Dental caries is a biofilm-dependent oral disease and Streptococcus mutans is the known primary etiologic agent of dental caries that initiates biofilm formation on tooth surfaces. Although some ...Lactobacillus strains inhibit biofilm formation of oral pathogenic bacteria, the molecular mechanisms by which lactobacilli inhibit bacterial biofilm formation are not clearly understood. In this study, we demonstrated that Lactobacillus plantarum lipoteichoic acid (Lp.LTA) inhibited the biofilm formation of S. mutans on polystyrene plates, hydroxyapatite discs, and dentin slices without affecting the bacterial growth. Lp.LTA interferes with sucrose decomposition of S. mutans required for the production of exopolysaccharide, which is a main component of biofilm. Lp.LTA also attenuated the biding of fluorescein isothiocyanate-conjugated dextran to S. mutans, which is known to have a high affinity to exopolysaccharide on S. mutans. Dealanylated Lp.LTA did not inhibit biofilm formation of S. mutans implying that D-alanine moieties in the Lp.LTA structure were crucial for inhibition. Collectively, these results suggest that Lp.LTA attenuates S. mutans biofilm formation and could be used to develop effective anticaries agents.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Rapid and efficient nucleic acid (NA) extraction and concentration are required for point-of-care analysis in order to prevent an epidemic/pandemic disease outbreak. Typical silica-based NA ...extraction methods have limitations such as being time-consuming, requiring human intervention, and resulting in a low recovery yield. In this study, we have developed a pathogenic DNA extraction device based on electrokinetic separation incorporated with a silicon nitride (SiN
x
) nanofilter, which expedites the DNA extraction procedure with advantages of being convenient, efficient, and inexpensive. This DNA extraction device consists of a computer numerical control (CNC) milled-Teflon gadget with a
cis
-chamber as a cell lysate reservoir and a
trans
-chamber as a elution solution reservoir, with the SiN
x
nanofilter being inserted between the two chambers. The SiN
x
nanofilter was fabricated using a photolithographic method in conjunction with nanoimprinting. Approximately 7.2 million nanopores of 220 nm diameter were located at the center of the nanofilter. When a DC electric field is applied through the nanopores, DNA is transferred from the
cis
-chamber to the
trans
-chamber to isolate the DNA from the cell debris. To demonstrate the DNA extraction performance, we measured the absorbances at 260 and 280 nm and performed a real-time polymerase chain reaction (real-time PCR) using the recovered DNA to verify its feasibility for downstream genetic analysis. Moreover, the DNA extraction device was successfully operated using a 1.5 V alkaline battery, which verifies the portability of the device for point-of-care testing. Such an advanced DNA extraction system can be utilized in various fields including clinical analysis, pathogen detection, forensic analysis, and on-site detection.
A simple electrophoretic DNA extraction device has developed using a nanofilter for rapid and efficient DNA aquisition required for point-of-care analysis in order to prevent an epidemic/pandemic disease outbreak.
Solid-state nanopores have been widely used in the past for single-particle analysis of nanoparticles, liposomes, exosomes and viruses. The shape of soft particles, particularly liposomes with a ...bilayer membrane, can greatly differ inside the nanopore compared to bulk solution as the electric field inside the nanopores can cause liposome electrodeformation. Such deformations can compromise size measurement and characterization of particles, but are often neglected in nanopore resistive pulse sensing. In this paper, we investigated the deformation of various liposomes inside nanopores. We observed a significant difference in resistive pulse characteristics between soft liposomes and rigid polystyrene nanoparticles especially at higher applied voltages. We used theoretical simulations to demonstrate that the difference can be explained by shape deformation of liposomes as they translocate through the nanopores. Comparing our results with the findings from electrodeformation experiments, we demonstrated that the rigidity of liposomes can be qualitatively compared using resistive pulse characteristics. This application of nanopores can provide new opportunities to study the mechanics at the nanoscale, to investigate properties of great value in fundamental biophysics and cellular mechanobiology, such as virus deformability and fusogenicity, and in applied sciences for designing novel drug/gene delivery systems.
Background
The incidence and clinical presentation of internal hernia after gastrectomy have been changing in the minimally invasive surgery era. This study aimed to analyze the clinical features and ...risk factors for internal hernia after gastrectomy for gastric cancer.
Methods
We retrospectively analyzed internal hernia after gastrectomy for gastric cancer in 6474 patients between January 2003 and December 2016 at Seoul National University Bundang Hospital. Multivariable logistic regression was performed to evaluate risk factors.
Results
Internal hernias identified by computed tomography or surgical exploration were 111/6474 (1.7%) and the median interval time was 450 days after gastrectomy. Fourteen (0.9%) of the 1510 patients who underwent open gastrectomy and 97 (2.0%) of the 4964 patients who underwent laparoscopic gastrectomy developed internal hernia. Of the 6474 patients, internal hernia developed in 0 (0%), 9 (1.1%), 40 (3.1%), 56 (3.3%), 6 (2.3%), and 0 (0%) patients who underwent Billroth I, Billroth II, Roux-en-Y, uncut Roux-en-Y, double tract, and esophagogastrostomy reconstructions, respectively. Fifty-nine (53.2%) of 111 patients with symptomatic hernia underwent surgery. Of the 59 internal hernias, treated surgically, 32 (53.2%), 27 (45.8%), and 0 (0%) were identified in jejunojejunostomy mesenteric, Petersen’s, and transverse colon mesenteric defects, respectively. In multivariate analysis, non-closure of mesenteric defects (
P
< 0.01), laparoscopic approach (
P
< 0.01), and totally laparoscopic approach (
P
= 0.03) were independent risk factors for internal hernia.
Conclusions
The potential spaces such as Petersen’s, jejunojejunostomy mesenteric, and transverse colon mesenteric defects should be closed to prevent internal hernia after gastrectomy for gastric cancer.
A biofilm is an aggregate of microorganisms in which cells adhere to biological or non-biological surfaces and is responsible for various infectious diseases. Infections caused by
, including ...pneumonia, endocarditis, and osteomyelitis, are often associated with colonization and biofilm formation. Although lipoteichoic acid (LTA) is involved in biofilm formation, the specific role of LTA is not clearly understood. In this study, we demonstrated that LTA released from
could inhibit
biofilm formation and aggregation without affecting the growth of
in various
and
models.
LTA (Lp.LTA) also inhibited biofilm formation of
clinical isolates, including a methicillin-resistant strain. Remarkably, Lp.LTA not only interfered with
biofilm formation, but it also disrupted a pre-formed biofilm. Mechanism studies demonstrated that Lp.LTA inhibited expression of the
-operon, which is responsible for the production of poly-
-acetylglucosamine, a key molecule required for
biofilm development. Lp.LTA increased the release of autoinducer-2 from
, which contributed to the inhibition of
biofilm formation. Moreover, Lp.LTA treatment enhanced susceptibility of the biofilm to various antibiotics and to macrophages. Interestingly, Lp.LTA without D-alanine moieties was not able to inhibit biofilm formation by
. In conclusion, the present study suggests that LTA can inhibit
biofilm formation, and therefore could be applied for preventing and/or treating infectious diseases caused by
biofilms.
Probiotics in livestock feed supplements are considered a replacement for antibiotics that enhance gastrointestinal immunity. Although bacterial cell wall components have been proposed to be ...associated with probiotic function, little evidence demonstrates that they are responsible for probiotic functions in livestock. The present study demonstrated that lipoteichoic acid (LTA) of
(Lp.LTA) confers anti-inflammatory responses in porcine intestinal epithelial cell line, IPEC-J2. A synthetic analog of viral double-stranded RNA, poly I:C, dose-dependently induced IL-8 production at the mRNA and protein levels in IPEC-J2 cells. Lp.LTA, but not lipoprotein or peptidoglycan from
, exclusively suppressed poly I:C-induced IL-8 production. Compared with LTAs from other probiotic
strains including
,
, and
GG, Lp.LTA had higher potential to suppress poly I:C-induced IL-8 production. Dealanylated or deacylated Lp.LTA did not suppress poly I:C-induced IL-8 production, suggesting that D-alanine and lipid moieties in the Lp.LTA structure were responsible for the inhibition. Furthermore, Lp.LTA attenuated the phosphorylation of ERK and p38 kinase as well as the activation of NF-κB, resulting in decreased IL-8 production. Taken together, these results suggest that Lp.LTA acts as an effector molecule to inhibit viral pathogen-induced inflammatory responses in porcine intestinal epithelial cells.
Most patients with gastric cancer rapidly lose weight after gastrectomy. Therefore, analysis of the effect of body mass index (BMI) on patients with gastric cancer survival should include ...postoperative BMI and BMI loss and preoperative BMI. This retrospective cohort study analyzed the effect of three BMI variables and their interaction on long-term outcomes.
Preoperative BMI analysis included 2,063 patients with gastric cancer who underwent curative gastrectomy between January 2009 and December 2013 at Seoul National University Bundang Hospital. BMI at postoperative 6 to 12 months was available in 1,845 of these cases.
Patients with preoperative BMI 23.0 to <27.5 HR, 0.63; 95% confidence interval (CI), 0.48-0.82 for BMI 23.0 to <25.0 and HR, 0.57; 95% CI, 0.42-0.78 for BMI 25.0 to <27.5 and postoperative BMI 23.0 to <25.0 (HR, 0.67; 95% CI, 0.46-0.98) showed significantly better overall survival (OS) than pre- and postoperative patients with BMI 18.5 to <23.0, respectively. Postoperative underweight (BMI <18.5; HR, 1.74; 95% CI, 1.27-2.37) and postoperative severe BMI loss (>4.5; HR, 1.79; 95% CI, 1.29-2.50) were associated with higher mortality. Severe BMI loss and preoperative BMI <23.0 had an adverse synergistic effect; patients with BMI <23.0 were more vulnerable to severe BMI loss than those with BMI ≥23.0. Associations with cancer-specific survival were similar.
All three BMI variables were prognostic factors for survival of patients with gastric cancer. Preoperative BMI and severe BMI loss had an interaction.
Perioperative BMI and weight loss should be analyzed collectively in patients with gastric cancer undergoing gastrectomy.
.
This study evaluated the association of atherogenic index of plasma (AIP) with platelet reactivity and clinical outcomes according to acute myocardial infarction (AMI). The composite of 3-year ...adverse outcomes of all-cause death, myocardial infarction, and cerebrovascular accident was evaluated in 10,735 patients after successful percutaneous coronary intervention with drug-eluting stents. AIP was defined as the base 10 logarithm of the ratio of triglyceride to high-density lipoprotein cholesterol concentration. High platelet reactivity (HPR) was defined as ≥ 252 P2Y12 reactivity unit. An increase of AIP (per-0.1 unit) was related to the decreased risk of HPR odds ratio (OR) 0.97, 95% confidence interval (CI) 0.96-0.99; P = 0.001 in non-AMI patients, not in AMI patients (OR 0.98, 95% CI 0.96-1.01; P = 0.138). The HPR was associated with the increased risk of composite outcomes in both non-AMI and AMI patients (all-P < 0.05). AIP levels were not independently associated with the risk of composite outcomes in both patients with non-AMI and AMI. In conclusion, an inverse association between AIP and the risk of HPR was observed in patients with non-AMI. This suggests that the association between plasma atherogenicity and platelet reactivity may play a substantial role in the development of AMI.Trial registration: NCT04734028.
A critical limitation of Salmonella typhimurium (S. typhimurium) as an anti-cancer agent is the loss of their invasive or replicative activities, which results in no or less delivery of anti-cancer ...agents inside cancer cells in cancer therapy. Here we developed an oxytolerant attenuated Salmonella strain (KST0650) from the parental KST0649 (ΔptsIΔcrr) strain using radiation mutation technology (RMT). The oxytolerant KST0650 strain possessed 20-times higher replication activity in CT26 cancer cells and was less virulent than KST0649. Furthermore, KST0650 migrated effectively into tumor tissues in mice. KST0650 was further equipped with a plasmid harboring a spliced form of the intracellular pro-apoptotic protein sATF6, and the expression of sATF6 was controlled by the radiation-inducible recN promoter. The new strain was named as KST0652, in which sATF6 protein expression was induced in response to radiation in a dose-dependent manner. This strain was effectively delivered inside cancer cells and tumor tissues via the Salmonella type III secretion system (T3SS). In addition, combination treatment with KST0652 and radiation showed a synergistic anti-tumor effect in murine tumor model with complete inhibition of tumor growth and protection against death. In conclusion, we showed that RMT can be used to effectively develop an anti-tumor Salmonella strain for delivering anti-cancer agents inside tumors.
Tissues within the central nervous system (CNS) have generally been regarded as immunologically privileged. However, in recent decades, it has been shown that immune reactions in the CNS continuously ...occur via various types of inflammation following autoimmune diseases and mechanical insults such as spinal cord injury (SCI). Among the various inflammatory cells associated with CNS disease, activated macrophages are classically known to induce detrimental consequences that are mediated by the secretion of pro-inflammatory molecules. Alternatively activated macrophages have recently been shown to modulate various types of CNS inflammation, including SCI. This review summarizes the potential roles of alternatively activated macrophages in the course of CNS inflammation in rodent SCI models.
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