Phytiatrie et fonction du phytiatre en phytoprotection

La phytiatrie est une branche de la phytoprotection dont la définition est peu claire, variable et très confuse dans la littérature. Dans cet article dont les données sont issues de sources secondaires, nous essayons de : (1) clarifier la définition des mots phytiatrie et phytiatre ; (2) préciser le contenu d’une formation de base en phytiatrie ; (3) proposer une organisation de la fonction de phytiatre. Le phytiatre (médecin de la plante), s’occupe de la gestion des maladies, des agresseurs et des traumatismes des plantes. La phytiatrie se distingue clairement de la phytopathologie, science qui étudie les maladies des plantes causées par les microorganismes et les facteurs environnementaux. Le phytiatre a des connaissances en phytopharmacie, mais n’est pas un phytopharmacien. Le diplômé en phytiatrie doit être capable d’analyser et de comprendre les exigences de la phytoprotection afin de développer et de proposer des solutions adéquates, dans un contexte de protection de l’environnement. Le grade de phytiatre devrait être réservé aux ingénieurs en phytiatrie, aux titulaires d’un Master ou d'un Doctorat / Ph.D en phytiatrie. Une meilleure structuration des formations en phytiatrie et de la fonction de phytiatre, peut contribuer à une meilleure prise en charge des affections des plantes dans les systèmes de production en Afrique. English title: Phytiatrics and function of the phytiatrist in plant protection Abstract Phytiatrics is a branch of Phytoprotection whose definition is unclear, variable and very confused in the literature. In this article, whose data come from secondary sources, we try to: (1) clarify the definition of phytiatrics and phytiatrist; (2) specify the content of basic training in phytiatrics; (3) propose an organization of the function of phytiatrist. The phytiatrist (plant medical doctor) deals with the management of plant diseases, pests and trauma. Phytiatrics is clearly distinguished from phytopathology which is the science that studies plant diseases caused by microorganisms and environmental factors. The phytiatrist has knowledge in phytopharmacy, but is not a phytopharmacist. The graduate in phytiatrics must be able to analyze and understand the requirements of phytoprotection in order to develop and propose adequate solutions, in a context of environmental protection. The rank of phytiatrist should be reserved for engineers in phytiatrics, holders of a Master’s degree or a doctorate in phytiatrics. A better structuring of training in phytiatrics and the function of phytiatrist can contribute to better management of plant ailments in plant production systems in Africa. Keywords: plant, disease, aggressors, training, phytiatrist

Phytochemistry and pharmacology of the genus Drypetes: A review

Aims: Traditional medicinal use of species of the genus Drypetes is widespread in the tropical regions. The aim of this review is to systematically appraise the literature available to date on phytochemistry, ethnopharmacology, toxicology and bioactivity (in vitro and in vivo) of crude extracts and purified compounds. Ethnopharmacological relevance: Plants of the genus Drypetes (Putranjivaceae) are used in the Subsaharan African and Asian traditional medicines to treat a multitude of disorders, like dysentery, gonorrhoea, malaria, rheumatism, sinusitis, tumours, as well as for the treatment of wounds, headache, urethral problems, fever in young children, typhoid and several other ailments. Some Drypetes species are used to protect food against pests, as an aphrodisiac, a stimulant/depressant, a rodenticide and a fish poison, against insect bites, to induce conception and for general healing. This review deals with updated information on the ethnobotany, phytochemistry, and biological activities of ethnomedicinally important Drypetes species, in order to provide an input for the future research opportunities. Methods: An extensive review of the literature available in various recognized databases e.g., Google Scholar, PubMed, Science Direct, SciFinder, Web of Science, www.theplantlist.org and www.gbif.org, as well as the Herbier National du Cameroun (Yaoundé) and Botanic Gardens of Limbe databases on the uses and bioactivity of various species of the Drypetes was undertaken. Results: The literature provided information on ethnopharmacological uses of the Subsaharan African and Asian species of the genus Drypetes, e.g., Drypetes aubrévillii, D. capillipes, D. chevalieri, D. gerrardii, D. gossweileri, D. ivorensis, D. klainei, D. natalensis, D. pellegrini (all endemic to Africa) and D. roxburghii (Asian species), for the treatment of multiple disorders. From a total of 19 species, more than 140 compounds including diterpenes, sesquiterpenes, triterpenes (friedelane, oleanane, lupane and hopane-type), flavonoids, lignans, phenylpropanoids and steroids, as well as some thiocyanates, were isolated. Several crude extracts of these plants, and isolated compounds displayed significant analgesic, anthelmintic, antidiabetic, anti-emetic anti-inflammatory, antioxidant, antiparasitic, central nervous system depressant, cytotoxic, and insecticidal activities both in vitro and in vivo. Some toxicities associated with the stem, bark, seed and leaf extracts of D. roxburghii, and the flavonoid, amentoflavone, isolated from the stem extract of D. littoralis as well as D. gerrardii, were confirmed in the animal models and in the rat skeletal myoblast cells assays. As a consequence, traditional medicine from this genus should in future be applied with care. Conclusions: Plants of this genus have offered bioactive samples, both from crude extracts and pure compounds, partly validating their effectivity in traditional medicine. However, most of the available scientific litteratures lacks information on relevant doses, duration of the treatment, storage conditions and positive controls for examining bioefficacy of extract and its active compounds. Additional toxicological studies on the species used in local pharmacopeia are urgently needed to guarantee safe application due to higth toxicity of some crude extracts. Interestingly, this review also reports 10 pimarane dinorditerpenoids structures with the aromatic ring C, isolated from the species collected in Asia Drypetes littoralis (Taiwan), D. perreticulata (China), and in Africa D. gerrardii (Kenya), D. gossweileri (Cameroon). These compounds might turn out to be good candidates for chemotaxonomic markers of the genus

Anticancer and antibacterial secondary metabolites from the endophytic fungus Penicillium sp. CAM64 against multi-drug resistant Gram-negative bacteria.

Background: The emergence of multiple-drug resistance bacteria has become a major threat and thus calls for an urgent need to search for new effective and safe anti-bacterial agents. Objectives: This study aims to evaluate the anticancer and antibacterial activities of secondary metabolites from Penicillium sp. , an endophytic fungus associated with leaves of Garcinia nobilis . Methods: The culture filtrate from the fermentation of Penicillium sp. was extracted and analyzed by liquid chromatography\u2013 mass spectrometry, and the major metabolites were isolated and identified by spectroscopic analyses and by comparison with published data. The antibacterial activity of the compounds was assessed by broth microdilution method while the anticancer activity was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Results: The fractionation of the crude extract afforded penialidin A-C (1-3), citromycetin (4), p-hydroxyphenylglyoxalaldoxime (5) and brefelfin A (6). All of the compounds tested here showed antibacterial activity (MIC = 0.50 \u2013 128 \u3bcg/mL) against Gramnegative multi-drug resistance bacteria, Vibrio cholerae (causative agent of dreadful disease cholera) and Shigella flexneri (causative agent of shigellosis), as well as the significant anticancer activity (LC50 = 0.88 \u2013 9.21 \u3bcg/mL) against HeLa cells. Conclusion: The results obtained indicate that compounds 1-6 showed good antibacterial and anticancer activities with no toxicity to human red blood cells and normal Vero cells

Proliferating Cell Nuclear Antigen (PCNA) Regulates Primordial Follicle Assembly by Promoting Apoptosis of Oocytes in Fetal and Neonatal Mouse Ovaries

Primordial follicles, providing all the oocytes available to a female throughout her reproductive life, assemble in perinatal ovaries with individual oocytes surrounded by granulosa cells. In mammals including the mouse, most oocytes die by apoptosis during primordial follicle assembly, but factors that regulate oocyte death remain largely unknown. Proliferating cell nuclear antigen (PCNA), a key regulator in many essential cellular processes, was shown to be differentially expressed during these processes in mouse ovaries using 2D-PAGE and MALDI-TOF/TOF methodology. A V-shaped expression pattern of PCNA in both oocytes and somatic cells was observed during the development of fetal and neonatal mouse ovaries, decreasing from 13.5 to 18.5 dpc and increasing from 18.5 dpc to 5 dpp. This was closely correlated with the meiotic prophase I progression from pre-leptotene to pachytene and from pachytene to diplotene when primordial follicles started to assemble. Inhibition of the increase of PCNA expression by RNA interference in cultured 18.5 dpc mouse ovaries strikingly reduced the apoptosis of oocytes, accompanied by down-regulation of known pro-apoptotic genes, e.g. Bax, caspase-3, and TNFα and TNFR2, and up-regulation of Bcl-2, a known anti-apoptotic gene. Moreover, reduced expression of PCNA was observed to significantly increase primordial follicle assembly, but these primordial follicles contained fewer guanulosa cells. Similar results were obtained after down-regulation by RNA interference of Ing1b, a PCNA-binding protein in the UV-induced apoptosis regulation. Thus, our results demonstrate that PCNA regulates primordial follicle assembly by promoting apoptosis of oocytes in fetal and neonatal mouse ovaries

Morphometric and gene expression analyses of stromal expansion during development of the bovine fetal ovary

During ovarian development stroma from the mesonephros penetrates and expands into the ovarian primordium and thus appears to be involved, at least physically, in the formation of ovigerous cords, follicles and surface epithelium. Cortical stromal development during gestation in bovine fetal ovaries (n = 27) was characterised by immunohistochemistry and by mRNA analyses. Stroma was identified by immunostaining of stromal matrix collagen type I and proliferating cells were identified by Ki67 expression. The cortical and medullar volume expanded across gestation, with the rate of cortical expansion slowing over time. During gestation, the proportion of stroma in the cortex and total volume in the cortex significantly increased (P  0.05). The expression levels of 12 genes out of 18 examined, including osteoglycin (OGN) and lumican (LUM), were significantly increased later in development (P < 0.05) and the expression of many genes was positively correlated with other genes and with gestational age. Thus, the rate of cortical stromal expansion peaked in early gestation due to cell proliferation, whilst late in development expression of extracellular matrix genes increased.M.D. Hartanti, A K. Hummitzsch, H.F. Irving-Rodgers, W.M. Bonner, K.J. Copping, R.A. Anderson, I.C. McMillen, V.E.A. Perry and R.J. Rodger

Current achievements and future research directions in ovarian tissue culture, in vitro follicle development and transplantation: implications for fertility preservation

Female cancer patients are offered 'banking' of gametes before starting fertility-threatening cancer therapy. Transplants of fresh and frozen ovarian tissue between healthy fertile and infertile women have demonstrated the utility of the tissue banked for restoration of endocrine and fertility function. Additional methods, like follicle culture and isolated follicle transplantation, are in development. Specialist reproductive medicine scientists and clinicians with complementary expertise in ovarian tissue culture and transplantation presented relevant published literature in their field of expertise and also unpublished promising data for discussion. As the major aims were to identify the current gaps prohibiting advancement, to share technical experience and to orient new research, contributors were allowed to provide their opinioned expert views on future research. Normal healthy children have been born in cancer survivors after orthotopic transplantation of their cryopreserved ovarian tissue. Longevity of the graft might be optimized by using new vitrification techniques and by promoting rapid revascularization of the graft. For the in vitro culture of follicles, a successive battery of culture methods including the use of defined media, growth factors and three-dimensional extracellular matrix support might overcome growth arrest of the follicles. Molecular methods and immunoassay can evaluate stage of maturation and guide adequate differentiation. Large animals, including non-human primates, are essential working models. Experiments on ovarian tissue from non-human primate models and from consenting fertile and infertile patients benefit from a multidisciplinary approach. The new discipline of oncofertility requires professionalization, multidisciplinarity and mobilization of funding for basic and translational research

Assessing long-term management options for the villages in the Korup National Park: an evaluation of all options

This study assesses the social, economical, ecological, political, legal, and institutional implications of options related to ‘resettlement’, ‘boundary change’, and ‘enclave’ delineation for each of the five park villages.The study finds that attempting to resettle all the villages from the Korup National Park (KNP) may not be realistic or achievable. At the same time, the present status quo proves not being tenable. Bareka-Batanga is the village the most clearly prepared to resettle, and the least costly too. If the Bakoko group of villages cannot be resettled, it will need a comprehensive development conservation plan within a ‘sustainable livelihood option’ here named ‘enclave option. Three options exist for Erat and its twin village Ekon I: resettlement, with the financial cost scenarios particularly high; maintaining them where they are presently, that implies the much lower short-term financial cost; changing of the park’s boundary.The economic analysis finds that under the original assumptions of the Korup project, resettling the villages remains a preferred option for long-term economic benefits. But slight changes into these assumptions significantly reduce forecasted benefits. By contrast, in the short term, the financial costs of resettlement are much higher than other options. The ecological assessment finds that people in the KNP are traditional forest-farmers, with almost 1/12th of the park already domesticated. At the same time, these communities depend vitally on the whole range of environmental services provided by the primary forest. In contrast, the study does not find evidence that hunting, fishing, or gathering by park villagers constitutes, as such, a threat to the sustainability of the wildlife or the ecosystems. The sociological analysis finds that communities’ perceptions of the KNP are dominated by the sentiment that they have been deceived and abandoned. Parts of these communities would still like to be resettled, other want to stop all talks of resettlement and just ‘divide’ up the forest between them and the Korup project. Legal alternatives to the resettlement such as degazettment of part of the KNP to allow for certain villages to stay where they are while exercising freely their activities; the adaptation of the management plan, with the justification that such enclaves fall within the fundamental objectives of the management of the park; and a special regulatory amendment, by Decree of the Prime Minister or by ordinance of the President of the Republic with regulatory power

Performance optimized expectation conditional maximization algorithms for nonhomogeneous poisson process software reliability models

Nonhomogeneous Poisson process (NHPP) and software reliability growth models (SRGM) are a popular approach to estimate useful metrics such as the number of faults remaining, failure rate, and reliability, which is defined as the probability of failure free operation in a specified environment for a specified period of time. We propose performance-optimized expectation conditional maximization (ECM) algorithms for NHPP SRGM. In contrast to the expectation maximization (EM) algorithm, the ECM algorithm reduces the maximum-likelihood estimation process to multiple simpler conditional maximization (CM)-steps. The advantage of these CM-steps is that they only need to consider one variable at a time, enabling implicit solutions to update rules when a closed form equation is not available for a model parameter. We compare the performance of our ECM algorithms to previous EM and ECM algorithms on many datasets from the research literature. Our results indicate that our ECM algorithms achieve two orders of magnitude speed up over the EM and ECM algorithms of [1] when their experimental methodology is considered and three orders of magnitude when knowle dge of the maximum-likelihood estimation is removed, whereas our approach is as much as 60 times faster than the EM algorithms of [2] . We subsequently propose a two-stage algorithm to further accelerate performance