Crystal structure of mango α1,3/α1,4-fucosyltransferase elucidates unique elements that regulate Lewis A-dominant oligosaccharide assembly.

In various organisms, α1,3/α1,4-fucosyltransferases (CAZy GT10 family enzymes) mediate the assembly of type I (Galß1,3GlcNAc) and/or type II (Galß1,4GlcNAc)-based Lewis structures that are widely distributed in glycoconjugates. Unlike enzymes of other species, plant orthologues show little fucosyltransferase activity for type II-based glycans and predominantly catalyze the assembly of the Lewis A structure [Galß1,3(Fucα1,4)GlcNAc] on the type I disaccharide unit of their substrates. However, the structural basis underlying this unique substrate selectivity remains elusive. In this study, we investigated the structure-function relationship of MiFUT13A, a mango α1,3/α1,4-fucosyltransferase. The prepared MiFUT13A displayed distinct α1,4-fucosyltransferase activity. Consistent with the enzymatic properties of this molecule, X-ray crystallography revealed that this enzyme has a typical GT-B fold-type structure containing a set of residues that are responsible for its SN2-like catalysis. Site-directed mutagenesis and molecular docking analyses proposed a rational binding mechanism for type I oligosaccharides. Within the catalytic cleft, the pocket surrounding Trp121 serves as a binding site, anchoring the non-reducing terminal ß1,3-galactose that belongs to the type I disaccharide unit. Furthermore, Glu177 was postulated to function as a general base catalyst through its interaction with the 4-hydroxy group of the acceptor N-acetylglucosamine residue. Adjacent residues, specifically Thr120, Thr157 and Asp175 were speculated to assist in binding of the reducing terminal residues. Intriguingly, these structural elements were not fully conserved in mammalian orthologue which also shows predominant α1,4-fucosyltransferase activity. In conclusion, we have proposed that MiFUT13A generates the Lewis A structure on type I glycans through a distinct mechanism, divergent from that of mammalian enzymes.

Effects of human herpesvirus 6B reactivation on cognitive function in cord blood transplant recipients: a prospective multicenter study.

This prospective multicenter study aimed to determine the effects of human herpesvirus-6B (HHV-6B) reactivation on central nervous system (CNS) function in cord blood transplant (CBT) recipients. Our focus was to track HHV-6B reactivation and evaluate its association with delirium and cognitive function, specifically in the domains of verbal memory, attention/processing speed, and quality of life (QOL). A cohort of 38 patients participated in this study. Of the 37 patients evaluated, seven (18.9%) developed delirium, with six of these cases emerging after HHV-6B reactivation (median lag, 7 days). Evaluation of verbal memory showed that the final trial score for unrelated words at 70 days after transplantation was significantly lower than that before preconditioning (P = 0.004) among patients (n = 15) who experienced higher-level HHV-6B reactivation (median or higher maximum plasma HHV-6 DNA load for participating patients). Patients without higher-level reactivation did not show significant declines in verbal memory scores. QOL was assessed using the 36-item Short-Form Health Survey, and the social functioning score 1 year post-transplantation was significantly lower in patients who experienced higher-level HHV-6B reactivation than in those who did not. Our findings suggest that higher-level HHV-6B reactivation can detrimentally affect certain cognitive functions in CBT recipients.

Targeting Pancreatic Cancer with Novel Plumbagin Derivatives: Design, Synthesis, Molecular Mechanism, In Vitro and In Vivo Evaluation.

Pancreatic tumors grow in an "austerity" tumor microenvironment characterized by nutrient deprivation and hypoxia. This leads to the activation of adaptive pathways in pancreatic cancer cells, promoting tolerance to nutrition starvation and aggressive malignancy. Conventional anticancer drugs are often ineffective against tumors that grow in such austerity condition. Plumbagin, a plant-derived naphthoquinone, has shown potent preferential cytotoxicity against pancreatic cancer cells under nutrient-deprived conditions. Therefore, we synthesized a series of plumbagin derivatives and found that 2-(cyclohexylmethyl)-plumbagin (3f) was the most promising compound with a PC50 value of 0.11 µM. Mechanistically, 3f was found to inhibit the PI3K/Akt/mTOR signaling pathways, leading to cancer cell death under nutrient-deprived conditions. In vivo studies using pancreatic cancer xenograft mouse models confirmed the efficacy of 3f, demonstrating significant inhibition of tumor growth in a dose-dependent manner. Compound 3f represents a highly promising lead for anticancer drug development based on an antiausterity strategy.

Scoring Model to Predict a Low Disease Activity in Elderly Rheumatoid Arthritis Patients Initially Treated with Biological Disease-modifying Antirheumatic Drugs.

Objective We aimed to develop a scoring model to predict a low disease activity (LDA) in elderly rheumatoid arthritis (RA) patients initially treated with biological disease-modifying antirheumatic drugs (bDMARDs). Methods This retrospective cohort study included 82 elderly RA patients who initially received bDMARDs. The outcome was an LDA after bDMARDs initiation. We developed a predictive formula for an LDA using a multivariate analysis, the accuracy of which was assessed by the area under the curve (AUC) of the receiver operating characteristic curves; the scoring model was developed using the formula. For each factor, approximate odds ratios were scored as an integer, divided into three groups based on the distribution of these scores. In addition, the scoring model accuracy was assessed. Results The mean age was 73.5±6.0 years old, and 86.6% were women. An LDA was achieved in 43 patients (52.4%). The predictive formula for an LDA was prepared using six factors selected for the multivariable analysis: the neutrophil-to-lymphocyte ratio (NLR), anemia, the 28-joint disease activity score with erythrocyte sedimentation rate (DAS28-ESR), serum level of matrix metalloproteinase-3 (MMP-3), diabetes mellitus (DM), and rheumatoid factor (RF). The AUC for the formula was 0.829 (95% confidence interval, 0.729-0.930). The odds ratios of the six factors were scored (DAS28-ESR and serum MMP-3=1 point, NLR, anemia, DM, and RF=2 points) and divided into three groups (≤4, 5-7, and ≥8). The high-score group (≥8) achieved a positive predictive value of 83%. Conclusion The scoring model accurately predicted an LDA in elderly RA patients initially treated with bDMARDs.

Tamoxifen enhances romidepsin-induced apoptosis in T-cell malignant cells via activation of FOXO1 signaling pathway.

Although romidepsin as monotherapy appears to be useful for treating T-cell lymphoma, combined chemotherapy with other therapeutic agents is required for improvement of the treatment outcome. To establish safer and more effective regimens, systematic screening was conducted to identify suitable drugs to be used in combination with romidepsin for T-cell malignancies, and the underlying molecular mechanisms were examined. The most effective agent was tamoxifen. The combination of romidepsin and tamoxifen had a significant synergistic effect in inducing apoptosis. The growth-inhibitory effects of the combined treatment were reversed by α-tocopherol. FOXO1 expression was greatly upregulated in MOLT-4 cells treated with romidepsin plus tamoxifen. Knockdown of FOXO1 expression by siRNA significantly reduced the cell death induced by romidepsin plus tamoxifen. The combination of romidepsin and tamoxifen might be considered for the treatment of T-cell lymphoma patients.

Factors predicting addition of disease-modifying antirheumatic drugs after initial methotrexate monotherapy in patients with rheumatoid arthritis.

INTRODUCTION: We investigated factors predicting the addition of disease-modifying antirheumatic drugs (DMARDs) after an initial methotrexate (MTX) monotherapy in rheumatoid arthritis (RA) patients to support an early decision on the DMARDs addition. METHODS: This retrospective cohort study included 311 patients who were diagnosed with RA and started on MTX monotherapy at Showa University Hospital, Japan. The outcome was addition of DMARDs after an initial MTX monotherapy at 6 months. Baseline patient characteristics were compared between the DMARDs addition and MTX monotherapy continuation groups, and significant independent predictive factors for the addition of DMARDs were selected using multivariate analysis. RESULTS: The median age of patients was 62 years (range 24-90), 170 patients (73%) were women, the median swollen 28-joint count (SJC28) was 3 (0-28), and the median tender 28-joint count (TJC28) was 5 (0-28). DMARDs were added in 65 (27.9%) patients. In the univariate analysis, higher TJC28 and SJC28, concomitant use of nonsteroidal anti-inflammatory drugs, and intra-articular glucocorticoid (GC) injection history were significantly associated with the DMARDs addition. In the multivariate analysis, by adding covariates to the variables identified in the univariate analysis, SJC28 (odds ratio [OR] 1.390 per 5 joints increase; 95% confidence interval [CI], 1.036-1.866) and intra-articular GC injection history (OR 3.678; 95% CI, 1.170-11.557) were independent predictors of DMARDs addition. CONCLUSION: A higher SJC28 and intra-articular GC injection history may be useful predictors of DMARDs addition after the initial MTX monotherapy. We expect that using these predictors will enable an earlier shift to a more aggressive treatment. Key Points ・We performed a retrospective cohort study with the addition of DMARDs as the outcome in patients with RA who were started on MTX monotherapy. ・A higher SJC28 (OR 1.390; 95% CI, 1.036-1.866) and an intra-articular GC injection history (OR 3.678; 95% CI, 1.170-11.557) may be useful predictors for the addition of DMARDs of initiating MTX monotherapy at 6 months. ・The use of such indicators may support an early decision on the addition of DMARDs after the initial MTX monotherapy.

Differential gene expression analysis of dasatinib-induced colitis in a patient with chronic myeloid leukemia followed for 3 years: a case report.

BACKGROUND: Dasatinib is a second-generation tyrosine kinase inhibitor (TKI) developed for treatment of patients with chronic myeloid leukemia (CML). The drug has been shown to act as a potent multikinase inhibitor by blocking not only the BCR-ABL1 gene sequence but also the SRC kinase family, though unexpected adverse events such as pleural effusion have recently been reported in patients undergoing treatment with dasatinib. Hemorrhagic colitis is a unique gastrointestinal adverse events associated with dasatinib and its pathogenesis remains poorly understood. CASE PRESENTATION: We report here a case of dasatinib-induced asymptomatic colitis in a patient with CML, who showed no exacerbation in careful observations and maintained deep molecular response (DMR) during a 3-year period. In addition, we performed transcriptome analysis of inflamed colonic mucosa specimens to clarify the possible mechanism of colitis that develops in association with dasatinib administration. Our results demonstrated that differential gene expression, especially lymphocyte-associated genes and chemokines, is substantially involved in inflammation of colonic mucosa in affected patients. CONCLUSION: Dasatinib induces immune-mediated colitis following lymphocyte infiltration.

Simultaneous Discordant B-Lymphoblastic Lymphoma and Follicular Lymphoma.

OBJECTIVES: We report a rare case of B-lymphoblastic lymphoma (B-LBL) and low-grade follicular lymphoma (FL) identified concurrently in biopsies from different sites at the initial diagnosis in a 39-year-old man. The clonal relationship between the 2 histologic subtypes was investigated. METHODS: A diagnosis of FL grade 1/2 (low grade) was made by bone marrow (BM) biopsy. B-LBL was identified in biopsies from the testis and pancreas. Cytogenetic and molecular analyses were performed to investigate their clonal relationship. RESULTS: Interphase fluorescence in situ hybridization analyses and G-banding karyotype analyses identified the BCL2-IGH and MYC-IGH translocation in tumor cells from both the BM and testis. The tumor cells from the BM and testis shared the same IGH VDJ usage and a high degree of somatic mutations. These findings suggest that acquisition of MYC gene rearrangement is a critical event for lymphoblastic transformation of FL. Of note, the presence of intraclonal diversity in the B-LBL sample further suggests an earlier or concurrent event of MYC translocation than the somatic IGH mutation in the germinal center and the dedifferentiation of lymphoma cells to a precursor stage of B-cell development. CONCLUSIONS: B-lymphoblastic transformation of FL can occur with MYC gene rearrangement.

Involvement of the α-helical and Src homology 3 domains in the molecular assembly and enzymatic activity of human α1,6-fucosyltransferase, FUT8.

BACKGROUND: Previous structural analyses showed that human α1,6-fucosyltransferase, FUT8 contains a catalytic domain along with two additional domains, N-terminal α-helical domain and C-terminal Src homology 3 domain, but these domains are unique to FUT8 among glycosyltransferases. The role that these domains play in formation of the active form of FUT8 has not been investigated. This study reports on attempts to determine the involvement of these domains in the functions of FUT8. METHODS: Based on molecular modeling, the domain mutants were constructed by truncation and site-directed mutagenesis, and were heterologously expressed in Sf21 or COS-1 cells. The mutants were analyzed by SDS-PAGE and assayed for enzymatic activity. In vivo cross-linking experiments by introducing disulfide bonds were also carried out to examine the orientation of the domains in the molecular assembly. RESULTS: Mutagenesis and molecular modeling findings suggest that human FUT8 potentially forms homodimer in vivo via intermolecular hydrophobic interactions involving α-helical domains. Truncation or site-directed mutagenesis findings indicated that α-helical and SH3 domains are all required for enzymatic activity. In addition, in vivo cross-linking experiments clearly indicated that the SH3 domain located in close proximity to the α-helical domain in an intermolecular manner. CONCLUSIONS: α-Helical and SH3 domains are required for a fully active enzyme, and are also involved in homophilic dimerization, which probably results in the formation of the active form of human FUT8. GENERAL SIGNIFICANCE: α-Helical and SH3 domains, which are not commonly found in glycosyltransferases, play roles in the formation of the functional quaternary structure of human FUT8.

Characterization of MiFUT11 from Mangifera indica L.: A functional core α1,3-fucosyltransferase potentially involved in the biosynthesis of immunogenic carbohydrates in mango fruit.

In higher plants, asparagine-linked oligosaccharides (N-glycans) in glycoproteins carry unique carbohydrate epitopes, namely, a core α1,3-fucose and/or a ß1,2-xylose, which are common determinants responsible for the cross-reactivity of plant glycoproteins due to their strong immunogenicity. While these determinants and the relevant genes have been well characterized for herbaceous plants, information concerning whether many food plants cross-react with airborne pollens is not available. In this paper, we report on the characterization of a novel core α1,3-fucosyltransferase gene identified from Mangifera indica L., one of the major plants potentially related to food allergy. Based on sequence information of plant homologues, we amplified a candidate cDNA (MiFUT11) from pericarp tissue. An in vitro assay demonstrated that the recombinant MiFUT11 protein transfers a fucose unit onto both non-fucosylated and core α1,6-fucosylated oligosaccharides. A glycoform analysis using MALDI-TOF mass spectrometry showed that the introduction of the MiFUT11 cDNA increased the production of a core α1,3- and α1,6-fucosylated pauci-mannosidic oligosaccharide in Spodoptera Sf21 cells. Our findings suggest that MiFUT11 is a functional core α1,3-fucosyltransferase gene that is involved in the assembly of cross-reactive N-glycans in mango fruit.

Design and synthesis of functionalized coumarins as potential anti-austerity agents that eliminates cancer cells' tolerance to nutrition starvation.

Human pancreatic tumor cells have inherent ability to tolerate nutrition starvation which enables them to survive in the hypovascular tumor microenvironment. Discovery of agents that selectively inhibit the cancer cells' tolerance to nutrition starvation leading to cancer cell death is a new anti-austerity approach in anti-cancer drug discovery. A series of coumarins derivatives were synthesized and evaluated for their anti-austerity activity against PANC-1 human pancreatic cancer cell line. The compound 7-Hydroxy-2-oxo-2H-chromene-3-carboxylic acid (3-phenylpropyl)amide (2c) showed highly potent selective cytotoxicity against PANC-1 cells under nutrient-deprived conditions, with a PC50 value of 0.44 µM, without exhibiting toxicity in normal, nutrient-rich medium. Compound 2c caused dramatic alterations in PANC-1 cell morphology, leading to cell death. The compound 2c was found to inhibit PANC-1 cell migration and colony formation in a concentration-dependent manner. The compound 2c is a lead structure for the anti-austerity drug development against pancreatic cancer.

Essential structure of orexin 1 receptor antagonist YNT-707, part III: Role of the 14-hydroxy and the 3-methoxy groups in antagonistic activity toward the orexin 1 receptor in YNT-707 derivatives lacking the 4,5-epoxy ring.

Morphinan derivatives lacking the 4,5-epoxy ring were synthesized to examine the participation of the 14-OH group, the 3-OMe group, and the aromaticity of the A-ring in the activity and selectivity for the orexin 1 receptor (OX1R). The assay results and the conformational analyses of the 14-dehydrated and 14-H derivatives suggested that the orientations of the 6-amide side chain and the 17-benzenesulfonyl group would play important roles in the activity for OX1R. In the 6ß-derivatives, removal of the 3-OMe group and the reduction of the A-ring significantly decreased the activity toward the OX1R, but these changes did not affect the 6α-derivatives. These results indicate that the 3-OMe group and the A-ring would be essential structural moieties for the 6ß-derivatives.

[Cooperation between Clinics and Hospitals Using a Critical Path for G-CSF Prophylaxis in Cancer Chemotherapy].

BACKGROUND: Prophylactic granulocyte-colony stimulating factor(G-CSF)is necessary for some cancer patients receiving anti-cancer drugs. However, it is difficult for cancer patients in rural areas to receive G-CSF as outpatients because of inconvenient official transport, lack of public support, and low activity levels due to age. To resolve this problem, we began conducting a critical path(G-path)with regional medical institutions from 2011. METHODS: We retrospectively surveyed the clinical records of cancer patients receiving prophylactic G-CSF using G-path at our hospital. RESULTS: Eighty-two patients who were administered a total of 254 cycles of chemotherapy were examined between January 2011 and December 2016. Diseases included malignant lymphoma(n=64), pancreatic cancer(n=7), soft tissue sarcoma(n=5), and others(n=6). The median age of the patients was 70(range: 24-94)years. Fifty-three patients visited medical offices, and 31 patients visited regional hospitals. In 245 of 254(96%)cycles, planned G-CSF administration was performed. In 37 of 254(15%)cycles, infectious episodes developed, but patients needed hospitalization for only 5 cycles(2%). CONCLUSION: Cooperation between clinics and hospitals using G-path reduced ambulatory burden and prevented severe infection. Cooperation in supportive care may allow for equal accessibility to cancer treatment.

Cotylenin A and tyrosine kinase inhibitors synergistically inhibit the growth of chronic myeloid leukemia cells.

The treatment of chronic myeloid leukemia (CML) with tyrosine kinase inhibitors (TKIs) has substantially extended patient survival. However, TKIs do not effectively eliminate CML stem cells. In fact, CML stem cells persist and cause relapse in the majority of patients upon discontinuation of the drug treatment. Transcriptomic and proteomic analyses have revealed that p53 and c-Myc play defining roles in CML stem cell survival, suggesting that the dual targeting of p53 and c-Myc may selectively eliminate stem cells in patients with CML. Since the downregulation of c-Myc and then upregulation of p21 (a target gene of p53) are commonly observed during the differentiation of acute myeloid leukemia cells induced by differentiation inducers, we hypothesized that differentiation-inducing agents may be useful in regulating c-Myc and p53 expression in CML cells. In the present study, we demonstrate that some differentiation-inducing agents effectively suppress the self-renewal ability of CML cells, and that the combination of these inducers with TKIs results in significantly greater inhibitory effects on CML cell growth compared to the use of TKIs or the inducer alone. The KU812 cells were treated with various concentrations of the inducers in the presence or absence of 30 nM imatinib for 4 days. Among the differentiation inducers we tested, cotylenin A (CN-A) was the most potent at inhibiting the self-renewal ability of the CML cells. CN-A induced the robust expression of CD38, a marker of committed progenitor and more differentiated myelomonocytic cells, and rapidly suppressed c-Myc expression and upregulated p21 expression in CML cells. Thus, these results suggest that CN-A may have potential to promote the elimination of stem cells in CML.

A prospective study of palonosetron for prevention of chemotherapy-induced nausea and vomiting in malignant lymphoma patients following highly emetogenic chemotherapy.

BACKGROUND: Chemotherapy-induced nausea and vomiting (CINV) is a troublesome issue in chemotherapy for cancer patients. A second-generation 5HT3 receptor antagonist (5HT3RA), palonosetron, is effective and safe for the prevention of CINV in breast cancer patients treated with cyclophosphamide and anthracycline, but there is little data for malignant lymphoma. We conducted a prospective phase 2 study at a single institution to clarify the efficacy and safety of palonosetron in lymphoma patients. METHODS: Chemotherapy-naïve lymphoma patients who were treated with highly emetogenic chemotherapy (HEC) received a single intravenous bolus of palonosetron, 0.75 mg/body, before chemotherapy on day 1 during the first course of chemotherapy. The occurrence of CINV was assessed using the Multinational Association for Supportive Care in Cancer (MASCC) antiemesis tool, which was recorded by patients during the first course of chemotherapy. RESULTS: A total of 59 patients were enrolled, and 49 patients were eligible and evaluated. The complete response (CR) rate was 93.9% (95% confidence interval 83.1-98.7%) at 0-120 h post-chemotherapy. The proportion of patients who developed nausea of any grade and vomiting at 0-120 h post-chemotherapy was 34.7 and 6.1%, respectively. Although treatment-related adverse events were observed in 36 (73.5%) patients, these were mild and they recovered by the next cycle of chemotherapy. CONCLUSION: The present study demonstrated that a single dose of palonosetron was highly effective and safe for the prevention of CINV in lymphoma patients.

Molecular cloning and functional expression of Lewis type α1,3/α1,4-fucosyltransferase cDNAs from Mangifera indica L.

In higher plants, complex type N-glycans contain characteristic carbohydrate moieties that are not found in mammals. In particular, the attachment of the Lewis a (Lea) epitope is currently the only known outer chain elongation that is present in plant N-glycans. Such a modification is of great interest in terms of the biological function of complex type N-glycans in plant species. However, little is known regarding the exact molecular basis underlying their Lea expression. In the present study, we cloned two novel Lewis type fucosyltransferases (MiFUT13) from mango fruit, Mangifera indica L., heterologously expressed the proteins and structurally and functionally characterized them. Using an HPLC-based assay, we demonstrated that the recombinant MiFUT13 proteins mediate the α1,4-fucosylation of acceptor tetrasaccharides with a strict preference for type I-based structure to type II. The results and other findings suggest that MiFUT13s are involved in the biosynthesis of Lea containing glycoconjugates in mango fruits.

Essential structure of orexin 1 receptor antagonist YNT-707, Part I: Role of the 4,5-epoxy ring for binding with orexin 1 receptor.

The essential structure of the orexin 1 receptor (OX1R) antagonist YNT-707 (2) was clarified, particularly the roles to OX1R antagonist activities of the 3-OMe, the 4,5-epoxy ring, the 14-hydroxy group, and the orientation of the 6-amide side chain. The 3-OMe and 17-sulfonamide group were shown to be essential for the OX1R antagonistic activity. The 4,5-epoxy ring plays an important role for the active orientation of the 6-amide group. The 14-hydroxy group could lower the activity of the 6ß-amide isomer by the interaction of the 14-hydroxy group with the 6-amide group, which could orient the 6-amide group toward the upper side of the C-ring. Finally, we proposed the difference in the active conformation between OX1R and κ opioid receptor (KOR), especially in the orientation of the 6-amide group which is expected to be a useful guide for medicinal chemists to design OX1R ligands.

Design and Synthesis of Potent and Highly Selective Orexin 1 Receptor Antagonists with a Morphinan Skeleton and Their Pharmacologies.

Nalfurafine, a κ-selective opioid receptor agonist, unexpectedly showed a selective antagonist activity toward the orexin 1 receptor (OX1R) (Ki = 250 nM). Modification of the 17-amino side chain of the opioid ligand to an arylsulfonyl group and the 6-furan acrylamide chain to 2-pyridyl acrylamide led to compound 71 with improvement of the antagonist activity (OX1R, Ki = 1.36 nM; OX2R, not active) without any detectable affinity for the opioid receptor. The dihydrosulfate salt of 71, freely soluble in water, attenuated the physical dependence of morphine. Furthermore, all of the active nalfurafine derivatives in this study had almost no activity for OX2R, which led to high OX1R selectivity. These results suggest that nalfurafine derivatives could be a useful series of lead compounds to develop highly selective OX1R antagonists.

A retrospective study of R-CHOP/CHOP therapy-induced nausea and vomiting in non-Hodgkin's lymphoma patients: a comparison of intravenous and oral 5-HT3 receptor antagonists.

Chemotherapy-induced nausea and vomiting (CINV) is a serious problem for cancer patients receiving chemotherapy. The CHOP regimen is the standard treatment for non-Hodgkin's lymphoma (NHL) and is categorized as highly or moderately emetogenic in the CINV guidelines. The efficacy of oral 5-HT3 receptor antagonists is equivalent to that of the intravenous form in patients with solid tumors, but there is no clear comparative data for the use of these agents NHL patients receiving CHOP. We analyzed retrospective CINV data from medical records of 72 NHL patients who received CHOP or rituximab-combined CHOP therapy (R-CHOP). All patients received 5-HT3 receptor antagonists alone for prevention of CINV; 39 of the patients received an intravenous form (mostly granisetron) and 33 an oral form (all ramosetron). Complete response (CR: defined as no vomiting and no rescue therapy) was observed in 58 of 72 patients (80.6 %) overall (0-120 h post-CHOP). The CR rate was not statistically different in patients treated with oral or intravenous 5-HT3 receptor antagonists (82.1 vs 78.8 %, P = 0.77). These findings suggest that oral 5-HT3 receptor antagonists represent a good alternative to intravenous forms in NHL receiving CHOP/R-CHOP chemotherapy. Further studies are needed to identify the optimal anti-emetic supportive therapy for NHL.

A novel Na(+)(K(+))/H(+) antiporter plays an important role in the growth of Acetobacter tropicalis SKU1100 at high temperatures via regulation of cation and pH homeostasis.

A gene encoding a putative Na(+)/H(+) antiporter was previously proposed to be involved in the thermotolerance mechanism of Acetobacter tropicalis SKU 1100. The results of this study show that disruption of this antiporter gene impaired growth at high temperatures with an external pH>6.5. The growth impairment at high temperatures was much more severe in the absence of Na(+) (with only the presence of K(+)); under these conditions, cells failed to grow even at 30°C and neutral to alkaline pH values, suggesting that this protein is also important for K(+) tolerance. Functional analysis with inside-out membrane vesicles from wild type and mutant strains indicated that the antiporter, At-NhaK2 operates as an alkali cation/proton antiporter for ions such as Na(+), K(+), Li(+), and Rb(+) at acidic to neutral pH values (6.5-7.5). The membrane vesicles were also shown to contain a distinct pH-dependent Na(+)(specific)/H(+) antiporter(s) that might function at alkaline pH values. In addition, phylogenetic analysis showed that At-NhaK2 is a novel type of Na(+)/H(+) antiporter belonging to a phylogenetically distinct new clade. These data demonstrate that At-NhaK2 functions as a Na(+)(K(+))/H(+) antiporter and is essential for K(+) and pH homeostasis during the growth of A. tropicalis SKU1100, especially at higher temperatures.