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1.
Oper Dent ; 43(6): E280-E287, 2018.
Article in English | MEDLINE | ID: mdl-30106334

ABSTRACT

This study investigated the effects of irradiance and exposure duration on dual-cured resin cements irradiated through ceramic restorative materials. A single light-curing unit was calibrated to three different irradiances (500, 1000, and 1500 mW/cm2) and irradiated to three different attenuating materials (transparent acryl, lithium disilicate, zirconia) with 1-mm thicknesses for 20 or 60 seconds. The changes in irradiance and temperature were measured with a radiometer (or digital thermometer) under the attenuating materials. The degree of conversion (DC) of dual-cure resin cement after irradiation at different irradiances and exposure durations was measured with Fourier transform near infrared spectroscopy. Two-way analysis of variance revealed that irradiance ( p<0.001) and exposure duration ( p<0.001) significantly affected temperature and DC. All groups showed higher DCs with increased exposure times ( p<0.05), but there were no statistically significant differences between the groups irradiated with 1000 mW/cm2 and 1500 mW/cm2 ( p>0.05). Higher-intensity irradiances yielded higher temperatures ( p<0.05), but exposure time did not affect temperature when materials were irradiated at 500 mW/cm2 ( p>0.05).


Subject(s)
Ceramics/chemistry , Light-Curing of Dental Adhesives/methods , Resin Cements/chemistry , Calibration , Curing Lights, Dental , Dental Materials/chemistry , Dental Porcelain , Materials Testing , Spectroscopy, Fourier Transform Infrared , Temperature , Zirconium
2.
Proc Natl Acad Sci U S A ; 114(47): 12460-12465, 2017 11 21.
Article in English | MEDLINE | ID: mdl-29109267

ABSTRACT

Psoriasis is a chronic inflammatory skin disease characterized by the infiltration of T cell and other immune cells to the skin in response to injury or autoantigens. Conventional, as well as unconventional, γδ T cells are recruited to the dermis and epidermis by CCL20 and other chemokines. Together with its receptor CCR6, CCL20 plays a critical role in the development of psoriasiform dermatitis in mouse models. We screened a panel of CCL20 variants designed to form dimers stabilized by intermolecular disulfide bonds. A single-atom substitution yielded a CCL20 variant (CCL20 S64C) that acted as a partial agonist for the chemokine receptor CCR6. CCL20 S64C bound CCR6 and induced intracellular calcium release, consistent with G-protein activation, but exhibited minimal chemotactic activity. Instead, CCL20 S64C inhibited CCR6-mediated T cell migration with nominal impact on other chemokine receptor signaling. When given in an IL-23-dependent mouse model for psoriasis, CCL20 S64C prevented psoriatic inflammation and the up-regulation of IL-17A and IL-22. Our results validate CCR6 as a tractable therapeutic target for psoriasis and demonstrate the value of CCL20 S64C as a lead compound.


Subject(s)
Chemokine CCL20/genetics , Dermatitis/therapy , Mutagenesis, Site-Directed/methods , Psoriasis/therapy , Receptors, CCR6/metabolism , Animals , Biological Therapy/methods , COS Cells , Chemokine CCL20/immunology , Chemokine CCL20/metabolism , Chlorocebus aethiops , Crystallography, X-Ray , Dermatitis/immunology , Disease Models, Animal , Epidermis/immunology , Epidermis/metabolism , Humans , Interleukin-23/immunology , Mice , Psoriasis/immunology , Receptors, CCR6/immunology , T-Lymphocytes/immunology
3.
Oncogenesis ; 1: e9, 2012 May 07.
Article in English | MEDLINE | ID: mdl-23552640

ABSTRACT

The expression of the CC chemokine receptor-7 (CCR7) by cancers, including melanoma, augments lymph node (LN) metastasis, but little is known about its role in lymphangiogenesis and anti-tumor immunity. We injected control B16 murine melanoma cells (pLNCX2-B16) and CCR7-overexpressing B16 cells (CCR7-B16) in murine footpads and compared resulting tumors at the protein and mRNA level using immunostaining, Affymetrix gene microarray and quantitative reverse-transcriptase PCR. Although control and CCR7-B16 primary tumors were of similar size, LN metastasis was dramatically enhanced in CCR7-B16 tumors. Microarray analysis of leukocyte-depleted pLNCX2-B16 and CCR7-B16 tumor cell suspensions showed that three major groups of genes linked to interferon (IFN)-γ signaling pathways (for example, STAT1, CXCR 9-11, CCL5 and CXCL10, major histocompatibility complex (MHC) I and MHC II) were downregulated in the CCR7-B16 tumor microenvironment, suggesting activation through CCR7 can downregulate pathways critical for host anti-tumor immunity. In addition, mRNA expression of the lymphatic marker podoplanin was upregulated in CCR7-B16 tumors by 3.35-fold versus control tumors. Anti-podoplanin monoclonal antibody staining revealed a three-fold increase in intratumoral CCL21-expressing lymphatic vessels, as well as a two-fold increase in the number of invading tumor cells per lymphatic vessel in CCR7-B16 versus control tumors. Enhanced anti-vascular endothelial growth factor C (VEGF-C) staining was present in CCR7-B16 versus control tumors, suggesting that VEGF-C may have a role in the CCR7-mediated lymphangiogenesis. In summary, CCR7-B16 tumors show a striking decrease in IFN-γ-mediated inflammatory gene expression in contrast to increased expression of VEGF-C, CCL21 and podoplanin by lymphatic vessels. Enhanced lymphangiogenesis may contribute to the dramatic increase in LN metastasis that is observed in the CCR7-expressing tumors.

4.
Oral Dis ; 17(6): 550-9, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21306481

ABSTRACT

While treatment for cancer in terms of chemotherapy and radiation therapy have evolved significantly since their inception, both of these cancer treatment modalities, especially if used in combination (e.g., as with head and neck cancers), have a very real potential to result in painful and debilitating adverse effects that clearly decrease quality of life and, potentially, increase mortality due to cancer. Herein, we discuss the prevalence and etiology of three broad categories of oral complications found during the treatment of cancer patients: mucositis, dysgeusia, and infectious disease. Lastly, we present therapeutic options that may be helpful in ameliorating these uncomfortable and, sometimes, life-threatening oral complications.


Subject(s)
Head and Neck Neoplasms/therapy , Mouth Diseases/etiology , Antineoplastic Agents/adverse effects , Candidiasis, Oral/etiology , Dysgeusia/etiology , Herpesviridae Infections/etiology , Humans , Immunocompromised Host , Mouth Diseases/therapy , Opportunistic Infections/etiology , Radiation Injuries/etiology , Stomatitis/etiology
5.
Intern Med J ; 40(6): 437-42, 2010 Jun.
Article in English | MEDLINE | ID: mdl-19460054

ABSTRACT

BACKGROUND: It is unknown whether microalbuminuria is associated with non-alcoholic fatty liver disease (NAFLD) among patients with prediabetes and type 2 diabetes mellitus (DM). This study investigated the association of NAFLD with microalbuminuria among patients with prediabetes and diabetes. METHODS: We evaluated 1361 subjects who had an abnormal oral glucose tolerance test (OGTT) on routine screening. All participants were divided into two groups, prediabetes and newly diagnosed type 2 DM, and the association of NAFLD with metabolic parameters on microalbuminuria was analysed. RESULTS: The patients with NAFLD had higher prevalence rates of microalbuminuria (6.3% vs 19%; P = 0.001 in prediabetes, 4.5% vs 32.6%; P < 0.001 in diabetes) and also had a greater albumin-to-creatinine ratio (14.6 +/- 52.0 microg/mg Cr vs 27.7 +/- 63.9 microg/mg Cr; P = 0.051 in prediabetes, 11.4 +/- 21.4 microg/mg Cr vs 44.7 +/- 76.4 microg/mg Cr; P < 0.001 in diabetes) than those without NAFLD. The logistic regression analysis showed that NAFLD was associated with increased rates of microalbuminuria (odds ratio 3.66; 95%confidence interval (CI) 1.31-10.20, P = 0.013 in prediabetes, odds ratio 5.47;95% CI 1.01-29.61, P = 0.048 in diabetes), independently of age, sex, body mass index, waist circumference, liver enzymes, lipid profiles, HbA1c, insulin resistance as estimated by homeostasis model assessment, hypertension,smoking status and the metabolic syndrome. CONCLUSIONS: The results of our study revealed a strong relationship between microalbuminuria and NAFLD in the patients with prediabetes and newly diagnosed diabetes. Further studies are required to confirm whether NAFLD is a predictor of the development of microalbuminuria in patients with prediabetes and diabetes.


Subject(s)
Albuminuria/epidemiology , Diabetes Mellitus, Type 2/epidemiology , Fatty Liver/epidemiology , Prediabetic State/epidemiology , Adult , Albuminuria/diagnosis , Albuminuria/etiology , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/diagnosis , Fatty Liver/complications , Fatty Liver/diagnosis , Female , Glucose Tolerance Test/methods , Humans , Male , Middle Aged , Prediabetic State/complications , Prediabetic State/diagnosis
6.
Br J Dermatol ; 157(5): 946-53, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17854367

ABSTRACT

BACKGROUND: Serum proteomic analysis is an analytical technique utilizing high-throughput mass spectrometry (MS) in order to assay thousands of serum proteins simultaneously. The resultant 'proteomic signature' has been used to differentiate benign and malignant diseases, enable disease prognosis, and monitor response to therapy. OBJECTIVES: This pilot study was designed to determine if serum protein patterns could be used to distinguish patients with tumour-stage mycosis fungoides (MF) from patients with a benign inflammatory skin condition (psoriasis) and/or subjects with healthy skin. METHODS: Serum was analysed from 45 patients with tumour-stage MF, 56 patients with psoriasis, and 47 controls using two MS platforms of differing resolution. An artificial intelligence-based classification model was constructed to predict the presence of the disease state based on the serum proteomic signature. RESULTS: Based on data from an independent testing set (14-16 subjects in each group), MF was distinguished from psoriasis with 78.6% (or 78.6%) sensitivity and 86.7% (or 93.8%) specificity, while sera from patients with psoriasis were distinguished from those of nonaffected controls with 86.7% (or 93.8%) sensitivity and 75.0% (or 76.9%) specificity (depending on the MS platform used). MF was distinguished from unaffected controls with 61.5% (or 71.4%) sensitivity and 91.7% (or 92.9%) specificity. In addition, a secondary survival analysis using 11 MS peaks identified significant survival differences between two MF groups (all P-values <0.05). CONCLUSIONS: Serum proteomics should be further investigated for its potential to identify patients with neoplastic skin disease and its ability to determine disease prognosis.


Subject(s)
Blood Proteins/chemistry , Mycosis Fungoides/blood , Psoriasis/blood , Skin Neoplasms/blood , Adult , Aged , Aged, 80 and over , Case-Control Studies , Female , Humans , Male , Middle Aged , Mycosis Fungoides/diagnosis , Pilot Projects , Proteomics/methods , Psoriasis/diagnosis , Sensitivity and Specificity , Skin Neoplasms/diagnosis
7.
Hong Kong Med J ; 11(6): 503-6, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16340028

ABSTRACT

Initial presentation of a malignant disease as recurrent attacks of lower limb ischaemia due to emboli from a mural thrombus in the descending thoracic aorta is extremely rare. A diagnosis of malignancy may thus easily be overlooked. Recent advances in imaging technology have made the diagnosis of thoracic aortic mural thrombi much easier. Occult malignancy should always be suspected in the absence of biochemical evidence of hypercoagulability. We report on a patient with underlying malignant disease who presented with lower limb ischaemia that was relieved by axillobifemoral bypass.


Subject(s)
Aorta, Abdominal/diagnostic imaging , Aorta, Thoracic/surgery , Femoral Artery/surgery , Neoplasms, Unknown Primary/complications , Thrombosis/etiology , Aorta, Thoracic/diagnostic imaging , Axillary Artery/surgery , Blood Vessel Prosthesis , Femoral Artery/diagnostic imaging , Humans , Ischemia/etiology , Leg/blood supply , Male , Middle Aged , Radiography , Recurrence , Vascular Surgical Procedures
8.
J Natl Cancer Inst ; 93(21): 1638-43, 2001 Nov 07.
Article in English | MEDLINE | ID: mdl-11698568

ABSTRACT

BACKGROUND: CC chemokine receptor-7 (CCR7), which plays a critical role in the migration of activated dendritic cells to regional lymph nodes via afferent lymphatic vessels, is also expressed by human breast and melanoma cell lines. Because neoplastic cells also enter lymphatic vessels before metastasis to the lymph nodes, we investigated whether CCR7 expression enhances metastasis of B16 murine melanoma cells to regional lymph nodes. METHODS: B16 cells were transduced with a retroviral vector containing CCR7 complementary DNA (CCR7-B16 cells) or with vector alone (pLNCX2-B16 control cells). The functional assay for CCR7 protein was Ca(2+) flux stimulated by the chemokine CCL21, a CCR7-specific ligand produced by lymphatic endothelial cells. B16 tumor cells were injected into the footpad of mice. Tumor cell metastasis to draining lymph nodes was assessed by measuring messenger RNA (mRNA) for tyrosinase-related protein-1 (TRP), a melanocyte-specific enzyme, with real-time, quantitative reverse transcription-coupled polymerase chain reaction. All statistical tests were two-sided. RESULTS: One week after injection into the footpad, 701-fold (95% confidence interval [CI] = 64- to 1336-fold) more TRP mRNA was detected in draining lymph nodes from CCR7-B16 cell-injected mice than in those from control cell-injected mice. Three weeks after footpad injection, 58% (11 of 19) of the draining lymph nodes from CCR7-B16 cell-injected mice and 5% (one of 19) of those from control mice showed gross metastases (P<.001). CCR7-B16 cells isolated from lymph node metastases retained functional CCR7 expression. Lymph node metastasis of CCR7-B16 cells was blocked by neutralizing anti-CCL21 antibodies (metastasis in none of five lymph nodes) but not by control immunoglobulin G (three of five). Enhanced metastasis of CCR7-B16 cells was specific for a lymphatic route because both CCR7-B16 and control cells co-injected intravenously metastasized to the lung at the same frequency. CONCLUSION: Expression of a single chemokine receptor gene, CCR7, increased B16 cell metastasis to draining lymph nodes, suggesting that cancer cells may co-opt normal mechanisms of lymph node homing during metastasis.


Subject(s)
Lymphatic Metastasis , Melanoma, Experimental/pathology , Receptors, Chemokine/physiology , Animals , Chemokine CCL21 , Chemokines, CC/physiology , Mice , Mice, Inbred C57BL , Receptors, CCR7 , Receptors, Chemokine/genetics , Tumor Cells, Cultured
9.
J Immunol ; 167(9): 4791-5, 2001 Nov 01.
Article in English | MEDLINE | ID: mdl-11673480

ABSTRACT

The binding of a T cell to an Ag-laden dendritic cell (DC) is a critical step of the acquired immune response. Herein, we address whether a DC-produced chemokine can induce the arrest of T cells on DC under dynamic flow conditions. Ag-primed T cells and a T cell line were observed to rapidly ( approximately 0.5 s) bind to immobilized DC at low shear stress (0.1-0.2 dynes/cm(2)) in a pertussis toxin-sensitive fashion. Quantitatively, Ag-primed T cells displayed 2- to 3-fold enhanced binding to DC compared with unprimed T cells (p < 0.01). In contrast to naive T cells, primed T cell arrest was largely inhibited by pertussis toxin, neutralization of the CC chemokine, macrophage-derived chemokine (CCL22), or by desensitization of the CCL22 receptor, CCR4. Our results demonstrate that DC-derived CCL22 induces rapid binding of activated T cells under dynamic conditions and that Ag-primed and naive T cells fundamentally differ with respect to chemokine-dependent binding to DC.


Subject(s)
Dendritic Cells/physiology , Receptors, Chemokine/physiology , T-Lymphocytes/physiology , Animals , CD40 Antigens/physiology , Cell Communication , Cell Line , Chemokine CCL22 , Chemokines, CC/pharmacology , Mice , Mice, Inbred BALB C , Receptors, CCR4
10.
Exp Biol Med (Maywood) ; 226(7): 674-80, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11444103

ABSTRACT

The apical sodium-dependent bile acid cotransporter (ASBT) and the ileal bile acid binding protein (IBABP) are two components of ileal bile acid absorption. During the third postnatal week of the rat, there is a dramatic increase in ASBT and IBABP expression. The goals of this study were to examine the role of hormones on the ontogenic expression of ASBT mRNA and the role of weaning for both ASBT and IBABP mRNA. Administration of various doses of dexamethasone during the second postnatal week induced ASBT mRNA levels, and this effect was significantly increased with concomitant thyroxine treatment. Early weaning and weaning prevention were utilized to investigate the influence of dietary factors. ASBT and IBABP mRNA levels were significantly elevated by early weaning and were decreased by weaning prevention compared with littermate controls. Thus, glucocorticoids and thyroxine appear to play a role in the ontogenic expression of ASBT mRNA and weaning appears to participate in both ASBT and IBABP expression.


Subject(s)
Bile Acids and Salts/metabolism , Carrier Proteins/genetics , Gene Expression Regulation, Developmental , Growth , Hydroxysteroid Dehydrogenases , Ileum/metabolism , Intestinal Absorption , Membrane Glycoproteins , Animals , Dexamethasone/pharmacology , Gene Expression Regulation, Developmental/drug effects , Glucocorticoids/pharmacology , RNA, Messenger/analysis , Rats , Rats, Sprague-Dawley , Thyroxine/pharmacology , Weaning
11.
J Invest Dermatol ; 116(3): 466-70, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11231324

ABSTRACT

Although aberrations in adhesion molecule expression by lymphoma cells have been reported, the functional consequences of these changes are unclear. Herein, we report a patient with Sézary syndrome whose malignant peripheral blood T cells were TCRVbeta17+. Malignant T cell adhesion molecule abnormalities included an 80% downregulation of LFA-1 compared with normal controls and no detectable expression of alpha4 integrin. Under shear stress conditions, malignant T cells failed to arrest on recombinant ICAM-1 in the presence of chemokines and displayed an 80% decrease in the ability to arrest on TNF-alpha activated dermal microvascular endothelial cells compared with normal CD4+ memory T cells. Cutaneous lymphocyte-associated antigen expression was detected in approximately 25% of malignant T cells in the peripheral blood, but was substantially less than this in TCRVbeta17+ T cells in the dermis. By contrast, > 95% of malignant T cells in peripheral blood expressed L-selectin (CD62L), and L-selectin ligand was detected in dermal blood vessels at affected skin sites. Compared with normal CD4+, malignant T cells attached and rolled 6-fold more efficiently on L-selectin ligand (p < 0.0001). Thus, despite aberrant expression of LFA-1 and functional defects in the ability to arrest on activated endothelial cells, malignant T cells in this patient entered skin and produced significant clinical disease. We propose a mechanism by which the upregulated expression of L-selectin and L-selectin ligands may partially compensate for altered LFA-1 function.


Subject(s)
Cell Adhesion Molecules/metabolism , Sezary Syndrome/metabolism , Skin Neoplasms/metabolism , Aged , CD18 Antigens/metabolism , Cell Adhesion , Endothelium, Vascular/cytology , Endothelium, Vascular/metabolism , Female , Humans , Intercellular Adhesion Molecule-1/pharmacology , L-Selectin/metabolism , Ligands , Lymphocyte Function-Associated Antigen-1/metabolism , Microcirculation , Receptors, Chemokine/metabolism , Recombinant Proteins/pharmacology , Sezary Syndrome/pathology , Sezary Syndrome/physiopathology , Skin/blood supply , Skin Neoplasms/pathology , Skin Neoplasms/physiopathology , Stress, Mechanical , T-Lymphocytes/physiology
12.
Adv Dermatol ; 17: 211-41, 2001.
Article in English | MEDLINE | ID: mdl-11758117

ABSTRACT

Although many individual components of the lymphocyte's migratory machinery have been identified and analyzed for function in vitro, interesting questions remain regarding the in vivo integration of these components. How does the lymphocyte "choose" a direction for migration in the complex cytokine/chemokine environment of inflamed dermis when multiple chemokines secreted by multiple cell types are present? Can differences in chemokine expression explain the clinical and histologic differences seen in different inflammatory skin disease? What are the roles of proteins such as VAP-1? Our present understanding of lymphocyte migration has already led to the use of monoclonal antibodies to integrins such as LFA-1 that can potentially be of therapeutic use in skin diseases such as psoriasis. Small molecule inhibitors of T lymphocyte-specific receptors such as CCR4 or CXCR3 are promising agents for controlling T cell-mediated inflammation but have yet to be developed. These receptors may have greater selective expression on skin-homing T cells and thus may decrease the risk of iatrogenic immunosuppression. Close cooperation between the pharmaceutical industry and basic scientists will hopefully lead to the evolution of such compounds and toward more effective treatment of inflammatory skin diseases.


Subject(s)
Receptors, Lymphocyte Homing/immunology , Skin Diseases/immunology , Skin/immunology , T-Lymphocytes/physiology , Antibodies, Monoclonal/physiology , Apoptosis Regulatory Proteins , Cell Movement/physiology , Dermatitis, Atopic/immunology , Endothelium, Vascular/physiology , Humans , Integrins/physiology , Lymphoma, T-Cell, Cutaneous/immunology , Metalloendopeptidases/physiology , Psoriasis/immunology , Psoriasis/therapy , Receptors, Chemokine/immunology , Receptors, Cytokine/immunology , Skin Diseases/therapy , Skin Neoplasms/immunology
13.
J Immunol ; 165(12): 6677-81, 2000 Dec 15.
Article in English | MEDLINE | ID: mdl-11120783

ABSTRACT

Memory T cells (mTC) express multiple chemokine receptors (including CCR4 and CCR6) that may potentially be involved in their arrest on inflamed endothelia. Herein, we specifically addressed whether CCR6 is required for mTC to arrest on TNF-alpha-activated human dermal microvascular endothelial cells (HDMEC) in vitro under shear stress conditions. Recombinant liver and activation-regulated chemokine (LARC)/CCL20 (a CCR6 ligand) induced firm arrest of cutaneous lymphocyte Ag(+) mTC in a flow chamber system using purified substrates. Strikingly, desensitization of CCR6 with LARC, but not thymus and activation-regulated chemokine/CCL17 or secondary lymphoid tissue chemokine/CCL21, caused a 50-75% decrease (p < 0. 001) in arrest of mTC on HDMEC, which was indistinguishable from the reduction observed when total mTC were treated with pertussis toxin (p > 0.5). CCR6-depleted mTC also had a markedly reduced ability to arrest on HDMEC. Our results suggest that LARC production by activated endothelial cells and CCR6 expression by mTC may be critical components in the pertussis toxin-sensitive arrest of mTC on activated HDMEC.


Subject(s)
Cell Movement/immunology , Endothelium, Vascular/immunology , Endothelium, Vascular/metabolism , Immunologic Memory , Macrophage Inflammatory Proteins , Receptors, Chemokine/physiology , Skin/blood supply , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , Cell Adhesion/immunology , Cell Communication/immunology , Cells, Cultured , Chemokine CCL20 , Chemokines/biosynthesis , Chemokines, CC/physiology , Endothelium, Vascular/cytology , Endothelium, Vascular/pathology , Humans , Receptors, CCR6 , Receptors, Chemokine/biosynthesis , Stress, Mechanical , T-Lymphocyte Subsets/pathology
14.
Eur J Immunol ; 30(10): 2808-14, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11069061

ABSTRACT

Chemokine receptors on dendritic cells (DC) and chemokines within lymph nodes (LN) contribute to trafficking of DC to appropriate sites within the LN. Here we show that DC that have migrated out of skin ex vivo (migratory DC, migDC) express 50-fold more CXCR5 mRNA than fresh Langerhans cells and migrate in response to B lymphocyte chemoattractant (BLC) in vitro. When injected into the footpad of mice, migDC emigrate to regional LN where up to 40% are found in B cell zones. By contrast, murine bone marrow-derived DC display 14-fold less CXCR5, do not migrate to BLC in vitro, and migrate strictly to T cell zones in LN. We propose that activated skin DC utilize CXCR5 and BLC as a possible mechanism to home to B cell zones of LN, where they may have direct effects on B cells.


Subject(s)
B-Lymphocytes/cytology , Chemokines, CXC/pharmacology , Chemotaxis/drug effects , Dendritic Cells/immunology , Lymph Nodes/cytology , Receptors, Cytokine/metabolism , Skin/cytology , Animals , B-Lymphocytes/immunology , Cell Communication , Chemokine CXCL13 , Dendritic Cells/chemistry , Female , Lymph Nodes/ultrastructure , Mice , Mice, Inbred BALB C , Receptors, CXCR5 , Receptors, Chemokine , Skin/immunology , Specific Pathogen-Free Organisms , T-Lymphocytes/cytology
15.
Eur J Immunol ; 30(8): 2355-61, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10940926

ABSTRACT

Mast cells (MC) are anatomically located near nerves and blood vessels in skin and the gastrointestinal tract and tend to localize within certain cutaneous tumors such as neurofibromas. However, the molecular mechanisms by which MC home to these sites are not well characterized. Fractalkine (FK) is a membrane-bound CX3C chemokine that displays constitutive expression in dendritic cells as well as in non-hematopoietic tissues including mammalian brain. Here we show that FK is constitutively expressed by skin endothelial cells, dermal dendrocytes and cells within neurofibromas. By reverse transcription-PCR, FK receptor, CX3CR1, is expressed by cultured murine bone marrow-derived MC (BMMC) of both connective tissue and mucosal phenotypes. Non-activated human dermal MC isolated from neonatal foreskin similarly demonstrated CX3CR1 expression. In chemotaxis assays, FK attracted MC with maximal migration occurring between 25 - 125 ng / ml. BMMC were not stimulated to release proinflammatory mediators in the presence of FK as measured by granule-associated beta-hexosaminidase release. Thus, CX3CR1 is expressed by MC and effectively mediates chemotaxis without inducing degranulation. We propose that the constitutive expression of FK on certain cells in the skin may be a factor in the tissue-specific homing of MC.


Subject(s)
Cell Degranulation , Chemokines, CX3C , Chemokines, CXC/physiology , Mast Cells/physiology , Membrane Proteins/physiology , Skin/cytology , Animals , CX3C Chemokine Receptor 1 , Cell Adhesion , Chemokine CX3CL1 , Chemokines, CXC/analysis , Chemotaxis , Female , Humans , Membrane Proteins/analysis , Mice , Mice, Inbred BALB C , RNA, Messenger/analysis , Receptors, Cytokine/genetics , Receptors, HIV/genetics
16.
Am J Physiol Regul Integr Comp Physiol ; 278(6): R1555-63, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10848523

ABSTRACT

Ileal bile acid binding protein (IBABP) is a cytosolic protein believed to be involved in the absorption of conjugated bile acids. In rodents this protein and its mRNA have been shown to increase markedly during the third postnatal week. Because this period of ontogeny is characterized by increasing circulating concentrations of glucocorticoids and thyroxine, the goal of our study was to investigate the role of these hormones in IBABP expression in the developing rat. Administration of various doses of dexamethasone (Dex) during the second postnatal week caused a robust induction of IBABP mRNA and protein. Plateau levels of IBABP mRNA occurred at a Dex dose of 0.1 microg/g body wt, which is within the physiological range. IBABP mRNA was not appreciably induced until 24 h after treatment, suggesting that glucocorticoids influence IBABP either through a delayed primary or a secondary response mechanism. The regional pattern of IBABP mRNA elicited by Dex mimicked that seen during normal development, with appearance in distal ileum preceding proximal ileum. Thyroxine injections did not result in a significant increase of IBABP mRNA, and synergism between Dex and thyroxine was not observed. Taken together, our data suggest that maturation of IBABP expression is influenced by glucocorticoids but not by thyroxine.


Subject(s)
Bile Acids and Salts/metabolism , Carrier Proteins/genetics , Carrier Proteins/metabolism , Glucocorticoids/physiology , Ileum/metabolism , Organic Anion Transporters, Sodium-Dependent , Symporters , Age Factors , Animals , Animals, Suckling , Dexamethasone/pharmacology , Gene Expression Regulation, Developmental/drug effects , Gene Expression Regulation, Developmental/physiology , Glucocorticoids/pharmacology , Ileum/growth & development , Microvilli/metabolism , RNA, Messenger/analysis , Rats , Rats, Sprague-Dawley , Thyroxine/pharmacology
17.
Eur J Immunol ; 29(8): 2551-9, 1999 08.
Article in English | MEDLINE | ID: mdl-10458770

ABSTRACT

The lone CX3C chemokine, fractalkine (FK), is expressed in a membrane-bound form on activated endothelial cells and mediates attachment and firm adhesion of T cells, monocytes and NK cells. We now show that FK is associated with dendritic cells (DC) in epidermis and lymphoid organs. In normal human skin, dual-color fluorescence microscopy co-localized FK expression with Langerhans cells expressing CD1a. In tonsil, FK-positive DC expressed CD83, a marker for mature DC. Human and murine cultured DC up-regulated FK mRNA expression with maturation. Furthermore, CD40 ligation, but not TNF-alpha or lipopolysaccharide treatment, of activated, migratory DC that had migrated from skin explants resulted in a 2.5-fold increase of surface expression of FK without significant alterations of expression of CD80, CD86, CD54 or MHC class II. Since FK mediates adhesion of T cells to activated endothelial cells, the increased expression of FK during DC maturation (and particularly by CD40 ligation) may play a role in the ability of T cells and mature DC to form conjugates and engage in cell-cell communication.


Subject(s)
Chemokines, CX3C , Chemokines, CXC/genetics , Chemokines, CXC/metabolism , Dendritic Cells/immunology , Membrane Proteins/genetics , Membrane Proteins/metabolism , Animals , Base Sequence , CD40 Ligand , Cell Adhesion/immunology , Cell Communication/immunology , Cell Differentiation/immunology , Cell Line , Chemokine CX3CL1 , DNA Primers/genetics , Dendritic Cells/cytology , Humans , Langerhans Cells/immunology , Melanocytes/immunology , Membrane Glycoproteins/pharmacology , Mice , Mice, Inbred BALB C , Palatine Tonsil/cytology , Palatine Tonsil/immunology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Skin/cytology , Skin/immunology , T-Lymphocytes/cytology , T-Lymphocytes/immunology , Tumor Necrosis Factor-alpha/pharmacology , Up-Regulation
18.
J Immunol ; 162(5): 2472-5, 1999 Mar 01.
Article in English | MEDLINE | ID: mdl-10072485

ABSTRACT

Dendritic cells (DCs) emigrate to regional lymph nodes (LNs) during immune responses via afferent lymphatic channels. Secondary lymphoid-tissue chemokine (SLC), a CC chemokine, is expressed in secondary lymphoid organs and mediates the chemotaxis of lymphocytes and DCs via its receptor, CC chemokine receptor 7 (CCR7). By dual-label fluorescence confocal microscopy, we showed MHC class II-positive cells within SLC-staining lymphatic channels in the mouse dermis. SLC was a potent in vitro chemoattractant for cultured, migratory skin DCs, and it enhanced the emigration of MHC class II-positive DCs from mouse skin explants by an average of 2.5-fold. Mature or cytokine-activated, but not resting, Langerhans cells expressed CCR7 mRNA by RT-PCR. Anti-SLC Abs, but not control or anti-eotaxin Abs, blocked the in vivo migration of 51Cr-labeled, skin-derived DCs from footpads to draining LNs by 50% (n = 9, p < 0. 005). Thus, we provide direct evidence that SLC and CCR7 participate in the emigration of DCs from peripheral tissue to LNs via lymphatics.


Subject(s)
Chemokines, CC/physiology , Dendritic Cells/physiology , Lymph Nodes/immunology , Receptors, Chemokine/physiology , Skin/immunology , Animals , Cell Movement , Chemokine CCL21 , Female , Mice , Mice, Inbred BALB C , Receptors, CCR7 , Tumor Necrosis Factor-alpha/pharmacology
19.
J Immunol ; 159(7): 3498-507, 1997 Oct 01.
Article in English | MEDLINE | ID: mdl-9317149

ABSTRACT

Lymphocyte recirculation is dependent on families of adhesion molecules expressed on lymphocytes and their sequential interaction with ligands expressed on high endothelial venules in secondary lymphoid organs such as peripheral lymph nodes. By binding its carbohydrate-based ligands, L-selectin initiates this cascade of molecular interactions, supporting the rolling of lymphocytes along high endothelial venules. Subsequent activation of lymphocyte integrins leads to cell arrest followed by lymphocyte extravasation. Here, we demonstrate stimulated adhesion of PBL and Jurkat T cells to immobilized fibronectin following treatment with (1) GlyCAM-1, a physiologic ligand for L-selectin, and (2) cross-linked anti-L-selectin mAbs. We also utilize a solution binding assay to detect early changes in integrin activity, including affinity modulation and/or integrin clustering, and distinguish these from later postreceptor binding events such as changes in cell shape and spreading. With the Jurkat cell line, GlyCAM-1 and fucoidin (an L-selectin ligand mimetic) induce the binding of soluble fibronectin. In contrast, stimulation through the Jurkat TCR fails to promote binding to soluble ligand even though TCR cross-linking markedly enhances adhesion to immobilized fibronectin. These data suggest that L-selectin and the TCR promote adhesion through distinct mechanisms. Finally, we demonstrate that beta1 integrins are preferentially activated on naive T cells through the L-selectin pathway. Together with our previous studies showing similar activation of beta2 integrins on the naive T cell subset, these data suggest that signals delivered though L-selectin participate in the preferential recruitment of these cells to peripheral lymph nodes.


Subject(s)
Fibronectins/metabolism , Integrin beta1/metabolism , L-Selectin/immunology , L-Selectin/metabolism , T-Lymphocyte Subsets/metabolism , Cell Adhesion/drug effects , Cell Adhesion/immunology , Humans , Immunologic Memory/drug effects , Integrin beta1/physiology , Interphase/drug effects , Interphase/immunology , Jurkat Cells , Models, Biological , Mucins/pharmacology , Polysaccharides/pharmacology , Protein Binding/drug effects , Protein Binding/immunology , Receptors, Antigen, T-Cell/metabolism , Solubility , T-Lymphocyte Subsets/drug effects , T-Lymphocyte Subsets/physiology , Up-Regulation/drug effects , Up-Regulation/immunology
20.
Hong Kong Med J ; 3(2): 149-152, 1997 Jun.
Article in English | MEDLINE | ID: mdl-11850564

ABSTRACT

We conducted a retrospective review of all patients who had an appendicectomy performed at the Queen Elizabeth Hospital, Hong Kong, from January 1993 through December 1994. The diagnostic accuracy for true appendicitis was 74%. Nine per cent of patients had other pathologies, which also needed exploration. The diagnostic accuracy in female patients was 66%, compared with 82% for male patients (P<0.0001). Female patients aged between 15 to 40 years were diagnosed accurately 62% of the time, which has significantly lower than the rate for other female patients (P=0.016). the overall morbidity and mortality rates were 9.2% and 3%, respectively. Complicated appendicitis had a higher morbidity rate of 21%, compared with 9% for uncomplicated appendicitis (P<0.0001). Results for patients who were operated on the day of admission were compared with those who were operated on the day after admission. No significant difference in diagnostic accuracy (P=0.46), percentage of complicated appendicitis (P=0.7), and morbidity rate (P=0.8) was found.

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