ASEAN Neurology Association (ASNA) consists of 9 member countries, Brunei, Indonesia, Lao, Malaysia, Myanmar, Philippines, Singapore, Thailand and Vietnam. Among them 2 countries are considered lower middle income, 4 as upper middle income, and 3 as high income by World Bank criteria. The life expectancy is above 75 years in Brunei and Singapore, below 60 years in Lao and Myanmar. There are a total of 1,871 neurologists in ASNA member countries which has a total of 540 million populations. This constitutes 2.2% of the world neurologists, although ASNA member countries accounts for 8.3% of the world population. Myanmar and Lao in particular, has lowest ratio of neurologist, with one neurologist serving 5 million populations in Myanmar, and 2 million populations in Lao.
Myanmar ; member ; Neurology ; Income ; Neurologist

OBJECTIVE: To express and purify NR4A1-DNA binding domain (DBD) protein of nuclear receptors. METHODS: The fusion protein PET28a-NR4A1-DBD was constructed and purified with the nickel affinity chromatography, cation-exchange chromatography and gel filtration chromatography. RESULTS: The protein PET28a-NR4A1-DBD was mostly soluable at 24 °C. A total of 2-3 mg/L pure NR4A1 proteins were yielded in bacterial culture and the purity for final fractions of NR4A1-DBD protein were great than 95% by SDS-PAGE analysis. CONCLUSION Nickel affinity chromatography is effective to purify protein. The protein purity can be further improved by the following methods including cation-exchange chromatography and gel filtration chromatography.
Electrophoresis, Polyacrylamide Gel ; Nuclear Receptor Subfamily 4, Group A, Member 1 ; chemistry ; Recombinant Fusion Proteins ; chemistry

OBJECTIVE: To detect pathological variants of the SLC12A3 gene in a Chinese pedigree affected with Gitelman syndrome (GS). METHODS: Clinical data and peripheral blood samples of the proband and his family members were collected. All exons of the SLC12A3 gene were amplified by PCR and subjected to Sanger sequencing. RESULTS: Sanger sequencing has revealed that the proband has carried a c.486_489 delTACG (p.Ile162Met fs*8) deletion and a heterozygous c.2890C>T (p.Arg964Trp) missense variant in the SLC12A3 gene. Neither variant was reported previously and was not found among healthy controls. CONCLUSION The c.486_489delTACG (p.Ile162Met fs*8) and c.2890C>T (p.Arg964Trp) variants of the SLC12A3 gene probably underlay the GS in the proband. Above discovery has enriched the variant spectrum of GS.
China ; Gitelman Syndrome/genetics* ; Heterozygote ; Humans ; Mutation/genetics* ; Pedigree ; Solute Carrier Family 12, Member 3/genetics*

Antibodies, Neutralizing ; Apoptosis ; Hep G2 Cells ; Humans ; Receptors, Tumor Necrosis Factor, Member 6b ; immunology ; metabolism

This study was aimed to investigate the distribution and implication of tap1 (transporter associated with antigen processing) and tap2 loci allelic and genotypic frequencies. The distribution of tap1 and tap2 loci allelic and genotypic frequencies in 339 random samples of healthy Chinese Hans was analyzed by TaqMan PCR. Several genetic information about power of discrimination, cumulative DP, polymorphism information content, expected heterozygosity and observed heterozygosity were calculated. The results indicated that 5 tap1 alleles (tap1*0101, 020101, 020102, 0301 and 0401) and 4 tap2 alleles (tap2*0101, 0102, 0103 and 0201) were detected in all samples. 8 tap1 genotypes were found which account for 53.3% of the theoretic genotype and 6 tap2 genotypes were found which account for 60% of the theoretic genotype. The genotyping results of tap1 and tap2 both conform to the Hardy-Weinberg expectations (p > 0.05). Tap1*0101 (79.79%) and tap2*0101 (82.74%) are the most common alleles in Chinese Hans. It is concluded that tap1*0101 and tap2*0101 are most common alleles in Chinese Hans, tap1 and tap2 loci carry some power of individual discrimination and polymorphism information content. These two locl can be used for the research in the fields of human genetics, linkage analysis of genetic disease genes, paternity test and individual identification and so on.
ATP-Binding Cassette Sub-Family B Member 2 ; ATP-Binding Cassette Transporters ; genetics ; ATP-Binding Cassette, Sub-Family B, Member 3 ; Alleles ; Asian Continental Ancestry Group ; genetics ; Gene Frequency ; Genotype ; Haplotypes ; Humans

Gitelman's syndrome is an autosomal recessive disorder characterized by hypokalemic metabolic alkalosis, hypomagnesemia, and hypocalciuria that has recently been reported to be linked to thiazide-sensitive Na-Cl cotransporter gene mutation. In this study, we performed renal clearance studies to differentiate Gitelman's from Bartter's syndrome and to confirm the diagnosis in two patients clinically diagnosed with Gitelman's syndrome. Each patient was hydrated by 20 mL/kg body weight of oral water within 30 minutes, which was followed by intravenous half saline. When urinary flow reached 10 mL/min, samples of urine and serum were obtained to calculate the osmolar clearance, free water clearance, chloride clearance, and distal fractional chloride reabsorption. Subsequently, furosemide or hydrochlorothiazide was administered. Samples were collected and the same parameters were calculated. In our patients, chloride clearance was increased more than 10 times after furosemide administration(2.1:25.7 and 2.2:27.4 mL/min/100 mL GFR), but not increased after hydrochlorothiazide treatment(2.1:1.6 and 2.2:2.6 mL/min/100 mL GFR). And the distal fractional chloride reabsorption was significantly decreased by furosemide injection (73%:15% and 75%:4.6%), whereas hydrochlorothiazide had no effect on it(73%:63% and 75%:78%). These findings indicate that our patients have a defect in thiazide-sensitive Na-Cl cotransporter in the distal tubule, which is compatible with the pathophysiology of Gitelman's syndrome.
Alkalosis ; Bartter Syndrome ; Body Weight ; Diagnosis ; Furosemide ; Gitelman Syndrome* ; Humans ; Hydrochlorothiazide ; Solute Carrier Family 12, Member 3 ; Water

OBJECTIVES: Hypoxia can alter the oral bioavailability of drugs, including various substrates (drugs) of P-glycoprotein (P-gp), suggesting that hypoxia may affect the function of P-gp in intestinal epithelial cells. Currently, Caco-2 monolayer model is the classic model for studying the function of intestinal epithelial P-gp. This study combines the Caco-2 monolayer model with hypoxia to investigate the effects of hypoxia on the expression and function of P-gp in Caco-2 cells, which helps to elucidate the mechanism of changes in drug transport on intestinal epithelial cells in high-altitude hypoxia environment. METHODS: Normally cultured Caco-2 cells were cultured in 1% oxygen concentration for 24, 48, and 72 h, respectively. After the extraction of the membrane proteins, the levels of P-gp were measured by Western blotting. The hypoxia time, with the most significant change of P-gp expression, was selected as the subsequent study condition. After culturing Caco-2 cells in transwell cells for 21 days and establishing a Caco-2 monolayer model, they were divided into a normoxic control group and a hypoxic group. The normoxic control group was continuously cultured in normal condition for 72 h, while the hypoxic group was incubated for 72 h in 1% oxygen concentration. The integrity and polarability of Caco-2 cells monolayer were evaluated by transepithelial electrical resistance (TEER), apparent permeability (Papp) of lucifer yellow, the activity of alkaline phosphatase (AKP), and microvilli morphology and tight junction structure under transmission electron microscope. Then, the Papp of rhodamine 123 (Rh123), a kind of P-gp specific substrate, was detected and the efflux rate was calculated. The Caco-2 cell monolayer, culturing at plastic flasks, was incubated for 72 h in 1% oxygen concentration, the expression level of P-gp was detected. RESULTS: P-gp was decreased in Caco-2 cells with 1% oxygen concentration, especially the duration of 72 h (P<0.01). In hypoxic group, the TEER of monolayer was more than 400 Ω·cm², the Papp of lucifer yellow was less than 5×10^-7 cm/s, and the ratio of AKP activity between apical side and basal side was greater than 3. The establishment of Caco-2 monolayer model was successful, and hypoxia treatment did not affect the integrity and polarization state of the model. Compared with the normoxic control group, the efflux rate of Rh123 was significantly reduced in Caco-2 cell monolayer of the hypoxic group (P<0.01). Hypoxia reduced the expression of P-gp in Caco-2 cell monolayer (P<0.01). CONCLUSIONS Hypoxia inhibits P-gp function in Caco-2 cells, which may be related to the decreased P-gp level.
Humans ; ATP Binding Cassette Transporter, Subfamily B, Member 1 ; Caco-2 Cells ; ATP Binding Cassette Transporter, Subfamily B ; Hypoxia ; Oxygen

OBJECTIVES: Primary carnitine deficiency (PCD) is a rare fatty acid metabolism disorder that can cause neonatal death. This study aims to analyze carnitine levels and detect SLC22A5 gene in newborns with carnitine deficiency, to provide a basis for early diagnosis of PCD, and to explore the relationship between carnitine in blood and SLC22A5 genotype. METHODS: A total of 40 neonates with low free carnitine (C0<10 μmol/L) in blood were the subjects of the study. SLC22A5 gene was detected by Sanger sequencing to analyze the value of carnitine, the results of gene test and their relationship. RESULTS: A total of 15 variants of SLC22A5 gene were detected, including 11 pathogenic or likely pathogenic variants and 4 variants of uncertain significance. There were 5 new mutations: c.288delG (p.G96fsX33), c.744_745insTCG (p.M258_L259insS), c.752A>G (p.Y251C), c.495 C>A (p.R165E), and c.1298T>C (p.M433T). We found 14 PCD patients including 2 homozygous mutations and 12 heterozygous mutations, 14 with 1 mutation, and 12 with no mutation among 40 children. The C0 concentration of children with SLC22A5 gene homozygous or complex heterozygous mutations was (4.95±1.62) μmol/L in the initial screening, and (3.90±1.33) μmol/L in the second screening. The C0 concentration of children with no mutation was (7.04±2.05) μmol/L in the initial screening, and (8.02±2.87) μmol/L in the second screening. There were significant differences between children with homozygous or compound heterozygous mutations and with no mutation in C0 concentration of the initial and the second screening (both CONCLUSIONS There are 5 new mutations which enriched the mutation spectrum of SLC22A5 gene. C0<5 μmol/L is highly correlated with SLC22A5 gene homozygous or compound heterozygous mutations. Children with truncated mutation may have lower C0 concentration than that with untruncated mutation in the initial screening.
Cardiomyopathies ; Carnitine/deficiency* ; Child ; Humans ; Hyperammonemia/genetics* ; Infant, Newborn ; Muscular Diseases/genetics* ; Mutation ; Solute Carrier Family 22 Member 5/genetics*

OBJECTIVE: To analyze the blood free carnitine (C0) level and SLC22A5 gene variants in 17 neonates with Primary carnitine deficiency (PCD) and to determine its incidence in local area and explore the correlation between C0 level and genotype. METHODS: 148 043 newborns born in 9 counties (cities and districts) of Ningde city from September 2016 to June 2021 were selected as study subjects. Blood free carnitine and acyl carnitine of 148 043 neonates were analyzed. Variants of the SLC22A5 gene were screened in those with blood C0 < 10 µmol/L, or C0 between 10 ∼ 15 µmol/L. Correlation between the free carnitine level and genetic variants was analyzed. RESULTS: In total 17 neonates were diagnosed with PCD, which yielded a prevalence of 1/8 707 in the region. Twelve variants of the SLC22A5 gene were identified, with the common ones including c.760C>T, c.1400C>G and c.51C>G. Compared with those carrying other variants of the gene, children carrying the c.760C>T variant had significantly lower C0 values (P < 0.01). CONCLUSION The prevalence of PCD is relatively high in Ningde area, and intervention measures should be taken to prevent and control the disease. The c. 760C>T variant is associated with lower level of C0, which can provide a clue for the diagnosis.
Humans ; Infant, Newborn ; Cardiomyopathies/diagnosis* ; Carnitine ; Hyperammonemia/diagnosis* ; Muscular Diseases/genetics* ; Solute Carrier Family 22 Member 5/genetics*

Two patients with Gitelman syndrome were admitted to the Department of Endocrinology, Third Xiangya Hospital of Central South University. The genomic DNA from the patients' peripheral blood was extracted and the whole-exome sequencing was performed to detect the possible mutations. The function of the mutation sites was analyzed by bioinformatics software. Through whole-exome sequencing and Sanger sequencing, we have found that 2 patients with Gitelman syndrome carried compound heterozygous mutations of SLC12A3 gene, which were c.486_490delTACGGinsA, p.R943W, p.D486N, and p.R928C. Among them, c.486_490delTACGGinsA insertion deletion mutation causes frame shift and protein truncation. The p.R943W, p.D486N, and p.R928C of SLC12A3 gene were predicted to be pathogenic mutations by SIFT, PolyPhen2, and Mutation Taster. These 4 mutations were all reported, but p.R943W was first reported in Chinese population. Gitelman syndrome is rare in clinic and the rate of missed diagnosis is high. Early genetic analysis in patients with Gitelman syndrome is helpful to determine the etiology and guide the treatment.
Genetic Testing ; Gitelman Syndrome/genetics* ; Humans ; Mutation ; Pedigree ; Solute Carrier Family 12, Member 3/genetics* ; Whole Exome Sequencing