bluuebunny/crossref_metadata_2025_split huggingface dataset:
Species differences in egg transport in response to exogenous estrogen
Authors: Greenwald Gilbert S. 
Published: February 2005

AbstractThe effect of exogenous estrogen on tubal transport of ova was determined in the guinea pig, hamster, mouse, rabbit and rat. The animals were given a single injection of estradiol cyclopentylpropionate (ECP) shortly after mating. The dose of ECP required to interrupt pregnancy in 80% or more of the animals was as follows: guinea pig (10 μg); hamster (25 μg); mouse (1 μg); rabbit (50 μg); rat (10 μg). Acceleration of egg transport through the oviduct occurred after the following doses of ECP: guinea pig (50–100 μg); hamster (100 μg); mouse (1 μg and above); rabbit (25 μg); rat (10 μg and above). Hence, the amount of estrogen which accelerates egg transport in the guinea pig and hamster is considerably higher than the dose which interrupts pregnancy.Retentionof ova for longer than the normal period of tubal passage (tube‐locking) resulted from the following doses of ECP: guinea pig (250 μg); hamster (250 μg); mouse (1 μg); rabbit (100 μg); rat (no dose). In the species in which ova were tubelocked, the majority of eggs were located at the ampullary‐isthmic junction rather than the utero‐tubal region of the oviduct.Tube‐locking of ova was never observed in the rat; ECP always caused premature entry of eggs into the uterus and eventual expulsion per vaginam. For example, eggs passed through the cervix by 12 hours after the administration of 250 μg ECP at day 1 of pregnancy.
An ordered complex of filaments surrounding the lipid droplets in developing adipose cells
Authors: Wood Eunice M. 
Published: February 2005

AbstractExamination of the lipid‐cytoplasm interface of the weakly osmiophilic fat droplets in developing adipose cells from chick bone marrow reveals that the lipid does not lie free in the cytoplasm, nor is it bounded by a membrane, but instead is encompassed by a highly ordered complex of small, 80 Å thick, filaments.In oblique sections, superimposition of the images of adjacent filaments results in a more or less continuous line which resembles a membrane. Perhaps this view of the system of filaments, in sections where heavily osmicated fat had retracted slightly from the interface, is responsible for reports that the lipid in adipose cells is enclosed by a membrane.It is suggested that a similar system of filaments may be visualized in adipose cells of other species after extraction of the strongly osmiophilic fat which obscures details at the surface of the lipid droplets.Although the true functional significance of the filaments is not yet known, the morphological evidence alone suggests that they may provide support for the lipid inclusions. An interpretation of the geometry of the filaments, consistent with the present evidence, is presented.
The absorptive activity of ameloblasts during the maturation of enamel
Authors: Reith Edward J. , Cotty Val F. 
Published: February 2005

AbstractThe activity of ameloblasts during the maturation of enamel was investigated by means of autoradiography. Young rats were given daily injections of radioactive sulfur. Injections were started when the rats were five days old and continued until some of the rats were 12 days old. Developing teeth were removed at different times and prepared for autoradiography.In every specimen that was examined, silver grains were found over enamel that was adjacent to tall, secretory ameloblasts. These cells have been identified as being engaged in matrix formation.At the end of matrix formation, the tall ameloblasts become structurally reorganized, and the reorganized cells now act on the enamel as it matures. Despite the fact that the animals receive daily injection of labeled sulfur, the silver grains over the maturing enamel decrease and silver grains are observed over the cytoplasm of the shortened ameloblasts.It is concluded therefore that one of the activities of the reorganized (transporting) ameloblasts is to remove sulfur or a sulfated compound from the enamel during its maturation.
Age and the cell cycle of the mouse colonic epithelium
Authors: Thrasher Jack D. 
Published: February 2005

AbstractThe colonic progenitor population has been investigated in four age groups of male Swiss albino mice utilizing tritium thymidine and autoradiography. The duration of the progenitor cell cycle and its component phases as well as the DNA synthetic index were determined for each age group following sequential sacrifice of the experimental animals.Analysis of the kinetics of metaphase labeling revealed that the mean duration of the cell cycle lengthens with age, whereas S (about 7.8 hours), G2 and M remain relatively constant. Estimates of the cell cycle from the ratio of the S‐phase duration to the DNA synthetic index also demonstrate an increase with age, although the values derived from this method do not agree with those based on metaphase labeling.Determination of the DNA synthetic index disclosed a decrease in the percentage of labeled cells with increasing age. Thus, the prolongation of the mean duration of the cell cycle apparently results from an increase in the G1‐phase.
The relationship of histochemically reactive histidine to histidase activity in the epidermis of growing rats
Authors: Reaven Eve P. , Cox Alvin J. 
Published: February 2005

AbstractThe histochemical localization of histidine in the epidermis and its relationship to skin histidase activity was described in rats varying in age from 17 days post‐coitum to 240 days post partum. In the fetal rat, the earliest histidase activity developed coincidentally with the first appearance of stainable histidine in the keratohyalin granules. In the neonatal period, histidase activity increased rapidly to several times the normal adult levels, corresponding in time to a period when the epidermal histidine‐containing zone was especially thick. As the thickness of this zone varied in subsequent periods during the life of the rat, parallel changes were observed in epidermal histidase activity suggesting the existence of a close interrelationship of histidine and histidase at the site of epidermal keratinization during the maturation of normal skin.
Studies on the thymus of the mammal XV. Sites of aminopeptidase activity in the thymus of the mouse
Authors: Smith Christianna 
Published: February 2005

AbstractSites of aminopeptidase activity in the thymus of the mouse were compared in material incubated in L‐leucyl‐beta‐naphthylamide and in L‐leucyl‐4‐methoxy‐beta‐naphthylamide hydrochlorides as substrates. Sites of activity were most clearly demonstrated in frozen sections, postfixed in cold acetone, incubated in L‐leucyl‐4‐methoxy‐beta‐naphthylamide hydrochloride with Naphthanil Diazo Blue B and mounted in glycerogel.In thymuses of young mice, septa, medullary arteries and arterial capillaries were most strongly stained. Cortical lymphocytes and most medullary lymphocytes lacked aminopeptidase activity. In older mice, the high reactivity of the medulla contrasted sharply with the mostly unreactive cortex. In the medulla, the walls of the blood vessels, mesenchymal reticular cells and lymphocytes in the region of blood vessels were reactive. In the cortex, capsule, septa, and arterial capillaries were reactive; mesenchymal reticular cells, weakly so, and lymphocytes, unreactive. It would appear that much of the activity demonstrated by biochemical methods applied to thymic homogenates is a measure of reactive blood vessels and medullae. The general reaction of the medulla and the presence there of scattered, highly reactive cells lends added weight to the conclusion that the metabolic activities within the medulla are not the same as in the cortex.
The histological fine structure of perineurium
Authors: Burkel William E. 
Published: February 2005

AbstractExtraocular muscles of the rat possess numerous nerves suitable for the study of fine structure. In these muscles, small nerves made up of one to ten myelinated and unmyelinated nerve fibers are surrounded by two or three layers of perineurium. The perineurium is arranged in concentric sleeves, each one cell thick. Continuous boundary membranes separate the perineural sleeves from the epineural and endoneural tissue space, but the boundary membranes may be spotty or absent between individual sleeves. The presence of boundary membranes around perineural cells distinguishes them from nearby fibroblasts which lack similar membranous investment. Tight intercellular junctions join the cells comprising each sleeve so that the nerves are completely ensheathed in perineurium. The number of sleeves decreases as the nerve becomes smaller, either by the termination of the innermost sleeve or by the loss of a sleeve as the nerve branches. The last sleeve ends shortly before the termination of the nerve. The perineurium is thus open‐ended peripherally and, at these places, the epineurium and endoneurium are continuous. Continuities between the epineurium and endoneurium also exist at the entrance and exit of blood vessels supplying the nerve and at points where reticular fibers pierce the perineurium. These structural features correlate well with the action of the perineurium as a diffusion barrier and as a pathway in the transmission of infections.
Comparative study of human internal iliac artery based on adachi classification
Authors: Roberts W. H. , Krishingner Gene L. 
Published: February 2005

AbstractThis study is based upon a dissection of 167 pelvic halves of Caucasian bodies. The distribution of the four major types, as based upon the Adachi classification, corresponds closely to that of the Western populations. The composite group has a distribution almost identical with the Japanese population studied by Adachi. No instances of the rare Type V were encountered. One unusual specimen which we have designated as Type VI is described.
Developmental relationship between the appearance of lymphocytes and lymphopoietic activity in the thymus and lymph nodes of the fetal cat
Authors: Ackerman G. Adolph 
Published: February 2005

AbstractThe origin and development of the lymphocyte populations of the thymus and the lymph nodes have been studied in the fetal cat. Fetuses ranging in age from 25 days (16 mm) to 50 days (98 mm) of gestation have been examined following formol‐sublimate‐acetic acid fixation, parlodion‐paraffin embedding and subsequent staining with toluidine blue, hematoxylin‐eosin and periodic acid‐Schiff methods.These studies have shown an occasional lymphocyte in the primitive lymph nodes as early as the thirtieth day of gestation. A number of small‐ and medium‐sized lymphocytes are scattered randomly in the mesenchymal condensation of the developing lymph nodes by 33 days. Lymphocyte proliferation proceeds relatively slowly, and morphological evidence suggests that lymphocytes appear to develop from the mesenchymal or reticular cells of the developing lymph nodes without the intermediate formation of lymphoblasts. In the thymus, the first lymphocytic cells formed are lymphoblasts. These cells appear initially between 31 and 33 days. Lymphoblastic transformation is not generalized until the thirty‐fifth day; at this time, an occasional medium‐sized lymphocyte is evident and vascularization of the thymus begins. Development proceeds rapidly and the thymus is filled with medium‐sized and small lymphocytes by 40 days. At this time, large clusters of small lymphocytes are evident in the capsular connective tissue, and these cells soon enter lymphatic vessels located in the capsular connective tissue.These observations indicate that the initial appearance of lymphocytes in lymph nodes precedes the appearance of lymphocytic precursors (lymphoblasts) in the thymus by 1–2 days and the development of lymphocytes in the thymus by approximately five days. Therefore, the early lymphocyte population in the lymph nodes is not dependent upon the dissemination of thymic lymphocytes or their precursors. Thymic lymphocytes, however, may contribute to the lymphocyte population of the lymph nodes at later stages of fetal development, after vascularization of the thymus and after the formation of lymphatic vessels in the capsule.
Prolonged individuality of the accessory contribution to the vagus: A peculiarity of the pig
Authors: Safanie A. H. 
Published: February 2005

AbstractThe bulbar and spinal components of the accessory nerve of the pig are thoroughly integrated in a common trunk at the jugular foramen. The fibers of bulbar origin separate from this trunk to form the internal ramus. The latter is especially demonstrable in the pig, since it is independent over a considerable distance in the upper part of the neck before joining the vagus. As far distally as the origin of the recurrent laryngeal nerve, the efferent fibers contributed to the vagus by the accessory nerve remain histologically separate from the afferent fibers belonging properly to the vagus. Parasympathetic, branchiomotor and afferent fibers can be distinguished in the vagal trunk without the necessity of inducing selective degeneration by supranodose vagotomy.
The skin of the whale (Balaenoptera physalus)
Authors: Giacometti Luigi 
Published: February 2005

AbstractSkin specimens were obtained from every representative region of the body of an adult Finback whale (Balaenoptera physalus) and examined by means of various histochemical and histological techniques. The following characteristic features were found:The epidermis is exceedingly thick over the general body surfaces and varies from a maximum of 3.0 mm over the ventral surface to 2.5 mm on the back.The complex understructure of the epidermis has rete ridges oriented to the craniocaudad body axis.The papillary layer of the dermis has long and pointed papillae which are wedged into the epidermis.The sensory cutaneous nerve endings demonstrated by silver impregnation and cholinesterase consist predominantly of small Vater‐Pacini corpuscles situated in the higher level of the dermis.The intricate blood capillary network, positive for alkaline phosphatase is encased in the dermal papillae.There are no hair follicles, sebaceous and sweat glands.
Changes in the anteroposterior dimensions of the human male skull during the third and fourth decade of life
Authors: Kendrick George S. , Risinger Hubert L. 
Published: February 2005

AbstractA cephalometric radiographic appraisal of the anteroposterior skull growth which occurs during a one‐year interval was made on 71 caucasoid males at the Baylor University College of Dentistry, Dallas, Texas. The subjects were from 22–34 years of age. The dimensions assessed were the anterior cranial depth, the posterior cranial depth, upper facial depth, middle facial depth and lower facial depth. A significant increase was shown to occur in all the dimensions over a period of one year except that of the lower facial depth. It was concluded that skull growth does occur in male adults after the age generally accepted as that of maturity.
Fine structure of nerve terminals in the human gut
Authors: Pick Joseph , De Lemos Carmen , Ciannella Arnold 
Published: February 2005

AbstractAn electron microscopical investigation was made of neuronal terminals in operatively removed human duodenum and jejunum. No intraepithelial neuronal elements were found. The lamina propria mucosae, submucosa and muscular layer possessed, in addition to large bundles of unmyelinated nerve fibers, small ones consisting of three or four axons wrapped by infoldings of one Schwann cell. Some of these axons were light; others contained mitochondria and clear vesicles measuring 200–500 Å across. Still other axons had dense‐cored vesicles with a diameter ∼ 700 Å. The plasma membranes of vesiculated axons were not thickened and only in part invested by the Schwann cell, but were covered by a basement membrane. Such profiles were interpreted as nerve terminals, and were separated from fibers of the muscularis mucosae, bases of epithelial cells and submucous capillaries by interspaces measuring 5,000–6,800 Å. The gap between neuronal terminals and smooth muscle in the muscular wall was smaller (900 Å, more often 1,500–3,000 Å). The myenteric plexus contained nerve bundles consisting of the usual axons and of preterminals; some of the latter contained small clear vesicles, others predominantly larger granulated vesicles, and still others a mixture of both types of vesicles. The similarities and differences of neuronal terminals occurring in animals and in man were pointed out. The significance of the findings of this study was discussed in the light of current concepts of the physiology of autonomic nerve transmission.
Annulate lamellae in cat lateral geniculate neurons
Authors: Doolin Paul F. , Barron Kevin D. , Seber Almera 
Published: February 2005

AbstractAnnulate lamellae occur in the perikaryon and dendritic extensions of lateral geniculate body neurons in the adult cat. The perikaryal arrays are 3‐dimensional membranous stacks composed of parallel rows of agranular, flattened cisterns alternating with amorphous jinear parallel densities. Each lamella contains periodic constrictions and annuli spanned by a diaphragm‐like condensation. Tenuous threads interconnect the lamellae at the annular rims with the parallel densities located midway between successive lamellae. Terminal ends of lamellae are sometimes dilated and are coextensive with cytoplasmic granular endoplasmic reticulum. Individual components of dendritic configurations are repeated at shorter intervals than their major somal counterparts, and the midregion densities are absent.Annulate lamellae occur at a distance of 2 μ or more from the nucleus. Their origin remains undetermined. The lamellar structures are relatively resistant to marked changes displayed by cytoplasmic membranes in neurons undergoing atrophic degeneration.
Electron microscopic observations of dense bodies in parietal cells of the hamster (Mesocricetus auratus)
Authors: Winborn William B. , Bockman Dale E. 
Published: February 2005

AbstractParietal cells of the fundic region of the stomach in the golden hamster (Mesocricetus auratus) contain numerous electron‐dense bodies which have different morphologies. Granular dense bodies are the most common, with lamellar and crystalloid forms less frequent; angular dense bodies with bizarre profiles are seen rarely. In random counts on sections of identical thickness, profiles of electron dense bodies averaged five per cell section and as many as 20 to 30 per cell section are found occasionally. These structures bear a striking resemblance to lysosomes described by other workers. Electron microscopic studies were made of frozen sections of the stomach incubated in Gomori's substrate mixture. Results indicated a discrete localization of acid phosphatase reaction products within the dense bodies. Studies on glutaraldehyde fixed material without further fixation in osmium tetroxide demonstrate features not readily discernable with standard osmium fixation.
Development of cortical granules and the cortical reaction in rat and Hamster eggs
Authors: Szollosi Daniel 
Published: February 2005

AbstractThe origin of cortical granules is described in hamster and rat oocytes by electron microscopy. They occur first near vesicular elements of small Golgi complexes. Most of these Golgi complexes lie peripherally, but in the rat, there are a few also near the germinal vesicle. The granules arise at the concave surfaces of the Golgi complexes and apparently migrate to the cell membrane where they become aligned in close association to it. Cortical granules are found in the cytoplasm of the first polar body but not in the second. The cortical reaction, initiated by sperm attachment, consists of a gradual fusion of the membranes surrounding cortical granules with that of the egg plasma membrane and eversion of their contents into the perivitelline space. Occasionally, in the rat several granules fuse laterally to form larger cortical “caverns.” Such caverns have a single opening to the perivitelline space. The origin and extrusion of cortical granules can be compared usefully with the synthesis and merocrine‐type secretion of proteinaceous granules or mucoid droplets.
Orthogonal arrays of Microtubules in flattening cells of the epidermis
Authors: Branson Roger J. 
Published: February 2005

AbstractMicrotubules, 210–230 Å in diameter and many microns in length, with an associated “clear zone” around them, 450–550 Å in diameter, are demonstrated in large numbers in cells of the Stratum Granulosum of newborn rat epidermis. Few microtubules are found in the uppermost portion of the Stratum Granulosum nor are they found above this layer in the Stratum Corneum. Few microtubules are found in the germinal cells of the epidermis. Upon entering the Stratum Granulosum, cells undergo shape changes involving elongation and flattening. Microtubules have elsewhere been implicated in whole cell movement and in the movement of portions of cytoplasm, including specifically cell elongation and the related functions of maintenance of asymmetric cell shapes and projections. Evidence is presented here in support of the hypothesis that microtubules are the basic cytoplasmic structure responsible for this motility. Two cortical arrays of microtubules, parallel and orthogonal in orientation, are demonstrated at different stages of cell flattening in epidermis. If the mode of action of microtubules is undulation and resulting “intracytoplasmic peristalis,” these orthogonal arrays represent a mechanism for the formation of the shape of squamous cells. The similar orientations of microtubule populations in many cells would seem to indicate that microtubule undulation and the resulting interaction between neighboring cells accounts for the transmission of axes of orientation between cells.
Muscle growth in selected lines of muscular dystrophic chickens
Authors: Holliday T. A. , Julian L. M. , Asmundson V. S. 
Published: February 2005

AbstractGrowth of four muscles was studied in four lines of homozygous dystrophic chickens selected for high or low fat content of pectoralis muscles, or for early or late onset of disability. The light (“white”) pectoralis, supracoracoideus and biceps brachii and the dark (“red”) adductor muscles were studied. Growth characteristics were compared to a randomly mated dystrophic line and to normal chickens. Significant differences in muscle size occurred between lines but all dystrophic lines underwent the same sequence of events: gross hypertrophy of the white muscles during the first few weeks of life, followed enventually by gross atrophy. The dark adductor muscles did not differ consistently from normal. Hypertrophy was accompanied by increased protein (or fat‐free dry matter) and water content. Atrophy was accompanied by increased fat content. Selected lines exhibited greater uniformity and greater extremes of hypertrophy or atrophy than occurred in the random line.