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Biomedical subjects

T Tamura

Publications and source records attributed to T Tamura.

At least 847 records · Page 47Linked to original sources
PubMed1991

Late toxicities and complications in three-year survivors of small cell lung cancer.

123 patients with small cell lung cancer (SCLC) presented to the National Cancer Center Hospital (Tokyo) between 1978 and 1986. 22 of 71 patients with limited stage disease (LD) and none of 52 patients with extensive disease (ED) survived for 3 years. 15 of the 22 three year survivors had significant late complications. All patients received chemotherapy and either thoracic irradiation, resection or both. No prophylactic cranial irradiation was given. 4 patients developed cardiac failure, 2 with a dilated cardiomyopathy, despite the fact that no patient received over 420 mg/m2 of doxorubicin. 12 patients of the 17 who received thoracic irradiation developed radiation pneumonitis and 3 required hospitalisation for severe haemoptysis (2) or cavity formation (1). 1 patient who received nimustine developed a fatal myelodysplastic syndrome and 2 additional patients developed second primary tumours in the oesophagus (1) and stomach (1). Mild peripheral neuropathy (WHO grade 1) was persistent in 3 patients and asymptomatic azotemia (WHO grade 1) in 7. Despite advances in the treatment of SCLC there are very few asymptomatic long-term survivors.

Adult↗
PubMed1991

Quantitative study of steady flow using color Doppler ultrasound.

The use of color Doppler flow mapping systems for quantitative in vitro studies of flow fields is examined and illustrated. A 5-MHz color Doppler system was used, and the resolution was determined by comparing the results of flow-field measurement for steady parabolic pipe flow with calculated values. The velocity accuracy was about 6% of the velocity corresponding to half the pulse repetition frequency, and the spatial resolution was better than 1 mm. Frame frequency limitations permitted only partial tracking of fast temporal changes in the flow field. However, detection of vortices downstream from a small cylinder placed in the flow tube was significantly enhanced by synchronizing the frame frequency with the vortex shedding frequency and using a velocity-variance mode. Color Doppler aliasing was found to be useful to define streamlines and determine whether the flow was laminar or turbulent. The color Doppler system clearly imaged Poiseuille, transitional and turbulent flow and vortex shedding in vitro. It is concluded that color Doppler ultrasound flow mapping can enable large, complex flow fields to be quantitatively studied in vitro.

Blood Flow Velocity↗
PubMed1991

Molecular cloning and mapping of 10 new probes on the human Y chromosome.

We have developed a novel positive cloning vector whose use precludes the cloning of any fragments less than 0.8 kb as well as 3.4-kb EcoRI fragments of DYZ1, the largest repeating-DNA family on the long arm of the human Y chromosome. Using this vector, we subcloned inserts of a Y-chromosome-specific phage library constructed from EcoRI-digested flow-sorted Y-chromosome DNA. Ten novel Y-specific fragments were obtained. Their localization on the Y chromosome was determined by deletion mapping using clinical samples with structurally abnormal Y chromosomes. The long arm of the Y chromosome was divided into 12 segments by the novel probes in combination with established probes. The amelogenin-like sequence, mapped on the long arm in Human Gene Mapping 10, has been mapped on the short arm.

Amelogenin↗
PubMed1991

Light adaptation in retinal rods of the rabbit and two other nonprimate mammals.

The responses of rabbit rods to light were studied by drawing a single rod outer segment projecting from a small piece of retina into a glass pipette to record membrane current. The bath solution around the cells was maintained at near 40 degrees C. Light flashes evoked transient outward currents that saturated at up to approximately 20 pA. One absorbed photon produced a response of approximately 0.8 pA at peak. At the rising phase of the flash response, the relation between response amplitude and flash intensity (IF) had the exponential form 1-e-kappa FIF (where kappa F is a constant denoting sensitivity) expected from the absence of light adaptation. At the response peak, however, the amplitude-intensity relation fell slightly below the exponential form. At times after the response peak, the deviation was progressively more substantial. Light steps evoked responses that rose to a transient peak and rapidly relaxed to a lower plateau level. The response-intensity relation again indicated that light adaptation was insignificant at the early rising phase of the response, but became progressively more prominent at the transient peak and the steady plateau of the response. Incremental flashes superposed on a steady light of increasing intensity evoked responses that had a progressively shorter time-to-peak and faster relaxation, another sign of light adaptation. The flash sensitivity changed according to the Weber-Fechner relation (i.e., inversely) with background light intensity. We conclude that rabbit rods adapt to light in a manner similar to rods in cold-blooded vertebrates. Similar observations were made on cattle and rat rods.

Adaptation, Ocular↗
PubMed1991

Calcium feedback and sensitivity regulation in primate rods.

Membrane current was recorded from a single primate rod with a suction pipette while the cell was bath perfused with solutions maintained at a temperature of approximately 38 degrees C. A transient inward current was observed at the onset of bright illumination after briefly exposing the outer segment in darkness to Ringer's (Locke) solution containing 3-isobutyl-1-methylxanthine (IBMX), an inhibitor of cGMP phosphodiesterase. After briefly removing external Na+ from around the outer segment in darkness, a similar current was observed upon Na+ restoration in bright light. By analogy to amphibian rods, this inward current was interpreted to represent the activity of an electrogenic Na(+)-dependent Ca2+ efflux, which under physiological conditions in the light is expected to reduce the free Ca2+ in the outer segment and provide negative feedback (the "Ca2+ feedback") to the phototransduction process. The exchange current had a saturated amplitude of up to approximately 5 pA and a decline time course that appeared to have more than one exponential component. In the absence of the Ca2+ feedback, made possible by removing the Ca2+ influx and efflux at the outer segment using a 0 Na(+)-0 Ca2+ external solution, the response of a rod to a dim flash was two to three times larger and had a longer time to peak than in physiological solution. These changes can be approximately accounted for by a simple model describing the Ca2+ feedback in primate rods. The dark hydrolytic rate for cGMP was estimated to be 1.2 s-1. The incremental hydrolytic rate, beta*(t), activated by one photoisomerization was approximately 0.09 s-1 at its peak, with a time-integrated activity, integral of beta*(t)dt, of approximately 0.033, both numbers being derived assuming spatial homogeneity in the outer segment. Finally, we have found that primate rods adapt to light in much the same way as amphibian and other mammalian rods, such as showing a Weber-Fechner relation between flash sensitivity and background light. The Ca2+ feedback model we have constructed can also explain this feature reasonably well.

1-Methyl-3-isobutylxanthine↗
PubMed1991

Pteroylpolyglutamates in human milk.

Considerable variation exists in reported values for total folate content and the pteroylpolyglutamate (PteGlun) content of human milk. We investigated possible methodological sources of this variation. In two laboratories, milk folate content (with and without folate conjugase) was determined microbiologically. No differences in total milk folate or PteGlun (n greater than 3) content were found between laboratories. PteGlun was found to comprise a significant fraction of total milk folate (28%). Use of rennin did not alter total folate content nor the percent of PteGlun in human milk. Heating (121 degrees C for 5 min) increased folate concentrations (190%, P less than 0.0001), indicating that release of folate from binding protein is necessary for folate utilization by Lactobacillus casei. Although human milk folate conjugase, (FC) activity was approximately one-twentieth that of plasma FC activity, it was not sufficient to autolyze endogenous PteGlun. Thus, microbiological protocols that do not use folate conjugase and do not release folate from binding proteins will seriously underestimate milk folate values.

False Negative Reactions↗
PubMed1991

Influence of dietary intakes of erythorbic acid on plasma vitamin C analyses.

D-Erythorbic acid is an epimer of L-ascorbic acid, but lacks antiscorbutic activity. It is commonly used as a food additive, particularly in processed meat items. Except for high-performance liquid chromatography (HPLC) methodology, the commonly used analytical procedures to measure vitamin C do not distinguish between the two isomers. A study with seven adult women demonstrated that the concentration of erythorbic acid present in food items commonly consumed was sufficient to produce interference in plasma vitamin C analyses. With the meals used, 7-23% of the apparent vitamin C in plasma obtained 2 h after the ingestion of the meals was actually erythorbic acid when analyzed by HPLC. To avoid falsely high plasma-serum vitamin C values as a result of erythorbic acid ingestion, the analyses should be conducted on overnight fasting blood specimens or with the use of an HPLC-amperometric method.

Adult↗
PubMed1991

The absorption of pteroylpolyglutamate and intestinal pteroylpolygammaglutamyl hydrolase activity in zinc-deficient rats.

The effect of dietary zinc deficiency on pteroylpolygammaglutamyl hydrolase (folate hydrolase) activity and on pteroylpolyglutamate absorption was studied in rats. Three groups of male Sprague-Dawley rats (zinc-deficient, restricted-fed and ad libitum-fed controls) were fed a semipurified 25% egg white protein diet. The zinc-deficient group received 0.7 mg zinc/kg diet, whereas restricted-fed and ad libitum-fed control groups received 106 mg zinc/kg diet. After 6 wk of feeding, intestinal mucosal folate hydrolase activity was determined, and the absorption of pteryl-U[14C]glutamylhexaglutamic acid [(14C]PteGlu7) and [3H]pteroylglutamic acid [(3H]PteGlu) was measured after intragastric administration. The intestinal mucosal folate hydrolase activity of zinc-deficient rats was not significantly reduced compared with two control groups. No significant differences in the absorption of [14C]PteGlu7 and [3H]PteGlu were found among the three groups. These results indicate that intestinal folate hydrolase is not zinc dependent in rats and the intestinal absorption of pteroylpolyglutamate is not reduced in zinc-deficient rats.

Animals↗
PubMed1991

Congenital laminar defect of the upper lumbar spine associated with pars defect. A report of eleven cases.

Lumbar spondylolysis generally is considered to be a fatigue fracture of the pars interarticularis, and no unequivocal case of congenital spondylolysis has been reported. The authors describe 11 cases of unilateral spondylolysis (possibly congenital laminar defect associated with pars defect) of the upper lumbar spine. They have roentgenographic characteristics distinct from conventional spondylolysis of the lumbar spine, including hypoplasia of the spinal accessory process, rotation of the spinous process contralaterally to the spondylolysis, and prominent ipsilateral lamina. The anomaly found in these 11 patients probably is congenital, and its clinical significance is not known.

Adolescent↗
PubMed1991

A simple technique for cervical myelography.

A new method has been devised for obtaining high-quality cervical myelograms safely and easily through lumbar injection. This method uses simple radiographic equipment, and does not require a tiltable table or fluoroscopy. Fifty-seven patients with cervical disorders were examined by this method using 9.5 ml of iohexol (300 mg l/ml), and successful myelograms were obtained in all patients. No serious complications were encountered.

Adult↗
PubMed1991

Polyacrylamide gel electrophoresis analysis of ribosomal protein AT-L30 as a novel approach to actinomycete taxonomy: application to the genera Actinomadura and Microtetraspora.

Actinomycete ribosomal protein AT-L30 exhibits electrophoretic mobility that is specific for each genus. On the basis of this fact, we analyzed ribosomal AT-L30 proteins from 26 type strains of species belonging to the genera Actinomadura and Microtetraspora. The electrophoretic mobilities of AT-L30 preparations from these strains, as determined by two-dimensional polyacrylamide gel electrophoresis, revealed that they could be divided into two groups, one group with relative electrophoretic mobilities of 14.0 to 41.5 and another group with relative electrophoretic mobilities of -6.5 to 0. The first group corresponded to the genus Actinomadura, and the second group corresponded to the genus Microtetraspora. Partial amino acid sequencing of AT-L30 preparations from several strains proved that we were indeed dealing with the specified protein homologous to ribosomal protein L30 of Escherichia coli. Our results strongly supported the conclusions of previous work and thus proved the efficacy of ribosomal protein analysis as a novel approach for taxonomy of actinomycetes.

Actinomycetales↗
PubMed1991

Oral contraceptive-induced lupus erythematosus in a Japanese woman.

A case of oral contraceptive-induced lupus erythematosus (LE) was reported. Erythematous skin lesions were noticed on hypothenor sites of palms and acral sites of pedes. Abnormal laboratory findings included an elevated ESR, CRP and weakly positive anti-nuclear antibodies. Skin biopsy specimens from involved skin showed Clq deposits at the dermo-epidermal junction. LE-like symptoms were considered to be induced by oral contraceptives, because her symptoms disappeared after the oral contraceptives were discontinued.

Adult↗
PubMed1991

Short arm deletion of chromosome 1: del(1)(p13.3 p22.3) in a female infant with an extreme tetralogy of Fallot.

High-resolution chromosome analysis showed the karyotype 46,XX,del(1)(p13.3 p22.3) in a female infant with an extreme tetralogy of Fallot and multiple congenital anomalies. The patient showed characteristic features: upper and lower eyelids connected to each other by a string-like epithelium, low hairline, epicanthal folds, saddle nose with a broad, flat root, micrognathia, short neck, high-arched palate, prominent xiphisternum, wide-spaced nipples, bilateral pes equinovarus, fifth toes that overlapped the fourth toes bilaterally, a deep fissure between the first and second toes bilaterally, and abnormal flexions of fingers and toes. Growth and psychomotor retardation were also noted. Cardiac catheterization revealed an extreme tetralogy of Fallot complicated by a patent ductus arteriosus. Ventricular tachycardia and ventricular premature beats developed during the neonatal period and did not respond well to anti-arrhythmic drugs. She died of the anoxia caused by closure of the patent ductus arteriosus when she was 7 months old.

Cardiac Catheterization↗
PubMed1991

Transitional cell carcinoma with sarcomatous elements in the urinary tract. Six cases examined by immunohistochemistry.

We report six cases of carcinoma showing sarcomatous change in the urinary tract examined by conventional histochemistry and immunohistochemistry. All of the cases were transitional cell carcinoma with or without focal squamous cell carcinoma. Sarcomatous components resembling spindle cell sarcoma with a marked myxoid stroma or chondrosarcomatous element were also observed in all cases. The sarcomatous elements were closely associated with the areas of squamous cell carcinoma in three cases. Various histochemical staining procedures demonstrated mesenchymal features in the stroma of sarcomatous areas. By immunohistochemical examination, the epithelial components showed positive reactions for keratin, epithelial membrane antigen and, focally, carcinoembryonic antigen. The sarcomatous components revealed a positive immunoreaction for keratin but lacked other epithelial markers in all cases. Chondrosarcomatous elements in two cases were positive for both keratin and S-100 protein. These findings indicate that sarcomatous elements in carcinoma may represent mesenchymal metaplasia with partial or complete loss of epithelial features. However, further study will be necessary in order to determine whether heterogeneous elements, such as chondrosarcomatous areas, are epithelial or truly mesenchymal in origin.

Aged↗
PubMed1991

Intravenous gamma-globulin for Kawasaki disease.

We studied the effect of gamma-globulin (IVGG) and aspirin (ASA) on the development of the coronary artery lesions (CAL) of Kawasaki disease (KD) in three different protocols. Within 29 days of the onset of KD the echocardiographic evidence of CAL had developed in 39-42% of the patients in the ASA group, but only in 13.7-20.8% of the patients treated with IVGG (200 or 400 mg/kg X 5). In long-term follow-up observation of CAL of these patients the evidence of CAL in both the ASA and the IVGG group regressed gradually; however, the residual rate of CAL was significantly low in the IVGG group at all times up to 24 months after onset. These facts suggest that when using IVGG for KD, we should select a dose of intact gamma-globulin, 1,000 mg/kg or more in total, to prevent the occurrence of CAL. We have demonstrated not only a significant reduction in the occurrence of CAL in patients treated with IVGG but a reduction in the residual rate of CAL for two years as compared with those treated by ASA.

Aspirin↗
PubMed1991

Lansoprazole, a novel benzimidazole proton pump inhibitor, and its related compounds have selective activity against Helicobacter pylori.

The activities of various types of antiulcer agents against Helicobacter pylori (formerly called Campylobacter pylori) strains were determined by an agar dilution method. Among the compounds tested, two benzimidazole proton pump inhibitors, lansoprazole (AG-1749) and omeprazole, were found to have significant activities against this organism. The activity of lansoprazole was comparable to that of bismuth citrate, with MICs ranging from 3.13 to 12.5 micrograms/ml, and fourfold more potent than that of omeprazole. A major metabolite and two acid-converted rearrangement products of lansoprazole also exhibited good activities comparable or superior to that of the parent compound. Exposure to lansoprazole of H. pylori growing in a liquid medium led to an extensive loss of viability without a reduction in culture turbidity and produced an aberrant bacterial morphology characterized by the irregular constriction of cells and the collapse of cell surface structures. The antibacterial activity of lansoprazole and its related compounds was selective against H. pylori; common aerobic and anaerobic bacteria and Campylobacter jejuni were not inhibited by 100 micrograms/ml.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1991

Reassessment of the v-fms sequence: threonine phosphorylation of the COOH-terminal domain.

The v-fms oncogene product of the McDonough strain of feline sarcoma virus is a member of the receptor tyrosine kinase family. Its cellular counterpart, the c-fms product, is the receptor for colony-stimulating factor 1 (CSF-1) of macrophages. We have reanalyzed the v-fms gene by direct sequencing of a biologically active clone. An additional A nucleotide was detected in position 2810 of the published v-fms sequence. The frameshift changed the COOH-terminal sequence of the v-fms protein from -R-937-G-P-P-L-COOH to -Q-937-R-T-P-P-V-A-R-COOH. Antibodies against a synthetic peptide representing this new sequence precipitated the v-fms proteins from transformed NRK cells as well as from feline sarcoma virus (McDonough)-infected feline fibroblasts. We show by tryptic peptide mapping that threonine 939 present in the new sequence is phosphorylated by a yet unknown serine/threonine kinase in vivo. In chicken fibroblasts expressing the v-fms gene, this phosphorylation clearly depended on the addition of exogenous CSF-1. Furthermore, addition of CSF-1 appeared to activate the serine/threonine kinase, as judged by phosphorylation of the synthetic peptide QRTPPVAR.

Amino Acid Sequence↗