Three 5’-flanking Regions of crtO Encoding β-carotene Oxygenase in Haematococcus pluvialis

Three separate 5＇-flanking regions （1.1 kb, 1.9 kb and 2.2 kb） of crtO were cloned through walking upstream. Results of sequence analysis show that three 5＇-flanking regions of crtO might have some similar putative cis-acting elements such as ABA （abscisic acid）-responsive element （ABRE）, C-repeat/dehydration responsive element （C-repeat/DRE）, light-responsive element （G-box, GAG-motif, I-box and ATC-motif）, wound-responsive element （WUN-motif）, auxin-responsive element （TGA-element）, MeJA-responsive element （TGACG-element） and MYB binding site （MBS）, except for typical TATA box or CCAAT box. These findings might mean diversiform regulatory patterns of crtO being in astaxanthin biosynthesis of Haematococcus pluvialis.

Genomic structure analysis of SNC6, a progesterone-receptor associated protein gene, and cloning and characterization of its 5＇-flanking region

Objective: To analyze the genomic structure of SNC6, a progesterone\|receptor associated protein gene and its regulatory elements in its 5'\|flanking region. Methods: Genomic sequence from GenBank database (accession number: Z98048) covering the whole SNC6 gene was used to analyze the genomic structure of SNC6 and design primers for PCR amplification of its 5'\|flanking region. A 1894 bp fragment of the 5'\|flanking region \{(-1814\} to +75) was cloned by PCR using genomic DNA from a healthy donor peripheral blood lymphocyte as template. This fragment, as well as 3 shorter derivative fragments (1423 bp, 632 bp and 416 bp, which correspond to -1344 to +75, -552 to +75 and -337 to +75 respectively), were subcloned into pGL2 series luciferase reporter vectors. These constructs were introduced into colorectal cancer cell line SW620 for transient expression of reporter gene and luciferase activities were measured. Results: The genomic structure analysis showed there are 12 exons for SNC6 gene, which spans 32017 bp (nt71529 to nt39513 in Z98048 sequence). All transfected SW620 cells with the above 5\|flanking region\|containing constructs showed luciferase activities. The highest luciferase activities were measured in transfected cells with vectors containing 1894 bp fragments, and the lowest luciferase activities were measured in transfected cells with vectors containing 416 bp fragments. Luciferase activities were higher in transfected cells with vectors containing 632 bp fragments than that in transfected cells with vectors containing 1423 bp fragments. Conclusion: The basic transcription\|promoting element (promoter) for SNC6 expression resides between 0 to -337, and two transcription\|enhancing elements (enhancer) resides between -337 to -552 and -1344 to -1814, whereas one transcription\|inhibiting element (silencer) exists between -552 to -1344.

绵阳地区5岁以下儿童潮气呼吸肺功能检测指标正常值范围研究

目的研究绵阳地区5岁以下儿童潮气呼吸肺功能检测指标正常值范围。方法从2021年9月至2022年10月采用整群抽样法按照1∶1∶1比例选取在绵阳市妇幼保健院儿科门诊就诊经检查未患病的健康儿童、儿童保健科体检的健康儿童以及5家幼儿园5岁以下健康儿童共456例。检测潮气呼吸肺功能指标[潮气量(VT)、公斤潮气量(VT/kg)、分钟通气量(MV)、呼吸频率(RR)、吸气时间(Ti)、呼气时间(Te)、吸呼时间比(Ti/Te)、吸呼总时间(Ttot)、呼气峰流量(PTEF)、吸气峰流量(PTIF)、达峰时间比(TPTEE/TE)、达峰容积比(VPEF/VE)、呼出75%流量(TEF75)、呼出50%流量(TEF50)、呼出25%流量(TEF25)、吸呼50%流量比(TEF50/TIF50)]。获取不同性别、不同年龄段健康儿童潮气呼吸肺功能检测指标正常值范围,并分析其相关因素。结果所选儿童男性占比56.58%,女性占比43.42%;1个月至2岁、>2~3岁、>3~4岁、>4~<5岁占比分别为11.84%、12.06%、45.84%、30.26%,密切接触吸烟人员占比64.69%;建立了不同性别、不同年龄段潮气呼吸肺功能检测指标的正常值范围,且不同性别儿童VT、VT/kg、MV、RR、PTEF、TEF75、TEF50、TEF25比较,差异有统计学意义(P<0.05),不同年龄儿童VT、VT/kg、MV、RR、PTEF、TEF75、TEF50、TEF25、PTIF、Ti比较,差异有统计学意义(P<0.05);年龄、身高、体质量、每日运动时间与VT、MV、PTEF、PTIF、TEF25均呈正相关,与RR均呈负相关,密切接触吸烟与上述指标均呈负相关,差异有统计学意义(P<0.05)。结论建立了绵阳地区5岁以下儿童潮气呼吸肺功能检测指标的正常值范围,且与年龄、身高、体质量、每日运动时间、是否密切接触吸烟均有关。

Polymorphism Analysis of the 3′ Flank Region of Equine IGF-Ⅰ Gene by PCR-SSCP

[Objective] To explore the polymorphism of the 3′ flank region of equine IGF-Ⅰ gene. [Method] The 3′ flank region sequences of IGF-Ⅰ gene were amplified from genomic DNA of 270 horses, which included 4 types of Mongolian horse, Sanhe horse and Thoroughbred, and then analyzed by PCR-SSCP. [Result] Three genotypes (AA, BB and AB) were detected by PCR-SSCP and the distribution of genotypes of all research objects except Xinihe horse and Baerhu horse were in line with the "Hardy-Weinberg Law". [Conclusion] There was a polymorphic locus in the 3′ flank region of IGF-Ⅰ gene, which might affect the equine growth and development mechanism. The study is of important theoretical and practical significance to improve the performance and to develop equine industry.

Study on the Knockout and the Soluble Prokaryotic Expression of VP5 Protein Transmembrane Region of IBDV

[Objective] The research aimed to construct the prokaryotic expression vector of VP5 protein of IBDV.The transmembrane region sequence of VP5 protein was knocked out.Moreover,the expression,separation and purification of objective protein were carried out.[Method] PCR technology was used to respectively amplify the extracellular and intracellular fragments of VP5 gene of IBDV.Then,the two fragments were simultaneously linked to pET-28b（＋）,and it was the vector-intracellular fragment-extracellular fragment-vector.The recombinant expression plasmid pET-VP5-FC and the improved pET-VP5-SC of VP5 whose transmembrane region gene fragment was knocked out were constructed.Then,the expression plasmid was transformed into BL21（DE3）.After IPTG induction,the recombinant protein was purified by Ni affinity chromatography and the gel filtration chromatography.[Result] The soluble expressed VP5 of IBDV was obtained.[Conclusion] The research laid the foundation for further studying the structure and function of VP5 protein.

抑郁模型大鼠不同脑区5-HT_(1A)蛋白表达及加味温胆汤的干预作用

目的:基于不同脑区5-HT_(1A)蛋白表达,探讨模型大鼠抑郁发病机制以及加味温胆汤的干预作用。方法:将32只SPF级雄性SD大鼠(体质量180~200 g)随机分为正常对照组、抑郁模型组、抑郁中药组、抑郁西药组各8只。采用慢性轻度不可预见性应激制作大鼠抑郁模型,其中正常对照组、抑郁模型组大鼠灌胃生理盐水,抑郁中药组灌胃12 g/kg加味温胆汤,抑郁西药组灌胃1.8 mg/kg百忧解。35天后进行行为学检测及取材,通过Western blot法检测各组大鼠杏仁核、前额皮质、海马CA3区及下丘脑组织中5-HT_(1A)蛋白表达。结果:行为学数据显示,抑郁模型组大鼠水平运动次数、垂直运动次数以及总路程较正常对照组减少(P<0.05),抗抑郁西药百忧解只对总路程有影响(P<0.05),而加味温胆汤能改善模型大鼠抑郁行为表现(P<0.05),提高水平运动、垂直运动次数,延长总路程。抑郁模型组大鼠海马CA3区5-HT_(1A)蛋白表达水平升高,加味温胆汤能降低海马CA3区5-HT_(1A)蛋白表达(P<0.05),百忧解能提高杏仁核5-HT_(1A)蛋白表达(P<0.05)。结论:抑郁模型大鼠不同脑区5-HT_(1A)蛋白表达不一致,抑郁模型大鼠海马CA3区5-HT_(1A)蛋白表达升高,加味温胆汤可能通过降低抑郁模型大鼠海马CA3区5-HT_(1A)蛋白表达发挥抗抑郁作用,而百忧解能提高杏仁核5-HT_(1A)蛋白表达,其抗抑郁机制有待进一步阐明。

自拟安神方对心肾不交证失眠大鼠皮质区和海马区5-HT和DA信号通路影响

目的探索自拟安神方(简称安神方)对大鼠不同脑区5-羟色胺(5-hydroxytryptamine,5-HT)和多巴胺(dopamine,DA)信号通路的影响,揭示安神方抗大鼠心肾不交证失眠的机制。方法将SD雄性大鼠随机分为正常组,模型组,阳性对照组,安神方高、中、低剂量组,每组10只。除正常组外,其他各组采用多因素方法制备改良的心肾不交证失眠大鼠模型,灌胃治疗2周。HE染色观察大鼠脑组织形态结构。高效液相色谱-电化学法(HPLC-ECD)检测大鼠皮质区和海马区DA和5-HT的含量。免疫蛋白印迹法检测5-HT信号通路上5-HT_(1A)受体、5-HT_(2A)受体、磷酸腺苷反应元件结合蛋白(cAMP-response element binding protein,CREB)、蛋白激酶A(protein kinase A,PKA)和DA信号通路上D_(1)R_(1)在皮质区和海马区的蛋白表达。结果HE染色显示模型组皮质区神经元有少量的凋亡,海马结构区变化不明显;安神方组皮质区神经元凋亡有所减轻。HPLC-ECD结果显示,与正常组比较,模型组皮质区和海马区DA含量均升高(P<0.05),5-HT含量均显著下降(P<0.05);与模型组比较,安神方组皮质区和海马区DA含量显著降低(P<0.05),同时海马区5-HT含量有所提高(P<0.05)。免疫印迹结果显示,与正常组比较,模型组皮质区5-HT_(1A)和CREB蛋白表达降低(P<0.05),海马区D_(1)R_(1)蛋白表达升高(P<0.05);与模型组比较,安神方组皮质区5-HT_(1A)和信号通路上关键蛋白CREB的蛋白表达上调(P<0.05),并且海马区D_(1)R_(1)的蛋白表达下调(P<0.05),其信号通路上CREB蛋白表达差异虽无统计学意义,但各给药组仍有上调趋势。结论安神方抗心肾不交证失眠的机制可能与抑制皮质区神经元凋亡,并促进皮质区和海马区5-HT通路功能、抑制DA通路功能有关。

Quasispecies evolution in NS5A region of hepatitis C virus genotype 1b during interferon or combined interferon-ribavirin therapy

AIM: To evaluate the implication of substitutions in the hepatitis C virus (HCV) non-structural 5A (NS5A) protein in the resistance of HCV during mono-interferon (IFN) or combined IFN-ribavirin (IFN-R) therapy. Although NS5A has been reported to interact with the HCV RNA- dependent RNA polymerase, NS5B, as well as with many cellular proteins, the function of NS5A in the life cycle of HCV remains unclear. METHODS: HCV quasispecies were studied by clon- ing and sequencing of sequential isolates from patients infected by HCV genotype 1b. Patients were treated by IFN-α2b for 3 mo followed by IFN-α2b alone or com- bined IFN-R therapy for 9 additional months. Patients were categorized intro two groups based on their re- sponse to the treatments: 7 with sustained virological re- sponse (SVR) (quasispecies = 150) and 3 non-respond- ers (NR) to IFN-R (quasispecies = 106). RESULTS: Prior to treatment, SVR patients displayed a lower complexity of quasispecies than NR patients. Most patients had a decrease in the complexity of quasispe- cies during therapy. Analysis of amino acids substitu- tions showed that the degree of the complexity of the interferon sensitivity-determining region (ISDR) and the V3 domain of NS5A protein was able to discriminate thetwo groups of patients. Moreover, SVR patients displayed more variability in the NS5A region than NR patients. CONCLUSION: These results suggest that detailed mo- lecular analysis of the NS5A region may be important for understanding its function in IFN response during HCV 1b infection.

Future Precipitation Extremes in China under Climate Change and Their Physical Quantification Based on a Regional Climate Model and CMIP5 Model Simulations

The atmospheric water holding capacity will increase with temperature according to Clausius-Clapeyron scaling and affects precipitation.The rates of change in future precipitation extremes are quantified with changes in surface air temperature.Precipitation extremes in China are determined for the 21st century in six simulations using a regional climate model,RegCM4,and 17 global climate models that participated in CMIP5.First,we assess the performance of the CMIP5 models and RCM runs in their simulation of extreme precipitation for the current period(RF:1982-2001).The CMIP5 models and RCM results can capture the spatial variations of precipitation extremes,as well as those based on observations:OBS and XPP.Precipitation extremes over four subregions in China are predicted to increase in the mid-future(MF:2039-58)and far-future(FF:2079-98)relative to those for the RF period based on both the CMIP5 ensemble mean and RCM ensemble mean.The secular trends in the extremes of the CMIP5 models are predicted to increase from 2008 to 2058,and the RCM results show higher interannual variability relative to that of the CMIP5 models.Then,we quantify the increasing rates of change in precipitation extremes in the MF and FF periods in the subregions of China with the changes in surface air temperature.Finally,based on the water vapor equation,changes in precipitation extremes in China for the MF and FF periods are found to correlate positively with changes in the atmospheric vertical wind multiplied by changes in surface specific humidity(significant at the p<0.1 level).

Future temperature changes over the critical Belt and Road region based on CMIP5 models

Based on data of 22 models from the Coupled Model Inter-comparison Project Phase 5(CMIP5),the performance of climate simulation is assessed and future changes under RCP2.6,RCP4.5 and RCP8.5 are projected over critical Belt and Road region.Compared with observations,the CMIP5 models simulate the linear trend and spatial distribution of the annual mean surface air temperature(SAT)better in the north(NBR)and south(SBR)of the Belt and Road region.The trend of the 22-model ensemble mean(CMIP5 MME)is 0.70/0.50
C per 100 years from 1901 to 2005,and the observed trend is 1.11/0.77
C per 100 years in the NBR/SBR region.After 1971,the relative error between CMIP5 MME and observations is 22%/15%in the NBR/SBR region.Seven/nine models are selected in the NBR/SBR to project future SAT changes under three RCP scenarios.For 2081e2100,warming in the NBR/SBR is projected to be(1.16±0.29)/(0.72±0.32)
C,(2.41±0.54)/(1.55±0.44)
C,and(5.23±1.02)/(3.33±0.65)
C for RCP2.6,RCP4.5,and RCP8.5,respectively.Under the RCP scenarios,the NBR region shows greater warming than the SBR region.The most significant warming is expected in Kazakhstan and the northern part of the SBR.The associated uncertainty generally increases with time under the three RCP scenarios.Furthermore,increases in warming over the Belt and Road region are more remarkable under higher-emission scenarios than lower-emission ones.

Projected changes in mean and extreme climates over Hindu Kush Himalayan region by 21 CMIP5 models

Based on the outputs from 21 CMIP5 (Coupled Model Intercomparison Project phase 5) models, future changes in the mean temperature, precipitation and four climate extreme indices (annual maximum of daily maximum temperature (TXx), minimum of daily minimum temperature (TNn), annual total precipitation when the daily amount exceeds the 95th percentile of wet-day precipitation (R95p), and maximum consecutive 5-day precipitation (RX5day)) over Hindu Kush Himalayan (HKH) region are investigated under the greenhouse gas concentration pathways of RCP4.5 and RCP8.5. Two periods of the 21st century, 2036e2065 and 2066e2095, are selected, with the reference period is considered as 1976e2005. Results show general increase of the mean temperature, TXx and TNn under both scenarios, with the largest increases found during 2066e2095 under RCP8.5. Future precipitation is projected to increase over most part of HKH, except for the northwestern part. Intensification of the precipitation extremes is projected over the region. The uncertainties of mean temperature, TXx and TNn over the HKH1 subregions are the largest compared to the other three subregions and the overall HKH. Besides RX5day during 2036e2065 over HKH1, the uncertainties of R95p and RX5day tend to be larger following the increase of greenhouse gas concentrations. The multimodel ensemble medians of temperature and four extreme indices under RCP8.5 are projected to be larger than those under RCP4.5 in each of the subregions.

Functional characterization of a Δ6 fatty acid desaturase gene and its 5′-upstream region cloned from the arachidonic acid-rich microalga Myrmecia incisa Reisigl(Chlorophyta)

It is suggested that Δ6 fatty acid desaturase(FAD) plays a critical role in the biosynthesis of polyunsaturated fatty acids in plants and microalgae. But why does it adapt to the changed environments such as nitrogen starvation is seldom understood. One Δ6 FAD gene( MiD6 fad) from an arachidonic acidrich microalga M yrmecia incisa Reisigl(Chlorophyta) was first heterologously expressed in S accharomyces cerevisiae for the identification of function. The fatty acid profile of transgenic yeast detected by gas chromatography-mass spectrometry illustrated that the enzyme MiD6 FAD could convert linoleic and ?-linolenic acids to γ-linolenic and stearidonic acids, respectively, demonstrating that M iD6 fad encoded a Δ6 FAD. A 1 965-bp fragment of the cloned 2 347-bp 5′-upstream region of M iD6 fad was next subcloned and fused upstream with green fluorescent protein(GFP) gene to replace the GAL1 promoter of the vector pYES2. The generated construct was transformed into S. cerevisiae for function determination. Confocal microscopic images of the transformed line illustrated that this inserted fragment could drive GFP expression, which was further verified by fluorescence intensity quantification and Western blot analysis using antiGFP antibody. The conversion efficiency(approximately 2%-3%) of MiD6 FAD was much lower than the reported ? 3 FAD and Δ6 elongase in this microalga, suggesting that MiD6 FAD catalysed the possible ratelimiting step for ArA biosynthesis. The presence of several putative c is-acting regulatory elements in this identified promoter sheds new light on the regulation mechanism research of Δ6 FAD transcription for the ArA production in M. incisa in changing environmental factors.

The hepatitis C virus 5’ untranslated region gene amplified by rapid amplification of cDNA ends and its secondary structure

Objectives: To obtain very end full-length cDNA ofhepatitis C virus (HCV) 5’ untranslated region(5’UTR) and analyze its primary and secondarystructure.Methods: A patient infected genotype 2a HCV wasidentified by reverse transcription-nested polymerasechain reaction (RT-PCR) and restriction fragmentlength polymorphism (RFLP). Total RNA isolatedfrom the serum was used as template, and the cDNAof the 5’ untranslated region was amplified using rap-id amplification of cDNA ends (RACE). The frag-ments were recombinated by A-T clone strategy, andthe recombinants were confirmed by RFLP andPCR, and sequenced subsequently. Secondary struc-tures were analysed by RNAdraw.Results: Very end full-length cDNA of genotype 2aHCV 5’ UTR was obtained by RACE. In five clonesobtained, three contained full-length 5’UTR cDNA;A21G, G170A, T222C, T247C, C339T substitutionswere found as compared to HC-J6. Homological re-sults of HCV-1, HC-J6, HC-C2, HC-J8 were 93.6%-94.4%, 92.1%-93%, 98.8%-99.7%, 96.2%-96.5%, respectively; however, the substitutions didnot alter secondary structure. Two of 5 clones weredeletions of 53bp and 135bp at the 5’terminal ofHCV 5’UTR, respectively.Conclusions: RACE can be used to obtain the full-length cDNA of 2a genotype HCV 5’UTR. Genes de-leted at the 5’ terminal of HCV circulate in hepatitisC patients.

5-HTTLPR基因多态性与惊恐障碍发病风险关系的Meta分析

目的系统评价5-羟色胺转运体启动子区(5-HTTLPR)基因多态性与惊恐障碍(PD)发病风险的关系。方法利用PubMed、Embase、中国知网、维普网和万方数据知识服务平台等数据库检索5-HTTLPR基因多态性与PD发病风险关系的相关文献,根据异质性检验结果,采用固定效应模型分析总体人群及以种族划分为亚组人群5种基因遗传模型下5-HTTLPR基因多态性与PD发病风险的关系。结果共纳入合格文献11篇,包括PD组1431例,对照组2148例。在总体人群及以种族划分为亚组人群中,5种基因遗传模型下5-HTTLPR基因多态性与PD发病风险均无关(均P>0.05)。结论5-HTTLPR基因多态性可能与PD发病风险无关。

Geochemical Characteristics of C_5–C_7 Light Hydrocarbons in Gas Hydrates from the Permafrost Region of Qilian Mountains

As an important part of gas hydrates, light hydrocarbons （LHs）, especially C5 to C7 hydrocarbons with various monomer compounds, provide a wide variety of geological and geochemical information, which have received much attention from organic geochemists and petroleum geologists.

Evolutionary relationship of 5′-untranslated regions among Thai dengue-3 viruses,Bangkok isolates,during 24 year-evolution

Objective:To study evolutionary relationship of the 5'untranslated regions(5'UTRs) in low passage dengue3 viruses(DEN3) isolated from hospitalized children with different clinical manifestations in Bangkok during 24 year-evolution(1977-2000) comparing to the DEN3prototype(H87).Methods:The 5'UTRs of these Thai DEN3 and the H87 prototype were amplified by RT-PCR and sequenced.Their multiple sequence alignments were done by Codon Code Aligner v 4.0.4 software and their RNA secondary structures were predicted by MFOLD software.Replication of five Thai DEN3 candidates comparing to the 1187 prototype were done in human(HepG2) and the mosquito(C6/36) cell lines.Results:Among these Thai DEN3,the completely identical sequences of their first 89 nucleotides,their high-order secondary structure of 5'UTRs and three SNPs including the predominant C90 T,and two minor SNPs including A109 G and A112 G were found.The C90 T of Thai DEN3.Bangkok isolates was shown predominantly before 1977.Five Thai DEN3 candidates with the predominant C90 T were shown to replicate in human(HepG2) and the mosquito(C6/36) cell lines better than the H87 prototype.However,their highly conserved sequences as well as SNPs of the 5'UTR did not appear to correlate with their disease severity in human.Conclusions:Our findings highlighted evolutionary relationship of the completely identical 89 nucleotide sequence,the high-order secondary structure and the predominant C90 T of the 5'UTR of these Thai DEN3 during 24 year-evolution further suggesting to be their genetic markers and magic targets for future research on antiviral therapy as well as vaccine approaches of Thai DEN3.

Association Analysis between a Polymorphism in the 5' Regulatory Region of the IL-6 Gene and Litter Size in Pigs

The aim of this study was to determine the effects of an IL-6 gene polymorphism, discovered in the 5＇ regulatory region, on porcine litter size. An association analysis was performed between the polymorphism and total number born （TNB） and number born alive （NBA） in 421 sows. The polymorphism was at Hpy188I within the 5＇ regulatory region of IL- 6 gene. Three genotypes of AA, AG, and GG were detected in Landrace, and two genotypes, AA and AG, were detected in Yorkshire and Duroc pigs. The A allele was the superior allele in all three breeds, with allele frequencies ranging from 0. 901 to 0.993. The IL-6 genotype was highly significantly associated with TNB and NBA in the third and following parities （ P 〈 0.01 ）, and with total parities （ P 〈 0.05）. In general, the TNB and NBA showed a tendency of GG 〉 AG 〉 AA, indicating that the common allele was the least favorable for litter size. Thus, there is an enormous opportunity to increase litter size if this effect is confirmed in other studies.

Point mutation of 5' noncoding region of BCL-6gene in primary gastric lymphomas

AIM: To investigate the mutations of the 5' noncoding region of BCL-6 gene in Chinese patients with primary gastric lymphomas. METHODS: PCR and direct DNA sequencing were used to identify BCL-6 gene mutations in the 5' noncoding region in 29 cases of gastric diffuse large B-cell lymphoma (DLBCL) and 18 cases of gastric mucosa-associated lymphoid tissue (MALT) lymphoma as well as 10 cases of reactive hyperplasia of lymph node (LRH). RESULTS: Six of 29 gastric DLBCLs (20.7%), 4 of 18 gastric MALT lymphomas (22.2%) and 1 of 10 LRHs(10%) were found to have mutations. All mutations were single-base substitutions and the frequency of single-base changes was 0.20×1O^(-2)-1.02×1O^(-2)per bp. CONCLUSION: Point mutations in the 5' noncoding region of BCL-6 gene are found in Chinese patients with primary gastric DLBCLs and MALT lymphomas, suggesting that they may, in some extent, participate in the pathogenesis of primary gastric DLBCLs and MALT lymphomas.

Hepatitis C virus NS5A region mutation in chronic hepatitis C genotype 1 patients who are non-responders to two or more treatments and its relationship with response to a new treatment

To determine the number of mutations in the NS5A region of the hepatitis C virus (HCV) and its relationship to the response to antiviral therapy in patients with chronic hepatitis C genotype 1 who are non-responders to two or more treatments. METHODSSequences within HCV NS5A [PKR binding domain (PKRBD) and the interferon-sensitivity-determining region (ISDR)] were analysed via direct sequencing in a selected cohort of 72 patients, with a total of 201 treatments [interferon-alpha (IFN-α), n = 49; IFN-α + ribavirin (RBV), n = 75; pegylated (peg) IFN-α + RBV, n = 47; first-generation direct-acting antivirals (DAAs), n = 13; and second-generation DAAs, n = 17]. Of these, 48/201 achieved a sustained virological response (SVR) and 153/201 achieved no virological response (NVR). RESULTSFor both regions, treatments resulting in SVR were associated with more baseline mutations than were treatments resulting in NVR (SVR vs NVR; PKRBD: 5.82 ± 3 vs 4.86 ± 2 mutations, P = 0.045; ISDR: 2.65 ± 2 vs 1.51 ± 1.7 mutations, P = 0.005). A decrease or no change in the number of mutations over time between treatments in the PKRBD or ISDR, as shown by sequencing, was associated with patients who usually failed to respond to treatment (PKRBD, P = 0.02; ISDR, P = 0.001). Moreover, patients showing a post-treatment baseline viral load > 600000 IU/mL and increased ISDR mutations with respect to the previous treatment were 9.21 times more likely to achieve SVR (P = 0.001). CONCLUSIONThe obtained results show that among patients who have shown no response to two or more antiviral treatments, the likelihood of achieving SVR increases with the genetic variability in the ISDR region (≥ 2 mutations or number of substitutions from the HCV-J and HCV-1 prototype), especially when the viral load is greater than 600000 IU/mL.

TYMS gene 5'-and 3'-untranslated region polymorphisms and risk of non-syndromic cleft lip and palate in an Indian population

Dear Editor： Increased homocysteine levels due to vitamin B6 or B12 deficiency or genetic defects in folate pathway genes are associated with an increased incidence of non-syndromic cleft lip with or without cleft palate （NSCLP）tlj. Thymidylate synthase （TS） is a folate-dependent enzyme that catalyzes methylation of 2＇-deoxyuridine-5＇-monophosphate （dUMP） to 2＇-deox- ythymidine-5＇-monophosphate （dTMP）, a rate-limiting step in DNA synthesis,