Virtual monochromatic image at lower energy level for assessing pancreatic ductal adenocarcinoma in fast kV-switching dual-energy CT.

AIM: To evaluate the value of virtual monochromatic images (VMIs) at lower energy levels in fast-voltage-switching dual-energy computed tomography (DECT) for assessing pancreatic ductal adenocarcinoma (PDAC). MATERIALS AND METHODS: The institutional review board approved this prospective study. Written informed consent was obtained from all patients. Seventy-four consecutive patients with PDAC underwent dynamic contrast-enhanced DECT. Two radiologists reviewed eight energy levels (40, 45, 50, 55, 60, 65, 70, and 75 keV) of the pancreatic parenchymal phase VMIs. CT attenuation of the PDAC and pancreatic parenchyma, background noise, signal-to-noise ratio (SNR) of the pancreas, tumour-to-pancreas contrast-to-noise ratio (CNR), major and minor axes of PDAC, and qualitative tumour conspicuity were compared among the VMIs at eight energy levels. RESULTS: CT attenuation of PDAC and pancreatic parenchyma, background noise, SNR, and CNR peaked on VMIs at 40 keV with statistically significant difference (p<0.0001) and gradually decreased with increasing energy levels. The reproducibility in measuring tumour size was better on VMIs at 40 keV (28.8 and 29.2 mm of major axis in readers 1 and 2, respectively) and tended to be overestimated at higher energy levels (29.8 and 30.9 mm of major axis at 75 keV in readers 1 and 2, respectively). Qualitative tumour conspicuity was also significantly superior on VMIs at 40 keV than at all other energy levels (p<0.0001). CONCLUSION: VMIs at 40 keV demonstrated significantly increased SNR of the pancreas, CNR, and tumour conspicuity and high reproducibility in measuring tumour size for assessing PDAC.

Pancreatic MRI associated with pancreatic fibrosis and postoperative fistula: comparison between pancreatic cancer and non-pancreatic cancer tissue.

AIM: To evaluate the potential value of magnetic resonance imaging (MRI) for predicting postoperative pancreatic fistula (POPF) in patients with pancreatic cancer (PC) and non-pancreatic cancer (non-PC). MATERIAL AND METHODS: This retrospective study was approved by the institutional review board and written informed consent was waived. Forty patients underwent pancreatoduodenectomy due to PC (n=31) and non-PC (n=9). The pancreas-to-muscle signal intensity ratio (SIR) on three-dimensional (3D)- fast field echo (FFE) T1-, in- and opposed-phase T1-, and T2-weighted images, as well as the apparent diffusion coefficient (ADC) value of the pancreas were measured. The frequency of POPF and MRI measurements were compared between patients with PC and non-PC. The MRI measurements were also compared with the grade of pancreatic fibrosis on pathological findings, fat deposition, and interstitial oedema. RESULTS: The frequency of POPF was significantly higher in patients with non-PC than in those with PC (p=0.0067), with an odds ratio of 10.4. The SIR on 3D-FFE T1-weighted images was significantly higher in patients with non-PC (p=0.0001) and those with POPF (p=0.017) than in those with PC and those without POPF, respectively. Multiple regression analysis demonstrated that the SIR on 3D-FFE T1-weighted image was independently associated with the grade of pancreatic fibrosis (p<0.0001). CONCLUSION: The frequency of POPF was significantly higher in patients with non-PC than in those with PC was inversely related to the grade of pancreatic fibrosis. The SIR on 3D-FFE T1-weighted image might be a potential imaging biomarker for predicting POPF.

Right adrenal vein: comparison between adaptive statistical iterative reconstruction and model-based iterative reconstruction.

AIM: To compare right adrenal vein (RAV) visualisation and contrast enhancement degree on adrenal venous phase images reconstructed using adaptive statistical iterative reconstruction (ASiR) and model-based iterative reconstruction (MBIR) techniques. MATERIAL AND METHODS: This prospective study was approved by the institutional review board, and written informed consent was waived. Fifty-seven consecutive patients who underwent adrenal venous phase imaging were enrolled. The same raw data were reconstructed using ASiR 40% and MBIR. The expert and beginner independently reviewed computed tomography (CT) images. RAV visualisation rates, background noise, and CT attenuation of the RAV, right adrenal gland, inferior vena cava (IVC), hepatic vein, and bilateral renal veins were compared between the two reconstruction techniques. RESULTS: RAV visualisation rates were higher with MBIR than with ASiR (95% versus 88%, p=0.13 in expert and 93% versus 75%, p=0.002 in beginner, respectively). RAV visualisation confidence ratings with MBIR were significantly greater than with ASiR (p<0.0001, both in the beginner and the expert). The mean background noise was significantly lower with MBIR than with ASiR (p<0.0001). Mean CT attenuation values of the RAV, right adrenal gland, IVC, and hepatic vein were comparable between the two techniques (p=0.12-0.91). Mean CT attenuation values of the bilateral renal veins were significantly higher with MBIR than with ASiR (p=0.0013 and 0.02). CONCLUSION: Reconstruction of adrenal venous phase images using MBIR significantly reduces background noise, leading to an improvement in the RAV visualisation compared with ASiR.

Renovascular CT: comparison between adaptive statistical iterative reconstruction and model-based iterative reconstruction.

AIM: To compare contrast enhancement and image quality between renovascular computed tomography (CT) images with adaptive statistical iterative reconstruction (ASiR) and that with model-based iterative reconstruction (MBIR). MATERIAL AND METHODS: This retrospective study was approved by the institutional review board and written informed consent was waived. Twenty-five consecutive patients who underwent renovascular CT were enrolled in this study. The same raw projection data were reconstructed using ASiR 40%, 100%, and MBIR. Background noise, CT attenuation, and signal-to-noise ratio (SNR) of the renal vessels and kidneys, and image quality were compared among the three reconstruction techniques. RESULTS: Mean background noise was significantly lower with MBIR at the first and second phases than those with ASiR 40% and 100% (p<0.0001). Mean CT attenuation of the abdominal aorta, renal artery, and renal cortex obtained at the first phase and those of the renal vein and renal medulla at the second phase were comparable among the three techniques (p=0.051-1.00). Mean SNRs of the abdominal aorta, renal artery, renal cortex, renal vein, and renal medulla were significantly higher with MBIR than with ASiR 40% or 100% (both p<0.0001). The depiction of the renal artery and vein as well as image quality significantly improved with MBIR compared with those with ASiR 40% and 100% (p<0.0001-0.0016). CONCLUSION: Reconstruction of renovascular CT images with MBIR significantly reduces background noise, leading to an improvement in SNR and image quality compared with that using ASiR.

The long-term use of soap does not affect the pH-maintenance mechanism of human skin.

BACKGROUND: The pH at the surface of healthy human skin is around 5. Cleansing the skin with soap increases the pH of the skin, which then returns to a more acidic pH within a few hours. However, the effects of skin cleansing with soap over a long time on the pH regulatory system is still unclear. OBJECT: We compared the pH of the skin between users of a soap-based cleanser and of a mild-acidic cleanser prior to and following the cleansing. METHOD: This study had two groups of subjects, one group who had used a soap-based cleanser for more than 5 years and the other group who had used a mild-acidic cleanser for more than 5 years. The pH on the inner forearm of each subject was measured prior to and for 6 h after cleansing with a soap bar. RESULT: There were no differences between the pH of the skin these two groups prior to cleansing, immediately after cleansing or in the pH recovery rate for 6 h. CONCLUSION: These results suggest that long-term continuous use of a soap-based cleanser does not affect the pH-maintaining mechanism of human skin.

Incorporation of apical lymph node status into the seventh edition of the TNM classification improves prediction of prognosis in stage III colonic cancer.

BACKGROUND: The node classification outlined in the seventh edition of the TNM classification is based solely on the number of metastasized lymph nodes. This study examined the prognostic value of apical lymph node (ALN) metastasis and the additional value of incorporating ALN status into a risk model based on the seventh edition. METHODS: This was a cohort study of patients with stage III colonic cancer who underwent tumour resection with dissection of regional (including apical) lymph nodes at 71 hospitals across Japan between 2000 and 2002. The main exposure was pathologically confirmed ALN metastasis, and the primary endpoint was cancer-specific death. RESULTS: ALN metastasis was present in 113 (8·3 per cent) of 1355 patients. During 5356 patient-years of follow-up (median 5·0 years), 221 instances (16·3 per cent) of cancer-specific death were observed. After adjustment for tumour and node classification (as described in the seventh edition of the TNM classification) and other prognostic factors, ALN metastasis was found to be independently associated with cancer-specific death (hazard ratio 2·29, 95 per cent confidence interval (c.i.) 1·49 to 3·52). Incorporation of ALN metastasis into the prognostic model based on the seventh edition of the TNM classification significantly improved discriminative performance for cancer-specific death (difference in concordance index 0·0146, 95 per cent c.i. 0·0030 to 0·0262) and risk reclassification for cancer-specific death at 5 years (category-free net reclassification improvement 19·4 (95 per cent c.i. 5·0 to 33·4) per cent). CONCLUSION: Assessment of ALN metastasis provided independent prognostic information beyond that achievable with the seventh edition of the TNM classification in patients with stage III colonic cancer.

Global spread and genetic variants of the two CYP9M10 haplotype forms associated with insecticide resistance in Culex quinquefasciatus Say.

Insecticide resistance develops as a genetic factor (allele) conferring lower susceptibility to insecticides proliferates within a target insect population under strong positive selection. Intriguingly, a resistance allele pre-existing in a population often bears a series of further adaptive allelic variants through new mutations. This phenomenon occasionally results in replacement of the predominating resistance allele by fitter new derivatives, and consequently, development of greater resistance at the population level. The overexpression of the cytochrome P450 gene CYP9M10 is associated with pyrethroid resistance in the southern house mosquito Culex quinquefasciatus. Previously, we have found two genealogically related overexpressing CYP9M10 haplotypes, which differ in gene copy number (duplicated and non-duplicated). The duplicated haplotype was derived from the non-duplicated overproducer probably recently. In the present study, we investigated allelic series of CYP9M10 involved in three C. quinquefasciatus laboratory colonies recently collected from three different localities. Duplicated and non-duplicated overproducing haplotypes coexisted in African and Asian colonies indicating a global distribution of both haplotype lineages. The duplicated haplotypes both in the Asian and African colonies were associated with higher expression levels and stronger resistance than non-duplicated overproducing haplotypes. There were slight variation in expression level among the non-duplicated overproducing haplotypes. The nucleotide sequences in coding and upstream regions among members of this group also showed a little diversity. Non-duplicated overproducing haplotypes with relatively higher expression were genealogically closer to the duplicated haplotypes than the other non-duplicated overproducing haplotypes, suggesting multiple cis-acting mutations before duplication.

Identification of four members of the Anopheles funestus (Diptera: Culicidae) group and their role in Plasmodium falciparum transmission in Bagamoyo coastal Tanzania.

The role of Anopheles funestus group in malaria transmission was investigated in Bagamoyo coastal Tanzania, in the process of characterizing the area as a malaria vaccine testing site. Mosquitoes were sampled inside houses and multiplex PCR was used to identify 649 specimens. The following species were found: A. funestus s.s. (84.3%), A. leesoni (13.6%), A. rivulorum (1.5%) and A. parensis (0.6%). Multiplex PCR of 147 blood-fed specimens showed that over half (57.1%) of the identifiable blood meals were taken from human hosts, and human blood index in A. funestus and A. leesoni was 55% and 82% respectively. Plasmodium falciparum infection rate determined by nested PCR was 11% in A. funestus s.s. Although the abundance was low, 26 specimens of A. leesoni, two of A. rivolurum and one of A. parensis were found positive for P. falciparum. The presence of four A. funestus species in Tanzania emphasizes the relevance to define precisely their spatial and temporal distribution, specific behaviour, ecology and exact role in malaria transmission.

Improved maintenance of adult rat alveolar type II cell differentiation in vitro: effect of hydrocortisone and cyclic AMP.

We have examined the effect of hydrocortisone and cyclic AMP on the maintenance of lipid synthesis in primary cultures of adult rat alveolar type II cells. These hormones were tested in the presence of either 1% or 5% charcoal-stripped rat serum (CS-rat serum). The effect of substratum on responsiveness to these hormones was evaluated by comparing cells cultured for 4 days on tissue culture plastic, on floating type I collagen gels, on rat lung fibroblast feeder layers on floating collagen gels (floating feeder layers), and on Engelbreth-Holm-Swarm (EHS) tumor basement membrane gels. Type II cells cultured on floating feeder layers in medium containing 1% CS-rat serum and 10(-5) M hydrocortisone plus 0.5 mM dibutyryl cyclic AMP exhibited significantly increased incorporation of [14C]acetate into total lipids (238% of control). The hormone combination also increased the relative percentage of acetate incorporated into phosphatidylglycerol (PG; 7.3% versus 1.9%) and saturated phosphatidylcholine (PC; 43.6% versus 37.6%). The percentage of acetate incorporated into neutral lipids was significantly decreased by the addition of hormones (28.6% versus 70.0%). The addition of hydrocortisone and cyclic AMP to medium containing 5% CS-rat serum resulted in an increase in the relative incorporation of acetate into saturated PC (51.2% versus 46.4%), but had no effect on the relative incorporation of acetate into PG or on the incorporation of acetate into total lipids. Type II cells cultured on EHS gels in medium containing 1% CS-rat serum plus hydrocortisone and cyclic AMP showed increased acetate incorporation into total lipids (204% of control) and a relative decrease in the percentage of acetate incorporated into neutral lipids (16.9% versus 47.0%). The hormone combination also increased the relative incorporation of acetate into PG (4.4% versus 2.5%) and saturated PC (49.9% versus 42.1%). Hydrocortisone and cyclic AMP added to medium containing 5% CS-rat serum concentration increased the relative incorporation of acetate into saturated PC by type II cells on EHS gels, but these additions had no effect on acetate incorporation into PG. No responses to these soluble factors were seen when type II cells were cultured on floating type I collagen gels without feeder layers or on tissue culture plastic. These data indicate that there are positive interactions between substratum, soluble factors and serum in the maintenance of differentiated function of adult rat alveolar type II cells in vitro.

Rapid ex vivo expansion of human umbilical cord hematopoietic progenitors using a novel culture system.

Cell numbers limit the widespread clinical use of cord blood (CB) for gene therapy and marrow replacement in adults; a simple and effective method for ex vivo expansion of CB primitive progenitor cells (PPC) is required. Recently, the combination of thrombopoietin (TPO) and Flk-2/Flt-3 ligand (FL-2) was reported to support slow proliferation of CB-PPC in stroma-free liquid culture. We established a novel culture system in which the murine stromal cell line HESS-5 dramatically supports the rapid expansion of cryopreserved CB-PPC in synergy with TPO/FL-2. Furthermore, while HESS-5 cells directly adhered to human progenitors during culture, the cultured human cells could easily be harvested without contamination by HESS-5 cells. Within 7 days of culture, a 100-fold increase in CD34bright/CD38dim cells was obtained in serum-containing culture. When HESS-5 cells were physically separated from human progenitor cells in the presence of TPO/FL-2, synergy was blocked, suggesting that HESS-5 cells support proliferation of PPC by direct cell-to-cell interaction. The hematopoietic-supportive effects of this xenogeneic coculture system were then assessed in a very short-term (5 days) serum-free culture. Expansion was further enhanced by addition of stem cell factor (SCF) or interleukin-3 (IL-3). As a result, a 50- to 100-fold increase in CD34bright/CD38dim cells was noted. Colony-forming units in culture (CFU-C) and mixed colonies (CFU-GEMM) were enhanced by 10- to 30-fold and 10- to 20-fold, respectively. Moreover, generation of long-term-culture-initiating cells (LTC-IC) from CD34bright/CD38dim cells was amplified by 25-fold. The severe-combined immunodeficient (SCID) mouse-repopulating cell (SRC) assay confirmed extensive ability of the expanded cells to reconstitute long-term hematopoiesis. These results indicate that this xenogeneic coculture system, in combination with human cytokines, can rapidly generate PPC from cryopreserved CB.

The mouse/human cross-species heterodimer of leucine-rich repeat kinase 2: possible significance in the transgenic model mouse of Parkinson's disease.

Leucine-rich repeat kinase (LRRK2) is the causal molecule of autosomal dominant Parkinson's disease (PD). We previously reported that intracellular degradation of wild-type (WT) LRRK2 is promoted by formation of heterodimers with the I2020T mutant LRRK2. In the present study, we investigated whether this is also the case for mouse/human cross-species heterodimers, which could be formed in transgenic mice. First, by co-transfection and immunoprecipitation, we identified the cross-species heterodimer of mouse LRRK2 and human LRRK2. Next, we found that the protein level of mouse LRRK2 decreased when co-transfected with human I2020T LRRK2, but not with human WT LRRK2. These results suggested that degradation of mouse LRRK2 was promoted by formation of a cross-species heterodimer with the mutant LRRK2. In I2020T LRRK2-transgenic mice, the lower protein level of brain LRRK2 in comparison with control mice, together with higher expression of the mRNA, suggested that endogenous LRRK2 was degraded by formation of cross-species heterodimers. Our results suggest a new concept of cross-species dimer/oligomer formation in transgenic disease-model mice.

Frequency of provoked coronary vasospasm in patients undergoing coronary arteriography with spasm provocation test of acetylcholine.

This study examines the incidence of spasm by intracoronary injection of acetylcholine in Japanese patients who underwent coronary angiography. The subjects were 685 consecutive patients (477 men, mean age 63.2 +/- 7.5 years) who were studied with an acetylcholine test. Acetylcholine was injected in incremental doses of 20, 50, and 80 microg into the right coronary artery and 20, 50, and 100 microg into the left coronary artery. Spasm was defined as total or subtotal occlusion. Coronary vasospasm was determined in 221 patients (32.3%). Spasm occurred often during effort and rest in patients with angina (25 of 51, 49.0%), exertional angina (25 of 74, 33.8%), recent myocardial infarction (30 of 80, 37.5%), healed myocardial infarction (14 of 37, 37.8%), and especially in patients with rest angina (83 of 124, 66.9%), whereas spasm was relatively uncommon in patients with nonischemic heart disease (23 of 252, 9.1%). Spasm was superimposed on significant atherosclerotic lesions in 35.9% of patients as well as on nonfixed atherosclerotic lesions in 30.8% of patients. We conclude that >9% of Japanese patients may have coronary vasospasm with intracoronary injection of acetylcholine and recommend the provocation test for evaluating coronary vasospasm if coronary angiography is undertaken.

Major complications during spasm provocation tests with an intracoronary injection of acetylcholine.

This study sought to clarify major complications associated with acetylcholine testing. Serious major complications, such as sustained ventricular tachycardia, shock, and cardiac tamponade were determined in 4 of 715 patients (0.56%), but no cases of death or irreversible complications occurred. The spasm provocation test using acetylcholine should be performed carefully, although it is considered a safe and reliable method.

Clinical significance of granulocyte colony-stimulating factor (G-CSF) receptor expression in acute myeloid leukemia.

We examined granulocyte colony-stimulating factor (G-CSF) receptor (GR) expression on leukemic cells from 44 adults with newly-diagnosed acute myeloid leukemia (AML). GR expression was higher in female patients. G-CSF was administered to AML patients after initial induction therapy without significant acceleration of leukemia, irrespective of GR expression level. G-CSF administration after initial chemotherapy did not adversely influence clinical outcome of GR-positive patients. However, at first relapse, leukemia regrowth was accelerated in 3 of 15 GR-positive patients who received G-CSF after re-induction. It remains to be determined whether leukemia acceleration due to G-CSF contributes to re-induction failure and if G-CSF therapy is a significant risk in relapsed, GR-positive AML patients.

Flow cytometric analysis of cell-surface antigen expressions on acute myeloid leukemia cell populations according to their cell-size.

Acute myeloid leukemia (AML) cells which expanded from a single leukemic cell show certain degrees of morphological and biological heterogeneity. In the present study, we determined cell-surface antigen expressions (CD13, 33, 34 and 38, and HLA-DR) on AML cells based on their cell-size (large vs small cells) by flow cytometry. We found that the cell-surface antigens were more strongly expressed on the large leukemic cells than the small cells, regardless of FAB subtypes. Furthermore, our preliminary study demonstrated that AML patients who showed a relatively small difference in antigen expression between large and small leukemic cells had longer remission durations and survival periods, compared with those with a more prominent difference in antigen expression. Thus, the heterogeneity of AML cells determined by the combination of cell-surface antigen expressions and cell-size may be associated with clinically important biological behaviors.

Unusual relapse of adult T-cell leukemia/lymphoma after spontaneous remission.

A 42-year-old man was diagnosed with acute adult T-cell leukemia/lymphoma (ATL/L). Abnormal peripheral blood cells (45% of white blood cells) (Fig. 1a), hypercalcemia, and systemic lymphadenopathy were observed. Flow cytometric analysis (FCM) using peripheral mononuclear cells (PMNC) revealed that the immunophenotype of tumor cells was CD4+ CD8- CD25+ CD45RA- CD45RO+. Nevertheless, he developed a spontaneous remission 6 months later. At remission, the number of CD4-, CD25-, and CD45RO-positive cells decreased, while CD8- and CD45RA-positive cells increased to normal levels as previously reported by Suzuki et al. [1]. He was then referred to the outpatient clinic where he was periodically evaluated and received no therapy. Because of a serious sense of fullness he was re-admitted 30 months after diagnosis. Physical examination revealed ascites and small lymphadenopathy in the right axilla. Atypical lymphoid cells were not observed on microscopic examination of the blood smear. FCM using PMNC revealed that CD4+ CD25+ cells (3%) were within the normal range. Serum calcium was also within the normal range. Abdominal ultrasound examination showed massive ascites. Paracentesis demonstrated that the ascitic fluid had a high white blood cell count (3.15 x 10(9)/l) with a marked increase in abnormal large cells (Fig. 1b). FCM using mononuclear cells in the fluid revealed that 87.3% of the cells were double-positive for CD4 and CD25. Southern blot analysis of the cells confirmed monoclonal integration of human T-lymphotropic virus type 1 (HTLV-1) proviral DNA. The integrated genome was considered to be identical with that detected at initial presentation (Fig. 2). A diagnosis of relapsed ATL/L, with the same clone as was detected at initial diagnosis, was made. Although he was treated with cytotoxic drugs, he did not respond and he died of renal failure 1 month after relapse. Autopsy revealed nodular invasive lesions at the rectovesical pouch, omentum, diaphragm, and pericardium with peritoneal dissemination.

Clinical significance of LEA-1 expression in adult acute myeloid leukemia.

In this study, we examined expressions of several adhesion molecules (AdMs), i.e. leukocyte function antigen-1 (LFA-1: CD11a/CD18), Hermes homing receptor (CD44) and intercellular adhesion molecule-1 (ICAM-1: CD54), on leukemia cells from 51 adult patients with newly diagnosed acute myeloid leukemias (AMLs) to elucidate clinical significance of these AdM expressions. Those expressions in lymphoid malignancies have been correlated with tumor evolutions, but CD44 was detected in all the AML cases examined and CD54 expression did not associate with their clinical characteristics or outcomes. However, we found that LFA-1 expressions significantly correlated with splenomegaly, resistance to induction chemotherapies and short survival periods in AML patients.

Usefulness of accelerated exercise following mild hyperventilation for the induction of coronary artery spasm : comparison with an acetylcholine Test.

STUDY OBJECTIVES: This study was performed to compare the results of accelerated exercise following mild hyperventilation and a standard acetylcholine (ACh) test for the induction of coronary artery spasm in patients with drug-induced coronary artery spasm. METHODS AND RESULTS: The subjects were 74 patients with angiographically confirmed coronary artery spasm who were examined using accelerated exercise (ie, exercise that was accelerated every minute according to the protocol of Bruce and Horsten) following mild hyperventilation and who were not receiving any medication. ACh was injected in incremental doses of 20 microg and 50 microg into the right coronary artery and incremental doses of 20 microg, 50 microg, and 100 microg into the left coronary artery. Positive coronary spasm was defined as > or =99% luminal narrowing. Accelerated exercise following a mild hyperventilation test was as useful for detecting evidence of ischemia as was an ACh test (48 patients [64.9%] vs 49 patients [66.2%], respectively; not significant). No difference was observed between ischemic changes on ECG as a result of the newly combined method and the occurrence of ACh-induced spasm. ACh-induced coronary vasospasm occurred in 61 patients (82.4%). In the remaining 13 patients, intracoronary administration of ergonovine provoked coronary spasms. No serious irreversible complications were detected as a result of this newly combined method. CONCLUSIONS: The effectiveness of our newly combined procedure is equivalent to that of an ACh test to diagnose patients with coronary artery spasm.

Infection of left atrial thrombus associated with mitral stenosis: A case report.

We describe the first reported case of an infected left atrial thrombus. The case of the 65-year-old male patient in this report was associated with mitral stenosis and involved Escherichia coli, and was treated successfully with surgical resection of the infected thrombus. This case suggests that such infection should be considered as a possible complication of intracardiac thrombus when bacteremia is present.

Multivariate analysis of risk factors for hemorrhagic cystitis after hematopoietic stem cell transplantation.

To establish the most appropriate prophylactic therapy and risk factors for predicting hemorrhagic cystitis (HC) after stem cell transplantation (SCT), we retrospectively analyzed the clinical records of 450 transplant patients treated from 1982 to 2002. In all, 81 patients developed early- and/or late-onset HC (early=29, late=48, both=4). For the incidence of early-onset HC, administration of cyclophosphamide (CY) (p=0.0079, odds ratio (OD)=5.109, 95% confidence interval (CI)=1.533-17.030), busulfan (BU) (p=0.0015, OD=3.336, 95% CI=1.584-7.027), BU+CY (p=0.0001, OD=4.369, 95% CI=2.055-9.292), antithymocyte globulin (p=0.0009, OD=3.368, 95% CI=1.642-6.911), nonradiation (p=0.0163, OD=2.564, 95% CI=0.181-0.841), 2-mercaptoethane sodium sulfonate (Mesna) (p=0.0001, OD=7.519, 95% CI=2.847-19.858), and bladder irrigation (p=0.0001, OD=4.950, 95% CI=2.328-10.523) were risk factors. By Fisher's exact test, the combination of BU and Mesna was a more significant risk factor (P<0.001) than Mesna alone (p=0.008) compared to the administration of neither agent. By multivariate analysis, prophylactic administration of Mesna (p=0.0105, OD=5.301, 95% CI=1.477-19.026) and bladder irrigation (p=0.0001, OD=9.469, 95% CI=3.872-23.156) were significant risk factors of early-onset HC. We conclude that (i). high-dose BU as well as CY is a cause of HC, (ii). protective bladder irrigation has an opposite effect, and (iii). Mesna possibly has a toxic effect on bladder mucosa.