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Biomedical subjects

K Yasuda

Publications and source records attributed to K Yasuda.

At least 757 records · Page 42Linked to original sources

Presence of platelet-activating factor-acetylhydrolase in milk.

Human milk contains numerous factors such as immunoglobulins, lactoferrin, lysozyme, macrophages, etc., which serve an immunoprotective role. Platelet-activating factor (PAF) is one of the most proinflammatory agents thus far described. PAF is metabolized to the biologically inactive lysoPAF by the enzyme PAF-acetylhydrolase (PAF-AH). In the present study we have demonstrated that PAF-AH activity is present in human milk. The activity was associated with aqueous phase and was not stimulated by the addition of bile salts or Ca2+. The activity of PAF-AH in human milk was not affected by the addition of propranolol or NaCl. PAF, and 1-acyl-2-acetyl-glycerophosphocholine were the only substrates cleaved by the enzyme. Based on these properties it is concluded that the milk PAF-AH is not the lipoprotein or bile salt-stimulated lipase known to be present in milk. Inhibitor studies revealed that the enzyme in human milk was the plasma type PAF-AH. The activity of PAF-AH was stable at pH 4.0 at 37 degrees C and the activity varied in milk samples obtained from various species. The enzyme was secreted by milk macrophages. The presence of PAF-AH in human milk may explain, in part, the beneficial effects of breast feeding in the prevention of necrotizing enterocolitis by inactivating the potent proinflammatory autacoid, PAF.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗

[Cervical epidural morphine and buprenorphine for postoperative pain relief after thoracic surgery--a comparative study in the same patients].

The effects of cervical epidural morphine and buprenorphine on postoperative pain were studied in 12 patients who received thoracic surgery twice. The patients who had received morphine 3 mg on the first operation were given buprenorphine 0.15 mg on the second operation, and the others received them vice versa. Morphine or buprenorphine was administered with 6 ml of 0.25% bupivacaine before skin incision. The duration of pain relief with morphine was longer (21.5 +/- 4.0 h) than with buprenorphine (13.9 +/- 7.8 h). The result of the questionnaires to the patients after operation shows that 10 patients (84%) were satisfied with morphine whereas only 6 patients (50%) were satisfied with buprenorphine. Seven patients preferred morphine to buprenorphine for postoperative analgesia, and the rest of the patients stated that analgesic effects were similar between the two. It seems that epidural morphine 3 mg may give more excellent postoperative pain relief after the thoracic surgery than epidural buprenorphine 0.15 mg.

Aged↗

[Relationship of Helicobacter pylori to chronological transition of endoscopic atrophic pattern].

The prevalence of Helicobacter pylori (HP) were studied in 117 subjects with no gross findings whose stomach age was equal to its chronological age. HP was detected by culture. The prevalence of HP significantly was higher in thirties and forties than other ages, and in C3 and O1 groups than other groups. Most of forties and fifties belonged to C3 or O1 groups. Histologically, HP infection was significantly frequent in the gastric mucosa with advancing inflammation. These findings suggest that HP infects in early middle age, causes the destruction and atrophy of gastric mucosa and disappears with ageing and chronological expansion of mucosal atrophy. We consider that HP infection may play a causative role of the aging process of the stomach.

Adult↗

[Fistula between iliac artery aneurysm and ureter: a case report and review of the literature].

We report a patient who developed a fistula between the right ureter and the right common iliac artery aneurysm. He had had replacement of a synthetic graft for abdominal aortic aneurysm sixteen years previously. The diagnosis was confirmed by angiography, retrograde pyelography and computed tomography. The fistula was treated by right nephroureterectomy and resection of right common iliac artery aneurysm. A brief description of the case is provided and the review of the literature is described.

Aged↗

[An acute axonal form of Guillain-Barré syndrome with autoantibody against ganglioside GD1b--a case report].

We reported a 3-year-old boy of an acute axonal form of Guillain-Barré syndrome (GBS) with autoantibody against GD1b ganglioside. A week after an episode of upper respiratory infection, he was hospitalized with a weakness in the lower extremities. Neurological examination revealed facial weakness, restricted extra-ocular movement, hyporeflexia and tetraparesis without any sensory impairment. CSF protein was elevated with normal cell count after the first week of symptoms. Electrophysiological studies demonstrated normal motor nerve conduction velocity and low M potential amplitude. He had been on a respirator for two months. Although he received plasmapheresis in the acute phase, sixteen month after the onset he continued to have distally dominant limb weakness with wasting. Thin-layer chromatogram with immunostaining revealed that serum IgG from this patient reacted with GD1b, but did not react with GM1. Enzyme-linked immunosorbent assay showed that anti-GD1b titer (IgG) decreased concurrently with the clinical improvement. There have been several reports of an acute axonal form of GBS with antibody to GM1. GD1b, as well as GM1, seems to be a target pathogenic antigen in motor axon disorders.

Autoantibodies↗

[Endoscopic sphincterotomy for lithotripsy (EST-L) of bile duct stones].

We performed EST-L for 555 patients with choledocholithiasis between 1981 and 1992. With the aid of conventional occlusion balloons and dormia-type baskets, calculi < or = 1.5 cm was extracted with relative ease. In patients with larger stone (> 1.5 cm), the mechanical lithotripter, extracorporeal shock wave lithotripsy (ESWL) and electrohydrolic lithotripsy were used for the lithotripsy. The overall success rate was 95%. Important early and late complications from these procedures occurred in 6.9% and 9.1% of all cases respectively. This result reveal that EST-L is safe and effective therapeutic procedures for choledocholithiasis. We would recommend EST-L is adopted as an initial measure to remove common bile duct stones.

Bile Duct Diseases↗

[Usefulness of polymerase chain reaction (PCR) technique in making early diagnosis and treatment of cytomegalovirus and Pneumocystis carinii-pneumonia in patients with hematological neoplasms].

Recently, the incidence of opportunistic infections in patients with hematological neoplasms has been markedly increasing. However, early and definitive diagnosis and treatment of these infections remain difficult. In this study, we report three patients, a 47-year-old female with ATL, a 54-year-old female with CML and a 65-year-old female with ATL. All these cases were complicated with pneumonia caused by Pneumocystis carinii (Pc) or cytomegalovirus (CMV). They were successfully treated with sulfamethoxazole/trimethoprim or ganciclovir after detection of the respective microorganisms from sputum samples in the early stage of the infections by polymerase chain reaction (PCR) method. The above clinical evidence demonstrated the PCR technique to be a rapid and sensitive diagnostic procedure for the detection of Pc or CMV and to be helpful for the early initiation of appropriate treatment of the infections in patients with hematological neoplasms.

Aged↗

[Correlation of myocardial temperature, intramyocardial pH, and myocardial electrical activity during hyperkalemic hypothermic cardioplegic arrest to functional recovery after reperfusion].

We estimated the correlation of myocardial temperature, intramyocardial pH, and myocardial electrical activity (MEA) during hyperkalemic hypothermic cardioplegic arrest to functional recovery after reperfusion to assess those parameters as intra-operative on-line assessment of myocardial preservation during cardiac operation. Twenty dogs underwent cardiopulmonary bypass at 30 degrees C. Cardiac function was evaluated before and after two hours ascending aortic cross-clamping. The dogs were divided into four groups according to cardiac preservation methods employed. Group I (n = 6): 4 degrees C hyperkalemic crystalloid cardioplegic solution was delivered antegradely through the aorta every 30 minutes without topical cooling. Group II (n = 4): total volume of cardioplegic solution same as Group I was delivered only once without topical cooling. Group III (n = 5): cardioplegic solution same as Group I with lidocaine (100 mg/l) was delivered every 30 minutes without topical cooling. Group IV (n = 5): cardioplegic solution same as Group I was delivered every 30 minutes with topical cooling. Hearts at less than 8 degrees C during aortic cross-clamping (Group I) revealed better functional recovery (72 +/- 21%) than those over 15 degrees C (Group II-IV, 28 +/- 30%). There was no significant correlation between intramyocardial pH changes during aortic cross-clamping and functional recovery after reperfusion (R = -.2257). During aortic cross-clamping, the occurrence of MEA which was obtained directly from the electrode inserted into left ventricular anterior free wall (direct MEA) was observed in all cases. However the myocardial activities which were identified by direct MEA were not necessarily observed visually or by routine electrocardiogram.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗

[Antiinflammatory effects of the betamethasone sodium phosphate enema on carrageenan induced colitis in the rabbit].

The effect of the betamethasone sodium phosphate (BSP) enema on the colonic mucosal lesions in the carrageenan induced colitis (rabbit) was examined laboratory and histologically. The effect of drugs were evaluated by the changes of body weight, fecal occult blood, blood analysis, and histological examinations. Fecal occult blood were highly positive in the physiological saline treated but less positive in the BSP groups. In the blood analysis, anemia was not detected in both groups. Histological findings such as the defect of superficial epithelium, crypt abscess, inflammatory cell infiltration, atrophic changes, defect of muscularis mucosae, goblet cell depletion, goblet cell depletion, ulcer formation, and edematous change were scored to evaluate the colonic mucosal lesions. These scores (Mean +/- S.D.) were 4.4 +/- 1.96, 7.7 +/- 3.67 for BSP, physiological saline groups respectively. From these results, BSP enema showed an antiulcerative effect on the entire colonic lesions in the carrageenan induced colitis in the rabbit.

Animals↗

[Recommended dietary allowances of fat-soluble vitamins].

In Japan the recommended dietary allowances (RDAs) of vitamin A for adult male is calculated at 600 micrograms RE, on the data in a human vitamin A depletion-repletion study that minimum requirement for maintenance of a adequate retinol storage at liver is 6.6 micrograms/kg body weight/day. By contrast, it is estimated at 1,000 micrograms RE in U.S., on the basis of a study that minimum requirement for prevention of follicular hyperkeratosis, not impaired dark adaptation, is 910 micrograms RE/day in most adult men. On fourth edition of Japanese RDAs in 1989, the estimated safe and adequate daily dietary intake of vitamin E for adult male was established at 8 mg alpha TE, on the data that the average of unsaturated fatty acid intake was 14.3 g/day and a desirable [vitamin E (mg) to PUFA (g)] ratio of 0.4, whereas the 8-10th editions of U.S. RDAs of vitamin E for adult male had been estimated at 10 mg alpha TE. And the RDAs of other fat-soluble vitamins were discussed on the differences between Japan and other countries.

Adult↗

Kinetic analysis of hepatobiliary transport of organic anions in Eisai hyperbilirubinemic mutant rats.

The hepatobiliary transport of nonmetabolizable organic anions [cefodizime, dibromosulfophthalein, and indocyanine green (ICG)] was kinetically analyzed in Eisai hyperbilirubinemic rats (EHBR; Sprague-Dawley-derived mutant rats with conjugated hyperbilirubinemia). In EHBR, the biliary excretion of these anions was remarkably impaired, whereas the alteration in initial plasma disappearance was minimal. The kinetic analysis of the disposition of these ligands revealed 1) that the transport rate via bile canalicular membrane was severely impaired in EHBR for cefodizime and dibromosulfophthalein and 2) that the intracellular transport rate of ICG was decreased in EHBR, which contributed more than the decrease in the canalicular membrane transport to the net reduction of the excretion rate of ICG in EHBR. The latter finding was also supported by the in vitro results; the binding of ICG to ligandin(s) in EHBR was less extensive compared with that in normal rats, resulting in the higher distribution of ICG to organelle. Because the ligand molecules bound to organelle diffuse within the cells much more slowly than the molecules in the cytosol, the higher distribution of ICG to organelle in EHBR results in the reduction in the intracellular transport rate. These results indicate that the differential impairment mechanisms can be proposed for the excretion of organic anions: One is the impairment in the transport rate across the canalicular membrane, the other is the impairment in the intracellular transport rate.

Animals↗

[Surgical aspects of automatic implantable cardioverter defibrillator (AICD) in patients with life-threatening ventricular tachyarrhythmias].

Implantations of automatic implantable cardioverter defibrillator were performed in five patients with life-threatening ventricular tachyarrhythmias. Preoperative diagnoses of arrhythmias were sustained ventricular tachycardia (VT) in two cases, ventricular fibrillation (VF) in two cases and sustained VT+VF in one case. Four of five cases had basic diseases respectively (broad anterior myocardial infarction, dilated cardiomyopathy, arrhythmogenic right ventricular dysplasia, hypertrophic cardiomyopathy), and the other case was idiopathic. Preoperative CTR were 43-65% (mean 57.4%) and left ventricular ejection fraction were 26-76% (mean 51.2%). Implantation of AICD was indicated for patients who survived circulatory arrest or life-threatening VT. Median sternotomy (3) or left antero-lateral thoracotomy (2) were performed for implantation of large-small patch electrodes for defibrillation. AICD generators were implanted in the pocket under abdominal rectal muscle in all cases. Postoperatively myocardial insufficiency, pericarditis, pleuritis occurred in three cases respectively. In the follow-up periods (2-25 months, mean 13 months), AICD worked effectively in two patients with spontaneous VT (6 months, 1 year after operation) and no cardiac death was experienced. We concluded that AICD system is effective for the life-threatening ventricular tachyarrhythmias, although the further estimation in longer follow-up periods are warranted.

Adult↗

Cloning of a novel somatostatin receptor, SSTR3, coupled to adenylylcyclase.

The gene encoding a novel mouse somatostatin receptor termed mSSTR3 was isolated and characterized. The sequence of mSSTR3 shows 46 and 47% identity with mSSTR1 and mSSTR2, respectively. mSSTR3 binds somatostatin-14 and somatostatin-28 with high affinity, but shows very low affinity for the somatostatin analogs MK-678 and SMS-201-995. In addition, mSSTR3 is coupled to pertussis toxin-sensitive G proteins and mediates somatostatin inhibition of forskolin-stimulated and dopamine D1 receptor-stimulated cAMP formation, indicating that it is coupled to adenylylcyclase. The pharmacological properties of mSSTR3 and its ability to couple with adenylylcyclase distinguish SSTR3 from the other cloned somatostatin receptors and indicates that it mediates biological functions different from SSTR1 or SSTR2. In situ hybridization indicates that SSTR3 mRNA is widely distributed in the mouse brain, and its expression in the nucleus of the lateral olfactory tract and in the piriform cortex, the primary olfactory cortex in the rodent brain, suggests that SSTR3 may participate in the processing and modulation of primary sensory information.

Adenylyl Cyclases↗

The cooperative interaction between two motifs of an enhancer element of the chicken alpha A-crystallin gene, alpha CE1 and alpha CE2, confers lens-specific expression.

An 84 bp element located between nucleotides -162 and -79 of the chicken alpha A-crystallin gene exhibits lens-specific enhancer activity. Transient transfection experiments using 5' deletion and linker scanner mutants has indicated that the 84 bp enhancer element is composed of three motifs, alpha CE1 (-162 to -134), alpha CE3 (-135 to -121) and alpha CE2 (-119 to -99). Neither alpha CE1 or alpha CE3 motif alone can exhibit enhancer activity even when trimerized, whereas together they can direct some degree of lens-specific expression. alpha CE2 alone shows low transcriptional activity when trimerized. A combination of alpha CE1 with alpha CE2 exerts full lens-specific enhancer activity comparable with that of the 84 bp enhancer element, indicating that alpha CE1 and alpha CE2 motifs are sufficient to confer lens-specific expression. Transcriptional activation by these two motifs from a distance required the additional presence of either or both motifs adjacent to the beta-actin basal promoter. Gel shift experiments indicated that the alpha CE1, alpha CE2 and alpha CE3 motifs specifically bind nuclear proteins. alpha CE1 binds a protein predominantly present in lens cells, whereas alpha CE2- and alpha CE3-binding proteins differ between lens and lung cells. Mutations within the alpha CE1 and alpha CE2 motifs that failed to bind nuclear factors in vitro resulted in loss of transcriptional activation, indicating that these nuclear factors play a key role in controlling lens-specific expression.

Animals↗

Localization of pancreatic endocrine tumors by endoscopic ultrasonography.

BACKGROUND: After a pancreatic endocrine tumor has been diagnosed on the basis of clinical signs and the results of laboratory tests, localization of the tumor by the usual imaging procedures fails in as many as 40 to 60 percent of patients. Endoscopic ultrasonography, a sensitive test for small carcinomas of the pancreas, might also be useful in patients with endocrine tumors of the pancreas that cannot be localized by conventional methods. METHODS: We studied 37 patients later shown to have 39 endocrine tumors of the pancreas who had negative results on transabdominal ultrasonography and CT. All the patients underwent endoscopic ultrasonography, and 22 also underwent selective angiography. All the tumors were confirmed by surgical excision and immunohistologic examination; they consisted of 31 insulinomas, 7 gastrinomas, and 1 glucagonoma, 0.5 to 2.5 cm (mean, 1.4 cm) in diameter. All but one of the patients were cured of their disease, as ascertained by at least six months of clinical and laboratory follow-up. RESULTS: Using endoscopic ultrasonography, we were able to localize 32 of the 39 tumors (sensitivity, 82 percent); no tumor was incorrectly localized. The size of the tumors was very similar (within 2 mm) to that predicted by endoscopic ultrasonography. Among the 22 patients who underwent both angiography and endoscopic ultrasonography, ultrasonography was significantly more sensitive than angiography for tumor localization (sensitivity, 82 percent vs. 27 percent). Among 19 control patients without pancreatic endocrine tumors, endoscopic ultrasonography was negative in 18 (specificity, 95 percent). CONCLUSIONS: Endoscopic ultrasonography is a highly sensitive and specific procedure for the localization of pancreatic endocrine tumors. It should be considered for the preoperative localization of such tumors once the clinical and laboratory diagnosis has been established.

Adenoma, Islet Cell↗

Gly145 to Arg substitution in HBs antigen of immune escape mutant of hepatitis B virus.

A Japanese child born to an HBeAg-positive carrier mother received anti-HBs immunoglobulins and a plasma-derived HBs vaccine with a poor anti-HBs-antibody response. The child, who is now 3 years old, is presently suffering from chronic hepatitis with unusual serological findings that are positive for HBsAg, anti-HBs and HBeAg, since being infected with a measles virus at 12 months of age. The nucleotide sequences of the S region of HBV DNA obtained from the patient, the mother and an HBeAg-positive brother were completely identical except for one nucleotide at position 587 (mother and brother: guanosine, patient: adenosine), giving an amino acid change: Gly - greater than Arg at position 145 of the major HBs protein.

Amino Acid Sequence↗