摘要:

AbstractChoroid plexuses from the four cerebral ventricles of mice, rats, guinea‐pigs, rabbits, cats, cows, and monkeys were either sectioned after freeze‐drying or stretched on microscope slides for subsequent exposure to formaldehyde gas to demonstrate fluorescent adrenergic nerves. All plexuses received a substantial amount of noradrenaline‐containing axons which originated in the superior cervical sympathetic ganglia. The nerve terminals enclosed both arterial and venous vessels. Some of the terminals in the tufts of the choroid plexus ran between the base of the epithelial cells and the underlying vascular wall. Thus, there are structural possibilities for a sympathetic innervation of the plexus epithelium, the plexus blood vessels, or

ISSN:0002-9106    

DOI:10.1002/aja.1001390302

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

年代:1974

数据来源: WILEY

摘要:

AbstractThe kidney of the Atlantic hagfish,Myxine glutinosa, consists of large, paired, segmentally arranged renal corpuscles connected to the archinephric ducts by short tubules. The blood supply to the kidneys is arterial in origin; there is no renal portal system. Each renal corpuscle is supplied by one afferent arteriole and drained by several efferent vessels which in turn supply the tubules and archinephric ducts. Irregularly spaced renal veins drain blood from the ducts into the posterior cardinal veins.The capillaries of the multilobed glomeruli are lined by thick endothelial cells which are rarely fenestrated. These are coated by the short pedicels of the podocytes of the visceral layer of Bowman's capsule. The mesangium is well developed between the endothelium and the glomerular basal lamina.The epithelial cells of all regions of the tubules and archinephric ducts are characterized by a brush border, a complex system of lateral interdigitations, and a paucity of basal infoldings. Pits, vesicles, large vacuoles, and single membrane‐limited inclusion bodies (lysosomes?) are abundant in the apical cytoplasm. It is suggested that these cells are specialized for the reabsorption of material

ISSN:0002-9106    

DOI:10.1002/aja.1001390303

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

年代:1974

数据来源: WILEY

摘要:

AbstractDifferences in the ultrastructure of basophils in the bone marrow reflect transition from early to late stages of cell development. Mast cells in the trachea, stomach and duodenum lack such developmental changes, but one cell encountered in mitosis indicates a low rate of replication by apparently mature cells. Mast cells differ from basophils in shape and in the structure, shape, and position of the nucleus. The Golgi complex clearly participates in granulogenesis in early basophils but not in late basophils or mast cells, and in mast cells appears associated with rough coated vesicles and mitochondria. In basophils precursor granules mature into a homogeneous granules population. The more numerous, smaller, rounder, granules of the mast cells differ also in varying widely in structure and not evidencing a clear maturational sequence. Increased density of mast cell granules apparently correlates with decreased size and increased indentation by a lucent focus and with the presence of lucent vacuoles in the cytoplasm. Laminated, crystal‐like foci replacing the thread‐like component in the periphery of some granules appear rigid and resist the indentation deforming the granule elsewhere. Mast cells of the adult differ from those of fetal guinea pigs in lacking the concentric lamination and having more dense granules. Many mast cells reveal several small, dense bodies which apparently constitute a second granule type, and often occupy the lucent indentation of the large gran

ISSN:0002-9106    

DOI:10.1002/aja.1001390304

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

年代:1974

数据来源: WILEY

摘要:

AbstractIntravascular macrophages were found commonly in sections of calf lung capillaries. These cells were large with many pseudopodia of various sizes. The cell membrane was covered with an electron‐opaque coat which remains between adjacent pseudopodial walls and results in structures suggesting “micropinocytosis vermiformis.” The cytoplasm of the macrophage was electron‐lucent and contained endoplasmic reticulum, numerous mitochondria, free ribosomes, Golgi zones, dense bodies and vesicles of many sizes. These macrophages showed phagocytic activity. During erythrophagocytosis, a dense layer initially appeared at the red blood cell periphery. This layer moved toward the center together with the erythrocyte membrane as phagocytosis progressed. Simultaneously, the electron opacity of the red blood cell decreased until the cell was completely dispersed within the macrophage. This erythrophagocytosis occurred relatively seldom. The possibility that intravascular macrophages are the pre‐cursors of alveolar macrophages is

ISSN:0002-9106    

DOI:10.1002/aja.1001390305

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

年代:1974

数据来源: WILEY

摘要:

AbstractMorphological and histochemical studies on the testes of mice with XX sex‐reversal demonstrates several profound differences in the ultracytology and oxidative enzyme activity of Sertoli cells as compared to the normal. Membranous structures, cytoplasmic inclusions, and certain dehydrogenases in Sertoli cells of normal mice are described in relation to a possible role in steroid synthesis. In XX sex‐reversed mice, two types of Sertoli cells are observed in the seminiferous tubules which are devoid of germ cells. One type is the randomly dispersed cells, which reveal the following ultrastructural alterations when compared with the normal cells: large spherical nuclei with prominent nucleoli, reduced smooth endoplasmic reticulum, pleomorphic mitochondria with no apparent cristae, and decreased lipid droplets. The other type is clustered cells which appear similar to immature Sertoli cells. These cells have small nuclei with poorly developed nucleoli, small profiles of rough endoplasmic reticulum, pleomorphic mitochondria, decreased lipid droplets, and an absence of specialized inter‐Sertoli cell junctions.The results of this study suggest that functional and ultrastructural alterations of Sertoli cells in XX sex‐reversed mice may result from degeneration or absence of germinal cells, and that steroidogenesis by Sertoli cells in mice may be associated with the development of germinal cells. It is also suggested that Sertoli cells may secrete a steroid which controls follicle‐stimulating hormone

ISSN:0002-9106    

DOI:10.1002/aja.1001390306

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

年代:1974

数据来源: WILEY

摘要:

AbstractLumbar spinal ganglia, L2,3,4were ablated in four cats to determine the distribution of degenerating lumbar afferents in the urinary bladder. Bladders were collected at 7, 14, 21 and 35 days following ganglionectomy. Six regions of the urinary bladder were sampled bilaterally and examined ultrastructurally in each cat. Overall, 3,033 terminal axons were counted, of which 2.6% were degenerating; of these, 9% had synaptic vesicles and were interpreted as efferent axons of postganglionic neurons with cell bodies in spinal ganglia. Lumbar afferents were most numerous in the trigone region, followed next by the ventral neck region; regions cranial to the ureters had similar small populations of lumbar afferents. A similar distribution pattern was observed for terminal axons containing granular synaptic vesicles. The relative concentration of lumbar innervation caudal to the ureters seems to account for the increased density of terminal axons observed in this region. Lumbar afferents were distributed bilaterally to the bladder and were numerically similar within and outside muscle fascicles. Ultrastructural evidence supports the position that bladder receptors are free nerve endings except for sparse Pacinian corpuscles.

ISSN:0002-9106    

DOI:10.1002/aja.1001390307

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

年代:1974

数据来源: WILEY

摘要:

AbstractScanning electron microscopy, sometimes supplemented with transmission electron microscopy, was used to study the ultrastructural morphology of the extrapulmonary respiratory tract. Material for observation was taken from male rat respiratory tracts which were fixed in situ and critical point‐dried. Goblet cells, brush cells, potential ciliated cells, ciliated cells, cornified vestibule cells and the olfactory mucosa could be distinguished by their characteristic surface morphologies. The distribution of these various cell types throughout the extrapulmonary respiratory tract is described. Transmission electron microscopy of material treated with ruthenium red reveals that a polyanionic surface layer coats all cilia, microvilli and the intervening cell surfaces on all cell types found in the nasal cavities, trachea and extrapulmonary bronch

ISSN:0002-9106    

DOI:10.1002/aja.1001390308

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

年代:1974

数据来源: WILEY

摘要:

AbstractNo significant differences in oxyhemoglobin affinity, or electrophoretic patterns of hemoglobin were found in 18 bull sharks collected in selected regions of Lake Nicaragua, the Rio San Juan, and the Caribbean Sea. The half‐saturation of hemoglobin with oxygen (P50) was 11 and 17 mm Hg at pH 7.4 and 6.8, respectively (25° C, 3% hemoglobin solution, potassium phosphate buffer, 0.3 ionic strength). Electrophoresis resolved the hemoglobin into a minor and a major band. Planimetry of densitometric recordings showed that the major band constituted 54% of the total hemoglobin; the minor band, 46%. On the basis of these hemoglobin studies, no subspeciation of bull sharks in Lake Nicaragua was identified, although marine bull sharks have free access to the lake and have been there, at least, since 1535; the synonymy of Carcharhinus nicaraguensis with C. leucas was confirm

ISSN:0002-9106    

DOI:10.1002/aja.1001390309

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

年代:1974

数据来源: WILEY

摘要:

AbstractThe glycogen concentration in the immature rat uterus was investigated at three‐hour intervals over a 24‐hour period. Control animals received injections of 0.1 ml of oil while 0.06 μg of 17β‐estradiol was administered to experimental rats; the animals were sacrificed 24 hours later. Peak concentrations were observed at 9 a.m. for both control and experimental groups. The low value for controls appeared at 12 p.m. and for experimentals at 3 a.m. The difference between low and high points represented a 102% increase for controls and 59% for estradiol‐treated rats. These data show that a circadian rhythm is present in the rat uterus and that the uterus of the immature rat responds differently to estrogen stimulation according to the time of day the hormone

ISSN:0002-9106    

DOI:10.1002/aja.1001390310

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

年代:1974

数据来源: WILEY

摘要:

AbstractThe effect of the pineal on circadian periodicity of plasma corticosterone in rats was studied. Male rats were pinealectomized, blinded, or pinealectomized and blinded, and exposed to a lighting cycle of 12 hr of light and 12 hr of darkness.The diurnal variation in plasma corticosterone in pinealectomized animals was not different from that found in intact controls. Blinded rats did not show normal steroid cyclicity. In contrast, rats that were both blinded and pinealectomized had a diurnal variation similar to that of the controls. The pineal gland, then, appears to contribute to the disturbed plasma corticosterone rhythm found in blinded rats.

ISSN:0002-9106    

DOI:10.1002/aja.1001390311

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

年代:1974

数据来源: WILEY