The effects of acute normovolaemic haemodilution on peri-operative coagulation in total hip arthroplasty

Total hip arthroplasty results in substantial blood loss in the peri-operative period. We evaluated the effects of acute normovolaemic haemodilution on blood coagulation and platelet function in 11 patients undergoing total hip arthroplasty. We performed acute normovolaemic haemodilution and haematological tests, rotational thromboelastometry (ROTEM(®) ) and whole-blood impedance aggregometry. Blood samples were obtained at three time points: (i) before the initiation of acute normovolaemic haemodilution; (ii) 20 min after completion of acute normovolaemic haemodilution; and (iii) 20 min after retransfusion. After acute normovolaemic haemodilution, ROTEM parameters demonstrated hypocoagulability. Clot formation time of INTEM was increased by 31.6% (p = 0.016), whereas the α-angle and maximum clot formation of INTEM decreased by 8.1% (p = 0.032) and 3.0% (p = 0.013) respectively, compared with baseline values. Clotting time and clot formation time of EXTEM were increased by 40.8% (p = 0.042) and 31.3% (p = 0.016), respectively, whereas the α-angle and maximum clot formation of EXTEM were decreased by 11.9% (p = 0.020) and 9.5% (p = 0.013), respectively. The maximum clot formation of FIBTEM decreased by 35.1% compared with the baseline value (p = 0.007). Following retransfusion, ROTEM values returned to baseline; clot formation time decreased and the α-angle and maximum clot formation increased. There were no significant changes in platelet aggregation during the study. At 20 min after the end of acute normovolaemic haemodilution, the international normalised ratio of prothrombin time was increased compared with the baseline value (p = 0.003). We conclude that acute normovolaemic haemodilution resulted in a hypocoagulable state compared with baseline values and that coagulation parameters returned to normal after retransfusion.

Prediction of pathological complete response of breast cancer patients undergoing neoadjuvant chemotherapy: usefulness of breast MRI computer-aided detection

OBJECTIVE

To evaluate the usefulness of MR computer-aided detection (CAD) in patients undergoing neoadjuvant chemotherapy for prediction of the pathological complete response of tumours.

METHODS

148 patients with breast cancer (mean age, 47.3 years; range, 29-72 years) who underwent neoadjuvant chemotherapy were included in our study. They underwent MRI before and after neoadjuvant chemotherapy, and we reviewed the pathological result as the gold standard. The computer-generated kinetic features for each lesion were recorded, and the features analysed included "threshold enhancement" at 50% and 100% minimum thresholds; degree of initial peak enhancement; and enhancement profiles comprising lesion percentages of washout, plateau and persistent enhancement. The final pathological size and character of tumours were correlated with post-chemotherapy mammography, ultrasonography and MR CAD findings. Kruskal-Wallis test and intraclass correlation coefficient were used to analyse the findings.

RESULTS

We divided the 148 patients into complete pathological response and non-complete pathological response groups. A complete pathological response was defined as no histopathological evidence of any residual invasive cancer cells in the breast or axillary lymph nodes. 39 patients showed complete pathological response, and 109 patients showed non-complete pathological response. Between enhancement profiles of MR CAD, plateau proportion of tumours was significantly correlated with the pathological response of tumours (mean proportion of plateau on complete pathological response group was 27%, p = 0.007).

CONCLUSION

When plateau proportion of tumours is high, we can predict non-complete pathological response of neoadjuvant chemotherapy.

ADVANCES IN KNOWLEDGE

MR CAD can be a useful tool for the assessment of response to neoadjuvant chemotherapy and prediction of pathological results.

Crucial role of calbindin-D28k in the pathogenesis of Alzheimer's disease mouse model

Calbindin-D_28k (CB), one of the major calcium-binding and buffering proteins, has a critical role in preventing a neuronal death as well as maintaining calcium homeostasis. Although marked reductions of CB expression have been observed in the brains of mice and humans with Alzheimer disease (AD), it is unknown whether these changes contribute to AD-related dysfunction. To determine the pathogenic importance of CB depletions in AD models, we crossed 5 familial AD mutations (5XFAD; Tg) mice with CB knock-out (CBKO) mice and generated a novel line CBKO·5XFAD (CBKOTg) mice. We first identified the change of signaling pathways and differentially expressed proteins globally by removing CB in Tg mice using mass spectrometry and antibody microarray. Immunohistochemistry showed that CBKOTg mice had significant neuronal loss in the subiculum area without changing the magnitude (number) of amyloid β-peptide (Aβ) plaques deposition and elicited significant apoptotic features and mitochondrial dysfunction compared with Tg mice. Moreover, CBKOTg mice reduced levels of phosphorylated mitogen-activated protein kinase (extracellular signal-regulated kinase) 1/2 and cAMP response element-binding protein at Ser-133 and synaptic molecules such as N-methyl-D-aspartate receptor 1 (NMDA receptor 1), NMDA receptor 2A, PSD-95 and synaptophysin in the subiculum compared with Tg mice. Importantly, this is the first experimental evidence that removal of CB from amyloid precursor protein/presenilin transgenic mice aggravates AD pathogenesis, suggesting that CB has a critical role in AD pathogenesis.

Tonicity-responsive enhancer binding protein haplodeficiency attenuates seizure severity and NF-κB-mediated neuroinflammation in kainic acid-induced seizures

Kainic acid (KA)-induced seizures followed by neuronal death are associated with neuroinflammation and blood-brain barrier (BBB) leakage. Tonicity-responsive enhancer binding protein (TonEBP) is known as a transcriptional factor activating osmoprotective genes, and in brain, it is expressed in neuronal nuclei. Thus dysregulation of TonEBP may be involved in the pathology of KA-induced seizures. Here we used TonEBP heterozygote (+/-) mice to study the roles of TonEBP. Electroencephalographic study showed that TonEBP (+/-) mice reduced seizure frequency and severity compared with wild type during KA-induced status epilepticus. Immunohistochemistry and western blotting analysis showed that KA-induced neuroinflammation and BBB leakage were dramatically reduced in TonEBP (+/-) mice. Similarly, TonEBP-specific siRNA reduced glutamate-induced death in HT22 hippocampal neuronal cells. TonEBP haplodeficiency prevented KA-induced nuclear translocation of NF-κB p65 and attenuated inflammation. Our findings identify TonEBP as a critical regulator of neuroinflammation and BBB leakage in KA-induced seizures, which suggests TonEBP as a good therapeutic target.

Simple and easy DNA mapping method using peptide nucleic acid (PNA) tagging

In this paper, we introduce a simple and easy DNA mapping method using peptide nucleic acid (PNA) on glass cover-slips based on optical detection. PNA and glass cover-slips were used as easy tagging and stretching method, separately. The PNA can be invaded lambda (A) DNA at the sequences we wished to tag without any additional materials. Alexa-488 fluorophore-conjugated PNA was designed to invade at four sites (sequence: AAGAAGAA) of lambda DNA with robust and exact binding. Fluorophore tagged lambda DNA was stretched in electrical layer coated glass cover-slips. The lambda DNA was stretched as 9.2 um in length. It is approximately 60% of theoretical length of lambda DNA and sufficient length to promise optical resolution. The sites of desired sequence tagged by PNA were well detected in stretched lambda DNA.

Temporal variation of volatile organic compounds and their major emission sources in Seoul, Korea

This study examines the characteristics of volatile organic compounds (VOCs) and their major emission sources at the Bulgwang site in Seoul, Korea. The annual levels of VOCs (96.2-121.1 ppb C) have shown a decreasing trend from 2004 to 2008. The most abundant component in Seoul was toluene, which accounted for over 23.5 % of the total VOCs on the parts per billion on a carbon basis, and the portions of alkanes with two to six carbons constituted the largest major lumped group, ranging from 40.1 to 48.4 % (45.3 ± 3.7 %) of the total VOCs. Major components of the solvent (toluene, m/p-xylene, o-xylene, and ethylbenzene) showed high in daytime and summer and low in nighttime and winter due mainly to the variation of the ambient temperature. The species mostly emitted from gasoline vapor (i/n-butane, i/n-pentane, n-hexane, and 2-methylpentane) and vehicular exhaust (ethylene, acetylene, and benzene) showed bimodal peaks in the diurnal variation around the commuting hours because of the high traffic volume. For the 14 out of 15 highest concentration species, the weekend effect was only evident on Sundays because of the stepwise implementation of the 5-day work-week system. Principal components analysis (PCA) was applied in order to identify the sources of the 15 highest concentration VOCs and, as a result, three principal components such as gasoline vapor (48.9 %), vehicular exhaust (17.9 %), and evaporation of solvents (9.8 %) were obtained to explain a total of 76.6 % of the data variance. Most influential contributing sources at the sampling site were traffic-related ones although the use of solvent was the dominant emission source based on the official emission inventory.

Deformation of a Peregrine soliton by fluctuating backgrounds

A generalized Peregrine soliton moving on a fluctuating background is constructed. The agreement with the experimental results is improved compared to the standard Peregrine soliton. It has a deformed shape asymmetric with respect to time, and the peak values are not always 3.

Assessment of extent of breast cancer: comparison between digital breast tomosynthesis and full-field digital mammography

AIM

To compare the accuracy of digital breast tomosynthesis (DBT) and full-field digital mammography (FFDM) in preoperative assessment of local extent of breast cancer.

MATERIALS AND METHODS

Lesion sizes of breast cancers on DBT and FFDM images were independently evaluated by breast radiologists. Each lesion was flagged as either mis-sized or not depending on whether the assessment of size at imaging was within 1 cm of the lesion size at surgery. Additional analyses were made by mammographic parenchymal density and by lesion size, using 2 cm as the boundary to separate the two subgroups. Statistical comparisons were performed using a repeated measures linear model on the percent mis-sized. P-values < 0.05 were considered statistically significant.

RESULTS

The dataset included 173 malignant breast lesions (mean size 23.8 mm, 43% of lesions were ≤2 cm in size) in 169 patients, two-thirds of which had heterogeneously or extremely dense breasts. Overall, the percentage of lesions mis-sized at DBT was significantly lower than at FFDM (19% versus 29%, p = 0.003). There was significantly less mis-sizing at DBT in both heterogeneously dense breasts (11.1% difference between DBT and FFDM, p = 0.016) and extremely dense breasts (15.8% difference, p = 0.024). DBT also had significantly less mis-sizing than FFDM in the subgroup of lesions that were ≤2 cm in size (14.7% difference, p = 0.005).

CONCLUSION

DBT was significantly superior to FFDM for the evaluation of lesion size overall, and specifically for small lesions and for lesions in dense breasts. The superiority of DBT versus FFDM increased with parenchymal density.

Evaluation of the optimum volatile organic compounds control strategy considering the formation of ozone and secondary organic aerosol in Seoul, Korea

The characteristics of volatile organic compounds (VOCs) and their annual trends in Seoul, Korea were investigated, with their optimal control strategy suggested. The annual concentration of VOCs (96.2-121.1 ppbC) has shown a decreasing trend from 2004 to 2008, suggesting the control strategy via the "Special Measures for Metropolitan Air Quality Improvement," which was implemented in 2005, has been successful. The contributions of individual VOC to the production of ambient ozone and secondary organic aerosol (SOA) are discussed to assess the adequacy of current control strategies. The contribution of aromatics (C6-C10) to the production of ozone accounted for 38.7-46.3 % of the total ozone production, followed by low carbon alkanes (C2-C6) (27.0-35.9 %). The total SOA formation potential of VOCs was found to range from 2.5 to 3.5 μg m(-3), mainly as a result of aromatics (C6-C10) (over 85 %). Considering the contributions from ozone and SOA production, it was concluded that solvent use was the most important emission source, followed by vehicle exhaust emissions. Thus, the current emission control strategy focused on these two emission sources is appropriate to reduce the VOCs related pollution level of the Seoul Metropolitan Region. Still, an additional control strategy, such as controlling the emissions from meat cooking, which is an emission source of high carbon alkanes (C7-C10), needs to be considered to further reduce the VOCs related pollution level in Seoul.

Inter-individual variability in OCT1 expression and its relationship with OCT1 genotype in liver samples from a Korean population

To clarify inter-individual variation in the expression of organic cation transporter 1 (OCT1), the levels of OCT1 mRNA and protein from 65 human liver samples were examined by real-time PCR and Western blot analysis and were associated with OCT1 genotypes. The expression levels of OCT1 mRNA and protein in 65 liver samples of Korean origin were not normally distributed and varied by 23.6- and 15.9-fold, respectively. OCT1 mRNA expression was correlated with OCT1 protein expression with a correlation coefficient of 0.641 (p < 0.0001). However, non-genetic factors, such as age, gender, and cholestasis, were not significantly associated with OCT1 expression. When quantitative expression levels were compared in relation to OCT1 promoter SNPs, there was no significant difference in OCT1 expression levels among the -1795 GG, GA, and AA genotypes. Moreover, expression levels of OCT1 were not changed in relation to the -1756 genotypes. Inter-individual variation in OCT1 mRNA and protein expression levels in the liver did not correlate with OCT1 genotypes or non-genetic factors, such as age, gender, and cholestasis. These results suggest that genetic and non-genetic factors may not be a significant contributing factor of variations in OCT1 expression from liver samples of Korean origin.

P5-08-06: Comparison of Mammographic Density between Ductal Carcinoma In Situ and Benign Breast Disease

Background: High breast density is an independent risk factor for breast cancer as well as benign breast diseases. However there are few studies about breast density of ductal carcinoma in situ (DCIS) and benign breast disease(BBD). In this study, we investigated patterns of breast density of DCIS and BBD, and comparatively analyzed breast densities of DCIS and BBD.

Material and Methods From 2008 to 2009, 345 patients underwent surgery for DCIS at Asan Medical Center, and 295 patients for BBD at 2010. We retrospectively reviewed each groups and estimated cranio-caudal view of digital mammogram of unaffected breast by computer-assisted thresholding methods, using Cumulus 4, version 4.0. For BBD we included atypical ductal hyperplasia, fibroadenoma, papilloma(atypical/intraductal), phyllodes tumor(benign/borderline), and excluded unavailable mammogram(mostly, because of scanned films from outside hospitals and previously diagnosed breast cancer).

Results Mean ages of each group were 46.51 year old in DCIS group and 41.43 year old in BBD group, and the mean percentage density(PD) were 44.89% and 45.27%, respectively.

Interactions of urate transporter URAT1 in human kidney with uricosuric drugs

AIM

Hyperuricaemia is a significant factor in a variety of diseases, including gout and cardiovascular diseases. The kidney plays a dominant role in maintaining plasma urate levels through the excretion process. Human renal urate transporter URAT1 is thought to be an essential molecule that mediates the reabsorption of urate on the apical side of the proximal tubule. In this study the pharmacological characteristics and clinical implications of URAT1 were elucidated.

METHODS

Madin-Darby canine kidney (MDCK) cells stably expressing URAT1 (MDCK-URAT1) were established and examined the interactions of URAT1 with various drugs such as benzbromarone and its metabolites including 6-hydroxybenzbromarone, angiotensin-converting enzyme inhibitors, non-steroidal anti-inflammatory drugs and urate transport inhibitors including E3040 and probenecid.

RESULTS

MDCK-URAT1 cells exhibited a time- and dose-dependent increase in urate uptake, with a Km value of 570.7 µmol/L. When an URAT1-green fluorescent protein fusion protein construct was expressed in MDCK cells, the protein was sorted mainly to the apical side of the membrane. The drugs except for captoril dose-dependently inhibited urate uptake mediated by URAT1, with half maximal inhibitory concentration (IC(50) ) values ranging 0.05-716 µmol/L.

CONCLUSION

Comparing these IC(50) values with intratubular concentrations of unbound drugs in humans, it is thought that URAT1 is a target molecule of uricosuric drugs, including 6-hydroxybenzbromarone, probenecid, indomethacin and salicylate, to inhibit urate reabsorption in vivo. In addition, a cell line that stably expressing URAT1 could be a useful tool for the development of uricosuric drugs.

The analgesic effect of remifentanil on prevention of withdrawal response associated with the injection of rocuronium in children: no evidence for a peripheral action

Remifentanil pre-treatment has been reported to decrease the incidence of rocuronium injection-associated withdrawal movement. This study was designed to explore the site of action of remifentanil for reducing withdrawal response during rocuronium injection in children. Ninety-six paediatric patients were randomly assigned to three groups. After induction of anaesthesia with 5 mg/kg 2.5% thiopental sodium, 2 ml saline (placebo group) or 0.5 microg/kg remifentanil (group R), was injected intravenously 1 min before 0.6 mg/kg rocuronium. In a third group (group R'), the venous retention of 0.5 microg/kg remifentanil was maintained for 30 s followed by tourniquet release and injection of 0.6 mg/kg rocuronium. Withdrawal response was graded using a four-point scale. The incidence of withdrawal movement after rocuronium administration was 94%, 22% and 81% in the placebo, R, and R' groups, respectively. This study demonstrated that the pre-treatment effect of remifentanil for reducing rocuronium-associated withdrawal response occurs mainly through a central action.

Comparison of mammography, sonography, MRI and clinical examination in patients with locally advanced or inflammatory breast cancer who underwent neoadjuvant chemotherapy

OBJECTIVES

The purpose of this study was to determine the relative accuracies of mammography, sonography, MRI and clinical examination in predicting residual tumour size and pathological response after neoadjuvant chemotherapy for locally advanced or inflammatory breast cancer. Each prediction method was compared with the gold standard of surgical pathology.

METHODS

43 patients (age range, 25-62 years; mean age, 42.7 years) with locally advanced or inflammatory breast cancer who had been treated by neoadjuvant chemotherapy were enrolled prospectively. We compared the predicted residual tumour size and the predicted response on imaging and clinical examination with residual tumour size and response on pathology. Statistical analysis was performed using weighted kappa statistics and intraclass correlation coefficients (ICC).

RESULTS

The ICC values between predicted tumour size and pathologically determined tumour size were 0.65 for clinical examination, 0.69 for mammography, 0.78 for sonography and 0.97 for MRI. Agreement between the response predictions at mid-treatment and the responses measured by pathology had kappa values of 0.28 for clinical examination, 0.32 for mammography, 0.46 for sonography and 0.68 for MRI. Agreement between the final response predictions and the responses measured by pathology had kappa values of 0.43 for clinical examination, 0.44 for mammography, 0.50 for sonography and 0.82 for MRI.

CONCLUSION

Predictions of response and residual tumour size made on MRI were better correlated with the assessments of response and residual tumour size made upon pathology than were predictions made on the basis of clinical examination, mammography or sonography. Thus, the evaluation of predicted response using MRI could provide a relatively sensitive early assessment of chemotherapy efficacy.

Correlation between mammographic and sonographic findings and prognostic factors in patients with node-negative invasive breast cancer

OBJECTIVES

The purpose of this study was to correlate sonographic and mammographic findings with prognostic factors in patients with node-negative invasive breast cancer.

METHODS

Sonographic and mammographic findings in 710 consecutive patients (age range 21-81 years; mean age 49 years) with 715 node-negative invasive breast cancers were retrospectively evaluated. Pathology reports relating to tumour size, histological grade, lymphovascular invasion (LVI), extensive intraductal component (EIC), oestrogen receptor (ER) status and HER-2/neu status were reviewed and correlated with the imaging findings. Statistical analysis was performed using logistic regression analysis and intraclass correlation coefficient (ICC).

RESULTS

On mammography, non-spiculated masses with calcifications were associated with all poor prognostic factors: high histological grade, positive LVI, EIC, HER-2/neu status and negative ER. Other lesions were associated with none of these poor prognostic factors. Hyperdense masses on mammography, the presence of mixed echogenicity, posterior enhancement, calcifications in-or-out of masses and diffusely increased vascularity on sonography were associated with high histological grade and negative ER. Associated calcifications on both mammograms and sonograms were correlated with EIC and HER-2/neu overexpression. The ICC value for the disease extent was 0.60 on mammography and 0.70 on sonography.

CONCLUSION

Several sonographic and mammographic features can have a prognostic value in the subsequent treatment of patients with node-negative invasive breast cancer. Radiologists should pay more attention to masses that are associated with calcifications because on both mammography and sonography associated calcifications were predictors of positive EIC and HER-2/neu overexpression.

Immunoglobulin D multiple myeloma: response to therapy, survival, and prognostic factors in 75 patients

BACKGROUND

To analyze the clinical features, outcomes including efficacy of treatment, and prognostic factors of patients with immunoglobulin D multiple myeloma (IgD MM).

DESIGN AND METHODS

Seventy-five patients diagnosed with IgD MM were selected from the Korean Myeloma Registry database (www.myeloma.or.kr).

RESULTS

Median age was 57 years and the main presenting features were bone pain (77%). Renal function impairment and hypercalcemia were present in 40 (53%) and 20 (27%) patients. Sixty-seven patients (89%) had lambda light chains. Forty-eight patients (64%) were of stage III by International Staging System. Twenty-six patients (53%) had chromosomal abnormalities mostly by conventional cytogenetics. Thirty-nine patients (54%) were treated with vincristine, adriamycin, and dexamethasone chemotherapy; the overall response rate (ORR) of 56%. Sixteen patients (22%) received first-line chemotherapy including new drugs (bortezomib or thalidomide), with an ORR of 81%. At a median follow-up time of 28.6 months, median overall survival (OS) was 18.5 months. Age, extramedullary plasmacytoma, del(13) or hypoploidy, serum β(2) microglobulin level, and platelet count were significant prognostic factors for OS.

CONCLUSIONS

IgD MM is an aggressive disease that is usually detected at an advanced stage. Despite a positive initial response, survival after relapse was dismal. Intensive treatment strategies before and following stem cell transplantation may improve outcomes in younger patients.

Time-resolved demagnetization of Co2MnSi observed using x-ray magnetic circular dichroism and an ultrafast streak camera

The demagnetization dynamics of the Heusler alloy Co(2)MnSi was studied using picosecond time-resolved x-ray magnetic circular dichroism. The sample was excited using femtosecond laser pulses. In contrast to the sub-picosecond demagnetization of the metal ferromagnet Ni, substantially slower demagnetization with a time constant of 3.5 ± 0.5 ps was measured. This could be explained by a spin-dependent band gap inhibiting the spin-flip scattering of hot electrons in Co(2)MnSi, which is predicted to be half-metallic. A universal demagnetization time constant was measured across a range of pump power levels.

Early onset of acute GVHD indicates worse outcome in terms of severity of chronic GVHD compared with late onset

Acute GVHD (aGVHD) is an important risk factor for predicting the incidence or severity of chronic GVHD (cGVHD). Transplant outcome can be influenced by the onset time of aGVHD in patients who have received allogeneic PBSC transplants (PBSCTs). The medical records of 134 patients who survived more than 3 months after myeloablative allogeneic PBSCT were retrospectively reviewed. In all, 38 patients (28.4%) developed grade II-IV aGVHD before day +28 (early aGVHD) and 25 patients (18.7%) after day +28 (late aGVHD). The 5-year cumulative incidence of cGVHD was 78.9% in the early-aGVHD group and 56.6% in the late-aGVHD group (P=0.034). The 5-year OS was 51.0% for the early-aGVHD and 80.8% for the late-aGVHD group (P=0.406). Infection was the primary cause of death for the early-aGVHD group (51.4 vs 16.7%, P=0.017), whereas relapse of the primary disease was higher among the patients with late aGVHD, although this was statistically insignificant (58.3 vs 25.7%, P=0.309). In a multivariate analysis, early aGVHD was identified as a risk factor for developing cGVHD (hazard ratio (HR) 2.278, P=0.004). The development of aGVHD early after allogeneic PBSCT increased the risk of cGVHD and infection-related death rate when compared with the late onset of aGVHD.

Surface property change of graphene using nitrogen ion

We introduced nitrogen ions to modify the graphene surface and its property changes were investigated. A graphene layer grown on 6H-SiC(0001) was irradiated with 100 eV nitrogen ions. Surface property changes were studied using photoemission spectroscopy (PES), near edge x-ray adsorption spectroscopy (NEXAFS), and atomic force microscopy(AFM). N 1s core level spectra show that three kinds of nitrogen species, nitrogen gas, graphite-like and pyridine-like nitrogen were induced on the nitrogen ion implanted graphene surface.

Genetic variants of organic cation transporter 2 (OCT2) significantly reduce metformin uptake in oocytes

1. The authors sought to evaluate the contribution of organic cation transporters (OCTs) to the renal tubular transport of metformin using LLC-PK1 cells as an in vitro model for the renal proximal tubule, and to investigate the effects of three non-synonymous genetic variants of OCT2 on the transport activity of metformin in vitro using an oocyte over-expression system. 2. The basolateral-to-apical transport of metformin was significantly greater than the apical-to-basolateral transport and showed concentration dependency with the kinetic parameters: maximum transport rate (V(max)), 922 pmol min(-1) per 5 x 10(5) cells; Michaelis-Menten constant (K(m)), 393 microM; intrinsic clearance (CL(int)), 2.35 microl min(-1) per 5 x 10(5) cells; and diffusion constant (K(d)), 0.33 microl min(-1) per 5 x 10(5) cells. The basolateral-to-apical transport of metformin was inhibited by phenoxybenzamine, an inhibitor of OCTs, but not by cyclosporine A, MK571, or fumitremorgin C, which are inhibitors of P-glycoprotein, multidrug resistance proteins (MRPs), and breast cancer resistance protein (BCRP), respectively, suggesting that OCTs play a role in renal tubular secretion of metformin. 3. Metformin uptake was much greater in oocytes expressing OCT2-wild type (OCT2-WT) than OCT1-WT compared with uptake in water-injected oocytes. Uptake was significantly decreased in oocytes expressing OCT2-T199I, -T201M, and -A270S compared with that in OCT2-WT, suggesting that metformin is a better substrate for OCT2 than for OCT1 and that the amino acid-substituted variants of OCT2 cause a functional decrease in metformin uptake. 4. In conclusion, the genetic variants of OCT2 (OCT2-T199I, -T201M, and -A270S) decreased the transport activity of metformin and thus may contribute to the inter-individual variation in metformin disposition as OCT2 plays a pivotal role in renal excretion, the major disposition route of metformin.

Genetic variants of the organic cation transporter 2 influence the disposition of metformin

Genetic variants of the organic cation transporter 2 (protein, OCT2; gene, SLC22A2) were evaluated for their contribution to the variations in the pharmacokinetics of metformin, especially to its renal elimination. Genetic variants of SLC22A2 (c.596C>T, c.602C>T, and c.808G>T) showed significant differences in metformin pharmacokinetics when compared with the reference genotype, with higher peak plasma concentration (C(max)) and area under the curve (AUC) and lower renal clearance (Cl(renal)), thereby suggesting that a decrease in transport function associated with the SLC22A2 variants results in reduced Cl(renal) of metformin and consequently leads to increased plasma concentrations.

Multicenter study of intravenous busulfan, cyclophosphamide, and etoposide (i.v. Bu/Cy/E) as conditioning regimen for autologous stem cell transplantation in patients with non-Hodgkin's lymphoma

The current study aimed to evaluate the efficacy and toxicity of a combination of intravenous busulfan, cyclophosphamide and etoposide (i.v. Bu/Cy/E) as a conditioning regimen prior to autologous hematopoietic stem cell transplantation in patients with non-Hodgkin's lymphoma (NHL). Sixty-four patients with relapsed/refractory (n=36) or high-risk (n=28) lymphoma were enrolled. The high-dose chemotherapy consisted of i.v. Bu (0.8 mg kg(-1) i.v. q 6 h from day -7 to day -5), Cy (50 mg kg(-1) i.v. on day -3 and day -2) and E (400 mg m(-2) i.v. on day -5 and day -4). The median age was 43 (range 18-65) years, and 39 patients were male. Diffuse large B-cell lymphoma (40.6%) was the most common histological subtype. All evaluable patients achieved an engraftment of neutrophils (median, day 12) and platelets (median, day 13). Hepatic veno-occlusive disease was observed in four patients (three mild, one moderate grade), and two patients (3.1%) died from treatment-related complications. At a median follow-up of 16.4 months, 15 patients (23.4%) exhibited a relapse or progression, while 13 patients (20.3%) had died of disease. The estimated 3-year overall and progression-free survival for all patients was 72.1 and 70.1%, respectively. In conclusion, the conditioning regimen of i.v. Bu/Cy/E was well tolerated and seemed to be effective in patients with aggressive NHL.