Association between homeobox protein transcript antisense intergenic ribonucleic acid genetic polymorphisms and cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CCA) represents a rare but highly aggressive malignancy that is often challenging to diagnose, especially in early stages. The role of existing tumor biomarkers for CCA diagnosis, remains controversial due to their low sensitivity and specificity. Increasing evidence has implicated long non-coding ribonucleic acid polymorphisms with cancer susceptibility in a variety of tumor types. The association between long non-coding ribonucleic acid homeobox protein transcript antisense intergenic ribonucleic acid (HOTAIR) polymorphisms and CCA risk has not been reported yet.

AIM

To investigate the influence of HOTAIR variants on the risk of CCA development.

METHODS

We conducted a case-control study in which three HOTAIR single nucleotide polymorphisms (rs920778, rs4759314 and rs7958904) were genotyped in a Greek cohort. Our study population included 122 CCA patients (80 males and 42 females) and 165 healthy controls. The polymorphisms under investigation were examined in peripheral blood samples.

RESULTS

HOTAIR rs4759314 AG and GG genotypes were associated with a significantly increased CCA risk [P = 0.004, odds ratio: 3.13; 95% confidence interval: 1.65-5.91 and P = 0.005, odds ratio: 12.31; 95% confidence interval: 1.48-101.87, respectively]. However, no significant associations of HOTAIR rs920778, and rs7958904 were detected. Similarly, we found no significant associations between rs4759314 AA genotype and CCA susceptibility.

CONCLUSION

HOTAIR rs4759314 AG and GG genotypes may be implicated with CCA development and may serve as a potential diagnostic biomarker.

Photon beam energy dependent single-arc volumetric modulated arc optimization

PURPOSE

The purpose of this work was to present a new single-arc mixed photon (6&18MV) VMAT (SAMP) optimization framework that concurrently optimizes for two photon energies with corresponding partial arc lengths.

METHODS AND MATERIALS

Owing to simultaneous optimization of energy dependent intensity maps and corresponding arc locations, the proposed model poses nonlinearity. Unique relaxation constraints based on McCormick approximations were introduced for linearization. Energy dependent intensity maps were then decomposed to generate apertures. Feasibility of the proposed framework was tested on a sample of ten prostate cancer cases with lateral separation ranging from 34 cm (case no.1) to 52 cm (case no.6). The SAMP plans were compared against single energy (6MV) VMAT (SE) plans through dose volume histograms (DVHs) and radiobiological parameters including normal tissue complication probability (NTCP) and equivalent uniform dose (EUD).

RESULTS

The contribution of higher energy photon beam optimized by the algorithm demonstrated an increase for cases with a lateral separation >40 cm. SAMP-VMAT notably improved bladder and rectum sparing in large size cases. Compared to single energy, SAMP-VMAT plans reduced bladder and rectum NTCP in cases with large lateral separation. With the exception of one case, SAMP-VMAT either improved or maintained femoral heads compared to SE-VMAT. SAMP-VMAT reduced the nontarget tissue integral dose in all ten cases.

CONCLUSIONS

A single-arc VMAT optimization framework comprising mixed photon energy partial arcs was presented. Overall results underline the feasibility and potential of the proposed approach for improving OAR sparing in large size patients without compromising the target homogeneity and coverage.

Place of hyperthermic intraperitoneal chemotherapy in the armament against pancreatic adenocarcinoma: A survival, mortality and morbidity systematic review

Pancreatic adenocarcinoma is one of the deadliest types of cancer worldwide, with a 5-year survival rate of 8% despite recent treatment advancements. The present systematic review aimed to investigate the role of hyperthermic intraperitoneal chemotherapy (HIPEC) following surgical resection for pancreatic adenocarcinoma, with or without peritoneal carcinomatosis. A systematic search of the MEDLINE and SCOPUS electronic databases was performed according to PRISMA guidelines. All possible relevant articles published between January 1980 and May 2019 were retrieved using multiple search terms associated with HIPEC and pancreatic adenocarcinoma. The initial search resulted in 1,244 reports, which condensed to 41 reports following screening of titles and abstracts, and subsequently to four reports following full-text thorough examination. The four reports included involved a prospective cohort study of HIPEC use in resectable pancreatic adenocarcinoma, and three retrospective studies of HIPEC use following cytoreductive surgery for peritoneal carcinomatosis due to pancreatic adenocarcinoma, resulting in a total of 47 patients. The overall survival ranged between 2 and 62 months, and the hospital mortality rate was 8.5%. Morbidity (34%) was mainly attributed to anastomotic leak or respiratory failure. Due to the small sample size and low quality of evidence of the included studies, no valid conclusions could be drawn. Therefore, further studies are required to justify the use of HIPEC as an adjuvant therapy in resectable pancreatic adenocarcinoma, while cytoreductive surgery and HIPEC in peritoneal carcinomatosis of pancreatic origin seems not only not useful but also unsafe at this level of evidence.

Strong Coupling of Organic Dyes Located at the Surface of a Dielectric Slab Microcavity

Strong coupling to the electronic or vibronic transitions of an organic semiconductor has been extensively studied in microcavity structures in which a molecular film is placed between two closely spaced mirrors. Recent experiments suggest that such strong coupling can be used to modify chemical reactions; however, the geometry of conventional microcavity structures makes such studies difficult as they limit the ability of molecules to interact with their local environment. Here, we show that optical strong coupling to a molecular film can be achieved even when such molecules are located on the surface of a dielectric slab. We then show that such molecules on the surface of the slab can undergo facile interactions with molecules in their surrounding environment, and evidence a reversible protonation/deprotonation reaction by exposing a surface-bound porphyrin to an acidic or basic vapor. Although our proof-of-principle measurements do not evidence any change in reaction rates, we believe our structures represent a promising system in which to explore polariton-driven chemical phenomena.

Strong Coupling of Organic Dyes Located at the Surface of a Dielectric Slab Microcavity

Strong coupling to the electronic or vibronic transitions of an organic semiconductor has been extensively studied in microcavity structures in which a molecular film is placed between two closely spaced mirrors. Recent experiments suggest that such strong coupling can be used to modify chemical reactions; however, the geometry of conventional microcavity structures makes such studies difficult as they limit the ability of molecules to interact with their local environment. Here, we show that optical strong coupling to a molecular film can be achieved even when such molecules are located on the surface of a dielectric slab. We then show that such molecules on the surface of the slab can undergo facile interactions with molecules in their surrounding environment, and evidence a reversible protonation/deprotonation reaction by exposing a surface-bound porphyrin to an acidic or basic vapor. Although our proof-of-principle measurements do not evidence any change in reaction rates, we believe our structures represent a promising system in which to explore polariton-driven chemical phenomena.

Performance Assessment of Subjects With Nursing Education Trained in Sigmoidoscopy by Means of a Simulator

Reports evaluating simulation-based sigmoidoscopy training among nurses are scarce. The aim of this prospective nonrandomized study was to assess the performance of nurses in simulated sigmoidoscopy training and the potential impact on their performance of endoscopy unit experience, general professional experience, and skills in manual activities requiring coordinated maneuvers. Forty-four subjects were included: 12 nurses with (Group A) and 14 nurses without endoscopy unit experience (Group B) as well as 18 senior nursing students (Group C). All received simulator training in sigmoidoscopy. Participants were evaluated with respect to predetermined validated metrics. Skills in manual activities requiring coordinated maneuvers were analyzed to draw possible correlations with their performance. The total population required a median number of 5 attempts to achieve all predetermined goals. Groups A and C outperformed Group B regarding the number of attempts needed to achieve the predetermined percentage of visualized mucosa (p = .017, p = .027, respectively). Furthermore, Group A outperformed Group B regarding the predetermined duration of procedure (p = .046). A tendency was observed for fewer attempts needed to achieve the overall successful endoscopy in both Groups A and C compared with Group B. Increased score on playing stringed instruments was associated with decreased total time of procedure (rs = -.34, p = .03) and with decreased number of total attempts for successful endoscopy (rs = -.31, p = .046). This study suggests that training nurses and nursing students in simulated sigmoidoscopy is feasible by means of a proper training program. Experience in endoscopy unit and skills in manual activities have a positive impact on the training process.

Salivary dysfunction caused by medication usage

A considerable number of patients arriving in dental offices are being treated with ongoing medication for a variety of chronic diseases. As a result, dentists must be familiar with the potential side effects these therapeutic agents may have on the tissues of the oral cavity, and in particular on the salivary gland. Salivary gland function may be altered by a wide range of medications, leading to effects such as xerostomia, hyposalivation, hypersalivation or even swelling of the glands. These disorders can cause a variety of other health complications. This review will focus on the most common groups of drugs responsible for salivary gland dysfunction, including psychoactive drugs, antidepressants, antipsychotics, antihypertensives, and antihistamines.

Intraoperative Indocyanine Green (ICG) Angiography for the Identification of the Parathyroid Glands: Current Evidence and Future Perspectives

BACKGROUND/AIM

Recently, indocyanine green (ICG) fluorescence imaging has been used for the identification of the parathyroid glands (PG) during thyroid and parathyroid surgery. However, an overall consensus on the optimal technique, the dosage, the timing of the ICG administration and finally its interpretation and clinical usefulness is still lacking evidence. The aim of this review is to investigate the use of ICG angiography during thyroidectomy and/or parathyroidectomy for identification as well as for the perfusion integrity of the parathyroid glands.

MATERIALS AND METHODS

The PubMed database was systematically searched for publications regarding intraoperative ICG imaging in patients that undergo thyroidectomy or parathyroidectomy.

RESULTS

Eighteen publications reporting on 612 patients, namely 71 parathyroidectomy and 541 thyroidectomy patients met the inclusion criteria. Eleven publications reported the use of ICG angiography for the identification of the parathyroid glands during thyroidectomy and seven during parathyroidectomy for primary and secondary hyperparathyroidism.

CONCLUSION

ICG fluorescence imaging is a simple, fast and reproducible method capable of intraoperatively visualizing and assessing the function of parathyroid glands, and can, therefore, assist surgeons in their decision-making. Despite all this, ICG fluorescence imaging technique for PG detection still lacks standardization and further studies are needed to establish its clinical utility.

Validation of a Novel Needle Holder to Train Advanced Laparoscopy Skills to Novices in a Simulator Environment

Background. Our aim was to determine if a newly designed Najar needle holder (NNH) shortens the time for novices to improve advanced laparoscopy (AL) techniques (suturing/knot tying), compared with a conventional macro needle holder (MNH) in a simulator. Furthermore, we aimed to validate a new video scoring system determining AL skills. Methods. Forty-six medical students performed identical surgical tasks in a prospective, crossover study evaluating AL skills (NNH vs MNH). All subjects performed a double-throw knot, 2 single-throw knots following 3 running sutures in the Simball Box (SB) simulator. After resting, subjects switched needle holders. All tasks were videotaped and analyzed using SB software and by 2 independent reviewers using the Objective Video Evaluation Scoring Table (OVEST). Trial performance expressed as SB Overall Score (SBOS) and OVEST. Results. In the group starting with NNH (followed by MNH) OVEST was consistently high during both trials (median = 12.5, range = 6.5-18.0, and median = 13.5, range = 6.5-21.0; P = .2360). However, in the group starting with MNH, OVEST improved significantly when the participants changed to NNH (median = 10.0, range = 2.5-19.5, vs median = 14.5, range = 4.5-18.0; P = .0003); an improvement was also found with SBOS (median = 37%, range = 27% to 92%, vs median = 48%, range = 34% to 70%; P = .0289). In both trials, both independent reviewers' OVEST measures correlated well: Trial 1: β = 0.97, P < .0001; and Trial 2: β = 0.95, P < .0001. A correlation also existed between SBOS and OVEST in both trials (β = 2.1, P < .0001; and β = 1.9, P = .0002). Conclusions. This study indicates a significantly higher improvement in laparoscopic suturing skills in novices training AL skills using NNH compared with MNH. Starting early, AL training in novices using NNH is a feasible option. Furthermore, OVEST used in experimental settings as an evaluation tool is comparable with the validated SBOS.

Can 3D Vision Improve Laparoscopic Performance in Box Simulation Training when Compared to Conventional 2D Vision?

INTRODUCTION

Three-dimensional (3D) imaging systems have been introduced in laparoscopic surgery to facilitate binocular vision and dexterity to improve surgical performance and safety. Several studies have shown the benefits of 3D imaging in laparoscopy, but until now only a few studies have assessed the outcome by using objective variables. Box trainers are affordable alternatives to virtual laparoscopic surgical training, and the possibility of using real surgical instruments makes them more realistic to use. However, the data and feedback by a virtual simulator have not, until now, been able to assess. Simball Box®, equipped with G-coder sensors®, registers the instrument movements during training and gives the same feedback like a virtual simulator.

AIM

The aim of this study was to objectively evaluate the laparoscopic performance in 3D compared to conventional 2D vision by using a box simulation trainer.

MATERIALS AND METHODS

Thirty surgeons, residents and consultants, participated in the study. Eighteen had no, or minimal, laparoscopic experience (novices) whereas 12 were experts. They all performed three standard box training exercises (rope race, precision cutting, and basic suturing) in Simball Box. The participants were randomized and started with either 3D HD or traditional 2D HD cameras. The exercises were instructed and supervised. All instrument movements were registered. Variations in time, linear distance, average speed, and motion smoothness were analyzed.

RESULTS

The parameters time, distance, speed, and motion smoothness were significantly better when the 3D camera was used.

CONCLUSION

All individuals of both subgroups achieved significantly higher speed and better motion smoothness when using 3D.

Simultaneous optimization of mixed photon energy beams in volumetric modulated arc therapy

PURPOSE

Despite the availability of multiple energy photon beams on clinical linear accelerators, volumetric modulated arc therapy (VMAT) optimization is currently limited to a single photon beam. The purpose of this work was to present a proof-of-principle study on an algorithm for simultaneous optimization of mixed photon beams for VMAT (MP - VMAT), utilizing an additional photon energy as an additional degree of freedom.

METHODS

The MP - VMAT optimization algorithm is presented as a two-step heuristic approach. First, a convex linear programming problem is solved for simultaneous optimization of nonuniform dual energy intensity maps (DEIMs) for an angular resolution of 36 equi-spaced beam segments. Subsequently, for a given gantry speed schedule, the second step aims to best replicate each DEIM by dispersing MP - VMAT apertures along with their corresponding intensities over their respective beam segment. This constitutes a nonlinear problem, which is linearized using McCormick relaxation. The final large-scale mixed integer linear programming (MILP) dispersion model ensures a contiguous and smooth transition of multileaf collimators (MLCs) from one beam segment to the next. To demonstrate the proof-of-principle, we first compared the quality of dose volume histograms (DVHs) of MP - VMAT to the ones calculated from 36 DEIMs following the step 1 of MP - VMAT model. Additionally, the MLCs motion violations were evaluated for the complete 360° gantry rotation for gantry speeds ranging from 1 to 6° per second. The quality of MP - VMAT plans were also compared to conventional single energy VMAT plans via DVH, homogeneity index (HI), and conformity number (CN) for two prostate cases.

RESULTS

The MP - VMAT model resulted in a successful convergence of DVHs relative to the ones from DEIMs with HI and CN of 0.05 and 0.9, respectively, for 1 and 2° per second gantry speed schedules. In replicating the DEIMs, the MILP dispersion model was able to achieve optimality for almost all segments at 1° per second and for majority of segments at 2° per second. Although, DVHs quality was slightly inferior for 3° per second gantry speed, the target conformity of 0.9 and heterogeneity of 0.08 were achievable even for the suboptimal solutions. No violations of the MLC constraints were observed throughout the complete 360 degree arc rotation for any gantry speed schedule, thereby confirming MILP dispersion model. For the two prostate cases, the results showed MP - VMAT's ability to achieve substantial dose reduction in rectum and bladder while yielding similar target coverage compared to single energy VMAT. Bladder volume was mostly spared in low-to-intermediate dose region. Rectal volume sparing (3 % to 12 %) was observed in the intermediate (from 25 to 50 Gy) dose region.

CONCLUSION

We demonstrate the first formalism of a large-scale simultaneous optimization of mixed photon energy beams for VMAT. Dosimetric comparison of MP - VMAT to single energy VMAT demonstrated potential advantages of using mixed photon energy beams for prostate plans, thus providing an impetus for further testing on a large clinical cohort.

The Role of 3D Printing in Colorectal Surgery: Current Evidence and Future Perspectives

BACKGROUND

Three-dimensional (3D) printing is an emerging and evolving technology with a variety of possible applications in surgery. The purpose of this study was to examine its potential applications in the field of colorectal surgery, as a tool in pre-operative planning and peri-operative navigation, as well as in training. Its cost-efficiency was also examined.

MATERIALS AND METHODS

A literature review was conducted on articles specifically presenting various applications of 3D printing in the field of colorectal surgery. PubMed was the primary database researched.

RESULTS

A total of seven studies were found to meet the inclusion criteria. The majority of the articles employed 3D printing technology to produce patient-specific anatomic replicas to enhance pre-operative planning, providing satisfactory results. One study used 3D printing technology as a therapy tool, stating superior results over traditional methods.

CONCLUSION

3D printing is a novel technology with a broad spectrum of possible applications in colorectal surgery. Anatomic replicas specific to the anatomy of a patient with acceptable dimensional correlations can be produced using the currently available technology. Surgical and patient training can also be enhanced. Depending on the technology used, costs greatly vary and can thus hinder popularization of this technology in surgery.

MRI-Related Geometric Distortions in Stereotactic Radiotherapy Treatment Planning: Evaluation and Dosimetric Impact

In view of their superior soft tissue contrast compared to computed tomography, magnetic resonance images are commonly involved in stereotactic radiosurgery/radiotherapy applications for target delineation purposes. It is known, however, that magnetic resonance images are geometrically distorted, thus deteriorating dose delivery accuracy. The present work focuses on the assessment of geometric distortion inherent in magnetic resonance images used in stereotactic radiosurgery/radiotherapy treatment planning and attempts to quantitively evaluate the consequent impact on dose delivery. The geometric distortions for 3 clinical magnetic resonance protocols (at both 1.5 and 3.0 T) used for stereotactic radiosurgery/radiotherapy treatment planning were evaluated using a recently proposed phantom and methodology. Areas of increased distortion were identified at the edges of the imaged volume which was comparable to a brain scan. Although mean absolute distortion did not exceed 0.5 mm on any spatial axis, maximum detected control point disposition reached 2 mm. In an effort to establish what could be considered as acceptable geometric uncertainty, highly conformal plans were utilized to irradiate targets of different diameters (5-50 mm). The targets were mispositioned by 0.5 up to 3 mm, and dose–volume histograms and plan quality indices clinically used for plan evaluation and acceptance were derived and used to investigate the effect of geometrical uncertainty (distortion) on dose delivery accuracy and plan quality. The latter was found to be strongly dependent on target size. For targets less than 20 mm in diameter, a spatial disposition of the order of 1 mm could significantly affect (>5%) plan acceptance/quality indices. For targets with diameter greater than 2 cm, the corresponding disposition was found greater than 1.5 mm. Overall results of this work suggest that efficacy of stereotactic radiosurgery/radiotherapy applications could be compromised in case of very small targets lying distant from the scanner’s isocenter (eg, the periphery of the brain).

Surgeons' and surgical trainees' acute stress in real operations or simulation: A systematic review

BACKGROUND AND PURPOSE

Acute stress in surgery is ubiquitous and has an immediate impact on surgical performance and patient safety. Surgeons react with several coping strategies; however, they recognise the necessity of formal stress management training. Thus, stress assessment is a direct need. Surgical simulation is a validated standardised training milieu designed to replicate real-life situations. It replicates stress, prevents biases, and provides objective metrics. The complexity of stress mechanisms makes stress measurement difficult to quantify and interpret. This systematic review aims to identify studies that have used acute stress estimation measurements in surgeons or surgical trainees during real operations or surgical simulation, and to collectively present the rationale of these tools, with special emphasis in salivary markers.

METHODS

A search strategy was implemented to retrieve relevant articles from MEDLINE and SCOPUS databases. The 738 articles retrieved were reviewed for further evaluation according to the predetermined inclusion/exclusion criteria.

RESULTS

Thirty-three studies were included in this systematic review. The methods for acute stress assessment varied greatly among studies with the non-invasive techniques being the most commonly used. Subjective and objective tests for surgeons' acute stress assessment are being presented.

CONCLUSION

There is a broad spectrum of acute mental stress assessment tools in the surgical field and simulation and salivary biomarkers have recently gained popularity. There is a need to maintain a consistent methodology in future research, towards a deeper understanding of acute stress in the surgical field.

Video analysis in basic skills training: a way to expand the value and use of BlackBox training?

Background

Basic skills training in laparoscopic high-fidelity simulators (LHFS) improves laparoscopic skills. However, since LHFS are expensive, their availability is limited. The aim of this study was to assess whether automated video analysis of low-cost BlackBox laparoscopic training could provide an alternative to LHFS in basic skills training.

Methods

Medical students volunteered to participate during their surgical semester at the Karolinska University Hospital. After written informed consent, they performed two laparoscopic tasks (PEG-transfer and precision-cutting) on a BlackBox trainer. All tasks were videotaped and sent to MPLSC for automated video analysis, generating two parameters (Pl and Prtcl_tot) that assess the total motion activity. The students then carried out final tests on the MIST-VR simulator. This study was a European collaboration among two simulation centers, located in Sweden and Greece, within the framework of ACS-AEI.

Results

31 students (19 females and 12 males), mean age of 26.2 ± 0.8 years, participated in the study. However, since two of the students completed only one of the three MIST-VR tasks, they were excluded. The three MIST-VR scores showed significant positive correlations to both the Pl variable in the automated video analysis of the PEG-transfer (RSquare 0.48, P < 0.0001; 0.34, P = 0.0009; 0.45, P < 0.0001, respectively) as well as to the Prtcl_tot variable in that same exercise (RSquare 0.42, P = 0.0002; 0.29, P = 0.0024; 0.45, P < 0.0001). However, the correlations were exclusively shown in the group with less PC gaming experience as well as in the female group.

Conclusions

Automated video analysis provides accurate results in line with those of the validated MIST-VR. We believe that a more frequent use of automated video analysis could provide an extended value to cost-efficient laparoscopic BlackBox training. However, since there are gender-specific as well as PC gaming experience differences, this should be taken in account regarding the value of automated video analysis.

Virtual reality-based assessment of basic laparoscopic skills using the Leap Motion controller

BACKGROUND

The majority of the current surgical simulators employ specialized sensory equipment for instrument tracking. The Leap Motion controller is a new device able to track linear objects with sub-millimeter accuracy. The aim of this study was to investigate the potential of a virtual reality (VR) simulator for assessment of basic laparoscopic skills, based on the low-cost Leap Motion controller.

METHODS

A simple interface was constructed to simulate the insertion point of the instruments into the abdominal cavity. The controller provided information about the position and orientation of the instruments. Custom tools were constructed to simulate the laparoscopic setup. Three basic VR tasks were developed: camera navigation (CN), instrument navigation (IN), and bimanual operation (BO). The experiments were carried out in two simulation centers: MPLSC (Athens, Greece) and CRESENT (Riyadh, Kingdom of Saudi Arabia). Two groups of surgeons (28 experts and 21 novices) participated in the study by performing the VR tasks. Skills assessment metrics included time, pathlength, and two task-specific errors. The face validity of the training scenarios was also investigated via a questionnaire completed by the participants.

RESULTS

Expert surgeons significantly outperformed novices in all assessment metrics for IN and BO (p < 0.05). For CN, a significant difference was found in one error metric (p < 0.05). The greatest difference between the performances of the two groups occurred for BO. Qualitative analysis of the instrument trajectory revealed that experts performed more delicate movements compared to novices. Subjects' ratings on the feedback questionnaire highlighted the training value of the system.

CONCLUSIONS

This study provides evidence regarding the potential use of the Leap Motion controller for assessment of basic laparoscopic skills. The proposed system allowed the evaluation of dexterity of the hand movements. Future work will involve comparison studies with validated simulators and development of advanced training scenarios on current Leap Motion controller.

DNA repair genes are selectively mutated in diffuse large B cell lymphomas

DNA repair mechanisms are fundamental for B cell development, which relies on the somatic diversification of the immunoglobulin genes by V(D)J recombination, somatic hypermutation, and class switch recombination. Their failure is postulated to promote genomic instability and malignant transformation in B cells. By performing targeted sequencing of 73 key DNA repair genes in 29 B cell lymphoma samples, somatic and germline mutations were identified in various DNA repair pathways, mainly in diffuse large B cell lymphomas (DLBCLs). Mutations in mismatch repair genes (EXO1, MSH2, and MSH6) were associated with microsatellite instability, increased number of somatic insertions/deletions, and altered mutation signatures in tumors. Somatic mutations in nonhomologous end-joining (NHEJ) genes (DCLRE1C/ARTEMIS, PRKDC/DNA-PKcs, XRCC5/KU80, and XRCC6/KU70) were identified in four DLBCL tumors and cytogenetic analyses revealed that translocations involving the immunoglobulin-heavy chain locus occurred exclusively in NHEJ-mutated samples. The novel mutation targets, CHEK2 and PARP1, were further screened in expanded DLBCL cohorts, and somatic as well as novel and rare germline mutations were identified in 8 and 5% of analyzed tumors, respectively. By correlating defects in a subset of DNA damage response and repair genes with genomic instability events in tumors, we propose that these genes play a role in DLBCL lymphomagenesis.

Epstein-Barr virus immortalization of human B-cells leads to stabilization of hypoxia-induced factor 1 alpha, congruent with the Warburg effect

BACKGROUND

Epstein-Barr virus (EBV) encodes six nuclear transformation-associated proteins that induce extensive changes in cellular gene expression and signaling and induce B-cell transformation. The role of HIF1A in EBV-induced B-cell immortalization has not been previously studied.

METHODS AND FINDINGS

Using Western blotting and Q-PCR, we found that HIF1A protein is stabilized in EBV-transformed lymphoblastoid cells. Western blotting, GST pulldown assays, and immunoprecipitation showed that EBV-encoded nuclear antigens EBNA-5 and EBNA-3 bind to prolylhydroxylases 1 and 2, respectively, thus inhibiting HIF1A hydroxylation and degradation. Immunostaining and Q-PCR showed that the stabilized HIF1A translocates to the nucleus, forms a heterodimer with ARNT, and transactivates several genes involved in aerobic glycolysis. Using biochemical assays and Q-PCR, we also found that lymphoblastoid cells produce high levels of lactate, lactate dehydrogenase and pyruvate.

CONCLUSIONS

Our data suggest that activation of the aerobic glycolytic pathway, corresponding to the Warburg effect, occurs in EBV-transformed lymphoblastoid cells, in contrast to mitogen-activated B-cells.

Reovirus-induced tenosynovitis in chickens the influence of age at infection

Groups of specific pathogen-free (SPF) light hybrid chickens were infected with an arthrotropic reovirus at 1 day old, or at 2, 4, 6 or 9 weeks of age. In each group, approximately 20 were infected orally and 6 via the footpad. For each age group clinical signs of tenosynovitis, gross and microscopic lesions in the legs, virus excretion in the faeces, virus persistence in the joints, and precipitin response to reovirus were observed over a period of 9 weeks post infection (p.i.). For both routes of infection an age-limited susceptibility was shown, the most serious effects, both in numbers of affected birds and severity of gross lesions including tendon rupture, being seen in the youngest group. Gross lesions were rarely seen after oral infection of 6- and 9-week-old chickens. Footpad inoculation of virus had a more severe effect overall, and extended the age susceptibility, mild leg swellings being seen in some birds infected at 6 and 9 weeks of age. After oral infection, higher virus titres in the faeces and a more prolonged persistence in the gut and hock joint were recorded in chicks infected at 1 day old compared with the other age groups. Also, compared with the older groups, a delayed precipitin response was found in those infected at 1 day old. Footpad inoculation provoked earlier virus replication in the gut and a more rapid precipitin response.