Ru-Based Organometallic Agents Bearing Phenyl Hydroxide: Synthesis and Antibacterial Mechanism Study against Staphylococcus aureus.

The development of antimicrobial agents with novel model of actions is a promising strategy to combat multiple resistant bacteria. Here, three ruthenium-based complexes, which acted as potential antimicrobial agents, were synthesized and characterized. Importantly, three complexes all showed strong bactericidal potency against Staphylococcus aureus. In particular, the most active one has a MIC of 6.25 µg/mL. Mechanistic studies indicated that ruthenium complex killed S. aureus by releasing ROS and damaging the integrity of bacterial cell membrane. In addition, the most active complex not only could inhibit the biofilm formation and hemolytic toxin secretion of S. aureus, but also serve as a potential antimicrobial adjuvant as well, which showed synergistic effects with eight traditional antibiotics. Finally, both G. mellonella larva infection model and mouse skin infection model all demonstrated that ruthenium complex also showed significant efficacy against S. aureus in vivo. In summary, our study suggested that ruthenium-based complexes bearing a phenyl hydroxide are promising antimicrobial agents for combating S. aureus.

Effect of different body position on anorectal manometry for chronic constipation patients.

OBJECTIVE: To analyze the different influence of body position on wireless high-resolution anorectal manometry parameters and in classification for chronic constipation patients. PATIENTS AND METHODS: Fifty consecutive patients with chronic constipation and 20 healthy volunteers were included in this study, all of whom accepted the Rome IV constipation questionnaires, underwent rectal balloon expulsion test and wireless high-resolution anorectal manometry. The wireless high-resolution anorectal manometry was performed in the left lateral, seated, and squatting positions for every study subject. The Statistical Product and Service Solutions (SPSS) 21.0 software (IBM Corp., Armonk, NY, USA) was used for statistical analysis. RESULTS: The anal sphincter resting pressure, anal sphincter squeezing pressure, and rectal internal pressure during the evacuation in the seated position and squatting position were significantly higher than those in the left lateral position in both the volunteer group and patient group, without a significant difference between the seated position and squatting position. The initial perception threshold was higher in the patient group than in the volunteer group. The wireless high-resolution anorectal manometry in different positions combined with the rectal balloon expulsion test mainly affects the diagnosis of the subtype of inadequate defecatory propulsion. CONCLUSIONS: Compared with the left lateral position test, the wireless high-resolution anorectal manometry in the seated position and squatting positions is more consistent with the human physiological bowel condition, and the result of the test can be affected by the body position. The wireless high-resolution anorectal manometry can differentiate between subtypes during the diagnosis of inadequate defecatory propulsion.

[Survey on extramarital sexual behaviors and HIV infection in middle-aged and elderly people aged 50 and above in selected areas of Chongqing].

Objective: To know the situation of extramarital sexual behaviors and HIV infection in middle-aged and elderly people in Chongqing, and provide reference for AIDS prevention and treatment. Methods: From October to December 2017, a multi-stage sampling method was used to recruit middleaged and elderly people aged ≥50 years who lived in Dazu and Hechuan districts of Chongqing for at least one year, with a sample size of 410. Face-to-face questionnaires survey and HIV antibody test were conducted. Results: A total of 408 people were surveyed, including 313 males and 95 females aged 50-88 (64.93±9.03) years. The HIV infection rate was 1.47% (6/408), with the rate of 1.28% (4/313) in males and 2.11% (2/95) in females. The awareness rate of AIDS related knowledge was 37.50% (153/408). And 18.87% (77/408) of subjects surveyed reported extramarital sexual behaviors, 7.60% (31/408) reported extramarital sexual behaviors in the past half year, the constant condom use rate was 19.35% (6/31). The results of multivariate logistics model analysis on extramarital sexual behaviors showed that the prevalence in males were 39.51 times higher than that in females (OR=39.51, 95%CI: 5.03-310.30), 4.60 times higher in those who were unmarried, divorced or widowed than that in the married or cohabitants (OR=4.60, 95%CI: 1.50-14.05), 2.03 times higher in those with outside activities than those with individual activities (OR=2.03, 95%CI: 1.08-3.81) and 3.94 times higher in those with self-evaluation of emptiness of living state than that in those with engaged life (OR=3.94, 95%CI: 1.86-8.36). Conclusions: The prevalence of extramarital sexual behavior in middle-aged and elderly people in some counties and districts in Chongqing is high. The factors such as gender, marital status, leisure activities, and self-evaluation of living state were related to the prevalence of extramarital sexual behaviors in this population. The condom use rate in extramarital sexual behavior was low. It is necessary to take effective interventions in this population.

Inhibition effects of acridone on the growth of breast cancer cells in vivo.

OBJECTIVE: To investigate the anti-tumor effect of acridone against breast cancer in vivo and provide a therapeutic agent for treatment of breast cancer. MATERIALS AND METHODS: The nude mice xenografted tumor model was established by MCF-7 cells. The mice were randomly divided into four groups. The mice in each group (n=6) were intraperitoneally injected with 0.1 mg/kg saline (low-dose), 0.5 mg/kg (middle-dose) and 1.0 mg/kg (high-dose) of acridone for 21 days, respectively. At the end of the animal experiment, the weight of tumors was recorded to calculate the tumor inhibition rate. The serum hormone levels in peripheral blood were determined using ELISA. Hematoxylin and eosin (HE) staining was used to analyze the histopathological changes. The expression of ABCG2 protein and mRNA were determined by Western blot and RT-PCR, respectively. RESULTS: The inhibition rates of tumor growth in the high-dose, middle-dose, and low-dose groups were 29.18%, 17.21%, and 4.27%, respectively. Compared with control and low-dose group, the tumors growth rate in high-dose and middle-dose groups were decreased significantly. Histologically, the tumors were inhibited in the growth rate, the tissue structure was broken. Estrogen in all groups with acridone treatment decreased, the progesterone in high-dose and middle-dose groups increased remarkably. The expression of ABCG2 protein and ABCG2 mRNA decreased after treatment with acridone. CONCLUSIONS: We showed that acridone could induce cell apoptosis, inhibited ABCG2 (ATP-binding cassette sub-family G member 2) protein and adjusted hormone level. The results suggested that acridone could serve as a chemotherapeutic agent for treatment of breast cancer in vivo.

Metformin promotes irisin release from murine skeletal muscle independently of AMP-activated protein kinase activation.

AIM: Irisin, a novel myocyte-secreted hormone mediating beneficial effects of exercise on metabolism, is supposed to be an ideal therapeutic target for metabolic disorders such as obesity and diabetes. Here, we investigated the potential effects of metformin and glibenclamide, two antidiabetic medicines, on irisin release in mouse. METHODS: Wild-type and diabetic obese db/db mice were administrated with metformin and glibenclamide for 2 weeks, and cultured C2C12 myotubes were treated by metformin. Expression of irisin precursor FNDC5 was measured and blood irisin concentration was detected. AMP-activated protein kinase (AMPK) was blocked by chemical inhibitor compound C or knocking down with specific siRNA. RESULTS: The mRNA and protein expression of FNDC5 in skeletal muscle and blood irisin concentrations were lower in diabetic db/db mice than those in wild-type mice. Metformin and glibenclamide decreased blood glucose in db/db mice. Metformin, but not glibenclamide, increased intramuscular FNDC5 mRNA/protein expression and blood irisin levels. Additionally, the reductions of blood glucose and body weight in metformin-treated db/db mice were positively associated with blood irisin concentrations. In C2C12 myotubes, metformin upregulated intracellular FDNC5 mRNA/protein expression and promoted irisin release. Although metformin activated AMPK signalling in skeletal muscle cells, disrupting of AMPK signalling by chemical inhibitor or siRNA-mediated knockdown did not abolish the promoting effect of metformin on irisin release. CONCLUSION: Metformin promotes irisin release from murine skeletal muscle into blood, independently of AMPK pathway activation. Our results suggest that stimulation of irisin may be a novel molecular mechanism of metformin which is widely used for treatment of metabolic disorders.

Cell-penetrating peptide delivery of biologically active oct4 protein into cultured Takifugu rubripes spermary cells.

Continuous cell culture of a puffer fish Takifugu rubripes has been established for efficient delivery of exogenous genes or proteins to cultured fish cells. Transcription factor oct4 was chosen for transduction into cultured fish cells because of its conserved structure and function between fish and mammals. In this work, the T. rubripes oct4 gene was cloned and expressed in Escherichia coli as a recombinant protein by introducing cell-penetrating peptide (CPP) poly-arginine (11R) and 6His-tag at the C-terminus. After purification, recombinant proteins were added to the growth medium and incubated with T. rubripes spermary cells. Recombinant proteins that crossed the cell membrane were detected in the cytoplasm and nucleus by western blot and immunofluorescent observation. The function of transduced oct4 as a transcription factor in fish cells was confirmed by driving green fluorescent protein expression in the pEGFP-1 reporter construct with the conserved specific oct4-binding sequence from mouse Mus musculus. Taken together, 11R can be an efficient CPP in delivering fusion proteins to cultured fish cells.

Marsdenia tenacissima extract sensitizes MG63 cells to doxorubicin-induced apoptosis.

Marsdenia tenacissima extract (MTE) is a new plate-derived biotechnology product that is frequently used, but occasionally reported, in the field of chemotherapy. In this study, we assessed the antitumor activity and related mechanisms of MTE by various biotechnological methods. The survival rates of MG63 osteosarcoma cells treated with MTE and doxorubicin were measured, individually or jointly, and the changes in cellular shape, apoptotic rates, and Fas expression were observed. The results indicated that combination of MTE and doxorubicin up-regulated Fas expression and induced apoptosis. The survival rate of combined application of 50 mg/mL MTE and 1 µg/mL doxorubicin was significantly lower than that of the individual application (P < 0.01). Other biotechnology methods also showed an apoptosis-inducing effect of combined application that was much stronger than individual application. All of these results suggested that MTE may promote the effects of doxorubicin chemotherapy, perhaps related to the up-regulation of Fas expression in tumor cells.

Synergistic increase in the sensitivity of osteosarcoma cells to thermochemotherapy with combination of paclitaxel and etoposide.

Osteosarcoma is a malignant bone tumor which is found most commonly in adolescents and young adults. Local perfusion thermochemotherapy has long been proposed as an alternative strategy for the treatment of osteosarcoma. As a standard anticancer drug, paclitaxel plays a significant role in the treatment of a number of tumors; however, little is known concerning its ability to promote thermochemotherapy. The aim of this study was to evaluate the cytotoxic effects of a combination of paclitaxel and etoposide on an osteosarcoma cell line in the presence of hyperthermia and to investigate the related mechanism. Our study indicated that 1 h after the application of a combination of 10 µg/ml paclitaxel and 5 µg/ml etoposide to OS732 cells at 43˚C, the survival rate of the cells was 14.52% which was significantly lower than when either 10 µg/ml paclitaxel (45.83%) or 5 µg/ml etoposide (43.31%) was applied alone (P<0.01). Moreover, changes in cellular morphology and apoptotic rates indicated that the apoptosis-inducing effect of the combination was much stronger than that of either drug applied individually. Fas expression levels in the OS732 cells were increased by the combination of paclitaxel and etoposide in the presence of hyperthermia. Therefore, paclitaxel enhances the thermochemotherapy of the osteosarcoma cell line and this is primarily accomplished by the upregulation of Fas expression and the induction of apoptosis.

A novel heart-cell line from brown-marbled grouper Epinephelus fuscoguttatus and its susceptibility to iridovirus.

A novel cell line (bmGH) was established from the heart of brown-marbled grouper Epinephelus fuscoguttatus and its viral susceptibility was evaluated. The bmGH cells have been subcultured to passage 65 in Dulbecco's modified eagle medium:Ham's nutrient mixture F-12 (1:1) medium (DMEM/F12) which was further supplemented with foetal bovine serum (FBS), carboxymethyl-chitosan, basic fibroblast growth factor (bFGF) and insulin-like growth factor-I (IGF-I) at 24 degrees C. The heart cells have a fibroblastic morphology and proliferated to confluence 14 days later. The cells grew at a steady rate during subsequent subculture and had a population doubling time of 40.3 h at passage 60. Karyotype analysis showed that these cells exhibited chromosomal aneuploidy with a modal chromosome number of 48. The results of viral susceptibility characterization revealed that cytopathic effects (CPE) of bmGH cells appeared after infection by two iridoviruses, turbot reddish body iridovirus (TRBIV) and lymphocystis disease virus (LCDV). A large number of TRBIV and LCDV particles were also observed in the infected bmGH cells by electron microscope examination. All of these facts indicate that the bmGH cell line established here may serve as a valuable tool for studies of cell-virus interactions and has potential applications in fish virus isolation, propagation and vaccine development.

A study on grafting and characterization of HMDI-modified calcium hydrogenphosphate.

It is known that the organic molecules can provide an effective means to manipulate the surface properties of the biodegradable ceramic. There are two ways to modify the surface of the biodegradable ceramic by organic molecules. The first one is through surface adsorption but organic molecules will easily be washed out in the physiological environment. The second approach is to graft organic molecules through covalent bond to the hydroxyl groups that are available on the surface of the ceramics. Isocyanate group has been reported as a coupling agent for hydroxyapatite and organic molecule. The studies showed that the isocyanate could react with hydroxyl groups of hydroxyapatite and form a covalent bond between isocyanate and hydroxyapatite. In the study, hexamethylene diisocyanate (HMDI) was used as coupling agent and calcium hydrogenphosphate (CaHPO4, CHP) was the candidate ceramic. CHP will react with HMDI at the temperature of 20 degrees C, 30 degrees C, 40 degrees C, 50 degrees C, 60 degrees C, and 70 degrees C for 4h. Dibutyltin dilaurate and hydroquinone were used as catalyst and inhibitor, respectively. The effect of reaction temperature on the grafted yield will be described. The linkage between CHP and HMDI will be characterized by DTA, TGA, FTIR, XRD, and 31P, 13C liquid state NMR. From the results, we successfully modified the surface of CHP with coupling agent of HMDI. The grafted yield of HMDI on CHP was increasing with the reaction temperature. The best temperature for CHP modified by HMDI is around 50 degrees C. The linkage between HMDI and the surface of CHP is a urethane linkage as CHP-O-CO-NH-(CH2)6-N=C=O. After further treatment, the terminal group of CHP treated with HMDI (MCHP) will be converted into a primary amine group as the formula of CHP-O-CO-NH-(CH2)6-NH2. If reaction temperature is 60 degrees C, long extension chain will occur with a urea linkage between the isocyanate groups as the formula of CHP-O-CO-NH-(CH2)6-(NH-CO-NH-(CH2)6)n-NH2. At reaction temperature higher than 60 degrees C, the HMDI will become prepolymerized forms in solution. The prepolymerized forms such as allophanate, biuret, uretidione and urea linkage will turn the solution into gel type mixture, which will lead to low grafted yield of HMDI on CHP. When MCHP prepared at the temperature 20 degrees C, there is no evidence of long extension but the grafted yield is the lowest only 0.9 wt% around.

Preparation and characterization of surface-modified calcium hydrogenphosphate by hexamethylene diisocyanates.

Isocyanate group has been reported as a coupling agent of hydroxyapatite and polymers. The studies showed that the isocyanate would react with hydroxyl groups of hydroxyapatite and form a covalent bond between isocyanate and hydroxyapatite. In the study, hexamethlene diisocyanate (HMDI) was used as coupling agent. Calcium hydrogen-phosphate (CaHPO4, CHP) powders was the candidate ceramic due to higher content of hydroxyl group, which would react with HMDI at the temperature of 30, 40, 50, 60, and 70 degrees C for 4 hours. Dibutyltin dilaurate and hydroquinone were used as catalyst and inhibitor, respectively. The product was analyzed by DTA, TGA, FTIR, XRD, 13C solid state NMR and 31P, 13C liquid state NMR. From the results, we could prove the surface of calcium hydrogen-phosphate has been successfully modified. The largest amount (5.6 wt%) of HMDI could be grafted on the surface of CHP when reacted at 50 degrees C for 4 hours. Some chain extension could be observed and their structure would also be described in the research.

A molecular mechanism for electrical tuning of cochlear hair cells.

Cochlear frequency selectivity in lower vertebrates arises in part from electrical tuning intrinsic to the sensory hair cells. The resonant frequency is determined largely by the gating kinetics of calcium-activated potassium (BK) channels encoded by the slo gene. Alternative splicing of slo from chick cochlea generated kinetically distinct BK channels. Combination with accessory beta subunits slowed the gating kinetics of alpha splice variants but preserved relative differences between them. In situ hybridization showed that the beta subunit is preferentially expressed by low-frequency (apical) hair cells in the avian cochlea. Interaction of beta with alpha splice variants could provide the kinetic range needed for electrical tuning of cochlear hair cells.

CSlo encodes calcium-activated potassium channels in the chick's cochlea.

Large conductance, calcium-activated (BK) potassium channels play a central role in the excitability of cochlear hair cells. In mammalian brains, one class of these channels, termed Slo, is encoded by homologues of the Drosophila 'slowpoke' gene. By homology screening with mouse Sla cDNA, we have isolated a full-length clone (cSlo1) from a chick's cochlear cDNA library, rSlol had greater than 90% identity with mouse Slo at the amino acid level, and was even better matched to a human brain Slo at the amino and carboxy termini. cSlol had none of the additional exons found in splice variants from mammalian brain. The reverse transcriptase polymerase chain reaction (RT-PCR) was used to show expression of cSlal in the microdissected hair cell epithelium basilar papilla. Transient transfection of HIEK 293 cells demonstrated that cSlol encoded a potassium channel whose conductance averaged 224 pS at +60 mV in symmetrical 140 mM K. Macroscopic currents through cSlol channels were blocked by scorpion toxin or tetraethyl ammonium, and were voltage and calcium dependent. cSlol is likely to encode BK-type calcium-activated potassium channels in cochlear hair cells.

[An investigation of post-secondary nursing continuing education].

An investigation was made in 20 hospitals in Nanjing to the abilities of the post-secondary college nursing graduates in 4 aspects: (1) nursing technical practice; (2) the numbers of head nurse employment; (3) nursing teaching; (4) nursing research and academic paper writing. Meanwhile a comparison was made between them and college graduates and baccalaureate graduates. Result showed that they were evidently better than baccalaureate graduates (P < 0.01) in nursing technical practice, head nurse employment, and nursing research and obviously different from college graduates (P < 0.01) in technical practice and nursing research. Post secondary continuing education in nursing, as one of the ways of higher nursing education yet adopted, has been playing an extremely important role in the improvement and development of nursing in China.

A novel difucosylated neutral glycosphingolipid from the eggs of the sea urchin, Hemicentrotus pulcherrimus: I. Purification and structural determination of the glycolipid.

A novel fucose-containing neutral glycosphingolipid (GL-5) was purified from the eggs of the sea urchin, Hemicentrotus pulcherrimus. The chemical structure was determined to be Fuc alpha 1-3GalNAc beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-4Glc beta 1-1Cer by methylation analysis, partial acid hydrolysis, fast atom bombardment mass spectrometry, and proton nuclear magnetic resonance spectroscopy. The unique characteristics of GL-5 are that: the reducing terminal disaccharide portion is not Gal beta 1-4Glc but GlcNAc beta 1-4Glc; it includes a GalNAc beta 1-4GlcNAc sequence and a Fuc-GalNAc linkage; the defucosylated core is a novel trisaccharide chain; and the sugar structure is one of the smallest ever characterized for a difucosylated glycolipid. The major fatty acids were 22:1 and 22h:1, and about 30% of the total acids was 2-hydroxylated. All the long-chain bases were phytosphingosines, of which about 90% was n-t18:0. The similarity of the ceramide moiety to that of glucosylceramide from the same eggs [Kubo, H. et al. (1992) J. Biochem. 111, 726-731] suggests a close biosynthetic relationship between GL-5 and the glucosylceramide.

A novel ceramide trihexoside from the eggs of the sea urchin, Hemicentrotus pulcherrimus.

Glucosylceramide (Glc beta 1-1Cer) and a novel ceramide trihexoside (Gal beta 1-6Gal beta 1-6Glc beta 1-1Cer) were purified from the eggs of the sea urchin, Hemicentrotus pulcherrimus. Their chemical structures were determined by gas-liquid chromatography, methylation analysis, chromic acid oxidation, enzymatic hydrolysis, enzyme-linked immunosorbent assay, fast atom bombardment mass spectrometry, and proton nuclear magnetic resonance spectroscopy. The ceramide trihexoside has a novel carbohydrate structure, and its core structure, Gal beta 1-6Glc, is also novel. The ceramide moieties of these glycolipids are almost identical. Two fatty acids, 22:1 and 22h:1, constitute more than 80% of the total acids. Long-chain bases are all phytosphingosine, approximately 90% of which is n-t18:0. The finding of melibiosylceramide (Gal alpha 1-6Glc beta 1-1Cer) from the eggs of another sea urchin species [Kubo, H. et al. (1988) J. Biochem. 104, 755-760] and the present finding of the novel ceramide trihexoside suggest that there are a variety of unique sugar structures in sea urchin glycosphingolipids.

[Synthesis and analgesic action of 6,7-methylenedioxy-1(2H,4H)-acridone derivatives].

Thirteen derivatives of 6,7-methylenedioxy-1 (2H, 4H)-acridone were prepared. The structures of all the compounds synthesized were characterized by elemental analysis, IR and 1H NMR spectra. Compounds IIa, IIb, IId, IIe, IIf increased significantly the pain threshold using the hot-plate method.