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T Ueki

Publications and source records attributed to T Ueki.

At least 145 records · Page 8Linked to original sources
PubMed1991

[Carcinoma of the gastric remnant fed by the accessory left gastric artery--a case report].

A 65-year-old female, who had undergone partial gastrectomy with Billroth II reconstruction for duodenal ulcer 22 years ago, visited our hospital with a complaint of anorexia. Roentgenogram and endoscopic examination revealed a protruding lesion on the posterior wall of the gastric remnant. An endoscopic biopsy specimen was histologically regarded as carcinoma. Proper hepatic arteriography revealed an accessory left gastric artery arising from the left hepatic artery, which was a main feeder to the tumor. Total gastrectomy with lymph node dissection and splenectomy were performed. Histology of the tumor was poorly differentiated adenocarcinoma located in the submucosal layer. To our knowledge, there is no report about the carcinoma of the gastric remnant fed by the accessory left gastric artery.

Adenocarcinoma↗
PubMed1990

Dynamic mechanism of the self-assembly process of tobacco mosaic virus protein studied by rapid temperature-jump small-angle X-ray scattering using synchrotron radiation.

The self-assembly process of tobacco mosaic virus protein (TMVP) was observed by rapid temperature-jump time-resolved solution X-ray small-angle scattering using synchrotron radiation. The temperature-jump device used for the X-ray measurements is rapid enough to cope with even the fastest-assembling process of TMVP, and accumulates data of reasonable signal-to-noise ratios with a minimum total counting time of 7.5 seconds. The measurements suggested that the 20 S disk of TMVP polymerized to stacked disks (short rods). The time to complete stacking varied from approximately 25 seconds to approximately 1200 seconds, depending on the solution condition and magnitude of the temperature gap. Higher protein concentration, ionic strength and temperature favoured faster association. The results were analysed in terms of a set of kinetic equations that describe the two-stage aggregation of TMVP with an equilibrium constant K1, and two rate constants k+2 and k-2 for association and dissociation of disks, respectively. The consistency of the analysis suggests that the TMVP assembly proceeds in two steps of: (1) the aggregation of A-proteins into double-layered disks; and (2) the stacking of double-layered disks. The kinetic analysis indicated that the stacking belongs to the lowest range of protein-protein interaction system.

Capsid Proteins↗
PubMed1990

Usefulness and limitations of methotrexate, vinblastine, doxorubicin and cisplatin for the treatment of advanced urothelial cancer.

Methotrexate, vinblastine, doxorubicin and cisplatin were used to treat 66 patients with advanced urothelial cancer. Of these 66 patients 58 could be evaluated for response. A total of 84 sites was evaluated in these patients. Response rates were 73% in the bladder, 67% in the renal pelvis, 50% in the ureter, 60% in the lung, 68% in the lymph nodes, 14% in the liver and 25% in the bone. Ten patients (17%) had a complete response and 23 (40%) had a partial response, with an over-all response rate of 57% (the 95% confidence limits are 44 to 69%). The mean durations of response were 10.1 months for complete response patients and 6.2 months for partial response patients. The most prominent toxicity was severe myelosuppression that resulted in 2 septic deaths. While this chemotherapy regimen provided an excellent over-all response rate, the matters of concern were the short duration of response and low effectiveness in the liver and bone.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Structural change of troponin C molecule and its domains upon Ca2+ binding in the presence of Mg2+ ions measured by a solution X-ray scattering technique.

A small-angle X-ray scattering study on troponin C showed that two domains of the molecule move closer to each other and the molecule shrinks along its long axis upon Ca2+ binding in the absence of Mg2+ ions (Fujisawa, T., Ueki, T., & Iida S. (1988) J. Biochem. 105, 377-383). When Mg2+ ions bind to troponin-C, the radius of gyration changes from 27.8 to 24.3 A and the average radius of gyration of the two domains is estimated to be 15.1 A. These radii indicate that the distance between the centers of the two domains is 38.1 A. Such a change is analogous to the previous result for troponin C with two Ca2+ ions bound at the high-affinity sites. Thus, the structural behavior of troponin C molecule is essentially the same when Ca2+/Mg2+ ions bind to its high-affinity sites. On the other hand, the effect of Ca2+ binding to the low-affinity sites in the presence of Mg2+ ions is quite different from the previous result. The binding of Ca2+ ions causes a dimerization of troponin C molecules with an apparent constant of 511 M-1. Such a characteristic behavior, implying the occurrence of a surface property change, may be related to the physiological role of troponin C molecule in the muscle. The scattering experiments on the tryptic fragments of troponin C also had interesting and important results: the C-domain shrinks, with the radius of gyration changing from 17.0 to 14.9 A while the N-domain swells from 13.9 to 15.0 A upon Ca2+ binding. Such an opposite change is consistent with the results of circular dichroism and spectroscopic studies of the domains.

Binding Sites↗
PubMed1990

Isolation of a possible archetypal JC virus DNA sequence from nonimmunocompromised individuals.

We molecularly cloned JC polyomavirus DNAs from urine samples of eight nonimmunosuppressed patients and two healthy individuals. The cloned viral DNAs all contained an archetypal regulatory sequence from which various regulatory sequences of JC polyomavirus isolates derived from patients with progressive multifocal leukoencephalopathy could have evolved by deletion and amplification.

Base Sequence↗
PubMed1990

[In situ hybridization study of human papillomavirus from the penile cancer].

The histochemical detection of human papillomavirus (HPV) was performed using the technique of in situ hybridization from the formalin fixed paraffin embedded specimens of penile carcinoma and condylomata+ acuminata . One of 19 penile cancer cases (5.3%) revealed the positive staining on the nuclei of the tumors for HPV type 16/18. However, the positive nuclei were scattered and localized in small part of the tumor which showed no koilocytosis. On the contrary, 11 of 12 condyloma acuminata cases (91.7%) showed positive staining on the nuclei of the tumors for HPV type 6/11, also 5 of the 11 cases (45.5%) revealed cross reaction for other type of HPV. The HPV types 6/11, 16/18 and 31/33/35 may be unrelated to the pathogenesis of the Japanese penile carcinoma. However, further study is necessary to evaluate that the number of HPV-DNA copy in our cases is too small, or the other type of HPV is responsibility.

Adult↗
PubMed1989

Calcium-induced shape change of calmodulin with mastoparan studied by solution X-ray scattering.

Solution x-ray scattering using synchrotron radiation as an x-ray source was used to analyze the Ca2+-dependent shape change of pig brain calmodulin in detail. The radius of gyration of calmodulin at 10 mg/ml was increased by 0.9 A. The increase was nearly completed when 2.5 mol of Ca2+/mol of calmodulin was added, whereas the radius of gyration of calmodulin with mastoparan decreased by about 3 A with an increasing Ca2+ concentration up to 4 mol of Ca2+/mol of calmodulin. At a moderate angle of region, both scattering profiles from calmodulin with or without Ca2+ displayed clear humps at s = 0.03 A-1 which are characteristic of a dumbbell structure. However, in the presence of mastoparan, the hump in the scattering profile became obscure and later disappeared with the third and fourth Ca2+ binding to calmodulin. These findings are attributable to the Ca2+-induced shape change of calmodulin with mastoparan from a dumbbell structure to a non-dumbbell structure in which the distance between the two lobes of calmodulin become closer by a bend in the central helix.

Animals↗
PubMed1989

Circular dichroic study of conformational changes in ovalbumin.

By simulation of the circular dichroic spectra (Greenfield and Fasman (1969] and using reference spectra of Chen et al. (1974), native ovalbumin was estimated to contain 33% alpha-helix, 5% beta-structure, and 62% random coil. Ovalbumin resisted conformational changes in solutions of urea and of SDS. However, guanidine induced transition, starting at about 2 M and completing at about 4.5 M. At concentrations exceeding 4.5 M guanidine, ovalbumin existed as 6-7% alpha-helical, 12-13% beta-structure, and 80-81% random coil. Ovalbumin after denaturation in 6 M guanidine or in 8 M urea (incubated at 4 degrees C for 24 hr) did not recover the native conformation but acquired a new conformation in each case, with a somewhat destabilized helical structure.

Circular Dichroism↗
PubMed1989

Circular dichroic study of conformational changes in ovalbumin induced by modification of sulfhydryl groups and disulfide reduction.

Sulfhydryl groups of ovalbumin were chemically modified under denaturing conditions in the absence and presence of dithiothreitol, and effects on the secondary structure of the protein were investigated by circular dichroic (CD) measurements. The contents of alpha-helix, beta-structure, and "random coil" (unordered, nonrepetitive structure) were estimated by simulation of the CD spectra and using the parameters established by Chen et al. The principal findings were these: (1) Modification of the four free sulfhydryl groups [with 5,5'-dithiobis(2-nitrobenzoic acid), iodoacetate, or iodoacetamide] caused ovalbumin molecule to unfold partially and to undergo primarily helix-to-beta structure transition. (2) Cleavage of the disulfide bond did not lead to a further conformational change in the sulfhydryl-modified ovalbumin. (3) The remaining helical structure existed in a destabilized state with increased chain flexibility, as the modified protein was very susceptible to denaturation by guanidine and urea. (4) Further evidence for increased chain flexibility was provided by the finding that sodium dodecyl sulfate (SDS) induced helix formation in the sulfhydryl-modified, but not native, ovalbumin. And (5), since both nonreduced and reduced proteins, with their sulfhydryl groups blocked, displayed similar transitions in solutions of guanidine, urea, and SDS suggested that the single disulfide bond did not physically constrain the ovalbumin molecule.

Circular Dichroism↗
PubMed1989

Circular dichroic study of the conformational stability of sulfhydryl-blocked bovine serum albumin.

1. The blockage of the single sulfhydryl-group of bovine serum albumin does not alter the secondary structure, although the alpha-helical structure is destabilized since lower concentrations of guanidine and of urea unfold the protein. 2. What happens to the previously helical structure depends upon the reagent used to block the sulfhydryl-group. Bovine serum albumin derivatized with 5,5'-dithiobis-(2-nitrobenzoic acid) and iodoacetate preferentially acquire the beta-structure in high concentrations of guanidine and urea, whereas iodoacetamide-derivatized bovine serum albumin acquires primarily the random coil structure. 3. Part of the helical structure is also lost in 5-6 mM sodium dodecyl sulfate; thionitrobenzoate-bovine serum albumin shows an increase in the random coil, whereas the two alkylated proteins display the increase both in beta-structure and random coil. 4. Carboxymethylation or carboxamidomethylation of fully reduced bovine serum albumin results in a drastic change in the secondary structure of the protein with a substantial decrease in alpha-helix and a corresponding increase in both beta-structure and random coil. These extensively alkylated proteins also display differences in denaturation profiles in solutions of guanidine and urea.

Alkylation↗
PubMed1989

Structural change of the troponin C molecule upon Ca2+ binding measured in solution by the X-ray scattering technique.

The small-angle X-ray scattering technique was used to characterize the overall structural change as well as the state of aggregation of troponin C upon binding various amount of Ca2+ ions: in the Ca2+-free state and at pCa 6.5 and 4.0. Under these conditions, the forward scattering intensities of troponin C are not much different from each other: i.e., they coincide within 4%. From these intensities, the Ca2+-facilitated dimerization of troponin C was not verified, and no appreciable aggregation of troponin C molecules was detected below pCa 4.0. Thus, the small-angle X-ray scattering profiles from troponin C solutions were analyzed assuming a monomeric molecule. The radii of gyration of troponin C were 27.8 +/- 0.3 A, 23.8 +/- 0.2 A, and 22.6 +/- 0.1 A for the Ca2+-free state and at pCa 6.5 and 4.0, respectively. The maximum dimension of the molecule decreases from 111 to 98 A with increasing Ca2+ concentration. These results indicate that the troponin C molecule shrinks remarkably as Ca2+ ions bind to the high affinity sites of the molecule. Ca2+ binding to the low affinity sites, on the other hand, leads to a less pronounced change. Following the interpretation of scattering from the dumbbell-shaped structure (Fujisawa, T., Ueki, T., Inoko, Y., & Kataoka, M. [1987] J. Appl. Cryst. 20, 349-355), the two domains of the molecule move closer to each other. The distance between the centers of the two domains decreases from 46 to 35 A.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Binding of both Ca2+ and mastoparan to calmodulin induces a large change in the tertiary structure.

The technique of small-angle X-ray scattering has been employed to examine the solution conformation of calmodulin and its complexes with Ca2+ alone, and with both Ca2+ and mastoparan. The radius of gyration decreased by 3.1 +/- 0.3 A upon binding of both 4 mol Ca2+/mol of protein and 1 mol mastoparan/mol of protein to form the ternary complex. A smaller increase was found for the separate binding of 4 mol Ca2+/mol of protein in the absence of mastoparan (0.6 +/- 0.3 A). The analyses of pair distance distribution function showed that the maximal pair distance in calmodulin complex with both Ca2+ and mastoparan decreased by 20-30% in comparison with calmodulin or its complex with Ca2+, and a shoulder near 40 A, which characterizes the dumbbell-shaped molecule of calmodulin, disappeared. These results indicate that the two globular domains of the calmodulin complex with Ca2+ and mastoparan come close together by 8.0-9.5 A on average, if the size and the overall shape of the globular domains are the same in Ca2+-calmodulin-mastoparan complex as in calmodulin or Ca2+-calmodulin complex.

Animals↗
PubMed1989

Synchrotron X-ray scattering study of chromatin condensation induced by monovalent salt: analysis of the small-angle scattering data.

Small-angle X-ray scattering experiments were carried out on rat thymus chromatin in "native" and "H1-depleted" states at various NaCl concentrations using synchrotron radiation. From the analysis of cross-sectional Guinier plots, the radius of gyration of the cross section (Rc) and the mass per unit length (Mc) of native chromatin were evaluated. In the absence of NaCl, the cross section of chromatin filament has a radius of gyration of 3.44 nm, suggesting the structure corresponding to the "10 nm" filament. With increasing NaCl concentration, the Rc value increases steeply to 6.74 nm at 5 mM NaCl and then gradually to 8.82 nm at 50 mM NaCl, whereas the Mc value, which is determined relative to that of tobacco mosaic virus (TMV), increases steadily from 1.58 nucleosomes per 10 nm in the absence of NaCl to 7.66 nucleosomes per 10 nm at 50 mM NaCl. However, since calibration with TMV tends to overestimate the Mc value, the actual Mc values may be less than those values. Above about 40 mM NaCl, aggregation of chromatin is suggested. Similar analysis of H1-depleted chromatin confirmed that H1-depleted chromatin takes a more disordered structure than native chromatin at low ionic strength and does not undergo a definite structure change upon further addition of NaCl.

Animals↗
PubMed1989

Reversibility of pulmonary telangiectasia in liver cirrhosis evidenced by serial dynamic pulmonary perfusion imaging.

Pulmonary perfusion imaging with Tc-99m MAA revealed significant uptake in the lungs, brain, spleen, and both kidneys of a 48-year-old woman with liver cirrhosis and pulmonary telangiectasia associated with marked hypoxemia and cyanosis. Dynamic pulmonary perfusion imaging revealed a gradual reduction after peak uptake in both lungs. Several weeks after albumin replacement, the hypoxia and dyspnea disappeared with no change in hepatocellular function. At that time, dynamic pulmonary perfusion imaging revealed a plateau-like time-activity curve of uptake in the lungs, as compared with the findings obtained during the state of severe hypoxemia. These observations suggest that pulmonary telangiectasia in a patient with liver cirrhosis may be due to functional vasodilatation. Serial dynamic pulmonary perfusion imaging indicates the passage of the MAA particles through the widened lumen of the pulmonary alveolar capillaries.

Female↗
PubMed1989

[Bladder carcinoma in situ which harbored human papilloma virus. A case report].

Last year, we reported that human papilloma virus type 16 genome (HPV 16 genome) was detected in a case (S.Y.) of bladder carcinoma in situ (bladder CIS) (Cancer Res., 1988). Since then, a number of bladder tumors other than CIS were searched for HPV genome. However, no HPV genome was detected in the bladder tumors. From the results, we consider that HPV may not have a relation with all types of bladder tumor but with only a part of it. In the current report, the case (S.Y.) is presented more precisely than before, in particular on the characteristic bladder lesion. The patient was a 40-year-old female with immunodeficiency and anemia who was referred from a hospital with a complaint of asymptomatic pyuria. Cystoscopic examination revealed a bladder tumor, well-demarcated, white and velvety lesion with slight elevation. On November 25, 1987, she underwent total cystectomy, resection of the anterior vaginal wall and of a part of vulval skin, and ileal conduit formation. Postoperative course was stormy because of bleeding from the wounds and thrombophlebitis in the right femoral vein. In spite of the episodes, she eventually recovered and was discharged 2 months later. However she was readmitted 9 months later due to severe anemia which was ascribed to acute myelogenous leukemia. She is now on cancer chemotherapy for leukemia.

Adult↗
PubMed1989

[M-VAC (methotrexate, vinblastine, adriamycin and cisplatin) chemotherapy in advanced renal pelvic and ureteral carcinoma].

Seventeen patients with advanced renal pelvic and ureteral carcinoma receiving M-VAC chemotherapy were evaluated. There were 10 men and 7 women ranging in age from forty-two to seventy-eight years with a mean of sixty-six years. The primary sites of carcinoma were renal pelvis in 4 patients, ureter in 12, renal pelvis and ureter in 1. Fifteen patients had transitional cell carcinoma, one patient had transitional cell carcinoma mixed with squamous cell carcinoma and the histology of one patient was not identified. The median number of treatment cycles was 2.6, ranging from 1 to 6. Significant remissions following the treatment were observed in 5 of 8 primary lesions, 6 of 11 lymph nodes, 2 of 3 lung lesions and 2 of 5 bone lesions, respectively. However, the responses were not seen in 4 liver lesions. Two patients achieved a complete response (CR), 7 had a partial response (PR), 6 had stabilization of their disease, 2 had progressed, and the overall response rate was 52.9%. Two CR patients remain free of disease. Relapse or recurrence was seen in 4 of the 7 patients who achieved PR, and the median duration of response was 6.4 months. While the myelosuppression with this regimen was tolerable, the decreases of white blood cell and platelets count were significant in patients who had undergone prior irradiation. These results indicate that the M-VAC regimen is effective in patients with advanced upper urothelial malignancy. Further, a short response and a poor effectiveness in the metastases of liver and bone remain to be overcome.

Adult↗
PubMed1989

[M-VAC chemotherapy for patients with lymph node metastases and/or locally advanced bladder carcinoma].

Sixteen patients with lymph nodes metastases and/or locally advanced bladder carcinoma were treated with a combination chemotherapy regimen consisting of methotrexate, vinblastine, adriamycin, and cisplatin (M-VAC) from November 1986 through September 1988. There were 14 men and 2 women. The median age was 61.9 years, with a range from 43 to 81 years. Complete response (CR) was observed in 6 of 16 patients (38%), partial response (PR) was confirmed in 5 of 16 patients (31%), and overall response rate was 69%. Median duration of response was 10.3 and 5.2 months in CR and PR patients, respectively. The myelosuppression with this regimen was tolerable. This study demonstrates that the M-VAC regimen is effective in the invasive bladder carcinoma with or without lymph nodes metastases. However, the duration of response is relatively short, and the true long-term benefits of this regimen remain to be determined.

Adult↗