her1 and her13.2 are jointly required for somitic border specification along the entire axis of the fish embryo

Delta-Notch and FGF signaling are involved in the control of somitogenesis in zebrafish. her genes are generally known as downstream targets of Delta-Notch signaling, but the her13.2 gene from zebrafish has recently been shown to depend on FGF signaling only. We have here studied the functional role of her13.2 in conjunction with her genes that are under Delta-Notch control. We show that joint inactivation of her1 and her13.2 leads to a complete loss of all somitic borders, including the most anterior ones. This somitic phenotype is much stronger than would be expected from the effects of the inactivation of either gene alone. A joint inactivation of her13.2 and her7, which is a paralogue of her1, does not show this enhanced effect. Thus, our results confirm inferences from in vitro studies that her1 and her13.2 form specific heterodimers, which may directly be required for regulating further target genes. These two her genes thus constitute the link between Delta-Notch pathway and FGF signaling during entire somitogenesis. We show that this interaction is conserved in the rice fish medaka, as a joint inactivation of the respective orthologues leads also to the same phenotype as in zebrafish. In addition, our results suggest that the mechanisms for anterior and posterior somite formation are not principally different, although the anterior somites often seem more refractory to genetic perturbations.     

关节镜下髁间窝成形术治疗髁间窝撞击综合征病人膝关节屈伸功能受限

目的:对髁间窝撞击综合征致膝关节屈伸功能受限患者关节镜下髁间窝成形手术疗效的探讨。方法:2008年2月-2009年7月选择关节镜下确诊骨性关节炎伴髁间窝撞击综合征病人45例,对所有患者行关节镜下髁间窝扩大成形术。结果:术后患者膝关节屈伸功能明显改进,对其中42例患者进行术后6个月随访,发现患者膝关节疼痛明显缓解或消失,关节屈伸功能较术前得到明显改善。术前Lysholm评分平均(48.7±13.1)分(差),术后平均(87.0±7.3()良),关节功能均获明显改善(P<0.001)。结论:髁间窝撞击综合征是导致该病患者膝关节疼痛及屈伸功能受限的主要原因,关节镜下髁间窝扩大成形术对该病有明显的疗效。     

Effect of photoperiod on vasopressin-induced aggression in Syrian hamsters

Syrian hamsters are photoperiodic and become sexually quiescent when exposed to short "winter-like" photoperiods. In short photoperiods, male hamsters display significantly higher levels of aggression than males housed in long photoperiods. Arginine-vasopressin (AVP) within the anterior hypothalamus (AH) has been reported to modulate aggression in hamsters housed in long photoperiods. Previous studies have shown that AVP can facilitate aggression and its effects appear to be mediated by AVP V(1a) receptors (V(1a)R). In the present study, we investigated whether the increased levels of aggression observed after exposure to short photoperiod were the result of an increased responsiveness to AVP within the AH. Injections of AVP into the AH significantly increased aggression in hamsters housed in a long photoperiod, but had no effect in hamsters housed in a short photoperiod. In addition, injection of a V(1a)R antagonist into the AH significantly inhibited aggression in hamsters housed in long photoperiod, but had no effect in hamsters housed in a short photoperiod. These findings indicate that AVP within the AH increases aggression in hamsters housed in long photoperiods, but not in hamsters housed in short photoperiods.     

Proliferating cells in the rat anterior pituitary during the postnatal period: immunoelectron microscopic observations using monoclonal anti-bromodeoxyuridine antibody

Proliferating cells in the male rat anterior pituitary at 1, 3, 5, and 8 weeks of age were labeled with bromodeoxyuridine (BrdU) and studied by light and electron microscopic immunocytochemistry using anti-BrdU. They decreased in number from 402±31/mm² at 1 week to 50±1.5/mm² at 8 weeks, while their cell area increased by about twofold during this period. They had a slightly higher nucleus/whole cell (N/C) ratio than non-proliferating cells. According to their ultrastructure we classified them into granular and agranular cells. The percentage of granular cells ranged from 73% to 82% of all the proliferating cells during the period studied. They had many granules of various sizes and shapes, and some contained growth hormone and prolactin. Agranular cells, constituting 18–27% of proliferating cells, were small and had a high N/C ratio, indicating their immaturity. Moreover, they showed several features of folliculo-stellate (FS) cells: they showed no secretory granules in the cytoplasm, extended thin cytoplasmic processes, and sometimes they constructed a follicle among them. These results suggest: (1) the majority of proliferating cells were mature cells producing anterior pituitary hormone(s) and (2) most of the agranular proliferating cells maybe FS cells. The possibility of the latter is discussed.     

BMP receptor IA is required in the mammalian embryo for endodermal morphogenesis and ectodermal patterning

BMPRIA is a receptor for bone morphogenetic proteins with high affinity for BMP2 and BMP4. Mouse embryos lacking Bmpr1a fail to gastrulate, complicating studies on the requirements for BMP signaling in germ layer development. Recent work shows that BMP4 produced in extraembryonic tissues initiates gastrulation. Here we use a conditional allele of Bmpr1a to remove BMPRIA only in the epiblast, which gives rise to all embryonic tissues. Resulting embryos are mosaics composed primarily of cells homozygous null for Bmpr1a, interspersed with heterozygous cells. Although mesoderm and endoderm do not form in Bmpr1a null embryos, these tissues are present in the mosaics and are populated with mutant cells. Thus, BMPRIA signaling in the epiblast does not restrict cells to or from any of the germ layers. Cells lacking Bmpr1a also contribute to surface ectoderm; however, from the hindbrain forward, little surface ectoderm forms and the forebrain is enlarged and convoluted. Prechordal plate, early definitive endoderm, and anterior visceral endoderm appear to be expanded, likely due to defective morphogenesis. These data suggest that the enlarged forebrain is caused in part by increased exposure of the ectoderm to signaling sources that promote anterior neural fate. Our results reveal critical roles for BMP signaling in endodermal morphogenesis and ectodermal patterning.     

Material and functional properties of articular cartilage and patellofemoral contact mechanics in an experimental model of osteoarthritis

The purposes of this study were to determine the in situ functional and material properties of articular cartilage in an experimental model of joint injury, and to quantify the corresponding in situ joint contact mechanics. Experiments were performed in the anterior cruciate ligament (ACL) transected knee of the cat and the corresponding, intact contralateral knee, 16 weeks following intervention. Cartilage thickness, stiffness, effective Young’s modulus, and permeability were measured and derived from six locations of the knee. The total contact area and peak pressures in the patellofemoral joint were obtained in situ using Fuji Pressensor film, and comparisons between experimental and contralateral joint were made for corresponding loading conditions. Total joint contact area and peak pressure were increased and decreased significantly (=0.01), respectively, in the experimental compared to the contralateral joint. Articular cartilage thickness and stiffness were increased and decreased significantly (=0.01), respectively, in the experimental compared to the contralateral joint in the four femoral and patellar test locations. Articular cartilage material properties (effective Young’s modulus and permeability) were the same in the ACL-transected and intact joints. These results demonstrate for the first time the effect of changes in articular cartilage properties on the load transmission across a joint. They further demonstrate a substantial change in the joint contact mechanics within 16 weeks of ACL transection. The results were corroborated by theoretical analysis of the contact mechanics in the intact and ACL-transected knee using biphasic contact analysis and direct input of cartilage properties and joint surface geometry from the experimental animals. We conclude that the joint contact mechanics in the ACL-transected cat change within 16 weeks of experimental intervention.     

鲤科鱼类前方椎体的形成及其在系统发育上的意义

本文对九种鲤科鱼类与中国胭脂鱼幼体的前方椎体的发育进行了比较。观察结果表明这两个科鱼类的前方椎体发育是近似的,它们的魏氏小骨有共同的来源;魏氏复合骨由前方椎体上方的第二骨化中心形成,这个骨化中心与第三和第四上神经骨相当。另一方面,胭脂鱼幼体的第二椎体副突已与第四椎体的胸肋相接;魏氏复合骨的扩展是骨化中心背脊部均匀地发生的,这些与鲤科有着明显的不同。鲤科幼体的魏氏复合骨发育具有共同的特点,第二骨化中心的前方有一棘状物在早期出现,它代表了第三上神经骨伸出部份。但随后的发育可以区分为两种不同方式:一种为雅罗系鱼类所具有,即第二骨化中心以棘状物的扩展为主,前、后棘存在并有缝合线相连;另一种为鲃系鱼类所有,即第二骨化中心的发育以其背中部伸出的实心嵴突为主,仅有不发达的前棘,此系属于派生性结构。与魏氏复合骨相关的是2—3椎体间的关系也有相应的差别:雅罗系鱼类的幼体其2—3椎体间分离(仅鳑(鱼皮)亚科鱼类例外),而鲃系鱼类的幼体其2—3椎体愈合。由于幼体魏氏复合骨与椎体的特征比成体表现更为明显,它们在系统发育上能提供更为清楚的信息。     

Cellular mechanisms of estrogen-and dopamine-induced control of glandular kallikrein in the anterior pituitary of the rat

Glandular kallikrein (GK, a trypsin-like serine protease) exhibits estrogen induction and dopamine repression in rat pituitary lactotrophs. Steroid induction may reflect primary actions to increase selectively the synthesis of specific proteins, or may be part of broad cellular responses secondary to steroid-induced phenotype transitions. This study examined the cellular mechanisms underlying estrogen and dopaminergic control of lactotroph GK using a quantified immunocytochemical approach. Pituitaries from ovariectomized rats exhibited little GK staining. Estradiol treatment for 10 days produced dose-dependent increases in pituitary mass, the percentage of lactotrophs (indicating lactotroph proliferation) and the percentage of GK-positive cells. Also, GK staining intensity was dependent upon estradiol dose, increasing 4-fold between 5 g and 50 g/48 h. Dopamine receptor blockade with haloperidol (2.5 mg/kg/24 h) elicited weak GK immunostaining in 46% of the lactotrophs in the absence of estradiol, and markedly potentiated GK staining intensity elicited with low but not high doses of estradiol. The results suggest that GK induction is a primary estrogen effect, and is not secondary to a phenotype transition: the induction is enhanced by estrogen-induced lactotroph proliferation. Dopaminergic systems strongly inhibit GK induction by low estradiol levels. This dopaminergic modulation may shift the induction of lactotroph GK to physiological events associated with high estradiol levels or low dopaminergic tone.     

静脉全麻联合超声引导下前锯肌平面+肋间神经阻滞应用于胸腔镜肺楔形切除术效果分析

摘要 目的：探讨静脉全麻联合超声引导下前锯肌平面+肋间神经阻滞应用于胸腔镜肺楔形切除术效果。方法：选择2021年10月至2022年12月来我院诊治的60例行胸腔镜肺楔形切除术患者,根据随机数字表法,将60例患者分为对照组（30例）与观察组（30例）,对照组30例患者行全麻联合胸椎旁阻滞+肋间神经阻滞的麻醉方法,观察组30例患者行全麻联合前锯肌＋肋间神经阻滞的麻醉方法。对比两组患者监测入室时（T0）、插管即刻（T1）、手术切皮时（T2）、拔管即刻（T3 ）时的平均动脉压及心率,对比两组患者术后2 h、4 h、12 h、24 h、48 h的静息、咳嗽状态下的疼痛评分,对比两组患者T0-T3点的应激反应指标,对比两组患者术中血管活性药的使用剂量,对比两组患者围术期的不良反应发生率。结果：与T0点相比,观察组在T1、T2、T3时的平均动脉压、心率均有明显增加（P<0.05）,而在T1点时,两组比较无差异（P>0.05）;T2、T3点时观察组的平均动脉压、心率明显较对照组低（P<0.05）。随着术后时间延长,两组静息、咳嗽状态下的疼痛评分明显降低（P<0.05）,而同时间点组间对比无统计学意义（P>0.05）。与T0点相比,观察组在T1、T2、T3时的肿瘤坏死因子、白介素6、白介素10水平均有明显增加（P<0.05）,而同时间点观察组与对照组对比无统计学意义（P>0.05）。观察组术中血管活性药的使用剂量明显较对照组低（P<0.05）。观察组的不良反应发生率16.77%低于对照组23.33%,但组间对比无统计学意义（P>0.05）。结论：行静脉全麻联合超声引导下前锯肌平面+肋间神经阻滞的胸腔镜肺楔形切除术者血流动力学更加稳定,术中所需血管活性药物用量明显降低。     

The prolactin and growth-hormone producing cells of the guinea-pig pituitary

Summary Different immunohistochemical techniques were used to identify the prolactin and growth hormone producing cells (STH cells) in the pituitary of normal guinea pigs at the ultrastructural level.Prolactin cells revealed two main aspects: 1. Cells with granules from 2500 to 3500 Å in diameter some of which are irregularly shaped. These granulations are scattered throughout the whole cytoplasm. The rough endoplasmic reticulum is well developed and organized in parallel lamellae. 2. In cells of the second type the granules are less numerous and smaller in diameter (1800 to 2500 Å) and the rough endoplasmic reticulum is less well developed.The cytoplasm of the STH cells contains many more round granules (generally grouped) which also range from 2500 to 3500 Å in diameter.The prolactin molecules and the STH molecules are essentially confined to the granules but with the immunocytochemical technique before embedding a slightly diffuse reaction appeared in the entire cytoplasm. These results are discussed.This work was supported by a grant from U.E.R. III LilleChercheur I.N.S.E.R.M.