脂质体阿苯达唑及主要代谢产物的HPLC法和药代动力学研究

作者报道了动物(鼠)口服脂质体阿苯达唑后血浆、肝脏、包虫囊组织和囊液中阿苯达唑及主要代谢产物阿苯达唑砜和阿苯达唑亚砜的反相HPLC法。同时进行了药物动力学研究和并用西咪替丁后对血、肝药物浓度的影响。结果表明,阿苯达唑在血浆、囊液中的检出限为0.05μg/ml,在肝脏和囊组织中为0.10μg/g;砜和亚砜在血浆、囊液中均为0.01μg/ml,在肝脏和囊组织中均为0.02μg/g。药物动力学结果显示,阿苯达唑脂质体、混悬液及脂质体并用西咪替丁后的体内过程均符合二室模型,混悬液并用西咪替丁后符合单室模型。阿苯达唑脂质体具有一定的缓释及靶向的作用,西咪替丁可能增强阿苯达唑的缓释作用,同时可能加速阿苯达唑亚砜的代谢。     

二甲基亚砜和珍黄注射液联合用药对小鼠宫颈癌的抗癌作用

目的：探讨二甲基亚砜（Dimethl Sulphoxide,DMSO)和珍黄注射液（Zhenhuang injection,ZHI)联合用药对小鼠宫颈癌的抗癌作用,为临床试验提供科学依据。方法：用DMSO（50mg/kg),ZHI（20mg/kg),DMSO ZHI(DMSO 50mg/kg,ZHI 20mg/kg)分别对小鼠宫颈癌U14腹水瘤模型和实体瘤模型进行治疗,以生命延长率和抑瘤率作为疗效评价指标。实验重复两次,结果：在腹水瘤治疗实验,DMSO组,ZHI组,DMSO＋ZHI组的生命延长率分别为21．37％－25．86％,41．38％－43．59％,65．81％－69．83％,经统计学分析,三个治疗组与对照组比较均有极显著性差异（P＜0．01）,联合用药组（DMSO＋ZHI组）与单药组（DMSO组或ZHI组）比较均有极显著性差异（P＜0．01）,在实体瘤治疗实验,DMSO组,ZHI组,DMSO＋ZHI组的抑瘤率分别为22．50％,25．83％,37．50％,41．67％,60．83％,68．33％,经统计学分析,三个治疗组与对照组比较均有显著或极显著性差异（P＜0．05或P＜0．01）,联合用药组与单药组比较均有极显著性差异（P＜0．01）,结论：ZHI对小鼠宫颈癌U14有一定的抗癌作用,DMSO和ZHI联合用药能起增效作用。     

Indocyanine green loaded hyaluronan-derived nanoparticles for fluorescence-enhanced surgical imaging of pancreatic cancer

Pancreatic ductal adenocarcinoma is highly lethal and surgical resection is the only potential curative treatment for the disease. In this study, hyaluronic acid derived nanoparticles with physico-chemically entrapped indocyanine green, termed NanoICG, were utilized for intraoperative near infrared fluorescence detection of pancreatic cancer. NanoICG was not cytotoxic to healthy pancreatic epithelial cells and did not induce chemotaxis or phagocytosis, it accumulated significantly within the pancreas in an orthotopic pancreatic ductal adenocarcinoma model, and demonstrated contrast-enhancement for pancreatic lesions relative to non-diseased portions of the pancreas. Fluorescence microscopy showed higher fluorescence intensity in pancreatic lesions and splenic metastases due to NanoICG compared to ICG alone. The in vivo safety profile of NanoICG, including, biochemical, hematological, and pathological analysis of NanoICG-treated healthy mice, indicates negligible toxicity. These results suggest that NanoICG is a promising contrast agent for intraoperative detection of pancreatic tumors.     

RP-HPLC 测定人血浆中阿苯达唑及代谢物的浓度

 目的 建立 RP-HPLC 测定血浆中阿苯达唑及其代谢物阿苯达唑亚砜、阿苯达唑砜浓度的方法。 方法 在改进文献报道的基础上,采用 C ₂ 柱固相萃取法处理血浆,建立了精确、灵敏、重现性和专一性好的高效液相 - 紫外检测法（ HPLC-UV ）。色谱条件：分析柱： Agilent Zorbax RX-C₈ （ 4.6 mm×250 mm , 5 μm ）;柱温：室温;流动相：乙腈 -NaAc 缓冲液（ 0.1 mol·L^-1 , HAc 调节 pH 5.0 ） =45 ∶ 55 ,流速 0.9 mL·min^-1 ,检测波长 291 nm 。 结果 阿苯达唑及其代谢物阿苯达唑亚砜、阿苯达唑砜的血药浓度线性范围分别为 10~600 , 10~1 000 , 10~300 μg·L^-1 ;方法回收率分别为 92.23% ~ 103.81% , 99.59% ~ 100.21% , 96.89% ~ 106.84% 。 批内精密度分别为 2.03%~3.12% , 2.05%~3.80% , 2.79%~4.14% ;批间精密度分别为 3.20% ～ 4.33% , 2.05%~3.48% , 2.87%~3.87% 。 结论 本法灵敏、准确,可用于阿苯达唑的人体药动学研究。     

Effects of methyl prednisolone,dimethyl sulphoxide and naloxone in experimental spinal cord injuries in rats

The effects of methyl prednisolone (MPD), dimethyl sulphoxide (DMSO), and naloxone were examined in 38 albino rats after making an impact spinal cord injury on the midthoracic segments with a modified Allen’s weight dropping trauma method. Somatosensorial evoked potentials (SEPs) were recorded before and 12 h and 14 d after the injury from epidurally inserted electrodes on the parietal cortex with sciatic nerve stimulations. Lower extremity, motor functions of the animals were also examined. It may be concluded that in this study model, DMSO has a moderate effect which can be demonstrated clinically and through SEPs. Naloxone has no effect on the clinical outcome but causes reasonable improvement electro-physiologically.     

Methylthiomethyl,a new carboxyl protecting group in peptide synthesis

N^α-protected amino acid methylthiomethyl esters (MTM) were obtained in good yields under mild conditions using the «Bu^tBr/Me₂SO» reagent. Selective removal of the N-protecting group was achieved in HCl/anhydrous ethyl ether and the MTM ester hydrochlorides were successfully used in the synthesis of dipeptides.     

A methylester of the glucuronide prodrug DOX-GA3 for improvement of tumor-selective chemotherapy

The glucuronide prodrug of doxorubicin, DOX-GA3, can be selectively activated in tumors by extracellular human beta-glucuronidase, resulting in a better therapeutic index than doxorubicin. DOX-GA3, however, is rapidly excreted by the kidney. We hypothesized that slow release of DOX-GA3 from its methylester, DOX-mGA3, by esterase activity in blood would result in improved circulation half-life (t(1/2)) of DOX-GA3. DOX-mGA3 was synthesized more efficiently with an overall yield of 60% as compared to 37% in the case of DOX-GA3. We showed that DOX-mGA3 was enzymatically converted to DOX-GA3 with a t(1/2) of approximately 0.5 min in mouse plasma to 2.5 h in human plasma, which was in agreement with differences in esterase activity between species. DOX-mGA3, similar to DOX-GA3, was at least 37-fold less potent than the parent drug doxorubicin in growth inhibition of four different human malignant cell lines in vitro. Incubation of OVCAR-3 cells with DOX-mGA3 in combination with an excess of human beta-glucuronidase (0.05 U mL(-1)) resulted in a similar growth inhibition to that of doxorubicin. Intravenous administration of DOX-mGA3 in FMa-bearing mice resulted in an area under the concentration versus time curve (AUC) of DOX-GA3 in tumor and most normal tissues that was 2.5- to 3-fold higher than after the same dose of DOX-GA3 itself. In tumor tissue, this was accompanied by a 2.7-fold increase in the AUC of doxorubicin from DOX-mGA3 than from DOX-GA3. In conclusion, an advantage of DOX-mGA3 over DOX-GA3 is that this prodrug can be produced with a higher yield. Another important advantage is the improved pharmacokinetics of the lipophilic DOX-mGA3 as compared to that of the hydrophilic DOX-GA3. This effect may even be more pronounced in man, because of the lower plasma esterase activity than measured in mice.     

Effect of metamizol on promyelocytic and terminally differentiated granulocytic cells. Comparative analysis with acetylsalicylic acid and diclofenac

Metamizol is an analgesic and antipyretic agent that can induce agranulocytosis in certain patients. However, its effects on granulocyte viability and differentiation have been poorly evaluated. Here we analysed the effects of metamizol and its active metabolite, 4-methylaminoantipyrine (MAA), on the viability of HL60 promyelocytes and their dimethyl sulphoxide-induced differentiated granulocytes. Metamizol and MAA at 75 microM (above the peak of plasmatic concentration after 2g intake) did not alter granulocytic differentiation of HL60 cells. Only at concentrations above 100 microM, well over the pharmacological range, metamizol-induced apoptosis in about 30% of the HL60 promyelocytes, while HL60-granulocytic terminally differentiated cells were more resistant to this apoptotic action. When the effects of metamizol were compared with those of acetylsalicylic acid (ASA) and diclofenac on cell viability, at equivalent concentrations used in analgesic and antipyretic therapy (75 microM for metamizol, and ASA and 3 microM for diclofenac) their apoptotic effects were similar. Again, the HL60 promyelocytes were more sensitive to apoptosis than granulocytic differentiated cells, as measured by the percentage of sub-G(1) cells detected by flow cytometry and by determination of caspase activity as a function of poly(ADP-ribose) polymerase cleavage. Furthermore, when human blood-derived granulocytes were treated with metamizol, MAA, and ASA at 75 microM or diclofenac at 3 microM, less than 10% of apoptotic granulocytes were detected, whereas at toxicological/suprapharmacological concentrations (10mM), about 90% of granulocytes were apoptotic. These results demonstrate that metamizol, MAA, ASA, and diclofenac, at pharmacological concentrations, neither affect the granulocytic differentiation process nor induce relevant apoptosis on terminally differentiated granulocytes.     

Relevance of mitogen activated protein kinase (MAPK) and phosphotidylinositol-3-kinase/protein kinase B (PI3K/PKB) pathways to induction of apoptosis by curcumin in breast cells

Following observations that curcumin inhibited proliferation (IC(50)=1-5 microM), invasiveness and progression through S/G2/M phases of the cell cycle in the non-tumourigenic HBL100 and tumourigenic MDA-MB-468 human breast cell lines, it was noted that apoptosis was much more pronounced in the tumour line. Therefore, the ability of curcumin to modulate signalling pathways which might contribute to cell survival was investigated. After pre-treatment of cells for 20 min, curcumin (40 microM) inhibited EGF-stimulated phosphorylation of the EGFR in MDA-MB-468 cells and phosphorylation of extracellular signal regulated kinases (ERKs) 1 and 2, as well as ERK activity and levels of nuclear c-fos in both cell lines. At a lower dose (10 microM), it also inhibited the ability of anisomycin to activate JNK, resulting in decreased c-jun phosphorylation, although it did not inhibit JNK activity directly. In contrast, the activation of p38 mitogen activated protein kinase (MAPK) by anisomycin was not inhibited. Curcumin inhibited basal phosphorylation of Akt/protein kinase B (PKB) in both cell lines, but more consistently and to a greater extent in the MDA-MB-468 cells. The MAPK kinase (MKK) inhibitor U0126 (10 microM), while preventing ERK phosphorylation in MDA-MB-468 cells, did not induce apoptosis. The PI3K inhibitor LY294002 (50 microM) inhibited PKB phosphorylation in both cells lines, but only induced apoptosis in the MDA-MB-468 line. These results suggest that while curcumin has several different molecular targets within the MAPK and PI3K/PKB signalling pathways that could contribute to inhibition of proliferation and induction of apoptosis, inhibition of basal activity of Akt/PKB, but not ERK, may facilitate apoptosis in the tumour cell line.     

A cleavage cocktail for methionine-containing peptides

Abstract: A new cocktail has been developed for cleavage and deprotection of methionine-containing peptides synthesized by 9-fluorenylmethoxycarbonyl (Fmoc)-based solid-phase peptide synthesis methodology. The cocktail (trifluoroacetic acid 81%, phenol 5%, thioanisole 5%, 1,2-ethanedithiol 2.5%, water 3%, dimethylsulphide 2%, ammonium iodide 1.5% w/w) was designed to minimize methionine side-chain oxidation. Application of the new cocktail (Reagent H) is demonstrated with the synthesis of a model pentadecapeptide from the active site of DsbC, a periplasmic protein involved in protein disulphide bond formation. The model peptide, which contains one methionine and two cysteine residues, was cleaved with several cleavage cocktails, including Reagent H. The crude peptides obtained with the widely used cocktails K, R and B were found to be 15% to 55% in the methionine sulphoxide form, whereas no methionine sulphoxide was detected in the crude peptide obtained by cleavage and deprotection with Reagent H. Also, no methionine sulphoxide was detected when 1.5% w/w NH₄I was added to cocktails K, R and B; however, the yield of the desired peptide was less than with Reagent H. A second 28 amino acid model peptide of the active site of DsbC was also cleaved and deprotected with Reagent H. The reduced dithiol form of the peptide was found to be the major component (51% yield) of the crude peptide obtained by cleavage for 3 h. When the cleavage time was extended to 10 h, the peptide was converted to the intramolecular disulphide form (35% yield). A proposed mechanism for the in situ oxidation of cysteine with Reagent H is presented.