PATH-33. “GENETIC AND EPIGENETIC PROFILING IDENTIFIES TWO DISTINCT CLASSES OF SPINAL MENINGIOMAS”

BACKGROUND

Spinal meningiomas account for 1.2-12 % of all meningiomas and 25-45 % of all spinal tumours. 20 % of intracranial, but only 4.6 % of spinal meningiomas recur requiring additional treatment. Whereas the classification of intracranial meningiomas has evolved considerably in recent years and uses genetic and epigenetic parameters, the classification of spinal meningiomas is based solely on histopathological findings. By embedding epi-/genetic features, the prognosis of intracranial meningiomas could be significantly improved, which is still lacking for spinal meningiomas. In our work, we integrated genetic and epigenetic parameters into the classification of spinal meningiomas.

METHODS

We performed epi-/genetic profiling of 50 spinal meningiomas. 497 intracranial meningiomas served as a reference cohort. Copy number variations (CNV) were inferred from the methylation data. Principal component (PCA) and t-SNE analysis were conducted. Clinical and histopathological parameters (location, size, recurrence, WHO°, pathological subtype) were correlated with methylation signatures using the DKFZ brain tumour classifier.

RESULTS

The methylation signature of spinal meningiomas matched to that of intracranial meningiomas (50/50), although meningioma subgroup assignment was achieved in only 13/50 cases. PCA and t-SNE analysis showed that most spinal meningiomas separate from cranial meningiomas and form two distinct clusters. Cluster 1 matched the methylation class ben-2, while cases in cluster 2 were heterogenous and had a low MSC score. Cases of cluster 1 were located in the upper spine, are more common in males and had an AKT1E17K mutation. NF2 mutations were found mainly in the second cluster, in line with a chr.22 q loss. Interestingly 4 tumors did not associate with the two spinal meningioma clusters and had a particular higher recurrence rate.

CONCLUSION

Genetic and epigenetic profiling of spinal meningiomas identifies two distinct classes of spinal meningiomas, which may allow an improved prognosis that could lead to a better guidance for adjuvant therapy.

BIOM-09. MULTIPLEX ANALYSIS OF CSF EXTRACELLULAR VESICLES OF INTRASPINAL TUMORS

BACKGROUND: Extracellular vesicles (EVs) play an important role in cell-cell communication in different types of tumors, carrying multiple layers of biological functional molecules, including proteins, RNA, DNA and lipids. We previously demonstrated that extracellular vesicles (EV) from central nervous system tumors reflect the molecular subtype of the original tumor and mediate an exchange of pro-oncogenic signals. Their implication as biomarkers in tumor disease is under current investigation. It is unclear, however, to what extent cerebrospinal fluid (CSF) EVs from intraspinal tumors are utilizable for diagnostical purposes and how their marker profiles overlap with EVs derived from non tumorous EVs. We analyzed CSF EVs of intraspinal tumors to define CSF EV profiles that allow tumor subtype classification. METHODS: EVs were isolated from CSF of patients suffering from intraspinal meningioma (n=5), ependymoma (n=7) and neurinoma (n=5). Patients suffering from normal pressure hydrocephalus were used as controls (n=5). EVs were analyzed by multiplex bead based assay, immunoblotting, electron microscopy and NTA. RESULTS: CSF EVs were 97.21 ± 3.37nm (intraspinal tumor patients) and 101.6 ± 3.68nm (controls) in sizes and showed vesicular structures by electron microscopy. Particle number were not significantly different between both groups (p = 0.103). Using our 37 protein mutliplex EV profiling kit we found 29 proteins to be expressed in a sufficient manner on CSF EVs. CSF EVs of intraspinal meningioma showed elevated CD62P, HLA-DR, CD40, CD42a and CD45 expression levels, while ependymoma showed decreased levels of CD9, CD63, CD81, whereas neurinomas had elevated levels of SSEA-3 and CD25. CONCLUSION: This is the first comprehensive analysis of CSF EV of intraspinal tumor patients. CSF EV display distinct subpopulations that may allow tumor classification and long-term surveillance. However as tumor-specific EVs may be rare, there is still the need to identify markers that can enrich tumor-specific EVs for molecular profiling.

Use of a culture-independent on-farm algorithm to guide the use of selective dry-cow antibiotic therapy

An algorithm using only computer-based records to guide selective dry-cow therapy was evaluated at a New York State dairy farm via a randomized field trial. DairyComp 305 (Valley Ag Software, Tulare, CA) and Dairy Herd Improvement Association test-day data were used to identify cows as low risk (cows that might not benefit from dry-cow antibiotics) or high risk (cows that will likely benefit). Low-risk cows were those that had all of the following: somatic cell count (SCC) ≤200,000 cells/mL at last test, an average SCC ≤200,000 cells/mL over the last 3 tests, no signs of clinical mastitis at dry-off, and no more than 1 clinical mastitis event in the current lactation. Low-risk cows were randomly assigned to receive intramammary antibiotics and external teat sealant (ABXTS) or external teat sealant only (TS) at dry-off. Using pre-dry-off and postcalving quarter-level culture results, low-risk quarters were assessed for microbiological cure risk and new infection risk. Groups were also assessed for differences in first-test milk yield and linear scores, individual milk weights for the first 30 d, and culling and mastitis events before 30 d in milk. A total of 304 cows and 1,040 quarters in the ABXTS group and 307 cows and 1,058 quarters in the TS group were enrolled. Among cows to be dried, the proportion of cows that met low-risk criteria was 64% (n = 611/953). Of cultures eligible for bacteriological cure analysis (n = 171), 93% of ABXTS cured, whereas 88% of TS cured. Of the non-cures, 95% were contributed by the minor pathogens coagulase-negative staphylococci (n = 19/20). These organisms also accounted for 57.5% of new infections (n = 77/134). We found no statistical differences between treatment groups for new infection risk (TS = 7.3% quarters experiencing new infections; ABXTS = 5.5%), milk production (ABXTS = 40.5 kg; TS = 41.2 kg), linear scores (ABXTS = 2.5; TS = 2.7), culling events (ABXTS, n = 18; TS, n = 15), or clinical mastitis events (ABXTS, n = 9; TS, n = 5). Results suggest that the algorithm used decreased dry-cow antibiotic use by approximately 60% without adversely affecting production or health outcomes.

Incomplete tumour control following DNA vaccination against rat gliomas expressing a model antigen

Background

Vaccination against tumour-associated antigens is one approach to elicit anti-tumour responses. We investigated the effect of polynucleotide (DNA) vaccination using a model antigen (E. coli lacZ) in a syngeneic gliosarcoma model (9L).

Methods

Fisher 344 rats were vaccinated thrice by intramuscular injection of a lacZ-encoding or a control plasmid in weekly intervals. One week after the last vaccination, lacZ-expressing 9L cells were implanted into the striatum.

Results

After 3 weeks, in lacZ-vaccinated animals the tumours were significantly smaller than in control-vaccinated animals. In cytotoxic T cell assays lysis rates of >50 % could only be observed in a few of the lacZ-vaccinated animals. This response was directed against lacZ-expressing and parental 9L cells but not against syngeneic MADB 106 adenocarcinoma cells. In Elispot assays interferon-γ production was observed upon stimulation with 9LlacZ and 9L wild-type but not MADB 106 cells. This response was higher for lacZ-immunized animals. All animals revealed dense infiltrates with CD8+ lymphocytes and, to a lesser extent, with NK cells. CD25-staining indicated cells possibly associated with the maintenance of peripheral tolerance to self-antigens. All tumours were densely infiltrated by microglia consisting mostly of ramified cells. Only focal accumulation of macrophage-like cells expressing ED1, a marker for phagocytic activity, was observed.

Conclusion

Prophylactic DNA vaccination resulted in effective but incomplete suppression of brain tumour formation. Mechanisms other than cytotoxic T cell responses as measured in the generally used in vitro assays appear to play a role in tumour suppression.

Safety and feasibility in highly concentrated contrast material power injections for CT-perfusion studies of the brain using central venous catheters

INTRODUCTION

CT perfusion studies play an important role in the early detection as well as in therapy monitoring of vasospasm after subarachnoid hemorrhage. High-flow injections via central venous catheters are not recommended but may sometimes be the only possibility to obtain high-quality images.

MATERIALS AND METHODS

We retrospectively analyzed our data for CT perfusions performed with power injection of contrast material with an iodine concentration of 400mg/ml via the distal 16G lumen of the Arrow three and five lumen central venous catheter with preset flow rates of 5ml/s.

RESULTS

104 examinations with central venous catheters were evaluated (67 with five lumen and 37 with three lumen). No complications were observed. Mean flow rates were 4.4±0.5ml/s using the three lumen catheter and 4.6±0.6ml/s using the five lumen catheter respectively. The mean injection pressure measured by the power injector was 200.7±17.5psi for the three lumen central venous catheter and 194.5±6.5psi for the five lumen catheter, respectively.

CONCLUSION

Following a strict safety protocol there were no complications associated with power injections of contrast material containing 400mg iodine/ml with preset flow rates up to 5ml/s via the distal 16G lumen of the Arrow multi-lumen central venous catheter. However, since power-injections are off-label use with Arrow central venous catheters, this procedure cannot be recommended until potential safety hazards have been ruled out by the manufacturer.

A multimodal concept in patients after severe aneurysmal subarachnoid hemorrhage: results of a controlled single centre prospective randomized multimodal phase I/II trial on cerebral vasospasm

OBJECTIVE

Recent publications suggest that a combination of head-shaking and cisternal irrigation might reduce symptomatic cerebral vasospasm after subarachnoid hemorrhage (SAH). The present clinical prospective randomized phase I/II study was initiated in order to analyze the prophylactic effect of intracisternal lysis in combination with kinetic treatment followed by intrathecal nimodipine lavage.

METHODS

Twenty patients with aneurysmal SAH, WFNS grade 2 to 5 (GCS 13-3) and Fisher grade 3 or 4 were included in this prospective randomized study which had been approved by the local Ethics Research Committee. Following insertion of a ventricular drain, securing of the aneurysm by a microsurgical or endovascular route and the insertion of two lumbar catheters, intracisternal lysis with urokinase 120 000 IU/d was performed for 48 h in the patients of the study group. Intrathecal pressure was monitored by the second lumbar catheter. After intracisternal lysis, intrathecal nimodipine lavage was applied for 7 d. For comatose patients kinetic head-rotation was also performed. Vasospasm was clinically identified with a focus on delayed neurological deficits (DINDs) by daily transcranial Doppler (TCD), computerized tomography (CT), perfusion CT (pCT) and cerebral angiography (DSA).

RESULTS

There was no DIND in the study group among the patients who were awake, while two DINDs occurred in the control group. The pooled TCD flow velocities over an average period of 14 d revealed no statistically significant difference between the groups. Vasospasm-related infarction on CT was seen in two patients of the control group. Evident vasospasm on DSA appeared in three patients of the study group compared with 7 patients in the control group. Moreover there was a neurological improvement in the study population as measured by mRS at 3-month follow-up (P=0.266). In two consecutive patients randomized to the study group a paresis of the lower extremities of unknown origin occurred. As a result of these complications the study was stopped in accordance with the local Ethics Research Committee guidelines.

CONCLUSION

A multimodal approach with translumbar lysis in combination with kinetic therapy followed by intrathecal nimodipine lavage proved to be effective against cerebral vasospasm and for clinical outcome. However, due to the observed complications with the occurrence of paraparesis in two patients of the study group the trial was stopped. Nevertheless, the promising preliminary results suggest a further development of the clinical protocol using a modified multimodal concept to prevent and treat cerebral vasospasm after severe SAH.

Exploring the impact of sexed semen on the structure of the dairy industry

Widespread commercial application of sexed semen is expected within the next decade because of continued improvements in fertility of sexed semen and sorting capacity. The objective of this study was to explore the potential impact of widespread application of sexed semen on the structure of the dairy industry in the United States. Historically, female offspring from all heifers and cows were needed to produce enough dairy replacement heifers to replace culled cows. The use of sexed semen allows for a decoupling of breeding decisions necessary to obtain an adequate supply of dairy replacement heifers from those needed to achieve pregnancies needed to start new lactations. Application of sexed semen allows dairy producers to select among their herds' potential dams and produce dairy replacement heifers from only the genetically superior animals. The rate of genetic progress is expected to increase, but not more than 15% of the rate of gain accomplished through sire selection achieved through conventional (nonsexed) artificial insemination breeding. The supply of dairy replacement heifers is expected to grow to meet and temporarily exceed current demand, resulting in reduced prices for dairy replacement heifers. Consequently, herd turnover rates are expected to increase slightly, and herd expansions may accelerate. The rate of consolidation of dairy farms is expected to increase. Widespread application of sexed semen may temporarily increase the supply of milk, which would result in lower milk prices. The cost of milk production will be reduced as well. Many breeding options exist for the genetically poorer cows in the herd. The optimal breeding mix depends on the value of the various kinds of calves that could be produced. More crossbred calves for beef production may be produced; however, a market for these crossbred calves is not well established. Increased specialization is expected with more dairy producers deciding not to raise their own heifers but to purchase replacements. Other dairy farms might specialize in producing genetically superior dairy replacement heifers for sale. Depending on the value of calves not raised for replacements, artificial insemination organizations might market beef conventional semen or beef male sexed semen to dairy farms. The use of sexed semen should lower the cost of progeny-testing programs and embryo transfer and enhance the value of genetic markers. Eventually, the economic benefits from the use of sexed semen will be passed on to consumers.

High efficiency transfection of glioma cell lines and primary cells for overexpression and RNAi experiments

In order to investigate the impact of signalling proteins on the phenotype and malignant behavior of glioblastoma cells, we optimized the transfection procedure of human glioblastoma cell lines U251, U373, GaMG and of primary cells obtained from a patient's tumor using nucleofection technology in conjunction with plasmid pmaxGFP. We describe the optimization procedure, show that a high percentage of the cells can be transfected and that nucleofection does not cause phenotypic alterations of the cells. Therefore, we conclude that nucleofection is a highly efficient tool to deliver plasmids for transient protein overexpression and siRNA for specific protein knock-down to different glioblastoma cell lines or primary cells.

Effects of automatic cluster remover settings on average milking duration, milk flow, and milk yield

A crossover study design was used in five commercial dairy herds to study the effect of altering the switch point settings for automatic cluster remover units on the average duration of unit attachment, milk flow, and milk yield. Automatic cluster remover switch point settings were alternated, for 1-wk periods, between 0.50 and 0.64 kg/min (1.1 and 1.4 lb/min) in one herd and between 0.73 and 0.82 kg/min (1.6 and 1.8 lb/min) in the four remaining herds. Parlor data were captured at 329 separate milking sessions (range 39 to 92 per herd), representing 239,393 individual cow milkings. While increasing the automatic cluster remover switch point setting was not associated with a change in average milking duration in one herd, it had the effect of significantly reducing the average milking duration by between 10.2 and 15.6 s per cow in the remaining four herds. Milk flow was significantly increased at higher switch point settings for all five herds. Higher automatic cluster remover switch point settings did not have a negative effect on milk yield in any of the herds studied and, in fact, were associated with increased milk yield in two of the five herds. Decreasing milking duration while either maintaining or increasing the volume of milk harvested should ultimately lead to improved milking efficiency and parlor performance. Modifying systems to increase automatic cluster remover switch point settings offers an important potential opportunity to increase parlor efficiency in commercial dairy herds.

Efficacy of digoxin for treatment of cats with dilated cardiomyopathy

The role of digoxin in treatment of cats with dilated cardiomyopathy and other forms of myocardial failure is unclear. We evaluated the chronotropic and inotropic effects of digoxin by comparing baseline, noninvasive indices of cardiac performance with those obtained after 9 +/- 1.3 (mean +/- SEM) days of digoxin treatment in 6 cats with heart failure attributable to dilated cardiomyopathy. Two-dimensionally directed, M-mode echocardiography and electrocardiography were used to determine left ventricular shortening fraction, preejection period (PEP), ejection time (LVET), PEP to LVET ratio, velocity of circumferential fiber shortening, electromechanical systole, heart rate, and PR interval. Treatment consisted of administration of furosemide (mean dosage, 2.4 mg/kg of body weight/day), digoxin in tablet form (approximately 0.01 mg/kg, q 48 h), aspirin (80 mg, q 48 h), and a commercial low-salt diet. In addition, 2 cats were administered short-term, low-dose fluids IV, and 2 were given taurine supplementation at rates of 500 and 1,000 mg/day. Other off-loading or inotropic agents were not administered. Therapeutic or toxic serum digoxin concentration was achieved in all cats. Significant (P less than 0.05) improvement was detected in mean values for shortening fraction, PEP, PEP to LVET ratio, and velocity of circumferential fiber shortening. Mean electromechanical systole and LVET did not change significantly. Improvement, as assessed by indices of cardiac function, was documented in 4 of the 6 cats treated with digoxin, including the 2 cats given taurine supplementation. In the cats given taurine, positive inotropic effect was observed prior to the time when taurine-induced improvement in ventricular function is detectable.(ABSTRACT TRUNCATED AT 250 WORDS)