The Relevance of Reperfusion Stroke Therapy for miR-9-3p and miR-9-5p Expression in Acute Stroke-A Preliminary Study.

Reperfusion stroke therapy is a modern treatment that involves thrombolysis and the mechanical removal of thrombus from the extracranial and/or cerebral arteries, thereby increasing penumbra reperfusion. After reperfusion therapy, 46% of patients are able to live independently 3 months after stroke onset. MicroRNAs (miRNAs) are essential regulators in the development of cerebral ischemia/reperfusion injury and the efficacy of the applied treatment. The first aim of this study was to examine the change in serum miRNA levels via next-generation sequencing (NGS) 10 days after the onset of acute stroke and reperfusion treatment. Next, the predictive values of the bioinformatics analysis of miRNA gene targets for the assessment of brain ischemic response to reperfusion treatment were explored. Human serum samples were collected from patients on days 1 and 10 after stroke onset and reperfusion treatment. The samples were subjected to NGS and then validated using qRT-PCR. Differentially expressed miRNAs (DEmiRNAs) were used for enrichment analysis. Hsa-miR-9-3p and hsa-miR-9-5p expression were downregulated on day 10 compared to reperfusion treatment on day 1 after stroke. The functional analysis of miRNA target genes revealed a strong association between the identified miRNA and stroke-related biological processes related to neuroregeneration signaling pathways. Hsa-miR-9-3p and hsa-miR-9-5p are potential candidates for the further exploration of reperfusion treatment efficacy in stroke patients.

Analysis of Serum Markers of Perioperative Brain Injury and Inflammation Associated with Endovascular Treatment of Intracranial Aneurysms: A Preliminary Study.

Embolization is the preferred method for treating intracranial aneurysms due to its less invasive nature. However, recent findings suggest that even uncomplicated embolization may cause structural damage to the brain through ischemic or inflammatory mechanisms. This study aimed to find possible biomarkers of brain injury and inflammation in patients suffering from intracranial aneurysms who underwent endovascular treatment by measuring serological markers indicating brain damage. The study involved 26 patients who underwent uncomplicated intravascular stenting for unruptured intracranial aneurysms between January 2020 and December 2021. Blood samples were collected before the procedure, at 6-12 h, and at 24 h after the procedure. The following protein biomarkers levels were tested with ELISA: S100B, hNSE, TNF, hsCRP, FABP7, NFL, and GP39. Statistical analysis of the results revealed significant increases in serum levels for the four biomarkers: FABP7-before 0.25 (ng/mL) vs. 6-12 h 0.26 (p = 0.012) and vs. 24 h 0.27 (p < 0.001); GP39-before 0.03 (pg/mL) vs. 6-12 h 0.64 (p = 0.011) and vs. 24 h 0.57 (p = 0.001); hsCRP-before 1.65 (µg/mL) vs. 24 h 4.17 (p = 0.037); NFL-before 0.01 (pg/mL) vs. 6-12 h 3.99 (p = 0.004) and vs. 24 h 1.86 (p = 0.033). These biomarkers are recognized as potential indicators of neurovascular damage and should be monitored in clinical settings. Consequently, serum levels of NFL, GP39, hsCRP, and FABP7 measured before and 24 h after endovascular procedures can serve as important markers for assessing brain damage and indicate avenues for further research on biomarkers of neurovascular injury.

After Ischemic Stroke, Minocycline Promotes a Protective Response in Neurons via the RNA-Binding Protein HuR, with a Positive Impact on Motor Performance.

Ischemic stroke is the most common cause of adult disability and one of the leading causes of death worldwide, with a serious socio-economic impact. In the present work, we used a new thromboembolic model, recently developed in our lab, to induce focal cerebral ischemic (FCI) stroke in rats without reperfusion. We analyzed selected proteins implicated in the inflammatory response (such as the RNA-binding protein HuR, TNFα, and HSP70) via immunohistochemistry and western blotting techniques. The main goal of the study was to evaluate the beneficial effects of a single administration of minocycline at a low dose (1 mg/kg intravenously administered 10 min after FCI) on the neurons localized in the penumbra area after an ischemic stroke. Furthermore, given the importance of understanding the crosstalk between molecular parameters and motor functions following FCI, motor tests were also performed, such as the Horizontal Runway Elevated test, CatWalk™ XT, and Grip Strength test. Our results indicate that a single administration of a low dose of minocycline increased the viability of neurons and reduced the neurodegeneration caused by ischemia, resulting in a significant reduction in the infarct volume. At the molecular level, minocycline resulted in a reduction in TNFα content coupled with an increase in the levels of both HSP70 and HuR proteins in the penumbra area. Considering that both HSP70 and TNF-α transcripts are targeted by HuR, the obtained results suggest that, following FCI, this RNA-binding protein promotes a protective response by shifting its binding towards HSP70 instead of TNF-α. Most importantly, motor tests showed that reduced inflammation in the brain damaged area after minocycline treatment directly translated into a better motor performance, which is a fundamental outcome when searching for new therapeutic options for clinical practice.

The protective effect of low-dose minocycline on brain microvascular ultrastructure in a rodent model of subarachnoid hemorrhage.

The multifaceted nature of subarachnoid hemorrhage (SAH) pathogenesis is poorly understood. To date, no pharmacological agent has been found to be efficacious for the prevention of brain injury when used for acute SAH intervention. This study was undertaken to evaluate the beneficial effects of low-dose neuroprotective agent minocycline on brain microvascular ultrastructures that have not been studied in detail. We studied SAH brain injury using an in vivo prechiasmatic subarachnoid hemorrhage rodent model. We analyzed the qualitative and quantitative ultrastructural morphology of capillaries and surrounding neuropil in the rodent brains with SAH and/or minocycline administration. Here, we report that low-dose minocycline (1 mg/kg) displayed protective effects on capillaries and surrounding cells from significant SAH-induced changes. Ultrastructural morphology analysis revealed also that minocycline stopped endothelial cells from abnormal production of vacuoles and vesicles that compromise blood-brain barrier (BBB) transcellular transport. The reported ultrastructural abnormalities as well as neuroprotective effects of minocycline during SAH were not directly mediated by inhibition of MMP-2, MMP-9, or EMMPRIN. However, SAH brain tissue treated with minocycline was protected from development of other morphological features associated with oxidative stress and the presence of immune cells in the perivascular space. These data advance the knowledge on the effect of SAH on brain tissue ultrastructure in an SAH rodent model and the neuroprotective effect of minocycline when administered in low doses.

A Novel Improved Thromboembolism-Based Rat Stroke Model That Meets the Latest Standards in Preclinical Studies.

The animal thromboembolic model of ischemia perfectly mimics human ischemic stroke which remains the leading cause of disability and mortality in humans. The development of new treatment strategies was therefore imperative. The purpose of this study is to improve the thromboembolic stroke model in rats in order to design experiments that use motor tests, and are in accordance with the 3R principles to prevent complications and maintain the same size of the infarct repeatedly. Tail vein dye application, a protective skull mask and a stress minimization protocol were used as additional modifications to the animal stroke model. These modifications significantly minimized the pain and stress severity of the procedures in this model. In our experimental group of Long-Evans rats, a photo-induced stroke was caused by the application of a photosensitive dye (Rose Bengal) activated with white-light irradiation, thus eliminating the need to perform a craniotomy. The animals' neurological status was evaluated using a runway elevated test. Histological examination of the brain tissue was performed at 12, 24 and 48 h, and seven days post-stroke. Tissue examination revealed necrotic foci in the cortex and the subcortical regions of the ipsilateral hemisphere in all experimental groups. Changes in the area, width and depth of the necrotic focus were observed over time. All the experimental groups showed motor disturbances after stroke survival. In the proposed model, photochemically-induced stroke caused long-term motor deficits, showed high reproducibility and low mortality rates. Consequently, the animals could participate in motor tests which are particularly suitable for assessing the efficacy of neuro-regenerative therapies, while remaining in line with the latest trends in animal experimental design.

Effects of 17-ß-estradiol released from shape-memory terpolymer rods on sciatic nerve regeneration after injury and repair with chitosan nerve conduit in female rats.

The aim of this study was to assess 17-ß-estradiol (E2) influence on sciatic nerve regeneration after injury followed by a repair with chitosan conduit in ovariectomized female rats. The study was performed in 2 groups (n = 16) of rats: OVChit - after excision of a fragment of the sciatic nerve, a chitosan conduit was implanted; OVChitE10 group - additionally to chitosan conduit, shape-memory terpolymer rods based on poly(L-lactide-co-glycolide- co-trimethylene carbonate) releasing 17-ß-estradiol for 20 weeks were implanted. The mean number of regenerating axons and mean fiber area were significantly greater in 17-ß-estradiol-treated animals. In this group, the infiltrate of leukocytes was diminished. The presence of 17-ß-estradiol receptors alpha and beta in motoneurons in the spinal cord were discovered. This may indicate the location where 17-ß-estradiol affects the regeneration of the injured nerve. Estradiol released from the terpolymer rods for 20 weeks could enhance, to some extent, sciatic nerve regeneration after injury, and diminish the inflammatory reaction. In the future, 17-ß-estradiol entrapped in terpolymer rods could be used in the repair of injured peripheral nerves, but there is a need for further studies.

The influence of hypertension, diabetes, lipid disorders and the presence of the APOE4 allele on the cognitive functions of patients over 65 years of age.

Diabetes mellitus (DM) and hypertension (HA) are common diseases in the population of people over 65 years of age. Many studies show the impact of the long-lasting decompensation of these chronic diseases, often diagnosed in middle age, on the cognitive functioning of elderly patients. RESULTS: There is almost 30% prevalence of cognitive impairment among patients diagnosed with arterial hypertension. Possible explanation includes intensification of inflammatory processes in the central nervous system, influence on cerebral blood flow and acceleration of atherosclerosis. Another analyzed factor is the presence of diabetes. DM impacts the development of Alzheimer's disease. The inflammatory processes are intensified by advanced glycation products promoting atherosclerotic changes in blood vessels. In addition to that, the presence of hypoglycemic episodes significantly increases the risk of dementia. Moreover, approximately 78% of adult diabetic patients are also diagnosed with arterial hypertension, resulting in the coexistence of these CNS damaging mechanisms. The effect of elevated total cholesterol concentration on cognitive performance is still under debate and more research is needed. The role of the presence of ApoE4 in the development of cognitive dysfunctions, including Alzheimer's disease is emphasized. CONCLUSIONS: In daily medical practice, extraordinary attention should be paid to control of chronic diseases of the patient, especially in the middle age. It improves cognitive functioning, possibly extending the quality-adjusted life year expectancy.

Plasma Levels of Occludin and Claudin-5 in Acute Stroke Are Correlated with the Type and Location of Stroke but Not with the Neurological State of Patients-Preliminary Data.

The blood-brain barrier is the structure (BBB), which isolates the central nervous system from the external environmental. During a stroke, the BBB gets damaged, which is accompanied by changes in the concentrations and distributions of claudin-5, occludin, ZO-1, and other building blocks of the BBB. The aim of this study was to assess the concentrations of selected components of the BBB-occludin, claudin-5, and zonulin (ZO-1)-and to define a potential relationship between the concentrations of these three substances and the type of stroke, the location and extent of the infarct focus, the neurological/functional status in the acute phase of the disease, and the patient's clinical profile. METHODS: In this prospective study, we qualified patients with first-in-life stroke. All patients were analyzed according to: the presence of comorbidities, type of stroke (OCSP), treatment type in the first day of hospitalization, hemorrhagic transformation of infarct focus (ECASS), neurological status on the first day of stroke (NIHSS), functional status (mRS) on the ninth day of disease. In all patients, the plasma concentrations of claudin-5, occludin, and ZO-1 on the first day of stroke were examined and next, the mean concentrations were analyzed and compared between subgroups created on the basis of demographical and clinical features. RESULTS: The mean concentration of occludin was significantly higher in patients with partial anterior cerebral infarct (PACI) compared to patients with posterior cerebral infarct (POCI; 1.03 vs. 0.66 ng/mL; p = 0.009) and in patients with location of ischemic stroke in the carotid artery supply compared with in the vertebrobasilar supply (respectively: 1.036 vs. 0.660 ng/mL; p = 0.009). The mean concentration of claudin 5 was significantly higher in patients with PACI compared to patients with POCI (0.37 vs. 0.21 ng/mL; p = 0.011) and in patients with location of ischemic stroke in the carotid artery supply in comparison with vertebrobasilar supply (respectively: 0.373 vs. 0.249 ng/mL; p = 0.011). The differences in mean occludin and claudin 5 concentrations between female and male were statistically not significant, similarly between patients < 65 years and older. A significantly higher mean concentration of zonulin was observed in patients > 65 years of age compared to younger patients (0.59 vs. 0.48 ng/mL; p = 0.010) and in patients with arterial hypertension compared to patients without the disease (0.63 ng/mL vs. 0.26 ng/mL; p = 0.026). There were no statistically significant relationships between the concentration of occludin, claudin 5, and zonulin and the neurological status according to the NIHSS on the first day of stroke. CONCLUSIONS: The location of stroke in the anterior part of the brain's blood supply is associated with high blood levels of occludin and claudin 5 in the acute phase of stroke. The blood concentration of occludin is significantly lower in lacunar stroke comparing to this in non-lacunar stroke. Old age and arterial hypertension correlate positively with the concentration of zonulin 1 in acute stroke. There is no relationship between the blood levels of occludin, claudin 5, and zonulin 1 on the first day of stroke and the neurological and functional status in the acute phase of the disease.

Plasma Matrix Metalloproteinase-9 and Tissue Inhibitor of Matrix Metalloproteinase-1 as Prognostic Biomarkers in Critically Ill Patients.

Matrix metalloproteinase 9 (MMP-9) plays an important role in inflammatory and pathological processes by enabling the inflow of leukocytes to the site of infection or tissue damage. MMP-9 and tissue inhibitor of metalloproteinase 1 (TIMP-1) have been described as potential prognostic biomarkers in various clinical settings. The aim of the study was to evaluate the usefulness of plasma levels of MMP-9 and TIMP-1 as well as the MMP-9/ TIMP-1 ratio in predicting the outcome in patients admitted to the intensive care unit (ICU). The study included 56 critically ill patients with multiple organ failure. Plasma levels of MMP-9 and TIMP-1 were determined on hospitalization day 1, 2, 3 and 7. Nineteen (35.7%) patients died. The level of TIMP-1 was statistically significantly higher on day 1 and 7 of hospitalization in non-survivors, as compared to survivors (p=0.01). A statistically significant positive correlation was found between MMP-9 and TIMP-1. The MMP-9/TIMP-1 ratio was comparable in both groups during of observation (0.62 on day 1). The MMP-9/TIMP-1 ratio was positively correlated with the level of lactate and negatively correlated with platelet count. Likewise, TIMP-1 was positively correlated with the level of lactate. The level of MMP-9 was higher in the non-survivor group only on day 7 of observation. In conclusion, although TIMP-1 and MMP-9 concentrations were higher in non-survivors and the MMP-9/TIMP-1 ratio was related to some parameters of critical illness, further research is needed to verify whether they can serve as reliable biomarkers for early prognostication of ICU patients.

The modification of the ketogenic diet mitigates its stunting effects in rodents.

The high-fat and low-carbohydrate ketogenic diet (HFKD) is extensively studied within the fields of numerous diseases, including cancer and neurological disorders. Since most studies incorporate animal models, ensuring the quality of ketogenic rodent diets is important, both in the context of laboratory animal welfare as well as for the accuracy of the obtained results. In this study we implemented a modification to a commonly used ketogenic rodent chow by replacing non-resorbable cellulose with wheat bran. We assessed the effects of month-long treatment with either the unmodified or the modified HFKD on the growth and development of young male rats. Daily body weight, functional performance, and brain morphometric parameters were assessed to evaluate the influence of both applied diets on rodent development. Our results revealed that the unmodified ketogenic chow induced strong side effects that included weakness, emaciation, and brain undergrowth concomitant to growth inhibition. However, application of the ketogenic chow supplemented with wheat bran suppressed these adverse side effects, which was associated with the restoration of insulin-like growth factor 1 and a decrease in corticosterone levels. We have also shown that the advantageous results of the modified HFKD are not species- or sex-specific. Our data indicate that the proposed HFKD modification even allows for its application in young animals, without causing detrimental side effects.

Serum levels of the S100B protein and neuron-specific enolase are associated with mortality in critically ill patients.

INTRODUCTION: Evaluation of the prognostic potential of the S100B protein and neuron-specific enolase (NSE) as predictors of mortality in critically ill patients in intensive care units (ICU). MATERIALS AND METHODS: The study was conducted on 62 patients. Basic clinical variables and blood samples for S100B and NSE level testing were obtained during the first four days after admission. Mortality was described as the patient's death during hospitalization in the ICU. RESULTS: 35% of the patients had died. The level of S100B and NSE was significantly higher in non-survivors in comparison with survivors (p=0.007 and p=0.02, respectively). Mortality risk was significantly higher in patients with higher levels of biomarkers than the reference values for S100B (OR 9.00; 95% CI 2.38-33.99; p<0.001) as well as for NSE (OR 5.75; 95%CI 1.31-25.27; p=0.016). Receiver operating characteristic proved that S100B is a better mortality predictor than NSE (AUC 0.76 for S100B and 0.68 for NSE). From all the other variables, the Apache II score turned out to be the only significant predictor of mortality (AUC 0.88). CONCLUSION: There is a significant correlation between mortality in the ICU and increased serum concentration of S100B and NSE. This correlation is stronger for S100B. Testing for serum levels of S100B and NSE may be useful for prediction of treatment outcomes in the ICU patients.

Cognitive impairment and BDNF serum levels.

BACKGROUND/AIMS: To investigate the alterations of brain-derived neurotrophic factor (BNDF) serum levels in subjects with different intensity of cognitive impairment and different neurodegenerative processes. MATERIAL AND METHODS: Serum BDNF levels were analyzed by ELISA kit in 378 subjects: 134 Alzheimer's disease (AD) patients, 115 amnestic mild cognitive impairment (MCI) patients, and 129 controls divided into two groups: neurodegenerative control group (ND), consisting of 49 Parkinson's disease patients without any cognitive complaints, and cognitively normal control group (CN), consisting of 80 subjects without any neurological disorders. RESULTS: AD patients had significantly lower (p<0.001) BDNF serum levels compared to MCI, CN and ND controls. Age and education had significant influence on BDNF serum levels regardless the diagnosis or group assignment. We have found no influence of depression on BDNF serum levels either in our group as a whole, or in each group assessed separately. We found significant correlation between BDNF serum levels and cognitive impairments. After multiple comparisons between the groups, we found that, after adjustment for confounding factors (age, gender, education, depression, cognitive impairment), BDNF serum levels were the lowest in AD group (p=0.05). CONCLUSIONS: Advanced age and low educational level are associated with decreased BDNF serum levels. Decreased BDNF serum levels correspond to the severity of cognitive impairment. There is no correlation between BDNF serum levels and depressive symptoms.

Shape-Memory Terpolymer Rods with 17-ß-estradiol for the Treatment of Neurodegenerative Diseases: an In Vitro and In Vivo Study.

PURPOSE: Estradiol (E2)-loaded poly(L-lactide-co-glycolide-trimethylenecarbonate) (P(L-LA:GA:TMC)) rods with shape-memory were developed for the treatment of neurodegenerative diseases. Usefulness of the extrusion method in the obtaining process was also considered. The influence of structural and surface properties during hydrolytic degradation was developed. The possible therapeutic aspect of rods with E2 was determined. METHODS: The extruded rods were incubated in a PBS solution (pH 7.4, 37°C, 240 rpm). The amount of released E2 in vitro conditions was estimated by UV-VIS method. The following methods in the degradation of rods were applied: NMR, DSC, FTIR, GPC, SEM, and optical microscopy. Changes in water uptake and weight loss were also determined. In vivo study was performed on rats. Measurements of E2 level were performed before and after ovariectomy of rats using ELISA method. A sample of tissue adjacent to the site of the rod implantation was analysed under an optical microscope. RESULTS: A stable and steady degradation process ensured zero-order release of E2. The in vivo study indicated a significant increase in the E2 level in serum after ovariectomy. Moreover, structural and surface features indicated that the extrusion method was appropriate for obtaining E2-loaded rods. CONCLUSIONS: Shape-memory P(L-LA:GA:TMC) rods with E2 are an adequate proposal for further research in the field of neurological disorders.

Long-term High Fat Ketogenic Diet Promotes Renal Tumor Growth in a Rat Model of Tuberous Sclerosis.

Nutritional imbalance underlies many disease processes but can be very beneficial in certain cases; for instance, the antiepileptic action of a high fat and low carbohydrate ketogenic diet. Besides this therapeutic feature it is not clear how this abundant fat supply may affect homeostasis, leading to side effects. A ketogenic diet is used as anti-seizure therapy i.a. in tuberous sclerosis patients, but its impact on concomitant tumor growth is not known. To examine this we have evaluated the growth of renal lesions in Eker rats (Tsc2+/-) subjected to a ketogenic diet for 4, 6 and 8 months. In spite of existing opinions about the anticancer actions of a ketogenic diet, we have shown that this anti-seizure therapy, especially in its long term usage, leads to excessive tumor growth. Prolonged feeding of a ketogenic diet promotes the growth of renal tumors by recruiting ERK1/2 and mTOR which are associated with the accumulation of oleic acid and the overproduction of growth hormone. Simultaneously, we observed that Nrf2, p53 and 8-oxoguanine glycosylase α dependent antitumor mechanisms were launched by the ketogenic diet. However, the pro-cancerous mechanisms finally took the ascendency by boosting tumor growth.

Sciatic nerve regeneration in rats subjected to ketogenic diet.

OBJECTIVES: Ketogenic diet (KD) is a high-fat-content diet with insufficiency of carbohydrates that induces ketogenesis. Besides its anticonvulsant properties, many studies have shown its neuroprotective effect in central nervous system, but its influence on peripheral nervous system has not been studied yet. We examined the influence of KD on regeneration of peripheral nerves in adult rats. METHODS: Fifty one rats were divided into three experimental (n = 15) and one control (n = 6) groups. Right sciatic nerve was crushed and animals were kept on standard (ST group) or ketogenic diet, the latter was introduced 3 weeks before (KDB group) or on the day of surgery (KDA group). Functional (CatWalk) tests were performed once a week, and morphometric (fiber density, axon diameter, and myelin thickness) analysis of the nerves was made after 6 weeks. Body weight and blood ketone bodies level were estimated at the beginning and the end of experiment. RESULTS: Functional analysis showed no differences between groups. Morphometric evaluation showed most similarities to the healthy (uncrushed) nerves in KDB group. Nerves in ST group differed mostly from all other groups. Ketone bodies were elevated in both KD groups, while post-surgery animals' body weight was lower as compared to ST group. DISCUSSION: Regeneration of sciatic nerves was improved in KD - preconditioned rats. These results suggest a neuroprotective effect of KD on peripheral nerves.

Low Concentration of BDNF in the Acute Phase of Ischemic Stroke as a Factor in Poor Prognosis in Terms of Functional Status of Patients.

BACKGROUND According to recent studies, brain-derived neurotrophic factor (BDNF) probably plays a role in development of cerebral ischemia and can be significant for the prognosis of improved mobility after stroke. The aim of this prospective study was to evaluate the blood concentration of BDNF during the 1st day of first-ever ischemic stroke and find a potential association between BDNF concentration and the neurological status in the acute period, as well as between BDNF and the functional status in the sub-acute phase of stroke. MATERIAL AND METHODS The prospective study involved 87 patients aged 39-99 years (42 women, 45 men) with first-in-life complete ischemic stroke. All study subjects underwent analysis as follows: BDNF blood concentration and neurological status according to NIHSS on the 1st day of stroke, comorbidities, etiological type of ischemic stroke by ASCOD, and functional status on the 14th and 90th day after the onset according to mRankin scale. RESULTS Mean concentration of BDNF in the study group was 9.96 ng/mL±5.21, median 10.39 ng/mL. Patients aged ≤65 years (25 individuals) had a significantly higher mean concentration of BDNF (11.94 ng/mL±4.46; median 12.34 ng/mL) than the older subjects (62 individuals) with a mean concentration of 9.17 ng/mL±5.32 (median 8.66 ng/mL). The mean score by mRankin scale on the 90th day was significantly higher among patients with lower concentrations of BDNF on the 1st day of stroke, which reflects their poorer functional status. The functional status on the 90th day was significantly worse (3-6 points by Rankin scale) in patients who had BDNF below the mean value in the acute phase of stroke. The independent factors for poor functional status of patients on the 90th day after stroke were a score >4 points by NIHSS (RR 1.14; 95% CI: 1.00-1.31; p=0.027) and the concentration of BDNF below the mean value (assessed on the 1st day of stroke) (RR 14.49; CI 4.60-45.45; p=0.000). CONCLUSIONS The neurological status and concentration of BDNF on the 1st day of ischemic stroke are independent prognostic factors in medium-term observation. Reduction in the concentration of BDNF in the acute phase of stroke is a factor for poor prognosis in terms of the functional status of patients on the 90th day after onset.

Grafted Activated Schwann Cells Support Survival of Injured Rat Spinal Cord White Matter.

BACKGROUND AND OBJECTIVE: The influence of cultured Schwann cells on injured spinal cord in rats is examined. METHODS: Focal injury of spinal cord white matter at the T10 level was produced using our original non-laminectomy method with a high-pressure air stream. Schwann cells from 7-day predegenerated rat sciatic nerves were cultured, transducted with green fluorescent protein and injected into the cisterna magna (experimental group) 3 times: immediately after spinal cord injury and 3 and 7 days later. Neurons in the brainstem and motor cortex were labeled with FluoroGold (FG) delivered caudally from the injury site a week before the end of the experiment. The functional outcome and morphologic features of neuronal survival were analyzed during a 12-week follow-up. The lesions were visualized and analyzed using magnetic resonance imaging. The maximal distance of expansion of implanted cells in the spinal cord was measured and the number of FG-positive neurons in the brain was counted. RESULTS: Rats treated with Schwann cells presented significant improvement of locomotor performance and spinal cord morphology compared with the control group. The distance covered by Schwann cells was 7 mm from the epicenter of the injury. The number of brainstem and motor cortex FG-positive neurons in the experimental group was significantly higher than in the control group. CONCLUSIONS: The data show that activated Schwann cells are able to induce the repair of injured spinal cord white matter. The route of application of cells via the cisterna magna seemed to be useful for their delivery in spinal cord injury therapy.

[Schwann cells in therapy of spinal cord injuries]. / Komórki Schwanna w terapii uszkodzen rdzenia kregowego.

Schwann cells (SC) have a special activity in the repair processes after injury of the nervous system because of the capability of differentiation, migration, proliferation and myelinization of axons. They enhance production of numerous neurotrophic factors, thus creating a permissive environment for axonal regeneration. Experimental studies using SC in neuronal transplants showed that these cells with their basal membrane with adhesion molecules are attractive material for neural prostheses facilitating axon growth. Moreover, SC can produce stable myelin, restoring normal function of the neuron. Transplantations of SC in myelin injury have been used in animal models of multiple sclerosis, Parkinson's disease, and brain and spinal cord injuries. Because the transplanted SC have no ability to migrate within the normal nervous system, in many experiments SC derived from rat embryos were applied. Such cells migrated through normal nervous tissue and co-operated with host cells, their survival was longer, and myelin was not destroyed in multiple sclerosis. Also, fast recovery of motor activity in injured axons in rat spinal cord was observed, especially after transplantation of SC derived from skin progenitor cells or progenitor cells which have a phenotype characteristic for SC. Many authors have reported early apoptosis of transplanted SC, so a more complex repair strategy is needed that combines SC transplantation with other methods in order to achieve longer survival and optimal functional recovery following spinal cord injury.

The sitting position during neurosurgical procedures does not influence serum biomarkers of pulmonary parenchymal injury.

BACKGROUND: The sitting position during neurosurgical operations predisposes to air penetration through veins and the movement of the air through the pulmonary circulation. Contact of an air bubble with the endothelium can lead to acute lung injury. The presence of specific pulmonary proteins in the plasma such as surfactant protein D (SP-D) and Clara cell protein (CC16) is a biomarker of damaging processes at the air-blood barrier. The aim of our study was to examine the hypothesis that the level of investigated pulmonary biomarkers in plasma is higher in patients operated on in the sitting position. METHODS: The study included patients undergoing planned neurosurgical operations, who were divided into two groups: the sitting group (40 patients, operated on in the sitting position) and the supine group (24 patients, operated in the supine position). After the operation blood samples were drawn, centrifuged, frozen and stored until analyses were conducted. The determination of the SP-D and CC16 levels was performed using an ELISA test. Air embolism (VAE) was defined as a sudden drop in etCO2 of more than 2 mmHg and the presence of air bubbles in the aspirated blood from the central cannula. In all patients, the number of hospitalization days in the postoperative period was calculated. RESULTS: There were no differences in the average levels of SP-D between the groups (the mean in the sitting group was 95.56 ng/mL and the mean in the supine group was 101.21 ng/mL). The average levels of CC16 were similar in both groups as well (6.56 ng/mL in the sitting group and 6.79 ng/mL in the supine group). There was a statistically significant positive correlation between SP-D and CC16 values in both groups. VAE was diagnosed clinically in 12.5% of cases in the sitting group without a significant increase in SP-D and CC16 levels. On average, patients in both groups were discharged from the hospital within 9 days of surgery. CONCLUSION: The sitting position and intraoperative VAE during neurosurgical procedures do not affect the concentration of plasma biomarkers of pulmonary parenchymal injury such as SP-D and CC16.