bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of temperature differentials upon the differentiation of Mauthner's cell in Ambystoma
Authors: Piatt Jean 
Published: February 2005

AbstractEggs of Ambystoma maculatum were separated into three groups and maintained at 5°, 8° and 14°C, respectively, until stage 27. At this stage the otic vesicle was extirpated from the right side, thus eliminating the VIIIth cranial ganglion and root. The number of cases in which Mauthner's cell (MC) failed to differentiate in the absence of VIIIth roots was compared among the three temperature groups.In a total of 713 animals, MC was absent on the side of operation in 200 cases (28.05%). Comparison of the three temperature groups with respect to the absence of MC is as follows: 14°, 39 of 212 cases (18%); 8°, 83 of 266 cases (31%); 5°, 78 of 235 cases (33%). Statistical analysis of these data demonstrates a significant difference between either one of the colder groups and the 14° group with regard to suppression of MC. When the two colder groups are tallied as a single sample, the difference is even more significant. There is no significant difference between the 5° and 8° groups. These results indicate that the differentiation of MC is more dependent upon the ingrowth of VIIIth root fibers when morphological development has been delayed by prolonged hypothermia.
Extracellular lining of bronchioles after perfusion‐fixation of rat lungs for electron microscopy
Authors: Gil Joan , Weibel Ewald R. 
Published: February 2005

AbstractRat lungs were fixed by perfusion of fixatives through pulmonary vessels which resulted in good fixation of bronchioles. This technique allows the preservation of a hitherto not described extracellular lining of the bronchiolar surface, which by conventional fixation (immersion or instillation of the fixatives into the airways) is washed out. The cilia appear to be embedded in an extra‐cellular, amorphous material. This material is often lined at its surface by a strongly osmiophilic layer. Tubular myelin figures can also be identified. Comparison with recent physiological and biochemical work, which establishes the presence of surface‐active material in the airways, strengthens the conclusion that this layer is related to bronchiolar “surfactant” fixed in situ. A mixed origin of this material from the Clara cells and from the alveolar surface lining layer is suggested.
An electromyographic study of the mylohyoid muscle
Authors: Lehr Robert P. , Blanton Patricia L. , Biggs Norman L. 
Published: February 2005

AbstractAn electromyographic investigation of the mylohyoid muscle was undertaken to determine its activity relative to isolated movements of the tongue and mandible and during various functions involving multiple parts of the oral apparatus. Data was obtained from 20 subjects. Using bipolar fine‐wire electrodes, the anterior fibers were found to be more active than the posterolateral fibers in a majority of activities performed. Tongue movements produced slightly more activity in the postero‐lateral fibers; the anterior fibers were more active during mandible movements. During mastication, deglutition, sucking and blowing, both the anterior and postero‐lateral fibers were markedly active.
Ultrastructural changes in the cell cycle of cultured melanoma cells
Authors: Hu Funan 
Published: February 2005

AbstractThe fine structure of the synchronized cultures of B16 melanoma cells at different days of incubation was studied.Our observations demonstrate that the endoplasmic reticulum first develops in the dividing cells as simple flattened smooth cisternae, which become paired or multilamellated during nuclear reconstruction and form annulate lamellae as well as typical endoplasmic reticulum with ribosome‐studded membranes in the postmitotic and interphase cells.The presence of both premelanosomes and melanosomes in dividing cells is unequivocal evidence that functionally mature melanocytes are capable of proliferation.
Osmium‐zinc iodide reactivity in human blood and bone marrow cells
Authors: Clark Michael A. , Ackerman G. Adolph 
Published: February 2005

AbstractBuffy coats from blood and bone marrow were fixed in phosphate‐buffered glutaraldehyde, exposed to the osmium‐zinc iodide (OZI) reagent for 24 hours, dehydrated and embedded in Epon 812. OZI reactivity of blood and bone marrow cells was selectively confined to the cisternae of the rough endoplasmic reticulum (RER), Golgi complex, nuclear envelope and to the mito‐chondrial matrices; membranes and other organelles were non‐reactive. Some variation in intensity and distribution of OZI reactivity was evident within individual cells and organelles. Continuities between the cisternae of the nuclear envelope and RER as well as between these cisternae and those of the Golgi complex were more conspicuous in OZI preparations than in specimens prepared for routine electron microscopy.The amount and distribution of the cisternal elements and mitochondria within the developing leukocytes and erythrocytes of the bone marrow were evaluated using the OZI technique. All leukocyte granules and their precursor forms fail to stain with the OZI reagent; portions of the Golgi complex most closely associated with the packaging of the cytoplasmic granules also are non‐reactive following exposure to the OZI reagent. Reactivity is absent in mature erythrocytes while mitochondria and cisternal components of immature erythroid cells yield positive OZI reactions. Heat, methanol and cyanide inhibit OZI reactivity while a dimorphism of OZI staining is induced between mitochondria and cisternal components by N‐ethylmaleimide.
Mineralized spherules in the cells and matrix of calcifying cartilage from developing bone
Authors: Kashiwa Herbert K. , Komorous James 
Published: February 2005

AbstractFresh tibias and occipital bones from newborn mice and rats, as well as from 18‐day‐old mouse and chick embryos, were stained with 10% GBHA and 5% AgNO3solutions to localize calcium and phosphate or carbonates in sphenules within the cytoplasm of chondrocytes and in the matrix of the calcifying cartilages. The mineralized spherules in the matrix adjacent to the hypertrophied chondrocytes were approximately 0.5 to 1 μ in diameter. This was comparable in size to the spherules found within the cytoplasm of the chondrocytes. The spherules within the core of the spicules distal to the hypertrophied chondrocytes were about 2–3 μ in diameter. The larger spherules were shown to contain an organic core which stained metachromatically with toluidine blue and was also stained with aldehyde fuchsin. The spherules were not visible after PAS reactions due to the intense staining. The labile GBHA and silver acetate positive spherules localized in the chondrocytes may be the source of the extracellular mineralized spherules.
The fine structure of the mouse adrenal cortex and the ultrastructural changes in the zona glomerulosa with low and high sodium diets
Authors: Shelton James H. , Jones Albert L. 
Published: February 2005

AbstractThe ultrastructure of the normal mouse adrenal cortex and the zona glomerulosa as stimulated by sodium restriction and repressed by high salt intake is reported. The mitochondria are zone specific, the endoplasmic reticulum tubular and the endothelium fenestrated. An intimate relationship between elements of reticulum, mitochondria and lipid droplets is seen in all animals. The rough reticulum is poorly developed in all but the glomerulosa of salt‐restricted animals. The Golgi apparatus, associated vesicles and surface microvilli are relatively more developed in the inner cortical zones and in the glomerulosa cells of stimulated animals, whereas surface coated pits and vesicles do not vary. Lysosome‐like granules are more prominant in the control reticularis and in the glomerulosa of animals on high salt intake.In stimulated glomerulosa cells, there is an early depletion of lipid droplets and a transient increase in rough reticulum followed by a progressive increase in smooth reticulum and Golgi apparatus. At three weeks, the lipid droplets are restored. In repressed glomerulosal cells, there is atrophy of the cytoplasmic organelles while lipid droplets are increased in number and osmiophilia. An accompanying feature is the appearance of cytoplasmic β‐glycogen. These observations are discussed as to their relation to adrenocortical steroidogenesis and secretion.
Alkaline phosphatase in rodent secondary palate development. A histochemical and biochemical study
Authors: Sweney L. R. , Shapiro B. L. 
Published: February 2005

AbstractAlkaline phosphatase (AlPase) has been examined histochemically and biochemically in Swiss White (SW) mouse and Sprague‐Dawley (SD) rat embryos during comparable stages of secondary palatal development. In the rats, AlPase was not detectable histochemically until after shelf transposition. Enzyme activity by biochemical assay was low in stages before shelf elevation. The mice, in contrast, showed AlPase in posterior areas of the developing shelves soon after shelf formation by histochemical techniques. With biochemical assays AlPase was higher in mouse than in rat shelves in early stages. After shelf transposition AlPase activity in the rat approached AlPase activity in the mouse by biochemical assays, but was demonstrable only in the posterior areas of the secondary palate by histochemical techniques.
Quantitative studies of the greater petrosal nerve of the mouse with the electron microscope
Authors: Shimozawa Atsumi 
Published: February 2005

AbstractQuantitative counts of the greater petrosal nerve fibers of the mouse with the electron microscope have shown that, on an average, 70.8% and 28.7% of the total nerve fibers (1,111) were unmyelinated and myelinated fibers respectively. Unexpected high incidence of unmyelinated fibers in the greater petrosal nerve may indicate that it contains a fair amount of sympathetic post‐ganglionic fibers. The unmyelinated fibers in the nerve may well represent parasympathetic preganglionic fibers.
Satellite cells as the source of nuclei in muscles of growing rats
Authors: Moss F. P. , Leblond C. P. 
Published: February 2005

AbstractThe source of the new nuclei appearing during the growth of muscle fibers was examined in the tibialis anterior muscle of young Sherman rats (14–17 days of age) using radioautography at various intervals after a single injection of a small, non‐toxic dose of 3H‐thymidine (2 μCi/g body weight). Two techniques were employed: (1) labeled nuclei were detected in 1 μ thick radioautographs examined in the light microscope, and identified by simultaneous electron microscope examination of an adjacent section. The nuclei were then classified either as “true” muscle nuclei (within the plasmalemma of the fibers) or as belonging to “satellite cells” (which are mononucleated cells with scanty cytoplasm wedged between plasmalemma and basement membrane). (2) Muscle fibers freed by collagenase digestion were radioautographed one hour after 3H‐thymidine injection in order to determine the total number of labeled nuclei (true muscle nuclei plus those of satellite cells) per unit length of fiber.Certain nuclei within the basement membrane of muscle fibers are labeled one hour after 3H‐thymidine and, therefore, synthesize DNA. The electron microscope demonstrates that these nuclei invariably belong to satellite cells, never to true muscle nuclei. Furthermore, the total number of labeled nuclei per unit length of fiber doubles between 1 and 24 hours; and, therefore, the labeled satellite cell nuclei undergo mitosis.Following mitosis, half of the daughters of satellite cells are incorporated into the fibers to become true muscle nuclei. The remaining half divides again later; and half of their daughter cells are incorporated. Thus, satellite cells in young rats divide repeatedly and function as a source of true muscle nuclei.
Ultrastructural changes in mouse yolk sac associated with the initiation of vitelline circulation
Authors: Haar Jack L. , Ackerman G. Adolph 
Published: February 2005

AbstractThe endodermal cells of the visceral yolk sac have been studied from the seventh to eleventh day of gestation. The absorptive capacity of the cells is established by the seventh day as indicated by the presence of microvilli, coated invaginations and vacuoles, the apical canalicular system and abundance of absorptive droplets and vacuoles in these cells. Changes in cellular structure during the next three to four days include the development of the cisternal system of the rough endoplasmic reticulum, an increase in mitochondrial number and their localization near absorptive droplets and the formation of multiple Golgi complexes. Intercellular spaces form between the endodermal cells by eight to eight and one‐half days and coincide with the disappearance of the basal lamina separating the endoderm and mesoderm (angioblastic cords); these changes correlate with the formation of the vitelline vessels. As the vitelline circulation becomes functional, the visceral basal lamina is re‐established, the intercellular clefts decrease in prominence and the absorptive storage droplets and vacuoles decrease in size and number.The apical junctional complex of the endodermal cells forms a continuous barrier for the direct passage of material from the yolk sac cavity to the developing vitelline vessels as established by the use of ruthenium red. The absorption and intracellular storage of macromolecules in the visceral endodermal cells was traced through the intermicrovillous apical coated invaginations, coated vesicles, apical canaliculi and storage vacuoles using ferritin.Immunofluorescent studies indicate the presence of immunoglobulin (anti‐mouse gamma globulin) in the cytoplasm of the visceral endodermal cells as early as 9 to 11 days. Several blast‐like cells which also were observed in the vitelline vessels at 11 days exhibited positive fluorescence for immunoglobulin.
An electron microscopic study of mouse eggs matured in vivo and in vitro
Authors: Merchant Horacio , Chang M. C. 
Published: February 2005

AbstractMouse oocytes obtained at various times after administration of HCG or after culture were studied with the electron microscope. Gradual changes were observed in the perivitelline space, plasma membrane and cortical cytoplasm. Disappearance of the regular microvilli, the formation of lamellae‐like processes and vesicular bodies were observed. A progressive increase in the number of cortical granules and multivesicular complexes was observed simultaneously with the disappearance of the rough endoplasmic reticulum. In general, eggs which were matured either in vivo or in vitro showed similar patterns of morphological differentiation. Degenerative changes were seen in most eggs cultured for 17 hours, but not for nine hours or less. In aged tubal eggs recovered at 26 and 36 hours after injection of HCG, the number of cortical granules was decreased relative to previous stages and their extrusion from the egg was apparent. The fertilizability of the eggs matured in vitro and the role of the cortical granules are discussed in terms of the reaction of the zona pellucida.
Dendrite bundles in Lamina IX of cat spinal cord: A possible source for electrical interaction between motoneurons?
Authors: Matthews Murray A. , Willis William D. , Williams Vick 
Published: February 2005

AbstractLongitudinally‐oriented bundles of closely‐aligned motoneuron dendrites in Lamina IX of cat spinal cord were examined. These dendrites were interrelated in one of several ways: (1) They were separated by a space of several microns containing small myelinated and unmyelinated fibers, synaptic boutons, and glial processes; (2) Some dendrites were separated by a gap of 0.2–0.5 μ which contained only an attenuated astrocyte process; (3) The plasma membranes of the adjacent dendrites were occasionally found in direct apposition and in most of these instances there was no detectable specialization of the opposing membranes; (4) There were definite modifications along the appositional membranes. These zones were characterized by a gap of ∼ 180 Å, and symmetrical, non‐polarized aggregations of electron‐opaque material were found along the cytoplasmic surfaces of the membranes.It is suggested that the spatial arrangement and appositional relations of these dendrites represent a morphological substrate for the weak electrical facilitation known to occur between motoneurons in the cat spinal cord.
Structure of mammalian portal vein: Postnatal establishment of two mutually perpendicular medial muscle zones in the rat
Authors: Ts'ao Chung‐Hsin , Glagov Seymour , Kelsey Billy F. 
Published: February 2005

AbstractIn all mammalian species examined thus far, the media of the adult mammalian portal vein consists of two mutually perpendicular smooth muscle zones separated by a fibrous layer. The cells of the muscle zone nearest the intima are arranged circumferentially and resemble smooth muscle of other vessels; the muscle cells of the thicker, vascularized outer zone are longitudinal and contain mitochondria and pinocytotic vesicles in great abundance, suggesting relatively high metabolic activity. The adult configuration is not present at birth and only develops during the first three postnatal weeks in the rat. Partitioning of the media commences at about three days and contrasting orientation and composition of the cells of the two muscle zones is not established until seven to ten days after birth. Vasa vasorum appear in the outer muscle layer at about two weeks and nerve fibers appear even later. Post‐natal establishment of a special, double layered neuromuscular structure may be related to the adaptation of the portal circulation to the effective closure of the ductus venosus.
Adjustment of the myelin sheath to changes in axon caliber
Authors: Friede Reinhard L. , Miyagishi Tsutomu , Johnstone Millicent 
Published: February 2005

Abstract“Chronic” axon swellings were produced by applying a snug ligature around the sciatic nerve of rats by the fourteenth postnatal day, allowing the nerve to compress itself by its subsequent growth. The technique results in swelling of the entire myelinated fiber population proximal to the constriction, and in hypoplasia or arrested growth distal to it. “Chronic” axon swellings differed strikingly from the “reactive” axon swellings in the stumps of transected nerves in having normal or slightly below normal concentrations of axoplasmic organelles, including mitochondria and smooth endoplasmic reticulum.Swelling of the axons was associated with attenuation of their sheaths having normal interperiod width but fewer turns of myelin lamellae than found in normal fibers of comparable calibers. Release of the compression resulted in rapid restitution of axon swellings; the excess axoplasm was drained from the fibers and the sheaths rapidly acquired normal thickness. The magnitude of all observed changes in the sheaths of swollen and of restituted fibers was consistent with a rearrangement of the existing turns of myelin lamellae without change in the total amount of myelin. The myelin sheath appears capable of adjusting to both increases or decreases in axon size by slippage of its lamellae.
The anterior buccal gland of the Rat: A mucous salivary gland which develops as a branch of stensen's duct
Authors: Redman Robert S. 
Published: February 2005

AbstractExamination of serial histologic sections of the head and neck regions of rats at selected age intervals from 14 days in utero to 100 days postnatally revealed that at 16 days in utero, a second salivary gland arises from the rudimentary parotid (Stensen's) duct. This gland develops more rapidly than the parotid gland; its acini are essentially mature prior to weaning, preceding parotid acini in this respect by several days. All cells of the secretory units of the mature gland stain positively with both alcian blue and periodic acid‐Schiff, indicating that the gland is of pure mucous type. The body of the gland occupies a space lateral and mostly superior to the maxillary buccal sulcus, nestled beneath the anterior bulge of the masseter muscle, near the point where the buccal and mandibular marginal branches of the facial nerve cross paths. It is the only salivary gland in the buccal wall anterior to the third molar; hence, the proposed name of anterior buccal gland. These observations suggest: (1) Samples of rat parotid saliva collected proximally and distally to the junction of the ducts of the parotid and anterior buccal glands are likely to differ significantly in the quality and quantity of mucosubstances which they contain. (2) The divergent differentiation of two branches of the same glandular primordium in this instance implies differences in the inductive qualities of their respective mesenchymal beds.
Epithelio‐mesenchymal interactions in primordial gland structures which become responsive to androgenic stimulation
Authors: Cunha Gerald R. 
Published: February 2005

AbstractThe morphogenetic tissue interactions between epithelium and mesenchyme of male accessory sexual gland primordia were investigated by standard culture methods. Seminal vesicle (SV), urogenital sinus (UGS), and preputial gland (PP) rudiments were excised from 13‐ to 19‐day old embryonic mice. After tryptic‐separation, the epithelium and mesenchyme of these rudiments were recombined into control (homotypic) and experimental (heterotypic) recombinants which were subsequently grown in the anterior chamber of the eye of adult male hosts.In recombinants composed of accessory sexual gland epithelium (SV, UGS, or PP) and urogenital gland mesenchyme (SV or UGS), the histotypic pattern of the recombinants reflected the source of the epithelium. Normal differentiation of SV, UGS, and PP epithelium occurred consistently when these epithelia were associated with SV or UGS mesenchyme. On the other hand, urogenital gland epithelium (SV or UGS) did not develop normally when associated with the integumentally‐derived preputial gland mesenchyme. Instead, seminal vesicle epithelium was maintained as a columnar epithelium arranged in a simple tubular structure, while urogenital sinus epithelium formed a keratinized epithelium despite the presence of androgens. These data illustrate (1) the supportive properties common to urogenital mesenchyme, (2) the stability of accessory sexual gland epithelium, and (3) the lack of strict mesenchymal requirements of these epithelia. Furthermore, the data suggest that urogenital and integumental mesenchyme differ significantly in their ability to mediate hormonally‐dependent developmental processes.
Autoradiographic and chemical localization of 5‐hydroxytryptamine in identified neurons in the leech
Authors: Coggeshall Richard E. 
Published: February 2005

AbstractThe large leech neurons known as Retzius cells contain substantial amounts of 5‐hydroxytryptamine (5‐HT) stored in granules. Previous studies show that these cells are able to make 5‐HT from precursors. The present study, which is a combined chemical and autoradiographic analysis of these cells after the administration of radioactive 5‐HT or 5‐HTP, confirms that the cells make 5‐HT from precursors. In addition, this study shows that the cells can acquire and store 5‐HT when it is present in the environment. Thus, if 5‐HT is available, these cells need not manufacture this compound from precursors. Furthermore, the newly acquired 5 HT seems to be stored in the granules that characterize these cells. Finally, this study shows that the Retzius acquire or make the 5‐HT in vivo.
The trigeminal nerve in the baboon
Authors: Gasser Raymond F. , Miller Wise D. 
Published: February 2005

AbstractThe definitive course, relations, branches and communications of the extramedullary part of the trigeminal nerve in baboons are described and illustrated. The nerve was dissected in five animals and the location of all related parasympathetic ganglia was verified microscopically. Variable branching patterns were observed in some areas of the nerve field. Comparisons are made with other primates including man.