The association between H. pylori infection and pancreatic cancer risk remains controversial. We conducted a nested case-control study with 448 pancreatic cancer cases and their individually matched control subjects, based on the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, to determine whether there was an altered pancreatic cancer risk associated with H. pylori infection and chronic corpus atrophic gastritis. Conditional logistic regression models were applied to calculate odds ratios (ORs) and corresponding 95% confidence intervals (CIs), adjusted for matching factors and other potential confounders. Our results showed that pancreatic cancer risk was neither associated with H. pylori seropositivity (OR = 0.96; 95% CI: 0.70, 1.31) nor CagA seropositivity (OR = 1.07; 95% CI: 0.77, 1.48). We also did not find any excess risk among individuals seropositive for H. pylori but seronegative for CagA, compared with the group seronegative for both antibodies (OR = 0.94; 95% CI: 0.63, 1.38). However, we found that chronic corpus atrophic gastritis was non-significantly associated with an increased pancreatic cancer risk (OR = 1.35; 95% CI: 0.77, 2.37), and although based on small numbers, the excess risk was particularly marked among individuals seronegative for both H. pylori and CagA (OR = 5.66; 95% CI: 1.59, 20.19, p value for interaction
Exposure of Normal Human Osteoblast cells (NHOst) to a period of hypothermia may interrupt their cellular functions, lead to changes in bone matrix and disrupt the balance between bone formation and resorption, resulting in bone loss or delayed fracture healing. To investigate this possibility, we exposed NHOst cells to moderate (35 °C) and severe (27 °C) hypothermia for 1, 12, 24 and 72 h. The effects of hypothermia with respect to cell cytoskeleton organization, metabolic activity and the expression of cold shock chaperone proteins, osteoblast transcription factors and functional markers, were examined. Our findings showed that prolonged moderate hypothermia retained the polymerization of the cytoskeletal components. NHOst cell metabolism was affected differently according to hypothermia severity. The osteoblast transcription factors Runx2 and osterix were necessary for the transcription and translation of bone matrix proteins, where alkaline phosphatase (Alp) activity and osteocalcin (OCN) bone protein were over expressed under hypothermic conditions. Consequently, bone mineralization was stimulated after exposure to moderate hypothermia for 1 week, indicating bone function was not impaired. The cold shock chaperone protein Rbm3 was significantly upregulated (p<0.001) during the cellular stress adaption under hypothermic conditions. We suggest that Rbm3 has a dual function: one as a chaperone protein that stabilizes mRNA transcripts and a second one in enhancing the transcription of Alp and Ocn genes. Our studies demonstrated that hypothermia permitted the in vitro maturation of NHOst cells probably through an osterix-dependent pathway. For that reason, we suggest that moderate hypothermia can be clinically applied to counteract heat production at the fracture site that delays fracture healing.
Epithelial-to-Mesenchymal Transition (EMT) has been shown to be crucial in tumorigenesis where the EMT program enhances metastasis, chemoresistance and tumor stemness. Due to its emerging role as a pivotal driver of tumorigenesis, targeting EMT is of great therapeutic interest in counteracting metastasis and chemoresistance in cancer patients. The hallmark of EMT is the upregulation of N-cadherin followed by the downregulation of E-cadherin, and this process is regulated by a complex network of signaling pathways and transcription factors. In this review, we summarized the recent understanding of the roles of E- and N-cadherins in cancer invasion and metastasis as well as the crosstalk with other signaling pathways involved in EMT. We also highlighted a few natural compounds with potential anti-EMT property and outlined the future directions in the development of novel intervention in human cancer treatments. We have reviewed 287 published papers related to this topic and identified some of the challenges faced in translating the discovery work from bench to bedside.
The number of patients with Alzheimer's disease (AD) is rapidly increasing in Asia. Mutations in the amyloid protein precursor (APP), presenilin-1 (PSEN1), and presenilin-2 (PSEN2) genes can cause autosomal dominant forms of early-onset AD (EOAD). Although these genes have been extensively studied, variant classification remains a challenge, highlighting the need to colligate mutations across populations. In this study, we performed a genetic screening for mutations in the APP, PSEN1, and PSEN2 genes in 200 clinically diagnosed EOAD patients across four Asian countries, including Thailand, Malaysia, the Philippines, and Korea, between 2009 and 2018. Thirty-two (16%) patients presented pathogenic APP, PSEN1, or PSEN2 variants; eight (25%), 19 (59%), and five (16%) of the 32 patients presented APP, PSEN1, and PSEN2 variants, respectively. Among the 21 novel and known non-synonymous variants, five APP variants were found in Korean patients and one APP variant was identified in a Thai patient with EOAD. Nine, two, and one PSEN1 mutation was found in a Korean patient, Malaysian siblings, and a Thai patient, respectively. Unlike PSEN1 mutations, PSEN2 mutations were rare in patients with EOAD; only three variants were found in Korean patients with EOAD. Comparison of AD-causative point mutations in Asian countries; our findings explained only a small fraction of patients, leaving approximately 84% (p = 0.01) of autosomal dominant pedigrees genetically unexplained. We suggest that the use of high-throughput sequencing technologies for EOAD patients can potentially improve our understanding of the molecular mechanisms of AD.
Partial gene sequences of phenylalanyl-tRNA synthase alpha subunit (pheS) and RNA polymerase alpha subunit (rpoA) were evaluated for species delineation and detection of recombination among enterococci populations recovered from a bathing beach impacted by low tide river flow. At inter-species level, a maximum similarity of 86.5% and 94.8% was observed among the enterococci pheS and rpoA sequence, respectively. A superimposed plot of delimited pairwise similarity values obtained for 266 pair-wise observations revealed that while there was a harmony between species identity obtained from both genes, pheS was more discriminatory than rpoA. The difference was more pronounced for inter-species comparison. A number of putative recombination events between indigenous and non-indigenous strains was detected based on a library of aligned sequences. Virulence genes cyl, esp, gelE and asa were detected in 7, 22, 100 and 63%, respectively among river isolates but at lower proportion of 0, 20, 67 and 42%, respectively among beach water isolates. Random amplified polymorphic DNA profiling presented evidence suggesting low tide river as a source of fecal enterococci entering the recreation beach water. Multilocus sequence typing analysis of a number of Enterococcus faecalis isolates presented four sequence types, ST59, 117, 181 and 474. The presence of genetically diverse fecal enterococci with associated virulence traits and a background of recombination events in surface recreational water could present a potential public health risk.
This work studied the correlations between survivin, bcl-2 and p53 in infiltrating ductal carcinoma of the breast. A total number of 382 cases were collected from 3 hospitals in northeastern Malaysia. Survivin, bcl-2 and p53 were detected by immunohistochemistry on samples prepared from tissue blocks. Significant correlations were found between tumor histological grades and tumor size and lymph node involvement. Highly significant statistical correlations (p<0.001) were found in expression of the markers under study. It is concluded that such significant correlations may imply that the alterations in the expression take place in a concerted fashion, implying that many of these cases may share common abnormalities.
Matched MeSH terms: Breast Neoplasms/genetics; Microtubule-Associated Proteins/genetics; Neoplasm Proteins/genetics; Tumor Suppressor Protein p53/genetics; Carcinoma, Ductal, Breast/genetics
Rice tungro disease (RTD) is a recurring disease affecting rice farming especially in the South and Southeast Asia. The disease is commonly diagnosed by visual observation of the symptoms on diseased plants in paddy fields and by polymerase chain reaction (PCR). However, visual observation is unreliable and PCR can be costly. High-throughput as well as relatively cheap detection methods are important for RTD management for screening large number of samples. Due to this, detection by serological assays such as immunoblotting assays and enzyme-linked immunosorbent assay are preferred. However, these serological assays are limited by lack of continuous supply of antibodies as reagents due to the difficulty in preparing sufficient purified virions as antigens. This study aimed to generate and evaluate the reactivity of the recombinant coat proteins of Rice tungro bacilliform virus (RTBV) and Rice tungro spherical virus (RTSV) as alternative antigens to generate antibodies. The genes encoding the coat proteins of both viruses, RTBV (CP), and RTSV (CP1, CP2 and CP3) were cloned and expressed as recombinant fusion proteins in Escherichia coli. All of the recombinant fusion proteins, with the exception of the recombinant fusion protein of the CP2 of RTSV, were reactive against our in-house anti-tungro rabbit serum. In conclusion, our study showed the potential use of the recombinant fusion coat proteins of the tungro viruses as alternative antigens for production of antibodies for diagnostic purposes.
The stearoyl-acyl-carrier-protein (ACP) desaturase is a plastid-localized enzyme that catalyzes the conversion of stearoyl-ACP to oleoyl-ACP and plays an important role in the determination of the properties of the majority of cellular glycerolipids. Functional characterization of the fatty acid desaturase genes and their specific promoters is a prerequisite for altering the composition of unsaturated fatty acids of palm oil by genetic engineering. In this paper, the specificity and strength of the oil palm stearoyl-ACP desaturase gene promoter (Des) was evaluated in transgenic tomato plants. Transcriptional fusions between 5' deletions of the Des promoter (Des1-4) and the β-glucuronidase (GUS) reporter gene were generated and their expression analyzed in different tissues of stably transformed tomato plants. Histochemical analysis of the Des promoter deletion series revealed that GUS gene expression was confined to the tomato fruits. No expression was detected in vegetative tissues of the transgenic plants. The highest levels of GUS activity was observed in different tissues of ripe red fruits (vascular tissue, septa, endocarp, mesocarp and columella) and in seeds, which harbored the promoter region located between -590 and +10. A comparison of the promoter-deletion constructs showed that the Des4 promoter deletion (314bp) produced a markedly low level of GUS expression in fruits and seeds. Fluorometric analysis of the GUS activity revealed a 4-fold increase in the activity of the full-length Des promoter compared to the CaMV35S promoter. RNA-hybridization analyses provided additional evidence of increased GUS expression in fruits driven by a Des fragment. Taken together, these results demonstrate the potential of the Des promoter as a tool for the genetic engineering of oil palms and other species, including dicots, in improving the quality and nutritional value of the fruits.
Monodehydroascorbate reductase (MDHAR), an important enzyme of the ascorbate-glutathione cycle, is involved in salt tolerance of plants through scavenging of reactive oxygen species (ROS). In this study, a cDNA encoding MDHAR from the mangrove plant Acanthus ebracteatus was introduced into rice to examine its role in salt tolerance. Three stable transgenic lines (MT22, MT24 and MT25) overexpressing AeMDHAR were selected in vitro using hygromycin and confirmed by PCR, quantitative reverse-transcription (qRT) PCR and enzyme assay. The transgenic line MT24 was predicted to possess a single copy of the transgene while the other two transgenic lines were predicted to have multiple transgene integrations. The AeMDHAR transcripts were detected only in transgenic rice lines but not in untransformed rice. The abundance of AeMDHAR transcripts in transgenic lines MT22 and MT25 was approximately 2.75 times the amount found in MT24. The transgenic rice lines overexpressing AeMDHAR showed a significant increase in MDHAR enzyme activity compared to untransformed plants under both NaCl and control conditions. All transgenic lines showed better yield attributes such as a higher tiller number and increased 1000-grain weight compared to non-transgenics. They also showed tolerance to salt at germination and seedling stages. The transgenic line MT24, which harbors a single copy of AeMDHAR, displayed a lower rate of sterility, a higher number of tillers and longer panicle compared to untransformed plants when subjected to salt stress.
Nitric oxide associated 1 (NOA1) protein is implicated in plant disease resistance and nitric oxide (NO) biosynthesis. A full-length cDNA encoding of NOA1 protein from oil palm (Elaeis guineensis) was isolated and designated as EgNOA1. Sequence analysis suggested that EgNOA1 was a circular permutated GTPase with high similarity to the bacterial YqeH protein of the YawG/YlqF family. The gene expression of EgNOA1 and NO production in oil palm root tissues treated with Ganoderma boninense, the causal agent of basal stem rot (BSR) disease were profiled to investigate the involvement of EgNOA1 during fungal infection and association with NO biosynthesis. Real-time PCR (qPCR) analysis revealed that the transcript abundance of EgNOA1 in root tissues was increased by G. boninense treatment. NO burst in Ganoderma-treated root tissue was detected using Griess reagent, in advance of the up-regulation of the EgNOA1 transcript. This indicates that NO production was independent of EgNOA1. However, the induced expression of EgNOA1 in Ganoderma-treated root tissues implies that it might be involved in plant defense responses against pathogen infection.
In gram-negative bacteria, bacterial communication or quorum sensing (QS) is achieved using common signaling molecules known as N-acyl homoserine lactones (AHL). We have previously reported the genome of AHL-producing bacterium, Enterobacter asburiae strain L1. In silico analysis of the strain L1 genome revealed the presence of a pair of luxI/R genes responsible for AHL-type QS, designated as easIR. In this work, the 639 bp luxI homolog, encoding 212 amino acids, have been cloned and overexpressed in Escherichia coli BL21 (DE3)pLysS. The purified protein (~25 kDa) shares high similarity to several members of the LuxI family among different E asburiae strains. Our findings showed that the heterologously expressed EasI protein has activated violacein production by AHL biosensor Chromobacterium violaceum CV026 as the wild-type E. asburiae. The mass spectrometry analysis showed the production of N-butanoyl homoserine lactone and N-hexanoyl homoserine lactone from induced E. coli harboring the recombinant EasI, suggesting that EasI is a functional AHL synthase. E. asburiae strain L1 was also shown to possess biofilm-forming characteristic activity using crystal violet binding assay. This is the first report on cloning and characterization of the luxI homolog from E. asburiae.
Morinda citrifolia, is a valuable medicinal plant with a wide range of therapeutic properties and extensive transformation study on this plant has yet been known. Present study was conducted to establish a simple and reliable transformation protocol for M. citrifolia utilising Agrobacterium tumefaciens via direct seed exposure. In this study, the seeds were processed by tips clipping and dried and subsequently incubated in inoculation medium. Four different parameters during the incubation such as incubation period, bacterial density, temperature and binary vectors harbouring beta-glucuronidase (GUS) gene (pBI121 and pGSA1131), were tested to examine its effect on transformation efficiency. The leaves from the treated and germinated seedlings were analysed via Polymerase Chain Reaction (PCR), histochemical assay of the GUS gene and reverse transcription-PCR (RT-PCR). Results of the study showed that Agrobacterium strain LBA4404 with optical density of 1.0 and 2 h incubation period were optimum for M. citrifolia transformation. It was found that various co-cultivation temperatures tested and type of vector used did not affect the transformation efficiency. The highest transformation efficiency for M. citrifolia direct seed transformation harbouring pBI121 and pGSA1131 was determined to be 96.8% with 2 h co-cultivation treatment and 80.4% when using bacterial density of 1.0, respectively. The transformation method can be applied for future characterization study of M. citrifolia.
Recently, the bitter receptor gene (TAS2R38) was identified to be responsible for phenylthiocarbamide (PTC) bitter sensitivity. Its two predominant haplotypes at three Single Nucleotide Polymorphisms (SNPs) are found to be definitive for the PTC status, which the ProAlaVal and AlaValIle haplotypes are associated with tasters and non-tasters, respectively. TAS2R38 haplotypes have been reported to influence food preferences (like cruciferous vegetables and fat foods) and cardiovascular disease risk factors. We examined, in 215 Malaysian subjects (100 males, 115 females), the association of the P49A SNP of TAS2R38 with anthropometric measurements and aversion to a list of 36 vegetables, 4 soy products, green tea and 37 sweet/fat foods. The subjects were successfully genotyped as 110 PA, 81 PP and 24 AA (with the A49 allelic frequency of 0.37), by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP). Ethnicity (Malay, Chinese or Indian), but not gender, was associated with the P49A TAS2R38 genotypes (p<0.001). However, no significant differences in terms of Body Mass Index, Total Body Fat, waist circumference and Waist-Hip Ratio were found between the genotypes (p<0.05). Only aversions to green tea, mayonnaise and whipped cream, but not soy products, vegetables, and other sweet/fat foods, were associated with the P49A genotypes (p<0.05). Therefore, the P49A SNP of the bitter receptor gene TAS2R38 could not serve as a predictor of anthropometric measurements and aversion to vegetables or sweet/fat foods in the sampled Malaysian subjects, and this suggests the existence of other possible factors influencing food selection among Malaysians.
Matched MeSH terms: Ethnic Groups/genetics; Polymorphism, Restriction Fragment Length/genetics; Taste/genetics*; Polymorphism, Single Nucleotide/genetics; Receptors, G-Protein-Coupled/genetics*
The nucleocapsid (N) protein of Nipah virus (NiV) can be produced in three Escherichia coli strains [TOP10, BL21(DE3) and SG935] under the control of trc promoter. However, most of the product existed in the form of insoluble inclusion bodies. There was no improvement in the solubility of the product when this protein was placed under the control of T7 promoter. However, the solubility of the N protein was significantly improved by lowering the growth temperature of E. coli BL21(DE3) cell cultures. Solubility analysis of N- and C-terminally deleted mutants revealed that the full-length N protein has the highest solubility. The soluble N protein could be purified efficiently by sucrose gradient centrifugation and nickel affinity chromatography. Electron microscopic analysis of the purified product revealed that the N protein assembled into herringbone-like particles of different lengths. The C-terminal end of the N protein contains the major antigenic region when probed with antisera from humans and pigs infected naturally.
The release of DNA into the cytoplasm upon damage to the nucleus or during viral infection triggers an interferon-mediated defense response, inflammation and cell death. In human cells cytoplasmic DNA is sensed by cyclic GMP-AMP Synthase (cGAS) and Absent In Melanoma 2 (AIM2). Here, we report the identification of a "natural knockout" model of cGAS. Comparative genomics of phylogenetically diverse mammalian species showed that cGAS and its interaction partner Stimulator of Interferon Genes (STING) have been inactivated by mutations in the Malayan pangolin whereas other mammals retained intact copies of these genes. The coding sequences of CGAS and STING1 are also disrupted by premature stop codons and frame-shift mutations in Chinese and tree pangolins, suggesting that expression of these genes was lost in a common ancestor of all pangolins that lived more than 20 million years ago. AIM2 is retained in a functional form in pangolins whereas it is inactivated by mutations in carnivorans, the phylogenetic sister group of pangolins. The deficiency of cGAS and STING points to the existence of alternative mechanisms of controlling cytoplasmic DNA-associated cell damage and viral infections in pangolins.
Four red cell enzyme systems were studied in Malaysian mothers and their newborn belonging to three racial groups, the Malays, Indians and Chinese. No significant heterogeneity was observed in the distribution of phosphoglucomutase (PGM1), adenosine deaminase (ADA), 6-phosphogluconate dehydrogenase (6PGD) and acid phosphatase (AP) phenotypes between mothers and their newborn of the three groups. Pooled mother and child acid phosphatase data show a significant heterogeneity between the Malays and Chinese, and between the Malays and Indians. This is comparable to previous studies conducted. For the placental phosphoglucomutase (PGM3) system, a significant heterogeneity was observed between the Chinese and Malays only. No significant heterogeneity was detected in the distribution of PGM1, ADA and 6PGD phenotypes among Malays, Chinese and Indians.
The distribution of two common DNA polymorphisms (5' untranslated exon 1 and intron 5-DdeI) of the antithrombin III (ATIII) gene was studied in three ethnic groups in Singapore: 251 Chinese, 221 Dravidian Indians and 102 Malays. The polymorphisms were identified by the polymerase chain reaction and size fractionation in agarose gels. The 5' untranslated to exon 1 polymorphism is a length polymorphism while the intron 5 polymorphism is a restriction site (DdeI) polymorphism. The frequency of the short fragment (S) of the 5' to exon 1 length polymorphism of the ATIII gene was found to be 0.37 in the Chinese, 0.54 in the Malays and 0.65 in the Dravidian Indians. For the Chinese, this was significantly lower compared to the Caucasians and Indians (p < 0.0001) and the Malays (p < 0.01). On the other hand, the frequencies of DdeI+ did not vary significantly among these three populations (p > 0.05). The distribution of different genotypes at these two loci of the ATIII gene was in Hardy-Weinberg equilibrium in all three ethnic groups. A strong linkage disequilibrium between these two polymorphisms was observed in all the ethnic groups and the estimated correlation coefficient (delta) was 0.42 in the Chinese (p < 0.001), 0.61 in the Dravidian Indians (p < 0.001) and 0.43 in the Malays (p < 0.001). The frequencies of haplotype S+, L+ and L- were, respectively, 0.37, 0.40 and 0.23 in the Chinese, 0.65, 0.18 and 0.16 in the Dravidian Indians and 0.54, 0.37 and 0.09 in the Malays.(ABSTRACT TRUNCATED AT 250 WORDS)
Piperaquine combined with dihydroartemisinin is one of the artemisinin derivative combination therapies, which can replace artesunate-mefloquine in treating uncomplicated falciparum malaria in Thailand. The aim of this study was to determine the in vitro sensitivity of Thai Plasmodium falciparum isolates against piperaquine and the influence of the pfmdr1 gene on in vitro response. One hundred and thirty-seven standard laboratory and adapted Thai isolates of P. falciparum were assessed for in vitro piperaquine sensitivity. Polymorphisms of the pfmdr1 gene were determined by polymerase chain reaction methods. The mean and standard deviation of the piperaquine IC50 in Thai isolates of P. falciparum were 16.7 ± 6.3 nM. The parasites exhibiting chloroquine IC50 of ≥ 100 nM were significantly less sensitive to piperaquine compared with the parasite with chloroquine IC50 of < 100 nM. No significant association between the pfmdr1 copy number and piperaquine IC50 values was found. In contrast, the parasites containing the pfmdr1 86Y allele exhibited significantly reduced piperaquine sensitivity. Before nationwide implementation of dihydroartemisinin-piperaquine as the first-line treatment in Thailand, in vitro and in vivo evaluations of this combination should be performed especially in areas where parasites containing the pfmdr1 86Y allele are predominant such as the Thai-Malaysian border.
Matched MeSH terms: Drug Resistance/genetics*; Plasmodium falciparum/genetics*; Protozoan Proteins/genetics; Membrane Transport Proteins/genetics; Multidrug Resistance-Associated Proteins/genetics*
This study describes our investigation on the prevalence and molecular identification of bartonellae from Rattus diardii and R. norvegicus in the urban areas of Malaysia. Of 95 rats investigated, Bartonella tribocorum, B. rattimassiliensis, B. coopersplainsensis, B. elizabethae, and B. queenslandensis were isolated from kidney and spleen homogenates of four rats. Bartonellae DNA was amplified from the rat organ tissues by using primers specific for the bartonellae RNA polymerase beta subunit (rpoB) gene in nine other rats. Sequence analysis of the rpoB gene fragments shows the identification of B. queenslandensis in five rats, B. elizabethae in three rats, and B. tribocorum in one rat. Combining the results of isolation and molecular detection of bartonellae, we found that the prevalence of Bartonella infection in the Rattus spp. investigated in this study was 13.7%. Implementation of effective rat control program in the urban areas is necessary to prevent the spillover of bartonellosis from rats to humans.