bluuebunny/crossref_metadata_2025_split huggingface dataset:
The ultrastructure of neonatal calf intestine and absorption of heterologous proteins
Authors: Staley Theodore E. , Corley Lane D. , Bush Linville J. , Wynn Jones E. 
Published: February 2005

AbstractThe ultrastructural morphology of the jejunal and ileal cells of newborn calves was similar to the intestinal absorptive cells of other newborn ungulates. Microvilli were well developed, tubules or invaginations in the apical cytoplasm were extensive. Large supranuclear vacuoles were limited to the ileal cells. After injection of ferritin‐IgG or ferritin into ligated intestinal loops, the ferritin particles were found around the microvilli and within the tubular system. After 2‐6 hours ileal vacuoles containing ferritin were found near the basal membrane. In the jejunal cell ferritin was found only in the tubules. No ferritin could be detected in calf sera after injection into the intestinal loops. To establish that heterologous proteins were absorbed, calves were given human serum via stomach tube and their sera subsequently was found to contain circulating levels of human albumin and gamma globulin. Also newborn pigs and suckling rats also were given ferritin; but it could not be detected in their sera. The results of these experiments suggest that while the neonatal intestine is permeable to some het‐erologous proteins, ferritin is not transported across the absorptive cell into the circulation.
The relationship of ultrastructural and cytochemical features to absorptive activity in the goldfish intestine
Authors: Gauthier Geraldine F. , Landis Story C. 
Published: February 2005

AbstractIn the adult goldfish, Carassius auratus (a stomachless freshwater teleost), there is a striking proximal‐to‐distal gradient in the microscopic appearance of the intestine. This gradient is correlated, moreover, with differences in the site of absorption of lipid and protein. The proximal regions (intestinal bulb and anterior intestine) have a greater surface area, manifested by elongated mucosal ridges in which the epithelial cells have regularly arranged closely spaced microvilli. The distal region (posterior intestine) has less overall surface area, but the epithelium exhibits the typical ultrastructural features of pinocytosis, namely extensive invagination of the luminal surface membrane and massive accumulation of vesicles and vacuoles in the apical cytoplasm. In addition, a conspicuous PAS‐positive supranuclear “body” is visible with the light microscope. Administered triglyceride is absorbed exclusively by the epithelium of the anterior regions, where presumably, it must be hydrolyzed prior to uptake. Protein (horseradish peroxidase), on the other hand, is absorbed primarily in the most distal region, where the epithelium appears to be equipped for the uptake of large intact molecules. These regional differences are discussed in relation to comparable differences in the mammalian intestine, especially during development.
The action of extrinsic penile muscles during copulation in the male dog
Authors: Hart Benjamin L. 
Published: February 2005

AbstractElectromyographic activity of the bulbocavernosus (BC), ischiocavernosus (IC), and ischiourethral (IU) muscles was recorded during copulation in male dogs to examine the role of these muscles in the vascular engorgement process as related to the mechanisms responsible for initiating and maintaining the genital lock. In other dogs the IU muscle was severed to ascertain the influence this would have on the genital lock. No particular function in the engorgement process could be assigned to the IC muscle. Recordings from the BC muscle are consistent with the suggestion that rhythmic contraction of this muscle plays a role in pumping blood from the proximal parts of the corpus spongiosum into more distal parts of this cavernous erectile body. This would facilitate rapid engorgement of the bulbus glandis which is the structure that locks the dogs together. Recordings from the IU muscle reveal that this muscle contracts tonically just after intromission apparently also facilitating erection of the bulb by occluding venous return. Section of this muscle prevented engorgement of the bulb and eliminated the genital lock.
The development of the folia in the human cerebellar vermis
Authors: Loeser John D. , Lemire Ronald J. , Alvord Ellsworth C. 
Published: February 2005

AbstractThe development of the folial patterns of the human cerebellar vermis has been studied in 44 mid sagittal sections of fetuses (14 weeks gestational age to term), infants (one to three months) and adults. The differentiation of each of the lobules of the vermis has been plotted as a function of age. The gestational age at which each lobule has attained half the adult average number of folia has been determined and varies between 24 and 37 weeks; the more anterior and posterior vermian lobules reach this half‐way point first even though the largest lobules (culmen, declive and pyramis) form more folia per unit time. Thus, different criteria may be used to evaluate growth rates and yield different conclusions concerning the validity of the concept that ontogeny recapitulates phylogeny. The adult numbers of folia are not attained until more than two months after birth. The normative data reported in this study provide a baseline for comparison with other species or with abnormal developmental patterns in autopsy specimens of any fetal or post‐natal age.
Distribution of muscle spindles in the human first dorsal interosseus
Authors: Sahinen Frederic M. , Kennedy William R. 
Published: February 2005

AbstractThe problem of accurately locating muscle spindles within the bulk of skeletal muscle has been the major difficulty in histological evaluation of human muscle spindles and in attempts to record their physiological activity. Entire first Dorsal Interossei were taken from full‐term infants, stained in toto by deCastro's silver technique, serially sectioned or squashed, and individual spindles microdissected for study. A model of the muscle with its extrafusal innervation was constructed and the average number of spindles in five muscles was found to be 47 (range 4C–54). The first Dorsal Interosseus muscle is a bi‐pinnate structure divided by a central tendon which inserts on the proximal first phalanx. The spindles within this muscle are nearly equally distributed between the halves. Most of the spindles are concentrated in two well‐defined regions, a lateral, more distal spindle‐rich region and a medial, more proximal, grouping. Each of these two concentrations consists of approximately one‐third of the spindles present, the remaining one‐third being rather uniformly distributed throughout the muscle mass. An idea of the degree of concentration usually seen is illustrated by finding as many as eight spindles present in a 100X field in cross‐section. This density of concentration and apparent consistency of location within the muscle is expected to facilitate procurement of more adequate numbers of spindles at muscle biopsy and to aid the intramuscular recording from human muscle spindles.
The effects of high altitude on the reproductive cycle and pregnancy in the hamster
Authors: Printz Richard H. 
Published: February 2005

AbstractMature female golden hamsters, which had demonstrated regular reproductive cycles, when exposed to 23,000 feet simulated altitude for eight or more days became acyclic. Their ovaries, which were polyfollicular, suggested that LH release or synthesis by the hypophysis had been blocked. Human chori‐onic gonadotrophin (which has LH activity) caused similarly exposed animals to ovulate. When animals which were exposed to high altitude for nine days were returned to control altitude, they ovulated five days later. Starvation for nine days, which has no significant effect on adrenal weight but does cause increased LH dependent ovarian interstitial development at control altitude, failed to do so at 23,000 feet. It is hypothesized that high altitude selectively blocks LH secretions by the hypophysis.High altitude also interrupted pregnancy when treatment lasted four or more days and was begun before day 12. Since follicular development of pregnancy continued normally but corpora lutea regressed and both FSH and prolactin are needed to maintain the hamster corpus luteum, this study suggests the possibility that prolactin secretion is blocked in the pregnant animal at high altitude.
Possible division of cardiac mitochondria
Authors: Tandler Bernard , Hoppel Charles L. 
Published: February 2005

AbstractNumerous examples of partitioned mitochondria were present in cardiac muscle cells of mice, rats, guinea pigs, and canaries. The partitions, which usually bisected the mitochondria, consisted of two parallel membranes in direct continuity with the inner mitochondrial membrane. Some of these mitochondria showed varying degrees of constriction at the level of the partitions. In many partitioned organelles, the two sets of cristae on opposite sides of the septum were positioned at right angles to one another, so that if one set was seen in profile, the other appeared en face. This arrangement of cristae simplified the detection of partitioned mitochondria even at low magnifications.The number of mitochondria and the frequency of occurrence of partitioned mitochondria were considerably enhanced in heart muscle cells of some weanling mice by feeding them the copper‐chelating agent, cuprizone. The mitochondria, both with and without partitions, were identical to those in untreated animals. Based on this and other experimental evidence, and by analogy with other organs, notably mammalian liver and insect fat body, it was concluded that partitioned cardiac mitochondria are in fact dividing.
An in vitro and in vivo study of single palatal processes
Authors: Smilay Gary R. , Koah William E. 
Published: February 2005

AbstractSingle palatal processes were grown in organ culture to test whether epithelial contact was a prerequisite for the cytological alterations observed during midline epithelial disruption. Observations were made with the light and electron microscopes. Palatal processes from 14 day C57BL mice were cultured on Millipore filters and fixed in paraformaldehyde and osmium tetroxide. Fine structure studies of 24 hour cultures revealed a thick basal lamina beneath an intact epithelium. Epithelial cells were absent along the medial edge of the palatal process in 48 hour cultures. Mesenchymal cells, not covered by a basal lamina, ultimately occupied the original position of the epithelial cells. Single palatal processes taken from spontaneous cleft A/Jax fetuses showed epithelial cell death along the medial edge similar to that in vitro, although an epithelial‐free surface was not observed. We interpreted these observations to indicate that epithelial cell disruption was an inherent process of medial palatal epithelium. This disruption was exaggerated during organ culture by the mesenchymal cells spreading on the filter membrane.
Electron microscopic observations on eosinophil leukocyte granules in dog blood
Authors: Hung Kuen‐Shan 
Published: February 2005

AbstractThe eosinophil granules of the dog have a dense matrix with or without a light peripheral rim. Lamellated crystalloids are demonstrated in their dense matrix. The lamellation consists of alternating dark and light bands resembling crystalloids of other species. The center to center distance between the consecutive dark bands measures approximately 107 Å. The crystalloids appear to take rather variable forms ranging from large, triangular to small, elongated or irregular shape.
Mast cells in the central nervous system of several rodents
Authors: Dropp John J. 
Published: February 2005

AbstractMast cells were detected in the brains of kangaroo rats, gerbils and albino rats. They were most numerous in diencephalic structures (leptomeninges, choroid plexuses, nuclei, tracts); moderately abundant in telencephalic and mesencephalic structures (leptomeninges, choroid plexuses, nuclei, tracts); and least plentiful in metencephalic and myelencephalic structures. They were not detected in the spinal cord. In all cases the mast cells were closely associated with the blood vessels in these regions.
In Vivo incorporation of choline‐3H, leucine‐3H and galactose‐3H in alveolar type II pneumocytes in relation to surfactant synthesis. A quantitative radioautographic study in mouse by electron microscopy
Authors: Chevalier Gaston , Collet Andre J. 
Published: February 2005

AbstractA quantitative time study of the incorporation of choline‐3H, leucine‐3H and galactose‐3H in lung epithelial cells, was undertaken in vivo with electron microscopic autoradiography. Type II pneumocytes were selectively labeled with choline‐3H, a specific precursor of phosphatidylcholine, which is the main component of pulmonary surfactant. Choline was initially localized in endoplasmic reticulum, then was rapidly transferred through the Golgi complex and stored in lamellar bodies. Previously undescribed small lamellar bodies are suggested as phospholipid carriers between Golgi complex and lamellar bodies. After initial incorporation in the endoplasmic reticulum, the leucine label migrated through the Golgi complex into lamellar bodies by fusion of multivesicular bodies, which are the carriers between the two structures. Galactose was modestly incorporated into lamellar bodies via the Golgi complex. Intra‐alveolar myelin figures, recognized as excreted surfactant, were labeled 120 minutes after injection with the three precursors.These findings indicate that the synthesis of a secretory product by type II pneumocytes involves phospholipid, protein and polysaccharide precursors; the secretory product is segregated as lamellar bodies which are destined to be excreted into the alveolar cavity to become part of the lining layer.
The fine structure of subarachnoid macrophages in the rat
Authors: Morse Dennis E. , Low Frank N. 
Published: February 2005

AbstractMacrophages associated with the subarachnoid space have fine structural characteristics which distinguish them from macrophages found elsewhere. The specific location of a macrophage in this area influences its morphology. Macrophages found in the subarachnoid space characteristically have a highly vacuolated cytoplasm. When cells of the pia mater separate the macro‐phage from the subarachnoid space, the extreme vacuolization is not present and a more compact cytoplasm prevails. Frequently macrophages found in the median longitudinal fissure contain compound reticulated inclusions. Extracellular bodies resembling compound reticulated inclusions have been observed.The presence of lobulated nuclei, lysosome‐like inclusions, phagosomes, and other characteristics of these cells is reported. The possible origin and function of subarachnoid space macrophages is discussed.
Quantitative studies on motoneurons: Hypoglossal neurons in the boa constrictor, Constrictor constrictor
Authors: Ulinski Philip S. 
Published: February 2005

AbstractThis study gives a quantitative description of hypoglossal neurons in the common boa, Constrictor constrictor. In this animal the hypoglossal nuclei are spatially distinct from the ventral horns and do not contain subnuclei. They contain a mean ± S.D. of 942 ± 162 neurons, many of which have double nucleoli. The neurons are shaped like prolate ellipsoids which are oriented with their long axes perpendicular to the ventricle. An average hypoglossal neuron has a major axis of 21.8 μ and a minor axis of 19.6 μ. Although neurons show a considerable range of sizes, neurons of different sizes are not segregated into different regions of the nucleus. Developmental differences in the size, distribution in the medulla, and the percentage of doubly nucleolated neurons occur, but the shape and orientation of hypoglossal neurons do not vary with age.
The ultrastructure of intradental nerves in developing mouse molars
Authors: Corpron Richard E. , Avery James K. 
Published: February 2005

AbstractThe purpose of this investigation was to study the nerves in mouse molar teeth during their development to observe their distribution and their relationship to the odontoblast and its process. The specimens were first assessed by light microscopy using silver staining techniques. It was found that by nine days after birth, major nerves appeared in the pulp organ and extended to the basal region of the odontoblasts. At 15 days, a subodontoblastic neural plexus had developed, and by 25 days, isolated nerves penetrated into the predentin of the pulpal horns. From 25–70 days, a highly organized subodontoblastic plexus was apparent with branches extending into the odontoblastic layer, predentin and inner dentin.Ultrastructural study revealed small, nonmyelinated nerves at the basal region of the odontoblasts by nine days. Both myelinated and small, nonmyelinated nerves appeared in the subodontoblastic plexus. Small nerves closely associated with the odontoblastic process were found within the predentinal tubules by 25 days. These processes contained occasional mitochondria, numerous microvesicles and small dark granules. From 35–50 days of age, similar nerves which exhibited alternate constrictions and dilations along their lengths were found in the tubules of circumpulpal dentin. By 60 days, both Schwann cell covered and naked axons appeared among the odontoblasts, and by 70 days Schwann cell covered axons appeared in predentin.
Spermatozoa in rouleaux in the female guinea pig genital tract
Authors: Martan Jan , Shepherd Benjamin A. 
Published: February 2005

AbstractSingle spermatozoa and spermatozoa in rouleaux were found throughout the genital tract of 21 female guinea pigs killed 15 minutes to 24 hours after copulation. Three females killed three to five minutes postcopulation had single spermatozoa and spermatozoa in rouleaux in the vagini, cervix, and uterus but not in the oviduct. The number of rouleaux and the number of spermatozoa in individual rouleaux decreased after copulation in all parts of the female genital tract with time while a corresponding increase in single spermatozoa was evident. The rate of rouleaux dissociation was faster in uteri than in oviducts. Only single spermatozoa were found near ova in the oviducts. The uterotubal junction appeared to act as a barrier to multitudes of spermatozoa passing from the uterus to the oviducts. However, some single spermatozoa and some rouleaux passed this barrier. Unusually large rouleaux were observed up to 12 hours after copulation in the pockets of the uterotubal junction. Single spermatozoa and few rouleaux of two spermatozoa in the uteri of females killed 8 to 24 hours postcopulation were phagocytised. No phagocytosis of spermatozoa was observed at any time in the oviduct.
Gross and light microscopic features of the pelvic plexus in the rat
Authors: Purinton P. T. , Fletcher T. F. , Bradley W. E. 
Published: February 2005

AbstractNerves and major accessory ganglia of the pelvic plexus are described from 12 rats perfused with methylene blue. Nerves to ventral and dorsal aspects of the urinary bladder, and three groups of nerves to the penis (clitoris) are reported in detail.Myelinated nerve fiber diameters ranged from 1–10 μ in the pelvic nerve and 1–6 μ in the hypogastric nerve. When the pelvic nerve was deafferentated, by spinal ganglionectomy 28 days previously, 80% of myelinated fibers degenerated, and the remaining fiber‐size spectrum resembled that of the hypogastric nerve. Myelinated fibers ranged from 1–7 μ in nerves to bladder and 1–3 μ in the lateral nerve to the penis. Myelinated fibers were afferent in these nerves, since spinal ganglionectomy eliminated all of them. In the main nerve to the penis, myelinated fibers ranged from 1–8 μ in diameter. A few fibers remained after deafferentation by spinal ganglionectomy. Since these were preganglionic efferent fibers, they indicate that terminal ganglia were present in the penis. All myelinated fibers degenerated with transection of pelvic and hypogastric nerves. The mode diameter of myelinated fibers was 2 μ in all pelvic plexus nerves.
Cellular reactions in a SRBC‐induced inflammatory exudate
Authors: Slonecker Charles E. 
Published: February 2005

AbstractAcute inflammatory exudates which are induced by the intra‐peritoneal injection of sheep red blood cells contain a variety of connective tissue cell types. Granulocytes, macrophages and lymphocytes constitute the vast majority of the exudate cells. The peritoneal macrophages are principally involved in the phagocytosis and clearance of the whole SRBC from the peritoneal cavity. The exudate lymphocytes which accumulate during the first 24 hours are derived from a pool with a fast turnover rate and are newly formed. While these lymphocytes undergo an enlargement and increase their basophilic cytoplasm during this response, they fail to show increases in their DNA synthesis while in the inflammatory exudate.
A wet‐lung technique for obtaining silastic rubber casts of the respiratory airways
Authors: Kilpper Robert W. , Stidd P. J. 
Published: February 2005

AbstractA technique for obtaining accurate casts of the bronchial tree and alveolar region is presented and several of the uncertainties involved in bronchial tree casting are discussed. Tompsett's basic casting technique is modified to use silicone rubber; supportive trays and a shape‐preserving gelatine injection are eliminated by suspending the lungs in a water bath. Fresh or frozen lungs may be used and prior fixation is not necessary. No elaborate apparatus, beyond usual laboratory items, is required. The slow, low pressure injection of rubber into the bronchial tree minimizes overdistension due to high translumenal pressures. The resulting cast is flexible and durable. Linear shrinkage is minimal with resulting volumetric errors of less than 2%. If desired, one may simultaneously inject the pulmonary arterial and venous systems with colored rubber, yielding a cast of greater educational utility.
Fine structural changes in the placental membrane of the marmoset with increasing gestational age
Authors: Jollie William P. 
Published: February 2005

AbstractMarmoset placentas were obtained surgically from early, mid and late pregnancy and examined with the electron microscope. At each stage both inner cytotrophoblastic and outer syncytiotrophoblastic layers were identified at the surfaces of the labyrinthine trabeculae. The trabecular cores contain very little connective tissue and are made up primarily of allantoic blood vessels of the peripheral umbilical circulation. Although a subepithelial basal lamina consistently is seen underlying the trophoblast, no subendothelial basal lamina has been identified at any stage. In early stages, the cytotrophoblast cells form a contiguous layer; consequently, the syncytium does not reach the basal lamina; and the placental membrane is hemodichorial. In the latest stage, since cytotrophoblast, though present, forms an interrupted layer and syncytiotrophoblast reaches the lamina, the membrane properly can be considered hemomonochorial. Not only in the gradual reduction in numbers of cytotrophoblast cells, but also in the fine structure of each constituent cellular layer, the membrane of this primitive anthropoid is strikingly like that of higher primates.