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Displaying publications 21 - 24 of 24 in total

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Performance and diagnostic accuracy of scoring systems in adult patients with suspected appendicitis

Gan DEY, Nik Mahmood NRK, Chuah JA, Hayati F

Langenbecks Arch Surg, 2023 Jul 06;408(1):267.
PMID: 37410251 DOI: 10.1007/s00423-023-02991-5

BACKGROUND: This study aims to determine the most accurate appendicitis scoring system and optimal cut-off points for each scoring system.
METHODS: This single-centred prospective cohort study was conducted from January-to-June 2021, involving all patients admitted on suspicion of appendicitis. All patients were scored according to the Alvarado score, Appendicitis Inflammatory Response (AIR) score, Raja Isteri Pengiran Anak Saleha (RIPASA) score and Adult Appendicitis score (AAS). The final diagnosis for each patient was recorded. Sensitivity and specificity were calculated for each system. Receiver operating characteristic (ROC) curve was constructed for each scoring system, and the area under the curve (AUC) was calculated. Optimal cut-off scores were calculated using Youden's Index.
RESULTS: A total of 245 patients were recruited with 198 (80.8%) patients underwent surgery. RIPASA score had higher sensitivity and specificity than other scoring systems without being statistically significant (sensitivity 72.7%, specificity 62.3%, optimal score 8.5, AUC 0.724), followed by the AAS (sensitivity 60.2%, specificity 75.4%, optimal score 14, AUC 0.719), AIR score (sensitivity 76.7%, specificity 52.2%, optimal score 5, AUC 0.688) and Alvarado score (sensitivity 69.9%, specificity 62.3%, optimal score 5, AUC 0.681). Multiple logistic regression revealed anorexia (p-value 0.018), right iliac fossa tenderness (p-value 0.005) and guarding (p-value 0.047) as significant clinical factors independently associated with appendicitis.
CONCLUSION: Appendicitis scoring systems have shown moderate sensitivity and specificity in our population. The RIPASA scoring system has shown to be the most sensitive, specific and easy-to-use scoring system in the Malaysian population whereas the AAS is most accurate in excluding low-risk patients.
Fulltext Characterization of the highly active polyhydroxyalkanoate synthase of Chromobacterium sp. strain USM2

Bhubalan K, Chuah JA, Shozui F, Brigham CJ, Taguchi S, Sinskey AJ, et al.

Appl Environ Microbiol, 2011 May;77(9):2926-33.
PMID: 21398494 DOI: 10.1128/AEM.01997-10

The synthesis of bacterial polyhydroxyalkanoates (PHA) is very much dependent on the expression and activity of a key enzyme, PHA synthase (PhaC). Many efforts are being pursued to enhance the activity and broaden the substrate specificity of PhaC. Here, we report the identification of a highly active wild-type PhaC belonging to the recently isolated Chromobacterium sp. USM2 (PhaC(Cs)). PhaC(Cs) showed the ability to utilize 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), and 3-hydroxyhexanoate (3HHx) monomers in PHA biosynthesis. An in vitro assay of recombinant PhaC(Cs) expressed in Escherichia coli showed that its polymerization of 3-hydroxybutyryl-coenzyme A activity was nearly 8-fold higher (2,462 ± 80 U/g) than that of the synthase from the model strain C. necator (307 ± 24 U/g). Specific activity using a Strep2-tagged, purified PhaC(Cs) was 238 ± 98 U/mg, almost 5-fold higher than findings of previous studies using purified PhaC from C. necator. Efficient poly(3-hydroxybutyrate) [P(3HB)] accumulation in Escherichia coli expressing PhaC(Cs) of up to 76 ± 2 weight percent was observed within 24 h of cultivation. To date, this is the highest activity reported for a purified PHA synthase. PhaC(Cs) is a naturally occurring, highly active PHA synthase with superior polymerizing ability.
Variant Alleles in XRCC1 Arg194Trp and Arg399Gln Polymorphisms Increase Risk of Gastrointestinal Cancer in Sabah, North Borneo

Halim NH, Chong ET, Goh LP, Chuah JA, See EU, Chua KH, et al.

Asian Pac J Cancer Prev, 2016;17(4):1925-31.
PMID: 27221877

BACKGROUND: The XRCC1 protein facilitates various DNA repair pathways; single-nucleotide polymorphisms (SNPs) in this gene are associated with a risk of gastrointestinal cancer (GIC) with inconsistent results, but no data have been previously reported for the Sabah, North Borneo, population. We accordingly investigated the XRCC1 Arg194Trp and Arg399Gln SNPs in terms of GIC risk in Sabah.
MATERIALS AND METHODS: We performed genotyping for both SNPs for 250 GIC patients and 572 healthy volunteers using a polymerase chain reaction- restriction fragment length polymorphism approach. We validated heterozygosity and homozygosity for both SNPs using direct sequencing.
RESULTS: The presence of a variant 194Trp allele in the Arg194Trp SNP was significantly associated with a higher risk of GIC, especially with gastric and colorectal cancers. We additionally found that the variant 399Gln allele in Arg399Gln SNP was associated with a greater risk of developing gastric cancer. Our combined analysis revealed that inheritance of variant alleles in both SNPs increased the GIC risk in Sabah population. Based on our etiological analysis, we found that subjects ≥50 years and males who carrying the variant 194Trp allele, and Bajau subjects carrying the 399Gln allele had a significantly increased risk of GIC.
CONCLUSIONS: Our findings suggest that inheritance of variant alleles in XRCC1 Arg194Trp and Arg399Gln SNPs may act as biomarkers for the early detection of GIC, especially for gastric and colorectal cancers in the Sabah population.
Fulltext Effect of decomposing oil palm trunk fibers on plant growth and soil microbial community composition

Uke A, Nakazono-Nagaoka E, Chuah JA, Zain NA, Amir HG, Sudesh K, et al.

J Environ Manage, 2021 Oct 01;295:113050.
PMID: 34198177 DOI: 10.1016/j.jenvman.2021.113050

Oil palm trunks (OPT) are logged for replantation and the fiber residues are disposed of into the palm plantation area. The fiber residues are expected to increase soil fertility through recycling of carbon and minerals via fiber decomposition. This study investigated the effects of OPT fiber disposal and other lignocellulosic biomass on plant growth and microbial diversity in the soil environment. Four treatment plots were tested: (A) soil+OPT fiber (1:20), (B) soil+sugarcane bagasse (1:20), (C) soil+cellulose powder (1:20), and (D) unamended soil as a negative control. Low plant height, decreased chlorophyll content, and low biomass was observed in corn grown on soil mixed with OPT fiber, cellulose, and sugarcane bagasse, when compared with those of the control. The plants grown with OPT fiber were deficient in total nitrogen and magnesium when compared with those without fiber amendment, which suggested that nitrogen and minerals in soil might be taken up by changing microflora because of the OPT fibers presence. To confirm differences in the soil microflora, metagenomics analysis was performed on untreated soil and soil from each lignocellulose treatment. The microflora of soils mixed with OPT fiber, cellulose and sugarcane bagasse revealed substantial increases in bacteria such as families Cytophagaceae and Oscillospiraceae, and two major fungal genera, Trichoderma and Trichocladium, that are involved in lignocellulose degradation. OPT fiber resulted in a drastic increase in the ratios and amounts of Trichocladium in the soil when compared with those of cellulose and sugarcane bagasse. These results indicate that unregulated disposal of OPT fiber into plantation areas could result in nutrient loss from soil by increasing the abundance of microorganisms involved in lignocellulose decomposition.