STAT3 is required for the gp130-mediated full activation of the c-myc gene.

The signal transducers and activators of transcription (STAT) family members have been implicated in regulating the growth, differentiation, and death of normal and transformed cells in response to either extracellular stimuli, including cytokines and growth factors, or intracellular tyrosine kinases. c-myc expression is coordinately regulated by multiple signals in these diverse cellular responses. We show that STAT3 mostly mediates the rapid activation of the c-myc gene upon stimulation of the interleukin (IL)-6 receptor or gp130, a signal transducing subunit of the receptor complexes for the IL-6 cytokine family. STAT3 does so most likely by binding to cis-regulatory region(s) of the c-myc gene. We show that STAT3 binds to a region overlapping with the E2F site in the c-myc promoter and this site is critical for the c-myc gene promoter- driven transcriptional activation by IL-6 or gp130 signals. This is the first identification of the linkage between a member of the STAT family and the c-myc gene activation, and also explains how the IL-6 family of cytokines is capable of inducing the expression of the c-myc gene.

Adapted Three-step Restorative Technique: Recovering Dental Substrate Compromised by Complex Erosive Wear in a Young Patient.

CLINICAL RELEVANCE: This article presents the dental restoration of a young female patient complaining of erosive dental wear using a three-step restorative technique, an alternative approach with some novel adjustments. SUMMARY: For successful tooth wear treatment, determining the etiological systemic and local factors is the main priority before deciding on effective and long-term preventive and/or therapeutic restorative approaches. In addition to professional intervention, achieving optimal outcomes requires patients to control their diet and/or gastric issues, thus minimizing the wear process. However, continuous wear constitutes the most challenging scenario, mainly when it affects young patients' dentitions. This article describes the dental restoration of posterior teeth with reestablishment of occlusal vertical dimension before treating the anterior teeth, while educating the patient and providing medical monitoring. The three-step restorative technique seems to be properly applicable in cases of significant dental compromise due mainly to erosive wear and is based on direct procedures, which can assure a reliable and feasible approach.

Using Cross-Polarized Photography as a Guide for Selecting Resin Composite Shade.

The restoration of single discolored maxillary anterior teeth is still a difficult task, as not only shape and surface characterization play an important role in the success of the treatment, but the propagation of light throughout the restorative material does as well. In some cases, small changes in morphology, color, and brightness will be noticeable. These factors are sometimes very tricky, and shade guides alone are difficult to use for color selection. This article proposes a protocol of employing cross-polarization imaging for improving the accuracy of the shade selection of resin composites. The step-by-step technique is presented for the restoration of a single discolored tooth.

The E3 ubiquitin ligase SMURF1 regulates cell-fate specification and outflow tract septation during mammalian heart development.

Smad ubiquitin regulatory factor 1 (SMURF1) is a HECT-type E3 ubiquitin ligase that plays a critical role in vertebrate development by regulating planar cell polarity (PCP) signaling and convergent extension (CE). Here we show that SMURF1 is involved in mammalian heart development. We find that SMURF1 is highly expressed in outflow tract cushion mesenchyme and Smurf1-/- mouse embryos show delayed outflow tract septation. SMURF1 is expressed in smooth muscle cells of the coronary arteries and great vessels. Thickness of the aortic smooth muscle cell layer is reduced in Smurf1-/- mouse embryos. We show that SMURF1 is a negative regulator of cardiomyogenesis and a positive regulator of smooth muscle cell and cardiac fibroblast differentiation, indicating that SMURF1 is important for cell-type specification during heart development. Finally, we provide evidence that SMURF1 localizes at the primary cilium where it may regulate bone morphogenetic protein (BMP) signaling, which controls the initial phase of cardiomyocyte differentiation. In summary, our results demonstrate that SMURF1 is a critical regulator of outflow tract septation and cell-type specification during heart development, and that these effects may in part be mediated via control of cilium-associated BMP signaling.

Role of Gab1 in heart, placenta, and skin development and growth factor- and cytokine-induced extracellular signal-regulated kinase mitogen-activated protein kinase activation.

Gab1 is a member of the Gab/DOS (Daughter of Sevenless) family of adapter molecules, which contain a pleckstrin homology (PH) domain and potential binding sites for SH2 and SH3 domains. Gab1 is tyrosine phosphorylated upon stimulation of various cytokines, growth factors, and antigen receptors in cell lines and interacts with signaling molecules, such as SHP-2 and phosphatidylinositol 3-kinase, although its biological roles have not yet been established. To reveal the functions of Gab1 in vivo, we generated mice lacking Gab1 by gene targeting. Gab1-deficient embryos died in utero and displayed developmental defects in the heart, placenta, and skin, which were similar to phenotypes observed in mice lacking signals of the hepatocyte growth factor/scatter factor, platelet-derived growth factor, and epidermal growth factor pathways. Consistent with these observations, extracellular signal-regulated kinase mitogen-activated protein (ERK MAP) kinases were activated at much lower levels in cells from Gab1-deficient embryos in response to these growth factors or to stimulation of the cytokine receptor gp130. These results indicate that Gab1 is a common player in a broad range of growth factor and cytokine signaling pathways linking ERK MAP kinase activation.

Tissue-specific autoregulation of the stat3 gene and its role in interleukin-6-induced survival signals in T cells.

Signal transducer and activator of transcription 3 (STAT3) mediates signals of various growth factors and cytokines, including interleukin-6 (IL-6). In certain IL-6-responsive cell lines, the stat3 gene is autoregulated by STAT3 through a composite IL-6 response element in its promoter that contains a STAT3-binding element (SBE) and a cyclic AMP-responsive element. To reveal the nature and roles of the stat3 autoregulation in vivo, we generated mice that harbor a mutation in the SBE (stat3(mSBE)). The intact SBE was crucial for IL-6-induced stat3 gene activation in the spleen, especially in the red pulp region, the kidney, and both mature and immature T lymphocytes. The SBE was not required, however, for IL-6-induced stat3 gene activation in hepatocytes. T lymphocytes from the stat3(mSBE/mSBE) mice were more susceptible to apoptosis despite the presence of IL-6 than those from wild-type mice. Consistent with this, IL-6-dependent activation of the Pim-1 and junB genes, direct target genes for STAT3, was attenuated in T lymphocytes of the stat3(mSBE/mSBE) mice. Thus, the tissue-specific autoregulation of the stat3 gene operates in vivo and plays a role in IL-6-induced antiapoptotic signaling in T cells.

Therapeutic usefulness of wild-type p53 gene introduction in a p53-null anaplastic thyroid carcinoma cell line.

Anaplastic thyroid carcinomas very often harbor the mutations in the tumor suppressor gene p53. We have previously shown that wild-type (wt) p53 gene introduction led to cell growth arrest, but not apoptosis, in p53-null anaplastic thyroid carcinoma cells. The present studies were designed to evaluate other therapeutic effects of wt-p53 gene introduction on p53-null thyroid carcinoma cells, as chemo- and radiosensitization and inhibition of angiogenesis have also been described recently as additional therapeutic advantages of wt-p53 gene introduction in tumor cells with p53 mutations. A p53-null anaplastic thyroid carcinoma cell line, FRO, and a FRO subline stably expressing a temperature-sensitive (ts) mutant of p53 (p53Val138), tsFRO, were used. ts-p53 functions as mutant and wt at nonpermissive (37 C) and permissive (32 C) temperatures, respectively. tsFRO showed a prolonged cell doubling time compared to parental FRO when cultured at 32 C, but the cell growth rate was similar between FRO and tsFRO at 37 C. The cytotoxic and clonogenic assays demonstrated that although the sensitivity to three different anticancer agents (cisplatin, 5-fluorocytosine, and doxorubicin) was unaltered, radiosensitivity was enhanced in tsFRO compared to FRO at 32 C. Unexpectedly, in studies on angiogenesis, expression levels of vascular endothelial growth factor (an angiogenic factor) messenger ribonucleic acid were similar between FRO and tsFRO, and thrombospondin-1 (an antiangiogenic factor) messenger ribonucleic acid and protein levels were about 2.5-fold lower in tsFRO than FRO at 32 C, although any difference could not be detected in their ability to inhibit in vitro angiogenesis with the culture medium conditioned by tsFRO and FRO at 32 C. These results suggest that p53-defective thyroid carcinomas may benefit from the combination of p53 gene therapy and radiotherapy. However, further study will be necessary to clarify the pathological significance of thrombospondin-1 in angiogenesis and thyroid tumor growth.

In vitro estrogenicity of resin composites.

Previously, we have reported that sealants incorporating bisphenol A dimethacrylate showed estrogenicity by a reporter gene assay. This study tested the hypothesis that commercial composites, which contain various monomers and additives, exhibit estrogenic activity in vitro. The estrogenic activities of eluates obtained from 24 composites and 18 chemicals identified from the composites tested were examined with the use of the reporter gene assay. Among the 24 composites, 6 products were estrogenic, and among the 18 constituents, 1 photostabilizer, 2-hydroxy-4-methoxy-benzophenone (HMBP), 1 photoinitiator, 2,2-dimethoxy-2-phenyl-acetophenone (DMPA), and 1 inhibitor, 2,6-di-tert-butyl-p-cresol (BHT) had significant estrogenic activity. The concentration of HMBP in 4 estrogenic eluates was greater than the minimum concentration required for estrogenicity, and DMPA was found at a higher level than the minimum estrogenic concentration in the remaining 2 estrogenic specimens. These results suggest that the observed estrogenic activity of 6 composites is associated with the elution of either HMBP or DMPA.

Estrogenicity of fissure sealants and adhesive resins determined by reporter gene assay.

It is controversial whether the dental resinous materials containing 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)phenyl]propane (Bis-GMA), which is synthesized from the estrogenic compound bisphenol A (BPA), include unreacted BPA and/or can mimic the effects of natural steroid hormones. In the present study, the estrogenic activities of 3 fissure sealants and 5 adhesive resins, which were all unpolymerized, were determined by means of a reporter gene assay, and the relevance of the components to the estrogenicity was investigated. Two commercially available sealants were confirmed to have estrogenic activity, although none of the tested materials contained BPA. In contrast, hydrophobic monomer bisphenol A dimethacrylate (BPA-DMA), which is also estrogenic, was found to be included in these estrogenic sealants in an amount greater than the minimum concentration to show estrogenicity. This suggests that the estrogenicity of the two proprietary sealants was associated with BPA-DMA rather than with BPA.

Treatment of thyroid carcinoma cells with four different suicide gene/prodrug combinations in vitro.

To develop a suitable suicide gene/prodrug therapy for the treatment of thyroid carcinomas, the relative therapeutic efficacy of four different suicide gene/prodrug combinations was compared in thyroid carcinomas in vitro. Herpes simplex virus thymidine kinase and ganciclovir (HSV-TK/GCV), Escherichia coli cytosine deaminase and 5-fluorocytosine (CD/5FC), E coli nitroreductase and CB1954 (NTR/CB1954), and human deoxycytidine kinase and cytosine arabinoside (dCK/AraC) were employed. The suicide genes were transduced into two thyroid carcinoma cell lines with retroviral vectors in which all the suicide genes were under the control of the same promoter. When the relative efficacy of four suicide gene/prodrugs was compared with therapeutic index and degree of bystander effect, we found a clear dissociation between these two parameters. Thus, HSV-TKIGCV demonstrated the widest therapeutic index, while CD/5FC and NTR/CB1954 showed the stronger bystander effect than HSV-TK/GCV. dCK/AraC had little efficacy. Advantages and limitations of each suicide gene/prodrug combinations are discussed.

Extensive surgery for primary malignant lymphoma of the heart.

The surgical treatment of primary malignant lymphoma of the heart in a 43-year-old man is reported. The tumor was extensively resected together with the right atrial wall and both venae cavae, and the resulting defect was repaired with a bovine pericardial patch. The postoperative course was fairly stable for more than 7 months following surgery, under a regular chemotherapy regimen. The patient died of acute pneumonia on the 234th postoperative day. The autopsy findings confirmed the diagnosis of primary malignant lymphoma of the heart.

Coronary revascularization and abdominal aortic aneurysm repair in a patient with Behçet's diseases.

Behçet's disease is a systemic disease characterized by oral aphta, genital ulcer, and ocular lesion. Arterial involvement is an uncommon complication of Behçet's disease, and it most frequently affects the abdominal aorta followed by the femoral artery and the pulmonary artery. Coronary lesions in Behçet's disease have been little reported in the literature. In this communication, we present a case with coronary artery stenosis and with subsequently developed supra-renal abdominal aortic aneurysm. The coronary lesions were revasculized with gastroepiploic artery, right internal mammary artery, and saphenous vein graft. Abdominal aortic repair was performed with partial cardiopulmonary stand by, because of the risk of coronary ischemia during the cross clamp including the celiac artery. To our knowledge, this is the first report of successful repair of combined lesions of the coronary and the abdominal aorta in a patient with Behçet's disease.

Stiff-man syndrome associated with antecedent myasthenia gravis and organ-specific autoimmunopathy.

We describe a case of stiff-man syndrome accompanied by diabetes mellitus, Hashimoto's thyroiditis and the antecedent myasthenia gravis. The diagnosis of stiff-man syndrome was made based on not only clinical findings and the characteristic electromyographic pattern but also the presence of antibodies to glutamic acid decarboxylase in the serum and cerebrospinal fluid. Stiff-man syndrome is known to be associated with organ-specific autoimmunopathy including insulin-dependent diabetes mellitus. The present case is the first one that stiff-man syndrome was preceded by myasthenia gravis of organ-specific autoimmunopathy. Stiff-man syndrome in the present case probably represents the one of fully expressed manifestations from the broad spectrum of organ-specific autoimmunopathy caused by the loss of self-tolerance.

Pericardio-peritoneal drainage using a subcostal approach.

A 56-year-old man admitted to our hospital for cardiac tamponade due to dilated cardiomyopathy did not respond to treatment by usual medical means or surgery. Pericardio-peritoneal drainage was conducted using a subcostal approach. Seven months later, the patient remains well and free of signs of pericardial tamponade. This method has proved to be safe and effective in patients with persistent massive pericardial effusion.

Successfully treated descending necrotizing mediastinitis through mediansternotomy using a pedicled omental flap.

A 21-year-old man with an oropharyngeal abscess admitted to our institution was initially treated with systemic antibiotics but was referred to our department when his condition rapidly deteriorated. His respiratory insufficiency required circulatory support. A computed tomographic scan showed a parapharyngeal abscess descending into the mediastinum with multiple right-side capsulized empyema and pericardial effusion. We conducted emergency surgery through a mediansternotomy using a pedicled omental flap. Postoperative clinical and radiologic assessment showed a normal chest X-ray and primary wound healing without sternal dehiscence. Mediansternotomy using a pedicled omental flap offers excellent exposure for a complete one-stage operation with debridement of all affected tissues of the subauricular region, the mediastinum, and both pleural cavities. We conclude that this method yields good results for patients with acute widespread descending necrotizing mediastinitis.

Association of Stat3-dependent transcriptional activation of p19INK4D with IL-6-induced growth arrest.

Signal transducer and activator of transcription 3 (Stat3) is the major mediator of the IL-6-induced signals regulating growth and differentiation. In the M1 myeloleukemic cell line, Stat3 is a critical transcription factor causing repression of c-myc and c-myb genes, expression of junB and IRF1, growth arrest at G1, and subsequent macrophage differentiation. To understand the mechanisms by which Stat3 causes such effects, we searched for other Stat3-regulated genes possibly involved in growth arrest. We identified this inducible molecule as p19INK4D using a specific antibody. Both p19INK4D mRNA and protein were rapidly induced by IL-6 treatment without requiring de novo protein synthesis and the induction was fully suppressed by dominant-negative forms of Stat3. Thus both Stat3-regulated events, repressions of c-myc and c-myb and induction of p19INK4D, are likely to be involved in IL-6-induced growth arrest in M1 cells.

[Axillo-femoral bypass for adult form of extreme coarctation of the aorta--the long term prognosis].

A 33-year-old female with adult form of extreme coarctation underwent axillo-femoral bypass grafting. The postoperative hemodynamic improvement was remarkable. The patient spent excellent quality of life without any hypotensive drug or anticoagulant agent for 14 years until pseudoaneurysms of the bypass graft ruptured. The patient was saved by an emergency operation with 2 steps of surgical procedures. The first step was making the new axillo-femoral bypass at the contralateral side, then the diseased graft was replaced by a new graft as the second step. The postoperative catheterization revealed no pressure gradient between the upper and lower extremities, and the bilateral API's were over 100%. The pseudoaneurysm of the graft seemed to be caused by the stabbed needle holes for the dearing of the graft and the instrument for the partial occlusion of the graft. We learned from this experience that the needle holes of the graft should be repaired by plegeted sutures, and Fogarty clamp or the clamp with rubber sheath should be used for clamping graft. The axillo-femoral bypass is, of course, not a first choice procedure for extreme coarctation, but the hemodynamic improvement was achieved in our case. Therefore, it may be still useful for the compromised host as an alternative procedure to the radical correction.

[Stanford type A aortic dissection with closed false lumen: analysis of prognostic factors at initial CT or MRI].

Nineteen patients with Stanford type A acute aortic dissection with closed false lumen were reviewed. In the follow-up examinations, ulcerlike projection (ULP) in the ascending aorta (AA) or aortic arch (AR) was identified in 8 of 19 patients. In 5 of these 8 patients, acute cardiac tamponade occurred and 3 of them died. In the other 11 patients, there was no mortality, and only one patient underwent elective surgery. The appearance of ULP in the AA/AR is considered an indication for urgent surgery because it is regarded as a precursor of lethal complications such as cardiac tamponade. The purpose of this study was to investigate predictors of the appearance of ULP in the AA/AR with early imagings (CT or MRI) before the appearance of ULP. The patients were divided into two groups: patients with ULP in the AA/AR (8 patients) and others (11 patients). Initial CT or MRI findings of the thoracic aorta were retrospectively statistically analyzed in each group. Three predictive factors were statistically significant for the appearance of ULP in the AA/AR (diameter of the AA > or = 5 cm, thickness of the false lumen of the AA > or = 1 cm, thickness of the false lumen of the AA > or = that of the descending aorta). Close attention should be paid, if any of these 3 factors is observed at initial CT or MRI.

Fate of intramural hematoma of the aorta: CT evaluation.

PURPOSE: Our goal was to investigate the fate of intramural hematoma of the aorta. METHOD: In 32 patients with intramural hematoma of the aorta, we reviewed CT (n = 32) and MR (n = 22) findings. The diagnosis was established by CT, and regular follow-up studies were performed. RESULTS: All intramural hematomas decreased in size. Ulcer-like projections (ULPs) were identified at the initial study in 6 patients and during the follow-up period in 14 patients. The ULPs progressed to saccular aneurysm in 12 patients (mean 47.0 days), while fusiform aneurysm developed in 6 patients (mean 347.7 days) without ULP. In two patients, the affected aorta progressed to overt aortic dissection. CONCLUSION: Intramural hematoma itself usually decreases in size. However, the affected aorta can progress to aneurysm or overt aortic dissection. Development of saccular aneurysm from ULPs can be considered an early complication. In cases without ULP, fusiform aneurysm may develop as a late complication. All intramural hematomas need to be followed since it seems to be difficult to predict the exact fate of intramural hematoma from the initial imaging findings.