bluuebunny/crossref_metadata_2025 huggingface dataset:
The leptomenix in normal baboon brain contain receptors for dihydrotestosterone but not estradiol
Authors: Sheridan Peter J. , Fujimoto Masahito
Published: February 2005

There exists a sexual dimorphism in the occurrence of meningiomas. Biochemical binding assays conducted on samples of meningiomas have indicated a high incidence of progesterone and androgen receptors in these tumors. However, similar studies have been very controversial as to the existence of estrogen receptors in these tumors. The present study was conducted to determine whether the normal leptomenix contains estrogen and androgen receptors in a primate model, namely the baboon. Three male and three female baboons were injected with either 3H‐dihydrotestosterone (3H‐DHT) or 3H‐estradiol. One animal from each group received 3H‐steroid + 100‐fold unlabeled corresponding steroid to serve as control. One hour after injection of the 3H‐steroids the animals were sacrificed. Their brains were removed and processed for autoradiography. Nuclear uptake and retention of 3H‐DHT and/or one of its metabolites was found in 25‐50% of the cells in pieces of the arachnoid adhering to the brain, cells of the glial membrane, cells in large fiber bundles, presumably oligodendroglia, and cells lining the Virchow‐Robins spaces. No such localization was found with 3H‐estradiol. This study provides the first anatomical evidence for the presence of androgen receptors in the normal leptomenix and glial cells of the baboon. These findings are discussed in relation to the possible clinical significance of the use of steroids to modulat the growth of meningiomas.
Distribution of myofiber types in the hip and thigh musculature of sheep
Authors: Suzuki Atushi , Tamate Hideo
Published: February 2005

The composition of muscles by myofiber type is associated with their locomotory or postural functions. In the present study the composition of the hip and thigh musculature of sheep by myofiber types and the differences in their distribution were examined. Myofibers were classified into type I, IIA, and IIB myofibers by differences in myosin ATPase and NADH tetrazolium reductase (NADH‐TR) activity. The vastus intermedius muscle consisted only of type I myofibers, which exhibit weak alkali‐stable myosin ATPase and strong NADH‐TR activity. The gluteus accessorius and profundus muscles had more than 50% type I myofibers. The other muscles had less than 50% type I myofibers as a whole. Type I myofibers were concentrated in the deep portions of the gluteus and quadriceps femoris muscles, which extend the hip and stifle joints, and of the pectineus muscle. They were scattered evenly in the caudally situated locomotory muscles in the thigh. Type IIA myofibers, characterized by strong alkali‐stable myosin ATPase and NADH‐TR activity, showed little difference in distribution in the hip and thigh muscles. Type IIB myofibers, characterized by strong alkali‐stable myosin ATPase and weak NADH‐TR activity, were distributed more in the cranial, caudolateral, and caudomedial portions than in the middle portions of the thigh. The distribution to type IIB myofibers is suited to powerful flexion and extension of the thigh and leg. In the hip and thigh musculature, it appears that type I myofibers are effectively distributed to maintain a standing posture without diminishing the propulsive force of the hindlimb.
Accessory limb production by nerve‐induced cell proliferation
Authors: Egar Margaret W.
Published: February 2005

The deviation of large limb nerves to a more proximal skin wound yielded a high proportion of accessory limb respones in different age groups of Ambystoma mexicanum (axolotls). In some instances the deviated nerve was positioned on skin previously grafted from an animal of different age and pigmentation from that of the host. Grafts were found not to be a necessary prerequiste for accessory limb induction, but the presence of wound epithelium was required. The rule of distal morphogenesis was expressed in reference to the level at which the nerve was cut, not in reference to the wound site where the accessory actually developed.

The upper arm proved to be a more favorable site for accessory limb production than the flank or the leg under the conditions of the present experiments, in which little or no damage was done to the underlying muscles. The orientation of the accessory limb was extremely varied despite the uniformity of the surgical procedure.
Three‐dimensional presentation of cell migration in the periodontal ligament of the rat incisor
Authors: Michaeli Yael , Steigman Shulamit , Barad Amir , Weinreb Miron
Published: February 2005

The progenitor compartments and cell migration were examined in the tooth‐related periodontal ligament (t‐PDL) of rat incisors. A pulse injection of 3H‐Tdr was administered to 15 rats (200 gm each) and the animals were killed in groups of five, at 1 hr and at 1 and 2 weeks after injection. Three‐dimensional analysis of cell counts and labeling index demonstrated the existence of two progenitor compartments (PC). The apical PC (responsible for 70% of synthesizing cells) was concentrated in the apical 5 mm of the t‐PDL. The paracemental PC (30% of synthesizing cells) was located along and around the cementum, occupying 24 μm of the t‐PDL. The cells from the apical PC migrated incisally at a rate of 6 mm/week, which is a rate similar to that of tooth eruption. The cells from the paracemental PC moved in a transverse direction toward either bone or cementum at the much slower rate of 16 μm/week.
Ultrastructure of the olfactory system of three newborn marsupial species
Authors: Gemmell R. T. , Nelson J.
Published: February 2005

The ultrastructure of the olfactory apparatus of three newborn marsupial species, the northern native cat, the brushtail possum, and the northern brown bandicoot, were examined. The olfactory epithelium and olfactory bulbs were at a similar stage of development in all three species. Receptor cells with cilia were observed, and although the olfactory system undergoes further differentiation during pouch life and although the olfactory epithelium and bulb of the newborn differs from that of the adult, these facts do not preclude the ability of the newborn to detect smell. The presence of touch receptors around the mouth region and of sensory cells within the olfactory epithelium would suggest that touch and smell are two of the senses allowing the newborn marsupial to reach the pouch.
Ultrastructural immunocytochemical studies of the localization and distribution of somatostatin, calcitonin, calcitonin gene‐related peptide, and substance p in the bat thyroid follicle
Authors: Nunez Eladio A. , Payette Robert F. , Tamir Hadassah , Gershon Michael D.
Published: February 2005

Electron microscope immunocytochemistry was used to determine the intracellular localization and distribution among follicular elements of four peptides: calcitonin, somatostatin, calcitonin gene‐related peptide (CGRP), and substance P in the thyroid glands of bats captured in the prehibernation phase of their annual life cycle. Previous studies have shown that this period of the hibernation—activity cycle is characterized by the accumulation and storage of secretory granules in parafollicular cells. Sites of binding of primary antisera to each of the four peptides were identified by means of affinity‐purified secondary antisera directly coupled to colloidal gold particles. Calcitonin and somatostatin immunoreactivities were found in all parafollicular cells examined and in every secretory granule within these cells. CGRP was also found in all parafollicular cells examined (n = 75) but only in about half of their secretory granules. In contrast to these peptides, substance P immunoreactivity was not found in any parafollicular cells, but was localized exclusively in nerve endings within the basement membrane of the follicle.
Intra and juxtavagal paraganglia: A topographical, histochemical, and ultrastructural study in the human
Authors: Plenat F. , Leroux P. , Floquet J. , Floquet A.
Published: February 2005

The topographical, ultrastructural, and histochemical features of 23 human vagal paraganglia were analyzed. Nineteen of the 23 paraganglia were found in previously unreported sites; 18 of the 19 were in the cervical part of the nerve, between the carotid bifurcation and the superior thoraco‐cervical inlet, and one paraganglion was located in the retrothyroidal part of the left inferior laryngeal nerve. The results of ultrastructural studies (2 cases), the histochemical and formaldehyde‐induced‐fluorescence studies (3 cases), and specific acetylcholinesterase activity (one case) demonstrate that these structures fulfill many of the modern criteria for paraganglionic tissue. In addition to paraganglia, single, isolated neurons or true microganglia were always found along the trunk and branches of the vagus nerve when multiple sections were examined.
Expression of intermediate filaments and desmoplakin in vertebrate olfactory mucosa
Authors: Ophir Dov , Lancet Doron
Published: February 2005

The expression of intermediate filaments (IF) and desmoplakin was investigated in frog, bovine, and human (fetal) olfactory mucosa. IF are tissue‐specific molecular cytoskeletal markers; desmoplakin is the major desmosomal protein. Positive immunoreactivity was observed in the epithelium and in the subepithelial Bowman's glands to keratin and to desmoplakin, indicating the epithelial nature of this tissue. Desmin, neurofilaments, and glial fibrillary acidic protein (GFAP) were not detected in the mucosa. The absence of neurofilaments and GFAP in the tissue containing sensory neurons and glia‐like supporting cells is a unique feature and may be related to the fact that the chemosensory neurons are situated in a bonafide epithelium and are known to undergo continuous turnover. In view of the controversy regarding the expression of vimentin were used; weak or no labeling was found in the epithelium, whereas mesenchymal cells in the lamina propia were labeled with all three antibodies. Olfactory nerve fascicles in the lamina propia were heterogenously labeled: VIM 13.2 gave very weak labeling; aVimAS showed mild labeling and SBV‐21 showed intensive labeling in the nerve fascicle. This heterogenous labeling pattern may suggest that olfactory vimentin is distinct in reacting only with some of the antivimentin antibodies.
Scanning electron microscope study of elastic fibers of the loose connective tissue (superficial fascia) in the rat
Authors: Imayama Shuhei , Braverman Irwin M.
Published: February 2005

A combination of intravascular resin injection and formic acid incubation was utilized to study the three‐dimensional arrangement of the elastic fibers in the loose connective tisue (superficial fascia) of the rat limb by scanning electron microscopy (SEM). The cast of the microvasculature served as a scaffolding for the otherwise collapsible connective tissue.

SEM study demonstrated that the elastic fibers did not form an anastomosing network but were arranged in multiple layers. The fibers in each layer lay parallel to each other but were oriented differently from the fibers in the layers on either side, thereby producing a meshwork. Each individual fiber was composed of a small bundle of discrete fibrils. Some of these component fibrils separated from the parent fiber and united with other fibers, thus producing branching. The elastic fiber either decreased or grew in size by the respective sharing or joining of these component fibrils with neighboring fibers in their respective layers. Interconnections between elastic fibers of different layers were rare.

These findings may provide a morphological explanation for the characteristic function of the superficial fascia, which allows the skin and underlying muscles to have a rapid and extensive alteration in their relative positions.
Morphology of the mandibulo‐stylohyoid ligament in human adults
Authors: Shimada Kazuyuki , Gasser Raymond F.
Published: February 2005

The mandibulo‐stylohyoid ligament is a consistently occurring connective tissue band or sheet that courses between the angle of the mandible and the stylohyoid ligament. Previously, in a few instances it has been variously named and described as a thickening of deep cervical fascia. Recently, Shimada et al. (1986) described the connective tissue thickening and named it the mandibulo‐stylohyoid ligament because of its arrangement and attachments. In the present study the ligament was dissected in 99 adult cadavers (both white and black, 98 right sides, 95 left sides). It was present in all of the specimens examined and has been classified into three types according to refinements in its morphology. Type 1: The ligament was a thick, separate band that coursed from the region of the angle of the mandible to the stylohyoid ligament. Type 2: The ligament had the same attachments as Type 1 but was more extensive, being continuous with the stylomandibular ligament. Type 3: The ligament had the same attachments as Type 1 but was thin and less well developed. The Type 1 arrangement occurred 41% of the time, Type 2, 37% of the time, and Type 3, 22% of the time. The consistency and arrangement of the ligament suggests an important role of additional structural support in the region of the angle of the mandible and hyoid bone.
Expression of collagen adhesion proteins and their association with the cytoskeleton in cardiac myocytes
Authors: Terracio Louis , Gullberg Donald , Rubin Kristofer , Craig Susan , Borg Thomas K.
Published: February 2005

Previous investigations have shown that specific cell surface glycoproteins on rat hepatocytes (COLL‐CAM) are involved in the recognition of interstital collagens (Rubin et al., Exp. Cell Res., 164:127–138, 1986). Western blot analysis with anti‐COLL‐CAM antibodies revealed the presence of a variable but restricted number (two) of glycoproteins in detergent‐extracted membranes from rat hearts at various developmental stages. Using antibodies against these collagen adhesion proteins, we show an expression of the antigens during different developmental stages of the rat heart and during cardiac hypertrophy. This expression is described morphologically by immunohistochemical staining of cell surfaces of freshly isolated myocytes from neonates, normal adults, and hypertrophied adult hearts. Antibodies made against COLL‐CAM were localized on the cell surface of cardiac myocytes and antibodies against talin and vinculin co‐localized in a similar position on the inside of the cell. Antibody staining appears to be increased at times when collagen synthesis is high (neonate and cardiac hypertrophy) and low when collagen synthesis is low, as in the normal adult. These results indicate that collagen adhesion proteins may play an important role in linking the extracellular matrix to the cytoskeleton in the heart.
Localization of fibronectin in megakaryocytes of fetal liver
Authors: Bockman Dale E. , Gulati Adarsh K.
Published: February 2005

Antibodies specific for fibronectin were utilized to determine the sites of localization in the liver during development. The livers of fetal rats from each of gestation days 11‐19, and from days 1 and 8 postpartum, were studied by fluorescence microscopy. Fibronectin was localized predominatly in megakaryocytes and megakaryocyte precursors, and to a lesser extent in the extracellular matrix surrounding blood vessels and between hepatocytes and sinusoids. The cytoplasm of megakaryocytes and their precursors displayed bright fluorescence but their nuclei were negative for fibronectin. Hepatocytes had negative or faint fluorescence. Megakaryocytes were present in the liver from day 12, and were numerous from day 13 through most of the rest of gestation. The relative numbers of megakaryocytes decreased in later gestation; at 8 days postpartum only a few were observed per section. Hepatic megakaryocytes appeared before megakaryocytes were established in spleen and bone marrow. The early and persistent high levels of fibronectin in hepatic megakaryocytes, in the absence of comparable localization within hepatocytes, leads us to the hypothesis that megakaryocytes are important in establishing circulating fibronectin levels in the fetus. Similarly, bone marrow megakaryocytes may contribute to circulating fibronectin in the adult.
Tissue‐specific granularity of gap junction cytoplasmic surface revealed by rapid‐freeze, deep‐etch replicas
Authors: Shibata Yosaburo , Izumi Toshihiro , Yamamoto Torao
Published: February 2005

Previous rapid‐freeze, deep‐etch replica studies have revealed the differences between heart and liver gap junctions; cytoplasmic surfaces of in situ and phenylmethylsulfnoyl fluoride (PMSF)‐unproteolyzed isolated cardiac gap junctions (MW 47 kD) have a particulate substructure, which is absent both in the proteolyzed heart junctions (MW 29 kD) and in the liver junctions isolated with PMSF (MW 28 kD). The present deep‐etch replica studies of gap junction cytoplasmic surface (CS) membranes in several tissues of rats and mice were performed to examine whether or not this difference between liver and heart is typical of variations in gap junction proteins from tissue to tissue.

In surface mucous cells of the stomach, intestinal epithelial cells, and kidney tubule cells, these epithelial gap junctions always showed smooth cytoplasmic surfaces, similar to the liver gap junctions. In contrast, in the atrial myocardium, aortic endothelium, and the ciliary process, cytoplasmic surface membranes of the gap junctions consistently revelaed particulate patterns. Close examinations disclosed that those granular structures were not merely attached to the membrane surface, but they also protruded from the membrane interior as an integral component of gap junctions particles. Furthermore, in the pregnant rat uterus at term, cytoplasmic surface membrances of myometrial smooth muscle gap junctions were particulate, but those of endometrial epithelium were smooth.

The present observations strongly suggest that tissue specificity exists in cytoplasmic surface structures of gap junctions between the “true” epithelial and the noneepithelial tissues: the nonepithelial gap junctions contain the additional cytoplasmic surface domain that is absent in the gap junctions of “true” epithelial origin.
Cell proliferation in chick oral membrane lags behind that of adjacent epithelia at the time of rupture
Authors: Miller Sue Ann , Olcott Christopher W.
Published: February 2005

Radioautographic analysis showed that ectoderm and endoderm cells in chick oral membrane continued to label with tritiated thymidine through the period of rupture, but their frequency of labeling was significantly lower than those of adjacent epithelia. Frequency of labeling increased in adjacent ectoderm and endoderm, while oral membrane rates remained relatively low, suggesting that growth in the membrane lags relative to adjacent epithelia. Relatively greater proliferation in adjacent epithelia could generate tension and pull apart the thinned oral membrane. Differentials in rates of cell proliferation, when considered along with knowledge of cellular rearrangements following changes in basal lamina and matrical components, suggest that differential growth is an important force in rupture of the avian oral membrane.
Immunocytochemical localization of hepatic fatty acid binding protien in the rat intestine: Effect of fasting
Authors: Iseki Shoichi , Hitomi Masahiro , Ono Teruo , Kondo Hisatake
Published: February 2005

Localization of hepatic fatty acid binding protein (h‐FABP) in the small and large intestines of rats was studied by light and electron microscopic histochemistry using the peroxidase‐antiperoxidase (PAP) method. In the small intestine of rats fed ad libitum, an intense FABP immunoreactivity was confined to the absorptive epithelial cells of the villi, but not of the crypts. The lowest margin of the immunoreactive cell sheet was closer to the crypts in the proximal than in the distal portions of the small intestine. In the large intestine, FABP immunoreactivity was present in the surface epithelial cells, with higher intesity in the proximal than in the distal portions of the intestine. After fasting rats for two days, many crypt cells exhibited intense immunoreactivity for h‐FABP, resulting in an extension of the lowest margin of the immunoreactive cell sheet deep into the crypts. Such expansion of the immunoreactive cell population was reversed by refeeding the animals. With regard to the intracellular localization of immunoreactivity in the jejunum, the basolateral portion of the cytoplasm exhibited a more intense immunoreaction than the apical portion in the majority of immunoreactive cells lining the villi, whether the animals were fed or fasted. The immunoreactive products appeared in the cytoplasmic matix without association with any subcellular structures. Although clusters of cells located in the villous tips exhibited evenly dense immunostaining throughout the entire cytoplasm, no increasing gradient in the intensity of the immunoreactivity from the base to the apex of the cytoplasm was seen in any epithelial cells. The present findings imply that h‐FABP could be involved in the uptake and metabolism of plasma‐derived as well as dietary‐free fatty acids by the intestinal epithelial cells.
S‐100 protein‐immunoreactive cells in the bovine ovary
Authors: Kamiya Shinji , Tsukushi Masumi , Yamano Shuji , Daigo Masayuki
Published: February 2005

The present study deals with an immunohistochemical localization of S‐100 protein in the bovine ovary. Immunoreactivity for S‐100 was observed in various types of cells, as well as in cells of the nervous system. The endothelial cells of arterial vessels, blood capillaries, and lymph vessels; the epithelial cells of ovarian cysts; and the oocytes of normal and atretic follicles showed an S‐100 protein positivity. The immunoreactivity also was found in the epithelial cells of the rete ovarii. No cells other than these showed immunoreactivity to the anti‐S‐100 serum. S‐100 protein can be a useful marker for providing information on ovarian function.
Effects of progesterone and a progesterone antagonist (RU486) on germinal vesicle breakdown in the mouse
Authors: Batten Bruce E. , Roh Sung I. , Kim Moon H.
Published: February 2005

The possibility that ovarian steroids may participate in the inhibition of meiosis has not been rigorously examined. Since progesterone levels are extremely high in follicular fluid prior to ovulation, we tested the possibility that this steroid may be involved in oocyte maturation. To this end, we collected follicular oocytes and cultured them in the presence of dibutyrl cAMP (Bt2), progesterone, and/or the progesterone antagonist RU486 and assessed maturation evidenced by germinal vesicle breakdown (GVBD). Denuded oocytes or cumulus masses collected in the presence of 1 mM Bt2 and subsequently cultured in 25 μM progesterone did not undergo GVBD. However, denuded oocytes and cumulus masses collected in the presence of progesterone and not Bt2 did undergo GVBD (93%). Concentrations of Bt2 (150 μM) that would not inhibit GVBD were inhibitory when used in the presence of progesterone (1–25 μM). Competition experiments using increasing concentrations of the progesterone antagonist RU486 (1–100 μ) did not block the ability of progesterone to enhance the activity of Bt2. We conclude that progesterone alone does not block GVBD; however, in the presence of low concentrations of cAMP it is extremely effective in blocking GVBD. The synergistic activity of progesterone does not appear to be mediated by the progesterone receptor. The data suggest that progesterone and cAMP may operate cooperatively to inhibit meiosis in the ovarian follicle.
Epidermis, basement membrane, and connective‐tissue healing after amputation of mouse digits: Implications for mammalian appendage regeneration
Authors: Neufeld Daniel A.
Published: February 2005

Soft tissues from amputation sites of mice were examined at both light and electron microscope levels to determine whether features of growth buds (blastemas), which are necessary for amphibian limb regeneration, exist in nonregenerating mice. Several such features were found. A small area of the wound bed was covered by wound epithelium which, as in regenerating newt limbs, initially lacked an underlying basement membrane. Serially sectioned digits revealed blastemalike growth in the subdermal layer surrounding periosteal chondrogenic cells. Mesenchymelike cells were seen among the fibroblasts and leucocytes within the proliferating tissues. However, no evidence of dedifferentiation was seen in the dermis, which persisted as an apparent intact obstruction to growth bud formation. Existence of the essential ingredients of growth buds and soft‐tissue proliferation adjacent to chondrogenic cells proximally suggest that the tissues of mammalian healing may differ quantitatively rather than qualitatively from tissues of appendage regeneration. This premise is encouraging for efforts at growth enhancement in mammals.
Occurrence of calcitonin‐positive C cells within the distal vagal ganglion and the recurrent laryngeal nerve of the chicken
Authors: Kameda Yoko
Published: February 2005

The chicken ultimobranchial glands are richly supplied with nerve fibers originating from both the main trunk of the vagus nerve and its branch‐the recurrent laryngeal nerve. C cells immunoreactive for calcitonin were invariably found in the large nerve bundles distributed throughout the ultimobranchial glands. In addition, these cells were often present within the distal vagal ganglia and the recurrent laryngeal nerves. The frequency of occurrence and the pattern of distribution of the C cells in the distal vagal ganglia and the recurrent laryngeal nerves were determined in chickens of various ages by means of an immunoperoxidase method with anticalcitonin and antineurofilament antisera. The left and right sides of the ultimobranchial region were asymmetrical. The left ultimobranchial gland was in close contact with the vagus nerve trunk, especially with the distal vagal ganglion, but it was separated from the recurrent laryngeal nerve. The right gland contacted the recurrent laryngeal nerves, its medial edge being frequently penetrated by the nerve, but the gland was separated from the distal vagal ganglion. On the left side, C cells were found in 25 out of 39 distal vagal ganglia but they were not distributed in the recurrent laryngeal nerve. On the right side, the cells were present in 28 out of 43 recurrent laryngeal nerves but absent in the distal vagal ganglia. The results indicate that the C cells secreting a hormone calcitonin can enter into nerves, but their occurrence is restricted to the nerves in close proximity to the ultimobranchial glands. Electron microscopic studies revealed that C cells in the nerves received numerous axon clusters enveloped with Schwann cell cytoplasm. Naked axons regarded as axon terminals were found in direct contact with the surface of C cells. They were mainly composed of efferent‐type nerve endings showing the accumulation of numerous small clear vesicles and a few large dense‐cored vesicles. In addition, C cells were partly covered with the long cytoplasmic processes of Schwann cells and were also in contact with the Schwann cell perikarya. The C cells in nerves appear to be controlled by neural stimulation.
Osteocalcin‐hydroxyapatite interaction in the extracellular organic matrix of bone
Authors: Hauschka Peter V. , Wians Frank H.
Published: February 2005

Osteocalcin, a major noncollagenous matrix protein of bone, dentin, and cementum, is found in tight association with the calcium phosphate mineral phase of these tissues. This article reviews the structural data for osteocalcin relevant to mineral adsorption. The equilibrium‐binding properties for Ca2+ ions and hydroxyapatite are considered, along with the apparent physicochemical effects of osteocalcin on bone mineral dynamics. Several of osteocalcin's possible biological activities (involvement in mineralization, chemoattraction, and leukocyte elastase inhibition) are discussed in relation to the mineral‐adsorption characteristics of this protein.
Mineral phases of calcium phosphate
Authors: Nancollas G. H. , Lore M. , Perez L. , Richardson C. , Zawacki S. J.
Published: February 2005

Many studies of calcium phosphate precipitation have been made using relaxation techniques in which the concentrations of the lattice ions are allowed to decrease as equilibrium is approached. Since the nature of the phases that form depend markedly on the solution composition, this decrease can lead to concomitant phase transformations during the crystallization experiments. The results of the present constant composition (CC) studies show that defect apatites may be formed under conditions of sustained supersaturation with a non‐stoichiometric coefficient dependent on the pH of the growth medium. An important factor in analyzing these experiments is the initial surface modification and ion‐exchange processes involving H+ and Ca2+ ions after inoculation of the supersaturated solutions. Thereafter, active growth sites may be eliminated as the crystals undergo lattice perfection. Transformation of dicalcium phosphate dihydrate to octacalcium phosphate, involving dissolution and subsequent nucleation and growth of the new phase, is also influenced by surface roughening of the initial phase. Typical inhibitors that reduce the rate of growth of seed crystals in supersaturated solutions may actually induce the nucleation of calcium phosphate phases when immobilized on inert surfaces. This may be a factor in the modulation of crystal growth in many biological systems.
Morphometric analysis of the development of sexual dimorphism of the mouse pelvis
Authors: Iguchi Taisen , Irisawa Satoko , Fukazawa Yugo , Uesugi Yasuo , Takasugi Noboru
Published: February 2005

Sex differences in the innominate bone of C57BL/Tw mice were studied morphometrically from the day of birth to 120 days of age. In neonatal male and female mice, a small cartilaginous spine was found on the basal part of ischium. This process disappeard in males within 24 hours after birth, whereas in females it remained until at least 30 days. Other sexual differences in the pubis and the ischium appeared at 30 and 120 days, respectively. The pubis in female mice was longer and thinner than that in the males, and the ischium in male mice was shorter and thicker than that in the females. Thirty‐day‐old female mice treated neonatally with testosterone or 5α‐dihydrotestosterone possessed public bones shorter and thicker than those to the age‐matched untreated females. Pubes in male mice castrated at the day of birth were thinner than those in intact males. These findings suggest that the shape of the innominate bone is transformed to the male type under the influence of early postnatal androgen.
Intercellular communication between rat anterior pituitary cells
Authors: Soji Tsuyoshi , Herbert Damon C.
Published: February 2005

Cell‐to‐cell communication within the rat anterior pituitary was investigated in 60‐day‐old male rats with immunohistochemistry, scanning electron microscopy, freeze‐fracture electron microscopy, and conventional transmission electron microscopy. A dense cytoreticular network of cytoplasmic processes from the folliculostellate cells was found to contain immunoreactive S‐100 protein and was observed throughout the anterior pituitary. Nonimmunoreactive cells, which were granular, were situated in the center of each network. Almost all of the granulated cells were situated in close proximity to the folliculostellate cells. Scanning electron microscopy revealed that the gland consisted of microlobules enclosed by a basal lamina. On the surface of the microlobules were blood vessels whose branches invaded its internal structures. Cytoplasmic processes from folliculostellate cells projected outside the microlobule. Freeze‐fracture electron microscopy demonstrated the presence of numerous intramembranous particles on the P‐face of the plasma membrane. Scattered on the cell surface were groups of particles forming gap junctions. Meshworks of ridges which were representations of tight junctions were also observed near clusters of microvillous fragments. Clusters of particles forming small gap junctions were located between the meshworks of tight junctions. Small gap junctions were clearly observed by conventional electron microscopy between junctional complexes in a manner similar to that seen by freeze‐fracture electron microscopy. Slender cytoplasmic processes of folliculostellate cells came in contact near the basal lamina and were adjoined by small gap junctions. The ratio of nongranular cells which contained gap junctions to those in which the junctions were absent was about 1:1. The size of the gap junctions ranged from 50 nm to 3 μm. No gap junctions were observed along the plasma membranes of the granular cells. The significance of an intercellular communication system within the anterior pituitary gland of the rat is to establish a mechanism for rapid transmission of information in an organ which lacks direct innervation.
Ultrastructural study of the coiled body and a new inclusion, the “mykaryon”, in the nucleus of the adult rat sertoli cell
Authors: Schultz Michael C.
Published: February 2005

Random and serial thin sections of the nucleus in adult rat Sertoli cells were examined by electron microscopy. Besides the previously reported nucleoli and heterochromatin masses, the nuclei contain a coiled body and a new structure, the “mykaryon.”

The coiled body is 835 nm in maximum diameter. It is composed of distinct elements referred to as “coils”. They are 32 nm wide on average and resemble the nucleolar pars fibrosa in their intense staining with heavy metal salts and their composition of narrow filaments. The coiled body is often close to a nucleolus, though no direct contact is established, and it sometimes exists at a distance from the nucleolus.

The mykaryon is spherical, 460 nm in maximum diameter, and composed of a tridimensional network of 7–26 nm‐wide electron‐opaque “cords” separated by slighly thinner spaces. It has not been observed in the vicinity of a nucleolus. A literature survey showed no previous mention of a structure similar to the mykaryon. The coiled body and the mykaryon are interpreted as normal constituents of the Sertoli nucleus in the adult rat.
Musculotopic innervation of the primary flight muscles, the pectoralis (pars thoracicus) and supracoracoideus, of the pigeon (Columba livia): A WGA‐HRP study
Authors: Sokoloff A. , Deacon T. , Goslow G. E.
Published: February 2005

The distribution of motoneurons innervating the primary depressor and elevator muscles of the wing of the domestic pigeon (Columba livia) was studied by using the retrograde axonal tracer lectin‐conjugated horseradish peroxidase (WGA‐HRP). Injection of WGA‐HRP into the pectoralis (pars thoracicus) labeled neurons in the ventromedial corner of the lateral motor column of the spinal cord. These neurons were arranged in a column extending from spinal segment X or XI to spinal segment XII or XIII. The pectoralis, the primary depressor muscle of the wing, consists of two parts which are anatomically and functionally distinct, the sternobrachialis (SB) and thoracobrachialis (TB). Injection into the SB labeled neurons in the rostral and middle regions of the pectoralis motoneuron column. In contrast, injection into the TB labeled neurons in the middle and caudal regions of the pectoralis motoneuron column. Injection into the primary elevator muscle of the wing, the supracoracoideus, labeled neurons in the lateral motor column in spinal segments X and XI. These motoneurons were located dorsolateral to motoneurons labeled following pectoralis injection. These data demonstrate musculotopic segregation of the motoneurons innervating the primary flight muscles in the pigeon and, further, illustrate that the SB and TB subregions of the pectoralis are innervated by discrete aggregations of motoneurons.
Light microscopic immunocytochemical study of fibrous sheath and outer dense fiber formation in the rat spermatid
Authors: Oko Richard , Clermont Yves
Published: February 2005

The formation of the fibrous sheath (FS) and outer dense fibers (ODF), two major cytoskeletal components of the tail of spermatozoa, was analyzed in the seminiferous epithelium by immunoperoxidase techniques applied to paraffin‐embedded testicular sections. Antibodies were prepared from purified FS and ODF fractions and from major 75 and 14.4 kDa FS polypeptides and major 32‐26 14.4 kDa ODF polypeptides. The immunostaining results showed that the production of FS and ODF proteins appeared to be exclusive to step 9‐19 spermatids and lasted over the duration of a full cycle of the seminiferous epithelium, or 12.8 days. During this period there was seemingly an initial lag of short duration between the synthesis and assembly of FS and ODF proteins followed by a long process of coordinated activity. Peak cytoplasmic immunoreactivity was reached in step 15 for FS proteins and midstep 16 for ODF proteins and and remained elevated thereafter for approximately 80 hr for both FS and ODF proteins. The immunoreactivity was more uniform and diffused for FS proteins and granulated or clumpy for ODF proteins. Assembly of FS proteins along the axoneme proceeded in a distal to proximal direction while for ODF proteins assembly proceeded in a proximal to distal direction. The main route of elimination of residual cytoplasmic FS and ODF proteins appeared to take place through the cytoplasmic droplets and residual bodies, respectively. There appeared to be no variation in step reactivity between the major ODF polypeptides tested and only minor variation in step reactivity between the major FS polypeptides tested. However, although the 14.4 kDa polypeptides of FS and ODF share antigenic determinants, they do not appear to be identical, because they presented different immunolocalizations during spermiogenesis and different directions of assembly along the axoneme.
Phagocytosis of collagen by mouse decidual cells
Authors: Zorn Telma M. T. , Tania Bijovsky A. , Bevilacqua Estela M. A. F. , Abrahamsohn P. A.
Published: February 2005

Collagen fibrils were present within membrane‐bound vacuoles in the cytoplasm of mouse‐decidual cells on the 7th day of pregnancy. The space between the vacuole membranes and the fibrils was narrow and frequently filled with a granular electron‐dense material. The loss of banding of the collagen fibrils, their association with lysosomelike bodies, and the demonstration of acid phosphatase activity in the vacuoles indicate that the fibrils were internalized by the decidual cells and were being digested. It is suggested that phagocytosis of collagen is a mechanism of remodeling of the mouse decidua.
Study of the functional anatomy of bovine cervical mucosa with special reference to mucus secretion and sperm transport
Authors: June Mullins K. , Saacke R. G.
Published: February 2005

The bovine cervical mucosa was investigated with respect to structure, mucus secretory pattern, and sperm transport. Structural investigation included stereomicroscopic examination of surface‐stained tissue blocks and graphic reconstruction of serial sections by using both computer‐generated and Plexiglas models. Histochemistry of the mucosa was evaluated in follicular‐and luteal‐phase animals. Alcian blue, periodic acid Schiff, and high‐iron diamine were utilized to distinguish sialomucins, sulfomucins, and neutral mucins. Location and orientation of cervical sperm in follicular phase animals were evaluated 12 h postmating by using light and electron microscopy. Cervical mucosa was characterized by longitudinal primary folds, most of which maintained continuity throughout the cervix. Superimposed on these were secondary folds which varied in length and depth. Abundant, shallow, uniformly spaced, and parallel longitudinal “grooves” covered all surfaces. Grooves had greater continuity in regions distal, as opposed to proximal, to the cervical canal. Blind‐ending glands or crypts were not apparent. Follicular‐stage cervices exhibited a pronounced sialomucin production in basal areas within grooves while neutral and sulfomucins were predominant in apical areas. In luteal‐phase animals, basal sialomicin production was markedly decreased while sulfated and neutral mucins remained abundant. Numerous cranially oriented spermatozoa were observed within the shallow grooves of cervical folds (sialomucin‐rich areas) in mated animals and were unidirectionally opposed to ciliary beat. It appeared that privileged paths for transport of viable spermatozoa may originate in the fornix vagina, extend through longitudinal primary folds at the external os, and progress to the uterus within continuous sialomucin‐rich channels which are associated with basal areas of the shallow grooves, distal to the cervical canal.
Long‐term effects of gustatory neurectomy on fungiform papillae in the young rat
Authors: Ganchrow Judith R. , Ganchrow Donald
Published: February 2005

Recent evidence from mature hamster fungiform papillae indicates that following denervation taste buds are present from 21 to 330 days in the absence of discernible intragemmal nerve fibers. In contrast, most prior taste bud degeneration studies focused on shorter survival times. The present inquiry in young rats examined the issue of postneurectomy buds, in which regeneration of the resected chorda tympani or facial nerves was prevented and anterior tongue tissue examined over a range of relatively long survival times (30–90 days). Conditions for observing potential taste buds used three histologic stains and a definition of the taste bud not necessarily requiring pore identification.

In each case, serial section examination of the anterior‐most 2–3 mm of lingual epithelium revealed 29–56 bud‐containing fungiform papillae on the unoperated side. In contrast, ipsilateral to the neurectomy, only zero‐7 medially‐placed, mature‐looking buds were observed per case, as well as zero‐3 more laterally situated fungiform papillae containing small clusters of cells in basal epithelium that lacked the vertical organization and cytoplasmic staining intensity of mature taste buds. These cell aggregates were distributed evenly across survival time and stain used.

Therefore, in young rats following gustatory neurectomy, longer survival times, per se, would not appear to be a prerequisite for sustaining fungiform taste buds. The appearance of “midline” buds postsurgery may be attributed to either normal contralateral or a net bilateral innervation, and/or ipsilateral denervation and bud loss inducing neural sprouting from the contralateral side.
Immunohistochemical evidence for the presence of neuropeptides in the hypothalamic suprachiasmatic nucleus of ground squirrels
Authors: Reuss Stefan , Hurlbut Edward C. , Speh Joan C. , Moore Robert Y.
Published: February 2005

The cytoarchitecture and immunocytochemical distribution of neuropeptides (corticotropin‐releasing factor, CRF; neuropeptide Y, NPY; oxytocin, OXY; vasopressin, VP; and vasoactive intestinal polypeptide, VIP) were studied in the hypothalamic suprachiasmatic nuclei (SCN) in male and female ground squirrels of two species (Spermophilus tridecemlineatus and S. richardsonii).

Immunoreactive (IR) perikarya were found in sections incubated with VP or VIP antisera. VP‐IR cell bodies were seen in the dorsal and medial parts of the nucleus in colchicine‐treated animals. IR fibers were distributed thoughout the SCN. In the ventral part of the nucleus, VIP‐IR cells were seen in untreated animals and were more pronounced in colchicine‐treated animals. VIP‐IR fibers and terminals form a dense plexus throughout the nucleus. Furthermore, NPY‐IR terminals and fibers with multiple varicosities, but no IR perikarya, were present in the suprachiasmatic nuclei. Within the borders of the SCN, no cell bodies or fibers were stained with CRF or OXY antisera in any animal.
Epicardial development in the axolotl, ambystoma mexicanum
Authors: Fransen Margaret E. , Lemanski Larry F.
Published: February 2005

Recent studies on avian and mammalian embryos have established that the epicardium is derived, not from the early heart tube, but from mesothelial tissue overlying the sinus venosus. We tested the validity of this concept for Amphibia by examining normal and cardiac lethal (c/c) mutant axolotl embryos (stages 35‐43) by electron microscopy.

In axolotl embryos, the myocardial surface of the heart remains exposed to the pericardial fluid through stage 39. At this stage the transverse septum releases into the pericardial cavity mesothelial cells that subsequently flatten over the adjacent ventricular myocardium. However, mesothelial cells observed on the developing epicardium always appear rounded and may extend a filopodium up to 75 m̈m. This apparent “substrate‐dependent” difference in mesothelial cell shape may promote the extension of the epicardium over the rest of the myocardium. The initial site of epicardial formation persists in the adult as the ventricular pericardial stalk that connects the epicardium to the peritoneal lining of the transverse septum.

Cardiac lethal (c/c) mutant embryos, despite the non‐contractility of their myocardia, form their epicardia in the same way. This suggests that the c/c mutation does not impair those properties of the myocardium that render it a suitable substrate for epicardial spreading. The abnormal pattern of epicardial coverage of the edematous stage 41 c/c mutant heart could be the result of its abnormally large myocardial surface area, the abnormal proximity of the atrium to the transverse septum, and/or the absence of heart contractions which could aid the dispersion of mesothelial cells within the pericardial cavity.

Despite species differences, epicardial development in the axolotl is similar to the general pattern described for higher vertebrate embryos.
Morphometric study of the microvasculature of the main excretory duct subepithelia of the rat parotid, submandibular and sublingual salivary glands
Authors: Sato Atsuko , Miyoshi Sakuichiro
Published: February 2005

This study investigated the relationship between the fine structure of the main excretory duct (MED) epithelia and the subepithelial capillaries of the major salivary glands (parotid, submandibular, and sublingual) in the rat. The MED subepithelial capillaries vary in type (fenestrated and continuous), number of fenestrae present in the available fenestrated endothelium (the attenuated area of endothelium), and number of capillaries per unit length of epithelium.

In the parotid gland, continuous capillaries predominate, and the capillary density per 200 μm of epithelium (1.73 in region I and 1.03 in region II) is lower than in the other two glands, as is the number of fenestrae per 10 μm of available endothelium (1.97 in region I and 1.25 in region II). The submandibular gland has mainly fenestrated capillaries. The capillary density per 200 μm of epithelium (4.46 in region I and 5.51 in region II) is higher than in the other two glands, as is the number of fenestrae per 10 μm of available endothelium (4.82 in region I and 7.90 in region II). Similarly, in the sublingual gland, fenestrated capillaries are dominant. The density of capillaries per 200 μm of epithelium (4.15 in region I and 4.31 in region II) is intermediate between the parotid and submandibular glands, as is the number of fenestrae per 10 μm of available endothelium (2.98 in region I and 3.83 in region II).