ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Artikel  (34)
  • Cell & Developmental Biology  (34)
  • 1
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Morphology 153 (1977), S. 427-460 
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The objectives of this research were to investigate the morphology of the thoracic skeleton and muscles of the mosquito, Culiseta inornata (Williston). The results are presented in 25 text figures and descriptions of each skeletal part and muscle. Undescribed exoskeletal structures are the postmediotergite, intersegmental cleft on the caudal margin of the metapleuron, and the parascutellar process. This process is considered a homologue of the fourth axillary. The acrotergite 2 and subalifer were identified. The prescutum has been called the paratergite by previous authors. The morphological basis for self amputation of legs is described. Undescribed parts of the endoskeleton are: lateral arm of sternal apophysis 1 and its socket on the mesal surface of coxa 1, furcopleural apodeme on sternal apophysis 1, precoxal and postcoxal apodemes arising from the ventral pleural arm, upper and lower laterotergite apodemes on the postnotum, and the pleural and intersegmental apodemes for attachment of halter muscles. Seventy-two muscles are illustrated with their attachments and the origin, insertion, and action of each is described. Ten of the muscles are newly described for the mosquito. There are no muscles inserted on the subalare, second axillary, or third axillary.
    Zusätzliches Material: 25 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Morphology 181 (1984), S. 69-86 
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Hymenopteran venom glands are epidermal glands that have evolved from female accessory reproductive glands. In the honey bee, Apis mellifera L., the venom gland shows many of the fine structural features of primitive glands. A honey bee venom gland is a simple, long, thin, distally bifurcated structure, opening into an ovoid reservoir. Along most of the length of the gland are similar secretory units that have four major components (secretory cells, duct cells, ducts, and end apparatuses), except in the part of the gland proximal to the venom reservoir, where the secretory units resemble those around the venom reservoir. In the latter secretory units a funnel structure occurs between the duct (which is shorter than that of the secretory units of the gland) and the end apparatus. This funnel may be important in protecting the secretory cells around the reservoir from the cytolytic activity of the complex chemical mixture constituting the venom.
    Zusätzliches Material: 18 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Morphology 183 (1985), S. 51-85 
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The objectives of this research were to investigate the morphology of the head skeleton and muscles of the female mosquito, Culiseta inornata (Williston). The skeletal parts were examined after maceration in KOH. The attachments of muscles were determined by dissection. Observations were made with the aid of a dissecting microscope at 70× and lower. Each skeletal part and muscle is illustrated and described. Conclusions regarding the skeleton are as follows: (1) the clypeal area is composed of an anteclypeus and postclypeus, (2) the suture between the anteclypeus and postclypeus is rigid and cannot function as a hinge, (3) the dorsal wall of the labrum terminates at its union with the anteclypeus, (4) the dorsal and epipharyngeal walls of the labrum are united apically, (5) the gena and postclypeus are not separated by a suture, and (6) the labellum is composed of three segments and the furca, of some authors, is absent. Twenty-five muscles were identified, and the origin, insertion, and action of each is described. The tormo-epipharyngalis muscle is attached anterior to the cibarium and fulcral plates. Its origin is on the clypeal apodeme and the insertion is on the epipharynx. This result confirms earlier reports and disagrees with some recent authors. The maxillary teeth are not designed to draw the fascicle into the tissues, but the cervical and leg muscles accomplish the probing process during feeding on a host. An undescribed muscle of the mandible is reported.
    Zusätzliches Material: 23 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Morphology 166 (1980), S. 155-178 
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The morphology of the abdominal skeleton and muscles of the adult mosquito is incompletely known. The objectives of this study were to investigate these features in a common species, Culiseta inornata (Williston). Preserved specimens were stained lightly with methylene blue and studied with a dissecting microscope at 70 × and lower. The sclerites of the pregenital segements are best developed in segment II. The base of segment VIII in the male is narrow and semicircular in shape. This modification aids in rotation of the terminalia. Two new names are introduced for parts of the terminalia. Apodeme of sternum 9 is proposed for atrial plate of the female. Gonocoxital apodeme is a new term for a structure in the male. Both of these structures serve for attachement of muscles. Terms preferred for parts of the male terminalia are: (1) gonocoxite and gonostylus for the clasping organ; (2) paramere for the sclerotized plates on each side of and joined to the aedeagus; (3) sternum 10 for paraprocts. Sternum 10 is used because the occurrence of true paraprocts in the Nematocera is questionable. Thirty-four muscles are illustrated, and the origin and insertion of each is described. Eighteen of the muscles are newly described for the mosquito. The rotational muscles of the male terminalia were identified. The results are presented in 21 text figures.
    Zusätzliches Material: 21 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    ISSN: 0730-2312
    Schlagwort(e): oncogenes ; osteoblasts ; osteocalcin ; alkaline phosphatase ; collagen ; transcription ; gene expression ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: There is a generalized reciprocal relationship between cell growth and expression of genes that occurs following completion of proliferation, which supports the progressive development of cell and tissue phenotypes. Molecular mechanisms which couple the shutdown of proliferation with initiation of tissue-specific gene transcription have been addressed experimentally in cultures of primary diploid osteoblasts that undergo a growth and differentiation developmental sequence. Evidence is presented for a model which postulates that genes transcribed post-proliferatively are suppressed during cell growth by binding of the Fos/Jun protein complex to AP-1 Promoter sites associated with vitamin D responsive elements of several genes encoding osteoblast phenotype markers (Type I collagen, alkaline phosphatase, osteocalcin).
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 45 (1991), S. 335-339 
    ISSN: 0730-2312
    Schlagwort(e): cytotoxic lymphocyte regulation ; IL-2 activated lymphocytes ; cytokine networks ; tumor necrosis factor ; interleukin-1 ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: High dose [〉 1 nM or 30 IU] interleukin-2 (IL-2) can induce MHC -unrestricted killing from various lymphoid populations. Although it is well established that CD16+ NK cells are the major source of blood-derived LAK precursors, other lymphoid cells, including several CD3+ T subsets can be a source of precursor activity. We hypothesize that most, if not all, lymphocytes with cytolytic potential may eventually express MHC-unrestricted killing, when provided with adequate IL-2 to intiate required secondary cytokine production. This perspective article presents our cumulative data supporting the role of secondary cytokines in the IL-2 initiated activation of MHC-unrestricted killing, first by our observations of synergy with the exogenously added TNFs or IL-1s in combination with low dose IL-2, and then by the evidence of endogenous cytokine production and response in lymphocytes stimulated with high dose IL-2.Understanding the amplification mechanism(s) of the various effector arms of the immune system is critical to the eventual regulation of graft rejection, autoimmune phenomena, and potentially to the treatment of cancer. Our studies have focused on the cytotoxic lymphocyte effector system, and have addressed the molecular pathways by which IL-2 induced cytokines influence the quantity and quality of the cytotoxic lymphocyte response.This article will review the pivotal role that IL-2 plays in the development of CTL (MHC-restricted antigen-specific cytotoxic lymphocytes), followed by the description of how studies in the CTL system led to the observation that IL-2 alone can activate a heterogeneous collection of MHC-unrestricted killer lymphocytes, originally known as “Lymphokine Activated Killers” or LAK. We will then describe experiments performed in out laboratory over the past several years demonstrating the positive regulation of LAK activity by exogenous addition of TNF-α, TNF-β, IL-1α or IL-1β. Finally, we will summarize our data and propose, in the context of the current literature, the endogenous autocrine/paracrine amplification network of secondary cytokines operative in the generation of LAK.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    ISSN: 0730-2312
    Schlagwort(e): HL-60 cells ; bone ; proliferation ; gene regulation ; hsp27 ; hsp60 ; hsp70 ; hsp89α ; hsp89β ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The progressive differentiation of both normal rat osteoblasts and HL-60 promyelocytic leukemia cells involves the sequential expression of specific genes encoding proteins that are characteristic of their respective developing cellular phenotypes. In addition to the selective expression of various phenotype marker genes, several members of the heat shock gene family exhibit differential expression throughout the developmental sequence of these two cell types. As determined by steady state mRNA levels, in both osteoblasts and HL-60 cells expression of hsp27, hsp60, hsp70, hsp89α, and hsp89β may be associated with the modifications in gene expression and cellular architecture that occur during differentiation.In both differentiation systems, the expression of hsp27 mRNA shows a 2.5-fold increase with the down-regulation of proliferation while hsp60 mRNA levels are maximal during active proliferation and subsequently decline post-proliferatively. mRNA expression of two members of the hsp90 family decreases with the shutdown of proliferation, with a parallel relationship between hsp89α mRNA levels and proliferation in osteoblasts and a delay in down-regulation of hsp89α mRNA levels in HL-60 cells and of hsp89β mRNA in both systems. Hsp70 mRNA rapidly increases, almost twofold, as proliferation decreases in HL-60 cells but during osteoblast growth and differentiation was only minimally detectable and showed no significant changes. Although the presence of the various hsp mRNA species is maintained at some level throughout the developmental sequence of both osteoblasts and HL-60 cells, changes in the extent to which the heat shock genes are expressed occur primarily in association with the decline of proliferative activity. The observed differences in patterns of expression for the various heat shock genes are consistent with involvement in mediating a series of regulatory events functionally related to the control of both cell growth and differentiation.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    ISSN: 0730-2312
    Schlagwort(e): MGP ; chondrogenesis ; osteogenesis ; gene expression ; vitamin D ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Matrix Gla protein (MGP), a vitamin K dependent protein, has recently been identified in many tissues. However, it is accumulated only in bone and cartilage suggesting that the expression of MGP may be related to the development and/or maintance of the phenotypic properties of these tissues. We systematically evaluated MGP mRNA expression as a function of bone and cartilage development and also as regulated by vitamin D during growth and cellular differentiation. Three experimental models of cartilage and bone development were employed:colon; an in vivo model for endochondral bone formation, as well as in primary cells of normal diploid rat chondrocyte and osteoblast cultures. MGP was expressed at the highest level during cartilage formation and calcification in vivo during endochondral bone formation. In chondrocyte cultures, MGP mRNA was present throughout the culture period but increased only after 3 weeks concomitantly with type I collagen mRNA. In osteoblast cultures, MGP mRNA was expressed during the proliferative period and exhibited increased expression during the period of matrix development. In contrast to osteocalcin (bone Gla protein), this increase was not dependent on mineralization but was related to the extent of differentiation associated with and potentially induced by extracellular matrix formation. During the proliferative period, type I collagen mRNA peaked and thereafter declined, while type I collagen protein steadily accumulated in the extracellular matrix. Constant MGP levels were maintained in the mineralization period of osteoblast differentiation in vitro which is consistent with the constant levels found during the osteogenic period of the in vivo system. MGP mRNA levels in both osteoblasts and chondrocytes in culture were significantly elevated by 1,25-(OH)2D3 (10-8 M, 48 h) throughout the time course of cellular growth and differentiation. Interestingly, when MGP mRNA transcripts from vitamin D treated and untreated chondrocytes and osteoblasts were analyzed by high resolution Northern blot analysis, we observed two distinct species of MGP mRNA in the vitamin D treated chondrocyte cultures while all other cultures examined exhibited only a single MGP mRNA transcript. Primer extension analysis indicated a single transcription start site in both osteoblasts and chondrocytes with or without vitamin D treatment, suggesting that the lower molecular weight MGP message in vitamin D treated chondrocytes may be related to a modification in post-transcriptional processing. In conclusion, these results show that the selective accumulation of MGP in bone and cartilage tissues in vitro may be related to the development and/or maintance of a collagenous matrix as reflected by increases in MGP mRNA during these periods. Moreover, our data suggest that cartilage and bone MGP mRNA may in part be selectively regulated by 1,25-(OH)2D3 at the post-transcriptional level.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    ISSN: 0730-2312
    Schlagwort(e): intracellular Ca2+ ; 1β25-(OH)2D3 ; ROS 17/2.8 ; OC mRNA ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: We have previously shown that one of the rapid nongenomic actions of 1α,25-dihydroxyvitamin D3 (1α,25-(OH)2D3), the increase in intracellular calcium (Ca2+), accompanies the increased osteocalcin (OC) mRNA steady-state levels in rat osteosarcoma cells. To determine the functional significance of the nongenomic actions, we have measured changes in intracellular Ca2+ as an indicator of the rapid effects and have assessed the effect of inhibition of the rapid increase in cellular Ca2+ by the inactive epimer, 1β,25-dihydroxyvitamin D3 (1β,25-(OH)2D3) on OC mRNA steady-state levels and transcription. 1β,25-dihydroxyvitamin D3 inhibited 1α,25-(OH)2D3 induced increases in intracellular Ca2+ and OC mRNA transcription at 1 hr and OC mRNA steady state levels at 3 hr. 1β,25-Dihydroxyvitamin D3 did not alter the binding of the vitamin D receptor complex to the vitamin D responsive element of the OC gene. The results demonstrate the functional importance of the rapid, nongenomic actions of 1α,25-(OH)2D3 in the genomic activation of the OC gene by the hormone in rat osteoblast-like cells, perhaps by modifying subtle structural and/or functional properties of the vitamin D-receptor DNA complex or by affecting other protein DNA interactions that support OC gene transcription. © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    ISSN: 0730-2312
    Schlagwort(e): osteocalcin ; CCAAT ; transcription ; phosphatase ; steroid-like half-elements ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: The rat osteocalcin gene encodes a 6-kD osteoblast-specific protein that is expressed postproliferatively. The developmental and steroid hormone responsive expression of the osteocalcin gene is transcriptionally regulated by a promoter with multiple basal and enhancer elements that exhibit activity controlled by a series of physiological mediators (e.g., 1,25(OH)2D3, glucocorticoids). In this study, we established the contribution of the rat osteocalcin (OC) box domain ( -99 to -76), a proximal basal element with a CCAAT motif as a central core, to transcriptional activity of the rat osteocalcin gene with in vivo co-transfection assays. By this same assay, however, the highly homologous (22 of 24 nt) human OC box element was unable to compete for transcription factor binding with the rat OC promoter. In vitro protein/DNA interaction studies confirm the presence of two protein binding sites in the OC box region, one of which overlaps the CCAAT motif and, at least in part, accounts for species-specific expression. Competition analysis established that the single nucleotide substitution of adenine for thymine, which converts the core motif of the rat OC box (CCAAT) to the core motif of the human OC box (CCAAA), accounts for observed species differences in transcription factor interactions. The CCAAT-specific protein/DNA interactions are heat stable and insensitive to phosphatase treatment. A second protein/DNA interaction located upstream of the CCAAT motif includes two steroid-like half-elements. These interactions are heat labile and sensitive to phosphatase treatment in contrast to the CCAAT-specific interactions. The human OC promoter contains only a single steroid-like half-element, while two steroid half-elements with an 11 nucleotide spacer are present in the rat OC promoter. These observed variations in sequence organization and transactivation factor binding in analogous proximal basal regulatory regions of the OC gene promoter may provide a basis for species-restricted variations in responsiveness to physiological mediators of OC gene expression at the transcriptional level.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...