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Biomedical subjects

A Sakai

Publications and source records attributed to A Sakai.

At least 181 records · Page 10Linked to original sources
PubMed1995

[Haemophilus aphrophilus isolated from the blood of a patient with infective endocarditis].

On July 1994, a 62-year-old female, having a history of mitral regurgitation, was admitted because of high fever, hematuria and conjunctival petechiae. She was diagnosed as having infective endocarditis with mitral valve vegetation proved by ultrasonic cardiography. The gram negative rods were isolated from blood cultures performed five times, performed prior to the administration of antibiotics. The isolates were identified as strains of H. aphrophilus. After two days of treatment with PCG (12 million units/day), the organism became undetectable from the blood. Since the minimal inhibitory concentrations (MICs) of PCG and ABPC were ranged between 0.06-2.0 micrograms/ml and 0.06-0.5 microgram/ml, respectively, ABPC was selected as a first choice antibiotic instead of PCG. ABPC was given 12 g/day for the first 3 days, then 6 g/day for 28 days, followed by 3 g/day for 7 days. The patient recovered and was discharged after the 55 hospital days. H. aphrophilus grew on BTB lactose agar, chocolate agar and sheep blood agar, but failed to grow on MacConkey agar. H. aphrophilus produced smooth transparent nonhaemolytic micro colonies after 48 hours on sheep blood agar and chocolate agar plates. Atmosphere with 5% CO2 failed to enhance their growth. All the five strains of H. aphrophilus isolated, required neither factors V nor X. Positive synthesis of porphyrin from delta-aminolevlinic acid confirmed their ability to grow without X factor. For the correct identification of H. aphrophilus strains, fermentation test of glucose, lactose, maltose and sucrose in either phenol red broth or CTA medium are necessary.(ABSTRACT TRUNCATED AT 250 WORDS)

Ampicillin↗
PubMed1995

Augmentation of tumor immunity by 6-mercaptopurine (6-MP) and its analogs in the double grafted tumor system in mice.

We investigated the antitumor effect of 6-mercaptopurine (6-MP) and its analogs using the double grafted tumor technique. BALB/c mice were inoculated intradermally with MethA fibrosarcoma cells at the right inguinal region on day 0 (the primary tumor) and at the left on day 10 (the secondary tumor). Intraperitoneal or intra-lesional administration of 6-MP, 6-mercaptopurine riboside (6-MP-r) and 6-mercaptopurine riboside triacetate (6-MPRTA) from day 3 to 7 dose-dependently inhibited growth of the secondary tumor. Without the primary inoculation, 6-MP showed no effect on growth of the tumor inoculated on day 10, indicating that the antitumor effect of 6-MP could not be attributable to its direct antimetabolic or tumoricidal action only, and that the primary tumor inoculation is necessary for these compounds to inhibits growth of the challenging tumor. 6-MP did not inhibit the secondary MethA growth in the BALB/c (nu/nu) mouse. Both CD4+ and CD8+ T cells increased in the spleen of mice treated with 6-MP. Meanwhile, delayed-type hypersensitivity (DTH) reaction to the methylated bovine serum albumin (MBSA) antigen at the footpad was not augmented but inhibited by 6-MP-r and 6-MPRTA in both normal and tumor-bearing mice. Thus, the immunomodulatory activity of 6-MP could be observed in two opposite directions, augmentation of tumor immunity and inhibition of DTH to MBSA. This indicates that the immune mechanism and/or the type of effector cells induced in these two cell-mediated immune systems are different from each other.

Adjuvants, Immunologic↗
PubMed1995

[Two cases of left atrial myxoma originating from mitral annulus].

We experienced two cases of left atrial myxoma originating from mitral annulus. Mitral valve replacement and mitral valvulo-annuloplasty were performed in each case, because of the presence of mitral leaflet defect due to removal of the myxoma. Two dimensional echocardiography was a useful method to confirm the location and decide the surgical approach.

Adult↗
PubMed1995

[Repeat open heart surgery in a case associated with persistent left superior vena cava: a method of simple occlusion of L-SVC using an alternative extra-pericardial approach and retrograde cardioplegia].

Twelve years ago, we reported a method of extrapericardial approach to the L-SVC. Since then we have used this approach and performed simple occlusion of L-SVC during cardiopulmonary bypass without any cerebral complications. We have been expecting for a long time and have believed that this method will be very valuable especially in repeat open heart surgery. A case of 49-year-old man successfully underwent a redo operation for mitral and tricuspid valve replacement using extrapericardial occlusion of the L-SVC and retrograde cardioplegia. Although there was a pitfall for retrograde cardioplegia in the persistent L-SVC and a possibility of steal of cardioplegic fluid through a branch of the accessory hemiazygos vein during retrograde cardioplegia for a case with persistent L-SVC, sufficient cardiac protection was obtained in the case presented.

Aortic Valve↗
PubMed1995

Effect of TJ-96, an anti-allergic herbal medicine, on tracheal transepithelial potential difference in vivo.

We studied the effect of Saiboku-to (TJ-96), an anti-allergic herbal medicine, on transepithelial potential difference of rabbit trachea and possible involvement of nitric oxide (NO) generation in vivo. Perfusion of TJ-96 on the tracheal mucosal surface increased PD in a concentration-dependent manner, the maximal increase from the baseline level and the concentration of TJ-96 required to produce a half-maximal effect (EC50) being 8.1 +/- 1.4 mV (mean +/- SE, P < 0.001) and 47 micrograms/ml. This effect was abolished by pretreatment with the Na channel blocker amiloride. NG-nitro-L-arginine methylester (L-NAME) but not NG-nitro-D-arginine methylester (D-NAME) inhibited TJ-96-induced increase in PD, and this inhibition was selectively reversed by L-arginine. These results suggest that TJ-96 stimulates Na absorption by airway epithelial cells probably through NO generation.

Amiloride↗
PubMed1995

[Mitral valve replacement through a right thoracotomy, with intact coronary artery bypass grafts].

A 68-year-old male who had previously undergone aorto-coronary artery bypass grafting was admitted for mitral valve surgery. Because of the presence of anteriorly placed intact coronary artery bypass grafts, we used right thoracotomy to replace the mitral valve. Cardiopulmonary bypass was established after cannulation of the femoral artery and bicaval cannulation, and continuous retorograde cardioplegia with cold blood was infused. Residual air was evacuated through left ventricular vent catheter and aortic air vent hole. Post operative course was uneventful.

Aged↗
PubMed1995

[von Recklinghausen's disease and its pathogenesis].

von Recklinghausen's disease was first described in 1882. Formerly, it was considered a single disease, but is now known to be two distinct disease, neurofibromatosis 1 (NF 1, peripheral form of neurofibromatosis) and neurofibromatosis 2 (NF 2, bilateral acoustic neurofibromatosis). Neurofibromatosis is inherited as an autosomal dominant with a high rate of penetrance. NF 1 gene is located in the pericentromeric region of chromosome 17. NF 2 gene is localized to chromosome 22. Clinically, there are some characteristic signs and symptoms. The typical NF 1 patient has café-au-lait spots, melanin pigmentation and palpable neurofibromas, while NF 2 has its onset with the development of tinnitus or hearing loss, due to the presence of bilateral acoustic neuroma.

Genes, Neurofibromatosis 1↗
PubMed1995

[Acute lung injury and chemical mediators].

The essential abnormality in acute lung injury is an increase in pulmonary permeability. The mechanisms involved are complex, and may include direct effects on endothelial cells; the actions of neutrophils, macrophages, and lymphocytes; and chemical mediators generated by these cells. Neutrophils are known to be important in acute lung injury, and the mediators they produce, especially protease and oxidants, may be responsible for endothelial cell injury. We studied the roles of neutrophil elastase and oxygen radicals in acute lung injury by Escherichia coli endotoxin in sheep with lung lymph fistulae. The results of these and other studies indicate that these substances are related to the increase in pulmonary permeability during the late phase of injury.

Acute Disease↗
PubMed1994

Hac1: a novel yeast bZIP protein binding to the CRE motif is a multicopy suppressor for cdc10 mutant of Schizosaccharomyces pombe.

We cloned by phenotypic complementation a novel Saccharomyces cerevisiae's multicopy suppressor of the Schizosaccharomyces pombe cdc10-129 mutant which we call HAC1, an acronym of 'homologous to ATF/CREB 1'. It encodes a bZIP (basic-leucine zipper) protein of 230 amino acids with close homology to the mammalian ATF/CREB transcription factor and gel-retardation assays showed that it binds specifically to the CRE motif. HAC1 is not essential for viability. However, the hac1 disruptant becomes caffeine sensitive, which is suppressed by multicopy expression of the yeast PDE2 (Phosphodiesterase 2) gene. Although the mRNA level of HAC1 is almost constitutive throughout the cell cycle, it fluctuates during meiosis. The upstream region of the HAC1 gene contains a T4C site, a URS (upstream repression sequence) and a TR (T-rich) box-like sequence, which reside upstream of many meiotic genes. These results suggest that HAC1 may also be one of the meiotic genes.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1994

Cloning of cDNAs for fructose 6-phosphate 2-kinase/fructose 2,6-bisphosphatase from frog skeletal muscle and liver, and their expression in skeletal muscle.

Frog (Rana catesbeiana) skeletal muscle (M-type) and liver (L-type) cDNAs of fructose 6-phosphate 2-kinase/fructose 2,6-bisphosphatase were isolated from lambda gt10 phage cDNA library. The full-length L-type cDNA (1829 bp) encodes a 469 amino acids subunit (M(r) 54,800), while the M-type cDNA (1792 bp) encodes 455 amino acids (M(r) 52,901). The amino acid sequence of the M-type isozyme is identical to that of the L-type isozyme except for the N-terminus. The N-terminal 30 amino acids of the L-type isozyme are replaced by an unique sequence of 16 amino acids in the M-type isozyme. Both L- and M-type cDNAs were detected also in a lambda gt10 phage library of skeletal muscle. Relative amount of the M- and L-type mRNAs is skeletal muscle was determined by the reverse transcription-polymerase chain reaction method. The M/L mRNA ratio in frog skeletal muscle shows seasonal variations, being 0.56/1 in early summer and 5.3/1 in winter. These results suggest that there is a seasonal change in the isozyme composition and that the glycolysis in frog skeletal muscle may be regulated by type of the isozyme synthesized.

Amino Acid Sequence↗
PubMed1994

Molecular cloning and tissue specific expression of fructose 6-phosphate,2-kinase:fructose 2,6-bisphosphatase of rat brain.

A cDNA clone (3591 base pairs) encoding an isozyme of Fructose 6-phosphate, 2-kinase:Fructose 2,6-bisphosphatase was isolated from a rat brain cDNA library. The 5' sequence of this clone (1241 base pairs) was identical to that of the heart type isozyme cDNA (except for 7 base pair mismatches), but the 3' nucleotide sequence (2024 base pairs) was completely different. Its deduced amino acid sequence showed that the enzyme lacked a regulatory domain which contained phosphorylation sites for protein kinase A and C. The results of Northern blotting and polymerase chain reaction demonstrated that the mRNA, 7.4 kilobases long, was expressed also in heart, testis, liver, and skeletal muscle.

Alternative Splicing↗
PubMed1994

Neurotoxicity of glucocorticoids in the primate brain.

Severe and prolonged physical and psychological stress is known to cause brain damage; long-term torture victims in prison have later developed psychiatric disorders and cerebral cortical atrophy observed in CT scans (Jensen, Genefke, Hyldebrandt, Pedersen, Petersen, and Weile, 1982). In nonhuman primates, we observed degeneration and depletion of the hippocampal neurons in African green monkeys that had been severely abused by cagemates and died with complications of multiple gastric ulcers and adrenal cortical hyperplasia (Uno, Tarara, Else, Suleman and Sapolsky, 1989). In our previous studies the administration of dexamethasone (DEX) (5 mg/kg) to pregnant rhesus monkeys at 132 to 133 days of gestation induced degeneration and depletion of the hippocampal pyramidal and dentate granular neurons in the brains of 135-gestation-day fetuses, and these changes were retained in the brains of fetuses at near term, 165 days of gestation (Uno, Lohmiller, Thieme, Kemnitz, Engle, Roecker, and Farrell, 1990). We also found that implantation of a cortisol pellet in the vicinity of the hippocampus in adult vervet monkeys induced degeneration of the CA3 pyramidal neurons and their dendritic branches (Sapolsky, Uno, Rebert, and Finch, 1990). Thus, hippocampal pyramidal neurons containing a high concentration of glucocorticoid receptors appear to be highly vulnerable to either hypercortisolemia caused by severe stress or to exposure to exogenous glucocorticoids. To study the long-term postnatal sequelae of prenatal brain damage, eight rhesus monkeys were treated with either DEX (5 mg/kg), 5 animals, or vehicle, 3 animals, at 132 to 133 days of gestation. After natural birth, all animals lived with their mothers for 1 year. At 9 months of age, we found that DEX-treated animals had significantly high plasma cortisol at both base and post-stress (isolation) levels compared to age-matched vehicle-treated animals. Magnetic resonance images (MRI) of the brain at 20 months of age showed an approximately 30% reduction in size and segmental volumes of the hippocampus in DEX-treated compared to vehicle-treated animals. Measurements of whole brain volume by MRI showed no significant differences between DEX and vehicle groups. Prenatal administration of a potent glucocorticoid (DEX) induced an irreversible deficiency of the hippocampal neurons and high plasma cortisol at the circadian baseline and post-stress levels in juvenile rhesus monkeys. These results suggest that the hippocampus mediates negative feedback of cortisol release; a lack or deficiency of the hippocampal neurons attenuates this feedback resulting in hypercortisolemia.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1994

TGF-beta 1 causes increased endothelial ICAM-1 expression and lung injury.

Neutrophil adherence to vascular endothelium is partially mediated by adhesion molecules, including intracellular adhesion molecule 1 (ICAM-1), on endothelial cells. We examined the effect of transforming growth factor-beta 1 (TGF-beta 1) on the expression of ICAM-1 in human umbilical vein endothelial cells (HUVEC). TGF-beta 1 (1 ng/ml) increased ICAM-1 and ICAM-1 mRNA expression in HUVEC, as assessed by flow cytometry and Northern blot analysis, respectively. In addition, we investigated whether exogenous recombinant TGF-beta 1 can cause neutrophil-mediated lung injury in guinea pigs. The plasma half-life of 125I-labeled TGF-beta 1 in guinea pigs was 4.6 +/- 0.1 min, and the 125I activity was 2.8 +/- 0.2% 8 h after injection. The ratio of 125I-labeled albumin concentration in lung tissue and bronchoalveolar lavage (BAL) fluid to that in plasma, lung wet-to-dry weight ratio, numbers of neutrophils in BAL fluid, and numbers of neutrophils per alveolus in fixed lung sections increased in guinea pigs that received a high dose of TGF-beta 1 (25 micrograms i.v. followed by 2 micrograms/h for 8 h) compared with the control group. These results suggest that TGF-beta 1 causes neutrophil-mediated lung injury, possibly through upregulation of ICAM-1 on endothelial cells, and might be important in the pathogenesis of lung injury.

Animals↗
PubMed1994

Effects of ONO-5046, a specific neutrophil elastase inhibitor, on endotoxin-induced lung injury in sheep.

The purpose of the present study was to assess the role of polymorphonuclear leukocyte (neutrophil) elastase in endotoxin-induced acute lung injury in sheep with lung lymph fistula. We studied the effects of ONO-5046, a specific inhibitor of neutrophil elastase, on the lung dysfunction induced by the intravenous infusion of 1 microgram/kg of Escherichia coli endotoxin. Endotoxin alone produced a biphasic response as previously reported. Early (0.5-1 h) after endotoxin, pulmonary arterial pressure increased from 19.5 +/- 0.9 cmH2O at baseline to a peak of 46.8 +/- 2.4 cmH2O (P < 0.05). Pulmonary vascular resistance increased from 3.03 +/- 0.17 cmH2O.l-1.min at baseline to a peak of 9.77 +/- 0.70 cmH2O.l-1.min (P < 0.05). Circulating neutrophils decreased from 7,355 +/- 434/mm3 at baseline to a nadir of 1,762 +/- 32/mm3 (P < 0.05). Thromboxane B2 and 6-ketoprostaglandin F1 alpha concentrations in plasma and lung lymph were significantly increased. Late (3-5 h) after endotoxin, pulmonary arterial pressure and pulmonary vascular resistance returned to baseline levels, but lung lymph flow remained increased from 4.2 +/- 0.3 ml/0.5 h at baseline to 7.3 +/- 0.7 ml/0.5 h (P < 0.05), with a slight increase in lung lymph-to-plasma protein concentration ratio, suggesting increased pulmonary vascular permeability. The histopathological features of the lungs during the early period in sheep treated with endotoxin alone revealed a large increase in neutrophils per 100 alveoli and changes of pulmonary edema such as thickening of the interstitium of the lung and alveolar flooding.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗
PubMed1994

Therapeutic effect of reticuloendothelial system (RES)-avoiding liposomes containing a phospholipid analogue of 5-fluorouracil, dipalmitoylphosphatidylfluorouridine, in Meth A sarcoma-bearing mice.

Reticuloendothelial system (RES)-avoiding liposomes are known to accumulate in tumor tissues due to passive targeting. Dipalmitoylphosphatidylfluorouridine (DPPF), a potent antitumor agent readily incorporated into the lipid bilayer, was embedded in RES-avoiding liposomes modified with a uronic acid derivative, palmityl-D-glucuronide (PGlcUA). The therapeutic effect of DPPF in PGlcUA-liposomes was examined in tumor-bearing mice. Free or liposomal DPPF was injected intravenously into BALB/c mice bearing subcutaneously implanted Meth A sarcomas. The RES-avoiding liposomal formulation using PGlcUA was effective in reducing tumors, and prolonging survival time compared with free DPPF and also DPPF in conventional liposomes. Therefore, PGlcUA-liposomes might be of practical use as drug carriers for anticancer agents, especially their derivatives for embedding in liposomal membranes.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1994

Development and application of an enzyme immunoassay for karasurin A, an effective protein component of Trichosanthes kirilowii Max. var. japonicum Kitam.

A method was developed for specific estimation of the content of a non-enzymatic protein, karasurin A, in fractions taken during the extraction and purification processes from a natural source. Anti-karokon serum was elicited in rabbits immunized with fragments of karokon, a dried root tuber of Trichosanthes kirilowii Max. var. japonicum Kitam. Rabbit antibody specific for karasurin A was identified in anti-karokon serum by the Western blotting method. After separation by SDS-PAGE, protein bands of purified karasurin A and extracted proteins from a medicinal herb which is a karasurin A source were reacted with anti-karokon serum followed by treatment with horseradish peroxidase (HRP)-labeled Fab' of goat anti-rabbit IgG, and then bound HRP-labeled second antibody on protein bands was developed to brown by reaction with a substrate solution of the used enzyme. A novel selected antibody enzyme immunoassay (SAEIA) for karasurin A was developed using selective binding of anti-karasurin A antibody in anti-karokon serum to solid phase karasurin A and HRP-labeled Fab' of the second antibody as the tracer. Specific estimation of the content of karasurin A in several fractions taken during the isolation and purification processes of the protein were possible using the SAEIA method.

Animals↗
PubMed1994

Hispidospermidin, a novel phospholipase C inhibitor produced by Chaetosphaeronema hispidulum (Cda) Moesz NR 7127. I. Screening, taxonomy, and fermentation.

A novel phospholipase C inhibitor, hispidospermidin, was discovered from a fungal culture broth. The producing fungus, NR 7127, formed abundant pycnidia on banana leaf agar under near UV light. The ostiolate pycnidia were dark colored with a short beak possessing numerous protruding setae. The conidiogeneous cells were phialidic. The conidia were hyaline, 1 septate, smooth and spindle-shaped. From these distinctive characteristics, this strain was identified as Chaetosphaeronema hispidulum (Cda) Moesz of the Coelomycetes. Hispidospermidin was produced in a 50-liter jar fermentor containing 2% glucose, 2% potato starch, 2% Toast soya, 0.5% yeast extract, 0.25% NaCl, 0.0005% ZnSO4.7H2O, 0.0005% CuSO4.5H2O, 0.0005% MnSO4.4H2O, 0.32% CaCO3, and 0.3% Nissan disfoam CA-115. Fermentation was conducted at 27 degrees C at an aeration rate of 30 liters/minute and agitated at 500 rpm for 95 hours. Maximum production yield of hispidospermidin was observed after 72 hours. Hispidospermidin inhibited rat brain phospholipase C at 16 microM of IC50. This is the first recorded discovery of a secondary metabolite from the genus Chaetosphaeronema.

Animals↗