Flow cytometric estimation of cytotoxic activity of rhodexin A isolated from Rhodea japonica in human leukemia K562 cells

We have examined the cytotoxic effect of rhodexin A isolated from the extract of Rhodea japonica on human leukemia K562 cells using a flow cytometer and compared it with that of ouabain. Rhodexin A at 30 nM started to attenuate growth without affecting viability and further increases in the concentration of rhodexin A (100 nM or more) completely inhibited growth with decreasing viability. Rhodexin A at 30-100 nM increased the G(2)M population, but decreased the G(0)G(1) population, suggesting cell cycle arrest in the G(2)M phase. Rhodexin A at 100 nM increased the number of cells with hypodiploid DNA, indicating that rhodexin A induced apoptosis. The potency of rhodexin A to inhibit growth was greater than that of ouabain. The results indicate that rhodexin A exerts a potent inhibitory action on the growth of human leukemia K562 cells by inducing cell cycle arrest and apoptosis. Rhodexin A may also be a candidate for cancer treatment because there have been clinical reports of tumor regression in patients taking cardiac glycosides.     

Exposure of rat thymocytes to hydrogen peroxide increases annexin V binding to membranes: inhibitory actions of deferoxamine and quercetin

N(G)-(Nitro-L-arginine (L-NOARG), an inhibitor of nitric oxide synthase, induces catalepsy in mice. The objective of the present work was to investigate if serotonergic drugs are able to modulate this effect. Results showed that the cataleptogenic effect of L-NOARG (40 mg/kg) in male albino-Swiss mice was enhanced by pre-treatment with (+)-N-tert-butyl-3-(4-[2-methoxyphenyl]piperazin-1-yl)-2-phenylpro panamide ((+)-WAY-100135, 5 or 10 mg/kg), a 5-HT1A-selective receptor antagonist, and by ketanserin (5 or 10 mg/kg), a 5-HT2A receptor and alpha1-adrenoceptor antagonist. Prazosin (3 or 5 mg/kg), an alpha1-adrenoceptor antagonist, and endo-N-(8-methyl-8-azabicyclo[3.2.1]oct-3yl)-2,3-dihydro-3,3-dimet hyl-indole-1-carboxamide HCl (BRL-46470A, 0.05 or 0.5 mg/kg), a 5-HT3 receptor antagonist, did not interfere with L-NOARG-induced catalepsy. Ritanserin (3 or 10 mg/kg), a 5-HT2A and 5-HT2C receptor antagonist, tended to enhance the effect of L-NOARG. These results confirm that interference with the formation of nitric oxide induces catalepsy in mice, and suggest that this effect is modulated by 5-HT1A and 5-HT2A receptors.     

Protein characterization ofBabesia equi piroplasms isolated from infected horse erythrocytes

Proteins ofBabesia equi piroplasms were characterized. The piroplasms ofB. equi were purified by lysis of infected horse erythrocytes with N₂ gas cavitation followed by separation in Percoll density-gradient centrifugation. The relative molecular weights (Mr) of major proteins separated by two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis were 18, 28, 30, 41, 43, 54, 66.5, and 96 kDa. Immunoblot analysis using serum from an experimentally infected horse revealed six immunodominant proteins of 15, 18, 28, 30, 41, and 96 kDa. Two immunodominant proteins of 18 and 28 kDa were membrane-bound proteins as revealed by Triton X-114 phase partitioning.     

Early central nervous system complications after reduced-intensity stem cell transplantation.

To investigate clinical characteristics of early central nervous system (CNS) complications after reduced-intensity stem cell transplantation (RIST), we reviewed the medical records of 232 patients who had undergone RIST for hematologic diseases at our institutions between September 1999 and June 2003. All patients had received purine analog-based preparative regimens. Stem cell sources comprised granulocyte colony-stimulating factor-mobilized blood from HLA-identical or 1 locus-mismatched related donors (n = 151), unrelated bone marrow (n = 44), or unrelated cord blood (n = 37). Graft-versus-host disease prophylaxis incorporated cyclosporine with or without methotrexate. Diagnosis of CNS complications was based on clinical, radiologic, and microbiological findings. CNS complications occurred in 18 patients (7.8%), with a median onset of 22 days, and were infectious (n = 1), metabolic (n = 15), or cerebrovascular (n = 2). Symptoms included seizures (n = 7), visual disturbance (n = 2), headache (n = 8), nausea (n = 8), vomiting (n = 6), impaired consciousness (n = 16), and hemiparesis (n = 3). Complications improved promptly in 10 patients, and 8 patients died without improvement within 30 days. Multivariate analysis with logistic regression identified umbilical cord blood transplantation as a significant risk factor for early CNS complications (odds ratio, 14.5; 95% confidence interval, 3.7-56.9; P <.0001). CNS complications are a significant problem after RIST, particularly with umbilical cord blood. Limbic encephalopathy is an unrecognized subtype of neurotoxicity after umbilical cord blood transplantation.     

The presence of a novel protein in calf serum that recognizes beta amyloid in the formalin-fixed section.

Here we report on a monoclonal antibody, H6-33, that labels various beta-amyloid plaques, including diffuse plaques in the formalin-fixed, paraffin-embedded section from the brain affected with Alzheimer''s disease (AD), without formic acid pretreatment. H6-33 also labels some neurofibrillary tangles and all kuru plaques in Gerstmann-Sträussler-Scheinker disease. In sharp contrast, H6-33 did not stain beta amyloid in the leptomeningeal vessel. For specific staining, H6-33 required the presence of fetal calf serum and it was necessary for beta amyloid to be formalin fixed. These results suggest that a novel protein in the calf serum, CSX, binds formalin-fixed beta amyloid, followed by H6-33 binding. The detection of beta amyloid by CSX was nullified by formic acid pretreatment of the tissue section. In accordance with this, CSX reacted only with a polymer form of synthetic beta peptide after fixation, but not with native beta-protein or beta-peptide monomer. These observations strongly suggest that 1) meningovascular beta amyloid should have a beta-pleated sheet structure somewhat dissimilar to that of beta-amyloid cores; and 2) most, if not all, of beta-protein immunoreactivities of diffuse plaques in AD sections are presumably derived from small amounts of amyloid fibrils scattered in the normal-looking neurohil.     

Meteorological observations at Hiroshima on days with weather similar to that of the atomic bombing.

An attempt to explain discrepancies between measured neutron-induced radioactivities (i.e., 152Eu, 60Co) and calculated yields based on the Dosimetry System 1986 was made by considering moist air densities at different altitudes over Hiroshima, Japan. The investigation checked the validity of moist air density estimates used in the Dosimetry System 1986 computer codes. Meteorological observations were conducted to obtain atmospheric temperature and pressure profiles for the Hiroshima area. By coupling these observations with surface measurements taken on 6 August 1945 at Ebayama Park (3.6 km from the hypocenter), estimates of temperature, pressure, and humidity at the time of detonation were derived. This allowed the calculation of densities for dry air, moist air, and water vapor. The results proved similar to the Dosimetry System 1986 estimates. Water vapor density calculations showed the largest difference (at most 7%). These results imply that the 152Eu yield contradiction in the Dosimetry System 1986 calculations vs. real measurements for large ground distances (> 900 m) is not the result of an erroneous estimate of moist air density in Hiroshima.     

Early immune reaction after reduced-intensity cord-blood transplantation for adult patients

BACKGROUND: To investigate immune reactions after reduced-intensity cord-blood transplantation (RI-CBT). MATERIALS AND METHODS: We reviewed medical records of 57 adult RI-CBT recipients. Preparative regimen comprised fludarabine, total-body irradiation, and either melphalan (n=51) or busulfan (n=6). Graft-versus-host disease (GvHD) prophylaxis was cyclosporine. PostRI-CBT immune reactions were classified according to time course: pre-engraftment immune reactions (PIR), engraftment syndrome (ES), and GvHD. RESULTS: Forty-five patients achieved engraftment at a median of day 19. PIR was characterized by high-grade fever and weight gain and developed on a median of day 9 in 35 of the 45 evaluable patients, including 3 who did not achieve engraftment. PIR subsided spontaneously in 12 patients, whereas corticosteroids were required in the other 23. ES and grade I to IV acute GvHD developed in 36 and 29 patients, respectively. GvHD could not be distinguished from preceding PIR or ES in 10 patients. Causes of the 32 nonrelapse mortalities included GvHD (n=5) and PIR (n=1). There were no significant differences in relapse and nonrelapse deaths between patients with PIR and those without it (18% vs. 5%, and 60% vs. 65%, respectively). CONCLUSIONS: Immune reactions after RI-CBT can be categorized into three distinct subtypes.     

Regenerative medicine of the trachea: the first human case

OBJECTIVES: The objective of the present study was to demonstrate regenerative medicine of the tracheal tissue by using an in situ tissue engineering technique for airway reconstruction. METHODS: Based on the previous successful experimental animal studies, the current regenerative technique was applied to repair of the trachea of a 78-year-old woman with thyroid cancer. A Marlex mesh tube covered by collagen sponge was used as a tissue scaffold. The operative intervention included right hemithyroidectomy, resection of the trachea, and tracheoplasty using the scaffold. The right half of three rings of the trachea was resected, and the scaffold material was sutured to the defect of the trachea. RESULTS: After 2 weeks, the mesh collagen structure of the artificial material could be seen with endoscopy in most of the implanted area. The artificial material was covered with epithelial growth after 2 months. Epithelialization continued to cover the artificial material completely for 2 years without any complications. CONCLUSIONS: The current regenerative technique avoided tracheotomy, a second operation, and deformity. Good epithelialization has been observed on the tracheal luminal surface without any complications for 2 years. Although long-term observation is required, regenerative medicine of the tracheal tissue appears feasible for airway reconstruction.