A Multi-Threshold Sampling Method for TOF PET Signal Processing

As an approach to realizing all-digital data acquisition for positron emission tomography (PET), we have previously proposed and studied a multi-threshold sampling method to generate samples of a PET event waveform with respect to a few user-defined amplitudes. In this sampling scheme, one can extract both the energy and timing information for an event. In this paper, we report our prototype implementation of this sampling method and the performance results obtained with this prototype. The prototype consists of two multi-threshold discriminator boards and a time-to-digital converter (TDC) board. Each of the multi-threshold discriminator boards takes one input and provides up to 8 threshold levels, which can be defined by users, for sampling the input signal. The TDC board employs the CERN HPTDC chip that determines the digitized times of the leading and falling edges of the discriminator output pulses. We connect our prototype electronics to the outputs of two Hamamatsu R9800 photomultiplier tubes (PMTs) that are individually coupled to a 6.25×6.25×25mm(3) LSO crystal. By analyzing waveform samples generated by using four thresholds, we obtain a coincidence timing resolution of about 340 ps and an ∼18% energy resolution at 511 keV. We are also able to estimate the decay-time constant from the resulting samples and obtain a mean value of 44ns with an ∼9 ns FWHM. In comparison, using digitized waveforms obtained at a 20 GSps sampling rate for the same LSO/PMT modules we obtain ∼300 ps coincidence timing resolution, ∼14% energy resolution at 511 keV, and ∼5 ns FWHM for the estimated decay-time constant. Details of the results on the timing and energy resolutions by using the multi-threshold method indicate that it is a promising approach for implementing digital PET data acquisition.

Anticaries effect of compounds extracted from Galla chinensis in a multispecies biofilm model

INTRODUCTION

Galla Chinensis is a leaf gall known to have some antibacterial effects. Using an in vitro biofilm model of dental plaque, the present study aimed to evaluate the anticaries effects of Galla Chinensis and its chemical fractions.

METHODS

A four-organism bacterial consortium (Streptococcus sanguis, Streptococcus mutans, Actinomyces naeslundii, Lactobacillus rhamnosus) was grown on hydroxyapatite (HA) discs, bovine enamel blocks, and glass surfaces in a continuous culture system and exposed to repeated solution pulses. Galla Chinensis extracts, sucrose solutions, and sodium fluoride solutions were pulsed into different flow cells. The pH value of the planktonic phase in each flow cell was recorded and the bacteria colonizing the biofilm on the HA discs were counted. Enamel blocks were observed using a polarized microscope and lesion depth was evaluated. The biofilm morphology was examined with a fluorescence microscope and the images captured were analyzed on an image analysis system.

RESULTS

When Galla Chinensis extract, its chemical fraction, or fluoride was added to the sucrose solution, the planktonic phase pH remained higher than that in the sucrose alone. A lower level of colonization on the HA surface was also observed in the groups to which Galla Chinensis and fluoride were added compared with the control sucrose group, and this was reflected in both the total viable count and the biofilm imaging, which showed fewer cariogenic bacteria and a less compact biofilm, respectively. Enamel demineralization in both the fluoride group and the Galla Chinensis group was significantly less than that in the sucrose group.

CONCLUSIONS

Galla Chinensis and fluoride may inhibit the cariogenicity of the oral biofilm. Galla Chinensis appears to be a promising source of new agents that may prevent dental caries.

Experimental demonstration of isotropic negative permeability in a three-dimensional dielectric composite

Isotropic negative permeability resulting from Mie resonance is demonstrated in a three-dimensional (3D) dielectric composite consisting of an array of dielectric cubes. A strong subwavelength magnetic resonance, corresponding to the first Mie resonance, was excited in dielectric cubes by electromagnetic wave. Negative permeability is verified in the magnetic resonance area via microwave measurement and the dispersion properties. The resonance relies on the size and permittivity of the cubes. It is promising for construction of novel isotropic 3D left-handed materials with a simple structure.

Leptin plays a role in ruptured human brain arteriovenous malformations

INTRODUCTION

Intracerebral hemorrhage (ICH) is one of the most common clinical manifestations of human brain arteriovenous malformation (BAVM). However, the hemorrhagic mechanism of BAVM is still unclear. Leptin, first discovered in obesity research, has not been systematically studied in BAVM and ICH. We investigated expression and effect of leptin on human BAVM.

METHODS

Specimens were obtained from 6 BAVM patients, who had been divided into either hemorrhagic or non-hemorrhagic groups. Leptin, leptin receptor, and signal transducers and activators of transcription-3 (STAT3) were analyzed by different methods, such as gene chips, reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, and Western blot. Perinidal brain tissue around each BAVM served as control.

RESULTS

Gene chips and RT-PCR found transcriptional leptin raised at least 2 levels in hemorrhagic BAVM. Immunohistochemical slices also showed higher expression of leptin, leptin receptor, and STAT3 on nidus part of hemorrhagic BAVM than non-hemorrhagic ones. On Western blot analysis, hemorrhagic BAVMs had higher levels of leptin (p < 0.01).

CONCLUSIONS

The transcriptional and translational levels of leptin, leptin receptor, and STAT3 were higher in hemorrhagic BAVM, suggesting that leptin may play an important role in the hemorrhagic mechanism of BAVM.

Glycogen phosphorylase inhibitors: a free energy perturbation analysis of glucopyranose spirohydantoin analogues

GP catalyzes the phosphorylation of glycogen to Glc-1-P. Because of its fundamental role in the metabolism of glycogen, GP has been the target for a systematic structure-assisted design of inhibitory compounds, which could be of value in the therapeutic treatment of type 2 diabetes mellitus. The most potent catalytic-site inhibitor of GP identified to date is spirohydantoin of glucopyranose (hydan). In this work, we employ MD free energy simulations to calculate the relative binding affinities for GP of hydan and two spirohydantoin analogues, methyl-hydan and n-hydan, in which a hydrogen atom is replaced by a methyl- or amino group, respectively. The results are compared with the experimental relative affinities of these ligands, estimated by kinetic measurements of the ligand inhibition constants. The calculated binding affinity for methyl-hydan (relative to hydan) is 3.75 +/- 1.4 kcal/mol, in excellent agreement with the experimental value (3.6 +/- 0.2 kcal/mol). For n-hydan, the calculated value is 1.0 +/- 1.1 kcal/mol, somewhat smaller than the experimental result (2.3 +/- 0.1 kcal/mol). A free energy decomposition analysis shows that hydan makes optimum interactions with protein residues and specific water molecules in the catalytic site. In the other two ligands, structural perturbations of the active site by the additional methyl- or amino group reduce the corresponding binding affinities. The computed binding free energies are sensitive to the preference of a specific water molecule for two well-defined positions in the catalytic site. The behavior of this water is analyzed in detail, and the free energy profile for the translocation of the water between the two positions is evaluated. The results provide insights into the role of water molecules in modulating ligand binding affinities. A comparison of the interactions between a set of ligands and their surrounding groups in X-ray structures is often used in the interpretation of binding free energy differences and in guiding the design of new ligands. For the systems in this work, such an approach fails to estimate the order of relative binding strengths, in contrast to the rigorous free energy treatment.

An in silico ensemble method for lead discovery: decision forest

Recent progress in combinatorial chemistry and parallel synthesis has radically changed the approach to drug discovery in the pharmaceutical industry. At present, thousands of compounds can be made in a short period, creating a need for fast and effective in silico methods to select the most promising lead candidates. Decision forest is a novel pattern recognition method, which combines the results of multiple distinct but comparable decision tree models to reach a consensus prediction. In this article, a decision forest model was developed using a structurally diverse training data set containing 232 compounds whose estrogen receptor binding activity was tested at the U.S. Food and Drug Administration (FDA)'s National Center for Toxicological Research (NCTR). The model was subsequently validated using a test data set of 463 compounds selected from the literature, and then applied to a large data set with 57,145 compounds as a screening example. The results show that the decision forest method is a fast, reliable and effective in silico approach, which could be useful in drug discovery.

Bioinformatics approaches for cross-species liver cancer analysis based on microarray gene expression profiling

Background

The completion of the sequencing of human, mouse and rat genomes and knowledge of cross-species gene homologies enables studies of differential gene expression in animal models. These types of studies have the potential to greatly enhance our understanding of diseases such as liver cancer in humans. Genes co-expressed across multiple species are most likely to have conserved functions. We have used various bioinformatics approaches to examine microarray expression profiles from liver neoplasms that arise in albumin-SV40 transgenic rats to elucidate genes, chromosome aberrations and pathways that might be associated with human liver cancer.

Results

In this study, we first identified 2223 differentially expressed genes by comparing gene expression profiles for two control, two adenoma and two carcinoma samples using an F-test. These genes were subsequently mapped to the rat chromosomes using a novel visualization tool, the Chromosome Plot. Using the same plot, we further mapped the significant genes to orthologous chromosomal locations in human and mouse. Many genes expressed in rat 1q that are amplified in rat liver cancer map to the human chromosomes 10, 11 and 19 and to the mouse chromosomes 7, 17 and 19, which have been implicated in studies of human and mouse liver cancer. Using Comparative Genomics Microarray Analysis (CGMA), we identified regions of potential aberrations in human. Lastly, a pathway analysis was conducted to predict altered human pathways based on statistical analysis and extrapolation from the rat data. All of the identified pathways have been known to be important in the etiology of human liver cancer, including cell cycle control, cell growth and differentiation, apoptosis, transcriptional regulation, and protein metabolism.

Conclusion

The study demonstrates that the hepatic gene expression profiles from the albumin-SV40 transgenic rat model revealed genes, pathways and chromosome alterations consistent with experimental and clinical research in human liver cancer. The bioinformatics tools presented in this paper are essential for cross species extrapolation and mapping of microarray data, its analysis and interpretation.

Bladder transitional cell carcinoma: correlation of contrast enhancement on computed tomography with histological grade and tumour angiogenesis

AIM

To investigate the correlation between the degree of contrast enhancement of bladder cancer in the early enhanced phase of helical computed tomography (CT) and microvessel density (MVD), vascular endothelial growth factor (VEGF) and histological grade.

MATERIALS AND METHODS

Sixty-five patients with transitional cell carcinoma of the bladder were examined by incremental unenhanced CT and helical CT at 40-45 s after initiation of intravenous administration of contrast medium before surgery. The CT density in Hounsfield units of bladder carcinomas were measured in the middle of the maximum diameter section of the cancer lesions on unenhanced and enhanced CT. The degree of contrast enhancement of the tumour was determined as the absolute increase in Hounsfield units. Histological grade, VEGF and MVD were analysed for each cancer. The Pearson and Spearman correlation tests were used to determine the strength of the relationships between CT enhancement and histological grade, VEGF expression and MVD.

RESULTS

Different degrees of enhancement were observed in 91 cancers during the early enhanced phase of helical CT. Mean MVDs and mean CT enhancing values of different histological grade groups were statistically different (p < 0.001). A positive correlation was found in the CT-enhancing value of bladder cancer and MVD (Pearson correlation test; r = 0.938, p < 0.001) and histological grade (Spearman rank correlation; r = 0.734, p < 0.001). VEGF of bladder cancer did not correlate with the change in CT attenuation (Spearman rank correlation; r = 0.087, p = 0.410) and MVD (Spearman rank correlation, r = 0.103, p = 0.330).

CONCLUSION

In bladder cancer, the degree of contrast enhancement during the early enhanced helical CT is correlated with the MVD and histological grade of tumour. It is possible that MVD is the histopathological basis of early contrast enhancement of bladder cancer.

Genital human papillomavirus testing by in situ hybridization in liquid atypical cytologic materials and follow-up biopsies

OBJECTIVE

To describe cases of HPV testing by DNA in situ hybridization performed on atypical cervicovaginal samples collected by a liquidsed method that were negative for HPV DNA on cytology but revealed cervical intraepithelial neoplasia on follow-up biopsies.

STUDY DESIGN

Three hundred ninety-five consecutive SurePath atypical squamous cells of undetermined significance (ASC-US) cytologic samples from asymptomatic, reproductive-age women were tested for human papillomaviruses (HPVs) by the in situ hybridization (ISH) method (Ventana Inform HPV Test, Tucson, Arizona, U.S.A). One hundred (25%) cases underwent follow-up colposcopic biopsy within 3 months of cytology. All the tests (cytology, ISH, histology) were independently evaluated without knowledge of the other tests.

RESULTS

One hundred twenty-two (33%) cytologic samples were positive for HPVs. Of a total of 100 (HPV positive and negative) follow-up biopsies, 55 were positive for cervical intraepithelial neoplasia (CIN). Fourteen cases of biopsy-proven CIN tested negative for all HPV types in the prior cytologic samples. Retesting of the 14 CIN tissues by ISH was negative in 10, positive for HPV in 2 and inconclusive in 2.

CONCLUSION

There is a small but significant (14%) false negative rate with HPV testing by the Ventana ISH method. Clinically suspicious cases should be followed even if an HPV test is negative.

Postnatal development of the reproductive system in the grey short-tailed opossum, Monodelphis domestica

Postnatal phenotypic sex differentiation has been investigated in a laboratory marsupial, Monodelphis domestica, as part of a larger study to resolve apparent discrepancies between eutherian and marsupial mammals. These include the formation of sex-specific structures in marsupials prior to gonadal differentiation and the retention in both sexes of structures which are sex-specific in eutherians. The time-course and nature of differentiation was investigated in 131 specimens ranging in age from the day of birth to 56 days. Patent wolffian ducts extend to the urogenital sinus in both sexes at birth, while müllerian ducts are identified on day 1 and grow in a cranio-caudal direction to reach the urogenital sinus on day 6. The male müllerian duct shows signs of regression at its cranial end on day 10 and throughout its length on day 12; its lumen has completely disappeared by day 15. By this time the epididymis and vas deferens have developed from the wolffian duct; their histological differentiation occurs between days 26 and 56. Prostatic buds are identifiable in tissue surrounding the male urethra on day 14. In the female, the wolffian duct is larger than the müllerian duct until day 14; thereafter the wolffian duct begins to regress at its cranial end, disappearing by day 17, whereas the müllerian duct begins to enlarge, converging with its fellow at the urogenital sinus by day 19. Lateral vaginae, vaginal culs-de-sac, uteri and oviducts have differentiated from the müllerian ducts by day 25. Gonads of both sexes are elongated in shape at birth, attached along the medial aspect of the large mesonephroi in the abdominal cavity. However, from day 3 onwards the testis becomes more rounded than the ovary. Degeneration of the male mesonephros begins about day 10 and is almost completed by day 19; the female mesonephros is still relatively large at day 14 though it too has almost disappeared by day 19. By postnatal day 13 the abdominal phase of testis descent is underway and the inguinal phase begins at day 15. Testes have reached the scrotal sac by day 24 and achieve their final position at the base of the scrotum by day 28. In summary, postnatal reproductive tract development and gonadal descent has been examined in this important biomedical model, where differentiation of the wolffian and müllerian ducts takes place after gonadal differentiation, according to the normal eutherian pattern.

Comparative molecular field analysis (CoMFA) model using a large diverse set of natural, synthetic and environmental chemicals for binding to the androgen receptor

A large number of natural, synthetic and environmental chemicals are capable of disrupting the endocrine systems of experimental animals, wildlife and humans. These so-called endocrine disrupting chemicals (EDCs), some mimic the functions of the endogenous androgens, have become a concern to the public health. Androgens play an important role in many physiological processes, including the development and maintenance of male sexual characteristics. A common mechanism for androgen to produce both normal and adverse effects is binding to the androgen receptor (AR). In this study, we used Comparative Molecular Field Analysis (CoMFA), a three-dimensional quantitative structure-activity relationship (3D-QSAR) technique, to examine AR-ligand binding affinities. A CoMFA model with r2 = 0.902 and q2 = 0.571 was developed using a large training data set containing 146 structurally diverse natural, synthetic, and environmental chemicals with a 10(6)-fold range of relative binding affinity (RBA). By comparing the binding characteristics derived from the CoMFA contour map with these observed in a human AR crystal structure, we found that the steric and electrostatic properties encoded in this training data set are necessary and sufficient to describe the RBA of AR ligands. Finally, the CoMFA model was challenged with an external test data set; the predicted results were close to the actual values with average difference of 0.637 logRBA. This study demonstrates the utility of this CoMFA model for real-world use in predicting the AR binding affinities of structurally diverse chemicals over a wide RBA range.

Regulatory application of SAR/QSAR for priority setting of endocrine disruptors: A perspective

Some seven years have passed since the U.S. legislature mandated the EPA to develop and implement a screening and testing program for chemicals that may disrupt the delicate endocrine system. The envisioned EPA program has evolved to incorporate a tiered scheme of in vitro and in vivo assays, and considered QSAR as a viable method to set testing priorities. At the U.S. FDA's National Center for Toxicological Research (NCTR), the Endocrine Disruptor Knowledge Base Project has developed models to predict estrogen and androgen receptor binding. Our approach rationally integrates various QSAR models into a sequential "Four-Phase" scheme according to the strength of each type of model. In four hierarchical phases, models predict the inactive chemicals that are then eliminated from the pool of chemicals to which increasingly precise but more time-consuming models are subsequently applied. Each phase employs different models selected to work complementarily in representing key activity-determining structure features in order to absolutely minimize the rate of false negatives, an outcome we view as paramount for regulatory use. In this paper, the QSAR models developed at NCTR, and particularly how we integrated these models into the "Four-Phase" system will be discussed for a number of datasets, including 58 000 chemicals identified by the U.S. EPA.

[Expression of WT1 gene mRNA in leukemia]

WT1 gene expression was determined in acute leukemic patients by RT-PCR.

RESULTS

19 patients were found to have positive results among 28 patients, the positive rate is 67.9%, and in 16 ANLL patients, 11 cases got positive results, in 12 ALL patients, 8 cases got positive results. It suggested that WT1 was highly expressed in acute leukemia. It is a new and significant detective marker for monitoring the effect of chemotherapy, predicting the prognosis and in the research of minimal residual disease (MRD).

Purification, crystallization and X-ray analysis of swine vesicular disease virus

Swine vesicular disease virus (SVDV) is the etiological agent of swine vesicular disease, a highly contagious disease in pigs, and is related to coxsackie B virus. Crystalline arrays of SVDV can be observed in the cytoplasm of cells 4.5 h after inoculation to porcine kidney cells (IBRS-2 cells). Crystals of the JX/78 strain of SVDV were obtained from virus in two wells of crystallization conditions and present preliminary X-ray data to 3.6 A resolution.

An integrated "4-phase" approach for setting endocrine disruption screening priorities--phase I and II predictions of estrogen receptor binding affinity

Recent legislation mandates the US Environmental Protection Agency (EPA) to develop a screening and testing program for potential endocrine disrupting chemicals (EDCs), of which xenoestrogens figure prominently. Under the legislation, a large number of chemicals will undergo various in vitro and in vivo assays for their potential estrogenicity, as well as other hormonal activities. There is a crucial need for priority setting before this strategy can be effectively implemented. Here we report an integrated computational approach to priority setting using estrogen receptor (ER) binding as an example. This approach rationally integrates different predictive computational models into a "Four-Phase" scheme so that it can effectively identify potential estrogenic EDCs based on their predicted ER relative binding affinity (RBA). The system has been validated using an in-house ER binding assay dataset for 232 chemicals that was designed to have both broad structural diversity and a wide range of binding affinities. When applied to 58,000 chemicals identified by Walker et al. as candidates for endocrine disruption screening, some 9100 chemicals were predicted to bind to ER. Of these, only 3600 were expected to bind to ER at RBA values up to 100,000-fold less than that of 17beta-estradiol. The method ruled out 83% of the chemicals as non-binders with a very low rate of false negatives. We believe that the same integrated scheme will be equally applicable to endpoints of other endocrine disrupting mechanisms, e.g. androgen receptor binding.

SF/HGF-c-Met autocrine and paracrine promote metastasis of hepatocellular carcinoma

AIM: To explore the role of SF/HGF-Met autocrine and paracrine in met astasis of hepatocellular carcinoma (HCC).

METHODS: SF/HGF and c-met transcri ption and protein expression in HCC were examined by RT-PCR and Western Blot in 4 HCC cell lines, including HepG2, Hep3B, SMMC7721 and MHCC-1, the last cell line had a higher potential of metastasis. sf/hgf cDNA was transfected by the method of Lipofectin into SMMC7721. SF/HGF and c-met antibody were used to stimulate and block SF/HGF-c-met signal transduction. Cell morphology, mobility, and proliferation were respectively compared by microscopic observation, wound healing assay and cell growth curve.

RESULTS: HCC malignancy appeared to be relative to its met-SF/HGF expression. In MHCC-1, c-met expression was much stronger than that in other cell lines with lower potential of metastasis and only SF/HG F autocrine existed in MHCC-1. After sf/hgf cDNA transfection or conditioned medium of MHCC-1 stimulation, SMMC7721 changed into elongated morphology, and the abilities of proliferation (P < 0.05) and mobility increased. Such bio-activity could be blocked by c-met antibody (P < 0.05).

CONCLUSION: The system of SF/HGF-c- met autocrine and paracrine played an important role in development and metastas is potential of HCC. Inhibition of SF/HGF-c-met signal transduction system may reduce the growth and metastasis of HCC.

1,3-dichloro-1,1-dimethyl-3,3-diisopropyldistannoxane

The title compound, [Sn4(CH3)4(C3H7)4Cl4O2] or [Cl[(CH3)2CH]2SnOSn(CH3)2Cl]2, obtained by the reaction of [(CH3)2CH]2SnO and (CH3)2SnCl2, exists as centrosymmetric dimers in the solid state. It contains a central planar four-membered Sn2O2 ring. The coordinate geometry about the Sn atoms is distorted trigonal pyramidal.

Discovery of a series of nonpeptide small molecules that inhibit the binding of insulin-like growth factor (IGF) to IGF-binding proteins

Insulin-like growth factors (IGF-I and II) play an important role in metabolic and mitogenic activities through stimulation of the IGF-I receptor on the cell surface. Although the concentration of IGF in blood and cerebrospinal fluid is quite high (>100 nM), this large pool of IGF is biologically inactive because of its association with six distinct binding proteins, which form high-affinity complexes with IGF. Thus, inhibitors of IGF-binding proteins (IGFBPs), especially IGFBP-3, could potentially alter the distribution between the "free" and "bound" forms of IGF and thereby elevate biologically active IGF-I to exert a beneficial effect on those patients with diseases that respond to the application of exogenous IGF-I. Whereas IGF-I peptide variants, which bind to IGFBPs but not the IGF-I receptor, have been shown to be potent IGF/IGFBP inhibitors, small molecule nonpeptide IGF/IGFBP inhibitors have the potential advantages of oral bioavailability and flexible dosing regimen. Here we report the discovery of several isoquinoline analogues, exemplified by 1 and 2, which bind IGFBP-3 as well as other IGFBPs at low nanomolar concentrations. More importantly, both compounds were shown to be able to release biologically active IGF-I from the IGF-I/IGFBP-3 complex. These results point to the feasibility of developing orally active therapeutics to treat IGF-responsive diseases by optimization of the lead molecules 1 and 2.

Application of double-impedance system and cyclic voltammetry to study the adsorption of fullerols (C60(OH)n) on biological peptide-adsorbed gold electrode

The adsorption of fullerols (C60(OH)n) on glutathione-adsorbed gold electrode was characterized by using double-impedance system, i.e., electrochemical quartz crystal impedance and electrochemical impedance spectroscopy, and cyclic voltammetry. The time courses of piezoelectric parameters were used to reflect the changes of interfacial physical properties, such as mass, density-viscosity, and dielectric constant, during the adsorptions of peptide and fullerols onto electrode. The electrochemical impedance based on the simple equivalent electric network were also simultaneously measured and provided electrochemical interface information, e.g., double-layer capacitance and charge-transfer resistance. It was found that the double-impedance responses were varied with the forms of glutathione. It was also shown that the frequency curves due to the adsorption of oxidized (GSSG) and reduced (GSH) glutathione could be exhibited as different kinetic equations. The heterogeneous charge-transfer rate constants of ferricyanide/ferrocyanide before and after the peptide and fullerols adsorption were determined by CV and EIS methods. The results showed that the proposed method has potential applications in interfacial studies of biomaterials, since these combined techniques have advantages in real time providing multidimensional piezoelectric and electrochemical impedance information.

Identification of a nonpeptide ligand that releases bioactive insulin-like growth factor-I from its binding protein complex

Insulin-like growth factor-I (IGF-I) has both metabolic and mitogenic activities mediated through interaction with the type 1 IGF receptor. The circulation of IGF-I in blood and interstitial fluid is not free but bound mostly to a family of six high affinity IGF-binding proteins, which form stable complexes with IGF and neutralize its bioactivity. Therefore, displacement of this large pool of endogenous IGF from the binding proteins could elevate "free" IGF levels to elicit beneficial effects in diabetes and other IGF-responsive diseases comparable with those produced by administration of exogenous IGF-I. We report here the identification of a nonpeptide ligand NBI-31772, which displaces IGF-I from all six IGF-binding proteins at low nanomolar concentrations from screening of the in-house chemical libraries. Furthermore, the released free IGF-I was shown to be biologically active in an in vitro bioassay. Thus, NBI-31772 could serve as a valuable lead molecule for the design of novel therapeutics to treat diabetes and other IGF-responsive diseases.

[Study of intraoperative mitomycin C in preventing recurrence after pterygium surgery]

OBJECTIVE

To explore the feasibility of intraoperative application of mitomycin C (MMC) in pterygium and observe the ultrastructure change of pterygium with or without intraoperative application of MMC.

METHODS

Sixty two eyes of 57 patients with primary pterygium were randomly divided into MMC group and control group, 29 patients (32 eyes) in MMC group underwent transposition with intraoperative application of MMC (0.4 mg.ml-1 for 1 minute), whereas 28 patients (30 eyes) in control group underwent transposition. The recurrence rate, complications and side effects were observed and compared between the two groups. The ultrastructure of pterygium with or without intraoperative application of MMC was studied with transmission electron microscopy. The mean follow-up was(7.6 +/- 3.4) months (1-13 minths).

RESULT

Eleven eyes of the 30 eyes in control group (36.%) showed recurrence, whereas only 2 of 32 eyes (6.3%) in MMC group showed recurrence (P < 0.005). No severe complication and side effect appeared during the follow-up. Most of fibroblasts in pterygium that underwent intraoperative MMC occurred the change of rough endoplasmic reticulum (RER) dilatation.

CONCLUSION

Intraoperative MMC appears to be an effective treatment in preventing recurrence of primary pterygium. The fibroblasts in pterygium have RER dilatation after application of MMC for 1 minute during the operation.

Sequence determination of reduction potentials by cysteinyl hydrogen bonds and peptide pipoles in [4Fe-4S] ferredoxins

A sequence determinant of reduction potentials is reported for bacterial [4Fe-4S]-type ferredoxins. The residue that is four residues C-terminal to the fourth ligand of either cluster is generally an alanine or a cysteine. In five experimental ferredoxin structures, the cysteine has the same structural orientation relative to the nearest cluster, which is stabilized by the SH...S bond. Although such bonds are generally considered weak, indications that Fe-S redox site sulfurs are better hydrogen-bond acceptors than most sulfurs include the numerous amide NH...S bonds noted by Adman and our quantum mechanical calculations. Furthermore, electrostatic potential calculations of 11 experimental ferredoxin structures indicate that the extra cysteine decreases the reduction potential relative to an alanine by approximately 60 mV, in agreement with experimental mutational studies. Moreover, the decrease in potential is due to a shift in the polar backbone stabilized by the SH...S bond rather than to the slightly polar cysteinyl side chain. Thus, these cysteines can "tune" the reduction potential, which could optimize electron flow in an electron transport chain. More generally, hydrogen bonds involving sulfur can be important in protein structure/function, and mutations causing polar backbone shifts can alter electrostatics and thus affect redox properties or even enzymatic activity of a protein.

Use of a quartz crystal impedance technique to monitor the degradation of chondroitin sulfate by hyaluronidase

A new quartz crystal impedance hyaluronidase sensing technique, which is based on the changes in viscosity and density during the enzymatic hydrolysis of chondroitin sulfate (CS) by hyaluronidase (HAse), is established in this paper. The variations of equivalent circuit parameters of the piezoelectric quartz crystal (PQC) during the enzymatic degradation are discussed. The initial hydrolysis rate of CS by HAse is obtained from the changes in viscosity and density with incubation time. Kinetic parameters (the Michaelis constant K(m) and the maximum hydrolysis rate V(max)) of the degradation process are estimated by using a linear method of Lineweaver-Burk plot. K(m) is 2.73 +/- 0.20 mg.ml(-1) and V(max) is -(5.43 +/- 0.38) x 10(-4) kg.m(-2).s(-1/2).min(-1.)

[Audiological findings of the aging across the urban and rural of Suzhou]

OBJECTIVE

To determine the epidemiological characteristics of old people's hearing.

METHOD

Questionnaires, physical examination, audiometry and bio-chemical tests were performed on the elders above 60 years old in part of the urban and rural area of Suzhou with random sample survey.

RESULT

A total of 1,040 individuals was investigated, among which 505 were from urban, and 535 were from rural. 33 of 505 senior citizen (6.53%) were nososacusis, 282 (55.84%) were presbycusis and 21 (4.16%) were noise-induced deafness; In the rural area, 35 of 535 (6.54%) were nososacusis, 232 (43.36%) were presbycusis, and 4 (0.75%) were noise deafness. There was significant difference of the incidence of presbycusis between urban and rural. The audiometric thresholds chart manifested that the threshold elevated with age increasing especially in high-frequency.

CONCLUSION

The etiology of hearing loss of elders was mainly due to presbycusis. The higher incidence of psychotic disorder in urban probably caused a correspondingly higher incidence of presbycusis. So the prevention and cure of some age-induced diseased (e.g. hypertension, arteriosclerosis and diabetes) may be helpful to release and improve presbycusis.

Chimera formation of platelet GP II b Bak a/b by intrauterine transplantation of fetal liver stem cells

OBJECTIVE

To investigate whether artificial heterozygous chimeras of platelets can be established by intrauterine transplantation of fetal liver stem cells and evaluate its potential use for the treatment of Glanzmann thrombasthenia.

METHODS

Platelet glycoprotein (GP) II b Bak a/b (or GP II b I le843Ser) was used as a genetic marker. A homozygous 16-week-old Bak a/a fetus (as donor) and a homozygous 16.5-week-old Bak b/b fetus (as recipient) were screened from 42 pregnant women hospitalized for abortion. PCR with allele specific primers and FOK I digestion based on PCR products were used. Aborted donor fetal liver cell suspensions were prepared and intrauterine transplantation was carried out by infusion of 4 ml fetal liver cells (22 x 10(5)) into the recipient umbilical vein under ultrasonic visualization.

RESULTS

At gestation termination (abortion), 21 days after transplantation, chimera GP II b Bak a/b of the recipient were detected by FOK 1 digestion based on PCR from DNA and RT-PCR from platelet RNA.

CONCLUSION

Intrauterine transplantation of fetal liver cell may provide an effective way for curing GT or other inherited diseases.

Systemic IFN-beta gene therapy results in long-term survival in mice with established colorectal liver metastases

Most patients succumbing to colorectal cancer fail with liver-predominant metastases. To make a clinical impact in this disease, a systemic or whole-liver therapy may be required, whereas most cancer gene therapy approaches are limited in their ability to treat beyond local disease. As a preclinical model for cancer gene therapy, recombinant adenovirus containing the human IFN-beta (hIFN-beta) cDNA was delivered systemically in nude mouse xenograft models of human colorectal cancer liver metastases. The vector targeted hepatocytes that produced high levels of hIFN-beta in the liver, resulting in a profound apoptotic response in the tumors and significant tumor regression. hIFN-beta gene therapy not only resulted in improved survival and long-term cure in a micrometastatic model, but provided similar benefits in a clinically relevant gross disease model. A similar recombinant adenovirus containing the murine IFN-beta (mIFN-beta) cDNA also resulted in a therapeutic response and improved survival in syngeneic mouse models of colorectal cancer liver metastases. Depletion studies demonstrate a contribution of natural killer cells to this therapeutic response. The toxicity of an adenoviral vector expressing murine IFN-beta in a syngeneic model is also presented. These encouraging results warrant further investigation of the use of cancer gene therapy for targeting metastatic disease.

Isolation and purification of the ovulation-inducing factor from seminal plasma in the bactrian camel (Camelus bactrianus)

The purpose of this study was to extract, identify and partially characterize a newly found ovulation-inducing factor, and thus gain our understanding of induced ovulation in biology. In our preliminary research, an ovulation-inducing factor (OIF) was isolated and purified from seminal plasma of the bactrian camel by ion-exchange chromatography on DEAE-cellulose, HPLC and reverse-phase HPLC. The OIF is a peptide with 74 residues and GnRH-like bioactivity, which is heat-stable in camel seminal plasma because the OIF is wrapped up in several protein layers with different properties. However, purified OIF is degraded when it is exposed to oxygen or is heated in water. According to the analysis of amino acid components and partial amino acid sequence aminated N-terminus, and its molecular weight, the OIF is completely different from the native-LHRH, LH, HCG, PMSG and PGF-2alpha. The OIF is a novel ovulation hormone in the bactrian camel, but is similar to that reported in the bull.

[The effects of leptin on proliferation and function of human osteoblast]

OBJECTIVE

To observe the effect of leptin on osteoblast.

METHODS

Human osteoblast primary culture was carried out, and the morphology and function of osteoblast were observed. The effects of different levels of leptin on osteoblast in different days were assessed by MTT colorimetry. Osteocalcin production was measured also.

RESULTS

Human osteoblasts were fusiform in shape and were positive for alkaline phosphatase by histochemical staining, positive for osteocalcin by immunofluorescence staining, and positive by Alizarin Reds staining after mineralized upon supplementation with ascorbate and beta-glycerophosphate. On the first, second and third days, the proliferation of osteoblast, cultured with different concentrations of leptin, had no changes. The leptin-stimulated synthesis of osteocalcin of cells was found to be dose-dependent (P < 0.05), but not time-dependent (P > 0.05).

CONCLUSION

The above data indicated that there were no evidences for the effects of leptin on the proliferation of human osteoblast, but leptin could enhance the function of human osteoblast.

Activity identification of anti-caspase-3 mRNA hammerhead ribozyme in both cell-free condition and BRL-3A cells

OBJECTIVE

To study the transcription effects and cleavage activities of rat caspase-3 specific hammerhead ribozyme (Rz107) in both cell-free conditions and BRL-3A cells.

METHODS

Rat caspase-3 gene fragment was cloned into the pGEM-T EASY vector under the T7 promoter control. The 32P-labeled caspase-3 transcript was the target-RNA. Rz107 genes designed against caspase-3 mRNA were cloned into vector p1.5 between 5'-cis-Rz and 3'-cis-Rz. 32P-labeled ribozyme transcripts were incubated with target-RNAs at different conditions and autoradiographed after denaturing gel-electrophoresis. Rz107 was electroporated into BRL-3A cells and the Rz107 expression was analyzed by RT-PCR.

RESULTS

In cell-free conditions, Rz107 was active at 37 degrees C. The optimal temperature was 50 degrees C. The Km and Kcat were 14.13 nmol/L and 2.31.min-1 respectively. Intracellular cleavage efficiency of Rz107 was 37%, as analyzed by RT-PCR. This indicated that the design of Rz107 was correct, and Rz107 had the activity of common enzymes.

CONCLUSIONS

Rz107 in cell-free conditions possessed perfect specific catalytic cleavage activity, and it can also cleave the target RNA successfully in cells. The results illustrate the feasibility of ribozyme therapy as a potential alternative approach for treating liver disease caused by apoptosis.

[The risk of sustained amenorrhea in patients with systemic lupus erythematosus receiving intermittent pulse cyclophosphamide therapy]

OBJECTIVE

To determine the risk of sustained amenorrhea in premenopausal women with systemic lupus erythematosus (SLE) receiving intermittent pulse cyclophosphamide (CTX) therapy.

METHODS

Prospectively comparing the amenorrhea rate of 51 cases receiving intermittent pulse cyclophosphamide therapy versus that of 22 cases receiving intermittent pulse methylprednisolone (MP) therapy.

RESULTS

The amenorrhea rate was higher in the CTX group (19.6%) than in the MP group (P = 0.025). In the CTX group, the amenorrhea rate of patients aged over 30 was higher than that of patients aged 30 or below 30 (P = 0.0018).

CONCLUSION

Pulse CTX therapy in fertile women with SLE is associated with increased rate of sustained amenorrhea, and the older the patient is, the higher risk for sustained amenorrhea the patient runs.

A comparative study on the viscoelasticity and morphology of polyaniline films galvanostatically grown on bare and 4-aminothiophenol-modified gold electrodes using an electrochemical quartz crystal impedance system and SEM

The equivalent-circuit parameters of the 9-MHz piezoelectric quartz crystal (PQC) resonance were measured in situ during the galvanostatic polymerization of aniline on 4-aminothiophenol(4-ATP)-modified and bare Au electrodes for ca. 2000 s, respectively. Two polymerization media, 0.100 mol L-1 aniline in 1.0 mol L-1 H2SO4 and in 2.0 mol L-1 HClO4 aqueous solutions, and two values of the current density, 12 and 36 microA cm-2, were used. At identical levels of the resonant frequency shifts in the solutions, obviously greater increases in the motional resistance (R1) were found after aniline polymerization on bare Au electrodes, though the absolute values of delta f0/delta R1 were all large; also, the resonant frequency shifts in air (delta f0g) were considerably smaller for PANI films grown on bare Au electrodes. It is thus concluded that, under identical polymerization conditions, (1) the PANI film grown on a bare gold electrode is rougher, less compact, and can entrap solution more notably; (2) the deposition efficiency of PANI is higher on a 4-ATP-modified Au electrode, owing to a significantly greater observed "dry" frequency shift, and thus a greater "net" mass value of the polyaniline backbone. SEM observations have confirmed that PANI films on 4-ATP-modified Au electrodes were smoother and more compact than those grown on bare Au ones under identical polymerization conditions. In addition, a technique of simultaneous measurements of the electroacoustic admittance of the PQC resonance and the electrochemical impedance was used to monitor the adsorption of 4-ATP onto a PQC gold electrode.

Ribozyme-mediated inhibition of caspase-3 activity reduces apoptosis induced by 6-hydroxydopamine in PC12 cells

6-Hydroxydopamine (6-OHDA) is a neurotoxin used in the induction of experimental Parkinson's disease in both animals and PC12 cells, which are derived from rat pheochromocytoma tumors and have many properties similar to dopamine neurons. Biochemical and molecular approaches have shown that low doses of 6-OHDA induce apoptosis in PC12 cells and, in the processing of apoptosis, caspases are crucial mediators, and caspase inhibition is sufficient to rescue PC12 cells from apoptosis induced by 6-OHDA. However, because this caspase inhibition targets multiple caspases, it is not known whether a single caspase is primarily responsible for effecting cell death in this model. To assess the particular member (caspase-3) of the ced-3 family relevant to cell death and to position their activation within the apoptotic pathway, we constructed a hammerhead ribozyme directed against rat caspase-3, which could downregulate the expression of caspase-3 in vitro and in vivo, and transfer to PC12 cells. The results show that the ribozymes against caspase-3 could protect PC12 cells from apoptosis induced by low doses of 6-OHDA. The PC12 cell transfected with the ribozymes shows a significant decrease in caspase-3 activity compared with control cells at various time points. Parallel to the reduced caspase-3 protease activity, similar decreased levels of apoptotic cells and DNA fragmentation were also assessed by staining with Hoechst 33258 and ELISA, respectively. Overexpression of p35, a general caspase inhibitor, also protected PC12 cells from apoptosis. These results confirm that caspases play an important role in 6-OHDA-induced PC12 cell apoptosis and indicate that caspase-3 itself is one of the crucial mediators of neurotoxin-induced PC12 cell apoptosis.

Marek's disease virus latency

MDV latency is defined as the persistence of the viral genome in the absence of production of infectious virus except during reactivation. A number of systems for studying MDV latency exist, and most involve the use of lymphoblastoid cells or tumors. It has been difficult to divorce latency and transformation. Understanding the relationship between these two states remains a major challenge for the MDV system. Based on their patterns of expression, the MDV LATs are apt to be important in the balance between latent and lytic infections. The LATs are a complex group of transcripts. The profile of gene expression that characterizes latency differs among all herpesviruses, and MDV is no exception. MDV LATs bear little resemblance to LATs of other alphaherpesviruses or to the LATs of other lymphotropic herpesviruses. LAT splicing patterns are complex and the relationships among various spliced species or between these species and the large 10-kb transcript are unknown. In addition, the existence of any protein gene products of significance is unknown at this time. More work is needed to further investigate the significance and function of these RNAs. Better technology to construct mutants in the MDV system is badly needed, since the analysis of mutants in the chicken is a powerful and unique advantage of the MDV system.

[Immune response induced by hepatitis B DNA vaccine pCI-S-IRES- ProT alpha]

OBJECTIVE

To investigate immune response in mice inoculated with DNA vaccine.

METHODS

pCI-S and pCI-S-IRES- ProT alpha were constructed by gene technology, transferred into cell line NIH-3T3 mediated by lipofectamine. Mice were inoculated with these plasmids too. HBsAg and HBsAb were detected by ELISA, and transcriptions of these plasmids were detected by RT-PCR.

RESULTS

pCI-S -IRES- ProT alpha, and pCI-S were effectively expressed in cultured cells and vaccinated animals. Humoral immune and specific T-cell proliferative responses were stronger in pCI-S-IRES group than pCI-S group.

CONCLUSIONS

Plasmids coexpression of prothymosin alpha and hepatitis B surface antigen can improve immune responses significantly.

[Influence of scatter factor/hepatocyte growth factor on the growth and transmission of hepatocarcinoma SMMC 7721 cells]

OBJECTIVE

To explore the influence of scatter factor/hepatocyte growth factor (SF/HGF) on the growth and transmission of hepatocarcinoma SMMC 7721 cells by SF/HGF cDNA transfection.

METHODS

Gene transfection was operated by lipofectin method. In vitro, SF/HGF and c-met expression was tested by ELISA and Western blot. Cell proliferation and motility were compared by growth curves and wound healing assays. In vivo, cells before and after transfection were implanted subcutaneously into nude mice respectively to observe tumor growth and metastasis.

RESULTS

After transfection, the expression of SF/HGF reached 694 pg/ml, compared with 0.26 pg/ml before transfection; however the expression of c-met protein did not change obviously. Growth curves showed that cells after transfection proliferated more rapidly than those before transfection and had an increased capability of motility together with enlarged morphological changes. In vivo experiment, tumors originated from SF/HGF(+) cells grew faster than those from SF/HGF(-) cells and had embolism formed inside and metastasis in the corresponding lung tissues, whereas no such findings in SF/HGF(-) cell originated tumors.

CONCLUSIONS

High expression of SF/HGF can stimulate tumor cell proliferation and metastasis in hepatocellular carcinoma

[Study on bolus cyclosphamide treatment for 64 cases of lupus nephritis]

OBJECTIVE

To report on the dosing, efficacy and side-effects of bolus cyclosphamide treatment for lupus nephritis (LN).

METHODS

64 consecutive cases of LN with 10 or more erythrocytes per high-power field, proteinuria (> 1 g of protein per day) and serum creatinine increased (> 133 mumol/L) were treated by bolus therapy with cyclophosphamide (CTX) given monthly for 6 months and then quarterly for 18 months.

RESULTS

49 patients had renal remission (defined as < 10 erythrocytes per high-power field, absence of cellular casts, excretion of < 1 g of protein per day and normal serum creatinine). The mean of doses was 1.1 g for each time (0.6-1.6 g), the mean of times of bolus CTX needed was 3.6 (1-8 times). The adverse events were amenorrhea (in 41% female patients), herpes zoster (in 13% patients) and hemorrhagic cystitis (in 1 patient).

CONCLUSION

The results indicate that monthly bolus CTX therapy is effective and safe for patients with LN. Its adverse effect is relatively not a serious problem.

Structure-activity relationships for a large diverse set of natural, synthetic, and environmental estrogens

Understanding structural requirements for a chemical to exhibit estrogen receptor (ER) binding has been important in various fields. This knowledge has been directly and indirectly applied to design drugs for human estrogen replacement therapy, and to identify estrogenic endocrine disruptors. This paper reports structure-activity relationships (SARs) based on a total of 230 chemicals, including both natural and xenoestrogens. Activities were generated using a validated ER competitive binding assay, which covers a 10(6)-fold range. This study is focused on identification of structural commonalities among diverse ER ligands. It provides an overall picture of how xenoestrogens structurally resemble endogenous 17beta-estradiol (E(2)) and the synthetic estrogen diethylstilbestrol (DES). On the basis of SAR analysis, five distinguishing criteria were found to be essential for xenoestrogen activity, using E(2) as a template: (1) H-bonding ability of the phenolic ring mimicking the 3-OH, (2) H-bond donor mimicking the17beta-OH and O-O distance between 3- and 17beta-OH, (3) precise steric hydrophobic centers mimicking steric 7alpha- and 11beta-substituents, (4) hydrophobicity, and (5) a ring structure. The 3-position H-bonding ability of phenols is a significant requirement for ER binding. This contributes as both a H-bond donor and acceptor, although predominantly as a donor. However, the 17beta-OH contributes as a H-bond donor only. The precise space (the size and orientation) of steric hydrophobic bulk groups is as important as a 17beta-OH. Where a direct comparison can be made, strong estrogens tend to be more hydrophobic. A rigid ring structure favors ER binding. The knowledge derived from this study is rationalized into a set of hierarchical rules that will be useful in guidance for identification of potential estrogens.

A piezoelectric quartz crystal impedance study on Cu(2+)-induced precipitation of bovine serum albumin in aqueous solution

Piezoelectric quartz crystal impedance (QCI) technique was used for monitoring the Cu(2+)-induced precipitation of bovine serum albumin onto the gold electrode. The critical precipitate concentration of Cu(2+) reflected by the significant decrease in the resonant frequency was estimated to be 9.98 x 10(-5) mol x l(-1), and the saturated adherence of the precipitate on the electrode occurred when the Cu(2+) concentration was greater than 9.79x10(-3) mol x l(-1). The frequency shift in air was about 85.5% of that in liquid, and the Deltaf(0)/DeltaR(1) ratio found in solution was 82.67 Hz Omega(-1), suggesting that the frequency response was predominated by the mass change due to precipitate adherence to the electrode surface. The response of the resonant frequency was analyzed using an equation Deltaf=a(0) + a(1) e(-t/tau(1)) + a(2) e(-t/tau(2)). The relationship between the total a(0) values and the Cu(2+) concentration was discussed.

Effect of AQP1 expression level on Co(2) permeability in bovine corneal endothelium

PURPOSE

Corneal endothelial fluid transport is dependent on HCO(3)(-) and CO(2) fluxes. CO(2) permeability (P:CO(2)) measurements in an oocyte expression system and in reconstituted proteoliposomes have suggested that the water channel AQP1 can transport CO(2). An AQP1 knockout mouse model, however, showed no evidence for CO(2) transport through AQP1 in erythrocytes or lung. Because HCO(3)(-) and CO(2) fluxes are essential to endothelial function, the current study was conducted to determine whether AQP1 expression levels in confluent cultures of bovine corneal endothelial cells (BCECs) affects membrane PCO(2).

METHODS

BCEC endogenous AQP1 expression was reduced by antisense oligonucleotide (AO) transfection or adenoviral antisense-AQP1 (AV) infection. AQP1 was overexpressed by adenoviral sense-AQP1 (SV) infection, which directs expression of recombinant AQP1.

RESULTS

Expression of AQP1 and osmotic water permeability (control P(f) = 0.046 +/- 0.005 cm/sec) were reduced 45% and 36.5%, respectively, by AO transfection and reduced 67% and 49%, respectively, by AV infection. SV infection induced a more than threefold overexpression of AQP1 but showed only a 37% increase in P(f). Adenoviral empty virus (EV) infection did not change AQP1 expression or P(f). PCO(2) was determined by measuring the rate of intracellular pH decrease after exposure to CO(2)/HCO(3)(-)-rich solutions, as measured by the pH-sensitive fluorescent dye 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF). Apparent PCO(2) of BCEC (0.0036 +/- 0.00023 cm/sec) was not different among control, oligonucleotide-transfected, and adenoviral-infected cells. P(f) could also be reduced more than 50% by 3 to 5 minutes' exposure of control cells to 0.5 mM p-chloromercuriphenylsulfonic acid (pCMBS), but this had no effect on rates of intracellular pH decrease.

CONCLUSIONS

AQP1 does not contribute to PCO(2) in corneal endothelial cells.

mRNA and protein expression of Fas associated death domain protein in apoptosic hepatocyte induced by tumor necrosis factor-alpha

OBJECTIVE

To study the expression of protein and mRNA of Fas associated death domain protein (FADD) in the apoptosic hepatocyte induced by D-galactosamine (GalN) and TNF-alpha.

METHODS

Fulminant hepatic failure (FHF) was induced by injection of GalN into sensitized BALB/c mice by TNF-alpha. Hepatocyte apoptosis was examined by electric microscopy, in site end labeling (ISEL) and DNA electrophoresis on 1.5% agarose gel. The expression of protein and mRNA of FADD were detected by immunohistochemistry and PT-PCR.

RESULTS

GalN/TNF-alpha may induce hepatocyte apoptosis, necrosis and liver failure. The expression of protein and mRNA of FADD were positively correlative with the apoptosic hepatocytes.

CONCLUSION

TNF-alpha induces hepatocyte apoptosis by up regulation expression of FADD protein.