Showing papers in "Journal of Ultrastructure Research in 1982"

TL;DR: In this paper, a rat growth plate cartilage is used as a test model for a cartilage fixation method that yields homogeneous preservation throughout tissue blocks and reproducible results at the light and electron-microscopic levels.

TL;DR: It is demonstrated by the platinum-replication technique that MAP 2 (microtubuleassociated protein 2) is a long, thin, flexible structure and that the alpha helix content is actually very low.

TL;DR: In this paper, electron microscopy, electron diffraction, and high-spatial-resolution electron probe X-ray microanalysis have been used to characterize certain ultrastructural components observed in undecalcified, unfixed, and unstained thin sections of epiphyseal growth plate cartilage from normal 4-week-old rats.

TL;DR: The photoreceptor cells of the blowfly, Calliphora erythrocephala, have been shown to contain a well-developed network of subrhabdomeric (=submicrovillar) smooth endoplasmic reticulum (SER) cisternae, which suggest that the SER participates in the control of cytosolic free Ca 2+ in the submicromolar concentration range.

TL;DR: The results suggest that so-called “myofibroblasts”, which have been described as being prominent in the granulation tissue of contracting wounds, represent a reversible phenotypic modulation of fibroblast-type cells to a contractile state.

TL;DR: A new spermatozoon pattern, with retained ZD and anterior centrioles, resembles what was described earlier in a didymozoid and probably occurs often in Digenea and perhaps other Platyhelminthes as well.

TL;DR: The technique of serial sections has been employed to study spermiogenesis and spermatozoon of Gonapodasmius and the zone of differentiation (ZD) shows no centriole-like body and no striated root, and peripheralmicrotubules are of two types: laterally placed thick microtubules which are spaced and coincide with external bristles on the membrane; and dorsally and ventrally placed thin microtubule which are closely aligned.

TL;DR: The study demonstrated the necessity of serial sectioning in order to obtain adequate information about the number of different types of synoviocytes present in the intima and supported the interpretation that the synoviocyte represent two morphologically and functionally distinct types of cells which are characteristic of the synovial membrane.

TL;DR: It was concluded that formaldehyde fixation is mandatory for the selective staining of DNA in the Feulgen-like reaction with osmium—ammine/SO2 complex and that this staining procedure, by visualizing DNA structures up to the molecular level, may be considered as a tool to investigate the chromatin structure in thin sections.

TL;DR: It is demonstrated that major differences exist between enzymatic breakdown in vivo and in vitro and indicated that in species having thin egg envelopes the digestion in vivo of the ZRI is incomplete, whereas it is complete in species with thick envelopes.

TL;DR: Adult rat ventricular cardiac muscle cells were isolated enzymatically and cultured for 1 to 9 days, and the cells appeared to reorganize their contractile apparatus using a mechanism similar to that which occurs during normal mammalian cardiac muscle cell differentiation.

TL;DR: There is an apparent heterogeneity in the distribution of filipin-cholesterol complexes in the plasma membranes of cultured hepatocytes, thus indicating differences in their cholesterol content, and it is suggested that changes in membrane fluidity due to the low cholesterol content may play a role in the recognition and adhesion of cultured hepatitis.

TL;DR: The present investigation showed a different distribution pattern from that previously described in the literature, the highest volume density of matrix vesicles being found in the resting zone and the lowest in the zone of calcification, which seems to support the view that most of the matrixvesicles are formed from degenerating chondrocytes.

TL;DR: A phosphorylation of endogenous acceptor proteins has been shown to occur in the membranes of secretory granules and vesicles of prostatic origin in human seminal plasma and the organelle membranes phosphorylated under optimal conditions were significantly thicker than the controls and in the presence of inhibitors to the protein kinase when assessed by electron microscopy.

TL;DR: It is demonstrated that lens gap junctions have the ultrastructure that clearly characterizes gap junction structure in other tissues, consistent with the Unwin and Zampighi (1980) model of liver gap junctionructure.

TL;DR: In addition to their conventional role as an inhalent pore, porocytes were shown to possess a particle retention ability, which remained even in the case of complete closure of the ostia, which points out the importance of exopinacocytes in particle retention, bypassing the choanocytes in their capture role.

TL;DR: Investigation of the ultrastructure of myocytes isolated from the adult rat heart by in vitro perfusion with collagenase demonstrates that all the normal features of sarcolemmal structure are preserved in these isolated cells, and no irreversible damage is sustained as a consequence of separation of the intercalated discs.

TL;DR: The morphology of the spermatozoa from the testes of the catfish Ictalurus punctatus was studied by transmission and scanning electron microscopy and speculated as to the functional significance of these observations are made.

TL;DR: Events of scale morphogenesis and secretion were compared at the ultrastructural level in Synura, Mallomonas, and Paraphysomonas to reveal that the membrane of the scale-vesicles and that of the reticulum are different, even though they both play a role in scale formation.

TL;DR: The ultrastructure of nematocyte junctions in hydra tentacles was examined using thin sections and freeze-fracture replicas to interpret the NBM complex as a tandem arrangement of a fAscial desmosome and a fascial hemidesmosome.

TL;DR: There may be some relation between the binding of IgG to its receptor in the glycocalyx of the coated pit and the maintenance of the clathrin coat on the cytoplasmic aspect of the membrane, which may direct the coated vesicle away from the lysosomal system and permit the transmission of intact immunoglobulin.

TL;DR: It was noted that the axon “diameter” of fibers with g values of 0.5, 0.6, and 0.7 changed by +20, +15, +5 and 0%, respectively, while the most striking preparatory change at the nodes of Ranvier was widening of the node gaps.

TL;DR: It is clearly demonstrated with SEM that the cortical-granule exocytosis wave starts from the site of sperm entry, and the cell coat appears just as the cortical granule material is extruded; it is no longer possible to recognize the new membranes.

TL;DR: The chief structural and morphological features appear similar in zonular septate junctions of both the smooth and the pleated types, but in the latter type the septa of the bicellular junctions are finely pleated instead of being Smooth and the associated particles are more widely spaced whereas no clear cut difference was recognized between the trice cellular junctions.

TL;DR: It is concluded that epoxy resins should be labeled and handled as mutagens and suspect carcinogens and presented a protocol for minimizing inhalation and skin contact during resin use.

TL;DR: In this article, the midgut of a crustacean and an insect were comparatively studied, both in sections of lanthanum-impregnated tissues and on freeze-fracture replicas.

TL;DR: In this paper, the photoreceptor membrane turnover in the crab Callinectes sapidus has been compared when light adapted at noon and dark adapted at midnight between these two states photoreceptive membrane area increases by factors of 371 distally, 177 proximally, and 218 overall.

TL;DR: The preovulatory development of the human cumulus oophorus was studied using transmission and scanning electron microscopy and histochemical and freeze-fracture techniques to emphasize the complicated interactions between the gap junction-utilizing system and the system involving follicular fluid inhibitors in the control of human follicle development.

TL;DR: The ultrastructure of the septate junctions in the testis of Drosophila melanogaster was studied using stained and unstained preparations embedded at low temperature in Lowicryl HM20 and STEM micrographs of unstained samples clearly show a continuous septal structure spanning the apposed membranes from the cytoplasmic side of one membrane to the cytopsized side of the other.

TL;DR: A special magnetic cold table as support for electron microscopic grids has been developed and two test objects as examples for typical freeze-drying results are presented.