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Praziquantel and Moxidectin pharmacokinetics in dogs after Helmimax administration

The purpose of the research is to study Praziquantel and Moxidectin pharmacokinetics in dogs after Helmimax administration.Materials and methods. Helmimax pharmacokinetics was studied on 8 adult male dogs of different breeds aged 2 to 5 years and weighing 15–35 kg. Helmimax was administered orally in the fasted state with a small amount of feed at a dose of 5 mg/kg for Praziquantel and 0.25 mg/kg for Moxidectin at the rate of 1 tablet per 10 kg of body weight. Blood was sampled at various periods after the administration. The collected blood underwent sample processing: formed element and protein precipitation, solid-phase extraction, and microfiltration. The active components were analyzed and detected by the HPLC-MS/MS. Active substances in the blood plasma were determined according to the developed technique which had been validated. The device was calibrated before the measurement.Results and discussion. As a result of the studies, the Praziquantel and Moxidectin pharmacokinetic parameters were calculated. The maximum concentration was 0.240 and 0.130 μg/mL, the time-to-peak concentration was 2.15 and 1.48 hours, and the elimination half-life was 8.41 and 3.61 hours for Moxidectin and Praziquantel, respectively

Ablation of the Pro-Apoptotic Protein Bax Protects Mice from Glucocorticoid-Induced Bone Growth Impairment

Dexamethasone (Dexa) is a widely used glucocorticoid to treat inflammatory diseases; however, a multitude of undesired effects have been reported to arise from this treatment including osteoporosis, obesity, and in children decreased longitudinal bone growth. We and others have previously shown that glucocorticoids induce apoptosis in growth plate chondrocytes. Here, we hypothesized that Bax, a pro-apoptotic member of the Bcl-2 family, plays a key role in Dexa-induced chondrocyte apoptosis and bone growth impairment. Indeed, experiments in the human HCS-2/8 chondrocytic cell line demonstrated that silencing of Bax expression using small-interfering (si) RNA efficiently blocked Dexa-induced apoptosis. Furthermore, ablation of Bax in female mice protected against Dexa-induced bone growth impairment. Finally, Bax activation by Dexa was confirmed in human growth plate cartilage specimens cultured ex vivo. Our findings could therefore open the door for new therapeutic approaches to prevent glucocorticoid-induced bone growth impairment through specific targeting of Bax

Фармакокинетика празиквантела и моксидектина в организме собак после применения гельмимакса

The purpose of the research is to study Praziquantel and Moxidectin pharmacokinetics in dogs after Helmimax administration.Materials and methods. Helmimax pharmacokinetics was studied on 8 adult male dogs of different breeds aged 2 to 5 years and weighing 15–35 kg. Helmimax was administered orally in the fasted state with a small amount of feed at a dose of 5 mg/kg for Praziquantel and 0.25 mg/kg for Moxidectin at the rate of 1 tablet per 10 kg of body weight. Blood was sampled at various periods after the administration. The collected blood underwent sample processing: formed element and protein precipitation, solid-phase extraction, and microfiltration. The active components were analyzed and detected by the HPLC-MS/MS. Active substances in the blood plasma were determined according to the developed technique which had been validated. The device was calibrated before the measurement.Results and discussion. As a result of the studies, the Praziquantel and Moxidectin pharmacokinetic parameters were calculated. The maximum concentration was 0.240 and 0.130 μg/mL, the time-to-peak concentration was 2.15 and 1.48 hours, and the elimination half-life was 8.41 and 3.61 hours for Moxidectin and Praziquantel, respectively.Цель исследований – изучение фармакокинетики празиквантела и моксидектина в организме собак после применения гельмимакса.Материалы и методы. Исследования фармакокинетики гельмимакса проводили на 8 взрослых собаках самцах массой тела 15–35 кг разных пород в возрасте от 2 до 5 лет. Гельмимакс вводили перорально натощак с небольшим количеством корма в дозе 5 мг/кг по празиквантелу и 0,25 мг/кг по моксидектину из расчета 1 таблетка на 10 кг массы тела. Отбор крови проводили через различные временные интервалы после введения. Отобранную кровь подвергали пробоподготовке: осаждение форменных элементов, белков, твердофазная экстракция, микрофильтрация. Анализ и детектирование действующих компонентов проводили методом ВЭЖХ МС/МС. Определение действующих веществ в плазме крови проводили по разработанной методике, которая прошла валидацию. Перед измерением осуществляли калибровку прибора.Результаты и обсуждение. В результате проведенных исследований были рассчитаны фармакокинетические показатели празиквантела и моксидектина. Максимальная концентрация составила 0,240 и 0,130 мкг/мл, время достижения максимальной концентрации 2,15 и 1,48 ч, период полувыведения 8,41 и 3,61 ч для моксидектина и празиквантела соответственно

Identification of DHX9 as a cell cycle regulated nucleolar recruitment factor for CIZ1

CIP1-interacting zinc finger protein 1 (CIZ1) is a nuclear matrix associated protein that facilitates a number of nuclear functions including initiation of DNA replication, epigenetic maintenance and associates with the inactive X-chromosome. Here, to gain more insight into the protein networks that underpin this diverse functionality, molecular panning and mass spectrometry are used to identify protein interaction partners of CIZ1, and CIZ1 replication domain (CIZ1-RD). STRING analysis of CIZ1 interaction partners identified 2 functional clusters: ribosomal subunits and nucleolar proteins including the DEAD box helicases, DHX9, DDX5 and DDX17. DHX9 shares common functions with CIZ1, including interaction with XIST long-non-coding RNA, epigenetic maintenance and regulation of DNA replication. Functional characterisation of the CIZ1-DHX9 complex showed that CIZ1-DHX9 interact in vitro and dynamically colocalise within the nucleolus from early to mid S-phase. CIZ1-DHX9 nucleolar colocalisation is dependent upon RNA polymerase I activity and is abolished by depletion of DHX9. In addition, depletion of DHX9 reduced cell cycle progression from G1 to S-phase in mouse fibroblasts. The data suggest that DHX9-CIZ1 are required for efficient cell cycle progression at the G1/S transition and that nucleolar recruitment is integral to their mechanism of action

Estrogen/Estrogen Receptor Alpha Signaling in Mouse Posterofrontal Cranial Suture Fusion

BACKGROUND: While premature suture fusion, or craniosynostosis, is a relatively common condition, the cause is often unknown. Estrogens are associated with growth plate fusion of endochondral bones. In the following study, we explore the previously unknown significance of estrogen/estrogen receptor signaling in cranial suture biology. METHODOLOGY/PRINCIPAL FINDINGS: Firstly, estrogen receptor (ER) expression was examined in physiologically fusing (posterofrontal) and patent (sagittal) mouse cranial sutures by quantitative RT-PCR. Next, the cranial suture phenotype of ER alpha and ER beta knockout (alphaERKO, betaERKO) mice was studied. Subsequently, mouse suture-derived mesenchymal cells (SMCs) were isolated; the effects of 17-beta estradiol or the estrogen antagonist Fulvestrant on gene expression, osteogenic and chondrogenic differentiation were examined in vitro. Finally, in vivo experiments were performed in which Fulvestrant was administered subcutaneously to the mouse calvaria. Results showed that increased ERalpha but not ERbeta transcript abundance temporally coincided with posterofrontal suture fusion. The alphaERKO but not betaERKO mouse exhibited delayed posterofrontal suture fusion. In vitro, addition of 17-beta estradiol enhanced both osteogenic and chondrogenic differentiation in suture-derived mesenchymal cells, effects reversible by Fulvestrant. Finally, in vivo application of Fulvestrant significantly diminished calvarial osteogenesis, inhibiting suture fusion. CONCLUSIONS/SIGNIFICANCE: Estrogen signaling through ERalpha but not ERbeta is associated with and necessary for normal mouse posterofrontal suture fusion. In vitro studies suggest that estrogens may play a role in osteoblast and/or chondrocyte differentiation within the cranial suture complex

Oriented clonal cell dynamics enables accurate growth and shaping of vertebrate cartilage.

Cartilaginous structures are at the core of embryo growth and shaping before the bone forms. Here we report a novel principle of vertebrate cartilage growth that is based on introducing transversally-oriented clones into pre-existing cartilage. This mechanism of growth uncouples the lateral expansion of curved cartilaginous sheets from the control of cartilage thickness, a process which might be the evolutionary mechanism underlying adaptations of facial shape. In rod-shaped cartilage structures (Meckel, ribs and skeletal elements in developing limbs), the transverse integration of clonal columns determines the well-defined diameter and resulting rod-like morphology. We were able to alter cartilage shape by experimentally manipulating clonal geometries. Using in silico modeling, we discovered that anisotropic proliferation might explain cartilage bending and groove formation at the macro-scale

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field