Can hyperthermic intraperitoneal chemotherapy efficiency be improved by blocking the DNA repair factor COP9 signalosome?

PURPOSE: A frequently used chemotherapeutic agent in hyperthermic intraperitoneal chemotherapy (HIPEC) is mitomycin C (MMC) which induces DNA damage and apoptosis in tumor cells. In addition, MMC activates DNA damage response (DDR) leading to repair mechanisms counteracting the effect of chemotherapy. COP9 signalosome (CSN) positively influences the DDR pathway by its intrinsic deneddylating and associated kinase activities. In an in vitro HIPEC model, we studied the impact of curcumin, an inhibitor of CSN-associated kinases, and of the microRNA (miRNA) let-7a-1, an inhibitor of CSN subunit expression, on the MMC-induced apoptosis in human HT29 colon cancer cells. METHODS: Cells were incubated at 37 °C and indicated concentrations of MMC in a medium preheated to 42 °C as under HIPEC conditions for 1 or 4 h. HT29 cells were cotreated with 50 µM curcumin or transfected with let-7a-1 miRNA mimic. After incubation, cells were analyzed by Western blotting, densitometry, and caspase-3 ELISA. RESULTS: An increase of CSN subunits in response to MMC treatment was detected. Apoptosis was only measured after 4 h with 50 µM MMC. MMC-induced apoptosis was elevated by cotreatment with curcumin. Transfection of HT29 cells with let-7a-1 reduced the expression of tested CSN subunits associated with the accumulation of the pro-apoptotic factors p27 and p53. CONCLUSIONS: In response to MMC treatment, the CSN is elevated as a regulator of DDR retarding apoptosis in tumor cells. The therapeutic effect of HIPEC can be increased by inhibiting CSN-associated kinases via curcumin or by blocking CSN expression with let-7a-1 miRNA.

The COP9 signalosome, cullin 3 and Keap1 supercomplex regulates CHOP stability and adipogenesis.

Obesity is one of the most serious health problems of the 21(st) century. It is associated with highly increased risk of type 2 diabetes, high blood pressure, cardiovascular disease as well as several cancers. The expansion of the fat tissue needs the differentiation of preadipocytes to adipocytes, a process called adipogenesis. Dysfunction of adipogenesis is a hallmark of obesity and delineation of underlying mechanisms has high priority for identifying targets for pharmacological intervention. Here we investigate the impact of the COP9 signalosome (CSN), a regulator of cullin-RING ubiquitin ligases (CRLs), and of C/EBP homologous protein (CHOP) on the differentiation of LiSa-2 preadipocytes. CHOP induced by piceatannol or by permanent overexpression in LiSa-2 cells blocks adipocyte differentiation as characterized by inhibited fat droplet formation and vascular endothelial growth factor (VEGF) production. Knockdown of the CSN by permanent downregulation of CSN1 in LiSa-2 cells elevates CHOP and retards adipogenesis. The effect of the CSN knockdown on CHOP stability can be explained by the protection of the CRL component Keap1 by the CSN associated ubiquitin-specific protease 15 (USP15). Pulldowns and glycerol gradients reveal that CHOP interacts with a supercomplex consisting of the CSN, cullin 3 and Keap1. Transient knockdown of Keap1 increases CHOP steady state level and retards its degradation. We conclude that CHOP stability is controlled by a CSN-CRL3(Keap1) complex, which is crucial for adipogenesis. Our data show that CHOP is a distinguished target for pharmacological intervention of obesity.

Post-transcriptional fine-tuning of COP9 signalosome subunit biosynthesis is regulated by the c-Myc/Lin28B/let-7 pathway.

The COP9 signalosome (CSN) complex controls protein degradation via the ubiquitin (Ub) proteasome system (UPS) in eukaryotes. In mammalian cells, the multimeric CSN is composed of eight subunits (CSN1 - CSN8). It regulates cullin-RING Ub ligases (CRLs), which target essential regulatory proteins for ubiquitination and subsequent degradation. Thereby, the CSN cooperates with the UPS in a variety of essential cellular functions, including DNA repair, cell cycle and differentiation. Although functions of the CSN have been elucidated, mechanisms and regulatory principles of its de novo formation are completely unknown. Here, we show that there is a fundamental mechanism that allows a coordinated expression of all CSN subunits, a prerequisite for CSN assembly. CSN subunit mRNAs are targets of miRNAs of the let-7 family suppressing CSN subunit expression in human cells. Factors that reduce or block let-7 miRNAs induce the coordinated expression of CSN subunits. For instance, over-expression of CSN1 specifically traps let-7a-1 miRNA and elevates CSN subunit levels by two- to fourfold in a coordinated manner. CSN subunit expression is also increased by specific miRNA inhibitors or by interferon (IFN)-mediated induction of STAT1 and c-Myc reducing levels of let-7 miRNAs. Activation of STAT1 by IFNα or IFNγ induces c-Myc, which increases CSN subunit expression via the Lin28B/let-7 regulatory pathway. By contrast, a let-7a-1 mimic reduces CSN subunit expression. Our data show that let-7 miRNAs control the fine-tuning and coordinated expression of subunits for CSN de novo formation, presumably a general regulatory principle for other Zomes complexes as well.

Thoracoscopic thymectomy with the da Vinci robotic system for myasthenia gravis.

Complete thymectomy (Thx) is a crucial part of treatment for myasthenia gravis (MG) and thymoma. The discussion about the necessity of radical, complete Thx and reduced invasiveness has led to no less than 14 different surgical approaches for Thx. The latest development is robotic-assisted surgery. Though its impact on minimally invasive surgery is not yet clear, it seems to be most promising for surgery in remote, narrow anatomical regions like the mediastinum. One hundred six consecutive robotic-assisted thymectomies (rThx) with the da Vinci robotic surgical system were performed between January 2003 and April 2007 in a prospective single-center study. Postoperative morbidity was recorded according to the Myasthenia Gravis Foundation of America (MGFA) classification. With zero mortality, the overall postoperative morbidity rate was 2%. The cumulative complete stable remission rate of MG was > 40% for all patients, and there was no statistical difference as compared to non-thymomatous MG patients. The cumulative rate of minimal manifestations (MM0-MM3) according to the MGFA classification showed a postoperative improvement in quality of life for most of the patients. The da Vinci robotic system allowed for technical refinements of the well-defined operation technique of thoracoscopic Thx (tThx). From the technical point of view, rThx has advantages for mediastinal dissection. rThx had a shorter learning curve. There might be better outcome results for rThx in MG patients, as compared with nonrobotic tThx. Therefore, rThx is a promising technique for minimally invasive Thx.

Novel anti-angiogenic compounds for application in tumor therapy - COP9 signalosome-associated kinases as possible targets.

Preclinical studies revealed that curcumin, the yellow curry pigment, emodin, a compound derived from grapes, and taurolidine, derived from a biogenic amino acid, and some of their structural homologs possess anti-angiogenic and cancer chemopreventive properties. Whereas curcumin and emodin can act via inhibition of COP9 signalosome-associated kinases, taurolidine blocks protein biosynthesis.

Noninvasive monitoring of myocardial function after surgical and cytostatic therapy in a peritoneal metastasis rat model: assessment with tissue Doppler and non-Doppler 2D strain echocardiography.

OBJECTIVE: We sought to evaluate the impact of different antineoplastic treatment methods on systolic and diastolic myocardial function, and the feasibility estimation of regional deformation parameters with non-Doppler 2D echocardiography in rats. BACKGROUND: The optimal method for quantitative assessment of global and regional ventricular function in rats and the impact of complex oncological multimodal therapy on left- and right-ventricular function in rats remains unclear. METHODS: 90 rats after subperitoneal implantation of syngenetic colonic carcinoma cells underwent different onclogical treatment methods and were diveded into one control group and five treatment groups (with 15 rats in each group): group 1 = control group (without operation and without medication), group 2 = operation group without additional therapy, group 3 = combination of operation and photodynamic therapy, group 4 = operation in combination with hyperthermic intraoperative peritoneal chemotherapy with mitomycine, and group 5 = operation in combination with hyperthermic intraoperative peritoneal chemotherapy with gemcitabine, group 6 = operation in combination with taurolidin i.p. instillation. Echocardiographic examination with estimation of wall thickness, diameters, left ventricular fractional shortening, ejection fraction, early and late diastolic transmitral and myocardial velocities, radial and circumferential strain were performed 3-4 days after therapy. RESULTS: There was an increase of LVEDD and LVESD in all groups after the follow-up period (P = 0.0037). Other LV dimensions, FS and EF as well as diastolic mitral filling parameters measured by echocardiography were not significantly affected by the different treatments. Values for right ventricular dimensions and function remained unchanged, whereas circumferential 2D strain of the inferior wall was slightly, but significantly reduced under the treatment (-18.1 +/- 2.5 before and -16.2 +/- 2.9 % after treatment; P = 0.001) without differences between the single treatment groups. CONCLUSION: It is feasible to assess dimensions, global function, and regional contractility with echocardiography in rats under different oncological therapy. The deformation was decreased under overall treatment without influence by one specific therapy. Therefore, deformation assessment with non-Doppler 2D strain echocardiography is more sensitive than conventional echocardiography for assessing myocardial dysfunction in rats under oncological treatment.

The effect of computerized tailored brief advice on at-risk drinking in subcritically injured trauma patients.

BACKGROUND: One-third of injured patients treated in the emergency department (ED) have an alcohol use disorder (AUD). Few are screened and receive counseling because ED staff have little time for additional tasks. We hypothesized that computer technology can screen and provide an intervention that reduces at-risk drinking (British Medical Association criteria) in injured ED patients. METHODS: In all, 3,026 subcritically injured patients admitted to an ED were screened for an AUD using a laptop computer that administered the AUD Identification Test (AUDIT) and assessed motivation to reduce drinking. Patients with a positive AUDIT (n = 1,139) were randomized to an intervention (n = 563) or control (n = 576) condition. The computer generated a customized printout based on the patient's own alcohol use pattern, level of motivation, and personal factors, which was provided in the form of feedback and advice. RESULTS: Most patients (85%) used the computer with minimal assistance. At study entry, a similar proportion in each group met criteria for at-risk drinking (49.6% versus 46.8%, p = 0.355). At 6 months, 21.7% of intervention and 30.4% of control patients met criteria for at-risk drinking (p = 0.008). Intervention patients also had a 35.7% decrease in alcohol intake, compared with a 20.5% decrease in controls (p = 0.006). At 12 months, alcohol intake decreased by 22.8% in the intervention group versus 10.9% in controls (p = 0.023), but the proportion of at-risk drinkers did not significantly differ (37.3% versus 42.6%, p = 0.168). CONCLUSIONS: The computer-generated intervention was associated with a significant decrease in alcohol use and at-risk drinking. Research is needed to further evaluate and adapt information technology to provide preventive clinical services in the ED.

Hazardous alcohol consumption and sense of coherence in emergency department patients with minor trauma.

BACKGROUND: The concept of sense of coherence (SOC) measures the extent to which people are able to cope with stressful life events. Since excessive alcohol consumption may be, in part, the result of failed coping strategies, further investigations between hazardous alcohol consumption and SOC are necessary. METHODS: Survey in an Emergency Department in an inner city university hospital. Overall, 1,833 patients were screened for hazardous alcohol consumption, illicit drug use, smoking status, socioeconomic status and sense of coherence. RESULTS: Mean age of participants was 34+/-12 years and 62% were male. Overall, 23% of patients showed a pattern of hazardous alcohol consumption, 23% had abused illicit drugs and 46% were smokers. Mean SOC score was 48.9+/-8.6 points, with no difference between genders. Lower SOC-quartiles were associated with significantly higher prevalence of hazardous alcohol consumption as well as illicit drug abuse and smoking. Lower SOC-quartiles were associated with significantly lower values on socioeconomic variables (e.g. lower income, less education). The negative association between SOC and alcohol consumption was independent of age, gender, smoking, illicit drug use and all socioeconomic variables. CONCLUSION: SOC and hazardous alcohol consumption were significantly associated. Our data support Antonovsky's original concept of increased alcohol consumption as a result of failed coping strategies.

Transverse versus midline incision for upper abdominal surgery.

PURPOSE: Transverse and midline abdominal incisions are both commonly used for laparotomy to perform surgery on the pancreas and stomach, but comparative data are limited, especially from prospective randomized trials. METHODS: During a predefined 2-year recruitment period, 94 patients undergoing an elective major laparotomy for disorders of the pancreas or stomach were enrolled in this study. The outcome measures were pulmonary function, incisional pain, and wound characteristics. RESULTS: The operation groups were equally divided according to the type of incision used. The patients who underwent transverse incision laparotomy had significantly better postoperative pulmonary function and significantly less postoperative incisional pain than those who underwent midline incision laparotomy (P < 0.05), but there were no differences in morbidity and the incidence of wound complications. CONCLUSION: Performing a transverse incision for surgery on the pancreas or stomach results in better postoperative pulmonary function and less incisional pain than a midline incision, without affecting postoperative morbidity.

Gender differences in the performance of a computerized version of the alcohol use disorders identification test in subcritically injured patients who are admitted to the emergency department.

OBJECTIVE: The Alcohol Use Disorder Identification Test (AUDIT) has been recommended as a screening tool to detect patients who are appropriate candidates for brief, preventive alcohol interventions. Lower AUDIT cutoff scores have been proposed for women; however, the appropriate value remains unknown. The primary purpose of this study was to determine the optimal AUDIT cutpoint for detecting alcohol problems in subcritically injured male and female patients who are treated in the emergency department (ED). An additional purpose of the study was to determine whether computerized screening for alcohol problems is feasible in this setting. METHODS: The study was performed in the ED of a large, urban university teaching hospital. During an 8-month period, 1205 male and 722 female injured patients were screened using an interactive computerized lifestyle assessment that included the AUDIT as an embedded component. World Health Organization criteria were used to define alcohol dependence and harmful drinking. World Health Organization criteria for excessive consumption were used to define high-risk drinking. The ability of the AUDIT to classify appropriately male and female patients as having one of these three conditions was the primary outcome measure. RESULTS: Criteria for any alcohol use disorder were present in 17.5% of men and 6.8% of women. The overall accuracy of the AUDIT was good to excellent. At a specificity >0.80, sensitivity was 0.75 for men using a cutoff of 8 points and 0.84 for women using a cutoff of 5 points. Eighty-five percent of patients completed computerized screening without the need for additional help. CONCLUSIONS: Different AUDIT scoring thresholds for men and women are required to achieve comparable sensitivity and specificity when using the AUDIT to screen injured patients in the ED. Computerized AUDIT administration is feasible and may help to overcome time limitations that may compromise screening in this busy clinical environment.

Renal replacement therapy with high-cutoff hemofilters: Impact of convection and diffusion on cytokine clearances and protein status.

BACKGROUND: High-cutoff hemofilters are characterized by an increased effective pore size designed to facilitate the elimination of inflammatory mediators in sepsis. This study compares diffusive versus convective high-cutoff renal replacement therapy (RRT) in terms of cytokine clearance rates and effects on plasma protein levels. METHODS: Twenty-four patients with sepsis-induced acute renal failure were studied. A polyflux hemofilter with a cutoff point of approximately 60 kd was used for RRT. Patients were randomly allocated to either continuous venovenous hemofiltration (CVVH) with an ultrafiltration rate of 1 L/h (group 1) or 2.5 L/h (group 2) or continuous venovenous hemodialysis (CVVHD) with a dialysate flow rate of 1 L/h (group 3) or 2.5 L/h (group 4). Interleukin-1 (IL-1) receptor antagonist (IL-1ra), IL-1beta, IL-6, tumor necrosis factor-alpha (TNF-alpha), and plasma proteins were measured daily. RESULTS: CVVH achieved significantly greater IL-1ra clearance compared with CVVHD (P = 0.0003). No difference was found for IL-6 (P = 0.935). Increasing ultrafiltration volume or dialysate flow led to a highly significant increase in IL-1ra and IL-6 clearance rates (P < 0.00001). Peak clearances were 46 mL/min for IL-1ra and 51 mL/min for IL-6. TNF-alpha clearance was poor for both RRT modalities. A significant decline in plasma IL-1ra and IL-6 clearance was observed in patients with high baseline levels. Protein and albumin losses were greatest during the 2.5-L/h hemofiltration mode. CONCLUSION: High-cutoff RRT is a novel strategy to clear cytokines more effectively. Convection has an advantage over diffusion in the clearance capacity of IL-1ra, but is associated with greater plasma protein losses.

High permeability haemofiltration improves peripheral blood mononuclear cell proliferation in septic patients with acute renal failure.

BACKGROUND: Continuous veno-venous haemofiltration (HF) with high permeability (HP) haemofilters is a novel approach in the adjuvant therapy of septic patients. HP haemofilters are characterized by an increased pore size which facilitates the filtration of inflammatory mediators. The present study examines whether HP-HF has an impact on peripheral blood mononuclear cell (PBMC) proliferation and whether ultrafiltrate can alter PBMC function in isolates from healthy volunteers. METHODS: Twenty-eight septic patients with acute renal failure were randomly allocated to either HP-HF or conventional HF (C-HF). HP-HF was performed with a newly developed high-flux polyamide membrane (P2SH) with a nominal cut-off point of 60 kDa. For C-HF, a high-flux polyamide haemofilter (Polyflux 11S; cut-off, 30 kDa) was used. RESULTS: Septic patients demonstrated a significantly reduced proliferation of anti-CD3-stimulated PBMCs compared to healthy controls (P = 0.016). Initiating HF led to a restoration of the PBMC proliferation in HP-HF but not in C-HF. Exposing PBMCs isolated from healthy donors to ultrafiltrates from patients with sepsis demonstrated a significant suppressive effect of HP ultrafiltrates on the anti-CD3-stimulated PBMC proliferation (P = 0.011). Ultrafiltrate from patients with sepsis who received C-HF had no impact on PBMC proliferation. CONCLUSION: HP-HF restores PBMC proliferation in septic patients probably by eliminating immunomodulatory mediators. HP-HF may represent a new renal replacement therapy able to modulate PBMC function in sepsis.

Cochlear implants: some likely next steps.

The history of cochlear implants is marked by large improvements in performance, especially over the past two decades and especially due to the development of ever-better processing strategies. Although the progress to date has been substantial, present devices still do not restore normal speech reception, even for top performers and particularly for listening to speech in competition with noise or other talkers. In addition, a wide range of outcomes persists, with some patients receiving little benefit using the same devices that support high levels of speech reception for others. The purpose of this review is to describe some likely possibilities for further improvement, including (a) combined electric and acoustic stimulation of the auditory system for patients with significant residual hearing, (b) use of bilateral implants, (c) a closer replication with implants of the processing steps in the normal cochlea, and (d) applications of knowledge about factors that are correlated with outcomes to help patients presently at the low end of the performance scale.

Isolated amyloid tumor in the mediastinum: report of a case.

Primary amyloidosis isolated in the mediastinum is rarely encountered in thoracic surgery and few such cases have been reported. We present a case of primary isolated hilar amyloidosis of the mediastinum to illustrate the difficulties in differentiating this disorder preoperatively from central bronchial carcinoma, carcinoid tumor, and mediastinal lymphoma. Usually, a definitive diagnosis can only be made by open biopsy during thoracoscopy or thoracotomy. In conclusion, amyloidosis should be considered in the differential diagnosis of patients when calcifications are found, bearing in mind that radiologic findings are inconclusive and transbronchial biopsy can be negative.

Thoracoscopy before Jacobaeus.

In 1910 Jacobaeus described a procedure to which he referred as "Thorakoskopie." As a consequence, he is credited with having been the first to undertake an endoscopic exploration of the thorax. However, a published report by Gordon demonstrates that thoracoscopy was performed about 50 years earlier. Additionally in French, at least, the term "thoracoscopie" was well known long before Jacobaeus, although perhaps with a different meaning.

Radical thoracoscopic lobectomy with lymphadenectomy in a cadaver model.

OBJECTIVE: Because the standard thoracoscopic lobectomy in bronchial carcinoma is often criticized for assumed incomplete lymph-node dissection and oncologic radicality, thoracoscopic lymphadenectomy (TL) was investigated as one step of a scientific investigation for developing a method of complete thoracoscopic resection of bronchial carcinoma. DESIGN: A cadaver model (n = 13) was used to investigate the technique of thoracoscopic radical hilar lobectomy and mediastinal lymphadenectomy. INTERVENTION: TL followed by a large anterolateral exploratory thoracotomy to evaluate the safety and radicality of TL. RESULTS: The mean (and standard deviation) number of lymph nodes resected was 15.6 (4.3). On follow-up exploration, no residual tissue was found at the hilar stump or residual lymph nodes. No other intrathoracic lesions were found. CONCLUSIONS: TL with radical hilar and mediastinal lymphadenectomy by the described tehcnique can be accomplished according to current oncologic regulations.

Quality of life after gastrectomy: Longmire's reconstruction alone compared with additional pouch reconstruction.

The optimal reconstruction protocol after total gastrectomy is still a matter of debate. Pouch reconstructions are developed to create a larger reservoir for food, to provide a barrier against intestinoesophageal reflux, and to lengthen the food transit time. Preservation of the duodenal passage should result in better physiologic regulation of the ingested food. Controlled randomized clinical studies must be conducted to assess the quality of life after gastrectomy and various types of reconstruction. In the present trial, which compared Longmire's reconstruction without a pouch and Longmire's reconstruction with a pouch of varying sizes, we evaluated the quality of life for 41 patients during the first postoperative year. The quality of life was examined by an EORTC questionnaire and an organ-specific module. There were no statistically proven benefits for pouch reconstruction in comparison with Longmire's reconstruction alone. Some benefits are shown for the large pouch but it was only a trend. This is especially so with regard to diarrhea and food consumption. A definitive answer to the question about the value of a pouch reconstruction after gastrectomy has not yet been attained. It is possible that there will be significant differences between reconstruction groups during the long-term follow-up.

Thalidomide given intraperitoneally reduces the number of postoperative adhesions after large bowel resection in rabbits.

OBJECTIVE: To investigate the effect of thalidomide given intraperitoneally on the formation of adhesions after colonic resection in rabbits. DESIGN: Controlled, randomised prospective study. SETTING: University hospital, Germany. ANIMALS: 40 female New Zealand White rabbits. INTERVENTIONS: After an end-to-end colonic anastomosis the animals were given thalidomide 200 mg/kg in 1% carboxymethylcellulose intraperitoneally or carboxymethylcellulose alone (n = 20 in each group). OUTCOME MEASURES: The adhesion score according to Tyrell on day 3 (n = 20) and day 7 (n = 20) postoperatively, weight, behaviour, and white cell count (WCC). RESULTS: There was no difference in behaviour or weight. On the third postoperative day WCCs and on the seventh postoperative day WCCs and adhesion scores, were lower in the thalidomide group (p < 0.01). CONCLUSION: The number of postoperative adhesions was reduced in the group given thalidomide intraperitoneally. Our results suggest that thalidomide may be helpful in the prevention of postoperative adhesions.