bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regional variation in the surface morphology of the epithelium of the rat ductuli efferentes, ductus epididymidis and vas deferens
Authors: Hamilton David W. , Olson Gary E. , Cooper Trevor G. 
Published: February 2005

AbstractThe luminal surface ofepithelial cells lining the ductuli efferentes, ductus epididymidis and first portion of the vas deferens were studied with the scanning electron microscope. In ductuli efferentes obvious ciliated cells are identified and it is shown that on non‐ciliated cells the short microvilli adhere to one another to form clumps of microvilli. In the epididymis two cell types are described and can be identified as principal cells and clear cells based on the presence or absence of microvilli. Clear cells vary in number along the duct, being most numerous distally. Their surface morphology is also most variable distally. In the vas deferens, principal cells with surface microvilli are easily identified; but in addition, a second cell type is seen, the identity of which is not known.
Cell kinetics in the small intestine of suckling rats I. Influence of hypophysectomy
Authors: Yeh Kwo‐Yih 
Published: February 2005

AbstractCell kinetics have been examined in the duodena of intact rats at 6, 16, and 22 days of age, and of hypophysectomized rats at 22 days. In intact rats the crypt population per villus increases more than 10‐fold, the greater part of the increase occurring late in the third week. The labelling index does not differ between 6 (28.3%) and 16 (27.6%) days, but increases to 37.8% at 22 days. Generation time also does not differ between 6 (18.0 hours) and 16 (17.7 hours) days, but falls to 10.8 hours at 22 days by shortening of both the presynthetic and synthetic phases. Acceleration of cell migration rate between 18 and19 days of age results in shortening of cell transit time from seven days in rats younger than 18 days to two days in those older than 18 days.When rats are hypophysectomized at six days, the duodenal crypt population per villus at 22 days is comparable to that of intact rats at 16 days. The labelling index at 22 days is 19% below that of intact rats at six days. Generation time at 22 days is slightly shortened by a decrease of the presynthetic phase, but the duration of 15.5 hours is 43% longer than in intact rats at the same age. Despite the small crypt population and the low cell production rate, the cell‐transit time in 22‐day‐old hypophysectomized animals is only three days.
A comparison of the protein synthetic activity of presecretory and secretory ameloblasts in rat incisors
Authors: Warshawsky H. , Vugman I. 
Published: February 2005

AbstractPresecretory ameloblasts were compared morphologically and functionally to secretory ameloblasts in the rat incisor. Structurally, the cell types are similar except for the absence of a Tomes' process at the presecretory stage. The developmental changes at the apical end of the ameloblast were described and correlated sequentially with the onset of extracellular events. First, a layer a amorphous dense material appeared at the dentinal surface adjacent to the ameloblasts. Second, the initial layer of enamel began to develop. Third, inner enamel secretion began with the appearance of interrod enamel. This occurred concomitantly with the appearance of the interdigitating portions of Tomes' processes.Functionally, the protein synthetic activity of presecretory ameloblasts was compared to secretory ameloblasts. Light microscopic radioautography of 1‐m̈m thick Epon sections was used to localize 3H‐proline and 3H‐tyrosine at various times after injection. At time intervals up to 20 minutes the two presursors were localized as a band of labeled protein in the supranuclear cytoplasm of both presecretory and secretory ameloblasts. At 30 minutes an additional band of radioactivity was localized within the apices of both types of ameloblasts. In presecretory cells the apical reaction band was over the proximal portion of Tomes' processes which border on the dentin. In the secretory cells, the apical reaction band was over both proximal and interdigitating portions of Tomes' processes and over the enamel. Grain counts over the secretory ameloblasts showed that the incorporation of tyrosine increased by 7.5% as opposed to a 63% increase with proline when compared to the values in presecretory cells. The different increases with the two precursors were in keeping with the different amounts of the two amino acids reported to be present in enamel protein.It was concluded that while the secretory ameloblasts synthesize and secrete enamel protein, both presecretory and secretory cell types produce another category of protein which is involved in the apical reaction band. It was proposed that this material is structural protein being contributed to the continuously lengthening Tomes' process which is speculated to occur during formation of enamel.
Intraperitoneal transplants of taste buds in the newt
Authors: Poritsky Raphael , Singer Marcus 
Published: February 2005

AbstractAutografts of tongue onto the liver contained taste buds without nerves for up to 30 days. However, these denervated taste buds were generally smaller than normal and distorted in structure. Nerve fibers invaded the graft from the liver and after 30 days normal appearing taste buds were found only in implants of tongue which contained extensive nerve fibers. Thus it appears that certain visceral nerves can maintain and possibly induce taste bud formation in implants of tongue. This is interpreted as additional evidence for the trophic influence of nerves upon taste buds. Moreover, this ability to maintain taste buds is not restricted to gustatory nerves in the newt.
The embryonic development of the proctodeal gland of Coturnix coturnix japonica (Aves)
Authors: Schafersman Lynn R. , Klemm Robert D. 
Published: February 2005

AbstractThe embryogenesis of the proctodeal gland and development of the connective tissue of the associated lamina propria in the dorsal wall of the proctodeum of Common Coturnix (Coturnix c. japonica) were studied on embryos collected at 12‐hour intervals from day 7 of incubation through hatching. Gland development began at 9.5 days from ectodermal‐derived epithelial buds developing in the craniolateral region of the dorsal proctodeal epithelium. At 11 days, the epithelial buds had become solid convoluted epithelial cords which, by 11.5 days branched to form solid individual glandular units. Lumina of the unit were formed by degeneration and vacuolization of the central cells of these solid units. Squamous epithelial caps, several layers thick, separated the vacuolizing units from the proctodeal cavity at day 13; these caps subsequently thinned, bulged into the proctodeal cavity and, by day 16, began to disappear opening the lumen of the units to the proctodeal cavity.Sequential formation of epithelial buds, by region, was: craniolateral at 9.5 days, craniomedial expansion at 10.5 days followed, beginning at 11 days, by cau‐dal expansion along entire dorsal proctodeal wall. Sequence of appearance of gland‐associated connective tissue fibers was: 9.5 days, reticular fibers already present; 11 days, collagen fibers; 11.5 days elastic fibers.Serially reconstructed models of an individual glandular unit at hatching enabled classification of the unit as a simple branched alveolar gland.
Cytodifferentiation of pituitary primordia transplanted to the kidney capsule of adult hosts
Authors: Gash Don , Ahmad Nazir , Schechter Joel 
Published: February 2005

AbstractThis study demonstrates the ability of pituitary anlagen from 12‐ and 15‐day embryonic rats to undergo cytodifferentiation in a site distant from that of its normal juxtaposition with the hypothalamus.Pituitary anlagen (PA) were isografted from 12‐ and 15‐day‐old embryonic donors to under the kidney capsule of intact adult female rats. Seventeen days later the grafts were recovered and processed for light and electron microscopy (LM and EM). Four of six 12‐day and all five 15‐day PA grafts developed into adenohypophyseal‐like tissues. At the light as well as EM level, no consistent quantifiable differences could be detected between the glandular tissues that developed from the two different donor groups. While most of the cells within anterior pituitary‐like tissue were chromophobic at the LM level, some cells were stained positive with periodic acid‐Schiff and Orange G. Examination by EM revealed that most cells within the glandular portions of the grafts were granular and that these cells could be grouped into three general categories based on their secretory granule morphology. The sizes of the secretory granules ranged from 150‐550 nm in diameter. Clear examples of exocytosis of the granules were evident in grafts of both 12‐ and 15‐day PA, usually in areas of the graft that were more vascularized. In some cells exocytosis was extensive. Agranular cells in the graft parenchyma included follicular and undifferentiated cells.The results of this investigation suggest that kidney capsule grafts may prove useful in elucidating the factors that influence pituitary development.
The aberrant course of the cutaneous component of the ilioinguinal nerve
Authors: Oelrich Thomas M. , Moosman Darvan A. 
Published: February 2005

AbstractThe ilioinguinal nerve was dissected in 196 adult human cadavers. A normal pattern of distribution, consistent with modern textual descriptions, was defied in 60% of in guinal regions. In 35% of the inguinal regions a previously undescribed aberrant course for the cutaneous component of the ilioinguinal nerve was observed in which it is incorporated within the genitofemoral nerve, entered the inguinal canal at the deep inguinal ring, coursed within the cremasteric layer and emerged into the subcutaneous tissue at the superficial inguinal ring on the dorsal side of the spermatic cord or the round ligament of the uterus. The cutaneous component of the ilioinguinal nerve is most frequently found on the ventral surface of the spermatic cord or round ligament during inguinal hernia operations thus an unrecognized aberrant course of this nerve within the spermatic cord is particularly susceptible to accidental trauma.
Embryonic and fetal hemopoiesis in the mongolian gerbil (Meriones unguiculatus)
Authors: Smith Richard A. , Glomski Chester A. 
Published: February 2005

AbstractA study of the development of hemopoiesis in the Mongolian gerbil (Meriones unguiculatus) was conducted in order to determine the temporal sequence, the organs involved and the cytology of blood cell formation in this species. Hemopoiesis in the intrauterine life of the gerbil can be divided into four phases based on the site of blood cell formation: (1) the vitelline phase, (2) the hepatic phase, including thymic histogenesis, (3) the splenic phase and (4) the medullary phase, with the development of secondary lymphoid tissues. At the onset of each of these phases a blast‐like cell was identifiable in each hemopoietic organ which, because of its morphology and its presumed multipo‐tentiality was classified as a “lymphoid cell.” In the yolk sac phase (gestational day 12) two generations of erythrocytes, a primitive and a definitive, are formed. The liver is by day 15 erythropoietic and megakaryopoietic, but later, a few gran‐ulocytes are also found in its extravascular compartment. The thymus is exclusively lymphopoietic from the appearance of its earliest cells on day 15. Splenic hemopoiesis is initiated with the presence of lymphoid cells (day 20) followed later by the appearance of morphologically identifiable blood cell lines. Early normoblastic and granulocytic activity begins in the marrow cavities on day 23, though the marrow is not considered to be a source of circulating blood cells during fetal life. Lymph node histogenesis occurs during the last four days of gestation, first in the cervical region and then in other parts of the body. The finding of undifferentiated lymphoid cells in all organs at the initiation of hemopoiesis and in the peripheral blood throughout gestation is discussed in light of the migratory theory of hemopoiesis.
Response of the adult newt, Notophthalmus viridescens to partial or complete gonadectomy
Authors: Scadding Steven R. 
Published: February 2005

AbstractFollowing partial castration of the newt, the remaining testis hypertrophies until it reaches the normal testis mass for the current season of the year. The effect of seasonal changes in testis growth and morphology on the hypertrophy of the testis are discussed. Following partial ovariectomy of the newt, there is no regenerative response. The remaining ovarian fragment remains the same size or partially degenerates. No evidence could be found for regeneration of the gonad from non‐gonadal tissue following total gonadectomy.
Autoradiographic analysis of altered glycosaminoglycan synthesis in the epiphyseal cartilage of neonatal brachymorphic mice
Authors: Greene Robert M. , Brown Kenneth S. , Pratt Robert M. 
Published: February 2005

AbstractBrachymorphic (bm/bm) mice are disproportionately short in stature. Past biochemical studies on neonatal mice (Orkin et al., '76) demonstrated that epiphyseal cartilage from these mutants synthesizes glycosamino‐glycans (GAG) that are undersulfated. In this study, synthesis of GAG, as determined autoradiographically with Na2 35SO4 and 3H‐glucosamine was reduced in all areas of bm/bm epiphyses both in vivo and in vitro as compared to normal C57BL/6J mice. Incorporation of both isotopic precursors into GAG of the brachymorphic proliferative zone was reduced to a greater extent than in the reserve zone. In addition, incorporation of these precursors into GAG of epiphyseal cartilages in vitro, as determined biochemically, was reduced by 40%. In contrast, the incorporation of 3H‐leucine and 3H‐proline into protein did not show differences between mutant and normal epiphyses. These results suggest that alterations in GAG synthesis in bm/bm epiphyseal growth plates are not exclusive to any one zone, but do appear to be most pronounced in the proliferative zone.
A study of the structure of the papilla neglecta in the lizard, Anolis carolinensis
Authors: Baird Irwin L. , Lowman Gerald F. 
Published: February 2005

AbstractScanning and transmission electron microscopy have been used to investigate the structure of the papilla neglecta in the lizard, Anolis carolinensis.Situated in the posterior part of the utricle, the receptor is innervated by a branch of the posterior ampullary nerve and is covered by an extracellular membrane that exhibits a tapering extension into the orifice of the utriculo‐saccular duct. The neuroepithelium contains two populations of sensory cells within a matrix of sustentacular cells; one population (non‐calyceal hair cells) is supplied primarily by boutons and clublike terminals, while the other (calyceal hair cells) is served by calycine terminals that invest from one to five sensory cells. The apices of calyceal hair cells bulge into the utricular lumen and have larger diameters and ciliary counts than non‐calyceal cells, but other differences are not marked. Although the bases of calyceal hair cells are deeply indented by calyceal processes, both types show similar afferent synaptic structures confined to the nuclear and infranuclear regions. Efferent terminals synapse on afferent endings and hair cells in both cases; synapses directly on calyceal hair cells lie above the calyx, just beneath the apicolateral junctional complexes. Those complexes are basically similar throughout the receptor, except that a hemispheroidal gap junction between a supporting cell and adjacent hair cell was noted in several instances. Arrays of endoplasmic reticulum and specialized mitochondria occur adjacent to aggregations of afferent synaptic vesicles in both types of sensory cell; it is suggreted that such arrays may participate in the production of the vesicles in a process involving membrane recycling similar to that at the neuromuscular junction. Differences between calycine units and the type I hair cell of mammals are discussed, and evidence that suggests an equilibratory function for the lacertilian papilla neglecta is presented.
Embryologic origin of the various epithelial cell types in the second kind of thyroid follicle in the C3H mouse
Authors: Wollman Seymour H. , Hilfer S. Robert 
Published: February 2005

AbstractThe thyroid gland of the C3H mouse is composed largely of the usual follicle but it also contains a second kind of follicle. To ascertain the embryologic origin of the cell types in each of these follicles, ventral pharyngeal outpocketings and ultimobranchial outpocketings were isolated (before they fused to form the thyroid gland) from the 12‐day‐old fetus of the C3H mouse. The outpocketings were implanted into different kidney capsules of adult C3H mice and were allowed to grow for several months. Transplants were then excised and examined by electron microscopy.The ventral contribution formed large aggregates of follicles and was recognized as a distinct bump on the surface of the kidney. It formed only typical thyroid epithelium arranged in follicles containing colloid. On the other hand, the ultimobranchial contribution usually formed only a small number of follicles, generally of small size. It was readily located because the follicles occurred next to a white plaque of bone or cartilage at the site of implantation. The ulti‐mobranchial contribution formed follicles containing four cell types: a ciliated cell, a cell with abundant agranular reticulum, a cell with many free ribosomes and fiber and occasional hemidesmosomes, and the C cell which was the most frequent cell type. No typical thyroid epithelium was observed in the ultimobran‐chial transplant.These observations suggest that the C cell in the usual follicle is derived from the ultimobranchial contribution, and that the second kind of follicle is largely an ultimobranchial contribution but the typical thyroid epithelium in it is largely or entirely a ventral contribution.
Progenitor cells of erythroblasts: An in vitro investigation of erythropoietin‐responsive cells of guinea pig bone marrow
Authors: Rosse Cornelius , Beaufait David W. 
Published: February 2005

AbstractThe experiments were designed to test whether or not erythroblast progenitor cell function could be demonstrated in a morphological cell type designated as “transitional cells.” Two cell fractions, were obtained from the bone marrow of normal and polycythemic guinea pigs. One fraction (F1) was enriched in transitional cells and contained few, if any, other cell types which could be considered as candidates for erythropoietin responsive cells (ERC). The other fraction (F2) contained undifferentiated blast cells as well as transitional cells. The effect of human urinary erythropoiesis stimulating factors (ESF) on heme synthesis was compared in these two fractions by measuring 59Fe incorporation into heme. ESF was more effective in stimulating heme synthesis in guinea pig bone marrow cells than homologous sera obtained from anemic or hypoxic animals. The majority of ERC sedimented in F2, but the stimulation index was comparable in the two fractions. It was confirmed by radioautography that the ESF reesponse in F1 was due to the generation of proerythroblasts and basophilic erythroblasts that incorporated 55Fe. The generation of these cells in F1 was dependent on the addition of ESF to the cultures, whereas 55Fe‐labeled erythroblasts were recovered from cultures of F2 not supplemented with ESF. ESF induced a proportion of transitional cells to incorporate 55Fe in both F1 and F2. Transitional cells were the only cell type in which heme synthesis was dependent on ESF. In other cells of clearly non‐erythroid morphology (mononuclear phagocytes and reticular cells), 55Fe incorporation occurred independent of ESF.Although the fractionation procedure employed is unsuitable for the separation of ERC from bone marrow, it permitted the enrichment of transitional cells, a cell type defined by morphology. Radioautography with 55Fe identified a proportion of these cells as ERC in both F1 and F2 fractions of bone marrow obtained from normal and polycythemic guinea pigs. Although there may be other cell types in F2 capable of responding to ESF, the present studies show that some transitional cells function as progenitors of erythroblasts because they respond to ESF by initiation of heme synthesis and by transformation into the earliest recognizable erythroid cells.
Sympathetic connections to the fifth and sixth cranial nerves
Authors: Parkinson Dwight , Johnston Jane , Chaudhuri Anup 
Published: February 2005

AbstractThirty additional parasellar gross dissections and light microscopic examinations have been carried out, confirming a previous observation that the sympathetic nerve or nerves running with the carotid artery gives off a multitude of fine branches at irregular intervals on the way up, but the largest residual component joins the sixth cranial nerve and leaves to join the first division of the fifth cranial nerve. No similar fibers can be found by us to join the third or fourth cranial nerve. Based on the observations that section of the sympathetic in the neck results in a Horner's syndrome and that section of the ophthalmic artery at its point of departure from the carotid does not result in any part of Horner's syndrome nor does section of the external, internal or common carotid in the neck, it is assumed that these fibers process the functions the absence of which result in Horner's syndrome.
Erythropoietic response of hypertransfused neonatal rats suckled by anemic mothers
Authors: Carmichael Robert D. , Gordon Albert S. , Lobue Joseph 
Published: February 2005

AbstractTwelve‐day‐old hypertransfused neonatal rats nursed for four days by a twice‐bled mother exhibited higher 48‐hour RBC‐59Fe incorporation than control neonates nursed by a normal mother. Erythropoietin (Ep) in plasma of 12‐day‐old hypertransfused neonates suckled for four days by twice‐bled mothers was initially equivalent to approximately 0.5 IU/day. This calculation was based on the observation that reticulocytosis induced in these animals was similar to that produced in neonates of the same age injected intra‐peritoneally with 0.5 IU Ep for four days while nursing from normal mothers. The reticulocyte maturation curve was shifted to the left in 12‐day‐old hy‐pertransfused neonates suckled by anemic mothers, and in 12‐day‐old normal neonates rendered anemic by bleeding, while nursing from normal mothers. This left‐shift of the reticulocyte maturation curve was also evident in 12‐day‐old hypertrans fused neonates injected with Ep.Decreases in relative percentages of nucleated RBC was evident in spleens of 12‐day‐old neonates nursed by anemic mothers and spleens of 12‐day‐olds injected with Ep. Significant reduction in nucleated RBC were noted in both spleen and marrow of 12‐day‐old anemic neonates.These results suggest: (1) Ep, present in increased amounts in the anemic mother, is transmitted through milk to nursing neonates thereby stimulating erythropoiesis in these animals; (2) Ep may not stimulate stem cell differentiation towards the erythroid compartment but rather acts on already differentiated erythroid cells by influencing their rate of maturation.
Scanning electron microscope study of the developing trout pelvic fin bud
Authors: Geraudie Jacqueline 
Published: February 2005

AbstractThe growth of the pelvic fin bud has been studied with the SEM along with the characteristics of the pseudoapical epidermal ridge which occupies the free margin of the bud. SEM revealed fluffy protuberances in many of the epidermal cells, distinguishing the fin bud territory from adjacent areas. When the pseudoapical ridge appears, all the cells show this feature but their relative number decreases and these cells, termed the “tassel cells,” are finally restricted to the base of the fin bud. This particular surface structure of the superficial cells may be unique to the fish, since it has not been heretofore reported in SEM studies of tetrapod limb bud.