A simple method for determining compound affinity and chemical yield from DNA-encoded library selections.

DNA-encoded libraries (DELs) can contain billions of unique chemical species; selecting against such large inputs, it is typical to find more candidate binders than is reasonable to pursue for follow-up synthesis and testing. Given this wealth of choices, common practice is to limit synthesis to only those compounds estimated to have the greatest chance of being high-affinity binders; of the many potential factors contributing to this estimation, the strength of the selection signal of a candidate binder is always important. We define here methods and equations which relate the theoretical selection signal of a compound to its affinity and chemical yield. Tests using known binders of BRD4 and ROCK2 support the theory backing these equations and suggest they should be of use for prospectively determining affinity and chemical yield from primary DEL selection data.

[A multicenter survey of antibiotic use in very and extremely low birth weight infants in Hunan Province].

OBJECTIVE: To investigate the current status of antibiotic use for very and extremely low birth weight (VLBW/ELBW) infants in neonatal intensive care units (NICUs) of Hunan Province. METHODS: The use of antibiotics was investigated in multiple level 3 NICUs of Hunan Province for VLBW and ELBW infants born between January, 2017 and December, 2017. RESULTS: The clinical data of 1 442 VLBW/ELBW infants were collected from 24 NICUs in 2017. The median antibiotic use duration was 17 days (range: 0-86 days), accounting for 53.0% of the total length of hospital stay. The highest duration of antibiotic use was up to 91.4% of the total length of hospital stay, with the lowest at 14.6%. In 16 out of 24 NICUs, the antibiotic use duration was accounted for more than 50.0% of the hospitalization days. There were 113 cases with positive bacterial culture grown in blood or cerebrospinal fluid, making the positive rate of overall bacterial culture as 7.84%. The positive rate of bacterial culture in different NICUs was significantly different from 0% to 14.9%. The common isolated bacterial pathogens Klebsiella pneumoniae was 29 cases (25.7%); Escherichia coli 12 cases (10.6%); Staphylococcus aureus 3 cases (2.7%). The most commonly used antibiotics were third-generation of cephalosporins, accounting for 41.00% of the total antibiotics, followed by penicillins, accounting for 32.10%, and followed by carbapenems, accounting for 13.15%. The proportion of antibiotic use time was negatively correlated with birth weight Z-score and the change in weight Z-score between birth and hospital discharge (rs=-0.095, -0.151 respectively, P<0.01), positively correlated with death/withdrawal of care (rs=0.196, P<0.01). CONCLUSIONS: Antibiotics used for VLBW/ELBW infants in NICUs of Hunan Province are obviously prolonged in many NICUs. The proportion of routine use of third-generation of cephalosporins and carbapenems antibiotics is high among the NICUs.

[Impact factors analysis of standardized perioperative antibiotic application on nosocomial infection and drug-resistance bacteria].

OBJECTIVE: To investigate the impact factors and clinical significance of standardized perioperative antibiotic application on nosocomial infection and drug-resistant bacteria strains in eye hospital. METHODS: It was a retrospective series case study. The inpatients underwent ophthalmologic operation of one year before standardized application (from Sep. 2009 to Aug. 2010) and one year after standardized application (from Sep. 2010 to Aug. 2011) in Tianjin Eye Hospital were selected and the incidence rate of nosocomial infection and types of drug-resistant strains in these two years were analyzed. RESULTS: From Sep. 2009 to Aug. 2010, the prophylactic antibiotics application rate for type I incisional surgeries was 80.29% (12937/16 111), the nosocomial infection rate was 0.011% (2/17 563). From Sep. 2010 to Aug. 2011, the same values were 44.50% (7968/17 905) and 0.005% (1/19 441). There was a significant decrease of prophylactic antibiotics application comparing these two years (χ(2) = 4587.78, P < 0.05). However, there was no significant difference in nosocomial infection rate (χ(2) = 0.44, P > 0.05). Average antibiotics application rate for inpatient (type I-IV incisional surgeries) was 76.69% (13 469/17 563) from Sep. 2009 to Aug. 2010, and 49.40% (9604/19 441) from Sep. 2010 to Aug. 2011. There was a significant decrease over these two years (χ(2) = 2927.19, P < 0.05). The results of isolation and cultivation of bacteria in these two years showed that staphylococcus epidermidis predominated in gram-positive bacteria, pseudomonas aeruginosa predominated in gram-negative bacteria. Drug resistance rate of staphylococcus was 42.86% (33/77) from Sep. 2009 to Aug. 2010 and 39.19% (39/74) from Sep. 2010 to Aug. 2011. Drug resistance rate of pseudomonas aeruginosa was 2/11 from Sep. 2009 to Aug. 2010 and 2/13 from Sep. 2010 to Aug. 2011. There were no significant differences in drug resistance rate of staphylococcus and pseudomonas aeruginosa between these two years (χ(2) = 0.09, P > 0.05, χ(2) = 0.03, P > 0.05). CONCLUSIONS: By standardizing the perioperative antibiotics application in eye hospital, the rate of systemic administration of antibiotics declined gradually. The Choices and the administrative mode of antibiotics were more rational than before. In the meanwhile, the rate of nosocomial infection and drug-resistance did not increase. Therefore, avoiding the drug abuse ensured the medical safety, which was worthy of further study.

[Characters of multifocal electroretinogram in different grades of diabetic macular edema].

OBJECTIVE: To investigate the characters of multifocal electroretinogram (mfERG) in different grades of diabetic macular edema defined by optical coherence tomography (OCT). METHODS: MfERG and OCT were performed in 57 eyes of diabetic macular edema (DME) patients and 35 eyes of the control group. According to the macular thickness measured by OCT, eyes with DME were divided into three groups: mild, moderate and severe DMEs. RESULTS: In mild DME, the response densities of N(1) were attenuated in ring 4[(14.67 ± 4.91) nV×deg(-2)] to ring 5 [(11.65 ± 3.89) nV×deg(-2)] respectively (t = 2.179, 2.529; P < 0.05). The latencies of P(1) was prolonged significantly in ring 3 [(40.61 ± 4.10) ms] (t = -2.133, P < 0.05). In moderate DME, the response densities of P(1) and N(1) were attenuated in ring 1 [(149.50 ± 29.01) nV×deg(-2)], ring 2 [(59.33 ± 25.96) nV×deg(-2)], ring 3 [(41.83 ± 9.78) nV×deg(-2)], and ring 5 [(22.00 ± 5.52) nV×deg(-2)] respectively (t = 3.610, 2.168, 2.627, 3.445; P < 0.05). The latencies of P(1) and N(1) were prolonged significantly in ring 3 [(42.86 ± 4.72) ms], ring 4 [(44.33 ± 5.56) ms], ring 5 [(46.31 ± 4.72) ms] (t = -3.150, -3.210, -3.968; P < 0.05) and ring 3 [(23.05 ± 3.06) ms], ring 4 [(22.41 ± 3.36) ms] (t = -2.845, -2.098; P < 0.05) respectively. In severe DME. The response densities of P(1) and N(1) were attenuated in ring 1 [(110.00 ± 20.68) nV×deg(-2)], ring 2 [(62.40 ± 27.90) nV×deg(-2)], ring 3[(39.20 ± 19.65) nV×deg(-2)], ring 5 [(21.60 ± 11.12) nV×deg(-2)] (t = 7.135, 1.782, 2.214, 2.609; P < 0.05) and ring 1 [(41.63 ± 39.17) nV×deg(-2)], ring 3 [(16.63 ± 5.81) nV×deg(-2)], ring 4 [(11.20 ± 7.42) nV×deg(-2)], ring 5 [(9.05 ± 4.63) nV×deg(-2)] (t = 2.714, 2.282, 2.736, 2.858; P < 0.05) respectively. The latencies of P(1) and N(1) were prolonged significantly in ring 1 [(35.12 ± 8.44) ms], ring 3 [(40.44 ± 2.10) ms], ring 4 [(42.80 ± 3.74) ms] (t = 3.426, -2.710, -3.120; P < 0.05) and ring 4 [(23.36 ± 4.05) ms] (t = -2.572; P < 0.05) respectively. CONCLUSION: As the progress of DME, the thickness of macular fovea had significant correlation with responses of multifocal electroretinogram in patients with moderate or severe DME. MfERG combined with OCT can evaluate the changes of morphology and local retinal function in macula area objectively and quantitatively.

Synthesis of Isomalto-Oligosaccharides by Pichia pastoris Displaying the Aspergillus niger α-Glucosidase.

We explored the ability of an Aspergillus niger α-glucosidase displayed on P. pastoris to act as a whole-cell biocatalyst (Pp-ANGL-GCW61) system to synthesize isomalto-oligosaccharides (IMOs). IMOs are a mixture that includes isomaltose (IG2), panose (P), and isomaltotriose (IG3). In this study, the IMOs were synthesized by a hydrolysis-transglycosylation reaction in an aqueous system of maltose. In a 2 mL reaction system, the IMOs were synthesized with a conversion rate of approximately 49% in 2 h when 30% maltose was utilized under optimal conditions by Pp-ANGL-GCW61. Additionally, the 0.5-L reaction system was conducted in a 2-L stirred reactor with a conversion rate of approximately 44% in 2 h. Moreover, the conversion rate was relatively stable after the whole-cell catalyst was reused three times. In conclusion, Pp-ANGL-GCW61 has a high reaction efficiency and operational stability, which makes it a powerful biocatalyst available for industrial scale synthesis.

Veronicastrum axillare Alleviates Ethanol-Induced Injury on Gastric Epithelial Cells via Downregulation of the NF-kB Signaling Pathway.

We used human gastric epithelial cells (GES-1) line in an ethanol-induced cell damage model to study the protective effect of Veronicastrum axillare and its modulation to NF-κB signal pathway. The goal was to probe the molecular mechanism of V. axillare decoction in the prevention of gastric ulcer and therefore provide guidance in the clinical application of V. axillare on treating injuries from chronic nephritis, pleural effusion, gastric ulcer, and other ailments. The effects of V. axillare-loaded serums on cell viability were detected by MTT assays. Enzyme-linked immunosorbent assay (ELISA) and Real-Time PCR methods were used to analyze the protein and mRNA expression of TNF-α, NF-κB, IκBα, and IKKß. The results showed that V. axillare-loaded serum partially reversed the damaging effects of ethanol and NF-κB activator (phorbol-12-myristate-13-acetate: PMA) and increased cell viability. The protein and mRNA expressions of TNF-α, NF-κB, IκBα, and IKKß were significantly upregulated by ethanol and PMA while they were downregulated by V. axillare-loaded serum. In summary, V. axillare-loaded serum has significantly protective effect on GES-1 against ethanol-induced injury. The protective effect was likely linked to downregulation of TNF-α based NF-κB signal pathway.

Synthesis of octyl-ß-D-glucopyranoside catalyzed by Thai rosewood ß-glucosidase-displaying Pichia pastoris in an aqueous/organic two-phase system.

We explored the ability of a Thai rosewood ß-glucosidase-displaying P. pastoris whole-cell biocatalyst (Pp-DCBGL) system to synthesize alkyl ß-D-glucosides. The primary investigation centered on the synthesis of octyl-ß-D-glucopyranoside (octyl-glu, OG). OG could be synthesized through reverse hydrolysis reaction with very low efficiency. Then, OG was synthesized between BG and octanol by a transglycosylation reaction. In a 2-ml reaction system, OG was synthesized with a conversion rate of 51.1% in 3h when 5 mg/ml BG was utilized as the glucosyl donor under optimized conditions. And, even after being reused four times, the Pp-DCBGL was relatively stable. Additionally, a 500-ml-scale reaction system was conducted in a 2-L stirred reactor with a conversion rate of 47.5% in 1.5 h. Moreover, the conversion rate did not decrease after the whole-cell catalyst was reused two times. In conclusion, Pp-DCBGL has high reaction efficiency and operational stability, which is a powerful biocatalyst available for industrial synthesis.

Scaling-up the synthesis of myristate glucose ester catalyzed by a CALB-displaying Pichia pastoris whole-cell biocatalyst.

The novel whole-cell biocatalyst Candida antarctica lipase B displaying-Pichia pastoris (Pp-CALB) is characterized by its low preparation cost and could be an alternative to the commercial immobilized Candida antarctica lipase B (CALB). This study addresses the feasibility of using Pp-CALB in large scale glucose fatty acid esters production. 1,2-O-Isopropylidene-α-D-glucofuranose (IpGlc) was used as the acyl acceptor to overcome the low solubility of glucose in an organic solvent and to avoid the addition of toxic co-solvents. IpGlc significantly improved the Pp-CALB catalyzing esterification efficiency when using long chain fatty acids as the acyl donor. Under the preferred operating conditions (50 °C, 40 g/L molecular sieve dosage and 200 rpm mixing intensity), 60.5% of IpGlc converted to 6-O-myristate-1, 2-O-isopropylidene-α-D-glucofuranose (C14-IpGlc) after a 96-h reaction in a 2-L stirred reactor. In a 5-L pilot scale test, Pp-CALB also showed a similar substrate conversion rate of 55.4% and excellent operational stability. After C14-IpGlc was collected, 70% trifluoroacetic acid was adopted to hydrolyze C14-IpGlc to myristate glucose ester (C14-Glc) with a high yield of 95.3%. In conclusion, Pp-CALB is a powerful biocatalyst available for industrial synthesis, and this study describes an applicable and economical process for the large scale production of myristate glucose ester.

[An analysis of adhered cells on the surface of F-heparin surface modified intraocular lenses implanted into rhesus monkeys' eyes].

OBJECTIVE: To study the biocompatibility of F-heparin surface modified intraocular lenses (IOLs) by observing cellular reaction on the surface of IOLs implanted into the rhesus monkeys' eyes. METHODS: Ten monkeys (20 eyes) were classified into two groups. PMMA IOLs and F-heparin modified IOLs were respectively implanted into 10 monkeys' eyes. The IOLs were examined with computer image analysis, light microscope (LM) and scanning electron microscope (SEM) at postoperative 180 and 360 days. RESULTS: A few of adhered cells were on the surface of the central part of the IOL and more on the border of the IOL optics. The giant cells deposited on the surface occupied the largest area and the number of the macrophages was the greatest. The cells deposited on the surface of the IOLs in the F-heparin modified group were less than that in the non-modified group. In the modified group, there was fine granular proteinaceous membrane on the surface of the IOLs, but in the non-modified group there was fibrinous reticular proteinaceous membrane. CONCLUSION: The biocompatibility of the F-heparin surface modified IOLs is better than that of non-modified PMMA IOLs.

Optical coherence tomographic features in a case of bilateral macular coloboma with strabismus.

PURPOSE: To report the optical coherence tomography (OCT) findings in a patient with bilateral macular coloboma with strabismus. METHODS: A 21-year-old male presented with macular coloboma in both eyes.Fundus photography, fundus fluorescence angiography (FFA) and OCT were performed. RESULTS: Color fundus photography showed a sharply-demarcated, round macular defect, approximately 4×4 disc diameters with bare sclera at the base and pigment clumping in both eyes. FFA showed hypofluorescence at the macula corresponding to the size of the lesion bilaterally. OCT revealed a crater-like depression at the macula, demonstrating atrophic neurosensory retina, and an absence of retinal pigment epithelium (RPE) and choroid in the lesion. CONCLUSION: OCT can be a beneficial tool to confirm the diagnosis of macular coloboma.

Effect of CO(2) laser sclerectomy with iridectomy on ocular hypertension in rabbits.

AIM: To evaluate the efficiency and safety of an optimized CO(2) Laser glaucoma surgery system for laser sclerectomy with iridectomy. METHODS: Rabbit trials were performed to evaluate the efficiency and safety. RESULTS: IOP was significantly decreased in laser group compared with trabeculectomy group(P<0.05) from 7(th) postoperative day to 60(th) day. Compared with trabeculectomy group, histopathology studies confirmed fewer complications and better effects were found in laser group. CONCLUSION: CO(2) laser sclerectomy with iridectomy is effective and safe in terms of IOP lowering.

F-heparin modified intraocular lenses in Rhesus monkeys.

AIM: In order to improve the biocompatibility of intraocular lenses (IOL), the polymethylmethacrylate (PMMA) IOL was modified with F-heparin. METHODS: The PMMA IOL was modified with F ions and heparin by the technique of ion beam combined with low temperature and low pressure plasma. The monkeys (20 eyes) with cataract partly were randomly classified into 2 groups and implanted with PMMA IOL and modified IOL respectively for 180 days. All of the eyes were examined by slit-lamp microscope at postoperative 15, 30, 60, 90, 180 days. The extracted IOL was analyzed with computer image analysis, light microscope (LM) and scanning electron microscope (SEM) at postoperative 180 days. RESULTS: The early inflammatory reactions postoperatively include anterior chamber exudation and aqueous cell count. The modified IOL group showed less than the non-modified IOL group. The late foreign body cell reaction that adhered to the surface of non-modified IOL was more predominant. The morphologic and pathological changes of posterior capsule opacification (PCO) in monkeys' eyes included fibrosis-type, pearl-type and soemmerring's ring. There was a significant difference between the two groups. CONCLUSION: F-heparin modified IOL has good uveal and capsular biocompatibility.