6.5-mm human embryo with a single nasal placode: cyclopia or hypotelorism?

A macroscopic study on the missing elements in cyclopia (a single eye or closely approximated eyes with all intergrades in a single orbit) with or without proboscis and hypotelorism was performed on 12 human fetuses and 2 human fetal skulls. In addition, microscopic investigations were carried out on the orbital contents of the cyclops with a single eye without proboscis, crown-heel length (C-HL) 37 cm, and on the 6.5-mm-crown-rump length (C-RL) human embryo with a single nasal placode localized in front of two eye cups. In the embryo and in all 14 fetal cases the midfacial region was more-or-less deficient. In the two cyclopia cases without proboscis the nasal placode(s) had not developed at all during the embryonic period. In cases with proboscis, consisting of a single tube localized above both eyes, and in the hypotelorismic specimens, there could only have been a single nasal placode during development: a situation evident in the 6.5-mm-C-RL human embryo. In this holoprosencephalic embryo the single nasal placode was undulated, as if formed from two fused nasal placodes, and flanked by the prospective areas for the lateral nasal processes. Caudally, it was bordered by the maxillary processes. In view of the position of the single placode in this embryonic face, as described above, it is most likely that this is a preliminary stage of hypotelorism. Moreover, both medial nasal processes with the internasal groove in between, i.e., the interplacodal area, were missing.(ABSTRACT TRUNCATED AT 250 WORDS)     

浙江枝吻纽虫吻的形态学研究

采用组织学、电镜技术等手段对浙江枝吻纽虫吻的生物学特性进行了研究,阐述浙江枝吻纽虫吻的结构与其他分枝纽虫吻的组织结构异同.研究结果表明,浙江枝吻纽虫吻为一条长的肌肉组织的管道结构,一端连着头部组织,一端延伸在一个封闭的空腔中.吻腔环肌层与体壁环肌层没有交叉点,但是吻腔壁背面的环肌与体壁背面的环肌通过一束肌肉而交织在一起.在吻壁处富含大量的分泌细胞和神经细胞.当吻离体后,在普通海水中伸缩能维持 2~4 h.     

A new genus and species of heteronemertean from the Changjiang (Yangtze) River Estuary

A new genus and species of heteronemertean, Yinia pratensis gen. nov. and sp. nov., collected from low salinity waters (salinity 0.2–0.4 ‰) at Changjiang River Estuary, is described and illustrated. The species possesses a proboscis with an outer circular and an inner longitudinal muscle layer, and is placed in family Lineidae sensu Gibson. The following combination of morphological features distinguishes the new species from any other genera in this family: proboscis with two muscle crosses; dermis without connective tissue layer between gland cells and body wall outer longitudinal muscle layer; rhynchocoel wall circular muscles not interweaving with adjacent body wall longitudinal muscles; foregut with circular somatic muscles and subepithelial gland cell layer; neurochord cells present in central nervous system; caudal cirrus missing; blood system developed into alimentary plexus extending almost the full length of the body. Another significant character is that the lobular excretory cells are extremely well developed which may represent adaptation to water of low salinity. This revised version was published online in July 2006 with corrections to the Cover Date.     

Olfactory ensheathing cells: their role in central nervous system repair

The olfactory system is an unusual tissue in that it can support neurogenesis throughout life; permitting the in-growth and synapse formation of olfactory receptor axons into the central nervous system (CNS) environment of the olfactory bulb. It is thought that this unusual property is in part due to the olfactory glial cells, termed olfactory ensheathing cells (OECs), but also due to neuronal stem cells. These glial cells originate from the olfactory placode and possess many properties in common with the glial cells from the peripheral nervous system (PNS), Schwann cells. Recent data has suggested that olfactory ensheathing cells are a distinct glial cell type and possess properties, which might make them more suitable for transplant-mediated repair of central nervous system injury models. This paper reviews the biological properties of these cells and illustrates their use in central nervous system repair.     

Palatine bone in human cyclopia

In human cyclopia, a maxillopalatine mass separates the median orbit from the oral cavity. The palatine component of this bony mass has been studied in serial sections through the median third of the head in three perinatal human specimens presenting with a median orbit and proboscis. One head was sectioned in the sagittal plane and two in the coronal plane. The course of each neurovascular bundle arising from the maxillary artery and nerve was used to facilitate the identification of the various parts of the palatine bone. The data obtained were used to outline the palatine component of the maxillopalatine mass as it presented on the inferior aspect of a dried cyclops skull. The suggestion is made that the abnormalities of the palatine bone in human cyclopia are secondary to the absence of the presphenoid and the nasal cavity.     

Vascularized rib for facial reconstruction

The reconstruction of maxillectomy defects is a complex problem encountered in plastic surgery. Defects can range in size and complexity from small defects requiring only soft tissue to complete maxillectomies requiring large tissue bulk, bone, and one or more skin paddles. The most difficult defects involve the skull base and orbit. The reconstructive surgeon is faced with the challenge of isolating the nasopharynx from the dura and globe while simultaneously restoring the bony framework of the maxilla and orbit to support the soft tissue of the cheek. The authors present a series of six reconstructions using a rectus abdominis muscle flap with associated vascularized rib for reconstruction of complex maxillectomy defects. This flap provides large soft-tissue bulk as well as bony support and a long vascular pedicle. A skin island can be taken with the flap, and the donor-site morbidity is comparable to that seen with a vertical rectus abdominis myocutaneous flap. Six flaps were used in five patients over a 20-month period. All patients had stable support of the orbit at follow-up with adequate soft-tissue coverage, and there were no incidences of visual changes.     

Oesophageal peristalsis in the cat: the role of central innervation assessed by transient vagal blockade

Studies were performed on five cats to assess the role of extrinsic vagal innervation in the control of peristalsis in the smooth muscle oesophagus. Transient vagal nerve blockade was accomplished by cooling the cervical vagosympathetic nerve trunks previously isolated in skin loops on each side of the neck. Peristalsis throughout the body of the oesophagus was monitored using a continuously perfused multilumen manometry tube. Striated and smooth muscle portions of the esophagus were delineated by abolishing smooth muscle activity with atropine. Secondary peristalsis was assessed by intra-oesophageal balloon distension studies. The threshold volume for balloon-induced secondary peristalsis was lower in the smooth muscle oesophagus. Unilateral vagal blockade reduced the incidence of primary and secondary peristalsis in the striated muscle oesophagus but not in the smooth muscle oesophagus. Bilateral vagal nerve blockade abolished primary swallow-induced peristalsis and secondary peristalsis in both the smooth and striated muscle cat oesophagus. Administration of cholinergic agents or adrenergic blocking agents failed to restore secondary peristalsis in the smooth muscle oesophagus during vagal cooling. We conclude that connections to the central nervous system via the vagal nerve trunks are required for normal secondary as well as primary peristalsis in both the smooth and striated muscle portions of the cat oesophagus.     

Immunohistochemical evidence of ubiquitous distribution of the metalloendoprotease insulin-degrading enzyme (IDE; insulysin) in human non-malignant tissues and tumor cell lines

Immunohistochemical evidence of ubiquitous distribution of the metalloprotease insulin-degrading enzyme (IDE; insulysin) in human non-malignant tissues and tumor cells is presented. Immunohistochemical staining was performed on a multi-organ tissue microarray (pancreas, lung, kidney, central/peripheral nervous system, liver, breast, placenta, myocardium, striated muscle, bone marrow, thymus, and spleen) and on a cell microarray of 31 tumor cell lines of different origin, as well as trophoblast cells and normal blood lymphocytes and granulocytes. IDE protein was expressed in all the tissues assessed and all the tumor cell lines except for Raji and HL-60. Trophoblast cells and granulocytes, but not normal lymphocytes, were also IDE-positive.     

Morphology of the proboscis of Hubrechtella Juliae (nemertea,pilidiophora): Implications for pilidiophoran monophyly

The proboscis of Hubrechtella juliae was examined using transmission electron microscopy, scanning electron microscopy, and confocal laser scanning microscopy to reveal more features of basal pilidiophoran nemerteans for morphological and phylogenetic analysis. The proboscis glandular epithelium consists of sensory cells and four types of gland cells (granular, bacillary, mucoid, and pseudocnidae‐containing cells) that are not associated with any glandular systems; rod‐shaped pseudocnidae are 15–25 μm in length; the central cilium of the sensory cells is enclosed by two rings of microvilli. The nervous plexus lies in the basal part of glandular epithelium and includes 26–33 (11–12 in juvenile) irregularly anastomosing nerve trunks. The proboscis musculature includes four layers: endothelial circular, inner diagonal, longitudinal, and outer diagonal; inner and outer diagonal muscles consist of noncrossing fibers; in juvenile specimen, the proboscis longitudinal musculature is divided into 7–8 bands. The endothelium consists of apically situated support cells with rudimentary cilia and subapical myocytes. Unique features of Hubrechtella's proboscis include: acentric filaments of the pseudocnidae; absence of tonofilament‐containing support cells; two rings of microvilli around the central cilium of sensory cells; the occurrence of subendothelial diagonal muscles and the lack of an outer diagonal musculature (both states were known only in Baseodiscus species). The significance of these characters for nemertean taxonomy and phylogeny is discussed. The proboscis musculature in H. juliae and most heteronemerteans is bilaterally arranged, which can be considered a possible synapomorphy of Hubrechtellidae + Heteronemertea (= Pilidiophora). J. Morphol. 274:1397–1414, 2013. © 2013 Wiley Periodicals, Inc.     

Tissue amino acid pool changes during the perinatal period of the rat

Total free amino acid content in foetal liver, kidney, skin and striated muscle increases sharply during pregnancy. After delivery, there is no significant change in tissue total amino acid pools. The essential free amino acid pool in striated muscle decreases after delivery. This decrease suggests a relationship with the increased protein content in striated muscle.     

Ultrastructure and electrical properties of the hyperneural muscle of Periplaneta americana

The hyperneural muscle of Periplaneta americana is striated with an A-band at least 2 μm long. Z-bands were discrete units, but arranged with some order in the myoplasm. The sarcoplasmic reticulum was reduced and 1 thick was surrounded by 10 to 12 thin myofilaments. The muscle is innervated from the median nerves by axons containing electron-dense granules which may be opaque near the neuromuscular junction amid numerous synaptic vesicles. Depolarizing intracellular current injection produces an ohmic voltage response of the membrane potential and neurally evoked contraction is effected by summated excitatory postsynaptic potentials. All contractal activity ceases when the innervation is removed. The muscle appears to be electrically inexcitable and to be under obligatory control of central motor units. By virtue of attachments along the ventral nerve cord in the abdomen, the hyperneural muscle, when activated, moves the nerve cord unidirectionally. In effect, the hyperneural muscle is called upon by the central nervous system to move the ventral nerve cord presumably into a greater mix with the haemolymph in response to as yet unknown stimuli.     

Heart structure and beat in the stable fly, Stomoxys calcitrans

ABSTRACT. The heart of the adult stable fly, Stomoxys calcitrans (L.), is suspended from the dorsal sclerites of the abdomen by strands of connective tissue, and supported from below by alary muscles that insert into a central band of longitudinal muscle just beneath the aorta. Valved openings occur in three of the heart segments. The central band of muscle beneath the heart is innervated but there is no well-defined lateral cardiac nervous system. The myocardium consists of a single layer of circular muscle composed of a series of muscle fibres that are joined dorsally and ventrally by intercalated discs in the midline of the insect. T-system tubules are closely associated with the sarcoplasmic reticulum, forming dyads. The heart rate of intact stable flies varied from short intervals of almost no activity to periods with a very rapid beat (126–294 pulses/min), and when the connections to the central nervous system were severed the heart beat became very regular (258 pulses/min). Slight pressure applied to the dorsal septum stopped myocardial contractions in that segment. The myocardium was insensitive to perfusion with 10^-3M acetylcholine, l -aspartic acid, l -glutamic acid, Λ-aminobutyric acid, 5-hydroxytryptamine, octopamine, tyramine and proctolin 10^-5 m. However, Mn⁺⁺ caused either an intermittent beat at lower concentrations (0.5 min) or near arrest at higher concentrations (2 mM).     

The differentiation of cytotoxic T lymphocytes in vitro

Summary Previous neurohistological studies have been extended to include the structures contained solely or mainly within the junctional esophageal segment which may play an important role in the sphincter mechanism. The main findings were: 1) a progressive cranio-caudal thickening of the muscularis mucosae; 2) a conspicuous thickening of the circular muscle layer; 3) abundant and close interconnections between the esophageal striated fibres and gastric smooth muscle cells; 4) presence of annulo-spiral elastic fibres coiled around bundles of striated musculature; 5) increase of the intramural nerve component, particularly Auerbach's plexus, which consisted of a continuous nervous layer containing twice as many neurocytes as found in the upper esophageal segments; 6) presence of numerous interconnected motor endplates often possessing ultraexpansional fibres and secondary endplates. The findings are discussed with emphasis on functional correlations in order to attain a unitary morpho-functional view.Abbreviations used LES lower esophageal sphincter - HPZ high pressure zone; mm: muscularis mucosae - CNS central nervous system - CCK-PZ cholecystokinin-pancreozymin Dedicated to Prof. Dr. Wolfgang Bargmann for his fundamental contributions to Comparative Morphology     

Immunohistochemical distribution of CD9, heparin binding epidermal growth factor-like growth factor, and integrin alpha3beta1 in normal human tissues.

The tetra-membrane-spanning protein CD9 forms a complex with a membrane-anchored heparin binding epidermal growth factor-like growth factor (HB-EGF) and integrin alpha3beta1 in some human and monkey cell lines. We show here the immunohistochemical distribution of CD9, HB-EGF, and integrin alpha3beta1 in normal human tissues. Distribution of CD9, HB-EGF, and integrin alpha3beta1 was similar in various tissues, including transitional epithelium, squamous epithelium, thyroid follicular epithelium, adrenal cortex, testis, smooth muscle, and stromal fibrous tissue. However, distribution of the three proteins did not coincide in some tissues, such as lung, liver, kidney, gastric and intestinal epithelium, pancreas, salivary gland, and ovary. In striated muscle, including cardiac muscle, CD9 was present not in the muscle cells themselves but in the endomysium and perimysium, whereas HB-EGF was distributed in the muscle cells themselves. CD9 was distributed in the myelin, but HB-EGF was found in the axon of the peripheral and central nervous systems. Coincident distribution of integrin alpha3beta1 with others was not observed in muscles and neural tissues. In conclusion, there is a possibility of complex formation and functional cooperation of CD9 with HB-EGF and/or integrin alpha3beta1 in several tissues.     

Disruption of the olfactory placode and brain conditioned medium increase the number of LHRH immunostained neurons in explants

The olfactory placode gives rise to both olfactory receptor neurons, which remain as a component of the peripheral nervous system, and to luteinizing hormone-releasing hormone (LHRH) neurons, which migrate to the central nervous system. In this study, we used chick olfactory placode explants to ask several questions regarding LHRH neuronal differentiation. We found that explants of ectoderm from the fronto-nasal region of embryos as early as Hamilton & Hamburger (HH) stage 12 gave rise to LHRH neurons, that explants from all regions of the olfactory placode were able to generate LHRH neurons, that both brain conditioned medium and disruption of the olfactory placode increase the number of LHRH neurons observed in explants, and that the combination of these two manipulations results in the production of more LHRH neurons than either treatment alone. We conclude that LHRH neurons originate in the olfactory epithelium and that some of the same factors which influence olfactory receptor neuron development also affect LHRH neuronal development.     

The structure of the proboscis musculature in <Emphasis Type="Italic">Baseodiscus delineatus</Emphasis> (Delle Chiaje, 1825) (Heteronemertea) and the comparative analysis of the proboscis musculature in heteronemerteans

The proboscis musculature was studied in the nemertean Baseodiscus delineatus using confocal laser scanning and electron transmission microscopy. Three muscle layers were differentiated in the proboscis wall: the outer-longitudinal, the diagonal, and the inner-circular layer. The endothelium consists of two cell types: apical supportive cells with rudimentary cilia and subapical myocytes making up the inner-circular musculature of the proboscis. The supportive cells have thin processes attached to the basal extracellular matrix and their perikarya are spread over the apical surfaces of myocytes. The endothelium of B. delineatus is characterized by a folded basal layer of the extracellular matrix and by different heights of myocyte processes, giving an impression that the inner-circular musculature is multilayered. Comparative analysis shows that the diagonal musculature of Baseodiscus is not homologous to that of other heteronemerteans. An assumption is made that the inner-circular muscles have endothelial origin in all heteronemerteans.     

Functional morphology of the Conus proboscis (Mollusca: Gastropoda)

The extended proboscis of the toxoglossan gastropod Conus may exceed four times its contracted length and 1.5 times the shell length. The proboscis wall consists of cuboidal epidermis and circular, crossed helical and longitudinal muscle layers. Between the proboscis wall and its lumen, free longitudinal muscles and nerves course through haemocoel. A thick layer of connective tissue and columnar epithelium surround the proboscis lumen. In C. Catus , muscle comprises about 70% of the volume of the proboscis (exclusive of its lumen) and haemocoel about 20%, in both moderately extended and contracted states. Differentiation along the length of the proboscis includes gradual replacement of muscle by connective tissue distally in the proboscis wall, and a subapical sphincter muscle that probably prevents back-slippage of the detached radular tooth prior to its use in feeding and aids injection of the tooth into the prey during capture.     

Surgical reconstruction of the contracted orbit

Anophthalmic patients and patients afflicted with retinoblastoma incur severe deformity of the orbit. Treatment of the severely contracted orbit is very difficult, and patient satisfaction is often poor. Since 1988, we have performed temporalis muscle transfer and surgical expansion of the contracted bony orbit in 26 patients. Satisfactory results were obtained. Gradual expansion of the orbit was performed in case of congenital anophthalmic patients. The treatment should be established in multiplicity, among many methods available for contracted eye sockets, according to the degree of orbital deformity and the amount of residual conjunctiva. In case of severe deformity, volume expansion surgery and temporalis muscle transfer are necessary. If augmentation is required in the periorbital region, rib bone onlay graft must be performed. We were able to shorten the operative time by modifying the three-wall orbital expansion technique of Tessier and Wolfe to a more simplified method. Our observations show that our procedures achieved symmetry in both eyes in all patients, and there have been no remarkable complications.