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N Masuda

Publications and source records attributed to N Masuda.

At least 199 records · Page 11Linked to original sources
PubMed1987

Construction of a new plasmid vector that can express cloned cDNA in all translational reading frames.

Construction of a bacterial expression vector, pSI4001, is described. The vector contains the lac promoter-operator and three sets of ribosome-binding sites (RBSs) tandemly arranged in all possible reading frames. cDNA can be directly cloned downstream from these translational start points in the fixed and proper orientation by using the method of Okayama and Berg [Mol. Cell. Biol. 3 (1982) 280-289]. The open reading frame of any cDNA inserted may be automatically aligned in phase with either of the three ATG start codons, thus enabling its expression with a maximum theoretical probability of unity. Fusion with the lacZ gene (coding for beta-galactosidase) has shown that at least two of the three translation initiation sites exhibit high expression capacities and the remaining one can also function at a lower but significant rate. We used the vector to construct a bovine pituitary cDNA library, from which clones coding for prolactin were detected by immunological screening with an efficiency as high as two in three clones. The construction with triple RBSs should also provide a unique experimental model to study the regulation of overlapping translations.

Animals↗
PubMed1987

[Carcinoma of the urachus with variable pathological findings: report of a case and review of literature].

A 71-year-old man was admitted with the chief complaint of gross hematuria. Cystoscopic examination showed a broadbased papillary tumor at the apex of the bladder. There was edema of the mucous membrane around the tumor. CT-scan demonstrated a mass extending from the bladder dome superiorly. Partial resection of the bladder was done. Pathological examination revealed grade 3 transitional cell carcinoma, with scattered adenocarcinoma and squamous cell carcinoma foci. Chemotherapy with bleomycin (BLM) and cis-dichlorodiamine platinum (CDDP) was done postoperatively. Ten months after the operation, he was readmitted because of recurrence in retroperitoneal lymph nodes. Chemotherapy with BLM and CDDP was done, but he died of pulmonary complications. Autopsy revealed retroperitoneal lymph node metastasis of transitional cell carcinoma. There was no metastasis to any other organ. We briefly discuss 275 cases of the carcinoma of the urachus collected from the Japanese literature.

Adenocarcinoma↗
PubMed1987

[Serial measurements of serum carcinoembryonic antigen (CEA) and neuron-specific enolase (NSE) during chemotherapy of patients with inoperable lung cancer].

Serial measurements of serum CEA levels were analyzed in 226 patients with inoperable lung cancer (115 small cell carcinomas, 64 adenocarcinomas, 37 squamous cell carcinomas and 10 large cell carcinomas) during chemotherapy. Of all patients, 29.1% had pretreatment CEA levels greater than or equal to 5 ng/ml. In all of the patients with complete response, and 15 (68.2%) of 22 patients with partial response whose pretreatment CEA levels were 5 ng/ml or higher, CEA levels fell to below 5 ng/ml. All of 17 patients who showed a decrease greater than 50% in serum CEA levels during chemotherapy showed a shrinkage of more than 50% in the tumor burden. Serial serum CEA level measurements were useful as an indicator of response to chemotherapy in advanced lung cancer. Serial serum NSE levels were measured in 36 patients with small cell lung cancer. Pretreatment NSE levels were elevated to more than 10 ng/ml in 83.1% of all patients. A transient rise in serum NSE levels occurred in 22 out of 33 patients measured on the third day during initial chemotherapy. Serum NSE levels greater than or equal to 10 ng/ml declined to within the normal range in all patients responding to the chemotherapy. The survival in patients whose NSE levels (greater than or equal to 10 ng/ml) fell to within the normal range for more than four weeks was longer than that in other patients. Serial measurements of serum NSE levels were thus useful for monitoring the response to chemotherapy in cases of small cell lung cancer.

Adenocarcinoma↗
PubMed1985

Transmission of Streptococcus mutans in some selected families.

The aim of the present study was to determine the source and transmission route of Streptococcus mutans. The frequency of this organism in saliva and plaque samples was compared among fifteen pairs of mothers and their children. The results showed that most of the mothers harboured almost equal or greater levels of S. mutans than their children. Similarities of the distribution of various serotypes and mutacin types were observed between these mothers and their offspring. Samples were also collected from plaque and/or carious lesions of the relatives of the subjects who carried one of the serotypes other than serotype c as the dominant S. mutans. The strains of the same serotypes of S. mutans which possessed similar mutacin patterns were predominantly detected in the siblings and mothers of each subject. However, a similar distribution of S. mutans strains was not clearly observed in other relatives including fathers, aunts, uncles and grandparents.

Adult↗
PubMed1984

7 alpha-Dehydroxylation of bile acids by resting cells of a Eubacterium lentum-like intestinal anaerobe, strain c-25.

7 alpha-Dehydroxylation of cholic acid and chenodeoxycholic acid by whole cells of strain c-25, a Eubacterium lentum-like intestinal anaerobe, was studied. 7 alpha-Dehydroxylase activity was observed only in whole cells grown in the presence of the primary bile acid (cholic acid or chenodeoxycholic acid). Chenodeoxycholic acid was twice as effective as cholic acid as an inducer. Although cells grown in the presence of chenodeoxycholic acid had no significant substrate specificity for the two primary bile acids, cells grown in the presence of cholic acid showed two times greater activity against cholic acid than chenodeoxycholic acid. Exposure of cell suspensions to atmospheric oxygen resulted in little loss of the 7 alpha-dehydroxylase activity. The induced enzyme had an optimal pH range of 7.3 to 7.7. Although adding flavin mononucleotide to the growth medium significantly increased the 7 alpha-dehydroxylation of bile acids without an increase in cell growth, inhibition of the enzyme activity was observed in the resting cell system when flavin mononucleotide was included in the reaction mixture.

Animals↗
PubMed1984

Clinical isolates of Streptococcus mutans serotype c with altered colony morphology due to fructan synthesis.

Streptococcus mutans MT6801 , MT6861 , and MT6879 , which form large mucoid colonies on mitis salivarius agar, were isolated from a mother and her two daughters. These isolates were identified as serotype c by immunodiffusion with serotype-specific antisera. The large colonies formed on sucrose-containing agar were found to contain water-soluble fructan . The cell-free fructosyltransferase ( FTase ) activity of the strains which formed large colonies was five to eight times higher than that of serotype c S. mutans which produced small, rough colonies typical of this serotype. Furthermore, greater quantities of fructan were synthesized from sucrose by growing cells of MT6801 when compared with MT8148 , a typical serotype c S. mutans. Glucosyltransferase and FTase could be isolated by chromatofocusing from culture supernatants of MT6801 and MT8148 . The FTase activity of both strains was eluted at pH 4.5, and glucosyltransferase was released by elution with an NaCl linear gradient. The eluted FTase activity of MT6801 was significantly higher than that of MT8148 . Strains MT6861 and MT6879 were also found to possess a similar property in terms of FTase activity. These results suggest that formation of large mucoid colonies by these strains is a consequence of high FTase activity.

Adult↗
PubMed1984

Salivary excretion of urea in dogs.

The salivary excretion of urea was investigated by collecting parotid saliva (Pr) and mandibular-sublingual saliva (MS) separately in beagle dogs. (1) After intravenous administration of urea (1.5 g/kg), urea concentrations in both Pr and MS were well correlated to but were lower than those in plasma. Urea concentrations in MS were significantly lower than those in Pr (p less than 0.05), indicating that there was glandular difference in salivary excretion of urea. (2) This glandular difference was not explained by Matin's equation, even if all variation factors in this equation were considered. (3) At relatively low salivary flow rates, the increase in saliva/plasma urea concentration ratio (S/P ratio) for both Pr and MS was found in the experiments for endogenous urea. (4) At relatively low salivary flow rates, glandular difference was observed in the S/P ratios of sodium ion. (5) Salivary clearance of urea was highly dependent on salivary flow rate under stimulated condition for salivation, and mean value of the salivary clearance of urea was about 20% of its total body clearance.

Absorption↗
PubMed1983

Purification and characterization of NADP-dependent 7 beta-hydroxysteroid dehydrogenase from Peptostreptococcus productus strain b-52.

An NADP-dependent 7 beta-hydroxysteroid dehydrogenase was purified 11.5-fold over the activity in crude cell extracts prepared from Peptostreptococcus productus strain b-52, by using Sephadex G-200 and DEAE-cellulose column chromatography. 7 beta-Dehydrogenation was the sole transformation of bile acids catalyzed by the partially purified enzyme. The enzyme preparation (spec. act. 2.781 IU per mg protein) had an optimum pH of 9.8. Lineweaver-Burk plots showed a Michaelis constant (Km) value of 0.05 mM for 3 alpha, 7 beta-dihydroxy-5 beta-cholanoic acid whereas higher values were obtained with 3 alpha,7 beta-dihydroxy-5 beta-cholanoyl glycine (0.20 mM), and 3 alpha,7 beta-dihydroxy-5 beta-cholanoyl taurine (0.26 mM). NADP but not NAD could function as an electron acceptor, and had a Km value of 0.30 mM. A molecular weight of 64000 was determined by SDS-polyacrylamide gel electrophoresis. The addition of 0.4 mM of either bile acid to the growth medium suppressed not only cell growth, but also the enzyme yield.

Hydrogen-Ion Concentration↗
PubMed1983

Quantitative aspects of the receptor binding of cytokinin agonists and antagonists.

Congeneric 4-anilino- and 4-(alkylamino)-2-methylpyrrolo[2,3-d]pyrimidines showed cytokinin and anticytokinin activities, depending on the structure of their 4-substituents, and the antagonistic nature of the latter was established kinetically. The effect of the substituent on these activities was analyzed quantitatively by using physicochemical parameters and regression analysis to give a single, common equation for both the agonists and antagonists. The results indicated that the maximum width of the N4 substituents is an important factor both for binding to the receptor, thus the extent of activity, and for the quality of activity, agonistic or antagonistic. The electron-withdrawing effect and hydrophobicity of the substituents further enhance binding and, thus, activity, irrespective of the quality of the activity. These results coincide with and/or provide evidence for the hypothesis that in hormonal action, agonist binding causes a conformational change of an otherwise inactive receptor to the active form and that antagonists are species that bind similarly to the receptor but do not cause the effective conformational change.

Arabidopsis Proteins↗