NAD-Independent L-Lactate Dehydrogenase Is Required for L-Lactate Utilization in Pseudomonas stutzeri SDM

BACKGROUND: Various Pseudomonas strains can use L-lactate as their sole carbon source for growth. However, the L-lactate-utilizing enzymes in Pseudomonas have never been identified and further studied. METHODOLOGY/PRINCIPAL FINDINGS: An NAD-independent L-lactate dehydrogenase (L-iLDH) was purified from the membrane fraction of Pseudomonas stutzeri SDM. The enzyme catalyzes the oxidation of L-lactate to pyruvate by using FMN as cofactor. After cloning its encoding gene (lldD), L-iLDH was successfully expressed, purified from a recombinant Escherichia coli strain, and characterized. An lldD mutant of P. stutzeri SDM was constructed by gene knockout technology. This mutant was unable to grow on L-lactate, but retained the ability to grow on pyruvate. CONCLUSIONS/SIGNIFICANCE: It is proposed that L-iLDH plays an indispensable function in Pseudomonas L-lactate utilization by catalyzing the conversion of L-lactate into pyruvate

Comparison of bioimpedance equations and dual-energy X-ray for assessment of fat free mass in a Chinese dialysis population

AbstractPurpose Bioelectrical impedance analysis (BIA) is simple, noninvasive, inexpensive and frequently used for estimating fat free mass (FFM). The aims of this study were to evaluate the applicability of different BIA equations on FFM in Chinese subjects, and to compare the difference in hemodialysis and peritoneal dialysis patients with healthy controls respectively.Methods Dialysis patients and healthy adults were enrolled in this study, and the subjects were matched by age, gender, and the minimum sample size in each group was calculated using PASS. FFM estimated by BIA was calculated using equations of Kyle, Sun SS and Segal, and TBW/0.73. Dual-energy X-ray absorptiometry (DXA) method was set as reference method. Pearson’s correlation and Bland-Altman analysis were used to test the validity of the BIA equations.Results 50 hemodialysis (HD) patients, 52 peritoneal dialysis (PD) patients and 30 healthy adults aged 22–67 y were included in this study. Age, height, weight, BMI and gender did not differ significantly among HD, PD patients, and healthy controls (p > 0.05), but BIA parameters were quite different (p＜0.01). Bland-Altman analysis showed that in healthy volunteers, all equations showed good agreement with DXA measured. For dialysis patients, the FFM predictions of different equations showed differences between HD and PD patients, and the equations seemed more applicable for HD patients.Conclusion The equations developed by healthy subjects might be not appropriate for dialysis patients, especially peritoneal dialysis patients. It is recommended to develop a specific BIA equation from dialysis population

Phenotypic and molecular characterization of multidrug resistant Klebsiella pneumoniae isolated from a university teaching hospital, China.

The multidrug-resistant rate of Klebsiella pneumoniae has risen rapidly worldwide. To better understand the multidrug resistance situation and molecular characterization of Klebsiella pneumoniae, a total of 153 Klebsiella pneumoniae isolates were collected, and drug susceptibility test was performed to detect its susceptibility patterns to 13 kinds of antibiotics. Phenotypic tests for carbapenemases ESBLs and AmpC enzyme-producing strains were performed to detect the resistance phenotype of the isolates. Then PCR amplification and sequencing analysis were performed for the drug resistance determinants. The results showed that 63 strains harbored bla CTX-M gene, and 14 strains harbored bla DHA gene. Moreover, there were 5 strains carrying bla KPC gene, among which 4 strains carried bla CTX-M, bla DHA and bla KPC genes, and these 4 strains were also resistant to imipenem. Our data indicated that drug-resistant Klebsiella pneumoniae were highly prevalent in the hospital. Thus it is warranted that surveillance of epidemiology of those resistant isolates should be a cause for concern, and appropriate drugs should be chosen

Diagnostic utility of neutrophil CD64 as a marker for early-onset sepsis in preterm neonates.

Neutrophil CD64 has been proposed as an early marker of sepsis. This study aims to evaluate the diagnostic utility of neutrophil CD64 for identification of early-onset sepsis in preterm neonates.The prospective study was conducted in a neonatal intensive care unit between November 2010 and June 2011. Preterm neonates in whom infection was suspected when they were <12 hours of age were enrolled. Complete blood count with differential, blood culture, neutrophil CD11b and CD64 measurement were performed. Receiver operating characteristic curve analysis was performed to evaluate the performance of neutrophil CD64 as biomarker of sepsis.A total of 158 preterm neonates was enrolled, 88 of whom were suspected infection. The suspected sepsis group was of lesser gestational age (P<0.001) and lower birth weight (P<0.001), compared with controls. The hematologic profiles of the suspected sepsis group were characterized by higher white blood cell count, neutrophil counts and C-reactive protein. The suspected sepsis neonates had significantly higher neutrophil CD64 expression compared with controls. Neutrophil CD64 had an area value under the curve of 0.869 with an optimal cutoff values of 1010 phycoerythrin molecules bound/cell and it had a high sensitivity (81.82%) and negative predictive value (77.4%). The level of neutrophil CD64 was independent of antibiotic therapy within 24 hours after the onset of sepsis in preterm neonates.Neutrophil CD64 is a highly sensitive marker for suspected early-onset sepsis in preterm neonates. Our study suggests that neutrophil CD64 may be incorporated as a valuable marker to diagnose infection

Two Novel Colorimetric Probes (5-HMBA-FH and 3-HMBA-FH) Based on Fluorescein for Copper(II) ion Detection

Two novel isomeric colorimetric probes are established for simultaneous determination of copper ions using 2-Hydroxy-5-methoxybenzaldehyde fluorescein hydrazone (5-HMBA-FH) and 2-Hydroxy-3-methoxybenzaldehyde fluorescein hydrazone (3-HMBA-FH). They are synthesized by reacting fluorescein hydrazide with 2-Hydroxy-5-methoxybenzaldehyde and 2-Hydroxy-3-methoxybenzaldehyde, respectively, and then characterized by 1H-NMR, 13C-NMR and Infrared spectrum. In addition of copper ions to the solutions of two novel colorimetric probes can generate the obviously peaks at 498 nm in UV-vis absorption spectra along with a rapid color change from colorless to dark yellow. The detection limits of the method for Cu2+ ion were 3.442 Ă 10-6 mol/L and 3.682 Ă 10-6 mol/L separately, for 5-HMBA-FH and 3-HMBA-FH. The additions of other metal ions hardly affect the copper ions determination. The proposed method was successfully applied to the analysis of Cu2+ ions in various samples. This method possessing high sensitivity, simplicity and minimized interfere will provide a great advantage in detecting copper ions in the environmental, food, medical applications.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Silencing Notch4 promotes tumorigenesis and inhibits metastasis of triple-negative breast cancer via Nanog and Cdc42

Abstract Elucidation of individual Notch protein biology in specific cancer is crucial to develop safe, effective, and tumor-selective Notch-targeting therapeutic reagents for clinical use [1]. Here, we explored the Notch4 function in triple-negative breast cancer (TNBC). We found that silencing Notch4 enhanced tumorigenic ability in TNBC cells via upregulating Nanog expression, a pluripotency factor of embryonic stem cells. Intriguingly, silencing Notch4 in TNBC cells suppressed metastasis via downregulating Cdc42 expression, a key molecular for cell polarity formation. Notably, downregulation of Cdc42 expression affected Vimentin distribution, but not Vimentin expression to inhibit EMT shift. Collectively, our results show that silencing Notch4 enhances tumorigenesis and inhibits metastasis in TNBC, indicating that targeting Notch4 may not be a potential strategy for drug discovery in TNBC

Tumor microenvironment/NIR-responsive carbon monoxide delivery with hollow mesoporous CuS nanoparticles for MR imaging guided synergistic therapy

The synthesis of a novel versatile nanomedicine platform integrating multiple imaging and therapeutic functions has always been a great challenge for efficient cancer diagnosis and therapy. Herein, in this study, a novel versatile carbon monoxide (CO) delivery nanoplatform was constructed with hollow mesoporous CuS NPs carrying manganese carbonyl (MnCO) to realize MR imaging-guided PTT and CO combined anticancer therapy. The MnCO@CuS nanoplatform revealed superior properties in colloidal stability, photothermal conversion, H2O2/NIR-stimulated CO release and tumoral accumulation. More importantly, the enriched H2O2 in the tumor microenvironment (TME) triggered MnCO to release CO in situ, and this process was further strengthened by the NIR irradiation. Subsequently, the intermediate products MnOx was degraded into Mn2+ by the mild acidic tumor microenvironment to enable T1-weighted MR imaging. Simultaneously, the in situ-released CO combined with NIR irradiation exhibited strongest inhibition to the growth of MV3 tumor in vitro and in vivo. Moreover, the multifunctional nanoplatform also exhibited low toxicity and good biocompatibility in vitro and in vivo. Hence, these results suggested the MnCO@CuS nanoplatform possessed significant potential in realizing TME/NIR stimulated CO/Mn2+ generation and photothermal conversion for MR imaging-guided synergistic PTT and CO anticancer therapy

Boxplot distribution of the nCD64 in suspected group and control group.

<p>The <i>box</i> shows the 25^th–75^th percentiles, whereas the <i>whiskers</i> indicate the 10^th and 90^th percentiles. T1, time at onset of sepsis (<12 hours after birth); T2, 12 hour after the onset of sepsis; T3, 72 hour after the onset of sepsis.</p