Importance of type specimen study for understanding genus boundaries-taxonomic clarifications in Lepidoderma based on integrative taxonomy approach leading to resurrection of the old genus Polyschismium

Type specimens of four species of Lepidoderma (Myxomycetes, Amoebozoa)-L. crassipes, L. neoperforatum, L. perforatum, and L. stipitatum-have been studied using an integrative approach including application of traditional taxonomy methods, i.e., morphological study under stereoscopic and compound microscopes, detailed analysis of micromorphological characters using scanning electron microscopy, and molecular analysis by way of Sanger sequencing of molecular markers (nuc 18S rDNA and elongation factor 1-alpha gene, EF1A). Results of the study revealed that L. crassipes is conspecific with L. tigrinum, L. stipitatum is a malformed specimen of Diderma floriforme, whereas L. perforatum and L. neoperforatum represent two well-defined morphologically and genetically separate species. Phylogeny of Physarales shows the polyphyletic character of the genus Lepidoderma. The type species of Lepidoderma clusters together with Diderma, whereas other representatives of this genus form a monophyletic, well-supported clade. The species from this clade are proposed to belong to the genus Polyschismium described by A. Corda in 1842 that is resurrected and emended here. Nine species of Lepidoderma are transferred to Polyschismium. A new key to Didymiaceae including Polyschismium is provided.

Didymium pseudonivicola: A new myxomycete from the austral Andes emerges from broad-scale morphological and molecular analyses of D. nivicola collections

A new nivicolous myxomycete is described as a result of a comprehensive study of Didymium nivicola collections from the entire range of its occurrence. Statistical analysis of 12 morphological characters, phylogenetic analyses of nuc 18S rDNA and elongation factor 1-alpha gene (EF1A), and a delimitation method (automatic barcode gap diversity) have been applied to corroborate the identity of the new species. A preliminary morphological analysis of D. nivicola revealed high variability of South American populations where four types of spore ornamentation were noted. However, results of molecular study and statistical analysis of morphological characters did not support recognition of these four forms but the distinction of two morphotypes. Consequently, two species have been recognized: D. nivicola and the newly proposed D. pseudonivicola. The new species can be distinguished from D. nivicola by distinctly larger and mostly plasmodiocarpic sporophores, which are scattered to gregarious, paler spores, and by the paler, more delicate and more elastic capillitium. Spore ornamentation of D. pseudonivicola is uniform and can be described as distinctly spiny (pilate under scanning electron microscope [SEM]), whereas those of D. nivicola is more variable, where spines (pilae under SEM) are delicate, distinct, or conspicuous. Additionally, whereas D. nivicola is a species distributed worldwide, D. pseudonivicola occurs only in the austral Andes of Argentina and Chile.

Range-wide Phylogeography of a Nivicolous Protist Didymium nivicola Meyl. (Myxomycetes, Amoebozoa): Striking Contrasts Between the Northern and the Southern Hemisphere

Soil protists play a crucial role in terrestrial ecosystems and often show immense taxonomic diversity. However, for many groups, distribution patterns remain largely unknown. We investigated range-wide intraspecific diversity of a specialized airborne protist (Didymium nivicola Meyl.) that occupies a narrow ecological niche associated with long-lasting snow cover. We sampled 122 collections covering all areas where the species was recorded worldwide. We obtained 105 and 41 sequences of small ribosomal subunit rDNA (SSU) and elongation factor 1-alpha (EF1A), respectively. While the species is very diverse in the austral Andes, Southern Hemisphere (SH; 17 SSU ribotypes and 12 EF1A genotypes identified), its populations are genetically uniform across three continents of the Northern Hemisphere (NH; single ribotype, single genotype). Our results indicate the austral Andes as a possible diversification centre for D. nivicola where populations seem to reproduce sexually. Two main parts of the range display highly contrasting genetic patterns, thus biogeographical history and dynamics. Current distribution of D. nivicola in the NH is likely a result of a dispersal event from the SH and subsequent long-distance dispersal (LDD) that might be associated with a shift to asexual mode of reproduction.

Nivicolous Trichiales from the austral Andes: unexpected diversity including two new species

Nivicolous myxomycetes are a group of amoebozoan protists dependent on long-lasting snow cover worldwide. Recent fine-scale analysis of species diversity from the austral Andes revealed high intraspecific variability of most taxa, suggesting independent evolutionary processes and significant differences in species compositions between the Northern (NH) and Southern (SH) Hemispheres. The present study is the second part of this analysis based on representatives of Trichiales. A total of 173 South American collections were studied based on morphological and molecular data, and 15 taxa have been identified. Two of them, Hemitrichia crassifila and Perichaena patagonica, are proposed as new species confirmed by a phylogeny of Trichiales. However, their affinity to the genera in which they are proposed are not confirmed due to polyphyletic character of all genera of Trichiales. Four species, Dianema subretisporum, Trichia contorta var. karstenii, T. nivicola, and T. sordida, are reported for the first time from the Southern Hemisphere. One species, T. alpina, is new for Argentina. Additionally, we provide the first record of Perichaena megaspora from Chile. Specimen frequency and species diversity of Trichiales found at nivicolous localities in the austral Andes are unexpectedly high, exceeding those of Stemonitidales, the most numerous group in the Northern Hemisphere, where Trichiales play a marginal role. By contrast, Trichiales appear the main component of nivicolous assemblages in the Andes. Results of the present work, together with the earlier analysis of Stemonitidales, indicate that the Andes constitute an exceptionally important evolutionary hot spot for nivicolous myxomycetes characterized by an outstanding species diversity.

New protocol for successful isolation and amplification of DNA from exiguous fractions of specimens: a tool to overcome the basic obstacle in molecular analyses of myxomycetes

Herbarium collections provide an essential basis for a wide array of biological research and, with development of DNA-based methods, they have become an invaluable material for genetic analyses. Yet, the use of such material is hindered by technical limitations related to DNA degradation and to quantity of biological material. The latter is inherent for some biological groups, as best exemplified by myxomycetes which form minute sporophores. It is estimated that ca. two-thirds of myxomycete taxa are represented by extremely scanty material. As DNA isolation methods applied so far in myxomycete studies require destructive sampling of many sporophores, a large part of described diversity of the group remains unavailable for phylogenetic studies or barcoding. Here, we tested several procedures of DNA isolation and amplification to seek for an efficient and possibly non-destructive method of sampling. Tests were based on herbarium specimens of 19 species representing different taxonomic orders. We assayed several variants of isolation based on silica gel membrane columns, and a newly designed procedure using highly reduced amount of biological material (small portion of spores), based on fine disruption of spores and direct PCR. While the most frequently used column-based method led to PCR success in 89.5% of samples when a large amount of material was used, its performance dropped to 52% when based on single sporophores. Single sporophores provided amplicons in 89.5% of samples when using a kit dedicated to low-amount DNA samples. Our new procedure appeared the most effective (94.7%) while it used only a small fraction of spores, being nearly non-destructive; it was also the most cost-effective. We thus demonstrate that combination of adequate handling of spore micro-disruption coupled with application of direct PCR can be an efficient way to circumvent technical limitations for genetic studies in myxomycetes and thus can substantially improve taxon sampling for phylogeny and barcoding. Additionally, this approach gives a unique possibility to apply both molecular and morphological assays to the same structure (sporophore), which then can be further stored as documentation.

Selective adsorption and determination of hexavalent chromium ions using graphene oxide modified with amino silanes

Novel adsorbents are described for the preconcentration of chromium(VI). Graphene oxide (GO) was modified with various amino silanes containing one, two, or three nitrogen atoms in the molecule. These include 3-aminopropyltriethoxysilane (APTES), N-(3-trimethoxysilylpropyl)ethylenediamine (TMSPEDA), and N1-(3-trimethoxysilylpropyl)diethylenetriamine (TMSPDETA). The resulting GO derivatives were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and energy-dispersive X-ray fluorescence spectrometry (EDXRF). Adsorption studies show that these GO based sorbents are highly selective for Cr(VI) in the presence of Cr(III) at pH 3.5. Although the amino silanes applied in modification of GO contain different numbers of nitrogen atoms, the maximum adsorption capacities of GO derivatives are very similar (13.3-15.1 mg·g-1). Such results are in accordance with spectroscopy studies which show that the amount of amino silanes attached to GO decreases in the order of APTES > TMSPEDA > TMSPDETA. The APTES-modified GO was applied to selective and sensitive extraction of Cr(VI) ions prior to quantitation by low-power EDXRF using the Cr Kα line. The Cr(VI) ions need not be eluted from the solid adsorbent. The method has a 0.17 ng·mL-1 detection limit, and the recovery is 99.7 ± 2.2% at a spiking level of 10 ng·mL-1. The method was successfully applied to the determination of Cr(VI) in water samples. Graphical abstractGraphene oxide adsorbents modified with various amino silanes are described for the preconcentration and speciation of trace and ultratrace levels of chromium ions.

Green approach for ultratrace determination of divalent metal ions and arsenic species using total-reflection X-ray fluorescence spectrometry and mercapto-modified graphene oxide nanosheets as a novel adsorbent

A new method based on dispersive microsolid phase extraction (DMSPE) and total-reflection X-ray fluorescence spectrometry (TXRF) is proposed for multielemental ultratrace determination of heavy metal ions and arsenic species. In the developed methodology, the crucial issue is a novel adsorbent synthesized by grafting 3-mercaptopropyl trimethoxysilane on a graphene oxide (GO) surface. Mercapto-modified graphene oxide (GO-SH) can be applied in quantitative adsorption of cobalt, nickel, copper, cadmium, and lead ions. Moreover, GO-SH demonstrates selectivity toward arsenite in the presence of arsenate. Due to such features of GO-SH nanosheets as wrinkled structure and excellent dispersibility in water, GO-SH seems to be ideal for fast and simple preconcentration and determination of heavy metal ions using methodology based on DMSPE and TXRF measurement. The suspension of GO-SH was injected into an analyzed water sample; after filtration, the GO-SH nanosheets with adsorbed metal ions were redispersed in a small volume of internal standard solution and deposited onto a quartz reflector. The high enrichment factor of 150 allows obtaining detection limits of 0.11, 0.078, 0.079, 0.064, 0.054, and 0.083 ng mL(-1) for Co(II), Ni(II), Cu(II), As(III), Cd(II), and Pb(II), respectively. Such low detection limits can be obtained using a benchtop TXRF system without cooling media and gas consumption. The method is suitable for the analysis of water, including high salinity samples difficult to analyze using other spectroscopy techniques. Moreover, GO-SH can be applied to the arsenic speciation due to its selectivity toward arsenite.

Suspended aminosilanized graphene oxide nanosheets for selective preconcentration of lead ions and ultrasensitive determination by electrothermal atomic absorption spectrometry

The aminosilanized graphene oxide (GO-NH2) was prepared for selective adsorption of Pb(II) ions. Graphene oxide (GO) and GO-NH2 prepared through the amino-silanization of GO with 3-aminopropyltriethoxysilane were characterized by scanning electron microscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. The batch experiments show that GO-NH2 is characterized by high selectivity toward Pb(II) ions. Adsorption isotherms suggest that sorption of Pb(II) on GO-NH2 nanosheets is monolayer coverage, and adsorption is controlled by a chemical process involving the surface complexation of Pb(II) ions with the nitrogen-containing groups on the surface of GO-NH2. Pb(II) ions can be quantitatively adsorbed at pH 6 with maximum adsorption capacity of 96 mg g(-1). The GO-NH2 was used for selective and sensitive determination of Pb(II) ions by electrothermal atomic absorption spectrometry (ET-AAS). The preconcentration of Pb(II) ions is based on dispersive micro solid-phase extraction in which the suspended GO-NH2 is rapidly injected into analyzed water sample. Such features of GO-NH2 nanosheets as wrinkled structure, softness, flexibility, and excellent dispersibility in water allow achieving very good contact with analyzed solution, and adsorption of Pb(II) ions is very fast. The experiment shows that after separation of the solid phase, the suspension of GO-NH2 with adsorbed Pb(II) ions can be directly injected into the graphite tube and analyzed by ET-AAS. The GO-NH2 is characterized by high selectivity toward Pb(II) ions and can be successfully used for analysis of various water samples with excellent enrichment factors of 100 and detection limits of 9.4 ng L(-1).

Mouse sarcoma L1 cell line holoclones have a stemness signature

Accumulating data suggest that cancers contain a fraction of cells called cancer stem cells (CSCs), that may be responsible for upkeep and relapses of disease. In experimental settings, CSCs are regarded as most effective at tumour initiation in in vivo assays. Since the first isolation of cancer stem cells from acute myeloid leukaemia in 1994, cancer stem cells have been identified in human solid tumours and they have also been found in the established cell lines, based on ability of CSCs to form in vitro colonies of a specific morphology, called holoclones. Our study examined the ability of a mouse sarcoma cell line, derived from a lung metastasis of a BALB/c mouse and established as a stably growing line (L1), to produce holoclones in vitro. We aimed to verify a stemness signature of the holoclone cells. The L1 cell line was found to form holoclone colonies in vitro, which were shown to contain a percentage of CSC-like cells. A fraction of the L1 cells was able to repopulate the original cell line, and presented an increased clonogenic and metastatic potential (18th passage). In addition, MTT assay and flow cytometry of the side population fraction revealed that these cells were more resistant to chemotherapeutic drugs than the original cell line, and over-expressed the anti-apoptotic genes, GRP78 and GADD153. We conclude that mouse L1 sarcoma cell line contains CSC-like cells.

Erythropoietin concentration in serum and cerebrospinal fluid of patients with amyotrophic lateral sclerosis

Erythropoietin (EPO) acts as a neuroprotective factor and is upregulated after neuronal injury. It has been reported that in cerebrospinal fluid (CSF) of amyotrophic lateral sclerosis (ALS) patients, the EPO concentration is decreased. In this study, EPO levels in serum and CSF of 30 patients with ALS and in 15 controls, using an ELISA technique, were estimated. EPO level in serum was decreased, especially in patients with bulbar onset ALS. A trend toward a progressive EPO decline with the duration of the disease in the mild + moderate ALS cases was observed. In severe cases, a tendency towards a positive correlation of EPO and duration of the disease was present. Serum EPO values were age related only in mild + moderate ALS in patients below 40 years of age. In CSF, the EPO levels were significantly decreased. Lower EPO values in the bulbar onset ALS when compared with the spinal onset ALS were present. The EPO decrease did not correlate with the severity and duration of the disease. Age relation of the EPO level only in the mild + moderate ALS cases more than 40 years was present. Lack of differences in EPO levels between patients with ALS of rapid and slow progression indicates that EPO concentration cannot be used as a prognostic factor. Nevertheless, the decreased serum and CSF EPO concentration and the known EPO neuroprotective action may indicate that EPO administration can be a new promising therapeutic approach in ALS.

Evaluation of matrix metalloproteinases in serum of patients with amyotrophic lateral sclerosis with pattern recognition methods

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases, which are present in central and peripheral nervous system. They are considered to be involved in the pathogenesis of several neurological diseases, as multiple sclerosis, Alzheimer disease, and amyotrophic lateral sclerosis (ALS). The aim of the present study was to evaluate the application of the pattern recognition methods for the assessment of MMPs in serum of patients with ALS. Thirty patients with amyotrophic lateral sclerosis (ALS), in two subgroups: (i) with mild and (ii) severe progressing ALS, and 15 control healthy subjects were studied. The metalloproteinases MT-MMP-1, MMP-2, MMP-9 were examined. Additional variables (age of subjects and disease duration) were also analyzed by using a standard, parallel and hierarchical classifiers. Our results indicate that: (i) MMP-2 in serum may be an important marker for the evaluation of ALS progress; (ii) the set of two features {MT-MMP-1, MMP-9} may be helpful in differentiation between ALS and healthy subjects; (iii) the error rates obtained for the pair-wise linear classifier were similar to those received for the classifiers (standard, parallel, and hierarchical) based on k-NN rule. We conclude that the pattern recognition methods may be useful for the evaluation of significance MMPs as markers in neurodegenerative diseases, such as ALS.

Matrix metalloproteinases and their tissue inhibitors in serum and cerebrospinal fluid of patients with amyotrophic lateral sclerosis

BACKGROUND AND PURPOSE

Matrix metalloproteinases (MMPs) are implicated in the pathogenesis of motor neuron degeneration in amyotrophic lateral sclerosis (ALS). We investigated the expression of MMPs and tissue inhibitors of matrix metalloproteinases (TIMPs) in serum and cerebrospinal fluid (CSF) correlating the results with age, disease duration and the clinical course.

METHODS

The material consisted of 30 ALS patients and 15 age-matched healthy controls. ELISA method to determine the expression of MT-MMP-1, MMP-2, MMP-9, TIMP-1 and TIMP-2 in serum and CSF was used. MMP-2 and MMP-9 by zymography was also tested.

RESULTS

In serum MT-MMP-1, MMP-2, MMP-9 and TIMP-1 expression was increased, especially in mild ALS cases. TIMP-2 values were normal. In CSF MT-MMP-1, MMP-2 and TIMP-1 level was either increased or normal, that of MMP-9 was decreased. TIMP-2 did not change. No correlation of MMPs and TIMP-1 expression in serum and CSF and the age of the patients was found. A correlation was observed between MMPs and TIMPs and disease duration.

CONCLUSIONS

Increased level of MMPs and TIMP-1 of ALS patients may reflect the degeneration process of motor neurons and skeletal muscles and/or is associated with tissues remodeling. The low level of MMP-9 in CSF may result from impaired balance between MMP-9 and TIMP-1 and/or its increased intrathecal degradation and physical clearance. Although the role of changed MMPs/TIMPs level in the pathogenesis of ALS is not clear their analysis in serum may be used as prognostic factor and a potential marker for monitoring treatment effects.

Single nucleotide polymorphisms in androgen-related genes and prostate cancer

21033

Background: Single nucleotide polymorphisms (SNPs) in genes encoding proteins involved in androgen metabolism were suggested to influence the individual prostate cancer susceptibility and clinical course of the disease. To examine this correlation in Polish population, we have developed a case-control study to analyze whether SNPs in CYP17 (+34T/C), SRD5A2 (V89L and A49T) and UGT2B15 (D85Y) genes may influence prostate cancer risk. These SNPs were also examined for their correlation with clinical features of prostate cancer at diagnosis and disease progression to hormone-refractory state. Methods: The genomic DNA was extracted from blood samples from 182 men with histologically confirmed prostate cancer and 217 healthy men, randomly chosen from population. SNPs analyses were performed with standard molecular methods. Results: The case-control study has revealed that 85YY and 85DY variants in UGT2B15 were more prevalent among patients (83%) than in the control group (73.3%; p=0.02; OR=1.78). The +34CC genotype in CYP17 was more frequent in patients with distant metastasis (30.4%) than in patients with organ confined (T1/T2) or locally advanced (T3/T4) disease (10.2% and 22.6%, respectively; p<0.05). This variant also correlated with higher PSA level at diagnosis. The 89LL variant in SRD5A2 was more common in patients with poorly differentiated prostate cancer (Gleason >6; 17.8%) than in men with well differentiated tumor (5.4%; p=0.033, OR=3.78). The 85YY variant in UGT2B15 was more prevalent in patients that developed hormone-refractory prostate cancer within two years from the beginning of androgen blockade (47.2% vs 23.3%, p=0.025, OR=2.95). Also the analysis of progression-free survival time on hormonal therapy for D85Y polymorphism yield significant results (p=0.041, Gehan's generalized Wilcoxon test). Conclusions: The D85Y polymorphism in UGT2B15 seems to influence prostate cancer risk in Polish population. The analyzed SNPs also correlated with clinical stage and PSA level at diagnosis (+34T/C in CYP17), tumor histological grade (V89L in SRD5A2) and response to hormonal therapy (D85Y in UGT2B15).

No significant financial relationships to disclose.

Effect of transfection with a gene coding for the fibronectin FNIII/10 fragment upon contact inhibition of C3H10T1/2 fibroblasts

The density-dependent growth inhibition of non-transformed cells may be associated with inefficient transduction of the proliferative signal from cell adhesion molecules. To verify this concept, the C3H10T1/2 fibroblasts were stably transfected with the gene coding for the fibronectin fragment III/10 (FNIII/10). This resulted in differences in gene's expression between original C3H10T1/2 cells and their FNIII/10 transfectants. No significant differences in growth properties were observed in the original or in the transfected cells. C3H10T1/2 cells and their transfectants, when co-cultured, displayed more cells at confluence than the cells cultured alone. Moreover, co-cultured C3H10T1/2 cells and their transfectants showed elevated levels of phospho-ERK1/2 compared to homogenous cultures. Results obtained indicate that cellular homogeneity is responsible for density-dependent growth inhibition.

Cellular quiescence induced by contact inhibition or serum withdrawal in C3H10T1/2 cells

Either confluence or serum withdrawal may cause growth arrest of cultured non-transformed cells. Here, we compared sparsely populated and confluent C3H10T1/2 cells with and without serum-containing medium. The following proliferation-relevant end points were examined: cell-cycle distribution, Ki-67 antigen presence, the level of the von Hippel-Lindau (VHL) protein, and gene expression, determined using a microarray approach. In sparse/logarithmic cultures, the fraction of cells in G(0)/G(1) phase increased from 55 to 85% following serum withdrawal. Moreover, the fraction of Ki-67 positive cells dropped from 89 to 47%. In confluent cultures, the majority of cells (80%) were in G(0)/G(1) phase and only 25-30% were Ki-67 positive, regardless of serum presence. In both serum-deprived and contact-inhibited cultures, significant and distinct changes in gene expression were observed. Serum deprivation of sparsely cultured cells resulted in significant over-expression of several transcription factors, while confluent cells showed elevated expression of genes coding for Wnt6, uPar, Tdag51, Egr1, Ini1a and Mor1. These results indicate that contact inhibition and serum withdrawal lead to cellular quiescence through distinct genetic and molecular mechanisms.

Serum IgM anti-GM1 ganglioside antibodies in lower motor neuron syndromes

Lower motor neuron syndromes (LMNS) are heterogenous conditions, which include patients with progressive lower motor neuron disease (LMND) and cases with the clinical phenotype of motor neuropathy (MN). The aim of this study was to estimate the IgM anti-GM1 ganglioside antibodies titer and the ratio of the light chains in order to define the presence of autoimmunity process in particular cases with LMNS. Twenty-eight patients were diagnosed with LMND and 15 patients were diagnosed with MN (10 patients with multifocal motor neuropathy with conduction block, five patients with MN without conduction block). Total of 103 patients with classical amyotrophic lateral sclerosis (ALS) and 50 healthy, age-matched persons were also tested. The IgM anti-GM1 ganglioside titer and the ratio of lambda/kappa light chains in serum were determined using the ELISA technique. High titer of IgM anti-GM1 antibodies were detected in serum of 46% LMND patients, 80% of MN patients, and 18% of the classical ALS cases. An elevated ratio of lambda/kappa light chains appeared in 18% of LMND patients, and in 67% of the MN cases. The lambda/kappa light chains ratio was normal in all ALS patients. The presence of elevated titer of IgM anti-GM1 ganglioside antibodies and the changed ratio of the light chains supports the presence of autoimmune process in LMNS and may provide clues for their management.

Effect of Riluzole on serum amino acids in patients with amyotrophic lateral sclerosis

OBJECTIVES

There is evidence that an imbalance between glutamatergic and inhibitory neurotransmission may contribute to selective neurodegeneration in amyotrophic lateral sclerosis (ALS). The efficacy of Riluzole in prolonging the survival of patients with ALS has been demonstrated in two large controlled trials. It is believed that Riluzole is a glutamate antagonist, but the exact mode of its action is not known. Data on the effects of Riluzole treatment on excitotoxic amino acid levels in serum are not available.

MATERIAL AND METHODS

We prospectively studied 17 patients with ALS (diagnosed according to the El Escorial criteria), who received long-term treatment with Riluzole (100 mg/day). The subjects were evaluated at baseline (before treatment) and after 6, 12 and 18 months on drug. Assessments included the functional status of the patients and serum levels of amino acids. Analysis of the serum amino acids was performed using high performance liquid chromatography techniques at baseline, and after 6, 12 and 18 months of the treatment.

RESULTS

At baseline, glutamate, GABA and total amino acid concentration in serum of the ALS patients, mainly in those with severe course of the disease, were increased. During the first 6 months of Riluzole treatment there was a significant decrease of glutamate and total amino acids, afterwards the values returned to the initial high values, or even an 'overshooting' in their levels appeared. We did not observe a similar effect of Riluzole on glutamate and other amino acids in patients with less advanced ALS.

CONCLUSIONS

It is suggested that the positive clinical effect of Riluzole in ALS patients may be related, at least partly, to its influence on amino acid metabolism in neural tissues.

Glassy and fluidlike behavior of the isotropic phase of n-cyanobiphenyls in broad-band dielectric relaxation studies

It is shown that the temperature behavior of peaks f p, of dielectric loss curves in the isotropic phase of n-cyanobiphenyls n = 8, 9, 10 with isotropic-nematic and isotropic-smectic A transitions exhibits features characterisic for both supercooled, glass-forming liquids and critical, binary mixtures. The behavior of f p T can be portrayed by the Vogel-Fulcher-Tamman relation and the "critical-like", mode-coupling theory (MCT) equation. The latter is supported by the novel analysis of electric conductivity σ T . The obtained f p T and σT dependencies can be related by using the fractional Debye-Einstein-Stokes law. For all tested mesogens the static dielectric permittivities ɛ(') T and T are described by dependencies resembling those applied in the homogeneous phase of critical mixturesbut with specific-heat critical exponent α≈ 0.5. This behavior agrees with the novel fluidlike description for the isotropic-nematic transition (P.K. Mukherjee, Phys. Rev. E 51, 5745 (1995); A. Drozd-Rzoska, Phys. Rev. E 59, 5556 (1999)). The obtained glassy features of dielectric relaxation support the recent simulation analysis carried out by M. Letz et al.Phys. Rev. E 62, 5173 (2000)).

[Neurotoxic activity of serum and cerebrospinal fluid of amyotrophic lateral sclerosis patients against some enzymes of glutamate metabolism]

One of the hypotheses in amyotrophic lateral sclerosis (ALS) indicates on excitatory amino acids as the cause of neuronal death. Changes in their concentration in the tissues and body fluids may be the consequence of a defect in their transport, as well as abnormal activities of glutamate metabolizing enzymes. Abnormal synthesis/degradation of these enzymes and/or influence of activators/inhibitors should be taken into account. The activity of enzymes of glutamate metabolism of rat spinal cord in vitro in the presence of serum and cerebrospinal fluid (CSF) of 20 patients with ALS and 20 healthy controls was tested. In the presence of serum of the ALS patients glutaminase was significantly stimulated, instead of being inhibited; the inhibition of GABA aminotransferase, glutamate decaboxylase and aspartate aminotransferase was less evident than in the controls, glutamate dehydrogenase lost its activity more than in control conditions, the inhibition of glutamine synthetase was comparable to that when normal serum was applied. The activity of the enzymes in the presence of CSF of ALS patients was generally similar to that of normal CSF, except of glutaminase which was stimulated and GABA aminotransferase, which was inhibited stronger than in the presence of normal CSF. This study indicates, that changes in glutamate concentration in tissues and body fluids in ALS may be caused, at least partly, by abnormalities in the activity of glutamate metabolism enzymes, which are in turn induced by neurotoxic agents present in body fluids of ALS patients.

[The effect of selegiline and vitamin E in the treatment of ALS: an open randomized clinical trials]

A role for oxidative stress in the etiology or progression of amyotrophic lateral sclerosis (ALS) and other neurodegenerative diseases has been recently proposed. We conducted the 18-month, randomized treatment trial with oral vitamin E (600 IU daily) and selegiline (10 mg daily) in 67 patients with sporadic ALS. Thirty five patients were randomly assigned to receive antioxidative therapy (vitamin E plus selegiline) and the remaining 32 patients were the ALS controls who received symptomatic treatment. The primary end point was survival and functional status. At the end of 18-month study, 13 patients in the treatment group and 14 in the control group died or were tracheostomized. A decline in functional disability was also similar in both groups. Long-term antioxidative treatment did not benefit patients with ALS.

[The role of mitochondrial respiratory chain in the pathogenesis of ALS]

Mitochondrial dysfunction and abnormal electron chain transport (ECT) may be involved in the pathogenesis of ALS. The aim of this study was to investigate the effect of cerebrospinal fluid (CSF) from ALS patients on the activity of ECT enzymes in mitochondrial cerebral crude preparations in the rats. We found that CSF inhibited the activity of complex I-III in 20%, complex II-III in 12% and complex IV in 33% of the ALS patients. CSF from the controls did not affect the activity of complex I-III and II-III. The effect of the CSF ultrafiltrates with cut off below 5000 daltons on the activity of ECT enzymes was also investigated. The CSF ultrafiltrates inhibited the activity of complex I-III, complex II-III and complex IV in 38%, 44% and 53% of the ALS patients, and in 80%, 53% and 43% of the controls, respectively. The results of this study and our previously reported experiments on the sera of ALS patients may indicate that neurotoxic effects of body fluids from ALS patients could be mediated by inhibition of the respiratory chain enzymes. This confirms an important role of mitochondrial dysfunction in the pathogenesis of ALS.

Signal transduction in confluent C3H 10T1/2 cells. The role of focal adhesion kinase

The activities of extracellular signal-regulated kinases (ERK1/ERK2) is required for proliferation of several types of cells. The performed analysis showed stimulation of ERK's by fetal calf serum (FCS) or fibronectin in the C3H 10T1/2 cell cultures at logarithmic phase of growth. The ERKs activity was not stimulated in confluent cells. This could not be accounted for a partial down regulation of ERK since its level was stable in both types of cells regardless of their density and kind of stimulation. Searching for ERK up-stream elements we studied the integrin receptor gene transcript by RT-PCR and focal adhesion kinase (FAK) by Western blotting and phosphorylation assays. It was found that FCS and fibronectin stimulated phosphorylating activity of FAK in the cells at the logarithmic phase of growth, but were inefficient in the confluent cells. RT-PCR showed the presence of alpha5 and beta1 integrin transcripts, and p125FAK was at the same level regardless of the type of stimulation. These data indicate that the ability of FAK to be activated plays an important role in ERK regulation and, in consequence in proliferation and growth inhibition during confluence.

In vitro and in vivo study of the expression vector encoding vascular endothelial growth factor

Vascular endothelial growth factor (VEGF) is an angiogenic cytokine with potential therapeutic applications in human diseases. It is a mitogen primarily for endothelial cells. The transfer of the cDNA encoding VEGF to ischemic tissues, which cannot be revascularized otherwise, represents a novel and promising approach to the treatment of vascular disorders. In this work the VEGF165 cDNA was cloned into the expression vector pSecTag2B. The activity of the construct was studied in cell culture as well as in vivo. Western blotting study showed that the cells transfected with the vector secreted significantly higher amounts of VEGF to the culture medium than the non-transfected cells. In vivo study revealed an increased number of new vessels in animals injected with vector encoding VEGF as compared with empty plasmid. Also, tumor cells transfected with the VEGF plasmid exhibited extensive vascularization.

Peptide analog of fibronectin that inhibits cell migration and ERK 1/2 activity

Two analogs of the peptide mimicking the 1977-1991 C- terminal part of fibronectin have been synthesized and tested. AWLI simulated human fibronectin fragment 1977-1991, whereas AWLII hybridized to both RGD and 1977-1991 fragments. AWLI and AWLII peptides inhibited the migration of the ovarian carcinoma cell line OVP10 regardless of the presence RGD. AWLI peptide inhibited spontaneous and fibronectin-activated cell migration and ERK1/2 activity. Neither AWLI nor fibronectin induced changes in FAK proteins, as could be judged from Western blots. In conclusion, it seems that the C-terminal fragment of fibronectin inhibits ERK1/2-dependent (random) migration of ovarian carcinoma cells.

Low-frequency dielectric relaxation in rubber

A rubber sample is investigated by dielectric spectroscopy in the frequency range from 10(-2)<or=nu<or=10(7) Hz. Measurements are performed under both isothermal (at ambient pressure) and isobaric conditions. The spectral shape of the loss peaks is symmetric and temperature and pressure independent. Hence the temperature-pressure-frequency superposition principle is fulfilled in a cross-linked rubber sample. The Vogel-Fulcher-Tammann temperature law and its pressure counterpart well describe the respective temperature and pressure dependences of relaxation times. In addition we determined the activation volume from isothermal relaxation data.

KDR promoter can transcriptionally target cytosine deaminase suicide gene to cancer cells of nonendothelial origin

The KDR/flk-1 gene promoter is considered to be endothelial cell-specific. We show its activity in two cancer cell lines of non-endothelial origin: in murine L1 sarcoma and OVP-10 human ovarian carcinoma cell lines. KDR promoter-driven cytosine deaminase gene can be efficiently expressed in these cells leading to sensitization to 5-fluorocytosine, as demonstrated both in vitro and in vivo. Our results indicated that KDR promoter activity is not endothelial cell-exclusive and that this promoter can also be used to obtain specific expression of therapeutic genes in certain cancer cells.

Caffeine-inhibitable control of the radiation-induced G2 arrest in L5178Y-S cells deficient in non-homologous end-joining

The two L5178Y (LY) sublines bear a heterozygous Tp53 mutation that affects its transactivation function. LY-S (radiation-sensitive) cells are deficient in double strand break (DSB) repair by non-homologous end-joining (NHEJ) and do not express p21WAF1 (Cdkna1) either constitutively or after x-irradiation, in contrast to their radiation-resistant counterpart LY-R cells, which express p21WAF1 constitutively. Radiation-induced G2 arrest in LY-S cells is very long (11 h/Gy) but 2 mM caffeine treatment shortens it, decreases the fraction of G2 cells and increases the fraction of apoptotic cells. The treatment also increases the DNA damage that is estimated with the comet assay 18 h after irradiation with 5 Gy (ca. 23% of the initial value for x-rays and ca. 47% for x-rays plus caffeine). This indicates that either the repair has not been completed or the apoptotic DNA fragmentation has been initiated (or both). The same treatment applied to x-irradiated (5 Gy) LY-R cells (G2 arrest, 4 h/Gy) has no radiosensitising effect, induces no apoptosis and does not alter the amount of DNA damage left unrepaired (ca. 28%). The results are compatible with the assumption that inhibition of the Atm-dependent homologous recombination repair by caffeine, brings differential effects in LY sublines because of the defect of the alternative DNA repair system (NHEJ) in LY-S cells.

Signal transduction in confluent C3H 10T1/2 cells. The role of focal adhesion kinase

The activities of extracellular signal-regulated kinases (ERK1/ERK2) is required for proliferation of several types of cells. The performed analysis showed stimulation of ERK's by fetal calf serum (FCS) or fibronectin in the C3H 10T1/2 cell cultures at logarithmic phase of growth. The ERKs activity was not stimulated in confluent cells. This could not be accounted for a partial down regulation of ERK since its level was stable in both types of cells regardless of their density and kind of stimulation. Searching for ERK up-stream elements we studied the integrin receptor gene transcript by RT-PCR and focal adhesion kinase (FAK) by Western blotting and phosphorylation assays. It was found that FCS and fibronectin stimulated phosphorylating activity of FAK in the cells at the logarithmic phase of growth, but were inefficient in the confluent cells. RT-PCR showed the presence of alpha5 and beta1 integrin transcripts, and p125FAK was at the same level regardless of the type of stimulation. These data indicate that the ability of FAK to be activated plays an important role in ERK regulation and, in consequence in proliferation and growth inhibition during confluence.

Radiosensitivity of HCV cells and their v-ras and v-raf transfectants

In the present work, it was found that transfection of cultivated urothelial cells HCV-29 with v-raf and v-ras oncogenes increased their sensitivity to ionizing radiation, as documented by clonogenic studies. Flow cytometry study showed, that HCV-29 and their v-ras transfectants were arrested around middle S phase, whereas v-raf transfectants randomly at each point of S phase. This unusual reaction of HCV-29 v-raf cells may partially explain studies of P21(WAF1/CIP1) and GADD45 genes, whose transcripts were found only in these cells. Increased radiosensitivity of v-ras transfectants is probably associated with c-JUN protein overexpression. Altogether the obtained results suggested different mechanism of reaction on irradiation of v-raf and v-ras transfected cells.

Adenosine receptor antagonism causes inhibition of angiogenic activity of human ovarian cancer cells

Angiogenesis, new blood vessels development, is an important process involved in ovarian cancer growth and metastasis. Adenosine is a known mediator of angiogenesis in hypoxic tissues. Theobromine, adenosine receptor antagonist, exerts antiangiogenic properties in many types of tumors in Balb/c mice cutaneous angiogenesis assay. The aim of the present study was to evaluate the mechanism of its action. We showed that theobromine inhibits angiogenic activity of ovarian cancer cells as well as CD45 positive lymphocytes isolated from peritoneal ascitic fluid of ovarian cancer patients. Using synthetic adenosine receptor antagonists: 8-phenyl-theophylline and 8-cyclopentyl-1,3 dipropylxantine we established that antiangiogenic properties of theobromine are dependent on its interaction with A2 adenosine receptor. Our observations were confirmed in full suspensions of ascitic cells as well as in isolated cancer cells and CD45 lymphocytes. We postulate that A2 receptor antagonism may diminish angiogenesis induced by hypoxia in different cancer tissues and may find a place in future cancer therapy.

Increased activity of MAP, p70S6 and p90rs kinases is associated with AP-1 activation in spontaneous liver tumours, but not in adjacent tissue in mice

Growth factor-responsive protein kinases regulate expression of genes involved in cell cycle control, cell proliferation and differentiation. To better understand the role of these kinases in the abnormal proliferation of malignant cells, we examined basal and epidermal growth factor (EGF)-inducible mitogen-activated protein kinase (MAPK), p70S6k and p90rsk activities in spontaneous hepatocellular neoplasms (adenomas and carcinomas) from CBA-T6 mice and in L1 sarcoma tumours implanted in livers of BALB/c mice. In spontaneous and implanted hepatic tumours, basal cytoplasmic and nuclear MAPK, p70S6k and p90rsk activities were significantly higher compared to the activities found in the part of the liver uninvolved by the tumour. Interestingly, the activities of these enzymes in the uninvolved tissue of the livers harbouring the tumour were higher compared to the livers from control mice. Basal kinase activities correlated with tumour morphology; they were lower in adenomas than in carcinomas and sarcomas. In contrast to basal activities, EGF-triggered kinase responses in normal livers and hepatic tumours were indistinguishable. Activating protein-1 (AP-1) DNA-binding activity was detected in tumours but not in the adjacent tissues. Constitutively activated kinases and AP-1 transcription factor found in hepatic malignancies are reminiscent of cells activated by EGF, suggesting that EGF and its intracellular effectors play a role in these malignancies.

Signal transduction in adherent and non-adherent human cell lines after fibronectin stimulation

It is shown that adherent and non-adherent human ovarian carcinoma cells (OVP 10) secrete MMPs and their production was stimulated by fibronectin as documented by gelatinise zymography. These cells also presented an increase of ERK phosphorylating activity following fibronectin stimulation, regardless of their adhesion. Contrary to OVP 10 cells, the human urothelial cells (HCV-29) are more anchorage-dependent. They only secreted the MMPs under adherent conditions and they revealed a lower level of basal and fibronectin stimulated ERK phosphorylation activity. In addition, non-adhering HCV-29 cells showed post translational down-regulation of focal adhesion kinase.

Anti-neural antibodies in serum and cerebrospinal fluid of amyotrophic lateral sclerosis (ALS) patients

OBJECTIVES

An autoimmune basis has been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). This hypothesis is supported by the presence of antibodies that interact with motoneuron antigens in serum of these patients. Against autoimmunity are the discrepances in the frequency of the antibodies appearance and also failure of immunosuppression. The aim of our study was to evaluate the titer of antibodies against GM1-gangliosides, AGM1-gangliosides and anti-sulfatides in paired serum and cerebrospinal fluid samples in the ALS patients.

MATERIAL AND METHODS

Serum of 103 and CSF of 79 patients with ALS was examined. The "disease controls" consisted of 22 cases of other motor neuron diseases and 50 healthy, age-matched normals. CSF was drawn at the same time from 79 ALS patients, 6 cases of the "disease controls" and 50 normals. To study the titer of antibodies against GM1-gangliosides, AGM1-gangliosides and sulfatides the ELISA technique has been applied.

RESULTS

An increased titer against GM1-gangliosides, AGM1-gangliosides and sulfatides in ALS appeared in serum in 18%, 32%, and 11%, resp., in the "disease controls" the increased antibodies titer appeared in single cases. In CSF the appropriate values in ALS were 20%, 15%, 8%, resp. In the "disease controls" a high antibodies titer was a rare finding.

CONCLUSIONS

It is concluded that in some ALS cases and also in some patients with other motor neuron diseases an autoimmune mechanism may contribute to motor neuron injury.

Amino acids acting as transmitters in amyotrophic lateral sclerosis (ALS)

OBJECTIVES

In amyotrophic lateral sclerosis (ALS), a neurodegenerative disease of unknown origin, excitotoxic mechanisms are supposed to be involved. Divergent results are, however, presented either because of the heterogeneity of this disease, and/or different methodologies used to evaluate the excitotoxic amino acids content. The results of the most sensitive high performance liquid chromatography (HPLC) techniques with precolumn derivatization of fasting serum and CSF glutamate, aspartate, glycine and gamma-aminobutyric acid (GABA) in mild and severely progressing ALS cases are presented here.

MATERIAL AND METHODS

We studied 25 ALS patients with different course of the disease and controls, which consisted of 10 cases with other motor neuron diseases and 20 healthy, age-matched subjects.

RESULTS

In the ALS patients with a mild course of the disease serum glutamate and aspartate content was either normal or slightly decreased, in all of these cases a rise in GABA and glycine was present. In the severely progressing ALS cases serum glutamate and aspartate was increased. The GABA content was either normal or increased, the glycine level appeared to be either normal or decreased. In CSF the amino acids changes in ALS were less pronounced as compared to serum. The most frequent finding was the increase in GABA concentration both in the mild and the severely progressing group. CSF glutamate in ALS patients with mild course of the disease was decreased, in the severely progressing cases the glutamate level appeared in a broad range from decreased to increased values. CSF aspartate was either normal or elevated, glycine values were present in a broad range from decreased to increased values. In the other tested motor neuron diseases no consistent changes in serum and CSF amino acids concentration was observed.

CONCLUSIONS

The data from serum and CSF indicate that in ALS an imbalance between excitatory and inhibitory amino acids might be present in the brain, which may be induced in different ways in particular ALS patients. It may be an important factor for the mediation of neurons death.

[Hyperkalemic periodic muscle paralysis in primary adrenocortical insufficiency. A case report]

20-years old man was admitted to the hospital because of a few paroxysmal muscle paralysis episodes with pronounced periodic hiperkalemia (maximal 9.8 mmol/l). The first episode was preceded by a very hard physical effort. Primary adrenal insufficiency was recognised on the basis of clinical, humoral and biochemical examinations. There was elevated ACTH and a very low serum level of cortisol and aldosterone. There was slight metabolic acidosis and hiponatremia. The patient was treated with hydrocortisone and fludrocortisone acetate (Cortineff) with positive result. During one year of this therapy his general condition was very good and clinical, humoral and biochemical signs (except of metabolic acidosis) resolved. Neurological symptoms and a very high serum kalium level were the most important signs of primary adrenal insufficiency in the presented case.

Immunochemical quantification of glycoconjugates in serum and cerebrospinal fluid of amyotrophic lateral sclerosis patients

Glycoconjugates in the serum of 73 patients with amyotrophic lateral sclerosis (ALS), 21 cases of other motor neuron diseases and 20 healthy controls were determined. Cerebrospinal fluid (CSF) was studied in 64, 7 and 10 of these subjects, respectively. The level of sialic acid containing glycoconjugates, detected by Maakia amurensis agglutinin (MAA), was decreased in the serum of 61.6% of the ALS patients, while in the CSF it was decreased, on average, in 75% of these cases. Only in single ALS cases was the concentration of these glycoconjugates increased. There was no correlation between the content of MAA-labelled glycoconjugates both in serum and CSF and the titre of sialic acid containing anti-GM1 gangliosides. The glycoconjugates, detected by peanut agglutinin (PNA) which recognizes the disaccharide galactose beta(1-3)N- acetylgalactosamine (GGN), were decreased in the serum of 78.1% of ALS patients, while in CSF they were increased in 54.7% of these cases. There was no correlation between the concentration of PNA-labelled glycoconjugates both in serum and CSF as well as the titre of antibodies against GGN-containing anti-GM1 and anti- AGM1 gangliosides. Changes in the level of the MAA- and PNA- labelled glycoconjugates, as well as the titre of anti-GM1 and anti-AGM1 gangliosides antibodies were not specific for ALS. They were also observed in some cases of other motor neuron diseases. The low level of the lectin-labelled glycoconjugates in serum and partly in CSF of the majority of ALS patients is possibly the consequence of their accelerated clearance and/or specific inactivation by the formation of immune complexes or epitope binding. Degeneration of neurons and muscle cells could also be responsible. The relatively low incidence of high anti- glycolipids antibodies titre may be, at least partly, connected with the low concentration of the appropriate antigens. The increased content of PNA-labelled glycoconjugates in the CSF of the majority of ALS patients, together with the low incidence of high titre of antibodies against the appropriate glycolipids, could indicate that in CSF this lectin binds to the GGN epitope of glycoproteins rather than to the GGN epitope of glycolipids.

Inhibitory effect of theobromine on induction of angiogenesis and VEGF mRNA expression in v-raf transfectants of human urothelial cells HCV-29

Neovascularisation plays a crucial role in solid tumor growth and metastasis formation. Our previous studies showed that theophylline and theobromine suppressed cutaneous neovascular reaction induced in mice by human blood leukocytes, and lung as well as ovarian cancer cells. Here, we investigated the in vivo effect of theobromine on angiogenic activity of human urothelial cell line HCV-29, v-raf transfected (mouse cutaneous assay), and the in vitro effect of this drug on VEGF, tPA, uPA and PAI mRNA expression in these cells (RT-PCR method). Theobromine suppressed angiogenesis induced in mice by HCV-29-v-raf cells, inhibited VEGF mRNA expression, and had no effect on transcription of uPA and tPA in these cells. HCV-29-v-raf transfectants do not display transcripts of PAI, in the presence or the absence of theobromine.

[Intracerebral hemorrhage following amphetamine use]

We describe a young male who suffered intracerebral hemorrhage (ICH) following nasal use of amphetamine. He recovered completely within several weeks of hospitalization. Angiography and MRI did not reveal vascular malformation and therefore we suspect that the ICH in our patient may be attributed to the effect of amphetamine alone.

Angiogenesis induced by urothelial cells (HCV-29) and their v-ras and v-raf transfectants

The angiogenic ability of human urothelial cells (HCV-29) and their v-ras and v-raf transfectants was studied. The most pronounced angiogenesis, observed in vivo, induced v-raf-transfected cells. The lowest degree of induction of neovascularization presented cells of the parental line. The increased extent of angiogenesis correlated with the presence of VEGF mRNA as measured by RT-PCR as well as the level of VEGF as visualized by the method of Western blotting.