Brza i osjetljiva HPLC metoda za određivanje doksorubicina u krvi psa Artifakt srebrovog nitrata

A rapid and sensitive high performance liquid chromatographic (HPLC) assay utilizing fluorimetric detection (excitation at 480 nm, emission at 560 nm) for the determination of doxorubicin in dog blood was developed and validated. Treatment of blood samples containing doxorubicin with AgNO3 (as protein precipitant) resulted in appearance of an additional peak in the chromatogram of doxorubicin at 11.5 min along with the parent peak (tR = 5.5 min). The latter peak was not found when treated with other protein precipitants such as trichloroacetic acid and methanol. Construction of calibration curve based on area of both peaks alone did not result in linearity of the curve. However, summation of areas of both peaks resulted in a curve with good linearity and correlation coefficient (R2 = 0.9985). Appearance of second peak may be due to the interaction of doxorubicin with cellular components of blood in the presence of AgNO3 leading to the formation of complex with reduced polarity. Analysis of the quality control samples showed good accuracy (96.7-100.42) and precision (RSD = 2,6-5,7%). The proposed method could be advantageous in estimation of doxorubicin incorporated into targeted delivery systems that concentrate in blood cells and quantify the absolute blood concentration of doxorubicin.Razvijena je i validirana brza i osjetljiva metoda visokotlačne tekućinske kromatografije (HPLC) s fluorimetrijskom detekcijom za određivanje doksorubicina u krvi psa. Nakon obrade uzoraka krvi koji sadrže doksorubicin s AgNO3 (taložno sredstvo za proteine), uz osnovni signal (tR = 5,5min) pojavljuje se dodatni signal u kromatogramu doksorubicina na 11,5 min. Nikakav dodatni signal se ne pojavljuje ako se za taloženje proteina upotrijebe trikloroctena kiselina ili metanol. Međutim, u hemoliziranim uzorcima plazme kojima je dodan doksorubicin nakon obrade sa srebrovim nitratom pojavljuje se drugi signal. Kalibracijska krivulja s površinom ispod signala za samo prvi pik (tR = 5,5min) nije linearna. Međutim, suma površina ispod prvog (tR = 5.5min) i drugog signala (tR = 11.5min) daje linearnu zavisnost s korelacijskim koeficijentom R2 = 0,9985. Pojava drugog signala mogla bi biti posljedica interakcije doksorubicina sa staničnim komponentama u krvi u prisutnosti AgNO3 te nastajanja kompleksa smanjene polarnosti. Površina ispod signala na kromatogramu određena na temelju fluorescencijske detekcije na 480 nm i 560 nm (valne duljine pobuđivanja, odnosno emisije) upotrebljena je za kvantitativnu analizu doksorubicina. Određivanje doksorubicina u krvi psa je jednostavna, precizna i točna. U svim eksperimentima, relativna standardna devijacija (RSD) najčešće je bila < 10%, a izmjerena i teorijska koncentracija razlikovala se za < 10%. Doksorubicin inkubiran s uzorcima krvi psa bio je stabilan najmanje 3 dana ako je čuvan na 5 °C, odnosno najmanje 8 h ako je čuvan na sobnoj temperaturi (28 °C). Predložena HPLC metoda mogla bi imati prednosti u određivanju doksorubicina u sustavima za isporuku lijekova ciljano u krvne stanice i kvantifikaciji ukupne koncentracije doksorubicina u krvi

Brza i osjetljiva HPLC metoda za određivanje doksorubicina u krvi psa Artifakt srebrovog nitrata

A rapid and sensitive high performance liquid chromatographic (HPLC) assay utilizing fluorimetric detection (excitation at 480 nm, emission at 560 nm) for the determination of doxorubicin in dog blood was developed and validated. Treatment of blood samples containing doxorubicin with AgNO3 (as protein precipitant) resulted in appearance of an additional peak in the chromatogram of doxorubicin at 11.5 min along with the parent peak (tR = 5.5 min). The latter peak was not found when treated with other protein precipitants such as trichloroacetic acid and methanol. Construction of calibration curve based on area of both peaks alone did not result in linearity of the curve. However, summation of areas of both peaks resulted in a curve with good linearity and correlation coefficient (R2 = 0.9985). Appearance of second peak may be due to the interaction of doxorubicin with cellular components of blood in the presence of AgNO3 leading to the formation of complex with reduced polarity. Analysis of the quality control samples showed good accuracy (96.7-100.42) and precision (RSD = 2,6-5,7%). The proposed method could be advantageous in estimation of doxorubicin incorporated into targeted delivery systems that concentrate in blood cells and quantify the absolute blood concentration of doxorubicin.Razvijena je i validirana brza i osjetljiva metoda visokotlačne tekućinske kromatografije (HPLC) s fluorimetrijskom detekcijom za određivanje doksorubicina u krvi psa. Nakon obrade uzoraka krvi koji sadrže doksorubicin s AgNO3 (taložno sredstvo za proteine), uz osnovni signal (tR = 5,5min) pojavljuje se dodatni signal u kromatogramu doksorubicina na 11,5 min. Nikakav dodatni signal se ne pojavljuje ako se za taloženje proteina upotrijebe trikloroctena kiselina ili metanol. Međutim, u hemoliziranim uzorcima plazme kojima je dodan doksorubicin nakon obrade sa srebrovim nitratom pojavljuje se drugi signal. Kalibracijska krivulja s površinom ispod signala za samo prvi pik (tR = 5,5min) nije linearna. Međutim, suma površina ispod prvog (tR = 5.5min) i drugog signala (tR = 11.5min) daje linearnu zavisnost s korelacijskim koeficijentom R2 = 0,9985. Pojava drugog signala mogla bi biti posljedica interakcije doksorubicina sa staničnim komponentama u krvi u prisutnosti AgNO3 te nastajanja kompleksa smanjene polarnosti. Površina ispod signala na kromatogramu određena na temelju fluorescencijske detekcije na 480 nm i 560 nm (valne duljine pobuđivanja, odnosno emisije) upotrebljena je za kvantitativnu analizu doksorubicina. Određivanje doksorubicina u krvi psa je jednostavna, precizna i točna. U svim eksperimentima, relativna standardna devijacija (RSD) najčešće je bila < 10%, a izmjerena i teorijska koncentracija razlikovala se za < 10%. Doksorubicin inkubiran s uzorcima krvi psa bio je stabilan najmanje 3 dana ako je čuvan na 5 °C, odnosno najmanje 8 h ako je čuvan na sobnoj temperaturi (28 °C). Predložena HPLC metoda mogla bi imati prednosti u određivanju doksorubicina u sustavima za isporuku lijekova ciljano u krvne stanice i kvantifikaciji ukupne koncentracije doksorubicina u krvi

Brza i osjetljiva HPLC metoda za određivanje doksorubicina u krvi psa Artifakt srebrovog nitrata

A rapid and sensitive high performance liquid chromatographic (HPLC) assay utilizing fluorimetric detection (excitation at 480 nm, emission at 560 nm) for the determination of doxorubicin in dog blood was developed and validated. Treatment of blood samples containing doxorubicin with AgNO3 (as protein precipitant) resulted in appearance of an additional peak in the chromatogram of doxorubicin at 11.5 min along with the parent peak (tR = 5.5 min). The latter peak was not found when treated with other protein precipitants such as trichloroacetic acid and methanol. Construction of calibration curve based on area of both peaks alone did not result in linearity of the curve. However, summation of areas of both peaks resulted in a curve with good linearity and correlation coefficient (R2 = 0.9985). Appearance of second peak may be due to the interaction of doxorubicin with cellular components of blood in the presence of AgNO3 leading to the formation of complex with reduced polarity. Analysis of the quality control samples showed good accuracy (96.7-100.42) and precision (RSD = 2,6-5,7%). The proposed method could be advantageous in estimation of doxorubicin incorporated into targeted delivery systems that concentrate in blood cells and quantify the absolute blood concentration of doxorubicin.Razvijena je i validirana brza i osjetljiva metoda visokotlačne tekućinske kromatografije (HPLC) s fluorimetrijskom detekcijom za određivanje doksorubicina u krvi psa. Nakon obrade uzoraka krvi koji sadrže doksorubicin s AgNO3 (taložno sredstvo za proteine), uz osnovni signal (tR = 5,5min) pojavljuje se dodatni signal u kromatogramu doksorubicina na 11,5 min. Nikakav dodatni signal se ne pojavljuje ako se za taloženje proteina upotrijebe trikloroctena kiselina ili metanol. Međutim, u hemoliziranim uzorcima plazme kojima je dodan doksorubicin nakon obrade sa srebrovim nitratom pojavljuje se drugi signal. Kalibracijska krivulja s površinom ispod signala za samo prvi pik (tR = 5,5min) nije linearna. Međutim, suma površina ispod prvog (tR = 5.5min) i drugog signala (tR = 11.5min) daje linearnu zavisnost s korelacijskim koeficijentom R2 = 0,9985. Pojava drugog signala mogla bi biti posljedica interakcije doksorubicina sa staničnim komponentama u krvi u prisutnosti AgNO3 te nastajanja kompleksa smanjene polarnosti. Površina ispod signala na kromatogramu određena na temelju fluorescencijske detekcije na 480 nm i 560 nm (valne duljine pobuđivanja, odnosno emisije) upotrebljena je za kvantitativnu analizu doksorubicina. Određivanje doksorubicina u krvi psa je jednostavna, precizna i točna. U svim eksperimentima, relativna standardna devijacija (RSD) najčešće je bila < 10%, a izmjerena i teorijska koncentracija razlikovala se za < 10%. Doksorubicin inkubiran s uzorcima krvi psa bio je stabilan najmanje 3 dana ako je čuvan na 5 °C, odnosno najmanje 8 h ako je čuvan na sobnoj temperaturi (28 °C). Predložena HPLC metoda mogla bi imati prednosti u određivanju doksorubicina u sustavima za isporuku lijekova ciljano u krvne stanice i kvantifikaciji ukupne koncentracije doksorubicina u krvi

Thigh-length compression stockings and DVT after stroke

Controversy exists as to whether neoadjuvant chemotherapy improves survival in patients with invasive bladder cancer, despite randomised controlled trials of more than 3000 patients. We undertook a systematic review and meta-analysis to assess the effect of such treatment on survival in patients with this disease

Azithromycin in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Background Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatory actions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19. Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospital with COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients were randomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once per day by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatment groups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment and were twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants and local study staff were not masked to the allocated treatment, but all others involved in the trial were masked to the outcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treat population. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936. Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) were eligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was 65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomly allocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall, 561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days (rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median 10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days (rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, no significant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilation or death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24). Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or other prespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restricted to patients in whom there is a clear antimicrobial indication. Funding UK Research and Innovation (Medical Research Council) and National Institute of Health Research