Increased expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in rat cardiac allografts

This study was designed to investigate the role of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) during chronic cardiac allograft rejection. Wistar rats were used as donors, and SD rats as recipients heterotopic cardiac transplants. Recipients pretreated with inoculation of donor splenocytes (SPC) followed by cyclophosphamide (CP) were divided into 4 groups: (A) untreated group (n = 18) without immunosuppression; (B) SPC plus CP-treated group (n = 18) that were euthanized at 15-120 days posttransplantation; (C) CsA-treated group (n = 18) euthanized at 2-3 months posttransplantation; and (D) tolerance group (n = 18) treated with SPC plus CP and monitored for at least 1 year posttransplantation. Cardiac allografts were harvested at various times for immunohistochemical studies performed to evaluate the expression of ICAM-1 and VCAM-1. Pretreatment of animals with SPC and CP induced long-term cardiac allograft survival. Immunohistochemical staining demonstrated a low level of ICAM-1 and VCAM-1 expression in cardiac allograft muscle and coronary arteries among Groups B and D. In contrast, the expressions of ICAM-1 and VCAM-1 in cardiac allografts of Groups A and C were significantly higher than those in Groups B and D. Our results suggested that the expression of ICAM-1 and VCAM-1 plays an important role during the development of chronic cardiac allograft rejection.

The experimental study of cardiac allograft vasculopathy and myocardial fibrosis in rats

We sought to analyze the development of myocardial fibrosis and cardiac allograft vasculopathy (CAV) as a theoretical basis for the prevention and treatment of rejection. Heterotopic cardiac transplantation was performed from Wistar rats to Sprague-Dawley rats. The recipients pretreated with donor splenocyte (SPC) infusion followed by cyclophosphamide (CP) were divided into 3 groups: Control animals without immunosuppression (Group 1; n = 10); Group 2, CsA treatment (n = 10) with euthanasia 2-3 months posttransplantation; and Group 3 (n = 20), CP plus SPC treatment with 10 recipients euthanized at 2 weeks posttransplantation and 10 animals monitored for at least 1 year posttransplantation. Histological studies were performed to evaluate myocardial fibrosis and CAV; 2-3 days after transplantation, there was abundant infiltration of collagenous fibers in the adventitia and intima of the coronary arteries in Group 1 allografts. Group 2 allografts demonstrated abundant infiltration of collagenous fibers in the adventitia and intima of arteries and arterioles resulting in significant luminal stenosis. In contrast, pretreatment of animals with SPC and CP induced long-term allograft survival; myocardial fibrosis and CAV were dramatically reduced in Group 3 compared with Groups 1 and 2. The infiltration of collagenous fibers in coronary arteries was one of the major causes of CAV. Preconditioning of recipients with SPC followed by CP not only induced immune tolerance but also alleviated myocardial fibrosis and CAV in allografts.

A novel c.545-546insG mutation in the loricrin gene correlates with a heterogeneous phenotype of loricrin keratoderma

BACKGROUND

Loricrin keratoderma (LK) is a group of congenital skin abnormalities characterized by the common features of honeycomb palmoplantar keratoderma and diffused ichthyosiform dermatosis. Earlier studies have shown that LK is associated with genetic defects of the loricrin gene.

OBJECTIVES

To determine the correlation between a loricrin mutation and a heterogeneous phenotype of loricrin keratoderma.

METHODS

We obtained DNA samples from a large family in which affected members showed more severe hyperkeratosis on the dorsal parts of their hands, mild palmoplantar keratoderma with no honeycomb-like manifestations and generalized ichthyosis. Screening of the loricrin gene was performed by direct sequencing of the entire coding region. Plasmids encoding the green fluorescent protein-tagged human loricrin were constructed and transferred to 293A cells for subcellular localization analyses.

RESULTS

Molecular analyses of the loricrin gene identified a novel insertion mutation c.545-546insG that resulted in a frameshift after codon 182. This mutation was predicted to produce a mutant protein with a frameshift of its C-terminal sequence of amino acids that embeds a newly generated nuclear localization signal (NLS), and to be 22 amino acids longer than the wild-type protein due to a delayed termination codon. The NLSs appear to result in an accumulation of mutant loricrin within nuclei.

CONCLUSIONS

Our results extend the repertoire of loricrin mutations underlying LK, provide further evidence that heterogeneous phenotypes of LK may be the result of genetic heterogeneity of loricrin mutations, and demonstrate that nuclear accumulation of mutant loricrin is due to the nuclear targeting sequences in the mutant C-terminus.

Surface coating of carbon nanofibers/nanotubes by electrodeposition for multifunctionalization

Carbon nanomaterials in the form of paper sheets have been used as platforms to achieve multifunctionality. Combined with electrochemical deposition, room temperature synthesis of magnetic Ni coatings on individual carbon nanofibers (CNF) and/or carbon nanotubes (CNT) has been realized through solution penetration and ion diffusion. In addition to significant electrical conductivity improvement, the magnetic responses of the Ni coated carbon nanopaper sheets can be tuned within large ranges in terms of saturation magnetic field, remnant magnetization and coercivity. After being re-suspended in liquids, the magnetized CNFs/CNTs can be aligned with small external magnetic fields.

Differential Expression of Cathepsins and Cystatin C in Ovine Uteroplacental Tissues

Cathepsins (CTSs) are peptidases that have biological roles in degrading extracellular matrix, catabolism of intracellular proteins, and processing of pro-hormones. Cystatin C (CST3) is a secreted inhibitor of lysosomal cysteine proteases cathepsin B (CTSB) and CTSL. Our working hypothesis is that cathepsins and cystatins play important roles in implantation and placentation in sheep. Expression of CTSB, CTSD, CTSH, CTSK, CTSL, CTSS, CTSZ, and CST3 mRNAs was detected in ovine uteroplacental tissues with distinct temporal and/or spatial expression patterns between Days 40 and 120 of pregnancy. Of particular note, CTSB, CTSD, and CTSZ mRNAs were predominantly detected in the chorion of the placenta and were more abundant in the placentomes than the intercaruncular endometria. CTSL and CST3 mRNAs were abundant in the endometrial epithelia and chorion, whereas CTSK, CTSS and CTSH mRNAs were most abundant in the stratum compactum stroma of the intercaruncular endometrium. Consistent with localisation of mRNAs, immunoreactive CTSL and CST3 proteins were mainly observed in the intercaruncular endometrial glands and intercotyledonary placenta during later pregnancy. These results support the working hypothesis that CTS and CST3 in uteroplacental tissues are involved in endometrial remodelling and placentation in sheep.

Seroprevalence of hepatitis C in intravenous opioid users presenting in the early phase of injecting drug use in Singapore

INTRODUCTION

All over the world, Hepatitis C virus (HCV) accounts for an estimated 130 million chronic infections. Injection drug use has become one of the most important risk factors for HCV, and within the injection drug user population, the prevalence of HCV antibody ranges from 70 to 95 percent depending on an individual's length of use and the prevalence of infection in the community. This study was undertaken to determine the prevalence of and the risk factors for Hepatitis C antibodies in injecting drug users presenting to the Community Addictions Management Programme (CAMP) in Singapore.

METHODS

Eligibility criteria for inclusion in this study were all intravenous buprenorphine users presenting to CAMP. 106 subjects, who consented to the study, completed an interviewer-administered questionnaire, and underwent a urine and blood analysis.

RESULTS

The prevalence rate for HCV was 42.5 percent among the subjects included in our study. The odds of seroprevalence in those sharing needles were 5.6 times that of those who were not, and the odds of seroprevalence among those using with others (peers or partners) were 6.3 times, as compared to among those who were individual users. Racial differences were also seen, but these could be accounted for by the sharing of needles.

CONCLUSION

This study provides important local data at the onset of an early buprenorphine-injecting epidemic in Singapore. This data is useful for disease prevention and healthcare planning.

Contaminants-induced oxidative damage on the carp Cyprinus carpio collected from the upper Yellow River, China

The Yellow River, the second largest river in China, is the most important resource of water supply in North China. In the last 40 years, even in the upper Yellow River, with the development of industry and agriculture, more and more contaminants have been discharged into this river and greatly polluted the water. Although a routine chemical component analysis has been performed, little is known about the real toxic effects of the polluted water on organisms at environmental level. To explore whether the pollutants induced oxidative stress and damage to aquatic organisms, malondialdehyde (MDA) level and activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST) in hepatopancreas, kidney and intestine of the field-collected carp Cyprinus carpio from a mixed polluted (Lanzhou Region, LZR) and a relatively unpolluted (Liujiaxia Region, LJXR) sites of the upper Yellow River were measured. The results showed that when the values of LZR compared with those of LJXR, SOD and GST activities increased and GPx activity decreased significantly in all the three organs (P < 0.05-0.01); CAT activity decreased but MDA level increased significantly (P < 0.05-0.01) only in kidney and intestine. In conclusion, the results of this study suggest that the pollutants can induce obvious oxidative damage in the carp, and the SOD, GST and GPx might be better indicators for the oxidative damage in aquatic organisms.

Activation of immune and inflammatory systems in chronic heart failure: novel therapeutic approaches

Despite extensive research and novel treatments, chronic heart failure (CHF) remains a cause of high morbidity and mortality. Mounting evidence suggested that immune activation and inflammation play critical roles in the pathogenesis of CHF. In this review, we examine the current evidence regarding this contemporary pathophysiological mechanism, and evaluate the effects of conventional and novel cardiovascular drugs, such as calcium sensitisers and statins, on the immune and inflammatory mediator's network. Although therapies, which specifically antagonise tumour necrosis factor-alpha have not demonstrated considerable benefit in patients with CHF, there is an increasing evidence to suggest greater value from non-specific anti-inflammatory approaches, including: pentoxifylline, intravenous immunoglobulin, immune modulation therapy, growth hormones, physical training and nutrition regulation. Several innovative therapeutic targets, such as peroxisome proliferator-activated receptor gamma activators, Rho-kinase, p38 mitogen-activated protein kinase, nuclear transcription factor NF-kappaB, recovering or augmenting parasympathetic tone, cardiac resynchronisation therapy, macrophage inhibitors and chemokine receptor antagonists, are briefly discussed in this review. While we have recently demonstrated the potential merits of combining low-dose methotrexate with conventional therapy, through extensively modulating the activated immune and inflammatory mediator's network, there is a need for further rigorous research of this complex network, especially involving current promising therapies which modulate this system. Such evidence has the potential to revolutionise changes for the management of this disorder. Based on the 'heterogeneity' of immune activation and inflammation among different CHF populations, an 'optimised combination treatment' may offer exciting benefits for individual therapy in the future.

Nonassociative learning in expiratory inhibition of inspiratory motor output: an experimental and modeling study

The present study is to characterize the habituation and re-sensitization in the inspiratory inhibition produced by the Bötzinger Complex (BOt.C) and the modulation effects of raphe pallidus (RP) and locus coeruleus (LC). Experiments were done on urethane anaesthetized, vagotomized, paralyzed and artificially ventilated rabbits. Electrical stimulation of the BOt.C (25 ..A, 80 Hz, 15 sec) caused inspiratory inhibition that became gradually adapted with the continuation of the stimulation. At the offset of this stimulation, the phrenic discharge showed temporary rebound increase in amplitude. The adaptation-rebound response pattern resembled a neural differentiator. Pre-stimulation of the RP or LC (50 ..A, 80 Hz, 10 sec) facilitated the adaptation of BOt.C's inspiratory inhibition and the post-stimulus rebound. The results indicate the existence of nonassociative learning (habituation and re-sensitization) in the inspiratory inhibition circuit and the modulation of this nonassociative learning by RP and LC.

Efficacy and efficiency of gastric electrical stimulation with short pulses in the treatment of vasopressin-induced emetic responses in dogs

The aim of this study was to determine the most effective and efficient anti-emetic parameters of short-pulse gastric electrical stimulation (GES) in dogs. Seven female beagle dogs implanted with four pairs of gastric electrodes were studied in eight randomized sessions (saline, vasopressin, and six GES sessions with different parameters). Each session consisted of four 20-min recordings of gastric slow waves and symptoms. In sessions 1 and 2, saline and vasopressin, respectively, were infused during the second 20-min period. The protocol of the other six sessions was the same as session 2 except that GES was continuously applied. It was found that: (1) vasopressin induced gastric dysrhythmia and emetic response (P < 0.01, anova); (2) short-pulse GES with a frequency of 14 or 40 Hz and pulse width of 0.1 or 0.3 ms, but not 0.6 ms was able to reduce symptoms induced by vasopressin; (3) short-pulse GES with a pulse width of 0.3 ms was the most effective in preventing vasopressin-induced symptoms; (4) none of the tested GES methods improved vasopressin-induced gastric dysrhythmia. We conclude that vasopressin induces gastric dysrhythmia and symptoms. Short-pulse GES with a pulse width of 0.3 ms and frequency of 14 Hz is most effective and efficient in preventing vasopressin-induced emetic responses in dogs.

Adrenoceptor blockade alters plasma gelatinase activity in patients with heart failure and MMP-9 promoter activity in a human cell line (ECV304)

This study assessed the effects of short-term adrenoceptor blockade on plasma matrix metalloproteinase (MMP) activity in patients with heart failure, and the ability of adrenoceptor stimulation to modulate matrix metalloproteinase-9 (MMP-9) promoter activity in vitro. Patients with heart failure received standard therapy or standard therapy plus carvedilol. Plasma MMP activity was determined by zymography and tissue inhibitor (TIMP-1) expression was measured by immunoblotting. MMP-9 promoter activity was assessed in transfected ECV304 cells following exposure to isoprenaline or phenylephrine in the absence or presence of either propranolol or prazosin. In patients with heart failure, carvedilol attenuated the increase in proMMP-9 activity observed at 4 and 12 weeks in non-beta-blocker-treated patients (44.0 +/- 4.9 AU versus 60.8 +/- 6.7 AU; P < 0.05). Although TIMP-1 expression was unaltered, the MMP-9:TIMP-1 ratio was lower in those receiving carvedilol at 4 and 12 weeks (0.54 +/- 0.07 versus 1.04 +/- 0.17; P < 0.05). Isoprenaline transiently increased MMP-9 promoter activity after 4 h exposure (80.6 +/- 14.8-fold; P < 0.001) before returning to baseline. The response to isoprenaline was prevented by propranolol (P < 0.01). Phenylephrine caused a biphasic increase in MMP-9 promoter activity, with the greatest increase occurring at 24 h (23 +/- 3.7-fold) compared to baseline. This response was unaffected by co-incubation with prazosin. In conclusion, treatment with a mixed alpha1/beta-adrenoceptor antagonist attenuates MMP activity and tips the degradative balance to a less degradative phenotype in heart failure patients. Furthermore, adrenoceptor stimulation increases MMP-9 promoter activity, which is inhibited by beta- but not alpha-adrenoceptor blockade. Therefore, mixed adrenoceptor blockade may reduce remodeling in heart failure as a direct consequence of a beta-adrenoceptor-mediated reduction in MMP-9 transcription.

Curcumin induces human HT-29 colon adenocarcinoma cell apoptosis by activating p53 and regulating apoptosis-related protein expression

Curcumin, a major yellow pigment and active component of turmeric, has multiple anti-cancer properties. However, its molecular targets and mechanisms of action on human colon adenocarcinoma cells are unknown. In the present study, we examined the effects of curcumin on the proliferation of human colon adenocarcinoma HT-29 cells by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide method and confirmed the curcumin-induced apoptosis by morphology and DNA ladder formation. At the same time, p53, phospho-p53 (Ser15), and other apoptosis-related proteins such as Bax, Bcl-2, Bcl-xL, pro-caspase-3, and pro-caspase-9 were determined by Western blot analysis. The colon adenocarcinoma cells were treated with curcumin (0-75 microM) for 0-24 h. We observed that p53 was highly expressed in HT-29 cells and curcumin could up-regulate the serine phosphorylation of p53 in a time- and concentration-dependent manner. An increase in expression of the pro-apoptotic factor Bax and a decrease in expression of the anti-apoptotic factor Bcl-2 were also observed in a time-dependent manner after exposure of 50 microM curcumin, while the expression of the anti-apoptotic factor Bcl-xL was unchanged. Curcumin could also down-regulate the expression of pro-caspase-3 and pro-caspase-9 in a time-dependent manner. These data suggest a possible underlying molecular mechanism whereby curcumin could induce the apoptosis signaling pathway in human HT-29 colon adenocarcinoma cells by p53 activation and by the regulation of apoptosis-related proteins. This property of curcumin suggests that it could have a possible therapeutic potential in colon adenocarcinoma patients.

Nonlinear dispersive three-dimensional finite-difference time-domain analysis for photonic-crystal lasers

The three-dimensional finite-difference time-domain method that can handle dispersive and dynamic nonlinear-gain media is proposed and realized. The effect of carrier diffusion is included through the laser rate equations. Through this three-dimensional nonlinear gain FDTD method, rich laser-dynamics behaviors, such as the lasing threshold, the relaxation oscillation, and the spatial hole burning, are directly observed from a hexapole mode.

Design of a high-Q channel add-drop multiplexer based on the two-dimensional photonic-crystal membrane structure

A significant improvement on the basic design of a channel add-drop multiplexer of the in-plane type, based on the two-dimensional photonic-crystal membrane structure of triangular-lattice holes, has been made to increase the channel-selectivity Q factor as high as 7300, which demonstrates the viability of the original basic design. The three-dimensional finite-difference time-domain simulation shows that theoretically it is possible to design a channel add-drop multiplexer with better than -0.7 dB of the forward-drop insertion loss, -29 dB of the pass-through cross-talk at the center frequency. A revised coupled-mode analysis with an augmented directional coupling gives a good agreement between its parametric analysis and the finite-difference time-domain analysis in regard to the detailed asymmetric forward-drop frequency response of the multiplexer.