Randomized clinical trial of single-incision versus multiport laparoscopic colectomy

BACKGROUND

The efficacy and safety of single-incision laparoscopic colectomy (SILC) for colonic cancer remain unclear. The aim of this study was to determine the outcomes of SILC compared with multiport laparoscopic colectomy (MPLC) for colonic cancer.

METHODS

Patients with histologically proven colonic carcinoma located in the caecum, ascending, sigmoid or rectosigmoid colon, clinically diagnosed as stage 0-III by CT, were eligible for this study. Patients were randomized before surgery and underwent tumour dissection with complete mesocolic excision. Safety analyses were conducted according to randomization groups.

RESULTS

A total of 200 patients were enrolled and randomized to the MPLC (100 patients) or SILC (100 patients) arm. Surgical outcomes were similar between the MPLC and SILC arms, including duration of operation (mean 162 versus 156 min respectively; P = 0·273), blood loss (mean 8·8 versus 21·4 ml; P = 0·102), conversion to open laparotomy (2·0 versus 1·0 per cent; P = 0·561), reoperation (3·0 versus 3·0 per cent; P = 1·000), time to first flatus (both median 1 day; P = 0·155) and postoperative hospital stay (both median 6; P = 0·372). The total skin incision length was significantly shorter in the SILC arm (mean 4·4 cm versus 6·8 cm in the MPLC arm; P < 0·001). The median duration of analgesia use was 5 days in the MPLC and 4 days in the SILC arm (P = 0·485). Overall complication rates were equivalent (15·0 versus 12·0 per cent respecitvely; P = 0·680).

CONCLUSION

SILC is not superior to MPLC.

REGISTRATION NUMBER

UMIN000007220 (http://www.umin.ac.jp/ctr/index.htm).

Male sexual dysfunction after rectal cancer surgery: Results of a randomized trial comparing mesorectal excision with and without lateral lymph node dissection for patients with lower rectal cancer: Japan Clinical Oncology Group Study JCOG0212

BACKGROUND

We conducted a randomized controlled trial (JCOG0212) to determine whether the outcome of mesorectal excision (ME) alone for rectal cancer is not inferior to that of ME with lateral lymph node dissection (LLND). The present study focused on male sexual dysfunction after surgery.

METHODOLOGY

Eligibility criteria included clinical stage II/III rectal cancer, the lower margin of the lesion below the peritoneal reflection, the absence of lateral pelvic lymph node enlargement, and no preoperative radiotherapy. After confirmation of R0 resection by ME, patients were intraoperatively randomized. Questionnaires using the International Index of Erectile Function (IIEF-5) about the sexual function of men were collected before and 1 year after surgery. Sexual dysfunction incidence was defined as the ratio of patients showing sexual dysfunction after surgery relative to the number who had no erectile dysfunction before surgery.

RESULTS

Among 701 patients enrolled between June 2003 and August 2010, 472 males were included. Among them, 343 (73%) completed preoperative and postoperative questionnaires. According to the study protocol, the incidences of sexual dysfunction in patients who underwent ME alone and ME with LLND were 68% (17/25; 95%CI, 47-85%) and 79% (23/29; 95%CI, 60-92%), respectively (p = 0.37). Incidences of sexual dysfunction in patients with no or only mild erectile dysfunction before surgery who underwent ME alone and ME with LLND were 59% (48/81) and 71% (67/95), respectively (p = 0.15). Multivariate analysis identified age as the only risk factor for sexual dysfunction after surgery (p = 0.02).

CONCLUSIONS

LLND may not increase sexual dysfunction incidence after rectal cancer surgery. This incidence is associated with increased age. This trial is registered with ClinicalTrials.gov, number NCT00190541 and University Hospital Medical Information Network Clinical Trials Registry, number C000000034.

Profile comparison revealed deviation from structural constraint at the positively selected sites

The amino acid substitutions at a site are affected by mixture of various constraints. It is also known that the amino acid substitutions are accelerated at sites under positive selection. However, the relationship between the substitutions at positively selected sites and the constraints has not been thoroughly examined. The advances in computational biology have enabled us to divide the mixture of the constraints into the structural constraint and the remainings by using the amino acid sequences and the tertiary structures, which is expressed as the deviation of the mixture of constraints from the structural constraint. Here, two types of profiles, or matrices with the size of 20 x (site length), are compared. One of the profiles represents the mixture of constraints, and is generated from a multiple amino acid sequence alignment, whereas the other is designed to represent the structural constraints. We applied the profile comparison method to proteins under positive selection to examine the relationship between the positive selection and constraints. The results suggested that the constraint at a site under positive selection tends to be deviated from the structural constraint at the site.

'Transfer out' tuberculosis patients: treatment outcomes after cross-checking registers, 2012-2013, Lusaka, Zambia

SETTING

Lusaka, Zambia.

OBJECTIVE

To assess the actual treatment outcomes of 'transfer out' (TO) cases at a diagnostic centre in Lusaka, in the third and fourth quarters of 2012, and to see the impact of this cross-check in treatment success rates (TSR) in 2013 and early 2014.

DESIGN AND METHOD

In this retrospective cohort study, treatment outcomes for new bacteriologically positive tuberculosis (TB) cases referred from the diagnostic centre were reviewed and compared with those at the receiving treatment units.

RESULTS

Of 49 (58%) cases referred to three treatment units, the treatment outcomes of nine had to be updated at the diagnostic centre, which reduced the proportion of TO cases from 17.6% to 11.8% and increased the TSR to 70.6% from 64.7%.

CONCLUSION

The review and cross-checking of the TB registers at the diagnostic and treatment units led to a significant reduction in non-assessed cases, suggesting that the TB registers in the diagnostic and treatment units should be cross-checked regularly. There is also need for a complementary intervention to reduce the proportion of TOs associated with high loss to follow-up and non-evaluated TO rates.

Multiple-Localization and Hub Proteins

Protein-protein interactions are fundamental for all biological phenomena, and protein-protein interaction networks provide a global view of the interactions. The hub proteins, with many interaction partners, play vital roles in the networks. We investigated the subcellular localizations of proteins in the human network, and found that the ones localized in multiple subcellular compartments, especially the nucleus/cytoplasm proteins (NCP), the cytoplasm/cell membrane proteins (CMP), and the nucleus/cytoplasm/cell membrane proteins (NCMP), tend to be hubs. Examinations of keywords suggested that among NCP, those related to post-translational modifications and transcription functions are the major contributors to the large number of interactions. These types of proteins are characterized by a multi-domain architecture and intrinsic disorder. A survey of the typical hub proteins with prominent numbers of interaction partners in the type revealed that most are either transcription factors or co-regulators involved in signaling pathways. They translocate from the cytoplasm to the nucleus, triggered by the phosphorylation and/or ubiquitination of intrinsically disordered regions. Among CMP and NCMP, the contributors to the numerous interactions are related to either kinase or ubiquitin ligase activity. Many of them reside on the cytoplasmic side of the cell membrane, and act as the upstream regulators of signaling pathways. Overall, these hub proteins function to transfer external signals to the nucleus, through the cell membrane and the cytoplasm. Our analysis suggests that multiple-localization is a crucial concept to characterize groups of hub proteins and their biological functions in cellular information processing.

Investigation of the fatty acid transporter-encoding genes SLC27A3 and SLC27A4 in autism

The solute carrier 27A (SLC27A) gene family encodes fatty acid transport proteins (FATPs) and includes 6 members. During fetal and postnatal periods of development, the growing brain requires a reliable supply of fatty acids. Because autism spectrum disorders (ASD) are now recognized as disorders caused by impaired early brain development, it is possible that functional abnormalities of SLC27A genes may contribute to the pathogenesis of ASD. Here, we confirmed the expression of SLC27A3 and SLC27A4 in human neural stem cells derived from human induced pluripotent stem cells, which suggested their involvement in the developmental stage of the central nervous system. Additionally, we resequenced the SLC27A3 and SLC27A4 genes using 267 ASD patient and 1140 control samples and detected 47 (44 novel and 29 nonsynonymous) and 30 (17 novel and 14 nonsynonymous) variants for the SLC27A3 and SLC27A4, respectively, revealing that they are highly polymorphic with multiple rare variants. The SLC27A4 Ser209 allele was more frequently represented in ASD samples. Furthermore, we showed that a SLC27A4 Ser209 mutant resulted in significantly higher fluorescently-labeled fatty acid uptake into bEnd3 cells, a mouse brain capillary-derived endothelial cell line, compared with SLC27A4 Gly209, suggesting that the functional change may contribute to ASD pathophysiology.

Domain Motion Enhanced (DoME) Model for Efficient Conformational Sampling of Multidomain Proteins

Large conformational changes of multidomain proteins are difficult to simulate using all-atom molecular dynamics (MD) due to the slow time scale. We show that a simple modification of the structure-based coarse-grained (CG) model enables a stable and efficient MD simulation of those proteins. "Motion Tree", a tree diagram that describes conformational changes between two structures in a protein, provides information on rigid structural units (domains) and the magnitudes of domain motions. In our new CG model, which we call the DoME (domain motion enhanced) model, interdomain interactions are defined as being inversely proportional to the magnitude of the domain motions in the diagram, whereas intradomain interactions are kept constant. We applied the DoME model in combination with the Go model to simulations of adenylate kinase (AdK). The results of the DoME-Go simulation are consistent with an all-atom MD simulation for 10 μs as well as known experimental data. Unlike the conventional Go model, the DoME-Go model yields stable simulation trajectories against temperature changes and conformational transitions are easily sampled despite domain rigidity. Evidently, identification of domains and their interfaces is useful approach for CG modeling of multidomain proteins.

A Method for Systematic Assessment of Intrinsically Disordered Protein Regions by NMR

Intrinsically disordered proteins (IDPs) that lack stable conformations and are highly flexible have attracted the attention of biologists. Therefore, the development of a systematic method to identify polypeptide regions that are unstructured in solution is important. We have designed an "indirect/reflected" detection system for evaluating the physicochemical properties of IDPs using nuclear magnetic resonance (NMR). This approach employs a "chimeric membrane protein"-based method using the thermostable membrane protein PH0471. This protein contains two domains, a transmembrane helical region and a C-terminal OB (oligonucleotide/oligosaccharide binding)-fold domain (named NfeDC domain), connected by a flexible linker. NMR signals of the OB-fold domain of detergent-solubilized PH0471 are observed because of the flexibility of the linker region. In this study, the linker region was substituted with target IDPs. Fifty-three candidates were selected using the prediction tool POODLE and 35 expression vectors were constructed. Subsequently, we obtained 15N-labeled chimeric PH0471 proteins with 25 IDPs as linkers. The NMR spectra allowed us to classify IDPs into three categories: flexible, moderately flexible, and inflexible. The inflexible IDPs contain membrane-associating or aggregation-prone sequences. This is the first attempt to use an indirect/reflected NMR method to evaluate IDPs and can verify the predictions derived from our computational tools.

Increased protein and mRNA expression of resistin after dexamethasone administration

Synthetic glucocorticoids such as dexamethasone are widely used to treat a variety of inflammatory and autoimmune conditions, but they may induce adverse events including hyperglycemia. To shed light on the effect and action mechanism of dexamethasone, we examined the alterations of gene expression levels caused by dexamethasone.Microarray analysis was performed on whole blood collected from 24 physically healthy subjects at baseline and after dexamethasone administration. The expression levels of resistin mRNA were found to be significantly increased after the dexamethasone administration. In a separate sample of 12 subjects, we examined plasma resistin protein levels and found that they were increased after dexamethasone administration. Furthermore, the plasma mRNA and protein levels of resistin were significantly higher in individuals who carried the A allele of RETN single nucleotide polymorphism rs3219175 than in those who did not carry the allele. There was no significant interaction between the genotype and dexamethasone administration. No significant correlation was found between plasma levels of cortisol and resistin. Consistent with previous studies, the genotype of RETN rs3219175 was a strong determinant of resistin levels. The present study showed that oral administration of dexamethasone increases the protein and mRNA levels of resistin irrespective of the rs3219175 genotype.

Dielectric-loaded surface plasmon polariton crossing waveguides using multimode interference

A low-loss low-crosstalk multimode interference (MMI) crossing design for dielectric-loaded surface plasmon polariton waveguides (DLSPPWs), which are SiO2 stripes on Au films, is demonstrated numerically and experimentally. DLSPPWs are compatible with strong surface plasmon polariton (SPP) field confinement and maintain relatively low propagation losses. Unlike simpler crossings without MMI structures, low insertion loss of 0.65 dB and low crosstalk of -20.27  dB is confirmed numerically at a crossing angle of 10° when using tilted mirror-imaged MMI crossings. Similar insertion losses were also confirmed experimentally. The proposed structure will be beneficial for plasmonic device miniaturization and flexible patterning of optical interconnections.

An optimized Npro-based method for the expression and purification of intrinsically disordered proteins for an NMR study

Intrinsically disordered proteins (IDPs) are an emerging concept. IDPs have high flexibility in their polypeptide chains, lacking a stable 3-dimensional structure. Because of the difficulty in performing X-ray crystallography for IDPs, nuclear magnetic resonance (NMR) spectroscopy is the first choice for atomic-level investigation of their nature. Given that isotopically labeled IDP samples are necessary for NMR study, a robust and cost-effective protocol for bacterial expression and purification of IDP is also needed. We employed the N^pro (EDDIE)-autoprotease fusion protein system. Although IDPs are believed to be readily degraded by endogenous proteases when expressed in Escherichia coli, N^pro-fused IDPs showed excellent resistance to degradation. Seven IDPs of uncharacterized function sampled from the human genome as well as 3 constructs from IDP regions derived from human FancM and Thermococcus kodakarensis Hef were prepared. We improved the protocol of refolding of N^pro (EDDIE) to use dialysis, which is convenient for subsequent purification using reversed-phase (RP) HPLC. The method is robust and widely applicable to any IDP sample, promoting the acquisition of experimental data for IDPs in a high-throughput manner.

Optimizing the selection of patients with low rectal cancer for intersphincteric resection by evaluating vertical invasion to the levator and external sphincter

AIM

The indications for intersphincteric (ISR) anterior resection are not clearly defined. The aim of this study was to evaluate vertical extension of T2 or T3 low rectal cancer treated by rectal amputation to optimize patient selection for ISR.

METHOD

The abdominoperineal excision specimens of T2 or T3 low rectal cancer from 53 patients treated between 1992 and 2004 were retrospectively reviewed. Vertical invasion was quantified by measuring the shortest distance between the tumour and the striated muscle (T-SM), assuming that this represented the surgical margin that would have be achieved had an ISR been performed.

RESULTS

Involvement of the dentate line (DL) and intramural distal spread were independent risk factors for T-SM ≤ 2 mm. The T-SM was less when the inferior border of the tumour was on the distal side of the DL (r = 0.572, P < 0.001). The probability of involvement of the DL, intramural distal spread or either one of these being associated with T-SM ≤ 2 mm was 43, 46 and 43%, respectively. All patients without both intramural distal spread and involvement of the DL had T-SM > 2.

CONCLUSION

We recommend that ISR should only be performed for patients with T2 or T3 low rectal cancer in whom the lowest edge of the tumour is above the DL and there is no intramural distal spread. Such patients are relatively unlikely to have a T-SM ≤ 2 mm.

Nutritional management of anastomotic leakage after colorectal cancer surgery using elemental diet jelly

BACKGROUND/AIMS

Anastomotic leakage is major complication of colorectal surgery. Total parenteral nutrition (TPN) and fasting are conservative treatments for leakage in the absence of peritonitis in Japan. Elemental diet (ED) jelly is a completely digested formula and is easily absorbed without secretion of digestive juices. The purpose of this study was to assess the safety of ED jelly in management of anastomotic leakage.

METHODOLOGY

Six hundred and two patients who underwent elective surgery for left side colorectal cancer from January 2008 to December 2011 were included in the study. Pelvic drainage was performed for all patients. Sixty-three (10.5%) patients were diagnosed with an anastomotic leakage, and of these, 31 (5.2%) without diverting stoma were enrolled in this study.

RESULTS

Sixteen patients received TPN (TPN group) and 15 patients received ED jelly (ED group). The duration of intravenous infusion was significantly shorter in the ED group than in the TPN group (15 days versus 25 days, P= 0.008). In the TPN group, catheter infection was occurred in 2 patients who required re-insertion of the catheter.

CONCLUSION

Conservative management of anastomotic leakage after colorectal surgery with ED jelly appears to be a safe and useful approach.

Exon resequencing of H3K9 methyltransferase complex genes, EHMT1, EHTM2 and WIZ, in Japanese autism subjects

Background

Histone H3 methylation at lysine 9 (H3K9) is a conserved epigenetic signal, mediating heterochromatin formation by trimethylation, and transcriptional silencing by dimethylation. Defective GLP (Ehmt1) and G9a (Ehmt2) histone lysine methyltransferases, involved in mono and dimethylation of H3K9, confer autistic phenotypes and behavioral abnormalities in animal models. Moreover, EHMT1 loss of function results in Kleefstra syndrome, characterized by severe intellectual disability, developmental delays and psychiatric disorders. We examined the possible role of histone methyltransferases in the etiology of autism spectrum disorders (ASD) and suggest that rare functional variants in these genes that regulate H3K9 methylation may be associated with ASD.

Methods

Since G9a-GLP-Wiz forms a heteromeric methyltransferase complex, all the protein-coding regions and exon/intron boundaries of EHMT1, EHMT2 and WIZ were sequenced in Japanese ASD subjects. The detected variants were prioritized based on novelty and functionality. The expression levels of these genes were tested in blood cells and postmortem brain samples from ASD and control subjects. Expression of EHMT1 and EHMT2 isoforms were determined by digital PCR.

Results

We identified six nonsynonymous variants: three in EHMT1, two in EHMT2 and one in WIZ. Two variants, the EHMT1 ankyrin repeat domain (Lys968Arg) and EHMT2 SET domain (Thr961Ile) variants were present exclusively in cases, but showed no statistically significant association with ASD. The EHMT2 transcript expression was significantly elevated in the peripheral blood cells of ASD when compared with control samples; but not for EHMT1 and WIZ. Gene expression levels of EHMT1, EHMT2 and WIZ in Brodmann area (BA) 9, BA21, BA40 and the dorsal raphe nucleus (DoRN) regions from postmortem brain samples showed no significant changes between ASD and control subjects. Nor did expression levels of EHMT1 and EHMT2 isoforms in the prefrontal cortex differ significantly between ASD and control groups.

Conclusions

We identified two novel rare missense variants in the EHMT1 and EHMT2 genes of ASD patients. We surmise that these variants alone may not be sufficient to exert a significant effect on ASD pathogenesis. The elevated expression of EHMT2 in the peripheral blood cells may support the notion of a restrictive chromatin state in ASD, similar to schizophrenia.

Electronic supplementary material

The online version of this article (doi:10.1186/2040-2392-5-49) contains supplementary material, which is available to authorized users.