Impact of BK polyomavirus viremia on the outcomes of allogeneic hematopoietic stem cell transplantation.

Although it is known that BK polyomavirus (BKPyV) causes hemorrhagic cystitis (HC) after allogeneic hematopoietic stem cell transplantation (HSCT), the clinical significance of BKPyV viremia has not been fully evaluated. We retrospectively analyzed the results of quantitative polymerase chain reaction (PCR) evaluations for detecting BKPyV in the whole blood samples of patients undergoing allogeneic HSCT during the period from January 2010 to June 2020 at a single institute, Tokyo Medical and Dental University. BKPyV was detected in the blood of 28 of the 107 evaluated patients, and the cumulative incidence of was 27.9% (95%CI: 20.2-37.9%). HC due to BKPyV developed in four of the 28 patients with BKPyV viremia (14.3%) and in two of the 79 patients without it (2.5%; P < 0.05). BKPyV viremia itself did not affect the patients' post-transplant estimated glomerular filtration rate (eGFR), but BKPyV viremia with a high viral load was significantly associated with decreased eGFR values (P < 0.05). BKPyV viremia was also associated with significantly lower progression-free survival at 3 years (35.1% [95%CI: 17.8-53.1%] vs. 60.4% [95%CI: 48.4-70.5], P < 0.05). Our findings demonstrated that BKPyV viremia was associated with onset of HC, an early decline of renal function, and poorer survival after allogeneic HSCT. Further studies are needed to test these results and elucidate the mechanisms of renal dysfunction associated with BKPyV viremia.

[Bacteremia due to Rothia mucilaginosa after chemotherapy for myeloid malignancies].

The number of reported cases of bacteremia due to Rothia mucilaginosa (R. mucilaginosa), a component of the normal flora of human gastrointestinal tract mucosa, is limited. We encountered three cases of bacteremia due to R. mucilaginosa during neutropenia after chemotherapy for myeloid malignancies. Although all three patients were successfully treated with antimicrobial agents, one patient developed disseminated lesions in the lungs and soft tissue. The portal of R. mucilaginosa bacteremia is reportedly mucositis or dental disorders; however, no such complications were identified in our patients. Even in the absence of a preexisting portal, R. mucilaginosa should be recognized as a potential causative pathogen of bacteremia during neutropenic periods. Accumulations of cases and isolates are required to further elucidate the risk factors for developing R. mucilaginosa bacteremia, its clinical course, and the optimal antimicrobial treatment.

Stabilization of organic field-effect transistors by tert-butyl groups in dibenzotetrathiafulvalene derivatives.

For a material for organic thin-film transistors, not only high mobility but also low threshold voltage and long-term stability are important requirements. In order to realize these properties, materials with relatively large oxidation potentials, namely weak donors, have been designed as p-channel organic semiconductors. Here we propose a different strategy; transistor properties of dibenzotetrathiafulvalene (DBTTF) are significantly improved by the introduction of tert-butyl groups. Although this chemical modification does not much change the ionization potential, small threshold voltage and stability over several months are attained together with the improved mobility, probably due to some kind of passivation effect of the bulky tert-butyl groups. In contrast, the systematic fluorine substitution rapidly diminishes the transistor performance. There are two kinds of herringbone structures with much different dihedral angles of about 50° and 130°, and the tert-butyl compound falls into the former category.

Management of generalized severe periodontitis using full-mouth disinfection and systemic antibiotics in a leukemic patient before stem cell transplantation: A case report.

The full-mouth disinfection protocol implemented in this case can be integrated into established protocols for treating severe periodontitis in the context of a hematological malignancy, without any interference with the cancer treatment.

Efficacy of mouth rinse in preventing oral mucositis in patients receiving high-dose cytarabine for allogeneic hematopoietic stem cell transplantation.

High-dose cytarabine is one of the major components of the conditioning regimen for hematopoietic stem cell transplantation (HSCT), and frequently causes severe oral mucositis. We have recently demonstrated that cytarabine is excreted into the saliva in patients receiving high-dose cytarabine, and proposed that it might locally and directly contribute to the development of oral mucositis. Therefore, this study was performed to assess whether removing the excreted cytarabine in the saliva by intensive mouth rinse during high-dose cytarabine infusion could reduce the incidence of oral mucositis. Fifteen patients with hematologic malignancies undergoing allogeneic HSCT who received total body irradiation (12 Gy) and high-dose cytarabine at a dose of 3 g/m(2) every 12 h for 4 days as a conditioning were evaluated. Patients were instructed to rinse their mouths using ice-cold water every 10 min, starting simultaneously with the 2-h cytarabine infusion and continuing up to 1 h after completion of each infusion. Oral mucositis was graded on a daily basis according to the National Cancer Institute, Common Toxicity Criteria. Thirty-five patients who previously underwent the same conditioning without mouth rinse served as controls. The incidence of Grades 2-3 and Grade 3 oral mucositis was significantly reduced in patients who performed mouth rinse as compared with the controls (40 vs. 80%, P = 0.009; 0 vs. 25. 7%, P = 0.02). In conclusion, mouth rinse during and shortly after high-dose cytarabine infusion could be an effective and inexpensive measure in reducing the incidence of moderate to severe oral mucositis caused by high-dose cytarabine. This finding strongly suggests the role of cytarabine excretion in the saliva in the development of cytarabine-associated oral mucositis.

Excretion of cytosine arabinoside in saliva after its administration at high doses.

High-dose cytosine arabinoside (cytarabine) is widely used, either alone or in combination with other chemotherapeutic agents, for the treatment of refractory hematological malignancies. Its pharmacology in plasma and cerebrospinal fluid has been extensively examined. In this study, we measured the concentration of cytarabine in saliva of nine patients with hematological malignancies who received high-dose cytarabine. Cytarabine at a dose of 3 g/m was administered i.v. over 2 h. Saliva samples were collected before initiating cytarabine infusion, within 15 min after the completion of infusion and 2 or 4 h after infusion. The concentration of cytarabine was measured by HPLC methods. All nine patients showed a detectable level of cytarabine in saliva within 15 min after the completion of infusion (0.58+/-0.48 microg/ml), which was equivalent to 5% of its plasma concentration; however, the drug was no longer detectable in saliva thereafter. These findings suggest that cytarabine is excreted in saliva during and shortly after its administration at a high dose.