急性心肌梗死患者心理弹性水平与生活质量、焦虑抑郁和医学应对方式的相关性分析

摘要 目的：分析急性心肌梗死（AMI）患者心理弹性水平与生活质量、焦虑抑郁和医学应对方式的相关性。方法：选取2019年3月~2020年8月期间我院收治的AMI患者142例。分别采用心理弹性量表(CD-RISC)、生活质量自评量表 (WHOQOL-BREF)、Zung焦虑自评量表(SAS)、Zung抑郁自评量表(SDS)、医学应对方式问卷(MCMQ)评估所有患者的心理弹性水平、生活质量、焦虑抑郁情况和医学应对方式,并与国内常模对比。采用Pearson相关性分析心理弹性评分与生活质量评分、焦虑抑郁评分和医学应对方式评分的相关性。结果：AMI患者力量、坚韧性、乐观性各维度评分及CD-RISC总分均较国内常模低（P<0.05）。AMI患者心理、生理、社会关系、环境以及WHOQOL-BREF平均分均低于国内常模（P<0.05）。AMI患者SAS、SDS评分均高于国内常模（P<0.05）。AMI患者回避、屈服评分较国内常模高,面对评分低于国内常模（P<0.05）。Pearson相关性分析结果显示：CD-RISC总分与WHOQOL-BREF平均分、面对评分呈正相关,而与SAS、SDS、回避、屈服评分呈负相关（P<0.05）。结论：AMI患者心理弹性水平与焦虑抑郁、生活质量和医学应对方式相关,治疗时应采取相应措施提高患者应对疾病的能力,通过提高AMI患者的心理弹性,缓解其焦虑、抑郁情绪,进而提高生活质量。     

非霍奇金淋巴瘤患者焦虑抑郁情况分析及与病情分期、生活质量的相关性研究

摘要 目的：探讨非霍奇金淋巴瘤（NHL）患者焦虑、抑郁情况,并分析二者与患者病情分期、生活质量的相关性。方法：纳入我院2017年9月～2020年9月收治的NHL患者120例作为NHL组,另选取100例健康志愿者作为对照组,针对两组受试者行焦虑自评量表（SAS）、抑郁自评量表（SDS）评分。根据病情分期将NHL患者分成Ⅰ期组（n=23）、Ⅱ期组（n=40）、Ⅲ期组（n=39）、Ⅳ期组（n=18）,根据患者抑郁、焦虑发生情况分成负面情绪组（n=49）、无负面情绪组（n=71）。利用简明生活质量量表（SF-36）评估生活质量,经Logistic多元回归模型分析NHL患者负面情绪发生的影响因素。结果：NHL组的SDS、SAS评分高于对照组,且Ⅲ期、Ⅳ期组的SDS、SAS评分高于Ⅰ期、Ⅱ期组,Ⅳ期组高于Ⅲ期组（P＜0.05）。负面情绪组躯体功能、躯体疼痛、躯体角色功能、情绪角色功能、心理健康、精力、总体健康评分低于无负面情绪组（P＜0.05）。Pearson线性分析结果显示,SDS、SAS评分与躯体功能、躯体疼痛、躯体角色功能、情绪角色功能、心理健康、精力、总体健康评分呈负相关（P＜0.05）。Logistic多元回归分析结果提示,病情分期Ⅲ～Ⅳ期是NHL患者负面情绪发生的危险因素,受教育年限＞8年、家庭月收入≥5000元是预防负面情绪的保护性因素（P＜0.05）。结论：NHL患者病情分期越高,则焦虑、抑郁越明显,进而降低患者生活质量。     

基于加速康复外科理念的早期康复训练联合八段锦前四式在乳腺癌改良根治术后患者中的应用效果研究

摘要 目的：研究基于加速康复外科（ERAS）理念的早期康复训练联合八段锦前四式在乳腺癌改良根治术后患者中的应用效果。方法：选择2019年9月~2022年5月期间在湖南中医药大学第一附属医院行乳腺癌改良根治术的128例乳腺癌患者。按照随机数字表法将患者分为对照组（基于ERAS理念的早期康复训练,n=64）和研究组（对照组的基础上接受八段锦前四式干预,n=64）。对比两组抑郁自评量表（SDS）评分、健康调查简表（SF-36）、焦虑自评量表（SAS）评分、Constant-Murley肩关节功能评分、疼痛视觉模拟评分（VAS）和肩关节活动度。结果：与对照组相比,研究组干预后SDS、SAS评分更低（P<0.05）。与对照组相比,研究组情感/生理职能、躯体疼痛、社会/生理功能、活力、总体/精神健康评分更高（P<0.05）。与对照组相比,研究组干预后VAS评分更低,Constant-Murley肩关节功能评分更高（P<0.05）。与对照组相比,研究组干预后前屈、后伸、外展关节活动度更大（P<0.05）。结论：基于ERAS的早期康复训练联合八段锦前四式应用于乳腺癌改良根治术后患者,可提高患者的生活质量,可能与缓解焦虑、抑郁情绪,减轻术后疼痛,促进肩关节功能恢复有关。     

溃疡性结肠炎患者生存质量与应对方式、心理状态的关系及其影响因素分析

摘要 目的：探讨溃疡性结肠炎（UC）患者生存质量与应对方式、心理状态的关系,并分析生存质量的影响因素。方法：选取2018年4月~2020年8月期间我院收治的183例UC患者。采用中文版医学应对问卷（MCMQ）评估患者对疾病的应对方式。采用炎症性肠病生存质量问卷（IBDQ）对患者生存质量进行评价。采用焦虑自评症状表（SAS）、抑郁自评症状表（SDS）评估患者心理状态。Pearson相关性分析UC患者生存质量与应对方式、心理状态的关系,应用单因素及多因素Logistic回归分析生存质量的影响因素。结果：UC患者全身症状、肠道症状、社会能力、情感能力、IBDQ总分均低于国内常模（P<0.05）。UC患者SAS、SDS评分均高于国内常模（P<0.05）。UC患者回避、屈服评分均高于国内常模,面对评分低于国内常模（P<0.05）。Pearson相关性分析结果显示：IBDQ总分与SAS、SDS以及回避、屈服评分均呈负相关,与面对评分呈正相关（P<0.05）。单因素分析结果显示：UC患者的生存质量与病情严重程度、婚姻状况、饮酒史、文化程度、性别、家族史、吸烟史、饮食习惯、家庭月均收入、肠道手术史有关（P<0.05）。多因素Logistic 回归分析结果显示：病情严重程度为重度、性别女、有家族史、有吸烟史、不良饮食习惯、家庭月均收入≤5000元均是影响UC患者生存质量的危险因素（P＜0.05）。结论：UC患者生存质量下降,其生存质量与应对方式、心理状态有关,且受到性别、家族史、病情严重程度等多种因素影响,临床可考虑针对上述影响因素进行相关防治,以改善UC患者生存质量。     

综合护理对糖尿病足患者心理状态与生活质量的影响

目的：探讨综合护理对糖尿病足患者心理状态与生活质量的影响。方法：选取52例糖尿病足患者,随机分为照组和试验组,各26例,对照组给予常规护理,试验组采用综合护理进行干预。采用Zung焦虑自评量表（SAS）、抑郁自评量表（SDS）评价两纽患者心理状态,并用社会功能缺陷筛选量表（SDSS）和2型糖尿病生活质量量表（DMQI_,s）对两组患者生活质量进行评价。结果：两组患者干预前SAS、SDS、SDSS、DMQLS评分无差异,实施干预后,两组患者均有SAS、SDS、SDSS评分下降、DMQLS评分升高,但试验组患者SAS、SDS、SDSS评分下降及DMQLS评分升高更明显,与对照组比较,差异有统计学意义（P〈0．01）。结论：综合护理有助于改善糖尿病足患者焦虑、抑郁负性情绪,提高生活质量。     

非小细胞肺癌患者术后抑郁状况的影响因素及与生存质量和睡眠质量的相关性研究

摘要 目的：探讨非小细胞肺癌（NSCLC）患者术后抑郁状况的影响因素,分析术后抑郁与生存质量和睡眠质量的关系。方法：选取2019年1月～2021年1月在韶关市第一人民医院胸外科行手术治疗的 80例NSCLC患者,采用抑郁自评量表（SDS）评估其术后抑郁情况,根据评估结果将患者分为抑郁组（SDS评分≥50分,33例）和非抑郁组（SDS评分＜50分,47例）,单因素及多因素Logistic回归分析NSCLC患者术后抑郁的影响因素。采用肺癌患者生存质量测定量表（FACT-L）中文版（V4.0）、匹兹堡睡眠质量指数量表（PSQI）测评所有患者的生存质量和睡眠质量,Pearson相关性分析SDS评分与FACT-L、PSQI评分之间的关系。结果：抑郁组与非抑郁组间年龄、性别、文化程度、家庭收入水平、医疗费用支付方式、生活能否自理、肺癌TNM分期、术后是否并发肺炎有明显差异（P＜0.05）。进一步多因素分析显示,术后并发肺炎、肺癌TNM分期Ⅲ期、女性、大专以下文化程度是NSCLC患者术后抑郁的危险因素（P＜0.05）。抑郁组FACT-L评分低于非抑郁组,PSQI评分高于非抑郁组（P＜0.05）。SDS评分与FACT-L评分呈负相关,与PSQI评分呈正相关（P＜0.05）。结论：术后并发肺炎、肺癌TNM分期Ⅲ期、女性、文化程度低是影响NSCLC患者术后抑郁的因素,术后抑郁的发生会降低患者的生存质量和睡眠质量。     

八段锦和五行音乐疗法在缓解新型冠状病毒肺炎患者负性情绪中的疗效分析

摘要 目的：观察八段锦和五行音乐疗法对新型冠状病毒肺炎（COVID-19）患者负性情绪的疗效。方法：收集孝感市第一人民医院就诊的COVID-19患者40例，采用随机数字表法将40例患者随机分为对照组（n=20）和观察组（n=20），观察组接受八段锦和子午流注理论指导下的择时五行音乐疗法进行干预，对照组保持日常生活方式。两组在干预前、干预2周采用焦虑自评量表（SAS）和抑郁自评量表(SDS)分别评定两组实验对象在实验前和干预后的负性情绪的改变，用患者生活质量量表(QLQ-C30)分别对两组患者进行生活质量的测评。结果：接受八段锦和子午流注理论指导下的择时五行音乐疗法的患者负性情绪明显减低，SAS、SDS评分明显较前明显改善，观察组患者SAS评分、SDS评分较对照组降低程度明显，差异存在统计学差异（P＜0.05）；干预后观察组、对照组的角色功能、认知功能、情感功能、躯体功能及生活质量评分均明显改善，接受八段锦和子午流注理论指导下的择时五行音乐疗法的患者在角色功能、认知功能、情感功能、躯体功能及生活质量评分方面均优于对照组，差异存在统计学差异（P＜0.05）。结论：COVID-19患者通过八段锦和五行音乐疗法能够明显减低负性情绪，此种疗法可有效起到"精神内守，病安从来"的安慰作用。     

间质性肺疾病患者生活质量与肺功能和焦虑抑郁情绪的关系及其影响因素分析

摘要 目的：探讨间质性肺疾病（ILD）患者生活质量与肺功能和焦虑抑郁情绪的关系及其影响因素。方法：选取2019年3月至2020年10月期间我院收治的100例ILD患者。比较ILD患者与一般人群的圣乔治呼吸问卷（SGRQ）评分、肺功能指标[第1秒用力呼气容积（FEV₁）、用力肺活量（FVC）、肺总量（TLC）及一氧化碳弥散量（DLCo）];观察患者的医院焦虑抑郁量表（HADS）评分（该评分包括焦虑和抑郁评分两部分）;分析ILD患者的SGRQ评分与肺功能指标,焦虑、抑郁评分的相关性;单因素、多因素Logistic回归分析ILD患者生活质量的影响因素。结果：ILD患者的SGRQ各维度评分及总分均高于一般人群,FVC、FEV₁、TLC及DLCo均低于一般人群（P<0.05）;ILD患者焦虑评分和抑郁评分均较高;ILD患者SGRQ各维度评分均与FVC、FEV1、TLC和DLCo呈负相关（P<0.05）,均与焦虑评分和抑郁评分呈正相关（P<0.05）。单因素分析结果显示,不同年龄、是否吸烟、不同收入情况的ILD患者生活质量有差异（P<0.05）;多因素Logistic回归分析结果显示DLCo、FVC、焦虑和抑郁情绪是ILD患者生活质量的影响因素（P<0.05）,其中焦虑情绪对其生活质量的影响最为显著。结论：ILD患者的生活质量与肺功能和焦虑抑郁情绪有关,提示临床工作中可通过干预ILD患者肺功能和焦虑抑郁情绪以改善其生活质量。     

耐多药肺结核患者心理健康状况调查及与应对方式、社会支持的相关性研究

摘要 目的：探讨耐多药肺结核患者心理健康状况的影响因素,分析其及与应对方式、社会支持的相关性。方法：选择2018年4月至2020年5月我院诊治的101例耐多药肺结核患者作为观察组,选择同期99例敏感肺结核患者作为对照组。两组均测评症状自评量表-90(SCL-90)评分、医学应对问卷(MCMQ)评分以及社会支持评定量表(SSRS)评分,分析SCL-90总评分与MCMQ各因子评分、SSRS总评分的相关性,采用Logistic回归模型分析心理健康状况的影响因素。结果：与对照组相比,观察组的躯体化、人际关系、抑郁、焦虑、敌对性、恐怖和精神病性评分以及总评分明显提高（P<0.05）。与对照组相比,观察组的面对评分、客观支持、主观支持、支持利用度评分以及总评分均降低（P<0.05）。Pearson相关性分析显示,SCL-90总评分与MCMQ评分中的回避和屈服评分呈正相关性（r=0.386、0.311,均P<0.05）,SCL-90总评分与SSRS总评分呈负相关（r=-0.332,P<0.05）。多因素Logistic回归分析显示,经济状况差、躯体健康状况差、病情严重、睡眠质量差和生活满意度低是耐多药肺结核患者心理健康不良的独立危险因素（P<0.05）。结论：耐多药肺结核患者心理健康状况差,应对方式选择面对较少,总体社会支持水平较低,患者的心理健康状况与应对方式、社会支持存在一定的相关性。在提供躯体性治疗的基础上,应结合患者的心理健康状况及相关危险因素给予适当干预。     

糖尿病视网膜病变玻璃体切割术患者焦虑状况调查及对血糖控制的影响

摘要 目的：调查糖尿病视网膜病变玻璃体切割术患者的焦虑状况,并分析其对血糖控制的影响。方法：选择2020年1月至2020年12月江苏省人民医院收治的80例糖尿病视网膜病变患者,均行玻璃体切割术治疗,术后2~3天采用焦虑自评量表（SAS）评估患者焦虑程度,并将患者分为焦虑组（SAS评分≥50分）和无焦虑组（SAS评分＜50分）,采用多因素Logistic回归分析发生焦虑的影响因素,比较两组空腹胰岛素（FINS）、C肽、空腹血糖（FPG）、餐后2 h血糖（2hPG）、糖化血红蛋白（HbA1c）水平,采用Pearson相关系数分析SAS评分与血糖水平的相关性。结果：80例糖尿病视网膜病变玻璃体切割术患者SAS得分36～67分,平均（48.35±9.18）分,其中22例SAS评分≥50分,焦虑发生率为27.50%。大专以下文化程度、家庭平均月收入＜6000元、糖尿病病程≥8年是糖尿病视网膜病变玻璃体切割术患者发生焦虑的危险因素（P＜0.05）。焦虑组患者的FPG、2hPG、FINS、C肽、HbA1c水平均高于无焦虑组患者（P＜0.05）。糖尿病视网膜病变玻璃体切割术患者的SAS评分与FPG、2hPG、FINS、C肽、HbA1c水平均呈正相关（r =0.468、0.509、0.538、0.609、0.637,均P＜0.05）。结论：糖尿病视网膜病变玻璃体切割术患者焦虑发生率较高,文化程度、收入水平、糖尿病病程是焦虑发生的影响因素,焦虑情绪会影响患者血糖控制水平,临床应针对性制定防治措施。     

Interactions of the DNA intercalator acridine orange, with itself, with caffeine, and with double stranded DNA

Caffeine (CAF) inhibits the intercalation of acridine orange (AO) into cellular DNA. Optical absorption and fluorescence spectroscopy were employed to determine the molecular interactions of AO with itself, with CAF, and with double stranded herring sperm DNA (dsDNA). AO dimerization was observed at concentrations >2 micromol. The sharp increase in fluorescence (lambda(em)=530 nm) at 5 micromol of AO was attributed to AO multimer formation. From 0.5 to 5.0 micromol, the AO self-association binding constant (K(assoc)) was determined to be 38620 mol(-1), however, the presence of 150 mmol NaCl increased K(assoc) to 118000 mol(-1) attributed to the charge neutralization. The K(assoc) for AO with CAF was confirmed to be 256 mol(-1). K(assoc) for the binding of AO with 20 micromol DNA ranged from, 32000 mol(-1) at 2 micromol AO, to approximately 3700 mol(-1) at 10 micromol AO, in the absence of NaCl. This AO concentration dependency of K(assoc) value with DNA was attributed to AO intercalation into dsDNA at high dsDNA/AO ratios, and electrostatic binding of AO to dsDNA at low AO ratios. The findings provide information used to explain fluorescence intensity values at lambda(em) at 530 nm from studies that combine AO, caffeine, and dsDNA.     

Interaction of tRNA with Safranal,Crocetin, and Dimethylcrocetin

Abstract

Saffron is the red dried stigmas of Crocus sativus L. flowers and used both as a spice and as a drug in traditional therapeutic. The biological activity of saffron in modern medicine is in development. Its numerous applications as an anti-oxidant and anti-cancer agent are due to its secondary metabolites and their derivatives (safranal, crocins, crocetin, dimethylcrocetin). The aim of this study was to examine the interaction of transfer RNA with safranal, crocetin, and dimethylcrocetin in aqueous solution at physiological conditions. Constant tRNA concentration (6.25 mM) and various drug/tRNA (phosphate) molar ratios of 1/48 to 1/8 were used. FT-IR and UV-Visible difference spectroscopic methods have been applied to determine the drug binding mode, the binding constants and the effects of drug complexation on the stability and conformation of tRNA duplex. External binding mode was observed for safranal crocetin and dimethylcrocetin, with overall binding constants K_safranal = 6.8 (± 0.34) × 10³ M^?1, K_CRT = 1.4 (± 0.31) × 10⁴ M^?1, and K_DMCRT = 3.4 (± 0.30) × 10⁴ M^?1. Transfer RNA remains in the A-family structure, upon safranal, crocetin and dimethylcrocetin complexation.     

Kymographs,stimulators, and kymographs with stimulators

This biology investigation on Pristipomoides filamentosus larval development, survival, and aquaculture research was developed with three educational objectives: to provide high school students with (1) a scientific background on the biology and science of fisheries as well as overfishing, its consequences, and possible mitigations; (2) exposure to field and laboratory techniques in marine science; and (3) practical skills in scientific inquiry and investigation. We teach this investigation at the Hawai‘i Institute of Marine Biology, where we have access to captive broodstock of the pink snapper, P. filamentosus. During this investigation students follow several steps scientists take to study aquaculture: collecting spawn from outdoor fish pens, quantifying the number of eggs, determining the percentage of fertilisation, and estimating the time of spawning and hatching. Additionally, students perform hypothesis-driven science activities with the embryos to test the effects of water quality on their development and survival. In this paper we discuss background information of aquaculture, specifically of P. filamentosus, and thoroughly describe the several components of delivering the investigation. Lastly, we provide possible outcomes of students’ performances in the laboratory activities, and discuss how effectively the exercise met its educational objectives.     

Linkage relations of JK, CO, KEL and IGK with each other and with AHCY

Linkage analyses of locus pairs involving IGK, JK, CO, KEL and AHCY resulted in altogether negative lod scores, thereby dwindling the reported linkage relations.     

Carbonic anhydrase inhibitors. Inhibition of isozymes I, II, IV, V, and IX with anions isosteric and isoelectronic with sulfate, nitrate, and carbonate

The inhibition of five human carbonic anhydrase (hCA, EC 4.2.1.1) isozymes; the cytosolic hCA I and II, the membrane-bound hCA IV, the mitochondrial hCA V, and the tumor-associated, transmembrane hCA IX, with anions isosteric and isoelectronic with sulfate, nitrate, and carbonate; such as chlorate, perchlorate, bromate, iodate, periodate, silicate, bismuthate, vanadate, molybdate, and wolframate is reported. Apparently, the geometry of the inhibitor (tetrahedral or trigonal) does not influence its binding to the Zn(II) ion of the enzyme active site, but the nature of the central element is the most important factor influencing potency. Isozymes hCA I and II are best inhibited by chlorate, perchlorate, and silicate, together with the anions structurally related to sulfate, sulfamate, and sulfamidate, but sulfate itself is a weak inhibitor (inhibition constant of 74 mM against hCA I and 183 mM against hCA II). Molybdate is a very weak hCA I inhibitor (K(I) of 914 mM) but it interacts with hCA II (K(I) of 27.5mM). Isozyme IV is well inhibited by sulfate (K(I) of 9 mM), sulfamate, and sulfamidate (in the low micromolar range), but not by perchlorate (K(I) of 767 mM). The mitochondrial isozyme V has the lowest affinity for sulfate (K(I) of 680 mM) and carbonate (K(I) of 95 mM) among all the investigated isozymes, suggesting on one hand its possible participation in metabolon(s) with sulfate anion exchanger(s), and on the other hand an evolutionary adaptation to working at higher pH values (around 8.5 in mitochondria) where rather high amounts of carbonate in equilibrium with bicarbonate may be present. Metasilicate, isosteric to carbonate, is also about a 10 times weaker inhibitor of this isozyme as compared to other CAs investigated here (K(I) of 28.2 mM). Surprisingly, the tumor-associated isozyme IX is resistant to sulfate inhibition (K(I) of 154 mM) but has affinity in the low micromolar range for carbonate, sulfamate, and sulfamidate (K(I) in the range of 8.6-9.6 microM). This constitutes another proof that this isozyme best works at acidic pH values present in tumors, being inhibited substantially at higher pH values when more carbonate may be present. Bromate and chlorate are quite weak CA IX inhibitors (K(I) s of 147-274 mM).     

A pheromonotropic peptide of Helicoverpa zea,with melanizing activity,interaction with PBAN,and distribution of immunoreactivity

The sequence of an 18-amino acid residue peptide was deduced from the gene encoding PBAN and other peptides with common C-termini in Helicoverpa zea. The peptide caused melanization in larvae and pheromone production in females of H. zea, and was designated pheromonotropic melanizing peptide (Hez-PMP). The peptide has a 83% sequence homology with a pheromonotropic peptide isolated from Pseudaletia separata. PMP caused melanization and mortality when injected into larvae just before molting. Whereas intense melanization was caused with a dose of 1,000 pmol, peak mortality occurred at 100 pmol, with 50% of larvae dying within 48 h after injection. Pheromonotropic activity of PMP was dose dependent. Co-injection of Hez-PMP and Hez-PBAN into a female resulted in suppression of the pheromonotropic effect of PBAN. Whole-mount immunocytochemical studies revealed PMP-like immunoreactivity in frontal ganglion, subesophageal, thoracic, and abdominal ganglia as well as the esophageal nerve.     

Interaction of tRNA with Safranal, Crocetin, and Dimethylcrocetin

Saffron is the red dried stigmas of Crocus sativus L. flowers and used both as a spice and as a drug in traditional therapeutic. The biological activity of saffron in modern medicine is in development. Its numerous applications as an anti-oxidant and anti-cancer agent are due to its secondary metabolites and their derivatives (safranal, crocins, crocetin, dimethylcrocetin). The aim of this study was to examine the interaction of transfer RNA with safranal, crocetin, and dimethylcrocetin in aqueous solution at physiological conditions. Constant tRNA concentration (6.25 mM) and various drug/tRNA (phosphate) molar ratios of 1/48 to 1/8 were used. FT-IR and UV-Visible difference spectroscopic methods have been applied to determine the drug binding mode, the binding constants and the effects of drug complexation on the stability and conformation of tRNA duplex. External binding mode was observed for safranal crocetin and dimethylcrocetin, with overall binding constants K(safranal) = 6.8 (+/- 0.34) x 10(3) M(-1), K(CRT) = 1.4 (+/- 0.31) x 10(4) M(-1), and K(DMCRT) = 3.4 (+/- 0.30) x 10(4) M(-1). Transfer RNA remains in the A-family structure, upon safranal, crocetin and dimethylcrocetin complexation.     

Titin-cap associates with,and regulates secretion of,Myostatin

Myostatin, a secreted growth factor, is a key negative regulator of skeletal muscle growth. To identify modifiers of Myostatin function, we screened for Myostatin interacting proteins. Using a yeast two-hybrid screen, we identified Titin-cap (T-cap) protein as interacting with Myostatin. T-cap is a sarcomeric protein that binds to the N-terminal domain of Titin and is a substrate of the titin kinase. Mammalian two-hybrid studies, in vitro binding assays and protein truncations in the yeast two-hybrid system verified the specific interaction between processed mature Myostatin and full-length T-cap. Analysis of protein-protein interaction using surface plasmon resonance (Biacore, Uppsala, Sweden) kinetics revealed a high affinity between Myostatin and T-cap with a KD of 40 nM. When T-cap was stably overexpressed in C(2)C(12) myoblasts, the rate of cell proliferation was significantly increased. Western analyses showed that production and processing of Myostatin were not altered in cells overexpressing T-cap, but an increase in the retention of mature Myostatin indicated that T-cap may block Myostatin secretion. Bioassay for Myostatin confirmed that conditioned media from myoblasts overexpressing T-cap contained lower levels of Myostatin. Given that Myostatin negatively regulates myoblast proliferation, the increase in proliferation observed in myoblasts overexpressing T-cap could thus be due to reduced Myostatin secretion. These results suggest that T-cap, by interacting with Myostatin, controls Myostatin secretion in myogenic precursor cells without affecting the processing step of precursor Myostatin.