Effect of Regain of Body Weight on Regional Body Fat Distribution: Comparison Between Pre- and Postmenopausal Obese Women

The aim of our study was to determine if regain of body weight increases visceral fat in obese women and if regain of weight has a different effect upon pre- and postmenopausal women. Twenty obese women (11 pre- and 9 postmenopausal) underwent a very low energy diet (VLED) for 2 weeks to lose weight. They then regained body weight in spite of the recommended hypocaloric diet. No significant modifications in body fat distribution indexes were found by computed tomography between VLED and after regain of weight. No significant changes were found in metabolic variables. No interactions between menopausal status and regain of body weight were observed. In conclusion, regain of weight does not seem to cause an increase in visceral fat; both pre- and postmenopausal women showed the same body fat distribution before weight loss and after regain of weight.     

植物愈伤组织培养中内外源激素效应的研究现状与展望

综述了外源激素对愈伤组织诱导、分化的影响,以及内源激素在愈伤组织培养过程中的变化规律。有关愈伤组织培养中外源激素作用的研究日趋细化,而激素变化与适宜继代周期的关系已成为研究热点。随着分子生物学与同位素标记等技术的引入,必将促进愈伤组织培养中激素相关基因调控机理的揭示,以及激素作用位点的精确定位,从而推动植物愈伤组织培养的迅猛发展。     

重组人生长激素治疗生长激素缺乏症的疗效观察

目的：正确评价重组人生长激素（rhGH）治疗儿童生长激素缺乏症（GHD）的疗效。方法：GHD患儿47例,给予rhGH0．1U／（kg．d）,疗程3个月,并对其疗效进行观察。结果：身高（height）由（122±17．67）cm增至（125．32±17．50）cm,生长速率（growthrate）由〈4cm／年增加到（10．40±3．74）cm／年。血清碱性磷酸酶（AKP）由（207±48．11）IU／L增至（261±45．29）IU／L。I型前胶原羧基端伸展肽（PICP）由（97．80±14．94）ng／ml增至（119．50±24．10）ng／ml值。肌酐（Cr）由（40．20±8．28）umol／L变为（36．50±8．33）umol／L值。结论：rhGH是治疗GHD有效的药物。     

Human Body Composition and the Epidemiology of Chronic Disease

Obesity and body fat distribution (FD) are established risk factors for chronic diseases. The body mass index (BMI) and the waist/hip circumference ratio (WHR) are used conventionally as indices of obesity and FD in epidemiological studies. Although some general limitations of these indices are recognized, others that affect their use in relative risks for disease are not well recognized. These include effects of sex, ethnicity, and especially age on the relationships between these indices and body composition, which can result in substantial misclassification of obesity and FD. There is considerable variability in body composition for any BMI, and some individuals with low BMIs have as much fat as those with high BMIs. This results in poor sensitivity for classifying levels of body fatness (e.g., too many “false negatives,” or overweight individuals classified as not overweight), and relative risks are attenuated across all categories of BMI. A more serious problem, however, is that at different ages the same levels of BMI correspond to different amounts of fat and fat-free mass. Data from the Rosetta Study and the New Mexico Aging Process Study show that older adults have, on average, more fat than younger adults at any BMI, due to the loss of muscle mass with age. As a result, the sensitivity of BMI cutpoints with respect to body fatness decreases with age, and the use of a fixed cutpoint for all ages results in “differential mis-classification bias.” Taken together, these issues sug- gest that the increases with age in the prevalences of overweight and obesity, and in the risks for chronic diseases, may be mis-estimated using BMI. Similar issues may affect the use of WHR for estimating prevalences and associated risks of FD. New field methods for estimating body composition are available that can be applied in large, epidemiologic follow-up studies of chronic diseases. These methods will allow epidemiologists to consider, for example, whether it is increased fat, or the replacement of fat-free mass with fat, with age that is associated with risk for chronic disease.     

Changes in Tissue Cellularity Are Associated with Growth Enhancement in Genetically Modified Arctic Char (Salvelinus alpinus L.) Carrying Recombinant Growth Hormone Gene

Biochemical and histological analyses were used to study the number and size of cells (cellularity) in tissues of fast-growing, genetically modified Arctic char (Salvelinus alpinus L.), overexpressing sockeye salmon (Oncorhynchus nerka) growth hormone gene (OnGH1). DNA contents of muscle, heart, and liver were compared in transformed, sibling (age control) and 1 year older (size control) char. Total white muscle cross-sectional area, white muscle fiber number, and total nuclei number within the muscle tissue were determined from one complete half-section of each fish. The analyzed tissues responded differently to growth hormone overproduction. In muscle tissue of OnGH1-transformed char, the enhanced growth was clearly associated with proliferation of muscle cells (hyperplasia), whereas in heart tissue both cell proliferation and increase in cell size (hypertrophy) were enhanced. The relative DNA concentration in the liver of transformed char was significantly greater than that of control fish, suggesting reduction in size of hepatic cells. Received June 29, 2000; accepted October 25, 2000     

重组人甲状旁腺素（1-34）在大鼠体内的组织分布和排泄

目的：研究重组人甲状旁腺素（1-34）[rhPTH（1—34）]在大鼠体内的组织分布和排泄情况,为进一步的临床实验提供参考。方法：用^125I-同位素示踪法结合TCA酸沉淀法测定各主要器官组织的总放射性浓度和酸沉淀部分放射性浓度,获得rhPTH（1-34）的尿粪排泄和胆汁排泄数据。结果：各主要器官组织的总放射性浓度排序由高到低依次为：尿、肾、膀胱、肠内容物、肌肉、血清、肾上腺、空肠、肝、肺脏、卵巢、肠淋巴结、脾、胸腺、心脏、脂肪、睾丸和脑;大鼠皮下注射。^125I-rhPTH（1-34）后,骨骼组织中放射性分布低于血浆,但消除缓慢,血浆浓度4h较15min降低了78％,而骨骼浓度多数仅降低了50％以下;注射后72h,尿、粪分别排出注入放射性量的73．6％±10．9％和3．2％±1．3％,尿、粪合计排出注入放射性量的76．8％±11,4％;注射后12h,胆汁中累积排出注入放射性的6．64％±1．04％。经分子筛排阻HPLC证实,^125I-rhPTH（1-34）不与大鼠的血浆蛋白发生结合。结论：rhPTH（1-34）在泌尿系统中的分布较高,在脂肪和脑中最低,提示药物不易透过血脑屏障;就全身放射性分布而言,在骨骼中分布较高,提示药物具有一定的靶向性;rhPTH（1-34）主要经尿的形式排泄。     

The Influence of Anatomical Boundaries,Age, and Sex on the Assessment of Abdominal Visceral Fat

CLASEY, JODY L, CLAUDE BOUCHARD, LAURIE WIDEMAN, JILL KANALEY, C DAVID TEATES, MICHAEL O THORNER, MARK L HARTMAN, ARTHUR WELTMAN. The influence of anatomical boundaries, age, and sex on the assessment of abdominal visceral fat. Single-slice abdominal computed tomography (CT) scanning has been used extensively for the measurement of abdominal visceral fat (AYF). Optimal anatomical scan location and pixel density ranges have been proposed and are specifically reported to allow for the replication and standardization of AVF measurements. Standardization of the anatomical boundaries for CT measurement of AVF and the influence of age and gender on results obtained with different boundary locations have received much less attention. To determine the influence of three boundary analysis methods (AVF-1, AVF-2, and AVF-3) on the measurement of AVF by CT, 54 older (60 years to 79 years) and 37 younger (20 years to 29 years) healthy men and women were examined. The measurement boundary for AVF-1 was the internal most aspect of the abdominal and oblique muscle walls, and the posterior aspect of the vertebral body. AVF-2 used fat measurements enclosed in a boundary formed by the midpoint of the abdominal and oblique muscle walls, and the most posterior aspect of the spinous process. AVF-3 used fat measurements enclosed in a boundary formed by the external border of the abdominal and oblique muscle walls, and the external border of the erector spinae. Greater AVF measures were obtained with AVF-2 and AVF-3 compared with AVF-1 (p<0.0001). These differences were greater in older compared with younger subjects (p<0.0001) and greater in women compared with men (p<0.02). The significantly greater AVF measurements obtained with AVF-2 and AVF-3 resulted from the inclusion of larger amounts of fat that are not drained by the portal circulation. This included retroperitoneal, intermuscular, and intramuscular lipid droplets, which increase with aging. On the basis of these results, we recommend the AVF-1 anatomical boundaries for the measurement of AVF in clinical investigations, particularly with older subjects. These data demonstrate the importance of precise and reproducible anatomical boundaries for the measurement of AVF, particularly in longitudinal studies.     

油菜生长发育期间内源激素含量的变化

初花期至盛花期华双3号、华杂4号、恢5900等3个品种花蕾的iPAs含量呈明显上升趋势,而秦油2号则刚好相反(表2)。对双低品种华双3号功能叶的研究表明：苗期至盛花期IAA含量始终最高,其后依次是GA1 3;、iPAs、ABA。功能叶IAA的含量在越冬期处于整个生育期的最低水平,蕾薹期达到高峰,随后下降：GA1 3和iPAs含量随生育进程逐渐升高,并在初花期达到峰值;ABA在苗期及抽薹后一直处于很低水平,但在越冬期达到最高值(图1、2)。蕾薹期IAA主要分布在幼嫩和正在生长的器官中并起重要作用,而在功能叶中相对要少;幼叶GA1 3和iPAs含量最高,功能叶其次,花蕾最低(表1)。角果皮与籽粒的内源激素含量差异极显著,在开花后第39天,籽粒中IAA、GA1 3;、iPAs的含量大大超过角果皮(表3)。结果 表明iPAs在促进籽粒的充实饱满、物质积累转化方面发挥重要作用。     

石斑鱼垂体腺苷酸环化酶激活多肽和生长激素释放激素基因的cDNA克隆及表达分析

垂体腺苷酸环化酶激活多肽 (PACAP)和生长激素释放激素 (GHRH)均属于血管活性肠肽家族成员 ,且两者前体基因在脊椎动物的鸟类、两栖类、鱼类中由同一基因编码 ,而哺乳动物是由两个不同基因编码。已有几例关于鱼类编码PACAP和GHRH基因克隆的报道 ,而关于重要海水养殖鱼类石斑鱼的PACAP和GHRH基因未见报道。克隆了PACAP GHRH前体cDNA序列 ,该前体有两种剪接方式 ,包括一个长序列和一个短序列 ,其中长序列编码PACAP和GHRH ,短序列缺失 10 5个碱基 ,仅编码PACAP而缺失编码GHRH的外显子区 ,同样情况在虹鳟和沟鲶中也有报道。通过半定量RT PCR方法对石斑鱼PACAP GHRH前体mRNA在胚胎发育和发育早期以及各部位的表达情况进行了分析。胚胎发育分析结果表明 ,从神经胚期开始 ,PACAP GHRH前体mRNA大量表达 ,提示该蛋白质在神经发育或神经营养方面具有重要作用。PACAP GHRH前体基因在中枢系统的表达量远高于外周组织。在鱼类的眼和鳃发现PACAP GHRH前体分布。     

鲑鱼生长激素cDNA的分子克隆和序列分析

从太平洋切奴克鲑鱼(Pacific Chinook Salmon,Oncorthychus tschawytscha)垂体poly(A)~+ RNA构建cDNA文库。按照鲑鱼生长激素(sGH)部分氨基酸序列合成两个寡聚脱氧核苷酸探针,它们分别与编码第1—7和第166—172氨基酸序列互补。用探针筛查cDNA文库,得到了完整的sGH cDNA克隆。cDNA序列已测定,包括编码210个氨基酸的编码序列。其中含有22个氨基酸的信号肽序列和188个氨基酸的成熟GH序列。该克隆还包括了5'端和3'端非翻译区,分别为72个和438个碱基对长。与Chum鲑鱼比较表明,核酸序列和氨基酸序列的同源性分别为97%和99%。     

青鱼生长激素cNDA的克隆与序列分析

从青鱼（Mylopharyngodon piceus）脑下垂体中提取总RNA,采用逆转录PCR法扩增出青鱼生长激素cDNA编码区,克隆到Pucm-T载体上。序列测定表明青鱼生长激素基因的开放阅读框架含有630bp,其中包括22个氨基酸的信号肽和188个氨基酸的成熟肽,青鱼生长激素基因的克隆成功为该基因的功能及应用研究奠定了基础。     

Reduction of Brain Calcium After Consumption of Diets Deficient in Calcium or Vitamin D

Abstract: Rats fed diets deficient in calcium or vitamin D for 4 weeks displayed hypocalcemia, as indicated by a 50% reduction in serum calcium and a sevenfold elevation of serum parathyroid hormone. These treatments also decreased the calcium content of brain tissue. On a regional basis. this effect was greatest in the brain stem (24% decrease) and least in striatum (10% decrease). Subcellular analysis indicated that the depletion of brain calcium was greatest in the soluble and the microsomal fractions. Infusion of calcium solutions reversed the depletion of brain calcium produced by dietary deficiencies. In control rats. parathyroidectomy or infusion of parathyroid hormone did not alter the calcium content of brain tissue, although these treatments affected the levels of calcium in the serum. In general, these treatments had no effect on the magnesium content of serum or brain tissue. However, vitamin D deficiency did increase the magnesium content of the myelin and synaptosomal fractions. This increase was reversed by parathyroidectomy. These observations demonstrate that long-term hypocalcemia produces distinct changes in the localization of calcium and magnesium in brain tissue. Furthermore. these studies suggest that though brain calcium levels are influenced by serum concentrations, serum changes must be of large magnitude and long duration for brain calcium levels to be affected.     

Efficacy of Chromium(III) Supplementation on Growth,Body Composition,Serum Parameters,and Tissue Chromium in Rats

Chromium(III) is often claimed to have a positive effect on body composition, while the responses in researches with supplementation of different chemical form of chromium are various and inconsistent. We have studied the effects of 6 weeks of treatment with three different forms of chromium (300 μg/kg) as chromium chloride, chromium tripicolinate, and chromium nanocomposite (CrNano) on growth, body composition, serum parameters, and tissue chromium in rats. The supplementataion of CrNano significantly increased average daily gain, food efficiency, and lean body mass and decreased fat mass and body fat proportion and serum levels of glucose, urea nitrogen, triglyceride, and insulin. Chromium contents in liver, kidney, and hind leg muscle were increased significantly with the addition of CrNano in diet. The results indicate that chromium nanocomposite has higher efficacy on growth and body composition compared to the traditional chromium agents.     

草鱼生长激素基因在毕赤酵母中的表达

将草鱼生长激素基因（cGH）的cDNA亚克隆到酵母表达载体pPIC9K中,经电击转化导入毕赤巴斯德酵母GS115菌株,获得转化子。菌落PCR技术筛选证实cGH已经整合到了酵母染色体上。对重组酵母进行诱导表达,SDS-PAGE和Western印迹分析,结果表明cGH的毕赤巴斯德酵母GS115菌株中获得了高效表达。     

猪生长激素基因在杆状病毒载体系统中的表达

通过对猪生长激素（ｐＧＨ）基因的ｃＤＮＡ进行测序,得到ｐＧＨｃＤＮＡ的全序列,并与Ｓｅｅｂｕｒｇ等报道的序列进行了比较和讨论。然后利用具人工合成启动子和多角体蛋白ＸＩＶ启动子的转移载体质粒ｐＳＸＩＶＶＩ＾＋Ｘ３／４构建出含ｐＧＨ基因的重组质粒ｐＸ３／４－ｐＧＨ。将ｐＸ３／４－ｐＧＨ与致死缺失型线性化ＡｃＭＮＰＶ－ＯＣＣ＾－ＤＮＡ共转染Ｓｆ９细胞,构建出既能形成多角体又能表达ｐＧＨ基因的苜蓿丫纹夜蛾