Peptides design based on the interfacial helix of integrase dimer

HIV-I integrase (IN) plays a crucial role in the retroviral life cycle. The peptides derived from the helix of IN were reported to have the potency of inhibition. We designed a series of peptides based on interface helices alpha1 and alpha5 with the aim of increasing their inhibitory activity. The helix-forming tendency and the affinity with IN were essential for interfacial peptide inhibitors. The MD simulation and AGADIR prediction both showed favorable results for the designed peptides. The binding mode and binding free energy of peptide and IN were investigated subsequently to test our design. The improvement in binding free energy compared with that of alpha1 and alpha5 indicates that some of the designed peptides may have a higher potency for inhibiting the dimerization of IN. This study provides some useful information for rational design of IN peptide inhibitor.

Intranasal co-delivery with the mouse zona pellucida 3 and GM-CSF expressing constructs enhances humoral immune responses and contraception in mice

Granulocyte-monocyte colony-stimulating factor (GM-CSF) regulates the function of antigen-presenting cells (APCs) and has been broadly used as the adjuvant. Here, we tested whether intranasal delivery of GM-CSF can improve the contraception of mouse zona pellucida 3 (mZP3) DNA vaccine. Our results showed that co-administration of GM-CSF and mZP3 DNA vaccine increased the levels of secretory IgA (sIgA) and IgG antibodies in vaginal washes and serum, respectively. Co-administration enhanced Th2 responses through improving the maturation of dendritic cells. Importantly, GM-CSF significantly reduced the fertility rate and mean litter size induced by mZP3 DNA vaccine alone without interfering the normal follicular development. These data suggest that GM-CSF could be used as adjuvant to develop immunocontraceptive vaccine.

Effects of two in-office bleaching agents with different pH on the structure of human enamel: an in situ and in vitro study

This study evaluated the effects of two in-office bleaching agents (Beyond and Opalescence Boost) with different pH on the structure and mechanical properties of human enamel in vitro and in situ. One hundred and eight enamel slabs were obtained from freshly extracted premolars. The specimens were randomly distributed into nine groups (n=12), and the human saliva (HS) in the volunteers' oral cavities was used to simulate the in situ condition: Beyond + HS, Opalescence Boost (O-Boost) + HS, Control + HS, Beyond + artificial saliva (AS), O-Boost + AS, Control + AS, Beyond + distilled water (DW), O-Boost + DW, and Control + DW. The bleaching treatments were performed on the first and eighth day, and the total bleaching time was 90 minutes. Baseline and final surface roughness (RMS), surface morphology, microhardness, and fracture toughness (FT) were measured before the treatment and on the fifteenth day, respectively. Compared with control groups, surface alterations on enamel were found in the Beyond + AS and Beyond + DW groups under atomic force microscopy evaluation. Two-way analysis of variance and Tukey test revealed that the RMS showed significant intergroup differences for both storage condition and bleaching agent, whereas microhardness and FT revealed no significant alteration. The results indicated that in-office bleaching agents with low pH values could induce enamel morphology alterations under in vitro conditions. The presence of natural HS could eliminate the demineralization effect caused by low pH.

The stretchability of Mozzarella cheese evaluated by a temperature-controlled 3-prong hook test

Stretchability is one of the most important functional properties of Mozzarella cheese, but no objective and widely accepted technique exists for evaluation; most of the cheese stretchability tests are influenced by the ambient conditions. This paper demonstrates a technique, which is novel and relatively simple, to evaluate the stretchability of Mozzarella cheese objectively. In an oil bath, melted cheese is stretched by a hook probe, controlled by an Instron tensile tester (Instron Corp., Norwood, MA); cheese strands are lifted from the melted cheese reservoir to a stretch length of 300 mm, when the load and extension data are recorded by the Instron tensile tester. This test overcomes other tests' drawbacks, such as subjective stretching speeds and variations in ambient temperature and humidity. Through the test comparison on standard Mozzarella, the modified stretching test in an oil bath has greater repeatability than the original test without oil bath. From the load and extension curve, the yield load is measured to evaluate the stretchability. In the meantime, the inversion point extension of necking is also measured based on polymer study, producing more repeatable results than the yield load. The modified 3-prong hook test was applied to Mozzarella cheese samples with different processing conditions, including the screw conditions (screw time, speed, and temperature), draining pH, calcium content, and fat content, and significant differences were found between these samples and the control sample.

RAPD analysis of genetic diversity and population structure of Elymus sibiricus (Poaceae) native to the southeastern Qinghai-Tibet Plateau, China

Genetic diversity of Elymus sibiricus (Poaceae) was examined in eight populations from the southeast Qinghai-Tibet Plateau. We detected 291 RAPD polymorphic loci in 93 samples. The percentage of polymorphic bands (PPB) was 79%. Genetic diversity (H(E)) was 0.264, effective number of alleles (N(E)) was 1.444, Shannon's information index (H(O)) was 0.398, and expected Bayesian heterozygosity (H(B)) was 0.371. At the population level, PPB = 51%, N(E) = 1.306, H(E) = 0.176, I = 0.263, and H(B) = 0.247. A high level of genetic differentiation was detected based on Nei's genetic diversity analysis (G(ST) = 32.0%), Shannon's index analysis (33.7%), and the Bayesian method (θ(B) = 33.5%). The partitioning of molecular variance by AMOVA demonstrated significant genetic differentiation within populations (60%) and among populations (40%). The average number of individuals exchanged between populations per generation (N(m)) was 1.06. The populations were found to share high levels of genetic identity. No significant correlation was found between geographic distance and pairwise genetic distance (r = 0.7539, P = 0.9996). Correlation analysis revealed a significant correlation (r = 0.762) between RAPD H(E) found in this study and ISSR H(E) values from a previous study.

Characterization of placenta-derived mesenchymal stem cells cultured in autologous human cord blood serum

Human placenta-derived mesenchymal stem cells (P-MSCs) have drawn increasing attention in the field of stem cell research due to their potential in clinical applications as well as their rich and easy to procure cell source. While studies demonstrating the potential of P-MSCs for therapeutic transplantations have been documented, a clinically compliant procedure for P-MSC expansion in vitro has yet to be established. To this end, previous studies have demonstrated that MSCs of bone marrow and cord blood origins cultured in human cord blood serum (hCBS) are comparable to those cultured in fetal bovine serum (FBS), indicating that hCBS may be an alternative to FBS for the development of in vitro cell expansion procedures free of animal components. However, stem cells from origins other than bone marrow or cord blood, particularly from human placental tissues, which have demonstrated a good potential for clinical applications, have not been characterized under similar conditions. In this study, in an attempt to define a clinically compliant protocol for P-MSC expansion in vitro, we examined the effects of human hCBS as a replacement for FBS on cell proliferation capacity, differentiation potential, MSC-specific phenotypic expression and the genetic stability of P-MSCs in cultures. P-MSCs expanded in vitro in autologous hCBS maintained the capacity of self‑renewal and expressed surface antigens characteristic of bone marrow-derived mesenchymal stem cells. Under differentiation conditions, the P-MSCs expanded in hCBS developed into adipogenic, osteogenic and neurogenic cell phenotypes. Chromosomal karyotyping and single cell gel electrophoresis analysis demonstrated that P-MSCs cultured in autologous hCBS were genetically stable. These results suggest that autologous hCBS may be used as an alternative to FBS for the in vitro expansion of P-MSCs for clinical applications.

Volume increases in putamen associated with positive symptom reduction in previously drug-naive schizophrenia after 6 weeks antipsychotic treatment

BACKGROUND

Brain structure appears to alter after antipsychotic administration, but it is unknown whether these alterations are associated with improvement of psychopathology in patients with schizophrenia. In this study, the authors explore this relationship.

METHOD

Altogether, 66 first-episode, drug-naive patients with schizophrenia and 23 well-matched healthy controls underwent brain magnetic resonance imaging scans at baseline. All 23 healthy controls and 42 of the patients were rescanned after 6 weeks follow-up. The patients received regular antipsychotic treatment during the 6-week period and their psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS) at baseline and 6 weeks. The difference in PANSS scores between baseline and 6 weeks was expressed as a ratio of the scores at baseline - 'PANSS reduction ratio'. A modified tensor-based morphometry procedure was applied to analyse longitudinal images. Correlations between regional volume changes, PANSS reduction ratio and antipsychotic drug dosages were explored.

RESULTS

Compared with healthy controls, there was a significant increase in grey-matter volume of the right putamen in patients after 6 weeks treatment. This volume change was positively correlated with a positive PANSS reduction score but not related to drug dosages.

CONCLUSIONS

Putaminal volume increased after 6 weeks antipsychotic treatment in first-episode schizophrenia. The increased volume was closely correlated with improved psychopathology, suggesting the putamen might be a biomarker to predict the treatment response in schizophrenia.

Combining transfer of TTF-1 and Pax-8 gene: a potential strategy to promote radioiodine therapy of thyroid carcinoma

Cotransfer of thyroid-specific transcription factor (TTF)-1 and Pax-8 gene to tumor cells, resulting in the re-expression of iodide metabolism-associated proteins, such as sodium iodide symporter (NIS), thyroglobulin (Tg), thyroperoxidase (TPO), offers the possibility of radioiodine therapy to non-iodide-concentrating tumor because the expression of iodide metabolism-associated proteins in thyroid are mediated by the thyroid transcription factor TTF-1 and Pax-8. The human TTF-1 and Pax-8 gene were transducted into the human thyroid carcinoma (K1 and F133) cells by the recombinant adenovirus, AdTTF-1 and AdPax-8. Re-expression of NIS mRNA and protein, but not TPO and Tg mRNA and protein, was detected in AdTTF-1-infected F133 cells, following with increasing radioiodine uptake (6.1-7.4 times), scarcely iodide organification and rapid iodide efflux (t(1/2) ≈ 8-min in vitro, t(1/2) ≈ 4.7-h in vivo). On contrast, all of the re-expression of NIS, TPO and Tg mRNA and proteins were detected in F133 cells coinfected with AdTTF-1 and AdPax-8. AdTTF-1- and AdPax-8-coinfected K1 and F133 cells could effectively accumulate radioiodine (6.6-7.5 times) and obviously retarded radioiodine retention (t(1/2) ≈ 25-30-min in vitro, t(1/2) ≈ 12-h in vivo) (P<0.05). Accordingly, the effect of radioiodine therapy of TTF-1 and Pax-8 cotransducted K1 and F133 cells (21-25% survival rate in vitro) was better than that of TTF-1-transducted cells (40% survival rate in vitro) (P<0.05). These results indicate that single TTF-1 gene transfer may have limited efficacy of radioiodine therapy because of rapid radioiodine efflux. The cotransduction of TTF-1 and Pax-8 gene, with resulting NIS-mediated radioiodine accumulation and TPO and Tg-mediated radioiodine organification and intracellular retention, may lead to effective radioiodine therapy of thyroid carcinoma.

Depletion and recovery of lymphoid subsets following morphine administration

BACKGROUND AND PURPOSE

Opioid use and abuse has been linked to significant immunosuppression, which has been attributed, in part, to drug-induced depletion of lymphocytes. We sought to define the mechanisms by which lymphocyte populations are depleted and recover following morphine treatment in mice.

EXPERIMENTAL APPROACH

Mice were implanted with morphine pellets and B- and T-cell subsets in the bone marrow, thymus, spleen and lymph nodes were analysed at various time points. We also examined the effects of morphine on T-cell development using an ex vivo assay.

KEY RESULTS

The lymphocyte populations most susceptible to morphine-induced depletion were the precursor cells undergoing selection. As the lymphocytes recovered, more lymphocyte precursors proliferated than in control mice. In addition, peripheral T-cells displayed evidence that they had undergone homeostatic proliferation during the recovery phase of the experiments.

CONCLUSIONS AND IMPLICATIONS

The recovery of lymphocytes following morphine-induced depletion occurred in the presence of morphine and via increased proliferation of lymphoid precursors and homeostatic proliferation of T-cells.

Population-based surveillance of extensively drug-resistant tuberculosis in Shandong Province, China

To investigate the prevalence of extensively drug-resistant tuberculosis (XDR-TB) in Chinese populations, we analyzed the drug resistance profiles of 1787 Mycobacterium tuberculosis isolates through a population-based surveillance project in Shandong Province, China. We found 330 (18.5%; 95%CI 16.1-20.3) isolates resistant to ≥1 first-line drug and 65 (3.6%; 95%CI 2.9-4.6) multidrug-resistant (MDR) isolates, of which 13 (20.0%; 95%CI 11.9-31.4) were XDR; 47/65 MDR-TB isolates (70.8%; 95%CI 58.2-81.4) were resistant to fluoroquinolones. Our results indicate that inadequate application of second-line anti-tuberculosis drugs has caused increased prevalence of XDR-TB in certain Chinese populations.

Ossifying parosteal lipoma of the mandible: a case report and review of the literature

Parosteal lipoma is an unusual kind of lipoma and occurs in intimate association with the underlying periostium of the bone. Parosteal lipomas mostly affect the long bones and involvement of the mandible is rare. We report a case of ossifying parosteal lipoma of the mandible in which CT was effective in diagnosis and showed a well-circumscribed mass of fat attenuation containing areas of ossification and branch-like bony protuberances from adjacent cortical bone. Microscopic examination revealed that the mass was composed of mature fat cells without nuclear hyperchromasia or atypia. Layers of bone and ossification were found inside. Although rare, it should be considered as a differential diagnosis of teratoma, osteochondroma and osteosarcoma.

Vitamin C enhances the in vitro development of porcine pre-implantation embryos by reducing oxidative stress

Vitamin C (Vc) is a natural compound supplemented to culture media to guarantee the appropriate reactive oxygen species (ROS) level, as well as protect cells from oxidative damage and apoptosis. The current study was conducted to determine the effects of Vc (0, 2.5, 5, 10, 20 and 40 μg/ml) on the ROS production, developmental ability and quality of in vitro produced porcine parthenotes. The results show that: (i) the ROS levels in the embryos significantly decrease in the Vc-treated groups compared with the control (p < 0.05), (ii) the rates of blastocyst formation and total cell numbers in each blastocyst are significantly higher in the Vc-treated groups than in the control (p < 0.05); the optimum concentration of Vc is 20 μg/ml, (iii) the relative expression of Bcl-xL significantly increases and that of Bax is downregulated after Vc treatment. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling analysis indicates that the ratio of apoptotic cells in the blastocyst is also significantly lower in Vc-treated groups (p < 0.05) and (iv) Vc treatment can also increase the expression of the Nanog gene in porcine embryos, with a fivefold increase in 20 μg/ml Vc treatment compared with the control (p < 0.05). Therefore, Vc improves the development of porcine embryos by reducing the ROS levels. Vc addition in PZM-3 medium can decrease the number of apoptotic cells and increase the cell numbers in blastocysts to produce high-quality porcine embryos in vitro.

185 PARTHENOGENETIC ACTIVATION OF SIKA DEER (CERVUS NIPPON TEMMINCK) OOCYTES WITH CHEMICALS

Parthenogenetic activation of the oocyte represents an important step in the somatic cell nuclear transfer. The aim of the present study was to establish optimizing conditions for parthenogenetic activation of Sika deer oocytes necessary for cloning Sika deer. Sika deer ovaries were collected from a slaughter house during oestrus season (October and November), placed into saline (25°C) supplemented with 1% (v/v) penicillin and streptomycin and transported into the laboratory within 4 h. The small vesicular follicles (diameter, 2–5 mm) on the ovarian surface were incised with a scalpel in a Petri dish containing PBS to release the cumulus–oocyte complexes (COC). Only COC with uniform cytoplasm and at least 3 layers of compact cumulus cells were cultured in vitro for 24 h. The media of in vitro maturation (IVM) was TCM-199 supplemented with 10% fetal bovine serum, 10 μg mL–1 FSH, 1 μg mL–1 LH, 0.2 mM cysteamine and 50 ng mL–1 epidermal growth factor. After IVM, the cumulus cells were denuded with 0.2% hyaluronidase in TCM-199 at 38.5°C by pipetting. The cumulus-free Sika deer oocytes were stimulated by 1 of the following treatments: 1) ethanol + 6-DMAP, treated with 7% ethanol for 7 min and 2 mM 6-dimethylaminopurine (6-DMAP) in DSOF for 4 h; or 2) ionomycin + 6-DMAP, treated with 5 μM ionomycin for 5 min and 2 mM 6-DMAP in DSOF for 4 h. Then, oocytes were transferred into culture media for 7 days [Day 0 (D0) = activation]. On D3, embryos were transferred into fresh DSOF drops supplemented with 10% (v/v) fetal bovine serum. All cultures were overlaid with mineral oil and kept in a humidified modular incubation chamber gassed with 5% CO2. Effects of these chemicals on oocyte activation were then examined and compared with the controls, in which oocytes were cultured in TCM-199 for 4 h without chemical supplement. Our results showed that rates of cleavage, morula and blastocyst were 72.7, 43.9 and 32.4% (n = 139), respectively, by treatment with ionomycin + 6-DMAP. And rates of cleavage, morula and blastocyst were 61.1, 29.7 and 17.8% (n = 134), respectively, by treatment with ethanol + 6-DMAP. However, the rates of cleavage, morula and blastocyst were 5, 0 and 0% (n = 101) in the control group. Meanwhile, the rates of oocyte cleavage (72.7% vs 61.1%), morula (43.9% vs 29.7%) and blastocyst (32.4% vs 17.8%) between 2 treatments of ionomycin + 6-DMAP and ethanol + 6-DMAP were significantly different (P < 0.05). In conclusion, parthenogenetic activation of Sika deer oocytes with ionomycin + 6-DMAP is more effective than that with ethanol + 6-DMAP. These results have begun to elucidate parameters important for animal modeling and cloning with the Sika deer and should facilitate the development of genetically defined animal models in this species. This work was supported by the grant from the China Postdoctoral Science Foundation (No. 20090451135).

59 HISTONE DEACETYLASE 1 KNOCK-DOWN IN BOVINE FIBROBLAST CELLS AND CLONED EMBRYOS

Histone deacetylase 1 (HDAC1) is one of the most conserved enzymes present in the nuclei of cells. It was thought to be the most important enzyme in the regulation of histone deacetylation process. However, the function of HDAC1 in bovine fibroblast cells and nuclear transfer embryos is not clear. In the present study, sh299 (5′GCAAGCAGATGCAGAGATTTCAAGA GAATCTCTGCATCTGCTTGCTT3′) targeting of HDAC1 mRNA sequence was designed in the PGP/U6/GFP vector (short hairpin RNA, shRNA, expression vector). The sh299 vector was transfected into bovine fibroblast cells by transfection reagent FuGENE HD and the positive cells were identified by the expression of green fluorescent protein (GFP). Histone deacetylase 1 down-regulation in bovine fibroblast cells was measured by quantitative real-time PCR (qRT-PCR with the 2–ΔΔCT method) at 48 h after sh299 vector transfection at mRNA level. Immunocytochemistry was performed at 96 h after sh299 vector transfection to examine the HDAC1 protein level. Bovine fibroblast cells of the control group, negative control vector transfection group and sh299 vector transfection group were used as donor cells for nuclear transfer. Cleavage rates and expression of HDAC1 mRNA in bovine cloned embryos were examined at 48 h after nuclear transfer. Blastocyst rates and total cell numbers of blastocysts were examined on Day 7 post-nuclear transfer. Data were analysed with Statistics Production for Service Solution (version 16.0; SPSS) by 1-way ANOVA. A value of P < 0.05 was considered to be significantly different. Our results showed that the expression level of HDAC1 was significantly reduced by transfection of the sh299 expression vector. The GFP-positive cells showed decreased signal for HDAC1 by immunocytochemistry. It was suggested that the transfection of the sh299 expression vector reduced HDAC1 expression in bovine fibroblast cells at both mRNA level and protein level. Following nuclear transfer, expression of HDAC1 was significantly reduced in the sh299 vector transfection group (donor cells were transfected by the sh299 vector) compared to the other 2 groups. No significant difference (P > 0.05) was seen in cleavage rates among bovine cloned embryos in the sh299 vector transfection group (52.3 ± 3.4%), control group (51.1 ± 5.4%) and negative control vector transfection group (56.2 ± 3.1%). However, blastocyst rates and total cell numbers of blastocysts were significantly lower (P < 0.05) in the sh299 vector transfection group (4.2 ± 1.3% and 75.4 ± 9.2, n = 89) compared to the control group (18.2 ± 3.7% and 97.6 ± 7.3, n = 78) and negative control vector transfection group (18.9 ± 1.7% and 104.2 ± 10.3, n = 83). In conclusion, HDAC1 down-regulation in bovine fibroblast cells and cloned embryos by the sh299 expression vector indicated that HDAC1 was essential for the development of bovine cloned embryos. This work was supported by the grant from National Transgenic Animal Program (No.2009ZX08007-004B) in China.

Effects of estrogen and progestin on expression of MMP-2 and TIMP-2 in a nude mouse model of endometriosis

OBJECTIVE

The study endeavored to observe the effects of estrogen and progestin on expression of matrixmetalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) in a nude mouse model of endometriosis (EMT) and to explore the roles of MMP-2/TIMP-2 in the pathogenesis of EMT.

METHODS

Sixty nude mice were injected in the abdominopelvic cavity with human endometrial tissue and randomly divided into four hormone treatment groups (estrogen, progestin, estrogen+progestin, and saline control; n=15 per group). Implantation rates and gross morphological characteristics were assessed. Further, expression of MMP-2 and TIMP-2 in ectopic endometrial lesions was detected by immunohistochemistry.

RESULTS

The overall implantation rate of endometrial samples was 87.5% (50/60) in injected nude mice. Although there was no statistically significant difference in implantation rates between groups, the number of lesions in the progestin group was higher than that in other groups, and the size of lesions in the progestin and estrogen+progestin groups was larger than in the estrogen and control groups (p < 0.05). Further, expression levels of MMP-2 in the estrogen and estrogen+progestin groups were higher than in the progestin and control groups (p < 0.05). In contrast, expression levels of TIMP-2 in estrogen, progestin, and estrogen+progestin groups were lower than in the control group; additionally, the expression level of TIMP-2 in the progestin group was lower than in the estrogen group (p < 0.05). Finally, the ratios of MMP-2/TIMP-2 expression in the estrogen, progestin, and estrogen+progestin groups were higher than for the control group; in fact, this ratio was highest in the estrogen+progestin group (p < 0.05).

CONCLUSIONS

The nude mouse is an appropriate model for early clinical studies of EMT, specifically in the detection of MMP-2 and TIMP-2. These proteins appear important in the pathogenesis of EMT. Specifically, estrogen can raise the expression level of MMP-2 to promote ectopic implantation of endometrial tissue. Meanwhile, progestin can inhibit the expression of TIMP-2 to raise the MMP-2/TIMP-2 ratio, which can enhance invasiveness of ectopic endometrium to promote implantation.