CASE PRESENTATION: A 60-year-old Malay gentleman presented to the Periodontic Clinic, Universiti Kebangsaan Malaysia. He was a known case of primary PRV for the past 5 years. Intraoral examination showed generalized periodontal deep pockets ranging from 5 to 10 mm. He was diagnosed as Stage III Grade C periodontitis. Nonsurgical periodontal therapy was provided, followed by surgical correction of residual periodontal deep pockets on teeth 17, 11, and 23. He was reviewed at 4-month intervals for supportive periodontal therapy after stabilization of his periodontal condition.
CONCLUSION: Polycythemia rubra vera (PRV) patients should have preoperative therapeutic control for more than 4 months and have been treated with myelosuppressive agents prior to periodontal surgery. Good oral hygiene and periodical supportive periodontal therapy are the key factors for successful periodontal treatment outcomes in well-controlled PRV patients.
RESULTS: In the erythrocyte-binding assay, binding level was determined by scoring the number of rosettes that were formed by erythrocytes surrounding transfected mammalian COS-7 cells which expressed PkDBPαII. The assay result revealed a significant difference in the binding level. The number of rosettes scored for Fya+/b+ was 1.64-fold higher than that of Fya+/b- (155.50 ± 34.32 and 94.75 ± 23.16 rosettes, respectively; t(6) = -2.935, P = 0.026).
CONCLUSIONS: The erythrocyte-binding assay provided a simple approach to quantitatively determine the binding level of PkDBPαII to the erythrocyte Duffy antigen. Using this assay, PkDBPαII was found to display higher binding to Fya+/b+ erythrocytes than to Fya+/b- erythrocytes.
METHODS: In order to investigate the efficacy of pre-clinical vaccine candidates in P. knowlesi-infected human cases, this study describes an in vitro invasion inhibition assay, using a P. knowlesi strain adapted to in vitro growth in human erythrocytes, PkA1-H.1. Recombinant proteins of P. knowlesi Duffy binding protein alpha (PkDBPα) and apical membrane antigen 1 (PkAMA1) were produced in Escherichia coli system and rabbit antibodies were generated from immune animals.
RESULTS: PkDBPα and PkAMA1 recombinant proteins were expressed as insoluble and produced as a functional refolded form for this study. Antibodies against PkDBPα and PkAMA1 specifically recognized recombinant proteins and native parasite proteins in schizont-stage parasites on the merozoite organelles. Single and combination of anti-PkDBPα and anti-PkAMA1 antibodies elicited strong growth inhibitory effects on the parasite in concentration-dependent manner. Meanwhile, IgG prevalence of PkDBPα and PkAMA1 were observed in 13.0 and 46.7% in human clinical patients, respectively.
CONCLUSION: These data provide support for the validation of in vitro growth inhibition assay using antibodies of DBPα and AMA1 in human-adapted P. knowlesi parasite PkA1-H.1 strain.
METHODS: Blood samples from 78 knowlesi malaria patients were used. Forty-eight of the samples were from Peninsular Malaysia, and 30 were from Malaysia Borneo. The genomic DNA of the samples was extracted and used as template for the PCR amplification of the PkγRII. The PCR product was cloned and sequenced. The sequences obtained were analysed for genetic diversity and natural selection using MEGA6 and DnaSP (version 5.10.00) programmes. Genetic differentiation between the PkγRII of Peninsular Malaysia and North Borneo isolates was estimated using the Wright's FST fixation index in DnaSP (version 5.10.00). Haplotype analysis was carried out using the Median-Joining approach in NETWORK (version 184.108.40.206).
RESULTS: A total of 78 PkγRII sequences was obtained. Comparative analysis showed that the PkγRII have similar range of haplotype (Hd) and nucleotide diversity (π) with that of PkDBPαRII. Other similarities between PkγRII and PkDBPαRII include undergoing purifying (negative) selection, geographical clustering of haplotypes, and high inter-population genetic differentiation (FST index). The main differences between PkγRII and PkDBPαRII include length polymorphism and no departure from neutrality (as measured by Tajima's D statistics) in the PkγRII.
CONCLUSION: Despite the biological difference between PkγRII and PkDBPαRII, both generally have similar genetic diversity level, natural selection, geographical haplotype clustering and inter-population genetic differentiation index.
OBJECTIVES: The objectives of this study were to investigate the CELSR3 hypermethylation level in oral squamous cell carcinomas (OSCCs) using methylation-sensitive high-resolution melting analysis (MS-HRM) and to correlate CELSR3 methylation with patient demographic and clinicopathological parameters.
MATERIALS AND METHODS: Frozen tissue samples of healthy subjects' normal mucosa and OSCCs were examined with regard to their methylation levels of the CELSR3 gene using MS-HRM.
RESULTS: MS-HRM analysis revealed a high methylation level of CELSR3 in 86% of OSCC cases. Significant correlations were found between CELSR3 quantitative methylation levels with patient ethnicity (P=0.005), age (P=0.024) and pathological stages (P=0.004). A moderate positive correlation between CELSR3 and patient age was also evident (R=0.444, P=0.001).
CONCLUSIONS: CELSR3 promoter hypermethylation may be an important mechanism involved in oral carcinogenesis. It may thus be used as a biomarker in OSCC prognostication.