The Effect of Apolipoprotein E ɛ4 (APOE E4) on Visuospatial Working Memory in Healthy Elders and Amnestic Mild Cognitive Impairment Patients: An Event-related Potentials Study

Introduction

Previous studies provided inconsistent evidences for the effect of apolipoprotein E ɛ4 (APOE ɛ4) status on the visuospatial working memory (VSWM). Our study was the first investigation with event-related potential (ERP) to explore the effect of APOE ɛ4 on VSWM in healthy elders and aMCI patients.

Objective

The aim was to investigate the effect of APOE ɛ4 on VSWM with event-related potential (ERP) study in healthy elders and aMCI patients.

Methods

Thirty-nine aMCI patients (27 APOE ɛ4 non-carriers and 12 APOE ɛ4 carriers) and 43 their matched control (25 APOE ɛ4 non-carriers and 18 APOE ɛ4 carriers) performed an N-back task, a VSWM paradigm that manipulated the number of items to be stored in memory.

Results

Our study detected reduced accuracy and delayed mean correct response time in aMCI patients than healthy elders. P300 was elicited by VSWM and its amplitude was lower in aMCI patients at the central-parietal and parietal electrodes than healthy controls. In healthy elders, P300 amplitude declined prior to task performance change in APOE ɛ4 carriers than non-carriers. Regarding aMCI patients, P300 amplitude result revealed exacerbated VSWM deficits in APOE ɛ4 carriers than APOE ɛ4 non-carriers. Additionally, standardized low-resolution brain electromagnetic tomography analysis (s-LORETA) result showed enhanced brain activation in right parahippocampal gyrus during P300 time range in APOE ɛ4 carriers than non-carriers in aMCI patients (Fig. 1, Tables 1 and 2).

Conclusions

It demonstrated that P300 amplitude might serve as a biomarker for recognizing aMCI patients and contribute to early detection of worse VSWM in APOE ɛ4 carriers than non-carriers.

Disclosure of interest

The author has not supplied his/her declaration of competing interest.

Fast Surface Dynamics of Metallic Glass Enable Superlatticelike Nanostructure Growth

Contrary to the formation of complicated polycrystals induced by general crystallization, a modulated superlatticelike nanostructure, which grows layer by layer from the surface to the interior of a Pd_{40}Ni_{10}Cu_{30}P_{20} metallic glass, is observed via isothermal annealing below the glass transition temperature. The generation of the modulated nanostructure can be solely controlled by the annealing temperature, and it can be understood based on the fast dynamic and liquidlike behavior of the glass surface. The observations have implications for understanding the glassy surface dynamics and pave a way for the controllable fabrication of a unique and sophisticated nanostructure on a glass surface to realize the properties' modification.

FKBP12 enhances sensitivity to chemotherapy-induced cancer cell apoptosis by inhibiting MDM2

The FK506-binding protein 12 (FKBP12) is a cytoplasmic protein and has been reported to possess multiple functions in signaling transduction based on its interaction with different cellular targets. Here, we report that FKBP12 interacts with oncoprotein MDM2 and induces MDM2 degradation. We demonstrate that FKBP12 degrades MDM2 through binding to MDM2 protein, disrupting MDM2/MDM4 interaction and inducing MDM2 self-ubiquitination. The FKBP12-mediated MDM2 degradation was significantly enhanced when the transfected MDM2 was localized in the cytoplasm. The endogenous MDM2, when it was induced by p53 subjecting to DNA-damaging stimuli such as treatment with doxorubicin, was also significantly inhibited by FKBP12. This is due to translocation of p53-induced MDM2 from the nucleus to the cytoplasm, which facilitates interaction with cytoplasmic FKBP12. Furthermore, the enhanced level of MDM2 following p53 activation in nutlin-3 treated cells was also inhibited by FKBP12. The FKBP12-mediated downregulation of MDM2 in response to doxorubicin or nutlin-3 results in continuing and constitutive activation of p53, inhibition of XIAP and sensitization of cancer cells to apoptosis. These results identify a novel function for FKBP12 in downregulating MDM2, which directly enhances sensitivity of cancer cells to chemotherapy and nutlin-3 treatment.

Significant impact of amount of PCR input templates on various PCR-based DNA methylation analysis and countermeasure

Methylation changes of CpG islands can be determined using PCR-based assays. However, the exact impact of the amount of input templates (TAIT) on DNA methylation analysis has not been previously recognized. Using COL2A1 gene as an input reference, TAIT difference between human tissues with methylation-positive and -negative detection was calculated for two representative genes GFRA1 and P16. Results revealed that TAIT in GFRA1 methylation-positive frozen samples (n = 332) was significantly higher than the methylation-negative ones (n = 44) (P < 0.001). Similar difference was found in P16 methylation analysis. The TAIT-related effect was also observed in methylation-specific PCR (MSP) and denatured high performance liquid chromatography (DHPLC) analysis. Further study showed that the minimum TAIT for a successful MethyLight PCR reaction should be ≥ 9.4 ng (CtCOL2A1 ≤ 29.3), when the cutoff value of the methylated-GFRA1 proportion for methylation-positive detection was set at 1.6%. After TAIT of the methylation non-informative frozen samples (n = 94; CtCOL2A1 > 29.3) was increased above the minimum TAIT, the methylation-positive rate increased from 72.3% to 95.7% for GFRA1 and 26.6% to 54.3% for P16, respectively (Ps < 0.001). Similar results were observed in the FFPE samples. In conclusion, TAIT critically affects results of various PCR-based DNA methylation analyses. Characterization of the minimum TAIT for target CpG islands is essential to avoid false-negative results.

miR-137 plays tumor suppressor roles in gastric cancer cell lines by targeting KLF12 and MYO1C

Aberrant expression of miR-137 has been reported in many kinds of cancers, but its mechanisms seem to be diversely. In the present study, we compared the expression level of miR-137 in 18 paired gastric cancer (GC) samples and surgical margin (SM) samples by RNA extraction and quantitative real-time PCR (QRT-PCR). Then, we investigated the effects of miR-137 on cell proliferation, cell cycle, and cell migration separately by cell growth counting assay, cell cycle analysis, and transwell assay. Candidate targets of miR-137 were selected by biological information analysis from the intersection of miRDB, Pictar, and TarScan. Finally, mRNA and protein expression level of Krűppel-like factor 12 (KLF12) and Myosin 1C (MYO1C) were tested by QRT-PCR and western blotting assay, followed by the Luciferase reporter assay to investigate the direct interaction between them and miR-137. The results showed that miR-137 was down-regulated in GC samples than in SM samples. The expression level of miR-137 was significantly higher in patients without the vascular embolus than those with vascular embolus. And the overall survival time of patients with high miR-137 expression was longer than those with low miR-137 expression. Over expression of miR-137 could inhibit the cell migration, proliferation, and promote cell cycle arrest in G0/G1 stage in BGC-823 and SGC-7901 cell lines. KLF12 and MYO1C might be the candidate target genes of miR-137 with direct interactions between them and miR-137. In conclusion, miR-137 plays tumor suppressor roles in gastric cancer cell lines by targeting KLF12 and MYO1C.

Randomised clinical trial: prucalopride, a colonic pro-motility agent, reduces the duration of post-operative ileus after elective gastrointestinal surgery

BACKGROUND

Previous studies have shown that recovery of colonic transit is a major determinant of post-operative ileus and clinical recovery after gastrointestinal surgery. Prucalopride is a highly selective 5-hydroxytryptamine receptor-4 agonist with colonic pro-motility effects.

AIM

To evaluate the effect and safety of prucalopride on post-operative ileus and surgical outcomes after elective gastrointestinal surgery.

METHODS

In this phase II randomised clinical trial, 110 patients undergoing elective gastrointestinal surgery were randomised to either oral prucalopride (2 mg/day) (n = 55) or placebo (n = 55). Intervention was started 24 h after surgery and stopped after defecation or maximally at 7 days. The primary outcome was time to defecation. Secondary outcomes included time to first passage of flatus, tolerance of solid food, nasogastric tube reinsertion, post-operative length of stay, hospital readmission, overall cost, time to walk independently, surgical complications and inflammatory parameters.

RESULTS

Patients who received prucalopride had a shorter time to defecation (65.0 vs. 94.5 h, P = 0.001), passage of flatus (53.0 vs. 73.0 h, P < 0.001), and post-operative length of stay (7.0 vs. 8.0 days, P = 0.001) than controls. The number of patients with prolonged ileus (>5 days) (16.4% vs. 34.5%, P = 0.026) and the C-reactive protein level on post-operative day 5 (35.67 vs. 59.07 mg/L, P = 0.040) were lower in the prucalopride group. There was no significant difference in post-operative Clavien-Dindo grade III and IV complications (P = 0.606) between the groups.

CONCLUSION

Prucalopride is a safe and effective treatment to reduce post-operative ileus and systemic inflammation without affecting post-operative complications in patients undergoing elective gastrointestinal surgery. ClinicalTrials.gov: NCT02004652.

P16-specific DNA methylation by engineered zinc finger methyltransferase inactivates gene transcription and promotes cancer metastasis

Background

P16 DNA methylation is well known to be the most frequent event in cancer development. It has been reported that genetic inactivation of P16 drives cancer growth and metastasis, however, whether P16 DNA methylation is truly a driver in cancer metastasis remains unknown.

Results

A P16-specific DNA methyltransferase (P16-dnmt) expression vector is designed using a P16 promoter-specific engineered zinc finger protein fused with the catalytic domain of dnmt3a. P16-dnmt transfection significantly decreases P16 promoter activity, induces complete methylation of P16 CpG islands, and inactivates P16 transcription in the HEK293T cell line. The P16-Dnmt coding fragment is integrated into an expression controllable vector and used to induce P16-specific DNA methylation in GES-1 and BGC823 cell lines. Transwell assays show enhanced migration and invasion of these cancer cells following P16-specific DNA methylation. Such effects are not observed in the P16 mutant A549 cell line. These results are confirmed using an experimental mouse pneumonic metastasis model. Moreover, enforced overexpression of P16 in these cells reverses the migration phenotype. Increased levels of RB phosphorylation and NFκB subunit P65 expression are also seen following P16-specific methylation and might further contribute to cancer metastasis.

Conclusion

P16 methylation could directly inactivate gene transcription and drive cancer metastasis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-015-0819-6) contains supplementary material, which is available to authorized users.

USP4 inhibits p53 and NF-κB through deubiquitinating and stabilizing HDAC2

Histone deacetylases (HDACs) are major epigenetic modulators involved in a broad spectrum of human diseases including cancers. As HDACs are promising targets of cancer therapy, it is important to understand the mechanisms of HDAC regulation. In this study, we show that ubiquitin-specific peptidase 4 (USP4) interacts directly with and deubiquitinates HDAC2, leading to the stabilization of HDAC2. Accumulation of HDAC2 in USP4-overexpression cells leads to compromised p53 acetylation as well as crippled p53 transcriptional activation, accumulation and apoptotic response upon DNA damage. Moreover, USP4 targets HDAC2 to downregulate tumor necrosis factor TNFα-induced nuclear factor (NF)-κB activation. Taken together, our study provides a novel insight into the ubiquitination and stability of HDAC2 and uncovers a previously unknown function of USP4 in cancers.

Treatment of patients with diabetic peripheral neuropathic pain in China: a double-blind randomised trial of duloxetine vs. placebo

BACKGROUND

Duloxetine has been approved in the United States, European Union and some Asian countries for the treatment of diabetic peripheral neuropathic pain (DPNP). We assessed the efficacy and safety of duloxetine (60 mg once daily) compared with placebo in Chinese patients suffering from DPNP.

METHODS

This was a phase 3, multicenter, randomised, double-blind, parallel, placebo-controlled, 12-week trial of the treatment of DPNP with duloxetine. Subjects were male and female outpatients ≥ 18 years of age with DPNP, as assessed by the Michigan Neuropathy Screening Instrument, and had a rating of ≥ 4 on the Brief Pain Inventory-Modified Short Form-Severity weekly average pain item. The primary efficacy measure was the reduction in pain severity from baseline to 12 weeks, as measured by the weekly mean of 24-h average pain ratings recorded in the patient's diary. Mean changes from baseline in efficacy measures were analysed by a restricted maximum likelihood-based, mixed-effects model repeated measures approach and by analysis of covariance.

RESULTS

Of the 405 patients randomised, 203 patients were assigned to duloxetine 60 mg once daily and 202 patients were assigned to placebo. Duloxetine-treated patients showed significantly greater pain relief on 24-h average pain ratings compared with placebo-treated patients each week of the 12-week study period [week 12: least squares (LS) mean change duloxetine: -2.40, placebo: -1.97; LS mean change difference (95% confidence interval) = -0.43 (-0.82, -0.04), p = 0.030]. Compared with placebo, patients treated with duloxetine experienced higher rates of nausea (p = 0.010), somnolence (p < 0.001) and asthenia (p = 0.002).

CONCLUSIONS

Duloxetine-treated patients showed significantly greater pain relief compared with placebo-treated patients over the 12-week study period. Duloxetine was shown in Chinese patients to have a safety profile similar to that found in previous duloxetine trials.

Magnetism-Driven Ferroelectricity in Double Perovskite Y₂NiMnO₆

We report the discovery of multiferroic behavior in double perovskite Y2NiMnO6. X-ray diffraction shows that the material has a centrosymmetric crystal structure of space group P2(1)/n with Ni(2+)/Mn(4+) ordering. This result is further confirmed by aberration-corrected scanning transmission electron microscopy combined with atomic resolution electron energy loss spectroscopy. The appearance of ferroelectric polarization coincides with the magnetic phase transition (∼67 K), which indicates that the ferroelectricity is driven by magnetism, and this is further confirmed by its strong magnetoelectric (ME) effect. We proposed the origin of the ferroelectricity is associated with the combination of Ni(2+)/Mn(4+) charge ordering and the ↑↑↓↓ spin ordering. When compared with other known magnetic multiferroics, Y2NiMnO6 displays several attractive multiferroic properties, including high polarization (∼145 μC/m(2)), a high multiferroic transition temperature (∼67 K), and strong ME coupling (∼21%).

Kaiso mainly locates in the nucleus in vivo and binds to methylated, but not hydroxymethylated DNA

OBJECTIVE

Kaiso is upregulated in many cancers and proposed to bind with both methylated- and unmethylated-DNA in the nucleus as a transcriptional repressor. The objective is to define its subcellular localization in vivo and exact binding DNA sequences in cells.

METHODS

Compartmentalization of exogenous Kaiso in cells was tracked with enhanced green fluorescence protein (EGFP) tag. The endogenous Kaiso expression in gastric carcinoma tissue was examined with immunohistochemical staining. Kaiso-DNA binding was tested using electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation assay (ChIP).

RESULTS

Kaiso mainly localized in the nucleus of cancer and stromal cells in vivo, but remained in the cytoplasm of cultured cells. Most importantly, nuclear Kaiso can bind with the methylated-CGCG-containing sequence in the CDKN2A promoter, but not with the hydroxymethylated-CGCG sequence in HCT116 cells.

CONCLUSIONS

Kaiso locates mainly in the nucleus in vivo where it binds with the methylated-CGCG sequences, but does not bind with the hydroxymethylated-CGCG sequences.

Combined transplantation of autologous hematopoietic stem cells and allogenic mesenchymal stem cells increases T regulatory cells in systemic lupus erythematosus with refractory lupus nephritis and leukopenia

Autologous hematopoietic stem cell (HSC) and mesenchymal stem cell (MSC) transplantation is currently being evaluated as a novel treatment for autoimmune diseases, such as systemic lupus erythematosus (SLE). Here we report a case of autologous HSC transplantation combined with MSCs in a 25-year-old severe SLE patient with multiple life-threatening complications and refractory to conventional cyclophosphamide (CYC) therapy. After being pretreated with CYC, fludarabine and antithymocyte globulin, the patient was transplanted with autologous CD34+HSCs and MSCs by intravenous infusion. Hematopoietic regeneration was observed on day 12 thereafter. After HSC and MSC transplantation, the patient's clinical symptoms caused by SLE were remitted, and the SLEDAI score decreased. Moreover, CD4+CD25+FoxP3+Treg cells increased in peripheral blood mononuclear cells (PBMCs) after transplantation. This result suggests that the combined transplantation of HSCs and MSCs may reset the adaptive immune system to re-establish self-tolerance in SLE. A 36-month follow-up showed that the clinical symptoms remained in remission. Although a longer follow-up is required for assessing the long-term efficacy, our present results suggest that the combined transplantation of HSCs and MSCs may be a novel and effective therapy for refractory SLE.

P16 Methylation as an Early Predictor for Cancer Development From Oral Epithelial Dysplasia: A Double-blind Multicentre Prospective Study

Background

Silencing of P16 through methylation and locus deletion is the most frequent early events in carcinogenesis. The aim of this study is to prospectively determine if early P16 methylation is a predictor for oral cancer development.

Methods

Patients (n = 181) with mild or moderate oral epithelial dysplasia (OED) were recruited into the double blind multicentre cohort. P16 methylation was analyzed using the MethyLight assay. Progression of OEDs was monitored for a minimum 3 year follow-up period.

Findings

P16 methylation-informative cases (n = 152) were enrolled in the prospective multicenter cohorts with an ultimate compliance of 96.7%. OED-derived squamous cell carcinomas were observed in 21 patients (14.3%) during the follow-up (median, 41.0 months). The cancer progression rate from the P16 methylation-positive patients was significantly increased when compared to P16 methylation-negative patients [27.1% vs 8.1%; adjusted odds ratio = 4.6; P = 0.006]. When the P16 methylation-positive criteria were used as a biomarker for early prediction of cancer development from OEDs, sensitivity and specificity of 62% and 76% were obtained, respectively.

Interpretation

P16 methylation is unequivocally a marker for determining the malignant potential of OED and there is no need for further research regarding this aspect.

Funding

National Basic Research Programs of China (2011CB504201 and 2015CB553902), Beijing Science and Technology Commission (Z090507017709016), and Beijing Municipal Administration of Hospital (XM201303) to Dajun Deng. The funding agencies have no role in the actual experimental design, patient recruitment, data collection, analysis, interpretation, or writing of this manuscript.

•

P16 is most frequently inactivated through methylation and deletion in many cancers.

•

A multicentral prospective study was carried out to test association between P16 methylation and oral cancer development.

•

P16 methylation significantly increased risk of malignant transformation of oral epithelial dysplasia in Chinese patients.

Critical evaluation of Cbx7 downregulation in primary colon carcinomas and its clinical significance in Chinese patients

BACKGROUND

CBX7 is a Polycomb group protein that shows variable expression changes in various cancers that are often contradictive. A mouse knockout experiment has validated the tumor suppressor role in carcinogenesis. The purpose of this study is to verify the tumor suppressor role of Cbx7 in human colon carcinomas (CC).

METHODS

Frozen CC and the surgical margin (SM) tissue samples from patients (n = 97) were obtained from the Peking University Cancer Hospital. All patients had follow-up data for at least three years. The level of Cbx7 mRNA and protein was determined by quantitative RT-PCR, immunohistochemistry and Western blot, respectively. The association between Cbx7 mRNA level and clinicopathological characteristics of CC patients was then statistically analyzed.

RESULTS

CBX7 expression changes detected through immunohistochemistry and Western blot in 10 pairs of representative CC samples significantly correlated with their corresponding mRNA levels when Alu, but not GAPDH, was used as the endogenous reference control in quantitative RT-PCR. The Alu-normalized Cbx7 mRNA levels were significantly increased in SM tissues when compared with CC tissues or colon biopsies taken from non-cancer patients (Student's t-test, P < 0.036 or 0.007). Furthermore, decreased levels of Cbx7 mRNA positively correlated with lymph metastasis (P = 0.029). Overall survival (OS) of CC patients classified as Cbx7 expression-low was considerably shorter than those classified as Cbx7 expression-high (Hazard ratio = 2.97, 95% CI [1.68 ~ 5.25]; P <0.001). Multiple variant analyses showed that the Cbx7 expression-low was an independent predictor of short OS (Hazard ratio = 3.16, 95% CI [1.58-6.30]; P < 0.001).

CONCLUSION

Cbx7 is downregulated in CCs, and Cbx7 expression-low tumors correlated with lymph metastasis and poor overall survival of CC patients.

Visceral fat area is associated with a high risk for early postoperative recurrence in Crohn's disease

AIM

Mesenteric hypertrophy has been recognized as an indicator of the complicated course of Crohn's disease. The aim of this study was to investigate whether the visceral fat area (VFA) is associated with postoperative clinical and endoscopic recurrence.

METHOD

Computed tomography was used to measure the subcutaneous fat area and VFA, and the mesenteric fat index (MFI) was defined as the ratio of the VFA to the subcutaneous fat area. Associations between body mass index, subcutaneous fat area, VFA and MFI and postoperative clinical and endoscopic recurrence were investigated.

RESULTS

The factors associated with postoperative endoscopic recurrence at 6 months after surgery were a high VFA value (P = 0.019) and MFI values above the median (P = 0.008). VFA values were significantly correlated with endoscopic recurrence (r = 0.895, P = 0.040) and endoscopic lesions (r = 0.617, P < 0.0001). Additionally, MFI values correlated well with endoscopic recurrence (r = 0.918, P = 0.02) and endoscopic scores (r = 0.584, P < 0.0001). Multivariate analysis indicated that VFA values above the median (hazard ratio 2.63, 95% CI 1.03-6.74) were predictive of postoperative clinical recurrence in Crohn's disease.

CONCLUSION

A high VFA value is associated with postoperative recurrence of Crohn's disease and has clinical implications with respect to optimizing prophylaxis for each individual. However, further studies are needed to confirm the predictive role of this biomarker in a different data set.

An ecosystem-scale perspective of the net land methanol flux: synthesis of micrometeorological flux measurements

Methanol is the second most abundant volatile organic compound in the troposphere and plays a significant role in atmospheric chemistry. While there is consensus about the dominant role of living plants as the major source and the reaction with OH as the major sink of methanol, global methanol budgets diverge considerably in terms of source/sink estimates reflecting uncertainties in the approaches used to model, and the empirical data used to separately constrain these terms. Here we compiled micrometeorological methanol flux data from eight different study sites and reviewed the corresponding literature in order to provide a first cross-site synthesis of the terrestrial ecosystem-scale methanol exchange and present an independent data-driven view of the land-atmosphere methanol exchange. Our study shows that the controls of plant growth on the production, and thus the methanol emission magnitude, and stomatal conductance on the hourly methanol emission variability, established at the leaf level, hold across sites at the ecosystem-level. Unequivocal evidence for bi-directional methanol exchange at the ecosystem scale is presented. Deposition, which at some sites even exceeds methanol emissions, represents an emerging feature of ecosystem-scale measurements and is likely related to environmental factors favouring the formation of surface wetness. Methanol may adsorb to or dissolve in this surface water and eventually be chemically or biologically removed from it. Management activities in agriculture and forestry are shown to increase local methanol emission by orders of magnitude; they are however neglected at present in global budgets. While contemporary net land methanol budgets are overall consistent with the grand mean of the micrometeorological methanol flux measurements, we caution that the present approach of simulating methanol emission and deposition separately is prone to opposing systematic errors and does not allow taking full advantage of the rich information content of micrometeorological flux measurements.

An ecosystem-scale perspective of the net land methanol flux: synthesis of micrometeorological flux measurements

Methanol is the second most abundant volatile organic compound in the troposphere and plays a significant role in atmospheric chemistry. While there is consensus about the dominant role of living plants as the major source and the reaction with OH as the major sink of methanol, global methanol budgets diverge considerably in terms of source/sink estimates reflecting uncertainties in the approaches used to model, and the empirical data used to separately constrain these terms. Here we compiled micrometeorological methanol flux data from eight different study sites and reviewed the corresponding literature in order to provide a first cross-site synthesis of the terrestrial ecosystem-scale methanol exchange and present an independent data-driven view of the land-atmosphere methanol exchange. Our study shows that the controls of plant growth on the production, and thus the methanol emission magnitude, and stomatal conductance on the hourly methanol emission variability, established at the leaf level, hold across sites at the ecosystem-level. Unequivocal evidence for bi-directional methanol exchange at the ecosystem scale is presented. Deposition, which at some sites even exceeds methanol emissions, represents an emerging feature of ecosystem-scale measurements and is likely related to environmental factors favouring the formation of surface wetness. Methanol may adsorb to or dissolve in this surface water and eventually be chemically or biologically removed from it. Management activities in agriculture and forestry are shown to increase local methanol emission by orders of magnitude; they are however neglected at present in global budgets. While contemporary net land methanol budgets are overall consistent with the grand mean of the micrometeorological methanol flux measurements, we caution that the present approach of simulating methanol emission and deposition separately is prone to opposing systematic errors and does not allow taking full advantage of the rich information content of micrometeorological flux measurements.

AAV-mediated and pharmacological induction of Hsp70 expression stimulates survival of retinal ganglion cells following axonal injury

We evaluated the effect of AAV2- and 17-AAG (17-N -allylamino-17-demethoxygeldanamycin)-mediated upregulation of Hsp70 expression on the survival of retinal ganglion cells (RGCs) injured by optic nerve crush (ONC). AAV2-Hsp70 expression in the retina was primarily observed in the ganglion cell layer. Approximately 75% of all transfected cells were RGCs. RGC survival in AAV2-Hsp70 injected animals was increased by an average of 110% 2 weeks after the axonal injury compared to the control. The increase in cell numbers was not even across the retinas with a maximum effect of approximately 306% observed in the inferior quadrant. 17-AAG-mediated expression of Hsp70 has been associated with cell protection in various models of neurodegenerative diseases. We show here that a single intravitreal injection of 17-AAG (0.2 ug/ul) results in an increased survival of ONC injured RGCs by approximately 49% compared to the vehicle-treated animals. Expression of Hsp70 in retinas of 17-AAG-treated animals was upregulated approximately by 2-fold compared to control animals. Our data support the idea that the upregulation of Hsp70 has a beneficial effect on the survival of injured RGCs, and the induction of this protein could be viewed as a potential neuroprotective strategy for optic neuropathies.

Stapled vs hand suture closure of loop ileostomy: a meta-analysis

AIM

Loop ileostomies are widely used in colorectal surgery to reduce the consequences of distal anastomotic failure. The optimal surgical technique for their closure has yet not been defined. A meta-analysis was performed to compare the outcome after stapled or hand sutured ileostomy closure.

METHOD

An electronic literature search of EMBASE, PubMed and the Cochrane Library was undertaken to identify studies reporting stapled and hand sutured ileostomy closure. End-points included postoperative small bowel obstruction (SBO), anastomotic leakage, wound infection, overall postoperative complications, operation time, hospital stay and surgery-related cost.

RESULTS

Fourteen studies including 5084 patients were identified. Meta-analysis showed that stapled closure was associated with a lower rate of SBO overall (OR = 0.56, P < 0.00001) and early (within 30 days of closure) SBO (OR = 0.51, P < 0.00001). This difference persisted for direct ileostomy closure (OR = 0.62, P = 0.02) or closure with bowel resection and hand sewn anastomosis (OR = 0.44, P < 0.00001). Stapled closure required a shorter inpatient stay (mean difference -1.22, P < 0.0001) and operating time (mean difference -11.21, P = 0.01). No significant difference was noted between the two techniques in terms of anastomotic leakage, wound infection, overall complications or cost.

CONCLUSION

Stapled side-to-side anastomosis is associated with fewer complications, especially SBO, than hand sewn ileostomy closure by direct suture or resection and anastomosis. It is quicker to perform and associated with fewer postoperative bowel obstructions.