Phage transcriptional regulator X (PtrX)-mediated augmentation of toxin production and virulence in Clostridioides difficile strain R20291.

Clostridioides difficile is a Gram-positive, anaerobic, and spore-forming bacterial member of the human gut microbiome. The primary virulence factors of C. difficile are toxin A and toxin B. These toxins damage the cell cytoskeleton and cause various diseases, from diarrhea to severe pseudomembranous colitis. Evidence suggests that bacteriophages can regulate the expression of the pathogenicity locus (PaLoc) genes of C. difficile. We previously demonstrated that the genome of the C. difficile RT027 strain NCKUH-21 contains a prophage-like DNA sequence, which was found to be markedly similar to that of the φCD38-2 phage. In the present study, we investigated the mechanisms underlying the φNCKUH-21-mediated regulation of the pathogenicity and the PaLoc genes expression in the lysogenized C. difficile strain R20291. The carriage of φNCKUH-21 in R20291 cells substantially enhanced toxin production, bacterial motility, biofilm formation, and spore germination in vitro. Subsequent mouse studies revealed that the lysogenized R20291 strain caused a more severe infection than the wild-type strain. We screened three φNCKUH-21 genes encoding DNA-binding proteins to check their effects on PaLoc genes expression. The overexpression of NCKUH-21_03890, annotated as a transcriptional regulator (phage transcriptional regulator X, PtrX), considerably enhanced toxin production, biofilm formation, and bacterial motility of R20291. Transcriptome analysis further confirmed that the overexpression of ptrX led to the upregulation of the expression of toxin genes, flagellar genes, and csrA. In the ptrX-overexpressing R20291 strain, PtrX influenced the expression of flagellar genes and the sigma factor gene sigD, possibly through an increased flagellar phase ON configuration ratio.

Clinical and pathological findings of SARS-CoV-2 infection and concurrent IgA nephropathy: a case report.

BACKGROUND: Since the Coronavirus Disease 2019 (COVID-19) outbreak, there is accumulating data on the clinical characteristics, treatment strategies and prognosis of COVID-19 in patients with concurrent renal disease. Postmortem investigations reveal renal involvement in COVID-19, and most recently, several biopsy researches reveal that acute tubular injury, as well as glomerular nephropathy such as collapsing glomerulopathy were common histological findings. However, to our best knowledge, there is limited data regarding IgA nephropathy in the setting of COVID-19. CASE PRESENTATION: In the present case, we report a 65-year old Chinese woman who presented with dark-colored urine, worsening proteinuria and decreased renal function after COVID-19 infection. She received a renal biopsy during COVID-19 infection. The renal biopsy revealed IgA nephropathy without any evidence for SARS-Cov-2. The findings suggest that the renal abnormalities were a consequence of exacerbation of this patient's underlying glomerular disease after COVID-19 infection. After a regimen of 3-day course of glucocorticoid and angiotensin II receptor blocker therapy, the patient recovered and remained stable upon follow-up. CONCLUSIONS: It is important to consider the underlying glomerular disease exacerbation as well as virus induced injury when dealing with renal abnormalities in patients with COVID-19. A kidney biopsy may be indicated to exclude a rapidly progressive glomerular disease.

Viral and Bacterial Etiology of Acute Diarrhea among Children under 5 Years of Age in Wuhan, China.

BACKGROUND: Acute diarrhea remains the serious problem in developing countries, especially among children under 5 years of age. Currently, only two or three common diarrhea pathogens were screened at most hospitals in China. The aim of this study was to provide a wide variety of diarrhea pathogens and their antimicrobial resistance patterns in children under 5 years of age. METHODS: Totally 381 stool samples collected from Tongji Hospital between July 1, 2014 and June 30, 2015 were tested by culture and/or polymerase chain reaction for eight kinds of bacteria and five kinds of viruses. An antimicrobial sensitivity test was performed using dilution method recommended by the Clinical and Laboratory Standards Institute. RESULTS: Viral infections were mainly identified in infants (0-11 months), whereas bacterial infections were more prevalent in the age of 24-59 months. About 69.8% of samples were positive for at least one pathogen, 51.7% of samples were virus positive, followed by bacteria positive cases (19.4%), and 12.6% of cases displayed co-infections with two viruses or a virus and a bacterium. Rotavirus was the most prevalent pathogen, followed closely by norovirus, while Salmonella was the most commonly isolated bacteria, followed by diarrheagenic Escherichia coli (DEC) and Campylobacter. More than 40% of Salmonella spp. and DEC isolates were resistant to first-line antibiotics (ampicillin, trimethoprim-sulfamethoxazole, and tetracycline). Around 10% of Salmonella spp. isolates were resistant to ceftriaxone and ciprofloxacin simultaneously. Campylobacter spp. displayed high resistance to ciprofloxacin but kept low resistance to azithromycin and doxycycline. CONCLUSIONS: The etiology of acute diarrhea varies in children of different age groups. The high frequency of infection with viruses suggests the urgent demand for new viral vaccine development. Proper use of antibiotics in the treatment of acute diarrhea is crucial due to the high level of antibiotic resistance.

Visual and efficient immunosensor technique for advancing biomedical applications of quantum dots on Salmonella detection and isolation.

It is a great challenge in nanotechnology for fluorescent nanobioprobes to be applied to visually detect and directly isolate pathogens in situ. A novel and visual immunosensor technique for efficient detection and isolation of Salmonella was established here by applying fluorescent nanobioprobes on a specially-designed cellulose-based swab (a solid-phase enrichment system). The selective and chromogenic medium used on this swab can achieve the ultrasensitive amplification of target bacteria and form chromogenic colonies in situ based on a simple biochemical reaction. More importantly, because this swab can serve as an attachment site for the targeted pathogens to immobilize and immunologically capture nanobioprobes, our mAb-conjugated QD bioprobes were successfully applied on the solid-phase enrichment system to capture the fluorescence of targeted colonies under a designed excitation light instrument based on blue light-emitting diodes combined with stereomicroscopy or laser scanning confocal microscopy. Compared with the traditional methods using 4-7 days to isolate Salmonella from the bacterial mixture, this method took only 2 days to do this, and the process of initial screening and preliminary diagnosis can be completed in only one and a half days. Furthermore, the limit of detection can reach as low as 10(1) cells per mL Salmonella on the background of 10(5) cells per mL non-Salmonella (Escherichia coli, Proteus mirabilis or Citrobacter freundii, respectively) in experimental samples, and even in human anal ones. The visual and efficient immunosensor technique may be proved to be a favorable alternative for screening and isolating Salmonella in a large number of samples related to public health surveillance.

Sesamin enhances nitric oxide bioactivity in aortas of spontaneously hypertensive rats.

BACKGROUND: The blood pressure lowering effect of sesamin has been demonstrated to be associated with the increase in vascular nitric oxide (NO) biological activity by our previous studies and others. The present study was designed to explore the underlying mechanisms involved in the effect of sesamin on aortic NO bioactivity in spontaneously hypertensive rats (SHRs). METHODS: Sesamin was orally administered for 8 consecutive weeks in SHRs. Systolic blood pressure (SBP) was measured using the tail-cuff method. The aortas were isolated and in vitro vascular reactivity studies were performed. Superoxide anion production in carotid arteries was assessed by dihydroethidium fluorescence staining. The protein expression of endothelial nitric oxide synthase (eNOS), phosphorylated eNOS (P-eNOS), dihydrofolate reductase (DHFR), nicotinamide adenine dinucleotide phosphate oxidase subunit p47phox, and copper, zinc superoxide dismutase (Cu/Zn-SOD) in aortas was detected by Western blotting. The dimeric form of eNOS in aortas was determined by low-temperature sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Aortic level of nitrotyrosine and activities of antioxidant enzymes, namely, total SOD (T-SOD), glutathione peroxidase (GPx) and catalase were also detected. RESULTS: In SHRs, sesamin treatment reduced SBP, improved vascular relaxation induced by acetylcholine and enhanced aortic NO bioactivity. Sesamin treatment enhanced NO biosynthesis in SHR aortas was due to upregulated P-eNOS and suppressed eNOS uncoupling, and the latter effect might be attributed to decreased nitrotyrosine and upregulated DHFR. Sesamin also reduced the NO oxidative inactivation and decreased the superoxide anion production through downregulation of p47(phox) and amelioration of eNOS uncoupling. In addition, sesamin treatment did not alter the levels of GPx and catalase activity but obviously reduced the compensatory elevated T-SOD activity and Cu/Zn-SOD protein expression. CONCLUSION: Chronic treatment with sesamin could reduce hypertension and improve endothelial dysfunction through enhancement of NO bioactivity in SHR aortas.

Reconstruction of Digital Skin Defects with the Free Wrist Crease Flap.

BACKGROUND: Soft-tissue digital defects frequently need to be covered by a flap rather than a skin graft. In hand surgery, functional preservation and aesthetic appearance are often as important as procedural efficacy. OBJECTIVE: We present our clinical experience with reconstruction of digital skin defects with the free wrist crease flap. METHODS: From January 2012 to September 2013, 14 digits of 14 patients (10 males, 4 females) were included for evaluation. The procedure was performed with brachial plexus block anesthesia. The superficial palmar branch of the radial artery, a subcutaneous superficial vein, and the palmar cutaneous branch of the median nerve were included in the free wrist crease flap. The flaps were used to reconstruct the skin defect of injured digits through microvascular anastomosis, and donor sites were closed primarily. RESULTS: Postoperative follow-up time ranged from 3 to 25 months. All digital deformities were corrected, all flaps survived completely without ischemia, and none were aesthetically bulky. The area of free wrist crease flaps ranged from 2.5 to 5.0 cm by 2.0 to 3.1 cm. Slight wound infections appeared in two cases. Venous crisis occurred in one case, but it was successfully addressed after vascular exploration and reanastomosis. Sensation determined by static two-point discrimination measured in these flaps 2 months postsurgery was "good" at a mean 9.7 ± 2.1 mm (range, 6-14 mm). The mean motion range of the distal interphalangeal joint and proximal interphalangeal joint was 23.4 ± 6.9 degrees (0-42 degrees) and 75.8 ± 22.1 degrees (0-98 degrees) preoperatively. The mean motion range of the distal interphalangeal joint recovered to 40.3 ± 5.7 degrees (36-42 degrees), and that of the proximal interphalangeal joint was 90.3 ± 15.3 degrees (85-98 degrees) postoperatively. Both joints reached normal motion angle and difference was statistically significant preoperatively and postoperatively (p < 0.05). The mean disabilities of arm and shoulder (DASH) score was 6.8 ± 3.4 (0-15), and there was statistically significant difference when compared with the preoperative score of 13.5 ± 4.3 (3-19) (p < 0.05). CONCLUSION: We found the free wrist crease flap to be an ideal solution for reconstruction of skin defects of digits.

Fluorescence turn-on chemodosimeter for rapid detection of mercury (II) ions in aqueous solution and blood from mice with toxicosis.

The heavy metal mercury (Hg) is a threat to the health of people and wildlife in many environments. Among various chemical forms, Hg(2+) salts are usually more toxic than their counterparts because of their greater solubility in water; thus, they are more readily absorbed from the gastrointestinal tract into circulation. Therefore, new chemical receptors for detecting Hg(2+) ions in circulation are needed. In this study, we developed a rhodamine-based turn-on fluorescence probe to monitor Hg(2+) in aqueous solution and in blood of mice with toxicosis. The chemodosimeter responds to Hg(2+) ions stoichiometrically, rapidly, and irreversibly at room temperature as a result of a chemical reaction that produces strongly fluorescent oxadiazole. The new fluorescent probe shows good fluorescence response, with high sensitivity and selectivity, toward Hg(2+) ions in aqueous solution and in blood from mice with toxicosis and facilitates the naked-eye detection of Hg(2+) ions.

Novel ferrocenyl derivatives exert anti-cancer effect in human lung cancer cells in vitro via inducing G1-phase arrest and senescence.

AIM: To investigate the effects of 7 novel 1-ferrocenyl-2-(5-phenyl-1H-1,2,4-triazol-3-ylthio) ethanone derivatives on human lung cancer cells in vitro and to determine the mechanisms of action. METHODS: A549 human lung cancer cells were examined. Cell viability was analyzed with MTT assay. Cell apoptosis and senescence were examined using Hoechst 33258 and senescence-associated-ß-galactosidase (SA-ß-gal) staining, respectively. LDH release was measured using a detection kit. Cell cycle was analyzed using a flow cytometer. Intracellular ROS level was measured with the 2',7'-dichlorodihydrofluorescein probe. Phosphorylation of p38 was determined using Western blot. RESULTS: Compounds 5b, 5d, and 5e (40 and 80 µmol/L) caused significant decrease of A549 cell viability, while other 4 compounds had no effect on the cells. Compounds 5b, 5d, and 5e (80 µmol/L) induced G1-phase arrest (increased the G1 population by 22.6%, 24.23%, and 26.53%, respectively), and markedly increased SA-ß-gal-positive cells. However, the compounds did not cause nuclear DNA fragmentation and chromatin condensation in A549 cells. Nor did they affect the release of LDH from the cells. The compounds significantly elevated the intracellular ROS level, decreased the mitochondrial membrane potential, and increased p38 phosphorylation in the cells. In the presence of the antioxidant and free radical scavenger N-acetyl-L-cysteine (10 mmol/L), above effects of compounds 5b, 5d, and 5e were abolished. CONCLUSION: The compounds 5b, 5d, and 5e cause neither apoptosis nor necrosis of A549 cells, but exert anti-cancer effect via inducing G1-phase arrest and senescence through ROS/p38 MAP-kinase pathway.

Precursor B-cell lymphoblastic leukemia of the arm mimicking neurogenic tumor: case report.

Precursor B-cell lymphoblastic lymphoma (PBLL) is an infrequent subtype of lymphoblastic lymphoma (LBL) that commonly affected site for the diagnosis is the skin, followed by the head and neck. In this report, we presented a special case of PBLL located at the left arm and detected with magnetic resonance imaging (MRI) and ultrasonography (US). This kind of PBLL is similar to a peripheral nerve tumor in clinical and radiographic manifestation.

A new fluorescent and colorimetric probe for Cu2+ in live cells.

Based on a change in structure between spirocyclic (non-fluorescent) and ring-open (fluorescent) forms of rhodamine-based dyes, a new fluorescent and colorimetric Cu(2+) probe was designed and synthesized. Upon treatment with Cu(2+), the weakly fluorescent probe exhibited a strong fluorescence response with high selectivity. In addition, the turn-on fluorescent probe upon the addition of Cu(2+) was applied in live cell imaging.

A rhodamine chromene-based turn-on fluorescence probe for selectively imaging Cu²+ in living cell.

We describe the development of a rhodamine chromene-based turn-on fluorescence probe to monitor the intracellular Cu(2+) level in living cells. The new fluorescent probe with a chlorine group in chromene moiety exhibits good membrane-permeable property than previous reported because the predicted lipophilicity of present probe 4 is stronger than that of methoxyl substituted probe in our previous work (CLogP of 4: 8.313, CLogP of methoxyl substituted probe: 7.706), and a fluorescence response toward Cu(2+) under physiological conditions with high sensitivity and selectivity, and facilitates naked-eye detection of Cu(2+). The fluorescence intensity was remarkably increased upon the addition of Cu(2+) within 1 or 2 min, while the other sixteen metal ions caused no significant effect.

Synthesis, crystal structure and living cell imaging of a Cu(2+)-specific molecular probe.

We report the development of a rhodamine chromene-based fluorescence probe to monitor the intracellular Cu(2+) level in living cells. The new fluorescent probe exhibits a fluorescence response towards Cu(2+) under physiological conditions with high sensitivity and selectivity, and facilitates the naked-eye detection of Cu(2+). The fluorescence intensity was significantly increased by about 40-fold with 10 equiv. of added Cu(2+).

Synthesis, X-ray crystal structures and optical properties of novel substituted pyrazoly 1,3,4-oxadiazole derivatives.

Novel pyrazoly 1,3,4-oxadiazole derivatives were synthesized and characterized by (1)H NMR, IR, HRMS and X-ray diffraction analysis. UV-vis absorption and fluorescence properties of these compounds in different solutions showed that the maximum absorption wavelength was not significantly changed in different solvents; however, maximal emission wavelength was red-shifted with the increase of solvent polarity. Absorption λ(max) and emission λ(max) was less correlated with substituent groups on aryl rings.

The synthesis, X-ray crystal structure and optical properties of novel 5-aryl-3-ferrocenyl-1-pyridazinyl-pyrazoline derivatives.

A series of novel 5-aryl-3-ferrocenyl-1-pyridazinyl pyrazoline derivatives was synthesized by the reaction of ferrocenyl chalcone and 3-chloro-6-hydrazinylpyridazine in 10-65% yields. The compounds were characterized using IR, (1)H NMR, HRMS spectroscopic techniques and representative compounds 3c and 4c were assigned based on the X-ray crystallographic structure. The absorption and fluorescence characteristics of the compounds were investigated in chloroform, tetrahydrofuran and acetonitrile, respectively. The results showed that the absorption maxima of the compounds varied from 323 to 327 nm depending on the groups bonded to benzene and pyridazine ring. The maximum emission spectra of compounds in CHCl(3) were dependent on groups in pyridazine ring in which a strong donating-electron group such as propoxyl group on pyridazine ring in N-1 position of pyrazoline made the emission wavelength of 4a-4e small red shifte than that of compounds 3a-3e with chlorine group. The intensity of absorption and fluorescence was also correlated with substituent on aryl ring in C-5 position of pyrazoline. In addition, the absorption spectra of these compounds changed very little, but the fluorescence spectra had much change with increasing solvent polarity.

The synthesis, X-ray crystal structure and optical properties of novel 1-ferrocenyl-2-(3-phenyl-1H-1,2,4-triazol-5-ylthio)ethanone derivatives.

A series of novel 1-ferrocenyl-2-(3-phenyl-1H-1,2,4-triazol-5-ylthio)ethanone derivatives was synthesized by the reaction of 3-substituted-1H-1,2,4-triazole-5-thiol and chloroacetyl ferrocene in the presence of sodium hydride and potassium iodide at reflux. The structures of the new compounds were determined by IR and (1)H NMR spectroscopy and HRMS. The structure of compound 5c was established by X-ray crystallography. UV-vis absorption and fluorescence spectra were recorded in ethanol and dichloromethane. The results showed that compounds 5a-g display similar absorptions ranging from 300 to 500nm and maximal emission bands are about 566nm. The intensity of fluorescence and maximal emission bands are dependent on the groups bonded to triazole rings.

2-[5-(1,3-Benzodioxol-5-yl)-3-ferrocenyl-4,5-dihydro-1H-pyrazol-1-yl]-4-phenyl-1,3-thia-zole.

In the title compound, [Fe(C(5)H(5))(C(24)H(18)N(3)O(2)S)], the pyrazoline ring adopts a twist conformation. The thia-zole ring forms dihedral angles of 83.7 (2) and 34.4 (2)° with the benzene ring of the benzodioxole ring and the fused phenyl ring, respectively. The mol-ecular conformation is stabilized by an intra-molecular C-H⋯π inter-action. The crystal packing features inter-molecular C-H⋯N, C-H⋯O hydrogen bonds and weak C-H⋯π inter-actions.

Synthesis and discovery of pyrazole-5-carbohydrazide N-glycosides as inducer of autophagy in A549 lung cancer cells.

A series of novel 3-aryl-1-arylmethyl-1H-pyrazole-5-carbohydrazide N-beta-glycoside derivatives was synthesized by the reaction of substituted 1H-pyrazole-5-carbohydrazide with d-sugar and the effects of all the compounds on A549 cell growth were investigated. The results showed that all compounds had inhibitory effects on the growth of A549 lung cancer cells and compound 3d possessed the highest growth inhibitory effect and induced autophagy of A549 lung cancer cells.

Synthesis of novel ribavirin hydrazone derivatives and anti-proliferative activity against A549 lung cancer cells.

A series of novel ribavirin hydrazone derivatives were synthesized by the reaction of ribavirin hydrazone with benzaldehyde or acetophenone derivatives. The structures of the compounds were determined by IR, (1)H NMR, and HRESIMS. Preliminary biological evaluation showed that one compound (7h) inhibits the growth of A549 cells at 20microM.

[Study on the influence of the configuration of porcine aortic root on the stentless valve design].

OBJECTIVE: To provide the reference for the stentless aortic valve design with the study of the inner configuration of porcine aortic root. METHODS: The orifice areas of porcine aortic root at 4 levels (OA1 to 4), the average area of leaflets (Sa), the area analogue of leaflets (AA, AA = 1/2PH), the average area analogue of leaflets (AAa), the value PH of the left, right, non coronary leaflets (PHl, PHr, PHn) and the sums of PHs of the left and non-coronary leaflets (PHln) in the fresh and glutaraldehyde and epichlorohydrin-treated porcine aortic valves (20 respectively) were measured and calculated. The linear correlation and regression analysis by SPSS 12.0 was used to analyze the correlation between Sa and AAa, OA and Sa, OA and AAa, PHl, PHr and PHn, PHln and PHr in both groups. RESULTS: The coefficient correlation between Sa and AAa in fresh and treated groups were 0.886 and 0.872 respectively (P < 0.05). The coefficient correlation between OA1 to 4 and AAa were 0.810, 0.851, 0.900, and 0.815 respectively in fresh group (P < 0.05), and were 0.852, 0.888, 0.836, and 0.817 respectively in treated group (P < 0.05). This showed that the degree of correlation between the average area analogue of leaflets and the average area of leaflets, the orifice areas of aortic root were relatively large. Additionally, the equation of linear regression existed between PHln and PHr in treated group as follows: PHr = -1.665 + 0.688 PHln (r = 0.907, P < 0.05), thereby PHr could be predicted by PHln. CONCLUSION: The value of PH of leaflets could represent the spatial configuration of the aortic root, which provided a referred index for the stentless bioprostheses design.

[Research on application of modified polyethylene glycol hydrogels in the construction of tissue engineered heart valve].

OBJECTIVE: To explore the effect of the polyethylene glycol (PEG)-hydrogels to enhance the seeding-cells adhesion to the biomaterial scaffolds. METHODS: Sixteen porcine aortic valves were decellularized with Triton X-100 and trypsin, then divided into A and B group, eight in each group. Group A: the donor goat's autologous bone marrow mesenchymal stem cells (BMSCs) Selected as the seeding-cells were encapsulated into the modified PEG-hydrogels to complete the process of the cells attaching to the acellular porcine aortic valves. Non-PEG but reservation of BMSCs was modified in Group B. After static culture for 7 d, the mono semilunar tissue engineering heart valve (TEHV) were implanted respectively into each donor goat's abdominal aortas. Gross and histology examination, ultrasonic scanning, electron microscopy observation and biomechanics detection were performed at 16 weeks after operation. The 8 native goat aortic valves from the donor goats were selected at the same time as control group (Group C). RESULTS: There were much more improvements compared Group A to Group B (P < 0.05) in tensile strength [(12.9 +/- 1.3) MPa vs. (8.8 +/- 0.4) MPa], ratio of re-endothelial (84.6% vs. 14.8%) and mural thrombosis (0/8 vs. 8/8). The data illustrated the critical importance of BMSCs differentiation to endothelial and myofibroblast for remodeling into native tissue in microenvironment in vivo. CONCLUSIONS: It is feasible to reconstruct TEHV efficiently by combining modified PEG-hydrogels with acellular biomaterial scaffold and autologous MSCs cells. It can improve the integration of the seeding-cells and scaffold. It can also protect the growth and differentiation of the BMSCs in the systemic circulation effectively.