肾小球疾病HLA易感基因研究报告

目的：探讨肾小球疾病发生及发展与HLA等位基因的关系，寻找肾小球疾病HLA易感基因。方法：采用序列特异性引物-聚合酶链反应方法对肾小球疾病患儿的HLA等位基因进行分析，并分析了肾小球疾病患儿存在HLADRB1^*15的不同临床表现。结果：肾小球疾病患儿HLADRB1^*15基因频率为16.25％，明显高于正常对照组；HLADRB1^*15基因在肾病综合征和急性肾小球肾炎患儿中的分布无明显差异；HLADRB1^*15型急性肾小球肾炎和肾病综合征患儿临床症状表现重。结论：肾小球疾病的发生、发展与HLA基因型有关；探讨肾小球疾病的HLA基因型对于判断病情有重要意义。     

The neuroanatomical basis for the protopathic sensibility of the human glans penis

The human glans penis is covered by stratified squamous epithelium and a dense layer of connective tissue equivalent to the dermis of typical skin. Rete ridges of the epidermis are irregular and vary in height depending on location, age, and presence or absence of a foreskin. The papillary layer of the dermis blends into and is continuous with the dense connective tissue forming the tunica albuginea of the corpus spongiosum of the glans penis. The most numerous nerve terminals are free nerve endings (FNEs) present in almost every dermal papilla, as well as scattered throughout the deeper dermis. FNEs are characterized by an incomplete Schwann cell investment, and contain irregularly scattered neurofilaments and neurotubules, clusters of mitochondria, vesicles of variable size and various inclusions. The ratio of FNEs to corpuscular receptors is approximately 10:1 and a similar ratio of small to large axons is seen in dermal nerves. Genital end bulbs are present throughout the glans, but are most numerous in the corona and near the frenulum. The unique corpuscular receptor of the glans penis consists of axon terminals that at an ultrastructural level resemble a tangled skein of FNEs. Simple, Pacinian and Ruffini corpuscles were occasionally identified predominantly in the corona glandis. Epidermal Merkel nerve endings and other types of mechanoreceptors typically found in primate glabrous skin (lip or digit) are not present. Rarely, dermal Merkel cells have been identified associated with genital end bulbs. The abundance of FNEs in isolated as well as corpuscular form can be correlated with the embryogenesis and known neurophysiologic and psychophysical parameters of sensory function of the glans penis. Finally, the divergence in reported values for the threshold of tactile and painful stimuli when applied to glabrous skin of fingertip and glans penis can be considered as an example of dissociated sensibility. The anatomical basis for this dissociation is the abundance of FNEs and absence of Merkel terminals and typical Meissner corpuscles in the covering of the glans, and the converse in glabrous skin of the digit.     

The innervation of the primate fungiform papilla — development, distribution and changes following selective ablation

The development of the terminal parts of the chorda tympani nerve, lingual nerve and cranial sympathetics in the macaque fungiform papillae were studied by light- and electron microscopy. Their respective distributions in the intra- and extragemmal compartments of papillae from adult macaques were examined following selective ablation of each nerve.Prior to midgestation, a single bundle of unmyelinated axons which contained numerous axoaxonic synapses passed through the subepithelial connective tissue and ramified in the single nascent chemosensory corpuscle and surrounding non-gustatory epithelium. Following midgestation

1. (1), additional chemosensory corpuscles appeared, possibly by division of existing corpuscles,

2. (2) myelination of axons was begun,

3. (3) axoaxonic synapses were eliminated, and

4. (4) nerve terminals appeared in the subepithelial connective tissue as free nerve endings and coiled simple nerve endings. In the perinatal period, coiled simple endings, corpuscular receptors and Meissner corpuscles were present in the papilla core. Large numbers of intra-epithelial nerve endings were present in the extragemmal epithelium throughout development. Tonofilament collars ensheathed intra-epithelial axons and 80–100 nm dense core granules, occupying adjacent epithelial cells, appeared to be sequestered near such axons.

Experimental selective ablation indicated that the terminal parts of chorda tympani fibers were present only within chemosensory corpuscles. In contrast, lingual nerve endings were present both in the extragemmal epithelium and chemosensory corpuscles and also were the sole supply of corpuscular receptors. Sympathetics appeared to be sparsely distributed in the papilla core.Intra-epithelial axons degenerated within 24 h following transection, while axons with Schwann or lamellar cell sheaths or myelin persisted for at least 3 days.     

人胎儿手,脚皮内环层小体的分布与结构观察

对77例受精龄为12～38周人胎儿手、脚皮内环层小体的分布与结构,进行显微测量和光镜观察。发现在手、脚皮内的不同部位,环层小体的出现时间和发育程度都不同。出现较早的是在第12周龄拇指、食指、无名指与小指的真皮深层内。刚出现时形态较小,结构简单。随着胎龄的增长,分布部位逐渐扩大,形态变大。发育程度不同的环层小体常共存于一个胎龄期的同一部位。最后对环层小体的发生进行了讨论。     

Vibration sensitivity as a parameter for detecting peripheral neuropathy

Summary Two methods of evaluating the threshold for vibration perception were compared. Surprisingly it appears that the theoretically attractive, adaptive forced choice method does not result in lower variability than the method of limits. Moreover two devices were used to evaluate the threshold: the Optacon Tactile Tester and the multirod. Based on the characteristics of these devices and the known properties of mechanoreceptors, it is argued that the two devices test different mechanoreceptor systems. The high correlation of threshold with age (r = 0.9) found by Arezzo and Schaumburg [1] in measurements with the Optacon could not be reproduced.     

Origin of spinal cord meninges, sheaths of peripheral nerves, and cutaneous receptors including Merkel cells

Summary The origin of cells covering the nervous system and the cutaneous receptors was studied using the quail-chick marking technique and light and electron microscopy. In the first experimental series the brachial neural tube of the quail was grafted in place of a corresponding neural tube segment of the chick embryo at HH-stages 10 to 14. In the second series the leg bud of quail embryos at HH-stages 18–20 was grafted in place of the leg bud of the chick embryos of the same stages and vice versa. It was found that all meningeal layers of the spinal cord, the perineurium and the endoneurium of peripheral nerves, as well as the capsular and inner space cells of Herbst sensory corpuscles, develop from the local mesenchymal cells. Schwann cells and cells of the inner core of sensory corpuscles are of neural crest origin. The precursors of Merkel cells migrate similarly to the Schwann cells into the limb bud where they later differentiate. This means that in addition to the Schwann cells and the melanocytes a further neural crest-derived subpopulation of cells enters the limb.     

Sensory nerve endings in the hard palate and papilla incisiva of the rhesus monkey

 The sensory innervation of the hard palate of the rhesus monkey was studied by light and electron microscopy. The mucosa of the hard palate is subject to a particularly heavy mechanical load requiring functional specialisation of the horny epithelium in the form of thickenings – the papilla incisiva and eight pairs of rugae palatinae. A thin layer of firm connective tissue (lamina propria) attaches the mucosa to the periost of the hard palate. Sensory nerve fibres were found most abundantly in the papilla incisiva and first rugae palatinae. Their number decreases in an aboral direction. Five types of sensory nerve endings were found. Free nerve endings were ubiquitous in the epithelium and lamina propria. Merkel nerve endings were found in the basal layer of the epithelium of the papilla incisiva and rugae palatinae. Meissner corpuscles were located in the connective tissue between epithelial pegs, while lamellated corpuscles were seen below the epithelial pegs. Ruffini corpuscles were found in the deeper layer of the lamina propria. Thus, a variety of sensory nerve endings were found in the hard palate, especially in those areas that are in close contact with the tongue during chewing of food. This rich innervation suggests an important role in monitoring the mechanical properties of food and the position of the tongue. Accepted: 30 September 1998     

Localization of HIV-1 in human thymic implant in SCID-hu mice after intravenous inoculation

Human immunodeficiency virus type 1 (HIV-1) was immunohistochemically and ultrastructurally localized in human thymus implants in SCID-hu mice 3 weeks after intravenous (i.v.) inoculation of the virus. A viral antigen (gp120) was predominantly distributed in and around the epithelial cells in Hassall's corpuscles as demonstrated by fluorescence immunohistochemistry. Occasional solitary round cells positive for the viral antigen but negative for cytokeratin were detected in the perivascular areas. Ultrastructural examinations clearly revealed a number of mature viral particles in the intercellular spaces of the Hassall's corpuscles. Thus the present study indicates the possibility that thymic epithelial cells in Hassall's corpuscles act as a target and/or reservoir in an early stage of HIV infection.     

Sensory nerve endings in the beak skin of Japanese quail

Summary This study is concerned with the distribution and ultrastructure of sensory nerve endings in the beak skin of adult Japanese quail (Coturnix coturnix japonica). The following nerve endings were found: free nerve endings, clusters of dermal Merkel nerve endings, Herbst corpuscles and Ruffmi corpuscles. The latter were found only in the dermis of the tip of the upper beak. The remaining endings were present in the skin of all areas of upper and lower beak. Free nerve endings were supplied by either thin myelinated axons or unmyelinated C-fibers and were localized in the dermis close to the basal layer of the epidermis. Merkel cells formed clusters (up to 50) localized below and between the epidermal cones of the beak skin. Disc-shaped thickenings of nerve endings were squeezed between individual Merkel cells. Small Herbst corpuscles were found in the dermis close to the epidermal cones of the beak skin. Large Herbst corpuscles occurred in deep layers of the dermis. The Ruffmi corpuscles were cylindrical in shape (80 m × 400 m) and arranged in groups of up to ten corpuscles. Each corpuscle was surrounded by an incomplete fibrous capsule.     

High-Resolution Ultrasound Visualization of Pacinian Corpuscles

The aim of this study was to evaluate the possibility of visualizing Pacinian corpuscles in the palm of the hand with high-resolution ultrasound (HRUS). In this prospective study, HRUS with a high-frequency probe (22 MHz) was used. The palms of two fresh cadaveric hands were screened for potential Pacinian corpuscles. Still ultrasound images and dynamic video sequences were obtained. In five regions with large amounts of suspected Pacinian corpuscles, tissue blocks were excised and histologically processed, and corresponding slices were compared with ultrasound images. Further, the transverse diameters of five Pacinian corpuscles, at the level of the metacarpal heads in the palm, were assessed on both sides (in total 100) in healthy volunteers. On ultrasound, Pacinian corpuscles presented as echolucent dots in the subcutis, adjacent to digital nerves and vessels and located 2–3 mm beneath the surface. On histologic sections, these echolucent dots corresponded to Pacinian corpuscles with respect to their position and topographic relationships. The mean transverse diameter for all volunteers was 1.40 ± 0.23 mm (range: 0.8–2.2 mm). This study confirms the ability to reliably visualize Pacinian corpuscles with HRUS, which contributes to our basic understanding of ultrasonographically visible subcutaneous structures and may enhance the diagnosis of pathologies related to Pacinian corpuscles.