Glycoprotein Ib and glycoprotein IX are fully complexed in the intact platelet membrane

Two new murine monoclonal antibodies, AK 1 and SZ 1, reactive with the human platelet glycoprotein (GP) Ib-IX complex have been produced by the hybridoma technique. Both AK 1 and SZ 1 immunoprecipitated the GP Ib-IX complex from Triton X-100-solubilized, periodate-labeled platelets. With trypsinized, labeled platelets, AK 1, SZ 1, and FMC 25 (epitope on GP IX) immunoprecipitated a membrane-bound proteolytic fragment of the GP Ib-IX complex consisting of GP IX and an congruent to 25,000 mol wt remnant of the alpha-chain of GP lb disulfide-linked to the beta-subunit. Unexpectedly, although AK 1 and SZ 1 immunoprecipitated purified GP Ib-IX complex, neither antibody immunoprecipitated the individual components of this complex, GP Ib or GP IX. When GP Ib and GP IX were recombined, however, AK 1 and SZ 1 again immunoprecipitated the reformed complex, strongly suggesting that both antibodies were recognizing an epitope present only on the intact complex. Cross-blocking studies indicated that AK 1 and SZ 1 recognized a very similar or identical epitope that was proximal to the epitope for FMC 25. Both AK 1 and SZ 1 bound to a similar number of binding sites (congruent to 25,000) on intact platelets as monoclonal antibodies directed against either GP lb or GP IX. The combined data suggests that GP lb and GP IX are fully complexed in the intact platelet membrane.     

Designer broad-spectrum polyimidazolium antibiotics

For a myriad of different reasons most antimicrobial peptides (AMPs) have failed to reach clinical application. Different AMPs have different shortcomings including but not limited to toxicity issues, potency, limited spectrum of activity, or reduced activity in situ. We synthesized several cationic peptide mimics, main-chain cationic polyimidazoliums (PIMs), and discovered that, although select PIMs show little acute mammalian cell toxicity, they are potent broad-spectrum antibiotics with activity against even pan-antibiotic-resistant gram-positive and gram-negative bacteria, and mycobacteria. We selected PIM1, a particularly potent PIM, for mechanistic studies. Our experiments indicate PIM1 binds bacterial cell membranes by hydrophobic and electrostatic interactions, enters cells, and ultimately kills bacteria. Unlike cationic AMPs, such as colistin (CST), PIM1 does not permeabilize cell membranes. We show that a membrane electric potential is required for PIM1 activity. In laboratory evolution experiments with the gram-positive Staphylococcus aureus we obtained PIM1-resistant isolates most of which had menaquinone mutations, and we found that a site-directed menaquinone mutation also conferred PIM1 resistance. In similar experiments with the gram-negative pathogen Pseudomonas aeruginosa, PIM1-resistant mutants did not emerge. Although PIM1 was efficacious as a topical agent, intraperitoneal administration of PIM1 in mice showed some toxicity. We synthesized a PIM1 derivative, PIM1D, which is less hydrophobic than PIM1. PIM1D did not show evidence of toxicity but retained antibacterial activity and showed efficacy in murine sepsis infections. Our evidence indicates the PIMs have potential as candidates for development of new drugs for treatment of pan-resistant bacterial infections.

AMPs and AMP mimics have attracted considerable attention as candidates for therapeutic development (1). The basic design elements include a region of charged residues, generally cationic residues, enabling interaction with bacterial cell surfaces, combined with a hydrophobic nature in AMPs (2). Unfortunately, AMPs and related polymers, in general, have one or more issues that limit their use as broad-spectrum antibiotics. Some are quite toxic to human cells, the potency of some is not adequate for human administration, others are sensitive to salt at levels present in human fluids, and some are too difficult and expensive to synthesize (3, 4). One broad-spectrum antimicrobial peptide, CST has seen increased recent use as a last resort antibiotic. CST is believed to kill bacteria by virtue of its ability to disrupt membrane integrity (5). This antibiotic requires intravenous administration and is nephrotoxic (6). The emergence of CST-resistant pathogens has also become a significant problem (7). We are unaware of any new broad-spectrum AMPs that have advanced to clinical trials.Imidazolium (IM) salts are antimicrobials (8), and there is an emerging literature on antimicrobial activity of side-chain and main-chain polyimidazolium (PIM) salts with chemical structures that are in some ways similar to those we describe. Although PIMs are potent antimicrobials, there are biocompatibility problems hindering their development, and some have somewhat limited activity spectra. As with other AMPs, there have been toxicity issues, potency issues, and delivery issues as many have large molecular masses, and there is little known about mammalian cell toxicity or mechanism of action (9–12).Here we show that members of a series of PIMs we designed and synthesized are potent broad-spectrum antibacterial compounds. We selected two for further analysis and showed they retain activity even against pan-antibiotic-resistant bacteria. Unlike CST and many other AMPs, which disrupt bacterial membranes, our model PIM is bactericidal without disrupting bacterial membranes. Our experiments provide insights about mechanism of action, the potential for the emergence of PIM resistance, and indicate PIMs are effective against a model gram-negative and a model gram-positive pathogen in murine infection models.     

双胎输血综合征宫内治疗后供血胎和受血胎预后的比较

[目的]评价双胎输血综合征(TTTS)经不同治疗方式,包括羊水减量术(SA)、双极脐带电凝减胎术(BCC)和胎盘吻合血管激光凝固术(LCPV)后,供血胎和受血胎的临床结局.[方法]回顾性分析2008年1月至2013年12月在我院诊断治疗的双胎输血综合征93例,追踪妊娠结局和新生儿情况,分析比较供血胎和受血胎的临床结局.[结果]不同治疗方式组中严重的TTTS(TTTSⅢ期及以上)所占比例分别是:羊水减量术组50.0％(27/54),脐带电凝减胎术组93.9％(31/33),胎盘吻合血管激光凝固术组83.3％(5/6),P＜0.001,因此,3种治疗方式妊娠结局比较时仅纳入TTTSⅢ期及以上病例.SA组、BCC组和LCPV组双胎总体存活率分别是53.7％、24.2％和60.0％,P=0.002.SA组、BCC组和LCPV组分娩孕周中位数分别是31e(20+3～38+2)、28+5(20+2～38+6)和27+6((23+3～37+4)周,其差异无统计学意义(P=0.204).SA组胎膜早破的发生率是29.6％而BCC组和LCPV组胎膜早破的发生率分别是32.3％和60.0％,P=0.410.LCPV组28周前分娩的比例较SA组和BCC组高(分别是60.0％、18.5％和48.4％;P=0.033).TTTS双胎中受血胎存活率是44.1％(41/93)而供血胎存活率是46.2％(43/93),P=0.768;受血胎神经系统发育迟缓发生率是2.4％(1/41)而供血胎神经系统发育迟缓发生率是11.6％(5/43),其差异无统计学意义(P=0.202).[结论]胎盘吻合血管激光凝固术可提高TTTS的总体存活率;TTTS受血胎和供血胎的预后无明显差异.     

气相色谱法测定比卡鲁胺中7种有机溶剂残留量

摘 要 目的： 建立顶空进样气相色谱法检测比卡鲁胺原料药中7种有机残留溶剂二氯甲烷、正己烷、四氢呋喃、乙醇、乙醚、丙酮和乙酸乙酯的方法。方法: 色谱柱为Agilent DB 624弹性石英毛细管柱（30.0 m×0.25 mm×1.4 μm）;进样口温度：200℃;氢火焰离子化检测器(FID)温度：250℃;柱温：程序升温,初始温度35℃,保持13 min,再以100℃/min的速率升至180℃,维持5 min;载气：氮气;流速：1.2 ml·min^-1。顶空进样,顶空平衡温度：90℃,顶空平衡时间：30 min;进样体积：1.0 ml;以二甲基亚砜为溶解介质,测定比卡鲁胺中7种溶剂的残留量。结果: 各被测溶剂均能良好分离,各溶剂峰面积与浓度均呈良好的线性关系,回收率均较为理想。 结论:该法适用于比卡鲁胺原料药中残留溶剂的测定。     

Prognostic factors for postoperative survival in melanoma patients with bone metastasis

Melanoma can spread to the bone by metastasis and is relevant to a poor outcome. However, because of the rarity of melanoma patients with bone metastasis, the prognostic postoperative survival factors of them have not been elucidated. The aim of this special population-based cohort was to elucidate the prognostic factors associated with postoperative survival. The Surveillance, Epidemiology, and End Results database was used to extract postoperative survival data relating to patients with melanoma and bone metastasis at diagnosis between 2010 and 2016, along with data on a range of potential postoperative prognostic factors. We then investigated the potential postoperative prognostic roles of these factors using a Cox regression model and the Kaplan-Meier analysis. In all, the Surveillance, Epidemiology, and End Results database included 186 cases. Regarding overall survival, the 1-, 3-, and 5-year overall survival rates for the entire cohort were 36.2%, 15.4%, and 9.5%, respectively. Regarding cancer-specific survival, the 1-, 3-, and 5-year cancer-specific survival rates were 42.0%, 23.2%, and 16.6%, respectively. Within a cohort of melanoma patients with bone metastasis after surgery, our analysis showed that a smaller tumor size and the lack of metastases at other sites were predictors of survival.     

远志对锰中毒小鼠海马区CaMKⅡ表达的影响

目的:探讨远志对锰中毒小鼠学习记忆和海马CaMKII表达的影响。方法:将60只雌性昆明小鼠随机分为对照组(CG),锰中毒组(MG),锰中毒加远志低剂量组(MLG),锰中毒加远志中剂量组(MMG),锰中毒加远志高剂量组(MHG)。氯化锰(15 mg/kg)采用腹腔注射方式,远志干预(2.5,5,10 g/kg)采用灌胃给药。实验后,动物用Morris水迷宫检测其空间学习和记忆成绩。用免疫组织化学的方法检测海马齿状回区(DG)Ca MKII的表达。结果:在水迷宫的定位航行实验中,各组小鼠的逃避潜伏期与锰中毒组相比,对照组平均逃避潜伏期明显降低(P0.01),远志干预低、中、高剂量组平均逃避潜伏期明显降低(P0.01);在空间探索实验中,与锰中毒组相比,对照组穿越平台次数明显增高(P0.01),远志干预低、中、高剂量组穿越平台次数明显增加(P0.01)。免疫组织化学分析,与对照组相比,锰中毒组DG区Ca MKII表达明显下降,(P0.01),而远志干预低、中、高剂量组海马内CaMKII表达比锰中毒组明显增高(P0.01)。结论:锰中毒小鼠海马齿状回Ca MKII的表达下降,药物远志能够改善锰中毒小鼠学习记忆能力的机制可能与CaMKII的表达增加有关。     

HIV Prevalence and Correlates of Unprotected Anal Intercourse Among Men Who Have Sex with Men, Jinan, China

China’s HIV epidemic may be shifting towards predominantly sexual transmission and emerging data point to potential increases in HIV prevalence among men who have sex with men (MSM). There is particular need to assess the extent of risk behavior among MSM outside of China’s most cosmopolitan cities. We conducted a respondent-driven sampling survey (N = 428) to measure HIV seroprevalence and risk behavior among MSM in Jinan, China, the provincial capital of Shandong. HIV prevalence was 0.5% (95% confidence interval [CI] 0.1–1.0). Unprotected anal intercourse (UAI) in the last 6 months (reported by 61.4%) was associated with buying or selling sex to a man in the last 6 months, syphilis infection, multiple partners in the last month, low HIV knowledge and migrant status. No participant had previously tested for HIV. Risk for HIV transmission is widespread among MSM throughout China; basic prevention programs are urgently needed.     

Research into the reaction process and the effect of reaction conditions on the simultaneous removal of H2S,COS and CS2 at low temperature

In this work, tobacco stem active carbon (TSAC) catalysts loaded on to CuO and Fe₂O₃ were prepared by a sol–gel method and used for the simultaneous removal of hydrogen sulfide (H₂S), carbonyl sulfide (COS) and carbon disulfide (CS₂). The influences of the operating conditions such as reaction temperature, relative humidity (RH), O₂ concentration, and gas hourly space velocity (GHSV) were discussed. DRIFTS results showed that the deactivation was attributed to the generation of S and sulfates. H₂O promoted the generation of sulfate. The enhancement of the hydrolysis of COS/CS₂ was due to the promotion of H₂S oxidation by O₂. A high GHSV decreased the contact time between the gases and the catalyst. Meanwhile, a high GHSV was not conducive to the adsorption of gases on the surface of the catalyst. XPS results indicated that the deactivation of the catalyst was attributable to the formation of S containing components, such as thiol/thioether, S, –SO– and sulfate. BET results indicated that the adsorptive ability of the catalyst was related to the microporous volume and surface area.

The removal processes of COS, CS₂ and H₂S could be divided into two parts: a catalytic hydrolysis reaction and a catalytic oxidation reaction.