Bacteria isolated from surgical infections and its susceptibilities to antimicrobial agents--special references to bacteria isolated between april 2003 and march 2004

Tendency of isolated bacteria from infections in abdominal surgery during the period from April 2005 to March 2006 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, 384 strains including 18 strains of Candida spp. were isolated from 161 (70.3%) of 229 patients with surgical infections. One hundred and ninty-five strains were isolated from primary infections, and 171 strains were isolated from postoperative infections. From primary infections, aerobic Gram-negative bacteria and aerobic Gram-positive bacteria were predominant, while aerobic Gram-positive bacteria were predominant from postoperative infections. The isolation rate of aerobic Gram-positive bacteria, such as Enterococcus spp. and Staphylococcus aureus were higher from both types of infections. Among anaerobic Gram-positive bacteria, the isolation rate of Peptostreptococcus spp. was the highest from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Pseudomonas aeruginosa, Klebsiella spp. in this order, and from postoperative infections, E. coli was the most predominantly isolated, followed by Klebsiella pneumoniae and P. aeruginosa. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both primary and postoperative infections. In this series, we noticed no vancomycin-resistant Gram-positive cocci, nor multidrug-resistant P. aeruginosa. But cefazolin-resistant E. coli producing extended spectrum fl-lactamase was seen in 5.0 per cents. We should be carefully followed up the facts that the increasing isolation rates of B. fragilis group and Bilophila wadsworthia which were resistant to both penicillins and cephems.     

Paclitaxel-2′-Ethylcarbonate Prodrug Can Circumvent P-glycoprotein-mediated Cellular Efflux to Increase Drug Cytotoxicity

Purpose The aim of the study was to investigate whether 2′-ethylcarbonate-linked paclitaxel (TAX-2′-Et) circumvents P-glycoprotein (P-gp)-mediated cellular efflux and cytotoxicity enhanced by TAX-2′-Et activation within human culture cells transfected with a rabbit liver carboxylesterase (Ra-CES) cDNA. Materials and Methods TAX-2′-Et transport was characterized in a human colon carcinoma cell line (Caco-2) and paclitaxel (TAX)-resistant ovarian carcinoma cells (SKOV3/TAX60). Expression of P-gp, multidrug resistance protein (MRP) 2 and Ra-CES was detected by Western blotting. Cytotoxicity against Ra-CES-expressing cells and cellular amount of TAX produced were determined by MTT assay and using HPLC, respectively. Results Unlike rhodamine123 and TAX, TAX-2′-Et did not exhibit polarized transport in the Caco-2 cells in the absence or presence of verapamil. P-gp levels were expressed much higher in the SKOV3/TAX60 cells than in the Caco-2 cells. MRP2 protein was not detectable in the SKOV3/TAX60 cells. Uptake by the SKOV3/TAX60 cells was similar in quantity to the amount internalized by P-gp-negative SKOV3 cells. In the SKOV3/TAX60 cells, cellular uptake of TAX-2′-Et was not altered regardless of the absence or presence of verapamil. The cytotoxicity to the untransfected SKOV3 cells induced by TAX-2′-Et was significantly lower than that induced by TAX. In the Ra-CES-expressing SKOV3 line, the EC₅₀ value of TAX (10.6 nM) was approximately four-fold higher than that of TAX-2′-Et (2.5 nM). Transfection of Ra-CES into another TAX-resistant ovarian carcinoma cells (KOC-7c) conferred a high level of TAX-2′-Et cytotoxicity via prodrug activation. The intracellular levels of TAX produced from TAX-2′-Et in the Ra-CES-positive KOC-7c cells significantly increased compared with the levels seen in exposure of the untransfected KOC-7c cells to TAX. Conclusions TAX-2′-Et can circumvent P-gp-associated cellular efflux of TAX. TAX-2′-Et is converted into TAX by the Ra-CES, supporting its potential use as a theoretical GDEPT strategy for cancer cells expressing high levels of P-gp. The TAX-2′-Et prodrug efficiently increased the amount of intracellular TAX, which mediates tumor cell death.     

Pharmacological characterization of 5-Hydroxytryptamine-receptor subtypes in circular muscle from the rat stomach

5-Hydroxytryptamine (5-HT) modulates gastric motility and gastric emptying via a variety of 5-HT receptor subtypes. However, regional and functional differences among 5-HT receptor subtypes in the rat stomach are not fully investigated. Thus, we aimed to characterize 5-HT receptor subtypes involved in the 5-HT-induced contractions in the isolated antral, corporal and fundic circular muscles of the rat stomach by measuring the contractile force. 5-HT induced concentration-dependent contractions in the antrum, corpus and fundus. 5-HT-induced antral contractions were partly blocked by atropine and enhanced by tetrodotoxin (TTX). Neither atropine nor TTX affected the corporal or the fundic contractions to 5-HT. In the antrum, 5-HT-induced contractions were inhibited by methysergide, tended to be inhibited by ketanserin, enhanced by SB-203186, but were not affected by WAY-100635, GR127935, RS-127445, ondansetron, or SB-269970. In the corpus, 5-HT-induced contractions were inhibited by ketanserin or methysergide. In the fundus, 5-HT-induced contractions were blocked by methysergide or RS-127445, but were enhanced by cinanserin or SB-203186. It is thus concluded that contractile responses to 5-HT in the antrum are mediated by 5-HT receptors on both smooth muscle and neurons whilst in the corpus and fundus responses are mainly mediated by 5-HT receptors on smooth muscle. Moreover, the antrum presents the contractile 5-HT2A and 5-HT2B receptors and the relaxant 5-HT4 receptors. The corpus presents the contractile 5-HT2A receptors, and the fundus presents the contractile 5-HT2B receptors and the relaxant 5-HT2A and 5-HT4 receptors.     

Sex change in the Gobiid fish is mediated through rapid switching of gonadotropin receptors from ovarian to testicular portion or vice versa

Sex-changing fish Trimma okinawae can change its sex back and forth from male to female and then to male serially, depending on the social status in the harem. T. okinawae is well equipped to respond to its social status by possessing both ovarian and testicular tissues even though only one gonad remains active at one time. Here we investigated the involvement of gonadotropins in sex change by determining the changes in gonadotropin receptor (GtHR) gene expression during the onset of sex change from female to male and male to female. The expression of the GtHR was found to be confined to the active gonad of the corresponding sexual phase. During the sex-change from female to male, initially the ovary had high levels of FSHR and LHR, which eventually went up in the testicular tissue if the fish was bigger. Changing of the gonads started with switching of GtHR expression discernible within 8-12 h of the visual cue. Further in vitro culture of the transitional gonads with a supply of exogenous gonadotropin (human chorionic gonadotropin) revealed that the to-be-active gonad acquired the ability to produce the corresponding sex hormone within 1 d of the activation of GtHR. Conversely, the to-be-regressed gonad did not respond to the exogenous gonadotropin. Our findings show that the gonads of successive sex-changing fish possess the intrinsic mechanism to respond to the social cue differentially. Additionally, this location switching of GtHR expression also could substantiate the importance of the hypothalamo-pituitary-gonadotropic axis.     

4-Hydroxy-2-nonenal Induces Calcium Overload via the Generation of Reactive Oxygen Species in Isolated Rat Cardiac Myocytes

BackgroundIt has been reported that that the amount of 4-hydroxy-2-nonenal (HNE), which is a major lipid peroxidation product and a cytotoxic aldehyde, is increased in the human failing myocardium. This study was designed to determine whether HNE has a pro-oxidant effect in cardiac myocytes and whether HNE causes Ca²⁺ overload.Methods and ResultsExposure to HNE for 10 minutes in the presence of ferric nitrilotriacetate induced the production of hydroxyl radical (·OH) in the rat myocardium as assessed by electron spin resonance spectroscopy, and HNE induced the generation of reactive oxygen species (ROS) in a dose-dependent manner as assessed by 2′, 7′-dichlorofluorescein diacetate fluorescence. HNE increased intracellular Ca²⁺ concentration ([Ca²⁺]_i) as assessed by fura-2 ratio in a dose- and time-dependent manner. After 20 minutes of HNE (400 μmol/L) exposure, hypercontracture was induced in 67% of the cells. Catalase, an antioxidative enzyme that can decompose hydrogen peroxide (H₂O₂), significantly attenuated the increase in [Ca²⁺]_i and completely inhibited hypercontracture. Carvedilol, a β-blocker with potent antioxidant activity, also significantly attenuated the increase in [Ca²⁺]_i and completely inhibited hypercontracture, but propranolol had no effect on either [Ca²⁺]_i increase or hypercontracture.ConclusionsHNE induces the formation of ROS, especially H₂O₂ and ·OH, in cardiomyocytes and subsequently ROS cause intracellular Ca²⁺ overload. HNE formation may play an important role as a mediator of oxidative stress in heart failure.     

Choleretic effect of inchinkoto, a herbal medicine, on livers of patients with biliary obstruction due to bile duct carcinoma

Aim:  To investigate the choleretic effects of inchinkoto (ICKT) on livers of patients with biliary obstruction due to bile duct carcinoma.
Methods:  Twenty-seven patients with bile duct carcinoma who were due to undergo biliary drainage and subsequent major hepatectomy were randomly assigned to preoperative ICKT ( n  = 13) or untreated ( n  = 14) groups. ICKT was administered from the day of admission until one day before surgery. Changes in bile constituents, expression of multidrug resistance-associated protein (MRP) 2, MRP3 and MRP4 in the liver, and the incidence of postoperative complications were included as end-points.
Results:  The biliary concentration of total bilirubin was significantly increased after administration of ICKT (23.7 ± 2.8 mg/dL before ICKT; 34.0 ± 4.0 mg/dL after ICKT, P  < 0.05). The biliary concentration of total bile acids was also significantly increased. Protein levels of MRP2 and MRP3 in the crude plasma membrane fraction of livers of treated patients were significantly higher than those without treatment. MRP2 staining in the livers of patients without ICKT treatment was weak and diffuse around the bile canaliculi, whereas staining in patients with ICKT treatment was strong and restricted to the bile canaliculi.
Conclusion:  ICKT exerts a choleretic effect on the livers of patients with biliary obstruction. This beneficial effect was associated with increased expression of MRP2. ICKT thus has therapeutic potential for treatment for obstructive cholestasis due to bile duct carcinoma.     

Impact of trough serum level on radiographic and clinical response to infliximab plus methotrexate in patients with rheumatoid arthritis: results from the RISING study

This study is a prospective, randomized, double-blind study to compare the efficacy and safety of 10 mg/kg infliximab with those of 3 mg/kg infliximab treatment in methotrexate-refractory rheumatoid arthritis patients. After the patients received 3 mg/kg infliximab infusion at weeks 0, 2, and 6, they were randomly assigned to be administered 3, 6 or 10 mg/kg infliximab every 8 weeks from week 14 to 46. Mean American College of Rheumatology improvement (ACR-N) at week 54, the primary endpoint, was 51.3% and 58.3% for the 3 mg/kg and 10 mg/kg groups, respectively, with a statistically significant difference. Treatment with 10 mg/kg was found to be remarkably beneficial in patients who had not responded to three infusions with 3 mg/kg at week 10. The median changes in the modified Sharp score were 0.0 in the two groups. There were no significant differences in the incidences of adverse events between the groups. In patients who achieved better clinical response or greater inhibition of progression of joint damage, trough serum infliximab level was significantly higher than in patients who did not. The magnitudes of both efficacies were correlated with the trough serum infliximab level (ClinicalTrials.gov number: NCT00691028).     

Rendezvous gastrotomy technique using direct percutaneous endoscopic gastrostomy for transgastric cholecystectomy in hybrid natural orifice translumenal endoscopic surgery

Background/purpose

Transgastric access is a major route in natural orifice translumenal endoscopic surgery (NOTES); gastrotomy should be performed unless it would damage surrounding organs in the peritoneal cavity. This article describes a novel rendezvous gastrotomy technique over a direct percutaneous endoscopic gastrostomy (PEG).

Methods

In six live porcines, the gastrotomy involved applying a direct PEG through the abdominal wall into the stomach and exchanging to a needle trocar. An endoscopic balloon catheter was passed through the trocar by rendezvous technique. Then the inflated balloon and endoscope were advanced to the peritoneal cavity through the gastrotomy. Transgastric cholecystectomy was performed with a hybrid needle grasper through the same percutaneous site and the gastrotomy was closed with endoscopic clips.

Results

The rendezvous gastrotomy technique could reduce guidewire exchange. The success rate was 100% (6/6). Mean times for transgastric peritoneoscopy and cholecystectomy were 25.5 and 83.5 min. Mortality and morbidity was 0%. The addition of the extra trocar was unnecessary in all procedures.

Discussions/conclusions

The advantage of this introduction system includes the creation of controlled gastric perforation, which is easier to close. It provides reliable transgastric access and increases safety. It simplifies transgastric NOTES and provides less invasive hybrid NOTES procedure.     

Intervention of an inflammation amplifier,triggering receptor expressed on myeloid cells 1, for treatment of autoimmune arthritis

Objective

Triggering receptor expressed on myeloid cells 1 (TREM‐1) is inducible on monocyte/macrophages and neutrophils and accelerates tissue destruction by propagating inflammatory responses in disease related to bacterial infections. Its blockade rescues the hosts in murine models of sepsis, to clear the bacteria without impairing the host defense. The aim of this study was to investigate the involvement of TREM‐1 in an autoimmune, noninfectious disease.

Methods

Synovial tissue specimens from the joints of patients with rheumatoid arthritis (RA) and the joints of mice with collagen‐induced arthritis (CIA) were examined for TREM‐1 expression, using flow cytometric analysis. Expression of TREM‐1 on macrophages was induced by lipopolysaccharide, with or without a cyclooxygenase inhibitor. Rheumatoid synovial cells were stimulated with agonistic anti–TREM‐1 antibodies. Recombinant adenovirus encoding the extracellular domain of TREM‐1 fused with IgG‐Fc (AxCATREM‐1 Ig) or synthetic TREM‐1 antagonistic peptides were injected to treat CIA, and the clinical manifestations of the antigen‐specific T cell and B cell responses were evaluated.

Results

TREM‐1 was expressed on CD14+ cells in rheumatoid synovial tissue and synovial macrophages from mice with CIA. Unlike murine macrophages, human monocyte/macrophages did not depend on prostaglandin E₂ for up‐regulation of TREM‐1. Agonistic anti–TREM‐1 antibodies promoted tumor necrosis factor α production from rheumatoid synovial cells. Blockade of TREM‐1 using AxCATREM‐1 Ig and antagonistic peptides ameliorated CIA without affecting the serum levels of anti–type II collagen antibodies or the proliferative responses of splenocytes to type II collagen.

Conclusion

TREM‐1 ligation contributes to the pathology of autoimmune arthritis. The results of this study implied that blockade of TREM‐1 could be a new approach to rheumatic diseases that is safer than the presently available immunosuppressive treatments.