The clinical significance of candidal casts

Examination of the urinary sediment for fungal casts is a new and simple approach for assessing renal involvement in fungal infections. Identification of candidal casts was used to diagnose renal fungal involvement in five immunocompromised patients. In three cases, the examination of the urinary sediment permitted the diagnosis of early and presumably noninvasive renal candidal infections that cleared easily with relatively low doses of antifungal therapy. In two other cases, the recognition of candidal casts confirmed renal involvement in patients with disseminated disease.     

家兔回肠淋巴管铸型的扫描电镜研究

目的：观察家兔回肠淋巴管的三维结构和微细分布。方法：淋巴管铸型样品，通过扫描电子显微镜进行观察；半薄切片样品，用光镜进行观察。淋巴管铸型剂是Mercox，采用回肠壁间接注射法，将注入铸型剂的回肠壁切下，置入NaOH水溶液中腐蚀，直到肠壁组织完全脱离为止，然后将淋巴管铸型样品置于扫描电镜下观察。结果：在小肠绒毛内清晰地显示出中央乳糜管，每个绒毛中有2～3个中央乳糜管，中央乳糜管与粘膜层毛细淋巴管丛相连通，粘膜层毛细淋巴管注入粘膜下层淋巴管，后与肌层淋巴管相吻合，肌层淋巴管连接浆膜层淋巴管，然后汇入小肠系膜淋巴管。淋巴管呈串珠样外观，其表面存在双凹切迹，该处相当于淋巴瓣的部位。铸型表面还可以见到淋巴管内皮细胞核的压迹。结论：淋巴管铸型清晰地显示家兔回肠壁粘膜层丰富的中央乳糜管和毛细淋巴管丛以及粘膜下层、肌层毛细淋巴管和大量的淋巴管的三维结构。     

The Microvascular Anatomy of the Trachea in Adult Xenopus laevis Daudin (Lissamphibia; Anura): Scanning Electron Microscopy of Vascular Corrosion Casts and Correlative Light Microscopy

Studies on the amphibian respiratory tract microvascular anatomy are few and contradictory. Using scanning electron microscopy of vascular corrosion casts, correlative light microscopy of paraplast‐embedded Goldner‐stained serial tissue sections, and three‐dimensional morphometry, we studied the topographic microvascular anatomy in the trachea of the adult South African Clawed Toad, Xenopus laevis Daudin. Histomorphology showed that the cartilaginous portion of the trachea contained irregularly shaped hyaline cartilage plates in its cranial and caudal portions and C‐shaped hyaline cartilage rings in the middle portion. Tracheal cartilages formed large continuous plates on the ventral circumference, numerous small discontinuous plates on the dorsal circumference, and large vertical plates on the caudolateral circumference. The muscular portion of the trachea consisted of bands of smooth muscle that joined the free ends of cartilage plates. The supply of the trachea was via pulmonal artery—tracheobronchial trunk artery—tracheobronchial artery—tracheal artery. The subepithelial capillary network consisted of rectangular meshes which are in the area of the tracheal cartilages located between the cartilages and the respiratory epithelium. Small tracheal veins merged into a single tracheal vein that emptied into the pulmonary vein. Because of its dense subepithelial capillary network and its drainage into the pulmonal vein, the trachea could actively take part in respiration. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.     

Venous drainage of the dorsal sector of the liver: differences between segments I and IX A study on corrrosion casts of the human liver

Summary The aim of this study was to determine the venous drainage of the dorsal sector of the liver in order to define the differences between segments I and IX and thier implications for sectorially and segmentally oriented hepatic surgery. The study was based on corrosion casts of 61 macroscopically healthy livers. The drainage pathways of veins at least 10 mm long and 1 mm wide were evaluated and statistically analysed. On average, 9 veins drained the two segments and three veins from both segments entered the inferior vena cava. In 95% of cases the veins from segment I drained predominantly into the inferior vena cava, whereas in segment IX this pathway was dominant in only 30% of cases. In 64% of cases a vein originating in segment IX entered the right hepatic v. The difference in the venous drainage of the two segments suggests that segment IX partly belongs to the neighbouring segments and may thus be only a paracaval region of the right liver.

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Drainage veineux du secteur dorsal du foie. Étude comparative des deux segments I et IX sur des foies humains injectés et corrodés

Résumé L'objet de cette étude concerne le drainage veineux du secteur dorsal du foie et plus précisément les segments I et IX avec des implications sur la chirurgie hépatique sectorielle et segmentaire. L'étude repose sur 61 injections — corrosions de foies non pathologiques prélevés selon les règles éthiques et légales. Les voies de drainage veineux d'un calibre d'1 mm et de 10 mm de longueur sont étudiées de façon statistique. Les deux segments sont drainés par 9 veines en moyenne, dont 3 gagnent directement la veine cave inférieure. Dans 95% des cas, les veines des segments I se drainent préférentiellement vers la veine cave inférieure, contre 30% pour les veines du segment IX. Dans 64% des cas, une veine du segment IX gagne la veine hépatique droite. Les différences de drainage entre les segments I et IX laissent entendre que le segment IX appartient au moins partiellement au segment voisin et de ce fait représente la partie latéro-cave du foie droit.

     

用注射复型SEM方法研究足月胎儿小肠粘膜的微循环

本文用注射甲基丙烯酸甲酯复型扫描电镜方法,研究了足月胎儿小肠粘膜血管的立体构筑形象。绒毛毛细血管网的特征为管腔大部分呈窦状,其间夹杂有直形毛细血管;在十二指肠乳头处,胆总管壶腹口周围及壶腹粘膜的毛细血管多呈丛状,未见窦状毛细血管。绒毛的毛细血管网接受来自三方面的动脉血,即通过来自粘膜下动脉的微动脉,从绒毛顶部、基底部和腺丛的交通支,向绒毛毛细血管网供血。后者构成小肠绒毛的“门脉系统”。微动脉在绒毛顶部与微静脉有交通支,构成动静脉吻合。微静脉从顶部到基底部贯穿整个绒毛,沿途自绒毛毛细血管网及腺丛接受属支,最终注入粘膜下静脉,与Mall的典型的“喷泉型”概念并不完全一致。     

The blood vessels of the cat girdle placenta. Observations on corosion casts, scanning electron microscopical and histological studies

Summary The fetal microvascular architecture of the feline near-term placenta was investigated using scanning electron micrographs of partially fractured corrosion casts from plastic-filled vessels. The findings were compared with those on corresponding semithin histological sections.The branches of both umbilical arteries and veins roughly follow a course parallel to the zonary girdle on the allantochorionic side of the feline placenta in an acute-angled pattern of ramifications. They join the double-layered capilary networks in the chorionic lamellae of the labyrinth, which generally exhibit a chorio-uterine orientation and are partially twirled. On the allantochorionic side of the labyrinth, these fetal capillary networks are suspended on the maternal stem-artery-system of the placenta; on the uterine side, they have peduncular or tuft-like endings of capillary loops and are flattened by the uterine septa, which at this level converge into the maternal veins. The chorionic capillary lamellae have a variable breadth and length and therefore need shorter or longer arterioles and venules from the allantochorionic side to become irrigated at any level of the labyrinth.As a result, the feline placenta is characterized by a generally one-way crosscurrent type of materno-fetal blood flow.Supported by the Stiftung zur Förderung der wissenschaftlichen Forschung an der Universität Bern     

Myocardial capillaries: Increase in number by splitting of existing vessels

Summary To study myocardial vascular development, stereological parameters were estimated in 24 Wistar rat hearts of six different age groups, from newborn to adult. The vascular surface density showed a sharp increase in the first 2 weeks, a peak around the age of 2 weeks, and then a steady decrease until it flattened in adulthood. In contrast, the vascular volume percentage, when plotted against age, decreased continuously with the greatest change in the first week, after which the curve flattened. These findings are compatible with an increase in the number of capillaries with a concomitant decrease of their diameters. Qualitative scrutiny of the histology did indeed support the idea that vessels become thinner. Reconstructions of the histological sections showed the same change three dimensionally. The reconstructions also demonstrated very small holes that seemed to go through the capillaries in the younger stages. Corrosion casts of the blood vessels were made using a casting resin. This was injected into the umbilical artery of rat embryos from 15 days gestation to birth. In postnatal rats of six age groups methacrylate was injected directly into the left ventricle. These casts supported the stereological data by showing an increase in number and decrease in diameter of capillaries, while during pre- and postnatal development, the intervascular spaces lengthened from small, irregular spaces to long, rectangular ones. Small holes, the probable precursors of such spaces, were clearly visible in the wider vessels of the youngest stages. All data point to an interesting mode of capillary growth, i.e. growth by division of existing vessels.     

The effect of commercially pure titanium and alternative dental alloys on the marginal fit of one-piece cast implant frameworks

OBJECTIVES: The purpose of this study was to measure and compare the passive fit and vertical fit of one-piece cast frameworks fabricated with three different materials: commercially pure titanium (CP Ti), cobalt-chromium alloy (Co-Cr) and nickel-chromium-titanium alloy (Ni-Cr-Ti). METHODS: Fifteen frameworks simulating bars for fixed prosthesis in a model with five implants were fabricated and arranged into three different groups according to the material used. The fit of the framework abutment interface was measured using an optical microscope, when only one screw was manually tightened at a terminal abutment (passive fit) or when all framework screws were tightened to 10 N cm torque (vertical fit). Data were statistically analyzed using Kruskal-Wallis and Mann-Whitney tests (alpha=0.05). RESULTS: Mean and standard deviation values of passive fit and vertical fit are presented, respectively: CP Ti [88 (74) microm and 22 (9) microm], Co-Cr [229 (184) microm and 66 (35) microm], Ni-Cr-Ti [200 (175) microm and 32 (24) microm]. There were no significant differences between passive fit of Co-Cr and Ni-Cr-Ti frameworks (p=0.313), but both alloys were statistically different from CP Ti (p<0.001 and 0.035, respectively), which showed the best results. As for vertical fit, CP Ti and Ni-Cr-Ti alloy were statistically similar (p=0.162) and they presented a better vertical fit than Co-Cr alloy (p<0.001). CONCLUSIONS: Within the limitations of this study, it was possible to conclude that one-piece cast frameworks resulted in unacceptable passive fit and vertical fit, no matter which material had been used to fabricate them. However, the best results were obtained using CP Ti followed by Ni-Cr-Ti and Co-Cr alloys, respectively.     

胎儿耳蜗微血管铸型的扫描电镜观察

目的 :观察胎儿耳蜗微血管构筑。方法 :应用微血管铸型技术结合扫描电镜观察 15例胎儿耳蜗血管。结果 :扫描电镜下 ,人类耳蜗血管的三维结构首次得以清晰显示。螺旋蜗轴动脉为供应耳蜗的主要动脉 ,进入蜗轴后反复发出外、中、内放射状动脉。微静脉主要位于鼓阶。结论 :2 8周龄以上胎儿耳蜗血管已发育完善 ,人类耳蜗血管分布呈现明显节段性和区域性。与其生理功能密切相关