Currently, all the conventional antibiotics have developed corresponding drug-resistant pathogenic strains, which have increasingly become a serious threat to people's health. Development of completely new types of antibiotics is one of effective ways to solve the drug resistance issue. Antimicrobial peptides with broad-spectrum antibacterial and antimicrobial activity and wild variety become the ideal alternative to traditional antibiotics. Antimicrobial peptides are derived from wide range of sources, such as plants, animals, and microorganisms. Mechanism of function of the antimicrobial peptides and the investigation approaches of different antimicrobial peptides also vary dramatically. In this paper, we give an overview of preparation, antibacterial mechanisms, and research methodology of antimicrobial peptides.
Lipopolysaccharide (LPS), the important component of the outer membrane of Gram-negative bacteria, contributes to the integrity of the outer membrane, and protects the cell against bactericidal agents. LPS, also called endotoxin synonymously, is well known as a potent inducer of the innate immune system that often causes septic shock in the intensive cares. Chemically, the amphiphilic LPS is made up of three parts, i.e. hydrophobic lipid A, hydrophilic core oligosaccharide chain, and hydrophilic O-antigenic polysaccharide side chain. Specially, the lipid A is known to be responsible for a variety of biological effects during Gram-negative sepsis. LPS can elicit a strong response from innate immune system and result in local or systemic adverse reactions. LPS can trigger massive inflammatory responses and may result in immunopathology, for which the molecular basis is mediated by the signal pathway of LPS. In recent years, a tremendous progress has been made in determining the associated proteins and receptors in the LPS signaling that leads to the disease. This review gives a summary of recent progresses of research on LPS and LPS receptors.
ObjectiveTo explore changes on Electroencephalograph (EEG) and Evoked Potential (EP) changes in autoimmune encephalitis.MethodsEight cases with autoimmune encephalitis from Sichuan people's hospital during July 18th 2014 to July 18th 2016 were recruited. The inclusion criteria included:① The blood and cerebral spinal fluid (CSF) of patients were sent to Neurology Lab of Peking Union Medical College Hospital for autoimmunerelated antibody analysis and confirmed as autoimmune encephalitis.2 Patient had done at least 2 or more times of routine EEG or video EEG (VEEG). 1 or more times of auditory brainstem response (ABR), Visual evoked potential (VEP) and Somatosensory evoked potential (SEP) for both upper and lower limbs. 3 Patients had classical clinical manifestation of autoimmune encephalitis as abnormal psychomotor behaviors, seizures, memory loss, fever, headache, and even disturbance of consciousness or decreased ventilate function.ResulstOf 8 patients in this study, 5 were anti NMDA-R encephalitis, 2 were anti GABABR encephalitis, and 1 was positive for both antibodies. The EEG profile of 5 anti NMDA-R encephalitis:2 of them had β wave in early stage (about 10th day) and δ wave with fast wave even appeared as δ brush in middle stage (about 20th day). They all had severe symptoms and long hospitalization but negative MRI. Another 2 of them could be seen sparsely distributed sharp wave and sharp-slow wave in their EEG. Their EEG gradually turned to normal when their symptoms gradually disappeared. The last one had normal EEG during the whole disease course. The EEG profile of anti GABAB-R encephalitis as following. 1 was dominant by slow wave and EEG went normal after effective treatment and the other showed generalized α wave especially α wave in frontal region. The latter patient withdraw treatment. For the only 1 both antibodies positive patient, EEG showed slow wave and it turned to normal when symptoms disappeared. EP showed some abnormalities with wave amplitude and latency changes in some patients.EP (SEP、VEP) turned to normal when symptoms disappeared.ConclusionThe EEG present differently in different types of autoimmune encephalitis and change with stages of disease. EEG may be used as an indicator for prognosis as well. When EEG shows fast wave with the history of patient points to encephalitis, blood and CSF antibodies for NMDA-R should be checked routinely. Generalized α wave on EEG should also be an indicator for checking GABAB-R. More researches should be done for EP changes in autoimmune encephalitis for our study was based on a small patient number.
ObjectivesTo evaluate the efficacy and safety of lacosamide (200mg/d and 400mg/d)when added to 1 to 3 antiepileptic drugs (AEDs) in adults with uncontrolled partial-onset seizures. MethodsDuring this multicenter, double-blind, placebo-controlled trial, patients were randomized to placebo or lacosamide 200 or 400mg/day after an 8-week baseline period. Lacosamide was titrated in weekly increments to target dose over 4 weeks and maintained for 12 weeks followed by 12 weeks for withdrawal. The reductions of seizure frequence during maintain period and proportion of ≥50% reduction of seizures frequence were analysed. Besides,adverse effects were also recorded. ResultsFive hundred fourty patients were randomized, 515 patients completed the trial (Full analysis set, FAS), including 394 were per-protocol set (PPS). The reduction of seizure frequence during maintain period every 4 weeks among 200mg/d,400mg/d group and placebo group were 26.35%,40.12%,21.69%(P=0.000 5) and 25.61%,46.86%,23.06%(P<0.000 1), respectively in FAS and PPS. The proportion of ≥50% reduction of seizures frequence among three groups were 29.82%,38.15%,22.49%(P=0.006 8) and 27.94%,42.37%,22.86%(P=0.002 3), respectively in FAS and PPS. The incidences of adverse events were 5.84%, 36.11%, 19.55% among three groups. Compared with each other, there was statistic significance between 400mg/d and placebo groups. ConclusionIn this trial, adjunctive lacosamide significantly reduced seizure frequency in patients with uncontrolled partial-onset seizures. Along with favorable pharmacokinetic and tolerability profiles, these results support further development of lacosamide as an AED.