Effective and site-specific phosphoramidation reaction for universally labeling nucleic acids.

Here we report efficient and selective postsynthesis labeling strategies, based on an advanced phosphoramidation reaction, for nucleic acids of either synthetic or enzyme-catalyzed origin. The reactions provided phosphorimidazolide intermediates of DNA or RNA which, whether reacted in one pot (one-step) or purified (two-step), were directly or indirectly phosphoramidated with label molecules. The acquired fluorophore-labeled nucleic acids, prepared from the phosphoramidation reactions, demonstrated labeling efficacy by their F/N ratio values (number of fluorophores per molecule of nucleic acid) of 0.02-1.2 which are comparable or better than conventional postsynthesis fluorescent labeling methods for DNA and RNA. Yet, PCR and UV melting studies of the one-step phosphoramidation-prepared FITC-labeled DNA indicated that the reaction might facilitate nonspecific hybridization in nucleic acids. Intrinsic hybridization specificity of nucleic acids was, however, conserved in the two-step phosphoramidation reaction. The reaction of site-specific labeling nucleic acids at the 5'-end was supported by fluorescence quenching and UV melting studies of fluorophore-labeled DNA. The two-step phosphoramidation-based, effective, and site-specific labeling method has the potential to expedite critical research including visualization, quantification, structural determination, localization, and distribution of nucleic acids in vivo and in vitro.

Azide-alkyne cycloaddition for universal post-synthetic modifications of nucleic acids and effective synthesis of bioactive nucleic acid conjugates.

The regioselective post-synthetic modifications of nucleic acids are essential to studies of these molecules for science and applications. Here we report a facile universal approach by harnessing versatile phosphoramidation reactions to regioselectively incorporate alkynyl/azido groups into post-synthetic nucleic acids primed with phosphate at the 5' termini. With and without the presence of copper, the modified nucleic acids were subjected to azide-alkyne cycloaddition to afford various nucleic acid conjugates including a peptide-oligonucleotide conjugate (POC) with high yield. The POC was inoculated with human A549 cells and demonstrated excellent cell-penetrating ability despite cell deformation caused by a small amount of residual copper chelated to the POC. The combination of phosphoramidation and azide-alkyne cycloaddition reactions thus provides a universal regioselective strategy to post-synthetically modify nucleic acids. This study also explicated the toxicity of residual copper in synthesized bioconjugates destined for biological systems.

Comparison of photodynamic therapy with two different parameters combined with subconjunctival injection of bevacizumab for corneal neovascularization.

BACKGROUND: To the best of our knowledge, no studies have been performed to determine the optimal parameters of photodynamic therapy (PDT) combined with subconjunctival injection of bevacizumab for corneal neovascularization. This study aimed to compare the effect of photodynamic therapy with two different sets of parameters combined with subconjunctival injection of bevacizumab for corneal neovascularization. METHODS: Patients with stable corneal neovascularization (CNV) unresponsive to conventional treatment (topical steroid) were included in this study. Patients were divided into two groups, receiving PDT with two different sets of parameters (group 1 receiving fluence of 50 J/cm2 at 15 min after intravenous injection of verteporfin with, group 2 receiving fluence of 150 J/cm2 at 60 min after intravenous injection of verteporfin with). Subconjunctival injection of bevacizumab was performed immediately after PDT. All patients were followed for 6 months. Best-corrected visual acuity and intraocular pressure were evaluated, and slit-lamp biomicroscopy as well as digital photography were performed. Average diameter and cumulative length of corneal neovascular were measured to evaluate the corneal neovascularization. RESULTS: Seventeen patients (20 eyes) were included in this study. At the last visit, the vision was improved in 12 eyes (60 %), steady in 4 eyes (20 %) and worsen in 4 eyes (20 %). The intraocular pressure (IOP) of all patients remained in normal range. A significant decrease in corneal neovascularization was showed in all the eyes after treatment. At 6 months after the combined treatment, the average diameter and cumulative length of vessels significantly decreased to 0.041 ± 0.023 mm (P < 0.05) and 18.78 ± 17.73 mm (P < 0.05), respectively, compared with the pretreatment data (0.062 ± 0.015 mm, 31.48 ± 18.21 mm). The reduction was more remarkable in group 2 compared to group 1.In group 1, the average diameter was 0.062 ± 0.013mm before and 0.056 ± 0.017mm after, the cumulative length of vessels was 38.66 ± 22.55mm before and 31.21 ± 17.30 after. In group 2, the date were 0.061 ± 0.016mm before and 0.029 ± 0.020mm after, 25.60 ± 8.95 mm before and 8.61 ± 8.26 mm. The reported complications included epithelial defect in four eyes, small white filaments in two eyes and corneal epithelial erosion in two eyes. CONCLUSION: The PDT combined with subconjunctival injection of bevacizumab was effective for the chronic corneal neovascularization. A more promising treatment outcome was observed when PDT was performed at 60 min after intravenous injection of verteporfin with fluence of 150 J/cm2. No serious complications or systemic events were observed throughout the follow-up period.

Comparison of visual acuity outcome and choroidal thickness variation of intravitreal ranibizumab injection for myopic choroidal neovascularization with or without dome-shaped macula.

BACKGROUND: To investigate the visual acuity outcome and choroid thickness (CT) change after intravitreal ranibizumab in highly myopic eyes with or without dome-shaped macula (DSM) in Chinese patients. METHODS: This retrospective, observative study included 80 treatment-naive eyes (80 patients), which received ranibizumab according to the 1+PRN protocol. The best corrective visual acuity (BCVA) and CT change were compared between eyes with or without DSM. RESULTS: There was no significant difference between eyes with or without DSM in BCVA and central macular thickness (CMT). The recurrent rate was not different between the two groups during the first year of treatment. The CT was significantly thinner in eyes with DSM than in eyes without DSM before treatment (median 40.00um versus 71.00um), at 1 month after treatment (median 31.00um versus 65.50um), and in the last follow up (median, 32.00um versus 65.00um) (p = 0.0101). Axial length (AL) was longer in eyes with DSM than those without DSM (median, 29.17 mm versus 28.10 mm) before treatment, and in the last follow up (median, 29.44 mm versus 28.20 mm) (p = 0.0055). The CT was significantly correlated with AL (p < 0.0001). CONCLUSIONS: No difference was found in visual outcome between eyes with or without DSM. The visual acuity significantly improved at 1 month after ranibizumab injection and it was recovery sooner in extrafoveal choroidal neovascularization (CNV) group than in subfoveal CNV group. The CT was thinner in eyes with DSM, which was significantly correlated with AL.

[Pedigree investigation and genetic analysis of a case with p blood group].

OBJECTIVE: To explore the molecule basis of a p blood group in a patient with gastric carcinoma. METHODS: The p phenotype was determined with serological method. Inheritance of the p phenotype was investigated by pedigree analysis. Sequence of α-1,4- galactosyltransferase (A4GALT) gene was determined by Sanger method. RESULTS: The proband and his younger brother were both determined to have a p phenotype. Two homozygous variations, c.343A>T (AAA>TAA) and c.903C>G (CCC>CCG), have been detected in exon 3 of the A4GALT gene. Among these, c.343 A>T (AAA>TAA) was a novel mutation, which has resulted in a termination codon, with which no normal product of the gene can be produced. c.903C>G was determined to be a polymorphism. CONCLUSION: A novel c.343A>T mutation in the A4GALT gene probably underlies the p phenotype, to which a Genbank access number KC202808 has been assigned.

Advanced aqueous-phase phosphoramidation reactions for effectively synthesizing peptide-oligonucleotide conjugates trafficked into a human cell line.

Peptide-oligonucleotide conjugates (POCs) have held promise as effective therapeutic agents in treating microbial infections and human genetic diseases including cancers. In clinical applications, POCs are especially useful to circumvent cellular delivery and specificity problems of oligonucleotides. We previously reported that nucleic acid phosphoramidation reactions performed in aqueous solutions have the potential for facile POC synthesis. Here, we carried out further studies to significantly improve aqueous-phase two-step phosphoramidation reaction yield. Optimized reactions were employed to effectively synthesize POCs for delivery into human A549 cells. We achieved optimization of aqueous-phase two-step phosphoramidation reaction and improved reaction yield by (1) determining appropriate co-solutes and co-solute concentrations to acquire higher reaction yields, (2) exploring a different nucleophilicity of imidazole and its derivatives to stabilize essential nucleic acid phosphorimidazolide intermediates prior to POC formation, and (3) enhancing POC synthesis by increasing reactant nucleophilicity. The advanced two-step phosphoramidation reaction was exploited to effectively conjugate a well-studied cell penetrating peptide, the Tat(48-57) peptide, with oligonucleotides, bridged by either no linkers or a disulfide-containing linker, to have the corresponding POC yields of 47-75%. Phosphoramidation-synthesized POCs showed no cytotoxicity to human A549 cells at studied POC concentrations after 24 h inoculation and were successfully trafficked into the human A549 cell line as demonstrated by flow cytometry, fluorescent microscopy, and confocal laser scanning microscopy study. The current report provides insight into aqueous-phase phosphoramidation reactions, the knowledge of which was used to develop effective strategies for synthesizing POCs with crucial applications including therapeutic agents for medicine.

Characteristics of macular microvasculature before and after idiopathic macular hole surgery.

AIM: To evaluate the macular microvasculature before and after surgery for idiopathic macular hole (MH) and the association of preoperative vascular parameters with postoperative recovery of visual acuity and configuration. METHODS: Twenty eyes from 20 patients with idiopathic MH were enrolled. Optical coherence tomography angiography (OCTA) images were obtained before, 2wk, 1, and 3mo after vitrectomy with internal limiting membrane peeling. Preoperative foveal avascular zone (FAZ) area and perimeter and regional vessel density (VD) in both layers were compared according to the 3-month best-corrected visual acuity (BCVA). RESULTS: The BCVA improved from 0.98±0.59 (logMAR, Snellen 20/200) preoperatively to 0.30±0.25 (Snellen 20/40) at 3mo postoperatively. The preoperative deep VD was smaller and the FAZ perimeter was larger in the 3-month BCVA<20/32 group (all P<0.05). A significant reduction was observed in FAZ parameters and all VDs 2wk postoperatively. Except for deep perifoveal VD, all VDs recovered only to their preoperative values. The postoperative FAZ parameters were lower during follow-up. Decreases in preoperative deep VDs were correlated with worse postoperative BCVA (Pearson's r=-0.667 and -0.619, respectively). A larger FAZ perimeter (Spearman's r=-0.524) and a lower deep perifoveal VD preoperatively (Pearson's r=0.486) were associated with lower healing stage. CONCLUSION: The status of the deep vasculature may be an indicator of visual acuity in patients with a closed MH. Except for the deep perifoveal region, VD recovers only to preoperative levels.

[The serological and genetic identification of a CisAB blood sample].

OBJECTIVE: To verify the DNA sequence of a sample serologically identified as CisAB. METHODS: Forward and reverse group methods were used to determine the blood serological type of that the sample, and PCR-sequence specific primer (PCR-SSP) method was used for genotyping the sample. RESULTS: Serologically, the forward group test showed that the sample was AB, while the reverse group test showed that the sample had the anti-B and anti-H + + +. The auto antibodies were negative. PCR-SSP assay showed the sample was CisAB01. ABO genetic locus sequencing showed c.261delG in exon 6, c.297 was homozygous AA. Mutations c.467C to T and c.803G to C were found in exon 7. A novel heterozygous mutation, c.724G to T, was detected. CONCLUSION: The serological phenotype of the specimen was CisAB. The genotype was ABO *CisAB01 and ABO *O01. A novel mutation c.724G to T in exon 7 was identified (GenBank accession no. JF304777).

HS-GC-IMS-Based metabonomics study of Baihe Jizihuang Tang in a rat model of chronic unpredictable mild stress.

The aim of this study was to investigate the differences in volatile organic compounds (VOCs) obtained from the feces of a Baihe Jizihuang Tang (BHT)-treated rat depression model. Rats were subjected to chronic unpredictable mild stress (CUMS), and the differences in VOCs were analyzed by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS), NIST software, principal component analysis, and orthogonal partial least squares discriminant analysis. Eleven biomarkers were identified on the basis of VOC migration time, and their relative peak intensities were analyzed. A metabonomic model was established using multivariate statistical analysis. The study demonstrated the metabonomics of CUMS rats and the intervention effect of BHT and also highlighted the potential therapeutic effects of the traditional Chinese medicine (TCM) Jingfang for the clinical treatment of complex diseases, which was in line with the holistic and systemic approaches of TCM. This study augments the use of metabonomics based on HS-GC-IMS in research studies. Using this method, there is no need to pre-process samples by extraction or derivatization, and the VOC component of the sample can be detected directly and rapidly. In conclusion, this study establishes a simple, convenient, and fast technique, which can help identify clinical biomarkers for rapid medical diagnosis.

Study of qingre liyan decoction in treating and preventing acute radioactive oral mucositis.

OBJECTIVE: To study the effect of Qingre Liyan Decoction (QRLYD) in the prevention and treatment of acute radiative oral mucositis (AROM), and to explore the mechanism of QRLYD by detecting epidermal growth factor (EGF) and T lymphocytes (CD3, CD4, and CD8). METHODS: Sixty patients conforming with the standard were randomly assigned to two groups, 30 patients in each group. Patients in the trial group were treated with QRLYD, and those in the control group were treated with Dobell's solution, both groups receiving conventional radiation treatment. The treatment course for both groups was 6 weeks on average. Blood routine test, CD3, CD4, and CD8 in the peripheral blood and EGF in the saliva were detected one day before and on the 14th and 28th day of radio-therapy. RESULTS: Patients in the trial group were in good condition with normal spirits and intake of food and drinks. The incidence of AROM is lower and the effect in preventing AROM is higher in the trial group than those in the control group (P<0.05). The EGF in saliva, and CD4 and CD8 in the blood of patients in the trial group were higher than those in the control group (P<0.05). CONCLUSION: QRLYD can cure and prevent AROM. The mechanism may be related with its effects in enhancing body immunity and promoting salivary EGF.

[Identification of a Rare Ael05/B101 Subtype and Selection of Blood Transfusion Strategy].

OBJECTIVE: To explore the mechanism of ABO discrepancy in a patient by ABO genotyping and the reasonable blood transfusion strategy. METHODS: Routine serological test was carried out to analyze ABO blood group. The presence of the blood group determinants on the red blood cells were determined by adsorption-elution test. Exons 1-7 and adjacent introns of the ABO gene were amplified by PCR and sequenced. RESULTS: The patient showed ABO forward and reverse typing discrepancy. ABO forward typing defined as B, however, the reverse typing indicated that the patient was AB subtype. Absorption-elution test confirmed weak A antigens on the patient's red blood cells. The ABO gene sequencing showed a T>C exchange at position in exon 7 which resulted in a isoleucine to threonine substitution at codon 256. The ABO blood group genotype was ABO*Ael05/B101. CONCLUSION: The 767 T>C substitution in the gene of α-1,3-N-acetyl galactose is the molecular mechanism leading to the decrease expression of A antigen of the Ael05 subtype.

Erythrocyte concentrates recovered from under-collected whole blood: experimental and clinical results.

BACKGROUND: Although periodic blood shortages are widespread in major Chinese cities, approximately 1 x 10(5) U of whole blood are discarded yearly because of under-collection. To reduce the wastage of acid citrate dextrose solution B (ACD-B) anticoagulated under-collected whole blood (UC-WB), this study was performed to elucidate the effect of extracellular pH and holding time on erythrocyte quality. Mannitol-adenine-phosphate (MAP) erythrocyte concentrates (UC-RBCs) were prepared with UC-WB to assess the safety and efficacy of this component. METHODS: The effect of the different extracellular pH levels and storage times on erythrocytes was assessed by fluorescent probes, SDS-PAGE electrophoresis, electron microscopy and spectroscopy. In vitro properties of 34 UC-RBCs that were prepared with UC-WB at different times after collection were analyzed and compared to normal RBCs during 35 days of storage. The results of transfusion with UC-RBCs and the incidence of adverse reactions in 49 patients were determined. RESULTS: 1) Low extracellular pH levels and long storage time induced increases in RBC fluorescence polarization and mean microviscosity, changes in membrane fluidity, band 1, 2 and 3 protein expression, and erythrocyte morphology. 2) During storage for 35 days, difference in between-subjects effects of K+, hemolysis and supernatant erythrocyte membrane protein (EMP) were statistically significant (P = 0.041, 0.007 and 0.002, respectively), while the differences between these parameters in the 4 h group and comparable controls were less significant. 3) Clinical data from 49 patients confirmed that transfusions with UC-RBCs were satisfactory with no adverse reactions. CONCLUSION: These results suggest that it is feasible to prepare RBCs with ACD-B anticoagulated UC-WB at a minimum of 66% volume of the labeled collection. It was effective and safe to transfuse the UC-RBCs prepared within 4 h after collection and stored within 7 days. The use of UC-WB would be a welcome addition to limited blood resources in China. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR-TRC-13003967.

A novel sodium N-fatty acyl amino acid surfactant using silkworm pupae as stock material.

A novel sodium N-fatty acyl amino acid (SFAAA) surfactant was synthesized using pupa oil and pupa protein hydrolysates (PPH) from a waste product of the silk industry. The aliphatic acids from pupa oil were modified into N-fatty acyl chlorides by thionyl chloride (SOCl2). SFAAA was synthesized using acyl chlorides and PPH. GC-MS analysis showed fatty acids from pupa oil consist mainly of unsaturated linolenic and linoleic acids and saturated palmitic and stearic acids. SFAAA had a low critical micelle concentration, great efficiency in lowering surface tension and strong adsorption at an air/water interface. SFAAA had a high emulsifying power, as well as a high foaming power. The emulsifying power of PPH and SFAAA in an oil/water emulsion was better with ethyl acetate as the oil phase compared to n-hexane. The environment-friendly surfactant made entirely from silkworm pupae could promote sustainable development of the silk industry.

[A A311 blood group gene subtype caused by a-1-3-N-acetylgalactosaminyltransferase gene exon 7 mutations].

This study was purposed to analyses the serological and molecular basis of one sample of A blood group which has anti-A. The tube method was used to detect the blood group phenotype, the genotype was amplified by PCR-SSP. The sequence of a-1-3-N-acetylgalactosaminyltransferase gene of blood group was determined by Sanger method. The results showed that serological results of blood group were discrepant. It was determined as A subtype firstly. The result of PCR-SSP showed the existence of O and A blood group gene. The sequencing result of the 6th exon of ABO gene showed the existence of c.261delG, which refers to the O gene. The specific amplification sequencing analysis was carried out on the 7th exon of the O and A blood group gene. Two mutations in the 7th exon of the A gene haplotype, c.467 C > T and c.626 G > A, four mutations in the 7th exon of the O gene haplotype, c.646T > A, 681G > A, 771C > T, 829G > A had been detected. It is concluded that a novel allelic mutation c.626 G > A in the 7th exon of A gene is explored. The Genbank access number of this novel mutation is KC690281. c.467 C > T is SNP. The combination of two allele mutation of A gene is named as a new allelic subtype A311.

[Detection of fetal RASSF1A gene in maternal plasma for noninvasive prenatal diagnosis].

The aim of this study was to investigate the feasibility of using RASSF1A gene as a universal fetal marker in maternal plasma. Two methods of circulating cell-free fetal DNA (cffDNA) extracted from maternal plasma were compared. The better one was chosen for extraction of cffDNA in the 20 pregnant samples. The SRY gene and the RASSF1A gene treated with methylation-sensitive restriction enzyme were amplificated by RT-PCR and the PCR system was optimized. The results showed that the SRY gene was found in 11 out of the 20 pregnant samples, which was consistent with the postnatal sex. Using the optimized PCR system, the specifically amplified fetal-associated methylated RASSF1A gene was found after treatment with BstUI in 18 of the 20 pregnant samples, while the 2 samples failed in detection. It is concluded that the methylated fetal-specific RASSF1A gene can be used as a universal fetal marker for the presence of cffDNA in maternal plasma without fetal gender restrictions. So, it can be used for noninvasive prenatal diagnosis.

[Effect of vitamin C antioxidative protection on human red blood cells].

In order to investigate the effect of antioxidants on human blood, vitamin C was selected and added into plastic blood storage bags with CPD, and stored at 25 degrees C. During 6 days of storage, some indexes as ATP, SOD, MDA, K(+) concentration and superoxide radicals were detected and were compared with control group, The results showed that ATP and SOD activity in whole blood with vitamin C during 6 days of storage was higher then that in control group (P < 0.05, P < 0.01), the MDA and plasma K(+) concentrations in stored whole blood with vitamin C during 6 days of storage were lower than that in control group (P < 0.05, P < 0.01), the superoxide radical concentrations in stored whole blood with vitamin C decreased lower than that in control group (30%). The conclusion was made that vitamin C increases activities of ATP and SOD, decreases concentrations of MDA, plasma K(+) and superoxide radicals during blood preservation.