1,279 research outputs found

    The structural basis of actinomycin D–bindinginduces nucleotide flipping out, a sharp bendand a left-handed twist in CGG triplet repeats

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    The potent anticancer drug actinomycin D (ActD)functions by intercalating into DNA at GpC sites,thereby interrupting essential biological processesincluding replication and transcription. Certainneurological diseases are correlated with the expansionof (CGG)n trinucleotide sequences, whichcontain many contiguous GpC sites separated by asingle G:G mispair. To characterize the binding ofActD to CGG triplet repeat sequences, the structuralbasis for the strong binding of ActD to neighbouringGpC sites flanking a G:G mismatch has beendetermined based on the crystal structure of ActDbound to ATGCGGCAT, which contains a CGGtriplet sequence. The binding of ActD molecules toGCGGC causes many unexpected conformationalchanges including nucleotide flipping out, a sharpbend and a left-handed twist in the DNA helix via atwo site-binding model. Heat denaturation, circulardichroism and surface plasmon resonance analysesshowed that adjacent GpC sequences flanking aG:G mismatch are preferred ActD-binding sites. Inaddition, ActD was shown to bind the hairpin conformationof (CGG)16 in a pairwise combination andwith greater stability than that of other DNAintercalators. Our results provide evidence of apossible biological consequence of ActD bindingto CGG triplet repeat sequences

    Concurrent Papillary Thyroid Cancer with Pituitary ACTH-secreting Tumor

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    Concomitant thyroid cancer with pituitary tumor is uncommon. This study reports a case of advanced papillary thyroid carcinoma with pituitary adrenocorticotropic hormone (ACTH)-secreting tumor. A 58-year-old male patient had thyroid cancer in 1991 and presented with headache caused by pituitary tumor with apoplexy in 1993. Due to hypopituitarism, the patient underwent radioactive iodide (131I) for detection and treatment of metastatic thyroid cancer after the use of recombinant human thyroid-stimulating hormone (rhTSH) in 2000. During follow-up for thyroid cancer 201thallium scan proved to be an effective tool for detecting metastatic thyroid cancer in the patient without pituitary TSH reserve. Pituitary ACTH-secreting tumor was confirmed in 2001 based on the high serum ACTH level and positive immunohistochemical stain for ACTH. The patient had no Cushingoid features. Moreover, serum ACTH levels were 337 and 232 pg/mL with normal serum cortisol and urine-free cortisol. Although the patient underwent three operations and a total of 370 mCi 131I therapy for recurrent thyroid cancer, the cancer continued to progress. Finally, the patient died of pneumonia with septic shock 12 years after the diagnosis of thyroid cancer. [J Formos Med Assoc 2007;106(4):330-335

    Virus-like particle secretion and genotype-dependent immunogenicity of dengue virus serotype 2 DNA vaccine

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    Dengue virus (DENV), composed of four distinct serotypes, is the most important and rapidly emerging arthropod-borne pathogen and imposes substantial economic and public health burdens. We constructed candidate vaccines containing the DNA of five of the genotypes of dengue virus serotype 2 (DENV-2) and evaluated the immunogenicity, the neutralizing (Nt) activity of the elicited antibodies, and the protective efficacy elicited in mice immunized with the vaccine candidates. We observed a significant correlation between the level of in vitro virus-like particle secretion, the elicited antibody response, and the protective efficacy of the vaccines containing the DNA of the different DENV genotypes in immunized mice. However, higher total IgG antibody levels did not always translate into higher Nt antibodies against homologous and heterologous viruses. We also found that, in contrast to previous reports, more than 50% of total IgG targeted ectodomain III (EDIII) of the E protein, and a substantial fraction of this population was interdomain highly neutralizing flavivirus subgroup-cross-reactive antibodies, such as monoclonal antibody 1B7-5. In addition, the lack of a critical epitope(s) in the Sylvatic genotype virus recognized by interdomain antibodies could be the major cause of the poor protection of mice vaccinated with the Asian 1 genotype vaccine (pVD2-Asian 1) from lethal challenge with virus of the Sylvatic genotype. In conclusion, although the pVD2-Asian 1 vaccine was immunogenic, elicited sufficient titers of Nt antibodies against all DENV-2 genotypes, and provided 100% protection against challenge with virus of the homologous Asian 1 genotype and virus of the heterologous Cosmopolitan genotype, it is critical to monitor the potential emergence of Sylvatic genotype viruses, since vaccine candidates under development may not protect vaccinated humans from these viruses

    Infectious Alopecia in a Dog Breeder After Renal Transplantation

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    Tinea capitis rarely occurs in renal transplant recipients. We report this living-related renal transplant patient receiving cyclosporine-based therapy who initially presented with severe exfoliation of the scalp with yellowish-white scales and marked hair loss. The lesions extended to the frontal area and both cheeks, resulting in several skin ulcers with perifocal erythematous inflammatory changes, and palpable cervical lymph nodes. A biopsy of a skin lesion revealed fungal infection and culture yielded Microsporum canis. The patient mentioned an outbreak of ringworm in her breeding dogs during this period. After adequate treatment of the patient and her infected animals with griseofulvin and disinfection of the environment, her skin lesions resolved dramatically, with regrowth of hair

    Fuzzy TOPSIS for Multiresponse Quality Problems in Wafer Fabrication Processes

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    The quality characteristics in the wafer fabrication process are diverse, variable, and fuzzy in nature. How to effectively deal with multiresponse quality problems in the wafer fabrication process is a challenging task. In this study, the fuzzy technique for order preference by similarity to an ideal solution (TOPSIS), one of the fuzzy multiattribute decision-analysis (MADA) methods, is proposed to investigate the fuzzy multiresponse quality problem in integrated-circuit (IC) wafer fabrication process. The fuzzy TOPSIS is one of the effective fuzzy MADA methods for dealing with decision-making problems under uncertain environments. First, a fuzzy TOPSIS methodology is developed by considering the ambiguity between quality characteristics. Then, a detailed procedure for the developed fuzzy TOPSIS approach is presented to show how the fuzzy wafer fabrication quality problems can be solved. Real-world data is collected from an IC semiconductor company and the developed fuzzy TOPSIS approach is applied to find an optimal combination of parameters. Results of this study show that the developed approach provides a satisfactory solution to the wafer fabrication multiresponse problem. This developed approach can be also applied to other industries for investigating multiple quality characteristics problems

    High-Frequency Ultrasound Imaging to Evaluate Liver Fibrosis Progression in Rats and Yi Guan Jian Herbal Therapeutic Effects

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    The animals used in liver fibrosis studies must usually be sacrificed. Ultrasound has been demonstrated to have the ability to diagnose hepatic fibrosis and cirrhosis in experimental small-animal models. However, few studies have used high-frequency ultrasound (HFU, 40 MHz) to monitor changes in the rat liver and other hollow organs longitudinally. In this study, liver fibrosis was induced by administering dimethylnitrosamine (DMN) in SD rats, aged 8 weeks, for three consecutive days per week for up to 4 weeks. A Chinese herbal medicine Yi Guan Jian (YGJ) was orally administered (1.8 g/kg daily) to DMN-induced liver fibrosis rats for 2 weeks. Compared with the normal control rats, rats treated with DMN for either 2 weeks or 4 weeks had significantly lower body weights, liver indexes and elevation of hydroxyproline, GOT, and GPT contents. YGJ herbal treatment remarkably prevented rats from DMN-induced liver fibrosis. The HFU scoring results among the normal controls, 2-week DMN-treated rats, 4-week DMN-treated rats, and combined 2-week YGJ therapy with 4-week DMN-treated rats also reached statistical significance. Thus, HFU is an accurate tool for the longitudinal analysis of liver fibrosis progression in small-animal models, and the YGJ may be useful in reversing the development of hepatic fibrosis
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