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Biomedical subjects

M Iijima

Publications and source records attributed to M Iijima.

At least 127 records · Page 7Linked to original sources
PubMed1995

Two-dimensional electrophoretic analysis of down-regulated proteins in human fibroblasts immortalized by treatment with either 4-nitroquinoline 1-oxide or 60Co gamma rays.

Cellular proteins were examined by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) in order to determine the mechanisms of cellular aging and immortalization of human fibroblasts. A total of 10 cell lines were studied, four of which were immortalized. OUMS-24F and SUSM-1 cells were immortalized by repeated treatment with 4-nitroquinoline 1-oxide (4NQO), KMST-6 cells were immortalized by intermittent exposure to 60Co-gamma rays, and IMR-90/SV40 cells were immortalized with simian virus 40 (SV40). None of these immortalized cells were tumorigenic. Four normal human fibroblast cell lines, OUMS-24, AD 387, KMS-6 and IMR-90, and two human cervical cancer cell lines, HeLa and A-431, were also studied. Applying 2-D PAGE, the down-regulation of the identical proteins was observed in the four immortalized cell lines and in the two human cancer cell lines. Their molecular masses were about 80 kDa and the isoelectric points ranged between 5.5 and 6.3. We could not find any information on our proteins from the recent protein data bases. Further characterization of the proteins indicated that they might be phosphorylated cytoskeletal proteins.

4-Nitroquinoline-1-oxide↗
PubMed1995

Adult-onset xanthogranuloma appearing symmetrically on the ear lobes.

Clinical backgrounds of patients with adult-onset xanthogranuloma are somewhat different from those of patients with juvenile xanthogranuloma, but the histologic findings of both forms of the disease are identical. The lesions of the adult form are usually asymmetric. We describe a patient with adult-onset xanthogranuloma that appeared symmetrically on the ear lobes. This case suggests a possible role for mechanical stimuli (e.g., earrings) in the pathogenesis of adult-onset xanthogranuloma.

Diagnosis, Differential↗
PubMed1995

Expression of aqualysin I (a thermophilic protease) in soluble form in Escherichia coli under a bacteriophage T7 promoter.

The thermophilic protease aqualysin I (AQI) gene (aquI), derived from Thermus aquaticus YT-1, was inserted under the control of the bacteriophage T7 promoter in an expression plasmid. The plasmid was introduced into two strains of E. coli JM109 (DE3), one carrying and one lacking an F' episome, which carries the lacIq gene. Upon cultivation the strain carrying an F' episome produced AQI as an insoluble fusion protein (74kDa) with the T7 gene 10 protein. This insoluble protein could not be processed into mature AQI by heat treatment and thus it had no proteolytic activity. On the other hand, when the strain lacking an F' episome was used as a host cell for aquI expression, non-induced, or leaky, expression occurred, and AQI was produced in a soluble form. This soluble protein could be processed into active AQI by heat treatment. Moreover, when a low concentration of IPTG (0.0125 mM) was added, the amount of active AQI was 2.7 times greater than that produced in a batch culture without induction.

Bacteriophage T7↗
PubMed1995

Karyotypic analysis in the process of immortalization of human cells treated with 4-nitroquinoline 1-oxide.

The establishment of a model system of neoplastic transformation of normal human cells has been attempted with a chemical carcinogen, 4-nitroquinoline 1-oxide (4NQO). In the course of these experiments, it was noticed that immortalization of human cells is a multi-step process involving several mutational genetic events. Thus, chromosomal changes which occurred during the process of immortalization of human fibroblasts were examined. To accomplish immortalization, fibroblasts obtained from an embryo were repeatedly treated with 10(-6) M 4NQO from primary culture to passage 51 (59 treatments in total). Before immortalization, some chromosomes (especially, chromosomes 2, 6, 8, 10, 11, 12, 15, 19, and 20), were lost at a relatively high frequency. After immortalization, the chromosomes distributed so broadly in the triploid to hypotetraploid region without a distinct modal number or without marker chromosomes that it was difficult to identify the specific chromosomes related to the immortalization of human cells. No specific structural chromosomal changes were detected. Although the significance of such chromosome changes in relation to immortalization is not clear, the loss of some specific chromosomes suggests that genes which are involved in cellular aging and which suppress immortalization may have been lost in the immortalization process.

4-Nitroquinoline-1-oxide↗
PubMed1995

A new method for in vitro calcification using acrylamide gel and bovine serum.

To investigate the mechanism of biological calcification in vitro, a model system consisting of an acrylamide gel block (1 x 3 x 3 mm) and fetal bovine serum was developed. Mineral deposition was induced in gel blocks which were immersed in 300 microliters of fetal bovine serum at 37 degrees C for 7 days in a CO2 incubator. X-ray diffraction indicated that the mineral was hydroxyapatite with low crystallinity. Effects of the concentration of acrylamide gel, the partial pressure of CO2 and matrix proteins within the gel on the mineral formation were investigated. In the gel concentration range of 10-60%, the largest amount of crystal grew in 40% acrylamide gel, where the serum protein did not penetrate. With an increase in the partial pressure of CO2 the Ca content in the gel block increased, reached the highest level at about 3.5% CO2 and then began to decrease. In 40% gel and at 5% CO2, the mineral formation was enhanced by phosvitin, phosphophoryn, demineralized dentin powder and alkaline phosphatase. Mineral deposition occurred around the collagen fibers immobilized in 40% acrylamide gel. These results indicate that 1) a putatively serum-derived inhibitor of calcification with high-molecular weight was prevented from penetrating into the 40% acrylamide gels, 2) immobilized polyanionic proteins and alkaline phosphatase were able to increase mineral deposition and 3) the partial pressure of CO2 greatly influenced the mineral deposition. It was concluded that this gel system is useful to investigate the mechanism of biological calcification in vitro.

Acrylamides↗
PubMed1995

Oriented growth of octacalcium phosphate on and inside the collagenous matrix in vitro.

To investigate the factors which regulate the growth of apatite in a collagenous matrix, a calcification experiment was carried out in a model system, where Ca2+ and PO43- ions diffused into a slice of Achilles tendon from mutually opposite grew on the Ca-side of the collagenous matrix, while small plate-like OCP crystals (< 1 micron) grew inside the matrix. The major part of crystals grew with the c-axis parallel to the collagen fibers. Others grew with the c-axis parallel to the collagen bands or perpendicular to the fibrils. Crystals grew with orientation on collagen fibrils from the beginning. It was concluded that collagen fibrils and property of the collagenous matrix played a regulatory role in the deposition and growth of OCP in the collagenous matrix.

Achilles Tendon↗
PubMed1995

[Evaluation of the plasma endothelin levels in facial nerve paralysis].

The etiology of so-called Bell's palsy is still unknown. Based on the hypothesis that endothelin, with its potent vasoconstricting action, is in some way involved in the etiological mechanism of facial nerve paralysis, we measured the blood endothelin levels of 62 patients with Bell's palsy in the acute stage (within one week following onset). The measurements were extended to include 10 patients with Ramsay Hunt syndrome and 14 patients with zoster sine herpete. To determine endothelin content, blood samples were drawn into blood collecting tubes, containing EDTA-2Na+aprotinin at any time desired during the day. The samples were immediately chilled and centrifuged to separate the plasma portion, and 2ml of this plasma sample was preserved by freezing. ET-1 was extracted using silica-ODS and analyzed by RIA using anti-ET 1 antibody. An age-matched comparison between the Bell's palsy patients and 36 normal individuals using the Mann-Whitney U test showed a significant difference (p < 0.01). The patients with Ramsay Hunt syndrome and zoster sine herpete also tended to have elevated endothelin levels. This finding suggests that disorders of the microcirculatory system in which endothelin is in some way involved may play a role in the pathogenesis of facial nerve paralysis.

Adolescent↗
PubMed1995

Action of cytogenin on lymphoid cells and their cytokine production.

Action of cytogenin on macrophages and T cells was investigated. Phagocytosis of yeast and production of PMA-elicited superoxide anion by macrophages taken from mice given cytogenin po were augmented. Cytogenin enhanced productions of IL-1 alpha by macrophages and IFN gamma and GM-CSF by spleen cells although it did not enhanced production of TNF alpha by macrophages and IL-6 by macrophages and spleen cells. Macrophages stimulated with cytogenin caused to stimulate proliferation of purified T cells in Intercell cultures in which each cell population was cultured without contact. Results suggest that cytogenin primarily activates macrophages to produce monokines such as IL-1 alpha and it causes to stimulate proliferation and differentiation of T cells resulting in production of lymphokines such as IFN gamma and GM-CSF.

Animals↗
PubMed1995

[Radiotherapy for intracranial meningioma: special reference to malignant and high risk benign meningioma].

Results of radiotherapy in 21 patients who had been treated for intracranial meningioma from April 1975 to March 1993 at Tokyo Metropolitan Komagome Hospital are presented. All patients were treated with 4 MV X-rays using conventional fractionation. The median tumor dose was 54.4 Gy (range 30 Gy to 70 Gy). Radiotherapy was delivered by conformation technique in 11, parallel opposed field in four and three ports technique in two. Of 21 meningiomas, 13 were histologically malignant and 8 were benign. The median follow-up period was 63 months. Overall survival rate at 5 years was 71% for benign and 63% for malignant meningiomas; the 5-year progression-free survival rates were 25% and 30%, respectively. Eight of 21 patients received 60 Gy or more, and the remaining 13 received less than 60 Gy. The 5-year overall survival rates for these two groups were 43% and 83% (p < 0.05), respectively. Ten of 21 patients were treated with post-operative radiotherapy as initial treatment and eleven of 21 patients were treated with salvage therapy with or without surgical excision for recurrent lesions. The 5-year survival rates and progression-free survival rates of these two groups showed no significant differences. From analysis of the clinical course of the salvage therapy group, radiotherapy may prolong survival time and delay further tumor recurrence. According to the present study, radiotherapy (doses of 55 Gy to 60 Gy) after primary resection and at the time of recurrence are equally effective for prolongation of survival and delay of further tumor recurrence.

Adolescent↗
PubMed1994

[Radiotherapy for advanced carcinoma of the gallbladder: special reference to IORT and hyperthermo-chemo-radiotherapy].

The results of radiotherapy in 37 patients who were treated for carcinoma of the gallbladder from April 1975 to April 1992 are presented. To analyze the treatment results, patients were divided into four groups depending on treatment modality: intraoperative radiotherapy (IORT) with surgical resection in 9 (resection group), IORT with palliative surgery in 5 (palliative surgery group), hyperthermo-chemo-radiotherapy for inoperable cases in 11 (HCR group), external irradiation for inoperable cases in 12 (ExRT alone group). Most of the patients in the resection group received ExRT. The HCR group showed better local response than the groups treated with palliative surgery and ExRT alone. The mean length of survival in the resection, palliative surgery, HCR and ExRT alone groups was 315 days, 144 days, 246 days and 74 days, respectively. Although no statistically significant difference in survival was observed between the resection and HCR groups, the relapse-free interval of the resection group was significantly longer than that of the other groups. The application of IORT for surgically resectable tumors contributed to improved prognosis and better quality of life. Although IORT for patients with unresectable tumors had little effect on survival, it was considered to play a palliative role in improving the quality of life. The HCR group had a significantly longer survival time and relapse-free interval than the palliative surgery and ExRT alone groups. In conclusion, the application of HCR for inoperable carcinoma of the gallbladder contributed to the improvement of prognosis and quality of life.

Adult↗
PubMed1994

Fermentation conditions for efficient production of thermophilic protease in Escherichia coli harboring a plasmid.

Escherichia coli TG1, transformed with an expression plasmid pAQN carrying the aqualysin I (AQI) gene derived from Thermus aquaticus YT-1 under the control of the tac promoter, was cultivated under various conditions in order to find fermentation conditions for the efficient production of the thermophilic protease, AQI. The amount of AQI produced was closely related to the growth phase at the time of isopropyl-beta-D-thiogalactopyranoside (IPTG) induction, and the highest production was obtained when it was added during the exponential growth phase. The addition of yeast extract had a greater effect on AQI production than did Polypeptone or casamino acids, and AQI productivity increased from 1.1 x 10(3) kU/g to 2.7 x 10(3) kU/g cells when 2 g/l yeast extract was supplied. Furthermore, the specific growth rate improved from 0.35 h-1 to 0.89 h-1 when 5 g/l yeast extract was supplied. The culture temperature also affected AQI gene expression. When the temperature was shifted from 37 degrees C to 34 degrees C at the time of IPTG induction, 19 kU/ml enzymatically active AQI was obtained, corresponding to a 28% increase over the amount produced in a batch culture without a shift. This is about a 44-fold higher yield than was obtained from the original strain, T. aquaticus YT-1.

Biotechnology↗
PubMed1994

Bile flow in a mutant Sprague-Dawley rat with defective biliary excretion of glutathione.

The Eisai hyperbilirubinemic rat is a mutant strain of Sprague-Dawley origin with hereditary defects in the biliary excretion of bilirubin glucuronide, glutathione, and several other organic anions. The correlation between bile flow and bile acid excretion rates during taurocholate infusion revealed that bile acid-independent flow was smaller in the mutant than in intact Sprague-Dawley rats (19.3 vs 56.0 microliters/kg per min), while bile acid-dependent flow was similar. The correlation between bile flow and glutathione excretion rates in Sprague-Dawley rats with modified hepatic glutathione levels revealed that a certain portion of bile flow was proportional to the biliary excretion of glutathione, with a coefficient of 551 bile per 1 mol glutathione. One-third of bile acid-independent bile flow in intact Sprague-Dawley rats was accounted for by glutathione osmosis, which feature was absent in the mutant rats.

Animals↗
PubMed1994

An autopsy case of PSP with astrocytic inclusions.

Argyrophilic glial cytoplasmic inclusions were observed in astrocytes (Astrocytic Inclusions) in a case of progressive supranuclear palsy (PSP). The inclusions were predominantly distributed in the lenticular nucleus and midbrain, but not in the cerebral cortex, white matter nor in the thalamus. When examined by double staining with Gallyas silver and GFAP, they resembled the neurofibrillary tangles (NFT) and were tau positive. The distribution of these inclusions was not related to that of NFT. These inclusions indicate that astrocytes were involved in the same pathological changes as NFT. Argyrophilic inclusions were also observed in oligodendroglias on Gallyas silver staining. They appeared coiled and located mainly in the cerebral and cerebellar white matter.

Astrocytes↗
PubMed1994

An autopsy case of Alzheimer disease with myoclonus and periodic spikes on EEG.

This is a case of Alzheimer disease with myoclonus and periodic spikes on EEG. A 56-year-old man developed progressive dementia and, 3 years later, generalized convulsions. Eight years later, he showed myoclonus and periodic spikes on EEG. Cranial CT showed cortical atrophy and ventricular dilatation. He became apallic and died of pneumonia at the age of 65.9 years after the onset of the disease. The brain weighed 1,050 g. Neuropathologically, diffuse neuronal loss, abundant neurofibrillary tangles and senile plaques, particularly diffuse plaques, were found extensively in the cerebral cortex. The white matter was preserved. In the Ammon's horn, abundant neurofibrillary tangles and senile plaques were observed. Grumose degeneration of the cerebellar dentate nucleus, Kuru plaques or prions were not found. Numerous diffuse plaques of the cerebral cortex have rarely been reported in autopsy cases of Alzheimer disease with myoclonus and periodic spikes on EEG.

Alzheimer Disease↗
PubMed1994

[Aging and immortalization of human cells].

In vitro models of malignant transformation of human cells may provide considerable insight into the mechanisms of multistep carcinogenesis. It is well established that normal human cells must be immortalized before they are malignantly transformed, but normal human cells are extremely refractory to immortalization, making malignant transformation very difficult. Thus immortalization is a rate-limiting step in the malignant transformation of human cells. In order to immortalize normal human cells with a chemical carcinogen, 4-nitroquinoline 1-oxide, or with 60Co gamma rays, the cells had to be repeatedly treated with these agents. This indicates that the immortalization process involves multiple mutational events and is itself a multi-step process. Then we found that there were mutations in p53 in all our immortalized cell lines. This encouraged us to attempt to immortalize human cells with the mutant p53. We introduced the mutant p53 (codon 273Arg-His) into normal human fibroblasts to learn whether the cells could be immortalized. The p53 extended the life-span of the cells but could not immortalize them. However, when we treated the p53-introduced cells with 4NQO, the cells were immortalized. The 4NQO treatment alone did not make the cells immortal. These results indicate that the p53 gene play a role in immortalization of human cells rather than in their malignant transformation.

4-Nitroquinoline-1-oxide↗
PubMed1994

[A case of occipital lobe epilepsy following cerebral infarction].

We report a rare case of occipital lobe epilepsy following cerebral infarction in bilateral occipital lobes. The patient is a seventeen-year-old female, who had cerebral infarction in bilateral occipital regions a few days after an open-heart surgery at 15 years of age. Thereafter she sometimes complained of visual field defects and ictal amaurosis. Seventeen months later, she developed a tonic seizure with ictal amaurosis, visual field defects and head deviation. On admission, results of the neurological examinations were all normal with the exception of peripheral visual field defects. Scalp electroencephalographic (EEG) findings showed paroxysmal discharges that were more prominent in the frontal to parietal leads than in the occipital leads. Sometimes the laterality of paroxysmal discharges changed. Her visual defects were diagnosed as psychogenic activity by the ophthalmological visual fields test. Simultaneous recordings of pattern reversal visual evoked potential (VEP) and electroretinograms (ERG) showed normal in 15 minute checks, but prolongation of bilateral P100 latency in 30 minute checks. These findings suggested that peripheral visual fields were disturbed. In this case, EEG findings and the initial symptoms of amaurosis and visual fields defect suggested occipital epilepsy following cerebral infarction in bilateral occipital lobes. We wish to emphasize that simultaneous VEP and ERG recording is a useful diagnostic tool for estimating visual functions.

Adolescent↗
PubMed1994

[A case of neuro-Behçet's disease with numerous hypertrophied and proliferated dendrites in the inferior olivary nucleus].

A 32-year-old man suffering from iritis, erythema, and recurrent oral aphthae showed signs of involvement of the central nervous system for 8 years before his death. Behçet disease was diagnosed. He showed neurologic symptoms, such as facial nerve palsy, gait disturbance, and pathological reflexes, and psychiatric symptoms, such as euphoria, disinhibition, and irritability. Characteristic neuropathologic findings were hypertrophy of the bilateral olivary nuclei with marked hypertrophy and proliferation of dendrites, which have been extremely rare in the reported autopsy cases of neuro-Behçet disease. Most changes were observed in the brainstem. Many microspongionecrotic foci were fused to from glial scars with marked lymphocytic perivascular infiltration. In addition, lesions were found throughout the spinal cord; degenerative changes were found in the lateral corticospinal tract, posterior colum (especially the fasciculus gracilis), and anterior and posterior spinocerebellar tracts. We believe, on the basis of the following neuropathologic findings, that the cause of the olivary pseudohypertrophy with dendritic hypertrophy and proliferation was a denervational process: (1) bilateral red nuclei were intact and (2) bilateral tegmental tracts had degenerated from the lower portion of the pons to the periphery of olivaly nuclei.

Behcet Syndrome↗