Mitochondrial aspartate glutamate carrier (citrin) deficiency as the cause of adult-onset type II citrullinemia (CTLN2) and idiopathic neonatal hepatitis (NICCD)

 By using homozygosity mapping and positional cloning, we have shown that adult-onset type II citrullinemia (CTLN2) is caused by mutations of the SLC25A13 gene, which is localized on chromosome 7q21.3 and encodes a mitochondrial solute carrier protein named citrin. So far, we have reported nine mutations, most of which cause loss of citrin, and we have established several methods for DNA diagnosis. These methods have shown that more than 90% of the patients diagnosed as suffering from CTLN2 by enzymatic analysis carry SLC25A13 mutations in both alleles, indicating that CTLN2 is caused by citrin deficiency. Furthermore, by using the same DNA diagnosis methods, we discovered that 70 neonates or infants suffering from a particular type of neonatal hepatitis carry the same SLC25A13 mutations. Since the symptoms of the neonates are different from those of the more severe CTLN2 and usually ameliorate without special treatment, we designated the neonatal disease neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD). We conclude that citrin deficiency causes NICCD in neonates and CTLN2 in adults through the additional effects of genetic or environmental modifiers. Since the function of citrin, together with that of an isoform, aralar, was found to be as a mitochondrial aspartate glutamate carrier, the various symptoms of NICCD and CTLN2 may be understood as caused by defective aspartate export from the mitochondria to the cytosol and defects in the malate aspartate shuttle. It is, however, still difficult to understand the cause of the hepatic deficiency of argininosuccinate synthetase protein in CTLN2. Received: March 20, 2002 / Accepted: March 28, 2002     

MTS1／p16抑制基因的克隆及其对宫颈癌细胞系的影响

利用重组ＲＴ－ＰＣＲ方法从人胎盘中扩增多重肿瘤抑制基因（ＭＴＳ１）全长ｃＤＮＡ片断，克隆测序后，亚顾隆入哺乳动物高铲表达质粒ｐＣＥＰ中。将表达质业转染两种遗传背影不同的吕颈癌细胞系，发现外源基因ＭＴＳ１／ｐ１６基因的导入对ＨＰ〖Ｖ阳性的宫颈癌细胞系具有明显生长抑制作用，并出现细胞滞留Ｇ１期的特性。     

QUANTIFICATION OF THE REM SLEEP CYCLE AS A RHYTHM

The goal of this study was to develop an objective quantitative method for representing the temporal organization of sleep in terms of the period and rhythmicity of REM sleep occurrences. Data on normative human sleep, already scored for stage REM and not stage REM, were subjected to a “binary autocorrelation.” The mean period over 92 nights of sleep for 10 Ss was 101.5 min and quite stable. Data is also presented on variability of the rhythm in terms of an “index of rhythmicity.” Measures of temporal organization may prove to be as significant for sleep research as amount of the various sleep stages.     

Effects of aging on luteinizing hormone release in different physiological states of the female golden hamster

Effects of aging on estrous cycles and LH release in response to luteinizing hormone releasing hormone (LHRH), castration, and estradiol benzoate were studied in the female golden hamster (Mesocricetus auratus). About 80% to 90% of female golden hamsters still cycled regularly when reaching 19–22 months of age. However, some animals showed age-induced irregularity of the estrous cycle which included an interruption of complete absence of estrous vaginal discharge. Young female hamsters (3–5 months) had significantly (p<0.01) higher basal LH concentration than old animals (19–22 months) in the morning of each stage of estrous cycle. LHRH elicited about 20–30 fold increase in serum LH concentrations in both young and old hamsters. No significant difference in LH release was observed between young and old hamsters in response to LHRH. In acyclic hamsters, the peak of LH release in response to LHRH was delayed. LHRH-induced LH release was greater in the morning of proestrus than during diestrus in both young and old hamsters. LH increase was significantly greater in the young than in old hamsters on the 13th and 15th day after castration. However, positive feedback stimulation of LH release by estradiol benzoate was the same in both young and old hamsters. These results indicate that in the female hamster, LH response to acute stimuli such as LHRH and estrogens is the same in the young as in the old animal and that circulating basal LH concentration may decrease or its degradation or clearance may increase during the aging process in female golden hamsters. Irregularity of estrous cycles in aging hamsters may be related to delayed responsiveness of pituitary LH to LHRH stimulation.     

Setting out the frame conditions for feasible use of FFPE derived RNA

Introduction

The usage of formalin-fixed paraffin embedded (FFPE) tissue is characterized by its long shelf-life and simple handling. Therefore it is the most commonly available tissue specimen in routine diagnostics and histological studies. Formaldehyde fixation may result in RNA degradation and cross linking with proteins, while storage conditions also affect RNA integrity. The present study was designed to investigate the influence of these factors on RNA analysis.

Reproduction of menstrual changes in transplanted human endometrial tissue in immunodeficient mice

BACKGROUND: Cultures of human endometrial tissue are useful for analysing the mechanisms underlying the menstrual cycle. However, long-term culture of endometrial tissue is difficult in vitro. Xenotransplantation of normal human endometrial tissue into immunodeficient mice could allow prolonged survival of the transplanted tissues. METHODS: Proliferative-phase endometrial tissue samples from three women were transplanted into the subcutaneous space of ovariectomized, immunodeficient, non-obese diabetic (NOD)/severe combined immunodeficiency (SCID)/gammaC(null) (NOG) mice. The mice were treated with 17beta-estradiol (E2) for the first 14 days after transplantation, followed by E2 plus progesterone for the next 14 days. The transplants were investigated morphologically and immunohistochemically at various times after implantation. RESULTS: The transplanted tissues contained large numbers of small glands, pseudostratification of the nuclei and dense stroma after treatment with E2 alone. After treatment with E2 plus progesterone, subnuclear vacuolation, luminal secretion and decidualization of the stroma were observed. When the hormone treatment ceased, tissue destruction occurred and the transplants returned to the proliferative phase. Lymphocytes were identified immunohistochemically: the numbers of CD56-positive and CD16-negative cells increased significantly in the stroma during the late secretory phase (day 28). CONCLUSIONS: Human endometrial tissue transplanted into NOG mice showed similar histological changes to eutopic endometrial tissue during treatment with sex steroid hormones for 1 month. Moreover, lymphocytes were produced in the transplanted human endometrial tissue. This system represents a new experimental model of the human endometrium in vivo.     

马桑内酯对星形胶质细胞细胞周期变化的影响

胶质细胞细胞周期的改变，会导致细胞自身功能的改变．从而引发一些疾病的形成。研究致痫时星形胶质细胞细胞周期的变化，可能对癫痫的形成机制提供新的思路。用马桑内酯（CL）刺激体外纯化培养的海马星形胶质细胞2、4、6、8h后．应用流式细胞技术测定越形胶喷细胞细胞周期各时期细胞的变化．结果显示：CL作用4h后，G1期细胞数较对照组和2h组明显下降（P〈0．05），S期和G2＋M期比对照组明显增高（P〈0．05）。同时细胞凋亡也随着时间的延长而增加（P〈0．05）。本实验结果提示致痫时星形胶质细胞细胞周期会发生改变．即细胞由G1／G0期向S和G2＋M期快速转化。     

A method for assessing muscle fatigue during sprint exercise in humans using a friction-loaded cycle ergometer

This study investigated the mechanical changes induced by muscle fatigue caused by repeated sprints and determined whether a friction-loaded cycle ergometer has any advantages for assessing muscle fatigue. Nine subjects performed 15 sprints, each of 5 s with a 25-s rest, on a friction-loaded cycle ergometer. The averaged force, power and velocity of each push-off were calculated. Maximal power decreased by 17.9%, with a concomittent slowing of muscle contraction, but without any change in the maximal force. These results demonstrated that repeated sprints slow down muscle contraction, leading to a fall in maximal power without any loss of force. This would suggest that fast twitch fibres are selectively fatigued by repeated sprints. However, the ergometer used in the present study made it difficult to evaluate the relative influences of contraction velocity and sprinting time. This was certainly the most important limitation. On the other hand, it showed the advantage of measuring instantaneous power and total work dissipated in the environment simultaneously. It also permitted a force-velocity relationship to be obtained from a single sprint and this relationship is known to be closely related to the muscle fibre composition. Accepted: 5 March 1998     

小鼠第一次卵裂周期中线粒体分布的变化

用线粒体专一性活体荧光染色剂罗丹明１２３显示小鼠受精卵在第一次卵裂周期中Ｍ的分布变化，雌原核和雄原核在汇合之前，Ｍ在细胞质中呈弥散状随机分布，两原核汇合后，Ｍ在核周围略显聚集，第一次卵裂后期，Ｍ沿纺锤体微管和２个子核周围集中，但在赤道区域内明显稀少，预示出细胞分裂面的定位，这说明细胞质分裂是收综环收缩和细胞结构调整共同作用的结果。２－细胞阶段，Ｍ在细胞核周围明显聚集。２－细胞胚受秋水仙素作用后，Ｍ     

桑色素对小鼠T淋巴细胞体外活化、增殖和细胞周期的影响

目的:研究桑色素(morin)对小鼠T淋巴细胞活化、增殖和细胞周期的影响。方法:以刀豆蛋白A(ConA)刺激培养的淋巴结来源的小鼠淋巴细胞,再以不同终浓度的morin与T细胞共培养,利用流式细胞术(FCM),检测早期T细胞活化的标志CD69分子的表达,以羧基荧光素双醋酸盐琥珀酰脂(CFDA-SE)染色检测T细胞的增殖;以碘化丙锭(PI)染色分析T细胞的细胞周期。结果:小鼠T细胞培养6 h后,未经ConA刺激的对照组中CD69 T的细胞比率为(2.97±0.12)%,经ConA刺激的CD69 T细胞的比率明显增高,达到(72.52±0.66)%,与对照组相比差别明显(P<0.01)。终浓度为25、50、100μmol/L的morin均下调CD69 T细胞的比率,其中,100μmol/L的morin抑制作用最强,为(48.95±0.81)%,与对照组比较具有统计学意义(P<0.01)。CFDA-SE染色分析显示,ConA组培养48 h和72 h的T细胞的增殖指数(PI)分别为(1.58±0.04)和(1.95±0.02),各浓度的morin对ConA刺激的T细胞增殖,具有明显地抑制作用,以100μmol/L的morin抑制作用最明显。培养48 h的ConA组T细胞的PI为(1.02±0.02)、培养72 h的ConA组T细胞的PI为(1.03±0.01),与相应时间的对照组比较,均有统计学意义(P<0.01)。PI染色后流式细胞术分析的结果表明,ConA组处于S期的T细胞的比率为(27.05±0.39)%,显著高于对照组的比率(5.10±0.07)%。morin组中S期的细胞比率较高。结论:Morin可显著抑制ConA刺激的T细胞活化及增殖;其对增殖的抑制作用主要表现为S期的细胞的阻滞。