Efficient development of polymorphic microsatellite loci for Pteroceltis tatarinowii (Ulmaceae)

Pteroceltis tatarinowii (Ulmaceae) is a scientifically and economically important temperate deciduous tree that is endemic to China. In the present study, 12 P. tatarinowii polymorphic microsatellite loci were developed using the tailed primer-M13-simple sequence repeats (TP-M13-SSR) biotin-capture method. The number of alleles per locus ranged from 2 to 10, with an average of 6.58. The observed and expected heterozygosity ranged from 0.208 to 0.958 and from 0.198 to 0.858, with average values of 0.703 and 0.710, respectively. The markers isolated in this study represent a favorable tool for further analyses of the population genetic structure and evolutionary history of this relic tree.

LITAF, HHEX, and DUSP1 expression in mesenchymal stem cells from patients with psoriasis

Psoriasis is a common chronic relapsing inflammatory skin disease, in which mesenchymal stem cells (MSCs) have been hypothesized to play an important role in abnormal localized inflammation and vascular proliferation observed in skin lesions. Previous studies have revealed abnormal gene expression patterns, DNA methylation status, and cytokine secretion of MSCs in psoriatic skin lesions, as well as some gene expression abnormalities related to inflammation and angiogenesis. We further verified the gene and protein expressions of inflammation-related lipopolysaccharide-induced tumor necrosis factor-alpha transcription factor (LITAF), dual-specificity protein phosphatase 1 (DUSP1), and angiogenesis-related hematopoietically expressed homeobox (HHEX) in MSCs derived from the skin lesions of psoriasis patients. The gene expression of LITAF, DUSP1, and HHEX in dermal MSCs was measured at the mRNA level using reverse transcription-polymerase chain reaction and the corresponding protein expression levels were analyzed by western blotting analysis. The gene and protein expression levels of LITAF, HHEX, and DUSP1 in dermal MSCs were significantly lower in psoriasis patients compared to controls. Amplification and western blotting results were consistent with our previously reported gene chip data. Our results suggest that dermal MSCs in psoriatic skin lesions may be involved in the development, progression, and regulation of localized inflammatory abnormalities by reducing the expression of LITAF, HHEX, and DUSP1, which are related to inflammation and angiogenesis.

Breeding of a target genotype variety based on identified chalkiness marker-QTL associations in rice (Oryza sativa L.)

The aim of this study was to breed a target genotype variety based on the identified chalkiness marker-QTL (quantitative trait locus) associations in rice. First, a permanent mapping population of rice that consisted of 525 recombinant inbred lines (RILs), which were derived from Zhenshan 97/Minghui 63, was used to identify QTLs with additive effects for rice quantitative traits and percentage of grain chalkiness (PGC). Subsequently, based on the identified QTLs in rice, the molecular marker 68923-PGC was selected to screen the low chalkiness rice line. Then, using the integration of molecular marker breeding and traditional breeding, we analyzed the genotype and phenotype of inbred lines from 525 RILs; we identified one rice variety with particularly high yields, good taste, and broad adaptability. The new variety was temporarily named RIL10, which was a high quality, high yield, and broadly adaptable variety, and it is predominantly a feature that has contributed to its geographical adaptability, which would be planted from 35°E to 18°E in Chinain China, where 2/3 of rice production occurs. RIL10 was a marker-assisted selection breeding achievement for producing a high quality, high yield, and broadly adaptable rice variety.

Effect of low temperatures on BAX and BCL2 proteins in rats with spinal cord ischemia reperfusion injury

We evaluated changes in BAX and BCL2 expression levels after spinal cord ischemia/reperfusion injury (SCII) and hypothermia during operations in rats. Eighty rats were divided into four groups: Group A (N = 20, 18°C); Group B (N = 20, 28°C); Group C (N = 20, room temperature); and Group D (N = 20, sham operation control). Spinal cord ischemia was induced for 90 min. Hypothermia was induced 15 min before, and maintained during ischemia, followed by heating to normothermia for 30 min after reperfusion. Motor function of the lower limbs was evaluated according to the Tarlov score at 72 and 168 h. For each rat, spinal cord samples were taken at 6, 24, 72 h, and 1 week to evaluate the histopathological changes, neuronal apoptosis, and BAX and BCL2 expression levels. Compared with normothermia, hypothermia significantly improved hind limb function; Group B achieved a higher score than Group A. Group D showed no neurologic deficiency, while the other groups showed various degrees. Group C exhibited greater neuronal apoptosis, higher BAX expression, but lower BCL2 expression than the other groups. Compared with Group A, BAX was expressed less and BCL2 more in Group B, and there was less apoptosis in Group B. Hypothermia preserves hind limb motor function and reduces neuronal death, thereby protecting rats from SCII. The spinal cord may be protected from SCII by inhibition of BAX and activation of BCL2. However, deep hypothermia may inhibit the expression of BCL2, resulting in a worse outcome than mild hypothermia.

Identification of conserved microRNAs and their target genes in Nile tilapia (Oreochromis niloticus) by bioinformatic analysis

MicroRNAs (miRNAs) are a class of non-coding RNAs that play important roles in posttranscriptional regulation of target genes. miRNAs are involved in multiple biological processes by degrading targeted mRNAs or repressing mRNA translation in various organisms. Their conserved nature in various organisms makes them a good source of new miRNA discovery using comparative genomic approaches. In the present study, conserved Nile tilapia (Oreochromis niloticus) miRNAs were identified using a bioinformatic strategy based on expressed sequence tag and genome survey sequence databases. A total of 21 new miRNAs were detected and were found to belong to 17 families. Using mature miRNA sequences as queries, potential targets for tilapia miRNAs were predicted using a local BLAST program and the miRanda software. Target proteins identified using miRanda and BLAST analyses included transcription factors and molecules important in metabolism, transportation, immunity, stress-related activity, growth, and development. These miRNAs and their targets in tilapia may increase the understanding of the role of miRNAs in regulating the growth and development of tilapia.

Meta-analysis of constitutive QTLs for disease resistance in maize and its synteny conservation in the rice genome

We collected data regarding 340 disease resistance quantitative trait loci (QTLs) from the maize genomic database (MaizeGDB). We constructed an integrated linkage map and analyzed this map by using the BioMercator 2.1 software with IBM2 2008 Neighbors genetic linkage map as a reference. We used a meta-analysis method to identify five "consensus" synthetic resistance QTLs located on maize chromosomes 1, 3, 6, and 10, with map intervals of 5.14, 9.00, 28.50, 1.73, and 33.34 cM, respectively. The gene and marker sequences within the five "consensus" QTLs were downloaded from the MaizeGDB website. We identified eight resistance gene analogs (RGAs), through comparison of these sequences with the resistance genes of other members of Poaceae by using the online BLASTx software. On the basis of comparative mapping between the maize genetic map and the rice physical map, 54 rice and 44 maize resistance genes were projected onto the maize IBM2 2008 Neighbors genetic linkage map by using a synteny conservation approach. Additionally, 15 resistance genes in the "consensus" QTL regions were found in two "consensus" QTLs on chromosomes 3 and 6; these resistance genes included rp3, scmv2, wsm2, RG3, RG16, RG36, RG51, RG53, scmv1, mdm1, RG5, RG8, RG10, RG14, and RG29. Our results provide valuable information for fine-mapping QTL, gene cloning, and molecular breeding for resistance in maize.

Experimental research on end-to-side anastomosis of peripheral nerves and effect of FK506 on end-to-side anastomosis

OBJECTIVE

To study the effects of end-to-side anastomosis of initially-denatured nerves at different times.

METHOD

60 male Wistar albino rats were used to fabricate animal models for the experiment on end-to-side anastomosis of peripheral nerves and 50 female Wistar albino rats were used to fabricate animal models for the experiment on the effect of FK506 on end-to-side anastomosis. Bilateral common peroneal nerve, tibialis anterior muscle electrophysiological and histological examinations, tibialis anterior muscle wet muscle weight determination, and motor end plate examination were performed 3 months after operation.

RESULTS

All recovery rates of action potential, single muscle contraction force and tetanic contraction force of the FK506 experimental group are significantly higher than those of the control group and the sectional area of muscle fiber is also higher than that of the control group of normal saline.

CONCLUSION

The best time for end-to-side anastomosis of nerves should be controlled within 2 weeks and the effect of end-to-side anastomosis of nerves will gradually become unsatisfactory. FK506 plays a role in promoting functional rehabilitation following nerve end-to-side anastomosis (Tab. 7, Fig. 4, Ref. 31).

Human papillomavirus infection among Uyghur women with cervical intraepithelial neoplasia in Xinjiang area

OBJECTIVE

To obtain the baseline data of Uyghur women for human papillomavirus (HPV) vaccination in Xinjiang.

MATERIALS AND METHODS

The authors analyzed the infection and distribution characteristics of HPV genotypes in genital tracts among Uyghur women with cervical intraepithelial neoplasia (CIN) in Urumqi of Xinjiang. A total of 1,431 eligible cases involved in this trial. All cervical samples from these patients were detected for HPV genotype.

RESULTS

High-risk HPV was identified in 24.7% of 979 histologically confirmed normal samples and 89.2% of 452 samples with CIN (p < 0.05). The prevalence of one single high-risk type, low-risk type, and multiple HPV types were 74.6%, 10.4%, and 4.2%, respectively. A single high risk HPV infection progressively increased with the severity of cervical lesions significantly (chi2 = 31.53, p < 0.01). While interestingly multiple infection and single low risk HPV infection were decreased with the severity of cervical lesions, and there was significant difference chi2 = 6.44, p <0.05; chi2 = 4.85, p < 0.05). The major prevalent high-risk HPV genotypes in 346 samples of CIN II-III were HPV-16, -58, -31, -33, -68,-18,-45, and -39. The comparison of HPV genotype distributions between normal cytology and CIN II-III was analyzed. The estimated risks for progression from viral infection to CIN II-III was highest in HPV-33 (prevalence ratio (PR), 2.62), followed by HPV-31 (2.27), HPV-16 (1.92), HPV-58 (1.62), HPV-18 (1.51), HPV-68 (1.05), and HPV-39 (1.05), suggesting that the six genotypes of HPV-31, -16, -58, -18, -68, and -39 (PR > 1) are higher-risk HPV types in Uyghur women with CIN in Urumqi of Xinjiang. There was no association between multiple infection and cervical lesion progression (0.31, PR < 1).

CONCLUSION

Except for the common HPV-16, -58, -31, -33, -18 in Xinjiang, HPV-68 and HPV-39 may be the oncogenic subtypes to Uyghur female with CIN in Xinjiang. Distinguishing these HPV subtypes may have implications for future cervical screening strategies and vaccine implementation. Multiple infections were not association with an increased risk of high-grade cervical neoplasia.

Valproic acid attenuates the suppression of acetyl histone H3 and CREB activity in an inducible cell model of Machado-Joseph disease

Machado-Joseph disease (MJD) is caused by a (CAG)n trinucleotide repeat expansion that is translated into an abnormally long polyglutamine tract. This disease is considered the most common form of spinocerebellar ataxia (SCA). In the present study, we developed stable inducible cell lines (PC12Tet-On-Ataxin-3-Q28/84) expressing ataxin-3 with either normal or abnormal CAG repeats under doxycycline control. The expression of acetyl histone H3 and the induction of c-Fos in response to cAMP were strongly suppressed in cells expressing the protein with the expanded polyglutamine tract. Treatment with valproic acid, a histone deacetylase inhibitor (HDACi), attenuated mutant ataxin-3-induced cell toxicity and suppression of acetyl histone H3, phosphorylated cAMP-responsive element binding protein (p-CREB) as well as c-Fos expression. These results indicate that VPA can stimulate the up-regulation of gene transcription through hyperacetylation. Thus, VPA might have a therapeutic effect on MJD.

First Report of Root-Knot Nematode Meloidogyne enterolobii on Sweet Potato in China

Sweet potato (Ipomoea batatas Lam.) is the fifth largest staple crop after rice, wheat, maize, and soybean in China. Sweet potato tubers were received from Zhanjiang, Guangdong Province, China, in June 2013 for research purposes. Upon inspection, the storage roots showed typical symptoms of being infected by root-knot nematodes, Meloidogyne spp.; the incidence of infection was 95%. Meloidogyne spp. females and egg masses were dissected from the symptomatic roots. Each root contained about 32 females on average (n = 20). The perineal patterns of most female specimens (n = 10) were oval shaped, with moderately high to high dorsal arch and mostly lacking obvious lateral lines. The second-stage juvenile had large and triangular lateral lips and broad, bluntly rounded tail tip. These morphological characteristics are similar to those reported in the original description of Meloidogyne enterolobii Yang & Eisenback (2). The 28S rRNA D2D3 expansion domain was amplified with primers MF/MR (GGGGATGTTTGAGGCAGATTTG/AACCGCTTCGGACTTCCACCAG) (1). The sequence obtained for this population (n = 5) of Meloidogyne sp. (GenBank Accession No. KF646797) was 100% identical to the sequence of M. enterolobii (JN005864). For further confirmation, M. incognita specific primers Mi-F/Mi-R (GTGAGGATTCAGCTCCCCAG/ACGAGGAACA TACTTCTCCGTCC), M. javanica specific primers Fjav/Rjav (GGTGCGCGATTGAACTGAGC/CAGGCCCTTCAGTGGAACTATAC), and M. enterolobii specific primers Me-F/Me-R (AACTTTTGTGAAAGTGCCGCTG/ TCAGTTCAGGCAGGATCAACC) were used for amplification of the respective DNA sequences (1). The electrophoresis results showed a bright band (~200 bp) only in the lane with the M. enterolobii specific primers. Therefore, this population of Meloidogyne sp. on sweet potato was identified as M. enterolobii based on its morphological and molecular characteristics. M. enterolobii has been reported to infect more than 20 plant species from six plant families: Fabaceae, Cucurbitaceae, Solanaceae, Myrtaceae, Annonaceae, and Marantaceae (1). To our knowledge, this is the first report of M. enterolobii on a member of the Convolvulaceae in China. Refrences: (1) M. X. Hu et al. Phytopathol. 101:1270, 2011. (2) B. Yang and J. D. Eisenback. J. Nematol. 15:381, 1983.

Electron density compression and oscillating effects on laser energy absorption in overdense plasma targets

An analytical model for energy absorption during the interaction of an ultrashort, ultraintense laser with an overdense plasma is proposed. Both the compression effect of the electron density profile and the oscillation of the electron plasma surface are self-consistently included, which exhibit significant influences on the laser energy absorption. Based on our model, the general scaling law of the compression effect depending on laser strength and initial density is derived, and the temporal variation of the laser absorption due to the boundary oscillating effect is presented. It is found that due to the oscillation of the electron plasma surface, the laser absorption rate will vibrate periodically at ω or 2ω frequency for the p-polarized and s-polarized laser, respectively. The effect of plasma collision on the laser absorption has also been investigated, which shows a considerable rise in absorption with increasing electron-ion collision frequency for both polarizations.

GmPTF1, a novel transcription factor gene, is involved in conferring soybean tolerance to phosphate starvation

Phosphorus plays a pivotal role in plant growth and development. In this study, we isolated and characterized GmPTF1, a basic helix-loop-helix (bHLH) transcription factor (TF) gene from soybean (Glycine max) with tolerance to inorganic phosphate (Pi) starvation. Alignment analysis indicated that GmPTF1 and other reported bHLH TFs share significant similarity in the region of the bHLH domain. As with OsPTF1 and other homologous Pi starvation-related bHLH TFs (His-5, Glu-9, Arg-12, and Arg-13), all recognition motifs for the G-box (CACGTG) were present in the GmPTF1 domain. Prokaryotic expression in Escherichia coli strain BL21 (DE3) plysS showed that a novel 40-kDa polypeptide was expressed when cells containing GmPTF1 were induced. The subcellular localization in cells from onion epidermis and Arabidopsis roots demonstrated that the GmPTF1 protein was found in the nucleus. Furthermore, analysis of transcription activity in yeast revealed that full-length GmPTF1 and its N-terminal and C-terminal domains could activate the histidine, adenine, and uracil reporter genes. This suggested that the N-terminal and C-terminal peptides of GmPTF1 act as transcriptional activators. When real-time quantitative polymerase chain reaction was performed, the expression of GmPTF1 under conditions of phosphate starvation was significantly induced in soybean roots of the low-Pi-tolerant variety ZH15. Moreover, the relative level of expression was much higher there than in roots of the sensitive variety NMH from days 7 to 56 of low-Pi stress. These results imply that GmPTF1 is involved in conferring tolerance to phosphate starvation in soybean.

Marsdenia tenacissima extract sensitizes MG63 cells to doxorubicin-induced apoptosis

Marsdenia tenacissima extract (MTE) is a new plate-derived biotechnology product that is frequently used, but occasionally reported, in the field of chemotherapy. In this study, we assessed the antitumor activity and related mechanisms of MTE by various biotechnological methods. The survival rates of MG63 osteosarcoma cells treated with MTE and doxorubicin were measured, individually or jointly, and the changes in cellular shape, apoptotic rates, and Fas expression were observed. The results indicated that combination of MTE and doxorubicin up-regulated Fas expression and induced apoptosis. The survival rate of combined application of 50 mg/mL MTE and 1 μg/mL doxorubicin was significantly lower than that of the individual application (P < 0.01). Other biotechnology methods also showed an apoptosis-inducing effect of combined application that was much stronger than individual application. All of these results suggested that MTE may promote the effects of doxorubicin chemotherapy, perhaps related to the up-regulation of Fas expression in tumor cells.

Eye-movement study during visual search in Chinese children with developmental dyslexia

BACKGROUND

Developmental dyslexia (DD) is a disorder in which children with normal intelligence and sensory abilities show learning deficits in reading. Abnormal eye movements have been found in DD. However, eye-movement abnormalities during visual search among Chinese children with DD remain unknown. We aimed to identify the eyemovement characteristics and search efficiency of Chinese children with DD during visual search for targets of different conceptual categories, under same-category conditions.

METHODS

We compared 32 Chinese dyslexic children and 39 non-dyslexic children in visual search tasks, which were assessed using EyeLink II High-Speed Eye Tracker (SR Research Ltd., Canada). Letters, single Chinese characters, digits, Chinese phrases, figures and facial expressions were used as stimuli. Targets were similar to distractors in meaning, phonology and/or shape.

RESULTS

A main effect of task on visual search scores and all eye-movement parameters were found. Search scores, average saccade amplitude and saccade distance were significantly smaller in the DD group than in the controls. An interaction between group and task was found for pupil diameter.

CONCLUSIONS

Unlike normal readers, children with DD had a reduction in the visual attention span and search accuracy. Besides, children with DD could not increase their mental workload with increase in task difficulty. The conceptual category of the stimulus materials significantly impacts search speed, accuracy and eye-movement parameters.

In vitro proliferation and differentiation of hepatic oval cells and their potential capacity for intrahepatic transplantation

Hepatic oval cells (HOCs) are recognized as facultative liver progenitor cells that play a role in liver regeneration after acute liver injury. Here, we investigated the in vitro proliferation and differentiation characteristics of HOCs in order to explore their potential capacity for intrahepatic transplantation. Clusters or scattered HOCs were detected in the portal area and interlobular bile duct in the liver of rats subjected to the modified 2-acetylaminofluorene and partial hepatectomy method. Isolated HOCs were positive for c-kit and CD90 staining (99.8% and 88.8%, respectively), and negative for CD34 staining (3.6%) as shown by immunostaining and flow cytometric analysis. In addition, HOCs could be differentiated into hepatocytes and bile duct epithelial cells after leukemia inhibitory factor deprivation. A two-cuff technique was used for orthotopic liver transplantation, and HOCs were subsequently transplanted into recipients. Biochemical indicators of liver function were assessed 4 weeks after transplantation. HOC transplantation significantly prolonged the median survival time and improved the liver function of rats receiving HOCs compared to controls (P=0.003, Student t-test). Administration of HOCs to rats also receiving liver transplantation significantly reduced acute allograft rejection compared to control liver transplant rats 3 weeks following transplantation (rejection activity index score: control=6.3±0.9; HOC=3.5±1.5; P=0.005). These results indicate that HOCs may be useful in therapeutic liver regeneration after orthotopic liver transplantation.

Performance improvement of resistive switching memory achieved by enhancing local-electric-field near electromigrated Ag-nanoclusters

By introducing Ag nanoclusters (NCs), ZnO-based resistive switching memory devices offer improved performance, including improved uniformity of switching parameters, and increased switching speed with excellent reliability. These Ag NCs are formed between the top-electrode (cathode) and the switching layer by an electromigration process in the initial several switching cycles. The electric field can be enhanced around Ag NCs due to their high surface curvature. The enhanced local-electric-field (LEF) results in (1) the localization of the switching site near Ag NCs, where oxygen-vacancy-based conducting filaments have a simple structure, and tend to connect Ag NCs along the LEF direction; (2) an increase in migration and recombination rates of oxygen ions and oxygen vacancies. These factors are responsible for the improvement in device performance.

Value of transvaginal sonography in diagnosing heterotopic pregnancy after in-vitro fertilization with embryo transfer

OBJECTIVES

To assess the value of transvaginal sonography (TVS) in the diagnosis of heterotopic pregnancy (HP) in the first trimester after in-vitro fertilization with embryo transfer (IVF-ET).

METHODS

This was a retrospective review of women undergoing IVF-ET between January 2005 and December 2011. Women were diagnosed with an HP using TVS if a visible intrauterine gestational sac was observed with any of the following: (i) an inhomogeneous adnexal mass; (ii) an empty extrauterine gestational sac seen as a hyperechoic ring; or (iii) a yolk sac and/or fetal pole with or without cardiac activity in an extrauterine sac.

RESULTS

Overall, 16 483 consecutive women who underwent IVF had TVS during the study. Of these, 174 cases were diagnosed on TVS as having an HP, and 10 cases were missed. Fifty-two cases were treated expectantly and were excluded from the analysis. Three types of ultrasonographic presentation of ectopic pregnancy (EP) were seen in HP patients, with a gestational sac found in 70 cases, a ring sign in 21 and an adnexal mass in 31. The sensitivity and specificity of TVS for the detection of HP were 92.4 and 100%, respectively, with positive and negative predictive values of 100 and 99.9%. The HP cases comprised 103 tubal EPs and 29 non-tubal EPs. In 93 patients (70.5%), their intrauterine pregnancy resulted in a live birth, 37 patients (28.0%) suffered an early miscarriage and two patients (1.5%) had a late miscarriage.

CONCLUSION

Early TVS performed by an experienced sonographer has a high sensitivity for making the correct diagnosis of HP after IVF-ET.

Measurement of direct photons in Au+Au collisions at √(s(NN))=200 GeV

We report the measurement of direct photons at midrapidity in Au+Au collisions at √(s(NN))=200 GeV. The direct photon signal was extracted for the transverse momentum range of 4 GeV/c<p(T)<22 GeV/c, using a statistical method to subtract decay photons from the inclusive photon sample. The direct photon nuclear modification factor R(AA) was calculated as a function of p(T) for different Au+Au collision centralities using the measured p+p direct photon spectrum and compared to theoretical predictions. R(AA) was found to be consistent with unity for all centralities over the entire measured p(T) range. Theoretical models that account for modifications of initial direct photon production due to modified parton distribution functions in Au and the different isospin composition of the nuclei predict a modest change of R(AA) from unity. They are consistent with the data. Models with compensating effects of the quark-gluon plasma on high-energy photons, such as suppression of jet-fragmentation photons and induced-photon bremsstrahlung from partons traversing the medium, are also consistent with this measurement.

Synergistic increase in the sensitivity of osteosarcoma cells to thermochemotherapy with combination of paclitaxel and etoposide

Osteosarcoma is a malignant bone tumor which is found most commonly in adolescents and young adults. Local perfusion thermochemotherapy has long been proposed as an alternative strategy for the treatment of osteosarcoma. As a standard anticancer drug, paclitaxel plays a significant role in the treatment of a number of tumors; however, little is known concerning its ability to promote thermochemotherapy. The aim of this study was to evaluate the cytotoxic effects of a combination of paclitaxel and etoposide on an osteosarcoma cell line in the presence of hyperthermia and to investigate the related mechanism. Our study indicated that 1 h after the application of a combination of 10 µg/ml paclitaxel and 5 µg/ml etoposide to OS732 cells at 43˚C, the survival rate of the cells was 14.52% which was significantly lower than when either 10 µg/ml paclitaxel (45.83%) or 5 µg/ml etoposide (43.31%) was applied alone (P<0.01). Moreover, changes in cellular morphology and apoptotic rates indicated that the apoptosis-inducing effect of the combination was much stronger than that of either drug applied individually. Fas expression levels in the OS732 cells were increased by the combination of paclitaxel and etoposide in the presence of hyperthermia. Therefore, paclitaxel enhances the thermochemotherapy of the osteosarcoma cell line and this is primarily accomplished by the upregulation of Fas expression and the induction of apoptosis.

Response of antioxidant activity and sensory quality in fresh-cut pear as affected by high O2 active packaging in comparison with low O2 packaging

Effects of active modified atmosphere packaging (initial O2/CO2: 5/5; 30/5; and 80/0) and passive packaging [initial O2/CO2: 20.8/0 (air)] on the antioxidant capacity and sensory quality of fresh-cut ‘Yaoshan’ pear stored at 4 °C for 12 days were investigated. Samples stored in high O2 (30% and 80%) packages had higher phenolics and anthocyanin contents compared with those in passive and low O2 packages. After 12 days of storage, phenolics and anthocyanin contents of 80% O2 samples were 2.5 and 12 times, respectively, higher than those in the passive package and 3 and 2 times higher than those in low O2 package. High O2 modified atmosphere packaging was effective in keeping free radical scavenging capacity as measured by the DPPH assay. The sensory evaluation indicated that surface color of cut fruits were stable for at least 12 days in the high O2 modified atmosphere packaging. The results suggested that high O2 modified atmosphere packaging could be used to inhibit browning and prolong the shelf life of fresh-cut ‘Yaoshan’ pears in spite of more than 50% loss in vitamin C content.

First Report of Leaf Spot Disease Caused by Exserohilum rostratum on Pineapple in Hainan Province, China

Pineapple (Ananas comosus (L.) Merr.) is an important perennial monocotyledonous plant that serves as an important fruit crop globally and is also produced in the Hainan Province of China where production in 2009 was 296,600 t. In July 2009, atypical symptoms of a leaf spot disease were observed on mature pineapple leaves in Chengmai County; approximately 15% of plants propagated from suckers became symptomatic after 150 to 300 days, eventually causing a 3 to 10% yield loss. In the initial infection stage, grayish white-to-yellowish white spots emerged on the leaf surfaces that ranged from 1.0 to 2.4 × 0.3 to 0.7 cm; black specks were not always present in the spots. Leaf spots also had distinctive light brown-to-reddish brown banding pattern on the edges. Several spots would often merge to form large lesions, 6.5 to 15.4 × 2.5 to 5.6 cm, covering more than 67% of the leaf surface, which can lead to death of the plant. Infected pineapple leaves collected from an orchard of Chengmai County were surface sterilized (75% ethanol for 30 s, 0.1% HgCl₂ for 2 min, and rinsed three times in sterile distilled water). Leaf pieces were placed on potato dextrose agar medium and then incubated at 25°C. The emerging fungal colonies were grayish white to brown. Similar strains were obtained from Qionghai City and Wanning City subsequently. Two isolates, ITF0706-1 and ITF0706-2, were used in confirmation of the identity of the pathogen and in pathogenicity tests. Colonies were fast growing (more than 15 mm per day at 25 to 30°C) with dense aerial mycelia. Conidia were fusiform, pyriform to oval or cylindrical, olive brown to dark brown, 3 to 10 septate (typically 5 to 8), 33.2 to 102.5 × 9.0 to 21.3 μm, with a strongly protruding hilum bulged from the basal cell, which were similar to the Type A conidia described by Lin et al. (3). The strains were subjected to PCR amplification of the internal transcribed spacer (ITS)1-5.8S-ITS2 regions with universal primer pair ITS1/ITS4. The ITS sequence comparisons (GenBank Accession Nos. JN711431 and JN711432) shared between 99.60 and 99.83% identity with the isolate CATAS-ER01 (GenBank Accession No. GQ169762). According to morphological and molecular analysis, the two strains were identified as Exserohilum rostratum (Drechs.) Leonard & Suggs. Pathogenicity experiments were conducted five times and carried out by spraying a conidial suspension (10⁵ CFU/ml) on newly matured leaves of healthy pineapple plants; plants sprayed with sterile water served as the negative control. Plants were incubated in the growth chamber at 20 to 25°C. Symptoms of leaf spot developed on test plants 7 days after inoculation while the control plants remained asymptomatic. Koch's postulates were fulfilled with the reisolation of the two fungal strains. Currently, E. rostratum is one of the most common pathogens on Bromeliads in Florida (2) and has been reported on Zea mays (4), Musa paradisiacal (3), and Calathea picturata (1) in China, but to our knowledge, this is the first report of leaf spot disease caused by E. rostratum on pineapple in Hainan Province of P.R. China. References: (1) L. L. Chern et al. Plant Dis. 95:1033, 2011. (2) R. M. Leahy. Plant Pathol. Circ. No. 393. Florida Department of Agriculture and Consumer Services Division of Plant Industry, 1999. (3) S. H. Lin et al. Australas. Plant Pathol. 40:246, 2011. (4) J. N. Tsai et al. Plant Pathol. Bull. 10:181, 2001.

Association of two glyoxalase I gene polymorphisms with nephropathy and retinopathy in Type 2 diabetes

BACKGROUND

Glyoxalase I (GLO1), which is the major enzyme that catalyzes the metabolism of methylglyoxal (MG), may play an important role in the pathogenesis of diabetic microvascular complications.

AIM

To investigate whether the C-7T and A419C polymorphisms of the GLO1 gene are associated with nephropathy and retinopathy in Chinese Type 2 diabetic patients.

SUBJECTS AND METHODS

A total of 364 Type 2 diabetic patients and 301 healthy controls were enroled in the study. Diabetic microvascular complications were determined by urinary albumin excretion measurements and ophthalmological examinations. Genetic analyses were performed using either Taqman PCR or direct sequencing. The effect of C-7T polymorphism on promoter activity was measured by reporter gene assays.

RESULTS

The albumin/ creatinine ratio (ACR) and prevalence of nephropathy and retinopathy were significantly higher in diabetic patients with GLO1 -7CC genotype than in patients with -7CT and -7TT genotypes (p=0.02, p=0.02, and p=0.04, respectively). The - 7CC genotype is independently associated with ACR (β=0.13, p=0.01) and the risk for retinopathy [odds ratio (OR): 2.30, 95% confidence interval (CI): 1.25-4.24, p<0.01]. The luciferase activity of the -7T promoter was higher than that of the -7C promoter (13.2±0.2 vs 11.7±0.8, p=0.04). No differences were found between ACR and the prevalence of nephropathy and retinopathy for A419C polymorphism in Type 2 diabetic patients.

CONCLUSIONS

GLO1 C-7T polymorphism alters promoter activity and confers susceptibility to nephropathy and retinopathy to Type 2 diabetic patients.

DNA methylation status in tissues of sheep clones

Genomic imprinting and DNA methylation play an important role in mammalian development. Many cloned animals showed heterogeneous DNA methylation profiles. However, there are fewer reports in cloned lambs because of a lack of genomic imprinting information. In this study, we investigated DNA methylation patterns in CpG islands and differentially methylated regions of putative imprinted gene Peg10 and imprinted genes Dlk1, Igf2R and H19 in cloned lambs. Five organs from two cloned lambs died shortly after birth and two normal controls were investigated. We observed normal DNA methylation profiles in cloned lambs. The imprinted genes Dlk1, Igf2R and H19 in livers, kidneys, hearts, muscles and lungs of the two cloned lambs exhibited relatively normal DNA methylation, except for Peg10 showing some differences between controls and cloned lambs. Our results indicate that somatic cell nuclear transfer-produced sheep exhibited relatively normal DNA methylation pattern and experienced normal DNA methylation reprogramming at imprinted loci.