Deletions and duplication in internal inverted repeat sequence of long region/unique sequence of long region (IRL/UL) of herpes simplex virus type-1 (HSV-1) genome are not evidently associated with intracranial and foot-pad pathogenicity in mouse model

The biological properties of three deletion variants (1704, 1705 and 1706) of herpes simplex virus type-1 (HSV-1) strain 17 syn+, were studied by establishing a base line pathogenicity of nine individual plaques from the parental 17 syn+ elite stock. Restriction enzyme analysis of deoxyribonucleic acid (DNA) from each of the nine plaque stocks and intracranial inoculation into three weeks old BALB/c mice showed no difference in the size of fragments and distribution of the sites or their 50% lethal dose (LD50) values [plaque forming units (pfu)/mouse] as compared to the parental 17 syn+ stock. Inoculation of the variants into three weeks old BALB/c mice showed that 1705 was not different in pathogenicity from the wild type following intracranial and footpad inoculations. On the other hand variants 1704 and 1706, when compared to the wild type virus were less virulent on intracranial inoculation i.e. the difference in LD50 values was approximately one log and two logs respectively and both the variants failed to kill any of the animals following footpad inoculation even at the dose of 1 x 10(7) pfu/mouse. During in vivo replication experiment in the peripheral nervous system of mice, 1704 and 1706 grew very poorly.     

RAG1 mediates signal sequence recognition and recruitment of RAG2 in V(D)J recombination

Recent studies have demonstrated that DNA cleavage during V(D)J recombination is mediated by the RAG1 and RAG2 proteins. These proteins must therefore bind to the recombination signals, but the specific binding interaction has been difficult to study in vitro. Here, we use an in vivo one-hybrid DNA binding assay to demonstrate that RAG1, in the absence of RAG2, can mediate signal recognition via the nonamer, with the heptamer acting to enhance its binding. A region of RAG1 with sequence similarity to bacterial invertases is essential for DNA binding. Localization of RAG2 to the signal is dependent upon the presence of RAG1 and is substantially more efficient with a 12 bp spacer signal than with a 23 bp spacer signal.     

Convergent beam electron diffraction analysis of theT 1 (Al2CuLi) phase in Al-Li-Cu alloys

Point and space group analysis of largeT ₁ (Al₂CuLi) crystals was performed by convergent beam electron diffraction. The structure ofT ₁ was determined to be hexagonal, possessing a 6/mmm point group and P6/mmm (No. 191) space group. The lattice constants were found to bea ≈ 0.497 nm andc ≈ 0.93 nm. This structure is in agreement with an existing model of T₁, although discrepancies between the observed and calculated intensities of certain reflections were evident. Electron probe X-ray microanalysis of theseT ₁ crystals indicates the composition is on the copper-rich side of stoichiometric Al₂CuLi. The slight deviation in the composition ofT ₁ from stoichiometry and the presence of planar defects in the microstructure may account for the discrepancy in the intensity of certain reflections.     

4-(2-吡啶偶氮)间苯二酚固相萃取分光光度法测定痕量铂

研究了4-(2-吡啶偶氮)间苯二酚与铂(Ⅳ)的显色反应,建立了一个测定铂的光度分析新方法。在pH5.0的醋酸-醋酸钠缓冲介质中,溴化十六烷基三甲基铵(CTMAB)存在下,4-(2-吡啶偶氮)间苯二酚与铂(Ⅳ)反应生成摩尔比为2∶1稳定络合物,该络合物可用阳离子交换树脂固相萃取柱富集,吸附柱上富集的络合物用乙醇洗脱后用分光光度法测定。分离后的测定液中,络合物最大吸收波长为490nm,表观摩尔吸光系数ε=1.22×105L·mol-1·cm-1,铂(Ⅳ)含量在0～1.6μg/mL内符合比尔定律,相关系数r=0.9978,对30余种共存离子进行试验,结果表明,大多数常见离子不干扰测定。方法用于合金、矿石、粉煤灰等样品中铂的分析,相对标准偏差小于5.1%,加标回收率在96%～105%之间。     

Synthesis and biological investigations of 1-(tetrahydropyran-2'-yl)- and 1-(tetrahydrofuran-2'-yl)benzimidazoles and 1/2-(tetrahydropyran-2'-yl)- and 1/2-(tetrahydrofuran-2'-yl)benzotriazoles

Sets of benzimidazole and benzotriazole derivatives bearing on position 1 or 2 a tetrahydrofuranyl or tetrahydropyranyl moieties were prepared through the addition of the suitable benzazoles on 2,3-dihydrofuran and 3,4-dihydro-2H-pyran. The reactions were carried on either without solvent or in carbon tetrachloride solution. In the last case some peculiar chlorinated side products were isolated and characterized. Twenty compounds were screened for in vitro antitumoral and anti-HIV-1 activities and found poorly active or completely inactive. On the other hand several compounds exhibited good tracheal relaxant activity in vitro; compound 8, 11, 16, 24 and 26 resulted more active than theophylline in this test, while compound 11 was comparable to amrinone till the concentration of 3 micrograms/ml. Finally, compound 5 resulted endowed with a strong diuretic and saluretic activity at the dose of 3 mg/Kg, thus representing a new lead for discovering new diuretic agents.