bluuebunny/crossref_metadata_2025 huggingface dataset:
Organization of Forelimb Motoneuron Pools in Two Bat Species (Eptesicus fuscus and Myotis lucifugus)
Authors: Ryan J.M. , Cushman J. , Baier C.
Published: July 2008

The present investigation provides further evidence of the conservation of motor nuclei in amniotes. The position of six forelimb and shoulder motor pools were mapped in two species of bat, Eptesicus fuscus and Myotis lucifugus. The intraspinal locations of motor pools were revealed by labeling with the retrograde neuronal tracer WGA-HRP injected into the bellies of six muscles: m. pectoralis, m. spinodeltoideus, mm. triceps brachii (long and lateral heads), m. infraspinatus, m. supraspinatus, and m. biceps brachii. The positions of the labeled motor pools were reconstructed from serial transverse and horizontal sections of the spinal cord. WGA-HRP-labeled cells were located midway between cervical spinal nerves four and five to midway between cervical spinal nerve eight and the first thoracic spinal nerve. Individual motor pools formed fusiform clusters of cells with little intermingling of neurons between adjacent motor pools. The pectoralis motor pool contained significantly more motoneurons than all other motor pools for M. lucifugus. The pectoralis pool in E. fuscus contained more motoneurons than the biceps, supraspinatus, and infraspinatus, but not the spinodeltoid or the triceps brachii. The biceps, spinodeltoid, infraspinatus and supraspinatus pools were located rostrally; the pectoralis and triceps pools caudally. The pectoralis pool was the most medial and the spinodeltoid pool was the most lateral. These data suggest that the locations of shoulder and forelimb motor pools are ontogenetically and phylogenetically conserved across tetrapods and independent of the function of the muscles in adults.
Organization of the Lamina propria mucosae of Rat Intestinal Mucosa, with Special Reference to the Subepithelial Connective Tissue
Authors: Toyoda H. , Ina K. , Kitamura H. , Tsuda T. , Shimada T.
Published: July 2008

Light microscopy, scanning electron microscopy and transmission electron microscopy have been used to delineate the structure and function of the lamina propria mucosae in the rat jejunum. In silver-impregnated sections, the adepithelial surface of the lamina propria mucosae was framed by a sheet of reticular fibers (reticular sheet). Short-term (3-hour) immersion of jejunal tissues in 2 N NaOH solution enabled us to simultaneously view networks of reticular fibrils and fibroblasts residing in the subepithelial connective tissue under a scanning electron microscope. The reticular fibrils, which measured about 40 nm in diameter and were interwoven in dense networks, formed a sheet 2–3 µm thick. In the villi, this sheet contained numerous foramina ranging from 3 to 7 µm in diameter, through which lymphocytes, macrophages, basal extensions of epithelial cells and fat particles traversed. The reticular sheet in the domes of isolated lymphoid nodules was markedly porous, and many lymphocytes migrated into or out of the epithelium through the foramina. The foramina of the reticular sheet may participate in the communication between the intestinal epithelium and the lamina propria mucosae. It was noted that the foramina of the reticular sheet in the villi were surrounded by end feet of the cytoplasmic processes of fibroblasts. In addition, these fibroblasts were combined with lymphocytes or dendritic cells in the lamina propria mucosae.
Blebs in the Mouse Cerebellar Granular Layer as a Sign of Structural Inhomogeneity 1. Anterior Lobe Vermis
Authors: Hawkes R. , Gallagher E. , Ozol K.
Published: July 2008

The cerebellum is a modular structure. However, the size of the fundamental compartments is uncertain, with anatomical methods showing a parasagittal band arrangement but electrophysiological mapping suggesting a finer subdivision into microzones and patches. A new anatomical way to demonstrate compartmentation is described. The cerebellum is fixed by perfusion with 70% ethanol, paraffin-embedded and sectioned. When the sections are rehydrated the granular layer pleats into an elaborate array of blebs. These blebs are seen in both transverse and sagittal sections, found in all lobules of both the vermis and the hemispheres, symmetrical about the midline, reproducible between neighboring sections and between individuals, and bear a constant relationship to the Purkinje cell bands as revealed by zebrin II immunocytochemistry. The data suggest that the granular layer of the adult mouse cerebellum is divided into several thousand modules. These modules may reflect the mossy fiber topography, and may be the anatomical equivalents of the tactile receptive field patches. Such a profound compartmentation has important implication for theories of cerebellar structure and development.
Alkaline Phosphatase Distribution in Rat Endometrial Epithelium during Early Pregnancy: A Scanning Electron-Microscopic Study
Authors: Winkelmann A. , Spornitz U.M.
Published: July 2008

The participation of apical membranes of uterine epithelial cells in the process of blastocyst adhesion makes them an interesting object in the study of changes occurring during early pregnancy. In the study of these changes alkaline phosphatase (A1P), a typical brush border enzyme, was chosen for demonstration with the scanning electron microscope (SEM) by means of a backscatter detector. Thus the temporal and spatial pattern of enzyme activity on the uterine luminal surface was made visible with lead salt procedures. A1P activity was shown to be located on apical membranes and microvilli of endometrial epithelial cells with high activity on day 2 of pregnancy decreasing to virtually no activity on day 5. This decrease in overall A1P activity was shown to be asymmetrical with respect to the uterine cavity. It begins on the antimesometrial half of the uterine lining on day 2. A distribution pattern demarcating a presumptive implantation site along the uterine horn was not found. However, on day 5 of pregnancy, a characteristic pattern of surface folds was found, dividing the uterine horn into ‘implantation segments’. In addition, SEM investigation revealed a marked variation of A1P activity from one individual cell to the next on day 2 of pregnancy resulting in a mosaic-like pattern. This pattern is lost with the decrease of A1P activity on day 5. Thus heterogeneity of uterine epithelial cells in A1P activity is apparently a feature of nonreceptive epithelium in contrast to the homogeneous epithelium on day 5. It is proposed that epithelial cell homogeneity could be a marker for uterine receptivity.
Asymmetry of Normal Mandibular Condylar Shape
Authors: Ferrario V.F. , Sforza C. , Miani Jr. A. , Sigurtà D.
Published: July 2008

Morphological studies of the facial skeleton in human beings are usually made from radiographs (frontal and lateral projections and orthopantomographs). The conventional linear and angular measurements provide quantitative information only about size, and fail to define the shape and form of the skeletal features and their variations. Mathematical methods such as the Fourier series allow a correct quantitative analysis of the shape and its variations. The outlines of the mandibular condyles in the orthopantomographs of 20 men and 20 women (mean age 29 years) were traced and digitized. All subjects had a good dentition, no temporomandibular joint problems, and were referred to a dental surgery for periodontal problems. A Fourier analysis of the outlines was performed. Fourier coefficients and reconstructed outlines were compared to analyze the condylar symmetry of shape on an intra- and intersubject basis. A significant condylar asymmetry for shape as distinct from size was found on an intrasubject basis, i.e. the left and right condyles of a single individual had a different shape with a large interindividual variability. Conversely, the mean condyle shape of the male and female groups was symmetric.
Morphological Analysis of the Human Tibialis Anterior and Medial Gastrocnemius Muscles
Authors: Wolf S.L. , Kim J.H.
Published: July 2008

The morphology and nerve innervation patterns of eight tibialis anterior (TA) and medial gastrocnemius (MG) muscles from human cadavers were examined. TA has three distinct partitions, two of which lie posteriorly. The anterior aspect of the muscle has one partition (head A) whose fibers are oriented longitudinally. The posterior partitions possess fibers that course longitudinally (B head) and obliquely (C head). The posterior longitudinal fibers and the anterior longitudinal fibers are divided by an aponeurosis that is continuous with the tendon of insertion. The proximal muscle fibers insert into this aponeurosis and the distal fibers insert into the tendon. The MG is a unipennate muscle. Both TA and MG muscles show variations in innervation patterns among specimens. In light of these findings, partitioning of TA may be based on its architecture.
The Influence of Forearm, Hand and Thumb Positions on Extensor carpi ulnaris and Abductor pollicis longus Activity
Authors: van Oudenaarde E. , Brandsma J.W. , Oostendorp R.A.B.
Published: July 2008

The objective of this study was to investigate the influence of forearm, hand and thumb positions on electromyography (EMG) activity of the abductor pollicis longus (APL) and the extensor carpi ulnaris (ECU) muscles. A second objective was to study the role of these muscles in stabilizing the wrist during movements of the thumb. This knowledge is important in clinical assessment and reconstructive surgery. At a constant force of 5 N for the thumb and 20 N for the hand, EMG activity was recorded with intramuscular wire electrodes in isometric and dynamic contractions in different positions and movements in the thumb and the hand. EMG activity of the right hand of 7 subjects was scaled relative to the mean EMG value at maximum voluntary isometric contraction to compare relative muscle activity in the tests. The results show that the position of the forearm does influence activity of the APL, but not of the ECU. The deep part of the APL shows differences in EMG activity between the positions of the forearm in dorsal flexion of the hand and the superficial part of the APL in palmar flexion of the hand. The ECU and the deep part of the APL are very active during movements and isometric contractions of the thumb. It is suggested that these muscles are necessary to stabilize the wrist during movements of the thumb to prevent undesired movements of the hand and the forearm.
Hyaluronan in Human Deciduous Tooth Germs in the Bell Stage
Authors: Matthiessen M.E. , Garbarsch C. , Engelbrecht Olsen B. , Hellström S. , Engström-Laurent A.
Published: July 2008

The primary aim of the present study was a localization of hyaluronan (HA) in human deciduous tooth germs in the bell stage. HA was compared to the content of chondroitin sulfates (CSs). HA was detected with a biotin-labeled HA-binding protein (HABP) and CS with a monoclonal antibody. As controls, enzyme digestions were carried out. Furthermore, the glycosaminoglycans were investigated histochemically with enzyme digestions followed by alcian blue staining. The investigation showed a considerable content of HA in the stellate reticulum, although CS was also found, primarily when treatment with protease was omitted. The dental papilla contained both HA and CS, while the predentin and the dentin contained only CS. The enamel did not contain any CS, but some staining with HABP was observed along the borderline between the ameloblasts and the enamel. The significance of HA in the stellate reticulum is discussed. The importance of carrying out investigations with and without protease digestions is stressed.
Developmental Study of the Round Window Region
Authors: Bonaldi L.V. , De Angelis M.A. , Smith R.L.
Published: July 2008

A silicone impression method to study the anatomy of the round window region was used in 102 temporal bones belonging to individuals aged from 4 months of fetal life to 3-year-old children as well as adults. A total of 2,142 measurements of the round window, oval window and round window fossula was made in the molds. The data demonstrate that the round window shows a diameter from 1.21 mm (average for the short axis) to 1.74 mm (average for the long axis) and the circular shape was present in 55% of the adult temporal bones and in 18.18% of the fetal and infantile ones. The adult dimensions of the measured structures are reached during fetal development.
Effects of Continuous or Cyclic Administration of Pamidronate on the Skeleton in Intact and Oophorectomized Young Rats
Authors: Patlas N. , Yaffe P. , Kimyagarov A. , Golomb G. , Ornoy A.
Published: July 2008

Bisphosphonates are potent inhibitors of bone resoφtion, and are therefore used for the treatment of various bone diseases including osteoporosis. We examined whether cyclic therapy with bisphosphonates in oophorectomized osteoporotic rats had any advantage over continuous treatment. We therefore treated intact and oophorectomized young female rats for 8 weeks with 1 and 5 mg/kg/day of pamidronate. The 8-week treatment was given continuously for 6 days/week or intermittently, i.e. 6 days of pamidronate (APD) and 3 weeks off, for 2 cycles. We found an increase in tibial wet and ash weight and in the mineral content in oophorectomized rats treated continuously or intermittently with APD in comparison to nontreated oophorectomized animals. Histomorphometric analysis showed an increase in the volume of metaphyseal cartilage and bone. No changes were found in the volume of epiphyseal or diaphyseal bone. Pamidronate had very little effect on the bone of intact rats. Pamidronate seems to be more effective in inhibiting bone resorption in bone that undergoes rapid turnover (i.e. in oophorectomized animals) when compared to bone with low turnover (intact rats). Although the results of cyclic treatment were similar to those of continuous treatment, we have to remember that cyclic therapy may be more advantageous since animals receiving cyclic therapy received only 25% of the dose of rats continuously treated.
Function and Structure in Early Modern Muscular Mechanics
Authors: Kardel T.
Published: July 2008

The dispute on the movement of skeletal muscles in 1667 between Giovanni Alfonso Borelli, who maintained the ancient movement caused by inflation theory, and Niels Stensen (Nicolaus Steno), who proposed the first recorded theory of fibre contraction, had far reaching implications for understanding the relation between muscle morphology and function. A dialogue is reconstructed from citations from the two authors’ main works. They had a similar dispute on the movement of the heart along the lines of the debate in the 1630s between William Harvey favouring contraction and Rene Descartes favouring swelling. Evidence is provided for the delayed general acceptance of fibre contraction in both heart and skeletal muscles. It is shown that the inflation interpretation of muscular mechanics elaborated by Borelli, Johann Bernoulli, his son Daniel, and by others, was maintained from ancient authors and Descartes in part due to a conceptual block resulting from the mechanical philosophy that denied any force of attraction in nature. The alternative theory, that of fibre contraction, was thought of as self-motion, which violated an accepted mechanical principle and therefore was rejected. In the mid-18th century, Albrecht von Haller recorded no microscopic structures in support of inflation. He adopted the view that contraction in fibres of muscles is generated through an ‘irritability’. Research on this entity has taken place ever since with a clear preponderance of studies on single fibre properties and subcellular structures. Haller did not, however, refer to the original contribution of Stensen on fibre contraction. Haller even rejected Stensen’s functional architecture of skeletal muscle. This structure, now called the unipennate, or semipennate, actuator, was overlooked and had to await confirmation by anatomical rediscovery and pragmatic demonstration through successful applications in computer models of muscular contraction in the 1980s.
Estimation of Active Force-Length Characteristics of Human Vastus lateralis Muscle
Authors: Ichinose Y. , Kawakami Y. , Ito M. , Fukunaga T.
Published: July 2008

The length and angles of fascicles were determined for the vastus lateralis muscle (VL) using ultrasonography in 6 subjects performing ramp isometric knee extension. The subject increased torque from zero (relax) to maximum (MVC) with the knee positioned every 15°, from 10° to 100° flexion (0° = full extension). As the knee was positioned closer to extension, fascicle length was shorter [116+4.7 (mean ± SEM) mm at 100° vs. 88+4.1 mm at 10° (relax)]. The fascicle length of the VL decreased with increasing torque at each knee position [116+4.7 (relax) to 92 ± 4.3 mm (MVC) at 100°]. On the other hand, fascicle angles increased with an increase in torque. These changes reflected the compliance of the muscle-tendon complex which increased as the knee reached a straight position. The estimated muscle force of the VL was maximal (2,052 ± 125 N) for a fascicle length of 78 ± 2.7 mm (i.e. optimum length) with the knee positioned at 70° of flexion. The relationship between muscle force and fascicle length indicated that the VL uses the ascending (knee < 70°), plateau (70 °), and descending regions (> 70°) of the force-length curve.
Effects of Muscle Length on the Response to Unloading
Authors: Ohira Y. , Yasui W. , Roy R.R. , Edgerton V.R.
Published: July 2008

Muscle mass, distribution of fiber types, fiber cross-sectional area (CSA) and selected enzyme activities were determined in rats hindlimb-suspended free of immobilization (Susp-Free), suspended with the ankle dorsiflexed (Susp-DF, soleus stretched) or plantarflexed (Susp-PF, soleus shortened) for 10 days and compared to cage-control (Con) rats. Reduction of muscle weight associated with suspension was prevented in Susp-DF rats. The mean CSAs of slow fibers were Con=Susp-DF > Susp-PF > Susp-Free and of fast and intermediate fibers tended to be Susp-DF > Con > Susp-PF=Susp-Free. Mean activities of succinate dehydrogenase (SDH), α-glycerophosphate dehydrogenase (GPD) and myofibrillar adenosine triphosphatase (mATPase) in slow and fast fibers were similar in Con and Susp-Free rats. Mean SDH activity in slow fibers was higher in Susp-DF and Susp-PF than in Con and Susp-Free. No significant differences in SDH activities of fast fibers were observed among groups. GPD activity was higher in slow fibers of Susp-DF and Susp-PF compared to Con. The mATPase activity was higher in slow fibers of Susp-DF compared to Con and Susp-Free rats and lower in fast fibers of Susp-DF compared to Con rats. Thus, when compared to control, the patterns of adaptation were more similar in the Susp-DF and Susp-PF than in the Susp-Free. Although these results are consistent with previous studies demonstrating that the load placed on a muscle can affect protein metabolism, the direction and magnitude of the adaptive responses observed in the present study were closely associated with the chronically imposed changes in muscle length, i.e. fixed at either a shortened or a lengthened position.
Functional Morphology of Serially Linked Skeletal Muscle Fibers
Authors: Hijikata T. , Ishikawa H.
Published: July 2008

In the skeletal muscle fiber organization of many vertebrate muscles, serial arrangements or linkages of muscle fibers along the muscle or fascicle are commonly found. These serially linked muscle fibers employ distinct junctional morphologies from muscle to muscle. Notable are the end-to-end linkages of muscle fibers through tendinous intersections (TIs), where many fibers end onto a continuous connective tissue plate with folded terminations similar to myotendinous junctions. Besides this end-to-end linkage, overlapping linkages or arrangements occur among nonspanning fibers terminating intrafascicularly. These nonspanning fibers bear tapering terminations with direct cell-cell (myomuscular) junctions or without any specialized junctions. Despite their overlapping linkages or tapering profiles, nonspanning fibers maintain a uniform sarcomere length along the linked fibers, suggesting that the overlapping-linked nonspanning fibers are equivalent to the end-to-end linked fibers in their mechanical capacity. However, the junctional compliance could differ in their extracellular elastic components and their organization at junctional sites, e.g., direct mechanical (myomuscular) junctions vs. indirect linkages through connective tissue. Increasing evidence suggests that the elastic components, including muscle fibers as well as connective tissues, are more critical than previously thought for the mode and/or the efficiency of tension transmission among serially arranged fibers and thus for the mechanical properties of the muscle.
Skeletal Muscle Architecture and Fiber-Type Distribution with the Multiple Bellies of the Mouse Extensor digitorum longus Muscle
Authors: Chleboun G.S. , Patel T.J. , Lieber R.L.
Published: July 2008

The purpose of this study was to describe the extent to which architectural and fiber-type characteristics of the four bellies of the mouse extensor digitorum longus (EDL) suggest specialization of the digits, and to mathematically model the functional effects of the structural properties. Six mice were perfused in situ with glutaraldehyde while the lower limb was positioned approximately in the neutral position. After perfusion, lower limbs were removed and placed in glutaraldehyde until the EDL was dissected from the limb and separated into individual muscle bellies corresponding to each digit for architectural determination. The results showed that the muscle belly of digit 5 tended to be different from the muscle bellies of digits 2–4 for many architectural characteristics. Muscle mass, physiological cross-sectional area, muscle length, and fiber length were all significantly greater in digit 5. Proximal tendon length was also significantly longer in digit 5, and distal tendon length, as well as total tendon length, were significantly shorter in digit 5. Sarcomere length was shortest at the proximal end of the muscle and longest, 60–80%, toward the distal end. Fiber type distribution was about 60% FOG, 39% FG with only 1% SO fibers in all muscle bellies. Muscle-tendon modeling illustrated that peak force and maximal shortening velocity were greatest in digit 5. Inclusion of the tendon in the model resulted in a 10% shift of the force-length curve to longer lengths. Assuming muscle structure is matched to function, we speculate that digit 5 of the mouse EDL bears higher loads over a greater excursion during locomotion compared to the remaining digits.
Perineal Muscles and Their Innervation: Metabolic and Functional Significance of the Motor Unit
Authors: Ishihara A. , Hori A. , Roy R.R. , Oishi Y. , Talmadge R.J. , Ohira Y. , Kobayashi S. , Edgerton V.R.
Published: July 2008

Cross-sectional areas and succinate dehydrogenase (SDH) activities of muscle fibers in the rat levator ani (LA) and bulbocavernosus (BC) were determined and compared with those of the soleus (SOL) and superficial (TAs) and deep (TAd) portions of the tibialis anterior (TA). In addition, cell body sizes and SDH activities of spinal motoneurons innervating the LA and BC were examined. Histochemical myofibrillar adenosine triphosphatase (mATPase) staining reactions following alkaline and acid preincubations revealed that all the muscle fibers in the LA and BC were type IIB. Gel electrophoresis, however, showed that the LA and BC contained 2.9 and 2.4% type IIx myosin heavy chain (MHC) isoform, respectively. Immunohistochemical analyses using MHC antibodies showed that the muscle fibers in the LA and BC had types IIx + IIa (–3%) or type lib MHC isoforms. The mean fiber cross-sectional areas in the LA and BC were significantly smaller than those in the SOL, TAs, or TAd. The mean fiber SDH activities in the LA and BC were significantly lower than those in the SOL or TAd, and similar to TAs. The population of alpha motoneurons innervating the LA and BC had similar SDH activities, irrespective of their cell body sizes. These data indicate that the LA and BC are comprised of a relatively homogeneous population of small, fast and low oxidative fibers innervated by a relatively homogeneous population of spinal motoneurons. These characteristics of the muscle fibers and motoneurons are consistent with their function in short, high-intensity activities.
Effects of Conjugated Estrogens with or without Medroxyprogesterone Acetate on Mammary Carcinogenesis, Uterine Adenomyosis and Femur in Mice
Authors: Sakamoto S. , Mori T. , Shinoda H. , Sassa S. , Koyama T.
Published: July 2008

Although combined hormone replacement therapy using estrogens and progestins reduces the risk of endometrial cancer in postmenopausal women, it has been unclear whether the combined therapy is associated with an alteration of the risk of mammary cancer. Virgin mice of the SHN strain, which has a high potential for the development of mammary cancer and uterine adenomyosis, were given diets containing conjugated estrogens with or without medroxyprogesterone acetate for 230 days. The combined administration of conjugated estrogens and medroxyprogesterone acetate completely suppressed the development of uterine adenomyosis with a decrease in uterine thymidylate synthetase activity, significantly enhanced the bone mineral density in the femur and slightly shortened the latent period of mammary carcinogenesis.
Description of Two Types of Mammosomatotropes in Mink (Mustela vison) Adenohypophysis: Changes in the Population of Mammosomatotropes under Different Physiological Conditions
Authors: Vidal S. , Román A. , Moya L.
Published: July 2008

The present study was undertaken to clarify the existence of mammosomatotropes (MS cells) in the mink adenohypophysis and their possible involvement in the interconversion of mammotrope and somatotrope cells under different physiological conditions: prepubertal, pubertal and adulthood. Electron microscope immunocytochemistry was used to detect growth hormone (GH) and prolactin (PRL) immunoreactivities in the anterior pituitary gland of mink. Primary antisera raised in rabbit (human anti-GH, NIDDK-AFP-1613102481; human anti-PRL, NIDDK-AFP-55781789) were localized with appropriate species-specific antisera coupled to colloidal gold particles of different sizes. MS cells were most frequently observed in adult mink. Double labeling for GH and PRL was presented in two types of MS cells. MS, cells, observed only in adults, showed an irregular morphology, with many cytoplasmic processes. Within their cytoplasm there were numerous rounded secretory granules of approximately 135 nm mean diameter. In MS, cells three types of secretory granules were identified. The most numerous contained only PRL. The least frequent contained only GH and the third type contained GH and PRL and appeared in an intermediate quantity. MS2 cells, observed in all age groups, presented a rounded morphology. These cells had a voluminous cytoplasm which showed little development of the organdies and contained a large number of rounded and very electron-dense secretory granules which measured about 160 nm mean diameter. Within MS, cells two types of secretory granules, according to their immunolabeling, were observed. Monohormonal granules containing GH were the more abundant while bihormonal granules, containing GH and PRL, were present to a lesser degree. Data presented in this report suggest that MS cells could play a role in the interconversion of somatotropes into mammotropes in mink.
Localization of β-D-Galactosidase Activity in Semithin Epon Sections of Embryonic Tissues Using Differential Interference Contrast Optics
Authors: Poggi P. , Icaro-Cornaglia A. , Coletta M. , Kelly R. , Cossu G.
Published: July 2008

In the present study we describe a method for the histochemical demonstration of β-D-galactosidase activity on tissue sections processed for light microscopy at high resolution. 5-Bromo-indolyl-β-D-galactopyranoside (Bluo-Gal) was utilized as an indigogenic method for the demonstration of Escherichia coli β-D-galactosidase reporter gene activity whose expression was studied in a transgenic line where the enzyme, with a nuclear localization signal (nlacZ), is under the transcriptional control of a striated muscle-specific promoter. At the light-microscopic level, by using Differential Interference Contrast (DIC) optics, the reaction product was detected as precipitates in the form of fine birefringent crystals. These were located around and inside the nuclei of β-gal-expressing cells. This simple method allows an easy and rapid identification of few or even one labeled cell(s) within large microscopic fields (whole embryos) and the labeled cell(s) can be evaluated both morphologically and quantitatively.
Corticosterone Induces Hypoactivity of Prolactin Immunoreactive Cells
Authors: Carretero J. , Rubio M. , Sánchez F. , Cabo J.J. , Vázquez G. , Santos M. , Pérez R.M. , Vázquez R.
Published: July 2008

In order to determine whether corticosterone regulates activity of rat lactotrophs by acting directly at the pituitary level, immunohistochemical studies were carried out in adrenalectomized rats, subjected or not to treatment with corticosterone or colchicine, and in monolayer cultures after incubation with corticosterone. Adrenalectomy increased cellular and nuclear areas (p < 0.01) of prolactin-immunoreactive cells without affecting their cytoplasmic area. Similar results were found in adrenalectomized and colchicine-treated animals. Corticosterone reversed the effects of adrenalectomy, although normal values were partially reversed. In cultured pituitary cells, exposure to corticosterone reduced numerical density and cellular, cytoplasmic and nuclear areas with respect to control dishes. Morphological differences in shape, arrangement and nuclear features were observed after treatment with corticosterone. These results demonstrate an inhibitory effect of corticosterone on the activity of rat pituitary prolactin cells and suggest that corticosterone induces hypoactivity by acting on the pituitary prolactin cells of male rats.
Organization of the Hypobranchial Motor Column of the Clearnose Skate, Raja eglanteria, with Comparisons to Tetrapods
Authors: Sperry D.G. , Boord R.L.
Published: July 2008

Motoneurons that supply the clearnose skate’s hypobranchial musculature, via the occipital nerve and first seven ventral spinal nerve roots, are located within a column that extends from a level just caudal to the obex through the corresponding rostral spinal cord segments. Individual muscle motoneuron pools within the column are considerably intermingled and overlap. Comparisons with tetrapods, particularly mammals, where the hypobranchial musculature is greatly modified, reveal general conserved features. The motor column’s multisegmental organization is retained although, in mammals, the column begins rostrally at medullary levels, where hypobranchial muscle motoneurons are intimately associated with motoneurons to lingual muscles, and it is restricted caudally to fewer spinal cord segments. In addition, despite an intermingling of motoneurons that supply individual hypobranchial muscles there is a shared rostrocaudal sequence of the motor pools. Rostral most hypobranchial motoneurons supply the most ventral and anterior muscles (i.e., m. coracomandibularis, and likely m. coracohyoideus, of skate and the suprahyoid musculature, m. geniohyoideus, of tetrapods). Caudal hypobranchial motoneurons supply the skate’s mm. coracohyomandibularis, coracoarcualis communis and coracobranchialis and the tetra-pod’s entire infrahyoid muscle complex. The intermingling of multisegmental motoneuron populations innervating different hypobranchial muscles might be attributed to intermixing of premuscle mesoderm derived from several postotic somites but the musculotopic organization along the rostrocaudal axis indicates that pre- and posthyoid muscle mesoderm may partially keep its identity during its migration to the floor of the pharynx and oral cavity.
Microvascularization in Trigeminal Ganglion of the Common Tree Shrew (Tupaia glis)
Authors: Kongstaponkit S. , Pradidarcheep W. , Toutip S. , Chunhabundit P. , Somana R.
Published: July 2008

Since there is only a limited number of studies of the blood supply to the trigeminal ganglion (TG) in mammalian species, the TG from 16 common tree shrews (Tupαiα glis) were investigated by light microscope, transmission electron microscope (TEM) and the corrosion cast technique in conjunction with scanning electron microscope (SEM). It was found that the TG contained clusters of neurons in the peripheral region whereas the bundles of nerve fibers were located more centrally. Each ganglionic neuron had a concentric nucleus and was en-sheathed by satellite cells. It was noted that blood vessels of a continuous type were predominantly found in the area where the neurons were densely located and were much less frequently observed in the area occupied by nerve fibers. With TEM, the TG was shown to be mainly associated with large neurons containing big nuclei and prominent nucleoli. The blood supply of the TG is derived from the most rostral branch of the pontine artery, from the stapedial artery or sometimes from the supraorbital artery, and from the accessory meningeal artery which is a branch of the maxillary artery passing through the foramen ovale. These arteries give off branches and become capillary networks in the ganglion before draining blood to the peripheral region. The veins at the medial border drained into the cavernous sinus directly or through the inferior hypophyseal vein, while those at the lateral side of the ganglion carried the blood into the pterygoid plexus via an accessory meningeal vein. The veins along the trigeminal nerve root joined the posterior part of the cavernous sinus. These studies establish a unique anatomical distribution of the TG blood supply in the tree shrew and the utility of the cast/SEM technique in discerning detailed features of the blood supply in the nervous system.
A Generic Morphological Model of the Anatomic Variability in the M. flexor digitorum profundus, M. flexor pollicis longus and Mm. lumbricales complex
Authors: Leijnse J.N.A.L.
Published: July 2008

In the present study a generic model is presented of the anatomic variability in the muscle group formed by the m. flexor digitorum profundus, m. flexor pollicis longus and mm. lumbricales. This model provides a hypothesis about the structural causes of the frequent interdependence of tendons and muscle bellies in this muscle group. The model considers the muscle group as composed of two simple elementary building blocks: the monogastric contractile units of the FDP-FPL, and the digastric contractile elements of the lumbrical, and shows that these units can be assembled into complex entities, to which in reality a third structural element, the synovial membranes, not discussed in the present paper, adds a further complexity. The model allows to generate homologues of the existing anatomical variants, which are illustrated by typical dissection results. The present study should be of relevance to the morphologist, embryologist, surgeon, and musician/pedagogue. To the morphologist, it presents an alternative method of description or understanding of anatomic variability, based on (i) the ‘atomary’ concept that the anatomic structure is assembled from simple basic elements, and (ii) the local spatial constraints. To the embryologist, it raises the question to what degree the ‘atomary’ anatomical components of this model, which describes the macroscopic anatomy of the muscle group in detail, have an embryological basis. To the surgeon, the study presents detailed information about the scope of the variability in the deep flexor group, and the nature of its intertendinous connections. To the musician/pedagogue, it presents a visual illustration of the congenital interdependence of the muscles and tendons of an important finger motor group, as a possible cause of lack in finger independence which may hamper a fluent instrumental technique.
Radiographical Assessment of Interphalangeal Rotation in the Evaluation of Equine Digital Conformation
Authors: Caudron I. , Grülke S. , Gabriel A. , Serteyn D.
Published: July 2008

This study is a part of a work to design a radiographical method to objectively define the conformation of an equine digit and to assess the individual appropriate trimming of a horse. Various angles were measured directly from the phaangeal bones. The authors observed that the bone relief of the sesamoid ligament insertions on the proximal phalanx was an essential landmark to determine the phalangeal alignment. The same angles were measured from specific radiographs and made it possible to quantify the rotation imposed to the proximal phalanx. The authors also noticed that the phalangeal rotation had little influence on the radiographic image of articular asymmetry.
Liver Development in the Rat during the Embryonic Period (Carnegie Stages 15–23)
Authors: Godlewski G. , Gaubert-Cristol R. , Rouy S. , Prudhomme M.
Published: July 2008

Hepatic and biliary structures appearing during embryonic Carnegie stages 15–23 were analyzed in OFA rat embryos. The group of rats with crown rump length 7.5–16 mm and 12.8–16 days after coitus yielded 55 specimens (23 of stages 15–16, 20 of stages 17–18, 9 of stages 19–22 and 3 of stage 23). The embryos were submitted to serial histological sections with graphic reconstructions. From stage 15 to the end of the embryonic period, the hepatic gland and its vascular channels (transverse portal sinus and hepatocardiac veins) presented considerable enlargement while hematopoietic function appeared. At stage 17, occlusion due to epithelial proliferation was evident in the hepatic duct. At stage 18, the duct became recanalized and assured the continuity between liver cells and gut. From stage 18 to 23, biliary ductules developed in periportal connective tissue forming ductal plates which received biliary caniculi. Except for the gallbladder which is never present in the rat, similarity and presence of the same hepatic structures in man and in the rat during the embryonic period stages 15–23 suggest that the rat is a good experimental model for liver development and will be useful in the understanding of congenital anomalies.
Comparison of the Bone Robusticity Index and Bone Weight/Bone Length Index with the Results of Bone Densitometry and Bone Histomorphometry in Experimental Studies
Authors: Monteagudo M.D. , Hernández E.R. , Seco C. , Gonzalez-Riola J. , Revilla M. , Villa L.F. , Rico H.
Published: July 2008

In experimental studies of bone in rats, two morphometric indices reflecting bone density have been proposed, the bone robusticity index and bone weight/ bone length index. In rats, the bone mineral content (BMC) and bone mineral density (BMD) of a selected bone can be determined using dual-energy X-ray absorptiometry (DXA); bone volume can be measured by histomorphometry and other techniques. This study was undertaken to compare two morphometric indices (bone robusticity and bone weight/bone length) with the results of DXA and histomorphometry. Forty female Wistar rats (100 days old, mean weight 239 ± 12 g) were studied: 20 controls and 20 ovariectomized rats (OVX). The morphometric indices and BMD differed significantly (Friedman test) in the overall group of rats; no differences were observed in the control group, but significant differences were apparent in the OVX group (p < 0.0001). The morphometric indices correlated more closely with BMC than with BMD; the femur length/ femur weight index had closer correlations than the robusticity index. Nonetheless, both morphometric indices differed significantly from BMD determined by DXA under abnormal conditions, which makes them unreliable for use in these circumstances.
A Comparison of the Innervation Characteristics of the Lateral Spinal Ligaments between Normal Subjects and Patients with Adolescent Idiopathic Scoliosis
Authors: Jiang H. , Greidanus N. , Moreau M. , Mahood J. , Raso V.J. , Russellb G. , Bagnall K.
Published: July 2008

Evidence is rapidly accumulating to suggest that general proprioceptive dysfunction might be a major contributing factor in the development of adolescent idiopathic scoliosis (AIS). The innervation of appropriate ligaments which has been shown to be involved in proprioceptive feedback mechanisms, has also been suggested to play a part in this sensory dysfunction. Accordingly, this study compared the innervation characteristics of lateral spinal ligaments from patients with AIS to similar measurements from control subjects. Using an antibody to neurofilament protein, Ruffini corpuscles, small and large nerve bundles, and free nerve endings were identified and their numbers and distribution patterns compared. In the control group, the innervation was found to be symmetrical between left and right sides but was more concentrated in the ventral portion of each ligament. No apparent morphological defect of the innervation was found in the lateral spinal ligaments of the scoliosis patients but the innervation densities of Ruffini corpuscles, single nerve fibres and total neural elements were significantly lower (p < 0.01) than those found in normal subjects. These results suggest a possible mechanism for the production of AIS and warrant further study.
Characterization of the Inner Enamel Epithelium in the Enamel-Free Area Based on the Ability to Secrete Enamel Protein Demonstrated by in situ Hybridization and Immunohistochemistry
Authors: Yamamoto H. , Sasaki J. , Matsuura J. , Nomura T. , Sato E.F. , Shimokawa H. , Ishizeki K. , Nawa T.
Published: July 2008

Both the expression of amelogenin mRNA and secretion of amelogenin were investigated in rat molars by in situ hybridization and immunohistochemistry. Probes were designed by multiple-labeling of oligonucleotide probes for in situ hybridization. Amelogenin mRNA first appeared in differentiating ameloblasts of the distal region and some inner enamel epithelial cells of enamel-free area (EFA cells) of the second cusp at postnatal day 0. At the same time, amelogenin protein was detected in the extracellular matrix between dentin and differentiating ameloblasts and in some EFA cells of the second cusp. At postnatal day 1–3, amelogenin was expressed in the secretory ameloblasts, and in the matrix beneath these cells. Both amelogenin mRNA and amelogenin were detected in the EFA cells and their extracellular matrix. After postnatal day 5, amelogenin mRNA and amelogenin were detected in the secretory ameoloblasts and extracellular matrix in the enamel-forming region, respectively. At this time, amelogenin mRNA was not detected in the EFA cells, but a small amount of amelogenin was found in the matrix beneath the EFA cells. These findings suggest that EFA cells differentiate into amelogenin-secreting cells, i.e. ameloblasts, but that the secretion lasts for only a short period at the early stage of tooth development.
The Sympathetic Nerves of the Parasellar Region: Pathways to the Orbit and the Brain
Authors: Weninger W.J. , Müller G.B.
Published: July 2008

Sympathetic nerves innervate targets in the orbit and the brain. They issue from the superior cervical ganglion and reach the parasellar region via the internal carotid nerve. Information on their further parasellar course and distribution is scant and contradictory. In this study the parasellar sympathetic pathways of 30 human infants and 6 human fetuses were investigated by microdissection and histologically. A common parasellar sympathetic trunk, which reunites all the nerve fibers emanating from the lateral and medial internal carotid plexus, is described as well as its further divisions. It was found that the posterior knee of the infant carotid siphon is free of large sympathetic nerve bundles. In addition a ganglion is described, which is situated in the parasellar adipose body. It is reached by nerve fibers coming from the parasellar sympathetic pathways. Fibers that issue from this ganglion join the periorbita and the orbital muscle of Müller. These anatomical facts are of immediate importance for preventing nerve damage during cavernous sinus surgery. Furthermore, the study improves the anatomical knowledge of the parasellar region and suggests a new concept for the innervation of the orbital muscle.
3D Chaotic Model for Subgrid Turbulent Dispersion in Large Eddy Simulations
Authors: Lacorata Guglielmo , Mazzino Andrea , Rizza Umberto
Published: July 2008

A 3D multiscale kinematic velocity field is introduced as a model to simulate Lagrangian turbulent dispersion. The incompressible velocity field is a nonlinear deterministic function, periodic in space and time, that generates chaotic mixing of Lagrangian trajectories. Relative dispersion properties, for example Richardson’s law, are correctly reproduced under two basic conditions: 1) the velocity amplitudes of the spatial modes must be related to the corresponding wavelengths through the Kolmogorov scaling and 2) the problem of the lack of a “sweeping effect” of the small eddies by the large eddies, common to kinematic simulations, has to be taken into account. It is shown that, as far as Lagrangian dispersion is concerned, the model presented herein can be successfully applied as an additional subgrid contribution for large eddy simulations of the planetary boundary layer flow.
Stably Stratified Flows: A Model with No Ri(cr)*
Authors: Canuto V. M. , Cheng Y. , Howard A. M. , Esau I. N.
Published: July 2008

A large set of laboratory, direct numerical simulation (DNS), and large eddy simulation (LES) data indicates that in stably stratified flows turbulent mixing exists up to Ri ∼ O(100), meaning that there is practically no Ri(cr). On the other hand, traditional local second-order closure (SOC) models entail a critical Ri(cr) ∼ O(1) above which turbulence ceases to exist and are therefore unable to explain the above data. The authors suggest how to modify the recent SOC model of Cheng et al. to reproduce the above data for arbitrary Ri.
Tracking Gravity Waves in Baroclinic Jet-Front Systems
Authors: Lin Yonghui , Zhang Fuqing
Published: July 2008

Using a two-dimensional Fourier decomposition and a four-dimensional ray-tracing technique, the propagating characteristics and source mechanisms of mesoscale gravity waves simulated in idealized baroclinic jet-front systems are investigated. The Fourier decomposition successfully separates the simulated gravity waves from a complex background flow in the troposphere. Four groups of gravity waves in the lower stratosphere are identified from the spectral decomposition. One is a northward-propagating short-scale wave packet with horizontal wavelength of ∼150 km, and another is a northeastward-propagating medium-scale wave packet with horizontal wavelength of ∼350 km. Both of these are most pronounced in the exit region of the upper-tropospheric jet. A third group exists in the deep trough region above (and nearly perpendicular to) the jet, and a fourth group far to the south of the jet right above the surface cold front, both of which are short-scale waves and have a horizontal wavelength of ∼100–150 km.

Ray-tracing analysis suggests that the medium-scale gravity waves originate from the upper-tropospheric jet-front system where there is maximum imbalance, though contributions from the surface fronts cannot be completely ruled out. The shorter-scale, northward-propagating gravity waves in the jet-exit region, on the other hand, may originate from both the upper-tropospheric jet-front system and the surface frontal system. The shorter-scale gravity waves in the deep trough region across the jet (and those right above the surface cold fronts) are almost certain to initiate from the surface frontal system. Ray-tracing analysis also reveals a very strong influence of the spatial and temporal variability of the complex background flow on the characteristics of gravity waves as they propagate.