Lipid binding activity of a neuron-specific protein NAP-22 studied in vivo and in vitro

There exists a microdomain called "raft" in the cell membrane. The enrichment of cholesterol and sphingolipids in its outer leaflet is well recognized. In contrast, little is known of the lipid composition of the inner leaflet of raft, where many acylated signal-transducing molecules, such as trimeric G proteins and protein tyrosine kinases, associate. NAP-22 is a neuronal protein localized on the inner leaflet of raft domain. This protein was found to bind cholesterol in the liposome. In this study, we further analyze the lipid binding activity of NAP-22 using eukaryotic and bacterial expression systems. In addition to cholesterol, NAP-22 showed a phosphatidylethanolamine (PE)- and polyphosphoinositide-dependent membrane binding in the liposome assay. The N-terminal myristoylation was essential for the liposome binding. The C-terminal deletion up to D61 showed little effect on the binding. The lipid binding region was hence judged to be in the N-terminal 60-amino-acid sequence. NAP-22 was then expressed in COS7 cells, and the intracellular localization was studied. Biochemical analysis showed the localization of NAP-22 in a Triton-insoluble low-density fraction. Cell staining analysis showed colocalization patterns of NAP-22 with PE and cholesterol in the membrane.     

The neuropeptide NAP provides neuroprotection against retinal ganglion cell damage after retinal ischemia and optic nerve crush

Background  NAP, an 8-amino acid peptide (NAPVSIPQ=Asn-Ala-Pro-Val-Ser-Ile-Pro-Gln) derived from activity-dependent neuroprotective protein (ADNP), plays an important role in neuronal differentiation and the survival of neurons in different pathological situations. We already discovered that NAP increases the survival of retinal ganglion cells (RGC) in vitro, and supports neurite outgrowth in retinal explants at femtomolar concentrations. The aim of this study was to investigate the effects of NAP on RGC survival after transient retinal ischemia and optic nerve crush. Methods  RGC of male Wistar rats were labelled retrogradely with 6 l FluoroGold injected stereotactically into both superior colliculi. Seven days later, retinal ischemia was induced by elevating the intraocular pressure to 120 mm Hg for 60 minutes or by crushing one optic nerve for 10 s after a partial orbitotomy. NAP was either injected intraperitoneally in the concentration of 100 mg/kg 1 day before, directly after, and on the first and the second days after damage, or intravitreally (0.05 or 0.5 μg/eye) directly after the optic nerve crush. Controls received the same concentrations of a control peptide. Densities of surviving RGC and activated microglial cells (AMC) were quantified in a masked fashion 10 days after damage by counting FluoroGold-labelled cells. Results  After retinal ischemia, intraperitoneal injections of NAP increased the number of surviving RGC by 40% (p < 0.005) compared to the control group. After optic nerve crush, NAP raised the number of surviving RGC by 31% (p = 0.07) when injected intraperitoneally and by 54% (p < 0.05) when administered intravitreally. Conclusions  NAP acts neuroprotectively in vivo after retinal ischemia and optic nerve crush, and may have potential in treating optic nerve diseases. Supported by the Ernst und Berta Grimmke Stiftung, Germany. IG is the incumbent of the Lily and Avraham Gildor Chair for the Investigation of Growth Factors and the Director of the Adams Super Center for Brain Research at Tel Aviv University and is the Chief Scientific Officer of Allon Therapeutics Inc., Vancouver, Canada. An erratum to this article can be found at     

Application of chiral derivatizing agents in the high-performance liquid chromatographic separation of amino acid enantiomers: a review

The past 20 years has seen an explosive growth in the field of chirality, as illustrated by the rapid progress in the various facets of this intriguing field. The impetus for advances in chiral separation has been highest in the past decade and this still continues to be an area of high focus. This paper reviews indirect separation approaches, i.e. derivatization reactions aimed at creating the basis for the chromatographic resolution of biologically and pharmaceutically important enantiomers, with emphasis on the literature published in the last 12 years. The main aspects of the chiral derivatization of amino acids are discussed, i.e. derivatization on the amino group, transforming the molecules into covalently bonded diastereomeric derivatives through the use of homochiral derivatizing agents. The diastereomers formed (amides, urethanes, urea, thiourea derivatives, etc.) can be separated on achiral stationary phases. The applications are considered, and in some cases different derivatizing agents for the resolution of complex mixtures of proteinogenic d,l-amino acids, non-proteinogenic amino acids and peptides/amino acids from peptide syntheses or microorganisms are compared.     

探讨预固定对中性粒细胞碱性磷酸酶染色结果的影响

目的探讨预固定对中性粒细胞碱性磷酸酶(NAP)的阳性率和积分产生的影响。方法随机抽取182例来某自三甲综合医院血液科住院患者的新鲜静脉血,乙二胺四乙酸二钾(EDTA-K2)真空管抗凝,制备3份血涂片,第1份(A)在1h内进行NAP染色,第2份(B)预先进行固定,1d后进行NAP染色,第3份(C)不做任何处理,1d后进行NAP染色;同时在其做骨穿时取其新鲜末梢血,制备血涂片,在1h内进行NAP染色;将上述血涂片用NAP染色液进行NAP细胞组化染色,用显微镜在油镜视野下观察100个中性杆状、分叶核粒细胞,以阳性率和积分记录其检测结果。结果 EDTA-K2抗凝静脉血涂片A的NAP阳性率和积分与新鲜末梢血相比差异无统计学意义(P0.05);EDTA-K2抗凝静脉血涂片B的NAP阳性率和积分与新鲜末梢血相比略低,但差异仍无统计学意义(P0.05);EDTA-K2抗凝静脉血涂片C的NAP阳性率和积分与新鲜末梢血相比差异有统计学意义(P0.05)。结论经过预固定的EDTA-K2抗凝静脉血涂片放置1d后,其NAP染色的结果依然可靠,不经过固定的EDTA-K2抗凝静脉血涂片放置1d后,其NAP染色的结果显著降低。     

肝细胞肝癌内NAP1L1的表达及其临床意义

目的 探讨肝癌组织中核小体组装蛋白1-like-1(NAP1 L1)的表达情况.方法 应用免疫组化法检测173例肝癌及癌旁肝组织中NAP1 L1的表达情况.结果 NAP1L1蛋白在癌旁肝组织中不表达,而在肝癌组织中高表达且表达阳性率为28.32％(49/173),且NAP1 L1表达上调与肝硬化、AFP水平显著相关.结论 NAP1 L1在肝癌组织中高表达提示着患者的不良预后,表明NAP1L1在肝癌的发生、发展中可能起着一定的作用.     

Peri-operative cardiac arrest: epidemiology and clinical features of patients analysed in the 7th National Audit Project of the Royal College of Anaesthetists

The 7th National Audit Project of the Royal College of Anaesthetists studied peri-operative cardiac arrest in the UK, a topic of importance to patients, anaesthetists and surgeons. Here we report the results of the 12-month registry, from 16 June 2021 to 15 June 2022, focusing on epidemiology and clinical features. We reviewed 881 cases of peri-operative cardiac arrest, giving an incidence of 3 in 10,000 anaesthetics (95%CI 3.0–3.5 per 10,000). Incidence varied with patient and surgical factors. Compared with denominator survey activity, patients with cardiac arrest: included more males (56% vs. 42%); were older (median (IQR) age 60.5 (40.5–80.5) vs. 50.5 (30.5–70.5) y), although the age distribution was bimodal, with infants and patients aged > 66 y overrepresented; and were notably more comorbid (73% ASA physical status 3–5 vs. 27% ASA physical status 1–2). The surgical case-mix included more weekend (14% vs. 11%), out-of-hours (19% vs. 10%), non-elective (65% vs. 30%) and major/complex cases (60% vs. 28%). Cardiac arrest was most prevalent in orthopaedic trauma (12%), lower gastrointestinal surgery (10%), cardiac surgery (9%), vascular surgery (8%) and interventional cardiology (6%). Specialities with the highest proportion of cases relative to denominator activity were: cardiac surgery (9% vs. 1%); cardiology (8% vs. 1%); and vascular surgery (8% vs. 2%). The most common causes of cardiac arrest were: major haemorrhage (17%); bradyarrhythmia (9%); and cardiac ischaemia (7%). Patient factors were judged a key cause of cardiac arrest in 82% of cases, anaesthesia in 40% and surgery in 35%.     

2-Naphthol levels and genotoxicity in rubber workers

Urinary bladder cancer is a historical disease of rubber workers often been associated with exposure to aromatic amines such as 2-naphthylamine. While exposure to these compounds has decreased markedly over time, the bladder cancer risk has not decreased in direct proportion. Polycyclic aromatic compounds (PAC) are candidates for urinary bladder cancer causation. We determined pre- and post-exposure urinary levels of 2-napthol (2NAP), the major metabolite of a model volatile PAC, in a group of non-smoking rubber workers. Pre- and post-exposure urine samples were collected from 43 non-smoking workers. Overall mean post-shift 2-naphthol levels were increased (13.95 ± 28.4 μg/l), but non-significantly compared to samples collected pre-exposure (7.97 ± 22.1 μg/l; p=0.29). The greatest difference was observed in the curing department where post-exposure samples were 4.5 fold higher, post shift samples were significantly higher in production workers as compared to non-production workers (p=0.02). Levels of 2NAP were not correlated with levels of carcinogen-DNA adducts in exfoliated urothelial cells nor with other estimates of exposure or effect. These data suggest that post-shift urinary 2NAP levels are increased, particularly in the curing department. However, the differences were not significantly different overall and urinary 2NAP levels did not predict the level of carcinogen DNA adducts in exfoliated urothelial cells.     

联合检测CRP、NAP、WBC、NC在门诊发热病人鉴别诊断中的意义

目的:探讨门诊发热病人联合检测C-反应蛋白(CRP)、中性粒细胞碱性磷酸酶(NAP)、白细胞(WBC)、中性粒细胞分类(NC)的意义与价值.方法:分别检测细菌感染组(54例)患者、非细菌感染组(62例)患者和健康对照者(48例)的血CRP、NAP、WBC和NC.结果:细菌感染组各指标检测结果均明显高于非细菌感染组和健康对照组(P＜0.01);细菌感染组患者CRP阳性率明显高于NAP、WBC和NC的阳性率(P＜0.01).结论:门诊发热病人联合检测CRP、NAP、WBC、NC有助于早期鉴别诊断细菌感染和非细菌感染,尤其是是CRP,阳性率高、快速、敏感.