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Biomedical subjects

H Kikuchi

Publications and source records attributed to H Kikuchi.

At least 325 records · Page 18Linked to original sources
PubMed1995

No negative feedback regulation between plasma CCK levels and luminal tryptic activities in patients with pancreatic insufficiency.

The study was conducted on five healthy subjects and six patients with calcifying pancreatitis (CP) and steatorrhea. Following overnight fasting, one tube each was placed in the stomach and the upper of the small intestine, respectively. Through the gastric tube, a test meal that included 30 g of fat (total calories, 625 kcal, 500 mL) was infused over a span of 30 min. Every 30 min (up to 150 min), fluid samples in the upper small intestine were collected and chilled, and the amylase, trypsin, and lipase levels were determined. In addition, in the case of the CP patients, a high-potency pancreatin preparation was infused into the stomach together with the test meal. In order to determine the plasma CCK level, blood sample were collected before test meal infusion and at 10, 20, 30, 45, 60, 90, 120, and 150 min subsequent to infusion. The plasma CCK was extracted using a Sep-Pak C-18 cartridge and analyzed with radioimmunoassay using an OAL-656 antibody. The result was converted to the CCK-8 level and expressed in pg/mL. The enzyme activities in the upper small intestine of the CP patients after test meal administration amounted to 22.8 (amylase), 10.8 (trypsin), and 16.9% (lipase) compared with the corresponding figures for the normal subjects. Following administration of a high-potency pancreatin in patients with CP, enzyme activities in the upper small intestine increased to 132.2 (amylase), 38.7 (trypsin), and 45.3% (lipase) compared with levels in the normal subjects. However, the healthy subjects and the CP patients, both with and without treatment with supplementary exogenous enzymes, all exhibited similar profiles in the plasma CCK response to stimuli. Based on these findings, we concluded that a negative feedback mechanism does not exist between the tryptic activity of the upper small intestine and the CCK secretory response in patients with chronic pancreatitis.

Adult↗
PubMed1995

Effect of selenium on malignant tumor cells of brain.

Some reports have demonstrated that selenium can inhibit tumorigenesis in some tissues of animal. However, little is known about the inhibitory effect on malignant tumor cells of brain. The purpose of our study was to determine the biological effect of selenium on growth of rat glioma and human glioblastoma cell lines. Cell lines C6 and A172 were obtained from Japanese Cancer Research Resources Bank, Tokyo, Japan (JCRB). Cells were cultured in Dulbecco's Modified Eagle's Medium (DMEM) supplemented with 10% fetal calf serum at 37 degrees C in a humidified atmosphere of air and 5% CO2. Antiproliferative effects of selenium were evaluated using growth rate assay quantifying cell number by MTT assay. An antiproliferative effect of selenium was found in two cell lines, which was more effective on human A172 glioblastoma and less effective on rat C6 glioma.

Animals↗
PubMed1995

Amino acid transport after transient global ischemia in rats: quantitative autoradiographic study using 3-[125I]iodo-alpha-methyl-L-tyrosine.

We studied the influence of reperfusion on amino acid transport of the brain after transient global ischemia in rats. The animals were subjected to 30-min four-vessel occlusion according to the procedures developed by Pulsinelli prior to recirculation for 3, 6, 24, 48 and 72 h. We used 3-[125I]iodo-alpha-methyl-L-tyrosine as an autoradiographic tracer for selective cerebral amino acid transport maker. Following 30-min global ischemia, uptakes of 3-[125I]iodo-alpha-methyl-L-tyrosine were significantly (P < 0.05) lower in substantia nigra, striatum and ventral tegmental area (6, 24, 48 and 72 h post-reperfusion), but significantly (P < 0.05) higher in cortex and thalamus (3 and 6 h post-reperfusion). The influence of transient global ischemia on cerebral amino acid transport manifested region-specific three different patterns; namely, suppression, acceleration and no change in amino acid transport. The influence of transient ischemia on catecholamine-synthesizing brain sites is most remarkable.

Amino Acids↗
PubMed1995

A novel anti-apoptosis serum factor that down-regulates fas-mediated apoptosis.

The Fas antigen (CD95) is a receptor for apoptotic cell death signals. Human T Jurkat cells that express the Fas molecule on the cell surface are sensitive to cytotoxic anti-Fas monoclonal antibodies (mAbs). We report here that fetal calf serum (FCS) contains a novel factor (SAF: Serum Anti-Apoptosis Factor) that suppresses Fas-mediated apoptosis of Jurkat cells. The apoptotic cell death of Jurkat cells induced by an anti-Fas mAb was accelerated when FCS was removed from the medium. Depletion of serum itself did not induce apoptosis without the mAb. The apoptosis-suppressing activity was not seen in neonatal calf or adult bovine serum, suggesting that the SAF activity was developmentally regulated. The anti-apoptosis activity was not detected in any fraction of FCS obtained on gel filtration chromatography. However, the activity was recovered in a certain fraction on the addition of calf serum, suggesting that the anti-apoptotic activity of SAF requires other serum factor(s). We purified SAF from FCS using an assay system reconstituted with calf serum, and raised antibodies (Abs) to it in rabbits. The anti-SAF Ab inhibited the apoptosis-suppressing activity, indicating that SAF is a key factor for the anti-apoptotic activity of FCS.

Animals↗
PubMed1995

Importance of 6-O-sulfate groups of glucosamine residues in heparin for activation of FGF-1 and FGF-2.

Treatment of the pyridinium salts of heparin with N-methyltrimethylsilyl-trifluoroacetamide (MTSTFA) in pyridine for 2 h at various temperatures caused specific 6-O-desulfations from trisulfated disaccharide units to various degrees without detectable depolymerization or other chemical changes. In order to assess the importance of 6-O-sulfate groups in N-sulfated glucosamine (GlcNS) residues to promote FGF-1 and FGF-2 activities, various 6-O-desulfated (6-O-DS-) heparins were quantitatively examined for activity as enhancers or inhibitors of specific FGF-1- and FGF-2-induced proliferation of BALB/c3T3 clone A31 (A31) cells and the chlorate-treated cells. The present results suggested that a high content of 6-O-sulfate groups in GlcNS residues was required for activation of FGF-1, but not FGF-2. However, complete 6-O-desulfation of trisulfated disaccharide units in heparin resulted in loss of the ability to activate FGF-2, although the desulfated product bound strongly to FGF-2.

Animals↗
PubMed1995

Assessment of cancer susceptibility in humans by use of genetic polymorphisms in carcinogen metabolism.

Prevention is an important and effective measure for reducing death caused by cancer. Thus information on individual susceptibility to cancer is valuable in suggesting high risk individuals to avoid intake of carcinogenic substances and receive frequent physical screening. To this end, polymorphisms found within cytochrome P450 (CYP) genes implicated in the metabolism of procarcinogens are expected to be good genetic targets in assessing human cancer susceptibility. We have found polymorphisms in the CYP2E1 and CYP1A1 genes associated with lung cancer susceptibility, though there were some discrepancies from observations made by other investigators. Discrepancies among investigators from different regions, however, are very common in these pharmacogenetic studies. We present an explanation for these discrepancies, difficulties associated with prediction of relative risk of individuals, and future directions.

Carcinogens↗
PubMed1995

Acute myeloblastic leukaemia without Philadelphia chromosome developing after interferon therapy for chronic myelocytic leukaemia with Philadelphia chromosome.

We report a patient who developed Philadelphia chromosome negative acute myeloblastic leukaemia with trisomy 8 and trisomy 11 after receiving treatment with alkylating agents and interferon for chronic myelocytic leukaemia positive for Philadelphia chromosome. Leukaemic cells were positive for myeloperoxidase and expressed CD13, CD33 and DR; some expressed CD2, CD4 and CD34. The fluorescence in situ hybridization method revealed that bcr-abl fusion genes were absent from > 90% of the bone marrow cells. The major bcr rearrangement was not detected by Southern blot analysis. We conclude that the leukaemic cells negative for Philadelphia chromosome may have developed as a result of treatment with alkylating agents and interferon in the present case.

Aged↗
PubMed1995

[Detection and quantitation of cytomegalovirus DNA in plasma from patients with cytomegalovirus pneumonia].

Detection and semiquantitation of cytomegalovirus (CMV) DNA in plasma from 17 immunocompromised patients with CMV pneumonia diagnosed histopathologically, 15 CMV seropositive patients without CMV pneumonia and 24 CMV-seropositive healthy volunteers were evaluated, using the polymerase chain reaction (PCR). CMV DNA was detected in plasma from all of 17 patients with CMV pneumonia, from 1 of 15 patients without CMV disease, but from none of healthy volunteers. One patient without CMV disease exhibited positive CMV DNA by PCR 2 days before death. Plasma CMV DNA was negative at the time of admission in all patients, however, it became positive 1-28 days (mean, 14 days) before the onset of CMV pneumonia in 16 patients. The amount of viral DNA in plasma were 10(3) - 10(5) copies/ml (mean, 10 (4.0) copies/ml) when first detected by PCR. At the onset of CMV pneumonia, they were 10(4)-10(6)(mean, 10(5.3) copies/ml), and increased with disease progression and decreased with disease improvement because of treatment with antiviral agents. We succeeded in detection of CMV DNA in plasma before the development of CMV pneumonia, and showed the amount of viral DNA reflected the extent of active CMV pneumonia. Thus, PCR amplification of CMV DNA in plasma is a useful tool for early diagnosis and monitoring of immunocompromised patients.

Adult↗
PubMed1995

A novel nitrite reductase gene from the cyanobacterium Plectonema boryanum.

The gene (nirA) for nitrite reductase was cloned from the nonheterocystous, filamentous cyanobacterium Plectonema boryanum. The predicted protein consists of 654 amino acids and has a calculated molecular weight of 72,135. The deduced amino acid sequence from positions 1 to 511 is strongly similar to the entire sequence of the ferredoxin-dependent nitrite reductases from other phototrophs, while the remainder of the protein is unique to the Plectonema nitrite reductase. The C-terminal portion of the protein (amino acids 584 to 654) is 30 to 35% identical to [2Fe-2S] ferredoxins from higher plants and cyanobacteria, with all of the four Cys residues involved in binding of the [2Fe-2S] cluster in the ferredoxins being conserved. Immunoblotting analysis of the extracts of P. boryanum cells showed that the NirA polypeptide has an apparent molecular mass of 75 kDa. An insertional mutant of nirA lacked the 75-kDa polypeptide, had no nitrite reductase activity, and failed to grow on nitrate and nitrite, indicating that the novel nirA is the sole nitrite reductase gene in P. boryanum and that the NirA polypeptide with the ferredoxin-like domain is the apoprotein of the functional nitrite reductase. As in Synechococcus sp. strain PCC7942, nirA is the first gene of a large transcription unit (> 7 kb in size) and is repressed by ammonium and derepressed simply by deprivation of ammonium from the medium. The development of nitrite reductase activity was, however, found to require the presence of nitrate in the medium.

Amino Acid Sequence↗
PubMed1995

Serum fatty acid composition in normal Japanese and its relationship with dietary fish and vegetable oil contents and blood lipid levels.

A survey was conducted on 110 normal Japanese adults (55 men and 55 women) to determine their caloric intake, dietary fat content and its origin (animal, plant, or marine). In addition, their blood lipid levels and fatty acid compositions were examined. Men in their 30s-50s consumed 2,600-2,800 calories and 60 g of fats, while women in the same age range consumed 2,000-2,200 calories and 52-58 g of fats. In both sexes, caloric, fat, and cholesterol intakes were lower for those in their 60s but protein and crude fiber consumption remained generally unchanged. When the dietary fats were classified according to origin, men and women in their 30s were found to consume less oil of marine origin. This appeared to be the result of a western style diet for Japanese adults in their 30s. Compared with men, women exhibited lower blood lipid levels. As age increased, the total cholesterol level of the blood rose in women. Thus the blood lipid level was generally equal in the two groups in their 60s. There was a positive correlation between the blood eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels and dietary consumption of fish oil. The marine/plant lipid ratio was positively correlated with the blood EPA/arachidonic acid ratio. Therefore, it was believed that the origin of the dietary fats consumed is a factor in determining the blood fatty acid profile. The linoleic acid (18:2), arachidonic acid (20:4), and 18:2 + 20:4 contents were negatively correlated to the total cholesterol level in the blood but positively correlated to the HDL-cholesterol level. Polyunsaturated fatty acids (18:2 + 20:4 + 20:5 + 22:6) were negatively correlated with the blood triglyceride level. From the findings presented above, we concluded that dietary fats not derived from animal sources should be classified into fish and vegetable oils to evaluate their dietary significance. We also noted that Japanese in their 30s consume less fish oil, indicating the western trend in their dietary lipid consumption.

Adult↗
PubMed1995

Identification of Mycobacterium avium complex isolated in eastern and central Japan by using DNA probes.

An attempt was made to identify Mycobacterium avium and Mycobacterium intracellulare in the M. avium intracellulare complex (MAC) isolated in the Tohoku (38 strains) and Tokai (30 strains) districts of Japan by using DNA probes which are specific for M. avium, M. intracellulare and M. tuberculosis complex, respectively. The incidence of M. avium infection (82%) by far exceeded that of M. intracellulare infection in the Tohoku district of eastern Japan. In the Tokai district of central Japan, the incidence of M. avium infection (57%) were slightly larger than that of M. intracellulare infection. Five of 68 strains showed a positive reaction with two different DNA probes. Thus a possibility of mixed infection could not be ruled out, because reference strains showed a positive reaction with only one species-specific DNA probe.

DNA Probes↗
PubMed1995

Cerebellar hemangioblastoma with intracystic hemorrhage--case report.

A 45-year-old male presented with sudden onset of severe headache, mild disorientation, and gait disturbance due to intracystic hemorrhage from a cerebellar hemangioblastoma. He was successfully treated with ventricular drainage followed by total removal of the tumor. Reported cases of intracranial hemangioblastoma with massive hemorrhage show male predominance, tend to be solid rather than cystic, and occur in supratentorial more than infratentorial locations. Thin-walled and dilated vessels in the present and other cases were a possible cause of hemorrhage. Massive hemorrhage from hemangioblastoma is rare but needs prompt treatment because of the relatively high mortality.

Capillaries↗
PubMed1995

Primary malignant lymphoma of the central nervous system--report of four long-term survivors.

Four of 47 patients treated between 1977 and 1993 for histologically confirmed primary malignant lymphoma of the central nervous system (non-Hodgkin's type of B-cell origin) achieved long-term survival for more than 5 years with a good quality of life. Three have remained disease-free for 9-12.5 years. The fourth achieved complete remission for more than 5 years before death from tumor recurrence. All four patients were treated with a standard therapeutic regimen, consisting of radiotherapy (50-60 Gy local and 30-40 Gy whole brain irradiation) followed by four to six courses of chemotherapy with cyclophosphamide, vincristine, adriamycin, and prednisolone at 4- to 8-week intervals. No further treatment was performed after remission had been obtained. No specific predictors for long-term survival including sex, age, tumor location, multiplicity of lesions, histology, or treatment modality was identified. All four patients showed an immediate tumor response to radiation. We recommend chemotherapy at increasing intervals as part of the post-therapeutic management of long-term, disease-free patients.

Adult↗
PubMed1995

Dolichoectasia of the middle cerebral artery--Case report.

A 59-year-old female with a previous history of head injury presented with mild occipitalgia due to dolichoectasia of the middle cerebral artery (MCA). Initial examination by computed tomography and angiography using the usual projections suggested a terminal internal carotid artery saccular aneurysm. However, angiography by the reverse Waters view excluded a saccular aneurysm. Superselective angiography using a microcatheter revealed the complex tortuous course of the MCA due to dolichoectasia. She was discharged and has remained asymptomatic. Superselective angiography is extremely useful for the diagnosis of dolichoectasia localized in the MCA.

Carotid Artery, Internal↗
PubMed1995

Activation and possible involvement of calpain, a calcium-activated cysteine protease, in down-regulation of apoptosis of human monoblast U937 cells.

An active form of calpain mu, a low-Ca(2+)-requiring intracellular cysteine protease, was detected using a cleavage site-directed antibody in apoptotic human monoblast U937 cells treated with tumor necrosis factor-alpha and interferon-gamma. Membrane-permeable calpain inhibitors accelerated apoptosis of U937 cells thus induced and suppressed the activation of procalpain. These findings suggest that calpain down-regulates apoptosis by shutting off the intracellular signals for cell death.

Journal Article↗
PubMed1995

Immediately detachable coil for aneurysm treatment.

We developed an endovascular coil that is instantly detached by high-frequency electrical current. By applying the electrical current, a polyvinyl alcohol junction between the coil and the delivery wire is disrupted by heat within a second. This detachment system was shown to be reliable in the treatment of experimental aneurysms.

Animals↗