34 research outputs found

    A study protocol for a feasibility randomised controlled trial investigating videoendoscopic radical inguinal lymphadenectomy versus open radical inguinal lymphadenectomy in patients with penile cancer (VELRAD).

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    BACKGROUND: Penile cancer is a rare male genital malignancy. Surgical excision of the primary tumour is followed by radical inguinal lymphadenectomy if there is metastatic disease detected by biopsy, fine needle aspiration cytology (FNAC) or following sentinel lymph node biopsy in patients with impalpable disease. However, radical inguinal lymphadenectomy is associated with a high morbidity rate, and there is increasing usage of a videoendoscopic approach as an alternative. METHODS: A pragmatic, UK-wide multicentre feasibility randomised controlled trial (RCT), comparing videoendoscopic radical inguinal lymphadenectomy versus open radical inguinal lymphadenectomy. Patients will be identified and recruited from supraregional multi-disciplinary team meetings (sMDT) and must be aged 18 or over requiring inguinal lymphadenectomy, with no contraindications to surgical intervention for their cancer. Participants will be followed up for 6 months following randomisation. The primary outcome is the ability to recruit patients for randomisation across all selected sites and the rate of loss to follow-up. Other outcomes include acceptability of the trial and intervention to patients and healthcare professionals assessed by qualitative research and obtaining resource utilisation information for health economic analysis. DISCUSSION: There are currently no other published RCTs comparing videoendoscopic versus open radical inguinal lymphadenectomy. Ongoing study is required to determine whether randomising patients to either procedure is feasible and acceptable to patients. The results of this study may determine the design of a subsequent trial. TRIAL REGISTRATION: Clinicaltrials.gov PRS registry, registration number NCT05592639. Date of registration: 13th October 2022, retrospectively registered

    Equilibrium solubility versus intrinsic dissolution: characterization of lamivudine, stavudine and zidovudine for BCS classification

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    Solubility and dissolution rate of drugs are of major importance in pre-formulation studies of pharmaceutical dosage forms. The solubility improvement allows the drugs to be potential biowaiver candidates and may be a good way to develop more dose-efficient formulations. Solubility behaviour of lamivudine, stavudine and zidovudine in individual solvents (under pH range of 1.2 to 7.5) was studied by equilibrium solubility and intrinsic dissolution methods. In solubility study by equilibrium method (shake-flask technique), known amounts of drug were added in each media until to reach saturation and the mixture was subjected to agitation of 150 rpm for 72 hours at 37 ÂșC. In intrinsic dissolution test, known amount of each drug was compressed in the matrix of Wood's apparatus and subjected to dissolution in each media with agitation of 50 rpm at 37 ÂșC. In solubility by equilibrium method, lamivudine and zidovudine can be considered as highly soluble drugs. Although stavudine present high solubility in pH 4.5, 6.8, 7.5 and water, the solubility determination in pH 1.2 was not possible due stability problems. Regarding to intrinsic dissolution, lamivudine and stavudine present high speed of dissolution. Considering a boundary value presented by Yu and colleagues (2004), all drugs studied present high solubility characteristics in intrinsic dissolution method. Based on the obtained results, intrinsic dissolution seems to be superior for solubility studies as an alternative method for biopharmaceutical classification purposes

    Volatile Organic Compounds Emitted by Fungal Associates of Conifer Bark Beetles and their Potential in Bark Beetle Control

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    Conifer bark beetles attack and kill mature spruce and pine trees, especially during hot and dry conditions. These beetles are closely associated with ophiostomatoid fungi of the Ascomycetes, including the genera Ophiostoma, Grosmannia, and Endoconidiophora, which enhance beetle success by improving nutrition and modifying their substrate, but also have negative impacts on beetles by attracting predators and parasites. A survey of the literature and our own data revealed that ophiostomatoid fungi emit a variety of volatile organic compounds under laboratory conditions including fusel alcohols, terpenoids, aromatic compounds, and aliphatic alcohols. Many of these compounds already have been shown to elicit behavioral responses from bark beetles, functioning as attractants or repellents, often as synergists to compounds currently used in bark beetle control. Thus, these compounds could serve as valuable new agents for bark beetle management. However, bark beetle associations with fungi are very complex. Beetle behavior varies with the species of fungus, the stage of the beetle life cycle, the host tree quality, and probably with changes in the emission rate of fungal volatiles. Additional research on bark beetles and their symbiotic associates is necessary before the basic significance of ophiostomatoid fungal volatiles can be understood and their applied potential realized

    A common fungal associate of the spruce bark beetle metabolizes the stilbene defenses of Norway spruce

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    Norway spruce (Picea abies) forests suffer periodic fatal attacks by the bark beetle Ips typographus and its fungal associate, Ceratocystis polonica. Norway spruce protects itself against fungal and bark beetle invasion by the production of terpenoid resins, but it is unclear whether resins or other defenses are effective against the fungus. We investigated stilbenes, a group of phenolic compounds found in Norway spruce bark with a diaryl-ethene skeleton with known antifungal properties. During C. polonica infection, stilbene biosynthesis was up-regulated, as evidenced by elevated transcript levels of stilbene synthase genes. However, stilbene concentrations actually declined during infection, and this was due to fungal metabolism. C. polonica converted stilbenes to ring-opened, deglycosylated, and dimeric products. Chromatographic separation of C. polonica protein extracts confirmed that these metabolites arose from specific fungal enzyme activities. Comparison of C. polonica strains showed that rapid conversion of host phenolics is associated with higher virulence. C. polonica is so well adapted to its host’s chemical defenses that it is even able to use host phenolic compounds as its sole carbon source

    Roles of plant volatiles in defence against microbial pathogens and microbial exploitation of volatiles

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    Plants emit a large variety of volatile organic compounds during infection by pathogenic microbes, including terpenes, aromatics, nitrogen‐containing compounds, and fatty acid derivatives, as well as the volatile plant hormones, methyl jasmonate, and methyl salicylate. Given the general antimicrobial activity of plant volatiles and the timing of emission following infection, these compounds have often been assumed to function in defence against pathogens without much solid evidence. In this review, we critically evaluate current knowledge on the toxicity of volatiles to fungi, bacteria, and viruses and their role in plant resistance as well as how they act to induce systemic resistance in uninfected parts of the plant and in neighbouring plants. We also discuss how microbes can detoxify plant volatiles and exploit them as nutrients, attractants for insect vectors, and inducers of volatile emissions, which stimulate immune responses that make plants more susceptible to infection. Although much more is known about plant volatile–herbivore interactions, knowledge of volatile–microbe interactions is growing and it may eventually be possible to harness plant volatiles to reduce disease in agriculture and forestry. Future research in this field can be facilitated by making use of the analytical and molecular tools generated by the prolific research on plant–herbivore interactions.A. H. and T. A. are funded by South African National Research Council Incentive Funds (2019) and the University of Pretoria, and J. G. is funded by the Max Planck Society.https://wileyonlinelibrary.com/journal/pce2020-10-01hj2020BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologyZoology and Entomolog
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