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Biomedical subjects

M Ishikawa

Publications and source records attributed to M Ishikawa.

At least 343 records · Page 19Linked to original sources

Apolipoprotein A-1 of Japanese quail: cDNA sequence and modulation of tissue expression by cholesterol feeding.

Apolipoprotein (apo) A-1 cDNA was amplified by the reverse-transcriptase-polymerase chain reaction (RT-PCR). Primers were synthesized according to the nucleotide sequence of chicken apo A-1, and the identity of apo A-1 cDNA was confirmed by comparing with the N-terminal amino acid sequence. The open reading frame of apo A-1 cDNA consists of 795 nucleotides, and it is capable of coding a polypeptide of 264 amino acids. A comparison between quail and chicken apo A-1 revealed 94.5% homology in the nucleotide sequence and 91.7% homology in the amino acid sequence. There was a similar 11- or 22-amino acid repeat in quail apo A-1 as was the case for chicken apo A-1. Apo A-1 mRNA was evaluated to be 1.4 k in length and was expressed in various tissues of Japanese quail: the liver, small intestine, lung, kidney, heart, and muscle. A quantitative evaluation, however, revealed that the liver and small intestine were the major organs for apo A-1 synthesis, accounting for more than 90% of the total expression of apo A-1 mRNA. Besides apo A-1 mRNA (1.4 k in length), a transcript of 4.1 k was detected in all the tissues examined, with a magnitude ranging from 5 to 10% of the apo A-1 mRNA level. The effect of cholesterol level on the expression of apo A-1 mRNA was studied to address the physiological significance of apo A-1 in the liver, small intestine, and muscle. The level of cholesterol in the liver and breast muscle was increased by feeding with cholesterol and reached a saturation level at day 7. There was also a temporal rise of cholesterol level at day 7 in the small intestine. Dietary cholesterol increased the expression of apo A-1 mRNA two fold in both the liver and small intestine. This was not the case for breast muscle, in which the expression of apo A-1 mRNA was not modulated by the cholesterol level.

Amino Acid Sequence↗

Drinking habit as a base for blood pressure elevation--difference in epidemiological significance by beverage type.

To investigate whether blood pressure differs by taking preferred alcoholic beverage among habitual drinkers, systolic and diastolic blood pressure (SBP, DBP) were compared among groups with different beverage types in 563 middle-aged Japanese males using data from a cross-sectional health survey conducted from February, 1989 through March, 1991 in five areas of Japan. Mean values of SBP and DBP, adjusted for residence, age and body mass index (BMI), were significantly greater in 'exclusively sake' drinkers (adjusted SBP: 127.2 mmHg, adjusted DBP: 83.0 mmHg) and in 'exclusively shochu' drinkers (adjusted SBP: 127.5 mmHg, adjusted DBP: 84.2 mmHg) than in non-drinkers (adjusted SBP: 120.9 mmHg, adjusted DBP: 77.3 mmHg). Adjusted SBP and DBP of 'exclusively beer' drinkers (adjusted SBP: 121.9 mmHg, adjusted DBP: 79.1 mmHg) were significantly (for SBP: p = 0.016, for DBP: p = 0.008) lower than those of 'exclusively sake' drinkers. Similar patterns of blood pressure differences between five beverage types of habitual drinkers were found especially in the group with less than 150 g of weekly ethyl-alcohol consumption. Even after adding ethyl-alcohol consumption as a covariate among 479 habitual drinkers, the significant differences in adjusted SBP and DBP between 'exclusively beer' drinkers and 'exclusively sake' drinkers (for SBP: p = 0.032, for DBP: p = 0.044) were noted. These results may suggest that the effects of drinking on blood pressure differ by beverage type in middle-aged Japanese males.

Adult↗

A benign form of isolated angiitis of the central nervous system in puerperium: an identical disorder to postpartum cerebral angiopathy?

A case of isolated angiitis of the central nervous system (IACNS) in puerperium with a clinical presentation of bilateral frontal lobe hemorrhage is described. Her symptoms and arteriographic abnormalities were resolved by institution of corticosteroid. After cessation of steroid treatment she showed no evidence of relapse. This case indicates that there appears to be a benign form of IACNS, although the etiology of postpartum IACNS is not known. The postpartum cerebral angiopathy described in the literature may be an identical disorder, since there are no clinical points of specific distinction between them.

Adult↗

Neurotoxicity testing of a new bioactive bone cement.

Bioactive bone cement (BABC) is a novel artificial bone cement. It has some noteworthy characteristics that are applicable to neurological surgery. The toxicity of BABC to the nervous system was tested by implanting BABC and polymethylmethacrylate (PMMA) cement as a control at the parietal and the suboccipital regions of the skull in beagles. The auditory brainstem response (ABR) was tested before and after implantation. Sections of the cerebral cortex and the acoustic nerve were examined at 3 and 6 months after implantation. No abnormal ABR was found in any animals. Histological examination of the cerebral cortex and acoustic nerve demonstrated slight gliosis in both the BABC and PMMA cement groups, but no other abnormalities.

Animals↗

[A case of hemophagocytic syndrome with severe liver injury manifestating adult Still's disease].

In April 1988, a 23 year-old woman developed high fever, arthralgia, eruptions and splenomegaly. She was treated with non Steroid anti-inflammatory drugs, and the symptoms disappeared. In June 1991, she was diagnosed as adult Still's disease and treated with prednisolone. In July 1994, she was treated with pulse therapy methylprednisolone due to high fever, eruptions, arthralgia and the high levels of ferritin. However, due to the marked increase of serum transaminase and bilirubin levels, she was referred to University hospital. She developed hepatic failure after admission Bone-marrow puncture revealed hemophagocytosis. She died ten days after admission. She was diagnosed as hemophagocytic syndrome combined with acute hepatic failure.

Adult↗

Electrophysiological investigation of hemifacial spasm after microvascular decompression: F waves of the facial muscles, blink reflexes, and abnormal muscle responses.

In patients with hemifacial spasm, it has been said that the spasm is due to cross compression of the facial nerve by a blood vessel and that microvascular decompression (MVD) of the facial nerve is an effective treatment. The F waves, which result from backfiring of antidromically activated motor neurons of the facial motor nucleus, are indices of the excitability of the facial motor nucleus and are enhanced in patients with hemifacial spasm. Measuring blink reflexes and abnormal muscle responses (lateral spread), a characteristic sign of hemifacial spasm, has been used to investigate the mechanism of hemifacial spasm pathophysiologically. Thus the authors measured F waves of the facial muscle, blink reflexes, and abnormal muscle responses before and after MVD in patients suffering from hemifacial spasm to investigate the excitability of the facial motor nucleus and the course of the cure of hemifacial spasm after MVD. The authors obtained facial nerve-evoked electromyograms in 20 patients with hemifacial spasm before and after the MVD procedure. On the spasm side, the F waves and blink reflexes were enhanced preoperatively compared to those on the normal side and abnormal muscle responses were recorded in all patients. In 12 patients whose hemifacial spasm had not disappeared completely for 5.1 +/- 1.7 (mean +/- standard error) months following the MVD procedure, F waves were still enhanced significantly and abnormal muscle responses were still recordable, albeit at lower amplitude. Within 1 month after the hemifacial spasm had disappeared completely. F waves were still significantly enhanced in 17 patients and abnormal muscle responses were recorded in seven of 15 patients. Subsequently, the enhanced F waves and abnormal muscle responses disappeared completely. The authors' study supports the hypothesis that the cause of hemifacial spasm is hyperexcitability of the facial motor nucleus and suggests that additional surgery should not be performed for at least 2 years after MVD, because that period is necessary for the disappearance of the hyperexcitability of the facial motor nucleus.

Adult↗

New initiator system for bonding to dentin using methylcyclohexanedione.

As a part of a series of studies to examine the role of the initiator system in dentin bonding, the effectiveness of a new polymerization initiator system consisting of 2-methyl-1,3-cyclohexanedione (MCHD) and CuCl2 in dentin bonding was investigated in terms of the effects of dentin conditioners and CuCl2 concentration formulated in MMA/PMMA resins. Curing time and tensile bond strength to bovine dentin were measured using resins composed of MMA containing 0.001-0.03 wt% CuCl2 and PMMA powder containing 2 wt% MCHD. The dentin surfaces were treated with six conditioners consisting of 10 wt% phosphoric acid or citric acid containing 0-3 wt% FeCl3 or CuCl2. The bond strengths of about 10 MPa obtained under optimal conditions were comparable to those reported for tributylborane-initiated MMA resin which is one of the most effective bonding resins available. Thus, the resin using MCHD/CuCl2 system was concluded to be very effective for dentin bonding, especially when dentin was treated with acidic conditioners containing ferric or copper chloride.

Animals↗

Regression of an aggressive abdominal desmoid tumor in a patient with familial adenomatous polyposis by hyperthermoradiotherapy.

A case of huge desmoid tumor successfully treated by hyperthermoradiotherapy is described. A 23-year-old man with familial adenomatous polyposis was operated upon for a desmoid tumor in the mesenterium involving the right kidney and small intestine in 1988. In 1990, the tumor recurred and could not be resected because of the involvement of the vena cava. The tumor grew larger and larger, and occupied two-thirds of the right lower quadrant. Several therapies using sulindac, tamoxifen, prednisolone, indomethacin, luteinizing hormone-releasing hormone analogue, and ascorbate were all ineffective. Finally, the combination of radiation and hyperthermia was used over a 6-month period. At the end of the hyperthermoradiotherapy, the tumor in the abdominal wall was markedly reduced in size, and the protruded abdominal wall became flat. To our best knowledge, this is the first report of the successful treatment of a huge desmoid tumor by hyperthermoradiotherapy.

Adenomatous Polyposis Coli↗

[A case report of localized fibrous pleural mesothelioma].

A 47-year-old female with localized fibrous pleural mesothelioma arising from the visceral pleura of S2 of rt-upper lobe is reported. We demonstrated an indirect radiographic sign of pedunculation which was the change in position of the mass with the change in patient's position. The tumor was completely extirpated with a partial resection of the adjacent lung tissues through thoracotomy. Histopathologically, the tumor consisted of collagen fibers and small amount of fibroblast. Localized fibrous mesothelioma was recognized as benign with good prognosis. However, a few cases showing recurrence after resection were reported among them. So it was considered that this patient should be followed up carefully.

Female↗

[Secondary hepatic resections in a case of sigmoid colon cancer with multiple liver metastasis (H3) after successful continuous hepatic artery infusion chemotherapy oriented by in vitro chemosensitivity test].

A 43-year-old woman was admitted to our hospital for sigmoid colon cancer with multiple liver metastasis (H3). As preoperative CTAP (CT during arterial portography) examination showed 23 metastatic nodules in the whole liver, hepatic resections were not indicated. Angiographic findings showed that right and left hepatic arteries branched separately from the celiac artery. Sigmoid colon resection with D3 lymph node dissection and catheterization to the right hepatic artery via gastroduodenal artery were undertaken as a first operation. Continuous hepatic artery infusion chemotherapy with MMC, 5-FU oriented by in vitro chemosensitivity test (SDI test: Succinic Dehydrogenase Inhibition test) of primary tumor was performed 7 days after the first operation. After administration of MMC (40 mg) and 5-FU (16,500 mg), metastatic nodules in the right lobe almost disappeared except for the one tumor of S7, but the size and number of the nodules in the left lobes increased. At 10 months after the first operation, the left hepatic lobectomy and extirpation of only one tumor in the right lobe (S7) underwent. This case showed the usefulness of continuous hepatic artery infusion chemotherapy oriented by in vitro chemosensitivity test for multiple liver metastasis from colon cancer.

Adenocarcinoma↗

Direct colorimetric monoclonal antibody enzyme immunoassay for estradiol-17 beta in saliva.

We developed a direct microtiter plate enzyme immunoassay to measure estradiol-17 beta in saliva. The assay has a commercially available monoclonal antibody, raised against estradiol-17 beta-6-carboxymethyloximebovine serum albumin, and a homologous horseradish peroxidase conjugate measured colorimetrically. The detection limit (equivalent to B0-3 SD) is 365 amol/well or 7.3 pmol/L when 50-microL samples are assayed. Cross-reactivity with estrone and estriol, testosterone, or progesterone is < 0.2%. Estradiol-17 beta was measured in daily samples over five natural menstrual cycles and eight cycles stimulated as a preliminary to in vitro fertilization, and the concentrations and fluctuations found agreed with previously published data. This method gives results in approximately 3 h and may be useful for fertility monitoring and management.

Antibodies, Monoclonal↗

[Stent graft treatment for two cases of DeBakey IIIb dissecting aortic aneurysm].

Two patients with DeBakey IIIb dissecting aortic aneurysms were treated with transluminally placed endovascular stent grafts. Surgery was required for both patients because the false lumens were not thrombosed for several months. Stent graft devices composed of several units of self-expandable Z stents covered with ultra-thin woven Dacron were inserted through 18 Fr sheathes via femoral arteries. The stent grafts were deployed successfully and blood flow into the false lumens was reduced immediately and finally thrombosed without blood leakage from the entries. The endoluminal stent graft treatment is minimally invasive operation in comparison with former surgical operations, and is useful for aortic aneurysms especially in high risk patients. However, improvement of the stent graft devices, including the delivery systems such as the dilator, sheath and pushing rod, which are incomplete, and developing better devices, is required to reduce delivery failure and to make the stent graft treatment more reliable.

Aged↗

[A malignant rhabdoid tumor appearing simultaneously in the kidney and the brain of an infant: case report].

A 6-month-old female was admitted to the hospital with bad temper and decreased sucking power. CT scans revealed tumors in her right kidney and left cerebellum. The patient underwent right radical nephrectomy to excise the kidney tumor. The pathological diagnosis was malignant rhabdoid tumor (MRT). Seven days later, the patient underwent left suboccipital craniectomy for total excision of the cerebellar tumor. The cerebellar tumor existed extraaxially, and consisted of a solid mass lesion and a cystic lesion. Histological examination revealed that it was also a malignant rhabdoid tumor. A follow-up CT, 1.5 months after surgery, revealed a recurrence of the kidney tumor and metastasis to the chest wall and lung. The patient received 16.9 Gy radiotherapy to the abdominal tumor and chemotherapy with etoposide, carboplatin, and ifosfamide. However, she died of respiratory insufficiency 4 months after surgery, though neither recurrence nor metastasis was found in the brain. Nor was there evidence of leptomeningeal dissemination. MRT is a highly malignant tumor that occurs most frequently in the kidney. However, it can also occur in other tissues, including the brain. This tumor occurs most commonly in children under 2 years of age. There is a 3:2 male predominance. The median length of overall survival of MRT in the brain is 6 months. MRT contains nests or sheets of rhabdoid cells. A typical rhabdoid cell has an eccentric round nucleus with a prominent nucleolus and a plump cell body. MRT is composed entirely or partly of rhabdoid cells. Many MRTs have other components, such as PNET areas, mesenchymal area, and epithelial areas. For this reason, they are sometimes called atypical teratoid/rhabdoid tumors. MRTs in the brain contain fewer rhabdoid cell areas than MRT in the kidney. This makes diagnosing MRT in the brain more difficult. A careful search of the entire specimen for variations in pattern and cell type, along with application of immunohistochemical methods is the most useful method of obtaining a diagnosis. In our case, the cerebellar tumor consisted of rhabdoid cell areas, mesenchymal areas, and PNET areas. The cerebellar tumor contained fewer rhabdoid cell areas than the kidney tumor. However, the rhabdoid cell areas in the cerebellar tumor were almost the same as those in the kidney tumor. Furthermore, immunohistochemical staining was positive for vimentin and keratin in the rhabdoid cell areas. Therefore, we were able to make a diagnosis of MRT. It is possible that some of the previously reported cases diagnosed as CNS PNET were actually MRT in the brain, especially if the cases were associated with MRT in the kidney.

Cerebellar Neoplasms↗

Role of cardiac nonmyocytes in cyclic mechanical stretch-induced myocyte hypertrophy.

In cardiac hypertrophy or ventricular remodeling, not only the enlargement of myocytes but also interstitial or perivascular fibrosis are observed simultaneously, which suggests an interaction between cardiac myocytes and fibroblasts. In this study, we examined the mechanism of cyclic mechanical stretch-induced myocyte hypertrophy, highlighting the interaction between myocytes and cardiac nonmyocytes, mostly fibroblasts. Ventricular myocytes (MC) and cardiac nonmyocytes (NMC) were separately extracted from neonatal rat ventricles by the discontinuous Percoll gradient method and primary cultures of cardiac cells were prepared. Cyclic mechanical stretch was applied to the cultures with a Flexercell Stress Unit. In addition to cell size, we examined atrial natriuretic peptide/brain natriuretic peptide (ANP/BNP) production as the most sensitive biological markers for MC hypertrophy. Cyclic stretch did not induce hypertrophic responses in MC when they were cultured without NMC. In contrast, when MC were co-cultured with NMC, cyclic stretch induced further increase in ANP/BNP production (2.2-fold and 2.1-fold increases versus non-stretch group, after 48-h incubation). This increase in ANP/BNP production in the co-culture was significantly suppressed by CV-11974, an angiotensin II type 1 receptor antagonist. Moreover, ANP/BNP production in the co-culture was significantly suppressed by BQ-123, an endothelin A receptor antagonist, whether cyclic stretch was applied or not. This study raised the possibility that NMC mediate the hypertrophic effect of mechanical stress on MC by increasing endothelin production. It was also suggested that, in this process, angiotensin II is involved in the crosstalk between MC and NMC.

Angiotensin Receptor Antagonists↗

[Traditional remedy-induced Chinese herbs nephropathy showing rapid deterioration of renal function].

A 19-year-old female was referred to our hospital for azotemia and anemia. She had been taking a health food for atopic dermatitis for about three years. Urinalysis showed proteinuria, glycosuria and microscopic hematuria. Generalized aminoaciduria was observed. Moreover, severe anemia, azotemia, hypokalemia and hypophosphatemia were also observed. Renal biopsy specimen disclosed hypocellular interstitial fibrosis and degeneration of the proximal tubular epithelial cells. No remarkable changes were observed in the glomeruli. Aristolochic acid was detected in the health food. From these findings, she was diagnosed as having Chinese herbs nephropathy (CHN). Although consumption of the food intake was stopped, her renal function deteriorated rapidly. Previously, we reported that certain kinds of Chinese herbal drugs contain aristolochic acid and that the drugs should be prohibited if aristolochic acid is identified. However, we experienced a patient of CHN arising from traditional remedy, which was not proved to be safe. It should be awared that health foods may contain aristolochic acid.

Adult↗

Estrogen inhibits endothelin-1 production and c-fos gene expression in rat aorta.

In order to clarify the mechanism underlying the preventive effect of estrogen on atherogenesis, we investigated the role of estrogen in the regulation of endothelin-1 (ET-1) production and c-fos mRNA expression, which may contribute to atherogenesis. Plasma ET-1 concentration in ovariectomized rats (OVX) was twice as high as that in sham-operated female rats (Sham). Estradiol replacement in OVX rats (OVX + E) decreased plasma ET-1 to the level in Sham (Sham, 0.68 +/- 0.14; OVX, 1.32 +/- 0.14; OVX + E, 0.85 +/- 0.12 pg/ml). Metabolic clearance rate of ET-1 was similar in these three groups of rats, suggesting that the difference in plasma ET-1 was due to production rather than degradation. Measurement of immunoreactive ET-1 in tissue extract and immunohistochemical examination showed that expression of ET-1 in the aortic smooth muscle cells of OVX was increased. The expression of c-fos mRNA in the aorta was also increased in OVX compared with Sham and OVX + E. Intravenous infusion of ET-1 to Sham induced c-fos expression in the aorta, suggesting the contribution of ET-1 to c-fos expression. Tissue culture study revealed that DNA synthesis was increased in the aorta and femoral artery of OVX. These results suggest that inhibition of ET-1 and c-fos expression is involved in the anti-atherogenic action of estrogen.

Animals↗