EpiDiP/NanoDiP: a versatile unsupervised machine learning edge computing platform for epigenomic tumour diagnostics

DNA methylation analysis based on supervised machine learning algorithms with static reference data, allowing diagnostic tumour typing with unprecedented precision, has quickly become a new standard of care. Whereas genome-wide diagnostic methylation profiling is mostly performed on microarrays, an increasing number of institutions additionally employ nanopore sequencing as a faster alternative. In addition, methylation-specific parallel sequencing can generate methylation and genomic copy number data. Given these diverse approaches to methylation profiling, to date, there is no single tool that allows (1) classification and interpretation of microarray, nanopore and parallel sequencing data, (2) direct control of nanopore sequencers, and (3) the integration of microarray-based methylation reference data. Furthermore, no software capable of entirely running in routine diagnostic laboratory environments lacking high-performance computing and network infrastructure exists. To overcome these shortcomings, we present EpiDiP/NanoDiP as an open-source DNA methylation and copy number profiling suite, which has been benchmarked against an established supervised machine learning approach using in-house routine diagnostics data obtained between 2019 and 2021. Running locally on portable, cost- and energy-saving system-on-chip as well as gpGPU-augmented edge computing devices, NanoDiP works in offline mode, ensuring data privacy. It does not require the rigid training data annotation of supervised approaches. Furthermore, NanoDiP is the core of our public, free-of-charge EpiDiP web service which enables comparative methylation data analysis against an extensive reference data collection. We envision this versatile platform as a useful resource not only for neuropathologists and surgical pathologists but also for the tumour epigenetics research community. In daily diagnostic routine, analysis of native, unfixed biopsies by NanoDiP delivers molecular tumour classification in an intraoperative time frame.

Proteome-based insights for IDH-mutant glioma classification

In this issue, Bader et al.¹ characterize the proteomes of diffuse glioma brain tumors by liquid chromatography mass spectrometry and classify isocitrate dehydrogenase (IDH)-mutant gliomas into two subtypes, which differ in oncogenic pathways and aerobic/anaerobic energy metabolism.

A prospective study of shared decision-making in brain tumor surgery

PURPOSE

Shared decision-making (SDM) is a key tenet of personalized care and is becoming an essential component of informed consent in an increasing number of countries. The aim of this study is to analyze patient and healthcare staff satisfaction with the SDM process before and after SDM was officially introduced as the standard of care. Decision grids are important tools in the SDM process, and we developed them for three different types of intracranial tumors.

METHODS

This prospective study was conducted in a high-volume neuro-oncological center on all consecutive eligible patients undergoing consideration of treatment for intracranial glioma and metastases. Twenty-two patients participated before and 74 after the introduction of SDM. Six and 5 staff members respectively participated in the analysis before and after team training and the introduction of SDM. The main outcome was patient and healthcare staff satisfaction with the SDM process.

RESULTS

Patients reported high satisfaction with the SDM process before (mean CollaboRATE score 26 of 27 points) and after (mean CollaboRATE score 26.3 of 27 points, p = 0.23) the introduction of SDM. Interestingly, staff attitude toward SDM improved significantly from 61.68 before to 90.95% after the introduction of SDM (p-value < 0.001). Decision grids that were developed for three different types of intracranial tumors are presented.

CONCLUSIONS

Team training in SDM and the introduction of techniques into daily practice can increase staff satisfaction with the SDM process. High levels of patient satisfaction were observed before, with a non-significant increase after the introduction of SDM. Decision grids are an important tool to facilitate the conveyance and understanding of complex information and to achieve SDM in daily clinical practice.

CNSC-20. PROTEOMIC ANALYSIS OF GLIOMA BIOPSIES SHOWS CONSISTENCY WITH GLIOMA GRADING

BACKGROUND

Glioma are currently classified according to integrated histopathologic and molecular genetic (WHO 2021 classification) as well as methylomic criteria (Capper 2018). However, little is known about proteomic profiling of these subgroups , which may reveal specific biomarkers and pathways potentially activated or inactivated. Material and

METHODS

Eighty-six glioma biopsy samples were prospectively collected from patients undergoing surgery at the University Hospital of Basel between 2017 and 2019. Samples were classified into seven distinct glioma subgroups based on integrated WHO 2016 and methylome profiling criteria. Proteins were extracted from fresh frozen samples devoid of necrosis/haemorrhage and processed for mass spectrometry analysis.

RESULTS

For each tumour sample, a total of 8’855 proteins were identified and quantified. 950 proteins were differentially expressed between at least two glioma subgroups. Strikingly, most significant differences in expression are related to tumor grading rather than to glioma subgroups. Proteins SSDH and GABT, involved in Gamma-aminobutyric acid (GABA) catabolism, show the strongest increase between low grade glioma (LGG) and high grade glioma (HGG), whereas S10AA and ANXA2, part of pathways involved in coagulation, cell adhesion and immune response, appear increased in HGG.

CONCLUSION

Tumor grading turns out to be dominant over genetic and epigenetic criteria for proteomic classification. Most significant protein level variations may represent potential glioma grade-specific therapeutic targets.

Integrated Molecular-Morphologic Meningioma Classification: A Multicenter Retrospective Analysis, Retrospectively and Prospectively Validated

PURPOSE

Meningiomas are the most frequent primary intracranial tumors. Patient outcome varies widely from benign to highly aggressive, ultimately fatal courses. Reliable identification of risk of progression for individual patients is of pivotal importance. However, only biomarkers for highly aggressive tumors are established (CDKN2A/B and TERT), whereas no molecularly based stratification exists for the broad spectrum of patients with low- and intermediate-risk meningioma.

METHODS

DNA methylation data and copy-number information were generated for 3,031 meningiomas (2,868 patients), and mutation data for 858 samples. DNA methylation subgroups, copy-number variations (CNVs), mutations, and WHO grading were analyzed. Prediction power for outcome was assessed in a retrospective cohort of 514 patients, validated on a retrospective cohort of 184, and on a prospective cohort of 287 multicenter cases.

RESULTS

Both CNV- and methylation family-based subgrouping independently resulted in increased prediction accuracy of risk of recurrence compared with the WHO classification (c-indexes WHO 2016, CNV, and methylation family 0.699, 0.706, and 0.721, respectively). Merging all risk stratification approaches into an integrated molecular-morphologic score resulted in further substantial increase in accuracy (c-index 0.744). This integrated score consistently provided superior accuracy in all three cohorts, significantly outperforming WHO grading (c-index difference P = .005). Besides the overall stratification advantage, the integrated score separates more precisely for risk of progression at the diagnostically challenging interface of WHO grade 1 and grade 2 tumors (hazard ratio 4.34 [2.48-7.57] and 3.34 [1.28-8.72] retrospective and prospective validation cohorts, respectively).

CONCLUSION

Merging these layers of histologic and molecular data into an integrated, three-tiered score significantly improves the precision in meningioma stratification. Implementation into diagnostic routine informs clinical decision making for patients with meningioma on the basis of robust outcome prediction.

PATH-39. INTEGRATED MOLECULAR-MORPHOLOGICAL MENINGIOMA CLASSIFICATION: A MULTICENTER RETROSPECTIVE ANALYSIS, RETRO- AND PROSPECTIVELY VALIDATED

PURPOSE

Meningiomas are the most frequent primary intracranial tumors. Patient outcome varies widely from cases with benign to highly aggressive, ultimately fatal courses. Reliable identification of risk of progression for the individual patient is of pivotal importance in clinical management. However, only biomarkers for highly aggressive tumors are established at present (CDKN2A/B and TERT), while no molecularly-based stratification exists for the broad spectrum of low- and intermediate-risk meningioma patients.

PATIENTS AND METHODS

DNA methylation data and copy-number information were generated for 3,031 meningiomas of 2,868 individual patients, with mutation data for 858 samples. DNA methylation subgroups, copy-number variations (CNV), mutations and WHO grading were comparatively analyzed. Prediction power for outcome of these parameters was assessed in an initial retrospective cohort of 514 patients, and validated on a retrospective cohort of 184, and on a prospective cohort of 287 multi-center cases, respectively.

RESULTS

Both CNV and methylation family- (MF)-based subgrouping independently resulted in an increase in prediction accuracy of risk of recurrence compared to the WHO classification (c-indexes WHO 2016, CNV, and MF 0.699, 0.706 and 0.721, respectively). Merging all independently powerful risk stratification approaches into an integrated molecular-morphological score resulted in a further, substantial increase in accuracy (c-index 0.744). This integrated score consistently provided superior accuracy in all three cohorts, significantly outperforming WHO grading (c-index difference p=0.005). Besides the overall stratification advantage, the integrated score separates more precisely for risk of progression at the diagnostically challenging interface of WHO grade 1 and grade 2 tumors (HR 4.56 [2.97;7.00], 4.34 [2.48;7.57] and 3.34 [1.28; 8.72] for discovery, retrospective, and prospective validation cohort, respectively).

CONCLUSIONS

Merging these layers of histological and molecular data into an integrated, three-tiered score significantly improves the precision in meningioma stratification. Implementation into diagnostic routine informs clinical decision-making for meningioma patients on the basis of robust outcome prediction.

Intraoperative ultrasound-guided compared to stereotactic navigated ventriculoperitoneal shunt placement: study protocol for a randomised controlled study

BACKGROUND

Ventriculoperitoneal shunt (VPS) placement is one of the most frequent neurosurgical procedures and the operation is performed in a highly standardised manner under maintenance of highest infection precautions. Short operation times are important since longer duration of surgery can increase the risk for VPS complications, especially infections. The position of the proximal ventricular catheter influences shunt functioning and survival. With freehand placement, rates of malpositioned VPS are still high. Several navigation techniques for improvement of shunt placement have been developed. Studies comparing these techniques are sparse. The aim of this study is to prospectively compare ultrasound (US) guided to stereotactic navigated shunt placement using optical tracking with the focus on operation time and efficiency.

METHODS

In this prospective randomised, single-centre, partially-blinded study, we will include all patients undergoing VPS placement in our clinic. The patients will be randomised into two groups, one group undergoing US-guided (US-G) and the other group stereotactic navigated VPS placement using optical tracking. The primary outcome will be the surgical intervention time. This time span consists of the surgical preparation time together with the operation time and is given in minutes. Secondary outcomes will be accuracy of catheter positioning, VPS dysfunction and need for revision surgery, total operation and anaesthesia times, and amount of intraoperative ventricular puncture attempts as well as complications, any morbidity and mortality.

DISCUSSION

To date, there is no prospective data available comparing these two navigation techniques. A randomised controlled study is urgently needed in order to provide class I evidence for the best possible surgical technique of this frequent surgery.

TRIAL REGISTRATION

Business Administration System for Ethical Committees (BASEC) 2019-02157, registered on 21 November 2019, https://www.kofam.ch/de/studienportal/suche/88135/studie/49552 ; clinicalTrials.gov: NCT04450797 , registered on 30 June 2020.

Ultrasound-Guided Insertion of the Ventricular Catheter in Ventriculoperitoneal Shunt Surgery: Evaluation of Accuracy and Feasibility in a Prospective Cohort

OBJECTIVE

 Ventriculoperitoneal shunt (VPS) placement is one of the most frequent neurosurgical procedures. The position of the proximal catheter is important for shunt survival. Shunt placement is done either without image guidance ("freehand") according to anatomical landmarks or by use of various image-guided techniques. Studies evaluating ultrasound-guided (US-G) VPS placement are sparse. We evaluate the accuracy and feasibility of US-G VPS placement, and compare it to freehand VPS placement.

METHODS

 We prospectively collected data of consecutive patients undergoing US-G VPS placement. Thereafter, the US cohort was compared with a cohort of patients in whom VPS was inserted using the freehand technique (freehand cohort). Primary outcome was accuracy of catheter positioning, and secondary outcomes were postoperative improvement in Evans' index (EI), rates of shunt dysfunction and revision surgery, perioperative complications, as well as operation, and anesthesia times.

RESULTS

 We included 15 patients undergoing US-G VPS insertion. Rates of optimally placed shunts were higher in the US cohort (67 vs. 49%, p = 0.28), whereas there were no malpositioned VPS (0%) in the US cohort, compared with 10 (5.8%) in the freehand cohort (p = 0.422). None of the factors in the univariate analysis showed significant association with nonoptimal (NOC) VPS placement in the US cohort. The mean EI improvement was significantly better in the US cohort than in the freehand cohort (0.043 vs. 0.014, p = 0.035).

CONCLUSION

 Based on our preliminary results, US-G VPS placement seems to be feasible, safe, and increases the rate of optimally placed catheters.

Effectiveness of a Chlorhexidine Dressing on Silver-coated External Ventricular Drain-associated Colonization and Infection: A Prospective Single-blinded Randomized Controlled Clinical Trial

Background

Observational studies have shown that dressings containing chlorhexidine gluconate (CHX) lower the incidence external ventricular drain (EVD)-associated infections (EVDAIs). This prospective, randomized controlled trial (RCT) studies the efficacy of CHX-containing dressings in reducing bacterial colonization.

Methods

In this RCT, patients aged ≥18 years undergoing emergency EVD placement were randomly given either a CHX-containing or an otherwise identical control dressing at the skin exit wound. The primary end-point was bacterial regrowth in cultured skin swab samples of the EVD exit wound. The secondary end-points were catheters processed by sonication, clinically diagnosed EVDAI and surgical treatment of hydrocephalus.

Results

From October 2013 to January 2016, a total of 57 patients were randomized to receive either a CHX or a control dressing (29 and 28 patients, respectively). Cutaneous bacterial regrowth at the EVD exit wound was significantly reduced over time (geometric mean ratio, 0.18; 95% confidence interval, .08-.42; P < .001). The incidence of colonized catheters was lower in the CHX group (5 of 28; 18%) than in the control group (10 of 27; 33%), with less microbial colonization on the subcutaneous portion. The infection rate was 4 of 28 (14%) in the CHX group, compared with 7 of 27 (26%) in the control group, with a substantially lower hydrocephalus treatment rate (7 of 28 [25%] vs 14 of 27 [52%], respectively).

Conclusion

Our data support the use of CHX dressings to reduce EVD exit site contamination, potentially reducing EVDAIs and permanent cerebrospinal fluid diversion procedures for hydrocephalus.

Clinical Trials Registration

NCT02078830.

4260Loss of Pnn in cardiomyocytes results in impairment of intercalated discs and arrhythmogenic cardiomyopathy in mice

Background

Pnn, a multiple functional protein that localizes within nucleus and in the cytoplasmic region of desmosome. Although recent studies have characterized the physiological role of nuclear Pnn in regulating pre-mRNA alternative splicing and gene transcription, the function of Pnn in desmosome, particularly in cardiomyocytes, remains unidentified.

Purpose and methods

In the present study, we applied an inducible cardiomyocyte-specific Pnn depletion mouse model (Myh6-CreERT2, Pnnflox/flox) to observe the impact of loss of Pnn on cardiac structure and function in adult mice.

Results

Six weeks after tamoxifen injection to induce cardiac Pnn depletion, the electrocardiographic abnormalities and decrease of left ventricular ejection fraction (LVEF) were observed. Histopathological examination showed that the proliferation of cardiac fibroblasts and expression of α-smooth muscle actin were increased with Pnn depletion, while the cell-cell connection among cardiomyocytes were impaired. In addition, cellular hypertrophy and decrease of capillary density were also found. Results from Immunofluorescent staining further showed that the distribution pattern of desmosomal proteins and adherent junctional proteins, including desmoglein, desmocollin, plakoglobin, plakophllin, desmoplakin and β-catenin were altered in the cardiomyocytes with Pnn depletion. Both desmosomal and adherent junctional proteins were translocated form cell-cell junction to cytoplasm, indicating the disruption of intercalated discs in Pnn-depleted cardiomyocytes. Microarray data also indicated that loss of cardiac Pnn regulated the mRNA expression of genes responsible for extracellular matrix-receptor interaction, ribosome, and integrin. In addition, expression levels of oxidative stress-associated proteins were significantly regulated by Pnn depletion.

Impairment of intercalated disc

Conclusion

Results from present study indicated that Pnn plays an essential role in the maintenance of intercalated disc integrity of cardiomyocytes, while cardiomyocyte-specific loss of Pnn leads to arrhythmogenic cardiomyopathy in mice.

Acknowledgement/Funding

Ministry of Science and Technology Taiwan, MOST-106-2320-B-182A-010-MY3

Regulation of glioma cell invasion by 3q26 gene products PIK3CA, SOX2 and OPA1

Diffuse gliomas progress by invading neighboring brain tissue to promote postoperative relapse. Transcription factor SOX2 is highly expressed in invasive gliomas and maps to chromosome region 3q26 together with the genes for PI3K/AKT signaling activator PIK3CA and effector molecules of mitochondria fusion and cell invasion, MFN1 and OPA1. Gene copy number analysis at 3q26 from 129 glioma patient biopsies revealed mutually exclusive SOX2 amplifications (26%) and OPA1 losses (19%). Both forced SOX2 expression and OPA1 inactivation increased LN319 glioma cell invasion in vitro and promoted cell dispersion in vivo in xenotransplanted D. rerio embryos. While PI3 kinase activity sustained SOX2 expression, pharmacological PI3K/AKT pathway inhibition decreased invasion and resulted in SOX2 nucleus-to-cytoplasm translocation in an mTORC1-independent manner. Chromatin immunoprecipitation and luciferase reporter gene assays together demonstrated that SOX2 trans-activates PIK3CA and OPA1. Thus, SOX2 activates PI3K/AKT signaling in a positive feedback loop, while OPA1 deletion is interpreted to counteract OPA1 trans-activation. Remarkably, neuroimaging of human gliomas with high SOX2 or low OPA1 genomic imbalances revealed significantly larger necrotic tumor zone volumes, corresponding to higher invasive capacities of tumors, while autologous necrotic cells are capable of inducing higher invasion in SOX2 overexpressing or OPA1 knocked-down relative to parental LN319. We thus propose necrosis volume as a surrogate marker for the assessment of glioma invasive potential. Whereas glioma invasion is activated by a PI3K/AKT-SOX2 loop, it is reduced by a cryptic invasion suppressor SOX2-OPA1 pathway. Thus, PI3K/AKT-SOX2 and mitochondria fission represent connected signaling networks regulating glioma invasion.

Intestinal IMINO transporter SIT1 is not expressed in human newborns

The expression of amino acid transporters in small intestine epithelia of human newborns has not been studied yet. It is further not known whether the maturation of imino acid (proline) transport is delayed as in the kidney proximal tubule. The possibility to obtain small intestinal tissue from patients undergoing surgery for jejunal or ileal atresia during their first days after birth was used to address these questions. As control, adult terminal ileum tissue was sampled during routine endoscopies. Gene expression of luminal imino and amino acid transporter SIT1 (SLC6A20) was approximately threefold lower in newborns versus adults. mRNA levels of all other luminal and basolateral amino acid transporters and accessory proteins tested were similar in newborn mucosa compared with adults. At the protein level, the major luminal neutral amino acid transporter B⁰AT1 (SLC6A19) and its accessory protein angiotensin-converting enzyme 2 were shown by immunofluorescence to be expressed similarly in newborns and in adults. SIT1 protein was not detectable in the small intestine of human newborns, in contrast to adults. The morphology of newborn intestinal mucosa proximal and distal to the obstruction was generally normal, but a decreased proliferation rate was visualized distally of the atresia by lower levels of the mitosis marker K_i-67. The mRNA level of the 13 tested amino acid transporters and accessory proteins was nonetheless similar, suggesting that the intestinal obstruction and interruption of amniotic fluid passage through the small intestinal lumen did not affect amino acid transporter expression. NEW & NOTEWORTHY System IMINO transporter SIT1 is not expressed in the small intestine of human newborns. This new finding resembles the situation in the proximal kidney tubule leading to iminoglycinuria. Lack of amniotic fluid passage in small intestinal atresia does not affect amino acid transporter expression distal to intestinal occlusion.

Preoperative Two-Dimensional Size of Glioblastoma is Associated with Patient Survival

BACKGROUND

Although tumor size affects survival of patients with lower-grade glioma, a prognostic effect on patients with glioblastoma remains to be established.

METHODS

We performed a retrospective analysis of 61 patients using volumetric data of tumor compartments of 61 patients obtained by preoperative magnetic resonance images using the visual ABC/2 method. Preoperative enhancing, nonenhancing, necrosis, and edema volume, the preoperative tumor area (TA) as a product of the 2 largest tumor diameters perpendicular to each other on axial T1-weighted postcontrast images, as well as postoperative enhancing residual volumes, were measured. Multivariable Cox proportional hazard models were used to associate these parameters with overall survival, adjusting for potential confounders.

RESULTS

The median preoperative enhancing tumor volume was 18.2 mL (interquartile range, 8.2-41.7 mL); the median remnant tumor volume was 1.3% (interquartile range, 0.0%-42.9%). During follow-up, 59 patients (92%) died; median survival time and median follow-up time were both 404 days. We found a statistically significant multiplicative effect of TA on survival: the hazard ratio (HR) was increased by 1.096 per unit increase of 200 mm² (95% confidence interval [CI], 1.027-1.170; P < 0.01). The effect of remnant tumor on HR increased multiplicatively by 1.013 (95% CI, 1.001-1.026; P = 0.04) per unit increase of 1 log (day) and 1% in tumor remnant. HR associated with age at surgery increased by 1.503 per 5 years of age (95% CI, 1.243-1.817; P < 0.01).

CONCLUSIONS

Preoperative TA proved to be the only glioblastoma size parameter that affects patient survival.

Cast wedging: a systematic review of the present evidence

PURPOSE

The objective of this systematic review was to summarise the outcome after cast wedging due to loss of angulation in conservative fracture treatment of children's fractures.

METHODS

Electronic searches were performed using MEDLINE, PubMed, OVID, CENTRAL and EMBASE without language restrictions.

RESULTS

Three studies comprising 316 patients (210 radius, 52 forearm/both bone forearm fractures and 54 tibia fractures) were included in the present analysis. Cast wedge failures occurred in 14 of 316 (4.4%) patients. Three patients (0.9%) needed surgical fixation and 11 patients (3.4%) ended up with a healed deformity. Furthermore, eight of 316 (1.8%) patients needed remanipulation and cast change.

CONCLUSION

Cast wedging reflects a reliable treatment option for secondary displaced long-bone paediatric fractures.

Preoperative and Postoperative Factors and Laboratory Values Predicting Outcome in Patients Undergoing Lumbar Fusion Surgery

OBJECTIVE

To determine whether complications in lumbar fusion surgery could be estimated from patient factors and perioperative laboratory values. In addition, risk scores for detection of patients prone to complications were defined.

METHODS

We retrospectively collected data of patients undergoing lumbar fusion surgery between 2013 and 2015. The patients were divided into group A (no complications) and group B (systemic and infectious complications within 30 days postoperatively). Patient-related factors and levels of perioperative laboratory values were compared between the groups and analyzed for possible impact on complications and length of stay (LOS) in the hospital.

RESULTS

Data of 132 consecutive patients (74 women [56.1%]; median age, 68.5 years) were analyzed. Postoperative complications occurred in 29.5%. Higher postoperative creatine kinase (CK) and C-reactive protein and lower postoperative hemoglobin and thrombocyte values, as well as higher differences between preoperative and postoperative CK, C-reactive protein, and hemoglobin values were associated with postoperative complications. Among others, the combinations of advanced age and elevated body mass index (P = 0.0062, odds ratio: 3.018), or advanced age, elevated body mass index, and postoperative CK >166 U/L (P = 0.0016, odds ratio: 3.637) revealed patients with a threefold risk for complications. The combination of advanced age, American Society of Anesthesiologists score >2, and preoperative hemoglobin <12.9 g/dL was associated with a LOS of 20.3 versus 11 days (P = 0.01).

CONCLUSIONS

Patients with postoperative complications and extended LOS seem to show significant differences in various perioperative laboratory values and patient factors. Perioperative risk assessments using cut-off values and risk scores may help identify patients prone to complications and extended resource use.

IDH mutation is associated with higher risk of malignant transformation in low-grade glioma

Acquisition of IDH1 or IDH2 mutation (IDHmut) is among the earliest genetic events that take place in the development of most low-grade glioma (LGG). IDHmut has been associated with longer overall patient survival. However, its impact on malignant transformation (MT) remains to be defined. A collection of 210 archived adult LGG previously stratified by IDHmut, MGMT methylation (MGMTmet), 1p/19q combined loss of heterozygosity (1p19qloh) and TP53 immunopositivity (TP53pos) status was analyzed. We used multistate models to assess MT-free survival, considering one initial, one transient (MT), and one absorbing state (death). Missing explanatory variables were multiply imputed. Overall, although associated with a lower risk of death (HR(DEATH) = 0.35, P = 0.0023), IDHmut had a non-significantly higher risk of MT (HR(MT) = 1.84; P = 0.1683) compared to IDH wild type (IDHwt). The double combination of IDHmut and MGMTmet and the triple combination of IDHmut, MGMTmet and 1p/19qloh, despite significantly lower hazards for death (HR(DEATH) versus IDHwt: 0.35, P = 0.0194 and 0.15, P = 0.0008, respectively), had non-significantly different hazards for MT. Conversely, the triple combination of IDHmut/MGMTmet/TP53pos, with a non-significantly different hazard for death, had a significantly higher hazard for MT than IDHwt (HR(MT) versus IDHwt: 2.83; P = 0.0452). Although IDHmut status is associated with longer overall patient survival, all IDHmut/MGMTmet subsets consistently showed higher risks of MT than of death, compared to IDHwt LGG. This supports the findings that molecular events relevant to IDH mutations impact early glioma development prior to malignant transformation.

Management of Incidental Dural Tear During Lumbar Spine Surgery. To Suture or Not to Suture?

OBJECTIVE

Incidental durotomy (ID) during lumbar spine surgery is a frequent complication of growing clinical relevance as the number and complexity of spinal procedures increases. Yet, there is still a lack of guidelines for the treatment of ID with a large heterogeneity of established surgical techniques. The aim of this study was to investigate the efficacy of dural suturing in patients having ID during degenerative lumbar spine surgery, compared with other dural closure techniques.

METHODS

Of 1173 consecutive patients undergoing degenerative lumbar spine surgery from July 2013 to March 2015, in 64 (5.4%) patients 69 (5.8%) IDs occurred. The patients were divided into 3 groups depending on the dural closure technique used: group A, sole dural suture (n = 12, 19%); group B, patch only (TachoSil and/or muscle and/or fat) (n = 22, 32%); group C, dural suture in combination with a patch (n = 34, 49%). The primary end point was revision surgery caused by complications of cerebrospinal fluid leakage after 6 weeks. The secondary end points were operation time and hospitalization time, as well as surgical morbidity.

RESULTS

The 3 groups showed no significant difference in rates of revision surgery (group A: n = 1, 1.4%; group B: n = 4, 5.8%; group C: n = 3; 4.3%; P = 0.5). Furthermore, no significant difference for hospitalization time, operation time, and clinical outcome was found. Extent of ID, American Society of Anesthesiology score, postoperative immobilization, and insertion of a drainage tube were not associated with higher rates of revision surgery. Applying suction once a drainage tube was placed was found to be a significant risk factor for revision surgery (P = 0.003). Furthermore, patients undergoing revision surgery had a significantly higher body mass index (33 kg/m(2) vs. 26.37 kg/m(2); P = 0.006; odds ratio 1.252; P = 0.004).

CONCLUSIONS

Based on our results, the dural closure technique after ID does not seem to influence revision surgery rates due to cerebrospinal fluid leakage and its complications. Further prospective randomized studies are needed to confirm our results.

High salt exacerbates programmed hypertension in maternal fructose-fed male offspring

BACKGROUND AND AIMS

Consumption of food and drinks containing high fructose (HF), which is associated with hypertension, is increasing steeply. Moreover, increased salt intake significantly increases hypertension risk. We examined whether maternal HF and postnatal high salt (HS) intake had synergistic effects on blood pressure (BP) elevation in adult offspring and determined the underlying mechanisms.

METHODS AND RESULTS

Pregnant Sprague-Dawley rats received regular chow or chow supplemented with 60% fructose during the entire pregnancy and lactation periods. Half of the male offspring received 1% NaCl in drinking water from weaning to 3 months of age. Male offspring were assigned to 4 groups (control, HF, HS, and HF + HS) and were sacrificed at 12 weeks of age. Offspring in HF and HS groups developed hypertension, indicating that HF and HS synergistically increased BP. Postnatal HS intake increased Ace expression and decreased Agtr1b and Mas1 expression in the kidneys. Renal mRNA levels of Ace and Agtr1a were significantly higher in HF + HS group than in control group. Renal levels of Na-K-2Cl cotransporter, type 3 sodium hydrogen exchanger, and Na(+)/Cl(-) cotransporter were higher in HS and HF + HS groups than in control group.

CONCLUSION

Postnatal HS intake exacerbated prenatal HF-induced programmed hypertension. HF and HS induced programmed hypertension by differentially inducing renin-angiotensin system and sodium transporters in the kidneys. Better understanding of the effect of the relationship between HF and HS on hypertension development will help prevent hypertension in mothers and children exposed to HF and HS.

Langer-Giedion syndrome associated with congenital dural arterio-venous fistula

Langer-Giedion syndrome (LGS) is a rare disease caused by deletion of chromosome 8q23.3-q24.11. Clinical manifestations include among others multiple exostoses, short stature, intellectual disability, and typical facial dysmorphism. Dural arterio-venous shunts (DAVS) in the pediatric age are rare lesions, which have been classified into three types: dural sinus malformations (DSM), infantile type DAVS (IDAVS), and adult type DAVS (ADAVS). We report a case of a patient with a known LGS who was diagnosed with complex intracranial dural AV fistula at the age of 20. An association between LGS and intracranial dural AV fistulas has to our knowledge never been reported before.

Reliability and application variability of a commercially available infrared videonystagmography unit

PURPOSE

Nystagmus is a condition of involuntary eye movement. The causes for nystagmus may be congenital, idiopathic, or acquired. Considerable debate exists on the therapeutic potential of various surgical techniques. Currently, there are neither standardized protocols nor devices to record quantitative data on patients with clinical nystagmus undergoing various procedures at multiple centers to facilitate randomized prospective clinical trials.

METHODS

The authors evaluated the reliability and variability of a commercially available infrared videonystagmography unit by recording eye movement waveforms elicited from normal volunteers (n = 117, 13 patients, 9 trials) by different examiners (A, B, and C). Five movement characteristics were examined, including saccadic latency, velocity and precision, and pursuit gain and velocity.

RESULTS

The overall test/retest variability was low, where the median coefficient of variation of the three testers for all five eye movement categories was less than 15%, and less than 10% of the coefficients of variation calculated were more than 20%. However, there was a significant difference in interobserver variability for all outcomes, except saccade latency.

CONCLUSIONS

The between-tester analysis was found to have greater variability than the test/retest reliability analysis. Future studies at multiple sites using videonystagmography measurements should aim to have each patient repeatedly tested by the same tester. In anticipation of multicenter, randomized, prospective clinical trials of surgical procedures for nystagmus, standardized protocols for nystagmographic data collection and analysis must be validated both within and among participating centers.

IDH/MGMT-driven molecular classification of low-grade glioma is a strong predictor for long-term survival

BACKGROUND

Low-grade gliomas (LGGs) are rare brain neoplasms, with survival spanning up to a few decades. Thus, accurate evaluations on how biomarkers impact survival among patients with LGG require long-term studies on samples prospectively collected over a long period.

METHODS

The 210 adult LGGs collected in our databank were screened for IDH1 and IDH2 mutations (IDHmut), MGMT gene promoter methylation (MGMTmet), 1p/19q loss of heterozygosity (1p19qloh), and nuclear TP53 immunopositivity (TP53pos). Multivariate survival analyses with multiple imputation of missing data were performed using either histopathology or molecular markers. Both models were compared using Akaike's information criterion (AIC). The molecular model was reduced by stepwise model selection to filter out the most critical predictors. A third model was generated to assess for various marker combinations.

RESULTS

Molecular parameters were better survival predictors than histology (ΔAIC = 12.5, P< .001). Forty-five percent of studied patients died. MGMTmet was positively associated with IDHmut (P< .001). In the molecular model with marker combinations, IDHmut/MGMTmet combined status had a favorable impact on overall survival, compared with IDHwt (hazard ratio [HR] = 0.33, P< .01), and even more so the triple combination, IDHmut/MGMTmet/1p19qloh (HR = 0.18, P< .001). Furthermore, IDHmut/MGMTmet/TP53pos triple combination was a significant risk factor for malignant transformation (HR = 2.75, P< .05).

CONCLUSION

By integrating networks of activated molecular glioma pathways, the model based on genotype better predicts prognosis than histology and, therefore, provides a more reliable tool for standardizing future treatment strategies.

Nonviolent elaborate behaviors may also occur in REM sleep behavior disorder

OBJECTIVE

To document unusual, nonviolent behaviors during REM sleep behavior disorder (RBD) and evaluate their frequency in Parkinson disease (PD).

BACKGROUND

Most behaviors previously described during RBD mimic attacks, suggesting they proceed from archaic defense generators in the brainstem. Feeding, drinking, sexual behaviors, urination, and defecation have not been documented yet in RBD.

METHODS

We collected 24 cases of nonviolent behaviors during idiopathic and symptomatic RBD (narcolepsy, dementia with Lewy bodies, PD), reported or observed in videopolysomnography. The frequency of violent and nonviolent behaviors during RBD was evaluated by face to face interview of patients and their cosleepers in a prospective series of 100 patients with PD.

RESULTS

Incidental cases of nonviolent behaviors during RBD included masturbating-like behavior and coitus-like pelvic thrusting, mimicking eating and drinking, urinating and defecating, displaying pleasant behaviors (laughing, singing, dancing, whistling, smoking a fictive cigarette, clapping and gesturing "thumbs up"), greeting, flying, building a stair, dealing textiles, inspecting the army, searching a treasure, and giving lessons. Speeches were mumbled or contained logical sentences with normal prosody. In PD with RBD (n = 60), 18% of patients displayed nonviolent behaviors. In this series (but not in incidental cases), all RBD patients with nonviolent behaviors also showed violent behaviors.

CONCLUSIONS

Although they are less frequent than violent behaviors, nonviolent behaviors during REM sleep behavior disorder (RBD) fill a large spectrum including learned speeches and culture-specific behaviors, suggesting they proceed from the cortex activation. Sexual behaviors during RBD may expose patients and cosleepers to forensic consequences.

Na+-H+ exchanger 3 (NHE3) is present in lipid rafts in the rabbit ileal brush border: a role for rafts in trafficking and rapid stimulation of NHE3

1. Rabbit ileal Na+-absorbing cell Na+-H+ exchanger 3 (NHE3) was shown to exist in three pools in the brush border (BB), including a population in lipid rafts. Approximately 50% of BB NHE3 was associated with Triton X-100-soluble fractions and the other approximately 50% with Triton X-100-insoluble fractions; approximately 33% of the detergent-insoluble NHE3 was present in cholesterol-enriched lipid microdomains (rafts). 2. The raft pool of NHE3 was involved in the stimulation of BB NHE3 activity with epidermal growth factor (EGF). Both EGF and clonidine treatments were associated with a rapid increase in the total amount of BB NHE3. This EGF- and clonidine-induced increase of BB NHE3 was associated with an increase in the raft pool of NHE3 and to a smaller extent with an increase in the total detergent-insoluble fraction, but there was no change in the detergent-soluble pool. In agreement with the rapid increase in the amount of NHE3 in the BB, EGF also caused a rapid stimulation of BB Na+-H+ exchange activity. 3. Disrupting rafts by removal of cholesterol with methyl-beta-cyclodextrin (MbetaCD) or destabilizing the actin cytoskeleton with cytochalasin D decreased the amount of NHE3 in early endosomes isolated by OptiPrep gradient fractionation. Specifically, NHE3 was shown to associate with endosomal vesicles immunoisolated by anti-EEA1 (early endosomal autoantigen 1) antibody-coated magnetic beads and the endosome-associated NHE3 was decreased by cytochalasin D and MbetaCD treatment. 4. We conclude that: (i) a pool of ileal BB NHE3 exists in lipid rafts; (ii) EGF and clonidine increase the amount of BB NHE3; (iii) lipid rafts and to a lesser extent, the cytoskeleton, but not the detergent-soluble NHE3 pool, are involved in the EGF- and clonidine-induced acute increase in amount of BB NHE3; (iv) lipid rafts and the actin cytoskeleton play important roles in the basal endocytosis of BB NHE3.

Extraordinary features in the Chlamydomonas reinhardtii chloroplast genome: (1). rps2 as part of a large open reading frame; (2). A C. reinhardtii specific repeat sequence

We have determined the DNA sequence of the 3574-bp chloroplast DNA fragment of Chlamydomonas reinhardtii formed by the overlap of BamHI fragment 3 and EcoRI fragment 5. This sequence encodes most of rps18 and orf570, an unidentified open reading frame that contains a 150 amino acid domain with high homology to the N-terminal part of 30 S ribosomal protein S2 of other chloroplast, cyanobacterial and bacterial genomes. Between these two sequences lies a highly repetitive sequence element of 500 bp, that is composed of multiple direct and inverted repeat sequences that occur in rearranged, but highly conserved form in at least 36 locations in the C. reinhardtii chloroplast genome. Among the conserved repeat sequences in the C. reinhardtii chloroplast genome we identified the borders of the inverted repeats near atpB and rps4. This might indicate that the conserved sequence elements are remainders of gene rearrangements in the chloroplast genome that occurred by relocations of the inverted repeats.

The C. reinhardtii CF1 with the mutation betaT168S has high ATPase activity

We have generated the mutation T168S in the beta subunit of the chloroplast ATP synthase complex of Chlamydomonas reinhardtii by site directed mutagenesis and chloroplast transformation. CF1 and the alpha3beta3gamma complex of this mutant strain were isolated and their enzymatic activities were characterized and compared to those of the corresponding wild type complexes. Without activation the mutant CF1 exhibits MgATPase activity with at least 10 times higher rates than the wild type enzyme. The MgATPase activity could be stimulated to some extent by methanol, but less by ethanol and octylglucoside. The alpha3beta3gamma complex had an even higher MgATPase activity, which was only slightly enhanced by ethanol or methanol. The ATPase activities of the mutant complexes, like those of the wild type complexes, displayed a sharp concentration optimum for Mg2+. Free ADP inhibited neither the mutant nor the wild type ATPase significantly. Azide, which strongly inhibited the ATPase activity of the wild type enzyme, inhibited the mutant enzyme only at an about 30 times higher concentration suggesting that the mutation T168S prevents trapping of a tightly bound MgADP by a catalytic site that regulates chloroplast ATPase activity. The mutant cells grew photoautotrophically at a growth rate of about 50%. Similar to the wild type the cells survived on minimal medium in the dark. Under heterotrophic conditions with acetate as energy and carbon source the mutant cells grew much faster than the wild type cells, but the chlorophyll content per cell decreased dramatically.

Catalytic properties and sensitivity to tentoxin of Chlamydomonas reinhardtii ATP synthases changed in codon 83 of atpB by site-directed mutagenesis

The participation of the amino acid beta83 in determining the sensitivity of chloroplast ATP synthases to tentoxin was reported previously. We have changed codon 83 of the Chlamydomonas reinhardtii atpB gene by site-directed mutagenesis to further examine the role of this amino acid in the response of the ATP synthase to tentoxin and in the mechanism of ATP synthesis and hydrolysis. Amino acid beta83 was changed from Glu to Asp (betaE83D) and to Lys (betaE83K), and the highly conserved tetrapeptide betaT82-E83-G84-L85 (DeltaTEGL) was deleted. Mutant strains were produced by particle gun transformation of atpB deletion mutants cw15DeltaatpB and FUD50 with the mutated atpB genes. The transformants containing the betaE83D and betaE83K mutant genes grew well photoautotrophically. The DeltaTEGL transformant did not grow photoautotrophically, and no CF1 subunits were detected by immunostaining of Western blots using CF1 specific antibodies. The rates of ATP synthesis at clamped DeltapH with thylakoids isolated from cw15 and the two mutants, betaE83D and betaE83K, were similar. However, only the phosphorylation activity of the mutant betaE83D was inhibited by tentoxin with 50% inhibition attained at 4 microM. These results confirm that amino acid beta83 is critical in determining the response of ATP synthase to tentoxin. The rates of the latent Mg-ATPase activity of the CF1s isolated from cw15, betaE83D, and betaE83K were similar and could be enhanced by heat, alcohols, and octylglucoside. As in the case of the membrane-bound enzyme, only CF1 from the betaE83D mutant was sensitive to tentoxin. A lower alcohol concentration was required for optimal stimulation of the ATPase of the betaE83K-CF1 than that of CF1 from the other two strains. Moreover, the optimal activity of the betaE83K-CF1 was also lower. These results suggest that introduction of an amino acid with a positively charged side chain in position 83 in the "crown" domain affects the active conformation of the CF1-ATPase.

A large open reading frame (orf1995) in the chloroplast DNA of Chlamydomonas reinhardtii encodes an essential protein

An open reading frame potentially encoding a protein of 1995 amino acids (orf1995) has been found in the chloroplast genome of the green alga Chlamydomonas reinhardtii. Besides having a short hydrophobic N-terminal domain with five putative transmembrane helices, the predicted orf1995 product is highly basic. orf1995 might be a homologue of the ycf1 gene in land plants, whose function has not yet been determined. Mutants of C. reinhardtii transformed with a disruption of orf1995 remain heteroplasmic for the wild-type and disrupted alleles of this gene, indicating that the orf1995 product is essential for cell survival.