PubMed Health⌕ Search

Biomedical subjects

Yasuhiro Ito

Publications and source records attributed to Yasuhiro Ito.

At least 19 recordsLinked to original sources
PubMed2007

Lateral and mediastinal lymph node dissection in differentiated thyroid carcinoma: indications, benefits, and risks.

BACKGROUND: There are 3 compartments of regional lymph nodes to which thyroid carcinoma metastasizes: central, lateral, and mediastinal compartments. The central compartment is the nearest to the thyroid and usually dissected routinely. However, the indication for dissection of the lateral and mediastinal compartments for differentiated thyroid carcinoma remains an open question. METHODS: The indication for dissection of lateral and mediastinal compartments is evaluated based on previous reports, including those from our department. RESULTS: There is nothing controversial about the indication for therapeutic lateral node dissection for tumors with clinically apparent lateral node metastasis. Such cases are more likely to show recurrence, especially in previously dissected compartments, and surgeons must perform dissection carefully. Although there are no randomized studies on the indication for prophylactic lateral node dissection, it is recommended for papillary carcinoma with aggressive characteristics such as large size and massive extrathyroid extension. Prophylactic mediastinal dissection via median sternotomy is not recommended. CONCLUSIONS: Node dissection of the lateral and mediastinal compartments must be performed aggressively and radically to prevent recurrence in previously dissected regions.

Adenocarcinoma, Follicular↗
PubMed2007

Clinicopathologic significance of intrathyroidal epithelial thymoma/carcinoma showing thymus-like differentiation: a collaborative study with Member Institutes of The Japanese Society of Thyroid Surgery.

Intrathyroidal epithelial thymoma (ITET)/carcinoma showing thymus-like differentiation (CASTLE) is a rare malignant tumor having histopathologic features similar to those of squamous cell carcinoma of the thyroid and other organs and a more favorable prognosis. It is thought to originate from ectopic thymic tissue or embryonic thymic rest in or adjacent to the thyroid. We investigated clinicopathologic features of 25 cases of ITET/CASTLE. The sensitivity and specificity of the pathologic diagnosis of ITET/CASTLE by immunohistochemical staining with CD5, a marker of carcinoma of thymic origin, were 82% and 100%, respectively. The 5- and 10-year cause-specific survival rates were 90% and 82%, respectively. Nodal metastasis and tumor extension predict a worse prognosis. Of 22 patients who had curative surgery, 10 (45%) underwent adjuvant radiation therapy, and no locoregional recurrence was seen in any of them. This is the first study demonstrating the survival curve for patients with ITET/CASTLE. Our findings suggest that curative resection followed by radiation therapy may effectively prevent locoregional recurrence and CD5 immunostaining is useful for diagnosing ITET/CASTLE.

Adult↗
PubMed2006

High-resolution analysis of (Sc3C2)@ C80 metallofullerene by third generation synchrotron radiation X-ray powder diffraction.

The X-ray structure of Sc(3)C(82) is redetermined by the MEM/Rietveld method by using synchrotron radiation powder data at SPring-8, where the C(2) encapsulated structure available to discuss the Sc-Sc interatomic distances has been determined. The encapsulated three scandium atoms form a triangle shape. A spherical charge distribution originating from the C(2) molecule is located at the center of the triangle. Interatomic distances between Sc and Sc are 3.61(3) A in the triangle. The distance between Sc and the center of the C(2) molecule is 2.07(1) A.

Journal Article↗
PubMed2006

Sox10 regulates ciliary neurotrophic factor gene expression in Schwann cells.

Ciliary neurotrophic factor (Cntf) plays an essential role in postnatal maintenance of spinal motoneurons. Whereas the expression of this neurotrophic factor is low during embryonic development, it is highly up-regulated after birth in myelinating Schwann cells of rodents. To characterize the underlying transcriptional mechanisms, we have analyzed and compared the effects of various glial transcription factors. In contrast to Pit-1, Oct-1, Unc-86 homology region (POU) domain class 3, transcription factor 1 (Oct6/SCIP/Tst-1) and paired box gene 3 (Pax3), SRY-box-containing gene 10 (Sox10) induces Cntf expression in Schwann cells. Subsequent promoter analysis using luciferase reporter gene and EMSA identified the corresponding response elements within the Cntf promoter. Overexpression of Sox10 in primary sciatic nerve Schwann cells leads to a >100-fold up-regulation of Cntf protein, and suppression of Sox10 by RNA interference in the spontaneously immortalized Schwann cell line 32 reduces Cntf expression by >80%. Mice with heterozygous inactivation of the Sox10 gene show significantly reduced Cntf protein levels in sciatic nerves, indicating that Sox10 is necessary and sufficient for regulating Cntf expression in the peripheral nervous system.

Animals↗
PubMed2006

Co-expression of matriptase and N-acetylglucosaminyltransferase V in thyroid cancer tissues--its possible role in prolonged stability in vivo by aberrant glycosylation.

UDP-N-acetylglucosamine:alpha-mannoside beta-1,6-N-acetylglucosaminyltransferase (GnT-V) catalyzes the formation of beta-1-6 GlcNAc branches on asparagine-linked oligosaccharides, which is directly linked to tumorigenesis. Our recent studies indicate that the secretion of matriptase from cancer cells is increased via the action of GnT-V, as evidenced by the fact that matriptase-bearing beta-1-6 GlcNAc branching is dramatically inhibited. In this study, we report on an investigation of the expression of GnT-V and matriptase in thyroid neoplasm tissues to determine the clinical significance on the co-expression of these two proteins in thyroid cancer. Although neither GnT-V nor matriptase was expressed in normal thyroid tissue, positive staining for matriptase and GnT-V was observed in 52/68 and 66/68 cases of papillary carcinoma, 3/23 and 10/23 cases of follicular carcinoma, 5/13 and 9/13 cases of follicular adenoma, and 11/28 and 6/28 cases of anaplastic carcinoma, respectively. Immunohistochemistry, as well as western blotting, showed that the expression of matriptase paralleled the expression to GnT-V. However, the expression of matriptase mRNA was not correlated with its protein levels, suggesting that the enhancement in matriptase expression could be regulated by a posttranslational modification such as glycosylation through GnT-V-mediated glycosylation. In papillary carcinoma, the levels of expression of both GnT-V and matriptase were significantly higher in tumors 1 cm or less in size (microcarcinoma) and in those without poorly differentiated lesions, and the two proteins were significantly correlated. In contrast, the prognosis of thyroid carcinoma after surgery was neither correlated with the expression GnT-V nor matriptase, because the levels of their expression were quite low in anaplastic (undifferentiated) carcinomas. These results suggest that prolonged stabilization of matriptase is stabilized by GnT-V-mediated glycosylation in vivo, thus extending its halftime and permitting it to play role in the early phases of papillary carcinoma, but not in its later phase progression.

Blotting, Western↗
PubMed2006

Clinical significance of metastasis to the central compartment from papillary microcarcinoma of the thyroid.

We previously demonstrated that for papillary microcarcinoma (PMC), (1) patients with lateral lymph node metastasis detected on preoperative ultrasonography (US) are more likely to develop recurrence, and (2) dissection of the lateral compartment does not improve the prognosis of patients without US-detectable lateral metastasis. In this study, we focused on metastasis from PMC to the central compartment. We investigated the clinical significance of lymph nodes in the central compartment using the same series of 600 patients as used in the previous study. Ultrasound-diagnosed central node metastasis could be found in 30 patients (20.0%). Although the specificity of US for detecting central node metastasis was 99.1%, sensitivity was only 10.9%. Neither US-diagnosed nor pathologically confirmed central node metastasis affected the disease-free survival (DFS) rate of PMC patients. Furthermore, in cases where PMC was located only in one lobe, central node dissection in the contralateral lobe did not improve the DFS rate. These findings suggest that, for PMC, (1) US is an insensitive technique for detecting the central node metastasis, (2) the presence of central node metastasis is unrelated to DFS of patients, and (3) when performing lobectomy for PMC involving only one lobe, dissection of the central compartment in the contralateral lobe is optional.

Adult↗
PubMed2006

Prognostic significance of extrathyroid extension of papillary thyroid carcinoma: massive but not minimal extension affects the relapse-free survival.

OBJECTIVES: Extrathyroid extension has been recognized as a prognostic factor in papillary thyroid carcinoma. In the most recent version of the UICC TNM classification system, extrathyroid extension has been classified into two grades, minimal extension (extension to sternothyroid muscle or perithyroid soft tissues) and massive extension (extension to subcutaneous soft tissue, larynx, trachea, esophagus, or recurrent laryngeal nerve). In this study, we investigated the prognostic significance of each of the two types of extension. PATIENTS AND METHODS: One thousand and sixty-seven patients with papillary thyroid carcinoma without distant metastasis at surgery, who underwent surgical treatment in Kuma hospital between 1990 and 1995 and had been followed postoperatively for 60 months or more, were enrolled in this study. The grading of extrathyroid extension was based on both pathological findings and intraoperative surgical findings. RESULTS: In univariate analysis, although patients with massive extension showed a significantly worse relapse-free survival (RFS) rate than those with no or minimal extension (P < 0.0001), there was no difference in the RFS rate between patients with no extension and those with minimal extension. Among patients with massive extension, the RFS rate tended to be worse in those with posterior extension than in those with anterior extension (P = 0.0562). Furthermore, the RFS rate of patients with massive posterior extension only to the recurrent nerve demonstrated a better RFS rate than those with extension to other posterior organs (P = 0.0052). Multivariate analysis demonstrated that massive extrathyroid extension is recognized as an independent prognostic factor for RFS (P = 0.0003). CONCLUSIONS: These findings suggest that (1) upgrading of T category for tumors with massive extension is appropriate, whereas that for tumors with only minimal extension is not, and (2) careful surgical treatment and postoperative follow-up are required for tumors with massive extension to posterior organs other than the recurrent laryngeal nerve.

Adenocarcinoma, Papillary↗
PubMed2006

Sensitivity and specificity of intraoperative recurrent laryngeal nerve stimulation test for predicting vocal cord palsy after thyroid surgery.

INTRODUCTION: Recurrent laryngeal nerve (RLN) palsy after thyroidectomy, although infrequently encountered, can decrease quality of life. In addition to the hoarseness that occurs with unilateral RLN palsy, bilateral RLN palsy leads to dyspnea and often to life-threatening glottal obstruction. Therefore, intraoperative awareness of the nerve's status is of great importance. This study examined the sensitivity and specificity of a palpation technique to detect contraction of the posterior cricoarytenoid muscle (PCA) through the posterior hypopharyngeal wall while the RLN was being stimulated with a disposable nerve stimulator during thyroid surgery (the laryngeal palpation test) to predict postoperative RLN deficits. METHODS: A total of 2197 RLNs in 1376 patients were identified to be at risk of injury during thyroidectomy performed between July 2003 and August 2004. Postoperative RLN integrity was assessed using direct laryngoscopy or laryngofiberoscopy to visualize vocal fold mobility. RESULTS: Altogether, 76 RLNs failed to elicit a PCA contraction in response to nerve stimulation, and 80 cases of temporary vocal cord palsy and 21 cases of permanent vocal cord palsy were recognized on postoperative evaluation. For postoperative vocal cord palsy, the sensitivity and specificity of the laryngeal palpation test were 69.3% and 99.7%, respectively, with a positive predictive value of 92.1% and negative predictive value of 98.5%. For permanent vocal cord palsy, the sensitivity and specificity were 85.7% and 97.3%, respectively, with a positive predictive value of 23.7% and negative predictive value of 99.8%. CONCLUSIONS: The laryngeal palpation test is not a particularly useful method for predicting the level of RLN function after thyroidectomy. All patients must be examined postoperatively by direct laryngoscopy or laryngofiberoscopy to check vocal cord mobility. Even if there is no contraction of the PCA and we detect vocal cord palsy immediately after surgery, vocal cord palsy often recovers within 1 year when visual preservation of RLN is successful.

Adolescent↗
PubMed2006

A prophylactic infusion of calcium solution reduces the risk of symptomatic hypocalcemia in patients after total thyroidectomy.

BACKGROUND: Several risk factors have been associated with post-operative transient hypocalcemia after thyroid surgery. However, there are no studies evaluating preventive measures to avoid symptomatic postoperative hypocalcemia. Although intravenous infusion of calcium improves hypocalcemic symptoms, it is unknown whether prophylactic infusion prevents symptoms of postoperative hypocalcemia. PATIENTS AND METHODS: Five hundred and forty-seven patients underwent total thyroidectomy. Two groups were identified: group A (n = 243) received prophylactic intravenous drip infusion of 78-156 mg of calcium solution at 3-8 hours after operation, and group B (n = 304) received no prophylactic treatment. Prophylactic infusion was used only once if the patients did not have symptoms of hypocalcemia. Serum calcium (Ca) levels, intact parathyroid hormone (i-PTH) levels on the first postoperative day (1st POD), and the prevalence of symptoms of hypocalcemia were prospectively analyzed. RESULTS: The serum Ca levels at the 1st POD in group A patients (7.91 +/- 0.49 mg/dl, mean +/- SD) was significantly higher than group B patients (7.65 +/- 0.54, P < 0.0001), while the serum i-PTH levels were not significantly different between the two groups. The prevalence of numbness and/or tetany before noon on the 1st POD was significantly lower in group A patients. Prophylactic infusion of calcium solution reduced the prevalence of tetany from 8.6% to 2.1%. CONCLUSION: A prophylactic infusion of calcium solution after total thyroidectomy may be useful in reducing the development of symptomatic hypocalcemia and reduces the patients' risk of having discomfort and anxiety due to hypocalcemia.

Calcium↗
PubMed2006

Clinical significance of lymph node metastasis of thyroid papillary carcinoma located in one lobe.

BACKGROUND: Previous studies have shown that lymph node metastasis can be of prognostic value. In this study, we investigated the clinical significance of node metastasis focusing on metastasis in the central compartment for patients with papillary carcinoma located in one lobe. PATIENTS AND METHODS: We investigated the frequency of lymph node metastasis in 759 patients with papillary carcinoma to determine whether and how such metastasis affects disease-free survival (DFS). RESULTS: Central node metastasis was observed in 63% of patients, and the frequency was increased in relation to tumor size. The frequency of lateral node metastasis was 62.0%, which was also directly related to tumor size. On multivariate analysis of cases showing tumor larger than 1 cm, central node metastasis was recognized as an independent prognostic factor of DFS. The frequency of metastasis to the paratracheal nodes contralateral to the tumor was drastically elevated for tumors larger than 1 cm, but metastasis to this region did not independently predict worse DFS. CONCLUSION: Central node metastasis independently predicts a worse DFS for patients with papillary carcinoma larger than 1 cm.

Adult↗
PubMed2006

Minimal extrathyroid extension does not affect the relapse-free survival of patients with papillary thyroid carcinoma measuring 4 cm or less over the age of 45 years.

PURPOSE: In the most recent version of the UICC TNM classification system for thyroid carcinoma, tumors with minimal extrathyroid extension were classified as T3. In this study, we investigated whether this upgrading is appropriate for papillary thyroid carcinoma. METHODS: We investigated the difference in the relapse-free survival (RFS) rate between patients with tumors having no, minimal, and massive extrathyroid extension in a series of 502 patients over the age of 45 years. RESULTS: Patients with tumors showing massive extension showed a worse RFS rate except for those with tumors measuring 1 cm or less. However, there was no significant difference in RFS between tumors measuring 4 cm or less showing no or minimal extension. In an investigation of 409 patients without any clinically apparent node metastasis, the RFS of patients with tumors larger than 4 cm with massive extension was significantly worse than those with tumors measuring 4 cm or less, while the RFS of patients with tumors with either no or minimal extension did not depend on the tumor size. CONCLUSIONS: These findings suggest that tumors with minimal extension should be classified to have the same T grade as those without such extension, and upstaging of such tumors is therefore not appropriate.

Aged↗
PubMed2006

Delta Np73 expression in thyroid neoplasms originating from follicular cells.

AIMS: p73, a homologue of p53, is known as a negative regulator of tumour progression. However, delta Np73, an isoform of p73 lacking the NH2-terminal transactivation domain plays an oncogenic role by interfering with the activity of p53 and TA (full-length transactivating isoforms) p73. In this study, we investigated the expression of delta Np73 in human thyroid neoplasms originating from follicular cells. METHODS: We immunohistochemically investigated delta Np73 expression in 223 thyroid neoplasms. Delta Np73 expression level was evaluated as the sum of positivity score and intensity score. RESULTS: Normal follicular cells did not express delta Np73, but 27.3% of follicular adenoma, 85.4% of follicular carcinoma, 99.2% of papillary carcinoma, and 95.7% of anaplastic carcinoma were positive for the transcript. Delta Np73 expression level did not differ between widely invasive and minimally invasive follicular carcinomas. In papillary carcinoma, the level was inversely linked to tumour size, extrathyroid extension, and clinically apparent metastasis. Furthermore, in anaplastic carcinoma, delta Np73 expression level was significantly lower than that in papillary carcinoma. CONCLUSIONS: Our findings indicate that delta Np73 plays a role predominantly in the early phase of papillary carcinoma progression.

Adenocarcinoma, Follicular↗
PubMed2006

Inverse relationships between the expression of MMP-7 and MMP-11 and predictors of poor prognosis of papillary thyroid carcinoma.

AIMS: Matrix metalloproteinases (MMPs) have various functions that play roles in carcinoma development. In this study, we investigated the expression of two representative MMPs, MMP-7 and MMP-11, in papillary thyroid carcinomas. METHODS: We immunohistochemically investigated the expression of these MMPs in 196 cases of papillary carcinoma. RESULTS: A high level of MMP-7 expression was observed in 56 cases (28.3%). The expression level was significantly decreased in cases showing large tumour, N positivity, large pT and poor differentiation. MMP-11 expression was high in 119 cases (60.1%). The expression level was inversely related to tumour size, N factor, pT factor, pN factor, extrathyroid extension, and poor differentiation. CONCLUSIONS: In contrast to other MMPs, MMP-7 and MMP-11 are inversely linked to aggressive characteristics of papillary thyroid carcinoma and their down-regulations may even be a marker of poor prognosis in patients.

Biomarkers, Tumor↗
PubMed2006

Needle tract implantation of follicular neoplasm after fine-needle aspiration biopsy: report of a case.

We herein report a 28-year-old woman with a follicular neoplasm showing subcutaneous needle tract implantation. One month after fine-needle aspiration biopsy (FNAB) for a tumor measuring 2.5 cm, the patient became aware of a subcutaneous nodule measuring about 1 cm at the needle insertion site. FNAB smear of this nodule showed poorly cohesive clusters of follicular cells with nuclear crowding, overlapping and resetting with some microfollicular architecture. Total thyroidectomy and resection of the subcutaneous nodule were performed. Although there was no capsular or vascular invasion of the nodule, the lesion was diagnosed as follicular carcinoma because of the subcutaneous seeding. Ki-67 labeling indices of the thyroid nodule and implanted tumor were higher than 5%. Furthermore, although galectin-3 was completely negative in the thyroid nodule, it was heterogeneously positive in the implanted tumor. It is therefore suggested that high cell proliferating activity as a characteristic of the original nodule and the subsequently obtained invasive characteristic of the implanted tumor contributed to this event. To date, there has not been any recurrence of the implanted lesion. Because implanted follicular carcinoma can be surgically removed, this complication should not impair the usefulness of FNAB.

Adult↗
PubMed2006

Thyroxine to triiodothyronine hyperconversion thyrotoxicosis in patients with large metastases of follicular thyroid carcinoma.

OBJECTIVE: We experienced two cases of follicular thyroid carcinoma with distant metastases, which showed high levels of free triiodothyronine (T(3)) while free thyroxine (T(4)) levels remained in the low or normal range. In this report, we described the detail of these cases and examined the cause of T(3) thyrotoxicosis. DESIGN: In one of the cases, quantitative measurement of types I and II iodothyronine deiodinase mRNAs was performed using a surgically dissected tissue from the primary tumor and a distant metastasis. MAIN OUTCOME: In the both tissues, types I and II iodothyronine deiodinase mRNAs were expressed in the same level as in the normal thyroid tissues. CONCLUSION: These results suggest that T(3) thyrotoxicosis in our patients was caused by hyperconversion of administered levothyroxine to T(3). In the follow-up of patients with distant metastases of follicular carcinoma, not only free T(4), but also free T(3) should be tested to avoid the excessive administration of levothyroxine.

Adenocarcinoma, Follicular↗
PubMed2006

Transient vocal cord paralysis after fine-needle aspiration biopsy of thyroid tumor.

OBJECTIVE: Complications of thyroid fine-needle aspiration biopsy (FNAB) are exceedingly rare. Hematoma formation is the most commonly encountered complication. Infection and seeding of carcinoma cells in the needle track has also been reported in a rare case. Here we describe patients diagnosed as having transient vocal cord paralysis after FNAB of benign thyroid tumor. DESIGN: Retrospective review of patients with concurrent diagnosis of vocal cord paralysis after FNAB. MAIN OUTCOME: Among 10,974 patients who underwent FNAB, 4 patients showed vocal cord paralysis on laryngoscopy. These patients had solid and/or cystic lesion in the thyroid. Routine FNAB of the nodule was performed using a 23-gauge needle. Cytologic findings were benign tumor. Change of voice in the patients occurred 1 or 2 days after FNAB and vocal cord paralysis ipsilateral to FNAB was determined by flexible laryngoscopy. Vocal cord paralysis of all patients resolved spontaneously within 6 months (average, 4 months). CONCLUSION: Although the incidence of vocal cord paralysis in patients with thyroid tumor after FNAB is reported to be 0.036%, the true incidence is unknown because asymptomatic subjects are not screened. This report should alert the examiner to the possibility of vocal cord palsy after FNAB.

Aged↗