A Method for the Enhancement of Environmental Stress Resistance of Endoparasitic Fungus Esteya vermicola

Esteya vermicola is the first recorded endoparasitic fungus of the pinewood nematode, Bursaphelenchus xylophilus, which is the causal agent for the pine wilt disease. Culture on modified agar media with herbal extraction (0.5%) was found to be able to induce resistance to UV radiation, heat and drought conditions in Esteya vermicola. Herba Houttuyniae, Tatraxacum officinale and Scutellaria baicalensis Georgi exhibited the highest improvement on environmental competence of Esteya vermicola at all the tested time points under the stress conditions. In addition, improved quality and effective viability of Esteya vermicola were observed amended with the three herbal extractions in culture media. Enhanced stress resistance was associated with herbal metabolites. These findings provided a green, feasible, economical method for developing an open‐field spay application of fungal biocontrol agents against pine wilt disease.     

Intestinal Methanobrevibacter smithii but not total bacteria is related to diet‐induced weight gain in rats

It is increasingly understood that gastrointestinal (GI) methanogens, including Methanobrevibacter smithii, influence host metabolism.

Objective:

Therefore, we compared M. smithii colonization and weight gain in a rat model under different dietary conditions.

Design and Methods:

Sprague‐Dawley rats were inoculated with M. smithii or vehicle (N = 10/group), fed normal chow until day 112 postinoculation, high‐fat chow until day 182, then normal chow until day 253. Thereafter, five rats from each group were fed high‐fat and normal chow until euthanasia.

Results:

Both groups exhibited M. smithii colonization, which increased following inoculation only for the first 9 days. Change to high‐fat chow correlated with significant increases in weight (P < 0.00001) and stool M. smithii (P < 0.01) in all rats, with stool M. smithi decreasing on return to normal chow. Rats switched back to high‐fat on day 253 further increased weight (P < 0.001) and stool M. smithii (P = 0.039). Euthanasia revealed all animals had higher M. smithii, but not total bacteria, in the small intestine than in the colon. Rats switched back to high‐fat chow had higher M. smithii levels in the duodenum, ileum, and cecum than those fed normal chow; total bacteria did not differ in any bowel segment. Rats which gained more weight had more bowel segments colonized, and the lowest weight recorded was in a rat on high‐fat chow which had minimal M. smithii colonization.

Conclusions:

We conclude that M. smithii colonization occurs in the small bowel as well as in the colon, and that the level and extent of M. smithii colonization is predictive of degree of weight gain in this animal model.     

DNA data and morphology reveal the existence of Kentrochrysalis streckeri Staudinger, 1880 (Lepidoptera: Sphingidae) instead of K. consimilis in South Korea

In the present study, we determined that specimens of Kentrochrysalis consimilis collected from South Korea were K. streckeri, rather than K. consimilis, based on morphology, DNA barcodes and nuclear elongation factor 1 alpha (EF‐1α) sequences. The major morphological differences between K. streckeri and K. consimilis include the shape of forewing and hind‐wing pattern elements and male and female genitalia. The DNA barcode analysis of the South Korean specimens and the Russia‐originated K. streckeri showed a maximum sequence divergence of only 0.659% (4 bp), whereas that of the South Korean specimens and Japan‐originated K. consimilis showed a minimum sequence divergence of 2.965% (18 bp), indicating that the Korean specimens are, in fact, K. streckeri and not K. consimilis. Phylogenetic analyses both by Bayesian inference and maximum likelihood methods strongly clustered the South Korean specimens and Russian K. streckeri into one group, excluding K. consimilis. The EF‐1α‐based sequence and phylogenetic analyses of the two species also supported data from the DNA barcode, indicating the distribution of K. streckeri in South Korea, instead of K. consimilis.     

Prognostic Value of Lactate and Central Venous Oxygen Saturation after Early Resuscitation in Sepsis Patients

The objective of this study was to evaluate the prognostic value of static and dynamic variables of central venous oxygen saturation (ScvO₂) and lactate in patients with severe sepsis or septic shock who underwent early quantitative resuscitation. We also investigated whether ScvO₂ measured after initial resuscitation could provide additive prognostic value to that of lactate. We analyzed the sepsis registry for patients presenting to the emergency department and included patients with simultaneous measurements of lactate and ScvO₂ at the time of presentation (H0) and 6 hours (H6) after resuscitation. The primary outcome was 28-day mortality and multivariable logistic analysis was used to adjust for confounders. A total of 363 patients were included, and the overall 28-day mortality was 18%. The area under the receiver operator characteristic curve for predicting 28-day mortality was as follows: lactate (H6), 0.81; lactate (H0), 0.73; relative lactate change, 0.67; ScvO₂ (H6), 0.65; relative ScvO₂ change 0.59; ScvO₂ (H0), 0.58. Patients with lactate normalization showed significantly lower 28-day mortality compared to patients without lactate normalization (3% vs. 28%, P<0.01). However, in those who achieved ScvO₂ (H6) ≥70%, there was a significant difference in 28-mortality only in patients without lactate normalization (21% vs. 39%, P<0.01) but no difference in those with lactate normalization (4% vs. 3%, P = 0.71). In multivariable analysis, lactate normalization was significantly associated with 28-day mortality (adjusted odds ratio [OR] for 28-day mortality, 0.20; 95% confidence interval [CI], 0.07–0.54; P <0.01), but ScvO₂ (H6) ≥70% showed only a marginal association (the adjusted OR for 28-day mortality, 0.51; 95% CI, 0.26–1.01; P = 0.05). ScvO₂ (H6) ≥70% was associated with 28-day mortality only in cases without lactate normalization in subgroup analysis (adjusted OR 0.37, 95% CI, 0.18–0.79; P = 0.01). Six-hour lactate was the strongest predictor of 28-day mortality in patients with severe sepsis or septic shock. Six-hour ScvO₂ provided additional prognostic value only in cases where lactate values were not normalized after resuscitation.     

Medium composition for effective slow freezing of embryonic cell lines derived from marine medaka (Oryzias dancena)

This study was conducted to identify optimal medium composition for freezing Oryzias dancena embryonic cell lines. Different freezing media consisting of various concentration of dimethyl sulfoxide (DMSO), fetal bovine serum (FBS), and trehalose were prepared and long-term cultured embryonic cell line was frozen in each freezing medium by conventional slow freezing program for 7 days. Through measurement of viability and growth of post-thaw cells frozen in each freezing medium, it was determined that optimal composition of three components was 10 % DMSO, 20 % FBS, and 0.1 M trehalose. The post-thaw cells frozen in optimal freezing medium showed similar morphology and growth rate with non-frozen cells. Next, this condition was applied to two different sets of experiment; (1) freezing of the same cells during expanded period (57 days) and (2) freezing of short-term cultured cells from other batches for 7 days. The viability of post-thaw cells was significantly low and comparable in set 1 and 2, respectively, when compared with the result of long term-cultured cells frozen in optimal freezing medium for 7 days and similar morphology and growth rate with non-frozen counterparts were detected in the post-thaw cells from both sets. In conclusion, this study first reports the optimal medium composition for freezing O. dancena embryonic cells, which can contribute to fish species preservation as well as improvement of cell-based biotechnology by providing stable cell storage.     

TrkB Promotes Breast Cancer Metastasis via Suppression of Runx3 and Keap1 Expression

In metastatic breast cancer, the acquisition of malignant traits has been associated with the increased rate of cell growth and division, mobility, resistance to chemotherapy, and invasiveness. While screening for the key regulators of cancer metastasis, we observed that neurotrophin receptor TrkB is frequently overexpressed in breast cancer patients and breast cancer cell lines. Additionally, we demonstrate that TrkB expression and clinical breast tumor pathological phenotypes show significant correlation. Moreover, TrkB expression was significantly upregulated in basal-like, claudin-low, and metaplastic breast cancers from a published microarray database and in patients with triple-negative breast cancer, which is associated with a higher risk of invasive recurrence. Interestingly, we identified a new TrkB-regulated functional network that is important for the tumorigenicity and metastasis of breast cancer. We demonstrated that TrkB plays a key role in regulation of the tumor suppressors Runx3 and Keap1. A markedly increased expression of Runx3 and Keap1 was observed upon knockdown of TrkB, treatment with a TrkB inhibitor, and in TrkB kinase dead mutants. Additionally, the inhibition of PI3K/AKT activation significantly induced Runx3 and Keap1 expression. Furthermore, we showed that TrkB enhances metastatic potential and induces proliferation. These observations suggest that TrkB plays a key role in tumorigenicity and metastasis of breast cancer cells through suppression of Runx3 or Keap1 and that it is a promising target for future intervention strategies for preventing tumor metastasis and cancer chemoprevention.