Sectorial angioarchitecture of the human tibia.

The blood supply of the periosteum of the human tibia was investigated by anatomical dissection of 12 lower extremities which were filled with injection mass. By division of the tibia into 4 segments (proximal and distal fifths; proximal and distal diaphysis) a general supplying system of the periosteum was found. The proximal fifth of the tibial periosteum is nourished by branches of the arteriae recurrentes tibiales anterior et posterior and the aa. inferiores medialis et lateralis genus. At the proximal diaphysis (next three tenths of the tibia) periosteal branches arise from the aa. tibialis anterior and posterior, whereas the distal diaphysis is nourished exclusively by semicircular vessels of the a. tibialis anterior which twine around the bone and merge with each other at the facies medialis. Concerning the periosteal blood supply of the distal fifth of the tibia, two different types were found. In two thirds of the cases the lateral side was nourished by branches of the a. tibialis anterior, which are supported by vessels from the a. fibularis. In one third the latter branch was absent so that the rami periostales arising from the a. tibialis anterior nourished the lateral aspect of the distal tibia alone. The dorsal region was supplied in all cases by rami of the a. fibularis and a. tibialis posterior. On the medial side the periosteal nourishment is ensured only by anastomosis. Branches of the a. tibialis anterior supply the facies lateralis and facies posterior where it is supported by vessels of the a. tibialis posterior and in a minor region of rami of the a. fibularis (distal) and a. poplitea (proximal).(ABSTRACT TRUNCATED AT 250 WORDS)     

The angioarchitecture of estrous, pseudopregnant and pregnant rabbit ovary as seen by scanning electron microscopy of vascular corrosion casts

Ovarian angioarchitecture was studied by scanning electron microscopy of vascular corrosion casts in estrous, pseudopregnant (stimulated with human chorionic gonadotropin) and pregnant rabbits. In all samples, the proper ovarian branch of the ovarian artery (ramus ovaricus) entered the ovarian hilus near the caudal pole of the organ and ran parallel to the major axis of the hilus. The extraovarian venous drainage was formed by several vessels emptying into a distal large vein. The ramus ovaricus exhibited various degrees of coiling and branched in the medulla. The coiling of the ramus ovaricus and its ramifications were maintained in all samples. A venous meshwork and/or flat vein branches closely enveloped the arterial coils found in the hilus and outer medulla. At this level numerous arteriovenous contacts were demonstrated in all samples. The coiled arteries, prior to entering the ovarian cortex, supplied several small peripheral follicles which were drained by the hilar veins. In the cortex the coiled arteries branched in numerous thin, straight or slightly undulated arterioles which supplied developing estrous follicles and pseudopregnant corpora lutea. The arterioles supplying the pregnant corpora lutea were long, large and tightly spiraled. The venous drainage followed the modifications of the arterial supply. These data demonstrate that ovarian cycle and pregnancy induced significant changes in the cortical vessels, which adapted their structure to the temporary functional needs of the recruited follicles or corpora lutea. Hilar and medullary vessels have permanent structures that may represent morphological devices for (a) a continuous control of the blood flow (spiral arteries) and (b) a local recirculation of endocrine products (arteriovenous contacts) comparable to the ”countercurrent mechanism” previously shown to operate in ovaries of other species, but not yet found in rabbits. Received: 19 June 1996 / Accepted: 7 October 1996     

Light microscopic study of the hypophyseal angioarchitecture in the rabbit

This study describes the hypophyseal angioarchitecture found in 79 adult New Zealand white rabbits. The pituitary glands and attached hypothalami were removed and carefully processed following routine histological methods, and the vascular organization was studied by light microscopy. Whole mounts of the pituitary median eminence complex were prepared and studied with a binocular dissecting microscope employing transmitted and epi-illumination. Arterial blood was found to be directed primarily to the neurohypophysis by the superior hypophyseal artery (SHA) and the inferior hypophyseal artery (IHA). A direct arterial blood supply was found to the adenohypophysis, but was limited solely to the pars intermedia by branches of the anterior hypophyseal artery (AHA) and the IHA. Capillaries of the pars intermedia were subdivided into an intermediate and a superficial plexus. The superficial plexus was situated between the intermediate plexus and the capillaries of the infundibular process. Capillaries of the superficial plexus did not form anastomoses between themselves, but ramified into the intermediate plexus to form a dense network of anastomosing capillaries that were continuous with capillaries of the pars distalis. A direct arterial blood supply was found only to the superficial plexus.     

An injection-corrosion study on the angioarchitecture of rat skin]

The angioarchitecture of the skin in the SD strain rat was investigated by scanning electron microscopy using resin cast. The neck part of rat skin was composed of 3 layers of vascular networks: the first layer (superficial layer), the second layer (middle layer), and the third layer (deep layer). Two types of capillary architectures were present around the hair follicle: small architectures composed of random network and large architectures composed of 3 parts distinguished by the construction of network. The large architecture, the capillary of hair papilla and the capillary network of sebaceous gland was thought to compose one circulation unit. The afferent vessels into such units branched from Kandelaberarterie-Petersen occurring from the 3rd layer, ascended to the 2nd layer, then descended to the bottom of the network and composed the capillary architecture. There were 2 types of efferent vessels from such circulation unit. They occurred from superficial and deep part, respectively, of the vascular architecture around the hair follicle and descended straight to the 3rd layer. The presence of straight vessels between the 2 nd and 3 rd layer, and the simple arrangement of vascular layers were thought to be characteristic of the angioarchitecture of the rat skin.     

Histochemical observations on mucin secretion by subsurface epithelial structures in the canine ovary

Histochemical methods for mucins were applied to the ovaries of 23 dogs. Solid and hollow groups and cords of epithelial cells (subsurface epithelial structures, SES) in the outer part of the cortex regularly showed evidence of mucin secretion. Intracytoplasmic, sialic acid-containing, acid mucin secretion droplets were seen in solid and hollow SES, and secretion was present in both closed lumina and those opening onto the surface. Intracytoplasmic droplets in the cells of SES were distinctive, and similar droplets were not found in the cells of any other ovarian epithelial component. The secretion of SES was not shown to possess distinctive histochemical features. Mucin production was also observed in follicles, corpora lutea and rete tubules. The significance of ingrowth from the ovarian surface epithelium in adult life, and of secretory activity by the cells of SES, are discussed.     

cDNA-derived primary structure of the glycoprotein component of canine microsomal signal peptidase complex

Canine microsomal signal peptidase activity has been shown previously to co-migrate as an apparent complex of six polypeptides with molecular masses of 25, 23, 22, 21, 18, and 12 kDa. The 22- and 23-kDa species are differentially glycosylated forms of the same protein, designated SPC 22/23. The amino acid sequence of SPC 22/23 was deduced from cDNA clones. The protein is synthesized without a cleavable amino-terminal signal sequence and contains a single site for N-linked glycosylation. SPC 22/23 appears to be anchored to the rough endoplasmic reticulum membrane by a single hydrophobic segment near its amino terminus, with the remainder of the protein positioned on the lumenal side of the membrane. The amino acid sequence of SPC 22/23 shares homology with tryptic peptides derived from the hen oviduct signal peptidase glycoprotein, one of two possible proteins required for signal peptide processing in the avian system (Baker, R.K., and Lively, M.O. (1987) Biochemistry 26, 8561-8567). Therefore, the complete amino acid sequence of SPC 22/23 presented in this report corresponds to one of two possible proteins required for signal peptide processing in higher eukaryotic cells.     

Distribution of a matrix component of the midbody during the cell cycle in Chinese hamster ovary cells

Monoclonal antibodies were raised against isolated spindles of CHO (Chinese hamster ovary) cells to probe for molecular components specific to the mitotic apparatus. One of the antibodies, CHO1, recognized an antigen localized to the midbody during mitosis. Immunofluorescence staining of metaphase cells showed that although the total spindle area was labeled faintly, the antigen corresponding to CHO1 was preferentially localized in the equatorial region of the spindle. With the progression of mitosis, the antigen was further organized into discrete short lines along the spindle axis, and eventually condensed into a bright fluorescent dot at the midzone of the intercellular bridge between two daughter cells. Parallel immunostaining of tubulin showed that the CHO1-stained area corresponded to the dark region where microtubules are entrapped by the amorphous dense matrix components and possibly blocked from binding to tubulin antibody. Immunoblot analysis indicated that CHO1 recognized two polypeptides of mol wt 95,000 and 105,000. The immunoreaction was always stronger in preparations of isolated midbodies than in mitotic spindle fractions. The protein doublet was retained in the particulate matrix fraction after Sarkosyl extraction (Mullins, J. M., and J. R. McIntosh. 1982. J. Cell Biol. 94:654-661), suggesting that CHO1 antigen is indeed a component of the dense matrix. In addition to the equatorial region of spindles and midbodies, CHO1 also stained interphase centrosomes, and nuclei in a speckled pattern that was cell cycle-dependent. Thus, the midbody appears to share either common molecular component(s) or a similar epitope with interphase centrosomes and nuclei.     

A stereological study of the angioarchitecture of the cerebral cortex in rabbits]

An attempt is made to describe the vascular architecture of the cortex employing a stereological method. Brains perfused with india ink were sectioned in frontal, sagittal and tangential levels. The course of the vessels was described as a spatial vector from the center to the penetration point of the globe or radius 1. In order to present a two-dimensional image, we projected the penetration point together with the longitudinal and horizontal meridians of the globe in an orthograde fashion into the level of the image. The frontal and sagittal sections were projected in an equatorial image, the tangential level was projected to an axis. Direct observations and stereological imaging demonstrated that, in lamina 4, there is a relatively constant hexagonal vascular net with branching angles of 60 degrees at an edge length of 50--60 microns.     

Mesenchymal‐like stem cells in canine ovary show high differentiation potential

Objectives

Recent studies have reported the existence of stem cells in ovarian tissue that show enhanced proliferative and differentiation potential compared to other adult tissues. Based on this evidence, we hypothesized that ovarian tissue contained mesenchymal‐like stem cells (MSC) that could be isolated using a novel rapid plastic adhesion technique.

Materials and methods

We established MSC lines derived from ovarian and adipose tissue based on their ability to rapidly adhere to plastic culture dishes in the first 3 hours after plating and studied their potentiality in terms of molecular markers and differentiation capacity.

Results

Morphological and kinetic properties of in vitro cultured ovarian MSC were similar to adipose‐derived MSC, and both reached senescence after similar passage numbers. Ovarian‐derived MSC expressed mesenchymal (CD90 and CD44) but not haematopoietic markers (CD34 and CD45), indicating similarity to adipose‐derived MSC. Moreover, ovarian‐derived MSC expressed NANOG, TERT, SOX2, OCT4 and showed extensive capacity to differentiate not only into adipogenic, osteogenic and chondrogenic tissue but also towards neurogenic and endodermal lineages and even precursors of primordial germ cells.

Conclusion

These results show for the first time the derivation of ovarian cells with the molecular properties of MSC as well as wide differentiation potential. Canine ovarian tissue is accessible, expandable, multipotent and has high plasticity, holding promise for applications in regenerative medicine.

     

Isolation of phospholamban and a second proteolipid component from canine cardiac sarcoplasmic reticulum

We have isolated two proteolipid fractions from canine cardiac sarcoplasmic reticulum by chromatography on columns of Sepharose CL-6B, and Sephadex LH-60. One, “fraction B”, is phosphorylated by cyclic AMP-dependent protein kinase and was identified as phospholamban, the activator of cardiac sarcoplasmic reticulum. The other, “fraction A”, is not phosphorylated and has an amino acid composition very similar to those of proteolipids we previously isolated from (Na,K)-ATPase.     

Drug-resistant mutants of chinese hamster ovary cells possess an altered cell surface carbohydrate component

Surface label experiments using the galactose oxidase-[³ H] -borohydride technique reveal that cells from drug-resistant Chinese hamster ovary clones possess a surface carbohydrate component of apparent molecular weight 165,000 which is absent from wild-type cells. The component may also be demonstrated by [¹⁴C] glucosamine incorporation but not by [³ H] leucine incorporation or by the lactoperoxidase surface labeling reaction.     

The exocyst component Sec5 is required for membrane traffic and polarity in the Drosophila ovary

The directed traffic of membrane proteins to the cell surface is crucial for many developmental events. We describe the role of Sec5, a member of the exocyst complex, in directed membrane traffic in the Drosophila oocyte. During oogenesis, we find that Sec5 localization undergoes dynamic changes, correlating with the sites at which it is required for the traffic of membrane proteins. Germline clones of sec5 possess defects in membrane addition and the posterior positioning of the oocyte. Additionally, the impaired membrane trafficking of Gurken, the secreted ligand for the EGF receptor, and Yolkless, the vitellogenin receptor, results in defects in dorsal patterning and egg size. However, we find the cytoskeleton to be correctly oriented. We conclude that Sec5 is required for directed membrane traffic, and consequently for the establishment of polarity within the developing oocyte.