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The Ok(a) blood group antigen basigin (BSG or CD147) is an erythrocyte receptor for the PfRh5 protein from Plasmodium falciparum. A recent study has shown that the PfRh5-BSG interaction is essential for erythrocyte invasion by P. falciparum. In this study, 6 SNPs in the BSG gene were investigated in 312 adult patients with P. falciparum malaria (109 cerebral malaria and 203 mild malaria patients) living in northwest Thailand. To examine the association between BSG SNPs and cerebral malaria, the allele and haplotype frequencies were compared in cerebral and mild malaria patients. Nonsynonymous SNPs were not assessed in the association analysis. The results showed that common BSG polymorphisms and haplotypes were not significantly associated with cerebral malaria. In conclusion, common SNPs in BSG do not influence the risk of cerebral malaria in the Thai population.

Disrupted-in-Schizophrenia-1 (DISC1) , identified by cytogenetic approaches in a pedigree with familial psychosis, is considered a candidate susceptibility gene for schizophrenia in some populations. In the pedigree, the TRAX gene, located adjacent to DISC1 on the disrupted chromosome 1, may also contribute to the pathophysiology of the familial schizophrenia. We studied association of the DISC1 and TRAX genes with schizophrenia in 338 Japanese by analyzing 15 single nucleotide polymorphisms (SNPs), including 12 SNPs in DISC1 and three in TRAX , respectively. No significant difference was observed between the patients and controls in allelic frequencies or genotypic distributions of 15 SNPs. A weak trend for the association in genotypic distribution of one SNP in TRAX (major homo/hetero/minor homo: 0.324/0.431/0.245 vs. 0.293/0.526/0.181 for patients vs controls, p = 0.039 in the 2 × 3 comparison) turned out to be insignificant after Bonferroni correction. Haplotype analysis did not support the association between the patients and controls. The present study suggests that the DISC1/TRAX locus may not have a major role in Japanese schizophrenia.

Association studies using linkage disequilibrium (LD) between candidate loci and nearby markers have been proposed to identify susceptibility genes for complex diseases. We analyzed polymorphisms of microsatellites (MSs) and LD patterns of the regions in which candidate genes related to the Th1 immune response have been annotated and attempted to identify a susceptibility gene for sarcoidosis in a marker-based association study. Nineteen MSs were identified in six Th1-related genes (IFNGR1, IFNGR2, IL12RB1, IL12RB2, STAT1 and STAT4) and then eight were further characterized as useful polymorphic markers. Most of these MSs showed LD with single nucleotide polymorphisms (SNPs) on both 5' and 3' ends of these candidate genes, in which r(2) values between at least one of the MS marker alleles and the SNPs were higher than 0.1. A significant association with one MS allele near STAT4 was shown and a cluster of SNPs in LD with the MS marker was associated with sarcoidosis. These results suggest that association studies using not only SNPs but also multi-allelic MS within or near candidate loci would be useful markers to search for a disease susceptibility gene, especially in populations with unknown LD structure.

In order to investigate polymorphic backgrounds of the cystic fibrosis transmembrane conductance regulator gene (CFTR) in the Vietnamese, we analyzed 495 blood samples of randomly selected healthy individuals in Hanoi for the delta F508 mutation and TG-repeats, poly-T, and M470V polymorphisms. We compared their distributions with those of Caucasians and other Asian populations. No delta F508 mutation was found, being consistent with the extremely low incidence of cystic fibrosis (CF) in Vietnam. Allele frequency of the T5 allele promoting exon 9 skipping was 0.037. Greater number of TG-repeats, which is known to facilitate this aberrant splicing, was a predominant trend in the Vietnamese and other Asians. A "T5-TG12-V470" haplotype was most common (29/37) among T5-bearing haplotypes. Three major haplotypes, T7-TG12-M470, T7-TG11-V470, and T7-TG12-V470, estimated by PHASE program, related to 92% of the population. This is the first study of the CFTR gene among the Vietnamese.

A binding site for the repressor protein BP1, which contains a tandem (AT)x(T)y repeat, is located approximately 530 bp 5' to the human beta-globin gene (HBB). There is accumulating evidence that BP1 binds to the (AT)9(T)5 allele more strongly than to other alleles, thereby reducing the expression of HBB. In this study, we investigated polymorphisms in the (AT)x(T)y repeat in 57 individuals living in Thailand, including three homozygotes for the hemoglobin E variant (HbE; beta26Glu--Lys), 22 heterozygotes, and 32 normal homozygotes. We found that (AT)9(T)5 and (AT)7(T)7 alleles were predominant in the studied population and that the HbE variant is in strong linkage disequilibrium with the (AT)9(T)5 allele, which can explain why the betaE chain is inefficiently synthesized compared to the normal betaA chain. Moreover, the mildness of the HbE disease compared to other hemoglobinopathies in Thai may be due, in part, to the presence of the (AT)9(T)5 repeat on the HbE chromosome. In addition, a novel (AC)n polymorphism adjacent to the (AT)x(T)y repeat (i.e., (AC)3(AT)7(T)5) was found through the variation screening in this study.

We previously reported association of FCGR2B-Ile232Thr with systemic lupus erythematosus (SLE) in three Asian populations. Because polymorphism of CD72, another inhibitory receptor of B cells, was associated with murine SLE, we identified human CD72 polymorphisms, tested their association with SLE and examined genetic interaction with FCGR2B in the Japanese (160 SLE, 277 controls), Thais (87 SLE, 187 controls) and Caucasians (94 families containing SLE members). Four polymorphisms and six rare variations were detected. The former constituted two major haplotypes that contained one or two repeats of 13 nucleotides in intron 8 (designated as *1 and *2, respectively). Although association with susceptibility to SLE was not detected, the *1 allele was significantly associated with nephritis among the Japanese patients (P=0.024). RT-PCR identified a novel alternatively spliced (AS) transcript that was expressed at the protein level in COS-7 transfectants. The ratio of AS/common isoforms was strikingly increased in individuals with *2/*2 genotype when compared with *1/*1 (P=0.000038) or *1/*2 (P=0.0085) genotypes. Using the two Asian cohorts, significant association of FCGR2B-232Thr/Thr with SLE was observed only in the presence of CD72-*1/*1 genotype (OR 4.63, 95% CI 1.47-14.6, P=0.009 versus FCGR2B-232Ile/Ile plus CD72-*2/*2). Minigene assays demonstrated that the 13-nucleotide repeat and 4 bp deletion within the same haplotype of intron 8 could regulate alternative splicing. The AS isoform lacks exon 8, and is deduced to contain 49 amino acid changes in the membrane-distal portion of the extracellular domain, where considerable amino acid changes are known in CD72(c) allele associated with murine SLE. These results indicated that the presence of CD72-*2 allele decreases risk for human SLE conferred by FCGR2B-232Thr, possibly by increasing the AS isoform of CD72.

We have hypothesized that genetic predisposition influences the progression of SARS. Angiotensin converting enzyme (ACE1) insertion/deletion (I/D) polymorphism was previously reported to show association with the adult respiratory distress syndrome, which is also thought to play a key role in damaging the lung tissues in SARS cases. This time, the polymorphism was genotyped in 44 Vietnamese SARS cases, with 103 healthy controls who had had a contact with the SARS patients and 50 controls without any contact history. SARS cases were divided into either non-hypoxemic or hypoxemic groups. Despite the small sample size, the frequency of the D allele was significantly higher in the hypoxemic group than in the non-hypoxemic group (p = 0.013), whereas there was no significant difference between the SARS cases and controls, irrespective of a contact history. ACE1 might be one of the candidate genes that influence the progression of pneumonia in SARS.

Haplotype-based human genome research is important in identifying disease susceptibility genes efficiently. Although haplotype reconstruction by statistical methods is widely used, direct haplotype determination by molecular techniques has also been developed as a complementary method for statistical estimation. In this study, we demonstrate a molecular haplotyping method making use of single-strand conformation polymorphism (SSCP) gels. We identified 10 common SNPs and a dinucleotide insertion/deletion polymorphism within 2-kb region upstream of the transcription initiation site of MUC5B and determined haplotype structure, dividing the region into two DNA fragments. Real haplotypes were determined unambiguously by our SSCP-based analysis with fragments longer than 1 kb. Haplotypes reconstructed from diploid genotypes in the same region by the statistical methods including EM algorithm were also evaluated. Direct comparison between statistical estimation and direct determination of haplotypes revealed that major haplotypes containing multiple marker sites showing strong LD are estimated in great accuracy but that a variety of haplotypes reflecting weak LD are not reconstructed precisely enough. Our data can be helpful in implementing molecular haplotyping or statistical estimation, since usage of these methods may be determined depending on the haplotype structures.

In some herpes zoster patients, pain persists for more than 3 months or more after healing of vesicular eruptions; this condition is termed postherpetic neuralgia (PHN). We have recently reported the association of the human histocompatibility leukocyte antigens (HLA) haplotype, HLA-A*3303-B*4403-DRB1*1302 with PHN patients; however, it has not been determined whether the haplotype is also associated with herpes zoster that did not develop subsequent PHN. To distinguish whether the haplotype is associated with herpes zoster or the development of PHN, we examined if herpes zoster patients without subsequently PHN are also associated with the HLA haplotype or not. Herpes zoster patients were followed up for more than 6 months, and HLA alleles and haplotypes were compared among the PHN patients ( n =52), the herpes zoster patients who did not develop PHN ( n =42) and healthy controls ( n =125). The frequencies of the risk haplotype in the PHN patients, in the healthy controls and in the herpes zoster patients without subsequent PHN were 16.3, 5.2 and 4.8%, respectively. While the frequency of the risk haplotype was significantly higher in the PHN patients than in the healthy controls ( P =0.0006), no difference was observed between the herpes zoster patients without subsequent PHN and the healthy controls. No significant association was found between the duration of symptoms or the site of herpes zoster and the HLA alleles and the haplotype. These results suggest that the HLA-A*3303-B*4403-DRB1*1302 haplotype plays an important role in the development of PHN after herpes zoster, but not in the onset of herpes zoster.

The hemoglobin E variant (HbE; ( beta )26Glu--Lys) is concentrated in parts of Southeast Asia where malaria is endemic, and HbE carrier status has been shown to confer some protection against Plasmodium falciparum malaria. To examine the effect of natural selection on the pattern of linkage disequilibrium (LD) and to infer the evolutionary history of the HbE variant, we analyzed biallelic markers surrounding the HbE variant in a Thai population. Pairwise LD analysis of HbE and 43 surrounding biallelic markers revealed LD of HbE extending beyond 100 kb, whereas no LD was observed between non-HbE variants and the same markers. The inferred haplotype network suggests a single origin of the HbE variant in the Thai population. Forward-in-time computer simulations under a variety of selection models indicate that the HbE variant arose 1,240-4,440 years ago. These results support the conjecture that the HbE mutation occurred recently, and the allele frequency has increased rapidly. Our study provides another clear demonstration that a high-resolution LD map across the human genome can detect recent variants that have been subjected to positive selection.

A number of archeological, linguistic, and genetic studies have been carried out on the peopling of the Pacific, while the origin of Polynesians or the Lapita people is still open to debate. The Lapita people are believed to have populated the Bismarck Archipelago more than 3600 years ago. However, their Melanesian descendants still living in the Bismarck Archipelago have not been genetically clarified yet. To address this question, polymorphism of the ABO blood group gene was investigated in the following three populations who are considered to be almost free from recent admixtures: (i) Balopa islanders as Austronesian (AN)-speaking Melanesians living in the northwestern end of the Bismarck Archipelago; (ii) Gidra as non-Austronesian (NAN)-speaking Melanesians in southwestern lowlands of Papua New Guinea; and (iii) Tongan living in Ha'apai island as AN-speaking Polynesians. Interestingly, there were marked differences in allele frequencies of ABO*A101 and ABO*A102 among the three populations. The allele frequencies of ABO*A101 and ABO*A102 were 7.9 and 19.3% in Balopa, 23.2 and 0.0% in Gidra, and 2.9 and 25.0% in Tongan. Both phylogenetic and correspondence analyses suggested that Balopa was more close to Tongan than to Gidra and that Balopa was genetically placed between Tongan and Asian populations. Our results imply that Balopa may be Melanesian descendants of the Lapita people who populated the Bismarck Archipelago.

Natural killer (NK) cell-type lymphoproliferative disease of granular lymphocytes (LDGL) is characterized by the outgrowth of CD3(-)CD16/56(+) NK cells, and can be further subdivided into two distinct categories: aggressive NK cell leukemia (ANKL) and chronic NK lymphocytosis (CNKL). To gain insights into the pathophysiology of NK cell-type LDGL, we here purified CD3(-)CD56(+) fractions from healthy individuals (n=9) and those with CNKL (n=9) or ANKL (n=1), and compared the expression profiles of >12 000 genes. A total of 15 'LDGL-associated genes' were identified, and a correspondence analysis on such genes could clearly indicate that LDGL samples share a 'molecular signature' distinct from that of normal NK cells. With a newly invented class prediction algorithm, 'weighted distance method', all 19 samples received a clinically matched diagnosis, and, furthermore, a detailed cross-validation trial for the prediction of normal or CNKL status could achieve a high accuracy (77.8%). By applying another statistical approach, we could extract other sets of genes, expression of which was specific to either normal or LDGL NK cells. Together with sophisticated statistical methods, gene expression profiling of a background-matched NK cell fraction thus provides us a wealth of information for the LDGL condition.

We examined a possible association of single-nucleotide polymorphisms (SNPs) in the promoters of IL-3, IL-4, and IL-13 genes on the 5q31-33, IL-3 -16T>C, IL-4 -590T>C, and IL-13 -1055C>T, with severity of malaria in 361 adult malaria patients in Thailand. The IL-13 -1055T allele showed a significant association with protection from severe malaria (OR 0.51, 95% CI 0.32-0.80; P=0.0032 by the chi(2) test), while allele frequencies of IL-3 -16T>C and IL-4 -590T>C were not statistically different between mild and severe malaria patients. An IL-13 -1055C>T has been reported to alter the regulation of IL-13 production. Thus, IL-13 -1055T may show resistance to severe malaria through the alteration of IL-13 production.

Incompatibility of minor histocompatibility antigen (mHa) is a major cause of acute graft-versus-host disease (GVHD) following bone marrow transplantation in human leukocyte antigen (HLA)-matched donor-recipient pairs. To avoid acute GVHD, as many mHa genes as possible need to be identified. In this study, we introduce a comparison of two proportions as an association test for detecting mHa genes in HLA-matched pairs with and without GVHD. Assuming multiple mHa loci, each with two alleles, we evaluated the effects of (1). minor allele frequency of the mHa locus of interest (denoted by p), and (2). probability of GVHD developing in a donor-recipient pair being incompatible at an mHa locus (denoted by r) on the powers of association tests for unrelated pairs and for sib pairs. Our results showed that based on a candidate gene approach, an mHa gene with high p and r values can be detected by the association test with a small sample size. Application of the present method to the Japanese population revealed that the association test for unrelated pairs is more suitable for detecting an mHa gene with a high r value than that for sib pairs. The present method will be helpful to researchers who evaluate the power of association study in advance.

Linkage disequilibrium (LD) testing is often used in the search for disease genes. In this study, we developed a method for calculating the expected power of genome-wide LD testing by using microsatellite markers under the following assumptions: (1) microsatellite markers have unequally frequent alleles, (2) markers are equally spaced through the human genome, (3) the degree of LD between the disease variant and the marker decays gradually because of recombination and mutation, (4) the population frequency of the disease variant is low (e.g., 0.05), (5) a single-marker test is performed in a case-control study, and (6) the significance level is adjusted by the number of tests to avoid inflation of the type I error. Our calculations revealed a markedly higher power for microsatellite markers than for single nucleotide polymorphism (SNP) markers, even if more SNPs are analyzed, suggesting that the use of microsatellite markers is preferable to the use of SNPs for genome-wide screening under the above assumptions. This method will be helpful to researchers who design genome-wide LD testing with microsatellite markers.

Conventional phylogenetic trees for the human leukocyte antigen (HLA)-DRB1 alleles constructed by the neighbor-joining (Saitou and Nei 1987) and UPGMA (Sneath and Sokal 1973) methods using nucleotide sequences of the DRB1 alleles suggest that DRB1*0701 may have diverged from other DRB1 alleles before the separation of the human and chimpanzee species, because of a large number of nucleotide changes in DRB1*0701 compared with any of the other DRB1 alleles. Here we show new evidence that the haplotypes centering on DRB1*0701 and DRB1*04 alleles are the most homologous. This suggests that these haplotypes have derived from the common ancestral haplotype, and that they have likely retained complete linkage disequilibrium even after the divergence of the DRB1*0701 and DRB1*04 allelic lineages. Together with the corresponding haplotype carrying chimpanzee DRB1*0701, which has a high sequence homology to HLA-DRB1*0701, these haplotypes reveal that: (1) the DRB1*04 allelic lineage may have been generated from the DRB1*0701 lineage after the separation of the human and chimpanzee species; (2) the DRB1*04 allelic lineage possibly has a higher substitution rate of DRB1 compared with pseudogene and neutral region; (3) there could be a significant difference in the substitution rate of DRB1 between the DRB1*0701 and DRB1*04 allelic lineages. Based on the difference between the present and previous results, we would like to propose that phylogenetic studies using not only nucleotide sequences of the DRB1 alleles but also haplotypes centering on the alleles should be conducted for understanding detailed phylogenetic relationships of the DRB1 alleles.

FOXC2, a forkhead/winged helix transcription factor, represents a promising candidate gene for type 2 diabetes since transgenic mice that specifically overexpress this gene in adipocytes are lean and insulin sensitive. To determine whether there are single nucleotide polymorphisms (SNPs) in this gene that are associated with type 2 diabetes, sequences of the coding and ∼1 kb of 5′ flanking regions in 24 Japanese type 2 diabetic subjects were initially analyzed using PCR direct sequencing, and the regions containing the identified polymorphisms were then examined. In 200 control subjects, three frequent SNPs were found (g. −512C>T [32.3%] and −350G>T [13.0%] in the 5′ flanking region and +1548C>T [10.0%] in the 3′ flanking region). Linkage disequilibria were found between all three pairs of these SNPs. Of the eight possible haplotypes defined by these SNPs, only four were found. When the frequencies of these SNPs and the four common haplotypes between 195 type 2 diabetic and 200 control subjects were compared, no association was evident. The +898C>T (Pro300Ser), +907C>A (Leu303Met), 1167_1169delCCA (389delHis), and +1251C>A (Ala417Ala) identified in the coding region were rare, although +907C>A could be higher in type 2 diabetic subjects (1.5%) than in control subjects (0.3%). Thus, the SNPs identified in the FOXC2 gene are unlikely to have major effects on susceptibility to Japanese type 2 diabetes.

This paper illuminates Japanese politeness orientation by investigating the use of the formulaic expression, yoroshiku onegaishimasu (literal meaning: 'I make a request and I hope things go well') in naturalistic data. Yoroshiku onegaishimasu is frequently used in various contexts, serving various pragmatic functions. The paper discusses the link between its literal meaning and its functions, and reveals a Japanese culture-specific 'face' which is more sensitive to debt than the threat to the freedom of action. By saying yoroshiku onegaishimasu, the speaker clearly indicates that slhe is a debtor or, in other words, the speaker clearly acknowledges slhe benefits (or will benefit) from the hearer. Such an act is considered to be polite in Japanese, and thus yoroshiku onegaishimasu is used in wider contexts. It is argued that caring for the debt-credit equilibrium is a significant politeness phenomenon in Japanese. © Waller de Gruyter.

Perelik, Solang, and Mouk villages are located in Balopa islands of Papua New Guinea (PNG). It is known that languages spoken in Balopa belong to the same family of Austronesian languages, but the language of Mouk is different from others at a sub-family level. Most of Balopa islanders have subsisted mainly on horticulture and reef fishing, while Mouk villagers have depended on fishing and trading. In order to investigate the genetic similarities among Balopa islanders and their affinities to other Oceanian populations, HLA-DRB1 polymorphism was investigated in 98 individuals living in Perelik, Solang, and Mouk. The predominant HLA-DRB1 alleles in Balopa islands were HLA-DRB1*1502 and *1101. Interestingly, Mouk showed a similar distribution of DRB1 alleles to Solang despite their different language and subsistence. Genetic distance calculations and correspondence analysis based on DRB1 allele frequencies suggested that Balopa islanders genetically belong to Austronesians in Melanesia and are distant from other Austronesians in Micronesia or Polynesia.

There are three genetic methods often used for detecting genes contributing to susceptibility or resistance to multifactorial diseases: nonparametric linkage analysis, case-control association analysis, and transmission disequilibrium test. In this review, we present the theoretical basis that the case-control association study has the highest power of detecting disease genes if there is no population stratification between patients and controls. Taking advantage of the high power, we have carried out extensive case-control association analyses of candidate genes for the search of susceptibility genes to rheumatic diseases in the Japanese as well as in some other populations. Several new associations have been disclosed, including those of TNFR2, FCGR2B, and CD19 gene polymorphisms with systemic lupus erythematosus, in addition to some unexpected findings such as the common occurrence of NKG2-C null allele in the healthy population. Genome-wide association studies using single nucleotide polymorphisms (SNPs) or microsatellite polymorphisms have become realistic, and development of new high-throughput and cost-effective SNP typing technologies is urgently needed. At the same time, our observations may indicate that the 'classical' candidate gene approach will remain a strong alternative, even in the age of 'post genome-sequence'.

Herpes zoster is a common disease caused by reactivation of the varicella zoster virus (VZV). In a small number of herpes zoster patients, pain persists beyond 4 weeks or more after healing of vesicular eruptions; this condition is termed postherpetic neuralgia (PHN). Positive associations of human histocompatibility leukocyte antigens (HLA) class I antigens, A33 and B44, with PHN in the Japanese population have been reported. Our hypothesis is that susceptibility genes to PHN might exist in the HLA region and the study objective is to further examine possible associations of genes in HLA class I, II and III regions, HLA-A, -B, -DRB1, tumor necrosis factor alpha (TNFA) promoter, and a natural killer cell activating receptor, NKp30 polymorphisms with PHN. Although TNFA or NKp30 in the class III region had been considered as a candidate locus, we found no associations of TNFA promoter or NKp30 polymorphisms with PHN in this study. We demonstrated that HLA-A*3303, -B*4403 and -DRB1*1302 alleles were significantly associated with PHN (P = 0.0007 for A*3303, P = 0.001 for B*4403 and P = 0.001 for DRB1*1302). The frequency of the HLA-A*3303-B*4403-DRB1*1302 haplotype was also significantly higher in the PHN patients than in the healthy controls (P = 0.0039). Our results suggest that this haplotype might be related to the pathogenesis of PHN.

Human FcgammaRIIA and FcgammaRIIIB exhibit genetic polymorphisms, FcgammaRIIA-131H/R and FcgammaRIIIB-NA1/NA2, coding for different capacities for IgG binding and phagocytosis. Recently, FcgammaRIIA-131R was reported to be associated with protection against high-density Plasmodium falciparum infection in Kenya. Furthermore, FcgammaRIIIB-NA1/NA2 polymorphism was shown to influence FcgammaRIIA function in an allele-specific manner. In this study, we examined a possible association of FcgammaRIIA-131H/R and FcgammaRIIIB-NA1/NA2 polymorphisms with malaria severity in 107 cerebral malaria patients, 157 non-cerebral severe malaria patients, and 202 mild malaria controls living in northwest Thailand. This study reveals that, with the FcgammaRIIIB-NA2 allele, the FcgammaRIIA-131H/H genotype is associated with susceptibility to cerebral malaria (OR 1.85, 95% CI 1.14-3.01; P=0.012), although these polymorphisms are not individually involved in the disease severity. Our results suggest that FcgammaRIIA-131H/R and FcgammaRIIIB-NA1/NA2 polymorphisms have an interactive effect on host defense against malaria infection.

Resistin is a novel polypeptide specifically secreted from adipocytes, and its serum levels are increased in obese diabetic mice. Resistin antagonizes insulin and could account for insulin resistance. To determine whether there are single nucleotide polymorphisms (SNPs) in the resistin gene associated with type 2 diabetes, sequences for 24 Japanese type 2 diabetic patients were initially analyzed using PCR direct sequencing. Three SNPs were found in the introns, but none were present in the coding regions. The allele frequencies of genomic −167C>T, +157C>T, and +299G>A in 99 Japanese control subjects were determined to be 3.5, 6.6, and 39.4%, respectively. In each pair of these SNPs, linkage disequilibria were found between either −167C>T and +299G>A or +157C>T and +299G>A. A linkage disequilibrium was also detected among −167C>T, +157C>T, and +299G>A, and only four of the eight possible haplotypes defined by these SNPs were found. A comparison of the frequencies of these SNPs and haplotypes between 99 type 2 diabetes and 99 control subjects revealed no evidence for any association. These identified SNPs, which were in linkage disequilibrium, represent potentially useful tools for searching for their association with specific phenotypes of diabetes.

The people of the Solomon Islands represent an Austronesian (AN)-speaking population’s adaptation to a humid tropical environment and subsistence of tuberous crops. Genome-wide association studies (GWASs) of other populations (e.g. the Human Genome Diversity Project [HGDP]) have suggested the existence of genotypes adaptive to ecoregion, diet, and subsistence, and that those genotypes are also associated with metabolic and cardiovascular diseases. Recently, the incidence of non-communicable diseases has been increasing in the Solomon Islands. In the present study, we explored the association of genotypes adaptive to a tropical environment and tuberous crop diet with metabolic and cardiovascular conditions in rural and urban AN-speaking Melanesian and Micronesian populations of the Solomon Islands. A total of 561 participants were genotyped for single nucleotide polymorphisms (SNPs) potentially associated with a tropical environment (rs174570 and rs2237892) and a tuberous crop diet (rs162036, rs185819, and rs2722425). The results showed that the allele frequencies of the Solomon Islands populations adopted patterns similar to those in populations from other hot, tropical areas with a tuberous crop diet in previous studies. Furthermore, rs162036, rs185819, rs2237892, and rs2722425 were all strongly associated with one or more metabolic and cardiovascular conditions. The derived allele of rs2722425 (i.e. rs2722425-G) was significantly associated with an elevated LDL level (P = 0.000264) even after the significance level was adjusted for multiple testing (i.e., α = 0.0005). Our results suggest that the inhabitants of the Solomon Islands exhibit the effects of the tropical environment and tuberous crop diet on their allele frequencies, and that their susceptibility to metabolic and cardiovascular diseases is therefore considered to be associated with their environment and diet., 論文

Background Dengue shock syndrome (DSS), a severe life-threatening form of dengue infection, mostly occurs in children. A recent genome wide association study (GWAS) identified two SNPs, rs3132468 of major histocompatibility complex class I polypeptide-related sequence B (MICB) and rs3765524 of phospholipase C, epsilon 1 (PLCE1), associated with DSS in Vietnamese children. In this study, to examine whether an identical association is found in a different population, the association of these two SNPs with DSS was assessed in Thai children with dengue. Methods The rs3132468 and rs3765524 SNPs were genotyped in 917 Thai children with dengue: 76 patients with DSS and 841 patients with non-DSS. The allele frequencies were compared between DSS and non-DSS groups by one-sided Fisher’s exact test. The association of rs3132468 and rs3765524 with the mRNA expression levels of MICB and PLCE1 were assessed in EBV-transformed lymphoblastoid cell lines. Results The reported DSS-risk alleles were significantly associated with DSS in Thai patients with dengue (one-sided P = 0.0213 and odds ratio [OR] = 1.58 for rs3132468-C and one-sided P = 0.0252 and OR = 1.49 for rs3765524-C). The rs3132468-C allele showed a significant association with lower mRNA level of MICB (P = 0.0267), whereas the rs3765524-C allele did not. These results imply that the MICB molecule may play an important role in the prevention of DSS in dengue infection. Conclusions Together with previous association studies, we conclude that rs3132468-C at MICB and rs3765524-C at PLCE1 confer risk of DSS in Southeast Asians.

Background Cytoadhesion of Plasmodium falciparum-infected erythrocytes to endothelial cells in microvessels is a remarkable characteristic of severe malaria. The endothelial protein C receptor (EPCR), encoded by the endothelial protein C receptor gene (PROCR), has recently been identified as an endothelial receptor for specific P. falciparum erythrocyte membrane protein 1 (PfEMP1) subtypes containing domain cassettes (DCs) 8 and 13. The PROCR rs867186-G allele (serine-to-glycine substitution at position 219 of EPCR; 219Gly) has been shown to be associated with higher levels of plasma soluble EPCR (sEPCR). In this study, the association of PROCR rs867186 with severe malaria is examined in Thai population. Methods A total of 707 Thai patients with P. falciparum malaria (341 with severe malaria and 336 with mild malaria) were genotyped for rs867186. To assess the association of PROCR rs867186 with severe malaria, three models (dominant, recessive and allelic) were evaluated. The rates of non-synonymous and synonymous substitutions were estimated for the coding sequence of the PROCR gene. Results The rs867186-GG genotype was significantly associated with protection from severe malaria (P-value = 0.026; odds ratio = 0.33; 95% confidence interval = 0.12–0.90). Evolutionary analysis provided no evidence of strong positive selection acting on the PROCR gene. Conclusion The rs867186-GG genotype showed significant association with protection from severe malaria. The present results suggest that PfEMP1–EPCR interaction, which can mediate cytoadhesion and/or reduce cytoprotective and anti-inflammatory effects, is crucial to the pathogenesis of severe malaria.

Previous studies have revealed the association between SNPs located on human leukocyte antigen (HLA) class II genes, including HLA-DP and HLA-DQ, and chronic hepatitis B virus (HBV) infection, mainly in Asian populations. HLA-DP alleles or haplotypes associated with chronic HBV infection or disease progression have not been fully identified in Asian populations. We performed trans-ethnic association analyses of HLA-DPA1, HLA-DPB1 alleles and haplotypes with hepatitis B virus infection and disease progression among Asian populations comprising Japanese, Korean, Hong Kong, and Thai subjects. To assess the association between HLA-DP and chronic HBV infection and disease progression, we conducted high-resolution (4-digit) HLA-DPA1 and HLA-DPB1 genotyping in a total of 3,167 samples, including HBV patients, HBV-resolved individuals and healthy controls. Trans-ethnic association analyses among Asian populations identified a new risk allele HLA-DPB1*09 ratio 01 (P = 1.36 x 10(-6); OR= 1.97; 95% CI, 1.50-2.59) and a new protective allele DPB1*02 ratio 01 (P = 5.22 x 10(-6); OR = 0.68; 95% CI, 0.58-0.81) to chronic HBV infection, in addition to the previously reported alleles. Moreover, DPB1*02 ratio 01 was also associated with a decreased risk of disease progression in chronic HBV patients among Asian populations (P = 1.55 x 10(-7); OR = 0.50; 95% CI, 0.39-0.65). Trans-ethnic association analyses identified Asian-specific associations of HLA-DP alleles and haplotypes with HBV infection or disease progression. The present findings will serve as a base for future functional studies of HLA-DP molecules in order to understand the pathogenesis of HBV infection and the development of hepatocellular carcinoma., published_or_final_version

Cytotoxicity of natural killer (NK) cells is regulated by a balance of signals from two kinds of NK receptors, activating receptors and inhibitory receptors. Natural cytotoxicity receptors (NCR) family, which consists of NKp30, NKp44 and NKp46, is a major human activating NK receptor. NKp30 has been mapped to the HLA class III region near tumor necrosis factor (TNF) family loci. We have analyzed the NKp30 gene of healthy Japanese and found two synonymous substitutions in the coding region, c.111G>A and c.156C>T, and also identified two single-nucleotide polymorphisms (SNPs) in the promotor region, −201G>A and −163G>C. Furthermore, it was confirmed that these polymorphisms of the NKp30 gene show strong linkage disequilibria with each other and with HLA-DRB1 or TNFA polymorphisms. Since susceptibilities to certain diseases were mapped near this region, the NKp30 polymorphisms could be useful genetic markers.

We have been studying polymorphisms of HLA class I and II genes in East Asians including Buryat in Siberia, Mongolian, Han Chinese, Man Chinese, Korean Chinese, South Korean, and Taiwan indigenous populations in collaboration with many Asian scientists. Regional populations in Japan, Hondo-Japanese, Ryukyuan, and Ainu, were also studied. HLA-A, -B, and -DRB1 gene frequencies were subjected to the correspondence analysis and calculation of DA distances. The correspondence analysis demonstrated several major clusters of human populations in the world. "Mongoloid" populations were highly diversified, in which several clusters such as Northeast Asians, Southeast Asians, Oceanians, and Native Americans were observed. Interestingly, an indigenous population in North Japan, Ainu, was placed relatively close to Native Americans in the correspondence analysis. Distribution of particular HLA-A, -B, -DRB1 alleles and haplotypes was also analyzed in relation to migration and dispersal routes of ancestral populations. A number of alleles and haplotypes showed characteristic patterns of regional distribution. For example, B39-HR5-DQ7 (B*3901-DRB1*1406-DQB1*0301) was shared by Ainu and Native Americans. A24-Cw8-B48 was commonly observed in Taiwan indigenous populations, Maori in New Zealand, Orochon in Northeast China, Inuit, and Tlingit. These findings further support the genetic link between East Asians and Native Americans. We have proposed that various ancestral populations in East Asia, marked by different HLA haplotypes, had migrated and dispersed through multiple routes. Moreover, relatively small genetic distances and the sharing of several HLA haplotypes between Ainu and Native Americans suggest that these populations are descendants of some Upper Paleolithic populations of East Asia.

It has recently been shown that the A/A genotype at g.−23 of the insulin gene correlates with impaired insulin secretion in response to body weight gain in subjects of European descent. To examine whether there are single nucleotide polymorphisms (SNPs) in the insulin gene associated with type 2 diabetes, all exons with their flanking sequences for 113 Japanese type 2 diabetic patients and 99 nondiabetic control subjects were analyzed using PCR direct sequencing. We have only found g.−23T → A, 806G → C, 1128T → C, and 1141A → C, which have previously been reported in alpha (A-C-C-C) and beta (T-G-T-A) alleles. The allele frequency of −23T → A in control Japanese subjects was 97.4%, whereas that in Europeans is about 30%. The A/A genotype was found in 94 of 99 Japanese subjects (94.9%) and the allele frequencies of 806G → C, 1128T → C, and 1141A → C were all 96.5%. The estimated haplotype frequencies were (A-C-C-C) (96.0%), (T-G-T-A) (2.0%), (A-G-T-A) (1.5%), and (T-C-C-C) (0.5%). No association of these SNPs or haplotypes with type 2 diabetes was evident. Thus, the A/A genotype at the g.−23 of insulin gene was generally high in Japanese subjects, which could account for the fact that they typically secrete lower levels of insulin.

For 197 adults and adolescents in four villages of three small islands in the Admiralty Islands, Papua New Guinea, antimalarial antibody titers were examined using the indirect fluorescent antibody test (IFAT) and malaria parasites were detected by the microtiter plate hybridisation (MPH) method using polymerase chain reaction (PCR) technique. The parasite rate (either Plasmodium falciparum or P. vivax, or both) averaged 39.2 %, varying from 31.1 % to 44.8 % among the four villages due to natural and artificial microenvironmental conditions related to breeding sites of mosquitoes ( Anopheles farauti). The lack of flat zones owing to geomorphological formation contributed to the lowest parasite rate in the extremely small island. However, human-modified environments such as a wet-land (naturally formed but artificially reformed) and an open well played significant roles in other inter-village differences. The present findings imply significant roles of microenvironment in diversified malaria prevalence and suggest some ways of mitigation of malarial hazards. Asia Pac J Public Health 2001; 13(2): 85-90

In case-control studies of complex disease genes, allele frequencies or allele positivities at candidate loci or markers are compared between cases and controls. Although 2 x 2 contingency tables based on allele frequency and allele positivity are generally used to perform simple statistical tests (e.g. a comparison of two proportions and a chi2 test), little is known about the difference in power between the two tables. In this study, we investigated the number of subjects required to obtain a power of 1-beta with a significance level of alpha for the allele frequency and allele positivity tables. A large difference in the required number of subjects was found between the two tables. Allele positivity tables were suitable for the detection of susceptibility alleles showing a dominant mode of inheritance (MOI). On the other hand, allele frequency tables were suitable for the identification of susceptibility alleles showing a recessive MOI or a multiplicative MOI. In the case of an additive MOI, a suitable table was determined by combining the frequency of the susceptibility allele and the penetrance. These results imply that there are cases in which true association is detected based on one contingency table and is not detected based on another. A simulation analysis revealed that the type I error rate was not much inflated under the null hypothesis of no association, even when a statistical test was performed twice using both allele frequency and allele positivity tables. In contrast, under the alternative hypothesis, the loss of power was marked when a test was performed once using an unsuitable table. In conclusion, statistical tests should be performed using both tables, without adjustment of multiplicity, in case-control studies of complex disease genes when the study objective is exploratory.

The Minnan and Hakka people groups, the so-called "Taiwanese", are the descendants of early settlers from the southeast coast of China during the last few centuries. Genetically they showed affinities to southern Asian populations, as determined by phylogenetic trees and correspondence analysis calculated from HLA allele frequencies. This corresponds historically with the fact that they are the descendants of the southeast coastal indigenous population (Yueh) of China and should therefore not be considered as descendants of "pure" northern Han Chinese. A33-B58-DRB1*03 (A33-Cw10-B58-DRB1*03-DQB1*02), the most common HLA haplotype among "Taiwanese", with a haplotype frequency of 6.3%, has also been found to be the most common haplotype among Thai-Chinese and Singapore Chinese, two other populations also originating from the southeast coast of China. These observations suggests that this haplotype is the most well-conserved ancient haplotype of the Yueh.

A New World monkey, the common marmoset (Callithrix jacchus), will be used as a preclinical animal model to study the feasibility of cell and gene therapy targeting immunological and hematological disorders. For elucidating the immunogenetic background of common marmoset to further studies, in the present study, polymorphisms of MHC-DRB genes in this species were examined. Twenty-one Caja-DRB exon 2 alleles, including seven new ones, were detected by means of subcloning and the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) methods followed by nucleotide sequencing. Based on the alignment of these allele sequences, we designed two pairs of specific primers and established a PCR-SSCP method for DNA-based histocompatibility typing of the common marmoset. According to the family segregation data and phylogenetic analyses, we presumed that Caja-DRB alleles could be classified into five different loci. Southern blotting analysis also supported the existence of multiple DRB loci. The patterns of nucleotide substitutions suggests that positive selection operates in the antigen-recognition sites of Caja-DRB genes.

The sojourn times until fixation of an overdominant allele were investigated based on the diffusion equation. Furthermore, the rate of accumulation of mutations, or the substitution rate, was predicted from the mean extinction time of a common overdominant allele. The substitution rate calculated theoretically agreed well with that determined by computer simulation. Overdominant selection enhances the polymorphism at linked loci, while its effect on the sojourn times and the substitution rate at linked loci has not been studied yet. To solve these problems, a model that assumed two linked loci, each with infinite alleles, was examined by computer simulation. A decrease in the recombination rate between two loci markedly changed the distribution of sojourn times of a neutral allele. Although overdominant selection obviously increased the sojourn times and the polymorphism at a linked locus, the rate of nucleotide substitution at the neutral locus was not influenced significantly even if complete linkage was assumed. These results suggest that, in regions containing overdominant genes, linked neutral loci will exhibit elevated levels of polymorphism, but their rate of molecular evolution remains that predicted by neutral theory.

Polymorphisms of HLA-A, and -B antigens were investigated in the Kyrgyz population living in the northeastern part of Central Asia. Serological typing for HLA-A and -B loci was performed in 157 healthy unrelated blood donors. The frequent HLA-A antigens were A2 (29.2%), A24 (20.6%), and A1 (10.4%). For HLA-B loci, B51 (10.6%), B17 (9.1%), B13 (8.7%), and B35 (8.5%) were predominant. Multidimensional scaling and phylogenetic analysis were performed based on the gene frequencies of HLA-A and -B. In the multidimensional scaling for 24 worldwide populations, Kyrgyz situated itself close to other Central Asian populations. In the phylogenetic tree, Kyrgyz were included in the cluster of Central Asian, while they located close to the European cluster. Four HLA-A-B haplotypes, A2-B blank (5.7%), A2-B13 (4.7%), A24-B51 (3.9%), and A2-B17 (3.7%) were observed at frequencies of more than 3%. These haplotypes, except for A2-B blank have been observed in European and/or Asian populations. The present results well agree with the hypothesis, which has been proposed in morphological studies, that Kyrgyz have been derived from not only Mongoloid but also Caucasoid ancestors.

Tumor necrosis factor alpha plays a substantial role in a number of conditions such as inflammation, autoimmunity, insulin resistance and sleep. Three new single nucleotide polymorphisms, -1,031 T/C, -863 C/A and -857 T/C, were recently identified in the upstream 5'-flanking region of TNFA in the Japanese population. In the present study, we developed polymerase chain reaction (PCR)-preferential homoduplex formation assay for the single-step allele typing of TNFA, and determined the genotypes of 271 healthy unrelated Japanese individuals. Four haplotypes, -1,031/-863/-857 TCC, TCT, CAC and CCC, were found to constitute the majority, if not all, of the TNFA alleles of healthy Japanese population. These alleles were designated as TNFA-U01, -U02 -U03 and -U04, respectively, in the order of frequency. Based on HLA-A, -B and -DRB1 genotypes together with TNFA genotypes, multi-locus haplotypes were analyzed. Significant positive associations were observed between TNFA-U01 and A*3303, B*5201, B*4403, B*4601, B*0702, DRB1*1502, DRB1*0101, DRB1*1302, between TNFA-U02 and B*5401, B*3501, DRB1*0405, DRB1*0407, between TNFA-U03 and B*4006, B*4002, DRB1*0803, DRB1*0802, DRB1*0403, DRB1*0901, and between TNFA-U04 and B*4801. Four-locus haplotype estimation revealed that A*3303-B*4403-TNFA-U01-DRB1*1302, A*2402-B*5201-TNFA-U01-DRB1*1502 and A*2402-B*5401-TNFA-U02-DRB1*0405 constitute major extended haplotypes in Japanese. Interestingly, TNFA alleles previously shown to have a higher promoter activity (U02, U03) were found to form haplotypes with certain DRB1 alleles associated with T helper 1 (Th1)-dominant diseases such as rheumatoid arthritis, insulin dependent diabetes mellitus and Crohn's disease in Japanese. In contrast, TNFA allele with a low promoter activity (U01) is in linkage disequilibrium with the DRB1 alleles associated with T helper 2 (Th2)-dominant diseases such as atopic dermatitis and ulcerative colitis. These observations raise the possibility that TNFA upstream promoter region polymorphisms contribute to some of the HLA-disease associations.

Human Fc gamma receptor (Fc gamma R) genes form a clustered gene family on chromosome 1q21-24. Although the association of Fc gamma R polymorphisms with systemic lupus erythematosus (SLE) has been extensively studied, the results are often contradictory. In this study, Fc gamma RIIA-131H/R, Fc gamma RIIIA-176F/V and Fc gamma RIIIB-NA1/2 genotypes were determined in the Japanese patients with SLE (n = 81) or rheumatoid arthritis (RA, n = 115) as well as in healthy individuals (n = 217), and possible association with the disease was tested using case-control analysis. Unlike in other populations, significant difference was not observed in the frequencies of Fc gamma RIIA and Fc gamma RIIIA genotypes between patients with SLE and healthy individuals. However, significant difference was detected in the frequencies of Fc gamma RIIIB genotypes between SLE and healthy individuals (P = 0.008). The odds ratio [OR] of the Fc gamma RIIIB-NA2/NA2 homozygotes for the development of SLE was 2.52 (95% confidence interval [CI]: 1.33-4.79). Among the patients with SLE, individuals with NA2/2 were significantly more likely to have lupus nephritis (P = 0.007). No association was observed between any of the Fc gamma R polymorphisms and RA. Significant linkage disequilibrium was detected between Fc gamma RIIIA and IIIB, but neither between IIA and IIIA, nor between IIA and IIIB. These observations may underscore the relevance of defective immune complex handling in the pathogenesis of SLE, or may suggest the presence of primarily associated gene(s) in linkage disequilibrium with Fc gamma R genes.

Narcolepsy is a sleep disorder in which multiple factors, including environmental and genetic factors, are involved. A genetic factor strongly associated with the disorder has been found in the human leukocyte antigen (HLA) class II region: the haplotype, DRB1*1501–DQB1*0602, predisposes to narcolepsy. No susceptibility genes other than the HLA-haplotype have been found. In this paper, we performed an association study of the tumor necrosis factor-alpha (TNF-α) gene located in the HLA class III region with human narcolepsy, in which we examined the known single-nucleotide polymorphisms (SNPs) in the promoter region in 49 narcoleptic patients, who were all positive for DRB1*1501, and 111 healthy control individuals. The results indicated that the frequency of the genotype at position −857 (−857SNP) was significantly different between the patients and controls, and the allele frequencies of –857SNP revealed that the frequency of –857T was significantly increased in the patients as compared with that in the controls (P=0.0068). In addition, haplotypes presumed from HLA-DRB1, –857SNP and HLA-B loci suggested that –857T was mainly associated with DRB1 alleles other than DRB1*1501: the significant increase in frequency of –857T in the patients was not caused by allelic association with DRB1*1501. Therefore, it is conceivable that the TNF-α with –857T was associated with narcolepsy independently of the strong association of DRB1*1501 with the disorder. Altogether, the data presented here lead us to propose that TNF-α could be a new susceptibility gene in human narcolepsy.

Objective Sugammadex rapidly reverses neuromuscular blockade (NMB) induced by rocuronium. NMB induced by rocuronium is prolonged in patients with liver dysfunction, because the drug is mainly excreted into the bile. However, the efficacy and safety of sugammadex in terms of reversing rocuronium-induced NMB in patients with liver dysfunction undergoing hepatic surgery have not been evaluated. This observational study investigated the efficacy and safety of sugammadex after continuous infusion of rocuronium in patients with liver dysfunction undergoing hepatic surgery. Methods Remifentanil/propofol anesthesia was administered to 31 patients: 15 patients in the control group, and 16 patients from a group with liver dysfunction. Rocuronium (0.6 mg/kg) was administered, followed by continuous infusion. The enrolled patients were then subdivided into two groups according to the dose of sugammadex. In the first group a single dose of sugammadex (2.0 mg/kg) was given at the reappearance of the second twitch (T2). In the second group a single dose of sugammadex (4.0 mg/kg) was given at the first twitch response if T2 did not reappear in 15 minutes after stopping rocuronium. The primary outcome was time from administration of sugammadex to recovery of a train-of-four ratio to 0.9. Results The dose of rocuronium required in the liver dysfunction group was lower than that in the control group (6.2 vs. 8.2 μg/kg/min, p = 0.002). The mean time from the administration of sugammadex to recovery of the train-of-four ratio to 0.9 was not significantly different between the liver dysfunction group and the control group (2.2 minutes vs. 2.0 minutes in the 2 mg/kg administration group, p = 0.44 and 1.9 minutes vs. 1.7 minutes in the 4 mg/kg administration group, p = 0.70, respectively). No evidence of recurarization was observed in any of the patients. Most of the adverse events were found to be mild and such events were not related to the use of sugammadex. None of the patients was eliminated from the study because of an adverse event. One patient died due to cholestatic liver cirrhosis because of repeated hepatic surgery. Conclusion Sugammadex can rapidly reverse NMB after continuous infusion of rocuronium in patients with liver dysfunction undergoing hepatic surgery. Sugammadex was found to be safe and well tolerated. However, further studies of sugammadex under similar conditions should be conducted involving a large number of patients with liver dysfunction undergoing hepatic surgery.

Background:Our previous study demonstrated that the A-allele of the single nucleotide polymorphism (SNP) rs34623097 located in the upstream region of the β2 adrenergic receptor gene (ADRB2) is significantly associated with risk for obesity in Oceanic populations.\nMethods:To investigate whether the ADRB2 polymorphisms explain part of the individual differences in lipid mobilization, energy expenditure and glycogen breakdown, the associations of 10 ADRB2 SNPs with total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglyceride levels were examined in 128 adults in Tonga.\nResults:A multiple linear regression analysis adjusted for age, sex, and body mass index revealed that rs34623097 was significantly associated with triglyceride levels (P-value = 0.037). A copy of the rs34623097-A allele increased serum triglyceride levels by 70.1 mg/dL (0.791 mmol/L). None of the ADRB2 SNPs showed a significant association with total-cholesterol, high-density lipoprotein cholesterol, or low-density lipoprotein cholesterol.\nConclusions:In a Tongan population, a SNP located in the upstream region of ADRB2 is associated with triglyceride levels independent of body mass index., 論文

In this chapter, I will investigate naturally occurring telephone conversations based on the assumptions that any natural conversational data sets are artefacts reflecting social norms (certain expected ways of doing things in a given community), intentions, the relationships of the participants at a given time in a specific context, and as they engage in conversation, meaning is negotiated and co-constructed. Face, therefore, becomes more salient in motivating conversational participants to opt for certain social and linguistic behaviours. In other words, ‘face consideration’ can be a prominent determiner of how people interact in real-life speech events. The DCT and the role-play data successfully fulfil their roles in providing us with information regarding how participants perceive the given thanking episodes and how they think they may speak and behave, and as a result some regularities, or ‘norms’, are obtained. Here, the notion of ‘norms’ is considered as empirically grounded common ways of doing things as found in the previous two studies, and norms will be used in this chapter to understand meaning in interaction. The informants did not have to pay much attention to nurturing interpersonal relationships in the previous two studies, as they knew no matter what they say to each other in a make-believe situation, no genuine harm would be done.1

In what follows, the findings of the studies are drawn on again to shed new light on some of the contemporary issues including teaching Japanese, and the notions of face and politeness. Finally, some specific suggestions will be made concerning the integration of the norm of ‘reciprocity’ and the rules of ‘self-respect’ and ‘considerateness’ into the studies of social interaction.

In this chapter, two data-based studies will be used to explore the Japanese speech act of ‘thanking’. Studies 1 and 2 will investigate Japanese cultural patterns of speech act realisations from different perspectives using different data elicitation methods and research designs. The analysis of both studies will take the respective characteristics and the limitations of the data elicitation methods employed into consideration. Study 1 encompasses the field of cross-cultural pragmatics as well as interlanguage pragmatic transfer, including native speakers of Japanese and English, and also English-speaking learners of Japanese.1 However, as discussed in the previous chapter, the learners’ data will not be compared with any native speaker groups.

This chapter will explore the data elicitation methods used in the study of cross-cultural and interlanguage pragmatics, by examining different methods including discourse completion tasks (DCTs) and role-plays. Understanding the characteristics of chosen data elicitation methods is important because they can shape the quality of the data. Data elicitation methods constrain L2 (second language) learners’ performance significantly more than target native speakers due to the learners’ unstable linguistic competence. Therefore, it is important for researchers to have an understanding about L2 learners’ possible deployment of ‘communication strategies’ before interpreting their performance in relation to their L1 (first language) pragmatic transfer. Also researchers need to be informed about L2 learners’ L2 and their sociocultural norms in order to understand the learners’ L2 performance accurately.