bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selective staining of chromatin in hematogenous lymphocytes in nodes
Authors: Tompkins Edna H. 
Published: February 2005

AbstractLymphocytes with “atypical nuclei” have been shown to increase in lymph nodes during afferent drainage ('64). This report concerns the selective staining of these nuclei with the MBL technique (exposure of methylene blue stained sections to alcoholic Lugol's solution).Comparisons with other techniques, together with suitable extractive procedures, lead to the conclusion that chromatin throughout the hematogenous series of lymphocytes is subject to two general forms of selective response to the MBL technique during lymphatic drainage. These are distinguished by differences in: 1, time required for staining with the iodine solution; 2, morphology; and 3, ease of dedifferentiation.The first response (unpatterned, coarse, intranuclear granules) occurs in older hematogenous lymphocytes only, after brief exposures, and varies in ease of dedifferentiation.The second response (intranuclear, reticulated figures) occurs in hematogenous lymphocytes of any age, after long exposures to iodine, and is slow to dedifferentiate. The figures uniformly conform to the reticular patterns of inter‐ and prophase, and become condensed as cell volumes decrease.The findings show that fluctuant, dynamic relationships exist among hematogenous lymphocytes in nodes :‐ unidentified factors become associated with their chromatin and result in selective nuclear staining; the chromatin becomes restricted to reticular positions and mitoses cease; cell volumes shrink progressively; nucleo‐cytoplasmic ratios increase; and intranuclear structures become condensed. Yet evidences of degeneration are not found.
Mucosal cellular populations and distribution in the normal canine stomach
Authors: Ritchie Wallace P. , Barzilai Ami , Delaney John P. 
Published: February 2005

AbstractMucosal cellular populations and glandular thickness in the corpus of the canine stomach was assessed in 30 dogs. The average number of mucous neck cells per “swath” of full thickness mucosa over a width of 0.223 mm was 41 (S.E. ± 2.09), of parietal cells, 95 (S.E. ± 8.71), of chief cells 205 (S.E. ± 12.63). The average glandular thickness was 557 μ (S.E. ± 24.71).The distribution of cells in the stomachs of four additional dogs was determined. More mucous neck cells were noted in the glands of the juxta‐antral and cardiac zones than in those of the corpus. Few parietal and chief cells were noted in the cardiac zone. In the corpus, however, these cells were abundant and evenly distributed.The data presented permit calculation of the total gastric mucosal cellular population of the stomach from an “average” 15 kg dog. The acid‐pepsin secreting area has a volume of 35 cm3, and therefore contains 4.3× 108 parietal cells, 7.2 × 108 chief cells, and 1.4 × 108 mucous neck cells.
Initiation of vagal control of heart rate in the embryonic chick
Authors: Legande Mary C. , Paff George H. , Boucek Robert J. 
Published: February 2005

AbstractThe objective was to determine on what day of development the vagal complex i.e., dorsal motor nucleus in the floor of the fourth ventricle, vagus nerve and post synaptic neuron assumes functional control of the heart rate in the chick embryo. Adapting a technique used by Armstrong ('35) for the Fundulus embryo, 0.003 ml of Tyrode solution containing 0.03 μg of acetylcholine was injected into the fourth ventricles of 16 chick embryos at four days of age, 25 at five and 15 at six days of age. Heart rates were taken before and after injection.Analyzed statistically no significant changes in heart rate occurred following injection of acetylcholine into four day embryos but at five days a significant average drop from 106 to 95 beats per minute occurred. The same was true in six‐day‐old embryos where the average drop in rate was from 108 before to 84 after injection. As proof that the acetylcholine injected into the brain ventricle acted by stimulating the vagal mechanism and not by diffusing into cerebral blood vessels and being carried to the heart we found that corresponding amounts of acetylcholine injected into omphalomesenteric veins had no significant effect on heart rate. Also 0.003 ml of plain Tyrode solution injected into the fourth ventricle elicited no significant response. These observations justify the conclusion that the vagal pathway to the heart becomes functional between five and six days of development in the chick embryo.
Light and electron microscopic studies of pigment in human and rhesus monkey substantia nigra and locus coeruleus
Authors: Moses Harold L. , Ganote Charles E. , Beaver David L. , Schuffman Shirley S. 
Published: February 2005

AbstractNeuromelanin pigment of the substantia nigra and locus coeruleus from nine human autopsy cases and from four rhesus monkeys was studied. Melanin and lipofuscin pigments from other anatomical sites were also observed for the purpose of comparison with the substantia nigra‐locus coeruleus pigment. Ultrastructurally, the neuromelanin pigment granule was composed of three distinct components. The first was a finely granular, medium dense matrix which occasionally had linear configurations very similar to those of neuronal lipofuscin granules from human cerebral cortex. The second component was a very dense, coarsely granular material which appeared to to be deposited on the finely granular matrix. This very dense component was apparently the reducing part of the neuromelanin granule, as it was the site of localization of silver deposits in formalin‐fixed tissue which had been stained with diamine silver prior to post‐osmication and examination in the electron microscope. No evidence of silver reduction was noted in lipofuscin pigment. The third component of the neuromelanin granule was a lipid globule which was not preserved in glutaraldehyde or formol‐permanganate fixed tissue. A lipid globule was not observed in melanin granules from the skin, eye, or pia mater.
Cyclic changes in the squamo‐columnar junction of the mouse cervix uteri
Authors: Graham Charles E. 
Published: February 2005

AbstractThe histological structure of the squamo‐columnar junction of the cervix uteri of mice was studied during the estrous cycle, pregnancy, lactation, and in ovariectomized and estrogen‐stimulated animals. In the absence of endogenous or exogenous estrogen, there was no clear demarcation between the squamous and the columnar epithelium; the epithelium in the zone of transition resembled types previously described in the human cervix that have been regarded as evidence of a metaplasia of columnar to stratified epithelium. However, in the mouse, estrogen stimulation caused the disappearance of the transitional zone so that an abrupt junction resulted. It was concluded that the type of junction is controlled by estrogen, and that the stratified epithelium of the transitional zone may differentiate to produce either keratinized cells or cells of uterine type at its surface.
Internal hernia of embryological origin
Authors: Roberts Walter H. , Dalgleish Arthur E. 
Published: February 2005

AbstractAn anatomical specimen is described in which a considerable part of the small bowel had, apparently, in its return to the abdomen during fetal development invaginated the descending mesocolon and that of the left half of the transverse colon, thus producing a large internal hernia. The ascending branch of the left colic artery and the inferior mesenteric vein were in the neck of the sac, anterior to the loops of bowel entering and emerging from the sac. These relationships were obscured by the fact that there was a broad adhesive band extending from the mesentery of the free loops of small intestine to the descending colon, thus bridging over the vessels. The relationships referred to and as shown in the drawings, which include a cross‐sectional view, would indicate that the mechanism of production of the hernia was as suggested and that there were in fact four layers of peritoneum in the anterior wall of the sac.
Structure and Distribution of muscle spindles in the forepaw lumbricals of the phalanger, Trichosurus vdpecula
Authors: Jones Edward G. 
Published: February 2005

AbstractNon‐nervous aspects of muscle spindle morphology were examined in 15 forepaw lumbricals of a marsupial, Trichosurus vulpecula, using serial transverse and longitudinal sections. The structure of the spindle was similar to that in other mammals with a few minor differences. One to three nuclear bag type and 2 to 16 nuclear chain type intrafusal fibers were present in all spindles. The fibers were largely distinguishable by differences in length, in diameter at all levels along the length of the spindle, and in the arrangement of their equatorial nuclear aggregations. There was, however, some overlap in that many nuclear chain fibers extended for considerable distances beyond one or both poles of the spindle capsule, and several fibers, otherwise classified as nuclear bag fibers, contained single chains of equatorial nuclei rather than nuclear bags. These findings, together with the observation that all intrafusal fibers were heterogeneous in their distribution of myofibrils, and the evidence of other studies on the innervation and histochemistry of mammalian muscle spindles, suggest that a specific functional separation of intrafusal fibers on strictly morphological grounds may not be entirely valid.The receptor population in each of nine muscles bore no consistent relation to the total number of extrafusal fibers; this appears to confirm the concept that it is the functional attributes of a muscle, rather than its bulk that determine its spindle content.
Responses of tissues from larval newts to implantation into adult hosts
Authors: Dent James Norman , Benson Don G. 
Published: February 2005

AbstractTrunk and tail parts from larvae of Triturus virdescens were implanted into pockets made in the trunk epaxial musculature of adult animals of the same species. Histological observations were made on these grafts at intervals up to 60 days and at eight months following implantation. During the first few days after implantation the small, fragile grafts were distorted and compressed by the mechanical restrictions of host tissues, but they began to increase in size and rigidity by 20 days and eventually some reached sizes that exceeded considerably those of equivalent trunk and tail parts in intact control larvae. Differential responses to the host environment were seen among the various tissues of the grafts. As growth proceeded, the proportion of cartilage and bone relative to the other tissues increased. Gut, gut derivatives, nerve cord, and kidney showed initial growth but usually underwent later degenerative changes and declined in relative mass. Muscle and connective tissue did not show degenerative changes but did not increase significantly in mass. Limb‐like protuberances and (in a single graft) a mass of well differentiated testicular tissue were seen. No metastases or infiltrating growths occurred.
The anatomy and histology of XO human embryos and fetuses
Authors: Singh Roderick P. , Carr David H. 
Published: February 2005

AbstractThirteen abortuses with a known chromosomal complement of 45 (XO) were collected. Of these, eight contained an embryo or fetus ranging in age from five weeks to four months. Various gross anatomical abnormalities were evident in the four larger specimens and these included horseshoe kidney, unicornate uterus, single umbilical artery and cystic hygroma. One specimen had bilateral cystic hygromata. In all specimens, the gross anatomical appearance of the gonad was normal and, when examined histologically, the presence of primordial germ cells could be demonstrated.Histological sections of the XO gonads were compared with sections of gonads from known XX specimens of similar ages. There was no significant difference between the XO and XX gonads up to the third intrauterine month. In the older fetuses there was a relative increase in the connective tissue of the XO gonad.The finding of germ cells in the gonads of the XO fetuses is in contrast to the findings in XO adults who usually do not have germ cells in the gonads.
The effect of phytohemagglutinin on rat thymus cells in vitro
Authors: Schwarz M. Roy , Rieke William O. 
Published: February 2005

AbstractCells obtained from the thymus glands of five strains of rats, ranging in age from five hours to five months, were cultured in the presence of phytohemagglutinin according to the method of Rieke and Schwarz ('64). In these cultures, the large and medium lymphocytes in the inoculum gave rise by mitosis to small lymphocytes. Under the influence of PHA, small lymphocytes were transformed into enlarged cells which in turn acted as precursors of small lymphocytes. However, not all small cells in the cultures nor thymic lymphocytes from newborn rats responded to this mitogenic drug. A progressive increase in responsiveness was detected as donors increased from five hours to 32 days of age.
Diagnosis of pregnancy in the squirrel monkey
Authors: Nathan Tikva S. , Rosenblum Leonard A. , Limson Genara , Nelson James H. 
Published: February 2005

AbstractDiagnostic pregnancy assessments have been carried out in 18 squirrel monkey females using Delfs' method for chorionic gonadotropin bioassay palpatory, x‐ray and other auxiliary techniques. Out of the 24 bioassay tests performed, 11 were positive (one of them weakly positive) and 13 negative. These results were confirmed by the other parallel measures, except in two cases of possible false positive reactions. No false negative results were noted. The implications of the results are discussed in terms of the sensitivity and reliability of the bioassay in the early diagnosis of pregnancy in the squirrel monkey.
Hearts and blood vessels of mice receiving cortisone and estrogens
Authors: Ashburn Allen D. , Williams W. Lane 
Published: February 2005

AbstractMice received cortisone alone or concurrently with injections of estrone or diethylstilbestrol.Cortisone alone produced a high incidence of myocardial necrosis and abscesses in hearts, livers, lungs and kidneys. Staining and culture methods showed bacteria in these abscesses. The same technics failed to show infections in the mice receiving estrogen. Unrelated to other lesions the ventricular myocardium and walls of coronary arteries often contained accumulations of fat. Following concurrent injections of cortisone and an estrogen (estrone or diethylstilbestrol) the incidence of medial hyalinization of coronary arteries was 90%–98%. Edema, hemorrhage and hyalinization were observed in the aorta. In the cortisone plus estrogen groups such mural lesions of vessels developed in the absence of bacterial infection as studied by the above methods. The same was true when such infections were prevented by penicillin. The incidence of inflammatory lesions was less in mice receiving both cortisone and estrogen than in the cortisone (alone) group. Frequency of cortisone‐induced myocardial necrosis and accumulation of myocardial fat were not altered by the estrogens.
Response of articular cartilage of dwarf mice to insulin: Electronmicroscopic studies
Authors: Silberberg Ruth , Hasler Mary , Silberberg Martin 
Published: February 2005

AbstractThe effect of insulin on the ultrastructure of articular chondrocytes was studied in young dwarf mice (dwdw) which lack pituitary eosinophiles and fail to produce STH. Within less than 24 hours, injections of insulin together with dextrose enhanced development of the endoplasmic reticulum and of the Golgi structures, stimulated the mitochondria, and accelerated and intensified glycogen formation. Dextrose alone had a similar, although less marked effect. The findings suggest a slightly promoting influence of insulin on protein synthesis and a conspicuous stimulation of carbohydrate synthesis by articular chondrocytes of hypopituitary dwarf mice thus treated. The results were compared with those obtained previously after treatment with somatotrophin, and the relationship between these two hormones was discussed.
Fine structure of the neurons of the posterior horn in the rat spinal cord
Authors: Nathaniel Edward J. H. , Nathaniel Doris R. 
Published: February 2005

AbstractThe region of the posterior horn of the spinal cord in the lumbosacral region of the rat was studied with the electron microscope. This zone contained neurons, astrocytes, oligodendrocytes and blood vessels. The neurons possessed irregular nuclei which occupied a large portion of the cell. The cytoplasm contained elaborate smooth surfaced membrane systems. The rough surfaced endoplasmic reticulum was small in amount and did not possess an orderly arrangement. Electron dense bodies were invariably found within the neurons. The morphological features, such as an extremely irregular nucleus and elaborate cisterns of smooth surfaced reticulum, indicate a well developed nucleocytoplasmic transport mechanism in the neuron. The vascularity of the area was evidenced by the presence of numerous blood vessels which generally had a perineuronal position. Pericytes were invariably found in close relationship to the endothelial cells of the blood vessels. The nucleus of the pericyte was remarkably dense. The cytoplasm of these cells was extremely attenuated and almost encircled the blood vessels.
The effect of retinol and retinoic acid on the morphology of the rat uterus
Authors: Bo Walter J. , Smith Mavis S. 
Published: February 2005

AbstractAt 20 days of age, 72 Holtzman rats were divided into six groups (10–14 rats/group) and were placed on a vitamin A‐deficient diet. The animals in groups I and II were kept intact, while the animals in the remaining groups were ovariectomized at 20–22 days of age. The rats in groups I, III and V received a dietary supplement of retinoic acid (50 μg) while the diet of the animals in groups II, IV and VI was supplemented with retinol (25 μg). In addition to the dietary supplements the animals of groups V and VI were treated with estradiol dipropionate (1 μg). The dietary supplements and hormone were given three times per week. The rats were autopsied after 15 weeks on the experiment.In the intact rats of group I metaplastic changes were observed in the luminal and glandular epithelia. With the exception of two uterine sections showing small areas of squamous metaplasia in the glands, morphological alterations of the uterine epithelia were not observed in the rats of group II. Uterine metaplasia was not seen in the rats of groups III and IV. Extensive metaplastic changes were observed in the animals of group V. The endometria of the rats in group VI were lined primarily by high columnar cells, but a few uterine sections contained small foci of stratified squamous metaplasia.The results indicate that retinol is effective in preventing the morphological changes in the rat uterus due to vitamin A deficiency.
Angiocardiographic studies of the Anuran double circulation
Authors: Angell Charles S. , Hipona Florencio A. , Novick Alvin 
Published: February 2005

AbstractAngiocardiography was used to investigate cardiovascular flow patterns in the heart and great vessels of the bullfrog and the marine toad. In the frog, these studies revealed a completely selective distribution of right atrial blood to the pulmocutaneous arches. The selective distribution is affected, in part, by the ventricular trabeculae which maintain in the ventricle a separation of right and left atrial blood, by the sequential movement from the ventricle of first right and then left atrial blood, and by a sphincter‐action at the point of division of the truncus arteriosus which effectively shunts right atrial blood into the pulmocutaneous circuit. Left atrial blood in the frog is initially distributed selectively to the systemic arches; late in ventricular systole, some left atrial blood enters the pulmonary circuit. In the toad, both left‐to‐right and right‐to‐left mixing appear to occur, but only after significant periods of selective distribution.
Morphological and histochemical changes in the intrahepatic bile drainage system of the mouse following postnatal cholecystectomy
Authors: Yamada Kazuyori 
Published: February 2005

AbstractEffects of cholecystectomy at weaning upon the histological, histometrical and histochemical features of the intrahepatic bile drainage system were studied in young adult BUB mice of both sexes. The operation has, in 30 to 40 days, at least three different effects on various portions of the biliary system; (1) proliferative changes of interlobular bile ducts including very small ones, the cholangioles, (2) stimulation of activity of mucin secretion in the lining epithelium of large bile ducts and (3) increased alkaline phosphatase activity of bile canaliculi. In the light of known functions of the gall bladder, the proliferative changes of the interlobular bile ducts and the stimulated mucin secretion of the epithelium of large bile ducts are conceived to be developmental compensations for functions of the gall bladder. However, the increased bile canalicular phosphatase activity seems to indicate that such compensatory mechanism of the intrahepatic biliary system is only partially established at the time of observation.
The fine structure of elastic fibers in the fibrous periosteum of the rat femur
Authors: Taylor John J. , Yeager Vernon L. 
Published: February 2005

AbstractThe fine structure of the elastic fibers found in the fibrous periosteum of the albino rat femur has been described. Tissues were fixed in 3% glutaraldehyde and/or phosphate buffered osmic acid, embedded in Epon, stained with lead citrate and examined in an RCA EMU 3F microscope. The elastic fiber in the layer of fibrous periosteum is found to be composed of an array of longitudinally arranged elastofibrils embedded in a matrix of electron dense amorphous material. On cross section some of these elastofibrils appear to be tubular, presenting a dense cortex and a less dense central or core area. Reasons for these elastofibrils not being clearly and conclusively visualized in previous studies are discussed.
Development and distribution of elastic fibers in the mandibular joint of the mouse. A comparison of fetal, suckling, juvenile and adult stages
Authors: Frommer Jack , Monroe Clyde W. 
Published: February 2005

AbstractDevelopment and distribution of elastic fibers were studied in mandibular joints of white Swiss mice which ranged from 15 days insemination age to three months postnatal. Paraffin sections were stained with Weigert's resorcin‐fuchsin and Verhoeff's elastic tissue stain.Elastogenesis does not begin until the major elements of the mandibular joint are present. The first distinct elastic elements appear as granules at the nineteenth to twentieth day insemination age. Early sites of elastogenesis occur in the peripheral portions of the articular disk, at the transition and continuation of fibrous disk tissue with the periarticular tissues, and with the periosteum around the neck of the mandible.The concentration, length and caliber of fibers is increased markedly during the suckling stage, especially in the walls of the medial and lateral recesses of the synovial cavities, and in the posterior continuation of the disk to form a fibroelastic band of attachment to the squamosal bone. Prominent bands of long elastic fibers appear in the epimysium of the lateral pterygoid and masseter muscles in the young adult.The central portion of the disk and the articular surfaces of the mandibular condyle and fossa contain no elastic fibers, confirming the contention that these surfaces are not particularly stress‐bearing. Stretch and shearing stresses are created, however, which require extensive elastic fiber development in other joint tissues.