Nuclear progestin receptor (pgr) knockouts in zebrafish demonstrate role for pgr in ovulation but not in rapid non-genomic steroid mediated meiosis resumption

Progestins, progesterone derivatives, are the most critical signaling steroid for initiating final oocyte maturation (FOM) and ovulation, in order to advance fully-grown immature oocytes to become fertilizable eggs in basal vertebrates. It is well-established that progestin induces FOM at least partly through a membrane receptor and a non-genomic steroid signaling process, which precedes progestin triggered ovulation that is mediated through a nuclear progestin receptor (Pgr) and genomic signaling pathway. To determine whether Pgr plays a role in a non-genomic signaling mechanism during FOM, we knocked out Pgr in zebrafish using transcription activator-like effector nucleases (TALENs) and studied the oocyte maturation phenotypes of Pgr knockouts (Pgr-KOs). Three TALENs-induced mutant lines with different frame shift mutations were generated. Homozygous Pgr-KO female fish were all infertile while no fertility effects were evident in homozygous Pgr-KO males. Oocytes developed and underwent FOM normally in vivo in homozygous Pgr-KO female compared to the wild-type controls, but these mature oocytes were trapped within the follicular cells and failed to ovulate from the ovaries. These oocytes also underwent normal germinal vesicle breakdown (GVBD) and FOM in vitro, but failed to ovulate even after treatment with human chronic gonadotropin (HCG) or progestin (17α,20β-dihydroxyprogesterone or DHP), which typically induce FOM and ovulation in wild-type oocytes. The results indicate that anovulation and infertility in homozygous Pgr-KO female fish was, at least in part, due to a lack of functional Pgr-mediated genomic progestin signaling in the follicular cells adjacent to the oocytes. Our study of Pgr-KO supports previous results that demonstrate a role for Pgr in steroid-dependent genomic signaling pathways leading to ovulation, and the first convincing evidence that Pgr is not essential for initiating non-genomic progestin signaling and triggering of meiosis resumption.

Mudskipper genomes provide insights into the terrestrial adaptation of amphibious fishes

Mudskippers are amphibious fishes that have developed morphological and physiological adaptations to match their unique lifestyles. Here we perform whole-genome sequencing of four representative mudskippers to elucidate the molecular mechanisms underlying these adaptations. We discover an expansion of innate immune system genes in the mudskippers that may provide defence against terrestrial pathogens. Several genes of the ammonia excretion pathway in the gills have experienced positive selection, suggesting their important roles in mudskippers’ tolerance to environmental ammonia. Some vision-related genes are differentially lost or mutated, illustrating genomic changes associated with aerial vision. Transcriptomic analyses of mudskippers exposed to air highlight regulatory pathways that are up- or down-regulated in response to hypoxia. The present study provides a valuable resource for understanding the molecular mechanisms underlying water-to-land transition of vertebrates.

Mudskippers are amphibious fishes that have adapted to live on mudflats. Here, the authors sequence the genomes of four different mudskipper species and highlight genetic changes that may have had an evolutionary role in the water-to-land transition of vertebrates.

Development and validation of a chronic obstructive pulmonary disease screening questionnaire in China

OBJECTIVE

To develop a brief, reliable screening questionnaire for chronic obstructive pulmonary disease (COPD) for use in primary care settings.

METHODS

We developed a COPD Screening Questionnaire (COPD-SQ) using data collected from 19,800 subjects aged ≥40 years obtained from an epidemiological study of COPD in China in 2002 (Phase I). A stepwise logistic regression method was adopted for item reduction and scoring. We then assessed the COPD-SQ through a cross-sectional study (Phase II) among 3231 subjects aged ≥40 years.

RESULTS

The final COPD-SQ consisted of seven items: age, smoking pack-years, body mass index, cough, dyspnoea, family history of respiratory diseases and exposure to biomass smoke from cooking. Using the questionnaire to screen for COPD in Phase II, we obtained high classification accuracy with an area under the curve of 0.812 (95%CI 0.786-0.838). The sensitivity, specificity and correct classification rates for COPD diagnosis were respectively 60.6%, 85.2% and 82.7% at a cut-off score of 16.

CONCLUSIONS

The COPD-SQ can be used in first-level screening for COPD.

Raltitrexed-based chemotherapy for advanced colorectal cancer

AIMS

To evaluate the efficiency and safety profile of raltitrexed-based chemotherapy in the treatment of advanced colorectal cancer.

METHODS

An electronic search was undertaken to identify randomized controlled trials comparing raltitrexed-based regimen to 5-fluorouracil-based regimen in patients with advanced colorectal cancer. The outcomes included overall survival, overall response rate and toxicities.

RESULTS

This meta-analysis included 11 studies with 4622 patients. Overall, there were no significant differences between the two regimens in terms of overall survival (HR=1.06, 95% CI: 0.96-1.17, P=0.23) or overall response rate (RR=1.09, 95% CI: 0.86-1.38, P=0.47). In subgroup analysis, patients in raltitrexed/oxaliplatin group had significantly higher partial response (RR=1.53, 95% CI: 1.17-2.00, P=0.002), overall response rate (RR=1.42, 95% CI: 1.10-1.82, P=0.006), disease control rate (RR=1.16, 95% CI: 1.04-1.29, P=0.009) and lower progressive disease (RR=0.61, 95% CI: 0.45-0.84, P=0.002) when compared to 5-fluorouracil/leucovorin/oxaliplatin group. Occurrence of severe anemia (RR=2.23, 95% CI: 1.38-3.59, P=0.0001), asthenia (RR=2.29, 95% CI: 1.36-3.84, P=0.002), hepatic disorders (RR=7.51, 95% CI: 1.30-43.56, P=0.02), and nausea/vomit (RR=1.70, 95% CI: 1.03-2.81, P=0.04) were significantly higher with the raltitrexed arm treatment, while frequencies of grade 3/4 alopecia (RR=0.36, 95% CI: 0.26-0.50, P<0.00001) and stomatitis/mucositis (RR=0.14, 95% CI: 0.07-0.31, P<0.00001) were increased in the 5-fluorouracil group.

CONCLUSIONS

Raltitrexed-based chemotherapy regimen leads to an equivalent overall survival and response rates with acceptable toxicities compared to traditional 5-fluorouracil-based regimen in patients with advanced colorectal cancer. Raltitrexed can be a treatment option for these patients when 5-fluorouracil-based regimens are not tolerated or inappropriate.

Infectivity, transmission, and pathology of human-isolated H7N9 influenza virus in ferrets and pigs

The emergence of the H7N9 influenza virus in humans in Eastern China has raised concerns that a new influenza pandemic could occur. Here, we used a ferret model to evaluate the infectivity and transmissibility of A/Shanghai/2/2013 (SH2), a human H7N9 virus isolate. This virus replicated in the upper and lower respiratory tracts of the ferrets and was shed at high titers for 6 to 7 days, with ferrets showing relatively mild clinical signs. SH2 was efficiently transmitted between ferrets via direct contact, but less efficiently by airborne exposure. Pigs were productively infected by SH2 and shed virus for 6 days but were unable to transmit the virus to naïve pigs or ferrets. Under appropriate conditions, human-to-human transmission of the H7N9 virus may be possible.

Randomized, controlled, parallel-group trial of routine prophylaxis vs. on-demand treatment with sucrose-formulated recombinant factor VIII in adults with severe hemophilia A (SPINART)

BACKGROUND

The benefits of routine prophylaxis vs. on-demand treatment with factor VIII products have not been evaluated in controlled clinical trials in older patients with hemophilia A.

OBJECTIVES

To report results from a preplanned analysis of data from the first year of the 3-year SPINART study, which compares routine prophylaxis with on-demand treatment with sucrose-formulated recombinant FVIII (rFVIII-FS).

PATIENTS/METHODS

SPINART is an open-label, randomized, controlled, parallel-group, multinational trial. Males aged 12-50 years with severe hemophilia A, ≥ 150 days of exposure to FVIII, no FVIII inhibitors, no prophylaxis for > 12 consecutive months in the past 5 years and 6-24 bleeding episodes in the preceding 6 months were randomized 1 : 1 to rFVIII-FS prophylaxis (25 IU kg(-1) , three times weekly) or on-demand treatment. The primary efficacy endpoint, number of total bleeding episodes in the intent-to-treat population, was analyzed after the last patient had completed 1 year of follow-up. A negative binomial model was used for the primary endpoint analysis; analysis of variance was used for confirmatory analysis of annualized bleeding rates.

RESULTS

Eighty-four patients were enrolled and analyzed (n = 42 per group; mean age, 30.6 years; median treatment duration, 1.7 years). The median number of total bleeding episodes and total bleeding episodes per year were significantly lower with prophylaxis than with on-demand treatment (total, 0 vs. 54.5; total per year, 0 vs. 27.9; both P < 0.0001). No treatment-related adverse events occurred, and no patients developed FVIII inhibitors.

CONCLUSIONS

Routine prophylaxis with rFVIII-FS leads to a significant reduction in bleeding as compared with on-demand treatment. Adverse events were consistent with the established rFVIII-FS safety profile.

Induction of apoptosis by retinoids in human cervical-carcinoma cell-lines

Retinoids can inhibit the growth and modulate the differentiation of a variety of tumor cell types in vitro and in vivo. All-trans retinoic acid (ATRA) and N-(4-hydroxyphenyl)retinamide (4HPR) are currently being evaluated in clinical trials for their potential use in cancer chemoprevention and therapy. We compared the effects of these retinoids on 10 human cervical carcinoma cell lines. Four of the 10 cell lines showed dramatic morphological changes and the other 5 exhibited decreased cell density after treatment with 10 mu M 4HPR, whereas few changes were induced by 10 mu M ATRA. Cell rounding and detachment were also observed in four of the cell lines. An analysis of DNA from both detached and attached cells after retinoid treatment has demonstrated the formation of a DNA ladder after electrophoresis in agarose gels, which indicated that some of the cell lines had undergone apoptosis. Induction of DNA fragmentation by 4HPR but not by other retinoids (ATRA, 13-cis-RA, and 9-cis-RA) was further evidenced as early as 24 h after treatment by a quantitative assay based on the degradation of [H-3]-thymidine-labeled DNA. Ln addition, morphological changes of nuclei associated with apoptosis such as chromatin condensation were observed by propidium iodide staining of the nuclei after 4HPR treatment. These results demonstrate that 4HPR causes apoptosis in several cervical carcinoma cell lines and that it is more potent in this effect than ATRA or other RA isomers.

Nonrandom distribution of mutagen-induced chromosome breaks in lymphocytes of patients with different malignancies

Data regarding specific chromosomal alterations in most solid neoplasms are scarce because the complex changes observed in tumor biopsies are often a challenge to interpret. The present investigation using chromosomal banding, was designed to analyze exact regions of spontaneous and mutagen-induced lymphocytic chromosomal breaks and investigate if they are unique for different cancers. Tissue from three groups of individuals were included in the study, viz., normal individuals, untreated head and neck cancer patients, and untreated melanoma patients. For every individual three samples were analyzed for spontaneous, bleomycin (radiomimetic)-induced and 4-nitroquinoline-N-oxide(4NQO) (ultraviolet rays mimetic)-induced chromosome damage. The results revealed that in melanoma patients, chromosomes 1, 6, and 9 showed a significantly higher number of breaks than other chromosomes. A clustering of breaks was observed at loci 1p32, 1q32, 6p21, 6q21 and 9q11. Among the head and neck cancer patients, a significantly larger number of breaks was found in chromosomes 3 and 7 with clustering of breaks mainly in regions 3p21, 3q21, 7q22 and 7q32. Thus, it was found that regardless of the mutagen used, specific chromosomes are more susceptible to breakage than others. Our results indicate that chromosomal fragility is specific for particular cancers and that challenging the cells with mutagens reveals it at a more pronounced rate. Mutagen-induced chromosome breaks appear to be nonrandom affecting different chromosomes in different cancers. Clustering of breaks that occur in specific regions of these chromosomes might provide definite clues for molecular analysis and further in-depth studies of cancer predisposed individuals.

Engineering Streptomyces tenebrarius to synthesize single component of carbamoyl tobramycin

AIMS

To engineer Streptomyces tenebrarius for producing carbamoyl tobramycin as a main component.

METHODS AND RESULTS

The aprH-M gene fragment (apramycin biosynthetic gene from GenBank) in S. tenebrarius Tt49 was knocked out by genetic engineering to form S. tenebrarius T106 (ΔaprH-M). Compared to the wild-type strain, mutant strain T106 (ΔaprH-M) no longer produced apramycin, while mainly synthesize carbamoyl tobramycin. TLC and HPLC-MS analyses indicated that the mutant strain significantly increased the production of carbamoyl tobramycin.

CONCLUSIONS

The metabolic flow for the apramycin and its analogues biosynthesis was blocked by disrupting the aprH-M gene clusters. The aprH-M gene clusters might be essential for the biosynthesis of apramycin. The mutant strain T106 mainly synthesized carbamoyl tobramycin.

SIGNIFICANCE AND IMPACT OF STUDY

The mutant T106 mainly produces carbamoyl tobramycin without synthesizing apramycin, which will reduce cost of postextraction from fermentation products. Therefore, it has good prospects for industrial application.

WW domain-mediated interaction with Wbp2 is important for the oncogenic property of TAZ

The transcriptional co-activators YAP and TAZ are downstream targets inhibited by the Hippo tumor suppressor pathway. YAP and TAZ both possess WW domains, which are important protein–protein interaction modules that mediate interaction with proline-rich motifs, most commonly PPXY. The WW domains of YAP have complex regulatory roles as exemplified by recent reports showing that they can positively or negatively influence YAP activity in a cell and context-specific manner. In this study, we show that the WW domain of TAZ is important for it to transform both MCF10A and NIH3T3 cells and to activate transcription of ITGB2 but not CTGF, as introducing point mutations into the WW domain of TAZ (WWm) abolished its transforming and transcription-promoting ability. Using a proteomic approach, we discovered potential regulatory proteins that interact with TAZ WW domain and identified Wbp2. The interaction of Wbp2 with TAZ is dependent on the WW domain of TAZ and the PPXY-containing C-terminal region of Wbp2. Knockdown of endogenous Wbp2 suppresses, whereas overexpression of Wbp2 enhances, TAZ-driven transformation. Forced interaction of WWm with Wbp2 by direct C-terminal fusion of full-length Wbp2 or its TAZ-interacting C-terminal domain restored the transforming and transcription-promoting ability of TAZ. These results suggest that the WW domain-mediated interaction with Wbp2 promotes the transforming ability of TAZ.

Persistent T1 hypointensity as an MRI marker for treatment efficacy in multiple sclerosis

BACKGROUND

MRI is often used as primary outcome measure in phase II clinical trials in multiple sclerosis (MS). Since persistent T1 hypointense lesions are a surrogate parameter for axonal damage and demyelination, they may serve as a marker for monitoring the efficacy of neuroprotective drugs. At present, a power analysis using black hole (BH) evolution as primary outcome measure has not been performed.

OBJECTIVE

To assess the feasibility of using BH evolution on serial brain MR images as primary outcome measure in proof of concept studies in MS.

METHODS

MRI-data obtained from 169 active RRMS patients were analysed for BH evolution by determining the cumulative number of contrast enhancing lesions (CEL) evolving into a persistent black hole (PBH) after 3 months. With a parametric simulation procedure, based on a statistical distribution fitting the data, sample sizes were calculated.

RESULTS

21.2% of the total number of CELs observed during the study period evolved into a PBH. Ring enhancing lesions evolved most frequently into a PBH (59.4%), followed by lesions larger than 10 mm (57.4%) and periventricular CELs (30.6%). The simulation procedure, based on the statistical negative binomial (NB) model resulted in a sample sizes between 200 subjects and 30 subjects per arm, for treatment effects ranging from 50% to 90% reduction of the number of CELs evolving into a PBH, respectively.

CONCLUSION

To perform a MRI monitored phase II clinical trial with a feasible sample size, using the evolution of CELs into PBHs as primary outcome parameter, a potent drug is required to obtain sufficient power.

Variation with semilunar periodicity of plasma steroid hormone production in the mudskipper Boleophthalmus pectinirostris

Variation in the production of the plasma steroid hormones E(2), 17alpha-OHP and T in females and T and 11-KT in males, was investigated in the mudskipper Boleophthalmus pectinirostris during the spawning season. Females with oocytes at the vitellogenic stage (GSI 5.97-6.86%) and mature males with GSI of 0.255-0.288% were collected at intervals of 3-4 days within the two complete semilunar cycles from May 31 to June 30, 2006. The results showed that variations in the levels of plasma steroid hormones were synchronized obviously with semilunar periodicity in both females and males. Each steroid hormone level exhibited two cycles, each cycle with a peak. In females, the first peaks in plasma E(2), 17alpha-OHP and T levels were observed 3 days after the first lunar quarter, and the second ones, 4 days after the last lunar quarter. In males, the first peaks of plasma T and 11-KT levels occurred 3 days after the first lunar quarter, and the second ones, at the last lunar quarter. The fact that, in the present study, changes in the levels of plasma steroid hormones were synchronized with semilunar periodicity, although the fish were at the same stages of gonadal development, suggests that variation of plasma steroid hormones is basically regulated by biological rhythms (Zeitgebers), and that tidal movement (with its semilunar periodicity) is the major environmental factor stimulating steroid hormone production in B. pectinirostris.

Activated Src kinase is expressed in malignant pleural mesothelioma tumors; dasatinib inhibition leads to cytotoxicity, cell cycle inhibition, and prevention of invasion and migration

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Background: Malignant pleural mesothelioma (MPM) is a lethal disease with few effective therapeutic options. We sought to determine whether Src, a non-receptor tyrosine kinase, could be a new therapeutic target in MPM and to establish the potential therapeutic use of pharmacologic Src inhibitors in this disease. Methods: We analyzed four MPM cell lines (MSTO-211H, NCI-H28, NCI-H2052, and NCI- H2452) for immunohistochemical (IHC) expression of total and phosphorylated Src (Tyr 419, Tyr 530). These cell lines were treated with dasatinib, a Src inhibitor, and evaluated for apoptosis, cell cycle analysis, and migration and invasion. Downstream signaling events were studied by Western blot analysis. We also conducted IHC analyses with total Src, phosphorylated Src Tyr 419 (p-Src Tyr 419), and phosphorylated Src Tyr 530 on 46 archived MPM tumor specimens and correlated the biomarker results with the clinical outcome. Results: All four MPM cell lines expressed total and activated Src (p-Src Tyr 419). Three of the four cell lines were sensitive in vitro to cytotoxicity by dasatinib with inhibition of migration and invasion, cell cycle inhibition, and apoptosis. Treatment with dasatinib inhibited several pathways downstream of Src. In the archived MPM tumor specimens, Src protein was highly expressed on IHC analysis in tumor cells, but that expression did not correlate with overall or progression-free survival. However, expression of activated Src (p-Src Tyr 419) on the tumor cell membrane was higher in patients with stage 4 disease; the presence of metastasis correlated with higher membrane (P = 0.03) and cytoplasmic (P = 0.04) expression of p-Src Tyr 419. MPM nodal involvement at N1 was associated with the highest membrane expression of inactive Src (p-Src Tyr 530) (P = 0.02), whereas N2 disease was associated with the lowest expression. No gene mutations in Src exon 12 were found in the cell lines or tumor specimens. Conclusions: Activated Src may have an important role in survival, metastasis, and invasion in MPM, and targeting Src may be an important therapeutic strategy.

No significant financial relationships to disclose.

Clinical and pathological prognostic markers for survival in adult patients with post-transplant lymphoproliferative disorders: BCL2 as a prognostic marker

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Background: PTLD is the most serious hematological complications of solid-organ transplantation. We determined clinical and immunohistopathological prognostic factors for overall survival (OS) in patients with PTLD. Methods: Eighty-four patients with PTLD between 1980 and 2004 at University of Pittsburgh were identified. Immunohistochemistry staining was performed on tumor at diagnosis for BCL2, BCL6, cMYC, p53, PS6k, HSP90 and NFkB. Univariate associations between individual clinical and immunohistopathological features and OS were compared using Cox proportional hazard models. Survival curves were generated via the method of Kaplan-Meier. Results: The median age at the time of diagnosis of PTLD was 53 years. Thirty four percent of patients presented with early PTLD. Sixty-four percent of patients were EBV positive by in situ hybridization. Lung transplant was significantly related to grafted organ involvement (p=0.035). Lung and multiorgan transplants were associated with a higher risk for early PTLD (p=0.0033 and p=0.054), while renal transplant was associated with risk for late PTLD (p=0.0011). The median survival for all patients was 20.8 months, 95% CI: (7.4–77.6). On univariate analysis for OS, poor prognostic factors were identified: age of transplant >60 yr (p=0.02), multiorgan transplant (p=0.02), ECOG>2 (p<0.0001), grafted organ involvement and extranodal disease at the time of diagnosis (p<0.011), early PTLD (p<0.0001), and elevated white blood cell count (WBC) 1 month prior to diagnosis (p=0.01). Good prognostic factors included late PTLD, monomorphic disease, CD20 positive and rituximab use. Only BCL2 strongly correlated with prognosis (p=0.002). A final clinico-pathological model for survival was constructed using three factors: ECOG >2, elevated WBC one month prior diagnosis and BCL2 overexpression. Patients with these three risk factors had median survival of 10 days (95% CI: 0–41), in comparison with patients with none of these risk factors had median survival of 1,414 days. Conclusions: Patients who had 3 factors ECOG >2, elevated WBC one month prior diagnosis, and BCL2 overexpression in tumor tissue had worse median survival than the patients with none of these three factors.

No significant financial relationships to disclose.

Allelic distribution of HLA class I genes in the Tibetan ethnic population of China

Tibetans live in Qinghai-Tibet Plateau rising about 4000 m a.s.l. in south-west China. Archaeological evidences suggested that there have been humans living in Tibet at least 5000 years ago. However, Tibetan earlier history remains elusive. In the present study, allelic distribution of human leucocyte antigen (HLA)-A, -B and -Cw in 158 unrelated Tibetan Chinese was investigated using sequencing-based typing methods, and a total of 25 HLA-A, 45 HLA-B and 20 HLA-Cw alleles were identified. A*24G1 (27.2%), B*51G1 (16.8%), Cw*04G1 (13.3%) and Cw*070201G1 (13.3%) are the most common HLA-A, -B and -Cw alleles. The most frequently detected haplotypes were A*24G1-B*51G1-Cw*140201 (3.6%), A*24G1-B*51G1 (6.8%), A*02G1-Cw*070201G1 (6.5%) and B*51G1-Cw*140201 (5.0%). Chi-squared test suggested that all three loci fitted the Hardy-Weinberg expectations. No evidence for a departure from selective neutrality at the HLA-A and -B loci was observed. However, significant departure of the observed homozygosity from the expected values was found for HLA-Cw. Though the contemporary Tibetans inhabit the south-west China, Nei's genetic distance measure based on frequencies of HLA-A, -B and -Cw indicated that Tibetans were closer to northern Han Chinese, Mongolian Chinese, Koreans and Japanese rather than to southern Han Chinese. The corresponding dendrogram constructed according to the neighbour-joining method supported that Tibetans separated from southern Han and located in North-East Asian cluster which included northern Han Chinese and Mongolian Chinese. These data were in good agreement with language classification and with a recent hypothesis that Tibetan might originate from northern China along Yellow river.

Helicobacter pylori VacA toxin promotes bacterial intracellular survival in gastric epithelial cells

Helicobacter pylori colonizes the gastric epithelium of at least 50% of the world's human population, playing a causative role in the development of chronic gastritis, peptic ulcers, and gastric adenocarcinoma. Current evidence indicates that H. pylori can invade epithelial cells in the gastric mucosa. However, relatively little is known about the biology of H. pylori invasion and survival in host cells. Here, we analyze both the nature of and the mechanisms responsible for the formation of H. pylori's intracellular niche. We show that in AGS cells infected with H. pylori, bacterium-containing vacuoles originate through the fusion of late endocytic organelles. This process is mediated by the VacA-dependent retention of the small GTPase Rab7. In addition, functional interactions between Rab7 and its downstream effector, Rab-interacting lysosomal protein (RILP), are necessary for the formation of the bacterial compartment since expression of mutant forms of RILP or Rab7 that fail to bind each other impaired the formation of this unique bacterial niche. Moreover, the VacA-mediated sequestration of active Rab7 disrupts the full maturation of vacuoles as assessed by the lack of both colocalization with cathepsin D and degradation of internalized cargo in the H. pylori-containing vacuole. Based on these findings, we propose that the VacA-dependent isolation of the H. pylori-containing vacuole from bactericidal components of the lysosomal pathway promotes bacterial survival and contributes to the persistence of infection.

RFamide-related peptides signal through the neuropeptide FF receptor and regulate pain-related responses in the rat

The mammalian RFamide-related peptide RFRP1 was found to signal through the neuropeptide FF 2 receptor expressed in Xenopus oocytes. The peptide induced a dose-dependent outward current, which was dependent on the simultaneous expression of GIRK1 and GIRK4 potassium channels. In neuropathic rats, RFRP1 administered intrathecally induced tactile antiallodynia and thermal antinociception, whereas in the solitary tract nucleus it produced only mechanical antihyperalgesia. Expression of the RFamide-related peptide mRNA in the rat CNS was distinctly different from that of neuropeptide FF. Most notably, the gene was not expressed in the hindbrain or spinal cord at detectable levels. However, there was a prominent group of RFamide-related peptide mRNA-expressing neurons in the central hypothalamus, in the area in and between the dorsomedial and ventromedial nuclei. The results suggest that RFamide-related peptides are potentially involved in pain regulation through a hypothalamo-medullary projection system, and possibly via action on neuropeptide FF 2 receptors. In neuropathic animals, the pain suppressive effect of RFamide-related peptide varies depending on the submodality of noxious test stimulation and the site of RFamide-related peptide administration.

Distributions of HLA class I alleles and haplotypes in Northern Han Chinese

Human leukocyte antigen (HLA) class I allelic genotypes were determined in 105 unrelated Han ethnic individuals inhabiting the northern China area. A total of 19 HLA-A alleles, 49 HLA-B alleles and 24 HLA-Cw alleles were detected. Through the analyses of two and three loci haplotypes of HLA-A, HLA-B, and HLA-C loci, 11 HLA-A-B-Cw haplotypes, 19 HLA-A-B haplotypes, 18 HLA-A-Cw haplotypes, and 24 HLA-B-Cw haplotypes with the frequencies of higher than 0.01 were revealed. The Nei's genetic distance (GD) was estimated, and the NJ dendrogram showed that Northern Han had a higher GD to Southern Han (0.233) than those to the Korean (0.138) or other Northern ethnic groups, suggesting that Northern Han had more mixed blood with the ethnic groups originally in Northeast Asia. Our results provide useful information on the further study of evolution and relationships of Chinese ethnic groups and disease association in terms of HLA class I genes.

Programmable motion and patterning of molecules on solid surfaces

Adsorbed on a solid surface, a molecule can migrate and carry an electric dipole moment. A nonuniform electric field can direct the motion of the molecule. A collection of the same molecules may aggregate into a monolayer island on the solid surface. Place such molecules on a dielectric substrate surface, beneath which an array of electrodes is buried. By varying the voltages of the electrodes individually, it is possible to program molecular patterning, direct an island to move in a desired trajectory, or merge several islands into a larger one. The dexterity may lead to new technologies, such as reconfigurable molecular patterning and programmable molecular cars. This paper develops a phase field model to simulate the molecular motion and patterning under the combined actions of dipole moments, intermolecular forces, entropy, and electrodes.

Group IIA secretory phospholipase A2 stimulates exocytosis and neurotransmitter release in pheochromocytoma-12 cells and cultured rat hippocampal neurons

Recent evidence shows that secretory phospholipase A2 (sPLA2) may play a role in membrane fusion and fission, and may thus affect neurotransmission. The present study therefore aimed to elucidate the effects of sPLA2 on vesicle exocytosis. External application of group IIA sPLA2 (purified crotoxin subunit B or purified human synovial sPLA2) caused an immediate increase in exocytosis and neurotransmitter release in pheochromocytoma-12 (PC12) cells, detected by carbon fiber electrodes placed near the cells, or by changes in membrane capacitance of the cells. EGTA and a specific inhibitor of sPLA2 activity, 12-epi-scalaradial, abolished the increase in neurotransmitter release, indicating that the effect of sPLA2 was dependent on calcium and sPLA2 enzymatic activity. A similar increase in neurotransmitter release was also observed in hippocampal neurons after external application of sPLA2, as detected by changes in membrane capacitance of the neurons. In contrast to external application, internal application of sPLA2 to PC12 cells and neurons produced blockade of neurotransmitter release. Our recent studies showed high levels of sPLA2 activity in the normal rat hippocampus, medulla oblongata and cerebral neocortex. The sPLA2 activity in the hippocampus was significantly increased, after kainate-induced neuronal injury. The observed effects of sPLA2 on neurotransmitter release in this study may therefore have a physiological, as well as a pathological role.

[Effects of BaP exposure on ultrastructures of hepatic cells of Boleophthalmus pectinirostris]

The changes of ultrastructures of hepatic cells of Boleophthalmus pectinirostris were investigated after the fish were exposed under benzo(a) pyrene in different concentrations under experimental condition. The results showed that the organelles in hepatic cells of B. pectinirostris were damaged to different extents after the fish was exposed under lower concentration of BaP (0.5 mg.L-1) for up to 7 d, in which, mitochondria and endoplasmic reticulum were the chief organelles affected by BaP exposure. While the fish was exposed under higher concentration of BaP (5 mg.L-1) for 2 h, almost all of the organelles including mitochondria and endoplasmic reticulum in hepatic cells of B. pectinirostr were affected by BaP exposure. The structures of liver cells were seriously damaged. It was demonstrated that BaP could produce multiorganalle lesions in hepatic cells of B. pectinirostris, and the severity extent of such lesions was dependent on the concentration level of BaP.