Search PubMed⌕ Search

Biomedical subjects

T Uchida

Publications and source records attributed to T Uchida.

At least 541 records · Page 30Linked to original sources
PubMed1994

Immunologically and enzymatically distinct rat choline kinase isozymes.

The purification and characterization of choline kinase R1 expressed in Escherichia coli, using expression plasmid pKCK(H) constructed with rat liver choline kinase cDNA [Uchida, T. and Yamashita, S. (1992) J. Biol. Chem. 267, 10156-10162], were carried out. Choline kinase R1 was chromatographically, enzymatically, and immunologically distinct from rat brain choline kinase [Uchida, T. and Yamashita, S. (1990) Biochim. Biophys. Acta 1043, 281-288]. This report, for the first time, definitively demonstrates the presence of two types of choline kinase isozymes. Rat choline kinase was immunologically classified into choline kinases P and R. Choline kinase P was purified from rat brain as described previously. Choline kinase R was designated as the choline kinase generated from the choline kinase R gene for choline kinase R1. Choline kinases from cytosol were chromatographically separated into two fractions, that is, one passed through a Blue-Toyopearl column and the other was retained on it. The choline kinase retained on the Blue-Toyopearl column was highly purified from rat liver cytosol and characterized in this study, being found to comprise isoforms of choline kinase R, and a choline kinase which was immunologically similar to choline kinase P. Choline kinases P and R are co-distributed in rat tissues. The carcinogen, 3-methylcholanthrene, and hepatotoxic carbon tetrachloride increased the enzyme activity, and the transcript and protein levels of choline kinase R in rat liver. The relation of choline kinase isozymes to previously purified enzymes was discussed.

Animals↗
PubMed1994

Inhibitory effect of calcium channel blockers on growth of pancreatic cancer cells.

Calcium, which binds to calmodulin inside the cells, is an important mediator of various intracellular processes, including cell proliferation. We speculated that blockade of Ca2+ influx into the cells by Ca(2+)-channel blockers, such as phenytoin and verapamil, might affect the Ca(2+)-calmodulin pathway leading to suppression of cell growth. In this study, we examined the effect of phenytoin and verapamil on growth of two human pancreatic cancer cell lines, MIA PaCa-2 and CAV, in vitro and in vivo. Both phenytoin and verapamil inhibited growth of the two cell lines in a dose-dependent fashion. Phenytoin and verapamil each significantly prolonged doubling time of MIA PaCa-2 and the combination of the two drugs acted synergistically. The activity of ornithine decarboxylase, which is a rate-limiting enzyme of the polyamine pathway that is closely related to cell proliferation, was significantly inhibited by both drugs in a time-dependent fashion. Phenytoin, but not verapamil, inhibited growth of MIA PaCa-2 tumors xenotransplanted into nude mice, whereas both phenytoin and verapamil inhibited the growth of CAV tumors. Since phenytoin and verapamil are known to have fewer side effects than conventional antineoplastic drugs, these results suggest their possible use in novel therapeutic strategies.

Calcium Channel Blockers↗
PubMed1994

"Silent" hepatitis B virus mutants are responsible for non-A, non-B, non-C, non-D, non-E hepatitis.

Since the recent introduction of diagnostic kits for hepatitis C and E, some cases of non-A, non-B, non-C, non-D, non-E hepatitis (so-called hepatitis F) have been revealed. We attempted to demonstrate that so-called hepatitis F is caused by hepatitis B virus (HBV) variants. Polymerase chain reaction (PCR) was used to amplify serum HBV DNAs from 20 patients with acute hepatitis and 20 patients with chronic hepatitis who had been diagnosed as having so-called hepatitis F on the basis of conventional serological markers. The PCR technique successfully amplified HBV DNAs in 18 (90%) cases of acute hepatitis and 17 (85%) cases of chronic hepatitis. Sequencing of HBV DNAs of six patients (acute 3, chronic 3) revealed equally a T-to-C mutation of DR2 and an 8-nucleotide deletion of the 3'-terminus of the X gene coding region, giving rise to the generation of a C-terminally truncated X protein and probable damage to the enhancer II/core promoter elements. These mutations of the X gene coding region may lead to suppression of replication and expression of HBV DNAs. Thus virtually all cases of so-called hepatitis F appear to be caused by "silent" HBV mutants, at least in Japan.

Acute Disease↗
PubMed1994

Analysis of major surface polypeptides of Rickettsia japonica.

Major surface polypeptides of Rickettsia japonica migrated to the position of 120, 135, and 145 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, when the organisms were solubilized at room temperature. Two major bands at the position of 135 and 185 kDa were seen, when the organisms were solubilized by heating before electrophoresis. Heat-denaturation of the 120- and 145-kDa polypeptides in excised gel bands changed their mobility and caused them to migrate to 135- and 185-kDa positions, respectively. Two polypeptides at the 120-kDa position were demonstrated: one is a major heat-modifiable polypeptide and the other a minor heat-stable. Peptide mapping was performed to determine the identity between native and denatured polypeptides.

Bacterial Proteins↗
PubMed1994

Nucleotide sequence of polymerase chain reaction product amplified from Rickettsia japonica DNA using Rickettsia rickettsii 190-kilodalton surface antigen gene primers.

The PCR product amplified from Rickettsia japonica with the primer pair Rr 190.70p and Rr 190.602n of R. rickettsii 190-kDa antigen gene was cloned into M13mp19 RF DNA at the Eco RI site and sequenced by chemiluminescent DNA sequencing. The sequence revealed a molecular size of 533 base pairs (bp). The primer-flanking region of 491 bp, an open reading frame, was compared with the corresponding region of R. rickettsii, demonstrating 35 nucleotide substitutions in R. japonica. The sequence of primer portions in R. japonica DNA was also analyzed, revealing one nucleotide substitution in the Rr 190.70p and two in the Rr 190.602n portion. The homology in the overall sequence of PCR-amplified regions between R. japonica and R. rickettsii was 93% in nucleotide and 85% in putative amino acid structure. The sequence contains no cleavage site for the restriction endonuclease AfaI but two PstI sites giving three fragments of 121, 159, and 253 bp, which differentiated R. japonica from other spotted fever group rickettsiae in addition to R. rickettsii. The cleavage sites for endonucleases AluI, HinfI, and MunI that disappeared or appeared in the sequence by nucleotide substitution differentiated R. japonica from others, as did PstI. The estimation of molecular size of DNA fragments on polyacrylamide gel electrophoresis is discussed.

Antigens, Bacterial↗
PubMed1994

Adult T-cell leukaemia/lymphoma featuring a large granular lymphocyte leukaemia morphologically.

A 70-year-old man from an endemic area of human T-cell lymphotropic virus type I (HTLV-I) developed rapid generalized lymphadenopathy and abdominal tumours. The white blood cell count was 198.3 x 10(9)/l with 93% lymphocytes, 66.3% of which expressed large granular lymphocytes (LGLs). Bone marrow and lymph nodes were also infiltrated by LGLs. Surface markers were positive for CD4, CD25 and HLA-DR, and negative for CD3, CD8, CD16, CD56 and CD57. A monoclonal integration of HTLV-I proviral DNA was demonstrated on these LGLs by Southern blot hybridization analysis. This fact indicates that some adult T-cell leukaemia/lymphoma may morphologically present LGL leukaemia.

Aged↗
PubMed1994

Burkitt type leukaemia associated with multiple myeloma.

We describe a 77-year-old man with multiple myeloma (MM) who developed Burkitt type leukaemia (BTL) 16 months after the initial diagnosis of MM. MM was positive for CD10 with immunoglobulin (Ig) kappa, kappa Bence Jones protein (BJP) and a normal karyotype. BTL was positive for CD10, CD19, CD20 and HLA-DR with Ig mu and lambda, lambda BJP and a clonal abnormal karyotype of 46,XY,-13, t(8;14)(q24;q32),11q+,14q+, +mar. The patient died 9 d after diagnosis of BTL despite treatment with multiple agents. This is, to our knowledge, the first such case to be reported.

Aged↗
PubMed1994

Hepatitis C virus appears to replicate not only in hepatocytes but also in hepatocellular carcinoma cells as demonstrated by immunostaining.

Persistent infection with hepatitis C virus is a major risk factor for the development of hepatocellular carcinoma (HCC). It has been unclear whether hepatitis C virus replicates in HCC. A total of 39 hepatitis B surface-antigen-negative HCC were resected surgically at Nihon University Itabashi Hospital between January 1990 and December 1992. Of them, serum anti-hepatitis C was positive in 28 cases, negative in three and not examined in eight. The indirect immunoperoxidase technique was used for detection of the hepatitis C core antigen on formalin-fixed, paraffin-embedded sections. Positive staining was found within non-tumor hepatocytes in 22 (78.6%), one and four cases, respectively. Fourteen (58.3%) of these 24 cases, which were positively immunostained in non-tumor hepatocytes (three were excluded because of complete necrosis of HCC), were also stained for the core antigen in HCC cells. Core antigen was stained in both hepatocytes and HCC cells within the cytoplasm, diffusely or focally with varying intensity in a local or patchy distribution. Hepatitis C virus appears to replicate in HCC cells and the significance of such viral replication in hepatocarcinogenesis remains to be clarified.

Adolescent↗
PubMed1994

A pitfall in diagnosing a tumor thrombus by computed tomography.

This paper presents a case of right renal cell carcinoma with a false-positive finding of tumor thrombus in the inferior vena cava. The intraluminal filling defect revealed by computed tomography appeared to be an artifact due to the inflow of non-opacified blood into the inferior vena cava. The possibility of such an artifact should be borne in mind to avoid as far as possible any unnecessary diagnostic intervention and delay in instituting proper therapy.

Carcinoma, Renal Cell↗
PubMed1994

Neodymium:YAG laser ablation of the prostate gland--acute perioperative morbidity and short-term outcome.

Twenty-three patients with symptomatic bladder outlet obstruction due to benign prostatic hyperplasia were successfully treated with laser prostatectomy using the Urolase right-angle firing neodymium: Yttrium Aluminum Garnet laser fiber. Most of the patients had health problems of moderate severity. Their conditions were compared preoperatively and 3 mo postoperatively. Symptom scores decreased from an average of 23.9 to 7.0. Symptomatic relief was achieved in 95.7% of patients. Peak urinary flow rates increased from an average of 6.4 to 17.0 ml/s. The residual urine decreased from an average of 45.2 to 22.9 ml. The volume of the prostate gland measured by sonography decreased from an average of 32.8 to 25.7 ml. Virtually no blood loss was noted intraoperatively. Acute urinary retention occurred immediately following removal of the catheter in 3 out of 17 (17.6%) patients without a percutaneous cystostomy tube. Acute epididymitis developed in 5 out of 20 (25.0%) patients without bilateral vasectomy. Based on these results, laser prostatectomy may be concluded to be a safe and effective alternative to standard transurethral resection of the prostate gland, particularly in the case of high-risk patients.

Adenocarcinoma↗
PubMed1994

Pathology of livers infected with "silent" hepatitis B virus mutant.

We have discovered that non-A, non-B, non-C, non-D, non-E (so-called type F) acute and chronic hepatitis is caused by a hepatitis B virus (HBV) variant with mutations in the X open reading frame. This silent HBV mutant does not induce immunoserological markers. In the present investigation we attempted to elucidate the putative mechanism of hepatocellular necrosis and expression patterns of hepatitis B surface antigen (HBsAg) and core antigen (HBcAg) in biopsied liver tissue. The subjects consisted of 14 patients with acute hepatitis, 11 with chronic hepatitis and eight with liver cirrhosis, all of whom had been previously diagnosed as having so-called hepatitis F. Nine of the 14, 10 of the 11 and all eight, respectively, of the above patients exhibited significant positive immunostaining for HBsAg within their hepatocellular cytoplasm, diffusely or focally. HBcAg stained in a few hepatocellular nuclei in 24.2% of the patients. Histological features were characterized by necroinflammation, indicating immune-mediated hepatocellular necrosis. Despite the serological-marker negativity, the results of immunostaining for HBsAg and HBcAg support replication and expression of HBV DNA, though weak.

Acute Disease↗
PubMed1994

Age-dependent increase of neurotensin expression in the ileum.

The proliferative activity of gut mucosa is increased with aging. Neurotensin (NT), a tridecapeptide localized to the distal small bowel, stimulates growth of gut mucosa; the effects of aging on gut NT are not known. Young (4-mo-old), adult (1-yr-old), and aged (2-yr-old) male Fischer 344 rats were killed; the ileal mucosa was scraped, weighed, and extracted for measurement of NT mRNA by slot-blot and Northern hybridization; and the relative NT transcription rate was determined by a nuclear run-on assay. In addition, NT tissue content and plasma levels were determined by radioimmunoassay, and full-thickness sections of ileum were examined for age-dependent alterations of NT endocrine cell (N-cell) number using immunohistochemical staining. Slot-blot and Northern-blot analyses showed that the steady-state levels of NT mRNA were increased threefold in the adult group and eightfold in the aged rats. In addition, NT peptide content and plasma levels were significantly increased in the aged group. The dramatic increases in the abundance of NT mRNA were not associated with increases in either NT transcription or N-cell number. In summary, we have demonstrated an age-dependent increase in the constitutive levels of ileal NT mRNA that appears not to be due to concomitant increases in transcription, suggesting that NT mRNA is increased by mechanisms involving mainly a posttranscriptional process. In addition, we have shown corresponding increases in the levels of both tissue and plasma NT with aging, indicating that expression of NT does not remain the same throughout life but actually increases with aging in the rat.

Aging↗
PubMed1994

Effect of aging on neurotensin-stimulated growth of rat small intestine.

The proliferative activity of gut mucosa is altered with aging; the potential for the aged gut to respond to trophic stimuli is not known. The purpose of this study was to determine whether there are age-related differences in the effects of the trophic gut peptide neurotensin (NT) on the structure and function of small bowel mucosa. NT (300 micrograms/kg) or saline (control) was injected subcutaneously at 8-h intervals for 5 days in rats of two age groups, young (2 mo) and aged (24 mo). On day 6, rats were killed, and the gut mucosa (proximal and distal small bowel) was scraped, weighed, and analyzed for DNA, RNA, and protein content and for disaccharidase (sucrase and maltase) activity. In a second experiment, the groups of rats and the protocol for NT administration were identical; however, when the rats were killed, the distal gut was removed for histological evaluation of crypt and villus length (mm) and density (no./cm gut segment) and bromodeoxyuridine immunohistochemistry. NT produced significant increases in mucosal growth (wt, DNA, RNA, and protein) in both age groups when compared with age-matched controls; the increase of growth measurements was the greatest in the small bowel mucosa of the aged rats. In addition, NT increased crypt density in both groups; only the aged group treated with NT demonstrated increases in crypt depth and villus height. Specific activities of sucrase and maltase did not change with NT treatment in either of the age groups. We conclude that the proliferative potential of small bowel mucosa is maintained with aging in response to administration of NT.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1994

Cardiopulmonary bypass impairs vascular endothelial relaxation: effects of gaseous microemboli in dogs.

Gaseous microemboli during hypothermic cardiopulmonary bypass (CPB) may injure the vascular endothelium and interfere with intrinsic vasomotion. We tested whether gaseous microemboli reduced the vasodilator response to acetylcholine (ACh, 10(-9)-10(-6) M) and potentiated the vasoconstrictor response to norepinephrine (NE, 3 x 10(-8)-10(-4) M). Arteries from 18 dogs were excised before and after 120 min 28 degrees C CPB using membrane (n = 9) and bubble (n = 9) oxygenators to produce microemboli, which were quantitated by Doppler. Five nonbypassed dogs were controls. In isolated vessel rings, the 50% effective dose (ED50) values for ACh (10(-8) M) and NE (10(-7) M) responses were calculated. Mean microemboli count per minute was 0 +/- 0 in the control group, 1.0 +/- 0.4 in the membrane group (P < 0.05 vs. controls), and 46.9 +/- 8.4 in the bubble group (P < 0.05 vs. control and membrane groups). ACh ED50 values did not change in controls but increased in the membrane group from 4.01 +/- 1.52 to 5.66 +/- 1.39 (P < 0.05) and in the bubble group from 2.32 +/- 0.56 to 7.21 +/- 1.90 (P < 0.05). The change in ED50 was greater for bubble than for membrane animals (P < 0.05) but did not correlate with microemboli number (bubble: r = 0.392, P = 0.297; membrane: r = 0.058, P = 0.802). NE responses were similar in all groups. Hypothermic CPB reduces ACh-induced dilation of the canine femoral artery independent of the incidence of gaseous microemboli.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Pathology of hepatitis C.

Damage and necrosis of hepatocytes in viral hepatitis C is considered to be immune mediated as in hepatitis B. Hepatocellular necrosis accompanies infiltration of lymphocytes and this feature, called necroinflammation, characterizes all types of viral hepatitis and corresponds to the histological expression of hepatitis. Although the histological features of hepatitis C do not differ fundamentally from those of hepatitis B, there are some quantitative differences. Weak but constant necroinflammation and a strong lymphocytic reaction of the portal tracts appear to be relatively unique to chronic hepatitis C. Nearly all chronic hepatitis C cases do not improve during the natural course of infection; however, in a limited number of cases, interferon treatment can eliminate the virus leading to normalization. The pattern and extent of fibrosis can roughly predict the efficacy of interferon treatment.

Antigens, Viral↗
PubMed1994

Diuretic and vasodilating actions of torasemide.

The pharmacological profile of torasemide was examined in experimental animals. In normotensive Wistar rats, torasemide produced less kaliuresis at doses that were equipotent with furosemide in terms of natriuresis. Torasemide but not furosemide exerted a significant diuretic action in rats treated with deoxycorticosterone acetate. Both torasemide and furosemide increased plasma renin activity and aldosterone concentration, but only torasemide significantly inhibited aldosterone-receptor binding in rat kidney. Torasemide also inhibited vasoconstriction induced by thromboxane A2 in isolated canine coronary artery.

Aldosterone↗