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Biomedical subjects

K Satoh

Publications and source records attributed to K Satoh.

At least 757 records · Page 42Linked to original sources
PubMed1992

Soybean protein isolate and soybean lectin inhibit iron absorption in rats.

Inhibitory effects of soybean protein isolate (SPI) and soybean lectin on the intestinal absorption of nonheme iron were investigated by in vivo studies in rats. Rats fed the SPI-based diet absorbed significantly less iron than did control rats fed the casein-based diet. Supplementing the SPI diets with 8% D-galactose significantly increased the incorporation of iron into liver ferritin, although D-galactose did not significantly increase iron absorption. Heat treatment of SPI significantly increased iron absorption. Ascorbate did not enhance iron absorption in rats fed the SPI-based diet. The presence of lectin in an aqueous extract of SPI was suggested by hemagglutination activity as well as by immunoreactivity with soybean lectin antibody. Soybean lectin introduced into ligated segments of the upper small intestine of rats inhibited ferrous iron absorption. This inhibitory effect, especially in the mucosal uptake, was significantly improved by addition of N-acetyl-D-galactosamine to soybean lectin. Soybean lectin had no effect on ferric iron absorption. Our results suggest that a portion of the reduction in iron absorption in rats fed SPI may be due to lectins.

Animals↗
PubMed1992

Correlation between anti-HBc titers and HBV DNA in blood units without detectable HBsAg.

Hepatitis B virus (HBV) DNA was tested for in 294 blood units which had antibody against hepatitis B core antigen (anti-HBc) as the isolated serological marker of HBV infection. After amplification by polymerase chain reaction, HBV DNA was detected in 12 (6.9%) of 175 units that were positive for anti-HBc with hemagglutination inhibition titers greater than or equal to 2(6), significantly more often than in none of 119 units with titers less than or equal to 2(5) (p less than 0.01). These results indicate that the exclusion of blood units with isolated high-titer anti-HBc would be effective for further decreasing the risk of posttransfusion hepatitis B.

Base Sequence↗
PubMed1992

Current views on panic disorder and its management in Japan: a national survey.

In a national random-sample survey, the views of 1,069 practicing clinicians, including internists, surgeons and psychiatrists, on panic disorder were surveyed by using a series of questionnaires. In spite of a high rate of clinical experience and agreements on the symptoms among clinicians, the nature of this disorder, such as a common descriptive diagnosis, and the preferred treatment have not been agreed upon by the Japanese medical community. Furthermore, respondents were questioned as to the preferred treatment for panic disorder, but no treatment was regarded as critical by a majority of clinicians. It is concluded that because of the high potential patient population with panic disorder, clinical research that will provide more adequate diagnosis and treatment for this disorder is necessary in Japan.

Adult↗
PubMed1992

Increased levels of blood platelet-activating factor (PAF) and PAF-like lipids in patients with ischemic stroke.

Levels of platelet-activating factor (PAF) in blood from patients with ischemic stroke were determined by radioimmunoassay (RIA). Using 2 ml of blood as a starting material, PAF was detected in 11 out of 17 stroke patients and 3 of 25 age-matched healthy controls. This implies that blood level of PAF is higher in stroke patients than in controls. Plasma levels of PAF-like lipid(s) (PAF-LL) were also estimated in the same subjects by a bioassay based on aggregation of human polymorphonuclear neutrophils. PAF-LL was detected in plasma samples of all subjects and the average values in patients and controls were 294 +/- 211 pg/ml and 140 +/- 122 pg/ml, respectively. There was a statistically significant difference between these two values (p less than 0.01). Separation of plasma lipids by HPLC gave a single peak in bioassay, which had the same elution volume as authentic PAF. When each fraction was subjected to RIA, the fractions corresponded to phosphatidylcholine (PC) or lysoPC also showed the immunoreactivity, however, the purification procedure using an octadecylsilica gel cartridge eliminated such cross-reacting compounds. We conclude that blood PAF is higher in patients with ischemic stroke than in healthy subjects. Besides, there may be bioactive phospholipid molecules other than PAF, which level in plasma is also higher in stroke patients.

Aged↗
PubMed1992

Platelet-activating factor acetylhydrolase activity in red blood cell-stroma from patients with cerebral thrombosis.

Platelet-activating factor (1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine, PAF) is a bioactive phospholipid and inactivated by a specific enzyme, PAF acetylhydrolase (PAF-AH). We have measured PAF-AH activity in red blood cells (RBCs) from patients with a history of cerebral thrombosis and age-matched healthy controls. The activities in 34 patients and 34 controls were 1.29 +/- 0.28 and 1.64 +/- 0.26 nmol/10(9) RBCs/min (or, 30.0 +/- 5.8 and 35.1 +/- 4.7 nmol/g protein/min) (mean +/- SD), respectively, and the difference was significant (p less than 0.001). In patients, RBC PAF-AH activity correlated positively with RBC filterability, an index of RBC deformability (r = +0.501, p less than 0.05). The RBC activity may play a role in scavenging oxidation products of membrane phospholipids. Lower RBC PAF-AH activity may predispose to ischemic diseases by disturbing microcirculatory behavior of the RBCs.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1992

Comparison of a polymerase chain reaction assay and a conventional microbiologic method for detection of methicillin-resistant Staphylococcus aureus.

The presence or absence of a methicillin resistance gene in 58 clinical isolates of Staphylococcus aureus was examined by the polymerase chain reaction (PCR) and Southern blot analyses. The results were analyzed in relation to those of the MIC assay of methicillin and oxacillin. PCR assay results were identical to those of Southern blot analysis of genomic DNA digested with HindIII (positive, 28 strains; negative, 30 strains). Among the 28 PCR-positive strains, 6 strains showed methicillin susceptibility by the conventional susceptibility test (MICs, less than or equal to 8 micrograms/ml). Culturing of the six strains with ceftizoxime led to an increase in the phenotypic level of resistance to methicillin and oxacillin, indicating that these strains should be classified as methicillin-resistant S. aureus (MRSA). The PCR assay was found to be a sensitive and reliable procedure for the rapid diagnosis of MRSA infection, even in cases in which the conventional MIC assay failed to detect MRSA.

Anti-Bacterial Agents↗
PubMed1992

Collagen deposition and the reversal of coronary reserve in cardiac hypertrophy.

The aim of this study was to clarify how collagen deposition or medial hypertrophy of the vascular wall affects the coronary dilator reserve in pressure-overloaded hearts and whether inhibition of collagen deposition reverses the abnormalities after relief of pressure overload. We used ascending aortic banding and debanding methods and superimposed beta-aminopropionitrile in some of the banded rats (50 mg/kg i.p., twice a day). Ten weeks of banding increased in vivo peak systolic left ventricular pressure and produced medial hypertrophy, an increase in collagen deposition in the myocardial and perivascular tissues, and myocardial hypertrophy in the banded group without beta-aminopropionitrile treatment. Superimposition of beta-aminopropionitrile treatment on banding inhibited the increase in collagen deposition. In the groups debanded after the 10-week banding period, both with and without beta-amino-propionitrile treatment, medial and myocardial hypertrophy regressed 4 weeks after debanding. We estimated coronary dilator reserve in Langendorff preparations perfused with modified Tyrode's solution containing oxygenated bovine red blood cells and serum albumin. The ratio of reactive peak flow after brief ischemia-to-resting flow decreased in both of the banded groups. After debanding, the ratio remained lower in the banded group without beta-aminopropionitrile treatment than in the control group. However, debanding in the group with beta-aminopropionitrile treatment increased the ratio to a level similar to that of the control group. Thus, in pressure-overloaded cardiac hypertrophy with coronary hypertension, coronary reserve seems to be determined by medial hypertrophy independently of collagen deposition, but collagen deposition plays an important role in the reversal of vasodilator reserve after relief of the overload.

Aminopropionitrile↗
PubMed1992

Platelet-activating factor acetylhydrolase in plasma lipoproteins from patients with ischemic stroke.

BACKGROUND AND PURPOSE: Platelet-activating factor is a potent bioactive phospholipid and may play an important role in occlusive vascular diseases. To assess the inactivation of this autacoid in plasma, we measured platelet-activating factor acetylhydrolase activity in plasma low density and high density lipoproteins from patients with ischemic stroke. METHODS: Low density and high density lipoproteins were separated by ultracentrifugation from plasma of 33 patients with cerebral thrombosis and 31 age-matched healthy control subjects, and platelet-activating factor acetylhydrolase activity in each fraction was assayed. RESULTS: The average values of platelet-activating factor acetylhydrolase activity in low density lipoprotein from patients and control subjects were 41 +/- 18 and 29 +/- 17 nmol/ml per minute, respectively, and the difference was statistically significant (p less than 0.01 U test). There was no difference in activity in high density lipoprotein between the two groups (16 +/- 11 versus 14 +/- 9 nmol/ml per minute, respectively). CONCLUSIONS: The increased plasma platelet-activating factor acetylhydrolase activity in stroke patients is primarily attributable to the increased binding to low density lipoprotein, and this increase may be an adaptation to the augmented generation of platelet-activating factor in ischemic stroke.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1992

A chimeric analog of human and salmon calcitonin eliminates antigenicity and reduces gastrointestinal disturbances.

The minimum region in salmon calcitonin (sCT) which induces antigenicity and gastrointestinal disturbances has been identified by examining the cross-reactivity of several sCT fragments and CT analogs with antisera from sCT-treated patients, and by examining inhibition of gastrointestinal motility of these sCT fragments and CT analogs in conscious dogs. Sixteen residues at the N-terminus of sCT comprised the minimum fragment capable of inducing both activities. Human CT (hCT) showed no antigenicity and a four-order weaker inhibition of gastrointestinal motility than sCT. Based on these data, we synthesized the human and salmon chimeric CT, ACT-15, in which the 16 N-terminal residues were those of hCT and the 16 C-terminal residues were those of sCT. ACT-15 had no cross-reactivity with the antisera and had almost the same weak gastrointestinal inhibition effect as hCT in dog and rat models. Nevertheless, it retained a hypocalcemic activity and an analgesic activity comparable to sCT. These results suggest that the amino acid residues in the N-terminal half of CT are responsible for the formation of antibodies and the induction of gastrointestinal disturbances, but may not influence calcium metabolism or analgesia. Clinical studies of ACT-15 will be needed to confirm this hypothesis.

Amino Acid Sequence↗
PubMed1992

[Effects of experimental Listeria monocytogenes infection on mice fed on lamprey or sardine oil prepared under high-temperature deodorization].

Fresh lamprey (F-La) or sardine (F-Sa) oil is known to contain a large amount of n-3 polyunsaturated fatty acids such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. When F-La or F-Sa was deodorized with steam at 280 degrees C under 1 mmHg for 1 h (H-La and H-Sa, respectively), the contents of EPA and DHA were reduced and unidentified peaks were newly detected by gas-liquid chromatography. To know the biological influences of these high-temperature deodorized oils, the sterilizing function of the macrophage against Listeria monocytogenes was investigated in male ddY mice fed H-La or H-Sa. One week feeding of H-La or H-Sa lowered the LD50 values of the bacteria injected intravenously. Numbers of the viable bacteria on the day 3 after intravenous injection were about 10 times higher in the liver and 5 times higher in the spleen of mice fed H-La or H-Sa as compared with those of the control group. These results suggest that the sterilizing function of fixed macrophages both in the liver and the spleen was suppressed in mice fed H-La or H-Sa.

Animals↗
PubMed1992

[The recent development and the present status of K+ channel opener].

The development of vasodilator drugs that open the K+ channels in blood vessels has been of great academic and practical interest. The discoveries of the ATP-sensitive K+ channel and the glibenclamide-sensitive K+ channel have promoted these interests. In relation to this channel, the cardioprotective effectiveness of a K+ channel opener (Aprikalim) in doses that did not change haemodynamics or collateral blood flow were demonstrated in infarct dog heart. The effects were antagonized by glibenclamide. Thus, ATP-sensitive K+ channels seem to play an important role in this effect. Clinical evaluations of the K+ channel openers are reviewed. The hypotensive effects of the drugs are well-recognized. At present, however, the clinical usefulness of K+ channel openers has not been accepted widely, because of their side-effects including reflex tachycardia, edema, flushing and headache. An approach to reduce these side-effects is critical if these K+ channel openers are to be used as good hypotensive drugs. The K+ channel opener nicorandil has been evaluated as a highly effective antianginal drug. It seems likely that the clinical benefits of nicorandil result from both its K+ channel opening properties and its ability to stimulate smooth muscle guanylate cyclase. Clinical data on the pure-selective K+ channel opener cromakalim (lemakalim) as an antianginal drug is limited. However, on the basis of the vasodilator profile of this drug, it is expected to be useful for this purpose. The application of K+ channel openers to treat other disorders such as bladder instability is limited because of its hypotensive action.

Animals↗
PubMed1992

Effects of semotiadil (SD-3211), a benzothiazine calcium antagonist, on blood pressure and atrioventricular conductivity in anesthetized dogs.

We investigated the effects of semotiadil (SD-3211), a novel calcium antagonist, on blood pressure and the atrioventricular (AV) conduction time and functional refractory period (FRP) of the AV conduction system (AV conductivity) in anesthetized open-chest dogs. The heart was electrically stimulated at a constant rate. In dogs with an intact nerve supply to the heart, i.v.-injections of semotiadil (0.03 to 0.3 mg/kg) produced a fall of blood pressure in a dose-dependent manner. AV conduction time and FRP were prolonged by rather higher doses (0.3 mg/kg), and second-degree AV block occurred only with the highest dose (1 mg/kg). In dogs with the nerve supply to the heart interrupted, the vasodepressor effects and suppressant effects of semotiadil on AV conductivity were slightly enhanced. The suppressant effects on AV conductivity became marked as pacing rates were increased. These results suggest that semotiadil at appropriate doses produces a vasodepressor effect without affecting AV conductivity even in the heart deprived of nervous control, e.g., the heart with beta-adrenoceptors blocked. The frequency-dependent suppressant effect on FRP of semotiadil is also noteworthy in the treatment of reentrant supraventricular tachycardia that involves the AV node.

Anesthesia↗
PubMed1992

ATP-sensitive K+ channels are gradually recruited in the vasodepressor response to adenosine in spinally-anesthetized dogs.

Vasodepressor mechanisms of adenosine were investigated in spinally-anesthetized dogs. An i.v.-infusion of adenosine (0.1-10 mumol/kg/min) caused a slowly developing and sustained decrease in blood pressure (BP). This vasodepression was antagonized by glibenclamide, a blocker of ATP-sensitive K+ (KATP) channels. On the other hand, a transient decrease in BP caused by a single bolus i.v.-injection of adenosine was not antagonized by glibenclamide in our previous study. These results suggested that the opening of KATP channels is gradually recruited in the vasodepressor mechanisms for adenosine-induced sustained vasodepression.

Adenosine↗
PubMed1992

[Effect of terazosin on lower urinary tract function in the male decerebrate dog].

The effect of terazosin on the lower urinary tract function was studied by combined recording of bladder and urethral pressures and external sphincter electromyogram in 8 male decerebrate dogs. Reflex micturitions were induced by bladder filling before and after terazosin. The statistical analysis was carried out on the urodynamic parameters. During the collecting phase, terazosin at doses of 10, 30 and 100 micrograms/kg produced a significant decrease in maximum urethral pressure in the dose dependent manner. Threshold pressure was significantly shown to decrease at doses of 30 and 100 micrograms/kg. In the urodynamic parameters of the emptying phase there was a significant decrease in maximum contraction pressure at 10 and 30 micrograms/kg, and in voided volume at 100 micrograms/kg. Terazosin seems to facilitate an initiation of the bladder contraction with a decrease in threshold pressure. In concludes that alpha 1 adrenergic activity seems to take an important role for the maintenance of the urethral pressure and to control the initiation of bladder contraction in modulation with threshold pressure.

Animals↗
PubMed1992

Specific expression of glutathione S-transferase Pi forms in (pre)neoplastic tissues: their properties and functions.

The detection of preneoplastic cells is very important for the analysis of carcinogenic processes and for developing strategies for prevention and treatment of cancer. We have been investigating enzyme alterations occurring during rat chemical hepatocarcinogenesis, especially to find more specific enzyme markers for preneoplastic hepatic lesions. We identified the placental form of glutathione S-transferase (GST-P; GST 7-7) as a new marker enzyme for preneoplastic hepatocytes. We also found human placental form, GST-pi, to be a possible tumor marker for various human tissues except liver. In this article, their properties and possible functions are reviewed on basis of our recent investigations. A peroxisomal enzyme, enoyl CoA hydratase, in also described as a possible negative marker for rat preneoplastic hepatic foci/nodules and hepatomas induced by peroxisome proliferators.

Animals↗
PubMed1992

Participation of serum albumin and LDL-cholesterol in impaired blood cell-filterability affected by white blood cells in patients with cerebral thrombosis.

We examined the effect of white blood cells (WBCs) on the red blood cell (RBC)-filterability, and the influence of plasma components on their interaction of their microcirculatory behaviour in cerebral thrombosis patients. Subjects studied were 20 patients with a history of cerebral thrombosis (60 +/- 4.7 years old) (mean +/- SD) and 28 healthy controls (59 +/- 5.4 years old). Filterability indices of RBC suspension (RFI) and suspension with RBCs plus WBCs (RWFI) were measured by the method of Nuclepore filtration. The values of RFI in patients and controls were 0.44 +/- 0.12 and 0.56 +/- 0.16 ml min-1 (mean +/- SD), and RWFIs were 0.33 +/- 0.092 and 0.40 +/- 0.11 ml min-1, respectively. The differences in both of these values between patients and controls were significant (p < or = 0.01 for RFI and p < or = 0.05 for RWFI, based on Student's t test, respectively). Both RFI and RWFI in bed-ridden patients were lower than those in the more active counterparts (p < or = 0.05, based on Student's t test). In patients, RFI and RWFI correlated positively with serum albumin (r = +0.515, p < 0.05; r = +0.533, p < 0.05, based on Student's t test, respectively). The net lowering effect of WBCs on RFI (RFI-RWFI) correlated positively with serum LDL-cholesterol in patients (r = +0.574, p < 0.01, based on Student's t test). WBCs play a significant role in reducing RFI, and its effect is related to the pathemas of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Cholesterol, LDL↗