Circadian surges of LH in the ovariectomised rat occur coincident with enhanced pituitary responsiveness to GnRH

Summary Experiments are described in which we have investigated the responsiveness to GnRH of pituitary glands obtained from ovariectomised rats in which LH surges were induced by steroid priming (a) by estrogen implants and (b) by estrogen/progesterone injections. These treatments generate LH surges late in the light phase. Stimulation with GnRH in vitro revealed a large increase in responsiveness coincident with the surge of LH. We suggest that this effect is mediated through a self-priming effect of GnRH and that this in vitro technique may be used to detect hypothalamic release of GnRH.Supported by grants MA-7131 (M. Wilkinson) and MA-5401 (W.H. Moger) from MRC Canada     

胰腺导管腺癌和慢性胰腺炎中18q21杂合性缺失及相关性分析

目的 探讨18q21在人胰腺导管腺癌和慢性胰腺炎中杂合性缺失(LOH)的情况及其相关因素.方法 选择18q21上的位点RP11-729G3和RP11-850A17作为目的 片段,选择接近18号染色体着丝粒的位点RP11-621L6作为参照位点,利用细菌人工染色体(BAC)提取、纯化相应位点的DNA,用切口平移法分别标记生物素和地高辛后制成双色探针,应用荧光原位杂交技术(FISH)检测30例胰腺导管腺癌和10例慢性胰腺炎石蜡包埋组织切片中18q21 LOH情况,并收集、整理相应临床病理资料进行相关性分析.结果 30例胰腺导管腺癌中在RP11-729G3位点有25例(83.3%)有LOH,在RP11-850A17位点26例(86.6%)有LOH,其中25例在RP11-729G3和fuP11-850A17两个位点均有LOH,1例仅在RP11-850A17位点有LOH.10例慢性胰腺炎中均未发现18q21 LOH.经统计学分析发现,18q21 LOH在慢性胰腺炎和胰腺导管腺癌中差异有统计学意义(P<0.01),且RP11-729G3和RP11-850A17两个位点LOH有高度相关性(Phj系数=0.877),但和临床病理各因素间未发现明显相关.结论 18q21 LOH在胰腺导管腺癌中属于高频事件,并且位点RP11-729G3和RP11-850A17的LOH有高度相关性,可能在胰腺导管腺癌发生发展中起重要作用.在临床诊断中18q21LOH也能作为较特异的标记辅助诊断.     

Occurrence of secretogranin II in the prolactin-immunoreactive neurons of the rat lateral hypothalamus: an in situ hybridization and immunocytochemical study

The occurrence of secretogranin II in a neuron population of the rat lateral hypothalamus specifically detected by an anti-serum to ovine prolactin was examined. As this population was previously reported to synthesize dynorphin, the distribution of neurons recognized by ovine prolactin-, dynorphin B- and secretogranin II anti-sera was investigated on adjacent sections of hypothalami. The prolactin immunoreactive neurons were the only cells in the lateral hypothalamus to be stained by secretogranin II anti-serum. Moreover, coupling immunocytochemical detection and in situ hybridization with an oligonucleotide probe complementary to secretogranin II mRNA showed that these neurons expressed the secretogranin II gene. These new findings should help to study the physiological role of the prolactin immunoreactive neurons of the lateral hypothalamus.     

Effect of skin temperature on the ion reabsorption capacity of sweat glands during exercise in humans

The effect of skin temperature on the ion reabsorption capacity of sweat glands during exercise in humans is unknown. In this study, eight healthy subjects performed a 60-min cycling exercise at a constant intensity (60% VO_2max) under moderate (25°C) and cool (15°C) ambient temperatures at a constant relative humidity of 40%. The sweating rate (SR), index of sweat ion concentration (ISIC) by using sweat conductivity, esophageal temperature (Tes), mean skin temperature, and heart rate (HR) were measured continuously under both ambient temperatures. The SR and ISIC were significantly lower at the cool ambient temperature versus the moderate temperature. There were no significant differences in the changes in HR and esophageal temperature between these ambient temperature conditions, while the mean skin temperature was significantly lower at the cool ambient temperature by almost 3°C (P<0.05). The slopes of the relationships between Tes and the SR and ISIC were significantly lower and the thresholds of these relationships were significantly higher at the cool ambient temperature (P<0.05). The ion reabsorption capacity of the sweat glands was significantly lower (P<0.05) in a cool environment (0.21±0.04 vs. 0.52±0.06 mg/cm²/min at 15 and 25°C, respectively) as evaluated using the relationships for SR and ISIC. The results suggest that the ion reabsorption capacity of the sweat glands is influenced by skin temperature during exercise in humans.     

Changes of synapsin I messenger RNA expression during rat brain development

Synapsin I is a synaptic phosphoprotein that is involved in the short-term regulation of neurotransmitter release. In this report we present the first extensive study of the developmental expression of its corresponding messenger ribonucleic acid (mRNA) by in situ hybridization and northern blot analysis in rat brain. Synapsin I mRNA showed pronounced differences in expression in different brain regions during postnatal development. The early expression of synapsin I mRNA in ontogenetically older regions such as the thalamus, the piriform cortex and the hippocampus coincides with the earlier maturation of these regions, in contrast to its later expression in ontogenetically younger areas such as the cerebellum and the neocortex. An intriguing expression pattern was found in the hippocampus. In all hippocampal subregions synapsin I mRNA expression increased from postnatal day (PND) 1 to 17. After PND 17, however, there was a marked dissociation between persisting high expression levels in CA3 and the dentate gyrus and a strong decline in synapsin I mRNA expression in CA1. The persistence of synapsin I in some adult rat brain regions indicates that it plays a part in synapse formation during plastic adaption in neuronal connectivities.     

Dynamic properties of vestibular reflexes in the decerebrate cat

Summary Vestibulocollic (VCR) and vestibulo-ocular (VOR) reflexes were studied during angular rotation in the horizontal plane in precollicular decerebrate cats. Angular position was modulated by sinusoids or sums of sinusoids with frequencies ranging from 0.05 to 5 Hz.Reflex motor output was measured by recording electromyographic (EMG) activity of the lateral rectus and dorsal neck muscles and discharge of abducens motoneurons. Measured with respect to input angular acceleration VCR motor output displayed a second order lag at low frequencies, bringing mean EMG phase (–136 °) and gain slope (–35 dB/ decade) close to those of an angular position signal at 0.2 Hz. At higher frequencies the lag was counteracted by a second order lead bringing mean phase (–52 °) and gain slope (–5.6 dB/decade) back close to those of an angular acceleration signal at 3 Hz. By contrast, mean phase (–113 ° to –105 °) and gain slope (–21 to –28 dB/decade) of the VOR motor output remained close to those of an angular velocity signal across the entire frequency range.The data suggest that neural pathways producing the VCR receive selective input from irregular type horizontal semicircular canal afferents which provide one lag and one lead in the overall transfer function while the other lag and lead are produced by central pathways.Transaction of the medial longitudinal fasciculus (MLF), which eliminates all of the most direct (three neuron) arcs of the horizontal VCR, did not cause any detectable change in the horizontal VCR at either low or high frequencies. Reductions in overall gain occurred in some cases but these could be attributed to damage to axons outside the MLF. Less direct pathways, probably including vestibulo-reticulospinal pathways, are thus able to produce both the low-frequency, phase-lagging and high-frequency, phase-leading components of the horizontal VCR.Supported in part by NIH grants EY 02249, EY 00100, and NS 02619Recipient of NIH Fellowship NS 06030     

运用全染色体探针FISH技术进行罗伯逊易位携带者胚胎植入前诊断

目的运用全染色体探针荧光原位杂交技术(fluorescent in situ hybridization ,FISH)对14/21罗伯逊易位携带者的胚胎进行植入前遗传学诊断,达到优生目的.方法应用FITC、Texas标记的21/14全染色体探针对14/21罗伯逊易位携带者的胚胎活检后的单个卵裂球进行遗传学检测,选择正常信号或携带者信号核型胚胎进行移植.结果常规单精子显微注射-胚胎移植(intracytoplasmic sperm injection,ICSI)后获取胚胎12个,活检优质胚胎11个,杂交后有信号胚胎7个,其中1个正常胚胎,1个携带者胚胎;1个14单体胚胎,1个21单体胚胎,1个21三体胚胎,另2个胚胎活检后均为21号二体,无14号信号.结论运用14/21全染色体探针荧光原位杂交技术对14/21罗伯逊易位携带者的胚胎进行植入前遗传学诊断是能够将正常核型胚胎挑选出来进行移植,从而达到优生目的.     

传染性单核细胞增多症的临床病理及EB病毒定位性研究

目的 研究传染性单核细胞增多症(IM)的临床特征、病理特点、免疫表型和EB病毒原位感染特征,以提高对IM的认识和诊断水平.方法 采用HE染色以及免疫组织化学、原位杂交技术,结合临床资料分析,对15例IM进行了临床病理、免疫表型和EB病毒感染的研究.结果 (1)IM多见于儿童和青年人(中位年龄18岁),起病急,常有发热(12例),伴浅表淋巴结肿大,多数在短期内痊愈.(2)病变以T区增生为主,斑驳状改变常见,细胞混杂,种类多样,可见B细胞分化谱(活化淋巴样母细胞、免疫母细胞、浆样细胞、浆细胞),包膜不厚,间质不多.(3)病变中以CD3阳性的小T淋巴细胞为主,部分活化的淋巴样母细胞和免疫母细胞表达CD20和CD30,信号强弱不等,散在分布.(4)所有病例都有EB病毒编码的小RNA(EBER)阳性细胞,数量多少不一(10～100个/HPF),大中小淋巴细胞均可阳性,主要分布在T区,也见于套区、初级滤泡和生发中心内.结论 进一步确认了IM是EB病毒引起的一种急性自限性淋巴组织增生性疾病.IM在临床、病理、免疫表型和EB病毒感染方面都具有特点,只有综合考虑这4方面的信息才能减少错误,做出更准确的诊断.     

Numerical chromosomal aberrations in prostate cancer: correlation with morphology and cell kinetics

Eleven routinely processed radical prostatectomy specimens were studied for the presence of numerical chromosomal aberrations by means of in situ hybridization with nucleic acid probes specific for chromosomes 7, 10, 17, X, and Y. Cytogenetic information was correlated with morphology, tumour stage and volume as well as with cell kinetics, the latter being assessed by immunohistochemistry with antibodies raised against the proliferative cell nuclear antigen (PCNA) and against a formalin-resistant epitope of the Ki-67 antigen, MIB 1. In 5 of 11 cases, numerical aberrations of at least one chromosome were found. The cases with normal chromosome numbers were those with the smallest volumes of Gleason grade 4 and/or 5 tumour (mean 0.5 cm³) and represented tumours restricted to the prostate. Tumours with aberrations in the number of detected chromosomes showed advanced stages and large volumes of high-grade tumour (mean 12.5 cm³). All 4 tumours with positive surgical margins were recruited from a group with marked local heterogeneity in chromosome numbers. Immunostaining with MIB 1 and PCNA was most intense in areas of high-grade tumour and was positively correlated with the emergence of chromosomal aberrations. The data suggest that the appearance of numerical chromosomal aberrations in prostate cancer coincides with aggressive tumour behaviour and could be used as an additional prognostic marker.This work is part of E.K.'s doctoral thesis     

Apolipoprotein D is down-regulated during malignant transformation of neurofibromas

Apolipoprotein D (apoD) expression was studied in nonneoplastic peripheral nerve, neurofibromas (NFs), and malignant peripheral nerve sheath tumors (MPNSTs) by quantitative polymerase chain reaction, in situ hybridization, and immunohistochemistry. Multiplex quantitative polymerase chain reaction for messenger RNA was performed on a series of formalin-fixed and paraffin-embedded specimens that included 9 MPNSTs, 12 NFs, and 4 normal peripheral nerves. The average apoD expression was 108-fold decreased (DeltaCt = -7.3) in the MPNSTs compared with the NFs (P < .05). ApoD expression levels were 3.0-fold elevated (DeltaCt = 1.7) in the NFs compared with nonneoplastic peripheral nerve (P < .05). In situ hybridization for apoD RNA was performed on a separate series of 10 cases in which each microscopic section included both MPNST and the NF from which it arose. These studies confirmed elevated apoD expression in NFs compared with MPNSTs and demonstrated that this expression was variable among individual cells within the NFs. Differential expression by immunohistochemistry could only be demonstrated in selected areas, most likely because apoD protein is a small molecule that is secreted out of the cell into the extracellular space and plasma. ApoD expression initially increases a small amount with the formation of NFs from nonneoplastic peripheral nerve and subsequently decreases markedly as NFs transform into MPNSTs. This expression pattern may serve as a marker for cell cycle inhibition during peripheral nerve tumorigenesis.