The amylolytic activity of Ca-deficient pumpkin plants (Cucurbita pepo L.)

We studied the significance of actual accessibility of ions for presence of α-amylase in roots and cotyledons of young pumpkin plants. We considered α-amylases to be—in agreement with published data—amylolytic enzymes which lose their activity after being dialysed against EDTA or a dilute solution of hydrochloric acid and which can be reactivated by addition of Ca²⁺. N connection with activity and Ca²⁺ nutrition appeared in cotyledons; it did, however, in roots: Ca-deficient plants revealed after preparation either completely inactive enzymes or enzymes with slight activity. It was, however, possible to reactivate them by addition of Ca²⁺ during preparation. So, using polyacrylamide disc electrophoresis we present evidence for the appearence of amylase with typical characteristics for α-amylases of other sources. Its relative mobility was the same for isolates from both roots and cotyledons. Its biosynthesis was not dependent upon metal which is associated with enzyme. No conclusion can be drawn as to whether Ca-deficient α-amylases are activein vivo; therefore it was impossible to judge whether α-amylase activity is subject to feed-back regulation.     

Annotated chromosome counts of Czechoslovak plants (16–30) (Materials for “Flóra ČSSR”—2)

Chromosome counts of the following 15 taxa are given:Eupatorium cannabinum, Gypsophila fastigiata, Helianthemum grandiflorum subsp.obscurum, Helictotrichon desertorum subsp.basalticum, Impatiens parviflora, Inula hirta, Jurinea mollis, Kernera saxatilis, Lembotropis nigricans subsp.nigricans, Malva alcea subsp.excisa, Myosotis nemorosa, Otites pseudotites subsp.cuneifolia, Plantago atrata subsp.carpatica, P. atrata subsp.sudetica, Poa badensis. The chromosome numbers ofHelictotrichon desertorum (as subsp.basalticum) andPlantago atrata subsp.sudetica are given for the first time. Chromosome numbers differing from those previously known were found inJurinea mollis (2n=34 as compared to 2n=30) andKernera saxatilis (2n=14 as compared to 2n=16).Rhodax Spach (=Helianthemum L. p. p.) andOtites Adans. (=Silene L. p. p.) are considered as separate genera. Remarks on taxonomy, nomenclature and chorology are given for most of the taxa.     

Entwicklung des Moores Mokré Louky bei Třeboň im Postglazial (Paläoökologische Studie)

The origin, age and development of a mire deposit in the locality of the Mokré Louky meadows near T?eboň were ascertained by means of palaeoecological methods. The first minerogenic sediments originated in a depression at the turn of the Late-Glacial and the Holocene Periods. In the course of minerogenic sedimentation, the vegetational cover was formed by stands ofFilipendula. In the middle of the Pre-Boreal Period, the first organic sediments formed by reed plant communities were deposited in the area. In the course of the following periods, plant communities of mire and marshy meadows belonging to the associations of the classScheuchzerio-Caricetea fuscae predominated on the site. Stands of willow and alder trees were formed in some parts of the deposit most probably towards the end of the Atlantic Period, with their maximum development in the Sub-Boreal to Upper Sub-Atlantic Periods. Pollen analysis produced a more precise foundation for reconstructing the forest vegetation in the centre of the T?eboňská pánev Basin. A higher presence ofQuercus and a lower one ofFagus, as compared with the results of previous pollen analyses from the borders of the Basin, were ascertained. The palaeoecological analyses are supported by radiocarbon datings.     

Association of methylenetetrahydrofolate (MTHFR) and apolipoprotein E (apo E) genotypes with homocysteine, vitamin and lipid levels in carotid stenosis

The aim of the study was to investigate the association between methylenetetrahydrofolate (MTHFR) genotypes and levels of homocysteine (Hcy), folate, vitamin B12 and lipids as well as the association between apolipoprotein E (apo E) genotypes and levels of lipids in a Croatian healthy control group and a group of patients with > 70% carotid stenosis (CS). The study included 98 Croats, 38 patients with > 70% carotid stenosis and 60 age- and sex-matched controls. The MTHFR and apo E genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), Hcy by enzyme immunoassay, vitamins by immunochemiluminiscence, and lipids by spectrophotometric method. There was no difference between control subjects and CS patients in the distribution of C677T MTHFR genotypes (p=0. 786) and alleles (p=0.904), however, differences in the frequencies of apo E genotypes (p=0.012) and alleles (p=0.029) were statistically significant. The odds ratio for apo E 3/4 genotype was 3.93 (95% CI 1.23-12.61). Hyperhomocysteinemia (> or =15 micromol/L) was found in 11% of CS patients and 5% of control subjects. Total cholesterol, triglycerides, vitamin B12 and folate were statistically different in "all MTHFR genotypes" (p<0.001, p<0.01, p=0.044 and p=0.036, respectively), and in TC/TT (p<0.001, p=0.003, p=0.030 and p=0.032, respectively) groups. The levels of total cholesterol, LDL cholesterol and triglycerides in the apo E 3/3, and total cholesterol in the apo E 3/4 group yielded statistical difference. An association was found of apo E 3/4 genotype but not of MTHFR genotypes with the risk of CS. MTHFR and apo E affect blood lipid levels, which was statistically confirmed. An association was also recorded between hyperhomocysteinemia and patients with CS. Vitamin status in CS showed a statistically verified association with TC/TT MTHFR genotype. In the group of patients with TC/TT MTHFR genotype, lower vitamin B12 and higher folate values were recorded. The results of multiple logistic analysis showed that there was no statistical significance of Hcy levels (OR 2.403, p=0.334) or conventional vascular risk factors such as smoking habit (OR 0.505, p=0.149), age (OR 1.048, p=0.087) or sex (OR 2.037, p=0.112) in predicting CS.     

Do we need the "adolescent crisis" diagnosis?

The aim of the study was to examine patients in adolescent crisis at the beginning of treatment and after a period of 12 months in order to evaluate the relative diagnostic and therapeutic validity. The study included 153 Split University students in adolescent crisis; 90 of them were treated by counseling and 63 served as controls. For diagnosis, Hampstead index and Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM-IV) multiaxial evaluation were used, allowing a wider insight into personal functioning. The study sample was split in 7 significantly different diagnostic subgroups. The counseling-treated examinees had better personality functioning after 12 months, but did not differ significantly from the control group. Some of their single functions were more severely disturbed at the very beginning. Counseling is a valuable therapeutic and diagnostic tool for adolescent crisis. The assessment must evaluate the entire person, because looking at only one aspect, due to different development and its place, a wrong conclusion may be reached. The "adolescents crisis" entity is clinically relevant.     

Synapse formation and mRNA localization in cultured Aplysia neurons

mRNA localization and regulated translation provide a means of spatially restricting gene expression within neurons during axon guidance and long-term synaptic plasticity. Here we show that synapse formation specifically alters the localization of the mRNA encoding sensorin, a peptide neurotransmitter with neurotrophin-like properties. In isolated Aplysia sensory neurons, which do not form chemical synapses, sensorin mRNA is diffusely distributed throughout distal neurites. Upon contact with a target motor neuron, sensorin mRNA rapidly concentrates at synapses. This redistribution only occurs in the presence of a target motor neuron and parallels the distribution of sensorin protein. Reduction of sensorin mRNA, but not protein, with dsRNA inhibits synapse formation. Our results indicate that synapse formation can alter mRNA localization within individual neurons. They further suggest that translation of a specific localized mRNA, encoding the neuropeptide sensorin, is required for synapse formation between sensory and motor neurons.     

Antioxidant and antimutagenic activity of mannan neoglycoconjugates: mannan-human serum albumin and mannan-penicillin G acylase

The antioxidant and antimutagenic activity of the yeast cell-wall mannan and mannan conjugates--in particular the mannan of Saccharomyces cerevisiae (M-S.c.) and conjugates of mannan S. cerevisiae with human serum albumin (M-HSA1, M-HSA2) and the microbial enzyme penicillin G acylase (M-PGA)--were evaluated in vitro in the unicellular flagellate Euglena gracilis exposed to the genotoxic agents ofloxacin and acridine orange (AO). M-S.c., M-HSA1, M-HSA2 and M-PGA show a statistically significant, concentration-dependent protective antigenotoxic activity against both compounds. M-PGA was the most efficient inhibitor of ofloxacin- and AO-induced chloroplast DNA damage, whereas M-HSA2 and M-HSA1 were less effective and M-S.c. had the lowest antigenotoxic activity. It is suggested that different mechanisms may be involved in their protective effect--antioxidant activity in the case of ofloxacin-induced DNA damage and direct adsorption of AO on mannan conjugates as possible mechanisms of protection, based on spectrophotometric measurements. The important characteristics of yeast cell-wall mannans and mannan conjugates, such as their high water solubility, their broad spectrum of biological activity, low toxicity, stability and their antimutagenic effects via different modes of action, appear to be promising features for their practical application as antioxidants and antimutagenic agents.     

Development of a monoclonal antibody that specifically detects tissue inhibitor of metalloproteinase‐4 (TIMP‐4) in formalin‐fixed,paraffin‐embedded human tissues

Overexpression of the extracellular metalloproteinase inhibitor TIMP‐4 in estrogen receptor‐negative breast cancers was found recently to be associated with a poor prognosis for survival. To pursue exploration of the theranostic applications of TIMP‐4, specific antibodies with favorable properties for immunohistochemical use and other clinical assays are needed. Here we report the characterization of a monoclonal antibody (clone 9:4–7) specific for full‐length human TIMP‐4 with suitable qualities. The antibody was determined to be an IgG_2b immunoglobulin. In enzyme‐linked immunosorbent assay (ELISA) and immunoblotting assays, it did not exhibit any detectable crossreactivity with recombinant forms of the other human TIMPs 1, 2, and 3. In contrast, the antibody displayed high specificity and sensitivity for TIMP‐4 including in formalin‐fixed and paraffin‐embedded specimens of human breast specimens. An analysis of tissue microarrays of human cancer and corresponding normal tissues revealed specific staining patterns with excellent signal‐to‐noise ratios. This study documents TIMP‐4 monoclonal antibody clone 9:4–7 as an effective tool for preclinical and clinical investigations. J. Cell. Biochem. 110: 1255–1261, 2010. Published 2010 Wiley‐Liss, Inc.     

Mycophagous mites and their internal associated bacteria cooperate to digest chitin in soil

The greater bulk of soil nitrogen is immobilized in chitinous cell walls of fungi. Mycophagous soil mites participate in chitin decomposition and, hence, in the subsequent mobilization of nitrogen. The source of the chitinolytic enzymes was searched in this study. A multimethodical approach was designed for these studies. Histology, plating and identification of bacteria from mite homogenate and, finally, homogenate and bacterial treatment of the soil fungi were applied. Here the presence and activity of chitinolytic bacteria inside mycophagous mites are reported. These bacteria form an extraintestinal group within the mite’s body and pass their enzymes into the mite’s gut. Our results demonstrate that true mycophagous mites, defined by their ability to digest chitin (i.e. the fungal cell wall), achieve this through internal “cooperation” with chitinolytic bacteria that provide the necessary chitinolytic enzymes. The nitrogen from chitin is thus made available to other soil organisms and plants.