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Biomedical subjects

Akiko Hori

Publications and source records attributed to Akiko Hori.

27 records · Page 2Linked to original sources

Quantitative formation of [2]catenanes using copper(I) and palladium(II) as templating and assembling centers: the entwining route and the threading approach.

Transition metal-mediated templating and self-assembly have shown powerful potentials for the synthesis of interlocked molecules. These two strategies were combined in designing and preparing a new type of coordination catenanes incorporating Cu(I) and Pd(II) metal centers. The ligand designed here contains a phenanthroline core and pyridine sidearms (compound 1). Using this phenanthroline-pyridine conjugated ligand, two approaches were examined, which were shown to be surprisingly efficient for the catenane synthesis: the entwining route (entwining of two ligands around Cu(I) followed by Pd(II) clipping) and the threading approach (Cu(I)-templated threading of a cyclic ligand on an acyclic ligand followed by the Pd(II) clipping of the second ring). In the former method, stepwise treatment of 1 with Cu(CH(3)CN)(4)PF(6) (templating center) and enPd(NO(3))(2) (assembling center) gives rise to the quantitative formation of CuPd(2) catenane 18. In the latter method, Cu(I) templates the threading of phenanthroline-containing macrocycle 2 on ligand 1, which is followed by Pd(II) clipping to give hetero catenane 20. In both approaches, the formation of catenanes is convincing thanks to the strong templating effect of Cu(I), while the ring closure steps are efficiently furnished by Pd(II)-directed self-assembly.

Journal Article↗

Feasibility of acute physiology and chronic health evaluation (APACHE) II and III score-based screening in patients receiving allogeneic hematopoietic stem-cell transplantation.

Patients who require management in the intensive care unit (ICU) for complications after allogeneic hematopoietic stem-cell transplantation (HSCT) generally have a poor outcome. We retrospectively studied whether the risk-prediction stratification systems commonly used for patients admitted to the ICU, that is, the Acute Physiology and Chronic Health Evaluation (APACHE) II and APACHE III systems, could be useful for identifying patients who should receive intensive care earlier. We reviewed the medical records of 210 patients who underwent allogeneic HSCT and found that 18 (8.6%) had been admitted to the ICU for acute respiratory failure (n=9), acute renal failure (n=7), and septic shock (n=2). The median APACHE II and III scores were, respectively, 16 (10-27) and 55 (22-87) at the onset of complications and 26 (15-43) and 101 (65-157) upon admission to the ICU. Thus, both the APACHE II and APACHE III scores at ICU admission were higher than those at the onset of complications (P <0.0001). Seventeen patients (94%) subsequently died, with a median ICU stay of 7.5 days (1-51 days), as a result of multiorgan failure (n=14), respiratory failure (n=2), and septic shock (n=1). The APACHE II and III scores of the sole surviving patient were, respectively, 21 and 71 at the onset and 24 and 86 upon transfer to the ICU. Thus, the APACHE scores in this study were lower than those reported for other surgical or medical patients treated in the ICU, despite their uniform poor prognosis. Although nine patients had developed grade III to IV acute graft-versus-host disease, which is the most common cause of morbidity and mortality after allogeneic HSCT, this was not fully evaluated in the current scoring systems. Application of these systems to HSCT will require adequate modification, with particular attention to organ dysfunction secondary to graft-versus-host disease.

APACHE↗

TRALI after the infusion of marrow cells in a patient with acute lymphoblastic leukemia.

BACKGROUND: TRALI is one of the most serious, life-threatening complications after blood transfusion. Antibodies against neutrophils or HLA molecules from the donor are thought to be the primary causative agents. Rarely, antibodies in the recipient may react with transfused neutrophils and initiate the same events, which raises the possibility that TRALI may also occur in an allogeneic PBPC transplantation setting. CASE REPORT: A 30-year-old Japanese man with acute lymphoblastic leukemia developed TRALI immediately after the infusion of marrow cells from an unrelated donor. The infusion was suspended, and he gradually improved after receiving steroids and oxygen support. The next day, the remaining cells, which were separated to MNCs, were infused with no reactions. He then recovered over 5 days without the use of mechanical ventilation. RESULTS: Laboratory evaluation disclosed the presence of antibodies to neutrophils in his sera sampled after transplantation, but not in the donor's marrow graft. Hence, antibodies to neutrophils in the recipient may have reacted with neutrophils in the graft and contributed to the development of TRALI. CONCLUSION: This is the first reported case of TRALI after allogeneic BMT. TRALI should be recognized as a rare but serious complication in allogeneic hematopoietic stem cell transplantation.

Acute Disease↗

Limited efficacy of lamivudine against hepatitis B virus infection in allogeneic hematopoietic stem cell transplant recipients.

BACKGROUND: Reactivation of chronic hepatitis B virus (HBV) infection is a major complication when HBV carriers receive immunosuppressive therapy. Recipients of allogeneic hematopoietic stem cell transplantation (HSCT) carry the highest risk of fatal HBV disease (up to 12%). METHODS: In an attempt to identify a suitable procedure for the prevention and management of HBV reactivation, the administration of lamivudine over the course was tested in two patients. RESULTS: Generally, the patients transplant courses were successfully managed despite their difficult clinical situations: a high HBV load before transplant in one patient and intense steroid therapy for complicated acute graft-versus-host disease (GVHD) in the other patient. However, one patient showed a reactivation of HBV after discontinuing lamivudine and the other showed persistently high DNA polymerase activity despite prolonged administration of lamivudine. CONCLUSIONS: We concluded that lamivudine could have a place in the management of patients who suffer from chronic HBV infection and who are undergoing allogeneic HSCT. However, the efficacy of lamivudine seemed to be limited compared with other settings, including solid organ transplantation and autologous HSCT.

Adult↗

Effect of fluconazole prophylaxis on fungal blood cultures: an autopsy-based study involving 720 patients with haematological malignancy.

To investigate the utility of blood culture of invasive fungal infections in patients with haematological malignancies, an autopsy survey was conducted in 720 patients who were treated between 1980 and 1999. We identified 252 patients with invasive mycosis. These included Candida (n = 94), Aspergillus (n = 91), Zygomycetes (n = 34), Cryptococcus (n = 7), Trichosporon (n = 11), Fusarium (n = 1), and unknown fungi (n = 20). Of the 94 patients with invasive candidiasis, 20 had positive blood cultures. Of the 11 patients with invasive trichosporonosis, seven had positive blood cultures. The sensitivities of blood cultures were 1.1%, 0% and 14% for detecting invasive aspergillosis, zygomycosis and cryptococcosis respectively. Multiple regression analysis showed a significant correlation between results of Candida blood cultures and some variables, including prophylactic use of absorbable antifungals (P = 0.0181) and infection by Candida albicans (P = 0.0086). The sensitivity of blood cultures decreased when patients received antifungal chemoprophylaxis. Unless these agents are inactivated in culture bottles, conventional blood cultures might produce false-negative results.

Adolescent↗