Doubly guaranteed mechanism for pollination and fertilization in Ipomoea purpurea.

Flowers, the reproductive organs of angiosperms, show a high degree of diversity in morphological structure and flowering habit to ensure pollination and fertilization of the plants. Effect of flower movement on pollination and fertilization was investigated in Ipomoea purpurea (Convolvulaceae) in this study. Fluorescence microscopy was used to observe the germination of pollen grains at different temperatures. From 04:00 to 06:00 h, the stigma was taller than the filaments, so that self-pollination could not occur, and cross-pollination was carried out by insects. Pollen grains germinated rapidly after falling on the stigma; the pollen tube reached the ovule to complete fertilization after 2-3 h. From 07:00 to 09:00 h, filaments of two stamens grew rapidly and reached the same height as the stigma, thus allowing self-crossing. But at this time, the ambient temperature was already high and was not conducive to the germination of pollen grains. The corolla closed, forming an inverted bell shape, where the inner microenvironment ensured completion of pollen germination and fertilization. Preferential cross-pollination and delayed self-crossing of I. purpurea provided a doubly guaranteed mechanism for pollination and fertilization, facilitating its adaptation to a high temperature climate.

[The value of multi-gene testing in benign or malign diagnosis of thyroid nodules with indeterminate cytology].

Objective: To study the diagnostic value of a multi-gene molecular testing in cytologically indeterminate thyroid nodules. Methods: From February 2018 to September 2018, patients with thyroid nodules who underwent fine needle aspiration(FNA) at Peking University Cancer Hospital were enrolled. Three hundred and sixty patients were included, consisting of 86 men and 274 women, with a mean age of 45.8 years (between 13 and 89 years old). Among 391 nodules, 141 were cytologically inderminate and 75 were resected. FNA samples underwent prospective testing using a next-generation sequencing (NGS) assay, which included 16 genes for point mutations and 26 types of gene fusions. The testing results of indeterminate nodules were compared with surgical outcomes, to determine the diagnostic performance. The results were compared with the BRAF V600E single gene mutation analysis by χ(2) test. Results: The multi-gene testing showed a sensitivity of 73.2%, specificity of 96.8%, positive predictive value of 96.8%, and negative predictive value of 73.2%. The diagnostic accuracy of multi-gene testing was significantly higher than the BRAF V600E mutation test (83.3% vs 73.6%, χ(2)=31.588, P<0.01). Conclusion: Multi-gene testing in FNA samples is an effective method to diagnose cytologically indeterminate thyroid nodules, which has a higher accuracy than BRAF V600E mutation detection.

[Fine-needle aspiration for the diagnosis of lymph node metastasis in papillary thyroid carcinoma].

Objective: To investigate the diagnostic performance of fine-needle aspiration (FNA) cytology for the detection of lateral lymph node metastases in patients with papillary thyroid carcinoma (PTC). Methods: A total of 109 lateral lymph nodes with suspicious metastases from 85 patients were retrospectively subjected to FNAC, fine-needle aspiration thyroglobulin measurement (FNATg), and FNATg/SerumTg measurement. Lymph node pathological results after surgery were taken as the gold standard. Using Mann-Whitney U test, Pearson linear model and ROC curve were used for data analysis. Results: The sensitivity, specificity and accuracy of FNATg for the diagnosis of lateral neck lymph node metastasis were respectively 93.7%, 90.0% and 93.3% and those of FNATg/SerumTg were respectively 89.9%, 90.0% and 93.2% respectively, the threshold values for FNATg and FNATg/SerumTg were 0.925 ng/ml and 1.007, respectively. The sensitivity, specificity and accuracy of FNATg combined with FNAC were respectively 91.0%,93.5% and 94.4%. The existence of thyroid tissue and the expression of serum Tg did not affect the expression of lymph node FNATg. The FNATg cutoff value of 0.925 ng/ml showed the best diagnostic performance in patients with a thyroid gland, while the FNATg/SerumTg cutoff ratio of 14.95 showed the best diagnostic performance in patients without a thyroid gland. The serum TgAb significantly interfered with the expression of FNATg in the lateral neck metastatic lymph nodes (P=0.049). Conclusions: FNATg alone or the combination of FNATg with FNAC are highly reliable in the diagnosis of lateral neck lymph node metastases in patients with PTC. The expression of TgAb may interfere with the accuracy of the diagnostic performance of FNATg.

Low-expression of lncRNA FER1L4 might be a prognostic marker in osteosarcoma.

OBJECTIVE: To investigate the potential role of Long non-coding RNA (lncRNA) FER1L4 in the diagnosis and prognostic assessment of osteosarcoma. PATIENTS AND METHODS: LncRNA FER1L4 expression in osteosarcoma samples was detected by real-time PCR. The Kaplan-Meier method was used to analyze the relationship between lncRNA FER1L4 expression and the survival time of patients. RESULTS: LncRNA FER1L4 expression was decreased in osteosarcoma samples. LncRNA FER1L4 was not related to the gender and age of patients, but was significantly associated with disease stage, metastasis, and tumor differentiation. CONCLUSIONS: Low-expression of lncRNA FER1L4 might be a prognostic marker in osteosarcoma.

[Risk factors of hypoparathyroidism following total or near total thyroidectomy].

OBJECTIVE: To study the risk factors for postoperative hypoparathyroidism or hypocalcemia. METHODS: Totally 414 patients with thyroid diseases who underwent total or near total thyroidectomy at Department of Head and Neck Surgery, Peking University Cancer Hospital and Institute from June 2007 to June 2014 were studied retrospectively. There were 119 male and 295 female patients with a median age of 47 years. The clinical and pathological features that related to post-operative hypoparathyroidism were studied by χ(2) test and multivariate Logistic regression analysis. RESULTS: Of the 414 patients, 36.2% developed transient hypocalcemia, 36.5% developed transient hypoparathyroidism, 2.2% developed permanent hypoparathyroidism. In regression analysis, unilateral or bilateral center lymph node dissection were associated with mild transient hypocalcemia after surgery (OR=2.366, P=0.022; OR=5.216, P=0.000); unilateral or bilateral center lymph node dissection as well as surgical options were significant risk factors for severe transient hypocalcemia (OR=4.029, P=0.001; OR=8.384, P=0.000; OR=2.073, P=0.017) and hypoparathyroidism (OR=1.755, P=0.040; OR=4.144, P=0.000; OR=2.287, P=0.000). The parathyroid hormone concentration on postoperative day 1 was an independent risk factor for permanent hypoparathyroidism (OR=2.011, P=0.014). The concentration of parathyroid hormone threshold <5.28 ng/L was a predictor to permanent hypoparathyroidism with accuracy of 95.0%. CONCLUSIONS: Bilateral center lymph node dissection is a risk factor of permanent hypoparathyroidism in patients received total thyroidectomy should be taken thoughtfully. The parathyroid hormone concentration on postoperative day 1 provides better prediction for persistent hypoparathyroidism.

Stereotactic radiosurgery for the treatment of mesial temporal lobe epilepsy.

OBJECTIVES: Stereotactic radiosurgery (RS) is a potential option for some patients with temporal lobe epilepsy (TLE). The aim of this meta-analysis was to determine the pooled seizure-free rate and the time interval to seizure cessation in patients with lesions in the mesial temporal lobe, and who were eligible for either stereotactic or gamma knife RS. MATERIALS & METHODS: We searched the Medline, Cochrane, EMBASE, and Google Scholar databases using combinations of the following terms: RS, stereotactic radiosurgery, gamma knife, and TLE. RESULTS: We screened 103 articles and selected 13 for inclusion in the meta-analysis. Significant study heterogeneity was detected; however, the included studies displayed an acceptable level of quality. We show that approximately half of the patients were seizure free over a follow-up period that ranged from 6 months to 9 years [pooled estimate: 50.9% (95% confidence interval: 0.381-0.636)], with an average of 14 months to seizure cessation [pooled estimate: 14.08 months (95% confidence interval: 11.95-12.22 months)]. Nine of 13 included studies reported data for adverse events (AEs), which included visual field deficits and headache (the two most common AEs), verbal memory impairment, psychosis, psychogenic non-epileptic seizures, and dysphasia. Patients in the individual studies experienced AEs at rates that ranged from 8%, for non-epileptic seizures, to 85%, for headache. CONCLUSION: Our findings indicate that RS may have similar or slightly less efficacy in some patients compared with invasive surgery. Randomized controlled trials of both treatment regimens should be undertaken to generate an evidence base for patient decision-making.

Effects of silicon on seed setting rate of rice intersubspecific hybrids.

The present study found semi-sterility in rice intersubspecific hybrids of 'Taichung 65' x 'Guangluai 4' and 'Ludao' x 'Qiuguang'. Embryo sac fertility was evaluated using the overall staining transparent method. The results showed that the embryo sac contained a normal egg cell, normal synergid cells, polar nuclei cells, and antipodal cells, indicating that semi-sterility was caused mainly by pollen semi-sterility. In the pot experiment, the effects of silicon on the seed-setting rate of the two intersubspecific hybrids were examined. The results showed that the rate of anther dehiscence, number of pollen per stigma of Fl plants, potential of pollen grain germination, and fertility of the spikelet were significantly improved by the utilization of silicon fertilizer.

Analysis of specific sequences in mutant rice generated by introduction of exogenous corn DNA.

Rice variation induced by the introduction of exogenous DNA has become an important method of improving rice varieties and creating new germplasms. In this study, we transferred maize genomic DNA fragments to the receptor of Nipponbare rice using a modified "pollen-tube pathway" method. Material from mutant rice B1 and B2 were acquired and 14 specific bands were obtained from the material using amplified fragment length polymorphism analysis. From the 14 specific sequences obtained, there were 3791 bp, including 144 base mutations with a base mutation rate of 3.80%. Specific bands resulted from base mutation of selective bases or restriction endonuclease recognition sequences, or insertion or deletion of DNA fragments. The frequency of single-base mutations was significantly higher than that of double-base mutations, three-sequential base mutations, and multiple-sequential base mutations. The site frequency of base substitution (87.04%) was significantly higher than that of base insertion (3.70%) or deletion (9.26%). In all cases of base substitution, the frequency of transition (76.47%) was significantly higher than transversion (23.53%). The above results indicate that transferring foreign-species DNA into rice cells can induce base mutations in the receptor, with base substitutions occurring at the highest frequency, and the dominant type of base substitutions being transition. Preliminary analysis reveals that the molecular mechanism of transferring exogenous DNA into rice causes mutations, which provides theoretical data on biological mutagenesis for further research.

Bortezomib inhibits C2C12 growth by inducing cell cycle arrest and apoptosis.

Proteosome inhibitors such as bortezomib (BTZ) have been used to treat muscle wasting in animal models. However, direct effect of BTZ on skeletal muscle cells has not been reported. In the present study, our data showed that C2C12 cells exhibited a dose-dependent decrease in cell viability in response to increasing concentrations of BTZ. Consistent with the results of cell viability, Annexin V/PI analysis showed a significant increase in apoptosis after exposing the cells to BTZ for 24h. The detection of cleaved caspase-3 further confirmed apoptosis. The apoptosis induced by BTZ was associated with reduced expression of p-ERK. Cell cycle analysis revealed that C2C12 cells underwent G2/M cell cycle arrest when incubated with BTZ for 24h. Furthermore, BTZ inhibited formation of multinucleated myotubes. The inhibition of myotube formation was accompanied by decreased expression of Myogenin. Our data suggest that BTZ induces cell death and inhibits differentiation of C2C12 cells at clinically relevant doses.

Fabrication of nickel nanocontacts using nanostencils and electron beam assisted SiO2 deposition.

Nickel nanocontacts for studying ballistic magnetoresistance have been fabricated by sputtering through FIB prepared nanostencil masks and by using electron beam assisted deposition of SiO2 to reduce the size of FIB milled pores through silicon nitride membranes. These two methods are discussed in terms of the nanocontact sizes, fabrication, and yield. The smallest size of the nanocontacts prepared using the nanostencil method was 40 nm and by the filling method was 1-2 nm. The maximum magnetoresistance measured was 1% and no evidence of a large ballistic magnetoresistance was observed.

Small epithelial cells in human liver cirrhosis exhibit features of hepatic stem-like cells: immunohistochemical, electron microscopic and immunoelectron microscopic findings.

AIMS: To investigate whether cells with features similar to those of the oval cells of rodents and the small epithelial cells (SEC) recently described in certain human liver diseases, i.e. hepatic progenitor cells, also occur in human liver cirrhosis. METHODS AND RESULTS: Surgical specimens from 35 cases of hepatitis B virus-positive cirrhosis (30 cases containing hepatocellular carcinoma) were investigated by immunohistochemical staining for cytokeratin 7 and albumin. Electron microscopic investigations, and immunoelectron microscopic investigations using the same antibodies and a double-labelling technique were performed in 15 and seven cases, respectively. SEC were observed in proliferated bile ductules, at the margins of regenerating nodules and in the fibrous septa in all cases of cirrhosis. The SEC were morphologically similar to the SEC described previously, and to the oval cells seen in experimental hepatocarcinogenesis. They were characterized by their small size, oval shape, scanty electron-dense or electron-lucent cytoplasm, a high nucleo-cytoplasmic ratio, tonofilaments and intercellular junctions. Immunoelectron microscopy revealed that the SEC co-expressed cytokeratin 7 and albumin. Both relatively undifferentiated SEC and SEC with morphological and immunophenotypical signs of differentiation towards biliary epithelial cells and hepatocytes were found. CONCLUSIONS: SEC that exhibit morphological and immunophenotypical features of the SEC seen in certain other liver diseases are found in cirrhosis. These findings further support the hypothesis that a bipotent hepatic stem cell that may give rise to biliary epithelial cells and hepatocytes exists in the human liver.

Characterization of the biosynthetic gene cluster for the oligosaccharide antibiotic, Evernimicin, in Micromonospora carbonacea var. africana ATCC39149.

Evernimicin (EV) belongs to the orthosomycin class of antibiotics and consists of several modified L- and D-deoxysugars containing unusual orthoester and glycosyl linkages and two orsellinic acid groups, one that is halogenated. The EV biosynthetic gene cluster from Micromonospora carbonacea var. africana ATCC39149 was localized by hybridization to a dTDP-D-glucose 4,6-dehydratase probe and a 120-kb region containing the EV biosynthetic cluster and surrounding regions has been sequenced. BLAST analysis has identified a type I polyketide synthase for orsellinic acid biosynthesis as well as enzymes required for L- and D-deoxyglucose and D-deoxymannose synthesis. In addition, genes involved in glycosyltransfer and resistance were identified. Insertional mutations in several biosynthetic genes blocked EV production, indicating a role for these genes in EV biosynthesis.

Indirect neurotrophic effect of neuropeptide ZNC(C)PR on PC12 cells via peptide-stimulation of C6 cells.

AIM: To understand the mechanism of neurotrophic action of neuropeptide ZNC(C)PR and its effect on which could affect both growth and apoptosis of C6 cells. METHODS: Effects of ZNC(C)PR-treated C6 conditioned medium was observed on on culture of PC12 cells. The development of PC12 cells was determined by ratio of neurite-bearing cells in the total cells. The specific binding of ZNC(C)PR on C6 cells was determined by radioligand binding assay (RBA). RESULTS: ZNC(C)PR-treated C6 conditioned medium increased the ratio of neurite-bearing PC12 cells by 36% compared to the untreated C6 conditioned medium or to a mixture of ZNC(C)PR with the untreated C6 conditioned medium. RBA showed a specific binding site of ZNC(C)PR on C6 cells with Kd value of 2.74 nmol.L-1 and Bmax value of 19 pmol.g-1 protein. CONCLUSION: ZNC(C)PR enhanced C6 cells induced secretion of some neurotrophic factors which acted as enhancers for PC12 cells differentiation, through its specific receptor sites on the neuroglioma cell.

[Effect of AVP(4-8) administration on Ca2+/CaM-dependent protein kinase II autophosphorylation in rat brain].

The extent increase of Ca2+/CaM-dependent protein kinase II (CaMK II) autophosphorylation in various brain regions of rat reached a maximum value, one hour after s.c. administration of AVP(4-8). The increase in the cortex amounted to 192% of the control (P < 0.001), while in the hippocampus only 40% (P < 0.05). The autophosphorylation of CaMK II was dependent on both Ca2+ and CaM. Western blotting with anti-CaMK II alpha monoclonal antibody showed that the content of CaMK II alpha in cortex did not show detectable change in 1 h as compared to the control group. ZDC(C)PR, an antagonist of AVP(4-8), markedly blocked the effect of AVP(4-8), suggesting that AVP (4-8) stimulated CaMK II autophosphorylation is mediated through its receptor.

Pulsed-accelerated-flow spectrometer with position-resolved observation.

The title instrument (PAF-PRO) permits the progress of rapid reactions to be monitored at 128 positions along a 2 cm observation cell as reactants flow down the cell. A decelerated push is used to give velocity changes from 21 to 2 m s(-1) during a time interval of 384 ms. Variation of flow velocity allows reaction rate constants to be resolved from the physical mixing process. The flow system brings the reacting solutions together in a 10-jet radial mixer 0.32 cm before the mixture enters the observation tube (0.203 cm width, 1.945 cm length). A masked charge-coupled device (CCD) is the array detector used to obtain transmittance data as a function of position and velocity. The masked portion of the CCD serves as a dynamic memory buffer for fast data acquisition. Pseudo-first-order rate constants are measured from 200 to 12 000 s(-1). The instrument also is calibrated for second-order reactions (equal concentrations) with initial half-lives of 0.3-1.5 ms. Applications of the PAF-PRO system for the study of fast multistep reactions are presented.

ZNC(C)PR affects developmental changes of P46 phosphorylation in rat hippocampus.

Protein phosphorylation has been suggested to be correlated with brain development and with the molecular mechanism of behavioral effects of neuropeptides. The present study reports in vitro endogenous phosphorylation of P46, a membrane-associated protein that is changed during development of the rat hippocampus. This study indicated that the degree of endogenous phosphorylation may be correlated with the establishment of synaptic connections. Interestingly, P46 was proved to be identical to a well-known growth-associated protein B-50/GAP-43 in its identical apparent molecular weight, isoelectric point, phosphorylation dependence, and the cross immunoreaction of monoclonal anti-B-50/GAP-43 antibody and P46. Moreover, neonatal administration of neuropeptide ZNC(C)PR could facilitate the developmental progress of P46 endogenous phosphorylation. It is suggested that the changes in P46 phosphorylation could be involved in the cellular mechanism of ZNC(C)PR behavioral effects on learning.