bluuebunny/crossref_metadata_2025_split huggingface dataset:
Speciation of butyltins in fish and sediment by means of gas chromatography with flame photometric detection
Authors: Martin‐Landa Isabel , Pablos Fernando , Marr Lain L 
Published: December 2004

AbstractA modified method for the determination of tributyl‐, dibutyl‐, and monobutyl‐tin in fish and sediment samples is proposed. The samples are digested with hydrochloric acid and the butyltin compounds are extracted into a tropolone solution in pentane and pentylated by a Grignard reaction. The products are cleaned up by washing with a sodium hyrdoxide solution, dried over sodium sulphate, concentrated by evaporation and analysed by gas chromatography with flame photometric detection, using an interence filter at 610 nm. Problems peculiar to the fish and sediment samples are overcome by this improved clean‐up procedure. The limit of detection for tributyltin in fish is 0.04 m̈g g−1 and the reproducibility at 0.06 μg g−1, expressed as the relative standard deviation, is 6.8%. Contaminated sediment samples were found to contain the mixed methylbutyl‐tin compounds Me2BuSn+ and MeBu2Sn+.
Synthesis of triphenyl‐phosphine, ‐arsine and ‐stibine derivatives of phenylmethinyltricobalt enneacarbonyls and their catalytic properties
Authors: Wang Yun‐Pu , Lei Zi‐Qiang , Feng Han‐Yu , Liu Yong‐Hong 
Published: December 2004

AbstractMono‐substituted triphenyl‐phosphine, ‐arsine and ‐stibine derivatives of phenylmethinyltricobalt enneacarbonyls PhCCo3(CO)8L (where L  PPh3, AsPh3 and SbPh3) were synthesized. The Co(2p3/2) binding energy (Eb) was lowered from 781.3 eV in PhCCo3(CO)9, to 780.0 eV in PhCCo3(CO)8PPh3, to 780.3 eV in PhCCo3(CO)8AsPh3 and to 780.5 eV in PhCCO3(CO)8SbPh3. Hydroformylation selectivity to total aldehyde and alcohol of the substituted clusters PhCCo3(CO)8L was about 100%, but that of the parent cluster PhCCo3(CO)9 was 93.8%. Hydroformylation products of styrene and di‐isobutene were the completely normal aldehyde when using PhCCo3(CO)8AsPh3 as catalyst.
Tetraethylammonium (diorgano)halogeno‐(2, 6‐pyridinedicarboxylato)stannates: Synthesis, characterization and in vitro antitumour activity
Authors: Willem Rudolph , Biesemans Monique , Bouâlam Mohammed , Delmotte Ann , Khloufi Abdelaziz El , Gielen Marcel 
Published: December 2004

AbstractThe synthesis and characterization of tetraethylammonium (diorgano)halogeno(2, 6‐pyridinedicarboxylato)stannates are described. The solution structures of these complexes in CDCl3 and DMSO are discussed on the basis of 119Sn and 19F NMR data. Their in vitro antitumour activities against two human tumour cell lines, MCF‐7 and WiDr, are presented.
The biotransformation of monomethylarsonate and dimethylarsinate into arsenobetaine in seawater and mussels
Authors: Cullen W R , Nelson J C 
Published: December 2004

AbstractWater‐soluble 3H‐labeled arsenic compounds were phenol‐extracted from mussels (Mytilus edulis) and seawater after exposure to [3H]monomethylarsonate (MMAA) and [3H]dimethylarsinate (DMAA). Varying amounts of [3H] arsenobetaine were found in mussels and seawater, depending upon the experimental conditions. The results indicate that arsenobetaine is principally biosynthesized by microscopic organisms in the seawater and that it is bioaccumulated by mussels. Total arsenic concentrations in mussel flesh, byssal threads and shells were also determined, showing concentration increases in all three compartments.
Development of the infundibulum of jungle fowl during incubation indicating neurohaemal role for this area
Authors: Graber Jean W. , Nalbandov A. V. 
Published: December 2004

AbstractAn area under the ependyma of the infundibulum in jungle fowl hens enlarges progressively during incubation. The structure is reduced in size and altered in appearance in laying hens, regressed in nonlaying hens, and absent in males. Enlargement of the structure does not depend on increasing or decreasing day length. The area did not enlarge in jungle fowl receiving injections of prolactin. No similar structure was found in incubating house sparrows, rock doves, or ring‐necked pheasant.Histological and histochemical examination of the enlarged area led to the tentative conclusion that it may represent a neurohaemal depot for ergones from the infundibular hypothalamic nuclei and may be evolved from a structure homologous with the neurohypophysis of lower vertebrates.
Synaptic patterns of the superficial layers of the superior colliculus of the rat
Authors: Lund Raymond D. 
Published: December 2004

AbstractAn electron microscopic study has been undertaken of the upper layers of the superior colliculus, into which run fibers from the retina and visual cortex. Study of the normal synaptic patterns shows large numbers of serial synapses, particularly near the surface of the colliculus. The presynaptic components usually contain round vesicles and the intermediate profiles always contain flattened vesicles. The latter may be dendrites, dendrite‐like or dilatations of such profiles. Degeneration studies indicate that optic terminals are especially dense near the surface and that they are often the presynaptic terminal of a serial synapse. Very few optic terminals occur in the stratum opticum. Cortical afferents from the visual area mostly end deep in the stratum griseum superficiale, and in superficial stratum opticum, usually on small clear profiles.Studies of the progress of degeneration indicate that optic terminals first show a predominantly neurofilamentous and associated glycogen reaction, and later a predominantly electron dense reaction. Cortical terminals show an initial dense reaction, with occasional neurofilamentous endings. These time course fit well with light microscope data from Nauta and Glees stained material.The synaptic patterns described here closely resemble patterns described in retina and dorsal lateral geniculate body. How these reflect functional similarities has yet to be resolved.
Observations on the postnatal development of clarke's column in the kitten
Authors: Smith Diane Elizabeth 
Published: December 2004

AbstractStudies on the postnatal development of Clarke's column were undertaken in order to ascertain if there were changes observed morphologically that would be compatible with the results so far reported both anatomically and physiologically on the afferent supply and the cerebellar end‐point of this system. The studies were carried out on the L.2 and L.3 segments of the spinal cord of kittens ranging in age from newborn to eight weeks. The principal staining methods employed were the Ha modification of the Golgi‐Cox, the Rasmussen technique for synapses, and Bodian's fiber stain. The sections were viewed using substage and reflected illumination.The most pertinent findings involved (1) the number of synapses and their distribution over the cell body and dendrites and (2) the number of stem dendrites and their orientation. There is an apparent lack of stainable synapses at birth, by eight days synaptic endings are present and by three weeks the entire cell is encrusted with two distinct types of synaptic end bulbs. Regarding the second point, a noticeable decrease was seen in the number of stem dendrites with a concomitant centripetal orientation of the dendritic tree in relation to the center of Clarke's column. The significance of these changes on the maturation of Clarke's column, on its afferent input and on the development of the dorsal spinocerebellar tract as a functional system is discussed.
Ventricular system of the brain of the dolphin, Tursiops truncatus, with comparative anatomical observations and relations to brain specializations
Authors: McFarland W. L. , Morgane P. J. , Jacobs M. S. 
Published: December 2004

AbstractA comparative and quantitative anatomical study of the cerebral ventricular system of the dolphin, Tursiops truncatus, and six other mammalian species, including man, has been made in the course of extensive neuroanatomical investigations of the dolphin. Several techniques have been used in these studies to confirm the morphological arrangement and contours of the ventricles. Casts of the ventricles were produced by use of a variety of casting media and methods and their relative merits were investigated and described. Following injection of the brain with casting media, the brain was either totally removed by dissection or digestion or one hemisphere dissected away to reveal the relationships of the ventricular cast to the opposite cerebral hemisphere. Serial sections of the brains of three dolphins were cut in three cardinal planes, and from these a model of the entire ventricular system was reconstructed. Serial sections (Nissl and Loyez) were also used to identify structures closely related to the ventricular cavities. Our results show that components of the cerebral ventricular system of the dolphin reflect, to a considerable degree, many of the specialized features of that brain including brachycephaly, widened and foreshortened temporal lobes, large limbic lobe, hypodeveloped frontal region, absence of an occipital pole, and massive development of the tectal acoustic apparatus. The morphological characteristics of the ventricular system and the relationship of this system to brain areas is discussed with respect to possible functional and phylogenetic implications.
Nerve endings in the urinary bladder of the cat
Authors: Fletcher Thomas F. , Hammer Robert F. , Bradley William E. 
Published: December 2004

AbstractUrinary bladders from mature cats, fixed in various degrees of distension, were studied with silver staining techniques under the light microscope, and with the electron microscope. Ganglia were located primarily in the adventitia, although small collections of perikarvons were located in nerves within the muscle coat. Large nerve trunks enclosed in perineural epithelium penetrated from the adventitia into the muscle coat, giving rise to smaller nerves which ran in the space between muscle fascicles. Small nerves entered each muscle fascicle, giving rise to final branches characterized by extreme tortuosity. There was less kinking and coiling of nerve fibers in bladders fixed in a more distended state. Encapsulated endings and myelinated fibers were scarce.Within a muscle fascicle, nerves were scant. Terminal branches intertwined among the individual smooth muscle cells as free nerve endings. Terminal axons continued to be ensheathed by Schwann cells. Neuromuscular synapses were characterizd by retraction of the Schwann cell from one side of the axon, presence of synaptic vesicles, and synaptic gaps of 400–600 Å. Areas of close contact between flattened and interdigitating parts of adjacent smooth muscle cells were common. Membrane complexes of pinocytotic vesicles and endoplasmic reticulum were distributed around the periphery of individual smooth muscle cells. Smooth muscles cells appeared to vary in the density of their myofilament content.
Projections from the orbital gyrus in the cat. II. To telencephalic and diencephalic structures
Authors: Mizuno Noboru , Clemente Carmine D. , Sauerland Eberhardt K. 
Published: December 2004

AbstractDirect projections from the anterior part of the orbital gyrus and its immediate vicinity to telencephalic and diencephalic structures in the cat were investigated by means of the Nauta and Marchi methods.Association fibers were observed to project to the ipsilateral coronal gyrus, the anterior part of the insular cortex, and the lateral part of the pericruciate gyrus. Degenerated fibers originating at the site of the lesion were traced to the callosal body, and from there chiefly to the contralateral putamen and the contralateral orbital and coronal gyri. Projection fibers to the telencephalic nuclei were found to terminate in the head of the caudate nucleus, the putamen, claustrum, and anterior amygdaloid area. Degenerated fibers in the external capsule were traced to the prepyriform area and the lateral part of the olfactory tubercle. Some of these components were observed to join the medial forebrain bundle and could be followed to the lateral preoptic area. Orbitothalamic fibers were traced through the anterior limb of the internal capsule and the internal medullary lamina. These fibers were found to terminate in the rostroventral part of the nucleus reticularis and ventralis anterior, and in the rostral parts of the intralaminal nuclei.
Structural characteristics of cell and fiber populations in the optic tectum of the frog (Rana catesbeiana)
Authors: Potter H. D. 
Published: December 2004

AbstractIn the optic tectum Cajal's method II for neurofibrils reveals two major fiber systems in which the fibers are oriented perpendicular to one another. The outer fiber system, composed of seven laminae, lies in the superficial zone with its fibers oriented in the anteroventral to posterodorsal direction; Golgi preparations show that optic tract fibers enter the outer system laminae at the tectal margin, run within single laminae, and end in arborizations that are elongated in the dominant fiber direction. The intermediate fiber system is composed of bundles of fibers in lamina 7 of Ramón and the superficial zone; its fibers are oriented in the anterodorsal to posteroventral direction. A third deep fiber system, forms fibrous laminae in the region between lamina 7 and the ependyma.In Golgi impregnations the deep cells are of two major classes: pyramidal cells with relatively narrow dendritic arbors in the superficial zone and candelabra cells with broad arbors. Many pyamidal cell dendrites have lamellar branching patterns such that terminal bushes occur within one or another of the outer system laminae. The multipolar cells within lamina 6 and lamina 7 of Ramón send large, unbranched axons directly into the deep medullary lamina and appear to be the major efferent neurons. Near the pia the perikarya of superficial granule cells give rise to single processes that branch repeatedly within the superficial zone.
Observations on the morphology of a nucleus in the dorsolateral funiculus of the spinal cord of the guinea‐pig, rabbit, ferret and cat
Authors: Gwyn D. G. , Waldron H. A. 
Published: December 2004

AbstractA nucleus was found in the dorsolateral funiculus of the spinal cord of the guinea‐pig. The nucleus extended from upper cervical to lumbar segments of the cord and was similar in appearance to that previously described in the rat. The nucleus also extended into lumbar segments of the spinal cord in both the rabbit and the ferret although in these species there were not as many cells in the nucleus in thoracic and lumbar segments of the cord as in the guinea‐pig. In the cat, the nucleus was confined to the upper two or three cervical segments of the spinal cord.
Ultrastructural differentiation of the junctional complex of the avian choroidal epithelium
Authors: Doolin Paul F. , Birge Wesley J. 
Published: December 2004

AbstractThe junctional complex of the choroidal epithelium of the adult domestic fowl consists of three characteristic components—the zonula occludens, zonula adherens and macula adherens. The quintuple‐layered zonula occludens (tight junction) occupies a juxtaluminal position and extends in depth from 0.2–0.4 μ. As a consequence of the intimate fusion of the outer leaflets of the apposed cell membranes, the tight junction is void of any discernible intercellular space. The zonula adherens normally varies in depth from 0.35–0.55 μ. Moderate to heavy accumulations of fibrillar and granular cytoplasmic material occur adjacent to the inner leaflets of the apposed cell membranes. These dense, cytoplasmic bands mesh with fibrillar elements of the general cytoplasm. The intercellular space of the intermediate junction is frequently attenuated by constrictions in the cell membranes. The tight and intermediate junctions appear to form continuous belts encircling each epithelial cell. The macula adherens (desmosome) is not especially well developed, usually lacking well developed cytoplasmic plaques.The early development of the zonula occludens is marked by the convergence of the apposed cell membranes, starting first at a localized point at or near the basal margin of the presumptive tight junction. Subsequently, convergence occurs at one or a few additional points, often near the middle of the developing tight junction. Finally, preparatory to membrane fusion, the adjacent cell membranes are brought into close apposition throughout the linear extent of the tight junction. Membrane fusion usually commences at or near the lower margin of the zonula occludens, in the area of initial membrane convergence, and then proceeds toward the luminal border.With the onset of membrane convergence, a network of fine fibrillar and granular cytoplasmic material accumulates adjacent to the inner leaflets of the apposed cell membranes. This cytoplasmic development subsides in the tight junction subsequent to membrane fusion but persists in moderate to dense accumulations in the other areas of the junctional complex. Numerous other associated events occurring during the differentiation of the junctional complex are discussed in detail.
Autoradiographic and histological studies of postnatal neurogenesis. III. Dating the time of production and onset of differentiation of cerebellar microneurons in rats
Authors: Altman Joseph 
Published: December 2004

AbstractIn one experiment rats were injected with single does of thymidine‐H3 at 6 hours, 2, 6 and 13 days of age, or with multiple doses during two periods of early life, and were killed when 2, 4 and 6 months old. In the autoradiographic analysis attention was focused on the time of origin and differentiation of basket, stellate and granule cells in different regions of the cerebellar cortex. In another, non‐radioactive study, in rats ranging in age from newborn to adult, the development of the cerebellum was studied with quantitative and qualitative histological techniques.In the sagittal plane the area of the cerebellum increases over 20‐fold from birth to 21 days. This increase is primarily due to the growth of the cerebellar cortex, much of the increment in the area of the subcortical regions occurring after 21 days. During the first week the growth of the different layers, excepting the proliferative external granular layer, is sluggish. During this period, the cells of the external granular layer do not differentiate but provide stem cells to this growing proliferative matrix. These proliferating and migrating cells of the external granular layer are the precursors of the basket, stellate and granule cells of the cortex; glia cells probably arise from cells multiplying locally. The first cells to differentiate are situated in the lower half of the molecular layer and include basket cells. Stellate cells differentiate later, with a peak at the end of the second week. The bulk of granule cells differentiate during the second and third weeks, with 25–80% of them, depending on the region, being formed between 11–21 days. These differences, together with several histological criteria (thickness of external granular and molecular layers, appearance of Purkinje cells) were used for constructing regional developmental maps of the cerebellar cortex. Granule cells differentiate in the depth of vermian fissures before they do over the exposed surfaces of the lobes; the ventral lobes (lingula and nodulus) mature before the anterior lobes; and the last maturing vermian lobes are the tuber, declive and culmen. The hemispheres, with some exceptions, mature later than the vermis, with the paraflocculus being among the last maturing structures.
Encapsulated nerve end‐organs in the rabbit, mouse, sheep and man
Authors: Straile William E. 
Published: December 2004

AbstractThere is a system of highly specialized blood vessels around each sensory hair follicle in the rabbit. The system includes two arteriovenous shunts and a cylinder of dilative blood vessels enclosed in a large bulbous capsule of connective tissue. The shunts, dilative blood vessels and capsule surround two cylinders of nerve fibers; together these structures constitute the largest neurovascular end‐organ in skin. The end‐organ is similar to the glomus‐Pacinian corpuscle complex in the hairless digital skin of man.The blood vessel cylinder and arteriovenous shunts in rabbit skin connect with a system of dilative blood vessels that are enclosed in another capsule of connective tissue under a small thick pad of sensory epidermis, beihnd the sensory hair follicle. The pad of epidermis contains expanded nerve fibers (Merkel's discs) that end near a cluster of Merkel (tactile) cells. In some regions of skin, each area of sensory epidermis is associated with the orifice of a sweat gland duct.In hairy skin of the rabbit, mouse and sheep, the areas of sensory epidermis, Merkel cells and Merkel's discs are distributed in parallel chains or in whorls and loops. Similarly, in the hairless skin of man the sensory epidermis, clusters of Merkel's discs and sweat duct orifices are distributed together in rows, whorls and loops that form the finger and palmer prints. In some regions of hairy human skin the same components occur together in small circular whorls called theHaarscheibenorRosetten.
Secondary olfactory projections in the galago (Galago crassicaudatus) and the tree shrew (tupaia glis)
Authors: Ferrer Nathaniel G. 
Published: December 2004

AbstractThe efferent projection fibers from the olfactory bulb have been studied using the Nauta‐Gygax and the Fink‐Heimer methods for degenerating axons after lesions were suitably placed by thermo‐coagulation. From the olfactory bulb efferent fibers by way of the ipsilateral lateral olfactory tract end as preterminal and terminal fibers in the lateral, the external and the ventral segments of the anterior olfactory nucleus; the lateral two‐thirds of the lateral olfactory tract, the cortical and the medial nuclei of the amygdaloid complex.
Dark profiles in the apparently‐normal central nervous system: A problem in the electron microscopic identification of early anterograde axonal degeneration
Authors: Cohen Elsa B. , Pappas George D. 
Published: December 2004

AbstractTissue taken from the ventrobasal thalamic nucleus of normal adult cats and examined in the electron microscope contained electron‐dense profiles which were morphologically indistinguishable from those seen in tissue from the same area of cats with dorsal column nucleus lesions of two and four days'duration. The number of dense profiles seen in some sections from normal material was greater than the number seen in any of the sections from lesioned material. It is proposed that such dense profiles may represent portions of the “dark” cells of light microscopy. Increased electron density is currently used as the major criterion in electron microscopy for recognizing certain types of experimentally‐induced anterograde axonal degeneration in the central nervous system. It is suggested, on the basis of the data presented here, that a careful review may be necessary of the validity of this criterion.