ISSN:0002-9106    

DOI:10.1002/aja.1001340102

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

年代:1972

数据来源: WILEY

摘要:

AbstractAlbino rats were exposed to fluorescent illumination for four to six months at an intensity which would not cause photocoagulation of the retina. Electron and light microscopic studies indicated that the retinas of these animals were irreversibly damaged and that the degeneration was specifically localized to the photoreceptor cells. Photoreceptors were not found in any of these retinas. Prolonged exposure to low intensity, visible light had no apparent effect on the bipolar neurons and ganglion cells or on their interconnections in the inner plexiform layer. Pigment epithelial cells survived the exposure and were unchanged except for extreme compaction of the apical villous processes in the retinal zone where the photoreceptors were located prior to their destruction. In some degenerated retinas the bipolar neurons were displaced along blood vessels extending from the inner ganglion cell layer to the outer retinal layers. Some of these blood vessels apparently formed anastomoses between the central retinal circulation and the choriocapillaries. The outer Müller cell processes, which contained numerous lamellated and tubular structures, expanded to cover the area adjacent to the pigment epithelium and to form an outer limiting membrane, which was displaced in position in comparison with a normal retina

ISSN:0002-9106    

DOI:10.1002/aja.1001340103

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

年代:1972

数据来源: WILEY

摘要:

AbstractA specific anti‐collagen antiserum was prepared in rabbits using as antigen a rat tail collagen preparation free of serum protein reactants. This antiserum reacted with several forms of isolated collagen and with rat urine, but not with rat serum. It was coupled to fluorescein and used to label sites of collagen in frozen and dried cryostat sections of rat tissues. The indirect method, with uncoupled serum, was also used routinely.Tubular and glomerular basement membranes, Bowman's capsule, basement membrane of skin and lung, reticular fibers of spleen and the connective tissue framework of muscle were strongly stained, as was also new bone on trabecular borders and around osteocytes.The supporting fibers of normal hyaline cartilage, calcified bone, most tendons and the deeper fibers of skin were less stained or unstained under identical conditions and are presumably masked or blockedin situ.Cytoplasm or cytoplasmic processes in some fibroblasts of skin and tendon, cytoplasm of osteocytes and some cartilage cells in elastic cartilage were stained.Reaction and masking in fibers are presumably related to the modes of collagen linkage both within the fiber and externally with the ground substance matrix. Activity could be elicited in tendon by a brief heating at 60°C sufficiently to abolish the collagen birefringence. These collagen linkages are believed to be of importance in determining its behavior in overall processes of tissue disaggregati

ISSN:0002-9106    

DOI:10.1002/aja.1001340104

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

年代:1972

数据来源: WILEY

摘要:

AbstractCapillaries in the area postrema and other brain regions at the level of the obex were examined in Japanese sharks under the electron microscope with or without intravascular injection of horse‐radish peroxidase and histochemical incubation. The postremal capillaries were characterized by a relatively wide perivascular space filled with connective tissue elements including fine fibrils about 100 Å in diameter, and by endothelial fenestration; however, the space and fenestration were apparently less extensive than in rats and cats (Hashimoto, '66; Rivera‐Pomar, '66; Hashimoto and Hama, '68). In other brain regions, the capillary endothelium showed peroxidase‐filled intracellular channels that connected the luminal surface with the basement membrane soon after peroxidase injection. Many of the adjoining endothelial cells were linked by tight junctions. Perivascular astrocytic processes had long, tight contacts of about 125 Å in overall thickness. Discussion was focused on a possible endothelial route for passage of so‐called barrier‐free substances in the central nervous system of higher

ISSN:0002-9106    

DOI:10.1002/aja.1001340105

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

年代:1972

数据来源: WILEY

摘要:

AbstractA diet low in K and Na given to postweaning rats of the Berkeley S1strain led in two experiments to a greater than normal relative weight of the choroid plexus of ventricle IV (= C.P. IV) to weight of the whole brain in both sexes. This effect did not occur in the choroid plexuses of ventricles I + II (= C.P. I + II) and III (= C.P. III), which were lower than normal in absolute weights and unchanged in ratios with whole brain weights after the low K and Na diet. Quantitative microscopic tissue analyses of the choroid plexuses following one of the experiments failed to demonstrate significant differences in relative tissue composition or cellular structure after this diet. Other evidence, and data on normal postnatal growth of choroid plexuses, suggests that the unequal apparent responses of the different choroid plexus regions to the diet are related to differences in their durations and rates of growth after weaning rather than to a necessarily specific cellular response in the choroid plexus of ventricle IV to internal consequences of dietary restriction in K and Na.

ISSN:0002-9106    

DOI:10.1002/aja.1001340106

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

年代:1972

数据来源: WILEY

摘要:

AbstractThe sperm storage receptacles in the oviduct of the garter snake,Thamnophis sirtalis, were studied using histological, histochemical, and electron microscopic techniques. The receptacles are located in the posterior infundibulum and are readily distinguished from other structures within the oviduct. The luminal epithelium consists of secretory cells and ciliated cells. The latter cell type also lines the ducts leading to the receptacles. The distribution of lipids, carbohydrates, and several enzymes (succinic dehydrogenase, acid and alkaline phosphatases, nonspecific esterase, lipase, sorbitol dehydrogenase) in the infundibulum is described.At the electron microscopic level sperm heads are seen to be closely associated with the surface of receptacle cells, often indenting the luminal plasma membrane. The possibility of a “Sertoli cell‐like” relationship is discussed. Formation of cytoplasmic vacuoles in receptacle cells is temporally associated with ovulation and may be part of a mechanism for sperm release from receptacle cells. No contractile elements were observed immediately around the receptacles.Evidence is presented which suggests that free fructose and glucose are produced by the oviduct, possibly to be utilized for sperm metabolism at the time of ovulation and sperm re

ISSN:0002-9106    

DOI:10.1002/aja.1001340107

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

年代:1972

数据来源: WILEY

摘要:

AbstractFemale Sprague‐Dawley rats were used to study effects of lithium carbonate on the ultrastructure of the rat kidney. Experimental rats received daily intraperitoneal injections of lithium carbonate in dosages of 10, 30 or 100 mg/kg/day. These animals were killed on day 12 to 60. Control rats were either non‐injected or injected with either sodium chloride or sodium carbonate. Kidneys from control rats showed no abnormal changes. The 10 and 30 mg/kg lithium carbonate dosages caused progressive mitochondrial swelling, dilatation of cisternae of rough endoplasmic reticulum and occasional swelling of apical cytoplasm in tubular cells localized in the distal portion of the nephron. The 100 mg/kg lithium dosage produced damage in all portions of the nephron. However, the most severe damage, consisting of mitochondrial swelling, dilatation of the rough endoplasmic reticulum, apical cytoplasmic rarefaction and liquefaction, karyolysis and karyorrhexis was noted in the distal convoluted tubules and collecting ducts. The present study demonstrated that low dosages of lithium carbonate do affect the structure of the rat kid

ISSN:0002-9106    

DOI:10.1002/aja.1001340108

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

年代:1972

数据来源: WILEY

摘要:

AbstractThe structure of the interstitial tissue of the rat prostate has been studied using the light and electron microscopes in an attempt to determine the role of the fibromuscular stroma in the normal functioning of the gland. Smooth muscle cells and fibroblasts are the most numerous cell types. They are accompanied by macrophages, mast cells, and undifferentiated cells of low electron density. Smooth muscle cells have cytoplasmic protrusions that extend into corresponding depressions in adjacent muscle cells, and, at these points, the intercellular space is narrowed to 150–2000 Å. Smooth muscle cells and fibroblasts are arranged in parallel in septa between adjacent epithelial alveoli and form a sheath around each alveolus. Proceeding peripherally from the epithelium into the interstitial tissue, this sheath is composed of a layer of one or two highly flattened fibroblasts and a parallel layer of smooth muscle cells, followed subsequently by additional layers of fibroblasts and smooth muscle that merge into the remainder of the interstitial tissue. Most of the capillaries have an uninterrupted endothelium, but in some regions endothelial fenestrations are present. Unmyelinated axons contain aggregations of small granular and agranular vesicles. Vesicles are found in axons at distances up to several thousand angstroms from muscle cells and in axons that approach to within 150–200 Å of smooth muscle cells. In some cases an axon lies in a deep depression in the surface of a muscle cell. The type of innervation and variety of intercellular contact between muscle cells is discussed in relation to probable physiological characteristics of the t

ISSN:0002-9106    

DOI:10.1002/aja.1001340109

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

年代:1972

数据来源: WILEY

摘要:

AbstractOvaries of 1 to 12 day‐old mice contain multilaminar follicles connected by tubular formations of granulosal cells. Conjoined follicles appear to be at synchronized stages of maturation. It is probable that the development of these interfollicular connections, which form during fetal stages of ovarian morphogenesis, is related to the presence of intercellular bridges between primordial germ cell

ISSN:0002-9106    

DOI:10.1002/aja.1001340110

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

年代:1972

数据来源: WILEY

ISSN:0002-9106    

DOI:10.1002/aja.1001340101

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

年代:1972

数据来源: WILEY