Telomerase inhibition strategies by siRNAs against either hTR or hTERT in oral squamous cell carcinoma

Human telomerase RNA (hTR) and human telomerase reverse transcriptase (hTERT) are considered effective molecular targets for current anticancer therapy. In this study, we investigated the therapeutic effects of targeting hTR and hTERT individually or in combination by recombinant adenovirus-delivered small interfering RNA (siRNA) in oral squamous cell carcinoma (OSCC) Tca8113. Further, we screened the optimal strategy for RNA interference. Our results show that these different recombinant adenoviruses specifically reduced the levels of hTR mRNA, hTERT mRNA, hTERT protein and telomerase activity in Tca8113 cells. Moreover, they successfully inhibited xenograft tumor growth in nude mice. The potency of their antitumor activities was ranked as follows: anti-hTR >anti-hTR+anti-hTERT >anti-hTERT. Therefore, we demonstrated that the siRNA-expressing recombinant adenoviruses were an effective anticancer tool for treatment of OSCC. Furthermore, the anticancer effect of solely targeting hTR was more direct and efficient, compared with the effect of targeting hTR and hTERT in combination, or hTERT exclusively. The mechanism of this anticancer effect in OSCC was not only related to the inhibition of cell proliferation and the induction of cell apoptosis, but might also involve the inhibition of tumor angiogenesis.

Transplantation of umbilical cord mesenchymal stem cells alleviates lupus nephritis in MRL/lpr mice

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease, which, despite the advances in immunosuppressive medical therapies, remains potentially fatal in some patients, especially in treatment-refractory patients. This study found that transplantation of umbilical cord mesenchymal stem cells (UC-MSCs) has the same therapeutic effect as transplantation of bone marrow mesenchymal stem cells (BM-MSCs), which has been reported to be efficient in treating SLE-related symptoms in MRL/lpr mice. Multi-treatment (at the 18th, 19th, and 20th weeks of age) of 1 × 10(6) UC-MSCs was able to decrease the levels of 24-h proteinuria, serum creatinine, and anti-double-stranded DNA (dsDNA) antibody, and the extent of renal injury such as crescent formation in MRL/lpr mice. A lower, but still significant, reduction in these parameters was also observed in mice receiving a single dose of UC-MSCs (at the 18th week). UC-MSCs treatment also inhibited expression of monocyte chemotactic protein-1 (MCP-1) and high-mobility group box 1 (HMGB-1) expression in a similar fashion. UC-MSCs labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE) were found in the lungs and kidneys 1 week post infusion. In addition, after 11 weeks post UC-MSCs infusion, human cells were found in kidney of UC-MSCs-treated mice. These findings indicated that UC-MSCs transplantation might be a potentially promising approach in the treatment of lupus nephritis, possibly by inhibiting MCP-1 and HMGB-1 production.

Anchorage-independent cell growth signature identifies tumors with metastatic potential

The oncogenic phenotype is complex, resulting from the accumulation of multiple somatic mutations that lead to the deregulation of growth regulatory and cell fate controlling activities and pathways. The ability to dissect this complexity, so as to reveal discrete aspects of the biology underlying the oncogenic phenotype, is critical to understanding the various mechanisms of disease as well as to reveal opportunities for novel therapeutic strategies. Previous work has characterized the process of anchorage-independent growth of cancer cells in vitro as a key aspect of the tumor phenotype, particularly with respect to metastatic potential. Nevertheless, it remains a major challenge to translate these cell biology findings into the context of human tumors. We previously used DNA microarray assays to develop expression signatures, which have the capacity to identify subtle distinctions in biological states and can be used to connect in vitro and in vivo states. Here we describe the development of a signature of anchorage-independent growth, show that the signature exhibits characteristics of deregulated mitochondrial function and then demonstrate that the signature identifies human tumors with the potential for metastasis.

Multiple roles of the p75 neurotrophin receptor in the nervous system

The p75 neurotrophin receptor (p75NTR) is a transmembrane protein that binds nerve growth factor (NGF) and has multiple functions in the nervous system where it is expressed widely during the developmental stages of life, although expression decreases dramatically by adulthood. Expression of p75NTR can increase in pathological states related to neural cell death. p75NTR is a member of the tumour necrosis factor (TNF) receptor family and it consists of intracellular, transmembrane and extracellular domains which are different from other TNF receptors. Either by interacting with tropomyosin receptor kinase (Trk) receptors or via the independent binding of neurotrophin, p75NTR can induce neurite outgrowth and cellular survival or cell apoptosis through several complicated signal transduction pathways. Most of these signalling pathways remain to be elucidated. By interacting with different cellular factors, p75NTR can induce neuron growth cone collapse or regrowth. p75NTR is also expressed in a variety of glial populations. The many functions of p75NTR require further study.

Procyanidin induces apoptosis and necrosis of prostate cancer cell line PC-3 in a mitochondrion-dependent manner

Our objective was to study the effects of procyanidin on the cell death of human hormone-resistant prostate carcinoma cell line PC-3 and its mechanism. PC-3 cells were treated with procyanidin of different concentrations. The cell apoptosis rates were detected by annexin V-FITC and propidium iodide double staining followed by flow cytometry (FCM) analysis. Mitochondrial membrane potential (Deltapsim) was analyzed by FCM with rhodamine 123 staining. After 24 hours of treatment with 300 microg/mL procyanidin, the apoptosis rate of PC-3 cells was 44.86%, and Deltapsim was significantly decreased by 87.30%. With the extending of procyanidin treatment, the apoptosis rate decreased whereas the necrosis rate increased. Procyanidin could induce apoptosis and necrosis in PC-3 cells, which might be related to down-regulation of Deltapsim.

Inhibition of telomerase RNA (hTR) in cervical cancer by adenovirus-delivered siRNA

Small interfering RNA (siRNA) has become a powerful tool for selectively silencing gene expression in cultured mammalian cells. In this study, a 67-bp oligonucleotide encoding human telomerase RNA (hTR) was introduced into pSIREN, a shuttle vector for construction of recombinant adenovirus. Then the U6-RNA promoter and siRNA-encoding insert were cut out from the pSIREN and subcloned into pAdeno-X to construct the plasmid pAd-hTR. After the pAd-hTR was transfected into a mammalian cell line HEK-293, adenovirus carrying the hTR-targeting siRNA (Ad-hTR-siRNA) was obtained. We performed a series of experiments to demonstrate silencing of the telomerase mediated by Ad-hTR-siRNA in HeLa cells. Compared with control virus (Ad-NT-siRNA), Ad-hTR-siRNA significantly reduced both hTR mRNA level (by 70.21%) and telomerase activity (by 58.87%) in HeLa cells. Moreover, it induced apoptosis in HeLa cells. Treatment of subcutaneous tumor xenografted with Ad-hTR-siRNA could slow down tumor growth, at least partially due to the induction of apoptosis (P<0.05) in vivo. Taken together, our results demonstrated efficient and specific knockdown of telomerase in HeLa cell line by the hTR siRNA, and indicated the prospect of applying this siRNA expressing recombinant adenovirus system in cancer gene therapy.

A systematic review and economic model of the clinical and cost-effectiveness of immunosuppressive therapy for renal transplantation in children

OBJECTIVES

To review the clinical and cost-effectiveness of basiliximab, daclizumab, tacrolimus, mycophenolate mofetil (MMF), mycophenolate sodium (MPS) and sirolimus as possible immunosuppressive therapies for renal transplantation in children.

DATA SOURCES

Electronic databases were searched up to November 2004.

REVIEW METHODS

Data from selected studies were extracted and quality assessed. An economic model [Birmingham Sensitivity Analysis paediatrics (BSAp)] was produced based on an adaptation of a model previously developed for the assessment of the cost-effectiveness of immunosuppressants in adults following renal transplant.

RESULTS

For the addition of basiliximab, one unpublished paediatric randomised control trial (RCT), reported that the addition of basiliximab to tacrolimus-based triple therapy (BTAS) failed to significantly improve 6-month biopsy-proven acute rejection (BPAR), graft function, graft loss and all-cause mortality. No significant difference between groups was seen in 6-month or 1-year or longer graft loss, all-cause mortality and side-effects. In a meta-analysis of adult RCTs, the addition of basiliximab to a ciclosporin, azathioprine and steroid regimen (CAS) significantly reduced short-term BPAR. There was no significant difference in short- or long-term graft loss, all-cause mortality or side-effects. One adult RCT was included for the addition of daclizumab to CAS, which reported reduced 1-year BPAR, although no difference between groups was seen in either 1- or 3-year graft loss, all-cause mortality and side-effects. For tacrolimus versus ciclosporin, one unpublished paediatric RCT found that a regimen of tacrolimus, azathioprine and a steroid (TAS) reduced 6-month BPAR and improved graft function [glomerular filtration rate (GFR)] compared with CAS. This improvement in BPAR with tacrolimus was as shown in the meta-analysis of adult RCTs. There was evidence, particularly in children, that in comparison with ciclosporin, tacrolimus may reduce long-term graft loss, although there is no benefit on total mortality. The total level of withdrawal in children was reduced in children receiving tacrolimus. Adult RCTs showed an increase in post-transplant diabetes mellitus with tacrolimus. For MMF versus azathioprine, a meta-analysis of adult RCTs showed MMF [regimen of ciclosporin, MMF and a steroid (CMS)] to reduce 1-year BPAR compared with azathioprine (CAS). There was evidence, particularly in children, that in comparison with azathioprine, tacrolimus may reduce long-term graft loss, although there is no benefit on total mortality. There was an increase in the level of cytomegalovirus infection with MMF, although the overall level of withdrawal due to adverse events was not different to that of azathioprine-treated adults. No study comparing MPS with azathioprine (CAS) was identified. In an adult RCT comparing MMF with MPS, there was no significant difference between groups in 1-year efficacy or side-effects. One unpublished paediatric RCT assessed the addition of sirolimus to CAS. BPAR, graft loss and all-cause mortality were not reported. In two adult RCTs, compared with azathioprine, sirolimus reduced 1-year BPAR, reduced graft function (as assessed by an increased serum creatinine) and increased the level of hyperlipidaemia. No significant differences were seen in other efficacy and side-effect outcomes. On an adult RCT comparing sirolimus with ciclosporin, there were no significant differences between groups in 1-year efficacy or side-effects with the exception of an increased level of hyperlipidaemia with sirolimus substitution. Both the assessment group and drug companies assessed the cost-effectiveness of the newer renal immunosuppressants currently licensed in children using an adaptation (BSAp) of the Birmingham Sensitivity Analysis (BSA) model. This model is based on a 10-year extrapolation of 1-year BPAR results sourced from paediatric RCTs or adult RCTs (where paediatric RCTs were not available). The addition of basiliximab and that of daclizumab to CAS was found to increase quality-adjusted life-years (QALYs) and decreased overall costs, a finding that was robust to sensitivity analyses. The incremental cost-effectiveness ratio (ICER) of replacing ciclosporin with tacrolimus was highly sensitive to the selection of the hazard ratio for graft loss from acute rejection, dialysis costs and the incorporation (or not) of side-effects. The ICERs for tacrolimus versus ciclosporin ranged from about 46,000 pounds/QALY to about 146,000 pounds/QALY. Although sensitive to varying the hazard ratio for graft loss with acute rejection, the ICER for replacing azathioprine with MMF remained in excess of 55,000 pounds/QALY.

CONCLUSIONS

In general, compared with a regimen of ciclosporin, azathioprine and steroid, the newer immunosuppressive agents consistently reduced the incidence of short-term biopsy-proven acute rejection. However, evidence of the impact on side-effects, long-term graft loss, compliance and overall health-related quality of life is limited. Cost-effectiveness was estimated based on the relationship between short-term acute rejection levels from RCTs and long-term graft loss. Both the addition of daclizumab and that of basiliximab were found to be dominant strategies, that is, regarding cost savings and increased QALYs. The incremental cost-effectiveness of tacrolimus relative to ciclosporin was highly sensitive to key model parameter values and therefore may well be a cost-effective strategy. The incremental cost-effectiveness of MMF compared with azathioprine, although also sensitive to model parameter, was unattractive. There is a particular need for RCTs to assess the use of MMF, MPS and daclizumab for renal transplantation in children where no such evidence currently exists. Future comparative studies need to report not only on the impact of the newer immunosuppressants on short- and long-term clinical outcomes but also on side-effects, compliance, healthcare resource, costs and health-related quality of life.

Imatinib for the treatment of patients with unresectable and/or metastatic gastrointestinal stromal tumours: systematic review and economic evaluation

OBJECTIVES

To assess the clinical and cost-effectiveness of imatinib in the treatment of unresectable and/or metastatic, KIT-positive, gastrointestinal stromal tumours (GISTs), relative to current standard treatments.

DATA SOURCES

Electronic databases.

REVIEW METHODS

As there were no randomised trials that have directly compared imatinib with the current standard treatment in patients with advanced GIST, this review included non-randomised controlled studies, cohort studies, and case series that reported effectiveness results of treatment with imatinib and/or other interventions in patients with advanced GIST. The effectiveness assessment was based on the comparison of results from imatinib trials and results from studies of historical control patients. Economic evaluation was mainly based on an assessment and modification (when judged necessary) of a model submitted by Novartis.

RESULTS

Evidence from published uncontrolled trials involving 187 patients, and from abstracts reporting similar uncontrolled trials involving 1700 patients, indicates that approximately 50% of imatinib-treated individuals with advanced GIST experience a dramatic clinical response in terms of at least a 50% reduction in tumour mass. At present, although useful data are accumulating, it is not possible to predict which patients may respond in this way. Fifteen studies where possible GIST patients had been treated with therapies other than imatinib or best supportive care were also identified. All imatinib-treated patients experienced adverse effects, although they were relatively mild. Overall, imatinib was reported to be well tolerated. The most common serious events included unspecified haemorrhage and neutropenia. Skin rash, oedema and periorbital oedema were the common adverse events observed. Patients on the highest dose regimen (1000 mg per day in one trial) may experience dose-limiting drug toxicity. A structured assessment was carried out of the Novartis economic evaluation of imatinib for unresectable and/or metastatic GIST. The model was clearly presented and well written, its structure and input data were transparent, and the level of simplification was reasonable in terms of the objectives and data availability. However, the original Novartis model overestimated the cost-effectiveness of imatinib because of disproportion of survival and time-to-treatment failure in the imatinib arm, and the use of a possibly biased survival curve for patients in the control arm. The original Novartis model was modified to correct these two important shortcomings, which made it less sensitive to the choice of the survival curve for the control patients. According to the modified Novartis model, the estimated cost per quality-adjusted life-year (QALY) was 85,224 UK pounds (range 51,515--98,889 UK pounds) after 2 years, 41,219 UK pounds (27,331--44,236 UK pounds) after 5 years and 29,789 UK pounds (21,404--33,976 UK pounds) after 10 years. The results from a new Birmingham model were also within the range of estimates from the modified Novartis model.

CONCLUSIONS

Evidence from uncontrolled studies indicates that the treatment with imatinib brings about clinically significant shrinkage of tumour mass in about half of patients with unresectable and/or metastatic, KIT-positive GIST. Results of modelling based on data from uncontrolled studies suggest that imatinib treatment improves survival in patients with unresectable and/or metastatic GIST. The economic evaluation modelling suggests that the cost per QALY gained ranges from 51,515 to 98,889 UK pounds after 2 years, from 27,331 to 44,236 UK pounds after 5 years, and from 21,404 to 33,976 UK pounds after 10 years. Further research is needed into quality of life within trials involving patients with advanced malignancy, and long-term follow-up of adverse events is needed. Subgroup analysis of which, if any, patient types have a better or worse response to imatinib is also required. Analysis of individual patient data may be a good way of exploring these issues. There are many uncertainties surrounding imatinib prescription, such as the length of time patients should be on imatinib, the dose, drug resistance and the optimum time-point in the disease course at which to give the drug. Secondary research such as an update of this systematic review and a reassessment of the model is highly recommended when ongoing trials reach completion.

A comparison of modulation of proliferation of thymocyte by testosterone, dehydroisoandrosterone and androstenedione in vitro

Although the relationship between androgens and the immune system has been well established, the immunomodulatory function of different kinds of androgens on the cellular immunity remains to be defined. In the present study, the in vitro influences of testosterone, dehydroisoandrosterone and androstenedione on the Con A induced proliferation of thymocyte were determined. The results showed that both dehydroisoandrosterone and testosterone suppressed the Con A induced proliferation of thymocyte, while dehydroisoandrosterone was less potent than testosterone. In contrast, relatively high doses of androstenedione augmented the proliferative activities of thymocytes. Taken together, these data implied that small structural changes of androgens result in markedly different biological effects. These findings suggest that the balance between these steroids may be a significant determinant in maintaining immune homeostasis.

p47phox Associates With the Cytoskeleton Through Cortactin in Human Vascular Smooth Muscle Cells

OBJECTIVE

We tested the hypothesis that p47phox associates with the actin cytoskeleton, enabling site-directed activation of NAD(P)H oxidase, and assessed whether these actions influence reactive oxygen species (ROS) generation and signaling by angiotensin II (Ang II) in vascular smooth muscle cells (VSMCs) from human resistance and coronary arteries.

METHODS AND RESULTS

Electroporation of anti-p47phox antibody into VSMCs abrogated Ang II-mediated O2 generation, establishing the requirement for p47phox in this response. Immunfluorescence confocal microscopy demonstrated a cytosolic distribution of p47phox in basal conditions. After Ang II stimulation, p47phox rearranged in a linear fashion, colocalizing with F-actin. Co-immunoprecipitation studies confirmed an association between p47phox and actin and demonstrated an interaction with the actin-binding protein cortactin. Cytoskeletal disruption with cytochalasin prevented p47phox:actin interaction and attenuated ROS formation and p38MAP kinase and Akt phosphorylation by Ang II. Intracellular ROS generation in response to LY83583 (O2 generator) or exogenous H2O2 and Ang II-induced ERK1/2 activation were unaltered by cytochalasin.

CONCLUSIONS

The p47phox:actin interaction, through cortactin, plays an important role in Ang II-mediated site-directed assembly of functionally active NAD(P)H oxidase, ROS generation, and activation of redox-sensitive p38MAP kinase and Akt, but not ERK1/2. These findings demonstrate the importance of an intact actin-cytoskeleton in NAD(P)H oxidase regulation and redox signaling by Ang II in human VSMCs.

Effect of Escherichia coli Heat-labile Enterotoxin on the Myoelectric Activity of the Duodenum in Weaned Pigs

The objective of the present study was to elucidate the effect of subclinical doses of Escherichia coli heat-labile enterotoxin (LT) on the antro-duodenal myoelectric activities of weaned pigs. Twelve weaned pigs were surgically implanted with three pairs of electrodes on the antrum 3 cm before the pylorus, 5 and 20 cm after the pylorus on the duodenum, respectively. An infusion cannula was inserted into the duodenum between duodenal electrodes. Using a wireless telemetry recording system, an electromyography (EMG) tracing lasting at least 24 h was recorded as the control, then another 24-h EMG recording was performed with a bolus intraduodenal infusion of LT (0.1 and 0.5 microg/kg b.w.). After a 1- to 2-day break, a 5-fold higher dose of LT was administered using the same protocol. In the antrum, LT administration barely modified the EMG signal. However, in the duodenum it prolonged the duration of phase II and the migrating myoelectric complex (MMC) cycle when compared with the control. The number of duodenal MMC cycles was also significantly diminished. Moreover, the migrating velocity of phase III was increased. The migrating action potential complex (MAPC) was present both without and with LT, but occurred more frequently following LT administration. In conclusion, LT caused a dose-dependent, lagged alteration in the duodenal MMC in weaned pigs, involving a reduction of the MMC number by lengthening phase II, increased phase III migration velocity, and increased MAPC frequency. The disturbances did not, however, result in diarrhoea and may reflect the induction of a local protection mechanism of the gut to expel unwanted foreign content from the lumen of the upper gut.

c-Src induces phosphorylation and translocation of p47phox: role in superoxide generation by angiotensin II in human vascular smooth muscle cells

OBJECTIVE

The aim of this study was to determine molecular mechanisms whereby c-Src regulates angiotensin II (Ang II)-mediated NAD(P)H oxidase-derived *O2- in human vascular smooth muscle cells (VSMCs).

METHODS AND RESULTS

VSMCs from human small arteries were studied. Ang II increased NAD(P)H oxidase-mediated generation of *O2- and H2O2 (P<0.01). PP2, c-Src inhibitor, attenuated these effects by 70% to 80%. Immunoprecipitation of p47phox, followed by immunoblotting with antiphosphoserine antibody, demonstrated a rapid increase (1.5- to 2-fold) in p47phox phosphorylation in Ang II-stimulated cells. This was associated with p47phox translocation from cytosol to membrane, as assessed by immunoblotting and immunofluorescence. PP2 abrogated these effects. Long-term Ang II stimulation (6 to 24 hours) increased NAD(P)H oxidase subunit expression. c-Src inhibition decreased abundance of gp91phox, p22phox, and p47phox. Confirmation of c-Src-dependent regulation of NAD(P)H oxidase was tested in VSMCs from c-Src-/- mice. Ang II-induced *O2- generation was lower in c-Src-/- than c-Src+/+ counterparts. This was associated with decreased p47phox phosphorylation, blunted Ang II-stimulated NAD(P)H oxidase activation, and failure of Ang II to increase subunit expression.

CONCLUSIONS

c-Src regulates NAD(P)H oxidase-derived *O2- generation acutely by stimulating p47phox phosphorylation and translocation and chronically by increasing protein content of gp91phox, p22phox, and p47phox in Ang II-stimulated cells. These novel findings identify NAD(P)H oxidase subunits, particularly p47phox, as downstream targets of c-Src.

Study of microdeletions in the Y chromosome of infertile men with idiopathic oligo- or azoospermia

PURPOSE

To determine the relationships between idiopathic oligo- or azoospermia and microdeletions of the Y chromosome.

METHODS

Eighteen Y-linked sequence-tagged sites (STSs) in AZF (Azoospermia Factor) region were screened by means of multiplex PCR (Polymerase Chain Reaction) in 50 idiopathic infertile men, including 16 patients with azoospermia, 13 severe oligospermia, and 21 oligospermia.

RESULTS

Microdeletions in the genomic DNA were observed in 8 of 50 cases, 3 with azoospermia, I severe oligospermia, and 4 oligospermia. Total deletion rate was 16.0% (8/50). The deletion regions were concentrated on AZFd and AZFc.

CONCLUSIONS

Microdeletions of the Y chromosome are an important cause for idiopathic oligo- or azoospermia. Multiplex PCR is a useful technique for detecting the microdeletions. To avoid transmission to their offspring, patients with idiopathic oligo- or azoospermia should be screened for microdeletions of the Y chromosome before ICSI treatment for infertility.

[Evaluation of protective efficacy of two tuberculosis DNA vaccines by lung histopathological analysis]

OBJECTIVE

To evaluate the protective efficacy of MPT64 and ESAT6 DNA vaccines from M. tuberculosis.

METHODS

BALB/c mice were randomly divided into five groups and subjected to the following treatments respectively, i.e. immunized with saline (A), plasmid vector (B), M. bovis BCG (C), MPT64 DNA vaccine (D) or ESAT6 DNA vaccine (E); and then infected by intraperitoneal injection with M. tuberculosis H37Rv. The lung histopathological changes were observed 5 or 10 weeks after infection by microscopy.

RESULTS

At 5 weeks after infection, the lung lesions in the mice of group A and B had inflammatory infiltration with epithelial cell granulomas. In the mice of group C, main pathological changes were epithelial cell granulomas with moderate granulate hyperplasia in alveolar walls. The lung lesions of 3 mice in group D and 1 mice in group E were similar to those seen in the mice in group A and B. The lung lesions of 2 mice in group D and 4 mice in group E were similar to those seen in the mice in group C. At 10 weeks after infection, their tuberculous pneumonia tended to recovery. For the mice in groups A, B and D, their lung pathology exhibited tuberculous granulomas consisted of numerous macrophages, lymphocytes and a few epithelial cells with moderate granulate hyperplasia in alveolar walls. For the mice in groups of C and E, their lung developed epithelial cell and lymphocytic granulomas with moderate to severe granulate hyperplasia in alveolar walls. Lung tissue necrosis was not observed in any mouse.

CONCLUSIONS

MPT64 and ESAT6 DNA vaccines from M. tuberculosis could enhance immunity against M. tuberculosis. The protective efficacy of ESAT6 DNA vaccine is stronger than that of MPT64 DNA vaccine, but not stronger than that of Mycobacterium bovis BCG.

Inhibition of Th1- and Enhancement of Th2-Initiating Cytokines and Chemokines in Trichosanthin- Treated Macrophages

Trichosanthin (TCS), the major effective component from Chinese herb Trichosanthes Kirilowii Maxim, is also a potent allergen. Our previous work has shown that TCS can upregulate interleukin-4 (IL-4) and interleukin-13 (IL-13) while inhibit interferon-gamma (IFN-gamma) in mesenteric lymph node cells after TCS immunization. Thus, TCS can arouse a T helper 2 (Th2) response in the draining lymph node. However, little is known about the early effects of TCS on antigen-presenting cells, the initiator of T cell response. In the current study, the effects of TCS on macrophage cytokines and chemokine expression were investigated. Peritoneal macrophages were treated with or without TCS in the presence of lipopolysaccharide (LPS). We found that TCS increased macrophage interleukin-10 (IL-10) and monocyte chemoattractant protein-1 (MCP-1) expression, whereas it decreased interleukin-12 (IL-12) and tumor necrosis factor-alpha (TNF-alpha) expression. Our study clearly demonstrated that TCS, as an allergen, has differential effects on macrophage Th1/Th2 initiative factors, effects that are likely to facilitate its inducing of Th2 and immunoglobulin E (IgE) response.

Hepatitis B virus genotype distribution among chronic hepatitis B virus carriers in Shanghai, China

OBJECTIVE

Hepatitis B virus (HBV) genotype distribution is still unclear in China, where a high prevalence of HBV infection exists, although it is well known that HBV can be classified into six genotypes based on intergroup divergence. The aim of this study was to investigate the epidemiological distribution of HBV genotypes and to clarify further the genotype-related differences in the pathogenicity of HBV.

METHODS

Seminested PCR and restriction fragment length polymorphism analysis were conducted in 97 asymptomatic HBV carriers (ASC) and 46 chronic hepatitis (CH), 37 liver cirrhosis (LC) and 44 hepatocellular carcinoma (HCC) patients in Shanghai, China.

RESULTS

Two hundred and twenty samples (98.2%) were positive for HBV DNA, and of these, 3 (1.4%), 38 (17.2%) and 179 (81.4%) were classified as genotype A, B and C, respectively. There was a statistically significant difference in the distribution of genotypes B and C among various categories of liver diseases (p < 0.01). The distribution of genotype C showed an increasing trend from ASC, CH and LC to the HCC group; in contrast, the distribution of genotype B showed a decreasing trend in the same order. HBeAg positivity was higher in genotype C than in genotype B in all the subjects or in the ASC group alone (p < 0.05, p < 0.01, respectively). More severe liver damage and a higher mean age were observed in genotype C than in genotype B (p < 0.01, p < 0.05, respectively).

CONCLUSIONS

These results indicate the following: (1) genotypes A, B and C of HBV exist in Shanghai, China; (2) genotype C is the major genotype in this area; (3) genotype C is associated with the development of severe liver diseases, and (4) genotype B has a relatively good prognosis.

Depth-resolved two-dimensional stokes vectors of backscattered light and mueller matrices of biological tissue measured with optical coherence tomography

Mueller matrices provide a complete characterization of the optical polarization properties of biological tissue. A polarization-sensitive optical coherence tomography (OCT) system was built and used to investigate the optical polarization properties of biological tissues and other turbid media. The apparent degree of polarization (DOP) of the backscattered light was measured with both liquid and solid scattering samples. The DOP maintains the value of unity within the detectable depth for the solid sample, whereas the DOP decreases with the optical depth for the liquid sample. Two-dimensional depth-resolved images of both the Stokes vectors of the backscattered light and the full Mueller matrices of biological tissue were measured with this system. These polarization measurements revealed some tissue structures that are not perceptible with standard OCT.

Testing Thurstonian Case V ranking models using posterior predictive checks

This paper presents the results of a Monte Carlo study which investigates the validity of the method of posterior predictive checks (PPC) for testing the fit of a Thurstonian Case V ranking model. The PPC method is employed as an alternative to standard goodness-of-fit tests which are of limited use even when the number of items to be ranked is small. Several test quantities are formed to assess the fit of the Case V ranking model to data for various sample sizes and for two types of violations of the Case V assumptions: heterogeneous stimulus variances and rankers from different populations. The study concludes that the PPC method is useful in detecting local and global misfits of a Thurstonian Case V model, even when the ranking data are sparse.

The initial dental health status of British Army Gurkha recruits

AIM

To describe the initial dental health status of British Army Gurkhas who were recruited in 1999 and to compare the present caries data with previous unpublished data from before 1970 and 1983.

DESIGN AND SETTING

A clinical examination was conducted on the 228 Gurkhas, the entire UK intake for 1999, during their second week of military training. The focus of the examinations was on caries experience. A questionnaire was employed to collect demographic data as well as information on the recruits' reported dental behaviour and beliefs.

RESULTS

1999 recruits who reported a dental problem within the past year were significantly more likely to have visited a dentist before compared to those recruits who reported no dental problems. The frequency distributions of D3MFT for the 1983 and 1999 recruits were very similar.

CONCLUSIONS

Gurkha men are at relatively low risk of dental caries and predicted treatment time suggests a relatively small use of resources would be needed to make this group dentally fit. These recruits are an extremely homogeneous group who remain discernible from the general Nepalese population.

[FTIR and fluorescence studies on the europium complexes of multiple ligands]

A series of EuA(m).nB complexes with different molar ratio of ligands and various concentrations of protecting agent were synthesized (A is thenoyltrifluoroacetone, B is a kind of P = O group compound). The properties of these complexes were investigated by FTIR and fluorescence spectroscopy. The fluorescent intensity of complex is related to the reaction condition, the components of complexes.

Propagation of polarized light in turbid media: simulated animation sequences

A time-resolved Monte Carlo technique was used to simulate the propagation of polarized light in turbid media. Calculated quantities include the reflection Mueller matrices, the transmission Mueller matrices, and the degree of polarization (DOP). The effects of the polarization state of the incident light and of the size of scatterers on the propagation of DOP were studied. Results are shown in animation sequences.

Frequency-swept ultrasound-modulated optical tomography in biological tissue by use of parallel detection

A frequency-swept ultrasonic beam was focused into a biological tissue sample to modulate the laser light passing through the ultrasonic beam inside the tissue. Parallel detection of the speckle field formed by the transmitted laser light was implemented with the source-synchronous-illumination lock-in technique to improve the signal-to-noise ratio. The ultrasound-modulated laser light reflects the local optical and mechanical properties in the ultrasonic beam and can be used for tomographic imaging of the tissue. Sweeping the ultrasonic frequency provides spatial resolution along the ultrasonic axis, which is scalable with the frequency span of the sweep. Two-dimensional images of biological tissue with buried objects were successfully obtained experimentally.

The hinge of the human papillomavirus type 11 E2 protein contains major determinants for nuclear localization and nuclear matrix association

The E2 protein of papillomaviruses is a site-specific DNA binding nuclear protein. It functions as the primary replication origin recognition protein and assists in the assembly of the preinitiation complex. It also helps regulate transcription from the native viral promoter. The E2 protein consists of an amino-terminal (N) trans-acting domain, a central hinge (H) domain, and a carboxyl-terminal (C) protein dimerization and DNA binding domain. The hinge is highly divergent among papillomaviruses, and little is known about its functions. We fused the enhanced green fluorescent protein (GFP) with the full-length human papillomavirus type 11 (HPV-11) E2 protein and showed that the resultant fusion, called gfpE2, maintained transcription and replication functions of the wild-type protein and formed similar subnuclear foci. Using a series of GFP fusion proteins, we showed that the hinge conferred strong nuclear localization, whereas the N or C domain was present in both cytoplasm and nucleus. Biochemical fractionation demonstrated that the N domain and hinge, but not the C domain, independently associated with the nuclear matrix. Mutational analyses showed that a cluster of basic amino acid residues, which is conserved among many mucosotropic papillomaviruses, was required for efficient nuclear localization and nuclear matrix association. This mutation no longer repressed the HPV-11 upstream regulatory region-controlled reporter expression. However, a very small fraction of this mutant colocalized with E1 in the nucleus, perhaps by a piggyback mechanism, and was able to support transient replication. We propose that the hinge is critical for the diverse regulatory functions of the HPV-11 E2 protein during mRNA transcription and viral DNA replication.

[Dural arterovenous fistula involving cavernous sinus]

OBJECTIVE

To study the pathogenesis and treatment of dural arteriovenous fistulas (DAVFS) involving the cavernous sinus.

METHODS

32 cases were embolized with particle by microcatheterization via endovascular approach and ervation by digital substraction angiography. Of the 32 cases, 14 were embolized by microsoils through superior petrosal sinus approach into the cavernous sinus.

RESULTS

In 28 of the 32 cases the fistulas were completely embolized angiographically. The fistulas were partly embolized in 4 of the 32 cases. The carotid artery was compressed for 6 months. One week later, the fistula disappeared angiographically. No fistulas were found during the follow-up for 6 months to 8 years.

CONCLUSION

Endovascular treatment of DAVFS involving the cavernous sinus is effective.

Crystallization and preliminary X-ray analysis of luffaculin, a ribosome-inactivating protein from sponge-gourd seeds

Luffaculin is a ribosome-inactivating protein. Crystals suitable for X--ray diffraction were first obtained using the hanging-drop vapour-diffusion method. X-ray studies show that the crystals belong to space group C2, with unit-cell parameters a = 89.90, b = 59.82, c = 55.18 A, beta = 120.81 degrees, and have one molecule in the crystallographic asymmetric unit. The crystals diffract X-rays to at least 2.0 A resolution.

Theoretical and experimental studies of ultrasound-modulated optical tomography in biological tissue

Ultrasound-modulated optical tomography in biological tissue was studied both theoretically and experimentally. An ultrasonic beam was focused into biological tissue samples to modulate the laser light passing through the ultrasonic beam inside the tissue. The ultrasound-modulated laser light reflects the local optical and mechanical properties in the ultrasonic beam and permits tomographic imaging of biological tissues by scanning. Parallel detection of the speckle field formed by the transmitted laser light was implemented with the source-synchronous-illumination lock-in technique to improve the signal-to-noise ratio. Two-dimensional images of biological tissues were successfully obtained experimentally with a laser beam at either normal or oblique incidence, which showed that ultrasound-modulated optical tomography depends on diffuse light rather than on ballistic light. Monte Carlo simulations showed that the modulation depth decreased much more slowly than the diffuse transmittance, which indicated the possibility that even thicker biological tissues can be imaged with this technique.

Full-field mapping of ultrasonic field by light-source-synchronized projection

A simple method for imaging ultrasonic fields in clear media is introduced. A modulated laser source is used to project the ultrasonic field onto a CCD camera. By use of the source-synchronized lock-in detection scheme, 2D images of the amplitude and phase distributions can be determined simultaneously. This technique is experimentally demonstrated with a 1-MHz and a 3.5-MHz ultrasonic transducer operated in continuous-wave mode. This method is very straightforward to implement and can be combined with the traditional tomographic reconstruction technique to obtain the 3D distribution of an ultrasonic field.

Monte Carlo simulation of an optical coherence tomography signal in homogeneous turbid media

The Monte Carlo technique with angle biasing is used to simulate the optical coherence tomography (OCT) signal from homogeneous turbid media. The OCT signal is divided into two categories: one is from a target imaging layer in the medium (Class I); the other is from the rest of the medium (Class II). These two classes of signal are very different in their spatial distributions, angular distributions and the numbers of experienced scattering events. Multiply scattered light contributes to the Class I signal as well as the Class II signal. The average number of scattering events increases linearly with the probing depth. The Class II signal decays much more slowly than the Class I signal whose decay constant is close to the total attenuation coefficient of the turbid medium. The effect of the optical properties of the medium on the Class I signal decay is studied.

[Long-term effect of lamivudine treatment in chronic hepatitis B virus infection]

OBJECTIVE

To evaluate the long-term effect of lamivudine on the loss of serum HBV DNA, HBeAg/antiHBe seroconversion and ALT levels in chronic hepatitis B patients and its safety profile and tolerance with multi-center, randomized, double blind and placebo controlled trial.

METHOD

429 patients with chronic HBV infection as defined by positive HBsAg, HBeAg and HBV DNA were enrolled and randomized into lamivudine and placebo groups. 322 patients received lamivudine 100 mg daily and 107 patients received placebo treatment for 12 weeks. Then, all patients were offered a further 40 weeks of open label lamivudine treatment. The efficacy and safety were evaluated with clinical, biochemical, hematological and virological parameters.

RESULTS

After 12 weeks treatment, HBV DNA response (serum HBV DNA < 1.6 ng/L) rate in lamivudine group was higher than in placebo group (92.2% VS 14.1%, P < 0.01); but at week 52, there was no difference between lamivudine and placebo/lamivudine groups (71.0% VS 77.7%, P > 0.05). Rate of HBV DNA breakthrough in lamivudine group was higher than in placebo/lamivudine group (24.4% VS 8.5%, P < 0.01). Proportion of HBeAg/anti-HBe seroconversion had no difference in two groups (7.5% VS 5.2%, P > 0.05). By week 12, ALT normalization rate in lamivudine group was higher than in placebo group (60.3% VS 27.5%, P < 0.01); but after 52 weeks treatment, there was no difference between two groups (70.9% VS 74.5%, P > 0.05). At week 48, HBV YMDD mutation rate in lamivudine group was higher than in placebo/lamivudine group (14.6% VS 5.0%, P < 0.05). The incidence of adverse events was similar for both lamivudine and placebo/lamivudine group up to week 12 and 52. There was few severe drug-related adverse event.

CONCLUSION

Sustained HBV replication suppression could be obtained from long-term treatment with lamivudine 100 mg daily accompanied with good tolerance and safety.

A randomized double-blind placebo-controlled study of lamivudine in the treatment of patients with chronic hepatitis B virus infection

OBJECTIVE

To evaluate the effect of lamivudine on the loss of serum hepatitis B virus (HBV) DNA, HBeAg/antiHBe seroconversion and ALT levels in chronic hepatitis B patients and its safety profile and tolerance compared with placebo.

METHODS

Four hundred and twenty-nine patients with chronic HBV infection as defined by positive HBsAg, HBeAg and HBV DNA were enrolled and randomized into lamivudine and placebo groups. Three hundred and twenty-two patients received lamivudine 100 mg daily and 107 patients received placebo treatment for 12 weeks. Then, all patients were offered a further 9-month open label lamivudine treatment. The efficacy and safety were evaluated with clinical, biochemical, hematological and virological parameters.

RESULTS

During the 12-week treatment period, 92.2% of lamivudine treated patients became HBV DNA negative (below 1.6 pg/ml) compared with only 14.1% of those receiving placebo (P < 0.01). At the end of 12 week, the sustained negative rate for HBV DNA in the lamivudine treated group was 78.5% compared with the placebo group (11.1%; P < 0.01). There was a trend to a high proportion of patients treated with lamivudine to lose HBeAg (8.1%) and develop antiHBe (10.2%) than treated with placebo (5.3% and 6.4% respectively), but this difference was not statistically significant. Patients with elevated ALT levels at baseline became normal in 60. 3% of the lamivudine treated group compared with the placebo group where only 27.5% were normal (P < 0.01). Lamivudine was well tolerated in a dose of (100 mg daily) and the overall incidence of adverse events was similar to that of the placebo.

CONCLUSIONS

Lamivudine (100 mg daily) is very effective in the inhibition of HBV replication, indicated by the rapid loss of serum HBV DNA, and often accompanied by a decrease of serum ALT levels. Lamivudine is well tolerated without severe adverse events during treatment.

Cross-talk between the aryl hydrocarbon receptor and hypoxia inducible factor signaling pathways. Demonstration of competition and compensation

The aryl hydrocarbon receptor (AHR) and the alpha-class hypoxia inducible factors (HIF1alpha, HIF2alpha, and HIF3alpha) are basic helix-loop-helix PAS (bHLH-PAS) proteins that heterodimerize with ARNT. In response to 2,3,7,8-tetrachlorodibenzo-p-dioxin, the AHR. ARNT complex binds to "dioxin responsive enhancers" (DREs) and activates genes involved in the metabolism of xenobiotics, e.g. cytochrome P4501A1 (Cyp1a1). The HIF1alpha.ARNT complex binds to "hypoxia responsive enhancers" and activates the transcription of genes that regulate adaptation to low oxygen, e.g. erythropoietin (Epo). We postulated that activation of one pathway would inhibit the other due to competition for ARNT or other limiting cellular factors. Using pathway specific reporters in transient transfection assays, we observed that DRE driven transcription was markedly inhibited by hypoxia and that hypoxia responsive enhancer driven transcription was inhibited by AHR agonists. When we attempted to support this cross-talk model using endogenous loci, we observed that activation of the hypoxia pathway inhibited Cyp1a1 up-regulation, but that activation of the AHR actually enhanced the induction of Epo by hypoxia. To explain this unexpected additivity, we examined the Epo gene and found that its promoter harbors DREs immediately upstream of its transcriptional start site. These experiments outline conditions where inhibitory and additive cross-talk occur between the hypoxia and dioxin signal transduction pathways and identify Epo as an AHR-regulated gene.

Two-dimensional depth-resolved Mueller matrix characterization of biological tissue by optical coherence tomography

We built a polarization-sensitive optical coherence tomographic system and measured the two-dimensional depth-resolved full 4 x 4 Mueller matrix of biological tissue for what is believed to be the first time. The Mueller matrix measurements, which we made by varying the polarization states of the light source and the detector, yielded a complete characterization of the polarization property of the tissue sample. The initial experimental results indicated that this new approach reveals some tissue structures that are not perceptible in standard optical coherence tomography.

[Morphological cure of cerebral arteriovenous malformations by endovascular therapeutics]

OBJECTIVE

To sum up the clinical characteristics and typical manifestation by analysing clinical materials from total embolized cerebral arteriovenous malformations (AVM) via endovascular embolization.

METHODS

We reviewed clinical and image materials of 50 patients whose cerebral AVM were embolized entirely and found the cerebral AVM morphological cure by endovascular embolization after studying the size, position, artery supply, therapeutics and follow-up.

RESULTS

50 patients with cerebral AVM were embolized by endovascular therapy, accounting for 17% of all patients. Malformation lesions were medium or small type, with a diameter less than 3 cm, 95% of them were located in the tentorium superior. Terminal end blood supply was common to AVM and especially medium cerebral artery (MCA) or its branches. 97% of the patients were graded III or below by spectzler grading system. 70% of them had a history of intracranial hemorrhage and were cured by one therapy.

CONCLUSIONS

It is a reliable and feasible method for morphological cure in cerebral AVM via endovascular therapeutics only, but case selection is important, that is, medium or small AVM with single branch terminal end blood supply in the tentorium superior.

Long-term efficacy of recombinant interferon alpha 2a in the treatment of chronic hepatitis C: a randomized prospective study comparing two dose schedules in Chinese patients

OBJECTIVE

To compare the long-term efficacy of a dose of 3 million units (MU) of r-IFN alpha 2a (IFN-alpha 2a) three times a week (t.i.w.) for 6 months with a starting dose 6 MU for 3 months and subsequent reduction to 3 MU t.i.w for further 3 months.

METHODS

Sixty-eight serological and histological chronic hepatitis C patients with elevated serum alanine aminotransferase (ALT) were enrolled and randomized into two groups. Sixty-three patients were completed with full course of treatment. Five patients were withdrawn from trial (2 due to personal reasons and 3 due to adverse drug reactions during treatment). Thirty patients received 6 MU IFN-alpha 2a t.i.w., 3 months followed by 3 MU t.i.w. for another 3 months (Group A). Thirty-three patients received 3 MU IFN-alpha 2a t.i.w. for 6 months (Group B).

RESULTS

The sex, age, baseline serum bilirubin, ALT and aspartate aminotransferase (AST) levels were matched in both groups. At the end of the 6th month, the complete and partial response rates in Group A were 60.0% and 16.7% respectively, and the clearance of serum HCV-RNA was 53.3%. In Group B, the complete and partial response rates were 72.7% and 6.1% respectively, and the clearance of HCV-RNA was 61.3%. The patients were followed up for 6, 12, and 18 months after stopping treatment. In Group A, the rates of complete normalization of ALT and clearance of serum HCV-RNA at 24 months were 50.0% and 60.0% respectively. In Group B, the rates of normalization of ALT and clearance of HCV-RNA at 24 months were 54.4% and 41.9% respectively. The efficacy between the two groups showed no statistically significant difference. The response rates of treatment were similar to those in the patients with HCV genotype 1b and 2a. Six patients (10.8% of the study population) developed neutralization antibodies to IFN-alpha 2a during treatment, and four of them were responded to the treatment. Adverse drug reactions (ADR), were common, but most of them were tolerable, and the incidence of ADR was in both groups, but the severity was higher in Group A.

CONCLUSIONS

IFN-alpha 2a is effective in the treatment of Chinese patients with chronic hepatitis C. The sustained response rates and adverse drug reactions among two dose schedule groups are similar.

[Spectroscopic characterization of a new terbium complex with red fluorescence]

Usually, the emission spectra of terbium complexes exhibit 490 nm, 545 nm bands (green color) under the excitation of UV light, which is ascribed to the two 5D4 - 7F6, 5D4 - 7F5 transition. In this report, pink red fluorescence under the excitation of 300-370nm UV light is observed for a new 1, 10-phenanthroline-2-naphthoate complex of terbium. The fluorescence, FT-IR, ICP and X-ray fluorescence analysis were performed. The results showed that under the perturbation of the ligands field, the probability of 5D4 - 7F3 transition of terbium ion was greatly enhanced, while the probability of 5D4 - 7F5 transition was greatly decreased in the complex. Therefore, pink-red fluorescence was observed for the title complex.

[The detection of serum hepatitis B virus Pre-S1 antigen and its relationship with HBeAg/anti-HBe and HBV DNA by polymerase chain reaction]

150 specimens were collected from chronic hepatitis patients, asymptomatic hepatitis B surface antigen (HBsAg) carriers and healthy individuals. Serum Pre-S1 and HBV markers were determined by enzyme immunoassay (EIA) and HBV DNA was tested by polymerase chain reaction (PCR). According to the results, specimens could be classified into five different groups: HBsAg and hepatitis e antigen (HBeAg) both positive; HBsAg positive and HBeAg/anti-HBe both negative; HBsAg and anti-HBe both positive with HBeAg negative; HBsAg negative with positive antibodies to s, c and e antigens; negative in all HBV markers. Each groups comprised 30 specimens respectively. The positive rate and relative titer (sample A value/cut-off value) of Pre-S1 Ag in HBeAg positive group (66.6%, 4.3250 +/- 2.2013, respectively) were markedly higher than those in HBeAg negative group (31.6%, 1.7863 +/- 0.6339, respectively, P<0.01). The detection rate of Pre-S1 Ag in these samples were 82% coincided with that of HBV DNA. The positive rate of Pre-S1 in the sera from five groups with different HB markers were well correlated to that of HBV DNA (r=0.9826, P<0.01). These results suggest that serum Pre-S1 detection can be used as a marker for the presence of the HBV genome and its quantitation will be correlated with the replication of virus.