bluuebunny/crossref_metadata_2025 huggingface dataset:
Motor Components of the Trigeminal Nerve and Organization of the Mandibular Arch Muscles in Vertebrates
Authors: Song J. , Boord R.L.
Published: July 2008

The peripheral branching pattern of the mandibular ramus of the Vth cranial nerve and the organization of the trigeminal motor column are highly conserved in craniate phylogeny regardless of the vast modifications in attachments and structure of the mandibular arch musculature. Proximal, intermediate and distal series of mandibular nerve branches supply three major muscle groups and are in register with three neuronal populations of the trigeminal motor column. The adult branching pattern is established in response to the differentiation of mandibular muscles and is important in determining the organization of the motor nucleus of V. The innervation of the muscles of the mandibular segment of the head, and the location of motoneurons reflect their segmental origins and are reliable criteria for homologizing mandibular muscles among the craniates.
A Study of Early Fetal Growth Patterns in Twin Pairs
Authors: Iffy L. , Jakobovits A. , Lavenhar M.A. , Najem R. , Hopp L. , Jakobovits A.A.
Published: July 2008

The relationships of sitting heights and body weights of fetal twin pairs were analyzed in comparison with established growth rate standards of singleton fetuses. The apparent rate of growth of individual twins scattered around the average growth curve in the same manner as singletons. In contrast, members of 12 twin pairs with <125 mm sitting heights, were closely similar in terms of bodily dimensions. Among the 7 pairs with crown-rump lengths of >125 mm, 4 were discordant, suggesting a deceleration of growth in one of the twin fetuses, starting after the 18th week of gestation.
Morphometric and Stereological Study of the Glandular Epithelium of the Seminal Vesicle of Castrated Guinea Pigs Treated with 17β-Oestradiol Benzoate
Authors: Tam C.C. , Wong Y.C.
Published: July 2008

Morphometric and stereological data are presented showing that the average thickness of the glandular epithelium (including secretory and basal cells together with intercellular spaces) of the seminal vesicle of the guinea pig increased significantly after oestradiol administration when compared with castrated controls. The increase in thickness was accompanied by a significant increase in the volume density of intercellular spaces. There were significant decreases in volume, surface and numerical densities of the secretory cell nuclei with respect to the glandular epithelium. The increase in the volume and surface densities of the secretory cell nuclei with respect to the average secretory cell was due to the significant increase in the average volume of the secretory cell. The increase in the mean volume of secretory cells was the result of a significant increase in the average cytoplasmic volume. In comparison with castrated controls, the structural data of cytoplasmic organelles also showed significant increases in total volume and surface area of granular endoplasmic reticulum per average secretory cell following oestradiol administration. This was accompanied by a significant increase in the total volume of Golgi cisternae per cell. The increase in the cytoplasmic volume of secretory cells after oestradiol treatment may be the result of an increase in number of organelles responsible for protein synthesis. The present study has provided quantitative evidence that the secretory function of the seminal vesicle of castrated guinea pigs may have been stimulated after oestradiol administration, which cannot be easily detected in a qualitative manner.
Morphology and Stereology of the Female Canine Urethra Correlated with the Urethral Pressure Profile
Authors: Augsburger H.R. , Cruz-Orive L.M. , Arnold S.
Published: July 2008

Perfusion-fixed urethrae of five sexually intact nulliparous female beagles in anestrus, between 2 and 3 years of age, were morphologically and morphometrically investigated. Absolute and relative volumes of different tissue components were stereologically estimated per urethral quarter. A discrete smooth muscle sphincter could neither be identified in the bladder neck nor in the urethra. However, the circularly arranged smooth muscle fibers in the proximal half of the urethra were regarded as being capable of sphincteric function. The connective tissue, composed of collagenous and longitudinally orientated numerous elastic fibers, accounted for the most predominant constituent. It comprised 77.3 to 78.2% of the total volume in the proximal three urethral quarters. The vascular plexus was most prominently developed in the proximal two urethral quarters, and its relative and absolute volumes significantly exceeded those of the third quarter. The discovered direct connections between small arteries and the sinusoids of the vascular plexus emphasize its importance as a major contributory component to urinary continence. The striated musculus urethralis was essentially confined to the distal half of the urethra and most strongly developed in the fourth quarter, where it surrounded the urethra transversely at its ventral and lateral aspects. The caudal muscle fibers continued dorsally to the vagina. A transitional epithelium bounded the urethral lumen. Its superficial cell layer progressively flattened towards the external urethral orifice, changing into a stratified squamous lining as also seen in the vestibulum. Recorded pressures, or pressure changes, could neither be correlated with volumes nor with morphology of particular tissue elements in the different urethral quarters.
Cytoarchitecture of the Common Tree Shrew (Tupaia glis) Superior Cervical Ganglion
Authors: Chunhabundit P. , Thongpila S. , Cherdchu C. , Somana R.
Published: July 2008

The cytoarchitecture of the superior cervical ganglion of the common tree shrew was investigated by scanning electron microscopy using the vascular cast technique in conjunction with digestion by collagenase-hyaluronidase/HCl. The main cellular constituents were found to be multipolar neurons that were densely distributed throughout the ganglion. These neurons were covered with a smooth cytoplasmic sheath of satellite cells. After the removal of this sheath by digestion of increased duration, the blebs or knobs on the neuronal surfaces became evident. A meshwork of nerve fibers over the surface of neurons was also observed. Preganglionic sympathetic nerve fibers, giving rise to fine branches that ran toward the postganglionic sympathetic neurons before forming synapses, were demonstrated. Groups of neurons surrounded by capillary loops were also frequently observed.
Commemorating the Fabrica of Vesalius
Authors: O'Rahilly R.
Published: July 2008

It is an appropriate time to commemorate the Fabrica of Andreas Vesalius, which was published in Basel 450 years ago. In addition, a dozen key references in English (books and articles) are listed for those who wish to learn more about Vesalius and particularly concerning the wonderful woodcuts in the Fabrica.
Structural Development in the Newborn Marsupial, the Stripe-Faced Dunnart, Sminthopsis macroura
Authors: Gemmell R.T. , Selwood L.
Published: July 2008

The structure of various sense organs and endocrine glands was examined in the stripe-faced dunnart, Sminthopsis macroura. This marsupial has the shortest gestation known for all mammals, 10.5–11 days. The morphology of the anterior pituitary, adrenal gland, olfactory epithelium, Merkel cells around the mouth and the utricle of the vestibular system of S. macroura was similar to that observed in other newborn marsupials. These structures are thought to be required by the newborn to transfer from the uterus to the pouch. The stage of development of the urinary system, the semicircular canals of the vestibular system, eyes and lungs was slightly different to that of other newborn marsupials. These structures are thought to have secondary importance in allowing the newborn to reach the teat. Although marsupials display variation in gestation length and produce newborn of differing body weights, there is little difference in morphology between various newborn marsupial species
Development of the Lens in Human Embryos: A Histochemical and Ultrastructural Study
Authors: Oguni M. , Setogawa T. , Otani H. , Hatta T. , Tanaka O.
Published: July 2008

The early development of the lens was examined, using 36 externally normal human embryos at Carnegie stages 13–23 (4 to 8 weeks of gestation). Twenty-two embryos were sectioned serially and stained with periodic acid-Schiff and a modified method of PAS. In 14 embryos, not only the differential distribution of glycogen but also the ultrastructural change in the developing lens, with special reference to junctional complexes, were examined electron microscopically. At stage 15, when the lens vesicle was formed, glycogen was observed in the cytoplasm of the lens epithelium, especially in the posterior lens epithelium. From stages 16 to 18, when the posterior lens epithelium was differentiated into the primary lens fibers and elongated toward the anterior lens epithelium, the amount of glycogen increased in the basal cytoplasm of the primary lens fiber, where the intracellular organelles, such as the tubular vesicles, mitochondria and multivesicular bodies, began to aggregate. At stage 20, when the lens cavity was obliterated, glycogen was also present in the anterior lens epithelium. At stage 21, as the formation of the secondary lens fibers proceeded, glycogen was noted in the secondary lens fibers in the equator region. These findings suggest that the distribution of glycogen is associated with the formation of the primary and secondary lens fibers. In addition, we provide additional information that a lot of glycogen is distributed in the region where many intracellular organelles aggregate in the embryonic lens vesicles.
Magnetic Resonance Imaging of the Submandibular-Sublingual Complex
Authors: Sbarbati A. , Baldassarri A. , Leclercq F. , Merigo F. , Antonakis K. , Boicelli A.
Published: July 2008

The submandibular-sublingual complex (SSC) was studied in vivo by magnetic resonance imaging (MRI) at 4.7 and 7.05 Tesla in rat and mouse. A correlation was found between histology and MRI signal. The mainly mucous sublingual gland emitted a more intense signal than the mainly serous submandibular gland. Ventral to the glands, cutis, subcutaneous adipose tissue and two planes of muscular tissue separated by connective laminae were visible in vivo. Autopsy and histology confirmed the in vivo description provided by MRI. The reactivity of the salivary system after pharmacological stimulation was studied in mice at 7.05 Tesla. Stimulation of salivary secretion by pilocarpine nitrate injected in the subcutaneous space ventrally to the SSC resulted in an augmentation of the salivary liquid visible in the oral cavity by MRI. The diffusion of pilocarpine nitrate in the connective tissue located ventrally the SSC and in the glandular parenchyma was also followed in vivo. These results show that MRI is a potentially useful tool for studying the salivary glands in vivo.
The Course of the Right Recurrent Laryngeal Nerve within the Vagus Nerve of the Rat
Authors: Stathakis P. , Fernando D.A. , Lord R.S.A.
Published: July 2008

The course of the right recurrent laryngeal nerve (RLN) within the vagus nerve was examined under the light microscope, using horseradish peroxidase. In the higher cervical vagus, i.e. from the base of the skull to the level of the carotid bifurcation, the recurrent laryngeal nerve fibres formed on average 5-6 small separate bundles (15–40 µm in diameter); in the middle cervical vagus, on average from the level of 8-14 mm caudally from the bifurcation, there were fewer bundles with a diameter range of 10-50 µm; in the lower cervical vagus, indicated as being from 14-26 mm caudally from the middle cervical vagus, the bundles merged into a single larger bundle (50–70 µm).
Glycoconjugate Expression during Drosophila Embryogenesis
Authors: Fredieu J.R. , Mahowald A.P.
Published: July 2008

Glycoproteins and other glycoconjugates present on the surface of many cell types have been identified and assigned various functions. The extent of variation possible in complex glycan structures and the heterogeneity of glycoconjugate expression between two apparently similar cells has been demonstrated previously by using plant lectins to survey developmental biological models. To examine the array and extent of glycoconjugate roles in embryonic Drosophila neurogenesis, we have used plant lectins to characterize lectin receptor molecules present on the neuronal and non-neuronal cell surfaces during critical stages in axonogenesis and axon fascicle development. A collection of lectins representing a variety of hapten monocarbohydrate specificities uncovered a complex expression pattern in many glycan structures. D-Galactose-specific lectins, Bauhina purpura agglutinin (BPA) and Arachis hypogea agglutinin (peanut agglutinin, PNA), and a D-galactose/N-acetylgalactosamine-specific lectin, Glycine max agglutinin (soybean agglutinin, SBA), all recognized the surface of most cultured neurons and their axons. In the intact embryo, only the PNA and BPA receptors were found on neurons of the central and peripheral nervous systems, while SBA recognized cells of structures other than the nervous system. All three lectins recognize a high molecular weight glycoprotein when used to precipitate lectin receptor from culture homogenates. Results suggest the presence of lectin receptor glycoproteins at temporally and spatially important positions within the embryo and in culture. These glycoproteins may provide functions critical in establishing the final phenotypes of specific cells through either axon guidance/target acquisition or morphogenic adhesive events.
Ultrastructure of the Epithelium That Lines the Ductuli efferentes in Domestic Equidae, with Particular Reference to Spermatophagy
Authors: Arrighi S. , Romanello M.G. , Domeneghini C.
Published: July 2008

The epithelium that lines the ductuli efferentes in the horse, donkey and mule has been examined by electron microscopy. The epithelium consists of columnar ciliated and non-ciliated cells. Lymphocytes and macrophages are also present, together with cells that are rich in lipofuscin. These ‘lipofuscin-rich’ cells are a peculiar feature of the excurrent ducts of Equidae and are characterized by a large number of highly heterogeneous residual bodies. The general morphology of the epithelium and, in particular, of the non-ciliated cells implies that the epithelium is involved in the absorption and digestion of luminal fluids. This morphology includes a complex endocytotic apparatus as well as a large and heterogeneous population of lysosomal structures within the cytoplasmic domain. Of particular interest is the unusual presence of peroxisomes. In the Equidae, the cells that compose the epithelial layer appear to act directly on the germinal cells, via the process of spermatophagy. The presence of peroxisomes in non-ciliated cells has been implicated in endocytotic and spermatophagic activities, and peroxisomes may be involved in the oxidation and elimination of toxic peroxides.
Origin, Course and Distribution of the Superior Gluteal Nerve
Authors: Akita K. , Sakamoto H. , Sato T.
Published: July 2008

Ten pelvic halves of six Japanese male cadavers were dissected in order to obtain precise anatomical knowledge of the course and distribution of the superior gluteal nerve. The more anterior parts of the glutei medius and minimus, innervated by branches of the superior gluteal nerve, were revealed to originate more cranially, and the tensor fasciae latae was innervated by the cranialmost element of the nerve. Based on these findings, it might be proposed that the course and distribution of the superior gluteal nerve are directly influenced by the anterior rotation of the gluteus medius.
An Ultrastructural Study of the Fibromuscular Capsule of the Corpus luteum in Mice
Authors: Motta P.M. , Vizza E. , Correr S. , Macchiarelli G. , Familiari G. , Muglia U.
Published: July 2008

The presence and distribution of contractile cells in mature corpora lutea (CL) of pregnant and normal cycling mice were studied by transmission (TEM) and scanning (SEM) electron microscopy. In the connective tissue surrounding the CL, SEM observations made after maceration in alkali, revealed long, flat, spindle-shaped elements arranged parallel to each other, forming a continuous capsule. TEM of these elements revealed ultrastructural features of mature smooth muscle cells (SMC), as well as structures intermediate between fibroblasts, fibrocytes and SMC. Discrete bundles of SMC were seen to exit the external capsule of the CL and to penetrate the luteal tissue. The extensive branches of these bundles of SMC appeared to make contact with numerous vessels. Therefore, three-dimensional reconstruction, based on TEM and SEM analysis, revealed that the SMC of the CL were organized such that they form a wide fibromuscular skeleton around and within the luteal mass. It is possible that pulsatile or tonic contraction of this structure may help to regulate the secretory activity of the luteal tissue by modifying the pressure inside the CL.
Unilateral Persistence of the Dorsal Ophthalmic Artery in Man
Authors: Pretterklieber M.L. , Schindler A. , Krammer E.B.
Published: July 2008

The left ophthalmic artery (OA) of a Caucasian male originated from the transverse portion of the cavernous part of the internal carotid artery (ICA), indicating the persistence of a dorsal OA. It entered the orbit through the most medial part of the superior orbital fissure, close to the medial aspect of the ophthalmic nerve. In the orbital cavity, the OA crossed above the optic nerve to reach the medial wall of the orbit. At the medial end of the upper eyelid it anastomosed with the angular artery and thereafter divided into the dorsal nasal and supratrochlear arteries. Whereas the right OA did not present any irregularities, some additional anatomical variations, above all a bilateral pterygospinosus muscle, were found in this individual. Since except the existence neither the course and branching pattern of a persistent dorsal OA nor its occurrence together with other varieties have been previously reported in man, phylogenetic and ontogenetic aspects of this aberrant vessel are discussed.
Visualization of Neonatal Anatomy and Pathology with a New Computerized Three-Dimensional Model as a Basis for Teaching, Diagnosis and Therapy
Authors: Richter E. , Krämer H. , Lierse W. , Maas R. , Höhne K.H.
Published: July 2008

A new computerized three-dimensional (3D) volume model derived from a postmortem MRI series of the chest and abdomen of a human newborn allows interactive dissection by removing, adding organs or cutting in unlimited directions. The advanced technique of real volume visualization instead of using contours allows one to study the normal and pathological anatomy of the neonate. Anatomical details of the pleural, pericardial and peritoneal cavities and of abdominal veins are demonstrated. Compared to conventional methods, the advantages of this model for teaching and as a basis for diagnostic imaging and therapeutic procedures are evident.
Demonstration of Atrial Natriuretic Peptide Immunoreactivity and Ultrastructurally Related Secretory Granules in Myoblasts of the Chick Myotome
Authors: Santander González , Lobo Toledo , Alonso Martinez , Cuadrado Martinez , Casco V.H. , Paz D.
Published: July 2008

In this study, an ultrastructural and immunohistochemical examination was carried out on the presence of an ‘atrial-natriuretic-peptide (ANP)-like factor’ in the myoblasts of the brachial myotome of chicken embryos at Hamburger and Hamilton stages 17 ± to 19. The results of the immunohistochemical study indicate that, at these stages of their development, the myoblasts of the brachial myotome show ANP immunoreactivity. The ultrastructural analysis of the myoblasts shows the presence of ‘granules’ or ‘secretory vesicles’, similar to the secretory granules which contain natriuretic peptides. The demonstration of immunoreactivity to ANP in the myotome and the specific localization of secretory vesicles in myoblasts, as the first evidence relating ANP with skeletal muscle development, reveal a new site at which an ANP-like factor may be synthesized. The hypothesis of a paracrine and/or autocrine function(s) during myogenesis is suggested.
Development of the Human Gigantocellular Reticular Nucleus: A Morphometric Study
Authors: Yamaguchi K. , Goto N. , Honma K.
Published: July 2008

The cytoarchitectonic development of the human gigantocellular reticular nucleus (GRN) was studied quantitatively in 15 fetuses (16–39 weeks of gestation: WG) and in 2 adults (16 and 85 years old). With microscopic observation on serial celloidin sections of the brain, we measured them to obtain the following morphometric parameters: numerical density (ND), profile area (PA), and perimeter (PL) of the GRN neurons. GRN appeared as early as 16-18 WG, but most neurons were still immature and the cell nucleus was relatively large (nucleo-cytoplasmic ratio was high), although a few large neurons containing fine Nissl bodies were observed. Typical, coarse Nissl bodies of large multipolar neurons were first recognized at 21 WG. The earliest myelination was noticed at 22-23 WG, but myelinated nerve fibers were not prominent until the late fetal period. ND was largest at 16 WG and decreased rapidly with gestational age (coefficient of correlation, r = –0.85): it was reduced to about 10% of that at 16 WG by the end of the fetal period. ND was smaller in the adults than in the fetuses. Average PA increased monotonously with gestational age (r = 0.79). The coefficient of variation (CV) of PA was high early in the fetal period (47–48%: 16–18 WG) and increased gradually with age (r = 0.40). The average circularity ratio (CR = 4πPA/PL2) decreased monotonously with gestational age (r = –0.85), while the CV of CR increased (r = 0.76). In conclusion, this study suggests that immature GRN neurons may appear by 16 WG after migration and that the subsequent differentiation and maturation may progress gradually and monotonously during the later half of gestation.
Motoneurons Innervating Two Regions of Rat Medial Gastrocnemius Muscle with Differing Contractile and Histochemical Properties
Authors: Vanden Noven S. , Gardiner P.F. , Seburn K.L.
Published: July 2008

The medial gastrocnemius (MG) muscle, which receives its innervation by two extramuscular nerve branches, is representative of muscles which show a particular form of muscle compartmentalization (i.e. a regional specialization of muscle fibers) in which there is a ‘deep’ oxidative region and a ‘superficial’ low-oxidative region. Differential recruitment of motor units from these two regions of the MG has been reported for different functional tasks. Our goal was to determine if the organization of the MG motoneuron pool-muscle complex with its two extramuscular nerve branches could account for the phenomenon of regional specialization of muscle fibers. The two extramuscular nerve branches innervated muscle subvolumes which differed in contractile properties and fiber type percentages. The MG proximal nerve branch (NBr) innervated mostly high-oxidative and slow fibers, but with some low-oxidative fast fibers. The distal NBr innervated mostly low-oxidative fibers, but also a small proportion of high-oxidative and slow fibers. These results suggest that the two nerve branches do not strictly define a superficial/deep organization of fiber types in the MG. The number and soma size characteristics of motoneurons supplying the two extramuscular nerve branches showed that the motoneurons innervating the deep more oxidative muscle region, supplied by the proximal NBr, were smaller than those innervating the superficial, primarily low-oxidative, region supplied by the distal NBr. Our findings indicate that the MG motoneuron pool-muscle complex of the Sprague-Dawley rat will lend itself to studies of how the various motor unit types within a given spinal motor complex adapt to different conditions (e.g. aging, disease, injury, exercise).
Anatomical Observations on the Musculi suprahyoidei and Apparatus hyoideus with Special Reference to the Musculus jugulohyoideus and Os stylohyoideum of the Mouse, Hamster and Rat
Authors: Aikawa M. , Shimozawa A.
Published: July 2008

The musculi suprahyoidei and apparatus hyoideus were investigated using a combination of gross dissection and histological techniques in the mouse, hamster and rat. The new findings with regard to these are as follows: (1) the musculus jugulohyoideus, which runs from the processus jugularis to the os stylohyoideum, exists in the mouse and hamster, but is absent in the rat; (2) the m. jugulohyoideus is innervated with the ramus jugulohyoideus from the nervus facialis; (3) the os stylohyoideum and the os tympanohyoideum exist on the lateral surface of the bulla tympanica in the mouse, hamster and rat, and (4) four kinds of muscle (m. stylohyoideus, m. styloglossus, m. stylopharyngeus, m. jugulohyoideus) attach to the os stylohyoideum in the mouse and hamster; however, no muscles attach to the os stylohyoideum in the rat.
Study of Pterygospinosus Muscle in Human Fetuses
Authors: Mérida Velasco J.R. , Rodríguez Vázquez J.F. , Arraez Aybar L. , Jiménez Collado J.
Published: July 2008

The arrangement of the pterygospinosus muscle was analyzed in 5 human fetuses. The pterygospinosus muscle extends from the posterior border of the lateral lamina of the pterygoid process to Meckel’s cartilage. Such an arrangement would permit its action on the joint formed by Meckel’s cartilage and the incus of the middle ear. The pterygospinosus muscle is a remnant of the masticatory muscle group. The relationships of the pterygospinosus muscle with the mandibular nerve and its branches and the maxillary artery and its branches were analyzed.
High Division of the Axillary Artery
Authors: Ozan H. , Şimşek C. , Önderoǧ;lu S. , Kurici Y. , Başar R.
Published: July 2008

A case is presented here in which the axillary artery divided into two branches, the lateral branch being situated more deeply with respect to the medial branch. The superficial branch gave rise to only thin muscular branches in the arm and coursed along the ulnar artery in the forearm but did not provide the branches which should arise from this artery. On the other hand, the deeply coursing artery provided the branches of the brachial artery in the arm and from the cubital fossa downwards it provided the branches which normally arise from the ulnar artery.
The Nasal Respiratory Epithelium in the Human Fetus: Lectin Histochemistry
Authors: Gheri Bryk S. , Gheri G. , Sgambati E. , Balboni G.C.
Published: July 2008

Lectin binding histochemistry was used to investigate the glycoconjugate saccharidic moieties in the respiratory epithelium of human fetuses ranging in age from the 8th to the 12th week of gestation. The distribution and changes in the sugar residues of the glycoconjugates at the level of the basal cells, the bathyprismatic cells and the bathyprismatic ciliated cells are reported. PNA and SBA allowed the identification of some ‘elongated cells’, which were characterized by lectin-reactive supranuclear granules. These epithelial cells, which have not previously been identified using conventional histochemical methods, might be the precursors of secretory cells.
Glycosaminoglycan Synthesis in the Mandibular Condyle during Growth Adaptation
Authors: Kantomaa T. , Pirttiniemi P. , Tuominen M. , Poikela A.
Published: July 2008

Condylar growth was studied after an operation simulating functional orthodontic appliances. Twenty-five rabbits underwent a surgical operation for the induction of premature synostosis to displace the glenoid fossa posteriorly during growth. Twenty-five control rabbits underwent sham operations. At the age of 15 days, 10 experimental and 10 control animals and, at the age of 20 days, 5 experimental and 5 control animals were killed. Their mandibular condyles were organ-cultured for 3 h in the presence of radiolabelled sulphur. The condyles were used for autoradiographic purposes. Digital image analysis of autoradiograms of histological sections showed synthesis of glycosaminoglycans to have increased from the anterior to the posterior direction. This increase was more marked in experimental animals than in the condyles of control animals. Ten experimental and 10 control animals were killed at the age of 15 days, and mandibular condyles were organ-cultured for 1, 4 and 7 days. Differentiation of proliferating prechondroblasts into hypertrophied chondrocytes continued under organ culture conditions. A marked decrease in the proliferating cell layer was noticed, especially in control condyles. Hypertrophy was faster and came closer to the surface of the condyle in the anterior region of the condyle. This was most marked in the condyles of experimental animals. The results indicate that a procedure carried out on the glenoid fossa with the same effect as functional appliances increases the synthesis of extracellular matrix in the posterosuperior region of the mandibular condyle.
The Development of Molecular Compartmentation in the Cerebellar Cortex
Authors: Hawkes R. , Mascher C.
Published: July 2008

The cerebellum is subdivided into hundreds of discrete modules defined by their connectivity and molecular signatures. Cerebellar compartmentation arises very early in development through the formation of multiple populations of chemically distinct Purkinje cells that migrate in a coordinated fashion to form para-sagittal bands of cells. Different Purkinje cell bands are then innervated by discrete subpopulations of cerebellar afferents. Because of its stereotyped and strikingly beautiful organization the cerebellum is an excellent model in which to explore genetic/epigenetic aspects of pattern formation in the central nervous system.
Differentiation of Oxyntic Cells during Early Ontogenesis in the Bovine
Authors: Sommer U. , Kressin M. , Schnorr B.
Published: July 2008

The origin and the differentiation of oxyntic cells in fetal bovine abomasum were investigated using transmission electron and light microscopic methods. In the oxyntic gland region oxyntic cell precursors and immature oxyntic cells appear as early as at the end of the first trimester of gestation – much earlier than described in any other mammalian animal species. Immature oxyntic cells are characterized by long apical microvilli, by their triangular-shaped light cytoplasm rich in large and numerous mitochondria, by the existence of vesicular profiles and by the incipient invagination of the apical plasma membrane forming a primitive intracellular canaliculus expanding into central areas of the cell. The oxyntic cell represents the first exocrine cell type developing from secretory granule-containing cells in the base of the primitive gastric glands.
Lectin-lnduced Deciduoma Formation in the Pseudopregnant Rat
Authors: Shaw T.J. , Murphy C.R.
Published: July 2008

Decidual cell induction in the pseudopregnant rat was examined in this study using the lectin concanavalin A (ConA). The histochemical binding of the lectin to the uterine cell surface at the time of deciduomatic induction was also studied. ConA was found to induce significant deciduomata (decidual-like tissue) in the uterine horn when injected intraluminally on day 5 of pseudopregnancy (PSP). ConA-induced deciduomata appeared as a series of discrete nodules in the uterine horn, reminiscent of the anatomical appearance of normal embryo implantation sites. Deciduoma induction by ConA was greatly reduced by pre-absorption of the lectin with its competitive sugar. Lectin histochemistry revealed binding of ConA to the cell surface on day 5 of PSP. Pre-absorption of the lectin with its competitive sugar also significantly reduced surface binding of the lectin, and this finding may be correlated with the greatly reduced ability of the pre-absorbed lectin to induce deciduomata. Possible mechanisms for the induction of deciduomata by lectins are considered.
Arteriographic Study of the Arterial Supply of the Foot in One Hundred Cadaver Feet
Authors: Hamada N. , Ikuta Y. , Ikeda A.
Published: July 2008

The arterial supply of 100 human cadaver feet (87 cadavers) was investigated by stereoscopic arteriography and was compared phylogenetically to that of the macaque foot. The deep plantar arch was always well developed and complete, whereas the superficial plantar arch was usually slender and incomplete. The first proximal perforating artery arising from the dorsalis pedis artery formed the main component of the deep plantar arch in 82% of the feet. The second proximal perforating artery arising from the dorsal rete contributed to the deep plantar arch in 43% of the feet, and formed most of the arch in one foot. The dorsal rete was classified into four groups of variants based on the arterial source of the second dorsal metatarsal artery. These were the arcuate artery (25%), distal lateral tarsal artery (12%), proximal lateral tarsal artery (6%), and nondorsal rete (57%) variants. In the first intermetatarsal space, the dorsal and plantar metatarsal arteries shared a common trunk in 54% of the feet, but this did not occur in the other intermetatarsal spaces. The second dorsal metatarsal artery arose from the dorsal rete in 43% of the feet, and this artery was quite large, sometimes being the largest of all the dorsal and plantar metatarsal arteries. Variations of the arterial supply found in humans sometimes resembled the typical pattern found in the macaque.
Scanning and Transmission Electron Microscopy of Human Donor Lungs: Fine Structure of the Pulmonary Parenchyma following Preservation and Ischemia
Authors: Fehrenbach H. , Riemann D. , Wahlers T. , Hirt S.W. , Haverich A. , Richter J.
Published: July 2008

In six cases of clinical single-lung transplantation, the contralateral donor lungs were studied by means of scanning (SEM) and transmission (TEM) electron microscopy. SEM and TEM revealed an overall good to excellent preservation of the pulmonary parenchyma. Since the donor double lung blocks, which were preserved by means of pulmonary arterial perfusion with modified Euro-Collins solution, were separated immediately prior to transplantation, transplanted and contralateral lungs had been subjected to identical influences. Comparing the arterial oxygenation achieved in the recipient 6 h after transplantation with the structural data of the corresponding contralateral donor lung, the degree of epithelial alterations appeared to be most important in determing postoperative lung function. Concerning the assessment of the quality of the alveolar epithelium, gradings performed independently by means of SEM and TEM yielded largely corresponding scores, while a significant shortcoming of SEM was the very limited access to the endothelial surface. Taking into account the relevance of epithelial injury in determing postoperative lung function, SEM can provide clinically relevant data more quickly than TEM. To quantify the fine structural alterations of human donor lungs, however, TEM-based morphometry is required.
Formation of the Cervical Flexure: An Experimental Study on Chick Embryos
Authors: Männer J. , Seidl W. , Steding G.
Published: July 2008

It has been proposed that the cervical flexure of vertebrate embryos arises from the normal morphogenesis of the heart. This hypothesis is based on experiments in which the heart tube is removed or disrupted in early chick embryos. It has been reported that, in normal atmosphere, these embryos continued normal morphogenesis except for cervical flexure formation. In the present study, we performed similar experiments. In contrast to previous work, however, only one set of our heart-deprived chick embryos was reincubated in normal air. The other sets were reincubated in oxygen-enriched air. Under normoxia, heart removal resulted not only in prevention of the cervical flexure, but also in mesenchymal defects, and in a remarkable hypoplasia of the craniocervical region. Under hyperoxia, heart-deprived embryos developed no severe mesenchymal defects and the growth of the upper body portion was more normal, with the hypoplasia confined to the cranial region. The formation of the cervical flexure was now normalized. These results show that cervical flexure formation is not directly dependent on normal morphogenesis of the heart, but does depend on a sufficient oxygen supply to the cervical region. During early development, the craniocervical region of a chick embryo is more sensitive to circulatory failure than the trunk.
Ultrastructural Changes in Mitochondria of the Adrenal Cortex of Iron-Deficient Rats
Authors: Coleman R. , Tanne Z. , Nahir M. , Shomrat D. , Miller-Lotan R. , Youdim M.B.H.
Published: July 2008

Male Sprague-Dawley rats aged 3 weeks that were maintained on an iron-deficient diet for 4-5 weeks developed severe anemia with markedly reduced hemoglobin levels (4.11 ± 0.20 Hb g% versus controls 12.74 ± 0.15 Hb g%). On sacrifice, the adrenal glands were removed and processed for light and transmission electron microscopy and enzyme cytochemistry. The major histological and ultrastructural changes in the adrenal cortex in response to the iron deficiency were seen in cells of the zona fasciculata, especially in its outer region, and to a lesser degree in cells of the zona reticularis. Structural changes were seen in the mitochondria of these cells, which often became grossly enlarged and developed unusual electron-dense inclusions. In addition, the lipid droplets in the iron-deficient cells of these regions were much less developed and less prominent compared with controls. Quantitative cytochemical localization of succinic dehy-drogenase (SDH) activity in the adrenal glands showed that in iron-deficient rats there was an increase in SDH activity in the zona fasciculata (46%) and in the zona reticularis (74%), whereas there was a reduction of approximately 41% in SDH activity in the zona glomerulosa. Serum corticosterone levels were significantly raised in the iron-deficient rats compared with the control rats. Our results indicate that severe nutritional iron deficiency in rats causes ultrastructural and cytochemical changes in the mitochondria of the adrenal cortex accompanied by increased secretion of corticosterone.
Association of Neutrophils with High Endothelial Venules in the Neonatal Rat Lymph Nodes: A Probable Relation to Immunoincompetence
Authors: Sainte-Marie G. , Guay G. , Peng F.S.
Published: July 2008

The endothelium of the high endothelial venules (HEVs) of lymph nodes is normally considered to inhibit an association with neutrophils. The present paper shows that for a few weeks after birth, however, neutrophils are commonly associated with the walls of HEVs, the extent depending on the site of the lymph node. Overall, neutrophils increase in numbers in rat nodes from birth until about day 11, and vanish progressively thereafter. Moreover, neutrophils are more abundant in the nodes of standard neonates than in the nodes of pathogen-free neonates raised in an aseptic milieu. It is concluded that the postnatal recruitment of neutrophils by nodal HEVs relates to the then prevailing state of immaturity of the immune system. An explanation is proposed as to why neonatal HEVs of nodes recruit neutrophils and not only lymphocytes, as is the case later in ontogeny.
Effect of 17-Beta-Estradiol on the Healing of Tibial Bone after Marrow Ablation
Authors: Stoumboudi M.Th. , Schwartz Z. , Sela J. , Goldstein D. , Yaffe P. , Boyan B.D. , Ornoy A.
Published: July 2008

The present study has been undertaken to demonstrate the effect of 17β-estradiol on the healing of tibial bones after marrow ablation. Ninety-six 4-month-old female rats were divided into three experimental groups: group 1 was subjected to ablation in both tibiae and to injection of vehicle; group 2 to ablation in both tibiae and estradiol administration, and group 3 to estradiol administration without ablation. Before the rats were killed, all on the same day, 8 animals of each group underwent treatment for 3, 6, 14 and 21 days, respectively: every second day, 0.1 ml arachis oil was injected intramuscularly into group 1 and 17β-estradiol into groups 2 and 3. An additional 8 untreated animals were used as controls. Tibial bones were studied chemically and morphologically. While the control and ablated animals gained weight, there was a significant decrease in the gain in body weight of estradiol-treated rats. Bone and ash weight were increased in all experimental groups. The ratios (%) of tibial ash weight and of tibial Ca and Mg contents to body weight significantly increased in all experimental groups, compared to the controls; whereas P increased only at 6 and 14 days. As shown by computerized histomorphometry, the height of the proximal tibial growth plate was increased following ablation, but not with estradiol treatment. The proportions by area of calcified cartilage and metaphyseal trabeclar bone were significantly lower and the percentage of bone marrow was higher in all groups treated for 3 and 6 days; the values were similar to those of the controls with 21 days of treatment. The results of this study indicate that intramuscular administration of estradiol to adult rats, after marrow ablation, did not significantly influence bone healing, as observed following ablation alone. It seems that the effects of estradiol on the bone of adult rats with slowly remodelling bones does not change with the increase in bone turnover, and that estradiol has little effect on endosteal bone undergoing enhanced remodelling.
Vagal Afferent Innervation of Rat Abdominal Paraganglia as Revealed by Anterograde Dil-Tracing and Confocal Microscopy
Authors: Berthoud H.-R. , Kressel M. , Neuhuber W.L.
Published: July 2008

Abdominal vagal afferent fibers were selectively labeled by injecting the fluorescent carbocyanine dye Dil into the left nodose ganglion of rats. Almost all paraganglia that were distributed along the five major abdominal vagal branches and their subbranches were found to be innervated by labeled vagal afferents. Laser scanning confocal microscopy with its single optical sectioning and three-dimensional reconstruction capabilities were used to analyze this innervation in more detail for paraganglia near the vagal hepatic branch and liver hilus. Furthermore, in double-labeling studies, it was demonstrated that a large percentage of the vagally innervated glomus cells were capable of catecholamine synthesis on the basis of their positive staining for tyrosine hydroxylase antibody. These findings support the concept of a chemoreceptive function for the abdominal paraganglia.
Bone-on-Bone Forces during Loaded and Unloaded Walking
Authors: Simonsen E.B. , Dyhre-Poulsen P. , Voigt M. , Aagaard P. , Sjøgaard G. , Bojsen-Møller F.
Published: July 2008

Joint moments and bone-on-bone forces in the ankle, knee and hip joint were studied in 7 healthy male subjects during unloaded and loaded walking. The subjects walked across a force platform while they were filmed at 200 Hz. Loaded walking was examined at 10 and 20 kg load carried symmetrically in the hands. Peak joint moments and peak bone-on-bone forces increased from unloaded to loaded walking for the ankle and hip joint (p < 0.05). The lowest bone-on-bone forces were found at the ankle joint (3,318 ± 390 N) during unloaded walking and the highest at the hip joint (6,399 ± 1,517 N) during 20 kg loading. Expressed relative to body weight (BW) these values corresponded to 4.2 ± 0.50 and 8.0 ± 1.78 BW). However, the individual values showed that 2 of the 7 subjects differed remarkably from the other 5, especially with respect to the hip joint loadings. During loaded walking (20 kg) these 2 subjects showed 14.4 and 15.1 BW peak compression force in the hip joint while the remaining subjects were all below 6.3 BW, which could be explained by the 2 subjects’ low ankle joint moments and higher knee and hip joint moments. Apparently, a total ‘leg moment’ formed by the three major joints is required to support the body and maintain the locomotion, although the relative contribution from each joint can differ among individuals. The peak joint moments were the most dominant contributor to the peak bone-on-bone forces. Therefore, it is concluded that interindividual differences in walking style can lead to pronounced differences in peak bone-on-bone forces. It remains unclear how these interindividual differences are related to joint degradation.
Transition from Lacunar to Villous Stage of Implantation in the Macaque, Including Establishment of the Trophoblastic Shell
Authors: Enders A.C.
Published: July 2008

Adhesion of trophoblast of the blastocyst to and penetration into the uterine epithelium, invasion into the maternal vessels and endometrial stroma, and establishment of the basic organization of the placenta all occur within the first week following the initiation of implantation in the human, macaques and several other primates. The cellular rearrangements and interactions of trophoblast with endometrial epithelial cells and stroma were studied during this periimplantation stage in macaques. At the early lacunar stage, 1–2 days after the initiation of implantation, both cytotrophoblast and syncytial trophoblast can be found at the maternal surface of lacunae. As the lacunar stage advances, both syncytial trophoblast and cytotrophoblast are found throughout the implantation site including in septae partitioning lacunae, but syncytial trophoblast lines most of the lacunae and forms the confluence with the maternal vessels. Indentations of fetal mesenchyme and accumulation of cytotrophoblast cells within the septae occur rapidly. Over a period of about 2 days, clusters of cytotrophoblast cells pass beyond the syncytial trophoblast at the maternal surface as the anchoring villi, establishing the trophoblastic shell. The bypassing of epithelial plaque cells by cytotrophoblast cells and elimination of stromal matrix between such clusters verifies that this is a progressive invasion rather than simply superficial growth. Concomitant with establishment of the trophoblastic shell there is extravasation of blood, necrosis of plaque cells, and massive invasion of vessels by cytotrophoblast resulting in a necrotic zone between the trophoblastic shell and endometrium. It is concluded that only in the brief period of time of establishment of the trophoblastic shell is the full invasive potential of cytotrophoblast realized and that only at this stage does cytotrophoblast demonstrate the type of invasive and migratory behavior which has been achieved with isolated human cytotrophoblast cells in vitro.