We report on the hyphenation of the modern flow techniques Lab-In-Syringe and Lab-On-Valve for automated sample preparation coupled online with high-performance liquid chromatography. Adopting the bead injection concept on the Lab-On-Valve platform, the on-demand, renewable, solid-phase extraction of five nonsteroidal anti-inflammatory drugs, namely ketoprofen, naproxen, flurbiprofen, diclofenac, and ibuprofen, was carried out as a proof-of-concept. In-syringe mixing of the sample with buffer and standards allowed straightforward pre-load sample modification for the preconcentration of large sample volumes. Packing of ca. 4.4 mg microSPE columns from Oasis HLB® sorbent slurry was performed for each sample analysis using a simple microcolumn adapted to the Lab-On-Valve manifold to achieve low backpressure during loading. Eluted analytes were injected into online coupled HPLC with subsequent separation on a Symmetry C18 column in isocratic mode. The optimized method was highly reproducible, with RSD values of 3.2% to 7.6% on 20 µg L-1 level. Linearity was confirmed up to 200 µg L-1 and LOD values were between 0.06 and 1.98 µg L-1. Recovery factors between 91 and 109% were obtained in the analysis of spiked surface water samples.
V současné době je metoda vnější iontové gelace v přípravě alginátových částic s úspěchem používána nejen na poli farmacie a medicíny, ale zejména v oblasti biotechnologie. Proto byla příprava alginátových částic a jejich následné hodnocení pomocí analýzy hlavních komponent stěžejním cílem našeho experimentu. Kvůli optimalizaci této metody jsme se zaměřili na hodnocení vlivu různých formulačních (koncentrace polymeru, koncentrace tvrdícího roztoku) a procesních parametrů (velikost vnějšího průměru injekční jehly) na vlastnosti vzniklých částic (výtěžek, sféricita, ekvivalentní průměr a bobtnavost při pH 6). Metodou analýzy hlavních komponent byl zásadní vliv na výsledné vlastnosti alginátových částic potvrzen pouze u koncentrace natrium- -alginátu. Tyto výsledky potvrdily spolehlivý a bezpečný potenciál vnější iontové gel
Currently, the method of external ionic gelation for the preparation of alginate particles is successfully used not only in the field of pharmacy and medicine, but also especially in the field of biotechnology. Therefore, the preparation of alginate particles and their subsequent evaluation using principal component analysis was the key task of our experiment. To optimize this method, we focused on the evaluation of the effect of formulation (the polymer concentration, the hardening solution concentration) and process parameters (the outer diameter of the injection needle) on the properties of the resulting beads (yield, sphericity factor, equivalent diameter and swelling capacity at pH 6). Using multivariate data analysis, the major influence on the resulting properties of the prepared particles was confirmed only in sodium alginate concentration. Obtained results verified the reliable and safe potential of the external ionic gelation for preparation alginate-based particulate dosage forms.
The present concept of the transmission of Lyme disease from Borrelia-infected Ixodes sp. ticks to the naïve host assumes that a low number of spirochetes that manage to penetrate the midgut epithelium migrate through the hemocoel to the salivary glands and subsequently infect the host with the aid of immunomodulatory compounds present in tick saliva. Therefore, humoral and/or cellular immune reactions within the tick hemocoel may play an important role in tick competence to act as a vector for borreliosis. To test this hypothesis we have examined complement-like reactions in the hemolymph of the hard tick Ixodes ricinus against Borrelia afzelii (the most common vector and causative agent of Lyme disease in Europe). We demonstrate that I. ricinus hemolymph does not exhibit borreliacidal effects comparable to complement-mediated lysis of bovine sera. However, after injection of B. afzelii into the tick hemocoel, the spirochetes were efficiently phagocytosed by tick hemocytes and this cellular defense was completely eliminated by pre-injection of latex beads. As tick thioester-containing proteins (T-TEPs) are components of the tick complement system, we performed RNAi-mediated silencing of all nine genes encoding individual T-TEPs followed by in vitro phagocytosis assays. Silencing of two molecules related to the C3 complement component (IrC3-2 and IrC3-3) significantly suppressed phagocytosis of B. afzelii, while knockdown of IrTep (insect type TEP) led to its stimulation. However, RNAi-mediated silencing of T-TEPs or elimination of phagocytosis by injection of latex beads in B. afzelii-infected I. ricinus nymphs had no obvious impact on the transmission of spirochetes to naïve mice, as determined by B. afzelii infection of murine tissues following tick infestation. This result supports the concept that Borrelia spirochetes are capable of avoiding complement-related reactions within the hemocoel of ticks competent to transmit Lyme disease.
- MeSH
- Arachnid Vectors immunology microbiology MeSH
- Borrelia burgdorferi Group immunology MeSH
- Phagocytosis * MeSH
- Hemocytes immunology MeSH
- Ixodes immunology microbiology MeSH
- Complement System Proteins metabolism MeSH
- Lyme Disease transmission MeSH
- Disease Models, Animal MeSH
- Mice MeSH
- Disease Transmission, Infectious MeSH
- Arthropod Proteins metabolism MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
... .; Archdeacon and Messerschmitt), 776 -- 21-4 Antibiotic Bead Pouch (Henry, Ostermann, and Seligson), ... ... , 1616 -- 38-2 Cervical Medial Branch Block Injection, 1617 -- 38-3 Cervical Discography (Falco), 1618 ... ... , 1653 -- 39-3 Interlaminar Lumbar Epidural Injection, 1654 -- 39-4 Transforaminal Lumbar and Sacral ... ... Epidural Injection, 1654 -- 39-5 Caudal Sacral Epidural Injection, 1655 -- 39-6 Lumbar Intraarticular ... ... Injection, 1657 -- 39-7 Lumbar Medial Branch Block Injection, 1657 -- 39-8 Sacroiliac Joint Injection ...
Thirteenth edition 4 svazky : ilustrace ; 28 cm
- Conspectus
- Ortopedie. Chirurgie. Oftalmologie
- NML Fields
- ortopedie
- chirurgie
- NML Publication type
- kolektivní monografie
BACKGROUND: The archetypal DNA methyltransferase inhibitors, 5-azacytidine (AZA) and 5-aza-2'-deoxycytidine (DAC) are potent antineoplastic agents used in the treatment of mainly, blood malignancies. However, the administration of these drugs is confounded by their hydrolytic lability which decreases plasma circulation time. Here, we describe a new biodegradable, polyanhydride formulation for drug delivery that circumvents this drawback. METHODS: Injectable/implantable polymeric microbeads containing dispersed microcrystals of hydrophilic AZA or DAC packed in a dry environment are protected from hydrolysis, until the hydrolytic zone reaches the core. Diclofenac is embedded into the formulation to decrease any local inflammation. The efficacy of the formulations was confirmed by monitoring the induced demethylation, and cytostatic/cytotoxic effects of continuous drug release from the time-course dissolution of the microbeads, using an in vitro developed cell based reporter system. RESULTS: Poly(sebaccic acid-co-1,4-cyclohexanedicarboxylic acid) containing 30 wt. % drug showed zero-order release (R(2) = 0.984 for linear regression), and release rate of 10.0 %/h within the first 5 h, and subsequent slower release of the remaining drug, thus maintaining the level of drugs in the outer environment considerably longer than the typical plasma half-life of free azanucleosides. At lower concentrations, the differences between powder drug formulations and microbeads were very low or negligible, however, at higher concentrations, we discovered equivalent or increasing effects of the drugs loaded in microbeads. CONCLUSIONS: The study provides evidence that microbead formulations of the hydrolytically labile azanucleoside drugs could prevent their chemical decomposition in aqueous solution, and effectively increase plasma circulation time.
- MeSH
- Azacitidine administration & dosage analogs & derivatives pharmacology MeSH
- Infusion Pumps, Implantable MeSH
- Cells, Cultured MeSH
- Humans MeSH
- Magnetic Resonance Spectroscopy MeSH
- Microspheres MeSH
- Polymers chemistry MeSH
- Antimetabolites, Antineoplastic administration & dosage pharmacology MeSH
- Absorbable Implants MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
The use of small scale renewable sorbent material for automated solid phase extraction of multi-residue pharmaceuticals in environmental samples exploiting the sequential injection analysis-bead injection with direct coupling to liquid chromatography-electrospray ionization tandem mass spectrometry (SIA-BI-μSPE-LC-ESI-MS/MS) is presented to determine beta-blockers, namely atenolol, sotalol, pindolol, acebutolol, timolol, metoprolol, labetalol, carazolol, propranolol and betaxolol. These compounds yielded the same product ions, therefore were affected in terms of quantification when flow injection analysis-mass spectrometry (FIA-MS) was used. Thus, analytes and matrix present in the sample travel together into the ionization source which can seriously affect the ionization efficiency and analyte signals due to monitoring over a short time period. Graphical abstract A two-dimensional analysis involving a time dimension (retention time) and an m/z dimension (fragmentation ion) is promising for the various sample types. Using the developed method, absolute recoveries percentages of 10 mL of sample loading volume were >91% for all β-blockers with enrichment factor of 62-74, limits of detection of 0.005-0.07 μg L(-1), limits of quantification of 0.01-0.23 μg L(-1), enrichment factor of 62-72 and repeatability within range 7-12%. This developed method is suggested to be used as quantitative screening technique for drugs of abuse or persistent contamination using different kinds of sorbent materials and complex matrix such as biological fluid sample as well.
- MeSH
- Chromatography, Liquid methods MeSH
- Solid Phase Extraction methods MeSH
- Spectrometry, Mass, Electrospray Ionization methods MeSH
- Limit of Detection MeSH
- Reproducibility of Results MeSH
- Tandem Mass Spectrometry methods MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The tachinid fly Exorista larvarum (L.) (Diptera: Tachinidae) is a polyphagous larval endoparasitoid that deposits its eggs on the host exoskeleton of lepidopteran and tenthredinid larvae. The attachment of larval E. larvarum and the formation of the respiratory funnel were studied during infestation in the last larval instar of the wax moth, Galleria mellonella (L.) (Lepidoptera: Pyralidae). The tachinid larvae burrow through the host integument after hatching, using their robust cephalopharyngeal skeleton, leaving a dark spot at the point of their penetration as a result of host cuticle melanization. Endoparasitoid penetration induces the host cellular defence, resulting in the formation of a haemocyte capsule consisting of multi-cellular sheaths. This enveloping capsule later undergoes melanization, which is mostly obvious towards the posterior part of the endoparasitoid. The endoparasitoid uses the host encapsulation response to build a respiratory funnel from the modified host integument, leading to the host surface. The encapsulated larva remains attached to the respiratory funnel via an anal hook and cuticular spines until fully developed. Additional immunohistochemical analyses were used to study host-parasitoid interactions. Indirect immunofluorescence showed no labelling of potential tachinid antigens and confirmed no effect on the surrounding host tissues. A simulated parasitization with coated polybead microspheres revealed the mortal impact of tachinid antigens to the host. Hosts injected with antigen-coated polybeads died as a consequence of an acute and extensive immunological response to the tachinid antigens and not due to the trauma caused by foreign objects inside their body.
- MeSH
- Diptera physiology MeSH
- Fluorescent Antibody Technique, Indirect MeSH
- Host-Parasite Interactions * MeSH
- Larva physiology MeSH
- Microspheres MeSH
- Moths parasitology MeSH
- Mice MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Exenatid QW je depotní forma molekuly exenatidu, která je inkorporována do mikrosfér, z nichž se aktivní látka po subkutánní aplikaci uvolňuje velmi pomalu. Léčivo se aplikuje jedenkrát týdně. Jeho účinky a bezpečnost se zkoumají v sérii klinických studií DURATION-1–6. V nejnovějších studiích je prokazována dlouhodobě dobrá klinická účinnost s nízkým výskytem nežádoucích účinků.
Exenatide QW is a depot form of the molecule exenatide for once weekly administration that is incorporated into the microspheres. The active substance is released from these microspheres very slowly after subcutaneous application. Efficacy and safety of exenatide QW have been evaluated in the series of clinical trials DURATION-1–6. Recent clinical trials show good long-term clinical efficacy with low incidence of adverse effects.
- Keywords
- studie DURATION,
- MeSH
- Diabetes Mellitus, Type 2 * drug therapy MeSH
- Glucagon-Like Peptide 1 * MeSH
- Glycated Hemoglobin drug effects MeSH
- Weight Loss drug effects MeSH
- Injections, Subcutaneous * MeSH
- Humans MeSH
- Microspheres MeSH
- Peptides administration & dosage pharmacology therapeutic use MeSH
- Randomized Controlled Trials as Topic MeSH
- Venoms administration & dosage pharmacology therapeutic use MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
Lactoferrin (LF) is approximately 80 kDa iron-binding protein, which is important part of saliva and other body fluids. Due to its ability to bind metal ions, it has many biologically important functions. In this study, a method for the isolation of LF from a biological sample using robotically prepared antibody-modified paramagnetic particles was developed using robotic pipetting station. The method consisted of the following optimised steps. Protein G was bound on the paramagnetic particles, on which goat antibody (10 μg) was linked. LF was subsequently added to microtitration plate, which had affinity to goat antibody and the interaction lasted for 30 min. We found that the highest signals were obtained using the combination of goat antibody 1:3000, murine antibody 1:5000 and conjugate 1:1500. Horseradish peroxidase reducing 3,3,5,5-tetramethylbenzidine (TMB) was linked to the merged complex. The resulted product of this reaction was subsequently analysed spectrometrically with detection limit (3 S/N) as 5 ng/mL. In addition, we also determined TMB by stopped flow injection analysis with electrochemical detection. The limit of detection (3 S/N) was estimated as 0.1 μg/mL. To compare spectrometric and electrochemical approach for detection of TMB, calibration range of bead-LF-antibodies complex was prepared and was determined using a least-squares correlation with coefficient R² higher than 0.95, indicating a very good agreement of the results obtained.
- MeSH
- Equipment Design MeSH
- Adult MeSH
- Electrochemical Techniques instrumentation MeSH
- Antibodies, Immobilized chemistry MeSH
- Lactoferrin analysis isolation & purification MeSH
- Humans MeSH
- Limit of Detection MeSH
- Magnets chemistry MeSH
- Flow Injection Analysis instrumentation MeSH
- Saliva chemistry MeSH
- Animals MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Evaluation Study MeSH
- Research Support, Non-U.S. Gov't MeSH
