bluuebunny/crossref_metadata_2025 huggingface dataset:
Homogeneity in the distribution of matrix components in the hamster zona pellucida as revealed by backscattered electron imaging fracture‐label
Authors: Kan Frederick W. K. , Zalzal Sylvia , Roux Emmanuelle , Nanci Antonio
Published: February 2005

Background: Backscattered electron imaging fracture‐label (BEI‐FL), an adaptation of the fracture‐label method for scanning electron microscopy, offers the advantage of providing information about the distribution of antigenic and receptor sites with respect to the three‐dimensional organization of tissues and cells over relatively large surfaces. Recently, using post‐embedding cytochemistry on thin‐sections of Lowicryl‐embedded oocytes, a homogenous distribution of glycoproteins in the zona pellucida (ZP) was demonstrated (Kan et al., 1989. Biol. Reprod., 40:585–598, Anat. Rec., 226:37–47; Roux and Kan, 1991. Anat. Rec., 230:347–360). However, it can be argued that the chemical nature of resins and the physical conditions of tissue processing required for post‐embedding cytochemistry may introduce changes in the tissue components and result in altered distribution of components. On the other hand, freeze‐fracture exposes constituents in a minimally denaturing manner and, since no embedding media are used, binding sites are sterically available to the probe. We have, therefore, applied BEI‐FL to examine the distribution of matrix glycoproteins in the ZP of hamster oocytes.

Methods: Ovaries and cumulus masses obtained from superovulated female golden hamsters were fixed by immersion in 2.5% glutaraldehyde and processed for fracture‐label. Tissues were labeled, respectively, with Wheat germ agglutinin (WGA) followed by ovomucoid‐colloidal gold, Ricinus communis agglutinin I (RCA I)‐colloidal gold or a monoclonal antibody against Hamster Oviductin‐1 followed by protein A‐gold, and then examined in the scanning electron microscope.

Results: Backscattered electron imaging revealed a homogenous distribution of WGA and RCA I binding sites throughout the cross‐fractured matrix of the ZP of cvrian and postovulatory oocytes. Hamster Oviductin‐1, an oviductal glycoprotein which is transferred to the ZP of oocytes during oviductal transit, was also found to be uniformly distributed throughout the ZP of postovulatory oocytes.

Conclusions: Our results indicate that BEI‐FL can be advantageously used to examine extracellular matrices and are consistent with the concept that glycoproteins are uniformly distributed throughout the ZP of the hamster oocyte. © 1994 Wiley‐Liss, Inc.
Distribution of prothymosin alpha in rat and human adrenal cortex
Authors: Garcia‐Caballero T. , Dominguez F. , Roson E. , Gallego R. , Zalvide J. , Forteza J. , Beiras A.
Published: February 2005

Background: Prothymosin alpha (ProT) is a polypeptide widely distributed in the organism and expressed by cell types with a high proliferative capacity. The aim of the current work was to investigate if ProT was localized in the progenitor compartment of the adrenal cortex which, following the cell migration theory, corresponds to the zona glomerulosa.

Methods: We studied by immunohistochemical and in situ hybridization methods the distribution of ProT in rat and human adrenal cortex. Immunohistochemical techniques for the study of the proliferating cell nuclear antigen (PCNA) and incorporation of 5‐bromo‐2′‐deoxyuridin during DNA synthesis were also done. Immunoelectron microscopic procedures were performed to determine the exact subcellular localization of ProT.

Results: ProT was found in the zona glomerulosa cells, but not in the cells of the remaining cortical layers (zonae fasciculata and reticularis). Glomerulosa cells showed immunostaining for ProT only in the nuclei, excluding the nucleoli. Variability in immunostaining intensity was found between different glomerulosa cells. In situ hybridization of ProT mRNA confirmed that ProT synthesis in adrenal cortex occurs only in the zona glomerulosa. The results obtained for proliferating cell nuclear antigen and incorporation of 5‐bromo‐2′‐deoxyuridin confirmed that adrenocortical proliferation occurs in the zona glomerculosa. Ultrastructural immunocytochemistry showed labelling for ProT over the euchromatin, but not on the heterochromatin aggregations nor the nucleoli.

Conclusions: The results presented here: (1) support the migration theory for the adrenocortical cell renewal, (2) demonstrate that ProT is present in the nuclei of proliferating cells (being associated with euchromatin), and (3) suggest that the study of ProT expression would be useful in distinguishing cycling from resting cells. © 1994 Wiley‐Liss, Inc.
Development of the inlet portion of the right ventricle in the embryonic rat heart: The basis for tricuspid valve development
Authors: Wenink Arnold C. G. , Wisse Bert J. , Groenendijk Pieter M.
Published: February 2005

Background: Before septation the entire atrioventricular canal is connected with the ventricular inlet segment (primitive left ventricle), wheres the mature heart exhibits an exclusive connection of the right atrium to the right ventricule. The process which is responsible for this change is controversial.

Methods: Graphic reconstructions of serially sectioned embryonic rat hearts as well as scanning electron micrographs of similar specimens were made.

Results: The first indication of a right atrioventricular connection was seen as a groove in the atrioventricular junctional myocardium to the right of the inferior endocardial cushion. This groove expanded to form the right ventricular inlet portion. The right, inferior, and superior walls of this newly formed cavity were formed from junctional myocardium, which demarcated it from the trabeculated right ventricular portion in all developmental stages. The left wall equally developed from this junctional myocardium and formed the ventricular inlet septum. The junctional myocardium between right ventricular inlet and trabeculated portions was seen to develop into the tricuspid valve and its tension apparatus.

Conclusions: The preseptation embryonic heart has no inlet portion to the right ventricle. This new cavity is created by remodelling of atrioventricular junctional myocardium. This myocardium also provides the material contribution to the tricuspid valve and its tension apparatus. Malformations of the right ventricular inlet portion and of the tricuspid valve are indissolubly linked. © 1994 Wiley‐Liss, Inc.
Restricted endothelial cell expression of gravin in vivo
Authors: Grove Bryon D. , Bowditch Ron , Gordon Tom , Zoppo Gregory Del , Ginsberg Mark H.
Published: February 2005

Background: Gravin, a novel, high molecular weight, intra‐cellular protein, is expressed in endothelial cells and several other adherent cell types in vitro. To gain insights into its function, we examined the distribution of gravin in tissues.

Methods: Affinity‐purified polyclonal and monoclonal antibodies were raised against a bacterial fusion protein corresponding to the carboxyl terminus of gravin and against affinity‐isolated gravin. The specificity of the antibodies was characterized by immunoblotting bacterial, cell, and tissue extracts. The characterized antibodies were used to localize gravin in baboon tissue sections by immunocytochemistry and immunofluorescence microscopy.

Results: The antibodies specifically immunoblotted the fusion protein and recognized either a band at 250 kDa or a doublet at 300 kDa on immunoblots of MG63 cells, HEL cells stimulated with phorbol ester, and several baboon tissues. In tissue sections, cell types that express gravin included fibroblasts, components of the peripheral and central nervous system, the adrenal medulla, the somatic layer of Bowman's capsule, cells associated with the glomerulus, and smooth muscle of certain organs. In contrast, most epithelia and all endothelia, with the exception of endothelia of the hepatic sinusoids and intestinal lacteals, lacked gravin. Levels of gravin mRNA expression in stimulated HEL cells increased dramatically when cells were stimulated in the presence of cycloheximide, suggesting that gravin expression may be partly regulated by protein‐dependent mRNA catabolism.

Conclusions: These data indicate that gravin expression is regulated in endothelial cells, possibly through protein‐dependent mRNA catabolism. The strong expression of gravin in fibroblasts, neurons, and cells derived from neural crest in vivo and in adherent cells in vitro further suggests that this protein may play role in the modulation of cell motility and adhesion. © 1994 Wiley‐Liss, Inc.
Changes occurring with increasing age in the rat lung: Morphometrical study
Authors: De Dios Escolar Juan , Gallego BegoñA , Tejero Carlos , Escolar María Asunción
Published: February 2005

Background: It was hypothesized that the evolution towards the senile lung is progressive, being initiated in the adult stage; and for this reason changes similar to those described in the senile lung can be detected in the lungs of middle‐aged rats. To test the hypothesis, the following design was used. The lungs of two groups of rats, adult (mean age of 16 weeks) and middle‐aged (mean age of 56 weeks) were morphometrically compared.

Methods: Thirty‐one Wistar rats were used for the study; their lungs were processed histologically. The microscopic fields were analysed in a computer, and 20 variables were quantified. These were grouped into (a) variables which describe the shape and size of the distal airspace, (b) variables which describe the distal lung tissue, and (c) variables which describe elastic fibers. The results were statistically compared: correlation tests were carried out, and the specificity, sensitivity, and misclassification indices were calculated.

Results: All the results of the variables which define the size of the air‐spaces were found to be significantly higher (P<0.0001) in the middle‐aged animals; the results obtained when the lung tissue was quantified directly from the histological section suggested a loss of tissue in the middle‐aged animals. However, when these data were converted into absolute values, no loss was indicated in the total lung tissue. The values of the variables which describe the elastic fiber were found to have increased significantly (P<0.0001) in the middle‐aged animals. The misclassification index was found to be lower than 10% in six variables and between 10% and 20% in four.

Conclusion: The low misclassification indices found lead us to consider that our morphometric method is ideal for distringuishing the lungs of the two groups of animals used. The results of the quantification of the variables show that the middle‐aged animals exhibit simple enlargement of the distal airspaces, without tissue loss, which coincides with the current definition of the senile lung. © 1994 Wiley‐Liss, Inc.
Electron microscopic and histochemical studies of the mononuclear odontoclast of the human
Authors: Domon Takanori , Sugaya Kazuyuki , Yawaka Yasutaka , Osanai Masakazu , Hanaizumi Yoshinori , Takahashi Shigeru , Wakita Minoru
Published: February 2005

Background: Osteoclasts and odontoclasts are multinucleated giant cells which resorb hard tissue by the ruffled borders. Recently, the authors reported the presence of a mononuclear osteoclast with a ruffled border in vitro. However, its presence in vivo has not been shown. To demonstrate the presence of a mononuclear odontoclast in humans, the present study used human deciduous teeth.

Methods: After fixation and declacification, tartrate‐resistant acid phosphatase (TRACPase) activity was detected with the azo dye method, and then TRACPase‐positive cells were observed on resorbing areas of teeth. TRACPase‐positive cells could be distinguished from other cells by light microscopy, and the cells for investigation were serially sectioned by alternating semithin and ultrathin sections to observe their ultrastructure and three‐dimensional organization.

Results: TRACPase activity was detected in both multinucleated odontoclasts and a mononuclear cell from serial sections. By electron microscopy, most of the multinucleated odontoclasts had ruffled borders and clear zones. A mononuclear TRACPase‐positive cell with a ruffled border and clear zone was reconstructed three‐dimensionally by NIKON COSMOZONE 2SA. The reconstruction showed that this cell had one irregularly shaped nucleus and a wide ring‐shaped clear zone and a small ruffled border. Under the ruffled border, this cell formed a small lacuna on the dentin surface. The results suggested that this cell was a mononuclear odontoclast.

Conclusions: The present study concludes that cells with ruffled borders and clear zones observed by transmission electron microscopy can be identified as odontoclasts or osteoclasts irrespective of the number of nuclei. © 1994 Wiley‐Liss, Inc.
Androgenic control of porphyrin in the harderian glands of the male syrian hamster is modulated by the photoperiod, which suggests that the sexual differences in porphyrin concentrations in this gland are important functionally
Authors: Buzzell Gerald R. , Menéndez‐Peláez Armando , Hoffman Roger A. , Rodríguez Carmen , Antolin Isaac
Published: February 2005

Background: The porphyrin concentrations of the Harderian glands of Syrian hamsters show marked sexual differences, with male levels being much lower than those of females. Porphyrinogenesis is inhibited by androgens, so orchidectomy leads to elevated male porphyrin concentrations; however, a number of other procedures (some of which also lower androgen levels) prevent this. We studied the effects of short‐day photoperiods and melatonin on Harderian porphyrin concentrations.

Methods: Intact, castrated, or pinealectomized hamsters of both sexes were exposed to long‐day or short‐day photoperiods. Intact or castrated hamsters were given melatonin injections in the morning or the afternoon, or were given beeswax pellets containing melatonin. After a variable period, Harderian glands were dissected and porphyrins were measured.

Results: Prolonged short‐day exposure (13 weeks) led to increased Harderian porphyrin concentrations and this rise was prevented by pinealectomy. The rise in Harderian porphyrins following short‐day exposure was small, compared with that following castration. Short‐day photoperiods also prevented the rise in porphyrin levels associated with castration and this effect was prevented by removal of the pineal. Melatonin injections, whether given in the morning or in the afternoon, had no effect on Harderian porphyrin concentration of castrated male hamsters. Continuous release melatonin pellets reduced the postcastrational rise in porphyrin levels in one experiment, while having no effect in another. In female hamster, neither short photoperiods nor melatonin pellets influenced Harderian porphyrin concentrations.

Conclusions: These results suggested that a factor from the pineal gland helps maintain the low levels of porphyrin which are characteristic of male Harderian glands, despite the decrease in androgen levels which typically results from exposure to short days. Morning and afternoon injections of melatonin and continuous release melatonin pellets failed to resolve the question of whether this pineal factor is melatonin. Our results demonstrated that low male and high female porphyrin levels are maintained in Syrian hamsters, despite seasonal variations in the hormonal milieu, suggesting that these sexual differences are important for the (still unestablished) function of the Harderian glands in this species. © 1994 Wiley‐Liss, Inc.
Morphometry of the kidney in rat pups from uninephrectomized mothers
Authors: Okada Toshiya , Yamagishi Tatsuro , Morikawa Yoshio
Published: February 2005

Background: The present study was designed to explore whether maternal renal dysfunction affects fetal kidney development and if the effects are lasting during the postnatal development.

Methods: Kidneys of 1‐day‐old and 6‐week‐old pups from mothers which were uninephrectomized on day 5 of gestation were studied.

Results: One day after birth, both the number of immature glomeruli and average volume of mature glomeruli of the neonates from uninephrectomized mothers were significantly larger than those from sham‐operated mothers. Six weeks after birth, no significant differences in parameters of the kidney were observed between the pups from uninephrectomized and those from sham‐operated mothers. Furthermore, blood urea nitrogen (BUN) concentration in adult female rats was determined at various days after uninephrectomy. BUN concentration in uninephrectomized rats was significantly higher than that in sham‐operated ones.

Conclusions: These results suggest that the fetal kidney development is accelerated by the elevated BUN level following maternal uninephrectomy and that the renotropic activity does not last during the postnatal developmental period. © 1994 Wiley‐Liss, Inc.
Expression of epidermal growth factor receptor (EGFr) immunoreactivity in human cutaneous nerves and sensory corpuscles
Authors: Vega J. A. , Vazquez E. , Naves F. J. , Calzada B. , Del Valle M. E. , Represa J. J.
Published: February 2005

Background: The epidermal growth factor receptor (EGFr) binds both epidermal growth factor (EGF) and transforming growth factor α (TGFα), which are currently considered among putative growth factors playing a role in the nervous system. EGFr and their ligands have been localized in the mammalian peripheral nervous system. The present study was undertaken to investigate whether nerves and sensory corpuscles supplying human glabrous skin express EGFr.

Methods: Formaldehyde fixed, paraffin embedded samples of finger‐tip digital skin obtained from adult healthy subjects were processed for indirect PAP immunohistochemistry using a monoclonal antibody against an epitope of the intracellular domain of EGFr. To ascertain the localization of EGFr immunoreactivity, neurofilament proteins (NFP), S100 protein (S100P), and epithelial membrane antigen (EMA) were studied in parallel to label axons, Schwann cells, and perineurial cells, respectively, as well as their corpuscular derivatives.

Results: A variable intensity of EGFr immunostaining was regularly observed in the perineurium and Schwann cells, and occasionally in the axons of nerve bundles. EGFr immunoreactivity was also present in the axon and lamellar cells of Meissner corpuscles, and within the axon, inner‐core, outer‐core, and capsule of Pacinian corpuscles.

Conclusions: Present results demonstrate that human cutaneous nerves and sensory corpuscles express EGFr suggesting a role for peptides able to bind EGFr, i.e., EGF and TGFα, in the human peripheral nervous sensory system. © 1994 Wiley‐Liss, Inc.
Ultrastructure and histochemistry of human anterior lingual salivary glands (glands of blandin and nuhn)
Authors: Tandler Bernard , Pinkstaff Carlin A. , Riva Alessandro
Published: February 2005

Background: Speciamens of human anterior lingual salivary glans obtained by surgery and by dissection of cadavers were studied ultrastructurally and histochemically.

Methods: Specimens were obtained by surgery for ultrastructural study. Other specimens for histochemistry were obtained by dissection of fresh cadavers. Tissues for electron microscopy were fixed and processed by conventional mesns. Formalin‐fixed cadaver specimens were subjected to a battery of tests for glycoconjugates.

Results: The anterior lingual salivary glands are composed predominantly of mucous tubules (which come in two distinct sizes: large and small), seromucous demilunes, and rare seromucous acini. Regardless of tubule size, mucous cells are typically in appearance and, like mucous cells in other human salivary glands, contain filamentous bodies. Histochemically, the larger tubules contain neutral glycoproteins, low concentrations of sialoglycoproteins, and large amounts of sulfated glycoproteins. The small mucous tubules contain neutral glycoproteins, much sialoglycoprotein, and relatively small amounts of sulfated glycoprotein. The seromucous cells, whether demilunar or acinar, are identical. They contain numerous secretory granules, which show a spectrum of internal patterns from one individual to another. These cells have considerable concentrations of neutral‐ and sialoglycoproteins and lower concentrations of sulfated gly‐coproteins. Countrary to previously published reports, we could find no differences in the ratio of mucous to seromucous cells along the anteriorposterior lingual axis: there was no gradient of seromucous cells in our specimens. The ducts in the anterior lingual salivary glands are not precise counterparts of those in the major salivary glands, since the former have no capsules, hence lack lobulation. Without these familiar structural landmarks, the only duct that can be identified with certainty is the intercalated duct, and then only if it is in continuity with or lies close to a secretory endpiece. Such ducts consist of simple cuboidal epithelium of prosaic appearance. The ductular epithelium gradually thickens and gives rise to what appear to be excretory ducts consisting of columnar cells with few mitochondria. Scattered within the walls of the walls of the larger ducts are patches of typical striated ducts wherein the taller cells display basal striations resulting from highly folded basal plasma membranes and numerous, vertically oriented, virgulate mitochondria. In other atypical regions of the excretory duct, basal cells may have a primary cilium that juts into the intercellular space.

Conclusions: There is a high degree of structural variability in human anterior lingual salivary glands. Because of the technical difficulties in collecting pristine saliva from these glands, the precise functions(s) of these organs remains unknown. © 1994 Wiley‐Liss, Inc.
Changes in proteoglycans of ageing and osteoarthritic human articular cartilage: An electron microscopic study with polyethyleneimine
Authors: Sauren Yvonne M. H. F. , Mieremet René H. P. , Lafeber Floris P. J. G. , Huber‐Bruning Olga , Groot Cornelis G. , Scherft Johannes P.
Published: February 2005

Background: Ageing and osteoarthritic (OA) cartilage show characteristic alterations in chondrocyte morphology and in the composition and content of matrix proteoglycans (PGs). Data concerning matrix components are mostly of biochemical nature. Ultrastructural histochemistry is needed to gain more information about distribution of these altered matrix components.

Methods: We used the cationic dye polyethyleneimine (PEI) to visualize at the EM level alterations in the distribution and dimensions of PGs of human healthy young, healthy aged, and OA articular cartilage.

Results: Young cartilage contained PEI‐positive granules in the superficial layer and big winding PEI‐positive structures in the deeper layers. In the healthy aged tissue, PEI‐positive granules were observed throughout the matrix and smaller winding structures were present in the deeper layer. In OA cartilage both types of PEI‐positive structures were absent in the superficial layer. Deeper in the matrix PEI‐positive granules could be demonstrated. Moreover, PEI‐positive angular structures were observed in the deeper zones.

Conclusions: The differences in PEI‐positive structures are a good reflection of the differences in PGs between young, ageing, and OA cartilage as demonstrated in biochemical studies. PEI, used at the EM level, gave more precise information concerning the localized changes in quality, quantity, and location of PGs in articular cartilage during ageing and disease. © 1994 Wiley‐Liss, Inc.
Abandonment of germ cells in the embryonic chick ovary: TEM and SEM studies
Authors: Ukeshima Atsumi
Published: February 2005

Background: Embryonic chick ovary forms medulla and cortex successively in early developmental stages. Unlike the cortex, which is a functioning tissue in the adult, the medulla regresses as development advances. Although germ cells are included in these respective regions, their behavior within these regions is different. This study focuses on the fate of germ cells in the medulla of both ovaries.

Methods: Germ cells found in the medulla of the developing chick ovary from 7 to 19 days of incubation were observed by TEM and SEM.

Results: From 10 days of incubation onward, medullary germ cells in both right and left ovaries were often released into medullary lacunae. During the releasing process, germ cells were covered by thin cytoplasm of epithelial cells of the lacunae. After release, however, they were freed from the thin coat of epithelial cells. Abandoned germ cells were seen in the lacunae as solitary cells or as a mass composed of several cells. In the right ovary, germ cells released into the lacunae were subsequently found at the holes of the ovarian surface, which were continuous with the medullary lacunae. Moreover, germ cell death was often found in late stages in the medullary tissues of both right and left ovaries.

Conclusions: The present study clarifies the fact that chick germ cells of the medulla of both right and left ovaries are either discarded by a process of programmed cell death and/or released into medullary lacunae with increasing embryo age. © 1994 Wiley‐Liss, Inc.
Muscles of the pelvic outlet in the rhesus monkey (Macaca mulatta) with special reference to nerve supply
Authors: Akita Keiichi , Sakamoto Hirokazu , Sato Tatso
Published: February 2005

Background: The Manner of innervation of the muscles of the inferior limb, pelvic outlet, and tail in rhesus monkey (Macaca maulatta) was investigated in detail in 11 pelvic halves of lour males and two females.

Results: The origins of the pudendal nerve were widespread and overlapped the sacral plexus. After removal of the bone structures, detailed dissection revealed the origin of the pudendal nerve to ventrocaudally overlap the sacral plexus. This dorsoventral branching pattern between the sacral plexus and the pudendal nerve is similar to that in Urodela (akita, 1992b) Lacertilia (Akita, 1992a) and AVes (Akita et al., 1992a), and is a basis for morphological understanding of the muscles of the pelvic outlet.

Conclusion: The muscles of the pelvic outlet consist of the leavtor, sphincter, and tail muscle groups, based on the stratification of the supplying nerves the former two groups likely dervice from the ventral muscles of the inferior limb, and the latter group from the ventral caudal (trunk) muscles. © 1995 Wiley‐Liss, Inc.
Morphometric evaluation of volume shifts between intra‐ and extra‐cellular space before and during global ischemia
Authors: Schmiedl Andreas , Haasis G. , Schnabel Ph. A. , Gebhard M. M. , Richter J.
Published: February 2005

Background: It is well known that all forms of cardiac arrest lead to global ischemia combined with alterations in cellular and interstitial volume. The aim of this study was to investigate the nature of these alterations with respect to different methods of cardiac arrest and establish the extent of their mutual influence at the onset as well as during the course of global ischemia.

Methods: Three tested clinical methods were employed to induce cardiac arrest by a) aortic cross clamping, b) coronary perfusion with the cardioplegic solution St. Thomas, and c) coronary perfusion with the cardioplegic solution histidine‐tryptophane‐ketoglutarate (HTK). The arrested hearts were subjected to global ischemia at 25°C. The size of the myocytes, as well as the interstitial space of myocytes, was determined morphometrically. The contraction state of myocytes was evaluated according to a score.

Results: We found that the degree of contraction, as well as nature of alterations in the cellular and interstitial volumes, depended both on the form of cardiac arrest and on the duration of ischemia. The following relationships were established. High contraction at the onset of ischemia leads to expulsion of fluid from the interstitium between bundles of myocytes into the tissue clefts increasing their size. The decrease in contraction during ischemia leads to narrower tissue clefts. Cellular swelling at the onset of and during ischemia is caused by volume shifts between intracellular and interstitial space. An increase in cellular volume during global ischemia and/or additional contraction reduce the interstitium within bundles of myocytes. Sufficient relaxation and/or interstitial edema enlarge the interstitium.

Conclusions: Cellular and intersticial alterations seen at the onset and during the course of ischemia are dependent upon the method of cardiac arrest. Furthermore, a considerable mutual influence is exerted by the alterations in cellular and interstitial spaces. © 1995 Wiley‐Liss, Inc.
Matrix metallproteinases and TIMP‐1 localization at sites of osteogenesis in the craniofacial region of the rabbit embryo
Authors: Breckon Jeremy J. W. , Hembry Rosalind M. , Reynolds John J. , Meikle Murray C.
Published: February 2005

Background: The matrix metalloproteinases (MMPs) are a family of closely related enzymes, the principal members being the collagenases, gelatinases, and stromelysins. They are synthesized and secreted by connective tissue cells and are capable of degrading all the components of connective tissue matrices at physiological pH.

Methods: Patterns of synthesis and distribution of MMPs and their inhibitor, tissue inhibitor of metalloproteinases‐1 (TIMP‐1), are documented in the craniofacial region at sites of bone formation during both intramembranous (e.g., calvaria, maxilla, and mandible) and endochondral ossification (e.g., cartilaginous cranial base and synchondroses) using indirect immunolocalization.

Results: MMPs and TIMP‐1 were detected both as bright intracellular accumulations, indicating active synthesis, and as diffuse matrix‐bound extracellular deposits. Gelatinase‐A had an extensive distribution in osteogenic tissues and was detected both in cells of the periosteum and spongiosum and as extracellular deposits in the osteoid layer of newly formed bone. In addition, gelatinase‐AB synthesis was detected in osteoclasts. All regions of the early cartilaginous cranial base produced MMPs and TIMP‐1 were also documented in early tooth germs and in Meckel's cartilage.

Conclusions: These data document a prominent role for MMPs, and in particular gelatinase‐A, in mediating matrix degradation during osteogenesis. Their detection in tooth germs and Meckel's cartilage further indicates a role for MMPs and TIMP‐1 in matrix turnover during morphogenesis. © 1995 Wiley‐Liss, Inc.
Probing glucocorticoid‐dependent osteogenesis in rat and chick cells in vitro by specific blockade of osteoblastic differentiation with progesterone and RU38486
Authors: Tenenbaum Howard C. , Kamalia Nilupa , Sukhu Balram , Limeback Hardy , McCulloch Christopher A. G.
Published: February 2005

Glucocorticoids and sex‐steroids can modulate osteogenesis in vivo and in vitro. Although the effects of glucocorticoids on bone cells in vitro have been described in detail, the role of sex‐steroids is not as well defined. We examined whether sex‐steroids influence bone metabolism indirectly by regulating glucocorticoid effects on bone. Interactions of the sex‐steroid progesterone or its analog RU38486 with the glucocorticoid dexamethasone (dex) were studied in functional assays of osteogenesis. Three osteoblastic models were evaluated:(1) the rat bone marrow stromal cell (RBMC) nodule system; (2) the chick periosteal osteogenesis (CPO) model; and (3) ROS 17/2.8 cells. RU38486, progesterone, and unlabelled dex competitively inhibited 3H‐dex uptake by ROS 17/2.8 cells as well as its (3H‐dex) binding to cytosol preps.

Both RU38486 and progesterone inhibited dex‐induced increases in alkaline phosphatase in CPO cultures, in RBMC cultures, and in ROS 17/2.8 cells. Dex‐induced decreases in cell proliferation in ROS 17/2.8 cells were reversed by RU38486 but dex‐induced increases in proliferation in the CPO model were not affected. In CPO cultures, dex‐induced increases in collagen synthesis were inhibited completely by RU38486 and progesterone, Dex‐dependent nodule formation in the RBMC was blocked by RU38486. Both RU38486 and dex mediated reduction of calcium uptake in the CPO model but did not affect mineralized tissue area.

The data indicate that RU38486 and progesterone competitively inhibit dex‐mediated stimulation of osteogenesis in vitro; this inhibition is exerted on early but not late stage differentiation events of osteoprogenitor cells. © 1995 Wiley‐Liss, Inc.
Functional movements of putative jaw muscle insertions
Authors: Goto Tazuko K. , Langenbach Geerling E. J. , Korioth Tom. W. P. , Hagiwara Masaaki , Tonndorf Monica L. , Hannam Alan G.
Published: February 2005

Background: The craniomandibular muscles control jaw position and forces at the teeth and temporomandibular joints, but little is known regarding their biomechanical behaviour during dynamic function. The objective of this study was to determine how jaw muscle insertions alter position during different jaw movements in living subjects.

Methods: Computer 3D reconstruction of MR images and jaw‐tracking were combined to permit the examination of movement with six degrees of freedom. Maximum mandibular opening, protrusive and laterotrusive positions were recorded in four subjects, and the translation and rotation of the putative insertions of masseter, temporal, medial, and lateral pterygoid muscles were measured.

Results: The sizes and shapes of regional attachments varied markedly among subjects, and their displacement patterns were different in specific muscles. For instance, when the jaw closed to the dental intercuspal position from maximum gape, the region near the superior insertion site of the masseter moved backward and upward, whereas the region near the inferior insertion site displaced mainly forward. In three subjects, the jaw's rotational center during this act was ∼26–34 mm below the mandibular condyles.

Conclusions: Since the movements of each muscle part differ according to variations in the size and shape of insertion areas, individual musculoskeletal form, and patterns of jaw motion during function, the prediction of motion‐related muscle mechanics in any one subject is unlikely to be possible without direct measurement of the motion of visualized muscle parts. The present study shows that this information can be obtained. © 1995 Wiley‐Liss. Inc.
Microcirculation of gills and accessory respiratory organs of the walking catfish Clarias batrachus
Authors: Olson K. R. , Ghosh T. K. , Roy P. K. , Munshi J. S. D.
Published: February 2005

Background: An ability to extract oxygen directly from the atmosphere enables air‐breathing fish to survive otherwise debilitating hypoxic environments. Addition of accessory respiratory organs (ARO) necessitates changes in both the general circulatory system and the microcirculation of the respiratory epithelia. Understanding these modifications provides information on the efficiency of gas exchange organs as well as an indication of the evolutionary processes associated with adaptation to terrestrial habitats.

Methods: Vascular organization and structure of gills and ARO of the facultative air‐breathing walking catfish Clarias batrachus were examined by scanning electron microscopy of vascular replicas and fixed tissue.

Results: Well‐developed filaments are present on all four pairs of gill arches and they possess three vascular pathways: respiratory (arterioarterial), nutrient (arteriovenous), and interlamellar (arteriovenous), typical of teleosts. ARO, consisting of gill fans, dendritic organs on the second and fourth gill arch, and the suprabranchial epithelium are derived from gill tissue and retain structural features and arterioarterial vessels similar to gill filaments. Gill and ARO vessels are in parallel with each other, and together they are in series with the systemic circulation. Nutrient and interlamellar vessels are reduced in ARO.

Conclusions: Other than the presence of multiple ventral aortas, and an additional vessel connecting the suprabranchial epithelium to the dorsal aorta, there are no vascular shunts or anatomical modifications that indicate spatial separation of flow through the heart or between gills and ARO. However, a mechanism is proposed that would prevent unsaturation of dorsal aortic blood by local myogenic vasoconstriction of gill vessels when the fish is in hypoxic water. Despite considerable differences in the gross features of ARO in Clarias and Heteropneustes fossilis: (Olson et al. 1990 J. Morphol., 203:165), there are striking similarities in vascular organization and respiratory islet structure that suggest these ARO evolved in a common silurid ancestor and were later modified into an everted arborescent organ or inverted air sac, respectively. © 1995 Wiley‐Liss, Inc.
Myosin heavy chain expression within the tapered ends of skeletal muscle fibers
Authors: Rosser Benjamin W. C. , Waldbillig Donna M. , Lovo Stacey D. , Armstrong Jacalyn D. , Bandman Everett
Published: February 2005

Background: The pectoralis muscle of the chicken contains fast‐twitch glycolytic fibers, which during development undergo a transformation in their myosin heavy chain (MyHC) content from embryonic to a neonatal to an adult isoform (Bandman et al., 1990). Little, however, is known of MyHC expression within the ends of these or other muscle fibers. Here we test the hypothesis that the tapered ends of mature skeletal muscle fibers contain a less mature MyHC isoform than that typically found throughout their lengths.

Methods: We apply an ammoniacal silver histological stain for endomysium and monoclonal antibodies against neonatal and adult MyHCs of chicken pectoralis to transverse serial sections of pectoralis from five mature chickens. The “lesser fiber diameters” of populations of fibers from each bird are also measured.

Results: Most (∼81.8%) of the small (<12μm) and none of the larger (>20μm) diameter fibers contain the neonatal MyHC. Following these smaller fibers through serial sections, we show that they are the tapered ends of the larger fibers. Whereas neonatal MyHC is restricted to the tapered fiber ends, adult MyHC is present throughout the entire lengths of all fibers. We also demonstrate acetylcholinesterase (AChE) activity at some of these fiber ends.

Conclusions: We postulate that longitudinal growth of myofibrils in adult muscle is characterized by the sequential expression of MyHC isoforms similar to that observed in rapidly growing muscle and that the presence of the neurotransmitter hydrolase AChE at the tapered fiber ends may be related to the retention of neonatal MyHC. © 1995 Wiley‐Liss, Inc.
Kidney of elephants
Authors: Maluf N. S. R.
Published: February 2005

Background: Elephants are an important and isolated order. Their kidneys need substantial investigation and hitherto have not been portrayed even by a pyelogram.

Methods: Pyelograms and injection of vessels with colored acrylic emulsions were done initially. Dissection was under fiberoptics using a dissecting microscope with frequent measurements. Special areas were cut for microscopy (light and electron) and photography. Glomerular counts were done by macerating weighed pieces of cortex and later finding the cortical fraction of the renal parenchyma.

Results: The elephant kidney is devoid of dorsoventral symmetry. It is composed of 8 ± 2 lobes separated by fine interlobar septa. There is no reduction of lobes with maturity. The pelvis bifurcates at the sinus into primary branches or infundibula which dispatch a secondary branch or infundibulum into every lobe. Interlobar arteries and veins, nerves, fat, and connective tissue generally accompany every secondary infundibulum into its lobe. A major branch of the renal artery may perforate the renal capsule and course to the cortico‐medullary (C‐M) border independently of the secondary infundibulum to that lobe.

The number of glomeruli per kidney is approximately 15 × 106. In adults the glomerular mass is 4.9 ± 0.5% of the renal parenchyma and 6.7 ± 0.3% of the cortex. Areae cribrosae occur generally at low papillae. They are the outlets of numerous terminal collecting ducts which may be accompanied by a tubus maximus (T.M.) A T.M. of diameter 1.6 mm and length 10 mm may act as the only substitute for an area cribrosa.

Wide anastomoses between the two main renal veins occur within the renal sinus. Intralobar arteries and veins often course right through the outer medulla to and from, respectively, the C‐M border.

Conclusions: Anatomically, an elephant's kidneys appear to be able to concentrate urine only moderately. Their kidneys tend to resemble those of the manatee but not of the dugong. © 1995 Wiley‐Liss, Inc.
Patella of selected bats: Patterns of occurrence or absence and associated modifications of the quadriceps femoris tendon
Authors: Smith Bonnie J. , Holladay Steven D. , Smith Stephen A.
Published: February 2005

Background: Having observed the apparent absence of a bony patella in a Madagascar flying fox (Pteropus sp.), other species from the two suborders of bats (Megachiroptera and Microchiroptera) were examined to determine the presence or absence of a bony patella and the distribution of this feature among bats.

Methods: Gross, radiographic, and histologic examination of seven megachiropteran species representing four genera, as well as six microchiropteran species representing six genera, was performed.

Results: A bony patella was observed in all six microchiropteran and in three megachiropteran species. The tendon of the quadriceps femoris muscle in Microchiropteran species was composed mainly of dense regular connective tissue. The quadriceps tendon in Megachiropteran species with a patella contained an abundance of fibrocartilage and hyaline cartilage, unlike the quadriceps femoris tendon of the Microchiroptera or a laboratory mouse examined for comparison.

Conclusions: Four species of the megachiropteran genus Pteropus lacking a bony patella displayed a similar occurrence and distribution of fibro cartilage and hyaline cartilage within the quadriceps tendon as seen in the other bats. In reference to this singular feature, Pteropus is unique among the representatives of megachiropteran and microchiropteran genera examined here. © 1995 Wiley‐Liss, Inc.
Spectrum of looping disturbances in stage 34 chicken hearts after retinoic acid treatment
Authors: Bouman Hannie G. A. , Broekhuizen Monique L. A. , Baasten A. Mieke J. , Gittenberger‐De Groot Adriana C. , Wenink Arnold C. G.
Published: February 2005

Background: In a recently developed chick model the teratogen retinoic acid has appeared to induce a spectrum of double outlet right ventricle, which needs further detailed evaluation. It is known that retionic acid is able to induce cardiac malformations. Although the exact mechanism is not known, an interaction with neural crest cell function is thought to exist.

Methods: After treatment with 1 μg all‐trans retinoic acid at Hamburger and Hamilton stage 15 and reincubation until stage 34 of development 41 chicken embryos were evaluated macroscopically and microscopically, supported by graphic reconstructions. These retinoic acid treated embryos were compared with a control group (n = 8).

Results: The retinoic acid treated embryos could be divided in three groups. Group 1 (23/41) had an intact septum, group 2 (11/41) had an isolated ventricular septal defect (VSD), and group 3 (7/41) had a double outlet right ventricle (DORV). Besides, in the group with an intact septum 11 hearts showed an abnormal course of the subaortic outflow tract. In the group with DORV a straddling tricuspid orifice (7/8) and a double inlet left ventricle (1/8) could be distinguished. Considering the external contour, the hearts in the DORV group all showed a dextroposed arterial pole. Malformed pharyngeal arch arteries were found in all three groups (11/41) and with a great diversity.

Conclusions: The present cardiac malformations in the chicken as a result of retinoic acid treatment are part of a continuous spectrum, varying from hearts with an intact ventricular septum and a normal course of the subaortic outflow tract to a double outlet right ventricle with a straddling tricuspid orifice or even a double inlet left ventricle. A remarkable observation in this spectrum concerns the correlation of malformations of the inflow and outflow tracts, which is explained as a cardiac looping disturbance. The disturbance of the looping process seems to lead to malalignment of septal components, although, in the chick, retinoic acid does not in general interfere with the formation of these septal components themselves. © 1995 Wiley‐Liss, Inc.
Calcium‐binding Proteins in Avian Herbst and Grandry sensory corpuscles
Authors: Del Valle M. E. , Ciriaco E. , Bronzetti E. , Albuerne M. , Naves F. J. , Germana G. , Vega J. A.
Published: February 2005

Background: Calcium‐binding proteins (Ca2+‐BP) are involved in the homeostasis of intracellular calcium ions (Ca2+), which play a key role in electrogenesis, and therefore in somatosensory transduction, within sensory corpuscles. This study analyze the distribution of several Ca2+‐BP in avian Herbst and Grandry sensory corpuscles.

Methods: Specimens of beak skin and tongue from ducks and pigeons were studied immunohistochemically using antibodies against S100 protein (S100P), calretinin (CR), calbindin D28K (CB), and parvalbumin (PV). Moreover, neurofilament proteins (NFP) and neuron‐specific enolase (NSE) were studied in parallel.

Results: In Herbst corpuscles: (1) specific immunoreactivity (IR) for S100P was always observed labelling the inner‐core cells and was also found in the capsule of duck Herbst corpuscles; (2) all the other investigated Ca2+‐BP were found primarily in the inner‐core, without relevant species‐specific differences, but also in the central axon and in the capsule (CB and PV). In Grandry corpuscles, the Grandry cells (1) can be subdivided on the basis of S100P IR; (2) displayed a strong CR IR, moderate PV IR, and weak CB IR; (3) were negative for NFP or NSE. On the other hand, the central axon of both kinds of sensory corpuscles showed NFP and NSE IR, and the intraepidermic Merkel‐like cells were NFP IR.

Conclusions: Present results provide evidence for the presence of several Ca2+‐BP in two kinds of rapidly adapting avian sensory corpuscles, and also for the existence of species‐specific differences in the localization of some of them. These findings suggest that Ca2+‐BP may be involved in the maintenance of Ca2+ homeostasis in avian sensory corpuscles, and therefore in mechano‐electric transduction. © 1995 Wiley‐Liss, Inc.