Prolonged treatment of Salmonella enterica serovar Typhimurium with commercial disinfectants selects for multiple antibiotic resistance, increased efflux and reduced invasiveness

OBJECTIVES: To study how disinfectants affect antimicrobial susceptibility and phenotype of Salmonella enterica serovar Typhimurium SL1,344. METHODS: Wild-type strain SL1,344 and its isogenic gyrA mutant were passaged daily for 7 days in subinhibitory concentrations, and separately for 16 days in gradually increasing concentrations of a quaternary ammonium disinfectant containing formaldehyde and glutaraldehyde (QACFG), an oxidizing compound blend (OXC), a phenolic tar acids-based disinfectant (TOP) and triclosan. The MICs of antimicrobials and antibiotics for populations and representative isolates and the proportion of cells resistant to the MICs for the wild-type were determined. Expression of acrB gene, growth at 37 degrees C and invasiveness of populations in Caco-2 intestinal epithelial cells were assessed. RESULTS: QACFG and triclosan showed the highest selectivity for variants with reduced susceptibility to chloramphenicol, tetracycline, ampicillin, acriflavine and triclosan. Populations treated with the above biocides had reduced invasiveness in Caco-2 cells, and altered growth kinetics. Resistance to disinfectants was observed only after exposure to gradually increasing concentrations of triclosan, accompanied with a 2000-fold increase in its MIC. Growth in OXC and TOP did not affect the MICs of antibiotics, but resulted in the appearance of a proportion of cells resistant to the MIC of acriflavine and triclosan for the wild-type. Randomly selected stable variants from all populations, except the one treated with TOP, over-expressed acrB. CONCLUSIONS: In vitro exposure to QACFG and triclosan selects for Salmonella Typhimurium cells with reduced susceptibility to several antibiotics. This is associated with overexpression of AcrAB efflux pump, but accompanied with reduced invasiveness.     

Incidence of Incisional Hernia Repair After Laparoscopic Compared to Open Resection of Colonic Cancer: A Nationwide Analysis of 17,717 Patients

Background

It remains unknown whether laparoscopic compared to open surgery translates into fewer incisional hernia repairs (IHR). The objectives of the current study were to compare the long-term incidence of IHR and the size of repaired hernias between patients subjected to laparoscopic or open resection of colonic cancer.

Methods

This was a nationwide cohort study comprised of patients undergoing resection for colonic cancer between January 2007 and March 2016 according to the Danish Colorectal Cancer Group database. Patients who subsequently underwent IHR were identified in the Danish Ventral Hernia Database, from which information about the priority of the hernia repair and the size of the fascial defect was retrieved.

Results

The study included 17,717 patients, of whom 482 (2.7%) underwent subsequent IHR during a median follow-up of 4.7 (interquartile range 2.8–6.9) years. There was no significant difference in the 5-year cumulative incidence of hernia repair after laparoscopic compared to open colonic resection (3.9%, CI 3.3–4.4% vs 4.1%, CI 3.5–4.6%). After adjustment for confounders, laparoscopic approach was associated with an increased rate of emergency IHR (HR 2.37, 95% CI 1.03–5.46, P = 0.042) as opposed to elective IHR (HR 0.91, 95% CI 0.73–1.14, P = 0.442). Laparoscopic surgery was significantly associated with a decreased fascial defect area compared to open surgery (mean difference −16.0 cm², 95% CI −29.4 to −2.5, P = 0.020).

Conclusions

There was no difference in the incidence of IHR after open compared to laparoscopic resection. Compared to the open approach, laparoscopic resection increased the rate of subsequent emergency IHR, suggesting that a more aggressive therapeutic approach may be warranted in this patient group upon diagnosis of an incisional hernia.

     

Surgical delivery of drug releasing poly(lactic-co-glycolic acid)/poly(ethylene glycol) paste with in vivo effects against glioblastoma

Introduction

The median survival of patients with glioblastoma multiforme (astrocytoma grade 4) remains less than 18 months despite radical surgery, radiotherapy and systemic chemotherapy. Surgical implantation of chemotherapy eluting wafers into the resection cavity has been shown to improve length of survival but the current licensed therapy has several drawbacks. This paper investigates in vivo efficacy of a novel drug eluting paste in glioblastoma.

Methods

Poly(lactic-co-glycolic acid)/poly(ethylene glycol) (PLGA/PEG) self-sintering paste was loaded with the chemotherapeutic agent etoposide and delivered surgically into partially resected tumours in a flank murine glioblastoma xenograft model.

Results

Surgical delivery of the paste was successful and practical, with no toxicity or surgical morbidity to the animals. The paste was retained in the tumour cavity, and preliminary results suggest a useful antitumour and antiangiogenic effect, particularly at higher doses. Bioluminescent imaging was not affected significantly by the presence of the paste in the tumour.

Conclusions

Chemotherapy loaded PLGA/PEG paste seems to be a promising technology capable of delivering active drugs into partially resected tumours. The preliminary results of this study suggest efficacy with no toxicity and will lead to larger scale efficacy studies in orthotopic glioblastoma models.     

Abdominal muscle function and incisional hernia: a systematic review

Purpose

Although ventral incisional hernia (VIH) repair in patients is often evaluated in terms of hernia recurrence rate and health-related quality of life, there is no clear consensus regarding optimal operative treatment based on these parameters. It was proposed that health-related quality of life depends largely on abdominal muscle function (AMF), and the present review thus evaluates to what extent AMF is influenced by VIH and surgical repair.

Methods

The PubMed and EMBASE databases were searched for articles following a systematic strategy for inclusion.

Results

A total of seven studies described AMF in relation to VIH. Five studies examined AMF using objective isokinetic dynamometers to determine muscle strength, and two studies examined AMF by clinical examination-based muscle tests.

Conclusion

Both equipment-related and functional muscle tests exist for use in patients with VIH, but very few studies have evaluated AMF in VIH. There are no randomized controlled studies to describe the impact of VIH repair on AMF, and no optimal surgical treatment in relation to AMF after VIH repair can be advocated for at this time.     

Chronic complaints after simple sutured repair for umbilical or epigastric hernias may be related to recurrence

Purpose

Umbilical and epigastric hernia repairs are minor, but are commonly conducted surgical procedures. Long-term results have only been sparsely investigated. Our objective was to investigate the risk of chronic complaints after a simple sutured repair for small umbilical and epigastric hernias.

Methods

A retrospective cohort study with a 5-year questionnaire and clinical follow-up was conducted. Patients undergoing primary elective, open non-mesh umbilical or epigastric sutured hernia repair were included. Patients completed a structured questionnaire regarding chronic complaints during work and leisure activities using a verbal rating scale. The primary outcome was chronic complaints.

Results

A total of 295 patients were included for analysis after a median of 5.0-year (range 2.8–8.0) follow-up period. Follow-up results were achieved from 262 of the included patients (90 % response rate). Up till 5.8 % of the patients reported moderate or severe pain and discomfort. Work and leisure activities were restricted in 8.5 and 10.0 % of patients, respectively. Patients with chronic complaints had a higher incidence of recurrence (clinical and reoperation), than patients with none or mild complaints (78.6 vs. 22.2 % (P?<?0.001)). The recurrence rate was significantly higher after a repair with absorbable suture (20.1 %) compared with non-absorbable suture repair (4.2 %) (P?<?0.001).

Conclusion

We found that chronic complaints after a simple sutured umbilical or epigastric repair was in the level of 5.5 % and could in part be explained by recurrence. Furthermore, absorbable suture should be omitted to reduce risk of recurrence.     

Proliferation and cytogenetic analysis of hairy cell leukemia upon stimulation via the CD40 antigen

Using the CD40 system, in vitro proliferation of hairy cell leukemia (HCL) was examined in 43 patients. In this culture system, cells were stimulated by interleukin-4 (IL-4) and anti-CD40 monoclonal antibodies (MoAbs) that were added in soluble form or were cross-linked via their Fc part using Fc gamma RII-transfected mouse fibroblast cells. Proliferation was induced and confirmed by 3H-thymidine incorporation in 14 cases and by the presence of metaphases in 42 cases. 3H-thymidine incorporation showed a heterogeneous pattern: cross-linking of anti- CD40 gave the highest proliferation in 8 cases; in 11 cases, stimulation with anti-CD40 MoAbs alone, without cross-linking also resulted in proliferation; the addition of IL-4 further enhanced 3H- thymidine incorporation in 5 cases, but suppressed this phenomenon in 5 other cases. The CD40 system proved to be very effective in obtaining cytogenetic data. With a success rate of 42 of 43 patients tested, we found clonal abnormalities in 8 cases (19%) and nonclonal abnormalities with involvement of one or two abnormal metaphases in another 7 cases. The chromosomes most frequently involved in the abnormal karyotypes, both structurally and numerically, were chromosomes 5, 7, and 14. By fluorescence-activated cell-sorting analysis of the cultured cells, and by immunophenotypic analysis of metaphase spreads, T-cell growth could be excluded and the HCL-lineage confirmed. Stimulation via the CD40 antigen is an excellent tool for growing hairy cell leukemia cells.     

The protein product of the proto-oncogene c-cbl forms a complex with phosphatidylinositol 3-kinase p85 and CD19 in anti-IgM-stimulated human B-lymphoma cells

Multiple signal transduction cascades, consisting of multiple interacting proteins, are activated following stimulation through most cell surface receptors, including the immunoglobulin receptor of B lymphocytes. In this report, we investigated the multimolecular complexes formed following anti-Ig stimulation of a human B-lymphoma cell line, resulting in activation of phosphatidylinositol 3-kinase (PI3K). PI3K is a lipid kinase that consists of an 85-kD regulatory subunit, bound to a 110-kD catalytic subunit. CD19 is a 95-kD B-cell surface marker that contains a consensus binding motif for PI3Kp85 in the cytoplasmic domain and recruits PI3K activity in activated B cells. The protein product of the c-cbl protooncogene is a 120-kD protein that is expressed in early B-lineage cells and in myeloid cells and is phosphorylated on tyrosine following receptor-mediated signaling in T and B lymphocytes. We demonstrate here that phosphorylated c-cbl complexes with CD19 and with PI3Kp85 via its C-terminal SH2 domain, and that both c-cbl and CD19 are associated with active PI3K in anti-Ig- stimulated cells. Although we cannot differentiate between a three- component, c-cbl/CD19/p85 complex and individual two-component complexes, these studies suggest that c-cbl may function as a docking protein, possibly linking distinct signal transduction pathways.     

Inhibition and complexation of activated protein C by two major inhibitors in plasma

To determine the major physiologic inhibitors of activated protein C (APC), plasma was incubated with APC or with Protac C and subjected to immunoblotting. APC:inhibitor complexes gave two major bands reacting with antiprotein C antibodies when immunoblotted on nondenaturing gels, and additional minor bands that varied between serum and plasma. Formation of one of the two major bands of APC:inhibitor complex, but not the other, was stimulated by heparin and only this band reacted with antibodies to the previously described APC inhibitor that is here designated PCI-1. Plasma immunodepleted of PCI-1 formed complexes with APC as visualized with antiprotein C but not anti-PCI-1 antibodies, and exhibited heparin-independent inhibition of APC activity, providing evidence for the existence of a second major physiologic APC inhibitor, PCI-2. Formation of APC:PCI-2 complexes in PCI-1-depleted plasma paralleled inhibition of APC amidolytic activity. PCI-2 was separated from PCI-1 and partially purified using column chromatography. PCI-2 formed inactive complexes of approximately 110,000 molecular weight (mol wt) with APC suggesting PCI-2 has an approximate mol wt of 50,000. Thus, inhibition of APC in plasma involves two major distinct 50,000 mol wt inhibitors, the heparin-dependent PCI-1 and the heparin- independent PCI-2.     

Gene transfer immunotherapy in rheumatoid arthritis: perspectives

INTRODUCTION: Tumor necrosis factor (TNF) blocking agents have changed the therapeutic approach in rheumatoid arthritis, but a true clinical remission remains rare. Gene therapy opens new perspectives in immunotherapy in rheumatoid arthritis. This review focuses on the research, data and clinical development in rheumatoid arthritis using this strategy. CURRENT KNOWLEDGE AND KEY POINTS: New therapeutical targets have been described besides the cytokine inhibitors: apoptosis inducers, angiogenesis inhibitors and metalloprotease inhibitors, cell activation and signalization have been used in experimental models to inhibit arthritis. Gene therapy makes it possible to better understand the physiopathology of rheumatoid arthritis and offers the opportunity to induce true remissions of experimental arthritis. FUTURE PROSPECTS AND PROJECTS: Biotechnology allows the development of new safer vectors which permit long-term expression. However, the difficulties to produce high titers and safe vectors limit the use of this strategy. The previous clinical data on gene therapy in rheumatoid arthritis are limited to feasibility studies. We believe that the efficiency of gene therapy will be obtained by combining two or more complementary targets.