用体外免疫法建立人—人抗流行性乙型脑炎病毒杂交瘤细胞株

利用单克隆抗体(McAb)进行病毒病的治疗是人们所关心的一个重大课题。 流行性乙型脑炎(乙脑)是一种严重威胁人民健康的急性传染病,病死率高,后遗症严重。国内外目前尚无特效疗法。陈伯权等用乙脑病毒皮下或腹腔感染3周龄小白鼠24、48小时及5天后,分别用乙脑病毒51-8McAb进行治疗,平均治愈率分别为78％、73％及22％。     

脊髓高位横断诱发大鼠急性胃溃疡机制的研究

在颈七水平横断大鼠脊髓以诱发急性胃溃疡。结果表明:(1)脊髓横断动物的体温随环境温度而下降,体温的下降可能是诱发溃疡的重要原因之一;(2)注射肾上腺素可减轻溃疡和防止体温下降,且两者均呈剂-效关系;(3)切除肾上腺可使脊髓横断诱发的溃疡明显减轻,如补充注射地塞米松则可使之重新加重,但体温的下降在以上情况下均不受影响;(4)脊髓横断后胃粘膜泌酸和内分泌功能的改变可能与溃疡生成有关。     

慢性缺氧对大鼠左右心室功能、心肌肌原纤维Ca~（2＋），Mg~（2＋）－ATP

模拟５０００ｍ中度缺氧时,大鼠右室功能显著加强,而左室功能加强不显著;左右心室肌原纤维Ｃａ２＋,Ｍｇ２＋－ＡＴＰ酶活性下降,肌球蛋白同功酶Ｖ２和Ｖ３百分含量增加,Ｖ１百分含量减少。８０００ｍ重度缺氧时,右室功能减弱,但无统计学意义,左室功能减弱有显著性;ＡＴＰ酶活性和同功酶的变化超过５０００ｍ组。此外,右室ＡＴＰ酶活性与ＰＡＰ呈反比且有显著性,左室ＡＴＰ酶活性与ＣＡＳＰ虽也呈反比但无显著性;右室同功酶Ｖ３百分含量与ＰＡＰ呈正比,左室同功酶Ｖ３百分含量与ＣＡＳＰ不呈比例。上述结果表明,因短期突发严重缺氧引起的心肌供氧不足对左心室心肌的直接损伤作用大于右心室心肌。     

EGF对大鼠卵巢颗粒细胞增殖与分化影响的研究

许多研究发现,表皮生长因子(EGF)对生殖功能有重要的调节作用。本文用体外细胞培养的方法,研究了EGF对大鼠卵巢颗粒细胞增殖与分化的影响及其作用方式。结果如下:EGF可以明显抑制颗粒细胞DNA的合成,但促进孕酮的生成,后者是因为EGF能显著提高细胞内3β-羟甾脱氨酶(3β-HSD)的活性。放射受体分析表明,颗粒细胞上存在EGF的特异性受体,其K_d为1.83±0.3×10~(-8)mol/L,B_(max)为1.75±0.29×10~4个位点/细胞。卵巢免疫组化结果未发现颗粒细胞有EGF样免疫染色,而卵泡膜、黄体及间质内等均有阳性染色。以上结果提示,EGF可能通过旁分泌机制作用于颗粒细胞的EGF受体,从而调节细胞的生长和性激素的分泌,这对于颗粒细胞的成熟及卵泡的发育有着重要意义。     

Accessing the Two‐Electron Charge Storage Capacity of MnO2 in Mild Aqueous Electrolytes

Rechargeable batteries based on MnO₂ cathodes, able to operate in mild aqueous electrolytes, have attracted attention due to their appealing features for the design of low‐cost stationary energy storage devices. However, the charge/discharge mechanism of MnO₂ in such media is still a matter of debate. Here, an in‐depth quantitative spectroelectrochemical analysis of MnO₂ thin‐films provides a set of unrivaled mechanistic insights. A major finding is that charge storage occurs through the reversible two‐electron faradaic conversion of MnO₂ into Mn²⁺ in the presence of a wide range of weak Brønsted acids, including the [Zn(H₂O)₆]²⁺ or [Mn(H₂O)₆]²⁺ complexes present in aqueous Zn/MnO₂ batteries. Furthermore, it is shown that buffered electrolytes loaded with Mn²⁺ are ideal to achieve highly reversible conversion of MnO₂ with both high gravimetric capacity and remarkably stable charging/discharging potentials. In the most favorable case, a record gravimetric capacity of 450 mA·h·g^?1 is obtained at a high rate of 1.6 A·g^?1, with a Coulombic efficiency close to 100% and a MnO₂ utilization of 84%. Overall, the present results challenge the common view on MnO₂ the charge storage mechanism in mild aqueous electrolytes and underline the benefit of buffered electrolytes for high‐performance rechargeable aqueous batteries.     

Design,synthesis and cholinesterase inhibitory properties of new oxazole benzylamine derivatives

Abstract

The enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are primary targets in attenuating the symptoms of neurodegenerative diseases. Their inhibition results in elevated concentrations of the neurotransmitter acetylcholine which supports communication among nerve cells. It was previously shown for trans-4/5-arylethenyloxazole compounds to have moderate AChE and BChE inhibitory properties. A preliminary docking study showed that elongating oxazole molecules and adding a new NH group could make them more prone to bind to the active site of both enzymes. Therefore, new trans-amino-4-/5-arylethenyl-oxazoles were designed and synthesised by the Buchwald-Hartwig amination of a previously synthesised trans-chloro-arylethenyloxazole derivative. Additionally, naphthoxazole benzylamine photoproducts were obtained by efficient photochemical electrocyclization reaction. Novel compounds were tested as inhibitors of both AChE and BChE. All of the compounds exhibited binding preference for BChE over AChE, especially for trans-amino-4-/5-arylethenyl-oxazole derivatives which inhibited BChE potently (IC₅₀ in µM range) and AChE poorly (IC₅₀?100?µM). Therefore, due to the selectivity of all of the tested compounds for binding to BChE, these compounds could be applied for further development of cholinesterase selective inhibitors.

• HIGHLIGHTS

• Series of oxazole benzylamines were designed and synthesised

• The tested compounds showed binding selectivity for BChE

• Naphthoxazoles were more potent AChE inhibitors

     

Polymorphisms in the IL-18 and IL-12B genes and their association with the clinical outcome in Croatian patients with Type 1 diabetes

Genetic variants of IL-18 and IL-12B may be important in immunoregulatory abnormalities, observed in the patients with Type 1 diabetes mellitus (T1DM), that contribute to individual differences in response to a treatment. Therefore, we examined the significance of IL-18-137G/C, IL-18-607C/A, and IL-12B A/C polymorphisms in Croatians (187 patients, 236 controls), not only as factors that contribute to susceptibility to T1DM, but also as determinants of the clinical presentation of disease.     

High-Resolution Plasmonic Filter and Refractive Index Sensor Based on Perturbed Square Cavity with Slits and Orthogonal Feeding Scheme

Plasmonics - We present a plasmonic bandpass filter and refractive index sensor based on perturbed square cavity resonator with slits, which is fed by orthogonally oriented feeding waveguides. The...     

Evaluation of a flat membrane hepatocyte bioreactor for pharmacotoxicological applications: evidence that inhibition of spontaneously produced nitric oxide improves cell functionality

A laboratory-scale bioreactor was re-evaluated, with the aim of improving its use for the perfused culture of rat hepatocytes. In contrast to conventional culture systems, the flat membrane bioreactor (FMB) showed good functionality and biochemical competence during 2-3 days. Hepatocytes cultured in the FMB, specifically in a "sandwich" configuration, were functionally stable, as shown by a high rate of urea biosynthesis after challenge with NH4Cl, a low alanine-aminotransferase leakage and suppressed spontaneous nitric oxide (NO) production. Moreover, the time-course of the disappearance of cyclosporin A (CsA) from the perfusate demonstrated the high biotransformation capacity of cells in the FMB. The effect of CsA on the modulation of urea and spontaneous NO production demonstrated flexibility, in that minor changes could be observed at diverse time intervals and in a non-destructive way. The monitoring of nitrite levels during various steps of isolation and culture suggested that spontaneously produced NO has a negative impact on hepatocyte metabolic and functional integrity. In spite of the sophisticated techniques that are being used for the preparation of bioreactors, with hepatocytes surviving for longer periods, our data have shed light on some factors that could be important for the successful use of similar models for pharmacotoxicological and other biomedical applications.     

RecFOR function is required for DNA repair and recombination in a RecA loading-deficient recB mutant of Escherichia coli

The RecA loading activity of the RecBCD enzyme, together with its helicase and 5' --> 3' exonuclease activities, is essential for recombination in Escherichia coli. One particular mutant in the nuclease catalytic center of RecB, i.e., recB1080, produces an enzyme that does not have nuclease activity and is unable to load RecA protein onto single-stranded DNA. There are, however, previously published contradictory data on the recombination proficiency of this mutant. In a recF(-) background the recB1080 mutant is recombination deficient, whereas in a recF(+) genetic background it is recombination proficient. A possible explanation for these contrasting phenotypes may be that the RecFOR system promotes RecA-single-strand DNA filament formation and replaces the RecA loading defect of the RecB1080CD enzyme. We tested this hypothesis by using three in vivo assays. We compared the recombination proficiencies of recB1080, recO, recR, and recF single mutants and recB1080 recO, recB1080 recR, and recB1080 recF double mutants. We show that RecFOR functions rescue the repair and recombination deficiency of the recB1080 mutant and that RecA loading is independent of RecFOR in the recB1080 recD double mutant where this activity is provided by the RecB1080C(D(-)) enzyme. According to our results as well as previous data, three essential activities for the initiation of recombination in the recB1080 mutant are provided by different proteins, i.e., helicase activity by RecB1080CD, 5' --> 3' exonuclease by RecJ- and RecA-single-stranded DNA filament formation by RecFOR.