- Dettagli della rivista
- Pubblicato per la prima volta
- 25 Nov 2011
- Periodo di pubblicazione
- 2 volte all'anno
- Accesso libero
An adjustment of vancomycin dosing regimen for a young patient with augmented renal clearance: A case report / Úprava dávkového režimu vankomycínu pre mladého pacienta so zvýšeným renálnym klírensom: Kazuistika
Pagine: 1 - 4
Augmented renal clearance (ARC) is a recently reported condition in pathophysiology of critically ill patients in the intensive care unit. ARC refers to the enhanced renal elimination of circulating solutes. These patients are either young or previously healthy people who have undergone surgery or multiple trauma.
This case report describes an adjustment of dosing regime of vancomycin to a young patient, who demonstrated ARC with severe polytrauma, overcome crush syndrome and sepsis. This 16-year old male patient was crushed by a tractor, which caused severe tissue damaged in the right lower limb. He gradually developed a serious crush syndrome. When kidneys resumed their function, creatinine clearance reached the value that indicated ARC (339.81 mL/min/1.73 m2). Vancomycin was included in the patient’s treatment regime by administering conventional dose of 1 g per 12 hours. The residual measured levels were very low. The dose of vancomycin had to be adjusted to double and then to triple the conventional dose. Without the therapeutic drug monitoring (TDM) and subsequent interpretation of the results by the clinical pharmacists, such high doses would not have been considered for administration.
ARC responds strongly to sub-therapeutic serum vancomycin levels. Our case report confirms the significance of TDM and the consecutive interpretation of the results in critically ill patients.
- Augmented renal clearance (ARC)
- Therapeutic drug monitoring (TDM)
- Accesso libero
Kinetic Modelling of Drug Release from Pentoxifylline Matrix Tablets based on Hydrophilic, Lipophilic and Inert Polymers
Pagine: 5 - 12
Pentoxifylline is a xanthine derivative used in the treatment of peripheral vascular disease, which because of its pharmacokinetic and pharmacologic profile is an ideal candidate for the development of extended release formulations. The aim of this study is to present a kinetic analysis of the pentoxifylline release from different extended release tablets formulations, using mechanistic and empirical kinetic models. A number of 28 formulations were prepared and analysed; the analysed formulations differed in the nature of the matrix forming polymers (hydrophilic, lipophilic, inert) and in their concentrations. Measurements were conducted in comparison with the reference product Trental 400 mg (Aventis Pharma). The conditions for the dissolution study were according to official regulations of USP 36: apparatus no. 2, dissolution medium water, volume of dissolution medium is 1,000 mL, rotation speed is 50 rpm, spectrophotometric assay at 274 nm. Six mathematical models, five mechanistic (0 orders, 1st-order release, Higuchi, Hopfenberg, Hixson-Crowell) and one empirical (Peppas), were fitted to pentoxifylline dissolution profile from each pharmaceutical formulation. The representative model describing the kinetics of pentoxifylline release was the 1st-order release, and its characteristic parameters were calculated and analysed.
- modified release tablets
- kinetic modelling
- Accesso libero
Spirulina maxima and its effect on antioxidant activity in fructose induced oxidative stress with histopathological observations
Pagine: 13 - 19
Diabetes mellitus is a metabolic disorder characterised by hyperglycemia and oxidative stress. The aim of the present study is to explore the antioxidant effect of Spirulina maxima in rat model along with the histopathological observations. Diabetes was induced by feeding 10% fructose solution orally to Wistar rats (n = 6) for 30 days, analysed for plasma blood glucose and the markers of the oxidative stress [catalase (CAT), superoxide dismutase (SOD), reduced glutathione (GSH) and thiobarbituric acid reactive substances (TBARS)]. These biochemical studies were associated with histopathological examination of liver and kidney sections. The microalga Spirulina maxima being rich in proteins and other essential nutrients is widely used as a food supplement. S. maxima at a dose of 5 and 10% per kg and the metformin (500 mg/kg) as reference drug were given orally for 30 days to the diabetic rats. Diabetic rats showed significant (p < 0.001) elevations in plasma blood glucose, thiobarbituric acid-reactive substances and significant reduction in catalase, superoxide dismutase and reduced glutathione activity. Oral administration of 5 and 10% aqueous extract of S. maxima for 30 days restored not only of blood glucose levels but also markers of oxidative stress. Histopathological observations of tissues manifested that the S. maxima administration had the protective and therapeutic effects against fructose-induced abnormalities in diabetic rats. It is concluded that S. maxima is effective in reinstating the antioxidant activity in addition to its antidiabetic effect in type 2 diabetic rats.
- Oxidative stress
- Spirulina maxima
- Accesso libero
Modelling of absorption, distribution and physicochemical properties of AT1 receptor antagonists / Modelovanie absorpcie, distribúcie a fyzikálnochemických vlastnosti antagonistov AT1 receptorov
Pagine: 20 - 31
The theoretical chemistry methods were used to elucidate absorption, distribution and physicochemical properties of AT1 receptor antagonists and dual angiotensin II and endothelin A receptor antagonist (PS-433540). Computed partition coefficients (ALOGPS method) studied for drugs varied between 2.98 and 6.66. Neutral compounds are described as lipophilic drugs. Telmisartan is a drug with the highest lipophilicity. The neutral forms of the studied AT1 receptor antagonists are practically insoluble in water, and their computed solubilities is in interval between 2.04 and 22.65 mg/l (ALOGpS method). The calculated pKa values for tetrazolyle moiety are in the range 3.92-5.00 and for carboxylic moiety 3.12-5.50. Telmisartan (polar surface area = 72.95 A) and irbesartan (polar surface area = 87.14 A) belong to the AT1 receptor antagonists with increased absorption.
- AT1 receptor antagonists
- physicochemical properties
- Accesso libero
Phenylcarbamic acid derivatives with integrated n-phenylpiperazine moiety in the structure – kinetics of alkaline hydrolysis study / Deriváty kyseliny fenylkarbámovej s integrovanou n-fenylpiperazínovou zložkou v štruktúre – štúdium kinetiky alkalickej hydrolýzy
Pagine: 38 - 42
In present work, we have studied kinetics of alkaline hydrolysis of 14 compounds, which are phenylcarbamic acid derivatives with integrated N-phenylpiperazine moiety in the structure. The compounds possessed moderate antiarrhythmic and antimycobacterial activity. Their hydrolysis was carried out in an aqueous medium ethanol sodium hydroxide solution. The course of the hydrolysis was observed spectrophotometrically in visible as well as in ultraviolet regions. The pseudo-first order rate constants were calculated at several temperatures. The values of the activation energy EA were determined by the Arrhenius equation. The rate of hydrolysis of the compounds under the study increase with the increase in temperature and it has been differentiated according to the substitution of N-phenylpiperazine as well as to the alkoxy substitution on phenyl ring.
- Phenylcarbamic acid derivatives
- Alkaline hydrolysis
- Chemical kinetics
- Accesso libero
Increased expression and secretion of recombinant hIFNγ through amino acid starvation-induced selective pressure on the adjacent HIS4 gene in Pichia pastoris
Pagine: 43 - 50
Transcriptional co-regulation of adjacent genes has been observed for prokaryotic and eukaryotic organisms, alike. High levels of gene adjacency were also found in a wide variety of yeast species with a high frequency of co-regulated gene sets. The aim of this research was to study how selective pressure on the Histidinol dehydrogenase gene (HIS4), using amino acid starvation, affects the level of expression and secretion of the adjacent human interferon gamma gene (hIFNγ) in the recombinant Pichia pastoris GS115 strain, a histidine-deficient mutant. hIFNγ was cloned into the pPIC9 vector adjacent to the HIS4 gene, a gene essential for histidine biosynthesis, which was then transformed into P. pastoris. The transformed P. pastoris was cultured under continuous amino acid starvation in amino acid-free minimal medium for ten days, with five inoculations into unspent medium every second day. Under these conditions, only successfully transformed cells (hIFNγ -HIS4+) are able to synthesise histidine and therefore thrive. As shown by ELISA, amino acid starvation-induced selective pressure on HIS4 improved expression and secretion of the adjacent hIFNγ by 55% compared to unchallenged cells. RT-qPCR showed that there was also a positive correlation between duration of amino acid starvation and increased levels of the hIFNγ RNA transcripts. According to these results, it is suggested that these adjacent genes (hIFNγ and HIS4) in the transformed P. pastoris are transcriptionally co-regulated and their expression is synchronised. To the best of the knowledge of the authors; this is the first study demonstrating that amino acid starvationinduced selective pressure on HIS4 can alter the regulation pattern of adjacent genes in P. pastoris.
- Human interferon gamma
- Histidinol dehydrogenase
- Serial passage
- Transcriptional co-regulation