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  • Owens Forsyth posted an update 1 week ago

    In this article the reasons why it is important that care is taken in designating chemicals as respiratory allergens are reviewed. The value and limitations of human data that can aid the accurate identification of chemical respiratory allergens are explored, including exposure conditions, response characteristics in specific inhalation challenge tests, and immunological investigations.This paper compares the phase-specific inhalation toxicity of the cyclic semi-volatile methylsiloxanes (cVMSs) D4, D5 and D6. The objectives of this paper are to re-analyze information from acute to chronic inhalation studies on rats with these cVMSs to identify the unifying principles of phase-specific toxicity at the portal-of-entry and if they depend on acute, acute-on-chronic or chronic mechanisms. This re-analysis supports the hypothesis that concentrations must be high enough to exceed the vapor saturation at any given temperature for stabilizing the aerosol phase and evoking phase-specific effects at sites of the respiratory tract susceptible to the cVMSs-specific physicochemical properties amphiphilicity and surface tension. In summary, the portal-of-entry effects and related findings appear to be acute in nature and specific to liquid aerosol. The repeated inhalation exposure studies with D4 and D5 up to two years in duration did not reveal chronic aggravations of portal of entry outcomes. Findings at a pulmonary location where amphiphilic surfactant molecules are present appear to be caused by the acute adaptation to deposited dose. Such outcome should better be described as a high-dose liquid aerosol phenomenon imparted by the physicochemical properties “liquid” and “hydrophobic”. This calls for a phase-specific human risk characterization of cVMSs.The aim of this paper was to provide a comprehensive toxicological and safety evaluation of a yeast cell wall preparation (YCWP) for use as an animal feed ingredient. The following toxicological assessments were carried out the mutagenic activity was tested using the Ames’ Test in five Salmonella typhimurium strains; clastogenic activity was investigated using the mammalian micronucleus test in Swiss ICO OF1 (IOPS Caw) mice; genotoxic activity was assessed using the in vitro mammalian chromosomal aberration test in human lymphocytes; acute oral toxicity was tested by administration of a single dose of 2000 mg/kg BW. Eye and skin irritation were assessed in rabbits according to OECD guidelines; skin sensitivity was established in guinea pigs by means of the Buehler test, while acute dermal and inhalation studies in rats were further completed, also according to OECD guidelines. All conducted tests were considered valid under the experimental conditions. No significant mutagenic activity or genotoxic activity was observed, and it was concluded that the test article did not induce any clastogenic effect. YCWP was found to be mildly irritating to the eye, slightly irritating to the skin but was found to be non-sensitizing in the guinea pig. The acute oral, dermal and inhalation studies did not yield any evidence of gross toxicity or pharmacological effects.

    Accelerated partial breast irradiation (APBI) represents a validated technique for low-risk breast cancer. Recently, ultra-APBI (uAPBI) using fewer than 5 fractions was described in the literature. We compared clinical outcomes and late toxicity after APBI or uAPBI in older patients.

    Two cohorts of older patients (aged ≥70 years) with low-risk breast cancer treated with APBI (interstitial brachytherapy) were analyzed retrospectively. A total dose of 34 Gy in10 fractions (APBI) or 16 Gy in 1 fraction (uAPBI) was delivered from 2004 to 2012 and from 2013 to 2018, respectively. Oncologic outcome analyzed the cumulative incidence of local relapse, regional relapse, and distant metastases with disease-free survival, cause-specific survival, and overall survival. Late toxicity and cosmetic results were investigated.

    One hundred fifty-seven patients (APBI, n=109 patients; uAPBI, n=48 patients) underwent APBI according to the same selection criteria. read more Apart from the median follow-up (97 vs 72 months for APBI andsult. uAPBI based on a single fraction of brachytherapy represents an attractive option for therapeutic de-escalation in older patients with breast cancer.

    We report the first study comparing APBI versus uAPBI in a cohort of older patients with low-risk breast cancer. No significant difference was found between the 2 treatment groups regarding oncologic outcome, late toxicity, and cosmetic result. uAPBI based on a single fraction of brachytherapy represents an attractive option for therapeutic de-escalation in older patients with breast cancer.Needle-free jet injections are actuated by a pressure impulse that can be delivered by different mechanisms to generate high-speed jets (Vj~O102 m/s). During filling and transportation of disposable cartridges and ampoules, bubbles can form, which can be problematic especially for viscous fluids. Here, we report on the effect of location and size of entrapped air pockets in cartridges used in spring-powered jet injections. As air bubbles pass through the orifice, they undergo depressurization, which results in intermittent atomization and spray formation, temporarily increasing the jet dispersion. Atomization and dispersion of the jet can lead to product loss during an injection. We find that the effect of bubble location on the jet exit speed, delivery efficiency, and the projected area of the blebs formed after the injection was statistically significant (p less then 0.05). The findings of this study have implications for the development of pre-filled cartridges for jet injection applications.As part of early drug development, preformulation studies are used to comprehensively explore the properties of new drugs. In particular, this includes the biopharmaceutical characterization and evaluation of impacting factors (e.g. excipients, microenvironmental conditions etc.) by permeation studies. To overcome the limitations of current studies, a novel standardized ex vivo procedure using esophageal mucosa as surrogate has been established successfully and applied to preformulation studies for oromucosal delivery of cyclobenzaprine hydrochloride, a tricyclic muscle relaxant with potential for psychopharmacotherapeutic use. By using the standardized ex vivo permeation process, a twofold enhancement of permeability (0.98 ± 0.16 to 1.96 ± 0.10 * 10-5 cm/s) was observed by adjustment and controlling of microenvironmental pH, empowering a targeted and effective development of sublingual formulations. Predictivity and suitability were superior compared to in vitro experiments using artificial biomimetic membranes, revealing a determination coefficient (R2) of 0.

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