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[
Phytochemistry,
2002]
Multiple molecular forms of inhibitors of trypsin (TI) and chymotrypsin (CI), which are typical digestive enzymes of insects, mammals and micro-organisms, and subtilisin (SI), a proteinase of many bacteria and phytopathogenic fungi, were identified in seeds and vegetative organs of the majority of 128 wild and cultivated species representing 65 genera of three of the subfamilies of the Compositae. Inhibitors with M(r) ranging from 7450 to 7800 and combining activities towards subtilisin and trypsin and/or chymotrypsin (T/C/SI) had the widest distribution and may be involved in plant defense mechanisms. They were found in many species of the subfamilies Carduoideae (genera Carthamus, Centaurea, Cirsium), Cichorioideae (Lactuca, Taraxacum) and Asteroideae (Helianthus, Cosmos, Bidens). Partial amino acid sequencing showed that the safflower (Carthamus tinctorius) T/C/SI and Cosmos bipinnatus T/C/SI, T/SI and C/SI belonged to the potato I inhibitor family. The most active, variable and heterogeneous inhibitors were found in species of the tribe Heliantheae, which is placed in the evolutionary advanced subfamily Asteroideae. Seeds of Helianthus species, Eclipta prostrata, Gailardia aristata, Zinnia elegans and Silphium perfoliatum contained various TI with M(r) ranging from 1500 to 14,750, with some also containing SI. H. annuus seeds contain a unique cyclic TI of M(r) 1514 and similar TI were also present in other Helianthus spp. and the related species Tithonia diversifolia. Zinnia elegans contained a TI with M(r) 11,350 which appeared to represent a novel type of inhibitor distantly related to the cereal subgroup of Bowman-Birk inhibitors. TI and T/SI varied widely in H. annuus lines and wild Helianthus species in their presence or absence and composition. Similar T/SI components were found in the cultivated diploid H. annuus and annual diploid species with the B genome but not in perennials with the A genome. Some T/SI, SI and TI were detected in vegetative organs of sunflower and other Compositae. Studies of the polymorphism and distribution of proteinase inhibitors are relevant to the evolution of protective protein systems and the mechanisms of resistance to pathogenic organisms in the Compositae and other plants.
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[
J Infect Dis,
2003]
The induction of pathological changes in Onchocerca volvulus infections is directly related to the presence of the microfilarial stage of this filarial nematode. Patients with either of the 2 major forms of the clinical disease (i.e., asymptomatic/mild [n=12] and severe [n=16] dermatopathology) were studied. The cellular immune responses (cell proliferation) of those with severe disease were stronger (stimulation index [SI], 12.3+/-1.9) than those with mild dermatopathological effects (SI, 2.9+/-0.6) or control patients (SI, 4.5+/-0.4). Cytoadherence antibody responses were greatest (grade 4) in the clinically severe group and only weak (grades < or = 1) in the mild group or the control patients. Ivermectin treatment was followed by an increase in immune responsiveness in those with initially poor responses. Thus, the degree of dermatopathological effect is related to the host's immune response against microfilariae, and ivermectin augments such responses.
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J Comput Biol,
2019]
Quantitative analysis based on three-dimensional differential interference contrast (DIC) images is currently the mainstream in analyzing gene functions involved in early cell fate specifications. Segmentation and registration are the two most important steps in analysis. Many image segmentation methods have poor performance on embryonic DIC images because of the interference of egg shells, blurs, and nonuniform intensity background. A novel segmentation method is presented based on the shape index (SI) of local intensity variation in DIC images. To compute the SI, the intensity values of a local neighborhood are regarded as z coordinates over x-y planes. After calculating the SI for each pixel by evaluating the shape of intensity surface over the corresponding local neighborhood, SI thresholding is used to detect cytoplasm granules within embryonic boundaries. As a scalar and rotation invariant, the SI is both insensitive to directional changes and different ranges of intensity variations. Embryonic registration methods are usually based on the orientation of vertebrate anteroposterior (AP) axes computed from segmented embryonic boundaries. Due to the blur of marginal slices in DIC images, usually the segmented boundaries are incomplete, which may make the computed AP axes shift away from the correct orientation when using the principal component analysis method. A method calculating AP axes based on ellipsoid-fitting is proposed, which can achieve high accuracy when handling incomplete segmented boundaries. Using Worm Developmental Dynamics Database, we evaluated the performance of the proposed segmentation method and the computation of AP axes. Experimental results show that the two methods outperform existing methods.
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[
Mech Ageing Dev,
2001]
Stress experiments performed on a population of sterilised nematode worms (Caenorhabditis elegans) show a clear hormesis effect after short exposure and clear debilitation effects after long exposure to heat shock. An intermediate duration of exposure results in a mixture of these two effects. In this latter case the survival curves for populations in the stress and control groups intersect. In this paper we develop an adaptation model of stress and apply it to the analysis of survival data from three such stress experiments. We show that the model can be used to explain empirical age-patterns of mortality and survival observed in these experiments. We discuss possible biological mechanisms involved in stress response and directions for further research.
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[
Cell,
2014]
Epigenetic inheritance of resistance to exogenous nucleic acids via small interfering (si) RNA is well established in animal models. Rechavi et al. demonstrate epigenetic inheritance of a starvation-induced pattern of gene silencing caused by endogenous siRNAs and resulting in an increased longevity in the third generation progeny. Combined with recent findings in prokaryotes, these results suggest that Lamarckian-type inheritance of acquired traits is a major evolutionary phenomenon.
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[
J Gerontol A Biol Sci Med Sci,
2002]
In this paper we analyze Survival data of populations of sterilized nematodes. Caenorhabditis elegans. exposed to heat shocks of different duration at the beginning of their adult lives. There are clear hormesis effects after short exposure to heat and clear debilitation effects after long exposure. Intermediate durations result in a mixture of these two effects. In this latter case. the survival curves for the control and experimental populations intersect. We show that observed effects may be explained by using a model of discrete heterogeneity. According to this model. each Population of worms in the experiment is a mixture of subcohorts of frail, normal. and robust individuals: exposure to heat changes the initial proportion of worms in the subcohorts (heterogeneity distribution): and these changes depend on the duration Of exposure. In other words, exposure to heat does not influence mortality rates (survival functions) in the subcohorts but does cause individuals to move from one subcohort to another. In a biological interpretation of this finding we hypothesize that. when coping with stress. the organisms of storms use several lines of defense. Switching these lines of ana off in response to stress in individual organisms Generates the spectrum of observed survival effects at the population level. We discuss possible molecular biological mechanisms of stress response and directions for further research.
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J Ethnopharmacol,
2009]
AIM OF STUDY: This study screened for anthelmintic and/or antitumour bioactive compounds from Thai indigenous plants and evaluated effectiveness against three different worm species and two cancer cell lines. MATERIALS AND METHODS: Methylene chloride and methanol extracts of 32 plant species were screened for in vitro anthelmintic activity against three species of worms, the nematode Caenorhabditis elegans, the digeneans Paramphistomum epiclitum and Schistosoma mansoni (cercariae). Cytotoxicity of the extracts was evaluated against two cancer cell lines: human amelanotic melanoma (C32) and human cervical carcinoma (HeLa) by the SRB assay. Anthelmintic and anticancer activities were evaluated by the inhibiting concentration at 50% death (IC(50)) and the selectivity index (SI) relative to human fibroblasts. RESULTS AND CONCLUSIONS: None of the extracts were active against Paramphistomum epiclitum. Plumbagin, a pure compound from Plumbago indica, had the strongest activity against Caenorhabditis elegans. The methylene chloride extract of Piper chaba fruits had the strongest activity against schistosome cercariae. Strong cytotoxicity was shown by the methylene chloride extract of Michelia champaca bark and the methanol extract of Curcuma longa rhizome against C32 and HeLa, respectively. These extracts had higher SI (>100) than positive controls in relation to either the worms or the cell lines. The methanol extract of Bouea burmanica had a slightly lower activity towards C32 cells than did Michelia champaca but had a much higher SI (>27,000). ETHNOPHARMACOLOGICAL RELEVANCE: The plant species screened in this research was recorded by several indigenous medicinal practitioners as antiparasitic, anticancer and/or related activities to the human major organ system.
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Sci Total Environ,
2022]
Environmentally persistent free radicals (EPFRs) have attracted extensive attention due to their potential toxicity. However, EPFRs-containing particles always coexist with their parent organic contaminants and intermediate degradation products (IM), which may have hindered the toxicity assessment of EPFRs. In this study, the toxicity of EFFRs was specifically verified after comparing the systems without EPFRs, such as the immediate mixture of catechol (CT) and particles, solutions of CT only, IM extracted from the particles, as well as particles after EPFRs quenching. Caenorhabditis elegans (C. elegans) were used as model organisms. Our results showed that EPFRs-containing particles (Si-Al-CT) exhibited significant toxicity to C. elegans, but not for the parent chemical CT and IM on the particles. Higher levels of reactive oxygen species (ROS) and malondialdehyde (MDA) in the Si-Al-CT system were attributed to the mediated generation of -O<sub>2</sub><sup>-</sup> and -OH via EPFRs. EPFRs could increase gene expressions related not only to oxidative stress and biotransformation in C. elegans, but also to indications of disturbances in energy homeostasis, survival, proliferation, cell and embryonic development. Overall, these results confirmed the direct toxicity of EPFRs and highlighted the key role of EPFRs which may be neglected in assessing the environmental risks of organic contaminants.
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Int J Biol Macromol,
2015]
Lymphatic filariasis (LF), a morbid vector-borne parasitic infection affects millions in tropical areas. Complete eradication can only be achieved by the development of a potent vaccine. Among the various filarial antigens that have been characterized, antigens Brugia malayi thioredoxin (TRX) and abundant larval transcript (ALT) have produced recognizable level of protection in Jirds, thereby evidenced to be good vaccine candidates. In this study an attempt was made to enhance their immunoprophylactic activity by encapsulating them in natural polysaccharide chitosan forming nanospheres (CN). High encapsulation efficiency for TRX (93%) in CN (TCN) and ALT-2 (90%) in CN (ACN) was achieved. Morphological studies confirmed the spherical and uniform distribution of nanospheres to be 220 nm. The electrostatic interaction between chitosan and the antigens were confirmed using differential scanning calorimetry and FT-IR. The study revealed the immunostimulatory property of chitosan providing enhanced level of proliferation for encapsulated antigens in peripheral blood mononuclear cells from endemic normal personals, at low concentration (TCN mean stimulation index (SI)=4.23+/-0.15 and ACN (SI)=4.05+/-0.33) compared to stimulation obtained by antigens alone. Hence, our study demonstrated that natural macromolecule derived CN can be used as efficacious immunostimulatory vaccine carter for LF thereby diminishing pathological sequel.
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Ferrara, Lorenzo, Callaly, Frank, Morgan, Fearghal, Mc Ginley, Brian, Leskovsky, Peter, Blau, Axel, Machado, Pedro, Krewer, Finn, McGinnity, Martin, Epelde, Gorka, Petrushin, Alexey, Mujika, Andoni
[
International Worm Meeting,
2015]
Despite being one of the five best-characterized model organisms, there is still only sparse knowledge on how C. elegans' nervous system codes for its rich behavioral repertoire. The European Si elegans project aims at unravelling C. elegans' nervous system function (hermaphrodite) by its emulation with 302 parallelly interconnected field-programmable gate array (FPGA) neurons and by embodying this hardware nervous system with a biophysically accurate soft-body representation in a virtual behavioral arena. We critically discuss past and present neurocomputational approaches and pitfalls of simulating nervous system function. We then present the first Si elegans implementation and system integration steps with focus on its key components and challenges. The biophysics-based simulation platform shall allow scientists to test neural processing hypotheses and (un)published behavioral paradigms. Users will have access to all currently known and biologically relevant variables for the reverse-engineering of nervous system function to confirm or even anticipate some of the underlying principles. This contribution aims at opening a scientific discourse on the requirements, possibilities and limits of the faithful biomimetic emulation of an organism from both the biological and engineering perspectives.Acknowledgements: This project has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement ndeg 601215, FET Proactive, call ICT-2011.9.11: Neuro-Bio-Inspired Systems (NBIS). www.si-elegans.eu.