Two years efficiency of lamivudine and adefovir dipivoxil combined therapy in chronic hepatitis B patients

BACKGROUND

Lamivudine (LAM) and adefovir (ADV) are widely used in most Asian countries, though monotherapy is associated with the occurrence of resistance.

AIM

To evaluate the efficiency of LAM and ADV combined treatment of chronic hepatitis B patients with compensated cirrhosis.

PATIENTS AND METHODS

206 eligible Chinese patients were randomly assigned in a 1:1 ratio to receive either LAM or ADV for the first 24 weeks. According to virologic response at 24 weeks, the patients either continued to monotherapy or switched to combined therapy for 48 weeks. After 48 weeks, all patients received LAM and ADV combined therapy for 96 weeks.

RESULTS

Serum HBV DNA levels significantly decreased in patients with ADV or LAM monotherapy and continuously reduced after the combined therapy. Serum ALT normalized rate were 88.24% and 81.37% at week 48, and 95.74% and 87.36% at week 96 in ADV and LAM group respectively, comparing to 60.78% and 56.73% in ADV and LAM groups at baseline. The accumulated virological breakthrough rate at week 48 and 96 was significantly higher in LAM group.

CONCLUSIONS

Both combination strategies were resulted in the long term virological, biochemical improvement in Chinese chronic hepatitis B patients with compensated cirrhosis.

Full electric control of exchange bias

We report the creation of a multiferroic field effect device with a BiFeO(3) (BFO) (antiferromagnetic-ferroelectric) gate dielectric and a La(0.7)Sr(0.3)MnO(3) (LSMO) (ferromagnetic) conducting channel that exhibits direct, bipolar electrical control of exchange bias. We show that exchange bias is reversibly switched between two stable states with opposite exchange bias polarities upon ferroelectric poling of the BFO. No field cooling, temperature cycling, or additional applied magnetic or electric field beyond the initial BFO polarization is needed for this bipolar modulation effect. Based on these results and the current understanding of exchange bias, we propose a model to explain the control of exchange bias. In this model the coupled antiferromagnetic-ferroelectric order in BFO along with the modulation of interfacial exchange interactions due to ionic displacement of Fe(3+) in BFO relative to Mn(3+/4+) in LSMO cause bipolar modulation.

Essential and unexpected role of Yin Yang 1 to promote mesodermal cardiac differentiation

RATIONALE

Cardiogenesis is regulated by a complex interplay between transcription factors. However, little is known about how these interactions regulate the transition from mesodermal precursors to cardiac progenitor cells (CPCs).

OBJECTIVE

To identify novel regulators of mesodermal cardiac lineage commitment.

METHODS AND RESULTS

We performed a bioinformatic-based transcription factor binding site analysis on upstream promoter regions of genes that are enriched in embryonic stem cell-derived CPCs. From 32 candidate transcription factors screened, we found that Yin Yang 1 (YY1), a repressor of sarcomeric gene expression, is present in CPCs in vivo. Interestingly, we uncovered the ability of YY1 to transcriptionally activate Nkx2.5, a key marker of early cardiogenic commitment. YY1 regulates Nkx2.5 expression via a 2.1-kb cardiac-specific enhancer as demonstrated by in vitro luciferase-based assays, in vivo chromatin immunoprecipitation, and genome-wide sequencing analysis. Furthermore, the ability of YY1 to activate Nkx2.5 expression depends on its cooperative interaction with Gata4 at a nearby chromatin. Cardiac mesoderm-specific loss-of-function of YY1 resulted in early embryonic lethality. This was corroborated in vitro by embryonic stem cell-based assays in which we showed that the overexpression of YY1 enhanced the cardiogenic differentiation of embryonic stem cells into CPCs.

CONCLUSIONS

These results demonstrate an essential and unexpected role for YY1 to promote cardiogenesis as a transcriptional activator of Nkx2.5 and other CPC-enriched genes.

Early cardiac development: a view from stem cells to embryos

From the 1920s, early cardiac development has been studied in chick and, later, in mouse embryos in order to understand the first cell fate decisions that drive specification and determination of the endocardium, myocardium, and epicardium. More recently, mouse and human embryonic stem cells (ESCs) have demonstrated faithful recapitulation of early cardiogenesis and have contributed significantly to this research over the past few decades. Derived almost 15 years ago, human ESCs have provided a unique developmental model for understanding the genetic and epigenetic regulation of early human cardiogenesis. Here, we review the biological concepts underlying cell fate decisions during early cardiogenesis in model organisms and ESCs. We draw upon both pioneering and recent studies and highlight the continued role for in vitro stem cells in cardiac developmental biology.

iPS cell modeling of cardiometabolic diseases

Cardiometabolic diseases encompass simple monogenic enzyme deficiencies with well-established pathogenesis and clinical outcomes to complex polygenic diseases such as the cardiometabolic syndrome. The limited availability of relevant human cell types such as cardiomyocytes has hampered our ability to adequately model and study pathways or drugs relevant to these diseases in the heart. The recent discovery of induced pluripotent stem (iPS) cell technology now offers a powerful opportunity to establish translational platforms for cardiac disease modeling, drug discovery, and pre-clinical testing. In this article, we discuss the excitement and challenges of modeling cardiometabolic diseases using iPS cell and their potential to revolutionize translational research.

Small molecule regulators of postnatal Nkx2.5 cardiomyoblast proliferation and differentiation

While recent data have supported the capacity for a neonatal heart to undergo cardiomyogenesis, it is unclear whether these new cardiomyocytes arise from an immature cardiomyoblast population or from the division of mature cardiomyocytes. By following the expression of enhanced Green Fluorescent Protein (eGFP) in an Nkx2.5 enhancer-eGFP transgenic mice, we have identified a population of immature cells that can undergo cardiomyogenic as well as smooth muscle cell differentiation in the neonatal heart. Here, we examined growth factors and small molecule regulators that potentially regulate the proliferation and cardiomyogenic versus smooth muscle cell differentiation of neonatal Nkx2.5-GFP⁺ cells in vitro. We found that A83-01 (A83), an inhibitor of TGF-βRI, was able to induce an expansion of neonatal Nkx2.5-eGFP⁺ cells. In addition, the ability of A83 to expand eGFP⁺ cells in culture was dependent on signalling from the mitogen-activated protein kinase kinase (MEK) as treatment with a MEK inhibitor, PD0325901, abolished this effect. On the other hand, activation of neonatal Nkx2.5-eGFP⁺ cells with TGF-β1, but not activin A nor BMP2, led to smooth muscle cell differentiation, an effect that can be reversed by treatment with A83. In summary, small molecule inhibition of TGF-β signalling may be a promising strategy to induce the expansion of a rare population of postnatal cardiomyoblasts.

Inefficient reprogramming of fibroblasts into cardiomyocytes using Gata4, Mef2c, and Tbx5

RATIONALE

Direct reprogramming of fibroblasts into cardiomyocytes is a novel strategy for cardiac regeneration. However, the key determinants involved in this process are unknown.

OBJECTIVE

To assess the efficiency of direct fibroblast reprogramming via viral overexpression of GATA4, Mef2c, and Tbx5 (GMT).

METHODS AND RESULTS

We induced GMT overexpression in murine tail tip fibroblasts (TTFs) and cardiac fibroblasts (CFs) from multiple lines of transgenic mice carrying different cardiomyocyte lineage reporters. We found that the induction of GMT overexpression in TTFs and CFs is inefficient at inducing molecular and electrophysiological phenotypes of mature cardiomyocytes. In addition, transplantation of GMT infected CFs into injured mouse hearts resulted in decreased cell survival with minimal induction of cardiomyocyte genes.

CONCLUSIONS

Significant challenges remain in our ability to convert fibroblasts into cardiomyocyte-like cells and a greater understanding of cardiovascular epigenetics is needed to increase the translational potential of this strategy.

Reprogramming of mouse, rat, pig, and human fibroblasts into iPS cells

The induction of pluripotency in somatic cells by transcription-factor overexpression has been widely regarded as one of the major breakthroughs in stem cell biology within this decade. The generation of these induced pluripotent stem cells (iPSCs) has enabled investigators to develop in vitro disease models for biological discovery and drug screening, and in the future, patient-specific therapy for tissue or organ regeneration. While new technologies for reprogramming are continually being discovered, the availability of iPSCs from different species is also increasing rapidly. Comparison of iPSCs across species may provide new insights into key aspects of pluripotency and early embryonic development. iPSCs from large animals may enable the generation of genetically modified large animal models or potentially transplantable donor tissues or organs. This unit describes the procedure for the generation of iPSCs from mouse, rat, pig and human fibroblasts.

Epigenetic mechanisms in cardiac development and disease

During mammalian development, cardiac specification and ultimately lineage commitment to a specific cardiac cell type is accomplished by the action of specific transcription factors (TFs) and their meticulous control on an epigenetic level. In this review, we detail how cardiac-specific TFs function in concert with nucleosome remodeling and histone-modifying enzymes to regulate a diverse network of genes required for processes such as cell growth and proliferation, or epithelial to mesenchymal transition (EMT), for instance. We provide examples of how several cardiac TFs, such as Nkx2.5, WHSC1, Tbx5, and Tbx1, which are associated with developmental and congenital heart defects, are required for the recruitment of histone modifiers, such as Jarid2, p300, and Ash2l, and components of ATP-dependent remodeling enzymes like Brg1, Baf60c, and Baf180. Binding of these TFs to their respective sites at cardiac genes coincides with a distinct pattern of histone marks, indicating that the precise regulation of cardiac gene networks is orchestrated by interactions between TFs and epigenetic modifiers. Furthermore, we speculate that an epigenetic signature, comprised of TF occupancy, histone modifications, and overall chromatin organization, is an underlying mechanism that governs cardiac morphogenesis and disease.

Induced pluripotent stem cell modeling of complex genetic diseases

The study of complex disease genetics by genome-wide association studies (GWAS) has led to hundreds of genomic loci associated with disease traits in humans. However, the functional consequences of most loci are largely undefined. We discuss here the potential for human induced pluripotent stem (iPS) cells to bridge the gap between genetic variant and mechanisms of complex disease. We also highlight specific diseases and the roadblocks that must be overcome before iPS cell technology can be widely adopted for complex disease modeling.

Harnessing the potential of induced pluripotent stem cells for regenerative medicine

The discovery of methods to convert somatic cells into induced pluripotent stem cells (iPSCs) through expression of a small combination of transcription factors has raised the possibility of producing custom-tailored cells for the study and treatment of numerous diseases. Indeed, iPSCs have already been derived from patients suffering from a large variety of disorders. Here we review recent progress that has been made in establishing iPSC-based disease models, discuss associated technical and biological challenges, and highlight possible solutions to overcome these barriers. We believe that a better understanding of the molecular basis of pluripotency, cellular reprogramming and lineage-specific differentiation of iPSCs is necessary for progress in regenerative medicine.

Developmental and regenerative biology of multipotent cardiovascular progenitor cells

Our limited ability to improve the survival of patients with heart failure is attributable, in part, to the inability of the mammalian heart to meaningfully regenerate itself. The recent identification of distinct families of multipotent cardiovascular progenitor cells from endogenous, as well as exogenous, sources, such as embryonic and induced pluripotent stem cells, has raised much hope that therapeutic manipulation of these cells may lead to regression of many forms of cardiovascular disease. Although the exact source and cell type remains to be clarified, our greater understanding of the scientific underpinning behind developmental cardiovascular progenitor cell biology has helped to clarify the origin and properties of diverse cells with putative cardiogenic potential. In this review, we highlight recent advances in the understanding of cardiovascular progenitor cell biology from embryogenesis to adulthood and their implications for therapeutic cardiac regeneration. We believe that a detailed understanding of cardiogenesis will inform future applications of cardiovascular progenitor cells in heart failure therapy and regenerative medicine.

Isolation and functional characterization of pluripotent stem cell-derived cardiac progenitor cells

The use of transgenic markers in pluripotent stem cells allows the facile isolation of transient cell populations that appear at certain phases of embryonic development. Here, we describe a procedure for deriving cardiac progenitors from mouse pluripotent stem cells carrying a GFP reporter under the control of an Nkx2.5 enhancer sequence. The cells are propagated under standard conditions and are differentiated using the hanging-droplet method with medium optimized for commitment to the cardiac lineage. Cardiac progenitors are isolated from the differentiation culture using fluorescence-activated cell sorting (FACS) and can be cultured further for functional characterization and experimentation. The protocols described here can be applied to both embryonic and induced pluripotent stem cells and can easily be adapted to transgenic lines carrying other cardiac cell lineage reporters.

Origin of cardiac progenitor cells in the developing and postnatal heart

The mammalian heart lacks the capacity to replace the large numbers of cardiomyocytes lost due to cardiac injury. Several different cell-based routes to myocardial regeneration have been explored, including transplantation of cardiac progenitors and cardiomyocytes into injured myocardium. As seen with cell-based therapies in other solid organ systems, inherent limitations, such as host immune response, cell death and long-term graft instability have hampered meaningful cardiac regeneration. An understanding of the cell biology of cardiac progenitors, including their developmental origin, lineage markers, renewal pathways, differentiation triggers, microenvironmental niche, and mechanisms of homing and migration to the site of injury, will enable further refinement of therapeutic strategies to enhance clinically meaningful cardiac repair.

Reversible electric control of exchange bias in a multiferroic field-effect device

Electric-field control of magnetization has many potential applications in magnetic memory storage, sensors and spintronics. One approach to obtain this control is through multiferroic materials. Instead of using direct coupling between ferroelectric and ferromagnetic order parameters in a single-phase multiferroic material, which only shows a weak magnetoelectric effect, a unique method using indirect coupling through an intermediate antiferromagnetic order parameter can be used. In this article, we demonstrate electrical control of exchange bias using a field-effect device employing multiferroic (ferroelectric/antiferromagnetic) BiFeO(3) as the dielectric and ferromagnetic La(0.7)Sr(0.3)MnO(3) as the conducting channel; we can reversibly switch between two distinct exchange-bias states by switching the ferroelectric polarization of BiFeO(3). This is an important step towards controlling magnetization with electric fields, which may enable a new class of electrically controllable spintronic devices and provide a new basis for producing electrically controllable spin-polarized currents.

Promises and pitfalls in cell replacement therapy for heart failure

Symptomatic heart failure is a complex clinical syndrome with a poor prognosis. Many efforts have been made to develop new therapeutic strategies to improve prognosis associated with heart failure. In this context, different stem cell populations for cardiac regenerative therapy have been examined recently. Here we discuss the potential strategies for using stem cells in cardiac regenerative therapy and the barriers that remain before an effective cell-based cardiac regenerative therapy can be employed clinically.

The integrative aspects of cardiac physiology and their implications for cell-based therapy

Cardiac development is characterized by a complex interplay of chemical, mechanical, and electrical forces, which together contribute to the proper formation of the heart muscle. In adult myocardium, cardiomyocytes are elongated, well-coupled by gap junctions, and organized in spatially well-defined muscle fibers. This specific tissue architecture affects electromechanical activation and global cardiac function. Since the adult heart has only limited capacity for repair after injury, a significant loss of myocardial tissue often leads to impaired cardiac function. Recent efforts to transplant autologous cells to counteract this cardiomyocyte loss have resulted in marginal functional improvement and no evidence of myocyte regeneration. In order to achieve durable therapeutic efficiency, the transplanted cells will need to not only be cardiomyogenic, but also functionally integrate with host myocardial tissue and thereby contribute to both structural and functional restoration.

Generation of functional ventricular heart muscle from mouse ventricular progenitor cells

The mammalian heart is formed from distinct sets of first and second heart field (FHF and SHF, respectively) progenitors. Although multipotent progenitors have previously been shown to give rise to cardiomyocytes, smooth muscle, and endothelial cells, the mechanism governing the generation of large numbers of differentiated progeny remains poorly understood. We have employed a two-colored fluorescent reporter system to isolate FHF and SHF progenitors from developing mouse embryos and embryonic stem cells. Genome-wide profiling of coding and noncoding transcripts revealed distinct molecular signatures of these progenitor populations. We further identify a committed ventricular progenitor cell in the Islet 1 lineage that is capable of limited in vitro expansion, differentiation, and assembly into functional ventricular muscle tissue, representing a combination of tissue engineering and stem cell biology.

Platypnea-Orthodeoxia Syndrome in Two Previously Healthy Adults: A Case-based Review

We describe here the clinical manifestations of platypnea-orthodeoxia in two patients with interatrial shunting. In both cases, the patients were asymptomatic prior to developing additional cardiopulmonary issues that apparently enhanced right-to-left intracardiac shunting. The patients were both treated with percutaneously deployed occlusion devices, with excellent results. Symptoms and positional oxygen desaturation resolved after device placement in both cases. In addition, these patients remain symptom-free 30 months after device implantation.

Preparation, characterization, and anti-tumor property of podophyllotoxin-loaded solid lipid nanoparticles

In an effort to develop an alternative formulation of podophyllotoxin suitable for drug release and delivery, podophyllotoxin-loaded solid lipid nanoparticles (PPT-SLNs) were constructed, characterized and examined for in vitro cytotoxicity and tumor inhibition. The SLNs were prepared by using a solvent emulsification-evaporation method, and their size was around 50 nm. TEM detection showed that the SLNs were homogeneous and spherical in shape, and differential scanning calorimetry (DSC) measurement revealed a new conformation of PPT-SLNs. An in vitro drug release study showed that PPT was released from the SLNs in a slow but time-dependent manner. Furthermore, the treatment of 293T and HeLa cells with PPT-SLNs demonstrated that PPT-SLNs were less toxic to normal cells and more effective in anti-tumor potency compared with unconjugated PPT. A colony forming efficiency assay showed an effective long-term cancer growth suppression of PPT-SLNs; in addition, they can also enhance the apoptotic and cellular uptake processes on tumor cells compared with PPT. These results collectively demonstrated that this SLN formulation has a potential application as an alternative delivery system for anti-tumor drugs.

A new method for CE-EC determination of mercaptopurine (MP) in a PMMA biochip with on-chip gold nano-electrode ensemble (GNEE) working and decouple electrodes

This paper presents a new method for CE-EC determination of Mercaptopurine (MP), one of the most important medicines for inflammatory bowel disease (IBD) and acute lymphoblastic leukemia (ALL) treatment, in a PMMA-based microfluidic chip. A simple and reliable process for preparing the template of gold nanoelectrode ensemble (GNEE) and fabricating the integrated microfluidic chip is reported in the present study. The use of GNEE electrodes for both electric current decoupling and signal sensing in the proposed CE-EC chip not only enhances the signal response but also decreases the background noise during detection. Results show that a good detection limit of 100 nM for detecting mercaptopurine is achieved with the proposed method. In addition, the measured results also shows a good linear response between the detected CE-EC signals and the concentration of MP within the range of 100 nM-10 mM (R2 = 0.989). The proposed microchip device provides a novel and fast detection method for mercaptopurine analysis.

Cardiovascular Stem Cells in Regenerative Medicine: Ready for Prime Time?

Restoration of cardiovascular function is the ultimate goal of stem cell-based therapy. In principle, cardiovascular stem cells can improve cardiac function via de novo cardiomyogenesis, enhanced myocardial neovascularization, and prevention of post-infarct remodeling. Stem cell transplantation to improve cardiac function has received mixed results in human clinical trials. These early data suggest that a critical reassessment of the scientific basis to stem cell-based therapy is needed in order to bring this highly promising treatment modality to mainstream clinical care.

The effects of maternal Cd on the metallothionein expression in tilapia (Oreochromis mossambicus) embryos and larvae

The purpose of this study was to identify the factor(s) which would enhance the Cd resistance as assessed by the metallothionein (MT) expression in tilapia larvae. Larvae were collected from parents that were pretreated respectively with Cd or saline. At the end of the 12-week experiment, the hepatic MT and Cd contents in the breeding female fish were recorded. Our results indicated that a significant relationship between Cd and MT contents can be found in the offspring from the parent fish treated with Cd. However, the higher Cd resistance, Cd contents, and MT expression were limited to those larvae from parent fish bred within 4 weeks of the injection. By week 12, the Cd-treated fish still contained high levels of MT in their hepatic tissues. However, the MT and Cd contents in the larvae from these adult fish were not significantly different from those from the controls. In summary, we suggest that the higher Cd resistance of larvae from the egg stage was a result of the Cd contamination of the parent female, as evidenced by an increase in MT expression induced in tilapia embryos and larvae.

Origins and fates of cardiovascular progenitor cells

Multipotent cardiac progenitor cells are found in the fetal and adult heart of many mammalian species including humans and form as intermediates during the differentiation of embryonic stem cells. Despite similar biological properties, the molecular identities of these different cardiac progenitor cell populations appear to be distinct. Elucidating the origins and lineage relationships of these cell populations will accelerate clinical applications such as drug screening and cell therapy as well as shedding light on the pathogenic mechanisms underlying cardiac diseases.

Multipotent stem cells in cardiac regenerative therapy

The potential for stem cells to ameliorate or cure heart diseases has galvanized a cadre of cardiovascular translational and clinical scientists to take a 'first-in-man' approach using autologous stem cells from a variety of tissues. However, recent clinical trial data show that when these cells are given by intracoronary infusion or direct myocardial injection, limited improvement in heart function occurs with no evidence of cardiomyogenesis. These studies illustrate the great need to understand the logic of cell-lineage commitment and the principles of cardiac differentiation. Recent identification of stem/progenitor cells of embryological origin with intrinsic competence to differentiate into multiple lineages within the heart offers new possibilities for cardiac regeneration. When combined with developments in nuclear reprogramming and provided that tumor risks and other challenges of embryonic cell transplantation can be overcome, the prospect of achieving autologous, cardiomyogenic, stem cell-based therapy may be within reach.

Selection of a phage-displayed peptide recognized by monoclonal antibody directed blocking the site of hepatitis C virus E2 for human CD81

The human CD81 (hCD81) molecule has been identified as a putative receptor for hepatitis C virus (HCV). HCV envelope glycoprotein 2 (E2) most likely plays a pivotal role in binding to host cells by interacting with the hCD81 molecule. In this study, a phage-displayed peptide library was used to select small peptides with anti-hCD81 monoclonal antibody JS-81. The output/input ratio of phages increased about 91 fold after the third round of selection. Eight of the 30 phage clones selected from the phage library showed specific binding to the anti-hCD81 by enzyme linked immunosorbent assay (ELISA). Competitive inhibition test further demonstrated that HCV E2 could significantly inhibit the binding of a positive phage clone to anti-hCD81 JS-81. Exogenous small peptide ATWVCGPCT contained by the positive phage clones showed aligned with the hCD81 sequence from 153-161 by sequence analyses. These results suggest that the selected ATWVCGPCT is a novel hCD81-like small peptide, which can block the binding site of HCV E2 for hCD81. It may be of further application on development of antiviral agents targeting the stage of HCV entry.

Effects of Ca2+ or Na+ on metallothionein expression in tilapia larvae (Oreochromis mossambicus) exposed to cadmium or copper

The objectives of this study were to try to determine the reasons of the external Ca(2+) and Na(+) enhancement of Cd(2+) and Cu(2+) resistance in fish. Tilapia larvae at 3 days posthatch were exposed to (A) 0 (control), 40 microg/L Cd(2+), 40 microg/L Cd(2+) + 2 mM Ca(2+) (Cd/hyper-Ca), and 2 mM Ca(2+) or (B) 0 (control), 75 microg/L Cu(2+), 75 microg/L Cu(2+) + 0.52 mM Na(+) (Cu/hyper-Na), and 0.52 mM Na(+). After 48 hours, results indicated that (1) Cd/hyper-Ca and Cu/hyper-Na treatments showed decreased growth inhibition induced by the metals; (2) metal accumulation in Cd/hyper-Ca-treated larvae was lower compared with those exposed only to Cd; and (3) metallothionein (MT) expression was significantly higher in Cu/hyper-Na-treated larvae than in the group treated with Cu only. Taking all of this into account, either supplementary Ca(2+) or Na(+) in ambient water may help fish to maintain Ca(2+) or Na(+) homeostasis, which could decrease metal accumulation and its detrimental effects. Consequently, the fish increase MT expression and retard the growth inhibition caused by metals.

Developmental origin of a bipotential myocardial and smooth muscle cell precursor in the mammalian heart

Despite recent advances in delineating the mechanisms involved in cardiogenesis, cellular lineage specification remains incompletely understood. To explore the relationship between developmental fate and potential, we isolated a cardiac-specific Nkx2.5(+) cell population from the developing mouse embryo. The majority of these cells differentiated into cardiomyocytes and conduction system cells. Some, surprisingly, adopted a smooth muscle fate. To address the clonal origin of these lineages, we isolated Nkx2.5(+) cells from in vitro differentiated murine embryonic stem cells and found approximately 28% of these cells expressed c-kit. These c-kit(+) cells possessed the capacity for long-term in vitro expansion and differentiation into both cardiomyocytes and smooth muscle cells from a single cell. We confirmed these findings by isolating c-kit(+)Nkx2.5(+) cells from mouse embryos and demonstrated their capacity for bipotential differentiation in vivo. Taken together, these results support the existence of a common precursor for cardiovascular lineages in the mammalian heart.

Standard treatment for Helicobacter pylori infection is suboptimal in non-ulcer dyspepsia compared with duodenal ulcer in Chinese

BACKGROUND

Recent studies suggest that the Helicobacter pylori eradication rate in patients with non-ulcer dyspepsia is lower when compared to patients with peptic ulcer diseases.

AIM

The aim of this study was to study the efficacy of triple therapy for H. pylori infection in patients with duodenal ulcer vs. patients with non-ulcer dyspepsia.

METHODS

A total of 582 Chinese patients with proven H. pylori infection were recruited to receive: omeprazole 20 mg, amoxicillin 1000 mg and clarithromycin 500 mg all given twice daily for 7 days (OCA regime). Endoscopy with rapid urease test, histology and culture were performed before treatment. Post-treatment H. pylori status was determined by (13)C-urea breath test. Metronidazole, clarithromycin and amoxicillin resistance was defined as minimum inhibitory concentration (MIC) of >8 microg/mL, >1 microg/mL and >1 microg/mL, respectively.

RESULTS

A significantly higher (intention-to-treat/per-protocol) eradication rate was found in patients with duodenal ulcer than those with non-ulcer dyspepsia (91/94% vs. 84/88% respectively, P = 0.011 and P = 0.016). Clarithromycin resistance rate was higher in patients with non-ulcer dyspepsia than those with duodenal ulcer (14% vs. 6%, P = 0.015). Clarithromycin resistance (40% vs. 5%, P < 0.001, OR 12, 95% CI: 5.7-24.3) and the diagnosis of non-ulcer dyspepsia (91% vs. 84%, P = 0.011, OR 2.0, 95% CI: 1.2-3.3) significantly affected the success of H. pylori eradication.

CONCLUSION

Clarithromycin resistance accounts for the significantly lower and suboptimal H. pylori eradication rate of OCA regimen in Chinese patients with non-ulcer dyspepsia compared to those with duodenal ulcer.

Family size, miscarriage-proneness, and handedness: tests of hypotheses of the developmental instability theory of handedness

The handedness theory of Yeo and Gangestad (1993) posits that moderate right-handedness is the modal manifestation of genetic handedness and that ''developmental instability'' produces deviations from modal handedness. It is also suggested (1) that sinistral parents may produce fewer offspring than do dextral parents; and (2) that sinistral mothers may be more prone to miscarriages than are dextral mothers. In line with these hypotheses, Gangestad et al. (1996) reported that a human leukocyte antigen (B8) was related to both left-handedness and to reduced offspring number in their study. They also found that left-handedness was related to the human leukocyte antigen DR3, and Yeo and Gangestad (1998) noted that this antigen has been found by Christiansen et al. (1996) to be associated with an increased risk of spontaneous abortion in women. We assessed the first hypothesis through a study of the family sizes of 2083 families with two right-handed parents and 502 families having one or more left-handed parents; we assessed the second hypothesis from miscarriage history data supplied by 300 dextral and 52 sinistral mothers. Results supported the developmental instability theory with respect to the hypothesis regarding family size, but not with respect to the hypothesis regarding miscarriage-proneness.

Naturopathic and Western herbal medicine practice in Australia-a workforce survey

BACKGROUND

Despite substantial growth in the use of complementary medicine, no comprehensive national study has been undertaken of the naturopathic and Western herbal medicine component of the healthcare workforce in Australia. This study aimed to examine the nature of these practices and this currently unregulated workforce in Australia.

METHODS

A comprehensive survey questionnaire was developed in consultation with the profession and distributed nationally to all members of the naturopathic and Western herbal medicine workforce.

RESULTS

The practices of herbal medicine and naturopathy make up a sizeable component of the Australian healthcare sector, with approximately 1.9 million consultations annually and an estimated turnover of $AUD 85 million in consultations (excluding the cost of medicines). A large proportion of patients are referred to practitioners by word of mouth. Up to one third of practitioners work in multidisciplinary clinics with other registered sectors of the healthcare community. The number of adverse events associated with herbal medicines, nutritional substances and homoeopathic medicines recorded in Australia is substantial and the types of events reported are not trivial. Data suggest that practitioners will experience one adverse event every 11 months of full-time practice, with 2.3 adverse events for every 1000 consultations (excluding mild gastrointestinal effects).

CONCLUSION

These data confirm the considerable degree of utilisation of naturopathic and Western herbal medicine practitioners by the Australian public. However, there is a need to examine whether statutory regulation of practitioners of naturopathy and Western herbal medicine is required to better protect the public.

Effects of copper sulfate on ion balance and growth in tilapia larvae (Oreochromis mossambicus)

Newly hatched tilapia larvae were exposed to sublethal concentrations of Cu2+ (0, 30, 50, and 100 microg/L) and lethal concentrations of Cu2+ (200 and 400 microg/L) for 24-96 h. The interaction of the exposure dose and time was related to the Cu2+ accumulation rate, which showed a higher accumulation rate with sublethal concentrations of Cu2+ within 24 h compared to the other treatments. Furthermore, Cu2+ contents in the whole body of larvae significantly increased following Cu2+ exposure times up to 96 h. Cu2+ in the medium produced a dose-response effect on Na+ and K+ contents in larvae after 96 h of exposure time. Changes in Ca2+ contents statistically significantly decreased and were shown to be dose-responsive for larval exposure times exceeding 72 h. Changes of Ca2+ contents were more sensitive than those of Na+ and K+ with Cu2+ treatment of early larvae. Notably Na+ and K+ contents showed significant increases of 17-23% in larvae exposed to low concentrations of Cu2+ (30-50 microg/L) for 24-72 h as compared to control larvae. Cu2+ caused no significant effect on body Cl- content or osmolality except at 100 microg/L Cu2+ for 24 h in tilapia larvae as compared to the control. However, there was a restoration phenomenon in larvae exposed to 100 microg/L Cu2+ for longer than 72 h. The water content of larvae exposed to Cu2+ for 96 h significantly decreased. The yolk absorption rate of tilapia larvae was significantly suppressed when they were exposed to Cu2+ medium containing 30, 50, 100, 200, or 400 Cu2+ microg/L from 72 h post transfer. These results obviously show that larvae are sensitive to Cu2+ during early development.

Protoporphyrin IX production and its photodynamic effects on glioma cells, neuroblastoma cells and normal cerebellar granule cells in vitro with 5-aminolevulinic acid and its hexylester

5-Aminolevulinic acid (ALA) has shown promising in photodynamic detection and therapy of brain tumor. However, the knowledge on selective accumulation of ALA-induced protoporphyrin IX (PpIX) in brain tumor tissue is still fragment. In the present study, the rat C6 glioma cells, human SK-N-SH neuroblastoma cells, and rat normal cerebellar granule cells (RCG) were used to investigate the PpIX production and photocytotoxicity in vitro. The C6 cells and SK-N-SH cells showed a similar kinetics of PpIX accumulation after exposure to ALA or ALA hexyl ester (ALA-H), with an initial increase up to 6-8 h and then saturated. In the case of RCG cells, the PpIX accumulation slowly increased until 12 h studied. However the cellular PpIX content was more than 10 times higher in the C6 and SK-N-SH cells than that in the normal RCG cells. The intracellular localization of PpIX measured by cofocal laser scanning microscopy was in same pattern in the C6 glioma cells and RCG normal cells with a diffuse cytoplasm distribution. The sensitivity of the C6 cells and SK-N-SH cells to ALA or ALA-H PDT was similar. It appears that ALA-H could achieve similar or slightly better results than ALA with respect to PpIX production and photoinactivation of cells, although a 10 times lower concentration of ALA-H was used.

Identification and expression of human CD81 gene on murine NIH/3T3 cell membrane

The human CD81 (hCD81) molecule has been identified as a putative receptor for hepatitis C virus (HCV). In this study, eukaryotic expression vector pCDM8-hCD81 containing hCD81 cDNA and pSV2neo helper plasmid was used to cotransfect with lipofectamine into murine fibroblast cell line NIH/3T3 to establish an hCD81-expressing cell line. Resistant cell clones were obtained 20 days after the selection with neomycin (600 micro/ml) and then cultured as monoclones. The expression of the transfected hCD81 gene in the cells was verified by RT-PCR and flow cytometry analyses. One of the selected cell clones showed obvious expression of hCD81 and was named NIH/3T3-hCD81. Competitive inhibition tests indicated that the binding of monoclonal anti-hCD81 (JS-81) to NIH/3T3-hCD81 cells was inhibited by recombinant HCV E2 protein, suggesting that the expressed hCD81 molecules on NIH/3T3-hCD81 cells maintain natural conformation of binding to HCV E2. The transfected NIH/3T3-hCD81 cells should be of great potential value in studies on HCV attachment and onset of infection.

Non-invasive assessment of arterial distension waveforms using gradient-based hough transform and power Doppler ultrasound imaging

The peripheral arterial vessel often appears as an elliptic shape under the constraints of the surrounding tissues. In this study, the gradient-based Hough transform was used to detect the central location of the ellipse and the lumen area of the arterial vessel non-invasively using power Doppler imaging. Sequential ultrasound images were used to construct arterial distension waveforms in both the major- and minor-axis directions for a few cardiac cycles. The common carotid arteries (CCAs) for nine healthy male volunteers (mean age 24 years), in the sitting position, were investigated in vivo. The CCAs (n = 9) had a mean diameter of 5.83mm, and the pulsatile diameter distension was 13.7+/-1.9%. The brachial artery and dorsalis pedis artery for five healthy male volunteers (mean age 26 years), in the supine position, had mean diameters of 4.03mm and 2.83mm and distensions of 16.7+/-4.6% and 15.5+/-5.4%, respectively. The movement of the arterial centre location during the cardiac cycle reflected the asymmetry of the reaction forces produced by the surrounding soft tissues. The present method can obtain the response of vessel distension to pulse pressure, as well as the constrained conditions of the arteries.

Spectrum of mutations of the AAAS gene in Allgrove syndrome: lack of mutations in six kindreds with isolated resistance to corticotropin

Familial glucocorticoid deficiency due to corticotropin (ACTH) resistance consists of two distinct genetic syndromes that are both inherited as autosomal recessive traits: isolated ACTH resistance (iACTHR), which may be caused by inactivating mutations of the ACTH receptor (the MC2R gene) or mutations in an as yet unknown gene(s), and Allgrove syndrome (AS). The latter is also known as triple-A syndrome (MIM 231550). In three large cohorts of AS kindreds, the disease has been mapped to chromosome 12; most recently, mutations in the AAAS gene on 12q13 were found in these AS families. AAAS codes for the WD-repeat containing ALADIN (for alacrima-achalasia-adrenal insufficiency-neurologic disorder) protein. We investigated families with iACTHR (n = 4) and AS (n = 6) and a Bedouin family with ACTHR and a known defect of the TSH receptor. Four AS families were of mixed extraction from Puerto Rico (PR); most of the remaining six families were Caucasian families from North America (NA). Sequencing analysis found no MC2R genetic defects in any of the kindreds. No iACTHR kindreds, but all of AS families, had AAAS mutations. The previously reported IVS14+1G-->A splice donor mutation was found in all PR families, apparently due to a founder effect; one NA kindred was heterozygous for this mutation. In the latter family, long-range PCR failed to identify a deletion or other rearrangements of the AAAS gene. No other heterozygote or transmitting parent had any phenotype that could be considered part of AS. The IVS14+1G-->A mutation results in a premature termination of the predicted protein; although it was present in all PR families (in the homozygote state in three of them), there was substantial clinical variation between them. One PR family also carried a novel splice donor mutation of the AAAS gene in exon 11, IVS11+1G-->A; the proband was a compound heterozygote. A novel point mutation, 43C-->A(Gln15Lys), in exon 1 of the AAAS gene was identified in the homozygote state in a Canadian AS kindred with a milder AS phenotype. The predicted amino acid substitution in this family is located in a sequence that may participate in the preservation of stability of ALADIN beta-strands, whereas the splicing mutation in exon 11 may interfere with the formation of WD repeats in this molecule. We conclude that 1) AAAS does not appear to be frequently mutated in families with iACTHR; 2) AAAS is mutated in AS families from PR (that had previously been mapped to 12q13) and NA; and, 3) there is significant clinical variability between patients with the same AAAS defect.

AMPA-preferring receptors mediate excitatory non-NMDA responses of primate retinal ganglion cells

Glutamate and kainate-induced currents of primate ganglion cells were studied using the whole-cell patch-clamp technique in a retinal slice preparation. Antagonists and allosteric modulators of desensitization selective for either alpha-amino-3-hydroxy-5-methyl-4-isoazoleprionic acid (AMPA)- or kainate-preferring receptors were used to determine the contributions of each type of receptor to excitatory responses. With synaptic transmission and NMDA receptors blocked, the AMPA-preferring receptor antagonist GYKI 52466 (30 microM-100 microM) reversibly blocked most of the glutamate-induced current in ganglion cells. GYKI 52466 also blocked the response in ganglion cells to focally applied kainate, suggesting that the current response to kainate arises from activation of AMPA-preferring receptors, and not kainate-preferring receptors. Both cyclothiazide (10 microM-100 microM) and the novel drug 4-[2-(phenylsulfonylamino)ethylthio]-2,6-difluoro-phenoxyacetamide (PEPA, 20 microM-100 microM), which selectively enhance responses mediated by AMPA-preferring receptors, enhanced glutamate-induced responses of ganglion cells. Since these drugs preferentially inhibit desensitization of the flip and flop splice variants, respectively, of AMPA-preferring receptors, it is likely that both splice variants are present on these ganglion cells. Concanavalin A, which selectively suppresses the desensitization of kainate-preferring receptors, had no effect on the glutamate-induced responses of ganglion cells. We conclude that the non-NMDA component of the excitatory, glutamatergic input to primate ganglion cells is mediated largely by AMPA-preferring receptors, with little, if any, kainate-preferring receptor-mediated response.

Head-column field-amplified sample stacking in capillary electrophoresis for the determination of cimetidine, famotidine, nizatidine, and ranitidine-HCl in plasma

In this study, low concentrations of histamine2-receptor (H2-)antagonists were effected across a water plug, with separation taking place in a binary buffer comprising ethylene glycol and NaH2PO4 (pH 5.0), and detection at 214 nm. Liquid-liquid extraction with ethyl acetate- isopropanol is shown to provide extracts that are sufficiently clean. The calibration curves were linear over a concentration range of 0.1-2.00 microg/mL cimetidine, 0.2-5.0 microg/mL ranitidine-HCl, 0.3-5.0 microg/mL nizatidine, and 0.1-3.0 microg/mL famotidine. Mean recoveries were > 82%, while the intra- and interday relative standard deviations (RSDs) and relative errors (REs) were all < 13%. The method is sensitive with a detection limit of 3 ng/mL cimetidine, 30 ng/mL ranitidine HCl, 50 ng/mL nizatidine and 10 ng/mL famotidine (S/N = 3, electric-driven injection 90 s). This newly developed capillary electrophoresis (CE) method was applied for the determination of analytes extracted from plasma taken from a volunteer dosing a cimetidine, ranitidine, and nizatidine tablet simultaneously. These three H2-antagonists can be detected in real samples by this method, excluding the low dosing of famotidine tablet.

Simultaneous determination of cimetidine, famotidine, nizatidine, and ranitidine in tablets by capillary zone electrophoresis

A simple capillary zone electrophoresis (CZE) method is described for the simultaneous determination of cimetidine (CIM), famotidine (FAM), nizatidine (NIZ), and ranitidine (RAN). The analysis of these drugs was performed in a 100 mM phosphate buffer, pH 3.5. Several parameters were studied, including wavelength for detection, concentration and pH of phosphate buffer, and separation voltage. The quantitative ranges were 100-1,000 microM for each analyte. The intra- and interday relative standard deviations (n = 5) were all less than 4%. The detection limits were found to be about 10 microM for CIM, 20 microM for RAN, 20 microM for NIZ, and 10 microM for FAM (S/N = 3, injection 1 s) at 214 nm. All recoveries were greater than 92%. Applications of the method to the assay of these drugs in tablets proved to be feasible.

alpha(2)-Macroglobulin from rheumatoid arthritis synovial fluid: functional analysis defines a role for oxidation in inflammation

A hallmark of inflammation is the release of oxidants, proteinases, and cytokines, all important mediators of the inflammatory cascade. alpha(2)-Macroglobulin (alpha(2)M) is a high-affinity, broad-specificity proteinase inhibitor that also binds and regulates the biological activities of a number of cytokines. We demonstrated recently that hypochlorite-oxidized alpha(2)M has decreased ability to inhibit proteinases and regulate cytokines in vitro. The role of oxidation in regulating alpha(2)M functions in vivo is largely unknown. To determine the extent and biological consequence of in vivo alpha(2)M oxidation, we measured the degree of oxidative alpha(2)M modification from rheumatoid arthritis (RA) synovial fluid and compared this with osteoarthritis (OA) as noninflammatory controls. We found that RA synovial fluid alpha(2)M is significantly more oxidized than that from OA. RA synovial fluid also contains a twofold higher median alpha(2)M level than OA, while having only half the alpha(2)M-proteinase inhibitory activity. Detailed biochemical analysis demonstrates proteolytically degraded alpha(2)M in RA greater than in OA synovial fluid. Additionally, the hypochlorite-mediated oxidation product, chlorotyrosine, is present in RA more than in OA or plasma alpha(2)M samples. Taken together, these findings confirm a role for oxidative regulation of inflammation by altering the functions of extracellular mediators such as alpha(2)M.

Differential regulation of the fibroblast growth factor (FGF) family by alpha(2)-macroglobulin: evidence for selective modulation of FGF-2-induced angiogenesis

The fibroblast growth factor (FGF) family has an important role in processes such as angiogenesis, wound healing, and development in which precise control of proteinase activity is important. The human plasma proteinase inhibitor alpha(2)-macroglobulin (alpha(2)M) regulates cellular growth by binding and modulating the activity of many cytokines and growth factors. These studies investigate the ability of native and activated alpha(2)M (alpha(2)M*) to bind to members of the FGF family. Both alpha(2)M and alpha(2)M* bind specifically and saturably to FGF-1, -2, -4, and -6, although the binding to alpha(2)M* is of significantly higher affinity. Neither alpha(2)M nor alpha(2)M* bind to FGF-5, -7, -9, or -10. FGF-2 was chosen for more extensive study in view of its important role in angiogenesis. It was demonstrated that FGF-2 binds to the previously identified TGF-beta binding site. The alpha(2)M* inhibits FGF-2-dependent fetal bovine heart endothelial cell proliferation in a dose-dependent manner. Unexpectedly, alpha(2)M* does not affect FGF-2-induced vascular tubule formation on Matrigel basement membrane matrix or collagen gels. Further studies demonstrate that FGF-2 partitions between fluid-phase alpha(2)M* and solid-phase Matrigel or collagen. These studies suggest that the ability of alpha(2)M* to modulate the activity of FGF-2 is dependent on an interplay with extracellular matrix components. (Blood. 2001;97:3450-3457)

Immunocytochemical analysis of cholinergic amacrine cells in the tiger salamander retina

Cholinergic amacrine cells in the tiger salamander retina were observed for the first time by using antibodies against choline acetyltransferase (ChAT). ChAT-immunoreactive cells were present in the inner nuclear layer (INL) and in the ganglion cell layer (GCL), and the somas of the former population (average diameter = 15.13 microm) were slightly smaller than those of the latter population (average diameter = 16.42 microm). The processes of these cells form two distinct narrow bands in the inner plexiform layer (IPL), one located near 0.2 inner plexiform units (IU) and the other near 0.65-0.7 IU. Soma size, cell density and spatial distribution of ChAT-positive cells were quantitatively analyzed. Our results suggest that cholinergic amacrine cells in the salamander retina are very similar to their counter parts in other species, and they can be used as a model system for studying cholinergic functions in the visual system.

Apoptotic cell death of cultured salamander photoreceptors induced by cccp: CsA-insensitive mitochondrial permeability transition

Photoreceptor degeneration is mediated by apoptosis in several animal models, although the underlying mechanisms are yet to be elucidated. We present here an apoptotic model based on a primary cell culture of tiger salamander photoreceptors, in which treatment with carbonyl cyanide m-chlorophenylhydrazone (cccp), a protonophore, induced apoptosis. Cells exposed to cccp showed condensed nuclei and displayed positive TdT-dUTP terminal nick-end labeling (TUNEL). In addition, 10–100 microM cccp rapidly induced a reduction of Delta psi(m) and &gt; or = 30 microM cccp induced a significant leakage of calcein from mitochondria to cytosol and nucleus, indicating a change in mitochondrial inner membrane permeability. Cyclosporin A (CsA), a transition pore blocker, did not prevent the cccp-induced MPT or the cccp-evoked apoptotic cell death, suggesting that cccp-induced apoptotic process was mediated by a CsA-insensitive pathway. This cell model provides an in vitro tool for studying mechanisms of photoreceptor apoptosis in isolated photoreceptors and may provide clues to the etiology of retinal degeneration.