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Biomedical subjects

N Yashiro

Publications and source records attributed to N Yashiro.

At least 19 recordsLinked to original sources
PubMed2006

MR findings of granulocytic sarcoma of the breasts.

We report a case of isolated extramedullary relapse of acute myeloid leukaemia (AML) that presented as granulocytic sarcoma of both breasts, with no other signs of relapse even in the bone marrow. The T2 weighted coronal images on MR showed both multiple ill-defined heterogeneous hyperintense masses relative to breast parenchyma; these masses were seen also with a visual washout enhancement. Pathohistological study showed infiltration by myeloblasts, which were relatively uniform in appearance, featuring round or oval nuclei and a small cytoplasm. After chemotherapy and radiotherapy, both breast masses disappeared on MR images. Although the MR findings of granulocytic sarcoma were indistinguishable from those of multicentric carcinoma and malignant lymphoma, the MR images were useful for evaluating and monitoring responses to the treatments, as well as for detecting non-palpable relapsed tumours.

Breast Neoplasms↗
PubMed2002

High signal of the striatum in sporadic Creutzfeldt-Jakob disease: sequential change on T2-weighted MRI.

The object of this study is to describe the sequential change of high signal of the striatum on T2-weighted MRI in sporadic Creutzfeldt-Jakob disease (CJD). Three cases of autopsy-proven sporadic CJD and a total of 18 serial MR images are included in this study. The degree of high signal of the striatum on T2-weighted MRI was evaluated by two neuroradiologists and divided into four grades by mutual agreement. Initial MRI of all three cases showed a slightly high signal of the bilateral striatum, and the conspicuity of the high signal became more prominent as the disease progressed. In each case the pathological change of striatum and globus pallidus was compared with the high signal on the last MR image.

Aged↗
PubMed2001

Granulomatous slack skin: an ultrastructural study.

BACKGROUND: Granulomatous slack skin is a rare lymphoproliferative disorder characterized clinically by gradual development of pendulous folds of lax erythematous skin in flexural areas, and histologically by non-necrotizing granuloma, with numerous multinucleated giant cells, mononuclear histiocytes, and atypical lymphocytes associated with loss of elastic fibers. Although there are many reports describing the histological and immunophenotypic features of this disease, only a few have described the ultrastructural features. METHODS: Here we report a case of granulomatous slack skin and describe the ultrastructural findings. RESULTS AND CONCLUSION: We could detect some previously not noted abnormal findings in multinucleated giant cells, histiocytes, and atypical lymphocytes.

Adult↗
PubMed1997

Aging of the population in Japan and its implications to the other Asian countries.

"The speed at which Japan's population is aging is mainly a result of its rapid economic development, which is common to many other East Asian countries. Two aspects of the aging of the population are an increasing share of the elderly and a declining labor force. The larger the number of elderly, the more the transfer of income between generations, and the fiscal burden rises. The shrinking workforce will lower the economic growth directly, and indirectly through the falling saving ratio. However, the negative impacts from aging can largely be offset by stimulating participation of older persons in the labor force."

Adult↗
PubMed1996

Detection of lysyl oxidase gene expression in rat skin during wound healing.

Lysyl oxidase (LOX) initiates the crosslinking of the lysine-derived aldehyde and plays an essential role in maturation of collagen, for example in wound healing. Although the activity of this enzyme has been examined in various disorders, and a further intriguing aspect of the relationship between LOX and tumorigenesis has recently emerged, its gene expression pattern in tissues is still unknown. We examined LOX gene expression during wound healing in rat skin. In addition, type III collagen gene expression was studied to determine the formation of fibrils. The LOX mRNA level reached a peak by day 3 after injury, which was earlier than that of type III collagen, and continued at a high level until day 22. The type III collagen mRNA level began to rise from day 3 and had increased intensely by day 22. In situ hybridization revealed grains corresponding to LOX mRNA in the fibroblasts of the granulomatous tissue. These results suggest that LOX is produced before collagen synthesis in preparation for crosslinking in the early phase of wound healing.

Animals↗
PubMed1995

Increased expression of lysyl oxidase in skin with scleroderma.

Lysyl oxidase initiates cross-linkage of collagen and elastin by catalysing the formation of a lysine-derived aldehyde. In order to study cross-linking in scleroderma, we used monoclonal antibodies to lysyl oxidase to determine the localization of this enzyme in systemic and localized scleroderma, and compared the distributions obtained with that in normal skin. Using an indirect immunofluorescent antibody method and an avidin-biotinylated enzyme complex method, 11 cases of diffuse type of systemic scleroderma and seven cases of localized scleroderma were studied. In the oedematous stage of systemic scleroderma, intracellular and extracellular lysyl oxidase were remarkably increased in the dermis, particularly in groups around blood vessels. In the sclerotic stage of systemic scleroderma, lysyl oxidase was detected intracellularly in fibroblasts and extracellularly among collagen bundles between the lower dermis and the subcutaneous fat tissue. In localized scleroderma, a marked increase in lysyl oxidase was observed in mononuclear cells and fibroblasts near blood vessels in the lower dermis and in the subcutaneous fat tissue, in addition to the extracellular deposits between collagen bundles. The increase in lysyl oxidase in localized scleroderma was much more common than in the oedematous stage of systemic scleroderma. These findings indicated that intracellular and extracellular expression of lysyl oxidase expression was greater in sclerodermatous skin than in normal skin.

Adolescent↗
PubMed1994

Primary anaplastic large-cell lymphoma of the skin. A case report suggesting that regressing atypical histiocytosis and lymphomatoid papulosis are subsets.

A patient with primary anaplastic large-cell lymphoma of the skin with characteristic clinical findings is described. The diagnosis was made on the basis of histologic and immunohistochemical findings. The phenotype of the tumor cells was not determined, but rearrangement of the T-cell receptor beta gene indicated that the tumor was of T-cell lineage. Despite high-grade malignancy of the tumor cells, the patient unexpectedly had a benign clinical course. The findings in this case suggest that regressing atypical histiocytosis and lymphomatoid papulosis type A are subsets of anaplastic large-cell lymphoma.

Abdominal Neoplasms↗
PubMed1994

Immunohistochemical localization of lysyl oxidase in normal human skin.

Lysyl oxidase (EC 1.4.3.13), a copper-dependent enzyme which catalyses the formation of aldehyde cross-links, and acts primarily on collagen and elastin, is known to be increased during wound healing and in fibrotic disorders including liver cirrhosis and atherosclerosis, and to be decreased in some hereditary connective tissue diseases and in malignant cell lines. A recent study showed that lysyl oxidase might possess tumour suppressor activity as an antioncogene for ras. Little is known about the localization of this enzyme in human skin. In this study, we determined immunohistochemically the localization of lysyl oxidase in normal skin of young and elderly subjects obtained from sun-exposed and unexposed regions of the body. All skin samples tested had similar distributions of lysyl oxidase. The enzyme was present both extracellularly and intracellularly. Extracellularly, a few granular aggregates of immunoreactants were observed along collagen and elastic fibres. These granules were more common in the adventitial portion of the dermis than in the reticular portion. Of all sun-exposed and unexposed regions studied, the skin of the face displayed the greatest amount of extracellular immunoreactants. Immunopositive granules were observed intracellularly in fibroblasts, vascular endothelial cells, sweat glands, sebaceous glands, arrector pili muscles and some keratinocytes. These findings provide evidence that, as suggested in recent reports, lysyl oxidase may have a variety of intracellular functions.

Adolescent↗
PubMed1993

Detection of human T-cell lymphotropic virus type-1 proviral DNA in the saliva of an adult T-cell leukaemia/lymphoma patient using the polymerase chain reaction.

We report a case of adult T-cell leukaemia/lymphoma (ATLL), in whom the polymerase chain reaction (PCR) on genomic DNA from saliva demonstrated the monoclonal integration of human T-cell lymphotropic virus type-1 (HTLV-1) proviral DNA in lymphocytes in the saliva. These results provided evidence of the possibility of saliva-borne transmission of HTLV-1.

Base Sequence↗
PubMed1993

Comparison of mutations of ras oncogene in human pancreatic exocrine and endocrine tumors.

BACKGROUND: Ras oncogene mutations have been found in many human cancers; however, pancreatic endocrine tumors have rarely been studied. The purpose of this study was to analyze ras mutations in pancreatic endocrine tumors and to compare these results with the incidence of ras mutations in pancreatic exocrine cancers studied in our laboratory. METHODS: Ras oncogene mutations were studied in 33 foregut endocrine tumors (pancreatic 31, duodenal submucosa 2). Eleven were insulinomas, 12 gastrinomas, 2 glucagonomas, and 11 others were nonfunctioning islet cell carcinomas. Thirteen were benign and 20 were malignant. These were compared with 65 pancreatic exocrine cancers. Tumors were microdissected from paraffin-embedded sections. DNA was extracted and amplified by polymerase chain reaction. Mutations were detected by a oligonucleotide hybridization method with sequence-specific phosphorus 32-radiolabeled probes. RESULTS: No ras mutations were identified among the 33 pancreatic endocrine tumors. In contrast, 51 of 65 (78.5%) pancreatic exocrine cancers exhibited a ras mutation. Fifty were K-ras mutations and one unusual tumor exhibited a N-61 ras mutation. CONCLUSIONS: Ras oncogene mutations do not play a role in the tumorigenesis of pancreatic endocrine tumors.

Adenoma, Islet Cell↗
PubMed1991

Squamous cell carcinoma developing in epidermolysis bullosa dystrophica.

Two patients with epidermolysis bullosa dystrophica recessiva who had squamous cell carcinoma are presented. Case 1 is a 40-year-old woman who had ulcers on her left lower leg. Case 2 is a 42-year-old man who had a tumor on his left first toe. Wide surgical excision with skin coverage by autograft was performed in case 1. Amputation of the toe in case 2 was performed. A review of the cases of epidermolysis bullosa dystrophica associated with cancer reported in Japan is also presented.

Adult↗
PubMed1990

[Transarterial embolization of metastatic pheochromocytoma].

We successfully controlled hypertension of a 48-year-old female by embolizing metastatic pheochromocytoma of the liver. Although transarterial embolization of the hepatic artery was uneventful, the patient soon developed severe hypertension and tachycardia which were controlled medically. Symptoms subsided within 10-20 days. Follow-up CT showed reduction of the liver mass.

Adrenal Gland Neoplasms↗
PubMed1990

[Renal lymphoma; six cases].

Six patients had nine kidneys with lymphoma. Five patients (83%) had non-Hodgkin lymphoma, and three (50%) bilaterally. There were multiple nodules in four kidneys (44%). The lesions were changeful in the course. Gallium scintigraphy showed abnormal uptakes. Magnetic resonance imaging was examined in one case. The lesions were hypovascular in the angiographies. Inflammation is one of the different diagnosis.

Adult↗
PubMed1989

Well-defined, dense and continuously spreading enhancement on single level dynamic CT of the liver: a characteristic sign of hepatic cavernous haemangioma.

The findings of single-level dynamic CT were reviewed in 83 lesions of cavernous haemangioma, 90 lesions of hepatocellular carcinoma, 29 lesions of metastatic tumour and 10 lesions of other hepatic masses in order to see the validity of characteristic findings of hepatic cavernous haemangioma. Well-defined, dense and continuously spreading enhancement (WDCSE) being defined as follows: 1. well-defined contour of enhanced area, 2. the density of maximally enhanced area almost same as that of enhanced vessel and 3. continuously spreading enhancement continuing over 20 seconds, WDCSE was noted definitely in 47 lesions of cavernous haemangioma alone (57%; 77% over 3 cm, 64% between 2 and 3 cm, and 19% under 2 cm in diameter) and, suggestively in 16 lesions of cavernous haemangioma and 4 lesions of hepatocellular carcinoma, but in no lesions of other tumours. WDCSE did not show a high sensitivity for cavernous haemangioma but it had a 100% positive predictive value for the disease. If WDCSE is noticed even in oncology patients with hepatic mass, no further examination may be necessary.

Carcinoma, Hepatocellular↗
PubMed1989

Small hepatocellular carcinoma and cavernous hemangioma: differentiation with dynamic FLASH MR imaging with Gd-DTPA.

Forty patients with hepatocellular carcinoma (HCC) (n = 22) or cavernous hemangioma (diameter, 3 cm or less) (n = 18) were examined with serial magnetic resonance (MR) imaging at 1.5 T with the fast low-angle shot (FLASH) technique and an intravenously administered bolus injection of 0.05 mmol/kg Gd-DTPA. Two images per minute were obtained for 5 minutes, and one per minute thereafter until about 10 minutes. Dynamic MR studies revealed five criteria for differentiating these tumors. With HCC there was a hyperintense mass before contrast material enhancement (32%), peak contrast enhancement at about 10 seconds after injection (55%), slight to moderate peak contrast enhancement (73%), absent or minimal delayed enhancement (100%), and, at morphologic study, a capsule or nodules-in-nodule appearance (59%). With hemangioma there was a hypointense mass before contrast enhancement (72%), peak contrast enhancement more than 2 minutes after injection (72%), marked peak contrast enhancement (83%), moderate to marked delayed enhancement (100%), and, at morphologic study, spreading phenomenon (39%). Seventy-seven percent of HCCs and 83% of hemangiomas satisfied three or more criteria and thus could be differentiated from each other with certainty.

Adult↗
PubMed1989

[Is T2-weighted imaging reliable in the differential diagnosis of an adrenal mass? Dependence of signal intensity on the size of tumors].

We reviewed T2-weighted images of 41 adrenal tumors. There were 25 adenomas and 16 non-adenomas. We compared the signal intensity of the adrenal tumors with that liver and classified the tumor/liver intensity ratio (TLR) into five categories; very low (much less than), low (less than), iso-intense (=), high (greater than), and very high (much greater than). The size of adenomas in diameter ranged between 8 mm-50 mm. TLR of 92% of adenomas less than 20 mm (13 cases) were (less than) or (=); when adenomas exceeded 20 mm (12 cases), 75% were (greater than) or (much greater than). TLR of non-adenomas all (greater than) or (much greater than).

Adenoma↗