摘要:

AbstractPrevious studies of the turnover of alveolar bone collagenous proteins have devoted little attention to the variable patterns in this process caused by bone remodeling. The present study seeks to document changes resulting from physiologic tooth movements in the incorporation and removal of the3H‐proline label within the interdental septum of alveolar bone. One week following3H‐proline injection, three zones could be distinguished: (1) the appositional band, (2) new bone, and (3) old bone. Radioautography demonstrated that formation of new bone on the distal wall of the septum entrapped fibers of the periodontal ligament to create Sharpey's fibers. At the alveolar crest, new bone entrapped transseptal fibers to form transalveolar Sharpey's fibers. Grain counts were made within each area and over the total septum and were compared statistically. The data strongly suggested regional variations in protein remodeling. Counts from old and new bone were significantly different from the total septum or the appositional band (P<.001). Regression lines were drawn to represent incorporation and removal of the isotope; slopes were calculated and compared statistically. The rate of incorporation and removal was significantly greater in the appositional band and in the total septum in comparison to old bone (P<.001). The rates of incorporation and removal in the appositional band, old bone, and total septum were significantly different (P<.001). Half‐life of the labeled protein of old bone was 16.78 weeks; in the appositional band, 7.66 weeks; and in the total septum, 7.64 weeks. These data suggest that regional variations in collagen remodeling must be considered in a study of interdental bone and that the total septal grain counts are not indicative of the remodeling in the component

ISSN:0003-276X    

DOI:10.1002/ar.1092160302

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

年代:1986

数据来源: WILEY

摘要:

AbstractPrevious transmission electron microscopic studies have demonstrated glomerular basement membrane (GBM) thickening and mesangial matrix (MM) expansion in chronic stages of diabetes. It is difficult, however, to achieve an appreciation of GBM surface features and distribution of MM in planar views. In the current study, autopsy human renal cortical tissue from patients with end‐stage diabetic nephropathy were minced and rendered acellular with detergents prior to fixation, cryofracture, and preparation for light microscopic (LM), transmission electron microscopic (TEM), and scanning electron microscopic (SEM) observation in an effort to visualize extracellular materials in three dimensions.Our studies demonstrated that although diabetic glomerular changes vary widely within and between individuals, most showed alterations primarily affecting peripheral (epithelial) GBM (with MM increased but diffusely distributed), or they exhibited similar GBM changes but with variable nodular MM expansion leading ultimately to capillary occlusion. Both types showed peripheral GBM thickening and demonstrated external surface irregularities that by SEM appeared as “cauliflower‐like” lobulations. In these glomeruli, GBM lamellation or reduplication was common with internal layers frequently thrown into lumenward projections.Glomeruli with diffusely distributed MM generally showed patent capillary channels with little evidence of occlusion. By TEM, highly compact, epithelial GBMs were clearly distinguishable from the electron‐lucent MM. In these preparations the matrix was concentrated in relatively small discrete masses sometimes covered by a finely fibrillar material, which extended intermittently onto lumenal surfaces of epithelial GBMs.In more advanced stages of MM involvement, glomeruli typically exhibited smooth‐surfaced nodules that were increased at the expense of capillary surface area. By TEM, MM nodules were comprised of a meshwork of very fine (20‐Å) fibrils surrounding a variety of detergent‐resistant structures including collagenous fibrils and non‐collagenous 30‐nm circular fibrils with 16‐nm subunits. By SEM, GBM and MM nodules were not distinguishable and merged to form substantial barriers to capillary blood flow. In those capillary channels remaining patent, inwardly projecting folds and ridges were common GBM features, and frequently thin fenestrated layers, distinctly separate from epithelial GBMs, formed sieve‐like linings for the channels. These three‐dimensional observations provide unique views of the processes leading to diabetic glomerular occlusion and suggest a potential for this technique in the

ISSN:0003-276X    

DOI:10.1002/ar.1092160303

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe effect of progressive, diabetes‐associated adiposity on reproductive tract structure and function was examined in 4‐ to 16‐week‐old C57BL/KsJ, control (+/?) and diabetic (db/db) mice. Uterine and ovarian tissues were analyzed by transmission electron microscopy for ultrastructural changes associated with increased intracellular lipid accumulation. In addition, the same tissues were analyzed for changes in activity of tissue lipoprotein lipase, an enzyme that hydrolyzes lipoprotein‐associated triacylglycerols and supports the cellular uptake and storage of free fatty acids. Between 8 and 16 weeks of age, intracellular lipid deposits increased dramatically in the ovarian granulosa, thecal and stromal cell populations, as well as in the uterine epithelium, of diabetic mice compared to controls. By 16 weeks of age, the lipid deposits essentially occupied the entire cytoplasmic area of both the ovarian and uterine cell types in diabetics. The basal lamina underlying the uterine epithelium was expanded in the diabetics relative to controls, and the hyperglycemic condition induced an observable increase in endometrial intercellular space that was occupied by a hyaline type of ground substance of unknown composition and origin. In association with these structural changes, both ovarian and uterine lipase activities were greatly increased in the db/db mice compared with controls. These data suggest that the structural adiposity and functional decline in reproductive tract condition of the db/db mutants are related to the enhanced cellular lipid deposition observed in this species. These changes in structural and metabolic parameters are related to the reproductive incompetence characteristic of this mur

ISSN:0003-276X    

DOI:10.1002/ar.1092160304

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe manchette is a transient microtubular organelle previously considered to “disappear” prior to formation of the definitive midpiece of the spermatozoon. Goodrowe and Heath (1984) have suggested, however, that in stallions the final disposition of the microtubules of the manchette is into the residual cytoplasm. In the present study, spermiogenesis was examined by transmission electron microscopy of testicular samples from eight cats. Feline spermatids also had a manchette of cylindrical shape, largely located in a cytoplasmic collar peripheral to the presumptive midpiece. The parallel microtubules of the manchette were interconnected by arms. Some of these arms were still present after rupture of the manchette cylinder and movement of the microtubules into the residual cytoplasm. On displacement of the manchette microtubules, mitochondria, spherical in shape and peripherally located, moved centrally to elongate and encircle the flagellum to form the definitive midpi

ISSN:0003-276X    

DOI:10.1002/ar.1092160305

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

年代:1986

数据来源: WILEY

摘要:

AbstractQuantitative morphological data on normal human oxyntic mucosa were obtained from endoscopic biopsies in ten healthy male volunteers. Corpus mucosa was biopsied in the resting state and during maximal acid secretion and then processed for light and electron microscopy. Stereological analyses were carried out on sections comprising the entire thickness of the epithelial layer. About one‐third of the mucosal volume was taken up by lamina propria and 15% by parietal cells. Counts of cells that displayed their nucleus in the sections revealed that an average of 12% of the epithelial cells were parietal cells, 43% were mucous cells, 40% were zymogen cells, and 4% were endocrine cells. Parietal cells displaying two nuclei were twice as large as those with only one nucleus. Six percent of the parietal cell volume was taken up by the nucleus, and 33% of the cytoplasmic volume was occupied by mitochondria. Stimulation of acid secretion resulted in a 76% increase in the secretory surface density; simultaneously there was a slight decrease in the mean size of the parietal cells and an increase in the relative volume of the nucleus. During maximal stimulation of acid the parietal cells from the superficial mucosal layers displayed a 40% larger secretory surface than those from the deeper parts of the mucosa.The data, which will serve as a basis for studies of pathological mucosae, are compared with those obtained in other specie

ISSN:0003-276X    

DOI:10.1002/ar.1092160306

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe structural development of the fetal guinea pig lung is described and quantified morphometrically in this report.At 35 days gestation the lung is in the pseudoglandular phase of growth, by 40 days it is in the canalicular phase, and at 50 days the saccular growth phase has begun. At term (67 days), the fetal guinea pig lung appears mature.From the beginning of the canalicular to the end of the saccular phases, the correlation coefficient between lung volume and gestational age is +.98, between internal surface area and gestational age is +.94 and between total number of saccules and gestational age is +.97. Internal surface area (ISA) correlates closely with lung volume (r = +.99) and the correlation coefficient between total number of saccules and lung volume is +.98. At term, lung volume is 4.22 ml. ISA is 0.5 M2, and total number of saccules is 253 million. Parenchymal growth is achieved by increases in both number and size of airspaces in the canalicular phase, primarily by increases in number during the early saccular phase and largely by increases in airspace size near term.The total length of parenchymal elastic tissue increases from 223 M at 45 days gestation to 5,253 M at term. Elastic tissue fibers first appear in the parenchyma of the fetal guinea pig lung during the canalicular phase, when the rate of saccule formation is high. The quantitative increase in elastic tissue correlates closely with the increase in the total number of saccules from day 45 to day 60 of gestation (r = +.99). The rate of elastic tissue growth increases sharply in the late saccular phase, coinciding with the period of greatest saccular expansion. These data suggest an interdependent relationship between saccular growth, i.e., proliferation and expansion, and the development of lung parenchymal elastic tissue.

ISSN:0003-276X    

DOI:10.1002/ar.1092160307

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

年代:1986

数据来源: WILEY

摘要:

AbstractTriple resin casts were made of the pulmonary arteries, veins, and airways from six dog lungs. The airways were cast at a pressure of 25 cm resin in all six. In the first three, both vessels were cast at a pressure of 30 cm resin, and in the second three, arteries were at 10 cm resin and veins at 5 cm resin. Measurements were made of luminal airway diameters down to 1 mm and of the luminal diameters of the corresponding segments of the vascular trees. The relation of one to the other was shown by calculating the regression lines for the corresponding diameters. Intrapulmonary arteries and veins are of approximately equal diameter when cast at 30 cm resin, while the veins are 20% larger than the arteries when cast at 5 cm and 10 cm of resin, respectively. Both vessel diameters are 75% of bronchial at the higher pressure, while at the lower pressures arteries are 59%, and veins 71% of bronchial. In any individual, vessel diameters are a relatively constant proportion of airway diameter. This constant of proportionality varies considerably between dogs, its value ranging from 0.48 to 1.03. It is concluded that in any individual all three trees have similar diameter ratios—that is, the ratio between mean diameters of branches in successive order

ISSN:0003-276X    

DOI:10.1002/ar.1092160308

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe cyst structures of chick ultimobranchial glands were studied by electron microscopy and immunocytochemistry to characterize the type of intermediate‐sized filaments present in the cells lining cyst lumina. Electron microscopy showed that the majority of the lumen‐bordering cells contained extensive mesh‐works of intermediate‐sized (7–11 nm) filaments, many of which were arranged in bundles. Apical regions of C cells directly bordering on cyst lumina were also filled with thinner (5–6 nm) filaments. Immunoperoxidase staining showed that the majority of cyst epithelial cells were stained intensely with anti‐keratin antiserum, but not with anti‐neurofilament antiserum, which is a specific marker for neuronal differentiation. The cyst epithelium also showed moderate‐to‐weak immunoreactivity for actin. Subsequently, the differentiation and maturation of cyst structures related to intermediate filament expression wore studied. In 18‐day‐old chick embryos, keratin immunoreactivity began to appear in the cell clusters destined to form cysts and in the primordial cysts with small cavities. At this time, fine networks of intermediate filaments were already detected in the cells lining the cystic cavities. At 1 day after hatching, the cysts became a consistent feature of ultimobranchial glands. Intermediate filaments associated in bundles were observed, and the intensity of immunostaining for keratins increased. Thereafter, with progressive enlargement of cysts, numbers of intermediate filaments and intensity of keratin immunoreactivity gradually increased with age. Thus, the data indicate that in cyst epithelium keratin filaments are highly organized and may confer the structural strength necessary for c

ISSN:0003-276X    

DOI:10.1002/ar.1092160309

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

年代:1986

数据来源: WILEY

摘要:

AbstractWe have studied changes in myoepithelial cell size and shape during different stages of mouse mammary gland differentiation by using the fluorescent probe for actin NBD‐phallacidin. Pieces of mammary tissue were fixed, mounted on slides, permeabilized with cold acetone (−20°C), and then treated with nitrobenzoxadiazole‐phallacidin. Myoepithelial cells lining ducts of glands at all stages of development are spindle‐shaped structures oriented parallel to the long axis of the duct at the base of the luminal epithelium. In virgin animals, myoepithelial cells also occur as linear tracts oriented parallel to the long axis of small projections along the sides of ducts and terminal end buds. In early pregnancy, small stellate‐shaped cells begin to appear around presumptive secretory units. By late pregnancy, larger star‐shaped units of intense fluorescence appear at the base of alveoli. During lactation, both cell bodies and cell processes further enlarge as these interlacing stellate‐shaped cells encompass the expanded alveoli. In regressing glands, cell size decreases and the processes appear to retract. Although alveoli are virtually absent in the multipartate resting gland, myoepithelial cells remain around lateral buds of ducts. These myoepithelial cells have two distinct shapes: (1) small star‐shaped cells capping the buds and (2) spindle‐shaped cells oriented parallel to the long axis of the buds. A comparison of myoepithelial cell shape in virgin mice and nulliparous women indicates a more developed cell in the human gland at this stage of development. Intact segments of mammary gland combined with NBD‐phallacidin as a probe for actin provide an ideal system for future studies of the control of myoepithelial cell size and shape and their influen

ISSN:0003-276X    

DOI:10.1002/ar.1092160310

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

年代:1986

数据来源: WILEY

摘要:

AbstractThis study utilized scanning electron microscopy (SEM) techniques to observe primary cultures of stromal‐vascular (SV) cells derived from postnatal rat inguinal adipose tissue. Cells were grown on collagen‐coated, fibronectin‐coated, or uncoated glass coverslips. Coverslips were normally fixed in glutaraldehyde, osmium tetroxide, dehydrated, and critical‐point‐dried. Other coverslips were frozen in isopentane (cooled in LN2) and dried or fixed in Baker's formalin for demonstration of inosine diphosphatase (IDPase) by X‐ray microprobe analysis (XRMA). Adipocyte morphologies were similar on all substrates. At 2 days of culture, actin cables were detected extending from developing adipocytes. No difference in actin cable structure, cellular shape, or lipid accumulation was observed among the different substrates. Some stromal cells did not accumulate lipid but proliferated into a multilayer by 9 days in culture. Inosine diphosphatase was detected in the Golgi apparatus of developing adipocytes utilizing the technique of XRMA. This study demonstrates the potential for using SEM and XRMA techniques to define morphological features and cytochemical markers of adipocytes in vitro and the response of primary cultured rat SV cells to other attachment

ISSN:0003-276X    

DOI:10.1002/ar.1092160311

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

年代:1986

数据来源: WILEY