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Objective To compare the efficacy and safety of tenofovir disoproxil fumarate ( TDF) and entecavir(ETV) in the treatment of chronic hepatitis B(CHB) with positive hepatitis B E antigen(HBeAg). Methods A total of 104 cases with newly diagnosed HBeAg positive CHB were selected and randomly divided into TDF group and ETV group,with 52 cases in each group. The TDF group was given 300mg/d TDF,and the ETV group was given 0. 5mg/d ETV. All the patients were continuously treated for 12 months. The serum HBV DNA, HBeAg and ALT levels before and after treatment were compared between the two groups. Results Before treatment,there were no statistically significant differences in serum HBV DNA,HBeAg and ALT levels between the two groups ( t=0. 12, 1. 51,1. 62,all P＞0. 05). The serum HBV DNA,HBeAg and ALT levels in the two groups were decreased after treatment,and the decrease of serum HBV DNA level in the TDF group was more significant than that in the ETV group,the difference was statistically significant(t =3. 54,P ＜0. 05),but there were no statistically significant differences in serum HBeAg and ALT levels between the two groups(t=0. 04,0. 79,all P＞0. 05). The total effective rate of the TDF group was 92. 31% (48/52),which was significantly higher than 76. 92% (40/52) in the ETV group (χ2=4. 73,P＜0. 05). During treatment,the incidence rate of adverse reaction of the TDF group was 7. 69% (4/52),which was lower than 11. 54% (6/52) of the ETV group,but the difference was not statistically significant (χ2=0. 44,P＞0. 05). Conclusion TDF has better clinical effect in treating newly diagnosed HBeAg positive CHB than ETV due to TDF can inhibit HBV DNA replication significantly,but the safety of TDF and ETV is similar.
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Em laboratório de biologia molecular existem normas para prevenir que nucleases destruam os ácidos nucleicos em análise. Rígida adesão a estas normas é primordial, principalmente em laboratórios de análises clínicas e ao se lidar com amostras com número restrito de cópias do genoma-alvo. Em contraposição, diversas nucleases têm tido importância fundamental, por exemplo, na identificação do ácido nucleico de vírus, investigação de RNA mensageiro, purificação de vírus em abordagem metagenômica, edição de genomas com o sistema CRISPR/Cas e descoberta de enzimas. O conhecimento de como nucleases podem ser tanto vilãs quanto aliadas é essencial na formação de todos que trabalham no campo de biologia molecular.
In a molecular biology laboratory there are standards to prevent nucleases from destroying the nucleic acids under analysis. Strict adherence to these standards is paramount, mainly in clinical analysis laboratories and when dealing with samples with a limited number of copies of the target genome. In contrast, several nucleases have been of fundamental importance, for example, in the identification of the type of viral nucleic acid, investigation of messenger RNA, virus purification in metagenomic approach, genome editing with the CRISPR/Cas system, and enzyme discovery. Knowledge of how nucleases can be both villains and allies is essential in the training of all working in the field of molecular biology.
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HBVcccDNA is the first template for HBV to replicate in hepatocytes and the key factor to HBV to continous infect, which can directly reflect HBV′s infections state and replication.The examination of HBVcccDNA is an effective index to evaluate anti-HBV drugs and an objective index to judge wheter HBV infects extrahepatic tissue. cccDNA found in the serum is an important sign of hepatocyte damage at an early stage. There are nested PCR, selective PCR, Southern imprinted hydridization etc.The methods of qualitative detection include real-time PT-PCR, competitive PCR and intruder detection. Currently, there are some deficiencies existing in the clinical method and the examination system of HBVcccDNA has not yet been formed.Further research and exploration are need to be done in order to provide reliable reference for clinical diagnosis and treatment. The level of HBVRNA in serum potentially reflect cccDNA′s existence and transcription in patient′s liver cells.
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In recent years, with the introduction of novel vectors capable of highly efficient transduction ,ribozymes and dexyribozymes have been become an ideal approach to anticancer therapy due to their high efficiency and lack of severe adverse effects. As many high efficiency targets have been found for cancer therapy, targeted therapy using ribozymes and deoxyribozymes may have multiple effects such as induction of tumor apoptosis and inhibition of tumor growth, metastasis, and angiogenesis.
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Objective To investigate the correlation between neuronal injury and the expression of caspase-3 and caspase-activated deoxyribonuclease (CAD) after focal cerebral ischemia-reperfusion in rats, also to study the effect of caspase-3 particular inhibitor. Methods The focal cerebral ischemia model (occluding middle cerebral artery of the rats) was made by using modified inserting thread method and reperfusion after embolizing for one hour. Using HE staining, TUNEL staining and microscopy to observe the morphological changes of ischemic neurons at six different time points including 6,12,24,48 and 72 h, using immunohistochemistry to observe the changes of caspase-3 and CAD protein in two groups (model group and interfere group). Results There was no significant difference between the two groups using HE staining and microscopy. While there was difference of TUNEL staining positive cells in all time points, except 6 h time point; Both the two groups reached the expression peak of caspase-3 in 24 h, and the number was 2. 360± 0. 318 and 0. 804 ± 0. 206 respectively(t' = 10. 039, P < 0. 01), there was statistical significance from 12 h to 48 h between the two groups ; The expression peak time of CAD protein in two groups was 48 h, and the number was 3.061 ± 0. 567 and 0. 812 ± 0. 240 respectively (t' = 8. 960, P < 0. 01), there was statistical significance from 12 to 72 h between two groups. Conclusions Caspase-3-CAD-DNA degradation is one important way of neuronal injury in cerebral ischemia-reperfusion of rats, caspase-3 inhibitor can protect neuron in a certain degree.
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Objective To investigate the expression and secretion of mice DNaseI gene plasmid transfected into bone marrow (BM-MSCs) mesenchymal stem cells. Methods The plasmids of mouse DNaseI gene had been transfected into the BM-MSCs of mice by liposomes. The expression of DNaseI gene in the BM-MSCs was detected by western blotting and the DNaseI activity was measured by DNA-methyl green substrate colorimetry. Results About 30% BM -MSCs were transfected with mice plasmid DNaseI gene, DNaseI was expressed in the transfected BM-MSCs and active DNaseI could be detected in the supernatant of cell culture. Conclusion The mice DNaseI gene plasmid can be transfected into mice BM -MSCs by liposomes and DNaseI gene can be expressed by the transfected BM-MSCs and active DNaseI can be secreted. This may provide potential target for the treatment of SLE.
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Objective:To purify a kind of deoxyribonuclease from earthworm Eisenia foetida (named earthworm DNase, EDNase) and study its characteristics. Methods: Acetone precipitation, ion-exchange chromatography, high performance liquid chromatography, SDS-PAGE, CapiUary electrophoresis isoelectric focusing and MALDI-TOP MS were used for the study. Results: This purified protocol improved 137-fold purification and 45.6 % recovery of enzyme activity. The molecular mass of EDNase was estimated to be 63 000. Mg2+ , Mn2+ and Ca2+ were strong inhibitors of EDNase, while Na+ slightly increasd the enzyme activity. The enzyme was completely stable in the pH range from 4. 4 to 5.2 and had a pH optimum of 4.8. The optimum temperature was 37℃ and the enzyme was stable up to 40 ℃. The pI of the enzyme was 6. 20. Km and Vmax for the enzyme were 1.52 g/L and 4. 89 mg/(mL ·min), respectively, with calf thymus DNA as substrate. The enzyme was able to degrade chromosemal DNA, linear λbacteriophage DNA as well as supereoiled plasmid DNA, but didn' t display any RNase activity. Conclusion: This kind of deoxyribonuclease possesses unique characteristics, which is different from the deoxyribonucleases which we have known before.
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Objective To explore the epidemic conditions of rheumatic fever (RF) with a simple method at some regions.Methods Antistreptococcal DNase B test microtiter method was adopted to detect human sera antibody in natural populations who are responsible to RF.All 216 schoolchildren aged 10～12 years old were chose by the random cluster sampling.The schoolchildren′s serum antibody against DNase B in each season from september 1988 to August 1989 was detected,and compared with antistreptolysin “O” (ASO);furthermore,5 different regional schoolchildren′s serum antibody to DNase B was tested, and 100 schoolchildren aged 10～13 years old were chose in every region.Meanwhile,the RF incidence of 5～18 year schoolchildren was investigated for 4 years,and approximately 364 915 person times were inquired.All the results of the anti DNase B and ASO were compared with the schoolchildren′s RF incidence.Results ① The levels of the anti DNase B were higher during fall,winter and spring seasons,and lower in summer,which were coincided with the RF incidence,and linear relation was very good ( r =0 913, P
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The activities of acid and alkaline deoxyribonucleases in the white and grey matter areas of growing and old chick cerebrum were measured. Two marker enzymes for glial cells, butyrylcholinesterase and carbonic anhydrase were also measured in these regions. Higher specific activities of both butyrylcholinesterase and carbonic anhydrase were found in the white matter region at all the stages studied. Acid and alkaline deoxyribonuclease activities were observed in both white and grey matter. The decrease in the specific activity of acid deoxyribonuclease with advancement of age was more pronounced as compared to the alkaline deoxyribonuclease Marked reduction in total acid deoxyribonuclease activity in white matter, beyond the age of 130 days, was observed. On the other hand, total alkaline deoxyribonuclease activity in both white and grey matter continued to increase with age Further, the activity per mg of DNA also increased in white matter of the old brain. These results indirectly suggest a continued role for alkaline deoxyribonuclease in glial cells formed at a later age.