Biomedical subjects

Toshihiro Masatsugu

Publications and source records attributed to Toshihiro Masatsugu.

9 recordsLinked to original sources

PubMed2006

Association of Polycomb group SUZ12 with WD-repeat protein MEP50 that binds to histone H2A selectively in vitro.

SUZ12 is a Polycomb group protein that forms Polycomb repressive complexes (PRC2/3) together with EED and histone methyltransferase EZH2. Although the essential role of SUZ12 in regulating the activity of the PRC2/3 complexes has been demonstrated, additional function of this protein was suggested. Here, we show that SUZ12 interacts with WD-repeat protein MEP50 in vitro and in vivo. We show that the MEP50 binds histone H2A selectively among core histones, and mediates transcriptional repression of protein arginine methyltransferase PRMT5, which is known to methylate H2A and H4. These results suggest that SUZ12 might have a role in transcriptional regulation through physical interaction with MEP50 that can be an adaptor between PRMT5 and its substrate H2A.

Adaptor Proteins, Signal Transducing↗

PubMed2005

Significant clinical differences in primary hyperparathyroidism between patients with and those without concomitant thyroid disease.

PURPOSE: We evaluated the differences in diagnosis and treatment for primary hyperparathyroidism (pHPT) in patients with and those without concomitant thyroid disease. METHODS: One hundred and ten patients with pHPT underwent parathyroid localization and thyroid examination by ultrasonography (US) and sestamibi scintigraphy (MIBI). The clinical and biochemical findings, parathyroid localization, and operations performed were compared in 49 patients without thyroid disease and 61 patients with thyroid disease. RESULTS: Asymptomatic hypercalcemia was significantly more prevalent in patients with concomitant thyroid disease (88.5%) than in those without thyroid disease (49.0%) (P < 0.01). The mean serum calcium was significantly higher and the inorganic phosphate level was significantly lower in patients without concomitant thyroid disease than in those with concomitant thyroid disease (P < 0.05, P < 0.01, respectively). The pathologic parathyroid gland was identified significantly more often in patients without concomitant thyroid disease than in those with concomitant thyroid disease both by US and MIBI (P < 0.05). Unilateral exploration was performed more often in patients without thyroid disease than in those with thyroid disease (P < 0.01). CONCLUSION: Primary hyperparathyroidism was diagnosed at an earlier stage in patients with concomitant thyroid disease. Thyroid disease concomitant with pHPT influenced parathyroid localization as well as the indication for minimally invasive parathyroidectomy.

Adult↗

PubMed2005

Thyroid evaluation in patients with primary hyperparathyroidism.

We evaluated the efficacy of preoperative high-resolution ultrasonography (US) for diagnosing possible concomitant thyroid disease which affects the surgical management in patients with primary hyperparathyroidism (pHPT). One hundred and nine patients with sporadic pHPT underwent US with or without ultrasound-guided fine-needle aspiration biopsy (US-FNAB). Diagnosis of concomitant thyroid nodules by US and US-FNAB were compared with the histopathological findings. Of the 109 patients, 19 (17.4%) had malignant thyroid nodules, 26 (23.9%) had benign thyroid nodules alone, and 12 (11.0%) had diffuse goiter. The sensitivity, specificity, and accuracy of diagnosing 72 thyroid nodules were 91.3%, 91.8%, and 91.7% for US, 57.9%, 94.3%, and 81.5% for US-FNAB, and 95.7%, 91.8%, and 93.1% for combined US and US-FNAB, respectively. True positive/false negative ratio of US-FNAB diagnosis was significantly lower in nodules of 5-9 mm than nodules of 10 mm or more. Four unexpected thyroid cancers existed at a different site in 3 of the 39 patients with palpable thyroid disease. Five thyroid cancers were histopathologically confirmed in 5 (7.1%) of 70 patients without palpable thyroid disease. Eight (88.9%) of the 9 non-palpable thyroid cancers were accurately diagnosed by combined US and US-FNAB. Preoperative US is useful for evaluation of possible concomitant thyroid disease, especially for prediction of malignancy.

Adenoma↗

PubMed2004

Crank-shaped sternotomy for upper mediastinal lymph node dissection in patients with differentiated thyroid cancer.

We describe our modification of the reversed T-shaped sternotomy. The conventional technique consists of a limited upper sternotomy with transverse division of the sternum. Our modification involves shifting the transverse division lines one costal space between the right and left sides for perfect apposition of the divided upper and lower sternum. This technique can be used for patients with thyroid cancer and mediastinal lymph node metastasis and for those with a mediastinal tumor or certain cardiac disorders.

Female↗

PubMed2003

Influence of renal function on clinico-pathological features of primary hyperparathyroidism.

OBJECTIVE: Disturbed renal function may play an important role in the clinico-pathological presentation of primary hyperparathyroidism (pHPT). We studied the influence of renal function on the clinico-pathological characteristics of 141 patients (123 women and 18 men) with surgically proven pHPT. METHODS: The 141 patients were assigned to one of two groups based on creatinine clearance (C(cr)) level: a renal insufficiency group (n=37) in which C(cr) of patients was <70 ml/min and a normal renal function group (n=104) in which C(cr) was > or =70 ml/min. Clinical presentation and biochemical indices were evaluated and compared between the two groups. RESULTS: Age, and frequency of hypertension and of diabetes mellitus were significantly (P<0.001, P<0.05 and P<0.05 respectively) higher in the renal insufficiency group than in the normal renal function group. Serum levels of calcium, intact parathyroid hormone and bone Gla protein were significantly (P<0.05) higher and the excised parathyroid weighed significantly more (P<0.05) in the renal insufficiency group than in the normal renal function group; however, serum 1,25-dihydroxyvitamin D (1,25(OH)(2)D) and 24 h urinary calcium excretion were significantly (P<0.001 and P<0.05 respectively) lower in the former than in the latter group. There was a significant inverse correlation between C(cr) level and serum calcium (r=0.315, P<0.001) and a significant positive correlation between C(cr) level, 1,25(OH)(2)D (r=0.315, P<0.001), and 24 h calcium excretion (r=0.458, P<0.0001). CONCLUSIONS: Clinico-pathological features of pHPT were notably influenced by even moderate renal insufficiency. Urinary calcium excretion decreased according to the decrease in glomerular filtration rate. Therefore, endocrinologists need to appraise urinary calcium excretion and renal function of pHPT patients when considering surgery or in discriminating familial hypocalciuric hypercalcemia.

Aged↗

PubMed2002

Vitamin D status in Japanese patients with hyperparathyroidism: seasonal changes and effect on clinical presentation.

The disturbance of vitamin D metabolism plays an important role in determining the clinical presentation of hyperthyroidism. We studied 72 patients (65 women, 7 men) with primary hyperparathyroidism (pHPT). Clinical presentation, biochemical indices, and bone mineral density (BMD) were compared in three patient groups classified according to their serum 25-hydroxyvitamin D (25OHD) levels: 23 patients whose 25OHD level was <25 nmol/L comprised the low group, 26 whose level was 25 to 40 nmol/L made up the intermediate group, and 23 whose level was > 40 nmol/L comprised the high group. The mean serum calcium level was 10.8 +/- 0.9 mg/dl, and the mean weight of the resected parathyroids was 684 +/- 749 mg. The mean serum 25OHD level was 36.5 +/- 16.3 nmol/L (normal 25-100 nmol/L). Levels were below normal in 23 patients (32%). No between-group differences existed for clinical presentation, biochemistry, or BMD. Only differences in mean patient age were statistically significant between groups. Vitamin D deficiency is common among Japanese patients with pHPT, but the effects of HPT on clinical, biochemical, and densitometric indices are not pronounced. Our study population was at an early stage of pHPT, so the vitamin D deficiency may not be associated with the effects of HPT.

Adult↗

PubMed2002

Mucinous cystadenoma of the pancreas resected 11 years after cystgastrostomy.

There have been numerous reports that mucinous cystadenoma of the pancreas can transform to mucinous cystadenocarcinoma after cystenterostomy, but few authors have reported morphological changes long after cystenterostomy for mucinous cystadenoma. A 41-year-old Japanese woman had undergone cystgastrostomy at a nearby hospital 11 years before undergoing the treatment reported here. The preoperative diagnosis at the time of cystgastrostomy was a pancreatic cyst. At laparotomy a cyst, measuring 10cm in diameter, was found in the body and tail of the pancreas. The histopathological diagnosis of the cyst wall was mucinous cystadenoma of mild dysplasia. Computed tomography 10 years after the cystgastrostomy showed that the cyst had decreased in diameter from 10 cm to 5cm. Gastroscopy showed a scar at the cystgastrostomy site in the stomach. A complete resection of the mucinous cystadenoma was done, 11 years after the cystgastrostomy, because of the malignant potential. The resected specimen showed mucinous cystadenoma of mild dysplasia with structural and cellular atypia similar to that in the previous specimen. There was no malignant change. The patient was discharged after an uneventful postoperative course and no recurrence has been evident for 6 months to date. This case showed imaging and histopathological evidence of the slow-growing nature of mucinous cystadenoma of the pancreas.

Adult↗

PubMed2002

Serous cystadenoma of the pancreas associated with pancreas divisum.

Pancreas divisum is an embryologic anomaly of the pancreas that is characterized by a lack of fusion of the dorsal and ventral pancreatic ducts. It is rarely associated with pancreatic neoplasms. We report herein a rare association of pancreas divisum and serous cystadenoma of the pancreas. A 46-year-old Japanese woman presented with epigastralgia. Ultrasonography, computed tomography (CT) and magnetic resonance cholangiopancreatography revealed a multilocular cystic mass, measuring 7 cm in diameter, with a central stellate scar, in the body and tail of the pancreas. Angiography demonstrated a relatively hypervascular mass, suppressing the splenic vein. No arterial encasement was evident. Endoscopic retrograde pancreatography through the major papilla demonstrated only the duct of Wirsung; cannulation into the minor papilla was unsuccessful. In addition, CT showed a mildly dilated main pancreatic duct draining into the minor papilla. Distal pancreatectomy and splenectomy were performed, with the tentative diagnosis being serous cystic neoplasm of the pancreas, possibly malignant, and pancreas divisum. The cut surface of the resected specimen had a honeycomb-like appearance and the specimen consisted of multiple cysts of various sizes. Histopathological examination showed multiple cysts lined by a single layer of flat or cuboidal epithelial cells with glycogen in the cytoplasm. There was no evidence of malignancy. The histopathological diagnosis was serous cystadenoma of the pancreas. To the best of our knowledge, only three cases of serous cystadenoma of the pancreas associated with pancreas divisum have been reported. We report the fourth case of such an association, and briefly review the literature.

Cholangiopancreatography, Endoscopic Retrograde↗

PubMedDate not supplied

Liver cyst with biliary communication successfully treated with laparoscopic deroofing: a case report.

A 71-year-old Japanese woman complained of right upper abdominal fullness and pain. Computed tomography revealed a huge cyst in the right lobe of the liver, measuring 16 cm in diameter. She underwent laparoscopic deroofing of the liver cyst. On operation, needle aspiration of the cyst yielded clear serous fluid without any bile contamination. However, after the cyst was deroofed with laparoscopic coagulating shears, bile leakage was recognized from a tiny orifice in the cyst cavity. A catheter was inserted via the orifice for cholangiography, which demonstrated a communication with the biliary tract. The orifice was easily closed with a laparoscopic suturing device. Operation time was 5 hours and 30 minutes, and blood loss was 300 grams. Pathological examination of the liver cyst was consistent with a simple cyst. The postoperative course was uneventful, and the patient has had no recurrence to date at 13 months. Laparoscopic deroofing is a recommended treatment for a liver cyst even in the presence of cystobiliary communication.

Aged↗