摘要:

AbstractExplants of human adipose tissue were incubated in Parker's medium 199 and the rates of glucose incorporation into the lipids and release of glycerol determined. Both of these parameters increased in a linear fashion for about seven to eight days. After this period of time there was a decrease in the metabolic rates of explants with a mean cell size larger than about 90‐95 μm. The incorporation of glucose into the lipids was mainly recovered in the glycerol moiety of the triglycerides. Cellular enlargement was associated with an increase in glucose incorporation as well as glycerol release, i.e., an increased turnover of the glyceride‐glycerol. Addition of insulin increased the incorporation of label into the lipids. The stimulatory effect of a single dose of insulin was pronounced for two days and was only slightly discernible after 14 days. Addition of the enzyme inhibitor iodoacetate at a concentration of 10−4M reduced the incorporation of glucose to about 5% of the controls. The method of tissue culture used in the present investigation may be a useful tool for metabolic as well as morphologic studies of human adipose tissuein

ISSN:0003-276X    

DOI:10.1002/ar.1091720401

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

年代:1972

数据来源: WILEY

摘要:

AbstractThe stomach of the suckling echidna is lined by a tall columnar epithelium that is bounded basally by a delicate basement membrane. Adjacent cells are held in close apposition by tight junctions near the apex and by extensive implications of the remaining lateral surfaces. The basal cell surface is smooth and without apparent specialization. The lining epithelium is characterized by an abundance of mitochondria and a relative paucity of other organelles. Scattered argentaffin cells extend between the bases of the gastric lining cells and rest upon the luminal side of the basement membrane.Absorptive cells lining the small intestine of the suckling echidna exhibit in‐vaginations of the apical plasma membrane which branch and anastomose, forming a dense network of tubules in the apical cytoplasm. Adjacent to this network is a series of small vacuoles of varying diameters which come into direct relation with a single, large, supranuclear vacuole. The vacuolar system contains both a fine granular substance and clusters of a flocculent amorphous material thought to be of a proteinaceous nature. The surrounding cytoplasm contains numerous profiles of smooth endoplasmic reticulum, several Golgi systems, and a relative abundance of mitochondria. Clusters of homogeneous droplets are found in the cytoplasm and in the intercellular spac

ISSN:0003-276X    

DOI:10.1002/ar.1091720402

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

年代:1972

数据来源: WILEY

摘要:

AbstractThe fine structural appearance of Z‐disk lattices in vertebrate skeletal “fast” muscle varies depending upon whether osmium or glutaraldehyde has been employed as the primary fixative. Prior investigators have attributed the differences to change in the extent of actin filament overlap within the Z‐disk and/or to rearrangement of Z‐disk filaments.Adult frog and young newt “fast” muscle has been studied under various degrees of stretch, with several different aldehyde and osmium fixation procedures, and after plastic section digestion techniques utilizing Pronase or pepsin. Serial cross sections of Z‐disks were correlated with oriented cross and longitudinal sections. Fixation with collidine‐buffered osmium and veronal acetate‐buffered glutaraldehyde seems to provide the greatest and most distinctly contrasting differences. A consistently arranged phase, the filamentous lattice, can be discerned after either fixation. However, a second phase, termed “Z‐disk matrix,” appears variable, perhaps due to extraction during primary osmium fixation procedures. Glutaraldehyde‐fixed frog muscle Z‐disks display a copious matrix, one which is seldom totally depleted by osmium fixation. In young newt muscle Z‐disks, little matrix is present after glutaraldehyde fixation and none of it remains after primary osmium. In Z‐disks fixed by either method, matrix that is retained appears to be deposited in lattice‐like patterns. It is suggested that these matrix patterns, or their loss, are the basis for the varying images of Z‐disks observed under diferent fixation conditions and that the filamentous lattice is relatively stable. The Z‐disk is more rapidly obliterated by Pronase or pepsin digestion than is any other muscle component, including actin (which appears notably unreactive). The rapid digestion effect is limited to the region postulated to include the matrix phase. Models for the structural interrelationship of filamentous and matrix phases are discus

ISSN:0003-276X    

DOI:10.1002/ar.1091720403

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

年代:1972

数据来源: WILEY

摘要:

AbstractChanges in the ependymal surfaces of the floor of the third ventricle and lateral recess have been studied in male rats by electron microscopy after the intraventricular administration of epinephrine or dopamine. In control rats the floor of the third ventricle has essentially a smooth contour interrupted only by occasional bleb‐like protrusions or microvilli. In the floor of the lateral recess this surface gradually becomes more irregular due to the appearance of increased surface modifications. A further increase in the number of complexly‐folded microvilli, pinocytotic vacuoles and coated vesicles occurs on the epen‐dymal surface of the roof of the lateral recess and adjacent ependyma. These morphological findings are consistent with the concept that the ependymal cells of the lateral recess may serve as important sites for the absorption of materials from the CSF.Increased numbers of bleb‐like protrusions were observed on the ependymal surface of the floor of the third ventricle five minutes after the intraventricular administration of either epinephrine or dopamine. The ependymal surface of the roof of the lateral recess also showed bleb‐like protrusions and a complexly‐folded microvillus border. Fifteen minutes after either the epinephrine or dopa‐mine administration all of the ependymal surfaces studied appeared as in control rats. The increase in bleb‐like protrusions noted in the floor of the third ventricle after the injection of epinephrine or dopamine are suggestive of a secretory process rather than a manifestation of an absorptive function

ISSN:0003-276X    

DOI:10.1002/ar.1091720404

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

年代:1972

数据来源: WILEY

摘要:

AbstractInclusion bodies observed by light microscopy in the superficial epithelial cells of the urinary bladder of the rhesus monkey have been examined by electron microscopy. The inclusions varied from focal aggregates of fibrils in their least differentiated form to mature, paranuclear inclusion bodies 3 × 5 μ in size composed of orderly arranged fibrillar structures. The fibrils comprising the inclusions were indistinguishable from cytoplasmic tonofilaments. The significance of the inclusions remains obscure in the absence of known physiologic alteratio

ISSN:0003-276X    

DOI:10.1002/ar.1091720405

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

年代:1972

数据来源: WILEY

摘要:

AbstractThrough the application of histological and histochemical techniques, this study demonstrates that the ossification process of the mandibular condyle differs basically from that of other endochondral growth sites. In the epiphyseal plate of a typical long bone, the cartilage cells are known to undergo degenerative processes and death. In the mandibular condyle, however, the cartilage cells keep their vitality throughout the cartilage zones. In the lower border of the calcified cartilage, adjacent hypertrophic cartilage cells fuse after the dissolution of the intervening matrix to form multinuclear chondroclasts. These giant cells reveal marked positive reaction to mitochondrial and lysosomal enzymes. It is suggested that these enzymes are active in the resorption process of the calcified cartilage matrix, which is an integral phase of the ossification mechanism of the condylar growth center. It is believed that the mandibular condyle of the mouse demonstrates a specific type of endochondral ossification, in which the hypertrophic chondrocytes are not dying cells, but contribute actively to the process of bone formation.

ISSN:0003-276X    

DOI:10.1002/ar.1091720406

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

年代:1972

数据来源: WILEY

摘要:

AbstractIn Wistar‐Fürth rats given vinblastine sulfate intravenously, an abnormality of the glomerular capillary wall was observed. Electron micrographs of renal corpuscles of treated animals revealed sites where the glomerular endo‐thelium had separated from the glomerular basement membrane. The resultant subendothelial space contained a flocculent material similar in appearance to the blood plasma present within the capillary lumen. Endothelial detachment sites were observed near the mesangial region, as well as in parts of the capillary loops distant from the mesangium.Vinblastine treatment also resulted in a disappearance of microtubules from the cytoplasm of endothelial cells and in an appearance of paracrystalline inclusions which were similar in fine structure to those reported in previous studies usingVincaalkaloids. Although these intracytoplasmic paracrystals were common in the glomerular endothelium of treated animals, they were rarely seen at sites of endothelial detachment. The way in which vinblastine treatment elicits endothelial detachment is not k

ISSN:0003-276X    

DOI:10.1002/ar.1091720407

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

年代:1972

数据来源: WILEY

摘要:

AbstractIn the adult goldfish,Carassius auratus(a stomachless freshwater teleost), there is a striking proximal‐to‐distal gradient in the microscopic appearance of the intestine. This gradient is correlated, moreover, with differences in the site of absorption of lipid and protein. The proximal regions (intestinal bulb and anterior intestine) have a greater surface area, manifested by elongated mucosal ridges in which the epithelial cells have regularly arranged closely spaced microvilli. The distal region (posterior intestine) has less overall surface area, but the epithelium exhibits the typical ultrastructural features of pinocytosis, namely extensive invagination of the luminal surface membrane and massive accumulation of vesicles and vacuoles in the apical cytoplasm. In addition, a conspicuous PAS‐positive supranuclear “body” is visible with the light microscope. Administered triglyceride is absorbed exclusively by the epithelium of the anterior regions, where presumably, it must be hydrolyzed prior to uptake. Protein (horseradish peroxidase), on the other hand, is absorbed primarily in the most distal region, where the epithelium appears to be equipped for the uptake of large intact molecules. These regional differences are discussed in relation to comparable differences in the mammalian intestine, especially during de

ISSN:0003-276X    

DOI:10.1002/ar.1091720408

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

年代:1972

数据来源: WILEY

摘要:

AbstractThis investigation was designed to provide the structural basis for snout‐mandibular movement of insectivores. Muscle spindle distribution in the snout musculature of six Japanese shrew‐moles was examined in serial cross sections stained with hematoxylin‐eosin and azan.Zygomaticus major, Levator labii superioris and Zygomaticus minor contain about 120 muscle spindles but Levator alae nasi superioris and inferioris have no spindles. The spindles are concentrated within the lower half of the musculature. The average of the spindle area of one muscle measured was about 0.1 mm2and the extent the spindles were observed was 11 mm. The ratio of the spindle area to the muscle area was a maximum of 25% in the posterior one‐third of the belly, 10% in the middle and 1% in the anterior.Since the facial muscles are considered either to be devoid of spindles or few in number, it is of considerable interest that the snout musculature is supplied by abundant muscle spindles. It also suggests that the delicate movements of the snout muscle might be under minute control of the proprioceptive me

ISSN:0003-276X    

DOI:10.1002/ar.1091720409

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

年代:1972

数据来源: WILEY