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  • 1
    Electronic Resource
    Electronic Resource
    Morphology of the compound eye of the giant deep-sea isopod Bathynomus giganteus (1986)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 189 (1986), S. 145-156 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The structural organization of the compound eye of the largest known isopod, Bathynomus giganteus, is described from four specimens maintained in the laboratory for as long as two months. Living specimens have not previously been available for study. The two triangular compounds eyes measure about 18 mm on the dorsal edge and are separated by an interocular distance of 25 mm. They face forward and slightly downward and may have significant overlap in visual fields. Each eye contains about 3,500 ommatidia in animals of body lengths from 22.5 cm to 37.5 cm. The packing of ommatidia is not uniform across the retina, but is nearly hexagonal in the dorsal central region and nearly square in the ventral and lateral periphery.The dioptric elements in each ommatidium consist of a laminar cornea, which is flat externally and convex internally, and a bipartite crystalline cone. Sometimes seven and sometimes eight retinular cells closely appose the proximal tip of the cone and bear the microvilli of the rhabdom. Proximal to the rhabdom the retinular cells form thin pillars near the periphery of the ommatidium, and the central portion along the optic axis at this level is occupied by interstitial cells that contain massive arrays of clear vesicles thought to serve as reflective elements. The arhabdomeral segments of the retinular cells and the interstitial cells rest on a basement membrane. Within each ommatidium the basement membrane has two extensions with cylindrical cores and thin sheets of dense material and collagen-like filaments. These sheets occupy spaces between adjacent interstitial cells up to the level of the rhabdomeral segments of the retinular cells. Arrays of pigment cells with relatively weak light-screening properties separate adjacent ommatidia.Animals were fixed both in light within a week of being brought from depth into daylight, and after 2 months of maintenance in constant darkness following such daylight exposure. In both cases, microvilli of the rhabdom were severely disrupted and the retinular cytoplasm contained numerous multivesicular bodies. Exposure to natural daylight appears to cause irreversible structural damage to the photoreceptors of these animals.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051890205
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  • 2
    Electronic Resource
    Electronic Resource
    Angiogenesis in the developing corpus luteum of pregnant rats: A stereologic and autoradiographic study (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 222 (1988), S. 18-25 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Within the adult mammalian ovary, angiogenesis is associated with development of the corpus luteum (CL). In this study, developing luteal tissue was examined to determine whether its vascularization involves endothelial cell replication and to what extent this proliferation contributes to forming new capillaries. Five rats each at 12, 24, 36, 48, 60, 72, 84, and 96 hr of gestation were given a subcutaneous injection of tritiated thymidine (specific activity 5 Ci/M; 1 uCi/g body weight). One hour later they were anesthetised with sodium pentobarbitone, and the left ovary was processed for light microscopy. Sections were cut through each ovary until three newly formed CL were recognized; a 1-μ section was taken from the maximum diameter of each CL and processed for autoradiographic demonstration of thymidine labeling in endothelial cell nuclei. The same sections were also examined with stereological techniques to quantitate growth of the vascular compartment. The results show that 36.1 ± 5.7% of endothelial cells of invading capillary sprouts divide within 12 hr of ovulation; at 24 hr, 29.0 ± 2.8% are dividing. Within 12 hr after ovulation, blood vessels occupied 5.9 ± 1.4% of the peripheral space of the ruptured follicle but only 1.6 ± 0.5% in the center. However, by 36 hr these respective values were 9.3 ± 1.6% and 8.4 ± 1.9% A further peak in endothelial-cell replication (31.2 ± 5.4%), early on the 3rd day of gestation, corresponded to the very extensive anastomoses within the capillary bed established between this time (13.6% vascularity) and late on the 4th day (about 23%). We conclude that replication of endothelial cells from capillary sprouts accounts for substantial angiogenesis in the developing CL. Labeling in endothelium of the developing CL and the capsule surrounding the CL were greater than in CL of previous cycles and vessels within the ovarian stroma. This finding supports the view that there may be some local control of endothelial-cell replication.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092220105
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  • 3
    Electronic Resource
    Electronic Resource
    Ultrastructural changes of rat blastocysts induced by estrogen during delayed implantation (1974)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 179 (1974), S. 253-271 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Ultrastructural changes of rat blastocysts during delayed implantation were studied 16, 20, 24 or 30 hours after estrogen was given to induce implantation.In the inner cell mass the presence of long cytoplasmic processes penetrating deeply into the neighboring inner cell mass cells is seen at 16 hours. Most cells also show an increased number of ribosomes, polyribosomes and granular endoplasmic reticulum.The trophoblast is featured by the formation of large amounts of glycogen and many inclusion bodies. Glycogen granules appear first in some abembryonic trophoblast cells at 16 hours, and spread to the embryonic pole at 24 hours. New inclusion bodies appear sequentially: multivesicular bodies at 20 hours, multigranular bodies at 24 hours and lamellar bodies at 30 hours. The functions of these inclusion bodies remain to be studied.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091790208
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  • 4
    Electronic Resource
    Electronic Resource
    The visual cells of the chicken as revealed by phase contrast microscopyThis investigation was supported, in part, by research grant AM 06705 from the National Institutes of Health, and, in part, by a Fight for Sight Grant-in-Aid of the National Council to Combat Blindness, Inc., New York, New York. (1966)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 118 (1966), S. 723-734 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Phase microscopic investigations of Kolmer-fixed, depigmented sections of the adult chicken retina have provided photomicrographic evidence of the existence of three different photoreceptors: single rods, single cones, and double cones. The rod extends the entire thickness of the visual cell layer and is characterized by a uniformly thick outer segment and a hyperboloid-containing inner segment which is devoid of an oil droplet. The single cone is the shortest element; it contains a red oil droplet. The double cone consists of two unequal members, a tall, slender chief cone and a broad accessory cone. The chief component contains a large yellow oil droplet, whereas the accessory cone houses a small, oval, yellowish-green droplet and a characteristically large, oval paraboloid. The rod hyperboloid and the accessory cone paraboloid contain glycogen. No colorless droplets have been observed. Owing to the close association between oil droplet color and cone type, three colored layers of oil droplets are formed within the thickness of the retina: a proximal row of red droplets (the short, single cones), an intermediate layer of yellowish-green droplets (the accessory cones), and a distal row of yellow droplets (the tall chief cones).
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001180303
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  • 5
    Electronic Resource
    Electronic Resource
    Structural and histochemical aspects of epidermis development of fetal porcine skin (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 176 (1986), S. 207-219 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Epidermal development of fetal porcine skin was studied in fetuses from 41 days of gestation until birth with scanning and electron microscopy techniques as well as histochemical methods, including immunohistochemistry. The porcine fetus develops a relatively thick and solid multilayered cover of epidermal cells, which is not lost before birth. It consists of tightly packed cells of the periderm and the stratum intermedium. The periderm cells are totally filled with filamentous proteins; in the intermediate cells, the filamentous proteins are concentrated in the cell periphery, forming a thick marginal zone. Immunohistochemically, the cytofilaments could be identified as cytokeratins of lower and higher molecular weights. The first thin stratum corneum lamellae are formed below the stratum intermedium at about 80-85 days of gestation.
    Additional Material: 35 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001760209
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  • 6
    Electronic Resource
    Electronic Resource
    Quantitative ultrastructural characteristics relating to transport between luteal cell cytoplasm and blood in the corpus luteum of the pregnant rat (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 172 (1985), S. 87-99 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The synthesis and secretion of progesterone by the corpus luteum (CL) may be limited or controlled by transport mechanisms operating between circulating blood and luteal cell cytoplasm. To examine this possibility, the structural features involved in transport, including membrane surface areas and diffusion distances, were quantitated in the CL of 16-day pregnant rats. One ovary from each of eight rats was fixed by perfusion via a cannula inserted into the parametrial artery, and two CL from each ovary were processed for electron microscopy and examined with standard morphometric techniques. For comparison, one CL from each of a further eight ovaries was diced into small cubes, fixed by immersion, and analyzed similarly. In perfusion-fixed CL, there was a substantial volume of vascular space (20% of the total) and interstitial space (5%) and an extensive surface area of capillaries (441 mm2 per CL). The luteal-cell membrane had numerous projections which increased its surface area by a factor of 3.08. Almost 60% of the luteal-cell surface directly faced a capillary, and a further 37% faced interstitial space which probably extended to a capillary surface. Only 3% was in direct contact with a neighboring luteal cell. Despite the extensive interstitial space the harmonic mean thickness, an estimate of likely effective diffusion distance between luteal cell cytoplasm and blood, was only 0.42 μm. This was less than half of the calculated arithmetic mean thickness owing to the presence of surface projections and an uneven capillary endothelium. Results from immersion-fixed CL were qualitatively similar; but the proportion of interstitial space was only 59% of that in perfusion-fixed CL, and the contribution of surface projections to the total area of luteal-cell membranes was significantly reduced. Collectively, these results suggest that membranes and spaces between blood and luteal-cell cytoplasm are structured so as to minimize transport distances.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001720107
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  • 7
    Electronic Resource
    Electronic Resource
    Primary olfactory projections and the nervus terminalis in the African lungfish: Implications for the phylogeny of cranial nerves (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 182 (1988), S. 325-334 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Primary olfactory and central projections of the nervus terminalis were investigated by injections of horseradish peroxidase into the olfactory epithelium in the African lungfish. In addition, gonadotropin-releasing hormone (GnRH) immunoreactivity of the nervus terminalis system was investigated. The primary olfactory projections are restricted to the olfactory bulb located at the rostral pole of the telencephalon; they do not extend into caudal parts of the telencephalon. A vomeronasal nerve and an accessory olfactory bulb could not be identified. The nervus terminalis courses through the dorsomedial telencephalon. Major targets include the nucleus of the anterior commissure and the nucleus praeopticus pars superior. Some fibers cross to the contralateral side. A few fibers reach the diencephalon and mesencephalon. No label is present in the “posterior root of the nervus terminalis” (=“Pinkus's nerve” or “nervus praeopticus”). GnRH immunoreactivity is lacking in the “anterior root of the nervus terminalis”, whereas it is abundant in nervus praeopticus (Pinkus's nerve). These findings may suggest that the nervus terminalis system originally consisted of two distinct cranial nerves, which have fused-in evolution-in most vertebrates. Theories of cranial nerve phylogeny are discussed in the light of the assumed “binerval origin” of the nervus terminalis system.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001820404
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  • 8
    Electronic Resource
    Electronic Resource
    Expression of von Willebrand factor in porcine vessels: Heterogeneity at the level of von Willebrand factor mRNA (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 138 (1989), S. 305-310 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The expression of the von Willebrand factor (vWF) gene by cultured endothelial cells from the porcine pulmonary artery, aorta, and lung was compared at the levels of messenger (m)RNA and antigen. Steady-state levels of vWF mRNA were determined by dot-blot analysis using a partial human vWF cDNA as the hybridization probe; vWF mRNA from cultured aortic endothelial cells, and vWF antigen secreted into the culture supernatants were barely detectable. In contrast, vWF mRNA and antigen from the pulmonary artery endothelial cells were approximately eight to nine times that demonstrated by aortic cells. Levels of vWF mRNA and antigen in cultured lung cells were intermediate of those found in the pulmonary artery and aorta and correlated with the estimated number of cells demonstrated to be of endothelial origin in the mixed cell populations grown from the lung. Differences between the levels of vWF mRNA found in cultured cells from the pulmonary artery and those found in the aorta were maintained in cells processed directly from these vessels. Correlation between the levels of vWF mRNA and antigen in endothelial cells from different vessels of the pig suggests that the differential control of vWF synthesis is at the level of transcription. Furthermore, maintenance in cultured cells of the difference in transcription rates that were observed in vivo suggests that vWF gene expression is not exclusively regulated through environmental factors.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041380212
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