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Biomedical subjects

T Hase

Publications and source records attributed to T Hase.

At least 19 recordsLinked to original sources
PubMed1997

Three-dimensional helical computed tomography with intravenous cholangiography for sclerosing cholangitis manifested as postcholecystectomy symptom.

A 46-year-old woman who had upper abdominal pain 10 years after cholecystectomy, and who had incidental sclerosing cholangitis (SC), was investigated by three-dimensional helical computed tomographic (3-DHCT) cholangiography with contrast medium, because endoscopic retrograde cholangiography (ERC) was unsuccessful and a second ERC was not permitted by the patient. The cholangiogram demonstrated annular strictures of the bilateral hepatic duct at the confluence of the common hepatic duct, and dilatation of the left intrahepatic biliary duct. Although we could not clarify the cause of the biliary tract deformity at the time of the 3-DHCT, the tentative diagnosis of postcholecystectomy deformity of the biliary tree led to successful treatment by right liver lobectomy and hepaticojejunostomy. Histologic findings were compatible with SC. From this experience and the literature, we suggest that 3-DHCT cholangiography with contrast medium can contribute to the preoperative diagnosis of morphological changes in the biliary tree in patients with postcholecystectomy symptoms.

Cholangiography↗
PubMed1997

A nitrate-inducible ferredoxin in maize roots. Genomic organization and differential expression of two nonphotosynthetic ferredoxin isoproteins.

We have identified and characterized a nitrate-inducible ferredoxin (Fd) in maize (Zea mays L.) roots by structural analysis of the purified protein and by cloning of its cDNA and gene. In maize Fd isoproteins are encoded by a small multigene family, and the nitrate-inducible Fd was identified as a novel isoprotein, designated Fd VI, which differed from an Fd I to Fd V identified to date. In the roots of seedlings cultured without nitrate, Fd VI was undetectable. However, during the induction of the capacity for nitrate assimilation, the amount of Fd VI increased markedly within 24 h. Concurrently, the level of transcript for Fd VI increased, but more quickly, reaching a maximal level within 2 h with kinetics similar to those of nitrite reductase and Fd-NADP+ reductase. Fd III was constitutively expressed in roots, and no such changes at the protein and mRNA levels were observed during the nitrate induction. In the 5' flanking region of the gene for Fd VI only, we identified NIT-2 motifs, which are widely found in genes for enzymes related to nitrogen metabolism. These data indicate that Fd VI is co-induced with the previously characterized enzymes involved in nitrate assimilation, and they suggest that the novel Fd isoprotein, distinct from the constitutively expressed Fd, might play an important role as an electron carrier from NADPH to nitrite reductase and other Fd-dependent enzymes in root plastids.

Amino Acid Sequence↗
PubMed1997

[Simultaneous ambulatory electrocardiography and pulse oximetry].

We developed a system for 24-hour ambulatory recording of blood oxygenation (SpO2) and electrocardiography (ECG). Using this system, we studied 10 healthy volunteers and 7 patients with chronic pulmonary diseases. The system incorporated a portable pulse oximeter (SM50) manufactured by Fukuda Denshi KK; the first and second channels were used to record ECG data and the third was used to record SpO2 data. An SpO2 sensor (Dispo-sensor D-25; Nellcor Inc.) was applied to the fourth of fifth finger. The SpO2 data (MicrO2; Siemens AG) were digitized and stored in the ambulatory recording device; the ECG was recorded simultaneously. The data were analyzed with a model DMW-9000H analyzer (Fukuda Denshi KK). A custom-designed program was also used, to remove noise errors. In the healty volunteers, SpO2 was at least 90% for the entire 24 hours. In all the patients, SpO2 fell below 90% at rest during the night or after a 15-minute walk. Transient atrial tachycardia was observed in 3 patients, and during the tachycardia the SpO2 was low. The number of extra ventricular beats divided by the total number of beats increased more in the patients than in the healthy volunteers (1.21 +/- 0.89 vs 0.6 +/- 0.3%, p < 0.05). SpO2 did not change significantly in the patients. In outpatients and in patients receiving home health care, the present system facilitates simultaneous diagnosis of respiratory failure an arrhythmias. In patients with chronic pulmonary diseases desaturation may cause transient atrial tachycardia.

Adult↗
PubMed1997

[Usefulness of directional coronary atherectomy as a bail-out device for acute closure after coronary angioplasty].

The usefulness of directional coronary atherectomy (DCA) as a bail-out device for acute closure (reclosure) after percutaneous transluminal coronary angioplasty (PTCA) was evaluated. PTCA was performed in 1,023 patients (182 with acute myocardial infarction) between January 1993 and January 1994 in our hospital. Thirty-one patients (11 with acute myocardial infarction) suffered acute closure (reclosure) after PTCA. In six patients (five with acute myocardial infarction), DCA was performed as a rescue treatment for acute closure (reclosure). In three of these patients, angioscopy was performed before DCA, which demonstrated intimal tear and some thrombi although coronary angiography showed no evidence of thrombus. Bail-out DCA was successful in all six patients without complications. DCA is useful as a bail-out device for acute closure (reclosure) after PTCA when the thrombus is not massive.

Angioplasty, Balloon, Coronary↗
PubMed1996

Molecular identification and characterization of cytosolic isoforms of glutamine synthetase in maize roots.

In maize, a small multigene family encodes the cytosolic isoforms of glutamine synthetase (GS), and five cDNAs, designated pGS1a, pGS1b, pGS1c, pGS1d, and pGS1e, have been cloned (Sakakibara, H., Kawabata, S., Takahashi, H., Hase, T., and Sugiyama, T. (1992) Plant Cell Physiol. 33, 49-58; Li, M., Villemur, R., Hussey, P. J., Silflow, C. D., Gantt, J. S., and Snustad, D. P. (1993) Plant Mol. Biol. 23, 401-407). This report describes the identification and enzymatic characterization of the cytosolic isoforms of GS in maize roots, namely GS1 and GSr. The purified isoforms, as well as recombinant enzymes that had been overexpressed in Escherichia coli, were analyzed by capillary liquid chromatography/electrospray ionization-mass spectrometry, and GS1 and GSr were identified as the products of the GS1a/GS1b and GS1c/GS1d genes, respectively. Upon the addition of ammonia to the culture medium, significant amounts of GSr accumulated and a preferential increase in GS synthetase activity, as compared to GS transferase activity, was found in the root extract. Assays with the purified recombinant enzymes confirmed that the specific biosynthetic and synthetase activities of GSr were 1.6-fold higher than those of GS1. Marked differences in stability were also found between the two isoforms: GSr was more sensitive to heat than GS1 and octameric aggregates of the subunits of GSr were easily dissociated to monomers than those of GS1 at low concentrations of Mn2+ and Mg2+ ions. These characteristics of the ammonia-induced isoform of GS seem to be physiologically important for the primary assimilation of external ammonia by roots.

Ammonia↗
PubMed1996

Bell pepper fruit fatty acid hydroperoxide lyase is a cytochrome P450 (CYP74B).

Fatty acid hydroperoxide lyases cleave a C-C bond adjacent to a hydroperoxide group in lipoxygenase derived lipid hydroperoxides to form short-chain aldehydes and oxo-acids. Previously, we showed that fatty acid hydroperoxide lyase from bell pepper fruits is a heme protein whose spectrophotometric properties greatly resemble a cytochrome P450. In order to ascertain the relationship of it to the P450 gene family, we have cloned cDNA encoding fatty acid hydroperoxide lyase from immature bell pepper fruits. The cDNA encodes 480 amino acids, and shares homology with P450s mostly at the C terminus. The heme binding cysteine is recognizable at position 441. The most closely related P450 is allene oxide synthase (CYP74A), with which it has 40% identity. It qualifies the lyase as a member of a new P450 subfamily, CYP74B. From this finding, the enzyme is thought to be a novel member of P450 specialized for the metabolism of lipid peroxides.

Aldehyde-Lyases↗
PubMed1996

Release of chromaffin granular content from staphylococcal enterotoxin B (SEB)-treated and -untreated PC12 cells.

The release of chromaffin granular content from staphylococcal enterotoxin B (SEB)-treated and -untreated PC12 cells was studied by electron microscopy. The treatment of the cells with SEB at the concentration of 20 micrograms/ml caused marked increase of the chromaffin granules that either bound to the plasma membrane by the characteristic rods, measuring 15 to 20 nm in length and showing a tubular structure, or budded off at the free cell surface, surrounded by a layer of rod-containing cytoplasm and enclosed by the plasma membrane. The binding between the granular and plasma membranes by the rods did not lead to membrane fusion and exocytosis of the granular content. Many of the bound granules showed vesiculation with loss of the electron-dense core material; at the same time, some of the binding rods contained intraluminal electron-dense material similar to the granular core material. These findings suggested that the electron-dense material (i.e., norepinephrine) of the bound granules was released extracellularly through channels within the rods. Although the granules were bound to the plasma membrane with equal frequency at the free and contiguous cell surfaces, the granular budding occurred only at the free cell surface, indicating that it occurred incidentally to some granules bound at the free cell surfaces. On the basis of the morphological observations, it is postulated that the electron-dense material of the bound granule is selectively released extracellularly through the rods, leaving the vesiculated granules behind in the cytoplasm. The same mode of release of the granular content was observed, though less frequently, in the untreated control cells. No morphological evidence that indicated that the granular content was released extracellularly by exocytosis was found in the treated and control cells. The present observations indicated that the SEB treatment of PC12 cells stimulated the binding of chromaffin granules to the plasma membrane by the rods and the budding of the bound granules at the free cell surface.

Animals↗
PubMed1996

Identification of the chlB gene and the gene product essential for the light-independent chlorophyll biosynthesis in the cyanobacterium Plectonema boryanum.

We cloned a 6.0-kb HindIII fragment from the cyanobacterium Plectonema boryanum using the chloroplast chlB (ORF513) gene of the liverwort (Marchantia polymorpha) as a probe. An open reading frame (ORF508) encoding a polypeptide of 508 amino acid residues was found within the nucleotide sequence of the 4,437-bp HindIII-EcoRV subfragment. The deduced amino acid sequence of ORF508 shows very high similarity to that encoded by the liverwort chlB gene (72.7%). A mutant, YFB14, in which ORF508 was inactivated by the insertion of a kanamycin-resistance cartridge, was unable to synthesize chlorophyll, accumulating protochlorophyllide in darkness while synthesizing chlorophyll normally in the light. Thus, the chlB gene is the third gene that is essential for the light-independent reduction of protochlorophyllide. The other two genes are chlL and chlN, and the results suggest that the light-independent protochlorophyllide reductase consists of at least three subunits, which are encoded by chlL, chlN and chlB. Using an antiserum prepared against a ChlB-6xHis fusion protein expressed in Escherichia coli, we detected a protein with an apparent molecular weight of 58,000 in the membrane fraction of the cyanobacterium. These results indicate that either the cytoplasmic or thylakoid membranes could be the site of the light-independent reduction of protochlorophyllide.

Algal Proteins↗
PubMed1996

Evaluation of multi skin test in colorectal cancer patients and effects of serum immunosuppressive factor and cytokine production of peripheral mononuclear cells.

Decreased skin reactions using five kinds of recall antigens correlate d with the stage of colorectal cancer. Immunosuppressive factors in the serum (IS index) increased with the progression of the stage in cancer patients, but interleukin (IL)-I and IL-2 production in peripheral mononuclear cells (PBMC) did not correlate with the advance of the disease. In patients with low immunosuppressive factors, the score of skin reactions was significantly higher than that in patients with high immunosuppressive factors. Increased serum immunosuppressive factors seem to reduce skin reactions in the patients. Furthermore, significant difference in skin reaction score was observed between patients with high IL-1 production of PBMC and patients with low IL-1 production of PBMC. These results suggest that skin reaction might be controlled by serum immunosuppressive factors and IL-1 production of PBMC, and that the score of skin reaction using multirecall antigens is a useful parameter to learn the host immunity in colorectal cancer.

Adult↗
PubMed1996

[Pulmonary typical carcinoid with metastases to pulmonary hilar, and mediastinal lymph nodes].

A 50-year-old woman was admitted to our hospital complaining of recurrent bloody sputum and hemoptysis. Chest X-ray films showed an infiltrative shadow in the left lower lung field. Chest computed tomograms showed a nodular tumor shadow near the left B8 and this tumor shadow was found between A8 and A9 by pulmonary arteriography. Bronchoscopic examination revealed a red coagulum in the left B8 and cytologic examination of broncho alveolar lavage fluid revealed atypical squamous cells. With a clinical diagnosis of squamous cell carcinoma of the lung, a left lower lobectomy with hilar and mediastinal lymph node dissection was done. A milk-white tumor was found in the lower lobe of the resected lung. The pathological diagnosis of the resected tissue specimen was carcinoid, accompanied by pulmonary, hilar, and mediastinal lymph node metastases. Reduced immunofluorescence by Chromogranin A and serotonin staining were further evidence that the tumor was atypical. This case is very interesting in that the tumor metastasized to the lung and lymph nodes, even-though it was pathologically typical.

Carcinoid Tumor↗
PubMed1995

Isotope dilution gas chromatographic-mass spectrometric method for the determination of unconjugated lignans and isoflavonoids in human feces, with preliminary results in omnivorous and vegetarian women.

We describe an isotope dilution gas chromatographic-mass spectrometric (GC/MS) method for the identification and quantitative determination of the lignans enterolactone, enterodiol, and matairesinol and the isoflavonoids daidzein, equol, O-desmethylangolensin, and genistein in feces. Following the addition of deuterated internal standards for all compounds, the feces samples are extracted and purified in several ion exchange chromatographic steps. Following formation of trimethylsilyl ethers, the samples are analyzed by combined capillary column GC/MS in the selective ion monitoring mode and corrected for all losses during the procedure using the deuterated internal standards. Results on the reliability of the method and values for nine Finnish omnivorous and nine vegetarian women are presented.

4-Butyrolactone↗
PubMed1995

Platelet talin is phosphorylated by calyculin A.

Calyculin A and okadaic acid, potent and cell permeable inhibitors of type 1 and type 2A protein phosphatases, inhibit platelet aggregation and secretion. However, the relationship between phosphatase inhibition and inhibition of platelet function is not well understood. We found that in unstimulated platelets, talin (P235) was phosphorylated at threonine residues by calyculin A. Furthermore, the extent of talin phosphorylation by calyculin A was closely correlated with its inhibition of thrombin-induced platelet aggregation. Since the binding of talin to platelet glycoprotein IIb/IIIa complex has been shown to be affected by its phosphorylation, these results suggest that type 1 and/or type 2A protein phosphatases may play a role in the regulation of membrane-cytoskeleton interaction through dephosphorylation of talin.

Alkalies↗
PubMed1995

Successful management of infantile hepatic hilar hemangioendothelioma with obstructive jaundice and consumption coagulopathy.

A 4-month-old boy with benign hemangioma of the porta hepatis is described. Obstructive jaundice and consumption coagulopathy developed, which were treated by percutaneous transhepatic drainage (PTHD), without resection of the tumor or bypass surgery. Because of tumor regression, the patient has remained free of symptoms even after the PTHD tube was removed. Because juvenile hemangioma is a benign tumor and occasional spontaneous regression is known to occur (as in our case and other reports), it is suggested that complete resection or bypass surgery is not necessary for juvenile hemangioendothelioma, even with obstructive jaundice, if bile drainage is adequately maintained.

Cholestasis↗
PubMed1995

Effect of diet on lignans and isoflavonoid phytoestrogens in chimpanzees.

Diphenolic compounds belonging to the classes of lignans and isoflavonoids have been identified in urine of man and animals, including the chimpanzee. Some of these compounds, formed by intestinal bacteria from plant lignans and phytoestrogens, have been shown in animal studies to exhibit biological activities that suggest they could function as cancer-protective compounds. The effect of diet on urinary excretion of these compounds in the adult male chimpanzee has been studied. It was found that the chimpanzees consuming their regular food excreted large amounts of the isoflavonoid phytoestrogens, equol (mean +/- SE) (127.5 +/- 34.0 nmol/mg cr.) and daidzein (20.7 +/- 9.0 nmol/mg cr.) and the lignan, enterolactone (14.1 + 3.5 nmol/mg cr.). Small amounts of the lignan, enterodiol, (0.4 +/- 0.2 nmol/mg cr.) were also excreted. On all other four test diets (high protein, high carbohydrate, high vegetable, and high fat), the excretion was less, particularly on a high fat diet where the excretion of all diphenolic compounds was reduced by more than 90% to a level observed in omnivorous human subjects or women with breast cancer. These results suggest that diet profoundly influences the excretion of both animal lignans and phytoestrogens in urine. Because non-human primates are particularly resistant to mammary and genital carcinoma on estrogen treatment, the present data suggest that the very high levels of phytoestrogens and lignans as found during exposure to the regular diet may partially account for why these primates are so resistant to hormonal manipulations to induce cancer.

Animals↗
PubMed1995

Lignan and isoflavonoid conjugates in human urine.

Lignans and isoflavonoids are two groups of diphenolic phytoestrogens of plant origin which have gained increasing interest because of their possible cancer protective properties. High excretion of these compounds occur in populations at low risk of breast, prostate and colon cancer consuming either high amounts of whole-grain (lignans and some isoflavonoids) or soy products (isoflavonoids and some lignans). We determined the pattern of conjugation of the phytoestrogens in four urine samples from vegetarian or semivegetarian women and in two samples from men. Seven compounds were investigated: enterodiol, enterolactone, matairesinol, diadzein, equol, genistein and O-desmethylangolensin. The fractions quantified are the free fraction, mono- and disulfate, as well as the mono-, di- and sulfoglucuronide fractions. For the fractionation and purification we used ion-exchange chromatography and the determination of the concentrations of each compound in all fractions was done by isotope dilution gas chromatography-mass spectrometry (GLC-MS) using deuterated internal standards of all diphenols. More than 60% of all compounds determined, occurred in the monoglucuronide fraction. Daidzein, enterodiol and equol are excreted to a relatively high extent as sulfoglucuronides and genistein as diglucuronide. We conclude that the general pattern of lignan and isoflavonoid conjugates in urine is similar to that of endogenous estrogens.

Estrogens↗
PubMed1995

Genistein, a dietary ingested isoflavonoid, inhibits cell proliferation and in vitro angiogenesis.

Consumption of a plant-based diet can prevent the development and progression of chronic diseases that are associated with extensive neovascularization. To determine whether prevention might be associated with dietary derived angiogenesis inhibitors, we have fractionated urine of healthy human subjects consuming a plant-based diet and examined the fractions for their abilities to inhibit the proliferation of vascular endothelial cells. One of the most potent fractions contained several isoflavonoids, which we identified by gas chromatography-mass spectrometry and subsequently synthesized. Of all synthetic compounds, the isoflavonoid genistein was the most potent and inhibited endothelial cell proliferation and in vitro angiogenesis at half maximal concentrations of 5 and 150 mumol/L, respectively. Moreover, genistein inhibited the proliferation of various tumor cells. Genistein excretion in urine of subjects consuming a plant-based diet is in the micromolar range, which is 30-fold higher than that of subjects consuming a traditional Western diet. The high concentrations of genistein in urine of vegetarians and our present results suggest that genistein may contribute to the preventive effect of plant-based diet on chronic diseases, including solid tumors, by inhibiting neovascularization and tumor cell proliferation. Thus genistein may have important applications in the treatment of solid tumors and angiogenic diseases.

Animals↗
PubMed1995

Molecular cloning and sequencing of a cDNA encoding alanine-glyoxylate aminotransferase 2 from rat kidney.

Alanine-glyoxylate aminotransferase (AGT) 2 is a pyridoxal 5'-phosphate dependent, mitochondrial enzyme which, in the rat, is expressed at a high level in the kidney. The amino acid sequences of nine tryptic and seven CNBr peptides of the rat kidney AGT2 were determined. Three overlapping cDNAs encoding the AGT2 were cloned on the basis of its partial amino acid sequences by means of a polymerase chain reaction-based approach involving rat kidney poly(A)+ RNA. The complete cDNA sequence comprised 1,919 bases, and contained a 1,536-base open reading frame which encodes a polypeptide of 512 amino acid residues with a putative presequence consisting of 39 amino acid residues at the amino terminus, giving a precursor protein with a molecular mass of 57,150 Da. The sequence of AGT2 exhibits significant homology with neither peroxisomal AGT1 from human liver nor mitochondrial AGT1 from rat liver. However, the sequence of AGT2 exhibited 30.8, 29.2, and 27.1% identity with those of Escherichia coli 4-aminobutyrate aminotransferase, rat ornithine aminotransferase, and Pseudomonas cepacia 2,2-dialkylglycine decarboxylase, respectively. The active site sequences were also well conserved among these aminotransferases. AGT2, thus, is more similar to the other aminotransferases than to AGT1. The results suggest that the rat kidney AGT2 may play a biological role in amino acid metabolism distinct from that of AGT1.

Alanine Transaminase↗