Immunoregulation effect by overexpression of heme oxygenase-1 on cardiac xenotransplantation

OBJECTIVE

This study was designed to investigate the effect of the overexpression of heme oxygenase-1 (HO-1) on the immunoregulation in the model of abdominal cardiac xenotransplantation from the guinea pig to the rat.

MATERIALS AND METHODS

To increase the expression of HO-1, both donors and recipients were injected with heme through the abdomen before the operation. The donors (guniea pigs) and the recipients (Sprague-Dawley [SD] rats) were divided randomly into three groups: group A, the heart from a guinea pig transplanted into the abdomen of an SD rat; group B, the recipients were injected with Chinese cobra venom factor (CVF) into the abdomen (40 μg/kg and 60 μg/kg 24 hours later) prior to transplantation; group C, CVF + HO-1 high-expression group: donors and recipients were abdominally injected with heme (75 μmol/kg for 2 days before transplantation). The mean survival time (MST), pathological changes, the positive area of HO-1 in the grafted hearts, as well as the expressions of C-C chemokine receptor 5 (CCR5), intercellular adhesion molecule-1 (ICAM-1), and natural killer (NK) cell activity in recipients.

RESULTS

1. The MST was longest in group C treated with heme. 2. The pathologic changes of hyperacute rejection were showed on the donor heart in group A, while delayed xenograft rejection changes took place on donor heart in other groups. 3. Compared with group B, The HO-1 positive area in the donor hearts of group C was significantly higher. (P < .05). 4. The lever of ICAM-1 and CCR5 in the peripheral blood of recipients (pg/mL) was attenuated in group C injected with heme. 5. Compared with group B, the activity of NK cell in the peripheral blood of recipients was much lower in group C (P < .05).

CONCLUSION

The MST was prolonged by increasing expressions of HO-1, but acute vascular rejection was not completely overcome. Activation of vascular endothelial cells could be decreased by strengthening the expression of HO-1. NK cell activity was weakened by reinforced expression of HO-1.

Microarray analysis of gene expression changes in the brains of NR2B-induced memory-enhanced mice

Glutamate N-methyl-D-aspartate (NMDA) receptors play a pivotal role in different forms of memory. The dysfunction of NMDA receptors contributes to the pathology of central nervous system (CNS) disorders. To further investigate the role of the NMDA receptors in brain processes, we analyzed and compared the gene expression profiles in the hippocampus of NR2B overexpression-induced memory-enhanced mice (Tg mice) with those of their wild-type littermates. Results reveal that 249 genes, which are mainly involved in neurotransmission, signal transduction, cytoskeletal structure, hormone activity, and transcription, were significantly affected in Tg mice. Interestingly, the intracellular calcium channel proteins ryanodine receptor (RyR) 1 and 3, as well as functionally related proteins such as the histidine-rich calcium-binding protein and triadin 2, were upregulated. The Homer-1c protein was also increased in Tg mice and formed a complex with the RyR protein in the mouse brain, suggesting that Homer-1c is an important modulator in both intracellular calcium signaling and overall neuronal signaling by simultaneously interacting with the NMDA receptors and RyR. Western blot and real-time PCR results show that the expression of phospho-CREB, c-fos, and the immediate-early genes Egr2 and Egr4 were also upregulated in Tg mice. The current study demonstrates that a chronic increase in the activation of NMDA receptors affected the expression of a large number of genes and may provide important clues for a better understanding of the molecular mechanism of NMDA receptor-modulated learning and memory, as well as of CNS disorders.

Taking into account latency, amplitude, and morphology: improved estimation of single-trial ERPs by wavelet filtering and multiple linear regression

Across-trial averaging is a widely used approach to enhance the signal-to-noise ratio (SNR) of event-related potentials (ERPs). However, across-trial variability of ERP latency and amplitude may contain physiologically relevant information that is lost by across-trial averaging. Hence, we aimed to develop a novel method that uses 1) wavelet filtering (WF) to enhance the SNR of ERPs and 2) a multiple linear regression with a dispersion term (MLR(d)) that takes into account shape distortions to estimate the single-trial latency and amplitude of ERP peaks. Using simulated ERP data sets containing different levels of noise, we provide evidence that, compared with other approaches, the proposed WF+MLR(d) method yields the most accurate estimate of single-trial ERP features. When applied to a real laser-evoked potential data set, the WF+MLR(d) approach provides reliable estimation of single-trial latency, amplitude, and morphology of ERPs and thereby allows performing meaningful correlations at single-trial level. We obtained three main findings. First, WF significantly enhances the SNR of single-trial ERPs. Second, MLR(d) effectively captures and measures the variability in the morphology of single-trial ERPs, thus providing an accurate and unbiased estimate of their peak latency and amplitude. Third, intensity of pain perception significantly correlates with the single-trial estimates of N2 and P2 amplitude. These results indicate that WF+MLR(d) can be used to explore the dynamics between different ERP features, behavioral variables, and other neuroimaging measures of brain activity, thus providing new insights into the functional significance of the different brain processes underlying the brain responses to sensory stimuli.

The primary somatosensory cortex largely contributes to the early part of the cortical response elicited by nociceptive stimuli

Research on the cortical sources of nociceptive laser-evoked brain potentials (LEPs) began almost two decades ago (Tarkka and Treede, 1993). Whereas there is a large consensus on the sources of the late part of the LEP waveform (N2 and P2 waves), the relative contribution of the primary somatosensory cortex (S1) to the early part of the LEP waveform (N1 wave) is still debated. To address this issue we recorded LEPs elicited by the stimulation of four limbs in a large population (n=35). Early LEP generators were estimated both at single-subject and group level, using three different approaches: distributed source analysis, dipolar source modeling, and probabilistic independent component analysis (ICA). We show that the scalp distribution of the earliest LEP response to hand stimulation was maximal over the central-parietal electrodes contralateral to the stimulated side, while that of the earliest LEP response to foot stimulation was maximal over the central-parietal midline electrodes. Crucially, all three approaches indicated hand and foot S1 areas as generators of the earliest LEP response. Altogether, these findings indicate that the earliest part of the scalp response elicited by a selective nociceptive stimulus is largely explained by activity in the contralateral S1, with negligible contribution from the secondary somatosensory cortex (S2).

Correlation between expression of cadherin and gap junctional communication in human lung carcinoma cells

The correlation between expression of ca(2+)-dependent cell adhesion molecule, cadherin, and gap junctional intercellular communication (GJIC) in human lung carcinoma PG cell line and connexin43 (Cx43) cDNA transfected PG cell clones was investigated. Results from immunoblotting and immunofluorescent staining revealed that cultured normal human lung cells (RF) expressed N-cadherin. However, the expression level of Kcadherin in PG cells was very low in comparison with normal RF cells. The Cx43 transfected PG clones exhibited comparable levels of Cx43 protein, but varied in the level of N-cadherin expression and in the function of GJIC as measured by scrape-loading and dye transfer (SLDT) method. Positive correlation between N-cadherin and GJIC was demonstrated. Thein vitro andin uivo, growth examination results suggest that N-cadherin mediated cell-cell adhesions and Cx43 functional expression, the GJIC, may work coordinately with each other in regulation of cell growth and differentiation. Deficiency in both GJIC and cell adhesion may be crucial for cell transformation.

Proteome analysis of wheat leaf under salt stress by two-dimensional difference gel electrophoresis (2D-DIGE)

Salt stress is a major abiotic stress that limits agricultural productivity in many regions of the world. To understand the molecular basis of the salt stress response in wheat (Triticum aestivum L.), a proteomic approach was used to identify the salt stress-responsive proteins in an elite Chinese wheat cultivar, Zhengmai 9023, which exhibits a high yield, superior gluten quality and better biotic resistance. Three-week-old seedlings were treated with NaCl of four different concentrations (1.0%, 1.5%, 2.0%, and 2.5%). The total proteins from the leaves of untreated and NaCl-treated plants were extracted and separated by two-dimensional difference gel electrophoresis (2D-DIGE). A total of 2358 protein spots were detected on the gels, among which 125 spots showed a significant change in protein abundance, and 83 differentially expressed spots were localised on preparative gels. Using Q-TOF mass spectrometry, 52 salt-responsive spots were identified, which were classified into six functional categories that included transport-associated proteins, detoxifying enzymes, ATP synthase, carbon metabolism, protein folding, and proteins with unknown biological functions. Of the 52 differentially expressed proteins, 26 were up-regulated, 21 were down-regulated, and five spots showed multi-expression patterns. In particular, some important proteins for salt tolerance were found to be up-regulated in Zhengmai 9023 under salt stress, such as H(+)-ATPases, glutathione S-transferase, ferritin and triosephosphate isomerase.

Patients' perception of health services for sexually transmitted infections in Singapore

INTRODUCTION

The Department of Sexually Transmitted Infections (STI) Control (DSC) Clinic is the only public STI clinic in Singapore. This study aimed to determine patients' perception of the clinic as well as the factors that may influence their choice of DSC Clinic over other medical facilities. The concerns of certain risk groups were also assessed.

METHODS

Self-administered anonymous questionnaires were offered to Singaporeans and Permanent Residents over 18 years of age who were seeking treatment at the DSC Clinic. 1,000 responses were collected over a period of four weeks in May 2009.

RESULTS

More than two-thirds of the patients had a positive experience at the DSC Clinic and would recommend the clinic to their family and friends. Positive attributes included competence of staff and the convenience of a one-stop treatment facility. The patients' visits to the DSC Clinic also prompted them to engage in safer sexual practices. Stigma was surprisingly not an issue among more than three-quarters of the patients. Confidentiality of medical records was a major concern, with more than half of the patients unwilling to share their records with other healthcare providers, employers or insurance companies. The majority of patients would like to see the provision of clinics catering to special groups such as young people, women as well as men-who-have-sex-with-men.

CONCLUSION

The majority of patients were satisfied with the health services provided at the DSC Clinic. Confidentiality in consultation was of prime importance to patients.

Identification of EGFR and KRAS mutations in Chinese patients with esophageal squamous cell carcinoma

The prognosis of esophageal squamous cell carcinoma (ESCC) is poor. It is urgent to improve this situation. Epidermal growth factor receptor (EGFR)-targeted therapy possesses a promising clinical efficacy. Mutations of EGFR and V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) have been identified in esophageal carcinoma, but corresponding Chinese data are limited. So we investigated the mutation status of EGFR and KRAS in Chinese patients with ESCC, and explored their correlations with clinicopathological features. Formalin-fixed paraffin-embedded surgically resected tumor samples were obtained from 50 randomly selected Chinese patients with ESCC. EGFR mutations in exons 18-21 were detected by Scorpions amplification refractory mutation system technology. KRAS mutations in codons 12, 13 were detected by direct sequencing of polymerase chain reaction products. The correlations between clinicopathological features and the mutation status of EGFR and KRAS were analyzed using the Statistical Package for the Social Sciences. In the present study, EGFR mutations were found in 7 (14%) out of 50 patients, including G719X missense mutation (n= 1), in-frame deletion (n= 2), and L858R missense mutation (n= 5). Six (12%) out of 50 patients had KRAS mutations in codon 12. Concurrent EGFR and KRAS mutations were detected in one sample. The presences of EGFR and KRAS mutations were not associated with gender, age, smoking history, cell differentiation, or cancer stage. In conclusion, the incidence of EGFR mutations in Chinese patients with ESCC was higher than that of previous reports, and the incidence of KRAS mutations was not low. EGFR and KRAS mutations were mainly located in exons 19 and 21 and codon 12, respectively. Unlike in NSCLC, concurrent EGFR and KRAS mutations existed.

High contrast 40Gbit/s optical modulation in silicon

Data interconnects are on the verge of a revolution. Electrical links are increasingly being pushed to their limits with the ever increasing demand for bandwidth. Data transmission in the optical domain is a leading candidate to satisfy this need. The optical modulator is key to most applications and increasing the data rate at which it operates is important for reducing power consumption, increasing channel bandwidth limitations and improving the efficiency of infrastructure usage. In this work silicon based devices of lengths 3.5mm and 1mm operating at 40Gbit/s are demonstrated with extinction ratios of up to 10dB and 3.5dB respectively. The efficiency and optical loss of the phase shifter is 2.7V.cm and 4dB/mm (or 4.5dB/mm including waveguide loss) respectively.