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Biomedical subjects

H Saitoh

Publications and source records attributed to H Saitoh.

At least 19 recordsLinked to original sources
PubMed1992

Carrier-mediated transport system for choline and its related quaternary ammonium compounds on rat intestinal brush-border membrane.

The characteristics of the intestinal transport system for choline were investigated using isolated brush-border membrane vesicles from rat small intestine. In spite of the diminutive lipid solubility, the uptake of choline by membrane vesicles reflected smooth permeation into intravesicular space rather than the binding to the membrane surface. Physiological conditions, present in the intact intestine, such as an inward-directed Na+ or H+ gradient and inside negative membrane potentials, didn't directly involve in choline transport across the brush-border membrane. Moreover, an outward-directed H+ gradient had no significant effect on the time course of choline transport. However, in the absence of a driving-force, the initial uptake of choline exhibited a saturable manner. A kinetic analysis of the initial uptake rate gave an apparent Km of 159 microM. Furthermore, unlabeled choline caused both cis-inhibition and trans-stimulation for labeled choline transport, suggesting the existence of a carrier-mediated transport system for choline, classified as so-called 'facilitated diffusion'. Since tetramethylammonium, acetylcholine, and N1-methylnicotinamide caused both cis-inhibition and trans-stimulation, they appear to be accepted as the substrate of choline carrier. On the other hand, quaternary ammonium compounds (QACs) such as those which possessed hydrophobic parts in their molecules exhibited only cis-inhibition. They also inhibited Na(+)-dependent D-glucose transport, indicating that they influenced various carrier-mediated transport systems non-specifically due to interaction with the membrane. These findings strongly suggest that the choline transport system on the brush-border membrane of rat intestine recognizes only small molecular QACs as its substrate.

Animals↗
PubMed1992

CENP-C, an autoantigen in scleroderma, is a component of the human inner kinetochore plate.

We have isolated and characterized a set of overlapping cDNA clones that encode the human centromere autoantigen centromere protein C (CENP-C). The identity of these clones has been established using several criteria. First, they were shown to encode a polypeptide that migrates at the expected position for CENP-C on SDS-polyacrylamide gel electrophoresis. Second, we have demonstrated that this polypeptide shares at least two epitopes with human CENP-C. Polyclonal antibodies were raised to fusion proteins encoded by nonoverlapping regions of the cDNA clones. These antibodies were shown to recognize a protein at a position appropriate for CENP-C on immunoblots of human chromosomal proteins. In addition, we used indirect immunofluorescence to demonstrate that these antibodies recognize centromeres of HeLa chromosomes in the expected pattern for CENP-C. Localization of CENP-C by immunoelectron microscopy reveals that this protein is a component of the inner kinetochore plate.

Amino Acid Sequence↗
PubMed1992

Uptake characteristics of polyamines into rat intestinal brush-border membrane.

The uptake characteristics of polyamines, such as spermine, spermidine and putrescine, have been investigated using brush-border membrane vesicles isolated from the small intestine of rats. The uptake of these polyamines into the membrane vesicles was high and the order of uptake was spermine greater than spermidine greater than putrescine at medium pH 7.5, respectively. The medium pH considerably affected the uptake of these polyamines and the amount of uptake increased remarkably with an increase of the medium pH (pH 7.5 or 8.0 greater than pH 5.5). An inward Na+ gradient did not stimulate the uptake rate of any of these polyamines. We have also examined the binding behaviour to the membrane lipid, phospholipids and total lipid, and there was a good correlation in the binding properties, pH-dependency and uptake activity, between the liposomes and brush-border membrane vesicles. These results suggest that the uptake of the polyamine into the vesicles consisted of rapid binding to the outside intestinal surface and slower binding to the inside membrane after permeation. Furthermore, findings from experiments concerning the mutual inhibition among these polyamines and concerning the effect of other polycations, having 2-5 amines in number, on the uptake of spermine, suggest that the number of amino groups in the polyamine molecules plays an important role in the uptake process into the brush-border membrane vesicles.

Animals↗
PubMed1992

A case of cardiac foreign bodies associated with four types of tachycardias.

A case of cardiac foreign bodies leading to development of four varieties of automatic tachycardia is reported. A 51-year-old male with aortic regurgitation was admitted to our hospital because of palpitations. An electrocardiogram revealed junctional tachycardia with or without left bundle branch block, and two types of fascicular tachycardias. Computed tomography showed metallic foreign bodies from a fractured guidewire in the membranous portion of the interventricular septum, which was inadvertently retained when he underwent diagnostic cardiac catheterization at the age of 27.

Bundle-Branch Block↗
PubMed1992

The pH dependent uptake of enoxacin by rat intestinal brush-border membrane vesicles.

The mechanism of the intestinal transport of enoxacin, an orally active fluoroquinolone antibiotic, has been investigated using brush-border membrane vesicles isolated from rat small intestine. The initial rate and time-course of enoxacin uptake were considerably dependent upon the medium pH (pH 5.5 greater than pH 7.5) and upon the percent ionization of the carboxyl group (pKa 6.2, anionic charge), namely, the degree of uptake of cationic form was higher than that of the zwitterionic form. There was evidence of transport into the intravesicular space as shown by the effect of extravesicular medium osmolarity on enoxacin uptake at steady state (30 min). This transport across the brush-border membrane was stimulated by the valinomycin-induced K(+)-diffusion potential (interior negative) and an outward H(+)-diffusion potential. Furthermore, changing the pH of the medium from 5.5 to 7.5 significantly decreased the effect of valinomycin-induced K(+)-diffusion potential on the enoxacin uptake. These results suggest that the uptake behaviour of the cationic form of enoxacin plays an important role in the intestinal absorption process of enoxacin.

Animals↗
PubMed1992

High-resolution CT of the temporal bone: a modified baseline.

High-resolution computed tomography (CT) of the temporal bone, particularly axial scanning on a baseline parallel to the orbitomeatal line, produces radiation exposure to the patient's lenses. The authors evaluated the radiation dose to the lens and the visualization of temporal bone structures with use of scanning along the orbitomeatal line and on a line parallel to the hard palate. Evaluation of visualization was performed by five radiologists, with high-resolution CT scans of 45 healthy patients, and the chi 2 test was performed for comparison. The change of the baseline from the orbitomeatal line to a line parallel to the hard palate decreased the radiation dose to the lens from 12.7 cGy to 0.274 cGy and improved visualization of the stapes superstructure and the tympanic portion of the facial nerve canal, although visualization of the incus body, incudostapedial joint, lateral semicircular canal, and oval window was of equal quality. Therefore, the authors recommend a new baseline parallel to the hard palate for use at high-resolution CT of the temporal bone.

Health Personnel↗
PubMed1992

Antitumor activity of Hypsizigus marmoreus. I. Antitumor activity of extracts and polysaccharides.

Antitumor activity of Hypsizigus marmoreus, one of the most popular Japanese edible mushrooms, was investigated. The aqueous and methanol extracts were tested against allogeneic tumor, solid sarcoma 180 and syngeneic tumor, Meth A fibrosarcoma. The aqueous extract was highly active in inhibiting growth of solid sarcoma 180, but not as much for Meth A fibrosarcoma. Fractionation of antitumor substances of the aqueous extract isolated four polysaccharides. Chemical analysis revealed one of them to be beta-(1-3)-glucan with a remarkable inhibitory effect against tumor-growth of sarcoma 180.

Animals↗
PubMed1992

Intracranial germinoma and Down's syndrome--case report.

A germinoma in the basal ganglia developed in a 9-year-old boy with Down's syndrome, presenting as left hemiparesis. An initial computed tomographic (CT) scan demonstrated no notable abnormalities, but serial CT scans followed the entire course of tumor growth. Subtotal removal and irradiation achieved tumor remission. This is the first case reported of intracranial germinoma associated with Down's syndrome.

Brain Neoplasms↗
PubMed1992

Cavernous angioma of the cerebellum and cerebellar atrophy--case report.

A cavernous angioma of the cerebellum occurred in a 55-year-old female presenting with a 3-year history of slowly progressive cerebellar signs and symptoms. Computed tomography and magnetic resonance imaging revealed a lesion in the left cerebellar nuclei and atrophic change of the affected cerebellar hemisphere. The final diagnosis was made at operation. The cerebellar nuclei and white matter were probably affected by the slowly expanding lesion, with repeated hemorrhage leading to degeneration of the afferent and efferent fibers, and subsequent atrophy of the affected cerebellar hemisphere.

Atrophy↗
PubMed1992

[Studies on the fragments of FDP in 4 patients with DIC].

We previously studied fibrinolysis and fibrinogenolysis by analyzing fragments of fibrin/fibrinogen degradation products (FDP) employing sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. In this report, we characterized the fragments of FDP in four patients with disseminated intravascular coagulation (DIC), that were caused by various diseases. In the patients suffering from acute lymphoblastic leukemia (case 1) and acute suppurative cholangitis (case 3), DD and DY/X fragments resulting from fibrinolysis accounted for the most part of the FDP fragments. In case 3, D fragments resulting from fibrinogenolysis were also observed to much less extent. In a DIC associated with acute myeloblastic leukemia (case 2), both fibrinolysis and fibrinogenolysis were increased and resulted in high levels of D, Y and DY/X fragments, concomitant with moderate levels of DD and high molecular weight (HMW) fragments in the patient's sera. The increased fibrinogenolysis in this case was attributed to accelerated activation of plasmin. In a DIC patient of case 4, who underwent an operation due to hepatocellular carcinoma, marked increase in DY/X and HMW fragments and slight increase in DD fragment were observed on the day of operation. Hyperfibrinolysis documented in case 4 was explained by both increased production of thrombin and moderately accelerated activation of plasmin. Both qualitative and quantitative changes in the fragments of FDP during the courses of treatment in two cases of DIC were also noted. In summary, each underlying disease expresses characteristic pattern of FDP fragments in DIC.

Adolescent↗
PubMed1992

[Effects of anti-PAF agents on nasal response after allergen challenge in guinea pigs].

We previously reported that Platelet-activating factor (PAF) activities were detected in nasal lavage fluids from patients with allergic rhinitis and in ovalbumin (OA) sensitized guinea pigs after topical allergen challenge. In guinea pigs, a topical application of PAF produced an increase in nasal vascular permeability which was inhibited by a PAF-antagonist (CV3988). To define the role of PAF in allergic rhinitis, we examined the effects of anti-PAF agents (WEB2086) and anti-allergic agents (Azelastine) on nasal airway resistance (NAR) and nasal symptoms in actively sensitized guinea pigs. Guinea pigs (200-300g) were sensitized by intraperitoneal injection of OA (10 micrograms/kg) and alum (5mg/kg) three times at two week intervals and repeated inhalation of OA (1mg/min., for 3 minutes) everyday for four weeks. The NAR was measured serially for 6 hours by an apparatus using the oscillation method. NAR change was expressed as a percent ratio to the pre-challenge value. Nasal symptoms were evaluated by counting the number of sneezing discharges and scratching movements for 30 minutes. The anti-PAF agent or Azelastine were administered orally at 2-3 hours before the topical allergen challenge. We noted a biphasic increase in NAR after allergen challenge. The increase in NAR during early phase was not affected but that during late phase was significantly inhibited by the anti-PAF agent and Azelastine. The nasal symptoms were inhibited by WEB2086 and Azelastine. Our results suggest that PAF activities might play an important role in late phase NAR increase following allergen challenge.

Airway Resistance↗
PubMed1992

[The local hyperthermochemotherapy for pleural carcinomatosis].

Local hyperthermochemotherapy was performed in 17 cases to control malignant effusion and intrathoracic disseminated lesions. Of these 15 patients, 11 cases primary lung cancer, 4 cases metastatic lung cancer had pleural carcinomatosis and 2 cases were malignant diffuse mesotheliomas. The procedure was radiofrequency hyperthermia (13.56 MHz) maintaining the peripleural temperature at 42-43 degrees C for 45-60 minutes, combined simultaneously with the intrathoracic administration of cisplatin (1-2 mg/m2, bolus) through a thoracic double lumen trocar tube. The treatment was repeated from 2 to 4 times at 7-day intervals. In 14 cases (87.5%) complete or partial response according to the criteria of the Japan Lung Cancer Society were obtained. There were 2 cases of no change and one case that was impossible to evaluate. In one lung cancer case, the disappearance of pleural disseminated lesions was confirmed by flexible thoracoscopy after the procedure. In 12 cases, there were abdominal complaints due to side effects of the hyperthermochemotherapy, such as vomiting and nausea, but these symptoms were milder than those caused by intravenous injection of anti-cancer agents, for example cisplatin, in conventional chemotherapy treatment. The median survival time and 2 years survival of the patients with the present procedure were 15 months and 41.7% respectively. Although distant metastases appeared in most cases, none had local recurrence and particularly noteworthy pleural effusion was well controlled. The above experience suggested that the local hyperthermochemotherapy is useful to control pleural effusion and can improve the quality of life of patients with pleural carcinomatosis.

Aged↗
PubMed1992

[A case of invasive broncho-pulmonary aspergillosis associated with influenza A (H3N2) infection].

A 49-year-old man with high alcohol consumption was admitted with fever, cough and progressive dyspnea after a one week history of influenza-like symptoms. Chest X-ray film on admission showed diffuse peribronchial shadows and patchy infiltration in the right lower lung field. Chest X-ray film the following day and chest CT film on the 4th day of admission showed multiple nodular shadows and cavity formation. At bronchoscopy the bronchial surface was covered by white plaque, and Asp. fumigatus was subsequently cultured from BAL fluid. On the basis of suspected invasive pulmonary aspergillosis, anti-fungal agents were commenced. However, the shadows on chest X-ray increased, and the patient died on the 10th day of admission of respiratory failure and septic shock. Histological examination revealed bronchial wall invasion by hyphae of aspergillus and abscess formation in the pulmonary parenchyma. The precipitin antibody against aspergillus antigen was positive in reserved serum. Anti-Influenza A virus antibody (CF) was positive (X 256), and hemagglutination inhibition test of Influenza A (H3N2) was positive (X 2048) in serum on admission. The suppression of cellular immunity and destruction of the mucociliary system of airways induced by Influenza A infection was suspected to have predisposed to aspergillus superinfection.

Aspergillosis↗
PubMed1992

[A report of two cases of multilocular cystic renal cell carcinoma: review of 51 cases reported and the results of a prognostic survey].

We report 2 cases of multilocular cystic renal cell carcinoma. One was in a 33-year-old male, presenting with ultrasonic abnormality of the left kidney at an annual employee health care examination. Computerized tomography (CT) demonstrated a 5 cm of multilocular cystic mass adjacent to the lower pole of the left kidney. Another was in a 44-year-old male, presenting with microscopic hematuria at an annual employee health care examination. CT of the abdomen revealed a 6.5 cm of multilocular cystic mass on the upper pole of the right kidney. Both were diagnosed as renal cell carcinoma by the angiography and underwent radical nephrectomy. Gross specimens showed typical multilocular cystic appearance and histopathology showed clear cell carcinoma infiltrating septa and replacing epithelium of the cyst walls. Both patients are alive without evidence of disease at, 21 months and 14 months after operation, respectively. Including our cases, 51 multilocular cystic renal cell carcinoma and multilocular cystic nephroma associated with renal cell carcinoma have been reported. From the review of the literatures and the answer of the questionnaires inquiring about the outcome of the patient to Japanese reporters, the outcome of 38 patients was ascertained. The 10-year survival rates and non-recurrence rate after operation calculated by the Kaphan-Meier formula were 97.3% and 90.3%, respectively. Because of the good prognosis of reported cases, we concluded that we should choose kidney-sparing surgery for the operation of multilocular cystic renal cell carcinoma.

Adult↗
PubMed1992

[Surgical treatment of coarctation of the aorta].

Repair of coarctation of the aorta was performed in 37 cases (31 patients, 6 patients of reoperation) ranging from 4 days old to 15 years old. Subclavian flap repair were performed in 15, resection and end-to-end anastomosis in 14, patch aortoplasty in 6, and interposition graft in 2. Subclavian flap angioplasty or end-to-end anastomosis is considered the procedure of choice in infants. However, the incidence of reoperation significantly increased in patients younger than age one month at initial subclavian flap repair. Mechanism of recurrent coarctation may be possibly related to retention of abnormal tissue, which is possibly ductal and/or intimal shelf, with the potential for proliferation and luminal narrowing. We suggest that in applicable case end-to-end anastomosis rather than subclavian flap angioplasty may be the surgical technique of choice in infants less than one month of age, and the most common reoperation technique was patch aortoplasty in re-stenosed cases.

Adolescent↗