bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphological characterization of a granulocytosis/hypercalcemia‐inducing murine mammary carcinoma cell line
Authors: Riddle Clara V. , Lee Minako Y. , Lee Ming J. 
Published: February 2005

AbstractA newly established cell line of a granulocytosis/hypercalcemiainducing murine mammary carcinoma (CE mammary carcinoma) grown in serum‐free culture medium secretes factors that stimulate proliferation of granulocytes and embryonal bone cells. These cultured cells retain the ability to produce granulocytosis and hypercalcemia when they are transplanted back into mice. In culture these cells form clusters of organized cells. Studies by scanning, transmission, and freeze‐fracture electron microscope techniques reveal that these in vitro tumor cells retain the structural epithelial characteristics of mammary epithelia. They maintain cellular polarity, microvilli, and complete tight junctions. Both the in vivo and in vitro tumor cells produce viral particles with the ultrastructural features of murine mammary tumor viruses. In both in vivo and in vitro conditions, A‐type particles are present intracellularly. B viral particles are present predominantly in the intercellular spaces. Since the structural characteristics of the cultured tumor cells are consistent with the features of mammary adenocarcinomas, this is a prime culture system for studying the tumor‐derived soluble factors.
Development of adipose tissues
Authors: Nnodim Joseph O. 
Published: February 2005

AbstractStudies on the development of brown and white adipose: tissues and their relationship to ordinary connective tissue are the subject of the present review, which is updated to the fall of 1985. Primordial entities described as “primitive organs” have been noted at sites of adipose tissue development by numerous investigators. These “primitive organs” are clearly delineated from surrounding connective tissue and possess a well‐defined vascular network in the interstices of which cellular organization takes place.The precursor cells of brown and white adipocytes appear to acquire their distinctive cytogenetic properties at a very early stage in the embryo. These progenitor cells temporarily exhibit structural similarities to fibroblasts and endothelial cells. This resemblance has led to speculation that fibroblasts and/or endothelial cells may be ancestral to adipocytes. However, recent in vivo and in vitro observations suggest that the brown adipose precursor cell is morphogenetically distinct from the white adipose precursor cell on one hand, and from fibroblasts and endothelial cells on the other.In vitro studies have also shown that the pericytic elements present in both brown and white adipose tissue depots in the adult are quiescent precursor cells that may be recruited under certain circumstances. Areas for further inquiry by means of recently developed techniques are indicated.
A reexamination of the role of microfilaments in neurulation in the chick embryo
Authors: Schoenwolf Gary C. , Folsom David , Moe Ardis 
Published: February 2005

AbstractFormation of wedge‐shaped neuroepithelial cells, owing to the constriction of apical bands of microfilaments, is widely believed to play a major part in bending of the neural plate. Although cell “wedging” occurs during neurulation, its exact role in bending is unknown. Likewise, although microfilament bands occupy the apices of neuroepithelial cells, whether these structures are required for cell wedging is unknown. Finally, although it is known that cytochalasins interfere with neurulation, it is unknown whether they block shaping or furrowing of the neural plate, or elevation, convergence, or fusion of the neural folds. The purpose of this study was to reexamine the role of microfilaments in neurulation in the chick embryo. Embryos were treated with cytochalasin D (CD) to depolymerize microfilaments and were analyzed 4–24 hr later. CD did not prevent neural plate shaping, median neural plate furrowing, wedging of median neuroepithelial cells, or neural fold elevation. However, dorsolateral neural plate furrowing, wedging of dorsolateral neuroepithelial cells, and convergence of the neural folds were blocked frequently by CD. In addition, neural folds always failed to fuse across the midline in embryos treated with CD, and neural crest cell migration was prevented. These data indicate that only the later aspects of neurulation may require microfilaments, and that certain neuroepithelial cells, particularly those that normally wedge with median furrowing and elevation of the neural folds, become (and remain) wedge‐shaped in the absence of apical microfilament bands. Thus, microfilament‐mediated constriction of neuroepithelial cell apices is not the major force for median neuroepithelial cell wedging and elevation of the chick neural plate. Further studies are needed to localize the motor(s) for these processes.
The anionic matrix at the rat glomerular endothelial surface
Authors: Avasthi Pratap S. , Koshy Valsala 
Published: February 2005

AbstractThe anionic macromolecules at the glomerular endothelial cell surface are visualized only when stained with cationic stains. We investigated the arrangement and composition of this anionic matrix at the luminal surface. Rat kidneys were perfused with anionic ferritin (pI 4.5), ferritin (pI 7.4), or cationized ferritin (CF, pI 8.3). Anionic ferritin (pI 4.5) did not bind to the capillary wall, ferritin (pI 7.4) bound discontinuously only to the laminae rarae of the basement membrane, but cationized ferritin (CF, pI 8.3) bound as a thick continuous layer to the cell plasmalemma and bound to the anionic matrix in the fenestral spaces. These observations show that an anionic matrix lines the entire capillary lumen surface, fills the fenestrae, and is interposed between the blood and the basement membrane at the fenestrae.The anionic constituents at the capillary luminal surface were identified by in vivo digestion with specific enzymes. Absence of CF binding following digestion with specific enzymes was taken to indicate the presence of the particular glycoprotein known to be susceptible to the enzyme used. Neuraminidase digestion revealed that anionic sites over the surface plasmalemma are mainly from sialoproteins. In contrast, the matrix in fenestral channels contains heparan sulfate, hyaluronic acid, and sialoproteins. Papain digestion showed no glycolipids at the luminal surface. The functions of this continuous anionic layer located at the luminal surface of glomerular capillaries have not yet been established.
Ultracytochemical localization of adenylate cyclase in early human placenta
Authors: Spreca Antonio , Rambotti Maria Grazia , Ferrarese Remo , Pomili Giovanni , Angelini Antonio 
Published: February 2005

AbstractA cytochemical study was carried out on adenylate cyclase (AC) activity in the early human placenta. Samples of placental villi were incubated in a medium containing adenylyl‐imidodiphosphate (AMP‐PNP) as specific substrate. No AC reaction product was encountered in placenta villi taken at 5 and 7 weeks of pregnancy. AC activity appeared at 9 weeks. At 9 and 10 weeks, AC reaction product was localized on the basal plasma membranes and on apposed plasma membranes of the Langhans cytotrophoblast. At 11 weeks AC activity was also clearly visible on Langhans cytotrophoblast and syncytiotrophoblast apposed plasma membranes. No AC reaction product was ever detected on the syncytiotrophoblast microvillar membrane. These results are in agreement with biochemical studies that localize AC on the villous trophoblast plasma membranes associated with the fetal circulation.
Morphometry of the human pulmonary acinus
Authors: Haefeli‐Bleuer Beatrice , Weibel Ewald R. 
Published: February 2005

AbstractThe geometry and morphometry of intraacinar airways in human lungs were studied on silicone rubber casts from two adult lungs. We defined acini as the complex of alveolated airways distal to the terminal bronchioles—that is, beginning with the first‐order respiratory or transitional bronchiole. The morphological properties of pulmonary acini are described. The acinar volume averages 187 mm3 (SD ± 79 mm3). Intraacinar airways branch dichotomously over about 9 generations (range 6–12). The internal airway diameter falls from 500 μm to 270 μm between acinar generations 0 and 10, whereas the outer diameter (including the sleeve of alveoli) remains constant at 700 μm. Towards the periphery the size of alveoli increases and clusters of alveoli become more numerous. The longitudinal path length of acinar airways (defined as the distance along the ducts from the transitional bronchiole to the alveolar sacs) averages 8.8 mm (± 1.4 mm). The morphometric data collected in this study are used to construct an idealized model of human acinar airways that can be related to existing models of the human bronchial tree.
Localization of inhibin in human testes by immunoperoxidase technique
Authors: Garde Seema V. , Moodbidri Shdhir B. , Phadke Achyut M. , Sheth Anil R. 
Published: February 2005

AbstractImmunohistological studies on the localization of inhibin in human testes were carried out to investigate the cell types involved in inhibin synthesis/storage. The paraffin embedded testicular tissues were stained by an indirect immunoperoxidase technique. Specific antiserum to human testicular inhibin generated against the homogenous preparation of human testicular inhibin at our laboratory was used as the first antibody. Inhibin was found to be localized in Sertoli cells, spermatogonia, and primary spermatocytes. A weak positive reaction was also observed in spermatids. Interestingly, Leyding cells showed positive reaction indicating presence of inhibin in these cells too.
Trajectory architecture of the trabecular bone between the body and the neural arch in human vertebrae
Authors: Pal Gaya P. , Cosio Leo , Routal Rohini V. 
Published: February 2005

AbstractThe cancellous structure of vertebrae has been studied to investigate the direction of trabeculae and thus the lines of stress. The trabecular bone of the pedicle, connecting the body to the lamina, differed in different regions of the vertebral column. At C2 level, it was found that trabeculae are involved in transfer of the compressive forces from the superior articular surface to the inferior articular process and body. Throughout the thoracic region, trabeculae in the pedicle were inclined anteriorly towards the body, indicating that compressive forces in the thoracic spine are transferred from the neural arch to the body. In the lower lumbar region, trabeculae run from the body towards the neural arch. Trabeculae in the thoracic transverse proesses extend from the costal facet to the lamina, suggesting that weight brought by the ribs to the costotransverse articulations is transmitted to laminae through transverse processes.A major part of the research was conducted while the first author (G.P.P.) was working as visiting Associate Professor at the Medical College of pennsylvania, Philadelphia, on a fellowship granted by the Educational Commission for Foreign Medical Graduates (E.C.F.M.G.).
Localization of cathepsin B in normal and hyperplastic human prostate by immunoperoxidase and protein A‐gold techniques
Authors: Sinha Akhouri A. , Gleason Donald F. , Limas Catherine , Reddy Pratap K. , Wick Mark R. , Hagen Kimberly A. , Wilson Michael J. 
Published: February 2005

AbstractCathepsin B, a lysosomal cysteine protease, was localized in normal prostate and benign prostatic hyperplasia (BPH) using immunoperoxidase and protein A‐gold techniques. Our objective was to determine whether cathepsin B was involved in the prostatic epithelium affected by nodular hyperplasia. All samples were collected immediately after prostatectomy. Immunohistochemical studies showed that the enzyme was expressed in the supranuclear cytoplasm of columnar cells and in numerous basal cells of normal and BPH acini. The strongest localization of cathepsin B occurred in acinar basal cells; hence, it is possible that cathepsin B could be useful as a marker for such cellular elements. Stromal macrophages showed reaction products, but lymphocytes and neutrophils did not. In both normal and hyperplastic glands, the enzyme was localized by gold particles in lysosomes, secretory granules, and vacuoles of columnar epithelial acinar cells. Immunoelectron microscopic study also showed the presence of cathepsin B in the heterochromatin (condensed chromatin) and nuclear membranes of columnar and basal cells, but not in euchromatin or nucleoli. At present, the function of cathepsin B in the nuclei of basal and columnar cells remains unknown. However, the cathepsin B in the cytoplasmic compartment might be associated with the lysosomal function of the cells. The role of cathepsin B as a marker for basal cell participation in the development of prostatic lesions should be studied further.
Kinetic analysis of thymocyte attachment to thymus stromal cells in culture by using phase‐contrast and scanning electron microscopy
Authors: Larochelle Gregory G. , Jones Kenneth H. 
Published: February 2005

AbstractDirect cellular contact between thymocytes and thymus stromal cells within the thymus appears to contribute to the maturation of thymocytes. Thymocyte‐stromal cell complexes, formed in vivo, have been isolated by others and postulated to play a role in T‐cell differentiation. These previous studies have been hampered, however, by a time‐consuming isolation procedure from which only small numbers of these complexes are recovered. We have examined a model to study thymocyte‐stromal cell complexes in vitro in which thymocytes are added to primary cultures of thymus stromal cells. In the present study, we found that thymocytes were histotypically selective in their attachment to thymus stromal cells. We also investigated the kinetics of thymocyte attachment to these thymus stromal cells. Cultures were examined at selected time intervals from 5 min through 3 days of incubation. Thymocyte attachment to stromal cells was a biphasic interaction, with maximum surface attachment at 15 min of cocultivation, followed by migration of thymocytes into the cultures. Morphological studies were confirmed by using3H‐leucine‐labeled thymocytes and liquid scintigraphy. With increased time in culture, thymocytes became amoeboid and migrated between the layers of stromal cells where thymocyte mitotic figures were seen at 4 and 8 hr. In some cases it appeared that stromal cells, which often grew two to three cell layers deep, played an active role in enclosing thymocytes within the cultures. Large numbers of viable thymocytes were observed in the cultures at 24 hr. The number of thymocytes then decreased progressively on days 2 and 3, when relatively few were found within the layers of the culture.
Regional distribution of fiber types in developing baboon diaphragm muscles
Authors: Maxwell Leo C. , Kuehl Thomas J. , McCarter Roger J. M. , Robotham James L. 
Published: February 2005

AbstractFiber type distribution and mean fiber area were determined for seven sites in diaphragm muscles of premature (140 days gestation), full‐term (180 days gestation), and adult baboons. Within a group, data did not differ significantly amongst the seven sites. The diaphragm of premature animals had a large proportion [56(±2)%] of type IIc fibers, smaller proportions of type I, IIo, and IIh fibers [16(±2), 21(±1), and 7(±2)%, respectively], and no type IIg fibers. Full‐term animals had fewer type IIc [2(±1)%] fibers, greater proportions of type I [46(±2)%], IIh [23(±1)%], and IIg [11(±1)%] fibers, and a similar proportion of type IIo fibers [17(±1)%]. Diaphragm from adult baboons had similar proportions of type I, IIo, IIh, IIg, and IIc fibers in females [39(±4), 20(±2), 1(±1), 41(±5), and 1(±1)%] and males [48(±2), 16(±1), 0(±0), 36(±2), and 3(±2)%]. Fiber area for premature [143(±9), 210(±15), 231(±15), and 156(±16) μm2 for type I, IIo, IIh, and IIc fibers], newborn [317(±32), 374(±36), 468(±42), 498(±43), and 322(±37) μm2 for type I, IIo, IIh, IIg, and IIc fibers], and for type I, IIo, IIg, and IIc fibers from adult female [1,759(±130), 2,365(±284), 5,026(±742), and 1,843(±111) μm2] and adult male [2,513(±221), 3,987(±267), 6,102(±376), and 2,833(±151) μm2] baboons indicated growth which correlated with body weight. Our results also show that metabolic and contractile enzymes develop normally, but growth of respiratory muscle fibers is arrested, during 10 days following premature birth.
High resolution electron microscopy of nonstoichiometric apatite crystals
Authors: Nelson D. G. A. , Barry J. C. 
Published: February 2005

AbstractThe application of high resolution electron microscopy, computer image processing, and image simulation techniques to the investigation of synthetic nonstoichiometric apatites has provided new details of apatite crystal growth mechanisms. Under certain precipitation conditions, calcium‐deficient apatites with distinct octacalcium phosphate (OCP)‐apatite intergrowths have been observed. Apatite crystals with unit‐cell thick overgrowths of OCP on their surfaces confirmed the stepwise hydrolysis crystal growth mechanism initially proposed by Brown (Nature 196:1048–1050). However, many crystals also contained a central two‐dimensional OCP inclusion one to two unit cells thick, embedded in an apatite matrix. Similar planar defects have been observed in dental enamel, dentin, and bone apatite crystals. We have developed a modified version of Brown's stepwise OCP hydrolysis apatite crystal growth mechanism to explain the formation of crystals with OCP central planar defects. The mechanism involves the nucleation of an OCP seed that grows until it reaches a critical size, rh, before OCP hydrolysis occurs. Apatite subsequently grows epitaxially on the OCP seed, thereby embedding it in the center of an apatite crystal. Apatite growth is facilitated by partial screw dislocations emanating from the planar defect.
Insect hemolymph factor promotes muscle histolysis in solenopsis
Authors: Davis Walter L. , Jones Ruth Gwendolyn , Farmer Gene R. 
Published: February 2005

AbstractHemolymph was collected from both normal (virgin) females (control hemolymph) and artificially inseminated females (experimental hemolymph) of Solenopsis, ssp., the imported fire ant (primarily S. invicta and S. geminata). When the control hemolymph was injected into normal females, breakdown of the thoracic flight musculature was not seen 24 hr postinjection. In contrast, when the experimental hemolymph was injected into normal females, flight muscle histolysis was marked 24 hr postinjection. When the experimental hemolymph was heated to 70°C prior to injection into normal females, subsequent flight muscle breakdown was not not seen. The injection of freshly collected semen into normal females produced no effect on flight muscle structure. Also, the injection of the experimental hemolymph into normal, alate males produced no muscle histolysis. These observations suggest that the hemolymph from inseminated females contains a factor (or factors) that induces the specific breakdown and subsequent dissolution of the complex thoracic flight musculature. Other thoracic muscles (leg muscles, intersegmental muscles, etc.) are not affected. Based on observations made in both insect muscles as well as vertebrate skeletal muscles, it is suggested that such a hemolymph factor may act by disrupting the structural integity of muscle cell membranes, resulting in significant changes in membrane permeability, especially with regard to calcium ions.
Annulate lamellae‐soleplate nuclei associations in skeletal muscle fibers of rats during chronic high‐dose exposure to neostigmine
Authors: Kawabuchi Masaru , Osame Mitsuhiro , Aika Yusuke , Kanaseki Takeshi 
Published: February 2005

AbstractTo investigate annulate lamellae (AL) with nuclear changes, ultrastructural time course studies were done of the reversible end‐plate myopathy in the soleus muscles of rats exposed chronically to a high dose of the anticholinesterase drug neostigmine. At the earliest stage (2 hours) in which severe subjunctional damage involving a nuclear lesion (nuclear pyknosis) was prominent, AL profiles were undetectable. At the intermediate stage (7, 21 days), in which the subjunctional organelles tended to cluster and nuclear pyknosis often accompanied degenerative features, most AL laid near the surface of the abnormal nuclei, where there were signs of elimination or formation of pores, as well as a progression of changes leading to the loss of pores. At the late stage (56 days), in which muscle repair was nearly completed and euchromatic nuclei usually were found, there was a concomitant enhanced formation of false nuclear inclusions and of the AL profiles in these sites.Pores are packed on nuclear envelopes, which detach themselves from the nucleus and take the same profile as AL. This phenomenon can be envisioned not only in the euchromatic but also in the abnormal (pyknotic or degenerated) nuclei. Following nuclear reconstitution, the nuclear envelope folding is accelerated to induce the usual pattern of AL organization, i.e., budding from the invaginated nuclear envelope.
Endocardial cell arrangement: Role of hemodynamics
Authors: Icardo Jose M. 
Published: February 2005

AbstractThis paper demonstrates the presence of areas where endocardial cells are aligned with the blood flow in three distinct regions of the embryonic chick heart: on the inferior border of the growing septum primum, on the upper wall of the primitive ventricle above the developing interventricular septum, and on the part of the atrial floor that funnels into the atrioventricular canal. While orientation in the first two areas is transitory, the number of cells aligned with the blood flow in the atrial floor increases from days 3 to 5 of incubation. It is suggested that shear stress induces endocardial cell orientation in these areas. To further explore the role of hemodynamics in endocardial cell arrangement, the left of the vitelline vein was severed at stages 13–14. This resulted in abnormal development of the vitelline venous system. Examination of experimental embryos at 5 days of age revealed the presence of a distinct area of endocardial cell orientation in the dorsal wall of the right atrium, near the opening of the sinus venosus. Changes in the venous return to the atria may modify flow patterns, thus inducing endocardial cell orientation. This experimental procedure may be a useful model not only for exploring the effects of hemodynamics upon the endocardium, but also for investigating other aspects of heart development under altered hemodynamic conditions, without manipulating any portion of the embryonic heart.
Reactivity of rat and rabbit intrafusal fibers with monoclonal antibodies directed against myosin heavy chains
Authors: Maier Alfred , Zak Radovan 
Published: February 2005

AbstractSerial cross and longitudinal sections from the intracapsular portions of intrafusal fibers of rat and rabbit tibialis anterior muscles were examined by fluorescence microscopy with a library of monoclonal antibodies directed against different epitopes on myosin heavy chains. Intrafusal fiber types were identified with the histochemical reactions for acid‐stable and alkali‐stable actomyosin ATPase. Three antibodies, known to react with avian heart and slow‐tonic myosins, produced fluorescent staining in intrafusal fibers. Nuclear bag2 fibers reacted with all three antibodies, chain fibers with two, and nuclear bag1 fibers with only one. These results indicate that in rat and rabbit tibialis anterior muscle spindles nuclear bag2 fibers and chain fibers contain more than one myosin isoform. They also demonstrate that, in addition to the histochemical actomysin ATPase reaction, nuclear chain fibers and the two types of nuclear bag fibers can be identified by the selective reactivities of their myosin heavy chains.