Quantifying the energy landscape in weakly and strongly disordered frictional media.

We investigate the "roughness" of the energy landscape of a system that diffuses in a heterogeneous medium with a random position-dependent friction coefficient α(x). This random friction acting on the system stems from spatial inhomogeneity in the surrounding medium and is modeled using the generalized Caldira-Leggett model. For a weakly disordered medium exhibiting a Gaussian random diffusivity D(x) = kBT/α(x) characterized by its average value ⟨D(x)⟩ and a pair-correlation function ⟨D(x1)D(x2)⟩, we find that the renormalized intrinsic diffusion coefficient is lower than the average one due to the fluctuations in diffusivity. The induced weak internal friction leads to increased roughness in the energy landscape. When applying this idea to diffusive motion in liquid water, the dissociation energy for a hydrogen bond gradually approaches experimental findings as fluctuation parameters increase. Conversely, for a strongly disordered medium (i.e., ultrafast-folding proteins), the energy landscape ranges from a few to a few kcal/mol, depending on the strength of the disorder. By fitting protein folding dynamics to the escape process from a metastable potential, the decreased escape rate conceptualizes the role of strong internal friction. Studying the energy landscape in complex systems is helpful because it has implications for the dynamics of biological, soft, and active matter systems.

Polydatin alleviates DSS- and TNBS-induced colitis by suppressing Th17 cell differentiation via directly inhibiting STAT3.

Inflammatory bowel disease (IBD) is a non-specific chronic intestinal inflammatory disease, often presenting with abdominal pain, diarrhea, bloody stool, anorexia, and body loss. It is difficult to cure completely and a promising treatment is urgently needed. Natural compounds can offer promising chemical agents for treatment of diseases. Polydatin is a natural ingredient extracted from the dried rhizome of Polygonum cuspidatum, which has anti-inflammatory, anti-tumor, and dementia protection activities. The purpose of this study was to evaluate the therapeutic effect of polydatin on IBD and explore its possible mechanism. We found that polydatin could effectively suppress the differentiation of Th17 cells in vitro, but had no effect on the differentiation of Treg cells. Polydatin significantly alleviated colitis induced by dextran sulfate sodium (DSS) and 2, 4, 6-trinitrobenzenesulfonic acid (TNBS) in mice, and dramatically decreased the proportion of Th17 cells in spleen and mesenteric lymph nodes. Mechanism investigations revealed that polydatin specifically inhibited signal transducer and activator of transcription 3 (STAT3) phosphorylation by directly binding to STAT3, leading to Th17 cell reduction and thereby alleviating colitis. These findings provide novel insights into the anti-colitis effect of polydatin, which may be a promising drug candidate for the treatment of IBD.

Cryptotanshinone ameliorates dextran sulfate sodium-induced murine acute and chronic ulcerative colitis via suppressing STAT3 activation and Th17 cell differentiation.

Ulcerative colitis (UC) is a chronically relapsing inflammatory disease in the intestinal tract. Current unsatisfactory treatments prompt people to seek for alternative therapies and drug candidates. Cryptotanshinone (CTS), a diterpene quinoneextractedfromthe roots ofSalviamiltiorrhiza, has recently been shown to inhibit acute colitis by reducing pro-inflammatory mediators. However, whether CTS can protect against chronic UC and its effect on T lymphocytes remain unknown. In this study, CTS (20, 60 mg/kg) showed potent inhibitory activity against dextran sulfate sodium (DSS)-induced acute UC, as determined by weight loss, disease activity, colon length and histology. Similarly, in a model of DSS-induced chronic colitis, the administration of CTS prevented the disease progression with longer colon length, lower histological scores, and less expression of fibrosis-related collagen and α-smooth muscle actin in the colon. CTS also reduced the proportion of CD4+IL-17A+ Th17 cells in spleen and mesenteric lymph nodes of mice with acute or chronic colitis. However, CTS at 20 mg/kg had no effect on regulatory T cells (Tregs). In addition, CTS reduced the phosphorylation of signal transduction and transcription activator 3 (STAT3) in DSS-treated colon tissue. Further study showed that CTS concentration-dependently suppressed the differentiation of naïve CD4+ T cells into Th17 cells. CTS could not inhibit the activation and proliferation of T lymphocytes or attenuate the secretion of cytokines including IL-10, IL-2, IL-6 and IFN-γ, but could inhibit the production of IL-17A and TNF-α in Con A-stimulated splenocytes. CTS suppressed IL-6-induced phosphorylation and nuclear translocation of STAT3. In conclusion, our study demonstrated that CTS alleviated acute and chronic UC by suppressing STAT3 activation and Th17 cell differentiation, suggesting that it may be a promising candidate drug for the treatment of UC.

Chemical composition and antifungal activity of essential oil from Origanum vulgare against Botrytis cinerea.

In this study, the chemical composition of the essential oil (EO) of Origanum vulgare was characterized, and the antifungal activity of the EO and some individual components against Botrytis cinerea (Y-BC-1) was determined. Twenty-one components were identified by gas chromatography-mass spectrometry and gas chromatography-flame ionization detection, constituting 95.7% of the EO. The major components were methyleugenol (16.5%), myristicin (15.6%), carvacrol (15.0%), thymol (9.8%), apioline (9.4%), and (Z)-ß-farnesene (8.7%). B. cinerea in vitro mycelial growth and spore germination were strongly inhibited by the EO and two of its main components, thymol and carvacrol. In vivo vapor contact assays, the antifungal activity of the EO at 250 mg/L suppressed the decay of cherry tomatoes 96.39%. Moreover, thymol and carvacrol at 125 mg/L completely suppressed the gray mold. Thus, the EO of O. vulgare is a potentially nontoxic and ecofriendly botanical fungicide for postharvest control of gray mold.

[Chemical composition and allelopathic potential of essential oil isolated from Origanum vulgare]. / ç‰›è‡³æŒ¥å‘æ²¹çš„åŒ–å­¦æˆåˆ†åŠå ¶åŒ–æ„Ÿä½œç”¨.

This study aimed to explore the chemical composition of essential oil isolated from Origanum vulgare and investigated its allelopathic potential. The essential oil isolated by hydro-distillation from the whole plant of O. vulgare was analyzed by GC and GC-MS. Fourteen different components were identified, constituting 93.56% of the total area of peaks. The major components were methyleugenol (16.5%), myristicin (15.6%), carvacrol (15.0%), thymol (9.8%), and apioline (9.4%). We examined the inhibitory effects of essential oil on seed germination and seedling growth of wheat (Triticum aestivum), mung bean (Vigna radiata), and radish (Raphanus sativus). The results showed that essential oil of O. vulgare inhibited seed germination of all tested crops, with wheat being the most susceptible, followed by radish and mung bean. The inhibitory effects of essential oil on growth of the aboveground part of tested crops were greater than that of underground part. The inhibitory effects of essential oil on the seedling length of all tested crops increased in a dose-dependent manner, with the same pattern for radicle length of wheat and radish as well. Meanwhile, essential oil could stimulate radicle growth of V. radiata at low concentration, but inhibit the growth at high concentration. Our results confirmed the existence of allelochemicals in the essential oil of O. vulgare. However, what the compounds will be and how about their allelopathic mechanism needs further investigation.

Two novel metal-organic frameworks based on pyridyl-imidazole-carboxyl multifunctional ligand: selective CO2 capture and multiresponsive luminescence sensor.

Two novel metal-organic frameworks, formulated as [Mn(CIP-)2] (1) and [Ag(CIP-)] (2) (HCIP = 4-(4-carboxylphenyl)-2,6-di(4-imidazol-1-yl)phenyl)pyridine), were solvothermally synthesized based on a pyridyl-imidazole-carboxyl multifunctional ligand. The single-crystal X-ray diffraction analysis shows that complex 1 is a 3D microporous framework with uncoordinated imidazole groups, and complex 2 is a 2D + 2D → 2D 3-fold parallel interpenetrated network. Complex 1 exhibited excellent CO2 selective absorption over N2 and CH4. IAST calculations revealed that the selectivities of 1 for the CO2/CH4 (50 : 50) and CO2/N2 (15 : 85) mixtures were 8.0 and 117 at 273 K under 1 bar, respectively. Moreover, the luminescence investigations displayed that complex 2 is an excellent MOF-based multiresponsive fluorescent probe for Fe3+, CrO42-/Cr2O72- and the pesticide 2,6-Dich-4-nitroaniline, with high selectivity and sensitivity. Notably, complex 2 exhibited a highly sensitive sensing ability (5.2 × 104 M-1) and a low detection limit (1.7 × 10-7 M) for 2,6-Dich-4-nitroaniline. To the best of our knowledge, this is the first Ag-MOF-based fluorescent sensor that can simultaneously detect metal ions, inorganic anions and pesticides.

Long-term outcomes of surgical treatment for pulmonary carcinoid tumors: 20 years' experience with 131 patients.

BACKGROUND: Bronchial carcinoids are rare malignant neuroendocrine neoplasms. Some issues regarding surgical treatment of bronchial carcinoids remain controversial, including the role of bronchoplastic surgery and necessity of systematic lymphadenectomy. METHODS: This retrospective study involved 131 consecutive patients surgically treated for carcinoid tumors at Shanghai Chest Hospital between March 1990 and August 2010. RESULTS: Eighty-nine (67.9%) of the patients were male, and the mean age was 46 years, ranging from 17 to 81 years. Preoperative fiberoptic bronchoscopy was performed in all patients. Endoscopic biopsy was performed in 100 patients with central tumors, and 70 (70%) patients were diagnosed as bronchial carcinoid. The resections performed consisted of 31 pneumonectomie, 32 lobectomies, 26 bilobectomies, 34 sleeve lobectomies, six bronchoplastic procedures without lung resection, and two segmentectomies. During a median of 87 months follow-up, there were nine recurrences including three local recurrences and 6 distant recurrences. No bronchial recurrences were observed. The 3-, 5- and 10-year overall survival rates of pneumonectom and bronchoplastic surgery (including sleeve lobectomy and bronchoplastic procedure without lung resection) were 93.2%, 81.0% and 69.4%, 97.5%, 91.9% and 70.0%, respectively. Multivariate Cox regression indicated that histology and nodal status were significant independent prognostic factors. CONCLUSIONS: Bronchoplastic surgery should be considered whenever possible for central carcinoids. Systematic lymphadenectomy is recommended for bronchial carcinoid patients. Histology and nodal status were significant independent prognostic factors of overall survival of patients with bronchial carcinoid.

Approach to the biosynthesis of atisine-type diterpenoid alkaloids.

To determine the biosynthesis pathway of the atisine-type diterpenoid alkaloids spiramines A/B and C/D, feeding experiments in in vitro cultured plantlets and enzymatic transformations in cell-free extracts were performed in combination with LCMS and tandem MS analyses. L-[2-(13)C,(15)N]Serine was used in the feeding experiments and enzymatic transformations, and the diterpene spiraminol was identified as a biosynthetic precursor of spiramine alkaloids. The LCMS and tandem MS spectra of the extracts from these experiments indicated that L-[2-(13)C,(15)N]serine was incorporated into spiramines A/B and C/D. The labeled reaction products show that l-serine is the one possible nitrogen source involved in the biosynthesis of atisine-type DAs.

MFTZ-1, an actinomycetes subspecies derived antitumor macrolide, functions as a novel topoisomerase II poison.

14-Ethyl-2,5,11-trimethyl-4,13,19,20-tetraoxa-tricyclo[14.2.1.1(7,10)]eicosane-3,12-dione (MFTZ-1), a new macrolide compound isolated from Streptomyces sp. Is9131, displayed wide cytotoxicity in human tumor cell lines with an average IC(50) of 0.905 micromol/L. Notably, MFTZ-1 showed significant cytotoxicity in the three multidrug resistance cell lines with an average resistance factor of 2.08. The in vivo experiments showed that MFTZ-1 had inhibitory effects on the human ovarian carcinoma HO-8910 cell line xenotransplanted in nude mice. Further studies showed that MFTZ-1 induced DNA double-strand breaks and triggered mitochondria-dependent apoptosis in human leukemia HL-60 cells. Using a yeast genetic system, we found that topoisomerase (Topo) II rather than Topo I was the primary cellular target of MFTZ-1. Most importantly, MFTZ-1 functions as a novel nonintercalative Topo II poison via binding to ATPase of Topo II, characterized by its strong inhibition on the decatenation and relaxation of Topo II. The capacity of MFTZ-1 to stabilize Topo II-DNA covalent complexes was comparable with that of the classic Topo II poison, etoposide. Moreover, using a Topo II catalytic inhibitor aclarubicin and Topo II-deficient HL-60/MX2 cells, we further showed that MFTZ-1-triggered DNA double-strand breaks and apoptosis occurred in a Topo II-dependent manner. Together, the well-defined Topo II-poisoning function and the potent antitumor activity, with the appreciable anti-multidrug resistance action in particular, promises MFTZ-1 as a novel potential Topo II-targeted agent, which merits further research and development.

Antibacterial and antitumor macrolides from Streptomyces sp. Is9131.

Four compounds, including two novel macrolides, were isolated from an endophyte Streptomyces sp. Is9131 of Maytenus hookeri. Spectral data indicated that these compounds were dimeric dinactin (1), dimeric nonactin (2), cyclo-homononactic acid (3), and cyclo-nonactic acid (4). Bioassay results showed that dimeric dinactin had strong antineoplastic activity and antibacterial activity.

[Causes and prevention of anastomotic leakage after esophagectomy and reconstruction through different routes for esophageal cancer].

OBJECTIVE: To compare the anastomotic leakage rates after esophagectomy and reconstruction through different routes for esophageal cancer and analyze the causes for higher anastomotic leakage rate after esophagectomy, systemic lymph node dissection and reconstruction through retrosternal route and its prevention. METHODS: Data of 1105 cases of esophagectomy were reviewed retrospectively. Patients in group A (n=229) underwent esophagectomy through left thoracotomy and intrathoracic anastomosis, patients in group B (n=716), esophagectomy through right anterio-lateral thoracotomy and cervical reconstruction through posterior mediastinal route, patients in group C (n=160) esophagectomy, systemic lymph node dissection and cervical anastomosis through the retrosternal route. RESULTS: The leakage rate was significantly higher (19.4%) in group C than that in group B (11.9%, P< 0.05) and much significantly higher than that in group A (2.2%, P< 0.01). In group C, there was no significant difference in leakage rate between the patients with hand-sewn or mechanical anastomosis (22.2% vs.11.6%, P=0.133), between the patients who had whole stomach or tube-typed gastric reconstruction (25% vs.15.6%, P=0.146). The leakage rate was significantly decreased from 23.3% to 9.1% after prolonged nasal-gastric drainage for seven days (P< 0.05). CONCLUSION: The high anastomotic leakage rate after retrosternal reconstruction is mainly due to compression of the stomach in the anterior mediastinum. Prolonged nasogastric drainage is an effective way to decrease the leakage rate after systemic lymphadenectomy.

The efficiency of humoral immune transfer depends on both the graft and the immunosuppressive treatment.

The present study was designed to compare the efficiency of adoptive transfer of humoral immunity after liver, kidney, and heart transplantation in relation to the number of passenger lymphocytes, and to estimate the risk of a detrimental effect and the chance of a beneficial effect. Hepatitis B virus surface-antigen-vaccinated brown Norway rats (BNs) and AxC 9935 Irish (ACI rats) served as donors, and naïve Lewis (LEW) rats as recipients. The liver grafts contained 100 times more passenger lymphocytes than heart grafts, and the kidney grafts approximately ten times more, indicated by monoclonal CD45 antibody staining. Transient anti-HBs immunity did occur after transplantation of all three organ grafts. In all rejecting groups, the serum recipient-to-donor anti-HBs titer ratio (R/D ratio) was below 0.10%, with heart recipients showing half the level (0.05%) of liver recipients (0.09%). Under immunosuppression, R/D ratio doubled in liver or kidney recipients, but remained unaffected in heart recipients. Immune transfer was most efficient in immune-suppressed liver recipients in the spontaneously tolerant strain combination as indicated by a significantly higher R/D ratio (0.32%) and a longer titer persistence (up to 9 weeks) than in all other groups. Therefore, mainly liver and kidney graft recipients carry a risk, but also a chance of benefiting from the transfer of donor-derived immunity.