摘要:

AbstractA common lineage between monocytes and osteoclasts has been suggested but not yet proved, and an osteoclast precursor might be an immature cell of the monocyte‐macrophage family. We therefore compared the ability of cord blood and adult monocytes in long‐term culture to differentiate toward osteoclasts. Both adult and cord monocytes were cultured for 3 weeks in the presence of 20% horse serum. The proportion of multinucleated cells formed was influenced by 1,25(OH)2D3in cord, but not in adult monocyte cultures: 10−9M 1,25(OH)2D3increased multinucleated cells from 13 ± 2 to 26 ± 1% of total cells in cord monocyte cultures. The formation of multinucleated cells in cord monocyte cultures, in the presence of 10−9M 1,25(OH)2D, was decreased by salmon calcitonin (dose dependently from 10−8to 10−6M) and increased by 1—34 parathormone (100 ng/ml). None of these hormones induced any modification of the proportion of multinucleated cells formed in adult monocytes culture. Specific antigens on the membrane of the cells obtained after 3 weeks culture in the presence of 10−9M 1,25(OH)2D3were assessed by immunocytochemistry. The respective proportion of adult and cord labeled cells was 64 ± 11 vs. 63 ± 6% with Leu M5 (specific for monocyte) and 68 ± 7 vs. 30 ± 10% (P<0.05) with the anti‐HLA DR antibody. The monoclonal antibody 23C6 is specific to the vitronectin receptor, which is highly expressed by osteoclasts–41 ± 2% of the cells in cord monocyte cultures–but none in the adult monocytes culture were labeled with 23C6 at the end of the culture period. The ability of cells formed in cord monocyte culture to resorb devitalized bone on which they were cultured was investigated after 3 weeks culture. These cells did not release45Ca from devitalized45Ca‐prelabeled rat calvaria; they did not form an acidic extracellular compartment, as assessed by acridine orange fluorescence, and there was no ultrastructural evidence of a brush border at the interface with bone. In conclusion, cord blood monocytes in long‐term culture do not form mature osteoclasts. However, in contrast to adult monocytes, some acquire, in culture, characteristics of osteoclast precursors: sensitivity to osteotropic hormones and expression of an oste

ISSN:0003-276X    

DOI:10.1002/ar.1092260102

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe binding of a panel of blood group‐reactive lectins to frozen sections of human kidney was studied with a special emphasis on reactivity with endothelia and basement membranes. The blood group A‐reactive lectins, all specific for α‐D‐N‐acetylgalactosamine (GalNAc),Helix aspersa(HAA),Helix pomatia(HPA), andGriffonia simplicifoliaI‐A4(GSA‐I‐A4) agglutinins bound to the endothelium in specimens with blood groups A and AB. In other samples, these lectins reacted predominantly with tubular basement membranes, as well as with certain tubules. BothDolichos biflorus(DBA) andVicia villosaagglutinins (VVA), reported to react with blood group A1substance, failed to reveal endothelia in most specimens, but bound differently to tubules in all blood groups. The blood group B‐reactive lectins, specific for α‐D‐galactose (α‐Gal) or GalNAc, respectively, GSA‐I‐B4andSophora japonicaagglutinin (SJA), bound to the endothelia in specimens from blood group B or AB and in other specimens bound only to certain tubules. Among the blood group O‐reactive lectins, specific for α‐L‐fucose (Fuc),Ulex europaeusI agglutinin (UEA‐I) conjugates, but not other lectins with a similar nominal specificity, bound strongly to endothelia in specimens with blood group O. The UEA‐I conjugates bound distinctly more faintly to endothelia in specimens of other blood groups. The present results indicate that lectins, binding to defined blood group determinants, react with endothelia in specimens of the respective blood group status. Furthermore, they suggest that basement membranes and some tubules in the human kidney show a distinct heterogeneity in their expression of saccharide resi

ISSN:0003-276X    

DOI:10.1002/ar.1092260103

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

年代:1990

数据来源: WILEY

摘要:

AbstractPrevious studies have revealed that amorphous elastin and microfibrils are structural entities of mammalian elastic fibers. Elastin shows a wide phylogenetic distribution, but the presence of elastin‐associated microfibrils has not been demonstrated in teleost aorta. Thus, we have ultrastructurally and cytochemically examined elastic fibers in the ventral aorta of eel, a teleost, by utilizing routine uranyl acetate and lead double staining, the tannic acid (pH 7.0)—uranyl acetate (TA‐UA) method, elastase en bloc digestion, Thiéry's periodic acid‐thiocarbohydrazide‐silver proteinate (PA‐TCH‐SP) method, and the horseradish‐peroxidase‐labeled concanavalin A (Con A) method. In the ventral aorta of eel, a little ultrastructural difference between elastic fibers in the intima and media and those in the adventitia was noticed, but in either tunic each elastic fiber was basically composed of a “fibrillar core” and surrounding microfibrils. The fibrillar core was a collection of fibrils which showed a tendency to coalesce with each other, and these constituent fibrils were TA‐UA positive and elastase‐sensitive, representing their nature of elastin. By contrast, microfibrils associated with the fibrillar core were TA‐UA negative and elastase‐resistant, and their glycoproteinaceous nature was demonstrated by PA‐TCH‐SP and Con A methods. Thus, this study provides evidence for the presence of elastin‐associated microfibrils in teleost aorta. These results are discussed in relation to the topographical difference

ISSN:0003-276X    

DOI:10.1002/ar.1092260104

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

年代:1990

数据来源: WILEY

摘要:

AbstractSheep and goat binucleate cells (BNC) play a central role in placental growth and development. This study reports a simple method for isolating 60‐70% pure populations of BNC of high viability. After incubation of the isolated BNC with a brief pulse of14C‐leucine or3H‐fucose or3H‐galactose, electron microscope autoradiography showed that label was eventually incorporated into the characteristic BNC granules via the Golgi body. Fucose and galactose initially showed a much higher Golgi body label than leucine, which was at first predominantly localised in the endoplasmic reticulum.35S‐methionine incorporation by BNC suspensions was extensive enough to allow an immunoprecipitation investigation which demonstrated that the protein hormone ovine placental lactogen and the SBU‐3 antigen were synthesised de novo. Previous studies with isolated BNC have shown a remarkable range of substances to be released into the incubation medium but not necessarily synthesised during the incubation. The results demonstrate unequivocally that isolated BNC's are capable of total synthesis in vitro of two of the proteins that these same cells are known to secr

ISSN:0003-276X    

DOI:10.1002/ar.1092260105

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

年代:1990

数据来源: WILEY

摘要:

AbstractWe have previously localized an antigen of oviductal origin to the zona pellucida of superovulated hamster oocytes (Kan et al.:Journal of Histochemistry and Cytochemistry36:1441—1447, 1988) and described the intracellular distribution of this antigen in the oviductal epithelium (Kan et al.:Biology of Reproduction40:585—598, 1989). These results led to our hypothesis that the oviduct is a bona fide site of origin of certain components of the zona pellucida. In this report, using the high resolution lectin‐gold approach withHelix pomatialectin (HPL)‐colloidal gold complex, we present cytochemical evidence to show that glycoconjugates containing terminal N‐acetyl‐D‐galactosamine residues are absent from the zona pellucida of ovarian oocytes but are synthesized and secreted by the nonciliated secretory cells of the oviduct and later become associated with well‐defined structural elements of the zona matrix of oocytes during passage through the oviduct. The nature of the HPL‐binding glycoconjugates was determined by biochemical analyses. Electrophoretic and immunological experiments demonstrated that the glycoconjugates correspond to the high molecular weight polydispersed glycoprotein that we have previously described. We have designated this glycoprotein “hamster oviductin 1” (IIm OV‐1). Our results further substantiate the belief that the oviduct is a source of origin of zona

ISSN:0003-276X    

DOI:10.1002/ar.1092260106

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe normal development of vascular and lymphatic capillaries in the right ventricular septomarginal band of the sheep heart was studied in 9 fetuses aged 60—143 days (term = 147 days), 14 lambs aged 1 day to 16 weeks, and 3 adults. Tissue was fixed by perfusion and examined with light and transmission electron microscopy.The septomarginal band is composed of working myocardium and a well‐defined peripheral bundle of Purkinje cells. Vascular capillaries of the working myocardium were closely apposed to myocardial cells. By contrast, vascular capillaries of the Purkinje bundle were situated within the connective tissue sheath and septa, at variable distances from the Purkinje cells. After birth, the capillaries of the Purkinje bundle were also found in grooves and tunnels within the Purkinje strands. The ultrastructure of fetal vascular capillaries associated with myocardial and Purkinje cells was initially similar, and characterized by an abundance of synthetic organelles in endothelial cells and pericytes. However, after 115 days in utero, capillary endothelium with diaphragmed fenestrae, 40—60 nm in width, were observed within the Purkinje bundle. The fenestrae attained an average frequency of 1 per 11 capillary cross sections just before term, and this was maintained in lambs and adults. The ultrastructure of lymphatic capillaries, which were not observed in the septomarginal band until just before term, changed little during develo

ISSN:0003-276X    

DOI:10.1002/ar.1092260107

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe heart of the least shrew,Cryptotis parvaSay, is an extremely active organ, capable of achieving rates of 800—1,200 beats/minute. The general features of myocardial cell ultrastructure in this insectivore are much like those of other small mammals; no single striking feature of fine structure is present to which the physiological properties of this heart might necessarily be attributed. Still there exist in these myocardial cells a number of atypical properties. These include (1) mitochondria having a wide variety of sizes and internal configurations (2) a pleiomorphic, highly ramified, small‐diameter transverse‐axial tubular system (TATS) (3) numerous “labyrinths,” which are proliferated components of the TATS, and (4) myofibril‐free regions, located both in juxtanuclear and other myoplasmic levels and populated by a concentration of TATS elements and fibrillar structures. Features (2) and (3) are also characteristic of another fast‐beating heart, that of the mouse. The sinoatrial and atrioventricular nodal regions, as well as a Purkinje system, have been identified in the least shrew heart, along with sparsely distributed atrial cells whose myofibrils contain proliferated Z‐band material. A feature frequently encountered in atrial working muscle cells is the occurrence of close appositions between gap junctions and tubules of sarcoplasmic reticulum; such appositions are also present in other regions of the shrew heart, as are complexes composed of gap junctions a

ISSN:0003-276X    

DOI:10.1002/ar.1092260108

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

年代:1990

数据来源: WILEY

摘要:

AbstractWe used immunocytochemical localization of tyrosine hydroxylase to trace the ontogenesis and anatomic distribution of sympathetic innervation in fetal, neonatal, and mature canine hearts. Sparse tyrosine hydroxylase‐positive neural tissue first appeared in the atrium, including sinoatrial and atrioventricular nodes, and the ventricular epicardium at midgestation and progressively increased in extent to reach the adult pattern by 2 months following birth. Sympathetic innervation of the atrioventricular bundle occurred relatively later, with no nerve processes in the neonate but a mature pattern by 2 months. At each developmental stage the atria contained more tyrosine hydroxylase‐positive neural tissue than the ventricles. Thus, sympathetic nerve processes appear in the developing canine heart earlier than was previously recognized. The time course of sympathetic innervation as defined by this anatomic study is in accord with electrophysiologic studies indicating progressive neonatal development of sympathetic effect which achieves maturity by 2 months of

ISSN:0003-276X    

DOI:10.1002/ar.1092260109

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

年代:1990

数据来源: WILEY

摘要:

AbstractLectin histochemistry was used to examine the expression of cell surface glycoconjugates during secondary neurulation in chick embryos. Fourteen lectins were applied to serial sections of the caudal region of embryos at the various stages of tail bud development. The lectinsBandeiraea simplicifolia, Dolichos biflorusagglutinin,Phaseolus vulgarisleukoagglutinin, soybean agglutinin,Sophora japonicaagglutinin,Ulex europaeusagglutinin and succinylated wheat germ agglutinin (sWGA) showed very light or no binding to the developing medullary cord of the tail bud. With the other lectins, staining occurred throughout the early tail bud and solid medullary cord. During cavitation, however, differential expression of cell surface glycoconjugates by different cell populations was observed. The lectins concanavalin A,Lens culinarisagglutinin,Pisum sativumagglutinin,Phaseolus vulgariserythroagglutinin,Ricinus communisagglutinin and WGA showed basic similarities in the distribution of lectin binding. Of these, the binding pattern of WGA was the most striking. As the medullary cord cells were separating into central mesenchymal and peripheral epithelial populations, WGA bound preferentially to the epithelial cells and the notochord. The lectin PNA, however, became preferentially bound to the mesenchymal cells. Heavy staining by WGA (specific for N‐acetylglucosamine and sialic acid) where sWGA staining (specific for N‐acetylglucosamine only) was faint suggested that WGA binding was due to the presence of sialic acid containing glycoconjuga

ISSN:0003-276X    

DOI:10.1002/ar.1092260110

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

年代:1990

数据来源: WILEY

摘要:

AbstractAlthough homogeneous in appearance, several lines of evidence suggest early (stage 17—19) limb mesenchymal cells are committed to particular cell lineages, e.g., myogenic or chondrogenic. However, subsequent expression of cell or tissue phenotype in the developing limb does not occur in a randomized process but rather in a spatially specific pattern. The potential regulatory mechanisms controlling the “patterned” expression of tissue phenotype in the limb have not been resolved. The purpose of this study was to determine if, prior to the formation of an apical ectodermal ridge, nondissociated limb mesenchyme has inherent morphogenetic potential to form nonrandomized patterns of tissue organization. The hypotheses to be tested were that, if provided a spatially permissive culture environment, (1) mesenchymal cells committed to a particular lineage would segregate into precursor (sub)populations prior to overt expression of phenotype and (2) the ultimate expression of atissuephenotype may be regulated, in part, by histogenic interactions between the precursor cell groups. For these studies, mesoblasts (intact mesenchyme minus ectoderm) from stage 17—19 hindlimb buds were explanted intact to the surface of a 1—3 mm thick hydrated lattice of repolymerized type I collagen and incubated for 2—11 days. Examination of cultures at variable intervals revealed three distinct temporal sequences (periods) which were arbitrarily termedearly morphogenesis(0—3 days),cytodifferentiation(3—5.5 days), andprimitive tissue formation(5.5—11 days) based on similarities toin situlimb development. By the end of the first period, the mesenchymal cells had sorted into three distinct precursor populations: (1) an epithelial‐like outgrowth of premyogenic and prefibrogenic cells at the surface of the gel lattice (termed the “surface subset”) which circumscribed, (2) a centrally positioned prechondrogenic condensate (“central subset”), and overlaid (3) a dispersed, population of free cells that invaded the collagen lattice (“seeded subset”). Subsequent cytodifferentiation led to the appearance of multinucleated myotubes within the surface subset and chondrification of the central subset. Cells of the seeded subset remained dispersed within the collagen lattice. Primitive histogenic events were initiated during the final period of development including (1) at sites where surface cells established boundaries with the central subset, collectives or “bundles” of variable sized myotubes were formed which became partially ensheathed by the attenuated processes of fibroblastlike cells; and (2) asecondarysite of chondrogenic activity was initiatedwithinthe gel lattice at the boundary between the central and seeded cell populations. Transformation of seeded fibroblasts into chondroblasts accompanied expansion of the secondary chondrogenic element within the gel lattice. Remaining cells of the seeded population which did not become incorporated (transformed) into the secondary site of chondrogenesis persisted as a dense stratified network of fibrous connective tissue. Removing the central subset after 2 days of culture inhibited the transformation of seeded fibroblasts into chondrogenic cells.These findings indicate that intact limb mesenchyme prior to the formation of a mature apical ridge and in the absence of dorsal/ventral ectoderm has the endogenous potential to segregate, cytodifferentiate, and interact to intiate tissue formation simi

ISSN:0003-276X    

DOI:10.1002/ar.1092260111

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

年代:1990

数据来源: WILEY