摘要:

AbstractThrough a series of interrogatories, unsolved problems of antler evolution, anatomy, development, physiology, and pathology are probed, with commentaries on the following prospects for future research:1.How could these improbable appendages have evolved mechanisms to commit suicide, jettison the corpse, and regenerate new ones every year?2.By what developmental processes are antlers able to prescribe their own morphogenesis with mirror image accuracy year after year and in some cases produce deliberate asymmetries?3.What causes the scalp to transform into velvet skin as a deer's first antlers develop?4.Why do healing pedicle stumps give rise to antler buds instead of scar tissue?5.How is the unprecedented rate of antler elongation related to the diameter and length of the structure to be grown?6.How come wound healing by pedicle skin is held in abeyance for several months until new growth resumes?7.How is it that tropical deer regenerate antlers at any time of year, while in temperate zones deer do so in seasonal unison?8.How do deer find enough calcium to make such massive antlers in only a few months?9.What is the nature of the bizarre tumors that some antlers grow following castration? © 1995 Wiley‐Liss, I

ISSN:0003-276X    

DOI:10.1002/ar.1092410302

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

年代:1995

数据来源: WILEY

摘要:

AbstractBackground: Head‐kidney, considered the major fish lympho‐haemopoietic tissue, consists of cells of the different haemopoietic series supported by a network of stromal cells whose morphofunctional properties have not been established. We report the ultrastructure and cytochemical features of the reticulo‐endothelial stroma of the head‐kidney from the seawater teleost gilthead seabream (Sparus aurataL.).Methods: Samples of head‐kidney were processed for electron microscopic study. Some of the samples were incubated for acid and alkaline phosphatase, peroxidase, glucose‐6‐phosphatase, or ATPase.Results: The reticulo‐endothelial stroma of gilthead seabream head‐kidney consists of sinusoidal cells (endothelial and adventitial cells) and reticular cells (macrophage‐type reticulum and fibroblast‐like reticular cells). Transcytosis vesicles and rounded medium electron‐dense granules were observed in the cytoplasm of the endothelial cells. The adventitial cells partially covered the outside surface of the endothelial cells and were joined by desmosomes. The macrophage‐type reticulum cells were characterized by their cytoplasmic processes and acid phosphatase positive lysosomes. The fibroblast‐like reticular cells were joined by desmosomes and formed an extensive network between the haemopoietic parenchyma. They were peroxidase negative and acid and alkaline phosphatase, glucose‐6‐phosphatase, β‐glucuronidase, and ATPase positive.Conclusions: The ultrastructural and cytochemical features of the reticulo‐endothelial stroma of the gilthead seabream head‐kidney are similar to those of mammalian bone marrow, suggesting phylogenetic analogies betwee

ISSN:0003-276X    

DOI:10.1002/ar.1092410303

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

年代:1995

数据来源: WILEY

摘要:

AbstractBackground: The junctional epithelium (JE) attaches the gingiva to the non‐vital tooth surface and has other unusual properties which protect the underlying periodontal tissues. The JE differs from other gingival and oral epithelia in its unusual expression of cytokeratins typical of both stratifying and of simple èpithelia, a phenotypic pattern possibly related to its specialized functions.Methods: The patterns of differentiation of rodent gingival and other epithelia were examined using monoclonal antibodies against various glycoconjugates which are expressed on epithelial cell surfaces and provide an alternative marker system for regionally‐differing patterns of cell maturation.Results: Markers that are typical of basal cells in other stratifying epithelia were expressed by all cell strata of JE. JE lacked differentiation markers typical of other stratifying oral epithelia but showed suprabasal expression of markers typically expressed by simple epithelia and specialized epithelia, such as taste buds.Conclusions: The phenotype of rodent JE differs from that of other oral epithelia and the pattern of differentiation assessed by its expression of glycoconjugates parallels that for other phenotypic markers, such as cytokeratins. Differentiation of rodent JE is similar to that of human JE. The functional significance of these patterns of expression is not yet clear but the markers characterizing this unusual epithelium in rodents may be associated with its behavior in periodontal disease and of value to experimental studies of its development.© 1995 Wiley‐Li

ISSN:0003-276X    

DOI:10.1002/ar.1092410304

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

年代:1995

数据来源: WILEY

摘要:

AbstractBackground: It is well known that all forms of cardiac arrest lead to global ischemia combined with alterations in cellular and interstitial volume. The aim of this study was to investigate the nature of these alterations with respect to different methods of cardiac arrest and establish the extent of their mutual influence at the onset as well as during the course of global ischemia.Methods: Three tested clinical methods were employed to induce cardiac arrest by a) aortic cross clamping, b) coronary perfusion with the cardioplegic solution St. Thomas, and c) coronary perfusion with the cardioplegic solution histidine‐tryptophane‐ketoglutarate (HTK). The arrested hearts were subjected to global ischemia at 25°C. The size of the myocytes, as well as the interstitial space of myocytes, was determined morphometrically. The contraction state of myocytes was evaluated according to a score.Results: We found that the degree of contraction, as well as nature of alterations in the cellular and interstitial volumes, depended both on the form of cardiac arrest and on the duration of ischemia. The following relationships were established. High contraction at the onset of ischemia leads to expulsion of fluid from the interstitium between bundles of myocytes into the tissue clefts increasing their size. The decrease in contraction during ischemia leads to narrower tissue clefts. Cellular swelling at the onset of and during ischemia is caused by volume shifts between intracellular and interstitial space. An increase in cellular volume during global ischemia and/or additional contraction reduce the interstitium within bundles of myocytes. Sufficient relaxation and/or interstitial edema enlarge the interstitium.Conclusions: Cellular and intersticial alterations seen at the onset and during the course of ischemia are dependent upon the method of cardiac arrest. Furthermore, a considerable mutual influence is exerted by the alterations in cellular and interstitial spaces. © 1995 Wiley‐Li

ISSN:0003-276X    

DOI:10.1002/ar.1092410305

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

年代:1995

数据来源: WILEY

摘要:

AbstractBackground: The effects of biomechanical stress on the growth and development of the mandibular condyle have been studied by many investigators. However, the role of the lateral pterygoid muscle in this development is not clear.Methods: Hyperfunction of the lateral pterygoid muscles of male 3‐weekold Sprague‐Dawley rats was induced by electrical stimulation, and the responses of the mandibular condyles were compared to control tissues by a double‐fluorescent staining technique using polyclonal antibodies against type I and type II collagen. Electrical stimulation consisted of repeated application (5 seconds on/5 seconds off) of a Hz current for up to 7 days.Results: In the first 2 days, cartilaginous tissues rich in type II collagen disappeared in the anterior and posterior areas, which were loaded by tensional force due to direct and indirect attachment of the lateral pterygoid muscles. Tissues in these areas were replaced by intramembranous bone that was reactive for type I collagen at 7 days. By the end of the experiment, the trabecula of the condyle was remodled more perpendicularly, thus resisting the compressive force due to hyperfunction of the lateral pterygoid muscles.Conclusions: These results suggest that the activity of the lateral pterygoid muscle might play a significant role in the differentiation of progenitor cells and in the maturation and calcification of chondrocytes in mandibular condyles. © 1995 Wiley‐L

ISSN:0003-276X    

DOI:10.1002/ar.1092410306

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

年代:1995

数据来源: WILEY

摘要:

AbstractBackground: The unbiased estimation of the capillary length density in skeletal muscle tissue Lv(cap/mus) has been performed in this study applying a new stereological methodology based on the use of vertical slices and the intersections of cycloid test curves with capillaries in a three‐dimensional space defined by systematically chosen fields of vision and the thickness of the sections.Methods: The following simple requirements must be fulfilled: selection of a fixed vertical axis in skeletal muscle, adequate systematic muscle sampling, obtention of vertical slices of constant and known thickness but indifferent in magnitude, superposition of a cycloid test system with the minor axis of cycloid curves positioned perpendicularly to the vertical axis, and counting the intersections between cycloid curves and capillaries. In our study, the vertical axis was defined as that which is parallel to the natural, major axis of the muscle where fibres and capillaries are arranged parallel to this axis. The muscle sampling was performed using the fractionator method, and 25 pm thick sections were chosen.Results: The application of the equation for estimation of Lv(cap/mus) permits determination of an average of 1,480 mm of capillaries per mm3of muscle tissue, knowing the number of intersections, section thickness, and the points hitting the muscle with a known ratio between cycloid test curve length to a test point.Conclusions: The estimation of Lv(cap/mus) is efficient, unbiasedly obtained, and no assumption on the degree of capillary anisotropy are required. © 1995 Wiley‐Liss,

ISSN:0003-276X    

DOI:10.1002/ar.1092410307

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

年代:1995

数据来源: WILEY

摘要:

AbstractBackground: The capillary network of the skeletal muscle was analyzed from a quantitative point of view with the purpose of determining the capillary length density—Lv(cap/mus). A recent stereological method was applied to estimate this quantity using vertical slice of unknown thickness.Methods: First, the whole muscle was systematically sampled according to the fractionator method. The capillary length density was estimated on each chosen field of vision where the vertical axis was always identified as parallel to the major axis of the muscle fibers. Three measurements were performed: count of intersections between capillaries and cycloid test lines, count of intersections between capillaries and straight test lines, and count of capillary end points corresponding to the intersections of capillaries with the parallel planes of the vertical slices.Results: The estimated capillary length density was 1,578 mm per mm3of skeletal muscle tissue. The average thickness of the vertical slices was also estimated as 23.4 μm, which is roughly 6% less than the thickness measured using the microcator information on the microscope stage displacement.Conclusions: The advantages of this methodology were bases on two main features: the method is assumption‐free on the degree of capillary and muscle anisotropy, and the thickness of the vertical slices need not be known nor constant. © 1995 Wiley‐Li

ISSN:0003-276X    

DOI:10.1002/ar.1092410308

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

年代:1995

数据来源: WILEY

摘要:

AbstractBackground: Angiogenesis (or neovascularization) is required for the growth of solid organ tumors and precedes invasion of the adjacent stroma by neoplastic cells. We investigated the relative density and distribution of cathepsin B (CB) immunostained microvessels (i.e., small blood vessels and capillaries) in benign prostatic hypersplasia (BPH), prostatic intraepithelial neoplasia (PIN), and prostatic adenocarcinoma (CAP) by immunocytochemical localization of an antibody directed against a cathepsin B‐derived synthetic peptide (Syn‐CB).Methods: We studied 16 formalin‐fixed, prostatectomy specimens that were embedded in paraffin/paraplast for histological examination by hematoxylin and eosin and immuno‐localization of the Syn‐CB antibody. Selected paraformaldehyde‐fixed specimens were embedded in K4M Lowicryl or LRWhite resins. We localized the antibody in thin sections using immunoelectron microscopy techniques.Results: Eight patients had BPH [4 patients with BPH alone, 2 with BPH and PIN, and 2 with BPH and CAP]. Ten cancer cases included one with Gleason histologic score 4, two with score 6, four with score 7, and three with score 8. In CAP cases, Gleason score 6 and 7 tumors had more microvessels than the score 4 or 8 tumors. In both BPH and CAP cases, the antibody was localized chiefly in the endothelial cells of microvessels, but occasionally inductal and glandular epithelial cells. Ultrastructurally, CB‐immunoreactive gold particles were markedly increased at the luminal and basal plasma membrane surfaces and folds of endothelial cells in neoplastic prostate, but not in the endothelial cells of BPH. Furthermore, the presence of CB localizing gold particles in collagen and smooth muscle fibers near the microvessels indicated leakage of the enzyme in prostatic stroma of neoplastic prostate. Similar leakage was not observed in BPH. Morphometric analysis showed that the relative density of microvessels increased two to three times in cancer patients when compared to patients with BPH alone. Our study also indicated that BPH associated with PIN or CAP had an increased density of microvessels when compared to BPH alone.Conclusions: Our study showed that the relative density and distribution of microvessels are the most important features of neovascularization in prostatic tumors. The relative density of microvessels increased in PIN and CAP when compared to BPH alone. Although the localization of CB is associated with lysosomes of endothelial cells in both BPH and CAP, there is a greater association of CB with the plasma membrances of endothelial cells in CAP than BPH. Immunoelectron microscopy provided evidence that CB might be involved in dissolution of basement membrances in neoplastic tumors during angiogenesis. CB localization has the potential of defining a role for this protease in degradation of extracellular matrix constituents during early steps of angiogenesis. ©1995 W

ISSN:0003-276X    

DOI:10.1002/ar.1092410309

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

年代:1995

数据来源: WILEY

摘要:

AbstractBackground: Little information is available on the structural relationship of cumulus‐oocyte complexes and the oviductal wall during the transport of cumulus‐oocyte complexes. Then, morphological changes of the oviductal wall during the passage of unfertilized cumulus‐oocyte complexes was examined chronologically in ICR mice 25–27 days of age injected with PMSG and hCG.Methods: Mice were sacrificed at 12, 14, 16, 18, and 24 hr after the injection of hCG to remove oviducts, and the height of mucosal folds, muscle layers, and epithelial cells were measured in the serial section stained with hematoxylin‐eosin or colloidal iron.Results: The height of the mucosal fold and muscle layer where cumulus‐oocyte complexes were located was less than that of the adjacent portions. At 12–18 hr of hCG injection (about 2–8 hr after ovulation), the ova with surrounding cumulus cells lie free in a wide lumen, and the muscular tissue consists of only 2 or 3 layers of cells, arranged mostly longitudinally. However, a neighboring portion without cumulus‐oocyte complexes, where the folds meet in the middle, appreciably restricts the free space in the lumen. After 24 hr of hCG administration, structural changes in the oviductal wall, where cumulus‐oocyte complexes were located, were no longer apparent. The number of cumulus cells surrounding the oocyte decreased during the passage through the oviduct. At 12–18 hr after hCG injection, about 140 cells were identified in the largest cross section of a cumulus‐oocyte complex, but, after 24 hr of hCG administration (about 14 hr after ovulation), an oocyte was surrounded with only about 25 cells.Conclusions: These results indicate that oocyte‐cumulus cell complexes influence the structure of the oviductal wall during the passage in the oviduc

ISSN:0003-276X    

DOI:10.1002/ar.1092410310

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

年代:1995

数据来源: WILEY

摘要:

AbstractBackground: We have previously localized an antigen of oviductal origin in the zona pellucida of postovulatory hamster ova. This antigen is a high molecular weight glycoprotein secreted by the non‐ciliated secretory cells of the oviduct and is later transferred to the zona pellucida of the oocyte during oviductal transit. This glycoprotein is rich in N‐acetyl‐D‐galactosamine residues and has been designated Hamster Oviductin‐1. In the present study, a monoclonal antibody (MAb) raised against this oviductin was used to detect the presence of this antigen in oviductal tissue during the estrous cycle.Methods: Twenty mature female golden hamsters were used and were divided into five groups of five animals each according to the five different stages of the estrous cycle. Quantitative immunocytochemistry was performed on MAb‐labeled thin sections of Lowicryl‐embedded ampullary region of hamster oviducts. Control experiments were also carried out to assess the specificity of the immunolabeling.Results: Quantitative analysis of the immunogold labeling indicated that maximum labeling for oviductin in the secretory granules of oviductal epithelial secretory cells was found around the time of ovulation, i.e., at estrus. The intensity of immunolabeling decreased from metestrus to diestrus 1, was at a minimum at diestrus 2, and started to increase at proestrus.Conclusion: Together, these quantitative results indicate that expression of oviductin in the secretory granules of the hamster oviductal secretory cells is stage specific. Maximum labeling for the antigen coincides with the time of ovulation suggesting an important role for the oviductal epithelium in contributing its secretory product to the zona pellucida of oocytes freshly released from the ovary. Since the oviduct is the site of sperm‐egg interaction and where fertilization and early embryo development take place, the maximal production of oviductin at the time of ovulation may facilitate some of these crucial steps during the intricate process of reproduction. © 1995

ISSN:0003-276X    

DOI:10.1002/ar.1092410311

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

年代:1995

数据来源: WILEY