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J Iwata

Publications and source records attributed to J Iwata.

At least 37 records · Page 2Linked to original sources
PubMed1999

Pigmented squamous cell carcinoma of the scrotum associated with a lentigo.

Only 13 cases of pigmented squamous cell carcinoma (SCC) have been reported in the English language literature, with most frequent development in the oral cavity and conjunctiva. However, no case of pigmented SCC of the scrotum has been reported. We report here a case of pigmented SCC that arose primarily in the scrotum of a 70-year-old man. Light microscopically, this tumour exhibited the typical features of a pigmented SCC, including not only keratinization and intercellular bridges but also colonization by plump dendritic melanocytes with marked pigmentation. These features were clearly confirmed by immunohistochemistry, including strong positivity of tumour cells for high-molecular-weight cytokeratin and of colonizing melanocytes for HMB-45. The tumour was associated with a lentiginous lesion and partly involved it. Melanocytes entrapped from the lentigo might therefore have been activated during enlargement of this tumour, resulting in melanocyte colonization. Fourteen cases of pigmented SCC, including ours, are clinicopathologically reviewed.

Aged↗
PubMed1999

Nephrogenic adenoma of the bladder in a chronic hemodialysis patient.

BACKGROUND: Nephrogenic adenoma is an uncommon, benign metaplastic lesion occurring in the urothelium, usually as a response to chronic irritation or trauma. It is rarely encountered in hemodialysis patients. Endoscopically, these lesions can easily be mistaken for malignant tumors. METHODS/RESULTS: We report on a case of nephrogenic adenoma of the bladder in a chronic hemodialysis patient that was large and mistakenly diagnosed as transitional cell carcinoma in the initial biopsy. Histopathological examination of the total cystectomy specimen demonstrated the correct diagnosis of nephrogenic adenoma. CONCLUSION: Increased awareness by urologists and pathologists of nephrogenic adenoma may lead to its more accurate diagnosis.

Adenoma↗
PubMed1999

Method of lymphocytotoxic crossmatch test for feline renal transplantation.

The optimal condition for methods of lymphocytotoxic crossmatch test for feline renal transplantation was investigated. On separation of viable lymphocytes from whole blood, the best results were obtained when Ficoll-diatrizoate with 1.078 of a specific gravity at 20 degrees C was centrifuged with 800 x g for 30 min at 4 degrees C. A nylon wool column was used to separate T and B cells from lymphocyte fraction. The ratio of T cells in nylon wool effluent cells was 95%, while the ratio of B cells in adherent cells was 41%. Lymphocytotoxic crossmatch tests were performed by using the effluent cells as T cells and the adherent cells as B cells, at 37 degrees C (warm) and 4 degrees C (cold). The ratio of B cells in adherent cells was low, however, the result was utilized as a matching test before transplantation by combining with the T cell result. The trypan blue stain method made it easier than the eosin stain method to distinguish living and dead cells. The lymphocytotoxic crossmatch tests were performed on 15 pairs of healthy cats, and only one pair showed doubtful positive against anti-B cell cold antibodies. During acute rejection after renal transplantation in two pairs which were negative on any anti-lymphocyte antibodies before the transplantation, the anti-T cell warm antibodies became positive in both pairs, and the anti-T cell cold antibodies became positive on one of the two pairs.

Animals↗
PubMed1999

Co-overexpression of p53 protein and epidermal growth factor receptor in human papillary thyroid carcinomas correlated with lymph node metastasis, tumor size and clinicopathologic stage.

Expressions of p53 protein and epidermal growth factor receptor (EGFR) were immunohistochemically investigated in 111 patients with papillary thyroid carcinomas (PTC) in order to evaluate their co-expression in relation to lymph node metastases (LNM), tumor size and clinicopathologic stage. In PTC, positive staining for p53 in dewaxed sections was present in nuclei or cytoplasm, or in both, whereas surface linear or cytoplasmic staining for EGFR was observed with varying degrees of extent and intensity. Positive reaction (more than 10% of tumor cells positive) was observed in 65 cases (58. 5%) for p53, and in 87 cases (78.4%) for EGFR. A significant correlation was found between p53 protein and EGFR overexpressions (p<0.01). Notably, p53-positive cases always exhibited positive staining for EGFR. Forty-four patients (39.6%) exhibited concomitant LNM, most of whom had both p53 and EGFR expression in primary foci. Statistical analysis revealed that co-expression of p53 protein and EGFR was significantly correlated with LNM, tumor size and clinicopathologic stage, but no correlation was found between their co-expression and age or sex. Our findings suggest that overexpression of p53 protein or EGFR in PTC tends to be associated with a high frequency of LNM, increased tumor size and advanced clinicopathologic stage, and that co-expression of both p53 protein and EGFR may predispose to growth and progression of PTC. Our findings also suggest that p53 protein and EGFR expressions may be clinicopathologic and prognostic indicators of PTC.

Adolescent↗
PubMed1999

Dermatofibrosarcoma protuberans harboring t(9;22)(q32;q12.2).

More than 20 cases of dermatofibrosarcoma protuberans (DFSP) exhibiting chromosomal abnormalities have been reported. Approximately three fourths of these tumors have harbored supernumerary ring chromosomes, which have been suggested to be specific for this tumor. However, a small number of DFSPs with translocations such as t(2;17), t(X;7), and t(17;22) have recently been reported. We report a DFSP arising in a 23-year-old woman which unexpectedly exhibited the balanced translocation, t(9;22)(q32;q12.2) as the only anomaly with G-band technique. Dual-color fluorescence in situ hybridization (FISH) confirmed these cytogenetic findings. Similar to that previously reported for DFSPs with translocations, the present tumor also lacked ring chromosomes.

Adult↗
PubMed1998

Papid Growing Fibroadenoma in an Adlescent.

INTRODUCTION: We report a case of rapidly growing fibroadenoma. PATIENT: A 13-year-old girl consulted the outpatient clinic regarding a left breast mass. The mass was diagnosed as fibroadenoma by clinical examinations, and the patient was carefully monitored. The mass enlarged rapidly with each menses and showed a 50% increase in volume four months later. Lumpectomy was performed. The tumor was histologically diagnosed as fibroadenoma organized type and many glandular epithelial cells had positive immunohistochemical staining for anti-estrogen receptor antibody in the nuclei. CONCLUSION: The estrogen sensitivity of the tumor could account for the rapidgrowth.

Journal Article↗
PubMed1998

Specificity of pyridinium inhibitors of the ubiquinone reduction sites in mitochondrial complex I.

Dual binding sites for pyridinium-type inhibitors in bovine heart mitochondrial complex I have been proposed (Gluck, M. R., Krueger, M. J., Ramsay, R. R., Sablin, S. O., Singer, T. P., and Nicklas, W. J. (1994) J. Biol. Chem. 269, 3167-3174). The marked biphasic nature of the dose-response curve for inhibition of the enzyme by MP-6(N-methyl-4-[2-(p-tert-butylbenzyl)propyl]pyridinium) makes this compound the first selective inhibitor of the two sites (Miyoshi, H., Inoue, M., Okamoto, S., Ohshima, M., Sakamoto, K., and Iwamura, H. (1997) J. Biol. Chem. 272, 16176-16183). Modifications of the structure of MP-6 show that a tert-butyl group on the benzene ring, a methyl group attached to the pyridine nitrogen atom, para-substitution pattern in the pyridine ring, and the presence of a branched structure in the spacer moiety are important for the selective inhibition. On the basis of the structural specificity, we synthesized a selective inhibitor, MP-24 (N-methyl-4-[2-methyl-2-(p-tert-butylbenzyl)propyl]pyridinium), which elicits greater selectivity. Characterization of the inhibitory behavior of MP-24 provided further strong evidence for the dual binding sites model.

Animals↗
PubMed1998

Characterization of the ubiquinone reduction site of mitochondrial complex I using bulky synthetic ubiquinones.

A wide variety of alkyl derivatives of Q2 (6-geranyl-2, 3-dimethoxy-5-methyl-1,4-benzoquinone) and DB (6-n-decyl-2, 3-dimethoxy-5-methyl-1,4-benzoquinone), in which methoxy groups of the 2- and/or 3-positions of the quinone ring were replaced by other bulky alkoxy groups from ethoxy to butoxy, were prepared by novel synthetic procedures. Electron-accepting activities of the bulky quinones were investigated with bovine heart mitochondrial complex I and its counterpart of Paracoccus denitrificans(NDH-1) to elucidate structural and functional features of the quinone reduction site of the enzymes. The bulky quinone analogues served as sufficient electron acceptors from the physiological quinone reduction site of bovine complex I. Considering the very poor activities of even the ethoxy derivatives as substrates for other respiratory enzymes such as mitochondrial complexes II and III [He, D. Y., Gu, L. Q., Yu, L., and Yu, C. A. (1994) Biochemistry 33, 880-884], this result indicated that the quinone reduction site of bovine complex I is spacious enough to accommodate bulky exogenous substrates. In contrast to bovine complex I, bulky quinone analogues served as poor electron acceptors with Paracoccus NDH-1. These observations indicated that bovine complex I recognizes the substrate structure with poor specificity. The substituent effects in the 2- and 3-positions of the quinone ring on the electron-transfer activity with bovine complex I differed significantly between Q2 and DB series despite having the same total number of carbon atoms in the side chain. The inhibitory effect involving Q2 due to its geranyl side chain was markedly diminished by structural modifications of the quinone ring moiety. These findings indicate that the side chain plays a specific role in the redox reaction and that the quinone ring and side-chain moieties contribute interdependently to binding interaction. Moreover, structural dependency of the proton-pumping activity of the quinone analogues was comparable to that of the electron-transfer activity with bovine complex I, indicating that the mechanism of redox-driven proton-pumping does not differ depending upon the substrate structure.

Animals↗
PubMed1998

Ongoing osteolysis in patients with lymphangioma.

Severe osteolysis is a rare complication of lymphangioma. It can progress despite treatment and may be fatal. Four patients presented with massive osteolysis and serious related complications. Of these, two responded well to OK-432 therapy with arrest of the osteolysis. Complete recovery from life-threatening pleural effusion has been noted in one. Of the two nonresponders, one died of progressive osteolysis of the cervical and occipital bones, the other, despite therapy, still shows progressive osteolysis of the left leg from the femur to the phalanges. A boneless leg may be the outcome.

Adolescent↗
PubMed1998

Osteoclast-like giant cell tumor of the pancreas with metastases to gallbladder and lymph nodes. A case report.

Osteoclast-like giant cell tumor of the pancreas (OGTP) is a rare neoplasm, of which the histogenesis is still controversial. Here we report a case of OGTP involving the head of the pancreas in a 71-year-old woman with metastases to the gallbladder and lymph nodes. The primary and metastatic tumors had identical histopathological, immunohistochemical, ultrastructural and molecular biological features. Microscopically, the tumors were characterized by atypical, often pleomorphic mononuclear cells associated with the proliferation of benign-appearing osteoclast-like giant cells (OGCs). Electron microscopic observation provided ultrastructural evidence of epithelial differentiation of the mononuclear cells, including microvilli and desmosomes, which was not obtained for OGCs. On immunohistochemical study, OGCs stained for CD68 (KP-1), LCA and HAM56, whereas mononuclear cells only reacted with PCNA. These findings clearly suggest that mononuclear cells are capable of differentiation and proliferation and may have been the only true tumor cells in this neoplasm, and that OGCs may have been a paraneoplastic product of this rare tumor. On examination of DNA from dewaxed sections of the tumor, we found no p53 mutation in the tumor tissue, but found two K-ras mutations in codon 12; this pattern of mutation commonly occurs in pancreatic carcinoma, indicating a somewhat genetic relationship of OGTP to pancreatic carcinoma. Although OGTP often has a favorable prognosis, the outcome in the present case was poor due to early tumor spread, with less than two years postoperative survival.

Aged↗
PubMed1998

Malignant granular cell tumor: report of a case and review of the literature.

The histological, immunohistochemical and electron microscopic features of a rare malignant granular cell tumor (GCT) arising in the left radial nerve of a 54-year-old man are reported. Despite a lack of local recurrence following extirpation, the tumor metastasized to the skull five years later. Light-microscopically, both primary and metastatic tumors consisted of markedly atypical or pleomorphic neoplastic cells with abundant cytoplasm containing diastase-resistant periodic acid Schiff reaction-positive granules. These tumor cells were arranged in a sheet-like pattern with mitotic figures including atypical ones, and were frequently immunopositive for proliferating cell nuclear antigen and c-MET, the c-met proto-oncogene product. These findings reflect high-grade malignancy of the present tumor. In addition, the tumor cells were positive for S-100 protein and neuron-specific enolase. Ultrastructurally, a large number of intracytoplasmic granules featuring secondary lysosomes as well as long interdigitating cytoplasmic processes, intercellular intermediate junctions, discontinuous basal lamina-like structures, and stromal long-spacing collagen were observed. These findings indicated schwannian differentiation of the present tumor. In addition, based on a review of previously reported cases, the overall clinicopathological characteristics of malignant GCT were summarized.

Cell Nucleus↗
PubMed1998

Primary ovarian angiosarcoma: a case report and literature review.

Primary ovarian angiosarcoma is extremely rare. Only 16 cases have histologically been reported to date in the literature. A case of angiosarcoma arising in the right ovary of a 46-year-old female is presented. Grossly, the resected right ovary was completely replaced by a solid tumor mass, which revealed multiple necrotic and/or hemorrhagic foci. This case revealed the typical histological features of angiosarcoma with sinusoidal and solid patterns of anaplastic tumor cells. Immunohistochemically, tumor cells were strongly and diffusely positive for CD31 and CD34, in particular, along the cytoplasmic membrane of the tumor cells. Ultrastructurally, tumor cells possessed the intermediate junctions between tumor cells, discontinuous basal laminae attached to the irregularly shaped blood vessels and occasional cytoplasmic pinocytotic vesicles. These findings confirmed the case as being one of angiosarcoma of the ovary. The patient died 9 months after surgery as a result of developed multifocal brain metastases. A total of 17 cases reported as primary ovarian angiosarcoma, including this presented case, are clinicopathologically reviewed.

Antigens, CD34↗
PubMed1998

Adult T cell leukemia/lymphoma with massive involvement of cardiac muscle and valves.

An autopsy case of a 58-year-old woman with massive cardiac involvement of adult T cell leukemia/lymphoma (ATLL) is reported. She developed cardiac failure due to aortic and mitral regurgitation with cardiac infiltration of ATLL cells, and underwent replacement of both aortic and mitral valves. Studies of the cut-surfaces revealed diffuse thickening of the subendocardial wall of the left chamber with widespread whitish-brown tumor infiltrates. In the regions surrounding the replaced aortic and mitral valves there was also massive tumor cell infiltration. The tumor cells infiltrating the cardiac muscle wall were T cell in origin and exhibited Leu-3a (CD4)-positive immunoreaction. Ultrastructurally, tumor cells contained markedly indented nuclei and some were attached directly to the muscle cells. These findings suggest that this was an unusual form of ATLL with widespread involvement of the heart.

Biomarkers, Tumor↗
PubMed1997

Ameloblastoma of the mandible metastasizing to the orbit with malignant transformation. A histopathological and immunohistochemical study.

We report here a case of ameloblastoma of the mandible with multiple local recurrences and metastasis to the orbit. The patient was a 63-year-old Japanese woman with visual disturbance of her right eye. Diagnostic imaging revealed a mass occupying the right orbital apex with partial intracranial involvement. She had been surgically treated for mandibular ameloblastoma 27 years previously, and the tumour had recurred three times in the past 5 years. The orbital tumour and recurrent ameloblastomas were investigated histopathologically and immunohistochemically. The tumour changed in morphology as it recurred, from follicular ameloblastoma without atypia to apparent malignant tumours disclosing undifferentiated or squamoid features. On immunohistochemical analysis, staining for cytokeratin was positive in the squamoid cells but not in the undifferentiated cells. Both histopathologically and immunohistochemically, the orbital tumour was almost identical to the undifferentiated recurrent tumour. The orbital tumour was distinct from the primary site or sites of recurrence of ameloblastoma, and we concluded that the mandibular ameloblastoma underwent malignant transformation with multiple recurrences and finally metastasized to the orbit.

Ameloblastoma↗
PubMed1997

Epithelioid sarcoma producing granulocyte colony-stimulating factor.

An epithelioid sarcoma of the perineum of a 60-year-old man with widespread metastases produced leukocytosis, myeloid hyperplasia of the bone marrow, and splenomegaly. High titers of granulocyte colony-stimulating factor (G-CSF) were found in the patient's serum and primary culture medium of the tumor tissue. The tumor tissue extract contained m-RNA for G-CSF in large quantities, proving that the tumor was the source of this cytokine.

Granulocyte Colony-Stimulating Factor↗
PubMed1997

[A case of chromophobe cell renal carcinoma].

We report a case of chromophobe cell renal carcinoma. A 59-year-old female was admitted to our hospital with asymptomatic gross hematuria. Abdominal computerized tomography showed an approximately 4 cm. minimally enhancing mass in the left kidney. Angiography revealed a hypovascular tumor in the left kidney. Under the diagnosis of renal cell carcinoma, left radical nephrectomy was performed. The cut surface of the tumor was beige in color with few foci of hemorrhage and necrosis. Microscopically, the tumor was composed of the cells with voluminous reticulated cytoplasm stained lightly with routine hematoxylin and eosin. Hale's colloidal iron staining demonstrated a positive cytoplasmic reaction. Pathological diagnosis was chromophobe cell renal carcinoma. Chromophobe cell renal carcinoma is a recently established subtype of renal cell carcinoma, which has rarely been reported in Japan.

Carcinoma, Renal Cell↗
PubMed1996

High frequency of apoptosis in infantile capillary haemangioma.

Infantile capillary haemangioma (ICH) is a well-established clinicopathological entity which often regresses spontaneously. To elucidate the cause of spontaneous involution of ICH, the apoptotic and proliferative activities in seven cases of ICH were compared with those in five cases of lobular capillary haemangioma (LCH), using formalin-fixed paraffin-embedded tissue sections. The number of apoptotic cells detected by the modified in situ end-labelling method was significantly higher in ICH than in LCH, while the proliferative activities evaluated with mitosis and Ki-67 antigen expression did not differ significantly. Lewisy (Ley) antigen, an apoptosis-associated marker, was expressed in all cases of ICH but in none of LCH, while labelling for p53 protein and bcl-2 protein was almost completely negative in both tumours. These findings clearly demonstrate a much higher apoptotic activity in ICH than in LCH and suggest that apoptosis might be a cause of the spontaneous involution of ICH.

Adolescent↗