Determination of linezolid in human serum by reversed-phase high-performance liquid chromatography with ultraviolet and diode array detection

A high-performance liquid chromatographic (HPLC) method with UV and DAD detection for the quantitative determination of linezolid in human serum was developed in present work. Chromatography was carried out by reversed-phase technique on a RP-18 column with a mobile phase composed of 50 mM phosphate buffer and acetonitrile (76 : 26, v/v), adjusted to pH 3.5 with orthophosphoric acid. Serum samples were deproteinized with methanol centrifuged and then, the supernatant was analyzed using HPLC procedure. No interference was observed at the retention times of linezolid from blank serum or ten commonly used antibiotics. A concentration range from 0.50 to 30.0 g/mL was utilized to construct calibration curves. The lower limit of detection was determined to be 0.1 μg/mL of serum for both detectors. The lower limit of quantification of 0.25 μg/mL (CV = 2.6%) was established for determination using HPLC-UV and 0.5 μg/mL (CV = 5.42%) for HPLC-DAD. The recovery of linezolid was approximately 100%. Intra-day accuracy ranged from 0.97 to 12.63% and 0.74 to 10.85% for HPLC-UV and HPLC-DAD method, respectively. Intra-day precision was less than 4.69% for HPLC-UV and less than 5.42% for HPLC-DAD method. Tests confirmed the stability of linezolid in serum during three freeze-thaw cycles and during long-term storage of frozen serum for up to 6 weeks; in extracts it was stable in the HPLC autosampler over 24 h. Statistical analysis by Student's t-test showed no significant difference between the results obtained by these two methods. In summary, these methods will be used and adapted for infected patients in intensive care unit, to determine linezolid serum concentrations in order to know the pharmacokinetic profiles of linezolid

Determination of linezolid in human serum by reversed-phase high performance liquid chromatography with ultrafiolet and diode array detection

A high-performance liquid chromatographic (HPLC) method with UV and DAD detection for the quantitative determination of linezolid in human serum was developed in present work. Chromatography was carried out by reversed-phase technique on a RP-18 column with a mobile phase composed of 50 mM phosphate buffer and acetonitrile (76 : 26, v/v), adjusted to pH 3.5 with orthophosphoric acid. Serum samples were deproteinized with methanol centrifuged and then, the supernatant was analyzed using HPLC procedure. No interference was observed at the retention times of linezolid from blank serum or ten commonly used antibiotics. A concentration range from 0.50 to 30.0 g/mL was utilized to construct calibration curves. The lower limit of detection was determined to be 0.1 μg/mL of serum for both detectors. The lower limit of quantification of 0.25 μg/mL (CV = 2.6%) was established for determination using HPLC-UV and 0.5 μg/mL (CV = 5.42%) for HPLC-DAD. The recovery of linezolid was approximately 100%. Intra-day accuracy ranged from 0.97 to 12.63% and 0.74 to 10.85% for HPLC-UV and HPLC-DAD method, respectively. Intra-day precision was less than 4.69% for HPLC-UV and less than 5.42% for HPLC-DAD method. Tests confirmed the stability of linezolid in serum during three freeze-thaw cycles and during long-term storage of frozen serum for up to 6 weeks; in extracts it was stable in the HPLC autosampler over 24 h. Statistical analysis by Student's t-test showed no significant difference between the results obtained by these two methods. In summary, these methods will be used and adapted for infected patients in intensive care unit, to determine linezolid serum concentrations in order to know the pharmacokinetic profiles of linezolid

Virtual reality – future of diagnosis, medical education and therapy

Virtual reality (VR) has found a variety of applications in the biomedical field. It refers to a computer-generated, three-dimensional image of objects, space and even whole events. It is an extremely promising prospect for medicine, both in the training area and as an aid in carrying out certain procedures or diagnostic processes. The number of conducted research and great interest of scientists in this subject indicates that in the future it will be one of the basic tools of medical personnel in diagnostic processes and therapy. It could be also helpful addition to increase education quality of medical students and specialization education. VR increased the safety of surgical training and has significantly improved it, creating completely new possibilities of imaging complex structures during operations and extending the possibilities of already existing imaging examinations. What is important, VR can be successfully adapted for use by specialists from various, often extremely different medical fields. This article describes the use of virtual reality (both VR and AR technologies) in medical training, procedures and diagnostics

Beneficial health effects of treatment with flotation-REST on stress and blood pressure

Flotation-REST is a method where an individual is immersed in a tank filled with water of an extremely high salt concentration, whereby environmental stimulation is restricted. Restricted environmental stimulation technique (REST) is a method used to achieve a deep relaxation and subsequent beneficial health effects on stress and relaxation. The purpose of this paper is to evaluate potential positive health effects of flotation-REST.Flotation-REST treatment decreased the degree of stress. Another study's results indicate that flotation-REST reduces systolic and diastolic blood pressure due to greater relaxation. It was concluded that flotation-REST has beneficial effects on decreasing stress, therefore the method has potential as a complementary treatment of stress-related ailments. However, more studies are warranted to further evaluate the treatments efficacy

Beneficial health effects of treatment with flotation-REST on anxiety, muscle tension pain, depression and sleep quality.

Restricted environmental stimulation therapy (REST) is a method where all the external stimuli are restricted and it is used to relieve stress, anxiety and depression, as well as improving sleep quality. During a session of flotation-REST a patient is lying face-up in a tank filled with high-buoyancy water, allowing the patient to float comfortably on the surface. The tank reduces the external stimulation and allows to achieve a state of deep relaxation. It has many potential health benefits, including reduction of stress, anxiety and depression. A few studies suggested its positive effects on sleep quality too. The purpose of this paper is to evaluate potential positive health effects of flotation-REST.Flotation-REST treatment decreased the degree of stress, anxiety or depression, whereas the patients' optimism and sleep quality were significantly increased. The results also indicate that the most severe perceived pain intensity was significantly reduced, however low perceived pain intensity was not influenced by the floating technique. It was concluded that flotation-REST has beneficial effects on decreasing stress, anxiety, depression and pain, therefore the method has potential as a complementary treatment of these. However, more studies are warranted to further evaluate the treatments efficacy

Logopedist role in childhood cerebral palsy – case report

This is a case study of a 5 years old girl, born as a premature child (27 weeks of pregnancy - extreme prematurity) with a very low birth weight and diagnosed with childhood cerebral palsy and drug-resistant epilepsy. In physical examination was shown: increased thoracic kyphosis, lopsidedness, contracted thoracic muscles, sciatica shin, hip-lumbar muscles, lower limbs in internal rotation. Girl should not be self-service and requires the help of a second person. She is circulatory efficient. She has also limb paresis, sensory disorders, perception, speech development disorders and eye damage.The girl has undergone logopedic therapy. Initially, the adaptation to the new environment and speech therapist was very hard. The observations, help in various situations and various games have made the therapy successful. During the therapy, it was noticed that the girl was sitting incorrectly. The parents also reported problems with acceptance of louder sounds and music (confirmed by the therapist and psychologist), which, however, improves during the therapy. Body motor skills in the described patient is very weak. Since the beginning of the therapy, a full logopedic examination was conducted and specialist tests were performed, which were evaluated on the basis of established scales. The girl is also under physiotherapist's care. The evaluation of the course of therapy shows the progress, and on the basis of the results of examinations and observations, a plan of further therapy has been prepared

Medical 3D printing – the future is here

Introduction: Continuous advances in polymer development and thriving 3D printing methods enable us to reproduce components with exceptional print precision and ensure material biocompatibility under sterile conditions. All this comes down to the fact that the resulting prints better fulfill their roles in the world of medicine and enable patients to recover faster. This precision translates into the main advantage of 3D printing, i.e. personalisation of models with perfectly reproduced structures of a given patient based on CT or MRI tests. At the same time, these prints can be used for didactic purposes by medical students from the very beginning of their professional career, which in the future will make it much easier to perform difficult and complicated operations. Aim of the study: Presentation of the application and positive aspects of 3D printing in medicine. Summary: 3D printing is a permanent feature on the pages of modern medicine. Thanks to it we get to know the personalized morphology of given structures, we more accurately prepare ourselves for the procedure and more often prevent probable complications, and our medical staff receives another dose of knowledge, which they translate into the profession. Conclusions: Training on perfectly reproduced copies printed in 3D can certainly attest to the high qualifications of specialist doctors. The use of widely understood 3D printing technique in medicine is slowly becoming commonplace

Determination of "in vitro" metabolism of a new non-imidazole histamine H3 receptor antagonist 1-[3-(4-tert-butylphenoxy) propyl]piperidine

Early understanding of the pharmacokinetics of drug candidates is essential during the evaluation of drug development process. DL76 1-[3-(4-tert-butylphenoxy)propyl]piperidine is a novel promising non-imidazole H3 receptor antagonist. The presented study was undertaken to compare with each other the predicted hepatic clearance values of DL76 calculated, using two most common mathematical models ìwell-stirredî and ìparallel tubeî, based on the data obtained in in vitro experiments. The metabolic intrinsic clearance of DL76 equaled to 0.4848 mL/min/mg protein was scaled up and the values of hepatic clearance estimated from ìwellstirredî and ìparallel tubeî models were 55.47 mL/min/kg and 58.80 mL/min/kg, respectively. They were further compared with pharmacokinetic parameters calculated based on the concentration-time profile obtained following intravenous administration of DL76 to rats at the dose of 6 mg/kg. The estimated systemic serum clearance value of 144.5 mL/h/kg and blood clearance value of 81.17 mL/min/kg indicate the potential extrahepatic metabolism of the investigated compound. This study demonstrates the utility of rat liver microsomes for the prediction of DL76 hepatic clearance

Reversal of endothelial dysfunction by nicotinamide mononucleotide via extracellular conversion to nicotinamide riboside

Nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR) are effective substrates for NAD synthesis, which may act as vasoprotective agents. Here, we characterize the effects of NMN and NR on endothelial inflammation and dysfunction and test the involvement of CD73 in these effects. Materials and methods: The effect of NMN and NR on IL1β- or TNFα-induced endothelial inflammation (ICAM1 and vWF expression), intracellular NAD concentration and NAD-related enzyme expression (NAMPT, CD38, CD73), were studied in HAECs. The effect of NMN and NR on angiotensin II-induced impairment of endotheliumdependent vasodilation was analyzed in murine aortic rings. The involvement of CD73 in NMN and NR effects was tested using CD73 inhibitor-AOPCP, or CD73$^{-/-}$ mice. Results: 24 h-incubation with NMN and NR induced anti-inflammatory effects in HAEC stimulated by IL1β or TNFα, as evidenced by a reduction in ICAM1 and vWF expression. Effects of exogenous NMN but not NR was abrogated in the presence of AOPCP, that efficiently inhibited extracellular endothelial conversion of NMN to NR, without a significant effect on the metabolism of NMN to NA. Surprisingly, intracellular NAD concentration increased in HAEC stimulated by IL1β or TNFα and this effect was associated with upregulation of NAMPT and CD73, whereas changes in CD38 expression were less pronounced. NMN and NR further increased NAD in IL1β- stimulated HAECs and AOPCP diminished NMN-induced increase in NAD, without an effect on NR-induced response. In ex vivo aortic rings stimulated with angiotensin II for 24 h, NO-dependent vasorelaxation induced by acetylcholine was impaired. NMN and NR, both prevented Ang II-induced endothelial dysfunction in the aorta. In aortic rings taken from CD73$^{-/-}$ mice NMN effect was lost, whereas NR effect was preserved. Conclusion: NMN and NR modulate intracellular NAD content in endothelium, inhibit endothelial inflammation and improve NO-dependent function by CD73-dependent and independent pathways, respectively. Extracellular conversion of NMN to NR by CD73 localized in the luminal surface of endothelial cells represent important vasoprotective mechanisms to maintain intracellular NAD