bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative observations of the hearts of mongrel and Greyhound dogs
Authors: Schneider Henry P. , Truex Raymond C. , Knowles Jack O. 
Published: February 2005

AbstractA study of 40 racing Greyhounds and 60 mongrel dogs provided comparative data on the respective components of the canine electrocardiogram. Additional data revealed that the Greyhound had a heart weight — body weight ratio of 1.25 gm, a heart rate of 115 beats per minute, a systolic blood pressure of 254 mm of Hg, and a diastolic pressure of 139 mm of Hg. These findings in an athletic animal are compared with similar observations in untrained animals. The significance of this basic information is presented and discussed.
Comparative histochemistry of the gastric mucosa: A survey of the common laboratory animals and man
Authors: Ragins Herzl , Dittbrenner Mary , Diaz Justo 
Published: February 2005

AbstractA comparative histological and histochemical study of the gastric mucosa was done with the frog, mouse, rat, hamster, guinea pig, rabbit, cat, dog and man. Enzymatic histochemical studies were done to demonstrate acid phosphatase (PbS and azo‐dye methods), thiamine pyrophosphatase (TPP‐ase) and NADH2 tetrazolium reductase activity. Cytoplasmic organelles were stained in some cases by three of the above methods i.e. acid phosphatase (PbS) activity marked the lysosomes, TPP‐ase activity marked the Golgi apparatus and NADH2 tetrazolium reductase activity marked the mitochondria. The acid phosphatase activity of the four major cell types was markedly different in the various species. The activity shown by both methods in individuals of a given species coincided well except in the rabbit and the dog. TPP‐ase activity demonstrated the Golgi region in the surface cells of all species except the guinea pig and the frog. The Golgi zones of zymogen cells showed strong activity only in the cat, while the parietal cell Golgi was not demonstrated in any of the species. NADH2 tetrazolium reductase activity in the parietal cells was strong in all animals except the mouse and the rat where staining was faint. The relationship between the lysosomes and the Golgi apparatus, as demonstrated histochemically in the gastric cells of the nine species, is discussed. The functional significance of these different enzymatic patterns has yet to be determined.
Placental and fetal development during multiple bovine pregnancy. Anatomical and physiological studies
Authors: Hafez E. S. E. , Rajakoski E. 
Published: February 2005

AbstractCattle were injected with PMS, bred and slaughtered 3, 30, 45, 60 and 90 days after ovulation and the genital tracts dissected. From 30 to 90 days of pregnancy the percentage increase in the weight of single embryos was 85 times as much as the increase in crown‐rump length. The volume of amniotic fluid increased 580 times in the second month of pregnancy and increased twice during the third month of pregnancy. The allantochorion did not lengthen between 60 and 90 days of pregnancy. At 30 days of pregnancy there was no significant difference in the crown‐rump length or the weight of embryos of singles, twins, triplets, quadruplets or quintuplets. The volume of placental fluid per embryo was higher in singles than in twins and triplets; the volume of placental fluids per embryo decreased further in quadruplets and quintuplets. The weight of the placental membranes per embryo was heavier in singles than in twins, triplets and quadruplets; the weight of membranes was markedly decreased in quintuplets. The effects of overcrowding in utero on the conceptus was more pronounced at 60 days than at 30 days and in quintuplets than in triplets and quadruplets. Anastomosis of vascular supply of allantochorions occurred as early as 30 days of pregnancy.
A rapid exposure of the facial nerve
Authors: Laurenson R. D. 
Published: February 2005

AbstractThis article describes a rapid exposure of the facial nerve by splitting the parotid gland along the faciovenous plane originally described by Patey and Ranger ('57).Scissors are thrust deep into the gland along the venous plane, and then opened to expose the facial nerve. This has been done in approximately 30 dissecting room subjects.
The epaxial muscles of the golden hamster
Authors: Salih Mohamad S. , Kent George C. 
Published: February 2005

AbstractThe epaxial musculature of the golden hamster based on 180 specimens has been described as follows. The Longissimus dorsi Group: L.d. pars cervicis, L.d. pars thoracis, L.d. pars lumborum, Extensor caudae lateralis. Muscles Primarily Cervical in Location: Splenius, Complexus, Biventer cervicis Semispinalis cervicis, Rectus capitis dorsalis major, Rectus capitis dorsalis minor, Rectus capitis lateralis, Obliquus capitis inferior, Obliquus capitis superior, Longus atlantis. Muscles Primarily Thoracic in Location: Spinalis dorsi, Iliocostalis. Short Deep Epaxial Bundles: Multifidus spinae, Extensor caudae medialis, Intertransversarii, Interspinales.
Fracture callus formation in young and old mice observed with polarized light microscopy
Authors: Tonna Edgar A. 
Published: February 2005

AbstractThe organized cartilaginous fibrous system which appears during growth of the fracture callus in traumatized femora was investigated in mice of five, 52 and 78 weeks of age. Histological preparations were stained with toluidine blue O and observed under polarized light using a first order red retardation plate.Development and organization of the cartilaginous fibrous system was similar in animals of all age groups studied, however, its time of appearance was dependent upon the time of appearance of cartilage cells and in association with these cells. Alignment of cartilage cells followed very closely after appearance of the fibrous system. Initial orientation of the fibrous system was almost perpendicular to the bone surface. As the system became more extensive the slope of fiber direction became less acute, pointing towards the fractured end of the shaft. Orientation of the fibrous system is believed to be a consequence of the forces set up during growth of the fracture callus, e. g., the force of the growing cell mass due to postfracture, active cell proliferation of the osteogenic layer of the periosteum and hypertrophy of cartilage cells and the tension placed on the fibrous layer of the periosteum in response to the events taking place below this tissue layer. The importance of the cartilaginous fibrous system is believed to lie in the early temporary support of the fracture fragments and the proper alignment of the cellular elements of the fracture, necessary for proper architectural reconstruction. Formation of the cartilaginous fibrous system was independent of the existing periosteal fibrous system.
Fine structure of the seminiferous tubule of the Swiss mouse. I. The limiting membrane, sertoli cell, spermatogonia, and spermatocytes
Authors: Gardner Paul J. , Holyoke Edward A. 
Published: February 2005

AbstractStudies of the ultrastructure of the seminiferous tubule of the Swiss mouse have shown the external limiting membrane to consist of internal and external lamellae enclosing a single layer of flattened cells. Both lamellae contain fibers, probably collagenous, running parallel to the long axis of the tubule. Superficially, a layer of connective tissue cells covers the external lamella. The nucleus of the Sertoli cell is typified by irregularity of size and shape, electron density of the nuclear membrane, and characteristic nucleolus. The cytoplasm contains mitochondria with vesicular cristae, and irregular dense bodies of possible secretory origin. Cytoplasmic processes extend between the germinal cells and in certain areas their surfaces are marked by periodic accumulations of fine granules which present a picture suggestive of desmosomes.Two types of spermatogonia have been noted. One possesses a large spherical nucleus containing finely granular nucleoplasm and scanty cytoplasm. The second is characterized by an ovoidal nucleus containing numerous chromatin clumps and scattered nucleolar fragments. Primary spermatocytes exhibit the intercellular bridges and synaptinemal complexes characteristic of these cells. The spherical nuclei contain densely packed fine granules. The nuclei of secondary spermatocytes often exhibit centrally located clumps of chromatin material. Mitochondria appear vacuolated at low magnifications but high magnification micrographs show them to contain finely membranous cristae.
Ciliated fibroblasts from a human brain tumor
Authors: Schuster Frederick L. 
Published: February 2005

AbstractRudimentary cilia were found on fibroblasts of a human brain tumor examined in the electron microscope. These cilia apparently have their origin in the centrioles of the fibroblasts; both centrioles appear to be involved in formation of cilia in most instances observed. Because of their atypical appearance and confinement by adjacent cell processes, it is unlikely that these cilia can perform any useful motor function for the cell. The cilia may serve as an expression of the morphogenetic potential of centrioles.
Lead acetate as a marker of growing calcified tissues a modified method
Authors: Scheiman‐Tagger Etty , Brodie Allan G. 
Published: February 2005

AbstractThe pattern of growth of bone and dentin was studied in serial decalcified sections by the use of lead markings. The experimental animals (monkeys and rabbits) received repeated intravenous injections of 4 mg lead acetate/kg body weight. The tissues were decalcified in 1% HCl through which H2S was constantly bubbled. Serial frozen sections were cut at 15–20 μ embedded in 10% gelatin and mounted in polyvinyl pyrollidone. They were placed in a 0.1% solution of gold chloride for ten minutes and then immersed for the same length of time in a 5% solution of sodium bisulphate in order to tone the background tissues. The sections were transferred to distilled water until the tissues became pink. When the desired toning was obtained they were fixed in 5% sodium thiosulphate. The examination of the sections obtained by this method confirmed the data obtained by other vital marking methods. However, much finer detail could be observed due to the sharpness of the lines and the use of relatively thin decalcified sections.
Development of the external ear in the dachs rabbit
Authors: Crary Dorcas D. 
Published: February 2005

AbstractDevelopment of that part of the external ear which protects the external auditory meatus appears to be similar in all animals since the hillocks of His have been described for reptiles, amphibia, and birds as well as mammals. Disagreement exists as to the origin and fate of the various hillocks, especially tragus and antitragus. Most observations of the developing ear have begun with the formation of the hillocks at which time the tragus is situated on the mandibular arch. Because of the rapid early growth, transitional steps from the open branchial groove to this stage have not been described previously. The retarded growth of the dachs rabbit makes it possible to see intermediate steps. Here it is shown that the entire auricle arises from an intact and continuous primordium, with the tragus arising from the hyoid arch and migrating to the mandibular bar in the normal course of cell proliferation and differentiation. Variations in normal and heterozygous animals can be found in the relative rates of development of the surrounding areas.
The effect of testosterone on the morphogenesis of the chick thymus
Authors: King John E. , Ackerman G. Adolph , Knouff Ralph A. 
Published: February 2005

AbstractBecause of the inhibitory effect of testosterone on lympho‐epithelial nodule formation in the bursa of Fabricius, possibly through the suppression of alkaline phosphatase activity of the surrounding mesenchyme, there appears the possibility of a comparable inhibitory effect on the thymus.1. A single dose of one tenth milliliter (2.5 mg) of testosterone propionate in sesame oil (Schering) was injected into chick eggs between the first and fifth days of incubation, i.e., before and during the time of differentiation of the thymus from the epithelial primordia and before the appearance of lymphoblasts. The thymuses of 195 chicks including 50 controls were examined after 18 days of incubation; grossly and microscopically the thymus gland was relatively unaffected in all but a few chicks.Because the thymus appeared unaffected by testosterone as opposed to its complete inhibitory effect on the bursa of Fabricius; and because of the apparent relationship of testosterone‐labile alkaline phosphatase to epithelial nodule formation in the bursa, further investigations were carried out on thymic differentiation and the possible role, if any, of alkaline phosphatase activity in the surrounding mesenchyme.2. Chick embryos between 5–10 days of incubation were fixed in 80% ethanol or absolute acetone, embedded in paraffin, serially sectioned and exposed to either Gomori's glycerophosphate or Burstone's naphthol AS‐MX phosphate procedures for alkaline phosphatase activity. The mesenchyme surrounding the developing thymus showed either a negative or a negligible reaction for alkaline phosphatase activity following these procedures. In contrast, the thymic primordium did exhibit slight phosphatase activity which appeared to be localized in the reticular‐epithelial cells.The difference in demonstrable alkaline phosphatase activity of the capsule of the thymus and of the subepithelial mesenchyme of the bursa of Fabricius suggests a fundamental difference in the differentiation of the two organs in the embryonic chick.
The fine structure of the thymocytes of young rats
Authors: Murray Raymond G. , Murray Assia , Pizzo Anthony 
Published: February 2005

AbstractThymocytes of young rats were studied with the electron microscope to provide a base line for a comparative study of the fine structure of various types of lymphocytes. Fixation with OsO4 or glutaraldehyde, Epon embedding, and heavy metal staining were the principal techniques employed. Small thymocytes, with nuclei from 3.5 to 4.5 μ in diameter are in the vast majority. Our results, which in general confirm previous reports, show the thymocytes to be primitive, or undifferentiated in structure. Certain exceptions and additions were noted, however. There are no protoplasmic bridges between thymocytes and epithelial cells and no clear evidence of epithelial‐thymocyte transformations. The nucleus contains typical pores and in many cases a clearly defined finely granular nucleolus, although the latter is not evident in most of the smallest cells. Cytoplasmic fragments appear to be separating from thymocytes by a process similar to the separation of platelets from megakaryocytes. The existence of a special band of cytoplasm beneath the plasma membrane devoid of formed elements is described for the thymocytes. The possibility of the common occurrence of this zone in other cells, and its possible significance, are discussed.
Ventricular blood pressures and competency of valves in the early embryonic chick heart
Authors: Paff George Hugo , Boucek Robert Joseph , Gutten Georgia Sharon 
Published: February 2005

AbstractBy direct ventricular puncture involving use of a micro‐pipette and water manometer the ventricular blood pressures of 81 chick embryos ranging in age from 2 to 7 days of age were obtained. The mean ventricular diastolic, systolic and mean blood pressures in millimeter of water (given in the order) were as follows: 5 ± 1.4; 21 ± 2.4 and 10 ± 1.4 in two day hearts, 10 ± 1.58; 27± 6.68 and 14 ± 14.32 in three day hearts; 14± 1.41; 39 ± 6.22 and 19± 2.39 in four day hearts; 17 ± 5.89; 63 ± 15.49 and 32 ± 12.08 in five day hearts; 5.45 ± 8.59; 74 ± 17.94 ± and 34 16.76 in six day hearts. At seven days the mean ventricular diastolic pressure was 1.33 ± 2.36 mm of water.Ventricular diastolic pressure increased from the second through the fifth days, underwent a marked drop at six days and fell to near zero at seven days of development. Since in fully developed hearts ventricular diastolic pressure approaches zero if the valves of the outflow tract are competent, the following conclusion concerning valvular action was drawn; the valvular mechanism of the outflow tract in the developing embryonic chick heart is incompetent at two, three, four and five days of development. It begins to become competent between the fifth and sixth days and attains competency at seven days.
Differential staining of bone tissue elements by silver nitrate staining of blocks of decalcified bone
Authors: Tappen N. C. 
Published: February 2005

AbstractBone can be differentially stained en bloc by fixing in 10% formalin, decalcifying in dilute nitric acid, and placing in an ammoniacal silver nitrate solution. The block is then infiltrated and embedded in gelatin for serial sectioning while frozen. Structures range from colorless to yellow, through different shades of brown or reddish brown, to black. This range is seen among different osteones, and even within a single osteone. Color changes within the same structure can be observed easily in serial sections. Collagen fibers, Sharpey's fibers, and assorted cell nuclei are also stained, but cement lines are not. Canaliculi usually do not stain, but occasionally stain vividly. Very darkly stained areas show little histological detail. Some of the characteristics of bone stained by this technique suggest that a relationship exists between the extent of mineralization and degree of staining. Similar features of x‐ray photomicrographs of undecalcified bone sections support such a relationship.
The fine structure of the rat umbilical cord at various times of gestation
Authors: Leeson Charles Roland , Leeson Thomas Sydney 
Published: February 2005

AbstractThe morphology of the umbilical cord of the rat has been investigated in fetuses of 17,19,20 and 21 days gestation. The development and differentiation of three major features of the cord, the covering amniotic epithelium, the mesenchyme of Wharton's jelly, and the major umbilical blood vessels, were studied. At 17 days gestation, the epithelium is composed of a simple layer of flattened cells without obvious specialization and later becomes bilayered and shows considerable irregularity at the surface and at cell‐interfaces, where desmosomes are a prominent feature in the stages just prior to birth. Within the underlying mesenchyme, there is a decrease in cellularity throughout the period under study. Mesenchymal cells are characterized by the presence of a well developed endoplasmic reticulum containing an electron dense homogeneous material. Ribosomes in association with the endoplasmic reticulum are in the form of polysomal aggregates by 17 and 19 days gestation which later become less marked. Unit fibrils of collagen increase in number in the days prior to term and in later stages appear in definite bundles. In the umbilical blood vessels, there is differentiation of a muscle coat from an aggregation of mesenchymal cells. No nerves in relation to the blood vessels and no vascular supply to the umbilical cord itself could be identified in any stage of the present study.
The Ureter, ureterovesical junction, and vesical trigone
Authors: Woodburne Russell T. 
Published: February 2005

AbstractThe musculature of the ureter has a layered arrangement in which the internal layer is mainly longitudinal and the external layer is largely circular. There is, however, intermingling and migration of fascicles between layers. At the passage of the ureter through the bladder wall this layering is lost and all fascicles become oriented longitudinally.At the ureterovesical junction fibers of the detrusor muscle of the bladder, interspersed with delicate connective tissue, reflect onto the ureter over a distance to 2 to 3 cm. This “sheath” of the ureter, as it has been designated, is a reflection of bladder wall muscle onto the ureter. At its passage through the bladder wall, the ureter is loose and an injectable space exists around it. This is properly termed “Waldeyer's separation” since he called attention to it in 1892.Within the bladder, the ureteric wall flattens and widens, allowing the lumen to migrate to the surface to constitute the ureteral aperture at the angle of the vesical trigone. Delicate muscular decussations occur proximal and distal to the aperture.Ureteric muscle mainly forms the vesical trigone. Most fascicles run to the midline and blend with those of the opposite side in the interureteric fold. Others spread through the trigone, its lateral margin being formed of somewhat more numerous fascicles directed toward the vesical orifice. Very few fibers actually descend into the urethra. The principal fixation of the ureter into the bladder is to the mucous membrane of the trigone area and to the deeper lying muscle and connective tissue.
Sequence of action of the diaphragm and quadratus lumborium during quiet breathing
Authors: Boyd W. , Blincoe H. , Hayner J. C. 
Published: February 2005

AbstractA series of 15 rabbits had multiple intercostal clip electrodes implanted in the diaphragm and quadratus lumborum at open operation.Leads from the electrodes were passed to the back of the animals and soldered to a junction band. Simultaneous recordings of electromyographic activity and spirometry were made following recovery.The study revealed that the quadratus lumborum, acting simultaneously with the diaphragm, is an effective inspiratory muscle stabilizing the twelfth rib, converting it into a fixed point from which the diaphragm act. Very possibly the action of the quadratus pulls down the lower rib helping to increase the costo‐diaphragmatic recess. Like the sternal, crural and costal portions of the diaphragm, the quadratus exerts a braking action to oppose the normal elastic recoil of the lungs during expiration.
Further studies on the development of the lateral motor column in anuran larvae. I. Normal development in Rana temporaria
Authors: Race James , Terry Robert J. 
Published: February 2005

AbstractA study was made of the normal development of the lateral motor column (LMC) in the lumbo‐sacral region of the European grass frog, Rana temporaia. The results were then compared with the development of the LMC in Rana pipiens (Beaudoin, '55), in order to determine if the difference in life cycle between the two species would result in differences in development of the column. The results show that the overall developmental pattern in R. temporaria is no different from that found in other anura. There is a general decrease in the large number of cells present early in the larval period and a concomitant increase in the size of the remaining cells during development through metamorphosis. During metamorphosis, at least 80% of the original population of cells are lost. Immediately following forelimb emergence, nuclear area is at least 52% larger than the nuclear area of cells found at the earliest stage. In both species, the largest decrease in cell number and increase in cell size is at the time the circulating thyroid hormone concentration is at its highest level. Although the pattern of development in the two species is similar, the number and size of the LMC cells differ significantly between the two species during the late larval stages. This difference can be attributed to the difference in life cycle between R. pipiens and R. temporaria.