文化夹缝中的痛苦呻吟——读茅盾的《自杀》

本文试图对《自杀》中的环小姐的复杂矛盾心理和定剧原因作一点解读 ,借以管窥五四时期新旧文化交替之际一部分小资产阶级知识女性的特定心态 ,洞识文化基因对人的深刻影响。

Construction of a vscC in-frame Deletion Mutant of Vibrio alginolyticus

[Objective] The purpose of this study was to construct a vscC in-frame deletion mutant of Vibrio alginolyticus with no antibiotic resistance marker. [Method] The first vscC mutant molecules in vitro were generated by SOE-PCR and then lig- ated to a suicide vector pDM4 to construct a suicide recombinant vector pDM4- A vscC. To clone the recombinant vector, it was transformed to E. coli SY327 strain, and then positive clones were selected and proved by PCR analysis. After that, the pDM4-AvscC DNA was extracted in large numbers and transformed to the E. coil S17-1 strain that acted as a donor in bacterial conjugation using the heat shock method. The recombinant E. coli S17-1 strains then transferred the pDM4-AvscC to V. alginolyticus ZJ51-O by conjugation method; transconjugants were screened and selected sequentially using antibiotic selection strategy and sucrose based counter-selection system to find the suspected mutants wanted. Finally the putative mutants were identified by PCR and confirmed by sequencing analysis. [Result] ZJ51-OAvscC was successfully constructed. [Conclusion] This study laid foundation for further research on the function of vscC gene and molecular mechanism of type Ⅲ secretion system in V. alginolyticus. Simultaneously, by the effective method other unknown functional genes in V. alginolyticus genome would be researched.

Structure modifications based on KRN7000 and their SARs in activating NKT cells

α-Galactosylceramides, which can be recognized by natural killer T （NKT） cells, are now attracting more and more attention due to their therapeutic potential in cancer, infection and autoimmune diseases. Advances have been achieved in discovering compounds with better activities and efforts have been made to understand the structure-activity relationships （SARs） of these NKT cell ligands. In this review, we discuss the structure modifications based on KRN7000, the principal glycolipid used in the study of NKT cell stimulation, and the SARs based on these modified structures.

Construction and Application of Plasmid pUC19-CM-D

[Objective] The aims were to construct a new suicide plasmid of Lactobacillus and gene deletion engineering bacteria of Lactobacillus with pUC19 vector. [Methods] pUC19-CM was constructed by inserting a chloramphenicol resistant gene into the multi-cloning site of pUC19,and then two homologous fragments were cloned into each side of the pUC19-CM to construct suicide plasmid pUC19-CM-D. [Results] A replacement mutant strain,whose target gene was replaced by resistant gene,could be obtained by transforming the suicide plasmid pUC19-CM-D into Lactobacillus for resistance screening. [Conclusion] The construction and application of pUC19-CM-D provided a fast and efficient means of construction of gene deletion engineering bacteria of Lactobacillus,and laid a foundation for study of gene function of Lactobacillus.

Influence of Connexin43 on the Bystander Effect Induced by Double Suicide Genes System in Vitro and in Vivo

Objective： To observe the influence of connexin 43 （Cx43） on the bystander effect induced by cytosine deaminase （CD） and herpes simplex virus thymidine kinase （HSV-tk） coexpression suicide genes system in human cholangiocarcinoma QBC939 cells and transplantation tumors in nude mice. Methods： In vitro, the CD＋tk＋ and CD＋tk＋Cx＋ cells were respectively treated with 5-fluorocytosine （5-Fc） and Ganciclovir （GCV）. The cytotoxic effect was evaluated by MTT method. In order to investigate the influence of Cx43 on the bystander effect, the size of transplantation tumors of the CD＋tk＋ and CD＋tk＋Cx＋ cells was measured before and after application of 5-Fc and GCV. Results： CD and tk genes were stably expressed in transfected QBC939 cells. The increased expression of Cx43 was determined by testing for the presence of Cx43 mRNA by RT-PCR and the presence of Cx43 protein by Western Blot in CD＋tk＋Cx＋ cells. The killing effect of 5-Fc and GCV on CD＋tk＋Cx＋ cells was more effective than that on CD＋tk＋ cells both in vitro and in vivo. Conclusion： Double suicide genes system CD/5-Fc＋tk/GCV could induce remarkable killing effect on cholangiocarcinoma cells in vitro and transplantation tumors in vivo. The cotransfection of Cx43 gene could enhance the bystander effect and hence the inhibition of carcinoma cells.

Antitumor effects and radiosensitization of cytosine deaminase and thymidine kinase fusion suicide gene on colorectal carcinoma cells

AIM: To investigate the killing effect and radiosensitization of double suicide gene mediated by adenovirus on colorectal carcinoma cells. METHODS: Colorectal carcinoma cell line SW480 was transfected with adenovirus expression vector containing cytosine deaminase (CD) and thymidine kinase (TK) fusion gene. The expression of CD-TK fusion gene was detected by reverse transcriptase-polymerase chain reaction. The toxic effect of ganciclovir (GCV) and 5-fluorocytosine (5-FC) on infected cells was determined by MTT assay. The radiosensitization of double suicide gene was evaluated by clonogenic assay. RESULTS: After prodrugs were used, the survival rate of colorectal carcinoma cells was markedly decreased. When GCV and 5-FC were used in combination, the cytotoxicity and bystander effect were markedly superior to a single prodrug (X2 = 30.371, P<0.01). Both GCV and 5-FC could sensitize colorectal carcinoma cells to the toxic effect of radiation, and greater radiosensitization was achieved when both prodrug were used in combination. CONCLUSION: CD-TK double suicide gene can kill and radiosensitize colorectal carcinoma cells.

Kinase domain insert containing receptor promoter controlled suicide gene system selectively kills human umbilical vein endothelial cells

AIM： To study the selective killing of human umbilical vein endothelial cells （HUVECs） by a double suicide gene under the regulation of a kinase domain insert containing receptor （KDR） promoter and mediated by an adenoviral gene vector. METHODS： Human KDR promoter was cloned by polymerase chain reaction （PCR）, and two recombinant adenoviral plasmids pAdKDR-CdgIyTK, pAdCMV-CDglyTK were constructed according to a two-step transformation protocol. These two newly constructed plasmids were then transfected into 293 packaging cells to grow adenovirus, which were further multiplied and purified. HUVECs and LoVo cells were infected with either of the two resultant recombinant adenoviruses （AdKDR-CDglyTK and AdCMV-CDglyTK） respectively, and the infection rates were estimated by detection of green fluorescent protein （GFP） expression. Infected cells were cultured in culture media containing different concentrations of 5-fiuoroo/tosine （5-FC） and ganciclovir （GCV）, and the killing effects were measured. RESULTS： The two recombinant adenoviral plasmids pAdKDR-CdglyTK, pAdCMV-CDglyTK were successfully constructed and transfected into 293 cells. The resultant recombinant adenoviruses infected cells caused similar infection rates; and the infected cells exhibited different sensitivity to the prodrugs： HUVECs infected with AdCMV-CDglyTK and LoVo cells infected with AdCMVo CDglyTK were highly sensitive to the prodrugs, and HUVECs infected with AdKDR-CDglyTK were similarly sensitive but significantly more sensitive than the LoVo cells infected with AdKDR-CdglyTK （P 〈 0.001）. CONCLUSION： Selective killing of HUVECs may be achieved by gene transfer of double suicide gene under the regulation of the KDR promoter. This finding may provide an optional way to target gene therapy of malignant tumors by abrogation of tumor blood vessels.

Cytokines as critical co-stimulatory molecules in modulating the immune response of natural killer cells

Cytokines are involved in directing the activation of natural killer （NK） cells. NK cells are involved in the recognition of cells that have been altered; thus they do not recognize specific insults to the host, but when activated, are capable of destroying infected cells directly, as well as promoting the recruitment and response of the other components of the immune system by the release of cytokines and chemokines. It is these properties that have made NK cells a critical part of innate immunity and adaptive immunity, and they play a principal role linking innate and adaptive immunity by the recruitment of an adaptive immune response to an innate immune reaction.

Acaricidal activities of some essential oils and their monoterpenoidal constituents against house dust mite,Dermatophagoides pteronyssinus (Acari:Pyroglyphidae)

The acaricidal activities of fourteen essential oils and fourteen of their major monoterpenoids were tested against house dust mites Dermatophagoides pteronyssinus. Five concentrations were used over two different time intervals 24 and 48 h under laboratory conditions. In general, it was noticed that the acaricidal effect based on LC50 of either essential oils or monoterpenoids against the mite was time dependant. The LCso values were decreased by increasing of exposure time. Clove, matrecary, chenopodium, rosemary, eucalyptus and caraway oils were shown to have high activity. As for the monoterpenoids, cinnamaldehyde and chlorothymol were found to be the most effective followed by citronellol. This study suggests the use of the essential oils and their major constituents as ecofriendly biodegradable agents for the control of house dust mite, D. pteronyssinus.

Kinase domain insert containing receptor promotor controlled suicide gene system kills human umbilical vein endothelial cells

AIM: To evaluate the killing effect of double suicide gene mediated by adenovirus and regulated under kinase domain insert containing receptor (KDR) promoter on human umbilical vein endothelial cells. METHODS: By PCR technology, human KDR promoter gene, Escherichia coli(E. coli) cytosine deaminase (CD) gene and the herpes simple virus-thymidine kinase (TK) gene were cloned. Plasmid pKDR-CDglyTK was constructed with them. Then, a recombinant adenoviral plasmid pAdKDRCDglyTK was constructed in a 'two-step transformation protocol'. The newly constructed plasmids were transfected to 293 packaging cells to grow adenoviruses, which were further propagated and purified. Human umbilical vein endothelial cells (HUVEC) were infected with a different multiplicity of infection (MOI) of resultant recombinant adenovirus, the infection rate was measured with the aid of (GFP) expression. Infected cells were cultured in culture media containing different concentrations of (GCV) and/or 5-(FC), and the killing effects were measured.RESULTS: Recombinant adenoviruses AdKDR-CDglyTK were successfully constructed, and they infected HUVEC cells efficiently. Our data indicated that the infection rate was relevant to MOI of recombinant adenoviruses. HUVEC cells infected with AdKDR-CDglyTK were highly sensitive to the prodrugs, their survival rate correlated to both the concentration of the prodrugs and the MOI of recombinant adenoviruses. Our data also indicated that the two prodrugs used in combination were much more effective on killing transgeneic cells than GCV or 5-FC used alone. CONCLUSION: Prodrug/KDR-CDglyTK system is effective on killing HUVEC cells, its killing effect correlates to the concentration of prodrugs and recombinant adenovirus' MOI. Combined use of the two prodrugs confers better killing effects on transgeneic cells.

Bifunctional chimeric SuperCD suicide gene -YCD: YUPRT fusion is highly effective in a rat hepatoma model

AIM： To investigate the effects of catalytically superior gene-directed enzyme prodrug therapy systems on a rat hepatoma model. METHODS： To increase hepatoma cell chemosensitivity for the prodrug 5-fluorocytosine （5-FC）, we generated a chimeric bifunctional SuperCD suicide gene, a fusion of the yeast cytosine deaminase （YCD） and the yeast uracil phosphoribosyltransferase （YUPRT） gene. RESULTS： In vitro stably transduced Morris rat hepatoma cells （MH） expressing the bifunctional SuperCD suicide gene （MH SuperCD） showed a clearly marked enhancement in cell killing when incubated with 5-FC as compared with MH cells stably expressing YCD solely （MH YCD） or the cytosine deaminase gene of bacterial origin （MH BCD）, respectively. In vivo, MH SuperCD tumors implanted both subcutaneously as well as orthotopically into the livers of syngeneic ACI rats demonstrated significant tumor regressions （P〈0.01） under both high dose as well as low dose systemic 5-FC application, whereas MH tumors without transgene expression （MH naive） showed rapid progression. For the first time, an order of in vivo suicide gene effectiveness （SuperCD〉〉 YCD〉〉BCD〉〉〉negative control） was defined as a result of a direct in vivo comparison of all three suicide genes. CONCLUSION： Bifunctional SuperCD suicide gene expression is highly effective in a rat hepatoma model, thereby significantly improving both the therapeutic index and the efficacy of hepatocellular carcinoma killing by fluorocytosine.

Health personnel-targeted education interventions on inpatient suicide prevention in general hospitals:A scoping review

Background:Inpatient suicide is an important part of patient safety management in general hospitals.Incidence of inpatient suicide can be decreased by health personnel mastering inpatient suicide prevention strategy.To enhance health personnel’s inpatient suicide prevention strategy,education intervention is a common method.Educational interventions in the researches varied in contents,duration and outcome measurements.However,there has been not synthesis of education interventions targeting health personnel on inpatient suicide prevention.Objective:Prevention of inpatient suicide is a critical priority in patient safety management in general hospitals.Incidence of inpatient suicide can be decreased by effective strategies mastered by health personnel through education interventions.Educational interventions in researches varied in contents,duration and outcome measurements.We aimed to review education interventions targeting health personnel on inpatient suicide prevention.Methods:A scoping review was used to analyze existing researches on education interventions targeting health personnel focusing on inpatient suicide prevention in general hospitals.Cochrane Library,PubMed,Embase,CINAHL,China National Knowledge Infrastructure,WanFang,and Chinese Scientific Journal Database were searched in Oct 2019.According to the inclusion and exclusion criteria,the searched studies were screened by two reviewers.And then,two researchers conducted the data extraction independently by using a table format,including the first author,year of publication,study design,participants,education intervention,etc.Results:Twelve studies were included in this scoping review.The contents of education interventions on inpatient suicide prevention included three aspects:suicide knowledge,suicide assessment,and skills for coping with suicide.The duration of education interventions ranged from 1.5-h to 32.0-h.The effects of education interventions were mainly focused on participants’knowledge,attitudes and skills of suicide prevention.Conclusion:The evidence showed that education interventions on inpatient suicide prevention had positive impact on health personnel’s knowledge,attitude and skills about inpatient suicide prevention in general hospitals.However,the best health personnel-targeted education intervention on inpatient suicide prevention in general hospitals was yet to be determined.In the future,it is necessary to combine evidence in this review and the actual condition in clinical practice.

Consumption of purple sweet potato leaves modulates human immune response: T-lymphocyte functions, lytic activity of natural killer cell and antibody production

AIM： To study the immunological effects of physiologica doses of purple sweet potato leaves （PSPL）. METHODS： The randomized crossover study （two periods, each lasting for 2 wk） involved 16 healthy non-smoking adults of normal weight. The 6-wk study consisted of a run-in （wk 1） PSPL diet （daily consumption of 200 g PSPL） or a control diet （low polyphenols, with the amount of carotenoids adjusted to the same level as that of PSPL） （wk 2-3）, washout diet （wk 4）, and switched diet （wk 5-6）. Fasting blood was collected weekly in the morning. T-lymphocyte function was assessed via the proliferation and secretion of immunoreactive cytokines. Salivary IgA secretion and the specific cytotoxic activities of cytotoxic T lymphocytes and natural killer （NK） cells were determined. RESULTS： The plasma 13-carotene level increased with time in both groups, while the plasma polyphenol level decreased in the control group, and no significant difference was detected between the two groups. Although p^asma polyphenol levels did not significantly increase in the PSPL group at the end of the study, they were significantly elevated in urine. PSPL consumption produced a significant increase in proliferation responsiveness of peripheral blood mononuclear cells （PBMC） and their secretion of immunoreactive IL-2 and IL-4. As well, lytic activity in NK cells was elevated in a time-dependent fashion. Salivary IgA secretion significantly decreased in control group after 2 wk, and returned to baseline following dietary switch to PSPL. CONCLUSION： Consumption of PSPL modulates various immune functions including increased proliferation responsiveness of PBMC, secretion of cytokines IL-2 and IL-4, and the lytic activity of NK cells. The responsible determinants of PSPL remain to be elucidated, as does the biological significance of the present observations.

Hepatic stellate cells and innate immunity in alcoholic liver disease

Constant alcohol consumption is a major cause of chronic liver disease, and there has been a growing concern regarding the increased mortality rates worldwide. Alcoholic liver diseases (ALDs) range from mild to more severe conditions, such as steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. The liver is enriched with innate immune cells (e.g. natural killer cells and Kupffer cells) and hepatic stellate cells (HSCs), and interestingly, emerging evidence suggests that innate immunity contributes to the development of ALDs (e.g. steatohepatitis and liver fibrosis). Indeed, HSCs play a crucial role in alcoholic steatosis via production of endocannabinoid and retinol metabolites. This review describes the roles of the innate immunity and HSCs in the pathogenesis of ALDs, and suggests therapeutic targets and strategies to assist in the reduction of ALD.

Selective decrease in colonic CD56^+ T and CD161^+ T cells in the inflamed mucosa of patients with ulcerative colitis

AIM： To investigate the role of local colonic mucosal NK receptor-positive T （NKR＋ T） cells in the regulation of intestinal inflammation, we analyzed the population and function of these cells in ulcerative colitis （UC）. METHODS： Colonic mucosal tissues were obtained from colonoscopic biopsies of the descending colon from 96 patients with UC （51 endoscopically uninflamed, 45 inflamed） and 18 normal controls. Endoscopic appearance and histologic score at the biopsied site were determined by MaLts＇ classification. A single cell suspension was prepared from each biopsy by collagenase digestion. Two NKR^＋ T cell subsets, CD56^＋ （CD56^＋CD3^＋） T cells and CD161＋ （CD161^＋CD3^＋） T cells, were detected by flow cytometric analysis. Intracellular cytokine analysis for anti-inflammatory cytokine interleukin-10 （IL-10） was performed by in vitro stimulation with phorbol-myristateacetate （PMA） and ionomycin. RESULTS： CD56^＋ T cells and CD161^＋ T cells are present in the normal human colon and account for 6.7% and 21.3% of all mononuclear cells, respectively. The populations of both CD56＋ T cells and CD161^＋ T cells were decreased significantly in the inflamed mucosa of UC. In contrast, the frequency of conventional T cells （CD56 CD3^＋ cells and CD161CD3^＋ cells） was similar among the patient and control groups. The populations of NKR^＋ T cells were correlated inversely with the severity of inflammation, which was classified according to the endoscopic and histologic Marts＇ criteria. Interestingly, approximately 4% of mucosal NKR＋ T cells expressing IL-10 were detected by in vitro stimulation with PMA and ionomycin.CONCLUSION： Selective reduction in the population of colonic mucosal NKR＋T cells may contribute to the development of intestinal inflammation in UC.

Inositol hexaphosphate-induced enhancement of natural killer cell activity correlates with suppression of colon carcinogenesis in rats

AIM： To investigate the anti-neoplastic effect of inositol hexaphosphate （InsP6 or phytic acid） on dimethylhydrazine （DMH）-induced colon tumor in rats and its effect on blood natural killer （NK） cell activity. METHODS： Healthy Wistar rats, 4 wk old, were divided into control group （fed with common food） and InsP6 group （fed with common food＋2% sodium inositol hexaphosphate in the drinking water）, 15 rats in each group. Both groups were injected with 1,2-dimethylhydrazine subcutaneously （20 mg/kg body weight） once a week for 20 wk. Rats were killed after 21 wk. The whole large intestine was isolated to determine the general condition of tumors and to test blood NK cell activity by lactate-dehydrogenase-release assay. RESULTS： Administration of InsP6 significantly increased blood NK cell activity in DMH-induced colorectal tumor in rats. InsP6 group had a smaller tumor size on average and a smaller number of tumors than the control group. Its mortality was also higher than that in control. However, the variables of body weight and tumor incidence were not significantly different between the two groups. CONCLUSION： InsP6 can increase blood NK cell activity in DMH-induced colon tumor in rats and inhibit tumor growth and metastasis in rats.

NKT cells in HIV-1 infection

Natural killer T （NKT） cells are a unique T cell population that have important immunoregulatory functions and have been shown to be involved in host immunity against a range of microorganisms. It also emerges that they might play a role in HIV-1 infection, and therefore be selectively depleted during the early stages of infection. Recent studies are reviewed regarding the dynamics of NKT depletion during HIV-1 infection and their recovery under highly active antiretroviral treatment （HAART）. Possible mechanisms for these changes are proposed based on the recent developments in HIV pathogenesis. Further discussions are focused on HIV＇s disruption of NKT activation by downregulating CDld expression on antigen presentation cells （APC）. HIV-1 protein Nefis found to play the major role by interrupting the intracellular trafficking of nascent and recycling CDld molecules.

Expression of prolactin receptor and response to prolactin stimulation of human NK cell lines

We have previously shown a critical role of prolactin (PRL) during maturation and anti-tumor effects of murine natural killer (NK) cells in vitro and in vivo. We extended that study by exploring the ability of human NK cell lines (NK-92 and YT cell) to express PRL receptor (PRL-R) and to respond to PRL stimulation in vitro. Both human NK cell lines constitutively expressed PRL-R on membrane and mRNA transcripts,NK-92 cells contained higher level of PRL-R than YT cells,which correlated to the enhanced capacity of the cells to proliferate and to lyse target cells in response to PRL stimulation in the presence of trace amount of IL-2 or IL-15 in vitro. Two differences between IL-2 and IL-15 in functioning on human NK cells were for the first time observed. PRL synergized with IL-15 to improve proliferation of NK cells in a dose-dependent manner without double peak manifesting like IL-2. Although PRL enhanced the cytotoxicity of IL-2 or IL- 15 activated NK cells,it exerted the function through up-regulating gene expression of perforin without influence of FasL in IL-2-stimulated NK cells,while in IL-15-stimulated NK cells,PRL did the function through up-regulating gene expression of both perforin and FasL but not IFNγ. PRL increased expressions of IL-2Rα on membrane and of IL-2 mRNA in cells,indicating that PRL up-regulated NK cell function by improving positive feedback between IL-2 and IL-2R. The similar results were also observed in network between IL-15 and IL-15R. These data indicate a potential role of PRL in human NK cell modulation.

Epidemiology and gene markers of ulcerative colitis in the Chinese

Inflammatory bowel disease （IBD） includes two similar yet distinct conditions called ulcerative colitis （UC） and Crohn＇s disease （CD）. These diseases affect the digestive system and cause the inflammation of intestinal tissue, form sores and bleed easily. Most children with IBD are diagnosed in late childhood and adolescence. However, both UC and CD have been reported as early as in infancy. Most information pertaining to the epidemiology of IBD is based upon adult studies. Symptoms include abdominal pain, cramping, fatigue and diarrhea. Genetic factors play a significant role in determining IBD susceptibility. Epidemiological data support a genetic contribution to the pathogenesis of IBD. Recently, numerous new genes have been identified as being involved in the genetic susceptibility to IBD： TNF- 308A, CARD15 （NOD2）, MIF-173, N-acetyltransferase 2 （NAT2）, NKG2D （natural killer cell 2D）, STAT6 （signal transducer and activator of transcription 6）, CTLA-4 （cytotoxic T lymphocyte antigen-4）, MICA-MICB （major histocompatibility complex A and B）, HLA-DRB1, HLA class-Ⅱ, IL-18, IL-4, MICA-A5, CD14, TI R4, Fas-670, p53 and NF-kB. The characterization of these novel genes has the potential to identify therapeutic agents and aid clinical assessment of phenotype and prognosis in patients with IBD （UC and CD）.

Extranodal natural killer/T-cell lymphoma,nasal type:epidemiology study

Extranodal natural killer （NK）IT-cell lymphoma, nasal type （ENKTCL） is a rarely kind of non-Hodgkin lymphoma （NHL）. It is much more frequent in Asian and Latin American countries than other part of the world. It typically affects nasal cavity. In China, one of its endemically places, ENKTCL accounts for 74%-96% of nasal NHL. Patients with ENKTCL usually show a highly aggressive clinical course, and its etiology is unclear. However, it is already proved that ENKTCL is associated with Epstein-Barr virus （EBV） infection, regardless patients＇, ethnicity and areas. Some studies show that the risk will increase among several occupations, such as farmer, who are frequently exposure to pesticides and chemical solvent and risk can be cut down if taking some protective measures.