The roles of branched-chain amino acids metabolism in tumorigenesis and progression.

Branched-chain amino acids (BCAAs), including leucine, valine, and isoleucine, play crucial roles in regulating metabolic balance and maintaining physiological functions in the body. Extensive studies have been focused on their implications in obesity, diabetes, and cardiovascular diseases. Nevertheless, accumulating evidence suggests that BCAAs metabolism also plays significant roles in tumorigenesis and progression. In this review, we overview recent progress of the study on BCAAs metabolism including its relationship with epigenetic regulation. Particularly, we discuss the metabolic reprogramming and metabolic sensing of BCAAs and its intermediate metabolites in tumor cells and microenvironment to decipher their functions. An enhanced understanding of the roles and mechanism of BCAAs metabolism in tumorigenesis and progression will contribute to development of novel therapeutic strategies against tumor.

Three new cassane-type diterpenoids from Caesalpinia sinensis.

Three new cassane-type diterpenoids, namely, (4S)-6ß,12α,19-trihydroxy-cass-13(15)-en-16,12-olide (1), cass-13(15)-en-​16,12-olide (2), and 12α-hydroxy-cass-13(15)-en-16,12-olide (3), were isolated from the seeds of Caesalpinia sinensis. The structures of 1-3 were established by extensive spectroscopic analysis, and their absolute configurations were assigned by electronic circular dichroism (ECD) calculations. The inhibitory activities against PTP1B of the isolated compounds were evaluated. The results showed that compound 2 possessed PTP1B inhibitory activity with an IC50 value of 217.45 ± 36.4 µM.

Overexpression of miR-18a negatively regulates myocyte enhancer factor 2D to increase the permeability of the blood-tumor barrier via Krüppel-like factor 4-mediated downregulation of zonula occluden-1, claudin-5, and occludin.

miR-18a represses angiogenesis and tumor evasion by weakening vascular endothelial growth factor and transforming growth factor-ß signaling to prolong the survival of glioma patients, although it is thought to be an oncogene. This study investigates the potential effects of miR-18a on the permeability of the blood-tumor barrier (BTB) and its possible molecular mechanisms. An in vitro BTB model was successfully established. The endogenous expression of miR-18a in glioma vascular endothelial cells (GECs) was significantly lower than that in normal vascular ECs, and the overexpression of miR-18a significantly increased the permeability of the BTB as well as downregulating the mRNA and protein expressions of tight junction-related proteins zonula occluden-1 (ZO-1), claudin-5, and occludin in GECs. Dual luciferase reporter assays revealed that miR-18a bound to the 3'-untranslated region (3'UTR) of myocyte enhancer factor 2D (MEF2D). The overexpression of both miR-18a and MEF2D with the 3'UTR significantly weakened the effect caused by miR-18a of decreasing the mRNA and protein expressions of ZO-1, claudin-5 and occludin and of increasing the permeability of the BTB. Chromatin immunoprecipitation showed that MEF2D could directly bind to KLF4 promoter. This study shows that miR-18a targets and negatively regulates MEF2D, which further regulates tight junction-related proteins ZO-1, claudin-5, and occludin through transactivation of KLF4 and, finally, changes the permeability of the BTB. MiR-18a should garner growing attention because it might serve as a potential target in opening the BTB and providing a new strategy for the treatment of gliomas.

Optimal dilation duration of 10 mm diameter balloons after limited endoscopic sphincterotomy for common bile duct stones: a randomized controlled trial.

Limited endoscopic sphincterotomy (EST) combined with endoscopic papillary balloon dilation (EPBD) is widely used. However, the optimal duration of small balloon dilation in choledocholithiasis remains controversial. We aimed to determine the optimal duration for 10 mm diameter balloon dilation after limited EST in choledocholithiasis. In this randomized controlled clinical trial, 320 patients were randomly assigned to receive small balloon dilation (10 mm in diameter) for 1 min (n = 160) or 3 min (n = 160) after deep bile duct cannulation. No significant difference in success rate of stone extraction between the two groups was observed. The incidence of post-ERCP pancreatitis (PEP) was higher in the 1 min group (10.6%) than in the 3 min group (4.4%) (P = 0.034). The logistic regression analysis showed that guidewire into the pancreatic duct, cannulation time > 5 min and 1 min balloon dilation were independent risk factors for PEP. There were no significant differences in other post-ERCP adverse events such as acute cholangitis, bleeding, perforation, etc. between the two groups. In conclusion, 3 min in duration was determined to be the optimal dilation condition for the removal of common bile duct stones.

Feasibility and Safety of Transgastric Natural Orifice Transluminal Endoscopic Surgery in the Diagnosis of Ascites of Unknown Origin.

Objective: The purpose of this study was to evaluate the feasibility and safety of transgastric natural orifice transluminal endoscopic surgery (TG-NOTES) combined with biopsy in the diagnosis of unknown ascites. Method: This retrospective study used data from the first affiliated hospital of Nanchang university on 51 patients who were diagnosed with ascites of unknown origin between January 2013 and May 2019 and experienced peritoneal biopsy through TG-NOTES. The outcome measures included diagnostic accuracy and procedure-related adverse events. Results: TG-NOTES was performed successfully in 46 of 51 patients, tuberculous ascites in 38 cases, carcinomatous ascites in 4 cases, cirrhotic ascites in 1 case, and 3 cases showed no obvious abnormalities in pathological result. Five cases failed to be diagnosed because of abdominal adhesions. The diagnostic rate of TG-NOTES was 84.3%. There were no severe procedure-related adverse events and no mortality. All patients had good wound healing and no complaint of discomfort on follow-up. Conclusion: The majority of ascites of unknown origin can be expounded through TG-NOTES combined with biopsy without severe complication, therefore, it is a feasible and safe method to detect the cause of unexplained ascites.

Two undescribed steroids from Munronia pinnata (Wall.) W. Theob.

Two undescribed steroids, named (15 R)-2,15-dihydroxypregna-1,4-dien-3,16-dione (1) and 2,15-dihydroxypregna-1,4,14-trien-3,16-dione (2), were isolated from the aerial parts of Munronia pinnata (Wall.) W. Theob. The structure elucidation of two compounds was performed by using spectroscopic methods and comparing the literature. Compound 2 exhibited inhibitory effect against PTP-1B with an IC50 value of 152.07 ± 3.33 µM, and compound 1 was inactive.

Mechanisms of conservation tillage on nitrogen-fertilizer reduction and maize grain improvement in Mollisols of Northeast China: Insights from a 15N tracing study.

Conservation tillage is an important management practice to guarantee soil fertility in degraded Mollisols. It is still unclear, however, whether the improvement and stability of crop yield under conservation tillage can be sustainable with increasing soil fertility and reducing fertilizer-N application. Based on a long-term tillage experiment initiated in Lishu Conservation Tillage Research and Development Station by Chinese Academy of Sciences, we conducted a 15N tracing field micro-plot experiment to investigate the effects of reducing nitrogen application on maize yield and fertilizer-N transformation under long-term conservation tillage agroecosystem. There were four treatments, including conventional ridge tillage (RT), no-tillage with 0% (NT0), 100% (NTS) maize straw mul-ching, and 20% reduced fertilizer-N plus 100% maize stover mulching (RNTS). The results showed that after a complete cultivation round, the average percentages of fertilizer N recovery in soil residues, crop usage, and gaseous loss were 34%, 50%, and 16%, respectively. Compared with conventional ridge tillage, no-tillage with maize straw mulching (NTS and RNTS) significantly increased the use efficiency of fertilizer N in current season by 10% to 14%. From the perspective of N sourcing analysis, the average percentage of fertilizer N absorbed by crop parts (including seeds, straws, roots, and cobs) to the total N uptake reached nearly 40%, indicating that soil N pool was the main source of N for crop uptakes. In comparison with conventional ridge tillage, conservation tillage significantly increased total N storage in 0-40 cm by reducing soil disturbance and increasing organic inputs, and thus ensured the expansion and efficiency increment of soil N pool in degraded Mollisols. Compared with conventional ridge tillage, NTS and RNTS treatments significantly increased the maize yield from 2016 to 2018. In all, by improving fertilizer nitrogen utilization efficiency and maintaining the continuous supply of soil nitrogen, long-term management of no-tillage with maize straw mulching could achieve a stable and increasing maize yield in three consecutive growing seasons and simultaneously reduce environmental risks derived by fertilizer-N losses, even under the condition of 20% reduction of fertilizer-N application, and thus actualize the sustainable development of agriculture in Mollisols of Northeast China.

Numerical simulation research of the transportation and distribution characteristics on sea surface of the microplastic released continuously for 12 years from China's coastal cities.

Based on the Lagrangian random walk particle tracking method and the global ocean reanalysis data, this study simulated the drift-diffusion process in ocean of microplastic particles (density less than seawater) discharged by coastal cities in China for 12 consecutive years. The results reveal that most of the microplastics (80.33%) essentially end up ashore or in the marginal seas around China, a small portion of microplastics (18.22%) enter the Sea of Japan and the Northwest Pacific Ocean via the Tsushima Strait and the Osumi-Kaikyo with the Kuroshio Tide, a very small portion of microplastics (1.45%) enter into the waters of Southeast Asian countries along with the west boundary current of South China Sea. The concentration distribution characteristics have obvious seasonal variation in the high concentration areas (the marginal seas around China and Sea of Japan). The mainly destination area of microplastics released in different cities is different.

Clinical analysis of 45 cases of perforation were identified during endoscopic retrograde cholangiopancreatography procedure.

Background: Endoscopic retrograde cholangiopancreatography (ERCP) has become an important method to diagnose and treat biliary-pancreatic diseases. Perforations are infrequent but serious complications can occur during ERCPs. However, it is unclear which patients are suitable for surgery and when these patients should receive surgery. Aim: To analyze the outcome of 45 patients with endoscopic retrograde cholangiopancreatography (ERCP) related perforation. Materials and methods: We retrospectively reviewed all 45 patients with ERCP-related perforation between January 2003 and December 2017, and observed the location and causes of perforation, treatment strategies, and mortality. Results: Twenty thousand four hundred and seventy-nine patients received ERCP procedures from January 2003 to December 2017 in our digestive endoscopy center. Forty-five patients suffered from ERCP-related perforations. The incidence rate of ERCP-related perforations was 0.22%. Twenty-six patients suffered from periampullary perforations, 15 patients suffered from duodenal wall perforations, 1 patient suffered from a fundus perforation, 1 patient suffered from a residual gallbladder duct perforation, 1 patient suffered from a papillary diverticulum perforation, and 1 patient suffered from an intrahepatic bile duct perforation. Six patients with duodenal perforations underwent surgery, and the other patients received conservative treatment. One patient with a duodenal perforation and ERCP-related pancreatitis died of heart failure, and all the other patients recovered. The mortality rate was 2.2%. Conclusion: Endoscopic closure is seen as the first method for treating Stapfer type I perforations in the early phase, and surgery is seen as a remedial method when local treatment was failed. The Stapfer type II to type IV perforations can recover by conservative treatment.

Use of rhenium-188 for in vivo imaging and treatment of human cervical cancer cells transfected with lentivirus expressing sodium iodide symporter.

Although survival rates for cervical cancer have improved, they need further improvement in patients with distant metastases. The sodium iodine symporter (NIS) gene has often been used in cancer therapy and imaging. We examined the therapeutic effects of rhenium-188 (188Re) in a cervical cancer xenograft model expressing the NIS gene under the control of the tumor-specific human telomerase reverse transcriptase (hTERT) promoter. We constructed two recombinant lentiviral vectors expressing enhanced green fluorescent protein (eGFP) or the NIS gene driven by the hTERT promoter. To determine the tumor-specific transcriptional activity of the hTERT promoter, the eGFP-expressing vector was stably transfected into tumor cells and normal cells. A cervical cancer HeLa cell line stably expressing NIS (HeLa-TERTNIS) was created and examined in a similar way. HeLa and HeLa-TERTNIS tumor xenografts were transplanted in nude mice, and in vivo 188Re distribution was measured using micro-SPECT/CT imaging. The therapeutic effects of 188Re were assessed over 21 days on the basis of tumor volume and the immunohistochemical findings of excised tumors. eGFP expression controlled by the hTERT promoter was substantially higher in the tumor cells than normal cells. Quantitative PCR and western blotting confirmed that HeLa-TERTNIS cells expressed high levels of NIS mRNA and protein, respectively. Further, 188Re uptake and accumulation were significantly higher in HeLa-TERTNIS cells and xenografts than HeLa cells and xenografts. In vitro and in vivo, 188Re significantly reduced the survival of HeLa-TERTNIS cells and inhibited the growth of HeLa-TERTNIS xenografts, respectively. Immunohistochemical staining showed that HeLa-TERTNIS xenograft tumors expressed higher levels of NIS and caspase-3 and lower levels of Ki-67 than HeLa xenograft tumors. Our findings indicated that hTERT promoter-driven expression of the NIS gene in HeLa cells led to 188Re uptake and therapeutic effects. Thus, NIS-based gene therapy and imaging using the hTERT promoter and 188Re may be possible.

Fragile Sites of 'Valencia' Sweet Orange (Citrus sinensis) Chromosomes Are Related with Active 45s rDNA.

Citrus sinensis chromosomes present a morphological differentiation of bands after staining by the fluorochromes CMA and DAPI, but there is still little information on its chromosomal characteristics. In this study, the chromosomes in 'Valencia' C. sinensis were analyzed by fluorescence in situ hybridization (FISH) using telomere DNA and the 45S rDNA gene as probes combining CMA/DAPI staining, which showed that there were two fragile sites in sweet orange chromosomes co-localizing at distended 45S rDNA regions, one proximally locating on B-type chromosome and the other subterminally locating on D-type chromosome. While the chromosomal CMA banding and 45S rDNA FISH mapping in the doubled haploid line of 'Valencia' C. sinensis indicated six 45S rDNA regions, four were identified as fragile sites as doubled comparing its parental line, which confirmed the cytological heterozygosity and chromosomal heteromorphisms in sweet orange. Furthermore, Ag-NOR identified two distended 45S rDNA regions to be active nucleolar organizing regions (NORs) in diploid 'Valencia' C. sinensis. The occurrence of quadrivalent in meiosis of pollen mother cells (PMCs) in 'Valencia' sweet orange further confirmed it was a chromosomal reciprocal translocation line. We speculated this chromosome translocation was probably related to fragile sites. Our data provide insights into the chromosomal characteristics of the fragile sites in 'Valencia' sweet orange and are expected to facilitate the further investigation of the possible functions of fragile sites.

MiR-18a increased the permeability of BTB via RUNX1 mediated down-regulation of ZO-1, occludin and claudin-5.

The purposes of this study were to investigate the possible molecular mechanisms of miR-18a regulating the permeability of blood-tumor barrier (BTB) via down-regulated expression and distribution of runt-related transcription factor 1 (RUNX1). An in vitro BTB model was established with hCMEC/D3 cells and U87MG cells to obtain glioma vascular endothelial cells (GECs). The endogenous expressions of miR-18a and RUNX1 were converse in GECs. The overexpression of miR-18a significantly impaired the integrity and increased the permeability of BTB, which respectively were detected by TEER and HRP flux assays, accompanied by down-regulated mRNA and protein expressions and distributions of ZO-1, occludin and claudin-5 in GECs. Dual-luciferase reporter assay was carried out and revealed RUNX1 is a target gene of miR-18a. Meanwhile, mRNA and protein expressions and distribution of RUNX1 were downregulated by miR-18a. Most important, miR-18a and RUNX1 could reversely regulate the permeability of BTB as well as the expressions and distributions of ZO-1, occludin and claudin-5. Finally, chromatin immunoprecipitation verified that RUNX1 interacted with "TGGGGT" DNA sequence in promoter region of ZO-1, occludin and claudin-5 respectively. Taken together, our present study indicated that miR-18a increased the permeability of BTB via RUNX1 mediated down-regulation of tight junction related proteins ZO-1, occludin and claudin-5, which would attract more attention to miR-18a and RUNX1 as potential targets of drug delivery across BTB and provide novel strategies for glioma treatment.

Study of a High-Yield Cellulase System Created by Heavy-Ion Irradiation-Induced Mutagenesis of Aspergillus niger and Mixed Fermentation with Trichoderma reesei.

The aim of this study was to evaluate and validate the efficiency of 12C6+ irradiation of Aspergillus niger (A. niger) or mutagenesis via mixed Trichoderma viride (T. viride) culturing as well as a liquid cultivation method for cellulase production via mixed Trichoderma reesei (T. reesei) and A. niger culture fermentation. The first mutagenesis approach was employed to optimize yield from a cellulase-producing strain via heavy-ion mutagenesis and high-throughput screening, and the second was to effectively achieve enzymatic hydrolysis of cellulase from a mixed culture of mutant T. viride and A. niger. We found that 12C6+-ion irradiation induced changes in cellulase biosynthesis in A. niger but had no effect on the time course of the synthesis. It is notable that the exoglucanases (CBH) activities of A. niger strains H11-1 and H differed (6.71 U/mL vs. 6.01 U/mL) and were significantly higher than that of A. niger mutant H3-1. Compared with strain H, the filter paper assay (FPA), endoglucanase (EG) and ß-glucosidase (BGL) activities of mutant strain H11-1 were increased by 250.26%, 30.26% and 34.91%, respectively. A mixed culture system was successfully optimized, and the best ratio of T. reesei to A. niger was 5:1 for 96 h with simultaneous inoculation. The BGL activity of the mixed culture increased after 72 h. At 96 h, the FPA and BGL activities of the mixed culture were 689.00 and 797.15 U/mL, respectively, significantly higher than those of monocultures, which were 408.70 and 646.98 U/mL for T. reesei and 447.29 and 658.89 U/mL for A. niger, respectively. The EG activity of the mixed culture was 2342.81 U/mL, a value that was significantly higher than that of monocultures at 2206.57 U/mL for T. reesei and 1727.62 U/mL for A. niger. In summary, cellulose production and hydrolysis yields were significantly enhanced by the proposed combination scheme.

Opportunistic protozoan diarrhoea.

In the developed world, a significant increase in the incidence of protozoan diarrhoea was observed following the AIDS epidemic. The profound immunodeficiency associated with advanced HIV disease produced increased susceptibility to opportunistic protozoan infections. The resultant profuse diarrhoea, malabsorption and weight loss contributed to the high morbidity and mortality rates associated with the epidemic. The success of highly active antiretroviral therapy (HAART) in suppressing viral replication has led to a reduced incidence of AIDS-related opportunistic infections and this has contributed to decreased morbidity and mortality. In this review, we examine current management practices for HIV-related opportunistic protozoan diarrhoea

[A novel model for visualization of tumor cell-induced angiogenesis in vivo].

The bladder transitional cell carcinoma cell line, BTT739 from the T739 mouse, was transfected with a plasmid that encoded an enhanced green fluorescence protein (GFP) and the cells stably expressing GFP were selected and subcloned. 1 x 10(3)-1 x 10(4) GFP-labeled BTT739 cells were injected under the skin of ear of T739 mice. On day 2-5 post injection, the most interesting manifestations observed were the chemotaxis-like movement of the tumor cells toward the pre-existing host vasculature, host vessel dilation and tortuosity and increased extravasation. On day 10 or later, the sprout from pre-existing host vasculature was observed. Once angiogenesis was triggered on, the tumor cells grew more rapidly and exhibited a specific growth pattern where tumor cells always associated with or surrounded the vessels. The newly formed microvessels always showed heavy extravasation. Immunohistochemistry staining revealed strong VEGF and VEGFR2 (Flk-1) expression in tumor cells. Angiography using Rhodamin-labeled dextran showed neovascularization with unprecedented clarity. However, the tumor mass, even bigger than 2 mm and being neovascularized, shrunk and then disappear in 3-5 days and left only delicated host vessels and recovered extravasation. The evidence from this observation indicated that angiogenesis induced by tumor cells after implantation into the host begins at very early stage. The micrometastases foci could not form or survive without vigorous and continuous angiogenesis. Furthermore, there was active VEGF paracrine and autocrine expression in tumor and high level VEGF secretion by tumor cells plays an important role in initiating angiogenesis and supporting micrometastases.

Baculovirus vector-mediated transfer of sodium iodide symporter and plasminogen kringle 5 genes for tumor radioiodide therapy.

BACKGROUND: Both tumor cells and their supporting endothelial cells should be considered for targeted cell killing when designing cancer treatments. Here we investigated the feasibility of combining radioiodide and antiangiogenic therapies after baculovirus-mediated transfer of genes encoding the sodium iodide symporter (NIS) and plasminogen kringle 5 (K5). METHODS: A recombinant baculovirus containing the NIS gene under control of the human telomerase reverse transcriptase (hTERT) promoter and the K5 gene driven by the early growth response 1 (Egr1) promoter was developed. Dual-luciferase reporter assay was performed to confirm the activation of hTERT transcription. NIS and K5 gene expression were identified by Western blot and Real-Time PCR. Functional NIS activity in baculovirus-infected Hela cells was confirmed by the uptake of 125I and cytotoxicity of 131I. The apoptotic effect of 131I-induced K5 on baculovirus-infected human umbilical vein endothelial cells (HUVECs) was analyzed by a flow cytometry-based assay. In vivo, NIS reporter gene imaging and therapeutic experiments with 131I were performed. Finally, the microvessel density (MVD) in tumors after treatment was determined by CD31 immunostaining. RESULTS: The activation of hTERT transcription was specifically up-regulated in tumor cells. NIS gene expression markedly increased in baculovirus-infected HeLa cells, but not in MRC5 cells. The Hela cells showed a significant increase of 125I uptake, which was inhibited by NaClO4, and a notably decreased cell survival rate by 131I treatment. Expression of the K5 gene induced by 131I was elevated in a dose- and time-dependent manner and resulted in the apoptosis of HUVECs. Furthermore, 131I SPECT imaging clearly showed cervical tumor xenografts infected with recombinant baculovirus. Following therapy, tumor growth was significantly retarded. CD31 immunostaining confirmed a significant decrease of MVD. CONCLUSION: The recombinant baculovirus supports a promising strategy of NIS-based raidoiodide therapy combined with K5-based antiangiogenic therapy by targeting both the tumor and its supporting vessels.

The draft genome of sweet orange (Citrus sinensis).

Oranges are an important nutritional source for human health and have immense economic value. Here we present a comprehensive analysis of the draft genome of sweet orange (Citrus sinensis). The assembled sequence covers 87.3% of the estimated orange genome, which is relatively compact, as 20% is composed of repetitive elements. We predicted 29,445 protein-coding genes, half of which are in the heterozygous state. With additional sequencing of two more citrus species and comparative analyses of seven citrus genomes, we present evidence to suggest that sweet orange originated from a backcross hybrid between pummelo and mandarin. Focused analysis on genes involved in vitamin C metabolism showed that GalUR, encoding the rate-limiting enzyme of the galacturonate pathway, is significantly upregulated in orange fruit, and the recent expansion of this gene family may provide a genomic basis. This draft genome represents a valuable resource for understanding and improving many important citrus traits in the future.

Elevated mucosal addressin cell adhesion molecule-1 expression in acquired immunodeficiency syndrome is maintained during antiretroviral therapy by intestinal pathogens and coincides with increased duodenal CD4 T cell densities.

Reduced intestinal CD4 T cell numbers and gastrointestinal disease are common features of acquired immunodeficiency syndrome (AIDS). Duodenal lymphocyte densities and mucosal addressin cell adhesion molecule (MAdCAM)-1 expression were analyzed in patients with AIDS after highly active antiretroviral therapy (HAART). Compared with human immunodeficiency virus (HIV)-seronegative individuals, HAART-naive patients with AIDS displayed reduced duodenal CD4 T cell densities. After HAART, AIDS patients with opportunistic intestinal pathogens displayed greater increases in duodenal lamina propria (LP) CD4 T cell densities than patients without such infections. Duodenal MAdCAM-1 expression was elevated in all HAART-naive patients with AIDS but remained elevated only in the intestinal pathogen group after HAART. The data suggest that, in HIV-1 infection, lymphocyte migration to the intestine may be promoted by increased MAdCAM-1 expression. After HAART, opportunistic intestinal pathogens maintain elevated MAdCAM-1 expression, which results in prominent increases in LP CD4 T cell densities in the absence of HIV-mediated CD4 T cell destruction.