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Biomedical subjects

M Morimoto

Publications and source records attributed to M Morimoto.

At least 55 records · Page 3Linked to original sources

Human CD36 deficiency is associated with elevation in low-density lipoprotein-cholesterol.

To find out whether CD36 plays a role in the human lipoprotein metabolism, we studied lipoprotein profiles in subjects with CD36 deficiency. Apparently healthy Japanese volunteers (n = 790) were classified by flow cytometry into three groups of normal (platelet and monocyte CD36+, n = 741, 93.8%), type-II deficiency (platelet CD36- and monocyte CD36+, n = 45, 5.7%), and type-I deficiency (platelet and monocyte CD36-, n = 4, 0.5%). At least one of reported mutations in the CD36 gene was found in all four subjects with type-I deficiency and in 23 of the 45 subjects with type II. Among 779 subjects (731 normals, 44 type II, and four type I) with serum triglyceride levels of <400 mg/dL, serum total cholesterol and low-density lipoprotein (LDL) cholesterol were significantly elevated in type-II deficiency (P = 0.0095 and 0.0382 versus normal, respectively, Scheffe's F-test), while differences were not significant in triglyceride and high-density lipoprotein-cholesterol. Similar tendency was observed in type-I deficiency, although the differences were not statistically significant because of small sample size. We conclude that CD36 deficiency elevates LDL cholesterol, indicating a contribution of CD36 to LDL metabolism.

CD36 Antigens↗

Transforming growth factor-beta(1) increases the expression of lectin-like oxidized low-density lipoprotein receptor-1.

Lectin-like oxidized low-density lipoprotein (Ox-LDL) receptor-1 (LOX-1) is a novel cell-surface receptor for Ox-LDL, which can be expressed by vascular endothelial cells, smooth muscle cells, and macrophages. On the other hand, transforming growth factor (TGF)-beta(1), which plays crucial roles in vascular remodeling and the pathogenesis of atherosclerosis, has been shown to inhibit expression of class A scavenger receptors and CD36 in macrophages. Here we provide the evidence that TGF-beta(1) (0.1-10 ng/mL) induces LOX-1 protein and mRNA expression in both bovine aortic endothelial cells and smooth muscle cells in a dose- and time-dependent fashion, probably at the transcriptional level. TGF-beta(1) also upregulates LOX-1 mRNA expression in murine peritoneal macrophages. Thus TGF-beta(1) can highly induce LOX-1 expression in vascular endothelial cells, smooth muscle cells, and macrophages, suggesting that TGF-beta(1) appears one of the key regulators that modulates expression of scavenger receptors.

Animals↗

Modification of cullin-1 by ubiquitin-like protein Nedd8 enhances the activity of SCF(skp2) toward p27(kip1).

The periodic expression of cell cycle proteins is important for the regulation of cell cycle progression. The amount of CDK inhibitor, p27(kip1), one such protein, seems to be regulated by the ubiquitin-proteasome system. The ubiquitin ligase (E3) toward p27(kip1) is thought to be SCF(skp2). The activity of SCF(skp2) was increased by the addition of Roc1 protein to the complex. Furthermore, the ubiquitination of p27(kip1) seemed to be dependent on the phosphorylation of T187 of p27(kip1) because the mutant T187A was not ubiquitinated at all in an in vitro ubiquitination system. Cullin-1, a component of SCF, is modified by ubiquitin-like protein Nedd8. The modification site of cullin-1 was shown to be K696 because the K696R mutant was not modified. When the effect of the Nedd8 modification on the SCF(skp2) activity toward p27(kip1) was investigated, the activity was markedly decreased by using the Nedd8-unmodified mutant cullin-1 (K696R), indicating that the modification may play an important role on the SCF(skp2) activity toward p27(kip1).

Amino Acid Sequence↗

Insect antifeedant flavonoids from Gnaphalium affine D. Don.

The antifeedant flavonoids, 5-hydroxy-3,6,7,8,4'-pentamethoxyflavone (1), 5-hydroxy-3,6,7,8-tetramethoxyflavone (2), 5,6-dihydroxy-3, 7-dimethoxyflavone (3), and 4,4',6'-trihydroxy-2'-methoxychalcone (4), have been isolated from cudweed Gnaphalium affine D. Don (Compositae). Four natural flavonoids showed insect antifeedant activity against the common cutworm (Spodoptera litura F.). These flavonoids were detected in small amounts in the plant by HPLC analysis, but these natural compounds had strong antifeedant activity against the common cutworm. On the other hand, 4 was detected in a large amount in the plant, but this compound had only a slight activity. Therefore, these natural compounds were regarded as one of the plant's defensive systems against phytophagous insects along with the woolly plant surface. As for the structure-activity relationship, it is an advantage for antifeedant activity to have no oxy-substituents on the B-ring of the flavonoid but have an ether linkage such as a pyran in the chemical structure.

Animals↗

Relationships between the onset of pustulosis palmaris et plantaris, periodontitis and bacterial heat shock proteins.

Relationships between the onset of pustulosis palmaris et plantaris, periodontitis and heat shock proteins were studied by using enzyme-linked immunosorbent assay to examine levels of immunoglobulin G (IgG) against Escherichia coli GroEL, a recombinant DnaJ of Actinobacillus actinomycetemcomitans heat shock protein, a synthetic peptide made from the 180th to the 188th amino acids of Mycobacterium bovis BCG Hsp65, and a recombinant human Hsp60, in sera obtained from 43 pustulosis palmaris et plantaris patients judged to have chronic infectious diseases of the oral cavity. We found that the titers of IgG against E. coli GroEL and A. actinomycetemcomitans DnaJ in the sera from pustulosis palmaris et plantaris patients were significantly higher than those in the control group, whereas the titers of IgG against the synthetic M. bovis Hsp65 and the recombinant Hsp60 did not differ significantly. Periodontal therapy and extraction of teeth with periapical infectious resulted in remission of pustulosis palmaris et plantaris and a statistically significant reduction in the levels of IgG against E. coli GroEL in 9 of the 22 patients (41%) examined. We also found that the IgG levels against A. actinomycetemcomitans DnaJ in 6 serum samples of 16 (37%) were reduced, but not significantly, after the treatment. These results suggest that the IgG responses to heat shock proteins partially induced by oral bacteria may be related to the onset of pustulosis palmaris et plantaris in some patients.

Adult↗

Serum total bile acid level as a sensitive indicator of hepatic histological improvement in chronic hepatitis C patients responding to interferon treatment.

BACKGROUND AND METHODS: Serum total bile acid (TBA) levels are used clinically as a sensitive and reliable index of hepatobiliary diseases. In the present study, to assess the clinical usefulness of determining TBA in interferon (IFN)-treated patients, changes in liver function test values, including TBA and liver histology, were examined in 36 chronic hepatitis C patients for 3 years after a sustained response to IFN treatment. RESULTS: Alanine aminotransferase and gamma-glutamyl transpeptidase values significantly decreased during the period of IFN treatment compared to the same measures before IFN treatment. Albumin, cholinesterase, total cholesterol and platelet count values temporarily decreased during IFN treatment, then increased significantly and reached a plateau 6-12 months after the end of IFN treatment. The zinc sulphate turbidity test and TBA values began to decrease during IFN treatment and continued to decrease during the 3-year follow-up period. The histological activity index of the liver (Knodell's score) significantly decreased, whereas the staging score was unchanged 1 year after the end of IFN treatment. In patients who had a TBA value > 10 micromol/L before IFN treatment, a significant correlation was observed between the decrease of TBA and liver histology grading score. CONCLUSIONS: A decrease in serum TBA level reflected histological improvement in the liver more precisely than did changes in the other liver function test values following IFN therapy.

Adult↗

Detection of vascular endothelial growth factor and its receptor expression in human hepatocellular carcinoma biopsy specimens.

BACKGROUND: Vascular endothelial growth factor (VEGF) exerts its actions on the microvasculature, by interacting with specific endothelial cell receptors, and thus, contributes to angiogenesis and growth in many tumours. METHODS: Using nested reverse-transcription-polymerase chain reaction, we examined the biopsy specimens of 14 patients with human hepatocellular carcinoma (HCC) and cirrhosis, for the expression of hepatic VEGF, and the VEGF receptors KDR and fit-1. To avoid the influence of hypoxia or ischaemia induced by surgical manipulation, we used biopsy specimens of the liver instead of resected specimens. RESULTS: Vascular endothelial growth factor mRNA expression was detected in the tumour portion of the specimens in 13 of 14 patients (93%), and in the corresponding non-tumour portion of the specimens in eight patients (57%; P= 0.08). No differences were found between the tumour portion and the corresponding non-tumour portion in relative concentrations of VEGF mRNA. However, mRNA expression of the VEGF receptors, KDR and fit-1, was detected in 14 (100%) and 11 (79%) of the tumour portions, respectively, and in four (29%) and five (36%) of the corresponding non-tumour portions, respectively (chi2 test: KDR, P< 0.01; fit-1, P= 0.08). The relative concentration of KDR mRNA in the tumour portions was significantly higher than in the non-tumour portions (Mann-Whitney U-test: P<0.001) but no differences were detected for fit-1. CONCLUSIONS: KDR mRNA is significantly overexpressed in HCC lesions and could be associated with the angiogenesis and tumour growth induced by VEGF.

Aged↗

Posttreatment sequelae of palliatively treated cerebral arteriovenous malformations.

OBJECTIVE: Posttreatment sequelae of palliatively treated cerebral arteriovenous malformations (AVMs) were studied to evaluate the significance of these nonradical treatments. METHODS: Between 1987 and 1997, 46 patients with cerebral AVMs were managed with treatments such as partial embolization, radiosurgery, subtotal resection, or feeder ligation alone. Their AVMs were not radically resected because of difficulties in radical treatment, hesitance to treat eloquent area lesions, or residual nidi after subtotal obliteration. The patients' posttreatment sequelae were evaluated. The duration of follow-up ranged from 0.5 to 169 months (mean, 49.4+/-39.8 mo). RESULTS: Twenty-six bleeding episodes from AVMs were documented in 18 patients. The annual risk of bleeding in this palliatively treated group was 14.6%. Persistent progressive neurological deficit was observed in one patient. Major neurological deficits occurred in 10 patients (23.3%), and the mortality rate was 9.3%. CONCLUSION: Palliative treatments cannot prevent bleeding and may even worsen the posttreatment course compared with the natural history of cerebral AVMs. A more conservative indication is required in recommending palliative treatment alone.

Carotid Arteries↗

[Properties of antitumor activity of vinorelbine tartrate, a new vinca alkaloid antitumor agent].

Vinorelbine (VNR) is a new vinca alkaloid derivative semi-synthesized by Potier et al. The antitumor activity of VNR was superior to other vinca alkaloid antitumor agents, and the neuro-toxicity of VNR was weaker than those of other vinca alkaloids. In nude mice xenografted human tumor models, VNR showed antitumor activity against eight of eleven tumor models (non-small cell lung cancer: 4/4, breast cancer: 2/3, colon cancer: 0/2, stomach cancer: 2/2). Especially, VNR showed tumor-regressive activity against LC-6 non-small cell lung cancer and MX-1 breast cancer. The antitumor activity of VNR against non-small cell lung cancer was superior to that of vindesine (VDS), which had been one of the key drugs of non-small cell lung cancer in the clinic. In combination chemotherapy, VNR plus cisplatin (CDDP) was better than VDS plus CDDP, which had been one of the standard regimens of non-small cell lung cancer chemotherapy. The potent antitumor effect of VNR with minor neurotoxicity was explained by VNR having stronger activity on mitotic microtubules than axonal microtubules. It was supposed that less activity of VNR against mitotic microtubules would be related to different composition of microtubule-associated TAU isoforms in the two types of microtubules. In non-small cell lung cancer, VNR resulted in a significantly higher response rate than VDS. In combination with CDDP, VNR resulted in longer survival than VDS with a significant log-rank test. In advanced breast cancer, VNR resulted in a high response rate in 1st line and 2nd line treatment. VNR is effective in combination with chemotherapeutic agents such as anthracycline, fluorouracil and Taxol. In Japan, the clinical trial in breast cancer is now ongoing.

Adenocarcinoma↗

Accumulation of calcium and phosphorus in the mitral valve in comparison with the abdominal aorta and the scaphoid bone.

To clarify why calcification of the mitral valve occurred, the authors chose the abdominal aorta and the scaphoid bone among many arteries and bones, and they studied both relationships in element contents between the mitral valve and the abdominal aorta and between the mitral valve and the scaphoid bone. The subjects consisted of 11 men and 8 women, ranging in age from 52 to 96 yr. The accumulation of calcium and phosphorus occurred progressively with aging in the mitral valve, whereas it became the highest in the sixties in the abdominal aorta and did not increase thereafter. The accumulation of calcium and phosphorus occurred in the abdominal aorta earlier than the thoracic aorta, in which it became remarkable in the seventies. It should be noted that in regard to the accumulation of calcium and phosphorus, no significant correlations were found between the mitral valve and the abdominal aorta. It is suggested that calcification of the abdominal aorta is not essentially accompanied by calcification of the mitral valve. The scaphoid bone was chosen among many bones consisting mainly of spongy bone and the relationship was examined between the calcium content in the mitral valve and the bone mineral density of the scaphoid bone. It was found that there was a low relationship between them. Therefore, it is suggested that a part of the surplus calcium released from bones is deposited in the mitral valve.

Aged↗

Histological analysis of murine colitis induced by dextran sulfate sodium of different molecular weights.

In this study, we examined the relationship between the molecular weight of dextran sulfate sodium (DSS) and the features of colitis in a DSS-induced mouse model of human ulcerative colitis. DSS at three different molecular weights, 5 kD, 40 kD and 500 kD, was used in this study. DSS was administered in drinking water at 5% (w/v) to 6-7-week-old female BALB/c mice. After 7 days of treatment with DSS, the large intestine was examined histopathologically. Colitis was characterized by a loss of crypts, infiltration of inflammatory cells into the mucosa and submucosa, edema of the submucosa, erosion and ulceration and was observed in mice given the 5 kD and 40 kD forms but not the 500 kD. In the 5 kD group, colitis was observed predominantly in the cecum and upper colon. Colitis in the 40 kD group was more severe than that in the 5 kD group, and in the 40 kD group it was more severe in the lower colon than in the upper colon. These findings suggest the molecular weight of DSS to be an important factor in the murine model of colitis.

Animals↗

Magnetic resonance imaging of calvarial eosinophilic granuloma with pericranial soft tissue reaction--case report.

A 4-year-old girl presented with an eosinophilic granuloma in the cranial vault. Magnetic resonance (MR) imaging showed the mass as slightly low intensity on T1- and high intensity on T2-weighted images. The pericranial soft tissue was densely enhanced after gadolinium-diethylenetriaminepenta-acetic acid infusion. The mass was soft and successfully removed. Histological examination disclosed Langerhans' cell histiocytosis. MR imaging is useful for the diagnosis of calvarial eosinophilic granuloma with soft tissue involvement.

Acute-Phase Reaction↗

Persistence of hepatitis B surface antibody levels after vaccination with a recombinant hepatitis B vaccine: a 3-year follow-up study.

We conducted a 3-year follow-up study of 2,008 individuals for the persistence of antibody levels after vaccination with a recombinant hepatitis B vaccine. At 1 month after vaccination had been completed 96.3% of subjects had acquired protective HB surface (HBs) antibody titers on passive hemagglutination assay (PHA) of 2, and 3 years after completion of the vaccination 63.1% had acquired similar titers. The titer decreased below this level after 3 years in 34.5% of subjects who had initially acquired protective antibody titers. The mean acquired HBs antibody titer on PHA was 2 at 1 month and 2 at 3 years after completion of the vaccination. The regression line for these changes was expressed as logY = 1.800-0.24X by the least squares method. The antibody level was estimated to decrease to 2 at 37 months and to seronegativity at 75 months. On the basis of the relationship between PHA antibody titers and the period of their persistence, the persistence of antibody levels after vaccination with a recombinant vaccine can be estimated from the acquired antibody titer determined 1 month after completion of the vaccination, as with plasma-derived vaccines.

Adult↗

Comparison of occurrence of oro-maxillo-facial tumor types in different regions of the People's Republic of China.

The frequencies of oro-maxillo-facial tumors, by type, seen at the Guangxi Medical College Hospital were surveyed in order to compare different regions of the People's Republic of China. Computer analysis was performed on data for all oro-maxillo-facial tumors, as confirmed by the hospital between 1957 and 1987, inclusive. The results were then used in a comparative study with those of five other medical colleges. Among a total of 4,052 cases, there were 1,593 benign tumors, 2,049 malignant tumors and 410 unknown tumors. Tumors derived from the epithelium were the most common type (42.0% of the total), whereas in the other five medical colleges the mean corresponding proportion was 27.8%, the difference being significant (p < 0.05). Epithelial tumors were also the most common type of malignant tumor (70.5% of the total), whereas the corresponding proportion reported by the other five institutions was 60.6%, which was also significantly different (p < 0.05). The proportion of malignant tumors among the total was more than 50.6%, which was higher than that reported by the other five colleges. This study shows that epithelium-derived tumors and malignant tumors were encountered more frequently at Guangxi Medical College than at the other five medical colleges in China.

Carcinoma↗

Color Doppler sonography for evaluating response to transcatheter arterial embolization and percutaneous ethanol injection therapy and for detecting recurrence of hepatocellular carcinoma.

Eighty-six patients (mean age, 63 years) with 92 hepatocellular carcinomas (2.0 cm or greater in diameter; mean +/- SD, 3.5 +/- 1.6 cm) underwent color Doppler sonography before and after transcatheter arterial embolization and after subsequent percutaneous ethanol injection for (1) identification of pulsatile flow in the residual tumor area after transcatheter arterial embolization, (2) evaluation of therapeutic effectiveness of combined transcatheter arterial embolization and percutaneous ethanol injection, and (3) detection of recurrence during follow-up evaluation. Before and 2 weeks after transcatheter arterial embolization, color Doppler sonography revealed pulsatile flow in 76 (82.6%) and 43 (46.7%)lesions, respectively. After percutaneous ethanol injection, tumor stains in these lesions completely disappeared on digital subtraction angiography (gold standard). During follow-up study (3 to 45 months), digital subtraction angiography revealed recurrence in 73 patients (38 local recurrences and 19 new lesions [2.0 cm or greater]), whereas color Doppler sonography revealed pulsatile flow in 76.3% (local) and 63.2% (new) (not significant). Color Doppler sonography was useful for complying with our three objectives, especially for detecting local recurrence during follow-up evaluation.

Aged↗

[Clinical study of cerebral blood flow in unilateral chronic subdural hematoma measured by 99mTc-HMPAO SPECT].

Cerebral blood flow (CBF) measured by 99mTc-HMPAO SPECT before operation was studied in 60 patients with unilateral chronic subdural hematoma. The regional CBF was measured in 26 regions of the fronto-occipital 10 cortices, putamen, thalamus and cerebellar hemisphere on both sides. Sixty cases with unilateral chronic subdural hematoma were classified into four groups on the basis of clinical symptoms: 17 cases with headache (headache group), 34 cases with hemiparesis (hemiparesis group) and 9 cases with consciousness disturbance or dementia (consciousness disturbance group), and into three groups on the basis of the degree of midline brain shift on MRI: 7 cases of mild shift group, 24 cases of moderate shift group and 29 cases of severe shift group. The average CBF in 60 patients in each region indicated that the regional CBF was reduced in frontal, occipital cortices and cerebellum on the non-hematoma side, and in putamen and thalamus on the hematoma side. In the headache group, the regional CBF reduction on the non-hematoma side was found in only frontal and occipital cortices compared with the corresponding regions on the hematoma side. In the hemiparesis group, the regional CBF was reduced in frontal and occipital cortices on the non-hematoma side and in putamen and thalamus on the hematoma side. The part of CBF reduction in both hemispheres was also noted in the hemiparesis group. In the consciousness disturbance group, the CBF reduction was markedly noted in whole brain. The CBF reductions in frontal and occipital cortices on the non-hematoma side and in putamen, thalamus and cerebellum on the hematoma side was not mutually related with the degree of midline brain shift. We concluded that the disturbance of CBF in chronic subdural hematoma was started from frontal and occipital cortices on the non-hematoma side observed in the headache group, and which was extended to putamen and thalamus on the hematoma side and a part of both hemispheres observed in the hemiparesis group. And such disturbance was finally observed as the CBF reductions in whole brain in the consciousness disturbance group.

Adolescent↗