Biomedical subjects

T Hirose

Publications and source records attributed to T Hirose.

At least 973 records · Page 54Linked to original sources

PubMedDate not supplied

Ultrastructural features of pleomorphic xanthoastrocytoma: a comparative study with glioblastoma multiforme.

Eighteen tumors (15 cases) were ultrastructurally examined and compared to 11 examples of glioblastoma multiforme (GBM) [to determine the cellular nature of pleomorphic xanthoastrocytoma (PXA).] PXA, as well as GBM, were principally composed of pleomorphic astrocytes containing numerous intermediate filaments. Lipid droplets, lysosomes, and basal laminas were more numerous and fully developed in PXA, but were not specific to the tumor. Aggregates of secondary lysosomes, light microscopically evident as eosinophilic granular bodies, and ribosome-lamella complexes were exclusively seen in PXA. Also noted in PXA were centrioles, occasional Rosenthal fibers, hemidesmosomes in small number, rudimentary cell junctions, and interstitial calcifications. In addition to astrocytic constituents, 20% of PXA contained cells with neuronal features, as evidenced by the presence of dense-core granules, microtubules, and clear vesicles. In contrast, GBMs consisted solely of astrocytic cells. In the present study, the salient ultrastructural findings of PXA were largely degenerative in nature, including numerous lipid droplets and secondary lysosomes, as well as basal laminas, ribosome-lamella complexes, and occasional neuronal differentiation. The presence of basal lamina does not necessarily imply a histogenetic derivation from subpial astrocytes, in that it is also a common feature of GBM. Given the occurrence of biphenotypic, glioneuronal differentiation in some cases, PXA may be derived from a neuroepithelial stem cell. The authors conclude that PXA is fundamentally an astrocytic tumor, albeit one with a significant tendency to undergo neuronal differentiation.

Astrocytes↗

PubMedDate not supplied

Calcifying fibrous pseudotumor: an ultrastructural study.

To clarify the pathogenesis of calcification in calcifying fibrous pseudotumor (CFT), the lesion arising in the chest wall of a 16-month-old boy was ultrastructurally investigated. Fibroblasts were surrounded by large amounts of collagen fibrils. The dystrophic and psammomatous calcifications were observed as electron-dense amorphous masses and laminated bodies, respectively, within the cytoplasm of fibroblasts and in the collagenous stroma. The degeneration of cytoplasm seemed to be an initial event of intracytoplasmic calcification. Extracellular calcified substances often abutted to fibroblasts. Fibroblasts may play an important role in both intracellular and extracellular calcifications of CFT.

Calcinosis↗

PubMedDate not supplied

Bacteriologic studies on Neisseria gonorrhoeae isolated in Sapporo, Japan: investigation of beta-lactamase production and auxotypes.

The authors studied the annual incidence of isolation of penicillinase-producing Neisseria gonorrhoeae (PPNG) strains among the total number of strains of N. gonorrhoeae (1,401 strains) that were isolated in Sapporo, Japan during 1980-1989. During the first half of the 1980s, there was a tendency for PPNG to increase, and the peak incidence was 23.9% in 1985. Thereafter, the incidence of PPNG decreased to an isolation rate of 6.3% in 1989. In addition, the auxotypes of 592 of 1,401 isolated strains of Neisseria gonorrhoeae were studied during three periods: 1980-1985, 1986-1987, and 1988-1989. Among the 592 strains, 315 strains were tested for sensitivity to the action of amoxicillin. In the 1988-1989 period, the auxotype showed an increasing incidence of the auxotype that requires arginine, hypoxanthine, and uracil (i.e., AHU), whereas the proto- and pro-types decreased in incidence. The AHU strains showed higher sensitivity to amoxicillin administration compared with the proto- and pro-strains.

Amoxicillin↗

PubMedDate not supplied

Epidemiologic study of Chlamydia trachomatis infection in pregnant women.

GOAL OF THE STUDY: The presence of Chlamydia trachomatis in the cervical canal was investigated in 10,980 married pregnant women and 1,792 unmarried pregnant women who underwent artificial abortions in Hokkaido. STUDY DESIGN: Cervical canal smears were screened for C. trachomatis in pregnant patients. RESULTS: In the married women, the detection rate of C. trachomatis was 5.6% (615 of 10,980 cases). In the unmarried women, the detection rate of C. trachomatis was 15.2% (272 of 1,792 cases). Stratification of the data on the detection of C. trachomatis as a function of the subjects' age showed that, for both the married and the unmarried women, the detection rate increased as the age of the subjects decreased. Analysis of the detection rate of C. trachomatis as a function of the year revealed that it had not changed since 1986. CONCLUSIONS: The findings in this study show that there has been an epidemic of asymptomatic C. trachomatis infections in Hokkaido, especially in young women.

Adult↗

PubMedDate not supplied

Melanocytoma of the foramen magnum.

This report concerns a 66-year-old man with a melanocytoma arising at the foramen magnum. Magnetic resonance imaging disclosed a well-circumscribed tumor extending from the medulla oblongata to C1 with gadolinium enhancement. A heavily pigmented tumor located under the leptomeninges was removed surgically. Although the patient died 8 months later of renal cell carcinoma, no recurrence or metastasis of the melanocytoma was detected by radiographic examination. Microscopically, the resected tumor was composed of polygonal to spindle-shaped cells containing large amounts of melanin. The bland nuclei of the tumor cells were of uniform size. No mitotic figures were seen. The tumor cells were positively immunostained for S-100 protein and by antibody HMB-45. They were not stained using the Ki-67 (MIB-1) antibody, indicating low proliferative activity. The ultrastructural examination revealed numerous mature melanosomes and basal laminae surrounding nests of cells. The tumor was diagnosed as a melanocytoma on the bases of its microscopic features and the lack of Ki-67 immunoreactivity. The ultrastructural and immunohistochemical features of melanocytomas are distinct from those of meningiomas. It is likely that melanocytomas and melanotic schwannomas represent opposite extremes of the continuous spectrum of neuroectodermal tumors derived from the neural crest.

Aged↗

PubMedDate not supplied

Malignant mixed müllerian tumor of primary mesenteric origin.

Malignant mixed müllerian tumor (MMMT) is a rare tumor. A literature search revealed very few reports on MMMT, especially those arising in the peritoneum. We recently encountered an MMMT of primary mesenteric origin associated with left fallopian tube cancer. There have been no previous reports about its occurrence in the mesentery. When cases of peritoneal MMMT were reviewed, the disease was found to be associated with synchronous or metachronous gynecologic tumors of müllerian duct origin (ie, ovarian tumors, primary serous carcinoma of the peritoneum, fallopian tube cancer, endometrial cancer, and adenocarcinoma of the cervix) in 12 out of 32 patients (37.5%). Peritoneal MMMT are frequently associated with gynecologic tumors.

Adenocarcinoma↗

PubMedDate not supplied

Bactericidal effect of levofloxacin on strains with equal susceptibility in an in vitro urinary bladder model.

The in vitro bactericidal effects of therapeutic concentrations of levofloxacin (LVFX) on clinical isolates of Pseudomonas aeruginosa and Enterococcus faecalis were assessed. Starting from 10(7) CFU/ml, the bacterial count was determined serially during the exposure to LVFX present at concentrations automatically simulated to its clinically achievable urinary levels at the recommended dosage (100 mg 3 times daily). An isolate of P. aeruginosa for which the MIC of LVFX was 16 microgram/ml was completely eradicated after 10 h of exposure to LVFX. On the other hand, 40 h of exposure to LVFX were required for complete eradication of an isolate of E. faecalis with equal susceptibility, although the bacterial count was rapidly reduced to 10(2) CFU/ml in the early phase of the exposure. It was concluded that LVFX exerts a more potent bactericidal effect on P. aeruginosa than on E. faecalis despite a similar susceptibility of these organisms to LVFX.

Anti-Infective Agents, Urinary↗

PubMedDate not supplied

Bactericidal activity of gatifloxacin (AM-1155) against Pseudomonas aeruginosa and Enterococcus faecalis in an in vitro bladder model simulating human urinary concentrations after oral administration.

The bactericidal activity of gatifloxacin, a new 6-fluoro-8-methoxy quinolone, was determined in a dynamic in vitro model mimicking complicated lower urinary tract infection. Strains of Pseudomonas aeruginosa and Enterococcus faecalis with different susceptibility were exposed to changing gatifloxacin concentrations, simulating human urinary concentrations afer oral treatment with 200 mg twice daily for 3 consecutive days. Bacterial numbers of P. aeruginosa (minimal inhibitory concentrations, MIC: < or =32 microg/ml) and of E. faecalis (MIC: 16 microg/ml) were reduced to undetectable levels during exposure. For the strains with lower susceptibility, gatifloxacin showed bactericidal activity, but eradication was not complete. Thus, in a complicated urinary tract infection model, breakpoint MICs of gatifloxacin for uropathogenic organisms were presumed to range from 16 to 32 microg/ml. At least 86% of recent clinical isolates of P. aeruginosa and E. faecalis were inhibited at its breakpoint MIC. These results suggest that gatifloxacin may be useful in the treatment of urinary tract infections.

Administration, Oral↗

PubMedDate not supplied

Changes in susceptibility of Pseudomonas aeruginosa to gatifloxacin and carbapenem in an in vitro urinary bladder model.

To study the changes of bacterial susceptibility during exposure to antimicrobials, the respective minimal inhibitory concentrations (MICs) of 50 colonies from each of various bacterial test strains were determined in an experimental system using an in vitro urinary bladder model. The MICs of gatifloxacin and meropenem for Pseudomonas aeruginosa strains were not homogeneous before exposure to the drugs. The MICs of the strains examined reflected only that of their dominant population. When starting from 10(7)CFU/ml, the bacterial count was determined serially during exposure to gatifloxacin or meropenem in therapeutic urinary concentrations. The MIC of the less susceptible population of each strain was changed serially to a higher one. The more susceptible strains were eradicated before the change of the MIC. The bacteria originally consisted of strains having heterogeneous susceptibility to drugs, in which major strains had susceptibility expressed by the MIC and minor ones had a higher or lower MIC. This heterogeneity may be responsible for the change of susceptibility in strains after exposure to the drugs.

Anti-Infective Agents↗

PubMedDate not supplied

Bronchial brushing cytology features of primary malignant fibrous histiocytoma of the lung. A case report.

BACKGROUND: Malignant fibrous histiocytoma (MFH) of the lung is rare. Early diagnosis is very important because of its poor prognosis. Long-term survivors of pulmonary MFH are patients who had surgical resection. When the patient can undergo surgery after a prompt diagnosis, the prognosis improves more than with other therapy. However, it is not easy to establish the diagnosis of thoracic MFH. In general, the small fragments from bronchial or percutaneous transthoracic fine needle aspiration (FNA) biopsies are inadequate for cytologic or pathologic analysis. Bronchial brushing cytology is greatly superior to FNA cytology because one can obtain a large amount of cells. Therefore, bronchial brushing cytology may play a useful role in diagnosis when endobronchial involvement is found. CASE: A 65-year-old female was admitted with a cough, yellow sputum and exertional dyspnea. A chest roentgenogram showed a 12 x 12-cm mass in the left lung field. Bronchial brushing cytology revealed many fibroblastlike, histiocytelike, bizarre and multinucleated giant cells in a background of necrosis. Atypical mitotic figures were also found. The cytologic findings strongly suggested MFH. Although the pathologic findings from FNA biopsy showed storiform clusters structured by pleomorphic, fibroblastlike cells with bizarre nuclei and mitotic figures, the material was too small to diagnose it definitively. Six months later the patient died. An autopsy confirmed the diagnosis of MFH: the typical storiform clusters were composed of many fibroblastlike and histiocytelike cells that were positive for CD68 (PGM1) antibody. CONCLUSION: Bronchial brushing cytology may be a useful method for early, definitive diagnosis of MFH. The presence of pleomorphic, spindle-shaped fibroblastlike and histiocytelike cells with the clusters showing a storiform pattern may permit the diagnosis of MFH.

Aged↗

PubMedDate not supplied

Treatment of acute myeloblastic leukaemia in a patient with Bombay blood type: a case report.

A 62-year-old female was admitted to our hospital with suspected acute leukaemia and after investigation we diagnosed acute myeloblastic leukaemia (AML-M1). The patient's blood type was found to be the very rare Bombay type and surveillance of her relatives showed the same blood type in her male cousin on her mother's side. Alongside chemotherapy the patient received 4000 ml of frozen Bombay-type red cells, 1400 ml of concentrated red cells in manitol adenine phosphate solutions and 360 units of type O concentrated platelets without marked effects. The anti-H antibody was initially at 128 dilution but for unknown reasons increased to 2048 dilution after remission of AML-M1. About 3 months after hospitalization the patient died of Cryptococcus neoformans pneumonia despite strict precautions against infection. Although AML-M1 is a common adult leukaemia and is chemosensitive to anti-leukaemic drugs, neither AML-M1 in a patient with Bombay-type red cells nor its treatment with chemotherapy and transfusion with type Oh frozen red cells have previously been reported.

Antineoplastic Agents↗

PubMedDate not supplied

Malignant fibrous histiocytoma with epithelial differentiation?

A case of recurrent soft part sarcoma with focal areas showing epithelial differentiation in the right thigh in a 78-year-old woman is reported. The primary tumor consisted of myxoid areas and solid areas, in which relatively uniform epithelioid tumor cells were arranged in sheets, whereas pleomorphism and a storiform pattern appeared in the recurrent tumors. Thus this tumor was suspected to be a malignant fibrous histiocytoma. However, further studies showed unexpected ultrastructural and immunohistochemical features. Cytokeratin immunoreactivity and tonofilamentlike structures probably indicated epithelial differentiation of some tumor cells. From the clinical and histological findings, this tumor should be identified as a malignant fibrous histiocytoma with phenotypic expressions of epithelial cell.

Aged↗

PubMedDate not supplied

Heterogeneity of malignant schwannomas.

Six malignant schwannomas were studied by electron microscopy and immunohistochemistry for S-100 protein at the light and electron microscopic levels to clarify the nature of the tumor cells. Three tumors (group A) were composed of poorly differentiated tumor cells and showed no immunoreactivity for S-100 protein. One tumor (group B) was composed of perineurial cells that were S-100 protein-negative. Two tumors (group C) consisted of both Schwann cells and fibroblastic cells like neurofibromas, and only the former were found to contain S-100 protein. Thus, this study showed the heterogeneous nature of the malignant schwannomas and suggested that these tumors might arise from multipotential Schwann cells or different cellular components of peripheral nerve or primitive cells.

Adult↗

PubMedDate not supplied

Ultrastructural study of the myxoid area of malignant fibrous histiocytomas.

Seven malignant fibrous histiocytomas containing myxoid areas were studied to clarify the nature of the cells constituting the myxoid area with emphasis on multivacuolated cells known to be present in myxoid areas. Ultrastructurally, myxoid areas were, like conventional cellular areas, composed mainly of atypical tumor cells, small histiocytic cells, and occasional lymphoid cells. The tumor cells had large, indented nuclei and well-developed organelles. They showed, despite some variations in subcellular structures, strong resemblance to fibroblast and could be attributable to one cell type. The large vacuoles in multivacuolated tumor cells seemed to be formed by fusion of small vacuoles that appeared in the cytoplasm and later came to communicate with the extracellular space. The small histiocytic cells, cytologically bland and, occasionally, being in contact with lymphoid cells, were readily distinguishable from the tumor cells and were considered to be infiltrating reactive cells.

Adult↗

PubMedDate not supplied

Paraganglioma of the cauda equina: an ultrastructural and immunohistochemical study of two cases.

The ultrastructural and immunohistochemical features of 2 paragangliomas arising in the cauda equina are described. In both cases the tumor cells were arranged in small nests or cords and contained characteristic neurosecretory granules, lamellar stacks of rough endoplasmic reticulum (RER), and some well-developed Golgi apparatuses in their cytoplasm. The cells varied in electron density; the darker cells, occasionally resembling sustentacular cells, were probably dehydrated light cells because they contained a few neurosecretory granules. Sustentacular cells were difficult to identify by electron microscopy, but irregularly distributed S-100 protein and glial fibrillary acidic protein (GFAP) were found in these cells by immunostaining. Many tumor cells contained abundant neurofilaments. Curiously, a few cytokeratin-positive cells were found in 1 case. On microscopic examination, a small area of ganglioneuroma was found associated with the paraganglioma in 1 case. Ganglionic differentiation was concluded to be frequent in paragangliomas of the cauda equina region as in duodenal paragangliomas.

Adult↗

PubMedDate not supplied

Pulmonary blastoma: an ultrastructural and immunohistochemical study with special reference to nuclear filament aggregation.

A case is presented of pulmonary blastoma occurring in the right upper lobe of a 25-year-old man without distinct clinical features and laboratory abnormality. Light microscopic analysis revealed that the tumor was composed of branching glands and morulae embedded in a primitive but bland mesenchyme. Immunohistochemically the epithelial cells were immunoreactive for cytokeratins, S-100 protein, protein gene product 9.5, chromogranin A, calcitonin, and Ki-67 (MIB-1); the mesenchymal cells were immunoreactive for vimentin, actin, cytokeratins, and Ki-67; and all the tumor cells were negative for p53, estrogen receptor protein, and human chorionic gonadotropin beta. Characteristically, many epithelial cells contained optically clear nuclei which were immunoreactive for biotin (M743). Electron microscopic analysis revealed that the optically clearing change was due to replacement of the central area of the nuclei by a mass of parallel-arranged 7- to 10-nm filaments, and biotin-immunoreactive products were mainly localized in the nuclear matrix. Additionally, spherical bodies were identified in the cytoplasm of the nuclear filament-aggregated cells, suggestive of an intimate pathogenetic association of the two morphological abnormalities. The similarity of the aggregated nuclear filaments to those observed in gestational endometrium and ovarian endometrioid carcinoma implies that a similar mechanism plays a role in the pathogenesis of these abnormalities.

Adult↗

PubMedDate not supplied

Ultrastructural heterogeneity of acquired intradermal melanocytic nevus cells.

The present ultrastructural evaluation of 12 acquired intradermal melanocytic nevi revealed that in contrast to the nested epithelioid melanocytic nevus cells of the upper dermis, the spindle nevus cells of the deep dermis showed perineurial differentiation, exhibiting a spindly configuration characterized by a melanosome-free cytoplasm that showed extremely slender bipolar contour and contained abundant intermediate filaments, a decreased number of cytoplasmic organelles, and, significantly, a fair number of plasmalemmal pinocytotic vesicles. The nevic corpuscles were found to consist of laminated slender cytoplasm showing subcellular conformation similar to that of the spindle nevus cells. By immunohistochemistry, many spindle nevus cells and nevic corpuscles were immunoreactive for nerve growth factor receptor. All the nevus cells were immunoreactive for vimentin and S-100 protein, and negative for protein gene product 9.5, epithelial membrane antigen, Leu-7, and myelin basic protein. Characteristically, protein gene product 9.5 immunohistochemistry revealed numerous immunoreactive axons intermingled with the spindle nevus cells in the deep portion. All the PGP9.5-immunoreactive axons were observed by immunoelectron microscope to be unmyelinated and always ensheathed by a thin cytoplasmic process of Schwann cells but not nevus cells. These findings indicate that differentiation plasticity exists in the various nevus cells, with the epithelioid nevus cells and the spindle nevus cells displaying more ultrastructural and immunophenotypical characteristics of melanocyte and perineurial cells, respectively, suggesting that a pluripotential cell of neural crest origin accounts for the histogenesis of this lesion.

Humans↗

PubMedDate not supplied

Atypical glomus tumor in the mediastinum: a case report with immunohistochemical and ultrastructural studies.

A case is reported of atypical glomus tumor occurring in the posterior inferior mediastinum of a 26-year-old woman complaining of severe back pain. The tumor was composed of atypical small, round tumor cells with scattered mitotic figures. In addition to sheet-like, diffuse proliferation of the tumor cells, some areas of the tumor contained small "glomoid" cells arranged in organoid and hemangiopericytomalike patterns. Immunohistochemically, many tumor cells were positive for muscle-type actins and a few cells were focally positive for desmin. Ultrastructural studies revealed smooth muscle features of tumor cells, that is, pinocytotic vesicles, external laminas, dense plaques, and occasional thin filaments with dense bodies. The patient remained well for 5 years and 4 months after the operation without additional radiation and chemotherapy. The tumor was diagnosed as an atypical, or low-grade malignant, glomus tumor morphologically. It seems important to recognize the presence of this type of tumor in sites other than extremities and to differentiate it from other malignant small, round cell tumors.

Actin Cytoskeleton↗