Characterization and bioactivity of A-type procyanidins from litchi fruitlets at different degrees of development.

Characterization and bioactivity of A-type procyanidins was investigated in litchi fruitlet (LF) at different stages and mature pericarp (MP) of 5 litchi cultivars. The content of total phenols in LFs was higher than that of MP and showed good antioxidant activity. Eleven procyanidins were identified in samples, including procyanidin A2, procyanidin A4, and 1 dimer, 2 trimers, and 1 tetramer of A-type procyanidin. Also, A-type procyanidin could stably exist in LFs stage, but declined substantially after maturity, which was about 1.45 - 3.56 times than mature pericarp. In addition, the second stage of LFs showed strong anti-inflammatory and anti-proliferative activities, in which monomer and A-type procyanidin trimers in LFs were significantly correlated with antioxidant (r > 0.72; p < 0.01) and anti-inflammatory (r = 0.53; p < 0.05) activities, respectively. Therefore, litchi in LF stage could be a good source of A-type oligomer procyanidins which had good application value.

Lambert-Eaton myasthenia syndrome: specified description of a response pattern to low-frequency repetitive nerve stimulation.

OBJECTIVE: We aimed to specify and quantify the characteristics of the decrement in low-frequency repetitive nerve stimulation response in Lambert-Eaton myasthenia syndrome (LEMS) and compare it to those of myasthenia gravis (MG). PATIENTS AND METHODS: We retrospectively reviewed 18 patients with LEMS and 24 patients with MG. Ten consecutive stimulations were applied at 3 Hz to the abductor pollicis brevis. We determined the position of the smallest wave in the stimulation sequence, and we calculated the decrement and recovery. RESULTS: The median sequential order of the minimum wave was 8 in the LEMS group and 5 in the MG group (p < 0.001). The median decrement in the LEMS group was 36.7%, while that in the MG group was 21.0% (p = 0.047). The recovery percentage was 1.4% in the LEMS group and 3.5% in the MG group (p = 0.001). The area under the curve for the sequential order of the minimum wave was 0.90, and the reciprocal optimum cut-off point was 6.5. CONCLUSIONS: We elucidated a pattern with a delayed nadir and subsequent poor recovery, featuring a low-frequency decrement; furthermore, we determined the most likely sequential order of the minimum wave in patients with LEMS, and the indicator was useful for differentiation.

Arabidopsis RAD23B regulates pollen development by mediating degradation of KRP1.

The ubiquitin (Ub)/26S proteasome system (UPS) plays a key role in plant growth, development, and survival by directing the turnover of numerous regulatory proteins. In the UPS, the ubiquitin-like (UBL) and ubiquitin-associated (UBA) domains function as hubs for ubiquitin-mediated protein degradation. Radiation sensitive 23 (RAD23), which has been identified as a UBL/UBA protein, contributes to the progression of the cell cycle, stress responses, ER proteolysis, and DNA repair. Here, we report that pollen development is arrested at the microspore stage in a rad23b null mutant. We demonstrate that RAD23B can directly interact with KIP-related protein 1 (KRP1) through its UBL-UBA domains. In addition, plants overexpressing KRP1 have defects in pollen development, which is a phenotype similar to the rad23b mutant. RAD23B promotes the degradation of KRP1 in vivo, which is accumulated following treatment with the proteasome inhibitor MG132. Our results indicate that RAD23B plays an important in pollen development by controlling the turnover of the key cell cycle protein, KRP1.

Correlation between methylenetetrahydrofolate reductase gene polymorphism and oligoasthenospermia and the effects of folic acid supplementation on semen quality.

BACKGROUND: The present study investigated the correlation between 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and oligoasthenospermia, as well as the effects of folic acid supplementation on semen quality. METHODS: The present study was a case control study. The PCR-chip assay was applied to analyze the distribution characteristics of the frequencies and genotypes of the MTHFR C677T allele in 167 Han Chinese patients with idiopathic male infertility (including 86 patients with oligospermia and 81 patients with asthenospermia) and in 78 males with normal semen parameters. Moreover, homocysteine (Hcy) levels were assessed for the different groups. Semen quality was measured following three months of folic acid supplementation for the oligospermia and asthenospermia groups. RESULTS: The cytosine-thymine (CT) genotype (50% vs. 39.5%) and the thymine-thymine (TT) genotype (51.2% vs. 7.7%) carriers in the oligospermia group exhibited significantly higher percentages compared with those of the control group. The percentage of the CT genotype carriers in the asthenospermia group was significantly higher compared with that of the control group (59.3% vs. 50%), while the frequency of the TT genotype was significantly increased (22.2% vs. 7.7%). Furthermore, serum Hcy levels in the oligospermia and asthenospermia groups were significantly higher compared with those of the control group. The data also demonstrated that sperm density increased significantly following three months of folic acid supplementation to patients with oligospermia or asthenospermia. In these patients, the highest increase was noted for the subjects carrying the TT genotype. CONCLUSIONS: The MTHFR C677T mutation and the elevated Hcy levels are important risk factors for the development of oligoasthenospermia. Folic acid supplementation can significantly improve sperm density.

Inhibition of Migration and Invasion of Hepatocarcinoma HepG2 Cells by Dietary Saponins via Targeting HIF-1α.

BACKGROUND: Different saponins from herbs have been used as tonic or functional foods, and for treatment of various diseases including cancers. Although clinical data has supported the function of these saponins, their underlying molecular mechanisms have not been well defined. METHODS: With the simulated hypoxia created by 8 hours of Cu++ exposure and following 24 hour incubation with different concentration of saponins in HepG2 cells for MTT assay, migration and invasion assays, and for RT-PCR, and with each group of cells for immunofluorescence observation by confocal microscopy. Results：ZC-4 had the highest rate of inhibition of cell proliferation by MTT assay, and the highest inhibition of migration rate by in vitro scratch assay, while ZC-3 had the highest inhibition of invasion ratio by transwell assay. Under the same simulated hypoxia, the molecular mechanism of saponin function was conducted by measuring the gene expression of Hypoxia Inducible Factor (HIF)-1α through RT-PCR, in which ZC-3 showed a potent inhibition of gene HIF-1α. For the protein expression by immunofluorescence staining with confocal microscopy, HIF-1α was also inhibited by saponins, with the most potent one being ZC-4 after eight hours' relatively hypoxia incubation. CONCLUSION: Saponins ZC-4 and ZC-3 have the potential to reduce HepG2 cell proliferation, migration and invasion caused by hypoxia through effectively inhibiting the gene and protein expression of HIF-1α directly and as antioxidant indirectly.

Long term stability of nanowire nanoelectronics in physiological environments.

Nanowire nanoelectronic devices have been exploited as highly sensitive subcellular resolution detectors for recording extracellular and intracellular signals from cells, as well as from natural and engineered/cyborg tissues, and in this capacity open many opportunities for fundamental biological research and biomedical applications. Here we demonstrate the capability to take full advantage of the attractive capabilities of nanowire nanoelectronic devices for long term physiological studies by passivating the nanowire elements with ultrathin metal oxide shells. Studies of Si and Si/aluminum oxide (Al2O3) core/shell nanowires in physiological solutions at 37 °C demonstrate long-term stability extending for at least 100 days in samples coated with 10 nm thick Al2O3 shells. In addition, investigations of nanowires configured as field-effect transistors (FETs) demonstrate that the Si/Al2O3 core/shell nanowire FETs exhibit good device performance for at least 4 months in physiological model solutions at 37 °C. The generality of this approach was also tested with in studies of Ge/Si and InAs nanowires, where Ge/Si/Al2O3 and InAs/Al2O3 core/shell materials exhibited stability for at least 100 days in physiological model solutions at 37 °C. In addition, investigations of hafnium oxide-Al2O3 nanolaminated shells indicate the potential to extend nanowire stability well beyond 1 year time scale in vivo. These studies demonstrate that straightforward core/shell nanowire nanoelectronic devices can exhibit the long term stability needed for a range of chronic in vivo studies in animals as well as powerful biomedical implants that could improve monitoring and treatment of disease.

Large anisotropy of electrical properties in layer-structured In2Se3 nanowires.

Layer-structured indium selenide (In 2Se 3) nanowires (NWs) have large anisotropy in both shape and bonding. In 2Se 3 NWs show two types of growth directions: [11-20] along the layers and [0001] perpendicular to the layers. We have developed a powerful technique combining high-resolution transmission electron microscopy (HRTEM) investigation with single NW electrical transport measurement, which allows us to correlate directly the electrical properties and structure of the same individual NWs. The NW devices were made directly on a 50 nm thick SiN x membrane TEM window for electrical measurements and HRTEM study. NWs with the [11-20] growth direction exhibit metallic behavior while the NWs grown along the [0001] direction show n-type semiconductive behavior. Excitingly, the conductivity anisotropy reaches 10 (3)-10 (6) at room temperature, which is 1-3 orders magnitude higher than the bulk ratio.

[Protective effect of Yimucao (Herba leonuri) injection against cerebral ischemia: an experimental study in mice and rats].

OBJECTIVE: To investigate the protective effect and mechanism of Yimucao (Herba leonuri) injection against experimental cerebral ischemia. METHODS: Mouse models of cerebral ischemia induced by bilateral carotid artery occlusion or potassium cyanide and rat models of middle cerebral artery occlusion (MCAO)-induced cerebral ischemia/reperfusion injury were established to evaluate the protective effect of Yimucao injection by measuring the changes in cerebral malondialdehyde (MDA) content and the activities of superoxide dismutase (SOD) and lactate dehydrogenase (LDH) after the injections. RESULTS: Yimucao injection significantly lowered the cerebral index of mice with cerebral ischemia, prolonged the survival time of mice poisoned with potassium cyanide, resulting also in significantly decreased MDA content and increased activities of SOD and LDH in the brain tissue of rats after a 10-min cerebral ischemia followed by 30 min of reperfusion. CONCLUSION: Yimucao injection provides protective effect against experimental cerebral ischemia.