Biomedical subjects

H Ohji

Publications and source records attributed to H Ohji.

8 recordsLinked to original sources

PubMed2001

Changes in cellular immunity during chemotherapy for testicular cancer.

BACKGROUND: The changes in vivo in immunocyte functions during chemotherapy that is administered in combination with granulocyte colony-stimulating factor (G-CSF) in humans have not been fully investigated. This study was designed to examine neutrophil functions and the activities of natural killer (NK) cells, during the administration of chemotherapy and G-CSF for the treatment of testicular cancer. METHODS: Seven patients with germ cell tumors at stage IIA, IIB or IIIB, who were treated with bleomycin, etoposide and cisplatin (BEP), were enrolled in the study. Numbers and activities of neutrophils and NK cells were measured at various times during and after the first course of chemotherapy. Neutrophil phagocytosis was quantitated by flow cytometry with fluorescent latex beads. Bactericidal activity was measured in terms of colony-forming units. The activity of NK cells was measured by monitoring the release of 51Cr. RESULTS: After BEP chemotherapy, CD16+ and CD56+ cell counts, and neutrophil granulocyte counts decreased while there were no significant changes in the number of lymphocytes. Phagocytosis by neutrophils was enhanced after administration of G-CSF. The activity of NK cells was severely impaired after chemotherapy and did not change after administration of G-CSF. CONCLUSIONS: After BEP chemotherapy for testicular cancer with G-CSF, neutrophil function was not at all inferior to those before treatment. Natural killer cell activity was suppressed by the BEP chemotherapy and did not change after administration of G-CSF.

Adult↗

PubMed2001

Tumour angiogenesis and Ki-67 expression in phaeochromocytoma.

OBJECTIVE: To determine the expression of CD34 (to evaluate vascularity) and Ki-67 (as a proliferative index) in a variety of phaeochromocytomas and thus assess the utility of these markers as possible predictors of malignancy. PATIENTS AND METHODS: Deparaffinized tissue sections from 21 patients with benign and four with malignant phaeochromocytoma were assessed immunohistochemically to evaluate microvascular counts (using CD34 antigen) and the proliferative index (Ki-67 antigen, monoclonal antibody MIB-1). RESULTS: There was no statistical association between high microvascular counts and malignancy, but there was between the MIB-1 score and malignancy (P < 0.001). CONCLUSIONS: A high MIB-1 score in phaeochromocytoma suggests malignant behaviour in the component cells. The MIB-1 score may be a useful indicator for diagnosing malignant phaeochromocytoma.

Adrenal Gland Neoplasms↗

PubMed2000

Indication of cystoscopy in patients with asymptomatic microscopic haematuria.

To establish the appropriate indication of cystoscopy in patients with asymptomatic microscopic haematuria, we reviewed 263 cases with positive reaction for urinary dipstick test on annual health screening examination. On initial examination, 18 highly significant lesions, 52 moderately significant lesions and 38 insignificant lesions were detected. No underlying lesion could be found in 96 patients and no microscopic haematuria in 59 patients. However, bladder cancers were detected in only 8 (3.0%) cases. All patients with bladder cancer were older than 40 years. These facts suggest that cystoscopy is not necessary for patients with a single microscopic haematuria and those younger than 40 years.

Adolescent↗

PubMed1999

Relationship between clear cell/compact cell ratio and computed tomographic attenuation number in adrenocortical adenoma.

Clear cell/compact cell ratio in histologic sections from 21 resected adrenocortical adenomas was assessed. Seven patients had Cushing's syndrome another 7 had primary aldosteronism caused by adrenal adenomas and 7 had non-hyperfunctioning adenomas. The results were correlated with the corresponding unenhanced CT attenuation numbers. There was a negative correlation between clear cell/compact cell ratios and unenhanced CT attenuation numbers. However, CT attenuation numbers did not show significant differences between cortisol-producing, aldosterone-producing and nonfunctioning adenomas. These facts suggest that clear cell/compact cell ratio in adrenocortical adenomas accounts for their attenuation number on unenhanced CT scans. However, it is difficult with the use of unenhanced CT attenuation numbers to differentiate cortisol-producing adenomas from aldosterone-producing and nonhyperfunctioning adenomas.

Adrenal Cortex Neoplasms↗

PubMed1998

Dimethylarsinic acid, a main metabolite of inorganic arsenics, has tumorigenicity and progression effects in the pulmonary tumors of A/J mice.

The pulmonary tumorigenicity of dimethylarsinic acid (DMAA), a main metabolite of inorganic arsenics, was examined in A/J mice fed with drinking water containing DMAA for 25 and 50 weeks. Mice fed with 400 ppm DMAA for 50 weeks produced more pulmonary tumors than untreated mice (mean number per animal 1.36 versus 0.50; P < 0.05). Histological examination revealed that the number of mice which bore adenocarcinomas or papillary adenomas correlated with the concentration of DMAA given (untreated versus 400 ppm; P = 0.002), suggesting that DMAA could promote tumorigenic processes. These results are consistent with the epidemiological studies on the pulmonary carcinogenesis of arsenics and suggest that DMAA alone can act as a carcinogen in mice.

Animals↗

PubMed1997

Pulmonary endocrine cell hyperplasia and papilloma in rats induced by intratracheal injections of extract from particulate air pollutants.

We investigated the effect of intratracheal injections of an extract of suspended particulate matter (SPM) obtained from the urban ambient air of Tokyo, upon the development of proliferative lesions of pulmonary endocrine cells (PECs) in the rat. We also examined the modification effects of nitrogen dioxide, sulfur dioxide, or both of them on the PEC lesions. Male F344 rats were divided into six experimental groups of 5 animals each. Twenty animals were treated with intratracheal instillations of SPM admixed with carbon once a week for 4 weeks with or without additional gaseous exposure (6 ppm nitrogen dioxide or 4 ppm sulfur dioxide) 16 hrs a day for 11 months. Five animals were given intratracheal injections of carbon suspended in saline and the other five were untreated. The subcardiac lobes of the right lung were fixed with 4% paraformaldehyde, and embedded in paraffin. PEC hyperplasias and papillomas were counted in 200 serial sections, 4 microns thick. The average incidences of PEC hyperplasia in the untreated animals and in those treated with carbon were 194 and 200/cm3, respectively. The average incidences of PEC hyperplasia in the animals exposed to SPM tar only, SPM tar plus nitrogen dioxide and sulfur dioxide, SPM tar with nitrogen dioxide and SPM tar with sulfur dioxide were 376, 378, 372 and 349/cm3, respectively. These were significantly higher than the levels of the control animals, and additional gaseous stimuli had no effect on the incidence of PEC hyperplasia. Besides PEC hyperplasia, a few PEC papillomas were found in the animals treated with SPM tar, regardless of gaseous exposure, but in the control animals no papilloma was evident. Thus, compounds in airborne particulates are considered to be responsible for the development of PEC hyperplasias and papillomas.

APUD Cells↗

PubMed1996

Telomerase activity in normal human epithelial cells.

Telomerase activity is found in most cancer tissues and many immortalized cell lines as well as in germ line cells but it is generally undetected in normal human somatic tissues. There is weak telomerase activity in some cell types of hematopoietic lineage in which a stem cell-like subpopulation may exist. Likewise, physiologically regenerating somatic tissues and organs such as skin, small intestine, and most other epithelia of the human body are supposed to contain similar cell lineages to maintain their renewal throughout the life span of individuals. It is therefore of interest whether telomerase activity is present in physiologically regenerating epithelial cells. Telomerase activity was detected, though very weakly, in cultured normal epidermal keratinocytes and at higher levels in a subpopulation that adhere rapidly on collagen IV-coated culture dishes. No telomerase activity was detected in a subpopulation that was less adherent on the coated dishes. The rapidly adherent subpopulation of keratinocytes was enriched in small proliferating cells with macrocolony forming potential. It was also passaged through more generations in culture, and expressed integrin beta 1 at higher levels than the less adherent subpopulation. Telomerase activity was similarly found in ectocervical keratinocytes as well as in simple endocervical epithelial cells. These findings provide the evidence of a telomerase-positive population among physiologically regenerating normal human epithelial cells. The identity of the telomerase-positive cells remains to be defined.

Base Sequence↗

PubMed1996

Exposure to dimethylarsinic acid, a main metabolite of inorganic arsenics, strongly promotes tumorigenesis initiated by 4-nitroquinoline 1-oxide in the lungs of mice.

The effect of dimethylarsenics on the pulmonary tumorigenesis initiated by 4-nitroquinoline 1-oxide (4NQO) in mice was examined. The exposure of mice to dimethylarsinic acid (DMAA), a major metabolite of inorganic arsenics in mammals, resulted in not only promotion but also progression of the tumorigenic process in the lungs of mice administered 4NQO. Furthermore, dimethylarsenics influenced the differentiation process in lung tumorigenesis by 4NQO. These results may pave the way for the elucidation of lung carcinogenesis caused by arsenics.

4-Nitroquinoline-1-oxide↗