Generating Heterokaryotic Cells via Bacterial Cell-Cell Fusion.

Fusion of cells is an important and common biological process that leads to the mixing of cellular contents and the formation of multinuclear cells. Cell fusion occurs when distinct membranes are brought into proximity of one another and merge to become one. Fusion holds promise for biotechnological innovations, for instance, for the discovery of urgently needed new antibiotics. Here, we used antibiotic-producing bacteria that can proliferate without their cell wall as a model to investigate cell-cell fusion. We found that fusion between genetically distinct cells yields heterokaryons that are viable, contain multiple selection markers, and show increased antimicrobial activity. The rate of fusion induced using physical and chemical methods was dependent on membrane fluidity, which is related to lipid composition as a function of cellular age. Finally, by using an innovative system of synthetic membrane-associated lipopeptides, we achieved targeted fusion between distinctly marked cells to further enhance fusion efficiency. These results provide a molecular handle to understand and control cell-cell fusion, which can be used in the future for the discovery of new drugs. IMPORTANCE Cell-cell fusion is instrumental in introducing different sets of genes in the same environment, which subsequently leads to diversity. There is need for new protocols to fuse cells of different types together for biotechnological applications like drug discovery. We present here wall-deficient cells as a platform for the same. We identify the fluidity of the membrane as an important characteristic for the process of fusion. We demonstrate a cell-specific approach for fusion using synthetically designed peptides yielding cells with modified antibiotic production profiles. Overall, wall-deficient cells can be a chassis for innovative metabolite production by providing an alternative method for cell-cell fusion.

Association between chronic illness resources and health behaviors in hypertensive stroke patients at 6 months after discharge: a cross-sectional study.

Background: The adoption of appropriate health behaviors can prevent the recurrence of stroke. Previous research found a downward trend in hypertensive stroke patients' health behaviors from 3 to 6 months after discharge. The provision of appropriate support by chronic illness resources has been shown to predict patients' engagement in appropriate health behaviors in other chronic illness populations. This study sought to explore the association between chronic illness resources and health behaviors in hypertensive stroke patients in order to provide a foundation for the secondary prevention of stroke. Methods: Using convenience sampling method, we enrolled 133 hypertensive stroke patients at 6 months after discharge in Guangzhou, China. All the patients completed a demographic and disease-specific questionnaire, the Health Behavior Scale for Stroke Patients (HBS-SP) and the Chronic Illness Resources Survey (CIRS). A multiple stepwise regression analysis was conducted to test the association of chronic illness resources with health behaviors. Results: The total scores of the HBS-SP and CIRS were (2.89±0.38) and (2.94±0.66), respectively. The correlation coefficient for chronic illness resources and health behaviors was 0.517 (P<0.001). The positive association between chronic illness resources and health behaviors remained statistically significant after controlling for gender, education level, and the Barthel Index (unstandardized coefficient: 0.317, P<0.001). Conclusions: The chronic illness resources has positive association with health behaviors in hypertensive stroke patients at 6 months after discharge. A good support provided by chronic illness resources may contribute to promote positive health behaviors, and thus prevent the recurrence of stroke.

Magnetic-Activated Cell Sorting Using Coiled-Coil Peptides: An Alternative Strategy for Isolating Cells with High Efficiency and Specificity.

Magnetic-activated cell sorting (MACS) is an affinity-based technique used to separate cells according to the presence of specific markers. Current MACS systems generally require an antigen to be expressed at the cell surface; these antigen-presenting cells subsequently interact with antibody-labeled magnetic particles, facilitating separation. Here, we present an alternative MACS method based on coiled-coil peptide interactions. We demonstrate that HeLa, CHO, and NIH3T3 cells can either incorporate a lipid-modified coiled-coil-forming peptide into their membrane, or that the cells can be transfected with a plasmid containing a gene encoding a coiled-coil-forming peptide. Iron oxide particles are functionalized with the complementary peptide and, upon incubation with the cells, labeled cells are facilely separated from nonlabeled populations. In addition, the resulting cells and particles can be treated with trypsin to facilitate detachment of the cells from the particles. Therefore, our new MACS method promotes efficient cell sorting of different cell lines, without the need for antigen presentation, and enables simple detachment of the magnetic particles from cells after the sorting process. Such a system can be applied to rapidly developing, sensitive research areas, such as the separation of genetically modified cells from their unmodified counterparts.

Effects of a Comprehensive Reminder System Based on the Health Belief Model for Patients Who Have Had a Stroke on Health Behaviors, Blood Pressure, Disability, and Recurrence From Baseline to 6 Months: A Randomized Controlled Trial.

BACKGROUND: The health behaviors and blood pressure control of patients with hypertension who have had a stroke are unsatisfactory. A protocol of a comprehensive reminder system has been published, and the results of 3 months of implementation have demonstrated improved patient health behaviors and blood pressure control. The continuity of the intervention effect on these variables after 3 months was not clear. OBJECTIVE: The aim of this study was to determine the impact of a comprehensive reminder system intervention on health behaviors, medication adherence, blood pressure, disability, and stroke recurrence in patients with hypertension who have had a stroke from baseline to 6 months after discharge. METHOD: A multicenter, assessor-blinded, randomized controlled trial was conducted with 174 patients with hypertension who have had a stroke. The intervention consisted of health belief education, a calendar handbook, weekly short message services, and telephone interviews. Data were collected at baseline and at 3 and 6 months after discharge. RESULTS: Repeated-measures analysis of variance and single-effect analysis revealed that, compared with the control group, improvements of health behaviors, medication adherence, blood pressure, and disability of participants in the intervention group were superior. From 3 to 6 months after discharge, these trends remained or continually improved, whereas a downward trend was observed in the control group. There were only 2 stroke recurrences within 6 months, and no statistically significant difference between groups was found. CONCLUSION: The comprehensive reminder system improved patients' health behaviors and medication adherence and reduced blood pressure and disability; the effect extended to 6 months after discharge.

Stabilizing G-quadruplex DNA by methylazacalix[n]pyridine through shape-complementary interaction.

It is found that G-quadruplexes have important functions in biological systems, such as gene expression. Molecules which can stabilize the G-quadruplex structure may have potential application in regulating the expression of gene. A series of methylazacalix[n]pyridine (n=4, 6, 7, 8, 9) has been tested to stabilize the intermolecular human telomeric G-quadruplex (T12 and H12), intramolecular TBA, c-kit and bcl-2 G-quadruplex by CD denaturation experiments. The results showed that only methylazacalix[6]pyridine (MACP6) can stabilize the intermolecular G-quadruplex formed from the 12bp human telomere. Further studies evidenced that the shape-complementary binding mode was what contributed to the interaction between MACP6 and T12 G-quadruplex.

G-quadruplex induced chirality of methylazacalix[6]pyridine via unprecedented binding stoichiometry: en route to multiplex controlled molecular switch.

Nucleic acid based molecular device is a developing research field which attracts great interests in material for building machinelike nanodevices. G-quadruplex, as a new type of DNA secondary structures, can be harnessed to construct molecular device owing to its rich structural polymorphism. Herein, we developed a switching system based on G-quadruplexes and methylazacalix[6]pyridine (MACP6). The induced circular dichroism (CD) signal of MACP6 was used to monitor the switch controlled by temperature or pH value. Furthermore, the CD titration, Job-plot, variable temperature CD and (1)H-NMR experiments not only confirmed the binding mode between MACP6 and G-quadruplex, but also explained the difference switching effect of MACP6 and various G-quadruplexes. The established strategy has the potential to be used as the chiral probe for specific G-quadruplex recognition.

[Screening and clinical phenotype analysis of microdeletions of azoospermia factor region on Y chromosome in 1011 infertile men].

OBJECTIVE: To investigate the prevalence and subtypes of microdeletions in azoospermia factor (AZF) region in infertile men from Sichuan in order to correlate genotypes with phenotypes. METHODS: Multiplex-PCR was used to detect sequence tagged sites (STS) of AZF microdeletions in 1011 infertile men including 713 cases of non-obstructive azoospermia and 298 cases of severe oligospermia. RESULTS: The overall prevalence of microdeletions was 10.48% (106/1011), and the deletion rates were 11.08% (79/713) in non-obstructive azoospermia and 9.06% (27/298) in severe oligospermia. Complete AZFa or AZFb deletions were associated with azoospermia, whereas AZFc deletion (60.38%) was the most frequent deletion. The deletions were associated with variable spermatogenic phenotypes, and 37.50% of the patients with a deletion had sperms in the ejaculate. A mild decline in sperm concentration was found in two cases with partial AZFb deletion and one case with partial AZFb-c deletion. CONCLUSION: Deletions of the AZFc region were most commonly found in our patients. All cases with complete AZFa or AZFb deletions and a proportion of cases with AZFc deletion were associated with azoospermia. Our study has provided more insight into the genotype-phenotype correlation, and confirmed that Yq microdeletion screening has a significant value for the diagnosis for male infertility.

[Analysis of benzoic acid content in Radix Paeoniae Alba treated by different process].

OBJECTIVE: To analyze the benzoic acid content in the Radix Paeoniae Alba treated by three kinds of process. METHODS: After harvesting, the fresh roots were processed as follows: stored in low temperature, dried after boiling a few minutes and dried immediately. Then the content of benzoic acid was determined by UV spectrophotometry. RESULTS: The content of benzoic acid in the above material without outer part of the cortex was at the higher level than those with outer part of the cortex. In material without outer part of the cortex, the content of benzoic acid was 0.0635% in stored sample, 0.0248% in poaching sample, 0.0639% in dried sample, 0.6635% in part of the cortex. CONCLUSION: Benzoic acid was mostly distributed in the root cortex, Radix Paeoniae Alba treated by boiling can reduce the benzoic acid content. Fresh roots without cortex are comparatively economical and reasonable in distilling Paeoniflorin.