bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth in the basicranial synchondroses of adolescent Macaca mulatta
Authors: Giles William B. , Phillips Ceib L. , Joondeph Donald R. 
Published: February 2005

AbstractTritiated thymidine was administered to five Macaca mulatta monkeys ranging in skeletal age from 39 to 48 months. The animals were then serially sacrificed according to the following postinjection schedule: 6 hours, 12 hours, 2, 4, and 7 days. Each animal was given oxytetracycline 370, 103, and 7 days prior to sacrifice. The spheno‐occipital and midsphenoidal synchondroses were excised and sectioned midsagittally for histologic preparation and undecalcified “ground” sections. Results from this investigation indicate that from 39 to 48 months of age growth occurs primarily in the spheno‐occipital synchrondroses. The greatest mitotic activity occurs within the proliferative zones, while the central zone appears to be relatively inactive. The surface remodeling pattern, which tends to flex the basiocciput relative to the basisphenoid, appears to be compensated for by a supero‐inferior growth rate differential within the spheno‐occipital cartilage.
An ultrastructural morphometric study of developing rat substantia gelatinosa
Authors: Kirby M. L. 
Published: February 2005

AbstractA morphometric analysis has been done on developing rat substantia gelatinosa of the lower cervical and upper thoracic levels of the spinal cord starting on the 15th day of gestation. The following parameters were measured: cell body diameter, cytoplasmic/nuclear areas, synaptic density, synaptic type and vesicle morphology of the presynaptic terminal in axodendritic synapses. Cell body size and cytoplasmic/nuclear areas of gelatinosal cells increase until the 15th day postnatally and then decrease somewhat to the adult values. The first synapses are seen on gestation day 17. Synaptic density increases linearly until the third day postnatally. Axodendritic synapses are most common throughout development and in the adult, while the proportion of axoaxonic synapses increases and axosomatic synapses decreases during development. Most of the terminals in axodendritic synapses contain clear‐spherical vesicles but the occurrence of clear‐flat vesicles and dense‐cored vesicles in the terminals increases during development. It appears that these morphological parameters provide a stable index of development in the substantia gelatinosa which can be correlated with functional development of the area. Hopefully, they will provide a means to assess subtle anomalies induced by nonteratogenic drugs or other environmental changes.
Aqueductal tanycytes in the rabbit brain: A Golgi study
Authors: Burnett Bruce T. , Felten David L. 
Published: February 2005

AbstractUtilizing Golgi‐Cox impregnation, tanycytes were found in the ependyma of the cerebral aqueduct of the neonatal and adult rabbit. These tanycyte somas showed a variety of shapes, apical projections into the aqueduct, and basal processes (shafts) projecting into the mesencephalon, particularly into the periaqueductal gray (PAG). The shafts showed a variety of branching patterns, and sometimes abutted or terminated on capillaries or on specific neuronal elements. Other shafts coiled within the PAG or terminated within the neuropil of the mesencephalon. It is possible that these tanycytes provide a route for transport of cerebrospinal‐fluid‐borne substances from the aqueduct to the neuronal regions and vasculature of the mesencephalon. The presence of these tanycytes with complex branching patterns in proximity to neural and vascular structures suggests a permanent, active role for these specialized ependymal cells.
An interferometric analysis of nucleoli in cultured mesothelial cells
Authors: Blumenstein Robert , Amenta Peter S. 
Published: February 2005

AbstractPrevious studies have indicated that total nucleolar area and volume remain constant regardless of the number of nucleoli. The question remains whether this relationship is valid for mass. To answer this, total nucleolar mass values were obtained from nuclei of living mesothelial cells in culture possessing one to four nucleoli. The nucleolar mass was calculated using interferometry. The mean total nucleolar dry mass for cells with one, two, three, and four nucleoli was 40 × 10−12gm, 38.4 × 10−12gm, 39.1 × 10−12gm, and 41.4 × 10−12gm, respectively. These data suggest that on the average, each cell had approximately the same total nucleolar dry mass regardless of the number of nucleoli.In an additional study, interferometry was employed to reveal changes in nucleolar mass and concentration during a seven‐hour period. It was concluded that the nucleolus is a dynamic organelle, with its total mass varying in time from an average 40 × 10−12gm with a mean concentration of 22.2gm/100cm3.
The mechanism of AV junctional reentry: Role of the atrio‐nodal junction
Authors: Mazgalev Todor , Dreifus Leonard S. , Bianchi John , Michelson Eric L. 
Published: February 2005

AbstractMapping of atrial‐AV nodal (AVN) activation patterns was performed in 10 superfused rabbit AVN preparations utilizing 3 bipolar electrodes placed simultaneously at the crista terminalis (CT), interatrial septum (IAS) and His bundle (H) regions in close proximity to the AVN, along with two or three microelectrodes in the AN, N and NH regions of the AVN. Basic and premature stimuli were introduced at either or both the CT and IAS regions of the AVN. The timing of the premature stimuli was varied to induce close interaction of inputs to the AVN. Summation and/or cancellation, as evidenced by changes in the morphology of the action potentials and alteration of H1–H2 intervals, were observed. Apparent reentry phenomena could be induced or terminated by appropriately timed stimulation at the CT and IAS inputs. Reentry was critically related to both the patterns and timing of the spread of excitation within AVN and surrounding atrial tissue. Slow conduction and unidirectional block were observed in various portions of the reentry circuit. It is concluded that (1) interaction between input waves engaging the AVN produced either summation or fragmentation; (2) slow conduction and reentry resulted from a critical collision of wavefronts: (3) in this preparation, AVN reentry circuits always appeared to involve conduction through atrial tissue immediately surrounding AVN; and (4) remarkably, reentry confined to the intranodal region was never observed.
Efferent projections of the septum in the tegu lizard, tupinambis nigropunctatus
Authors: Sligar C. M. , Voneida T. J. 
Published: February 2005

AbstractA H3 proline or H3 leucine mixture was injected into the septal region of the Tegu lizard in order to determine its efferent projections. The brains were processed according to standard autoradiographic technique and counterstained with cresyl violet. Septal projections were limited to either telencephalic or diencephalic areas. Intratelencephalic projections consisted of efferents to medial pallium, nucleus accumbens, bed nucleus of the anterior commissure, preoptic area and septum itself. Fibers entering the diencephalon projected to medial habenular nucleus, dorsomedial thalamic nucleus, dorsolateral thalamic area, periventricular nucleus of the hypothalamus, lateral hypothalamic area and mammillary nucleus. The results are discussed in relation to the efferent projections of the septum in other vertebrates.
Structure and function of the murine muscle–tendon junction
Authors: Trotter John A. , Corbett Karen , Avner Barry P. 
Published: February 2005

AbstractThe muscle‐tendon junctions of the extensor carpi radialis longus and brevis muscles from adult Balb C Bailey/J mice have been examined tensiometrically and ultrastructurally following removal of cellular membrane and soluble cytoplasm by exposure to nonionic detergent. As judged by the ability of the extracted muscle to generate tension upon exposure to ATP and to transmit the generated tension to the tendon, detergent extraction leaves the muscle‐tendon junction functionally intact. Electron microscopic analysis of the extracted muscle‐tendon junctions reveals that the relationship between the terminal myofilaments and the lamina densa of the basal lamina is retained, despite the extensive extraction of the plasma membrane. Fine filaments (2–7 nm) are seen to connect the lamina densa with an electron‐dense intracellular layer into which terminal actin filaments appear to insert. These fine filaments are considered to represent an important component of the structural linkage between myofilaments and connective tissue and hence to be a significant component of the tension transmitting mechanism. Their precise nature is not known, but some part of the filaments must pass through the hydrophobic compartment of the plasma membrane and thus must be a transmembrane component of considerable tensile strength. These studies suggest that detergent‐extractable membrane lipids play no significant role in the transmission of tension at the muscle–tendon junction, and that fine filaments, probably protein, are responsible for transmitting tension from myofilaments, through the plasma membrane, to the lamina densa of the basal lamina.
Age related increase in catecholamine‐containing paraganglia in male fischer‐344 rats
Authors: Partanen Matti , Chiueh Chuang C. , Rapoport Stanley I. 
Published: February 2005

AbstractFor identification of paraganglia (PG), samples of para‐aortic tissue, tissues containing the coeliac‐mesenteric ganglion complex, and the hypogastric ganglia were removed from 3‐ and 33‐month‐old male Fischer‐344 rats and were processed by the formaldehyde‐induced fluorescence method for visualization of catecholamines. Small PG containing 5–30 cells per section were found consistently in young animals. In each of six old rats, large PG containing 500–4000 brightly fluorescent cells per section were detected. Cell counting revealed a 13.5 × increase in number of PG cells between 3‐ and 33‐month old rats. Microspectrofluorimetric quantitation in old rats showed equal amounts of catecholemines in PG cells and in adrenal medullary cells. Most PG were located in samples from the para‐aortic area.
A case of the left innominate vein passing behind the ascending aorta
Authors: Kitamura Seiichiro , Sakai Akira , Nishiguchi Takahiko 
Published: February 2005

AbstractThe authors observed the postaortic left innominate vein, which passed behind the ascending aorta, in the body of a 69‐year‐old Japanese male during dissection in 1979. In this case, no rudiment of the ordinary left innominate vein could be found in front of the arteries arising from the arch of the aorta. There are few reports of this anomaly and an extensive search of the available literature revealed only ten cases, including three in Japan. Adachi classified the postaortic left innominate vein into two types, types I and II, on the basis of the positional relation between the left innominate vein and the ligamentum arteriosum. Our case was of type I, in which the left innominate vein passed ventral to the ligamentum arteriosum and ran across from left to right behind the ascending aorta to join the right innominate vein. The embryological explanation which generally is accepted for the postaortic left innominate vein lies in the transposition of a transverse connection, which becomes the left innominate vein in a later stage of development, between the left and right anterior cardinal veins from the ventral to dorsal sides of the rudiment of the ascending aorta.
Nuclear bodies as structural indicators of estrogenic stimulation in uterine luminal epithelial cells
Authors: Padykula Helen A , Fitzgerald Maryellen , Clark James H. , Hardin James W. 
Published: February 2005

AbstractPreliminary evidence has indicated that the number of nuclear bodies in uterine luminal epithelial cells of the immature rat may be related to the duration of nuclear retention of the estrogen receptor complex (Clark et al., 1978). To test this hypothesis, an ultrastructural analysis of nuclear and cytoplasmic differentiation was performed at 4, 12, 24, 48, and 72 hr after a single injection of estradiol or nafoxidine (synthetic estrogen agonist/antagonist) into 21 day female rats. Variations in nuclear and cytoplasmic differentiation and in the frequency of occurrence of nuclear bodies (simple and complex) were determined and compared with established biochemical changes in the concentration of nuclear estrogen receptor and RNA polymerase activity (Clark et al., 1978). Following nafoxidine there is sustained elevation of the nuclear concentration of the estrogen receptor as well as RNA polymerase I and II activities over the entire 72‐hr period. From 4 to 72 hr the height of the luminal epithelial cells as well as the frequency of nuclear bodies increase at linear rates. Through steady expansion of the cytoplasmic membrane systems (RER and Golgi) the relatively undifferentiated epithelial cells of the control uterus are converted progressively into ones equipped for protein secretion. At 72 hr the effects of an estradiol implant resemble closely those observed after a single injection of nafoxidine; these include sustained nuclear receptor occupancy, elevated RNA polymerase activity, epithelial hypertrophy, and high frequency of nuclear bodies. However, after a single injection of estradiol, the luminal epithelial cells become slightly but significantly taller than the control cells and remain close to this size from 24 to 72 hr; the frequency of nuclear bodies decreases linearly from 4 to 72 hr to fall below the control level. In addition, limited cytoplasmic autolysis is evident from 24 to 72 hr. A single injection of estradiol results in short‐term nuclear receptor occupancy and elevated RNA polymerase activities which return to control levels by 24 hr. This collective evidence offers further support to the hypothesis that the duration of nuclear occupancy by the estrogen receptor is reflected in the size of the nuclear body populations in these epithelial target cells. Also during hyperestrogenization, epithelial hypertrophy is accompanied by steady formation of nuclear bodies.
Carbohydrate histochemistry of rat respiratory glands
Authors: Mochizuki I. , Setser M. E. , Martinez J. R. , Spicer S. S. 
Published: February 2005

AbstractCytochemical methods applied to examination of rat respiratory tract glands have revealed diversity of secretory complex carbohydrates. With the Alcian blue‐periodic acid Schiff (AB‐PAS) and the high iron diamine (HID) techniques at the light microscopic level, certain patterns of glycoprotein content were noted at various levels of the respiratory tract. Serous tubules and demilunes found in abundance in laryngeal and tracheal glands contained neutral glycoprotein. Mucous tubules found in abundance in epiglottal and laryngeal glands and in lesser number in tracheal glands most often produced sulfated glycoprotein. However, mucous tubules in epiglottal and tracheal glands contained a few cells with sialylated glycoprotein, and mucous tubules in some areas in laryngeal glands contained mainly cells producing sialylated glycoprotein. Mucous ducts found in abundance in lower laryngeal and tracheal glands formed mainly sialylated glycoprotein and contained infrequent cells with sulfated glycoprotein. The type of glycoprotein found in each cell type by light microscopy was confirmed at the ultrastructural level by the periodic acid‐thiocarbohydrazide‐silver proteinate (PA‐TCH‐SP), dialyzed iron (DI) and high iron diamine (HID) methods. Serous cell granules displayed light reactivity with the PA‐TCH‐SP method and no DI or HID affinity and were judged to contain sparse neutral glycoprotein. Serous granules disclosed negative central foci with the PA‐TCH‐SP method. Granules of most mucous tubule cells stained strongly with the PA‐TCH‐SP and HID procedures and contained abundant sulfated glycoprotein. Occasional mucous tubules stained with the PA‐TCH‐SP but not with the HID method and apparently corresponded with cells judged to form sialylated glycoprotein from their blue staining with the HID‐AB sequence. Two zones within individual granules in some cells revealed different HID staining intensity and appeared to differ in the amount or kind of sulfated glycoprotein they contained. Some cells exhibited granule heterogeneity containing both HID‐positive and unstained granules. Spherical cores present in granules of mucous tubules below the upper laryngeal level occasionally appeared bizonal and invariably lacked reactivity demonstrative of complex carbohydrate. Mucous duct cell granules stained heavily with the PA‐TCH‐SP and DI methods and reacted infrequently with the HID procedure and were considered generally to contain sialylated glycoprotein, and occasionally to form sulfated glycoprotein. The three carbohydrate stains distinguished a heavily and a moderately reactive zone in the cortex outside the monophasic or biphasic, carbohydrate‐free cores in granules of some mucous duct cells.
Electron microscopic studies on the potential loss of crystallites from routinely processed sections of young enamel in the rat incisor
Authors: Bishop M. A. , Warshawsky H. 
Published: February 2005

AbstractNewly formed rat incisor enamel was fixed aqueously by perfusion with glutaraldehyde and anhydrously by immersion in ethylene glycol. Ultrathin sections were studied using transmission electron microscopy and electron diffraction. Aqueously processed enamel was shown to lose its mineral content when sectioned on distilled water. This mineral loss was minimized by limiting the exposure of sections to the water. In such preparations, enamel crystallites were seen by virtue of their intrinsic electron density only. Selected area electron diffraction provided corroborative evidence for the presence or absence of crystallites in the sections. Observations on mineralized sections and on stained mineralized and distilled‐water‐demineralized sections revealed organic material apparently in the same location as the crystallites. Anhydrously processed enamel which was sectioned on ethylene glycol showed a similar appearance of the crystallites. This appearance was not obviously altered after staining despite evidence that organelles in the ameloblasts were stained. In view of the observations that both methods yielded similar crystallite morphology, it was concluded that aqueous techniques can be used to study the relationship between organic and inorganic components. However, valid description of crystallites in such preparations requires minimal exposure of ultrathin sections to water.
Ultrastructural demonstration of chemical modification of melanogenesis in hairless mouse skin
Authors: Nishimura Masayuki , Gellin Gerald A. , Hoshino Shimpei , Epstein John H. , Epstein William L. , Fukuyama Kimie 
Published: February 2005

AbstractWe investigated chemical and physical modifications of the genetically determined ultrastructure of melanosomes. The flank skin of hairless mice was treated with ultraviolet energy (UV) shorter than 320 nm or with a combination of a photosensitizer and UV (PUVA treatment). All melanosomes in the induced melanocytes and those in resident melanocytes in the ear skin showed eumelanogenesis, although the degree of melanin deposition differed considerably according to the induction process. Eumelanogenesis was most advanced in the resident melanocytes while PUVA‐induced melanocytes showed more immature premelanosomes. We then topically applied 4‐tertiary butyl catechol on the skin. The depigmenting agent caused an appearance of pheomelanosomes. The alteration in melanogenesis was seen most distinctly in premelanosomes of the PUVA‐induced cells. Altered ultrastructure was also observed in matured melanosomes; this change was most apparent in the resident melanocytes. These findings indicate that cells with eumelanogenesis may undergo pheomelanogenesis. The present study demonstrated effects of chemicals on genetically determined function of melansome ultrastructure.
Ethanol‐induced alterations in the morphology and function of the rat ovary
Authors: Bo Walter J. , Krueger Wayne A. , Ruenen P. Kevin , Symmes Sandra K. 
Published: February 2005

AbstractThe purpose of this study was to compare the effects of different dosages of ethanol on ovarian morphology and function. Holtzman rats, 20 days old, were divided into groups as follows: The rats in Group I were autopsied at 20 days of age, and those in Group II were placed on ad libitum chow and water diet; the rats in Groups III and V were fed on a liquid diet containing 2.5% or 5% ethanol respectively; Groups IV and VI were pair‐fed controls to Groups III and V, respectively. Rats in Groups II, III, IV, and VI were maintained on the diets for 50–55 days and killed at late proestrus‐estrus, while the animals in Group V did not exhibit estrous cycles and were killed on day 55 of treatment. The average increase in body weights of rats in Groups II, III, and IV was significantly greater than the increase in body weights of rats given 5% ethanol or their pair‐fed controls. In the rats treated with 5% ethanol, vaginal opening was significantly delayed from the controls, estrous cycles were absent, ovarian weights were similar to those of the 20‐day‐old rats, ovaries contained corpora lutea of only one estrus, uteri weighed less than controls, and histologically, the uteri and vaginae were similar to those of 20‐day‐old rats. However, in the rats treated with 2.5% ethanol, all of the parameters were similar to those of the controls. The average serum alcohol level for the rats on the 5% ethanol diet was 249 mg%; the serum alcohol levels were at the lower limit of detection for the rats on the 2.5% ethanol diet. The data show that ovarian function was suppressed in the rats that received the 5% ethanol but not in rats on the 2.5% ethanol diet.
Comparative fine structure of the osteichthyan dermotrichia
Authors: Geraudie Jacqueline , Meunier Francois‐Jean 
Published: February 2005

AbstractThis study shows that camptotrichia constitute the only skeleton of the Dipnoan fins. Their fine structure is indeed quite different from the two other Osteichthyan dermotrichia, namely the actinotrichia and the lepidotrichia found simultaneously in the fin margin of both Actinopterygians and Crossopterygians fins. Although different from lepidotrichial bone, the fine structure of camptotrichia is more reminiscent of it than of the elastoidin‐formed actinotrichia.
Defective thyroid ontogenesis in fetal hypothyroid (hyt/hyt) mice
Authors: Beamer Wesley G. , Cresswell Lisa A. 
Published: February 2005

AbstractThyroid glands of fetal hypothyroid (hyt/hyt) mice were studied to determine the effects of the mutant gene during embyrogenesis. Comparisons of mutant and normal thyroids were made with respect to morphology, iodine‐concentrating ability, and glandular thyroxine (T4) content at day 18 of gestation. Fetal hyt/hyt thyroid tissue was properly located, but incompletely differentiated. The mutant thyroid was characterized microscopically by small, poorly developed follicles with colloid diminished in PAS‐staining properties. The mutant glands' ability to concentrate iodine was found to be only 5–16% of that exhibited by normal glands. When litters contained both mutant and normal offspring, the differential iodine‐concentrating ability allowed fetuses to be separated into two distinct, nonoverlapping populations. The distribution of fetal mice into high or low iodine‐concentrating groups agreed closely with predicted frequencies for normal and mutant phenotypes. Thyroid content of T4 in mutant mice was found to be approximately equal to that found in age‐matched normal controls.The poorly developed morphology and deficient iodine‐concentrating ability of fetal thyroids from day 18 hyt/hyt mice indicated that the mutant gene acts during the ontogeny of this gland. Although such data are not available on human fetuses affected by thyroid dysgenesis, postnatal hyt/hyt mice display characteristics similar to those of infants born with this form of congenital primary hypothyroidism. Thus, elucidation of the site of mutant gene action in the mouse should contribute to our knowledge of disturbed fetal thyroid development and its implications in the adult mammal.