Evoked potentials can predict future disability in people with clinically isolated syndrome.

BACKGROUND AND PURPOSE: The aim was to evaluate whether the addition of evoked potentials (EPs) which evaluate brainstem function to the EP score improves its ability to predict disease progression in people with clinically isolated syndrome (pwCIS). METHODS: For 94 pwCIS, data on disease activity and progression after 2.9 (1.4-4.1) years of follow-up were available. Baseline characteristics included magnetic resonance imaging (MRI) parameters, visual EPs, auditory EPs, somatosensory EPs of the median and tibial nerves, vestibular evoked myogenic potentials and tongue somatosensory EPs. RESULTS: A multivariable regression model including age, sex, total number of T2 lesions on baseline MRI and EP score >13 showed that the total number of T2 lesions on baseline MRI and EP score >13 increase the likelihood for sustained accumulation of disability (SAD). After controlling for age, sex and the total number of T2 lesions on baseline MRI, the hazard of SAD for participants with EP score >13 is 4.093 times that of participants with EP score ≤13. EP score >13 also increases the likelihood for progression measured with a composite measure of progression which uses the Expanded Disability Status Scale, the nine-hole peg test and the timed 25-ft walk (exp(B) = 5.577, 95% confidence interval 1.520-20.468, P = 0.01). CONCLUSION: The addition of EPs that evaluate brainstem function to the EP score enables prediction of the progression of disability in pwCIS.

Longitudinal assessment of autonomic nervous system in patients with first demyelinating event suggestive of multiple sclerosis.

BACKGROUND AND PURPOSE: As a high proportion of people with clinically isolated syndrome (pwCIS) exhibit sympathetic adrenergic and sudomotor dysfunction, the aim of this study was to investigate the evolution of autonomic nervous system (ANS) abnormalities in pwCIS over a 2-year follow-up. METHODS: This was a prospective cohort study in which 121 pwCIS were enrolled and followed for 2 years. After 2-year follow-up, data were available for 84 pwCIS. ANS symptoms were evaluated with the Composite Autonomic System Score-31 (COMPASS-31) and results of the ANS tests were expressed using the Composite Autonomic Scoring Scale (CASS) at baseline and visit at month 24. Symptomatic dysautonomia was defined if the patient had a COMPASS-31 value above the median of the whole cohort at baseline evaluation (COMPASS-31 > 6.79) and CASS score >0. RESULTS: Complete CASS data at baseline and month 24 were available for 62 patients; in 24 (38.7%) patients there was worsening, in 16 (25.8%) there was improvement and in 22 (35.5%) there was no change in CASS score. In 90% of pwCIS (72 of 80) there was no change in parasympathetic nervous system tests, whereas 47.3% (35 of 74) had either worsening or improvement in sympathetic adrenergic and 28.6% (20 of 70) had either worsening or improvement in sudomotor function. A multivariable regression model identified the total number of T2 lesions as an independent predictor for worsening of symptomatic dysautonomia. No predictors for worsening or improving of CASS score were identified. CONCLUSION: A substantial proportion of pwCIS experienced worsening of ANS abnormalities during the 2-year follow-up and magnetic resonance imaging parameters seemed to predict these abnormalities.

[Use of the Peptigel with Nanofibres in the Bone Defects Healing]. / Vyuzití peptigelu s nanovlákny k lécbe defektu kostní tkáne.

INTRODUCTION Traumatic bone injuries or pathological processes may sometimes result in very extensive bone defects. Currently, the standard procedure applied in clinical humane as well as veterinary medicine to fill a bone defect is the autogenous bone graft which, however, necessitates a more invasive procedure for the patient and in the cases of extensive defects it fails to provide adequate amount of graft. Synthetic bone replacements can be used with no further burden for the patient and can simultaneously be used as the carriers for bioactive molecules or therapeutic drugs. For clinical use, an easy and simple application is one of the requirements that have to be taken into consideration. These requirements are best satisfied by preparations in the form of gel, which may be injected into the defects of various shapes even through minimal surgical approach. MATERIAL AND METHODS Synthetic transparent PGD-AlphaProA hydro-peptide-gel was used as a basis to develop a composite hydrogel scaffold. This gel was enriched by cryogenically ground poly- -caprolactone nanofibers (PCL) in a ratio of 1 ml of gel to 16 µg of nanofibres. In experimental animals (laboratory rat Wistar, n=20), a single regular circular defect of 1.5 mm in diameter was drilled by a low speed drill machine across the whole width of distal femur diaphysis, identically in both the hind legs. In the right hindleg, this defect was filled by injection of 0.05 ml of the composite peptide gel with nanofibers (experimental defect). In the contralateral limb a similar defect was left untreated, without filling (control defect), for spontaneous healing. The group of experimental animals was subsequently divided into four sub-groups (A, B, C, D) for the purpose of further follow-up. One week after the surgical implantation, in the first group of experimental animals (Group A; n = 5) lege artis euthanasia was performed, a radiological examination of both the hind legs was carried out and a sample of the bone from both the control and experimental defect was collected for histologic examination. The other groups of experimental animals were evaluated similarly at 2, 4 and 6 weeks after the surgical procedure (Group B, C, D; n = 5). These groups of experimental animals were assessed using various histological techniques by two independent pathologists. RESULTS A difference between the control and the experimental bone defect was observed only at the healing stage at two weeks after the implantation, when a tendency for greater formation of new bone trabeculas was seen in the defect treated with the composite hydro-peptide-gel with PCL nanofibers. The results show a slightly higher angiogenesis and cellularity at the bone defect site with an increase of newly formed bone tissue and faster colonisation of lamellar bone structures by bone marrow cells at early stages of the healing process (1-2 weeks old defect). In the experimental and control groups, at the later stage of healing (4-6 weeks old defect), the process of healing and bone modelling at the defect site shows no detectable morphological differences. CONCLUSIONS The experimental use of hydro-peptide-gel with PCL nanofibers in vivo in laboratory rats shows very good applicability into the defect site and, compared to the untreated defect within two weeks after the implantation, accelerates the bone healing. This fact could be an advantage especially at the early stage of healing, and thus accelerate the healing of more extensive defects. Key words: peptide gel, polycaprolactone, PCL, replacement, bone, healing, scaffold, nanofibers, biomaterial.

The vestibular evoked myogenic potentials (VEMP) score: a promising tool for evaluation of brainstem involvement in multiple sclerosis.

BACKGROUND AND PURPOSE: Concerning the great importance of brainstem involvement in multiple sclerosis (MS), the aim of this study was to explore the role of the newly developed vestibular evoked myogenic potentials (VEMP) score as a possible marker of brainstem involvement in MS patients. PATIENTS AND METHODS: This was a prospective case-control study which included 100 MS patients divided into two groups (without and with clinical signs of brainstem involvement) and 50 healthy controls. Ocular VEMP (oVEMP) and cervical VEMP (cVEMP) measurements were performed in all participants and analyzed for latencies, conduction block and amplitude asymmetry ratio. Based on this the VEMP score was calculated and compared with Expanded Disability Status Scale (EDSS), disease duration and magnetic resonance imaging data. RESULTS: Multiple sclerosis patients with clinical signs of brainstem involvement (group 2) had a statistically significant higher percentage of VEMP conduction blocks compared with patients without clinical signs of brainstem involvement (group 1) and healthy controls (P = 0.027 and P < 0.0001, respectively). Similarly, the VEMP score was significantly higher in group 2 compared with group 1 (P = 0.018) and correlated with EDSS and disease duration (P = 0.011 and P = 0.032, respectively). Multivariate linear regression analysis showed that the VEMP score has a statistically significant influence on the EDSS score (P < 0.001, R(2) = 0.239). CONCLUSIONS: Interpretation of the oVEMP and cVEMP results in the form of the VEMP score enables better evaluation of brainstem involvement than either of these evoked potentials alone and correlates well with disability.

Effects of subchronic exposure to atrazine on zebrafish (Danio rerio).

The aim of this study was to investigate the effects of subchronic exposure to atrazine on fish growth and the development of histopathological changes in selected organs (gill, kidney, liver) in Danio rerio. Juvenile growth tests were performed on D. rerio according to OECD method No. 215. For 28 days, fish at an initial age of 30 days were exposed to the environmental atrazine concentration commonly detected in Czech rivers (0.3 microg/L) and a range of sublethal concentrations of atrazine (3.0, 30.0 and 90.0 microg/L). The results showed decreasing growth rates and morphological changes in the liver (dystrophic lesions of hepatocytes) at 90.0 microg/L of atrazine. The environmental concentration of atrazine in Czech rivers did not have any effect on fish growth and development of histopathological changes in D. rerio. The value of NOEC was 30.0 microg/L and the value of LOEC was 90.0 microg/L.

Efficacy and safety of Cerebrolysin after futile recanalisation therapy in patients with severe stroke.

INTRODUCTION: Golden standard of acute stroke treatment is recanalisation therapy. However, opening the occluded blood vessel sometimes does not show the expected clinical result or leads to haemorrhagic complications. As neuroinflammation and neurotoxicity play an important role in the pathophysiology of stroke, neuroprotective agents might preserve brain tissue after futile recanalisation. PATIENTS AND METHODS: After recanalisation therapy and not later than 24 h after symptoms onset, patients with initial NIHSS of ≥ 8 were assigned to the investigational and control group. The investigational group received intravenous Cerebrolysin as add-on therapy. The primary objective was to assess the clinical efficacy of Cerebrolysin. The secondary objective was to investigate its effect on haemorrhagic transition and to confirm its safety profile. RESULTS: Baseline characteristics of patients showed no significant differences between the two groups. No difference could be detected between the two groups in the mRS scale though the Cerebrolysin group showed descriptive superiority over the control group. We found a statistically significant difference considering haemorrhagic transition and mortality rate in favour of the Cerebrolysin group. DISCUSSION: The multimodal neurotrophic agent Cerebrolysin holds promise to impact on the late consequences of a reperfusion syndrome. Its influence on reducing neuroinflammation, promoting neuronal cell viability and neurogenesis as well as the stabilising effect on the blood-brain barrier suggests a protective effect on the neurovascular unit even when no recanalisation occurs. We confirmed the excellent safety profile of Cerebrolysin. CONCLUSION: Cerebrolysin as add-on therapy might be beneficial and safe for patients with acute stroke in terms of lowering risk for haemorrhagic complications after recanalisation therapy.

Experimental oral and ocular Encephalitozoon cuniculi infection in rabbits.

Encephalitozoon cuniculi is an obligate intracellular pathogen that has a wide host distribution, but primarily affects rabbits. The aim of this study was to characterize both the cell-mediated and the antibody response in rabbits after experimental infection using 2 different infection routes: oral and ocular. SPF rabbits were infected with low (10³ spores) and high (107 spores) infection doses. Monitored parameters included clinical signs, detection of spores in urine, antibody response detected with ELISA, and cell-mediated immunity detected by antigen-driven lymphocyte proliferation. At week 13 post-infection, half of the rabbits in each group were suppressed by intramuscular administration of dexamethasone. At week 18 post-infection, animals were euthanized. Clinical signs were mild with exacerbation after immunosuppression. Spores in urine and antigen-specific cell-mediated immunity were detected from weeks 5 and 4 post-infection, respectively. Specific IgM was detected 1 week after infection, and IgG antibodies followed 1 week later in rabbits infected with the high dose. Immunological responses were dose dependent. The authors can conclude that both oral and ocular experimental infection with E. cuniculi resulted in an immune response of the infected animals. Rabbits could be used as an experimental model for the study of ocular microsporidiosis.

Determinants of the prevalence of Heligmosomum costellatum (Heligmosomidae: Trichostrongyloidea) in a common vole population in southern Moravia, Czech Republic.

A study of nematode (Heligmosomum costellatum) prevalence in the common vole (Microtus arvalis) population was performed in 2002 and 2003 in an agricultural region of southern Moravia, Czech Republic. The influence of the trapping date, body weight, age, gender and reproduction of the common vole on the prevalence of the larvae of H. costellatum encapsulated in the stomach wall was examined. Of 503 common voles examined, 27.6% were H. costellatum positive. The prevalence of H. costellatum in the common vole population was influenced mainly by the weight, trapping date, year and reproductive state, as well as by the interactions between year and gender and between year and reproductive state. The influence of age was weak. The most infected common vole groups were the older, heavier and already reproducing females captured from April to August and all voles captured in 2002. In general, parasite prevalence seems to be dependent on the population parameters of the host species. However, the H. costellatum prevalence study in a single common vole population was not sufficient to fully describe and explain the nematode-host interactions.

Multimammate rat (Mastomys natalensis), Tristram's jird (Meriones tristrami) and Wagner's gerbil (Gerbillus dasyurus) as laboratory models of acute neosporosis.

To test the different sensitivity of rodents of the subfamily Murinae and Gerbillinae, Wagner's gerbils (Gerbillus dasyurus), Tristram's jirds (Meriones tristrami) and multimammate rats (Mastomys natalensis) were inoculated with Neospora caninum tachyzoites. Clinical signs of neosporosis appeared in all inoculated animals. Histopathological examination confirmed the presence of tachyzoites in brains, lungs, skeletal muscle, myocardium, liver, in serosa of stomach and intestines, and in vesicular accessory genital glands. An examination of brains by PCR revealed presence of N. caninum DNA in all experimentally N. caninum infected rodents. The susceptibility of Wagner's gerbils and Tristram's jirds further proved the high sensitivity of gerbiline rodents to the N. caninum infection. The finding of N. caninum tachyzoites in the vesicular accessory genital glands of the infected gerbils suggests the usefulness of the rodent model for demonstration of N. caninum in the male reproductive system. Moreover, the multimammate rat was a susceptible experimental host to be the first immunocompetent rodent of the subfamily Murinae.

Semi-spherical Radiofrequency Bipolar Device - A New Technique for Liver Resection: Experimental In Vivo Study on the Porcine Model.

The incidence of colorectal carcinoma is still growing in the Czech Republic and also all around the world. With success of oncological treatment is also growing a number of potential patients with liver metastases, who can profit from surgical therapy. The aim of this study was to confirm on porcine models that this method by using new surgical device is effective and safe for patients who have to undergo liver resection. The primary hypothesis of the study was to evaluate whether this new device is able to consistently produce homogeneous and predictable areas of coagulation necrosis without the Pringle maneuver of vascular inflow occlusion. The secondary hypothesis of the study was to compare the standard linear radiofrequency device and a new semi-spherical bipolar device for liver ablation and resection in a hepatic porcine model. Twelve pigs were randomly divided into two groups. Each pig underwent liver resection from both liver lobes in the marginal, thinner part of liver parenchyma. The pigs in first group were operated with standard using device and in the second group we used new developed semi-spherical device. We followed blood count in 0(th), 14(th) and 30(th) day from operation. 14(th) day from resection pigs underwent diagnostic laparoscopy to evaluate of their state, and 30(th) day after operation were all pigs euthanized and subjected to histopathological examination. Histopathological evaluation of thermal changes at the resection margin showed strong thermal alteration in both groups. Statistical analysis of collected dates did not prove any significant (p < 0.05) differences between standard using device and our new surgical tool. We proved safety of new designed semi-spherical surgical. This device can offer the possibility of shortening the ablation time and operating time, which is benefit for patients undergoing the liver resection.

Stimulated electron-acoustic-wave scattering in a laser plasma.

Intense laser-plasma interaction can be a source of various electronic instabilities. Recently, stimulated backscattering from a trapped electron-acoustic wave (SEAS) [Montgomery et al., Phys. Rev. Lett. 87, 155001 (2001)] was proposed to reinterpret spectra previously attributed to stimulated Raman scattering (SRS) from unrealistically low densities. By particle simulations in a uniform plasma layer, which is overdense for ordinary SRS, strong reflection by SEAS at the electron plasma frequency is found. Transient SEAS reflectivity pulsations are followed by strong relativistic heating of electrons. Physical conditions are explained by three-wave parametric coupling between laser light, standing backscattered wave and slow electron-acoustic wave. Regions in which SEAS reflection can dominate over SRS are singled out.

Impact of a high-phosphorus diet on the sonographic and CT appearance of kidneys in degus, and possible concurrence with dental problems.

The main aim of this study was to investigate the impact of pelleted diet of different mineral composition on the sonographic and CT appearance of kidneys in degus (Octodon degus). A total of 35 animals were randomly divided into five groups, fed diets containing different calcium and phosphorus contents (13.5 g/kg calcium and 6.3 g/kg phosphorus, or 9.1 g/kg calcium and 9.5 g/kg phosphorus) and given different amounts of exposure to UV light. Endoscopic examination of the oral cavity as well as renal ultrasonography and CT was performed four times at four-month intervals throughout the study. After 14 months of feeding an experimental diet, all degus were euthanased and subsequently all kidneys were collected for histopathological examination. Animals fed a diet with high dietary phosphate and improper calcium to phosphorus ratio showed severe nephrocalcinosis. Ultrasonographic and CT kidney abnormalities presented as hyperechogenicity and hyperdensity (interpreted as nephrocalcinosis), respectively. The most striking changes were seen at the corticomedullary zone. Ultrasonography and CT correlated in all cases with histopathological findings. Dental disease developed quickly in groups fed diets with an improper calcium and phosphorus content, with obvious apical and coronal elongation of all the teeth. A possible influence of UV light access could not be proved in this study.

Severe granulomatous lesions in several organs from Eustrongylides larvae in a free-ranging dice snake, Natrix tessellata.

During an extensive study regarding the epidemiology of larval Eustrongylides infestation in a free-ranging endangered population of dice snakes (Natrix tessellata) from Histria, Romania, an adult female was euthanized to evaluate pathologic changes. Parasites appeared as nodules at various locations: in subcutaneous connective tissues, on the serosae of the intestines and liver. Histologic sections revealed nematode larvae surrounded by a capsule, forming a parasitic granuloma with 3 layers: macrophage layer, lymphocyte layer, and fibrous capsule. Differences between newly formed and mature granulomas consisted mainly in the eosinophilic infiltration. Other types of parasitic granulomas of reptiles are discussed in comparison with our findings.

Self-organization in a dissipative three-wave interaction.

A nonlinear three-wave interaction in an open dissipative plasma model of a stimulated Raman backscattering is studied. An anomalous kinetic dissipation due to electron trapping and plasma wave breaking is accounted for in a hybrid kinetic-fluid scheme. We simulate a finite plasma with open boundaries and vary a transport parameter to examine a route to spatio-temporal complexity. An interplay between self-organization at micro (kinetic) and macro (fluid) scales is found through quasi-periodic and intermittent evolution of dynamical variables, dissipative structures and related entropy rates. A consistency with a general scenario of self-organization is claimed.