Displaying publications 1 - 20 of 56 in total

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  1. Fulltext Dengue virus type 2 envelope protein displayed as recombinant phage attachment protein reveals potential cell binding sites
    Abd-Jamil J, Cheah CY, AbuBakar S
    Protein Eng. Des. Sel., 2008 Oct;21(10):605-11.
    PMID: 18669522 DOI: 10.1093/protein/gzn041
    A method to map the specific site on dengue virus envelope protein (E) that interacts with cells and a neutralizing antibody is developed using serially truncated dengue virus type 2 (DENV-2) E displayed on M13 phages as recombinant E-g3p fusion proteins. Recombinant phages displaying the truncated E consisting of amino acids 297-423 (EB2) and amino acids 379-423 (EB4) were neutralized by DENV-2 patient sera and the DENV-2 E-specific 3H5-1 monoclonal antibodies suggesting that the phages retained the DENV-2 E antigenic properties. The EB4 followed by EB2 recombinant phages bound the most to human monocytes (THP-1), African green monkey kidney (Vero) cells, mosquito (C6/36) cells, ScFv specific against E and C6/36 cell proteins. Two potential cell attachment sites were mapped to loop I (amino acids 297 to 312) and loop II (amino acids 379-385) of the DENV-2 E using the phage-displayed truncated DENV-2 E fragments and by the analysis of the E structure. Loop II was present only in EB4 recombinant phages. There was no competition for binding to C6/36 cell proteins between EB2 and EB4 phages. Loop I and loop II are similar to the sub-complex specific and type-specific neutralizing monoclonal antibody binding sites, respectively. Hence, it is proposed that binding and entry of DENV involves the interaction of loop I to cell surface glycosaminoglycan-motif and a subsequent highly specific interaction involving loop II with other cell proteins. The phage displayed truncated DENV-2 E is a powerful and useful method for the direct determination of DENV-2 E cell binding sites.
    Matched MeSH terms: Gene Deletion
  2. G6PD deficiency with hemolytic anemia due to a rare gene deletion--a report of the first case in Malaysia
    Ainoon O, Boo NY, Yu YH, Cheong SK, Hamidah HN
    Hematology, 2006 Apr;11(2):113-8.
    PMID: 16753852 DOI: 10.1080/10245330500155184
    A 2-year-old Chinese boy was referred to Hospital UKM for investigation of recurrent episodes of dark-coloured urine and pallor since birth. He was born prematurely at 34 weeks gestation and developed severe early-onset neonatal jaundice requiring exchange blood transfusion. Screening at birth showed Glucose-6-phosphate dehydrogenase (G6PD) deficiency. On admission, physical examination revealed pallor, jaundice and mild hepatomegaly. Results of laboratory investigations showed a hemoglobin level of 11.0 g/dl with a hemolytic blood picture, reticulocytosis of 20% and red cell G6PD activity reported as undetectable. The patient's DNA was analysed for G6PD mutations by PCR-based techniques and DNA sequencing and results showed a 24 bp deletion of nucleotide 953-976 in the exon 9 of the G6PD gene. DNA analysis was also performed on blood samples of the patient's mother and female sibling confirming their heterozygous status, although both showed normal red cell G6PD activity levels. The patient was discharged well and his parents were appropriately advised on the condition and the importance of taking folic acid regularly. This is a first case report in Malaysia of G6PD deficiency causing chronic-hemolytic anemia. The rare 24 bp deletion causes the G6PD Nara variant, previously reported only in two other unrelated males, a Japanese and a Portuguese both with chronic hemolytic anemia.
    Matched MeSH terms: Gene Deletion*
  3. Fulltext Analysis of sequence variations in low-density lipoprotein receptor gene among Malaysian patients with familial hypercholesterolemia
    Al-Khateeb A, Zahri MK, Mohamed MS, Sasongko TH, Ibrahim S, Yusof Z, et al.
    BMC Med Genet, 2011;12:40.
    PMID: 21418584 DOI: 10.1186/1471-2350-12-40
    Familial hypercholesterolemia is a genetic disorder mainly caused by defects in the low-density lipoprotein receptor gene. Few and limited analyses of familial hypercholesterolemia have been performed in Malaysia, and the underlying mutations therefore remain largely unknown.We studied a group of 154 unrelated FH patients from a northern area of Malaysia (Kelantan). The promoter region and exons 2-15 of the LDLR gene were screened by denaturing high-performance liquid chromatography to detect short deletions and nucleotide substitutions, and by multiplex ligation-dependent probe amplification to detect large rearrangements.
    Matched MeSH terms: Gene Deletion
  4. Helicobacter pylori outer inflammatory protein A (OipA) suppresses apoptosis of AGS gastric cells in vitro
    Al-Maleki AR, Loke MF, Lui SY, Ramli NSK, Khosravi Y, Ng CG, et al.
    Cell. Microbiol., 2017 12;19(12).
    PMID: 28776327 DOI: 10.1111/cmi.12771
    Outer inflammatory protein A (OipA) is an important virulence factor associated with gastric cancer and ulcer development; however, the results have not been well established and turned out to be controversial. This study aims to elucidate the role of OipA in Helicobacter pylori infection using clinical strains harbouring oipA "on" and "off" motifs. Proteomics analysis was performed on AGS cell pre-infection and postinfection with H. pylori oipA "on" and "off" strains, using liquid chromatography/mass spectrometry. AGS apoptosis and cell cycle assays were performed. Moreover, expression of vacuolating cytotoxin A (VacA) was screened using Western blotting. AGS proteins that have been suggested previously to play a role or associated with gastric disease were down-regulated postinfection with oipA "off" strains comparing to oipA "on" strains. Furthermore, oipA "off" and ΔoipA cause higher level of AGS cells apoptosis and G0/G1 cell-cycle arrest than oipA "on" strains. Interestingly, deletion of oipA increased bacterial VacA production. The capability of H. pylori to induce apoptosis and suppress expression of proteins having roles in human disease in the absence of oipA suggests that strains not expressing OipA may be less virulent or may even be protective against carcinogenesis compared those expressing OipA. This potentially explains the higher incidence of gastric cancer in East Asia where oipA "on" strains predominates.
    Matched MeSH terms: Gene Deletion
  5. Identification of novel extracellular protein for PCB/biphenyl metabolism in Rhodococcus jostii RHA1
    Atago Y, Shimodaira J, Araki N, Bin Othman N, Zakaria Z, Fukuda M, et al.
    Biosci Biotechnol Biochem, 2016 May;80(5):1012-9.
    PMID: 26828632 DOI: 10.1080/09168451.2015.1127134
    Rhodococcus jostii RHA1 (RHA1) degrades polychlorinated biphenyl (PCB) via co-metabolism with biphenyl. To identify the novel open reading frames (ORFs) that contribute to PCB/biphenyl metabolism in RHA1, we compared chromatin immunoprecipitation chip and transcriptomic data. Six novel ORFs involved in PCB/biphenyl metabolism were identified. Gene deletion mutants of these 6 ORFs were made and were tested for their ability to grow on biphenyl. Interestingly, only the ro10225 deletion mutant showed deficient growth on biphenyl. Analysis of Ro10225 protein function showed that growth of the ro10225 deletion mutant on biphenyl was recovered when exogenous recombinant Ro10225 protein was added to the culture medium. Although Ro10225 protein has no putative secretion signal sequence, partially degraded Ro10225 protein was detected in conditioned medium from wild-type RHA1 grown on biphenyl. This Ro10225 fragment appeared to form a complex with another PCB/biphenyl oxidation enzyme. These results indicated that Ro10225 protein is essential for the formation of the PCB/biphenyl dioxygenase complex in RHA1.
    Matched MeSH terms: Gene Deletion
  6. Fulltext Molecular characteristic of alpha thalassaemia among patients diagnosed in UKM Medical Centre
    Azma RZ, Ainoon O, Hafiza A, Azlin I, Noor Farisah AR, Nor Hidayati S, et al.
    Malays J Pathol, 2014 Apr;36(1):27-32.
    PMID: 24763232 MyJurnal
    Alpha (Α) thalassaemia is the most common inherited disorder in Malaysia. The clinical severity is dependant on the number of Α genes involved. Full blood count (FBC) and haemoglobin (Hb) analysis using either gel electrophoresis, high performance liquid chromatography (HPLC) or capillary zone electrophoresis (CE) are unable to detect definitively alpha thalassaemia carriers. Definitive diagnosis of Α-thalassaemias requires molecular analysis and methods of detecting both common deletional and non-deletional molecular abnormailities are easily performed in any laboratory involved in molecular diagnostics. We carried out a retrospective analysis of 1623 cases referred to our laboratory in Universiti Kebangsaan Malaysia Medical Centre (UKMMC) for the diagnosis of Α-thalassaemia during the period October 2001 to December 2012. We examined the frequency of different types of alpha gene abnormalities and their haematologic features. Molecular diagnosis was made using a combination of multiplex polymerase reaction (PCR) and real time PCR to detect deletional and non-deletional alpha genes relevant to southeast Asian population. Genetic analysis confirmed the diagnosis of Α-thalassaemias in 736 cases. Majority of the cases were Chinese (53.1%) followed by Malays (44.2%), and Indians (2.7%). The most common gene abnormality was ΑΑ/--(SEA) (64.0%) followed by ΑΑ/-Α(3.7) (19.8%), -Α(3.7) /--(SEA) (6.9%), ΑΑ/ΑΑCS (3.0%), --(SEA)/--(SEA) (1.2%), -Α(3.7)/-Α(3.7) (1.1%), ΑΑ/-Α(4.2) (0.7%), -Α(4.2)/--(SEA (0.7%), -Α(3.7)/-Α(4.2) (0.5%), ΑΑ(CS)/-- SEA) (0.4%), ΑΑ(CS)/ΑΑ(Cd59) (0.4%), ΑΑ(CS)/ΑΑ(CS) (0.4%), -Α(3.7)/ΑΑ(Cd59) (0.3%), ΑΑ/ΑΑ(Cd59) (0.1%), ΑΑ(Cd59)/ ΑΑ(IVS I-1) (0.1%), -Α(3.7)/ΑΑ(CS) (0.1%) and --(SEA) /ΑΑ(Cd59) (0.1%). This data indicates that the molecular abnormalities of Α-thalassaemia in the Malaysian population is heterogenous. Although Α-gene deletion is the most common cause, non-deletional Α-gene abnormalities are not uncommon and at least 3 different mutations exist. Establishment of rapid and easy molecular techniques is important for definitive diagnosis of alpha thalassaemia, an important prerequisite for genetic counselling to prevent its deleterious complications.
    Matched MeSH terms: Gene Deletion
  7. Fulltext Co-inheritance of compound heterozygous Hb Constant Spring and a single -alpha(3.7) gene deletion with heterozygous deltabeta thalassaemia: a diagnostic challenge
    Azma RZ, Othman A, Azman N, Alauddin H, Ithnin A, Yusof N, et al.
    Malays J Pathol, 2012 Jun;34(1):57-62.
    PMID: 22870600
    Haemoglobin Constant Spring (Hb CS) mutation and single gene deletions are common underlying genetic abnormalities for alpha thalassaemias. Co-inheritance of deletional and non-deletional alpha (alpha) thalassaemias may result in various thalassaemia syndromes. Concomitant co-inheritance with beta (beta) and delta (delta) gene abnormalities would result in improved clinical phenotype. We report here a 33-year-old male patient who was admitted with dengue haemorrhagic fever, with a background history of Grave's disease, incidentally noted to have mild hypochromic microcytic red cell indices. Physical examination revealed no thalassaemic features or hepatosplenomegaly. His full blood picture showed hypochromic microcytic red cells with normal haemoglobin (Hb) level. Quantitation of Hb using high performance liquid chromatography (HPLC) and capillary electrophoresis (CE) revealed raised Hb F, normal Hb A2 and Hb A levels. There was also small peak of Hb CS noted in CE. H inclusions was negative. Kleihauer test was positive with heterocellular distribution of Hb F among the red cells. DNA analysis for alpha globin gene mutations showed a single -alpha(-3.7) deletion and Hb CS mutation. These findings were suggestive of compound heterozygosity of Hb CS and a single -alpha(-3.7) deletion with a concomitant heterozygous deltabeta thalassaemia. Co-inheritance of Hb CS and a single -alpha(-3.7) deletion is expected to result at the very least in a clinical phenotype similar to that of two alpha genes deletion. However we demonstrate here a phenotypic modification of alpha thalassemia presumptively as a result of co-inheritance with deltabeta chain abnormality as suggested by the high Hb F level.
    Matched MeSH terms: Gene Deletion*
  8. Fulltext Two cases of deletion 5p syndrome: one with paternal involvement and another with atypical presentation
    Azman BZ, Akhir SM, Zilfalil BA, Ankathil R
    Singapore Med J, 2008 Apr;49(4):e98-e100.
    PMID: 18418516
    We report two cases of deletion 5p or cri du chat syndrome (CdCS) with different presentations and risks of transmission: one case with paternal chromosome 5 involvement and another, a de novo case with atypical clinical presentation. Cytogenetic analysis was performed on the two cases and their parents. GTG-banded karyotype analysis of Cases 1 and 2 revealed abnormal 46,XY,del(5)(p13-15) male karyotypes. For Case 1, the mother showed normal female karyotype while the father showed an abnormal karyotype involving a balanced translocation 46,XY,t(5;10)(p13;p15). For Case 2, however, both parents showed a normal karyotype pattern. In Case 1, the clinical features, particularly the distinct facial phenotype in combination with a characteristic cat-like cry and hypotonia, aided in the diagnosis at birth and the karyotype analysis was resolutive. The boy in Case 2 presented with atypical clinical features. Even though this patient had multiple syndromic features, the typical high pitched cat-like cry was not prominent. Instead, the patient manifested persistent stridor (from day three of life), which might have prevented the clinician from suspecting CdCS at birth. However, when this patient was presented at seven months of age for cytogenetic analysis, a confirmatory diagnosis of CdCS was established. For children with congenital abnormalities, an early clinical diagnosis confirmed through cytogenetic and molecular investigations, is important for providing personalised diagnostic and prognostic evaluation, and also for genetic counselling on the reproductive risk, particularly for patients with parental chromosome translocation involvement.
    Matched MeSH terms: Gene Deletion
  9. Fulltext Mowat-Wilson syndrome: the first two Malaysian cases
    Balasubramaniam S, Keng WT, Ngu LH, Michel LG, Irina G
    Singapore Med J, 2010 Mar;51(3):e54-7.
    PMID: 20428734
    Mowat-Wilson syndrome (MWS) is a recently delineated mental retardation; a multiple congenital anomaly syndrome characterised by a typical facial gestalt, Hirschsprung disease or severe constipation, genitourinary anomaly, congenital heart defects, agenesis of corpus callosum and eye defects. Some cases also present with epilepsy, growth retardation with microcephaly and speech impairment. MWS was first described in 1998 by Mowat et al, and approximately 180 cases have been reported as of August 2008. The syndrome occurs as a result of heterozygous mutations or deletions in the zinc finger E-box-binding homeobox 2 gene, ZEB2, previously called ZFHX1B (SIP1). Most cases reported so far were sporadic occurrences; however, rare cases of sibling recurrence have been cited. The facial phenotype is particularly important for the initial clinical diagnosis and provides the hallmark, warranting ZEB2 mutational analysis even in the absence of Hirschsprung disease. We present the first two molecularly confirmed Malaysian MWS patients, one of whom has a novel mutation.
    Matched MeSH terms: Gene Deletion
  10. Mitochondrial disorder, diabetes mellitus, and findings in three muscles, including the heart
    Bhattacharjee M, Venugopal B, Wong KT, Goto YI, Bhattacharjee MB
    Ultrastruct Pathol, 2006 Nov-Dec;30(6):481-7.
    PMID: 17183762
    The authors describe the case of a 50-year-old man with chronic progressive external ophthalmoplegia (CPEO), diabetes mellitus (DM), and coronary artery disease. The patient had no cardiac conduction abnormalities. During coronary artery bypass surgery, his heart and two skeletal muscles were biopsied. All three muscles showed ragged red fibers. The heart muscle showed significant glycogen accumulation. Analysis of mitochondrial DNA (mtDNA) showed a 5019-base-pair deletion, with no duplications. There were morphologically abnormal mitochondria in all 3 muscles, with clinically apparent difference in preservation of function. The combination of diabetes mellitus and mtDNA deletion is fortuitous, as they can be causally linked. The cardiac pathology allows speculation about the possible adaptive processes that may occur in the heart in DM. There are few reported cases with CPEO and excess glycogen in the heart. Most show deposition of fat and poorer clinical outcomes as compared to those with glycogen deposition. This observation may lend support to the hypothesis that in the myocardium, adaptive responses are mediated via changes in glucose handling, whereas alterations in fat metabolism likely represent maladaptation.
    Matched MeSH terms: Gene Deletion
  11. Fulltext Plasmodium falciparum isolate with histidine-rich protein 2 gene deletion from Nyala City, Western Sudan
    Boush MA, Djibrine MA, Mussa A, Talib M, Maki A, Mohammed A, et al.
    Sci Rep, 2020 07 30;10(1):12822.
    PMID: 32733079 DOI: 10.1038/s41598-020-69756-8
    In remote areas of malaria-endemic countries, rapid diagnostic tests (RDTs) have dramatically improved parasitological confirmation of suspected malaria cases, especially when skilled microscopists are not available. This study was designed to determine the frequency of Plasmodium falciparum isolates with histidine-rich protein 2 (pfhrp2) gene deletion as one of the possible factors contributing to the failure of PfHRP2-based RDTs in detecting malaria. A total of 300 blood samples were collected from several health centres in Nyala City, Western Sudan. The performance of PfHRP2-based RDTs in relation to microscopy was examined and the PCR-confirmed samples were investigated for the presence of pfhrp2 gene. A total of 113 out of 300 patients were P. falciparum positive by microscopy. Among them, 93.81% (106 out of 113) were positives by the PfHRP2 RDTs. Seven isolates were identified as false negative on the basis of the RDTs results. Only one isolate (0.9%; 1/113) potentially has pfhrp2 gene deletion. The sensitivity and specificity of PfHRP2-based RDTs were 93.81% and 100%, respectively. The results provide insights into the pfhrp2 gene deletion amongst P. falciparum population from Sudan. However, further studies with a large and systematic collection from different geographical settings across the country are needed.
    Matched MeSH terms: Gene Deletion*
  12. Fulltext Non-alcoholic fatty liver disease, vascular inflammation and insulin resistance are exacerbated by TRAIL deletion in mice
    Cartland SP, Harith HH, Genner SW, Dang L, Cogger VC, Vellozzi M, et al.
    Sci Rep, 2017 05 15;7(1):1898.
    PMID: 28507343 DOI: 10.1038/s41598-017-01721-4
    Non-alcoholic fatty liver disease (NAFLD) incorporates steatosis, non-alcoholic steato-hepatitis (NASH) and liver cirrhosis, associating with diabetes and cardiovascular disease (CVD). TNF-related apoptosis-inducing ligand (TRAIL) is protective of CVD. We aimed to determine whether TRAIL protects against insulin resistance, NAFLD and vascular injury. Twelve-week high fat diet (HFD)-fed Trail -/- mice had increased plasma cholesterol, insulin and glucose compared to wildtype. Insulin tolerance was impaired with TRAIL-deletion, with reduced p-Akt, GLUT4 expression and glucose uptake in skeletal muscle. Hepatic triglyceride content, inflammation and fibrosis were increased with TRAIL-deletion, with elevated expression of genes regulating lipogenesis and gluconeogenesis. Moreover, Trail -/- mice exhibited reduced aortic vasorelaxation, impaired insulin signaling, and >20-fold increased mRNA expression for IL-1β, IL-6, and TNF-α. In vitro, palmitate treatment of hepatocytes increased lipid accumulation, inflammation and fibrosis, with TRAIL mRNA significantly reduced. TRAIL administration inhibited palmitate-induced hepatocyte lipid uptake. Finally, patients with NASH had significantly reduced plasma TRAIL compared to control, simple steatosis or obese individuals. These findings suggest that TRAIL protects against insulin resistance, NAFLD and vascular inflammation. Increasing TRAIL levels may be an attractive therapeutic strategy, to reduce features of diabetes, as well as liver and vascular injury, so commonly observed in individuals with NAFLD.
    Matched MeSH terms: Gene Deletion*
  13. Genome-Wide Association for HbA1c in Malay Identified Deletion on SLC4A1 that Influences HbA1c Independent of Glycemia
    Chai JF, Kao SL, Wang C, Lim VJ, Khor IW, Dou J, et al.
    J Clin Endocrinol Metab, 2020 Dec 01;105(12).
    PMID: 32936915 DOI: 10.1210/clinem/dgaa658
    CONTEXT: Glycated hemoglobin A1c (HbA1c) level is used to screen and diagnose diabetes. Genetic determinants of HbA1c can vary across populations and many of the genetic variants influencing HbA1c level were specific to populations.

    OBJECTIVE: To discover genetic variants associated with HbA1c level in nondiabetic Malay individuals.

    DESIGN AND PARTICIPANTS: We conducted a genome-wide association study (GWAS) analysis for HbA1c using 2 Malay studies, the Singapore Malay Eye Study (SiMES, N = 1721 on GWAS array) and the Living Biobank study (N = 983 on GWAS array and whole-exome sequenced). We built a Malay-specific reference panel to impute ethnic-specific variants and validate the associations with HbA1c at ethnic-specific variants.

    RESULTS: Meta-analysis of the 1000 Genomes imputed array data identified 4 loci at genome-wide significance (P 

    Matched MeSH terms: Gene Deletion*
  14. Generation of monoclonal antibodies against Hong Kong nasopharyngeal carcinoma-associated Epstein-Barr virus latent membrane protein 1 (LMP1)
    Chan BC, To KF, Pang JC, Chung YF, Lo KW, Tong JH, et al.
    Int J Cancer, 2002 Dec 10;102(5):492-8.
    PMID: 12432552
    A panel of monoclonal antibodies specific to Hong Kong Chinese nasopharyngeal carcinoma (NPC)-associated Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) variants has been generated. These monoclonal antibodies not only differentiate the Hong Kong Chinese NPC-associated LMP1 variants from the prototype B95-8 LMP1, derived from Caucasian infectious mononucleosis, but also differentiate the 2 highly homologous LMP1 deletion variants commonly found in Hong Kong primary NPC. The predominant deletion type variant, DV-Asp335, is characterized by an aspartic acid at residue 335 located in the cytoplasmic C-terminal region, whereas the other minor deletion variant, DV-Gly335, has a glycine in the same residue position. 335D is hitherto found predominantly in LMP1 of the China 1 strain in association with NPC in the Chinese populations located in southern China and Malaysia. These antibodies, which are applicable in ELISA, immunofluorescence, immunoprecipitation, immunoblotting and immunohistochemistry on paraffin sections, are the first variant-specific anti-LMP1 monoclonal antibodies produced, and will be useful in investigating the functional significance of 335D in NPC.
    Matched MeSH terms: Gene Deletion
  15. Higher failures of amelogenin sex test in an Indian population group
    Chang YM, Burgoyne LA, Both K
    J Forensic Sci, 2003 Nov;48(6):1309-13.
    PMID: 14640276
    The human sex test in forensic multiplexes is based on the amelogenin gene on both the X and Y chromosomes commonly used in sex genotyping. In this study of 338 male individuals in a Malaysian population comprising Malays, Chinese and Indians, using the AmpFlSTR Profiler Plus kit, the amelogenin test gave a significant proportion of null alleles in the Indian ethnic group (3.6% frequency) and 0.88% frequency in the Malay ethnic group due to a deletion of the gene on the Y chromosome. This sex test also failed in a forensic casework sample. Failure of the amelogenin test highlights the need for more reliable sex determination than is offered by the amelogenin locus in the Malay and Indian populations. The gender of the Indian-Malay amelogenin nulls was confirmed by the presence of three Y-STR alleles (DYS438, DYS390 and DYS439). For the Indian ethnic group, one of the Y-STR forms a stable haplotype with the amelogenin null. The amelogenin-deletion individuals also showed a null with a male-specific minisatellite MSY1, indicating that a very large deletion was involved that included the amelogenin and the MSY1 loci on the short arm of the Y chromosomes (Yp).
    Matched MeSH terms: Gene Deletion
  16. Construction and characterization of rtxA and rtxC mutants of auxotrophic O139 Vibrio cholerae
    Cheong TG, Chan M, Kurunathan S, Ali SA, ZiNing T, Zainuddin ZF, et al.
    Microb Pathog, 2010 Feb;48(2):85-90.
    PMID: 19900531 DOI: 10.1016/j.micpath.2009.11.001
    Vibrio cholerae is a Gram-negative bacterium that causes diarrheal disease. V. cholerae O1 and O139 serogroups are toxigenic and are known to cause epidemic cholera. These serogroups produce cholera toxin and other accessory toxins such as accessory cholera enterotoxin, zonula occludens toxin, and multifunctional, autoprocessing repeat in toxin (MARTX). In the present study, we incorporated mutated rtxA and rtxC genes that encode MARTX toxin into the existing aminolevulinic acid (ALA) auxotrophic vaccine candidate VCUSM2 of V. cholerae O139 serogroup. The rtxC mutant was named VCUSM9 and the rtxC/rtxA mutant was named VCUSM10. VCUSM9 and VCUSM10 were able to colonize intestinal cells well, compared with the parent vaccine strain, and produced no fluid accumulation in a rabbit ileal loop model. Cell rounding and western blotting assays indicated that mutation of the rtxC gene alone (VCUSM9 strain) did not abolish MARTX toxicity. However mutation of both the rtxA and rtxC genes (VCUSM10) completely abolished MARTX toxicity. Thus we have produced a new, less reactogenic, auxotrophic rtxC/rtxA mutated vaccine candidate against O139 V. cholerae.
    Matched MeSH terms: Gene Deletion
  17. Fulltext Characterisation of Drosophila Ubx CPTI000601 and hth CPTI000378 protein trap lines
    Choo SW, Beh CY, Russell S, White R
    ScientificWorldJournal, 2014;2014:191535.
    PMID: 25389534 DOI: 10.1155/2014/191535
    In Drosophila, protein trap strategies provide powerful approaches for the generation of tagged proteins expressed under endogenous control. Here, we describe expression and functional analysis to evaluate new Ubx and hth protein trap lines generated by the Cambridge Protein Trap project. Both protein traps exhibit spatial and temporal expression patterns consistent with the reported endogenous pattern in the embryo. In imaginal discs, Ubx-YFP is expressed throughout the haltere and 3rd leg imaginal discs, while Hth-YFP is expressed in the proximal regions of haltere and wing discs but not in the pouch region. The Ubx (CPTI000601) line is semilethal as a homozygote. No T3/A1 to T2 transformations were observed in the embryonic cuticle or the developing midgut. The homozygous survivors, however, exhibit a weak haltere phenotype with a few wing-like marginal bristles on the haltere capitellum. Although hth (CPTI000378) is completely lethal as a homozygote, the hth (CPTI000378) /hth (C1) genotype is viable. Using a hth deletion (Df(3R)BSC479) we show that hth (CPTI000378) /Df(3R)BSC479 adults are phenotypically normal. No transformations were observed in hth (CPTI000378), hth (CPTI000378) /hth (C1), or hth (CPTI000378) /Df(3R)BSC479 embryonic cuticles. We have successfully characterised the Ubx-YFP and Hth-YFP protein trap lines demonstrating that the tagged proteins show appropriate expression patterns and produce at least partially functional proteins.
    Matched MeSH terms: Gene Deletion
  18. Fulltext Comparative chemical screening and genetic analysis reveal tentoxin as a new virulence factor in Cochliobolus miyabeanus, the causal agent of brown spot disease on rice
    De Bruyne L, Van Poucke C, Di Mavungu DJ, Zainudin NA, Vanhaecke L, De Vleesschauwer D, et al.
    Mol Plant Pathol, 2016 Aug;17(6):805-17.
    PMID: 26456797 DOI: 10.1111/mpp.12329
    Brown spot disease, caused by Cochliobolus miyabeanus, is currently considered to be one of the most important yield reducers of rice (Oryza sativa L.). Despite its agricultural importance, little is known about the virulence mechanisms deployed by the fungus. Therefore, we set out to identify novel virulence factors with a role in disease development. This article reports, for the first time, the production of tentoxin by C. miyabeanus as a virulence factor during brown spot disease and the identification of the non-ribosomal protein synthetase (NRPS) CmNps3, responsible for tentoxin biosynthesis. We compared the chemical compounds produced by C. miyabeanus strains differing in virulence ability using ultra-high-performance liquid chromatography (UHPLC) coupled to high-resolution Orbitrap mass spectrometry (HRMS). The production of tentoxin by a highly virulent strain was revealed by principal component analysis of the detected ions and confirmed by UHPLC coupled to tandem-quadrupole mass spectrometry (MS/MS). The corresponding NRPS was identified by in silico genome analysis and confirmed by gene deletion. Infection tests with wild-type and Cmnps3 mutants showed that tentoxin acts as a virulence factor and is correlated with chlorosis development during the second phase of infection. Although rice has previously been classified as a tentoxin-insensitive plant species, our data demonstrate that tentoxin production by C. miyabeanus affects symptom development.
    Matched MeSH terms: Gene Deletion
  19. Fulltext Nipah Virus Matrix Protein Influences Fusogenicity and Is Essential for Particle Infectivity and Stability
    Dietzel E, Kolesnikova L, Sawatsky B, Heiner A, Weis M, Kobinger GP, et al.
    J Virol, 2016 Mar;90(5):2514-22.
    PMID: 26676785 DOI: 10.1128/JVI.02920-15
    Nipah virus (NiV) causes fatal encephalitic infections in humans. To characterize the role of the matrix (M) protein in the viral life cycle, we generated a reverse genetics system based on NiV strain Malaysia. Using an enhanced green fluorescent protein (eGFP)-expressing M protein-deleted NiV, we observed a slightly increased cell-cell fusion, slow replication kinetics, and significantly reduced peak titers compared to the parental virus. While increased amounts of viral proteins were found in the supernatant of cells infected with M-deleted NiV, the infectivity-to-particle ratio was more than 100-fold reduced, and the particles were less thermostable and of more irregular morphology. Taken together, our data demonstrate that the M protein is not absolutely required for the production of cell-free NiV but is necessary for proper assembly and release of stable infectious NiV particles.
    Matched MeSH terms: Gene Deletion
  20. Fulltext The effects of angiotensin-converting enzyme gene polymorphism on the progression of immunoglobulin A nephropathy in Malaysian patients
    Draman CR, Kong NC, Gafor AH, Rahman AF, Zainuddin S, Mustaffa WM, et al.
    Singapore Med J, 2008 Nov;49(11):924-9.
    PMID: 19037561
    Angiotensin-converting enzyme (ACE) gene polymorphism, especially the deletion/deletion (DD) genotype, is associated with the disease progression of immunoglobulin A (IgA) nephropathy patients in various studies from both Asia Pacific and European populations. However, recent studies within the same populations were unable to reproduce the same results. Hence, we had studied the distribution of the DD genotype, the association between ACE gene polymorphism and the disease progression, and the factors (other than ACE gene polymorphism) which were involved in the disease progression of our local patients.
    Matched MeSH terms: Gene Deletion
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