bluuebunny/crossref_metadata_2025_split huggingface dataset:
A study on the localization of the sternocleidomastoid and trapezius motoneurons in the rat by means of the HRP method
Authors: Kitamura Seiichiro , Sakai Akira 
Published: February 2005

AbstractThe sternocleidomastoid and trapezius muscles of the rat, which are innervated by the spinal accessory nerve (SAN) and cervical spinal nerve (CSN), consist of five smaller muscles: the sternomastoid, cleidomastoid, clavotrapezius, acromiotrapezius, and spinotrapezius. In this study, the location of cell somata of the motoneurons supplying each of these smaller muscles and the peripheral course of their axons have been studied by means of the horseradish peroxidase retrograde axonal transport technique (the HRP method) in combination with cutting of the SAN. The sternocleidomastoid and trapezius motoneurons formed three cell columns, column‐M, ‐L, and ‐5, in the ipsilateral ventral horn of the cervical spinal cord. Column‐M and ‐L, extend longitudinally in the medial nucleus of C1 and C2 and in the ventrolateral nucleus from the middle of C2 to the middle of C6, respectively. These columns consist of the motoneurons whose axons pass through the SAN and they merge in the caudal C2 to constitute the spinal accessory nucleus. Column‐5, which consists of the motoneurons passing through the CSN, extends longitudinally from C3 to C5 close to column‐L in the ventrolateral nucleus. Motoneurons supplying the sternomastoid, cleidomastoid, clavotrapezius, acromiotrapezius, and spinotrapezius muscles showed a rostrocaudal somatotopic distribution in the spinal accessory nucleus and in column‐5 in this order, though the sternomastoid motoneurons were not found in column‐5.
Further evaluation of the superficial and deep tendons of the human temporalis muscle
Authors: Harn Stanton D. , Shackelford Lee S. 
Published: February 2005

AbstractThe superficial and deep tendons of the human temporalis muscle and their fasciae were examined for specific attachments. It was found that as they pass inferiorly along the ramus of the mandible, a structure consisting of tendon and fascia (herein referred to as the fascial‐tendinous complex or FTC) is projected anteromedially and inferiorly. The FTC is a unifying structure in the oralbuccal area, serving as a common point of attachment for three muscles of mastication (temporalis, masseter, and medial pterygoid) as well as the buccinator, superior pharyngeal constrictor (SPC), and the mylohyoid muscles, and their corresponding fasciae. The FTC creates a defined fascial space containing loose connective tissue, the buccal nerve, and corresponding blood vessels between the posterior buccal region and the anterior ramus and posterior body of the mandible. The FTC has two components: (1) a medial part which merges into the posterior buccal region in the area of the pterygomandibular depression and (2) a lateral part which continues inferiorly to the posterior area of the body of the mandible.A distinct slip of the medial pterygoid muscle was found to attach to the FTC which caused the lingual nerve to be sandwiched between this slip and the main bulk of the medial pterygoid as it inserts into the mandible.The pterygomandibular raphe, as previously described, was not found. Because of the FTC, the buccinator and SPC do not have simple hamulus‐raphe‐mylohyoid line attachments. The exact relationship of the buccinator and SPC is dependent upon the extent of the FTC. The larger the FTC, the greater are the muscle attachments and vice versa. In large FTCs a separate muscle (Hamular‐FTC muscle) was found attaching from the hamulus to the FTC.The pterygomandibular fold was found not to coincide with the “raphe.” The concavity of the pterygomandibular depression upon depression of the mandible was found to be the result of the FTC.
Whole population cell kinetics of mouse duodenal, jejunal, iieal, and colonic epithelia as determined by radioautography and flow cytometry
Authors: Cheng Hazel , Bjerknes Matthew 
Published: February 2005

AbstractWe report methods for the determination of whole population cell kinetics in the mouse intestinal epithelium by means of radioautography and flow cytometry. Epithelium was isolated from the four regions of the mouse intestine by the perfusion method described in Bjerknes and Cheng (1981a). Two experimental series were performed. In the first series, the tissue from one set of animals was fixed in 3.5% paraformaldehyde, dissociated by serial filtration, and then processed for flow cytometry. In the second series, fixed epithelium from a second set of animals was dissociated by gentle pipetting and then used to prepare dried cell suspensions on slides which were radioautographed. The whole population kinetic parameters determined by the two techniques, flow cytometry and radioautography, were not significantly different, indicating the reliability of both techniques for whole population kinetics determinations. In all regions of the intestinal tract, 12–14% of epithelial cells were in the S‐phase. From this value, the whole epithelial turnover time was calculated to be about 60 hours in all regions of the intestine. The whole epithelial growth fraction was calculated to be 0.23 for the small intestinal epithelium and 0.31 for the colonic epithelium. Detailed analysis of the flow cytometric data showed that there were significantly more cells in early S‐phase than in mid and late S‐phase. From the isolated epithelial sheets a mean number of crypts per villus was determined for the duodenum, jejunum, and ileum. Single villi and crypts were microdissected for the preparation of squashes. From the squashes a mean number of cells per villus as well as per crypt was determined. From the results, the ratio of the number of epithelial cells in the villus population to the number of cells in the crypt population was determined to be 1.41, 1.31, 1.36 in duodenum, jejunum, and ileum, respectively. The proportion of the three main epithelial cell types, columnar, mucous, and Paneth, was determined with the dried cell suspension preparations. There was a decreasing gradient in the proportion of columnar cells from the proximal to the distal intestine while an increasing gradient was observed in the proportion of mucous cells. We found that mucous cell divisions account for only one half of mucous cell production in the small intestine. In the colonic epithelium, mucous cell divisions account for two‐thirds of mucous cell production. This was in agreement with previous findings.
A radiographic study of the longitudinal growth of primary ossification centers in limb long bones of the human fetus
Authors: Bagnall K. M. , Harris P. F. , Jones P. R. M. 
Published: February 2005

AbstractThis paper describes an extensive study of the growth of ossification centers in limb long bones of the human fetus from 8 to 26 weeks of conceptual age. Longitudinal measurements were made of the femur, tibia, fibula, humerus, radius, and ulna. Comparisons were made between bones on the left and right sides of the body and between the sexes. Standards are presented for the growth of these centers. They compare well with previous studies, any differences being accounted for by different methods of aging and measurement.A complicated picture of growth of the two sides of the fetal body is presented. Growth of the humerus, tibia, and fibula appears to be dominant on the left side of the body while growth in the femur is dominant on the right. At present, no explanation is available, but it is possible that factors such as manual dominance may be related. Evidence also is presented which suggests that the female fetus is in advance of the male in terms of ossification but only after 21 weeks gestation.
Intercellular contacts between migrating blood cells and cells of the sinusoidal wall of bone marrow. An ultrastructural study using tannic acid
Authors: Campbell Ferrell R. 
Published: February 2005

AbstractThe migration of blood cells across the sinusoidal wall of murine bone marrow was studied following fixation with tannic acid‐glutaraldehyde. Electron microscopic examination showed regions of close membrane apposition (referred to in this study as “intercellular contacts”) between migrating blood cells and cells of the sinusoidal wall (adventitial and endothelial cells). Ultrastructurally the intercellular contacts are pentalaminar structures resembling gap junctions of other organs after tannic‐acid fixation. The possibility that these contacts are regions of intercellular communication and/or sites of membrane attachment utilized for locomotion of the migrating blood cells is discussed.
Dorsal cerebral arterial collaterals of the rat
Authors: Coyle Peter , Jokelainen Pentti T. 
Published: February 2005

AbstractThis study demonstrated that distal branches of the anterior cerebral artery (ACA) are joined by interarterial anastomoses to rami of the middle cerebral artery (MCA) in the normal Wistar rat. Arteries of 36‐ and 56‐day‐old animals were dilated with papaverine and injected with Vultex. Vultex arrived at corresponding ACA and MCA collaterals simultaneously as determined by microscopy through a skull window and photography. There were about 29 ACAMCA junctions per hemisphere. Junction density was nearly constant along the frontal‐occipital axis. The anastomoses were most numerous between 2 and 3 mm lateral to the midline and were less than 120 μm in internal diameter. No significant difference was found between total numbers of junctions for right versus left hemispheres or between age groups. The most evident collateral pattern was characterized by two ACA end rami joining two MCA end branches to form a closed, diamond‐shaped collateral unit. Considerations were given to alternate routes of blood flow into the MCA tissue field. We conclude abundant dorsal anastomoses exist in 36‐ and 56‐day‐old rats and are the prime potential source for ACA collateral supply to the MCA tissue field.
Intramuscular variation of fiber types in the brachial biceps and the lateral vastus muscles of elderly men: How representative is a small biopsy sample?
Authors: Nygaard E. , Sanchez J. 
Published: February 2005

AbstractThe aim of the study was to investigate the reliability of the distribution of muscle fiber types determined in small fragments of human skeletal muscle. Fiber‐type distribution was analyzed in small areas, equivalent to a needle biopsy in size, and in large areas, at nine sites of the brachial biceps (BB) and the lateral vastus (LV) muscles obtained at autopsy from five elderly subjects. It was concluded that in the BB the site of a biopsy should be well defined, since, the incidence of fiber types varied systematically. In the LV the biopsy should be large to permit a reliable estimate of the incidence of fiber types; with the needle technique, repeated sampling may be necessary. Small samples are not suited for the analysis of fiber type grouping.
A new morphological procedure for viewing microvessels: A scanning electron microscopic study of the vasculature of small intestine
Authors: Miller Bryan G. , Woods Richard I. , Glenn Bohlen H. , Evan Andrew P. 
Published: February 2005

AbstractThe present study details a new method for the exposure and viewing of individual microvessels located within the small intestine of rats. This procedure will selectively and consistently remove the outer muscle layers and underlying submucosa of the intestinal wall and thereby expose a variety of arterioles in their normal location within the tissue, with their normal relationship to each other undisturbed. The small intestine of the rat was initially fixed by vascular perfusion with 2.5% glutaraldehyde in 0.1 M cacodylate/HCL buffer, reinfused with heparinized whole blood, removed from the animal, and secured to a dissecting petri dish for further fixation. Subsequently, the external muscularis was dissected from the sample which exposed the submucosa. In order to remove the connective tissue elements from this layer and uncover the submucosal vasculature, the samples were first transferred to a solution of 30% potassium hydroxide for 2–5 minutes and then to a final digesting solution containing collagenase. Thereafter, the samples were routinely processed for light microscopy and for scanning (SEM) or transmission (TEM) electron microscopy. Examination of the samples revealed excellent preservation of the three‐dimensional organization of the arteriolar wall with minimal membrane damage. This new technique now makes it possible to visualize the shape and position of individual smooth muscle cells along arterioles of differing size and branching order.
A histochemical analysis of identified compartments of cat lateral gastrocnemius muscle
Authors: English Arthur Wm. , Letbetter William D. 
Published: February 2005

AbstractThe lateral gastrocnemius muscle of cats can be divided into four discrete subvolumes or compartments which are supplied by the primary branches of its muscle nerve. The histochemical profile of each compartment was determined from the reaction for myosin ATPase after acid preincubation. Fibers were classified as fast‐twitch glycolytic (FG), fast‐twitch oxidative‐glycolytic (FOG), or slow‐twitch oxidative (SO). Each compartment in each cat examined was found to contain a relatively uniform distribution of different types of fibers. The most proximal LG compartment contains mainly type FG fibers, with relatively few type SO fibers; the most distal compartment, while still predominated by type FG fibers, contains a significantly larger proportion of type SO fibers. The histochemical profile of the intermediate compartments indicates that they contain fibers which lie intermediate in composition between these two. These results are consistent with the notion that LG compartments consist of aggregations of motor units, arranged such that muscle fibers comprising a single motor unit are contained within a single compartment.
Myocardial fiber architecture of the human heart ventricles
Authors: Fernandez‐Teran M. A. , Hurle J. M. 
Published: February 2005

AbstractThe ventricular fiber architecture has been studied anatomically and histologically in 25 human hearts. Special attention has been paid to the form of insertion of the myocardial fibers and to the existence or nonexistence of an independent system of fibers for each ventricle. Three different myocardial layers—superficial (subepicardial), middle, and deep (subendocardial)—have been distinguished according to the fiber direction through the ventricular mass. All the fibers are common for both ventricles with the exception of a thick middle layer peculiar to the left ventricle. The tendinous cords, the central fibrous body, and the arterial fibrous rings are the major zones of insertion of myocardial fibers. On the basis of our results we have attempted to correlate the ventricular architecture with the valvular dynamics.
Distribution of fibronectin in normal and regenerating skeletal muscle
Authors: Gulati Adarsh K. , Reddi A. H. , Zalewski Andrew A. 
Published: February 2005

AbstractThe distribution of fibronectin in normal and regenerating skeletal muscle (the latter caused by autotransplantation) was investigated by means of indirect immunofluorescent technique. Normal myofibers exhibited a thin, continuous pericellular (endomysium) fibronectin distribution; however, their sarcoplasm was devoid of fibronectin. After autotransplantation, the skeletal muscle fibers underwent a process of degeneration that was followed by regeneration from the premyogenic satellite cells. These cells multiplied, fused to form myotubes, and matured into new myofibers. A decrease and an eventual loss of endomysial fibronectin was seen in the degenerating myofibers. At the same time, fibronectin appeared in the sarcoplasm. No significant fibronectin was expressed in the myogenic zone until the formation of myotubes which possessed a complete, circular fibronectin ring. The sarcoplasm of the myotubes lacked fibronectin. Since fibronectin is a component of basement membrane of several tissues, its disappearance and reappearance can be used to follow the fate of basement membrane. We conclude that fibronectin may not be essential for early myogenesis and that regenerated myotubes form an entirely new or at least certain new molecular components of their basement membrane. The present muscle autotransplantation model can be used to further study the role of fibronectin during myogenesis and cell transformation in vivo.
Fine structural criteria for pituitary thyrotrophs in immature and mature rats
Authors: Yoshimura Fujio , Nogami Haruo , Yashiro Takashi 
Published: February 2005

AbstractFine structural criteria for identifying thyroid‐stimulating hormone (TSH) cells in immature and mature rats have been studied by a modified superimposition technique. On days 10 and 20, some small oval immature TSH cells are scattered individually throughout the glandular tissue with a peripheral immunoreactive rim resulting from the sparse distribution of minute secretory granules less than 50 nm in diameter. The immunostained stellate TSH cells are clustered and have secretory granules 50–100 nm in diameter at the cell margins. On day 60, a few small immature TSH cells still remain. Although a few polygonal TSH cells that may not fully mature accumulate secretory granules 100–150 nm in diameter at the cell margins, the majority of TSH cells take the form of large stellate cells filled with secretory granules with the corresponding diameter, and surround an acidophil. These stellate TSH cells are characterized by dense arrangement of parallel arrays of rough endoplasmic reticulum (rER) or rER cisternae. The clustered or isolated elongate TSH cells are also observed to be vesiculated and to have numerous secretory granules 150–250 nm in diameter. In addition, large oval vesiculated TSH cells storing numerous secretory granules 150–250 nm in diameter appear sporadically in the gland, ultrastructurally resembling the gonadotrophs. It is concluded that the rat TSH cell is not a single type with a particular ultrastructure, but modifies its morphology according to its maturation or functional phase.
The maturation of the end bulb of Held in the rat anteroventral cochlear nucleus
Authors: Neises G. R. , Mattox D. E. , Gulley R. L. 
Published: February 2005

AbstractThe maturation of the end bulb of Held was studied in serial thin sections through the rostral pole of the rat anteroventral cochlear nucleus (AVCN) at 2‐day intervals from birth through 16 days of age. In the neuropil of newborn rats primary auditory terminals occasionally synapse with large dendritic processes of spherical cells. Between 6 and 10 days of age, the spherical cell has numerous, long, fingerlike appendages at the base and proximal part of its primary dendrite which extend into the neuropil and envelope a single primary terminal. Small processes from the terminal extend along the appendages toward the cell body. At 10 days, these processes reach the dendritic pole of the soma and fill the interstices between the appendages. Synaptic contacts are present between the end bulb processes and the cell body. At 12 days, the end bulb covers most of the dendritic pole of the spherical cell. The remaining somatic appendages are small and are clustered beneath the end bulb. Synapses between the end bulb and soma are frequent. At 16 days, the end bulb resembles that seen in the mature rat. Nonprimary terminals appear on the soma at 10 days. These terminals are randomly distributed, with fine processes which extend from the end bulb over the remaining regions of the cell body.
Genetic comparisons of eumelanosome ultrastructure
Authors: Zimmerman Joel , Winfrey Frank , Brumbaugh John 
Published: February 2005

AbstractWe recently reported the existence of several new ultrastructural components of the eumelanosome matrix from developing chick pigment epithelium. The material used in the original study was obtained from a random sample of heterogeneous chicken. We have now extended this analysis to four genetically well‐characterized chicken types: jungle fowl, blue, dominant white, and recessive wheaten. In these four genotypes there are specific ultrastructural alterations in the eumelanosome matrix. These alterations are different for each of the genotypes studied and are probably reflective of differences in the functional nature of the genes involved. The data thus provide evidence as to which genes are structural and which regulatory in action. Furthermore, since the material analyzed was all derived from pigmented pigment epithelium, it is clear that these melanosomes are affected by genes previously thought to leave them untouched. Finally, data are presented that these new ultrastructural elements are also found in a different class of animals, the C57BL/10 mouse.
Autoradiographic evidence of a loss of iodination within hormone‐dependent GR mouse mammary tumors as they progress to independence
Authors: Strum Judy M. 
Published: February 2005

AbstractThe purpose of this study was to determine by use of light‐ and electron‐microscope autoradiography whether or not iodination occurred in mammary tumors of female GR mice. Of the sixty tumors studied it was found that pregnancy‐dependent and hormone‐induced tumors possessed iodinating ability. Although mammary glands from nonpregnant GR mice lacked the ability to iodinate, by the 16th day of pregnancy in response to hormonal stimulation the glands readily iodinated casein, and some epithelial cells contained ultrastructural cytochemical evidence of mammary peroxidase. Preneoplastic mammary gland lesions known as hyperplastic alveolar nodules were also able to iodinate, as were plaques, the disc‐shaped lesions which give rise to the hormone‐responsive mammary tumors in this strain. Plaques also contained epithelial cells with mammary peroxidase activity. When hormone‐induced mammary tumors were transplanted into syngeneic mice they retained the ability to iodinate for several generations. However, as the tumors progressed to hormone independence, the ability to iodinate was gradually lost. Hormone‐independent mammary tumors from GR mice lacked both iodinating ability and cytochemical evidence of mammary peroxidase. These findings suggest that iodination depends upon hormone‐responsive cells within the mammary tumors and that as these cells become hormone unresponsive, the ability to iodinate is lost.
Evidence for a blood‐ganglion barrier in the superior cervical ganglion of the rat
Authors: Depace Dennis M. 
Published: February 2005

AbstractThe permeability of the blood vessels in the superior cervical ganglion of the rat was tested by intravenous injection of horseradish peroxidase (HRP).By light microscopy, peroxidase activity was found in three locations: in the capsule of the ganglion, in the lumina of the blood vessels, and within macrophages. Electron microscopy revealed that virtually all ganglionic blood vessels contained HRP 5 minutes following its administration. The intensity of peroxidase activity declined over the period of 15 minutes. The enzyme was localized on the luminal surface of the endothelial cells, attaching to the glycocalyx. Endothelial microvilli, projecting into the vessel lumen, were also covered with peroxidase. Micropinocytotic vesicles on the luminal surface of the endothelium contained reaction product. Some of these vesicles were free within the cytoplasm of the endothelium but none was observed on the abluminal surface. Peroxidase activity was not detected in the extracellular space even after 15 minutes.The majority of blood vessels in the superior cervical ganglion possess a continuous endothelium with tight junctions; features associated with the blood‐brain barrier of the central nervous system and peripheral nerves. It is proposed that these vessels perform a barrier function between the capillary circulation and the superior cervical ganglion.