The secondary tongue of Salamandra salamandra: histochemical and ultrastructural aspects of the developing lingual epithelium

The development of the lingual epithelium of Salamandra salamandra was investigated with emphasis on histochemical and ultrastructural aspects. The temporal and spatial occurrence and the typical appearance of various cell types; i.e. pavement cells, replacement pavement cells, basal cells, mitochondria rich cells, goblet cells and glandular cells have been analysed and documented in detail from the young larval stage up to the metamorphosed animal (2 months after metamorphosis). It is shown that anatomical re- and de novo-constructions related to the formation of the secretory tongue led to distinct changes in the cellular equipment of the epithelium of the tongue, including various histochemical properties. Finally, functional aspects of the morphological characteristics are discussed in detail and compared with respective findings in other species.     

Pronephric regression during larval life in the sea lamprey, Petromyzon marinus L.

Summary The regression of the pronephric kidney of the lamprey, Petromyzon marinus, is described using histochemical and ultrastructural techniques. Regression begins in the third year of larval life, and by the time the animal enters metamorphosis the tubules have all disappeared. The nephrostomes and the renal corpuscle, however, persist for the remainder of the life cycle and undergo little change in the larva. Iron is present within the tubular epithelium prior to the beginning of degeneration, but as degeneration proceeds iron is observed within the tubule lumina. Acid phosphatase is noted within the tubule epithelia prior to degeneration, but as degeneration proceeds acid phosphatase is also observed within the intertubular area. Features of tubular regression include a prominent and highly folded basal lamina, numerous cytoplasmic inclusions, and dense bodies in the epithelia and lumina. The intertubular region is invaded by lymphocytes, granulocytes, plasma cells, and macrophages. The process of pronephric regression possesses many features of the process of apoptosis, which has been noted in the regression of larval organs in other vertebrates.     

Effects of puromycin on chick embryo lung development in vitro

Summary Effects of puromycin on chick embryo lung differentiation in vitro has been studied.Lung morphogenesis stops as a result of wide, deep and specific damages of mesenchymal cells, produced by inhibitor administration. Treated cultures, when transferred into normal nutrient medium, exhibit a certain recovery.We can conclude that 1) lung morphogenesis is dependent upon mesenchymal cell metabolism and that 2) the inductive activity takes place for a certain period of incubation.     

TrkB is necessary for the normal development of the lung

Normal development of the lung requires coordinated activation of cascades of signaling pathways initiated by growth factors signaling through their receptors. TrkB and its ligands, brain-derived neurotrophic factor (BDNF) and neurotrophin-4, belong to the neurotrophin family of growth factors, which are expressed in a large variety of non-neuronal tissues including the lung. Aberrant neurotrophin signaling underlies the pathogenesis of several lung-related pathologies, including asthma and lung cancer, however, little is known about the role of neurotrophins in the embryonic development of the lung. To fill this gap in knowledge, we analyzed the pattern of TrkB expression in the murine lung and we observed that TrkB is expressed in alveolar macrophages, type II pneumocytes, neuroepithelial bodies and nerves. Analysis of the structure of lung from mice deficient in TrkB revealed that absence of TrkB signaling results in thinner bronchial epithelium and apparent larger air space, and, more importantly, lack of neuroepithelial bodies, an important reduction in the density of nerve fibres in the bronchial smooth muscle, submucous plexus in bronchioles, and pulmonary artery walls. These findings suggest TrkB is essential for the normal development of the lung and the nervous system in the lung.     

Development of retinofugal neuropil areas in the brain of the alpine newt, Triturus alpestris

Summary The development of the retinofugal projection areas of the brain has been studied in larvae of Triturus alpestris by means of anterograde transported horseradish peroxidase. The optic tract establishes contacts with the optic tectum prior to the onset of robust terminal formation in the diencephalon. The tectum becomes covered by the retinofugal projection in a rostro-caudal direction. The basal optic neuropil develops synchronously with the oculomotor neurons. Their dendrites extend into this neuropil area. A small amount of uncrossed label occurs long before metamorphosis. Around metamorphotic climax this ipsilateral label increases but does not attain the adult pattern even three months postmetamorphosis. The data are compared with the onset of visual induced behaviour.     

Ontogeny of GABA-immunoreactive neurons in the central nervous system in a teleost, Gasterosteus aculeatus L.

The inhibitory neurotransmitter γ-aminobutyric acid (GABA) is known to exert various neurotrophic actions in the developing nervous system, but little is known about its distribution in the central nervous system during early development. We have studied the development of GABA-immunoreactive (GABAir) neurons during embryogenesis of a teleost fish, the three-spined stickleback. As early as 51 h postfertilization (PF; hatching occurs 144–168 h PF, and the first monoaminergic neurons appear around 72 h PF) GABAir neurons appear in the ventral prosencephalon caudal to the optic recess, in the ventral meencephalon, and in the spinal cord. Then, there is a gradual addition of GABAir cell groups in the rostral prosencephalon and ventral rhombencephalon (66 h PF), dorsal and caudal hypothalamus and pretecturn (72 h PF), ventral hypothalamus (78 h PF), preoptic region, thalamus, and in the meencephalon and rhombencephalon (96 h PF). GABAir axons appear in the spinal cord already at 51 h PF, and then gradually appear in the various tracts of the early axonal scaffold of pathfinding fibers, so that by 96 h PF the entire axonal scaffold contains GABAir fibers. It appears likely that GABAergic axons contribute a major population to the formation of the axonal scaffold. Moreover, in the prosencephalon GABAir neurons are arranged in clusters that may reflect a neuromerec organization with six prosencephalic neuromeres.     

Early organization of the pituitary gland in Sparus aurata L. (Teleostei) An ultrastructural study

The cell organization of the pituitary gland and the relationship between neurohypophysis and adenohypophysis in the early developmental stages of the gilthead sea bream, Sparus aurata, were studied by electron microscopy. In newly hatched larvae, the pituitary gland was embedded in the ventral floor of the diencephalon and separated from the hypothalamus by a continuous basal lamina. Elongated mesenchymal cells next to the ventral surface were observed. At this stage, there was no neurohypophysis and the adenohypophysis consisted of undifferentiated endocrine cells with small scarce secretory granules and a few stellate cells, with no distinctive zonation. An incipient neurohypophysis was present in 1-day-old larvae. The first evagination of the neurohypophysis into the adenohypophysis were observed in 2-day-old larvae and developed progressively with age, being deeper in the caudal zone. Two regions in the adenohypophysis, one anterior — the presumptive pars distalis — and one posterior — the presumptive pars intermedia — were found in 2-day-old larvae. Three regions (rostral and proximal pars distalis and pars intermedia) were clearly distinguishable in 4-day-old larvae. The ultrastructural features of the pituitary endocrine cells varied during gland differentiation, with the secretory granules gradually increasing in number and size, accompanying organelle development. Nevertheless, even in the oldest larvae studied (65 days), undifferentiated cells similar to those in the earliest stages were observed. The first blood vessels appeared in the neurohypophysis around 16 days after hatching. During early development, the pituitary gland progressively emerged from the ventral floor of the brain. By 16 days, the principal pattern of the pituitary gland architecture appeared to be established.     

Development of the hypothalamic vasopressin system and nephrons in Meriones shawi during ontogenesis

This study has evaluated the development of the hypothalamic vasopressin system and nephrons of the kidney in desert rodents, Meriones shawi, which effectively retain water by excretion of highly concentrated urine. The vasopressin system was studied immunocyto chemically at the 18th fetal day, at the 2nd, 13th, 27th postnatal days and in adulthood. The kidneys were investigated at the 2nd, 13th postnatal days and in adulthood using microdissection technique. Occasional vasopressin-immunoreactive neurons were observed as early as the 18th fetal day, only in the paraventricular nucleus. From the 2nd postnatal day onwards, vasopressin neurons increased progressively in number, being mainly concentrated in the supraoptic and paraventricular nuclei, as well as in the ventral retrochiasmatic region. Transient neuronal populations were also observed at the 13th postnatal day in the lateral preoptic area and anterior hypothalamic nucleus. Apart from the neurons, the glandular cells of the tuberal lobe showed immunostaining from the 18th fetal day, the first age studied, until the 13th postnatal day. The fibers of differentiating vasopressin neurons grew towards the circumventricular/neurohemal organs, terminating in the organum vasculosum of the lamina terminalis and the lateral ventricles as early as the 18th fetal day, as well as the third ventricle, the posterior lobe and the external zone of the median eminence between the 2nd and 13th postnatal days. The kidney in 2 day-old Meriones comprised nephrons at different stages of development from an S-shaped body to well-differentiated nephrons. At the 13th postnatal day, as in adulthood, the nephrons were well differentiated and characterized by long, thin loops descending to different levels of papilla. Thus, according to our morphological data the hypothalamic vasopressin neurons and nephrons in the kidney of Meriones reach the definitive state by the end of the 2nd postnatal week.     

长链非编码RNA在肺癌中的研究进展

长链非编码RNA（LncRNA）是一类转录本长度超过200nt的RNA,不编码蛋白,大多数位于细胞核,以RNA的形式在多层面上（表观遗传调控、转录调控以及转录后调控等）调控基因的表达水平。其广泛参与机体的生理和病理过程,在恶性肿瘤的发生和发展中起着重要作用。     

Morphological differentiation of taste organs in the ontogeny of Salamandra salamandra

Morphological studies presented here provide additional cytological evidence that in the postnatal development of Salamandra salamandra there are two successive generations of taste organs: premetamorphic taste buds (TBs) in larval forms and taste disks (TDs) in postmetamorphic animals. The TBs have been found in the epithelium of the whole oropharyngeal cavity of larval forms, while in adults TDs appear only at the end of metamorphosis. The TDs can be papillary (or fungiform) on the soft (secondary) tongue and non-papillary outside the tongue. Two main cyto-morphological criteria distinguishing TDs from TBs have been established: (1) high differentiation of "nonsensory" components of a taste organ into several kinds of cells (often named "associate cells")--at least mucous cells and, separating them, wing cells; (2) a considerably larger area of the sensory epithelium than that in TBs, as the consequence of the large size of the mucous cells. In contrast to TDs each TB consists of longitudinally elongated supporting cells and taste cells, as well as of horizontally oriented basal cells, adjacent to the basement membrane. The sensory area in TBs measures 10-12 microm in diameter, while that in TDs has diameter of 45-90 microm. The anlage of the secondary tongue appears as a small folding of the floor epithelium just in front to the tip of the primary tongue in larvae 3 cm long, and is definitely formed in an animal with body length of about 6 cm.     

肺癌图像数据库及可视化工具的建立

肺癌是目前最常见的恶性肿瘤,也是已知的确诊后存活率最低的癌症之一。建立大规模的肺癌图像数据库是进行肺癌计算机辅助诊断(CAD)研究,开展肺癌诊断教育和训练以减轻医生负担,以及提高医疗诊断效率的基础。本文针对当前的肺癌图像数据库联盟(LIDC)在使用中存在的数据存取困难、缺乏对数据可视化和数据检索的支持等问题,提出了一个集数据模型、可视化和数据检索工具为一体的肺癌数据库平台。本文从分析LIDC的数据格式入手,引入数据库技术设计完成了肺癌数据库,以对获取的大量的肺癌图像数据进行管理和使用;针对数据可视化和检索的需要,设计了用于图像及其标注可视化的浏览器和数据查询器。研究结果表明该平台能很好地完成肺癌数据的存储、整合、可视化和检索,促进了肺癌诊断的研究。     

单肺移植手术前后的供体肺保护

目的 探讨肺移植手术前后供体肺保护的处理经验.方法 回顾性分析了2003年1月至2006年8月本院施行的同种异体单肺移植手术9例,其中左侧3例,右侧6例.冷低钾肺保护液灌注移植肺,术后三联免疫抑制剂抗排斥,并分析术后的胸片评分、氧合指数及肺动脉压变化情况.结果 供体肺缺血时间平均为(308.6±50.8)min.8例患者均成功脱离呼吸机并存活过围手术期(＞30 d),术后拔除气管插管时间平均(4.8±3.4)d,1例未能脱机并在术后22 d死亡.结论 肺保护需要在多个环节中加以控制,不同时期的保护侧重点不同.     

Development of the adult endocrine pancreas during metamorphosis in the sea lamprey,Petromyzon marinus L. II. Electron microscopy and immunocytochemistry

The development of the adult endocrine pancreas was followed throughout metamorphosis in the sea lamprey using electron microscopy and immunocytochemistry. It was discovered that the caudal pancreas develops from the larval extrahepatic common bile duct through the process of transdifferentiation (dedifferentiation/redifferentiation). Early in metamorphosis the bile duct epithelial cells possess large vacuoles, resembling autophagic vacuoles, containing recognizable cell material. There is a loss of the large bundles of intermediate filaments characteristic of the larval bile duct epithelium. These same cells are then seen to contain granules immunoreactive for insulin. Pancreatic islets develop within the base of the bile duct epithelium from these transdifferentiated cells and migrate into the surrounding connective tissue to form the caudal pancreas. The cranial pancreas was found to develop from the epithelia lining the developing adult diverticulum and anterior intestine in a similar fashion as those in the larva. The second cell type to appear in either portion of the developing pancreas is similar to the third cell type of the adult: cells immunoreactive for somatostatin do not appear until late in metamorphosis in either region. © 1993 Wiley-Liss Inc.     

单肺移植手术前后的供体肺保护

目的探讨肺移植手术前后供体肺保护的处理经验。方法回顾性分析了2003年1月至2006年8月本院施行的同种异体单肺移植手术9例,其中左侧3例,右侧6例。冷低钾肺保护液灌注移植肺,术后三联免疫抑制剂抗排斥,并分析术后的胸片评分、氧合指数及肺动脉压变化情况。结果供体肺缺血时间平均为(308.6±50.8)min。8例患者均成功脱离呼吸机并存活过围手术期(>30d),术后拔除气管插管时间平均(4.8±3.4)d,1例未能脱机并在术后22d死亡。结论肺保护需要在多个环节中加以控制,不同时期的保护侧重点不同。     

Expression and localization of FGFR1, FGFR2 and CTGF during normal human lung development

Aim of our study was to provide insight into the temporal and spatial expression of FGFR1, FGFR2 and CTGF during normal human lung development which may have an important impact on understanding occurrence of developmental lung anomalies. Morphological parameters were analysed using double immunofluorescence on human embryonal (6th and 7th developmental week-dw) and foetal (8th, 9th and 16th developmental week) human lung samples.FGFR1 and FGFR2 was positive during all the dw in both the epithelium and mesenchyme. The highest number of FGFR1 positive cells was observed during the 6th dw (112/mm²) and 9th dw (87/mm²) in the epithelium compared to the 7th, 8th and 16th dw (Kruskal-Wallis test, p < 0.001, p < 0.0001). The highest number of FGFR1 positive cells in the mesenchyme was observed during the 8th dw (19/mm²) and 16th dw (13/mm²) compared to the 6th, 7th, and 9th dw (Kruskal-Wallis test, p < 0.001, p < 0.0001). The number of FGFR1 positive cells in the epithelium was higher for FGFR2 compared to number of positive cells (Mann-Whitney test, p < 0.0001). FGFR2 showed the highest number in the epithelium during the 7th dw (111/mm²) and 9th dw (87/mm²) compared to 6th, 8th and 16th dw (Kruskal-Wallis test, p < 0.001, p < 0.0001, p < 0.01 respectively). The highest number of FGFR2 positive cells in the mesenchyme was observed during the 9th dw (26/mm²), compared to the 6th, 7th,8th and 16th dw (Kruskal-Wallis test, p < 0.0001), while the number of FGFR2 positive cells in the epithelium was significantly higher than in the mesenchyme (Mann-Whitney test, p < 0.0001). CTGF was negative in both epithelium and mesenchyme during all except the 16th dw in the mesenchyme where it co-localized with FGFR2.FGFR1 and FGFR2 might be essential for epithelial-mesenchymal interactions that determine epithelial branching and mesenchymal growth during early lung development. Sudden increase in FGF1 in the epithelium and FGF2 in the mesenchyme in the foetus at 9th dw could be associated with the onset of foetal breathing movements. CTGF first appear during the foetal lung development.     

Synthesis and expression of laminin during human foetal lung development

Backgrounds: The lung develops by epithelial tubes budding and branching into a flexible mesenchyme. This growth is associated with the remodelling of the epithelial basement membrane, of which laminin is a major component. Methods: Both the synthesis and expression of laminin were studied in the human lung between 10 and 31 weeks of gestation, using in sity hybridization and immunohistochemistry. Results: The synthesis of the β chain was active in the epithelial and surrounding mesenchymal cells. The mRNAs coding for the γ chain were less abundant and mainly found in the epithelium. The synthesis of these two chains continued throughout gestation, and no significant difference in the density of hybridization grains could be detected between the tips of the expanding buds and the proximal portions. Immunohistochemical localization of laminin showed important modifications of the basement membrane during gestation. In the first part of the pseudoglandular stage the epithelial basement membrane stained continuously for laminin. Later, the basement membrane was labelled in a graded fashion: at the apex of the growing buds the staining became weak with focal disruptions. Both epithelial and mesenchymal synthesis of laminin remained active, while the polypeptide was undetectable using immunohistochemistry. Conclusions: These findings suggest that the remodelling of the basement membrane during human lung morphogenesis is probably not related to a decreasing synthesis of laminin, but to either a proteolytic degradation or the assembly of an inadequate complex undetectable with the polyclonal antibody antilaminin. © 1995 Wiley-Liss, Inc.     

内毒素肺损伤肺淋巴变化的实验研究

本实验应用清醒绵羊内毒素肺损伤模型对内毒素致伤后肺淋巴液的变化作了研究。内毒素致伤后,肺动脉压(Ppa)、肺微血管压(PMV)、肺淋巴流量(QL),淋巴白蛋白/血浆白蛋白比值(LA/PA)、淋巴胶体渗透压(π_(i))和肺微血管滤过系数(Kf)均明显增加。压力和通透性变化对QL的影响之比,在Ⅰ期(0～2h)和Ⅱ期(2～6h)分别为1∶0.53和1∶2.31。提示了PMV增高为Ⅰ期肺水肿形成的主要因素,通透性增加为Ⅱ期的主要因素。