MicroRNAs: A novel signature in the metastasis of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a malignant epithelial tumor, characterized by squamous cell differentiation, it is the sixth leading cause of cancer-related deaths globally. The increased mortality rate of ESCC patients is predominantly due to the advanced stage of the disease when discovered, coupled with higher risk of metastasis, which is an exceedingly malignant characteristic of cancer, frequently leading to a high mortality rate. Unfortunately, there is currently no specific and effective marker to predict and treat metastasis in ESCC. MicroRNAs (miRNAs) are a class of small non-coding RNA molecules, approximately 22 nucleotides in length. miRNAs are vital in modulating gene expression and serve pivotal regulatory roles in the occurrence, progression, and prognosis of cancer. Here, we have examined the literature to highlight the intimate correlations between miRNAs and ESCC metastasis, and show that ESCC metastasis is predominantly regulated or regulated by genetic and epigenetic factors. This review proposes a potential role for miRNAs as diagnostic and therapeutic biomarkers for metastasis in ESCC metastasis, with the ultimate aim of reducing the mortality rate among patients with ESCC.

[Effects of row spacing and sowing rate on vertical distribution of photosynthetically active radiation, biomass, and grain yield in winter wheat canopy.]

To clarify the effects of row spacing and sowing rate on the vertical distribution of canopy PAR, biomass, and grain yield in winter wheat, a field experiment was conducted without increa-sing water and fertilizer input. There were two row spacing modes, R₁ (equal spacing, 20 cm+20 cm) and R₂(wide and narrow row spacing, 12 cm+12 cm+12 cm+24 cm), and three sowing rates, D₁ (low, 120 kg·hm^-2), D₂ (medium, 157.5 kg·hm^-2), D₃ (high, 195 kg·hm^-2). The canopy photosynthetically active radiation (PAR) interception and utilization rate in different heights, population photosynthetic capacity, biomass, and grain yield were measured during the main growth stages of winter wheat. The results showed that both total PAR interception and upper layer PAR interception of winter wheat canopy under R₁ treatment were significantly higher than those in R₂ treatment, but those of the middle layer and lower layer were higher in R₂ than in R₁, and with significant difference in the middle layer. From flowering to maturity, the photosynthetic potential (LAD), population photosynthetic rate (CAP), PAR conversion rate, and utilization rate in R₂ were all significantly higher than those in R₁ under the same sowing rate, with the highest value under R₂D₂ treatment. With the increasing sowing rate, the population biomass (BA) and leaf biomass (BL) at different layers increased, but the individual biomass (BP) showed an opposite trend. Under the same sowing rate, BA, BL and BP in R₂ were higher than that in R₁ after the flowering stage. Among them, BA and BP had significant difference in row spacing treatments at the maturity stage, with significant difference between the two row spacing treatments being observed in BL of the middle and lower layers under D₂ and D₃ sowing rates. The spike number, grain number per spike, 1000-kernel weight, and grain yield of winter wheat among different treatments were the highest in R₂D₃, R₂D₁, R₂D₁, and R₂D₂, respectively. The 1000-kernel weight, grain number per spike and grain yield in R₂ treatment were significantly higher than R₁. In summary, the PAR interception in the middle and lower layers of winter wheat canopy was improved by changing row spacing, with positive consequence on the photosynthetic capacity of individual plant and population, PAR utilization and transformation efficiency, which finally increased biomass and grain yield. Therefore, optimizing the field structure and shaping the ideal population photosynthetic structure should pay more attention during the high-yield cultivation of winter wheat. Making full use of light resources per unit land area and excavating the photosynthetic production potential of crops were also critical to achieve high yield and efficiency. In this experiment, the population photosynthetic capacity, photosynthetic effective radiation utilization rate, and yield were the highest under the treatment of R₂D₂.

The effect-enhancing and toxicity-reducing activity of Hypericum japonicum Thunb. extract in murine liver cancer chemotherapy

Chinese herbs are potential sources of antitumor drugs with immunoregulatory activity and few adverse effects. In the present study, we investigated whether the Hypericum japonicum Thunb. (HJT) extract enhanced the efficacy of 5-fluorouracil (5-FU) treatment in murine liver tumor xenografts and reduced toxicity of chemotherapy in hepatoma H22-bearing mice. Tumor weight and inhibition rate, thymus and spleen indices, as well as white blood cell (WBC) count were calculated. The phagocytic function of macrophages was assessed by observing peritoneal macrophages phagocytized chicken red blood cells (RBC). Body weight and toxic reactions of the chemotherapeutic and life prolongation rate were investigated in the mice. Results demonstrated that the HJT extract significantly enhanced the tumor inhibition rate of 5-FU, improved the immune function, reduced the toxic effects and prolonged the survival time in the tumor-bearing mice. Taken together, these results indicated that the HJT extract has a synergistic tumor-inhibiting effect with 5-FU, is able to reduce the toxic side effects and is likely to be safe and efficacious for use in antitumor therapy.

[Genetic diversity of starch synthesis genes of Chinese maize (Zea mays L.) with SNAPs]

Analysis of genetic diversity in maize populations is a very important step for understanding genetic structure and subsequently for genetic manipulations in maize breeding. Sh2, Bt2, Sh1, Wx1, Ae1 and Su1 involved in starch biosynthesis are important genes associated with yield and quality traits in maize breeding programs. In this study, genetic diversity of these six genes in 67 Chinese elite maize inbred lines was measured using single-nucleotide amplified polymorphisms (SNAPs). The results indicated that the number of haplotypes of each gene and population was far less than theoretically expected 2(n) (n = the number of the SNAPs). Phenetic clustering analysis showed that the kernel phonetic (semi-) dent and (semi-) flint lines were belong to distinct subclusters based on haplotypes of SNAPs, with a few exceptions. In addition, the genetic origin of these maize inbred lines was associated with the clustered subgroups. Intragenic linkage disequilibrium (LD) was observed in some of the SNAPs in Bt2, Sh1 and Ae1, while intergenic LD was observed in some of the SNAPs in Bt2, Sh1 and Su1. Association study of kernel phenotypes and SNAP haplotypes showed that the (semi-) dent and (semi-) flint lines had the common haplotype of TA and CC at two SNAP sites in Bt2 (Bt2-2 and Bt2-5), respectively. Two haplotypes of ATGT and GTGC at four SNAP sites in Sh1 (Sh1-2, Sh1-3, Sh1-4 and Sh1-5) were associated with temperature and tropical origin of the maize inbred lines, respectively.

Antidiabetic effect of Oenanthe javanica flavone

AIM

To study the antidiabetic effect of Oenanthe javanica flavone (OjF).

METHODS

Mice were injected i.v. with alloxan 90 mg.kg-1 to induce diabetes. Blood glucose, serum lipid, and pancreatic amylase were determined with Automatic Biochemistry Analysor. Serum insulin was determined by radioimmunoassay. The pancreas and islets were examined under microscope.

RESULTS

OjF 200 mg.kg-1 reduced the blood glucose in normal mice from 0.5 to 6 h after a single administration ig. OjF 200 and 400 mg.kg-1 ig daily for 10 d decreased the blood glucose in alloxan-induced hyperglycemic mice (P < 0.05, P < 0.01). OjF promoted the release of insulin both in normal and in diabetic mice. OjF decreased serum triglyceride and raised the lowered pancreatic amylases in diabetic mice (P < 0.01, P < 0.01). The islet-injured changes of OjF-treated group were similar to those of control in histology examination, but to a lesser degree.

CONCLUSION

OjF possessed the hypoglycemic and hypotriglyceride actions, mainly concerned with promoting release of insulin from B-cells in islets of langerhans.

Group I secreted PLA2 and arachidonic acid metabolites in the maintenance of cat LES tone

Spontaneous tone of in vitro lower esophageal sphincter (LES) circular muscle is associated with elevated levels of arachidonic acid (AA), PGF(2alpha), and increased [35S]guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS) binding to Gq-, Gi3-, and G(i1/i2)-like G proteins. Tone and AA levels were reduced by inhibitors of a pancreatic-like (group I) secreted phospholipase A2 (sPLA2), by the cyclooxygenase inhibitor indomethacin, and by the thromboxane A2 antagonist SQ-29548. In addition, pertussis toxin (PTX) reduced LES tone, confirming a role of PTX-sensitive G proteins in maintenance of LES tone. PGF(2alpha) contracted LES smooth muscle (strips and cells) and increased [35S]GTPgammaS binding to Gq and Gi3 in solubilized LES circular muscle membranes. PGF(2alpha)-induced contraction of LES permeable muscle cells was inhibited by Gq and Gi3 but not by G(i1/i2) and Go antibodies. The thromboxane A2 analog U-46619 contracted LES smooth muscle and increased Gq binding. U-46619-induced contraction was inhibited by Gq but not by Gi3, G(i1/i2), and Go antibodies. LES tone and [(35)S]GTPgammaS binding were significantly reduced by indomethacin. We conclude that group I sPLA2 may mediate "spontaneous" LES tone by producing AA, which is metabolized to PGF(2alpha) and thromboxane A2. These AA metabolites activate receptors linked to Gi3 and Gq to maintain LES contraction.

Inhibition of nitric oxide synthesis increases the secretion of endothelin-1 in vivo and in cultured endothelial cells

The aim of this study is to investigate the effects of nitric oxide, formed from L-arginine, on the production of endothelin-1 in vivo and in cultured endothelial cells. In mechanically ventilated anesthetized dogs (n = 5), mean pulmonary arterial pressure (PAPm) and pulmonary vascular resistance (PVR) during hypoxic ventilation (FIO2 = 0.10) was 25 +/- 3.1 kPa and 68.7 +/- 10.2 kPa.s/L respectively. NG-nitro-L-arginine methylester (L-NAME), an inhibitor of nitric oxide synthase, increased the peak value of PAPm and PVR during hypoxic ventilation to 36.6 +/- 4.7 kPa and 158.4 +/- 25 kPa.s/L and its effect lasted for 2-3 hours. Meanwhile, plasma endothelin-1 level in the femoral artery increased by 20.9 +/- 7.1, 25.6 +/- 7.7, 28.6 +/- 7.9 pg/ml at the 60th, 120th, 180th minute after the injection of L-NAME respectively (P < 0.05 vs hypoxic control before the injection). In cultured endothelial cells from umbilical veins, endothelin-1 level of culture medium in control group was 35.1 +/- 5.9 pg/10(5) cells/ml (n = 9). L-NAME increased endothelin-1 level to 42.8 +/- 4.9pg/10(5) cells/ml (n = 9, P < 0.05) in case of 10(-11) mol/L and to 43.0 +/- 4.7 pg/10(5) cells/ml in case of 10(-7) mol/L (n = 9, P < 0.05). These findings indicate that endogenous nitric oxide is an inhibitory modulator of hypoxic pulmonary vasoconstriction and that nitric oxide inhibits the production of endothelin-1 in vivo and in cultured vascular endothelial cells.

[Pulmonary nocardia infection]

Four cases of pulmonary Nocardia infection were reported and the 22 cases reported in our country between 1980 and 1993 were analyzed together for the purpose of revealing the clinical picture of this disease in China. There was approximately a ratio of two male patients to one female (18:8) with a mean age of 40 years in this series of patients. Various underlying diseases were found as predisposing factors in 69% (18/26) of the cases. 34.5% (9/26) of the cases had a history of corticosteroid therapy. Pleural effusion was identified in 50% (13/26) of the patients. 38% (10/26) of the patients died. Patients with primary pulmonary Nocardia infection had a better prognosis than those with secondary infection. Appropriate culture media, sufficient culture time and repeated cultures were recommended to improve the positive identification rate of this special causative agent. The sulfonamides were the drugs of first choice along with prompt drainage of thoracic empyema and abscess.

[Inhibition of endogenous nitric oxide synthesis enhances acute hypoxic pulmonary vasoconstriction]

The objective of this study was to observe the role of endogenous nitric oxide, formed from L-arginine, in the regulation of acute hypoxic pulmonary vasoconstriction by inhibiting its synthesis with the false substrate NG-nitro-L-arginine methyl ester (L-NAME) in anesthetized dogs. L-NAME (1 mg/kg, 5 mg/kg, 15 mg/kg) significantly increased the mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) during hypoxic ventilation (FiO2 = 0.10) and its action lasted for 90-180 minutes. The maximum increase value (MIV) of hypoxic mPAP in three groups (4 dogs each group) is 1.1 +/- 0.2, 1.5 +/- 0.3, 1.6 +/- 0.4 kPa (1 kPa = 7.5 mmHg), respectively, while that of hypoxic PVR is 58.4 +/- 15.6, 99.3 +/- 28.8, 78 +/- 4.0 kPa.s/L (all P < 0.05 vs hypoxic control before the injection). The increase percent of hypoxic mPAP and PVR induced by L-NAME (15 mg/kg) was 45.23 +/- 5.78% and 133.2 +/- 35.22% 30 minutes after the injection, which was more remarkable than that of mPAP and PVR (18.83 +/- 5.63%, 84.13 +/- 22.67%, respectively) by L-NAME (1 mg/kg). L-arginine (0.5 g/kg) reversed the effect of L-NAME (5 mg/kg) on mPAP and PVR at hypoxic ventilation within one hour. L-NAME also markedly increased hypoxic mean arterial blood pressure at the dose of 15 mg/kg (MIV 2.7 +/- 0.7 kPa) and systemic vascular resistance at the three separate doses (MIV 354.4 +/- 99.7, 456.2 +/- 105, 361.5 +/- 70 kPa x s/L, respectively), meanwhile it remarkably decreased cardiac output and heart rate during hypoxia.(ABSTRACT TRUNCATED AT 250 WORDS)