RESUMO
Microwave plasma was generated in a glass bottle containing 2-3 Torr of oxygen for plasma treatment of a polymer surface. A "kitchen microwave oven" and a dedicated microwave digestion oven were used as the power source. Poly(dimethylsiloxane)(PDMS) slabs treated by a 30 W plasma for 30-60 s sealed irreversibly to form microfluidic devices that can sustain solution flow of an applied pressure of 42 psi without leaking. Experimental set up and conditions for the production of a homogeneous plasma to activate the PDMS surface for irreversible sealing are described in detail. The surface of a microwave plasma-treated PDMS slab was characterized using atomic force microscopy (AFM) and attenuated total reflection-Fourier Transform infrared spectroscopy (ATR-FTIR). The plasma-treated surface bears silica characteristics.
Assuntos
Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodos , Polímeros/química , Dimetilpolisiloxanos , Microfluídica , Microscopia de Força Atômica , Micro-Ondas , Pressão , Silício , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Fatores de TempoRESUMO
Hepatitis B virus (HBV) can be detected in saliva of carriers and epidemiological studies suggest human bite as a possible route of transmission. We report a case of acute hepatitis B that developed after an individual with learning difficulty was bitten by a fellow resident in a sheltered accommodation. The attacker was found to be a chronic carrier of HBV and virus was present in his saliva. The HBV in both men had identical genotype and sequence. Future studies are warranted to investigate the role of saliva as a vehicle of HBV transmission in the community.
Assuntos
Mordeduras Humanas , Vírus da Hepatite B/classificação , Vírus da Hepatite B/isolamento & purificação , Hepatite B/transmissão , Saliva/virologia , Adulto , Sequência de Bases , Genoma Viral , Hepatite B/virologia , Vírus da Hepatite B/genética , Humanos , Masculino , Dados de Sequência Molecular , Análise de Sequência de DNARESUMO
BACKGROUND & AIMS: This study aimed to determine whether intrahepatic hepatitis B virus (HBV) covalently closed circular (ccc) DNA and total HBV DNA levels at the end of therapy would predict sustained response to therapy. METHODS: Hepatitis B e antigen (HBeAg)-positive chronic hepatitis B patients receiving either lamivudine monotherapy or combination of peginterferon and lamivudine had liver biopsy at the end of 1 year therapy and were followed for 52 more weeks after cessation of therapy. Serum HBV DNA, intrahepatic HBV ccc DNA, and total HBV DNA levels were determined. RESULTS: Forty-seven patients, including 34 males and 13 females, were studied. Twenty-seven patients received combination therapy, and 20 patients received lamivudine monotherapy. Twenty-nine patients had end-of-treatment virologic response, and 15 patients had sustained response 52 weeks after therapy. At the end of treatment, log serum HBV DNA levels correlated well with log intrahepatic HBV cccDNA and log intrahepatic total HBV DNA levels. Log intrahepatic cccDNA and log intrahepatic total DNA levels were significantly lower among patients with sustained virologic response. The adjusted odds ratio for log cccDNA was 5.3 (95% CI: 1.5-18.2, P = .009) and, for log intrahepatic HBV DNA, was 4.4 (95% CI: 1.3-14.7, P = .015) to predict sustained virologic response. Using log cccDNA at -0.80 copies/genome equivalent as cutoff, the sensitivity, specificity, and positive and negative predictive values and accuracy of predicting sustained virologic response were 73%, 78%, 56%, 86%, and 77% respectively. CONCLUSIONS: Intrahepatic HBV cccDNA and intrahepatic total HBV DNA levels at the end of therapy are superior to serum HBV DNA as surrogates of sustained virologic response.