摘要:

AbstractThe cytoskeleton of the human osteoarthritic synovial lining cell (SLC) consists of an extensive number of vimentin intermediate filaments (IFs) in addition to microfilaments and microtubules. The IFs are especially prevalent in the SLC processes, but are commonly seen in a paranuclear arrangement. Processes, ending in numerous microvilli and blebs, project into the joint space. Scanning electron microscopy (SEM) further reveals the processes that may parallel the synovium surface for a short distance. IFs extend to the termination of such processes. Numerous pinocytotic vesicles and extensive rough endoplasmic reticulum (rER) are characteristic of the type B cells. Lysosomes and long microvilli identify the type A cell. Punctate adherens, gap junctions, and cilia are the cell membrane specializations of the osteoarthritis (OA) synovium. A comparison with synovium from rheumatoid arthritis (RA) patients is made in order to assess the effect of this inflammatory disease on the SLC cytoskeleton, cell type relationship, and cell arrangement. The prominent cytoskeleton appears to play an important role in the architecture of the synovium. Our findings are further presented in the form of a drawing which in some aspects could describe the morphology of the normal synovium.

ISSN:0003-276X    

DOI:10.1002/ar.1092310202

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

年代:1991

数据来源: WILEY

摘要:

AbstractWhen rat ciliary body is processed by high pressure freezing and freeze substitution, numerous membrane‐bound vesicle profiles are seen in the vitreous associated with the pars plana and in the valleys between the ciliary processes. They consist of a homogeneously distributed fine granular matrix and varying numbers of ribosome‐like structures. The mechanism by which these vesicles are secreted appears to follow an apocrine‐type pattern, albeit at the basal cell surface. Matrix material accumulates between the basal plasma membrane of non‐pigmented ciliary epithelial cells and a cortical layer of cytoskeletal components; the blebs thus formed protrude through a discontinuity in the basal lamina and, by a progressive narrowing of the neck region, are eventually pinched off, giving rise to free vesicles.Under conventional aqueous chemical fixation conditions, most of these vesicles are washed away or their contents solubilized and extracted, which accounts for their not having been identified hitherto as genuine morphological structures. They are nonetheless apparent, albeit in reduced numbers and mostly empty. Such vesicles are also observed in tissue processed according to several other chemical fixation techniques, namely, conventional fixation in the presence of the cationic dye ruthenium hexamine trichloride, simultaneous glutaraldehyde/osmium tetroxide fixation, and microwave fixation. In the latter instance, comparable vesicle preservation to that obtained by high pressure freezing/freeze substitution may be achieved if fixation is followed by cryoprotection, plunge freezing, and freeze substitution instead of conventional post‐fixation and dehydration p

ISSN:0003-276X    

DOI:10.1002/ar.1092310203

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe structure, ultrastructure, histochemistry, and immunohistochemistry of the suprapatella have been described in the rat. The suprapatella is a fibrocartilaginous sesamoid within the tendon of quadriceps femoris that articulates with the femoral condyles during flexion of the knee joint and reduces the amount of bending required at the tendon‐bone junction. The cells of the suprapatella were much larger and more numerous than those in the associated tendon and were packed with vimentin‐containing, intermediate filaments. The tendon cells contained far fewer filaments. The cells of both regions contained actin and tubulin. Histochemical and immunohistochemical studies showed that the suprapatellar cells were embedded in a matrix that is rich in chondroitin sulphate, but does not contain keratan or heparan sulphate. The fibrocartilage of the adjacent attachment zone of the quadriceps tendon also contained chondroitin sulphate, but in addition was rich in type II collagen. The structure of the suprapatella was similar to that of the fibrocartilaginous regions of tendons that pass around bony pulleys. However, there were differences in matrix composition that could reflect functional differences between the fibrocartila

ISSN:0003-276X    

DOI:10.1002/ar.1092310204

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe charge barrier within the renal corpuscle of the pronephric kidney of the lamprey,Petromyzon marinus, was investigated at two life cycle intervals using cationized ferritin and polythyleneimine. In the larval renal corpuscle the endothelium of the glomerular capillaries and the laminae rarae externa and interna of the glomerular basement membrane show regularly‐spaced deposits of the tracers. The lamina densa remains unstained. Concmitant with a loss of major processes of the visceral epithelial podocytes and development of an extensive mesangial matrix in late adult life are alterations in the distribution of the anionic sites. The lamina rara interna is no longer a distinct entity and the mesangium contains irregularly‐distributed anionic sites surrounding electron‐dense deposits. The results indicate that the distribution of the anionic sites during adult life most likely affects the ability of the renal corpuscle to act as an efficient filtration device. This charge distribution is consistent with that seen during some renal pathologies of higher verteb

ISSN:0003-276X    

DOI:10.1002/ar.1092310205

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

年代:1991

数据来源: WILEY

摘要:

AbstractThis investigation was designed to study ovarian and hormonal changes in the after treatment with dehydroeplandrosterone (DHEA). We identified a heterogeneous experimental group of animals with respect to ovarian histology: group I, corpora lutea (Cls) + cysts; group II, CLs + no cysts; group III, no CLs + cysts; group IV, no CLs + no cysts. Histological sections of these ovaries showed healthy and atretic follicles in different stages of cytomorphosis and degeneration. The aforementioned histological groups were also heterogeneous according to their hormonal profiles. Serum androgens, estrogens, and prolactin concentrations are significantly increased in DHEA‐treated animals as compared with controls. There was no significant difference in follicle stimulating hormone between the with cysts and rats without cysts after DHEA treatment. After 20 days of DHEA treatment, rats with CLs have very high levels of luteinizing hormone. Luteinizing hormone and prolactin levels are significantly higher in rats with cysts than in rats without cysts after 10 days of DHEA treatment. As has been shwon in this inquiry, androgens and estradiol levels in rats with cysts after DHEA treatment are higher than those in rats without cysts after DHEA treatment. Therefore, this study suggests that the ovarian cystic condition developed after DHEA treatment in rats, is associated with higher levels of circulating androgens, estradiol, and prolacti

ISSN:0003-276X    

DOI:10.1002/ar.1092310206

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

年代:1991

数据来源: WILEY

摘要:

AbstractWe studied in the rat epididymis the presence of membrane‐bounded vesicles in the stereociliar areas of the epithelial cells. The intimate contact between principal cell stereocilia and luminal spermatozoa was also explored.The epididymidis of adult male albino rats were fixed with Mollenhauer's fixative via the thoracic aorta; they were removed and the caput and the cauda were separated and fixed for 4 additional hours at 4°C. After fixation, the samples were processed with routine techniques for transmission and scanning electron microscopy.The study showed membrane‐bounded vesicles in the lumen of the caput and cauda epididymidis. They are present between stereocilia, in the most peripheral regions of the epididymal lumen, and in a stereocilia‐free zone in the apical plasma membrane of the principal cells. The smaller vesicles are located near the apical surface of the latter, and the larger ones are located near the tips of the stereocilia. Their contents are electron lucent in some images and electron dense in others. In several thin sections some of the vesicles are observed to have a stalk. This suggests that the possible mode of production may be an exocytotic process. Some membrane‐bounded vesicles were found to be in contact with the head or the tail of maturating spermatozoa.Moreover, an intimate contact was found to exist in the epididymidis between the plasma membranes of the spermatozoa and the stereocilia.These observations seem to suggest two possible mechanisms for sperm‐epididymal cell relations: 1) release of a secretion product via the membrane‐bounded vesicles and 2) direct contact between stereocilia and

ISSN:0003-276X    

DOI:10.1002/ar.1092310207

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

年代:1991

数据来源: WILEY

摘要:

AbstractA morphometric analysis, based on mathematical evaluations and stereological methods, has been used to study five left neonatal ovaries, removed from full‐term neonates with a 46, XX karyotype free from malformations of the genital apparatus.Each ovary was completely cut obtaining serial sections and one 1‐μ‐thick section every 1,000 μ was examined. Ovarian length ranged from 9 to 17 mm (mean 13 mm), width from 3.5 to 7 mm (mean 5.7 mm), thickness from 2.5 to 5 mm (mean 4 mm), and volume from 82.23 to 198.3 mm3(mean 125.88 mm3). In the ovarian cortex, primitive cortical tissue accounted for 10‐20% of the total volume, follicles for 10‐25% and interstitium for 35‐45%; 10‐30% of the organ consisted of inner medulla. The total follicle number ranged from 130,000 to 385,000 per ovary, with an average of 266,000 with 95% being represented by primordial follicles. In all ovaries examined follicular growth was still in process, with follicles at different stages

ISSN:0003-276X    

DOI:10.1002/ar.1092310208

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

年代:1991

数据来源: WILEY

摘要:

AbstractA three‐dimensional analysis to evaluate structural changes in cultured cardiac myocytes following adrenergic innervation was performed using stereological techniques formerly limited to cells in tissue and organs. Cell volumes were calculated for two groups of cells at 96 hours in culture: isolated myocytes and myocytes innervated with adrenergic neurons. Relative and absolute volumes of the nucleus, cytoplasm, and cell were quantified by systematically sampling sections throughout the cell and by point count sampling techniques. Volumetric estimates were similarly determined for the mitochondria, sarcomeres, and other cellular components in the cytoplasm. Data were analyzed with ANOVA and randomized block design to control for variation among the cultures. Adrenergic innervation produced a 44% increase in cell volume, X±SEM, (3,344±196 μm3to 4,816±400 μm3,P= 0.007). The absolute volume of mitochondria significantly increased after innervation (521±42 μm3to 744 ± 54 μm3,P<0.01). Absolute sarcomere volume did not change significantly (750 ± 92 μm3to 642 ± 1061 μm3,P= 0.14). Other cellular components, defined as all cytoplasmic components except mitochondria and sarcomeres, significantly increased with innervation (1,739 ± 166 μm3to 3,097 ± 338 μm3,P= 0.02). The relative volume of the nucleus and the cytoplasm in the cell remained unchanged following innervation. However, the relative volume of mitochondria decreased by 6%, the percent of the cytoplasm occupied by the sarcomeres decreased by 44%, and the volume occupied by the other cellular components increased by 22%. These findings support the use of stereological analysis as a means to quantify cell volumes of cultured myocytes. Significant increases in cell size, as well as changes in intracellular composition, accompany in vitro adrenergic innervation in the developi

ISSN:0003-276X    

DOI:10.1002/ar.1092310209

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe distribution of type I collagen, fibronectin, laminin, and heparan sulfate was studied in marrow of rats by indirect immunofluorescence. Most of the type I collagen of marrow is associated with large blood vessels and connective tissue trabeculae, but type I collagen was also localized in a delicate meshwork throughout the marrow and in the basement membrane of the sinusoidal endothelium. Fibronectin is partially co‐distributed with type I collagen, but is much more widely distributed. Sheets or septa of fibronectin‐rich material divide the marrow into small compartments that contain and appear to separate clusters of developing blood cells. These septa may serve as a substrate for anchorage and migration of blood cells. Labeling of laminin was observed in the basement membranes of blood vessels, of fat cells, and of the sinusoidal wall, but only scattered labeling was seen in other extracellular materials. Heparan sulfate proteoglycan was poorly labeled in the extracellular matrix of mar

ISSN:0003-276X    

DOI:10.1002/ar.1092310210

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

年代:1991

数据来源: WILEY

摘要:

AbstractDifferentiation in the mouse embryo begins at the 8‐cell stage when the blastomeres spread against each other in a process called compaction. The spreading behavior of blastomeres on lectin‐coated coverslips mimics that of blastomeres in the embryo, and we have utilized this model system to obtain an en face view of the membrane skeleton in the spreading blastomeres. Embryos were cultured on the coverslips for periods ranging from 20 sec to 6 hr, and the cells were disrupted to expose the cytoplasmic face of the adherent membranes and their associated filaments. The “membrane lawn” preparations were fixed, critical point dried, rotary shadowed, and the replicas examined by transmission electron microscopy.Using this technique we found that the plasmalemma of rounded blastomeres is associated with a lacy 3‐dimensional filamentous meshwork that is transformed into a thin mat of densely woven filaments when the cells flatten. The overall organization of the membrane skeleton is similar in flattening 2‐ and 8‐cell embryos, but there are significant differences in the time required for spreading to take place, in the means whereby the membrane skeletons are reorganized, and in the extent of maximal flattening. The significance of these observations for the compaction process

ISSN:0003-276X    

DOI:10.1002/ar.1092310211

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

年代:1991

数据来源: WILEY