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1

Prognostic Significance of Substaging according to the Depth of Lamina Propria Invasion in Primary T1 Transitional Cell Carcinoma of the Bladder  

PubMed Central

Purpose To evaluate the prognostic significance of the depth of lamina propria invasion in primary T1 transitional cell carcinoma (TCC) of the bladder. Materials and Methods We retrospectively reviewed the medical records of 183 patients with primary T1 TCC of the bladder who had undergone transurethral resection (TUR) at our institution. Substaging was defined according to the depth of lamina propria invasion as follows: T1a, superficial invasion of lamina propria; T1b, invasion into the muscularis mucosa (MM); T1c, invasion beyond the MM but not to the muscularis propria. The prognostic significance of various clinicopathological variables for recurrence and progression was analyzed. Results Of the 183 patients, substaging was T1a in 119, T1b in 57, and T1c in 7 patients. The recurrence rate was 32.8% for T1a and 40.6% for T1b/c, but there was no significant difference between the two groups. The progression rate was significantly different between the two groups: 5.8% in T1a and 21.9% in T1b/c (p=0.003). The cancer-specific mortality rate was also significantly different: 4.2% in T1a and 14.0% in T1b/c (p=0.036). In the univariate analysis, microscopic tumor architecture was the only significant prognostic factor for recurrence. In the univariate and multivariate analysis concerning progression, depth of lamina propria invasion and concomitant carcinoma in situ were significant prognostic factors. Conclusions Substaging according to the depth of lamina propria invasion in primary T1 TCC of the bladder was an independent prognostic factor for progression. This suggests that substaging would be helpful for guiding decisions about adjuvant therapies and follow-up strategies.

Lee, Ji Yong; Joo, Hee Jae; Cho, Dae Sung; Kim, Sun Il; Ahn, Hyun Soo

2012-01-01

2

New method for isolation of rat lamina propria macrophages in colonic tissue.  

PubMed

Studies on intestinal cells in the lamina propria are important for understanding the cellular and immune responses in the gut. There is a lack of specific isolating procedures of macrophage cells in rats. Two different procedures of macrophage isolation of the lamina propria in rats are compared: a standard mice protocol for lymphocyte isolation (A) adapted to rat samples and a new protocol developed specifically for rats (B). Significant differences are observed when analyzing the effect of the isolation method on the cell number, viability and phenotype. This has important implications when further functional studies are required. PMID:24816467

Bargalló, Ana; Abad, Laura; Odena, Gemma; Planas, Ramon; Bartolí, Ramon

2014-06-01

3

The lamina propria of the bovine seminiferous tubule.  

PubMed

The boundary tissue of bovine testicular seminiferous tubules exhibits remarkable regional differences at the level of the seminiferous tubule proper, as compared with its terminal segment. The basal lamina of the seminiferous tubule proper is multilayered and possesses knob-like protrusions. At the level of the terminal segment the basal lamina is highly specialized; in the region of the terminal plug candelabrum-like projections of the tubular basal lamina invade the bases of the modified supporting cells up to a depth of 3.5 microns. The adjoining surface of these supporting cells is densely studded with hemidesmosomes. The elongated peritubular cells are arranged in 3--5 concentric layers around the tubulus seminiferus proper but form a loose association at the level of the terminal segment. Where the terminal segment joins the testicular straight tubule, peritubular cells may assemble to constitute a contractile spiral. Elastic tissue is situated mainly subjacent to the tubular basal lamina and to a lesser degree between the peritubular cell layers. A peritubular space lined by endothelium-like cells may surround the seminiferous tubule proper and also the transitional zone of the terminal segment. PMID:574798

Wrobel, K H; Mademann, R; Sinowatz, F

1979-11-01

4

Preparation and purification of lymphocytes from the epithelium and lamina propria of murine small intestine  

Microsoft Academic Search

Existing methods for the production of lymphocytes from the small intestine have proved unsatisfactory when applied to the mouse. We report here a new method for the production of highly pure suspensions of lymphoid cells from the epithelial layer and lamina propria of mouse small intestine. The production and purification methods are described in detail. At least ten million lymphocytes

M D Davies; D M Parrott

1981-01-01

5

T cells of the human intestinal lamina propria are high producers of interleukin-10  

PubMed Central

Background and aim—Some of the recently observed functional features characteristic of immunocompetent cells residing in the human intestinal lamina propria could be mediated by interleukin- 10 (IL-10). To investigate the role of IL-10 in the human intestinal mucosa, the regulation of IL-10 production by lamina propria T lymphocytes (LPL-T) was determined and compared with that of peripheral blood T lymphocytes (PBL-T). ?Methods—Following activation by using different stimuli, IL-10 release by LPL-T and PBL-T into the supernatant was measured by enzyme linked immunosorbent assay (ELISA). In parallel, cell growth was determined by [3H]-thymidine incorporation. ?Results—Neither LPL-T nor PBL-T release IL-10 constitutively. Triggering through CD2 or the T cell receptor (TCR)/CD3 complex in the presence of autologous monocytes induces significantly greater IL-10 secretion by LPL-T than by PBL-T. Engagement of the CD45 receptor enhances IL-10 release and proliferation of CD2 triggered CD45RO+ PBL-T. In contrast, it reduces CD2 induced IL-10 production by LPL-T without altering cell growth significantly. ?Conclusions—Activated LPL-T release relatively high amounts of IL-10. Enhanced IL-10 production by activated LPL-T, in comparison with activated PBL-T, is not only related to the presence of a higher proportion of CD45RO+ T cells in the intestinal lamina propria, but is also caused by increased sensitivity of LPL-T to CD2 co-stimulation. The differential responsiveness of LPL-T, compared with PBL-T, to CD45 engagement demonstrates that CD45 could be involved in the altered CD2 reactivity of LPL-T. ?? Keywords: CD2; CD45; interleukin 10; lamina propria; T cell subsets; T lymphocytes

Braunstein, J; Qiao, L; Autschbach, F; Schurmann, G; Meuer, S

1997-01-01

6

Immune responses of TLR5 + lamina propria dendritic cells in enterobacterial infection  

Microsoft Academic Search

Toll-like receptors (TLRs) recognize distinct microbial components and induce innate immune responses. TLR5 has been shown\\u000a to recognize bacterial flagellin. Unlike other TLRs, TLR5 is not expressed on conventional dendritic cells or macrophages.\\u000a By contrast, TLR5 is mainly expressed on intestinal CD11c+ lamina propria cells (LPCs), which do not express TLR4. These cells detect pathogenic bacteria and secreted proinflammatory\\u000a cytokines,

Satoshi Uematsu; Shizuo Akira

2009-01-01

7

Increased production of soluble TLR2 by lamina propria mononuclear cells from ulcerative colitis patients.  

PubMed

Toll-like receptor 2 (TLR2) is a type I pattern recognition receptor that has been shown to participate in intestinal homeostasis. Its increased expression in the lamina propria has been associated with the pathogenesis in inflammatory bowel disease (IBD), such as ulcerative colitis (UC) and Crohn's disease (CD). Recently, soluble TLR2 (sTLR2) variants have been shown to counteract inflammatory responses driven by the cognate receptor. Despite the evident roles of TLR2 in intestinal immunity, no study has elucidated the production and cellular source of sTLR2 in IBD. Furthermore, an increase in the population of activated macrophages expressing TLR2 that infiltrates the intestine in IBD has been reported. We aimed first to assess the production of the sTLR2 by UC and CD organ culture biopsies and lamina propria mononuclear cells (LPMCs) as well as the levels of sTLR2 in serum, and then characterize the cell population from lamina propria producing the soluble protein. Mucosa explants, LPMCs and serum were obtained from UC, CD patients and control subjects. The level of sTLR2 was higher in conditioned media from organ culture biopsies and LPMCs from UC patients in comparison to CD and controls. Moreover, an inverse correlation between the content of intestinal and serum sTLR2 levels was observed in UC patients. Additionally, when characterizing the cellular source of the increased sTLR2 by LPMCs from UC patients, an increase in TLR2(+)/CD33(+) cell population was found. Also, these cells expressed CX3CR1, which was related to the increased levels of intestinal FKN in UC patients, suggesting that a higher proportion of TLR2(+) mononuclear cells infiltrate the lamina propria. The increased production of sTLR2 suggests that a differential regulating factor of the innate immune system is present in the intestinal mucosa of UC patients. PMID:22101184

Candia, Enzo; Díaz-Jiménez, David; Langjahr, Patricia; Núñez, Lucía E; de la Fuente, Marjorie; Farfán, Nancy; López-Kostner, Francisco; Abedrapo, Mario; Alvarez-Lobos, Manuel; Pinedo, George; Beltrán, Caroll J; González, Carlos; González, María-Julieta; Quera, Rodrigo; Hermoso, Marcela A

2012-06-01

8

Lamina propria and circulating interleukin-6 in newly diagnosed pediatric inflammatory bowel disease patients  

Microsoft Academic Search

OBJECTIVES:Understanding cytokine production patterns in early mucosal lesions of pediatric patients newly diagnosed with inflammatory bowel disease (IBD) may be critical to understanding IBD pathogenesis. Interleukin-6 (IL-6) has a central role in a multitude of immune system reactions; however, inconsistent lamina propria and serum IL-6 has been reported in IBD patients. Newly diagnosed pediatric IBD patients have not previously been

Kurt A. Brown; Susan J. Back; Eduardo D. Ruchelli; Jonathan Markowitz; Maria Mascarenhas; Ritu Verma; David A. Piccoli; Robert N. Baldassano

2002-01-01

9

LITAF Mediation of Increased TNF-alpha Secretion from Inflamed Colonic Lamina Propria Macrophages  

Microsoft Academic Search

Dysregulation of TNF-? in lamina propria macrophages (LPM) is a feature of inflammatory bowel diseases (IBD). LPS-Induced-TNF-Alpha-Factor (LITAF) is a transcription factor that mediates TNF-? expression. To determine whether LITAF participates in the mediation of TNF-? expression in acutely inflamed colonic tissues, we first established the TNBS-induced colonic inflammation model in C57BL\\/6 mice. LPM were harvested from non-inflamed and inflamed

Kristen N. Bushell; Susan E. Leeman; Earl Gillespie; Adam C. Gower; Karen L. Reed; Arthur F. Stucchi; James M. Becker; Salomon Amar; Gernot Zissel

2011-01-01

10

Modeling of the transient responses of the vocal fold lamina propria  

PubMed Central

The human voice is produced by flow-induced self-sustained oscillation of the vocal fold lamina propria. The mechanical properties of vocal fold tissues are important for understanding phonation, including the time-dependent and transient changes in fundamental frequency (F0). Cyclic uniaxial tensile tests were conducted on a group of specimens of the vocal fold lamina propria, including the superficial layer (vocal fold cover) (5 male, 5 female) and the deeper layers (vocal ligament) (6 male, 6 female). Results showed that the vocal fold lamina propria, like many other soft tissues, exhibits both elastic and viscous behavior. Specifically, the transient mechanical responses of cyclic stress relaxation and creep were observed. A three-network constitutive model composed of a hyperelastic equilibrium network in parallel with two viscoplastic time-dependent networks proves effective in characterizing the cyclic stress relaxation and creep behavior. For male vocal folds at a stretch of 1.4, significantly higher peak stress was found in the vocal ligament than in the vocal fold cover. Also, the male vocal ligament was significantly stiffer than the female vocal ligament. Our findings may help explain the mechanisms of some widely observed transient phenomena in F0 regulation during phonation, such as the global declination in F0 during the production of declarative sentences, and local F0 changes such as overshoot and undershoot.

Zhang, Kai; Siegmund, Thomas; Chan, Roger W.

2008-01-01

11

IL-2 production by intestinal lamina propria cells in normal inflamed and cancer-bearing colons.  

PubMed Central

Biologically significant levels of IL-2 activity were produced by isolated lamina propria mononuclear cells (LPMC) from normal intestine (n = 12), cancer-bearing colons (n = 35) and inflammatory bowel disease (IBD) affected tissue (n = 12). The levels of IL-2 produced were similar for all three sources of LPMC (normal 252 +/- 48 U/ml, IBD-affected mucosa 197 +/- 42 U/ml and colon cancer 285 +/- 43 U/ml). These levels were significantly greater than those produced by peripheral blood mononuclear cells (20 +/- 5 U/ml, P less than 0.01) on a per cell basis. In mucosa from cancer-bearing colons the amount of IL-2 produced by LPMC was unaffected by the invasiveness of the colon cancer. LPMC IL-2 production was markedly suppressed by drugs used in IBD therapy. 5-Aminosalicylic acid (5-ASA) reduced activity in a dose-dependent fashion. At a dose equivalent to the faecal therapeutic level of 0.5 mg/ml activity, IL-2 production by LPMC was suppressed to 3.4% of controls. Similarly, exposure of LPMC to cyclosporin A (CyA) and hydrocortisone (HC) at therapeutic levels reduced IL-2 activity to less than 1% of controls. The major producers of IL-2 activity were shown to be CD3+ T lymphocytes and those bearing the activation markers IL-2R and TFR. Suppression of mucosal IL-2 production represents an important therapeutic mechanism of drugs used in the management of IBD including HC, 5-ASA and CyA. These results suggest that mucosal T cells produce appreciable levels of IL-2 activity that may be important in maintaining immune homeostasis in the normal intestine, provide anti-neoplastic cytotoxic activity and contribute to the inflammatory events that characterize the mucosal lesions of IBD.

Pullman, W E; Doe, W F

1992-01-01

12

Spontaneous secretion of interferon ? and interleukin 4 by human intraepithelial and lamina propria gut lymphocytes  

PubMed Central

Background—Cytokines secreted by intestinal T lymphocytes probably play a critical role in regulation of the gut associated immune responses. ?Aims—To quantify interferon ? (IFN-?) and interleukin 4 (IL-4) secreting cells (SC) among human intraepithelial (IEL) and lamina propria (LPL) lymphocytes from the duodenum and right colon in non-pathological situations and in the absence of in vitro stimulation. ?Patients—Duodenal and right colonic biopsy specimens were obtained from patients with no inflammation of the intestinal mucosa. ?Methods—Intraepithelial and lamina propria cell suspensions were assayed for numbers of cells spontaneously secreting IFN-? and IL-4 by a two site reverse enzyme linked immunospot technique (ELISPOT). ?Results—The relatively high proportion of duodenal lymphocytes spontaneously secreting IFN-? (IEL 3.6%; LPL 1.9%) and IL-4 (IEL 1.3%; LPL 0.7%) contrasted with the very low numbers of spontaneously IFN-? SC and the absence of spontaneously IL-4 SC among peripheral blood mononuclear cells. In the basal state, both IFN-? and IL-4 were mainly produced by CD4+ cells. Within the colon, only 0.2% of IEL and LPL secreted IFN-? in the basal state, and 0.1% secreted IL-4. ?Conclusions—Compared with peripheral lymphocytes substantial proportions of intestinal epithelial and lamina propria lymphocytes spontaneously secrete IFN-? and/or IL-4. These cytokines are probably involved in the normal homoeostasis of the human intestinal mucosa. Disturbances in their secretion could play a role in the pathogenesis of gastrointestinal diseases. ?? Keywords: intestinal lymphocytes; ELISPOT; interferon ?; interleukin 4

Carol, M; Lambrechts, A; Van Gossum, A; Libin, M; Goldman, M; Mascart-Lemone, F

1998-01-01

13

Luminal DMSO: Effects on Detrusor and Urothelial/Lamina Propria Function  

PubMed Central

DMSO is used as a treatment for interstitial cystitis and this study examined the effects of luminal DMSO treatment on bladder function and histology. Porcine bladder was incubated without (controls) or with DMSO (50%) applied to the luminal surface and the release of ATP, acetylcholine, and LDH assessed during incubation and in tissues strips after DMSO incubation. Luminally applied DMSO caused ATP, Ach, and LDH release from the urothelial surface during treatment, with loss of urothelial layers also evident histologically. In strips of urothelium/lamina propria from DMSO pretreated bladders the release of both ATP and Ach was depressed, while contractile responses to carbachol were enhanced. Detrusor muscle contractile responses to carbachol were not affected by DMSO pretreatment, but neurogenic responses to electrical field stimulation were enhanced. The presence of an intact urothelium/lamina propria inhibited detrusor contraction to carbachol by 53% and this inhibition was significantly reduced in DMSO pretreated tissues. Detection of LDH in the treatment medium suggests that DMSO permeabilised urothelial membranes causing leakage of cytosolic contents including ATP and Ach rather than enhancing release of these mediators. The increase in contractile response and high levels of ATP are consistent with initial flare up in IC/PBS symptoms after DMSO treatment.

Smith, Katrina J.; Chess-Williams, Russ; McDermott, Catherine

2014-01-01

14

Intestinal lamina propria dendritic cell subsets have different origin and functions.  

PubMed

The intestinal immune system discriminates between tolerance toward the commensal microflora and robust responses to pathogens. Maintenance of this critical balance is attributed to mucosal dendritic cells (DCs) residing in organized lymphoid tissue and dispersed in the subepithelial lamina propria. In situ parameters of lamina propria DCs (lpDCs) remain poorly understood. Here, we combined conditional cell ablation and precursor-mediated in vivo reconstitution to establish that lpDC subsets have distinct origins and functions. CD103(+) CX(3)CR1(-) lpDCs arose from macrophage-DC precursors (MDPs) via DC-committed intermediates (pre-cDCs) through a Flt3L growth-factor-mediated pathway. CD11b(+) CD14(+) CX(3)CR1(+) lpDCs were derived from grafted Ly6C(hi) but not Ly6C(lo) monocytes under the control of GM-CSF. Mice reconstituted exclusively with CX(3)CR1(+) lpDCs when challenged in an innate colitis model developed severe intestinal inflammation that was driven by graft-derived TNF-alpha-secreting CX(3)CR1(+) lpDCs. Our results highlight the critical importance of the lpDC subset balance for robust gut homeostasis. PMID:19733097

Varol, Chen; Vallon-Eberhard, Alexandra; Elinav, Eran; Aychek, Tegest; Shapira, Yami; Luche, Hervé; Fehling, Hans Jörg; Hardt, Wolf-Dietrich; Shakhar, Guy; Jung, Steffen

2009-09-18

15

Empirical Measurements of Biomechanical Anisotropy of the Human Vocal Fold Lamina Propria  

PubMed Central

The vocal folds are known to be mechanically anisotropic due to the microstructural arrangement of fibrous proteins such as collagen and elastin in the lamina propria. Even though this has been known for many years, the biomechanical anisotropic properties have rarely been experimentally studied. We propose that an indentation procedure can be used with uniaxial tension in order to obtain an estimate of the biomechanical anisotropy within a single specimen. Experiments were performed on the lamina propria of three male and three female human vocal folds dissected from excised larynges. Two experiments were conducted: each specimen was subjected to cyclic uniaxial tensile loading in the longitudinal (i.e. anterior-posterior) direction, and then to cyclic indentation loading in the transverse (i.e. medial-lateral) direction. The indentation experiment was modeled as contact on a transversely isotropic half-space using the Barnett-Lothe tensors. The longitudinal elastic modulus EL was computed from the tensile test, and the transverse elastic modulus ET and longitudinal shear modulus GL were obtained by inverse analysis of the indentation force-displacement response. It was discovered that the average of EL/ET was 14 for the vocal ligament and 39 for the vocal fold cover specimens. Also, the average of EL/GL, a parameter important for models of phonation, was 28 for the vocal ligament and 54 for the vocal fold cover specimens. These measurements of anisotropy could contribute to more accurate models of fundamental frequency regulation and provide potentially better insights into the mechanics of vocal fold vibration.

Kelleher, Jordan E.; Siegmund, Thomas; Du, Mindy; Naseri, Elhum; Chan, Roger W.

2013-01-01

16

Intestinal lamina propria dendritic cells maintain T cell homeostasis but do not affect commensalism  

PubMed Central

Dendritic cells (DCs) in the intestinal lamina propria (LP) are composed of two CD103+ subsets that differ in CD11b expression. We report here that Langerin is expressed by human LP DCs and that transgenic human langerin drives expression in CD103+CD11b+ LP DCs in mice. This subset was ablated in huLangerin-DTA mice, resulting in reduced LP Th17 cells without affecting Th1 or T reg cells. Notably, cognate DC–T cell interactions were not required for Th17 development, as this response was intact in huLangerin-Cre I-A?fl/fl mice. In contrast, responses to intestinal infection or flagellin administration were unaffected by the absence of CD103+CD11b+ DCs. huLangerin-DTA x BatF3?/? mice lacked both CD103+ LP DC subsets, resulting in defective gut homing and fewer LP T reg cells. Despite these defects in LP DCs and resident T cells, we did not observe alterations of intestinal microbial communities. Thus, CD103+ LP DC subsets control T cell homeostasis through both nonredundant and overlapping mechanisms.

Welty, Nathan E.; Staley, Christopher; Ghilardi, Nico; Sadowsky, Michael J.; Igyarto, Botond Z.

2013-01-01

17

Characterization of lamina propria and vocal muscle in human vocal fold tissue by ultrasound Nakagami imaging  

PubMed Central

Purpose: A number of ultrasound techniques have been applied to identify the biomechanical properties of the vocal folds. These conventional ultrasound methods, however, are not capable of visually mapping the concentration of collagen and elastic fibers in the vocal folds in the form of a parametric image. This study proposes to use a statistical parameter, the Nakagami factor estimated from the statistical distribution of the ultrasonic signals backscattered from tissues, as a means for parametric imaging of the biomechanical properties of the vocal folds. Methods: The ultrasonic backscattered signals were acquired from four larynges (eight vocal folds) obtained from individuals without vocal fold pathology for constructing the Nakagami images. The textures of the Nakagami image in the lamina propria (LP) and the vocal muscle (VM) were observed and compared. The average and standard deviation of the Nakagami parameter for the LP and the VM were also calculated. Results: The results showed that the Nakagami parameter of the LP is larger than that of the VM. Moreover, the LP and the VM have different shading features in the Nakagami images. It was found that the Nakagami parameter may depend on the concentration of collagen and elastic fibers, demonstrating that the Nakagami imaging may allow visual differentiation between the LP and the VM in the vocal folds. Conclusions: Current preliminary results suggested that the high-frequency Nakagami imaging may allow real-time visual characterization of the vocal fold tissues in clinical routine examinations.

Tsui, Po-Hsiang; Huang, Chih-Chung; Sun, Lei; Dailey, Seth H.; Shung, K. Kirk

2011-01-01

18

Novel Isolation and Biochemical Characterization of Immortalized Fibroblasts for Tissue Engineering Vocal Fold Lamina Propria  

PubMed Central

Tissue regeneration of the vocal fold lamina propria extracellular matrix (ECM) will be facilitated by the use of suitable vocal fold fibroblast (VFF) cell lines in appropriate model systems. Primary human VFFs (hVFFs) were steadily transduced by a retroviral vector containing human telomerase reverse transcriptase (hTERT) gene; immortalized cells grew and divided vigorously for more than 120 days. Biochemical characterization of the six transduced lines included, at different time points, expression of hTERT, telomerase activity, telomere lengths, and transcript levels of ECM constituents. Telomere lengths of the transfected lines were elongated and stable. Gene expression levels of collagen I?1, collagen I?2, collagen VI?3, elastin, and fibronectin were measured between the transduced cell clones and the primary hVFFs to verify transcription. Absence of inter- and intraspecies contamination was confirmed with DNA fingerprinting and karyotype analysis. Cell morphology, growth, and transcription expression were examined on 2D scaffolds—collagen, fibronectin, and hyaluronic acid. Immortalized hVFFs demonstrated normal attachment and spread on 2D scaffolds. Collagen I?1, collagen I?2, collagen VI?3, elastin, and fibronectin transcript expression was measured from immortalized hVFFs, for all surfaces. This is the first report of immortalization and biochemical characterization of hVFFs, providing a novel and invaluable tool for tissue regeneration applications in the larynx.

Chen, Xia

2009-01-01

19

Initiation of an Inflammatory Response in Resident Intestinal Lamina Propria Cells -Use of a Human Organ Culture Model  

PubMed Central

Resident human lamina propria immune cells serve as powerful effectors in host defense. Molecular events associated with the initiation of an intestinal inflammatory response in these cells are largely unknown. Here, we aimed to characterize phenotypic and functional changes induced in these cells at the onset of intestinal inflammation using a human intestinal organ culture model. In this model, healthy human colonic mucosa was depleted of epithelial cells by EDTA treatment. Following loss of the epithelial layer, expression of the inflammatory mediators IL1B, IL6, IL8, IL23A, TNFA, CXCL2, and the surface receptors CD14, TLR2, CD86, CD54 was rapidly induced in resident lamina propria cells in situ as determined by qRT-PCR and immunohistology. Gene microarray analysis of lamina propria cells obtained by laser-capture microdissection provided an overview of global changes in gene expression occurring during the initiation of an intestinal inflammatory response in these cells. Bioinformatic analysis gave insight into signalling pathways mediating this inflammatory response. Furthermore, comparison with published microarray datasets of inflamed mucosa in vivo (ulcerative colitis) revealed a significant overlap of differentially regulated genes underlining the in vivo relevance of the organ culture model. Furthermore, genes never been previously associated with intestinal inflammation were identified using this model. The organ culture model characterized may be useful to study molecular mechanisms underlying the initiation of an intestinal inflammatory response in normal mucosa as well as potential alterations of this response in inflammatory bowel disease.

Schroder-Braunstein, Jutta; Gras, Judith; Brors, Benedikt; Schwarz, Sonja; Szikszai, Timea; Lasitschka, Felix; Wabnitz, Guido; Heidtmann, Antje; Lee, Young-Seon; Schiessling, Serin; Leowardi, Christine; Al-Saeedi, Mohammed; Ulrich, Alexis; Engelke, Antonia; Winter, Johannes; Samstag, Yvonne; Giese, Thomas; Meuer, Stefan

2014-01-01

20

Changes in lamina propria dendritic cells on the oral administration of exogenous protein antigens during weaning.  

PubMed

Two critical periods of maximum exposure to antigens occur in young mammals, immediately after birth and at weaning, as a result of colonization by commensal bacteria and the ingestion of new diets. At weaning, active immune responses of antibody production against dietary proteins are known to occur, but simultaneously, oral tolerance is acquired for harmless food proteins. However, regulated mechanisms of the immune system at weaning remain to be elucidated although its immune responses may be somewhat similar to those in adulthood. Considering that tolerogenic antigen-presenting cells (APCs) are likely to be a key factor in the acquisition of oral tolerance, in the present study, we examined the changes of dendritic cells (DCs) in the lamina propria (LP) on exposure to food proteins at weaning. C57BL/6 female mice were weaned at the age of 3 weeks and orally administered 10 mg of ovalbumin (OVA) for ten consecutive days after weaning. The administration led to a decrease in the plasma level of immunoglobulin specific for OVA, suggesting the acquisition of oral tolerance. The uptake of fluorescence-labeled OVA was significantly observed for CD11c(+)LPDCs. When we analyzed the changes of two types of LPDCs, PDCA-1(+) MHC II(+) DCs and CD103(+) MHC II(+) DCs, ten consecutive gavages of OVA marginally, but not significantly, augmented only the frequency of PDCA-1(+) MHC II(+) DCs. Considering that the change of APCs likely appears immediately on the response to antigen intake, we found the statistically significant increase in the frequency of PDCA-1(+) DCs, but not in that of CD103(+) DCs, even after two treatments, indicating PDCA-1(+) DCs to be recruited in the LP within 2 days of exposure to food proteins. These results suggest that the behavior of tolerogenic PDCA-1(+) DCs may change at weaning with the removal of the immunoprotective components of maternal milk. PMID:21509613

Ohue, Ryuji; Nakamoto, Masahiro; Kitabatake, Naofumi; Tani, Fumito

2012-05-01

21

Microbial colonization influences early B-lineage development in the gut lamina propria.  

PubMed

The RAG1/RAG2 endonuclease (RAG) initiates the V(D)J recombination reaction that assembles immunoglobulin heavy (IgH) and light (IgL) chain variable region exons from germline gene segments to generate primary antibody repertoires. IgH V(D)J assembly occurs in progenitor (pro-) B cells followed by that of IgL in precursor (pre-) B cells. Expression of IgH ? and IgL (Ig? or Ig?) chains generates IgM, which is expressed on immature B cells as the B-cell antigen-binding receptor (BCR). Rag expression can continue in immature B cells, allowing continued Ig? V(D)J recombination that replaces the initial V?J? exon with one that generates a new specificity. This 'receptor editing' process, which can also lead to Ig? V(D)J recombination and expression, provides a mechanism whereby antigen encounter at the Rag-expressing immature B-cell stage helps shape pre-immune BCR repertoires. As the major site of postnatal B-cell development, the bone marrow is the principal location of primary immunoglobulin repertoire diversification in mice. Here we report that early B-cell development also occurs within the mouse intestinal lamina propria (LP), where the associated V(D)J recombination/receptor editing processes modulate primary LP immunoglobulin repertoires. At weanling age in normally housed mice, the LP contains a population of Rag-expressing B-lineage cells that harbour intermediates indicative of ongoing V(D)J recombination and which contain cells with pro-B, pre-B and editing phenotypes. Consistent with LP-specific receptor editing, Rag-expressing LP B-lineage cells have similar VH repertoires, but significantly different V? repertoires, compared to those of Rag2-expressing bone marrow counterparts. Moreover, colonization of germ-free mice leads to an increased ratio of Ig?-expressing versus Ig?-expressing B cells specifically in the LP. We conclude that B-cell development occurs in the intestinal mucosa, where it is regulated by extracellular signals from commensal microbes that influence gut immunoglobulin repertoires. PMID:23965619

Wesemann, Duane R; Portuguese, Andrew J; Meyers, Robin M; Gallagher, Michael P; Cluff-Jones, Kendra; Magee, Jennifer M; Panchakshari, Rohit A; Rodig, Scott J; Kepler, Thomas B; Alt, Frederick W

2013-09-01

22

Interaction of lipopolysaccharide with human small intestinal lamina propria fibroblasts favors neutrophil migration and peripheral blood mononuclear cell adhesion by the production of proinflammatory mediators and adhesion molecules.  

PubMed

Fibroblasts are important effector cells having a potential role in augmenting the inflammatory responses in various diseases. In infantile diarrhea caused by enteropathogenic Escherichia coli (EPEC), the mechanism of inflammatory reactions at the mucosal site remains unknown. Although the potential involvement of fibroblasts in the pathogenesis of cryptococcus-induced diarrhea in pigs has been suggested, the precise role of lamina propria fibroblasts in the cellular pathogenesis of intestinal infection and inflammation caused by EPEC requires elucidation. Earlier we reported the lipopolysaccharide (LPS)-induced cell proliferation, and collagen synthesis and downregulation of nitric oxide in lamina propria fibroblasts. In this report, we present the profile of cytokines and adhesion molecules in the cultured and characterized human small intestinal lamina propria fibroblasts in relation to neutrophil migration and adhesion in response to lipopolysaccharide (LPS) extracted from EPEC 055:B5. Upon interaction with LPS (1-10 micrograms/ml), lamina propria fibroblasts produced a high level of proinflammatory mediators, interleukin (IL)-1alpha, IL-1beta, IL-6, IL-8, tumor necrosis factor (TNF)-alpha and cell adhesion molecules (CAM) such as intercellular cell adhesion molecule (ICAM), A-CAM, N-CAM and vitronectin in a time-dependent manner. LPS induced cell-associated IL-1alpha and IL-1beta, and IL-6, IL-8 and TNF-alpha as soluble form in the supernatant. Apart from ICAM, vitronectin, A-CAM, and N-CAM proteins were strongly induced in lamina propria fibroblasts by LPS. Adhesion of PBMC to LPS-treated lamina propria fibroblasts was ICAM-dependent. LPS-induced ICAM expression in lamina propria fibroblasts was modulated by whole blood, PBMC and neutrophils. Conditioned medium of LPS-treated lamina propria fibroblasts remarkably enhanced the neutrophil migration. The migration of neutrophils was inhibited by anti-IL-8 antibody. Co-culture of fibroblasts with neutrophils using polycarbonate membrane filters exhibited time-dependent migration of neutrophils. These findings indicate that the coordinate production of proinflammatory cytokines and adhesion molecules in lamina propria fibroblasts which do not classically belong to the immune system can influence the local inflammatory reactions at the intestinal mucosal site during bacterial infections and can influence the immune cell population residing in the lamina propria. PMID:10036324

Chakravortty, D; Kumar, K S

1999-02-24

23

Striking phenotypic and functional differences in lamina propria lymphocytes from the large and small intestine of mice.  

PubMed

Although intraepithelial T lymphocytes of the large intestine (LI) are known to differ from those of the small intestine (SI) in phenotype and function, differences in LI and SI lamina propria (LP) lymphocyte populations have not been clearly established. In this work we found striking phenotypic differences between SI and LI LP lymphocyte populations from Balb/c mice analyzed by flow cytometry. In the LI most lymphocytes were B cells and the predominant T cells were TCR-alpha beta+, CD8+. In contrast, in the SI most T lymphocytes were CD4+ expressing TCR-alpha beta+, although a higher proportion expressed TCR-gamma delta+ than in the LI. In T cells the expression of adhesion molecules and cytokines was also different between SI and LI. The proportion of LP T cells expressing alpha4beta7 and L-selectin was higher in the LI than in the SI; whereas a greater proportion of cells expressing alpha(E)beta7 were detected in the SI than in LI. Higher proportions of T cells expressing L-selectin and alpha4beta1 were detected in the intraepithelial compartment of the LI than that of the SI, whereas the number of T cells expressing alpha(E)beta7 was much higher in the SI than in the LI. The proportion of T cells spontaneously producing IL-2, IFN gamma, and IL-4 at the intraepithelial and lamina propria, in the small and large intestine, was different indicating that distinctive functional features exist in the lymphocyte populations residing at the different intestinal compartments. PMID:15808880

Reséndiz-Albor, Aldo Arturo; Esquivel, Rita; López-Revilla, Rubén; Verdín, Leticia; Moreno-Fierros, Leticia

2005-04-29

24

Aberrant activation of nuclear factor of activated T cell 2 in lamina propria mononuclear cells in ulcerative colitis  

PubMed Central

AIM: To investigate the role of nuclear factor of activated T cell 2 (NFAT2), the major NFAT protein in peripheral T cells, in sustained T cell activation and intractable inflammation in human ulcerative colitis (UC). METHODS: We used two-dimensional gel-electrophoresis, immunohistochemistry, double immunohistochemical staining, and confocal microscopy to inspect the expression of NFAT2 in 107, 15, 48 and 5 cases of UC, Crohn’s disease (CD), non-specific colitis, and 5 healthy individuals, respectively. RESULTS: Up-regulation with profound nucleo-translocation/activation of NFAT2 of lamina propria mononuclear cells (LPMC) of colonic mucosa was found specifically in the affected colonic mucosa from patients with UC, as compared to CD or NC (P < 0.001, Kruskal-Wallis test). Nucleo-translocation/activation of NFAT2 primarily occurred in CD8+T, but was less prominent in CD4+ T cells or CD20+B cells. It was strongly associated with the disease activity, including endoscopic stage (? = 0.2145, P = 0.0281) and histologic grade (? = 0.4167, P < 0.001). CONCLUSION: We disclose for the first time the nucleo-translocation/activatin of NFAT2 in lamina propria mononuclear cells in ulcerative colitis. Activation of NFAT2 was specific for ulcerative colitis and highly associated with disease activity. Since activation of NFAT2 is implicated in an auto-regulatory positive feedback loop of sustained T-cell activation and NFAT proteins play key roles in the calcium/calcineurin signaling pathways, our results not only provide new insights into the mechanism for sustained intractable inflammation, but also suggest the calcium-calcineurin/NFAT pathway as a new therapeutic target for ulcerative colitis.

Shih, Tsung-Chieh; Hsieh, Sen-Yung; Hsieh, Yi-Yueh; Chen, Tse-Chin; Yeh, Chien-Yu; Lin, Chun-Jung; Lin, Deng-Yn; Chiu, Cheng-Tang

2008-01-01

25

Total parenteral nutrition-associated lamina propria inflammation in mice is mediated by a MyD88 dependent mechanism  

PubMed Central

Background Enteral nutrient-deprivation, via total parenteral nutrition (TPN) administration leads to local mucosal inflammatory responses, but the underlying mechanisms are unknown. Methods Wild-type (WT) and MyD88-/- mice underwent jugular vein cannulation. One group received TPN without chow and controls received standard chow. After 7days, we harvested intestinal mucosally-associated bacteria, and isolated small-bowel lamina propria (LP) cells. Bacterial populations were analyzed using 454-pyrosequencing. LP cells were analyzed using quantitative PCR and multi-color flow cytometry. Results WT, control mucosally-associated microbiota were Firmicutes-dominant while WT TPN mice were Proteobacteria-domiant. Similar changes were observed in MyD88-/- mice with TPN administration. Unifrac analysis showed divergent small bowel and colonic bacterial communities in controls, merging towards similar microbiota (but distinct from controls) with TPN. The percentage of LP T-regulatory cells significantly decreased with TPN in WT mice. F4/80+CD11b+CD11cdull-neg macrophage derived pro-inflammatory cytokines significantly increased with TPN. These pro-inflammatory immunologic changes were significantly abrogated in MyD88-/- TPN mice. Conclusions TPN administration is associated with significant expansion of Proteobacteria within the intestinal microbiota and increased pro-inflammatory LP cytokines. MyD88 signaling blockade abrogated this pro-inflammatory response.

Miyasaka, Eiichi A.; Feng, Yongjia; Poroyko, Valeriy; Falkowski, Nicole R.; Erb-Downward, John; Gillilland, Merritt G.; Mason, Katie L.; Huffnagle, Gary B.; Teitelbaum, Daniel H.

2013-01-01

26

Small intestine lamina propria dendritic cells promote de novo generation of Foxp3 T reg cells via retinoic acid  

PubMed Central

To maintain immune homeostasis, the intestinal immune system has evolved redundant regulatory strategies. In this regard, the gut is home to a large number of regulatory T (T reg) cells, including the Foxp3+ T reg cell. Therefore, we hypothesized that the gut environment preferentially supports extrathymic T reg cell development. We show that peripheral conversion of CD4+ T cells to T reg cells occurs primarily in gut-associated lymphoid tissue (GALT) after oral exposure to antigen and in a lymphopenic environment. Dendritic cells (DCs) purified from the lamina propria (Lp; LpDCs) of the small intestine were found to promote a high level of T reg cell conversion relative to lymphoid organ–derived DCs. This enhanced conversion by LpDCs was dependent on TGF-? and retinoic acid (RA), which is a vitamin A metabolite highly expressed in GALT. Together, these data demonstrate that the intestinal immune system has evolved a self-contained strategy to promote T reg cell neoconversion.

Sun, Cheng-Ming; Hall, Jason A.; Blank, Rebecca B.; Bouladoux, Nicolas; Oukka, Mohamed; Mora, J. Rodrigo; Belkaid, Yasmine

2007-01-01

27

Uptake and storage of vitamin A as lipid droplets in the cytoplasm of cells in the lamina propria mucosae of the rat intestine.  

PubMed

Vitamin A (retinyl palmitate) was injected subcutaneously or administered to rats by tube feeding. After subcutaneous injection, vitamin A was taken up and stored in cells of the lamina propria mucosae of the rat intestine. After oral administration, vitamin A was absorbed by the intestinal absorptive epithelial cells and transferred to cells of the lamina propria mucosae, where cells took up and stored the transferred vitamin A. The morphology of these cells was similar to that of hepatic stellate cells (also called vitamin A-storing cells, lipocytes, interstitial cells, fat-storing cells or Ito cells). Thus, these cells in the intestine could take up vitamin A from the systemic circulation and as well as by intestinal absorption, and store the vitamin in the lipid droplets in their cytoplasm. The data suggest that these cells are extrahepatic stellate cells of the digestive tract that may play roles in both the absorption and homeostasis of vitamin A. PMID:23765517

Senoo, Haruki; Mezaki, Yoshihiro; Morii, Mayako; Hebiguchi, Taku; Miura, Mitsutaka; Imai, Katsuyuki

2013-11-01

28

Oral Administration of Bovine Milk from Cows Hyperimmunized with Intestinal Bacterin Stimulates Lamina Propria T Lymphocytes to Produce Th1-Biased Cytokines in Mice  

PubMed Central

The goal of this study was to examine the effects of oral administration of bovine milk from cows hyperimmunized with a proprietary bacterin (immune milk “Sustaina”) on mucosal immunity in the intestine of adult mice. C57BL/6 mice were orally given immune or control milk for two weeks, and then lymphocyte population and the cytokine production in lamina propria of colon in normal mice and mice induced colitis by dextran sulphate sodium (DSS) were detected. We found that the levels of IFN-? and IL-10 increased, but the levels of IL-17A and IL-4, decreased in lamina propria of colon in immune milk-fed mice as compared with those in control milk-fed mice. Interestingly, oral administration of immune milk partially improved the acute colitis induced by DSS. The levels of TNF-? and IFN-? increased, but IL-6, IL-17A and IL-4 decreased in lamina propria (LP) of colon in immune milk-fed mice with DSS-induced colitis. Our results suggest that immune milk may stimulate CD4+ T cells to polarize towards a Th1 type response, but contrarily suppress Th17 and Th2 cells responses in large intestinal LP of mice. The results indicate that this kind of immune milk has is able to promote the maintainance of intestinal homeostasis and enhance protection against infection, and could alleviate the symptoms of acute colitis in mice.

Wang, Yuanyuan; Lin, Lianjie; Yin, Chunming; Othtani, Satoru; Aoyama, Katsuhiko; Lu, Changlong; Sun, Xun; Yoshikai, Yasunobu

2014-01-01

29

Focused Examination of the Intestinal lamina Propria Yields Greater Molecular Insight into Mechanisms Underlying SIV Induced Immune Dysfunction  

PubMed Central

Background The Gastrointestinal (GI) tract is critical to AIDS pathogenesis as it is the primary site for viral transmission and a major site of viral replication and CD4+ T cell destruction. Consequently GI disease, a major complication of HIV/SIV infection can facilitate translocation of lumenal bacterial products causing localized/systemic immune activation leading to AIDS progression. Methodology/Principal Findings To better understand the molecular mechanisms underlying GI disease we analyzed global gene expression profiles sequentially in the intestine of the same animals prior to and at 21 and 90d post SIV infection (PI). More importantly we maximized information gathering by examining distinct mucosal components (intraepithelial lymphocytes, lamina propria leukocytes [LPL], epithelium and fibrovascular stroma) separately. The use of sequential intestinal resections combined with focused examination of distinct mucosal compartments represents novel approaches not previously attempted. Here we report data pertaining to the LPL. A significant increase (±1.7-fold) in immune defense/inflammation, cell adhesion/migration, cell signaling, transcription and cell division/differentiation genes were observed at 21 and 90d PI. Genes associated with the JAK-STAT pathway (IL21, IL12R, STAT5A, IL10, SOCS1) and T-cell activation (NFATc1, CDK6, Gelsolin, Moesin) were notably upregulated at 21d PI. Markedly downregulated genes at 21d PI included IL17D/IL27 and IL28B/IFN?3 (anti-HIV/viral), activation induced cytidine deaminase (B-cell function) and approximately 57 genes regulating oxidative phosphorylation, a critical metabolic shift associated with T-cell activation. The 90d transcriptome revealed further augmentation of inflammation (CXCL11, chitinase-1, JNK3), immune activation (CD38, semaphorin7A, CD109), B-cell dysfunction (CD70), intestinal microbial translocation (Lipopolysaccharide binding protein) and mitochondrial antiviral signaling (NLRX1) genes. Reduced expression of CD28, CD4, CD86, CD93, NFATc1 (T-cells), TLR8, IL8, CCL18, DECTIN1 (macrophages), HLA-DOA and GPR183 (B-cells) at 90d PI suggests further deterioration of overall immune function. Conclusions/Significance The reported transcriptional signatures provide significant new details on the molecular pathology of HIV/SIV induced GI disease and provide new opportunity for future investigation.

Mohan, Mahesh; Kaushal, Deepak; Aye, Pyone P.; Alvarez, Xavier; Veazey, Ronald S.; Lackner, Andrew A.

2012-01-01

30

Distribution of macrophages and granulocytes expressing L1 protein (calprotectin) in human Peyer's patches compared with normal ileal lamina propria and mesenteric lymph nodes.  

PubMed Central

Antibodies to the cytosolic leucocyte L1 protein (or calprotectin) were examined for reactivity with macrophages, neutrophils, and eosinophils identified by paired immunofluorescence staining in sections of normal human ileal mucosa, including Peyer's patches. Macrophages were recognised by expression of the myelomonocytic antigen CD68 (monoclonal antibody KP1). Neutrophilic granulocytes were identified by their content of neutrophil elastase, and eosinophilic granulocytes by monoclonal antibody EG2. Virtually all CD68+ macrophages in normal lamina propria and Peyer's patches were L1- and the same was true for most extravasated macrophages in normal peripheral lymph nodes. Some mesenteric lymph nodes, however, and all peripheral lymph nodes with overt pathological processes (malignant lymphoma) contained many CD68+L1+ macrophages. Numerous L1+ cells were also localised to the crypt region and to some extent beneath the villous epithelium in normal lamina propria, but they were mainly identified as EG2+ eosinophils. Such cells were remarkably scarce or absent beneath the follicle associated epithelium in the dome region of Peyer's patches, where CD68+L1- macrophages were abundant. Also subepithelial and interfollicular CD68- interdigitating dendritic cells in Peyer's patches (recognised by antibody to S-100 protein) were usually unreactive with L1 antibody. The L1 protein shows a broad spectrum of antimicrobial activities in vitro, and its putative antiproliferative properties are interesting in relation to the immunosuppression postulated to take place in lamina propria. The virtual absence of L1 producing cells beneath the follicle associated epithelium in Peyer's patches may support the immunostimulatory function of these macrophage rich structures, which are held to be crucial for induction of specific mucosal immunity. Images Figure 1 Figure 2 Figure 3

Bjerke, K; Halstensen, T S; Jahnsen, F; Pulford, K; Brandtzaeg, P

1993-01-01

31

Intestinal CD103+ CD11b+ lamina propria dendritic cells instruct intestinal epithelial cells to express antimicrobial proteins in response to Toll-like receptor 5 activation  

PubMed Central

Microbial penetration of the intestinal epithelial barrier triggers inflammatory responses that include induction of the bactericidal C-type lectin RegIII?. Systemic administration of flagellin, a bacterial protein that stimulates Toll-like receptor 5 (TLR5), induces epithelial expression of RegIII? and protects mice from intestinal colonization with antibiotic-resistant bacteria. Flagellin-induced RegIII? expression is IL-22-dependent, but how TLR signaling leads to IL-22 expression is incompletely defined. Using conditional depletion of lamina propria dendritic cell (LPDC) subsets, we demonstrated that CD103+ CD11b+ LPDCs, but not monocyte-derived CD103? CD11b+ LPDCs, expressed high amounts of IL-23 following bacterial flagellin administration and drove IL-22-dependent RegIII? production. Maximal expression of IL-23 subunits IL-23p19 and IL-12p40 occurred within 60 minutes of exposure to flagellin. IL-23 subsequently induced a burst of IL-22 followed by sustained RegIII? expression. Thus, CD103+ CD11b+ LPDCs, in addition to promoting long-term tolerance to ingested antigens, also rapidly produce IL-23 in response to detection of flagellin in the lamina propria.

Kinnebrew, Melissa A.; Buffie, Charlie G.; Diehl, Gretchen E.; Zenewicz, Lauren A.; Leiner, Ingrid; Hohl, Tobias M.; Flavell, Richard A.; Littman, Dan R.; Pamer, Eric G.

2012-01-01

32

Quantitative immunohistochemical assessment of IgA, IgM, IgG and antigen-specific immunoglobulin secreting plasma cells in pig small intestinal lamina propria.  

PubMed

Intestinal immune response plays an important defensive role for pathogens, particularly for those transmitted by the oro-faecal route or for foecal shedding modulation. This work examined three parts of intestine from twelve gilts experimentally infected with PCV2-spiked semen, six vaccinated (V group) and six unvaccinated (NV group) against PCV2, 29 and 53 days post infection (DPI). An immunohistochemical investigation for IgA-, IgG- and IgM-antibody bearing plasma cells (PCs) was run on intestinal samples coupled with a sandwich immunohistochemical method to reveal anti-PCV2 antibody-secreting PCs. Plasma cell density was compared in the two groups of animals at 29 and 53 DPI. The IgA, IgG and IgM PC density did not differ between groups but displayed an increase from the upper (villus) to the lower part of the crypts while a decreasing trend in PC density was identified from duodenum to ileum. In the NV group, no increase in anti-PCV2 PC density was demonstrable in the two sampling moment: the amounts of lamina propria PCV2-specific antibody-producing PCs remained constant, 10.55±4.24 and 10.06±5.01 at 29 DPI and 53 DPI, respectively. In the V group a significant increase in PCV2-specific antibody-producing PCs was observed over time. The amounts of PCV2-specific antibody-producing PCs increased from 9.37±13.36 at 29 DPI to 18.76±15.83 at 53 DPI. The data on IgA, IgM and IgG PC counts can be considered reference values in a population of adult pigs. The sandwich method can be proposed as a technique able to identify specific antibody-secreting PCs in formalin-fixed paraffin-embedded tissues. A practical application of the sandwich method is the demonstration of a "booster-like" response of the lamina propria in vaccinated compared to unvaccinated animals. After virus challenge, vaccination induced an increase in the number of PCs containing specific anti-PCV2 antibodies at the level of intestinal mucosa. PMID:24961900

Bianco, C; Felice, V; Panarese, S; Marrocco, R; Ostanello, F; Brunetti, B; Muscatello, L V; Leotti, G; Vila, T; Joisel, F; Sarli, G

2014-08-15

33

Evidence for Dendritic Cell-Dependent CD4+ T Helper-1 Type Responses to Commensal Bacteria in Normal Human Intestinal Lamina Propria  

PubMed Central

Reactivity of lamina propria (LP) T cells to commensal bacteria has been demonstrated in animal models of inflammatory bowel disease (IBD) and in humans with IBD, but few studies have evaluated the function of such cells in normal individuals. LP mononuclear cells (LPMC) were disaggregated from healthy human intestinal tissue and cultured with heat-killed commensal and pathogenic bacteria. CD3+CD4+ IFN-?-producing (Th1) cells reactive to commensal bacteria were demonstrated at frequencies ranging from 0.05 to 2.28% in LPMC. Bacteria-specific Th1 responses were inhibited by anti-HLA-DR antibodies and chloroquine exposure, were enriched in LP relative to peripheral blood, and expressed effector memory cell markers. Bacteria-specific CD4+ T cell proliferation in vitro was dependent on the presence of LP dendritic cells (DCs), which produced proinflammatory cytokines upon bacterial exposure. These results suggest that bacteria-reactive DCs and CD4+ T cells in normal LP have substantial pro-inflammatory potential that is revealed upon disaggregation in vitro.

Howe, Rawleigh; Dillon, Stephanie; Rogers, Lisa; McCarter, Martin; Kelly, Caleb; Gonzalez, Ricardo; Madinger, Nancy; Wilson, Cara C.

2009-01-01

34

CX3CR1(+) cells facilitate the activation of CD4 T cells in the colonic lamina propria during antigen-driven colitis.  

PubMed

Dendritic cells (DCs) and macrophages populate the intestinal lamina propria to initiate immune responses required for the maintenance of intestinal homeostasis. To investigate whether CX3CR1(+) phagocytes communicate with CD4 T cells during the development of transfer colitis, we established an antigen-driven colitis model induced by the adoptive transfer of DsRed OT-II cells in CX3CR1(GFP/+) × RAG(-/-) recipients challenged with Escherichia coli expressing ovalbumin (OVA) fused to a cyan fluorescent protein (CFP). After colonization of CX3CR1(GFP/+) × RAG(-/-) animals with red fluorescent E. coli pCherry-OVA, colonic CX3CR1(+) cells but not CD103(+) DCs phagocytosed E. coli pCherry-OVA. Degraded bacterial-derived antigens are transported by CD103(+) DCs to mesenteric lymph nodes (MLNs), where CD103(+) DCs prime naive T cells. In RAG(-/-) recipients reconstituted with OT II cells and gavaged with OVA-expressing E. coli, colonic CX3CR1(+) phagocytes are in close contact with CD4 T cells and presented bacterial-derived antigens to CD4 T cells to activate and expand effector T cells. PMID:24129164

Rossini, V; Zhurina, D; Radulovic, K; Manta, C; Walther, P; Riedel, C U; Niess, J H

2014-05-01

35

T-lymphocyte subsets in the duodenal lamina propria of patients infected with the human immunodeficiency virus type 1 and influence of high-dose immunoglobulin therapy.  

PubMed

T-lymphocyte subsets in duodenal biopsies of human immunodeficiency virus type 1 (HIV-1)-infected patients were studied by immunocytochemical staining to determine the alterations of CD4- and CD8-cell subsets in comparison with HIV-1 antibody-negative controls and to examine the association with stage, gastrointestinal symptoms, and peripheral lymphocyte subsets and the influence of high-dose intravenous immunoglobulins. A significant decrease in duodenal CD4 cells (p less than 0.001) and CD4/CD8 ratio (p less than 0.001) follows HIV-1 infection when compared to HIV-1-negative controls, more accentuated both in patients of stage WR6 and suffering from diarrhea than in those of stages WR1-5 or without diarrhea. In addition, a significant increase in CD8 cells (p less than 0.01) could be found in HIV-1-infected patients, again with lower levels in patients of stages WR6 than WR1-5. A strong correlation was found between the intestinal and peripheral CD4/CD8 ratio (R = 0.80), but the correlation was weak if HIV-1-negative persons were excluded from analysis (R = 0.29). Treatment with high-dose intravenous immunoglobulins improved diarrhea in four of five patients; two patients gained weight. Diffuse lymphocytic infiltration of the lamina propria, villous atrophy, CD4- and CD8-cell percentage, and CD4/CD8 ratio were not influenced. PMID:1968095

Schrappe-Bächer, M; Salzberger, B; Fätkenheuer, G; Franzen, C; Koch, B; Krueger, G R; Kaufmann, W

1990-01-01

36

Enhanced secretion of tumour necrosis factor-alpha, IL-6, and IL-1 beta by isolated lamina propria mononuclear cells from patients with ulcerative colitis and Crohn's disease.  

PubMed Central

The perpetuation of inflammation in ulcerative colitis and Crohn's disease may be regulated in part by an increased secretion of proinflammatory cytokines due to either an appropriate response to initial stimulating agents, and/or due to an impaired down-regulation of cytokine secretion. The aim of this study was to determine the secretion patterns of the proinflammatory cytokines tumour necrosis factor-alpha (TNF-alpha), IL-6 and IL-1 beta, from isolated lamina propria mononuclear cells (LPMNC) isolated from colonic biopsies from patients with untreated ulcerative colitis or Crohn's disease. LPMNC isolated from involved inflammatory bowel disease (IBD) mucosa spontaneously produced increased amounts of TNF-alpha, and IL-6, and IL-1 beta. The TNF-alpha secretion from IBD LPMNC could be further enhanced by pokeweed mitogen stimulation. The secretion patterns of TNF-alpha and IL-1 beta by LPMNC from patients with either ulcerative colitis or Crohn's disease demonstrated a close correlation with the degree of tissue involvement and mucosal inflammation. LPMNC from non-involved ulcerative colitis mucosa secreted markedly increased levels of IL-6 compared with non-involved Crohn's disease mucosa or control mucosa. The heightened IL-6 secretion from LPMNC from non-involved ulcerative colitis mucosa without visible or microscopic signs of inflammation indicates that the pathophysiologic mechanisms involved in the initiation of inflammation may differ between ulcerative colitis and Crohn's disease. The determination of proinflammatory cytokine secretion by isolated LPMNC from colonoscopic biopsies may be a sensitive method for monitoring the severity of mucosal inflammation in IBD patients.

Reinecker, H C; Steffen, M; Witthoeft, T; Pflueger, I; Schreiber, S; MacDermott, R P; Raedler, A

1993-01-01

37

Enhanced secretion of tumour necrosis factor-alpha, IL-6, and IL-1 beta by isolated lamina propria mononuclear cells from patients with ulcerative colitis and Crohn's disease.  

PubMed

The perpetuation of inflammation in ulcerative colitis and Crohn's disease may be regulated in part by an increased secretion of proinflammatory cytokines due to either an appropriate response to initial stimulating agents, and/or due to an impaired down-regulation of cytokine secretion. The aim of this study was to determine the secretion patterns of the proinflammatory cytokines tumour necrosis factor-alpha (TNF-alpha), IL-6 and IL-1 beta, from isolated lamina propria mononuclear cells (LPMNC) isolated from colonic biopsies from patients with untreated ulcerative colitis or Crohn's disease. LPMNC isolated from involved inflammatory bowel disease (IBD) mucosa spontaneously produced increased amounts of TNF-alpha, and IL-6, and IL-1 beta. The TNF-alpha secretion from IBD LPMNC could be further enhanced by pokeweed mitogen stimulation. The secretion patterns of TNF-alpha and IL-1 beta by LPMNC from patients with either ulcerative colitis or Crohn's disease demonstrated a close correlation with the degree of tissue involvement and mucosal inflammation. LPMNC from non-involved ulcerative colitis mucosa secreted markedly increased levels of IL-6 compared with non-involved Crohn's disease mucosa or control mucosa. The heightened IL-6 secretion from LPMNC from non-involved ulcerative colitis mucosa without visible or microscopic signs of inflammation indicates that the pathophysiologic mechanisms involved in the initiation of inflammation may differ between ulcerative colitis and Crohn's disease. The determination of proinflammatory cytokine secretion by isolated LPMNC from colonoscopic biopsies may be a sensitive method for monitoring the severity of mucosal inflammation in IBD patients. PMID:8403503

Reinecker, H C; Steffen, M; Witthoeft, T; Pflueger, I; Schreiber, S; MacDermott, R P; Raedler, A

1993-10-01

38

Distinct Compartmentalization of NF-?B Activity in Crypt and Crypt-Denuded Lamina Propria Precedes and Accompanies Hyperplasia and/or Colitis following Bacterial Infection  

PubMed Central

Citrobacter rodentium induces transmissible murine colonic hyperplasia (TMCH) and variable degrees of inflammation and necrosis depending upon the genetic background. Utilizing C. rodentium-induced TMCH in C3H/HeNHsd inbred mice, we observed significant crypt hyperplasia on days 3 and 7 preceding active colitis. NF-?B activity in the crypt-denuded lamina propria (CLP) increased within 24 h postinfection, followed by its activation in the crypts at day 3, which peaked by day 7. Increases in interleukin-?1 (IL-1?), IL-12(p40), and macrophage inflammatory protein 1? (MIP-1?) paralleled NF-?B activation, while increases in IL-1?/?, IL-6/IL-12(p40)/granulocyte colony-stimulating factor (G-CSF)/keratinocyte-derived chemokine (KC)/monocyte chemotactic protein 1 (MCP-1), and MIP-1? followed NF-?B activation leading to significant recruitment of neutrophils to the colonic mucosa and increased colonic myeloperoxidase (MPO) activity. Phosphorylation of the crypt cellular and nuclear p65 subunit at serines 276 and 536 led to functional NF-?B activation that facilitated expression of its downstream target, CXCL-1/KC, during TMCH. Distinct compartmentalization of phosphorylated extracellular signal-regulated kinase 1 and 2 ([ERK1/2] Thr180/Tyr182) and p38 (Thr202/Tyr204) in the CLP preceded increases in the crypts. Inhibition of ERK1/2 and p38 suppressed NF-?B activity in both crypts and the CLP. Dietary administration of 6% pectin or 4% curcumin in C. rodentium-infected mice also inhibited NF-?B activity and blocked CD3, F4/80, IL-1?/?, G-CSF/MCP-1/KC, and MPO activity in the CLP while not affecting NF-?B activity in the crypts. Thus, distinct compartmentalization of NF-?B activity in the crypts and the CLP regulates crypt hyperplasia and/or colitis, and dietary intervention may be a novel strategy to modulate NF-?B-dependent protective immunity to facilitate crypt regeneration following C. rodentium-induced pathogenesis.

Chandrakesan, Parthasarathy; Ahmed, Ishfaq; Chinthalapally, Anisha; Singh, Pomila; Awasthi, Shanjana; Anant, Shrikant

2012-01-01

39

Activation of peripheral blood and intestinal lamina propria lymphocytes in Crohn's disease. In vivo state of activation and in vitro response to stimulation as defined by the expression of early activation antigens.  

PubMed Central

In the present study the state of activation of either peripheral blood and intestinal lamina propria mononuclear cells in Crohn's disease was defined by investigating the expression of early activation antigens (namely the 4F2 antigen, the transferrin receptor and the interleukin-2 receptor). The expression of 4F2 and T9 antigens was greatly increased--in the peripheral blood and in the intestinal lamina propria whereas the proportion of interleukin-2 receptor bearing cells was much less pronounced. The counts of early activation antigens bearing cells in the lamina propria were quite comparable with those of the autologous peripheral cells. In the peripheral blood counts of 4F2 and T9 positive cells were very high in patients with active Crohn's disease but patients with quiescent disease also had a significantly raised proportion of 4F2 and T9 bearing cells. Only in those patients with no evidence of macroscopic disease (namely those resected without recurrence) the counts of early activation antigens bearing cells were within the normal range. The in vitro mitogen induced expression of early activation antigens on either peripheral and intestinal mononuclear cells of patients with Crohn's disease proved to be both quantitatively and qualitatively similar to that of the controls showing the full expression of 4F2, transferrin receptor, and interleukin-2 receptor. While demonstrating that in Crohn's disease there was no intrinsic defect of generation and expression of growth factors receptors by peripheral and intestinal lymphocytes, these results showed that there was a divergence in the expression of early activation antigens in vivo and in vitro. This would indicate that in Crohn's disease there is an in vivo increased population of preactivated rather than fully activated lymphocytes consisting of 4F2 and T9 bearing cells. The high proportion of these cells in the peripheral blood and in the intestine suggests that a chronic immune activation is present in these patients outside as well as within the affected bowel.

Pallone, F; Fais, S; Squarcia, O; Biancone, L; Pozzilli, P; Boirivant, M

1987-01-01

40

Essential roles of IL-6 trans-signaling in colonic epithelial cells, induced by the IL-6/soluble-IL-6 receptor derived from lamina propria macrophages, on the development of colitis-associated premalignant cancer in a murine model.  

PubMed

Activation of the IL-6/Stat3 via IL-6 trans-signaling plays an important role in the pathogenesis of inflammatory bowel disease. Colitis-associated cancer (CAC) is a large bowel cancer and occurs with long-standing inflammatory bowel disease. The role of the IL-6/Stat3 in the development of CAC has not been fully understood. We investigate whether IL-6 trans-signaling contributes to the development of CAC using a mouse colitis-associated premalignant cancer (CApC) model. Chronic colitis (CC) was induced in BALB/c mice using dextran sodium sulfate. CApC was induced by dextran sodium sulfate treatment to CC-affected mice. IL-6 expression was determined by quantitative RT-PCR and immunofluorescence staining in colon. Phospho-Stat3 expression was examined by Western blotting and immunofluorescence analysis. The expression of IL-6 receptors (i.e., the IL-6R alpha-chain and gp130) and tumor necrosis factor-alpha converting enzyme in the colon was examined by laser-capture microdissection and immunofluorescence staining. Soluble IL-6R alpha (sIL-6R alpha) was examined by Western blotting of epithelial cell-depleted colonic tissues. We also investigated whether a soluble gp130-Fc fusion protein could prevent CApC. IL-6 expression was increased in the colon of CC- and CApC-affected mice and was restricted to lamina propria-macrophages. The expression of IL-6R alpha and tumor necrosis factor-alpha converting enzyme was increased in the lamina propria CD11b-macrophages of CC-affected mice. sIL-6R alpha expression was also increased in these tissues. Reduced levels of IL-6R alpha generation were observed in the colonic epithelial cells of CC- and CApC-affected mice and were associated with the increased expression of gp130 and phospho-Stat3. Treatment with soluble gp130Fc significantly reduced the CApC. IL-6 trans-signaling in epithelial cells induced by macrophage-derived IL-6/sIL-6R alpha plays a crucial role in the development of CAC. PMID:20042582

Matsumoto, Satoshi; Hara, Taeko; Mitsuyama, Keiichi; Yamamoto, Mayuko; Tsuruta, Osamu; Sata, Michio; Scheller, Jürgen; Rose-John, Stefan; Kado, Sho-ichi; Takada, Toshihiko

2010-02-01

41

The influence of elastin-like recombinant polymer on the self-renewing potential of a 3D tissue equivalent derived from human lamina propria fibroblasts and oral epithelial cells.  

PubMed

Three-dimensional epithelial tissue equivalents tend to lose their self-renewing potential progressively during culture as their epithelial cells lose their proliferative capacity with time. Even though the tissue engineered construct can mimic the native tissue well, it rapidly degrades after implantation due to the insufficient number of proliferating cells in the equivalent. In the present study we demonstrate for the first time that the use of an elastin-like recombinant polymer (ELR) engineered to contain the cell adhesion peptide RGD can result in a 3D tissue equivalent with high self-renewing potential, containing as many proliferative cells as the native tissue itself. The 3D tissue equivalent was reconstructed by the coculture of human lamina propria fibroblasts and oral epithelial cells in the nanofibrous ELR-collagen scaffold. Histological, immunohistological and transmission electron microscopic analyses of this oral mucosa equivalent demonstrated the expression of markers characteristic of epithelial proliferation (Ki67) and differentiation (keratin 13), and also the presence of a pluristratified epithelium and an ultrastructurally well-organized basement membrane expressing laminin 332. The synthesis of new extracellular matrix by the fibroblasts was also demonstrated. The scaffold proposed here presents great potential for tissue engineering applications, and also for studies of epithelial proliferation, and epithelial disorders including carcinogenesis. PMID:21592566

Kinikoglu, Beste; Rodríguez-Cabello, José Carlos; Damour, Odile; Hasirci, Vasif

2011-09-01

42

Regulation of life and death in lamina propria T cells  

Microsoft Academic Search

T cells are essential to initiation, amplification, and regulation of an immune response. This response is terminated when T cells undergo apoptosis, a physiological process of cell death triggered by various mechanisms and regulated by signaling pathways leading to enzymatic degradation of chromatin. An effective immune response depends on the proper balance between proliferation and death of activated T cells.

Alan D Levine; Claudio Fiocchi

2001-01-01

43

CTLA-4 promotes Foxp3 induction and regulatory T cell accumulation in the intestinal lamina propria  

PubMed Central

Thymic induction of CD4+Foxp3+ regulatory T (Treg) cells relies on CD28 costimulation and high-affinity T-cell receptor (TCR) signals, whereas Foxp3 (forkhead box P3) induction on activated peripheral CD4+ T cells is inhibited by these signals. Accordingly, the inhibitory molecule CTLA-4 (cytotoxic T-lymphocyte antigen 4) promoted, but was not essential for CD4+ T-cell Foxp3 induction in vitro. We show that CTLA-4-deficient cells are equivalent to wild-type cells in the thymic induction of Foxp3 and maintenance of Foxp3 populations in the spleen and mesenteric lymph nodes, but their accumulation in the colon, where Treg cells specific for commensal bacteria accumulate, is impaired. In a T cell–transfer model of colitis, the two known CTLA-4 ligands, B7-1 and B7-2, had largely redundant roles in inducing inflammation and promoting Treg cell function. However, B7-2 proved more efficient than B7-1 in inducing Foxp3 in vitro and in vivo. Our data reveal an unappreciated role for CTLA-4 in establishing the Foxp3+ compartment in the intestine.

Barnes, M J; Griseri, T; Johnson, A M F; Young, W; Powrie, F; Izcue, A

2013-01-01

44

Securing the immune tightrope: mononuclear phagocytes in the intestinal lamina propria  

Microsoft Academic Search

The intestinal landscape comprises the host's own tissue and immune cells, as well as a diverse intestinal microbiota. Intricate regulatory mechanisms have evolved to maintain peaceful coexistence at this site, the breakdown of which can result in devastating inflammatory bowel diseases (IBDs). Mononuclear phagocytes promote both innate and adaptive immune responses in the gut and, as such, are essential for

Chen Varol; Ehud Zigmond; Steffen Jung

2010-01-01

45

Infliximab treatment induces apoptosis of lamina propria T lymphocytes in Crohn's disease  

PubMed Central

Background and aims: Treatment with infliximab induces remission in about 70% of patients with steroid refractory Crohn's disease. Because Crohn's disease is considered to be mediated by uncontrolled activation of mucosal T lymphocytes, we hypothesised that infliximab could induce apoptosis of T lymphocytes. Methods: Induction of apoptosis in vivo was studied in 10 patients with therapy refractory Crohn's disease. In vitro, resting or stimulated Jurkat T cells were incubated with infliximab. Results: Infusion of infliximab (5 mg/kg) in steroid refractory patients with Crohn's disease induced a clinical response in 9/10 patients but did not influence expression of activation markers, homing receptors, memory cells, Fas expression, or Bax/Bcl-2 expression on peripheral blood T lymphocytes. In contrast, a significant increase in CD3 and TUNEL positive cells within colonic biopsies was detected 24 hours after infusion of infliximab, suggesting that infliximab stimulates apoptosis of activated T lymphocytes but not of resting T cells. To test this hypothesis, the effects of infliximab on Jurkat T cells were investigated. We observed that infliximab induced apoptosis and an increase in the Bax/Bcl-2 ratio of CD3/CD28 stimulated Jurkat T cells but not of unstimulated Jurkat cells. Conclusions: Our data indicate that infliximab treatment causes a rapid and specific increase in apoptosis of T lymphocytes in the gut mucosa. These findings may explain the rapid and sustained therapeutic effects of infliximab in Crohn's disease.

ten Hove, T; van Montfrans, C; Peppelenbosch, M P; van Deventer, S J H

2002-01-01

46

The intriguing plant nuclear lamina  

PubMed Central

The nuclear lamina is a complex protein mesh attached to the inner nuclear membrane (INM), which is also associated with nuclear pore complexes. It provides mechanical support to the nucleus and nuclear envelope, and as well as facilitating the connection of the nucleoskeleton to the cytoskeleton, it is also involved in chromatin organization, gene regulation, and signaling. In metazoans, the nuclear lamina consists of a polymeric layer of lamins and other interacting proteins responsible for its association with the INM and chromatin. In plants, field emission scanning electron microscopy of nuclei, and thin section transmission electron microscopy of isolated nucleoskeletons, reveals the lamina to have a similar structure to that of metazoans. Moreover, although plants lack lamin genes and the genes encoding most lamin-binding proteins, the main functions of the lamina are fulfilled in plants. Hence, it would appear that the plant lamina is not based on lamins and that other proteins substitute for lamins in plant cells. The nuclear matrix constituent proteins are the best characterized structural proteins in the plant lamina. Although these proteins do not display strong sequence similarity to lamins, their predicted secondary structure and sub-nuclear distribution, as well as their influence on nuclear size and shape, and on heterochromatin organization, suggest they could be functional lamin analogs. In this review we shall summarize what is currently known about the organization and composition of the plant nuclear lamina and its interacting complexes, and we will discuss the activity of this structure in the plant cell and its nucleus.

Ciska, Malgorzata; Moreno Diaz de la Espina, Susana

2014-01-01

47

The intriguing plant nuclear lamina.  

PubMed

The nuclear lamina is a complex protein mesh attached to the inner nuclear membrane (INM), which is also associated with nuclear pore complexes. It provides mechanical support to the nucleus and nuclear envelope, and as well as facilitating the connection of the nucleoskeleton to the cytoskeleton, it is also involved in chromatin organization, gene regulation, and signaling. In metazoans, the nuclear lamina consists of a polymeric layer of lamins and other interacting proteins responsible for its association with the INM and chromatin. In plants, field emission scanning electron microscopy of nuclei, and thin section transmission electron microscopy of isolated nucleoskeletons, reveals the lamina to have a similar structure to that of metazoans. Moreover, although plants lack lamin genes and the genes encoding most lamin-binding proteins, the main functions of the lamina are fulfilled in plants. Hence, it would appear that the plant lamina is not based on lamins and that other proteins substitute for lamins in plant cells. The nuclear matrix constituent proteins are the best characterized structural proteins in the plant lamina. Although these proteins do not display strong sequence similarity to lamins, their predicted secondary structure and sub-nuclear distribution, as well as their influence on nuclear size and shape, and on heterochromatin organization, suggest they could be functional lamin analogs. In this review we shall summarize what is currently known about the organization and composition of the plant nuclear lamina and its interacting complexes, and we will discuss the activity of this structure in the plant cell and its nucleus. PMID:24808902

Ciska, Malgorzata; Moreno Díaz de la Espina, Susana

2014-01-01

48

The Organum vasculosum laminae terminalis  

Microsoft Academic Search

The Organum vasculosum laminae terminalis (OVLT) of the duck is lined innerly by specialized ependymal cells (tanycytes) and outwardly by a well-developed superficial vascular network, the capillaries of which often show a fenestrated endothelium. The OVLT also includes glial cells, internal non-fenestrated capillaries, bundles of fine nerve fibers and three groups of axonal swellings. One type contains granulations of 1000–1400

O. Bosler; I. Assenmacher; A. Calas

1977-01-01

49

Involvement of M cells in the bacterial invasion of Peyer's patches: a common mechanism shared by Yersinia enterocolitica and other enteroinvasive bacteria.  

PubMed Central

Recent evidence indicates that ileal Peyer's patches represent the main infection route for Yersinia enterocolitica. In this study transmission and scanning electron microscopy have shown that only a small fraction of bacteria present in the lumen adhere to the follicle-associated murine epithelium with no discernible preference for either M or absorptive cells. Yersiniae attached to M cells are phagocytosed and transported from the lumen into the lamina propria. No invasion of columnar absorptive cells was observed. These data, in combination with recently published reports, indicate that the involvement of M cells is a common step in bacterial invasion of Peyer's patches. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Grutzkau, A; Hanski, C; Hahn, H; Riecken, E O

1990-01-01

50

Investigating deeper: muscularis propria to natural orifice transluminal endoscopic surgery.  

PubMed

Submucosal endoscopy with a mucosal flap (SEMF) safety valve technique is a global concept in which the submucosa is a free working space for endoscopic interventions. A purposefully created intramural space provides an endoscopic access route to the deeper layers and into the extraluminal cavities. The mucosa overlying the intramural space is protective, reducing contamination during natural orifice transluminal endoscopic surgery (NOTES) procedures and providing a sealant flap to repair the entry point and the submucosal space. In addition to NOTES, SEMF enables endoscopic achalasia myotomy, histologic analysis of the muscularis propria, and submucosal tumor removal. PMID:24679237

Sumiyama, Kazuki; Gostout, Christopher J; Tajiri, Hisao

2014-04-01

51

Anatomically motivated modeling of cortical laminae.  

PubMed

Improvements in the spatial resolution of structural and functional MRI are beginning to enable analysis of intracortical structures such as heavily myelinated layers in 3D, a prerequisite for in-vivo parcellation of individual human brains. This parcellation can only be performed precisely if the profiles used in cortical analysis are anatomically meaningful. Profiles are often constructed as traverses that are perpendicular to computed laminae. In this case they are fully determined by these laminae. The aim of this study is to evaluate models for cortical laminae used so far and to establish a new model. Methods to model the laminae used so far include constructing laminae that keep a constant distance to the cortical boundaries, so-called equidistant laminae. Another way is to compute equipotentials between the cortical boundary surfaces with the Laplace equation. The Laplace profiles resulting from the gradients to the equipotentials were often-used because of their nice mathematical properties. However, the equipotentials these Laplacian profiles are constructed from and the equidistant laminae do not follow the anatomical layers observed using high resolution MRI of cadaver brain. To remedy this problem, we introduce a novel equi-volume model that derives from work by Bok (1929). He argued that cortical segments preserve their volume, while layer thickness changes to compensate cortical folding. We incorporate this preservation of volume in our new equi-volume model to generate a three-dimensional well-adapted undistorted coordinate system of the cortex. When defined by this well-adapted coordinate system, cortical depth is anatomically meaningful. We compare isocontours from these cortical depth values to locations of myelinated bands on high-resolution ex-vivo and in-vivo three-dimensional MR images. A similar comparison was performed with equipotentials computed with the Laplace equation and with equidistant isocontours. A quantitative evaluation of the equi-volume model using measured image intensities confirms that it provides a much better fit to observed cortical layering. PMID:23603284

Waehnert, M D; Dinse, J; Weiss, M; Streicher, M N; Waehnert, P; Geyer, S; Turner, R; Bazin, P-L

2014-06-01

52

Specifying peripheral heterochromatin during nuclear lamina reassembly.  

PubMed

A conserved organizational feature of eukaryotic nuclei is the peripheral heterochromatin compartment, which provides a protected area for epigenetically silent genes and gene-poor DNA. In metazoan cells this compartment is associated with the nuclear lamina, the protein meshwork at the inner edge of the nucleus. Heterochromatin-nuclear lamina interactions promote epigenetic gene silencing, which may drive many normal and diseased biological processes. We recently obtained evidence that a previously unstudied human protein, PRR14, participates in the tethering of heterochromatin to the inner nuclear periphery. PRR14 associates with the nuclear lamina and attaches to heterochromatin through its binding partner, heterochromatin protein 1 (HP1). After disassembly early in mitosis, PRR14 reassembles in two steps, first binding to anaphase chromosomes through HP1, followed by association with the nuclear lamina in telophase. PRR14 may thereby play a role in specifying HP1-bound heterochromatin for reattachment to the nuclear lamina at mitotic exit. Here we review the relevant literature, summarize our initial work, and provide additional comments and findings. PMID:24637393

Poleshko, Andrey; Katz, Richard A

2014-01-01

53

Nonlinear Elastic Behavior of Unidirectional Composite Laminae  

Microsoft Academic Search

Complementary elastic energy density is used to derive a stress-strain relation, which is linear in uniaxial loadings in the longitudinal and trans verse directions, but nonlinear in shear. In the case of composite laminae under plane stress, one additional fourth-order constant is introduced. Comparison is shown between the present theory and experimental data on off-axis tests.

Hong T. Hahn; Stephen W. Tsai

1973-01-01

54

Making Thin Laminae Of Frozen Alloy Slurries  

NASA Technical Reports Server (NTRS)

In new technique, primary objective to develop method to distribute uniformly-thin powder-metal-alloy layers between alternate fiber layers prior to consolidation. Involves use of sheets of frozen alloy powder. These laminae, interspersed with fiber mats, used to make metal/fiber composites. In addition to aerospace applications, this technique, appropriately modified, has potential in the manufacture of future automobile engines or components including molded ceramics.

Ghosh, A. K.; Holmes, L. M.; Houston, R. B.; Ecer, G. M.

1992-01-01

55

Inhibition of Intestinal Bacterial Translocation with Rifaximin Modulates Lamina propria Monocytic Cells Reactivity and Protects against Inflammation in a Rodent Model of Colitis  

Microsoft Academic Search

Background: A modification of the intestinal flora and an increased bacterial translocation is a common finding in patients with inflammatory bowel disease as well as in animal model of colitis. Rifaximin, a non-absorbable derivative of rifamycin, is an effective antibiotic that acts by inhibiting bacterial ribonucleic acid synthesis. Aims: In the present study, we investigated the effect of the administration

Stefano Fiorucci; Eleonora Distrutti; Andrea Mencarelli; Miriam Barbanti; Ernesto Palazzini; Antonio Morelli

2002-01-01

56

Initiation of teeth from the dental lamina in the ferret.  

PubMed

Mammalian tooth development is characterized by formation of primary teeth that belong to different tooth classes and are later replaced by a single set of permanent teeth. The first primary teeth are initiated from the primary dental lamina, and the replacement teeth from the successional dental lamina at the lingual side of the primary teeth. An interdental lamina connects the primary tooth germs together. Most mammalian tooth development research is done on mouse, which does not have teeth in all tooth classes, does not replace its teeth, and does not develop an interdental lamina. We have used the ferret (Mustela putorius furo) as a model animal to elucidate the morphological changes and gene expression during the development of the interdental lamina and the initiation of primary teeth. In addition we have analyzed cell-cell signaling taking place in the interdental lamina as well as in the successional lamina during tooth replacement. By 3D reconstructions of serial histological sections we observed that the morphogenesis of the interdental lamina and the primary teeth are intimately linked. Expression of Pitx2 and Foxi3 in the interdental lamina indicates that it has odontogenic identity, and there is active signaling taking place in the interdental lamina. Bmp4 is coexpressed with the stem cell factor Sox2 at its lingual aspect suggesting that the interdental lamina may retain competence for tooth initiation. We show that when tooth replacement is initiated there is Wnt pathway activity in the budding successional lamina and adjacent mesenchyme but no active Fgf or Eda signaling. Genes associated with human tooth replacement phenotypes, including Runx2 and Il11r?, are mostly expressed in the mesenchyme around the successional lamina in the ferret. Our results highlight the importance of the dental lamina in the mammalian tooth development during the initiation of both primary and replacement teeth. PMID:24393477

Jussila, Maria; Crespo Yanez, Xenia; Thesleff, Irma

2014-01-01

57

The adsorptive properties of the tunica vaginalis propria of the testis  

Microsoft Academic Search

Absorptive properties of the testicular tunica vaginalis propria are distinctly manifested only in case of true and colloidal solutions. Morphological experiments have clearly demonstrated that crystalloids are absorbed both by blood and lymphatic vessels of this serous membrane, while colloids only by its lymphatic vessels. In both cases the outstanding role is that of the vascular bed of the parietal

E. B. Khaisman; V. N. Chernigovsky

1957-01-01

58

Human fetal lung fibroblasts promote invasion of extracellular matrix by normal human tracheobronchial epithelial cells in vitro: a model of early airway gland development.  

PubMed

Epithelial invasion of extracellular matrix (ECM) is important during lung development and the pathogenesis of bronchogenic neoplasms. Airway submucosal gland development begins when clusters of surface epithelial cells invade the lamina propria between the tenth and thirtieth weeks of fetal life. The factors regulating this transient normal invasive behavior are unknown. We observed that normal human tracheobronchial epithelial (HTBE) cells from adult necropsy specimens penetrate collagen matrices when co-cultured with human fetal lung fibroblasts (HFLF). Invading clusters of epithelial cells resembled primordial glands, forming tubular structures and undergoing dichotomous branching. Using 48 different tracheobronchial specimens, we compared paired cultures of HTBE cells without (control) and with HFLF co-culture. Fixed, vertically sectioned culture substrates were examined, and invaginated epithelial cell clusters as well as total invading HTBE cells were counted. The co-cultured condition resulted in significantly more epithelial invaginations per two sections (4 +/- 1 versus 22 +/- 3, P < 0.0005) and more invading HTBE cells per two sections (31 +/- 9 versus 194 +/- 27, P < 0.0005) than controls. Epithelial invasion was noted by 36 h in culture and was greatest at HTBE cell/HFLF ratios near 1 and HFLF passages between 10 and 16. Epithelial cells co-cultured with a fibroblast cell line derived from the adult bronchiole showed no increase in ECM invasion compared with controls. These results demonstrate that fetal mesenchymal cells are capable of promoting invasive behavior in mature epithelial cells in vitro. Given the fibroblast type and passage specificity, this model should prove useful for investigating the cellular and molecular regulation of epithelial ECM invasion. PMID:8417759

Infeld, M D; Brennan, J A; Davis, P B

1993-01-01

59

Strength properties of glued laminated timber made from edge-glued laminae I: strength properties of edge-glued karamatsu ( Larix kaempferi ) laminae  

Microsoft Academic Search

The object of this study was to investigate the strength properties of edge-glued laminae and to propose a suitable grading\\u000a method based on the lamina modulus of elasticity (MOE). Edge-glued laminae composed of lumber with similar MOEs (uniform laminae)\\u000a and edge-glued laminae produced by randomly gluing lumber independent of MOE (random laminae) were made from karamatsu (Larix kaempferi) lumber having

Kiyohiko Fujimoto; Yasushi Hiramatsu; Atsushi Miyatake; Kenta Shindo; Masahiko Karube; Masaki Harada; Seiichiro Ukyo

2010-01-01

60

Temperature dependent nonlinear metal matrix laminae behavior  

NASA Technical Reports Server (NTRS)

An analytical method is described for computing the nonlinear thermal and mechanical response of laminated plates. The material model focuses upon the behavior of metal matrix materials by relating the nonlinear composite response to plasticity effects in the matrix. The foundation of the analysis is the unidirectional material model which is used to compute the instantaneous properties of the lamina based upon the properties of the fibers and matrix. The unidirectional model assumes that the fibers properties are constant with temperature and assumes that the matrix can be modelled as a temperature dependent, bilinear, kinematically hardening material. An incremental approach is used to compute average stresses in the fibers and matrix caused by arbitrary mechanical and thermal loads. The layer model is incorporated in an incremental laminated plate theory to compute the nonlinear response of laminated metal matrix composites of general orientation and stacking sequence. The report includes comparisons of the method with other analytical approaches and compares theoretical calculations with measured experimental material behavior. A section is included which describes the limitations of the material model.

Barrett, D. J.; Buesking, K. W.

1986-01-01

61

Reorganization of the nuclear lamina and cytoskeleton in adipogenesis  

Microsoft Academic Search

A thorough understanding of fat cell biology is necessary to counter the epidemic of obesity. Although molecular pathways\\u000a governing adipogenesis are well delineated, the structure of the nuclear lamina and nuclear-cytoskeleton junction in this\\u000a process are not. The identification of the ‘linker of nucleus and cytoskeleton’ (LINC) complex made us consider a role for\\u000a the nuclear lamina in adipose conversion.

Valerie L. R. M. Verstraeten; Johan Renes; Frans C. S. Ramaekers; Miriam Kamps; Helma J. Kuijpers; Fons Verheyen; Martin Wabitsch; Peter M. Steijlen; Maurice A. M. van Steensel; Jos L. V. Broers

2011-01-01

62

PEAPOD regulates lamina size and curvature in Arabidopsis  

PubMed Central

Although a complex pattern of interspersed cell proliferation and cell differentiation is known to occur during leaf blade development in eudicot plants, the genetic mechanisms coordinating this growth are unclear. In Arabidopsis, deletion of the PEAPOD (PPD) locus increases leaf lamina size and results in dome-shaped rather than flat leaves. Siliques are also altered in shape because of extra lamina growth. The curvature of a ?ppd leaf reflects the difference between excess growth of the lamina and a limitation to the extension capacity of its perimeter. Excess lamina growth in ?ppd plants is due to a prolonged phase of dispersed meristematic cell (DMC) proliferation (for example, the meristemoid and procambium cells that form stomatal stem cells and vascular cells, respectively) during blade development. The PPD locus is composed of two homologous genes, PPD1 and PPD2, which encode plant-specific putative DNA-binding proteins. Overexpression of PPD reduces lamina size by promoting the early arrest of DMC proliferation during leaf and silique development. Therefore, by regulating the arrest of DMC proliferation, the PPD genes coordinate tissue growth, modulate lamina size, and limit curvature of the leaf blade. I propose a revised model of leaf development with two cell-cycle arrest fronts progressing from the tip to the base: the known primary front, which determines arrest of general cell proliferation, followed by a secondary front that involves PPD and arrests DMC division.

White, Derek W. R.

2006-01-01

63

Ozone laminae near the edge of the stratospheric polar vortex  

NASA Technical Reports Server (NTRS)

Analysis of ozonesonde data collected at high northern latitudes in winter and spring shows that laminae of enhanced and depleted ozone are associated with the polar vortex. In January and February, they are most common at all latitudes in the potential temperature range 370-430 K, but are abundant up to 500 K between 60 and 70 deg N. In March and April they occur most frequently northward of 75 deg N, and are abundant up to 520 K, whereas they are largely confined to the range 320-440 K at lower latitudes. Analysis of ozone lidar data obtained during AASE-1 depicts clearly the extrusion of laminae of enhanced ozone concentration from the polar regions in the altitude range 13-15 km. These extrusions form a class of laminae which transport ozone equatorward in the lowest levels of the stratosphere.

Reid, S. J.; Vaughan, Geraint

1994-01-01

64

Reorganization of the nuclear lamina and cytoskeleton in adipogenesis.  

PubMed

A thorough understanding of fat cell biology is necessary to counter the epidemic of obesity. Although molecular pathways governing adipogenesis are well delineated, the structure of the nuclear lamina and nuclear-cytoskeleton junction in this process are not. The identification of the 'linker of nucleus and cytoskeleton' (LINC) complex made us consider a role for the nuclear lamina in adipose conversion. We herein focused on the structure of the nuclear lamina and its coupling to the vimentin network, which forms a cage-like structure surrounding individual lipid droplets in mature adipocytes. Analysis of a mouse and human model system for fat cell differentiation showed fragmentation of the nuclear lamina and subsequent loss of lamins A, C, B1 and emerin at the nuclear rim, which coincides with reorganization of the nesprin-3/plectin/vimentin complex into a network lining lipid droplets. Upon 18 days of fat cell differentiation, the fraction of adipocytes expressing lamins A, C and B1 at the nuclear rim increased, though overall lamin A/C protein levels were low. Lamin B2 remained at the nuclear rim throughout fat cell differentiation. Light and electron microscopy of a subcutaneous adipose tissue specimen showed striking indentations of the nucleus by lipid droplets, suggestive for an increased plasticity of the nucleus due to profound reorganization of the cellular infrastructure. This dynamic reorganization of the nuclear lamina in adipogenesis is an important finding that may open up new venues for research in and treatment of obesity and nuclear lamina-associated lipodystrophy. PMID:21350821

Verstraeten, Valerie L R M; Renes, Johan; Ramaekers, Frans C S; Kamps, Miriam; Kuijpers, Helma J; Verheyen, Fons; Wabitsch, Martin; Steijlen, Peter M; van Steensel, Maurice A M; Broers, Jos L V

2011-03-01

65

Ultrasonographic thickening of the muscularis propria in feline small intestinal small cell T-cell lymphoma and inflammatory bowel disease.  

PubMed

Gastrointestinal lymphoma is the most common form of lymphoma in the cat. More recently, an ultrasonographic pattern associated with feline small cell T-cell gastrointestinal lymphoma has been recognized as a diffuse thickening of the muscularis propria of the small intestine. This pattern is also described with feline inflammatory bowel disease. To evaluate the similarities between the diseases, we quantified the thickness of the muscularis propria layer in the duodenum, jejunum and ileum of 14 cats affected by small cell T-cell lymphoma and inflammatory bowel disease (IBD) and 19 healthy cats. We found a significantly increased thickness of the muscularis propria in cats with lymphoma and IBD compared with healthy cats. The mean thickness of the muscularis propria in cats with lymphoma or IBD was twice the thickness of that of healthy cats, and was the major contributor to significant overall bowel wall thickening in the duodenum and jejunum. A muscularis to submucosa ratio >1 is indicative of an abnormal bowel segment. Colic lymph nodes in cats with lymphoma were increased in size compared with healthy cats. In cats with gastrointestinal lymphoma and histologic transmural infiltration of the small intestines, colic or jejunal lymph nodes were rounded, increased in size and hypoechoic. PMID:23900499

Daniaux, Lise A; Laurenson, Michele P; Marks, Stanley L; Moore, Peter F; Taylor, Sandra L; Chen, Rachel X; Zwingenberger, Allison L

2014-02-01

66

Substructure in an Epithelial Basal Lamina (Basement Membrane).  

National Technical Information Service (NTIS)

A well ordered grid structure is described in the basal lamina of the Aedes aegypti midgut epithelium. In sections parallel to the epithelial base, the grid structure is a series of dense lines intersecting at approximately right angles to one another. Th...

J. A. Terzakis

1967-01-01

67

Der Feinbau des Gefäßorgans der Lamina terminalis beim Kaninchen  

Microsoft Academic Search

The organum vasculosum laminae terminalis may be divided into two zones: the external zone borders on the cisterna praechiasmatica and contains numerous astrocytic processes; the internal zone contains many perikarya and bulges into the 3rd ventricle forming “bulbous protrusions”. The organ is characterized by a special vascular arrangement: At the boundary between the cisterna and the external zone a branch

A. Weindl; A. Schwink; R. Wetzstein

1967-01-01

68

Elastic and viscoelastic characterization of transversely isotropic composite laminae  

NASA Astrophysics Data System (ADS)

With the advent of "designed damping" in composite materials, and modern computer design tools, accurate three-dimensional material properties information is critically important. Further, design of advanced composite structures often requires knowledge of material properties over a range of temperatures. Conventional testing approaches for the determination of material properties present difficulties related to specimen preparation, fixturing and test apparatus. Consequently, engineers frequently make use of micromechanics generated properties. Unfortunately, micromechanics approaches do not usually account for manufacturing and temperature variations, which affect material properties. This research focuses on developing approaches to allow experimental characterization of elastic and viscoelastic properties of fiber reinforced composite laminae, over a range of temperatures. In addition to investigating the temperature dependence of the three-dimensional material properties, for the viscoelastic characterization, the effect of loading frequency is also addressed. A technique for the determination of the three-dimensional elastic coefficients of transversely isotropic laminae is developed, using a combination of laminate coefficient of thermal expansion (CTE) measurements and two elastic properties measured from a standard tensile test. The CTE measurements are conducted in a laboratory thermo mechanical analyzer (TMA), using samples of simple geometry. PEEK/IM7 laminae are used to verify this approach and the computed room temperature elastic properties are in good agreement with quoted elastic material properties measured by standard techniques. Viscoelastic material characterization is essential to designs that incorporate specified levels of damping, and to understand processing problems. This work also presents an approach to determine the three-dimensional viscoelastic properties of transversely isotropic fiber reinforced materials. The minimum number of independent coefficients for three-dimensional viscoelastic characterization of transversely isotropic laminae is investigated and a reduced set of material coefficients, that specify the constitutive relationships, is proposed. The experimental approach developed is based only on flexural measurements allowing complete characterization using a dynamic mechanical analyzer (DMA). To verify the approach, viscoelastic properties of PEEK/IM7 laminae and laminates are determined over ranges of temperature and frequency. The mechanics relations and experimental techniques developed in this work provide means for measuring the elastic and viscoelastic properties of fiber reinforced composites, and constitute a valuable contribution to the understanding of temperature and frequency dependence of these mechanical properties.

Melo, Jose Daniel Diniz

69

The human protein PRR14 tethers heterochromatin to the nuclear lamina during interphase and mitotic exit.  

PubMed

The nuclear lamina is a protein meshwork that lies under the inner nuclear membrane of metazoan cells. One function of the nuclear lamina is to organize heterochromatin at the inner nuclear periphery. However, very little is known about how heterochromatin attaches to the nuclear lamina and how such attachments are restored at mitotic exit. Here, we show that a previously unstudied human protein, PRR14, functions to tether heterochromatin to the nuclear periphery during interphase, through associations with heterochromatin protein 1 (HP1) and the nuclear lamina. During early mitosis, PRR14 is released from the nuclear lamina and chromatin and remains soluble. Strikingly, at the onset of anaphase, PRR14 is incorporated rapidly into chromatin through HP1 binding. Finally, in telophase, PRR14 relocalizes to the reforming nuclear lamina. This stepwise reassembly of PRR14 suggests a function in the selection of HP1-bound heterochromatin for reattachment to the nuclear lamina as cells exit mitosis. PMID:24209742

Poleshko, Andrey; Mansfield, Katelyn M; Burlingame, Caroline C; Andrake, Mark D; Shah, Neil R; Katz, Richard A

2013-10-31

70

Subfrontal endoscopic fenestration of lamina terminalis: an anatomical study.  

PubMed

Different surgical approaches to and through the lamina terminalis (LT) have been proposed to treat pathologies of the anterior third ventricle. Moreover, the opening of the LT is a standard adjunct in ruptured aneurysm surgery. However, the endoscopic anatomy and approach to the LT have not been extensively described. In the following study we performed an endoscopic subfrontal approach to the LT on 10 human cadaveric specimens through a supraorbital minicraniotomy. We discuss the endoscopic anatomy of the LT region and its fenestration through such an approach. The clinical potential use of this alternative third ventriculostomy is also pointed out. PMID:19061140

Spena, G; Fasel, J; Tribolet, N de; Radovanovic, I

2008-12-01

71

Extracting paleoclimate signals from sediment laminae: An automated 2-D image processing method  

NASA Astrophysics Data System (ADS)

Lake sediments commonly contain laminations and the occurrence and quantitative attributes of these microstrata contain signals of their depositional environment, limnological conditions, and past climate. However, the identification and measurement of laminae and their attributes remains a largely semi-manual process that is tedious, labor intensive, but subject to human error. Here, we present a method to automatically measure and accurately extract lamina properties from sediment core images. This method is comprised of four major components: (1) image enhancement that includes noise reduction and contrast enhancement to improve signal-to-background ratio and resolution of laminae; (2) identification of 1-D laminae for a user-chosen area in an image; (3) laminae connectivity analyses on the 1-D laminae to obtain a lamina stratigraphy; and (4) extraction and retrieval of the primary and derived lamination stratigraphic data. Sediment core images from Lake Hitchcock and Lake Bosumtwi were used for algorithm development and testing. Our experiments show a complete match between laminae produced by the software and manual process for images from Lake Hitchcock. Quantitative comparisons reveal an insignificant discrepancy in the number of laminae identified automatically by the software and manually by researchers, and in over 90% of the cases the position mismatch of individual laminae is less than one pixel between the software and the manual method for the experimental images from Lake Bosumtwi.

Gan, Stoney Q.; Scholz, Christopher A.

2013-03-01

72

A conserved transcriptional network regulates lamina development in the Drosophila visual system.  

PubMed

The visual system of insects is a multilayered structure composed externally by the compound eye and internally by the three ganglia of the optic lobe: lamina, medulla and the lobula complex. The differentiation of lamina neurons depends heavily on Hedgehog (Hh) signaling, which is delivered by the incoming photoreceptor axons, and occurs in a wave-like fashion. Despite the primary role of lamina neurons in visual perception, it is still unclear how these neurons are specified from neuroepithelial (NE) progenitors. Here we show that a homothorax (hth)-eyes absent (eya)-sine oculis (so)-dachshund (dac) gene regulatory cassette is involved in this specification. Lamina neurons differentiate from NE progenitors that express hth, eya and so. One of the first events in the differentiation of lamina neurons is the upregulation of dac expression in response to Hh signaling. We show that this dac upregulation, which marks the transition from NE progenitors into lamina precursors, also requires Eya/So, the expression of which is locked in by mutual feedback. dac expression is crucial for lamina differentiation because it ensures repression of hth, a negative regulator of single-minded, and thus dac allows further lamina neuron differentiation. Therefore, the specification of lamina neurons is controlled by coupling the cell-autonomous hth-eya-so-dac regulatory cassette to Hh signaling. PMID:24924198

Piñeiro, Cristina; Lopes, Carla S; Casares, Fernando

2014-07-01

73

Basal lamina formation on thyroid epithelia in separated follicles in suspension culture  

PubMed Central

When thyroid follicles are isolated by collagenase treatment of minced thyroid lobes, the basal lamina around each follicle is removed. The basal lamina does not reform when follicles are cultured in suspension in Coon's modified Ham's F-12 medium containing, in addition, 0.5% calf serum, insulin, transferrin, and thyrotropin. We have added acid soluble collagen and/or laminin to see if they would result in the formation of a basal lamina. An extended basal lamina did not form when follicles were embedded in a gel formed from acid-soluble rat tendon collagen or from calf skin collagen when added at a concentration of 100 micrograms collagen/ml. However, laminin at a concentration of 5.1 micrograms/ml gave rise to short segments of a basal lamina within 30 min. At longer time intervals, the segments lengthened and covered the base of many cells, and were continuous across the gap between cells and across the mouth of a coated pit. Not all basal surfaces were covered, and no exposed apical surfaces with microvilli had a basal lamina. There was no obvious difference in the appearance of the basal lamina if collagen was added in addition to laminin, but collagen, in contact with the plasma membrane when added alone, was lifted off the membrane in the presence of the basal lamina. The basal lamina appeared denser if formed in the presence of 5% serum instead of 0.5%.

1982-01-01

74

Effects of Modification in the Laminin-10 Basal Lamina on Prostate Cancer Invasion.  

National Technical Information Service (NTIS)

In order for prostate cancer to metastasize it must invade through a laminin-511 rich barrier. We have previously shown that the matrix metalloprotease MTI-MMP which is expressed in prostate cancer but not in normal prostate tissue cleaves the laminin alp...

E. L. Bair S. C. Pawar

2007-01-01

75

Basal lamina structural alterations in human asymmetric aneurismatic aorta.  

PubMed

Basal lamina (BL) is a crucial mechanical and functional component of blood vessels, constituting a sensor of extracellular microenvironment for endothelial cells and pericytes. Recently, an abnormality in the process of matrix microfibrillar component remodeling has been advocated as a mechanism involved in the development of aortic dilation. We focused our attention on BL composition and organization and studied some of the main components of the Extracellular Matrix such as Tenascin, Laminins, Fibronectin, type I, III and IV Collagens. We used surgical fragments from 27 patients, submitted to operation because of aortic root aneurysm and 5 normal aortic wall specimens from heart donors without any evidence for aneurysmal or atherosclerotic diseases of the aorta. Two samples of aortic wall were harvested from each patient, proximal to the sinotubular junction at the aortic convexity and concavity. Each specimen was processed both for immunohistochemical examination and molecular biology study. We compared the convexity of each aortic sample with the concavity of the same vessel, and both of them with the control samples. The synthesis of mRNA and the levels of each protein were assessed, respectively, by RT-PCR and Western Blot analysis. Immunohistochemistry elucidated the organization of BL, whose composition was revealed by molecular biology. All pathological samples showed a wall thinner than normal ones. Basal lamina of the aortic wall evidentiated important changes in the tridimensional arrangement of its major components which lost their regular arrangement in pathological specimens. Collagen I, Laminin alpha2 chain and Fibronectin amounts decreased in pathological samples, while type IV Collagen and Tenascin synthesis increased. Consistently with the common macroscopic observation that ascending aorta dilations tend to expand asymmetrically, with prevalent involvement of the vessel convexity and relative sparing of the concavity, Collagen type IV is more evident in the concavity and Tenascin in the convexity. PMID:16377578

Cotrufo, M; De Santo, L; Della Corte, A; Di Meglio, F; Guerra, G; Quarto, C; Vitale, S; Castaldo, C; Montagnani, S

2005-01-01

76

Identification of some components of basal lamina of avian ovarian follicle.  

PubMed

Experiments were conducted to identify components of the basal lamina of the ovarian follicle. Pure and intact basal lamina was isolated from preovulatory follicles of the chicken ovary. Some components of the basal lamina could be solubilized with guanidine-HCl (designated Fraction 1) and remaining components with beta-mercaptomethanol containing guanidine-HCl (designated Fraction 2). With Western blot analysis, monoclonal and polyclonal antibodies raised against avian, mammalian, and human proteins recognized proteins in Fractions 1 and 2 of solubilized basal lamina. Thus, antibodies raised against extracellular matrix proteins, laminin, fibronectin, entactin or nidogen, tenascin, heparan sulfate proteoglycan, osteonectin, and Type IV collagen reacted positively with basal lamina proteins. Antibodies raised against the growth factors; epidermal growth factor; acidic and basic fibroblast growth factors; platelet-derived growth factor-AA; transforming growth factor-alpha; transforming growth factor-beta1, -beta2, -beta3, and -beta5; and insulin-like growth factor-I and -II cross-reacted with basal lamina proteins. Similarly, antibodies raised against insulin-like growth factor-binding proteins-2, -3, -4, -5, -6, and -7 cross-reacted with basal lamina proteins. In addition, antibodies generated against matrix metalloproteinases-1, -2, -3, -4, -8, -9, and -13 reacted positively with basal lamina proteins. Furthermore, antibodies produced against tissue inhibitors of matrix metalloproteinases-1, -2, -3, and -4 also reacted positively with basal lamina proteins. Moreover, interleukin-3, granulocyte macrophage-colony-stimulating factor, interferon-gamma antibodies recognized proteins in basal lamina. These observations are consistent with the view that the basal lamina of avian ovarian follicle is a store or source of biologically active molecules, namely growth factors, growth factor-binding proteins, cytokines, matrix metalloproteinases, and their tissue inhibitors. The growth factors could exert major effects on ovarian cell behavior and function, and the enzymes could participate in tissue remodeling during follicular development. PMID:10780659

Asem, E K; Stingley-Salazar, S R; Robinson, J P; Turek, J J

2000-04-01

77

Investigating Invasives  

ERIC Educational Resources Information Center

Invasive species, commonly known as "invasives," are nonnative plants, animals, and microbes that completely take over and change an established ecosystem. The consequences of invasives' spread are significant. In fact, many of the species that appear on the Endangered Species list are threatened by invasives. Therefore, the topic of invasive

Lightbody, Mary

2008-01-01

78

Differential effects of the cannabinoid receptor agonist, WIN 55,212-2, on lamina I and lamina V spinal trigeminal nucleus caudalis neurons  

PubMed Central

Direct application of cannabinoids to the medullary dorsal horn (MDH) inhibits lamina V nociceptive neurons. The present study compared the effect of the cannabinoid receptor agonist, WIN 55,212-2 (WIN-2) on the activity of lamina I and lamina V MDH neurons using extracellular single unit recording in anesthetized rats. Activity evoked by a contact thermode was measured before and after local application of WIN-2 (0.5-2.0 ?g/?l) to the brainstem. Fast and slow heat ramps were used to differentiate between activity evoked primarily by A-delta and C primary afferent fibers, respectively. In lamina V neurons, WIN-2 produced a concentration dependent decrease in activity evoked by both fast and slow heat, reaching significance at 1.0 ?g/?l. In lamina I neurons, WIN-2 administration inhibited slow heat evoked activity beginning at 1.0 ?g/?l but had no significant effect on fast heat evoked activity, even at the highest concentration (2.0 ?g/?l). In separate experiments, the effect of intrathecal administration of WIN-2 to the MDH on head withdrawal latencies elicited by fast and slow heat ramps applied to the whisker pad was assessed in lightly anesthetized rats. Head withdrawal latencies elicited by slow but not fast heat stimulation were increased by WIN-2. Taken together, these results emphasize the importance of lamina I neurons in the control of a nociceptive heat-evoked reflex.

Ogawa, Akiko; Meng, Ian D.

2009-01-01

79

Phenotypes of the ovarian follicular basal lamina predict developmental competence of oocytes  

PubMed Central

BACKGROUND The ovarian follicular basal lamina underlies the epithelial membrana granulosa and maintains the avascular intra-follicular compartment. Additional layers of basal lamina occur in a number of pathologies, including pili annulati and diabetes. We previously found additional layers of follicular basal lamina in a significant percentage of healthy bovine follicles. We wished to determine if this phenomenon existed in humans, and if it was related to oocyte function in the bovine. METHODS AND RESULTS We examined follicles from human ovaries (n = 18) by electron microscopy and found that many follicles had additional layers of basal lamina. Oocytes (n = 222) from bovine follicles with normal or unusual basal laminas were isolated and their ability to undergo in vitro maturation, fertilization and culture to blastocyst was compared. Healthy bovine follicles with a single layer of basal lamina had oocytes with significantly (P < 0.01) greater developmental competence than healthy follicles with additional layers of follicular basal lamina (65% versus 28%). CONCLUSIONS These findings provide direct evidence that the phenotype of the follicular basal lamina is related to oocyte competence.

Irving-Rodgers, Helen F.; Morris, Stephanie; Collett, Rachael A.; Peura, Teija T.; Davy, Margaret; Thompson, Jeremy G.; Mason, Helen D.; Rodgers, Raymond J.

2009-01-01

80

A Study of Ozone Laminae Using Diabatic Trajectories, Contour Advection and Photochemical Trajectory Model Simulations  

Microsoft Academic Search

In this paper, we show that the rate of ozone loss in both polar and mid-latitudes, derived from ozonesonde and satellite data, has almost the same vertical distribution (although opposite sense) to that of ozone laminae abundance. Ozone laminae appear in the lower stratosphere soon after the polar vortex is established in autumn, increase in number throughout the winter and

S. J. Reid; M. Rex; P. Von Der Gathen; I. Fløisand; F. Stordal; G. D. Carver; A. Beck; E. Reimer; R. Krüger-Carstensen; L. L. De Haan; G. Braathen; V. Dorokhov; H. Fast; E. Kyrö; M. Gil; Z. Lityñska; M. Molyneux; G. Murphy; F. O'Connor; F. Ravegnani; C. Varotsos; J. Wenger; C. Zerefos

1998-01-01

81

The hydraulic conductance of the angiosperm leaf lamina: a comparison of three measurement methods  

Microsoft Academic Search

A comparison was made of three methods for meas- uring the leaf lamina hydraulic conductance (Klamina) for detached mature leaves of six woody temperate angiosperm species. The high-pressure method, the evaporative flux method and the vacuum pump method involve, respectively, pushing, evaporating and pulling water out of the lamina while determining the flow rate into the petiole and the water

Lawren Sack; Peter J. Melcher; Maciej A. Zwieniecki; N. Michele Holbrook

2010-01-01

82

A nomenclature for vertebral laminae in sauropods and other saurischian dinosaurs  

Microsoft Academic Search

The vertebrae of sauropods are characterized by numerous bony struts that connect the costovertebral and intervertebral articulations, centrum, and neural spine of the presacral, sacral, and anterior caudal vertebrae. A nomenclature for sauropod vertebral laminae is proposed that: 1) utilizes the morphological landmarks connected by the laminae (rather than their spatial orientation); and 2) provides the same name for serial

Jeffrey A. Wilson

1999-01-01

83

Contributions of the 12 neuron classes in the fly lamina to motion vision.  

PubMed

Motion detection is a fundamental neural computation performed by many sensory systems. In the fly, local motion computation is thought to occur within the first two layers of the visual system, the lamina and medulla. We constructed specific genetic driver lines for each of the 12 neuron classes in the lamina. We then depolarized and hyperpolarized each neuron type and quantified fly behavioral responses to a diverse set of motion stimuli. We found that only a small number of lamina output neurons are essential for motion detection, while most neurons serve to sculpt and enhance these feedforward pathways. Two classes of feedback neurons (C2 and C3), and lamina output neurons (L2 and L4), are required for normal detection of directional motion stimuli. Our results reveal a prominent role for feedback and lateral interactions in motion processing and demonstrate that motion-dependent behaviors rely on contributions from nearly all lamina neuron classes. PMID:23849200

Tuthill, John C; Nern, Aljoscha; Holtz, Stephen L; Rubin, Gerald M; Reiser, Michael B

2013-07-10

84

A putative relay circuit providing low-threshold mechanoreceptive input to lamina I projection neurons via vertical cells in lamina II of the rat dorsal horn  

PubMed Central

Background Lamina I projection neurons respond to painful stimuli, and some are also activated by touch or hair movement. Neuropathic pain resulting from peripheral nerve damage is often associated with tactile allodynia (touch-evoked pain), and this may result from increased responsiveness of lamina I projection neurons to non-noxious mechanical stimuli. It is thought that polysynaptic pathways involving excitatory interneurons can transmit tactile inputs to lamina I projection neurons, but that these are normally suppressed by inhibitory interneurons. Vertical cells in lamina II provide a potential route through which tactile stimuli can activate lamina I projection neurons, since their dendrites extend into the region where tactile afferents terminate, while their axons can innervate the projection cells. The aim of this study was to determine whether vertical cell dendrites were contacted by the central terminals of low-threshold mechanoreceptive primary afferents. Results We initially demonstrated contacts between dendritic spines of vertical cells that had been recorded in spinal cord slices and axonal boutons containing the vesicular glutamate transporter 1 (VGLUT1), which is expressed by myelinated low-threshold mechanoreceptive afferents. To confirm that the VGLUT1 boutons included primary afferents, we then examined vertical cells recorded in rats that had received injections of cholera toxin B subunit (CTb) into the sciatic nerve. We found that over half of the VGLUT1 boutons contacting the vertical cells were CTb-immunoreactive, indicating that they were of primary afferent origin. Conclusions These results show that vertical cell dendritic spines are frequently contacted by the central terminals of myelinated low-threshold mechanoreceptive afferents. Since dendritic spines are associated with excitatory synapses, it is likely that most of these contacts were synaptic. Vertical cells in lamina II are therefore a potential route through which tactile afferents can activate lamina I projection neurons, and this pathway could play a role in tactile allodynia.

2014-01-01

85

Dynamics of Lamin-A Processing Following Precursor Accumulation  

PubMed Central

Lamin A (LaA) is a component of the nuclear lamina, an intermediate filament meshwork that underlies the inner nuclear membrane (INM) of the nuclear envelope (NE). Newly synthesized prelamin A (PreA) undergoes extensive processing involving C-terminal farnesylation followed by proteolysis yielding non-farnesylated mature lamin A. Different inhibitors of these processing events are currently used therapeutically. Hutchinson-Gilford Progeria Syndrome (HGPS) is most commonly caused by mutations leading to an accumulation of a farnesylated LaA isoform, prompting a clinical trial using farnesyltransferase inhibitors (FTI) to reduce this modification. At therapeutic levels, HIV protease inhibitors (PI) can unexpectedly inhibit the final processing step in PreA maturation. We have examined the dynamics of LaA processing and associated cellular effects during PI or FTI treatment and following inhibitor washout. While PI reversibility was rapid, with respect to both LaA maturation and associated cellular phenotype, recovery from FTI treatment was more gradual. FTI reversibility is influenced by both cell type and rate of proliferation. These results suggest a less static lamin network than has previously been observed.

Liu, Qian; Kim, Dae In; Syme, Janet; LuValle, Phyllis; Burke, Brian; Roux, Kyle J.

2010-01-01

86

Globular and asymmetric acetylcholinesterase in frog muscle basal lamina sheaths  

PubMed Central

After denervation in vivo, the frog cutaneus pectoris muscle can be led to degenerate by sectioning the muscle fibers on both sides of the region rich in motor endplate, leaving, 2 wk later, a muscle bridge containing the basal lamina (BL) sheaths of the muscle fibers (28). This preparation still contains various tissue remnants and some acetylcholine receptor-containing membranes. A further mild extraction by Triton X-100, a nonionic detergent, gives a pure BL sheath preparation, devoid of acetylcholine receptors. At the electron microscope level, this latter preparation is essentially composed of the muscle BL with no attached plasmic membrane and cellular component originating from Schwann cells or macrophages. Acetylcholinesterase is still present in high amounts in this BL sheath preparation. In both preparations, five major molecular forms (18, 14, 11, 6, and 3.5 S) can be identified that have either an asymmetric or a globular character. Their relative amount is found to be very similar in the BL and in the motor endplate-rich region of control muscle. Thus, observations show that all acetylcholinesterase forms can be accumulated in frog muscle BL.

1986-01-01

87

Recent advances in OCT imaging of the lamina cribrosa.  

PubMed

The lamina cribrosa (LC) is believed to be the site of injury to retinal ganglion cell axons in glaucoma. The ability to visualise this structure has the potential to help increase our understanding of the disease and be useful in the early detection of glaucoma. While for many years the research on the LC was essentially dependent on histology and modelling, a number of recent advances in optical coherence tomography (OCT) have dramatically improved the ability to visualise the LC, such that it is now possible to image the LC in vivo in humans and animals. In this review, we highlight recent advances in OCT imaging of the LC, in the technology, processing and analysis, and discuss the impact that these will have on the ability to diagnose and monitor glaucoma, as well as to expand our understanding of its pathophysiology. With this manuscript, we aspire to share our excitement on the achievements and potential of recent developments as well as advise caution regarding the challenges that remain before imaging of the LC and optic nerve can be used routinely in clinical practice. PMID:24934221

Sigal, Ian A; Wang, Bo; Strouthidis, Nicholas G; Akagi, Tadamichi; Girard, Michael J A

2014-07-01

88

Axon Diversity of Lamina I Local-Circuit Neurons in the Lumbar Spinal Cord  

PubMed Central

Spinal lamina I is a key area for relaying and integrating information from nociceptive primary afferents with various other sources of inputs. Although lamina I projection neurons have been intensively studied, much less attention has been given to local-circuit neurons (LCNs), which form the majority of the lamina I neuronal population. In this work the infrared light-emitting diode oblique illumination technique was used to visualize and label LCNs, allowing reconstruction and analysis of their dendritic and extensive axonal trees. We show that the majority of lamina I neurons with locally branching axons fall into the multipolar (with ventrally protruding dendrites) and flattened (dendrites limited to lamina I) somatodendritic categories. Analysis of their axons revealed that the initial myelinated part gives rise to several unmyelinated small-diameter branches that have a high number of densely packed, large varicosities and an extensive rostrocaudal (two or three segments), mediolateral, and dorsoventral (reaching laminae III–IV) distribution. The extent of the axon and the occasional presence of long, solitary branches suggest that LCNs may also form short and long propriospinal connections. We also found that the distribution of axon varicosities and terminal field locations show substantial heterogeneity and that a substantial portion of LCNs is inhibitory. Our observations indicate that LCNs of lamina I form intersegmental as well as interlaminar connections and may govern large numbers of neurons, providing anatomical substrate for rostrocaudal “processing units” in the dorsal horn. J. Comp. Neurol. 521:2719–2741, 2013.

Szucs, Peter; Luz, Liliana L; Pinho, Raquel; Aguiar, Paulo; Antal, Zsofia; Tiong, Sheena YX; Todd, Andrew J; Safronov, Boris V

2013-01-01

89

High resolution in vivo imaging of the lamina cribrosa  

PubMed Central

The lamina cribrosa (LC) is considered to be the principal site of retinal ganglion cell axon injury in glaucoma. Imaging technology has steadily improved in recent years, allowing greater resolution of fine details of laminar structure. Histological studies have elucidated the details of LC structure, both in normal and glaucomatous eyes, but such studies are limited by smaller sample size, greater difficulty of conducting prospective studies, and possibility of altered tissue architecture during histologic processing. We reviewed the literature describing the LC in primate and human eyes using in vivo imaging devices and provided a brief explanation of the imaging technology and main results of the articles. We also discuss the advantages and limitations of each imaging modality described, including optic disk photography, confocal scanning laser ophthalmoscopy (CSLO) and optical coherence tomography (OCT). These modalities provide en face and/or cross-sectional images of the LC in vivo. Enhanced depth imaging OCT has recently led to important advances in imaging deeper structures of the posterior segment, including the LC. Adaptive optics has been adopted in CSLO and OCT imaging to correct for ocular aberration and has improved resolution and contrast of the LC images. Post-image processing techniques to compensate for light attenuation and enhance contrast in OCT images enabled better visualization of the LC beneath the neuroretinal rim, vascular structures, and scleral rim. Long-wavelength probe OCT has shown good visualization of the LC with improved penetration when combined with swept-source OCT. Contrast agents for enhanced visualization of selective target structures in OCT have been developed. All these technologies hold great promise for improved in vivo imaging of the LC and require further investigation.

Park, Sung C.; Ritch, Robert

2011-01-01

90

Robust Internal Elastic Lamina Fenestration in Skeletal Muscle Arteries  

PubMed Central

Holes within the internal elastic lamina (IEL) of blood vessels are sites of fenestration allowing for passage of diffusible vasoactive substances and interface of endothelial cell membrane projections with underlying vascular smooth muscle. Endothelial projections are sites of dynamic Ca2+ events leading to endothelium dependent hyperpolarization (EDH)-mediated relaxations and the activity of these events increase as vessel diameter decreases. We tested the hypothesis that IEL fenestration is greater in distal vs. proximal arteries in skeletal muscle, and is unlike other vascular beds (mesentery). We also determined ion channel protein composition within the endothelium of intramuscular and non-intramuscular skeletal muscle arteries. Popliteal arteries, subsequent gastrocnemius feed arteries, and first and second order intramuscular arterioles from rat hindlimb were isolated, cut longitudinally, fixed, and imaged using confocal microscopy. Quantitative analysis revealed a significantly larger total fenestration area in second and first order arterioles vs. feed and popliteal arteries (58% and 16% vs. 5% and 3%; N?=?10 images/artery), due to a noticeably greater average size of holes (9.5 and 3.9 µm2 vs 1.5 and 1.9 µm2). Next, we investigated via immunolabeling procedures whether proteins involved in EDH often embedded in endothelial cell projections were disparate between arterial segments. Specific proteins involved in EDH, such as inositol trisphosphate receptors, small and intermediate conductance Ca2+-activated K+ channels, and the canonical (C) transient receptor potential (TRP) channel TRPC3 were present in both popliteal and first order intramuscular arterioles. However due to larger IEL fenestration in first order arterioles, a larger spanning area of EDH proteins is observed proximal to the smooth muscle cell plasma membrane. These observations highlight the robust area of fenestration within intramuscular arterioles and indicate that the anatomical architecture and endothelial cell hyperpolarizing apparatus for distinct vasodilatory signaling is potentially present.

Sullivan, Michelle N.; Francis, Michael; Dinenno, Frank A.; Earley, Scott

2013-01-01

91

Investigating Invasives  

NSDL National Science Digital Library

Invasive species, commonly known as "invasives," are nonnative plants, animals, and microbes that completely take over and change an established ecosystem. The consequences of invasives' spread are significant. In fact, many of the species that appear on the Endangered Species list are threatened by invasives. Therefore, the topic of invasive nonnative species can provide the focus for projects that engage students in authentic science investigations. Here the author describes how she launched her students into a study of invasives while supporting their local environment using the 5E Learning Cycle (engage, explore, explain, extend, evaluate).

Lightbody, Mary

2008-11-01

92

Isothermal life prediction of composite lamina using a damage mechanics approach  

NASA Technical Reports Server (NTRS)

A method for predicting isothermal plastic fatigue life of a composite lamina is presented in which both fibers and matrix are isotropic materials. In general, the fatigue resistances of the matrix, fibers, and interfacial material must be known in order to predict composite fatigue life. Composite fatigue life is predicted using only the matrix fatigue resistance due to inelasticity micromechanisms. The effect of the fiber orientation on loading direction is accounted for while predicting composite life. The application is currently limited to isothermal cases where the internal thermal stresses that might arise from thermal strain mismatch between fibers and matrix are negligible. The theory is formulated to predict the fatigue life of a composite lamina under either load or strain control. It is applied currently to predict the life of tungsten-copper composite lamina at 260 C under tension-tension load control. The calculated life of the lamina is in good agreement with available composite low cycle fatigue data.

Abuelfoutouh, Nader M.; Verrilli, Michael J.; Halford, Gary R.

1989-01-01

93

Synaptic input of rat spinal lamina I projection and unidentified neurones in vitro  

PubMed Central

Spinal lamina I projection neurones that transmit nociceptive information to the brain play a pivotal role in hyperalgesia in various animal models of inflammatory and neuropathic pain. Consistently, activity-dependent long-term potentiation can be induced at synapses between primary afferent C-fibres and lamina I projection neurones but not unidentified neurones in lamina I. The specific properties that enable projection neurones to undergo long-term potentiation and mediate hyperalgesia are not fully understood. Here, we have tested whether lamina I projection neurones differ from unidentified neurones in types or strength of primary afferent input and/or action potential-independent excitatory and inhibitory input. We used the whole-cell patch-clamp technique to record synaptic currents in projection and unidentified lamina I neurones in a transverse lumbar spinal cord slice preparation from rats between postnatal day 18 and 37. Lamina I neurones with a projection to the parabrachial area or the periaqueductal grey were identified by retrograde labelling with a fluorescent tracer. The relative contribution of NMDA receptors versus AMPA/kainate receptors to C-fibre-evoked excitatory postsynaptic currents of lamina I neurones significantly decreased with age between postnatal day 18 and 27, but was independent of the supraspinal projection of the neurones. We did not find a significant contribution of kainate receptors to C-fibre-evoked excitatory postsynaptic currents. Lamina I projection and unidentified neurones possessed functional GABAA and glycine receptors but received scarce action potential-independent spontaneous GABAergic and glycinergic inhibitory input as measured by miniature inhibitory postsynaptic currents. The miniature excitatory postsynaptic current frequencies were five times higher in projection than in unidentified neurones. The predominance of excitatory synaptic input to projection neurones, taken together with the previous finding that their membranes are more easily excitable than those of unidentified neurones, may facilitate the induction of synaptic long-term potentiation.

Dahlhaus, Anne; Ruscheweyh, Ruth; Sandkuhler, Jurgen

2005-01-01

94

Basal lamina directs acetylcholinesterase accumulation at synaptic sites in regenerating muscle  

PubMed Central

In skeletal muscles that have been damaged in ways which spare the basal lamina sheaths of the muscle fibers, new myofibers develop within the sheaths and neuromuscular junctions form at the original synaptic sites on them. At the regenerated neuromuscular junctions, as at the original ones, the muscle fibers are characterized by junctional folds and accumulations of acetylcholine receptors and acetylcholinesterase (AChE). The formation of junctional folds and the accumulation of acetylcholine receptors is known to be directed by components of the synaptic portion of the myofiber basal lamina. The aim of this study was to determine whether or not the synaptic basal lamina contains molecules that direct the accumulation of AChE. We crushed frog muscles in a way that caused disintegration and phagocytosis of all cells at the neuromuscular junction, and at the same time, we irreversibly blocked AChE activity. New muscle fibers were allowed to regenerate within the basal lamina sheaths of the original muscle fibers but reinnervation of the muscles was deliberately prevented. We then stained for AChE activity and searched the surface of the new muscle fibers for deposits of enzyme they had produced. Despite the absence of innervation, AChE preferentially accumulated at points where the plasma membrane of the new muscle fibers was apposed to the regions of the basal lamina that had occupied the synaptic cleft at the neuromuscular junctions. We therefore conclude that molecules stably attached to the synaptic portion of myofiber basal lamina direct the accumulation of AChE at the original synaptic sites in regenerating muscle. Additional studies revealed that the AChE was solubilized by collagenase and that it remained adherent to basal lamina sheaths after degeneration of the new myofibers, indicating that it had become incorporated into the basal lamina, as at normal neuromuscular junctions.

1985-01-01

95

The hydraulic conductance of the angiosperm leaf lamina: a comparison of three measurement methods.  

PubMed

A comparison was made of three methods for measuring the leaf lamina hydraulic conductance (K(lamina)) for detached mature leaves of six woody temperate angiosperm species. The high-pressure method, the evaporative flux method and the vacuum pump method involve, respectively, pushing, evaporating and pulling water out of the lamina while determining the flow rate into the petiole and the water potential drop across the leaf. Tests were made of whether the high-pressure method and vacuum pump method measurements of K(lamina) on single leaves were affected by irradiance. In Quercus rubra, the high pressure method was sensitive to irradiance; K(lamina) measured under high irradiance (>1200 micro mol m(-2) s(-1 )photosynthetically active radiation) was 4.6-8.8 times larger than under ambient laboratory lighting (approximately 6 micro mol m(-2) s(-1 )photosynthetically active radiation). By constrast, the vacuum pump method was theoretically expected to be insensitive to irradiance, and this expectation was confirmed in experiments on Hedera helix. When used in the ways recommended here, the three methods produced measurements that agreed typically within 10%. There were significant differences in species' K(lamina); values ranged from 1.24x10(-4) kg s(-1) m(-2) MPa(-1) for Acer saccharum to 2.89x10(-4) kg s(-1) m(-2) MPa(-1) for Vitis labrusca. Accurate, rapid determination of K(lamina) will allow testing of the links between K(lamina), water-use, drought tolerance, and the enormous diversity of leaf form, structure and composition. PMID:12379784

Sack, Lawren; Melcher, Peter J; Zwieniecki, Maciej A; Holbrook, N Michele

2002-11-01

96

Formation of an ozone lamina due to differential advection revealed by intensive observations  

Microsoft Academic Search

An intensive observation with ozonesondes, radiosondes, and the Middle and Upper atmosphere (MU) radar was conducted at Shigaraki (34.9°N, 136.1°E), Japan, from 16 through 24 April 1998 to investigate the formation mechanism of ozone laminae in the midlatitude lower stratosphere. In these observations the temporal variation of an ozone lamina at Shigaraki was continuously observed through a short time interval

Yoshihiro Tomikawa; Kaoru Sato; Kazuyuki Kita; Masatomo Fujiwara; Miho Yamamori; Takuki Sano

2002-01-01

97

The meiotic nuclear lamina regulates chromosome dynamics and promotes efficient homologous recombination in the mouse.  

PubMed

The nuclear lamina is the structural scaffold of the nuclear envelope and is well known for its central role in nuclear organization and maintaining nuclear stability and shape. In the past, a number of severe human disorders have been identified to be associated with mutations in lamins. Extensive research on this topic has provided novel important clues about nuclear lamina function. These studies have contributed to the knowledge that the lamina constitutes a complex multifunctional platform combining both structural and regulatory functions. Here, we report that, in addition to the previously demonstrated significance for somatic cell differentiation and maintenance, the nuclear lamina is also an essential determinant for germ cell development. Both male and female mice lacking the short meiosis-specific A-type lamin C2 have a severely defective meiosis, which at least in the male results in infertility. Detailed analysis revealed that lamin C2 is required for telomere-driven dynamic repositioning of meiotic chromosomes. Loss of lamin C2 affects precise synapsis of the homologs and interferes with meiotic double-strand break repair. Taken together, our data explain how the nuclear lamina contributes to meiotic chromosome behaviour and accurate genome haploidization on a mechanistic level. PMID:23382700

Link, Jana; Jahn, Daniel; Schmitt, Johannes; Göb, Eva; Baar, Johannes; Ortega, Sagrario; Benavente, Ricardo; Alsheimer, Manfred

2013-01-01

98

Identity of Myelinated Cutaneous Sensory Neurons Projecting to Nocireceptive Laminae Following Nerve Injury in Adult Mice  

PubMed Central

It is widely thought that, after peripheral injury, some low-threshold mechanoreceptive (LTMR) afferents “sprout” into pain-specific laminae (I–II) of the dorsal horn and are responsible for chronic pain states such as mechanical allodynia. Although recent studies have questioned this hypothesis, they fail to account for a series of compelling results from single-fiber analyses showing extensive projections from large-diameter myelinated afferents into nocireceptive layers after nerve injury. Here we show that, in the thoracic spinal cord of naïve adult mouse, all myelinated nociceptors gave rise to terminal projections throughout the superficial dorsal horn laminae (I–II). Most (70%) of these fibers had large-diameter axons with recurving flame-shaped central arbors that projected throughout the dorsal horn laminae I–V. This morphology was reminiscent of that attributed to sprouted LTMRs described in previous studies. After peripheral nerve axotomy, we found that LTMR afferents with narrow, uninflected somal action potentials did not sprout into superficial laminae of the dorsal horn. Only myelinated noiceptive afferents with broad, inflected somal action potentials were found to give rise to recurving collaterals and project into superficial “pain-specific” laminae after axotomy. We conclude that the previously undocumented central morphology of large, myelinated cutaneous nociceptors may very well account for the morphological findings previously thought to require sprouting of LTMRs.

WOODBURY, C. JEFFERY; KULLMANN, FLORENTA A.; McILWRATH, SABRINA L.; KOERBER, H. RICHARD

2009-01-01

99

Application of lamina replantation with ARCH plate fixation in thoracic and lumbar intraspinal tumors  

PubMed Central

The aim of the present study was to investigate the clinical effects of lamina replantation with ARCH plate fixation on patients with thoracic and lumbar intraspinal tumors, following laminectomy. Thirteen patients with thoracic and lumbar intraspinal tumors underwent total lamina replantation with ARCH plate fixation and repair of the supraspinous ligaments, following laminectomy and tumor enucleation. To investigate the clinical effect of lamina replantation with ARCH plate fixation, pre- and postoperative visual analog scale (VAS), and Oswestry Disability Index (ODI) scores were determined, and pre- and postoperative X-ray and magnetic resonance imaging (MRI) examinations were conducted. Computed tomography (CT) examinations were also included in the follow-up. No complications were observed pre- or postoperatively. The VAS and ODI results 2 weeks following surgery and at the final follow-up examination demonstrated a significant improvement compared with the corresponding preoperative results. The X-ray examination results indicated a satisfactory internal fixation location, without any characteristics of a fracture, lumbar scoliosis, kyphosis or instability. Following the surgery, the CT and MRI examination results demonstrated that healing of the lamina bone and repair of the supraspinous ligament had occurred without tumor recurrence or spinal epidural scar recompression. Two of the 13 cases were lost to follow-up. The results indicated that in patients with thoracic and lumbar intraspinal tumors, lamina replantation with ARCH plate fixation following total laminectomy is effective and provides thoracolumbar stability. Furthermore, this has been identified to be an effective technique for preventing intraspinal scar proliferation.

ZHOU, DONG; NONG, LU-MING; GAO, GONG-MIN; JIANG, YU-QIN; XU, NAN-WEI

2013-01-01

100

The Meiotic Nuclear Lamina Regulates Chromosome Dynamics and Promotes Efficient Homologous Recombination in the Mouse  

PubMed Central

The nuclear lamina is the structural scaffold of the nuclear envelope and is well known for its central role in nuclear organization and maintaining nuclear stability and shape. In the past, a number of severe human disorders have been identified to be associated with mutations in lamins. Extensive research on this topic has provided novel important clues about nuclear lamina function. These studies have contributed to the knowledge that the lamina constitutes a complex multifunctional platform combining both structural and regulatory functions. Here, we report that, in addition to the previously demonstrated significance for somatic cell differentiation and maintenance, the nuclear lamina is also an essential determinant for germ cell development. Both male and female mice lacking the short meiosis-specific A-type lamin C2 have a severely defective meiosis, which at least in the male results in infertility. Detailed analysis revealed that lamin C2 is required for telomere-driven dynamic repositioning of meiotic chromosomes. Loss of lamin C2 affects precise synapsis of the homologs and interferes with meiotic double-strand break repair. Taken together, our data explain how the nuclear lamina contributes to meiotic chromosome behaviour and accurate genome haploidization on a mechanistic level.

Schmitt, Johannes; Gob, Eva; Baar, Johannes; Ortega, Sagrario; Benavente, Ricardo; Alsheimer, Manfred

2013-01-01

101

Nuclear envelope lamin-a couples actin dynamics with immunological synapse architecture and T cell activation.  

PubMed

In many cell types, nuclear A-type lamins regulate multiple cellular functions, including higher-order genome organization, DNA replication and repair, gene transcription, and signal transduction; however, their role in specialized immune cells remains largely unexplored. We showed that the abundance of A-type lamins was almost negligible in resting naïve T lymphocytes, but was increased upon activation of the T cell receptor (TCR). The increase in lamin-A was an early event that accelerated formation of the immunological synapse between T cells and antigen-presenting cells. Polymerization of F-actin in T cells is a critical step for immunological synapse formation, and lamin-A interacted with the linker of nucleoskeleton and cytoskeleton (LINC) complex to promote F-actin polymerization. We also showed that lamin-A expression accelerated TCR clustering and led to enhanced downstream signaling, including extracellular signal-regulated kinase 1/2 (ERK1/2) signaling, as well as increased target gene expression. Pharmacological inhibition of the ERK pathway reduced lamin-A-dependent T cell activation. Moreover, mice lacking lamin-A in immune cells exhibited impaired T cell responses in vivo. These findings underscore the importance of A-type lamins for TCR activation and identify lamin-A as a previously unappreciated regulator of the immune response. PMID:24757177

González-Granado, José M; Silvestre-Roig, Carlos; Rocha-Perugini, Vera; Trigueros-Motos, Laia; Cibrián, Danay; Morlino, Giulia; Blanco-Berrocal, Marta; Osorio, Fernando G; Freije, José M P; López-Otín, Carlos; Sánchez-Madrid, Francisco; Andrés, Vicente

2014-01-01

102

Seasonal Evolution of Rossby and Gravity Wave Induced Laminae in Ozonesonde Data Obtained from Wallops Island, Virginia  

NASA Technical Reports Server (NTRS)

A method for evaluating the seasonal evolution of ozone laminae using ozonesonde data is discussed. The method uses the correlation between small-scale ozone and potential temperature variations to distinguish between laminae generated by quasi-isentropic filamentation by Rossby waves and by vertical displacements of material surfaces by gravity waves. Data from Wallops Island, Virginia show that Rossby wave induced ozone laminae are most frequently encountered at Wallops during the winter months near 15 km while statistically significant gravity wave induced laminae occur above 15 km during the early winter and at the tropopause from late winter through early spring.

Pierce, R. Bradley; Grant, William B.

1998-01-01

103

Acetylcholinesterase from the motor nerve terminal accumulates on the synaptic basal lamina of the myofiber  

PubMed Central

Acetylcholinesterase (AChE) in skeletal muscle is concentrated at neuromuscular junctions, where it is found in the synaptic cleft between muscle and nerve, associated with the synaptic portion of the myofiber basal lamina. This raises the question of whether the synaptic enzyme is produced by muscle, nerve, or both. Studies on denervated and regenerating muscles have shown that myofibers can produce synaptic AChE, and that the motor nerve may play an indirect role, inducing myofibers to produce synaptic AChE. The aim of this study was to determine whether some of the AChE which is known to be made and transported by the motor nerve contributes directly to AChE in the synaptic cleft. Frog muscles were surgically damaged in a way that caused degeneration and permanent removal of all myofibers from their basal lamina sheaths. Concomitantly, AChE activity was irreversibly blocked. Motor axons remained intact, and their terminals persisted at almost all the synaptic sites on the basal lamina in the absence of myofibers. 1 mo after the operation, the innervated sheaths were stained for AChE activity. Despite the absence of myofibers, new AChE appeared in an arborized pattern, characteristic of neuromuscular junctions, and its reaction product was concentrated adjacent to the nerve terminals, obscuring synaptic basal lamina. AChE activity did not appear in the absence of nerve terminals. We concluded therefore, that the newly formed AChE at the synaptic sites had been produced by the persisting axon terminals, indicating that the motor nerve is capable of producing some of the synaptic AChE at neuromuscular junctions. The newly formed AChE remained adherent to basal lamina sheaths after degeneration of the terminals, and was solubilized by collagenase, indicating that the AChE provided by nerve had become incorporated into the basal lamina as at normal neuromuscular junctions.

1991-01-01

104

Glutamate, GABA and Acetylcholine Signaling Components in the Lamina of the Drosophila Visual System  

PubMed Central

Synaptic connections of neurons in the Drosophila lamina, the most peripheral synaptic region of the visual system, have been comprehensively described. Although the lamina has been used extensively as a model for the development and plasticity of synaptic connections, the neurotransmitters in these circuits are still poorly known. Thus, to unravel possible neurotransmitter circuits in the lamina of Drosophila we combined Gal4 driven green fluorescent protein in specific lamina neurons with antisera to ?-aminobutyric acid (GABA), glutamic acid decarboxylase, a GABAB type of receptor, L-glutamate, a vesicular glutamate transporter (vGluT), ionotropic and metabotropic glutamate receptors, choline acetyltransferase and a vesicular acetylcholine transporter. We suggest that acetylcholine may be used as a neurotransmitter in both L4 monopolar neurons and a previously unreported type of wide-field tangential neuron (Cha-Tan). GABA is the likely transmitter of centrifugal neurons C2 and C3 and GABAB receptor immunoreactivity is seen on these neurons as well as the Cha-Tan neurons. Based on an rdl-Gal4 line, the ionotropic GABAA receptor subunit RDL may be expressed by L4 neurons and a type of tangential neuron (rdl-Tan). Strong vGluT immunoreactivity was detected in ?-processes of amacrine neurons and possibly in the large monopolar neurons L1 and L2. These neurons also express glutamate-like immunoreactivity. However, antisera to ionotropic and metabotropic glutamate receptors did not produce distinct immunosignals in the lamina. In summary, this paper describes novel features of two distinct types of tangential neurons in the Drosophila lamina and assigns putative neurotransmitters and some receptors to a few identified neuron types.

Kolodziejczyk, Agata; Sun, Xuejun; Meinertzhagen, Ian A.; Nassel, Dick R.

2008-01-01

105

Genome regulation at the peripheral zone: lamina associated domains in development and disease.  

PubMed

The nuclear periphery has been implicated in gene regulation and it has been proposed that proximity to the nuclear lamina and inner nuclear membrane (INM) leads to gene repression. More recently, it appears that there is a correlation and interdependence between lamina associated domains (LADs), the epigenome and overall three-dimensional architecture of the genome. However, the mechanisms of such organization at the 'peripheral zone' and the functional significance of these associations are poorly understood. The role these domains play in development and disease is an active and exciting area of research, expanding our knowledge of how the three-dimensional (3D) genome is regulated. PMID:24556270

Luperchio, Teresa R; Wong, Xianrong; Reddy, Karen L

2014-04-01

106

Patterns of Internal Elastic Lamina Morphology in the Canine Common Carotid Artery  

Microsoft Academic Search

The internal elastic lamina (IEL) of normal canine carotid arteries was examined by scanning electron microscopy in pressure-fixed specimens with intact endothelium. IEL appearance showed a marked variation between animals and was classified into fenestrated sheet, fibrous, and mixed varieties. This interpretation of the apparent morphology was confirmed with transmission electron microscopy. It was clear that IEL fenestrae were associated

K. J. Hutchison; E. J. Sanders

1990-01-01

107

Inelastic deformation mechanisms in SCS-6/Ti 15-3 MMC lamina under compression  

NASA Technical Reports Server (NTRS)

An investigation was undertaken to study the inelastic deformation mechanisms in (0)(sub 8) and (90)(sub 8) Ti 15-3/SCS-6 lamina subjected to pure compression. Monotonic tests were conducted at room temperature (RT), 538 C and 650 C. Results indicate that mechanical response and deformation characteristics were different in monotonic tension and compression loading whereas some of those differences could be attributed to residual stress effects. There were other differences because of changes in damage and failure modes. The inelastic deformation in the (0)(sub 8) lamina under compression was controlled primarily by matrix plasticity, although some evidence of fiber-matrix debonding was observed. Failure of the specimen in compression was due to fiber buckling in a macroscopic shear zone (the failure plane). The inelastic deformation mechanisms under compression in (90)(sub 8) lamina were controlled by radial fiber fracture, matrix plasticity, and fiber-matrix debonding. The radial fiber fracture was a new damage mode observed for MMC's. Constitutive response was predicted for both the (0)(sub 8) and (90)(sub 8) laminae, using AGLPLY, METCAN, and Battelle's Unit Cell FEA model. Results from the analyses were encouraging.

Newaz, Golam M.; Majumdar, Bhaskar S.

1993-01-01

108

Quantitative basis for neuroimaging of cortical laminae with calibrated functional MRI  

PubMed Central

Layer-specific neurophysiologic, hemodynamic, and metabolic measurements are needed to interpret high-resolution functional magnetic resonance imaging (fMRI) data in the cerebral cortex. We examined how neurovascular and neurometabolic couplings vary vertically in the rat’s somatosensory cortex. During sensory stimulation we measured dynamic layer-specific responses of local field potential (LFP) and multiunit activity (MUA) as well as blood oxygenation level-dependent (BOLD) signal and cerebral blood volume (CBV) and blood flow (CBF), which in turn were used to calculate changes in oxidative metabolism (CMRO2) with calibrated fMRI. Both BOLD signal and CBV decreased from superficial to deep laminae, but these responses were not well correlated with either layer-specific LFP or MUA. However, CBF changes were quite stable across laminae, similar to LFP. However, changes in CMRO2 and MUA varied across cortex in a correlated manner and both were reduced in superficial lamina. These results lay the framework for quantitative neuroimaging across cortical laminae with calibrated fMRI methods.

Herman, Peter; Sanganahalli, Basavaraju G.; Blumenfeld, Hal; Rothman, Douglas L.; Hyder, Fahmeed

2013-01-01

109

Changes in the collagenous matrix of the aging human lamina cribrosa.  

PubMed Central

AIMS--The age-related changes in the biochemical composition of the collagenous matrix of the human lamina cribrosa were investigated. METHODS--An age range (3 weeks to 92 years old) of human laminae cribrosae, dissected free of any surrounding structures which contained collagen, were analysed for collagen solubility (n = 58) total collagen content (n = 46), proportion of collagen types (n = 38), and collagen cross linking (n = 30), using hydroxyproline analysis, scanning densitometry of peptides after cyanogen bromide digestion, and high performance liquid chromatography, respectively. RESULTS--Age-related changes included an increase in total collagen and a decrease in the proportion of type III collagen within the lamina cribrosa. The collagen cross link pyridinoline was present at low levels, but demonstrated no trend with age. An age-related increase was found in pentosidine, an advanced glycation product. CONCLUSION--These changes in collagen composition imply that the mechanical properties of the lamina cribrosa are altered, resulting in a stiffer, less resilient structure with age. Such alterations in structure may contribute to the increased susceptibility of the elderly to axonal damage in chronic open angle glaucoma. Images

Albon, J; Karwatowski, W S; Avery, N; Easty, D L; Duance, V C

1995-01-01

110

Agrin Binds to the Nerve-Muscle Basal Lamina via Laminin  

Microsoft Academic Search

Abstract Agrin is a heparan sulfate proteoglycan that is required for the formation and maintenance,of neuromuscular junctions. During development, agrin is secreted from motor neurons to trigger the local aggregation of acetylcholinereceptors (AChRs) and other proteins in the muscle fiber, which together compose the postsynaptic apparatus. After release from the motor neuron, agrin binds to the developing muscle basal lamina

A. J. Denzer

1997-01-01

111

Patterns of projection in the visual system of the fly. I. Retina-lamina projections  

Microsoft Academic Search

Summary  In each compound eye of the fly about 3200 ommatidia are arranged in a peculiarly distorted hexagonal array. Each ommatidium contains 7+1 rhabdomeres arranged in the asymmetrical pattern of the retinula. 7 fibers leaving each ommatidium are distributed onto 7 synaptic sites in the first optic ganglion (lamina ganglionaris), again arranged asymmetrically around the axis of the ommatidium. Taking into

V. Braitenberg

1967-01-01

112

Analysis of reinforced concrete columns retrofitted with fiber reinforced polymer lamina  

Microsoft Academic Search

Fiber reinforced polymer (FRP) lamina have been used widely in the last decade to enhance strength and deformation capacity of deficient reinforced concrete (RC) columns. Seismic assessment and retrofit of existing columns in buildings and bridge piers necessitate accurate prediction of the available deformation capacity. In this study, a new analytical model is proposed to represent potential plastic hinge regions

Baris Binici; Khalid M. Mosalam

2007-01-01

113

[Treatment of frontal interhemispheric arachnoid cysts by fenestration of the lamina terminalis].  

PubMed

Two cases of frontal interhemispheric cysts have been treated by fenestration of the Lamina Terminalis. Clinical and radiological results were good with a CT follow-up 6 and 7 years after surgery. This procedure avoids the interposition of prosthesis. Actually it could be simplified by the use of endoscopic technics. PMID:8065489

Riviérez, M

1993-01-01

114

Differentiation of Axon-Related Schwann Cells in V&O: II. Control of Myelin Formation by Basal Lamina  

Microsoft Academic Search

Several recent observations suggest that Schwann cell (SC) differentiation, including myelin formation, is dependent upon the development of basal lamina which characteristically surrounds each axon-SC unit in peripheral nerve. This de- pendence can be tested in a neuron-SC culture system de- veloped in our laboratory in which SC differentiation, includ- ing basal lamina formation and myelination, is faithfully reproduced. The

Charles F. Eldridge; Mary Bartlett Bungs; Richard P. Bunge

115

The nuclear lamina and its proposed roles in tumorigenesis: Projection on the hematologic malignancies and future targeted therapy  

Microsoft Academic Search

The nuclear lamina, a network of lamin filaments and lamin-associated proteins, is located between the inner nuclear membrane and the peripheral chromatin. The nuclear lamina is involved in numerous nuclear functions including maintaining nuclear shape, determining nuclear positioning, organizing chromatin and regulating the cell cycle, DNA replication, transcription, cell differentiation, apoptosis, and aging. Alterations in the composition of nuclear lamins

Miron Prokocimer; Ayelet Margalit; Yosef Gruenbaum

2006-01-01

116

Differentiation of axon-related Schwann cells in vitro. I. Ascorbic acid regulates basal lamina assembly and myelin formation  

Microsoft Academic Search

Rat Schwann cells cultured with dorsal root ganglion neurons in a serum-free defined medium fail to ensheathe or myelinate axons or assemble basal laminae. Replacement of defined medium with medium that contains human placental serum (HPS) and chick embryo extract (EE) results in both basal lamina and myelin formation. In the present study, the individual effects of HPS and EE

Charles E Eldridge; Mary Bartlett Bunge; Richard P. Bunge; Patrick M. Wood

1987-01-01

117

Immunocytochemical localization of the major polypeptides of the nuclear pore complex-lamina fraction. Interphase and mitotic distribution  

PubMed Central

This laboratory has previously isolated a fraction from rat liver nuclei consisting of nuclear pore complexes associated with the proteinaceous lamina which underlies the inner nuclear membrane. Using protein eluted from sodium dodecyl sulfate (SDS) gels, we have prepared antibodies in chickens to each of the three predominant pore complex- lamina bands. Ouchterlony double diffusion analysis shows that each of these individual bands cross-reacts strongly with all three antisera. In immunofluorescence localization performed on tissue culture cells with these antibodies, we obtain a pattern of intense staining at the periphery of the interphase nucleus, with little or no cytoplasmic reaction. Electron microscope immunoperoxidase staining of rat liver nuclei with these antibodies labels exclusively the nuclear periphery. Furthermore, reaction occurs in areas which contain the lamina, but not at the pore complexes. While our isolation procedure extracts the internal contents of nuclei completely, semiquantitative Ouchterlony analysis shows that it releases negligible amounts of these lamina antigens. Considered together, our results indicate that these three bands represent major components of a peripheral nuclear lamina, and are not structural elements of an internal "nuclear protein matrix." Fluorescence microscopy shows that the perinuclear interphase localization of these lamina proteins undergoes dramatic changes during mitosis. Concomitant with nuclear envelope disassembly in prophase, these antigens assume a diffuse localization throughout the cell. This distribution persists until telophase, when the antigens become progressively and completely localized at the surface of the daughter chromosome masses. We propose that the lamina is a biological polymer which can undergo reversible disassembly during mitosis.

1978-01-01

118

Corelease of GABA/glycine in lamina-X of the spinal cord of neonatal rats.  

PubMed

Spinal-cord slices from neonatal rats were used to record lamina-X neurons using the patch-clamp technique under whole cell recording configuration. Lamina-X surrounds the central canal of the spinal cord and contains sympathetic preganglionic neurons of the central autonomic nucleus. Miniature inhibitory postsynaptic currents were recorded in the presence of tetrodotoxin and kynurenic acid to block action potential-dependent transmitter release and glutamatergic transmissions, respectively. We recorded mixed gamma-amino-n-butyric acid/glycine miniature synaptic currents suggesting that gamma-amino-n-butyric acid and glycine can be coreleased from the same single synaptic vesicles, and that this corelease can be detected by the postsynaptic cell. In addition, acetylcholine can induce the release of gamma-amino-n-butyric acid/glycine by acting presynaptically at nicotinic receptors located on the gamma-amino-n-butyric acid ergic/glycinergic terminals. PMID:17558289

Seddik, Riad; Schlichter, Rémy; Trouslard, Jérôme

2007-07-01

119

Alien Invasion  

NSDL National Science Digital Library

In this activity students will work in teams to investigate the impact of an invasive species on native species, using the six classic steps for solving environmental problems. Teams will research a local invasive species problem, complete an experimental design plan, write clear procedures for experimentation, state expected results and conclusions, and work together to determine the course of action to be taken and future monitoring needs. Teams will present their action plan to a simulated board of review through a formal presentation. While completing this activity students will learn to create a workable experimental design, create clear experimental procedures, and practice peer review.

Maben, Ann

120

Cultured incisors display major modifications in basal lamina deposition without further effect on odontoblast differentiation  

Microsoft Academic Search

Matrix-mediated epithelio-mesenchymal interactions play a crucial role in the control of dental cytodifferentiations. Ultrastructural observation of the epithelio-mesenchymal junction in cultured embryonic mouse molars showed discrete zones with duplicated or multilayered basal laminae. The use of synthetic peptides demonstrated that the process was RGD*-independent, did not involve the YIGSR* sequence present on laminin and could occur spontaneously. Cultured incisors showed

Jean-Marie Meyer; Jean Victor Ruch; Marie Dominique Kubler; Christian Kupferle; Hervé Lesot

1995-01-01

121

?1Class Integrins Regulate the Development of Laminae and Folia in the Cerebral and Cerebellar Cortex  

Microsoft Academic Search

Mice that lack all ?1-class integrins in neurons and glia die prematurely after birth with severe brain malformations. Cortical hemispheres and cerebellar folia fuse, and cortical laminae are perturbed. These defects result from disorganization of the cortical marginal zone, where ?1-class integrins regulate glial endfeet anchorage, meningeal basement membrane remodeling, and formation of the Cajal-Retzius cell layer. Surprisingly, ?1-class integrins

Diana Graus-Porta; Sandra Blaess; Mathias Senften; Amanda Littlewood-Evans; Caroline Damsky; Zhen Huang; Paul Orban; Rüdiger Klein; Johannes C. Schittny; Ulrich Müller

2001-01-01

122

Endoscopic surgery of the third ventricle: the subfrontal trans-lamina terminalis approach.  

PubMed

The authors describe an endoscopic approach to the anterior aspect of the third ventricle and demonstrate its use in the cadaver. This technique consists of a small supraorbital craniotomy and a subfrontal trans-lamina terminalis approach to the third ventricle. It may be helpful in the management of refractory third ventricular lesions that cannot be easily accessed endoscopically through the foramina of Monro. PMID:11270833

Abdou, M S; Cohen, A R

2000-12-01

123

Helminthotoxic responses of intestinal eosinophils to Trichinella spiralis newborn larvae.  

PubMed Central

Because the gastrointestinal lamina propria is the first line of defense against invasion with Trichinella spiralis newborn larvae, we investigated the helminthotoxic characteristics of isolated lamina propria eosinophils. Eosinophils were isolated from the intestinal lamina propria of rats and purified to nearly 90% purity by a combination of velocity sedimentation through Percoll and unit gravity sedimentation through a continuous gradient of bovine serum albumin. Isolated eosinophils were of high viability and responded to surface receptor stimulation. Freshly isolated intestinal eosinophils lacked cytotoxic capacity when incubated with newborn larvae in the presence of specific antiserum. Peritoneal eosinophils from the same rats exhibited 100% helminthotoxicity after 24 h. Cytotoxicity could be stimulated in the intestinal eosinophils by the addition of recombinant murine interleukin-5.

Lee, T D

1991-01-01

124

Morphology of inhibitory and excitatory interneurons in superficial laminae of the rat dorsal horn  

PubMed Central

If we are to stand any chance of understanding the circuitry of the superficial dorsal horn, it is imperative that we can identify which classes of interneuron are excitatory and which are inhibitory. Our aim was to test the hypothesis that there is a correlation between the morphology of an interneuron and its postsynaptic action. We used in vitro slice preparations of the rat spinal cord to characterize and label interneurons in laminae I–III with Neurobiotin. Labelled cells (n= 19) were reconstructed in 3D with Neurolucida and classified according to the scheme proposed by Grudt & Perl (2002). We determined if cells were inhibitory or excitatory by reacting their axon terminals with antibodies to reveal glutamate decrboxylase (for GABAergic cells) or the vesicular glutamate transporter 2 (for glutamatergic cells). All five islet cells retrieved were inhibitory. Of the six vertical (stalked) cells analysed, four were excitatory and, surprisingly, two were inhibitory. It was noted that these inhibitory cells had axonal projections confined to lamina II whereas excitatory vertical cells projected to lamina I and II. Of the remaining neurons, three were radial cells (2 inhibitory, 1 excitatory), two were antennae cells (1 inhibitory, 1 excitatory), one was an inhibitory central cell and the remaining two were unclassifiable excitatory cells. Our hypothesis appears to be correct only for islet cells. Other classes of cells have mixed actions, and in the case of vertical cells, the axonal projection appears to be a more important determinant of postsynaptic action.

Maxwell, David J; Belle, Mino D; Cheunsuang, Ornsiri; Stewart, Anika; Morris, Richard

2007-01-01

125

[Study on the modeling of hyperspectral polarized reflection of clove lamina with chlorophyll content].  

PubMed

In the present study, the authors detected clove laminas in different states with multi-angle hyperspectral polarized reflections and measured their chlorophyll content at the same time. The authors analyzed hyperspectral polarized reflections of clove laminas from various viewing zenith angles, incidence angles, the relative azimuth angles, polarized states and chlorophyll content. The authors calculated quantitatively clove laminas in different states with multi-angle hyperspectral polarized reflection by USB2000, bidirectional polarized reflectance and polarized equipment, and built the regression models of polarized information-chlorophyll content. The result indicated that when the polarized angle was 0 degrees, the model of chlorophyll content with polarization reflectance was built as Y = 4. 506 4e(-0.56 8x) (R2 = 0.895 8); while as the polarized angle was 90 degrees, the model of chlorophyll content with polarization reflectance was built as Y = 145.79X(-1.204 1)(R2 = 0.479 8); when the incidence angle was 50 degrees, the model of chlorophyll content with degree of polarization was built as Y = 7 206.7X(6) -20 160 X(5) + 22 547X(4)-12 788X(5) + 3 822.4X(2) -553.72X + 30.429 (R2 = 0.646 4). The authors found that a significant functional relationship between the polarized information and chlorophyll content exists. The study provides a theoretical base for vegetation remote sensing. PMID:19810539

Han, Yang; Zhao, Yun-Sheng; Zhang, Li-Li; Lü, Yun-Feng

2009-06-01

126

Multi-scale Rule-of-Mixtures Model of Carbon Nanotube/Carbon Fiber/Epoxy Lamina  

NASA Technical Reports Server (NTRS)

A unidirectional carbon fiber/epoxy lamina in which the carbon fibers are coated with single-walled carbon nanotubes is modeled with a multi-scale method, the atomistically informed rule-of-mixtures. This multi-scale model is designed to include the effect of the carbon nanotubes on the constitutive properties of the lamina. It included concepts from the molecular dynamics/equivalent continuum methods, micromechanics, and the strength of materials. Within the model both the nanotube volume fraction and nanotube distribution were varied. It was found that for a lamina with 60% carbon fiber volume fraction, the Young's modulus in the fiber direction varied with changes in the nanotube distribution, from 138.8 to 140 GPa with nanotube volume fractions ranging from 0.0001 to 0.0125. The presence of nanotube near the surface of the carbon fiber is therefore expected to have a small, but positive, effect on the constitutive properties of the lamina.

Frankland, Sarah-Jane V.; Roddick, Jaret C.; Gates, Thomas S.

2005-01-01

127

Minimally Invasive Dentistry  

MedlinePLUS

... to your desktop! more... What Is Minimally Invasive Dentistry? Article Chapters What Is Minimally Invasive Dentistry? Minimally ... techniques. Reviewed: January 2012 Related Articles: Minimally Invasive Dentistry Minimally Invasive Veneers Dramatically Change Smiles What Patients ...

128

Significance of host cell kinases in herpes simplex virus type 1 egress and lamin-associated protein disassembly from the nuclear lamina  

PubMed Central

The nuclear lamina is thought to be a steric barrier to the herpesvirus capsid. Disruption of the lamina accompanied by phosphorylation of lamina proteins is a conserved feature of herpesvirus infection. In HSV-1-infected cells, protein kinase C (PKC) alpha and delta isoforms are recruited to the nuclear membrane and PKC delta has been implicated in phosphorylation of emerin and lamin B. We tested two critical hypotheses about the mechanism and significance of lamina disruption. First, we show that chemical inhibition of all PKC isoforms reduced viral growth five-fold and inhibited capsid egress from the nucleus. However, specific inhibition of either conventional PKCs or PKC delta does not inhibit viral growth. Second, we show hyperphosphorylation of emerin by viral and cellular kinases is required for its disassociation from the lamina. These data support hypothesis that phosphorylation of lamina components mediates lamina disruption during HSV nuclear egress.

Leach, Natalie R.; Roller, Richard J.

2010-01-01

129

Sensitivity of the coefficients of thermal expansion of selected graphite reinforced composite laminates to lamina thermoelastic properties  

NASA Technical Reports Server (NTRS)

An analytical study of the sensitivity of the laminate coefficient of thermal expansion, CTE, to changes in lamina elastic properties has been made. High modulus graphite/epoxy (P75/934, P100/934, P120/934), graphite/aluminum (P100/Al), and graphite/glass (HMS/Gl) composite materials were considered in quasi-isotropic, low thermal stress, and 'near-zero' thermal expansion laminate configurations. The effects of a positive or negative 10 percent change in lamina properties on laminate CTE is strongly dependent upon both the composite material and the laminate configuration. A 10 percent change in all of the lamina properties had very little effect on the laminate CTE of the HMS/Gl composite laminates investigated. The sensitivity and direction of change in the laminate CTE of Gr/934 depended very strongly on the fiber properties. A 10 percent change in the lamina transverse CTE resulted in changes as large as 0.216 ppm/C in the laminate CTE of a quasi-isotropic Gr/934 laminate. No significant difference was observed in the sensitivity of the laminate CTE of the P100/934 and P120/934 composite materials due to changes in lamina properties. Large changes in laminate CTE can result from measured temperature and radiation effects on lamina properties.

Tompkins, S. S.; Funk, J. G.

1992-01-01

130

Age related changes in the non-collagenous components of the extracellular matrix of the human lamina cribrosa  

PubMed Central

AIMS—To investigate age related alterations in the non-collagenous components of the human lamina cribrosa.?METHODS—Fibronectin, elastin, and glial fibrillary acidic protein (GFAP) staining were assessed in young and old laminae cribrosae. An age range (7 days to 96 years) of human laminae cribrosae were analysed for lipid content (n=9), cellularity (n=28), total sulphated glycosaminoglycans (n=28), elastin content (n=9), and water content (n=56), using chloroform-methanol extraction, fluorimetry, the dimethylmethylene blue assay, and ion exchange chromatography, respectively.?RESULTS—Qualitatively, an increase in elastin and a decrease in fibronectin and GFAP were demonstrated when young tissue was compared with the elderly. Biochemical analysis of the ageing human lamina cribrosa demonstrated that elastin content increased from 8% to 28% dry tissue weight, total sulphated glycosaminoglycans decreased, and lipid content decreased from 45% to 25%. There were no significant changes in total cellularity or water content.?CONCLUSION—These alterations in composition may be indicative of the metabolic state of the lamina cribrosa as it ages, and may contribute to changes in mechanical integrity. Such changes may be implicated in the susceptibility of the elderly lamina cribrosa and also its response to glaucomatous optic neuropathy.??

Albon, J.; Karwatowski, W.; Easty, D.; Sims, T.; Duance, V.

2000-01-01

131

Absent smooth muscle actin immunoreactivity of the small bowel muscularis propria circular layer in association with chromosome 15q11 deletion in megacystis-microcolon-intestinal hypoperistalsis syndrome.  

PubMed

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS; OMIM%249210) is a rare and severe form of congenital intestinal and urinary dysfunction and malformation. Histologic studies suggest that the predominant intestinal manifestation is smooth muscle myopathy. Molecular observations have linked the disease to the neuronal nicotinic acetylcholine receptor (?AChR), namely the absence of a functional ?3 subunit of the ?AChR in patients with MMIHS. We describe a case of MMIHS in association with a de novo deletion of the proximal long arm of chromosome 15 (15q11.2). Histologic evaluation revealed an appropriate light microscopic appearance of both the circular and longitudinal layers of the small bowel muscularis propria. Immunohistochemical staining for smooth muscle actin, however, was selectively absent in the circular layer, demonstrating isolated absence in a unique and previously undescribed pattern. These observations raise the possibility that the proximal long arm of chromosome 15 (15q11) may be of clinical significance in MMIHS. PMID:20028211

Szigeti, Reka; Chumpitazi, Bruno P; Finegold, Milton J; Ranganathan, Sarangarajan; Craigen, William J; Carter, Beth A; Tatevian, Nina

2010-01-01

132

Endoscopic Ultrasound-Assisted Tunnel-Type Endoscopic Submucosal Dissection for the Treatment of Esophageal Tumors Arising in the Muscularis Propria (with video)  

PubMed Central

Objective: Esophageal tumors arising in the muscularis propria are difficult to be resected endoscopically using standard electro-surgical techniques, even the endoscopic submucosal dissection (ESD) technique appeared recently. Our purpose is to investigate the efficacy of endoscopic ultrasound (EUS)-assisted tunnel-type ESD for resection of these tumors. Methods: A total of 17 patients were included in this study. A standard endoscope was used. The submucosal tunnel was created with the triangle knife according to the standard ESD technique, about 5 cm proximal to the lesion. EUS was performed within the tunnel to detect the tumor, and then the tumor was separated both from the submucosal and the muscle layers. After the tumor was removed, several clips were used to close the mucosal defect. EUS was performed to evaluate the healing quality 1 week after the procedure. Result: In all the cases, the tumors were completely resected. Mean tumor size was 24.2 mm (12-50 mm) in diameter. The histo-logical diagnoses were leiomyoma (16/17) and gastrointestinal stromal tumor (GIST, 1/17). Subcutaneous emphysema was found in 2 patients after the procedure, but disappeared by the third day. No patients sustained perforation or developed significant hem-orrhage, and there were no other immediate severe complications after the procedure. The healing quality was satisfying in 16/17 patients evaluated by EUS 1 week after the procedure. No recurrence has been found during follow-up (mean 7 months, range 3-13 months). Conclusion: EUS-assisted tunnel-type ESD is effective and safe in treatment of esophageal tumors arising in the muscularis pro-pria.

Ge, Nan; Sun, Siyu; Wang, Sheng; Liu, Xiang; Wang, Guoxin; Guo, Jintao

2013-01-01

133

Invasive Plants  

NSDL National Science Digital Library

This presentation from ATEEC describes the ecological impact of six invasive plant species. A slide is provided with detailed information on the exotic bush honeysuckle, bull thistle, common buckthorn, Japanese honeysuckle, purple loosestrife and yellow starthistle. Habitat, management approaches, biology and spread are discussed for each. This document is provided as a PowerPoint file. This resource is free to download. Users must first create a login with ATEEC's website to access the file.

2013-06-10

134

Invasive Species  

NSDL National Science Digital Library

The Advanced Technology Environmental and Energy Center (ATEEC) presents this group of documents on invasive species. The materials include a webquest, an informational flyer, service standards, National Science Education Standards, and a guide for creating public service announcements. The materials are supplied in PDF format and would be useful for biology or ecology teachers. Users must download this resource for viewing, which requires a free log-in. There is no cost to download the item.

2011-02-11

135

Brassinolide-2,3-acetonide: a brassinolide-induced rice lamina joint inclination antagonist.  

PubMed

A novel chemical tool compound that is an antagonist of brassinolide (BL, 1)-induced rice lamina joint inclination was developed. Although 2-O-, 3-O-, 22-O-, or 23-O-methylation of BL causes a critical decrease in biological activity,(5) a crystal structure of the extracellular leucine-rich repeat (LRR) domain of BRASSINOSTEROID-INSENSITIVE I (BRI1) bound to BL(3,4) indicates that the loss of activity of the O-methylated BL may result from not only the low affinity to BRI1, but also from blocking the interaction with another BR signaling factor, a partner protein of BRI1 (e.g., BRI1-ASSOCIATED KINASE 1, BAK1). On the basis of this hypothesis we synthesized the BL 2,3-acetonide 2, the 22,23-acetonide 3, and the 2,3:22,23-diacetonide 4 to assess the possibility of 2-O- and 3-O- or/and 22-O- and 23-O-alkylated BL as an antagonist in BR signaling evoked by exogenously applied BL. The 2,3-acetonide 2 more strongly inhibited the lamina inclination caused by BL relative to the 22,23-acetonide 3, whereas the diacetonide 4 had no effect most likely due to its increased hydrophobicity. This suggested that the 2,3-hydroxyl groups of BL play a more significant role in the interaction with a BRI1 partner protein rather than BRI1 itself in rice lamina joint inclination. Taken together it was demonstrated that BL, the most potent agonist of BRI1, is transformed into an antagonist by functionalization of the 2,3-dihydroxyl groups as the acetonide. This finding opens the door to the potential development of a chemical tool that modulates protein-protein interactions in the BR signaling pathway to dissect the BR-dependent processes. PMID:23673217

Muto, Takuya; Todoroki, Yasushi

2013-07-15

136

Unilateral hyperplasia of lamina and spinous process of C6 vertebra: case report.  

PubMed

We report a 20-year-old male patient who was admitted to our emergency clinic after a traffic accident and who suffered from neck pain. Radiographic examination of the cervical spine showed hypertrophy of the left lamina and hypertrophy and elongation of the left spinous process of the sixth cervical vertebra (C6). A computed tomography scan revealed the associated schisis of the spinous process at the same level. Magnetic resonance imaging scan demonstrated no abnormality of the neural elements. The patient underwent a surgical operation due to persistent neck pain and the local aesthetic abnormality. PMID:22258285

Kazanci, Burak; Tehli, Ozkan; Adilay, Utku; Guclu, Bulent

2012-11-01

137

Cement invasion  

SciTech Connect

Damage from cement and cement filtrate has been a much discussed subject since set-through-and-perforate completions were first used. Historically, much of the discussion was similar to that for rotary drilling and drilling mud - it would be nice to prevent all damage, but in the real world, some damage must be tolerated to allow the operator to reap the benefits of cementing. The principal perceived formation damage due to cement invasion is seen by the operator as reducing production. The pure idealist requires full potential production under all alternatives, and would to complete all oil and gas wells free of any formation damage. The more practical idealist holds that damage would result in lower production with the completion method he prefers should be prevented. The pragmatic operator compares the cost of preventing damage to the cost of correcting the damage. Even an extremely high damage ratio is academic if the planned stimulation treatment eliminates the influence the cement invasion might have on production. Formations with permeability high enough to yield economical production without some sort of stimulation or cleanup treatment are unlikely to be subject to significant cement filtrate damage.

Sutton, D.L.

1988-09-01

138

Lamina-associated polypeptide (LAP)2? and nucleoplasmic lamins in adult stem cell regulation and disease.  

PubMed

A-type lamins are components of the lamina network at the nuclear envelope, which mediates nuclear stiffness and anchors chromatin to the nuclear periphery. However, A-type lamins are also found in the nuclear interior. Here we review the roles of the chromatin-associated, nucleoplasmic LEM protein, lamina-associated polypeptide 2? (LAP2?) in the regulation of A-type lamins in the nuclear interior. The lamin A/C-LAP2? complex may be involved in the regulation of the retinoblastoma protein-mediated pathway and other signaling pathways balancing proliferation and differentiation, and in the stabilization of higher-order chromatin organization throughout the nucleus. Loss of LAP2? in mice leads to selective depletion of the nucleoplasmic A-type lamin pool, promotes the proliferative stem cell phenotype of tissue progenitor cells, and delays stem cell differentiation. These findings support the hypothesis that LAP2? and nucleoplasmic lamins are regulators of adult stem cell function and tissue homeostasis. Finally, we discuss potential implications of this concept for defining the molecular disease mechanisms of lamin-linked diseases such as muscular dystrophy and premature aging syndromes. PMID:24374133

Gesson, Kevin; Vidak, Sandra; Foisner, Roland

2014-05-01

139

Electromechanical characterization of a single active structural fiber lamina for multifunctional composites  

NASA Astrophysics Data System (ADS)

Piezoelectric fiber composites (PFCs) are a new group of materials recently developed in order to overcome the fragile nature of monolithic piezoceramics. However, there are some practical limitations associated with these types of materials, namely the generally separate electrode makes them difficult to embed into composites and when imbedded the low tensile properties of the material and the abnormal geometry in comparison with traditional reinforcements lead to stress concentrations reducing the material's strength. To resolve the inadequacies of current PFCs, a novel active structural fiber (ASF) was developed that can be embedded in a composite material to perform sensing and actuation, in addition to providing load bearing functionality. The ASF combines the advantages of the high tensile modulus and strength of the traditional composite reinforcements as well as the sensing and actuation properties of piezoceramic materials. A micromechanics model based on the double inclusion approach and a finite element model were been developed to study the effective piezoelectric coupling coefficient of the ASF as well as the ASF lamina. In order to evaluate the performance of the ASF when embedded in a polymer matrix and validate the model's accuracy, single fiber lamina have been fabricated and characterized through testing with an atomic force microscope. The results of our testing demonstrate the accuracy of the model and show that ASF composites could lead to load bearing composites with electromechanical coupling greater than most pure piezoelectric materials.

Lin, Yirong; Sodano, Henry A.

2009-03-01

140

Protease inhibitor 15, a candidate gene for abdominal aortic internal elastic lamina ruptures in the rat.  

PubMed

The inbred Brown Norway (BN) rat develops spontaneous ruptures of the internal elastic lamina (RIEL) of the abdominal aorta (AA) and iliac arteries. Prior studies with crosses of the BN/Orl RJ (susceptible) and LOU/M (resistant) showed the presence of a significant QTL on chromosome 5 and the production of congenic rats proved the involvement of this locus. In this study, we further dissected the above-mentioned QTL by creating a new panel of LOU.BN(chr5) congenic and subcongenic lines and reduced the locus to 5.2 Mb. Then we studied 1,002 heterogeneous stock (HS) rats, whose phenotyping revealed a low prevalence and high variability for RIEL. High-resolution mapping in the HS panel detected the major locus on chromosome 5 (log P > 35) and refined it to 1.4 Mb. Subsequently, RNA-seq analysis on AA of BN, congenics, and LOU revealed expression differences for only protease inhibitor 15 (Pi15) gene and a putative long intergenic noncoding RNA (lincRNA) within the linkage region. The high abundance of lincRNA with respect to reduced Pi15 expression, in conjunction with exertion of longitudinal strain, may be related to RIEL, indicating the potential importance of proteases in biological processes related to defective aortic internal elastic lamina structure. Similar mechanisms may be involved in aneurysm initiation in the human AA. PMID:24790086

Falak, Samreen; Schafer, Sebastian; Baud, Amelie; Hummel, Oliver; Schulz, Herbert; Gauguier, Dominique; Hubner, Norbert; Osborne-Pellegrin, Mary

2014-06-15

141

Sodium depletion induces Fos immunoreactivity in circumventricular organs of the lamina terminalis.  

PubMed

Acute sodium depletion by peritoneal dialysis (PD) induces c-fos expression in the subfornical organ (SFO) and organum vasculosum laminae terminalis (OVLT), in conscious rats. Fos immunoreactive (Fos-ir) neurons detected by immunohistochemistry first appeared in these nuclei 60 min after PD, increased gradually in the next 4 h and remained high for 27 h following PD. Fos-ir cells were distributed throughout the body of SFO, being the core of the posterior sections preferentially activated, whereas Fos-ir neurons occurred around the periphery of OVLT (annular disposition). When rats were allowed to drink sodium salt (1.8% NaCl) 24 h after PD, there was a marked reversion of the c-fos expression in the OVLT and a comparatively smaller effect in the SFO. Intracerebroventricular infusion of hypertonic CSF (170 mM NaCl) from 30 min before and during 4 h after PD, significantly inhibited the c-fos expression in both nuclei. These results demonstrate that an acute body sodium deficit induces c-fos activity in SFO and OVLT neurons, indicating the special role of these structures in sodium balance regulation. They also show that the sodium-depletion-induced production of Fos in neurons of the lamina terminalis can be modulated by central or systemic reposition of sodium. PMID:7648263

Vivas, L; Pastuskovas, C V; Tonelli, L

1995-05-01

142

LAMINA: a tool for rapid quantification of leaf size and shape parameters  

PubMed Central

Background An increased understanding of leaf area development is important in a number of fields: in food and non-food crops, for example short rotation forestry as a biofuels feedstock, leaf area is intricately linked to biomass productivity; in paleontology leaf shape characteristics are used to reconstruct paleoclimate history. Such fields require measurement of large collections of leaves, with resulting conclusions being highly influenced by the accuracy of the phenotypic measurement process. Results We have developed LAMINA (Leaf shApe deterMINAtion), a new tool for the automated analysis of images of leaves. LAMINA has been designed to provide classical indicators of leaf shape (blade dimensions) and size (area), which are typically required for correlation analysis to biomass productivity, as well as measures that indicate asymmetry in leaf shape, leaf serration traits, and measures of herbivory damage (missing leaf area). In order to allow Principal Component Analysis (PCA) to be performed, the location of a chosen number of equally spaced boundary coordinates can optionally be returned. Conclusion We demonstrate the use of the software on a set of 500 scanned images, each containing multiple leaves, collected from a common garden experiment containing 116 clones of Populus tremula (European trembling aspen) that are being used for association mapping, as well as examples of leaves from other species. We show that the software provides an efficient and accurate means of analysing leaf area in large datasets in an automated or semi-automated work flow.

Bylesjo, Max; Segura, Vincent; Soolanayakanahally, Raju Y; Rae, Anne M; Trygg, Johan; Gustafsson, Petter; Jansson, Stefan; Street, Nathaniel R

2008-01-01

143

Lamina-Associated Polypeptide (LAP)2? and Other LEM Proteins in Cancer Biology.  

PubMed

The LEM proteins comprise a heterogeneous family of chromatin-associated proteins that share the LEM domain, a structural motif mediating interaction with the DNA associated protein, Barrier-to-Autointegration Factor (BAF). Most of the LEM proteins are integral proteins of the inner nuclear membrane and associate with the nuclear lamina, a structural scaffold of lamin intermediate filament proteins at the nuclear periphery, which is involved in nuclear mechanical functions and (hetero-)chromatin organization. A few LEM proteins, such as Lamina-associated polypeptide (LAP)2? and Ankyrin and LEM domain-containing protein (Ankle)1 lack transmembrane domains and localize throughout the nucleoplasm and cytoplasm, respectively. LAP2? has been reported to regulate cell proliferation by affecting the activity of retinoblastoma protein in tissue progenitor cells and numerous studies showed upregulation of LAP2? in cancer. Ankle1 is a nuclease likely involved in DNA damage repair pathways and single nucleotide polymorphisms in the Ankle1 gene have been linked to increased breast and ovarian cancer risk. In this review we describe potential mechanisms of the involvement of LEM proteins, particularly of LAP2? and Ankle1 in tumorigenesis and we provide evidence that LAP2? expression may be a valuable diagnostic and prognostic marker for tumor analyses. PMID:24563347

Brachner, Andreas; Foisner, Roland

2014-01-01

144

Lamina-associated polypeptide (LAP)2? and nucleoplasmic lamins in adult stem cell regulation and disease?  

PubMed Central

A-type lamins are components of the lamina network at the nuclear envelope, which mediates nuclear stiffness and anchors chromatin to the nuclear periphery. However, A-type lamins are also found in the nuclear interior. Here we review the roles of the chromatin-associated, nucleoplasmic LEM protein, lamina-associated polypeptide 2? (LAP2?) in the regulation of A-type lamins in the nuclear interior. The lamin A/C–LAP2? complex may be involved in the regulation of the retinoblastoma protein-mediated pathway and other signaling pathways balancing proliferation and differentiation, and in the stabilization of higher-order chromatin organization throughout the nucleus. Loss of LAP2? in mice leads to selective depletion of the nucleoplasmic A-type lamin pool, promotes the proliferative stem cell phenotype of tissue progenitor cells, and delays stem cell differentiation. These findings support the hypothesis that LAP2? and nucleoplasmic lamins are regulators of adult stem cell function and tissue homeostasis. Finally, we discuss potential implications of this concept for defining the molecular disease mechanisms of lamin-linked diseases such as muscular dystrophy and premature aging syndromes.

Gesson, Kevin; Vidak, Sandra; Foisner, Roland

2014-01-01

145

A particle image velocimetry study of the flow physics generated by a thin lamina oscillating in a viscous fluid  

NASA Astrophysics Data System (ADS)

In this paper, we study the flow physics produced by a thin rigid lamina oscillating in an otherwise quiescent viscous fluid. Particle image velocimetry (PIV) is used to extract the flow kinematics, which is, in turn, utilized to reconstruct the pressure distribution around the lamina through the integration of Navier-Stokes equations. The hydrodynamic loading experienced by the lamina is ultimately estimated from PIV data to investigate added mass and fluid damping phenomena. Experiments are conducted for varying Reynolds and Keulegan-Carpenter numbers to elucidate the relative weight of inertial, convective, and viscous phenomena on the resulting flow physics. In agreement with prior numerical studies, experimental results demonstrate that increasing the Reynolds and the Keulegan-Carpenter numbers results into the formation of coherent structures that are shed at the edges of the lamina and advected by the flow. This phenomenon is associated with nonlinearities in the hydrodynamic loading, whereby fluid damping is found to increase nonlinearly with the oscillation of the lamina.

Jalalisendi, Mohammad; Panciroli, Riccardo; Cha, Youngsu; Porfiri, Maurizio

2014-02-01

146

Interannual Variability of Ozone in the Winter Lower Stratosphere and the Relationship to Lamina and Irreversible Transport  

NASA Technical Reports Server (NTRS)

We use the high-resolution dynamic limb sounder (HIRDLS) high-vertical resolution ozone profiles in the northern hemisphere lower stratosphere to examine the meridional transport out of the tropics. We focus on February 2005.2007 when there are differences in the dynamical background in the lower stratosphere due to the states of the quasibiennial oscillation and polar vortex. HIRDLS data reveal a large number of low ozone laminae that have the characteristics of tropical air at midlatitudes. More laminae are observed in February in 2006 than in 2005 or 2007. Because laminae can form, move out of the tropics, and return to the tropics without mixing into the midlatitude ozone field, the number of laminae is not directly related to the net transport. We use equivalent latitude coordinates to discriminate between reversible and irreversible laminar transport. The equivalent latitude analysis shows greater irreversible transport between the tropics and lower midlatitudes in both 2005 and 2007 compared to 2006 despite the higher number of laminae observed in 2006. Our conclusion that there was more irreversible transport of tropical air into the lower midlatitudes in 2005 and 2007 is supported by equivalent length analysis of mixing using microwave limb sounder N2O measurements. This study shows that reversibility must be considered in order to infer the importance of lamination to net transport.

Olsen, Mark A.; Douglass, Anne R.; Schoeberl, Mark R.; Rodriquez, Jose M.; Yoshida, Yasuko

2010-01-01

147

Strength properties of glued laminated timber made from edge-glued laminae II: bending, tensile, and compressive strength of glued laminated timber  

Microsoft Academic Search

The purpose of this study was to investigate the strength properties of glued laminated timber composed of edge-glued laminae\\u000a and to investigate the influence of edge gluing on the strength properties. Glued laminated timber composed of multiple-grade\\u000a laminae (symmetrical composition, strength grade E95-F270, 10 laminations) was produced from karamatsu (Larix kaempferi) edge-glued laminae according to the Japanese Agricultural Standard. The

Yasushi Hiramatsu; Kiyohiko Fujimoto; Atsushi Miyatake; Kenta Shindo; Hirofumi Nagao; Hideo Kato; Hirofumi Ido

2011-01-01

148

British Invasion  

NSDL National Science Digital Library

This month marks the 35th anniversary of the Beatles' arrival in America, an event that sparked the "second British Invasion" of 1964-67. Soon after their historic appearance on the Ed Sullivan show, a string of British bands sought their fortune on the US pop charts, as American youths clamored for singles, clothes, and anything else hip and new from the old country. This new site from the Encyclopedia Brittanica offers brief histories of the influences, careers, and members of some of the principal British invaders, including the Beatles, the Who, the Rolling Stones, the Kinks, and the Hollies. Other resources include RealPlayer music clips, a section on London fashion with a movie of a 1966 Carnaby Street fashion show, band trading cards, and sections exploring the roots of British rock.

1999-01-01

149

Tonotopic morphometry of the lamina reticularis of the guinea pig cochlea with associated microstructures and related mechanical implications.  

PubMed

Morphometry of the lamina reticularis of the guinea pig cochlea was performed using scanning electron microscopy. Seventy-four geometrical parameters of the lamina reticularis, the bundles of stereocilia, and individual stereocilia, in all rows of hair cells and within the individual hair cells, were measured at ten equally spaced locations along the longitudinal direction of the cochlea. Variations of the parameters versus the longitudinal coordinate were statistically analyzed and fitted with polynomials (constant, linear, or quadratic). Our data show that a unique set of geometrical parameters of inner and outer hair cells is typical for every frequency-dependent position at the lamina reticularis. Morphology of the outer hair cell structures varies more than respective parameters of the inner hair cells. Mechanical modeling using the obtained geometrical parameters provides a novel glance at the mechanical characteristics with respect to the cochlear tonotopy. PMID:24165807

Yarin, Yury M; Lukashkin, Andrei N; Poznyakovskiy, Anton A; Meissner, Heike; Fleischer, Mario; Baumgart, Johannes; Richter, Claudia; Kuhlisch, Eberhard; Zahnert, Thomas

2014-02-01

150

[An intraosseous hemangioma in the perpendicular lamina of the ethmoid bone].  

PubMed

The incidence of intraosseous hemangiomas is very low. Most of them occur in adult females. The mandible,the zygoma,the maxilla, and the frontal and nasal bones are the areas of most frequent localization in the facial region. The intraosseous hemangioma is a benign, slowly growing,bony hard tumor causing facial deformity. It is diagnosed histologically. We report a case of an 18-year-old male with an intraosseous cavernous hemangioma located in the perpendicular lamina of the ethmoid bone. Intraosseous hemangioma often has characteristic signs on a CT scan, with either coarsened trabeculae lying adjacent to the vascular channels or multifocal lytic areas creating a honeycomb pattern. Because of the age of the patient we considered a midline granuloma and a chondrosarcoma. The therapy of choice is surgical excision; radiation is done in exceptional cases only. PMID:12589420

Graumüller, S; Terpe, H; Hingst, V; Dommerich, S; Pau, H W

2003-02-01

151

Multiscale Finite Element Modeling of the Lamina Cribrosa Microarchitecture in the Eye  

PubMed Central

In this paper, we describe a new method for constructing macro-scale models of the posterior pole of the eye to investigate the role of intraocular pressure in the development and progression of glaucoma. We also describe a method and present results from micro-scale finite element models of the lamina cribrosa microarchitecture that are derived from parent macro-scale continuum models using a novel multiscale substructuring approach. The laminar micro-scale models capture the biomechanical behavior of the laminar trabeculae in a way that cannot be estimated using macro-scale techniques, and predict much higher stresses and strains than those calculated within macro-scale models of the coincident region in the same eye.

Downs, J. Crawford; Roberts, Michael D.; Burgoyne, Claude F.; Hart, Richard T.

2012-01-01

152

Functional coupling between the extracellular matrix and nuclear lamina by Wnt signaling in Progeria  

PubMed Central

The segmental premature aging disease, Hutchinson-Gilford Progeria (HGPS) is caused by a truncated and farnesylated form of Lamin A. In a mouse model for HGPS, a similar Lamin A variant causes the proliferative arrest and death of post-natal but not embryonic fibroblasts. Arrest is due to an inability to produce a functional extracellular matrix (ECM), as growth on normal ECM rescues proliferation. The defects are associated with inhibition of canonical Wnt signaling, due to reduced nuclear localization and transcriptional activity of Lef1, but not Tcf4, in both mouse and human progeric cells. Defective Wnt signaling, affecting ECM synthesis, maybe critical to the etiology of HGPS as mice exhibit skeletal defects and apoptosis in major blood vessels proximal to the heart. These results establish a functional link between the nuclear envelope/lamina and the cell surface/ECM and may provide insights into the role of Wnt signaling and the ECM in aging.

Hernandez, Lidia; Roux, Kyle J.; Wong, Esther Sook Min; Mounkes, Leslie C.; Mutalif, Rafidah; Navasankari, Raju; Rai, Bina; Cool, Simon; Jeong, Jae-Wook; Wang, Honghe; Lee, Hyun-Shik; Kozlov, Serguei; Grunert, Martin; Keeble, Thomas; Jones, C. Michael; Meta, Margarita D.; Young, Stephen G.; Daar, Ira O.; Burke, Brian; Perantoni, Alan O.; Stewart, Colin L.

2010-01-01

153

Cerebrospinal fluid pressure and glaucoma: regulation of trans-lamina cribrosa pressure.  

PubMed

Increased trans-lamina cribrosa pressure difference (TLCPD), the difference of intraocular pressure (IOP) and orbital cerebrospinal fluid pressure (CSF-P), has been investigated as a possible risk factor in glaucoma pathogenesis. In fact, lower CSF-P in the setting of normal IOP has been implicated as a potential risk factor for normal tension glaucoma. Increased TLCPD has been associated with decreased neuroretinal rim area and increased visual field defects. Furthermore, dysregulation of systemic blood pressure has been associated with changes in IOP. Recent studies have also suggested that increased body mass index (BMI) is associated with decreased prevalence of glaucoma, which may be due to an increased CSF-P with increased BMI found in many studies. Given the interaction of various pressures, their role in glaucoma pathophysiology has come under investigation and warrants further study in order to better understand the aetiology and progression of glaucoma. PMID:24307714

Marek, Brian; Harris, Alon; Kanakamedala, Priyanka; Lee, Eric; Amireskandari, Annahita; Carichino, Lucia; Guidoboni, Giovanna; Tobe, Leslie Abrams; Siesky, Brent

2014-06-01

154

Lamina-associated polypeptide 1: protein interactions and tissue-selective functions.  

PubMed

Mutations in genes encoding widely expressed nuclear envelope proteins often lead to diseases that manifest in specific tissues. Lamina-associated polypeptide 1 (LAP1) is an integral protein of the inner nuclear membrane that is expressed in most cells and tissues. Within the nuclear envelope, LAP1 interacts physically with lamins, torsinA and emerin, suggesting it may serve as a key node for transducing signals across the inner nuclear membrane. Indeed, recent in vivo studies in genetically modified mice strongly support functional links between LAP1 and both torsinA (in neurons) and emerin (in muscle). These studies suggest that tissue-selective diseases caused by mutations in genes encoding nuclear envelope proteins may result, at least in part, from the selective disruption of discrete nuclear envelope protein complexes. PMID:24508913

Shin, Ji-Yeon; Dauer, William T; Worman, Howard J

2014-05-01

155

Disruption of basal lamina components in neuromotor synapses of children with spastic quadriplegic cerebral palsy.  

PubMed

Cerebral palsy (CP) is a static encephalopathy occurring when a lesion to the developing brain results in disordered movement and posture. Patients present with sometimes overlapping spastic, athetoid/dyskinetic, and ataxic symptoms. Spastic CP, which is characterized by stiff muscles, weakness, and poor motor control, accounts for ?80% of cases. The detailed mechanisms leading to disordered movement in spastic CP are not completely understood, but clinical experience and recent studies suggest involvement of peripheral motor synapses. For example, it is recognized that CP patients have altered sensitivities to drugs that target neuromuscular junctions (NMJs), and protein localization studies suggest that NMJ microanatomy is disrupted in CP. Since CP originates during maturation, we hypothesized that NMJ disruption in spastic CP is associated with retention of an immature neuromotor phenotype later in life. Scoliosis patients with spastic CP or idiopathic disease were enrolled in a prospective, partially-blinded study to evaluate NMJ organization and neuromotor maturation. The localization of synaptic acetylcholine esterase (AChE) relative to postsynaptic acetylcholine receptor (AChR), synaptic laminin ?2, and presynaptic vesicle protein 2 (SV2) appeared mismatched in the CP samples; whereas, no significant disruption was found between AChR and SV2. These data suggest that pre- and postsynaptic NMJ components in CP children were appropriately distributed even though AChE and laminin ?2 within the synaptic basal lamina appeared disrupted. Follow up electron microscopy indicated that NMJs from CP patients appeared generally mature and similar to controls with some differences present, including deeper postsynaptic folds and reduced presynaptic mitochondria. Analysis of maturational markers, including myosin, syntrophin, myogenin, and AChR subunit expression, and telomere lengths, all indicated similar levels of motor maturation in the two groups. Thus, NMJ disruption in CP was found to principally involve components of the synaptic basal lamina and subtle ultra-structural modifications but appeared unrelated to neuromotor maturational status. PMID:23976945

Robinson, Karyn G; Mendonca, Janet L; Militar, Jaimee L; Theroux, Mary C; Dabney, Kirk W; Shah, Suken A; Miller, Freeman; Akins, Robert E

2013-01-01

156

Disruption of Basal Lamina Components in Neuromotor Synapses of Children with Spastic Quadriplegic Cerebral Palsy  

PubMed Central

Cerebral palsy (CP) is a static encephalopathy occurring when a lesion to the developing brain results in disordered movement and posture. Patients present with sometimes overlapping spastic, athetoid/dyskinetic, and ataxic symptoms. Spastic CP, which is characterized by stiff muscles, weakness, and poor motor control, accounts for ?80% of cases. The detailed mechanisms leading to disordered movement in spastic CP are not completely understood, but clinical experience and recent studies suggest involvement of peripheral motor synapses. For example, it is recognized that CP patients have altered sensitivities to drugs that target neuromuscular junctions (NMJs), and protein localization studies suggest that NMJ microanatomy is disrupted in CP. Since CP originates during maturation, we hypothesized that NMJ disruption in spastic CP is associated with retention of an immature neuromotor phenotype later in life. Scoliosis patients with spastic CP or idiopathic disease were enrolled in a prospective, partially-blinded study to evaluate NMJ organization and neuromotor maturation. The localization of synaptic acetylcholine esterase (AChE) relative to postsynaptic acetylcholine receptor (AChR), synaptic laminin ?2, and presynaptic vesicle protein 2 (SV2) appeared mismatched in the CP samples; whereas, no significant disruption was found between AChR and SV2. These data suggest that pre- and postsynaptic NMJ components in CP children were appropriately distributed even though AChE and laminin ?2 within the synaptic basal lamina appeared disrupted. Follow up electron microscopy indicated that NMJs from CP patients appeared generally mature and similar to controls with some differences present, including deeper postsynaptic folds and reduced presynaptic mitochondria. Analysis of maturational markers, including myosin, syntrophin, myogenin, and AChR subunit expression, and telomere lengths, all indicated similar levels of motor maturation in the two groups. Thus, NMJ disruption in CP was found to principally involve components of the synaptic basal lamina and subtle ultra-structural modifications but appeared unrelated to neuromotor maturational status.

Militar, Jaimee L.; Theroux, Mary C.; Dabney, Kirk W.; Shah, Suken A.; Miller, Freeman; Akins, Robert E.

2013-01-01

157

Heat treatment of retinal pigment epithelium induces production of elastic lamina components and antiangiogenic activity  

PubMed Central

Age-related macular degeneration (AMD) is the leading cause of blindness in the Western world. In advanced AMD, new vessels from choriocapillaris (CC) invade through the Bruch's membrane (BrM) into the retina, forming choroidal neovascularization (CNV). BrM, an elastic lamina that is located between the retinal pigment epithelium (RPE) and CC, is thought to act as a physical and functional barrier against CNV. The BrM of patients with early AMD are characterized by decreased levels of antiangiogenic factors, including endostatin, thrombospondin-1 (TSP-1), and pigment epithelium-derived factor (PEDF), as well as by degeneration of the elastic layer. Motivated by a previous report that heat increases elastin expression in human skin, we examined the effect of heat on human ARPE-19 cell production of BrM components. Heat treatment stimulated the production of BrM components, including TSP-1, PEDF, and tropoelastin in vitro and increased the antiangiogenic activity of RPE measured in a mouse corneal pocket assay. The effect of heat on experimental CNV was investigated by pretreating the retina with heat via infrared diode laser prior to the induction of CNV. Heat treatment blocked the development of experimental CNV in vivo. These findings suggest that heat treatment may restore BrM integrity and barrier function against new vessel growth.—Sekiyama, E., Saint-Geniez, M., Yoneda, K., Hisatomi, T., Nakao, S., Walshe, T. E., Maruyama, K., Hafezi-Moghadam, A., Miller, J. W., Kinoshita, S., D'Amore, P. A. Heat treatment of retinal pigment epithelium induces production of elastic lamina components and anti-angiogenic activity.

Sekiyama, Eiichi; Saint-Geniez, Magali; Yoneda, Kazuhito; Hisatomi, Toshio; Nakao, Shintaro; Walshe, Tony E.; Maruyama, Kazuichi; Hafezi-Moghadam, Ali; Miller, Joan W.; Kinoshita, Shigeru; D'Amore, Patricia A.

2012-01-01

158

Retinoblastoma: correlation of invasion of the optic nerve and choroid with prognosis and metastases.  

PubMed Central

The histological sections of 74 retinoblastoma patients were reviewed. The extent of optic nerve invasion was correlated with choroidal/scleral extension. Choroidal invasion carries 100% survival provided that the sclera, iris, and whole optic nerve are not also involved. Invasion of the optic nerve beyond the lamina cribrosa also carries 100% survival provided that the resection line is free and that invasion does not involve the sclera or iris. Plentiful rosettes were usually found in those tumours that had not extended beyond the choroid or as far as the resection line of the optic nerve and were therefore associated with a good prognosis. The absence of rosettes did not necessarily indicate a poor prognosis. The site of metastases was related to optic nerve and scleral/extrascleral extension. The various systems of staging retinoblastoma are compared, and a new system is proposed to cover the whole spectrum of the disease and to offer a reliable guide to prognosis and treatment.

Stannard, C; Lipper, S; Sealy, R; Sevel, D

1979-01-01

159

The Lamina Rostralis: Modification of Concepts Concerning the Anatomy, Embryology, and MR Appearance of the Rostrum of the Corpus Callosum  

Microsoft Academic Search

PURPOSE: To study the anatomy and embryology of the lamina rostralis, and to determine whether the rostrum is, as frequently stated, the last section of the corpus callosum to develop. METHODS: The rostrum was analyzed in dissected adult brains and on MR studies in 300 patients with a normal corpus callosum and in 84 patients with a hypogenetic corpus callosum.

E. Leon Kier; Charles L. Truwit

160

Loss of Function of a Rice brassinosteroid insensitive1 Homolog Prevents Internode Elongation and Bending of the Lamina Joint  

Microsoft Academic Search

Brassinosteroids (BRs) are plant growth-promoting natural products required for plant growth and development. Phys- iological studies have demonstrated that exogenous BR, alone or in combination with auxin, enhance bending of the lamina joint of rice. However, little is known about the function of endogenous BR in rice or other grass species. We re- port here the phenotypical and molecular characterization

Chizuko Yamamuro; Yoshihisa Ihara; Xiong Wu; Takahiro Noguchi; Shozo Fujioka; Suguru Takatsuto; Motoyuki Ashikari; Hidemi Kitano; Makoto Matsuoka

2000-01-01

161

Neutrophil Migration through Preexisting Holes in the Basal Laminae of Alveolar Capillaries and Epithelium during Streptococcal Pneumonia  

Microsoft Academic Search

The purpose of this study was to determine whether or not there are preexisting holes in the endothelial and epithelial basal laminae of alveolar walls and to determine the path taken by neutrophils as they migrate from the capillaries to the airspace of the alveoli during inflammation. Using transmission electron microscopy and serial thin sections of normal rabbit and mouse

David C. Walker; Ali R. Behzad; Fanny Chu

1995-01-01

162

Lamina properties, lay-up configurations and loading conditions for a range of fibre-reinforced composite laminates  

Microsoft Academic Search

This paper gives details of the input data and a description of the laminates provided to all participants in an exercise to predict the strength of composite laminates. The input data include the elastic constants and the stress\\/strain curves for four unidirectional laminae and their constituents. Six types of laminates, chosen for the analysis, are described together with the lay-up,

P. D. Soden; M. J. Hinton; A. S. Kaddour

1998-01-01

163

The development of the reticular lamina in the hamster: An examination of transitory features and their functional roles  

Microsoft Academic Search

This study examines the development of the reticular lamina in the Syrian golden hamster postriatally from birth to adulthood at 2 day intervals using the scanning electron microscope. During this period, numerous transitory features emerged whose roles were concerned primarily with the development of the tectorial membrane (TM). The principal findings were as follows. (1) The surface of the developing

James A Kaltenbach; Pamela R Falzarano

1997-01-01

164

COMBATE DE LA PUDRICION PEDU.NCULAR DEL MANGO CAUSADA POR Botryodiplodia theobromae PAT. MEDIANTE EL MANTENIMIENTO DE LOS PEDICELOS Y EL DESLECHADO SOBRE LAMINAS  

Microsoft Academic Search

Se detennino el efecto de hacer el desle- Cultural practices to control of mango chado de frutos de mango en el suelo y sobre una stem-end rot caused by Botryodiplodia theo- lamina de hierro galvanizado (lamina de zinc), bromaes Pat. The following practices were eva- eliminando 0 dejando el pedunculo para ambos luated for the control of stem-end rot of

Eugenia Gonzalez; Gerardina Umana; Luis Felipe Arauz

165

Coactivation of different neurons within an isofrequency lamina of the inferior colliculus elicits enhanced auditory cortical activation.  

PubMed

The phenomenal success of the cochlear implant (CI) is attributed to its ability to provide sufficient temporal and spectral cues for speech understanding. Unfortunately, the CI is ineffective for those without a functional auditory nerve or an implantable cochlea required for CI implementation. As an alternative, our group developed and implanted in deaf patients a new auditory midbrain implant (AMI) to stimulate the central nucleus of the inferior colliculus (ICC). Although the AMI can provide frequency cues, it appears to insufficiently transmit temporal cues for speech understanding. The three-dimensional ICC consists of two-dimensional isofrequency laminae. The single-shank AMI only stimulates one site in any given ICC lamina and does not exhibit enhanced activity (i.e., louder percepts or lower thresholds) for repeated pulses on the same site with intervals <2-5 ms, as occurs for CI pulse or acoustic click stimulation. This enhanced activation, related to short-term temporal integration, is important for tracking the rapid temporal fluctuations of a speech signal. Therefore, we investigated the effects of coactivation of different regions within an ICC lamina on primary auditory cortex activity in ketamine-anesthetized guinea pigs. Interestingly, our findings reveal an enhancement mechanism for integrating converging inputs from an ICC lamina on a fast scale (<6-ms window) that is compromised when stimulating just a single ICC location. Coactivation of two ICC regions also reduces the strong and long-term (>100 ms) suppressive effects induced by repeated stimulation of just a single location. Improving AMI performance may require at least two shanks implanted along the tonotopic gradient of the ICC that enables coactivation of multiple regions along an ICC lamina with the appropriate interstimulus delays. PMID:22623485

Calixto, Roger; Lenarz, Minoo; Neuheiser, Anke; Scheper, Verena; Lenarz, Thomas; Lim, Hubert H

2012-08-01

166

Computer simulation of wound closure in epithelial tissues: cell-basal-lamina adhesion.  

PubMed

The mechanism of wound closure in epithelial tissues, i.e., cell monolayer sheets, is investigated through computer simulations. A wound means an area in which some cells have been removed from the normal tissue. The vertex dynamics cell model [T. Nagai and H. Honda, Philos. Mag. B 81, 699 (2001)], which describes morphogenesis of epithelial tissues using the concepts of statistical physics, is modified and applied to the closure of small wounds without mitosis. It is shown that cell-basal-lamina adhesion governs the wound closure competing with cell-cell adhesion and cell elasticity. The simulation results reproduce the actual wound closure process qualitatively and partly quantitatively. The closing proceeds with the translation of the edges of wound polygons toward the wound center and the intermittent reduction in the number of polygon edges. Over time, the process leads to an exponential decrease in the wound area. A shape factor is introduced to describe the wound shape quantitatively and is used to examine the time variation thereof. A method for determining model parameters by comparison with the experiments is given. PMID:20365186

Nagai, Tatsuzo; Honda, Hisao

2009-12-01

167

Samp1 is functionally associated with the LINC complex and A-type lamina networks.  

PubMed

The transmembrane inner nuclear membrane (INM) protein Samp1 is required for anchoring centrosomes near the nuclei. Using high-resolution fluorescence microscopy we show that Samp1 is distributed in a distinct and characteristic pattern in the nuclear envelope (NE), where it partially colocalizes with the LINC complex protein Sun1. By studying the localization of Samp1 deletion mutants and fusion proteins, we conclude that the cysteine-rich N-terminal half of Samp1 is nucleoplasmically exposed and is responsible for targeting to the INM. It contains four conserved CxxC motifs with the potential to form zinc fingers. The distribution of cysteine-to-alanine substitution mutants, designed to prevent zinc finger formation, showed that NE localization of Samp1 depends on intact CxxC motifs. Overexpression of Samp1 zinc finger mutants produced an abnormal dominant phenotype characterized by disrupted organization of a selective subset NE proteins, including emerin, Sun1, endogenous Samp1 and, in some cases, lamin A/C, but not lamin B, Sun2 or nucleoporins. Silencing of Samp1 expression showed that emerin depends on Samp1 for its correct localization in the NE. Our results demonstrate that Samp1 is functionally associated with the LINC complex protein Sun1 and proteins of the A-type lamina network. PMID:21610090

Gudise, Santhosh; Figueroa, Ricardo A; Lindberg, Robert; Larsson, Veronica; Hallberg, Einar

2011-06-15

168

Reproducibility of In-Vivo OCT Measured Three-Dimensional Human Lamina Cribrosa Microarchitecture  

PubMed Central

Purpose To determine the reproducibility of automated segmentation of the three-dimensional (3D) lamina cribrosa (LC) microarchitecture scanned in-vivo using optical coherence tomography (OCT). Methods Thirty-nine eyes (8 healthy, 19 glaucoma suspects and 12 glaucoma) from 49 subjects were scanned twice using swept-source (SS?) OCT in a 3.5×3.5×3.64 mm (400×400×896 pixels) volume centered on the optic nerve head, with the focus readjusted after each scan. The LC was automatically segmented and analyzed for microarchitectural parameters, including pore diameter, pore diameter standard deviation (SD), pore aspect ratio, pore area, beam thickness, beam thickness SD, and beam thickness to pore diameter ratio. Reproducibility of the parameters was assessed by computing the imprecision of the parameters between the scans. Results The automated segmentation demonstrated excellent reproducibility. All LC microarchitecture parameters had an imprecision of less or equal to 4.2%. There was little variability in imprecision with respect to diagnostic category, although the method tends to show higher imprecision amongst healthy subjects. Conclusion The proposed automated segmentation of the LC demonstrated high reproducibility for 3D LC parameters. This segmentation analysis tool will be useful for in-vivo studies of the LC.

Wang, Bo; Nevins, Jessica E.; Nadler, Zach; Wollstein, Gadi; Ishikawa, Hiroshi; Bilonick, Richard A.; Kagemann, Larry; Sigal, Ian A.; Grulkowski, Ireneusz; Liu, Jonathan J.; Kraus, Martin; Lu, Chen D.; Hornegger, Joachim; Fujimoto, James G.; Schuman, Joel S.

2014-01-01

169

Basal lamina secreted by MDCK cells has size- and charge-selective properties  

PubMed Central

The role electrical charge plays in determining glomerular permeability to macromolecules remains unclear. If the glomerular basement membrane (GBM) has any significant role in permselectivity, physical principles would suggest a negatively charged GBM would reject similarly charged more than neutral species. However, recent in vivo studies with negative and neutral glomerular probes showed the opposite. Whether this observation is due to unique characteristics of the probes used or is a general physiological phenomenon remains to be seen. The goal of this study was to use the basement membrane deposited by Madin-Darby canine kidney epithelial cells as a simple model of a biologically derived, negatively charged filter to evaluate size- and charge-based sieving properties. Fluorescein isothiocyanate-labeled carboxymethylated Ficoll 400 (FITC-CM Ficoll 400) and amino-4-methyl-coumarin-labeled Ficoll 400 (AMC Ficoll 400) were used as negatively charged and neutral tracer molecules, respectively, during pressure-driven filtration. Streaming potential measurement indicated the presence of fixed, negative charge in the basal lamina. The sieving coefficient for neutral Ficoll 400 decreased by ?0.0013 for each 1-? increment in solute radius, compared with a decrease of 0.0023 per ? for the anionic Ficoll 400. In this system, molecular charge played a significant role in determining the sieving characteristics of the membrane, pointing to solute charge as a potential contributor to GBM permselectivity.

Ferrell, Nicholas; Groszek, Joseph; Li, Lingyan; Smith, Ross; Butler, Robert S.; Zorman, Christian A.; Roy, Shuvo

2011-01-01

170

Minimally Invasive Surgery  

MedlinePLUS

... of the American Society for Reproductive Medicine Minimally invasive surgery This fact sheet was developed in collaboration ... as one procedure. Some common types of minimally invasive surgery are listed below: • Laparoscopy involves placing a ...

171

Invasive Lionfish Removal  

USGS Multimedia Gallery

In September 2009, divers carefully capture an invasive red lionfish (Pterois volitans) found near the coast of North Carolina. Invasive lionfish are now established in the hard bottom habitats of North Carolina's coast, where they are abundant....

2009-12-15

172

SFRSF: Invasive Exotic Species  

NSDL National Science Digital Library

This South Florida Restoration Science Forum (SFRSF) site discusses the problem of invasive exotic species in southern Florida. Topics covered include what invasive species are, where they come from, where they exist at this time, what controls them, their effect on restoration, the use of natural enemies to tame some invasive plants, and what can be done about other invasive animals and plants. There are links provided for additional information.

173

Impact surface fractures of glass-fiber\\/epoxy lamina-coated glass plates by small steel-ball  

Microsoft Academic Search

Fiber orientation effects on the impact surface fracture of glass plates coated with a glass-fiber\\/epoxy lamina layer were investigated using a small-diameter steel-ball impact experiment. Four kinds of materials were used: soda-lime glass plates, unidirectional glass-fiber\\/epoxy layer (one ply, two plies) coated glass plates, crossed glass-fiber\\/epoxy layer (only two plies) coated glass plates. The maximum stress and absorbed fracture energy

Nak-Sam Choi; Jae-Young Chang; Seung-Bum Kwak; Ja-Uk Gu

2010-01-01

174

Diurnal and seasonal changes of leaf lamina hydraulic conductance in bur oak ( Quercus macrocarpa ) and trembling aspen ( Populus tremuloides )  

Microsoft Academic Search

The aim of this study was to examine the diurnal and seasonal variations in the sensitivity of leaf lamina (K\\u000a lam) hydraulic conductance to irradiance in bur oak (Quercus macrocarpa Michx.) and trembling aspen (Populus tremuloides Michx.), which vary in their responses of K\\u000a lam to irradiance. K\\u000a lam was determined using the high-pressure method and the measurements were carried

Mihaela C. VoicuJanusz; Janusz J. Zwiazek

2011-01-01

175

Neurons and glial cells of the rat organum vasculosum laminae terminalis directly respond to lipopolysaccharide and pyrogenic cytokines  

Microsoft Academic Search

During systemic immune challenge, the organum vasculosum laminae terminalis (OVLT) with its dense vascularization by fenestrated capillaries lacking blood–brain barrier function allows direct access of circulating pyrogens to brain tissue located in close vicinity to the preoptic area. We aimed to analyze direct responses of OVLT cells to exposure to lipopolysaccharide (LPS) and fibroblast-stimulating lipopeptide-1 (FSL-1) or the cytokines tumor

Daniela Ott; Jolanta Murgott; Sandra Rafalzik; Florian Wuchert; Babette Schmalenbeck; Joachim Roth; Rüdiger Gerstberger

2010-01-01

176

Antinociceptive action of oxytocin involves inhibition of potassium channel currents in lamina II neurons of the rat spinal cord  

PubMed Central

Background Growing evidence in the literature shows that oxytocin (OT) has a strong spinal anti-nociceptive action. Oxytocinergic axons originating from a subpopulation of paraventricular hypothalamic neurons establish synaptic contacts with lamina II interneurons but little is known about the functional role of OT with respect to neuronal firing and excitability. Results Using the patch-clamp technique, we have recorded lamina II interneurons in acute transverse lumbar spinal cord slices of rats (15 to 30 days old) and analyzed the OT effects on action potential firing ability. In the current clamp mode, we found that bath application of a selective OT-receptor agonist (TGOT) reduced firing in the majority of lamina II interneurons exhibiting a bursting firing profile, but never in those exhibiting a single spike discharge upon depolarization. Interestingly, OT-induced reduction in spike frequency and increase of firing threshold were often observed, leading to a conversion of the firing profile from repetitive and delayed profiles into phasic ones and sometimes further into single spike profile. The observed effects following OT-receptor activation were completely abolished when the OT-receptor agonist was co-applied with a selective OT-receptor antagonist. In current and voltage clamp modes, we show that these changes in firing are strongly controlled by voltage-gated potassium currents. More precisely, transient IA currents and delayed-rectifier currents were reduced in amplitude and transient IA current was predominantly inactivated after OT bath application. Conclusion This effect of OT on the firing profile of lamina II neurons is in good agreement with the antinociceptive and analgesic properties of OT described in vivo.

2009-01-01

177

Fine-scale study of a thick stratospheric ozone lamina at the edge of the southern subtropical barrier  

NASA Astrophysics Data System (ADS)

A large-scale transport event resulting in a thick ozone lamina originating from midlatitudes is observed in the tropical stratosphere over Reunion island (55°E, 21°S). This isentropic transport was detected from stratospheric balloon-borne ozone measurements that showed the occurrence of the lamina and was investigated using different tools based on Ertel's potential vorticity (Epv) analyses. An original software (DYBAL) using surface coordinate and the equivalent length of Epv contours as diagnostic tools in conjunction with high-resolution outputs from an Epv advection model MIMOSA allows us to specify the origin of the lamina. The results indicate that a broad layer of stratospheric air was isentropically advected from midlatitudes across the southern edge of tropical reservoir and reached Reunion island on 12 July 2000. In addition, Eliassen-Palm's flux vectors, calculated from ECMWF analysis, show that planetary wave activity was quite large during that time period, with wave-breaking occurring around 30 km, and could have driven that exchange. In contrast with analyses of filamentation events based on model and satellite data, the present study focuses on a fine-scale vertical survey from in situ measurements. The filament reported in this paper is characterized by a large vertical extension and is located around the maximum of ozone concentration in the tropical stratosphere (600 K). The analysis of such events, poorly documented in the tropics, could complement satellite studies and contribute to a better determination of the transport between the tropics and the midlatitudes.

Portafaix, Thierry; Morel, BéAtrice; Bencherif, Hassan; Baldy, Serge; Godin-Beekmann, Sophie; Hauchecorne, Alain

2003-03-01

178

Predictable Imaging Signs of Cauda Equina Entrapment in Thoracolumbar and Lumbar Burst Fractures with Greenstick Lamina Fractures  

PubMed Central

Study Design A retrospective study. Purpose The aim of present study was to investigate imaging findings suggestive of cauda equina entrapment in thoracolumbar and lumbar burst fractures. Overview of Literature Burst fractures with cauda equina entrapment can cause neurologic deterioration during surgery. However, dural tears and cauda equina entrapment are very difficult to diagnose clinically or radiographically before surgery. Methods Twenty-three patients who underwent spinal surgery for thoracolumbar or lumbar burst fractures were enrolled in this study. In magnetic resonance imaging T2-weighted images of the transverse plane, we defined cauda equina notch sign (CENS) as a v-shaped image that entrapped cauda equina gathers between lamina fractures. We evaluated the fractured spine by using CENS and lamina fractures and the rate of available space for the spinal canal at the narrowest portion of the burst fracture level. We classified patients into entrapment group or non-entrapment group, based on whether cauda equina entrapment existed. Results Lamina fractures were detected in 18 (78.3%) and CENS were detected in 6 (26.1%) of 23 burst-fracture patients. Cauda equina entrapment existed in all the patients with CENS. In addition, the rate of available space for the spinal canal increased according to logistic regression. The size of the retropulsed fragment in the spinal canal was the most reliable of all the factors, suggesting cauda equina entrapment. Conclusions CENS was the most predictable sign of cauda equina entrapment associated with burst fractures.

Yoshiiwa, Toyomi; Kodera, Ryuzo; Kawano, Masanori; Tsumura, Hiroshi

2014-01-01

179

What is relationship between the medial preoptic area, the organum vasculosum of the lamina terminalis and Kallmann syndrome?  

PubMed

The medial preoptic area is a structure located in the hypothalamic anteroventral third ventricle region, and is closely related to the olfactory brain development and sexual differentiation of the brain. The medial preoptic area surrounds the organum vasculosum of the lamina terminalis, and both structures are the main areas where synthesis of gonadotropin-releasing hormone occurs in the brain. Neurons synthesizing gonadotropin-releasing hormone migrate from the medial nasal epithelium to the rostral brain and reach the organum vasculosum of the lamina terminalis and the medial preoptic area. Kallmann syndrome is a genetic disorder which combines hypogonadotropic hypogonadism and anosmia. Hypogonadism is characterized by the absence or reduced levels of gonadotropin-releasing hormone and anosmia due to olfactory bulb aplasia. This paper speculates on the connection between the development of the medial preoptic area, the organum vasculosum of the lamina terminalis and olfactory bulbs with Kallmann syndrome, since the anteroventral third ventricle region is crucial for the normal development of these structures and its connection with the olfactory nerves and sexual maturation. PMID:23702295

Castañeyra-Perdomo, Agustín; Castañeyra-Ruiz, Leandro; González-Marrero, Ibrahim; Castañeyra-Ruiz, Agustín; González-Toledo, Juan M; de Paz-Carmona, Héctor; Castañeyra-Ruiz, María; Carmona-Calero, Emilia M

2013-08-01

180

Mesoscopic Strains Maps in Woven Composite Laminas During Off-axis Tension  

NASA Astrophysics Data System (ADS)

The mechanics of woven carbon-fiber reinforced plastic (CFRP) composites is influenced by the complex architecture of the reinforcement phase. Computational (i.e. finite element based) approaches have been used increasingly to model not only the global laminate stiffness, but also damage evolution and laminate strength. The modeling combines the identification of the architectural unit cell (UC), the selection of suitable constitutive models of the different phases, the creation of a fine discretization of the UC in finite elements, the application of an incremental solution procedure that solves iteratively for the stresses and strains in the UC, [1]. The experimental validation of computational models is carried out mainly at the macroscopical level, i.e. simulation of the macroscopic stress-strain curve. Damage, however, is a localized, straindependent phenomenon and therefore only accurate strain distribution within the UC (at the mesolevel) can identify critical conditions in terms of damage location, extension and evolution. The validation of computational damage procedures is a key task and full-field optical strain analysis methods appear the ideal instrument. However, only limited examples of direct finte element method (FEM) vs experimental strain correlation are found because of the limited sensitivity and spatial resolution of some techniques and the complexity and applicative difficulty of others. The aim of the present paper is to present the application of the digital image correlation (DIC) technique, [2], to the full-field strain analysis at the mesoscopic level (i.e. within the UC) of a woven CFRP lamina when the direction of loading forms an angle to the material direction. The material under consideration is a woven carbon fiber reinforced epoxy composite. Orthogonal yarns, each made of of several thousand fibers, are woven according the twill-weave architecture is shown in Fig. 1a. Single-ply laminas were manufactured and tested to eliminate the random 3D influence of multiple-ply laminates and to favor computational model validation. Specimens with different loading directions with respect to the material principal directions were prepared and tested in a servo-hydraulic testing machine. Specimen surface preparation consisted in a speckle pattern generation to allow the application of the DIC tecnique. During the tensile experiment, the speckle pattern is recorded (frame rate of 0.1 picture/second) using a CCD camera equipped with a microscopic lens and adjustable light sources. In-house DIC software was used for in-plane displacement and strain determination and mapping. For brevity only the case of loading in the tow yarn direction is considered here. Fig. 1b shows a tipical strain map obtained with the DIC technique at an applied macroscopic strain of 0.9%. The strains are small but the DIC dechnique is sensitive enough and suitable filtering reduce the noise level of the strain maps. Strong local strain gradients are determined and referred to the yarn architecture in Fig. 1c. The DIC measurements were validated by averaging the strain over the field of view and comparing it with the macroscopic strain given by a high-sensitivity MTS extensometer. The mesoscopic srain data obtained with DIC are used to assess and validate parallel material model development by direct FEM vs experimental strain correlation. Fig. 2a shows the FEM model of the unit cell for the twill-weave architecture with a detail of the yarn geometry and finite element discretization. Suitable boundary conditions are applied to the UC model contours before the analysis, [1]. Fig. 2b shows and example of the comparison of the local longitudinal FEM/DIC strain distribution along a transverse line of Fig. 1c. The comparison shows the excellent correlation achieved both in terms of gradients and absolute strain values, [3].

Anzelotti, G.; Nicoletto, G.; Riva, E.

2010-06-01

181

Ionic permeabilities of the gill lamina cuticle of the crayfish, Astacus leptodactylus (E).  

PubMed

The cuticle of the gill lamina of the crayfish Astacus leptodactylus (E), mechanically isolated, was mounted in an Ussing chamber and examined for its electrical properties. The cuticle of the gill lamina obtained from exuviae had similar properties. When perfused with artificial fresh water (AFW) outside and Van Harreveld solution (VH) inside, the transcuticular potential Voi was negative with respect to the inside, and close to the equilibrium potential for Cl- (ECl-). CH3COO-, HCO3-, SO4(2-) and cations (Na+, K+, Ca2+, Mg2+ and NH4+) behaved as impermeant ions with respect to Cl-. A decrease of pH (brought about with CO2) from 8.5 to 6.0 in AFW, VH or both had no effect on the potential. The cuticle area specific conductance was 20-30 mS/cm2 when superfused with AFW outside and VH inside. The conductance decreased linearly with log [Cl-] when Cl- was replaced by CH3COO-. Rectification was obvious when internal Cl- was reduced to 5 mmol/l. The Cl- selectivity of the cuticle could also be demonstrated in perfusing the cuticle with a single salt (NaCl, KCl, CaCl2, MgCl2 or LaCl3) and in diluting that salt on one side of the preparation or in replacing Cl- by CH3COO-, SO4(2-) and HCO3-. The potential changed almost linearly with log [Cl-] and was close to ECl-. The inner face of the cuticle was found to be slightly less selective than the outer face. The relative permeabilities were calculated to be: PCl- = 1, PNa+ = 0.001, PHCO3- = 0.0006, PCH3COO- = 0.0002. The dilution of a Cl- -free salt resulted in a cationic potential. The relative permeabilities of cations (NH4+, K+, Na+, Ca2+ and Mg2+) were found to range within a factor 2. The permeability of the cuticle to HCO3-, CH3COO- and SO4(2-) was 2-5 times lower. The cuticle conductance was linearly related to the activity of the salt perfusing the two sides of the preparation at equal concentrations. The molar area specific conductance to chloride salts was 14 (mS/cm2)/(mmol/l). That of Cl- -free salts ranged from 1 to 20 (microS/cm2)/(mmol/l) depending on the salt used. It was deduced that PCl- is 2 X 10(-3) cm/s and that all the other ions tested have permeabilities of 10(-7)-10(-6) cm/s. With large intensity current pulses the cuticle exhibited rectifying properties and an asymmetrical behaviour. Increasing the pH of the perfusing solution reduced the transcuticular potential established with a Cl- gradient.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2410607

Avenet, P; Lignon, J M

1985-06-01

182

Annual laminae as measured using fluorescence in historic stalagmites from Baradla Cave, Aggtelek National Park, Hungary.  

NASA Astrophysics Data System (ADS)

Calcite and aragonite speleothems (stalactites and stalagmites) deposited in caves often display fluorescence. It may take the form of couplets of greater and lesser intensity that have been shown to be annual pairs in some carefully controlled instances such as deposits in 20th Century canal tunnels. The variations of intensity are related to seasonal variations in concentrations of fluorophores (chiefly fulvic acids) in the feed water to the speleothem. To test for the possibility and replicability of couplet formation two small stalagmites likely to be of historic age were collected in Baradla Cave, Aggtelek National Park, Hungary, in 1992. This is a large cave in Triassic limestones and dolomites that have been intensely deformed by Carpathian tectonism to allow ready ground water penetration. As a consequence, it is profusely decorated with speleothems and has been a tourist attraction since the 18th Century. The samples were taken ten metres apart in an abandoned river passage at a depth of 40-60 m beneath the surface, which is mantled with terra rossas, rendzinas and luvisols mostly less than 50 cm in thickness. The vegetation cover is deciduous forest with small patches of grassland, spruce and pine. At a nearby meteorological station 30-year mean January and July temperatures are -3.5o C and 18.5o C respectively. Annual mean precipitation is 560 mm, with a summer maximum and actual evapotranspiration less than 400 mm. Samples AGG-1 and -2 were bright white calcite stalagmites 90 and 70 mm in length respectively and 40-50 mm in width. They were growing on the blackened stumps of larger stalagmites that had been taken as souvenirs. Blackening was caused by smoky torches used in the earliest days of tourism, and replaced by lanterns around 1820 CE. 2 mm thick slices were cut perpendicular to the growth axes of the samples, polished, excited by electronic flash gun and photographed at 1/60th second with Kodak TMAX ISO 3200 film, using multiple exposures to capture delayed fluorescence. Experiments determined that there was negligible phosphorescence, that results were reproducible and were not affected by the grain of the film. Images were imported into IP-LAB Spectrum for data retrieval. They displayed strong couplet development with repeated layers of high-low fluorescence. Assuming that each couplet represents one climatic year, Sample AGG-1 was 165 years in age when collected; i.e. it commenced growing in 1827 CE. The true base of Sample AGG-2 was destroyed in extraction; it yielded an age of 156 years. Both are in excellent agreement with the expected ages. Correlation of fluorescence intensity and derived laminae thickness between the two samples is also excellent when fitted with a three-year running mean to avoid misallocation of individual years. Interannual fluorescence intensity grew slightly between ~1830 and 1900 CE, then was stable until minor decline commenced after 1970. Annual calcite lamina generally range between 0.5 and 1.0 mm in thickness in AGG-1 after 1900 CE, slightly less before that time. Thicknesses in AGG-2 follow the same trend but are consistently 0.1 -0.2 mm thinner. There is little correlation with the matching mean temperature and precipitation records from a nearby meteorological station that began operating in 1962. Relationships with much lengthier meteorological records from Miskolc and Budapest are being investigated.

van Beynen, P.; Ford, D.; Schwarcz, H.

2012-04-01

183

Prelamin A and lamin A appear to be dispensable in the nuclear lamina.  

PubMed

Lamin A and lamin C, both products of Lmna, are key components of the nuclear lamina. In the mouse, a deficiency in both lamin A and lamin C leads to slow growth, muscle weakness, and death by 6 weeks of age. Fibroblasts deficient in lamins A and C contain misshapen and structurally weakened nuclei, and emerin is mislocalized away from the nuclear envelope. The physiologic rationale for the existence of the 2 different Lmna products lamin A and lamin C is unclear, although several reports have suggested that lamin A may have particularly important functions, for example in the targeting of emerin and lamin C to the nuclear envelope. Here we report the development of lamin C-only mice (Lmna(LCO/LCO)), which produce lamin C but no lamin A or prelamin A (the precursor to lamin A). Lmna(LCO/LCO) mice were entirely healthy, and Lmna(LCO/LCO) cells displayed normal emerin targeting and exhibited only very minimal alterations in nuclear shape and nuclear deformability. Thus, at least in the mouse, prelamin A and lamin A appear to be dispensable. Nevertheless, an accumulation of farnesyl-prelamin A (as occurs with a deficiency in the prelamin A processing enzyme Zmpste24) caused dramatically misshapen nuclei and progeria-like disease phenotypes. The apparent dispensability of prelamin A suggested that lamin A-related progeroid syndromes might be treated with impunity by reducing prelamin A synthesis. Remarkably, the presence of a single Lmna(LCO) allele eliminated the nuclear shape abnormalities and progeria-like disease phenotypes in Zmpste24-/- mice. Moreover, treating Zmpste24-/- cells with a prelamin A-specific antisense oligonucleotide reduced prelamin A levels and significantly reduced the frequency of misshapen nuclei. These studies suggest a new therapeutic strategy for treating progeria and other lamin A diseases. PMID:16511604

Fong, Loren G; Ng, Jennifer K; Lammerding, Jan; Vickers, Timothy A; Meta, Margarita; Coté, Nathan; Gavino, Bryant; Qiao, Xin; Chang, Sandy Y; Young, Stephanie R; Yang, Shao H; Stewart, Colin L; Lee, Richard T; Bennett, C Frank; Bergo, Martin O; Young, Stephen G

2006-03-01

184

Tooth replacement without a dental lamina: The search for epithelial stem cells in Polypterus senegalus.  

PubMed

Most actinopterygians replace their teeth continuously throughout life. To address the question of where and how replacement teeth form in actinopterygians, it is advisable to investigate well-chosen representatives within the lineage. The African bichir, Polypterus senegalus, belongs to the earliest diverged group of the actinopterygian lineage with currently living representatives. Its well characterized dentition, together with its phylogenetic position, make this species an attractive model to answer following questions: (1) when and where does the replacement tooth form and how is it connected with the dental organ of the predecessor, and (2) is there any evidence for the presence of epithelial stem cells, hypothesized to play a role in replacement? Serial sections show that one tooth family can contain up to three members, which are all interconnected by dental epithelium. Replacement teeth develop without the presence of a successional dental lamina. We propose that this is the plesiomorphic condition for tooth replacement in actinopterygians. BrdU pulse-chase experiments reveal cells in the outer and middle dental epithelium, proliferating at the time of initiation of a new replacement tooth. It is tempting to assume that these cell layers provide a stem cell niche. The observed absence of label-retaining cells after long chase times (up to 8 weeks) is held against the light of divergent views on cell cycling properties of stem cells. At present, our data do not support, neither reject, the hypothesis on involvement of epithelial stem cells within the process of continuous tooth replacement. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 281-293, 2014. © 2014 Wiley Periodicals, Inc. PMID:24890316

Vandenplas, Sam; De Clercq, Adelbert; Huysseune, Ann

2014-07-01

185

Lamina-Specific Anatomic Magnetic Resonance Imaging of the Human Retina  

PubMed Central

Purpose. Magnetic resonance imaging (MRI) of the human retina faces two major challenges: eye movement and hardware limitation that could preclude human retinal MRI with adequate spatiotemporal resolution. This study investigated eye-fixation stability and high-resolution anatomic MRI of the human retina on a 3-Tesla (T) MRI scanner. Comparison was made with optical coherence tomography (OCT) on the same subjects. Methods. Eye-fixation stability of protocols used in MRI was evaluated on four normal volunteers using an eye tracker. High-resolution MRI (100 × 200 × 2000 ?m) protocol was developed on a 3-T scanner. Subjects were instructed to maintain stable eye fixation on a target with cued blinks every 8 seconds during MRI. OCT imaging of the retina was performed. Retinal layer thicknesses measured with MRI and OCT were analyzed for matching regions of the same eyes close to the optic nerve head. Results. The temporal SDs of the horizontal and vertical displacements were 78 ± 51 and 130 ± 51 ?m (±SD, n = 4), respectively. MRI detected three layers within the human retina, consistent with MRI findings in rodent, feline, and baboon retinas. The hyperintense layer 1 closest to the vitreous likely consisted of nerve fiber, ganglion cell, and inner nuclear layer; the hypointense layer 2, the outer nuclear layer and the inner and outer segments; and the hyperintense layer 3, the choroid. The MRI retina/choroid thickness was 711 ± 37 ?m, 19% (P < 0.05) thicker than OCT thickness (579 ± 34 ?m). Conclusions. This study reports high-resolution MRI of lamina-specific structures in the human retina. These initial results are encouraging. Further improvement in spatiotemporal resolution is warranted.

Zhang, Yi; Nateras, Oscar San Emeterio; Peng, Qi; Kuranov, Roman V.; Harrison, Joseph M.; Milner, Thomas E.

2011-01-01

186

Inhibitor studies of leaf lamina hydraulic conductance in trembling aspen (Populus tremuloides Michx.) leaves.  

PubMed

The present study investigated leaf water transport properties in trembling aspen (Populus tremuloides) leaves. Leaf lamina hydraulic conductance (K(lam)) and stomatal conductance (g(s)) were drastically suppressed by NaF (a general metabolic inhibitor). In leaves treated with 0.2 mM HgCl(2) (an aquaporin blocker), K(lam) declined by 22% when the leaves were sampled in June but the decline was not significant when the leaves were sampled in August. The leaves sampled in June that transpired 30 mM beta-mercaptoethanol following mercury application showed similar K(lam) as those in control leaves transpiring distilled water. When leaves were pressure-infiltrated with 0.1 mM HgCl(2), K(lam) significantly declined by 25%. Atrazine (a photosystem II inhibitor) drastically reduced leaf net CO(2) uptake by the leaves from seedlings and mature trees but did not have any effect on K(lam) regardless of the irradiance at the leaf level during the K(lam) measurements. When PTS(3) (trisodium 3-hydroxy-5,8,10-pyrenetrisulphonate) apoplastic tracer was pressure-infiltrated inside the leaves, its concentration in the leaf exudates did not change from ambient light to high irradiance treatment and declined in the presence of HgCl(2) in the treatment solution. Trembling aspen K(lam) appears to be linked to leaf metabolism and is uncoupled from the short-term variations in photosynthesis. Aquaporin-mediated water transport does not appear to constitute the dominant pathway for the pressure-driven water flow in the leaves of trembling aspen trees. PMID:20022867

Voicu, Mihaela C; Zwiazek, Janusz J

2010-02-01

187

Prelamin A and lamin A appear to be dispensable in the nuclear lamina  

PubMed Central

Lamin A and lamin C, both products of Lmna, are key components of the nuclear lamina. In the mouse, a deficiency in both lamin A and lamin C leads to slow growth, muscle weakness, and death by 6 weeks of age. Fibroblasts deficient in lamins A and C contain misshapen and structurally weakened nuclei, and emerin is mislocalized away from the nuclear envelope. The physiologic rationale for the existence of the 2 different Lmna products lamin A and lamin C is unclear, although several reports have suggested that lamin A may have particularly important functions, for example in the targeting of emerin and lamin C to the nuclear envelope. Here we report the development of lamin C–only mice (Lmna+/+), which produce lamin C but no lamin A or prelamin A (the precursor to lamin A). Lmna+/+ mice were entirely healthy, and Lmna+/+ cells displayed normal emerin targeting and exhibited only very minimal alterations in nuclear shape and nuclear deformability. Thus, at least in the mouse, prelamin A and lamin A appear to be dispensable. Nevertheless, an accumulation of farnesyl–prelamin A (as occurs with a deficiency in the prelamin A processing enzyme Zmpste24) caused dramatically misshapen nuclei and progeria-like disease phenotypes. The apparent dispensability of prelamin A suggested that lamin A–related progeroid syndromes might be treated with impunity by reducing prelamin A synthesis. Remarkably, the presence of a single LmnaLCO allele eliminated the nuclear shape abnormalities and progeria-like disease phenotypes in Zmpste24–/– mice. Moreover, treating Zmpste24–/– cells with a prelamin A–specific antisense oligonucleotide reduced prelamin A levels and significantly reduced the frequency of misshapen nuclei. These studies suggest a new therapeutic strategy for treating progeria and other lamin A diseases.

Fong, Loren G.; Ng, Jennifer K.; Lammerding, Jan; Vickers, Timothy A.; Meta, Margarita; Cote, Nathan; Gavino, Bryant; Qiao, Xin; Chang, Sandy Y.; Young, Stephanie R.; Yang, Shao H.; Stewart, Colin L.; Lee, Richard T.; Bennett, C. Frank; Bergo, Martin O.; Young, Stephen G.

2006-01-01

188

Transventricular fenestration of the lamina terminalis: the value of a flexible endoscope: technical note.  

PubMed

Background?Recently, the authors demonstrated the technical feasibility of a transventricular translaminar terminalis ventriculostomy with a rigid endoscope. A major problem with this technique remains the contusion of the fornix at the foramen of Monro. Here, the authors evaluated alternative approaches and techniques, including the use of a flexible endoscope. Material and Methods?Feasibility of two approaches-anterior and posterior of the coronal suture-was evaluated on magnetic resonance images and in cadaveric brains. Two different trajectories were selected. Lamina terminalis (LT) fenestration was performed with a rigid and a flexible endoscope using two approaches in 10 fixed cadaver brains. Results?Using the posterior approach 2 cm behind the coronal suture with the two endoscopes caused moderate to severe damage to foramen and fornix. Using the standard approach (Kocher point) with the flexible endoscope avoided damage of these structures. After completion of the anatomical investigation, the authors successfully performed a transventricular fenestration of the LT with the flexible endoscope in one clinical case. Conclusion?Rigid scopes provide brilliant optics and safe manipulation with the instruments. However, with the rigid scope, a transventricular opening of the LT is only possible with acceptance of structural damage to the foramen of Monro and the fornix. In contrast, opening of the LT via a transventricular route with preservation of the anatomical structures can be achieved with a flexible steerable endoscope even via a standard burr hole. Thus, if a standard third ventriculostomy is not feasible, endoscopic opening of the LT might represent an alternative, particularly with a flexible scope in experienced hands. PMID:23939681

Vulcu, Sonja; Tschabitscher, Manfred; Mueller-Forell, Wibke; Oertel, Joachim

2014-05-01

189

Remodeling of the Connective Tissue Microarchitecture of the Lamina Cribrosa in Early Experimental Glaucoma  

PubMed Central

Purpose To characterize the trabeculated connective tissue microarchitecture of the lamina cribrosa (LC) in terms of total connective tissue volume (CTV), connective tissue volume fraction (CTVF), predominant beam orientation, and material anisotropy in monkeys with early experimental glaucoma (EG). Methods The optic nerve heads from three monkeys with unilateral EG and four bilaterally normal monkeys were three dimensionally reconstructed from tissues perfusion fixed at an intraocular pressure of 10 mm Hg. A three-dimensional segmentation algorithm was used to extract a binary, voxel-based representation of the porous LC connective tissue microstructure that was regionalized into 45 subvolumes, and the following quantities were calculated: total CTV within the LC, mean and regional CTVF, regional predominant beam orientation, and mean and regional material anisotropy. Results Regional variation within the laminar microstructure was considerable within the normal eyes of all monkeys. The laminar connective tissue was generally most dense in the central and superior regions for the paired normal eyes, and laminar beams were radially oriented at the periphery for all eyes considered. CTV increased substantially in EG eyes compared with contralateral normal eyes (82%, 44%, 45% increases; P < 0.05), but average CTVF changed little (?7%, 1%, and ?2% in the EG eyes). There were more laminar beams through the thickness of the LC in the EG eyes than in the normal controls (46%, 18%, 17% increases). Conclusions The substantial increase in laminar CTV with little change in CTVF suggests that significant alterations in connective and nonconnective tissue components in the laminar region occur in the early stages of glaucomatous damage.

Roberts, Michael D.; Grau, Vicente; Grimm, Jonathan; Reynaud, Juan; Bellezza, Anthony J.; Burgoyne, Claude F.; Downs, J. Crawford

2009-01-01

190

NOVA: Deep Sea Invasion  

NSDL National Science Digital Library

This is the companion Web site to "Deep Sea Invasion," a PBS NOVA documentary broadcast April 1, 2003. The program follows marine biologist Alexandre Meinesz and his scientific detective work to explain the rampant spread of the tropical alga Caulerpa taxifolia through the Mediterranean and his struggle to instigate control efforts. The features of this Web site include a timeline chronicling the invasion, an article by Meinesz on the impact of invasive species, another article addressing strategies for controlling invasives, and an interactive quiz in which users match up species with their invasive characteristics. With interesting material covering a range of ecological topics, this Web site should be of interest to any reader.

2003-01-01

191

Minimally invasive lumbar decompression for the treatment of spinal stenosis of the lumbar spine.  

PubMed

SUMMARY Lumbar spinal stenosis is one of the most common degenerative diseases of the elderly population, and a major cause of debilitating pain and decreased function. Lumbar spinal stenosis is almost always associated with neurogenic claudication characterized as pain worsened by standing or walking and relieved by lumbar flexion or sitting. While initial treatment of lumbar spinal stenosis may involve conservative therapies, as patients become more symptomatic the traditional treatment path has generally led to open laminectomy and other invasive, potentially destabilizing, procedures. More recently, less invasive alternatives to wide laminectomy have been developed. This article describes a new method of percutaneous lumbar decompression for treatment of neurogenic claudication secondary to lumbar spinal stenosis, the minimally invasive lumbar decompression procedure. We review the steps of successfully decompressing the hypertrophic ligamentum flavum and lamina, thereby alleviating pressure on neural structures. This is a major innovation in patient care and a step to reduce risks while minimizing costs. PMID:24645862

Deer, Timothy

2012-09-01

192

Collateral projections of neurons in laminae I, III, and IV of rat spinal cord to thalamus, periaqueductal gray matter, and lateral parabrachial area  

PubMed Central

Projection neurons in lamina I, together with those in laminae III–IV that express the neurokinin 1 receptor (NK1r), form a major route through which nociceptive information reaches the brain. Axons of these cells innervate various targets, including thalamus, periaqueductal gray matter (PAG), and lateral parabrachial area (LPb), and many cells project to more than one target. The aims of this study were to quantify projections from cervical enlargement to PAG and LPb, to determine the proportion of spinothalamic neurons at lumbar and cervical levels that were labelled from PAG and LPb, and to investigate morphological differences between projection populations. The C7 segment contained fewer lamina I spinoparabrachial cells than L4, but a similar number of spino-PAG cells. Virtually all spinothalamic lamina I neurons at both levels were labelled from LPb and between one-third and one-half from PAG. This suggests that significant numbers project to all three targets. Spinothalamic lamina I neurons differed from those labelled only from LPb in that they were generally larger, were more often multipolar, and (in cervical enlargement) had stronger NK1r immunoreactivity. Most lamina III/IV NK1r cells at both levels projected to LPb, but few were labelled from PAG. The great majority of these cells in C7 and over one-fourth of those in L4 were spinothalamic, and at each level some projected to both thalamus and LPb. These results confirm that neurons in these laminae have extensive collateral projections and suggest that different neuronal subpopulations in lamina I have characteristic patterns of supraspinal projection. J. Comp. Neurol. 515:629–646, 2009.

Al-Khater, Khulood M; Todd, Andrew J

2009-01-01

193

Oxidative stress, mitochondrial dysfunction and calcium overload in human lamina cribrosa cells from glaucoma donors  

PubMed Central

Purpose Oxidative stress is implicit in the pathological changes associated with glaucoma. The purpose of this study was to compare levels of oxidative stress in glial fibrillary acid-negative protein (GFAP) lamina cribrosa (LC) cells obtained from the optic nerve head (ONH) region of 5 normal (NLC) and 4 glaucomatous (GLC) human donor eyes and to also examine mitochondrial function and calcium homeostasis in this region of the ONH. Methods Intracellular reactive oxygen species (ROS) production was examined by a thiobarbituric acid reactive substances (TBARS) assay which measures malondialdehyde (MDA), a naturally occurring product of lipid peroxidation and is used as an indicator of oxidative stress. Mitochondrial membrane potential (MMP) and intracellular calcium ([Ca2+]i) levels were evaluated by flow cytometry using the JC-1 (5,5?,6,6?-tetrachloro-1,1?,3,3?-tetrabenzimidazolecarbocyanine iodide) and fluo-4/AM probes respectively. Anti-oxidant and Ca2+ transport system gene and protein expression were determined by real time polymerase chain reaction (RT-PCR) using gene-specific primer/probe sets and western immunoblotting, respectively. Results Intracellular ROS production was increased in GLC compared to NLC (27.19±7.05 µM MDA versus 14.59±0.82 µM MDA, p<0.05). Expression of the anti-oxidants Aldo-keto reductase family 1 member C1 (AKR1C1) and Glutamate cysteine ligase catalytic subunit (GCLC) were significantly lower in GLC (p=0.02) compared to NLC control. MMP was lower in GLC (57.5±6.8%) compared to NLC (41.8±5.3%). [Ca2+]i levels were found to be higher (p<0.001) in GLC cells compared to NLC. Expression of the plasma membrane Ca2+/ATPase (PMCA) and the sodium-calcium (NCX) exchangers were lower, while intracellular sarco-endoplasmic reticulum Ca2+/ATPase 3 (SERCA) expression was significantly higher in GLC compared to NLC. Subjection of NLC cells to oxidative stress (200 µM H202) reduced expression of Na+/Ca2+ exchanger 1 (NCX 1), plasma membrane Ca2+ ATPase 1 (PMCA 1), and PMCA 4 as determined by RT–PCR. Conclusions Our data finds evidence of oxidative stress, mitochondrial dysfunction and impaired calcium extrusion in GLC cells compared to NLC cells and suggests their importance in the pathological changes occurring at the ONH in glaucoma. Future therapies may target reducing oxidative stress and / or [Ca2+]i.

McElnea, E.M.; Quill, B.; Docherty, N.G.; Irnaten, M.; Siah, W.F.; Clark, A.F.; O'Brien, C.J.

2011-01-01

194

Impact of laminitis on the canonical Wnt signaling pathway in basal epithelial cells of the equine digital laminae.  

PubMed

The digital laminae is a two layer tissue that attaches the distal phalanx to the inner hoof wall, thus suspending the horse's axial skeleton in the hoof capsule. This tissue fails at the epidermal:dermal junction in laminitic horses, causing crippling disease. Basal epithelial cells line the laminar epidermal:dermal junction, undergo physiological change in laminitic horses, and lose versican gene expression. Versican gene expression is purportedly under control of the canonical Wnt signaling pathway and is a trigger for mesenchymal-to-epithelial transition; thus, its repression in laminar epithelial cells of laminitic horses may be associated with suppression of the canonical Wnt signaling pathway and loss of the epithelial cell phenotype. In support of the former contention, we show, using laminae from healthy horses and horses with carbohydrate overload-induced laminitis, quantitative real-time polymerase chain reaction, Western blotting after sodium dodecylsulfate polyacrylamide gel electrophoresis, and immunofluorescent tissue staining, that positive and negative regulatory components of the canonical Wnt signaling pathway are expressed in laminar basal epithelial cells of healthy horses. Furthermore, expression of positive regulators is suppressed and negative regulators elevated in laminae of laminitic compared to healthy horses. We also show that versican gene expression in the epithelial cells correlates positively with that of ?-catenin and T-cell Factor 4, consistent with regulation by the canonical Wnt signaling pathway. In addition, gene and protein expression of ?-catenin correlates positively with that of integrin ?4 and both are strongly suppressed in laminar basal epithelial cells of laminitic horses, which remain E-cadherin(+)/vimentin(-), excluding mesenchymal transition as contributing to loss of the adherens junction and hemidesmosome components. We propose that suppression of the canonical Wnt signaling pathway, and accompanying reduced expression of ? catenin and integrin ?4 in laminar basal epithelial cells reduces cell:cell and cell:basement membrane attachment, thus, destabilizing the laminar epidermal:dermal junction. PMID:23405249

Wang, Le; Pawlak, Erica A; Johnson, Philip J; Belknap, James K; Eades, Susan; Stack, Sharon; Cousin, Helene; Black, Samuel J

2013-01-01

195

NR2 subunits and NMDA receptors on lamina II inhibitory and excitatory interneurons of the mouse dorsal horn  

PubMed Central

Background NMDA receptors expressed by spinal cord neurons in the superficial dorsal horn are involved in the development of chronic pain associated with inflammation and nerve injury. The superficial dorsal horn has a complex and still poorly understood circuitry that is mainly populated by inhibitory and excitatory interneurons. Little is known about how NMDA receptor subunit composition, and therefore pharmacology and voltage dependence, varies with neuronal cell type. NMDA receptors are typically composed of two NR1 subunits and two of four NR2 subunits, NR2A-2D. We took advantage of the differences in Mg2+ sensitivity of the NMDA receptor subtypes together with subtype preferring antagonists to identify the NR2 subunit composition of NMDA receptors expressed on lamina II inhibitory and excitatory interneurons. To distinguish between excitatory and inhibitory interneurons, we used transgenic mice expressing enhanced green fluorescent protein driven by the GAD67 promoter. Results Analysis of conductance ratio and selective antagonists showed that lamina II GABAergic interneurons express both the NR2A/B containing Mg2+ sensitive receptors and the NR2C/D containing NMDA receptors with less Mg2+ sensitivity. In contrast, excitatory lamina II interneurons express primarily NR2A/B containing receptors. Despite this clear difference in NMDA receptor subunit expression in the two neuronal populations, focally stimulated synaptic input is mediated exclusively by NR2A and 2B containing receptors in both neuronal populations. Conclusions Stronger expression of NMDA receptors with NR2C/D subunits by inhibitory interneurons compared to excitatory interneurons may provide a mechanism to selectively increase activity of inhibitory neurons during intense excitatory drive that can provide inhibitory feedback.

2010-01-01

196

Fine structure and synaptic architecture of HRP-labelled primary afferent terminations in lamina IIi of the rat dorsal horn.  

PubMed

The fine structure and synaptic architecture of the afferent terminations in dorsal horn lamina II are studied using a combined light and electron microscopic procedure after anterograde labelling with horseradish peroxidase. Vibratome parasagittal sections, stained with heavy metal intensified diaminobenzidine after tracer application to the dorsal roots, were flat-embedded in Epon. The five types of labelled terminal arbors occurring in lamina IIi (Cruz et al., '87: J. Comp. Neurol. 261:221-236) were drawn and relocated in 5-microns sections cut serially from the thick sections. Ultrathin sections were then cut from the 5-microns sections so that the terminal fibers and swellings observed in the light microscope could be traced in the electron microscope. The flame-shaped arbors arose from fine myelinated stem fibers. Terminal strands generated large oval central terminals of type II synaptic glomeruli (CII), which established frequent axoaxonal contacts. Similar terminals have been labelled in the cat after tracer injections into hair-follicle fibers (Réthelyi et al., '82: J. Comp. Neurol. 207:381-393). The other four plexuses arose from unmyelinated stem fibers. The swarms of ultrafine boutons consisted of extremely thin terminal fibers generating very small, round, or polygonal glomerular terminals containing tightly packed agranular synaptic vesicles of variable size and one mitochondrion at best. The terminal strands of the bouquet plexus bore long and scalloped central varicosities of type I synaptic glomeruli (CI) with pleomorphic agranular vesicles and a relative abundance of dendroaxonal contacts. These features, together with the location in dorsal lamina IIi, suggest their belonging to the fluoride resistant acid phosphatase (FRAP)-reactive population. The boutons of the undulating fibers and those of the lateral plexus were, like those of the bouquets, scalloped and elongated rostrocaudally (CI), but contained a few large granular vesicles. The occurrence of the swarm, undulating, and lateral plexuses in ventral lamina IIi, which seems to lack FRAP or peptidergic terminals, suggests an origin from other, still unidentified neurochemical populations of fine primary afferents. PMID:2033122

Cruz, F; Lima, D; Zieglgänsberger, W; Coimbra, A

1991-03-01

197

Nucleating actin for invasion  

Microsoft Academic Search

The invasion of cancer cells into the surrounding tissue is a prerequisite and initial step in metastasis, which is the leading cause of death from cancer. Invasive cell migration requires the formation of various structures, such as invadopodia and pseudopodia, which require actin assembly that is regulated by specialized actin nucleation factors. There is a large variety of different actin

Alexander Nürnberg; Thomas Kitzing; Robert Grosse

2011-01-01

198

Nuclear lamina defects cause ATM-dependent NF-?B activation and link accelerated aging to a systemic inflammatory response  

PubMed Central

Alterations in the architecture and dynamics of the nuclear lamina have a causal role in normal and accelerated aging through both cell-autonomous and systemic mechanisms. However, the precise nature of the molecular cues involved in this process remains incompletely defined. Here we report that the accumulation of prelamin A isoforms at the nuclear lamina triggers an ATM- and NEMO-dependent signaling pathway that leads to NF-?B activation and secretion of high levels of proinflammatory cytokines in two different mouse models of accelerated aging (Zmpste24?/? and LmnaG609G/G609G mice). Causal involvement of NF-?B in accelerated aging was demonstrated by the fact that both genetic and pharmacological inhibition of NF-?B signaling prevents age-associated features in these animal models, significantly extending their longevity. Our findings provide in vivo proof of principle for the feasibility of pharmacological modulation of the NF-?B pathway to slow down the progression of physiological and pathological aging.

Osorio, Fernando G.; Barcena, Clea; Soria-Valles, Clara; Ramsay, Andrew J.; de Carlos, Felix; Cobo, Juan; Fueyo, Antonio; Freije, Jose M.P.; Lopez-Otin, Carlos

2012-01-01

199

Constitutive lymphocyte transmigration across the basal lamina of high endothelial venules is regulated by the autotaxin/lysophosphatidic acid axis.  

PubMed

Lymphocyte extravasation from the high endothelial venules (HEVs) of lymph nodes is crucial for the maintenance of immune homeostasis, but its molecular mechanism remains largely unknown. In this article, we report that lymphocyte transmigration across the basal lamina of the HEVs is regulated, at least in part, by autotaxin (ATX) and its end-product, lysophosphatidic acid (LPA). ATX is an HEV-associated ectoenzyme that produces LPA from lysophosphatidylcholine (LPC), which is abundant in the systemic circulation. In agreement with selective expression of ATX in HEVs, LPA was constitutively and specifically detected on HEVs. In vivo, inhibition of ATX impaired the lymphocyte extravasation from HEVs, inducing lymphocyte accumulation within the endothelial cells (ECs) and sub-EC compartment; this impairment was abrogated by LPA. In vitro, both LPA and LPC induced a marked increase in the motility of HEV ECs; LPC's effect was abrogated by ATX inhibition, whereas LPA's effect was abrogated by ATX/LPA receptor inhibition. In an in vitro transmigration assay, ATX inhibition impaired the release of lymphocytes that had migrated underneath HEV ECs, and these defects were abrogated by LPA. This effect of LPA was dependent on myosin II activity in the HEV ECs. Collectively, these results strongly suggest that HEV-associated ATX generates LPA locally; LPA, in turn, acts on HEV ECs to increase their motility, promoting dynamic lymphocyte-HEV interactions and subsequent lymphocyte transmigration across the basal lamina of HEVs at steady state. PMID:23365076

Bai, Zhongbin; Cai, Linjun; Umemoto, Eiji; Takeda, Akira; Tohya, Kazuo; Komai, Yutaka; Veeraveedu, Punniyakoti Thanikachalam; Hata, Erina; Sugiura, Yuki; Kubo, Akiko; Suematsu, Makoto; Hayasaka, Haruko; Okudaira, Shinichi; Aoki, Junken; Tanaka, Toshiyuki; Albers, Harald M H G; Ovaa, Huib; Miyasaka, Masayuki

2013-03-01

200

Environmental enrichment causes a global potentiation of neuronal responses across stimulus complexity and lamina of sensory cortex  

PubMed Central

Enriched social and physical housing produces many molecular, anatomical, electrophysiological and behavior benefits even in adult animals. Much less is known of its effects on cortical electrophysiology, especially in how sensory cortex encodes the altered environment, and extant studies have generally been restricted to neurons in input laminae in sensory cortex. To extend the understanding of how an enriched environment alters the way in which cortex views the world, we investigated enrichment-induced changes in neuronal encoding of sensory stimuli across all laminae of the rat barrel cortex receiving input from the face whisker tactile system. Animals were housed in Enriched (n = 13) or Isolated housing (n = 13) conditions for 8 weeks before extracellular recordings were obtained from barrel cortex in response to simple whisker deflections and whisker motions modeling movements seen in awake animals undertaking a variety of different tasks. Enrichment resulted in increases in neuronal responses to all stimuli, ranging from those modeling exploratory behavior through to discrimination behaviors. These increases were seen throughout the cortex from supragranular layers through to input Layer 4 and for some stimuli, in infragranular Layer 5. The observed enrichment-induced effect is consistent with the postulate that enrichment causes shift in cortical excitatory/inhibitory balance, and we demonstrate this is greatest in supragranular layers. However, we also report that the effects are non-selective for stimulus parameters across a range of stimuli except for one modeling the likely use of whiskers by the rats in the enriched housing.

Alwis, Dasuni S.; Rajan, Ramesh

2013-01-01

201

Incorporation of the nuclear pore basket protein Nup153 into nuclear pore structures is dependent upon lamina assembly: evidence from cell-free extracts of Xenopus eggs  

PubMed Central

In cell-free extracts of Xenopus eggs that support the assembly of replication-competent nuclei, we found that lamin B3 specifically associates with four polypeptides (termed SLAPs, soluble lamin associated proteins). Here, one SLAP is identified as the nuclear pore complex protein Nup153, one member of the F/GXFG motif-containing nucleoporins. In vitro translated Nup153 and lamin B3 co-immunoprecipitate, and lamin B3 interacts specifically with the C-terminal domain of Nup153. During nuclear envelope assembly, other F/GXFG-containing nucleoporins are incorporated into the nuclear envelope preceding lamina assembly. Incorporation of Nup153 occurs at the same time as lamina assembly. When lamina assembly is prevented using the dominant-negative mutant XlaminB?2+, Nup153 does not appear at the nuclear envelope, while other F/GXFG-containing nucleoporins and Nup93 are recruited normally. When the lamina of pre-assembled nuclei is disrupted using the same dominant-negative mutant, the distribution of other nucleoporins is unaffected. However, Nup153 recruitment at the nuclear envelope is lost. Our results indicate that both the recruitment and maintenance of Nup153 at the pore are dependent upon the integrity of the lamina.

Smythe, Carl; Jenkins, Hazel E.; Hutchison, Christopher J.

2000-01-01

202

"Cortactin and tumor invasiveness"  

PubMed Central

Cortactin is a cytoskeletal protein and src kinase substrate that is frequently overexpressed in cancer. Animal studies suggest that cortactin overexpression increases tumor aggressiveness, possibly through promotion of tumor invasion and metastasis. Recently, many studies have documented a role for cortactin in promoting cell motility and invasion, including a critical role in invadopodia, actin rich-subcellular protrusions associated with degradation of the extracellular matrix by cancer cells. Here, I review the evidence and potential mechanisms for cortactin as a critical mediator of tumor cell invasion.

Weaver, Alissa M.

2008-01-01

203

Invasive Prenatal Testing  

PubMed Central

Invasive prenatal diagnosis is a major diagnostic tool which is used in modern obstetrical care. A synopsis of these techniques is provided to assist the family practitioner in providing this information to his patients.

Hunter, A.

1988-01-01

204

Invasive Ductal Carcinoma  

MedlinePLUS

... are possible. If your breast cannot be conserved, breast reconstruction surgery may be a possibility after you recover from your initial operation to remove the cancer. Most women with invasive breast cancer will be offered chemotherapy and/or hormonal ...

205

Invasive Lobular Carcinoma  

MedlinePLUS

... are possible. If your breast cannot be conserved, breast reconstruction surgery may be a possibility after you recover from your initial operation to remove the cancer. Most women with invasive breast cancer will be offered chemotherapy and/or hormonal ...

206

Invasion Ecology (Student Edition)  

NSDL National Science Digital Library

Strange intruders are invading our part of the world, threatening our environment and our economy. These newcomers and their impact on our ecological balance are the focus of Invasion Ecology, a guide to learning skills for investigating the behaviors on non-native and native species. Studying invaders such as zebra mussels, chestnut blight, purple loosestrife, and Phragmites, you will explore how scientists are fighting these aggressors with biological controls. This Student Edition has three sections: (1) Background on the science of ecology and its place in the control of invasive species (2) Protocols for practicing methods that scientists use in monitoring invasive species, such as early detection surveys, plot sampling, transect surveys, and decomposition studies (3) A series of helpful worksheets to guide you through your own interactive research Invasion Ecology is the second volume in the four-part Environmental Inquiry curriculum series, designed to show you how to apply scientific knowledge to solving real-life problems.

Krasny, Marianne E.; Team, The E.

2003-01-01

207

Microbial ecology of biological invasions  

Microsoft Academic Search

Invasive microbes, plants and animals are a major threat to the composition and functioning of ecosystems; however, the mechanistic basis of why exotic species can be so abundant and disruptive is not well understood. Most studies have focused on invasive plants and animals, although few have considered the effects of invasive microbes, or interactions of invasive plant and animal species

Wim H van der Putten; John N Klironomos; David A Wardle; WH van der Putten

2007-01-01

208

Repeatability of in vivo 3D lamina cribrosa microarchitecture using adaptive optics spectral domain optical coherence tomography  

PubMed Central

We demonstrate the repeatability of lamina cribrosa (LC) microarchitecture for in vivo 3D optical coherence tomography (OCT) scans of healthy, glaucoma suspects, and glaucomatous eyes. Eyes underwent two scans using a prototype adaptive optics spectral domain OCT (AO-SDOCT) device from which LC microarchitecture was semi-automatically segmented. LC segmentations were used to quantify pore and beam structure through several global microarchitecture parameters. Repeatability of LC microarchitecture was assessed qualitatively and quantitatively by calculating parameter imprecision. For all but one parameters (pore volume) measurement imprecision was <4.7% of the mean value, indicating good measurement reproducibility. Imprecision ranged between 27.3% and 54.5% of the population standard deviation for each parameter, while there was not a significant effect on imprecision due to disease status, indicating utility in testing for LC structural trends.

Nadler, Zach; Wang, Bo; Wollstein, Gadi; Nevins, Jessica E.; Ishikawa, Hiroshi; Bilonick, Richard; Kagemann, Larry; Sigal, Ian A.; Ferguson, R. Daniel; Patel, Ankit; Hammer, Daniel X.; Schuman, Joel S.

2014-01-01

209

Repeatability of in vivo 3D lamina cribrosa microarchitecture using adaptive optics spectral domain optical coherence tomography.  

PubMed

We demonstrate the repeatability of lamina cribrosa (LC) microarchitecture for in vivo 3D optical coherence tomography (OCT) scans of healthy, glaucoma suspects, and glaucomatous eyes. Eyes underwent two scans using a prototype adaptive optics spectral domain OCT (AO-SDOCT) device from which LC microarchitecture was semi-automatically segmented. LC segmentations were used to quantify pore and beam structure through several global microarchitecture parameters. Repeatability of LC microarchitecture was assessed qualitatively and quantitatively by calculating parameter imprecision. For all but one parameters (pore volume) measurement imprecision was <4.7% of the mean value, indicating good measurement reproducibility. Imprecision ranged between 27.3% and 54.5% of the population standard deviation for each parameter, while there was not a significant effect on imprecision due to disease status, indicating utility in testing for LC structural trends. PMID:24761293

Nadler, Zach; Wang, Bo; Wollstein, Gadi; Nevins, Jessica E; Ishikawa, Hiroshi; Bilonick, Richard; Kagemann, Larry; Sigal, Ian A; Ferguson, R Daniel; Patel, Ankit; Hammer, Daniel X; Schuman, Joel S

2014-04-01

210

Inactivation of Retinoblastoma Protein Does Not Overcome the Requirement for Human Cytomegalovirus UL97 in Lamina Disruption and Nuclear Egress  

PubMed Central

Human cytomegalovirus (HCMV) encodes one conventional protein kinase, UL97. During infection, UL97 phosphorylates the retinoblastoma tumor suppressor protein (pRb) on sites ordinarily phosphorylated by cyclin-dependent kinases (CDK), inactivating the ability of pRb to repress host genes required for cell cycle progression to S phase. UL97 is important for viral DNA synthesis in quiescent cells, but this function can be replaced by human papillomavirus type 16 E7, which targets pRb for degradation. However, viruses in which E7 replaces UL97 are still defective for virus production. UL97 is also required for efficient nuclear egress of viral nucleocapsids, which is associated with disruption of the nuclear lamina during infection, and phosphorylation of lamin A/C on serine 22, which antagonizes lamin polymerization. We investigated whether inactivation of pRb might overcome the requirement of UL97 for these roles, as pRb inactivation induces CDK1, and CDK1 phosphorylates lamin A/C on serine 22. We found that lamin A/C serine 22 phosphorylation during HCMV infection correlated with expression of UL97 and was considerably delayed in UL97-null mutants, even when E7 was expressed. E7 failed to restore gaps in the nuclear lamina seen in wild-type but not UL97-null virus infections. In electron microscopy analyses, a UL97-null virus expressing E7 was as impaired as a UL97-null mutant in cytoplasmic accumulation of viral nucleocapsids. Our results demonstrate that pRb inactivation is insufficient to restore efficient viral nuclear egress of HCMV in the absence of UL97 and instead argue further for a direct role of UL97 in this stage of the infectious cycle.

Reim, Natalia I.; Wang, Depeng; Lin, Alison; Sharma, Mayuri; Ericsson, Maria; Pesola, Jean M.; Golan, David E.

2013-01-01

211

Blood-nerve barrier: distribution of anionic sites on the endothelial plasma membrane and basal lamina of dorsal root ganglia.  

PubMed

Previous investigations of the blood-nerve barrier have correlated the greater permeability of ganglionic endoneurial vessels, compared to those of nerve trunks, with the presence of fenestrations and open intercellular junctions. Recent studies have demonstrated reduced endothelial cell surface charge in blood vessels showing greater permeability. To determine the distribution of anionic sites on the plasma membranes and basal laminae of endothelial cells in dorsal root ganglia, cationic colloidal gold and cationic ferritin were used. Electron microscopy revealed the existence of endothelial microdomains with differing labelling densities. Labelling indicated that caveolar and fenestral diaphragms and basal laminae are highly anionic at physiological pH, luminal plasma membranes and endothelial processes are moderately charged and abluminal plasma membranes are weakly anionic. Tracers did not occur in caveolae or cytoplasmic vesicles. In vitro tracer experiments at pH values of 7.3, 5.0, 3.5 and 2.0 indicated that the anionic charge on the various endothelial domains was contributed by chemical groups with differing pKa values. In summary, the labelling of ganglionic and sciatic nerve vessels was similar except for the heavy labelling of diaphragms in a minority of endoneurial vessels in ganglia. This difference is likely to account in part for the greater permeability of ganglionic endoneurial vessels. The results are discussed with regard to the blood-nerve and -brain barriers and vascular permeability in other tissues and a comparison made between the ultrastructure and anionic microdomains of epi-, peri- and endoneurial vessels of dorsal root ganglia and sciatic nerves. PMID:1960538

Bush, M S; Reid, A R; Allt, G

1991-09-01

212

Heterogeneity of silica and glycan-epitope distribution in epidermal idioblast cell walls in Adiantum raddianum laminae.  

PubMed

Laminae of Adiantum raddianum Presl., a fern belonging to the family Pteridaceae, are characterised by the presence of epidermal fibre-like cells under the vascular bundles. These cells were thought to contain silica bodies, but their thickened walls leave no space for intracellular silica suggesting it may actually be deposited within their walls. Using advanced electron microscopy in conjunction with energy dispersive X-ray microanalysis we showed the presence of silica in the cell walls of the fibre-like idioblasts. However, it was specifically localised to the outer layers of the periclinal wall facing the leaf surface, with the thick secondary wall being devoid of silica. Immunocytochemical experiments were performed to ascertain the respective localisation of silica deposition and glycan polymers. Epitopes characteristic for pectic homogalacturonan and the hemicelluloses xyloglucan and mannan were detected in most epidermal walls, including the silica-rich cell wall layers. The monoclonal antibody, LM6, raised against pectic arabinan, labelled the silica-rich primary wall of the epidermal fibre-like cells and the guard cell walls, which were also shown to contain silica. We hypothesise that the silicified outer wall layers of the epidermal fibre-like cells support the lamina during cell expansion prior to secondary wall formation. This implies that silicification does not impede cell elongation. Although our results suggest that pectic arabinan may be implicated in silica deposition, further detailed analyses are needed to confirm this. The combinatorial approach presented here, which allows correlative screening and in situ localisation of silicon and cell wall polysaccharide distribution, shows great potential for future studies. PMID:23430352

Leroux, Olivier; Leroux, Frederic; Mastroberti, Alexandra Antunes; Santos-Silva, Fernanda; Van Loo, Denis; Bagniewska-Zadworna, Agnieszka; Van Hoorebeke, Luc; Bals, Sara; Popper, Zoë A; de Araujo Mariath, Jorge Ernesto

2013-06-01

213

Increased leaf angle1, a Raf-like MAPKKK that interacts with a nuclear protein family, regulates mechanical tissue formation in the Lamina joint of rice.  

PubMed

Mitogen-activated protein kinase kinase kinases (MAPKKKs), which function at the top level of mitogen-activated protein kinase cascades, are clustered into three groups. However, no Group C Raf-like MAPKKKs have yet been functionally identified. We report here the characterization of a rice (Oryza sativa) mutant, increased leaf angle1 (ila1), resulting from a T-DNA insertion in a Group C MAPKKK gene. The increased leaf angle in ila1 is caused by abnormal vascular bundle formation and cell wall composition in the leaf lamina joint, as distinct from the mechanism observed in brassinosteroid-related mutants. Phosphorylation assays revealed that ILA1 is a functional kinase with Ser/Thr kinase activity. ILA1 is predominantly resident in the nucleus and expressed in the vascular bundles of leaf lamina joints. Yeast two-hybrid screening identified six closely related ILA1 interacting proteins (IIPs) of unknown function. Using representative IIPs, the interaction of ILA1 and IIPs was confirmed in vivo. IIPs were localized in the nucleus and showed transactivation activity. Furthermore, ILA1 could phosphorylate IIP4, indicating that IIPs may be the downstream substrates of ILA1. Microarray analyses of leaf lamina joints provided additional evidence for alterations in mechanical strength in ila1. ILA1 is thus a key factor regulating mechanical tissue formation at the leaf lamina joint. PMID:22207574

Ning, Jing; Zhang, Baocai; Wang, Nili; Zhou, Yihua; Xiong, Lizhong

2011-12-01

214

Compartments in the organum vasculosum laminae terminalis of the rat and their delineation against the outer cerebrospinal fluid-containing space  

Microsoft Academic Search

Using intravenously injected horseradish peroxidase (HRP) as tracer, we demonstrate, that — in contrast to other neurohemal regions — the organum vasculosum laminae terminalis (OVLT) is composed of two functionally different divisions. Both parts of the OVLT are endowed with fenestrated capillaries which, however, obviously differ in their permeability for HRP. In one of these portions the neurohemal region remains

Brigitte Krisch; Helmut Leonhardt; Andreas Oksche

1987-01-01

215

The Correlation Between the Distribution of the NK, Receptor and the Actions of Tachykinin Agonists in the Dorsal Horn of the Rat Indicates That Substance P Does Not Have a Functional Role on Substantia Gelatinosa (Lamina II) Neurons  

Microsoft Academic Search

The presence of substance P in primary afferents that ter- minate in the outer laminae of the spinal cord has led to considerable interest in the function of this neuropeptide in nociception. We have examined the actions of tachykinin agonists on the membrane potential of neurons in lamina II of a neonatal spinal cord slice preparation in vitro. Only 10.5%

L. Bleazard; R. G. Hill; Merck Sharp

1994-01-01

216

Accumulation of components of basal laminae: association with the failure of neural crest cells to colonize the presumptive aganglionic bowel of ls/ls mutant mice.  

PubMed

Aganglionosis occurs in the terminal colon of the ls/ls mouse because an intrinsic defect of the presumptive aganglionic tissue prevents the entry and colonization of this portion of the bowel by migrating neural crest cells. The current study was undertaken to determine if abnormalities of the extracellular matrix could be identified in this segment that might account for migratory failure. Since basal laminae of the muscularis mucosa are overproduced in the aganglionic segment of adult ls/ls mice, we examined components of basal laminae in fetal gut from Day E 11 to Day E 16 of gestation. This period spans the time of enteric ganglion formation. Laminin and collagen type IV were studied by immunocytochemistry and proteoglycans by staining glycosaminoglycans with Alcian blue. Abnormalities of each of these components occur during development of the presumptive aganglionic bowel in the ls/ls mouse and could be detected as early as Day E 11. These defects consist mainly of an overabundance of these materials, both in defined basal laminae and throughout the extracellular space of the mesenchyme. Electron microscopic observations in the presumptive aganglionic ls/ls colon revealed a thickening of basal laminae and exceptionally wide intercellular spaces between smooth muscle myoblasts that contained an irregular fibrillar material, consisting of 4.5- to 6.0-nm filaments associated with 14- to 20-nm granules. Fibrillar and flocculant material was continuous with formed basal laminae, and was concentrated in the same areas found to have an overabundance of laminin immunoreactivity. These observations indicate that there is an accumulation of extracellular matrix material, including components of basal laminae, that (i) precedes the formation of enteric ganglia, (ii) is in the path through which enteric neural precursors from the crest would have to migrate, and (iii) is limited to the aganglionic and hypoganglionic ls/ls bowel. These data are consistent with the hypothesis that components of basal laminae contribute to the inability of crest cells to colonize the terminal bowel of ls/ls mice. PMID:3338619

Payette, R F; Tennyson, V M; Pomeranz, H D; Pham, T D; Rothman, T P; Gershon, M D

1988-02-01

217

The chemerin receptor 23 agonist, chemerin, attenuates monosynaptic C-fibre input to lamina I neurokinin 1 receptor expressing rat spinal cord neurons in inflammatory pain  

PubMed Central

Background Recent evidence has shown that the chemerin receptor 23 (ChemR23) represents a novel inflammatory pain target, whereby the ChemR23 agonists, resolvin E1 and chemerin, can inhibit inflammatory pain hypersensitivity, by a mechanism that involves normalisation of potentiated spinal cord responses. This study has examined the ability of the ChemR23 agonist, chemerin, to modulate synaptic input to lamina I neurokinin 1 receptor expressing (NK1R+) dorsal horn neurons, which are known to be crucial for the manifestation of inflammatory pain. Results Whole-cell patch-clamp recordings from pre-identified lamina I NK1R+ neurons, in rat spinal cord slices, revealed that chemerin significantly attenuates capsaicin potentiation of miniature excitatory postsynaptic current (mEPSC) frequency, but is without effect in non-potentiated conditions. In tissue isolated from complete Freund’s adjuvant (CFA) treated rats, chemerin significantly reduced the peak amplitude of monosynaptic C-fibre evoked excitatory postsynaptic currents (eEPSCs) in a subset of lamina I NK1R+ neurons, termed chemerin responders. However, chemerin did not alter the peak amplitude of monosynaptic C-fibre eEPSCs in control tissue. Furthermore, paired-pulse recordings in CFA tissue demonstrated that chemerin significantly reduced paired-pulse depression in the subset of neurons classified as chemerin responders, but was without effect in non-responders, indicating that chemerin acts presynaptically to attenuate monosynaptic C-fibre input to a subset of lamina I NK1R+ neurons. Conclusions These results suggest that the reported ability of ChemR23 agonists to attenuate inflammatory pain hypersensitivity may in part be due to a presynaptic inhibition of monosynaptic C-fibre input to lamina I NK1R+ neurons and provides further evidence that ChemR23 represents a promising inflammatory pain target.

2014-01-01

218

Intracellular Parasite Invasion Strategies  

NASA Astrophysics Data System (ADS)

Intracellular parasites use various strategies to invade cells and to subvert cellular signaling pathways and, thus, to gain a foothold against host defenses. Efficient cell entry, ability to exploit intracellular niches, and persistence make these parasites treacherous pathogens. Most intracellular parasites gain entry via host-mediated processes, but apicomplexans use a system of adhesion-based motility called ``gliding'' to actively penetrate host cells. Actin polymerization-dependent motility facilitates parasite migration across cellular barriers, enables dissemination within tissues, and powers invasion of host cells. Efficient invasion has brought widespread success to this group, which includes Toxoplasma, Plasmodium, and Cryptosporidium.

Sibley, L. D.

2004-04-01

219

Differential global and extra-cellular matrix focused gene expression patterns between normal and glaucomatous human lamina cribrosa cells  

PubMed Central

Purpose Marked extracellular matrix (ECM) remodeling occurs in the human optic nerve head in primary open angle glaucoma (POAG). The glial fibrillary acid protein (GFAP) negative lamina cribrosa cell may play an important role in this remodeling process. We report the first study of global and ECM-focused gene transcription differentials between GFAP-negative lamina cribrosa (LC) cells from normal and POAG human donors. Methods GFAP-negative LC cell lines were generated from the optic nerve tissue of four normal (n=4) and four POAG (n=4) human donors. Using Affymetrix U133A arrays the transcriptional profile between the normal and diseased groups were compared. Bioinformatic analysis was performed using robust multichip average (RMA Express) and EASE/David. Real time TaqMan PCR and immunohistochemistry analyses were performed to validate the microarray data. Results 183 genes were upregulated by greater than 1.5 fold and 220 were down regulated by greater than 1.5 fold in the POAG LC cells versus normal controls. Upregulated genes in POAG LC cells included, transforming growth factor beta 1 (TGF?1), secreted acid protein cysteine rich (SPARC), periostin (POSTN), thrombospondin-1 (THBS1), cartilage linking protein-1 (CRTL-1), and collagen type I (COL1A1), collagen type V (COL5A1), and collagen type XI (COL11A1). Downregulated ECM genes in POAG included fibulin 1 (FBLN1), decorin (DCN), and collagen type XVIII (COL18A1). All TaqMan PCR validation assays were significant (*p<0.05) and consistent with the array data. Immunohistochemistry of one target (periostin) confirmed its differential expression at the protein level in POAG optic nerve head tissue compared with non-glaucomatous controls. Functional annotation and over-representation analysis identified ECM genes as a statistically over-represented class of genes in POAG LC cells compared with normal LC cells. Conclusions This study reports for the first time that POAG LC cells in-vitro demonstrate upregulated ECM and pro-fibrotic gene expression compared with normal LC cells. This may be a pathological characteristic of this cell type in POAG in-vivo. We believe that the LC cell may be a pivotal regulator of optic nerve head ECM remodeling in POAG and an attractive target for molecular therapeutic strategies in the future.

Wordinger, Robert J.; Clark, Abbot F.; O'Brien, Colm J.

2009-01-01

220

The stress-strain relationships in wood and fiber-reinforced plastic laminae of reinforced glued-laminated wood beams  

NASA Astrophysics Data System (ADS)

The reinforcement of wood and wood composite structural products to improve their mechanical properties has been in practice for many years. Recently, the use of high-strength fiber-reinforced plastic (FRP) as a reinforcement in such applications has been commercialized. The reinforcement is manufactured using a standard pultrusion process or alternatively a sheet-forming process commonly referred to as "pulforming". The high-modulus fibers are predominately unidirectional, although off-axis fibers are often used to enhance off-axis properties. The fibers used are either of a single type or multiple types, which are called "hybrids". Unidirectional, single, and hybrid fiber FRP physical properties and characteristics were compared to wood. Full-scale reinforced glulams were tested. Aramid-reinforced plastics (ARP) used as tensile reinforcements were found to be superior in strength applications to other types of FRP made with fiber, such as carbon and fiberglass. Carbon/aramid-reinforced plastic (CARP) was shown to be superior in both modulus and strength design situations. Fiberglass was shown to be suitable only in hybrid situations with another fiber such as aramid or carbon and only in limited use situations where modulus was a design criteria. The testing and analysis showed that the global response of reinforced glulam beams is controlled by localized strength variations in the wood such as slope of grain, knots, finger joints, etc. in the tensile zone. The elemental tensile strains in the extreme wood tensile laminae, due to global applied loads, were found to be well below the strain at failure in clear wood samples recovered from the failure area. Two areas affecting the relationship between the wood and the FRP were investigated: compatibility of the wood and FRP materials and interface characteristics between the wood and FRP. The optimum strain value at yield point for an FRP was assessed to be slightly higher than the clear wood value in tension for a species/grade to be reinforced. The effects of localized strength variations in the tensile wood laminae adjacent to the FRP were found to be the predominate cause of failure in full-scale reinforced glulams with less than 1.5% by cross section reinforcement.

Tingley, Daniel Arthur

221

Invasion percolation with memory  

NASA Astrophysics Data System (ADS)

Motivated by the problem of finding the minimum threshold path (MTP) in a lattice of elements with random thresholds ?i, we propose a new class of invasion processes, in which the front advances by minimizing or maximizing the measure Sn=?i?ni for real n. This rule assigns long-time memory to the invasion process. If the rule minimizes Sn (case of minimum penalty), the fronts are stable and connected to invasion percolation in a gradient [J. P. Hulin, E. Clement, C. Baudet, J. F. Gouyet, and M. Rosso, Phys. Rev. Lett. 61, 333 (1988)] but in a correlated lattice, with invasion percolation [D. Wilkinson and J. F. Willemsen, J. Phys. A 16, 3365 (1983)] recovered in the limit \\|n\\|=?. For small n, the MTP is shown to be related to the optimal path of the directed polymer in random media (DPRM) problem [T. Halpin-Healy and Y.-C. Zhang, Phys. Rep. 254, 215 (1995)]. In the large n limit, however, it reduces to the backbone of a mixed site-bond percolation cluster. The algorithm allows for various properties of the MTP and the DPRM to be studied. In the unstable case (case of maximum gain), the front is a self-avoiding random walk.

Kharabaf, Hooshang; Yortsos, Yanis C.

1997-06-01

222

Invasion Ecology (Teacher's Guide)  

NSDL National Science Digital Library

Strange intruders are invading our part of the world, threatening our environment and our economy. These newcomers and their impact on our ecological balance are the focus of Invasion Ecology, a new book that teaches students to investigate the behaviors of nonnative and native species. Studying real-life invaders such as purple loosestrife and Phragmites, students will learn about the links between biology and ecology -- and explore how scientists are fighting these aggressors with biological controls. The Teacher's Edition explains how to guide highly sophisticated inquiry and conduct interactive research. Materials are classroom-ready and include detailed background information as well as sample assessment tasks and rubrics.The companion Student Edition has three sections: � Background on the science of ecology and its place in the control of invasive species � Protocols for practicing methods that scientists use in monitoring invasive species, such as early detection surveys, plot sampling, transect surveys, and decomposition studies � A series of helpful worksheets to guide students through their own interactive research Invasion Ecology is the second volume in the four-part Environmental Inquiry curriculum series, designed to show students how to apply scientific knowledge to solving real-life problems.

Krasny, Marianne E.; Team, The E.

2003-01-01

223

Early Primary Invasion Scientists  

ERIC Educational Resources Information Center

"We really need to get the government involved," said one student, holding his graph up to USDA scientist Steve Seefeldt. Dr. Steve studies methods to control "invasive" plants, plants that have been introduced to an area by humans and have potential to spread rapidly and negatively affect ecosystems. The first grader and his classmates had become…

Spellman, Katie V.; Villano, Christine P.

2011-01-01

224

Evolutionary genetics of invasive species  

Microsoft Academic Search

The evolutionary genetics of invasive species has been relatively unexplored, but could offer insights into mechanisms of invasions. Recent studies suggest that the invasion success of many species might depend more heavily on their ability to respond to natural selection than on broad physiological tolerance or plasticity. Thus, these studies stress the importance of genetic architecture, selection upon which could

Carol Eunmi Lee

2002-01-01

225

Risk Assessment for Invasive Species  

Microsoft Academic Search

Although estimates vary, there is a broad agreement that invasive species impose major costs on the U.S. economy, as well as posing risks to nonmarket environmental goods and services and to public health. The domestic effort to manage risks associated with invasive species is coordinated by the National Invasive Species Council (NISC), which is charged with devel- oping a science-based

Mark C. Andersen; Heather Adams; Bruce Hope; Mark Powell

2004-01-01

226

A bioinformatics analysis of Lamin-A regulatory network: a perspective on epigenetic involvement in Hutchinson-Gilford progeria syndrome.  

PubMed

Hutchinson-Gilford progeria syndrome (HGPS) is a rare human genetic disease that leads to premature aging. HGPS is caused by mutation in the Lamin-A (LMNA) gene that leads, in affected young individuals, to the accumulation of the progerin protein, usually present only in aging differentiated cells. Bioinformatics analyses of the network of interactions of the LMNA gene and transcripts are presented. The LMNA gene network has been analyzed using the BioGRID database (http://thebiogrid.org/) and related analysis tools such as Osprey (http://biodata.mshri.on.ca/osprey/servlet/Index) and GeneMANIA ( http://genemania.org/). The network of interaction of LMNA transcripts has been further analyzed following the competing endogenous (ceRNA) hypotheses (RNA cross-talk via microRNAs [miRNAs]) and using the miRWalk database and tools (www.ma.uni-heidelberg.de/apps/zmf/mirwalk/). These analyses suggest particular relevance of epigenetic modifiers (via acetylase complexes and specifically HTATIP histone acetylase) and adenosine triphosphate (ATP)-dependent chromatin remodelers (via pBAF, BAF, and SWI/SNF complexes). PMID:22533413

Arancio, Walter

2012-04-01

227

3D modeling to characterize lamina cribrosa surface and pore geometries using in vivo images from normal and glaucomatous eyes  

PubMed Central

En face adaptive optics scanning laser ophthalmoscope (AOSLO) images of the anterior lamina cribrosa surface (ALCS) represent a 2D projected view of a 3D laminar surface. Using spectral domain optical coherence tomography images acquired in living monkey eyes, a thin plate spline was used to model the ALCS in 3D. The 2D AOSLO images were registered and projected onto the 3D surface that was then tessellated into a triangular mesh to characterize differences in pore geometry between 2D and 3D images. Following 3D transformation of the anterior laminar surface in 11 normal eyes, mean pore area increased by 5.1 ± 2.0% with a minimal change in pore elongation (mean change = 0.0 ± 0.2%). These small changes were due to the relatively flat laminar surfaces inherent in normal eyes (mean radius of curvature = 3.0 ± 0.5 mm). The mean increase in pore area was larger following 3D transformation in 4 glaucomatous eyes (16.2 ± 6.0%) due to their more steeply curved laminar surfaces (mean radius of curvature = 1.3 ± 0.1 mm), while the change in pore elongation was comparable to that in normal eyes (?0.2 ± 2.0%). This 3D transformation and tessellation method can be used to better characterize and track 3D changes in laminar pore and surface geometries in glaucoma.

Sredar, Nripun; Ivers, Kevin M.; Queener, Hope M.; Zouridakis, George; Porter, Jason

2013-01-01

228

Effect of intravenous captopril on c-fos expression induced by sodium depletion in neurons of the lamina terminalis.  

PubMed

Peripheral administration of the angiotensin converting enzyme (ACE) inhibitor, captopril, and the central infusion of sarile, an angiotensin II (Ang II) receptor antagonist, were used to evaluate the role of renal and brain generated Ang II in sodium depletion-induced production of Fos in cells of the subfornical organ (SFO) and organum vasculosum lamina terminalis (OVLT). Pretreatment with intravenous captopril (100 mg/kg) significantly inhibited the c-fos expression induced by sodium depletion in the SFO and OVLT. In contrast, continuous intracerebroventricular infusion of sarile (22.5 micrograms/4.5 h, 5 microliters/h) did not affect the expected pattern of c-fos expression observed in both nuclei, 4 h after peritoneal dialysis. These results show that systemic interference with the angiotensin system of renal origin by captopril inhibited the production of Fos induced by sodium depletion in cells of the SFO and OVLT. These findings are consistent with the hypothesis that a rise in peripheral Ang II levels, triggered by sodium deficiency, could be an important mediator of the physiological and behavioral responses that lead to the restoration of sodium balance. In addition, this study suggests that increased circulating Ang II levels in response to body sodium deficit can directly stimulate neural pathways in the SFO and OVLT. PMID:9323436

Pastuskovas, C; Vivas, L

1997-01-01

229

The nuclear envelope lamina network has elasticity and a compressibility limit suggestive of a molecular shock absorber.  

PubMed

Mechanical properties of the nuclear envelope have implications for cell and nuclear architecture as well as gene regulation. Using isolated Xenopus oocyte nuclei, we have established swelling conditions that separate the intact nuclear envelope (membranes, pore complexes and underlying lamin filament network) from nucleoplasm and the majority of chromatin. Swelling proves reversible with addition of high molecular mass dextrans. Micropipette aspiration of swollen and unswollen nuclear envelopes is also reversible and yields a network elastic modulus, unaffected by nucleoplasm, that averages 25 mN/m. Compared to plasma membranes of cells, the nuclear envelope is much stiffer and more resilient. Our results suggest that the nuclear lamina forms a compressed network shell of interconnected rods that is extensible but limited in compressibility from the native state, thus acting as a 'molecular shock absorber'. In light of the conservation of B-type lamins in metazoan evolution, the mechanical properties determined in this investigation suggest physical mechanisms by which mutated lamins can either destabilize nuclear architecture or influence nuclear responses to mechanical signals in Emery-Dreifuss muscular dystrophy, cardiomyopathy, progeria syndromes (premature 'aging') and other laminopathies. PMID:15331638

Dahl, Kris Noel; Kahn, Samuel M; Wilson, Katherine L; Discher, Dennis E

2004-09-15

230

Lamina-associated polypeptide-1 interacts with the muscular dystrophy protein emerin and is essential for skeletal muscle maintenance.  

PubMed

X-linked Emery-Dreifuss muscular dystrophy is caused by loss of function of emerin, an integral protein of the inner nuclear membrane. Yet emerin null mice are essentially normal, suggesting the existence of a critical compensating factor. We show that the lamina-associated polypeptide1 (LAP1) interacts with emerin. Conditional deletion of LAP1 from striated muscle causes muscular dystrophy; this pathology is worsened in the absence of emerin. LAP1 levels are significantly higher in mouse than human skeletal muscle, and reducing LAP1 by approximately half in mice also induces muscle abnormalities in emerin null mice. Conditional deletion of LAP1 from hepatocytes yields mice that exhibit normal liver function and are indistinguishable from littermate controls. These results establish that LAP1 interacts physically and functionally with emerin and plays an essential and selective role in skeletal muscle maintenance. They also highlight how dissecting differences between mouse and human phenotypes can provide fundamental insights into disease mechanisms. PMID:24055652

Shin, Ji-Yeon; Méndez-López, Iván; Wang, Yuexia; Hays, Arthur P; Tanji, Kurenai; Lefkowitch, Jay H; Schulze, P Christian; Worman, Howard J; Dauer, William T

2013-09-30

231

Quantification of Apoplastic Potassium Content by Elution Analysis of Leaf Lamina Tissue from Pea (Pisum sativum L. cv Argenteum) 1  

PubMed Central

K+ content and concentration within the apoplast of mesophyll tissue of pea (Pisum sativum L., cv Argenteum) leaflets were determined using an elution procedure. Following removal of the epidermis, a 1 centimeter (inside diameter) glass cylinder was attached to the exposed mesophyll tissue and filled with 5 millimolar CaCl2 solution (1°C). From time-course curves of cumulative K+ diffusion from the tissue, the amount of K+ of extracellular origin was estimated. Apoplastic K+ contents for leaves from plants cultured in nutrient solution containing 2 or 10 millimolar K+ were found to range from 1 to 4.5 micromoles per gram fresh weight, comprising less than 3% of the total K+ content within the lamina tissue. Assuming an apoplastic solution volume of 0.04 to 0.1 milliliters per gram fresh weight and a Donnan cation exchange capacity of 2.63 micromoles per gram fresh weight (experimentally determined), the K+ concentration within apoplastic solution was estimated at 2.4 to 11.8 millimolar. Net movement of Rb+ label from the extracellular compartment within mesophyll tissue into the symplast was demonstrated by pulse-chase experiments. It was concluded that the mesophyll apoplast in pea has a relatively low capacitance as an ion reservoir. Apoplastic K+ content was found to be highly sensitive to changes in xylem solution concentration. Images Figure 1

Long, Jean M.; Widders, Irvin E.

1990-01-01

232

Understanding Invasion Ecology: Introduction  

NSDL National Science Digital Library

How can a single species of insect pose a threat to millions of acres of forests, orchards, and street trees? What can we do about the Asian longhorned beetle and other plants and animals that invade our farms, cities, and forests? The study of ecology helps us to find answers to these questions. Through applying ecological principles and conducting research, scientists are learning to manage invasive species. Students can learn alongside the scientists and, in some cases, help them. This chapter defines the term invasive species using a variety of examples--such as the Asian longhorned beetle and Chestnut Blight--and discusses their ecological implications. This free selection includes the Table of Contents and Preface.

Krasny, Marianne E.; Team, The E.

2003-01-01

233

Invasive salmonellosis in Malawi.  

PubMed

The incidence of invasive salmonellosis has increased among children and HIV-infected adults in Malawi. This has been associated with the emergence of drug resistance in the non-typhoidal Salmonella serovars Enteritidis and Typhimurium. In contrast, S. Typhi isolates have remained fully sensitive to commonly used antibiotics and the estimated incidence of typhoid fever, although still present, has fallen slightly among both adults and children. Infection with S. Typhi is not closely associated with underlying immunosuppression but it is possible that the non-typhoidal Salmonellae have adapted to the person-person human transmission niche in this frequently immunosuppressed population. The huge burden of invasive salmonellosis in Malawi, the high associated mortality, and the recent emergence of drug resistance emphasise the need for a better understanding of the epidemiology and the need for vaccine development. PMID:19745520

Gordon, Melita A; Graham, Stephen M

2008-01-01

234

Optic nerve degeneration in the DBA\\/2NNia mouse: is the lamina cribrosa important in the development of glaucomatous optic neuropathy?  

Microsoft Academic Search

To study optic nerve (ON) degeneration in the DBA\\/2NNia (DBA) mouse, a species lacking a lamina cribrosa and a model for secondary\\u000a angle-closure glaucoma, serial semi- and ultra-thin sectioning of the myelinated ON and of the ON head was performed and sections\\u000a evaluated qualitatively and quantitatively by light and electron microscopy. Immunohistochemistry was performed using antibodies\\u000a against collagen type I,

Christian Albrecht May; Thom Mittag

2006-01-01

235

Bending creep of glued laminated timber (glulam) using sugi ( Cryptomeria japonica ) laminae with extremely low Young’s modulus for the inner layers  

Microsoft Academic Search

The main purpose of this study was to establish whether sugi lumber with an extremely low Young’s modulus, which is plentifully\\u000a produced in southern Japan, can be practically used as laminae for glued laminated timber (glulam) from the viewpoint of long-term\\u000a performance under loading. Bending creep tests were carried out on sugi (Cryptomeria japonica D. Don) glulam with extremely low

Shiro Aratake; Hideki Morita; Takanori Arima

236

Casein kinase II protein kinase is bound to lamina-matrix and phosphorylates lamin-like protein in isolated pea nuclei  

NASA Technical Reports Server (NTRS)

A casein kinase II (CK II)-like protein kinase was identified and partially isolated from a purified envelope-matrix fraction of pea (Pisum sativum L.) nuclei. When [gamma-32P]ATP was directly added to the envelope-matrix preparation, the three most heavily labeled protein bands had molecular masses near 71, 48, and 46 kDa. Protein kinases were removed from the preparation by sequential extraction with Triton X-100, EGTA, 0.3 M NaCl, and a pH 10.5 buffer, but an active kinase still remained bound to the remaining lamina-matrix fraction after these treatments. This kinase had properties resembling CK II kinases previously characterized from animal and plant sources: it preferred casein as an artificial substrate, could use GTP as efficiently as ATP as the phosphoryl donor, was stimulated by spermine, was calcium independent, and had a catalytic subunit of 36 kDa. Some animal and plant CK II kinases have regulatory subunits near 29 kDa, and a lamina-matrix-bound protein of this molecular mass was recognized on immunoblot by anti-Drosophila CK II polyclonal antibodies. Also found associated with the envelope-matrix fraction of pea nuclei were p34cdc2-like and Ca(2+)-dependent protein kinases, but their properties could not account for the protein kinase activity bound to the lamina. The 71-kDa substrate of the CK II-like kinase was lamin A-like, both in its molecular mass and in its cross-reactivity with anti-intermediate filament antibodies. Lamin phosphorylation is considered a crucial early step in the entry of cells into mitosis, so lamina-bound CK II kinases may be important control points for cellular proliferation.

Li, H.; Roux, S. J.

1992-01-01

237

The effects of fenestration of the interpeduncular cistern membrane arousted to the opening of lamina terminalis in patients with ruptured ACoA aneurysms: a prospective, comparative study  

Microsoft Academic Search

Summary  Background. The incidence of chronic hydrocephalus requiring shunt placement is a well-known and common complication of aneurysmal subarachnoid\\u000a hemorrhage (aSAH). It was suggested that fenestration of the lamina terminalis (LT) during microsurgery for aSAH may be associated\\u000a with a reduced rate of shunt-dependent chronic hydrocephalus (SDCH). We analyzed that, fenestrations of the LT and Liliequist\\u000a membrane (LM) would reduce rate

M. Akyuz; R. Tuncer

2006-01-01

238

Components of the Basal Lamina and Dystrophin-Dystroglycan Complex in the Neurointermediate Lobe of Rat Pituitary Gland: Different Localizations of ?-Dystroglycan, Dystrobrevins, ?1-Syntrophin, and Aquaporin-4  

PubMed Central

The so-called neurointermediate lobe is composed of the intermediate and neural lobes of the pituitary. The present immunohistochemical study investigated components of the basal lamina (laminin, agrin, and perlecan), the dystrophin–dystroglycan complex (dystrophin, ?-dystroglycan, ?1-dystrobrevin, ?-dystrobrevin, utrophin, and ?1-syntrophin), and the aquaporins (aquaporin-4 and -9). Glia markers (GFAP, S100, and glutamine synthetase) and components of connective tissue (collagen type I and fibronectin) were also labeled. In the neurohypophysis, immunostaining of basal lamina delineated meningeal invaginations. In these invaginations, vessels were seen to penetrate the organ without submerging into its parenchyma. On the parenchymal side of the invaginations, ?-dystroglycan was detected, whereas utrophin was detected in the walls of vessels. Immunostaining of ?1-dystrobrevin and ?1-syntrophin did not delineate the vessels. The cells of the intermediate lobe were fully immunoreactive to ?1-dystrobrevin and ?1-syntrophin, whereas components of the basal lamina delineated the contours of the cells. GFAP-immunoreactive processes surrounded them. Aquaporin-4 localized at the periphery of the neurohypophysis, mainly adjacent to the intermediate lobe but not along the vessels. It colocalized only partially with GFAP and not at all with ?1-syntrophin. Aquaporin-9 was not detected. These results emphasize the possibility that the components of the dystrophin–dystroglycan complex localize differently and raise the question about the roles of dystrobrevins, ?1-syntrophin, and aquaporin-4 in the functions of the intermediate and neural lobes, respectively. (J Histochem Cytochem 58:463–479, 2010)

Pocsai, Karoly; Bagyura, Zsolt; Kalman, Mihaly

2010-01-01

239

In Vivo Lamina Cribrosa Micro-Architecture in Healthy and Glaucomatous Eyes as Assessed by Optical Coherence Tomography  

PubMed Central

Purpose. The lamina cribrosa (LC) is a prime location of glaucomatous damage. The purpose of this study was to compare LC 3-dimensional micro-architecture between healthy and glaucomatous eyes in vivo by using optical coherence tomography (OCT). Methods. Sixty-eight eyes (19 healthy and 49 glaucomatous) from 47 subjects were scanned in a 3.5 × 3.5 × 3.64-mm volume (400 × 400 × 896 pixels) at the optic nerve head by using swept-source OCT. The LC micro-architecture parameters were measured on the visible LC by an automated segmentation algorithm. The LC parameters were compared to diagnosis and visual field mean deviation (VF MD) by using a linear mixed effects model accounting for age. Results. The average VF MD for the healthy and glaucomatous eyes was ?0.50 ± 0.80 dB and ?7.84 ± 8.75 dB, respectively. Beam thickness to pore diameter ratio (P = 0.04) and pore diameter standard deviation (P < 0.01) were increased in glaucomatous eyes. With worse MD, beam thickness to pore diameter ratio (P < 0.01), pore diameter standard deviation (P = 0.05), and beam thickness (P < 0.01) showed a statistically significant increase while pore diameter (P = 0.02) showed a significant decrease. There were no significant interactions between any of the parameters and age (all P > 0.05). Conclusions. Glaucomatous micro-architecture changes in the LC, detected by OCT analysis, reflect beams remodeling and axonal loss leading to reduction in pore size and increased pore size variability.

Wang, Bo; Nevins, Jessica E.; Nadler, Zach; Wollstein, Gadi; Ishikawa, Hiroshi; Bilonick, Richard A.; Kagemann, Larry; Sigal, Ian A.; Grulkowski, Ireneusz; Liu, Jonathan J.; Kraus, Martin; Lu, Chen D.; Hornegger, Joachim; Fujimoto, James G.; Schuman, Joel S.

2013-01-01

240

The organum vasculosum laminae terminalis in immune-to-brain febrigenic signaling: a reappraisal of lesion experiments.  

PubMed

The organum vasculosum laminae terminalis (OVLT) has been proposed to serve as the interface for blood-to-brain febrigenic signaling, because ablation of this structure affects the febrile response. However, lesioning the OVLT causes many "side effects" not fully accounted for in the fever literature. By placing OVLT-lesioned rats on intensive rehydration therapy, we attempted to prevent these side effects and to evaluate the febrile response in their absence. After the OVLT of Sprague-Dawley rats was lesioned electrolytically, the rats were given access to 5% sucrose for 1 wk to stimulate drinking. Sucrose consumption and body mass were monitored. The animals were examined twice a day for signs of dehydration and treated with isotonic saline (50 ml/kg sc) when indicated. This protocol eliminated mortality but not several acute and chronic side effects stemming from the lesion. The acute effects included adipsia and gross (14% of body weight) emaciation; chronic effects included hypernatremia, hyperosmolality, a suppressed drinking response to hypertonic saline, and previously unrecognized marked (by approximately 2 degrees C) and long-lasting (>3 wk) hyperthermia. Because the hyperthermia was not accompanied by tail skin vasoconstriction, it likely reflected increased thermogenesis. After the rats recovered from the acute (but not chronic) side effects, their febrile response to IL-1beta (500 ng/kg iv) was tested. The sham-operated rats developed typical monophasic fevers ( approximately 0.5 degrees C), the lesioned rats did not. However, the absence of the febrile response in the OVLT-lesioned rats likely resulted from the untreatable side effects. For example, hyperthermia at the time of pyrogen injection was high enough (39-40 degrees C) to solely prevent fever from developing. Hence, the changed febrile responsiveness of OVLT-lesioned animals is given an alternative interpretation, unrelated to febrigenic signaling to the brain. PMID:12714358

Romanovsky, Andrej A; Sugimoto, Naotoshi; Simons, Christopher T; Hunter, William S

2003-08-01

241

Relationship between the Lamina Cribrosa, Outer Retina, and Choroidal Thickness as Assessed Using Spectral Domain Optical Coherence Tomography  

PubMed Central

Purpose To evaluate the characteristics and relationship between peripapillary choroidal thickness (pCT), lamina cribrosa thickness (LCT), and peripapillary outer retinal layer thickness (pORT) as determined using spectral domain optical coherence tomography (SD-OCT) enhanced depth imaging (EDI). Methods In total, 255 participants were included (87 healthy subjects, 87 glaucoma suspects (GS), and 81 glaucoma cases). The pORT, defined as the thickness between the posterior outer plexiform layer and the retinal pigment epithelium (RPE) interface, and the pCT, between the outer margin of the RPE and the choroidal-scleral interface, were manually measured using EDI scanning of the circumpapillary retinal nerve fiber layer (RNFL). LCT was determined by EDI scanning of the optic nerve head (ONH). Baseline characteristics, including axial length (AXL) and the SD-OCT measurements of the participants, were compared among the three groups. The correlation between putative factors and pCT was determined using univariate and multivariate linear regression analyses. Results In all three groups, both pORT and pCT were thinnest in the inferior area among the four quadrants. In the healthy group, the mean peripapillary RNFL, pORT, and LCT were significantly greater in comparison with those of the GS and glaucoma groups (p < 0.001, p < 0.038, and p < 0.001, respectively). The pCT demonstrated no significant differences among the three groups (p = 0.083). Only age and AXL were associated with pCT by multivariate analysis. Conclusions The pCT is substantially thinner in the inferior area of the ONH. In addition, the pCT demonstrates the strongest correlation with age and AXL, but was not associated with glaucoma or LCT.

Chung, Ho Seok; Lee, Kyoung Sub; Lee, Jong Rak; Kim, Soa

2014-01-01

242

Correlation between Local Stress and Strain and Lamina Cribrosa Connective Tissue Volume Fraction in Normal Monkey Eyes  

PubMed Central

Purpose. To investigate the biomechanical response to IOP elevation of normal monkey eyes using eye-specific, three-dimensional (3-D) finite element (FE) models of the ONH that incorporate lamina cribrosa (LC) microarchitectural information. Methods. A serial sectioning and episcopic imaging technique was used to reconstruct the ONH and peripapillary sclera of four pairs of eyes fixed at 10 mm Hg. FE models were generated with local LC material properties representing the connective tissue volume fraction (CTVF) and predominant LC beam orientation and used to simulate an increase in IOP from 10 to 45 mm Hg. An LC material stiffness constant was varied to assess its influence on biomechanical response. Results. Strains and stresses within contralateral eyes were remarkably similar in both magnitude and distribution. Strain correlated inversely, and nonlinearly, with CTVF (median, r 2 = 0.73), with tensile strains largest in the temporal region. Stress correlated linearly with CTVF (median r2 = 0.63), with the central and superior regions bearing the highest stresses. Net average LC displacement was either posterior or anterior, depending on whether the laminar material properties were compliant or stiff. Conclusions. The results show that contralateral eyes exhibit similar mechanical behavior and suggest that local mechanical stress and strain within the LC are correlate highly with local laminar CTVF. These simulations emphasize the importance of developing both high-resolution imaging of the LC microarchitecture and next-generation, deep-scanning OCT techniques to clarify the relationships between IOP-related LC displacement and CTVF-related stress and strain in the LC. Such imaging may predict sites of IOP-related damage in glaucoma.

Roberts, Michael D.; Liang, Yi; Sigal, Ian A.; Grimm, Jonathan; Reynaud, Juan; Bellezza, Anthony; Burgoyne, Claude F.

2010-01-01

243

Evaluation of lamina cribrosa tolerance to the increase of intraocular pressure in healthy people and primary open angle glaucoma patients.  

NASA Astrophysics Data System (ADS)

The assessment of optic nerve head (ONH) stability in measured short-term increase of intraocular pressure (IOP) in healthy group and initial primary open angle glaucoma (POAG) patients. METHODS: 147 healthy people were divided in two groups according to the age. The first one (59 people) was comprised of those who were from 16 to 35 years old. The second group included 88 healthy adults from 35 to 78. 64 patients (39 - 80 years old) with initial POAG were included in the third group. The mean cup depth (MCD) of the optic disc was determined with the Heidelberg retina tomographer (HRT II). After baseline examination a suction cup was used to increase IOP for 10 mm Hg above baseline and MCD was determined again. IOP level was controlled by Perkins" tonometer before and during suction. RESULTS: IOP increase always resulted in MCD increase. In group 1 mean increase was 18,3+/-1,96 ?m. In the second group the value was 22,4+/-2,63 ?m. There was no statistically significant difference in MCD mean increase values in groups 1 and 2 (t=1,46, p>0,05). In POAG group mean MCD increase was 49,2+/-8,41 ?m. The difference of this value was statistically significant when compared with that in group 2 (t=5,38, p<0,05). CONCLUSIONS: 1. There was no correlation between age and MCD mean increase in healthy people. 2. Results of the investigation permit us to establish criteria of normal and decreased stability of ONH to the induced elevation of IOP: we consider the MCD increase less than 25 ?m as normal, 25 - 40 ?m as borderline and more than 40 ?m as lack of lamina cribrosa stability.

Astakhov, Yury S.; Akopov, Evgeny L.

2005-01-01

244

The collagen fibril architecture in the lamina cribrosa and peripapillary sclera predicted by a computational remodeling approach.  

PubMed

The biomechanics of the optic nerve head is assumed to play an important role in ganglion cell loss in glaucoma. Organized collagen fibrils form complex networks that introduce strong anisotropic and nonlinear attributes into the constitutive response of the peripapillary sclera (PPS) and lamina cribrosa (LC) dominating the biomechanics of the optic nerve head. The recently presented computational remodeling approach (Grytz and Meschke in Biomech Model Mechanobiol 9:225-235, 2010) was used to predict the micro-architecture in the LC and PPS, and to investigate its impact on intraocular pressure-related deformations. The mechanical properties of the LC and PPS were derived from a microstructure-oriented constitutive model that included the stretch-dependent stiffening and the statistically distributed orientations of the collagen fibrils. Biomechanically induced adaptation of the local micro-architecture was captured by allowing collagen fibrils to be reoriented in response to the intraocular pressure-related loading conditions. In agreement with experimental observations, the remodeling algorithm predicted the existence of an annulus of fibrils around the scleral canal in the PPS, and a predominant radial orientation of fibrils in the periphery of the LC. The peripapillary annulus significantly reduced the intraocular pressure-related expansion of the scleral canal and shielded the LC from high tensile stresses. The radial oriented fibrils in the LC periphery reinforced the LC against transversal shear stresses and reduced LC bending deformations. The numerical approach presents a novel and reasonable biomechanical explanation of the spatial orientation of fibrillar collagen in the optic nerve head. PMID:20628781

Grytz, Rafael; Meschke, Günther; Jonas, Jost B

2011-06-01

245

Invasive mycoses: diagnostic challenges.  

PubMed

Despite the availability of newer antifungal drugs, outcomes for patients with invasive fungal infections (IFIs) continue to be poor, in large part due to delayed diagnosis and initiation of appropriate antifungal therapy. Standard histopathologic diagnostic techniques are often untenable in at-risk patients, and culture-based diagnostics typically are too insensitive or nonspecific, or provide results after too long a delay for optimal IFI management. Newer surrogate markers of IFIs with improved sensitivity and specificity are needed to enable earlier diagnosis and, ideally, to provide prognostic information and/or permit therapeutic monitoring. Surrogate assays should also be accessible and easy to implement in the hospital. Several nonculture-based assays of newer surrogates are making their way into the medical setting or are currently under investigation. These new or up-and-coming surrogates include antigens/antibodies (mannan and antimannan antibodies) or fungal metabolites (d-arabinitol) for detection of invasive candidiasis, the Aspergillus cell wall component galactomannan used to detect invasive aspergillosis, or the fungal cell wall component and panfungal marker ?-glucan. In addition, progress continues with use of polymerase chain reaction- or other nucleic acid- or molecular-based assays for diagnosis of either specific or generic IFIs, although the various methods must be better standardized before any of these approaches can be more fully implemented into the medical setting. Investigators are also beginning to explore the possibility of combining newer surrogate markers with each other or with more standard diagnostic approaches to improve sensitivity, specificity, and capacity for earlier diagnosis, at a time when fungal burden is still relatively low and more responsive to antifungal therapy. PMID:22196205

Ostrosky-Zeichner, Luis

2012-01-01

246

Bioterrorism and invasive species.  

PubMed

The risk of dispersing invasive species, especially human pathogens, through acts of bioterrorism, cannot be neglected. However, that risk appears quite low in comparison with the risk of dispersing animal pathogens that could dramatically burden the agricultural economy of food animal producing countries, such as Australia and countries in Europe and North and South America. Although it is not directly related to bioterrorism, the intentional release of non-native species, particularly undesired companion animals or wildlife, may also have a major economic impact on the environment and, possibly, on animal and human health, in the case of accidental release of zoonotic agents. PMID:20919576

Chomel, B B; Sun, B

2010-08-01

247

Minimally invasive surgery.  

PubMed

Minimally invasive surgery (MIS), or laparoscopic surgery, plays a vital role in residency training in a number of surgical disciplines including general surgery, surgical oncology, colorectal surgery, pediatric surgery, and thoracic surgery. The tremendous patient demand for MIS over the past 2 decades has resulted in surgeons rapidly embracing this technique. Many general surgery residencies cover basic laparoscopy within their residency program; however, the experience with more advanced cases is more variable. This career resource guides the interested medical student and physician to opportunities for fellowship training in MIS. It includes a discussion of the specialty, training requirements, grant funding, research fellowships, and pertinent societies. PMID:20113703

Hamad, Giselle G; Curet, Myriam

2010-02-01

248

Dietary Flexibility Aids Asian Earthworm Invasion in North American Forests  

EPA Science Inventory

On a local scale, invasiveness of introduced species and invasibility of habitats together determine invasion success. A key issue in invasion ecology has been how to quantify the contribution of species invasiveness and habitat invasibility separately. Conventional approaches, s...

249

Non-invasive densitometry  

NASA Astrophysics Data System (ADS)

Several non-invasive methods are available to measure bone density in different regions of the skeleton. Bedrest and microgravity both lead to bone loss, which is more marked in the lower parts of the skeleton. The bone loss can be monitored by non-invasive techniques in longitudinal studies when precision (i.e. the ability to produce repeated measurements with the same value) is adequate. Bone mineral density (BMD) can be measured with single photon absorptiometry in the lower forearm and calcaneus and with dual energy X-ray absorptiometry (DXA) in almost any region of the skeleton. The latter technique pairs good precision with very low radiation exposure. With peripheral quantitative computed tomography very precise measurements of the lower forearm and tibia are feasible with low radiation dose. It has the additional option of separate measurement of cortical and trabecular bone. This could be of particular importance in microgravity studies, as trabecular bone loss is more severe in this condition. A new development is the measurement of ultrasound velocity or attenuation which depends on bone density and structure. Ultrasound data of the calcaneus correlate well with bone mineral density in spine and hip. The advantage of this technique is that it operates without radiation. However, the clinical value has to be established. The ultimate choice of technique and skeletal region for bone densitometry will depend on specific requirements.

Lips, Paul

250

Early Invasive Cervical Cancer  

PubMed Central

Purpose To compare MRI, CT, clinical exam and histopathological analysis for predicting lymph node involvement in women with cervical carcinoma, verified by lymphadenectomy. Methods A 25-center ACRIN/GOG study enrolled 208 patients with biopsy-proven invasive cervical cancer for MRI and CT prior to attempted curative radical hysterectomy. Each imaging study was interpreted prospectively by one onsite radiologist, and retrospectively by 4 independent offsite radiologists, all blinded to surgical, histopathological and other imaging findings. Likelihood of parametrial and uterine body involvement was rated on a 5-point scale. Tumor size measurements were attempted in 3 axes. Association with histologic lymph node involvement, scored as absent, pelvic only and common iliac or paraaortic, was evaluated using Cochran-Mantel Haenszel statistics, univariate and multivariate logistic regression, generalized estimating equations, accuracy statistics and ROC analysis. Results Lymphatic metastases were found in 34% of women; 13% had common iliac nodal metastases, and 9% had paraortic nodal metastases. Based on the retrospective multi-observer re-reads, average AUC for predicting histologic lymph node involvement between MRI and CT for tumor size were higher for MRI versus CT, although formal statistic comparisons could not be conducted. Multivariate analysis showed improved model fit incorporating predictors from MRI, but not CT, over and above the initial clinical and biopsy predictors, although the increase in discriminatory ability was not statistically significant. Conclusion MRI findings may help predict the presence of histologic lymph node involvement in women with early invasive cervical carcinoma, thus providing important prognostic information.

Mitchell, Donald G; Snyder, Bradley; Coakley, Fergus; Reinhold, Caroline; Thomas, Gillian; Amendola, Marco A.; Schwartz, Lawrence H; Woodward, Paula; Pannu, Harpreet; Atri, Mostafa; Hricak, Hedvig

2008-01-01

251

Nitric oxide synthase-cyclo-oxygenase pathways in organum vasculosum laminae terminalis: possible role in pyrogenic fever in rabbits.  

PubMed Central

1. Fever was induced in rabbits by administration of Escherichia coli endotoxin (lipopolysaccharide; LPS; 0.001-10 micrograms) into the organum vasculosum laminae terminalis (OVLT). Deep body temperature was evaluated over a period of 7 h. 2. The LPS-induced febrile response was mimicked by intra-OVLT injection of the nitric oxide (NO) donors, S-nitroso-acetylpenicillamine (SNAP, 1-10 micrograms), sodium nitroprusside (SNP, 50 micrograms), or hydroxylamine (10 micrograms), the cyclic GMP analogue 8-bromo-cyclic GMP (8-Br-cyclic GMP, 10-100 micrograms), or prostaglandin E2 (PGE2, 0.2 micrograms). 3. Dexamethasone (Dex, a potent inhibitor of the transcription of inducible NO synthase, iNOS, 10 micrograms), anisomycin (a protein synthesis inhibitor, 100 micrograms), L-N5-(1-iminoethyl)ornithine (L-NIO; an irreversible NOS inhibitor, 10-200 micrograms), aminoguanidine (a specific iNOS inhibitor, 1000 micrograms), or NG-methyl-L-arginine acetate (L-NMMA, a NOS inhibitor, 100 micrograms) inhibited fever induced by LPS when injected into the OVLT 1 h before LPS injection. An intra-OVLT dose of 1000 micrograms of NG-nitro-L-arginine methyl ester (L-NAME, a potent inhibitor of constitutive NOS) did not exhibit antipyretic effects. 4. Methylene blue (an inhibitor of NOS and soluble guanylate cyclase, 1-10 micrograms), 6-(phenylamino)-5,8-quinolinedione (LY-83583; an inhibitor of soluble guanylate cyclase and NO release, 20 micrograms), or indomethacin (an inhibitor of cyclo-oxygenase, COX, 400 micrograms) inhibited fever induced by LPS when injected into the OVLT 1 h before LPS injection. Pretreatment with methylene blue or haemoglobin (a NO scavenger, 100 micrograms) attenuated the fever induced by intra-OVLT injection of SNAP. 5. The PGE2-induced fever was potentiated, rather then attenuated, by pretreatment with an intra-OVLT dose of animoguanidine (1000 micrograms), L-NMMA (100 micrograms) or L-NIO (200 micrograms). 6. These results suggest that iNOS-COX pathways in the OVLT represent an important mechanism for modulation of pyrogenic fever in rabbits.

Lin, J. H.; Lin, M. T.

1996-01-01

252

Meeting the Invasive Species Challenge.  

National Technical Information Service (NTIS)

Invasive species affect each of our lives, all regions of the U.S., and every nation in the world. Society pays a great price for invasive species costs measured not just in dollars, but also in unemployment, damaged goods and equipment, power failures, f...

2001-01-01

253

Neural invasion in gastric carcinoma.  

PubMed Central

AIMS--To determine whether neural invasion in advanced gastric cancer is of clinicopathological significance. METHODS--The study population comprised 121 cases of primary advanced gastric carcinoma. Two paraffin wax embedded blocks taken from the central tissue slice in each primary tumour were used. For definitive recognition of neural invasion, immunostaining for S-100 protein was applied to one slide; the other slide was stained with haematoxylin and eosin. RESULTS--Neural invasion was recognised in 34 of 121 (28%) primary gastric carcinomas. There were significant differences in tumour size, depth of tumour invasion, stage, and curability between patients with and without neural invasion. The five year survival rates of patients with and without neural invasion were 10 and 50%, respectively. Multivariate analysis, however, demonstrated that neural invasion was not an independent prognostic factor. CONCLUSIONS--Neural invasion could be an additional useful factor for providing information about the malignant potential of gastric carcinoma. This may be analogous to vessel permeation which is thought to be important, but is not an independent prognostic factor. Images

Mori, M; Adachi, Y; Kamakura, T; Ikeda, Y; Maehara, Y; Sugimachi, K

1995-01-01

254

The minimally invasive open pyeloplasty  

Microsoft Academic Search

BackgroundThe dismembered pyeloplasty is the operation of choice for ureteropelvic junction obstruction (UPJO). Recently, with the advent of improved minimally invasive techniques and equipment, laparoscopic dismembered pyeloplasty has gained popularity. We present our experience with a minimally invasive open pyeloplasty.

Job K. Chacko; Martin A. Koyle; Gerald C. Mingin; Peter D. Furness

2006-01-01

255

Minimally Invasive Thoracic Surgery  

PubMed Central

To reduce the risk, trauma, and expense of intrathoracic surgical treatments, minimally invasive procedures performed with the assistance of fiberoptic video technology have been developed for thoracic and bronchial surgeries. The surgical treatment of nearly every intrathoracic condition can benefit from a video-assisted approach performed through a few small incisions. Video-assisted thoracoscopic and rigid-bronchoscopic surgery have improved the results of thoracic procedures by decreasing postoperative pain and speeding the return to normal activity. From January 1992 to February 2000, 185 patients underwent 189 video-assisted thoracoscopic procedures in Ochsner Foundation Hospital for various conditions with good results; only 18 procedures (9.5%) required conversion to open thoracotomy. Video-assisted rigid bronchoscopic surgery has been helpful in managing tracheobronchial conditions and complications following lung transplantation. Ninety-nine patients with bronchial complications following lung transplantation and 20 patients with tracheobronchial conditions not related to transplantation have undergone therapeutic techniques involving video-assisted rigid bronchoscopy.

McFadden, P. Michael

2000-01-01

256

Minimally Invasive Vascular Techniques  

PubMed Central

The recent and continuing developments in radiotherapy, gene therapy, and the technologies of imaging, materials, and devices, as well as the techniques for their implementation, have expanded the options available for the treatment of peripheral vascular disease. Though long-term data are still lacking, percutaneous transluminal angioplasty (PTA) has developed into a treatment modality in its own right and continues to be an adjuvant treatment to traditional surgical revascularization. Numerous stents and grafts are currently available for the treatment of arterial lesions and aneurysms, while the testing of many more continues. In addition to these new devices, developments in gene therapy and brachytherapy have brought several new minimally invasive options to the treatment of peripheral vascular disease.

Lepore, Michael R.; Yoselevitz, Moises; Sternbergh, W. Charles; Money, Samuel R.

2000-01-01

257

Minimally Invasive Esophagectomy  

PubMed Central

Objective: To assess our outcomes after minimally invasive esophagectomy (MIE). Summary Background Data: Esophagectomy has traditionally been performed by open methods. Results from most series include mortality rates in excess of 5% and hospital stays frequently greater than 10 days. MIE has the potential to improve these results, but only a few small series have been reported. This report summarizes our experience of 222 cases. Methods: From 1996 to 2002, MIE was performed in 222 patients. Indications for operation included high-grade dysplasia (n = 47) and cancer (n = 175). Neoadjuvant chemotherapy was used in 78 (35.1%) and radiation in 36 (16.2%). Initially, a laparoscopic transhiatal approach was used (n = 8), but subsequently our approach evolved to include thoracoscopic mobilization (n = 214). Results: There were 186 men and 36 women. Median age was 66.5 years (range, 39–89). Nonemergent conversion to open procedure was required in 16 patients (7.2%). MIE was successfully completed in 206 (92.8%) patients. The median intensive care unit stay was 1 day (range, 1–30); hospital stay was 7 days (range, 3–75). Operative mortality was 1.4% (n = 3). Anastomotic leak rate was 11.7% (n = 26). At a mean follow-up of 19 months (range, 1–68), quality of life scores were similar to preoperative values and population norms. Stage specific survival was similar to open series Conclusions: MIE offers results as good as or better than open operation in our center with extensive minimally invasive and open experience. In this single institution experience, we observed a lower mortality rate (1.4%) and shorter hospital stay (7 days) than most open series. Given these results, we are now developing an intergroup trial (ECOG 2202) to assess MIE in a multicenter setting.

Luketich, James D.; Alvelo-Rivera, Miguel; Buenaventura, Percival O.; Christie, Neil A.; McCaughan, James S.; Litle, Virginia R.; Schauer, Philip R.; Close, John M.; Fernando, Hiran C.

2003-01-01

258

Studies on deficiency of Schwann cell basal lamina and deformation of collagen fibres induced by beta-aminopropionitrile in cultures of developing rat peripheral neurons.  

PubMed Central

The morphological analysis in culture of superior cervical ganglia and dorsal root ganglia showed the following: (1) collagen fibres external to the neurite bundles were larger than those inside the neurite bundles in both control and BAPN-treated cultures; (2) there was much more irregularity of shape in external than in internal fibres in dorsal root ganglia with BAPN; (3) there was reduced basal lamina formation by Schwann cells in both types of ganglia (Okada & Bunge, 1981); (4) basal lamina formation in the superior cervical ganglion was reduced as the days of treatment with BAPN increased (from 94.7% with one day of treatment to 66.7% with 8 days of treatment; (5) in the dorsal root ganglion preparation, the myelin internode was shorter in BAPN (105.1 micron +/- 34.5 micron) than in control media (127.8 micron +/- 32.8 micron: P less than 0.001); (6) there was no significant difference in thickness of myelin between controls (2.9 micron +/- 0.9 micron) and those treated with BAPN (2.7 micron +/- 0.7 micron: 0.05 less than P less than 0.1); (7) the node of Ranvier was more elongated in BAPN (5.1 micron +/- 4.1 micron) than in control media (2.5 micron +/- 0.8 micron; P less than 0.01). The relationship between connective tissue abnormalities caused by BAPN and of the basal lamina formation of myelin-forming cells affected by BAPN is discussed. Images Fig. 4 Fig. 5

Ninomiya, T; Kobayashi, E O

1985-01-01

259

The somatostatin analogue octreotide inhibits capsaicin-mediated activation of nociceptive primary afferent fibres in spinal cord lamina II (substantia gelatinosa).  

PubMed

Somatostatin (SST) in spinal cord has been linked with the inhibition of nociceptive neurotransmission in several experimental paradigms. The SST2 receptor (SSTR2) is the main SST receptor subtype in the superficial dorsal horn (DH) and is activated, besides to the naïve peptide, by the SST synthetic analogue octreotide (OCT). In the present work, we have studied the central effects of SSTR2 activation on capsaicin (CAP)-induced glutamate release in mouse DH. In neurons of the lamina II of DH, CAP (2 ?M) induced a strong increase of mEPSC frequency that was significantly reduced (70%) by OCT. SSTR2 involvement was assessed by using the specific antagonist CYN 154806. No differences were observed between frequency increase in CAP alone vs. CAP in the presence of CYN 154806+OCT. The effect of OCT was further investigated by studying c-fos expression in spinal cord slices. The CAP-induced increase in density of Fos immunoreactive nuclei in the superficial DH was strongly prevented by OCT. SSTR2a (a splicing variant of SSTR2) immunoreactivity was found in both pre- and post-synaptic compartments of laminae I-II synapses. By light and electron microscopy, SSTR2a was mainly localized onto non-peptidergic isolectin B4 (IB4)-positive primary afferent fibres (PAFs). A subset of them was also found to express the CAP receptor TRPV1. These data show that the SST analogue OCT inhibits CAP-mediated activation of non-peptidergic nociceptive PAFs in lamina II. Our data indicate that SSTR2a plays an important role in the pre-synaptic modulation of central excitatory nociceptive transmission in mouse. PMID:21109472

Bencivinni, Ileana; Ferrini, Francesco; Salio, Chiara; Beltramo, Massimiliano; Merighi, Adalberto

2011-07-01

260

A non-invasive crop ideotype to reduce invasive potential  

Microsoft Academic Search

Summary  In plant breeding programs, qualitative and quantitative traits confer market value and, thus, constitute the basis for developing\\u000a breeding criteria during crop domestication. Some traits such as high male\\/female fertility are advantageous in the wild and\\u000a could enable the evolution of cultivated crops into invasive weeds. Other traits, e.g. sterility, are not expected to confer\\u000a invasiveness. To date there has

N. O. Anderson; N. Gomez; S. M. Galatowitsch

2006-01-01

261

Serotonin potentiates the response of neurons of the superficial laminae of the rat spinal dorsal horn to gamma-aminobutyric acid.  

PubMed

Employing the Nystatin-perforated whole-cell patch-clamp recording technique, the modulatory effects of serotonin (5-HT) on gamma-aminobutyric acid (GABA)-activated whole-cell currents were investigated in neurons acutely dissociated from the superficial laminae (laminae I and II) of the rat spinal dorsal horn. The results showed: (1) GABA acted on GABA(A) receptors and elicited inward Cl(-) currents (I(GABA)) at a holding potential (V(H)) of -40 mV; (2) 5-HT potentiated GABA-induced Cl(-) current without affecting the reversal potential of I(GABA) and the apparent affinity of GABA to its receptor; (3) alpha-methyl-5-HT, a selective agonist of 5-HT(2) receptor, mimicked the potentiation effect of 5-HT on I(GABA), whereas ketanserine, an antagonist of 5-HT(2) receptor, blocked the potentiation effect of 5-HT; (4) Chelerythrine, an inhibitor of protein kinase C, reduced the potentiation effect of 5-HT on I(GABA). The present results indicate: (1) The potentiation of 5-HT on I(GABA) is mediated by 5-HT(2) receptor and through a protein kinase-dependent transduction pathway; (2) The interactions between 5-HT and GABA might play an important role in the modulation of nociceptive information transmission at spinal cord level. PMID:10974497

Li, H; Lang, B; Kang, J F; Li, Y Q

2000-08-01

262

The defective nuclear lamina in Hutchinson-gilford progeria syndrome disrupts the nucleocytoplasmic Ran gradient and inhibits nuclear localization of Ubc9.  

PubMed

The mutant form of lamin A responsible for the premature aging disease Hutchinson-Gilford progeria syndrome (termed progerin) acts as a dominant negative protein that changes the structure of the nuclear lamina. How the perturbation of the nuclear lamina in progeria is transduced into cellular changes is undefined. Using patient fibroblasts and a variety of cell-based assays, we determined that progerin expression in Hutchinson-Gilford progeria syndrome inhibits the nucleocytoplasmic transport of several factors with key roles in nuclear function. We found that progerin reduces the nuclear/cytoplasmic concentration of the Ran GTPase and inhibits the nuclear localization of Ubc9, the sole E2 for SUMOylation, and of TPR, the nucleoporin that forms the basket on the nuclear side of the nuclear pore complex. Forcing the nuclear localization of Ubc9 in progerin-expressing cells rescues the Ran gradient and TPR import, indicating that these pathways are linked. Reducing nuclear SUMOylation decreases the nuclear mobility of the Ran nucleotide exchange factor RCC1 in vivo, and the addition of SUMO E1 and E2 promotes the dissociation of RCC1 and Ran from chromatin in vitro. Our data suggest that the cellular effects of progerin are transduced, at least in part, through reduced function of the Ran GTPase and SUMOylation pathways. PMID:21670151

Kelley, Joshua B; Datta, Sutirtha; Snow, Chelsi J; Chatterjee, Mandovi; Ni, Li; Spencer, Adam; Yang, Chun-Song; Cubeñas-Potts, Caelin; Matunis, Michael J; Paschal, Bryce M

2011-08-01

263

Invasive meningococcal disease.  

PubMed

Invasive meningococcal disease (IMD) is a major public health and continues to cause substantial mortality and morbidity. Serotype C is the most frequent in Brazil. The clinical spectrum of IMD is broad (meningitis, meningococcemia or both) and the clinical evolution may be unpredictable. Main features associated with mortality are: age higher than 50 years old, seizures, shock, and meningococcemia without meningitis. Blood cultures should be obtained immediately. Lumbar puncture can be performed without previous computed tomography scan (CT) in most cases. Clinical features can be useful to predic patients where an abnormal CT scan is likely. Cerebrospinal fluid (CSF) culture and Gram stain should always be required. Latex agglutination sensitivity is highly variable. Polymerase chain reaction is specially useful when other methods are negative or delayed. Usually ceftriaxone should not be delayed while awaiting CSF study or CT. Dexamethasone can be used in meningococcal meningitis. Early suspicion of IMD and antibiotic in primary care before hospitalization, rapid transportation to a hospital, and stabilization in an intensive-care unit has substantially reduced the case-fatality rate. Vaccines against serotypes A, C, W-135, and Y are available while vaccines against serotype B are expected. PMID:24141498

Strelow, Vanessa L; Vidal, Jose E

2013-09-01

264

Minimally invasive kidney transplantation.  

PubMed

Minimally invasive kidney transplantation (MIKT) procedures, starting with lymphocele fenestration and continuing with laparoscopic donor nephrectomy, have been performed in recipients since 2006. From November 2011 to May 2012, we performed 86 consecutive renal transplantation with 43 conventional kidney transplantations (COKT) and 43 MIKTs using an apendectomy like, 4 to 5-cm incision. There were no significant differences between the groups according to age, sex, body mass index, donor type, surgical side, donor kidney or artery number. Mean operative time in the MIKT group was 164.2 minutes versus 153.5 minutes in the COKT group. The cold ischemia times in MIKT and COKT groups were 60.8 and 63.3 minutes, respectively. The lengths of hospital stay, blood creatinine levels at postoperative days 7, 30, and 90, and the 90th day creatinine clearances were similar. In conclusion, considering that the complication rate was equal and the graft functions equal, MIKT seemed to be a safe method for renal transplantation. PMID:23622589

Kaçar, S; Ero?lu, A; Tilif, S; Güven, B

2013-04-01

265

Minimally invasive radioguided parathyroidectomy.  

PubMed

In the last years, with the aim of reducing operative time and having better cosmetic results, minimally-invasive parathyroidectomy (MIP) has become to be extensively performed. Several techniques are available, including video-endoscopic techniques, and radioguided parathyroidectomy. In patients undergoing radio-guided parathyroidectomy receive an intravenous injection of 99mTc-sestamibi 60-90 minutes before the operation was scheduled to start. Four early images are obtained 5 minutes after radiopharmaeutical administration, with the aim of confirming the side and site of the enlarged PT gland. Intraoperative nuclear mapping using a hand-held gamma probe and quantitative gamma camera counting in the four quadrants is obtained. A 2-3 cm incision is made, and the enlarged PT gland excision is guided by the probe, resulting in a decline in radioactivity in the corresponding quadrant. Intraoperative quick PTH is routinely assayed. When the PTH levels at 10 min fail to fall to less than 50% of the preoperative levels, a multiglandular disease should be suspected and a bilateral neck exploration is usually required. MIP is a safe, cost-effective alternative to bilateral exploration, and should be considered the procedure of choice in patients with primary HPT, when preoperative imaging tests have suggested the presence of a PT adenoma. Radioguided MIP may improve the success rate of surgery in patients with primary hyperparathyroidism. PMID:14971284

Lumachi, F; Iacobone, M; Favia, G

2003-01-01

266

Adaptive optics optical coherence tomography at 120,000 depth scans/s for non-invasive cellular phenotyping of the living human retina  

PubMed Central

This paper presents a successful combination of ultra-high speed (120,000 depth scans/s), ultra-high resolution optical coherence tomography with adaptive optics and an achromatizing lens for compensation of monochromatic and longitudinal chromatic ocular aberrations, respectively, allowing for non-invasive volumetric imaging in normal and pathologic human retinas at cellular resolution. The capability of this imaging system is demonstrated here through preliminary studies by probing cellular intraretinal structures that have not been accessible so far with in vivo, non-invasive, label-free imaging techniques, including pigment epithelial cells, micro-vasculature of the choriocapillaris, single nerve fibre bundles and collagenous plates of the lamina cribrosa in the optic nerve head. In addition, the volumetric extent of cone loss in two colour-blinds could be quantified for the first time. This novel technique provides opportunities to enhance the understanding of retinal pathogenesis and early diagnosis of retinal diseases.

Torti, Cristiano; Povazay, Boris; Hofer, Bernd; Unterhuber, Angelika; Carroll, Joseph; Ahnelt, Peter Kurt; Drexler, Wolfgang

2012-01-01

267

Minimally Invasive Total Knee Replacement  

MedlinePLUS

... that the knee implants be inserted with proper positioning. The bones and ligaments are prepared very carefully ... complications with minimally invasive knee surgery, including poorer positioning of the knee implants. Top of page Research ...

268

Minimally Invasive Aortic Valve Replacement  

MedlinePLUS Videos and Cool Tools

... screen and open the door to informed medical care. Good afternoon and welcome to the Heart Institute ... be progressive and less invasive in how we care for our patients. 8 Here's one from one ...

269

Invasive cervical resorption: treatment challenges  

PubMed Central

Invasive cervical resorption is a relatively uncommon form of external root resorption. It is characterized by invasion of cervical region of the root by fibrovascular tissue derived from the periodontal ligament. This case presents an invasive cervical resorption occurring in maxillary lateral incisor, following damage in cervical cementum from avulsion and intracoronal bleaching procedure. Flap reflection, debridement and restoration with glass ionomer cement were performed in an attempt to repair the defect. But after 2 mon, more resorption extended apically. Considering root stability and recurrence potential, we decided to extract the tooth. Invasive cervical resorption in advanced stages may present great challenges for clinicians. Therefore, prevention and early detection must be stressed when dealing with patients presenting history of potential predisposing factors.

Kim, Yookyung; Lee, Chan-Young; Kim, Euiseong

2012-01-01

270

Plant invasions and extinction debts  

PubMed Central

Whether introduced species invasions pose a major threat to biodiversity is hotly debated. Much of this debate is fueled by recent findings that competition from introduced organisms has driven remarkably few plant species to extinction. Instead, native plant species in invaded ecosystems are often found in refugia: patchy, marginal habitats unsuitable to their nonnative competitors. However, whether the colonization and extinction dynamics of these refugia allow long-term native persistence is uncertain. Of particular concern is the possibility that invasive plants may induce an extinction debt in the native flora, where persistence over the short term masks deterministic extinction trajectories. We examined how invader impacts on landscape structure influence native plant persistence by combining recently developed quantitative techniques for evaluating metapopulation persistence with field measurements of an invaded plant community. We found that European grass invasion of an edaphically heterogeneous California landscape has greatly decreased the likelihood of the persistence of native metapopulations. It does so via two main pathways: (i) decreasing the size of native refugia, which reduces seed production and increases local extinction, and (ii) eroding the dispersal permeability of the matrix between refugia, which reduces their connectivity. Even when native plant extinction is the deterministic outcome of invasion, the time to extinction can be on the order of hundreds of years. We conclude that the relatively short time since invasion in many parts of the world is insufficient to observe the full impact of plant invasions on native biodiversity.

Gilbert, Benjamin; Levine, Jonathan M.

2013-01-01

271

Chapter 7 Parasites and Biological Invasions  

Microsoft Academic Search

There is considerable current interest in the role that parasites can play in biological invasions. This review looks at the fate of parasites during a biological invasion and at their impact on native and invasive hosts, and asks whether parasites can mediate invasion success. An introduced species may lose its parasites as a result of the introduction and such release

Alison M. Dunn

2009-01-01

272

Interstitial guidance of cancer invasion.  

PubMed

Cancer cell invasion into healthy tissues develops preferentially along pre-existing tracks of least resistance, followed by secondary tissue remodelling and destruction. The tissue scaffolds supporting or preventing guidance of invasion vary in structure and molecular composition between organs. In the brain, the guidance is provided by myelinated axons, astrocyte processes, and blood vessels which are used as invasion routes by glioma cells. In the human breast, containing interstitial collagen-rich connective tissue, disseminating breast cancer cells preferentially invade along bundled collagen fibrils and the surface of adipocytes. In both invasion types, physical guidance prompted by interfaces and space is complemented by molecular guidance. Generic mechanisms shared by most, if not all, tissues include (i) guidance by integrins towards fibrillar interstitial collagen and/or laminins and type IV collagen in basement membranes decorating vessels and adipocytes, and, likely, CD44 engaging with hyaluronan; (ii) haptotactic guidance by chemokines and growth factors; and likely (iii) physical pushing mechanisms. Tissue-specific, resticted guidance cues include ECM proteins with restricted expression (tenascins, lecticans), cell-cell interfaces, and newly secreted matrix molecules decorating ECM fibres (laminin-332, thrombospondin-1, osteopontin, periostin). We here review physical and molecular guidance mechanisms in interstitial tissue and brain parenchyma and explore shared principles and organ-specific differences, and their implications for experimental model design and therapeutic targeting of tumour cell invasion. PMID:22006671

Gritsenko, Pavlo G; Ilina, Olga; Friedl, Peter

2012-01-01

273

Utility of bioassays (lettuce, red clover, red fescue, Microtox, MetSTICK, Hyalella, bait lamina) in ecological risk screening of acid metal (Zn) contaminated soil.  

PubMed

The objective of this study was to assess selected bioassays and ecological screening tools for their suitability in a weight of evidence risk screening process of acidic metal contaminated soil. Intact soil cores were used for the tests, which minimizes changes in pH and metal bioavailability that may result from homogenization and drying of the soil. Soil cores were spiked with ZnCl(2) or CaCl(2). Leachate collected from the soil cores was used to account for the exposure pathways through pore water and groundwater. Tests assessed included MetSTICK in soil cores and Microtox in soil leachate, lettuce (Lactuca sativa), red fescue (Festuca rubra) and red clover (Trifolium pratense) in the soil cores and lettuce and red clover in soil leachate, Hyallella azteca in soil leachate, and an ecological soil function test using Bait Lamina in soil cores. Microtox, H. azteca, lettuce and red fescue showed higher sensitivity to low pH than to Zn concentrations and are therefore not recommended as tests on intact acidic soil cores and soil leachate. The Bait Lamina test appeared sensitive to pH levels below 3.7 but should be investigated further as a screening tool in less acidic soils. Among the bioassays, the MetSTICK and the T. pratense bioassays in soil cores were the most sensitive to Zn, with the lowest nominal NOEC of 200 and 400mg Zn/kg d.w., respectively. These bioassays were also tolerant of low pH, which make them suitable for assessing hazards of metal contaminated acid soils. PMID:22444727

Chapman, E Emily V; Hedrei Helmer, Stephanie; Dave, Göran; Murimboh, John D

2012-06-01

274

Non-invasive breast carcinoma.  

PubMed

Non-invasive breast cancer is comprised of two distinct entities: lobular carcinoma in-situ (LCIS) and ductal carcinoma in-situ (DCIS). The natural history of each clinical entity is described and a biologic interpretation of the available data is offered. Lobular carcinoma in-situ is considered only a risk marker rather than a precursor for the subsequent development of invasive cancer, so that once the diagnosis is established, further operative intervention is unnecessary and serial follow-up alone is recommended. The treatment of ductal carcinoma in-situ must take into account that breast-preserving therapy is now considered optimal treatment of invasive cancer of the breast, the disease we are trying to prevent. The pitfalls of recommending treatment based on retrospective data is emphasized and the need to support clinical trials designed to determine the optimal therapeutic management of intraductal carcinoma is affirmed. PMID:1325215

Posner, M C; Wolmark, N

1992-01-01

275

Environmental variability promotes plant invasion.  

PubMed

Global environmental change not only entails changes in mean environmental conditions but also in their variability. Changes in climate variability are often associated with altered disturbance regimes and temporal patterns of resource availability. Here we show that increased variability of soil nutrients strongly promotes another key process of global change, plant invasion. In experimental plant communities, the success of one of the world's most invasive plants, Japanese knotweed, is two- to four-fold increased if extra nutrients are not supplied uniformly, but in a single large pulse, or in multiple pulses of different magnitudes. The superior ability to take advantage of variable environments may be a key mechanism of knotweed dominance, and possibly many other plant invaders. Our study demonstrates that increased nutrient variability can promote plant invasion, and that changes in environmental variability may interact with other global change processes and thereby substantially accelerate ecological change. PMID:23511469

Parepa, Madalin; Fischer, Markus; Bossdorf, Oliver

2013-01-01

276

Approximating spatially exclusive invasion processes  

NASA Astrophysics Data System (ADS)

A number of biological processes, such as invasive plant species and cell migration, are composed of two key mechanisms: motility and reproduction. Due to the spatially exclusive interacting behavior of these processes a cellular automata (CA) model is specified to simulate a one-dimensional invasion process. Three (independence, Poisson, and 2D-Markov chain) approximations are considered that attempt to capture the average behavior of the CA. We show that our 2D-Markov chain approximation accurately predicts the state of the CA for a wide range of motility and reproduction rates.

Ross, Joshua V.; Binder, Benjamin J.

2014-05-01

277

Micafungin in the treatment of invasive candidiasis and invasive aspergillosis  

PubMed Central

Micafungin is an echinocandin antifungal agent available for clinical use in Japan, Europe, and the United States. Through inhibition of ?-1,3-glucan production, an essential component of the fungal cell wall, micafungin exhibits potent antifungal activity against key pathogenic fungi, including Candida and Aspergillus species, while contributing minimal toxicity to mammalian cells. This activity is maintained against polyene and azole-resistant isolates. Pharmacokinetic and pharmacodynamic studies have demonstrated linear kinetics both in adults and children with concentration-dependent activity observed both in vitro and in vivo. Dosage escalation studies have also demonstrated that doses much higher than those currently recommended may be administered without serious adverse effects. Clinically, micafungin has been shown to be efficacious for the treatment of invasive candidiasis and invasive aspergillosis. Furthermore, the clinical effectiveness of micafungin against these infections occurs without the drug interactions that occur with the azoles and the nephrotoxicity observed with amphotericin B formulations. This review will focus on the pharmacology, clinical microbiology, mechanisms of resistance, safety, and clinical efficacy of micafungin in the treatment of invasive candidiasis and invasive aspergillosis.

Wiederhold, Nathan P; Cota, Jason M; Frei, Christopher R

2008-01-01

278

Early Invasive Versus Selectively Invasive Management for Acute Coronary Syndromes  

Microsoft Academic Search

BACKGROUND: Current guidelines recommend an early invasive strategy for patients who have acute coronary syndromes without ST-segment elevation and with an elevated cardiac troponin T level. However, randomized trials have not shown an overall reduction in mortality, and the reduction in the rate of myocardial infarction in previous trials has varied depending on the definition of myocardial infarction. METHODS: We

R. J. de Winter; F. Windhausen; J. H. Cornel; P. Dunselman; C. L. Janus; P. E. Bendermacher; H. R. Michels; G. T. B. Sanders; J. G. P. Tijssen; F. W. A. Verheugt

2005-01-01

279

Trends in invasive fungal infections, with emphasis on invasive aspergillosis  

Microsoft Academic Search

Patterns of invasive fungal infections are changing in many ways. Although yeast infections appear to have reached a stable incidence, the number of infections as a result of Aspergillus species appears to be increasing. Especially for mould infection, the diagnosis remains difficult and the detection and identification of clinically relevant isolates to the species level requires new validated techniques. Diagnostic

Z. Erjavec; H. C. Kluin-Nelemans; P. E. Verweij

2009-01-01

280

Increased Leaf Angle1, a Raf-Like MAPKKK That Interacts with a Nuclear Protein Family, Regulates Mechanical Tissue Formation in the Lamina Joint of Rice[C][W  

PubMed Central

Mitogen-activated protein kinase kinase kinases (MAPKKKs), which function at the top level of mitogen-activated protein kinase cascades, are clustered into three groups. However, no Group C Raf-like MAPKKKs have yet been functionally identified. We report here the characterization of a rice (Oryza sativa) mutant, increased leaf angle1 (ila1), resulting from a T-DNA insertion in a Group C MAPKKK gene. The increased leaf angle in ila1 is caused by abnormal vascular bundle formation and cell wall composition in the leaf lamina joint, as distinct from the mechanism observed in brassinosteroid-related mutants. Phosphorylation assays revealed that ILA1 is a functional kinase with Ser/Thr kinase activity. ILA1 is predominantly resident in the nucleus and expressed in the vascular bundles of leaf lamina joints. Yeast two-hybrid screening identified six closely related ILA1 interacting proteins (IIPs) of unknown function. Using representative IIPs, the interaction of ILA1 and IIPs was confirmed in vivo. IIPs were localized in the nucleus and showed transactivation activity. Furthermore, ILA1 could phosphorylate IIP4, indicating that IIPs may be the downstream substrates of ILA1. Microarray analyses of leaf lamina joints provided additional evidence for alterations in mechanical strength in ila1. ILA1 is thus a key factor regulating mechanical tissue formation at the leaf lamina joint.

Ning, Jing; Zhang, Baocai; Wang, Nili; Zhou, Yihua; Xiong, Lizhong

2011-01-01

281

Minimally invasive saphenous vein harvesting  

Microsoft Academic Search

Background. Minimally invasive techniques to harvest the saphenous vein for coronary artery bypass grafting continue to improve and evolve. Smaller cutaneous incisions have been shown to decrease postoperative discomfort and improve healing. We describe a technique involving carbon dioxide insufflation and endoscopic dissection to allow easier and atraumatic dissection.Methods. The VasoView endoscope system (Origin Medsystems, Inc) was used to harvest

Rohinton J Morris; Michael T Butler; Louis E Samuels

1998-01-01

282

p37 Induces tumor invasiveness.  

PubMed

Previous studies have shown a statistically significant correlation between human carcinomas and monoclonal antibody detection of a Mycoplasma hyorhinis-encoded protein known as p37. A potential mechanism of p37 is that it might promote invasion and metastasis. Recombinant p37 enhanced the invasiveness of two prostate carcinoma and two melanoma cell lines in a dose-dependent manner in vitro, but did not have a significant effect on tumor cell growth. Furthermore, the increased binding to cell surfaces and the enhanced invasive potential of cancer cells from exposure to p37 could be completely reversed by preincubation of the cancer cells with an anti-p37 monoclonal antibody. Sequence comparisons, followed by three-dimensional molecular modeling, revealed a region of similarity between p37 and influenza hemagglutinin A, a sialic acid-binding protein that plays a critical role in viral entry. Binding of p37 to prostate carcinoma cells was found to be at least partially sialic acid dependent because neuraminidase treatment decreased this binding. Taken together, these observations suggest that M. hyorhinis can infect humans and may facilitate tumor invasiveness via p37. These results further suggest that p37 may be a molecular target for cancer therapy. PMID:16020660

Ketcham, Catherine M; Anai, Satoshi; Reutzel, Robbie; Sheng, Shijie; Schuster, Sheldon M; Brenes, Ryan B; Agbandje-McKenna, Mavis; McKenna, Robert; Rosser, Charles J; Boehlein, Susan K

2005-07-01

283

Non-invasive physiological measurements  

SciTech Connect

This book discusses the diagnostic techniques of nondestructive type for monitoring the physiology of various organ systems. The topics covered are: non-invasive assessment of gastric activity; uterine activity, intestinal activity; monitoring of fetal cardiovascular system and bilirubin physiology of infants. Respiratory system of infants is monitored and ultrasonography of heart is discussed.

Rolfe, P.

1983-01-01

284

Establishment Risks for Invasive Species  

Microsoft Academic Search

This article presents a quantitative methodology for evaluating the probability of invasive pest species establishing persistent populations. The estimation of pest establishment relies on data and information describing the biology and ecology of the pest and its interactions with potential host species and the regional environment. This information is developed using a model construct borrowed from theoretical population ecology. The

Steven M. Bartell; Shyam K. Nair

2003-01-01

285

Hybridization increases invasive knotweed success.  

PubMed

Hybridization is one of the fundamental mechanisms by which rapid evolution can occur in exotic species. If hybrids show increased vigour, this could significantly contribute to invasion success. Here, we compared the success of the two invasive knotweeds, Fallopia japonica and F.?sachalinensis, and their hybrid, F.?× bohemica, in competing against experimental communities of native plants. Using plant material from multiple clones of each taxon collected across a latitudinal gradient in Central Europe, we found that knotweed hybrids performed significantly better in competition with a native community and that they more strongly reduced the growth of the native plants. One of the parental species, F.?sachalinensis, regenerated significantly less well from rhizomes, and this difference disappeared if activated carbon was added to the substrate, which suggests allelopathic inhibition of F.?sachalinensis regeneration by native plants. We found substantial within-taxon variation in competitive success in all knotweed taxa, but variation was generally greatest in the hybrid. Interestingly, there was also significant variation within the genetically uniform F.?japonica, possibly reflecting epigenetic differences. Our study shows that invasive knotweed hybrids are indeed more competitive than their parents and that hybridization increased the invasiveness of the exotic knotweed complex. PMID:24665343

Parepa, Madalin; Fischer, Markus; Krebs, Christine; Bossdorf, Oliver

2014-03-01

286

Invasive cranial mycosis our experiences  

PubMed Central

Fungi can cause serious cranial infections in immunocompromised and diabetic patients. Common pathogens mainly include Aspergillus and Mucor. These organisms cause tissue invasion and destruction of adjacent structures (e.g. orbit, ethmoid, sphenoid, maxillary & cavernous sinuses). Mortality and morbidity rate is high despite combined surgical, antifungal and antidiabetic treatment. We present our experience of six cases with such infection.

Kumbhkar, Tapas; Bansal, Shaifali; Jindal, Sushil; Saxena, Vivek; Baghel, Vijay Singh; Kapoor, Anil

2013-01-01

287

Minimally Invasive Management of Urinary Incontinence  

MedlinePLUS

... dolor sit amet, consectetur adipiscing elit. Minimally Invasive Management of Urinary Incontinence Urinary incontinence is a very ... muscle cannot contract effectively. What is minimally invasive management of urinary incontinence? Some of the causes of ...

288

Invasive Tunicates in the Pacific Northwest.  

National Technical Information Service (NTIS)

This guide is intended to enhance the early detection and rapid response (EDRR) of invasive tunicates by providing basic identification of nine of the most invasive tunicates posing a threat to the marine infrastructure, ecology, and economy of the Pacifi...

2014-01-01

289

Invasive rodent eradication on islands.  

PubMed

Invasive mammals are the greatest threat to island biodiversity and invasive rodents are likely responsible for the greatest number of extinctions and ecosystem changes. Techniques for eradicating rodents from islands were developed over 2 decades ago. Since that time there has been a significant development and application of this conservation tool. We reviewed the literature on invasive rodent eradications to assess its current state and identify actions to make it more effective. Worldwide, 332 successful rodent eradications have been undertaken; we identified 35 failed eradications and 20 campaigns of unknown result. Invasive rodents have been eradicated from 284 islands (47,628 ha). With the exception of two small islands, rodenticides were used in all eradication campaigns. Brodifacoum was used in 71% of campaigns and 91% of the total area treated. The most frequent rodenticide distribution methods (from most to least) are bait stations, hand broadcasting, and aerial broadcasting. Nevertheless, campaigns using aerial broadcast made up 76% of the total area treated. Mortality of native vertebrates due to nontarget poisoning has been documented, but affected species quickly recover to pre-eradication population levels or higher. A variety of methods have been developed to mitigate nontarget impacts, and applied research can further aid in minimizing impacts. Land managers should routinely remove invasive rodents from islands <100 ha that lack vertebrates susceptible to nontarget poisoning. For larger islands and those that require nontarget mitigation, expert consultation and greater planning effort are needed. With the exception of house mice (Mus musculus), island size may no longer be the limiting factor for rodent eradications; rather, social acceptance and funding may be the main challenges. To be successful, large-scale rodent campaigns should be integrated with programs to improve the livelihoods of residents, island biosecurity, and reinvasion response programs. PMID:17883491

Howald, Gregg; Donlan, C Josh; Galván, Juan Pablo; Russell, James C; Parkes, John; Samaniego, Araceli; Wang, Yiwei; Veitch, Dick; Genovesi, Piero; Pascal, Michel; Saunders, Alan; Tershy, Bernie

2007-10-01

290

INVASIVE SPECIES MANAGEMENT AND RESEARCH USING GIS  

Microsoft Academic Search

Geographical Information Systems (GIS) are powerful tools in the field of invasive species management. GIS can be used to create potential distribution maps for all manner of taxa, including plants, animals, and diseases. GIS also performs well in the early detection and rapid assessment of invasive species. Here, we used GIS applications to investigate species richness and invasion patterns in

Tracy Holcombe; Thomas J. Stohlgren; Catherine Jarnevich

2007-01-01

291

THE POPULATION BIOLOGY OF INVASIVE SPECIES  

Microsoft Academic Search

? Abstract Contributions from the field of population biology hold promise for understanding and managing invasiveness; invasive species also offer excellent oppor- tunities to study basic processes in population biology. Life history studies and demo- graphic models may be valuable for examining the introduction of invasive species and identifying life history stages where management will be most effective. Evolution- ary

Ann K. Sakai; Fred W. Allendorf; Jodie S. Holt; David M. Lodge; Jane Molofsky; Syndallas Baughman; Robert J. Cabin; Joel E. Cohen; Norman C. Ellstrand; David E. McCauley; Pamela O'Neil; Ingrid M. Parker; John N. Thompson; Stephen G. Weller

2001-01-01

292

The Landscape Ecology of Invasive Spread  

Microsoft Academic Search

Although habitat loss, fragmentation, and invasive species collectively pose the greatest threats to biodiversity, little theoretical or empirical research has addressed the effects of landscape structure—or spa- tial pattern more generally—on the spread of invasive species. Landscape ecology is the study of how spatial pattern affects ecological process. Thus, a landscape ecology of invasive spread involves understanding how spatial pattern,

2002-01-01

293

Biodiversity as a barrier to ecological invasion  

Microsoft Academic Search

Biological invasions are a pervasive and costly environmental problem that has been the focus of intense management and research activities over the past half century. Yet accurate predictions of community susceptibility to invasion remain elusive. The diversity resistance hypothesis, which argues that diverse communities are highly competitive and readily resist invasion, is supported by both theory and experimental studies conducted

Theodore A. Kennedy; Shahid Naeem; Katherine M. Howe; Johannes M. H. Knops; David Tilman; Peter Reich

2002-01-01

294

Cabergoline Treatment in Invasive Giant Prolactinoma  

PubMed Central

Patients with invasive giant prolactinoma suffer from a constellation of symptoms including headache, blurred vision, lethargy, and sexual dysfunction. Cabergoline, a potent dopamine agonist, is a known medication prescribed for the treatment of invasive giant prolactinoma. Here, we report a case of invasive giant prolactinoma in a 52-year-old Saudi male with dramatic response to cabergoline treatment clinically, biochemically, and radiologically.

Alsubaie, Sadeem; Almalki, Mussa H

2014-01-01

295

CONSERVATION PROGRAMS THAT PROMOTE INVASIVE SPECIES  

EPA Science Inventory

Invasive plant species are degrading the structure and function of ecosystems throughout the world. Although most state and federal conservation agencies in the U.S. attempt to reduce the impact of invasive species, some agency activities can contribute to the spread of invasive...

296

Cardiac Output Assessed by Invasive and Minimally Invasive Techniques  

PubMed Central

Cardiac output (CO) measurement has long been considered essential to the assessment and guidance of therapeutic decisions in critically ill patients and for patients undergoing certain high-risk surgeries. Despite controversies, complications and inherent errors in measurement, pulmonary artery catheter (PAC) continuous and intermittent bolus techniques of CO measurement continue to be the gold standard. Newer techniques provide less invasive alternatives; however, currently available monitors are unable to provide central circulation pressures or true mixed venous saturations. Esophageal Doppler and pulse contour monitors can predict fluid responsiveness and have been shown to decrease postoperative morbidity. Many minimally invasive techniques continue to suffer from decreased accuracy and reliability under periods of hemodynamic instability, and so few have reached the level of interchangeability with the PAC.

Lee, Allison J.; Cohn, Jennifer Hochman; Ranasinghe, J. Sudharma

2011-01-01

297

Minimally Invasive Video-Assisted versus Minimally Invasive Nonendoscopic Thyroidectomy  

PubMed Central

Minimally invasive video-assisted thyroidectomy (MIVAT) and minimally invasive nonendoscopic thyroidectomy (MINET) represent well accepted and reproducible techniques developed with the main goal to improve cosmetic outcome, accelerate healing, and increase patient's comfort following thyroid surgery. Between 2007 and 2011, a prospective nonrandomized study of patients undergoing minimally invasive thyroid surgery was performed to compare advantages and disadvantages of the two different techniques. There were no significant differences in the length of incision to perform surgical procedures. Mean duration of hemithyroidectomy was comparable in both groups, but it was more time consuming to perform total thyroidectomy by MIVAT. There were more patients undergoing MIVAT procedures without active drainage in the postoperative course and we also could see a trend for less pain in the same group. This was paralleled by statistically significant decreased administration of both opiates and nonopiate analgesics. We encountered two cases of recurrent laryngeal nerve palsies in the MIVAT group only. MIVAT and MINET represent safe and feasible alternative to conventional thyroid surgery in selected cases and this prospective study has shown minimal differences between these two techniques.

Fik, Zdenek; Astl, Jaromir; Zabrodsky, Michal; Lukes, Petr; Merunka, Ilja; Chovanec, Martin

2014-01-01

298

Invasive cervical resorption following trauma.  

PubMed

Invasive cervical resorption is an insidious and often aggressively destructive form of external root resorption which may occur as a late complication following dental trauma particularly where it involves damage to cementum and supporting tissues. While this resorption may be evident clinically as a pink coronal discolouration, later with cavitation of the enamel, often there are no obvious external signs and the condition is only detected radiographically. It is characterised by the invasion of the cervical region of the root by fibrovascular tissue which progressively resorbs dentine, enamel and cementum. The dental pulp remains protected by an intact layer of dentine and predentine until late in the process. Ectopic calcifications can be observed in advanced lesions both within the invading fibrous tissue and deposited directly onto the resorbed dentine surface. The aetiology of invasive cervical resorption is unknown but trauma has been documented as a potential predisposing factor. A recent study by the author of 222 patients with a total of 257 teeth which displayed varying degrees of invasive cervical resorption showed that trauma alone was a potential predisposing sole factor in 14% of patients and 15.1% of teeth. Trauma in combination with bleaching, orthodontics or delayed eruption was found in an additional 11.2% of patients or 10.6% of teeth and of these a combination of trauma and bleaching occurred in a relatively high proportion of 7.7% of patients or 7.4% of teeth. This study also revealed that of other potential predisposing factors orthodontics was the most common sole factor constituting 21.2% of patients and 24.1% of teeth examined. Successful treatment of invasive cervical resorption is dependent on the extent of the resorptive process. Teeth with invasive cervical resorption have been divided into four classes. Whilst several treatment modalities are possible, a clinical evaluation of the treatment of this condition by the topical application of a 90% aqueous solution of trichloracetic acid, curettage, endodontic therapy where necessary and restoration with a glass ionomer cement has been evaluated on 94 patients with a total of 101 teeth with a minimum follow-up period of three years. Results indicate a satisfactory treatment outcome can be anticipated in Class 1, 2 and 3 cases. In Class 4 resorption no treatment or alternative therapy is recommended. Diagnosis of lesions at an early stage of development is highly desirable and therefore the patients who have a potential for the development of this condition by virtue of a history such as trauma should be monitored radiographically at intervals throughout life. PMID:11411085

Heithersay, G S

1999-08-01

299

[Invasive emergency techniques--cricothyroidotomy].  

PubMed

On-scene invasive emergency procedures, such as cricothyroidotomy, chest drain, intraosseous puncture or even on-field-amputation, are often unavoidable, when indicated, and present a major challenge for the emergency physician. Personal, temporal or local conditions are often unsuitable. Even with regular intervention by the emergency medical service, "last resort" measures occur very infrequently, particularly in relation to paediatric emergencies. As well as theoretical training, practice-oriented course concepts are essential in order to achieve high quality in these procedures. This article presents the use of cricothyroidotomy on adults and children, with reference to indication, implementation, problems and risks. It is part of a series of four articles on the subject of invasive emergency techniques. PMID:24792594

Hess, Thorsten; Stuhr, Markus; Knacke, Peer-Gunnar; Reifferscheid, Florian; Kerner, Thoralf

2014-04-01

300

Porphyromonas gingivalis invasion of gingival epithelial cells.  

PubMed Central

Porphyromonas gingivalis, a periodontal pathogen, can invade primary cultures of gingival epithelial cells. Optimal invasion occurred at a relatively low multiplicity of infection (i.e., 100) and demonstrated saturation at a higher multiplicity of infection. Following the lag phase, during which bacteria invaded poorly, invasion was independent of growth phase. P. gingivalis was capable of replicating within the epithelial cells. Invasion was an active process requiring both bacterial and epithelial cell energy production. Invasion was sensitive to inhibitors of microfilaments and microtubules, demonstrating that epithelial cell cytoskeletal rearrangements are involved in bacterial entry. P. gingivalis, but not epithelial cell, protein synthesis was necessary for invasion. Invasion within the epithelial cells was not blocked by inhibitors of protein kinase activity. Invasion was inhibited by protease inhibitors, suggesting that P. gingivalis proteases may be involved in the invasion process. Low-passage clinical isolates of P. gingivalis invaded with higher efficiency than the type strain. Serum inhibited invasion of the type strain but had no effect on the invasion of a clinical isolate. Invasion of gingival epithelial cells by P. gingivalis may contribute to the pathology of periodontal diseases.

Lamont, R J; Chan, A; Belton, C M; Izutsu, K T; Vasel, D; Weinberg, A

1995-01-01

301

Rapidly progressing extracanal invasive resorption.  

PubMed

Frank and Bakland coined the term "Extracanal invasive resorption" (EIR) to identify a resorptive entity that has been variously classified. This external resorption originates in the cementum adjacent to the periodontal ligament. The lesion is believed to be a response to injury and irritation of the periodontal ligament, or to pressure from ectopic eruption, orthodontic pressure, intracoronal bleaching, periodontal treatment, or an unknown idiopathic cause. PMID:9171481

Mock, E S; Wolff, G K; Galvan, D A

1997-01-01

302

On the notion of (medical) invasiveness.  

PubMed

The relation between the notions of (medical) invasiveness and (actual or potential) harm has not been systematically discussed nor theoretically grounded, despite its importance to clinical-ethical practice. This paper aims to clarify the notion of invasiveness beyond the traditional notion of invasiveness as breaking skin or inserting mechanical objects into the body. The traditional notion of invasiveness is challenged by counterexamples. Three approaches to the notion of disorder applied here are: deviation from what is common; deviation from what is considered ideal; and disruption of self-organization. Assuming that more extreme measures are related to more harm, all three approaches to the notion of disorder suggest that invasiveness is proportional if not identical to harm, and show no clear relation to the traditional notion of invasiveness. In conclusion, the notion of invasiveness may best be eliminated from medical terminology, replacing it with a detailed understanding of the notion of harm. PMID:20390453

Rudnick, Abraham

2011-06-01

303

Will climate change promote future invasions?  

PubMed Central

Biological invasion is increasingly recognized as one of the greatest threats to biodiversity. Using ensemble forecasts from species distribution models to project future suitable areas of the “100 of the world’s worst invasive species” defined by the IUCN, we show that both climate and land use changes will likely cause drastic species range shifts. Looking at potential spatial aggregation of invasive species, we identify three future hotspots of invasion in Europe, northeastern North America, and Oceania. We also emphasize that some regions could lose a significant number of invasive alien species, creating opportunities for ecosystem restoration. From the list of 100, scenarios of potential range distributions show a consistent shrinking for invasive amphibians and birds, while for aquatic and terrestrial invertebrates distributions are projected to substantially increase in most cases. Given the harmful impacts these invasive species currently have on ecosystems, these species will likely dramatically influence the future of biodiversity.

Bellard, C.; Thuiller, W.; Leroy, B.; Genovesi, P.; Bakkenes, M.; Courchamp, F.

2013-01-01

304

Reversing invasion in bistable systems.  

PubMed

In this paper, we discuss a class of bistable reaction-diffusion systems used to model the competitive interaction of two species. The interactions are assumed to be of classic "Lotka-Volterra" type and we will consider a particular problem with relevance to applications in population dynamics: essentially, we study under what conditions the interplay of relative motility (diffusion) and competitive strength can cause waves of invasion to be halted and reversed. By establishing rigorous results concerning related degenerate and near-degenerate systems, we build a picture of the dependence of the wave speed on system parameters. Our results lead us to conjecture that this class of competition model has three "zones of response". In the central zone, varying the motility can slow, halt and reverse invasion. However, in the two outer zones, the direction of invasion is independent of the relative motility and is entirely determined by the relative competitive strengths. Furthermore, we conjecture that for a large class of competition models of the type studied here, the wave speed is an increasing function of the relative motility. PMID:22086366

Alzahrani, Ebraheem O; Davidson, Fordyce A; Dodds, Niall

2012-12-01

305

Serotonin potentiation of glycine-activated whole-cell currents in the superficial laminae neurons of the rat spinal dorsal horn is mediated by protein kinase C.  

PubMed

The modulatory effects of serotonin (5-HT) on glycine (Gly)-activated whole-cell currents were investigated in neurons acutely dissociated from the superficial laminae (I and II) of the rat spinal dorsal horn using the nystatin-perforated patch recording configuration under voltage-clamp conditions. Our results demonstrate that (1). Gly acted on strychnine (STR)-sensitive Gly receptors and elicited inward Cl(-) currents (I(Gly)) at a holding potential of -40 mV; (2). 5-HT potentiated I(Gly) without affecting the reversal potential of I(Gly); (3). the agonist (alpha-methyl-5-HT) and antagonist (ketanserine) of 5-HT(2) receptor mimicked and blocked the potentiating effect of 5-HT on I(Gly), respectively; (4). bisindolylmaleimide I (BIM), a selective inhibitor of protein kinase C (PKC), reduced the potentiating effect of 5-HT on I(Gly); and (5). 5-HT-induced enhancement of I(Gly) was not affected by pretreatment with 1,2-bis-(2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid tetrakis (acetoxy-methyl) ester (BAPTA AM), a Ca(2+) chelator. These results indicate that (1). the potentiation of 5-HT on I(Gly) is mediated by 5-HT(2) receptor and through Ca(2+)-independent PKC intracellular signal transduction pathway; and (2). the interactions between 5-HT and Gly might modulate the transmission of nociceptive information through the spinal cord. PMID:12372564

Li, Hui; Kang, Jie-Fang; Li, Yun-Qing

2002-09-30

306

Identification of Two Brassinosteroids from the Cambial Region of Scots Pine (Pinus silverstris) by Gas Chromatography-Mass Spectrometry, after Detection Using a Dwarf Rice Lamina Inclination Bioassay.  

PubMed

A simple and improved dwarf rice (Oryza sativa var Tan-ginbozu) lamina inclination bioassay for brassinosteroids (BRs) was developed based on a previously published method (K Takeno, RP Pharis [1982] Plant Cell Physiol 23: 1275-1281). The assay used 3-day-old intact seedlings, and detection of BR was made more sensitive by synergizing the response to BR with indole-3-acetic acid (IAA). The minimum detectable amount of BR was less than 0.1 nanogram/rice plant (brassinolide equivalents). Purification steps for isolation of BR from tissue scrapings taken from the cambial region of Scots pine (Pinus silverstris) harvested during the period of rapid wood production were guided by this assay. After column chromatography (silica gel and PrepPak C(18)) and reversed phase C(18) high performance liquid chromatography, the biologically active fractions were analyzed by gas chromatography-mass spectrometry (GC-MS) and/or GC-MS-selected ion monitoring. Two BRs, castasterone (major) and brassinolide (minor) were identified. This is the first identification of BR from the cambial region of a conifer. PMID:16667906

Kim, S K; Abe, H; Little, C H; Pharis, R P

1990-12-01

307

A study of the damage tolerance enhancement of carbon/epoxy laminates by utilizing an outer lamina of ultra high molecular weight polyethylene  

NASA Technical Reports Server (NTRS)

The damage tolerance of carbon/epoxy was examined when an outer layer of ultra high molecular weight polyethylene (Spectra) material was utilized on the specimen. Four types of 16 ply quasi-isotropic panels, (0,+45,90,-45)s2 were tested. The first contained no Spectra, while the others had one lamina of Spectra placed on either the top (impacted side), bottom or both surfaces of the composite plate. A range of impact energies up to approximately 8.5 Joules (6.3 ft-lbs) was used to inflict damage upon these specimens. Glass/Phenolic honeycomb beams with a core density of 314 N/m3 (2.0 lb/ft3) and 8 ply quasi-isotropic facesheets were also tested for compression-after-impact strength with and without Spectra at impact energies of 1,2,3 and 4 Joules (.74, 1.47, 2.21 and 2.95 ft-lbs). It was observed that the composite plates had little change in damage tolerance due to the Spectra, while the honeycomb panels demonstrated a slight increase in damage tolerance when Spectra was added, the damage tolerance level being more improved at higher impact energies.

Nettles, Alan T.; Lance, David G.

1991-01-01

308

Influence of lamina terminalis fenestration on the occurrence of the shunt-dependent hydrocephalus in anterior communicating artery aneurysmal subarachnoid hemorrhage.  

PubMed

Recently, it was reported that fenestration of the lamina terminalis (LT) may reduce the incidence of shunt-dependent hydrocephalus in aneurysmal subarachnoid hemorrhage (SAH). The authors investigated the efficacy of the LT opening on the incidence of shunt-dependent hydrocephalus in the ruptured anterior communicating artery (ACoA) aneurysms. The data of 71-ruptured ACoA aneurysm patients who underwent aneurysmal clipping in acute stage were reviewed retrospectively. Group I (n=36) included the patients with microsurgical fenestration of LT during surgery, Group II (n=35) consisted of patients in whom fenestration of LT was not feasible. The rate of shunt-dependent hydrocephalus was compared between two groups by logistic regression to control for confounding factors. Ventriculo-peritoneal shunts were performed after aneurysmal obliteration in 18 patients (25.4%). The conversion rates from acute hydrocephalus on admission to chronic hydrocephalus in each group were 29.6% (Group I) and 58.8% (Group II), respectively. However, there was no significant correlation between the microsurgical fenestration and the rate of occurrence of shunt-dependent hydrocephalus (p>0.05). Surgeons should carefully decide the concomitant use of LT fenestration during surgery for the ruptured ACoA aneurysms because of the microsurgical fenestration of LT can play a negative role in reducing the incidence of chronic hydrocephalus. PMID:16479076

Kim, Jae Min; Jeon, Ji Young; Kim, Jae Hoon; Cheong, Jin Hwan; Bak, Koang Hum; Kim, Choong Hyun; Yi, Hyeong Joong; Kim, Kwang Myung

2006-02-01

309

Influence of Lamina Terminalis Fenestration on the Occurrence of the Shunt-Dependent Hydrocephalus in Anterior Communicating Artery Aneurysmal Subarachnoid Hemorrhage  

PubMed Central

Recently, it was reported that fenestration of the lamina terminalis (LT) may reduce the incidence of shunt-dependent hydrocephalus in aneurysmal subarachnoid hemorrhage (SAH). The authors investigated the efficacy of the LT opening on the incidence of shunt-dependent hydrocephalus in the ruptured anterior communicating artery (ACoA) aneurysms. The data of 71-ruptured ACoA aneurysm patients who underwent aneurysmal clipping in acute stage were reviewed retrospectively. Group I (n=36) included the patients with microsurgical fenestration of LT during surgery, Group II (n=35) consisted of patients in whom fenestration of LT was not feasible. The rate of shunt-dependent hydrocephalus was compared between two groups by logistic regression to control for confounding factors. Ventriculo-peritoneal shunts were performed after aneurysmal obliteration in 18 patients (25.4%). The conversion rates from acute hydrocephalus on admission to chronic hydrocephalus in each group were 29.6% (Group I) and 58.8% (Group II), respectively. However, there was no significant correlation between the microsurgical fenestration and the rate of occurrence of shunt-dependent hydrocephalus (p>0.05). Surgeons should carefully decide the concomitant use of LT fenestration during surgery for the ruptured ACoA aneurysms because of the microsurgical fenestration of LT can play a negative role in reducing the incidence of chronic hydrocephalus.

Jeon, Ji Young; Kim, Jae Hoon; Cheong, Jin Hwan; Bak, Koang Hum; Kim, Choong Hyun; Yi, Hyeong Joong; Kim, Kwang Myung

2006-01-01

310

Invadopodia are essential in transurothelial invasion during the muscle invasion of bladder cancer cells.  

PubMed

Muscle invasive bladder cancer is an aggressive type of epithelial tumor with a high rate of metastasis. For bladder cancer cells to reach the muscle layer, cells must invade through an urothelial cell monolayer (transurothelial invasion) and basement membrane. However, the process by which transurothelial invasion occurs has not been fully characterized. In this study we developed a novel method to evaluate the transurothelial invasion capacity and investigated its cellular and molecular processes using primary culture cells from bladder cancer patients. The analysis revealed that compared with the prognosis for patients with non?muscle invasive bladder cancer that of patients with muscle invasive bladder cancer was particularly poor due to metastatic recurrence. Cancer cells from patients with muscle invasive bladder cancer exhibited a higher invasive capacity through the urothelial cell monolayer compared with those from non?invasive bladder cancer patients. Furthermore, muscle invasive bladder cancer cells demonstrated a greater ability to form invadopodia, the filamentous actin?based membrane protrusions required for matrix degradation and invasion compared with non?invasive cells. Bladder cancer cell lines were established with reduced invadopodia formation by silencing the expression of cortactin, an essential component of invadopodia. The cortactin knockdown bladder cancer cells with reduced invadopodia formation demonstrated a markedly reduced ability to invade through the urothelial cell monolayer, indicating that invadopodia are essential for transurothelial invasion. The results indicate that invadopodia formation is required for muscle invasion of aggressive bladder cancer cells. PMID:24699942

Imanishi, Kengo; Yoneyama, Mihoko Sutoh; Hatakeyama, Shingo; Yamamoto, Hayato; Koie, Takuya; Saitoh, Hisao; Yamaya, Kanemitsu; Funyu, Tomihisa; Nakamura, Toshiya; Ohyama, Chikara; Tsuboi, Shigeru

2014-06-01

311

Alien Invasion: Invasive Species (title provided or enhanced by cataloger)  

NSDL National Science Digital Library

Using the example of the Eastern United States continental shelf, this lesson helps students understand how alien species enter non-native habitats, what problems are associated with these species, and what can be done about them. Students will be able to compare and contrast "alien species" and "invasive species," explain positive and negative impacts associated with the introduction of non-native species, and give a specific example of species that produces these impacts. They will also describe at least three ways in which species may be introduced into non-native environments and discuss actions that can be taken to mitigate negative impacts caused by non-native species.

312

NCEP Exercise-Invasive Species and Mechanisms of Invasions  

NSDL National Science Digital Library

In this exercise students gain hands on experience by conducting observations in the field. In groups students identify and record all the plants found in a sample plot. Using pooled data from the entire class students evaluate the effect of the presence of invasive species on their local ecosystem. Additional teaching materials on topics relating to biodiversity conservation and ecology can be obtained free of charge by registering at the Network for Conservation Educators and PractitionersÃÂ website (http://ncep.amnh.org).

Finlayson, C.

2010-02-16

313

The Invasive Species Forecasting System  

NASA Technical Reports Server (NTRS)

The Invasive Species Forecasting System (ISFS) provides computational support for the generic work processes found in many regional-scale ecosystem modeling applications. Decision support tools built using ISFS allow a user to load point occurrence field sample data for a plant species of interest and quickly generate habitat suitability maps for geographic regions of management concern, such as a national park, monument, forest, or refuge. This type of decision product helps resource managers plan invasive species protection, monitoring, and control strategies for the lands they manage. Until now, scientists and resource managers have lacked the data-assembly and computing capabilities to produce these maps quickly and cost efficiently. ISFS focuses on regional-scale habitat suitability modeling for invasive terrestrial plants. ISFS s component architecture emphasizes simplicity and adaptability. Its core services can be easily adapted to produce model-based decision support tools tailored to particular parks, monuments, forests, refuges, and related management units. ISFS can be used to build standalone run-time tools that require no connection to the Internet, as well as fully Internet-based decision support applications. ISFS provides the core data structures, operating system interfaces, network interfaces, and inter-component constraints comprising the canonical workflow for habitat suitability modeling. The predictors, analysis methods, and geographic extents involved in any particular model run are elements of the user space and arbitrarily configurable by the user. ISFS provides small, lightweight, readily hardened core components of general utility. These components can be adapted to unanticipated uses, are tailorable, and require at most a loosely coupled, nonproprietary connection to the Web. Users can invoke capabilities from a command line; programmers can integrate ISFS's core components into more complex systems and services. Taken together, these features enable a degree of decentralization and distributed ownership that have helped other types of scientific information services succeed in recent years.

Schnase, John; Most, Neal; Gill, Roger; Ma, Peter

2011-01-01

314

Antarctic Crabs: Invasion or Endurance?  

PubMed Central

Recent scientific interest following the “discovery” of lithodid crabs around Antarctica has centred on a hypothesis that these crabs might be poised to invade the Antarctic shelf if the recent warming trend continues, potentially decimating its native fauna. This “invasion hypothesis” suggests that decapod crabs were driven out of Antarctica 40–15 million years ago and are only now returning as “warm” enough habitats become available. The hypothesis is based on a geographically and spatially poor fossil record of a different group of crabs (Brachyura), and examination of relatively few Recent lithodid samples from the Antarctic slope. In this paper, we examine the existing lithodid fossil record and present the distribution and biogeographic patterns derived from over 16,000 records of Recent Southern Hemisphere crabs and lobsters. Globally, the lithodid fossil record consists of only two known specimens, neither of which comes from the Antarctic. Recent records show that 22 species of crabs and lobsters have been reported from the Southern Ocean, with 12 species found south of 60°S. All are restricted to waters warmer than 0°C, with their Antarctic distribution limited to the areas of seafloor dominated by Circumpolar Deep Water (CDW). Currently, CDW extends further and shallower onto the West Antarctic shelf than the known distribution ranges of most lithodid species examined. Geological evidence suggests that West Antarctic shelf could have been available for colonisation during the last 9,000 years. Distribution patterns, species richness, and levels of endemism all suggest that, rather than becoming extinct and recently re-invading from outside Antarctica, the lithodid crabs have likely persisted, and even radiated, on or near to Antarctic slope. We conclude there is no evidence for a modern-day “crab invasion”. We recommend a repeated targeted lithodid sampling program along the West Antarctic shelf to fully test the validity of the “invasion hypothesis”.

Griffiths, Huw J.; Whittle, Rowan J.; Roberts, Stephen J.; Belchier, Mark; Linse, Katrin

2013-01-01

315

Origin and hierarchy of basal lamina-forming and -non-forming myogenic cells in mouse skeletal muscle in relation to adhesive capacity and Pax7 expression in vitro  

Microsoft Academic Search

As a novel approach to distinguish skeletal myogenic cell populations, basal lamina (BL) formation of myogenic cells was examined\\u000a in the mouse compensatory enlarged plantaris muscles in vivo and in fiber-bundle cultures in vitro. MyoD+ myogenic cells located inside the regenerative muscle fiber BL were laminin? but interstitial MyoD+ cells were laminin+. This was also confirmed by electron microscopy as

Tetsuro Tamaki; Kayoko Tono; Yoshiyasu Uchiyama; Yoshinori Okada; Maki Masuda; Shuichi Soeda; Masahiro Nitta; Akira Akatsuka

2011-01-01

316

Minimally invasive surgery for oesophageal cancer.  

PubMed

Worldwide an increasing part of oncologic oesophagectomies is performed in a minimally invasive way. Over the past decades multiple reports have addressed the perioperative outcomes and oncologic safety of minimally invasive oesophageal surgery. Although many of these (retrospective) case-control studies identified minimally invasive oesophagectomy as a safe alternative to open techniques, the clear benefit remained subject to debate. Recently, this controversy has partially resolved due to the results of the first randomized controlled trial that compared both techniques. In this trial short-term benefits of minimally invasive oesophagectomy were demonstrated in terms of lower incidence of pulmonary infections, shorter hospital stay and better postoperative quality of life. However, the current lack of long-term data on recurrence rate and overall survival precludes a comprehensive comparison of minimally invasive and open oesophagectomy. Proclaiming minimally invasive oesophagectomy as the standard of care for patients with resectable oesophageal cancer would therefore be a premature decision. PMID:24485254

Anderegg, Maarten C J; Gisbertz, Suzanne S; van Berge Henegouwen, Mark I

2014-02-01

317

Minimally invasive donor nephrectomy: innovations.  

PubMed

From open surgery to laparoscopic surgery, there has been an evolution in the surgical technique for live donor nephrectomy which goes beyond patient comfort. As a unique operation where the margin for error is nearly nil, and where the patient is essentially harmed for an altruistic goal, ensuring the best possible result is vital. Additionally, as the morbidity of the operation decreases, there is a theoretical increase in the donor pool. In this review, the latest techniques for minimally invasive live donor nephrectomy are covered, including new approaches such as laparoendoscopic single-site surgery, natural orifice surgery, and new tools such as robotics. PMID:24338815

Caso, Jorge R

2014-01-01

318

Components of the basal lamina and dystrophin-dystroglycan complex in the neurointermediate lobe of rat pituitary gland: different localizations of beta-dystroglycan, dystrobrevins, alpha1-syntrophin, and aquaporin-4.  

PubMed

The so-called neurointermediate lobe is composed of the intermediate and neural lobes of the pituitary. The present immunohistochemical study investigated components of the basal lamina (laminin, agrin, and perlecan), the dystrophin-dystroglycan complex (dystrophin, beta-dystroglycan, alpha1-dystrobrevin, beta-dystrobrevin, utrophin, and alpha1-syntrophin), and the aquaporins (aquaporin-4 and -9). Glia markers (GFAP, S100, and glutamine synthetase) and components of connective tissue (collagen type I and fibronectin) were also labeled. In the neurohypophysis, immunostaining of basal lamina delineated meningeal invaginations. In these invaginations, vessels were seen to penetrate the organ without submerging into its parenchyma. On the parenchymal side of the invaginations, beta-dystroglycan was detected, whereas utrophin was detected in the walls of vessels. Immunostaining of alpha1-dystrobrevin and alpha1-syntrophin did not delineate the vessels. The cells of the intermediate lobe were fully immunoreactive to alpha1-dystrobrevin and alpha1-syntrophin, whereas components of the basal lamina delineated the contours of the cells. GFAP-immunoreactive processes surrounded them. Aquaporin-4 localized at the periphery of the neurohypophysis, mainly adjacent to the intermediate lobe but not along the vessels. It colocalized only partially with GFAP and not at all with alpha1-syntrophin. Aquaporin-9 was not detected. These results emphasize the possibility that the components of the dystrophin-dystroglycan complex localize differently and raise the question about the roles of dystrobrevins, alpha1-syntrophin, and aquaporin-4 in the functions of the intermediate and neural lobes, respectively. PMID:20124096

Pócsai, Károly; Bagyura, Zsolt; Kálmán, Mihály

2010-05-01

319

Impacts of Invasive Species on Ecosystem Services  

Microsoft Academic Search

The impacts of invasive species on ecosystem services have attracted worldwide attention. Despite the overwhelming evidence\\u000a of these impacts and a growing appreciation for ecosystem services, however, researchers and policymakers rarely directly\\u000a address the connection between invasions and ecosystem services.Various attempts have been made to address the ecosystem processes\\u000a that are affected by invasive species (e.g., Levine et al. 2003;

Heather Charles; Jeffrey S. Dukes

320

Invasive aliens on tropical East Asian islands  

Microsoft Academic Search

Tropical East Asia (TEA) has numerous islands, both continental and oceanic. This study uses information on invasive aliens\\u000a in terrestrial habitats on these islands to test the generality of the continental-oceanic contrast in invasibility, assess\\u000a the conservation impacts of invasive species, and suggest ways to mitigate these. The continental islands of Hong Kong and\\u000a Singapore are worst-case scenarios for continental

Richard T. Corlett

2010-01-01

321

Immobilizing nitrogen to control plant invasion  

Microsoft Academic Search

Increased soil N availability may often facilitate plant invasions. Therefore, lowering N availability might reduce these\\u000a invasions and favor desired species. Here, we review the potential efficacy of several commonly proposed management approaches\\u000a for lowering N availability to control invasion, including soil C addition, burning, grazing, topsoil removal, and biomass\\u000a removal, as well as a less frequently proposed management approach

Laura G. Perry; Dana M. Blumenthal; Thomas A. Monaco; Mark W. Paschke; Edward F. Redente

2010-01-01

322

Cabergoline treatment in invasive giant prolactinoma.  

PubMed

Patients with invasive giant prolactinoma suffer from a constellation of symptoms including headache, blurred vision, lethargy, and sexual dysfunction. Cabergoline, a potent dopamine agonist, is a known medication prescribed for the treatment of invasive giant prolactinoma. Here, we report a case of invasive giant prolactinoma in a 52-year-old Saudi male with dramatic response to cabergoline treatment clinically, biochemically, and radiologically. PMID:25002819

Alsubaie, Sadeem; Almalki, Mussa H

2014-01-01

323

[Malignant polyps of the colon and rectum].  

PubMed

It is important for the general surgeon to have a clear idea of what is a malignant polyp and factors determining its clinical management. A malignant polyp is either sessile or pedunculated and harbors an invasive carcinoma which means that malignant cells have penetrated into or through the muscularis mucosae. Carcinoma in situ, intramucosal carcinoma, superficial carcinoma, carcinoma within the the mucosa or lamina propria are terms commonly used that must be distinguished from true invasive malignancy. These polyps should be treated by complete polypectomy and followed up as in a benign polyp. A polyp with invasive carcinoma requires careful evaluation to make a decision if simple polypectomy is sufficient treatment or whether surgical treatment is indicated. This decision is based on the risk factors such as a residual/recurrent tumour and the risk of lymph node metastases. We present a current review of the literature on the subject. PMID:11037703

Bém, J; Jedlicka, J; Bém, S

2000-07-01

324

Collagen IV alpha 3, alpha 4, and alpha 5 chains in rodent basal laminae: sequence, distribution, association with laminins, and developmental switches  

PubMed Central

Collagen IV is a major component of vertebrate basal laminae (BLs). Studies in humans have revealed a family of genes encoding alpha 1- alpha 6 collagen IV chains and implicated alpha 3-alpha 6 in disease processes (Goodpasture and Alport syndromes and diffuse leiomyomatosis). To extend studies of these components to an experimentally accessible animal, we cloned cDNAs encoding partial collagen alpha 3, alpha 4, and alpha 5(IV) chains from the mouse. Ribonuclease protection assays showed that all three genes were expressed at highest levels in kidney and lung; alpha 5(IV) was also expressed at high levels in heart. We then made antibodies specific for each collagen IV chain. Immunohistochemical studies of several tissues revealed many combinations of collagen IV chains; however, alpha 3 and alpha 4 (IV) were always coexpressed, and only appeared in BLs that were alpha 5(IV) positive. The alpha 3-alpha 5(IV) chains were frequently but not exclusively associated with the S (beta 2) chain of laminin, as were the alpha 1, 2 (IV) collagen chains with laminin B1 (beta 1). An analysis of developing rat kidney BLs showed that newly formed (S-shaped) nephrons harbored collagen alpha 1 and alpha 2(IV) and laminin B1; maturing (capillary loop stage) BLs contained collagen alpha 1-alpha 5(IV) and laminin B1 and S-laminin; and mature glomerular BLs contained mainly collagen alpha 3-alpha 5(IV) and S-laminin. Thus, collagen alpha 1 and alpha 2(IV) and laminin B1 appear to be fetal components of the glomerular BL, and there is a developmental switch to collagen alpha 3-alpha 5(IV) and S-laminin expression.

1994-01-01

325

Pleiotropic phenotypes of the salt-tolerant and cytosine hypomethylated leafless inflorescence, evergreen dwarf and irregular leaf lamina mutants of Catharanthus roseus possessing Mendelian inheritance.  

PubMed

In Catharanthus roseus, three morphological cum salt-tolerant chemically induced mutants of Mendelian inheritance and their wild-type parent cv Nirmal were characterized for overall cytosine methylation at DNA repeats, expression of 119 protein coding and seven miRNA-coding genes and 50 quantitative traits. The mutants, named after their principal morphological feature(s), were leafless inflorescence (lli), evergreen dwarf (egd) and irregular leaf lamina (ill). The Southern-blot analysis of MspI digested DNAs of mutants probed with centromeric and 5S and 18S rDNA probes indicated that, in comparison to wild type, the mutants were extensively demethylated at cytosine sites. Among the 126 genes investigated for transcriptional expression, 85 were upregulated and 41 were downregulated in mutants. All of the five genes known to be stress responsive had increased expression in mutants. Several miRNA genes showed either increased or decreased expression in mutants. The C. roseus counterparts of CMT3, DRM2 and RDR2 were downregulated in mutants. Among the cell, organ and plant size, photosynthesis and metabolism related traits studied, 28 traits were similarly affected in mutants as compared to wild type. Each of the mutants also expressed some traits distinctively. The egd mutant possessed superior photosynthesis and water retention abilities. Biomass was hyperaccumulated in roots, stems, leaves and seeds of the lli mutant. The ill mutant was richest in the pharmaceutical alkaloids catharanthine, vindoline, vincristine and vinblastine. The nature of mutations, origins of mutant phenotypes and evolutionary importance of these mutants are discussed. PMID:24371160

Kumari, Renu; Sharma, Vishakha; Sharma, Vinay; Kumar, Sushil

2013-12-01

326

Fine-scale study of a thick stratospheric ozone lamina at the edge of the southern subtropical barrier: 2. Numerical simulations with coupled dynamics models  

NASA Astrophysics Data System (ADS)

The modeling of an event such as an ozone lamina requires reproducing both the global and the small scales. In this study we report on a specific model capable of resolving such scale issues: the COMMID model, which has been developed by coupling a mechanistic model, MSDOL, with a high-resolution advection model, MIMOSA. MSDOL, which is forced toward National Centers for Environmental Prediction (NCEP) reanalyses below 100 hPa, provides a consistent picture of the stratospheric large-scale circulation from which MIMOSA simulates the fine-scale filaments generated by breaking planetary waves in the stratosphere. To evaluate the performances of the model, we present results for a particular event of tropical-air intrusion at midlatitudes across the southern subtropical barrier observed in July 2000 and described in part 1 (Portafaix et al., 2003). The model is used to examine the contribution of each wave to the structure and the development of that event. The methodology consists in filtering the NCEP tropospheric forcing by zonal wave number and by phase speed. Our results show that mixing is significantly reduced precisely at the locations where the phase speeds of the filtered waves are close to the speed of the mean zonal wind, thus confirming the findings of previous studies. However, what is important here is that they validate the use of an approach based on the coupling of two models. The next step will consist in using the COMMID model in a more general way for further investigations of the impact of the tropospheric circulation on the isentropic transport in the stratosphere for climate sensitivity purposes.

Morel, BéAtrice; Bencherif, Hassan; Keckhut, Philippe; Portafaix, Thierry; Hauchecorne, Alain; Baldy, Serge

2005-09-01

327

Diurnal pattern of stomatal conductance in the large-leaved temperate liana Aristolochia macrophylla depends on spatial position within the leaf lamina  

PubMed Central

Background and Aims The large distance between peripheral leaf regions and the petiole in large leaves is expected to cause stronger negative water potentials at the leaf apex and marginal zones compared with more central or basal leaf regions. Leaf zone-specific differences in water supply and/or gas exchange may therefore be anticipated. In this study, an investigation was made to see whether zonal differences in gas exchange regulation can be detected in large leaves. Methods The diurnal course of stomatal conductance, gs, was monitored at defined lamina zones during two consecutive vegetation periods in the liana Aristolochia macrophylla that has large leaves. Local climate and stem water potential were also monitored to include parameters involved in stomatal response. Additionally, leaf zonal vein densities were measured to assess possible trends in local hydraulic supply. Key Results It was found that the diurnal pattern of gs depends on the position within a leaf in A. macrophylla. The highest values during the early morning were shown by the apical region, with subsequent decline later in the morning and a further gradual decline towards the evening. The diurnal pattern of gs at the marginal regions was similar to that of the leaf tip but showed a time lag of about 1 h. At the leaf base, the diurnal pattern of gs was similar to that of the margins but with lower maximum gs. At the the leaf centre regions, gs tended to show quite constant moderate values during most of the day. Densities of minor veins were lower at the margin and tip compared with the centre and base. Conclusions Gas exchange regulation appears to be zone specific in A. macrophylla leaves. It is suggested that the spatial–diurnal pattern of gs expressed by A. macrophylla leaves represents a strategy to prevent leaf zonal water stress and subsequent vein embolism.

Miranda, Tatiana; Ebner, Martin; Traiser, Christopher; Roth-Nebelsick, Anita

2013-01-01

328

COOH-terminal collagen Q (COLQ) mutants causing human deficiency of endplate acetylcholinesterase impair the interaction of ColQ with proteins of the basal lamina.  

PubMed

Collagen Q (ColQ) is a key multidomain functional protein of the neuromuscular junction (NMJ), crucial for anchoring acetylcholinesterase (AChE) to the basal lamina (BL) and accumulating AChE at the NMJ. The attachment of AChE to the BL is primarily accomplished by the binding of the ColQ collagen domain to the heparan sulfate proteoglycan perlecan and the COOH-terminus to the muscle-specific receptor tyrosine kinase (MuSK), which in turn plays a fundamental role in the development and maintenance of the NMJ. Yet, the precise mechanism by which ColQ anchors AChE at the NMJ remains unknown. We identified five novel mutations at the COOH-terminus of ColQ in seven patients from five families affected with endplate (EP) AChE deficiency. We found that the mutations do not affect the assembly of ColQ with AChE to form asymmetric forms of AChE or impair the interaction of ColQ with perlecan. By contrast, all mutations impair in varied degree the interaction of ColQ with MuSK as well as basement membrane extract (BME) that have no detectable MuSK. Our data confirm that the interaction of ColQ to perlecan and MuSK is crucial for anchoring AChE to the NMJ. In addition, the identified COOH-terminal mutants not only reduce the interaction of ColQ with MuSK, but also diminish the interaction of ColQ with BME. These findings suggest that the impaired attachment of COOH-terminal mutants causing EP AChE deficiency is in part independent of MuSK, and that the COOH-terminus of ColQ may interact with other proteins at the BL. PMID:24281389

Arredondo, Juan; Lara, Marian; Ng, Fiona; Gochez, Danielle A; Lee, Diana C; Logia, Stephanie P; Nguyen, Joanna; Maselli, Ricardo A

2014-05-01

329

Invasive cervical resorption: a review.  

PubMed

Invasive cervical resorption is a relatively uncommon form of external root resorption exhibiting no external signs. The resorptive condition is often detected by routine radiographic examination. The clinical features vary from a small defect at the gingival margin to a pink coronal discoloration of the tooth crown resulting in ultimate cavitation of the overlying enamel which is painless unless pulpal or periodontal infection supervenes. Radiographic features of lesions vary from well-delineated to irregularly bordered mottled radiolucencies, and these can be confused with dental caries. A characteristic radiopaque line generally separates the image of the lesion from that of the root canal, because the pulp remains protected by a thin layer of predentin until late in the process. Histopathologically, the lesions contain fibrovascular tissue with resorbing clastic cells adjacent to the dentin surface. More advanced lesions display fibro-osseous characteristics with deposition of ectopic bonelike calcifications both within the resorbing tissue and directly on the dentin surface. How to cite this article: Kandalgaonkar SD, Gharat LA, Tupsakhare SD, Gabhane MH. Invasive Cervical Resorption: A Review. J Int Oral Health 2013;5(6):124-30 . PMID:24453457

Kandalgaonkar, Shilpa D; Gharat, Leena A; Tupsakhare, Suyog D; Gabhane, Mahesh H

2013-12-01

330

Establishment risks for invasive species.  

PubMed

This article presents a quantitative methodology for evaluating the probability of invasive pest species establishing persistent populations. The estimation of pest establishment relies on data and information describing the biology and ecology of the pest and its interactions with potential host species and the regional environment. This information is developed using a model construct borrowed from theoretical population ecology. The methodology for estimating the probability of pest establishment is part of an overall framework that explores the implications of reductions in pest invasions on subsequent establishment. The risk reduction framework integrates the engineering aspects of different technologies for reducing pest entry, the biology and ecology of pest species, the suitability of potentially susceptible hosts, and the quality of available habitats. The methodology for estimating the risk of establishment is presented using an example pest, the Asian longhorned beetle (Anoplophora glabripennis), which has been introduced into the United States via solid wood packing materials (SWPM) used in international commerce. Uncertainties inherent to the estimation of model parameters that determine the risk of establishment are defined, quantified, and propagated through the population model. Advantages and limitations of the proposed methodology are discussed along with recommendations to make the approach more useful in the management of risks posed by the establishment of pest populations. PMID:15357803

Bartell, Steven M; Nair, Shyam K

2004-08-01

331

Non-Invasive Glucose Measurement  

NASA Astrophysics Data System (ADS)

There are two little words, when taken together have great implications: ``What IF'' In the US alone, there are millions who are burdened with diabetes and who must maintain their glucose levels by taking blood samples and having it analyzed. Even though this procedure has improved over time, still it is very intrusive and is a burden to many that must live with it. What if it were not necessary? Although it is current practice to measure glucose levels invasively (using blood samples), it may be possible to measure glucose non-invasively. Although several companies around the world have invested millions of dollars to address this problem, none have been successful thus far. However, there are many methods that hold a potential and many approaches that have not yet been explored. We are working on a review of what has been approached thus far and are entertaining proposals for a combined interdisciplinary approach which combines expertise from bioengineering, physics, and biology. We hope to learn from the unsuccessful attempts of others whilst employing innovative new approaches to this problem.

Blakley, Daniel

2010-10-01

332

Comparison of the Invasion of Crete and the Proposed Invasion in Malta.  

National Technical Information Service (NTIS)

In 1941, after the conquest of Yugoslavia and Greece, senior German military leaders were considering two airborne operations, one for the invasion of Crete and the other for the invasion of Malta. The invasion of Crete was executed from 20 May to 1 June ...

S. L. Kavanaugh

2006-01-01

333

Invasive plants and their ecological strategies: Prediction and explanation of woody plant invasion in New England  

USGS Publications Warehouse

Effective management of introduced species requires the early identification of species that pose a significant threat of becoming invasive. To better understand the invasive ecology of species in New England, USA, we compiled a character data set with which to compare non-native species that are known invaders to non-native species that are not currently known to be invasive. In contrast to previous biological trait-based models, we employed a Bayesian hierarchical analysis to identify sets of plant traits associated with invasiveness for each of three growth forms (vines, shrubs, and trees). The resulting models identify a suite of 'invasive traits' highlighting the ecology associated with invasiveness for each of three growth forms. The most effective predictors of invasiveness that emerged from our model were 'invasive elsewhere', 'fast growth rate', 'native latitudinal range', and 'growth form'. The contrast among growth forms was pronounced. For example, 'wind dispersal' was positively correlated with invasiveness in trees, but negatively correlated in shrubs and vines. The predictive model was able to correctly classify invasive plants 67% of the time (22/33), and non-invasive plants 95% of the time (204/215). A number of potential future invasive species in New England that deserve management consideration were identified. ?? 2007 The Authors.

Herron, P. M.; Martine, C. T.; Latimer, A. M.; Leicht-Young, S. A.

2007-01-01

334

A human breast cell model of pre-invasive to invasive transition  

Microsoft Academic Search

A crucial step in human breast cancer progression is the acquisition of invasiveness. There is a distinct lack of human cell culture models to study the transition from pre-invasive to invasive phenotype as it may occur 'spontaneously' in vivo. To delineate molecular alterations important for this transition, we isolated human breast epithelial cell lines that showed partial loss of tissue

Mina J Bissell; Aylin Rizki; Valerie M. Weaver; Sun-Young Lee; Gabriela I. Rozenberg; Koei Chin; Connie A. Myers; Jamie L. Bascom; Joni D. Mott; Jeremy R. Semeiks; Leslie R. Grate; I. Saira Mian; Alexander D. Borowsky; Roy A. Jensen; Michael O. Idowu; Fanqing Chen; David J. Chen; Ole W. Petersen; Joe W. Gray

2008-01-01

335

Lysophosphatidic acid and sphingosine-1-phosphate promote morphogenesis and block invasion of prostate cancer cells in three-dimensional organotypic models  

PubMed Central

Normal prostate and some malignant prostate cancer (PrCa) cell lines undergo acinar differentiation and form spheroids in three-dimensional (3-D) organotypic culture. Acini formed by PC-3 and PC-3M, less pronounced also in other PrCa cell lines, spontaneously undergo an invasive switch, leading to the disintegration of epithelial structures and the basal lamina, and formation of invadopodia. This demonstrates the highly dynamic nature of epithelial plasticity, balancing epithelial-to-mesenchymal transition against metastable acinar differentiation. This study assessed the role of lipid metabolites on epithelial maturation. PC-3 cells completely failed to form acinar structures in delipidated serum. Adding back lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) rescued acinar morphogenesis and repressed invasion effectively. Blocking LPA receptor 1 (LPAR1) functions by siRNA (small interference RNA) or the specific LPAR1 inhibitor Ki16425 promoted invasion, while silencing of other G-protein-coupled receptors responsive to LPA or S1P mainly caused growth arrest or had no effects. The G-proteins G?12/13 and G?i were identified as key mediators of LPA signalling via stimulation of RhoA and Rho kinases ROCK1 and 2, activating Rac1, while inhibition of adenylate cyclase and accumulation of cAMP may be secondary. Interfering with these pathways specifically impeded epithelial polarization in transformed cells. In contrast, blocking the same pathways in non-transformed, normal cells promoted differentiation. We conclude that LPA and LPAR1 effectively promote epithelial maturation and block invasion of PrCa cells in 3-D culture. The analysis of clinical transcriptome data confirmed reduced expression of LPAR1 in a subset of PrCa's. Our study demonstrates a metastasis-suppressor function for LPAR1 and G?12/13 signalling, regulating cell motility and invasion versus epithelial maturation.

Harma, V; Knuuttila, M; Virtanen, J; Mirtti, T; Kohonen, P; Kovanen, P; Happonen, A; Kaewphan, S; Ahonen, I; Kallioniemi, O; Grafstrom, R; Lotjonen, J; Nees, M

2012-01-01

336

Invasive Pituitary Adenomas: Significance of Proliferation Parameters  

Microsoft Academic Search

Although most pituitary adenomas behave in a purely benign fashion, microscopic invasion of the subjacent dura is very common, and clinically overt infiltration of the surrounding dura and bone is apparent at intraoperative inspection in about one third of cases. The factors governing invasive behavior remain unknown but are believed to be separate from those regulating cell proliferation. Histological features

ArunPaul Amar; David R. Hinton; Mark D. Krieger; Martin H. Weiss

1999-01-01

337

Predicting Invasion in Mammographically Detected Microcalcification  

Microsoft Academic Search

AIM: To identify pre-operative factors which predict presence of invasive disease within mammographically detected malignant microcalcification. MATERIALS AND METHODS: A retrospective analysis was undertaken of 116 serial stereotactic core needle biopsies (SCNBs) performed on malignant mammographic calcification. Final surgical pathology was correlated with pre-operative features (clinical, radiological and core histology) in an attempt to predict the presence of an invasive

Mark J. C. Bagnall; Andrew J. Evans; A. Robin M. Wilson; Sarah E. Pinder; Helen Denley; James G. Geraghty; Ian O. Ellis

2001-01-01

338

Invasion Waves in Populations with Excitable Dynamics  

Microsoft Academic Search

Whilst the most obvious mechanism for a biological invasion is the occupation of a new territory as a result of direct ingress by individuals of the invading population, a more subtle “invasion” may occur without significant motion of invading individuals if the population dynamics in a predator prey scenario has an “excitable” character. Here, “excitable” means that a local equilibrium

J. Brindley; V. H. Biktashev; M. A. Tsyganov

2005-01-01

339

Matrix metalloproteinases in tumor invasion and metastasis  

Microsoft Academic Search

Extensive work on the mechanisms of tumor invasion and metastasis has identified matrix metalloproteinases (MMPs) as key players in the events that underlie tumor dissemination. Studies using natural and synthetic MMP inhibitors, as well as tumor cells transfected with cDNAs encoding the MMPs characterized thus far have provided compelling evidence that MMP activity can induce or enhance tumor survival, invasion

Ivan Stamenkovic

2000-01-01

340

How trade politics affect invasive species control  

Microsoft Academic Search

Trade has become the main mode of transport for many invasive species, including diseases and agricultural pests. Most species are brought to their new homes unintentionally, which constitutes a market failure rooted in international trade. Unless it is practical to drive invasion risk to zero, the external costs may justify a tariff. In this paper, we analyze the political process

Michael Margolis; Jason F. Shogren; Carolyn Fischer

2005-01-01

341

The ecology of forest insect invasions and  

Microsoft Academic Search

Invasions by nonindigenous forest insects can have spectacular effects on the biodiversity, ecology, and economy of affected areas. This introduction explores several critical issues that are generally relevant to invasions by forest in- sects to provide an extended background for this special issue of the Cundiun Jourrtal ($* fi)re,st Research and highligllts the key findings of the papers included in

Eckehard G. BrockerhofV; Andrew M. Liebhold; Hewe Jactel

2006-01-01

342

The Invasive Plant Species Education Guide  

NSDL National Science Digital Library

To help high school students gain a solid understanding of invasive plant species, university faculty and students from the University of Wisconsin-Stout (UW-Stout) and a local high school teacher worked together to develop the Invasive Plant Species (IPS

D'Angelo, Jean; Mason, Kevin; Carlson, Kitrina; James, Krista

2010-04-01

343

The Invasive Plant Species Education Guide  

ERIC Educational Resources Information Center

To help high school students gain a solid understanding of invasive plant species, university faculty and students from the University of Wisconsin-Stout (UW-Stout) and a local high school teacher worked together to develop the Invasive Plant Species (IPS) Education Guide. The IPS Education Guide includes nine lessons that give students an…

Mason, Kevin; James, Krista; Carlson, Kitrina; D'Angelo, Jean

2010-01-01

344

Minimally invasive treatment of thoracic disc herniations.  

PubMed

In the past, treatment of thoracic disc herniations has not been seen as a minimally invasive procedure. This article evaluates the progression of minimally invasive techniques for the treatment of thoracic disc herniations. Discussion of the advantages and disadvantages of the approaches is noted so that surgeons may consider them while incorporating these techniques in their practice. PMID:24703446

Snyder, Laura A; Smith, Zachary A; Dahdaleh, Nader S; Fessler, Richard G

2014-04-01

345

Ecological and evolutionary consequences of coastal invasions  

Microsoft Academic Search

Although coastal estuarine and marine systems are among the most heavily invaded systems in the world, the study of nonindigenous species in these systems has, historically, lagged behind that of terrestrial and freshwater systems. However, in the past decade, a rapid increase in studies of coastal invasions has provided important insight into the invasion process in these systems and how

Edwin Grosholz

2002-01-01

346

Non-invasive diagnosis of pulmonary embolism  

Microsoft Academic Search

Pulmonary embolism (PE) remains a challenging diagnostic problem because it mimics other cardiopulmonary disorders. Pulmonary angiography is still the reference standard for diagnosing PE but it is costly, invasive and not readily available. Non-invasive diagnostic strategies have therefore been developed to forego pulmonary angiography in patients suspected of having PE. Ventilation\\/perfusion lung scanning is, at present, the most widely used

Massimo Miniati; Carlo Marini; Germana Allescia; Lucia Tonelli; Bruno Formichi; Renato Prediletto; Giorgio Di Ricco; Carolina Bauleo; Massimo Pistolesi

1998-01-01

347

Options for Managing Invasive Marine Species  

Microsoft Academic Search

Marine biological invasions are increasingly recognised as a threat to biodiversity and coastal industry, including fisheries. Globally, efforts are underway to contain, if not eradicate, several high-impact marine invasive species. However, working in a marine environment places unique social, political and technical constraints on options for pest control, which we explored in a series of stakeholder workshops. Results suggest that

Ronald E. Thresher; Armand M. Kuris

2004-01-01

348

Brain tumor epidemiology, growth, and invasion.  

PubMed

This article focuses on the most common primary intracranial neoplasms and the biologic descriptions of their growth and invasion. The proliferative aspects of the different primary brain tumors are discussed, along with recently discovered genetic changes. Because local invasion of primary brain tumors is a key pathologic feature of these tumors, the mechanisms known to influence cell movement are discussed. PMID:2135961

Berens, M E; Rutka, J T; Rosenblum, M L

1990-01-01

349

Non-invasive glucose monitor  

NASA Technical Reports Server (NTRS)

A non-invasive method for determining blood level of an analyte of interest, such as glucose, comprises: generating an excitation laser beam (e.g., at a wavelength of 700 to 900 nanometers); focusing the excitation laser beam into the anterior chamber of an eye of the subject so that aqueous humor in the anterior chamber is illuminated; detecting (preferably confocally detecting) a Raman spectrum from the illuminated aqueous humor; and then determining the blood glucose level (or the level of another analyte of interest) for the subject from the Raman spectrum. Preferably, the detecting step is followed by the step of subtracting a confounding fluorescence spectrum from the Raman spectrum to produce a difference spectrum; and determining the blood level of the analyte of interest for the subject from that difference spectrum, preferably using linear or nonlinear multivariate analysis such as partial least squares analysis. Apparatus for carrying out the foregoing method is also disclosed.

Lambert, James L. (Inventor); Borchert, Mark S. (Inventor)

2001-01-01

350

Minimally invasive carpal tunnel release.  

PubMed

We prospectively compared the safety and effectiveness of mini-incision (group A) and a limited open technique (group B) for carpal tunnel release (CTR) in 185 consecutive patients operated between November 1999 and May 2001, with a 5-year minimum follow-up. Patients in Group A had a minimally invasive approach (<2 cm incision), performed using the KnifeLight (Stryker, Kalamazoo, Michigan) instrument. Patients in Group B had a limited longitudinal incision (3-4 cm). Patient status was evaluated with an Italian modified version of the Boston Carpal Tunnel questionnaire, administered preoperatively and at 19, 30, and 60 postoperative months. Mini-incision CTR showed advantages over standard technique in early recovery, pillar pain, and recurrence rate. The recovery period after mini-incision is shorter than after standard procedure. PMID:19773048

Cellocco, Paolo; Rossi, Costantino; El Boustany, Stefano; Di Tanna, Gian Luca; Costanzo, Giuseppe

2009-10-01

351

Dynamic Fiber Composite Continuum Model of the Tympanic Membrane. Part 1. Model Formulation.  

National Technical Information Service (NTIS)

Fibrous layers of the lamina propria influence dynamic behavior of the tympanic membrane by producing strong anisotropic extensional stiffness, while the mucous and epidermal layers are primarily responsible for curvature dependent structural damping and ...

R. D. Rabbitt

1985-01-01

352

Cholecystitis in Guinea Pigs Following Opium.  

National Technical Information Service (NTIS)

Acute cholecystitis was produced in normal guinea pigs given intraperitoneal injections of 1.0 ml tincture of opium. Repeated injections of opium caused edema of the lamina propria and severe muscular hypertrophy. Occasional Rokitansky-Aschoff sinuses wer...

H. B. Goldstein

1966-01-01

353

Ecological and evolutionary insights from species invasions.  

PubMed

Species invasions provide numerous unplanned and frequently, but imperfectly, replicated experiments that can be used to better understand the natural world. Classic studies by Darwin, Grinnell, Elton and others on these species-invasion experiments provided invaluable insights for ecology and evolutionary biology. Recent studies of invasions have resulted in additional insights, six of which we discuss here; these insights highlight the utility of using exotic species as 'model organisms'. We also discuss a nascent hypothesis that might provide a more general, predictive understanding of invasions and community assembly. Finally, we emphasize how the study of invasions can help to inform our understanding of applied problems, such as extinction, ecosystem function and the response of species to climate change. PMID:17640765

Sax, Dov F; Stachowicz, John J; Brown, James H; Bruno, John F; Dawson, Michael N; Gaines, Steven D; Grosberg, Richard K; Hastings, Alan; Holt, Robert D; Mayfield, Margaret M; O'Connor, Mary I; Rice, William R

2007-09-01

354

Mitochondrial redox signaling and cancer invasiveness.  

PubMed

The concept that invasive cancer is associated with increased levels of reactive oxygen species (ROS) generated by mitochondria is consistent with an ROS-mediated signaling mechanism. As a tumor grows, it encounters adverse microenvironments, one of which is low oxygen (hypoxia), which selects tumor cells with characteristics of increased invasiveness. Hypoxic environments select for tumor cells with stabilized HIF1 apha, a transcription factor that regulates genes coding for pro-tumor cytokines that signal stromal cells such as macrophages and fibroblasts to support an invasive tumor cell phenotype. HIF1 alpha-mediated switches in the energy production of tumor cells from OXPHOS to glycolysis, as well as age-associated decreases in the metabolic rate of the host, enhance invasive qualities of tumor cells. An increase in environmental oxygen in combination with a mitochondrial targeted catalase mimetic and a metabolism booster may be of interest to investigate as a treatment strategy for invasive cancer. PMID:22886605

Enns, Linda; Ladiges, Warren

2012-12-01

355

Foam invasion through a single pore  

NASA Astrophysics Data System (ADS)

We investigate experimentally the behavior of liquid foams pumped at a given flow rate through a single pore, in the situation where the pore diameter is smaller than the bubble diameter. Results reveal that foam invasion can be observed only within a restricted range of values for the dimensionless flow rate and the foam liquid fraction. Within this foam invasion regime, the liquid content of invading foams is measured to be three times higher than the initial liquid content. Outside this regime, both gas alone and liquid alone invasion regimes can be observed. The gas invasion regime results from the rupture of foam films during local T1, during bubble rearrangements events induced by foam flow, whereas the liquid invasion regime is allowed by the formation of a stable cluster of jammed bubbles at the pore's opening.

Delbos, Aline; Pitois, Olivier

2011-07-01

356

Genomic comparison of invasive and rare non-invasive strains reveals Porphyromonas gingivalis genetic polymorphisms  

PubMed Central

Background Porphyromonas gingivalis strains are shown to invade human cells in vitro with different invasion efficiencies, varying by up to three orders of magnitude. Objective We tested the hypothesis that invasion-associated interstrain genomic polymorphisms are present in P. gingivalis and that putative invasion-associated genes can contribute to P. gingivalis invasion. Design Using an invasive (W83) and the only available non-invasive P. gingivalis strain (AJW4) and whole genome microarrays followed by two separate software tools, we carried out comparative genomic hybridization (CGH) analysis. Results We identified 68 annotated and 51 hypothetical open reading frames (ORFs) that are polymorphic between these strains. Among these are surface proteins, lipoproteins, capsular polysaccharide biosynthesis enzymes, regulatory and immunoreactive proteins, integrases, and transposases often with abnormal GC content and clustered on the chromosome. Amplification of selected ORFs was used to validate the approach and the selection. Eleven clinical strains were investigated for the presence of selected ORFs. The putative invasion-associated ORFs were present in 10 of the isolates. The invasion ability of three isogenic mutants, carrying deletions in PG0185, PG0186, and PG0982 was tested. The PG0185 (ragA) and PG0186 (ragB) mutants had 5.1×103-fold and 3.6×103-fold decreased in vitro invasion ability, respectively. Conclusion The annotation of divergent ORFs suggests deficiency in multiple genes as a basis for P. gingivalis non-invasive phenotype.

Dolgilevich, Svetlana; Rafferty, Brian; Luchinskaya, Darya; Kozarov, Emil

2011-01-01

357

Study of melanoma invasion by FTIR spectroscopy  

NASA Astrophysics Data System (ADS)

Compared to other forms of skin cancer, a malignant melanoma has a high risk of spreading to other parts of the body. Melanoma invasion is a complex process involving changes in cell-extracellular matrix (ECM) interaction and cell-cell interactions. To fully understand the factors which control the invasion process, a human skin model system was reconstructed. HBL (a commercially available cell line) melanoma cells were seeded on a skin model with and without the presence of keratinocytes and/or fibroblasts. After 14 days culture, the skin specimens were fixed, parafin embedded and cut into 7 µm sections. The de-parafinised sections were investigated by synchrotron Fourier transformed infrared (FTIR) microspectroscopy to study skin cell invasion behaviour. The advantage of using FTIR is its ability to obtain the fingerprint information of the invading cells in terms of protein secondary structure in comparison to non-invading cells and the concentration of the enzyme (matrix-metalloproteinase) which digests protein matrix, near the invading cells. With aid of the spectral mapping images, it is possible to pinpoint the cells in non-invasion and invasion area and analyse the respective spectra. It has been observed that the protein bands in cells and matrix shifted between non-invasive and invasive cells in the reconstructed skin model. We hypothesise that by careful analysis of the FTIR data and validation by other models, FTIR studies can reveal information on which type of cells and proteins are involved in melanoma invasion. Thus, it is possible to trace the cell invasion path by mapping the spectra along the interface of cell layer and matrix body by FTIR spectroscopy.

Yang, Y.; Sulé-Suso, J.; Sockalingum, G. D.

2008-03-01

358

San Francisco Estuary: Invasive Spartina Project  

NSDL National Science Digital Library

The Invasive Spartina Project was developed by the California State Coastal Conservancy to determine the extent and address the problem of invasive Spartina in the San Francisco Estuary. This Web site describes the efforts of the Invasive Spartina Project and the risk that Spartina poses. A variety of maps and photos are used to describe the results of the 2000-2001 survey of Spartina populations within the estuary. A host of other documents regarding Spartina and this project are also available in Adobe Acrobat (.pdf) format.

2002-01-01

359

BRASSINOSTEROID UPREGULATED1, Encoding a Helix-Loop-Helix Protein, Is a Novel Gene Involved in Brassinosteroid Signaling and Controls Bending of the Lamina Joint in Rice1[W][OA  

PubMed Central

Brassinosteroids (BRs) are involved in many developmental processes and regulate many subsets of downstream genes throughout the plant kingdom. However, little is known about the BR signal transduction and response network in monocots. To identify novel BR-related genes in rice (Oryza sativa), we monitored the transcriptomic response of the brassinosteroid deficient1 (brd1) mutant, with a defective BR biosynthetic gene, to brassinolide treatment. Here, we describe a novel BR-induced rice gene BRASSINOSTEROID UPREGULATED1 (BU1), encoding a helix-loop-helix protein. Rice plants overexpressing BU1 (BU1:OX) showed enhanced bending of the lamina joint, increased grain size, and resistance to brassinazole, an inhibitor of BR biosynthesis. In contrast to BU1:OX, RNAi plants designed to repress both BU1 and its homologs displayed erect leaves. In addition, compared to the wild type, the induction of BU1 by exogenous brassinolide did not require de novo protein synthesis and it was weaker in a BR receptor mutant OsbriI (Oryza sativa brassinosteroid insensitive1, d61) and a rice G protein alpha subunit (RGA1) mutant d1. These results indicate that BU1 protein is a positive regulator of BR response: it controls bending of the lamina joint in rice and it is a novel primary response gene that participates in two BR signaling pathways through OsBRI1 and RGA1. Furthermore, expression analyses showed that BU1 is expressed in several organs including lamina joint, phloem, and epithelial cells in embryos. These results indicate that BU1 may participate in some other unknown processes modulated by BR in rice.

Tanaka, Atsunori; Nakagawa, Hitoshi; Tomita, Chikako; Shimatani, Zenpei; Ohtake, Miki; Nomura, Takahito; Jiang, Chang-Jie; Dubouzet, Joseph G.; Kikuchi, Shoshi; Sekimoto, Hitoshi; Yokota, Takao; Asami, Tadao; Kamakura, Takashi; Mori, Masaki

2009-01-01

360

Galactomannan antigenemia in invasive aspergillosis.  

PubMed Central

Galactomannan (GM) extracted from mycelia of Aspergillus fumigatus with cold dilute alkali reacted with antiserum specific for an antigen that circulated in invasive aspergillosis in rabbits and humans. The GM was purified by its affinity for concanavalin A and was separated from a nonantigenic glucan by gel permeation on Sephacryl S-200. The GM molecular weight of between 25,000 to 75,000 was smaller than the antigen present in infected rabbit serum which was retained by an ultrafiltration membrane that had a nominal molecular weight limit of 125,000. The ratio of galactose to mannose present in GM was 1:1.17. The serological activity of GM was stable to boiling but labile to 0.01 N HCl, implicating galactofuranose as an antigenic determinant. Analysis of purified GM by methylation-gas chromatography suggested a structure consisting of a 1 leads to 6-linked mannan backbone with oligogalactoside side chains 3 units long, terminating in galactofuranose. The presence of mannose as a side chain component was also inferred. Another antigen of A. fumigatus, which did not bind to concanavalin A, was isolated after tandem chromatography on diethylaminoethyl- and carboxymethyl-Sephadex and was identified as a galactan. The galactan inhibited the immune precipitation of GM was specific antiserum. Images

Reiss, E; Lehmann, P F

1979-01-01

361

Mechanobiology of tumor invasion: engineering meets oncology  

PubMed Central

The physical sciences and engineering have introduced novel perspectives into the study of cancer through model systems, tools, and metrics that enable integration of basic science observations with clinical data. These methods have contributed to the identification of several overarching mechanisms that drive processes during cancer progression including tumor growth, angiogenesis, and metastasis. During tumor cell invasion – the first clinically observable step of metastasis – cells demonstrate diverse and evolving physical phenotypes that cannot typically be defined by any single molecular mechanism, and mechanobiology has been used to study the physical cell behaviors that comprise the “invasive phenotype”. In this review, we discuss the continually evolving pathological characterization and in vitro mechanobiological characterization of tumor invasion, with emphasis on emerging physical biology and mechanobiology strategies that have contributed to a more robust mechanistic understanding of tumor cell invasion. These physical approaches may ultimately help to better predict and identify tumor metastasis.

Carey, Shawn P.; D'Alfonso, Timothy M.; Shin, Sandra J.; Reinhart-King, Cynthia A.

2011-01-01

362

Council Coordination of Federal Invasive Species Efforts.  

National Technical Information Service (NTIS)

Invasive species can be plants, animals or microorganisms: (1) Species that are not native to the ecosystem under consideration and (2) Whose introduction causes or is likely to cause economic or environmental harm or harm to human health.

C. Dionigi

2004-01-01

363

Isolated Uterine Metastasis of Invasive Ductal Carcinoma  

PubMed Central

Introduction. Most common metastasis sites of breast cancer are the lungs, bones, liver, and brain, whereas uterine involvement by metastatic breast disease is rare. Metastatic carcinoma of the uterus usually originates from other genital sites, most commonly being from the ovaries. Invasive lobular carcinoma spreads to gynecologic organs more frequently than invasive ductal carcinoma. Case Report. A 57-year-old postmenopausal woman was diagnosed with breast carcinoma 2 years ago and modified radical mastectomy was performed. Pathological examination of tumor revealed invasive ductal carcinoma, stage IIIc. She presented with abdominal pain and distension. Diagnostic workup and gynecologic examination revealed lesions that caused diffuse thickening of the uterus wall. Endometrial sampling was performed for confirmation of the diagnosis. She underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy. Breast carcinoma metastases in endometrium and myometrium were confirmed histopathologically and immunohistochemically. Conclusion. We herein report the first case of isolated uterine patient who had invasive ductal carcinoma of breast.

Arslan, Deniz; Tural, Deniz; Tatl?, Ali Murat; Akar, Emre; Uysal, Mukremin; Erdogan, Gulgun

2013-01-01

364

76 FR 30955 - Invasive Species Advisory Committee  

Federal Register 2010, 2011, 2012, 2013

...management of invasive species in the vast Rocky Mountain/High Plains region in order to gain new understanding of landscape ecology, climate change, land development, introduction pathways, and new invaders. ISAC will also consult with...

2011-05-27

365

Minimally invasive surgery for Achilles tendon pathologies  

PubMed Central

Minimally invasive trauma and orthopedic surgery is increasingly common, though technically demanding. Its use for pathologies of the Achilles tendon (AT) hold the promise to allow faster recovery times, shorter hospital stays, and improved functional outcomes when compared to traditional open procedures, which can lead to difficulty with wound healing because of the tenuous blood supply and increased chance of wound breakdown and infection. We present the recent advances in the field of minimally invasive AT surgery for tendinopathy, acute ruptures, chronic tears, and chronic avulsions of the AT. In our hands, minimally invasive surgery has provided similar results to those obtained with open surgery, with decreased perioperative morbidity, decreased duration of hospital stay, and reduced costs. So far, the studies on minimally invasive orthopedic techniques are of moderate scientific quality with short follow-up periods. Multicenter studies with longer follow-up are needed to justify the long-term advantages of these techniques over traditional ones.

Maffulli, Nicola; Longo, Umile Giuseppe; Spiezia, Filippo; Denaro, Vincenzo

2010-01-01

366

Recent Trends in Minimally Invasive Cardiac Surgery  

Microsoft Academic Search

Evolving technologies have resulted in an increase in minimally invasive cardiac surgery. Currently, robotic systems allow surgeons to perform a variety of procedures through small incisions. This changing paradigm is reviewed.

Alan P. Kypson

2007-01-01

367

76 FR 68776 - Invasive Species Advisory Committee  

Federal Register 2010, 2011, 2012, 2013

...control and minimizing the economic, ecological, and human health impacts that invasive...Department of Commerce (Herbert C. Hoover Building), 1401 Constitution Avenue NW., Washington...of the public must be cleared through building security prior to being escorted to...

2011-11-07

368

75 FR 69698 - Invasive Species Advisory Committee  

Federal Register 2010, 2011, 2012, 2013

...providing for their control and minimizing the economic, ecological, and human health impacts that invasive species cause. The...and interested members of the public must be cleared through building security prior to being escorted to the meeting. FOR...

2010-11-15

369

78 FR 70317 - Invasive Species Advisory Committee  

Federal Register 2010, 2011, 2012, 2013

...providing for their control and minimizing the economic, ecological, and human health impacts that invasive species cause. The...All visiting members of the public must be cleared through building security prior to being escorted to the meeting...

2013-11-25

370

EMT, the cytoskeleton, and cancer cell invasion  

Microsoft Academic Search

The metastatic process, i.e. the dissemination of cancer cells throughout the body to seed secondary tumors at distant sites,\\u000a requires cancer cells to leave the primary tumor and to acquire migratory and invasive capabilities. In a process of epithelial-mesenchymal\\u000a transition (EMT), besides changing their adhesive repertoire, cancer cells employ developmental processes to gain migratory\\u000a and invasive properties that involve a

Mahmut Yilmaz; Gerhard Christofori

2009-01-01

371

Does consumer injury modify invasion impact?  

Microsoft Academic Search

Predicting the impacts of an invasive species solely by its abundance is common, yet it ignores other potentially important\\u000a moderating factors. One such factor is injury. Severe injury can lead to mortality, which can directly reduce the abundance\\u000a of the invader. However, more moderate, sublethal injury can also temper the impact of invasive species. Therefore, to predict\\u000a impacts, it may

David G. DelaneyBlaine; Blaine D. Griffen; Brian Leung

372

Molecular epidemiology of nosocomial invasive aspergillosis.  

PubMed Central

Moderately repeated DNA sequences were used to fingerprint strains of Aspergillus fumigatus isolated from patients with invasive aspergillosis and their hospital environment. Most strains sampled from the environment displayed different Southern blot hybridization patterns. A temporal survey of air contaminants showed that some strains can persist in the same environment for at least 6 months. Patients with invasive aspergillosis were infected by a single strain. In two patients, a nosocomial origin of infection was suggested. Images

Girardin, H; Sarfati, J; Traore, F; Dupouy Camet, J; Derouin, F; Latge, J P

1994-01-01

373

Genetics of Invasive Species in New Zealand  

Microsoft Academic Search

Genetic effects following the colonization and invasion of New Zealand have been studied in relatively few cases for a variety\\u000a of reasons. The outcomes of these studies have shown that there are ranges of genetic effects that do occur after colonization,\\u000a although it is often difficult to attribute genetics as a factor in the success or failure of invasive species.

D. Gleeson; H. Harman; T. Armstrong

374

The evolution of invasiveness in garden ants.  

PubMed

It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its rapid spread through Europe and Asia as the most recent example of a pest ant that may become a global problem. Here, we present the first integrated study on behavior, morphology, population genetics, chemical recognition and parasite load of L. neglectus and its non-invasive sister species L. turcicus. We find that L. neglectus expresses the same supercolonial syndrome as other invasive ants, a social system that is characterized by mating without dispersal and large networks of cooperating nests rather than smaller mutually hostile colonies. We conclude that the invasive success of L. neglectus relies on a combination of parasite-release following introduction and pre-adaptations in mating system, body-size, queen number and recognition efficiency that evolved long before introduction. Our results challenge the notion that supercolonial organization is an inevitable consequence of low genetic variation for chemical recognition cues in small invasive founder populations. We infer that low variation and limited volatility in cuticular hydrocarbon profiles already existed in the native range in combination with low dispersal and a highly viscous population structure. Human transport to relatively disturbed urban areas thus became the decisive factor to induce parasite release, a well established general promoter of invasiveness in non-social animals and plants, but understudied in invasive social insects. PMID:19050762

Cremer, Sylvia; Ugelvig, Line V; Drijfhout, Falko P; Schlick-Steiner, Birgit C; Steiner, Florian M; Seifert, Bernhard; Hughes, David P; Schulz, Andreas; Petersen, Klaus S; Konrad, Heino; Stauffer, Christian; Kiran, Kadri; Espadaler, Xavier; d'Ettorre, Patrizia; Aktaç, Nihat; Eilenberg, Jørgen; Jones, Graeme R; Nash, David R; Pedersen, Jes S; Boomsma, Jacobus J

2008-01-01

375

Facts About Invasive Bighead and Silver Carps  

USGS Publications Warehouse

The U.S. Geological Survey (USGS) scientists at the Columbia Environmental Research Center (CERC), Columbia, Missouri, carry out basic and applied research on the ecology of invasive fishes in the Missouri and Mississippi river basins. Emphasis is placed on improving understanding of the life cycles of bighead and silver carp to provide information needed to manage these aggressively invasive species. USGS scientists collaborate with Federal and State management agencies and universities, nationally and internationally, to fill critical science information gaps.

Chapman, Duane C.

2010-01-01

376

Invasive pneumococcal disease in Australia, 2002  

Microsoft Academic Search

There were 2,271 cases of invasive pneumococcal disease (IPD) notifi ed to the National Notifi able Diseases Surveillance System in Australia in 2002; a rate of 11.5 cases per 100,000 population. The notifi cation rate varied between states and territories and by geographical region with the highest rates in the north of the country. Invasive pneumococcal disease was reported most

Paul Roche; Vicki Krause; Ross Andrews; Louise Carter; David Coleman; Heather Cook; Megan Counahan; Ros Holland; Riemke Kampen; Mitchell Brown; Lyn Gilbert; Geoff Hogg; Denise Murphy

377

Minnesota horticultural industry survey on invasive plants  

Microsoft Academic Search

Summary  Horticultural commerce of ornamental plants has been the source of many of our most troublesome plant invaders worldwide.\\u000a The purpose of this research was to document the knowledge gap of industry perspectives and knowledge of invasive ornamental\\u000a crops by surveying industry professionals in the Midwest region of the U.S. (primarily in the state of Minnesota). An invasive\\u000a plant survey was

William L. Peters; Mary Hockenberry Meyer; Neil O. Anderson

2006-01-01

378

Langerhans cell histiocytosis of the urinary bladder in a patient with bladder cancer previously treated with intravesical Bacillus Calmette-Guérin therapy.  

PubMed

We report an extremely rare case of Langerhans cell histiocytosis (LCH) of the urinary bladder. A 68-year-old man presented with gross hematuria. Cystoscopy showed multiple papillary tumors in the urinary bladder, and transurethral resection was performed. Pathological diagnosis was high-grade papillary urothelial carcinoma with lamina propria invasion. The patient received six treatments with intravesical Bacillus Calmette-Guérin (BCG) therapy. Seven months after surgery, follow-up cystoscopy showed three elevated lesions in the urinary bladder, two of which were identified histologically as recurrent urothelial carcinoma. Microscopic examination of the lesion at the anterior wall revealed diffuse infiltration of medium to large histiocytoid cells in the lamina propria, many of which had distorted nuclei and nuclear grooves. Dense eosinophilic infiltration was also observed. Immunohistochemically, the histiocytoid cells were diffusely positive for S-100 and CD1a, but negative for cytokeratin AE1/AE3 and melanosome-associated antigen recognized by HMB-45. Based on the histological and immunohistochemical features, we diagnosed the lesion as LCH of the urinary bladder. There was no evidence of recurrence of either bladder cancer or LCH after an 18-month follow-up. To avoid misdiagnosis, urologists and pathologists should be aware that LCH may develop in the urinary bladder after intravesical BCG therapy for bladder cancer. PMID:24332601

Numakura, Satoe; Morikawa, Teppei; Ushiku, Tetsuo; Toyoshima, Toyoaki; Fukayama, Masashi

2014-02-01

379

Allocating biosecurity resources between preventing, detecting, and eradicating island invasions  

Microsoft Academic Search

Finding efficient ways to manage the threat of invasive species helps make the most of limited resources. Different management actions reduce the impact of invasions differently: preventing invasion eliminates impacts entirely, surveillance can facilitate early detection and eradication, and removing individuals can reduce future impact. Few studies have examined the trade-off between all three facets of invasion management. Using a

Tracy M. Rout; Joslin L. Moore; Hugh P. Possingham; Michael A. McCarthy

2011-01-01

380

Invasion and MMP expression profile in desmoid tumours  

Microsoft Academic Search

Desmoid tumours are locally invasive soft tissue tumours in which ?-catenin mediated TCF-dependent transcription is activated. The role of soluble factors secreted by the myofibroblastic desmoid tumour, which could stimulate tumour invasiveness, was investigated. Using collagen gel invasion assays, the presence of factors stimulating invasion in desmoid conditioned media (CM) could be established. Since matrix metalloproteinases (MMPs) have been implicated

H Denys; O De Wever; B Nusgens; Y Kong; R Sciot; A-T Le; K Van Dam; A Jadidizadeh; S Tejpar; M Mareel; B Alman; J-J Cassiman

2004-01-01

381

Clinicopathologic studies on perineural invasion of bile duct carcinoma.  

PubMed Central

To elucidate the clinical significance of perineural invasion on bile duct cancer, a clinicopathologic study was performed on 70 resected patients with bile duct carcinoma. The overall incidence of perineural invasion in the resected specimen was 81.4%. There seemed to be no correlation between perineural invasion and site, size of the tumor, and lymph node metastasis. A significant correlation was observed, however, between macroscopic type, microscopic type, depth of invasion, and perineural invasion. Perineural invasion index (PNI) was defined as the ratio between the number of nerve fibers invaded by cancer and the total number of nerve fibers with and without cancer invasion. Perineural invasion index was significantly higher at the center compared with the proximal and distal part of the tumor (p less than 0.001). The 5-year survival rate for patients with perineural invasion was significantly lower (p less than 0.05) than that for those without perineural invasion (67% versus 32%). Images FIG. 1.

Bhuiya, M R; Nimura, Y; Kamiya, J; Kondo, S; Fukata, S; Hayakawa, N; Shionoya, S

1992-01-01

382

Roles for herpes simplex virus type 1 U{sub L}34 and U{sub S}3 proteins in disrupting the nuclear lamina during herpes simplex virus type 1 egress  

SciTech Connect

Cells infected with wild type HSV-1 showed significant lamin A/C and lamin B rearrangement, while U{sub L}34-null virus-infected cells exhibited few changes in lamin localization, indicating that U{sub L}34 is necessary for lamin disruption. During HSV infection, U{sub S}3 limited the development of disruptions in the lamina, since cells infected with a U{sub S}3-null virus developed large perforations in the lamin layer. U{sub S}3 regulation of lamin disruption does not correlate with the induction of apoptosis. Expression of either U{sub L}34 or U{sub S}3 proteins alone disrupted lamin A/C and lamin B localization. Expression of U{sub L}34 and U{sub S}3 together had little effect on lamin A/C localization, suggesting a regulatory interaction between the two proteins. The data presented in this paper argue for crucial roles for both U{sub L}34 and U{sub S}3 in regulating the state of the nuclear lamina during viral infection.

Bjerke, Susan L. [Department of Microbiology, The University of Iowa, 3115 Medical Laboratories, Iowa City, IA 52242 (United States); Roller, Richard J. [Department of Microbiology, The University of Iowa, 3115 Medical Laboratories, Iowa City, IA 52242 (United States)]. E-mail: richard-roller@uiowa.edu

2006-04-10

383

The Invasive Species Forecasting System: A Space-Based Decision Support Infrastructure for Managing Biological Invasions  

NASA Astrophysics Data System (ADS)

The spread of invasive species is one of the most daunting environmental, economic, and human-health problems facing the United States and the World today. It is one of several grand challenge environmental problems being addressed by NASA's Science Mission Directorate through a national application partnership with the US Geological Survey. NASA and USGS are working together to develop a National Invasive Species Forecasting System (ISFS) for the management and control of invasive species on Department of Interior and adjacent lands. As part of this effort, we are using NASA's EOS Clearing House (ECHO) framework to create an Invasive Species Data Service (ISDS). The ISDS will be a networked service that integrates a suite of NASA remote sensing data providers with the ecological field data resources of the National Biological Information Infrastructure (NBII). Aggregated ISDS data will feed directly into ISFS analysis routines to produce landscape-scale predictive maps of species distributions. ISDS and the ECHO framework thus provide an efficient interface between existing NASA data systems and decision support systems that are the province of federal agencies and other national organizations. The effort significantly broadens the use of NASA data in managing the Nation's invasive species threat. In this talk, we will describe the NASA/USGS invasive species partnership, provide an overview of the Invasive Species Forecasting System, and show how we are using ECHO technologies as the middle-ware framework for a comprehensive Invasive Species Data Service.

Most, N. N.; Kendig, D.; Wichman, K.; Pollack, N.; Ilagan, A.; Morisette, J. T.; Pedelty, J. A.; Tilmes, C.; Smith, J. A.; Pfister, R.; Schnase, J. L.; Stohgren, T. J.; Crosier, C.; Graham, J.; Newman, G.; Kalkhan, M. A.; Reich, R.

2004-12-01

384

Spatial distribution and performance of native and invasive Ardisia (Myrsinaceae) species in Puerto Rico: the anatomy of an invasion  

Microsoft Academic Search

Comparisons between native and invasive congeners are potentially useful approaches for identifying characteristics that promote\\u000a invasiveness. Those traits for which an invasive exhibits superior ecological performance are likely to contribute to its\\u000a invasiveness. We tested the hypothesis that invasive tree species have better ecological performance in early life cycle stages\\u000a than native species in forests where they coexist. We studied

Marcia C. MunozJames; James D. Ackerman

2011-01-01

385

The difference in miR-21 expression levels between invasive and non-invasive breast cancers emphasizes its role in breast cancer invasion.  

PubMed

MicroRNA-21 (miR-21) overexpression is characteristic for various types of tumors, but it is still unknown whether its expression levels differ between invasive and non-invasive breast carcinomas. The main goal of the study was to determine the difference in miR-21 expression among normal tissue, non-invasive, invasive with non-invasive component, and pure invasive breast cancer samples, to explain its potential role and significance in breast cancer invasiveness. The second goal was to propose miR-21 as molecular marker of breast cancer invasiveness and potential target for future anti-miR therapies for the prevention of invasion and metastasis. In order to reveal the role of miR-21 in breast cancer invasiveness, we measured miR-21 expression levels in 44 breast cancer and four normal samples by stem-loop real-time RT-PCR using TaqMan technology. Relative expression levels of miR-21 were significantly higher in invasive than in other groups (P=0.002) and significantly higher in invasive compared with invasive with non-invasive component group in histological (P=0.043) and nuclear grade 2 (P=0.036), estrogen-receptor-positive (ER+) (P=0.006), progesterone-receptor-positive (PR+) (P=0.008), ER+PR+ (P=0.007), and proliferation index (Ki-67)?20% (P=0.036) tumors. Our findings suggest that miR-21 could be independent molecular marker of breast cancer invasiveness and potential target for future anti-miR therapies for the prevention of invasion and metastasis. PMID:24488617

Petrovi?, Nina; Manduši?, Vesna; Stanojevi?, Boban; Luki?, Silvana; Todorovi?, Lidija; Roganovi?, Jelena; Dimitrijevi?, Bogomir

2014-03-01

386

Connexins, gap junctions and tissue invasion.  

PubMed

Formation of metastases negatively impacts the survival prognosis of cancer patients. Globally, if the various steps involved in their formation are relatively well identified, the molecular mechanisms responsible for the emergence of invasive cancer cells are still incompletely resolved. Elucidating what are the mechanisms that allow cancer cells to evade from the tumor is a crucial point since it is the first step of the metastatic potential of a solid tumor. In order to be invasive, cancer cells have to undergo transformations such as down-regulation of cell-cell adhesions, modification of cell-matrix adhesions and acquisition of proteolytic properties. These transformations are accompanied by the capacity to "activate" stromal cells, which may favor the motility of the invasive cells through the extracellular matrix. Since modulation of gap junctional intercellular communication is known to be involved in cancer, we were interested to consider whether these different transformations necessary for the acquisition of invasive phenotype are related with gap junctions and their structural proteins, the connexins. In this review, emerging roles of connexins and gap junctions in the process of tissue invasion are proposed. PMID:24457198

Defamie, Norah; Chepied, Amandine; Mesnil, Marc

2014-04-17

387

Factors promoting marine invasions: A chemoecological approach  

PubMed Central

The Mediterranean Sea is losing its biological distinctiveness, and the same phenomenon is occurring in other seas. It gives urgency to a better understanding of the factors that affect marine biological invasions. A chemoecological approach is proposed here to define biotic conditions that promote biological invasions in terms of enemy escape and resource opportunities. Research has focused on the secondary metabolite composition of three exotic sea slugs found in Greece that have most probably entered the Mediterranean basin by Lessepsian migration, an exchange that contributes significantly to Mediterranean biodiversity. We have found toxic compounds with significant activity as feeding deterrents both in the cephalaspidean Haminoea cyanomarginata and in the nudibranch Melibe viridis. These findings led us to propose aposematism in the former and dietary autonomy in producing defensive metabolites in the latter case, as predisposing factors to the migration. In the third mollusk investigated, the anaspidean Syphonota geographica, the topic of marine invasions has been approached through a study of its feeding biology. The identification of the same compounds from both the viscera of each individual, separately analyzed, and their food, the seagrass Halophila stipulacea, implies a dietary dependency. The survival of S. geographica in the Mediterranean seems to be related to the presence of H. stipulacea. The initial invasion of this exotic pest would seem to have paved the way for the subsequent invasion of a trophic specialist that takes advantage of niche opportunities.

Mollo, Ernesto; Gavagnin, Margherita; Carbone, Marianna; Castelluccio, Francesco; Pozone, Ferdinando; Roussis, Vassilios; Templado, Jose; Ghiselin, Michael T.; Cimino, Guido

2008-01-01

388

Epithelial-mesenchymal Transition and Cell Invasion  

PubMed Central

Epithelial-mesenchymal transition (EMT) is a complex process in which epithelial cells acquire the characteristics of invasive mesenchymal cells. EMT has been implicated in cancer progression and metastasis as well as the formation of many tissues and organs during development. Epithelial cells undergoing EMT lose cell-cell adhesion structures and polarity, and rearrange their cytoskeletons. Several oncogenic pathways such as transforming growth factor (TGF) -?, Wnt, and Notch signaling pathways, have been shown to induce EMT. These pathways have activated transcription factors including Snail, Slug, and the ZEB family which work as transcriptional repressors of E-cadherin, thereby making epithelial cells motile and resistant to apoptosis. Mounting evidence shows that EMT is associated with cell invasion and tumor progression.In this review, we summarize the characteristic features of EMT, pathways leading to EMT, and the role of EMT in cell invasion. Three topics are addressed in this review: (1) Definition of EMT, (2) Signaling pathways leading to EMT, (3) Role of EMT in cell invasion. Understanding the role of EMT in cell invasion will provide valuable information for establishing strategies to develop anti-metastatic therapeutics which modulate malignant cellular processes mediated by EMT.

Son, Hwajin

2010-01-01

389

Endemic predators, invasive prey and native diversity  

PubMed Central

Interactions between native diversity and invasive species can be more complex than is currently understood. Invasive ant species often substantially reduce diversity in the native ants diversity that act as natural control agents for pest insects. In Indonesia (on the island of Sulawesi), the third largest cacao producer worldwide, we show that a predatory endemic toad (Ingerophrynus celebensis) controls invasive ant (Anoplolepis gracilipes) abundance, and positively affects native ant diversity. We call this the invasive-naivety effect (an opposite of enemy release), whereby alien species may not harbour anti-predatory defences against a novel native predator. A positive effect of the toads on native ants may facilitate their predation on insect vectors of cacao diseases. Hence, toads may increase crop yield, but further research is needed on this aspect. Ironically, amphibians are globally the most threatened vertebrate class and are strongly impacted by the conversion of rainforest to cacao plantations in Sulawesi. It is, therefore, crucial to manage cacao plantations to maintain these endemic toads, as they may provide critical ecosystem services, such as invasion resistance and preservation of native insect diversity.

Wanger, Thomas C.; Wielgoss, Arno C.; Motzke, Iris; Clough, Yann; Brook, Barry W.; Sodhi, Navjot S.; Tscharntke, Teja

2011-01-01

390

Cancer stem cell contribution to glioblastoma invasiveness  

PubMed Central

Glioblastoma (GBM) is the most aggressive and lethal brain tumor in adults. Its invasive nature currently represents the most challenging hurdle to surgical resection. The mechanism adopted by GBM cells to carry out their invasive strategy is an intricate program that recalls what takes place in embryonic cells during development and in carcinoma cells during metastasis formation, the so-called epithelial-to-mesenchymal transition. GBM cells undergo a series of molecular and conformational changes shifting the tumor toward mesenchymal traits, including extracellular matrix remodeling, cytoskeletal re-patterning, and stem-like trait acquisition. A deeper understanding of the mechanisms driving the whole infiltrative process represents the first step toward successful treatment of this pathology. Here, we review recent findings demonstrating the invasive nature of GBM cancer stem cells, together with novel candidate molecules associated with both cancer stem cell biology and GBM invasion, like doublecortin and microRNAs. These findings may affect the design of effective therapies currently not considered for GBM invasive progression.

2013-01-01

391

Comparison of non-invasive and invasive blood pressure in aeromedical care.  

PubMed

Blood pressure measurement is an essential physiological measurement for all critically ill patients. Previous work has shown that non-invasive blood pressure is not an accurate reflection of invasive blood pressure measurement. In a transport environment, the effects of motion and vibration may make non-invasive blood pressure less accurate. Consecutive critically ill patients transported by a dedicated aeromedical retrieval and critical care transfer service with simultaneous invasive and non-invasive blood pressure measurements were analysed. Two sets of measurements were recorded, first in a hospital environment before departure (pre-flight) and a second during aeromedical transport (in-flight). A total of 56 complete sets of data were analysed. Bland-Altman plots showed limits of agreement (precision) for pre-flight systolic blood pressure were -37.3?mmHg to 30.0?mmHg, and for pre-flight mean arterial pressure -20.5?mmHg to 25.0?mmHg. The limits of agreement for in-flight systolic blood pressure were -40.6?mmHg to 33.1?mmHg, while those for in-flight mean blood pressure in-flight were -23.6?mmHg to 24.6?mmHg. The bias for the four conditions ranged from 0.5 to -3.8 mmHg. There were no significant differences in values between pre-flight and in-flight blood pressure measurements for all categories of blood pressure measurement. Thus, our data show that non-invasive blood pressure is not a precise reflection of invasive intra-arterial blood pressure. Mean blood pressure measured non-invasively may be a better marker of invasive blood pressure than systolic blood pressure. Our data show no evidence of non-invasive blood pressures being less accurate in an aeromedical transport environment. PMID:23033983

McMahon, N; Hogg, L A; Corfield, A R; Exton, A D

2012-12-01

392

Choroidal invasion of retinoblastoma: metastatic potential and clinical risk factors.  

PubMed Central

There is considerable debate about the significance of choroidal invasion of retinoblastoma with regard to metastatic disease. The charts of patients with retinoblastoma were reviewed over a 17 year period to determine the frequency of histopathological choroidal invasion of retinoblastoma and its risk for eventual metastatic disease. Sixty seven of 289 eyes (23%) enucleated for retinoblastoma had histopathological evidence of choroidal invasion. Those patients with choroidal invasion (with or without optic nerve invasion) were more likely to develop metastases than those without choroidal invasion (p = 0.0001). When considering those patients with isolated choroidal invasion of retinoblastoma, excluding those with associated optic nerve invasion, there was no significant risk but there was a trend towards the development of metastases (p = 0.10). The clinical factors found to be predictive for choroidal invasion from retinoblastoma from a univariate analysis included increased intraocular pressure (p = 0.04) and iris neovascularisation (p = 0.007) and, from a multivariate analysis, iris neovascularisation (p = 0.02). The histopathological factors statistically associated with choroidal invasion included the presence of optic nerve invasion (p = 0.002) and poorly differentiated retinoblastoma (p = 0.003). Factors not predictive for choroidal invasion included the age, race, and sex of the patient and the tumour laterality, inheritance, size, and growth pattern. Choroidal invasion of retinoblastoma is a risk for metastases, especially if it is associated with any degree of optic nerve invasion. Images

Shields, C. L.; Shields, J. A.; Baez, K. A.; Cater, J.; De Potter, P. V.

1993-01-01

393

Arthropod invasion disrupts Cycas micronesica seedling recruitment.  

PubMed

We recently described characteristics of reproductive effort for the cycad Cycas micronesica on the island of Guam. The data were serendipitously recorded just prior to the devastating invasion of the armored scale Aulacaspis yasumatsui. This invasion decimated the cycad population and after six years of infestation no recruitment is occurring among the survivors. We describe various underlying mechanisms that may explain how this homopteran insect has eliminated host recruitment among categories including plant-pollinator mutualism disruptions, direct damage to reproductive structures, population level responses to declining plant health, and failures of seedlings to establish. Our pre-invasion data on reproductive effort will serve as the benchmark for quantifying how this alien pest is endangering the endemic cycad. PMID:22446554

Marler, Thomas E; Terry, L Irene

2011-11-01

394

Minimally Invasive Surgical Therapies for Atrial Fibrillation  

PubMed Central

Atrial fibrillation is the most common sustained arrhythmia and is associated with significant risks of thromboembolism, stroke, congestive heart failure, and death. There have been major advances in the management of atrial fibrillation including pharmacologic therapies, antithrombotic therapies, and ablation techniques. Surgery for atrial fibrillation, including both concomitant and stand-alone interventions, is an effective therapy to restore sinus rhythm. Minimally invasive surgical ablation is an emerging field that aims for the superior results of the traditional Cox-Maze procedure through a less invasive operation with lower morbidity, quicker recovery, and improved patient satisfaction. These novel techniques utilize endoscopic or minithoracotomy approaches with various energy sources to achieve electrical isolation of the pulmonary veins in addition to other ablation lines. We review advancements in minimally invasive techniques for atrial fibrillation surgery, including management of the left atrial appendage.

Nakamura, Yoshitsugu; Kiaii, Bob; Chu, Michael W. A.

2012-01-01

395

Invasive Plant Atlas of New England  

NSDL National Science Digital Library

Many persons have grown increasingly concerned about various invasive species, and despite the scientific debates about what constitutes such a species, ecologists and others will find this site quite helpful. Drawing on support from the USDA, this project was developed by the Ecology and Evolutionary Biology Department of the University of Connecticut, the New England Wildflower Society, and several other participating organizations. This site includes a Web-accessible atlas that contains images and descriptive information for the invasive and potentially invasive plants in New England. Visitors can create their customized maps that document these species by utilizing the online records database, and also just search the species by geographic species. As a way of introduction, visitors can also browse a current list of species for which data has been collected thus far. Persons interested in volunteering for the project may also want to take a look at the volunteers section which lists the times of upcoming training sessions.

396

Modeling tumor invasion and metastasis in Drosophila  

PubMed Central

Conservation of major signaling pathways between humans and flies has made Drosophila a useful model organism for cancer research. Our understanding of the mechanisms regulating cell growth, differentiation and development has been considerably advanced by studies in Drosophila. Several recent high profile studies have examined the processes constraining the metastatic growth of tumor cells in fruit fly models. Cell invasion can be studied in the context of an in vivo setting in flies, enabling the genetic requirements of the microenvironment of tumor cells undergoing metastasis to be analyzed. This Perspective discusses the strengths and limitations of Drosophila models of cancer invasion and the unique tools that have enabled these studies. It also highlights several recent reports that together make a strong case for Drosophila as a system with the potential for both testing novel concepts in tumor progression and cell invasion, and for uncovering players in metastasis.

Miles, Wayne O.; Dyson, Nicholas J.; Walker, James A.

2011-01-01

397

Non-invasive markers for hepatic fibrosis.  

PubMed

With great advancements in the therapeutic modalities used for the treatment of chronic liver diseases, the accurate assessment of liver fibrosis is a vital need for successful individualized management of disease activity in patients. The lack of accurate, reproducible and easily applied methods for fibrosis assessment has been the major limitation in both the clinical management and for research in liver diseases. However, the problem of the development of biomarkers capable of non-invasive staging of fibrosis in the liver is difficult due to the fact that the process of fibrogenesis is a component of the normal healing response to injury, invasion by pathogens, and many other etiologic factors. Current non-invasive methods range from serum biomarker assays to advanced imaging techniques such as transient elastography and magnetic resonance imaging (MRI). Among non-invasive methods that gain strongest clinical foothold are FibroScan elastometry and serum-based APRI and FibroTest. There are many other tests that are not yet widely validated, but are none the less, promising. The rate of adoption of non-invasive diagnostic tests for liver fibrosis differs from country to country, but remains limited. At the present time, use of non-invasive procedures could be recommended as pre-screening that may allow physicians to narrow down the patients' population before definitive testing of liver fibrosis by biopsy of the liver. This review provides a systematic overview of these techniques, as well as both direct and indirect biomarkers based approaches used to stage fibrosis and covers recent developments in this rapidly advancing area. PMID:21849046

Baranova, Ancha; Lal, Priyanka; Birerdinc, Aybike; Younossi, Zobair M

2011-01-01

398

Non-Invasive markers for hepatic fibrosis  

PubMed Central

With great advancements in the therapeutic modalities used for the treatment of chronic liver diseases, the accurate assessment of liver fibrosis is a vital need for successful individualized management of disease activity in patients. The lack of accurate, reproducible and easily applied methods for fibrosis assessment has been the major limitation in both the clinical management and for research in liver diseases. However, the problem of the development of biomarkers capable of non-invasive staging of fibrosis in the liver is difficult due to the fact that the process of fibrogenesis is a component of the normal healing response to injury, invasion by pathogens, and many other etiologic factors. Current non-invasive methods range from serum biomarker assays to advanced imaging techniques such as transient elastography and magnetic resonance imaging (MRI). Among non-invasive methods that gain strongest clinical foothold are FibroScan elastometry and serum-based APRI and FibroTest. There are many other tests that are not yet widely validated, but are none the less, promising. The rate of adoption of non-invasive diagnostic tests for liver fibrosis differs from country to country, but remains limited. At the present time, use of non-invasive procedures could be recommended as pre-screening that may allow physicians to narrow down the patients' population before definitive testing of liver fibrosis by biopsy of the liver. This review provides a systematic overview of these techniques, as well as both direct and indirect biomarkers based approaches used to stage fibrosis and covers recent developments in this rapidly advancing area.

2011-01-01

399

[Non invasive ventilation in emergency settings].  

PubMed

The use of non invasive ventilation (NIV) in the emergency setting to treat acute respiratory failure (ARF) has received much attention. To date, large studies support the early administration of continuous positive airway pressure (CPAP) in patients with cardiogenic acute pulmonary edema; and 2) non-invasive positive pressure ventilation (NPPV) for exacerbations of chronic obstructive pulmonary disease (COPD). NIV could also be useful in other types of ARF, but its success rate is dependent on the cause of ARF and patient's characteristics. Use of NIV in the emergency setting should take into account validated indications and local expertise of the nursing staff to minimize the risk of complications. PMID:16152879

Sarasin, F P; Jolliet, P

2005-08-10

400

Asiatic clam invasion: causes and effects  

SciTech Connect

The recent introduction and subsequent invasion of the Asiatic clam has offered a new problem of infestation in power plant intake systems that conventional intermittent chlorination procedures may not resolve. These clam invasions adversely affect intake systems and irrigation works by clogging the systems and causing erosion of pipes. Heated power plant discharges were found to be a source of thermal enrichment for the clams. Methods of temperature control followed by chlorination appear to offer short-term solutions; harvesting of the clams for protein and calcium contents present an additional solution.

Cherry, D.S.; Cairns, J.; Graney, R.L.

1980-01-01

401

Directed Cell Invasion and Migration During Metastasis  

PubMed Central

Metastasis requires tumor cell dissemination to different organs from the primary tumor. Dissemination is a complex cell motility phenomenon that requires the molecular coordination of the protrusion, chemotaxis, invasion and contractility activities of tumor cells to achieve directed cell migration. Recent studies of the spatial and temporal activities of the small GTPases have begun to elucidate how this coordination is achieved. The direct visualization of the pathways involved in actin polymerization, invasion and directed migration in dissemination competent tumor cells will help identify the molecular basis of dissemination and allow the design and testing of more specific and selective drugs to block metastasis.

Bravo-Cordero, Jose Javier; Hodgson, Louis; Condeelis, John

2011-01-01

402

Percutaneous & Mini Invasive Achilles tendon repair  

PubMed Central

Rupture of the Achilles tendon is a considerable cause of morbidity with reduced function following injury. Recent studies have shown little difference in outcome between the techniques of open and non-operative treatment using an early active rehabilitation programme. Meta-analyses have shown that non-operative management has increased risk of re-rupture whereas surgical intervention has risks of complications related to the wound and iatrogenic nerve injury. Minimally invasive surgery has been adopted as a way of reducing infections rates and wound breakdown however avoiding iatrogenic nerve injury must be considered. We discuss the techniques and outcomes of percutaneous and minimally invasive repairs of the Achilles tendon.

2011-01-01

403

Non-invasive imaging of nerve regeneration  

PubMed Central

The need for non-invasive imaging of peripheral nerves that can reliably assess extent of nerve fiber degeneration and regeneration is increasingly realized. Availability of such a technology has several immediate clinical and preclinical applications. Diffusion tensor imaging (DTI) is an emerging magnetic resonance based technology that is particularly suited for imaging nerve fiber tracts. This review highlights immediate clinical and preclinical uses of non-invasive imaging of peripheral nerve regeneration and DTI as a potential technology that can fulfill these clinical and research needs.

Sheikh, Kazim A.

2009-01-01

404

[Minimal invasive approach to renal cancer].  

PubMed

In the last decade minimally invasive surgery for renal cell carcinoma has been performed in order to decrease perioperative morbidity, reduce the period of hospitalization, and to preserve renal tissue. Minimal invasive techniques include laparoscopic partial nephrectomy and in situ ablation of the lesion by different forms of energy such as cryoablation, radio frequency ablation, ultrasound, microwave, laser and photon energy. Long term results are not yet available, however, the early oncological and functional outcomes are promising. This article presents an updated review on the experience gained with the different approaches to treat renal cell carcinoma, the indications, the advantages, disadvantages, and the possible complications. PMID:15931899

Hidas, Guy; Shental, Joseph; Nativ, Ofer

2005-05-01