Arrhythmias, Cardiac ; etiology ; prevention & control ; Cardiac Pacing, Artificial ; adverse effects ; methods ; Humans

With the in-depth study of related substances and the development of consistency evaluation of generic drugs, relative correction factors are gaining increasing attention. By analyzing the domestic and foreign literature on correction factors in recent years, this paper describes the correction factor component, the current measurement method and its application. The rules and key points of use of an impurity correction factor and its determination and application are described, and some problems in its determination and application are discussed, providing a reference and basis for the standardization of research on impurity correction factors in the future.

The quality of some earlier developed antibiotics is usually ensured by the combination of HPLC purity and microbiological potency measurement in the pharmacopoeias of various countries because the relationship between their purity and potency is not clearly quantified. Due to potency is assessed using certain units of measurement, it can not be directly traced to the international system of units (SI unit). This has become a hotspot in the study of the quantitative relationship between purity and potency of antibiotics. It would be quite an achievement to simultaneously determine both purity and potency using HPLC methods during quality control. This study evaluated a multicomponent antibiotic product, gentamycin, as a test sample. First, pure samples of the C components of gentamycin: C1a, C2, C2a and C1 were prepared, separately. Second, quantitative relationship (theoretical potency) between the purity and potency of each C component of gentamycin were determined using 1H NMR, HPLC-ELSD and microbiological assay method. One milligram of gentamycin C1a, C2, C2a and C1 was equal to 1 286.98, 1 095.74, 1 079.52 and 739.61 gentamycin units, respectively. Finally, a method for the determination of gentamycin potency was established based on the proportion and content of C components of gentamycin. The unification of purity and potency for gentamycin was achieved using only HPLC-ELSD. It is also demonstrated that C components of gentamycin and micronomicin produce the same responses under ELSD, which means that it is not necessary to prepare separate reference standards for each C component of gentamycin and that quantitative testing can be performed accurately using only one micronomicin reference standard. This study simplified the previous method for the determination of the content of C components of gentamycin using HPLC-ELSD. The developed method is suitable for regular use as a part of quality control and can simplify the rigmarole quality control procedures provided in current pharmacopeias.
Chromatography, High Pressure Liquid ; Gentamicins ; chemistry ; pharmacology ; Magnetic Resonance Spectroscopy ; Microbial Sensitivity Tests ; methods ; Molecular Structure ; Quality Control ; Reference Standards

Research on polymer impurities has always been important in the quality control of cephalosporins. Research on polymers in cephalosporins that lack active amino groups on the C-7 side chain has not been reported. Therefore, our study used cefazolin sodium, which is widely used in the clinic, as an example. The polymer in cefazolin sodium and its product "cefazolin sodium pentahydrate for injection" was analyzed by column switching liquid chromatography-high resolution mass spectrometry. Two polymer impurity peaks were detected and the possible structures of these polymers were suggested. Through two-dimensional liquid chromatography, the chromatographic peaks following Sephadex gel chromatography and high-performance gel chromatography were compared to those obtained by reverse high-performance liquid chromatography (HPLC) for cefazolin sodium as reported in the Chinese Pharmacopoeia. The HPLC method proves more suitable for polymer detection than Sephadex gel chromatography and high-performance gel chromatography. The method of polymer detection for cefazolin sodium was established using the method of related substances HPLC as described in the Chinese Pharmacopoeia.

BackgroundChoriodal neovascularization is an important ocular manifestation of angiogenesis in eyes,which derives from the choroid capillaries.Recent studies have found that complement activation is playing a key role in the laser-induced CNV.Because of the key position of CFB in the alternative pathway,bytargeting CFB and blocking the alternative pathway may provide an approach to observe the role of this alternative pathway in the generation of CNV.Objective This study was to investigate the inhibitory effect of reconstructed complement factor B (CFB)-small interfering ribonucleicacid(siRNA)on choroidal neovascularization (CNV)and its mechanism. Methods Experimental CNV was induced by laser photocoagulation in 96 eyes of 48 clean Brown Norway rats.The rats were randomly divided into 4 groups.25,50 and 75 μg B factor siRNA were injected via caudal vein on 1 day,3,5 days after photocoagulation in different dose groups,and normal saline solution was injected at the same way in experimental control group.Other 12 normal rats were used as blank control group.Fundus fluorescein angiography(FFA) was performed on 3,7,14,21,28 days after injection of CFB-siRNA and CNV was scored.The expressions of vascular endothelial growth factor(VEGF) and factor Ⅷ in choroid were detected by immunochemistry.The expressions of CFB-siRNA,VEGF,transforming growth factor β2( TGF-β2 )proteins in choroid were determined using immunochemistry in 7,14,21,28 days,and the expressions of mRNA of CFB-siRNA,VEGF,TGF-β2 were examined by reverse transcription polymerase chain reaction(RT-PCR). ResultsFFA revealed that the CNV rates in various doses of CFB-siRNA groups were significant lower than those of experimental control group in various time points(P＜0.05),and those in 75 μg B factor siRNA were decreased in comparison with 25 μg B factor siRNA (P＜0.05).Immunochemistry showed that the intensities of the VEGF and factor Ⅶ expression in various doses of CFB-siRNA groups were weaker than the blank control group ( P ＜ 0.05 ).Compared with the control group,the expression of CFB reduced in 7 days,and then approached to the level near the control group.Fourteen to twenty-one days after injection of CFB-siRNA,VEGF and TGF-β2 depressions in different doses of CFB-siRNA groups were lower than blank control group( P＜0.05 ).CFB expression in choroid showed the lower levels in CFB-siRNA injection group compared with blank control group in from 7 through 21 days (P＜0.05).RT-PCR displayed the gradual increase of CFB mRNA and curve-like changes of VEGF and TGF-β2 with time prolong. Conclusions Recombinated CFB-siRNA can effectively inhibit laser-induced CNV by down-regulating the expression of VEGF and factor Ⅷ.Alternative pathway of complement plays an important role in the production of CNV.

This paper was aimed to investigate the effects of ATP-sensitive potassium channels on the proliferation and differentiation of rat preadipocytes. We examined the expression of sulphonylurea receptor 2 (SUR2) mRNA in preadipocytes and adipocytes obtained by inducing for 5 d and the effects of the inhibitor (glibenclamide) and opener (diazoxide) of ATP-sensitive potassium channels on the expression of SUR2 mRNA in preadipocytes by real-time PCR. Preadipocyte proliferation and cell cycle were measured by MTT spectrophotometry and flow cytometer. The content of intracellular lipid was measured by oil red O staining, cell diameter was determined by Image-Pro Plus 5.0 software and the expression of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) mRNA was estimated by RT-PCR. SUR2 mRNA was expressed in both preadipocytes and adipocytes obtained by inducing for 5 d, and the expression in adipocytes was obviously higher than that in preadipocytes. Glibenclamide inhibited the expression of SUR2 mRNA in preadipocyte, promoted preadipocyte proliferation in a dose-dependent manner, increased the cell percentages in G(2)/M + S phase, increased lipid content, augmented adipocyte diameter, and promoted the expression of PPAR-gamma mRNA. But the actions of diazoxide were contrary to those of glibenclamide. These results suggest that ATP-sensitive potassium channels regulate the proliferation and differentiation of preadipocytes, and PPAR-gamma is probably involved in the effect of ATP-sensitive potassium channels.
ATP-Binding Cassette Transporters ; genetics ; metabolism ; Adipocytes ; cytology ; Animals ; Cell Differentiation ; physiology ; Cell Proliferation ; Cells, Cultured ; KATP Channels ; physiology ; Male ; Obesity ; pathology ; PPAR gamma ; metabolism ; Potassium Channels, Inwardly Rectifying ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Drug ; genetics ; metabolism ; Sulfonylurea Receptors

Objective: To evaluate the prognostic significance of minimal residual disease (MRD) monitoring by 10-color flow cytometry in multiple myeloma (MM) patients after treatment. Methods: 150 patients with MM who were admitted to the First Affiliated Hospital of Soochow University from July 2015 to July 2017 were retrospectively analyzed. Clinical data, MRD data monitoring by 10-color flow cytometry and prognosis were analyzed. Results: 39.1% (34/87) patients were MRD negative after induction chemotherapy, and 49.3% (34/69) patients were MRD negative within 1 year after autologous hematopoietic stem cell transplantation (ASCT) . MRD-negative patients after induction chemotherapy or after transplantation have better progress-free survival (PFS) than MRD-positive patients (P=0.022 and P<0.001) . According to the changes of MRD pre-ASCT and after ASCT, the patients were divided into 4 groups: patients with MRD continued negativity,improved from MRD positive to MRD negative, MRD continued positivity, transformed from MRD negative to MRD positive. The two-year PFS of the four groups were 83%, 82%, 44%, 0, respectively, (P=0.002) . Multivariate analysis showed that the level of MRD after induction chemotherapy was an independent factor for PFS (P=0.002) , HR=4.808 (95%CI 1.818-12.718) . Conclusion: Patients with MRD negative after treatment is a better prognosis marker than complete remission or even the best marker, which can evaluate prognosis by combining R-ISS and cytogenetic changes.
Flow Cytometry ; Humans ; Multiple Myeloma/diagnosis* ; Neoplasm, Residual ; Prognosis ; Retrospective Studies ; Transplantation, Autologous

Tracheal intubation with Macintosh laryngoscope (MAC) might result in severe cardiovascular complications. The results of conducted studies investigating the effects of videolaryngoscopies on hemodynamic response of tracheal intubation are conflicting. We know little about the effects of videolaryngoscopies on cardiac output changes during tracheal intubation. We compared cardiac output (COP) and hemodynamic responses in normal blood pressure (n=60) and hypertensive patients (n=60) among 3 intubation devices: the MAC, the UE videolaryngoscopy ® (UE), and the UE video intubation stylet ® (VS). Cardiac index (CI), stroke volume index (SVI), heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were recorded using LidcoRapid (V2)® preinduction, preintubation, and every minute for the first 5 min after intubation. We assessed oropharyngeal and laryngeal structures injury as well. Intubation time was significantly shorter than MAC groups (P<0.001) only in UE group of normotensive and hypertensive patients. In normotensive patients, there were no significant differences in any of COP variables or hemodynamic variables among the three devices. In hypertensive patients, SBP and DBP in the MAC group were significantly higher (P<0.05 or <0.01) than the UE and VS groups at 1, 2 and 3 min after intubation, but there were no significant differences in CI, SVI and HR among the three devices. There was no significant difference in oropharyngeal and laryngeal structures injury among all groups. It was concluded that both the UE and VS attenuate only the hemodynamic response to intubation as compared with the MAC in hypertensive patients, but not in normotensive patients.
Adult ; Aged ; Blood Pressure ; physiology ; Cardiac Output ; physiology ; Female ; Hemodynamics ; Humans ; Hypertension ; physiopathology ; surgery ; Intubation, Intratracheal ; instrumentation ; methods ; Laryngoscopy ; instrumentation ; methods ; Larynx ; anatomy & histology ; injuries ; Male ; Middle Aged ; Oropharynx ; anatomy & histology ; injuries ; Video-Assisted Surgery ; methods ; Young Adult

To establish a method for the determination of polymer impurities in ceftazidime raw materials and preparations, a ceftazidime degradation solution containing polymer impurities was prepared by forced polymerization. Polymer impurities in the degradation solution were separated and identified by high performance gel chromatography and the column switching-LC-MSⁿ method. A new RP-HPLC method for ceftazidime polymer was established and validated with a Phenomenex Gemini-C18 column using a mobile phase gradient elution of 0.02 mol·L^-1 phosphate buffer, methanol and acetonitrile. The results showed that when using this high performance gel chromatography method some small molecular weight impurities were co-eluted with the polymers, resulting in a poor specificity and poor quantitative accuracy. But when using the RP-HPLC method, four polymer impurities were detected in the 25-45 min time range with good specificity, sensitivity and robustness, including two ceftazidime dimers, trimers, and derivatives. Therefore, the described RP-HPLC method is suitable for the quality control of polymer impurities in ceftazidime, and ceftazidime degradation solution can be used as suitable solution for analysis of ceftazidime polymers.

To establish a method for the determination of polymer impurities in cefixime raw materials and preparations, a cefixime degradation solution containing polymer impurities was prepared by forced polymerization. Polymer impurities in the degradation solution were separated and identified by high performance gel chromatography and the column switching-LC-MSⁿ method. A new RP-HPLC method for cefixime polymer was established and validated with a Phenomenex Gemini-C18 column using a mobile phase gradient elution of 0.5% formic acid-water solution and 0.5% formic acid-acetonitrile solution. The results showed that when using this high performance gel chromatography method some small molecular weight impurities were co-eluted with the polymers, resulting in a poor specificity and poor quantitative accuracy. But when using the RP-HPLC method, three polymer impurities were detected with good specificity, sensitivity and robustness, including two cefixime dimers, and dehydrate dimer. Therefore, the described RP-HPLC method is suitable for the quality control of polymer impurities in cefixime, and cefixime degradation solution can be used as suitable solution for analysis of cefixime polymers.