High CD142 Level Marks Tumor-Promoting Fibroblasts with Targeting Potential in Colorectal Cancer

Colorectal cancer (CRC) has a high incidence and is one of the leading causes of cancer-related death. The accumulation of cancer-associated fibroblasts (CAF) induces an aggressive, stem-like phenotype in tumor cells, and it indicates a poor prognosis. However, cellular heterogeneity among CAFs and the targeting of both stromal and CRC cells are not yet well resolved. Here, we identified CD142high fibroblasts with a higher stimulating effect on CRC cell proliferation via secreting more hepatocyte growth factor (HGF) compared to CD142low CAFs. We also found that combinations of inhibitors that had either a promising effect in other cancer types or are more active in CRC compared to normal colonic epithelium acted synergistically in CRC cells. Importantly, heat shock protein 90 (HSP90) inhibitor selected against CD142high fibroblasts, and both CRC cells and CAFs were sensitive to a BCL-xL inhibitor. However, targeting mitogen-activated protein kinase kinase (MEK) was ineffective in fibroblasts, and an epigenetic inhibitor selected for a tumor cell population with markers of aggressive behavior. Thus, we suggest BCL-xL and HSP90 inhibitors to eliminate cancer cells and decrease the tumor-promoting CD142high CAF population. This may be the basis of a strategy to target both CRC cells and stromal fibroblasts, resulting in the inhibition of tumor relapse.

Clinical parameters predict the effect of bilateral subthalamic stimulation on dynamic balance parameters during gait in Parkinson's disease

We investigated the effect of deep brain stimulation on dynamic balance during gait in Parkinson's disease with motion sensor measurements and predicted their values from disease-related factors. We recruited twenty patients with Parkinson's disease treated with bilateral subthalamic stimulation for at least 12 months and 24 healthy controls. Six monitors with three-dimensional gyroscopes and accelerometers were placed on the chest, the lumbar region, the two wrists, and the shins. Patients performed the instrumented Timed Up and Go test in stimulation OFF, stimulation ON, and right- and left-sided stimulation ON conditions. Gait parameters and dynamic balance parameters such as double support, peak turn velocity, and the trunk's range of motion and velocity in three dimensions were analyzed. Age, disease duration, the time elapsed after implantation, the Hoehn-Yahr stage before and after the operation, the levodopa, and stimulation responsiveness were reported. We individually calculated the distance values of stimulation locations from the subthalamic motor center in three dimensions. Sway values of static balance were collected. We compared the gait parameters in the OFF and stimulation ON states and controls. With cluster analysis and a machine-learning-based multiple regression method, we explored the predictive clinical factors for each dynamic balance parameter (with age as a confounder). The arm movements improved the most among gait parameters due to stimulation and the horizontal and sagittal trunk movements. Double support did not change after switching on the stimulation on the group level and did not differ from control values. Individual changes in double support and horizontal range of trunk motion due to stimulation could be predicted from the most disease-related factors and the severity of the disease; the latter also from the stimulation-related changes in the static balance parameters. Physiotherapy should focus on double support and horizontal trunk movements when treating patients with subthalamic deep brain stimulation.

Factors affecting postural instability after more than one-year bilateral subthalamic stimulation in Parkinson's disease: A cross-sectional study

Background

Balance impairment in Parkinson’s disease is multifactorial and its changes due to subthalamic stimulation vary in different studies.

Objective

We aimed to analyze the combination of predictive clinical factors of balance impairment in patients with Parkinson’s disease treated with bilateral subthalamic stimulation for at least one year.

Methods

We recruited 24 patients with Parkinson’s disease treated with bilateral subthalamic stimulation and 24 healthy controls. They wore an Opal monitor (APDM Inc.) consisting of three-dimensional gyroscopes and accelerometers in the lumbar region. We investigated four stimulation conditions (bilateral stimulation OFF, bilateral stimulation ON, and unilateral right- and left-sided stimulation ON) with four tests: stance on a plain ground with eyes open and closed, stance on a foam platform with eyes open and closed. Age, disease duration, the time elapsed after implantation, levodopa, and stimulation responsiveness were analyzed. The distance of stimulation location from the subthalamic motor center was calculated individually in each plane of the three dimensions. We analyzed the sway values in the four stimulation conditions in the patient group and compared them with the control values. We explored factor combinations (with age as confounder) in the patient group predictive for imbalance with cluster analysis and a machine‐learning‐based multiple regression method.

Results

Sway combined from the four tasks did not differ in the patients and controls on a group level. The combination of the disease duration, the preoperative levodopa responsiveness, and the stimulation responsiveness predicted individual stimulation-induced static imbalance. The more affected patients had more severe motor symptoms; primarily, the proprioceptive followed by visual sensory feedback loss provoked imbalance in them when switching on the stimulation.

Conclusions

The duration of the disease, the severity of motor symptoms, the levodopa responsiveness, and additional sensory deficits should be carefully considered during preoperative evaluation to predict subthalamic stimulation-induced imbalance in Parkinson’s disease.

Frequency-specific network activity predicts bradykinesia severity in Parkinson's disease

OBJECTIVE

Bradykinesia has been associated with beta and gamma band interactions in the basal ganglia-thalamo-cortical circuit in Parkinson's disease. In this present cross-sectional study, we aimed to search for neural networks with electroencephalography whose frequency-specific actions may predict bradykinesia.

METHODS

Twenty Parkinsonian patients treated with bilateral subthalamic stimulation were first prescreened while we selected four levels of contralateral stimulation (0: OFF, 1-3: decreasing symptoms to ON state) individually, based on kinematics. In the screening period, we performed 64-channel electroencephalography measurements simultaneously with electromyography and motion detection during a resting state, finger tapping, hand grasping tasks, and pronation-supination of the arm, with the four levels of contralateral stimulation. We analyzed spectral power at the low (13-20 Hz) and high (21-30 Hz) beta frequency bands and low (31-60 Hz) and high (61-100 Hz) gamma frequency bands using the dynamic imaging of coherent sources. Structural equation modelling estimated causal relationships between the slope of changes in network beta and gamma activities and the slope of changes in bradykinesia measures.

RESULTS

Activity in different subnetworks, including predominantly the primary motor and premotor cortex, the subthalamic nucleus predicted the slopes in amplitude and speed while switching between stimulation levels. These subnetwork dynamics on their preferred frequencies predicted distinct types and parameters of the movement only on the contralateral side.

DISCUSSION

Concurrent subnetworks affected in bradykinesia and their activity changes in the different frequency bands are specific to the type and parameters of the movement; and the primary motor and premotor cortex are common nodes.

IFITM1 expression determines extracellular vesicle uptake in colorectal cancer

The majority of colorectal cancer (CRC) patients carry mutations in the APC gene, which lead to the unregulated activation of the Wnt pathway. Extracellular vesicles (EV) are considered potential therapeutic tools. Although CRC is a genetically heterogeneous disease, the significance of the intra-tumor heterogeneity in EV uptake of CRC cells is not yet known. By using mouse and patient-derived organoids, the currently available best model of capturing cellular heterogeneity, we found that Apc mutation induced the expression of interferon-induced transmembrane protein 1 (Ifitm1), a membrane protein that plays a major role in cellular antiviral responses. Importantly, organoids derived from IFITM1^high CRC cells contained more proliferating cells and they had a markedly reduced uptake of fibroblast EVs as compared to IFITM1^low/- cells. In contrast, there was no difference in the intensity of EV release between CRC subpopulations with high and low IFITM1 levels. Importantly, the difference in cell proliferation between these two subpopulations disappeared in the presence of fibroblast-derived EVs, proving the functional relevance of the enhanced EV uptake by IFITM1^low CRC cells. Furthermore, inactivating IFITM1 resulted in an enhanced EV uptake, highlighting the importance of this molecule in establishing the cellular difference for EV effects. Collectively, we identified CRC cells with functional difference in their EV uptake ability that must be taken into consideration when using EVs as therapeutic tools for targeting cancer cells.

Fibroblast-Derived Extracellular Vesicles Induce Colorectal Cancer Progression by Transmitting Amphiregulin

Extracellular vesicles (EV), structures surrounded by a biological membrane, transport biologically active molecules, and represent a recently identified way of intercellular communication. Colorectal cancer (CRC), one of the most common cancer types in the Western countries, is composed of both tumor and stromal cells and the amount of stromal fibroblasts negatively correlates with patient survival. Here we show that normal colon fibroblasts (NCF) release EVs with a characteristic miRNA cargo profile when stimulated with TGFβ, one of the most important activating factors of fibroblasts, without a significant increase in the amount of secreted EVs. Importantly, fibroblast-derived EVs induce cell proliferation in epidermal growth factor (EGF)-dependent patient-derived organoids, one of the best current systems to model the intra-tumoral heterogeneity of human cancers. In contrast, fibroblast-derived EVs have no effect in 3D models where EGF is dispensible. This EV-induced cell proliferation did not depend on whether NCFs or cancer-associated fibroblasts were studied or on the pre-activation by TGFβ, suggesting that TGFβ-induced sorting of specific miRNAs into EVs does not play a major role in enhancing CRC proliferation. Mechanistically, we provide evidence that amphiregulin, transported by EVs, is a major factor in inducing CRC cell proliferation. We found that neutralization of EV-bound amphiregulin blocked the effects of the fibroblast-derived EVs. Collectively, our data suggest a novel mechanism for fibroblast-induced CRC cell proliferation, coupled to EV-associated amphiregulin.

Extracellular vesicles transmit epithelial growth factor activity in the intestinal stem cell niche

Extracellular vesicles (EV) are membrane-surrounded vesicles that represent a novel way of intercellular communication by carrying biologically important molecules in a concentrated and protected form. The intestinal epithelium is continuously renewed by a small proliferating intestinal stem cell (ISC) population, residing at the bottom of the intestinal crypts in a specific microenvironment, the stem cell niche. By using 3D mouse and human intestinal organoids, we show that intestinal fibroblast-derived EVs are involved in forming the ISC niche by transmitting Wnt and epidermal growth factor (EGF) activity. With a mouse model that expresses EGFP in the Lgr5+ ISCs, we prove that loss in ISC number in the absence of EGF is prevented by fibroblast-derived EVs. Furthermore, we demonstrate that intestinal fibroblast-derived EVs carry EGF family members, such as amphiregulin. Mechanistically, blocking EV-bound amphiregulin inhibited the EV-induced survival of organoids. In contrast, EVs have no role in transporting R-Spondin, a critical niche factor amplifying Wnt signaling. Collectively, we prove the important role of fibroblast-derived EVs as a novel transmission mechanism of factors in the normal ISC niche.

Extracellular vesicle release from intestinal organoids is modulated by Apc mutation and other colorectal cancer progression factors

Extracellular vesicles (EVs) are membrane-surrounded structures that transmit biologically important molecules from the releasing to target cells, thus providing a novel intercellular communication mechanism. Since EVs carry their cargo in a protected form and their secretion is generally increased in tumorigenesis, EVs hold a great potential for early cancer diagnosis. By 3D culturing, we provide evidence that colorectal cancer (CRC) patient-derived organoids, representing a state-of-the-art established and essential approach for studying human CRC, is a suitable model for EV analysis. When testing the effects of major factors promoting CRC progression on EV release in the organoid model, we observed that Apc mutation, leading to uncontrolled Wnt activation and thus to tumorigenesis in the vast majority in CRC patients, critically induces EV release by activating the Wnt pathway. Furthermore, the extracellular matrix component collagen, known to accumulate in tumorigenesis, enhances EV secretion as well. Importantly, we show that fibroblast-derived EVs induce colony formation of CRC organoid cells under hypoxia. In contrast, there was no major effect of tumor cell-derived EVs on the activation of fibroblasts. Collectively, our results with CRC and Apc-mutant adenoma organoids identify Apc mutation and collagen deposition as critical factors for increasing EV release from tumors. Furthermore, we provide evidence that stromal fibroblast-derived EVs contribute to tumorigenesis under unfavorable conditions in CRC.

Both trait-neutrality and filtering effects are validated by the vegetation patterns detected in the functional recovery of sand grasslands

Neutral theory of species assembly means that species assembly is governed by stochastic dispersal processes and fluctuations in established populations. An alternative theory suggests that assembly is strongly determined by functional trait filtering governed by abiotic and biotic filtering selecting species from the local species pool. To test these assumptions, in the current paper we analysed vegetation changes in the first 12 years of succession after heavy goose grazing on acidic sand. With trait-based analyses using permanent plots we addressed the following hypotheses: (i) High fluctuations in the trait values are typical in the first years; later a temporally divergent change in the trait patterns of sites with different vertical position became characteristic. (ii) In the functional diversity of regenerative and vegetative traits we expected different temporal patterns. We confirmed the first hypothesis, as in the first few years most traits displayed high fluctuations with no clear patterns. Our findings weakly supported the second hypothesis; while there were distinct patterns detected in the functional richness of traits, functional divergence and evenness displayed no clear distinctive patterns. We can conclude that both trait neutrality and filtering effects operate in the vegetation changes of the first period of secondary succession.

Possible roles of genetic variations in chemotherapy related cardiotoxicity in pediatric acute lymphoblastic leukemia and osteosarcoma

Background

The treatment of acute lymphoblastic leukemia (ALL) and osteosarcoma (OSC) is very effective: the vast majority of patients recover and survive for decades. However, they still need to face serious adverse effects of chemotherapy. One of these is cardiotoxicity which may lead to progressive heart failure in the long term. Cardiotoxicity is contributed mainly to the use of anthracyclines and might have genetic risk factors. Our goal was to test the association between left ventricular function and genetic variations of candidate genes.

Methods

Echocardiography data from medical records of 622 pediatric ALL and 39 OSC patients were collected from the period 1989–2015. Fractional shortening (FS) and ejection fraction (EF) were determined, 70 single nucleotide polymorphisms (SNPs) in 26 genes were genotyped. Multivariate logistic regression and multi-adjusted general linear model were performed to investigate the influence of genetic polymorphisms on the left ventricular parameters. Bayesian network based Bayesian multilevel analysis of relevance (BN-BMLA) method was applied to test for the potential interaction of the studied cofactors and SNPs.

Results

Our results indicate that variations in ABCC2, CYP3A5, NQO1, SLC22A6 and SLC28A3 genes might influence the left ventricular parameters. CYP3A5 rs4646450 TT was 17% among ALL cases with FS lower than 28, and 3% in ALL patients without pathological FS (p = 5.60E-03; OR = 6.94 (1.76–27.39)). SLC28A3 rs7853758 AA was 12% in ALL cases population, while only 1% among controls (p = 6.50E-03; OR = 11.56 (1.98–67.45)). Patients with ABCC2 rs3740066 GG genotype had lower FS during the acute phase of therapy and 5–10 years after treatment (p = 7.38E-03, p = 7.11E-04, respectively). NQO1 rs1043470 rare T allele was associated with lower left ventricular function in the acute phase and 5–10 years after the diagnosis (p = 4.28E-03 and 5.82E-03, respectively), and SLC22A6 gene rs6591722 AA genotype was associated with lower mean FS (p = 1.71E-03), 5–10 years after the diagnosis.

Conclusions

Genetic variants in transporters and metabolic enzymes might modulate the individual risk to cardiac toxicity after chemotherapy.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4629-6) contains supplementary material, which is available to authorized users.

Thermoluminescence characterization of Ag-doped Li2 B4 O7 single crystal materials

In this study, the thermoluminescence (TL) characteristics of Ag-doped and undoped lithium tetraborate (Li₂ B₄ O₇ , LTB) materials, grown using the Czochralski method, were reported. The TL properties of LTB:Ag, such as glow curve structure, dose response, fading and reproducibility, were investigated. The glow curve of the Li₂ B₄ O₇ :Ag single crystal consists of four peaks located at approximately 75, 130, 190 and 275°C; in undoped LTB, the single crystal shows a broad glow curve with peaks at 65, 90, 125, 160 and 190°C using a heating rate of 5°C/s in the 50-350°C temperature region. The high temperature peak of Ag-doped sample at 275°C has a nonlinear dose response within the range from 33 mGy to 9 Gy. There is a linear response in the range of 33-800 mGy; after which, a sublinear region appears up to 9 Gy for Ag-doped LTB single crystal. For undoped single crystal, the dose response is supralinear for low doses and linear for the region between 1 and 9 Gy. The thermal fading ratio of the undoped material is almost 60% for the high temperature peak after 7 days. Ag-doped LTB single crystal exhibits different behaviour over a period of 7 days.

[Extracellular vesicles and their role in hematological malignancies]

Extracellular vesicles are produced in all organisms. The most intensively investigated categories of extracellular vesicles include apoptotic bodies, microvesicles and exosomes. Among a very wide range of areas, their role has been confirmed in intercellular communication, immune response and angiogenesis (in both physiological and pathological conditions). Their alterations suggest the potential use of them as biomarkers. In this paper the authors give an insight into the research of extracellular vesicles in general, and then focus on published findings in hematological malignancies. Quantitative and qualitative changes of microvesicles and exosomes may have value in diagnostics, prognostics and minimal residual disease monitoring of hematological malignancies. The function of extracellular vesicles in downregulation of natural killer cells' activity has been demonstrated in acute myeloid leukemia. In chronic lymphocytic leukemia, microvesicles seem to play a role in drug resistance. Orv. Hetil., 2016, 157(35), 1379-1384.

Pharmacogenetics of anthracyclines

Anthracyclines constitute a fundamental part of the chemotherapy regimens utilized to treat a number of different malignancies both in pediatric and adult patients. These drugs are one of the most efficacious anticancer agents ever invented. On the other hand, anthracyclines are cardiotoxic. Childhood cancer survivors treated with anthracyclines often undergo cardiac complications which are influenced by genetic variations of the patients. The scientific literature comprises numerous investigations in the subject of the pharmacogenetics of anthracyclines. In this review, we provide a comprehensive overview of this research topic. Genetic variants are proposed targets in the personalized treatment in order to individualize dosing and therefore reduce side effects.

Long-term adjunctive lacosamide treatment in patients with partial-onset seizures

OBJECTIVE

To evaluate long-term (up to 5.5 years) safety, seizure reduction, and maintenance of efficacy of the antiepileptic drug (AED) lacosamide as adjunctive treatment in an open-label extension trial (SP774; ClinicalTrials.gov: NCT00515619).

METHODS

Three hundred and seventy-six adults with partial-onset seizures taking 1-3 AEDs enrolled following completion of a double-blind trial of adjunctive lacosamide. During open-label treatment, dosage of lacosamide (100-800 mg/day) and/or concomitant AEDs could be adjusted to optimize tolerability and seizure control.

RESULTS

Kaplan-Meier estimates of patient retention were 74.5% at 12 months, 52.9% at 36 months, and 40.6% at 60 months; median open-label treatment duration was 1183 days (~3.2 years). The most frequently reported treatment-emergent adverse events were dizziness (24.2%), headache (14.4%), diplopia (13.8%), and nasopharyngitis (13.8%); 9.0% of patients discontinued due to adverse events, most commonly dizziness (1.3%). Median percent reduction in 28-day seizure frequency from baseline of the double-blind trial was 49.9% overall, 55.4% for 1-year completers, and 62.3% for 3-year completers. Overall, 50.0% of patients were considered ≥50% responders (achieved ≥50% reduction in 28-day seizure frequency); 55.9% of 1-year completers and 63.0% of 3-year completers were ≥50% responders.

CONCLUSION

In eligible patients who entered the open-label extension trial, lacosamide was generally well tolerated. For most patients within each yearly completer cohort, seizure reduction was maintained over time.

LGI Proteins and Epilepsy in Human and Animals

Leucine‐rich glioma‐inactivated (LGI) protein was first thought to have a suppressor effect in the formation of some cancers. Developments in physiology and medicine made it possible to characterize the function of the LGI protein family and its crucial role in different conditions more precisely. These proteins play an important role in synaptic transmission, and dysfunction may cause hyperexcitability. Genetic mutation of LGI1was confirmed to be the cause of autosomal dominant lateral temporal lobe epilepsy in humans. The LGI2 mutation was identified in benign familial juvenile epilepsy in Lagotto Romagnolo (LR) dogs. Cats with familial spontaneous temporal lobe epilepsy have been reported, and the etiology might be associated with LGI protein family dysfunction. In addition, an autoimmune reaction against LGI1 was detected in humans and cats with limbic encephalitis. These advances prompted a review of LGI protein function and its role in different seizure disorders.

Origin and compensation of imaging artefacts in localization-based super-resolution microscopy

Interpretation of high resolution images provided by localization-based microscopy techniques is a challenge due to imaging artefacts that can be categorized by their origin. They can be introduced by the optical system, by the studied sample or by the applied algorithms. Some artefacts can be eliminated via precise calibration procedures, others can be reduced only below a certain value. Images studied both theoretically and experimentally are qualified either by pattern specific metrics or by a more general metric based on fluorescence correlation spectroscopy.

Clinical and genetic aspects of PCDH19-related epilepsy syndromes and the possible role of PCDH19 mutations in males with autism spectrum disorders

Epilepsy and mental retardation limited to females (EFMR), caused by PCDH19 mutations, has a variable clinical expression that needs further exploration. Onset of epilepsy may be provoked by fever and can resemble Dravet syndrome. Furthermore, transmitting males have no seizures, but are reported to have rigid personalities suggesting possible autism spectrum disorders (ASD). Therefore, this study aimed to determine the phenotypic spectrum associated with PCDH19 mutations in Dravet-like and EFMR female patients and in males with ASD. We screened 120 females suffering from Dravet-like epilepsy, 136 females with EFMR features and 20 males with ASD. Phenotypes and genotypes of the PCDH19 mutation carriers were compared with those of 125 females with EFMR reported in the literature. We report 15 additional patients with a PCDH19 mutation. Review of clinical data of all reported patients showed that the clinical picture of EFMR is heterogeneous, but epilepsy onset in infancy, fever sensitivity and occurrence of seizures in clusters are key features. Seizures remit in the majority of patients during teenage years. Intellectual disability and behavioural disturbances are common. Fifty percent of all mutations are missense mutations, located in the extracellular domains only. Truncating mutations have been identified in all protein domains. One ASD proband carried one missense mutation predicted to have a deleterious effect, suggesting that ASD in males can be associated with PCDH19 mutations.

Association between the Malnutrition-Inflammation Score and depressive symptoms in kidney transplanted patients

OBJECTIVE

Depressive symptoms and the Malnutrition-Inflammation Complex Syndrome (MICS) are prevalent in patients with chronic kidney disease. The complex relationship between MICS and depression has never been studied in kidney transplanted (Tx) patients. Here we evaluate the association between the Malnutrition-Inflammation Score (MIS) (Kalantar score) and depressive symptoms in Tx patients.

METHODS

Cross-sectional data of 973 prevalent Tx patients were analyzed. Sociodemographic and anthropometric characteristics and clinical and laboratory data were collected, and serum levels of inflammatory markers [C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α)] were measured. The Center for Epidemiologic Studies-Depression (CES-D) scale, the MIS and the Charlson Comorbidity Index (CCI) were computed. We used linear regression analysis to examine whether the relationship between MIS and CES-D score is independent from sociodemographic and laboratory parameters.

RESULTS

The CES-D score, corrected for age, gender and estimated glomerular filtration rate weakly but significantly correlated with serum IL-6 and the CCI (0.124 and 0.103, respectively; P<.05 for both) and marginally significantly with CRP (0.06; P=.06). We found a moderate correlation between CES-D score and MIS (0.262; P<.001). In a multivariable linear regression model, the MIS was independently associated with the CES-D score (B=0.110; P<.001).

CONCLUSIONS

The MIS was significantly associated with depressive symptoms after adjusting for important covariables in patients after renal transplantation.

Clinical, radiological and genetic aspects of leukodystrophies

The authors summarize the pathomechanism of the myelination process, the clinical, radiological and the genetical aspects of the leukodystrophies, as in 18q deletion syndrome, adrenoleukodysrtophy, metachromatic leukodystrophy, Pelizaeus-Merzbacher leukodystrophy, Alexander disease and olivo-ponto-cerebellar atrophy (OPCA).

Early vegetation development after grassland restoration by sowing low-diversity seed mixtures in former sunflower and cereal fields

We studied the early vegetation dynamics in former croplands (sunflower and cereal fields) sown with a low-diversity seed mixture (composed of 2 native grass species) in Egyek-Pusztakócs, Hortobágy National Park, East-Hungary. The percentage cover of vascular plants was recorded in 4 permanent plots per field on 7 restored fields between 2006 and 2009. Ten aboveground biomass samples per field were also collected in June in each year. We addressed two questions: (i) How do seed sowing and annual mowing affect the species richness, biomass and cover of weeds? (ii) How fast does the cover of sown grasses develop after seed sowing? Weedy species were characteristic in the first year after sowing. In the second and third year their cover and species richness decreased. From the second year onwards the cover of perennial grasses increased. Spontaneously immigrating species characteristic to the reference grasslands were also detected with low cover scores. Short-lived weeds were suppressed as their cover and biomass significantly decreased during the study. The amount of litter and sown grass biomass increased progressively. However, perennial weed cover, especially the cover of Cirsium arvense increased substantially. Our results suggest that grassland vegetation can be recovered by sowing low diversity mixtures followed up by yearly mowing. Suppression of perennial weed cover needs more frequent mowing (multiple times a year) or grazing.

Lateralizing value of postictal automatisms in temporal lobe epilepsy

PURPOSE

To describe clinical characteristics and lateralizing value of postictal automatisms in patients with temporal lobe epilepsy (TLE).

METHODS

One hundred and ninety-three videotaped seizures of 55 consecutive patients with refractory TLE and postoperatively seizure-free outcome were analyzed. Ictal as well as postictal (manual, oral and speech) automatisms were monitored.

RESULTS

Thirty-four (62%) of the 55 patients showed PA at least once during their seizures. Postictal automatism was observed in 70 (36%) attacks as manual (21%), oral (13%) or speech (9%) automatisms. Fifteen seizures contained a combination of two different postictal automatisms. The presence of postictal oral automatisms did not lateralize the seizure onset zone (p=0.834). Speech automatisms (repetitive verbal behavior) occurred more frequently after left-sided seizures (p=0.002). Postictal unilateral manual automatism showed no lateralizing value occurring by the ipsilateral hand in 10 and the contralateral upper limb in 6 seizures (p=0.454).

CONCLUSION

: Postictal automatism is a relatively frequent phenomenon in TLE. Postictal speech automatism lateralizes the seizure onset zone to the left hemisphere. Our observation can help the presurgical evaluation of TLE because verbal perseveration frequently occurs spontaneously, even in seizures without appropriate postictal language testing.

Electrode manipulation automatism during temporal lobe seizures

OBJECTIVE

To describe clinical characteristics and lateralizing value of peri-ictal electrode manipulation automatism (EMA) in patients with temporal lobe epilepsy (TLE) and compare our data with ictal manual automatisms described in the literature.

METHODS

Two-hundred and five videotaped seizures of 55 consecutive patients with refractory TLE and postoperatively seizure-free outcome were analyzed and EMA (tugging, scratching or adjusting the electrodes and cables) were monitored.

RESULTS

Twenty-eight (51%) patients showed EMA during 47 (23%) seizures. Ictal start was noted in 22 seizures and in 19/22 cases EMA finished before the end of seizure. Ictal EMAs were always associated with automotor seizure components. During 25 seizures, exclusively postictal EMAs were observed. Electrode manipulation was presented during 24/112 left-sided and 23/93 right-sided seizures (p = 0.742). Peri-ictal EMA was unilateral (completed by one hand) in 24/47 seizures (10 ictal, 14 postictal); it was done by the hand ipsilateral to the seizure onset zone in 17/24 and by contralateral hand in 7/24 cases (p = 0.064). We observed concomitant contralateral dystonic posturing during 3/10 seizures with unilateral ictal EMA. Unilateral hand automatism, temporally independent from the EMA appeared in 30 (64%) of the 47 seizures.

CONCLUSION

Peri-ictal EMA is a frequent phenomenon but shows no lateralizing value in TLE. The mechanism of EMA is in many ways dissimilar from that of earlier described manual automatisms.

Intentional seizure interruption may decrease the seizure frequency in drug-resistant temporal lobe epilepsy

We investigated the nature of preictal subjective phenomena and whether they had any effect on the seizure frequency in 95 adult patients with medial temporal lobe epilepsy. Seventy-three (77%) patients indicated that they experienced seizure-provoking factors. Ten patients (11%) had prodromas independent of auras, while auras occurred in 89%. Forty-four patients (46%) reported that that they had tried to stop their seizures in the presence of prodroma or aura and this action had resulted in success at least once. Twenty-one patients (22%) regularly tried to stop their seizures because this effort was often successful according to their interpretation. Patients who reported that they could frequently inhibit their seizures had 1.8 +/- 1.6 seizures/month, a significantly lower mean seizure frequency than those 74 patients who did not do it regularly (4.6 +/- 4.8 seizures/month, P<0.001). Patients who reported regular experience in inhibiting intentionally their seizures more often had affective (P=0.05) and vertiginous auras (P<0.01) as well as isolated auras (P<0.05). Patients who experienced provoking factors showed the same seizure frequency as those who did not. Our results suggest that intentional seizure inhibition had an impact on the severity of drug-resistant epilepsy.

Mosaic mutations of the LIS1 gene cause subcortical band heterotopia

BACKGROUND

Subcortical band heterotopia (SBH) is a neuronal migration disorder. DCX mutations are responsible for almost all familial cases, 80% of sporadic female cases, and 25% of sporadic male cases of SBH, and are associated with more severe gyral and migration abnormality over the anterior brain regions. Somatic mosaicism has previously been hypothesized in a patient with posteriorly predominant SBH and a mutation of the LIS1 gene, which is usually mutated in patients with severe lissencephaly. The authors identified mosaic mutations of LIS1 in two patients (Patients 1 and 2) with predominantly posterior SBH.

METHODS

After ruling out DCX mutations, the authors performed sequencing of the LIS1 gene in lymphocyte DNA. Because sequence peaks in both patients were suggestive of mosaic mutations, they followed up with denaturing high-pressure liquid chromatography analysis on blood and hair root DNA and compared the areas of heteroduplex and homoduplex peaks. A third patient showing the same mutation as Patient 2 but with no evidence of mosaicism was used for comparing the phenotype of mosaic vs full mutation.

RESULTS

The two patients with posterior SBH harbored a missense (Arg241Pro) and a nonsense (R8X) mosaic mutation of LIS1. The rate of mosaicism in Patient 1 was 18% in the blood and 21% in the hair roots, whereas in Patient 2 it was 24% and 31% in the same tissues. The patient with a full R8X mutation of LIS1 had severe lissencephaly.

CONCLUSIONS

Subcortical band heterotopia can occur with mosaic mutations of the LIS1 gene. Mutation analysis of LIS1, using highly sensitive techniques such as denaturing high-pressure liquid chromatography, should be considered for patients with posteriorly predominant subcortical band heterotopia and pachygyria.

Thermoluminescent and dosimetric properties of X ray phosphors

Rare earth doped oxide, phosphate, etc. are radioluminescent phosphors that have a broad application in X ray imaging, in luminescent screens, image transformers and in fluorescent lamp manufacturing. Some of them have interesting thermoluminescence features as well, which makes the phosphors applicable also in dosimetry. Two of these materials are Sr3(PO4)2 and BaFCl activated with europium. The general radioluminescence (RL) and thermoluminescence (TL) characteristics of these materials was investigated earlier and the preliminary results have already been published elsewhere. The aim of the present work is to investigate the interesting properties of these phosphors mainly from a dosimetric point of view (sensitivity, dose dependence, etc.).

Aicardi-Goutières syndrome displays genetic heterogeneity with one locus (AGS1) on chromosome 3p21

We have studied 23 children from 13 families with a clinical diagnosis of Aicardi-Goutières syndrome. Affected individuals had developed an early-onset progressive encephalopathy that was characterized by a normal head circumference at birth, basal ganglia calcification, negative viral studies, and abnormalities of cerebrospinal fluid comprising either raised white cell counts and/or raised levels of interferon-alpha. By means of genomewide linkage analysis, a maximum-heterogeneity LOD score of 5.28 was reached at marker D3S3563, with alpha=.48, where alpha is the proportion of families showing linkage. Our data suggest the existence of locus heterogeneity in Aicardi-Goutières syndrome and highlight potential difficulties in the differentiation of this condition from pseudo-TORCH (toxoplasmosis, rubella, cytomegalovirus, and herpes simplex virus types 1 and 2) syndrome.

Elastic model-based segmentation of 3-D neuroradiological data sets

This paper presents a new technique for the automatic model-based segmentation of three-dimensional (3-D) objects from volumetric image data. The development closely follows the seminal work of Taylor and Cootes on active shape models, but is based on a hierarchical parametric object description rather than a point distribution model. The segmentation system includes both the building of statistical models and the automatic segmentation of new image data sets via a restricted elastic deformation of shape models. Geometric models are derived from a sample set of image data which have been segmented by experts. The surfaces of these binary objects are converted into parametric surface representations, which are normalized to get an invariant object-centered coordinate system. Surface representations are expanded into series of spherical harmonics which provide parametric descriptions of object shapes. It is shown that invariant object surface parametrization provides a good approximation to automatically determine object homology in terms of sets of corresponding sets of surface points. Gray-level information near object boundaries is represented by 1-D intensity profiles normal to the surface. Considering automatic segmentation of brain structures as our driving application, our choice of coordinates for object alignment was the well-accepted stereotactic coordinate system. Major variation of object shapes around the mean shape, also referred to as shape eigenmodes, are calculated in shape parameter space rather than the feature space of point coordinates. Segmentation makes use of the object shape statistics by restricting possible elastic deformations into the range of the training shapes. The mean shapes are initialized in a new data set by specifying the landmarks of the stereotactic coordinate system. The model elastically deforms, driven by the displacement forces across the object's surface, which are generated by matching local intensity profiles. Elastic deformations are limited by setting bounds for the maximum variations in eigenmode space. The technique has been applied to automatically segment left and right hippocampus, thalamus, putamen, and globus pallidus from volumetric magnetic resonance scans taken from schizophrenia studies. The results have been validated by comparison of automatic segmentation with the results obtained by interactive expert segmentation.

[Specific antiepileptic therapy in childhood]

INTRODUCTION

This paper deals with basic rational antiepileptic therapeutic procedures in children with special consideration of numerous specificities which occur in childhood: difficulties in establishing correct syndrome diagnosis, predominantly after the first or first few seizures which makes it difficult to decide about appropriate syndrome-specific therapy in regard to efficacy, mechanism of action and range of antiepileptic action; difficulties in assessment of subjective factors (their adverse effects and recognition of seizures with subjective symptoms), children's vulnerability in regard to drug toxicity; age-specific pharmacokinetics of these drugs.

MATERIAL AND METHODS

The number of available antiepileptics today is great due to new drugs, but carbamazepine (CBZ) and valproate (VAL) are still basic antiepileptics, although carbamazepine's action is reduced to partial epilepsies. The paper describes range of action of available antiepileptics in regard to classification of epileptic seizures and most frequent epileptic syndromes.

DISCUSSION

Adverse effects of antiepileptic agents depend on the age, so examples of age-dependent adverse effects are given considering conventional and new antiepileptics. It is well known that optimal control of seizures depends not only on correct choice of drug, but also on appropriate dosage; it is necessary to be informed about age-dependent characteristics of clinical pharmacokinetics: resorption, metabolism, elimination and half-life of antiepileptics. Although 70-80% of children may be well treated with monotherapy, 15% of children require combination of 2 or more drugs causing drug interactions in resorption, distribution, metabolism and elimination. Examples of antiepileptic interactions as well as interactions of other drugs and antiepileptics are given. The paper also deals with special importance of the psychosocial aspects of epilepsy. These children are often unaccepted by others, mostly because others are afraid of their disease, which contributes to poor quality of life of these children. Development of intellectual, emotional functions, physical development and socialization, apart from affecting the choice of drug, make epilepsy treatment in children more complex, with special emphasis on mental-hygienic aspects of complete management of children.

CONCLUSION

Only a complex approach to child suffering from epilepsy may provide optimal development, quality of life improvement and complete social integration. Rational therapy of epilepsy in children requires good knowledge not only of age-specific syndromes, clinical pharmacology of anticonvulsants, their efficacy and range of action, but also specificity of their metabolism in children, profile of adverse effects as well as facing numerous nonmedical problems.

[Occurrence, causes and clinical characteristics of status epilepsy in adults]

INTRODUCTION

Status epilepticus, particularly grand mal, is one of the gravest and most dramatic conditions in neurology requiring immediate attention. Status epilepticus can occur in epileptic patients, often with higher mortality rates in symptomatic than idiopathic, but also as an initial symptom of a number of neurological and systemic diseases. No data are available on the exact incidence rates of status epilepticus. According to some assessments, 10% of patients have at least one status epilepticus in their lifetime (3,6). The prognosis mostly depends on the main cause, time in which seizures are stopped and age of patients. Latest data available in literature suggest the mortality rate of 2-8%.

MATERIALS AND METHODS

We analyzed frequency of hospital admissions, causes and clinical characteristics of status epilepticus in adults. The study was retrospective, based on case histories of epileptic patients from the Intensive Care Unit of the Neurology Clinic in Novi Sad in 1990, 1993 and 1995. Special emphasis was placed on differences in studied parameters between cases confirmed earlier and those with status epilepticus occurring as an initial symptom of some other illness or condition.

RESULTS

Number of hospital admissions rose slightly in the interval observed in comparison with total admissions (0.68% in 1990, 1.24% in 1993, and 1.73% in 1995) (Tabs 1 and 2). During 1993, status epilepticus was more frequent in cases confirmed earlier (69%) compared with the years 1990 (56%) and 1995 (43%) (Graf.1). Epileptic patients were younger on the average than nonepileptic ones (Tab. 3). Status epilepticus occurred more often in male patients (Tab. 4). Irregular treatment was the prevailing cause in epileptic patients (Tab 5). Symptomatic status epilepticus was reported higher in 1990 and 1995, and stroke was definitely the predominant cause (Tab 6). Convulsive grand mal status prevailed in all patients (Graf 2). Focal status was a more frequent finding in nonepileptic patients (Graf 3). Every third in 16 patients died in 1993 and every fifth in 23 in 1995 probably due to the acute destructive brain damage rather than the status itself. No deaths occurred in 1990.

DISCUSSION

According to research carried out by other authors, half of grand mal status cases occurred in confirmed epileptics (4). In our study the grand mal status was reported in 70.4% cases of epilepsy. Primary cause was abrupt withdrawal of antiepileptic treatment, infections, alcohol abuse and use of convulsive drugs. This is compatible with our results which confirm that grand mal status either primary or with secondary generalization prevail in both groups of patients (7,8,9). In terms of causes of status epilepticus in nonepileptic patients, literature data mainly suggest cerebral trauma, frontal brain tumors, cerebral arteriosclerosis or other vascular disorders and anaphylaxis (4). Our results point to stroke as the major cause of status epilepticus in nonepileptic patients, similar with data presented by Towne (10). There is no data in literature concerning the relation between sex of patients and occurrence of status. In our study status epilepticus occurred more frequently in male patients.

CONCLUSION

The grand mal status was the major clinical type of status in all patients and was primarily caused by discontinued or irregular antiepileptic treatment in patients with confirmed epilepsy, and by stroke in nonepileptic patients.

[Mechanisms of epileptogenesis and antiepileptic drugs]

Contemporary data about the mechanisms of epileptogenesis are reviewed. The role of the neuronal membrane and synapsis in the neurons changed by epilepsy is particularly pointed out. The concept of "the paroxysmal depolarizational shift" is defined. Role of some neurotransmitters in the mechanisms of epileptogenesis and their classifications into excitatory and inhibitory ones are also presented. It is pointed to a great variety of receptors for neurotransmitters as well as the role of calcium ions in mechanisms of epileptogenesis. A review of "classical" and new antiepileptic drugs is created and possible mechanisms of their effect are stated. The same antiepileptic medicaments are listed in a special table depending on the type of epilepsy in which they have effect. It is certain that during the last two decades electrophysiologic, biochemic and pharmacologic researchers have significantly improved the knowledge of the main occurrences responsible for epileptogenesis. However, a lot of facts are still doubtful.

Segmentation of 2-D and 3-D objects from MRI volume data using constrained elastic deformations of flexible Fourier contour and surface models

This paper describes a new model-based segmentation technique combining desirable properties of physical models (snakes), shape representation by Fourier parametrization, and modelling of natural shape variability. Flexible parametric shape models are represented by a parameter vector describing the mean contour and by a set of eigenmodes of the parameters characterizing the shape variation. Usually the segmentation process is divided into an initial placement of the mean model and an elastic deformation restricted to the model variability. This, however leads to a separation of biological variation due to a global similarity transform from small-scale shape changes originating from elastic deformations of the normalized model contours only. The performance can be considerably improved by building shape models normalized with respect to a small set of stable landmarks (AC-PC in our application) and by explaining the remaining variability among a series of images with the model flexibility. This way the image interpretation is solved by a new coarse-to-fine segmentation procedure based on the set of deformation eigenmodes, making a separate initialization step unnecessary. Although straightforward, the extension to 3-D is severely impeded by difficulties arising during the generation of a proper surface parametrization for arbitrary objects with spherical topology. We apply a newly developed surface parametrization which achieves a uniform mapping between object surface and parameter space. The 3-D procedure is demonstrated by segmenting deep structures of the human brain from MR volume data.