Delayed administration of darbepoetin or erythropoietin protects against ischemic acute renal injury and failure

Administration of human recombinant erythropoietin (EPO) at time of acute ischemic renal injury (IRI) inhibits apoptosis, enhances tubular epithelial regeneration, and promotes renal functional recovery. The present study aimed to determine whether darbepoetin-alfa (DPO) exhibits comparable renoprotection to that afforded by EPO, whether pro or antiapoptotic Bcl-2 proteins are involved, and whether delayed administration of EPO or DPO 6 h following IRI ameliorates renal dysfunction. The model of IRI involved bilateral renal artery occlusion for 45 min in rats (N = 4 per group), followed by reperfusion for 1-7 days. Controls were sham-operated. Rats were treated at time of ischemia or sham operation (T0), or post-treated (6 h after the onset of reperfusion, T6) with EPO (5000 IU/kg), DPO (25 mug/kg), or appropriate vehicle by intraperitoneal injection. Renal function, structure, and immunohistochemistry for Bcl-2, Bcl-XL, and Bax were analyzed. DPO or EPO at T0 significantly abrogated renal dysfunction in IRI animals (serum creatinine for IRI 0.17 +/- 0.05 mmol/l vs DPO-IRI 0.08 +/- 0.03 mmol/l vs EPO-IRI 0.04 +/- 0.01 mmol/l, P = 0.01). Delayed administration of DPO or EPO (T6) also significantly abrogated subsequent renal dysfunction (serum creatinine for IRI 0.17 +/- 0.05 mmol/l vs DPO-IRI 0.06 +/- 0.01 mmol/l vs EPO-IRI 0.03 +/- 0.03 mmol/l, P = 0.01). There was also significantly decreased tissue injury (apoptosis, P < 0.05), decreased proapoptotic Bax, and increased regenerative capacity, especially in the outer stripe of the outer medulla, with DPO or EPO at T0 or T6. These results reaffirm the potential clinical application of DPO and EPO as novel renoprotective agents for patients at risk of ischemic acute renal failure or after having sustained an ischemic renal insult.

A phase II study of R-CHOP in treatment of diffuse large B-cell lymphoma (DLBCL) subgroups

17540

Background: Recent studies with genes expression profiling and tissue microarray have divided the diffuse large B cell lymphoma (DLBCL) into prognostically important subgroups with germinal center B cell like (GCB) and non-GCB. However, these results are based on the samples of patients who were received standard CHOP regimen. Combination with CHOP and Rituximab (R-CHOP) has been proved to improve the survival of patients with DLBCL. To evaluate the efficacy of R-CHOP in different subgroups of DLBCL, this phase II study has been conducted. Methods: Previously untreated patients with DLBCL were enrolled in this study. No upper age limit was specified. Patients received six cycles of R-CHOP (rituximab 375 mg/m2, cyclophosphamide 750 mg/m2, doxorubicin 50 mg/m2, vincristine 1.4 mg/m2, and prednisone 40 mg/m2 for 5 days) every 3 weeks. Immunohistochemical stains on paraffin-embedded tissues from diagnostic biopsies from these patients with antibodies against GCB cell (CD10 and Bcl-6) and activation (MUM1). These patients are divided into GCB and non-GCB groups according to the expression of antibodies against CD10, BCL-6 and MUM1. Results: A total of 64 patients were evaluated, 19 in GCB group and 45 in non-GCB group. Complete Remission (CR) rate was achieved 57.9% and 53.3%, in GCB group and in non-GCB group, respectively. (p = 0.737). A median follow-up of 2.2 years, the two-year failure free survival was no different between two groups (p = 0.566). Conclusions: In patients with GCB group or non-GCB group of DLBCL, addition of Rituximab in CHOP regimen, preliminary result was showed in similar response and survival.

No significant financial relationships to disclose.

Oxaliplatin/CF/5-FU versus paclitaxel/CF/5-FU in patients with advanced gastric cancer: A phase II clinical trial

14014

Background: Although many randomized trials of chemotherapy for advanced gastric cancer have been reported during the past two decades, no standard regimens worldwide have been established yet. Now Paclitaxel and Oxaliplatin have shown promising activity in advanced gastric cancer. We prospectively evaluated toxicity, efficacy and survival of Oxaliplatin /CF/5-FU versus Paclitaxel/CF/5-FU. Methods: Metastatic or locally advanced gastric cancer; performance status (PS) 0–2. Patients (pts) were enrolled and randomized into arm A with Oxaliplatin 100mg/m2, 5-FU 400 mg/m2 bolus, FA 200 mg/m2 2h, 5-FU 2500 mg/m2 46h, q2w or into arm B with Paclitaxel 80 mg/m2, 5-FU 400 mg/m2 bolus, FA 200 mg/m2 2h, 5-FU 2500 mg/m2 46h, q2w. Results: From 2000 to 2005, (A/B) 46/43 pts were enrolled into this study. Median age (52/50 y), gender, PS, localization and numbers of metastatic sites were comparable for both arms. Pts who were not chemotherapy naive in A/B (% of pts) were 41.3/33.3. All pts were eligible and evaluable for toxicity and response. Overall response (CR+PR) rate for A/B (% of pts): 37.0/47.2 (p<0.05), tumor control rate (CR+PR+SD) 76.1/69.4(p<0.05). Median time to progression (TTP) were for A/B: 6.0 and 3.2 months. And median survival time for A/B were 13.4 and 13.8 months. Grade 3/4 toxicities were for A/B (% of pts): neutropenia 10.9/5.6, thrombocytopenia 4.3/2.8, anemia 0/2.8, vomiting 8.7/2.8, neurotoxic 0/2. No treatment-related death occurred in A/B. Conclusions: Oxaliplatin /CF/5-FU and Paclitaxel/CF/5-FU are both effective and safe in advanced or metastatic gastric cancer. Though Oxaliplatin /CF/5-FU had better tumor control rate and median TTP, there was no difference between the arms in the median survival time.

No significant financial relationships to disclose.

Prognostic value of hemoglobin in natural killer cell lymphoma

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Background: Natural Killer (NK) cell lymphoma is a group of increasingly recognized but poorly defined disease entities. This study investigated its clinical features and prognostic factors for southern China population. Methods: Patients with pathologically confirmed NK cell lymphoma in one center since 1999 to 2004 were included. Central histological and immunohistochemical review was undertaken to every case. The major study endpoint was overall survival. Survival curves were estimated by the Kaplan-Meier method. Detailed clinical, pathological and laboratory data were included in univariate analysis and statistically significant factors in univariate analysis were then included in multivariate analysis. Results: Totally 64 eligible patients were identified. Of these, 59 patients were extranodal NK cell lymphoma nasal type, 3 patients were aggressive NK cell lymphoma and 2 patients were blastic NK cell lymphoma. From the basic analysis, 47% of the patients had stage I disease, 42% were stage II, 11% were stage III or IV. B-symptoms were present in 39%. 73% of these patients had International Prognostic Index (IPI) 0 or 1. Before treatment, 25% complicated with anemia. As to the therapy, 38% received chemotherapy alone, 3% received radiotherapy alone and 59% received a multidisciplinary therapy. After initial therapy, 59% achieved CR, 22% achieved PR and 19% were refractory disease. With a median follow-up duration of 20 months, the median overall survival was 28 months (95% CI: 10, 45). Hb lower than 110 g/l before treatment was statistically significant in multivariate analysis (p = 0.031). Presenting B-symptoms and ECOG PS score higher than 1 were also independent prognostic factors (P = 0.001 and 0.006 respectively). Conclusions: The outcome of patients with NK cell lymphoma was poor even for Stage I or II cases. Our data suggested Hemoglobin < 110 g/l had more prognostic value than IPI and Ann Arbor staging system for NK cell lymphoma in southern China, but it needs further confirmation.

No significant financial relationships to disclose.

Acetylcholinesterase expression mediated by c-Jun-NH2-terminal kinase pathway during anticancer drug-induced apoptosis

It has been shown that acetylcholinesterase (AChE) expression was induced during apoptosis and the anti-sense oligonucleotides and siRNA of AChE may prevent apoptosis in various cell types. However, the mechanisms underlying AChE upregulation remain elusive. We demonstrated here that c-Jun NH2-terminal kinase (JNK) could mediate AChE expression. In this study, both etoposide and excisanin A, two anticancer agents, induced apoptosis in colon cancer cell line SW620 as determined by Annexin V staining, the cleavage of caspase-3 and the proteolytic degradation of poly (ADP-ribose) polymerase (PARP). The results showed that both the agents upregulated AChE in SW620 cells. In the meantime, JNK was also activated and the expression and phosphorylation of c-Jun increased in SW620 cells exposed to the two agents. The induced AChE mRNA and protein expression could be blocked by SP600125, a specific inhibitor of SAPK/JNK, and small interfering RNA directed against JNK1/2. Transfection with adenovirus-mediated dominant negative c-Jun also blocked the upregulation of AChE expression. Together, these results suggest that AChE expression may be mediated by the activation of JNK pathway during apoptosis through a c-Jun-dependent mechanism.

Sustained augmentation of cardiac alpha1A-adrenergic drive results in pathological remodeling with contractile dysfunction, progressive fibrosis and reactivation of matricellular protein genes

We previously reported that transgenic (TG) mice with cardiac-restricted alpha(1A)-adrenergic receptor (alpha(1A)-AR)-overexpression showed enhanced contractility, but no hypertrophy. Since chronic inotropic enhancement may be deleterious, we investigated if long-term, cardiac function and longevity are compromised. alpha(1A)-TG mice, but not their non-TG littermates (NTLs), showed progressive loss of left ventricular (LV) hypercontractility (dP/dt(max): 14,567+/-603 to 11,610+/-915 mmHg/s, P<0.05, A1A1 line: 170-fold overexpression; and 13,625+/-826 to 8322+/-682 mmHg/s, respectively, P<0.05, A1A4 line: 112-fold overexpression, at 2 and 6 months, respectively). Both TG lines developed LV fibrosis, but not LV dilatation or hypertrophy, despite activation of hypertrophic signaling pathways. Microarray and real time RT-PCR analyses revealed activation of matricellular protein genes, including those for thrombospondin 1, connective tissue growth factor and tenascin C, but not transforming growth factor beta1. Life-span was markedly shortened (mean age at death: 155 days, A1A1 line; 224 days, A1A4 line compared with NTLs: >300 days). Telemetric electrocardiography revealed that death in the alpha(1A)-AR TG mice was due to cardiac standstill preceded by a progressive diminution in QRS amplitude, but not by arrhythmias. The QRS changes and sudden death could be mimicked by alpha(1)-AR activation, and reversed preterminally by alpha(1)-AR blockade, suggesting a relationship to stress- or activity-associated catecholamine release. Thus, long-term augmentation of cardiac alpha(1A)-adrenergic drive leads to premature death and progressive LV fibrosis with reactivation of matricellular protein genes. To our knowledge this is the first evidence in vivo for a role of the alpha(1A)-AR in ventricular fibrosis and in pathological cardiac remodeling.

Prospective randomised phase II study of gemcitabine at standard or fixed dose rate schedule in unresectable hepatocellular carcinoma

The present randomised phase II study was an effort to evaluate single-agent gemcitabine as a first-line systemic treatment of Asian patients with unresectable hepatocellular carcinoma (HCC). Gemcitabine was given via intravenous infusion at 1250 mg m(-2) on days 1 and 8 of 3-week cycles. Patients were randomised to receive gemcitabine as a 30-min intravenous infusion (standard schedule) or at a fixed dose rate (FDR) of 10 mg m(-2) min(-1). A total of 50 patients were enrolled in the study, of whom 48 received study therapy. One patient on standard schedule had a partial response, for an overall response rate of 2.1% (95% CI: 0.05-11.1%). The median time to progression and survival time were 46 and 97 days, respectively. The overall rates of Grade 3 or 4 haematological and nonhaematological toxicities were 39.6 and 64.6%, respectively, with no significant difference between the two treatment arms. There were no drug-related deaths and severe clinical toxicities were rare. Both schedules of gemcitabine were safe and toxicity was well manageable in this patient population. However, gemcitabine seems no more active than other cytotoxic agents when used alone for systemic treatment of advanced HCC.

Facilitation of renal autoregulation by angiotensin II is mediated through modulation of nitric oxide

AIMS

This study was designed to investigate the influence of angiotensin II (Ang II) and nitric oxide (NO) on autoregulation of renal perfusion.

METHODS

Autoregulation was investigated in isolated perfused kidneys (IPRK) from Sprague-Dawley rats during stepped increases in perfusion pressure.

RESULTS

Ang II (75-200 pM) produced dose-dependent enhancement of autoregulation whereas phenylephrine produced no enhancement and impaired autoregulation of GFR. Enhancement by Ang II was inhibited by the AT1 antagonist, Losartan, and the superoxide scavenger, Tempol. Under control conditions nitric oxide synthase (NOS) inhibition by 10 microm N-omega-nitro-L-arginine methyl ester (L-NAME) facilitated autoregulation in the presence of non-specific cyclooxygenase (COX) inhibition by 10 microm indomethacin. Both COX and combined NOS/COX inhibition reduced the autoregulatory threshold concentration of Ang II. Facilitation by 100 pm Ang II was inhibited by 100 microm frusemide. Methacholine (50 nm) antagonised Ang II-facilitated autoregulation in the presence and absence of NOS/COX inhibition. Infusion of the NO donor, 1 microm sodium nitroprusside, inhibited L-NAME enhancement of autoregulation under control conditions and during Ang II infusion.

CONCLUSIONS

The results suggest than an excess of NO impairs autoregulation under control conditions in the IPRK and that endogenous and exogenous NO, vasodilatory prostaglandins and endothelium-derived hyperpolarizing factor (EDHF) activity antagonise Ang II-facilitated autoregulation. Ang II also produced a counterregulatory vasodilatory response that included prostaglandin and NO release. We suggest that Ang II facilitates autoregulation by a tubuloglomerular feedback-dependent mechanism through AT1 receptor-mediated depletion of nitric oxide, probably by stimulating generation of superoxide.

Human ZIP1 is a major zinc uptake transporter for the accumulation of zinc in prostate cells

The prostate gland of humans and other animals accumulates a level of zinc that is 3-10 times greater than that found in other tissues. Associated with this ability to accumulate zinc is a rapid zinc uptake process in human prostate cells, which we previously identified as the hZIP1 zinc transporter. We now provide additional evidence that hZIP1 is an important operational transporter that allows for the transport and accumulation of zinc. The studies reveal that hZIP1 (SLC39A1) but not hZIP2 (SLC39A2) is expressed in the zinc-accumulating human prostate cell lines, LNCaP and PC-3. Transfected PC-3 cells that overexpress hZIP1 exhibit increased uptake and accumulation of zinc. The V(max) for zinc uptake was increased with no change in K(m). Along with the increased intracellular accumulation of zinc, the overexpression of hZIP1 also results in the inhibition of growth of PC-3 cells. Down-regulation of hZIP1 by treatment of PC-3 cells with hZIP1 antisense oligonucleotide resulted in a decreased zinc uptake. Uptake of zinc from zinc chelated with citrate was as rapid as from free zinc ions; however, the cells did not take up zinc chelated with EDTA. The cellular uptake of zinc is not dependent upon an available pool of free Zn(2+) ions. Instead, the mechanism of transport appears to involve the transport of zinc from low molecular weight ligands that exist in circulation as relatively loosely bound complexes with zinc.

A multicenter phase II study of the efficacy and safety of docetaxel plus cisplatin in Asian chemonaïve patients with metastatic or locally advanced non-small cell lung cancer

AIMS

To evaluate the efficacy and safety of docetaxel-cisplatin in patients with metastatic or locally advanced non-small cell lung cancer (NSCLC).

METHODS

Chemotherapy-naïve patients with histologically confirmed TNM stage III or IV NSCLC were recruited from 12 Asian trial centers. Patients received docetaxel (75 mg/m2) and cisplatin (75 mg/m2) every 3 weeks for 6 cycles.

RESULTS

130 of 146 patients were evaluable for efficacy (60% stage IV). Three complete and 58 partial responses were observed (overall response rate: 46.9%; 95% CI: 38.3-55.5%). Median time to progression was 6.9 months and median survival was 14.0 months; 1-year survival was 59.5%. Grade 3/4 neutropenia, thrombocytopenia and anemia occurred in 69.2%, 6.2% and 18.5% of patients, respectively. Grade 3/4 vomiting was observed in 13.7% and grade 3/4 neurosensory effects were observed in 2.7% of patients. There was one case of treatment-related death due to sepsis.

CONCLUSION

Docetaxel-cisplatin is an effective and well-tolerated treatment in Asian patients with NSCLC.

Isolation and insecticidal activity of mellamide from Aspergillus melleus

Mellamide, a novel indole amide, was isolated from a fermentation of Aspergillus melleus using silica gel and high-performance liquid chromatographic methods. This allowed its separation from three known antiparasitic compounds (ochratoxin A, viomellin and xanthomegnin) also present in the potent extract. The structure was elucidated by (1)H, (13)C, COSY, DEPT, HMQC and HMBC NMR experiments. HR-FTMS aided in the molecular weight and formula determination. Mellamide showed in vitro insecticidal activity in bioassays against larvae of Lucilia sericata and Aedes egypti with LD(90) of 1,000 and 50 micro g/ml, respectively.

The neuropathological and behavioral consequences of intraspinal microglial/macrophage activation

Activated microglia and macrophages (CNS macrophages) have been implicated in the secondary or "bystander" pathology (e.g. axon injury, demyelination) that accompanies traumatic or autoimmune injury to the brain and spinal cord. These cells also can provide neurotrophic support and promote axonal regeneration. Studying the divergent functional potential of CNS macrophages in trauma models is especially difficult due to the various degradative mechanisms that are initiated prior to or concomitant with microglial/macrophage activation (e.g. hemorrhage, edema, excitotoxicity, lipid peroxidation). To study the potential impact of activated CNS macrophages on the spinal cord parenchyma, we have characterized an in vivo model of non-traumatic spinal cord neuroinflammation. Specifically, focal activation of CNS macrophages was achieved using stereotaxic microinjections of zymosan. Although microinjection does not cause direct mechanical trauma, localized activation of macrophages with zymosan acts as an "inflammatory scalpel" causing tissue injury at and nearby the injection site. The present data reveal that activation of CNS macrophages in vivo can result in permanent axonal injury and demyelination. Moreover, the pathology can be graded and localized to specific white matter tracts to produce quantifiable behavioral deficits. Further development of this model will help to clarify the biological potential of microglia and macrophages and the molecular signals that control their function within the spinal cord.

Bacillus subtilis arsenate reductase is structurally and functionally similar to low molecular weight protein tyrosine phosphatases

Arsenate is an abundant oxyanion that, because of its ability to mimic the phosphate group, is toxic to cells. Arsenate reductase (EC; encoded by the arsC gene in bacteria) participates to achieve arsenate resistance in both prokaryotes and yeast by reducing arsenate to arsenite; the arsenite is then exported by a specific transporter. The crystal structure of Bacillus subtilis arsenate reductase in the reduced form with a bound sulfate ion in its active site is solved at 1.6-A resolution. Significant structural similarity is seen between arsenate reductase and bovine low molecular weight protein tyrosine phosphatase, despite very low sequence identity. The similarity is especially high between their active sites. It is further confirmed that this structural homology is relevant functionally by showing the phosphatase activity of the arsenate reductase in vitro. Thus, we can understand the arsenate reduction in the light of low molecular weight protein tyrosine phosphatase mechanism and also explain the catalytic roles of essential residues such as Cys-10, Cys-82, Cys-89, Arg-16, and Asp-105. A "triple cysteine redox relay" is proposed for the arsenate reduction mechanism.

Preparation and crystallization of a Bacillus subtilis arsenate reductase

Arsenate reductase (AR) in B. subtilis is encoded by the chromosomal arsC gene. Together with arsB and arsR, arsC participates in detoxification processes for the arsenate and arsenite ions. Full-length arsenate reductase without any modification has been expressed in Escherichia coli and purified in a soluble form. The recombinant protein has been crystallized at 277 K using polyethyleneglycol (PEG) or poly(ethyleneglycol) methyl ether (PME) as the main precipitant. At least two forms of crystals large enough for data collection have been obtained from wild-type protein under different conditions. An orthorhombic crystal diffracted to beyond 2.2 A with space group P2(1)2(1)2(1) and unit-cell parameters a = 51.22, b = 91.62, c = 101.93 A. A near-complete data set has been collected to 2.5 A. The application of the flash-annealing technique was crucial for high resolution during the data collection. The SeMet-substituted AR has also been produced and crystallized under very similar conditions as the wild type, but the unit-cell parameters are very different. The crystals of the SeMet protein diffracted to higher resolution than those of the wild type.

Separation and quantitation of phospholipids and their ether analogues by high-performance liquid chromatography

The common mobile phase hexane/isopropanol/water used for separation of phospholipids on high-performance liquid chromatography silica columns poses several problems, such as incomplete separation and rapid column deterioration. By inclusion of 5 mM ammonium sulfate in the aqueous phase, we were able to substantially improve the chromatographic resolution and obtain complete separation of phosphatidylcholine, phosphatidylethanolamine, lysophosphatidylcholine, lysophosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, cardiolipin, phosphatidylglycerol, and sphingomyelin. In addition, ammonium sulfate prevented column degeneration and greatly improved reproducibility. A new quantitation method for alkenylacyl, alkylacyl, and diacyl forms of phospholipids was also developed based on derivatization with [(3)H]acetic anhydride. Separation and quantitation of the radioactive acetyl diradylglycerols were performed by straight-phase HPLC coupled to a radioactive flow detector and enabled detection of the various ether analogues at the picomole level with high reproducibility. The described methods are mild and nondestructive and can therefore be easily combined with analysis of either molecular species or fatty acid and aldehyde composition of the individual phospholipids.

Speciation of rare earth elements in soil by sequential extraction then HPLC coupled with visible and ICP-MS detection

The distribution of rare earth elements (REE) in a pooled soil sample collected from Zhangzhou, Fujian Province, China, was screened by a five-step sequential extraction procedure coupled with ICP-MS determination after preconcentration of REE and removal of the matrix by extraction with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (HPMBP). The results showed that the distribution of REE in the different fractions of the pooled soil sample studied followed the order soluble species (46.76%) > species bound to organic matter (22.08%) > species in the residue (16.77%) > species bound to Fe-Mn oxides (2.02%). An effective method for speciation of REE, which utilized weak cation-exchange HPLC separation hyphenated with post-column derivatization and visible or on line ICP-MS detection, was, moreover, developed and successfully applied to the speciation of REE in the soluble extract of the pooled soil sample. The stability of known complexes of lanthanum during the HPLC separation was investigated with fluoride, citrate, and ethylenediamine tetraacetic acid (EDTA) chosen as ligands modeling those in the soil. REE in the soluble extract of the pooled soil sample were subsequently classified into three types of species--< or = +1 charged complexes (negatively charged, neutral, and +1 charged), +2 charged complexes, and "free" REE species. This method is expected to be useful for identification of bioavailable (or toxic) species of REE in environmental samples.