Ultrasonics Sonochemistry Assisted Preparation of Polysiloxane Main‐Chain Liquid‐Crystalline Elastomers

For the first time, an ultrasonics sonochemistry method is developed to promote the one‐pot hydrosilylation polyaddition polymerization and crosslinking reaction in the preparation of polysiloxane main‐chain liquid‐crystalline elastomers (MC‐LCEs). Due to the extraordinary effect of acoustic cavitation, the polyaddition polymerization and crosslinking reaction can be successfully carried out in an ordinary laboratory ultrasonic cleaner at room temperature, and generates the LCE matrix network in about 30 min. The prepared MC‐LCEs demonstrate good quality, good properties, and stimuli‐actuation performances. Compared to the traditional thermal processing methods for preparing polysiloxane MC‐LCEs, this method exhibits superior properties rapidly, with high convenience and efficiency, and can be a path for batch fabrication at low cost. The work also demonstrates that the ultrasonics sonochemistry method is effective in generating linear main‐chain liquid crystal polymers through hydrosilylation polyaddition and polysiloxane side‐chain LCE matrix through hydrosilylation crosslinking reaction, thus confirming the high availability of ultrasonics sonochemistry in the processes of hydrosilylation polymerization, crosslinking reactions, or synchronous polymerization and crosslinking reactions.     

Use of enzyme-linked immunosorbent assays with chimeric fusion proteins to titrate antibodies against Epstein-Barr virus nuclear antigen 1.

Two new enzyme-linked immunosorbent assays (ELISAs) with chimeric fusion polypeptides for the detection of human antibodies specific to Epstein-Barr virus nuclear antigen 1 (EBNA-1) are described. One is an indirect ELISA with affinity-purified beta-galactosidase-EBNA-1 fusion protein as the antigen. The other is a "sandwich" assay based on the use of anti-beta-galactosidase antibody to capture beta-galactosidase-EBNA-1 fusion proteins in bacterial extracts. A good correlation was shown between antibody titers determined by the ELISA with the EBNA-1 fusion proteins and those determined by a conventional anticomplement immunofluorescence test which is being widely performed with Raji cells for the purpose of research and clinical diagnosis. The advantage of the ELISAs for seroepidemiologic studies on Epstein-Barr virus was demonstrated by sensitive detection of marginal immunoglobulin G antibody to the EBNA-1 domain in serum samples from patients with infectious mononucleosis.     

Differentiation of Campylobacter jejuni Serotype O19 Strains from Non-O19 Strains by PCR

Guillain-Barré syndrome (GBS), a neurologic disease characterized by acute paralysis, is frequently preceded by Campylobacter jejuni infection. Serotype O19 strains are overrepresented among GBS-associated C. jejuni isolates. We previously showed that all O19 strains tested were closely related to one another by randomly amplified polymorphic DNA (RAPD) and restriction fragment length polymorphism analyses. RAPD analysis demonstrated a 1.4-kb band in all O19 strains tested but in no non-O19 strains. We cloned this O19-specific band; nucleotide sequence analysis revealed a truncated open reading frame with significant homology to DNA gyrase subunit B (gyrB) of Helicobacter pylori. PCR using the random primer and a primer specific for gyrB showed that in non-O19 strains, the random primer did not recognize the downstream gyrB binding site. The regions flanking each of the random primer binding sites were amplified by degenerate PCR for further sequencing. Although the random primer had several mismatches with the downstream gyrB binding site, a single nucleotide polymorphism 6 bp upstream from the 3′ terminus was found to distinguish O19 and non-O19 strains. PCR using 3′-mismatched primers based on this polymorphism was designed to differentiate O19 strains from non-O19 strains. When a total of 42 (18 O19 and 24 non-O19) strains from five different countries were examined, O19 strains were distinguishable from non-O19 strains in each case. This PCR method should permit identification of O19 C. jejuni strains.     

Minimum requirement of artificial noise level for using noise-assisted correlation algorithm to suppress artifacts in ultrasonic Nakagami images

The Nakagami image is a complementary imaging mode for pulse-echo ultrasound B-scan to characterize tissues. White noise in anechoic areas induces artifacts in the Nakagami image. Recently, we proposed a noise-assisted correlation algorithm (NCA) for suppressing the Nakagami artifact. In the NCA, artificial white noise is intentionally added twice to backscattered signals to produce two noisy data, which are used to establish a correlation profile for rejecting noise. This study explored the effects of artificial noise level on the NCA to suppress the artifact of the Nakagami image. Simulations were conducted to produce B-mode images of anechoic regions under signal-to-noise ratios (SNRs) of 20, 10 and 5 dB. Various artificial noise levels ranging from 0.1- to 1-fold of the intrinsic noise amplitude were used in the NCA for constructing the Nakagami images. Phantom experiments were conducted to validate the performance of using the optimal artificial noise level suggested by the simulation results to suppress the Nakagami artifacts by the NCA. The simulation results indicated that the artifacts of the Nakagami image in the anechoic regions can be gradually suppressed by increasing the artificial noise level used in the NCA to improve the image contrast-to-noise ratio (CNR). The CNR of the Nakagami image reached 20 dB when the artificial noise level was 0.7-fold of the intrinsic noise amplitude. This criterion was demonstrated by the phantom results to provide the NCA with an excellent ability to obtain artifact-free Nakagami images.     

In vitro and in vivo antioxidant activity of the ethanolic extract from Meconopsis quintuplinervia

Aims of the study

Meconopsis quintuplinervia, a medicinal herb endemic to the Tibetan region, is used to treat hepatitis. The aim of this study is to evaluate the antioxidant potential of the ethanolic extract of this herb using different assays.

Materials and methods

The antioxidant capacity of Meconopsis quintuplinervia was investigated using various established in vitro systems. An in vivo study of carbon tetrachloride (CCl₄)-induced antioxidant activity in mice was also conducted by examining the levels of malondialdehyde (MDA) and the activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH).

Results

The extract showed strong in vitro antioxidant ability. In the in vivo study, CCl₄-induced oxidative stress caused significant decreases in the SOD, CAT, and GSH levels and a significant increase in the MDA level, most of which were significantly reversed (except for SOD in the liver.) by treatment with the extract and standard Vitamin E.

Conclusion

This study clearly indicates that the ethanolic extract of Meconopsis quintuplinervia is a valuable source of natural antioxidants. These findings provide scientific support for the traditional use of this herb as a Tibetan medicine for liver diseases.     

Electrocautery therapy combined with oral steroid administration for refractory corrosive esophageal stenosis prevents restenosis

A 61-year-old female with refractory corrosive esophageal stenosis repeatedly underwent endoscopic balloon dilation at another hospital; however, no improvements were observed in the esophageal stenosis. Consequently, she had been on a liquid diet for the previous three years. She was admitted to our department for further treatment. A radial incision was made, by use of the SB knife Jr, for a pinhole-like stenosis in a short segment 39 cm from the incisor, and dilation was safely performed by use of a CRE balloon dilator. Subsequently, prednisolone was orally administered to prevent re-stenosis. This was followed by a favorable clinical course.     

Cellular localization of the target structures recognized by the anti-Jo-1 antibody: immunofluorescence studies on cultured human myoblasts

Antibodies to Jo-1 (alpha Jo-1) are most characteristically detected in patients with the idiopathic inflammatory muscle disease polymyositis (PM). The Jo-1 antigen has previously been identified as histidyl-tRNA synthetase (HRS). In order to clarify the cellular localization of the antigenic targets recognized by the alpha Jo-1 antibody, immunofluorescence (IF) studies were performed with cultured human myoblasts. Incubation with alpha Jo-1 positive sera demonstrated granular cytoplasmic as well as nuclear staining, but only the cytoplasmic fluorescence was specifically inhibited by preabsorbing the sera with recombinant histidyl-tRNA synthetase (rHRS). A polyclonal rabbit anti-rHRS sera demonstrated granular cytoplasmic IF which was also specifically inhibited by preincubation with rHRS protein. Alpha Jo-1 negative healthy control or patient sera demonstrated nonspecific low intensity staining. 35S methionine biosynthetically labelled myoblast cell extracts immunoprecipitated with alpha Jo-1 positive sera and analyzed by SDS-PAGE revealed a specific band of the same molecular weight as the rHRS antigen. Our studies demonstrate that alpha Jo-1 specifically binds to antigen in the cytoplasm of cultured myoblasts. Alpha Jo-1 has been shown to inhibit HRS activity in vitro. Given the importance of aminoacyl tRNA synthetases such as HRS to intracellular protein assembly, intracytoplasmic binding and enzyme inhibition in vivo may potentially contribute to the pathogenesis of autoimmune muscle damage in PM.     

Hepatitis C and hospital outcomes in patients admitted with alcohol-related problems

BACKGROUND/AIMS: Alcohol is known to act synergistically with chronic hepatitis C virus (HCV) infection to cause liver disease; however, their combined effect on outcomes in acutely hospitalized patients is less clear. We examined the impact of HCV infection on hospital mortality and length of stay among hospitalized patients with alcohol abuse problems. METHODS: We retrospectively identified 6354 admissions to an urban, public hospital between July 1996 and January 2002 with discharge diagnoses related to alcohol dependence or abuse. Hepatitis C diagnosis and other information were extracted from a clinical database and tested for associations with death and length of hospital stay using multivariable regression techniques. RESULTS: The prevalence of diagnosed HCV infection in this sample of patients with alcohol abuse was 15%. Patients with HCV were about twice as likely to die during hospital admission (4.4 vs. 2.4%; P-value < 0.01), and there appeared to be a trend toward increased mortality even after adjustment for demographics, medical service, homelessness and comorbidities (fully adjusted OR 1.41; 95% CI: 0.97-2.04). Length of stay was significantly longer for patients with HCV (19% longer; 95% CI: 12-27% after adjustment) than those without. CONCLUSIONS: Patients admitted to the hospital with alcohol-related diagnoses have longer hospital stays and are more likely to die in hospital if they have a diagnosis of HCV.