Electrode Contact Force-Controlled Bipolar Radiofrequency Ablation: Different Effects on Lesion Size between Dual- and Single-Bath Preparations

BACKGROUND

During bipolar (BIP) radiofrequency (RF) ablation using two catheters in humans, each catheter is placed in separate cardiac chambers or spaces. We developed a contact force-controlled experimental preparation, and compared measurements made with two catheters placed in a single bath (SB), versus each catheter placed in separate baths, in order to assess the preparation-dependent differences in the results of BIP-RF ablation.

METHODS

In the SB experiments, a porcine heart was placed in the center of the bath, while in the dual-bath (DB) experiments, it was placed between two half baths communicating through windows.

RESULTS

The initial impedance was greatest (110.5 ± 7.2 Ω) with the BIP-DB, followed by the BIP-SB (92.0 ± 5.6 Ω) and the unipolar (UNIP) DB (84.9 ± 4.7 Ω) configurations. During 50-W ablation for 60 seconds at a 20-g contact force, the root mean square voltage was 75.7 ± 2.5 V in the BIP-DB, 68.0 ± 2.1 V in the BIP-SB, and 66.8 ± 2.0 V in the UNIP-DB. The mean surface lesion diameters were similar among the three configurations. However, the endocardial lesion depth was 5.60 ± 0.56 mm with the BIP-DB, 4.71 ± 0.64 mm with the BIP-SB, and 4.24 ± 0.58 mm with the UNIP-DB configuration. On average, the endocardial lesions were significantly deeper than the epicardial ones.

CONCLUSIONS

BIP ablation created much deeper lesions as compared to UNIP ablation. Lesion depth could be different depending on experimental preparation, and contact force-controlled DB preparation may be a much more appropriate model for studying the effects of BIP ablation.

Randomized clinical trial of single-incision versus multiport laparoscopic colectomy

BACKGROUND

The efficacy and safety of single-incision laparoscopic colectomy (SILC) for colonic cancer remain unclear. The aim of this study was to determine the outcomes of SILC compared with multiport laparoscopic colectomy (MPLC) for colonic cancer.

METHODS

Patients with histologically proven colonic carcinoma located in the caecum, ascending, sigmoid or rectosigmoid colon, clinically diagnosed as stage 0-III by CT, were eligible for this study. Patients were randomized before surgery and underwent tumour dissection with complete mesocolic excision. Safety analyses were conducted according to randomization groups.

RESULTS

A total of 200 patients were enrolled and randomized to the MPLC (100 patients) or SILC (100 patients) arm. Surgical outcomes were similar between the MPLC and SILC arms, including duration of operation (mean 162 versus 156 min respectively; P = 0·273), blood loss (mean 8·8 versus 21·4 ml; P = 0·102), conversion to open laparotomy (2·0 versus 1·0 per cent; P = 0·561), reoperation (3·0 versus 3·0 per cent; P = 1·000), time to first flatus (both median 1 day; P = 0·155) and postoperative hospital stay (both median 6; P = 0·372). The total skin incision length was significantly shorter in the SILC arm (mean 4·4 cm versus 6·8 cm in the MPLC arm; P < 0·001). The median duration of analgesia use was 5 days in the MPLC and 4 days in the SILC arm (P = 0·485). Overall complication rates were equivalent (15·0 versus 12·0 per cent respecitvely; P = 0·680).

CONCLUSION

SILC is not superior to MPLC.

REGISTRATION NUMBER

UMIN000007220 (http://www.umin.ac.jp/ctr/index.htm).

In-vitro anti Myxovirus Activity and Mechanism of Antiinfluenzavirus Activity of Polyoxometalates PM-504 and PM-523

Sixty polyoxometalates were examined for anti-influenza A virus (FluV-A) activity in vitro. Two of the most potent and least cytotoxic compounds, PM-504 K9H5(Ge2Ti6W18O77)16H2O] and PM-523 (iPrNH3)6H [PTi2W10O38(O2)9H2O2] were selected for further studies. Examination of the antiviral effects of PM-504 and PM-523 against other human ortho- and paramyxoviruses revealed that both compounds had broad spectrum antimyxovirus activities. From a time of addition study and FACS analysis for influenza A virus infected cells, the compounds were found not to inhibit binding of virus to MDCK cells. However, these compounds inhibited haemolysis of chicken erythrocytes by virus and also inhibited fluorescence dequenching of octadecylrhodamine B-labelled virus after binding to cells. This indicates that these polyoxometalates inhibited fusion of the virus envelope to the cellular membrane.

Antiviral Activity of a Sulphated Polysaccharide Extracted from the Marine Pseudomonas and Marine Plant Dinoflagellata against Human Immunodeficiency Viruses and other Enveloped Viruses

A natural sulphated mucopolysaccharide (OKU40), extracted from a marine plant Dinoflagellata, and an artificial sulphated polysaccharide (OKU41), prepared from a marine Pseudomonas, displayed antiviral activities against several enveloped viruses. OKU40 and OKU41 were found to be homogenous in electrophoresis and sedimation velocity and had a molecular weight of 8.0 × 1065.0 × 105respectively. The sulphation rate of OKU40 and OKU41 was 8.9% and 5.4%, respectively. Each OKU40 and OKU41 inhibited the cytopathic effect of human immunodeficiency virus type 1 (HIV-1), type 2 (HIV-2) and zidovudineresistant HIV-1 in MT-4 cells at similar concentrations to those of dextran sulphate (molecular weight: 5000) (50% inhibitory concentrations: 0.86-1.95 μg mL−1), whereas these compounds did not affect the growth and viability of mock-infected MT-4 cells at concentrations up to 500 μg mL−1. These compounds proved inhibitory not only to HIV-1 and HIV-2 but also to other enveloped viruses, i.e. herpes simplex virus type 1, influenza virus A and B, respiratory syncytial virus and measles virus. OKU40 and OKU41 suppressed syncytium formation induced by cocultivation of MOLT-4/IIIb and MOLT-4 cells at concentrations higher than 20 μg mL−1. Although OKU41 inhibited the binding of HIV-1 to the host cells and the binding of anti-gp120 monoclonal antibody to HIV-1 gp120, OKU40 did not inhibit these bindings, suggesting that the mechanism of anti-HIV activity of OKU40 and OKU41 may be primarily due to the inhibition of virus-cell fusion and viral adsorption to the host cells, respectively. Furthermore, these compounds did not inhibit to the blood coagulation process at a concentration that was significantly inhibitory to HIV replication. The compounds appear to have an interesting potential as virucidal agents.

In vitro Antimyxovirus and Anti-Human Immunodeficiency Virus Activities of Polyoxometalates

Polyoxometalates have been shown to inhibit the replication of retro-, toga-, paramyxo- and herpesviruses. The primary mechanism of the anti-human immunodeficiency virus type 1 (HIV-1) action of polyoxometalates seems to be inhibition of binding of virus to cells and inhibition of syncytium formation. Since myxoviruses and HIV-1 are known to interact with the cytoplasmic membrane by adsorption and penetration of virus and by fusion of infected and uninfected cells, 25 polyoxometalates were examined for anti-ortho-, anti-paramyxovirus and anti-HIV-1 activity in vitro. Of the 25 compounds evaluated, 24 showed antiviral effects against influenza virus A, 11 showed activity against respiratory syncytial virus, six showed activity against measles virus, and 23 were considered effective against HIV-1 at a lower concentration than that producing cytotoxicity. Four polyoxotungstates which had potent inhibitory effects were examined for inhibitory effects against additional ortho- and paramyxoviruses, and proved to have a broad spectrum of antimyxoviral activity. HS-058, the Keggin sandwich compound K10Fe4(H2O)2(PW9O34)2·nH2O, was inhibitory against influenza viruses A and B, respiratory syncytial virus, measles virus, and parainfluenza virus 2, with median effective concentrations of 1.4, 21.8, 7.4, 0.8 and 0.32 μ,M, respectively. However, HS-058 had no effect on parainfluenza virus 3 or mumps virus. The median cytotoxic concentration of HS-058 for Madin-Darby canine kidney (MDCK) and HEp-2 cells was more than 200 μM and that for HMV-2 and Vero cells was about 50 μM. When HS-058 was added at different times after influenza A and respiratory syncytial virus infection, it inhibited binding of the latter but not of the former to cells. However, at higher concentrations, HS-054 and HS-058 inhibited haemolysis of chick erythrocytes by influenza virus and syncytium formation involving respiratory syncytial virus-infected cells and uninfected cells. Four times the median effective antiviral concentration of HS-058 completely inhibited the growth of influenza virus A in MDCK cells when compound was added before virus adsorption. Furthermore, when HS-058 was added after virus adsorption, it inhibited the yield of virus in MDCK cells infected at low but not at high multiplicity of infection.

Antiviral Activities of Mizoribine and other Inosine Monophosphate Dehydrogenase Inhibitors against Several Ortho- and Paramyxoviruses

Mizoribine (4-carbamoyl-1-β-D-ribofuranosylimidazo-lelium-5-olate), EICAR (5-ethynyl-1-β-D-ribofuranosylimi-dazole-4-carboxamide), mycophenolic acid and ribavirin are antiviral agents targeted for inosine monophosphate (IMP) dehydrogenase. These compounds have been examined for their activities against orthomyxoviruses [influenza viruses (FluV)] and paramyxoviruses [parainfluenza viruses (PFIuV), mumps virus, measles virus (MLSV) and respiratory syncytial virus (RSV)] in vitro. Mizoribine was 1- to 9-fold more active than ribavirin against RSV, PFIuV and MLSV. EICAR and mycophenolic acid showed higher potency than mizoribine and ribavirin against all myxoviruses examined. None of the four compounds examined proved cytotoxic to stationary host cells (HeLa, Vero and MDCK) at a concentration of 200 μg ml−1 or more. On the other hand, EICAR and mycophenolic acid were toxic to rapidly growing cells at concentrations of 2.2-9 and 0.1-1.1 μg ml−1, respectively. Mizoribine and ribavirin showed cytotoxicity to the growing cells at higher concentrations (12-51 μg ml−1). The antiviral activities of mizoribine against FluV and RSV were reversed by 25-100 μm of each of guanosine and guanosine monophosphate (GMP). The antiviral activity of ribavirin against FluV was reversed by 25 μg of each of guanosine and GMP, while its activity against RSV was reversed by ≥ 100 μm of each of these compounds. Neither xanthosine nor xanthosine monophosphate (XMP) reversed the antiviral effects of mizoribine and ribavirin at concentrations of 300 μM. Concentrations 9 times higher than the median effective doses (EC50) of mizoribine and ribavirin inhibited the growth of RSV in HeLa cells as determined in an assay of infectious virus yield. Mizoribin should be further pursued as a candidate drug for the treatment of ortho- and paramyxovirus infections.

Nutritional management of anastomotic leakage after colorectal cancer surgery using elemental diet jelly

BACKGROUND/AIMS

Anastomotic leakage is major complication of colorectal surgery. Total parenteral nutrition (TPN) and fasting are conservative treatments for leakage in the absence of peritonitis in Japan. Elemental diet (ED) jelly is a completely digested formula and is easily absorbed without secretion of digestive juices. The purpose of this study was to assess the safety of ED jelly in management of anastomotic leakage.

METHODOLOGY

Six hundred and two patients who underwent elective surgery for left side colorectal cancer from January 2008 to December 2011 were included in the study. Pelvic drainage was performed for all patients. Sixty-three (10.5%) patients were diagnosed with an anastomotic leakage, and of these, 31 (5.2%) without diverting stoma were enrolled in this study.

RESULTS

Sixteen patients received TPN (TPN group) and 15 patients received ED jelly (ED group). The duration of intravenous infusion was significantly shorter in the ED group than in the TPN group (15 days versus 25 days, P= 0.008). In the TPN group, catheter infection was occurred in 2 patients who required re-insertion of the catheter.

CONCLUSION

Conservative management of anastomotic leakage after colorectal surgery with ED jelly appears to be a safe and useful approach.

Effect of risperidone metabolism and P-glycoprotein gene polymorphism on QT interval in patients with schizophrenia

Risperidone (RIS) is a frequently used efficacious psychotropic drug. However, it prolongs the QTc interval and may cause fatal arrhythmia. Little is known on the determinants of this RIS side effect. RIS is metabolized by CYP2D6, and is subject to drug efflux by P-glycoprotein (P-gp) encoded by the ATP-binding cassette subfamily B member 1 (ABCB1) gene. P-gp removes both RIS and its metabolite 9-OH-RIS from cardiac tissue. To investigate the effect of RIS metabolism and ABCB1 gene polymorphisms on QTc, steady-state plasma RIS and 9-OH-RIS levels, and QTc were measured. CYP2D6, ABCB1 C3435T and G2677T/A genotypes were determined in 66 schizophrenia patients on RIS. QTc was significantly longer in patients with ABCB1 3435CT+3435 TT than in those with 3435CC (P=0.006). ABCB1 G2677T/A genotype did not affect QTc. Multiple regression analysis showed that C/T or T/T genotypes at the ABCB1 C3435T locus, lower weight, and older age prolonged QTc. In summary, the T allele of the ABCB1 C3435T genotype should be considered in future diagnostic development efforts for RIS-associated QT.

An open-label, dose-escalation, safety, and pharmacokinetics phase I study of ombrabulin, a vascular disrupting agent, administered as a 30-min intravenous infusion every 3 weeks in Japanese patients with advanced solid tumors

PURPOSE

To determine ombrabulin's maximum tolerated dose and dose recommended for Japanese patients with advanced solid tumors and to assess its antitumor activity and overall safety and pharmacokinetic profiles.

METHODS

This was a multi-center, open-label, sequential-cohort, dose-escalation phase I study of ombrabulin, a vascular disrupting agent, administered once every 3 weeks. Patients were treated with 15.5, 25, 35, or 50 mg/m(2) ombrabulin over a 30-min intravenous infusion. The recommended dose was the highest dose at which <33 % of all evaluable patients experienced dose-limiting toxicities (DLTs) during the first treatment cycle or 50 mg/m(2) (recommended in Caucasian patients) if the previous definition was not met.

RESULTS

Fifteen patients were treated. No DLT occurred with 15.5, 25, or 35 mg/m(2) ombrabulin. In the 50 mg/m(2) group, one patient had Grade 3 lymphopenia, and another experienced Grade 2 hypertension and Grade 3 diarrhea judged as DLTs. The most frequent related adverse events in this group were diarrhea, nausea, and hypertension. Two patients had Grade 3 anemia, one at the 15.5 mg/m(2) and the other at the 50 mg/m(2). No AEs necessitating dose reduction or Grade 4 AEs were observed. Overall, five patients had stable disease. Pharmacokinetic parameters were comparable to those in non-Japanese patients.

CONCLUSIONS

Ombrabulin treatment once every 3 weeks was well tolerated in Japanese patients with advanced solid tumors. The dose recommended is 50 mg/m(2), as in Caucasian patients. The safety and pharmacokinetic profiles were comparable between Japanese and Caucasian patients (funded by Sanofi; ClinicalTrials.gov number, NCT00968916).