bluuebunny/crossref_metadata_2025 huggingface dataset:
Autoradiographic and Liquid Scintillation Assessment of Beta- Amino-Propionitrile-Induced Inhibition of Collagen Maturation Using 3H-Proline and 3H-Lysine
Authors: Sandhu H.S. , Singh I.J. , Goren A.D.
Published: July 2008

BAPN (0.1 mg/day) was injected into chick embryos for 4 days starting on the 7th day of incubation. On the 11th day, the embryos were administered either 3H-proline or 3H-lysine. 36 h later, the incorporation of each isotope by the periosteal osteogenic cells as well as into bone matrix was investigated by autoradiography. The incorporation of the two isotopes into whole bones was assessed by liquid scintillation counting. 3H-proline incorporation into the cellular or matrical compartments was unaffected by treatment. As compared to the controls, 3H-lysine label in BAPN-treated embryonic bones was significantly higher in the cellular compartment but was reduced over the bone matrix. The data provide the first direct morphological evidence that BAPN probably induces certain changes in the maturation of collagen involving lysyl residues which result in an inhibition of cross-linkage formation in collagen.
Development of the Cardiac Blood Vessels in Staged Human Embryos
Authors: Hirakow Reiji
Published: July 2008

Serial paraffin sections (mostly stained with hematoxylin and eosin) of 52 human embryos at stages ranging from 13 to 20 (approximate ovulation age of 5–8 weeks) were examined. The first sign of definitive blood vessels was found to be localized in the apical incisure of the heart of an embryo at stage 14. Blood vessels of this kind closely resembled ‘blood islands’ in appearance, being composed of primitive erythroblasts surrounded by an outer layer of endothelium. At stage 16, a funnel-like invagination of the endothelium was recognized in the posterior wall of the sinus venosus. This structure was considered to represent one of the cardiac veins (probably the middle cardiac vein). A faint endothelial sprout of the left coronary artery was detected at stage 18, while the right one was observed later, at stage 19. Finally, at stage 20, both of the coronary arteries invariably existed with a covering of mesenchymal cells.
Effects of Post-Weaning Malnutrition on the Weight of the Head Components in Rats
Authors: Pucciarelli Héctor M. , Goya Rodolfo G.
Published: July 2008

Female Holtzman rats, weighing about 40 g, were given one of each of the following treatments: (a) 6% protein diet ad libitum throughout; (b) 6% protein diet for 2 weeks followed by 25 % protein diet ad libitum for 2 weeks; (c) 25 % protein diet fed in amounts isocaloric with treatment (a) and (d) 25% protein diet ad libitum throughout. These treatments were applied from weaning (21 days) to 49 days of age. Selected pairs of treatments were compared in order to elicit the influences of protein-calorie malnutrition, malnutrition recuperation, and protein deficit on both the absolute and relative weights of the following head components: skin (plus subcutaneous adipose tissue), muscular mass, eyeballs, skull, and encephalon. DNA and total protein concentrations in encephalon and muscle were also measured. The head components were classified into stables, for which growth decreased less than that of the head as a whole, and variables, for which growth decreased more than that of the head as a whole. The eyeballs, encephalon, and skull behaved as stable components, whereas the muscular mass and skin did so as variable components. The well-known modifications in the craniofacial growth pattern evoked by nutritional deficiencies were explained by the different reactions shown by the encephalon, functionally associated with the neurocranium, and the skeletal muscles, functionally associated with the masticatory apparatus. The changes observed in DNA concentration suggest that protein deficit delayed muscle growth through a decrease in cell size rather than a decrease in cell number in the muscular fibre.
Autoradiographic Localization of 3H-Dihydrotestosterone in the Reproductive Organs of Baboons
Authors: Weaker Frank J. , Sheridan Peter J.
Published: July 2008

The uptake and retention of radiolabelled dihydrotestosterone or one of its metabolites by both the male and female reproductive organs were examined in the baboon. 2 male and 2 female baboons were injected intravenously with 1 μg/kg body weight of 3H-dihydrotestosterone and 2 animals, 1 male and 1 female, were injected with both labelled and 100 μg/kg body weight of radio-inert dihydrotestosterone. 1.5 h after the injections, the animals were sacrificed and the uterus, cervix, vagina, uterine tube, labia minora, seminal vesicles, prostate, ductus deferens, and prepuce were removed and treated for autoradiography. The stratified squamous epithelia of the cervix, vagina, labia minora and prepuce demonstrated uptake of label in the germinative, but not in the superficial, cell layers. The columnar cells lining the uterine tube and cervical glands, but not the uterine glands, were labelled. In addition, the nuclei of the cells in the luminal epithelium of the prostate and seminal vesicles contained silver grains. The interstitial cells of the seminal vesicles, prostate and ductus deferens, and the smooth muscle of the prostate and ductus deferens, but not the seminal vesicles, demonstrated an uptake of radioactivity.
Bone Reactions to Tantalum Markers
Authors: Alberius Per
Published: July 2008

To elucidate intramembranous bone reactions to tantalum bone markers, 0.8-mm tantalum balls were implanted in the craniofacial region of 9 male New Zealand white rabbits. After 1, 2, 4 and 16 weeks the animals were sacrificed for SEM. Implant stability for these intervals was controlled by roentgen stereophotogrammetry. Fibrocytes and deposed fibers were seen to immediately adhere to the ball surface, getting retention in its porosities. A successively increasing bony support was observed to have intimate junctions without intervening fibers or soft tissues. No apparent differences in bone reactions were seen between the neurocranial and splanchnocranial bones. Osseointegration confirmed the inertness of tantalum to bone tissue and strongly confirms its suitability for implantation in bone.
Effects of Immobilization for 6 Weeks on Rabbit Knee Articular Surfaces as Assessed by the Semiquantitative Stereomicroscopic Method
Authors: Helminen H.J. , Jurvelin J. , Kuusela Tarja , Heikkilä Riitta , Kiviranta I. , Tammi M.
Published: July 2008

The effects of a 6-week immobilization period on rabbit knee articular cartilage surfaces were investigated by a new semiquantitative stereomicroscopic method following ink staining and processing for scanning electron microscopy. All surfaces of the immobilized knee joint were affected and displayed significant degenerative alterations. The knee joint contralateral to the immobilized one exhibited slight changes which could be interpreted as a sign of altered loading after immobilization. Articular surfaces of the patella and lateral condyle of the femur proved to be best suited for surface analysis on account of the small size, distinct borders and inherent evenness of the cartilage in non-treated animals.
The Microvasculature of Rat Salivary Glands
Authors: Ohtani Osamu , Ohtsuka Aiji , Lipsett Jill , Gannon Bren
Published: July 2008

The blood vessels together with the parenchymal components of rat salivary glands were studied by scanning electron microscopy (SEM) after removal of stromal connective tissue by acid hydrolysis plus enzymatic digestion. The three-dimensional vascular architecture was also studied by SEM of vascular corrosion cats. Each cluster of 4–5 polymorphous acini is connected with the convoluted duct via an intercalated duct. The convoluted duct usually has a sigmoid course and drains to the intralobular striated duct (about 20 µm in diameter); this has a rather straight course before connecting with the interlobular excretory duct. Myoepithelial cells with radiating processes were observed on the stromal surface of the secretory acini. Pericytes with longitudinal and circular processes were also observed surrounding the stromal surface of capillaries. The acini and convoluted ducts are surrounded by plexuses of capillaries derived from terminal arterioles which run along the intralobular duct system. The sinusoidal capillary plexus enveloping the striated duct receives blood from capillaries surrounding the acini and convoluted ducts through portal venules. The interlobular excretory ducts are richly supplied by a subepithelial network of capillaries which receive blood directly from the interlobular artery and drain into the interlobular vein. Thus, the excretory duct circulation is separated from the intralobular circulation. No arterio-venous anastomoses were observed in the gland. However, veno-venous and arterio-arterial anastomoses were often seen along the excretory duct; such anastomoses may participate in controlling the direction of blood flow through the vascular plexus around the excretory duct. The well-developed subepithelial plexus of capillaries observed around this duct is appropriate for its known absorptive/ secretory functions. The capillary network around the acini is densest in the parotid gland and sparsest in the sublingual gland. The subepithelial capillary network of the excretory ducts of the submaxillary gland is denser than those of the other two glands which had similar densities.
Annular Gap Junctions of the Equine Hoof Wall
Authors: Leach Doug , Oliphant Lynn
Published: July 2008

Incidental to studies of keratinization of the equine hoof wall, annular gap junctions were found in the stratum spinosum of the intertubular horn of the stratum medium. Adjacent cells of the stratum spinosum showed extensive gap junctions, and often local invaginations of one cell into another were bound by gap junctions. It is proposed that these invaginations become detached from the cell surface to form the annular gap junctions. Formation of annular gap junctions may be a means of disposing of plasma membrane in response to changes in cell volume or shape occurring in keratinization. Interiorization of gap junctions may also facilitate cell movement, and perhaps may act to reorganize desmosome-tonofibril arrangements by budding off appropriate interdesmosomal areas, thus drawing the desmosomes closer to one another.
Clearance of Materials from Breakdown of Uterine Collagen in Mice during Postpartum Involution
Authors: Shimizu Kiyoshi , Furuya Tetsuo , Takeo Yuji , Shirama Kazuhiko , Maekawa Kyutaro
Published: July 2008

The collagen content of the mouse uterus increases during pregnancy and rapidly decreases to the level of nulliparous mice within a few days post partum. Most of the hydroxyprohne in the uterine collagen had disappeared by day 3 post partum. During postpartum involution the hydroxyprohne concentration in both the serum and blood clot was not higher than in nulliparous mice. The total hydroxyprohne content in the liver, spleen and thymus was significantly increased during postpartum involution. These results indicate that materials derived from the breakdown of uterine collagen are rapidly removed from the blood stream by reticuloendothelial clearance.
Blood Vessels of the Bovine Chorioidea
Authors: Kohler Toni , Leiser Rudolf
Published: July 2008

On corrosion casts of the bovine choroidal vessels, the vascular architecture was investigated by means of scanning and corresponding transmission electron microscopy. Complete filling of the vessels produced close-fitting replicas. Thus, based on different luminal structure, the arteries and veins in the lamina vasculosa could be easily distinguished. The branches of these vessels were followed to the choriocapillaris. The complete pattern of afferent and efferent vessels provided the opportunity to establish a scheme of choroidal microcirculation. The choriocapillaris in the bovine as a freely communicating network is subdivided into star-shaped areas of roughly hexagonal form. On the boundaries of these areas the afferent vessels (arterioles) – arranged at regular distances – join the choriocapillaris, whereas drainage of the choriocapillaris is effected by a single efferent vessel (venule) in the center of each area.
Rasterelektronenmikroskopische Untersuchung des hyalinen Gelenkknorpels
Authors: Stofft Eckart , Graf Jürgen
Published: July 2008

Guinea pigs (pirbright white) were subjected to fixed mechanical stress in an endless-belt experiment. Shoulder, elbow, hip, and knee joints were taken and the articular cartilage was prepared for examination with the scanning electron microscope. Ultrastructural findings of cartilage surfaces were described, using different techniques for preparation and fixation. Mechanically stressed animals showed defects in their superficial ‘chondrosynovial membrane’ with visible fibre networks.
Immunocytochemical Demonstration of Two Vitamin D-Dependent Calcium-Binding Proteins in Mammalian Kidney
Authors: Schreiner D.S. , Jande S.S. , Parkes C.O. , Lawson D.E.M. , Thomasset M.
Published: July 2008

Distribution of vitamin D-dependent calcium-binding proteins (CaBPs) were studied in four mammalian species using monospecific antibodies raised against chick duodenal CaBP (D-CaBP), human cerebellar CaBP (L-CaBP), and rat duodenal CaBP (S-CaBP). The immunoperoxidase technique of unlabelled antibodies was employed. The distribution of D-CaBP/L-CaBP was identical in all the species studied except for the monkey, in the rat, pig, and human nephrons, D-CaBP/L-CaBP was seen in the cytoplasm of the cells of the distal convoluted tubules, initial segments of the collecting ducts and interspersed cells of the collecting ducts. Proximal convoluted tubules, glomeruli and maculae densae were negative. In the monkey, in addition to the cells of the distal convoluted tubules, the cells along the entire length of the collecting ducts were also strongly positive. S-CaBP was found to be species-specific, and hence positive results were obtained only in the rat nephron. The strongest positive reaction for S-CaBP was seen in the cells of the distal convoluted tubules. These same cells were also positive for D-CaBP/L-CaBP. S-CaBP was also detected in the cells of the thick ascending limb of the loop of Henle, along the entire length of the collecting ducts and in smaller amounts in cells of the macula densa. Intracellularly the S-CaBP was present only in the apical cytoplasm of positive cells. D-CaBP/L-CaBP stained the entire cytoplasm but the staining in the apical cytoplasm was denser.
Correlated TEM, SEM, and Histological Observations of Filiform Papillae of the Cow Tongue
Authors: Steflik David E. , Singh Baldev B. , Mckinney, Jr. Ralph V. , Boshell Jerry L.
Published: July 2008

The ultrastructural and histological characteristics of the filiform papillae of the cow tongue are described. These large, conical papillae display a fully keratinized external projection, which demonstrates a dominant hard keratin core partially ensheathed by soft keratin. This biostructure differentiates from a dominant posterior cell line, leading to the hard keratin core, and a thinner anterior cell line which, with contributions from an inter-papillary cell line, appears responsible for an attenuating sheath of soft keratin around the hard keratin core. The hard keratin cell line differentiates from cells devoid of keratohyalin granules (KHG), which are rich in thick bundles of tonofilaments. The soft keratin cell line differentiates from cells containing both eosinophil and basophil KHG and dispersed tonofilaments. The bovine filiform papilla also appears similiar in biostructure to the mammalian hair shaft and the ‘filiform hairs’ of the rat penis.
Cell Types of the Pars distalis of the Hedgehog (Erinaceus europaeus L.) Adenohypophysis: Cytological, Immunocytochemical and Ultrastructural Studies. II.
Authors: Girod C. , Lhéritier M. , Trouillas J. , Dubois M.P.
Published: July 2008

Staining and histochemical methods, immunofluorescence, and electron microscopy were used to individualize the prolactin cells in the adenohypophyseal pars distalis of the nonhibernating hedgehog. One cell type was differentiated; their characteristics at the light and electron microscopic levels were presented. Immunofluorescence has confirmed the functional significance of this cell type and the validity of the denomination ‘prolactin cells’.
Projections of the Caudate Nucleus in Cats and Kittens
Authors: Nieto Adela , Torrero Carmen , Salas Manuel
Published: July 2008

Small electrolytic lesions were placed on the head of the caudate nucleus of kittens between 8 and 21 days postnatally and in adult cats. Coronal sections of the whole brain were studied under the light microscope with the Fink and Heimer staining method. Degenerating axon terminals could be recognized after a survival period of 30 h for kittens and 8 days for adults, as dark spots and broken fibers. The results indicate extensive degenerative lesions at both diencephalic and brain stem levels. In general the degenerative lesions were denser in kittens when compared with adult animals. The results of this study suggest that the caudate nucleus of immature animals could be more sensitive to the lesions occurring during the time of early synaptogenesis. Moreover, the caudate nucleus could be an important point of convergence of descending pathways exerting a diffuse modulatory action upon several brain structures related to movement.
A Combined Histochemical-Neurophysiological Technique for Investigating the Extent of Diffusion of Intracerebrally Injected Drugs
Authors: Girgis Makram
Published: July 2008

In order to ‘dissect out’ the function of a given region of the brain, the local application of a chemical transmitter probably parallels closely what is actually occurring biologically at the local site. This paper addresses itself to the problem of diffusion of drugs and describes the application of a modern device (the osmotic minipump) which produces a constant flow of minute quantities of the agent into the brain structure. Neurophysiological, behavioural, and histochemical investigations have been carried out in different species. Although the histochemical results of the minipump experiments indicate some spread, yet this seems to be at a concentration which would have no apparent pharmacological action. This was confirmed by our neurophysiological and behavioural studies and also by some recent reports in the literature.
Collagen Degradation in the Mouse Uterus during Postpartum Involution: Extracellular Pathway
Authors: Shimizu Kiyoshi , Maekawa † Kyutaro
Published: July 2008

This study was undertaken to determine where most of the uterine collagen is degraded during the postpartum involution. The greater part of uterine collagen, which was estimated as hydroxyproline, had disappeared by day 2 post partum. Colchicine, which decreases phagocytic activity, did not affect the uterine collagen degradation. Phagocytic activity in the post partum uterus did not appear until day 3 post partum. These results suggest that most of the uterine collagen is degraded by the extracellular but not by the intracellular pathway.
Thin-Section, Tracer, and Freeze-Fracture Study of the Smooth-Ended Maturation Ameloblasts in Rat Incisors
Authors: Sasaki T. , Higashi S. , Tachikawa T. , Yoshiki S.
Published: July 2008

The morphology and functional roles of the smooth-ended maturation ameloblasts (SAs) of rat incisors were examined by means of routine thin sections, tracer experiments, and freeze-fracture replication. SAs possessed two sets of junctional complexes consisting of tight junctions (fasiae occludentes) and gap junctions at the proximal and distal ends. Neither the proximal nor the distal junctional complex formed a complete barrier around the cell; intravenously injected horseradish peroxidase (HRP) reached the developing enamel surface through SAs extracellular spaces. SA supranuclear cytoplasm included such various cytoplasmic vesicles as the multivesicular body (MVB), large and small vacuoles, dense body, and coated vesicles. The HRP that reached the enamel surface was incorporated into some coated vesicles and small vacuoles via coated pits and membrane invaginations of the distal cell surface of SA. Then, in the process of time, it migrated into the MVB and large endocytic vacuoles. These results indicate that the SA layer forms an extracellular transfer route for metabolites between papillary layer and the enamel surface and that SAs absorb exogenous protein.
Ultrastructural Basis of the Coordination of Ciliary Movement
Authors: González Santander R. , Martínez Cuadrado G. , Rubio Sáez M. , Bujan Varela J. , Laraña Solé A.
Published: July 2008

A hypothesis for contraction was suggested (molecular basis of the transmission of ciliary coordination) by means of the slipping and interdigitation of the microfilaments of one period with those of the adjacent periods, occurring at the level of the periodic band. The amplitude of the period is greater in the relaxed than in the contracted state, while the reverse is true with the periodic band amplitude. The microfilament length is constant, probably varying with the species. This hypothesis of the slipping and interdigitation of the microfilaments would be the basis of the ciliary coordination from cilium to cilium and from cell to cell, because of the anchoring of the bunches in the peribasal complexes and in the adherent connection complexes, respectively.
Histochemistry of Connective Tissue Cells in Subcutaneous Adipose Tissue of Normal and Decapitated Pig Fetuses
Authors: Hausman G.J.
Published: July 2008

Connective tissue cells that are histochemically and morphologically distinct from ‘fibroblasts’ are localized around developing hair follicles in the pig and rat. Immature adipose tissue is limited to small areas immediately around fully descended hair follicles in the rat hypodermis. In the present study, connective tissue around large nerves and blood vessels in fetal pig subcutaneous tissue was examined for the presence of enzymes typical of adipocytes. Samples from decapitated pig fetuses were studied so that the effects of an altered hormonal profile could be examined. Samples of dorsal subcutaneous adipose tissue were obtained from fetuses at 65, 70, 85, 90, 110, and 112 days of gestation. Fetuses were decapitated in utero at 45 days of gestation, and adipose tissue samples were obtained from these fetuses at 110 days of gestation. A close spatial relationship was observed between the growth of large blood vessels and nerves and fat cell cluster development in the older ( > 70 days) fetuses. Connective tissue cells that were contiguous with fat cell clusters were histochemically identical to adipocytes. The lipid histochemistry of the reactive connective tissue cells (histochemically identical to adipocyte) was variable in young fetuses. In all 110- and 112-day-old fetuses, the reactive cells contained lipid, whereas the reactive cells in decapitated fetuses were devoid of lipid. The reactive connective tissue cells were not associated with capillaries and did not contain basement membranes. The histochemistry of these cells suggests that they respond to a particular hormonal or metabolic profile as do adipocytes. Connective tissue cells contiguous with fat cell clusters may represent a distinct stage of adipocyte differentiation between the undifferentiated state and the mature adipocyte.
Postmortem Persistence of Acetylcholinesterase Activity in the Subfornical Organ of the Rat
Authors: Schneider Felipe Luis , Achaval Matilde , Rocha de Barros Viviane , Contu Paolo
Published: July 2008

Acetylcholinesterase (AChE) activity in the rat subfornical organ at 8, 12, 18, 24, 26, 28 and 30 h postmortem was evaluated by the Koelle and Friedenwald method. AChE activity was unchanged in animals 12 h postmortem. When the postmortem period was extended, enzymatic activity diminished, disappearing almost completely after 30 h.
A Quantitative Study of Microtubules in Motor and Sensory Axons
Authors: Pannese E. , Procacci P. , Ledda M. , Arcidiacono G. , Rigamonti L.
Published: July 2008

The number, density and distribution of microtubules were compared in the myelinated motor and sensory axons of the spinal roots of lizard (Lacerta muralis). In both motor and sensory axons the average number and density of microtubules were found to be related to the axonal size: the average number of microtubules rose, while the microtubular density decreased with an increase in the cross-sectional area of the axon. More precisely, a linear relationship was observed between the logarithm of the microtubular density and the cross-sectional area of the axon. No significant differences in the microtubular number and density were found between motor and sensory axons of corresponding size. Microtubules were unevenly distributed throughout the cross section of both motor and sensory axons. In particular, a nonaccidental association between microtubules and mitochondria was found in both axon types.
Embedding, Cutting and Grinding Methods to Produce Undecalcified Cortical Bone Sections Over the Whole Bone
Authors: Hutzschenreuter Paul , Brümmer Hans
Published: July 2008

Polyethylene bags as a container material are flexible and elastic enough to follow the shrinkage of monomers during the polymerization process, since the main cause of bubble building in the polymerization material is the shrinkage of the monomer methacrylic acid methylester. The polymerization time in polyethylene containers is shorter (3–5 days) than in glass containers (1–2 weeks). The length of the bone and the thickness of the cutting bone sections are the limiting factors for two different cutting and grinding procedures, which were described.
Microvascular Architecture of the Enamel Organ in the Rat-Incisor Maturation Zone. Scanning and Transmission Electron Microscopic Studies
Authors: Sasaki T. , Tominaga H. , Higashi S.
Published: July 2008

In order to clarify the microvascular architecture and ultrastructural features of the capillary vessels related to transendothelial transport of metabolites, scanning electron microscopy of tissues digested by HCl-collagenase and of vascular corrosion casts as well as thin-section, tracer, and freeze-fracture replications were employed to study the maturation zone of rat-incisor enamel organ. The enamel-organ maturation zone was shown to have a well-developed, dense capillary plexus. The capillary vessels were distributed along furrows formed by the enamel-organ papillary ridges. In central regions they formed a regular, blindlike network; in the peripheral regions, however, they formed an irregular, circular network. Everywhere except in the nuclear and perinuclear regions, the very thin capillary-vessel endothelial walls were pierced with numerous fenestrations. Such fenestrations were evident in endothelial walls facing the ameloblast-layer site. In tracer experiments, intravenously injected horseradish peroxidase passed through the fenestrations in the endothelial walls to diffuse throughout the enamel-organ extracellular spaces. It did not, however, pass through inercellular spaces or transendothelial channels. The dense, regular distribution of highly fenestrated capillaries in the enamel organ is thought to make possible the rapid transcapillary exchange of various metabolites between the vascular system and the ameloblast and papillary layers that is necessary for enamel maturation.
A Quantitative Electron Microscopic Analysis of the Membrana granulosa of Rat Preovulatory Follicles
Authors: Zoller Lawrence C.
Published: July 2008

The ultrastructure of the membrana granulosa (MG) of rat preovulatory follicles was examined using stereological techniques. Organelles studied were nuclei, mitochondria, lipid droplets (LD), lysosomes, and smooth and rough endoplasmic reticulum (SER, RER). The peripheral region of the MG contained the greatest volume of mitochondria, LD and SER, organelles associated with steroidogenesis. The volume of RER, an organelle associated with protein production, was greatest in the cumulus oophorus. These results corroborate previous analyses and demonstrate that the rat MG is composed of discrete subregions.
Effects of Colchicine on the Formation and Looping of the Tubular Heart of the Embryonic Chick
Authors: Icardo J.M. , Ojeda J.L.
Published: July 2008

The role of microtubules in the early development of the chick embryo heart was studied. The microtubules were disrupted by treatment of the embryos with colchicine. The embryos were divided for study into three groups: (I) before the fusion of the paired cardiac primordia; (II) before the starting of the cardiac loop, and (III) during the formation of the looping process. Colchicine did not impair the fusion of the paired heart primordia nor the acquisition of an asymmetric C-shaped form. However, the normal counterclockwise movement of the heart loop was prevented. From these results we conclude that the formation of the tubular heart and its looping are independent of the integrity of the microtubular system. Under the effects of colchicine the developing myocytes rounded up bulging into the pericardial cavity. The cell contours became scarcely discernible and the individual cell surfaces gave rise to blebs and ruffles of different sizes. In older embryos, clefts of different sizes appeared between the myocardial cells. The effects of colchicine on the pulsatile activity of the heart were recorded. These effects, as well as those on the cell surface characteristics, were found to be age dependent. The more mature the hearts were, the more resistant to colchicine they became. The developmental significance of the results reported here is discussed.
Some New Findings about Hofbauer Cells in the Chorionic Villi of the Human Placenta
Authors: Demir Ramazan , Erbengi Türkân
Published: July 2008

The cytological structure of the Hofbauer cells was investigated in human placentas of the first and second trimesters of gestation. These cells are found in the stromal channel system of the chorionic villi core. Their walls, which are supported by collagen fiber bundles, are produced by reticulum cells and fibroblasts. The cytoplasmic processes of the Hofbauer cells are in contact with the walls of the channels without being associated with them by desmosomal complexes. Some of these cells have features in common with macrophages, such as cytoplasmic processes, larger vacuoles, many pinocytotic vesicles and intracytoplasmic granules. This system of vacuoles and vesicles enables micropinocytotic activity and phagocytosis. This type of Hofbauer cell resembles the typical macrophages. These cells may play a role in the regulation of stromal water content, transportation of ions and the flow of interstitial fluid. The most original finding of this study are long tubes observed in some Hofbauer cells and extending between the nucleus and the extracellular ground substance through the cytoplasm. One of these tubular formations resembles a cilium in structure with three limiting membranes and is filled with a slightly electron-dense substance. This type of Hofbauer cell may transport information between the nucleus and the extracellular ground substance by means of these tubular structures.
Ultrastructural Studies of Initial Stages of Mineralization of Long Bones and Vertebrae in Human Fetuses
Authors: Ben Hur H. , Ornoy A.
Published: July 2008

We studied 27 embryos of 5–12 weeks gestational age where pregnancy was interrupted due to paramedical reasons, in order to find the developmental stages at which matrix vesicles appear in cartilage, and whether they are involved in the mineralization process. Specimens of long bones, lumbar and thoracic vertebral column were prepared for light, transmission and scanning electron microscopic studies. In the cartilaginous models of long bones, matrix vesicles were found amongst maturing and hypertrophic chondrocytes already by the 6th week after fertilization. By that stage, bone rudiments consisted of only cartilage that was not yet mineralized. In the vertebral column matrix, vesicles were found in the vertebral bodies amongst maturing and hypertrophic chondrocytes at the beginning of the 8th week. At that stage, although hypertrophy of chondrocytes was observed, mineralization was still absent. No matrix vesicles were found in the perichondrium, investing mesenchyme and intervertebral discs. Mineralization of cartilage in long bone rudiments started in the form of hydroxyapatite crystals within or around the matrix vesicles at 7 weeks of age and in the vertebral column at 11 weeks. As mineralization progressed, more hydroxyapatite crystals were observed around the matrix vesicles, forming typical calcospherites. Mineralization then progressed in the form described in other animals.
Ultrastructure of Aging Human Umbilical Artery and Vein
Authors: Takagi Toshiro , Toda Takayoshi , Leszczynski Dennis , Kummerow Fred
Published: July 2008

Qualitative and quantitative changes in the human umbilical artery and vein were observed in 15 human specimens at different stages of development. Features such as intimal thickening and cellular lipid accumulation were found in umbilical vasculature. Cellular origin and quantification of lipid-containing cells were determined by electron microscopy. Within 1 month after birth, lipid-containing cells originating from macrophages were observed in the umbilical artery, while those originating from smooth muscle cells were observed in both the umbilical artery and vein. Lipid droplet formation appeared to be independent and different in macrophages and smooth muscle cells; the former cells were stimulated to produce lipid droplets primarily by plasma insudation and the latter cells primarily by hypoxia. These findings indicate that ultrastructural changes observed in closing umbilical vasculature may closely parallel and serve as a model for atherosclerotic changes which occur in mature vessels.
Comparison of Accessory Olfactory Bulb Volumes in the Common Tree Shrew (Tupaia glis)
Authors: Frahm Heiko D. , Stephan Heinz , Baron Georg
Published: July 2008

The volume size of the accessory olfactory bulb (AOB) of 40 common tree shrews (Tupaia glis) was compared with regard to differences between left and right sides, males and females, and animals born in the wild and those born and raised in captivity. There were no statistically significant differences between the two sides and the two sexes, but a significant reduction of the AOB from wild to captive animals was apparent. This reduction was more pronounced in females than in males and somewhat more pronounced in the inner granular layer (layer 6) than in the other measured components (layers 1 + 2, layers 3–5). No well-founded explanation for this reduction could be given.
Structural Components of the Arch of the Foot Analyzed by Radiogrammetric and Multivariate Statistical Methods
Authors: Takai Shozo
Published: July 2008

The structural component of the arches of the human foot were analyzed by a radiogrammetric method and multivariate statistical procedures. The right feet of 101 male university students were radiographed in the standing position from a lateromedial direction. 6 joint heights were measured directly on the radiographs. Factor analysis with varimax rotation showed 3 basic underlying factors for arch heights: (1) calcaneonavicular joint, cuneonavicular joint and first tarsometatarsal joint; (2) calcaneocuboidal joint and 5th tarsometatarsal joint and (3) subtalar joint. The first factor represented the medial longitudinal arch height, the second was associated with the lateral longitudinal arch height. No transverse factor indicating tarsometatarsal or transverse tarsal joints was found. Cluster analysis showed a similar configuration to that in factor analysis. Analysis suggested a key role of the subtalar joint which integrated both the medial and lateral longitudinal arch heights.
Strain-Specific Differences in the Vermian Granular Layer of Albino Rats
Authors: Heinsen H. , Heinsen Y.L.
Published: July 2008

Foliation of the cerebella of Sprague-Dawley rats (strain Han:SPRD) is more advanced than in Wistar rats (strain Chbb:THOM). The differences expressed as length of the granular layer in median sections were significant in lobules Via, VIII, IX and X. The length of the other vermian lobules is generally higher in the former strain. With regard to the volume of the granular layer, the situation is reversed, indicating that the lateral extent and thickness of vermian lobules in Wistar rats (strain Chbb:THOM) is generally larger. These quantitative differences may express differences in cerebellar microcircuitry and fibre connections in the cortex of Wistar and Sprague-Dawley rats.
Venenklappen in den grossen Wurzelstämmen der Vena cava superior
Authors: Anderhuber Friedrich
Published: July 2008

In 97 human cadavers the valves of the following blood vessels were investigated with regard to their cusps and their sizes and positions: the internal jugular veins, the subclavian veins, the brachiocephalic veins, and the superior vena cava. The cusps of each of the valves, which consist of two or three parts, are neither always of equal size nor obligatorily sufficient. Unipartite valves may be sufficient as well as insufficient. Internal jugular veins: The inferior bulb of the internal jugular vein is provided with valves which in 6% of the cases consist of three parts, in 66% of two parts, and in 15% of only one cusp. The concave margins of most of them go down as far as the venous angle. The convex edges attached to the wall of the vein extend to a higher level on the right side than on the left. In 13% there do not exist any valves. Varieties are described separately in this paper.Subclavian veins: Valves are found along the length of the vessel. Only few of them reach the venous angle. In rare cases there exist two valves: one at the beginning, the other at the end of the subclavian vein. In 4% of the cases the valves consist of three, in 75% of two cusps. In 12% they are unipartite. In 9% there are no valves to be found. The right side is more often without valves than the left. Brachiocephalic veins: Only a minority of these vessels is provided with valves. Most of these consist of one cusp, are insufficient, and are situated in the left innominate vein. In the right brachiocephalic vein, which is generally supposed to be valveless, there were found two valves which seemed to replace those of the bulb. Superior vena cava: In only 1 case a valve – unipartite and insufficient – was found in the superior vena cava close to its opening into the right atrium.
The Role of Cartilage Canals in the Ossification of the Talus
Authors: Agrawal P. , Atre P.R. , Kulkarni D.S.
Published: July 2008

Interrupted serial sections of the foot region from 14 human fetuses, crown-rump (CR) lengths between 32 and 240 mm, were studied, using HE, PAS, Alcian blue, Gomori’s trichrome and von Kossa stains. Cartilage canals carrying vascular connective tissue from the perichondrium entered the talus by 68-mm. The centre of ossification developed in the neck region of the talus cartilage by 240 mm CR length, but early stages of chondrocyte proliferation and hypertrophy were noted by 108-mm CR length. The latter is marked by 170 mm CR length. A number of cartilage canals were observed around the developing centre. Branches from these cartilage canals appeared to supply vascular osteogenic tissue to its marrow spaces.
The Rat as an Animal Model for the Study of Senile Idiopathic Osteoporosis
Authors: Simon Mark R.
Published: July 2008

Bone robustness of the major limb bones of 2-year-old and 3-year-old male Sprague-Dawley rats was determined and compared to that of 3-month-old male Sprague-Dawley rats. The results were compared to the published data on two different breeds of laboratory rats to ascertain if the laboratory rat is an appropriate animal model for the study of senile idiopathic osteoporosis in humans. The results show that the limb bone that becomes the most osteoporotic is the male Sprague-Dawley tibia. If one were selecting for the most appropriate breed of rat, it would be the Buffalo rat.
Scanning Electron Microscopic Observations on the 9-Day Opossum (Didelphis virginiana) Embryo
Authors: Krause William J. , Cutts Harry
Published: July 2008

All three germ layers are present in the opossum embryo by the 9th prenatal day. The embryo proper is part of, and continuous with, the remainder of the chorionic wall. The wall of the yolk sacchorion away from the embryo consists only of an outer covering of ectoderm and an inner layer of endoderm. Ectodermal cells covering the neural folds have dome-shaped apices and often show large, bleb-like expansions. Microvilli are short and few in number. The apical surfaces of ectodermal cells that overlie the parietal mesoderm are relatively smooth and show scattered, short microvilli that tend to be concentrated at cell junctions. The apices of ectodermal cells that cover the extraembryonic region are more rounded, and the cells balloon from the surface. Each cell shows abundant elongate microvilli and occasional cytoplasmic blebs. Endodermal cells that line the chorion and form the third (innermost) layer of the embryo are similar in their surface morphology.
Anatomy and Histology of the Cervix uteri of the Ewe: New Insights
Authors: Moré J.
Published: July 2008

The gross and microscopical anatomy of the cervix uteri of the ewe has been studied in an attempt to provide a three-dimensional description of the cervix as it relates to the histological appearance cervical tissue sections. Casts of the inside of the cervical lumen show its convoluted structure consisting of six circular folds, the second fold being eccentric to the other concentric folds and acting as a physiological barrier. Previous histological descriptions of the ovine cervix have failed to provide a clear understanding of the complex structure of its wall. The cervical wall of the ewe comprises five defined layers. The structure of the circular folds is comparatively simple as they consist only of the two deeper layers.
Immunocytochemical Localization of Serotonin-Like Immunoreactivities in the Ciliated Epithelium of the Frog Palatine Mucosa
Authors: Maruyama I. , Shioda S. , Nakai Y.
Published: July 2008

Immunocytochemical localization of serotonin (5-HT)-like immunoreactivities was studies in the ciliated epithelium of the frog palatine mucosa by the peroxidase anti-peroxidase (PAP) method. 5-HT-like immunoreactivity was found only in the small granular vesicles (100–150 nm in diameter) and not in any mature large secretory granules or in other cell organellae in the goblet cells. No 5-HT-like immunoreactivities were found in any other epithelial and secretory cells in the palatine epithelium. It appears therefore that 5-HT-like immunoreactive granular vesicles have certain physiological effects on the ciliary movement of the ciliated cells or in the goblet cells.
The Effects of Quantified Amounts of Increased Intermittent Compressive Forces for 30 and 60 Days on the Growth of Limb Bones in the Rat
Authors: Simon Mark R. , Holmes Kenneth R. , Olsen Aart M.
Published: July 2008

The purpose of this study was to subject groups of rats each to a specific 10% increase in body weight, to a maximum of a doubling of body weight, to study the effects of quantified, increased, intermittent, compressive forces on limb bone growth. Chronic centrifugation was employed. 21-day-old male Sprague-Dawley rats were used. After 30 and 60 days of centrifugation, the rats were killed. The humerus, radius, ulna, femur, and tibia were removed from each animal, cleared of all soft tissues, measured and weighed. The data were corrected for differences due to individual body weight by dividing bone lengths by the cube root of the body weight of the same animal. Tukey’s ‘Studentized’ Multiple Range Test was performed to identify aggregations (sets) of force groups between which there are significant differences. The data suggest that the value of g, together with the amount of time spent at centrifugation, are both significant factors in the effects of increased intermittent, compressive forces, produced by simulated increases in body weight, on limb bone growth.
Fine Structure of Hepatocytes from Mini-Pigs and Mini-Pig Fetuses Exposed to Alcohol (Ethanol) in vivo
Authors: Rømert Paul , Matthiessen Martin E.
Published: July 2008

The effect of alcohol on hepatocytes from pregnant mini-pigs and their half-term fetuses was studied after addition of 100–300 g ethanol daily to the ordinary sufficient fodder for about 20 days. Well-defined areas of liver tissue from ethanol-exposed mini-pigs and their fetuses were immersion fixed. The hepatocytes were evaluated ultrastructurally and compared to hepatocytes of non-treated control animals. After exposure to ethanol the hepatocytes of the pregnant mini-pig developed an extensive smooth endoplasmic reticulum, and showed an increased number of mitochondria, microbodies and autophagic vacuoles, extensive Golgi complexes with accumulation of secretion, and a reduction of glycogen. The hepatocytes of the half-term fetuses exhibited profound changes of mitochondria and endoplasmic reticulum after alcohol exposure. Many mitochondria showed abnormal shape and increased size, disorientation of cristae and accumulation of paracrystalline material. An increased number of autophagic vacuoles containing remnants of mitochondria were observed. The granular endoplasmic reticulum exhibited aggregations of endoplasmic cisternae which were well defined and not bounded by a membrane. Thus, the ultrastructural changes in the hepatocytes of the pregnant mini-pig seem to indicate an adaptation of these cells to ethanol by development of a microsomal or catalase ethanol-oxidizing system, while the hepatocytes of the mini-pig fetus in contrast show obvious signs of cellular injury.
Cell Proliferation in the Principal Target Organs of the Dog (Beagle) Ovary during Various Periods of the Estrous Cycle
Authors: Spanel-Borowski Katharina , Schmalz Veronique , Thor-Wiedemann Sabine , Pilgrim Christoph
Published: July 2008

Cell proliferation in the principal target organs of the ovary was studied in 7 beagle dogs during proestrus, early estrus, secretory and regressive metestrus. Pulse labelling with (3H)-thymidine and autoradiography were applied and labelling indices were determined. Organs with squamous and with glandular epithelium except the mammary gland showed a proliferation peak during early proestrus, the incidence of labelling being higher in organs with squamous epithelium. During early proestrus the intensity of labelling decreased in organs with squamous epithelium in the following order: vulva, vagina, portio vaginalis, and portio supravaginalis. At this time cell replication was higher in the superficial glands of the cervix and corpus uteri as well as the circular layer of the myometrium compared with values from the basal glands or the longitudinal layer. The steepest decline of the proliferative activity occurred between the proestrous period. While some labelled cells were observed during secretory metestrus, labelling was almost absent during regressive metestrus. By contrast, the mammary gland began to develop at the periovulatory period and was at the height of its proliferative activity during secretory metestrus. It is concluded for species with a long estrous cycle that: (1) the rate of cell replication in the vulva, vagina, uterus and oviduct is at its peak at the beginning of the estrous cycle and declines during proestrus; (2) as compared to observations in species with short estrous cycles, cell proliferation is very low during metestrus.