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Biomedical subjects

K Morimoto

Publications and source records attributed to K Morimoto.

At least 631 records · Page 35Linked to original sources
PubMed1984

Rapid estimation of the duration of gamma-ray-induced proliferation delay in human lymphocytes by the harlequin staining technique.

The duration of gamma-ray-induced proliferation delay in human lymphocyte cultures was measured by a rapid and simple method using fluorescence-plus-Giemsa (harlequin) staining to distinguish between cells that had divided different numbers of times in culture. By this rapid method, irradiation of unstimulated (G0) or stimulated (G1) lymphocytes was shown to result in a proliferation delay of 1.2 h/Gy (1.2 h/100 rad) or 1.4 h/Gy (1.4 h/100 rad), respectively, in 64 h cultures: The duration of delays had a linear relationship with doses from 2 to 8 Gy (200 to 800 rad).

Adult↗
PubMed1984

CT of hepatoma. Dilatation of the intrahepatic bile ducts and intraductal tumour growth.

Computed tomography revealed dilatation of the intrahepatic bile ducts in 25 out of 135 cases of hepatocellular carcinoma. In 6 (4.5%) of these 25 cases the dilatation was generalised, while in the remaining 19 cases (14%) dilatation was localised. In each group 3 cases of intraductal tumour growth was confirmed either at operation or autopsy. With metastatic liver tumour, generalised dilatation was observed in 6 cases (7%) and localised dilatation in 3 (3.5%) out of 85 cases. Localised dilatation was found with higher incidence in hepatocellular carcinoma than in metastatic tumour. This may indicate that the incidence of intraductal infiltration is high in cases of hepatocellular carcinoma. When a relatively small tumour is associated with dilatation of bile ducts, it is more probable that the tumour is a hepatocellular carcinoma than a hepatic metastasis.

Adult↗
PubMed1984

Proliferative kinetics and chromosome damage in trisomy 21 lymphocyte cultures exposed to gamma-rays and bleomycin.

Lymphocytes from patients with Down's syndrome (trisomy 21) have been investigated for cell cycle kinetics, cell proliferation delays, and chromosomal aberrations after exposure to gamma-rays or bleomycin. Analysis by sister chromatid differential staining revealed that trisomy 21 lymphocytes started cell cycling about 5 hr earlier than did normal diploid lymphocytes after phytohemagglutinin stimulation as a whole, but that cycling trisomic and normal cells had the same mean cell cycle times. When exposed to gamma-rays or bleomycin in G0, trisomy 21 lymphocytes showed a 30% or, on average, 50% longer duration of cell turnover times, respectively, than normal cells; only bleomycin-treated trisomic cells had a biphasic dose-response. Frequencies of dicentrics and rings in first-division cells after gamma-ray or bleomycin exposure were twice as high in trisomic cells as in normal cells. The frequency of aberrations decreased by 50% (gamma-ray-exposed) or 65 to 85% (bleomycin-treated) through successive divisions; trisomic cells showed a more marked decline in aberration yields compared to normal cells after bleomycin treatment. These data support the idea that circulating lymphocytes in trisomy 21 patients have a shorter average life span or a younger average age.

Bleomycin↗
PubMed1984

[Immunohistochemical study of ischemic neuronal damage with antiserum to tubulin, a microtubular protein].

The limitation of conventional histological methods to demonstrate ischemic change of neurons in early phase has been a major drawback in histopathological and pathophysiological studies of cerebral ischemia. Cellular metabolism is disturbed immediately after cessation of the regional circulation and rapid alterations in macromolecular and ultrastructural integrity in neurons may take place before any evidence of histopathological changes could be detectable. To demonstrate ischemic change of neurons more sensitively on a histological level, we applied immunohistochemical method using antiserum to tubulin, a protein of microtubules. As this organelle has been implicated in several important cellular functions such as control of cell shape, intracytoplasmic transport of materials or synaptic transduction, immunohistochemical alterations in microtubules may indicate structural as well as functional damage of neurons. In order to study the ischemic change in neurons, the posterior communicating artery of a gerbil brain was occluded by the method previously reported by us, and the hippocampus, which is one of the most vulnerable structures of the brain to ischemia, was observed. Five or 30 minutes after occlusion, animals were sacrificed by decapitation. Brains were removed, cut coronary vessels and fixed in ethanol-acetic acid (95:5). Tubulin used for this study was extracted from normal gerbil brains and specific antiserum was raised in goats Peroxidase-antiperoxidase method was performed on paraffin sections. Immunohistochemical distribution of tubulin in a normal gerbil brain demonstrated by the present method was in good accordance with the reported electronmicroscopical distribution of microtubules.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Interaction of bis- and mono-N-nitrosoureas with rat liver chromatin in vitro.

The effects of nine N-nitrosoureas (three bis-N-nitrosoureas, five mono-N-nitrosoureas and chloroethyl-N-nitrosourea) on the template activity of rat liver chromatin and Escherichia coli DNA were compared. The template activity of rat liver chromatin was inhibited by some N-nitrosoureas that have relatively strong alkylating activity. The inhibitory effects with respect to E. coli DNA were stronger than those with respect to rat liver chromatin. The inhibitory effects had a tendency to decrease with increasing length of the alkyl chain. The template activity of rat liver chromatin was slightly increased by some N-nitrosoureas, potassium cyanate and some alkyl isocyanates. The chromatin reacting with 1,1'-ethylene-bis-(1-nitrosourea) was more sensitive than the control chromatin to DNase 1 and Staphylococcal nuclease. The solubility of chromatin carbamoylated by 1,1'-ethylene-bis-(1-nitrosourea) was clearly higher than that of control chromatin in the presence of magnesium or calcium ion.

Animals↗
PubMed1984

[The effect of a novel TRH analog (DN-1417) on postictal seizure inhibition in amygdaloid kindled cats].

Anticonvulsant and prophylactic effects of DN-1417, a novel TRH analog, were reported previously in kindled cat preparations which had been established as an experimental model of epilepsy. This study was conducted to examine an effect of DN-1417 on postictal events including postictal seizure inhibition (PSI). A recycling paradigm consisted of 8 amygdaloid stimuli at 1 hour intervals was applied to evaluate the PSI. Six of bilateral amygdaloid kindled cats were used. In control session, the left amygdala had been stimulated at final electroconvulsive threshold at 1 hour intervals in all cats. In drug session, the cats were pretreated with DN-1417 (4 mg/kg, i.v.) and exposed to recycling paradigm 20 minutes after the administration. The interval of each session was at least 2 weeks EEG recordings and behavioral observations were carried out at the same time. Effects of TRH tartrate (4 mg/kg, i.v.) on PSI was also investigated in 2 cats at the same paradigm. PSI was significantly prolonged and postictal EEG silence was significantly shortened by DN-1417. The pretreatment of TRH tartrate showed an prolongation of PSI in 2 cats respectively. These results suggest that administrated TRH analog or TRH may inhibit an occurrence of subsequent seizures and prevent the epileptic status.

Amygdala↗
PubMed1984

[Ultrastructural and pathological studies of chondromyxoid fibroma of bone].

Histological and electron microscopic studies were carried out on a chondromyxoid fibroma in the right femur of a 8 years old boy. Although chondromyxoid fibroma contained chondroid, fibrovascular and myxoid components, the chondroid zone was transformed into myxoid zone through degeneration of chondroblastic tumor cells. Fibroblastic tumor cells gave no findings specific for fibroblast and fibrocyte on electron microscopy. Most primitive tumor cells were found in the fibromatoid zone. These cells have probably differenciated to fibroblastic and chondroblastic tumor cells. Histiocytes were gathered around the blood vessel. Despite the native of chondromyxoid fibroma as one of the bone tumor of cartilagenous deviation, it showed the characteristics of histiocytic tumors in part.

Cell Transformation, Neoplastic↗
PubMed1984

[Adjuvant chemotherapy for osteosarcoma in Japan--past, present and future].

The therapeutic results for osteosarcoma were very discouraging before 1970 in Japan despite many modes of treatment. In 1960, Miki introduced the regional perfusion technique into the treatment of osteosarcoma, and in 1963, Akaboshi pioneered the intraarterial infusion technique. By these methods, a five-year survival rate about 30% was achieved during the period from 1971 to 1976. In Japan, the five-year disease-free survival rate will soon exceed 50% thanks to intensive multi-drug adjuvant chemotherapy, considering the therapeutic results of 117 cases of JOOG treated during 6 years from 1975 to 1980 and 114 cases included in the Group Study of Osteosarcoma treated during 8 years from 1973 to 1981. In most cases, ablative surgery must still be considered the standard method of treatment. However, the importance of preoperative adjuvant chemotherapy is emphasized because limb-saving operations have become an increasingly common feature in the management of osteosarcoma as a result of the recent advances achieved by intensive multi-drug adjuvant chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1983

Caldesmon, a calmodulin-binding, F actin-interacting protein, is present in aorta, uterus and platelets.

Caldesmon, a protein originally found in chicken gizzard, was concluded also to be present in bovine aorta, uterus, and human platelets by demonstration of a protein with the following properties: (a) Ca2+-dependent calmodulin-binding; (b) binding to F actin in such way that the binding was broken on Ca2+-dependent binding of calmodulin; (c) cross-reactivity in immune blotting procedures with affinity-purified antibody against gizzard caldesmon; (d) similar subunit Mr-values on SDS-gel to those of gizzard caldesmon. Like gizzard caldesmon, platelet caldesmon was composed of two polypeptide bands of Mr 150 000 and 147 000, but caldesmon in aorta and uterus gave a single band of Mr 150 000. A polypeptide of Mr 165 000 that was immunologically distinct from caldesmon but, like caldesmon, bound to calmodulin and F actin in a flip-flop fashion, was also demonstrated in aorta and uterus.

Animals↗
PubMed1983

Immunohistochemical localization of creatine kinase BB-isoenzyme in human brain: comparison with tubulin and astroprotein.

The distribution of creatine kinase BB-isoenzyme in the human central nervous system (CNS) was investigated immunohistochemically and the findings were compared with the distributions of tubulin and astroprotein. Creatine kinase BB-isoenzyme existed both in neurons and astrocytes, and was universally distributed within the CNS. Tubulin was visualized only in the neuronal elements, namely perikarya, dendrites and axons, while astroprotein was exclusively visualized in astrocytes. A combination of immunohistochemistry for structural and soluble proteins may be a useful tool for the investigation of pathophysiological conditions within the CNS.

Astrocytes↗