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Biomedical subjects

K Morimoto

Publications and source records attributed to K Morimoto.

At least 613 records · Page 34Linked to original sources
PubMed1985

[Extremely low-birth-weight infant with post-hemorrhagic hydrocephalus: surgical procedure and recognition by sonography].

In two infants admitted to the neonatal intensive care unit with birth-weight of less than 1,000 g, serial cranial real-time sonograms were obtained to determine the subependymal germinal matrix hemorrhage and follow up the post-hemorrhagic hydrocephalus, compared with computerized tomographic scan. This paper reports the results of the placement of a subcutaneous ventricular reservoir in these extremely low-birth-weight infants to resolve progressive post-hemorrhagic hydrocephalus and protect their cortical mantle until their risks of ventriculo-peritoneal shunting procedure are acceptable. In these infants, the hydrocephalus and increased intracranial pressure were controlled and following shunting procedure after their medical and anesthetic problems resolved.

Cerebral Hemorrhage↗
PubMed1985

Transcatheter arterial chemo-embolization (TAC-E) for patients with locally advanced breast cancer.

Preoperative transcatheter arterial chemo-embolization (TAC-E) was used for 19 patients with locally advanced breast cancer, to eradicate the extensive loco-regional areas prior to surgery and hopefully to reduce the postoperative recurrence rate. The results were as follows: (1) Each primary tumor showed marked regression within 2 weeks after TAC-E. (2) Surgicopathology confirmed the excellent efficacy of TAC-E against both primary tumors and metastatic lymph node tumors. (3) Side effects due to this treatment were few, compared with other forms of cancer chemotherapy. (4) The prognosis of each patient was good. We conclude that preoperative TAC-E has a great potential for the treatment of locally advanced breast cancer.

Adult↗
PubMed1985

[Bilateral, symmetrical hemorrhagic infarction of the basal ganglia and thalamus following neonatal asphyxia].

With the advancement of perinatal intensive care, the occurrence of subependymal germinal matrix hemorrhage (= GMH) in low-birth-weight (premature) infants has became a major concern in perinatal medicine. The pathophysiology of the GMH has long been controversial. The introduction of computed tomographic (= CT) scanning to perinatal medicine has revealed various pathological events heretofore unknown in newborn infants having respiratory and circulatory distress. At our serving the entire Osaka Prefecture, infants suffering from birth asphyxia with severe perinatal brain damage were found to have CT findings distinguishable from those of GMH. We report three asphyxiated newborn infant who had hemorrhagic infarction in bilateral caudate nucleus, striatum and thalamus on the CT scan. Reports of similar findings are rare, and ours is the first serial observation of such CT scan image in newborn infants. The mechanism of development and pathology of this pathological condition have been variously argued as pathophysiology of GMH. The present study lacks postmortem examination, however, the findings in serial CT scans in three infants and review of the literatures related to the pathology of neonatal asphyxia indicate the following course. The thrombosis in the internal cerebral veins led to severe swelling of the brain, and hemorrhage occurred with the reduction in the swelling, eventually resulting in diffuse leukomalacia. Etat marbré (status marmoratus), mentioned earlier, is considered to represent a milder stage of this pathologic course.(ABSTRACT TRUNCATED AT 250 WORDS)

Asphyxia Neonatorum↗
PubMed1985

[Preoperative adjuvant chemotherapy of skeletal and soft tissue sarcomas].

Preoperative adjuvant chemotherapy for skeletal and soft tissue sarcomas requires: (1) correct identification of the effective postoperative adjuvant chemotherapy, (2) eradication of any of the micrometastatic foci that may have already occurred in many of the patients with these sarcomas, (3) easier and safer limb-salvage procedure, being clearly defined, with shrinkage of the primary lesion. For this purpose, a preoperative adjuvant chemotherapy regimen making practical use of intra-arterial CDDP (cis-dichlorodiammineplatinum II) infusion is desired in multi-drug combined chemotherapeutic treatment, including HDMTX (high-dose methotrexate), ADR (adriamycin) and CDDP. In this paper, the clinical application of preoperative adjuvant chemotherapy to skeletal and soft tissue sarcomas with combination of HDMTX and CDDP is presented in the light of the observations of tumor response to these anticancer agents, and the possibility of to establishing a new preoperative adjuvant protocol is discussed.

Adolescent↗
PubMed1985

[Nasopharyngeal paraganglioma extending to the middle cranial fossa].

A case report of a 15-year-old boy with a nasopharyngeal paraganglioma extended to middle cranial fossa is presented. We are reporting the fifteenth patient with a primary nasopharyngeal paraganglioma and reviewing the pertinent literature. The unusual initial presentation of oculomotor palsy and response to radiotherapy is described. The possible origin and radiosensitivity of this tumor discussed. Although the choice of therapy for this tumor remain controversial, the preferred treatment has been radiotherapy, in conjunction with surgical procedures for the mass of middle cranial fossa.

Adolescent↗
PubMed1985

Reduction of O6-alkylguanine-DNA alkyltransferase activity in HeLa cells treated with O6-alkylguanines.

Exposure of HeLa cells to 0.2 mM O6-methylguanine for 4 h or longer led to a 70-80% loss in the activity of the DNA-repair protein, O6-alkylguanine-DNA alkyltransferase. The decline in alkyltransferase activity brought about by O6-methylguanine was reversible on removing the base but at least 48 h were required for complete restoration. This loss of activity could also be brought about by other O6-alkylguanines including ethyl, n-propyl, and n-butyl, but the isopropyl and 2-hydroxyethyl derivatives were considerably less active. The rate of decline of alkyltransferase activity produced by O6-methylguanine was much more rapid than the rate of loss when protein synthesis was inhibited indicating that it was not brought about by blocking the synthesis of the protein. The loss of alkyltransferase activity was not prevented by the addition of inhibitors of nucleic acid or protein synthesis suggesting that it did not require protein synthesis or the incorporation of the O6-alkylguanine into nucleic acids. When cell free O6-alkylguanine-DNA alkyltransferase preparations were incubated in vitro with O6-methylguanine they became inactivated and when O6-[3H]methylguanine was used, [3H]guanine was produced. The inactivation was concentration dependent requiring 0.4 mM for a maximal rate and was quite slow requiring 3-4 hours for completion. These results suggest that the loss of O6-alkylguanine-DNA alkyltransferase activity is brought about by the free base acting as a very weak substrate for the protein. Exposure of mammalian cells to O6-methylguanine or O6-n-butylguanine provides a means by which the level of O6-alkylguanine-DNA-alkyltransferase can be regulated experimentally. This should enable the design of experiments to examine the role of O6-alkylguanine adducts in mutagenesis, carcinogenesis, and cell toxicity after administration of alkylating agents.

Female↗
PubMed1984

Enhanced rectal absorption of [Asu1,7]-eel calcitonin in rats using polyacrylic acid aqueous gel base.

The effects of polyacrylic acid aqueous gel on the absorption of rectally administered [Asu1,7]-eel calcitonin, a calcitonin analogue, were investigated in rats. The [Asu1,7]-eel calcitonin (1 U/kg) was given into the rectal loop in gel bases at various pH (5.5-8.5) and polyacrylic acid concentrations (0.01-1.0% w/v). The maximum hypocalcemic effect was obtained in approximately 30 min after administration of the analogue in a 0.1% w/v polyacrylic acid gel base at pH 5.5. The plasma calcium level decreased by approximately 18% from the initial level. Rectal administration in vehicles such as polyethylene glycol 1000, triglyceride fatty acid mixture base, or saline solution had little or no hypocalcemic effect at a dose of 5 U/kg. The results indicated that a polyacrylic acid aqueous gel base significantly improved the absorption of this analogue. Furthermore, rectal administration in a polyacrylic acid gel base (0.1% w/v; pH 5.5) required a dose 35 times greater than an intravenously administered dose to achieve an equivalent hypocalcemic effect.

Acrylic Resins↗
PubMed1984

Proliferative kinetics and chemical-induced sister chromatid exchanges in human lymphocyte cultures.

Although human lymphocyte cultures contain cells that have divided for different numbers of times after PHA stimulation, this heterogeneity of different cell divisions can be explained by a difference in the times when cells start their first DNA synthesis in responding to PHA. Cycling lymphocytes, whether they entered cycling earlier or later after stimulation, have about the same mean cell cycle times of 12-14 hr. Treatment with 3 X 10(-6) M MMC was found to induce an approximately 5-hr delay in the cell cycle. The induction of SCEs by chemical treatment depends on the stage in the cell cycle at treatment and on the persistence of the induced SCE-forming lesions. The most efficient time of treatment is the G1/S boundary in the first cell cycle of the 2 consecutive cycles before sampling. Among 3 alkylating agents tested here, EMS and 4NQO induce quite long-lived lesions that lead to SCE formation, whereas MMC-induced lesions seem to be completely removed within a cell cycle. Treatments with increasing concentrations of the chemical induce a larger increase in SCE frequency and longer delays in the cell cycle. However, with a fixed experimental regimen, treatments with relatively higher doses cause a deformity of the dose-response relationship. The data also show that longer BrdUrd treatment before fixation results in a sampling of cells that have higher SCE frequencies. Repeated pretreatments of human lymphocytes with a very low concentration of MNNG render them resistant to a following challenge with MNNG, or ENU, but not with MMC. The data at present indicate that there is a quite large variability among blood donors in this induction of resistance in lymphocytes.

4-Nitroquinoline-1-oxide↗
PubMed1984

Human health situation and chromosome alterations: sister chromatid exchange frequency in lymphocytes from passive smokers and patients with hereditary diseases.

Lymphocytes from passive smokers, and patients with FA, Alz, or FPC were studied for SCEs in cultures treated with MMC, 4NQO, or MNNG. Fanconi anemia lymphocytes were also studied for cell cycle Tab. 3. Mean SCE frequencies in FPC or normal cells. (Table; see text) kinetics, and CAs after completion of 1, 2, or 3 or more divisions in MMC-treated cultures. The results can be summarized as follows: (1) lymphocytes from passive smokers showed a slightly higher induction of SCEs than nonsmokers when exposed to MMC. (2) FA cells had about 1.4 times higher frequencies of SCEs than normal cells in both MMC-treated and untreated cultures while they showed several times higher frequencies of CAs in both cultures. Analyses of cell cycle kinetics by the sister chromatid differential staining method revealed that MMC treatments of FA and normal cells led to a clearly dose-related delay in cell turnover times, the duration of delay being much longer in FA than in normal cells. (3) Alz cells showed about 1.5 times higher induction of SCEs in MMC-treated cultures whereas they had only 10% as much SCEs as controls when exposed to 4NQO. Familial polyposis coli cells showed no significant difference in the induction of SCEs in untreated cultures and cultures treated with MMC, 4NQO, and MNNG.

4-Nitroquinoline-1-oxide↗
PubMed1984

Bleomycin-induced chromosomal aberrations and sister chromatid exchanges in Down lymphocyte cultures.

Peripheral blood lymphocytes from three patients with Down syndrome (DS; trisomy 21; aged 5-6 years) and three age-matched control children were studied for the induction of chromosomal aberrations and sister chromatid exchanges (SCEs). Cells in G0 were exposed to bleomycin (20-100 micrograms/ml) for 3 h, and then cultured in medium containing 5-bromodeoxyuridine and phytohemagglutinin for 66 h. By the sister chromatid differential staining method, chromosome analyses were performed on metaphase cells that had divided one, two, or three or more times after treatment. The results indicate that DS cells exposed to bleomycin are hypersensitive to the production of dicentric and ring chromosomes compared to normal cells. Bleomycin also led to a dose-related increase in the frequency of SCEs, but no difference was found between the SCE frequencies in DS or normal lymphocytes exposed to bleomycin.

Bleomycin↗
PubMed1984

Amino acid transport in human tonsillar lymphocytes with regard to patient's age and tonsillar diseases.

Amino acid transport in human tonsillar lymphocytes was investigated in 32 patients of various ages and with different tonsillar diseases. Tonsillar lymphocytes appeared to possess at least four different transport systems for neutral amino acids including the activated Na+-dependent A system transport. The transport activity of neutral amino acid was significantly higher in child cases than in adult cases. In adult cases with focal tonsillitis, tonsillar lymphocytes were taken from patients with rheumatoid arthritis (RA) and skin diseases as secondary lesions who showed good improvement of the skin lesions after tonsillectomy. These lymphocytes were revealed to have more activated Na+-dependent transport than those from patients with skin diseases who showed poor improvement of the skin lesions after the tonsillectomy, and those from patients with recurrent tonsillitis. The characteristics of amino acid transport in human tonsillar lymphocytes and changes influenced by age and tonsillar diseases are discussed.

Adult↗
PubMed1984

Immunohistochemical localization of creatine kinase BB-isoenzyme and tubulin in gerbil brain.

Cellular distribution of creatine kinase BB-isoenzyme and tubulin was investigated immunohistochemically with tissue sections from various areas of the gerbil brain. Both the reaction for creatine kinase BB-isoenzyme and tubulin visualized nerve cell bodies, dendrites and axons. While the reaction for tubulin was similar between nerve cell bodies and their dendrites, the reaction for creatine kinase BB-isoenzyme tended to be more intense in dendrites. While the reaction for tubulin could be seen in nerve cell bodies of different sizes, the reaction for creatine kinase BB-isoenzyme was more intense in larger neurons. Both the reaction for creatine kinase BB-isoenzyme and tubulin visualized astrocytic cytoplasm but only in the corpus callosum and in the white matter of limited areas. Visualization of dendrites to their peripheries with the reaction for creatine kinase BB-isoenzyme may indicate participation of this isoenzyme in maintainance of high energy-phosphates locally within dendrites. A combination of the immunohistochemical procedure for creatine kinase BB-isoenzyme and tubulin may be very useful for demonstration of various pathophysiological states of the central nervous system which affect dendrites.

Animals↗
PubMed1984

Antiepileptic effects of thyrotropin-releasing hormone and its new derivative, DN-1417, examined in feline amygdaloid kindling preparation.

The comparative antiepileptic effects of the thyrotropin-releasing hormone and its new derivative, gamma-butyrolactone-gamma-carbonyl-L-histidyl-L-prolinamide citrate (DN-1417), were examined in feline amygdaloid kindling preparations. When tested in kindled animals, both agents showed a transient and non-dose-dependent anticonvulsant effect, in addition to raising the generalized convulsive seizure-triggering threshold for a prolonged period of time. Furthermore, DN-1417 exerted a significant effect on postictal events: shortening the electrographic silence, leaving the duration of slow activity intact, while prolonging the period of seizure refractoriness. When tested in kindling animals, DN-1417 showed a significant but non-dose-dependent prophylactic effect on both primary and secondary amygdaloid sites.

Amygdala↗