 0.48 ± 0.26 ppm, and the mean R-level decreased by 70.18% from 0.57 ± 0.27 to 0.17 ± 0.09 ppm. The highest formaldehyde level in 2019 was the S-level in the body wall region (1.04 ± 0.3 ppm), followed by the S-level in the abdomen region (0.56 ± 0.08 ppm) and the spinal cord removal region (0.51 ± 0.29 ppm). All 2019 formaldehyde levels passed the OSHA 15-min STEL standard (2 ppm). The R-level in the special sense region (0.06 ± 0.02 ppm) passed the NIOSH 15-min ceiling limit (0.1 ppm). Three levels for 2019 were very close: the R-level in the head-neck region (0.11 ± 0.08 ppm), the abdomen region (0.11 ± 0.08), the body wall region (0.14 ± 0.12 ppm), and the S-level in the special sense region (0.12 ± 0.04 ppm). In summary, extensive analysis and removal of factors impeding formaldehyde clearance can improve the general ventilation system and achieve the OSHA 15-min STEL standard.

One academic year laboratory and student breathing zone formaldehyde level, measured by gas-piston hand pump at gross anatomy laboratory, Siriraj Hospital, Thailand.

This study used a formaldehyde detector tube with a gas-piston hand pump to assess ceiling levels of student breathing zone and gross laboratory environment across the 2018 academic year. The room dimension was 28.6 × 55.48 × 5.5 m. It contained 90 cadavers, each placed on a hinged cover table. We measured before and during nine body region dissections. There was a significant difference (p < 0.01) between student exposure and laboratory environment levels. The highest level was student exposure during body wall dissection (2.7 ppm), the first laboratory; students may accidentally enter body cavities. The latter two were in abdominal (1.85 ppm) and lower limb dissections (1.49 ppm). The three highest environment levels were in different regions; spinal cord removal (1.13 ppm), lower limb (0.72 ppm), and thorax (0.71 ppm) dissection. Only the perineum environment level (0.09 ppm) was below the NIOSH ceiling level (0.1 ppm), which may result from the table covers that had been opened for 2 weeks before measurement. This study finding signified the importance of student personal exposure monitoring and encouraged the academic year measurement. Because each laboratory has unique factors, those affect formaldehyde levels; dissection steps, dissection table design, cadaver storage protocol, and heating-ventilation-air conditioning system performance, for instance.

Novel Mutation of the TINF2 Gene in a Patient with Dyskeratosis Congenita.

Dyskeratosis congenita (DKC) is a rare inherited disease that is characterized by abnormal skin pigmentation, nail dystrophy and mucosal leukoplakia. DKC is caused by an abnormality in a component of the telomerase and shelterin complexes. TINF2 encodes a protein in the shelterin complex and TERC encodes a component of the telomerase complex. Mutations of both genes have been associated with DKC. This study examined mutations in TINF2.

Association of CTXN3-SLC12A2 polymorphisms and schizophrenia in a Thai population.

BACKGROUND: A genome-wide association study (GWAS) combined with brain imaging as a quantitative trait analysis revealed that the SNPs near CTXN3-SLC12A2 region were related to forebrain development and stress response which involved in schizophrenia. In the present study, the SNPs in this region were analyzed for association with schizophrenia in a Thai population. METHODS: A total of 115 schizophrenia and 173 unrelated normal controls with mean age of 37.87 ± 11.8 and 42.81 ± 6.0 years, respectively, were included in this study. Genotyping was performed using polymerase chain reaction and high-resolution melting (HRM) analysis. The difference in genotype distribution between patient and control was assessed by Chi-square test of the SPSS software. RESULTS: We found a significant association between the GWAS-discovered SNP, rs245178, with the risk of schizophrenia in the Thai population [P = 0.006, odds ratio for the minor G allele: 0.62(0.46-0.83)]. Additionally, another potential SNP, rs698172, which was in moderate linkage disequilibrium with rs245178, also showed strong association with schizophrenia [P = 0.003, odds ratio for minor T allele: 0.61(0.46-0.82)]. This association remained significant at 5% level after the Bonferroni correction for multiple testing. CONCLUSIONS: This study shows that two SNPs in intergenic of the CTXN3 and SLC12A2 genes, rs245178 and rs698172, are associated with risk of schizophrenia in Thai population. Further study is required for clarification the role of genetic variation around these SNPs in expression pattern of the CTXN3 and SLC12A2 genes, which may be involved in schizophrenia pathogenesis.

OPCML gene as a schizophrenia susceptibility locus in Thai population.

Opioid-binding protein/cell adhesion molecule (OPCML) gene has been recently identified as a susceptibility gene for schizophrenia in Europeans. This study aims to investigate the association between single nucleotide polymorphisms (SNPs) in the OPCML gene and risk of schizophrenia in a Thai population. DNA samples of 115 schizophrenia patients and 173 normal controls were genotyped using high-resolution melting analysis and analyzed by chi-square test of SPSS software. We observed a strong association between an intronic SNP of the OPCML gene (rs1784519) and the risk of schizophrenia in the Thai population [P = 0.00036; odds ratio for the minor A allele, 2.11(1.57-2.84)]. The previously discovered SNP associated with schizophrenia in Europeans, rs3016384, also showed significant association with schizophrenia in the Thai population [P = 0.01; odds ratio of the minor T allele, 0.59 (0.44-0.79)]. Therefore, the OPCML gene is considered to be a schizophrenia-susceptible gene in the Thai population.

Multiplex real-time PCR and high-resolution melting analysis for detection of white spot syndrome virus, yellow-head virus, and Penaeus monodon densovirus in penaeid shrimp.

A multiplex real-time PCR and high-resolution melting (HRM) analysis was developed to detect simultaneously three of the major viruses of penaeid shrimp including white spot syndrome virus (WSSV), yellow-head virus (YHV), and Penaeus monodon densovirus (PmDNV). Plasmids containing DNA/cDNA fragments of WSSV and YHV, and genomic DNAs of PmDNV and normal shrimp were used to test sensitivity of the procedure. Without the need of any probe, the products were identified by HRM analysis after real-time PCR amplification using three sets of viral specific primers. The results showed DNA melting curves that were specific for individual virus. No positive result was detected with nucleic acids from shrimp, Penaeus monodon nucleopolyhedrovirus (PemoNPV), Penaeus stylirostris densovirus (PstDNV), or Taura syndrome virus (TSV). The detection limit for PmDNV, YHV and WSSV DNAs were 40fg, 50fg, and 500fg, respectively, which was 10 times more sensitive than multiplex real-time PCR analyzed by agarose gel electrophoresis. In viral nucleic acid mixtures, HRM analysis clearly identified each virus in dual and triple infection. To test the capability to use this method in field, forty-one of field samples were examined by HRM analysis in comparison with agarose gel electrophoresis. For HRM analysis, 11 (26.83%), 9 (21.95%), and 4 (9.76%) were infected with WSSV, PmDNV, and YHV, respectively. Agarose gel electrophoresis detected lesser number of PmDNV infection which may due to the limit of sensitivity. No multiple infection was found in these samples. This method provides a rapid, sensitive, specific, and simultaneous detection of three major viruses making it as a useful tool for diagnosis and epidemiological studies of these viruses in shrimp and carriers.

Six novel ATP7B mutations in Thai patients with Wilson disease.

WD is an autosomal recessive disorder of copper transport resulting in excessive copper deposition in the liver and brain. It is caused by defects of ATP7B encoding a copper transporting P-type ATPase. To identify the mutations in ATP7B in Thai patients with WD, DHPLC analysis was applied to detect mutations and polymorphisms of the entire ATP7B gene in 19 Thai patients with WD. Mutations in ATP7B were identified in 14 of 19 patients: 2 homozygotes, 8 compound heterozygotes and 4 heterozygotes. Eighteen mutations distributed throughout the entire coding region of ATP7B gene including 11 missense, 3 nonsense, 1 splice-site, 1 deletion and 2 insertions. Of 18 different mutations identified, 6 were found to be novel. Twelve single nucleotide polymorphisms (SNPs) were also identified and two SNPs have not yet previously been reported. Segregation analysis using DHPLC analysis showed mutation transmission patterns within each family of Thai patients with WD. Mutations in ATP7B in Thai patients with WD are worth adding into the public database for genetic epidemiology and population genetics.