Over-expression of human carcinoma-associated antigen in intrahepatic cholangiocellular carcinoma

Objective: To investigate the expression status of human carcinoma antigen (HCA) in human cholangiocellular carcinomas, and to determine the relationship between HCA and clinical features. Methods: Tissues from 60 intrahepatic cholangiocellular carcinoma (ICC) patients, and normal liver tissues from 20 hepatic hemangioma patients selected randomly were assayed for the expression of HCA by immunohistochemistry, and Western blots. Areas of poorly differentiated (n = 20), moderately-well differentiated (n = 30), highly differentiated tumors (n = 10) from different cases were evaluated. Results were recorded as positive (?5% of cells staining and staining intensity 2+ or 3+) or negative (<5% of cells staining and staining intensity <2+) and analyzed using the χ² test. Results: BCE075 and BDD048 antibodies showed similar staining patterns. The positive immunostaining of BCE075 was mainly localized in the cytoplasm and cell secretions. The staining was positive in 15% of poorly differentiated ICC, 72% of moderately-well differentiated, 100% of highly differentiated tumors. But, staining was not detected in adjacent normal tissue. The differences in HCA expression among these tissues were statistically significant. Also, we found expression of HCA to be closely associated with the degree of differentiation of ICC and tumor cell morphology. There was a correlation between expression of HCA and serum CA19-9. Conclusion: The data suggest that HCA is a potential marker for the diagnosis of cholangiocellular carcinoma.     

pH对毕赤酵母表达重组人复合a干扰素的降解影响

使用Pichia pastoris表达重组人复合a干扰素(cIFN)会发生降解、聚合等不均一表达的现象。在5 L发酵罐中考察了不同诱导pH对cIFN表达产生降解的影响, 结果发现在适合酵母生长的pH 3.0~7.0范围内, 当诱导pH为4.0~5.0时, cIFN不均一表达现象最少, 生物活性达到2.5×108 IU/mL。通过测定发酵液中总蛋白酶活和细胞活性寻找了cIFN降解出现的原因：发现低诱导pH下细胞死亡率升高释放更多酶系, 高诱导pH下蛋白酶活性明显增大, 两者都使蛋白酶作用加强, 加剧cIFN的降解; 特别是诱导pH为7.0时, 适宜的pH使蛋白酶酶活陡升, 将cIFN完全降解。     

Neurotransmitter modulation of small-conductance Ca2+-activated K+ channels by regulation of Ca2+ gating

Small-conductance Ca2+-activated K+ (SK) channels are widely expressed in neuronal tissues where they underlie post-spike hyperpolarizations, regulate spike-frequency adaptation, and shape synaptic responses. SK channels constitutively interact with calmodulin (CaM), which serves as Ca2+ sensor, and with protein kinase CK2 and protein phosphatase 2A, which modulate their Ca2+ gating. By recording coupled activities of Ca2+ and SK2 channels, we showed that SK2 channels can be inhibited by neurotransmitters independently of changes in the activity of the priming Ca2+ channels. This inhibition involvesSK2-associated CK2 and results from a 3-fold reduction in the Ca2+ sensitivity of channel gating. CK2phosphorylated SK2-bound CaM but not KCNQ2-bound CaM, thereby selectively regulating SK2 channels. We extended these observations to sensory neurons by showing that noradrenaline inhibits SK current and increases neuronal excitability in aCK2-dependent fashion. Hence, neurotransmitter-initiated signaling cascades can dynamically regulate Ca2+ sensitivity of SK channels and directly influence somatic excitability.     

Effect of rock fragments on the percolation and evaporation of forest soil in Liupan Mountains, China

The water-retaining capacity, percolation and evaporation of stony soil in Liupan Mountains, China, were measured in order to understand the effect of rock fragments on soil hydrological processes. The results indicated that the effective water-retaining capacity of soil is positively related with the volumetric content of rock fragments, but there is no relation between saturated water-retaining capacity and rock fragment content. For the soil layers within 0–40 cm, the steady infiltration rate increases with increasing volumetric content of rock fragments until it reaches the range of 15%–20%, and then it decreases when the rock fragment content further increases. For the soil layers below 40 cm, the steady infiltration rate always increases with increasing rock fragment content. The soil evaporation rate decreases with increasing volumetric content of rock fragments when it varies in the range of 0–20%, while the soil evaporation rate keeps basically stable when the rock fragment content is higher than 20%. The soil evaporation rate shows a rising tendency with increasing size of rock fragments.     

An Improved Li–SeS2 Battery with High Energy Density and Long Cycle Life

Selenium–sulfur solid solutions are a class of potential cathode materials for high energy batteries, since they have higher theoretical capacities than selenium and improved conductivity over sulfur. Here, a high‐performance cathode material by confining 70 wt% of SeS₂ in a highly ordered mesoporous carbon (CMK‐3) framework with a polydopamine (PDA) protection sheath for novel Li–Se/S batteries is reported. With a relatively high SeS₂ mass loading of 2.6–3 mg cm^?2, the CMK‐3/SeS₂@PDA cathode exhibits a high capacity of >1200 mA h g^?1 at 0.2 A g^?1, excellent C‐rate capability of 535 mA h g^?1 at 5 A g^?1, and prolonged life over 500 cycles. Benefitting from the unique advantages of SeS₂ and the rationally designed host framework, this new cathode material demonstrates a feasible strategy to overcome the bottlenecks of current Li–S systems for high energy density rechargeable batteries.     

A practical approach in bioreactor scale‐up and process transfer using a combination of constant P/V and vvm as the criterion

Bioreactor scale‐up is a critical step in the production of therapeutic proteins such as monoclonal antibodies (MAbs). With the scale‐up criterion such as similar power input per volume or O₂ volumetric mass transfer coefficient ( ), adequate oxygen supply and cell growth can be largely achieved. However, CO₂ stripping in the growth phase is often inadequate. This could cascade down to increased base addition and osmolality, as well as residual lactate increase and compromised production and product quality. Here we describe a practical approach in bioreactor scale‐up and process transfer, where bioreactor information may be limited. We evaluated the sparger and (CO₂ volumetric mass transfer coefficient) from a range of bioreactor scales (3–2,000 L) with different spargers. Results demonstrated that for oxygen is not an issue when scaling from small‐scale to large‐scale bioreactors at the same gas flow rate per reactor volume (vvm). Results also showed that sparging CO₂ stripping, , is dominated by the gas throughput. As a result, a combination of a minimum constant vvm air or N₂ flow with a similar specific power was used as the general scale‐up criterion. An equation was developed to determine the minimum vvm required for removing CO₂ produced from cell respiration. We demonstrated the effectiveness of using such scale‐up criterion with five MAb projects exhibiting different cell growth and metabolic characteristics, scaled from 3 to 2,000 L bioreactors across four sites. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1146–1159, 2017     

Flavonoids from Potentilla parvifolia Fisch. and Their Neuroprotective Effects in Human Neuroblastoma SH‐SY5Y Cells in vitro

Potentilla parvifolia Fisch . (Rosaceae) is a traditional medicinal plant in P. R. China. In this study, seven flavonoids, ayanin ( 1 ), tricin ( 2 ), quercetin ( 3 ), tiliroside ( 4 ), miquelianin ( 5 ), isoquercitrin ( 6 ), and astragalin ( 7 ), were separated and purified from ethyl acetate extractive fractions from ethanol extracts of P. parvifolia using a combination of sevaral chromatographic methods. The human neuroblastoma SH‐SY5Y cells were differentiated with all trans‐retinoic acid and treated with okadaic acid to induce tau protein phosphorylation and synaptic atrophy, which could establish an Alzheimer's disease cell model. The neuroprotective effects of these flavonoids in cellular were evaluated in vitro by this cell model. Results from the Western blot and morphology analysis suggested that compounds 3 and 4 had the better neuroprotective effects.