中国美利奴（新疆型）新品系羊综合选择指数制定指数制定及应用效果分析

本研究分别对中国美利奴羊（新疆型）体格大品系和毛质好品系制定出综合选择指数I1=1.97x1 3.32x2(x1为体重，x2为毛量）和I2=2.2x1 0.67x2(x1为弯曲评分，x2为毛量），使用效果表明，两个选择指数实用性较为理想。     

125I粒子植入治疗胃癌有效性与安全性评价

目的 探讨125I粒子组织间植人治疗胃癌的有效性及该方法能否提高患者生存率.方法 选取同时期Ⅱ、Ⅲ期胃癌患者76例,按单纯随机分为根治性手术组(34例,仅行根治性手术,D2、D3术式)和根治性手术+125I粒子组(42例,行根治性手术+125I粒子治疗).治疗效果分CR(治疗后肿瘤完全消失达1个月以上)、PR(肿瘤较治疗前缩小50％以上至少1个月)、NC和PD,CR+PR为治疗有效,据此计算有效率.随访并计算患者生存率及并发症发生情况.率的比较采用x2检验.结果 根治性手术组总有效率50.00％ (17/34),根治性手术+125I粒子组总有效率为73.81％(31/42),2组差异有统计学意义(x2=4.578,P＜0.05).根治性手术+1251粒子组3年和5年生存率分别为61.90％(26/42)和42.86％ (18/42),均高于根治性手术组[11.76(4/34)和0(0/34)；x2=19.771和19.094,均P＜0.001].2组毒性和不良反应均较少.结论 根治性手术+125I粒子植入治疗Ⅱ、Ⅲ期胃癌较单纯根治性手术更有效,能进一步提高远期生存率,不良反应少.     

131I与131I联合保肝药物治疗Graves甲亢合并肝损害的疗效比较

目的 比较131I及131I联合保肝药物治疗Graves甲状腺功能亢进症(简称甲亢)合并肝损害的效果.方法 采用随机区组设计将120例Graves甲亢合并肝损害患者分为2组:治疗组60例,应用131I+还原型谷胱甘肽片治疗;对照组60例,应用131I治疗.所有患者采用个体化剂量口服131I治疗,并于131I治疗后1、3和6个月复查FT3、FT4、TSH、ALT、AST及总胆红素(TBIL),观察患者Graves甲亢及肝功能恢复情况.采用电化学发光法测定血清FT3、FT4、TSH水平;采用速率法检测血清ALT、AST水平,重氮盐法检测血清TBIL水平.计算并比较2种方法治疗的治愈率和有效率.数据比较采用t检验和x2检验.结果 2组患者131 I治疗后1、3和6个月甲状腺激素水平较治疗前差异均有统计学意义.治疗后2组甲状腺激素水平分别为:治疗组FT3≤(17.13±5.22)pmol/L、FT4≤(51.26±20.60)pmol/L、TSH≥(0.11±0.09) mU/L;对照组相应指标水平为≤(17.41±5.18) pmol/L、≤(50.60±20.45) pmol/L、≥(0.12±0.09) mU/L(t=5.1843～14.8564,P均＜0.01),而组间相比差异均无统计学意义(t=0.1478 ～0.3902,P均＞0.05).治疗组服131I后1、3、6个月肝功能指标(ALT、AST和TBIL)明显降低,与治疗前差异均有统计学意义(t=6.4080～13.8795,P均＜0.01).对照组服131I后1个月患者肝功能指标开始降低,但与治疗前差异均无统计学意义(t=1.3262～1.9700,P均＞0.05);3个月和6个月肝功能指标明显降低,与治疗前差异均有统计学意义(t =6.0144～10.5171,P均＜0.01).131I治疗后6个月治疗组与对照组Graves甲亢的治愈率分别80.0％( 48/60)和78.3％ (47/60),有效率为98.3％( 59/60)和95.0％( 57/60),2组相比差异均无统计学意义(x2=0.0505和1.0344,P均＞0.05);2组患者肝损害恢复正常率分别为88.3％( 53/60)和65.0％( 39/60),有效率为96.7％( 58/60)和88.3％ (50/60),差异均有统计学意义(x2=9.1304和8.1067,P均＜0.05).结论 131I治疗Graves甲亢合并肝损害疗效良好,联合应用保肝药物可促进患者肝功能的恢复.     

负压封闭引流干预创伤后应激代谢的实验研究

目的探讨负压封闭引流(VSD)技术对兔骨骼肌缺血再灌注损伤(I/R)后应激代谢的影响。方法 30只雄性新西兰实验兔随机分成假手术组、I/R组和I/R+VSD组3组,每组10只建模。(1)假手术组动物仅完成左后肢股动静脉组织游离,为假手术对照;(2) I/R组动物完成组织游离后进行左后肢股动静脉的夹闭(6h)及开放(6h),不进行VSD干预;(3) I/R+VSD组动物在进行再灌注的同时对损伤处予以VSD干预(-70kPa,6h)。观察各组己糖激酶2(HK2)、磷酸果糖激酶1(PFK1)、丙酮酸激酶M1(PKM1)、乳酸盐脱氢酶A(LDHA)和丙酮酸脱氢酶激酶4(PDK4),以及组织内丙酮酸(PA)和乳酸(LA)、外周血p H值和阴离子间隙(AG)值的变化,所得数据采用方差分析统计。结果 (1)糖酵解关键酶:在实验结束后测得假手术组HK2:(11. 153±1. 279) pg/g、PKF1:(20. 356±3. 478) pg/g、PKM1:(33. 349±5. 413) pg/g,I/R组HK2:(27. 863±3. 976) pg/g、PKF1:(50. 504±8. 598) pg/g,PKM1:(64. 423±11. 915) pg/g,I/R+VSD组HK2:(19. 202±3. 107) pg/g、PKF1:(39. 135±4. 921) pg/g,PKM1:(46. 768±5. 774) pg/g;其中I/R+VSD组HK2、PKF1、PKM1三项指标均显著性升高(P=0. 030、P=0. 040和P=0. 047)。(2)糖酵解相关酶:再灌注前I/R组LDHA相对值:25. 492±4. 441,PDK4相对值:20. 613±4. 753,I/R+VSD组LDHA相对值:24. 388±4. 663,PDK4相对值:28. 177±5. 283;实验结束后I/R组LDHA相对值:17. 440±3. 263,PDK4相对值:15. 438±4. 125,I/R+VSD组LDHA相对值:16. 998±3. 528,PDK4相对值:22. 492±6. 552,其中I/R+VSD组LDHA及PDK4的表达显著性升高(P=0. 031和P=0. 025)。(3)酸中毒指标:3组在实验结束后的假手术组PA:(0. 259±0. 044) mmol/L、LA:(2. 351±0. 303) mmol/L、LA/PA:9. 077±0. 689,I/R组PA:(0. 382±0. 033) mmol/L、LA:(5. 688±1. 153) mmol/L、LA/PA:4. 890±1. 349,I/R+VSD组PA:(0. 365±0. 047) mmol/L、LA:(4. 285±0. 937) mmol/L、LA/PA:11. 740±1. 001,其中I/R+VSD组LA和LA/PA比值在实验结束后均显著性降低(P=0. 023和P=0. 018)。结论 VSD技术可上调糖酵解酶的表达,改善应激状态时细胞的能量代谢,通过减少局部酸中毒和p H反常的发生,对机体起到了保护作用。     

1-6岁天山马鹿体重体尺与产茸量的多元回归分析

对北疆1-6岁共60头天山马鹿的体重(x1),体长(x2),胸围(x3)和管围(x4)与产茸量(y)采用相关分析及多元回归分析,建立了产茸量的估测模型y^ = 1070.24 +22.82x1-32.89x3 ,经检验此模型的适合度、回归系数和复相关系数均差异极显著(P<0.01).模型预测效果良好,为天山马鹿的选育提供了科学的参考依据.     

^131I治疗Graves病疗效影响因素的交互作用

目的分析影响^131I治疗Graves病疗效的多种因素问可能存在的交互作用,以期更全面、准确评估患者预后,指导临床治疗。方法收集632例Graves病行^131I治疗患者的临床资料及辅助检查结果,采用单因素（t检验、x2检验）及多因素（logistic回归）分析确定^131I疗效的影响因素：x2为年龄,x2为性别,x3为甲状腺质量,x4为病程,x5为发病情况,x6为病情,x7为抗甲状腺药物（ATD）疗程,x8为有效半衰期,x9为最高吸^131I率,x10为患者服^131I总剂量,x11为每克甲状腺组织给予^131I的平均剂量,x12为TRAb水平,x13为TSI水平,x14为TgAb,x15,为甲状腺微粒体抗体（TMAb）。y为疗效。然后进一步分析（对数及一般线性模型）各影响因素间的交互作用。结果单因素及多因素分析结果显示年龄（x1）、甲状腺质量（x3）、ATD疗程（x7）、最高吸^131I率（x9）、每克甲状腺组织给予^131I的平均剂量（x11）及TSI（x13）等因素影响^131I疗效（r=6．908,t=-4063, x2=13．558,t=-2．553,t=4．528,x2=9．716,P均〈0．05）。对数线性模型及一般线性模型分析结果显示年龄（x1）、甲状腺质量（x3）、ATD疗程（x7）、最高吸^131I率（x0）等因素间存在着多重正相乘和正相加交互作用（似然比x2=8．176,P〉0．05;F=2．928,1．992,2．629,2．215,P均〈0．05）,导致多因素共存时对^131I疗效的影响并非单因素作用的简单累加。结论多种因素间存在的交互作用会对^131I疗效造成间接的影响,这对患者实际服^131I剂量作适当调整有指导作用。     

500例Graves病患者131I治疗后3年随访分析

目的 分析500例Graves病患者131I治疗后3年内不同时期甲状腺功能亢进症(简称甲亢)缓解率和甲状腺功能减退症(简称甲减)发生率,探讨早发甲减的发展规律以及影响131I治疗的因素.方法 500例131I治疗后3年的Graves病患者,平均年龄(39.3±12.6)岁,男女比例1∶5.收集每例患者资料,包括症状、体征、实验室检查、24h摄碘率、有效半衰期、131I剂量,治疗后3、6、9个月以及1、2、3年的甲亢缓解和甲减发生例数,并观察早发甲减者的甲状腺功能变化.用SPSS 15.0软件对数据行t检验、x2检验及多因素logistic逐步回归分析.结果 131I治疗后3个月甲亢缓解率63.8％(319/500),甲减发生率36.6％(183/500);6个月甲亢缓解率67.8％(339/500),甲减发生率43.4％(217/500);9个月甲亢缓解率70.0％(350/500),甲减发生率39.4％(197/500);1年甲亢缓解率72.6％(363/500),甲减发生率38.2％(191/500);2年甲亢缓解率79.6％(398/500),甲减发生率40.8％(204/500);3年甲亢缓解率90.8％(454/500),甲减发生率46.0％(230/500).84例(16.8％)首次治疗后疗效不佳,进行了第2次治疗.260例初次治疗后发生早发甲减,治疗后3年其中70例(26.9％)甲状腺功能恢复正常,178例(68.5％)持续甲减,12例(4.6％)甲亢复发.单次131I治疗后3年甲状腺功能正常192例,甲减200例,此392例为成功组,84例2次治疗者为失败组.对成功组与失败组数据进行单因素分析,筛选出ATD治疗(x2=16.758,P＜0.01)、TRAb(t=-2.074,P=0.039)、甲状腺摄碘率(t=-2.229,P=0.026)、有效半衰期(t=3.827,P＜0.01)、SPECT测定的甲状腺质量(t=-3.153,P =0.002)、每克甲状腺组织计划剂量(t=-2.154,P =0.032)和实际剂量(t=-1.985,P=0.048)为影响131I治疗的有关因素.将这些有关因素进行logistic逐步回归分析,得ATD治疗(Wald=14.227,P＜0.01)和有效半衰期(Wald=4.497,P=0.034)是影响131I成功治疗的因素.结论 131I治疗Graves病后3年,甲亢缓解率高,但甲减发生率也高.大部分早发甲减患者仍持续甲减,少数甲状腺功能恢复正常或甲亢复发.ATD治疗和有效半衰期是影响131I成功治疗的重要因素.     

125I粒子平面布源剂量学研究

Objective To study the dosimetry of different arrangements of 125I seeds in one plane.Methods Nine different in-plane arrangements of 9 125I seeds (2.035 × 107 Bq/seed) were simulated according to distance (cm) along x (horizontal)- and y( longitudinal )-axis using the 3-dimensional treatment planning system (TPS) (3D-TPS): x0.5, y0. 5; x0. 5, y1.0; x0. 5, y1.5; x1.0, y1.0; x1.0, y1.5;x1.5, y1.5; x0. 5, y0. 5 (2)1.0; x0.5, y1.0 (2)0.5; x1.0, y1.0 (2)0.5. The isodose curves of 40,80, 130, 145 and 200 Gy were created and the area, radius and medical cost under the 40, 80, 130, 145and 200 Gy isodose curves were calculated. Results The area, radius and medical cost under the same isodose curves were significantly different with each 125I seed arrangement. The arrangements which had the biggest area under curves of 40, 80, 130, 145 and 200 Gy isodose were x1. 5, y1. 5; x1. 0, y1. 0; x1. 0,y1. 0; x0. 5, y1. 0 and x0. 5, y1. 0, respectively. Conclusion The matched peripheral dose and therapeutic effect were affected significantly by the geometric arrangement of 125I seeds.     

应用电子计算机确定饲料喂量和饲养标准(二)

三、按体重计算养分需要量 根据日本饲养标准,生长牛和成年牛的养分需要量一般是以体重间隔50公斤为一等级来表示。 (一)成年母牛维持体重的 养分需要量的计算 1.乳用成年母牛 设体重为x公斤,DCP需要量为y克,日本乳牛饲养标准的数值可用式(6)说明;设TDN需要量为z公斤,可用式(7)说明。 y=90+0.4x(6) z=1+0.006x(7) 因相关系数r都取1,故饲养标准的数值也可用上式计算。     

中低危分化型甲状腺癌术后131I清甲治疗后血清甲状腺球蛋白的变化

目的 探讨患中低危DTC初次131I治疗后6个月复查131I全身显像(WBS)示阴性、刺激性Tg阳性(≥10.00 μg/L)患者Tg的转归情况.方法 回顾性分析56例按美国甲状腺学会(ATA)指南诊断其复发危险分层为中低危的DTC患者[男20例,女36例,平均年龄43.11(21～70)岁],患者均经甲状腺全切除术+131I清除残余甲状腺组织+甲状腺激素抑制治疗,均于131I治疗后6个月停用甲状腺激素,复查131I WBS均为阴性.此时刺激性Tg≥10.00 μg/L即为刺激性Tg阳性.56例中,刺激性Tg阳性组19例,阴性组37例,追踪2组131I治疗后1年及2.5年抑制性Tg变化,同时监测颈部超声表现等变化.采用SPSS 17.0软件对数据进行两样本t检验和x2检验.结果 刺激性Tg阳性组131I治疗后6个月血清刺激性Tg明显高于阴性组,分别为(24.27±4.10)与(2.73±3.01)μg/L(t=7.191,P＜0.05);阳性组中68.4％ (13/19)的患者血清抑制性Tg水平随时间呈逐渐下降趋势,131I治疗后2.5年时为(0.53±0.15) μg/L,比治疗后1年时的(1.38±0.50) μg/L低;阳性组131I治疗后1年时抑制性Tg仍高于阴性组[(2.21±0.55)与(0.48±0.10) μg/L;t=3.102,P＜0.05],至2.5年时,2组差异无统计学意义[(1.44±0.52)与(0.38±0.07) μg,/L;t=2.001,P＞O.05].2组各有l例患者治疗后2年时随访颈部超声发现肿大淋巴结(抑制性Tg分别为1.4和0.1 μg/L),经术后病理证实为淋巴结转移性甲状腺癌.结论 131I治疗后6个月刺激性Tg阳性的中低危DTC患者血清Tg水平随时间呈下降趋势,此时停用甲状腺激素行131I WBS的意义及经验性131I治疗的价值有待进一步探讨.     

Measurement of effective renal plasma flow: a comparison of methods

We have compared two in vitro methods and three variations of kidney background (BG) subtraction within a gamma camera method (41 examinations, 31 patients) for determination of effective renal plasma flow (ERPF) using 131I orthoiodohippurate (OIH). Method I: plasma samples at 20 and 45 min after OIH injection, ERPF = dose X slope/intercept; Method II: 45-min plasma sample, ERPF = -51.1 + 8.21x + 0.019x2, x = dose/45-min plasma activity/I. Individual kidney and total ERPF were determined from gamma camera (GC) methods using renal uptake 1-2 min after injection. All methods were compared against Method I (previously validated against paraaminohippurate (PAH) clearances). Method II, which requires one blood sample is more accurate than GC methods. GC methods are insensitive to operator variability in placement of renal and BG regions of interest. They may be useful to follow changes in relative or total ERPF, but accurate depth correction of renal data is suggested. In vitro, blood sample-based methods are more accurate.     

Reflective inserts to reduce heat strain in body armor: tests with and without irradiance

BACKGROUND: This study evaluated adding reflective thermal inserts (RTI) to reduce the physiological strain during exercise-heat stress with a radiant load. RTI were used with a U.S. Army desert battle dress uniform, body armor, and helmet. METHODS: Four male volunteers attempted four trials (10 min rest followed by 100 min walking at 1.56 m x s(-1)). All trials were at 40.0 degrees C dry bulb (Tdb), 12.4 degrees C dew point (Tdp), 20% RH, and 1.0 m x s(-1) wind speed. On 2 d, there was supplementary irradiance (+1) with globe temperature (Tbg) = 56.5 degrees C and on 2 d there was no supplementary irradiance (-I) with Tbg approximately Tdb. Trial conditions were: 1) RTI and armor with supplementary irradiance (RA+I); 2) plain armor with supplementary irradiance (PA+I); 3) RTI and armor with no supplementary irradiance (RA-I); and 4) plain armor with no supplementary irradiance (PA-I). RESULTS: Endurance times were not significantly different among trials. With one exception, armor and helmet interior and exterior surface temperatures were not significantly different between either RA+I and PA+I or RA-I and PA-I. Temperature on the inside of the helmet in RA+I (47.1 +/- 1.4 degrees C) was significantly lower than in PA+I (49.5 +/- 2.6 degrees C). There were no differences for any physiological measure (core temperature, heart rate, mean weighted skin temperature, forehead skin temperature, sweating rate, evaporative cooling, rate of heat storage) between either RA+I and PA+L or RA-I and PA-I. CONCLUSIONS: Results showed no evidence that wearing RTI with body armor and helmet reduces physiological strain during exercise-heat stress with either high or low irradiance.     

131I治疗分化型甲状腺癌术后患者疗效影响因素研究

目的 探讨影响分化型甲状腺癌（DTC）患者术后首次131I清除残留甲状腺组织（简称清甲）疗效和多次131I治疗转移灶（清灶）疗效的因素。方法回顾性分析首次接受大剂量清甲治疗的患者46例（分为成功组与未成功组）资料、多次清灶治疗的患者40例（分为临床缓解组和未缓解组）资料,对数据进行t检验、t’检验、X^2检验或Fisher确切概率法筛选影响因素,并做Logistic回归分析。结果用单因素分析筛选出手术方式、残余甲状腺质量、促甲状腺激素（TSH）水平、手术至清甲治疗时间和存在转移灶是影响清甲效果的因素（X2=5．804、t’=-5．258、t=7．376、X^2=8．867、X2=8．615,P均〈0．05）。Logistic回归分析得到的清甲成功的拟合方程为Y=3．766—0．947x,（残余甲状腺质量）-3．149x：（淋巴结转移）-3．373x,（远处转移）。对临床缓解率行单因素分析显示：甲状腺乳头状癌显著高于甲状腺滤泡状癌,仅有淋巴转移灶显著高于有远处转移灶,甲状腺全切显著高于其他手术方式（Fisher确切概率法,X。=7．278,P〈0．05）;首次131I治疗前,临床缓解组的TSH水平明显高于未缓解组,甲状腺球蛋白（Tg）水平明显低于未缓解组（t=4．489、t=-4．906,P均〈0．01）。Logistic回归分析得到清灶成功拟合方程为：Y=-0．363＋0．065x4（TSH水平）-0．250x5（Tg水平）。结论DTC患者首次清甲疗效的影响因素有手术方式、残余甲状腺质量、TSH、手术至清甲治疗时间和有无转移灶;其中残留甲状腺组织少、无淋巴结转移和无远处转移是提高成功率的关键因素。DTC患者清灶疗效的影响因素包括病理类型、手术方式、转移灶的部位、TSH和Tg;其中首次131I治疗前有较高水平的TSH和较低水平的强是提搞缓解率的关键因素。     

A study on the isolation period of patients with metastatic thyroid cancer treated by 131I according to a new guideline]

In Japan, a new guideline for the release of patients administered 131I was issued by the Ministry of Welfare on June, 1998: The dose rate is under 30 microSv/h at 1 m or the activity in the body is under 500 MBq. This study was designed to set the appropriate isolation period enough to satisfy these limits. A total of 28 patients with the history of total thyroidectomy and metastasis were selected for this study. In these patients, 28 patients were treated with oral administration of 3.7 GBq of Na131I (72 times), and one of 28 patients was once treated with 5.55 GBq of Na131I. Two of them were also received a total of 4 courses of a split dose therapy of 3.7 GBq of Na131I (740 MBq once a week for 5 consecutive weeks = one course). Measurements of the external exposure dose (microSv/h) at 1 m and the urinary excretory radioactivity (MBq) were performed at various times. There was a good correlation of the external exposure dose between standing (x microSv/h) and sitting (y microSv/h) postures (y = 0.99x + 0.406, r = 0.99, p < 0.0001, n = 169). The difference in the external exposure dose before and after urination (x microSv/h) had a significant correlation with the urinary excretory radioactivity (y MBq); y = 16.6x + 24.8, r = 0.96, p < 0.001, n = 41. Also, there was a significant correlation between the predicted value of residual radioactivity in the body (y' MBq) and the external exposure dose (x' microSv/h); y' = 20.8x' + 31.5, r = 0.98, p < 0.001, n = 77. In the patients treated with 3.7 GBq of Na131I, the mean and S.D. values of the external exposure dose (microSv/h) changed as follow: After 6 hr, 168 +/- 40; 24 hr, 52 +/- 23; 48 hr, 20 +/- 15; 72 hr, 10 +/- 9; and 96 hr, 8 +/- 9. The percentages of the patients satisfied the new guideline were as follow; 21.7% at 24 hr, 81.2% at 48 hr and 100% after 72 hr. Therefore the 3-day isolation is sufficient for the patients administered 3.7 GBq of Na131I.     

Is coronary artery calcium mass related to Agatston score?

RATIONALE AND OBJECTIVES: The objective of this study was to investigate the relationship between the coronary calcium mass and Agatston score measured on multidetector row computed tomography. MATERIALS AND METHODS: Eighty-three consecutive subjects (60 men and 23 women) referred for coronary screening were examined prospectively by electrocardiogram-triggered sequential multidetector row computed tomography scan (4 x 2.5-mm collimation). Their coronary calcium was quantitated by means of the Agatston scoring and mass method. The values of score and mass were transformed by taking the natural logarithm (ln(value + 1)) to reduce skewness. The relationship between the mass and score was analyzed with multiple regression analysis. RESULTS: Fifty-one subjects had a total of 328 calcified lesions detected and measured. The relationship between the calcium mass and score in 51 subjects conformed well to a linear relationship (r2 = 0.96). When analyzed in the total of 328 lesions, the relationship had a good empiric fit with a nonlinear (quadratic) model (r2 = 0.96). The best-fit equation was ln(lesion mass + 1) = -0.87 + 0.67 x ln(lesion score + 1) + 0.10 x (ln(lesion score + 1) - 2.86)2. This relationship was consistent in different coronary vessels and at different heart levels (r2 = 0.96 - 0.99), although there was a higher image noise at lower heart levels (paired t-tests, P < .0001). CONCLUSION: A nonlinear (quadratic) relationship existed strongly and consistently between coronary calcium mass and score, demonstrating a possible cross-sectional conversion between the two measurements.     

Measuring and predicting maximal aerobic power in international-level intermittent sport athletes

AIM: The purpose of this study was to measure actual VO2max during the multi-stage fitness test (MSFT) and to compare this with predicted values obtained using previously established, commonly used methods. We also wanted to determine a new and more accurate regression equation for the prediction of VO2max in intermittent sport athletes. METHODS: Twenty-six, elite, male, intermittent sport athletes performed the MSFT with oxygen uptake (VO2) and heart rate (HR) measured throughout. Paired t-tests were used to compare measured VO2max with predicted VO2max. Linear regression was used to determine the equation for the prediction of VO2max from the total number of shuttles completed. RESULTS: There were no differences between the two methods of predicting VO2max, however, both predicted values (53.6+/-3.9 and 51.3+/-4 mL x kg(-1) x min(-1)) were significantly lower (9.3% and 13.2%, respectively) than measured VO2max (59.1+/-6.6 mL x kg(-1) x min(-1), P < 0.001). Correlations between measured and predicted VO2max were similar for both prediction methods (r = 0.61, P = 0.013 and r = 0.68 and P = 0.004). We present a new prediction equation [Y (VO2max, mL x kg(-1) x min(-1)) = 0.38 x total number of shuttles completed +25.98] (where R = 0.69; R2 = 0.48; SEE = 4.9 mL x kg(-1) x min(-1); SEE% = 8.3) which provides a more valid method of predicting actual max in intermittent sport athletes. CONCLUSIONS: A new regression equation to predict VO2max in intermittent sport athletes has been established. Whilst some error in predicting VO2max still exists, the new equation will provide coaches and sport-scientists with a more suitable equation with which to predict VO2max in intermittent sport athletes.     

Phase- and size-adjusted CT cut-off for differentiating neoplastic lesions from normal colon in contrast-enhanced CT colonography

A computed tomography (CT) cut-off for differentiating neoplastic lesions (polyps/carcinoma) from normal colon in contrast-enhanced CT colonography (CTC) relating to the contrast phase and lesion size is determined. CT values of 64 colonic lesions (27 polyps <10 mm, 13 polyps 10 mm, 24 carcinomas) were determined by region-of-interest (ROI) measurements in 38 patients who underwent contrast-enhanced CTC. In addition, the height (H) of the colonic lesions was measured in CT. CT values were also measured in the aorta (A), superior mesenteric vein (V) and colonic wall. The contrast phase was defined by using x as a weighting factor for describing the different contrast phases ranging from the pure arterial phase (x=1) over the intermediate phases (x=0.9–0.1) to the pure venous phase (x=0). The CT values of the lesions were correlated with their height (H), the different phases ( ) and the ratio . The CT cut-off was linearly adjusted to the imaged contrast phase and height of the lesion by the line . The slope m was determined by linear regression in the correlation ( ) and the Y-intercept y₀ by the minimal shift of the line needed to maximize the accuracy of separating the colonic wall from the lesions. The CT value of the lesions correlated best with the intermediate phase: 0.4A + 0.6V (r=0.8 for polyps 10 mm, r=0.6 for carcinomas, r=0.4 for polyps <10 mm). The accuracy in the differentiation between lesions and normal colonic wall increased with the height implemented as divisor, reached 91% and was obtained by the dynamic cut-off described by the formula: . The CT value of colonic polyps or carcinomas can be increased extrinsically by scanning in the phase in which 0.4A + 0.6V reaches its maximum. Differentiating lesions from normal colon based on CT values is possible in contrast-enhanced CTC and improves when the cut-off is adjusted (normalized) to the contrast phase and lesion size.     

Compartmentation of intracellular water in multicellular tumor spheroids: diffusion and relaxation NMR.

Diffusion and relaxation of water in C6 glioma and MLS human ovarian carcinoma spheroids were measured from 1D projections acquired using a 2D diffusion-relaxation correlation pulse sequence and processed by non-negative least-square (NNLS) analysis. Systematic underestimation of I(s) and ADC(s) were observed for I(s)/(I(s) + I(f)) < 0.001. In the presence of spheroids, two apparent diffusion coefficient (ADC) compartments were observed, where ADC(f), ADC(s), and I(f), I(s) are the respective ADCs and signal intensities of the fast and slow compartments. These compartments differed also in their T(2) relaxation (ADC(s) = 0.5-0.74 x 10(-5) cm(2)/s, T(2) = 36-45 ms; and ADC(f) = 2.2-2.8 x 10(-5) cm(2)/s, T(2) = 280-316 ms). The two ADC compartments and the slow T(2) compartment were consistent with slow exchange. The fast T(2) compartment showed a drift with diffusion weighting, suggesting that it represents water exchanging between compartments that differ in their ADC and T(2). Both ADC(s) and I(s) were markedly attenuated with increasing diffusion time (Delta) for Delta < 100 ms, and increased at longer Delta. These results are consistent with restricted diffusion and fast relaxation of intracellular water for short diffusion time (T(1)' = 46.6 ms), and with predominant extracellular contribution to ADC(s) at longer diffusion times. Magn Reson Med 46:68-77, 2001.     

Report on the ECR2003 (European Congress of Radiology): comparison of apparent diffusion coefficient (ADC) between different MRI scanners

PURPOSE: To analyze reproducibility of ADC measurements on different MRI scanners. METHODS AND MATERIALS: Diffusion-weighted imaging (DWI) of a home-made phantom (gelatine of different concentration was enclosed in case of circle pillar shape) was performed with the following protocol; spin-echo type echo planar imaging; TR=7000 msec, TE=minimal, matrix=128 x 128, FOV=220 mm, slice thickness=5mm, NEX=1, b-factor=0, 500, and 1000 sec/mm(2) on four different 1.5T MR scanners [GE Signa Horizon (two of them), GE Signa Horizon Lx, and Siemens Magnetom Symphony]. Image analysis were performed on a workstation (GE Medical Systems) or on an operators console of Symphony (for data of Symphony). We used two-point method. Regions of interest (ROIs) were set on every part of ADC map of home-made phantom and ADCs were measured. A linear approximation graphs were also made with every MRI scanner and b-factor. RESULTS: A linear approximation was performed, formulas were y=-0.08x+2.32, r(2)=0.84(Lx), y=-0.09x+2.58, r(2)=0.89(Horizon-1) y=-0.11x+2.67, r(2)=0.95(Horizon-2), y=-0.08x+2.42, r(2)=0.97(Symphony) at b-factor of 500sec/mm(2). y=-0.08x+2.33, r(2)=0.91(Lx), y=-0.09x+2.43, r(2)=0.93(Horizon-1), y=-0.08x +2.48, r(2)=0.92(Horizon-2), y=-0.07x+2.39, r(2)=0.96(Symphony) at b-factor of 1000 sec/mm(2). CONCLUSIONS: ADC values measured at two MRI scanners (same model and older than the other scanners) are higher than other scanners on b-factor=500 sec/mm(2), but at b-factor=1000 sec/mm(2), a good relationship between every scanners was obtained. This result seems to depend on generation of the MRI scanners; newly scanners have good relations b-factor 500 and 1000 sec/mm(2). Pulse sequence design may be improved and optimized in newly scanners. When ADCs were used as quantitative value, a proper b-factor must be used.