Evaluation of CSF 8-iso-prostaglandin F2α and erythrocyte anisocytosis as prognostic biomarkers for delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

Delayed cerebral ischemia (DCI) is a serious, life-threatening, complication affecting patients who have survived the initial bleeding from a ruptured intracranial aneurysm. Due to the challenging diagnosis, potential DCI prognostic markers should be of value in clinical practice. According to recent reports isoprostanes and red blood cell distribution (RDW) showed to be promising in this respect. We conducted a prospective study of 27 aSAH patients and control group (n = 8). All patients from the study group were treated within the first day of the initial bleeding. We collected data regarding clinical status and results of biochemical, and radiological examinations. We measured cerebrospinal fluid (CSF) concentration of 8-iso-prostaglandin F2α (F2-IsoP) and RDW on days 1, 3, and 5. Both CSF F2-IsoP level and RDW-SD measured on day 1 were significant predictors of DCI. The receiver operating characteristics curve for DCI prediction based on the multivariate model yielded an area under the curve of 0.924 (95% CI 0.824-1.000, p < 0.001). In our study, the model based on the combination of RDW and the level of isoprostanes in CSF on the first day after the initial bleeding showed a prognostic value for DCI prediction. Further studies are required to validate this observation.

D-Loop Mutations as Prognostic Markers in Glioblastoma-A Pilot Study

Glioblastoma, a highly aggressive brain tumor, poses significant treatment challenges. A deeper investigation into its molecular complexity is essential for the identification of novel prognostic biomarkers and therapeutic strategies, potentially improving patient outcomes in terms of survival and quality of life. While nuclear DNA mutations have been extensively studied, the role of mitochondrial DNA (mtDNA) mutations, specifically in the D-loop region, remains poorly understood. This prospective case-control study aimed to assess the prognostic significance of the mtDNA D-loop m.16126T>C variant in glioblastoma patients. Immunohistochemistry and droplet digital PCR (ddPCR) were employed for mutation analysis, complemented by statistical analyses and a literature review. The study cohort comprised 22 glioblastoma patients (mean age 59.36 ± 14.17, 12 (54.55%) females), and 25 controls (59.48 ± 13.22, 12 (80%) females). The D-loop m.16126T>C variant was observed in four (18%) of the glioblastoma samples and was associated with shorter median survival (9.5 vs. 18 months; p = 0.016, log-rank test). This study underscores the importance of investigating mtDNA, especially D-loop variants, in glioblastoma, suggesting its potential as a prognostic biomarker and, therefore, its possible therapeutic targets, warranting further exploration.

Predictors of 30-day mortality for surgically treated patients with spontaneous supratentorial intracerebral haemorrhage and validation of the Surgical Swedish ICH Score: a retrospective single-centre analysis of 136 cases

We aimed to: identify independent risk factors of 30-day mortality in patients with surgically treated spontaneous supratentorial ICH, validate the SwICH Score within Polish Healthcare System, and compare the SwICH Score to the ICH Score. We carried out a single-centre retrospective analysis of the medical data juxtaposed with CT scans of 136 ICH patients treated surgically between 2008 and 2022. Statistical analysis was performed using the same characteristics as in the SwICH Score and the ICH Score. Backward stepwise logistic regression with both 5-fold cross-validation and 1000x bootstrap procedure was used to create new scoring system. Finally predictive potential of these scales were compared. The most important predictors of 30-days mortality were: ICH volume (p<0.01), GCS at admission (p<0.01), anticoagulant status (p=0.03), and age (p<0.01). The SwICH score appears to have a better predictive potential than the ICH score, although this did not reach statistical significance [AUC: 0.789 (95% CI: 0.715-0.863) vs. AUC: 0.757 (95% CI: 0.677-0.837)]. Moreover, based on the analysed characteristics, we developed our score (encompassing: age, ICH volume, anticoagulants status, GCS at admission), [AUC of 0.872 (95% CI: 0.815-0.929)]. This score was significantly better than previous ones. Differences in healthcare systems seem to affect the accuracy of prognostic scales for patients with ICH, including possible differences in indications for surgery and postoperative care. Thus, it is important to validate assessment tools before they can be applied in a new setting and develop population-specific scores. This may improve the effectiveness of risk stratification in patients with ICH.

Numerical flow experiment for assessing predictors for cerebrovascular accidents in patients with PHACES syndrome

There is an increased risk of cerebrovascular accidents (CVA) in individuals with PHACES, yet the precise causes are not well understood. In this analysis, we aimed to examine the role of arteriopathy in PHACES syndrome as a potential contributor to CVA. We analyzed clinical and radiological data from 282 patients with suspected PHACES syndrome. We analyzed clinical features, including the presence of infantile hemangioma and radiological features based on magnetic resonance angiography or computed tomography angiography, in individuals with PHACES syndrome according to the Garzon criteria. To analyze intravascular blood flow, we conducted a simulation based on the Fluid-Structure Interaction (FSI) method, utilizing radiological data. The collected data underwent statistical analysis. Twenty patients with PHACES syndrome were included. CVAs were noted in 6 cases. Hypoplasia (p = 0.03), severe tortuosity (p < 0.01), absence of at least one main cerebral artery (p < 0.01), and presence of persistent arteries (p = 0.01) were associated with CVAs, with severe tortuosity being the strongest predictor. The in-silico analysis showed that the combination of hypoplasia and severe tortuosity resulted in a strongly thrombogenic environment. Severe tortuosity, combined with hypoplasia, is sufficient to create a hemodynamic environment conducive to thrombus formation and should be considered high-risk for cerebrovascular accidents (CVAs) in PHACES patients.

Overlapping stimulation of subthalamic nucleus and dentato-rubro-thalamic tract in Parkinson's disease after deep brain stimulation

BACKGROUND

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) reduces tremor, rigidity, and akinesia. According to the literature, the dentato-rubro-thalamic tract (DRTt) is verified target for DBS in essential tremor; however, its role in the treatment of Parkinson's disease is only vaguely described. The aim of our study was to identify the relationship between symptom alleviation in PD patients and the distance of the DBS electrode electric field (EF) to the DRTt.

METHODS

A single-center retrospective analysis of patients (N = 30) with idiopathic Parkinson's disease (PD) who underwent DBS between November 2018 and January 2020 was performed. DRTt and STN were visualized using diffusion-weighted imaging (DWI) and tractography protocol of magnetic resonance (MR). The EF was calculated and compared with STN and course of DRTt. Evaluation of patients before and after surgery was performed with use of UPDRS-III scale. The association between distance from EF to DRTt and clinical outcomes was examined. To confirm the anatomical variation between DRTt and STN observed in tractography, white matter dissection was performed with the Klingler technique on ten human brains.

RESULTS

Patients with EF overlapping STN and DRTt benefited from significant motor symptoms improvement. Anatomical findings confirmed the presence of population differences in variability of the DRTt course and were consistent with the DRTt visualized by MR.

CONCLUSIONS

DRTt proximity to STN, the main target in PD DBS surgery, confirmed by DWI with tractography protocol of MR combined with proper predefined stimulation parameters may improve efficacy of DBS-STN.

Automated volumetric evaluation of intracranial compartments and cerebrospinal fluid distribution on emergency trauma head CT scans to quantify mass effect

Background

Intracranial space is divided into three compartments by the falx cerebri and tentorium cerebelli. We assessed whether cerebrospinal fluid (CSF) distribution evaluated by a specifically developed deep-learning neural network (DLNN) could assist in quantifying mass effect.

Methods

Head trauma CT scans from a high-volume emergency department between 2018 and 2020 were retrospectively analyzed. Manual segmentations of intracranial compartments and CSF served as the ground truth to develop a DLNN model to automate the segmentation process. Dice Similarity Coefficient (DSC) was used to evaluate the segmentation performance. Supratentorial CSF Ratio was calculated by dividing the volume of CSF on the side with reduced CSF reserve by the volume of CSF on the opposite side.

Results

Two hundred and seventy-four patients (mean age, 61 years ± 18.6) after traumatic brain injury (TBI) who had an emergency head CT scan were included. The average DSC for training and validation datasets were respectively: 0.782 and 0.765. Lower DSC were observed in the segmentation of CSF, respectively 0.589, 0.615, and 0.572 for the right supratentorial, left supratentorial, and infratentorial CSF regions in the training dataset, and slightly lower values in the validation dataset, respectively 0.567, 0.574, and 0.556. Twenty-two patients (8%) had midline shift exceeding 5 mm, and 24 (8.8%) presented with high/mixed density lesion exceeding >25 ml. Fifty-five patients (20.1%) exhibited mass effect requiring neurosurgical treatment. They had lower supratentorial CSF volume and lower Supratentorial CSF Ratio (both p < 0.001). A Supratentorial CSF Ratio below 60% had a sensitivity of 74.5% and specificity of 87.7% (AUC 0.88, 95%CI 0.82-0.94) in identifying patients that require neurosurgical treatment for mass effect. On the other hand, patients with CSF constituting 10-20% of the intracranial space, with 80-90% of CSF specifically in the supratentorial compartment, and whose Supratentorial CSF Ratio exceeded 80% had minimal risk.

Conclusion

CSF distribution may be presented as quantifiable ratios that help to predict surgery in patients after TBI. Automated segmentation of intracranial compartments using the DLNN model demonstrates a potential of artificial intelligence in quantifying mass effect. Further validation of the described method is necessary to confirm its efficacy in triaging patients and identifying those who require neurosurgical treatment.

The Anterior Inferior Cerebral Artery Variability in the Context of Neurovascular Compression Syndromes: A Narrative Review

The anterior inferior cerebellar artery (AICA) is situated within the posterior cranial fossa and typically arises from the basilar artery, usually at the pontomedullary junction. AICA is implicated in various clinical conditions, encompassing the development of aneurysms, thrombus formation, and the manifestation of lateral pontine syndrome. Furthermore, owing to its close proximity to cranial nerves within the middle cerebellopontine angle, AICA's pulsatile compression at the root entry/exit zone of cranial nerves may give rise to specific neurovascular compression syndromes (NVCs), including hemifacial spasm (HFS) and geniculate neuralgia concurrent with HFS. In this narrative review, we undertake an examination of the influence of anatomical variations in AICA on the occurrence of NVCs. Significant methodological disparities between cadaveric and radiological studies (CTA, MRA, and DSA) were found, particularly in diagnosing AICA's absence, which was more common in radiological studies (up to 36.1%) compared to cadaver studies (less than 5%). Other observed variations included atypical origins from the vertebral artery and basilar-vertebral junction, as well as the AICA-and-PICA common trunk. Single cases of arterial triplication or fenestration have also been documented. Specifically, in relation to HFS, AICA variants that compress the facial nerve at its root entry/exit zone include parabola-shaped loops, dominant segments proximal to the REZ, and anchor-shaped bifurcations impacting the nerve's cisternal portion.

Glucose-6-phosphate dehydrogenase and 8-iso-prostaglandin F2α as potential predictors of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Delayed cerebral ischemia (DCI) is a serious complication of aneurysmal subarachnoid hemorrhage (aSAH), which is responsible for significant death and disability. The dynamic balance between the production and elimination of reactive oxygen species (ROS) in patients with DCI is suspected be shifted to favor ROS formation. The authors assessed the relationship between F2-isoprostanes (F2-IsoPs), oxidative stress biomarkers, and glucose-6-phosphate dehydrogenase (G6PD), which are responsible for nicotinamide adenine dinucleotide phosphate (NADPH) production for glutathione system function, with post-aSAH DCI.

METHODS

The authors assessed 45 aSAH patients for F2-IsoP and G6PD concentration using commercial ELISA on days 2, 4, and 6 after aSAH. The authors examined the correlation between plasma F2-IsoP and G6PD concentrations and clinical factors with DCI occurrence and aSAH outcome.

RESULTS

Expectedly, the most important clinical predictors of DCI were Hunt and Hess grade and modified Fisher (mFisher) grade. Plasma F2-IsoP and G6PD concentrations were greater in aSAH patients than the control group (p < 0.01). F2-IsoP concentrations were greater and G6PD concentrations were lower in patients with DCI than those without (p < 0.01). Plasma F2-IsoP and G6PD concentrations on day 2 were correlated with DCI occurrence (p < 0.01). Plasma F2-IsoP concentrations on days 2 and 6 were correlated with outcome at 1 and 12 months (p < 0.01).

CONCLUSIONS

Decreased G6PD indirectly informs the reduced antioxidant response, especially for the glutathione system. G6PD concentration was lower in patients with DCI than those without, which may explain the increased F2-IsoP concentrations. mFisher grade, plasma F2-IsoP concentration, and G6PD concentration on day 2 after aSAH, in combination, may serve as predictors of DCI. Further research is necessary to investigate the therapeutic utility of F2-IsoPs and antioxidants in clinical practice.

Antiepileptic Properties of Scyllo-Inositol on Pentylenetetrazol-Induced Seizures

Epilepsy, with about 70 million affected people worldwide, is one of the biggest challenges of medicine today. It is estimated that about one-third of epileptic patients receive inadequate treatment. Inositols have proved effective in many disorders; hence, in the current study, we tested potential antiepileptic properties of scyllo-inositol (SCI)-one of the most common commercially available inositols-in zebrafish larvae with pentylenetetrazol-induced seizures. First, we studied the general effect of SCI on zebrafish motility, and then we tested SCI antiepileptic properties over short (1 h) and long (120 h) exposure protocols. Our results demonstrated that SCI alone does not reduce zebrafish motility regardless of the dose. We also observed that short-term exposure to SCI groups reduced PTZ-treated larva motility compared to controls (p < 0.05). In contrast, prolonged exposure did not produce similar results, likely due to the insufficient concentration of SCI given. Our results highlight the potential of SCI use in epilepsy treatment and warrant further clinical studies with inositols as potential seizure-reducing drugs.

Prognostic factors in diffuse leptomeningeal glioneuronal tumor (DLGNT): a systematic review

BACKGROUND

Diffuse leptomeningeal glioneuronal tumor (DLGNT) is a rare tumor, first described by the WHO Classification of Central Nervous System Tumors in 2016. The clinical course is variable. Most tumors have low-grade histological findings although some may have more aggressive features. The goal of this systematic review was to identify prognostic factors for poor overall survival (OS).

MATERIAL AND METHODS

We performed a systematic review using three databases (PubMed, Google Scholar, and Embase) and the following search terms: diffuse leptomeningeal glioneuronal tumor, DLGNT, DLMGNT. Statistical analysis was performed using Statistica 13.3.

RESULTS

We included 34 reports in our review comprising 63 patients, published from 2016 to 2022. The median OS was 19 months (range: 12-51 months). Using multivariable Cox survival analysis, we showed that Ki-67 ≥ 7%, age > 9 years, symptoms of elevated intracranial pressure (ICP) at admission, and the presence of contrast-enhancing intraparenchymal tumor are associated with poor OS. Receiver operating characteristic (ROC) analysis identified Ki-67 ≥ 7% as a significant predictor of poor OS.

CONCLUSIONS

Signs or symptoms of increased ICP with imaging findings of diffuse leptomeningeal enhancement should raise suspicion for DLGNT. In our systematic review, Ki-67 ≥ 7% was the most important prognostic factor for OS in DLGNT. The presence of intraparenchymal tumor with contrast enhancement was thought to represent disease progression and, together with patient age, was associated with poor OS.

Validation of the Elderly Traumatic Brain Injury Score: an observational case-control study

INTRODUCTION

Traumatic brain injury (TBI) poses a particular health risk for the elderly. The recently developed Elderly Traumatic Brain Injury Score (eTBI Score) combines the prognostic information of the risk factors characteristic of the geriatric population. We aimed to determine its validity and reliability on an independent sample.

METHODS

We present a retrospective analysis of 506 consecutive patients after TBI aged ≥65 years. The previously described nomogram and the eTBI Score were used. The primary outcome measure was mortality or vegetative state at 30 days after hospital admission.

RESULTS

Mortality or vegetative state rate was 21.3%. The nomogram and eTBI Score showed similar predictive performance with accuracy of 83.8% (95%CI 80.2%-87%) and 84.4% (95%CI 80.8%-87.6%), respectively. Based on the Youden index and C4.5 algorithm we divided patients according to the 3-tier pattern into low, high and medium risk groups. The outcome prediction in the first two groups was correct in 93.1% (survival in the low risk group) and 94.4% (mortality in the high risk group). Patients included in the medium risk group usually required surgical treatment (85.3%), and characterized for increased mortality or vegetative state (55%). Among patients with eTBI≥5 (n=221), there was no difference in outcome between those treated conservatively and surgically.

CONCLUSIONS

This is the first study confirming the validity of the eTBI Score and its close association with outcome of geriatric population after TBI. The novel 3-tier risk stratification scheme was applicable to both conservatively and surgically treated patients.

Plasma Amino Acids May Improve Prediction Accuracy of Cerebral Vasospasm after Aneurysmal Subarachnoid Haemorrhage

Aneurysmal subarachnoid haemorrhages (aSAH) account for 5% of strokes and continues to place a great burden on patients and their families. Cerebral vasospasm (CVS) is one of the main causes of death after aSAH, and is usually diagnosed between day 3 and 14 after bleeding. Its pathogenesis remains poorly understood. To verify whether plasma concentration of amino acids have prognostic value in predicting CVS, we analysed data from 35 patients after aSAH (median age 55 years, IQR 39-62; 20 females, 57.1%), and 37 healthy volunteers (median age 50 years, IQR 38-56; 19 females, 51.4%). Fasting peripheral blood samples were collected on postoperative day one and seven. High performance liquid chromatography-mass spectrometry (HPLC-MS) analysis was performed. The results showed that plasma from patients after aSAH featured a distinctive amino acids concentration which was presented in both principal component analysis and direct comparison. No significant differences were noted between postoperative day one and seven. A total of 18 patients from the study group (51.4%) developed CVS. Hydroxyproline (AUC = 0.7042, 95%CI 0.5259-0.8826, p = 0.0248) and phenylalanine (AUC = 0.6944, 95%CI 0.5119-0.877, p = 0.0368) presented significant CVS prediction potential. Combining the Hunt-Hess Scale and plasma levels of hydroxyproline and phenylalanine provided the model with the best predictive performance and the lowest leave-one-out cross-validation of performance error. Our results suggest that plasma amino acids may improve sensitivity and specificity of Hunt-Hess scale in predicting CVS.

Importance of substratum quality for potential competitive niche overlap between native and invasive unionid mussels in Europe

Infaunal freshwater mussels are highly threatened and declining worldwide. One of the potential threats to mussels consists of biological invasions. We intended to investigate the habitat overlap and behavioural differences between native (Unio pictorum, Unio tumidus, Anodonta anatina, Anodonta cygnea) and invasive (Asian Sinanodonta woodiana) unionid bivalves to determine potential sources of competition. Furthermore, we investigated differences between S. woodiana from the established population in artificially heated waters and from the recent population in a natural thermal regime. We used pairwise choice tests on mud, medium, coarse and very coarse sand, mixture of medium and coarse sand, fine, medium and coarse gravel, and observed mussel locomotion and burrowing in preferred and non-preferred substrata. All species generally preferred fine-grained materials. The widest preference range was exhibited by S. woodiana (both populations), whereas A. cygnea was the most selective. The preferences of the cold-water population of S. woodiana were shifted towards coarser materials compared to conspecifics from the heated waters, and highly overlapped with the preferences of the native species. Anodonta cygnea most often moved horizontally and spent the shortest time deeply burrowed. Both Unio species were deeply burrowed for the largest amount of time and the horizontal locomotion of U. tumidus was the lowest among the test species. Sinanodonta woodiana, especially from the heated water population, exhibited relatively weak locomotion (compared to A. cygnea) and burrowing (compared to Unio spp. and A. anatina). Deep burrowing was more common on fine-grained materials. Our results suggest that the native mussels can be threatened by S. woodiana due to their overlapping habitat preferences, potentially hindering habitat separation. However, mobile native mussels may be capable of migrating and avoiding competition. Accumulating knowledge of the biology and ecology of freshwater mussels could contribute to the creation and improvement of conservation plans to protect these threatened animals.

Study of the Potential Hepatoprotective Effect of Myo-Inositol and Its Influence on Zebrafish Development

Inositol is a natural substance found widely in plants. It is used in therapies for many medical cases. The aim of this study was to determine the toxicity of myo-inositol (MI) and to investigate its potential hepatoprotective character. In the first part of the study, zebrafish embryos were incubated with 5, 10, 20, 40, 60, 80, and 100 mg/mL MI. Endpoints such as survivability, hatching rate, malformation, and mobility were evaluated. Our results demonstrated that the high doses of MI lead to increased mortality and malformations and reduce the hatching rate in comparison to the control group. Moreover, low doses of this compound do not produce a negative effect on zebrafish and even have the ability to increase the hatching rate and mobility. In the second part of the study, the hepatoprotective effect of MI was tested. Zebrafish larvae from the line Tg (fabp10a:DsRed) were incubated for 24 h with 1% and 2% ethanol (EtOH), 5 mg/mL of MI with 1% EtOH, and 5 mg/mL of MI with 2% EtOH. No significant differences between the groups with EtOH and the group treated with EtOH with MI were observed. Our results suggest that MI has no positive benefits on hepatocytes of zebrafish larvae.

Risk Factors for Recanalization after Coil Embolization

The aim of our study was to identify risk factors for recanalization 6 months after coil embolization using clinical data followed by computational fluid dynamics (CFD) analysis. Methods: Firstly, clinical data of 184 patients treated with coil embolization were analyzed retrospectively. Secondly, aneurysm models for high/low recanalization risk were generated based on ROC curves and their cut-off points. Afterward, CFD was utilized to validate the results. Results: In multivariable analysis, aneurysm filling during the first embolization was an independent risk factor whilst packing density was a protective factor of recanalization after 6 months in patients with aSAH. For patients with unruptured aneurysms, packing density was found to be a protective factor whilst the aneurysm neck size was an independent risk factor. Complex flow pattern and multiple vortices were associated with aneurysm shape and were characteristic of the high recanalization risk group. Conclusions: Statistical analysis suggested that there are various factors influencing recanalization risk. Once certain values of morphometric parameters are exceeded, a complex flow with numerous vortices occurs. This phenomenon was revealed due to CFD investigations that validated our statistical research. Thus, the complex flow pattern itself can be treated as a relevant recanalization predictor.

Prophylactic use of dural tenting sutures in elective craniotomies in adults-is it necessary? A study protocol for a multicentre, investigator- and participant-blinded randomised, parallel-group, non-inferiority trial

Background

In the early days of neurosurgery, extradural haemorrhages (EDHs) contributed to a high mortality rate after craniotomies. Almost a century ago, Walter Dandy reported dural tenting sutures as an effective way to prevent postoperative EDH. Over time, his technique gained in popularity and significance to finally become a neurosurgical standard. Yet, several retrospective reports and one prospective report have questioned the ongoing need for dural tenting sutures. Dandy’s explanation that the haemostasis observed under hypotensive conditions is deceiving and eventually causes EDH may be obsolete. Today, proper intra- and postoperative care, including maintenance of normovolemia and normotension and the use of modern haemostatic agents, may be sufficient for effective haemostasis. Thus, there is a fundamental need to evaluate the necessity of dural tenting sutures in a solid, unbiased, evidence-based manner.

Methods

This study is designed as a randomised, multicentre, double-blinded, controlled interventional trial with 1:1 allocation. About one half of the participants will undergo craniotomy without dural tenting sutures and will be considered an intervention group. The other half will undergo craniotomy with these sutures. Both groups will be followed clinically and radiologically. The primary outcome is reoperation due to extradural haematoma. Secondary outcomes aim to evaluate the impact of dural tenting sutures on mortality, readmission risk, postoperative headaches, size of extradural collection, cerebrospinal fluid leak risk and the presence of any new neurological deficit. The study protocol follows the SPIRIT 2013 statement.

Discussion

It is possible that many neurosurgeons around the globe are tenting the dura in elective craniotomies which brings no benefit and only extends the operation. Unfortunately, there is not enough data to support or reject this technique in modern neurosurgery. This is the first study that may produce strong, evidence-based recommendations on using dural tenting sutures.

Trial registration, ethics and dissemination

The Bioethics Committee of the Medical University of Warsaw approved the study protocol (KB/106/2018). The trial is registered at http://www.clinicaltrials.gov (NCT03658941) on September 6, 2018. The findings of this trial will be submitted to a peer-reviewed neurosurgical journal. Abstracts will be submitted to relevant national and international conferences.

Trial status

Protocol version and date: version 1.5, 14.01.2020

First recruitment: September 7, 2018

Estimated recruitment completion: September 1, 2021

Porous Media Computational Fluid Dynamics and the Role of the First Coil in the Embolization of Ruptured Intracranial Aneurysms

Background: The objective of our project was to identify a late recanalization predictor in ruptured intracranial aneurysms treated with coil embolization. This goal was achieved by means of a statistical analysis followed by a computational fluid dynamics (CFD) with porous media modelling approach. Porous media CFD simulated the hemodynamics within the aneurysmal dome after coiling. Methods: Firstly, a retrospective single center analysis of 66 aneurysmal subarachnoid hemorrhage patients was conducted. The authors assessed morphometric parameters, packing density, first coil volume packing density (1st VPD) and recanalization rate on digital subtraction angiograms (DSA). The effectiveness of initial endovascular treatment was visually determined using the modified Raymond–Roy classification directly after the embolization and in a 6- and 12-month follow-up DSA. In the next step, a comparison between porous media CFD analyses and our statistical results was performed. A geometry used during numerical simulations based on a patient-specific anatomy, where the aneurysm dome was modelled as a separate, porous domain. To evaluate hemodynamic changes, CFD was utilized for a control case (without any porosity) and for a wide range of porosities that resembled 1–30% of VPD. Numerical analyses were performed in Ansys CFX solver. Results: A multivariate analysis showed that 1st VPD affected the late recanalization rate (p < 0.001). Its value was significantly greater in all patients without recanalization (p < 0.001). Receiver operating characteristic curves governed by the univariate analysis showed that the model for late recanalization prediction based on 1st VPD (AUC 0.94 (95%CI: 0.86–1.00) is the most important predictor of late recanalization (p < 0.001). A cut-off point of 10.56% (sensitivity—0.722; specificity—0.979) was confirmed as optimal in a computational fluid dynamics analysis. The CFD results indicate that pressure at the aneurysm wall and residual flow volume (blood volume with mean fluid velocity > 0.01 m/s) within the aneurysmal dome tended to asymptotically decrease when VPD exceeded 10%. Conclusions: High 1st VPD decreases the late recanalization rate in ruptured intracranial aneurysms treated with coil embolization (according to our statistical results > 10.56%). We present an easy intraoperatively calculable predictor which has the potential to be used in clinical practice as a tip to improve clinical outcomes.

Plasma amino acids indicate glioblastoma with ATRX loss

Glioblastoma (GB) is the most common primary brain tumour in adults. The lack of molecular biomarker, non-specific symptoms and fast growth rate often result in a significant delay in diagnosis. Despite multimodal treatment, the prognosis remains poor. Here, we verified the hypothesis that amino acids (AA) regulating the critical metabolic pathways necessary for maintenance, growth, reproduction, and immunity of an organism, may constitute a favourable target in GB biomarker research. We measured the plasma amino acids levels in 18 GB patients and 15 controls and performed the quantitative and qualitative metabolomic analysis of free AA applying high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). We present both the raw data and the results of our statistical analysis. The majority of AA were lowered in the study group in comparison to the control group. Five of these (arginine, glutamic acid, glutamine, glycine, and histidine) differed significantly (all p < 10^-5 and AUC > 0.9). Plasma levels of leucine and phenylalanine decreased in the case of GB with lost alpha-thalassemia/mental retardation X-linked (ATRX) expression on immunohistochemistry (p = 0.003 and 0.045, respectively). We demonstrated for the first time that certain plasma-free AA levels of GB patients were significantly different from those in healthy volunteers. Target profiling of plasma-free AA, identified utilizing LC-QTOF-MS, may present prognostic value by indicating GB patients with lost ATRX expression. The on-going quest for glioma biomarkers still aims to determine the detailed metabolic profile and evaluate its impact on therapy and prognosis.

Cancer Prevention by Natural Products Introduced into the Diet-Selected Cyclitols

Cancer is now the second leading cause of death worldwide. It is estimated that every year, approximately 9.6 million people die of oncologic diseases. The most common origins of malignancy are the lungs, breasts, and colorectum. Even though in recent years, many new drugs and therapeutic options have been introduced, there are still no safe, effective chemopreventive agents. Cyclitols seem poised to improve this situation. There is a body of evidence that suggests that their supplementation can decrease the incidence of colorectal cancer, lower the risk of metastasis occurrence, lower the proliferation index, induce apoptosis in malignant cells, enhance natural killer (NK) cell activity, protect cells from free radical damage, and induce positive molecular changes, as well as reduce the side effects of anticancer treatments such as chemotherapy or surgery. Cyclitol supplementation appears to be both safe and well-tolerated. This review focuses on presenting, in a comprehensive way, the currently available knowledge regarding the use of cyclitols in the treatment of different malignancies, particularly in lung, breast, colorectal, and prostate cancers.

Inflammatory Myofibroblastic Tumor of Spinal Canal: Brief Case Report

We describe a case of an intradural extramedullary inflammatory myofibroblastic tumor of the cervical spine. A 56-year-old woman presented with progressive neck pain, radiating to the right scapula, without any neurologic deficit. Magnetic resonance imaging showed an intradural extramedullary tumor with a dural tail sign, located at the C3-T1 segment with homogeneous contrast enhancement. The patient was operated on for a suspected meningioma. Pathologic examination showed fibrosis and inflammation with infiltration of B and T lymphocytes accompanied by plasmocytes, macrophages, and myofibroblast oocytes. We present the clinical course and review of the literature.

Predicting Outcome and Conservative Treatment Failure in Patients with Skull Fracture after Traumatic Brain Injury: A Retrospective Cohort Study

OBJECTIVE

 Traumatic brain injury (TBI) remains a major cause of morbidity and mortality worldwide. The prognostic value of skull fracture (SF) remains to be clearly defined. To evaluate the need for neurosurgical intervention and determine the risk factors of conservative treatment failure (CTF), we retrieved from the hospital database the records of patients with SF after TBI.

METHODS

 We analyzed 146 consecutive patients (mean age: 49.8 ± 17.5 years) treated at the department of neurosurgery in a 5-year period. Clinical data, radiologic reports, and laboratory results were evaluated retrospectively.

RESULTS

 A total of 63% of patients were treated conservatively, 21.9% were operated on immediately, and 15.1% experienced CTF. Overall, 73.3% had a favorable outcome; the mortality rate was 13%. Intracranial bleeding occurred in 96.6% of cases, basilar SF in 61%, and cerebrospinal fluid (CSF) leak in 2.8%. The independent risk factors for outcome were Glasgow Coma Scale (GCS) score, age, and platelet count (PCT). The independent risk factors for CTF were epidural hematoma, subdural hematoma, mass effect, edema, international normalized ratio, PCT, mean platelet volume, and CSF leakage. The consensus decision tree algorithm used at the accident and emergency department indicated patients with no need for neurosurgical intervention with an accuracy of 91.7%, sensitivity of 88.9%, and featured the importance of mass effect, GCS, and epidural hematoma.

CONCLUSIONS

 Tests included in the complete blood count appeared useful for predicting the course in patients with SF, although the most important factors were age and neurologic status, as well as radiologic findings. Our decision tree requires further validation before it can be used in everyday practice.

Mortality After Traumatic Brain Injury in Elderly Patients: A New Scoring System

BACKGROUND

Traumatic brain injury (TBI) remains a life-threatening condition characterized by growing incidence worldwide, particularly in the aging population, in which the primary goal of treatment appears to be avoidance of chronic institutionalization.

METHODS

To identify independent predictors of 30-day mortality or vegetative state in a geriatric population and calculate an intuitive scoring system, we screened 480 patients after TBI treated at a single department of neurosurgery over a 2-year period. We analyzed data of 214 consecutive patients aged ≥65 years, including demographics, medical history, cause and time of injury, neurologic state, radiologic reports, and laboratory results. A predictive model was developed using logistic regression modeling with a backward stepwise feature selection.

RESULTS

The median Glasgow Coma Scale (GCS) score on admission was 14 (interquartile range, 12-15), whereas the 30-day mortality or vegetative state rate amounted to 23.4%. Starting with 20 predefined features, the final prediction model highlighted the importance of GCS motor score (odds ratio [OR], 0.17; 95% confidence interval [CI], 0.09-0.32); presence of comorbid cardiac, pulmonary, or renal dysfunction or malignancy (OR, 2.86; 9 5% CI, 1.08-7.61); platelets ≤100 × 10⁹ cells/L (OR, 13.60; 95% CI, 3.33-55.49); and red blood cell distribution width coefficient of variation ≥14.5% (OR, 2.91; 95% CI, 1.09-7.78). The discovered coefficients were used for nomogram development. It was further simplified to facilitate clinical use. The proposed scoring system, Elderly Traumatic Brain Injury Score (eTBI Score), yielded similar performance metrics.

CONCLUSIONS

The eTBI Score is the first scoring system designed specifically for older adults. It could constitute a framework for clinical decision-making and serve as an outcome predictor. Its capability to stratify risk provides reliable criteria for assessing efficacy of TBI management.

Necessity of dural tenting sutures in modern neurosurgery: protocol for a systematic review

INTRODUCTION

The ongoing need for dural tenting sutures in a contemporary neurosurgical practice has been questioned in the literature for over two decades. In the past, these sutures were supposed to prevent blood collecting in the potential space between the skull and the dura by elevating the latter. Theoretically, with modern haemostasis and proper postoperative care, this technique should not be necessary and the surgery time can be shortened. Unfortunately, there is no evidence-based proof to either support or reject this hypothesis.

METHODS AND ANALYSIS

The systematic review will be performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement and The Cochrane Handbook for Systematic Reviews of Interventions. Eight electronic databases of peer-reviewed journals will be searched, as well as other sources. Eligible articles will be assessed against inclusion criteria. The intervention is not tenting the dura and this will be compared with the usual dural tenting sutures. Where possible, 'summary of findings' tables will be generated.

ETHICS AND DISSEMINATION

Ethical committee approval is not required for a systematic review protocol. Findings will be presented at international neurosurgical conferences and published in a peer-reviewed medical journal.

PROSPERO REGISTRATION NUMBER

CRD42018097089.

Diagnostic value of lateral ventricle ratio: a retrospective case-control study of 112 acute subdural hematomas after non-severe traumatic brain injury

PRIMARY OBJECTIVE

To evaluate correlation between the lateral ventricle ratio (LVR) and the risk of conservative treatment failure (CTF) among patients with acute subdural hematoma (ASDH) after non-severe traumatic brain injury (TBI), we retrieved from the hospital database and performed a retrospective analysis of 1339 cases with TBI treated during the 2008-2016 period.

METHODS AND PROCEDURES

112 patients with ASDH, GCS≥ 9 and initial conservative treatment were enrolled. They were divided according to the final treatment method applied (surgical or conservative). Clinical and radiological data was evaluated. We used ROC curve analysis and multivariate logistic regression model to identify risk factors of CTF.

MAIN OUTCOMES AND RESULTS

LVR higher than 1.48 calculated on admission CT scans was the strongest predictor of CTF, with sensitivity of 78.9% and specificity of 93.5% (AUC: 0.774-0.994). LVR, prolonged prothrombin time and coexisting traumatic subarachnoid hemorrhage were independent risk factors.

CONCLUSIONS

Despite limitations, study results support the view that patients after non-severe TBI with ASDH and with lateral ventricle asymmetry, defined as LVR> 1.48, require surgical treatment. LVR seems to be indirect, but still the closest method to quantify intracranial compliance. Thus, in the selected group of patients without clinical symptoms of critically diminished compensatory reserve, LVR could indicate those who need a surgical decompression.

Isoprostanes as potential cerebral vasospasm biomarkers

Despite enormous progress in medicine, symptomatic cerebral vasospasm (CVS), remains an unexplained clinical problem, which leaves both physicians and patients helpless and relying on chance, due to the lack of specific marker indicative of imminent danger as well as the lack of specific treatment. In our opinion CVS occurrence depends on dynamic disbalance between free radicals' formation (oxidative stress) and antioxidant activity. Isoprostanes are products of free-radical peroxidation of polyunsaturated fatty acids, and seem to mark a promising path for the research aiming to unravel its possible mechanism. Not only are they the biomarkers of oxidative stress in vivo and in vitro, but also have manifold biological effects (including vasoactive, inflammatory and mitogenic) via activation of the thromboxane A2 receptor (TBXA2R), both in physiological and pathophysiological processes. This review addresses the importance of isoprostanes in CVS in quest of appropriate biomarkers.

Recurrent Pineocytomalike Papillary Tumor of The Pineal Region: A Case Report and Literature Review

BACKGROUND

Papillary tumors of the pineal region (PTPRs) are malignant World Health Organization grade II/III tumors; however, they may perfectly mimic benign tumors (e.g., pineocytomas [World Health Organization grade I]).

CASE DESCRIPTION

We present a case of a 28-year-old man with a 35-mm tumor of the pineal region. Considering the typical radiological and pathologic presentation, the tumor was first diagnosed as pineocytoma. However, despite first total resection, the tumor recurred after 7 years. The recurrent neoplasm was composed mainly of papillary structures with low-grade atypical cells positive for CKAE1/AE3 and CK18. This categorization led to the final diagnosis of PTPR. The patient underwent adjuvant radiotherapy, which vastly improved his neurologic condition and resulted in significant tumor regression.

CONCLUSIONS

This case exemplifies that PTPRs can perfectly mimic pineocytomas and simple staining for cytokeratins may warrant correct diagnosis and better treatment.

[Characterization of chosen pro-angiogenic factors and anti-angiogenic therapies in ovarian cancer]

Ovarian cancer is a neoplasm characterized by notably malignancy. The poor results of treatment result not only from the lack of screening tests making diagnosis possible at an early stage, but also because of the insufficiently effective treatment methods. High hopes are placed in targeted therapies, using agents such as angiogenesis inhibitors, immune checkpoint inhibitors or anticancer vaccines. The aim of the work is to present the latest results of research on antiangiogenic drugs. Databases such as PubMed, Google Scholar and ClinicalTrials.gov were used. Antiangiogenic drugs are substances of various structure, the common feature of which is the influence on signaling pathways associated with such factors as VEGF, PDGF or Ang1 / 2. Bevacizumab is an antibody directed against VEGF-A. It is the first anti-angiogenic drug with proven efficacy, expressed in the extension of overall survival. This was demonstrated both in the group of patients with newly diagnosed advanced disease and in the situation of relapse. Other anti-angiogenic agents, such as trebananib, nintedanib or pazopanib, currently have not been proven to possess comparably high efficacy in the treatment of ovarian cancer. There are no known causes of disease progression despite maintenance therapy. The potential for combining bevacizumab with other targeted drugs such as PD-L1 inhibitors is currently being investigated.

[The coexistence of systemic lupus erythematosus and psoriasis - diagnostic and therapeutic problems]

The coexistence of systemic lupus erythematosus (SLE) and psoriasis is rarely observed in everyday clinical practice. Apart from providing a correct diagnosis, a major difficulty is to provide a proper treatment. In this case, for example, the use of systemic glucocorticosteroids may have a negative effect on the course of psoriasis, whereas phototherapy, which is widely practiced in psoriasis, may cause SLE exacerbation. The aim of the paper is to present the difficulty along the diagnostic process and in choosing the best type of treatment for patients with a coexistence of SLE and psoriasis and also a review of the subject-related literature.

Predictors of recanalization after endovascular treatment of posterior circulation aneurysms

INTRODUCTION

Posterior circulation aneurysms account for approximately 30% of all intracranial aneurysms, and their rupture often causes aneurysmal subarachnoid hemorrhage (aSAH). Because surgical treatment of posterior circulation aneurysms is difficult, endovascular treatment is commonly indicated. However, simple coil embolization is associated with a high rate of recanalization. Our goal was to investigate morphometric aneurysmal features assessed on pre-embolization computed tomography angiography (CTA) as predictors of recanalization in patients with posterior circulation aneurysms.

MATERIAL AND METHODS

We retrospectively analyzed data of 24 patients who underwent coil embolization due to rupture of saccular posterior circulation aneurysms. The morphometric features of aneurysms were measured based on pre-embolization 3D-CTA-aneurysm models, and aneurysmal size and volume were measured on digital subtraction angiography (DSA) images. The effectiveness of initial endovascular treatment was determined visually with the modified Raymond Roy classification directly after embolization and on follow-up DSAs. Recanalization was diagnosed when, compared to the primary embolization aneurysm appearance, compaction and filling of the aneurysm occurred. Statistical analysis was performed with Statistica 13.1 software.

RESULTS

Higher maximal aneurysm height perpendicular to the aneurysmal neck was associated with a greater aneurysm recanalization risk (12.12±5.13mm vs. 7.41±3.97mm, p=0.039), and this relationship remained significant after adjustment for patient's age, sex and aneurysm localization (OR=1.26, 95%CI: 1.01-1.60, p=0.047). Maximal aneurysm height perpendicular to the aneurysmal neck distinguished well between recanalized and non-recanalized aneurysms (AUC=0.755, 95%CI: 0.521- 0.989, p=0.033).

CONCLUSIONS

Predictors of aneurysm recanalization can help choose best endovascular treatment strategies, which could reduce complication rates.

Expression and variability of lipid metabolism genes in intracranial aneurysm

The objective of this study was to investigate the association between mRNA expression and single nucleotide polymorphisms (SNPs) of the ATP-binding cassette transporter (ABCA1) gene, apolipoprotein A1 (APOA1) gene, low-density lipoprotein (LDLR) gene and RNA gene located in the CDKN2B-CDKN2A cluster (CDKN2B-AS1) involved in lipid metabolism and the occurrence of intracranial aneurysm (IA). Fifty three IA patients, and 27 controls (IA-free) were enrolled in this study and were genotyped for seven single nucleotide polymorphisms. Increased expression of the LDLR gene in IA patients was observed. The A/G genotype and the A allele of the c. -113G>A polymorphism of the APOA1 gene were associated with increased occurrence of IA (ORs 12.36 and 14.14, respectively), while the G/G genotype and G allele showed the opposite tendency (ORs 0.06 and 0.07, respectively). We also detected that the A/A-G/A combined genotype of the c. -113G>A - APOA1 and g.46859A>G - LDLR SNPs was associated with a decreased occurrence of IA. Moreover, the A/G-G/G combined genotype of the c.656G>A - ABCA1 and c. -113G>A - APOA1 was associated with a decreased occurrence of IA. The results of our study suggest the association between expression and variability of lipid metabolism genes and occurrence of IA.

Temperature and pressure dependence of the luminescence of Eu(2+)-doped fluoride crystals Ba(x)Sr(1-x)F(2) (x = 0, 0.3, 0.5 and 1): experiment and model

This paper summarizes experimental evidence of anomalous luminescence in Eu(2+)-doped fluoride crystals Ba(x)Sr(1-x)F(2) (x = 0, 0.3, 0.5 and 1). Luminescence, luminescence excitation spectra and luminescence kinetics obtained at ambient and high hydrostatic pressure at various temperatures are discussed. Hydrostatic pressure was shown to cause a redshift of normal [Formula: see text] emission and anomalous luminescence. The experimental data shows the existence of temperature- and pressure-induced spectral transformations where the anomalous luminescence is replaced by normal emission of Eu(2+) centers. We present a model that predicts a strong electron-lattice coupling of the trapped excitons as well as the pressure effect of the spectral transformation from anomalous to normal emission.

Measurement of the in-medium K0 inclusive cross section in pi(-) -induced reactions at 1.15 GeV/c

The K0 meson production by pi(-) mesons of 1.15 GeV/c momentum on C, Al, Cu, Sn, and Pb nuclear targets was measured with the FOPI spectrometer at the Schwer-Ionen-Synchrotron accelerator of GSI. Inclusive production cross sections and the momentum distributions of K0 mesons are compared to scaled elementary production cross sections and to predictions of theoretical models describing the in-medium production of kaons. The data represent a new reference for those models, which are widely used for interpretation of the strangeness production in heavy-ion collisions. The presented results demonstrate the sensitivity of the kaon production to the reaction amplitudes inside nuclei and point to the existence of a repulsive KN potential of 20+/-5 MeV at normal nuclear matter density.

The influence of NMDA, a potent agonist of glutamate receptor, on behavioral activity of rats with experimental hyperammonemia evoked by liver failure

The study was designed to investigate the effects of NMDA receptor agonist on the behavioral activity in rats with experimental hyperammonemia. The experiments were performed on adult male Wistar rats. Experimental hyperammonemia was induced by intraperitoneal injections of tioacetamide (TAA, 200 mg/kg) for three consecutive days. Rats treated with saline (0.9%) served as control. Stimulation of the NMDA glutamatergic receptor was evoked by ip. injection of agonist N-methyl-D-aspartate acid (NMDA) in a dose of 30 mg/kg thirty minutes before experiments. Memory motivated affectively was evaluated in the passive avoidance responses. The speculative influence of the treatment on anxiety and motor activity was tested in elevated plus-maze and in open field respectively. To show change of NMDA receptor function after various doses of agonist, the seizures evoked by N-methyl-D-aspartate acid was carried out. This experiment showed that with rise of dose of NMDA time to appear of convulsions was contracted in rats with hyperammonemia as well as in control rats. Dose of NMDA caused convulsions was three times as less in rats with hyperammonemia than dose in control. Time of duration of convulsions was proportional to applied dose of NMDA and it lengthened with rise of agonist's dose in both groups of studied animals. Furthermore, we observed that NMDA increased motor activity of control rats in open field test, but not in rats with hyperammonemia (treated tioacetamide). Hyperammonemia did not have significant influence on motor activity and on a passive avoidance latency. The NMDA given in control and in hyperammonemia, increased acquisition, consolidation and recall of a passive avoidance responses. Moreover, NMDA had anxiogenic-like profile in elevated plus-maze. In rats with hyperammonemia NMDA had no influence on locomotor activity but it significantly increased memory in a passive avoidance responses. Furthermore, we observed that reactivity of NMDA glutamate receptor in rats with hyperammonemia was higher than in control rats.

2R,4R-APDC influence on hypoxia-induced impairment of learning and memory processes in passive avoidance test

We investigated the effects of 2R,4R-APDC, a selective group II metabotropic glutamate receptor (II mGluR) agonist, on certain behaviors in rats subjected and non-subjected to hypoxia. Short-term hypoxia was used as a model of experimentally induced amnesia. 2R,4R-APDC given intracerebroventricularly (icv) at doses of 1 mumol and 100 nmol decreased the number of crossings and rearings in the open field, impaired acquisition and consolidation but improved retrieval in the passive avoidance tests. It also shortened the time spent in open arms and prolonged the time spent in closed arms, reduced the number of open and closed arms entries in an elevated "plus" maze, which is a measure of anxiety. Four-minute hypoxia (2% O(2), 98% N(2)) retrieval of conditioned responses, and exhibited an anxiogenic effect in the elevated "plus" maze in rats, i.e. it reduced the time spent in open arms and the number of entries to closed and open arms. 2R,4R-APDC effect on locomotor and exploratory activity was not changed after hypoxia, i.e. we observed inhibition of motility. This agonist of II mGluRs used at both doses before hypoxia significantly improved acquisition and retrieval, and had dual effect on consolidation, viz. at a dose of 1 mumol, it impaired this process and at a dose of 100 nmol it improved it. In the elevated "plus" maze, rats pretreated with 2R,4R-APDC and then subjected to hypoxia shortened the time spent in open arms and prolonged the time spent in closed arms, reduced the time spent in open arms, i.e. the drug exhibited anxiogenic effect. We conclude, therefore, that 2R,4R-APDC itself impaired acquisition and consolidation, enhanced retrieval but in rats undergoing hypoxia, it improved acquisition, retrieval and when used at the dose of 100 nmol enhanced consolidation. 2R,4R-APDC had beneficial effect in hypoxia-induced memory impairment in passive avoidance test.

Nuclear stopping from 0.09A to 1.93A GeV and its correlation to flow

We present a complete systematics (excitation functions and system-size dependences) of global stopping and side flow for heavy ion reactions in the energy range between 0.09A and 1.93A GeV. For the heaviest system, Au+Au, we observe a plateau of maximal stopping extending from about 0.2A to 0.8A GeV with a fast drop on both sides. The degree of stopping, which is shown to remain significantly below the expectations of a full stopping scenario, is found to be highly correlated to the amount of side flow.

Azimuthal dependence of collective expansion for symmetric heavy-ion collisions

Detailed studies of the azimuthal dependence of the mean fragment and flow energies in the Au+Au and Xe+CsI systems are reported as a function of incident energy and centrality. Comparisons between data and model calculations show that the flow energy values along different azimuthal directions could be viewed as snapshots of the fireball expansion with different exposure times. For the same number of participating nucleons more transversally elongated participant shapes from the heavier system produce less collective transverse energy. Good agreement with Boltzmann-Uehling-Uhlenbeck calculations is obtained for a soft nuclear equation of state.

The role of ionotropic receptors of glutaminic acid in cardiovascular system. A. The influence of ionotropic receptor NMDA agonist - 1R,3R-ACPD and antagonist - DL-AP7 on the systemic pressure in rats

The aim of our study was to estimate the involvement of the peripheral N-methyl-D-aspartate receptors in regulation of cardiovascular function. For this purpose we examined the effects of intravenous injection of the agonists - NMDA (0.025; 0.05 and 1.0 mg/kg iv) and 1R-3R-ACPD (0.025; 0.05 and 1.0 mg/kg iv) - and antagonist of NMDA receptors DL-AP7 (0.02; 0.07 and 0.2 mg/kg iv). To determine if the effects of NMDA come from central or peripheral action we observed the effect during blockade of autonomic ganglion by using the nicotinic receptor antagonist - chlorisondamine (1.25 mg/kg iv). Administration of NMDA in three doses evoked slight hypotension after injection of the medium dose, 0.05 mg/kg. In the condition of pretreatment with 1.25 mg/kg chlorisondamine the hypotensive effect of NMDA was markedly reduced, what might suggest that NMDA-induced hypotension raised from the action within the brain. The competetive NMDA receptor antagonist DL-AP7 slightly increased the blood pressure. None of the injected drug had an influence on the heart rate in our in vivo study. It is concluded that the peripherally localized NMDA receptors may take a part in regulation of cardiovascular system, since their stimulation or blockade evoked the changes of systemic pressure.

6-Hydroxydopamine infusions into the structures of mesolimbic dopaminergic system alter the memory enhancing effect of CK-8US and caerulein in rats

The influence of bilateral destruction of dopaminergic endings in the anterior and in the posterior part of nucleus accumbens (NAS) and in the nucleus septi lateralis (NSL), by 6-hydroxydopamine (6-OHDA) infusions, on the facilitatory effect of cholecystokinin-unsulfated octapeptide (CCK-8US) and caerulein (CER) on memory motivated affectively was investigated in male Wistar rats. CCK-8US and CER were given s.c. at the doses of 10 microg/kg and 0.5 microg/kg respectively, immediately after a single learning trial in a passive avoidance situation, ten days after bilateral 6-OHDA lesions (desipramine pre-treatment; 25 mg/kg, i.p.) of these structures. Bilateral 6-OHDA lesions to the anterior and to the posterior part of NAS totally abolished and significantly attenuated, respective, the facilitatory effect of CCK-8US and CER on retention of a passive avoidance behaviour evaluated 24 h later, while bilateral lesions to NSL did not have any influence on it. Moreover, neither, destruction of dopaminergic endings in lesioned structures, nor application of CCK-8US and CER changed the spontaneous psychomotor activity of rats estimated in an "open field" test. These results may indicate that dopaminergic projection to the anterior part of NAS is mainly responsible for the facilitatory effect of CCK-8US and CER on memory motivated affectively.

Baclofen prevents hypoxia-induced consolidation impairment for passive avoidance in rats

We investigated the effects of baclofen, a selective GABA-B receptor agonist, on certain behaviours in rats after short-term hypoxia, as a model of experimentally induced amnesia. Baclofen given intraperitoneally (i.p.) in a dose of 0.25 mg kg(-1) increased the number of crossings and bar approaches in the open field, but was ineffective in the passive avoidance tests; it also shortened the time spent in open arms and reduced the number of open arms entries in an elevated 'plus' maze, being a measure of anxiety. Hypoxia (2% O2, 98% N2) within 4 min profoundly impaired locomotor activity, consolidation and retrieval of conditioned responses, and exhibited a proaxiogenic effect in the elevated 'plus' maze in rats--it reduced the time spent in open arms and the number of entries to closed and open arms. Baclofen's effect on locomotor and exploratory activity was substantially impaired after hypoxia, i.e. rats exhibited a significant reduction in those activities. This agonist of GABA-B receptor used before hypoxia significantly improved consolidation, but had no effect on retrieval. In the elevated 'plus' maze rats pre-treated with baclofen and then subjected to hypoxia prolonged the time spent in open arms, reduced the time spent in closed arms, and increased the number of entries to the arms, i.e. exhibited anxiolytic effect. We conclude, therefore, that baclofen improved consolidation of passive avoidance in rats undergoing hypoxia.

Genotype-dependent proteolytic response of spring wheat to water deficiency

Changes in proteolytic activities in response to water deficiency have been investigated in ten genotypes of spring wheat (Triticum aestivum L.) differing in response to water deficit stress and ability to acclimate. To determine subcellular localization and the type of proteases, mesophyll protoplasts isolated from wheat leaves were purified. Proteolytic activities were assayed using azocasein in the case of vacuolar proteinases at pH 5.0 and 125I-lysozyme in the case of extravacuolar ATP-dependent proteinases at pH 8.2. ATP-dependent proteolytic activity was found to be confined to the extravacuolar fraction while the azocaseinolytic activity to vacuoles. Dehydration increased vacuolar azocaseinolytic activity at both stages of plant development (shooting and heading), but the increase was significantly lower in more tolerant genotypes. The extravacuolar energy-dependent 125I-lysozyme degradation was low at the shooting stage but it was higher in the genotypes with a greater critical water saturation deficit. At the heading phase in the non-acclimated flag leaves ATP-dependent 125I-lysozyme degradation decreased in a genotype-dependent manner, but was enhanced upon acclimation to the same extent irrespective to the genotype ability to acquire dehydration tolerance during acclimation. The results presented indicate that both pathways of protein degradation are interlinked upon dehydration and are genotype dependent.

NMDA receptor antagonists change behavioral activity of rats treated with (S)-4CPG

The effect of (S)-4CPG [(S)-4-carboxyphenylglycine] (25, 50, 100 nmol icv) and the effect of AP-7 (5 nmol icv) or MK-801 (5 nmol icv) on the processes of acquisition, consolidation of conditioned reflexes and locomotor activity were tested in rats. Neither AP-7, MK-801 nor (S)-4CPG given alone changed locomotor activity. MK-801 significantly increased the effects of (S)-4CPG: on crossings at all applied doses, on rearings at 100 nmol, and on bar approaches at 50 nmol of (S)-4CPG. AP-7 enhanced the effects of 50 and 100 nmols of (S)-4CPG on crossings, 100 nmol of (S)-4CPG on rearings in the open field test. Neither AP-7, MK-801 nor (S)-4CPG at doses of 50 and 100 nmols influenced acquisition, but (S)-4CPG given alone at a dose of 25 nmol impaired acquisition. MK-801 impaired the action of 50 and 100 nmols of (S)-4CPG on acquisition. AP-7 only at a dose of 100 nmol inhibited (S)-4CPG-induced acquisition. Neither AP-7, MK-801 nor (S)-4CPG given alone changed consolidation in passive avoidance situation while co-administration of AP-7 and (S)-4CPG at the doses of 50 and 100 nmols, affected this process. The obtained results support our hypothesis concerning the co-operation between group I mGluRs and NMDA receptors in some behavioral tests and the modulating effect of group I mGluRs antagonist on central action of NMDA receptor antagonists.

Examination of the influence of 3,5-DHPG on behavioral activity of angiotensin II

The effects of the class I metabotropic glutamate receptor (mGluR) stimulation on the behavioral activity of angiotensin II (Ang II) was investigated in the present study. The experiments were performed on adult male Wistar rats. Stimulation of the group I of mGluR receptors was evoked by icv injection of (S)-3,5-dihydroxyphenylglycine (3,5-DHPG) at the dose of 0.01 and 1 nmol per rat. Fifteen minutes later, the animals were given icv solution containing 1 nmol of Ang II. Memory motivated affectively was evaluated in passive avoidance and active avoidance responses (CARs). Moreover, the speculative influence of the treatment on anxiety and motor activity was tested in elevated plus-maze and in open field, respectively. We observed that both compounds did not have statistically significant influence on motor activity of rats in open field test. However, 3,5-DHPG at the dose of 0.01 nmol given alone and combined with Ang II tended to increase locomotor activity. 3,5-DHPG, given alone, significantly facilitated consolidation process in a passive avoidance situation (only at the dose of 0.01 nmol) but had no influence on acquisition and recall of information. Examination of the influence of 3,5-DHPG on the acquisition and extinction of CAR proved that it did not alter acquisition and extinction of these responses. In the elevated plus-maze, 3,5-DHPG had anxiogenic-like profile. Ang II, as repeatedly shown before, greatly increased passive avoidance latency, rate of acquisition of CARs and decreased their extinction. On the other hand, Ang II induced anxiolytic-like effect in elevated plus-maze. The pre-treatment of rats with 3,5-DHPG tended to attenuate behavioral effects of the Ang II administration.

AIDA influences behavior in rats pretreated with baclofen

The influence of the blockade of group I metabotropic glutamate receptors (I mGluRs) by AIDA on some behavioral effects of rats pretreated with baclofen, an agonist of GABA-B receptor, was investigated using behavioral tests: the open field, the passive avoidance response and the elevated "plus" maze. Baclofen, applied intraperitoneally (ip) at a dose of 0.25 mg/kg, increased the number of crossed fields and bar approaches in rats in the open field test, and prolonged the time spent in the closed arms, shortened the time spent in the open arms and decreased the number of entries to the open arms in the elevated "plus" maze, but did not affect retrieval in the passive avoidance response. AIDA administered intracerebroventricularly (icv) alone at a dose of 100 nmol reduced crossings and rearings in the open field test, however, it had no effect on retrieval in the passive avoidance situation, nor did it show any influence in the elevated "plus" maze. AIDA given 15 min after baclofen significantly decreased mobility of rats (in the case of crossings to the level observed when AIDA was given alone), i.e. AIDA changed the effects of baclofen in the open field test. We also noted significant impairment of retrieval in rats pretreated with baclofen, which later received AIDA. AIDA significantly reduced the effect of baclofen on this memory process. In the elevated "plus" maze test, AIDA did not influence the behavior of rats pretreated with baclofen in comparison with the group treated with baclofen alone.

Synthesis of new chiral peptide nucleic acid (PNA) monomers

We have synthesised a series of new chiral type I peptide nucleic acid monomers in total yields of 36-53%, derived from Val, Ile, Ser(Bzl), Pro, and Trp, employing convenient procedure.

Influence of nitric oxide on the cardiovascular action of secretin in intact rats. Part A. Does nitric oxide influence the effect of secretin on arterial blood pressure?

The present study aimed to determine the influence of nitric oxide (NO) on the action of secretin in the cardiovascular system in intact rats. The studies involved the in vivo measurements of the systolic (SBP) and diastolic (DBP) blood pressure. The measurements were conducted when NO was absent, which was attained by the use of NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME), and when NO was in excess which was obtained by the administration of L-arginine (L-arg), the substrate for NO synthase or exogenous donor of NO, sodium nitroprusside (SNP). Secretin given at the following three doses: 0.75, 1.5 and 3.0 micromoles/kg iv increased SBP and DBP. L-NAME inhibited the slight hypertensive effect of secretin. L-arg abolished the hypertensive effect of the peptide given at the smallest dose, did not change the effect of secretin administered at the medium dose (which did not raise the pressure) and preserved the action of the highest secretin dose. SNP abolished the hypertensive effect of all doses of the peptide. In conclusion, the study has shown that both the lack and excess of NO change the in vivo effect of secretin in intact rats.