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Biomedical subjects

M Shintaku

Publications and source records attributed to M Shintaku.

70 records · Page 4Linked to original sources

An autopsy case of purulent mycobacterial meningitis in AIDS.

The patient was a 46-year-old male hemophiliac who died of acute mycobacterial meningitis associated with AIDS (acquired immune deficiency syndrome). Autopsy revealed severe basal meningitis which was characterized by an infiltration of numerous polymorphonuclear leukocytes. Severe mural inflammation of the subarachnoid arteries was noted, and innumerable acid-fast bacilli were demonstrated. Epithelioid cell granulomas were not found in the meningeal lesion. The lungs, liver, spleen, and bone marrow contained many epithelioid cell granulomas with caseous necrosis. Massive proliferation of swollen histiocytes could not be identified in any organ. The absence of epithelioid cell granulomas in the meningeal lesion indicate a severe impairment of cell-mediated immunity in the patient; this anergic type of lesion is one of the characteristics of tuberculosis occurring in association with terminal AIDS.

AIDS Dementia Complex↗

Cytomegalovirus vasculitis accompanied by an exuberant fibroblastic reaction in the intestine of an AIDS patient.

A case of cytomegalovirus (CMV) vasculitis in the intestine of a patient with acquired immune deficiency syndrome (AIDS) is reported. The distal jejunum and ileum had multiple well-demarcated mucosal ulcers and microscopic examination revealed an unusual, exuberant fibroblastic proliferation in the ulcer base. Amidst these fibroblasts, there were several small blood vessels of which the endothelial cells contained cytomegalic inclusion bodies. The lesion showed a Kaposi's sarcoma-like appearance, but spindle cells were negative in immunostaining for factor VIII-related antigen or Ulex europaeus agglutinin-1. Although the CMV infection was observed in almost all organs, the exuberant fibroblastic proliferation seen in the intestine was not found in other organs. This lesion might represent a peculiar reaction of the immunologically compromised host to the CMV in the intestinal blood vessels.

Acquired Immunodeficiency Syndrome↗

Nucleotide sequence and evolutionary relationships of cucumber mosaic virus (CMV) strains: CMV RNA 3.

The nucleotide sequence of RNA 3 of two subgroup I strains of cucumber mosaic virus (CMV), Fny-CMV and M-CMV, was determined and compared at both the nucleic acid and protein level with the previously determined, corresponding (partial) sequences of RNA 3 of five other subgroup I strains: C-CMV, D-CMV, I17F-CMV, O-CMV and Y-CMV. Fny-CMV RNA 3 is composed of 2216 nucleotides (nt) and M-CMV RNA 3 2214 nt. Both RNAs contain two open reading frames, the 3a gene and the coat protein gene. These RNAs showed very little nucleotide sequence divergence, either from each other or from the five other subgroup I strains. The nucleotide sequence variation observed was two to 13 differences in the 120 to 123 nt 5' non-translated regions, six to 17 differences in the 840 nt 3a genes, two to 15 differences in the 296 to 299 nt intergenic regions, three to 25 differences in the 657 nt coat protein genes and two to 10 differences in the 299 to 303 nt 3' non-translated regions. Protein sequence similarity was also high, with one to four differences in the 279 amino acids of the 3a proteins and two to 13 differences in the 218 amino acids of the coat proteins. Limited nucleotide sequence variation among nine strains of CMV was also shown using an RNA protection assay and a probe specific for Fny-CMV RNA 3. The limited variation shown by RNA 3 of strains of CMV with different passage histories, isolated in different countries over a 50 year period, suggests that the maintenance of the highly conserved nucleotide sequence may be important for other viral RNA functions or interactions.

Amino Acid Sequence↗

Giant cell fibroblastoma. A case report.

A case of giant cell fibroblastoma occurring in the knee of a 16-month-old girl is reported. The ill-defined subcutaneous tumor measuring 2 x 2 cm was composed of diffusely proliferating spindle-shaped tumor cells with scattered, atypical multinucleated giant cells in a myxoid or collagenous background and irregularly branching sinusoid-like tissue spaces. In addition to floret-type giant cells, a few osteoclast-like giant cells were present in a cellular area where tumor cells were focally arranged in a storiform pattern. Immunohistochemically, the tumor cells gave positive reactions for only vimentin and actin. In spite of the high recurrence rate of this type of tumor, the course of the patient after excision of the tumor has been uneventful. It is important to distinguish this rare, peculiar fibrous tumor from other soft tissue tumors including some sarcomas.

Female↗

Generalized sarcoidlike granulomas with systemic angiitis, crescentic glomerulonephritis, and pulmonary hemorrhage. Report of an autopsy case.

A 19-year-old woman showed rapidly progressive renal and respiratory failure and died after a short clinical course. The autopsy revealed that death was due to crescentic glomerulonephritis and pulmonary hemorrhage. The intrathoracic lymph nodes, lungs, kidneys, and other organs contained numerous epithelioid granulomas, some of which had foci of central coagulative necrosis. The aorta, its major branches, and small- to medium-sized vessels of various organs also had multiple areas of granulomatous angiitis. This is, to our knowledge, the first report of such autopsy findings. A discussion of the etiopathogenesis of the disease is presented.

Adult↗

Cerebrovascular lesions in acquired immune deficiency syndrome (AIDS).

Cerebrovascular lesions were seen in 28 of 83 cases (34%) of acquired immune deficiency syndrome (AIDS). Cerebral hemorrhage was noted in 4 cases, cerebral infarct in 23 cases and both in 1 case. Cerebral hemorrhage was in various locations such as intraparenchymal, subarachnoid space, subdural space and epidural space. Large, clinically evident hemorrhage was noted in 2 of 5 cases and bleeding tendency was noted in 2 cases. Most of the 24 cases with cerebral infarcts were not clinically evident; they were multiple, small and mainly involved the striatum, cerebral cortex and brain stem. Mural thickening of occasional small blood vessels was seen in 12 of the cases (50%) with infarcts. Other changes in blood vessels included vasculitis in one case and perivascular lymphocytic infiltration in another. In addition to thrombo-embolism and systemic ischemia/anoxia, these blood vessel changes may have a role in the development of cerebral infarcts in AIDS.

Acquired Immunodeficiency Syndrome↗

Malignant ameloblastoma with pulmonary metastasis and hypercalcemia. Report of an autopsy case and review of the literature.

A case of malignant ameloblastoma with hypercalcemia in a 67-year-old Japanese woman is presented. The tumor of the maxilla was removed and diagnosed as a follicular ameloblastoma. The tumor recurred in the lower orbita-zygoma region, and multiple tumors of the lungs and hypercalcemia were detected eight months after the second operation. The recurrent tumor resembled the primary tumor but was less well differentiated. Autopsy revealed widespread lung metastasis of the malignant ameloblastoma, nephrocalcinosis, and sigmoid colon cancer. Histologic examination showed the metastatic ameloblastoma to be composed of nests and strands of basaloid and spindle-shaped cells surrounded by columnar cells arranged in palisade formation, with focal areas of squamous differentiation and occasional cystic degeneration. Only two cases of malignant ameloblastoma with hypercalcemia have previously been reported. This is the first case of malignant ameloblastoma with hypercalcemia and sigmoid colon cancer. In addition, prostaglandin E2 assay revealed that ameloblastoma produces prostaglandin E2, which results in hypercalcemia.

Aged↗

[Fine structure of glioblastoma multiforme with "adenoid formation"].

Glioblastoma multiforme with "adenoid formation" (Kepes) in the temporal lobe of a 70 year old man was presented. In addition to the classical features of glioblastoma multiforme, the tumor presented a pattern of anastomosing trabeculae of polygonal cells, mimicking epithelial tubules, in a myxoid stroma. On electron microscopic examination, the tumor cells were devoid of well-developed cytoplasmic processes. The cytoplasm of some tumor cells contained glycogen particles and lipid vacuoles in addition to usual organelles. The cell surface was partly covered by basal lamina associated with half desmosomes and had occasional filopodia-like cytoplasmic projections. A few tumor cells contained a dense intracytoplasmic accumulation of glial filaments. Intercellular junctional complexes were poorly developed. There was no evidence of differentiation of tumor cells toward ependymal cells or epithelial cells. These electron microscopic findings suggest that this tumor is predominantly composed of immature astrocytes. In spite of a superficial resemblance to adenocarcinoma on light microscopy, the tumor cells are devoid of the differentiating features of epithelial neoplasms, and their ultrastructure is essentially similar to that of glioblastoma multiforme.

Astrocytes↗

Sclerosing stromal tumor of the ovary: MRI.

The MR and pathologic findings of a case of sclerosing stromal tumor (SST) are presented. MR findings reflecting pathological features of SST include pseudolobulation, which consists of low-intensity nodules set against high-intensity stroma on T2-weighted images, and striking enhancement on postcontrast images.

Adult↗

Increased diameter of demyelinated axons in chronic multiple sclerosis of the spinal cord.

In an autopsied case of chronic multiple sclerosis, many axons in some demyelinated plaques of the spinal cord had remarkably increased diameters and reduced argentophilia. The increase in axonal diameter extended for some distance and was restricted to the demyelinated areas. A review of 22 autopsy cases of chronic multiple sclerosis revealed similar findings in the plaques of the spinal cord in seven cases. They were also noted in the brain but much less frequently. On electron microscopy, the neurofilaments in these enlarged demyelinated axons were not closely packed but were separated by an increased amount of electron-lucent axoplasm. It is thought that this finding may be a manifestation of increased water content in the axoplasm secondary to increased permeability of the demyelinated axolemma.

Aged↗

Nuclear pseudoinclusions in angiomyolipoma of the kidney. A case report.

BACKGROUND: Fine needle biopsy has been utilized for the preoperative diagnosis of angiomyolipoma of the kidney. However, the spectrum of diverse nuclear morphology shown by the constituent smooth muscle cells of angiomyolipoma has not been fully elucidated. CASES: An angiomyolipoma was found incidentally in the left kidney of an asymptomatic, 57-year-old woman, and nephrectomy was performed. The tumor was composed predominantly of smooth muscle cells occasionally showing atypical nuclear features. Small aggregates of adipocytes were also found. Direct stamp specimens of the tumor revealed plump, spindle-shaped smooth muscle cells, and the nuclei of many of these cells contained large pseudoinclusions (cytoplasmic invaginations). Histologic review of an additional four cases of renal angiomyolipoma further revealed the frequent occurrence of nuclear pseudoinclusions in smooth muscle cells of the tumor. CONCLUSION: Nuclear pseudoinclusions on fine needle aspiration cytology of renal angiomyolipoma have not received adequate attention. We showed that this finding is a rather common nuclear feature in angiomyolipoma. It is presumably one of the manifestations of nuclear pleomorphism frequently seen in smooth muscle cells of angiomyolipoma and should not be considered an indication of malignancy.

Angiomyolipoma↗

Astrocytoma with angiomatoid vascular proliferation ("angiomatous astrocytoma").

We report a surgical case of unusual anaplastic astrocytoma which was accompanied by an exuberant proliferation of abnormal blood vessels with features resembling those of capillary telangiectasis or cavernous angioma. The patient was a 39-year-old man, who presented with a generalized convulsive seizure, and neuroradiological examination revealed a tumor in the left frontal lobe. The resected tumor showed the features of an anaplastic astrocytoma, grade 3. The proliferation of abnormal blood vessels with dilated lumina and thin walls was seen throughout the tumor, and in the central area these vessels were densely packed and almost replaced the neoplastic astrocytic tissue. Although these dense vascular aggregates in the central area closely simulated capillary telangiectasis or cavernous angioma, they were considered to be of a reactive nature. The term "angiomatous astrocytoma", which is analogous to angiomatous meningioma, seemed to be the most appropriate for the present tumor.

Adult↗