Fine structure of the carotid body of the midterm human fetus

Summary The human fetal carotid body was studied using both histochemical and electron microscopic methods. The glomus cells of a mid term fetal carotid body evidently contain catecholamines. This was demonstrated both by formaldehyder-induced fluorescence of the cells and by the presence of typical dense-cored vesicles (diameter 1430–3200 Å) in the cytoplasm of the chief cells. The glomus cells were densely innervated and the synapses found on their surface were probably cholinergic in type, containing agranular synaptic vesicles measuring 400–700 Å in diameter with a few dense-cored vesicles measuring 900 to 1300 Å. Synapses were not found in any other cell type within the glomus caroticum. The prominent feature of the glomus cell cytoplasm was the presence of the dense-cored vesicles. The density of the vesicular core varied only slightly from cell to cell. There were no perceptible differences in vesicular size between the different cells. The glomus cells were mostly surrounded by the processes of the sustentacular cells, which usually also surrounded the capillary walls. No glomus cells were ever found in direct contact with the capillary wall. The capillaries were wide and very numerous over the restricted area of the organ. They formed sinusoidal loops, probably anastomosing with each other. Finally, the features of the fine structure are discussed, correlating the present findings with our knowledge about the adult functional carotic body.     

人胚胎大脑海马发育的超微结构研究

本文借助电子显微镜技术对４ 月胎龄组及６ 月胎龄组水囊引产胎儿海马中段部位的神经细胞进行了超微结构观察、拍照,并对照片给予分析、讨论。结果显示：６ 月组部分神经细胞中细胞器较４ 月组发达。该结果可提示人胎儿海马发育中期（４ 月组） 神经细胞功能欠活跃,而到了较晚期（６ 月组） 神经细胞功能增强,细胞器发育较完善,功能活跃。     

人胎听皮质含生长抑素神经元的发育

用免疫组织化学ABC法,研究了16周至新生儿听皮质含SS神经元的发育.含SS神经元最早出现在24周,少数散在的含SS神经元分布在脑室下层、套层,多数分布在皮质Ⅳ到Ⅵ层.随后向浅层发育.提示发育顺序似从深层向浅层发育,深层含SS神经元发育、分化、成熟比浅层早.含SS神经元的胞体平均截面积随发育过程逐渐增大,但不匀速.低胎龄,突起数少而短,双极和多极神经元比例接近,随胎龄增大,多极神经元逐渐比例增高.皮质和皮质下白质散在分布合SS神经纤维.对新生儿听皮质各层含SS神经元进行灰度分析,听皮质含SS神经元的灰度从浅层到深层渐减.提示含SS神经元的活性深层比浅层高.含SS神经元的数量随胎龄增大呈增加趋势,孕期终末增幅明显,可能是发育活跃期,可能与生后语言功能发育有一定关系.     

Morphogenesis of intrahepatic bile ducts of the human fetus

Summary The development of the intrahepatic bile ducts of the human fetus was investigated by light and electron microscopy. Bile canaliculi with microvilli and junctional complexes are already found in the embryo of 7 mm. Some of them are of the intracellular type. At six to seven weeks, large bile canaliculi bounded by four to seven liver cells appear. Subsequently, bile canaliculi are formed predominantly between three to four adjoining liver cells and this arrangement persists throughout later fetal life.The early intrahepatic bile ducts develop around the portal vein as epithelial cell plates derived from the hepatic duct and the branches sprout from the epithelial cell plates in several different places. The epithelial cell plates are separated from each other by primitive connective tissue and they change into a complex network of bile ducts. Formation of the intrahepatic bile ducts is completed by three months.Biliary duct cells at the end of the developing bile ducts are thought to transform into liver cells. Therefore, at the ducts of Hering various transitional cells appear between biliary duct cells and liver cells.The fine structure of the developing liver cells and biliaryduct cells is also described.     

Biomechanical aspects of mandibular growth

The subject of this study was to analyse how functional parameters of stomatognathic systems are influenced by growth. For this purpose, two cephalometric radiographs of 65 patients with class-II-relation treated with functional appliances were superimposed on the occlusal plane. The two patient groups consisted of 32 open bite and 33 deep bite cases. The direction of the condylar growth significantly differed for both cases. Nevertheless the hypothesis could be confirmed that the original functional structure was hardly affected by growth.     

Branches of the thoracic sympathetic trunk in the human fetus

Summary The segmental organization of the thoracic sympathetic trunk and all its ramifications was studied in 6 human fetuses (16–22 weeks) by means of the acetylcholinesterase in toto staining method. Each trunk was divided into 12 sympathetic segments. A segment is defined as that part of the sympathetic trunk which is connected via its rami communicates with one spinal nerve, without discriminating between grey and white rami. The diameter of the rami communicantes and their direction towards the spinal nerves are variable. The number of peripheral segmental ramifications of the trunk is much larger than assumed previously. Each thoracic sympathetic segment gives off at least 4–5 nerves. Three categories of nerves are discerned: (1) large splanchnic rootlets confined to the greater, lesser and least thoracic splanchnic nerves, (2) medium-sized splanchnic nerves directed towards thoracic viscera, some of which give off branches towards costovertebral joint plexuses and, described for the first time in man, (3) small nerves which ramify extensively and form nerve plexuses in the capsule of the costovertebral joints. The majority of the ramifications is formed by the nerves of the third category. The existence of Kuntz's nerve, connecting the 2nd intercostal nerve and 1st thoracic spinal nerve, is confirmed in four specimens. The nerve plexuses of the costovertebral joints receive a segmentally organized innervation: they receive their input from the neighbouring sympathetic segment and the one cranial to it.It is concluded that the thoracic sympathetic branches in man show a complex, segmentally organized pattern and may have a considerable component of somatosensory nerve fibers. The complex relationships must be taken into account in surgical sympathectomies.     

国人胚胎顶骨组织结构的胎龄性变化

目的　完善国人胚胎颅顶骨发生及发育的形态学资料。方法　取第 9～ 38周人胚胎 32例的颅顶骨 ,用HE、硫堇 苦味酸法染色 ,光镜观察。结果　第 9周胚胎顶骨为一片间充质膜。第 10～ 12周胚胎的膜性顶骨内 ,血管丰富 ,有针片状骨小梁形成 ;第 13～ 16周胚胎顶骨内骨小梁增加 ,呈条索状。第 17周以后 ,顶骨内的骨小梁增粗增长 ,连接成骨小梁网 ,并有原始哈氏系统形成 ;第 2 9周以后 ,顶骨内的原始哈氏系统不断增加 ,原始密质骨逐渐形成。结论　人胚胎颅顶骨发育过程中有原始哈氏系统形成 ,胚胎颅骨的发育及结构特点与胚胎脑的不断生长 ,使其承受的重量不断增加有关     

临海地区围产儿出生缺陷监测资料分析

目的调查临海市临床出生缺陷的发生情况,探讨出生缺陷发生的相关因素,为制定新的决策提供依据。方法对2013年临海市出生缺陷监测医院收集的资料进行回顾性分析。结果临海市共监测9877例围产儿,其中出生缺陷儿138例,出生缺陷发生率为139．72／万。出生缺陷前三位依次为先天性心脏病、多指（趾）、马蹄内翻足。男女性出生缺陷发生率为151．46／万、I32．18／万。结论针对可能导致出生缺陷的各个环节,降低缺陷率的关键在于落实三级预防,加强孕前健康教育、孕期保健、产前筛查与产前诊断工作,早发现早干预。     

The growth of long bones in human embryological and fetal upper limbs and its relationship to other developmental patterns

Measurements were made of the long bones of the upper limbs (humerus, ulna, radius) of 58 aborted embryos and fetuses, developmental age from 8 to 14 weeks, crown-rump length (CRL) between 38 and 116 mm. The specimens were cleared and double-stained, using alcian blue and alizarin red S for a differential detection of cartilage and bone. The values of both the total length (TL) and the ossified part (OL) of each long bone were related to the fetal developmental age previously estimated by freshly measured CRL. The relationship to another developmental pattern, i.e. the number of ossified centres in the vertebral column, suggested that the OL values could be much more significant than TL for the assessment of fetal growth.     

瘦素及其受体在人胚胎小肠不同发育阶段的表达

目的对22例13周～24周胎龄早期胎儿空肠、回肠的组织发育和空肠、回肠内瘦素及其受体分布进行观察。方法采用苏木精-伊红和免疫组织化学SABC染色方法。结果在13周时,空肠和回肠均出现绒毛。20周时,空肠出现薄层黏膜肌,而回肠在24周时才可见黏膜肌,至此小肠壁四层结构才分界清楚。空肠及回肠在13周时,绒毛上皮细胞均呈瘦素及其受体免疫反应阳性。随胎龄增加,两者反应强度均无明显变化。结论人胚胎发育早期,在空肠和回肠黏膜上皮内有瘦素及其受体的表达,推测瘦素可能作为一种生长因子,参与早期小肠结构的发育。     

太原地区12375例围产儿出生缺陷分析

目的探讨近年来太原地区出生缺陷发生情况，为预防策略的制定提供依据。方法对1997年1月至2005年12月在山西医科大学第一、二医院终止妊娠的围产儿进行回顾分析。结果（1）出生缺陷率平均为162.42／万，几年来农村出生缺陷的发生率始终高于城市，2005年两地均有上升趋势。（2）出生缺陷的分布两地均以神经管畸形居于首位，且农村高于城市（P＜0．05）。（3）在同一居住地出生缺陷与胎儿性别无显著差异（P＞0．05）。结论为降低出生缺陷率。应健全农村妇幼保健网，广泛开展健康教育，加强围产保健，提高产前诊断水平。     

Correlation between the content of albumin and carotenoids in human vitreous body during prenatal development

The dynamics of the content albumin and carotenoids in human fetal vitreous body during weeks 16–31 of gestation was studied. The maximum values of total albumin (1.42 mg) and carotenoids (276 ng) during the studied period were recorded on weeks 20–22. Albumin concentration peaked during week 17 (2.11×10⁻⁴ mol/liter) and carotenoids during weeks 16–17 (about 0.045×10⁻⁴ mol/liter) of prenatal development. By week 31, the concentrations and total content of albumin and carotenoids in the vitreous body decreased. The physiological role of the studied components of the vitreous body for prenatal development of human eye is discussed. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 144, No. 11, pp. 522–525, November, 2007     

Innervation of pulmonary veins: Morphologic pattern and pathways of nerves in the human fetus

The aim of the study was to determine the anatomy of intrinsic nerves supplying human pulmonary veins (PVs). Twenty-two hearts of human fetuses with full sets of PVs were examined using a histochemical method for acetylcholinesterase in order to stain transmurally intrinsic neural structures on non-sectioned PVs for subsequent stereomicroscopic examination. Findings of the study demonstrate that epicardiac nerve extensions from both the dorsal right atrial and the middle dorsal subplexuses reached the right superior as well as the right inferior PVs, whereas the left superior PV was supplied by nerve extensions from the left dorsal subplexus. The left and middle dorsal subplexuses contributed nerves to the left inferior PV. The ganglia related topographically to PVs were patchy in distribution. On the left and right superior PVs, 38±6 and 31±3 ganglia were found, respectively, whereas 46±7 and 38±7 ganglia were identified on the left and right inferior PVs. The size of ganglia was similar for all four veins, ranging in area from 0.004±0.0003 to 0.007±0.0004 mm². The total area of ganglia distributed on a given PV was similar, ranging from 0.15±0.0003 to 0.25±0.0004 mm². The present findings demonstrate that the richest ganglion sites supplying intrinsic nerves to the human PVs are located on the posterior sides of both inferior and the left superior PVs and, therefore, these sites may be considered primary targets for focal pulmonary vein ablation in catheter-based therapy of atrial fibrillation.     

Origin of the styloglossus muscle in the human fetus

The origin of the styloglossus muscle was histologically studied bilaterally in nine human fetuses (18 sides). In all cases, the muscle originated in Reichert's cartilage, which gives rise to the temporal styloid process. We identified three types of variation: type A, an accessory muscle fascicle originating from the mandibular angle, found in 7 cases (12 sides); type B, where the styloglossus muscle was attached to the mandibular angle by fibrous tracts, found in three cases (4 sides); and type C, where an accessory muscle fascicle arose from the fibrous tract connecting Reichert's cartilage to the mandibular angle; found in one case. In all cases (2 sides), the styloglossus muscle was innervated by the hypoglossal nerve. Relationships between the styloglossus muscle and vasculonervous elements of the prestyloid and retrostyloid spaces were analysed.     

人胚胎脑海马发育的形态学研究

本文采用形态学光镜技术对不同胎龄组（４－１０月，每组５例）水囊引产胎儿的海马中段神经细胞的发育状况进行了观察、测量和统计分析。结果显示：锥体层神经细胞密度随胎龄增长呈非直线型下降，尤以６月龄组下降最为明显；锥体层神经细胞的体积随胎龄增长而呈非直线性增加，尤以８月胎龄组增长最为明显；锥体层胶质细胞密度随胎龄增长也呈上升趋势，增加最快的为６月胎龄组。经分析认为随胎龄增长神经胶质细胞密度的变化与锥体层神经细胞密度的变化呈负相关性     

功能性下颌偏斜青春期模型大鼠髁突软骨中血管内皮细胞生长因子的表达

背景：对于功能性下颌偏斜是否会导致骨性的下颌偏斜以及发生功能性下颌偏斜后下颌骨的生长方式是否会发生改变,目前尚存在争议。血管内皮细胞生长因子能够使内皮细胞的渗透性增加、刺激血管内皮细胞的有丝分裂、促进血管生成以及调节骨的形成。 目的：探索大鼠功能性下颌偏斜对其髁突软骨中血管内皮细胞生长因子表达的影响及意义。 方法：选4周龄雄性SD大鼠60只,随机分为对照组(n=20)和实验组(n=40)。实验组大鼠佩戴作者所在课题组自制镍铬合金上前牙冠套,使下颌发生功能性左偏(2.1±0.3) mm,模拟功能性下颌偏斜。 结果与结论：造模后7-28 d功能性下颌偏斜模型大鼠髁突软骨矢状向后部区域偏斜侧血管内皮细胞生长因子的阳性细胞数量较非偏斜侧减少;造模后14-28 d功能性下颌偏斜模型大鼠髁突软骨矢状向中部及冠状向中部区域偏斜侧血管内皮细胞生长因子的阳性细胞数量较非偏斜侧减少,但与对照组接近;造模后14-28 d功能性下颌偏斜模型大鼠髁突软骨冠状向外部区域偏斜侧血管内皮细胞生长因子的阳性细胞数量较非偏斜侧和对照组减少。说明青春期大鼠发生功能性的下颌偏斜后,双侧髁突软骨中的血管内皮细胞生长因子表达存在差异,导致软骨内的成骨活动发生变化,进而可能使大鼠下颌骨的正常生长发育受到影响,提示应尽早矫治功能性下颌偏斜。     

人胎中后期腭扁桃体组织结构特征及其CD20和CD3阳性细胞的表达

目的从形态学角度探讨人胎中后期腭扁桃体组织结构特征及其CD20和CD3阳性细胞的表达情况。方法收集6～10月龄因故终止妊娠人胎腭扁桃体25例,用组织学常规H-E染色显示其组织结构,免疫组织化学SP法染色显示阳性细胞并用BioMiaspro图象分析软件计数。结果自6月龄起,人胎早期形成的腭扁桃体雏形逐渐完善,固有层增厚,弥散淋巴组织和初级淋巴小结增多,已有大量淋巴细胞表达CD20或CD3。至8月龄起,腭扁桃体隐窝上皮内始见毛细血管浸润。邻片对照显示,CD20阳性细不仅大量分布于淋巴小结,且在弥散淋巴组织和隐窝上皮内也较多;CD3阳性细胞则主要分布于弥散淋巴组织,淋巴小结和隐窝上皮内皆较少。细胞计数显示6～10月龄人胎腭扁桃体,2种阳性细胞数量随胎龄增加逐渐增多(P<0.05),但CD20阳性细胞占绝大多数(P<0.05)。结论 8月龄起,人胎腭扁桃体形态结构基本成熟;人胎腭扁桃体具有潜在的CD20和CD3合成和释放能力,对胎儿免疫功能的建立和健全发挥着重要作用。     

The typology of the human fetal lanugo on the thorax

The aim of this work is the systematic study of the skin pilosity pattern on the human trunk during the prenatal period. The course of the lanugo streams and the frequency of the occurrence of the lanugo whorls on the anterior and posterior wall of the thorax are studied on the material of 309 fetuses (163 male and 146 female). The gestational age ranged from 140 to 196 days postconception. The main four whorl types (variations) on the anterior wall and three whorl types on the posterior wall are defined. It is proved that "the cross pattern" is the dominant pattern on the anterior wall (freq. 52.9%). Less frequent variations are "the cross pattern with thoracic whorls" (freq. 15.7%) and "the cross pattern with abdominal whorls" (freq. 22.9%). The rare variation is "the whorl pattern". A few subtypes can be differentiated from each variation. On the other hand, on the posterior wall "the vertebral column path" pattern is the typical pattern (freq. 69.9%). As a runner-up with frequency of 25.8% is "the single whorl pattern". "The multiwhorl pattern" is the rare variation (freq. 4.3%). A few subtypes are separated from each variation.     

The carotid body and arousal in the fetus and neonate

Arousal from sleep is a major defense mechanism in infants against hypoxia and/or hypercapnia. Arousal failure may be an important contributor to SIDS. Areas of the brainstem that have been found to be abnormal in a majority of SIDS infants are involved in the arousal process. Arousal is sleep state dependent, being depressed during AS in most mammals, but depressed during QS in human infants. Repeated exposure to hypoxia causes a progressive blunting of arousal that may involve medullary raphe GABAergic mechanisms. Whereas CB chemoreceptors contribute heavily to arousal in response to hypoxia, serotonergic central chemoreceptors have been implicated in the arousal response to CO₂. Pulmonary or chest wall mechanoreceptors also contribute to arousal in proportion to the ventilatory response and decreases in their input may contribute to depressed arousal during AS. Little is known about specific arousal pathways beyond the NTS. Whether CB chemoreceptor stimulation directly stimulates arousal centers or whether this is done indirectly through respiratory networks remains unknown. This review will focus on arousal in response to hypoxia and CO₂ in the fetus and newborn and will outline what we know (and do not know) about the involvement of the carotid body in this process.