bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fine structure of the interstitial cells of leydig in the boar
Authors: Belt W. D. , Cavazos L. F. 
Published: February 2005

AbstractThe interstitial cells of the testis of the boar have been characterized by electron microscopy. The bulk of the cytoplasm, to one side of an eccentrically placed nucleus, consisted predominately of a tightly packed agranular endoplasmic reticulum in a system of anastomosing tubules. Free ribosomes and a few short strands of granular endoplasmic reticulum were present only in a perinuclear or subplasmalemmal location. Mitochondria were abundant as a cluster in the center of the cytosome. Surrounding them were dense bodies, most of which were bounded by a single limiting membrane. The internum of the dense bodies exhibited a variety of appearances. Filaments of 70 Å were common but they were absent near the plasmalemma. Between contiguous cells, irregularly disposed microvilli protruded into an intercellular space of variable dimensions. Some sites of membrane fusion, resulting in maculae occludentes, were observed between adjacent cells, while small desmosomes were observed but rarely. Coated vesicles were frequent near to and continuous with the plasmalemma as well as deeper within the cell, especially in association with elements of the Golgi apparatus.
Delayed incubation: A cause of variability in the embryogenesis of the Japanese quail, Coturnix coturnix japonica
Authors: Manner Harold W. , Granik Barbara H. 
Published: February 2005

AbstractEggs of the Japanese quail, Coturnix coturnix japonica were collected over a five‐day period and incubated simultaneously, in accordance with currently accepted commercial practice. After 33 hours of functional incubation, the embryos were fixed and the somites counted to determine the age of the embryo. A great range of variation was encountered, supporting earlier published work. This variability, however, was not random, but inversely related to the length of time the eggs were “held” before incubation. This study suggests that the practice of “holding” eggs be discontinued in all work where uniformity of developmental stages is essential.
DNA synthesis by cultured myocardial cells
Authors: Rumery Ruth E. , Rieke William O. 
Published: February 2005

AbstractMyocardial cells cultured from ventricles of 4‐day embryonic chick hearts were labeled with H3‐thymidine for the radioautographic study of DNA synthesis and nuclear cycling. After the myoblasts had been in culture for 48 hours and had begun to grow out and contract, the cultures were exposed to H3‐thymidine, 1 μc/ml of Hank's balanced salt solution, for one hour. Pairs of cultures were fixed in methyl alcohol for analysis every two hours over a subsequent period of 60 hours. The total percentage of labeled cells, together with labeled mitotic figures which developed after labeling, determined the average values for generation time and nuclear cycle phases as follows: generation time, 45 hours; DNA synthesis, nine hours; G2 interval, 2–6 hours; G1 interval, 27–33 1/2 hours; and mitosis, one‐half to one hour. Autonomous control of DNA synthesis was observed occasionally in a binucleate cell having only one labeled nucleus, although both nuclei were in a similar phase of mitosis. It is evident from these data that cultured myocardial cells synthesize DNA similarly to other cells.
Chemotaxis of mature and immature blood cells in tissue cultures
Authors: Kass Lawrence , De Bruyn Peter P. H. 
Published: February 2005

AbstractThe chemotactic behavior of the cells of bone marrow, lymph node, and buffy coat has been studied in tissue culture. Heat‐attenuated S. aureus was found to be a consistent and convenient chemotactic agent. Mature granulocytes showed chemotaxis to this agent, whereas bone marrow stem cells did not show chemotaxis. In this respect they behaved like lymphocytes of peripheral blood or of lymphatic tissue, which also do not exhibit chemotactic behavior. The chemotactic, locomotory and morphologic similarities between the lymphocyte and the stem cell of the bone marrow are discussed in relation to the developmental potencies of these cells. Chemotactic behavior of the granulocytes appears to develop between the myelocyte and the metamyelocyte stages. It is possible that the granulocytes have differences in chemotactic ability in vivo also, which could be a factor in the selective migration of the mature granulocytes from their extravascular sites of formation into the peripheral blood. Cells of the erythrocyte series did not show chemotaxis.
Pseudoepiphyses or notches in the non‐epiphyseal end of metacarpal bones in healthy children
Authors: Lee Marjorie M. C. , Garn Stanley M. 
Published: February 2005

AbstractLongitudinal series of hand x‐rays from healthy white children (116 boys, 118 girls) of Fels growth studies were investigated. Notchings of the nonepiphyseal end of the first, second and fifth metacarpal bones were found in every child. Beginning from infancy or early childhood, the notchings follow a sequence of developmental stages (obtuse‐angle; acute‐angle; cleft: underlying, edge‐to‐edge, overjutting; and fusion) until they disappear one to one and one‐half years before onset of puberty. The notching intensity in the second and the fifth metacarpal bones was rated. A moderate degree of association in notching intensity was demonstrated between brothers and sisters.
Time of transuterine migration and distribution of embryos in the pig
Authors: Dhindsa D. S. , Dziuk P. J. , Norton H. W. 
Published: February 2005

AbstractThe time of intrauterine migration and spacing of embryos was determined in 36 gilts with one oviduct occluded, and in 48 gilts with one ovary. Embryos could enter the uterus from one oviduct only. Uteri of seven pregnant gilts were examined on each of days 6, 7, 8, 9, 10, 11, 12, 13, and 15 of gestation. Migration of embryos from one horn to the other usually occurred first on day 8 or 9. The uterus was occupied completely by day 15. Rate of migration and distribution of embryos was not affected by number of embryos, number of corpora lutea, or by uterine length. Uterine length did not change between days 6 and 15. Bilateral ovariectomy after breeding was associated with arrested growth of embryos, a decreased rate of embryo migration and a reduction in uterine length.
Ultrastructure of neurons in the arcuate nucleus of the rat
Authors: Etcheverry Guillermo Jaim , De Iraldi Amanda Pellegrino 
Published: February 2005

AbstractIn the arcuate nucleus of the normal rat there are two types of neurons. One of them is characterized by a dense cytoplasmic matrix, dilated endoplasmic reticulum cisternae and well developed Golgi complexes; the other cell type by a paler overall appearance. In both of them granulated vesicles of about 1000 Å in diameter with a core of variable density are present. The frequent association between these vesicles and the Golgi complex suggests that they are formed in relation to this organoid. The presence of lysosomes and multivesicular bodies and their close relationship with granulated vesicles is analyzed.The neuropil of the nucleus is constituted by axons, dendrites and glial processes. The majority of the axon profiles and nerve endings contain a mixed population of clear and granulated vesicles, the latter having a diameter ranging between 600 to 1300 Å.The finding of granulated vesicles in arcuate neurons is discussed in relation with the known monoamine content of them and the dopaminergic nature of the fibers that form the tuberoinfundibular tract. It is suggested that these granulated vesicles contain primary monoamines.
Regeneration research in the Soviet Union
Authors: Carlson Bruce M. 
Published: February 2005

AbstractOver the past 20 years Soviet research in regeneration has undergone a shift in emphasis from work on amphibians to mammals. In that period several distinct schools of thought have arisen, and often there has been considerable controversy as to the nature of certain regenerative processes. At present most mammalian tissues and organs are being studied with respect to natural regenerative capacity and means of stimulating further regeneration. The most striking results have been obtained in the areas of muscle and bone regeneration. Progress in other areas has been less spectacular. Considerable effort has been put into devising means of regenerating functional tissue from pathologically changed or irradiated organs. The field of regeneration research in the Soviet Union is quite highly organized and includes a relatively large number of workers. Progress has, to some extent, been impeded by shortages of equipment and biochemical preparations.
The survival and differentiation of fetal membranes grafted into the peritoneal cavity in mice
Authors: Avery Gordon B. , Hunt Carl V. 
Published: February 2005

AbstractFetal membranes grafted to the omentum in mice do not degenerate at a time corresponding to the normal termination of the donor pregnancy, as would be expected if a “biological clock” were matching their lifespan with that of the embryo and placenta. Neither, in our experience, did such grafted membranes form a variety of highly differentiated secondary tissues, as some authors have suggested. Rather, the fate of the various components of the membrane seemed different for each cell type. In allogeneic hosts a brisk cellular reaction occurred and the membranes were destroyed. In isogeneic hosts, the grafts was vascularized and healthy membrane‐derived structures were still present after 33 days of grafting (48 days conceptual age). Mesothelial cells remained applied to well‐preserved basement membrane, whereas visceral endoderm cells appeared to degenerate or else detach themselves and become free rounded cells with foamy cytoplasm, sometimes multinucleated. Mesodermal cells accompanying the blood vessels of the membrane probably accounted for the connective tissue stroma seen in these grafts. The normal failure of the fetal membranes to persist in situ after the termination of pregnancy may result from the resistance of the uterine lumen to grafts not having highly invasive properties, together with the general sloughing of the uterine lining which takes place after delivery.
Dynamic microscopic anatomy of the fetal liver III. Erythropoiesis
Authors: McCuskey Robert S. 
Published: February 2005

AbstractErythropoiesis was studied in the living fetal and neonatal rabbit liver in situ by in vivo microscopic and routine histologic methods. The results demonstrated in life: (1) that fetal hepatic erythropoiesis occurs extravascularly; (2) that individual erythroid cells late in their development pass by diapedesis from the extravascular compartment into the sinusoids; (3) that diapedesis occurs through the sinusoid wall in all parts of the hepatic lobule and possibly may be through the cytoplasm of the endothelial cells; and (4) that the sinusoid sphincters, the flow of blood through the sinusoids, and the intravascular adhesion of maturing erythroid cells to the endothelium affect the length of time that the erythroid cells remain in the sinusoids prior to their release into the peripheral circulating blood.
A study of some histochemical and phagocytic reactions of the sinus lining cells of the rabbit's spleen
Authors: Snodgrass Michael J. 
Published: February 2005

AbstractA correlative study using several techniques known to demonstrate reticuloendothelial (RE) cells was undertaken to determine whether the splenic sinus lining cells of the white rabbit should be classified with that group of cells. Like RE cells throughout the animal body, these cells can be demonstrated by silver precipitation techniques, that is, they are metalophilic. They show strong non‐specific esterase enzyme activity but only very slight acid phosphatase enzyme activity and sparingly phagocytize intravenous India ink (carbon), chlorazole black E, and saccharated oxide of iron. These results indicate these cells are reticuloendothelial in nature but are quite inactive when compared to RE cells of the red pulp cords.
The nictitating membranes of primates
Authors: Arao Tatsuyoshi , Perkins Edwin 
Published: February 2005

AbstractOf 22 species of subhuman primates examined, 21 have a well developed nictitating membrane; it is vestigial only in Pan satyrus/troglodytes. The sizes of membranes range from those that cover only one‐tenth of the eye (Gorilla gorilla) to those that extend over the entire eye (Perodicticus potto and Arctocebus calabarensis). Nictitans, best developed in the lower primates, have a free border that is generally heavily pigmented. With the exception of Galago crassicaudatus, all prosimians studied have a membrane that contains a cartilaginous band; cartilage is also present in Cacajao rubicundus, Cebus albifrons, and Saimiri sciureus. The outer surface of the nictitans of all species of anthropoids has mucous glands; that of the prosimians has few of them. Serous glands are present only in the Lorisoidea; in anthropoids serous glands are confined to the adjacent conjunctiva. Mast cells occur with great frequency in prosimians. Elastic fibers are better developed in anthropoids. Muscle fibers are present only in the nictitating membranes of Lemur monoz and Callithrix aurita. Vellus hairs grow on the outer surface of the nictitans in many of the species studied.
The allantoic placenta of the vampire bat (Desmodus rotundus murinus): A reinterpretation of its structure based on electron microscopic observations
Authors: Björkman Nils H. , Wimsatt William A. 
Published: February 2005

AbstractThe chorioallantoic placental barrier of the vampire bat Desmodus rotundus murinus has been studied by electron microscopy. The following elements of the placental labyrinth separate the maternal and fetal circulations: (1) An initially continuous but later discontinuous maternal endothelium, (2) a discontinuous amorphous interstitial membrane, (3) syncytial trophoblast, (4) cytotrophoblast intermingled with a few light cells, (5) a thick basement membrane, (6) mesenchyme, and (7) fetal endothelium. The mesenchyme as a constituent of the barrier is partly bypassed by fetal capillaries. The maternal endothelial cells diminish in number as gestation proceeds, but the interstitial membrane persists. Cytoplasm from the syncytium penetrates defects in the membrane, replaces the lost maternal endothelium, and forms membrane bounded compartments above the former interstitial membrane, which becomes now mainly an intrasyncytial structure. The endotheliochorial relationship originally existing is gradually converted into a hemodichorial condition, if the continuing presence of the amorphous membrane of initially maternal origin is disregarded. The definitive structure of the allantoic placental barrier thus differes somewhat from the organization earlier proposed by one of us on the basis of light microscopic observations. The persistence of an intrasyncytial lamina derived at least initially from maternal tissue is a novel if not a unique feature of the placenta in higher Chiroptera.
Preimplantation stages of baboon embryos (Papio sp.)
Authors: Hendrickx Andrew G. , Kraemer Duane C. 
Published: February 2005

AbstractThirteen baboon embryos were collected at various times before implantation and classified into three stages of development, based on a correlation of morphological development and estimated fertilization age. The fertilization age was estimated by designating the day of mating and/or expected ovulation as day zero. Females were mated with males of proven fertility three days before the estimated onset of perineal deturgescence based on previous cycles. All stages were collected by using an in situ flushing procedure or by flushing the excised oviduct and/or uterus.The two zygotes comprising stage I were recovered from the oviducts on the first day after fertilization. Stage II contains six embryos ranging in development from four to aproximately 32 cells. They were recovered from the oviducts and uteri on the second to the sixth days after fertilization. Stage III consists of five embryos in the free blastocyst stage which were recovered from uterine washings on the fifth to the eighth day after fertilization. One free blastocyst was recovered with the zona pellucida intact, another was in the process of shedding the zona pellucida, and two blastocysts were recovered after the zona pellucida had been shed. The fifth blastocyst was lost before it could be studied in detail.
Responses of livers of mice to type of dietary fat
Authors: Wicks Mark S. , Ball Carroll R. 
Published: February 2005

AbstractNine edible oils or fats (hydrogenated coconut, cod liver, Wesson, linseed, olive, butter, lard, corn and cocoa‐butter) were fed to Swiss albino mice for 90 days to study the effects of saturation, chain length, and essential fatty acid content on the liver. The specific oil or fat (selected for ranges in above variables) was used as the diet fat in a high‐fat (28%), low‐protein (8%), hypolipotropic diet. Half the animals received choline chloride (2 gm/100 gm) as a lipotropic supplement.Within the supplemented groups, ceroid pigment was limited to livers of mice fed cod liver oil. Among the unsupplemented groups, production of ceroid varied with the iodine value (IV) of the diet fat. Fats with low IV produced no pigment; intermediate IV showed ceroid distended Kupffer cells distributed throughout the hepatic lobule, while large, acellular, vacuolated masses of ceroid resulted from fats with highest IV.Hepatic liposis was minimal in supplemented groups; maximal in unsupplemented groups. Hepatic stroma was within normal limits in all groups. Production of ceroid pigment appeared to be unrelated to degree of liposis or fibrosis.
Plasma cells in human gingiva: An electron microscope study
Authors: Weinstock Alfred 
Published: February 2005

AbstractThe fine structure of plasma cells in clinically healthy human gingiva has been investigated. The cytoplasm was occupied by a profuse rough endoplasmic reticulum, consisting of parallel and circular arrays of cisternae, which contained a moderately dense, flocculant material. Attached to the cisternal membranes were ribosomal configurations in spirals or coils. Round and elongated mitochondria were distributed in a perinuclear fashion and possessed cristae with sharp angulations along their membranes. A well developed Golgi complex was situated in the cytocentrum adjacent to the nucleus and consisted of three major elements: smoothmembraned saccules with characteristic terminal expansions, vacuoles, and dispersed vesicles. These elements frequently contained material of considerable electron‐opacity. Transitional elements (see text) were observed on the endoplasmic reticulum immediately adjacent to the Golgi complex, and evaginations or “blebs” occurred at variable points along their membranes. Cytoplasmic dense bodies in various stages of development were intimately associated with the Golgi. Small forms were membrane‐bound and contained a fine, dense, granular material. Large bodies were also limited by a unit membrane and demonstrated a crystalline internal structure with a major and minor periodicity of about 100 Å. Russell bodies, as described by previous investigators, were not encountered. It is suggested that the dense bodies are formed by the Golgi complex, and may represent lysosomes or non‐hydrolytic enzyme storage units.
Some anatomic factors having to do with urinary continence
Authors: Roberts Walter Herbert B. , Hunt Guy Marion , Henken Herbert William 
Published: February 2005

AbstractThe levator ani acts synergistically with the sphincter urethrae in the voluntary control of micturition by stretching the urethra and thus narrowing its lumen. Further, because of the high origin of its anterior fibers it pulls the trigonal area of the bladder forward and angulates the urethra. The urogenital diaphragm also is pulled upward and made more horizontal. The concept that the levator compresses the urethra against the symphysis is not valid.The fibers of the urethral sphincter decussate around the urethra but few if any completely encircle it, even in the male. When it contracts it elevates the perineum slightly but its principal function is to convert the urethral configuration into a horizontal slit. In the male the sphincter conforms somewhat to the apex of the prostate so that it is concave as seen from above and is not the strictly horizontal structure so often portrayed. An internal urethral sphincter is present and may be well defined.The visceral pelvic fascia, in particular the anterior component of the uterovaginal fascia, which is the pubocervical fascia of the gynecologist, has much smooth muscle in it. This muscle, acting in line with the pelvic axis, would not elevate the trigonal area or the urethrovesical junction but would exert traction on the urethra, narrowing its lumen. It would thus help maintain involuntary control.The nerve supply of the above structures is considered briefly.
A study on the radial supply of the human brachialis muscle
Authors: Ip M. C. , Chang K. S. F. 
Published: February 2005

AbstractThe fate of the radial nerve in the human brachialis muscle, a subject of dispute regarding its frequency of occurrence and nature of innervation, was studied in eight pairs of this muscle. A constant occurrence of radial supply to the brachialis muscle was found. With the exception of two cases which were discarded on account of defects, all brachialis of the sample definitely showed motor as well as sensory innervations by the radial nerve in addition to the major supply by the musculocutaneous nerve. The number and regional distribution of spindle capsules were also determined in all cases. A complete analysis in one of them showed that 7% of the spindle population in the entire muscle were supplied by the radial nerve and that their distribution was confined to the deep lateral quadrant for an extent about half of the muscle length. The probable dorsal origin of this muscle was discussed.
Lymphomyeloid organs of amphibia. III. Antibody synthesis and lymph glands in larval bullfrogs
Authors: Cooper Edwin L. 
Published: February 2005

AbstractBullfrog larvae with lymph glands removed failed to synthesize antibodies to BSA but they rejected skin allografts normally. Tadpoles with unilaterally removed lymph glands had antisera with detectable titers equivalent to unoperated animals. Lymph glands are composed of macrophages which line sinusoids interposed between cords of lymphoid cells.
Direct adrenergic innervation of a teleost melanophore
Authors: Jacobowitz David M. , Laties Alan M. 
Published: February 2005

AbstractThe possibility of sympathetic innervation to melanophores in fish was investigated using a catecholamine histochemical fluorescence method. Catecholamine‐containing fibers were observed to be in close anatomic proximity to the conjunctival and dermal melanophores of the cunner (Tautogolabrus adspersus). It is suggested that the catecholamines released from these adrenergic fibers are capable of causing aggregation of pigment with blanching of skin color.
Observations on the fine structure of peripheral nerve myelin
Authors: Napolitano Leonard M. , Scallen Terence J. 
Published: February 2005

AbstractThe incorporation of digitonin 0.2% w/v in cacodylate buffered glutaraldehyde reduces the amount of cholesterol extracted in the dehydrating (lipid extracting) solutions. The fixative enhances membrane structure and results in the preservation of a double minor period in peripheral myelin. The periodicity obtained is in agreement with those derived from x‐ray diffraction studies.