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1.
J Cutan Pathol ; 34(1): 65-70, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17214858

ABSTRACT

BACKGROUND: Linear unilateral basal cell nevus represents a linear collection of macules and papules histologically similar to basal cell carcinoma but with benign clinical behavior. We describe a patient who initially presented at the age of 6 months with a unilateral linear basal cell nevus on the right flank. The differential diagnosis included the nevoid basal cell carcinoma syndrome. Constitutional PTCH mutations are causative of the nevoid basal cell carcinoma syndrome, and somatic PTCH mutations are found in the vast majority of basal cell carcinomas. Somatic SMO mutations have also been found in some basal cell carcinomas. METHODS: Histologic examination of the lesions is performed. Short tandem-repeat molecular analysis at the PTCH locus and sequencing of PTCH and SMO genes is performed. RESULTS: Histologic examination revealed features initially indistinguishable from basal cell carcinoma. Short tandem-repeat DNA analysis did not reveal loss of heterozygosity at the PTCH locus. DNA sequencing of both the PTCH and the SMO genes from the patient's lesions revealed neither inactivating mutations of PTCH nor activating mutations of SMO. CONCLUSION: Molecular examination indicates that the PTCH and SMO genes are not involved in the pathogenesis of the patients' congenital linear unilateral basal cell nevus. Furthermore, we discuss the relationship between linear basal cell nevus and basaloid follicular hamartoma.


Subject(s)
Nevus/genetics , Nevus/pathology , Skin Neoplasms/genetics , Skin Neoplasms/pathology , Thigh , DNA, Neoplasm , Diagnosis, Differential , Humans , Infant , Loss of Heterozygosity , Microsatellite Repeats , Mutation , Patched Receptors , Patched-1 Receptor , Receptors, Cell Surface/genetics , Receptors, G-Protein-Coupled/genetics , Skin Neoplasms/congenital , Smoothened Receptor
2.
J Biomed Mater Res ; 52(4): 725-37, 2000 Dec 15.
Article in English | MEDLINE | ID: mdl-11033556

ABSTRACT

Since osteoblast proliferation is critical for bone development, the effect of bone extracellular matrix (ECM) proteins on osteoblast signaling and proliferation in serum-free medium was investigated. Proliferation was highest in primary rat calvarial osteoblasts cells grown on fibronectin but less on type I collagen; osteonectin and poly-L-lysine did not support early proliferation. Fibronectin and type I collagen binding requires integrins, whereas cell adhesion to osteonectin or poly-L-lysine does not involve integrins. Therefore, the role of integrins in osteoblast signaling, leading to the induction of AP-1 transcription factors (c-fos and c-jun) which are important in cell proliferation, was studied. c-fos and c-jun message levels were increased at 60 min in osteoblasts plated onto fibronectin or collagen, but not in cells on osteonectin or poly-L-lysine. Protein synthesis was not required for c-fos mRNA expression; however, kinase activity was necessary for c-fos induction. In cells plated onto fibronectin, c-fos mRNA levels were controlled by protein kinase C and phosphotyrosine kinase signaling pathways. In contrast, c-fos levels in collagen-adhering cells may involve protein kinase A. The signaling pathway involving the phosphorylation of focal adhesion kinase and mitogen-activated kinases was also shown to be transiently increased in osteoblasts on fibronectin and type I collagen, but not in cells on poly-L-lysine. These results demonstrate that osteoblast binding to the extracellular matrix through integrins induces c-fos and c-jun, and that both fibronectin and collagen affect these AP-1 transcription factors through protein kinase-sensitive pathways. Thus, osteoblast proliferation is modulated differentially by specific ECM components.


Subject(s)
Extracellular Matrix/metabolism , Integrins/physiology , Osteoblasts/metabolism , Signal Transduction , Transcription Factor AP-1/physiology , Animals , Antibodies/pharmacology , Cell Culture Techniques/instrumentation , Cell Differentiation , Cell Division , Cells, Cultured , Coated Materials, Biocompatible , Collagen/metabolism , Culture Media, Serum-Free , Enzyme Inhibitors/pharmacology , Extracellular Matrix Proteins/metabolism , Fibronectins/metabolism , Focal Adhesion Kinase 1 , Focal Adhesion Protein-Tyrosine Kinases , Gene Expression Regulation , Genes, fos , Genes, jun , Integrins/immunology , MAP Kinase Signaling System , Nucleic Acid Synthesis Inhibitors/pharmacology , Oligopeptides/pharmacology , Osteoblasts/cytology , Osteoblasts/drug effects , Osteonectin/metabolism , Phosphorylation/drug effects , Plastics , Polylysine/metabolism , Protein Binding , Protein Kinase C/antagonists & inhibitors , Protein Processing, Post-Translational/drug effects , Protein Synthesis Inhibitors/pharmacology , Protein-Tyrosine Kinases/physiology , RNA, Messenger/biosynthesis , Rats , Thrombospondins/metabolism , Transcription Factor AP-1/biosynthesis , Transcription Factor AP-1/genetics
3.
Ther Apher ; 3(1): 20-4, 1999 Feb.
Article in English | MEDLINE | ID: mdl-10079801

ABSTRACT

Endeavors to optimize the management of thrombotic thrombocytopenic purpura (TTP) syndrome and improve mortality and relapse rates are hindered by its poorly understood pathophysiology. Variability in the application of therapeutic plasma exchange (TPE), including replacement fluid strategies, desirable endpoints in the platelet count, serum lactate dehydrogenase concentration, and the use of a TPE taper, limit comparisons among published studies. The diversity of adjunctive therapies such as antiplatelet agents, steroids, and splenectomy further clouds comparisons. Recent progress in the diagnosis, pathophysiology, and management of TTP syndrome are summarized. The possible role of occult infection and newly emerging associations such as ticlopidine therapy are discussed. Advances in possible pathogenic mechanisms, the rationale for different replacement fluids including the recently licensed solvent-detergent treated plasma, and progress in the apheresis management of TTP syndrome are presented.


Subject(s)
Blood Component Removal , Purpura, Thrombotic Thrombocytopenic/therapy , Humans , Purpura, Thrombotic Thrombocytopenic/diagnosis , Purpura, Thrombotic Thrombocytopenic/etiology , Purpura, Thrombotic Thrombocytopenic/physiopathology , Recurrence
4.
Calcif Tissue Int ; 62(1): 74-82, 1998 Jan.
Article in English | MEDLINE | ID: mdl-9405737

ABSTRACT

The in vivo expression of fibronectin, type I collagen, and several non-collagenous proteins was correlated with the development of bone in fetal and early neonatal rat calvariae. Fibronectin was the earliest matrix protein expressed in calvariae, with a peak expression in fetal 16- and 17-day (d) bones. Fibronectin expression coincided with the condensation of preosteoblasts prior to calcification and decreased once bone mineralization commenced. The expression of type I collagen, osteonectin, bone sialoprotein, and alkaline phosphatase mRNAs was found at 17 d. The increase in type I collagen mRNA levels was correlated with a 3.5-fold increase in calcium deposition at 19-20 d. Bone sialoprotein and alkaline phosphatase peaked on fetal 21 d while osteonectin remained at a low level and was localized to the osteoblast layer and the osteocyte lacunae. Osteopontin mRNA levels increased rapidly in neonatal calvariae. After birth, osteonectin and fibronectin were mainly associated with blood vessels. Thus, fibronectin is one of the earliest matrix proteins expressed in calvariae and is rapidly followed by type I collagen, bone sialoprotein, and alkaline phosphatase. Osteocalcin, osteonectin, and osteopontin mRNAs have similar patterns of expression in the developing fetal calvaria, and their synthesis coincided with mineralization.


Subject(s)
Bone Development/genetics , Bone Development/physiology , Calcification, Physiologic/physiology , Extracellular Matrix Proteins/genetics , Animals , Animals, Newborn , Bone Density/physiology , Calcium/metabolism , Fetus/anatomy & histology , Fetus/physiology , Fluorescent Antibody Technique , Gene Expression , Gestational Age , In Situ Hybridization , RNA, Messenger/analysis , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Skull/anatomy & histology , Skull/physiology , Time Factors
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