Feline Cystic Thymoma: A Clinicopathologic, Immunohistologic, and Electron Microscopic Study of 14 Cases

2003 ◽  
Vol 5 (1) ◽  
pp. 27-35 ◽  
Author(s):  
AK Patnaik ◽  
PH Lieberman ◽  
RA Erlandson ◽  
C Antonescu
Keyword(s):  
Electron Microscopy ◽  
Smooth Muscle ◽  
Epithelial Cells ◽  
Smooth Muscle Actin ◽  
Muscle Actin ◽  
Electron Microscopic ◽  
Germinal Centres ◽  
Factor Viii Antigen ◽  
Cell Components ◽  
Microscopic Features

Cystic thymoma was diagnosed in 14 cats in a period of 6 years. The most common clinical sign was laboured breathing. The tumours were characterized by various-sized cystic spaces with central vessels. The epithelial cells varied from oval to spindle to polygonal cells enclosing cystic spaces or in pure epithelial cell components. The nuclei of the neoplastic cells had scattered chromatin and small nucleoli. The cytoplasm was pale eosinophilic. The concentration of mature lymphocytes varied from area to area with rare germinal centres. Immunohistochemically, the epithelial cells stained only with AE1/AE3. The central vessels were positive for vimentin, smooth muscle actin, and factor VIII antigen. Electron microscopy revealed that the cyst walls were lined by epithelial cells that were joined by desmosomes, and the walls were well separated from the cystic spaces by a well-defined basement membrane. The neoplastic epithelial cells contained scattered tonofilaments. Three of the cats had metastasis to the lymph nodes and lungs. Two novel cases of ectopic cystic thymoma have also been described. Results of this study reveal that cystic thymoma is uncommon in cats, and that the histomorphologic, immunohistochemical, and electron microscopic features are similar to those of cystic thymoma in humans.

MKL1 mediates TGF-β1-induced α-smooth muscle actin expression in human renal epithelial cells

2008 ◽  
Vol 294 (5) ◽  
pp. F1116-F1128 ◽  
Author(s):  
Gerard Elberg ◽  
Lijuan Chen ◽  
Dorit Elberg ◽  
Michael D. Chan ◽  
Charlotte J. Logan ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Epithelial Cells ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Primary Cultures ◽  
Muscle Actin ◽  
Mesenchymal Transition ◽  
Endogenous Expression ◽  
Tgf Β1 ◽  
Stimulation Of

Transforming growth factor-β1 (TGF-β1) is known to induce epithelial-mesenchymal transition in the kidney, a process involved in tubulointerstitial fibrosis. We hypothesized that a coactivator of the serum response factor (SRF), megakaryoblastic leukemia factor-1 (MKL1), stimulates α-smooth muscle actin (α-SMA) transcription in primary cultures of renal tubular epithelial cells (RTC), which convert into myofibroblasts on treatment with TGF-β1. Herein, we study the effect of MKL1 expression on α-SMA in these cells. We demonstrate that TGF-β1 stimulation of α-SMA transcription is mediated through CC(A/T)6-rich GG elements known to bind to SRF. These elements also mediate the MKL1 effect that dramatically activates α-SMA transcription in serum-free media. MKL1 fused to green fluorescent protein localizes to the nucleus and induces α-SMA expression regardless of treatment with TGF-β1. Using proteasome inhibitors, we also demonstrate that the proteolytic ubiquitin pathway regulates MKL1 expression. These data indicate that MKL1 overexpression is sufficient to induce α-SMA expression. Inhibition of endogenous expression of MKL1 by small interfering RNA abolishes TGF-β1 stimulation of α-SMA expression. Therefore, MKL1 is also absolutely required for TGF-β1 stimulation of α-SMA expression. Western blot and immunofluorescence analysis show that overexpressed and endogenous MKL1 are located in the nucleus in non-stimulated RTC. Chromatin immunoprecipitation assay demonstrates that TGF-β1 induces binding of endogenous SRF and MKL1 to the α-SMA promoter in chromatin. Since MKL1 constitutes a potent factor regulating α-SMA expression, modulation of endogenous MKL1 expression or activity may have a profound effect on myofibroblast formation and function in the kidney.

scholarly journals Presence of alpha smooth muscle actin in lens epithelial cells of aphakic rabbit eyes.

1996 ◽  
Vol 80 (10) ◽  
pp. 906-910 ◽  
Author(s):  
D Kurosaka ◽  
K Kato ◽  
T Nagamoto
Keyword(s):  
Smooth Muscle ◽  
Epithelial Cells ◽  
Smooth Muscle Actin ◽  
Lens Epithelial Cells ◽  
Muscle Actin ◽  
Alpha Smooth Muscle Actin

Immunohistochemical Staining Characteristics of Canine Gastrointestinal Stromal Tumors

1997 ◽  
Vol 34 (4) ◽  
pp. 303-311 ◽  
Author(s):  
R. G. LaRock ◽  
P. E. Ginn
Keyword(s):  
Smooth Muscle ◽  
Small Intestine ◽  
Immunohistochemical Staining ◽  
Gastrointestinal Stromal Tumors ◽  
Smooth Muscle Actin ◽  
Muscle Actin ◽  
Stromal Tumors ◽  
S 100 ◽  
Microscopic Features ◽  
Microscopic Diagnosis

Sections from 35 formalin-fixed, paraffin-embedded, canine gastrointestinal stromal tumors consisting of 14 leiomyomas (five stomach, three small intestine, two colon, four rectum), 18 leiomyosarcomas (one stomach, five small intestine, nine cecum, three rectum), two undifferentiated sarcomas (two stomach), and one neurofibrosarcoma (small intestine) were examined for the expression of vimentin, S-100 protein, α-smooth muscle actin, and desmin via immunoperoxidase methodology using an avidin-biotin complex technique. The leiomyomas were 4/14 (29%) vimentin-positive, 3/14 (21%) S-100 protein-positive, 10/14 (71%) α-smooth muscle actin-positive and 13/14 (93%) desmin-positive. Leiomyosarcomas were 18/18 (100%) vimentin-positive, 11/18 (61%) S-100 protein-positive, 9/18 (50%) α-smooth muscle actin-positive, and 15/18 (83%) desmin-positive. The undifferentiated sarcomas were 2/2 (100%) vimentin-positive, 2/2 (100%) S-100 protein-positive, 1/2 (50%) α-smooth muscle actin-positive, and 0/2 (0%) desmin-positive. The neurofibrosarcoma was vimentin and S-100 protein-positive and α-smooth muscle actin- and desmin-negative. Thirty-one of thirty-five (89%) of all neoplasms demonstrated reactivity for either desmin and/or α-smooth muscle actin. S-100 protein reactivity occurred in 17/35 (49%) of all specimens. Lack of desmin and α-smooth muscle actin reactivity occurred in 4/35 (11%) of all specimens, all of which were vimentin-positive. The immunohistochemical results indicate that the majority of canine gastrointestinal stromal tumors (GIST) with light microscopic features of smooth muscle cells have immunohistochemical staining patterns supporting smooth muscle differentiation. Vimentin reactivity correlated with a light microscopic diagnosis of malignancy. The lack of smooth muscle cell markers in some tumors and the high percentage of cases positive for S-100 protein may suggest a more complex histogenesis or differentiation for subgroups of these tumors.

Extracellular matrixes influence a-smooth muscle actin expression in cultured porcine lens epithelial cells

1999 ◽  
Vol 19 (3) ◽  
pp. 260-263 ◽  
Author(s):  
Daijiro Kurosaka ◽  
Katsuhiko Kato ◽  
Takeshi Oshima ◽  
Hiroyo Kurosaka ◽  
Mami Yoshino ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Epithelial Cells ◽  
Smooth Muscle Actin ◽  
Lens Epithelial Cells ◽  
Muscle Actin ◽  
Actin Expression

TGF-β2 increases α-smooth muscle actin expression in bovine retinal pigment epithelial cells

1996 ◽  
Vol 15 (11) ◽  
pp. 1144-1147 ◽  
Author(s):  
Daijiro Kurosaka ◽  
Yasuhide Muraki ◽  
Makoto Inoue ◽  
Hiroshi Katsura
Keyword(s):  
Smooth Muscle ◽  
Epithelial Cells ◽  
Retinal Pigment Epithelial ◽  
Smooth Muscle Actin ◽  
Retinal Pigment ◽  
Retinal Pigment Epithelial Cells ◽  
Muscle Actin ◽  
Pigment Epithelial ◽  
Actin Expression ◽  
Pigment Epithelial Cells

Immunohistologic study of interleukin-1, transforming growth factor-β, and α-smooth muscle actin in lens epithelial cells in diabetic eyes

2005 ◽  
Vol 31 (11) ◽  
pp. 2187-2192 ◽  
Author(s):  
Yoshie Hayashi ◽  
Satoshi Kato ◽  
Toshine Maeda ◽  
Tadayoshi Kaiya ◽  
Shigehiko Kitano
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Epithelial Cells ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Interleukin 1 ◽  
Transforming Growth Factor Β ◽  
Lens Epithelial Cells ◽  
Muscle Actin

Glomangiomyoma (Glomus Tumor) of the Kidney

2005 ◽  
Vol 129 (9) ◽  
pp. 1172-1174 ◽  
Author(s):  
Noman H. Siddiqui ◽  
Agnieszka Rogalska ◽  
Indu S. Basil
Keyword(s):  
Electron Microscopy ◽  
Smooth Muscle ◽  
Glomus Tumor ◽  
Smooth Muscle Actin ◽  
Muscle Actin ◽  
Thin Filaments ◽  
Glomus Tumors ◽  
Computed Tomographic ◽  
Dense Bodies ◽  
Computed Tomographic Scan

Abstract We report herein a case of glomus tumor arising in the kidney of a 55-year-old woman, which was found incidentally on a computed tomographic scan. Partial nephrectomy revealed a 2-cm encapsulated mass that was architecturally similar to glomus tumor. Immunohistochemistry showed positivity of tumor cells for vimentin and smooth muscle actin. On electron microscopy, cytoplasmic thin filaments and dense bodies were seen, confirming the smooth muscle nature of the tumor. Glomus tumors arising in visceral organs are rare, and those arising in kidney are exceedingly rare.

Appearance of myofibroblast during the healing of experimental corneal wound

1993 ◽  
Vol 51 ◽  
pp. 386-387
Author(s):  
Masamichi Ishizaki ◽  
Kyoko Wakamatsu ◽  
Takakuni Matsunami ◽  
Nobuaki Yamanaka ◽  
Toshikazu Saiga ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Smooth Muscle ◽  
Stromal Cells ◽  
Smooth Muscle Actin ◽  
Corneal Stroma ◽  
Uranyl Acetate ◽  
Muscle Actin ◽  
Thin Sections ◽  
Corneal Wound ◽  
Fibroblastic Cells

It is well known that corneal stroma cells (keratocytes) can transform to fibroblasts during the corneal wound healing. We have studied the expression of α-smooth muscle actin, vimentin and desmin in fibroblastic cells of the alkali-burneo and lacerated corneas in the rabbits by means of immunohistochemistry and electron microscopy.Methods. Rabbits were anesthetized, and central corneal alkali-burn and laceration were produced. The injured corneas healed for 1 day to 45 days, and 18 days embryonic rabbit corneas were immunostained with monoclonal antibodies against α-smooth muscle actin, vimentin and desmin. For transmission electron microscopy, two techniques were used for the staining of ultra-thin sections: 1) uranyl acetate and Reynold's lead citrate and 2) the tannic acid method of Kajikawa.Results. Antibody against α-smooth muscle actin reacted with fibroblastic cells in injured corneas (Fig 1) but not with stromal cells in normal and embryonic corneas. Antivimentin antibody strongly reacted with the fibroblastic cells in injured corneas (Fig 2) and stromal cells in normal and embryonic corneas.

scholarly journals α-Smooth muscle actin is constitutively expressed in the lens epithelial cells of several species

2006 ◽  
Vol 83 (4) ◽  
pp. 999-1001 ◽  
Author(s):  
Claudia M. Garcia ◽  
Gina P. Kwon ◽  
David C. Beebe
Keyword(s):  
Smooth Muscle ◽  
Epithelial Cells ◽  
Smooth Muscle Actin ◽  
Lens Epithelial Cells ◽  
Muscle Actin

Intranodal Palisaded Myofibroblastoma

2007 ◽  
Vol 131 (2) ◽  
pp. 306-310 ◽  
Author(s):  
Thong Nguyen ◽  
Mahmoud A. Eltorky
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Actin ◽  
Muscle Actin ◽  
Ki 67 ◽  
Female Ratio ◽  
Male Female Ratio ◽  
Microscopic Features ◽  
Intranodal Palisaded Myofibroblastoma ◽  
Slow Growing ◽  
Cut Surface

Abstract Intranodal palisaded myofibroblastoma (IPM) usually presents as a painless, slow-growing inguinal mass. Our review of 42 cases from 13 publications indicates that two thirds of IPMs occur between the ages of 45 and 55 years, the male-female ratio is 2:1, and there is a lack of ethnic predilection. Grossly, the IPM cut surface shows areas of hemorrhage. Five microscopic features are seen: (a) compressed remnants of lymphoid tissue at the periphery; (b) spindle cells with nuclear palisading; (c) intraparenchymal hemorrhage and erythrocyte extravasation; (d) so-called amianthoid fibers; and (e) intracellular and extracellular fuchsinophilic bodies that stain positive for smooth muscle actin. Immunohistochemically, IPM is positive for smooth muscle actin and cyclin D1 and negative for S100, glial fibrillary acidic protein, CD34, and desmin, and it shows a low proliferative index of Ki-67. Electron microscopy demonstrates features of myofibroblasts and smooth muscle cells. Excellent prognosis is seen after surgical treatment, with an approximately 6% recurrence rate and no malignant transformation.

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