bluuebunny/crossref_metadata_2025 huggingface dataset:
Localization of Calmodulin in perinuclear structures of spermatids and spermatozoa: A comparison of six mammalian species
Authors: Kann Marie‐Louise , Feinberg Jacqueline , Rainteau Dominique , Dadoune Jean‐Pierre , Weinman Serge , Fouquet Jean‐Pierre
Published: February 2005

The distribution of Calmodulin was examined during spermiogenesis and sperm epididymal maturation in rabbit, hamster, mouse, rat, monkey, and human. An affinity‐purified antibody to Calmodulin was used to characterize this protein in sperm extracts by immunoblot analysis. Post‐embedding immunogold procedures were used to localize Calmodulin at the ultrastructural level. The pattern of Calmodulin distribution was similar in the six species studied. A diffuse labeling was observed in round spermatids. Gold particles accumulated first in the subacrosomal layer of elongating spermatids. The perinuclear ring was also labeled. During the maturation phase of spermatids, Calmodulin labeling extended to the postacrosomal sheath. Dramatic changes occurred at spermiation so that in testicular sperm Calmodulin immunostaining was predominant in the postacrosomal sheath. Some labeling was still detected in restricted areas of the subacrosomal layer. This feature varied from species to species. Calmodulin location did not change during sperm epididymal maturation. A role for Calmodulin in the control of manchette development and regulation of subacrosomal actin aggregation state during spermiogenesis is proposed. The unique location of Calmodulin in the postacrosomal sheath of all species that have been studied in this work, together with the known presence of calcium in this area suggest a pivotal role for Calmodulin in sperm‐egg fusion process.
Effect of basicranial flexion on larynx and hyoid position in rats: An experimental study of skull and soft tissue interactions
Authors: Reidenberg Joy S. , Laitman Jeffrey T.
Published: February 2005

The mammalian upper respiratory tract is a functionally dynamic region involved in respiration, deglutition, and phonation. As the structures of this area (e.g., larynx, hyoid) are suspended from the basicranium, changes in basicranial shape may affect both their anatomy and function. Although skeletal/ soft tissue relationships have been examined through descriptive, comparative anatomy, these relationships have remained largely unexplored via experimental study. In this study, mechanical relationships between basicranial shape and positions of the larynx and hyoid bone are investigated experimentally. Skull base flexion was induced by surgically ablating the spheno‐occipital synchondrosis in 13‐day‐old rats. Lateral radiograms were taken at 40, 60, 80, 100, and 120 days, and angular measurements made of basicranial shape and positions of the larynx and hyoid bone. Statistical analysis shows significant differences between experimental and control groups for skull base, hyoid, and larynx angles, and negative (inverse) correlations for basicranial shape change vs. hyoid position, and basicranial shape change vs. larynx position. Results show induced basicranial flexion caused inferior displacement of the larynx and hyoid bone, thus indicating a direct, mechanical relationship between skeletal and soft tissues. These observations may aid in understanding the basic biological, pathological, and evolutionary interactions of hard and soft tissues of the upper respiratory region.
Relationship between the articular surface area of a bone and the magnitude of stress passing through it
Authors: Pal G. P. , Routal R. V.
Published: February 2005

The present study investigates the relationship between the articular area of a bone and the magnitude of the stress it resists. An attempt was also made to find the correlation between the development of a bone and its articular area. The material of the study consisted of a large number of dry, macerated, adult male skeletons. The articular surface area of the bones was measured with the help of a planimeter.

The magnitude of the force acting on the proximal articular surface of a bone is expected to go out of the bone through its distal articular surface in almost the same proportion. The present investigation is based on the assumption that if the articular area is related to the magnitude of stress, then the proximal and distal articular areas of a bone should also be correlated. A significant correlation was observed between the proximal and distal articular areas of axis vertebra; L4 and sacrum; and tibia‐fibula and talus. This indicated that the stress resisted by proximal and distal articular areas was in the same proportion. Similarly, a significant positive correlation between bone index and articular area in ribs, tibia, and laminae of vertebrae indicated that the bone mass (development) runs parallel to the articular area. Thus, the present investigation could reveal that the articular area and bone development are related to the stress acting on the bone.
Unusual mitochondria in the hepatocytes of rats treated with a vitamin B12 analogue
Authors: Tandler Bernard , Krahenbuhl Stephan , Brass Eric P.
Published: February 2005

Adult male rats were administered hydroxy‐cobalamin (c‐lactam) (HCCL), a vitamin B12 analogue, by means of osmotic mini‐pumps. The metabolic effects of HCCL, are similar to those produced by simple dietary deficiency of vitamin B12 (Frenkel et al., 1976), but the morphological alterations in hepatic mitochondria are quite different in the two treatments. In HCCL‐treated animals, hepatic mitochondria showed significant increases in number. In one rat, the hepatic mitochondria frequently had a single, elongated, circumferentially‐oriented crista, with the inner compartment being occupied by a greatly augmented matrix. Such organelles appeared to be capable of division, as indicated by medially‐partitioned forms. Numerous hooded mitochondria were present in the hepatic cells of the same animal. Almost every mitochondrion of whatever morphology was partially or completely shrouded by a cistern of rough endoplasmic reticulum. These mitochondrial morphological changes may be related to the chronic metabolic changes in this animal model of methylmalonic aciduria.
Physiological and pathophysiological pulmonary responses to inhaled nuisance‐like or fibrogenic dusts
Authors: Warheit David B. , Hansen John F. , Hartsky Mark. A.
Published: February 2005

A short‐term bioassay has been developed to assess pulmonary toxicity and predict pathological effects in animals exposed to aerosolized particulates. To test the reliability and predictive value of our bioassay, we have exposed rats to 2 materials with different biological activities. Rats were exposed for 1 or 3 days to selected concentrations of crystalline silica (a known fibrogenic dust), or to carbonyl iron (CI) particles (a material with activity reputedly similar to nuisance dusts). Pulmonary cells and tissues were evaluated at several time points after exposure. In a companion manuscript we reported that brief exposures of silica produced a sustained pulmonary inflammatory response, characterized by increases in biochemical indicators, whereas no significant effects were measured in CI‐exposed animals. In the current study, our results showed that although deposition patterns for the 2 dusts were similar (i.e., at alveolar duct bifurcations), brief doses of silica produced a sustained granulocytic inflammatory response at the sites of particle deposition, while CI particles were phagocytized and cleared from the lung by normal pulmonary macrophage mechanisms which included transport via the airway mucociliary escalator. Light, scanning, and transmission electron microscopy of silica‐exposed lung tissue revealed a chronically active pulmonary inflammatory response characterized by hyperplasia of type II alveolar epithelial cells and the infiltration of pulmonary macrophages and neutrophils into interstitial tissues and alveoli. The lesions were progressive leading to a granulomatous pneumonitis within 2 months postexposure. In contrast to the alterations in pulmonary tissues produced by silica, no CI‐related lesions were detected at any time postexposure. The results justify the utility of this bioassay as a reliable approach to evaluating the pulmonary toxicity of inhaled particulates.
FSH in testes of marmosets during development: Immunocytochemical localization and de novo biosynthesis
Authors: Garde Seema V. , Sheth Anil R. , Kulkarni Sujata A.
Published: February 2005

Immunocytochemical localization of FSH was carried out in various cell types of marmoset testes during development using antisera generated against intact as well as β‐subunit of human FSH. Significant differences in the intensity as well as distribution of FSH in various cell types were observed in neonatal, pubertal, and adult marmosets. Intensity of staining in Leydig cells was maximum at day 1 and in adults (1–3 years), whereas it was minimum at 3 months. In seminiferous tubules (Sertoli cells), FSH was present in trace amount until puberty and subsequently increased at maturity. Further studies demonstrate de novo biosynthesis of FSH‐like moiety in vitro by testicular tissue, which was age dependent.
Characterization of the endocrine cells in the pancreatic‐bile duct system of the rat
Authors: Park In‐Sun , Bendayan Moïse
Published: February 2005

Six types of endocrine cells showing immunolabelling against gut or pancreatic islet hormones were identified in the pancreatic‐bile duct system of the normal adult rat at the light and electron microscopic levels. They were located within the epithelial lining of the duct system from the intercalated portion to its duodenal opening. However, the distribution and frequency of each endocrine cell varied along the length of the duct system. While insulin, glucagon, somatostatin, and pancreatic polypeptide cells were widely distributed along the entire duct system, small numbers of cholecystokinin and serotonin cells were confined to the terminal portion. A considerable number of somatostatin cells were concentrated in gland‐like pouches of the terminal portion of the common pancreatic‐bile duct. When the accessory pancreatic duct was present, insulin, glucagon, and somatostatin cells were also found in its epithelial lining. Electron microscopically, the specific content of the secretory granules of all endocrine cells was confirmed by immunolabelling or cytochemical staining. Further the characteristics of the secretory granules of each endocrine cell type corresponded to those present in the same kind of endocrine cells in gut or pancreatic islet. The duct endocrine cells displayed a particular ultrastructural appearance. The “open type cells” were highly polarized, with their apical cytoplasmic process reaching the duct lumen, whereas “closed type cells” showed long basal cytoplasmic processes with no connection with the duct lumen. In general, insulin, and somatostatin cells were of the “open type,” while no morphological connection with the duct lumen was found for glucagon and pancreatic polypeptide cells. The presence of various duct endocrine cells with their particular ultrastructural appearance implies that they may take part in modulating the function of the duct system.
Position of the axillary nerve in the deltoid muscle
Authors: Kulkarni Roopa R. , Nandedkar Ashalata N. , Mysorekar V. R.
Published: February 2005

The relationship of the anterior branch of the axillary nerve to the deltoid muscle was studied on both sides in 66 adult cadavers. The nerve runs a course on the deep surface of the deltoid muscle about 2.2 cm above the midpoint on the vertical plane of the muscle.
Fibroblast contraction occurs on release of tension in attached collagen lattices: Dependency on an organized actin cytoskeleton and serum
Authors: Tomasek James J. , Haaksma Carol J. , Eddy Robert J. , Vaughan Melville B.
Published: February 2005

The generation of tension in granulation tissue undergoing contraction is believed to be a cell‐mediated event. In this study we used attached collagen lattices as a model system for studying the cellular mechanisms of tension generation by fibroblasts in an extracellular matrix. Fibroblasts in attached collagen lattices developed stress fibers, surface associated fibronectin fibrils, and a fibronexus‐like transmembrane association interconnecting the two structural components. Release of the attached collagen lattice from its points of attachment resulted in a rapid, symmetrical contraction of the collagen lattice. Rapid contraction occurred within the first 10 minutes after release of the lattice from the substratum, with greater than 70% of the contraction occurring within the first 2 minutes. Rapid contraction resulted in a shortening of the elongate fibroblasts and compaction of the stress fibers with their subsequent disappearance from the cell. Cytochalasin D treatment prior to release disrupted the actin cytoskeleton and completely inhibited rapid contraction. The removal of serum prior to release inhibited rapid contraction, while the re‐addition of serum restored rapid contraction. These results demonstrate that fibroblasts can develop tension in an attached collagen lattice and that upon release of tension the fibroblasts undergo contraction resulting in a rapid contraction of the collagen lattice. Fibroblast contraction is dependent upon an organized actin cytoskeleton and is promoted by the presence of serum.
Immunocytochemical localization of sulfated glycoprotein‐1 (SGP‐1) and identification of its transcripts in epithelial cells of the extratesticular duct system of the rat
Authors: Hermo L. , Morales C. , Oko R.
Published: February 2005

The localization of sulfated glycoprotein‐1 (SGP‐1) in the extratesticular duct system was analyzed using an affinity purified antibody raised against the protein in conjunction with light (LM) and electron (EM) microscope immunocytochemistry. In the LM an intense immunoperoxidase reaction product was observed over the cytoplasm of Sertoli cells as well as over the tails of late spermatids. The rete epithelial cells and noncilliated cells of the efferent ducts also showed an intense uniform reaction over their entire cytoplasm. In the EM, immunogold labeling was noted over the entire endocytic apparatus of these cells including coated pits, endosomes, multivesicular bodies, and secondary lysosomes. Since there was no labeling of the luminal contents including sperm along the epididymis, it was concluded that the Sertoli‐derived SGP‐1 must dissociate from the sperm and be taken up by epithelial cells at the level of the rete testis and efferent ducts.

In all regions of the epididymis, except the cauda, the principal cells showed, in the LM, an intense reaction over bodies of various shapes and sizes in their supranuclear region; this corresponded in the EM to a strong immunogold labeling of secondary lysosomes. No labeling was noted, however, over coated pits, endosomes, or pale multivesicular bodies, suggesting that SGP‐1 was not being endocytosed from the lumen. Similar observations were noted for the epithelial clear cells along the entire epididymis. In the cauda epididymidis, principal cells presented a weak immunolabeling of their secondary lysosomes.

Northern blot analysis revealed a strong 2.6 Kb band corresponding to the mRNA of SGP‐1 in the efferent ducts and all regions of the epididymis with the exception of the cauda. Coincident with the mRNA expression of SGP‐1 it was found that small clusters of gold particles representing anti SGP‐1, presumably membrane bound, were associated with the Golgi apparatus as well as in close proximity to secondary lysosomes. There was, however, no evidence for the secretion of SGP‐1 into the lumen. These results suggest that SGP‐1 is synthesized by the epithelial cells of the male duct system and ferried by small vesicles derived from the Golgi apparatus to secondary lysosomes. Because SGP‐1 has recently been shown to have substantial sequence similarity to prosaposin, it may be speculated that SGP‐1 is instrumental in the degradation of membrane glycolipids present within secondary lysosomes of epithelial cells of the extratesticular duct system.
Blind‐ending tubules and branching patterns of the rat ductuli efferentes
Authors: Guttroff Robert F. , Cooke Paul S. , Hess Rex A.
Published: February 2005

The ductuli efferentes of Sprague‐Dawley rats were studied by microdissection and microscopic evaluation to document the presence of blindending tubules (ductuli aberrantes) and to describe morphological and ultrastructural differences between normally open ductules and blind‐ending tubules. The branching patterns of the ductuli efferentes varied considerably between animals. A majority of the animals studied had either six or seven ductuli connected to the rete testis, with some animals having as few as four or as many as eight. Pairs of ductules began merging in the conus vasculosa, ultimately forming a single terminal duct within the capsule of the initial segment epididymidis. In a majority of animals, the junctions were unequally matched and located at various positions within the conus. Blind‐ending tubules, found in 60% of the animals, were surrounded by thick connective tissue, and had a smaller diameter (78.7 ± 1.4 μm) than normal ductules in the conus vasculosa (119.5 ± 2.1 μm) or the terminus (102.2 ± 1.5 μm). The lumina of blind‐ending tubules were contracted and did not contain sperm. Nonciliated cells in the epithelium of blind‐ending tubules contained fewer PAS‐positive granules and electron‐dense bodies (lysosomes) than nonciliated cells in normal ductules. Consideration of these characteristics will prevent blind‐ending tubules from being mistaken for pathological changes in efferent ductules.
Early development of the human area postrema and subfornical organ
Authors: Castañeyra‐Perdomo A. , Meyer G. , Heylings D. J.
Published: February 2005

The first appearance and early development of two circumventricular organs, the area postrema (AP) and the subfornical organ (SFO), were investigated in human embryos and fetuses from the 4th to the 40th gestational weeks (GW). The AP appears very early in development, during the GW 10; its high vascularization can be seen from GW14, and differentiated neurons are observed from GW 16. The SFO is characterized by a late onset of development. It can first be distinguished at GW 17, but it does not attain cytological differentiation until the last weeks of gestation. It is suggested that the AP has important functions during fetal life, which are related to normal fetal weight and growth; in contrast the SFO, which is connected with drinking behavior and salt/water balance, seems to play a less essential role in early fetal life.
Histochemical study of the heart of the axolotl (Ambystoma mexicanum)
Authors: Melinek Rosemary , Mirolli Maurizio
Published: February 2005

We have investigated the presence of cells containing monoamines, substance P, and neuron‐specific enolase (NSE) in the heart and in the pericardial wall of a urodele amphibian, the axolotl. Fibers containing substance P‐like immunoreactivity were present in the heart but not in the pericardial wall. Also present in the heart were small branched cells, which stained metachromatically with toluidine blue. Similar cells were found in the peritoneum and were tentatively identified as mast cells. NSE‐immunoreactive fibers were found both in the heart and in the pericardial wall. Small intensely fluorescent (SIF) cells of the pericardial wall contained a high concentration of norepinephrine but no other monoamines, substance P, or NSE. Comparison with data available for the mudpuppy, Necturus maculosus, a closely related amphibian species, suggests that the innervation of the heart in the axolotl is substantially different. © 1992 Wiley‐Liss, Inc.
Localization of actin, α‐actinin, and tropomyosin in bovine spermatozoa and epididymal epithelium
Authors: Yagi Ahmed , Paranko Jorma
Published: February 2005

Actin, α‐actinin, and tropomyosin were localized in the testicular, epididymal, and ejaculated spermatozoa and in the epithelium of the bovine epididymis by means of specific antibodies using an indirect immunofluorescence technique. Immunocytochemical results were confirmed by the western blot analysis. Independent of the method of fixation, washing, or sonication, actin, α‐actinin, and tropomyosin were all consistently localized in the neck of the spermatozoa. Actin and tropomyosin present in the postacrosomal area could be removed by sonication, whereas α‐actinin in the basal plate appeared to be resistant to the treatment. In the unwashed spermatozoa α‐actinin‐specific immunofluorescence was seen over the acrosomal area, whereas in the washed sperm it appeared as a narrow cap at the margin of the head. In the latter location, its distribution was similar to that of tropomyosin. In the majority of preparations, tropomyosin could be localized in the principal piece of the tail. Even though some actin‐specific immunofluorescence could be identified in the principal piece of the tail of the testicular and epididymal spermatozoa, a strong immunoreaction appeared only in the ejaculated spermatozoa. In the principal cells of the epididymal epithelium, specific fluorescence for actin, α‐actinin, and tropomyosin occurred in the apical junctional complex. Basal bodies of the solitary cilia of the epididymal epithelium were labelled with antitropomyosin and anti‐α‐actinin antibodies. Besides offering new information about the cytoskeletal composition of the mammalian sperm, the present results support the hypothesized homology between the connecting piece of the sperm neck and the basal body of the cilia. © 1992 Wiley‐Liss, Inc.
Immunohistological analysis in the distribution of cells in the fetal porcine adenohypophysis
Authors: Sasaki Fumihiko , Ichikawa Yuji , Yamauchi Shoji
Published: February 2005

Adenohypophyses of porcine fetuses from 25 to 110 days of gestation were studied by immunohistochemical staining to ascertain the ontogeny of specific cell types and their spatial distribution in the pars distalis. No hormonecontaining cells were found before 30 days of gestation. ACTH cells were observed first at 40 days, while GH and LH cells appeared first at 60 days. PRL cells were initially detected at 105 days. ACTH immunoreactive cells were also observed in the pars intermedia at 40 days.

Blood capillaries were interposed between cell cords of the pars distalis after 40 days of gestation.

ACTH cells were evenly distribution in all areas of the pars distalis except the rostal area (sex zone). GH cells were densely distributed in lateral wings of the pars distalis and immediately anterior to Rathke's lumen. PRL cells resembled GH cells in their distribution pattern, but PRL cells were fewer in number. LH cells were scattered in the sex zone of the pars distalis from 60 to 80 days of gestation. After 90 days, they became scattered throughout the pars distalis but were more numerous in the sex zone than in other areas.

The inductive elements of adenohypophysial cells from Rathke's pouch epithelia are discussed. We hypothesize that cell cords of specific areas facing Rathke's lumen may differentiate into specific cell types of the pars distalis during fetal life. © 1992 Wiley‐Liss, Inc.
Cell kinetics of lamina propria fibroblasts in normal adult hamster bronchus
Authors: Zajicek G. , Breuer R.
Published: February 2005

Forty‐nine 12‐week‐old male Syrian golden hamsters (Mesocricetus auratus), weighing 108 to 128 g, were injected i. p. with [3H]‐thymidine (3HTdR 2 μCi/g body wt). Animals were divided into 7 weight‐matched groups and were killed at 1 hour (day zero) and 1, 2, 3, 4, 7, and 14 days after thymidine injection. Lungs were fixed by vascular perfusion of 4% formalin/1% glutaraldehyde in 0.2 M cacodylate buffer at pH 7.4, cut at 2 μm, dipped in Kodak NTB3 or NTB2 nuclear emulsion, exposed for 2 weeks, developed and stained. In each airway cross‐section, total epithelial and fibroblast counts and labeled cell count were estimated. A cell was considered labeled when 3 or more silver grains appeared on its nucleus. The background grain count was less than 1 grain per nucleus.

Mean epithelial and fibroblast cell density in a 100 μm segment were respectively 14.8 ± 0.1 and 6.6 ± 0.1 cells (the second number is one standard error of the mean). One hour after labeling, their respective labeling indices (L. I.) were 0.13 ± 0.02 and 1.24 ± 0.1. On day 1, their L. I. doubled and then returned to the initial value. One hour after labeling, epithelial and fibroblast mean grain counts did not differ significantly. They were respectively 20.6 + 1, and 15.8 ± 2. Because grain count intensity is closely related to DNA synthetic time, it seems plausible that epithelial and fibroblast synthetic times do not differ much. Cell turnover and cell cycle times were estimated from grain count dilution curves. The respective loggrain dilution slopes, ‐0.025 ± 0.005 and ‐0.044 ± 0.014 do not differ significatly when tested by t‐test. It is concluded, therefore, that both cell types turn over at the same rate with an estimated cell cycle time of 20 days. © 1992 Wiley‐Liss, Inc.
Immunolocalization of enamel proteins during amelogenesis in the cat
Authors: Nanci A. , McKee M. D. , Smith C. E.
Published: February 2005

Amelogenesis in the cat has been suggested to closely resemble enamel formation in human teeth. In order to further characterize the sequence of events leading to enamel formation in the cat, the expression and distribution of enamel proteins throughout amelogenisis were examined by postembedding immunocytochemistry using an antibody to mouse amelogenins and the high resolution protein A‐gold technique. Enamel proteins were first immunodetected in ameloblasts and in the extracellular matrix during the presecretory stage. Secretory stage ameloblasts showed the most intense cellular reactivity. In these cells, protein synthetic organelles, secretory granules, and large lysosome‐like structures were all intensely labeled. Extracellulary, numerous gold particles were observed over enamel and over patches of material found at the baso‐lateral surfaces of these ameloblasts. During the early maturation stage, the protein synthetic organelles and secretory granules of ameloblasts still showed some immunoreactivity, although the most conspicuous labeling at this later stage was found over enamel and over material present amoung the extensive apical membrane infoldings of ruffle‐ended ameloblasts. Qualitative analysis of lysosome‐like elements in ameloblasts suggested that their frequency and immunoreactivity in the maturation stage were relatively lower than in the secretory stage, where some groups of cells often showed numerous large labeled structures. The enamel matrix was intensely labeled at all stages; however, cervical‐occlusal and surface‐depth gradients were readily apparent by conventional staining and by quantitative analysis of immunolabeling in the late secretory and early maturation stages. These data suggest that the cellular and extracellular distribution of enamel proteins in the cat is generally similar to that reported in other species, although some particularities were observed, perhaps reflecting variation in the timing of developmental parameters. © 1992 Wiley‐Liss, Inc.
Development of cartilage and bone tissues of the anterior part of the mandible in cichlid fish: A light and TEM study
Authors: Huysseune Ann , Sire Jean‐Yves
Published: February 2005

The present paper presents ultrastructural details of chondrogenesis of Meckel's cartilage and of ossification of its associated peri‐ and parachondral bones in a teleost fish, the cichlid Hemichromis bimaculatus. We have distinguished four stages during chondrogenesis, each of which is characterized by specific cellular and matrix features: blastema, primordium, differentiated cartilage and cartilage surrounded by perichondral bone. The blastema is characterized by prechondroblasts and the lack of cartilage matrix; the primordium by chondroblasts and the onset of secretion of matrix of fibrillar and granular nature; differentiated cartilage is characterized by chondrocytes and larger amounts of typical hyaline cartilage matrix. Once perichondral bone is laid down, the chondrocytes show degenerative features but not true hypertrophy. Differentiation of the cartilage cells is attended with cytoplasmic changes indicative of an increasing secretory activity. There is a regional calcification of the cartilage matrix by fusion of calcospherites. Chondrogenesis of the symphyseal area is continuous with that of the rami but starts slightly later. Formation of perichondral bone at the cartilage surface is attended with the deposition of a transitional zone apparently containing a mixture of the two matrices. The role of the perichondral cells is discussed and it is proposed that they may contribute to the formation of the two matrices. The transitional zone may then result either from a diffusion process or from the simultaneous deposition of elements of the two matrices. Growth of the cartilage is argued to be largely the result of matrix secretion, except in the symphyseal area where appositional growth probably occurs until the region is completely covered by perichondral bone. This paper provides a basis for further studies on the developmental interactions between cartilage, bone and teeth during mandibular development in cichlids. © 1992 Wiley‐Liss, Inc.
Development of the human sphenomandibular ligament
Authors: Vazquez J. F. Rodriguez , Velasco J. R. Merida , Collado J. Jimenez
Published: February 2005

The development and arrangement of the sphenomandibular ligament of 60 human embryos and fetuses were studied. Meckel's cartilage appeared as a single, continuous fibrous structure lying between the mandibular lingula and the malleus of the middle ear in fetuses of 210 mm crown‐rump length (22 weeks of age) and over. This structure constitutes the malleolomandibular ligament, and two clearly differentiated portions bound by the tympanosquamosal fissure could be seen: a juxtaarticular portion, inserted on the posterior edge of the interpterygoid aponeurosis, and a tympanic portion, onto which the disc of the temporomandibular joint inserted. Some of the authors consider that if tension is applied to the sphenomandibular ligament this may injure the middle ear. The anatomical arrangement of the sphenomandibular ligament could explain these injuries. © 1992 Wiley‐Liss, Inc.
Cytochemical localization of dipeptidyl peptidase II activity in rat incisor tooth ameloblasts
Authors: Smid J. R. , Monsour P. A. , Rousseau E. M. , Young W. G.
Published: February 2005

Dipeptidyl peptidase II (DPP II), E.C. 3.4.14.2, a serine class endopeptidase, is widely used as a lysosomal marker in cytochemical studies. To date most ultrastructural studies of ameloblasts use the presence of acid phosphatase activity to identify cellular organelles to be lysosomal. Using decalcified rat mandibles, with kidney tissue as a positive control, DPP II activity, was assessed with specific substrate Lysyl‐alanine‐4‐methoxy‐2‐naphthylamide in ameloblasts at an ultrastructural level. Reaction product (RP) indicative of DPP II activity was observed only within lysosome‐like organelles. These RP‐labelled organelles were only localized in the supra‐ or para‐nuclear regions of the ameloblasts, which corresponds with previous studies using acid phosphatase cytochemistry. However, in contrast with these studies, RP was not detected in the distal region of the ameloblasts, viz., in the Tomes' processes of the secretory ameloblasts or near the ruffled border in the maturation ameloblasts. The transitional ameloblasts were notable for the intensity of staining of their RP‐labelled organelles. We propose that DPP II may have a role in programmed cell death which is thought to occur in this transition zone.

Biochemical analysis of rat incisor enamel organ homogenates, indicated tissue fixation resulted in an 82% reduction in DPP II activity, although the specific activity of DPP II was not affected. © 1992 Wiley‐Liss, Inc.
Demonstration of amelogenin in the enamel‐free cusps of rat molar tooth germs: Immunofluorescent and immunoelectron microscopic studies
Authors: Inai Tetsuichiro , Nagata Kengo , Kukita Toshio , Kurisu Kojiro
Published: February 2005

The enamel‐free cusps of 1–4‐day‐old rat mandibular first molars were investigated using the monoclonal antibody En3 against rat amelogenin at light and electron microscopic levels in order to clarify whether the enamel‐free cusp is virtually devoid of enamel.

At 1 day after birth, there were presecretory ameloblast‐like cells (PALCs), which were short and were not polarized, at the cusp tips. They were close to the outer enamel epithelium. Hematoxylin positive enamel matrix was not distinctly observed in the enamel‐free cusp by light microscopy, but almost continuous immunofluorescence for amelogenin was detected at the interface between PALCs and dentin. The penetration of immunopositive material toward the dental pulp was also observed in the enamel‐free cusp.

At 4 day after birth, both in the frontal section and in the horizontal section, almost continuous immunofluorescence was recognized at the interface between PALCs and dentin in the enamel‐free cusp. The penetration of amelogenin toward the dental pulp was not seen in the enamel‐free cusp. By immunoelectron microscopy, immunolabelling was recognized in the Golgi apparatus of PALCs, in a layer of amorphous material at the interface between PALCs and dentin, and in stippled material‐like substance in the intercellular space between PALCs. Although no basement membrane was observed beneath PALCs, they did not have Tomes' processes.

These investigations suggest that PALCs in the enamel‐free cusp differentiate into the secretory cells and that they can synthesize and secrete the amorphous material containing amelogenin at the interface between PALCs and dentin. The penetration of amelogenin toward the dental pulp might play a role in the interaction between PALCs and odontoblasts in the enamel‐free cusp and/or the initiation of mineralization of predentin. © 1992 Wiley‐Liss, Inc.
Selective lectin‐binding sites of primordial germ cells in chick and quail embryos
Authors: Yoshinaga Kazuya , Fujimoto Toyoaki , Nakamura Masao , Terakura Hirotsugu
Published: February 2005

To ascertain the histochemical characteristics of surface carbohydrates on avian primordial germ cells (PGC), we examined the distribution of binding sites for several biotinylated lectins in chick and quail embryos. Some binding sites were detected almost selectively with PGC but not with other embryonic sites. Of these, lectin from Sojanum tuberosum (STA) reacted with PGC in both avian species, whereas lectin from Wistaria floribunda (WFA) and Griffonia simplicifolia II (GS‐II) reacted in the quail and the chick, respectively. The binding site for STA was found at the cell surface and cytoplasm of the PGC from their initial appearance in the germinal crescent through migration to sexually indifferent gonads, whereas the WFA reaction was seen at stages before and during migration. These reactivities showed most intensely on the surface of PGC at the peak of their migration. In contrast, GS‐II binding site was restricted to the cytoplasm, and its distribution was similar to that of the periodic acid‐Schiff (PAS)‐positive glycogen granules in chick PGC. These results suggest that some selective binding sites on the PGC surface play a significant role in their migration and show that lectins STA, WFA, and GS‐II can be used as probes for identification of the avian PGC. © 1992 Wiley‐Liss, Inc.
Plastic embedding procedure for 15 μm sections of large undecalcified tissue blocks
Authors: Lataster L. M. A. , Van Mameren H. , Terwindt E.
Published: February 2005

A method is described that produces sections (15 μm) of large specimens (with dimensions up to 140 × 100 × 200 mm). They are suitable for comparison to CT images of that specimen and can be used as a basis for three dimensional reconstructions.

Frozen unfixed parts of the human body are embedded in polyurethane and scanned with CT. Undecalcified slices, 6 mm thick, of these specimens are cut with a bandsaw. These slices are successfully embedded in polyester resin by means of fixation, dehydration, and subsequent impregnation with this resin. Sections of 15 μm are obtained by cutting the trimmed and sandpapered polyester blocks with an LKB multirange microtome. They are collected on adhesive tape and stained according to Weigert‐Azan, sealed between adhesive acetate sheets and photographed on colour slide film. As an example photographs of sections of the human elbow and lumbar spine region are presented. © 1992 Wiley‐Liss, Inc.
A comparative study on the effects of tumor necrosis factor‐α (TNF‐α), human angiogenic factor (h‐AF) and basic fibroblast growth factor (bFGF) on the chorioallantoic membrane of the chick embryo
Authors: Olivo Michael , Bhardwaj Ranjit , Schulze‐Osthoff Klaus , Sorg Clemens , Jacob Heinz Jürgen , Flamme Ingo
Published: February 2005

The chorioallantoic membrane (CAM) assay is a widely used bioassay for testing angiogenic activities. In the present study we compared the gross and micromorphological effects of three angiogenic factors applied in Elvax™ carriers on the CAM: Tumor necrosis factor‐α (TNF‐α), human angiogenic factor (h‐AF), and basic fibroblast growth factor (bFGF). Our question was whether the CAM responds to these factors which have very different actions with a stereotype or with a factor specific reaction. By microangiography and light microscopy, all positive reactions appeared as a spoke‐wheel vascular pattern with a bundle of small capillary blood vessels in the center. These vessels were predominatly of a distended type in h‐AF and TNF experiments, while narrower capillary vessels followed bFGF application. Chorioallantoic ectoderm and endoderm were thickened by cell accumulation and the mesenchymal stroma of the CAM was edematous and infiltrated with leucocytes in all three reactions. Additionally, bFGF experiments showed areas of densely arranged fibroblasts. Observations in vivo showed chorioallantoic tissue movements as a possible mechanism for the spokewheel vascular pattern. As compared with our results from studies of cytokinetics with bromodeoxyuridine, these current findings indicate that chemotaxis is responsible for the chorioallantoic angiogenic reaction rather than cellular proliferation. © 1992 Wiley‐Liss, Inc.
Differences in fiber number and fiber type proportion within fascicles. A quantitative morphological study of whole vastus lateralis muscle from childhood to old age
Authors: Sjöström Michael , Lexell Jan , Downham David Y.
Published: February 2005

Data are presented on the number of fibers and the proportion of different fiber types within fascicles of whole vastus lateralis muscles from 5 male children, 5 to 15 years of age, and compared with results from 25 male adults, middle aged and old individuals. The results verify a difference in the proportion of fibers with different properties within a fascicle. The proportion of type 2 (fast twitch) fibers on the border of fascicles is larger than the proportion internally: the children have (P<0.01) greater difference than the adults and the middle aged, whereas the old have (P<0.001) less difference than the other age groups. The mean number of fibers per fascicle increases (P<0.05) from childhood to adult age, and thereafter reduces (P<0.01). The results imply that fascicles continuously rearrange during the normal growth and development and the normal aging process. It is argued that the causes of the difference in fiber type proportions within fascicles are local factors in the muscle, secondary to the overall age related functional demands put on the fiber population.© Willey‐Liss, Inc.
Localization and activity of Na+, K+ ‐ATPase in the ductuli efferentes of the rat
Authors: Ilio Kenneth Y. , Hess Rex A.
Published: February 2005

The Na+, K+ ‐ATPase enzyme through its p‐nitrophenyl phosphatase activity was localized in the ductuli efferentes of rats. Enzymatic activity was demonstrated along the cytoplasmic side of the plasmalemma of the ductular epithelial cells. The most intense deposition of reaction products was found on the plasmalemma delimiting the lower lateral and basal regions of the cells. The plasma membranes forming the microvilli, apical junctional complexes were devoid of reaction product while the midlateral membranes showed a weak reaction. The enzyme reaction was potassium‐dependent and was abolished by addition of 10 mM ouabain to the incubation media. Enzyme activity decreased significantly from proximal to distal regions of the ductules (8,101.47 ± 274.53, 6,658.95 ± 269.53 and 4,668.10 ± 575.41 pmoles p‐nitrophenol/mm/h, respectively in initial, conus vasculosus and terminal zones). A unified model for water absorption is proposed in the efferent ductules based upon this data and that of others.© Willey‐Liss, Inc.
Morphology of the bile ducts of the brook lamprey, Lampetra lamottenii (Le Sueur) before and during infection with the nematode, Truttaedacnitis stelmioides (Vessichelli, 1910) (Nematoda: Cucullanidae)
Authors: Eng F. , Youson J. H.
Published: February 2005

Routine light microscopy and transmission and scanning electron microscopy were used to describe and compare the biliary tree of larval Lampetra lamottenii before and during infestation of the bile ducts with the nematode, Truttaedacnitis stelmioides. The most prominent changes to the biliary tree following infection by the parasite are the dilation of the bile ducts, alterations to their epithelial cells, and an increase in periductal fibrous tissue. In recently infected animals, the simple epithelium of dilated bile ducts often contains many mitotic figures. In long‐term infestations, the epithelium is stratified or pseudostratified. Changes to the fine structure of the biliary epithelial cells include increase and/or dilation of the RER and SER, and increases in microfilaments, intermediate filaments, and microtubules. The abundance of dense bodies may reflect enhance reabsorption of biliary constituents, and their accumulation may ultimately result in cytolysis. There are increased mucous granules in the apical cytoplasm of biliary epithelial cells and an abundance of mucinous material within the bile duct lumen, and the basal lamina appears thickened. The changes to the liver of L. lamottenii following infection are discussed and compared to those reported in small mammals following bileduct ligation, in patients with extrahepatic biliary obstruction, and in parasitic infection of the biliary tree.© Willey‐Liss, Inc.
Structure and dynamics of adrenal mitochondria following stimulation with corticotropin releasing hormone
Authors: Bornstein Stefan R. , Ehrhart‐Bornstein M. , Güse‐Behling H. , Scherbaum W. A.
Published: February 2005

The mitochondria of rat adrenals were investigated qualitatively and quantitatively in different functional states of the adrenal cortex. Following stimulation of the animals with corticotropin releasing hormone (CRH), the corticosterone serum levels reached a maximum 1 hour after stimulation with CRH. The amount of inner mitochondrial membrane within the zona fasciculata increased showing a biphasic time course, with a first maximum 2 hours and a second maximum 8 hours after stimulation. In contrast, a significant rise of mitochondrial volume occurred only 24 hours after CRH stimulation. Therefore, the dense vesicularization of mitochondrial cristae may constitute an early process to enhance the steroidogenic capacity of these cells. Within cells of the transition zone between zona glomerulosa and zona fasciculata, we could depict a special type of mitochondria with characteristic crescent‐like cristae only seen after stimulation with CRH. This type of mitochondria may represent an intermediate form between mitochondria of zona glomerulosa and zona fasciculata underlining the impressive transformational capacity of adrenocortical mitochondria. After hypophysectomy, zona fasciculata cells contained mitochondria with tubular inner membranes, representing a hypofunctional state. In contrast, the hypofunctional state after hypophysectomy and the hyperfunctional state after stimulation of the adrenal cortex via CRH injection did not appear to correlate with the morphology of mitochondria from the zona reticularis and adrenal medulla.© Willey‐Liss, Inc.
Morphology of the kidney of the platypus (Ornithorhynchus anatinus: Monotremata)
Authors: Tsujii Tadashi , Inoue Satoko , Takamiya Haruo , Liszczynsky Helen R. , Naora Hiroto , Seno Satimaru
Published: February 2005

The platypus kidney shows morphological similarities to those of other mammals. Macroscopically, the cortex is easily distinguishable from the fairly wide medulla. Within the medulla, no clear border is observed between the inner and outer zones. Light and transmission electron microscopically, the glomeruli show quite similar architecture to those of other mammals; however, the glomerular lobulation is very clear. The glomerular tufts are rather simple, but capillary lumen varies widely in size, which is one of the unique features of the platypus kidney. The urinary tubule is generally similar to that of human and other mammals in shape and segmentation; however, the staining specificities of histochemical reactions and the shape of epithelial cells of the Henle's loop differ from those ofother mammals. The most conspicuous features are: 1) although no protein casts are found in the tubular lumina, epithelial cells of the proximal convoluted tubule (PCT) have numerous electron‐dense vesicles as in human nephrotic kidneys; and 2) the platypus Henle's loop consists of the thick epithelial cells similar to the mammalian type nephron of birds. As compared to those of other mammals such as humans and rats, our observations suggest that the platypus kidney is less developed, in terms of evolution.© Willey‐Liss, Inc.
Ultrastructural alteration of cartilaginous fibril arrangement in the rat mandibular condyle as revealed by high‐resolution scanning electron microscopy
Authors: Segawa Kazuyuki , Takiguchi Reiji
Published: February 2005

Three‐dimensional alteration of fibrillar matrix in the rat mandibular condylar cartilage was investigated with a high‐resolution scanning electron microscope (SEM) and it was determined whether alterations correlate with developing occlusion and advancing age. Two important SEM techniques of DMSO freeze‐cracking and treatment with trypsin and hyaluronidase were employed to remove interfibrillar proteoglycans and disclose fibril arrangement. Our SEM investigation demonstrated that collagen fibrils in the fibrous zone covering hyaline‐cartilaginous area in the condyle are thicker (50 to 80 nm in diameter) than the fibrils (30 to 50 nm in diameter) that predominantly constituted an interterritorial fibrillar matrix (IFM) in the area. While the thick fibrils had a distinct striation of about 55 nm periodicity, the thin fibrils had no distinguishable striation. The thick fibrils having a periodic striation of about 60 nm was found along with the thin fibrils, also in the IFM in the aged rats and in the deep IFM, but were considerably less than the thin fibrils. The fibrils in the fibrous zone and IFM were disorderly arranged at 19‐day‐insemination age. In 1‐week‐old rats whose incisors erupted, the fibrils constituting the fibrous zone altered from disordered to ordered arragement. The IFM in these rats took the form of a network. Incorporation of small fibrillar bundles into the fibrillar network was seen in 2‐week‐old rats whose upper and lower first molars erupted. In 8‐week‐old rats whose molars had erupted completely, the IFM completely occupied by regularly oriented fibrils appeared additionally. The structural alteration that occurred in both individual fibrils and fibril arrangement probably correlates with increasing stress due to developing occlusion and aging of the condylar cartilage.© Willey‐Liss, Inc.