bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accumulation and localization of two adult acinar cell secretory proteins during development of the rat submandibular gland
Authors: Moreira Jorge E. , Ball William D. , Mirels Lily , Hand Arthur R. 
Published: February 2005

AbstractThe seromucous acinar cells of the adult rat submandibular gland secrete a characteristic mucin glycoprotein and a family of unusual glutamine/glutamic acid‐rich proteins (GRP). Monoclonal antibodies to the mucin and GRP localized in a very few Type III cells in glands of newborn and 1 day‐old rats, using light and electron microscopic immunocytochemistry. Both mucin and GRP reactivities were present in the polymorphic Type IIIP granules during the 1st postnatal week. By 9 days after birth, the granules contained both mucin and GRP and were mucous‐like in appearance. At earlier stages, however, cells containing only GRP or mucin could be found, indicating that the initiation of GRP and mucin biosynthesis may not be coordinately regulated. No reactivity was seen in the neonatal Type I cells or in duct cells at any age. Northern and Western blot analysis showed GRP mRNA and protein levels to be barely detectable at birth, with marked increases during the first 2 postnatal weeks. In contrast, Western blots of B1‐immunoreactive proteins (B1‐IP) showed levels highest in the 1st week and markedly decreased in the adult. Immunocytochemical colocalization, using gold particles of different sizes, showed that the B1‐IP, mucin, and GRP colocalized in the granules. These results strengthen the hypothesis that the adult acinar cells develop from the neonatal Type III cells. No evidence was obtained for the involvement of Type I cells in the pathway of acinar cell development.
Development of the discodial hemochorial placenta in the black mastiff bat, Molossus ater: Evidence for a role of maternal endothelial cells in the control of trophoblastic growth
Authors: Rasweiler John J. 
Published: February 2005

AbstractIn an effort to define further the factors that can influence trophoblastic growth, development of the discoidal chorioallantoic placenta was examined histologically in laboratorybred black mastiff bats, Molossus ater. This placenta normally forms only at the cranial end of the right uterine horn. Its positioning was found to be related to the development of an unusual vascular tuft in the endometrium at this site following ovulation. When a decidual reaction occurred, the endothelial cells of the tuft vessels hypertrophied and their basal laminae became more prominent in sections stained for glycoproteins. Cytotrophoblast then proliferated preferentially around the tuft in the right horn and its vessels became surrounded by trophoblastic cuffs. A functional placenta was formed when trophoblastic tubules grew out from these cuffs, became interconnected, developed lumina, and began to carry maternal blood. Maternal endothelial cells generally persisted only in portions of the larger vascular tubules.These observations suggest that the endothelial cells of the tuft vessels may be secreting factors that influence early trophoblastic growth and are at least partially incorporated into the basal laminae of the endothelial cells. Evidence is reviewed which raises the possibility that endometrial endothelial cells might have a similar morphogenetic role in many other mammals with invasive trophoblast.Mitotic activity in the trophoblastic tubules of M. ater ceased when the tubules became patent and began to carry blood. Further growth was then accomplished by hypertrophy of the existing cytotrophoblast cells. Electron microscopic examination of near‐term placentas confirmed that the interhemal barrier was hemomonochorial and lacked a continous layer of syncytiotrophoblast.
Changes in ultrastructure of transport systems and in rates of progestin secretion in the corpus luteum during late pregnancy in the rat
Authors: Dharmarajan A. M. , Bruce Neville W. , Waddell Brendan J. 
Published: February 2005

AbstractMorphometric studies have confirmed that the corpus leteum (CL) of the pregnant rat contains luteal cells with numerous microvilli which directly face an extensive network of sinusoidal capillaries. From this it has been suggested that extensive development of transport structures is necessary to support progesterone synthesis and secretion. The present study was carried out to determine whether these transport structures could be related quantitatively to different rates of total progestin (progesterone plus 20 α‐hydroxypregn‐4‐en‐3‐one) secretion reported to be 32, 10, and 23 μg/hr per ovary on day 16 and the morning (AM) and afternoon (PM) of day 22, respectively.Histological analysis was carried out on two CL, fixed by immersion, from each of five rats, at each stage of gestation. The important findings to emerge were that when the progestin secretion rate was greater, there was a significant increase in surface specializations on the lutelal cell and a thickening of the capillary walls. There was also a greater volume of interstitial space between luteal cells and capillaries. However, due to the development of microvilli and unevenness in the capillary wall, the physiological diffusion distance (harmonic distance) between luteal cell cytoplasm and blood was not increased. Collectively, these results show that changes in the rate of progestin secretion are accompanied by significant, although disproportionate, changes in transport structures and suggest that the latter are important in supporting luteal function.
Initial migration and distribution of the cardiac neural crest in the avian embryo: An introduction to the concept of the circumpharyngeal crest
Authors: Kuratani Shigeru C. , Kirby Margaret L. 
Published: February 2005

AbstractThe distribution and migration of the cardiac neural crest was studied in chick embryos from stages 11 to 17 that were immunochemically stained in whole‐mount and sectioned specimens with a monoclonal antibody, HNK‐1. The following results were obtained: (1) The first phase of the migration in the cardiac crest follows the dorsolateral pathway beneath the ectoderm. (2) In the first site of arrest, the cardiac crest forms a longitudinal mass of neural‐crest cells, called in the present study, the circumpharyngeal crest; this mass is located dorsolateral to the dorsal edge of the pericardium (pericardial dorsal horn) where splanchic and somatic lateral mesoderm meet. (3) A distinctive strand of neural‐crest cells, called the anterior tract, arises from the mid‐otic level and ends in the circumpharyngeal crest. (4) By stage 16, after the degeneration of the first somite, another strand of neural‐crest cells, called the posterior tract, appears dorsal to the circumpharyngeal crest. It forms an arch‐like pathway along the anterior border of the second somite. (5) The seeding of the pharyngeal ectomesenchyme takes place before the formation of pharyngeal arches in the postotic area, i.e., the crest cells are seeded into the lateral body wall ventrally from the circumpharyngeal crest; and, by the ventralward regression of the pericardial dorsal horn, lateral expansion of pharyngeal pouch, and caudal regression of the pericardium, the crest cell population is pushed away by the pharyngeal pouch. Thus the pharyngeal arch ectomesenchyme is segregated. (6) By stage 14, at the occipital somite level, ventrolateral migration of the neural crest is observed within the anterior half of each somite. Some of these crest cells are continuos with the caudal portion of the circumpharyngeal crest. An early contribution to the enteric neuroblasts is apparent in this area.
Ultrastructural localization of Tartrate‐resistant acid phosphatase (purple acid phosphatase) activity in chicken cartilage and bone
Authors: Fukushima Osamu , Bekker Petrus J. , Gay Carol V. 
Published: February 2005

AbstractTartrate‐resistant acid adenosine triphosphatase activity at pH 6.5, using a lead‐salt method, was localized at light and electron microscopic levels in cartilage and bone matrices, osteocalsts, and chondrocalsts. Cartilage matrix staining occurred after vascular invasion of the growth plate. In osteoclasts, activity was present in lysosomes, extracellular ruffled border channels, and the underlying cartilage and bone matrices. Staining artifacts occurred at lower pH levels (pH 5.4, 5.0).Adenosine diphosphate, p‐nitrophenylphosphate, thiamine pyrophosphate, and α‐naphthylphosphate also acted as substrates; but no activity was observed when adenosine monophosphate, adenylate‐(β,γ‐methylene) diphosphate, and β‐glycerophosphate were used. The activity was inhibited by NaF, dithionite, and a high concentration of p‐chloromercuribenzoic acid, and activated by simultaneous addition of FeCl2 and ascorbic acid, as has been shown in biochemical studies. These histochemical results support the view that the adenosine triphosphate hydrolyzing activity at pH 6.5 is due to tartrate‐resistant acid phosphatase (TRAP).There were some differences in ultrastructural localization between TRAP and tartrate‐sensitive acid phosphatase (TSAP) activities in osteoclasts: TSAP activity was more intense in lysosomes and Golgi complexes and TRAP was stronger in the cartilage and bone matrices. It is suggested, therefore, that most of TRAP is in an inactive form in cells and is activated when secreted.
Ontogeny of reticular cells in the ileal Peyer's patch of sheep and goats
Authors: Nicander L. , Halleraker M. , Landsverk T. 
Published: February 2005

AbstractThe ontogeny of reticular cells in the ileal Peyer's patch of sheep from 70 days gestational age was studied by light and electron microscopy and by enzyme histochemistry. Small to medium‐sized lymphocytes were seen in the lamina propria at 97 days, when the stroma was essentially still mesenchymal. By 110 days, the stromal cells in the dome/follicle primordia had differentiated into reticular fibroblasts, whose processes and fibers were seen to surround groups of lymphocytes. With advancing age the number and size of primordia increased, and proliferation was obvious among the lymphocytes. Processes of reticular cells increased in number and penetrated between individual lymphocytes of the groups. Coarser desmosome‐like contacts were seen between the reticular cells from 115 days onwards. A central light area in the follicle was apparent from 130 days onwards. The fine structure of the stromal cells in this light follicle center developed towards but never became similar to that of follicular dendritic cells in a typical germinal center. The fine interdigitating end branches of the stromal cells were less numerous, and the dense homogeneous material present in between the end branches was not observed in the ileal Peyer's patch follicle. Instead, small particles and vesicles were seen between the various cell types of the light center and were not restricted to the intercellular spaces between the stromal cells. In the dark peripheral zone of the follicle, the stromal cells retained more immature features. The follicle became bordered by a capsule at an early stage. This capsule was formed by multiple layers of flattened fibroblasts separated by small amounts of intercellular material only. The alkaline phosphatase, Mg2+‐dependent adenosine triphosphatase and 5′nucleotidase reactivities of the follicular dendritic cells in the ileal Peyer's patch were similar to those of early prenatal primary follicles of sheep lymph nodes. This study indicates that the stromal cells of the ileal Peyer's patch are mesenchymal in nature and different from those of germinal centers and the epithelial stromal cells of bursa Fabricii of birds. © 1991 Wiley‐Liss, INC.
Organization of tubules in the human caput epididymidis and the ultrastructure of their epithelia
Authors: Yeung C. H. , Cooper T. G. , Bergmann M. , Schulze H. 
Published: February 2005

AbstractThe structure of the human caput epididymidis was examined by gross morphological and light and electron microscopic techniques. There were at least seven types of tubules, each characterized by a different epithelium. These tubules were connected with one another by at least eight types of junctions to form a network. Most of the caput epididymidis was composed of efferent ducts. Within these, five types of tubules, each with a different ciliated epithelium, were found in different regions; and four types of junctions between the efferent ducts and the epididymal tubule were observed. The efferent ducts left the testis, initially as parallel straight tubules containing both ciliated and non‐ciliated cells in an epithelium of irregular height. Each efferent duct then coiled tortuously into lobules that folded over one another. These efferent ducts then branched out as thin tubules to join a network of dark tubules which were lined by a regular epithelium containing prominently vacuolated, nonciliated cells. These tubules anastomosed via common cavities characterized by a ciliated cuboidal epithelium and sometimes joined tubules exhibiting a non‐vacuolated ciliated epithelium. The latter, as well as typical efferent ducts, made connection with the epididymis proper in both end‐to‐end and end‐to‐side junctions. In the more distal junctions with the epididymis, the efferent ducts joined to a transitional epididymal ductule before joining to the side of the epididymis proper. Post‐junctional epithelia in the beginning of the epididymis occasionally contained patches of cells characteristic of efferent ducts. Tall cells with long stereocilia constituted a discontinuous “initial segment”‐like region of the epididymis. This is the most detailed study so far of the epithelia and the tubule organization in the caput epididymidis of any species, and most of the results are reported for the first time for the human. Although the pattern of the tubule network resembles that of some domestic species, the rich variety of epithelia has not been appreciated before.
Spatial and temporal patterns of muscle cleavage in the chick thigh and their value as criteria for homology
Authors: Schroeter Sally , Tosney Kathryn W. 
Published: February 2005

AbstractRegions of lower cell density, called cleavage zones, emerge within the dorsal and ventral muscle masses in the vertebrate limb to separate distinct muscles. In the chick thigh, the stereotyped patterns of separation have been broadly outlined, but differences in interpretation exist because no criteria for separation have been defined, and the tissues of the limb are indistinct early in development. We have examined the cleavage process using modern applications of light microscopy and immunocytochemistry to completely detail the spatial and temporal progression of cleavage in stage 27–32 embryos. We find that each muscle has a complex but characteristic pattern of separation along the proximodistal axis. The complex pattern of separation is not related to the positions of muscles within the thigh, locations of blood vessels, activity patterns of muscles, or innervation patterns. The initial separation patterns are more straightforward than later separations and may be of value in determining the phylogenetic history of limb muscles since the same patterns are common to many tetrapods. Our detailed documentation clarifies the ontogeny of the thigh musculature and reveals more complex separation patterns between muscles than previously described.
An immunocytochemical study of cutaneous innervation and the distribution of neuropeptides and protein gene product 9.5 in man and commonly employed laboratory animals
Authors: Karanth S. S. , Springall D. R. , Kuhn D. M. , Levene M. M. , Polak J. M. 
Published: February 2005

AbstractThe cutaneous nerves of rat, cat, guinea pig, pig, and man were studied by immunocytochemistry to compare the staining potency of general neural markers and to investigate the density of nerves containing peptides. Antiserum to protein gene product 9.5 (PGP 9.5) stained more nerves than antisera to neurofilaments, neuronspecific enolase (NSE), and synaptophysin or histochemistry for acetylcholinesterase (AChE). Peptidergic axons showed species variation in density of distribution and were most abundant in pig and fewest in man. However, the specific peptides in nerves innervating the various structures were consistent between species. Nerve fibers immunoreactive for calcitonin gene‐related peptide (CGRP) and/or vasoactive intestinal polypeptide (VIP) predominated in all the species; those immunoreactive to tachykinins (substance P and neurokinin A [NKA]) and neuropeptide tyrosine (NPY) were less abundant. Neonatal capsaicin, at the doses employed in this study, destroyed approximately 70% of CGRP‐ and tachykinin‐immunoreactive sensory axons; whereas 6‐hydroxydopamine (6‐OHDA) at the doses employed resulted in a complete loss of NPY and tyrosine hydroxylase (TH) immunoreactivity without affecting VIP, CGRP, and tachykinins.Thus, this study confirms that antiserum to PGP 9.5 is the most suitable and practical marker for the demonstration of cutaneous nerves. Species differences exist in the density of peptidergic innervation, but apparently not for specific peptides. Not all sensory axons immunoreactive for CGRP and substance P/NKA are capsaicin‐sensitive. However, all sympathetic TH‐ and NPY‐ immunoreactive axons are totally responsive to 6‐OHDA; but no change was seen in VIP‐immunoreactive axons, suggesting some demarcation of cutaneous adrenergic and cholinergic sympathetic fibers.
Histometry of normal thyroid glands in neonatal and adult rats
Authors: Conde E. , Martin‐Lacave I. , Gonzalez‐Campora R. , Galera‐Davidson H. 
Published: February 2005

AbstractThe present histometric study is on thyroid glands of Wistar rats ranging in age from 0 to 120 days. The mean volume of one lobe of the thyroid in 4‐month‐old animals was some 22‐, 10‐, 5‐, and 3‐fold greater, respectively, than the volumes in the newborn, 5‐, 10‐, and 30‐day‐old rats. At 4 months of age the mean length of the lobe was 3 times greater than at birth. The volumetric fractions (Vv) of the different histological components (follicular cells, C‐cells, colloid, and interstitial tissue) changed considerably in the course of development. The Vv of follicular cells diminished from 61.4% at birth to 37.2% at 4 months. C‐cells increased from 2.9% in the newborn to 4% at 15 days, with no further significant change at 4 months. Colloid and stroma together represented 35.7% at birth, increasing to 58.5% at 120 days. In the course of the first 4 months of life, the absolute volumes occupied by follicular cells, C‐cells, colloid, and stroma increased 13.25, 30.75, 38.6, and 33.7 times, respectively; these changes reflect the variations that occur in the volume of the gland and the Vv throughout postnatal development.
Comparative morphology and morphometry of alveolar macrophages from six species
Authors: Haley P. J. , Muggenburg B. A. , Weissman D. N. , Bice D. E. 
Published: February 2005

AbstractPulmonary alveolar macrophages (PAM) were collected from normal, healthy mice, rats, dogs, cynomolgus monkeys, chimpanzees, and humans and evaluated for morphologic and morphometric characteristics. The PAM of mice, rats, and dogs were morphologically similar and had statistically similar frequency distributions for size. The cell size distribution or these three species was relatively homogeneous. The PAM of nonhuman primates and humans were morphologically heterogenous with sometimes prominent cytoplasmic vacuolation, irregular cell outlines, and increased numbers of multinucleated cells as compared to the PAM of rodents and dogs. The mean size of human PAM was statistically greater than that for all other species evaluated, including nonhuman primates. These data indicate that significant differences in PAM morphology and size exist among species.
A quantitative evaluation of Fourier components in transparent and opaque calf cornea
Authors: Gisselberg Margo , Clark John I. , Vaezy Shahram , Osgood Thomas B. 
Published: February 2005

AbstractFourier transform methods were applied to STEM (scanning transmission electron microscopy) images to detect and quantify the subtle differences between the structure of normal transparent calf cornea and opaque calf cornea. In order for a tissue to be transparent, it can scatter or absorb only a small amount of light. Light scattering is minimized when the principal Fourier components of the spatial fluctuations in the index of refraction have wavelengths which are small relative to the wavelength of light (Benedek, 1971). Corneal opacity was produced as a result of high intraocular pressure (100–150 mmHg) when liquid was injected into calf eyes (0–2 weeks old). Pressurization created large structural defects and slight disruptions in the organization of the collagen fibers. Although the fiber organization appeared similar in the micrographs of both opaque and transparent corneas, Fourier analysis of STEM images collected at 50K magnification identified statistically significant differences. Far fewer Fourier components with wavelengths in the light scattering range (200–1100 nm) were observed in the transparent corneas than in the pressurized corneas as predicted by Benedek's theory. It was of interest that corneas treated with 100% glycerol prior to pressurization remained transparent at high intraocular pressures, possibly because glycerol stabilized the structure of the corneas and maintained a uniform index of refraction across the corneal stroma. The results demonstrate the effectiveness of Fourier analysis in detection and quantification of slight changes in structure at the electron microscopic level.
Epidermal ridge formation in the human fetus: A correlation to the appearance of basal cell heterogeneity and the expression of epidermal growth factor receptor and cytokeratin polypeptides in the epidermis
Authors: Misumi Yuko , Akiyoshi Toshio 
Published: February 2005

AbstractThis paper aims to clarify an expression of epidermal growth factor receptor (EGFR) and cytokeratin 10 and/or 11 in relation to primary and secondary epidermal ridge formation of the human fetus.Firstly, scanning electron microscopy revealed heterogeneity in basal cell morphology during epidermal ridge formation. Basal cells had a uniform, smooth, and polygonal dermal surface until formation of the primary epidermal ridges. Thereafter, the dermal surface became ruffled and elliptic except at the primary epidermal ridges.Secondly, EGFR was detected by monoclonal antibody and autoradiography using 125I‐EGF. The antibody reacted with primary epidermal ridge, stratum basale, stratum intermedium, and outer layer of sweat duct. The reactivity became stronger at the primary epidermal ridge than at the secondary one. The binding of 125I‐EGF was concentrated in the primary epidermal ridge and sweat duct.Thirdly, cytokeratin 10 and/or 11, a maturation marker of keratinocytes, was detected by monoclonal antibody. The antibody reacted only with the stratum intermedium before secondary epidermal ridge formation. Afterward, it also reacted with the stratum basale of the secondary epidermal ridge but never reacted with that of primary epidermal ridge.The results indicate that basal cells of the secondary epidermal ridge enter the maturation process and suggest a localization of epidermal stem cells on the primary epidermal ridges. Concerning epidermal ridge formation, we suppose that the formation of the primary epidermal ridge causes the segregation of the epidermal stem cells, and that the increased density of the basal cells between the two primary epidermal ridges brings about the change in their dermal surface shape and the formation of the secondary epidermal ridge.