bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fiber‐type composition of hindlimb muscles in the turtle, Pseudemys (Trachemys) scripta elegans
Authors: Laidlaw Douglass H. , Callister Robert J. , Stuart Douglas G. 
Published: February 2005

AbstractA description is provided of the fiber‐type composition of several hindlimb muscles of the adult turtle, Pseudemys (Trachemys) scripta elegans. In addition, cross‐section areas of each fiber type and an estimation of the relative (weighted) cross‐section area (wCSA) occupied by the different fiber types are also provided. Seven muscles were selected for study, based on their suitability for future neurophysiological analysis as components of the segmental motor system, and on their homologies with muscles in other vertebrates. The test muscles were iliofibularis (ILF), ambiens (AMB), external gastrocnemius (EG), extensor digitorum communis (EDC), flexor digitorum longus (FDL), tibialis anterior (TA), and peroneus anterior (PA). Serial sections of these muscles were stained for myosin adenosine triphosphatase (ATPase), NADH‐diaphorase, and alpha‐glycerophosphate dehydrogenase (α‐GPDH), thereby enabling fiber‐type classification on the basis of indirect markers for contraction speed and oxidative (aerobic) vs. glycolytic (anaerobic) metabolism. All muscles contained three fiber types: Slow oxidative (SO; possibly including some non‐twitch tonic fibers); fast oxidative glycolytic (FOG); and fast glycolytic (Fg). There were at least 30% FOG and 50% FOG + Fg fibers in the seven muscles, the extreme distributions being the predominantly glycolytic ILF vs. the predominantly oxidative FDL muscle (ILF—15.5% SO, 35.2% FOG, 49.3% Fg vs. FDL—49.1% SO, 41.1% FOG, 9.8% Fg). As in other species, the test muscles exhibited varying degrees of regional concentration (compartmentalization) of the different fiber types. This feature was most striking in ILF. Pronounced compartmentalization was also observed in AMB, EG, PA, TA, and EDC, whereas the distribution of fiber types in the highly oxidative FDL was homogeneous. In five of the seven muscles, fiber size was ranked with Fg > FOF > SO. In terms of wCSA, which provides a coarse‐grain measure of the different fiber types' potential contribution to whole muscle peak force, all muscles exhibited a higher Fg and lower SO contribution to cross‐section area than suggested by their corresponding fiber‐type composition. The largest relative increases in wCSA vs. fiber‐type composition were in the ILF and AMB muscles. We conclude that the turtle hindlimb provides some interesting possibilities for testing for a division of labor among different muscles during different movements (e.g., sustained vs. ballistic), and for study of the behavior of the different fiber (and motor unit) types under normal and perturbed conditions. The relationships between the present results and previous findings on homologous muscles of the mammalian (cat, rat) and reptilian (lizard) hindlimb are discussed. © 1995 Wiley‐Liss, Inc.
Occurrence of ampulla in the ductus deferens of the Indian garden lizard Calotes versicolor daudin
Authors: Akbarsha M. A. , Meeran M. M. 
Published: February 2005

AbstractDuring the breeding season, the terminal end of the ductus deferens of Calotes versicolor appears swollen and is comparable to the ampulla of the mammalian ductus deferens. Its anatomy was studied from paraffin sections. It differentiates along its length into five zones. The first has thick smooth muscle and pesudostratified epithelium; the second has luminal trabeculae with an epithelium showing evidence of secretory activity; the third has the epithelial mucosa abutting against the smooth muscle in the form of pocketlike indentations; the fourth has crypts between epithelial folds; and the fifth zone is a sphincter. The anatomy of this ampullary region is indicative of secretory as well as spermatophagous roles. It undergoes seasonal change and appears to be androgen‐dependent. © 1995 Wiley‐Liss, Inc.
Ampullary organs, pit organs, and neuromasts of the chinese giant salamander, Andrias davidianus
Authors: Hong Cheng , Shi‐Qiang Huang , Heatwole Harold 
Published: February 2005

AbstractThe lateral‐line sense organs in the skin of larval, juvenile and adult salamanders (Andrias davidianus) were examined by light and scanning electron microscopy. In addition to mechanoreceptive neuromasts, there are electroreceptive ampullary organs. Anatomically, the latter are similar to the ampullary organs of some other urodeles. In the giant salamander they occur only in larvae and disappear after metamorphosis. Neuromasts are arranged in lines and in different orientations that apparently maximize directionality. © 1995 Wiley‐Liss, Inc.
The opisthonephros of Rana esculenta (Anura). I. Nephron development
Authors: Richter Susanne 
Published: February 2005

AbstractThe development of opisthonephric nephrons in Rana esculenta generally follows the vertebrate scheme: mesenchymal cells from a blastemal cap that develops into an epitheloid, a comma‐shaped, then an S‐shaped body. The S‐shaped body stage is followed by nephron stages I–IV. A standard pattern of nephrogenesis is maintained up to nephron stage I. In later stages (nephron stages II–IV) the arrangement of tubule loops and the position of the renal corpuscle depends on the space available in the kidney. As in mammals, anuran nephrogenesis is determined by coordinated differentiation processes: (1) induction, (2) cell polarization and proliferation, (3) morphogenetic processes, and, finally, 4) segmentation. It is further supported by growth processes of renal blood vessel analagen adjoining the nephron analoge. Ingrowth of glomerular capillary sprouts into the capsule analage is important for glomerulogenesis and differentiation of the adhesive zone. © 1995 Wiley‐Liss, Inc.
Distribution of cranial and rostral spinal nerves in tadpoles of the frog discoglossus pictus (Discoglossidae)
Authors: Scholsser Gerhard , Roth Gerhard 
Published: February 2005

AbstractWe studied the peripheral nervous system of early tadpoles of the frog Discoglossus pictus using whole‐mount immunohistochemistry. Double‐labeling of muscles and nerves allowed us to determine the innervation of all cranial muscles supplied by the trigeminal, facial, glossopharyngeal, vagal, and hypoglossal nerves. The gross anatomical pattern of visceral, cutaneous, and lateral‐line innervation was also assessed. Most muscles of the visceral arches are exclusively supplied by posttrematic rami of the corresponding branchiomeric nerves, the only exceptions being some ventral muscles (intermandibular, interhyoid, and subarcual rectus muscles). In the mandibular arch, the pattern of motor ramules of the trigeminal nerve prefigures in a condensed form the adult pattern, but the muscles of the hyoid arch are innervated by ramules of the facial nerve in a pattern that differs from that of postmetamorphic frogs. With respect to the nerves of the branchial arches, pretrematic visceral rami, typical of other gnathostomes, are absent in D. pictus. Instead, we find a separate series of posttrematic profundal visceral rami. Pharyngeal rami of all branchial nerves contribute to Jacobson's anastomosis. We provide a detailed description of the lateral‐line innervation and describe a new ramus of the middle lateral‐line nerve (ramus suprabranchialis). We confirm the presence of a first spinal nerve and its contribution to the hypoglossal nerve in D. pictus tadpoles. © 1995 Wiley‐Liss, Inc.
Dorsal lingual epithelium of Platemys pallidipectoris (Pleurodira, Chelidae)
Authors: Beisser Christian J. , Weisgram Josef , Splechtna Heinz 
Published: February 2005

AbstractScanning electron microscopy reveals that the flat tongue of Platemys pallidipectoris has shallow grooves and no lingual papillae. The surface of the tongue is covered with dome‐shaped bulges, each corresponding to a single cell. Short microvilli are distributed over the cell surface. Light microscopy shows a stratified cuboidal epithelium with an underlying strong connective tissue. Transmission electron microscopy indicates four layers. The basal cells of the epithelium are electron‐translucent and have a large central nucleus and a cytoplasm with keratin tonofilaments. Plasma cells with abundant rough endoplasmic reticulum and mitochondria occur in the basal layer. Production of secretory granules begins in the more electron‐dense intermediate layers and increases as the cells move toward the surface. The membranes of the cells of the deep intermediate layer form processes that project into relatively wide intercellular spaces. In the superficial intermediate layer, the cytoplasm of the cells contains numerous fine granules; these increase in number but not in size in more distal layers. The cells of the surface layer are electron‐translucent with a round nucleus. Contents of their fine granules are secreted into the oral cavity. © 1995 Wiley‐Liss, Inc.
On the geometry and mechanics of tooth position in the white shark, Carcharodon carcharias
Authors: Powlik James J. 
Published: February 2005

AbstractThe teeth of captured specimens, of prepared museum specimens, and of high‐speed videotape images of the white shark, Carcharodon carcharias, were compared with respect to (1) deviation of each tooth from the animal's midline and (2) the crown angle of the functional teeth along the jaw margin. Tooth position was measured either directly using a meter stick apparatus or derived from tracings of the video footage. Tooth positions were not statistically unique in any region of the upper or lower jaw but demonstrated less variability in crown angle within 30° of the midline (71.48° ± 10°). Videotape analysis of feeding sharks indicated an 8.7° increase in crown angle of the centermost teeth during bites where the jaws were closed through an angle of 20–35° and a 15.7° reduction in this same parameter during jaw adduction through 35° or more. Such changes in tooth orientation (relative to the rear of the buccal cavity) are ascribed to flexure of the cartilaginous jaws and cranium by the cranial musculature and possibly also to sliding of the tooth bed over the jaw. Outward rotation of the teeth and jaw rami describes a plucking action during feeding or prey sampling, while larger bites rotate the frontmost teeth inward towards the gullet. Functionally, this may make the teeth more effective at grasping small prey items or gouging chunks from larger prey. However, testing of the load required to remove teeth showed no significant increase in tensile resistance with reduced crown angle. © 1995 Wiley‐Liss, Inc.
Histological examination of the effects of corticosterone in larvae of the western toad, Bufo boreas (Anura: Bufonidae), and the oriental fire‐bellied toad, Bombina orientalis (Anura: Discoglossidae)
Authors: Hayes Tyrone B. 
Published: February 2005

AbstractThe effects of corticosterone (CORT)‐treatment on various tissues were examined in two species of anuran larvae, the discoglossid Bombina orientalis, and the bufonid Bufo boreas. Corticosterone was administered directly into aquarium water for 15 days. After treatment, histological analyses were conducted on skin, gut, spleen, thymus, and neural and muscle tissue. Corticosterone treatment prevented sloughing of the skin, which resulted in a build‐up of stratum corneum, and inhibited the development of gland nests and the subsequent formation of dermal granular and mucous glands in both species. Corticosterone treatment also decreased epithelial folding in the gut and caused vesiculation of the gut epithelial cells. The thymus of CORT‐treated animals was significantly reduced in size (P < .05) and cell density (P < .05), and the spleen of CORT‐treated animals was completely involuted. The brain and pituitary of CORT‐treated animals had a decreased cell density (P < .05) and many pyknotic cells. An examination of muscle revealed that muscle fibers of CORT‐treated animals had a decreased cross‐sectional area (P < .05). The dose of CORT used (1.1 μM) was within the range used in other studies in the literature and resulted in tissue levels within the range experienced by larvae at metamorphic climax. Thus, this study is appropriate to address the histological effects of CORT in experimental manipulations and the role of increasing CORT at metamorphic climax. The data suggest that increasing endogenous CORT at metamorphosis may be involved in degeneration of larval tissue, prior to regeneration, which is stimulated by thyroid hormones. © 1995 Wiley‐Liss, Inc.
Early changes in material properties of rabbit articular cartilage after meniscectomy
Authors: Hoch D. H. , Grodzinsky A. J. , Koob T. J. , Albert M. L. , Eyre D. R. 
Published: February 2005

AbstractWe have correlated early material and biochemical changes in articular cartilage in a surgical model for cartilage degeneration. Medial meniscectomy was performed on the left knee of 17 adult, female New Zealand white rabbits. The equilibrium Young's modulus of cartilage was assessed by an indentation test in situ at defined sites on the medial and lateral tibial plateaus of the operated and control knees; the cartilage was then excised and analyzed biochemically. Focal changes were consistently observed in the medial surface of the operated knee. The equilibrium modulus and the glycosaminoglycan content fell rapidly, reaching a minimum by 2 weeks after surgery; the lateral tibial surface was essentially unaffected. Six months after surgery, the glycosaminoglycan content had returned to normal and the modulus to near normal. Independent measurements on cored plugs from the medial surface 2 weeks after surgery revealed a significant decrease in both the dynamic stiffness and the streaming potential in the operated knee compared with the control. The findings suggest that normal ambulatory loads in vivo will deform the affected medial cartilage much more than normal. It remains to be seen if altered mechanical stresses are solely responsible for initiating and sustaining matrix remodeling by the chondrocytes.
In vivo growth plate stimulation in various capacitively coupled electrical fields
Authors: Brighton Carl T. , Pfeffer Glenn B. , Pollack Solomon R. 
Published: February 2005

AbstractThe right proximal tibial growth plates of adolescent New Zealand white rabbits were stimulated with various capacitively coupled electrical fields. Capacitor plates attached to plastic jigs placed over the proximal tibiae were connected to function generators which supplied sine wave signals of 60 kHz frequency and various voltages (2.5, 5, 10, and 20 V peak‐to‐peak). At 0 hand at 48 h, each animal was labeled with intravenously injected oxytetracycline. For the next 48 h, each right proximal tibial growth plate was stimulated with one of the above electrical signals. At the end of the 48 h of stimulation, the animals were sacrificed, and the tibiae were excised; histological sections of the proximal growth plate in each tibia were made, and the distance the labels moved away from the bone‐cartilage junction down into the metaphysis was measured under fluorescent microscopy. Results indicate that the rabbit growth plate can be consistently stimulated to statistically significant accelerated growth in a capacitively coupled electrical field. A dose‐response effect was noted, with 5 V peak‐to‐peak exhibiting maximum growth acceleration. Thus, the application of the proper capacitively coupled electrical field significantly stimulated the rabbit growth plate at voltage and current levels that are safe for human use.
Comparison of growth‐induced resorption and denervation‐induced resorption on the release of [3H]tetracycline, 45calcium, and [3H]collagen from whole bones of growing rats
Authors: Klein L. , Heiple K. G. , Stromberg B. V. 
Published: February 2005

AbstractThe major effect of immobilization during growth is a smaller bone mass induced by either an increased bone resorption or a decreased bone formation. Using a method of analyzing radioisotopic loss of [3H]tetracycline and [3H]collagen from bone prelabeled in vivo, we compared the amount of bone resorption due to immobilization with bone resorption induced by growth. One hind limb was denervated in growing male rats, 6 weeks of age, that had been chronically prelabeled with [3H]tetracycline, 45calcium, and [3H]proline. The total radioactivity of the whole femur and tibia/fibula from the denervated limb was compared with that from bones of the control limb at 0, 1, 2, 4, and 8 weeks after denervation. The effect of growth on bone formation was measured by net increases in bone length, volume, and mass of matrix and mineral. Experimental bones had a significantly smaller volume and mass. Bone resorption was much greater during growth modeling than during denervation. The additional bone resorption induced by denervation was a small fraction (one‐fourth) of the resorption induced by growth. Denervation during growth resulted in less bone being formed due to a smaller gain in matrix and mineral mass as a result of a reduction in bone formation.
Joint flexibilities in structurally normal girls and girls with idiopathic scoliosis
Authors: Mattson Gunilla , Haderspeck‐Grib Karol , Schultz Albert , Nachemson Alf 
Published: February 2005

AbstractSeven clinical measurements of joint flexibilities were made in 51 girls with untreated mild idiopathic scoliosis and 65 girls with structurally normal spines. Subject ages ranged from 10 to 16 years. Abilities to have the index finger passively extended, the wrist bent, and the elbow and the knee hyperextended, along with abilities to bend the trunk voluntarily forward and to the right and left sides, were measured. The girls with scoliosis in the mean either had the same flexibilities or were less flexible than the normal girls. The study provided no evidence that untreated mild idiopathic scoliosis occurs or progresses because of increased joint flexibilities.
Comparison of cartilage destruction between infectious and adjuvant arthritis
Authors: Smith R. Lane , Schurman David J. 
Published: February 2005

AbstractThe timing and molecular profile of cartilage destruction in Escherichia coli and Staphylococcus aureus infectious arthritis and killed Mycobacterium butyricum adjuvant arthritis are presented. Infectious arthritis was studied for 3 weeks; cartilage samples were analyzed at 2, 10, and 21 days. At 48 h postinfection, glycosaminoglycan content was reduced by 20% (p < 0.05) in E. coli infected knees and by 42% (p < 0.05) in tibial plateau cartilage of S. aureus infected knees. By the 3rd week of infection, glycosaminoglycan losses amounted to as much as 73% (p < 0.005). In comparison, collagen losses were not significant prior to the 3rd week of infection, at which time 42% (p < 0.05) was lost. Adjuvant arthritic tibial plateau cartilage was examined at 1, 3 and 12 weeks. Glycosaminoglycans decreased by 42% the 1st week, plateauing at 62% by the 3rd and 12th weeks. Collagen degradation began at 3 weeks (28% loss, p < 0.10) and by the 12th week was reduced by 49% (p < 0.005). Analysis of the individual species of glycosaminoglycan showed a parallel loss of chondroitin sulfate and keratan sulfate. Fractionation of glycosaminoglycans with respect to size produced no evidence of shortened chains in cartilage from infected joints. Hyaluronic acid losses were greatest when collagen was significantly decreased. The pattern by which chondroitin and keratan sulfates are lost demonstrates that a prominent feature of infectious and noninfectious inflammatory arthritis is a rapid loss of proteoglycan subunits that precedes collagen loss.
Compressive loads in the lumbar vertebral column during normal level walking
Authors: Cappozzo Aurelio 
Published: February 2005

AbstractThe longitudinal compressive load acting on the L3–L4 spinal motion segment was investigated during normal level walking for a range of speeds of progression. Forces were predicted using experimental data from photogrammetric measurements of upper body segmental motion and inertial properties, along with a biomechanical model of the trunk. A partial validation of the results was obtained using records of the electrical activity of the trunk muscles and intradiscal pressure information available in the literature. Experiments were carried out in five normal young male subjects. Results showed that the L3–L4 motion segment is subjected to cyclic compressive loads. The maximum and minimum values of this load vary with walking speed from approximately 1.0 to 2.5 and from 0.8 to 0.2 times body weight, respectively. Relevant peaks occur with a frequency ranging approximately from 1.3 to 2.5 Hz. Muscular action is mostly concentrated in the trunk extensors, which show a burst of activity at the time of ipsilateral toe‐off.
Correlation of histopathology and sulfated proteoglycans in human osteoarthritic hip cartilage
Authors: Goldberg Victor M. , Norby David P. , Sachs Barton L. , Moskowitz Roland W. , Malemud Charles J. 
Published: February 2005

AbstractThe histopathologic characteristics, in vitro proteoglycan and glycosaminoglycan biosynthesis, and proteoglycan content of osteoarthritic (OA) cartilage tissue types from human femoral heads obtained at the time of total joint replacement were compared. Articular cartilage from fibrillated or discolored cartilage surfaces demonstrated overlapping histopathologic patterns, while cartilage from osteophytic areas was distinct. 35SO4 from each of these three tissue types was found in two peaks of radioactivity on a Sepharose CL‐2B column. The average partition coefficient (Kav) of the first peak (peak I) was 0.07, while that of the second (peak II) was 0.63. Proteoglycan monomer predominated in discolored, fibrillated, and osteophytic OA cartilage in peak I. The hydrodynamic size on Sepharose CL‐2B of the synthetic proteoglycan monomer was the same for discolored, fibrillated, and osteophytic samples (Kav, 0.25–0.28). Discolored and fibrillated tissues showed a similar percentage of proteoglycan monomer in peak II, whereas osteophyte was reduced in proteoglycan monomer content in peak II. In addition, the endogenous proteoglycans extracted from each cartilage area were generally of a smaller hydrodynamic size than the newly synthesized peak I or proteoglycan monomer. Glycosaminoglycans were predominantly chondroitin 6‐sulfate. These results indicated that OA discolored and fibrillated cartilage tissue types from defined topographical areas of human femoral heads possessed neither unique histopathologic nor synthetic or endogenous proteoglycan characteristics. Osteophytic cartilage appeared more histopathologically distinct than either discolored or fibrillated OA cartilage, but synthesized proteoglycan monomer with similar hydrodynamic size to the other cartilage tissue types.
Articular cartilage deformation following experimental synovitis in the rabbit hip
Authors: Gershuni David H. , Kuei Steven C. 
Published: February 2005

AbstractThe development of transient synovitis in the hips of young children occurs quite frequently. This experiment examined the effects of a model synovitis on the deformability of articular cartilage of the immature rabbit hip. At 1, 2, 3, and 4 weeks following synovitis, there was an increase of cartilage deformability on both the acetabular and femoral sides of the joint. This increased deformability may alter force transmission to the underlying bone and its contained vascular structures.