HLA-DQA1和HLA-DQB1等位基因与皖籍汉族人群白癜风的相关性

目的 探讨HLA-DQA1、-DQB1等位基因与皖籍汉族人群白癜风的相关性。方法 采用聚合酶链反应-序列特异性引物(PCR-SSP)方法,检测白癜风患者的HLA-DQA1、-DQB1等位基因。结果 与正常人对照组比较,①白癜风患者HLA-DQA1*0302、-DQB1*0303、-DQB1*0503等位基因频率显著升高,HLA-DQA1*0501等位基因频率显著降低;②HLA-DQA1*0302、-DQA1*0601、-DQB1*0303、-DQB1*0503等位基因频率在儿童型白癜风患者中显著升高,HLA-DQA1*0501等位基因频率显著下降;而成人型白癜风患者HLA-DQB10303等位基因频率显著升高;③HLA-DQA1*0302、-DQB1*0303、-DQB1*0503等位基因频率在泛发型白癜风患者中显著升高,HLA-DQA1*0501等位基因频率显著下降;而局限型白癜风患者HLA-DQB1*0303等位基因显著升高。结论 HLA-DQA1*0302、-DQA1*0601、-DQB1*0303、-DQB1*0503、-DQA1*0501等位基因可能与白癜风相关,不同类型白癜风在其遗传背景上可能存在异质性。     

华东地区汉族某些HLA-Ⅱ类等位基因与白癜风的相关性研究

目的 探讨华东地区汉族HLA-Ⅱ类基因与白癜风的相关性。方法采用聚合酶链反应-序列特异性寡核苷酸探针(PCR-SSOP)方法检测华东地区汉族白癜风患者HIA-DRB1、DQA1和DQB1位点的等位基因。结果与正常人对照组比较，患者DQA1^*03基因频率显著增高(Pc=0.008)．而DQA1^*05基因频率显著降低(Pc=0．016)。结论在华东地区汉族人群中，HLA-DQA1^*03、DQA1^*05可能与白癜风相关。     

广西壮族系统性红斑狼疮与HLA-DRB1等位基因相关性研究

目的 探讨广西壮族系统性红斑狼疮(SLE)与HLA-DRB1基因的相关性。方法 用聚合酶链反应-序列特异性引物(PCR-SSP)方法,对52例SLE壮族患者和70例壮族健康人的HLA-DRB1基因进行研究。结果 SLE患者HLA-DRB1*1401及DRB1*16两个等位基因的频率低于正常对照组(RR=0.28,χ²=5.00,P=0.02及RR=0.39,χ²=3.95,P=0.05),患者组和对照组均未检出HLA-DRB1*08、DRB1*11和DRB1*13等位基因。结论 提示HLA-DRB1*1401及DRB1*16等位基因可能是广西壮族人SLE的保护基因,未发现易感基因。     

HLA-DQA1*0302、DQB1*0303与新疆维吾尔族白癜风的相关性研究

目的 探讨HLA-DQA1、DQB1等位基因与新疆维吾尔族白癜风相关性。方法 聚合酶链反应-序列特异性引物（PCR-SSP）检测300例维吾尔族白癜风患者HLA-DQA1*0302、DQB1*0303等位基因。结果 与300例维吾尔族正常人对照组相比,①白癜风患者DQA1*0302（20.5%比13.83%）、DQB1*0303（30.17%比13.33%）等位基因频率显著增高（P ＜ 0.01）;②HLA-DQA1*0302、DQB1*0303等位基因频率在成人型（发病年龄 ＞ 12岁）及儿童型（发病年龄≤12岁）的白癜风患者中均增高（P ＜ 0.01）;③HLA-DQB1*0303等位基因频率在有、无家族史的白癜风患者中均增高（P ＜ 0.01）,HLA -DQA1*0302等位基因频率在无家族史病例中显著增高（P ＜ 0.01）;④白癜风组儿童型和成人型两组间比较及有、无家族史两组间比较,DQA1*0302、DQB1*0303等位基因频率差异无统计学意义（P > 0.05）。 结论 HLA-DQA1*0302、DQB1*0303等位基因可能与新疆维吾尔族白癜风相关,儿童型和成人型及有、无家族史的白癜风在其遗传背景上可能存在异质性。     

HLA-DQA1及DQB1等位基因与寻常型银屑病遗传易感性研究

目的 探讨HLA-DQA1和DQB1等位基因与汉族人寻常型银屑病遗传易感性。方法 利用聚合酶链反应-序列特异引物(PCR-SSP)法,对189例银屑病患者和273例健康人的HLA-DQA1和DQB1等位基因进行检测。结果 ①HLA-DQA1*0104和DQA1*0201与汉族人银屑病呈正相关性(Pc<0.05);DQA1*0501与汉族人银屑病呈负相关(Pc<0.001).②HLA-DQA1*0104、DQA1*0201和DQA1*0501等位基因与Ⅰ型银屑病发病有关。③HLA-DQA1*0104和DQA1*0201等位基因在有家族史和无家族史患者中的频率显着性增高。HLA-DQA1*0501仅在无家族史银屑病患者中显着性下降。结论 ①HLA-DQA1*0104和DQA1*0201可能是银屑病的易感基因或与易感基因相连锁;DQA1*0501等位基因可能具有阻止汉族人发生银屑病的作用。②有家族史和无家族史银屑病患者在其遗传背景上可能存在差异。     

色素障碍性皮肤病

20053290HLA-DQA1和HLA-DQB1等位基因与皖籍汉族人群白癜风的相关性/汪继之(安徽省皮防所),杨森,王红艳…∥中华皮肤科杂志.-2005,38(6).-357~359采用聚合酶链反应-序列特异性引物(PCR-SSP)方法检测187例皖籍汉族白癜风患者及273例正常对照的HLA-DQA1,-DQB1等位基因。结果:HLA-DQA1*0302,-DQB1*0303,-DQBP*0503等位基因频率在白癜风患者中显著升高;在儿童型患者中尚有HLA-DQA1*0601等位基因频率显著升高。白癜风组HLA-DQA1*0501等位基因频率显著降低。提示:HLA-DQA1*0302,-DQA1*0601,-DQB1*0303,-DQB1*0503,-DQA1*0501等位基因可能与白癜风相关,不同类型白癜风在其遗传背景上可能存在异质性。表1参6(穆欣)20053291白癜风患者血清可溶性细胞间黏附分子-1的检测/周渭珩(杭州市三院),洪为松,许爱娥∥中国中西医结合皮肤性病学杂志.-2005,4(1).-20~21采用酶联免疫吸附试验法检测40例白癜风患者血清中SICAM-1水平。结果:两组比较,白癜风患者...     

大疱及疱疹性皮肤病

20062700中国北方汉族寻常型天疱疮与HLA-Ⅱ类基因单倍型的相关性研究/耿龙(中国医大附属第二医院皮肤科),翟宁,韩秀萍…∥中国免疫学杂志.-2006,22(5).-453~455应用序列特异性引物-聚合酶链反应(PCR-SSP)技术对27例中国东北汉族PV患者的HLA-DRB1、DQB1等位基因测定,进行单倍型分析,并与99例健康对照者进行比较。结果显示与对照组比较,寻常型天疱疮患者组中单倍型DRB1*140×-DQB1*0503、DRB1*140×-DQB1*0201、DRB1*120×-DQB1*0503和DRB1*140×-DRB1*0302的频率明显增高,经统计学检验差异有显著意义(P<0.05)。提示特异单…     

华东地区汉族HLA-Ⅱ类基因与白癜风临床特征的相关性

目的：探讨华东地区汉族HLA-Ⅱ类基因与白癜风临床特征的相关性。方法：采用聚合酶链反应-序列特异性寡核苷酸探针(PCR-SSOP)方法检测华东地区汉族白癜风患者HLA-DRBl、DQAl和DQBl位点的等位基因，使用SPSS 10．0统计软件分析。结果：HLA-DQAl ^*0103与伴发内分泌疾病的患者有显著正相关，DRB l^*09与C4降低的患者明显负相关。按临床类型分析，发现局限型与DRBI*09和DQAl*03正相关，非节段型与DQAl*03正相关。结论：在华东地区汉族人群中，白癜风的临床特征与HIA-Ⅱ类基因有一定的相关性。     

寻常型白癜风临床特征及遗传传递方式分析

目的 分析中国汉族寻常型白癜风的临床特征及家族遗传特征,探索其可能的遗传传递方式。方法 以调查表的形式收集患者的临床资料及家系资料,用Epi Info 5.0及SPSS 10.0软件包进行统计学分析,用SAGE3.1进行遗传传递方式的复合分离分析。结果 寻常型白癜风的发病年龄为(19.02±12.58)岁,无性别差异(P=0.54);男女先证者疾病轻重程度(P=0.66)、发病季节分布(P=0.302)差异亦无统计学意义;女性患者的伴发疾病率显著高于男性(P=0.03),尤以甲亢为著(P=0.02)。患者亲属中白癜风患病率较一般人群显著增高。寻常型白癜风符合多基因累加遗传传递方式(P>0.05)。结论 寻常型白癜风的发生无性别差异,但存在明显的家族聚集性,该病的发生可能是由多基因累加遗传效应及环境因素共同作用的结果。     

广西壮族、汉族系统性硬化病与HLA-DQA1、DQB1等位基因相关性研究

目的 探讨广西壮族、汉族系统性硬化病(SSC)与HLA-DQA1、-DQB1等位基因的相关性.方法 用PCR-序列特异性引物(PCR-SSP)方法,对壮、汉族Sse患者各50例和壮、汉族健康人各100例的HLA-DQA1、-DQB1基因进行研究.结果 与正常人对照组相比,壮族SSc患者组中HLA-DQA1*0401、-DQB1*0501、-DQB1*0601基因频率显著升高(分别为RR:4.06,χ2=15.41,Pc<0.01;RR=4.47,χ2=10.65,Pc<0.01和RR=3.47,χ2=10.06,Pc<0.01),汉族SSc患者组中HLA-DQA1*0401、-DQA1*0601、-DQB1*0601基因频率显著升高(分别为RR=9.33,χ2=8.37,Pc<0.05;RR=8.071,χ2=20.13,Pc<0.01和RR=3.76,χ2=10.76,Pc<0.01).壮、汉族SSc患者组中HLA-DQA1*0201基因频率均显著降低(χ2=13.58,Pc<0.01和χ2=12.21,Pc<0.01).结论 HLA-DQA1*0401、-DQB1*0601可能是广西壮族、汉族SSc患者的易感基因,HLA-DQB1*0501可能是广西壮族SSc患者的易感基因,HLA-DQA1*0601可能是广西汉族SSc患者的易感基因.

Abstract：

Objective To explore the potential associations of HLA-DQA1 and DQB1 alleles with systemic scleroderma (SSc) in Zhuang and Han nationalities in Guangxi Zhuang Autonomous Region. Methods Genomic DNA was extracted from the peripheral blood of SSc patients of Zhuang (n=50) and Han (n=50) nationality,normal controls of Zhuang (n=100) and Han (n=100) nationality in Guangxi Zhuang Autonomous Region.PCR with sequence-specific primers (PCR-SSP) was used to detect HLA-DQA1 and -DQB1 alleles in these subjects. Results There was a significant increase in the frequency of HLA-DQA1*0401, -DQBl*0501 and -DQB1*0601 alleles in the patients of Zhuang nationalty(RR=4.056,χ2=15.407,PC=0.001;RR=4.472,χ2=10.653,Pc=0.004;RR=3.473,χ2=10.06,Pc=0.008)compared with normal controls of Zhuang nationality,and in the frequency of HLA-DQA1*0401,DQA1*0601 and DQB1*0601 alhles in patients of Han nationality (RR=9.333,χ2=8.371,Pc=0.036;RR=8.071,χ2=20.130,Pc=0.000;RR=3.764,χ2=10.755,Pc=0.004)compared with normal control of Han nationality.However,the frequency of HLA-DQA1*0201 allele was statistically lower in the patients of Zhuang and Han nationality than in the controls of corresponding nafionality (χ2=13.583,Pc=0.002;χ2=12.209,Pc=0.004).Conclusions HLA-DQA1*0401 and-DQB1*0601may be susceptible genes for SSc in Zhuang and Han nationalities,HLA-DQB1*0501 for Sse in Zhuang nationality,and HLA-DQAl*060l for SSc in Han nationality in Guangxi Zhuang Autonomous Region.     

MHC haplotypic association in Chinese Han patients with vitiligo

BACKGROUND: Serological typing of the human leucocyte antigen (HLA) has shown discrepancies in HLA associations with vitiligo in different ethnic populations. OBJECTIVE: To evaluate the distributions of HLA at class I and II loci that may contribute to the genetic susceptibility of vitiligo patients in Chinese Hans population. METHODS: We analysed the allelic frequencies of HLA class I and II by using the polymerase chain reaction sequence-specific primer (PCR-SSP) method in 187 patients with vitiligo and 273 controls in Chinese Hans. The linkage disequilibrium was calculated from a 2 x 2 table. RESULTS: Two-locus haplotypes including HLA-A25-B13, HLA-A25-B27, HLA-A25-Cw*0602, HLA-A25-DQA1*0302, HLA-A25-DQA1*0601, HLA-A25-DQB1*0303, HLA-B13-Cw*0602, HLA-B13-DQA1*0302, HLA-B13-DQA1*0601, HLA-B27-Cw*0602, HLA-B27-DQA1*0302, HLA-B27-DQA1*0601, HLA-B27-DQB1*0303, HLA-B27-DQB1*0503, HLA-Cw*0602-DQA1*0302, HLA-Cw*0602-DQA1*0601, HLA-Cw*0602-DQB1*0303, HLA-Cw*0602-DQB1*0503 and HLA-DQA1*0302-DQB1*0503 were associated with all types of vitiligo in Chinese Hans. The extended haplotypes HLA-A25-B13-Cw*0602, HLA-A25-B27-Cw*0602, HLA-DQA1*0302-DQB1*0303-Cw*0602 and HLA-B13-DQB1*0303-Cw*0602 were found to be associated with all types of vitiligo in Chinese Hans, whereas the frequency of HLA-A25-Cw*0602-DQA1*0302 was significantly increased in generalized vitiligo but not in localized vitiligo. The frequencies of HLA-A25-DQA1*0302-DQB1*0503 and HLA-A30-DQA1*0302-DQB1*0303 were higher in childhood vitiligo than in adult vitiligo, and the frequency of HLA-A25-B13-DQB1*0303-Cw*0602 was shown to be associated with adult vitiligo but not childhood vitiligo. CONCLUSION: This study demonstrates not only the differential association between HLA markers and types of vitiligo according to distribution or age at onset but also newly found high-risk haplotypes in Chinese vitiligo patients.     

A new extended haplotype Cw*0602-B57-DRB1*0701-DQA1*0201-DQB1*0201 associated with psoriasis in the Croatian population

In this study, we have analysed the distribution of HLA class II alleles and the extended haplotype HLA-Cw-B-DRB1-DQA1-DQB1 in Croatian patients with type I and type II psoriasis by hybridization with specific oligonucleotide probes. Type I psoriasis showed a significant association with the DRB1*0701 [P < 0.00001; relative risk (RR) = 5.83], DQA1*0201 (P < 0.00001; RR = 6.12), DQB1*0201 (P = 0.0006; RR = 3.29) and DQB1*0303 alleles (P = 0.0008; RR = 7.51). A negative correlation with type I disease was observed for the DQA1*0102 allele (P = 0.002; RR = 0.26). Type II psoriasis did not show any association with any class II alleles. The extended haplotype HLA-Cw*0602-B57-DRB1*0701-DQA1*0201-DQB1*0201 was present at a significantly higher frequency in type I patients (P < 0.00001; RR = 7.72). However, this haplotype was not detected at all in patients with type II psoriasis. In conclusion, the extended haplotype HLA-Cw*0602-B57-DRB1*0701-DQA1*0201-DQB1*0201 is a risk haplotype for type I disease in the Croatian population. This particular haplotype has not been reported previously in association with psoriasis in any other ethnic groups.     

Association of HLA-DQA1 and DQB1 genes with vitiligo in Chinese Hans

BACKGROUND: Vitiligo is an acquired depigmentary disorder of the skin and hair which results from selective destruction of melanocytes. Serological typing and genotyping of human leukocyte antigen (HLA) have shown discrepancies in HLA associations with vitiligo in different ethnic populations. METHODS: Polymerase chain reaction sequence-specific primer (PCR-SSP) method was used to analyze the distribution of HLA-DQA(1) and -DQB(1) alleles among 187 patients with vitiligo and 273 healthy controls through Epi Info version 6 package (Centers for Disease Control and Prevention, Atlanta, GA, USA). RESULTS: The frequencies of HLA-DQA1*0302 (OR = 1.98, P(c) < 0.01), -DQB1*0303 (OR = 3.14, P(c) < 0.001), and -DQB1*0503 (OR = 3.36, P(c) < 0.05) alleles were significantly increased in patients with vitiligo compared with controls, and HLA-DQA(1)*0501 (OR = 0.40, P(c) < 0.01) allele frequency was highly decreased. HLA-DQA1*0302 (OR = 5.19, P(c) < 0.001), -DQA1*0601 (OR = 2.95, P(c) < 0.05), -DQB1*0303 (OR = 4.50, P(c) < 0.001), and -DQB1*0503 (OR = 6.69, P(c) < 0.001) alleles were positively associated, whereas HLA-DQA1*0501 (OR = 0.05, P(c) < 0.001) allele was negatively associated with childhood vitiligo patients, and HLA-DQB1*0303 (OR = 2.76, P(c) < 0.001) allele was positively associated with adult vitiligo patients compared with controls. The frequency of HLA-DQB1*0303 (OR = 3.72, P(c) < 0.001) allele was significantly increased in localized vitiligo patients vs. controls, whereas HLA-DQA1*0302 (OR = 2.47, P(c) < 0.01), -DQB1*0303 (OR = 2.67, P(c) < 0.01), and -DQB1*0503 (OR = 4.46, P(c) < 0.01) allele frequencies were significantly increased and -DQA1*0501 (OR = 0.27, P(c) < 0.01) allele frequency was highly decreased in generalized vitiligo patients. CONCLUSIONS: HLA-DQA1*0302, -DQA1*0601, -DQB1*0303, and -DQB1*0503 alleles could be susceptible alleles of vitiligo, while HLA-DQA1*0501 allele could be a protective allele in Chinese Hans. There may be different genetic backgrounds between vitiligo patients of childhood and adult, localized and generalized.     

Association of HLA haplotype with alopecia areata in Chinese Hans

BACKGROUND: Some studies have shown discrepancies in human leucocyte antigen (HLA) associated with alopecia areata (AA) between different ethnic populations. OBJECTIVE: To investigate whether HLA-I, -DQA1 and -DQB1 alleles and the HLA haplotype are associated with AA, and the correlation between the HLA haplotype profile, age of onset and severity of AA in Chinese Hans. METHODS: The polymerase chain reaction-sequence specific primer (PCR-SSP) method was used to analyse the frequencies of HLA class I, -DQA1 and -DQB1 alleles in 192 patients with AA and 252 controls in Chinese Hans. The linkage disequilibrium was calculated using the 2 x 2 table. RESULTS: The 24 two-locus haplotypes [including A*02-B*18, A*02-B*27, A*02-B*52, A*02-Cw*0704, A*02-DQA1*0104, A*02-DQB1*0604, A*02-DQB1*0606, B*18-Cw*0704, B*18-DQA1*0104, B*18-DQA1*0302, B*18-DQB1*0606, B*27-Cw*0704, B*27-DQA1*0104, B*27-DQA1*0302, B*52-Cw*0704, B*52-DQA1*0104, B*52-DQA1*0302, B52-DQB1*0606, Cw*0704-DQA1*0104, Cw*0704-DQA1*0302, Cw*0704-DQB1*0606, DQA1*0104-DQB1*0604, DQA1*0104-DQB1*0606, DQA1*0302-DQB1*0606 (P<0.05)] were associated with AA, while eight extended haplotypes (A*02-B*18-DQA1*0104, A*02-B*27-DQA1*0104, A*02-B*52-DQA1*0104, A*02-B*52-DQA1*0302, A*02-B*52-DQB1*0606, B*52-Cw*0704-DQA1*0104, B*52-Cw*0704-DQA1*0302, A*02-B*52-DQA1*0302-DQB1*0606) were found to be related to AA in Chinese Hans. Through stratified analysis, we found that the extended haplotype B*52-Cw*0704-DQA1*0302 was related to early onset of AA, and no haplotype was only associated with severe AA. CONCLUSION: This is the first detailed report to elucidate HLA haplotypes associated with AA and that demonstrates the significant HLA haplotypes in Chinese Hans AA. The haplotype B*52-Cw*0704-DQA1*0302 was identified to be related to early onset of AA. Our results provide some information for future research on predisposing genes in HLA regions in Chinese Hans.     

SLE患者抗U1 RNP抗体与HLA-Ⅱ类基因的相关性分析

目的 探讨云南汉族系统性红斑狼疮（SLE）患者抗U1RNP抗体与HLA－DRB1、DQA1、DQB1等3位基因及单体型的相关性。方法 采用多聚酶链反应－序列特异性引物（PCR－SSP）技术对63例云南汉族SLE患者进行DRB1、DQA1、DQB1基因分型。结果 抗U1RNP抗体阳性的SLE病人中DQA1＊0101及DR15－DQA1＊0102－DQB1＊0601单体型频率亦显著增高（P＝0．040，P＝0．000）。结论 云南汉族SLE抗U1RNP抗体的产生与DQA1＊0101等位基因及DR15－DQA1＊0102－DQB1＊0601单体型相关。     

Haplotype associations of the MHC with psoriasis vulgaris in Chinese Hans

Summary Haplotype associations of the major histocompatibility complex (MHC) with psoriasis vulgaris (PV) have been demonstrated in different racial or ethnic populations. The objective of this study was to demonstrate the different haplotype associations of the MHC in Chinese patients with psoriasis according to the type of onset and their sex. One hundred and thirty-eight patients with PV and 149 normal control subjects without psoriasis were typed for HLA-A, -B, -C, -DQA1, -DQB1 and -DRB1 by using the PCR with sequence-specific primers. The results showed: (i) HLA-A*26 (26.1% vs. 12.1%, Pc < 1 x 10(-5)), -B*27 (17.03% vs. 1.01%, Pc < 1 x 10(-7)), -Cw*0602 (15.58% vs. 5.03%, Pc < 1 x 10(-2)), -DQA1*0104 (19.93% vs. 9.40%, Pc < 1 x 10(-3)), -DQA1*0201 (22.40% vs. 10.74%, Pc < 1 x 10(-3)), -DQB1*0303 (18.12% vs. 9.73%, Pc < 1 x 10(-7)), and -DRB1*0701/02 (26.09% vs. 9.73%, Pc < 1 x 10(-7)) were significantly increased in PV patients, while HLA-B*57, -DQB1*0201 were slightly increased in PV patients. HLA-Cw*0304 (5.07% vs. 14.43%, Pc < 1 x 10(-3)), -DQA1*0501 (5.79% vs. 14.09%, Pc < 0.05) were found to be negatively associated with PV, but HLA-A*2 (2.54% vs. 6.38%, Pc < 0.5) was decreased in PV patients without statistical significance. (ii) HLA-A*26-B*27 [P < 0.0001, odds ratio (OR) = 48.38], -A*26-Cw*0602 (P < 0.0001, OR = 11.84), -B*27-Cw*0602 (P < 0.0001, OR = undefined), -DRB1*0701/02-B*27 (P < 0.0001, OR = 22.62), -DRB1*0701/02-DQA1*0104 (P < 0.0002, OR = 3.59), -DRB1*0701/02-DQB1*0303 (P < 0.0001, OR = 5.63), -DQA1*0201-DQB1*0303 (P < 0.0002, OR = 7.77), -A*26-B*27-Cw*0602 (P < 0.0004, OR = undefined), -A*26-DRB1*0701/02-DQA1*0201-DQB1*0303 (P < 0.01, OR = undefined) were identified as risk haplotypes for patients with PV in China. (iii) HLA-A*26 -B*27 (P < 0.0001, OR = 58.47), -DQA1*0201-DQB1*0303 (P < 0.0001, OR = 8.62), -DRB1*0701/02 -DQA1*0104 (P < 0.0002, OR = 4.13), -DRB1*0701/02-DQB1*0303 (P < 0.0001, OR = 6.68) and -A*26-DRB1*0701-DQA1*0201 -DQB1*0303 (P < 0.006, OR = undefined) were only significantly associated with type I psoriasis compared with controls, while others showed no differences in either type I or type II psoriasis. (iv) These associated haplotypes with PV were not different by sex, except that the frequency of DRB1*0701/02-DQB1*0303 (P < 0.0001, OR = 10.14) was higher in male patients with psoriasis. To summarize, this study demonstrated a differential association of HLA and identified some special risk haplotypes in Chinese patients with PV compared with other ethnic or racial populations.