Adaptations in skeletal muscle capillarity following changes in oxygen supply and changes in oxygen demands

Summary The effects of changes in oxygen supply and oxygen demands on fiber cross-sectional areas, capillary dersities and capillary to fiber ratios were determined in three skeletal muscles of rat. The muscles examined were the vastus lateralis, soleus, and diaphragm. Reduced oxygen supply was produced by subjecting rats to ambient hypoxia, and increased oxygen demands were produced by subjecting rats to low ambient temperatures or treatment with thyroxin. Capillaries were visualized by injecting fluorescent dyes into the circulation. Muscles were quick frozen at resting lengths to preserve normal fiber geometry and were subsequently sectioned on a cryostat. All of the muscles sampled from animals in the experimental groups had elevated capillary densities. However, capillary to fiber ratios were not increased significantly in any muscle, for any experimental condition. Thus, all of the observed differences in capillarity were due to changes in the intrinsic rate of muscle fiber growth. Further, the relations of capillary density and capillary to fiber ratio to fiber area were the same as those obtained during normal maturation, suggesting that capillary growth is closely linked to the intrinsic rate of fiber growth.     

甲心安煎剂对甲状腺素性心脏肥大大鼠心肌胶原含量的影响

目的 探讨甲心安煎剂治疗甲状腺素性心脏肥大的机制。方法将清洁级SD大鼠40只分为4组，即正常组、模型组、甲心安高剂量和低剂量治疗组各10只。正常组与模型组每日灌服纯化水2 mL，高剂量组每日灌服甲心安原液(含生药4 g·mL^-1)，低剂量组灌服甲心安稀释液(将原液加纯化水稀释至含生药2 g·mL^-1)，连续给药10 d。实验第11天取标本检测指标。结果模型组左心室重量及与体重之比均高于正常组(P＜0.01)，心肌胶原含量及 Ⅰ/Ⅲ 胶原比例均较正常组高(P＜0.01)。与之相反，经过甲心安煎剂干预后，治疗组无论低剂量或高剂量，其上述指标均较模型组低(P＜0.01)。结论甲心安煎剂能改善甲状腺素引起的心肌肥厚，降低重构心肌中的胶原含量，并调整优化心肌中 Ⅰ/Ⅲ 胶原比例。     

糖尿病阴虚证动物模型的复制

目的：复制一种症状、体征比较理想,可操作性强,重复性好的阴虚证糖尿病动物模型。方法：采用Wistar大鼠连续皮下注射甲状腺素7d后,再空腹腹腔一次性注射50mg／kg链脲佐菌素的方法,复制阴虚证1型糖尿病模型。结果：模型复制48h后大鼠空腹血糖均大于11．1mmol／L,连续观察3周,血糖值始终大于11．1mmol／L,波动较小,未见转复。大鼠三多一少（多食、多饮、多尿,体质量下降）症状明显,同时大鼠出现烦躁、活动频繁而动作无力、发育迟缓、被毛暗淡无光泽、尿色加深、大便色黑干硬、体温升高等阴虚症状。尿糖、尿蛋白均增高,肝功能、肾功能均有不同程度的损害。结论：甲状腺素联合链脲佐菌素注射复制的阴虚证糖尿病大鼠模型,符合临床诊断标准,可广泛用于糖尿病阴虚证各个领域的研究。     

碘缺乏对BALB/c小鼠促甲状腺激素β剪接变体基因表达的影响

目的 制备碘缺乏小鼠模型,检测促甲状腺激素(TSH)β剪接变体(TSHβ-Ⅴ)是否受循环中甲状腺激素的调节,探讨免疫系统来源的TSHβ-Ⅴ在维持甲状腺自稳态中的作用.方法 选用离乳BALB/c小鼠20只,雌雄各半.小鼠按体质量和性别随机分为2组,每组10只.对照组:饮去离子水,普通饲料喂养;低碘组:饮去离子水,低碘饲料(含碘量20 - 40μg /kg)喂养,每日碘摄入量约为0.25μg/d.3个月后处死小鼠,化学发光免疫分析法(CIA)检测小鼠血清中甲状腺激素和TSH水平,实时定量(RT)-PCR法测定小鼠骨髓、外周血、甲状腺、垂体TSHβ-Ⅴ的表达.结果 低碘组小鼠血清总甲状腺素(TT4)、游离甲状腺素(FT4)、总三碘甲腺原氨酸(TT3)、游离三碘甲腺原氨酸(FT3)[ (0.47±0.70)nmol/L、(2.41±0.28)pmol/L、(0.76±0.08 )nmol/L、(4.01±0.40) pmol/L]显著低于对照组[(55.2±3.68)nmol/L、(32.72±1.02) pmol/L、(1.10±0.06)nmol/L、(5.40±0.38 )pmol/L,t=43.81、86.04、9.81、7.51,P均＜0.01];低碘组小鼠TSH[(35.67±17.39)mU/L]明显高于对照组[(0.24±0.10)mU/L,t =-6.11、,P＜0.001];低碘组小鼠骨髓、外周血TSHβ-Ⅴ mRNA表达水平[(9.62±0.60)、(9.25±0.83)]均低于正常对照组(7.69±0.36、7.11±0.41,t=6.77、5.64,P均＜0.001);低碘组小鼠甲状腺TSHβ-Ⅴ mRNA表达(9.32±0.91)与对照组(9.12±0.62)相比较,差异无统计学意义(t=0.45,P＞0.05);在骨髓、外周血、甲状腺未检出天然型TSHβ;垂体中TSHβ-Ⅴ mRNA和天然型TSHβ表达水平(1.99±0.61、- 7.17±1.78)均高于对照组(5.75±0.98、-1.43±0.51,t=-8.02、- 7.60,P均＜0.01].结论 低碘饮食引发小鼠甲状腺功能低下,抑制骨髓和外周血TSHβ-Ⅴ mRNA的表达,提示免疫系统来源的TSHβ-Ⅴ可能具有比天然型TSHβ更重要的免疫-甲状腺调节作用.     

正常足月新生儿脐血甲状腺激素水平的研究

目的探讨正常足月新生儿脐血甲状腺激素的水平,为临床尽早诊断和治疗新生儿甲状腺功能异常疾病提供依据。方法随机选择在复旦大学附属妇产科医院分娩的193例母亲孕期甲状腺功能正常足月新生儿,断脐后采集脐血,通过化学发光免疫分析法测定各项甲状腺激素水平,并同时采集新生儿3天动脉血检测其甲状腺功能,分析新生儿脐血代替3天动脉血甲状腺激素可行性,从而研究脐血甲状腺激素的参考范围。结果（1）脐血甲状腺激素各项指标参考范围：脐血甲状腺激素为正态分布,TSH（5．375±1．572）、TT3（36．576±8．595）、TT4（8．122±1．019）、FT3（1．657±0．271）、FT4（0．960±0．117）。（2）脐血代替新生儿3天动脉血甲状腺激素具有可行性：脐血和新生儿3天动脉血甲状腺激素五指项标（TSH、TT3、TT4、FT3、FT4）均成正态性分布,新生儿3天动脉血与脐血甲状腺激素均为正相关（P〈O．05）,TSH、TT3、TT4、FT3、FT4的回归方程分别为Y=84．215＋0．067X（P〈0．05）、Y=8．765＋0．457X（P〈0．05）、Y=1．021＋1．245X（P〈0．05）、Y=1．856＋0．272X（P〈0．05）、Y=8．765＋0．457X（P〈0．05）,可以用脐血推算新生儿3天动脉血中的甲状腺激素水平。结论用脐血代替具有创伤性的动脉穿刺血分析甲状腺激素水平,既能为患儿家长所接受,也能尽早发现及干预新生儿甲状腺功能异常疾病。     

New approaches to the treatment of acute renal failure

At present, the clinician is left in a relatively dependent position when encountering a patient with established acute renal failure (ARF). Clearly, interventional therapies that can significantly influence the process of recovery from ARF are limited. Although a variety of manipulations and drugs will protect against the loss of renal function when administered prior to the initiation of a renal insult, the clinician usually encounters a patient after ARF has been established. Thus, pertubations that will protect against the development of ARF or modify the severity of the renal insult are not applicable. Moreover, it is clear that the mortality and morbidity for patients with ARF is unacceptably high. Although a variety of supportive measures such as peritoneal/hemodialysis or continuous arteriovenous hemofiltration are now applicable to patients of almost any size or weight, patients continue to diewith but perhaps notof ARF. This article will review several new agents that act to enhance the restoration of renal function and result in accelerated recovery of both glomerular and tubular function, following an established acute renal insult: adenine nucleotides, thyroxin, and calcium channel blockers.     

慢性收缩性心力衰竭与正常甲状腺功能病态综合征的临床观察

目的观察慢性心功能不全患者血清甲状腺激素水平的变化,并探讨其临床意义。方法用放射免疫法测定58例心功能Ⅲ～Ⅳ级患者,60例心功能Ⅰ～Ⅱ级患者及62例心功能正常患者血清甲状腺激素（游离三碘甲状腺原氨酸FT3,游离甲状腺素FT4,总三碘甲状腺原氨酸T3,总甲状腺素T4）及促甲状腺素（TSH）水平,并进行比较。结果心功能Ⅲ～Ⅳ级患者血清FT3、T3水平明显低于心功能Ⅰ～Ⅱ级患者和心功能正常患者,差异有统计学意义（P〈0．05）。结论慢性心功能不全患者血清甲状腺素水平对心功能患者病情判断及预后有一定临床参考价值。     

Integrating Basic Research on Thyroid Hormone Action into Screening and Testing Programs for Thyroid Disruptors

Thyroid hormone signaling is highly conserved among all the vertebrates, and appears to be present in some invertebrates. Both the components that comprise the system and its general role in development and physiology are evolutionarily conserved, although specific events regulated by thyroid hormones, such as amphibian metamorphosis, may differ among taxonomic groups. The articles in this issue review the thyroid systems of mammals (specifically humans and rodents), fish, amphibians, and birds, and the states of the assays and endpoints used to detect disruption of the thyroid system within a toxicological paradigm. It must be noted that while reptiles represent an enormously important group, they were excluded because there was not enough information in the literature on thyroid toxicology in reptiles at the time that this series of reviews was drafted. Each review highlights the best assays for current regulatory use and those that may be considered for development for future use and research. However, it is important to remember that thyroid research is moving ahead at a fast pace. New thyroid research will impact the design of future thyroid assays used for the detection of thyroid system disruption in ways that may not be anticipated at the time of this writing. Several new areas of exploration are discussed that reveal potential sites of disruption in the thyroid system, including (1) the importance of the neural drive for TSH upregulation, (2) thyroid hormone transport, including cellular transporters like monocarboxylate anion transporter 8 (MCT8) that can regulate thyroid hormone action at the cellular level, and thyroid hormone-binding proteins in the serum that have been shown to differentially bind to environmental chemicals (e.g., certain PCB congeners), and (3) the deiodinases as a target for disruption of thyroid hormone activity in the peripheral thyroid system. The review papers in this issue represent the current state of thyroid assays and endpoints for detection of chemicals that disrupt the thyroid system.     

小剂量甲状腺素在慢性阻塞性肺疾病患者机械通气中的应用价值

目的探讨慢性阻塞性肺疾病(COPD)患者行机械通气时应用小剂量甲状腺素的临床疗效。方法 COPD合并Ⅱ型呼吸衰竭行机械通气患者67例,随机分为常规治疗组(A组)32例和在常规治疗基础上加用小剂量甲状腺素组(B组)35例,观察2组血清甲状腺素(T_3、T_4、TSH)水平及心率、血气(PaO_2、PaCO_2)变化,记录撤机成功率和机械通气时间。结果 B组治疗后3 d时T_3、T_4水平较治疗前明显提高,PaO_2、PaCO_2明显改善,差异有统计学意义(P均<0.05),5d左右达正常范围;TSH、心率无明显变化(P均>0.05)。A组治疗后各时点T_3、T_4、TSH水平及心率、PaO_2、PaCO_2变化较治疗前无明显差异(P均>0.05)。B组治疗后各时点T_3、T_4、心率、PaO_2、PaCO_2与A组比较差异有统计学意义(P均<0.05),B组撤机成功率及机械通气时间均优于A组(P<0.05)。结论 COPD患者行机械通气时应用小剂量甲状腺素可明显提高治疗效果。     

甲状腺功能亢进症患者治疗前后的脑功能及脑血流动力学改变

目的：探讨甲状腺功能亢进症患者治疗前后的脑功能及脑血流动力学改变。方法：对296例临床诊断甲状腺功能亢进症患者,在抗甲状腺药物或放射性~(131)I治疗前后行脑电图(EEG)检查,其中138例同时做经颅多普勒超声(TCD)检测。结果：治疗前EEG异常率68．9%(204/296),主要表现为α波频率增快,β活动增多、波幅增高,出现散在及阵发性θ、δ活动。EEG癎样放电检出率为27% (80/296)。93%(128/138)血流速度增快,76%(105/138)搏动指数增高,57%(79/138)伴有血管杂音。治疗后EEG异常率下降到15．2%,血流速度及搏动指数降低,血管杂音消失。结论：EEG和TCD是客观评定甲状腺功能亢进症患者脑功能和脑血流变化的敏感指标。脑功能和脑血流动力学的改变与甲状腺激素分泌过多有关。