树鼩大肠内容物细菌的群落多样性分析

目的应用高通量测序技术分析树鼩大肠细菌的结构与组成。方法采集3只雄性树鼩大肠内容物,用细菌16Sr DNA通用引物扩增V3~V4区,采用Illumina PE250平台测序。结果共获得160 157条有效序列,聚类后得437个运算分类单位(operational taxonomic units,OTUs)。树鼩大肠中的细菌有9个门、19个纲、37个目、68个科、137个属和194个种。其中,(1)厚壁菌门和变形菌门的丰度最高,分别为63.30%和28.52%;(2)优势纲是芽孢杆菌纲和γ-变形菌纲(51.46%、28.02%);(3)乳杆菌目和肠杆菌目的丰度最高,为45.33%和27.51%;(4)优势科是乳杆菌科(35.30%)和肠杆菌科(27.51%);(5)乳杆菌属和埃希氏菌属为优势属(35.30%、27.49%);(6)在种的水平,可培养细菌的丰度为37.10%,未分类细菌27.69%,不可培养细菌35.21%。可培养细菌中,唾液链球菌的丰度最高(26.66%)。在丰度最高的20个种中,8种细菌(40%)未分类,为以往未被发现的新种。个体间细菌群落存在一定差异。结论树鼩大肠内容物中的细菌组成具有丰富的多样性,其中还有许多未被分类鉴定且相对丰度较高的细菌,需要进一步研究。

大肠埃希氏细菌中ESBLs耐药质粒的传播与消除研究

【目的】研究大肠埃希氏细菌中超广谱β-内酰胺酶(Extended-spectrumβ-lactamases,ESBLs)耐药质粒的传播及氯丙嗪对其的消除效果。【方法】采集河南开封和安阳疑似大肠埃希氏细菌病病死鸡、猪典型病料,经细菌学检验后,用试管二倍稀释法测定头孢噻呋和头孢曲松对致病性大肠埃希氏细菌的最小抑菌浓度(MIC),用双纸片协同法和PCR扩增法进行ESBLs检测。以安阳猪和开封鸡大肠埃希氏细菌作供体菌、DH5α为受体菌,进行ESBLs耐药质粒的接合传递试验。用氯丙嗪作消除剂,以SDS为对照,对大肠埃希氏细菌分离株ESBLs耐药质粒进行消除试验。【结果】从疑似大肠埃希氏细菌典型病料中分离到了大肠埃希氏细菌;头孢噻呋和头孢曲松对分离菌株的最小抑菌浓度分别为32~64和64~128μg/mL;检测到了ESBLs耐药质粒的存在,且其能在大肠埃希氏细菌间传播,氯丙嗪对其第12次的消除率高达98.83%。【结论】ESBLs耐药质粒可通过接合转移方式传递至感受态大肠埃希氏细菌中,氯丙嗪对其消除效果很好。

产ESBL大肠埃希菌质粒谱与耐药性分析

目的：探讨产超广谱β-内酰胺酶（ESBL）大肠埃希菌质粒谱与耐药性的关系.方法：收集产ESBL大肠埃希菌100株,采用质粒提取试剂盒小量抽提质粒,琼脂糖凝胶电泳观察质粒条带,采用E-test试验检测最小抑菌浓度（MIC）,结果按照美国临床与实验室标准化协会（CLSI）规定标准执行.结果：所有菌株均含有1～5条质粒条带不等,分子质量大小依次约为21000,9000,7000,3000,2500bp.相同质粒条带菌株的质粒在电泳时条带分布一致.不同质粒条带的菌株均对青霉素类、头孢一、二代及三代中头孢噻肟、头孢曲松耐药（MIC≥256mg/L）,对头孢他啶表现为体外试验敏感（MIC≤4mg/L）,对四代头孢菌素头孢吡肟表现不一（MIC值分别为32,48,48,16,64mg/L）.对阿米卡星、亚胺培南对碳青酶烯类抗菌素稳定敏感（MIC分别为≤12,0.25mg/L）.各组间均P〉0.5/0.9,表明对抗菌药物耐药性无差异.结论：产ESBLs大肠埃希菌质粒谱的类别和数量与耐药性相关性不大.

美利用基因改造细菌抗击艾滋病毒

据医学空间网11月18日报道，美国科学家已成功基因改造存于人体的细菌，以产生化学物质阻止艾滋病毒传播。研究员基因改造其中1种细菌，这种大肠细菌经基因改造后，能分泌出蛋白质阻止艾滋病毒感染其目标细胞。当研究员将这种基因改造细菌放进老鼠体内，细菌成功在肠末繁殖，在阴道亦找到数量较少的细菌。研究员表示有找到防止艾滋病传播方法的迫急需要，特别是发展中国家艾滋病问题严峻。科学家正研究涂于性器官的杀微生物凝胶或乳液，以阻止艾滋病传染。这些杀微生物剂要在进行性爱前涂抹，限制了其使用。

Morphological Changes of Hemocytes of Musca domestica Larva in vitro Infected by Escherichia coli

[Objective] The research aimed to observe the effects of Escherichia coli infection on the morphology of hemocytes of the 3rd stage larva of Musca domestica in vitro and understand the hemocytes types that take part in the cell immunity of Musca domestica larval.[Method] The hemcytes of the 3rd stage larva of Musca domestica were cultured in vitro and the hemocyte morphology was observed about 2,4,6,8 h after culture in vitro.After Escherichia coli were injected into the hemocytes of the 3rd stage larva of Musca domestica in vitro,the morphology changes of hemocytes were observed at different time after infection.[Result] The hemocytes of of the 3rd stage larva of Musca domestica was divided into five types about 2 h after hemoculture.The hemocytes partly adherence was seen about 6 h after hemoculture.The vacuolation and morpholysis was found in plasmatocytes after being infected by E.coli and a great quantity bacterium were gathered around granulocyte,but the morphology changes of hemocytes were not found in the prohemocyte,shprulocyte and oenocytoid.[Conclusion] The plasmatocyte and granulocyte were primary participants of the cell immunity of Musca domestica larval,but the prohemocyte,sphrulocyte and oenocytoid do not participate in the cell immune reactions.

Adhesive Patterns of Escherichia coli F4 in Piglets of Three Breeds

Escherichia coli expressing F4 fimbriae is the major pathogenic bacteria that causes diarrhea in piglets before weaning. The adhesion of E. coli to the brush borders of the epithelial cells of piglets is the precondition leading to diarrhea, which in turn is due to the presence of the F4 receptors determined by an autosomal recessive gene on the brush borders of the epithelial cells. In order to clarify the genetic mechanism of the adhesion, an in vitro adhesion experiment was carded out for three variants of E. coli F4 （ab, ac, and ad） in 366 piglets of three pig breeds [Landrace （LR）, Large White （LW）, and Songliao Black （SB）]. The results showed that there existed significant differences （P〈0.001） in the adhesion percentage among the three breeds. Most SB piglets were nonadhesive for all the three variants, whereas most LR piglets were adhesive. Within each breed except for LR, the proportions of the three F4 variants adhering to the brush borders differed significantly. According to the patterns of the adhesion of the three F4 variants in the three breeds, it is very likely that the three F4 variants F4ab, F4ac, and F4ad have different receptors that are controlled by three different loci.

Mucosal permeability to lipopolysaccharides in the colon in chronic alcoholic rats

AIMS To evaluate the effects of chronic alcohol abuse on the mucosal permeability to lipopolysaccharide in the colon in rats. METHODS Escherichia coil lipopolysaccharide (LPS,20 μg/ml) was injected into the colon of chronic alcoholic rats (n=10) and the rats were supplied with Lieber diets every other day for 6 weeks. Before LPS injection and 5,10,20,30 minutes after injection, blood samples from the portal vein were obtained and contents of LPS in the blood were measured. The dis- tribution of LPS in the colon tissues was observed with a confocal laser scanning microscope by immunofluo- rescent technique using a monoclonal antibody specific to the lipid A region of LPS. Normal rats were used as controls (n=6). RESULTS Before LPS injection in the colon,LPS levels in the blood of portal vein of chronic alcoholic rats were significantly higher than those of normal con- trols (3.56±0.67 pg/ml,vs 2.45±0.15 pg/ml,P <0.01). At 5,10,20,30 minutes after injection of LPS,LPS contents were significantly higher than those before LPS injection (173.56±23.45 pg/ml,154.78 ±20.57 pg/ml,43.89±8.67 pg/ml,45.38± 7.89 pg/mls vs 3.56±0.67 pg/ml,P<0.01 respectively). Most mucosal cells showed strong posi- tive reactions to LPS in the rats of chronic alcohol abuse,but no significant changes of LPS contents in blood from the portal vein and fluorescent reactions to LPS in mucosal cells of normal rats were found after LPS injection. CONCLUSIONS Chronic alcohol abuse resulted in a significant increase of permeability to LPS in colon mu- cosal cells in rats.

Lymphocytic colitis: A clue to bacterial etiology

AIM： To find out the role of bacteria as a possible etiological factor in lymphocytic colitis. METHODS： Twenty patients with histopathological diagnosis of lymphocytic colitis and 10 normal controls were included in this study. Colonoscopic biopsies were obtained from three sites （hepatic and splenic flexures and rectosigmoid region）. Each biopsy was divided into two parts. A fresh part was incubated on special cultures for bacterial growth. The other part was used for the preparation of histologic tissue sections that were examined for the presence of bacteria with the help of Giemsa stain. RESULTS： Culture of tissue biopsies revealed bacterial growth in 18 out of 20 patients with lymphocytic colitis mostly Escherichia coil （14/18）, which was found in all rectosigmoid specimens （14/14）, but only in 8/14 and 6/14 of splenic and hepatic flexure specimens respectively. In two of these cases, E coli was associated with proteus. Proteus was found only in one case, Klebsiella in two cases, and Staphylococcus aureus in one case. In the control group, only 2 out of 10 controls showed the growth of E coli in their biopsy cultures. Histopathology showed rod-shaped bacilli in the tissue sections of 12 out of 14 cases with positive E coli in their specimen＇s culture. None of the controls showed these bacteria in histopathological sections. CONCLUSION： This preliminary study reports an association between E coli and lymphocytic colitis, based on histological and culture observations. Serotyping and molecular studies are in process to assess the role of E coli in the pathogenesis of lymphocytic colitis.

A simple taurocholate-induced model of severe acute pancreatitis in rats

AIM: To investigate gut barrier damage and intestinal bacteria translocation in severe acute pancreatitis (SAP), a simple rat model of SAP was induced and studied.METHODS: Pancreatitis was induced by uniformly distributed injection of 3.8% Na taurocholate (1 mL/kg) beneath the pancreatic capsule. Rats in the control group were injected with normal saline in the identical location. RESULTS: Serum amylase, plasma endotoxin, intestinal permeability, and pancreatitis pathology scores were all markedly higher in the pancreatitis group than in the control group (P < 0.01). The bacterial infection rate was signif icantly higher in the SAP group than in the control group (P < 0.01), observed in parallel by both bacterial culture and real-time polymerase chain reaction. Acute damage of the pancreas was observed histologically in SAP rats, showing interstitial edema, leukocyte infiltration, acinar cell necrosis and hemorrhage. The microstructure of the intestinal mucosa of SAP ratsappeared to be destroyed with loose, shortened microvilli and rupture of the intercellular junction, as shown by electron microscopy. CONCLUSION: Significant gut barrier damage and intestinal bacterial translocation were def initely observed with few potential study confounders in this SAP rat model, suggesting that it may be an appropriate animal model for study of gut barrier damage and bacterial translocation in SAP.

MOLECULAR CLONING OF hTRT CATALYTIC DOMAIN FROM HeLa CELLS AND ITS EXPRESSION IN E Coli AND PURIFICATION

To investigate the expression of telomerase gene hTRT mRNA in HeLa cells and to obtain hTRT protein for futher study Methods. The gene for encoding hTRT catalytic domain was cloned based on RT PCR amplification from HeLa cells and sequenced The cloned hTRTcDNA was in frame inserted into His tag fusion expression vector pEK318 The His tag hTRT fusion proteins were purified by Ni NTA chromatography and stained by western blotting Results. An approximately 620bp fragment was generated and cloned into pBluescript SK+between SalI and BamHI sites DNA sequencing showed the isolated fragment was consistent to those reported SDS PAGE present that a 17kDa protein was expressed stably in E coli JM109 harboring pEKTRT344 containing 6×His tag and hTRT 150aa, and the expression level of the protein was about 26% of the total bacterial proteins, while the expression of pEKTRT containing 6×His tag and hTRT 243aa was only detectable as 27 kDa band in western blotting Both of fusion proteins were purified by Ni NTA chromatography and showed single band(>95% purifity) in Coomassie Brilliant staining Western blotting confirmed that two proteins could be recognized by the Ni NTA AP conjugate Conclusions. The hTRT catalytic domain was highly conserved The expressed hTRT protein contained recognizable His tag, telomerase specific and strong antigenic epitops, which may be convenient for further investigation

Moxibustion inhibits interleukin-12 and tumor necrosis factor alpha and modulates intestinal flora in rat with ulcerative colitis

AIM: To investigate the effect of moxibustion on intestinal flora and release of interleukin-12 (IL-12) and tumor necrosis factor-α (TNF-α) from the colon in rat with ulcerative colitis (UC). METHODS: A rat model of UC was established by local stimulation of the intestine with supernatant from colonic contents harvested from human UC patients. A total of 40 male Sprague-Dawley rats were randomly divided into the following groups: normal (sham), model (UC), herb-partition moxibustion (HPM-treated), and positive control sulfasalazine (SA-treated). Rats treated with HPM received HPM at acupuncture points ST25 and RN6, once a day for 15 min, for a total of 8 d. Rats in the SA group were perfused with SA twice a day for 8 d. The colonic histopathology was observed by hematoxylin-eosin. The levels of intestinal flora, including Bifidobacterium, Lactobacillus, Escherichia coli (E. coli), and Bacteroides fragilis (B. fragilis), were tested by real-time quantitative polymerase chain reaction to detect bacterial 16S rRNA/DNA in order to determine DNA copy numbers of each specific species. Immunohistochemical assays were used to observe the expression of TNF-α and IL-12 in the rat colons. RESULTS: HPM treatment inhibited immunopathology in colonic tissues of UC rats; the general morphological score and the immunopathological score were significantly decreased in the HPM and SA groups compared with the model group [3.5 (2.0-4.0), 3.0 (1.5-3.5) vs 6.0 (5.5-7.0), P < 0.05 for the general morphological score, and 3.00 (2.00-3.50), 3.00 (2.50-3.50) vs 5.00 (4.50-5.50), P < 0.01 for the immunopathological score]. As measured by DNA copy number, we found that Bifidobacterium and Lactobacillus, which are associated with a healthy colon, were significantly higher in the HPM and SA groups than in the model group (1.395 ± 1.339, 1.461 ± 1.152 vs 0.045 ± 0.036, P < 0.01 for Bifidobacterium, and 0.395 ± 0.325, 0.851 ± 0.651 vs 0.0015 ± 0.0014, P < 0.01 for Lactobacillus). On the other hand, E. coli and B. fragilis, which are associated with an inflamed colon, were significantly lower in the HPM and SA groups than in the model group (0.244 ± 0.107, 0.628 ± 0.257 vs 1.691 ± 0.683, P < 0.01 for E. coli, and 0.351 ± 0.181, 0.416 ± 0.329 vs 1.285 ± 1.039, P < 0.01 for B. fragilis). The expression of TNF-α and IL-12 was decreased after HPM and SA treatment as compared to UC model alone (4970.81 ± 959.78, 6635.45 ± 1135.16 vs 12333.81 ± 680.79, P < 0.01 for TNF-α, and 5528.75 ± 1245.72, 7477.38 ± 1259.16 vs 12550.29 ± 1973.30, P < 0.01 for IL-12). CONCLUSION: HPM treatment can regulate intestinal flora and inhibit the expression of TNF-α and IL-12 in the colon tissues of UC rats, indicating that HPM can improve colonic immune response.

Chloromycetin resistance of clinically isolated E coli is conversed by using EGS technique to repress the Chloromycetin acetyl transferase

AIM： To explore the possibility of repression of chloromycetin （Cm） acyl transferase by using external guided sequence （EGS） in order to converse the clinical E coli isolates from Cm- resistant to Cm- sensitive. METHODS： EGS directed against chloromycetin acetyl transferase gene （cat） was cloned to vector pEGFP-C1 which contains the kanamycin （Kin） resistance gene. The recombinant plasmid pEGFP-C1＋EGScatl＋cat2 was constructed and the blank vector without EGS fragment was used as control plasmids. By using the CaCl2 transformation method, the recombinant plasmids were introduced into the clinically isolated Cm resistant but Km sensitive E coli strains. Transformants were screened on LB agar plates containing Kin. Extraction of plasmids and PCR were applied to identify the positive clones. The growth curve of EGS transformed bacteria cultured in broth with Cm resistance was determined by using spectrophotometer at A600. Drug sensitivity was tested in solid culture containing Cm by using KB method. RESULTS： Transformation studies were carried out on 16 clinically isolated Cm-resistant （250 μg/mL of Cm） E colistrains by using pEGFP-C1-EGScatlcat2 recombinant plasmid. Transformants were screened on LB-agar plates containing Km after the transformation using EGS. Of the 16 tested strains, 4 strains were transformed successfully. Transformants with EGS plasmid showed growth inhibition when grown in liquid broth culture containing 200 μg/mL of Cm. In drug sensitivity test, these strains were sensitive to Cm on LB-agar plates containing 200 μg/mL of Cm. Extraction of plasmids and PCR amplification showed the existence of EGS plasmids in these four transformed strains. These results indicated that the Cat of the four clinical isolates had been suppressed and the four strains were converted to Cm sensitive ones. CONCLUSION： The EGS directed against Cat is able to inhibit the expression of Cat, and hence convert Cm- resistant bacteria to Cm-sensitive ones. Thus, the EGS has the capability of converting the phenotype of clinical drug-resistant isolates strains to drug-sensitive ones.

Management of patients with stercoral perforation of the sigmoid colon:Report of five cases

To our knowledge, stercoral perforation of the colon is rarely seen with fewer than 90 cases reported in the literature till date. We explored the principles of management to prevent impending mortality in five patients with this condition. Five patients, two males and three females, whose median age was 64 years, had sustained stercoral perforation of the sigmoid colon. Chronic constipation was the common symptom among these patients. Three patients underwent a Hartmann＇s procedure and another two were treated with segmental colectomy with anastomosis and diverting colostomy. There was one surgical mortality and the other patients had an uneventful hospital stay. Timely intervention to prevent and/or treat any associated sepsis along with extensive peritoneal lavage and surgical intervention to remove diseased colonic tissue at the primary stercoral ulceration site coupled with aggressive therapy for peritonitis are key treatment modalities in salvaging patients presenting with stercoral perforation of the colon.

Functional morphology of the olfactory organ of the tongue sole, Cynoglossus semilaevis

The morphology and structure of the olfactory organ of Cynoglossus semilaevis Gunther are described. The oval olfactory sacs on both sides differ in size and in the number of lamellae, With those on the abocular side having smaller sacs and fewer lamellae than those on the ocular side. On the ocular side, the average ratio of sac length to eye diameter is 2.1 （i.e.〉1） with an average of 91 lamellae, while on the abocular side, the values were 1.7 （i.e.〉1） and 69, respectively. In addition, the surface morphology varies in different parts of the lamella. The frontal part, near the anterior nostril, is a non-sensory margin with cilia-free epidermal cells. Within this is an internal ciliated sensory area, which is intercalated with ciliated receptor cells and a few ciliated non-sensory cells. Additionally, some dense ciliated non-sensory cells make up a non-sensory area, which also contains cilia-free epidermal cells distributed in patches. In the rear of the olfactory sac near the posterior nostril, the lamellae differ in morphology from those of the frontal olfactory sac but are similar in having few ciliated receptor cells. In other words, the surface of the lamellae in the rear part of the olfactory sac is mainly non-sensory. At present, four types of lamellae （~ E IlIand IV） have been recognized in relation to the pattern of the sensory epithelium. In this study, the frontal and rear lamellae resembled types I and IV, respectively, but are referred to as types r and IV because they are slightly less developed. Data on the ratio of length of lamellae to eye diameter, number of lamellae and the type of surface pattern of the lamellae show that the development of the olfactory system of C. semilaevis facilitates prey capture.

Different antibacterial mechanisms of titania nanotube arrays at various growth phases of E.coli

To clarify the antibacterial behavior at early adhesion,two titania nanotube(TNT)arrays were fabricated on polished commercially pure titanium(Ti),and the interaction mechanisms between TNT arrays and the model bacteria(Escherichia coli,E.coli)were investigated.The results show that TNT arrays exhibit a significant early antibacterial effect,which is highly related to the surface free energy and nano-topography.The underlying antibacterial mechanisms include:(1)the anti-initial-attachment effect at the lag phase(0−4 h);(2)the anti-proliferation and physical bactericidal effects at the logarithmic phase(4−12 h);(3)the reduced antimicrobial properties probably due to the overgrowth of bacteria on TNT arrays at the stationary phase(12 h and then).

An EAL domain protein and cyclic AMP contribute to the interaction between the two quorum sensing systems in Escherichia coli

Quorum sensing （QS） is a bacterial cell-cell communication process by which bacteria communicate using extracellular signals called autoinducers. Two QS systems have been identified in Escherichia coli K-12, including an intact QS system 2 that is stimulated by the cyclic AMP （cAMP）-cAMP receptor protein （CRP） complex and a partial QS system 1 that consists of SdiA （suppressor of cell division inhibitor） responding to signals generated by other microbial species. The relationship between QS system 1 and system 2 in E. coli, however, remains obscure. Here, we show that an EAL domain protein, encoded by ydiV, and cAMP are involved in the interaction between the two QS systems in E. coli. Expression of sdiA and ydiV is inhibited by glucose. SdiA binds to the ydiV promoter region in a dose-dependent, but nonspecific, manner; extracellular autoinducer 1 from other species stimulates ydiV expression in an sdiA-depen- dent manner. Furthermore, we discovered that the double sdiA-ydiV mutation, but not the single mutation, causes a 2-fold decrease in intracellular cAMP concentration that leads to the inhibition of QS system 2. These results indicate that signaling pathways that respond to important environmental cues, such as autoinducers and glucose, are linked together for their control in E. coli.

Observation of Cell-Size Variation under Environmental Stress by Fluorescence Correlation Spectroscopy without Objective Image Magnification

Fluorescence correlation spectroscopy （FCS） without objective image magnification （without using con-focal microscope） was applied to observe the variation in cell size of Escherichia coli （E. coli） induced by the anti-cancer agent MitomycinC （MMC）. In the system without image magnification followed in this study, the suspension of E. coli cells was stirred, and the difference in movement due to the different cell sizes induced by the compulsive solution flow was detected. The addition of 0.1-0.4 pg/L of MMC elongated the E. coli cell length from about 3.6 to 7.8μm. The flow cell （i.d. = about 1 mm） also produced a size-dependent correlation curve, The present system is not based on single molecular FCS but is inexpensive and effective at observing the variation in cell size induced by environmental changes.

Differential expression of bcl-2 and bax genes during the E.coli-induced apoptosis of human U937 cells

To explore the role of bcl-2 and bax genes in the apoptosis of human U937 cells induced by E.coli, flow cytometry assay with annexinⅤ-FITC/PI double staining was used to determine the condition of apoptosis, and the expressions of mRNA of bcl-2 and bax genes were assayed with RT-PCR. It was found that the apoptosis of human U937 cells could be induced by E.coli at various concentration ratios between cells and bacteria for 30 min in a dose-dependent manner. The apoptotic rates at cell/bacteria ratios of 0, 1∶5, 1∶10, 1∶20, 1∶50 and 1∶100 were 3.16%±0.90%, 9.46%±0.84%, 17.90%±1.41%, 35.59%±3.76%, 38.35%±7.12% and 55.07%±5.82% respectively. Also, there was a tendency of alterations in the expression levels of bcl-2 and bax genes with an increased expression level of bax gene and a reduced expression level of bcl-2 gene. It is concluded that E.coli can induce apoptosis in human U937 cells with a down-regulated expression of Bcl-2 and an up-regulated expression of Bax, and this might be related to the induction of apoptosis of the infected cell.

Replication of M13 single-stranded DNA bearing a sitespecific ethenocytosine lesion by Escherichia coil cell extracts

Previous investigation on the mutagenic effects of 3,N4-Ethenocytosine (εC), a nonpairing DNA lesion,revealed the existence of a novel SOS-independent inducible mutagenic mechanism in E. coli termed UVM for UV modulation of mutagenesis. To investigate whether UVM is mediated by an alteration of DNA replication, we have set up an in vitro replication system ill which phage M13 viral single-stranded DNA bearing a single site-specific (εC) residue is replicated by soluble protein extracts from E. coli cells. Replication products were analyzed by agarose gel electrophoresis and the frequency of translesion synthesis was determined by restriction endonuclease analyses. Our data indicate that DNA replication is strongly inhibited by εC, but that translesion DNA synthesis does occur in about 14% of the replicated DNA molecules. These results are very similar to those observed previously in vivo, and suggest that this experimental system may be suitable for evaluating alterations in DNA replication in UVM-induced cells.

Neutron （Magnetic Isotope） Catalysis for Example Isotopes 24,25,26Mg in Cells E. Coli

We offered the new theory of neutron （magnetic isotope） catalysis. For the first time it was shown that the number of neutrons in the atom, which have anomalous magnetic effect, have a great influence on the chemical properties. Our proposed theory of neutron （magnetic isotope） catalysis takes into account the influence of the magnetic field on the catalytic processes.