Search PubMed⌕ Search

Biomedical subjects

N Watanabe

Publications and source records attributed to N Watanabe.

At least 811 records · Page 45Linked to original sources
PubMed1991

A novel recombinant tumor necrosis factor-alpha mutant with increased anti-tumor activity and lower toxicity.

We prepared a novel recombinant tumor necrosis factor-alpha (TNF) mutant (mutant 471), in which 7 N-terminal amino-acids were deleted and Pro8Ser9Asp10 was replaced by ArgLysArg, and compared its biological activity with that of wild-type recombinant TNF. Mutant 471 had a 7-fold higher anti-tumor activity against murine L-M cells in vitro, and a higher binding activity to TNF receptors on L-M cells, than wild-type TNF. Furthermore, mutant 471 showed a higher anti-tumor effect on murine Meth A-HM tumors transplanted into BALB/c mice, with complete regression of the tumors being observed in the animals. The possible cachectin activity of mutant 471 was almost the same as that of wild-type TNF. The acute lethal toxicity of mutant 471 in beta-D-galactosamine-sensitized C3H/HeJ mice was 18 times lower than that of wild-type TNF. These results suggest that mutant 471 might be a more promising anti-cancer agent than wild-type TNF.

Amino Acid Sequence↗
PubMed1991

Structures of regulatory regions in the human cytochrome P-450scc (desmolase) gene.

The mechanism of regulatory expression of human cytochrome P-450scc gene by cAMP was investigated in a transient expression system using Y-1 cells (mouse adrenal tumor cell line) and a chimeric DNA composed of the structural gene for bacterial chloramphenicol acetyltransferase and the 5' flanking upstream sequence of the cytochrome P-450scc (cholesterol desmolase) gene which was revealed to contain a DNA element(s) responsive to cAMP [Inoue, H. et al. (1988) Eur. J. Biochem. 171, 435-440]. Introduction of deletions and point mutations in the upstream regulatory sequence demonstrated that three regions were mainly required for response to cAMP. These regions contained a short similar sequence. All of them have a 5-bp motif GTCAT (or ATGAC) in common, and have at least two motifs which conserve four out of five base pairs of the consensus sequence of the cAMP-responsive element (CRE), CGTCA (or TGACG). They are all apparently necessary for regulation by cAMP. Gel mobility shift assays suggested that a binding factor(s) to these regions was present in the nuclear extracts of Y-1 cells and adrenal cortex tissues and appeared to be different from the somatostatin CRE-binding protein. Deletion analysis also suggested that the region around -44 was essential to the basal transcriptional activity. This region shows some similarity to the CTF NF-1 binding site [Johnson and McKnight (1989) Annu. Rev. Biochem. 58, 799-839].

Animals↗
PubMed1991

Effects of porcine galanin on the mesenteric microcirculation and arteriolar smooth muscle in the rat.

The actions of porcine galanin on the mesenteric circulation at the arteriolar level and on the isolated mesenteric small artery were studied in the rat. Male Wistar rats were anesthetized then laparotomized. Microscopic observation of the mesenteric microvascular area was made with a video camera and changes in arteriolar diameter were measured continuously with a width analyzer. Galanin (0.03-300 pmol), given intra-arterially into the mesenteric arteriole, caused an intermittent interruption of blood flow within 40 s and finally stopped the blood flow within a few minutes. The diameter of arterioles was not changed or was slightly widened. Galanin also relaxed the preconstricted small mesenteric artery in an endothelium-independent manner. Furthermore, the relaxing action of galanin was not antagonized by glibenclamide, indicating that activation of ATP-sensitive K+ channels was not involved. The present results suggest that galanin plays a modulatory role in the mesenteric circulation.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1991

Nucleolar organizer regions in precancerous and cancerous lesions of the bronchus.

Using a silver staining technique, nucleolar organizer region-associated proteins (Ag-NOR) were studied in paraffin sections of five specimens of normal bronchial epithelium, eight of atypical squamous metaplasia, five of carcinoma in situ, and seven of microinvasive squamous cell carcinoma. The mean number of Ag-NOR in the nucleus were normal epithelium 1.2 +/- 0.1 (mean +/- SD), atypical squamous metaplasia (borderline lesion) 2.2 +/- 0.5, carcinoma in situ 3.8 +/- 0.6, and microinvasive squamous cell carcinoma 4.8 +/- 1.1. There was a highly significant difference between the Ag-NOR numbers in the atypical squamous metaplasia and those in the carcinoma in situ (P less than 0.01). The Ag-NOR staining is a useful technique for the differential diagnosis of difficult borderline lesions in the bronchial epithelium.

Bronchial Neoplasms↗
PubMed1991

Oral vaccine therapy for pneumococcal otitis media in an animal model.

We investigated whether mucosal IgA response in the middle ear cavity against Streptococcus pneumoniae type 19F is enhanced by use of enteric capsules, and whether the resulting mucosal immunity can prevent pneumococcal otitis media. Adult Hartley guinea pigs were employed. With intratympanic inoculation of 10(5) and 10(6) live S pneumoniae, the occurrence of pneumococcal otitis media significantly decreased in guinea pigs that received intraduodenal and intragastric immunization by enteric capsules. In these guinea pigs, the values of salivary IgA antibody titers against S pneumoniae were significantly greater, and histologic changes of the middle ear mucosa were also slighter than those of control guinea pigs. These findings indicate that oral vaccination by enteric capsules elicits mucosal IgA responses, as well as intraduodenal immunization, to prevent pneumococcal otitis media. These results suggest the possibility of clinical application of oral vaccination by enteric capsules for the prevention of middle ear infection.

Administration, Oral↗
PubMed1991

High performance liquid chromatography of glucose using a post-column reactor of immobilized enzyme followed by electrochemical detection (glucose-LCEC).

A sensitive and selective, reasonably fast method for the determination of glucose content has been developed. A glucose oxidase immobilized column was coupled to a small-size anion exchange column/borate buffer chromatograph. The hydrogen peroxide produced in the enzyme reaction was detected directly by an amperometric detector using a platinum working electrode. The detection limit was 0.03 ppm (1.5 x 10(-7) M, 3 pmol/injection). The linear dynamic range was three orders of magnitude at least. The system was stable and reproducible both in short- and long-term operation. The proposed method is suitable for analysis of complicated matrices of biological samples because of its good selectivity and sensitivity.

Chromatography, High Pressure Liquid↗
PubMed1991

Successful treatment of a case of hepatocellular carcinoma with tumor necrosis factor and local hyperthermia.

A case of unresectable hepatocellular carcinoma which responded favorably to combined therapy with tumor necrosis factor (TNF) and local hyperthermia is reported. A 58-year-old man was admitted to our hospital in June 1988 for treatment of hepatocellular carcinoma affecting S4 and S8. After three sessions of transcatheter arterial embolization (TAE) therapy, the serum alpha 1-fetoprotein level decreased, and a reduction in the size of the lesions was also noted. Thereafter, the patient received local hyperthermia once a week (60 minutes of irradiation from a Thermotron-RF8 at 1,100W), but the alpha 1-fetoprotein level increased again in February 1989. On examination, enlargement of the S8 lesion and a new nodule in S7 were recognized. Since TAE was contraindicated due to liver dysfunction, human recombinant TNF (1 x 10(6)U) was given by intravenous infusion together with local hyperthermia once a week. Eight sessions of the combined therapy reduced the serum alpha 1-fetoprotein level markedly (7,512.0 to 2,782.0 pg/ml) and after eighteen sessions, 58.1% regression of tumor size (partial response) on computed tomography scans was observed. This anecdotal case supports previous experimental evidence suggesting that TNF plus hyperthermia may be effective for treating unresectable hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed1991

Aortic valve replacement with omniscience and omnicarbon valves.

Clinical results achieved in 100 cases of aortic valve replacement with the Omniscience (O-S) valve during the period from 1980 to 1985 as well as 100 cases of aortic valve replacement with the Omnicarbon (O-C) valve during the period from 1985 to 1989 were studied. Concomitant surgical procedures including mitral valve replacement were performed in 63 patients in the O-S group and 67 patients in the O-C group. Cumulative follow-up in the two groups was carried out for a total of 559 and 273 patient-years, respectively. The overall 4-year actuarial survival rate was 82% +/- 3.8% in the O-S group and 89.5% +/- 3.2% in the O-C group, the corresponding rates for patients undergoing isolated aortic valve replacement being 82.9% +/- 4.2% in the O-S group and 91.9% +/- 3.5% in the O-C group. The overall 4-year actuarial event-free rate with respect to thromboembolic complications was 88.8% +/- 3.3% in the O-S group and 94.4% +/- 2.8% in the O-C group, as compared with the corresponding rates of 89.2% +/- 3.6% in the O-S group and 95.9% +/- 2.8% in the O-C group for patients undergoing isolated aortic valve replacement. The overall rate of valve-related complications, including thromboembolism, anticoagulant-related hemorrhage, perivalvular leak, infection, and structural failure, was 78.8% +/- 4.2% in the O-S group and 89.3% +/- 3.5% in the O-C group (p less than 0.05), and for isolated aortic valve replacement, 79.7% +/- 4.5% in the O-S group and 89.6% +/- 4.1% in the O-C group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Congenital middle ear cholesteatoma: report of 3 cases.

In this report, we presented 3 cases of congenital middle ear cholesteatoma which occurred in a 12-year-old girl, a 4-year-old boy, and a 6-year-old boy. In all 3 cases, there was a whitish mass behind a normal tympanic membrane. Congenital middle ear cholesteatoma is not a rare disease. In the early stage, it is asymptomatic. But when it progresses, this disorder can destroy conductive systems of the middle ear and cause many symptoms. One patient (Case 1) had a complaint of hearing impairment. She underwent mastoidectomy and tympanoplasty; however, the cholesteatoma recurred. The other 2 patients had no symptoms. The abnormal appearance of their tympanic membrane was found by chance at their local otologists. We performed tympanotomies and removed cholesteatomas without aftereffects. When otologists note an abnormal appearance behind a normal tympanic membrane, with or without symptoms, tympanotomy should be done due to the possibility of congenital middle ear cholesteatoma.

Audiometry↗
PubMed1991

Motility of bile canaliculi in the living animal: implications for bile flow.

Modern fluorescence microscopic techniques were used to image the bile canalicular system in the intact rat liver, in vivo. By combining the use of sodium fluorescein secretion into bile, with digitally enhanced fluorescence microscopy and time-lapse video, it was possible to capture and record the canalicular motility events that accompany the secretion of bile in life. Active bile canalicular contractions were found predominantly in zone 1 (periportal) hepatocytes of the liver. The contractile movements were repetitive, forceful, and appeared unidirectional moving bile in a direction towards the portal bile ducts. Contractions were not seen in the network of canaliculi on the surface of the liver. Cytochalasin B administration resulted in reduced canalicular motility, progressive dilation of zone 1 canaliculi, and impairment of bile flow. Canalicular dilations invariably involved the branch points of the canalicular network. The findings add substantively to previous in vitro studies using couplets, and suggest that canalicular contractions contribute physiologically to bile flow in the liver.

Animals↗
PubMed1991

Human tumor-infiltrating lymphocytes transfected with tumor necrosis factor gene could augment cytotoxicity to autologous tumor cells.

Human tumor-infiltrating lymphocytes (TILs) derived from pleural or ascitic fluid were incubated with recombinant interleukin 2 and transfected with human tumor necrosis factor (TNF) alpha gene by the lipofection procedure. The resulting TILs secreted significant amounts of TNF in the culture supernatant and exhibited cytotoxicity against established cell lines, such as K562 and Daudi, and autologous tumor cells. The TNF gene-transfected TILs exhibited an augmented killing of autologous tumor cells.

Ascites↗
PubMed1991

Platelet aggregation induced by adenosine diphosphate released from cloned murine fibrosarcoma cells is positively correlated with the experimental metastatic potential of the cells.

We established five clones (ML-01, ML-02, MH-01, MH-02, MH-03) from murine 3-methylcholanthrene-induced fibrosarcoma A (Meth A), and investigated their experimental metastatic potentials in relation to their platelet-aggregating activities. A clone with a high metastatic potential (MH-02) showed a characteristic biphasic pattern of platelet aggregation, of which the first peak was not present in the aggregation patterns of the clone with low metastatic potential (ML-01). The first peak was eliminated by treatment of the cells with apyrase, indicating that adenosine diphosphate (ADP) was the causative substance of this particular peak. The metastatic potential of clones correlated well with the ADP concentration of the culture media. These results suggest that the increased ADP production and consequential enhancement of platelet-aggregating activity are closely related to the increment of pulmonary metastatic potential of MH-02 clone.

Animals↗
PubMed1991

Correlation between physiological and transforming activities of the c-mos proto-oncogene product and identification of an essential Mos domain for these activities.

Using Xenopus eggs and NIH3T3 cells as assay systems, we have compared the physiological (i.e., maturation-inducing and cleavage-arresting) and in vitro transforming activities of the c-mos genes from various species as well as their mutant genes. These analyses show that the three biological activities all depend upon the intrinsic protein kinase activity of Mos and correlate well with each other. Furthermore, our results demonstrate that a well conserved N-terminal 14-amino acid sequence of Mos, termed the Mos-box, is essential for all three activities. These results indicate that the in vitro transforming activity of Mos can be ascribed to the same kinase activity of Mos that exerts the physiological activities.

Amino Acid Sequence↗
PubMed1991

T cell-mediated inhibition of erythropoiesis in aplastic anaemia: the possible role of IFN-gamma and TNF-alpha.

The inhibitory activity of T cells on autologous erythroid colony-forming units (CFU-E) (T cell inhibitory activity) in patients with aplastic anaemia (AA) was investigated. In 11 (32.4%) out of 34 AA cases, T cell inhibition on autologous CFU-E growth was greater than that in normal individuals. In order to evaluate the mechanism of this inhibitory activity, T cell surface markers, interferon (IFN) production in peripheral blood mononuclear cell (PBMNC) liquid culture, and cytokine levels such as IFN and tumour necrosis factor-alpha (TNF-alpha) in CFU-E clot cocultured with T cells, were measured in a portion of the patients. In five patients investigated for IFN production in PBMNC liquid culture, all produced statistically more IFN activity than normal individuals under phytohaemagglutinin (PHA-P) stimulation (P less than 0.01) with no relation to T cell inhibitory activity. In only one patient whose T cells displayed increased CD8 and HLA-DR antigen (CD8+HLA-DR+) and inhibitory activity, a significant amount of IFN-gamma was observed in CFU-E clot cocultured with T cells, and the addition of anti-IFN-gamma antibody to the coculture resulted in recovered CFU-E colony growth. These results suggest that IFN-gamma production by T cells may explain, at least in part, the pathogenesis of haematopoietic defects in AA. In other patients however, T cell inhibitory activity neither correlated to the T cell subpopulations (CD4+/CD8+, CD8+HLA-DR+), IFN production in PBMNC liquid culture, nor to IFN and TNF-alpha levels in CFU-E clot culture. The roles played by cytokines other than IFN and TNF-alpha on haematopoietic precursor cells require further evaluation in a larger sample of patients with AA.

Adolescent↗
PubMed1991

Cytomegalovirus DNA in the sera of patients with cytomegalovirus pneumonia.

We attempted to detect cytomegalovirus DNA (CMV-DNA) in the sera of four leukaemia patients who underwent an allogeneic bone marrow transplant (BMT), in six leukaemia patients who suffered from pneumonia and in 16 healthy subjects, using the polymerase chain reaction (PCR). Three of the four BMT patients subsequently developed CMV pneumonia. In two cases, CMV-DNA was detected in the sera at about the time the pneumonia occurred, and the amount of DNA increased with disease progression. The serum of the third patient became positive for CMV-DNA before he developed pneumonia. The fourth patient did not develop CMV pneumonia, but his urine became persistently positive for CMV-DNA soon after the BMT, whereas the serum was negative. A relationship was found between the occurrence of pneumonia and the serum level of CMV-DNA. CMV-DNA was also detected in three of six pneumonia patients whose anti-CMV IgM antibodies were elevated in the circulation. Sera from the 16 normal subjects were negative for CMV-DNA, regardless of their being seropositive or seronegative for CMV. While it had been previously thought that CMV did not exist in serum, we detected CMV-DNA in serum by PCR in the active disease stage. Our results suggest that PCR would be useful for the early diagnosis of CMV pneumonia and in monitoring its course.

Adolescent↗
PubMed1991

A clinical study of upper gastrointestinal endoscopy in Japanese children.

A total of 370 children who underwent upper gastrointestinal endoscopy (534 procedures) were retrospectively studied. All procedures were performed successfully. Side effects were demonstrated in only one case (0.2%), which was complicated by perioral cyanosis during the procedure. As to pre-endoscopic medication, it was thought that topical pharyngeal anesthesia alone may well be used for school-age children over 7 years of age, general anesthesia with endotracheal intubation for neonates, and intravenous sedation for infants and younger children. Of 370 patients studied, 70.8% had endoscopic diagnoses. The most common diagnosis was gastritis (136 cases), followed by peptic ulcer (75), duodenitis (29), and esophagitis (20). Several conclusions for indications were drawn from the present study. Pediatric upper gastrointestinal endoscopy is a safe and useful method for diagnostic and therapeutic approach, if adequate pre-endoscopic medication is chosen.

Adolescent↗
PubMed1991

Conversion of Friend mink cell focus-forming virus to Friend spleen focus-forming virus by modification of the 3' half of the env gene.

The 3' half of the env gene of the dualtropic Friend mink cell focus-forming virus was modified by replacing the restriction enzyme fragment of the genome DNA with the corresponding fragment of the acutely leukemogenic, polycythemia-inducing strain of Friend spleen focus-forming virus (F-SFFVP) genome DNA. Replacement with the fragment of F-SFFVP env containing the 585-bp deletion, the 6-bp duplication, and the single-base insertion converted the resulting chimeric genome so that the mutant had a pathogenic activity like that of F-SFFVP. Replacement with the fragment containing only the 585-bp deletion did not result in a pathogenic virus. However, when this virus pseudotyped by Friend murine leukemia virus was passaged in newborn DBA/2 mice, we could recover weakly pathogenic viruses with a high frequency. Molecular analysis of the genome of the recovered virus revealed the presence of a single-base insertion in the same T5 stretch where the wild-type F-SFFV env has the single-base insertion. These results provided evidence that the unique genomic structures present in the 3' half of F-SFFV env are the sole determinants that distinguish the pathogenicity of F-SFFV from that of Friend mink cell focus-forming virus. The importance of the dualtropic env-specific sequence present in the 5' half of F-SFFV env for the pathogenic activity was evaluated by constructing a mutant F-SFFV genome in which this sequence was replaced by the ecotropic env sequence of Friend murine leukemia virus and by examining its pathogenicity. The results indicated that the dualtropic env-specific sequence was essential to pathogenic activity.

Animals↗