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Biomedical subjects

S Kitabatake

Publications and source records attributed to S Kitabatake.

15 recordsLinked to original sources

Confocal endomicroscopy for the diagnosis of gastric cancer in vivo.

BACKGROUND AND STUDY AIMS: Advances in endoscopy have led to imaging of the details of the gastric mucosa, but the histological diagnosis usually has to be confirmed by endoscopic biopsy. A method of confocal endomicroscopy that has recently been developed allows the observation of living cells in vivo. Several investigators have reported that the technique is of value, but there have as yet been no studies describing its application in gastric cancer. PATIENTS AND METHODS: Twenty-seven patients with early gastric cancer underwent confocal endomicroscopy (Pentax EG-3870CIK; Pentax, Tokyo, Japan). After intravenous administration of fluorescein sodium, confocal images obtained from the normal mucosa and from cancerous lesions were interpreted by two pathologists independently and compared with the histological findings, including CD34 immunostaining of biopsy specimens or resected specimens from the same sites. RESULTS: Fluorescein yielded high-quality confocal images of the gastric mucosa; if cancer could be targeted (59%) images were mostly graded good. The images corresponded to the hematoxylin-eosin staining of transverse sections of specimens from the same sites. In the results for the interpretation by the two pathologists, the accuracy for the diagnosis of gastric cancer was 94.2% (pathologist A), and 96.2% (pathologist B), respectively. The accuracy decreased substantially when poor images and inaccessible lesions were included. CONCLUSIONS: Confocal endomicroscopy is useful in the diagnosis of gastric cancer but good quality images cannot always be obtained. In the future, it may allow virtual biopsy and help reduce unnecessary biopsies.

Adenocarcinoma↗

Gastrin and Helicobacter pylori in low-grade MALT lymphoma patients.

BACKGROUND: This study of patients with Helicobacter pylori infection and low-grade MALT lymphoma aimed to investigate: 1) the effect of H. pylori eradication therapy on the serum gastrin level, 2) whether changes of the serum gastrin level after therapy could predict the prognosis of patients with this tumour, and 3) the relationship between the gastric H. pylori load, the serum gastrin level and the status of MALT lymphoma. METHODS: Thirteen patients with documented low-grade MALT lymphoma and H. pylori infection were enrolled and received H. pylori eradication therapy as the sole initial treatment. The presence of H. pylori, the serum gastrin level, the endoscopic findings, the pathologic features of the biopsies and resected specimens, and the endoscopic ultrasonography findings were evaluated before and after therapy. Follow-up was carried out every 3-6 months. RESULTS: H. pylori eradication was eventually achieved in all 13 patients. The pretreatment fasting serum gastrin level decreased from 177.1 +/- 107.4 pg/ml to 129.2 +/- 78.1, 96.4 +/- 66.6 and 80.1 +/- 42.7 pg/ml after 0-3, 3-6 and 6-9 months, respectively (all P < 0.05). Successful eradication of H. pylori was followed by a decrease of the fasting serum gastrin level and complete regression of initial low-grade MALT lymphoma was observed in all patients. However, two patients subsequently developed recurrent high-grade MALT lymphoma or high-grade lymphoma. In one of them, the serum gastrin level rose again above the pretreatment value. In the other, however, the fasting gastrin level fell throughout the study period. The median fasting serum gastrin level before H. pylori eradication therapy was higher in the patients with tumours of the gastric body (203.4 +/- 108.9 pg/ml) than in those with tumours of the antrum and angulus (89.3 +/- 28.0 pg/ml) (P = 0.06). CONCLUSIONS: Hypergastrinaemia may be associated with an increased risk of gastric MALT lymphoma.

Adult↗

Synthesis of P1,P4-di(adenosine 5'-) tetraphosphate by leucyl-tRNA synthetase, coupled with ATP regeneration.

A simple and practical procedure for the synthesis of P1,P4-di(adenosine 5'-) tetraphosphate from ATP by the catalysis of leucyl-tRNA synthetase from Bacillus stearothermophilus is described. Km for leucine was 6.7 microM and for ATP was 3.3 mM. The reaction yielded not only diadenosine tetraphosphate, but various byproducts such as P1,P3-(diadenosine 5'-) triphosphate, ADP and AMP. By coupling the reaction with an ATP regeneration system by acetate kinase and adenylate kinase with acetylphosphate as a phosphate donor, diadenosine tetraphosphate was prepared as a sole product at a high yield (96%).

Adenine Nucleotides↗

A novel method for the synthesis of kyotorphin, Tyr-Arg, and 3H-Tyr-Arg, catalyzed by tyrosyl-tRNA synthetase from Bacillus stearothermophilus.

A novel method of dipeptide synthesis is described that can be carried out in aqueous solution and does not require complicated protecting and deprotecting procedures. An analgesic neuropeptide named kyotorphin, H-Tyr-Arg-OH, was synthesized from unprotected tyrosine and arginine in a new enzymatic reaction catalyzed by immobilized tyrosyl-tRNA synthetase from Bacillus stearothermophilus. The reaction could be a useful tool in the syntheses of radioisotope-labeled oligopeptides to be used in receptor binding assays. 3H-Kyotorphin was prepared by this method at a yield of 72% and could be used in receptor binding assays after a single chromatographic separation.

Amino Acyl-tRNA Synthetases↗

Dipeptide synthesis catalyzed by aminoacyl-tRNA synthetases from Bacillus stearothermophilus.

A new approach to enzymatic peptide synthesis by using aminoacyl-tRNA synthetase (ARS) as a catalyst has been investigated. Four ARSs (AspRS, HisRS, LeuRS and TyrRS) have been purified from a thermophilic bacterium, Bacillus stearothermophilus. By using TyrRS as a catalyst, tyrosine and leucinamide were shown to be condensed in the presence of ATP to give tyrosylleucinamide. In this manner, all of the ARSs investigated catalyzed the peptide synthesis reactions. TyrRS did not have strict specificity for the amino acid derivatives used as substrates and even D-amino acids were incorporated into peptides fairly easily in this enzymatic reaction. Preparative scale synthesis of L-Tyr-L-LeuNH2 was carried out and from this the scope and limitation of this new enzymatic reaction as a tool to the peptide synthesis has been described.

Amino Acyl-tRNA Synthetases↗

Serum coenzyme Q10 levels in thyroid disorders.

The correlation between serum CoQ10 levels and serum thyroid hormones in thyroid disorders was investigated in the present studies. Serum CoQ10 was measured by high speed liquid chromatography utilizing ultraviolet detector. In normal controls, serum CoQ10 level of the male was higher than that of the female. Serum CoQ10 level in hyperthyroidism was significantly lower than that of euthyroid subjects. But in hypothyroidism, serum CoQ10 level did not show any significant difference from that of euthyroid subjects. Significant inverse correlations were demonstrated between log CoQ10 and log T3, log T4, log free T4, or log rT3. These data suggested abnormalities in the mitochondrial electron transport system in thyroid disorders.

Adolescent↗

Closer correlation between serum triiodothyronine and basal metabolic rate during antithyroid drug treatment in patients with Graves' disease.

The correlations between serum triidothyronine (T3), thyroxine (T4), 131I-triiodothyronine resin sponge uptake (RT3U) or free thyroxine index (T7) and the basal metabolic rate (BMR) during antithyroid drug treatment in 86 patients with Graves' disease were investigated. Although serum T3, T4, RT3U and T7 during therapy with MMI showed significant positive correlations with BMR, the coefficient of correlation (r = 0.6088, P less than 0.001) between T3 and BMR was the highest of all. While the normal range of BMR in control subjects was between -1.9 and +14.9 (the range of mean +/- SD), the corresponding values of T3, T4, RT3U and T7 calculated from the regression lines, ranged from 94.2 to 184.0 ng/dl, from 5.32 to 8.75 microgram/dl, from 26.5 to 28.9% and from 1.57 to 2.47 respectively. On the other hand, when the corresponding values of BMR to normal values of T3 (100-170 ng/dl), T4 (7.6-12.2 microgram/dl), RT3U (26.7-36.5% and T7 (2.29-3.49) in control subjects were calculated from the regression lines, the range of value obtained from the regression line of T3 coincided better with normal value of BMR in control subjects that those calculated from other regression lines (T4, RT3U and T7). These results suggest that serum T3 level would be a better index of evaluation of the thyroid function that T4 or RT3U in patients with Graves' disease under antithyroid drug treatment.

Adolescent↗