A human pluripotent stem cell-based model of SARS-CoV-2 infection reveals an ACE2-independent inflammatory activation of vascular endothelial cells through TLR4.

To date, the direct causative mechanism of SARS-CoV-2-induced endotheliitis remains unclear. Here, we report that human ECs barely express surface ACE2, and ECs express less intracellular ACE2 than non-ECs of the lungs. We ectopically expressed ACE2 in hESC-ECs to model SARS-CoV-2 infection. ACE2-deficient ECs are resistant to the infection but are more activated than ACE2-expressing ones. The virus directly induces endothelial activation by increasing monocyte adhesion, NO production, and enhanced phosphorylation of p38 mitogen-associated protein kinase (MAPK), NF-κB, and eNOS in ACE2-expressing and -deficient ECs. ACE2-deficient ECs respond to SARS-CoV-2 through TLR4 as treatment with its antagonist inhibits p38 MAPK/NF-κB/ interleukin-1ß (IL-1ß) activation after viral exposure. Genome-wide, single-cell RNA-seq analyses further confirm activation of the TLR4/MAPK14/RELA/IL-1ß axis in circulating ECs of mild and severe COVID-19 patients. Circulating ECs could serve as biomarkers for indicating patients with endotheliitis. Together, our findings support a direct role for SARS-CoV-2 in mediating endothelial inflammation in an ACE2-dependent or -independent manner.

High incidence of Plasmodium knowlesi malaria compared to other human malaria species in several hospitals in Malaysia.

Through the regional control programme, Malaysia has been successfully reducing the incidence of Plasmodium falciparum and Plasmodium vivax infections. However, the incidence of zoonotic malaria Plasmodium knowlesi infection is increasing and now has been the major cause of malaria in Malaysia especially Malaysian Borneo. The emergence of knowlesi infection has threatened the malaria elimination programme which the government aims to reduce the overall malaria infections by 2020. Unlike other benign human Plasmodium spp., P. knowlesi can cause fatal infections. The aim of this study was to determine the incidence and distribution of five human malaria parasites including P. knowlesi in Peninsular Malaysia and Malaysian Borneo. A total of 112 blood samples were collected from seven states and district hospitals in Peninsular Malaysia and Malaysian Borneo from year 2015 to 2016. The samples were examined by microscopy and further confirmed by nested PCR assay targeting 18S rRNA gene of Plasmodium spp. Following the nested PCR assays, a total of 54 (48.2%) samples were positive for P. knowlesi infections, 12 (10.7%) cases were positive for P. vivax infections, followed by 7 (6.3%) cases of P. falciparum and 4 (3.5%) cases of P. malariae. There were 3 cases (2.7%) of mixed infections (P. knowlesi/P. vivax). However, no cases were identified as P. ovale. A total of 32 (28.6%) cases were found as negative infections. LoopMediated Isothermal Amplification Assay (LAMP) was performed to confirm inconclusive results produced by microscopy and nested PCR. P. knowlesi showed the highest prevalence in Sarawak (n= 30), Sabah (n=13), Pulau Pinang (n=5) and Pahang (n=6). PCR and LAMP was not able to detect a large number of microscopy positive samples due to DNA degradation during storage and shipping. Among all the states involved in this study, the highest prevalence of P. knowlesi infection was found in Sabah and Sarawak.

Experimental Study on Plasmodium knowlesi Normocyte Binding Protein Xa Region II (PkNBPXaII) for Erythrocyte Binding.

Normocyte binding protein Xa (NBPXa) has been implied to play a significant role in parasite invasion of human erythrocytes. Previous phylogenetic studies have reported the existence of three types of NBPXa for Plasmodium knowlesi (PkNBPXa). PkNBPXa region II (PkNBPXaII) of type 1, type 2 and type 3 were expressed on mammalian cell surface and interacted with human and macaque (Macaca fascicularis) erythrocytes. The binding activities of PkNBPXaII towards human and macaque erythrocytes were evaluated using erythrocyte-binding assay (EBA). Three parameters were evaluated to achieve the optimal protein expression of PkNBPXaII and erythrocyte binding activity in EBA: types of mammalian cells, post transfection time and erythrocyte incubation time. COS-7, HEK-293, and CHO-K1 cells showed successful expression of PkNBPXaII, despite the protein expression is weak compared to the positive control. COS-7 was used in EBA. All three types of PkNBPXaII showed rosette formation with macaque erythrocytes but not with human erythrocytes. Future studies to enhance the PkNBPXaII expression on surface of mammalian cells is indeed needed in order to elucidate the specific role of PkNBPXaII in erythrocytes invasion.

Enteral myiasis causing acute dysentery: A case report.

Enteral myiasis or intestinal myiasis is acquired by ingesting food or water contaminated with dipteran fly eggs or larvae. Here, we describe a patient with intestinal myiasis presenting with acute dysentery caused by the larva of Hermetia illucens. The larva was identified morphologically, and its species confirmed through molecular analysis using polymerase chain reaction and sequencing based on mitochondrial cytochrome c oxidase subunit I gene (COI).

Enteral myiasis causing acute dysentery: A case report

@#Enteral myiasis or intestinal myiasis is acquired by ingesting food or water contaminated with dipteran fly eggs or larvae. Here, we describe a patient with intestinal myiasis presenting with acute dysentery caused by the larva of Hermetia illucens. The larva was identified morphologically, and its species confirmed through molecular analysis using polymerase chain reaction and sequencing based on mitochondrial cytochrome c oxidase subunit I gene (COI).

High incidence of Plasmodium knowlesi malaria compared to other human malaria species in several hospitals in Malaysia

@# Through the regional control programme, Malaysia has been successfully reducing the incidence of Plasmodium falciparum and Plasmodium vivax infections. However, the incidence of zoonotic malaria Plasmodium knowlesi infection is increasing and now has been the major cause of malaria in Malaysia especially Malaysian Borneo. The emergence of knowlesi infection has threatened the malaria elimination programme which the government aims to reduce the overall malaria infections by 2020. Unlike other benign human Plasmodium spp., P. knowlesi can cause fatal infections. The aim of this study was to determine the incidence and distribution of five human malaria parasites including P. knowlesi in Peninsular Malaysia and Malaysian Borneo. A total of 112 blood samples were collected from seven states and district hospitals in Peninsular Malaysia and Malaysian Borneo from year 2015 to 2016. The samples were examined by microscopy and further confirmed by nested PCR assay targeting 18S rRNA gene of Plasmodium spp. Following the nested PCR assays, a total of 54 (48.2%) samples were positive for P. knowlesi infections, 12 (10.7%) cases were positive for P. vivax infections, followed by 7 (6.3%) cases of P. falciparum and 4 (3.5%) cases of P. malariae. There were 3 cases (2.7%) of mixed infections (P. knowlesi/P. vivax). However, no cases were identified as P. ovale. A total of 32 (28.6%) cases were found as negative infections. LoopMediated Isothermal Amplification Assay (LAMP) was performed to confirm inconclusive results produced by microscopy and nested PCR. P. knowlesi showed the highest prevalence in Sarawak (n= 30), Sabah (n=13), Pulau Pinang (n=5) and Pahang (n=6). PCR and LAMP was not able to detect a large number of microscopy positive samples due to DNA degradation during storage and shipping. Among all the states involved in this study, the highest prevalence of P. knowlesi infection was found in Sabah and Sarawak.

Experimental Study on Plasmodium knowlesi Normocyte Binding Protein Xa Region II (PkNBPXaII) for Erythrocyte Binding

@# Normocyte binding protein Xa (NBPXa) has been implied to play a significant role in parasite invasion of human erythrocytes. Previous phylogenetic studies have reported the existence of three types of NBPXa for Plasmodium knowlesi (PkNBPXa). PkNBPXa region II (PkNBPXaII) of type 1, type 2 and type 3 were expressed on mammalian cell surface and interacted with human and macaque (Macaca fascicularis) erythrocytes. The binding activities of PkNBPXaII towards human and macaque erythrocytes were evaluated using erythrocyte-binding assay (EBA). Three parameters were evaluated to achieve the optimal protein expression of PkNBPXaII and erythrocyte binding activity in EBA: types of mammalian cells, post transfection time and erythrocyte incubation time. COS-7, HEK-293, and CHO-K1 cells showed successful expression of PkNBPXaII, despite the protein expression is weak compared to the positive control. COS-7 was used in EBA. All three types of PkNBPXaII showed rosette formation with macaque erythrocytes but not with human erythrocytes. Future studies to enhance the PkNBPXaII expression on surface of mammalian cells is indeed needed in order to elucidate the specific role of PkNBPXaII in erythrocytes invasion.

Elimination of contamination in loop-mediated isothermal amplification assay for detection of human malaria.

The LAMP assay, amplifies the target DNA rapidly, with 10-fold greater sensitivity than conventional PCR. The greater sensitivity also comes with greater risks of contamination. To overcome this issue, the current project includes either uracil DNA glycosylase (UDG) or a mineral oil overlay in the LAMP assay. Our results indicated that UDG or a mineral oil overlay can effectively prevent carryover contamination in the LAMP assay for the detection of human malaria. By incorporating these preventative methods, contamination can be eliminated and LAMP can potentially be used in the field; and point of care diagnosis for human malaria.

Elimination of contamination in loop-mediated isothermal amplification assay for detection of human malaria

@# The LAMP assay, amplifies the target DNA rapidly, with 10-fold greater sensitivity than conventional PCR. The greater sensitivity also comes with greater risks of contamination. To overcome this issue, the current project includes either uracil DNA glycosylase (UDG) or a mineral oil overlay in the LAMP assay. Our results indicated that UDG or a mineral oil overlay can effectively prevent carryover contamination in the LAMP assay for the detection of human malaria. By incorporating these preventative methods, contamination can be eliminated and LAMP can potentially be used in the field; and point of care diagnosis for human malaria.

Osmotic demyelination syndrome caused by normal saline correction in a patient admitted for gastric ulcer bleeding.

A 61-year-old male had osmotic demyelination syndrome caused by rapid correction of gastric ulcer bleeding and vomiting related hyponatraemia with normal saline. It is rare to see severe hyponatraemia caused by gastric ulcer bleeding and vomiting. Hypokalaemia may be the determinant predisposing factor. There was no specific brain image finding until 17 days after the initial clinical presentation of this disease. Brain diffusion weighted MRI series did not help for the early diagnosis in this case. Outcome of this case may be more favourable if we corrected his hyponatraemia with half-saline or other hypotonic saline and close monitored serum sodium level, and relowered with dextrose water and desmopressin once we observed that the correction rate of hyponatraemia was beyond the recommended rate.

Stepwise self-assembly of C60 mediated by atomic scale moiré magnifiers.

Self-assembly of atoms or molecules on a crystal surface is considered one of the most promising methods to create molecular devices. Here we report a stepwise self-assembly of C60 molecules into islands with unusual shapes and preferred sizes on a gold-indium-covered Si(111) surface. Specifically, 19-mer islands prefer a non-compact boomerang shape, whereas hexagonal 37-mer islands exhibit extraordinarily enhanced stability and abundance. The stepwise self-assembly is mediated by the moiré interference between an island with its underlying lattice, which essentially maps out the adsorption-energy landscape of a C60 on different positions of the surface with a lateral magnification factor and dictates the probability for the subsequent attachment of C60 to an island's periphery. Our discovery suggests a new method for exploiting the moiré interference to dynamically assist the self-assembly of particles and provides an unexplored tactic of engineering atomic scale moiré magnifiers to facilitate the growth of monodispersed mesoscopic structures.

Simultaneous detection of methicillin-resistant Staphylococcus aureus, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa by multiplex PCR.

A PCR-based assay that can simultaneously detect and differentiate five different types of nosocomial bacterial pathogens was developed. Six pairs of selected primers targeting femA (132 bp) and mecA (310 bp) of methicillin-resistant Staphylococcus aureus, gltA (722 bp) of Acinetobacter baumannii, phoA (903 bp) of Escherichia coli, mdh (364 bp) of Klebsiella pneumoniae and oprL (504 bp) of Pseudomonas aeruginosa were used in this study. The conditions were optimized for the multiplex PCR to ensure specific amplification of the selected targets. Sensitivity and specificity tests were also carried out using a blind test approach on 50 bacterial cultures and resulted in 100% for both positive and negative predictive values.

Broken even-odd symmetry in self-selection of distances between nanoclusters due to the presence or absence of topological solitons.

Depositing particles randomly on a 1D lattice is expected to result in an equal number of particle pairs separated by even or odd lattice units. Unexpectedly, the even-odd symmetry is broken in the self-selection of distances between indium magic-number clusters on a Si(100)-2×1 reconstructed surface. Cluster pairs separated by even units are less abundant because they are linked by silicon atomic chains carrying topological solitons, which induce local strain and create localized electronic states with higher energy. Our findings reveal a unique particle-particle interaction mediated by the presence or absence of topological solitons on alternate lattices.

Vitamin D receptor gene polymorphisms and distinct clinical phenotypes of hepatitis B carriers in Taiwan.

Vitamin D exhibits immunomodulatory and antiproliferative effects through vitamin D receptor (VDR) in chronic infections and cancers. We genotyped the BsmI (rs1544410), ApaI (rs7975232) and TaqI (rs731236) polymorphisms of VDR gene in 250 Taiwanese chronic hepatitis B virus (HBV) carriers who were categorized into six phenotypes. After adjustment for age and sex, the frequencies of the VDR B/b, B/a, B/T, B/a/T in patients with hepatitis flare(s) were lower than those without (7 vs 20%, P=0.009; 1 vs 9%, P=0.004; 3 vs 10%, P=0.007; 1 vs 9%, P=0.005, respectively); in contrast, T/t, A/T, A/t, b/A/t were higher in flare(s) (8 vs 3%, P=0.003; 49 vs 34%, P=0.027; 2 vs 1%, P=0.004; 0.5 vs 0%, P=0.001, respectively). In addition, B/b, B/B, T/t, b/A, B/a, B/A, B/T, B/t, A/t, b/A/T, B/a/T, B/A/T, B/A/t, b/A/t were higher in patients positive for HBeAg. The distribution of VDR genotypes was comparable between patients with and without hepatocellular carcinoma (HCC). VDR gene polymorphisms are associated with distinct clinical phenotypes in Taiwanese HBV carriers but not with HCC development.

P38-associated pathway involvement in apoptosis induced by photodynamic therapy with Lonicera japonica in human lung squamous carcinoma CH27 cells.

Photodynamic therapy (PDT) is an effective therapy for local malignant tumors. Lonicera japonica was found to have the anti-tumor effect. The aim of this study is to explore the mechanisms of apoptosis induced by PDT in lung CH27 carcinoma cells with alcohol extract from Lonicera japonica as photosensitizer. Our study indicated that Lonicera japonica extracts exhibited significant photocytotoxicity in CH27 cells at a concentration range of 50-150 microg/ml, with 0.4-1.2J/cm2 light dose. PDT with Lonicera japonica extracts-induced cell death is a typical apoptosis that was accompanied by DNA condensation, externalization of phosphatidylserine and formation of apoptotic bodies. PDT with Lonicera japonica extracts was shown to be caspase-3-independent apoptosis via activation of AIF in this study. P38-associated pathway may be involved in apoptosis induced by PDT with Lonicera japonica extracts in CH27 cells. We also have demonstrated that PDT with Lonicera japonica extracts-induced CH27 cells apoptosis was probably related to its ability to change the protein expression and distribution of heat shock protein 27.

Pegylated interferon alpha-2a versus standard interferon alpha-2a for treatment-naive dialysis patients with chronic hepatitis C: a randomised study.

BACKGROUND: Chronic hepatitis C virus (HCV) infection is prevalent in dialysis patients, and standard interferon monotherapy is the current standard of care for such patients. AIM: To investigate whether pegylated interferon has a better therapeutic efficacy and safety profile than standard interferon in dialysis patients with chronic hepatitis C. METHODS: 50 such patients were randomly assigned to receive either pegylated interferon alpha-2a 135 microg subcutaneously once per week or standard interferon alpha-2a 3 million units subcutaneously thrice per week for 24 weeks. The primary efficacy and safety end points were sustained virological response (SVR) by intention-to-treat analysis and treatment-related withdrawal rate during the study. RESULTS: In univariate analysis, patients receiving pegylated interferon alpha-2a tended to have a higher sustained virological response (SVR) than those receiving standard interferon alpha-2a (48% vs 20%, p = 0.07). By using multivariate analysis, treatment with pegylated interferon alpha-2a (p = 0.02) and pretreatment HCV RNA level <800 000 IU/ml (p = 0.007) were independently predictive of an SVR. All patients failing to achieve a rapid virological response (RVR) could not achieve an SVR. In addition, patients receiving pegylated interferon alpha-2a had a significantly lower treatment-related withdrawal rate than those receiving standard interferon alpha-2a (0% vs 20%, p = 0.04). CONCLUSIONS: Pegylated interferon alpha-2a once weekly provides more effective and safer therapy than standard interferon alpha-2a thrice weekly for treatment-naive dialysis patients with chronic hepatitis C.