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Biomedical subjects

T Tsuchiya

Publications and source records attributed to T Tsuchiya.

At least 397 records · Page 22Linked to original sources

The effect of carbohydrate sulfate salts on the absorption and excretion of paraquat in rats.

The effect of carbohydrate sulfate salts on the absorption and excretion of the herbicide, paraquat dichloride (PQ), was investigated in rats. A mixture of PQ and sodium dextran sulfate (DS) or sodium glucose sulfate (GS) was given orally to rats and then feces and urine were collected daily for 14 d. The cumulative amount of PQ excreted in the feces of rats given the mixture PQ and DS, or PQ and GS was 82.6% and 76.7% respectively. When PQ alone was administered, 56.7% was excreted in feces. Most (nearly 90%) of the PQ detected in feces was excreted within the first 24 h of the 14 d period in each case. The cumulative amount of PQ excreted in the urine over the 14 d period was 1.2% for the mixture PQ and DS and 0.7% for the mixture PQ and GS. When PQ was given alone the corresponding figure was 7.2%. In addition, the effect of DS and GS on PQ absorption from the rat small intestine was investigated using an in situ recirculating perfusion method. During 180 min period of recirculating perfusion, using PQ alone in normal saline, 13.4% of the herbicide was absorbed from the intestine. However, when the mixture of PQ and DS (or PQ and GS) in saline was used, the absorption was 3.9% for PQ-DS, of 4.8% for PQ-GS. Furthermore, an association of PQ with DS, or GS, was observed using gel filtration of the mixture of PQ-DS and PQ-GS in saline solution.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

The short- and long-term prognosis for acute myocardial infarction after emergency coronary angioplasty.

The short- and long-term prognosis for acute myocardial infarction after reperfusion was examined in 175 patients with successful emergency angioplasty and in 29 failed cases. During hospitalization, more cardiac events occurred in the failed group than in the successful group (58.6% versus 12.6%; p < 0.001), especially cardiac death and coronary bypass surgery (27.6% versus 4.0%, and 41.4% versus 4.6%; p < 0.001, respectively). The only difference found in the incidence of post-discharge cardiac events was a higher frequency of cardiac death in the failed group (9.5% versus 1.2%; p < 0.02). The failed group also had a lower cumulative survival rate at 5 years (69.0% versus 95.3%; p < 0.01). Cox proportional hazard analysis showed that the results of angioplasty, cardiac index, peak creatine kinase level, and the number of diseased vessels were significant independent variables for the prediction of subsequent cardiac death at long-term follow-up. Thus, successful reperfusion by emergency angioplasty improved the prognosis of acute myocardial infarction, even when other important variables were considered.

Adult↗

Measurement of transverse stiffness during contraction in frog skeletal muscle using scanning laser acoustic microscope.

The change in the transverse propagation velocity was measured by the scanning laser acoustic microscope (SLAM) during contraction in living frog skeletal muscles. The images of the interferogram were processed by image-analyzer and the propagation velocity was calculated from the shift of the interference lines at rest and during contraction. In all the measurements, the velocities during contraction were clearly slower than at rest and this fact indicates that the transverse stiffness decreased during contraction. After stimulation, the beginning of the decrease in the propagation velocity preceded that of the increase in force by 30-40 ms, suggesting that the decrease in the transverse stiffness reflects the molecular mechanism of force development in muscular contraction.

Acoustics↗

Synthesis of 3-deoxy-3,4-didehydro derivatives of 5-O-mycaminosyltylonolide, 5-O-(4-deoxymycaminosyl) tylonolide, and desmycosin.

The 3-deoxy-3,4-didehydro derivatives of 5-O-mycaminosyltylonolide, 5-O-(4-deoxymycaminosyl)tylonolide, and desmycosin have been prepared by treatment of the corresponding 3-O-sulfonyl derivatives with NaI in 2-butanone as the key step. The mechanistic difference in the formation of the 2,3- and 3,4-unsaturated derivatives from the same 3-O-sulfonyl derivative is discussed.

Anti-Bacterial Agents↗

[Acute mixed lineage leukemia showing resistance to AML and ALL therapy].

A 51-year-old female was who admitted complaining of cough and slight fever and lower limb petechia. The laboratory examinations revealed leukocytosis (49,400/microliters) with blasts (71%) in the peripheral blood. The NCC was 30 x 10(4)/microliters with 84.8% blasts in the bone marrow. Myeloperoxidase staining was positive for 6% of blasts. Auer rods were not seen in some blasts. Thus, acute myeloblastic leukemia (M1) was diagnosed according to FAB classification. In the peripheral blood, 43.3% of blasts expressed CD19, 10.3% of blasts expressed CD20 and 55.6% of blasts expressed CD33 on admission. Though she received two courses of DCMP according to the DCMP-85 protocol, and one combined course of mitoxantrone, etoposide, and Ara-C. The NCC was 20.0 x 10(4)/microliters with 70% blasts in the bone marrow. CD19 was expressed by 72.4% of blasts and 35.0% expressed CD20. The ALL-90 protocol was started, but remission was not achieved. Thus this case was considered to be acute mixed lineage leukemia.

Antigens, CD↗

[Estimation of effective half life of 131I in radioiodine therapy for Graves' disease using a single radioiodine uptake measurement].

Calculation of the absorbed radioiodine dose in the thyroid gland is a very important factor in 131I therapy for Graves' disease. In 131I therapy, the measurement of the effective half life (EHL) of radioiodine in the thyroid gland is indispensable for calculating the absorbed radioiodine dose. In some cases, however, EHL cannot be calculated because repeated measurements of thyroid uptake cannot be done. So, the authors developed a new method to estimate EHL using a single radioiodine uptake measurement. The activity of intrathyroidal 131I (thyroid uptake) and that of the surrounding area of the shielded thyroid (body background) were measured at 24 hours after the administration of 131I. The ratio of the value of body background to thyroid uptake was calculated. This ratio was multiplied by 100 and the calculated value was named the EHL-index. The relationship between actual measured EHL and the EHL-index was expressed by a regression line and/or a hyperbola. For the purpose of obtaining more actual values of EHL using the EHL-index, the new combined curve was composed of the regression line and the hyperbola. As for the value of calculated EHL compared with that of actual measured EHL, about 80 percent of calculated EHL values were within acceptable error ranges. These results indicate that EHL can be estimated by a single measurement 24 hours after administration of 131I. This method should be very useful in the therapy of Graves' disease with 131I when the thyroid measurement is performed only one time.

Graves Disease↗

New experimental model of proximal and distal colon transposition in rats.

The proximal and distal portions of the colon have different morphologic and histochemical features. To ascertain whether these features are genetically or environmentally determined, we attempted to develop a transposition model of the proximal and distal portions of the colon in rats. Four-month-old male Fisher 344 rats were used. Four centimeters of the proximal colon segment circulated by the right colonic artery and 4 cm of the distal colon segment circulated by the middle colic artery were interchanged isoperistaltically. In the control group, the colon was transected and reanastomosed. All rats tolerated the surgery and maintained good condition for 4 weeks, when they were euthanized. No differences in body weight and food intake were observed between the transposition and control groups. Macroscopic appearance of the stomach and small intestine was normal in both the transposition and control groups, but the cecum was dilated and the new proximal portion of the colon was slightly dilated in the transposition group. This new experimental model will be helpful in examining the mechanism by which different features of the proximal and distal portions of the colon are derived. It will also assist in the research of carcinogenesis in the colon, in determining why the distal portion of the colon is more susceptible to carcinogens, compared with the proximal portion of the colon.

Animals↗

[Herpetic simplex encephalitis followed by myelopathy].

A 48-year-old male was admitted to our hospital because of fever, headache and vomiting. At admission, the level of consciousness was depressed (drowsy) with slight confusion. Extremely miotic pupils, nuchal stiffness, ataxia and myoclonic movements of both upper limbs were observed. The eye movements were almost normal and there was no definite limb weakness or sensory impairment. A few days after admission, his level of consciousness further decreased, and opsoclonus, ataxic breathing and intestinal paralysis appeared. The body temperature fluctuated remarkably ranging from 33.0 degrees C to 39.0 degrees C. The cerebrospinal fluid (CSF) examination revealed lymphocytic dominant pleocytosis, increase of protein and decrease of glucose. Enzyme-linked immunosorbent assay (ELISA) showed increased antibody (IgG) to herpes simplex virus (HSV) in both serum and CSF. The antibody in CSF further elevated at the later examination. Magnetic resonance imaging (MRI) demonstrated high signal intensity areas mainly in the cerebellum and sporadically in the supratentorial subcortical white matter on T2-weighted images. Administration of Gadolinium-DTPA also revealed an additional lesion in the pons. From these findings, he was diagnosed as herpetic encephalitis involving the brainstem and the cerebellum, and acyclovir was administered. Although his initial symptoms and signs started to recover three weeks after admission, he newly developed complete flaccid paraplegia, dysuria and sensory disturbance with the spinal cord level of the 4th thoracic segment. The oligoclonal IgG bands were detected in the cerebrospinal fluid of the convalescent stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Acyclovir↗

Immunohistochemical, quantitative immunoelectron microscopic, and DNA cytofluorometric characterization of chemically induced rat malignant fibrous histiocytoma.

Malignant fibrous histiocytoma (MFH) was induced in rats by injection of 9,10-dimethyl-1,2-benzanthracene. Using cell suspensions prepared from the heterotransplanted nude mouse tumor as immunogen, a monoclonal antibody, (MAb), MEP-1, against fibroblastlike MFH tumor cells was generated. In the primary rat tumors and transplanted rat or nude mouse tumors, MEP-1 reacted specifically with the fibroblastlike cells but not with the histiocytelike cells or xanthoma cells. Anti-rat macrophage MAbs RM-1 and TRPM-3 did not stain the fibroblastlike cells, but both were reactive with the histiocytelike cells. Double stainings with both MEP-1 and RM-1 or TRPM-3 did not detect any double positive cells. Immunoelectron microscopy using these MAbs showed that the fibroblastlike cells were the major cell component of the primary and transplanted rat tumors and that their cell membrane was stained positively with MEP-1, but not for RM-1 or TRPM-3. By the double staining method using a MAb against prolyl 4-hydroxylase beta and MEP-1 or TRPM-3, this enzyme was demonstrated in MEP-1-positive cells but not in TRPM-3-positive cells. Results obtained by DNA cytofluorometry with 4,6-diamidino-2-phenylindole dihydrochloride staining or by the combined method of DNA cytofluorometry and indirect immunofluorescence, using MEP-1, RM-1, and TRPM-3, indicate that MEP-1-positive cells are neoplastic cells of rat MFH having proliferation activity. In the transplanted nude mouse tumors, no differentiation of MEP-1-positive rat tumor cells into histiocytelike cells was detected, and all histiocytelike cells were immunostained by F4/80 and most of them were positive for M5/114. These results suggest that fibroblastlike cells and intermediate cells are tumor cells of 9,10-dimethyl-1,2-benzanthracene-induced rat MFH showing differentiation toward fibroblasts and that histiocytelike cells are infiltrated macrophages.

9,10-Dimethyl-1,2-benzanthracene↗

[Results of the CCLSG high risk ALL 874 protocol in childhood acute lymphoblastic leukemia. Children's Cancer and Leukemia Study Group].

One hundred and eighty eight children with acute lymphoblastic leukemia (ALL) were treated in a Children's Cancer and Leukemia Study Group high-risk ALL 874 study from April, 1987 to September, 1991. These patients received a four-drug induction regimen followed by the early consolidation regimen, cranial irradiation at 6 months of remission and three years of continuation therapy with rotational administration of four drugs. The patients were randomized into two regimens. In regimen A, the consolidation chemotherapy consisted of the intermediate dose cytosine arabinoside (Ara-C), cyclophosphamide (CPM) plus 6MP, and in regimen B, it consisted of high-dose Ara-C plus CPM. Regimen A was given to 106 patients and 82 patients received regimen B. The complete remission induction rate for regimen A and B was 89.4% (93/104) and 98.7% (78/79), respectively. The 3-year event-free-survival (EFS) rate was 70.6% for regimen A, which was higher than the 56.7% for regimen B. The 3-year EFS rate was 44.4% for the 53 patients with an initial leukocyte count > or = 10 x 10(4)/microliters and 72.2% for 132 patients with a leukocyte count < 10 x 10(4)/microliter. We considered that Ara-C plus L-asp, added to the conventional high-risk ALL 811 protocol, improved the prognosis of the high risk ALL patients. However, further intensive chemotherapy was required for improvement of the outcome of the patients with hyperleukocytosis (> or = 10 x 10(4)/microliters).

Adolescent↗

Differences of draining lymph node cell proliferation among mice, rats and guinea pigs following exposure to metal allergens.

Contact sensitivities of three well known metal allergens (nickel sulfate, potassium dichromate and cobalt chloride) were examined using the local lymph node assay in CBA/N mice, F344 rats and Hartley guinea pigs. The effect of various species sera on lymph node cell (LNC) proliferation was also investigated. Exposure to potassium dichromate and cobalt chloride induced significant LNC proliferative responses in the three species. The LNC responses to potassium dichromate in the rats were higher than those in the mice and guinea pigs. Mice exhibited the highest response to cobalt chloride among the three species, whereas, exposure to nickel sulfate failed to induce a marked LNC proliferation. Increased draining lymph node weights and LNC numbers were also observed following exposure to the metal salts. However, these parameters were less sensitive compared with the LNC proliferative response. There was a large difference in the lymph node weight between individual guinea pigs. The [methyl-3H]thymidine incorporation into LNC of each species cultured in the presence of the homologous serum in vitro was lower than in the presence or absence of fetal calf serum. However, there was no significant difference in stimulation indices among the different culture conditions. The local lymph node assay may be performed in rats as well as in mice for the detection of metal allergens.

Allergens↗

Molecular cloning of the antibacterial protein of the giant African snail, Achatina fulica Férussac.

An expression cDNA library was constructed with poly(A)-rich RNA extracted from the collar of the giant African snail, Achatina fulica Férussac. A 1.9-kbp cDNA clone encoding a precursor of antibacterial glycoprotein of the snail, achacin, was isolated from the cDNA expression library. The cDNA sequence contains an open reading frame with 1593-nucleotide residues. The deduced amino acid sequence of this achacin precursor starts with a 29-residue leader peptide followed by a 502-residue mature peptide (56 kDa) with four possible N-glycosylation sites, Asn-Xaa-Ser or Asn-Xaa-Thr. The Northern-blot analysis proved that the achacin precursor was specifically expressed in the tissue of snail collar and processed to mature achacin. cDNA inserts encoding achacin precursor were subcloned into expression plasmids. Three kinds of expressed polypeptides were cross-reacted with rabbit antiserum raised against achacin. The largest polypeptide (M(r) 63,000) should be the achacin precursor.

Amino Acid Sequence↗

Resistance of the melibiose carrier to inhibition by the phosphotransferase system due to substitutions of amino acid residues in the carrier of Salmonella typhimurium.

The melibiose carrier of Salmonella typhimurium is under the control of the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS). We isolated mutants of the melibiose carrier that showed resistance to inhibition via the PTS. Growth of the mutants on melibiose was not inhibited by 2-deoxyglucose, a non-metabolizable substrate of the PTS, although growth of the parent strain was inhibited. Transport activity of the melibiose carrier in the mutants was fairly resistant to inhibition by 2-deoxyglucose, although the activity in the parent was sensitive to inhibition. We cloned the mutated melB gene that encodes the melibiose carrier, determined the nucleotide sequences, and identified replaced nucleotides. The mutations resulted in substitutions of Asp-438 with Tyr, Arg-441 with Ser, or Ile-445 with Asn. All of these residues are in the COOH-terminal region of the carrier. The secondary structure of this region is predicted to be an alpha-helix, and the mutated residues were on the same side of the helix. This region showed sequence similarity to a region of the MalK protein, in which substitution of amino acid residues also resulted in PTS-resistant mutants. Thus the COOH-terminal portion of the melibiose carrier is important for the interaction of dephosphorylated IIIGlc, which is an entity causing reversible inactivation of the carrier.

Amino Acid Sequence↗

[A survey of annual radiation dose for radiation workers from occupational and medical exposures in Kyushu].

This study was carried out to determine annual dose equivalents of exposure in workers exposed to medical radiation and occupational radiation in an enterprise associated with nuclear power plants. The results indicated that medical exposure is much higher than occupational exposure. Average annual effective dose equivalents for medical and occupational exposure were 4.0-7.5 mSv and 2.4-3.6 mSv, respectively. Individual occupational exposure limits have been well controlled and maintained at one-fifth of the dose limit for radiation workers (50 mSv/yr). On the other hand, medical exposure in the older workers of this enterprise has been increasing as a result of X-ray diagnosis with barium meal.

Adult↗

Synthesis of 5-deoxy-5-fluoro and 5-deoxy-5,5-difluoro derivatives of kanamycin B and its analogs. Study on structure-toxicity relationships.

5-Deoxy-5-fluoro- (1), 5.3'-dideoxy-5-fluoro- (2), and 5,3',4'-trideoxy-5-fluoro-kanamycin B (3) have been prepared by treatment of 5-epihydroxyl precursors (prepared by the Mitsunobu reaction) with DAST as the key step. 5,3'-Dideoxy-5,5-difluoro- (26) and 5,3',4'-trideoxy-5,5-difluoro-kanamycin B (27) were also prepared by treatment of the corresponding 5-oxo derivatives with DAST. These 5-deoxy-5-fluoro and 5-deoxy-5,5-difluoro derivatives showed markedly decreased toxicity as compared with the parent compounds.

Carbohydrate Sequence↗

Synthesis of 4'-deoxy-4'-fluorokanamycin A and B.

4'-Deoxy-4'-fluorokanamycins A (17) and B (25) have been prepared through fluorinative ring-opening of the D-galacto-3',4'-oxiranes (8 and 21) derived from kanamycin A and B with potassium hydrogenfluoride in ethane-1,2-diol. The mechanism of preponderant formation of the 4'-deoxy-4'-fluoro-D-gluco (9 and 22) over the 3'-deoxy-3'-fluoro-D-gulo derivatives was discussed. In the synthesis of 25, the unusual 3',6'-epimine (23) was the main product along with the 4'-deoxy-4'-fluoro derivative. The mechanism of this reaction is also discussed. Both 17 and 25 were active against resistant bacteria producing aminoglycoside-adenylylating enzymes for HO-4'.

Anti-Bacterial Agents↗

Study on fluorination of 2,3-dideoxy-2,3-(N-tosylepimino)-alpha-D-allopyranosides, and synthesis of 3'-deoxy-3'-fluorokanamycin B and 3',4'-dideoxy-3'-fluorokanamycin B.

Reaction of the structurally rigid methyl 2,3-dideoxy-4,6-O-isopropylidene-2,3-(N-tosylepimino)-alpha-D-a llopyranoside (6) with KHF2 in DMF at 150 degrees gave initially methyl 2,3-dideoxy-2-fluoro-4,6-O-isopropylidene-3-tosylamido-alpha-D-altrop yranoside (10) by N-tosylepimine-ring opening, and 10 was gradually converted into the stable methyl 2,3-dideoxy-3-fluoro-4,6-O-isopropylidene-2-tosylamido-alpha-D-glucopyra noside (11). A reversible mechanism involving 6 and 10 has been proposed. In the mobile methyl 2,3-dideoxy-2,3-(N-tosylepimino)-alpha-D-allopyranoside (7) and the corresponding 4,6-di-O-acetyl (8) and -di-O-methyl derivatives (9), reactions with KHF2 proceeded comparatively rapidly giving the corresponding 3-deoxy-3-fluoro-alpha-D-glucopyranosides as the major products. A slightly different reaction mechanism for the mobile compounds has been proposed. By application of this study, 3'-deoxy-3'-fluorokanamycin B was prepared by treatment of 4",6"-O-cyclohexylidene-2'-deamino-3'-deoxy-3'-epi-6'-N-methoxycarbonyl- 1,3, 3"-tri-N-tosyl-2',3'-(N-tosylepimino)kanamycin B (21) with KHF2 as the key reaction. 3',4'-Dideoxy-3'-fluorokanamycin B was also prepared. Both compounds were active against resistant bacteria producing 3'-modifying enzymes.

Carbohydrate Sequence↗