1.Allelic frequencies of single nucleotide polymorphisms (SNPs) in the N-acetyltransferase 2 (NAT2) gene of Filipinos.
Autus-Geniston Leonora V. ; Matias Ronald R ; Tuazon Alexander O
Acta Medica Philippina 2010;44(3):18-23
OBJECTIVES:The present study aims to determine the frequency of occurrence of NAT2*4, NAT2*5A, NAT2*6B, NAT2*7A and NAT2*14A alleles by PCR-RFLP among Filipino volunteers. These alleles correspond to substitutions in the following sites: C341T, G590A, G857A and G191A, respectively, of the NAT2 gene. The presence of specific SNP combination was also used to deduce acetylation status and estimate genotype frequency and describe them in comparison with other populations based on literature.
METHODS: Genomic DNA from peripheral blood lymphocytes from 129 healthy Filipino volunteers was used to amplify the NAT2 gene segment. The RFLP analysis was done by restricting the expected PCR product with Kpn1, Taq1, BamH1 and Msp1/Al1, respectively, to detect the 4 alleles: NAT2*4, NAT2*5A, NAT2*6B, NAT2*7A and NAT2*14A.
RESULTS:The calculated allelic frequencies in Hardy-Weinberg equilibrium of NAT2*5A (C481T), NAT2*6B (G590A), NAT2*7A (G857A) and NAT2*14A (G191A) were 0.058, 0.097, 0.182 and 0.046, respectively. NAT2*4 had an allele frequency of 0.617. Nine genotypes were determined: NAT2*4/*4, NAT2*4/*5A, NAT2*4/*6B, NAT2*4/*7A, NAT2*4/*14A, NAT2*5A/*7A, NAT2*6B/*7A, NAT2*6B/*14A and NAT2*7A/*14A. From these genotypes, acetylator phenotypes were deduced. A trimodal pattern of distribution was established: rapid, intermediate and slow acetylators with the following percentages, 47.3%, 41.1 % and 11.6%. Among the slow acetylator SNPs determined, NAT2*7A was found as the most frequent allele and NAT2*14A was found as the least frequent allele.
CONCLUSION:The study showed the mutation profile and observed genotypic similarities and differences of Filipinos with other Asian populations and Americans and other Caucasians based on literature. The results also suggest a trimodal pattern of distribution of acetylators and lesser number of slow acetylators among Filipino populations, a characteristic similar to other Asian populations but significantly different from Americans and other Caucasians. The occurrence of NAT2*7A and NAT2*14A can be further sequenced to verify the observed genotype.
Human ; Male ; Female ; Aged ; Middle Aged ; Adult ; Young Adult ; Adolescent ; Acetylation ; Alleles ; Asian Continental Ancestry Group ; Base Sequence ; Dna ; Gene Frequency ; Genomics ; Genotype ; Lymphocytes ; Merozoite Surface Protein 1 ; Mutation ; Phenotype ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Polymorphism, Single Nucleotide ; United States ; Volunteers ; Genes ; Polymorphism, Genetic
2.Association of cholesteryl ester transfer protein (CETP) Taq1B polymorphism with response to simvastatin treatment in hypercholesterolemic Filipino patients.
Autus-Geniston Leonora V. ; Matias Ronald R. ; Vilela Gerald C. ; Tuazon Alexander O.
Acta Medica Philippina 2010;44(1):10-15
Although statins reduced cardiovascular mortality, these drugs did not prevent myocardial infarction in some patients. Previous studies showed that genetic variation in cholesteryl ester transfer protein (CETP) gene was linked to this response. The identified gene is characterized by two different variants: B1 and B2 alleles identified by the presence and absence, respectively, of a restriction site for the enzyme Taq1 in intron 1. The present study identified the variation in Taq1B of the gene using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) in 130 patients. An association study of Taq1B with the response of 24 middle-aged dyslipidemic patients to simvastatin treatment for 8 weeks was also done. The overall allele frequencies of B1 and B2 alleles were 0.548 and 0.462, respectively. The genotype frequencies were in Hardy-Weinberg equilibrium. The distinguishing feature of individuals with B1B1 genotype when treated with simvastatin was their rapid increase in high density lipoprotein (HDL) observed after 2 weeks which continued till the 8th week treatment. The expected HDL elevation among individuals with B1B2 genotype was observed only after the 8th week simvastatin treatment.
Human ; Middle Aged ; Alleles ; Cholesterol Ester Transfer Proteins ; Gene Frequency ; Genotype ; Hydroxymethylglutaryl-coa Reductase Inhibitors ; Introns ; Lipoproteins, Hdl ; Myocardial Infarction ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Simvastatin
3.Biomarker detection in urinary proteome of prostate cancer by nanoflow LC-MS/MS.
Autus-Geniston Leonora V ; Garcia Carlos P ; Ramos John Donnie A ; Tuazon Alexander O ; Estanislao Virgilio C
Acta Medica Philippina 2013;47(2):13-21
INTRODUCTION: Urinary proteomics provides a wealth of information in the identification of protein markers associated with various diseases such as in carcinoma. With the increasing incidence of prostate cancer and the lack of sensitivity and specificity of prostate specific antigen, the simultaneous identification of an alternative protein biomarker through urinary proteomics is encouraging. Urine, which has similar proteins with serum, makes it an ideal alternative biofluid wherein the collection is easy and non-invasive.
METHODS: Urinary proteins were separated by gradient SDS-PAGE followed by in-gel digestion and organic/buffer peptide extraction. The protein biomarkers in prostate cancer patients and control subjects were identified via LC-MS/MS and submitted to Protein Prospector where the peptide fragmentation of sequence was analyzed and compared with the SwissProt database.
RESULTS: A panel of three protein biomarkers for the early detection of prostate cancer were identified: transthyretin, hemoglobin subunit alpha and hemoglobin sububit beta. The presence of these three biomarkers is associated with high Gleason scores and TNM stages but not with PSA level. Uromodulin and mannan binding lectin serine protease cancer from BPH. The study also revealed the divergence of the urinary proteome of the cancer patients from the urinary proteome of the control with BPH suggesting the fundamental differences in benign and malignant growth of the prostate epithelial cells. Another highlight of the study was the identification of oxidation of pro63 of transthyretin in patient 3. The proposed role of the post translational modification in pro63 of transthyretinin in the mechanism of prostate carcinogenesis remains to be defined and warrants further study.
CONCLUSION: Our study was able to establish the homology of urine proteome among the controls and its divergence from the patients afflicted with prostate cancer by simultaneously comparing their urine proteomes leading to the identification of a distinct panel of biomarkers, namely, transthyretin, hemoglobin subunit alpha and hemoglobin subunit beta. Uromodulin and mannan binding lectin serine protease 2 are the additional biomarkers that can distinguish prostate cancer from BPH. Due to limitations in the number of controls and patients, only preliminary findings and their significance were shown. These findings need to be confirmed in future investigations using larger sample size for both the controls and the patients.
Human ; Male ; Prostate-specific Antigen ; Proteome ; Proteomics ; Prealbumin ; Uromodulin ; Serine Proteases ; Mannose-binding Lectin ; Prostatic Neoplasms ; Carcinogenesis ; Peptides ; Hemoglobins ; Epithelial Cells
4.Association of serum vitamin D levels, IL-17a Levels with disease severity among 3- to 18-year-old children with asthma in the Philippine General Hospital.
Kristine TANEGA-ALILING ; Alexander O. TUAZON
Acta Medica Philippina 2022;56(9):89-97
Background. Previous studies show that Vitamin D has an inverse relationship with asthma severity, symptoms, exacerbations, medication usage, and a direct relationship with lung function. IL-17A was found to be increased in asthmatics, which was inhibited by Vitamin D. Associations found between vitamin D, IL-17A, and asthma may support the future role of vitamin D in the treatment of asthma in children.
Objective. To compare vitamin D and IL-17A levels between children with and without asthma and determine their association with asthma severity
Study Design. Cross-sectional study
Methods. There were 44 participants, aged 3 to 18 years: 22 with asthma (12 non-severe, 10 severe) and 22 without asthma. Participants with any disease-altering vitamin D metabolism, intake of vitamin D supplementation, and recent infection were excluded. Serum vitamin D and IL-17A levels were measured in all participants.
Results. There was no significant difference in mean vitamin D levels between participants with asthma (29.6 ± 12.6 ng/mL) and without asthma (27.6 ± 9.5 ng/mL) (p = 0.55) as well as between participants with non-severe asthma (29.8 ± 14.0 ng/mL) and severe asthma (29.4 ± 11.5 ng/mL) (p = 0.95). The overall prevalence of hypovitaminosis D (< 30ng/mL) is 61.4%; 59.1% among those with asthma and 63.6% without asthma. The prevalence of vitamin D insufficiency and/or deficiency did not significantly differ between those with and without asthma (all p-value > 0.05); prevalence ratios were: 1.05 for vitamin D insufficiency, 0.58 for vitamin deficiency, and 0.92 for vitamin D insufficiency and deficiency combined. There was also no significant difference in the prevalence of vitamin D insufficiency and/or deficiency between severe and non-severe asthma (all p-values > 0.05), with prevalence ratios: 0.74 for vitamin D insufficiency, 0.50 for vitamin D deficiency, and 0.75 for vitamin D insufficiency and deficiency combined. Serum IL-17A levels were below the minimum detectable levels in 96% of the participants using the MILLIPLEX Map Human TH17 Magnetic Band Panel; hence, could not be analyzed.
Conclusion. The mean serum vitamin D levels do not differ between children with asthma and healthy controls. There was no significant relationship between mean vitamin D levels and asthma severity. There was no association between the prevalence of vitamin D insufficiency and/or deficiency and asthma and its severity. The overall prevalence of hypovitaminosis D in this study is 61.4%. Serum IL-17A levels were undetectable in 96% of the study population.
Asthma ; Vitamin D ; Interleukin-17
5.The yield of Acid-Fast Bacilli (AFB) and tuberculosis (TB) culture in the microbiologic diagnosis of childhood tuberculosis using sputum induction: A randomized controlled trial with interrupted time series.
Maria Cristina H. LOZADA ; Alexander O. TUAZON
Acta Medica Philippina 2022;56(5):128-135
Objectives: This study aims to determine the diagnostic yield and safety of sputum induction with hypertonic saline in the microbiologic confirmation of childhood tuberculosis (TB) in a tertiary hospital in the Philippines.
Methods: This is a randomized controlled trial with an interrupted time series in the control group. One hundred twelve (112) pediatric patients (4-18 years old) with clinical findings suggestive of TB were enrolled in the study. Patients were randomized into two groups composed of 56 patients each. Group A patients underwent sputum induction. Group B patients underwent spontaneous expectoration followed by sputum induction. The microbiologic yield for acid-fast bacilli and TB culture were determined and analyzed.
Results: Among the patients randomized to Group A, microbiologic confirmation for TB was 8/56 patients (14.3%) after sputum induction. For patients randomized to Group B, microbiologic yield was 4/56 patients (7.1%) from spontaneous expectoration; after sputum induction, the microbiologic yield increased to 5/56 patients (8.9%). There is insufficient evidence of statistical significance in microbiologic yield on parallel analysis of the two separate groups (p=0.22). Furthermore, for patients randomized to Group B, the increase in microbiologic yield after sputum induction compared to spontaneous expectoration did not reach statistical significance (p=1.000). The procedure was well-tolerated among children; no serious adverse events were observed.
Conclusion: Sputum induction is a feasible and safe method of specimen collection for microbiologic diagnosis of TB among children. While the microbiologic yield increased after sputum induction compared to spontaneous expectoration, the additional yield does not seem to be significant.
Tuberculosis ; Child