ISSN:0002-9106    

DOI:10.1002/aja.1001370202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1973

数据来源: WILEY

摘要:

AbstractThe ramification of the pancreatic arteries, including the lobular vessels, was studied in 36 mongrel dogs by means of plastic injection and corrosion, as well as microangiography.The left pancreatic lobe receives the left cranial pancreatic artery and other smaller branches from the splenic artery, and two to four twigs from the gastroduodenal artery. In addition, it receives very often a branch from the common hepatic artery. Branches arising from the cranial mesenteric artery and from the first jejunal artery may also be found. The right cranial pancreatic artery and the right gastroepiploic artery give branches to the pancreatic angle. The arteries to the right pancreatic lobe arise from the cranial and from the caudal pancreaticoduodenal arteries.The interlobular arteries give origin to the intralobular arteries. The penetration and the distribution of the latter vessels differ in lobules of different shape. The intralobular course may be straight or curved. Branches arise generally at acute angles, forming Y or fork‐like patterns, ending into bundles of arteriole

ISSN:0002-9106    

DOI:10.1002/aja.1001370203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1973

数据来源: WILEY

摘要:

AbstractThe synaptic ultrastructure in the tangential nucleus of the goldfish was studied with the electron microscope. The nucleus consists of cells measuring 30–40 μ in diameter receiving complex innervation from eighth nerve fibers and boutons. Two types of synaptic contacts by the eighth nerve, terminal and en passant, were recognized. Three varieties of the terminal type were described: calyciform, trilobated, and club endings. The three varieties of the terminal type, as well as the synapses en passant, showed gap junctions in their synaptic membrane complex. The morphological characteristics of these endings suggested electrical transmission.The boutons synapsing on the tangential cells were of two types: terminal and en passant. Three varieties of boutons terminaux were described. One of these was classified as a mixed synapse. The morphological characteristics of the synaptic vesicles of the other two varieties suggested that the boutons could be inhibitory or excitato

ISSN:0002-9106    

DOI:10.1002/aja.1001370204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1973

数据来源: WILEY

摘要:

AbstractThe differences in the splenic microvascular system and stroma between Sl/Sldand W/Wvanemic mice were investigated using in vivo microscopic and histochemical methods. Spleens of Sl/Sldanemic mice had increased numbers of sinusoids containing blood flow and an increased concentration of sulfated acid mucopolysaccharide in the splenic stroma when compared to spleens of non‐anemic littermates; in both groups of mice the undifferentiated hemopoietic cells in the red pulp were enveloped with a coating of sulfated acid mucopolysaccharide. In contrast, in the W/Wvanemic mice, the number of sinusoids containing blood flow was one‐half of that seen in non‐anemic littermates. While the concentration of mucopolysaccharides in the splenic stroma of the W/Wvmice and their non‐anemic littermates appeared similar, the W/Wvmice had a deficiency in the number of undifferentiated hemopoietic cells in the red pulp as well as a deficiency in the number of such cells enveloped with a coating of sulfated acid mucopolysaccharide. Transfusion of the W/Wvmice with stem cells from non‐anemic littermates corrected the anemia. Blood flow through the sinusoids was restored to near normal levels, and the number of undifferentiated hemopoietic cells increased in the red pulp; most were enveloped with a coating of sulfated acid mucopolysaccharide.The histochemical results suggest specific defects in the composition of mucopolysaccharides in the hemopoietic microenvironment of Sl/Sldanemic mice and in the cell coatings of undifferentiated hemopoietic cells in W/Wvanemic mice. These results are consistent with our hypothesis that a cell coating of sulfated acid mucopolysaccharide is required for early erythroid differentiation but that a microenvironment which contains excessive concentrations of sulfated acid mucopolysaccharide is not conducive to supporting the later stages of erythroid development. In addition, the results obtained by in vivo microscopy of the microvascular system tend to support our hypothesis that erythropoietin‐sensitive stem cells respond to erythropoietin by producing a substance that is locally

ISSN:0002-9106    

DOI:10.1002/aja.1001370205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1973

数据来源: WILEY

摘要:

AbstractCatecholamines in the early chick embryo (days 2–3) were studied using the Falck‐Hillarp technique. After treating specimens with nor‐epinephrine, specific catecholamine fluorescence was localized in the early neural tube of the youngest embryos (stages 7–9). In older embryos (stages 10–12) exposed to exogenous norepinephrine the fluorescence was seen in both the neural tube and notochord and by stage 13 fluorescence was brighter in the notochord than neural tube. Endogenous notochord catecholamine fluorescence was demonstrable in stages 13 through 17 without exposure to exogenous amines although treatment with a monoamine oxidase inhibitor (nialamide) or norepinephrine intensified the fluorescence. Treatment of embryos with nialamide or an inhibitor of catecholamine synthesis (α‐Methyltyrosine) caused numerous archencephalic anomalies, ventral flexure of the head without lateral rotation, and spina bifida. The results suggest that catecholamines in the early neural tube and notochord may provide the motive force for morphogenetic movements, including closure of the neural folds and torsion o

ISSN:0002-9106    

DOI:10.1002/aja.1001370206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1973

数据来源: WILEY

摘要:

AbstractA method is described which permits the examination of the influences of increasing age and body weight on organ weights. Polynomial multivariate analysis is performed by computer, and the predicted organ weight values permit the construction of three dimensional graphs which show the influence on organ weight of all combinations of age and body weight. The application of the method will allow the physical biology of organisms to be determined with considerable precision over their life span.

ISSN:0002-9106    

DOI:10.1002/aja.1001370207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1973

数据来源: WILEY

摘要:

AbstractEvidence has been accumulating which supports the hypothesis that through phylogenetic evolution, the mammalian pinealocyte has evolved from the pineal photoreceptor‐cell which is characteristic of certain lower vertebrates. In the present study, developing pineal glands in fetal rats and hamsters were studied at light and electron microscopic levels to determine whether or not the ontogenetic development of pineal cells affords clues to their phylogenetic origin. Pineal development in fetal rats occurs during the last eight days of gestation (14–22) and in fetal hamsters, during the last five days of gestation (11–16). The pineal gland exhibits many similarities in the two species as it develops from a tubular evagination of the diencephalic roof into a compact cellular mass. Different cellular types could not be readily distinguished in fetal material from either species. In both animals, as long as lumina persist, cells bordering on these lumina exhibit surface modifications reminiscent of developing photoreceptor‐cells, i.e., an “ellipsoid‐like” apical cytoplasmic bulge which often contains one or two centrioles and bears a ciliary derivative exhibiting a 9 + 0 tubular configuration. As pineal tissue proliferates, the lumina and cilium‐like structures disappear. The findings, when considered with phylogenetic studies, strengthen the hypothesis that the mammalian pineal gland contains cells derived from the photorec

ISSN:0002-9106    

DOI:10.1002/aja.1001370208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1973

数据来源: WILEY

ISSN:0002-9106    

DOI:10.1002/aja.1001370201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1973

数据来源: WILEY