IL28B genetic variants and gender are associated with spontaneous clearance of hepatitis C virus infection.

Single nucleotide polymorphisms (SNPs) near the IL28B gene have been shown to be associated with response to treatment for chronic hepatitis C and also with spontaneous clearance of hepatitis C virus (HCV) infection. We analysed the association between IL28B genetic variants and spontaneous clearance of HCV infection in 376 HCV-infected Chinese paid plasma donors. Genotyping of eight SNPs near the IL28B region was performed by the iPLEX system (MassARRAY(®) SNP Genotyping; Sequenom) in all donors, and sequencing was performed on all 80 donors who cleared HCV and on 160 of 296 donors who did not clear HCV to validate the genotypes. Eighty (21.3%) donors spontaneously cleared HCV. Four SNPs were significantly associated with spontaneous HCV clearance: rs8099917 TT (vs GT), rs8105790 TT (vs CT), rs12980275 AA (vs AG) and rs10853728 CC (vs CG or GG) with OR (95% CI) 15.27 (2.07-112.50), 14.88 (2.02-109.72), 7.92 (1.88-33.32) and 2.32 (1.22-4.42) respectively. No association between the other four IL28B SNPs including rs12979860 and spontaneous HCV clearance was found. Women had a higher rate of spontaneous HCV clearance than men [56/213 (26.3%) vs 24/163 (14.6%), P = 0.007], and this was true even after stratification for IL28B genotypes with OR of 1.9-2.2 among those with favourable genotypes. Our results confirmed that IL28B polymorphism is associated with spontaneous clearance of HCV in Chinese subjects, but the SNPs that predict HCV clearance in Chinese subjects were different from those reported in Caucasians. Women were more likely to clear HCV infection regardless of IL28B genotypes.

Knock-down of USP22 by small interfering RNA interference inhibits HepG2 cell proliferation and induces cell cycle arrest.

The Ubiquitin--specific protease 22 (USP22) is a new putative cancer stem cell marker, which plays a significant role in tumorigenesis and cell--cycle progression. However, little is known about the impact of USP22 knock--down on the growth of human hepatoma cell lines. In this study, elevated expression of USP22 was observed in the human HepG2 hepatic cancer cell line compared to the normal human hepatocyte Chang liver cell line. Subsequently, we used siRNA specifically suppressing expression of USP22 and observed that the knock--down of USP22 could effectively induce cell cycle arrest and inhibit HepG2 cell proliferation. Furthermore, our results showed that USP22 deletion caused down--regulation of cyclin D2 expression and up--regulation of p15 and p21 expression. Collectively, Our findings indicate that USP22 may be responsible for HepG2 cell growth and USP22 regulates the cell cycle via the c--Myc/cyclin D2 pathway and down--regulating p15 and p21 expression in HepG2 cell.

Identification of aberrant promoter methylation of EDNRB gene in esophageal squamous cell carcinoma.

Epigenetic silencing of tumor suppressor genes is a major contributor to neoplastic transformation and is an area of intense research. The purpose of the present study was to identify the epigenetic changes in esophageal squamous cell carcinoma (ESCC). Methylation-sensitive arbitrarily primed polymerase chain reaction analysis was used on 21 matched ESCC tumors and adjacent normal tissues. Through this screen we identified a frequently methylated fragment that showed a high homology to the 5' CpG island of endothelin receptor type B (EDNRB) gene. The methylation status of the EDNRB gene was then detected by bisulfite sequencing and the levels of EDNRB mRNA were detected by quantitative real-time polymerase chain reaction (PCR). In addition, the effects of a methylation inhibitor 5-aza-2'-deoxycytidine on EDNRB mRNA expression was determined in cells of an ESCC cell lines. Hypermethylation of the 5' CpG island of EDNRB was found in 5 out of 21 (23.8%) primary tumors. Real-time PCR analysis demonstrated that EDNRB mRNA expression was significantly reduced in tumors showing high promoter methylation compared with paired normal tissues, whereas there is no significant difference between other paired samples. In addition, treatment of ESCC cell line with 5-aza-2'-deoxycytidine led to reexpression of the EDNRB transcript, which is correlated with the reversal of the methylation status of EDNRB promoter. In conclusion, promoter hypermethylation of EDNRB gene, which is associated with the loss of EDNRB mRNA expression, may play a role in the development of ESCC.

Aberrant promoter methylation of the TPEF gene in esophageal squamous cell carcinoma.

Aberrant methylation of tumor suppressor genes plays an important role in the development of esophageal squamous cell carcinoma (ESCC). The purpose of the present study was to identify the epigenetic changes in ESCC. Methylation-sensitive arbitrarily primed polymerase chain reaction (MS AP-PCR) analysis was used on 22 matched ESCC tumors and adjacent normal tissues. Through this screen we identified a frequently methylated fragment that showed a high homology to the 5'-CpG island of the gene encoding a transmembrane protein containing epidermal growth factor and follistatin domains (TPEF). The methylation status of the TPEF gene was then detected by bisulfite sequencing and the levels of TPEF mRNA were detected by RT-PCR. In addition, the effects of a methylation inhibitor 5-aza-2'-deoxycytidine on TPEF mRNA expression was determined in cells of ESCC cell lines. Hypermethylation of the 5'-CpG island of TPEF was found in 12 of 22 (54.5%) primary tumors. Reverse transcription PCR analysis demonstrated that TPEF mRNA expression was significantly lower in tumors than in adjacent normal tissues, which is associated with promoter hypermethylation. In addition, treatment of ESCC cell lines with 5-aza-2'-deoxycytidine led to re-expression of the TPEF transcript. In conclusion, we observed promoter of TPEF gene is frequently hpermethylated, and is associated with the loss of TPEF mRNA expression in ESCC samples. Promoter hypermethylation of TPEF gene may play a role in the development of ESCC.

A prospective study of vertical transmission of hepatitis C virus.

AIM: To prospectively study the mechanism of mother to infant transmission of hepatitis C virus (HCV). METHODS: Using a nested PCR for detection of HCV RNA and the second generation ELISA for detection of anti-HCV, 13 pregnant women who suffered from post transfusion hepatitis C (PT-HCV) and their 15 babies were studied to evaluate mother to infant transmission of HCV. RESULTS: The total infection rate of HCV was 86.7% in the babies, including one case of clinical HCV (7.7%), three subclinical cases of HCV (23.1%), and nine inapparent cases of HCV (69.2%). The positive rates of anti-HCV and HCV RNA declined with the age of the babies, to 7.7% for anti-HCV and 15.4% for HCV RNA at the age of three years. CONCLUSION: Babies born to mothers infected with HCV were vertically infected with HCV at a high rate, but the consequences were not serious. Four fetuses born, born through induced labor to mothers positive for anti-HCV and HCV, were all infected by HCV, suggesting that the mother to infant transmission of HCV mainly occurred in the uterus.

Epidemiologic investigation on an outbreak of hepatitis C.

An outbreak of hepatitis in plasma donors occurred in a village of Hebei Province in the period of September to October 1985. The morbidity rate was 40.0% (26/65) in the plasma donors, which was significantly higher than that in whole blood donors (1/88) and in persons who were not blood donors (1/400). One to one paired survey was carried out, and the incidence was 46.4% (26/56) in the plasma donors, while there were no such outbreak in the control group. The distribution of cases showed positive correlation with the number of plasma donors from the production brigade. No secondary infection was found in their families. The peak of outbreak was about 2 months later than the peak of plasma donation. 26 cases of hepatitis in plasma donors all showed negative results for anti-HAV IgM, HBsAg, anti-HBC IgM, anti-CMV IgM and anti-EBV IgM. Sera of 25 cases were selected and sent to CDC, USA to confirm with Chiron C100 reagent. 24 cases were anti-HCV positive. This outbreak of hepatitis was demonstrated to be related to cross contamination during plasma donation.

A serological study of hepatitis C infection in plasmapheresis donors.

An epidemic of parenterally transmitted non-A, non-B hepatitis (PT-NANBH) occurred in plasmapheresis donors in Guan County, Hebei Province, China, in 1985. PT-NANBH was diagnosed by epidemiological studies and serological exclusion of HAV, HBV, CMV and EBV infections. Recently, 163 sera samples of 108 patients with PT-NANBH and 65 sera samples of 49 cases with elevated alanine aminotransferase (ALT) levels collected during the epidemic were tested by anti-HCV EIA (Chiron C100). The positive rates of anti-HCV in these two groups were 89.8% (97/108) and 93.9% (46/49), averaging 90.8%. The figures increased with the course of illness and persistance of ALT elevation, i.e., 17.6% and 55.6% within 1 month, 88.9% and 87.5% at 6 months and 100% and 100% after 2 years. Five patients with PT-NANBH and 1 with elevated ALT levels were followed up for 3 to 4 years. We demonstrated that anti-HCV remained positive after the disease had resolved and ALT levels had normalized.

An animal model to study erythrocyte senescence with a narrow time window of erythrocyte production: alterations in osmotic fragility and deformability of erythrocytes during their life span.

Using the model in which the entire RBC population was nearly synchronously produced following the induction of spherocytic anemia in the rabbit with antibody serum, we determined the changes of RBC osmotic fragility and deformability with aging. The results showed that the osmotic fragility increased with the RBC aging process in a nonlinear manner, being much more profound in the later part of the RBC life span. The RBC deformation index (DI) was measured by an ektacytometry. It is found that the DI decreased with RBC aging in a nonlinear fashion, with increasingly greater changes in the later part of the RBC life span. The alterations of RBC mechanical properties with aging may be attributable to a number of factors, including changes of RBC size and shape, and the viscoelasticity of the cytoplasm and membrane.

Changes of biophysical behavior of k562 cells for p16 gene transfer.

p16 gene was transferred into human erythroleukemia cell line K562 that had been subjected to p16 deletion. The changes of biophysical behavior of K562 cells after gene transfer were studied with the micropipette technique. The micropipette data were analyzed with a standard solid viscoelastic model. In comparison to untransfected control K562 cells and the cells transfected with an empty vector, the p16-transfected K562 cells showed an increase in the elastic element K(1), which is inversely proportional to the maximum deformation over a long period of time, whereas the viscous element mu and the other elastic element K(2) showed no significant difference. The results indicate that K562 cells became more rigid after p16 transfer. The p16-transfected K562 cells also had a higher surface charge density. This study contributes to our knowledge about the suppression effect of p16 gene on tumor cell migration and about its use in gene therapy.

Butterfly interconnection implementation for an n-bit parallel ripple carry full adder.

Free-space optical interconnections are important both in massive digital optical computing and in communication systems. The optical butterfly interconnection has many advantages over other interconnections in implementing various basic logic functions such as addition, subtraction, multiplication. This paper starts with the conventional Karnaugh maps and Boolean algebra to implement a parallel n-bit ripple carry full adder by the use of multilayer butterfly interconnection networks. Then we describe in detail the design and architecture of the full adder and provide accurate interconnection networks and the structures or patterns of key devices such as the masks to implement AND and OR operations in this calculation. Finally, we discuss development of the interconnection in implementing logic operations.

[A comparative study of primary and re-infection with hepatitis C].

A nested polymerase chain reaction (PCR) was used to assess HCV re-infection and primary infection. In 10 hepatitis cases defined as primary infection, 9 showed clinical hepatitis, and 1 case was subclinical; the interval between transfusion and elevation of alanine aminotransferase (ALT) levels was 15-60 (37.9 + 13.9) days. 10/10 and 7/10 were persistently positive for anti-HCV and HCV RNA for more than 1 year respectively. Similarly, in 5 cases defined as re-infection, 4/5 showed clinical hepatitis, the interval between transfusion and elevation of ALT was 30-46 (34.8 +/- 6.4) days, and 5/5 and 3/5 were persistently positive for anti-HCV and HCV RNA for more than 1 year respectively. All 5 re-infected recipients showed abnormal ALT. In conclusion, there was no significant difference (P > 0.05) in the aspect of the clinical figure, ALT abnormality, the duration of anti-HCV and HCV RNA etc. Resulting from primary or re-infection with HCV, suggesting that primary infection fail to induce a Protective immune response.

Combination of free-space and guided-wave optical interconnects for angularly multiplexed multiwavelength holographic memory.

We propose and test experimentally a new scheme to implement spatially multiplexed multiwavelength holographic memory. An electro-optically modulated phase grating array on LiNbO(3) substrate is used as a guided-wave interconnect to activate the reconfigurable reference beam. The object beam is provided by free-space interconnect. An electro-optic modulation efficiency of 18 +/- 2.5% is achieved with an applied voltage of 100 V. The reference beams with different diffraction angles can implement the angle-multiplexing holographic recording. We believe this is the first report of the implementation of guided-wave electro-optic interconnect together with free-space interconnect in holographic memory applications.

Optoelectronic butterfly interconnection architecture of modified signed-digit arithmetic systems: fully parallel adder and subtracter.

The carry-free property of modified signed-digit addition is discussed, and a space-position-logic-encoding scheme is proposed, which not only makes best use of the convenience of binary (0, 1) logic operation but is also suitable for the trinary (1, 0, 1-) property of modified signed-digit digits. Based on the spaceposition-logic-encoding scheme, a fully parallel modified signed-digit adder and subtracter is built by use of optoelectronic switch modules and butterfly interconnections; thus an effective combination of a parallel algorithm and a parallel architecture is implemented. The effectiveness of this architecture is verified by both simulation and experimental results.

Butterfly interconnection networks and their applications in information processing and optical computing: applications in fast-Fourier-transform-based opticalinformation processing.

As modern optical information processing has developed, research on massive and parallel rapid computing and processing has attracted more attention. In this paper, butterfly networks and a variety of types of optical information processing are studied and discussed. For a basis, one- and twodimensional butterfly interconnection networks are studied in constructions, and the relationship and the transformation between them are provided. Algorithms for both the one- and two-dimensional fast Fourier transforms are analyzed, one- and two-dimensional butterfly networks for implementing the algorithms are built, and computer-simulation results are attained. Finally, an underlying optical network system is suggested and studied in respect to its architecture and advantages; it is a new optical butterfly network hardware system consisting of two-dimensional binary phase diffraction gratings, which perform a variety of types of fast-Fourier-transform-based optical information processing.

A dynamic study of viraemia in chronic hepatitis C infection.

The dynamics of alanine aminotransferase (ALT), anti-hepatitis C virus and hepatitis C virus (HCV) RNA in six cases with chronic HCV infection were studied for 3-7 years. Two of the six cases showed continued elevation of ALT, and three showed intermittent elevation. All cases were persistently positive for anti-HCV after initial seroconversion. Five of the six cases were persistently positive for HCV RNA detected by nested polymerase chain reaction, and one was positive intermittently. Thus hepatitis C virus replicates continually in a majority of patients with chronic hepatitis C, although some cases may show intermittent replication, and replication of hepatitis C virus does not always correlate with elevated ALT.

A study of primary- and re-infection with hepatitis C virus in blood transfusion recipients.

A nested polymerase chain reaction was used to assess viraemia in blood transfusion recipients with no serological evidence of hepatitis C virus (HCV) infection (naive recipients) and in recipients with prior or existing HCV infection (infected recipients), who were transfused with HCV-positive blood. In 10 hepatitis cases in naive recipients, defined as primary infection, nine showed clinical hepatitis, and one was sub-clinical; the time between transfusion and elevation of alanine aminotransferase (ALT) levels was 15-60 days (37.9 +/- 13.9). All 10 naive recipients showed abnormal ALT, and 10/10 and 7/10 were persistently positive for anti-HCV and HCV-RNA, respectively, for more than 1 year. Similarly, in five cases in previously infected recipients, defined as re-infection, 4/5 showed clinical hepatitis, the time to elevation of ALT was 30-46 days (34.8 +/- 6.4), and 5/5 and 3/5 were persistently positive for anti-HCV and HCV-RNA, respectively, for more than 1 year. All five infected recipients showed abnormal ALT. In conclusion, there was no significant difference (P = 0.05) in the frequency of the markers of infection resulting from primary or re-infection with HCV, suggesting that primary infection fails to induce a protective immune response.