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Biomedical subjects

Y Wada

Publications and source records attributed to Y Wada.

At least 739 records · Page 41Linked to original sources
PubMed1992

Molecular genetics of the yeast vacuolar H(+)-ATPase.

The yeast vacuolar proton-translocating ATPase was discovered in 1981 as the first member of the V-ATPases, which are now known to be ubiquitously distributed in eukaryotic vacuo-lysosomal organelles and archaebacteria. Nine VMA genes that are indispensable for expression of vacuolar ATPase activity have been identified in the yeast Saccharomyces cerevisiae. VMA1, VMA2, VMA3, VMA5 and VMA6 were cloned and characterized on the basis of partial amino acid sequences determined with the purified subunits. Genetic and biochemical studies of the yeast Pet-cls mutants have demonstrated that they are related to vma defects. Based on this evidence, VMA11 (CLS9), VMA12 (CLS10) and VMA13 (CLS11) were isolated from a yeast genomic DNA library by complementation of the vma11, vma12 and vma13 mutations, respectively. This article summarizes currently available information on the VMA genes and the molecular biological functions of the VMA gene products.

Adenosine Triphosphatases↗
PubMed1992

Induction of dyspnea by aerosol of endothelin-1/histamine or/methacholine in the conscious guinea pig.

The inhalation of aerosol of endothelin-1 (ET-1) induced dyspneal behavior in conscious guinea pigs pretreated with histamine or methacholine inhalation, although it was not observed by the inhalation of ET-1 alone. The dyspneal response to the inhalation of ET-1/histamine was potently inhibited by indomethacin, but it was not affected by nifedipine or diphenhydramine.

Administration, Inhalation↗
PubMed1992

Effects of calphobindin II (annexin VI) on procoagulant and anticoagulant activities of cultured endothelial cells.

Effects of human placental calphobindin II (CPB-II) on the protein C activation and prothrombin activation on the cell surface of cultured calf pulmonary arterial endothelial cells have been investigated. CPB-II inhibited thrombin generation by factor Xa bound to the surface of the cultured endothelial cells in a dose-dependent manner. The amount (IC50) of CPB-II causing the inhibition at 50% was estimated to be approximately 10 nM. CPB-II was found to be ineffective, however, in the protein C activation by thrombin-thrombomodulin (TM) complex on the cell surface. Assay using purified TM revealed that CPB-II was able to exhibit the inhibitory potency for the protein C activation exclusively in the reconstituted system with negatively charged phospholipids. These results suggest that the neutral phospholipids participate in the protein C activation through the thrombin-TM system on the endothelial cell surface. The ability of CPB-II to inhibit procoagulant activity without affecting anticoagulant activity on the cultured endothelial cells is probably related to its potential physiological function, while it is able to exert various degrees of influence upon these activities in blood coagulation by interacting with negatively charged phospholipids in vitro.

Amino Acid Sequence↗
PubMed1992

[Effects of Gomishi and Shosaiko-to on lipid peroxidation of rat brain].

Gomishi and Shosaiko-to were administered to the rats at a dose of 10-100 mg/kg daily for 2 weeks, and their effects on lipid peroxidation of rat brain were compared with that of alpha-tocopherol. Administration of Gomishi and Shosaiko-to showed almost the same suppressive action on the lipid peroxidation. Gomishi and Shosaiko-to exhibited a radical-trapping action on a stable free radical, 1, 1-diphenyl-2-picrylhydrazyl (DPPH), which was estimated photometrically. The effects of Gomishi or Shosaiko-to at concentrations of 10(-3) to 10(-5)g/ml on lipid peroxidation of rat brain homogenates were investigated. The lipid peroxidation was inhibited by the addition of these drugs, and the suppressive effect was also dependent on the concentration. These suppressive effects with Shosaiko-to were stronger than those of Gomishi. These results suggest that the radical trapping action of Gomishi or Shosaiko-to is the likely mechanism suppressing brain lipid peroxidation; Particularly, the suppressive effect on the brain's lipid peroxidation by Shosaiko-to is at least in part due to its radical trapping action and inhibition of O2-. production.

Administration, Oral↗
PubMed1992

Isolation of secretory IgA from feline bile and bile IgA levels in growing cats.

Secretory IgA was isolated from feline bile, using ammonium sulphate precipitation, gel-filtration chromatography and affinity chromatography. It formed a precipitating line between anti-cat whole serum or anti-cat bile serum by immunoelectrophoresis and double diffusion. It consisted of three subunits that molecular weight were 80 kd, 62 kd and 27 kd by SDS-PAGE analysis. The 80 kd protein was equivalent to secretory component of human and other animals. Immunoglobulin levels were observed on bile collected continuously by gallbladder cannulation in growing cats. Although immunoglobulins were not detected in bile of feline fetus, after birth its levels increased gradually. Biliary IgA levels reached the adult levels earlier than that of their serum.

Aging↗
PubMed1992

Unilateral facial swelling and exophthalmos in a patient with polyarteritis nodosa.

A patient with polyarteritis nodosa (PN) presenting with exophthalmos and facial swelling, which are rarely found in PN, is reported. The patient, a 27-year-old male, complained of painful facial swelling and diplopia. Physical examinations showed facial swelling around the right orbit and exophthalmos. After admission, he experienced myalgia in both calves. Laboratory studies disclosed leukocytosis and liver dysfunction. Celiac and renal angiograms showed aneurysms. A biopsy specimen of his left calf showed an arterial inflammatory process. The patient was diagnosed as having PN. He had an excellent response to corticosteroids, with prompt improvement.

Adrenal Cortex Hormones↗
PubMed1992

[Immunohistological investigation of type IV collagen in the basement membrane surrounding the cancer nest (cancer nest membrane) of head and neck squamous cell carcinoma--its relation to frequency of cervical lymph node metastasis].

Lymphoducts and blood vessels exist in the stroma, while none can be detected in the cancer nest itself within cancerous tissue. This explains why metastasis of carcinoma cannot occur without the escape of tumor cells through the basement membrane surrounding the cancer nest into the stroma. Accordingly, observation of the continuity of the basement membrane, what we call the cancer nest membrane, is essential for elucidating the first step of metastasis. Since type IV collagen is the most important structure composing the basement membrane, investigation of the immunohistological localization and continuity of type IV collagen is of value in predicting the metastatic aggressiveness of squamous cell carcinoma. We therefore studied biopsy tissues from the advancing lesion of head and neck squamous cell carcinoma in 95 untreated patients. The tissues were fixed in 85% ethanol and embedded in paraffin, and 5-um thin sections prepared were then immunohistochemically stained for type IV collagen by the ABC method for observation of the continuity status of the cancer nest membrane in relation to metastasis. The basement membranes of normal mucosal epithelium and normal interstitial capillaries were utilized as positive controls, and negative controls were obtained by using PBS in place of the primary antibodies for the immunohistochemical reaction. Membrane discontinuity (breaks or absence) correlated significantly with cervical lymph node metastasis, while intact membrane was associated with a low frequency of cervical lymph node metastasis. There was no obvious relation between the clinical T category and the continuity of the membrane; pN (+) carcinomas with membrane discontinuity included even T1 supraglottic and hypopharyngeal carcinomas, as well as T2 or higher oral mucosal carcinomas and T3 or higher glottic carcinomas, suggesting variation with tumor site. Hypopharyngeal and supraglottic carcinoma was associated with membrane discontinuity and a high incidence of cervical lymph node metastasis. On the other hand, glottic and oral carcinoma more often presented with intact membranes and had a lower incidence of metastasis, although carcinomas in these sites that did present with discontinuity of the membrane were associated with a high incidence of cervical metastasis. Therefore, observation of the continuity of the cancer nest membrane by the expression of type IV collagen may be useful in selecting better specific therapies and determining the necessity of prophylactic neck dissection. A correlation between the degree of tumor differentiation and the continuity of the membrane was also found; well-differentiated tumors with discontinuity of the membrane were frequently associated with cervical lymph node metastasis.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1992

[A case of urinary retention due to tuberculous pyometra].

A rare case of urinary retention due to tuberculous pyometra is presented. A 70-year-old woman visited our hospital complaining of dysuria and pollakisuria on January 26, 1990. In spite of medication of cholinergic agents, urinary retention developed on April 6, 1990. Cystoscopy revealed elevation of the urethra and bladder neck. Physical examinations disclosed a child-head-sized tumor in the lower abdomen, which persisted following catheterization. Excretory urogram showed a large retrovesical mass. Chain urethrocystogram revealed anterior dislocation of the bladder neck and the proximal portion of the urethra. CT scan and MRI demonstrated a fluid-filled pelvic mass, which positioned above the vagina and compressed the urinary bladder anteriorly. Total hysterectomy was performed on August 6, 1990. Pathological diagnosis was tuberculous endometritis. Urinary symptoms disappeared immediately after the operation. Postoperative chain urethrocystography revealed complete cure of the dislocation of the bladder neck and urethra. We collected 34 cases of urinary retention due to gynecological disease in Japan, and 110 cases in English literature. Among the frequent diseases were retroverted gravid uterus, prolapse uteri, uterine leiomyomas, ovarian cyst, imperforated hymen and vaginal atresia. The mechanisms of urinary retention in gynecological disease are discussed. No case of urinary retention due to tuberculous pyometra was found in the literature.

Aged↗
PubMed1992

[An immunohistological study of normal parotid gland].

Cytoskeletal proteins from each epithelial component of the parotid gland were studied immunohistologically using monospecific monoclonal antibodies, and we obtained several interesting results: 1) The expression of vimentin, S-100 protein and GFAP were essentially unrecognizable. 2) The expression of alpha-actin was recognized only in myoepithelial cells, and was negative in other tissues. 3) The expression of CK-3, CK-6, CK-7, CK-8 and CK-18 was commonly recognized in both acinal and ductal cells. 4) The expression of CK-13 and CK-19 was recognized in ductal cells, but was negative in acinal cells. 5) We propose that the characteristic cell be referred to as a "duct satellite cell", as it comprises part of the intercalated duct and is sporadically localized around striated and layer ducts. 6) These duct satellite cells express all subclasses of cytokeratin observed in myoepithelial, acinal and ductal cells. 7) The duct satellite cells observed in this study are most likely to correspond to the undifferentiated reserve cells described in "bicellular theory", and we speculate that all epithelial tissues of the parotid gland originate from these cells.

Actins↗
PubMed1992

[Serotonergic mechanisms in hippocampal kindled seizures--inhibitory effects of L-5-hydroxytryptophan and 8-hydroxy-2-(di-n-propylamino)tetralin].

Serotonin (5-HT) has been considered to possess an inhibitory action against the kindling development, but the role of 5-HT in kindled seizures is unclear. Furthermore, most previous studies have dealt with amygdaloid kindling. To clarify the role of the 5-HT system in epilepsy, we examined the effects of 5-hydroxytryptophan (5-HTP), a precursor which elevates brain 5-HT, and 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), a 5-HT 1 a receptor agonist, on seizures kindled from the feline hippocampus (HIP). Following the completion of HIP kindling, five cats received 0.9% saline, 5-HTP (20 or 40 mg/kg, i.p.) or 8-OH-DPAT (0.1 or 1.0 mg/kg, i.v.). Drugs were administered 15 min (8-OH-DPAT) or 1 hr (5-HTP) prior to electrical stimulation at the generalized seizure triggering threshold, and the anticonvulsant effects were assessed by the behavioral seizure stage and afterdischarge (AD) duration. Both 5-HTP and 8-OH-DPAT suppressed dose-dependently HIP-kindled seizures. The administration of 5-HTP at 40 mg/kg and of 8-OH-DPAT at 1.0 mg/kg produced a marked or complete suppression of HIP-kindled seizures in most of the cats tested, and was found to significantly reduce the seizure stage when compared with the saline control. Both drugs tended to shorten the AD duration, but this effect did not reach statistically significant levels. The present data suggest that the 5-HT system plays an important role in HIP-kindled seizures, and that the 5-HT 1 a receptors have an inhibitory effect on the kindled focal epileptic activity of the HIP.

5-Hydroxytryptophan↗
PubMed1992

Cytoprotective effect of dilazep on hydrogen peroxide-perturbed vascular endothelial cells.

The effect of dilazep and dimethyl thiourea (DMTU) on the hydrogen peroxide-derived injury of culture pulmonary artery epithelial cells (CPAEC) was assessed by colorimetric assay of MTT formazan (MTT formazan assay). When CPAEC were treated with hydrogen peroxide, neither cell lysis nor detachment of the cells from surface of the well was observed. However, the MTT formazan formation was decreased in a time and dose dependent manner. The decrease in the formation was significantly suppressed in the presence of dilazep (0.1 to 10 microM) or DMTU (0.01 to 0.3 microM). CPAEC treated with hydrogen peroxide in the same way enhanced an activation of prothrombin, and this enhancement was significantly inhibited in the presence of dilazep (1 to 3 microM). These data indicate that dilazep exerts a cytoprotective effect against challenges of intracellular oxidant produced by hydrogen peroxide and suppresses augmented procoagulant activity of injured cells.

Animals↗
PubMed1992

[A case of acute idiopathic pandysautonomia--a histochemical study of sural nerve by acetylcholinesterase staining].

A 30-year-old man had an acute onset of orthostatic lightheadedness, sweating disturbance, paroxysmal cough and loss of potency. These symptoms reached the peak in two weeks, and then remitted very slowly. He was admitted to our hospital for further evaluation when he was 39 years old. Neurological examinations revealed right Horner's syndrome, dry skin and impotence, but neither motor nor sensory system was impaired. No abnormalities were found on routine examinations of the blood and cerebrospinal fluid, motor and sensory nerve velocities, computed tomography and electroencephalography. On sural nerve biopsy, the density of unmyelinated fibers was mildly decreased (13,857/mm2), whereas that of myelinated fibers was normal (7,220/mm2). Autonomic function tests disclosed orthostatic hypotension (-31 mmHg) on tilting, reduced levels of serum noradrenaline and vanillyl mandelic acid, supersensitive responses to noradrenaline infusion and adrenaline eye-dripping, severe sweating impairment and complete absence of sympathetic skin response. On the other hand, Aschner's test, Czermak's test and coefficient variation of R-R intervals were all normal. These results suggested that the chief lesion was located in the postganglionic fiber of sympathetic efferent pathway. We (Hayashi et al, 1990) quantified acetylcholinesterase (AchE)-positive fibers in the specimens of sural nerve biopsy, and reported that the density of AchE-positive fibers was correlated to the function of sympathetic postganglionic fibers. The density of AchE-positive fibers in the present case of acute idiopathic pandysautonomia (AIPD) was severely decreased to 225/mm2 by optical microscopy (control: 5,703 +/- 1,289/mm2), and to 2,996/mm2 by electron microscopy (control: 14,112 +/- 3,987/mm2).(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholinesterase↗
PubMed1992

[Metabolic disorders of amino acids due to enzyme mutation--branched-chain amino acids].

Three kinds of inborn error of branched-chain amino acids (valine, leucine isoleucine) are described with a focus on the findings in recent biochemistry and molecular genetics. Frequency of valinemia and leucinisoleucinemia is quite low but their significance is distinct because of our knowledge that at least two aminotransferases, one branched-chain keto acids dehydrogenase and two short-chain acyl-CoA dehydrogenases are present in human, is based on the observations of these limited cases. In MSUD, the sequential study of each subunit cDNA reveals a close relationship between the clinical phenotypes and the various sites of mutation.

Amino Acid Metabolism, Inborn Errors↗
PubMed1992

[Sensitivity test for anti-tumor agents-3. MTT assay and its clinical effect].

MTT assay, a sensitivity test of anti-tumor agents was performed, and its clinical usefulness, was discussed. In 15 surgical specimens, the cell suspensions were prepared aseptically, and divided into three processing; namely, Papanicolaou (Pap) smears to confirm the malignant cells, MTT assay, and cell cultures in chamber slides. MTT assay was evaluated only when tumor cells in the chamber slide were observed 50% or more by Pap staining. Drugs judged to be effective were applied for patients, resulting in 64.2% of predictive accuracy in the sensitivity. Conclusions; 1) MTT assay was developed for sensitivity test of anti-tumor agents, 2) Strict assessment was carried out by the confirmation of cancer cells using chamber slides, 3) On clinical usefulness, predictability for the sensitivity was 64.2%, that for resistance was 100%, and over all predictability was 66.7% 4) MTT assay was useful for the determination of effective and for elimination of ineffective drugs.

Antineoplastic Agents↗
PubMed1992

[Metabolism of Ca2+ in myocytes and peroxidation products in ischemia-reperfusion injury under extracorporeal circulation].

The metabolism of calcium ion (Ca2+) in myocytes in ischemia-reperfusion injury under extracorporeal circulation (ECC) was studied by cytochemistry and electron microscopy. Ten mongrel dogs were under ECC with aortic cross-clamping for 120 minutes. A cold GIK crystalloid cardioplegic solution was infused via the aortic root intermittently during ischemia, and the myocardial temperature was maintained at 5-10 degrees C with ice slush. The morphological changes of Ca(2+)-ATPase activity in myocytes were estimated using the "lead citrate method". The activities of mitochondria, which had been temporarily decreased just before reperfusion, increased immediately after reperfusion and decreased again 60 minutes later. Electromicroscopy revealed swelling of mitochondria and laceration of myofibrils as well as intracellular edema 60 minutes after reperfusion. Immediately after reperfusion and 60 minutes later, creatine phosphokinase iso-enzyme (CK-MB) release in coronary sinus blood was significantly (p < 0.01) greater than that before the start of ECC. Anaerobic metabolism immediately after reperfusion was more active than that before aortic cross-clamping, as demonstrated by changes in excess lactate (delta XL) and redox potential (delta Eh) of lactate and pyruvate (delta XL, p < 0.05; delta Eh, p < 0.01). Thus, in ischemia-reperfusion injury, alterations of Ca(2+)-ATPase activity of mitochondria reflect the functional and morphological viability of the myocardium. Immediately and 60 minutes after reperfusion, the level of thiobarbituric acid was significantly (p < 0.01) higher and the level of alpha-tocopherol was significantly (p < 0.01) less than respective levels before the start of ECC.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[Giant seroma following the Blalock-Taussig shunt using expanded polytetrafluoroethylene (EPTFE) graft: a case report].

A 15-month-old girl, who was diagnosed asplenia, underwent Blalock-Taussig shunt using EPTFE tubular graft. Postoperatively, discharge containing high concentrations of protein continued to drain from pleural drainage. On the 23rd postoperative day, extirpation of seroma (4 x 3 x 3 cm) and wrapping of the graft using processed porcine pericardium were performed. However, pleural discharge did not decrease and caused atelectasis. On the 38th postoperative day, extirpation of seroma (4.5 x 6 x 14 cm) and partial lobectomy were performed. Pleural effusion persisted with decreasing quantity until the graft was obstructed. Ultimately on the 79th postoperative day, central shunt using Golaski tubular graft was successfully replaced. Thus, the occurrence of seroma should be borne in mind when EPTFE graft is used for shunt operation.

Anastomosis, Surgical↗
PubMed1992

[Antitumor effect of carboplatin on in vitro three-dimensional tumor].

We studied the antitumor effect of Carboplatin on the three-dimensional tumor in vitro. First, we observed the three-dimensional growth of cultured tumor cell lines (Hep 2, KB and HT 29 cells), which were developed in the combined culture system of fibrin matrix and agar culture. The tumor cells developed a 3 x 3 mm tumor in diameter in the in vitro 10 day-culture system. This size was large enough to allow the histologic study. When we applied Carboplatin to the three-dimensional tumors, histologic change of the three-dimensional tumor developed from Hep 2 and KB cells were observed in a dose dependent manner. However, no remarkable histologic change was observed in the three-dimensional tumor developed from HT 29 cells. These results suggest the experimental system of three-dimensional tumor can predict histologically the antitumor effect of Carboplatin on various tumors at the solid tumor level.

Carboplatin↗