The immunomodulating action of cyclosporin A in vitro and in vivo on the lymphocytes of patients with alveolitis

The effect of various concentrations of ofloxacin, ciprofloxacin and lomefloxacin on the morphokinetic parameters of the cellular elements of the lung tissue of intact animals (mice, guinea pigs and dogs) was studied under the conditions of the tissue culture. It was shown that in a concentration of 100 micrograms/ml and the exposure time of 24 hours the drugs had no effect on the mobility and structure of the lung tissue cellular elements. When the drugs were used in a concentration of 100 micrograms/ml the mobility rate of the lymphocytes and macrophages proved to by markedly retarded by the end of the 24th hour. In a concentration of 1000 micrograms/ml the drugs killed the cell culture. There were detected no specific differences in the effect of the fluoroquinolones on the cellular elements of the lung tissue of the intact animals.     

The modulation of cellular responses to poly(2-hydroxyethyl methacrylate) hydrogel surfaces: phosphorylation decreases macrophage collagenase production in vitro

We examined the regulation of collagenase production by the monocyte/macrophage THP-1 cell line when these cells were exposed to poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogel surfaces with different chemistries and morphologies. Tissue culture modified polystyrene (TCP), used as a control surface, induced the maximum collagenase response. Copolymer hydrogels containing 2-ethoxyethyl methacrylate (EMA) or methyl methacrylate (MMA) also induced a high response, while PHEMA hydrogels induced a low level response and the phosphorylated hydrogel induced no response. This pattern was altered when the morphology of the hydrogels was changed to that of a sponge. The overall enzyme response to the sponge hydrogels was lower than that to the homogeneous hydrogels. Sponges containing EMA and MMA produced low level response relative to the TCP control. PHEMA and phosphorylated sponges produced little and no response respectively. The dramatically reduced enzyme response to phosphorylated surfaces was not a consequence of cell death, and may be a phenomenon related to changes in cell surface charge.     

Use of the method of mixed substrates to study the specificity of tRNA methylases

The absence of summation of the rate of methylation of positionally analogous cytidine residues in tRNA1Val, tRNAPhe, and tRNAMet in the case of simultaneous presence of two substrates in the incubation mixture was demonstrated by the method of mixed substrates. The same result was also obtained in the methylation of A19 (counting from the 3' end of the molecule) in tRNA1Val, tRNAPhe, tRNAfMet, tRNASer, and tRNAGlu individually and in the case of their mixing in pairs. These data are evidence that positionally analogous nucleotides in different RNAs are attacked by the same enzyme. Yeast tRNASer, already possessing a methyl group at the cytidine residue studied, proved to be an effective inhibitor of methylase, forming m5C with valine and phenylalanine tRNAs. The results obtained are evidence that differences in the primary and secondary structures at the site of methylation are not the deciding factors in the interaction of tRNA with methylases.     

下一代通信技术对广播电视业务发展的影响(下)

(接上期第43页) 3 下一代通信接入对广播电视业务发展的影响 3.1 突破用户接入的瓶颈 随着宽带业务的发展,网络接入部分(最后1 km)的带宽瓶颈问题显露出来.目前,接入部分两侧都已跨入吉比特级以上的速率,如用户端广泛使用的PC,其内部传送速率已达到32 Gb/s,城域网或长途网的每波长速率也已达到2.5～10 Gb/s,两者都比接入部分高出至少3个数量级.可见,尽快打通接入部分的带宽瓶颈,各种宽带服务与应用才能开展起来,网络容量的潜力才能真正发挥.     

Larvicidal activity of green synthesized silver nanoparticles using Excoecaria agallocha L. (Euphorbiaceae) leaf extract against Aedes aegypti

Green synthesis of silver nanoparticles (AgNPs) using plant extracts has been achieved by eco‐friendly reducing and capping agents. The present study was conducted to evaluate the larvicidal efficacies of AgNPs synthesized using aqueous leaf extracts of Excoecaria agallocha against dengue vector, Aedes aegypti. The 3^rd and 4^th instar larvae of A. aegypti were exposed to various concentrations of aqueous extracts of E. agallocha, synthesized AgNPs and also crude solvent extracts (methanol and chloroform) for 24 h. The formation of AgNPs using aqueous leaf extracts was observed after 30 min with a characteristic colour change. The results recorded from UV‐Vis spectrum, XRD, FTIR, EDX, SEM and HR‐TEM were used to characterize and confirm the biosynthesis of AgNPs. The highest larvicidal efficacy of synthesized AgNPs was observed against 3^rd instar larvae at LC₅₀ 4.65 mg/L, LC₉₀ 14.17 mg/L and 4^th instar larvae with a concentration of LC₅₀ 6.10 mg/L, LC₉₀ 15.64 mg/L. A significant larvicidal activity was also observed with crude methanolic extracts against 3^rd instar larvae at a concentration LC₅₀ 41.74 mg/L, LC₉₀ 123.61 mg/L and 4^th instar larvae at a concentration of LC₅₀ 52.06 mg/L, LC₉₀ 166.40 mg/L as compared to the chloroform extract.Inspec keywords: silver, nanoparticles, nanofabrication, microorganisms, cellular biophysics, organic compounds, ultraviolet spectra, visible spectra, X‐ray diffraction, Fourier transform infrared spectra, X‐ray chemical analysis, scanning electron microscopy, transmission electron microscopyOther keywords: larvicidal activity, green synthesised silver nanoparticles, Excoecaria agallocha L. leaf extract, Aedes aegypti, plant extracts, capping agents, larvicidal efficacies, aqueous leaf extracts, excoecaria agallocha, dengue vector, Aedes aegypti, aegypti, aqueous extraction, E. agallocha, crude solvent extracts, methanol, chloroform, characteristic colour change, ultraviolet‐visible spectrum, X‐ray diffraction, Fourier‐transform infrared spectroscopy, EDX, scanning electron microscopy, high‐resolution transmission electron microscopy, AgNP biosynthesis, larvicidal efficacy, third instar larvae, instar larvae, crude methanolic extracts, chloroform extraction, time 24 h     

Acidic urine pH is associated with elevated levels of free urinary benzidine and N-acetylbenzidine and urothelial cell DNA adducts in exposed workers

We evaluated the influence of urine pH on the proportion of urinary benzidine (BZ) and N-acetylbenzidine present in the free, unconjugated state and on exfoliated urothelial cell DNA adduct levels in 32 workers exposed to BZ in India. Postworkshift urine pH was inversely correlated with the proportions of BZ (r = -0.78; P < 0.0001) and N-acetylbenzidine (r = -0.67; P < 0.0001) present as free compounds. Furthermore, the average of each subject's pre- and postworkshift urine pH was negatively associated with the predominant urothelial DNA adduct (P = 0.0037, adjusted for urinary BZ and metabolites), which has been shown to cochromatograph with a N-(3'-phosphodeoxyguanosin-8-yl)-N'-acetylbenzidine adduct standard. Controlling for internal dose, individuals with urine pH < 6 had 10-fold higher DNA adduct levels compared to subjects with urine pH > or = 7. As reported previously, polymorphisms in NAT1, NAT2, and GSTM1 had no impact on DNA adduct levels. This is the first study to demonstrate that urine pH has a strong influence on the presence of free urinary aromatic amine compounds and on urothelial cell DNA adduct levels in exposed humans. Because there is evidence that acidic urine has a similar influence on aromatic amines derived from cigarette smoke, urine pH, which is influenced by diet, may be an important susceptibility factor for bladder cancer caused by tobacco in the general population.     

Antibody responses of cows during an outbreak of neosporosis evaluated by indirect fluorescent antibody test and different enzyme-linked immunosorbent assays

Hairpin ribozymes with high cleavage activities were designed. An extra sequence was introduced at the 3'-end of the hairpin ribozyme to increase the binding to the substrate RNA, as compared to the wild-type hairpin ribozyme. A three-way junction (TWJ) was formed between the newly designed ribozyme and the substrate RNA. The complex with a solid TWJ showed less RNA cleavage activity than the wild-type hairpin ribozyme. However, the ribozyme with a TWJ with five unpaired bases or propandiol phosphate linkers had higher cleavage activity than the parent ribozyme without the TWJ. When a cis-cleavage system, in which the 5'-end of the substrate RNA was conjugated to the 3'-end of the ribozyme, was employed, the complex with the TWJ containing unpaired bases was also cleaved faster than the complex with the solid TWJ. This suggested that these differences in the cleavage activities were derived from the confirmation, and this was proven by nondenaturing gel electrophoresis. The TWJ hairpin ribozyme containing unpaired bases is able to bind strongly with substrate RNAs and to cleave them efficiently. Since the three-way ribozyme presented here is more active than the wild-type ribozyme, this type of ribozyme can serve as a more efficient tool to control RNA activities in vitro and in vivo.     

Relation between the space flight-induced frequency of dominant lethal mutations and the level of allozyme heterozygosity in Drosophila melanogaster populations

Currently, the treatment of falciparum malaria is seriously compromised by spreading drug resistance. We studied the effects of camptothecin, a potent and specific topoisomerase I inhibitor, on erythrocytic malaria parasites in vitro. In Plasmodium falciparum, camptothecin trapped protein-DNA complexes, inhibited nucleic acid biosynthesis, and was cytotoxic. These results provide proof for the concept that topoisomerase I is a vulnerable target for new antimalarial drug development.     

The French SF-36 Health Survey: translation, cultural adaptation and preliminary psychometric evaluation

This article reports on the main developmental stages and on the preliminary psychometric assessment of the final French version of the SF-36. A standard forward/backward translation procedure was followed. When translating survey items, the emphasis was placed on conceptual equivalence. When translating response choices, we attempted to select a set of response choices that replicate the U.S. version. The distance between the response choices was checked using visual analogue scales (N = 30). The adaptation procedure also included formal ratings of the difficulty of the translation, of the quality of the translation, and of the equivalence between the American source version and the French target version. The face validity was checked during lay panel sessions at which the translated questionnaire was administered to subjects from the general public, hospital employees, and subjects with a low level of education. Standard psychometric techniques were used to evaluate the cultural adaptation of the SF-36, using data from a general population survey. The main objective of this analysis was to determine how well the scaling assumptions (summated rating or Likert-type scaling construction) of the SF-36 were satisfied. The results support the claim that the scaling properties of the French version of the SF-36 are adequate and that health outcomes may be reliably assessed using this version of the instrument.