bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of satellite cells in altering myosin expression during avian skeletal muscle hypertrophy
Authors: McCormick K. M. , Schultz E. 
Published: February 2005

AbstractThis study examined whether satellite cells express an embryonic isoform of myosin upon fusion with hypertrophying muscle fibers. Anterior latissimus dorsi (ALD) muscle hypertrophy was induced in adult chickens by weighting one wing. One and 7 days of wing‐weighting produced significant increases in ALD muscle wet weight and in the number of mature fibers expressing ventricular‐like embryonic (V‐EMB) myosin. V‐EMB myosin expression could be an event during regeneration of fibers injured by overload or part of the hypertrophy process itself. Although there was an increase in both the number of damaged fibers and the number of mature fibers expressing embryonic myosin after wing‐weighting, results from this study suggest that these two events were not necessarily related. The apparent health of fibers expressing V‐EMB myosin and the lack of correlation between the numbers of damaged and V‐EMB myosin positive fibers (r = 0.20) suggest that embryonic myosin expression in mature fibers was likely a feature of the hypertrophy process itself. The appearance of V‐EMB myosin in mature fibers 1 day after wing‐weighting suggests that the change in myosin expression did not involve satellite cells since 24 hr is too short a time to permit more than limited satellite cell fusion. The relationship between satellite cells and embryonic myosin expression was examined more closely by labeling dividing satellite cells and their progeny with 5‐bromo‐2‐deoxyuridine, and then colocalizing labeled myofiber nuclei and embryonic myosin in consecutive transverse sections of hypertrophied ALD muscle. One week of wing‐weighting resulted in marked increases in myofiber nuclear labeling index and myofiber nuclear density compared to contralateral control. V‐EMB myosin was not expressed uniformly throughout individual fibers, but rather in discrete regions of varying length. Many V‐EMB myosin positive regions had a higher labeled nuclear density than V‐EMB myosin negative regions indicating that V‐EMB myosin expression was associated with an accumulation of satellite cell progeny in a restricted area. However, it was also clear that satellite cell progeny were not the sole source of V‐EMB myosin since labeled nuclei were completely absent from 41% of the V‐EMB positive regions. Futhermore, the presence of new nuclei did not result in obligatory expression of embryonic myosin because many V‐EMB negative regions had a high labeled nuclear density. Thus, recently incorporated nuclei arising by satellite cell division are implicated as one, but not the sole source of embryonic myosin in hypertrophying muscle. These observations suggest that the non‐uniform pattern of embryonic myosin expression in hypertrophying muscle resulted from differences in nuclear activity, not necessarily the addition of new nuclei. © 1994 Wiley‐Liss, Inc.
Forward spreading in the establishment of a vertebrate Hox expression boundary: The expression domain separates into anterior and posterior zones, and the spread occurs across implanted glass barriers
Authors: Gaunt Stephen J. , Strachan Lorna 
Published: February 2005

AbstractBy use of wholemount in situ hybridization, we show how expression of the chicken homeobox gene Hoxd‐4 commences in the posterior part of the primitive streak and then spreads forward, covering most of the primitive streak by the 2 somite stage, covering the entire primitive streak by the 5 somite stage, reaching the somite 1/somite 2 level of the neural tube by the 9 somite stage, and reaching the rhombomere 6/rhombomere 7 junction of the hindbrain by the 15 somite stage. Forward spreading does not depend upon cell migration, as was evidenced by vital dye (DiI) cell marking experiments. Furthermore, forward spreading does not apparently require tissue continuity since it could not be blocked by impermeable (glass) barriers surgically implanted to divide embryonic tissues. As forward spreading of chick Hoxd‐4 proceeds, the domain of expression separates, at late primitive streak stages, into “anterior” and “posterior zones,” with an intervening “intermediate zone” of weak or non‐expression. Clear anterior and posterior zones were also found for Hoxa‐3 and a‐4 expression in late primitive steak stage mouse embryos. We present evidence that the anterior zone corresponds with the “definitive” domain of Hox gene expression, as has earlier been extensively characterized in midgestation embryos. The posterior zone is transitory, probably persisting only for the duration of the primitive streak, and it is a region of intense Hox expression in primitive streak tissue, Hensen's node, and adjacent regions of neurectoderm and mesoderm. We suggest that the posterior zone marks the source of a morphogen which is the primary activator of Hox gene expression, and we discuss possible models for the mechanism of forward spreading in expression. © 1994 Wiley‐Liss, Inc.
The effect of D‐L ethionine on the pancreas of normal and pregnant hamsters
Authors: House E. L. , Jacobs M. S. , Pansky B. 
Published: February 2005

AbstractA series of 49 normal male and female adult hamsters, nearly equally divided as to sex and 37 pregnant animals received ethionine subcutaneously or intraperitoneally. Normal animals were given 1.0, 0.7 or 0.4 mg per gram of weight per day over a period of 4 to 14 days. Pregnant animals received either 1.0 or 0.7 mg, beginning at different intervals during gestation: from the third to sixth; on the eighth, of from the tenth to twelfth days, the course ranging from two and one‐half to 15 days. Normal females were more sensitive than males. Among the latter, the 1.0 mg dose produced degeneration of exocrine tissue in ten days with no deaths, while in normal females, 0.7 mg gave similar results with little mortality or liver pathology. In pregnant females, the drug had adverse effects, vaginal bleeding and high mortality resulting when administered on the eighth day or later. From 11 survivors, only two litters were obtained, no damage being found in either maternal or neonatal pancreases. Pregnant animals started on the third to sixth day with the 0.7 mg dose tolerated it well. However, all but one of 17 expected litters died long before birth. The pancreases from the new‐born were normal with only slight damage found in the maternal pancreas. The route of administration was of no consequence.
Dynamic condition of proteins in the visual cells of rats and mice as shown by radioautography with labeled amino acids
Authors: Droz B. 
Published: February 2005

AbstractThe behavior of proteins in retinal rods was examined by injecting various labeled amino acids (methionine‐S35 and ‐H3, tyrosine‐, leucine‐, and arginine‐H3) into rats and mice, which were sacrificed at different time intervals between 10 minutes and 30 days. The retina of these animals was then radioautographed.Within minutes after injection of any one of the listed amino acids, a radioautographic reaction appears over the inner segment of the rods. This region of the cell is therefore a site of protein synthesis. Since this synthesis may be seen at any time of the day, it must be a continuous phenomenon.At 24 hours after injection, the radioautographic reaction appears over the junction of the inner and outer segments, and at 1.5–4 days, over the outer segment. Hence, the recently synthesized protein progressively migrates from the inner, toward and into the outer segment.Analysis of the decay of the specific activity in the inner segment reveals that two categories of proteins are synthesized there. One is a slowly turning over protein, presumably catabolized in situ and referred to as “sedentary.” The other is a fast turning over protein, which migrates into the outer segment and is referred to as “exportable”. The exportable protein may be opsin.
Chemocytological studies on a sudanophile substance in parathyroid cells of the toad (Bufo vulgaris japonicus)
Authors: Hara Jun , Yamada Kazuyori 
Published: February 2005

AbstractA sudanophile lipid was demonstrated in the parenchymal cells of the toad (Bufo vulgaris japonicus) parathyroid gland in specimens taken at the end of hibernation. A series of histochemical staining methods and extraction techniques for lipids were applied to the parathyroid tissues in an attempt to characterize chemocytologically the sudanophile substance. From its chemocytological properties such as sudanophilia and nile blue sulfate and acid hematein stainability, the substance was concluded to consist primarily of glycerides and phosphatides. The cytophysiological significance of these lipid moieties in the parathyroid cells was discussed in relation to the hibernation of the amphibian species.
Effects of radiocobalt irradiation of pregnant rabbits on the development of fetuses
Authors: Chang M. C. , Hunt Dorothy M. , Harvey Elmer B. 
Published: February 2005

AbstractFemale rabbits were irradiated from a radiocobalt source on various days of pregnancy and examined three to five days before delivery. Following irradiation at 400 r, on days two, four or six before implantation, 24% of the embryos implanted and 19.9% developed into apparently normal fetuses; on day seven or eight at the time of implantation or soon after, all embryos died although 61% implanted; on days 9, 10 or 11, 16.5% of the embryos developed into living fetuses with high incidences of short tail and cleft palate and with low incidences of abnormal forelimbs, fused digits of forelimbs and exencephalia; on days 12, 13 or 14, 35% of the embryos developed into fetuses with a high incidence of fused digits in the fore‐ or hind‐limbs; on days 15 to 22, 30% of the embryos developed into living fetuses without gross abnormalities.Irradiation at 250 r on day eight did not cause death of all embryos as it did at 400 r. With irradiation at 250 r on days 8 to 14, 51 to 60% of the embryos developed into living fetuses with low incidences of abnormalities.The size of fetuses was reduced very little following irradiation on days two to six or on days 18 to 22. But the size is distinctly reduced following the irradiation on days 11 to 16.Necrosis of tissue, pycnosis of nuclei, and vacuolation of cells in the embryos were observed six hours after the irradiation of mothers at 400 r on days seven and eight.
Electron microscopy of the acinar cell of the that preputial gland
Authors: Beaver David L. 
Published: February 2005

AbstractThe rat preputial gland is a morphologically complex structure active in both lipid and protein secretion. By electron microscopy, its acinar cells contain an extensively developed endoplasmic reticulum and numerous Golgi vacuoles, where the protein secretory granules apparently arise. As the granules mature, they assume a crystalloid configuration and, after losing their surrounding membranes when the cell degenerates, are deposited in an excretory duct along with lipid and cellular debris. The granules are apparently unrelated either to mitochondria or to tonofiliments, but seem to represent a true protein secretion of the acinar cell itself.
Studies of cartilage and osteoid arising spontaneously and experimental attempts to induce their formation in ear chambers
Authors: Williams Roy G. 
Published: February 2005

AbstractClark and Clark using a rabbit's ear chamber in which the observation space was in direct continuity with perichondrium reported cartilage arising spontaneously in more than 40% of chambers. With a chamber of different design having a very restricted relationship to perichondrium, osteoid, that is, an unmineralized bone‐like tissue, appeared in 5 of 110 animals and in two of the five there were also unrelated islands of cartilage. In one additional animal osteoid developed three months after local application of continuous pressure of minute degree. In the remaining 104 animals no cartilage or osteoid formed irrespective of the experimental usage to which the chambers were put. The results are interpreted to mean that in rabbit's ear chambers cartilage or osteoid may form from precartilaginous cells resident in or derived from perichondrium but not by metaplasia of morphologically similar connective tissue cells. If a special stimulus was necessary to activiate the precartilaginous cells then the only obvious ones were friction and pressure both of very small degree but continuously maintained for long periods.
Plastic mounting of microscopic serial sections
Authors: White Lowell E. , Moberg Gertrude 
Published: February 2005

AbstractA technique is described for mounting both small and large serial sections on Dupontleader film or pieces of Mylar‐D plastic sheeting. The blocks are processed in the usual fashion and embedded in paraffin or celloidin. Small sections are mounted serially on five‐foot strips of 35 mm film in a gelatine waterbath and allowed to dry. The film strip is placed on a Nikor developing reel, the paraffin dissolved, the tissue hydrated, and the staining carried out in the usual fashion. The sections are cleared and allowed to dry and then covered with Varathane which hardens in 24 hours. The film strips are stored on 35 mm spools. Large paraffin embedded sections are processed separately in a similar fashion, mounted on Mylar‐D sheets, and stored in a loose‐leaf notebook. When celloidin is used it must be removed before mounting. The sections can be studied microscopically by passing the film over the stage of a microscope in a sequential fashion. The advantages of the method are discussed.
A histochemical study of the toad urinary bladder
Authors: Keller Albert R. 
Published: February 2005

AbstractHistochemical methods for the demonstration of enzyme activities and carbohydrates were applied to the bladder of the toad, Bufo marinus. The three cell types in the mucosa (ordinary epithelial cell, goblet cell, and mitochondria‐rich cell) were found to be distinctive with the methods used. Dehydrogenase enzyme activities were highly concentrated in the mitochondria‐rich cells. Membrane‐associated ATPase activity was found in the basal cell‐membranes of the mucosal cells, where active sodium transport is thought to occur. The potentialities of the various cell types for active electrolyte transport are discussed.
Extrinsic nerves of the chicken's uterus (shell gland)
Authors: Freedman S. L. , Sturkie P. D. 
Published: February 2005

AbstractEighty‐six White Leghorn chickens were examined in a study of the neural components of the hen's uterus (shell gland). All nerves supplying the uterus were found to originate from only the left side of the body.Contributions from the sympathetic nervous system were supplied by the hypogastric nerve, which is the direct continuation of the aortic plexus, coursing along the hypogastric artery to the uterus. The parasympathetic pelvic nerves originate from the pelvic visceral rami of spinal nerves 30 — 33. The several ganglia and numerous nerves situated along the left pelvic nerve compose the left pelvic plexus. Nerves emanating from the left pelvic plexus course along the middle uterine and posterior uterine arteries to their termination on the uterus. The ganglia situated on the right pelvic nerve are not considered to constitute a right pelvic plexus, as they make no direct contribution to the reproductive system.
Studies on the innervation of the stapedius muscle of the cat
Authors: Blevins Charles E. 
Published: February 2005

AbstractA study of nerve‐muscle relations and fine innervation patterns is reported for the stapedius muscle of the cat. Gross relations of the muscle to its associated nerves and other middle ear structures are shown by illustrations. Histologic features of innervation are studied with the Bodian silver method. the thiocholine technique, and iron hematoxylin and osmic acid stains.The muscle is richly supplied by 3 to 4 facial nerve branches in which no axons are found above 8 μ and the majority are unimodally grouped at 2–4 μ. The auricular nerve of the vagus does not penetrate the muscle. Three to four distinct zone is of fasciculi are found whose muscle fibers are 14–20 μ in diameter. Each zone is supplied by primary nerves whose branches do not exhibit terminal overlap or multiple innervation of muscle fibers. Short terminal axons lead to motor and plates from all intramuscular nerve branches. Nerve branches and motor end plates are confined to the basal third of the muscle. Sensory endings are not detected within the muscle or its tendon. It is estimated that each motor neuron supplies no more than five muscle fibers but more probably three or less.
The diameters of the cerebral arteries of the human fetus
Authors: Seydel H. Gunter 
Published: February 2005

AbstractNinety‐eight fetal specimens of the circulus arteriosus cerebri and adjacent arteries were injected with a mixture of latex and barium sulphate and dissected after fixation in formalin. Measurements of the intracranial part of the internal carotid artery were carried out and the measured diameters were compared to those of the other arteries at the base of the fetal brain. The diameters of the internal carotid artery were symmetrical and increased approximately linearly with fetal size from 0.7 mm for a fetus of 15.5 cm crown rump length to 2 mm in a specimen with 37.2 cm crown rump length. In one specimen, the intracranial part of the right internal carotid artery was smaller than the left. This was associated with an anomaly of the arterial circle. Twenty‐one circles were symmetrical and complete. The most significant differences between adult and fetal diameters were in the posterior part of the circle, the circular part of the posterior cerebral artery showing a relatively smaller average diameter (0.34 of the diameter of the internal carotid artery) than that described for adult specimens (0.47) while the posterior communicating arteries were of similar diameter (approximately 0.27) in both adults and fetuses. In three cases one posterior communicating artery was absent. No berry aneurysms were found upon inspection with a hand lens.
Studies on the fate of lymphocytes II. Intravenous injection of labeled thymic lymphocytes into homologous rats and isologous mice
Authors: Murray Raymond G. , Murray Assia 
Published: February 2005

AbstractSuspensions of thymic lymphocytes, 60–80% of which had been labeled in vivo with H3‐thymidine, were injected intravenously into 54 homologous rats and 22 isologous mice. Radioautographs2 of blood and of tissues were analyzed. The cells rapidly disappeared from the blood, although less rapidly in the isologous than in the homologous systems. A large fraction was still present in the tissues during the first post‐injection day. In the first hour many were arrested in the lung, some of which were later redistributed to other organs. At later intervals the spleen contained the greatest concentration, followed by lymph nodes and bone marrow. Cells were found occasionally in the duodenal mucosa, in mice only, and in no case did they reach the thymus. A few survived in both rats and mice for as long as seven days.Only one labeled cell was seen in mitosis. There was evidence of transformation to erythroblasts in the liver, spleen and bone marrow; to myelocytes in the bone marrow; and to macrophages in the spleen. Label from some of the cells dying in the liver apparently was reutilized by the Kupffer cells.
Analysis of the influence of thyroid hormone on prenatal and postnatal maturation of the rat
Authors: Hamburgh Max , Lynn Edward , Weiss Earl P. 
Published: February 2005

AbstractThe effects of hyper‐ and hypothyroidism on fetal development and on the postnatal maturation of the central nervous system was studied in the rat. Our observations indicated that the development of the rat fetus, as measured by birthweight and skeletal maturation of the newborn animal is not markedly influenced by presence or absence of thyroid hormone during the prenatal stage.Availability of thyroid hormone is a more critical factor with respect to maturation of the nervous system taking place in the postnatal animal.Delay in cerebellar maturation and delay in increase in dry weight of cerebrum and cerebellum were noted in hypothyroid rats. A transitory acceleration of oxygen consumption of these structures during their maturation was also noted in hyperthyroid litters.A more permanent suppression of learning behavior and of the thermoregulating mechanism was observed in young hypothyroid rats deprived of thyroid hormone since birth.It is concluded that requirements for thyroid hormone during development of the rat are limited to a critical period coinciding with the first two to three weeks of postnatal age.
Calculation of cranial capacity from linear dimensions
Authors: Dekaban Anatole , Lieberman J. E. 
Published: February 2005

AbstractPhysical anthropological and x‐ray linear measurements of length, breadth and height of 28 dried skulls were made. The means and variances of these measurements were calculated and are given in tables. Next, the cranial capacity of these skulls was measured with mustard seeds (this method was validated using water measured skull) and the means and variances are given separately for males and females. Two formulae: (1) Lee's ‐ Males, 0.365 (L × B × H) + 359.34; Females, 0.375 (L × B × H) + 296.40. (2) Spheroid‐π/6 (L × B × H) were applied to calculate cranial capacity (in milliliters) from the linear anthropological and radiological dimensions (in centimeters). The results of the volumes thus obtained were compared to each other and to the control volume of the respective skulls. It was concluded that both the Lee's and Spheroid formulas for calculating the volume showed acceptably small difference from the respective control values. However, the Lee's method gave closer to control volumes for anthropological measurements whereas the Spheroid method gave closer to control volumes for x‐ray measurements.
The renewal areas of the common bile duct epithelium in the rat
Authors: Cohen P. J. 
Published: February 2005

AbstractThe common bile duct epithelium has been studied in common bile duct‐ligated and sham‐operated rats treated with colchicine, and numerous colchicinemitoses have been observed largely localized in the biliary or tubular “glands.” This finding suggests that the “glands” serve as the centers of cell division, i.e., the “renewal areas,” within the duct epithelium. Evidence has also been found that the duct epithelial cells are shed from the surface (luminal) epithelium into the lumen.In these cytological features, the common bile duct epithelium resembles the small intestinal epithelium, and this suggests the possibility that the pattern of cell renewal and replacement in the common bile duct epithelium is similar to that in the small intestinal epithelium, i.e., the “gland” cells constantly divide and replace the cells which are lost from the surface epithelium.