bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prevention and reversal of glycogen infiltration in the pancreatic islets of fetuses from diabetic rats
Authors: Kim Jae Nam 
Published: February 2005

AbstractFetuses removed by Caesarean section (between days 17 and 21 of pregnancy) were compared with litter‐mates removed at autopsy (between days 21 and 23).In one diabetic group, all rats were treated with a large dose of insulin until Caesarean section when insulin treatment was stopped. No fetuses removed by Caesarean section showed glycogen infiltration when blood sugar was less than 240 mg/100 ml. At autopsy, glycogen appeared in all fetuses from mothers which had blood sugar levels above 240 mg/100 ml for two days or longer; no glycogen appeared in fetuses from mothers which had blood sugar levels below 240 mg/100 ml.In another diabetic group, all rats were treated with insulin, but the insulin dose was increased immediately after Caesarean section. All fetuses removed by Caesarean section showed glycogen infiltration when the blood sugar level was greater than 240 mg/100 ml. At autopsy, glycogen had disappeared in fetuses from mothers which had blood sugar levels less than 240 mg/100 ml for 2 to 3 days; glycogen persisted in fetuses from mothers which had blood sugar levels above 240 mg/100 ml.It is concluded that glycogen appears in fetal islets if blood sugar level is greater than 240 mg/100 ml for two days or longer. This change is both preventable and reversible and is influenced by the level of blood sugar and by the duration of hyperglycemia.
External morphology of the erect glans penis of the dog
Authors: Hart Benjamin L. , Kitchell Ralph L. 
Published: February 2005

AbstractThe external morphology of the erect glans penis was studied and compared to that of the nonerect organ. Morphological changes that occur with tumescence and detumescence were also reported. Some distinct parts of the erect pars longa glandis which are not distinguished in classical nomenclature are described and labeled. These structures are the urethral process, corona glandis and collum glandis. These distinct morphological areas coincide with areas which seem to be functionally distinct in both the erect and nonerect glans penis. The implications that these observations may have for considerations of comparative anatomy of the external male genitalia are discussed.
Bilateral asymmetry in weight and in length of human bones
Authors: Latimer Homer B. , Lowrance E. W. 
Published: February 2005

AbstractThe weights and lengths of right and left bones of each pair, from 105 human skeletons from Asia, were studied.All of the long bones of the upper are heavier and longer on the right side. The left femur is heavier and longer. The right tibia and fibula are heavier while the left tibia and right fibula are longer. The right scapula is heavier and the os coxae, clavicle and the bones of the hand and foot are heavier on the left side.Generally, the left bones are more variable in weight and length. The upper extremity and its individual bones manifest more asymmetry than the lower.The proximal bone of upper and lower extremities and the scapula and os coxae show a greater degree of asymmetry in weight than the the more distal bones.In general, the left bones have slightly higher correlations with total skeletal weight. These and the intercorrelations between right and left bones of the six pairs of long bones of the extremities are all significant and positive. The highest intercorrelations of the long bones are between right and left bones of a pair.
The weight and thickness of the two ventricular walls in the newborn dog heart
Authors: Latimer Homer B. 
Published: February 2005

AbstractThe weight and thickness of the two ventricular walls of the heart were measured in 80 newborn puppies. These puppies were born in the dog colonny, the descendants of a typical heterogeneous collection of dogs, for student use in the laboratory.The hearts of these dogs average 2.07 gm in weight. The left ventricular wall is slightly heavier and also slightly more variable in weight than the right wall. The two free ventricular walls comprise 56% of the weight of the entire heart. The ratio of the weight of the left to the right ventricular wall, at birth, averages 1.0078.The left wall is also slightly thicker than the right wall. The thickness of the right wall is more variable than the left. The ratio of the thickness of the left to the right ventricular wall is 1.036.These data are compared with other available measurements on adult dog hearts and on human hearts.
A comparison of selected morphological and chemical methods for measuring neuron activity in the supraoptic nucleus of dehydrated rats
Authors: Ifft John D. , Berkowitz Wallace 
Published: February 2005

AbstractA comparison of results of measuring supraoptic neuron activity was made in normal and in dehydrated rats by the following methods; (1) Measuring the nucleolar diameter of the neurons with a filar micrometer, with an image splitting eyepiece and, with the latter instrument, using the “comparative technique”—all three methods yielded statistically significant differences. (2) Measuring the concentration of cresyl violet in the nucleoli with a microspectrophotometer—a statistically significant difference was found. Also included for comparison were the results of a previous experiment in which the ribonucleic acid and succinic dehydrogenase content of the supraoptic nucleus was measured with a spectrophotometer following chemical extraction. The RNA was found to increase significantly but not the succinic dehydrogenase. Of the methods used for measuring nucleolar diameters the “comparative technique” appeared to be the most rapid from the practical viewpoint.
Dorsal roots of the rabbit investigated by freeze‐substitution
Authors: Malhotra S. K. , Van Harreveld A. 
Published: February 2005

AbstractDorsal roots from adult rabbits prepared by a freeze‐substitution technique and studied by electron microscopy have been compared with those obtained by standard fixation with OsO4. The essential features of myelinated and nonmyelinated fibers and their associated Schwann cells are similar in appearance after both types of fixation. There are, however, slight differences. The extracellular clefts between the nonmyelinated axons and their associated Schwann cells are wider in freeze‐substituted roots (200 to 250 Å versus 100 to 150 Å). The major dense lines in the myelin sheath are wider (45 to 55 Å versus about 30 Å) and their radial repeat period is larger (145 to 155 Å versus 100 to 120 Å) in freeze—substituted material than in routinely fixed nerves.
Fertilization and early development of dorset horn sheep in the spring and summer
Authors: Chang M. C. , Rowson L. E. A. 
Published: February 2005

AbstractThe estrous cycles of 34 Dorset Horn ewes were observed during the spring and summer in East Anglia. The majority of sheep (22 out of 34) came in heat fairly regularly. In 26 out of 37 estrous cycles the duration was between 14 and 25 days. Laparotomy performed soon after estrus did not prolong the subsequent estrous cycle in the majority of animals. Failure of ovulation following estrus was not observed; the observations were made either at laparotomy or at autopsy. The rate of ovulation was 1.55 per cycle as assessed by counting the number of corporalutea in the ovary. The time of ovulation was estimated at about 30 to 40 hours after the onset of estrus.Following deposition of semen into the Fallopian tubes of nine ewes, either before or soon after ovulation, five eggs were recovered but none of these was found to be fertilized. Following intra‐cervical insemination or mating 21 fertilized eggs, at different stages of division, were found in 11 out of 29 ewes. In 13 ewes out of 26 which were examined 5–17 days after mating 15 normal embryos were found. Photomicrographs of early sheep embryos are presented and the low fertility of sheep in summer is discussed.
Differentially localized incorporation of amino acids in relation to epidermal keratinization in the newborn rat
Authors: Fukuyama Kimie , Nakamura Toshio , Bernstein I. A. 
Published: February 2005

AbstractIncorporation of tritiated methionine, phenylalanine, leucine, glycine and histidine into protein in the epidermis of the newborn rat was studied by autoradiography.Methionine, phenylalanine and leucine behaved similarly. Thirty minutes after injection, radioactivity was detected in both nucleus and cytoplasm of the basal, spinous and granular cells with a greater intensity over the cells of the lower layer as compared with that observed over the upper layer. The label appeared over the cornified cells at 24 hours after injection probably as a result of the migration of cells into the cornified layer. In the case of glycine and histidine, the label was detected in eachof the three layers at 30 minutes after injection but the labeling was higher in the upper part of the epidermis as compared with the lower part. The label appeared in the cornified layer six hours after injection. Processes possibly involved in formation of the cornified layer are discussed.
Rapid pinealectomy in hamsters and other small rodents
Authors: Hoffman Roger A. , Reiter Russel J. 
Published: February 2005

AbstractRemoval of the pineal organ from small rodents may be rapidly accomplished by (1) immobilizing the skull in a head mounting device and (2) by cutting and removing a circular disc of bone overlying the pineal area with the use of a dental machine and a specially designed circle cutter.
The sinus node artery in man
Authors: Ryback R. , Mizeres N. J. 
Published: February 2005

AbstractThirteen sinus node arteries from human material (2 months post partum to 68 years) were studied by various histologic techniques for connective tissue, muscle, and nerve distribution and arrangement. Its relationship to the sinus node is also emphasized. The outer longitudinal muscle coat of the artery is replaced with a thick adventitia. This loss of smooth muscle is not typically found in other coronary arteries. In addition, many nerve fibers, arranged both circularly and longitudinally, present the possibility of a pressoreceptor mechanism related not only to coronary blood pressure changes but also to the neurogenic control of the heart beat.
Propagation and prolongation of mitotic activity in the formation of injury‐induced lentomas in Rana pipiens
Authors: Rafferty Nancy S. 
Published: February 2005

AbstractAutoradiography following labeling with H‐3‐thymidine was used to study the pattern of growth of injury‐induced lentomas in Rana pipiens. This reaction to injury was compared with the more controlled reaction in the rabbit lens, which has been extensively studied by others.These studies show that, unlike that of the rabbit, the entire lens epithelium of the frog reacts within a day to the injury stimulus by disarrangement of its normal architecture. H‐3‐thymidine is incorporated between 24 and 40 hours post‐injury, followed subsequently by widespread mitotic activity. Peak thymidine incorporation occurs at three days and peak mitosis at five days post‐injury. However, the stimulus to mitotic activity is propagated after the first week largely among the superficial cells of the enlarging lentoma and adjacent normal epithelium; DNA synthesis and mitosis in the deeper cells of the lentoma diminish at a week and cease by two weeks post‐injury, and by three weeks in the superficial cells.It is concluded that the frog lentoma is formed by accretion from the surface as a result of extensive multiplication of cells throughout the injured epithelium. The reaction of frog and rabbit lenses to injury differs both in the extensiveness of the initial reaction and the duration of the stimulus to proliferation.
Normally occurring intraluminal projections in the arterial system of the mouse
Authors: Menschik Zygmunt , Dovi S. Frank 
Published: February 2005

AbstractThe arterial system of 27 ICR/Albino mice was studied by: (1) examining 8 μ thick serial histological sections, (2) observing under the dissecting microscope the interior of arterial segments split longitudinally, (3) making reconstruction models, 100 times magnified from serial sections and (4) applying various histological and histochemical stains to determine morphological details. Almost regularly at each point of origin of an arterial branch, a structure forming a specific anatomical entity was observed and referred to as an intraluminal projection. A typical projection consists: (1) of an elevation or cushion located at the proximal edge of the orifice, (2) of two collateral ridges running distally at the sides of the orifice and becoming gradually thinner and taller, and (3) of a union of collateral ridges into a semilunar, flap‐like, movable structure guarding the distal edge of the orifice. Imperfectly developed intraluminal projections were occasionally encountered at the origin of large arteries from the abdominal aorta. Histologically a projection is entirely luminal to the internal elastic membrane, has an endothelial covering of thickened endothelial cells and consists of a stroma containing polygonal elongated cells which have oval nuclei and resemble smooth muscle fibers. They are surrounded by a network of elastic and reticular fibers. The intraluminal projections may regulate the volume and pressure of blood entering the branch by sphincteric and valvular mechanisms.
The evolution of the mm. interossei in the primate hand
Authors: Lewis O. J. 
Published: February 2005

AbstractVarious conflicting views relating to the phylogenetic history of the interossei are reviewed. The primitive mammalian (marsupial) precursors of these muscles are shown to present a bilaminar arrangement: a dorsal layer of four bipennate abductor muscles (inserting into a proximal phalanx) is overlaid ventrally by a sheet of ten flexores breves, grouped in pairs, and inserting as wing tendons into either side of the extensor aponeurosis of the corresponding digit. The homologues of these muscles are identified in the hands of representative Primates including Homo. The dorsal abductors become the dorsal interossei proper; the flexores breves become the palmar interossei, which are therefore frequently more numerous than the four found in man. Certain of the flexores breves show a tendency to merge with those subjacent abductors with which they insert. Thus, the descriptive human dorsal interossei are composite muscles resulting from the amalgamation of a flexor brevis with a dorsal interosseous proper. Comparative morphology is shown to provide a logical basis for the understanding of the extensor apparatus of the human fingers.
The effect of bleeding and starvation on blood volumes and peripheral hemogram of the turtle, Pseudemys scripta elegans
Authors: Hirschfeld William J. , Gordon Albert S. 
Published: February 2005

AbstractIn assessment of some aspects of the erythropoietic system of a poikilothermic vertebrate, values were determined for red cell, white cell, reticulocyte and circulating erythroblast numbers as well as hematocrit, hemoglobin, the erythrocyte corpuscular constants and serum iron concentration in normal and in starved turtles. Starvation caused no change in the peripheral hemogram but resulted in a decrease in serum iron.Bleeding of normal turtles decreased both the red cell and plasma volumes, while starvation resulted in only a slight lowering of the plasma volume. In addition, blednormal turtles showed decreases in hematocrit, hemoglobin concentration and serum iron concentration.In the cellular response to bleeding, radioiron‐labeled erythroblasts appeared in the circulation by the second day after Fe59 administration. A sudden rise occurred on the fourth day which was associated with a high spleen radioactivity. Erythroblast levels were elevated in the blood of bled‐normal but not in bled‐starved turtles. Indeed, the bled‐starved animals appeared incapable of increased erythropoiesis as measured by any of the criteria used in these studies.
Cell number deficiencies in the nervous system of dwarf mice
Authors: Viola‐Magni Mariapia 
Published: February 2005

AbstractA quantitative histologic investigation has been performed on the nervous system and striated muscle of the dwarf mouse (Snell's Strain).The number of nerve cells in the spinal cord of the dwarf mouse is half of that seen in the normal mouse. These data are fully confirmed by separate counts of efferent and afferent fibers of the spinal roots. Spinal root fiber diameters are similar in both normal and dwarf mice. The number of muscle fibers in the peroneus longus muscle is about the same in both the normal and in the dwarf mouse; the diameter of each muscle fiber, however, is reduced in the dwarf.At the muscular level the deficiency manifests itself as a volumetric reduction in the muscle fibers; whereas, at the level of the spinal cord there is a reduced number of nerve cells. It follows from these observations that in the dwarf mouse the ratio of nerve fibers to muscle fibers within a motor unit is altered so that each motor neuron innervates more muscle fibers than in the normal mouse. This fact could explain the peculiar movements of the dwarf mouse.
Effect on the weights of fetuses and fetal lymphoid organs of adrenalin given to rabbits at a critical period of pregnancy: Observations on spontaneous and induced runting
Authors: Wier Katherine 
Published: February 2005

AbstractThe effect of injecting adrenalin at a critical period in pregnant rabbits was investigated. This critical period is around the twenty‐second day of pregnancy, when the maternal blood supply to the uterus is naturally low. The relative weights of thymus, spleen and appendix and the total body weights of the fetuses were measured both one week after the injection and eight weeks after birth to examine long range effects. Controls consisted of saline‐injected and untreated rabbits.The adrenalin injection reduced significantly the fetal weight compared with that of the controls. The relative thymus weight was found to be significantly correlated positively with fetal weight in both adrenalin‐treated animals and controls. However, there was no significant difference in relative thymus weight between the two groups.Of the two litters raised to eight weeks, the young of the untreated litter showed a fairly constant growth rate. The pups of the adrenalin‐treated litter started out smaller than the controls but at about three and one‐half weeks the former overtook the controls; at eight weeks they were, on the average, larger. With this small sample size, the difference in weights cannot be shown to be statistically significant, but the litters show consistent differences.
Mammillary complex of cat brain—aspects of quantitative organization
Authors: Fry William J. 
Published: February 2005

AbstractAccurate determination of the neuron populations of the medial and lateral mammillary nuclei in normal cat brains, and of the same structures (after quasi‐equilibrium of the cellular populations is achieved) in brains of these experimental animals modified by unambiguous lesion arrays, provides the foundation for deciphering features of the neuronal circuitry that cannot be elucidated on the basis of qualitative neuroanatomic knowledge. This paper is concerned first with the closeness of agreement of cell population values between bilaterally corresponding mammillary nuclei in the same brain and with the degree of reproducibility of the ratio of the populations of the lateral and medial nuclei of this complex from one brain to another. Second, it is concerned with illustrating in specific cases the usefulness of population ratios determined from normal and from modified brains in revealing important neuroanatomic relations: (1) clarifying the structure of the dorsal bifurcation of the principal mammillary tract into the mammillothalamic and mammillotegmental tracts for fibers projecting from the medial mammillary nucleus, and (2) deciphering the neuronal circuitry of the bilateral projection of each lateral mammillary nucleus to the anterior dorsal nuclei of the thalamus.
The hair follicle group in mice
Authors: Claxton J. H. 
Published: February 2005

AbstractInitiation and development of the follicle population in mice were examined during embryonic and early postnatal life. The shape of the curve relating follicle density with age suggests that follicle intiation begins in the 14‐day‐old embryo and continues until about two days after birth. During the period of follicle intiation, groups of follicles are established in a regular and systematic way but at any particular age during this period, the stage of development of adjacent groups is not always synchronous so that when initiation ceases the composition and numerical size of different groups are highly variable. Although 75% of all groups contained three, four, or five follicles some were composed of only two and others as many as 11 folllices. In adult mice the most notable feature of the spatial distribution of follicles is often only the tendency for follicles to be arranged in rows. An examination of the follicle population about six days after birth showed that this feature is not incompatible with the earlier developmental grouping structure. A comparison of the proportions of different fiber types in the coat with the proportions of follicles occupying specific positions in the follicle groups was unable to establish any close relationship between follicle and fiber types. Evidently the type of fiber grown by a follicle is more dependent on the age when the follicle is initiated than on the position of the follicle in the follicle group.
The attenuation of elastic tissue in the aorta of the baboon, Papio doguera
Authors: Katzberg Allan A. 
Published: February 2005

AbstractA histological study was made of the quantitative distribution of elastic elements in the aorta of the baboon, Papio doguera. Materials were obtained in East Africa from freshly sacrificed animals as well as from domestic stock, and represented all age groups from a fetus near term to 28 years. Verhoeff's elastic tissue stained sections were prepared from 4 zones from the arch to the bifurcation.All specimens showed an attenuation of the thickness of the aortic wall as well as a decrease in the number of layers of elastic membranes from the arch to the bifurcation. The attenuation was less prominent in the older and heavier animals. The reduction in the number of elastic membranes at the lower end indicates a reduced requirement for the storage of ventricular energy by the elastic constituents for blood propulsion. Gravitational forces may be instrumental in maintaining blood flow to the lower extremities without additional expenditure of energy of ventricular origin.
Differences in internal structure and nerve terminals of the slow and twitch muscle fibers in the cat superior oblique
Authors: Pilar Guillermo , Hess Arthur 
Published: February 2005

AbstractMeasurements of nerve fiber size in the trochlear nerve indicate that many small nerve fibers are present which could serve as the small nerve motor supply for innervation of the slow muscle fibers in the superior oblique of the cat. Twitch and slow muscle fibers in the superior oblique muscle of the cat have been examined in the electron microscope. In twitch fibers, triads consisting of the transverse tubule and dilated sacs of the sarcoplasmic reticulum occur at the level of junction of A and I bands. In the slow fibers, the sarcoplasmic reticulum is reduced in amount and the transverse tubular system is completely absent. The junctional folds of the postsynaptic membrane of the muscle fiber under the nerve terminal of a twitch fiber are present, although not extensive; in slow fibers, these postjunctional sarcolemmal folds are essentially absent. Some physiological implications of these differences in fine structure of twitch and slow fibers and their respective nerve terminals are discussed.