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Objective To investigate the clinical features and prognosis of HIV-negative plasmablastic lymphoma (PBL) patients. Methods We collected HIV-negative PBL cases reported in our hospital and other literatures from online databases from January 1, 1997 to March 30, 2020. The data of clinical features, molecular pathology, treatment and prognosis were summarized and analyzed. Results We included 60 PBL patients, average age was 53.06±14.36 years, and most of them had relatively high Ann Arbor stage and Ki-67 expression. The average OS was 13.48±13.21 m. Kaplan-Meier curve revealed Ann Arbor stage, IPI index (3-5), B symptoms and CR in initial treatment were significantly related with patients' survival. Cox regression analysis indicated that the Ann Arbor stage and IPI index were the independent prognostic factors for patients' survival. Conclusion HIV-negative PBL mostly occurs in the middle-age and elderly patients, with advanced diagnosis stage and rapid tumor proliferation. Combination chemotherapy is the main treatment, while the therapeutic response and OS might be heterogeneous, the prognosis of most patients would be poor. The stage and IPI index are significantly related to the prognosis.

Vinyl carbazole (VK) grafted polyethylene (VK-g-LDPE) was prepared using melting method in the rheometer in this paper. The electrical properties of ethylene carbazole grafted polyethylene with different content of vinyl carbazole were studied. The results show that with the increase of VK content, the inhibition of internal space charge the breakdown field strength and the volume resistivity of VK-g-LDPE increase first and then decrease, compared with those of pure LDPE. When the VK content is 12.6%, the space charge inhibition of VK-g-LDPE material is the best, which decreases by 94.8%. When the VK content is 13.5%, the breakdown field strength is 50.24 kV/mm, which increases by 62.9%. When the content of VK is 10.1 %, the volume resistivity is 4.53 X 1015 Ω * m, which is 2.7 times of original value. [ABSTRACT FROM AUTHOR]

L-homoserine and its derivatives (O-succinyl-L-homoserine and O-acetyl-L-homoserine) are precursors for the biosynthesis of L-methionine, and various C4 compounds (isobutanol, γ-butyrolactone, 1, 4-butanediol, 2, 4-dihydroxybutyric acid) and L-phosphinothricin. Therefore, the fermentative production of L-homoserine and its derivatives became the research hotspot in recent years. However, the low fermentation yield and conversion rate, and the unclear regulation mechanism for the biosynthesis of L-homoserine and its derivatives, hamper the development of an efficient production process for L-homoserine and its derivatives. This review summarized the advances in the biosynthesis of L-homoserine and its derivatives by metabolic engineering of Escherichia coli from the aspects of substrate uptake, redirection of carbon flow at the key nodes, recycle of NADPH and export of target products. This review may facilitate subsequent metabolic engineering and biotechnological production of L-homoserine and its derivatives.

Objective To observe the effects of interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α) on glial cell line-derived neurotrophic factor (GDNF) and its receptors in rat intestinal smooth muscle cells (ISMCs). Methods ISMCs were isolated by modified enzyme digestion in SD rats, and the positive rates of smooth muscle α-actin (α-SMA) and desmin were observed by immunocytochemical staining. ISMCs were treated with IL-1β and TNF-α for 48 hours alone or in combination. The relative mRNA expression of GDNF, receptor tyrosine kinase (Ret) and GDNF family receptor alpha-1 (GFRα1) were measured by real-time quantitative PCR. Results High-purity ISMCs were obtained by modified enzyme digestion, and over 95% of the cells expressed α-SMA and desmin. Compared with the control group, TNF-α could promote the expression of GDNF and inhibit GFRα1, but had no effects on Ret. In contrast, IL-1β could inhibit Ret but had no effects on GDNF and GFRα1. Notably, when IL-1β and TNF-α were combined, the expression of GDNF was up-regulated, while RET and GFRα1 were down-regulated. Conclusion IL-1β and TNF-α can up-regulate the expression of GDNF and down-regulate its receptors in rat ISMCs.

A high performance capillary electrophoresis (HPCE) method was developed for the simultaneous determination of penicillin intermediate and penicillins in milk, including 6-amino-penicillanic acid (6-APA), penicillin G (PEN), ampicillin (AMP) and amoxicillin (AMO). The main parameters including the ion concentration and pH value of running buffer, separation voltage and column temperature were optimized systematically by orthogonal test. The four penicillins (PENs) were baseline separated within 4.5 min with the running buffer of 40 mmol/L potassium dihydrogen phosphate-20 mmol/L borax solution (pH 7.8), separation voltage of 28 kV and column temperature of 30 degrees C. The calibration curves showed good linearity in the range of 1.56 - 100 mg/L, and the correlation coefficients (r2) were between 0.9979 and 0.9998. The average recoveries at three spiked levels were in the range of 84.91% - 96.72% with acceptable relative standard deviations (RSDs) of 1.11% - 9.11%. The method is simple, fast, accurate and suitable for the determination of penicillins in real samples.