Investigation of the binding behaviors of isonucleoside-incorporated oligonucleotides with complementary sequences

Oligonucleotides consisting of isonucleoside 2',5'-anhydro-3'-nucleobase-D-mannitol incorporated in 1'→4' linkage mode were synthesized. Their binding behaviors with complementary sequences were investigated via thermal denaturation and CD spectra. 6' O-methyl-2',5'-anhydro-3'-(thymin-1-yl)-D-mannitol incorporated oligonucleotide was also synthesized to investigate the effect of hydroxy groups of isonucleosides on duplex formation. The results showed that the 6'-OH free isonucleosidemodified oligonucleotide was able to form a B-like duplex with 3'→5' complementary native oligodeoxynucleotide in the 1'→4' direction. The free hydroxy group in the isonucleoside made a significant contribution to the affinity of the modified oligonucleotide to the complementary sequence, which was confirmed by molecular dynamics simulation.

Nadaplatin or cisplatin combined with paclitaxol in treating non-small cell lung cancer: A randomized controlled study

7689

Background: Nadaplatin is a 2nd generation platinum compound created in Japan. It also has been used in China for recent years and shown treatment effect in several kinds of cancer including lung cancer. However, no randomized clinical trial has been done compared with cisplatin when combined with paclitaxol in treating non-small cell lung cancer. This prospective clinical study is to investigate the treatment effect, long term survival, side effect and quality of life (QOL) of NSCLC patients treated with nadaplatin combined with paclitaxol controlled with cisplatin combined with paclitaxol. Methods: NSCLC patients with stage IIIB or IV were randomized into two groups: TN group- nadaplatin 30 mg/m2 d1–3, paclitaxol 175 mg/m2 d1, repeated every 4 weeks; TP group- DDP30 mg/m2 d1–3, paclitaxol 175 mg/m2 d1, repeated every 4 weeks. The treatment effect, 1 and 2 year survival and the side effect were observed. The functional assessment of cancer therapy-lung (FACT-L) was used to evaluate the quality of life (QOL). Results: Sixty patients were enrolled and 57 were assessable with 30 in TN group and 27 in TP group. The overall response rate were 43.3% vs 48.1% (P=0.716), and the disease control rate were 86.7% vs 88.8% in TN and TP group (P=0.799), respectively. The median survival time were 14.3 vs 13.0 months, and the 1 and 2 year survival were 62.5% vs 59.1%, 0% vs 5.8% in TN and TP group (P=0.839), respectively. Neutropenia and thrombocytopenia were similar in TN and TP group whereas more patients in TP group suffered from anemia (38.5% vs 17.5%, P=0.001), nausea and vomiting (68.0% vs 34.7% with grade 1 and 2, 14.6% vs 0.9% with grade 3 and 4, P=0.000), fatigue (35.9% vs 14.1% P=0.000) and peripheral neurotoxicity (50.0% vs 21.9%, calculated by case, p=0.023). In the FACT-L assessment, the relationship with doctor, the emotional well-being and the lung cancer related symptom were similarly improved in both TN and TP group whereas physical well-being was improved only in TN group. Conclusions: Nadaplatin combined with paclitaxol is an effective treatment regimen for NSCLC patients. When compared with similar regimen using cisplatin, the response rate and survival were similar; however, nadaplatin regimen shows superiority in some aspects of side effects and QOL.

No significant financial relationships to disclose.

Clinical significance of Epstein-Barr Virus DNA load detected pre- and post-radiotherapy in nasopharyngeal carcinoma patients

10558

Background: Plasma Epstein-Barr virus DNA (EBV DNA) load has been shown to be clinically useful in the detection, monitoring, and prognostication of nasopharyngeal carcinoma (NPC). However, the clinical significance of EBV DNA load detected at different time points has not been addressed to our knowledge. In this study, we investigated whether pre- and post-treatment plasma EBV DNA load have different prognostic implications in NPC patients who were treated with radiotherapy. Methods: Plasma samples from 69 patients with primary NPC were collected before and after radiation treatment, and subjected to a real-time quantitative polymerase-chain- reaction assay of EBV DNA load. The pre-treatment primary tumor volume (GTVnx) calculated through CT images and/or MRI were documented. All patients were scheduled to follow up. Results: The pre-treatment plasma EBV DNA concentration was significantly associated with primary tumor volume (Spearman correlation coefficient=0.614; P=0.000). With a cutoff value of 20,000 copies/ml and 0 copies/ml respectively for pre-treatment and post-treatment plasma EBV DNA copy number, patients with lower EBV DNA concentrations had statistically preferable progression-free survival,metastasis-free survival and overall survival compared with those with higher EBV DNA concentrations. Cox regression analysis demonstrated that both pre-treatment EBV DNA load (P=0.050;RR=3.95) and post-treatment EBV DNA load (P=0.001;RR=11.74) were risk factors for metastasis-free survival. When further integrating pre-treatment with post-treatment concentration of EBV DNA, it was demonstrated that whether EBV DNA concentration could be dropped to 0 after treatment dominate the prognostic effect for metastasis-free survival (P=0.000). Conclusions: Pre- and post-treatment plasma EBV DNA have different clinical significance. Pre-treatment plasma EBV DNA is a reliable molecular marker reflecting primary tumor volume. While the clearance of circulating plasma EBV DNA after treatment is a good predictive marker of freedom from distant metastasis.

No significant financial relationships to disclose.

Randomized controlled comparative clinical pharmacokinetic study of nab-paclitaxel and solvent-based paclitaxel in Chinese patients (pts) with metastatic breast cancer (MBC)

11505

Background: nab-paclitaxel is a novel solvent-free, 130-nM albumin-bound (nab™) formulation of paclitaxel. In previous studies, nab-paclitaxel demonstrated higher volume of distribution and clearance than that of paclitaxel formulated with Cremophor (Cr-PAC) in Caucasian patients (Sparreboom, Clin Cancer Res 2005;11:4136) and had greater response rate and favorable safety profile in pts with MBC (Gradishar et al., JCO, 2005;23:7794) . The aim of this study was to evaluate nab-paclitaxel blood pharmacokinetics (PK) and compare it with that of Cr-PAC in Chinese MBC patients.Methods: In this randomized controlled, open-label study, patients were assigned to either nab-paclitaxel 260 mg/m2 intravenously (iv) over 30 minutes q3w or Cr-PAC 175 mg/m2 iv over 3 hours q3w. At cycle 1, 12 patients in each treatment group participated in the PK study and then continued treatment until PD or unacceptable toxicity. Plasma samples from pts were analyzed for PK parameters. The primary clinical endpoints were ORR and toxicity (Guan et al; submitted, ASCO, 2007). Results: 24 female pts (median age 44.5 years) participated. No statistically significant between group differences were noted in age, height, weight, or baseline liver function. Paclitaxel blood PK parameters in 2 treatment groups are summarized in the Table. ORR: nab-paclitaxel, 75%; Cr-PAC, 25% (P = 0.018). The maximum grade (G) of neutropenia and neuropathy in the nab-paclitaxel and Cr-PAC groups were G3 and G2, respectively, with no significant between-group difference. Conclusion: nab-Paclitaxel had a greater distribution volume, clearance, and smaller dose adjusted AUC0-inf compared with that of Cr-PAC. There was no significant difference in T1/2 in the 2 groups. PK results in Chinese pts are identical to data reported in Caucasian pts. The lower CL and Vz for Cr-PAC are probably related to sequestration of paclitaxel in the blood by Cremophor. * dose adjusted AUC0-inf

[Table: see text]

[Table: see text]

Randomized study comparing nab-paclitaxel with solvent-based paclitaxel in Chinese patients (pts) with metastatic breast cancer (MBC)

1038

Background: The results of a large clinical study comparing solvent-based paclitaxel 175 mg/m2 with 130-nM albumin-bound paclitaxel (nab-paclitaxel) 260 mg/m2 demonstrated that nab-paclitaxel had greater efficacy and a favorable safety profile in pts with MBC (Gradishar et al., JCO, 2005; 23:7794). The maximum tolerated dose of nab-paclitaxel was 300 mg/m2 infused over 30 minutes without premedication in Chinese pts with solid tumors (Teng et al., Ai Zheng, 2004;23:1431). The aim of this randomized study is to compare the response rates and to evaluate the safety of nab-paclitaxel with those of solvent-based paclitaxel in Chinese pts with MBC. Methods: In this open-label, multicenter study, 210 pts with MBC were assigned to either solvent-based paclitaxel 175 mg/m2 intravenously (IV) over 3 hours every 3 weeks (q3w) with standard premedication (steroids and antihistamines) or nab-paclitaxel 260 mg/m2 IV over 30 minutes q3w with no premedication for 1–6 cycles. The primary endpoints were the overall response rate (ORR, complete or partial response) and toxicity. Stable disease (SD) at =16 weeks was measured. All pts who received at least 1 dose of study drug were evaluable for study endpoints. Results: 210 pts (median age, 50 years; 70% postmenopausal) were enrolled from 29 June 2005 - 1 August 2006. Efficacy results are summarized in the Table . The common toxicities occurring at =20% were alopecia (78%), peripheral neuropathy (75%, 7% gr 3), neutropenia (65%), leucopenia (60%), myalgia (39%), arthralgia (23%), and nausea (21%) and were similar between groups (P = NS). Gr 3/4 neutropenia, measured on days 1 and 8, were similar between groups (p = 0.202). Conclusions: Compared to solvent- based paclitaxel, treatment with nab-paclitaxel was associated with a higher response rate and longer time to progression without increased toxicity. These comparative data in Chinese pts are almost identical to results previously reported in Caucasian pts (Gradishar et al, JCO, 2005).

[Table: see text]

[Table: see text]

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

17557

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.

Pegylated brain-derived neurotrophic factor shows improved distribution into the spinal cord and stimulates locomotor activity and morphological changes after injury

The neurotrophin brain-derived neurotrophic factor (BDNF) shows promise for the treatment of central nervous system (CNS) trauma and disease. Effective delivery methods are required, however, for BDNF to be useful as a therapeutic agent. To this end, we examined the penetration of intrathecally infused N-terminal pegylated BDNF (peg-BDNF) compared to similar infusion of native BDNF after spinal cord injury (SCI). Pegylation dramatically improved delivery of BDNF to the spinal cord and induced the expression of Fos in spinal cord neurons. To test whether enhanced delivery would improve the modest effects on behavioral recovery and axonal outgrowth observed with native BDNF infusion, we assessed the efficacy of 2-week 25 microg/day peg-BDNF treatment, beginning 12-24 h (early) or 15 days (delayed) after midthoracic spinal contusion. Similar to native BDNF, early treatment with peg-BDNF accelerated the recovery of stepping in the open-field and acutely stimulated locomotor central pattern generator activity, as seen by the activation of hindlimb airstepping during either period of administration. The infusion of peg-BDNF, regardless of the timing of delivery, was related to enhanced sprouting of putative cholinergic fibers, like that observed after high dose native BDNF treatment. Despite improved delivery, however, neither axonal responses nor the extent of locomotor recovery were enhanced compared to native BDNF treatment. This suggests that alternative strategies, such as neurotrophin treatment in conjunction with cell transplantation techniques, or treatment nearer the cell bodies of target neurons might be employed in an attempt to effect significant repair after SCI.

Sleep modifies glutamate decarboxylase mRNA within the barrel cortex of rats after a mystacial whisker trim

STUDY OBJECTIVES

Determine the effects of time of day and sleep deprivation on glutamate decarboxylase 67,000 MW (GAD67) mRNA during cortical synaptic reorganization induced by a unilateral trimming of the mystacial vibrissae in rats.

DESIGN

Two experiments were conducted--One measured GAD67 mRNA in the barrel cortex at 3 or 6 h after a unilateral whisker cut at either light or dark onset; the other measured GAD67 mRNA after a unilateral whisker cut at light onset with or without sleep deprivation.

SETTING

University-based Research Laboratory.

PARTICIPANTS

Sprague-Dawley rats (250-350 g).

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

The reverse transcriptase polymerase chain reaction was used to measure the time of day changes in GAD67 mRNA after a unilateral whisker cut. GAD67 mRNA decreased in the barrel cortex at 3 and 6 h after a whisker trim at dark onset when the rats were mainly awake. No changes were observed in GAD67 mRNA levels after a whisker cut at light onset, a time when the rats mainly sleep. In situ hybridization for GAD67 mRNA supported these findings; no changes in GAD mRNA occurred in layer 4 of the barrel cortex that received input from the mystacial whiskers that were trimmed at light onset. However, when the rats were sleep-deprived, GAD67 mRNA increased in the barrel cortex receiving input from the lip hairs surrounding the trimmed mystacial whiskers.

CONCLUSIONS

These data imply that sleep modifies GAD67 mRNA expression and that this effect is dependent upon the nature of the ongoing synaptic reorganization. They support the notion that sleep serves a synaptic function.

Sleep deprivation but not a whisker trim increases nerve growth factor within barrel cortical neurons

Sleep is hypothesized to influence activity-driven changes in the brain microcircuitry. A change in the barrel cortex following the removal of the mystacial whiskers in rats is a model for synaptic plasticity. This model was combined with sleep deprivation and immunoreactivity for nerve growth factor (NGF) was determined. Sleep deprivation for 6 h after light onset significantly increased the number of NGF-immunoreactive pyramidal neurons in layer V of the barrel cortex. However, unilateral trimming of mystacial whiskers did not affect NGF immunoreactivity in the contralateral or ipsilateral barrel cortices when rats were allowed to sleep. If the rats received a unilateral whisker cut at light onset, and subsequently were deprived of sleep, increases in the NGF-immunoreactive neurons were only observed in the barrel cortex on the side that received input from the remaining intact whiskers. In contrast, NGF immunoreactivity on the side contralateral to the cut whiskers decreased in sleep-deprived animals to levels below those observed in the control animals that were allowed to sleep. These results suggest that NGF expression is influenced by the interaction of sleep, afferent input and the nature of ongoing synaptic reorganization. Further, results are consistent with the hypothesis that growth factors, such as NGF, form part of the mechanism responsible for sleep regulation and that they also form one facet of sleep-related synaptic plasticity.

Vagotomy attenuates tumor necrosis factor-alpha-induced sleep and EEG delta-activity in rats

Much evidence suggests that tumor necrosis factor-alpha (TNF-alpha) is involved in the regulation of physiological sleep. However, it remains unclear whether peripheral administration of TNF-alpha induces sleep in rats. Furthermore, the role of the vagus nerve in the somnogenic actions of TNF-alpha had not heretofore been studied. Four doses of TNF-alpha were administered intraperitoneally just before the onset of the dark period. The three higher doses of TNF-alpha (50, 100, and 200 microg/kg) dose dependently increased nonrapid eye movement sleep (NREMS), accompanied by increases in electroencephalogram (EEG) slow-wave activity. TNF-alpha increased EEG delta-power and decreased EEG alpha- and beta-power during the initial 3 h after injection. In vagotomized rats, the NREMS responses to 50 or 100 microg/kg of TNF-alpha were attenuated, while significant TNF-alpha-induced increases in NREMS were observed in a sham-operated group. Moreover, the vagotomized rats failed to exhibit the increase in EEG delta-power induced by TNF-alpha intraperitoneally. These results suggest that peripheral TNF-alpha can induce NREMS and vagal afferents play an important role in the effects of peripheral TNF-alpha and EEG synchronization on sleep. Intraperitoneal TNF-alpha failed to affect brain temperature at the doses tested, thereby demonstrating that TNF-alpha-induced sleep effects are, in part, independent from its effects on brain temperature. Results are consistent with the hypothesis that a cytokine network is involved in sleep regulation.

A study of hemorheological behaviour for patients with Alzheimer's disease at the early stages

To evaluate the change of hemorheological indexes for patients with Alzheimer's disease (AD) at the early stages and to discuss effects of these changes on AD, high shear value of whole blood viscosity (etabh), reduced high shear value of whole blood viscosity (retabh), low shear value of whole blood viscosity (etabl), reduced low shear, value of whole blood viscosity (retabl), KT value of whole blood viscosity, hematocrit (HCT) and blood plasma viscosity (etaP) were measured in 31 patients with probable AD at the early stages and 33 age-matched healthy subjects. There were significant differences of all hemorheological indexes between AD group and control group except HCT. Step discriminant analysis revealed 81.25% of overall group-classified accuracy in a hemorheological discriminant function consisting of etabl, retabl, retabh and HCT. Significant difference of hemorheological indexes existed between AD and age-matched healthy control subjects. The results showed that measurement of hemorheological indexes could be used as one of reference standards of diagnosis in AD.

Solvation of acylium fragment ions in electrospray ionization quadrupole ion trap and Fourier transform ion cyclotron resonance mass spectrometry

In electrospray ionization (ESI) quadrupole ion trap and Fourier transform ion cyclotron resonance mass spectrometry, certain fragment ions (e.g. acylium ions) generated either during the ion transportation process (in the source interface region) or in the ion trap are found to undergo ion--molecule reactions with ESI solvent molecules (water, acetonitrile and aliphatic alcohols) to form adduct species. These unexpected solvated fragment ions severely complicate the interpretation of mass spectrometic data. High-resolution accurate mass measurements are important in establishing the elemental compositions of these adduct species and preventing erroneous data interpretation.

A spontaneous recurrent seizure-related Rattus NSF gene identified by linker capture subtraction

Spontaneous recurrent seizures (SRS) are the major clinical characteristic of epilepsy. In this study, using a SRS-behavior test combined with linker capture subtraction (LCS) to identify genes altered in their expression in response to a single kainic acid (KA)-induced SRS at 3 weeks in the rat hippocampal formation. Dot blot analysis of the differentially expressed cDNA fragments with LCS showed the down-regulation of one cDNA related to SRS, which was designated epilepsy-related gene 1 (ERG1). Northern blot analysis showed that ERG1 mRNA was reduced by KA administration with and without SRS, but more so with SRS. This differential expression had also been confirmed by in situ hybridization, which showed that ERG1 mRNA was down-regulated in the dorsal dentate granule cells (dDGCs) of the hippocampal formation, but remarkable up-regulated in the amygdalohippocampal area (AHi), posteromedial cortical amygdaloid nucleus (PMCo) and perirhinal cortex (PRh). The complete cDNA of ERG1 was cloned, sequenced (AF142097). It encodes a Rattus homologue of N-ethylmaleimide-sensitive fusion protein (NSF), which is an ATPase that plays a key role in mediating docking and/or fusion of transport vesicles in the multi-step pathways of vesicular transport. Sequence analysis revealed that ERG1 has high sequence similarity with the cDNA of the Mus musculus suppressor of K(+) transport growth defect (SKD2), N-ethylmaleimide(NEM)-sensitive fusion protein of Chinese hamster and human NEM-sensitive factor (HSU03985).

[Influence of free radical inducer on the level of oxidative stress in brain of rats with fluorosis]

OBJECTIVE

To study changes in content of lipid peroxide and composition of fatty acids in the brain of rats affiliated with chronic fluorosis after treatment with free radical inducer (ferric ion).

METHODS

Thirty-six Wistar rats were divided into three groups, fed with similar fodder and varied concentrations of fluoride in drinking water, and were killed five months after treatment. Lipid peroxidation was induced by ferric ions. Malondialdehyde content in brain was analysed by high-performance liquid chromatography; oxygen consumption was determined with an oxygen electrode and fatty acid composition was measured by gas chromatography in brain tissues of the rats.

RESULTS

In the brain tissues, content of malondialdehyde and oxygen consumption increased, composition of polyunsaturated fatty acids decreased and that of saturated fatty acids decreased after treatment with free radical inducer in the treated group, as compared with those in control group.

CONCLUSION

Over uptake of fluoride for a long term could cause potential increase in the level of oxidative stress in the brain tissue.

T-cell activation and receptor downmodulation precede deletion induced by mucosally administered antigen

The fate of antigen-specific T cells was characterized in myelin basic protein (MBP) T-cell receptor (TCR) transgenic (Tg) mice after oral administration of MBP. Peripheral Th cells are immediately activated in vivo, as indicated by upregulation of CD69 and increased cytokine responses (Th1 and Th2). Concurrently, surface TCR expression diminishes and internal TCR levels increase. When challenged for experimental autoimmune encephalomyelitis during TCR downmodulation, Tg mice are protected from disease. To characterize Th cells at later times after antigen feeding, it was necessary to prevent thymic release of naive Tg cells. Therefore, adult Tg mice were thymectomized before treatment. TCR expression returns in thymectomized Tg mice 3 days after MBP feeding and then ultimately declines in conjunction with MBP-specific proliferation and cytokine responses (Th1-type and Th2-type). The decline correlates with an increase in apoptosis. Collectively, these results demonstrate that a high dose of fed antigen induces early T-cell activation and TCR downmodulation, followed by an intermediate stage of anergy and subsequent deletion.

[Reconstruction of hip, knee, and ankle bony fused in non-functional position of ankylosing spondylitis patients]

OBJECTIVE

To evaluate the reconstruction of hip, knee and ankle joints with bony fusion at non-functional positions for patients with severe late-stage ankylosing spondylitis (AS).

METHODS

From January 1996 to May 1997, simultaneous ipsilateral total hip, knee and ankle replacement was performed under single anesthesia on 2 patients (3 sides) with multiple joint deformity including bony fusion at non-functional positions. They were followed for 29 months on average.

RESULTS

Satisfactory range of motion and function were observed. HSS knee score on average was improved by 45 points and Harris hip score by 37.7 points. There were no wound healing problems or late infection. No aseptic loosening was found.

CONCLUSIONS

Simultaneous ipsilateral total hip, knee and ankle replacement not only reduced cost for hospitalization, but also facilitated early rehabilitation. To our knowledge, this is the first report on this type of surgery, named ipsilateral tri-arthroplasty.

[Study on the genetic difference of SEO type Hantaviruses]

OBJECTIVE

To understand the genetic type of Hantaviruses and the difference between them caused by rodents in Beijing and to furhter explore the source of the infectious factors.

METHODS

Hantavirus RNA, isolated from lungs of rodents captured in Beijing and positive with Hantavirus antigens with frozen sectioning and Immunofluorescent assay, were reverse-transcribed and amplified with PCR with Hantavirus-specific primers.

RESULTS

Five of the PCR amplifications were discovered and sequenced with 300 bp sequence data of M segments (from 2003 - 2302nt according cDNA of seoul 8039 strain). Nucleotide sequence homology showed that they were sequences of SEO-type Hantavirus. Compared with SEO type Hantavirus, the nucleotide sequence homology of these samples was more than 94% while the homology of amonia acid sequence was more than 98%. When compared with HNT type Hantavirus, the homology of nucleotide sequence became less than 72% with the homology of amonia acid sequence less than 81%. Similar to other Hantavirus of SEO type, their nucleotide sequences and deduced amino acid sequences were highly preserved. Phylogenetic tree analysis showed that the five viruses could be divided into at least 4 branches.

CONCLUSION

It was quite likely that there were at least two sub-type SEO viruses with 4 branches that were circulating in Beijing.

Mushroom body defect, a gene involved in the control of neuroblast proliferation in Drosophila, encodes a coiled-coil protein

Neurogenesis relies on the establishment of the proper number and precisely controlled proliferation of neuroblasts, the neuronal precursor cells. A role for the mushroom body defect (mud) gene in both of these aspects of neuroblast behavior, as well as possible roles in other aspects of fruit fly biology, is implied by phenotypes associated with mud mutations. We have localized mud by determining the sequence change in one point mutant, identifying a predicted ORF affected by the mutation, and showing that an appropriate segment of the genome rescues mud mutant phenotypes. An analysis of mud cDNAs and a survey of mud transcripts by Northern blotting indicate that the gene is subject to differential splicing and is expressed primarily during embryogenesis but also, at lower levels, during subsequent developmental stages in a sexually dimorphic manner. The gene is predicted to encode a polypeptide without obvious homologs but with two prominent structural features, a long coiled coil that constitutes the central core of the protein and a carboxyl-terminal transmembrane domain.

Influence of lipid peroxidation on the nicotinic acetylcholine receptors in PC12 cells

The expression of neuronal nicotinic acetylcholine receptors (nAChRs) influenced by lipid peroxidation has been investigated. The results showed that exposure of PC12 cells to a free radical insult (FeSO(4)) induced concentration-dependent increase in level of MDA (malondialdehyde), and a significant decline in MTT [3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide] reduction. In cultured cells exposed to FeSO(4), a significant dose-dependent decrease in [(3)H] epibatidine binding sites was detected and a significant reduction in B(max) value was observed in the high affinity epibatidine binding site. These results demonstrate that lipid peroxidation in cellular membranes can induce a reduction in numbers of neuronal nAChRs.

[The research progress of using electromagnetic technology in treatment of bone diseases]

In these years, the study of the bioeffects of electromagnetic fields (EMFs) has been listed as the national important task in the field of biological physics. Using EMFs to treat bone diseases is associated with electric technology, biology and medicine. Previous medical studies have shown that EMFs can stimulate healing in bone fractures. But the effects are still controversial and the mechanism is not yet clear. Therefore, it is necessary to carry out experiments in vitro at cellular and molecular levels. Research workers have been exploring the effects of EMFs on bone formation and metabolism. The suggestion of using EMFs in the treatment of osteoporosis and other osseous diseases has been put forward.

[Role of interleukin-6 and platelet-activating factor in delaying neutrophil apoptosis]

In the present study we investigated the role of platelet-activating factor (PAF) and interleukin-6 (IL-6) in delaying polymorphonuclear neutrophil (PMN) apoptosis. Isolation of PMN was performed by using the discontinuous plasma-Percoll gradient technique. PMN was cultured in enriched RPMI 1640 media at 2 x 10(7) PMN/ml for 24 h. Subgroups were treated with IL-6 or PAF or pretreated with PAF receptor antagonist BN52021 before IL-6 or PAF were added. Morphological assessment and quantitation of apoptosis were performed with acrodine/ethidium bromide stain and epifluorescent microscope. The results showed that both IL-6 and PAF suppressed PMN apoptosis. Pretreatment of PMN with BN52021 abrogated the effects of IL-6 and PAF. It is suggested that PAF may be a crucial cytokine in the suppression of PMN apoptosis. These observations may contribute to elucidating the mechanisms of IL-6 and PAF in mediating postinjury hyperinflammation and secondary organ dysfunction and provide a clue for the prevention and treatment of the conditions.

Traumatic spinal cord injury produced by controlled contusion in mouse

Previous work from this laboratory has described a rat spinal cord injury (SCI) model in which the mid-thoracic spinal cord is subjected to a single rapid and calibrated displacement at the site of a dorsal laminectomy. Injury is initiated at the tip of a vertical shaft driven by an electromagnetic shaker. Transducers arranged in series with the shaft record the patterns of displacement and force during the impact sequence. In the present study, this device and the relevant surgical procedures were adapted to produce a spinal contusion injury model in laboratory mice. The signal generator for the injury device has also been converted to a computer-controlled interface to permit extension of the model to other laboratories. Mice were subjected to SCI across a range of severities by varying the amplitude of displacement and the magnitude of measured preload force on the dural surface. A moderate injury produced by displacement of 0.5 mm over 25 msec resulted in initial paralysis and recovery of locomotion with chronic deficits in hindlimb function. The magnitude of the peak force, impulse, power, and energy generated at impact were correlated with behavioral outcome at 1 day postinjury, while peak displacement and impulse were the best predictors of behavioral outcome at 28 days postinjury. The shape of the force recording proved to be a highly sensitive measure of subtle variations in the spinal compartment that were otherwise difficult to detect in this small species. The results demonstrate that the electromagnetic spinal cord injury device (ESCID) can be used to produce a well-controlled contusion injury in mice. The unique features of controlled displacement and monitoring of the biomechanical parameters at the time of impact provide advantages of this model for reducing outcome variability. Use of this model in mice with naturally occurring and genetically engineered mutations will facilitate understanding of the molecular mechanisms of pathophysiology following traumatic spinal cord injury.

[Risk factors for nosocomial infections after total knee replacement]

OBJECTIVE

To investigate prevalence and risk factors of nosocomial infections in patients with total knee replacement.

METHODS

From August 1993 to October 1998, total knee replacement was performed on 363 patients (503 knees). The difference of nosocomial infection rates was statistically analyzed in comparison with different age, primary disease, and associated disease groups.

RESULTS

No statistically significant difference was observed in nosocomial infection when compared rheumatoid arthritis with osteoarthritis, bilateral total knee replacement (TKR) with unilateral TKR and different ages. However, the higher nosocomial infection rate was related to the following factors: revision surgery, steroid administration and diabetes urinary infection. 28 female patients demonstrated higher urinary infection rate than that in other systems.

CONCLUSIONS

Nosocomial infection rate of TKR in rheumatoid cases is related to steroid administration, accompanying diabetes mellitus, previous knee surgery, aged women and retention of urinary catheter. It is feasible to prevent nosocomial infection by controlling the above-mentioned risk factors.

A new assay for the genetic study of general anesthesia in Drosophila melanogaster: use in analysis of mutations in the X-chromosomal 12E region

We describe a new measure of the influence of general anesthetics on Drosophila that uses the robust tendency of fruit flies to briskly walk upwards after being tapped down. We expose flies to a fixed concentration of anesthetic gas in a 50 ml tube for a period of up to 1 h and then test the distribution of flies in the tube shortly after tapping them to its bottom. By measuring the effect of a series of anesthetic concentrations on the fraction of flies that fail to climb, we derive quantitative descriptors of the potency of the drug. This "distribution test" is superior to previous assays of anesthetic potency in terms of ease and reliability. We have used the assay to further the genetic analysis of several mutations that cluster on the X chromosome and are known to influence both neural function and anesthesia sensitivity. The results establish complementation patterns between the mutations, refine their genetic map positions, and open the way for the molecular identification of the relevant gene(s).

[Kinetics of plasma membrane and mitochondrial alterations in HL-60 cells undergoing apoptosis]

In the present study, VP16, an inhibitor of topoisomerase II, and NaN3, a chemical toxic substance, were used to induce apoptosis and necrosis of HL-60 cells, respectively. Cells were examined by transmission electron microscopy and by fluorescence microscopy after staining with Hoechst 33258 at 0, 2, 4, 8, 16 and 24 h of culture. Alterations of fluorescent intensity produced by FDA, Rh 123 and PI were measured by flow cytometry, which reflects sequential changes on plasma membrane permeability and the potential of mitochondrial membrane. The results indicated that the nuclear morphologic alteration of cells treated with VP-16 began at 4 hour of culture and the cells with condensed nucleus culminated at 8 h of culture and then reduced with no drop in cell counts, while the percentage of cells with fragmented nuclei reached its maximum at 24 h of culture accounting for some 80%. The potential of mitochondrial membrane of of apoptotic cells decreased gradually from 8 h of culture and showed obvious decline at 16 h of culture. In necrotic cells, the potential decreased by 50% at 4 h of culture which indicates an earlier and more rapid decline than that in apoptotic cells. Alteration of plasma membrane permeability appeared at 8 h of culture and showed a steady increase over time. It was concluded that plasma membrane permeability and mitochondrial membrane potential could reflect the development and degree of apoptosis, and the combination of these two criteria with nuclear morphology revealed by staining with Hoechst 33258 would be a simple and reliable assay for apoptosis and its progression.