Nonconvulsive status epilepticus: high incidence in dialysis-dependent patients

Nonconvulsive status epilepticus is defined as a mental status change from baseline of at least a 30-min duration associated with constant or near-continuous ictal discharges on an electroencephalogram (EEG). Nonconvulsive status epilepticus is an often-overlooked diagnosis as a cause of acute confusional state. There are few case reports in dialysis patients. We are reporting 5 patients on chronic dialysis treatment who presented with an acute confusional state. Nonconvulsive status epilepticus was diagnosed by EEG and response to intravenous benzodiazepines. We recommend early EEG to be considered in the evaluation of dialysis patients with an acute confusional state.     

注射用盐酸头孢替安配伍溶液中降解产物的测定

测定注射用盐酸头孢替安与0.9%Na Cl注射液配伍后的降解产物。采用LC-MS,RP-HPLC法,分别以0.02mol·L-1 NH4Ac水溶液-乙腈及磷酸盐缓冲液-乙腈为流动相,对溶液配伍后的降解产物进行定性、定量分析。两个主要降解产物确定为DMMT和去四唑头孢替安内酯;配伍后室温放置8h,DMMT的量增加明显,百分含量由约0.03%增加至约0.15%,去四唑头孢替安内酯的量由约0.1%增加至约0.3%,杂质总量由0.03%增加至约0.15%。注射用盐酸头孢替安与0.9%氯化钠注射液配伍后不稳定,应临用新制,以确保临床用药安全。     

Intermittent hemodialysis treatment in cefepime‐induced neurotoxicity: Case report,pharmacokinetic modeling,and review of the literature

Cefepime is a broad‐spectrum cephalosporin indicated for in‐hospital treatment of severe infections. Acute neurotoxicity, an increasingly recognized adverse effect of this drug in an overdose, predominantly affects patients with reduced renal function. Although dialytic approaches have been advocated to treat this condition, their role in this indication remains unclear. We report the case of an 88‐year‐old female patient with impaired renal function who developed life‐threatening neurologic symptoms during cefepime therapy. She was treated with two intermittent 3‐hour high‐flux, high‐efficiency hemodialysis sessions. Serial pre‐, post‐, and peridialytic (pre‐ and postfilter) serum cefepime concentrations were measured. Pharmacokinetic modeling showed that this dialytic strategy allowed for serum cefepime concentrations to return to the estimated nontoxic range 15 hours earlier than would have been the case without an intervention. The patient made a full clinical recovery over the next 48 hours. We conclude that at least 1 session of intermittent hemodialysis may shorten the time to return to the nontoxic range in severe clinically patent intoxication. It should be considered early in its clinical course pending chemical confirmation, even in frail elderly patients. Careful dosage adjustment and a high index of suspicion are essential in this population.     

毛细管电泳法分析盐酸头孢吡肟中N-甲基吡咯烷含量

建立了一种毛细管电泳间接紫外检测注射用盐酸头孢吡肟中的N-甲基吡咯烷(NMP)含量的方法,讨论了检测波长、电压、进样时间、缓冲溶液的pH值等因素对盐酸头孢吡肟中NMP的影响,获得了优化的分离条件.结果表明,以含0.01 mol/L咪唑和1 mol/L的醋酸(pH=4.7)溶液为背景电解质.在电压为3.00kV,检测波长...     

Short communication: Extended-spectrum AmpC–producing Escherichia coli from milk and feces in dairy farms in Brazil

The AmpC enzyme is normally expressed constitutively in Escherichia coli, and its overproduction confers resistance to cefoxitin. A newly reported AmpC, the extended-spectrum AmpC (ESAC), is related to resistance to cefepime, a fourth-generation cephalosporin. This enzyme presents more flexibility in the active site due to insertions, replacements, and deletions on AA sequences. Many isolates producing ESAC were reported in human clinical isolates, but E. coli ESAC producers were reported in animals only in France. The animal E. coli strains can produce this enzyme and possibly disseminate it to human and production environments. In our study, 3 strains of E. coli from milk and feces bovine samples, collected in Rio de Janeiro, Brazil, were suspected to produce ESAC. After excluding other mechanisms of resistance, the gene was sequenced to verify ESAC characteristics. These strains presented replacement of AA in omega and R2 loops, suggesting ESAC production. This is the first report to study ESAC E. coli in dairy farms in Brazil.     

盐酸头孢吡肟的合成新方法

介绍盐酸头孢吡肟的一种合成新方法。此方法以7-氨基-3-[（1-甲基-1-吡咯烷基）甲基]头孢-3-烯-4-羧酸盐酸盐和2-甲氧亚氨基-2-（2-氨基-4-噻唑基）-（z）-乙酸二乙基磷酰活性酯为起始原料。具有收率高,杂质低,成本低等优点。并利用核磁共振和质谱对产物进行了表征。     

ON-CHIP ELECTROCHEMICAL DETERMINATION OF CEFEPIME

Cefepime is an important fourth-generation cephalosporin, having a broad antimicrobial spectrum. This article describes a new application of microfabricated chip with integrated Pt microelectrodes, for the electrochemical detection (ECD) of cefepime. In this analysis, electro-oxidation of cefepime was investigated on an unmodified Pt microelectrode in acetate buffer at pH 4.5. Differential pulse voltammetry (DPV) along with cyclic voltammetry (CV) was performed as a major read out technique. With this method, a linear calibration curve for 25–150 μM with a limit of detection of 15 μM was obtained. This investigation presents a simple methodology and rapid results that, within the above calibration range, can be obtained without any pretreatment of the analyte.     

7-氨基-3-(1-甲基四氢吡咯)甲基-3-头孢-4-羧酸盐酸盐的合成改进

以7- 氨基-3 - 氯甲基- 3 -头孢烯- 4- 羧酸二苯甲酯盐酸盐(ACLH·HCl)为原料,经过缩合、烷基化及水解,合成了标题化合物。烷基化时革除了碘代反应,并以异丙醇代替四氯化碳作溶剂,简化了操作,提高了安全性;水解去保护基时提高了反应温度,更换溶剂系统,使收率由3 7%提高到83 %。本工艺操作简便,安全,条件温和,产物容易提纯,总收率可由3 4%提高到77 8% ,产物的质量分数大于98%。