bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uniformity of structural characteristics throughout the length of skeletal muscle fibers
Authors: Farrell Patricia R. , Fedde M. R. 
Published: February 2005

AbstractFresh‐frozen, serial cross–sections of the transversus abdominis muscle of four mature chickens (98 fibers) were examined to determine structural and histochemical characteristics throughout the entire length of skeletal muscle fibers. Fiber diameter and nicotinamide adenine dinucleotide diaphorase (NAD‐D) and myosin adenosine triphosphatase (ATPase) activities were used as criteria to classify fibers as Type I or II. Measurements were made at 10 to 22 locations along the length of the fibers. An unimodal distribution of mean fiber diameters ranging from 48 μ to 86 μ was found. Fibers did not appear larger in the belly of the muscle than near the ends. Although small fluctuations in fiber diameter occurred through the length of a fiber, large and small fibers tended to remain relatively large or small at each location. NAD‐D activity was either consistently high or low throughout the length of a fiber. Likewise, myosin ATPase activity was either high or low for an entire fiber. It is concluded that skeletal muscle fibers maintain rather uniform structural and histochemical characteristics along their entire length.
Lysosomes in uterine involution: Distribution of acid hydrolases in luminal epithelium
Authors: Anton E. , Brandes D. , Barnard S. 
Published: February 2005

AbstractThe distribution of acid hydrolytic activities in rat uterine epithelial cells during post‐partum involution was examined by light and electron microscopic cytochemistry. Acid phosphatase, β‐glucuronidase, N‐acetyl‐β‐glucosaminidase and E600‐resistant esterase (cathepsin) increased during the period of involution and the electron cytochemical preparations revealed the lysosomal nature of the acid hydrolytic positive particles visualized by light microscopy.The newly formed particles included primary lysosomes, in the form of Golgi vesicles, vacuoles, and secondary lysosomes such as dense bodies and autophagic vacuoles. This apparent increase in lysosomal activity during uterine involution is in agreement with similar patterns observed in the course of tissue regression in general.
The role of the thymus in development of lympho‐hemopoietic tissues. The effect of thymectomy on development of blood cells, bone‐marrow, spleen, and lymph nodes
Authors: Kalpaktsoglou Pitsa K. , Yunis E. J. , Good R. A. 
Published: February 2005

AbstractThe effect of thymectomy at different ages in C3H mice on development of circulating leukocytes and cells of marrow, spleen and lymph nodes has been analyzed. Regardless of the age at which thymectomy is performed depression of numbers of circulating lymphocytes is produced. Thymectomy at birth did not affect significantly the relative number of lymphocytes in the marrow during the first few weeks of life, later they fell to low levels. Thymectomy at four weeks was followed by prompt reduction in relative numbers of lymphocytes in the marrow.After reaching six weeks of age, neonatally thymectomized mice showed a high proportion of monocytes in the marrow. Neonatal thymectomy and thymectomy at two weeks of age reduced the number of eosinophils in the marrow.Neonatal thymectomy inhibited development of lymphocytes in the spleen, whereas thymectomy later in life produced only transient depression of lymphocytes in this organ. In addition, neontal thymectomy decreased the relative numbers of small lymphocytes in the lymph nodes. This was associated with drastic depletion of lymphocytes in the deep cortical regions of the nodes.
The phrenic nerve: Its terminal divisions and supply to the crura of the diaphragm
Authors: Thornton Myra Williams , Schweisthal Michael R. 
Published: February 2005

AbstractA study of the crura of the diaphragm and their innervation from the phrenic nerve was made in 22 fresh specimens and four embalmed specimens. The arrangement of the musculature was found to be essentially the same as that described by Low in 1907. The portions of the crural musculature passing to the right and left of the esophagus did not decussate anterior to the esophagus as these fibers insert into the central tendon. The right and left phrenic nerves divided into three to five divisions at the pericardiodiaphragmatic angle. Most commonly, these divisions are: anterior, posterior and lateral. If there are more than three divisions involved, there is usually a medial division present and/or a subdivision of one of the other divisions. It is the posterior division or its posteromedial branch which contributes to the innervation of the crura. None of the other divisions contributes to the innervation of the crura. Secondary branches of either the posterior division or the posteromedial branch do not cross to the contralateral side.
The effects of fluoride and low calcium on the physical properties of the rat femur
Authors: Beary Dexter F. 
Published: February 2005

AbstractThe effect of fluoride on the physical properties of bone was investigated with the aid of an Instron materials tester. Two groups of weanling female rats, one on an adequate (0.6%) calcium diet and the other on a low (0.1%) diet were given the following dosage levels of fluoride (as NaF) in their deionized drinking water over a fifteen and one‐half week period: 3.4 ppm, 10.0 ppm and 45.0 ppm. In the adequate calcium group a significant increase in flexibility in the rat femur was found only at the 45.0 ppm dosage level. This was not offset by a significant decrease in strength. In the low calcium group a similar significant increase in flexibility appeared at the 10.0 ppm dosage level as well as the 45.0 ppm, but a significant decrease in strength at the two dosage levels was observed. These were in direct relation to the amount of fluoride given.
Hair growth cycles in subcutaneous implants
Authors: Chase H. B. , Sanford Barbara H. , Arsenault Claudette T. , Carroll Sarah B. 
Published: February 2005

AbstractSkin fragments implanted subcutaneously into syngeneic mice remained viable and showed cyclic hair growth over a period of months. Embryonic skin differentiated into the various layers of epidermis and corium, producing sebaceous glands and hair follicles. Implants from both embryos and newborn displayed normal hair pigmentation with appearance in metanagen of the yellow bands characteristic of the agouti hair for that genotype. Follicles were observed to pass through the various hair growth stages into a resting period and then later to re‐enter the growth cycle. There were departures from normal hair growth, however, with some follicular disorganization, especially in the newborn implants, and with areas showing mixed growth stages instead of the follicular synchronization characteristic of the intact mouse.
Stratified squamous metaplasia of the uterine epithelium in early androgen‐treated rats and its inhibition by light deprivation
Authors: Reiter Russel J. 
Published: February 2005

AbstractRats, having been given a single subcutaneous injection of testosterone propionate at four days of age, exhibited polyfollicular ovaries, extensive stratified squamous uterine metaplasia and persistent vaginal cornification (90–95% of the smears contained cornified cells) after adulthood was attained. If early androgentreated rats were blinded at 22 days of age the number of vesicular follicles in the ovaries of adults was greatly diminished, the incidence and extent of stratified squamous metaplastic lesions were suppressed and the number of vaginal smears containing cornified cells was reduced by about 50%. The effects of blinding, however, were negated by pinealectomy illustrating that the suppressive influence of light deprivation on reproduction was mediated by way of the pineal gland.
Nuclear and cytoplasmic annulate lamellae in trophoblast giant cells of rat placenta
Authors: Jollie William P. 
Published: February 2005

AbstractSingle stranded profiles of nuclear annulate lamellae were identified in giant cells of rat trophoblast from the day when the chorioallantoic placenta first becomes vascularized, viz., day 12 post coitum, until the day before term, viz., day 22. Cytoplasmic annulate lamellae were observed only in giant cells from placentas at day 12. Occasionally cytoplasmic annulate lamellae were found in parallel array. Often the lamellar membranes were continuous with both granular and agranular membranes of endoplasmic reticulum; they closely resembled doubled outer nuclear membrane. Nuclear annulate lamellae resembled doubled inner nuclear membrane; and often the two were found in continuity. In addition, at later gestational ages (17 and 22 days), nuclear lamellae often were related anatomically to the variety of nuclear inclusions which characterize giant trophoblast cells during late pregnancy. A possible relationship of annulate lamellae to the synthesis of DNA, RNA and protein is considered.
Structural luteolysis of induced corpora lutea in “androgen‐sterilized” rats
Authors: Malven P. V. , Francis R. P. 
Published: February 2005

AbstractFive‐day‐old female rats were made anovulatory by injection of 50 μg testosterone propionate. When the animals were at least 120 days old, corpora lutea (CL) were induced by injection of human chorionic gonadotrophin (HCG). Various treatments were initiated 15 days after HCG and the morphological regression of induced CL was examined 30 days after HCG. Structural luteolysis was very slight in control animals, suggesting that prolactin secretion was minimal. Exogenous prolactin hastened the rate of luteal regression. Daily injections of estradiol or reserpine also caused rapid structural luteolysis. Destruction of the arcuate nucleus of the hypothalamus also induced morphological regression at a more rapid rate than in controls. In conclusion, exogenous prolactin or three different treatments known to promote secretion of endogenous prolactin accelerated the rate of luteal regression in induced CL.
Origin of amphibian premelanosomes and their relation to microtubules
Authors: Wise Gary E. 
Published: February 2005

AbstractIn amphibian melanophores, premelanosomes appear to be formed in fenestrated cisternae of the Golgi complex. The premelanosomes may develop within the cisternae or vesicles containing melanoprotein may bud from the cisternae to form premelanosomes. Some micrographs also demonstrate a close association between microtubules and either premelanosomes or melanosomes. The microtubules themselves may originate from electron dense particles in the centrosphere region of the cell.
Osmium binding to the surface coat of intestinal microvilli in the cat under various conditions
Authors: Pratt S. A. , Napolitano L. 
Published: February 2005

AbstractThe appearance of the carbohydrate‐rich surface coat covering the the intestinal epithelium of the cat varies with different methods of fixation for electron microscopy. A fibrillar surface coat covers the external surfaces of the microvilli after fixation in glutaraldehyde and postfixation in phosphate‐buffered OsO4; its density is enhanced by heavy metal staining. In tissue fixed in glutaraldehyde alone or followed by dehydration in acetone and postfixation in OsO4 in carbon tetrachloride, a structureless zone less dense than Epon occurs where the surface coat is usually visualized; heavy metal staining does not impart density to the zone. The absence of structure and low density of the zone are not due to extraction of the surface coat by dehydrating agents or by carbon tetrachloride. The data suggest that osmium binds to the surface coat from phosphate buffer, but not from carbon tetrachloride. Also OsO4 in phosphate buffer, but not OsO4 in carbon tetrachloride, facilitates heavy metal staining of the surface coat. Acidic carbohydrates appear to be important for the differential binding of osmium observed in this study. The need for caution in interpreting low density areas of electron micrographs as extracted structures and high density areas as “osmiophilic” structures is discussed.
Age changes in the cranial base of the rabbit (Oryctolagus cuniculus)
Authors: Moore W. J. , Spence T. F. 
Published: February 2005

AbstractThe growth changes in the cranial base of the rabbit between one and 20 weeks after birth have been investigated. The basicranial axis and its anterior extension completed some 50% of their growth during this period in contrast to the posterior extension which had completed 70% before one week. The sphenoethmoidal angle underwent no statistically significant changes despite a decrease in the spheno‐maxillary angle indicating that the face became disposed below rather than directly anterior to the braincase. The foramino‐basal angle decreased progressively during the period of investigation.The pattern of growth in the linear dimensions of the rabbit cranial base is essentially similar to that already established in man and subhuman primates. The angular changes, however, differ from those in primates where the spheno‐ethmoidal and foramino‐basal angles follow more closely the developmental patterns of the braincase and facial skeleton.
The structure of the interalveolar septum of the mammalian lung
Authors: Ryan Stephen F. , Dumais Charles , Ciannella Arnold 
Published: February 2005

AbstractLight and electron microscopic examination of serial transverse sections of interalveolar septa of hamster lung have demonstrated a virtually continuous connective tissue sheet of variable thickness in the interalveolar septum. This central sheet, like connective tissue elsewhere, is composed of ground substance in which are immersed cells, collagen and elastin. A capillary network lies on each surface of this sheet. The capillary basement membrane is continuous with the central sheet but in contrast to it is thin, uniform and devoid of cells, collagen or elastin. Capillaries on one surface frequently anastomose directly through the septum with capillaries on the opposite surface.The central sheet is shown to be virtually continuous despite frequent thinning. Whenever cells, collagen or elastin occur in the interalveolar septum, it is always in the central sheet. The efficiency of this arrangement in combining optimum gas conductance with adequate mechanical support is pointed out.The central sheet is also continuous with the perivascular connective tissue cuff and thus may serve as an important route of extracellular fluid transport to the perivascular lymphatics.
The fine structure of the vasa recta and associated nerves in the rabbit kidney
Authors: Gosling John A. , Dixon John S. 
Published: February 2005

AbstractThe fine structure of the vasa recta and associated nerves has been studied in the rabbit. Vasa recta were first identified in groups of two or three and were accompanied by small groups of axons. A number of these axons contained granulated, agranular and dense‐cored vesicles. As the vasa recta subdivided, the muscle coat consisted of a single layer of smooth muscle cells. Additional large axon bundles were observed accompanying this segment of the vasa recta. Some of these axons also contained granulated, agranular and dense‐cored vesicles in varying proportions. Further towards the medulla, smooth muscle cells were replaced by others which had irregular collections of filaments within their cytoplasm. These in turn were replaced by cells having a characteristic band of filaments on their luminal aspects. Nerves were only identified adjacent to those parts of the vasa recta which included smooth muscle cells.
Tissue fluid movement in compact bone
Authors: Seliger William G. 
Published: February 2005

AbstractThorotrast (colloidal thorium dioxide) was released into tibial marrow cavities of 12 adult cats and into the tibial nutrient arteries of ten adult cats. Following regular intervals the tibiae were removed, fixed, decalcified in formic acid, and prepared histologically.The label indicated the general tissue fluid drainage of the tibia is in the perivascular connective tissue of Volkmann's canals from the marrow cavity to the periosteal lymphatic vessels.The tissue fluid flow appears to pass from the Haversian vessel through the canalicular‐lacunar complex to the peripheral lacunae of the osteone. Its path from this point has not been observed.
Morphology and histochemistry of the oviduct and egg‐jelly layers in the frog, Rana pipiens
Authors: Shivers C. Alex , James Judith M. 
Published: February 2005

AbstractMorphologically the oviduct of the frog, Rana pipiens, consists of a lining epithelium and tubular jelly‐secreting glands. The oviduct can be divided into six regions (designated R1 anteriorly—R6 posteriorly) based on the differential staining of the jelly glands. The regions measured 1, 5, 6, 3, 20 and 3 cm, respectively. These regions correspond to 6 histochemically distinct layers of jelly (designated J1 nearest the egg through J6 farthest from the egg) which are deposited around the egg during the egg's sojourn in the oviduct. A correlation between lengths of each oviducal region and thickness of individual jelly layers was observed. That is, J5 is the thickest, followed by J3, 2, 6, 4 and J1 which is thinnest.Histochemical properties of jelly glands and corresponding jelly layers were essentially the same in the tests performed. All regions and layers except R5 and J5 contain a large amount of acid mucopolysaccharide and the mucopolysaccharide in R and J1, 3 and 4 is sulfated. Neutral mucopolysaccharide is present in R2, J2, R5 and J5. Although protein is present in all layers and oviducal regions it was found in higher concentration in R and J1, 3 and 6 and in lowest concentration in R and J2.
Cytomorphometric and biochemical differences between the muscle cells in atria and ventricles of the guinea pig heart
Authors: Plattner H. , Tiefenbrunner F. , Pfaller W. 
Published: February 2005

AbstractDifferences in succinate dehydrogenase and cytochrome oxidase activity and also in the Q for a medium containing pyruvate, glutamate, fumarate and glucose (equimolar) were found using histochemical and manometrical methods, when muscle cells of the atria and the ventricles in the guinea pig heart were compared. Most of the activity values were higher in the ventricles than in the atria. According to cytomorphometric measurements, these differences can be explained by differences in the mitochondrial volume (per unit volume of cytoplasm) rather than by a different ultrastructural organization of the individual mitochondria, since they show the same stereological organization in both the atria and the ventricles. The reduced mitochondrial volume in the atria results in a lower density of “oxidative” (i.e., inner mitochondrial) membranes per unit volume of cytoplasm.
Autonomic innervation in rabbit salivary glands
Authors: Freitag Per , Engel Milton B. 
Published: February 2005

AbstractAutonomic innervation of rabbit salivary glands was demonstrated by modifications of the methods of Falck for catecholamines and Koelle for the localization of cholinesterase activity. To avoid and diminish artifacts, tissues were rapidly frozen, cut in a cryostat, and freeze‐dried under vacuum. Catecholamine fluorescence and cholinesterase activity were found in the serous parotid and the mainly mucous submandibular gland, strongly indicating that both glands are innervated by sympathetic and parasympathetic fibers. In the parotid gland, the sympathetic ground plexus apparently forms a denser network than that seen in the submandibular gland. Catecholamine fluorescence, indicating sympathetic nerves, is found to be closely related to most acini, blood vessels of both glands, and some ducts of the submandibular gland. Cholinesterase activity, signaling the presence of parasympathetic fibers, was observed around many acini, ducts, and some blood vessels of both glands. A theory is presented that the autonomic innervation of salivary glands influences the state of intracellular colloids, water, and electrolytes during secretion.
Age criteria for the prenatal and immature mongoose in Hawaii
Authors: Tomich P. Quentin , Devick William S. 
Published: February 2005

AbstractAnatomical age markers are established in the small Indian mongoose (Herpestes auropunctatus) for embyronic, fetal, nestling and juvenile stages. Embryos and fetuses excised from living pregnant females and placed on a time scale of 49 days, the known gestation period, indicate that implantation is at approximately eight to ten days after insemination and that the transition from embryo to fetus occurs at about 14 to 28 days. The sequence of stages grossly discernible in prenatal development is highly similar to that in other mammals. Age in laboratory‐reared pups was correlated with a regular sequence of tooth eruption and replacement. The full set of permanent teeth is present at the age of 22 weeks. M3 was found in 2.8% of 142 adult skulls examined. Prominent reductions occur in the slope of the growth curve during early fetal stages, and at birth, weaning and independence from the mother.
The distribution of acetylcholinesterase and catecholamine containing nerves in the rat lung
Authors: El‐bermani Al‐Walid , McNary William F. , Bradley Donna E. 
Published: February 2005

AbstractThe distribution of catecholamine and acetylcholinesterase containing nerve fibers in the rat lung was studied employing specific histochemical techniques. Silver impregnation and methylene blue staining was used to allow comparison with the results of previous workers. Catecholamine containing nerve fibers were found associated with the nerve plexus about bronchial arteries and were carried to the bronchial wall and the pulmonary vessel wall along branches of the artery. Acetylcholinesterase containing fibers followed along the bronchi and bronchioles and were found in the adventitia, mucosa and submucosa, Acetylcholinesterase containing nerves were not found in the perivascular plexi with the exception of a few positive nerve fibers within the larger pulmonary veins.
Morphologic changes in white and brown adipose tissue by insulin, thyroxin and cortisol in organ culture
Authors: Slavin Bernard G. , Elias Joel J. 
Published: February 2005

AbstractIn order to compare the morphologic response of white and brown fat to various hormones in vitro the technique of organ culture was used in this study. Explants of white and brown fat from young mice fasted for 48 hours were exposed to culture media supplemented with insulin, thyroxin or cortisol. Morphologic changes due to these hormones were studied by means of histologic analyses and cell width measurements. Insulin acted to increase the size of cells and intracellular lipid content of brown and white fat explants when compared to similar explants exposed to unsupplemented media. Brown fat explants reacted earlier than white fat in this case. Thyroxin or cortisol alone had no influence on cell width or intracellular lipid content of these tissues. With the combination of insulin and thyroxin only white fat cells showed a greater increase in lipid deposition than that seen with insulin alone. No significant changes were noted when the combination of insulin and cortisol, or when all three hormones were added to the culture medium compared to that seen with insulin alone. The conclusion reached confirms those of other authors that brown and white fat possess enough dissimilarities to be classified as two different types of tissue.