The Effect of Gap Distance between a Pin and Water Surface on the Inactivation of Escherichia coli Using a Pin-to-Water Plasma.

Atmospheric plasmas have been applied for the inactivation of microorganisms. Industrials demand to investigate the relation of the key reactive species induced by plasmas and the operating parameters including boundary conditions in order to control plasma treatment processes. In this study, we investigated the effect of gap distance between a pin-electrode and water surface on inactivation efficacy. When the gap distance decreased from 5 mm to 1 mm, the reduction of Escherichia coli (E. coli) was increased to more than 4 log CFU/mL. The reactive oxygen species measured optically and spectrophotometrically were influenced by gap distance. The results from electron spin resonance (ESR) analysis showed that the pin-to-water plasma generated hydroxyl radical (OH•) and singlet oxygen (1O2) in the water and superoxide radical (O2-•) served as a precursor of OH•. The inactivation of E. coli was significantly alleviated by sodium azide (1O2 scavenger), indicating that 1O2 contributes the most to bacterial inactivation. These findings provide a potentially effective strategy for bacterial inactivation using a pin-to-water plasma.

Sequential treatment of hydrogen peroxide, vacuum packaging, and dry heat for inactivating Salmonella Typhimurium on alfalfa seeds without detrimental effect on seeds viability.

The aim of this study was to inactivate Salmonella Typhimurium loaded onto alfalfa seeds with sequential treatment of hydrogen peroxide, drying, vacuum packaging, and dry heat. Also, we verified the effect of vacuum packaging in dry heat treatment. Populations of Salmonella on alfalfa seeds after sequential treatment were not detected after 8 or 3 h of dry heat treatment at 70 or 73 °C. Salmonella populations including injured cells were also reduced to below the detection limit after 8 or 4 h of dry heat treatment. The germination rate of alfalfa seeds subjected to the harshest treatment was not significantly different (P > 0.05) from that of untreated seeds. Vacuum packaging is conducive to preserving the moisture content of alfalfa seed and improving the efficiency of dry heat treatment. This study suggests that sequential treatment is recommended and applicable for decontaminating alfalfa seeds for sprout production.

Inactivation of Escherichia coli and Staphylococcus aureus on contaminated perilla leaves by Dielectric Barrier Discharge (DBD) plasma treatment.

This study focused on sterilization methods for the reduction of microorganisms on perilla leaves by cylinder type Dielectric Barrier Discharge (DBD) plasma with underwater bubbler treatment. S. aureus and E. coli in a suspension were reduced to less than 3.4 and 0.5 log CFU/ml after the plasma treatment for 3 min, respectively. On the perilla leaves, they were also reduced to 4.8 and 1.6 log CFU/ml after the plasma treatment, respectively. The S. aureus and E. coli bacterial cell wall was damaged by the plasma treatment evident by scanning electron microscopic analysis. The observed infrared bands of the FTIR spectra demonstrated changes in protein, lipid, polysaccharide, polyphosphate group and other carbohydrate functionalities of plasma treated bacteria and untreated bacterial cell membranes. The degradation of the constituent bonds of the bacterial cell membrane by RONS generated from plasma destroys the DNA, RNA, and proteins within the cell, and may eventually cause cell death. In this study, H2O2 (13.68 µM) and NO3 (138 µM), which are the main factors generated by plasma, proved to have a bactericidal effect by inducing lipid peroxidation of bacterial cell membranes. In conclusion, cylinder type DBD plasma with underwater bubbler can be used as an environmentally friendly food disinfection device in cleaning processes of the food industry.

Effects of high voltage nanosecond pulsed plasma and micro DBD plasma on seed germination, growth development and physiological activities in spinach.

In this study, we analyzed seed germination, seedling growth, and physiological aspects after treatment with high voltage nanosecond pulsed plasma and micro DBD plasma in spinach (Spinacia oleracea L.), a green leafy vegetable known to have low germination rate. Both germination and dry weight of seedlings increased after high voltage pulse shots were applied to spinach seeds. However seeds treated with many shots (10 shots) showed a decrease in germination rate and seedling growth. Seeds treated with air DBD plasma exhibited slightly higher germination and subsequent seedling growth than those treated with N2 plasma. Seed surface was degenerated after treated with high voltage pulsed plasma and micro DBD plasma but no significant difference in the degree of degeneration was observed among micro DBD plasma treatment time. Level of GA3 hormone and mRNA expression of an amylolytic enzyme-related gene in seeds were elevated 1 day after treatment with high voltage pulsed plasma. The relative amount of chlorophyll and total polyphenols in spinach seedlings grown from seeds treated with air DBD plasma was increased in 30 s, 1 min, and 3 min treatments. Taken together, our results suggest a possibility that plasma can enhance seed germination by triggering biochemical processes in seeds.

Effect of sequential dry heat and hydrogen peroxide treatment on inactivation of Salmonella Typhimurium on alfalfa seeds and seeds germination.

The purpose of this study was to inactivate Salmonella Typhimurium on alfalfa seeds without having negative effect on seed germination. Inoculated alfalfa seeds were treated with dry heat at 60, 70 or 80 °C for 0, 12, 18 or 24 h followed by 2% hydrogen peroxide solution (10 min). Populations of Salmonella on alfalfa seeds treated with dry heat alone (60, 70 or 80 °C) for up to 24 h were reduced by 0.26-2.76 log CFU/g, and sequential treatment with dry heat and H2O2 reduced populations by 1.66-3.60 log CFU/g. The germination percentage of seeds subjected to sequential treatments was significantly enhanced to up to 97%, whereas that of untreated seeds was only 79.5%. This study suggests that sequential treatment with dry heat and hydrogen peroxide is applicable for reducing levels of Salmonella on seeds while simultaneously enhancing seeds germinability.

Diabetic conditions downregulate the expression of CD2AP in podocytes via PI3-K/Akt signalling.

BACKGROUND: Proteinuria is typically accompanied by structural and compositional changes of the foot processes and of the slit diaphragms between podocytes. CD2-associated protein (CD2AP) in podocytes serves as an adaptor protein binding to nephrin and podocin, anchoring these slit diaphragm proteins to actin filaments of podocyte cytoskeleton and sending signals inward or outward. METHODS: In the present study, we prepared streptozotocin-induced diabetic renal tissues and cultured podocytes in diabetic conditions to investigate podocyte phenotypical changes, including quantitative and distributional changes of CD2AP protein and search for the signalling mechanisms in diabetic conditions. We prepared cultured rat glomerular epithelial cells and mouse podocytes to study how high glucose and advanced glycosylation end products (AGE) induce phenotypical changes of cultured podocyte, under (1) normal glucose (5 mM, = control), (2) high glucose (30 mM), (3) AGE-added or (4) high glucose plus AGE-added conditions. RESULTS: According to diabetic duration, density of CD2AP in renal tissue of experimental diabetic nephropathy became conglomerulated and diminished. In cultured podocytes, CD2AP co-localized with nephrin and zonula occludens-1 by confocal imaging. High glucose and high glucose plus AGE induced the relocalization and concentration of CD2AP at internal cytoplasmic and perinuclear areas of podocytes. High glucose plus AGE-added condition also decreased CD2AP protein amount and its mRNA expression compared with normal glucose or osmotic control conditions. In addition, LY294002, a phosphoinositide 3-kinase inhibitor, prevented the quantitative and distributional changes of CD2AP induced by high glucose and AGE. CONCLUSIONS: These findings suggest that diabetic conditions induce the phenotypical changes of podocyte CD2AP possibly via phosphoinositide 3-kinase/Akt signalling.

Bactericidal Effect of Underwater Plasma Treatment on Waste Brine from Kimchi Production Process and the Evaluation of Reusability of Plasma-Treated Waste Brine in Salting Kimchi Cabbage.

Recycling waste brine from the Kimchi production process is an important environmental and industry issue. We applied an underwater plasma to reduce food-borne pathogens in the waste brine. The capillary electrodes supplied by alternating current (AC) bi-polar pulsed power were applied to treat 100 L of waste brine. The inactivation efficacy was analyzed using four different agars (Tryptic Soy Agar (TSA), Marine agar (MA), de Man Rogosa Sharpe Agar (MRS), and Yeast Extract-Peptone-Dextrose (YPD), respectively. The microbial population was reduced linearly with treatment time, irrespective of culturing medium. The inactivation followed the log-linear model (R2: 0.96-0.99). The reusability of plasma-treated waste brine (PTWB) was determined by five parameters (salinity, pH, acidity, reducing sugar, and the population of microorganisms) of salted Kimchi cabbage, and they were compared with newly made brine (NMB) and waste brine (WB), respectively. The results showed that the quality of salted Kimchi cabbage prepared by PTWB was not significantly different from that of NMB, indicating that the underwater plasma treatment is feasible to reuse waste brine in the salting process of Kimchi production.

Atroposelective desymmetrization of 2-arylresorcinols via Tsuji-Trost allylation.

Palladium-catalyzed asymmetric allylic alkylation has proven to be a powerful method for the preparation of a wide variety of chiral molecules. However, the catalytic and atroposelective allylic alkylation is still rare and challenging, especially for biaryl substrates. Herein, we report the palladium-catalyzed desymmetric and atroposelective allylation, in which the palladium complex with a chiral phosphoramidite ligand enables desymmetrization of nucleophilic 2-arylresorcinols in a highly enantioselective manner. With the aid of the secondary kinetic resolution effect, a wide variety of substrates containing a hydroxymethyl group at the bottom aromatic ring are able to provide O-allylated products up to 98:2 er. Computational studies show an accessible quadrant of the allylpalladium complex and provide three plausible transition states with intra- or intermolecular hydrogen bonding. The energetically favorable transition state is in good agreement with the observed enantioselectivity and suggests that the catalytic reaction would proceed with an intramolecular hydrogen bond.

Regulation of type IV collagen alpha chains of glomerular epithelial cells in diabetic conditions.

An early feature of diabetic nephropathy is the alteration of the glomerular basement membrane (GBM), which may result in microalbuminuria, subsequent macroproteinuria, and eventual chronic renal failure. Although type IV collagen is the main component of thickened GBM in diabetic nephropathy, cellular metabolism of each alpha chains of type IV collagen has not been well studied. To investigate the regulation of alpha(IV) chains in diabetic conditions, we examined whether glucose and advanced glycosylation endproduct (AGE) regulate the metabolism of each alpha(IV) chains in the diabetic tissue and glomerular epithelial cells (GEpC). Glomerular collagen alpha3(IV) and alpha5(IV) chains protein were higher and more intense in immunofluorescence staining according to diabetic durations compared to controls. In vitro, mainly high glucose and partly AGE usually increased total collagen protein of GEpC by [(3)H]-proline incorporation assay and each alpha(IV) chain proteins including alpha1(IV), alpha3(IV), and alpha5(IV) in time-dependent and subchain-specific manners. However, the changes of each alpha(IV) chains mRNA expression was not well correlated to the those of each chain proteins. The present findings suggest that the metabolism of individual alpha(IV) chains of GBM is differentially regulated in diabetic conditions and those changes might be induced not only by transcriptional level but also by post-translational modifications.

Lactobacillus amylovorus KU4 ameliorates diet-induced obesity in mice by promoting adipose browning through PPARγ signaling.

Browning of white adipose tissue (WAT) is currently considered a potential therapeutic strategy to treat diet-induced obesity. While some probiotics have protective effects against diet-induced obesity, the role of probiotics in adipose browning has not been explored. Here, we show that administration of the probiotic bacterium Lactobacillus amylovorus KU4 (LKU4) to mice fed a high-fat diet (HFD) enhanced mitochondrial levels and function, as well as the thermogenic gene program (increased Ucp1, PPARγ, and PGC-1α expression and decreased RIP140 expression), in subcutaneous inguinal WAT and also increased body temperature. Furthermore, LKU4 administration increased the interaction between PPARγ and PGC-1α through release of RIP140 to stimulate Ucp1 expression, thereby promoting browning of white adipocytes. In addition, lactate, the levels of which are elevated in plasma of HFD-fed mice following LKU4 administration, elicited the same effect on the interaction between PPARγ and PGC-1α in 3T3-L1 adipocytes, leading to a brown-like adipocyte phenotype that included enhanced Ucp1 expression, mitochondrial levels and function, and oxygen consumption rate. Together, these data reveal that LKU4 facilitates browning of white adipocytes through the PPARγ-PGC-1α transcriptional complex, at least in part by increasing lactate levels, leading to inhibition of diet-induced obesity.

Delay of renal progression in methylmalonic acidemia using angiotensin II inhibition: a case report.

Methylmalonic acidemia (MMA) is a heterogeneous inborn error of propionate metabolism. Management frequently includes a low-protein diet to minimize precursors of methylmalonic acid and reduce its concentration in body tissues. In the long-term follow-up, renal dysfunction in these patients has been increasingly recognized. Tubulointerstitial nephritis is the most frequent renal complication and has been reported previously by others in the small number of renal biopsy specimens from young children. We report the case of a girl with methylmalonic acidemia and chronic renal insufficiency caused by tubulointerstitial nephritis which showed a considerable delay by angiotensin II inhibition.