NXF1 and CRM1 nuclear export pathways orchestrate nuclear export, translation and packaging of murine leukaemia retrovirus unspliced RNA.

Cellular mRNAs are exported from the nucleus as fully spliced RNAs. Proofreading mechanisms eliminate unprocessed and irregular pre-mRNAs to control the quality of gene expression. Retroviruses need to export partially spliced and unspliced full-length RNAs to the cytoplasm where they serve as templates for protein synthesis and/or as encapsidated RNA in progeny viruses. Genetically complex retroviruses such as HIV-1 use Rev-equivalent proteins to export intron-retaining RNA from the nucleus using the cellular CRM1-driven nuclear export machinery. By contrast, genetically simpler retroviruses such as murine leukaemia virus (MLV) recruit the NXF1 RNA export machinery. In this study, we reveal for the first time that MLV hijacks both NXF1 and CRM1-dependent pathways to achieve optimal replication capacity. The CRM1-pathway marks the MLV full-length RNA (FL RNA) for packaging, while NXF1-driven nuclear export is coupled to translation. Thus, the cytoplasmic function of the viral RNA is determined early in the nucleus. Depending on the nature of ribonucleoprotein complex formed on FL RNA cargo in the nucleus, the FL RNA will be addressed to the translation machinery sites or to the virus-assembly sites at the plasma membrane.

Do microRNAs regulate bone marrow stem cell niche physiology?

The adult bone marrow, situated within the bone cavity, comprises three distinct stem cell populations: hematopoietic stem cells (HSCs), mesenchymal stromal/stem cells (MSCs) and endothelial progenitor/stem cells (EPCs). HSCs are a well-characterized population of self-renewing cells that give rise to all blood cells. The definition of MSCs is more complex due to the limited understanding of MSC properties. In general, MSCs are considered multipotent stromal cells that are able to differentiate into various cell types, including osteoblasts, chondrocytes and adipocytes. Compared to HSCs and MSCs, EPCs are a newly discovered population of stem/progenitor cells with the capacity to differentiate into endothelial cells, the cells forming the inner lining of a blood vessel. Although functionally different, HSCs, MSCs and EPCs, like stem cells in general, share the ability to self-renew and differentiate into one or more cell types. The homeostasis inside the bone marrow and within the entire body is sustained by an intricate network of growth factors and transcription factors that orchestrate the proliferation and differentiation of these multipotent stem/progenitor cells. Increasing evidence indicates that microRNAs (miRNAs), small non-coding RNAs, are among the key players of this concert. This review summarizes the current insights into miRNA-mediated regulation of bone marrow stem/progenitor cell maintenance and differentiation. Furthermore, the potential contribution of miRNAs in bone marrow stem cell niches is discussed.

Use of self-expandable metal stents for the treatment of esophageal perforations and anastomotic leaks.

BACKGROUND: Esophageal perforations and extensive anastomotic leaks after esophageal resection or gastrectomy are surgical emergencies with high mortality rates. In recent years, the use of self-expanding metallic stents (SEMS) has emerged as a promising treatment alternative for bridging and sealing the damage. This study aimed to evaluate the role of covered SEMS for the management of esophageal perforations and anastomotic leaks. METHODS: All esophageal stent placement procedures (174 procedures for 157 patients) at the authors' unit between January 1999 and April 2008 were assessed by a retrospective chart review. Of the 157 patients, 10 (6.4%) were treated with SEMS for sealing of an iatrogenic esophageal perforation (n = 4), a spontaneous esophageal rupture in Boerhaave's syndrome (n = 4), or an anastomotic leakage (n = 2). RESULTS: The median time from perforation or anastomotic leak to stent insertion was 13 days (range, 2 h to 48 days). The esophageal leak was totally sealed for 8 (80%) of 10 patients. The overall mortality rate was 50% (n = 5), and three (30%) of the five deaths were related to the perforation (n = 2) or leakage (n = 1). In both of the perforation cases, the diagnosis and treatment were substantially delayed. One patient with an anastomotic leak after gastrectomy died of the complication despite successful operative and SEMS treatment. Two of the deaths were unrelated to the perforation. In both cases, the cause of death was a disseminated malignant disease. CONCLUSIONS: Traumatic perforations and anastomotic leaks can be treated effectively with covered SEMS together with adequate drainage of the thoracic cavity even in cases of severely ill patients with inveterate esophageal perforations and leaks.

Job strain as a predictor of disability pension: the Finnish Public Sector Study.

OBJECTIVE: To examine whether high job strain (a combination of high job demands and low job control) is a risk factor for disability pension. SETTING: Ten municipalities and 21 hospitals in Finland. DESIGN AND PARTICIPANTS: A prospective cohort study of 20 386 female and 4 764 male Finnish public sector employees aged 19-50 using data from two surveys (baseline in 2000-2 and follow-up in 2005) and employers' registers. In addition to self-reported job strain, we computed work unit-aggregated job strain for each participant (the average of scores of all workers of participant's work unit except the participant him/herself). MAIN RESULTS: 93 employees (0.4%) retired because of disability during the follow-up. In multilevel logistic regression analysis adjusted for demographic characteristics and health risk behaviour, odds for disability pension was 2.60 (95% CI 1.26 to 5.34) times higher for employees with high self-assessed job strain than for those with low self-assessed job strain at baseline. The corresponding OR for passive job versus low job strain was 2.82 (95% CI 1.34 to 5.96). Analysis of work unit-aggregated scores replicated the association for high job strain, OR 2.25 (95% CI 1.17 to 4.35), but not that for passive job. The association between work unit job strain and disability pension remained significant after further adjustment for prevalent diseases, psychological distress and perceived health status. CONCLUSIONS: Job strain is associated with risk of subsequent disability pension. If causal, this association suggests that organisational interventions to reduce job strain may also reduce early exit from work.

Severe and fatal complications after ERCP: analysis of 2555 procedures in a single experienced center.

BACKGROUND AND STUDY AIMS: The majority of recent large series on endoscopic retrograde cholangiopancreatography (ERCP) complications have been multicenter studies reflecting varying degrees of experience and ERCP volume; major ERCP complications are associated with low case volume. The aim of this study was to report and analyze the frequency of severe and fatal complications associated with ERCP at a single specialized surgical high-volume referral center (Turku University Central Hospital). METHODS: All scheduled ERCP procedures (n = 2788) at our unit between January 1997 and December 2005 were included and the procedure-related severe and fatal complications were assessed by retrospective chart review. Complications were classified as severe or fatal according to standardized guidelines. RESULTS: The number of ERCP procedures performed was 2555, of which 71% were therapeutic and 29% were diagnostic. Seventeen (0.8%) severe complications were identified in 16 patients, of whom 15 underwent a therapeutic endoscopic procedure. Of the 17 severe complications, perforation constituted five cases (0.2%), pancreatitis occurred in five patients (0.2%), bleeding in five cases (0.2%), and two patients suffered from purulent cholangitis (0.1%). Procedure-related mortality was 0.08% (n = 3). CONCLUSIONS: In our study the rate of severe or fatal complications of ERCP is low in experienced hands at a high-volume center, comparing favorably to corresponding complication rates of multicenter series, which further supports the importance of centralizing ERCP procedures in high-volume advanced centers.

Surgeons' experience with laparoscopic fundoplication after the early personal experience: does it have an impact on the outcome?

BACKGROUND: The adverse outcomes of laparoscopic fundoplication are more likely during the initial 20 cases performed by each individual surgeon. This study aimed to evaluate the impact of substantial surgical experience versus experience beyond the learning curve on the early and late objective and subjective results. METHODS: The patients were divided into two groups according to the surgeon. In group 1 (n = 230), all the patients underwent surgery by a surgeon with substantial experience in laparoscopic fundoplication. In group 2 (n = 118), the patients were treated by a total of seven surgeons whose personal experience exceeded the individual learning curve, but was distinctively less than that of the group 1 surgeon. RESULTS: The conversion rate was 2.2% in group 1 and 4.4% in group 2. The median operating time was 65 min in group 1 and 70 min in group 2 (p = 0.0020). The occurrence of immediate complications was 3.5% in group 1 and 7.6% in group 2 (p = 0.0892). At 6 months after surgery, 7.4% of the patients in group 1 and 16.1% of the patients in group 2 reported that dysphagia disturbed their daily lives (p = 0.0115). The late subjective results, including postoperative symptoms and evaluation of the surgical result, were similar in the two groups. CONCLUSIONS: Substantial experience with the procedure is associated with a shorter operating time and somewhat fewer complications, conversions, and early dysphagia episodes. This supports the provision of expert supervision even after the initial learning phase of 20 individual procedures. The patients' long-term subjective symptomatic outcome was similar in the two groups. Substantial experience does not provide better late results than surgical experience beyond the learning curve.

Duodenal diazepam-binding protein expression and plasma cholecystokinin after alcoholic pancreatitis.

OBJECTIVE: After the first acute alcohol-induced pancreatitis (AAIP) episode 46 % of patients will have a recurrent attack, but the pathophysiology is unclear. The hyperstimulation of the pancreas with cholecystokinin (CCK) induces acute pancreatitis. Alcohol induces temporary stimulation of the pancreas and CCK could be a mediator. CCK is regulated by releasing peptides - diazepam-binding protein (DBI) being a possible candidate. The aim of this study was to investigate the possible association between CCK plasma levels and DBI expression in patients with AAIP or its recurrence. MATERIAL AND METHODS: The study comprised 44 subjects (mean age 42 years): A) Patients with a first episode of AAIP (n = 9); B) patients with three or more episodes of AAIP (n = 11); C) patients with a heavy alcohol consumption, with no detected AAIP (n = 11) and D) healthy controls (n = 13). CCK levels were measured by radioimmunoassay (RIA). Duodenal biopsies were analyzed for DBI mRNA and histology. RESULTS: There was no significant difference in CCK plasma levels, DBI expression or CCK/DBI ratio between the groups. CONCLUSIONS: There were no changes in fasting CCK plasma levels or DBI expression. This may suggest that they do not play a major role as risk factors for alcohol-induced pancreatitis.

Needle-knife assisted ERCP.

BACKGROUND: During endoscopic retrograde cholangiopancreatography (ERCP), incising through the wall of the major papilla with an electrocautery needle-knife is a method for achieving access into the bile duct. This procedure, often referred to as a "precut," may be used when cannulation attempts via the orifice of the papilla are unsuccessful. Potential complications include hemorrhage, duodenal perforation, and acute pancreatitis. METHODS: The 172 patients who underwent an attempt of a needle-knife assisted ERCP during the years 1997-2003 at our institution were retrospectively evaluated. RESULTS: A selective bile duct cannulation was achieved after needle-knife incision in 148 out of 172 patients (86%) at the primary session. In 10 additional patients (6%), a repeated procedure proved successful for cannulation. In the remaining 14 patients (8%), the biliary cannulation failed and was not attempted again. Complications after needle-knife assisted ERCP occurred as follows: three patients (2%) presented with late bleeding after the ERCP and three patients (2%) developed acute pancreatitis. None of the patients required operative treatment for complications. There was no mortality. CONCLUSION: The use of the needle-knife markedly improves the success rate of selective biliary cannulation in ERCP without increasing the rate of complications.

Serum matrix metalloproteinase-9 is elevated in men with a history of myocardial infarction.

Elevated serum inflammatory markers have been reported in coronary heart disease. Levels of serum matrix metalloproteinase-9 (MMP-9), C-reactive protein (CRP), C3-complement (C3) and autoantibodies against oxidized low-density lipoprotein (oxLDL) in 120 male subjects with a history of myocardial infarction (MI) were compared with those in 250 age-matched controls, both groups from a large cross-sectional population survey, the FINRISK study. The concentrations of serum MMP-9 and autoantibodies against oxLDL were measured by enzyme-linked immunosorbent assay, CRP and C3 by immunonephelometry. MMP-9, CRP and C3 concentrations were higher in the subjects with a history of MI than in the controls (p=0.037, p=0.004, and p=0.006, respectively). There was no difference between the groups in serum levels of autoantibodies against oxLDL. In other background characteristics, men in the MI group had higher body mass index (BMI) and serum triglyceride values and lower serum HDL cholesterol values compared to controls (p=0.009, p=0.001, and p<0.001, respectively). When analyzed by stepwise multiple logistic regression using BMI, HDL cholesterol, triglycerides, CRP, C3 and MMP-9 as independent variables, the significant predictors for MI were HDL cholesterol (p=0.002) and MMP-9 (p=0.015). These results suggest that increased serum MMP-9 may reflect inflammatory pathologic processes that are related to progression of atherosclerosis.

Circulating oxidized low-density lipoprotein and common carotid artery intima-media thickness in a random sample of middle-aged men.

Circulating oxidized low-density lipoprotein (oxLDL) has been suggested to play an important role in atherosclerosis development. According to previous observations, oxLDL correlates with clinically manifest coronary and carotid artery disease. We investigated the association between the oxLDL concentration measured directly in plasma and common carotid artery intima-media thickness (IMT) in a population-based, case-control study in middle-aged men from Southern Finland. oxLDL was determined in 214 men by a commercially available sandwich ELISA test (Mercodia). Carotid artery IMT was measured at 12 standardized segments by B-mode ultrasonography (at the near and far wall of the left and right common carotid arteries, bifurcations and internal carotid arteries), and the overall mean maximum IMT (MMaxIMT) was calculated. The MMaxIMT of the carotid arteries was significantly associated with circulating oxLDL (r(s) = 0.16, p = 0.018). In a stepwise multiple regression model with MMaxIMT as dependent variable and systolic blood pressure, smoking, oxLDL, HDL cholesterol and apolipoprotein B as covariates, systolic blood pressure (beta = 0.22, p < 0.001), oxLDL (beta = 0.15, p = 0.022) and smoking (beta = 0.17, p = 0.014) showed an independent association with IMT (R(2) = 0.10, p < 0.001). Our results show that oxLDL measured directly from plasma is independently associated with subclinical carotid artery atherosclerosis in middle-aged men.

In vitro and in vivo interactions between the hepatitis B virus protein P22 and the cellular protein gC1qR.

gC1qR, a mitochondrial matrix protein, was identified as the main cellular partner of the hepatitis B virus P22 protein. We demonstrated by immunofluorescence studies that some P22 molecules were colocalized with the endogenous gC1qR in both the cytoplasm and the nucleus but never in the mitochondria. We also showed that the last 34 amino acids of P22 were involved in the association with gC1qR.

Anti-inflammatory cytokine response and the development of multiple organ failure in severe sepsis.

BACKGROUND: The production of proinflammatory cytokines activates the systemic inflammatory response in sepsis. Patients also develop a compensatory anti-inflammatory reaction, which may have an important down-regulatory effect on the overactive inflammation. However, the role of this anti-inflammatory response in sepsis is not completely clarified. In this prospective study, we investigated the relationship between the pro- and anti-inflammatory cytokine profiles in severe sepsis and their role in the development of multiple organ failure (MOF). METHODS: Thirty-eight patients meeting the criteria for severe sepsis were studied. MOF was defined as a maximum SOFA score of 10 or higher. Serial measurements of the proinflammatory IL-6 and IL-1beta and the anti-inflammatory IL-10 and IL-1ra were used. The cytokine samples were taken at the onset of sepsis and on the third and fifth day during the ICU period. RESULTS: The initial IL-10 and IL-1ra responses were identical in patients with or without MOF. The anti-inflammatory cytokine levels remained elevated in the MOF patients, whereas in patients without MOF the levels declined. The IL-6/IL-10 ratio was significantly higher in the MOF patients on days 1 and 3 compared with patients without MOF. CONCLUSIONS: We could not demonstrate overproduction of anti-inflammatory IL-10 in MOF patients. On the contrary, the high IL-6/IL-10 ratio indicates that IL-10 deficiency may contribute to the development of MOF in severe sepsis.

Immunoglobulin G3 and immunoglobulin M isotype plasma levels are influenced by interleukin-1alpha genotype.

The immunoglobulin (Ig) plasma levels are known to be, at least partially, genetically regulated, but all the genes involved are not known. Interleukin-1 (IL-1) is a potent proinflammatory cytokine able to serve as an adjuvant for immune responses. IL-1alpha gene is polymorphic, and at least one of the polymorphisms has been identified in the 5' regulatory region of the promoter, a biallelic base exchange (C-->T) at position -889. We set out to study whether the IL-1alpha genotype might contribute to the genetic component seen in the steady-state antibody levels of healthy individuals. Four hundred healthy blood donors (218 males and 182 females) were genotyped, and the plasma levels of IgM, IgG as well as IgG subclasses were measured. An association was found between IgG3 plasma levels and the IL-1alpha genotype; the 1.1 homozygotes had increased IgG3 levels compared with the 1.2 heterozygotes (P < 0.001 in males and P = 0.04 in females, Mann-Whitney U-test). A similar significant association was also found between IgM plasma levels and the IL-1alpha genotype in males, but it was no longer present in females; the 1.1 homozygotes had higher IgM levels than the 2.2 homozygotes (P = 0.03, Mann-Whitney U-test). The data suggest that IL-1alpha-mediated signals are critical for IgG3 and IgM responses, which are induced by thymus-independent antigens and are important in activating complement.

Mutations in a new gene encoding a protein of the hair bundle cause non-syndromic deafness at the DFNB16 locus.

Hearing impairment affects about 1 in 1,000 children at birth. Approximately 70 loci implicated in non-syndromic forms of deafness have been reported in humans and 24 causative genes have been identified (see also http://www.uia.ac.be/dnalab/hhh). We report a mouse transcript, isolated by a candidate deafness gene approach, that is expressed almost exclusively in the inner ear. Genomic analysis shows that the human ortholog STRC (so called owing to the name we have given its protein-stereocilin), which is located on chromosome 15q15, contains 29 exons encompassing approximately 19 kb. STRC is tandemly duplicated, with the coding sequence of the second copy interrupted by a stop codon in exon 20. We have identified two frameshift mutations and a large deletion in the copy containing 29 coding exons in two families affected by autosomal recessive non-syndromal sensorineural deafness linked to the DFNB16 locus. Stereocilin is made up of 1,809 amino acids, and contains a putative signal petide and several hydrophobic segments. Using immunohistolabeling, we demonstrate that, in the mouse inner ear, stereocilin is expressed only in the sensory hair cells and is associated with the stereocilia, the stiff microvilli forming the structure for mechanoreception of sound stimulation.

Inflammatory cytokines and soluble receptors after coronary artery bypass grafting.

Much interest has been focused on the overexpression of proinflammatory cytokines, but studies on their soluble receptors are rare. For a comprehensive picture of cytokine activation in cardiac surgery, a combination of cytokines and the corresponding soluble receptor concentration should be determined. Blood samples were collected from the radial artery and coronary sinus perioperatively in ten patients undergoing coronary artery bypass grafting with cardiopulmonary bypass. TNF-alpha, IL-6, sTNFRI, sTNFRII, and sIL-6R levels in the plasma were determined. Systemic TNFRI, TNFRII and IL-6 increased significantly after reperfusion to the myocardium, while perioperative systemic sIL-6r levels were similar. Arterial and sinus levels of TNFRI, TNFRII and sIL-6r were similar before cardiopulmonary bypass. Five minutes after reperfusion to the myocardium, higher sinus TNFRI and TNFRII and lower sinus sIL-6R levels were observed as compared to the arterial levels. The myocardium release of sTNFRI (r=0.57, P=0.089) and sTNFRII (r=0.64, P=0.047) positively correlated with the change of cardiac index after cardiopulmonary bypass. Myocardium releases sTNFRI and sTNFRII after ischaemic-reperfusion injury, and this may be of benefit to cardiac performance. sIL-6R is constantly being produced in areas other than the myocardium, while sIL-6R levels are reduced by consumption in the myocardium after ischaemic-reperfusion injury.

Cardioprotective effect of adenosine pretreatment in coronary artery bypass grafting.

OBJECTIVE: There are several reports of the use of adenosine as a cardioprotective agent during cardiac surgery. Adenosine treatment might affect neutrophils and inflammatory mediators. The present prospective randomized study was designed to investigate the effect of adenosine pretreatment on myocardial recovery and inflammatory response in patients undergoing elective coronary artery bypass surgery. DESIGN: A prospective, randomized, controlled study. SETTING: Operative unit and ICU in a university hospital in Finland. PATIENTS: Thirty male patients undergoing primary, elective coronary revascularization. INTERVENTIONS: Patients in the adenosine group received a 7-min infusion of adenosine (total, 650 microg/kg) before the initiation of cardiopulmonary bypass. MEASUREMENTS: Postoperative creatine kinase (CK)-MB release and hemodynamics were recorded. Perioperative leukocyte and cytokine release were measured. RESULTS: Adenosine pretreatment resulted in less CK-MB release and an improved postbypass cardiac index. Similar leukocyte counts and cytokine responses were seen in both groups perioperatively. Neutrophil counts were similar between the groups before and after myocardial ischemia when measured simultaneously in arterial and coronary sinus blood. CONCLUSIONS: The present results support the hypothesis that adenosine pretreatment is cardioprotective in humans, but the present dose failed to regulate the inflammatory responses after coronary artery bypass grafting.

Serum adhesion molecules and interleukin-2 receptor as markers of tumour load and prognosis in advanced cutaneous melanoma.

Cell adhesion molecules are cell surface glycoproteins that may act as mediators in the metastatic process. Soluble interleukin-2 receptor (sIL-2R) is an immunological marker that may also serve as an indicator of tumour progression. Normal and neoplastic cells are capable of releasing these molecules into circulation. We evaluated the association between pretreatment serum levels of soluble intercellular adhesion molecule 1 (sICAM-1), vascular cell adhesion molecule 1 (sVCAM-1) and sIL-2R and metastases and survival in 50 patients with advanced melanoma. The patients with liver and/or bone metastases had significantly higher sICAM-1 levels than those with soft tissue and/or lung involvement (P=0.002). In addition, there was a trend towards higher sIL-2R levels in patients with more metastatic sites (P=0.07). In univariate analysis, the number of metastatic sites (P=0.0001, odds ratio (OR) 3.0, 95% confidence interval (CI): 1.7-5.3), the metastatic site (P=0.01, OR 2.3, 95% CI: 1.2-4.4) and the levels of sICAM-1 (P=0.011, OR 2.5, 95% CI: 1.2-5.0), sVCAM-1 (P=0.036, OR 2.1, 95% CI: 1.0-4.3) and sIL-2R (P=0.0016, OR 3.0, 95% CI: 1.5-6.0) were found to be statistically significant prognostic factors for survival. In multivariate analysis, the number of metastatic sites was the dominant prognostic indicator. After it was excluded from the analysis, the sIL-2R level and the metastatic site were found to be significant. It can be concluded, that high sICAM-1 levels suggest liver metastases and sIL-2R seems to serve as a marker of tumour load in metastatic melanoma. Furthermore, the sIL-2R level appears to add to clinical data predicting the patient's outcome.

Anti-inflammatory effects of 17beta-estradiol pretreatment in men after coronary artery surgery.

OBJECTIVE: To investigate the anti-inflammatory and hemodynamic effects of 17beta-estradiol in men undergoing elective coronary artery bypass graft surgery (CABG). DESIGN: Prospective, randomized, controlled. SETTING: Operating room and intensive care unit in a university hospital. PARTICIPANTS: Twenty-one men undergoing primary, elective CABG surgery. INTERVENTION: 17beta-estradiol, 2mg, was given orally twice in 14 hours before the operation. MEASUREMENTS AND MAIN RESULTS: Leukocyte counts, plasma myeloperoxidase, tumor necrosis factor-alpha, interleukin (IL)-6, IL-8, and IL-10 were measured perioperatively. Leukocyte counts were lower in the 17beta-estradiol group than in controls at 6 hours (11.4 +/- 2.0 hours v 15.5 +/- 4.7 hours x 10(9)/L) and 20 hours (11.6 +/- 1.9 hours v 13.6 +/- 2.5 hours x 10(9)/L) after reperfusion (p = 0.03). The release of myeloperoxidase was lower in the 17beta-estradiol group than in controls (5 minutes; 634.4 +/- 213.1 microg/mL v 773.1 +/- 209.3 microg/mL; 4 hours, 305.0 +/- 108.0 microg/mL v 441.3 +/- 191.6 microg/mL; p = 0.02). Systemic vascular resistance index was lower just after cardiopulmonary bypass, and cardiac index was higher postoperatively in the 17beta-estradiol group as compared with controls. CONCLUSION: Pretreatment with 17beta-estradiol can limit leukocyte activation in men after CABG surgery.