Shaoyu Wang

Matrine displayed antiviral activity in porcine alveolar macrophages co-infected by porcine reproductive and respiratory syndrome virus and porcine circovirus type 2

The co-infection of porcine reproductive respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) is quite common in clinical settings and no effective treatment to the co-infection is available. In this study, we established the porcine alveolar macrophages (PAM) cells model co-infected with PRRSV/PCV2 with modification in vitro, and investigated the antiviral activity of Matrine on this cell model and further evaluated the effect of Matrine on virus-induced TLR3,4/NF-κB/TNF-α pathway. The results demonstrated PAM cells inoculated with PRRSV followed by PCV2 2 h later enhanced PRRSV and PCV2 replications. Matrine treatment suppressed both PRRSV and PCV2 infection at 12 h post infection. Furthermore, PRRSV/PCV2 co- infection induced IκBα degradation and phosphorylation as well as the translocation of NF-κB from the cytoplasm to the nucleus indicating that PRRSV/PCV2 co-infection induced NF-κB activation. Matrine treatment significantly down-regulated the expression of TLR3, TLR4 and TNF-α although it, to some extent, suppressed p-IκBα expression, suggesting that TLR3,4/NF-κB/TNF-α pathway play an important role of Matrine in combating PRRSV/PCV2 co-infection. It is concluded that Matrine possesses activity against PRRSV/PCV2 co-infection in vitro and suppression of the TLR3,4/NF-κB/TNF-α pathway as an important underlying molecular mechanism. These findings warrant Matrine to be further explored for its antiviral activity in clinical settings.

Identification of the molecular mechanisms underlying the cytotoxic action of a potent platinum metallointercalator

Platinum-based DNA metallointercalators are structurally different from the covalent DNA binders such as cisplatin and its derivatives but have potent in vitro activity in cancer cell lines. However, limited understanding of their molecular mechanisms of cytotoxic action greatly hinders their further development as anticancer agents. In this study, a lead platinum-based metallointercalator, [(5,6-dimethyl-1,10-phenanthroline) (1S,2S-diaminocyclohexane)platinum(II)]2+ (56MESS) was found to be 163-fold more active than cisplatin in a cisplatin-resistant cancer cell line. By using transcriptomics in a eukaryotic model organism, yeast Saccharomyces cerevisiae, we identified 93 genes that changed their expressions significantly upon exposure of 56MESS in comparison to untreated controls (p ≤ 0.05). Bioinformatic analysis of these genes demonstrated that iron and copper metabolism, sulfur-containing amino acids and stress response were involved in the cytotoxicity of 56MESS. Follow-up experiments showed that the iron and copper concentrations were much lower in 56MESS-treated cells compared to controls as measured by inductively coupled plasma optical emission spectrometry. Deletion mutants of the key genes in the iron and copper metabolism pathway and glutathione synthesis were sensitive to 56MESS. Taken together, the study demonstrated that the cytotoxic action of 56MESS is mediated by its ability to disrupt iron and copper metabolism, suppress the biosynthesis of sulfur-containing amino acids and attenuate cellular defence capacity. As these mechanisms are in clear contrast to the DNA binding mechanism for cisplatin and its derivative, 56MESS may be able to overcome cisplatin-resistant cancers. These findings have provided basis to further develop the platinum-based metallointercalators as anticancer agents.

How do medical educators design a curriculum that facilitates student learning about professionalism

Objectives This study analyses the ways in which curriculum reform facilitated student learning about professionalism. Methods Design-based research provided the structure for an iterative approach to curriculum change which we undertook over a 3 year period. The learning environment of the Personal and Professional Development Theme (PPD) was analysed through the sociocultural lens of Activity Theory. Lave and Wenger’s and Mezirow’s learning theories informed curriculum reform to support student development of a patient-centred and critically reflective professional identity. The renewed pedagogical outcomes were aligned with curriculum content, learning and teaching processes and assessment, and intense staff education was undertaken. We analysed qualitative data from tutor interviews and free-response student surveys to evaluate the impact of curriculum reform. Results Students’ and tutors’ reflections on learning in PPD converged on two principle themes - ‘Developing a philosophy of medicine’ and ‘Becoming an ethical doctor’- which corresponded to the overarching PPD theme aims of communicative learning. Students and tutors emphasised the importance of the unique learning environment of PPD tutorials for nurturing personal development and the positive impact of the renewed assessment programme on learning. Conclusions A theory-led approach to curriculum reform resulted in student engagement in the PPD curriculum and facilitated a change in student perspective about the epistemological foundation of medicine.

Antiviral activity and underlying molecular mechanisms of Matrine against porcine reproductive and respiratory syndrome virus in vitro

Porcine reproductive and respiratory syndrome (PRRS), caused by porcine reproductive and respiratory syndrome virus (PRRSV), is an acute infectious disease. The prevalence of PRRS has made swine industry suffered huge financial losses. Matrine, a natural compound, has been demonstrated to possess anti-PRRSV activity in Marc-145 cells. However, the underlying molecular mechanisms were still unknown. The main objective of our study was to discuss the effect of Matrine on PRRSV N protein expression and PRRSV induced apoptosis. Indirect immunofluorescence assay (IFA) and Western blot were used to assess the effect of Matrine on N protein expression. Apoptosis was analyzed by fluorescence staining. In addition, the effect of Matrine on caspase-3 activation was investigated by Western blot. Indirect immunofluorescence assay and Western blot analysis demonstrated that Matrine could inhibit N protein expression in Marc-145 cells. And Matrine was found to be able to impair PRRSV-induced apoptosis by inhibiting caspase-3 activation.

Sodium tanshinone IIA sulfonate inhibits porcine reproductive and respiratory syndrome virus via suppressing N gene expression and blocking virus-induced apoptosis.

BACKGROUND Porcine reproductive and respiratory syndrome virus (PRRSV) causes significant economic loss in the swine industry. Currently, there is no effective way to prevent PRRSV infection. Sodium tanshinone IIA sulfonate (STS), a natural compound derived from Salvia miltiorrhiza, was shown to possess anti-PRRSV activity, but the underlying mechanisms remain unclear. The objective of this study was to investigate the effect of STS on PRRSV-induced cell apoptosis and PRRSV N protein expression pattern. METHODS Relative quantification real-time PCR was used to evaluate the inhibition of STS on N gene expression. Simultaneously indirect immunofluorescence assay (IFA) and western blot were used to assess the effect on N protein expression. Apoptosis was analysed using fluorescence microscope with an annexin V-EGFP kit. The effect of STS on caspase-3 cleaving was assessed by western blot. RESULTS Our results showed that STS could inhibit viral N gene expression at both the messenger RNA stage and at the protein level in PRRSV-infected cells in a dose-dependent manner. In addition, STS could also rescue PRRSV-induced apoptosis. CONCLUSIONS Our data suggest that STS may serve as a base compound for developing more effective drugs against PRRSV infection.

Maternal health care initiatives: Causes of morbidities and mortalities in two rural districts of Upper West Region, Ghana

Background Maternal and neonatal morbidities and mortalities have received much attention over the years in sub-Saharan Africa; yet addressing them remains a profound challenge, no more so than in the nation of Ghana. This study focuses on finding explanations to the conditions which lead to maternal and neonatal morbidities and mortalities in rural Ghana, particularly the Upper West Region. Method Mixed methods approach was adopted to investigate the medical and non-medical causes of maternal and neonatal morbidities and mortalities in two rural districts of the Upper West Region of Ghana. Survey questionnaires, in-depth interviews and focus group discussions were employed to collect data from: a) 80 expectant mothers (who were in their second and third trimesters, excluding those in their ninth month), b) 240 community residents and c) 13 healthcare providers (2 district directors of health services, 8 heads of health facilities and 3 nurses). Result Morbidity and mortality during pregnancy is attributed to direct causes such urinary tract infection (48%), hypertensive disorders (4%), mental health conditions (7%), nausea (4%) and indirect related sicknesses such as anaemia (11%), malaria, HIV/AIDS, oedema and hepatitis B (26%). Socioeconomic and cultural factors are identified as significant underlying causes of these complications and to morbidity and mortality during labour and the postnatal period. Birth asphyxia and traditional beliefs and practices were major causes of neonatal deaths. Conclusion These findings provide focused targets and open a window of opportunity for the community-based health services run by Ghana Health Service to intensify health education and promotion programmes directed at reducing risky economic activities and other cultural beliefs and practices affecting maternal and neonatal morbidity and mortality.

The use of antenatal care in two rural districts of Upper West Region, Ghana

Background Despite decades of implementation of maternity healthcare programmes, including a focus on increasing the use of antenatal care (ANC) and concomitant birth preparedness and complication readiness (BPCR), the uptake of ANC continues to be below expectations in many developing countries. This has attendant implications for maternal and infant morbidity and mortality rates. Known barriers to ANC use include cost, distance to health care services and forces of various socio-cultural beliefs and practices. As part of a larger study on BPCR in rural Ghana, this paper reflects on the use of ANC in the study areas from rights-based and maternal engagement theoretical perspectives, with a focus on the barriers to ANC use. Methods Mixed methods approach was adopted to collect data from 8 study communities from individual in-depth interviews with 80 expectant mothers and 13 health care professionals, and 24 focus groups comprising 240 community members. The qualitative data followed a thematic analytical method, while the quantitative data was analysed using descriptive statistics. Results The average number of ANC visits were 3.34±1.292, and the majority of expectant mothers (71.3%) enrolled for ANC at the 8th week or later, with the longest delay recorded at the 6th month of gestation. Traditional norms significantly influenced this delay. Likewise, overall use of ANC during pregnancy was shaped by cultural factors related to perceptions of pregnancy, gender-based roles and responsibilities and concerns that ANC would result in an overweighed baby and culturally inappropriate delivery at a health care facility. Conclusion Greater understanding of the sociocultural barriers to ANC is essential if proposed changes in community-specific health education programs are to facilitate early commencement and increased use of ANC.

Investigating the Biological Significance of Metallointercalators with cDNA Microarrays

The double helix coded sequence of nucleotide bases with its protective sugar phosphate backbone forms deoxyribonucleic acid (DNA) which is the genetic blueprint of all living things. All the information required for the development, operation and maintenance of cells is contained in a sequence of adenine (A), thymine (T), cytosine (C) and guanine (G) bases, where adenine is paired with thymine and cytosine is paired with guanine [1]. The DNA sequence is made usable by transcription of the nucleotide sequence into single stranded messenger RNA (mRNA).. This means that the four member nucleic acid base code sequence is converted into a 22 member amino acid code [2].