bluuebunny/crossref_metadata_2025_split huggingface dataset:
An analysis of the variations in position of the greater palatine foramen in the adult human skull
Authors: Westmoreland Edwin E. , Blanton Patricia L. 
Published: February 2005

AbstractThree hundred dry, adult human skulls, of East Indian ethnic background, and homogenous in arch form and full eruption of third molars, were examined to measure the location of the greater palatine foramen. The greater palatine foramen was found consistently to lie 1.5 cm from the palatal midline and 0.19 cm from the posterior border of the hard palate. This relationship is suggested as a more accurate method of locating the foramen clinically. The usually accepted description (opposite the second molar) of the relative position of the greater palatine foramen to the upper teeth held in only 9.7% of the skulls studied. This study shows the most common position of the foramen to be opposite or distal to the third molar (57%). The direction of opening of the foramen into the oral cavity was observed to be in an inferior or vertical direction in 247 (82%) of the 300 skulls; in 53 (18%) of the skulls the direction was anterior or horizontal. A bony projection, similar to the mandibular lingula, was observed extending from the posterior margin of the foramen in 95 (16%) of the 600 separate foramina examined. The bilateral symmetry between the sides of the skulls studied was remarkable.
Caudal spinal cord of the teleost Sternarchus albifrons resembles regenerating cord
Authors: Anderson Marilyn J. , Waxman Stephen G. 
Published: February 2005

AbstractThe morphology of spinal cord in the caudal‐most spinal segments of normal adult Sternarchus albifrons is different from that of more rostral adult cord. The caudal segments are strikingly similar to the regenerating spinal cord observed after amputation of the tail in Sternarchus. In the caudal‐most vertebral segment of normal spinal cord, ependymal cells are radially enlarged and are more numerous than in more rostral adult cord. Large processes of the ependymal cells extend into the central canal, which also contains a prominent Reissner's fiber. Invaginations of the outer surface of the spinal cord, with the associated basal lamina, are common. Lateral to the immediate ependymal layer, extracellular spaces contain longitudinally oriented neurites. Cell bodies and cell processes filled with dense‐cored vesicles occur throughout the caudal‐most segment of spinal cord, and are especially concentrated in the ventral half, interspersed with numerous capillaries. In all these respects the caudal‐most segments of normal adult spinal cord in Sternarchus closely resemble regenerating spinal cord of Sternarchus. In both regions, at least some of the ependymal cells retain the ability to divide and generate new neurons and glial cells.
A fine structural and cytochemical study of the rhesus monkey yolk sac: Endoderm and mesothelium
Authors: King Barry F. , Wilson Jean M. 
Published: February 2005

AbstractThis study has examined the fine structure and some cytochemical characteristics of the endodermal and mesothelial cells of the rhesus monkey yolk sac between 25 and 66 days of gestation. The endodermal cells were characterized by abundant granular endoplasmic reticulaum, some agranular endoplasmic reticulum, a well‐developed Golgi apparatus, and numerous large mitochondria. During the earlier part of the period studied, endodermal cells had a few acid phosphatase and arylsulfatase‐positive lysosomes and moderate numbers of catalase‐positive microperoxisomes. During the later stages of development, large granules (believed to be lysosomes) with a heterogeneous content were numerous in the cytoplasm. Mesothelial cells showed fewer development changes. Throughout this period they were usually flattened cells with long microvilli, small mitochondria, and limited amounts of granular endoplasmic reticulum. The mesothelial cells had acid phosphatase reaction product in the Golgi region and occasional large vesicles, but were negative for arylsulfatase and catalase. One specimen was incubated at 37°C in the presence of horseradish peroxidase in order to examine endocytosis. Both the mesothelial cells and endodermal cells internalized the peroxidase into a variety of cytoplasmic vesicles. Based on their cytology, the endodermal cells may function in the synthesis of serum proteins during this period, as has been suggested in other species. They may also be involved in lipid metabolism. The mesothelial cells appeared less synthetically active, but evidence suggested that they may be involved in collagen and extracellular matrix production. The endocytic activity displayed by both cell types may indicate a role in fluid and metabolite transfer across the epithelia. The cytology of both cell types was very similar to that described for human yolk sacs, suggesting that the rhesus monkey may be a useful species in which to study the maturation of yolk sac function.
An ultrastructural study of preovulatory apical development in mouse ovanan follicles: Effects of indomethacin
Authors: Downs Stephen M. , Longo Frank J. 
Published: February 2005

AbstractThe effects of the prostaglandin synthesis inhibitor, indomethacin, on the preovulatory morphology of apical follicle walls have been examind by transmission electron microscopy. Immature mice, superovulated with 5 IU pregnant mare serum (PMS) followed 40 hours later by 80 IU luteinizing hormone (LH) were treated with either 10 mg/kg indomethacin or an equivalent volume of the indomethacin vehicle 10 minutes prior to LH. Follicular apices from both groups were compared at 12 hours post‐LH. Indomethacin treatment suppressed many of the morphological changes normally occurring in the apex during preovulatory development. Whereas apices from vehicle treated animals demonstrated marked deterioration, dissociation, and thinning of tissue, the cell layers of apices from indomethacin‐treated animals remained thickened and tightly packed, with limited signs of disruption. The results presented herein are consistent with the idea that prostaglandins are essential mediators of ovulation and suggest that these lipids augment apical rupture by mobilizing granulosa cells and stimulating the loss of connective tissue elements.
Tracheobronchial epithelium of the sheep: I. Quantitative light‐microscopic study of epithelial cell abundance, and distribution
Authors: Mariassy Andrew T. , Plopper Charles G. 
Published: February 2005

AbstractGlutaraldehyde‐infused tracheas and airways of five castrated sheep were microdissected following the axial airway of the left cranial and caudal lobes. Airway branches were assigned binary numbers indicating their specific location in the tracheobronchial tree. Samples of known airway generation were resin embedded and examined by light‐microscopy. Based on differences in cell morphology, staining properties, and distribution, eight major cell groups were recognized and quantified: four mucous cell categories (M1, M2, M3, and M4), ciliated, basal, Clara, and serous cells. The last cell category was restricted to submucosal glands. Tracheal epithelium had the most cells per unit length, primarily due to large numbers of basal cells. Basal cells are found in the epithelium of airways without cartilage or glands. The total mucous cell population (M1, M2, and M3) in proximal airways was relatively constant. M4 mucous cells were present in glands of proximal airways and in the epithelial lining of the airways without glands. The most distal airways were lined by Clara and ciliated cells. A small number of the most proximal noncartilaginous airways had mucous (M1, M2, M3, and M4), basal, and Clara cells sharing the epithelial lining. We conclude that in the sheep lung: (1) epithelial cell distribution does not correlate with airway wall components; (2) more than one type of secretory epithelial cell can share the lining of the same airway; and (3) Clara cell distribution is based on airway generation and proximity to alveoli.
Light and scanning electron microscopic study of testosterone‐restored penile papillae in castrated rats
Authors: Taylor George T. , Komitowski Dymitr , Weiss Jürgen 
Published: February 2005

AbstractStructural changes in various penile tissue from rats with differing circulating androgen levels were analyzed with light and scanning electron microscopy. Adult males were castrated and daily injected for 6 weeks with one of four physiologic amounts of testosterone propionate (TP). Results indicated that epithelium, subepithelial connective tissue, and the papillae protruding from the surface of the glans penis responded, more or less, in a dose‐dependent fashion to the steroid. The least androgen‐sensitive penile tissue was the epidermal stratum corneum, more sensitive was the maligiphian layer, and more sensitive still was the subepithelium. The penile papillae and their follicles were the most androgen‐sensitive tissue. Specifically, the high testosterone, 400 μg and 800 μg TP, males experienced papillae that were thicker, taller, more densely arranged, and more highly keratinized than the lower testosterone, 100 μg and 200 μg TP, males. The function of the papillae may be to provide the female with the mechanical stimulation necessary to ensure a proper hormonal milieu for successful impregnation.
Suppression of adernal cortical growth and differentiation in fetal rats exposed to dexamethasone
Authors: Garvey David , Migally Nabil , Sullivan Jon , Sullivan Lori 
Published: February 2005

AbstractThe effects of maternal dexamethasone (DEXA) administration during the last days of gestation on fetal adrenal growth and differentiation were studied. Timed pregnant rats were divided into three groups: (a) 21d DEXA‐3 received DEXA in drinking water (5 μg/ml) from days 18 to 21 of gestation; (b) 21d DEXA‐6 received the same dosage of DEXA from days 15 to 21 of gestation; and (c) 21d control received tap water throughout gestation. On gestation day 21, pregnant rats were decapitated and ble into heparinized tubes; their fetuses were excised, weighed, decapitated, and bled. Fetal adrenals were prepared for electron microscopy or weighed and frozen until assayed for corticosterone. Control adrenals were also collected on day 15 of gestation and processed for electron microscopy only. Fetal adrenals were fixed in 2.5% glutaraldehyde in 0.5 M cacodylate buffer, postfixed in 2% osmium tetroxide (OsO4), dehydrated, and embedded in Epon 812. Twenty‐one day (21d) fetal adrenal weights were 44% and 68% lower than control values for DEXA‐3 and ‐6, respectively. Fetal adrenal corticosterone levels were decreased by 70% and 89% for the respective groups. These observations correlated with ultrastructural findings of decreased mitochondrial number and size, altered orientation of the inner mitochondrial membrane, decreased lipid, and dilation of smooth endoplasmic reticulum (SER) in cortical fascicular cells of DEXA‐exposed fetuses. Ultrastructural changes in the 21d DEXA fetal adrenals resembled 15d day control fetal adrenals. The results suggest suppressed adrenocortical differentiation probably due to DEXA inhibition of the steroidogenic influence of the fetal pituitary on the developing adrenal gland in DEXA‐exposed fetuses.
Three‐dimensional reconstruction of the rat incisor by means of computerized histomorphometry
Authors: Steigman S. , Michaeli Y. , Weinreb M. , Zajicek G. 
Published: February 2005

AbstractA detailed, quantitative, three‐dimensional reconstruction of the adult rat lower incisor is presented. The mandibles of 12 male adult rats were dissected and radiographed. The outline of each incisor was traced and the center of the arc formed by the lower, or labial, border of the tooth was geometrically determined. The sector of the bone‐embedded part (mean length 20.70 ± 3.5 mm) of the tooth was divided into six equal segments by radii drawn through the arc center. The dividing radii were transposed onto the specimens and three consecutive 100‐μm transverse ground sections were cut from the incisal side of each segment, parallel to their bordering radii. The distance between each section and posterior wall of the alveolar socket was measured and the information stored in the computer. The outlines of all the dental structures were traced and fed into a computer with the aid of a sonic digitizer. The circumference of the tooth (5.91 ± 0.002), and the mesiolateral and labiolingual widths (1.36 ± 0.001 mm and 2.18 ± 0.01 mm, respectively) remained constant at all tooth levels. The decrease in width and cross‐sectional area of the pulp and the corresponding increase in dentin were represented by the best fitted second order polynomials. These changes were not uniform, being more pronounced in the proximal part of the tooth. The polynomials also served for calculation of the total volumes of pulp, dentin, and enamel (13.93 mm3, 18.05 mm3, and 4.43 mm3, respectively). The three‐dimensinal measurements included the periodontal ligament (PDL), which was significantly wider on the lateral side than on the mesial (0.16 ± 0.006 mm and 0.12 ± 0.004 mm, respectively). The volumes of the enamel‐bordering PDL and of the cementum‐bordering PDL were 7.77 mm3 and 8.67 mm3, respectively. In the latter, the tooth‐related compartment constituted 42.7% of the total volume. The data presented can serve as a basis for future quantitative studies of the rat incisor.
Effect of estradiol on ultrastructure of granular ducts in submandibular glands of female rats
Authors: Flynn Evelyn A. , Yelland Kenneth T. , Shklar Gerald 
Published: February 2005

AbstractThe effects of estradiol on the granular ducts in submandibular glands of female albino rats were studied. Twenty‐five‐milligram pellets of 17 β‐estradiol were implanted subcutaneously in the experimental animals, and their glands, as well as controls, were examined after 2, 4, 7, and 10 wk using light and electron microscopy. During the course of the experiment an increasing proportion of the granules in the granules ducts appeared more lightly stained in the experimental animals. In the estradiol‐treated rats the granular ducts increased in relative cross‐sectional area at a faster rate than in the controls, which exhibited maturation changes. In addition, the average number of granules per granular duct cell decreased significantly in the treated animals. Our results indicate that estradiol caused a change in the cytology of the granular ducts suggesting an alteration in protein synthesis. These results might occur through a change in structural proteins or in other hormones and growth factors which are known to influence the submandibular gland.
Noradrenergic innervation of the penis in control and streptozotocin‐diabetic rats: Evidence of autonomic neuropathy
Authors: Felten David L. , Felten Suzanne Y. , Melman Arnold 
Published: February 2005

AbstractThe noradrenergic sympathetic innervation of the penis of control and 4‐month streptozotocin‐diabetic rats was examined with the glyoxylic acid histofluorescence method. Noradrenergic varicosities were found in the corpora cavernosa in a dense subtunical plexus and in the perisinusoidal and trabecular regions of the erectile tissue, in the corpus spongiosum in perisinusoidal tissue, around large arteries and veins, and around small tortuous arterioles and small draining veins of the corpora cavernosa and spongiosum. Noradrenergic varicosities were diminished in number and fluorescent intensity in all regions of the penis of diabetic rats compared with controls. The subtunical plexus was absent, perisinusoidal and trabecular varicosiities were sparse, and only occasional intermittent, discontinuous, dull fluorescent fibers or plexuses were found around the vessels. Quantitation with highperformance liquid chromatography revealed a significant reduction of norepinephrine in the penis of diabetic rats compared with controls. The present study suggests that long‐term streptozotocin diabetes in the rat is accompained by sympathetic autonomic neuropathy of the penis that seems to parallel changes in the noradrenergic content of penile corpora of men with diabetes and erectile impotence. The streptozotocin‐diabetic rat merits further study to explore the relationship between noradrenergic innervation of the penis and erectile tissue.
The development of specific antibody‐containing cells and the localization of extracellular antibody in the follicles of the spleen of rabbits after administration of free or liposome‐associated albumin antigen
Authors: van Rooijen N. , Kors N. , van Nieuwmegen R. , Eikelenboom P. 
Published: February 2005

AbstractIn order to study the localization pattern of specific antibody‐containing cells and extracellular antibody in the spleen during a primary immune response, the antigen human serum albumin (HSA) was injected intravenously in rabbits, either free in solution, or associated with the surfaces of liposomes as a model of membrane‐associated antigens. Demonstration of specific antibody‐containing cells was performed by incubation of sections of spleen with HSA‐HRP conjugates, followed by peroxidase cytochemistry.Specific anti‐HSA antibody‐containing cells were detected already at 4 days after injection of the antigen. The bulk of these cells localized initially in the outer parts of the periarteriolar lymphocyte sheaths (PALS) and around the terminal arteriolar branches. Both extracellular antibody and specific antibody‐containing cells were also found in the follicles of the spleen. Arguments are given that extracellular antibody precedes the development of specific antibody‐containing cells in the follicle. This extracellular antibody probably represents antigen‐antibody complexes trapped in the follicles as soon as the antigen in the circulation is complexed by the first antibodies produced during the immune response. The localization pattern of specific antibody‐containing cells and extracellular antibody did not differ markedly when rabbits injected with free or liposome‐associated antigen were compared. Results are discussed particularly with respect to the role of follicles in the immune response.
Envirnmental conditions prerequisite for complete limb regeneration in the postmetamorphic adult land‐phase salamander, Ambystoma
Authors: Young Henry E. , Bailey Claudia F. , Dalley Bernell K. 
Published: February 2005

AbstractHistorically, postmetamorphic adult land‐phase salamanders have been shown to exhibit minimal to nonexistent limb regeneration. Hence, it has been generally accepted that these forms have lost the intrinsic capacity to regenerate a limb. Due to the experimental protocols used, an alternate explanation is also possible: that this intrinsic capacity cannot be expressed when the salamanders are maintained under adverse laboratory environmental conditions. Therefore, this study addresses two questions: (1) What are the optimal environmental conditions for long‐term survival of adult land‐phase salamanders; and (2) will complete limb regeneration occur in these salamanders if they are maintained under survival conditions. A mixed population of adult Ambystoma were tested under varying conditions of habitat, temperature, humidity, photoperiod, and food source. Complete limb regeneration was possible in 100% of four species of adult postmetamorphic land‐phase Ambystoma salamanders given the proper environmental laboratory conditiions of a peat moss and potting soil habitat with a controlled temprature of 25°C ± 5°C, 70% or greater humidity, a 12/12 light/dark photoperiod, a diet including nightcrawlers released into their respective terraria, and an extended observation time of up to 370 days postamputation (dpa). Regeneration was completed during the following range periods for the adult salamanders: A. annulatum, 324 to 370 dpa; A. maculatum, 255 to 300 dpa; A. texanum, 215 to 250 dpa; and A. tigranum, 155 to 180 dpa.
Isolation by flow sorting of cytokinetic and morphological heterogeneity in late‐passage cultures of human diploid fibroblasts (IMR‐90)
Authors: Kelley Robert O. , Perdue Bradley D. , Uruchurtu‐Valdivia Richard A. 
Published: February 2005

AbstractConsiderable structural, metabolic, and proliferative heterogeneity develops in populations of cultured diploid cells which have reached advanced levels of population doubling. Isolation of noncycling cells from late‐passage cultures would permit more definitive investigation of the structure and behavior of individual senescent cells. In this paper, we report the viable sorting of late‐passage cultures of human diploid fibroblasts (IMR‐90) into two subpopulations of cells with different proliferative potentials. Sorting is based on cellular light‐scattering properties and autofluorescence. Structural and behavioral features of the subpopulation exhibiting increased forward‐angle light scatter are more characteristic of senescent cells than the subpopulation sorted by decreased forward‐angle light scatter.
Hepatic sinusoidal endothelium in sheep: An ultrastructural reinvestigation
Authors: Wright Peter L. , Smith Kathryn F. , Day William A. , Fraser Robin 
Published: February 2005

AbstractFollowing perfusion fixation of livers from fetal, neonatal, and adult sheep, the ultrastructure of the fenestrated sinusoidal endothelium was examined. In contrast to an earlier report which utilized immersion fixation, we found the fenestrae to be unoccluded by diaphragms or basal lamina, thus offering only a discontinuous barrier between the blood and the space of Disse and hepatocytes. This observation was confirmed by perfusing the liver with marker particles. The fenestrae appear, therefore, to have a sieving function, regulating the metabolism of particulate matter such as lipoproteins in sheep in a similar manner to that which has been shown to occur in rats.
Ontogeny of Peyer's patches of the rat
Authors: Sminia T. , Janse E. M. , Plesch B. E. C. 
Published: February 2005

AbstractThe development of lymphoid and nonlymphoid cells in Peyer's patches (PP) of the rat was investigated using light microscopical methods (routine histological techniques, enzyme histochemistry and immunohistochemistry). In newborn rats PP were mainly populated by T lymphocytes and Ia‐positive nonlymphoid cells, which most likely are interdigitating cells. At about 12 days after birth the B and T cells were localized in defined regions, the follicular (FA) and interfollicular area (IFA), respectively. Compartmentalization within the FA started about 14 days after birth. The first signs of the development of secondary follicles were seen from about 18 days onward. PP obtained their mature structure at about 4 weeks after birth. It is suggested that after PP had developed fully, cells having cytoplasmic IgA migrate via the high endothelial venules (HEV) to the lamina propria of the intestine; cIgM and IgG cells seem to develop locally within the FA.
The preparation of human cross sections
Authors: Boushey Dallas Richard , Stultz Walter Alva 
Published: February 2005

AbstractTechnical advances in the field of radiology, especially computerized axial tomography (CAT) scanning, have made gross anatomical crosss‐sections increasingly important in understanding the relationships of internal structures. Since 1940, the Anatomy Program at the University of Vermont has developed and used cross‐sections of the entire human body in teaching predoctoral, postdoctoral, and allied health professionals. This paper describes in detail the process through which specimens are selected, embalmed, frozen, sectioned, and displayed. Kaiserling's Method is used for fixation and preservation of the specimens, which are then housed in appropriate display containers. Specimens prepared over forty years ago in the manner described in this paper are still in use.