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Biomedical subjects

M Otsuka

Publications and source records attributed to M Otsuka.

At least 361 records · Page 20Linked to original sources
PubMed1989

Evaluation of the significance of "redistribution" in I-123 IMP SPECT in cerebrovascular disorders--a comparative study with PET.

We evaluated the significance of redistribution in 123I-IMP SPECT study using PET. Twelve lesions in ten patients were selected. These lesions were classified into the following three groups; ischemia, infarction of subacute phase and infarction of chronic phase. All lesions with ischemia or subacute infarction showed good or moderate redistribution. Three of four lesions with chronic infarction showed no redistribution. The mean values of rCBF and rCMRO2 were highest in the lesions with good redistribution, but there was no differences in rOEF with the degree of redistribution. In conclusion, the tissue with good redistribution is not always viable and it was impossible to predict a region with increased rOEF by redistribution alone.

Adult↗
PubMed1989

Cerebral blood flow, oxygen and glucose metabolism with PET in progressive supranuclear palsy.

Cerebral blood flow, cerebral oxygen metabolic rate and cerebral glucose metabolic rate were measured with positron emission tomography (PET) in four patients with progressive supranuclear palsy (PSP). Decreased blood flow and hypometabolism of oxygen and glucose were found in both subcortical and cortical regions, particularly in the striatum including the head of the caudate nucleus and the frontal cortex. The coupling between blood flow and metabolism was preserved even in the regions which showed decreased blood flow and hypometabolism. These findings indicated the hypofunction, as revealed by decreased blood flow and hypometabolism on PET, both in the striatum and the frontal cortex, and which may underlie the pathophysiological mechanism of motor and mental disturbance in PSP.

Adult↗
PubMed1989

Cleavage action of a trypsin-like protease from Bacteroides gingivalis 381 on reduced egg-white lysozyme.

Soluble reduced lysozyme was extensively digested by a trypsin-like protease purified from the culture supernatant of the bacterium. The digestion peptides were separated and purified by reversed-phase high-performance liquid chromatography, and were subjected to amino acid analysis. The fragments were identified by their amino acid composition, and the cleavage sites in the lysozyme chain were determined. Like mammalian trypsin, the enzyme from B. gingivalis split peptide bonds non-specifically at carboxyl sides of internal arginine and lysine residues, but the lysine present at the amino terminus of the lysozyme chain was not released. In addition, the enzyme cleaved the peptide linkage at the amino side of lysine and bonds between leucine-glycine, alanine-leucine and leucine-serine. Thus the trypsin-like protease from B. gingivalis has some cleavage actions on lysozyme different from those of mammalian trypsin.

Amino Acid Sequence↗
PubMed1989

Consumption of raw potato starch alters intestinal function and colonic cell proliferation in the rat.

Raw potato starch (RPS) may escape complete digestion to enter the colon and produce alterations in colonic function, while cooked potato starch (CPS) is nearly completely digested in the rat small intestine. Effects of RPS and CPS on colonic function [fecal weight, transmit time and thymidine kinase (TK) activity (a marker for cell proliferation)] were contrasted in a 6-wk feeding study. Male F344 rats consumed either dextrose/sucrose (DS; control), 30% CPS or 30% RPS diet. RPS feeding resulted in a 3-fold increase in fecal weight and a 30% prolongation in transit time, as well as elevated levels of colonic mucosal total protein (50%) and TK activity (4- to 7-fold) compared to DS-fed rats. A second study revealed normal large intestinal histology in rats fed CPS or RPS, with elongated colonic crypts (33% increased over CPS) in group RPS. Large intestinal contents were heavier in group RPS than in group CPS. These studies demonstrate that RPS feeding significantly enhances fecal weight yet prolongs total gastrointestinal transit time. Enhanced colonic TK and elongated colonic crypts suggest that RPS stimulates colonic mucosal growth.

Analysis of Variance↗
PubMed1989

Influence of meal distribution of wheat bran on fecal bulk, gastrointestinal transit time and colonic thymidine kinase activity in the rat.

Male Fischer 344 rats were fed either fiber-free (FF), continuous 10% wheat bran (CWB) or intermittent 50% wheat bran (IWB) diets for 6 wk to investigate possible alterations in physiological effects associated with colon cancer (fecal bulk, transit time, colonic cell proliferation) induced by meal distribution of the bran. The FF and CWB groups consumed unvaried diets throughout the day. The IWB group consumed two consecutive meals of a 50% bran diet for a total of 4 hr each day followed by a fiber-free diet for the remaining hours of the day. Similar daily quantities of bran were consumed in the CWB and IWB groups. Dry fecal weights rose significantly and transit times declined in both bran-fed groups independent of the meal distribution of bran. Colonic cell proliferation (estimated by thymidine kinase activity) was similar in all groups. The results suggest that these physiological effects of wheat bran are independent of the meal distribution of the bran.

Animals↗
PubMed1989

Positron emission tomography in epilepsy: correlative study.

Positron emission tomography (PET) was performed with the 18F-fluoro-deoxy-glucose method on 29 patients with epilepsy (generalized epilepsy, 4; partial epilepsy, 24; undetermined type, 1). The subjects were restricted to patients with epilepsy without focal abnormality on X-CT. All the patients with generalized epilepsy showed a normal pattern on PET. Fourteen out of the 24 patients with partial epilepsy and the 1 with epilepsy of undetermined type showed focal hypometabolism on PET. The hypometabolic zone was localized in areas including the temporal cortex in 11 patients, frontal in 2 and thalamus in 1. The location of hypometabolic zone and that of interictal paroxysmal activity on EEG were well correlated in most patients. The patients with poorly-controlled seizure showed a higher incidence of PET abnormality (12 out of 13) than those with well-controlled seizures (2 out of 11). The incidence of abnormality on PET and MRI and the location of both abnormality were not necessarily coincident. These results indicated that the PET examination in epilepsy provides valuable information about the location of epileptic focus, and that the findings on PET in patients with partial epilepsy may be one of the good indicators about the intractability of partial epilepsy, and that PET and MRI provide complementary information in the diagnosis of epilepsy.

Blood Glucose↗
PubMed1989

Pharmacological properties of a C-fibre response evoked by saphenous nerve stimulation in an isolated spinal cord-nerve preparation of the newborn rat.

1. An isolated spinal cord-peripheral nerve preparation of the newborn rat was developed. In this preparation it is possible to record spinal reflexes from a lumbar ventral root in response to stimulation of the ipsilateral saphenous or obturator nerve. 2. Single shock, weak intensity stimulation of the saphenous nerve induced a fast conducted compound action potential in the L3 dorsal root and a fast depolarizing response in the ipsilateral L3 ventral root. As a stronger stimulus was applied to the saphenous nerve, a slowly conducted compound action potential appeared in the dorsal root and a slow depolarizing ventral root potential (v.r.p.) in the L3 ventral root. 3. Single shock stimulation of the obturator nerve induced a rapidly conducted compound action potential in the L3 dorsal root and monosynaptic and polysynaptic reflexes, with a fast time course, in the ipsilateral L3 ventral root. 4. The slow v.r.p. evoked by saphenous nerve stimulation was depressed by the tachykinin antagonist, [D-Arg1, D-Trp7,9, Leu11] substance P (spantide), 4-16 microM. The response recovered its original shape and size 30-60 min after the removal of this antagonist. 5. The saphenous nerve-evoked slow v.r.p. was depressed by [Met5] enkephalin (0.1-1 microM), dynorphin (1-13)(0.2 microM) and morphine (1-2 microM), and these effects were reversed by naloxone (1 microM). 6. Two endogenous peptides, galanin (1-2 microM) and somatostatin (1-2.5 microM), inhibited the slow v.r.p. evoked by saphenous nerve stimulation, whereas another endogenous peptide, calcitonin gene-related peptide (0.1-0.5 microM), potentiated the slow v.r.p. The slow v.r.p. was also inhibited by gamma-aminobutyric acid (GABA, 20 microM) and muscimol (0.2 microM), and their effects were antagonized by bicuculline (1 microM). 7. The present results suggest that substance P and neurokinin A are involved in the saphenous nerve-evoked C-fibre response in the spinal cord of the newborn rat.

Animals↗
PubMed1989

Effects of the mechanical energy of multi-tableting compression on the polymorphic transformations of chlorpropamide.

The effects of the mechanical energy of tableting compression on the polymorphic transformation of chlorpropamide have been examined. A single-punch eccentric tableting machine with a load cell and a non-contact displacement transducer were used to measure compression stress, distance and energy. An amount of 100 mg of the stable form A or the meta-stable form C of the drug was loaded into the press and the sample compressed with a compression stress of 196 MPa at room temperature (20 degrees C). The compression cycle was repeated from 1 to 30 times. The powder X-ray diffraction profiles of the deagglomerated compressed sample powder were measured to calculate the polymorphic content. The results on forms A and C suggested that both forms were transformed into each other in the solid state by mechanical energy during tableting. The contents of forms A and C reached equilibrium at a constant value above 100 J g-1 of compression energy after more than 10 cycles. After 30 tableting cycles of forms A and C, the contents of A, C and the non-crystalline solid were almost constant at about 45, 25 and 30%, respectively. The compression energies were estimated to be about 500-600 J g-1. From the results it seems that the transformation mechanism of forms A and C during tableting were as follows. The crystal form of A or C was converted to a non-crystalline solid by the mechanical energy, and the solid was then transformed into form A or C.

Chemical Phenomena↗
PubMed1989

Adult T cell leukemia in hemodialysis patients from the Kagoshima district, an area in which human T cell leukemia virus type I is highly endemic.

We report 2 cases of adult T cell leukemia (ATL) from hemodialysis (HD) patients with chronic renal failure (CRF) in the Kagoshima district, an endemic area of human T cell leukemia virus type I(HTLV-I) in Japan. The positivity of antibodies to ATL-associated antigen(anti-ATLA) in HD patients, regardless of whether or not blood transfusions were given, has been higher than in healthy persons in the district (p less than 0.01). ATL is considered to break out from HTLV-I carriers. Further study should be conducted to clarify the relationship between HTLV-I infection and CRF, and moreover, attention should be directed not only to treatment of HD but accompanying ATL as well, particularly in HTLV-I-endemic areas.

Aged↗
PubMed1989

An improved high-performance liquid chromatographic assay for the determination of free and esterified carnitine in animal tissues.

A high-performance liquid chromatographic procedure for the determination of carnitine that is converted to coenzyme A(CoA) stoichiometrically by carnitine acetyltransferase is described. The chromatographic separation was accomplished by using Unisil QC8 column and a mixture of 190 mM KH2PO4 and methanol (87:13, v/v) as eluent. The present method is rapid, sensitive, and can be used for the routine analysis of animal tissues and plasma.

Acetyltransferases↗
PubMed1989

Metabolic fate of the new anti-ulcer drug enprostil in animals. 2nd communication: whole-body autoradiographic distribution of [3H]-enprostil in rats.

The distribution of radioactivity was studied by whole-body autoradiography in rats after oral or intravenous administration of [3H]-enprostil ((+/-)-11a-15a-dihydroxy-9-oxo-16-phenoxy-17,18,19,20-tetranorp r osta-4,5,13(t)- trienoic acid methyl ester, TA-84135) at a dose of 23 micrograms/kg. After oral administration to male rats, radioactivity in almost all the tissues and organs reached a peak within 15 min to 1 h. The highest levels of radioactivity were found in the contents of the stomach and intestine. High levels of radioactivity were also observed in the liver and kidney, and moderate levels were found in the lung, blood, dental pulp and the walls of the stomach. Radioactivity was the lowest in the skeletal muscle, testis, eye and brain. After reaching peak levels, radioactivity in the body decreased gradually, and it was detected only in the excretory organs at 24 h after drug administration. The distribution pattern after the intravenous dose was essentially similar to that after oral administration. The distribution profile of radioactivity in non-pregnant female rats after an oral dose was similar to that in male rats. Placental transfer and excretion in milk of radioactivity was slight. When the affinity of this compound to the melanin-containing tissues such as the uveal tract of the eye and the hair follicle was examined using pigmented rats, no tendency to retention of radioactivity in these tissues was observed.

Administration, Oral↗
PubMed1989

Metabolic fate of the new anti-ulcer drug enprostil in animals. 3rd communication: tissue accumulation after consecutive oral administration of [3H]-enprostil in rats.

Accumulation characteristics of radioactivity in organs and tissues were investigated after oral administration of [3H]-enprostil ((+/-)-11a,15a-dihydroxy-9-oxo-16-phenoxy-17,18,19,20-tetranorp r osta-4,5,13(t)- trienoic acid methyl ester, TA-84135) to male rats once a day (20 micrograms/kg/d) for 1, 7 or 14 days. [3H]-Enprostil was found to be partially metabolized in vivo to volatile tritium (3H2O). The ratios of volatile tritium to total radioactivity in plasma increased with repeated administration of [3H]-enprostil and the levels of volatile tritium were almost equilibrated within 7 days of drug administration. The formation rate of volatile tritium was estimated to be 1-2% of the single dose. The blood levels of non-volatile radioactivity at 1 h after each daily dosing were nearly constant. The levels at 24 h, however, increased with repeated dosing. The levels of non-volatile radioactivity in most tissues at 1 h after the multiple administration (7 and 14 times) were higher than those after the single dose. At 24 h, levels were noticeable after multiple dosing even in the tissues in which levels below the detection limit were found after the single dose. From the comparison of the multiple-dose groups, the levels in most tissues attained steady state within 7 times dosing. The daily excretions of radioactivity in the urine, feces and expired air were constant throughout the period of consecutive administration. The total recovery of administered dose was 92%, which was similar to that achieved in the single-dosing group. As described above, the retention of non-volatile radioactivity was observed in most tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1989

Metabolic fate of the new anti-ulcer drug enprostil in animals. 4th communication: effect on hepatic drug metabolizing enzyme system in rats.

Effects of multiple oral administration of enprostil ((+/-)-11 alpha,15 alpha-dihydroxy-9-oxo-16-phenoxy-17,18,19,20-tetranorprosta- 4,5,13(t)-trienoic acid methyl ester, TA 84135) (20 micrograms/kg/d) and its solvent propylene carbonate (PC, 100 microliters/kg/d) on body weight gain, liver weight, hepatic drug metabolizing enzyme system and hexobarbital sleeping time were investigated in male rats during a 14-day period. Cytochrome P-450 content (as compared to the untreated control) and cytochrome b5 content (as compared to PC treated group) were slightly, but significantly, reduced in the group given a single oral dose of enprostil. However, these slight reductions were not augmented significantly by repeated administrations of enprostil. Slight but significant increase in microsomal protein content was observed in the group given 14 oral doses of enprostil and PC. Enprostil did not affect the other indicators used to evaluate the status of the hepatic drug metabolizing enzyme system. Additionally, single or multiple oral doses of enprostil or PC showed no effect on the hexobarbital-induced sleeping time. It therefore may be safely concluded that multiple oral administration, both of enprostil and of PC, has very little effect on drug metabolizing enzyme inducing or inhibiting activity in rats.

Animals↗
PubMed1989

[Clinicopathological studies of the gastrointestinal tract in adult T-cell leukemia patients].

We analysed the digestive symptoms and the gastrointestinal (GI) tract lesions in 61 patients with adult T cell leukemia (ATL). Digestive symptoms were found in 36 patients (59.0%) at the onset of leukemia, and in 45 patients (73.8%) at the first medical examination. X-ray examination of the GI tract was made in 22 patients, and abnormal stomach mucosa patterns were found in 20 patients (90.9%). Endoscopic examination of the GI tract was carried out in 18 patients, and it revealed that most of the stomach mucosa was accompanied by edema and redness. Erosions and ulcers also were found in many patients. A granular shadow, which was noted during the x-ray examination, could not be confirmed by endoscopy. A pathological examination of biopsied specimens was made in 13 patients, and infiltration of leukemic cells into the stomach was observed in 10 of the 13 cases. These findings suggest that leukemic infiltration into digestive tracts is related to the development of digestive symptoms in ATL patients.

Adult↗