2,108 research outputs found

    Approximate Minimum Diameter

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    We study the minimum diameter problem for a set of inexact points. By inexact, we mean that the precise location of the points is not known. Instead, the location of each point is restricted to a contineus region (\impre model) or a finite set of points (\indec model). Given a set of inexact points in one of \impre or \indec models, we wish to provide a lower-bound on the diameter of the real points. In the first part of the paper, we focus on \indec model. We present an O(21ϵdϵ2dn3)O(2^{\frac{1}{\epsilon^d}} \cdot \epsilon^{-2d} \cdot n^3 ) time approximation algorithm of factor (1+ϵ)(1+\epsilon) for finding minimum diameter of a set of points in dd dimensions. This improves the previously proposed algorithms for this problem substantially. Next, we consider the problem in \impre model. In dd-dimensional space, we propose a polynomial time d\sqrt{d}-approximation algorithm. In addition, for d=2d=2, we define the notion of α\alpha-separability and use our algorithm for \indec model to obtain (1+ϵ)(1+\epsilon)-approximation algorithm for a set of α\alpha-separable regions in time O(21ϵ2.n3ϵ10.sin(α/2)3)O(2^{\frac{1}{\epsilon^2}}\allowbreak . \frac{n^3}{\epsilon^{10} .\sin(\alpha/2)^3} )

    Molecular Cloning of a New Immunomodulatory Protein from Anoectochilus formosanus which Induces B Cell IgM Secretion through a T-Independent Mechanism

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    An immunomodulatory protein (IPAF) was purified and cloned from Anoectochilus formosanus, an Orchidaceae herbal plant in Asia. The major targeting immune cells of IPAF and its modulating effects toward B lymphocytes were investigated. Rapid amplification of cDNA ends (RACE) was conducted to clone the IPAF gene, and the obtained sequence was BLAST compared on the NCBI database. MACS-purified mouse T and B lymphocytes were stimulated with IPAF and the cell proliferation, activation, and Igs production were examined. IPAF comprised a 25 amino acids signal peptide and a 138 amino acids protein which was homologous to the lectins from Orchidaceae plant. IPAF selectively induced the cell proliferation in mouse splenic B lymphocytes but not T lymphocytes. The IPAF-induced B cells exhibited increased CD69 and MHC class II expression, and a dose- and time-dependent enhancement in IgM production. These results suggested potential benefits of IPAF to strengthen the humoral immunity

    Pilot Scale Production of Highly Efficacious and Stable Enterovirus 71 Vaccine Candidates

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    BACKGROUND: Enterovirus 71 (EV71) has caused several epidemics of hand, foot and mouth diseases (HFMD) in Asia and now is being recognized as an important neurotropic virus. Effective medications and prophylactic vaccine against EV71 infection are urgently needed. Based on the success of inactivated poliovirus vaccine, a prototype chemically inactivated EV71 vaccine candidate has been developed and currently in human phase 1 clinical trial. PRINCIPAL FINDING: In this report, we present the development of a serum-free cell-based EV71 vaccine. The optimization at each step of the manufacturing process was investigated, characterized and quantified. In the up-stream process development, different commercially available cell culture media either containing serum or serum-free was screened for cell growth and virus yield using the roller-bottle technology. VP-SFM serum-free medium was selected based on the Vero cell growth profile and EV71 virus production. After the up-stream processes (virus harvest, diafiltration and concentration), a combination of gel-filtration liquid chromatography and/or sucrose-gradient ultracentrifugation down-stream purification processes were investigated at a pilot scale of 40 liters each. Although the combination of chromatography and sucrose-gradient ultracentrifugation produced extremely pure EV71 infectious virus particles, the overall yield of vaccine was 7-10% as determined by a VP2-based quantitative ELISA. Using chromatography as the downstream purification, the virus yield was 30-43%. To retain the integrity of virus neutralization epitopes and the stability of the vaccine product, the best virus inactivation was found to be 0.025% formalin-treatment at 37 °C for 3 to 6 days. Furthermore, the formalin-inactivated virion vaccine candidate was found to be stable for >18 months at 4 °C and a microgram of viral proteins formulated with alum adjuvant could induce strong virus-neutralizing antibody responses in mice, rats, rabbits, and non-human primates. CONCLUSION: These results provide valuable information supporting the current cell-based serum-free EV71 vaccine candidate going into human Phase I clinical trials

    Effect of Aqueous Extract of Pleurotus Tuber-Regium on Ethanol Induced Peptic Ulcer in Male Wistar Rats

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    Background and Objective: There is increasing desire for pleiotropic plant-based remedies for the treatment of peptic ulcer disease due to its prevalence and the challenges associated with existing therapies. This research was conducted to investigate the effect of aqueous extract of Pleurotus tuber-regium (PT) on ethanol induced peptic ulcer in male Wistar rats. Methods: This animal experiment used 30 male Wistar rats. They were divided into five groups (6 rats each) namely: Normal control (Group A), Ulcer control (Group B), Ulcer+omeprazole treatment (Group C), PT pre-treatment ulcer (Group D), and Ulcer+PT treatment (Group E). Peptic ulcer was induced by administration of 1 ml of 80% ethanol orally to each animal from group B to E. Four hours after the induction of gastric ulcer, the rats were sacrificed, the abdomen was opened to remove the stomach for histological study and gastric content to determine the gastric juice volume (ml/4 h). Data were analyzed using IBM SPSS Version 25. Findings: Treatment of ulcer with PT in group E and omeprazole (group C) significantly decreased the free acidity (E=0.83±0.20, C=1.20±0.11, p<0.05), total acidity (E=3.10±0.60, C=9.10±0.32, p<0.05) and ulcer index (E=5.00±2.02, 7.83±4.04, p<0.05) in comparison with group B (free acidity=3.06±1.09, total acidity=22.86±2.51 and ulcer index=32.83±1.74) and group D (free acidity=4.16±0.69, total acidity=17.06±1.91 and ulcer index=35.66±1.96). Group E showed higher percentage of ulcer inhibition (84.77%) than group C (76.15%), while group D showed no inhibition. Also, there were improvements in the macroscopic and microscopic structure of the stomach tissue‎. Conclusion: The results of this study showed that P. tuber-regium extract could serve as a better alternative to standard anti-ulcer drugs and considering that it is nutraceutical, it is a safe and more affordable alternative for the treatment of peptic ulcer

    Identification of novel candidate target genes, including EPHB3, MASP1 and SST at 3q26.2–q29 in squamous cell carcinoma of the lung

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    <p>Abstract</p> <p>Background</p> <p>The underlying genetic alterations for squamous cell carcinoma (SCC) and adenocarcinoma (AC) carcinogenesis are largely unknown.</p> <p>Methods</p> <p>High-resolution array- CGH was performed to identify the differences in the patterns of genomic imbalances between SCC and AC of non-small cell lung cancer (NSCLC).</p> <p>Results</p> <p>On a genome-wide profile, SCCs showed higher frequency of gains than ACs (<it>p </it>= 0.067). More specifically, statistically significant differences were observed across the histologic subtypes for gains at 2q14.2, 3q26.2–q29, 12p13.2–p13.33, and 19p13.3, as well as losses at 3p26.2–p26.3, 16p13.11, and 17p11.2 in SCC, and gains at 7q22.1 and losses at 15q22.2–q25.2 occurred in AC (<it>P </it>< 0.05). The most striking difference between SCC and AC was gains at the 3q26.2–q29, occurring in 86% (19/22) of SCCs, but in only 21% (3/14) of ACs. Many significant genes at the 3q26.2–q29 regions previously linked to a specific histology, such as EVI1,<it>MDS1, PIK3CA </it>and <it>TP73L</it>, were observed in SCC (<it>P </it>< 0.05). In addition, we identified the following possible target genes (> 30% of patients) at 3q26.2–q29: <it>LOC389174 </it>(3q26.2),<it>KCNMB3 </it>(3q26.32),<it>EPHB3 </it>(3q27.1), <it>MASP1 </it>and <it>SST </it>(3q27.3), <it>LPP </it>and <it>FGF12 </it>(3q28), and <it>OPA1</it>,<it>KIAA022</it>,<it>LOC220729</it>, <it>LOC440996</it>,<it>LOC440997</it>, and <it>LOC440998 </it>(3q29), all of which were significantly targeted in SCC (<it>P </it>< 0.05). Among these same genes, high-level amplifications were detected for the gene, <it>EPHB3</it>, at 3q27.1, and <it>MASP1 </it>and <it>SST</it>, at 3q27.3 (18, 18, and 14%, respectively). Quantitative real time PCR demonstrated array CGH detected potential candidate genes that were over expressed in SCCs.</p> <p>Conclusion</p> <p>Using whole-genome array CGH, we have successfully identified significant differences and unique information of chromosomal signatures prevalent between the SCC and AC subtypes of NSCLC. The newly identified candidate target genes may prove to be highly attractive candidate molecular markers for the classification of NSCLC histologic subtypes, and could potentially contribute to the pathogenesis of the squamous cell carcinoma of the lung.</p

    Guillain-Barré Syndrome and Preceding Infection with Campylobacter, Influenza and Epstein-Barr Virus in the General Practice Research Database

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    BACKGROUND: A number of infectious agents have previously been suggested as risk factors for the development of Guillain-Barré syndrome (GBS), but robust epidemiologic evidence for these associations is lacking. METHODS AND FINDINGS: We conducted a nested case-control study using data from the United Kingdom General Practice Research Database between 1991 and 2001. Controls were matched to cases on general practice clinic, sex, year of birth and date of outcome diagnosis in their matched case. We found positive associations between GBS and infection with Campylobacter, Epstein-Barr virus and influenza-like illness in the previous two months, as well as evidence of a protective effect of influenza vaccination. After correction for under-ascertainment of Campylobacter infection, the excess risk of GBS following Campylobacter enteritis was 60-fold and 20% of GBS cases were attributable to this pathogen. CONCLUSIONS: Our findings indicate a far greater excess risk of GBS among Campylobacter enteritis patients than previously reported by retrospective serological studies. In addition, they confirm previously suggested associations between infection due to Epstein-Barr virus infection and influenza-like illness and GBS. Finally, we report evidence of a protective effect of influenza vaccination on GBS risk, which may be mediated through protection against influenza disease, or result from a lower likelihood of vaccination among those with recent infection. Cohort studies of GBS incidence in this population would help to clarify the burden of GBS due to influenza, and any potential protective effect of influenza vaccination

    Surveillance of Airborne Adenovirus and Mycoplasma pneumoniae in a Hospital Pediatric Department

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    This investigation evaluated the distributions of airborne adenovirus and Mycoplasma pneumoniae in public areas in the pediatric department of Children's Hospital in northern Taiwan. The airborne viral and bacterial concentrations were evaluated twice a week for a year using filter sampling with an airflow rate of 12 liters per minute for eight hours in the pediatric outpatient department and 24 hours in the pediatric emergency room. Real-time polymerase chain reaction assays were conducted for analysis. Approximately 18% of the air samples from the pediatric emergency room were found to contain adenovirus. Approximately forty-six percent of the air samples from the pediatric outpatient department contained Mycoplasma pneumoniae DNA products. High detection rates of airborne adenovirus DNA were obtained in July and August in the pediatric public areas. Airborne Mycoplasma pneumoniae was detected only in July in the pediatric emergency room and the peak levels were found from August to January in the pediatric outpatient department. Airborne particles that contained adenovirus and Mycoplasma pneumoniae were the most prevalent in the pediatric public areas. The potential relationship between these airborne viral/bacterial particles and human infection should be examined further
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