摘要:

AbstractAdult male rats were administered hydroxy‐cobalamin (c‐lactam) (HCCL), a vitamin B12analogue, by means of osmotic mini‐pumps. The metabolic effects of HCCL, are similar to those produced by simple dietary deficiency of vitamin B12(Frenkel et al., 1976), but the morphological alterations in hepatic mitochondria are quite different in the two treatments. In HCCL‐treated animals, hepatic mitochondria showed significant increases in number. In one rat, the hepatic mitochondria frequently had a single, elongated, circumferentially‐oriented crista, with the inner compartment being occupied by a greatly augmented matrix. Such organelles appeared to be capable of division, as indicated by medially‐partitioned forms. Numerous hooded mitochondria were present in the hepatic cells of the same animal. Almost every mitochondrion of whatever morphology was partially or completely shrouded by a cistern of rough endoplasmic reticulum. These mitochondrial morphological changes may be related to the chronic metabolic changes in this animal model of methylmalon

ISSN:0003-276X    

DOI:10.1002/ar.1092310102

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

年代:1991

数据来源: WILEY

摘要:

AbstractA study of the cervical lymph nodes from the fat‐tailed dunnart,Sminthopsis crassicaudata, revealed the nodes were pigmented with lipofuscin and contained many large cells which were identified as mast cells from their ultrastructure and histochemical staining properties. It is believed that the very high density of mast cells in the cervical lymph nodes contributed to an increase in size of these organs compared to other animals. Very high levels of histamine (90μpg/g)were found in the nodes. Cervical lymph nodes with these unusual features were found not only in healthy, unprimed laboratory bred adults, but also in pouch young, wild caught animals, and adults of the closely related species,Sminthopsis macroura.A comparison of the histochemical and ultrastructural characteristics of mast cells from various organs of adultS. crassicaudatawas also made. Mast cells from lymph node, skin, tongue, salivary glands, intestinal mucosa, and spleen showed slight variations in staining and structu

ISSN:0003-276X    

DOI:10.1002/ar.1092310103

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

年代:1991

数据来源: WILEY

摘要:

AbstractOccurrence of epidermal growth factor (EGF)‐binding sites during differentiation of cementoblasts and periodontal ligament (PDL) fibroblasts was investigated using radioautography after I. V. injection of125I‐EGF to 14‐day‐old rats. During differentiation of cementoblasts, a very low level of EGF‐binding sites was present on the mesenchymal cells in dental follicle proper, precementoblasts, and cementoblasts. On the other hand, during differentiation of PDL fibroblasts, numerous EGF‐binding sites were observed on the undifferentiated paravascular cells and on the perifollicular mesenchymes representing the major source of PDL fibroblast precursor cells. Also heavy labeling was observed throughout their differentiation to PDL fibroblasts, as well as during full synthetic activity as mature cells. Quantitative analysis of the light microscopic radioautographs revealed that these cells demonstrated approximately 4 grains per 100μm2of cell area. These results suggest that EGF plays an important role in differentiation of PDL fibroblasts, but not in that of cementoblasts. Furthermore, the well‐known in vivo effect of EGF in producing precocious eruption of teeth may be a consequence of a more extensive effect of EGF throughout differentiation of PDL fibroblasts as well as during full synthetic activity a

ISSN:0003-276X    

DOI:10.1002/ar.1092310104

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

年代:1991

数据来源: WILEY

摘要:

AbstractOsteopenia is a recognized complication of diabetes mellitus in humans and experimental animals. We recently found that tetracyclines prevent osteopenia in the streptozotocin‐induced diabetic rat and that this effect was associated with a restoration of defective osteoblast morphology (Golub et al., 1990). The present study extends these initial ultrastructural observations by assessing osteoblast function in the untreated and tetracycline‐treated diabetic rats. After a 3‐week protocol, non‐diabetic control and diabetic rats, including those orally administered a tetracycline, minocycline (MC), or a non‐antimicrobial tetracycline analog (CMT), were perfusion‐fixed with an aldehyde mixture; the humeri were dissected and processed for ultracytochemical localization of alkaline phosphatase (ALPase) and Ca‐ATPase activities. Some rats from each experimental group received an intravenous injection of3H‐proline as a radioprecursor of procollagen, and the humeri were processed for light microscopic autoradiography. In addition, the osteoid volume in each experimental group was quantitatively examined by morphometric analysis of electron micrographs.During the diabetic state, active cuboidal osteoblasts in the endosteum of control rats were replaced by flattened bone‐lining cells that contained few cytoplasmic organelles for protein synthesis (Golgi‐RER system), and active transport (mitochondria). Treating diabetic rats with MC, and even more so with CMT, appeared to “restore” osteoblast structure. During diabetes, bone‐lining cells incorporated little3H‐proline or secreted little labeled protein and produced only a very thin osteoid layer. Tetracycline administration to the diabetics increased both the incorporation of3H‐proline by osteoblasts and their secretion of labeled protein toward the osteoid matrix, in a pattern similar to that seen in the non‐diabetic controls. Intense alkaline phosphatase (ALPase) activity was cytochemically demonstrated along the plasma membranes of osteoblasts in the non‐diabetic control rats, but was completely absent from the bone‐lining cells in the diabetics. Similar to that described above, CMT therapy restored the ALPase activity in the diabetic osteoblasts and the effect of MC was less dramatic. The distribution and intensity of Ca‐ATPase in the osteoblast‐plasma membranes of the different groups of rats were similar to that of ALPase, except for the absence of detectable Ca‐ATPase in the MC‐treated diabetics. These results suggest that diabetes‐induced osteopenia reflects, al least in part, impaired osteoblast structure and function and that tetracyclines, by a non‐antimicrobial mechanism, may prevent this bone de

ISSN:0003-276X    

DOI:10.1002/ar.1092310105

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

年代:1991

数据来源: WILEY

摘要:

AbstractRenal glomerular basement membranes (GBMs) exhibit a charge‐selective barrier, consisting of heparan sulfate proteoglycan (HSPG) that restricts the passage of anionic molecules into the urine. Previous efforts to localize the HSPG core protein within various layers of the GBM have been contradictory. Furthermore, attempts to correlate proteinuria in several disease states with a decrease in anionic sites of HSPG core protein have yielded conflicting results.When antibodies to HSPG from the EHS tumor matrix [anti‐(EHS) HSPG] and GBMs [anti‐(GBM) HSPG]were used together with immunogold to label renal tissues from puromycin aminonucleoside nephrotic (PAN) rats, immunolabeling results indicated that a portion of the protein core recognized by anti‐(EHS) HSPG was significantly reduced, while immunolabeling with anti‐(GBM) HSPG was only slightly reduced in early PAN. Anionic sites (stained with the cationic probe, polyethyleneimine) within the lamina rara externa of the GBM remained unaltered throughout the cour

ISSN:0003-276X    

DOI:10.1002/ar.1092310106

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe renal cortex of tapirs, water‐loving primordial ungulates, was continuous, nonlobed, and about 80% of renal mass in adult and 71% in term‐neonate. In the neonates even the peripheral glomeruli were moderately mature.Tapirus bairdihad about 4 million glomeruli per kidney andT. pinchaqueabout 3 million smaller glomeruli. Number of glomeruli per gm of cortex was 12,444 inT. bairdiand 13,400 inT. pinchaque. Cortical loops were common in the medullary rays.The medulla was the simple crest‐type. The terminal collecting ducts (T.C.D.) opened separately at the crest and not into a tubus maximus. The “outer stripe” of the outer medulla apparently was telescoped into the deep cortex. The medullary loops turned at a thick portion and at nearly all levels of the medulla. The medullary crest was lined by urothelium which extended into the ends of the T.C.D. Otherwise the T.C.D. were made of columnar epithelium.The pelvic urothelium was continuous with that of the medullary crest at the dorsal and ventral fornices. The fornices were well within the inner medulla. Hence only inner medulla could be exposed to pelvic urine.The hilar arteries, unlike the other two perissodactyl families (rhinoceri and equids), passed through the cortico‐medullary (C‐M) border and some large arteries and veins passed through the outer medulla to and from the C‐M border without branches or tributaries. Unlike kidneys with a medullary crest in diverse eutherian mammals, tapirs lacked pelvic extensions along the major intrarenal blood vessels and thus lacked pelvic intervas

ISSN:0003-276X    

DOI:10.1002/ar.1092310107

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

年代:1991

数据来源: WILEY

摘要:

AbstractRecently, a cDNA that coded for an enteric smooth muscle γ‐actin (SMGA) that was expressed in post‐meiotic mouse testicular cells was identified. To determine the cellular location(s) of the protein encoded by this cDNA, this SMGA was probed for by immunocytochemistry in the cells of the seminiferous epithelium with two different monoclonal antibodies (Mabs), B4 and HUC 1–1, known to be muscle actin selective. As a control, we also examined the immunoreactivity of a third Mab, C4, that reacts with all non‐muscle and muscle vertebrate isoactins. Using light and electron microscopy, a progressive increase in immunolabeling was observed with the muscle selective HUC 1–1 Mab over a loose actin filamentous network distributed throughout the cytoplasm of steps 4–16 spermatids. Thereafter, the labeling decreased such that at step 17 spermatids, only cytoplasmic labeling in the tail of the spermatids was observed. No labeling of this network was noted with the C4 or B4 Mabs. However, myoid cells enveloping seminiferous tubules and smooth muscle cells of interstitial blood vessels demonstrated comparable intense labeling with each of the three Mabs. The C4 Mab intensely labeled actin filaments of the Sertoli‐Sertoli and Sertoli‐spermatid ectoplasmic specializations. Also well labeled were numerous actin filaments found in the apical Sertoli cell processes encapsulating the heads of late step 19 spermatids at stage VII of the cycle of the seminiferous epithelium. In addition, actin filamentous bundles enveloping tubulobulbar complexes of the late spermatids within the Sertoli cell apical processes were intensely labeled. The actin filaments in the Sertoli apical processes and surrounding the tubulobulbar complexes were also strongly immunolabeled with the HUC 1–1 Mab. The C4 Mab but not the B4 or HUC 1–1 Mabs, recognized actin in the subacrosomal space of steps 4–18 spermatids. This study suggests that there are muscle isoforms of actin within the cytoplasm of developing spermatids and within apical proc

ISSN:0003-276X    

DOI:10.1002/ar.1092310108

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

年代:1991

数据来源: WILEY

摘要:

AbstractAn ultrastructural, enzymohistochemical, and immunohistochemical study of the ductus epididymis in normal men was undertaken to investigate the characteristics of the apical mitochondria‐rich cells (AMRCs). These cells, which differ morphologically from the principal cells (PCs), appear in isolation in the caput epididymidis (5.8 ± 1.7 cells per cross‐sectional duct) and only occasionally in the corpus epididymidis. The morphologic appearance of AMRCs varies from slender cells extending from the basement membrane to the lumen to apical cells without apparent contact with the basement membrane. The former display a round pale nucleus located in the middle of the epithelium; the apical cells have a dark nucleus, which, surrounded by a narrow cytoplasmic band, protrudes into the lumen. The cytoplasm of AMRCs is electron‐dense and contains numerous mitochondria surrounded by rough endoplasmic reticulum cisternae. In the apical portion, there are lysosomes, vesicles with an electron‐dense granule, and vacuoles showing a variable size and content. The stereocilia are shorter and less numerous than those of the PCs. The AMRCs are similar to the PCs in the intensely positive reaction for the enzymatic activity acid phosphatase, as well as in the lack of reaction for alkaline phosphatase and phosphorylase activities. AMRCs differ from PCs in: (1) a more intense reaction to the enzymatic activities ATPase, NADP, and succinic dehydrogenease, (2) a more intense immunostaining by AE1/AE3 and Ks4.62 anti‐cytokeratin antibodies, and anti‐estradiol receptor protein (D5) antibodies, and (3) a lower staining affinity for epithelial membrane antigen (EMA) antibodies. No positive immunostaining for the anti‐cytokeratin Ks8.6 antibodies was observed in eithe

ISSN:0003-276X    

DOI:10.1002/ar.1092310109

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

年代:1991

数据来源: WILEY

摘要:

AbstractEctoplasmic specializations of Sertoli cells are actin containing structures found at sites of attachment to spermatids and to neighboring Sertoli cells. We suspect that these cytoskeletal structures are a form of actin‐associated adhesion junction. If this is true, then molecular components, such as vinculin, that characterize actin‐associated adhesion junctions in general should be present in ectoplasmic specializations.In this paper we have used two approaches to verify the prediction that vinculin is a component of ectoplasmic specializations. First, we have used fluorescence microscopy to probe immunologically for vinculin in ectoplasmic specializations associated with spermatids of the ground squirrel. Second, we have used immunogold techniques to probe for vinculin in ectoplasmic specializations of rat testis.Our results indicate that the immunological probe for vinculin was reactive with ectoplasmic specializations. In single label fluorescence experiments, linear patterns obtained with the vinculin probe were similar to those obtained with probes for filamentous actin. In double label experiments, the vinculin probe was codistributed with the actin probes. In immunogold studies, specific labelling with the probe for vinculin occurred in ectoplasmic specializations both at sites of attachment to spermatids and adjacent to basal Sertoli cell junctions. Moreover, gold particles were concentrated adjacent to filament bundles within each ectoplasmic specialization.Our results support the conclusion that vinculin is present in ectoplasmic specializations. Further, they indicate that vinculin is co‐distributed with actin bundles within each ectoplasmic specializ

ISSN:0003-276X    

DOI:10.1002/ar.1092310110

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

年代:1991

数据来源: WILEY

摘要:

AbstractFollicle regulatory protein (FRP) can exert paracrine control over follicular development. It is synthesized by the granulosa cells of the developing follicles and was localized in the cytoplasm of the mural cells by immunocytochemistry. When administered to male dogs and rats, FRP causes impairment of spermatogenesis. In the intact male rat, it has been postulated that FRP manifests its effects at a stage prior to the conversion of testosterone to dihydrotestosterone. Sertoli cells of the seminiferous tubules are implicated in testosterone metabolism. Furthermore, Sertoli cells in male gonads are regarded as the counterpart of granulosa cells in ovaries. The exact source of FRP in the male is not known. Therefore, it was of interest to study the localization of FRP in the male gonads. Testicular sections of the pig, dog, cat, rat, mouse, monkey, and man were immunocytochemically stained with monoclonal antibody to porcine FRP of ovarian origin. Sections of pig ovaries were used as controls throughout the study. Specificity of immunocytochemical localization was established by preabsorption. FRP antibody predominantly localized to the interstitial compartment of the pig testis. In the seminiferous tubules, FRP localization was limited to basal spermatogonia and Sertoli cells of tubules at few specific stages of spermatogenesis. The study also showed that the monoclonal antibody against porcine FRP is species‐specific. Antibody binding was found only in pig testis, whereas tissues from the cat, dog, mouse, rat, monkey, and man did not display any immunocytochemical reaction. Since in the pig testis, Sertoli cells at specific stages of spermatogenesis showed FRP localization, it would appear that FRP production is not being carried out by Sertoli cells at other stages. Due to the fact that all of the interstitial cells stained with FRP and some of the Sertoli cells were stained with FRP‐antibody, it is not possible to ascertain the exact cell type responsible for FRP synthesis and secretion in testis using immunocytochemistry. Since the antibody to FRP of ovarian follicular fluid origin bound to various testicular cells, it would appear that FRP or a protein of similar nature may also be present in the tes

ISSN:0003-276X    

DOI:10.1002/ar.1092310111

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

年代:1991

数据来源: WILEY