Latest Issue
Issue 9 ， 2013
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Structures and biogenetic analysis of lipofuscin bis-retinoids
Abstract：Age-related macular degeneration (AMD) is still an incurable blinding eye disease because of complex pathogenic mechanisms and unusual diseased regions. With the use of chemical biology tools, great progress has been achieved in improving the understanding of AMD pathogenesis. The severity of AMD is, at least in part, linked to the non-degradable lipofuscin bis-retinoids in retinal pigment epithelial (RPE). This material is thought to result from the lifelong accumulation of lysosomal residual bodies containing the end products derived from the daily phagocytosis of rod outer segments by RPE cells. Here, we present previously recognized bis-retinoids with focus on structures and biosynthetic pathways. In addition to a brief discussion on the mutual conversion relationships of bis-retinoids, future perspectives and the medical relevance of such studies on these lipofuscin constituents are also highlighted.Keywords：Age-related macular degeneration (AMD);Lipofuscin;Retinal pigment epithelial (RPE);Bis-retinoids;Structures;Biogenesis;Conversion relationships- 14
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Published：2022-01-05 -
Assessing the response of indigenous loquat cultivar Mardan to phytohormones for in vitro shoot proliferation and rooting
Abstract：In vitro cultures of loquat cultivar Mardan were established using shoot apices after treating with NaOCl (5%, 7%, 10%, 12%, 14% (v/v)) for 12 min and HgCl2 (0.01%, 0.05%, 0.10%, 0.20%, 0.25% (w/v)) for 2 min. A maximum survival rate of 70% was recorded after surface sterilization with 10% NaOCl. Caulogenic response was assessed on Murashige and Skoog (MS) medium fortified with assorted combinations of the cytokinins, benzylaminopurine (BAP), kinetin, and N6-(2-isopentyl)adenine (2iP). Treatment of BAP 1.5 mg/L combined with 2iP 9.0 mg/L and kinetin 1.5 mg/L was found to be optimum for shoot morphogenesis in terms of the number and subsequent growth of shoots, while the highest shoot length was yielded by the combination of BAP 0.5 mg/L, kinetin 0.5 mg/L, and 2iP 3 mg/L. Higher levels of cytokinins induced callogenesis, vitrification and stunted growth to some extent. For rhizogenesis, uniform sized micro-shoots were excised and transferred to half-strength MS medium containing auxins. The best rooting expression was observed with naphthaleneacetic acid (NAA) 1 mg/L combined with indole-3-butyric acid (IBA) 2 mg/L and paclobutrazol (PBZ) 1 mg/L.Keywords：Eriobotrya japonica;Micropropagation;Sterilization of loquat;Plant growth regulator;Shoot proliferation;Rhizogenesis- 26
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Published：2022-01-05 -
Promoting role of an endophyte on the growth and contents of kinsenosides and flavonoids of
Anoectochilus formosanus Hayata, a rare and threatened medicinal Orchidaceae plantAbstract：Anoectochilus formosanus, commonly known as “Jewel Orchid”, is a Chinese folk medicine used to treat hypertension, diabetes, and heart disease. The existence of A. formosanus is currently threatened by habitat loss, human and animal consumption, etc. The highly potent medicinal activity of A. formosanus is due to its secondary metabolites, especially kinsenosides and flavonoids. This orchid also has a unique mycorrhizal relationship. Most adult orchids rely on endophytes for mineral nutrition and have complex interactions with them, which are related to plant growth, yield and changes in secondary metabolites. This study investigated the promoting role of F-23 fungus (genus Mycena) on the biomass and contents of kinsenosides and flavonoids of A. formosanus in pot culture. The following were observed after 10 weeks of symbiotic cultivation: increased shoot height, shoot dry weight, and leaf numbers by 16.6%, 31.3%, and 22.5%, respectively; increased contents of kinsenosides, isorhamnetin-3-O-β-D-rutinoside, and isorhamnetin-3-O-β-D-glucopyranoside by 85.5%, 226.1%, and 196.0%, respectively; some hyphae in epidermal cells dyed red and/or reddish brown by safranine; and, significantly reduced number of starch grains in cortical cells. Moreover, F-23 fungus significantly improved the kinsenoside and flavonoid contents of A. formosanus. These findings supported the reports that endophytes can alter the production of secondary metabolites in their plant hosts, although further physiological, genetic and ecological analyses are warranted.Keywords：Anoectochilus formosanus;Endophyte;Secondary metabolite;Kinsenoside;Flavonoid- 20
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Published：2022-01-05 -
Fruit quality, anthocyanin and total phenolic contents, and antioxidant activities of 45 blueberry cultivars grown in Suwon, Korea
Abstract：Blueberry fruits from 45 commercial cultivars (39 northern highbush and 6 half highbush blueberry) grown in Suwon, Korea were analyzed for fruit size, soluble solids content, titratable acidity, total anthocyanin content, total phenolic content, and antioxidant activity. Fruit characteristics varied widely among the 45 blueberry cultivars. Fruit weight ranged from 0.9 to 3.6 g, soluble solids content from 8.3 to 14.3 °Brix, and titratable acidity from 0.8% to 3.6%. Antioxidant activity ranged from 0.7 to 2.1 mg of quercetin equivalents per gram of fresh berries in different blueberry cultivars. Among the 45 blueberry cultivars, high amounts of anthocyanins and polyphenols, and high antioxidant activity were observed in ‘Elliott’, ‘Rubel’, ‘Rancocas’, and ‘Friendship’.Keywords：Northern highbush blueberry;Half highbush blueberry;Functional food;Fruit quality- 119
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Published：2022-01-05 -
Anatomical studies of ovule development in the post-bloom pistils of the ‘Zuili’ plum (
Prunus salicina Lindl.)Abstract：In order to investigate the cause of poor fruit set in ‘Zuili’ plums, anatomical examinations of post-bloom pistils were conducted and the dates of young fruit drop were recorded during the growing seasons of 2008 and 2009. Pistils of cv. ‘Black Amber’ were also examined as an abundant setting control. Two major dropping periods were detected in ‘Zuili’: one during the first 5 d after full bloom (DAF) and another between 10 and 17 DAF. Anatomical analyses of the pistils at the full bloom stage revealed that half of the ovules had not developed embryos, which may have caused their early drop. In most dropped pistils collected at 17 DAF, the micropyle had not been penetrated by a pollen tube, indicating that they were not fertilized. ‘Zuili’ ovules initiated embryo division at 10–12 DAF, although thereafter embryo development was retarded when compared to the rates observed in ‘Black Amber’. Ovule fertilization failure and inactive embryo development after ovule fertilization may be the major causes of the later fruit drop observed in ‘Zuili’ plum trees.Keywords：Ovule;Development;Pistils;‘Zuili’ plum- 17
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Published：2022-01-05 -
Partial
AZFc duplications not deletions are associated with male infertility in the Yi population of Yunnan Province, ChinaAbstract：Objective:There are many reports on associations between spermatogenesis and partial azoospermia factor c (AZFc) deletions as well as duplications; however, results are conflicting, possibly due to differences in methodology and ethnic background. The purpose of this study is to investigate the association of AZFc polymorphisms and male infertility in the Yi ethnic population, residents within Yunnan Province, China.Methods:A total of 224 infertile patients and 153 fertile subjects were selected in the Yi ethnic population. The study was performed by sequence-tagged site plus/minus (STS+/−) analysis followed by gene dosage and gene copy definition analysis. Y haplotypes of 215 cases and 115 controls were defined by 12 binary markers using single nucleotide polymorphism on Y chromosome (Y-SNP) multiplex assays based on single base primer extension technology.Results:The distribution of Y haplotypes was not significantly different between the case and control groups. The frequencies of both gr/gr (7.6% vs. 8.5%) and b2/b3 (6.3% vs. 8.5%) deletions do not show significant differences. Similarly, single nucleotide variant (SNV) analysis shows no significant difference of gene copy definition between the cases and controls. However, the frequency of partial duplications in the infertile group (4.0%) is significantly higher than that in the control group (0.7%). Further, we found a case with sY1206 deletion which had two CDY1 copies but removed half of DAZ genes.Conclusions:Our results show that male infertility is associated with partial AZFc duplications, but neither gr/gr nor b2/b3 deletions, suggesting that partial AZFc duplications rather than deletions are risk factors for male infertility in Chinese-Yi population.Keywords：Azoospermia factor c (AZFc);AZFc polymorphism;b2/b3;gr/gr;Infertility- 134
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Published：2022-01-05 -
Computational prediction of cleavage using proteasomal in vitro digestion and MHC I ligand data
Abstract：Proteasomes are responsible for the production of the majority of cytotoxic T lymphocyte (CTL) epitopes. Hence, it is important to identify correctly which peptides will be generated by proteasomes from an unknown protein. However, the pool of proteasome cleavage data used in the prediction algorithms, whether from major histocompatibility complex (MHC) I ligand or in vitro digestion data, is not identical to in vivo proteasomal digestion products. Therefore, the accuracy and reliability of these models still need to be improved. In this paper, three types of proteasomal cleavage data, constitutive proteasome (cCP), immunoproteasome (iCP) in vitro cleavage, and MHC I ligand data, were used for training cleave-site predictive methods based on the kernel-function stabilized matrix method (KSMM). The predictive accuracies of the KSMM+pair coefficients were 75.0%, 72.3%, and 83.1% for cCP, iCP, and MHC I ligand data, respectively, which were comparable to the results from support vector machine (SVM). The three proteasomal cleavage methods were combined in turn with MHC I-peptide binding predictions to model MHC I-peptide processing and the presentation pathway. These integrations markedly improved MHC I peptide identification, increasing area under the receiver operator characteristics (ROC) curve (AUC) values from 0.82 to 0.91. The results suggested that both MHC I ligand and proteasomal in vitro degradation data can give an exact simulation of in vivo processed digestion. The information extracted from cCP and iCP in vitro cleavage data demonstrated that both cCP and iCP are selective in their usage of peptide bonds for cleavage.Keywords：Cytotoxic T lymphocyte epitopes;Kernel function;Proteasome;Stabilized matrix method- 17
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Published：2022-01-05 -
Discrimination between
Demodex folliculorum (Acari: Demodicidae) isolates from China and Spain based on mitochondrialcox1 sequencesAbstract：For a long time, classification of Demodex mites has been based mainly on their hosts and phenotypic characteristics. A new subspecies of Demodex folliculorum has been proposed, but not confirmed. Here, cox1 partial sequences of nine isolates of three Demodex species from two geographical sources (China and Spain) were studied to conduct molecular identification of D. folliculorum. Sequencing showed that the mitochondrial cox1 fragments of five D. folliculorum isolates from the facial skin of Chinese individuals were 429 bp long and that their sequence identity was 97.4%. The average sequence divergence was 1.24% among the five Chinese isolates, 0.94% between the two geographical isolate groups (China (5) and Spain (1)), and 2.15% between the two facial tissue sources (facial skin (6) and eyelids (1)). The genetic distance and rate of third-position nucleotide transition/transversion were 0.0125, 2.7 (3/1) among the five Chinese isolates, 0.0094, 3.1 (3/1) between the two geographical isolate groups, and 0.0217, 4.4 (3/1) between the two facial tissue sources. Phylogenetic trees showed that D. folliculorum from the two geographical isolate groups did not form sister clades, while those from different facial tissue sources did. According to the molecular characteristics, it appears that subspecies differentiation might not have occurred and that D. folliculorum isolates from the two geographical sources are of the same population. However, population differentiation might be occurring between isolates from facial skin and eyelids.Keywords：Demodex folliculorum;cox1 partial sequences;Divergence;Genetic relationship;Phylogenetic tree- 16
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Published：2022-01-05 -
Influence of induced ciprofloxacin resistance on efflux pump activity of
Klebsiella pneumoniae Abstract：Objective:The efflux pump (EP) is one of the major mechanisms of antibiotic resistance in Klebsiella pneumoniae. However, there are few reports on the effect of the abuse of antibiotic use on the activity of EPs. To determine whether the use of low efficacy antibiotics has any effect on the activity of EPs and induces drug resistance in K. pneumoniae, we investigated the effect of ciprofloxacin on the activity of EPs in K. pneumoniae strains.Methods:Sixteen susceptible K. pneumoniae strains were isolated from patients and their minimum inhibitory concentrations (MICs) of ciprofloxacin were measured in the absence and presence of the pump inhibitor carbonyl cyanide m-chlorophenyl hydrazone (CCCP). The strains were then induced with a gradient of ciprofloxacin until the MICs of the strains showed no further increase, to obtain induced resistant strains. The EP activities of the strains before and after induction were compared using EP inhibition and ethidium bromide (EtBr) accumulation assays.Results:The MIC values of the strains were 16‒256 times higher after induction than before induction. In the presence of CCCP, the MIC values of 50% of the induced strains were 2‒4-fold lower than that in the absence of this inhibitor. The EtBr accumulation assay showed that the fluorescence of EtBr in the induced cells was lower than that in the cells before induction.Conclusions:EPs are widespread in susceptible and drug-resistant K. pneumoniae strains. Induction with ciprofloxacin may increase the activity of EPs in K. pneumoniae. The EtBr accumulation assay is more sensitive than the EP inhibition assay in evaluating the activity of EPs in K. pneumoniae.Keywords：Klebsiella pneumoniae;Efflux pump;Ciprofloxacin;Antibiotic resistance- 16
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Published：2022-01-05 -
Endoscopic ultrasonographic features of gastric linitis plastica in fifty-five Chinese patients
Abstract：The objective of this study was to investigate the endosonographic appearance of gastric linitis plastica (GLP) and to study the usefulness of endoscopic ultrasonography (EUS) for the T and N staging of GLP. EUS examinations of 55 patients with histologically proven GLP were retrospectively studied. In all patients, EUS showed that lesions involved at least one-third of the circumference of the stomach. Based on the findings of the EUS, the 55 patients were divided into two groups. There were 32 (58.2%) patients in the first group. EUS of this group showed that the five sonographic layers had disappeared and had been replaced by a hypoechogenic thickening of the gastric wall. There were 23 (41.8%) patients in the second group. EUS of this group showed that the first three sonographic layers were blurred and thickened, and the fourth layer was significantly thickened. The full thickness of the gastric wall was significantly thicker in first than in the second group of patients (P<0.01). The incidence of perigastric lesions was significantly higher in the first than in the second group of patients (P<0.01). Results for the 15 patients following preoperative EUS were compared postoperatively with histopathologic findings for T and N staging. The overall diagnostic accuracy of the T stage was 73.3% and of the N stage was 60.0%. In eight patients, we used EUS to assess a therapeutic response. No response was observed in five patients and a partial response in three. EUS images of GLP are characteristic. EUS is helpful in diagnosing GLP and for assessing the T and N stages.Keywords：Gastric linitis plastica;Endoscopic ultrasonography;Diagnosis;Differentiation;Follow-up- 132
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Published：2022-01-05
Biomedicine & Biotechnology
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