摘要:

AbstractThe fine structure of the extracellular matrix was examined in the Engelbreth‐Holm‐Swarm (EHS) tumor of the mouse. The matrix is composed of layers parallel to the surface of the associated cells; the layers are poorly defined close to the cells (proximal region) but quite distinct at a distance from the cells (distal region). In theproximal regionof the matrix, the indistinct layers are composed of three types of structures: (1) a network of 3‐to 8‐nm‐thick „cords”︁ makes up the bulk of the tissue. (2) Within the network are scattered few 7‐ to 10‐nm‐wide, hollow rods of indefinite length, referred to as „basotubules”︁; their cross section has a dense, more‐or‐less‐circular or pentagonal wall and a light lumen containing a spherule. In addition, many plae profiles similar to these cross sections are present; they are interpreted as small, independent structures. (3) Minute structures composed of two parallel, 3.5‐nm rodlets are referred to as „double pegs.”︁ In thedistal regionof the matrix, the distinct layers include the same three types of structures, but basotubules are numerous and prominent; in each layer, they are arranged in picket‐fence fashion along two parallel planes. Cords are packed between them. Double pegs are scattered throughout the clear interlayer spaces.Inasmuch as cord network, basotubules, and double pegs are present in the two regions of the tumor matrix, both regions resemble basement membrane. To explain the contrast between the paucity of basotubules in the proximal region and their abundance in the distal region, it is proposed that, as the production of newer matrix by the cells causes the older matrix to be displaced distally, the independent structures seen as pale profiles in the proximal

ISSN:0002-9106    

DOI:10.1002/aja.1001740402

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe presence of six substances—laminin, type IV collagen, heparan sulfate proteoglycan, ontactin, fibronectin, and the amyloid P component—was investigated immunohistochemically in the matrix of the Engelbreth‐Holm‐Swarm (EHS) mouse tumor after it had been fixed in formaldehyde (with or without a brief preliminary glutaraldehyde fixation), embedded in Lowicryl K4M, and sectioned for processing through the protein A‐gold sequence. Enumeration of the number of gold particles per sequare micrometer of matrix sections demonstrated that the six substances were present in distinct amounts. The results for each substance were fairly consistent throughout the matrix in three experiments. Furthermore, the available evidence indicated that, with the exception of the amyloid P component, the substances were associated with the cord network of the tumor matrix. Finally, the use of a reconstituted basement membrane containing known amounts of laminin, type IV collagen, and heparan sulfate proteoglycan as a standard, led to the conclusion that, in the tumor matrix, the relative content of laminin to type IV collagen to the proteoglycan was in a ratio of 1:0.6:0.03, suggesting molar ratios of approximately 1:1:0.2, res

ISSN:0002-9106    

DOI:10.1002/aja.1001740403

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

年代:1985

数据来源: WILEY

摘要:

AbstractImmunohistochemical methods were applied to the ultrastructural localization of the amyloid P component in the EHS tumor matrix. First, the preembedding approach was used by exposing frozen sections of tumor to antiserum against the mouse amyloid P component followed by the peroxidaseantiperoxidase sequence. Second, using the postembedding approach, Lowicryl K4M sections of the tumor were exposed to antiserum against the amyloid P component and subjected to the protein A‐gold procedure. In both cases, the immunostaining was restricted to structures which appeared in longitudinal section as fairly straight rods and in cross section as 7‐ to 10‐nm pentagonal or roughly circular profiles outlining a lumen with a central dot. Since these features are characteristic of basotubules, it is concluded that the basotubules of the tumor matrix possess the antigenicity of the amyloid P component and presumably contain this substance itself. Similar experiments carried out on the thick basement membrane known as Reichert's membrane demonstrated that its basotubules also possessed amyloid P‐component antigenicity. It is likely, therefore, that the amyloid P component is a constituent of baso

ISSN:0002-9106    

DOI:10.1002/aja.1001740404

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

年代:1985

数据来源: WILEY

摘要:

AbstractThis report describes a study designed to test factors that may affect the efficiency and specificity of stains for gonadotropins. These include chemical or freeze‐fixation and dehydration, heat polymerization of the plastic embedding compound, dehydration in organic solvents, and etching. Specifically, postembedding stains for LH or FSH subunits were applied to 1‐μm sections of (1) Araldite‐embedded pituitaries that were either chemically fixed and dehydrated or freeze‐fixed and freeze‐dried; (2) Aldehyde‐fixed pituitaries that were dehydrated in water‐soluble glycol methacrylate (GMA) and embedded in GMA at 4°C; and (3) p‐formaldehyde‐fixed pituitaries that were embedded in paraffin. A fourth group of pituitaries was dispersed and grown in monolayers for 1–3 days. These were stained following glutaraldehyde fixation. The optimal dilution of the primary antisera varied with the protocol; however, the percentage of cells staining for beta subunits did not change. In contrast, postembedding stains showed that alpha subunit reactivity is masked or destroyed in pituitaries that are fixed in glutaraldehyde and embedded in Araldite. Alpha chain reactivity was detected (in 14% of cells) either after freeze‐fixation and freeze‐drying followed by Araldite embedding, or after 4% paraformaldehyde fixation and GMA embedding (in 17% of cells). Staining in paraffin‐embedded pituitaries was seen in only 10% of the cells. Preembedding stains for alpha chains were strikingly sensitive, however, and immunoreactivity was seen in 18–26% of the population of monolayer cells. Thus, whereas the percentages of cells staining for beta subunits do not change following the use of most of the fixation and embedding protocols, alpha chain reactivity is destroyed by all but the mildest. These findings show that one can control or improve the specificity of the stains for LH and FSH by th

ISSN:0002-9106    

DOI:10.1002/aja.1001740405

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

年代:1985

数据来源: WILEY

摘要:

AbstractIn this study, lectin‐binding techniques are applied to growthplate cartilage to analyze the intracellular localization of lectin‐binding glycoconjugates of chondrocytesin situ. The binding of ten fluorescein‐conjugated lectins is analyzed on 1‐μm‐thick Epon‐embedded, nondecalcified sections of growth plates from Yucatan swine. Comparisons are made to intracellular binding in chondrocytes of tracheal, articular, and auricular cartilage. Ear epithelium, tracheal epithelium, and kidney are used as positive control tissues for the specificity of lectin binding. Only the mannose‐binding lectins had affinity for the RER and nuclear envelope. Eight lectins reacted within the Golgi complex with characteristic patterns which ranged from localized fine linear strands to extensive vesicular accumulations. When cartilage slabs were exposed before embedment to the ionophore monensin to disrupt intracellular transport through the Golgi, it was possible to define differential subcompartments of the Golgi complex, based upon sites of sugar addition. Also, it was possible to characterize the cytoplasmic deposits of reserve‐zone chondrocytes which were positive with concanavalin A as glycogen, based upon their sensitivity to amylase. This method allows resolution at the light‐microscopic level of lectin‐binding glycoconjugates with localization to specific organelles. Patterns of intracellular binding were consistent with biochemical data relating to the subcellular localization of processing steps of complex carbohydrate

ISSN:0002-9106    

DOI:10.1002/aja.1001740406

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

年代:1985

数据来源: WILEY

摘要:

AbstractSolitary cilia have been observed on rabbit oviductal epithelial cells. In tissue cultures of fimbrial epithelium of 3‐ and 4‐day‐old animals observed by phase microscopy, most of these single cilia exhibited a vortical or funnel‐type movement while others had the usual to‐and‐fro motility. Primary cilia are usually considered immotile. Transmission electron microscopy of specifically identified single cilia revealed differences between the ciliary shafts and basal bodies of the single cilia as compared to those of mature oviductal ciliated cells. The basal body of the solitary cilium often had at least two triangular, striated, basal foot processes, lacked electron‐dense satellite material around its basal end, and occasionally had striated rootlets. In contrast, the cilia of mature ciliated cells had only one basal foot, exhibited much electron‐dense satellite material, and lacked rootlets. Cross sections of the single cilia showed patterns of microtubules different from the usual 9 + 2 axonemal complexes of normal cilia and included 9 + 0, 10 + 2 singlets, 7 + 2 doublets, and 8 + 1 doublet and 2 singlets; one did have the usual 9 + 2 arrangement. We postulate that the presence of more than one basal foot process may be responsible for the vortical motility observed. The primary cilia are shorter than normal cilia; the longest one measured was 1.86 μm in length, 0.28 μm in width at its base, and 0.14 μm at its tip. Based on the lightmicroscopic, scanning‐electron‐microscopic and transmission‐electron‐microscopic observations, such solitary cilia were observed more frequently in the oviductal tissues of the 3‐ to 4‐day postnatal rabbits grown in tissue culture and in ovariectomized and ovariectomized/progesterone‐treated adult animals than in estrous, ovulatory, or ovariect

ISSN:0002-9106    

DOI:10.1002/aja.1001740407

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe distribution of intramembranous particles (IMPs) and membrane filipin‐sterol complexes (FSC) was examined ultrastructurally in mouse spermatozoa from the male reproductive tract and ejaculates. IMPs were qualitatively analyzed on freeze‐fracture replicas of glutaraldehyde‐fixed tissue, while membrane FSC were quantitatively analyzed on replicas of filipin‐treated cells. The distribution pattern of IMPs of mouse spermatozoa was fundamentally similar to that of other mammalian spermatozoa. (1) In the head, the plasma membrane had a heterogeneous population density, e.g., few IMPs on the acrosomal region, particularly few on the marginal segment, and somewhat regularly arranged IMPs on the postacrosomal region. The acrosomal membrane had many IMPs in hexagonal arrays. The nuclear membrane had many IMPs on the P‐face, few IMPs on the variegated E‐face, and an intense population density on the P‐face of the basal plate. (2) In the neck, the plasma membrane had many IMPs with square arrangements of small IMPs in some areas on the P‐face; the redundant nuclear membrane had a few IMPs on both P‐ and E‐faces. (3) In the tail, the plasma membrane had diagonal rows of IMPs in some areas amongst larger IMPs on the middle piece, while it had „zippers”︁ composed of IMPs running parallel to the axis on the principal piece. The distribution of sperm membrane FSC may be summarized as follows: (1) In the head, the acrosomal plasma membrane, which was heavily labeled with filipin, had much more FSC in the equatorial segment than in the marginal segment throughout the study. The postacrosomal plasma membrane generally had no FSC, but some sperm in ejaculates were slightly positive to filipin. The acrosomal membranes (both outer and inner) had no FSC. The nuclear membrane in the main part of the head had less FSC in vas deferens and ejaculated sperm than in the epididymal sperm. The nuclear membrane on the basal plate had no FSC. (2) In the neck, the plasma membrane had little FSC. The redundant nuclear envelope had scattered FSC with a higher incidence in the epididymal sperm than in those from the vas deferens and ejaculates. The membrane scroll, which was elongated from the extreme caudal end of the redundant nuclear envelope, had abundant FSC in the vas deferens and ejaculated sperem. (3) The tail plasma membrane (both middle and principal piece), which was weakly labeled with filipin, had less FSC in sperm from the vas deferens and ejaculates than in those from the epididymis. The limiting membrane covering th

ISSN:0002-9106    

DOI:10.1002/aja.1001740408

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

年代:1985

数据来源: WILEY

摘要:

AbstractDuring the period of rapid elongation prior to the initiation of placental attachment (days 12–16 of gestation), the ovine blastocyst consists of a single layer (primarily) of roughly cuboidal trophoblastic cells with an inner lining of flattened endodermal cells. Well‐developed spot desmosomes link the adjacent cell borders in both the trophoblastic and endodermal layers. The trophoblastic cells contain acid phosphatase‐positive, lysosomelike organelles, the mean diameter of which increases greatly between days 12 and 16 and whose contents vary during development. Also during the developmental period studied, trophoblast cells accumulate lipid; and periodic acid‐Schiff‐positive binucleate cells appear within the trophoblast layer. A consistent observation throughout the 5 days of rapid growth and differentiation of the blastocyst was the death and disintegration of some trophoblast cells. These disintegrating cells are usually singly dispersed within the trophoblast, although occasionally groups of four or five are observed. The cell death may indicate overall remodelling of the blastocyst, or the cells may represent genetically deficient cells which are unable to respond to the appropriate signal to diff

ISSN:0002-9106    

DOI:10.1002/aja.1001740409

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

年代:1985

数据来源: WILEY

ISSN:0002-9106    

DOI:10.1002/aja.1001740410

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

年代:1985

数据来源: WILEY

ISSN:0002-9106    

DOI:10.1002/aja.1001740401

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

年代:1985

数据来源: WILEY