Immunomodulatory proteins from hookworms reduce cardiac inflammation and modulate regulatory responses in a mouse model of chronic Trypanosoma cruzi infection

Introduction

Hookworms are parasitic helminths that secrete a variety of proteins that induce anti-inflammatory immune responses, stimulating increased CD4 + Foxp3+ regulatory T cells and IL-10 production. Hookworm-derived recombinant proteins AIP-1 and AIP-2 have been shown to reduce inflammation in mouse models of inflammatory bowel disease and inflammatory airway disease by inducing CD4+Foxp3+ cells and IL-10 production. In contrast, chronic infection with the protozoal parasite Trypanosoma cruzi, the causative agent of Chagas disease, leads to chronic inflammation in tissues. Persistence of the parasites in tissues drives chronic low-grade inflammation, with increased infiltration of inflammatory cells into the heart, accompanied by increased production of inflammatory cytokines. There are no current antiparasitic drugs that effectively reduce or prevent chronic myocarditis caused by the onset of Chagas disease, thus new therapies are urgently needed. Therefore, the impact of AIP-1 and AIP-2 on myocarditis was investigated in a mouse model of chronic T. cruzi infection.

Methods

Female BALB/c mice infected with bioluminescent T. cruzi H1 strain trypomastigotes for 70 days were treated once daily for 7 days with 1mg/kg AIP-1 or AIP-2 protein by intraperitoneal injection. Control mice were left untreated or treated once daily for 14 days with 25mg/kg aspirin in drinking water. At 84 days of infection, splenocytes, cardiac tissue and serum were collected for evaluation.

Results

Treatment with both AIP-1 and AIP-2 proteins significantly reduced cardiac cellular infiltration, and reduced cardiac levels of IFNγ, IL-6 and IL-2. AIP-2 treatment reduced cardiac expression of COX-2. Further, while incubation with AIP-1 and AIP-2 proteins did not induce a significant upregulation of an immunoregulatory phenotype in dendritic cells (DC), there was a modest upregulation of CD11c +CD11b+MHCII+SIRPα+ expression, suggesting a regulatory phenotype. Ex-vivo stimulation of splenocytes from the treatment groups with AIP-1 loaded DC induced reduced levels of cytotoxic and pro-inflammatory T cells, stimulation with AIP-2 loaded DC specifically induced enhanced levels of CD4+CD25+Foxp3+ regulatory T cells among treatment groups.

Discussion

All in vivo and in vitro results demonstrate that hookworm-derived AIP-1 and AIP-2 proteins reduce T. cruzi induced cardiac inflammation, possibly through multiple anti-inflammatory mechanisms.

Anesthesia in patients with Brugada syndrome: two case reports

BACKGROUND

Brugada syndrome is a rare disease. It causes sudden cardiac arrest, which is a serious life-threatening event. Sudden cardiac death mostly results from coronary artery disease. However, patients with Brugada syndrome show normal cardiac anatomy and no evidence of ischemia or electrolyte imbalance. Anesthesia in patients with Brugada syndrome is challenging due to its unpredictable nature, and is worth our attention.

CASE PRESENTATION

We report two cases of Brugada syndrome during anesthesia. In case one, a 31-year-old Filipino laborer was scheduled for laparoscopic appendectomy. The patient denied any preexisting cardiac disease. The preoperative vital signs were stable, with mild fever of 37.9 °C. The operation was smooth. During the emergence period, the patient suffered from sudden onset of ventricular tachycardia. After resuscitation, the cardiac rhythm returned to normal. Later, he was confirmed to have a genetic trait of Brugada syndrome. In case two, a young Taiwanese patient with pre-diagnosed Brugada syndrome underwent an operation. The perioperative precautions were taken to prevent the occurrence of ventricular arrhythmia. The surgery was uneventful.

CONCLUSIONS

Brugada syndrome, although rare, has the highest incidence in South East Asian healthy young males. It brings attention to possible fatal cardiac arrhythmia in this population. Careful preoperative evaluation and perioperative management can help reduce the harmful outcome of the disease and prevent any untoward events.

Chlamydia Infection Remodels Host Cell Mitochondria to Alter Energy Metabolism and Subvert Apoptosis

Chlamydia infection represents an important cause for concern for public health worldwide. Chlamydial infection of the genital tract in females is mostly asymptomatic at the early stage, often manifesting as mucopurulent cervicitis, urethritis, and salpingitis at the later stage; it has been associated with female infertility, spontaneous abortion, ectopic pregnancy, and cervical cancer. As an obligate intracellular bacterium, Chlamydia depends heavily on host cells for nutrient acquisition, energy production, and cell propagation. The current review discusses various strategies utilized by Chlamydia in manipulating the cell metabolism to benefit bacterial propagation and survival through close interaction with the host cell mitochondrial and apoptotic pathway molecules.

Chlamydia trachomatis plasmid-encoding Pgp3 protein induces secretion of distinct inflammatory signatures from HeLa cervical epithelial cells

BACKGROUND

Genital Chlamydia trachomatis infection is the most common bacterial sexual transmitted disease that causes severe complications including pelvic inflammatory disease, ectopic pregnancy, and infertility in females. The Pgp3 protein encoded by C. trachomatis plasmid has been speculated to be an important player in chlamydial pathogenesis. However, the precise function of this protein is unknown and thus remains to be thoroughly investigated.

METHODS

In this study, we synthesized Pgp3 protein for in vitro stimulation in the Hela cervical carcinoma cells.

RESULTS AND CONCLUSION

We showed that Pgp3 induced prominent expression of host inflammatory cytokine genes including interleukin-6 (IL-6), IL-8, tumor necrosis factor alpha-induced protein 3 (TNFAIP3), and chemokine C-X-C motif ligand 1 (CXCL1), implying a possible role of Pgp3 in modulating the inflammatory reaction in the host.

Experimental infection of tick cells with Nipah virus

Nipah virus (NiV), a highly pathogenic henipavirus of the family Paramyxoviridae, which causes fatal encephalitis in 40-70% of affected patients, was first reported in Malaysia over 20 years ago. Pteropid bats are the natural hosts of henipaviruses, and ticks have been proposed as a possible link between bats and mammalian hosts. To investigate this hypothesis, infection of the tick cell line IDE8 with NiV was examined. Presence of viral RNA and antigen in the NiV-infected tick cells was confirmed. Infectious virions were recovered from NiV-infected tick cells and ultrastructural features of NiV were observed by electron microscopy. These results suggest that ticks could support NiV infection, potentially playing a role in transmission.

[Correlation between fluid parameter and cardiovascular events in hemodialysis patients based on repeated body composition analyses]

Objective: To explore the correlation between fluid load index and cardiovascular events in hemodialysis patients based on repeated body composition analyses. Methods: A prospective cohort study was conducted to collect the clinical data of patients undergoing maintenance hemodialysis (MHD) in the Department of Nephrology, Hangzhou Hospital of Traditional Chinese Medicine from July to September 2020. The pre-dialysis fluid overload (FO) index-overhydration (OH) was measured by bioelectrical impedance method, and the follow-up monitoring was conducted every 6 months. According to the baseline OH value, patients were divided into non-FO group (OH≤2.5 L) and FO group (OH>2.5 L). Moreover, according to the repeated measurements, the patients were divided into continuous non-FO group, continuous FO group and intermittent FO group. All patients were followed up until October 1, 2022, and the outcomes were recorded. The end point of follow-up was cardiovascular events. The cumulative incidence of cardiovascular events was calculated by the Kaplan-Meier method, and the risk factors of cardiovascular events were analyzed by Cox proportional hazards regression model. Results: A total of 289 patients were included, including 88 patients (30.4%) with FO and 201 patients (69.6%) with non-FO. There were 168 males (58.1%) and 121 (41.9%) females, with an average age of (58±13) years and an average follow-up time of (22.0±6.5) months. Kaplan-Meier analysis showed that the incidence of cardiovascular events in the baseline FO group was higher than that in the non-FO group (log-rank χ²=14.44, P<0.001). The incidence of cardiovascular events in both the continuous FO group and the intermittent FO group was higher than that in the continuous non-FO group (log-rank χ²=41.47, P<0.001; log-rank χ²=18.36, P<0.001). After adjustment for gender, age, comorbidities, and biochemical indicators, the incidence of cardiovascular events in the baseline FO group was 1.850 times of the non-FO group (95%CI: 1.046-3.271, P=0.034). The incidence of cardiovascular events in the continuous FO group was 4.679 times of the continuous non-FO group (95%CI: 2.189-10.002, P<0.001). The incidence of cardiovascular events in the intermittent FO group was 3.410 times of the continuous non-FO group (95%CI: 1.696-6.857, P=0.001). Conclusions: OH value measured by bioelectrical impedance can be used as an important reference index for clinical monitoring of cardiovascular events in MHD patients. Continuous chronic and intermittent exposures to FO are risk factors for cardiovascular events in hemodialysis patients.

The Immunobiology of Nipah Virus

Nipah virus (NiV) is a highly lethal zoonotic paramyxovirus that emerged in Malaysia in 1998. It is a human pathogen capable of causing severe respiratory infection and encephalitis. The natural reservoir of NiV, Pteropus fruit bats, remains a continuous virus source for future outbreaks, although infection in the bats is largely asymptomatic. NiV provokes serious disease in various mammalian species. In the recent human NiV outbreaks in Bangladesh and India, both bats-to-human and human-to-human transmissions have been observed. NiV has been demonstrated to interfere with the innate immune response via interferon type I signaling, promoting viral dissemination and preventing antiviral response. Studies of humoral immunity in infected NiV patients and animal models have shown that NiV-specific antibodies were produced upon infection and were protective. Studies on cellular immunity response to NiV infection in human and animal models also found that the adaptive immune response, specifically CD4+ and CD8+ T cells, was stimulated upon NiV infection. The experimental vaccines and therapeutic strategies developed have provided insights into the immunological requirements for the development of successful medical countermeasures against NiV. This review summarizes the current understanding of NiV pathogenesis and innate and adaptive immune responses induced upon infection.

Comparative expression of pro-inflammatory and apoptotic biosignatures in chronic HBV-infected patients with and without liver cirrhosis

The interplay of immune mediators is paramount to optimal host anti-viral immune responses, especially against chronic hepatitis B virus (HBV) infection. Here, we investigated the dynamic changes in host immune responses in chronic HBV-infected individuals with and without liver cirrhosis by examining the signatures of apoptosis and plasma levels of pro-inflammatory cytokines, chemokines, and cytotoxic proteins. A total of 40 chronic HBV patients with and without liver cirrhosis were studied for plasma levels of immune mediators, and signatures of apoptosis in peripheral blood mononuclear cells (PBMCs). The intracellular concentrations of reactive oxygen species (ROS) in patients with chronic HBV with liver cirrhosis was relatively higher as compared to chronic HBV patients. The onset of apoptosis was sustained due to ongoing liver inflammation in concert with plasma TNF-α and IL-6 levels. Plasma VEGF was upregulated among chronic HBV patients with liver cirrhosis, whereas CCL2, CCL5 and granzyme B levels were down-regulated. High levels of ROS, IL-6 and TNF-α correlated with ongoing inflammation among chronic HBV patients with liver cirrhosis, which likely attributed to the expression of biosignatures of apoptosis and activation in immune cells.

Seroprevalence of Nipah Virus Infection in Peninsular Malaysia

Nipah virus (NiV) outbreak occurred in Malaysia in 1998. The natural host reservoir for NiV is Pteropus bats, which are commonly found throughout Malaysia. Humans become infected when NiV spills over from the reservoir species. In this study, NiV serosurveillance in Peninsular Malaysia, particularly among the indigenous population, was performed. The collected samples were tested for presence of NiV antibodies using a comparative indirect enzyme-linked immunosorbent assay based on the recombinant NiV nucleocapsid (rNiV-N) protein. We found that 10.73% of the participants recruited in this study had antibodies against rNiV-N, suggesting possible exposure to NiV.

Urbanization, Poverty and Child Health: Findings from Taiwan Birth Cohort

Background

We are living in an urban age. This study aims to examine whether living in big cities can be of help to reduce the health gap between the rich and poor children.

Methods

Data for the analysis came from the Taiwan Birth Cohort Study with a nationally representative sample of 18,814 children who completed the first (6-month) and eighth (12-year) waves of household interview survey. Poverty was defined as parental income below US$1,000 per month. Residence area was grouped into two groups: big city and non-big city; big city was defined as a national or provincial city. Children's health at age 12 was rated by mothers and divided into two groups: poor and non-poor. Multiple logistic regression was used to examine the joint effect of urbanization and poverty on children's health.

Results

We found that children who lived in poverty were more likely to have poor health than those who did not live in poverty (28.2% v 19.9%). When children were grouped according to the combination of residence at age of 6 months and 12 years old, we found that the prevalence of poor health at age 12 was the highest for poor children who lived continuously in big city (35.8%), followed by poor children who moved to big city (30.0%), poor children who lived continuously in non-big city (26.7%) and poor children who left big city (25.0%). Importantly, the prevalence of poor health for non-poor children was much lower and varied less across different residence groups, ranging from 19.7% to 21.4%. The interaction of poverty and urbanization on children's health was statistically significant (p &lt; 0.05) in multiple logistic regression analysis.

Conclusions

Our findings suggest that living in big cities be detriment to the health of children in poverty and widen the health gap between rich and poor children. Thus it is extremely important to shape urbanization for children, particularly for poor children.

Key messages

The poor children who live in big cities are more likely to have the worst health. We shall pay attention to the joint effect of urbanization and poverty on children’s health in order to reduce health inequalities.

Toxoplasma gondii infection among selected indigenous community in Sarawak, East Malaysia

Toxoplasma gondii is an obligate intracellular protozoan parasite that causes toxoplasmosis in humans. To date, little is known about T. gondii infection among the indigenous community, particularly in East Malaysia. This study was conducted to determine the status of T. gondii infection and to investigate associated risk factors among the indigenous community of Sarawak, East Malaysia. The sociodemographic data was obtained using a pretested questionnaire. A serological test was done to detect the presence of specific IgM and IgG antibodies against T. gondii in serum samples. A nested polymerase chain reaction (PCR) was used to determine acute infection among seropositive individuals. The overall seroprevalence of T. gondii infection was 50% (95% CI = 43.3 - 56.7). From this subset, 40.1%, 5.7%, and 4.2% were positive for anti-T. Gondii IgG antibodies, IgM, and both IgG and IgM, respectively. Four seropositive samples were amplified through PCR. None of the pregnant women tested positive for T. gondii infection based on the serological and PCR assays. A significant association was found between age, low monthly household income, unemployment, usage of untreated water and close contact with T. gondii seropositive cats. These results provide basic information on T. gondii infection and may be useful for policymakers to initiate prevention and control programs, especially amongst pregnant women and women of childbearing age in the indigenous community.

IncobotulinumtoxinA for the Treatment of Glabellar Frown Lines: A Prospective, Multicenter, Single-arm Study in Taiwan

Objective: We assessed clinical effectiveness, longevity of treatment effects, and patient satisfaction with incobotulinumtoxinA for glabellar frown lines (GFL) treatment in Asian patients. Design, Setting, and Participants: This was a prospective, multicenter, single-arm, open-label study at six sites in Taiwan. Patients aged 20 to 65 years with mild to very severe GFLs (Merz scale: 1-4 points) were eligible; 45 patients [including 23 BoNT/A-naïve and 22 previously-treated ("switch") patients were enrolled. Patients received intramuscular incobotulinumtoxinA injection at up to five injection points. Total doses ranged from 12 to 20U. Measurements: Investigators assessed improvements in dynamic GFLs at Days 14 and 120 using the validated five-point Merz scale (0=no lines; 4=very severe lines). Treatment satisfaction was self-reported by patients via questionnaire. Results: All patients showed excellent response to treatment in that Merz scores at Day 14 were 0 or 1 point(s). Both groups showed a mean improvement of 2.9 points; the response rate (1-point improvement or more from baseline) was 100 percent. GFL improvement was maintained over at least four months in both groups (mean improvements at Day 120: 1.5 points, naïve; 1.7 points, switch). Patient satisfaction ratings remained high (almost 100% in both groups) throughout the study. There were no statistically significant differences between groups regarding treatment satisfaction or GFL improvement (Merz score) at Days 14 and 120. No adverse events occurred. Conclusion: In Asian patients, incobotulinumtoxinA treatment for dynamic GFLs is effective and long lasting, with no expected differences between BoNT/A-naïve patients and those switching from other BoNT/As. IncobotulinumtoxinA yields consistent and natural-looking results for first and subsequent treatments.

Nipah Virus Infection of Immature Dendritic Cells Increases Its Transendothelial Migration Across Human Brain Microvascular Endothelial Cells

Nipah virus (NiV) can infect multiple organs in humans with the central nervous system (CNS) being the most severely affected. Currently, it is not fully understood how NiV spreads throughout the body. NiV has been shown to infect certain leukocyte populations and we hypothesized that these infected cells could cross the blood-brain barrier (BBB), facilitating NiV entry into the CNS. Here, three leukocyte types, primary immature dendritic cells (iDC), primary monocytes (pMO), and monocytic cell line (THP-1), were evaluated for permissiveness to NiV. We found only iDC and THP-1 were permissive to NiV. Transendothelial migration of mock-infected and NiV-infected leukocytes was then evaluated using an in vitro BBB model established with human brain microvascular endothelial cells (HBMEC). There was approximately a threefold increase in migration of NiV-infected iDC across endothelial monolayer when compared to mock-infected iDC. In contrast, migration rates for pMO and THP-1 did not change upon NiV infection. Across TNF-α-treated endothelial monolayer, there was significant increase of almost twofold in migration of NiV-infected iDC and THP-1 over mock-infected cells. Immunofluorescence analysis showed the migrated NiV-infected leukocytes retained their ability to infect other cells. This study demonstrates for the first time that active NiV infection of iDC and THP-1 increased their transendothelial migration activity across HBMEC and activation of HBMEC by TNF-α further promoted migration. The findings suggest that NiV infection of leukocytes to disseminate the virus via the “Trojan horse” mechanism is a viable route of entry into the CNS.

[Combined use of wide-detector and adaptive statistical iterative reconstruction-V technique in abdominal CT with low radiation dose]

Objective: To investigate the image quality and radiation dose with wide-detector(80 mm) and adaptive statistical iterative reconstruction-V (ASIR-V) technique at abdominal contrast enhanced CT scan. Methods: In the first phantom experiment part, the percentage of ASIR-V for half dose of combined wide detector with ASIR-V technique as compared with standard-detector (40 mm) technique was determined. The human experiment was performed based on the phantom study, 160 patients underwent contrast-enhanced abdominal CT scan were prospectively collected and divided into the control group (n=40) with image reconstruction using 40% ASIR (group A) and the study group (n=120) with random number table. According to pre-ASIR-V percentage, the study group was assigned into three groups[40 cases in each group, group B: 0 pre-ASIR-V scan with image reconstruction of 0-100% post-ASIR-V (interval 10%, subgroups B0-B10); group C: 20% pre-ASIR-V with 20%, 40% and 60% post-ASIR-V (subgroups C1-C3); group D: 40%pre-ASIR-V with 40% and 60% post-ASIR-V (subgroups D1-D2)]. Image noise, CT attenuation values and CNR of the liver, pancreas, aorta and portal vein were compared by using two sample t test and One-way ANOVA. Qualitative visual parameters (overall image quality as graded on a 5-point scale) was compared by Mann-Whitney U test and Kruskal-Wallis H test. Results: The phantom experiment showed that the percentage of pre-ASIR-V for half dose was 40%. With the 40% pre-ASIR-V, radiation dose in the study group was reduced by 35.5% as compared with the control group. Image noise in the subgroups of B2-B10, C2-C3 and D1-D2 were lower (t=-14.681--3.046, all P<0.05) while CNR in the subgroups of B4-B10, C2-3 and D1-D2 were higher(t=2.048-9.248, all P<0.05)than those in group A, except the CNR of liver in the arterial phase (AP) in C2, D1 and D2 and the CNR of pancreas in AP in D1 (t=0.574-1.327, all P>0.05). The subjective image quality scores increased gradually in the range of 0-60% post-ASIR-V and decreased with post-ASIR-V larger than 70%. The overall image quality of subgroup B3-B8, C2-C3 and D1-D2 were higher than that in group A (Z=-2.229--6.533, all P<0.05). Conclusion: Compared with stand-detector together with ASIR technique, wide-detector combined with 40% pre-ASIR-V technique with 60% post-ASIR-V image reconstruction can reduce radiation dose while maintain good overall image quality.

Oral immunization of a non-recombinant Lactococcus lactis surface displaying influenza hemagglutinin 1 (HA1) induces mucosal immunity in mice

Mucosal immunization of influenza vaccine is potentially an effective approach for the prevention and control of influenza. The objective of the present study was to evaluate the ability of oral immunization with a non-recombinant Lactococcus lactis displaying HA1/L/AcmA recombinant protein, LL-HA1/L/AcmA, to induce mucosal immune responses and to accord protection against influenza virus infection in mice. The LL-HA1/L/AcmA was orally administered into mice and the immune response was evaluated. Mice immunized with LL-HA1/L/AcmA developed detectable specific sIgA in faecal extract, small intestine wash, BAL fluid and nasal fluid. The results obtained demonstrated that oral immunization of mice with LL-HA1/L/AcmA elicited mucosal immunity in both the gastrointestinal tract and the respiratory tract. The protective efficacy of LL-HA1/L/AcmA in immunized mice against a lethal dose challenge with influenza virus was also assessed. Upon challenge, the non-immunized group of mice showed high susceptibility to influenza virus infection. In contrast, 7/8 of mice orally immunized with LL-HA1/L/AcmA survived. In conclusion, oral administration of LL-HA1/L/AcmA in mice induced mucosal immunity and most importantly, provided protection against lethal influenza virus challenge. These results highlight the potential application of L. lactis as a platform for delivery of influenza virus vaccine.

Eco-friendly luminescent solar concentrators with low reabsorption losses and resistance to concentration quenching based on aqueous-solution-processed thiolate-gold nanoclusters

Heavy-metal-containing quantum dots (QDs) with engineered electronic states have been served as luminophores in luminescent solar concentrators (LSCs) with impressive optical efficiency. Unfortunately, those QDs involve toxic elements and need to be synthesized in a hazardous solvent. Recently, biocompatible, eco-friendly gold nanoclusters (AuNCs), which can be directly synthesized in an aqueous solution, have gained much attention for promising applications in 'green photonics'. Here, we explored the solid-state photophysical properties of aqueous-solution-processed, glutathione-stabilized gold nanoclusters (GSH-AuNCs) with a ligand-to-metal charge-transfer (LMCT) state for developing 'green' LSCs. We found that such GSH-AuNCs exhibit a large Stokes shift with almost no spectral overlap between the optical absorption and PL emission due to the LMCT states, thus, suppressing reabsorption losses. Compared with GSH-AuNCs in solution, the photoluminescence quantum yields (PL-QYs) of the LSCs can be enhanced, accompanied with a lengthened PL lifetime owing to the suppression of non-radiative recombination rates. In addition, the LSCs do not suffer from severe concentration-induced PL quenching, which is a common weakness for conventional luminophores. As a result, a common trade-off between light-harvesting efficiency and solid-state PL-QYs can be bypassed due to nearly-zero spectral overlap integral between the optical absorption and PL emission. We expect that GSH-AuNCs hold great promise for serving as luminophores for 'green' LSCs by further enhancing solid-state PL-QYs.

Detection in Malaysia of a Borrelia sp. From Haemaphysalis hystricis (Ixodida: Ixodidae)

Spirochetes from the Borrelia genus are known to cause diseases in humans, namely Lyme disease and relapsing fever. These organisms are commonly transmitted to humans by arthropod vectors including ticks, mite, and lice. Here, we report the molecular detection of a Borrelia sp. from a Haemaphysalis hystricis Supino tick collected from wildlife in an Orang Asli settlement in Selangor, Malaysia. Phylogenetic analyses of partial 16s rRNA and flaB gene sequences revealed that the Borrelia sp. is closely related to the relapsing fever group borreliae, Borrelia lonestari, Borrelia miyamotoi, and Borrelia theileri, as well as a number of uncharacterized Borrelia sp. from ticks in Portugal and Japan. To our knowledge, this is the first report of a Borrelia sp. detected in H. hystricis, and in Malaysia. The zoonotic potential of this Borrelia sp. merits further investigation.

Geographical distribution of Brucella melitensis inferred from rpoB gene variation

INTRODUCTION

Currently available tests have limitations for the identification of Brucella species and strains, and their genetic lineage. The genome sequence of the rpoB gene encoding the β-subunit of DNA-dependent RNA polymerase was investigated for its use in genotyping Brucella melitensis.

METHODOLOGY

Complete rpoB gene sequences of globally distributed Brucella melitensis strains were analyzed. Single nucleotides polymorphisms (SNPs) of the rpoB gene sequences were identified and used to type Brucella melitensis strains.

RESULTS

Six DNA polymorphisms were identified, of which two (nucleotides 3201 and 558) were novel. Analysis of the geographical distribution of the strains revealed a spatial clustering pattern with rpoB type 1 representing European and American strains, rpoB type 2 representing European, African, and Asian strains, rpoB type 3 representing Mediterranean strains, and rpoB type 4 representing African (C3201T) and European (C3201T/T558A) strains.

CONCLUSIONS

We report the discovery of two novel SNPs of rpoB gene that can serve as useful markers for epidemiology and geographical tracking of B. melitensis.

Identification of the cell binding domain in Nipah virus G glycoprotein using a phage display system

Nipah virus (NiV) is a highly pathogenic zoonotic paramyxovirus with unusual broad host tropism and is designated as a Category C pathogen by the U.S. National Institute of Allergy and Infectious Diseases. NiV infection is initiated after binding of the viral G glycoprotein to the host cell receptor. The aim of this study was to map the NiV G glycoprotein cell binding domain using a phage display system. The NiV G extracellular domain was truncated and displayed as attachment proteins on M13 phage g3p minor coat protein. The binding efficiency of recombinant phages displaying different regions of NiV G to mammalian cells was evaluated. Results showed that regions of NiV G consisting of amino acids 396-602 (recombinant phage G4) and 498-602 (recombinant phage G5) demonstrated the highest binding to both Vero (5.5×10³ cfu/ml and 5.6×10³ cfu/ml) and THP-1 cells (3.5×10³ cfu/ml and 2.9×10³ cfu/ml). However, the binding of both of these recombinant phages to THP-1 cells was significantly lower than to Vero cells, and this could be due to the lack of primary host cell receptor expression on THP-1 cells. Furthermore, the binding between these two recombinant phages was competitive suggesting that there was a common host cell attachment site. This study employed an approach that is suitable for use in a biosafety level 2 containment laboratory without the need to use live virus to show that NiV G amino acids 498-602 play an important role for attachment to host cells.

[CT findings of inflammatory myofibroblastic tumor of different pathological types]

Objective: To explore the computed tomography(CT) features of inflammatory myofibroblastic tumor(IMT) in different pathological types, and improve the diagnostic level of this disease. Methods: The CT features of 29 cases pathologically confirmed IMTs were retrospectively reviewed along with a literature review to analyze the CT features and pathological correlations, and three kinds of pathological classification of IMT in patients with gender , shape, boundary and location were respectively analyzed by Chi-Square test. Results: The age ranges from 2 to 78 years.There were 7 cases of mucinous blood vessel type and 13 cases of spindle cell type and 9 cases of fiber type.Immunohistochemically, Vimentin (22/29) and SMA (28/29) were positive in all the cases, ALK (4/29) and CD-67(6/29) were partly positive expression, other markers such as S-100 were negative expression.The Chi-Square test showed that there were statistically differences in the gender of the patients. Conclusion: The CT and clinical features differ according to pathological types of IMT. Its final diagnosis still needs to be combined with pathology and immunohistochemistry result. In all, CT has a role in assessing the extension of IMT and especially about the relationship with adjacent organs which can effectively direct the establishment of clinical treating scheme.

Insertion of single-chain variable fragment (scFv) peptide linker improves surface display of influenza hemagglutinin (HA1) on non-recombinant Lactococcus lactis

Heterologous protein displayed on the surface of Lactococcus lactis using the binding domain of N-acetylmuramidase (AcmA) has a potential application in vaccine delivery. In this study, we developed a non-recombinant L. lactis surface displaying the influenza A (H1N1) 2009 hemagglutinin (HA1). Three recombinant proteins, HA1/L/AcmA, HA1/AcmA, and HA1 were overexpressed in Escherichia coli, and purified. In the binding study using flow cytometry, the HA1/L/AcmA, which contained the single-chain variable fragment (scFv) peptide linker showed significantly higher percentage of binding counts and mean fluorescence binding intensity (MFI) (51.7 ± 1.4% and 3,594.0 ± 675.9, respectively) in comparison to the HA1/AcmA without the scFv peptide linker (41.1 ± 1.5% and 1,652.0 ± 34.1, respectively). Higher amount of HA1/L/AcmA (∼2.9 × 10⁴ molecules per cell) was displayed on L. lactis when compared to HA1/AcmA (∼1.1 × 10⁴ molecules per cell) in the immunoblotting analysis. The HA1/L/AcmA completely agglutinated RBCs at comparable amount of protein to that of HA1/AcmA and HA1. Computational modeling of protein structures suggested that scFv peptide linker in HA1/L/AcmA kept the HA1 and the AcmA domain separated at a much longer distance in comparison to HA1/AcmA. These findings suggest that insertion of the scFv peptide linker between HA1 and AcmA improved binding of recombinant proteins to L. lactis. Hence, insertion of scFv peptide linker can be further investigated as a potential approach for improvement of heterologous proteins displayed on the surface of L. lactis using the AcmA binding domain. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:154-162, 2017.

Coxiella Detection in Ticks from Wildlife and Livestock in Malaysia

Recent studies have shown that ticks harbor Coxiella-like bacteria, which are potentially tick-specific endosymbionts. We recently described the detection of Coxiella-like bacteria and possibly Coxiella burnetii in ticks found from rural areas in Malaysia. In the present study, we collected ticks, including Haemaphysalis bispinosa, Haemaphysalis hystricis, Dermacentor compactus, Dermacentor steini, and Amblyomma sp. from wildlife and domesticated goats from four different locations in Malaysia. Coxiella 16s rRNA genomic sequences were detected by PCR in 89% of ticks tested. Similarity analysis and phylogenetic analyses of the 16s rRNA and rpoB partial sequences were performed for 10 representative samples selected based on the tick species, sex, and location. The findings here suggested the presence of C. burnetii in two samples, each from D. steini and H. hystricis. The sequences of both samples clustered with published C. burnetii sequences. The remaining eight tick samples were shown to harbor 16s rRNA sequences of Coxiella-like bacteria, which clustered phylogenetically according to the respective tick host species. The findings presented here added to the growing evidence of the association between Coxiella-like bacteria and ticks across species and geographical boundaries. The importance of C. burnetii found in ticks in Malaysia warrants further investigation.

Serum from Nipah Virus Patients Recognises Recombinant Viral Proteins Produced in Escherichia coli

The genes for Nipah virus (NiV) proteins were amplified from viral RNA, cloned into the plasmid pTriEx-3 Hygro, expressed, and purified using immobilized metal affinity chromatography. The recombinant N, F, and G NiV proteins (rNiV-N, rNiV-F, and rNiV-G), were successfully expressed in Escherichia coli and purified with a yield of 4, 16, and 4 mg/L, respectively. All 3 recombinant viral proteins reacted with all 19 samples of NiV-positive human sera. The rNiV-N and rNiV-G proteins were the most immunogenic. The recombinant viral proteins did not react with any of the 12 NiV-negative sera. However, serum from a patient with a late-onset relapsing NiV infection complication was found to be primarily reactive to rNiV-G only. Additionally, there is a distinctive variation in the profile of antigen-reactive bands between the sample from a case of relapsing NiV encephalitis and that of acute NiV infection. The overall findings of this study suggest that the recombinant viral proteins have the potential to be developed further for use in the detection of NiV infection, and continuous biosurveillance of NiV infection in resource-limited settings.

Bacterial community in Haemaphysalis ticks of domesticated animals from the Orang Asli communities in Malaysia

Ticks are vectors in the transmission of many important infectious diseases in human and animals. Ticks can be readily found in the semi-forested areas such as the settlements of the indigenous people in Malaysia, the Orang Asli. There is still minimal information available on the bacterial agents associated with ticks found in Malaysia. We performed a survey of the bacterial communities associated with ticks collected from domestic animals found in two Orang Asli villages in Malaysia. We collected 62 ticks, microscopically and molecularly identified as related to Haemaphysalis wellingtoni, Haemaphysalis hystricis and Haemaphysalis bispinosa. Bacterial 16s rRNA hypervariable region (V6) amplicon libraries prepared from the tick samples were sequenced on the Ion Torrent PGM platform. We detected a total of 392 possible bacterial genera after pooling and sequencing 20 samples, indicating a diverse bacterial community profile. Dominant taxa include the potential tick endosymbiont, Coxiella. Other dominant taxa include the tick-associated pathogen, Rickettsia, and environmental bacteria such as Bacillus, Mycobacterium, Sphingomonas and Pseudomonas. Other known tick-associated bacteria were also detected, including Anaplasma, Ehrlichia, Rickettsiella and Wolbachia, albeit at very low abundance. Specific PCR was performed on selected samples to identify Rickettsia and Coxiella. Sequence of Rickettsia felis, which causes spotted fever in human and cats, was identified in one sample. Coxiella endosymbionts were detected in three samples. This study provides the baseline knowledge of the microbiome of ticks in Malaysia, focusing on tick-associated bacteria affecting the Orang Asli communities. The role of the herein found Coxiella and Rickettsia in tick physiology or disease transmission merits further investigation.

Temporal proteomic profiling of Chlamydia trachomatis-infected HeLa-229 human cervical epithelial cells

Chlamydia trachomatis is the leading causative agent of bacterial sexually transmitted infections worldwide which can lead to female pelvic inflammatory disease and infertility. A greater understanding of host response during chlamydial infection is essential to design intervention technique to reduce the increasing incidence rate of genital chlamydial infection. In this study, we investigated proteome changes in epithelial cells during C. trachomatis infection by using an isobaric tags for relative and absolute quantitation (iTRAQ) labeling technique coupled with a liquid chromatography-tandem mass spectrometry (LC-MS(3) ) analysis. C. trachomatis (serovar D, MOI 1)-infected HeLa-229 human cervical carcinoma epithelial cells (at 2, 4 and 8 h) showed profound modifications of proteome profile which involved 606 host proteins. MGST1, SUGP2 and ATXN10 were among the top in the list of the differentially upregulated protein. Through pathway analysis, we suggested the involvement of eukaryotic initiation factor 2 (eIF2) and mammalian target of rapamycin (mTOR) in host cells upon C. trachomatis infection. Network analysis underscored the participation of DNA repair mechanism during C. trachomatis infection. In summary, intense modifications of proteome profile in C. trachomatis-infected HeLa-229 cells indicate complex host-pathogen interactions at early phase of chlamydial infection.

Independent Emergence of the Cosmopolitan Asian Chikungunya Virus, Philippines 2012

Outbreaks involving the Asian genotype Chikungunya virus (CHIKV) caused over one million infections in the Americas recently. The outbreak was preceded by a major nationwide outbreak in the Philippines. We examined the phylogenetic and phylogeographic relationships of representative CHIKV isolates obtained from the 2012 Philippines outbreak with other CHIKV isolates collected globally. Asian CHIKV isolated from the Philippines, China, Micronesia and Caribbean regions were found closely related, herein denoted as Cosmopolitan Asian CHIKV (CACV). Three adaptive amino acid substitutions in nsP3 (D483N), E1 (P397L) and E3 (Q19R) were identified among CACV. Acquisition of the nsP3-483N mutation in Compostela Valley followed by E1-397L/E3-19R in Laguna preceded the nationwide spread in the Philippines. The China isolates possessed two of the amino acid substitutions, nsP3-D483N and E1-P397L whereas the Micronesian and Caribbean CHIKV inherited all the three amino acid substitutions. The unique amino acid substitutions observed among the isolates suggest multiple independent virus dissemination events. The possible biological importance of the specific genetic signatures associated with the rapid global of the virus is not known and warrant future in-depth study and epidemiological follow-up. Molecular evidence, however, supports the Philippines outbreak as the possible origin of the CACV.

Full genome SNP-based phylogenetic analysis reveals the origin and global spread of Brucella melitensis

Background

Brucellosis is an important zoonotic disease that affects both humans and animals. We sequenced the full genome and characterised the genetic diversity of two Brucella melitensis isolates from Malaysia and the Philippines. In addition, we performed a comparative whole-genome single nucleotide polymorphism (SNP) analysis of B. melitensis strains collected from around the world, to investigate the potential origin and the history of the global spread of B. melitensis.

Results

Single sequencing runs of each genome resulted in draft genome sequences of MY1483/09 and Phil1136/12, which covered 99.85% and 99.92% of the complete genome sequences, respectively. The B. melitensis genome sequences, and two B. abortus strains used as the outgroup strains, yielded a total of 13,728 SNP sites. Phylogenetic analysis using whole-genome SNPs and geographical distribution of the isolates revealed spatial clustering of the B. melitensis isolates into five genotypes, I, II, III, IV and V. The Mediterranean strains, identified as genotype I, occupied the basal node of the phylogenetic tree, suggesting that B. melitensis may have originated from the Mediterranean regions. All of the Asian B. melitensis strains clustered into genotype II with the SEA strains, including the two isolates sequenced in this study, forming a distinct clade denoted here as genotype IId. Genotypes III, IV and V of B. melitensis demonstrated a restricted geographical distribution, with genotype III representing the African lineage, genotype IV representing the European lineage and genotype V representing the American lineage.

Conclusion

We showed that SNPs retrieved from the B. melitensis draft full genomes were sufficient to resolve the interspecies relationships between B. melitensis strains and to discriminate between the vaccine and endemic strains. Phylogeographic reconstruction of the history of B. melitensis global spread at a finer scale by using whole-genome SNP analyses supported the origin of all B. melitensis strains from the Mediterranean region. The possible global distribution of B. melitensis following the ancient trade routes was also consistent with whole-genome SNP phylogeny. The whole genome SNP phylogenetics analysis, hence is a powerful tool for intraspecies discrimination of closely related species.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1294-x) contains supplementary material, which is available to authorized users.

Outbreak of human infection with Sarcocystis nesbitti, Malaysia, 2012

An outbreak of fever associated with myalgia and myositis occurred in 2012 among 89 of 92 college students and teachers who visited Pangkor Island, Malaysia. The Sarcocystis nesbitti 18S rRNA gene and sarcocysts were obtained from muscle tissues of 2 students. Our findings indicate emergence of S. nesbitti infections in humans in Malaysia.

Tick-borne viruses: a review from the perspective of therapeutic approaches

Several important human diseases worldwide are caused by tick-borne viruses. These diseases have become important public health concerns in recent years. The tick-borne viruses that cause diseases in humans mainly belong to 3 families: Bunyaviridae, Flaviviridae, and Reoviridae. In this review, we focus on therapeutic approaches for several of the more important tick-borne viruses from these 3 families. These viruses are Crimean-Congo hemorrhagic fever virus (CCHF) and the newly discovered tick-borne phleboviruses, known as thrombocytopenia syndromevirus (SFTSV), Heartland virus and Bhanja virus from the family Bunyaviridae, tick-borne encephalitis virus (TBEV), Powassan virus (POWV), Louping-ill virus (LIV), Omsk hemorrhagic fever virus (OHFV), Kyasanur Forest disease virus (KFDV), and Alkhurma hemorrhagic fever virus (AHFV) from the Flaviviridae family. To date, there is no effective antiviral drug available against most of these tick-borne viruses. Although there is common usage of antiviral drugs such as ribavirin for CCHF treatment in some countries, there are concerns that ribavirin may not be as effective as once thought against CCHF. Herein, we discuss also the availability of vaccines for the control of these viral infections. The lack of treatment and prevention approaches for these viruses is highlighted, and we hope that this review may increase public health awareness with regard to the threat posed by this group of viruses.

Analysis of effects of manhole covers on motorcycle driver maneuvers: a nonparametric classification tree approach

OBJECTIVE

A manhole cover is a removable plate forming the lid over the opening of a manhole to allow traffic to pass over the manhole and to prevent people from falling in. Because most manhole covers are placed in roadway traffic lanes, if these manhole covers are not appropriately installed or maintained, they can represent unexpected hazards on the road, especially for motorcycle drivers. The objective of this study is to identify the effects of manhole cover characteristics as well as driver factors and traffic and roadway conditions on motorcycle driver maneuvers.

METHOD

A video camera was used to record motorcycle drivers' maneuvers when they encountered an inappropriately installed or maintained manhole cover. Information on 3059 drivers' maneuver decisions was recorded. Classification and regression tree (CART) models were applied to explore factors that can significantly affect motorcycle driver maneuvers when passing a manhole cover.

RESULTS

Nearly 50 percent of the motorcycle drivers decelerated or changed their driving path to reduce the effects of the manhole cover. The manhole cover characteristics including the level difference between manhole cover and pavement, the pavement condition over the manhole cover, and the size of the manhole cover can significantly affect motorcycle driver maneuvers. Other factors, including traffic conditions, lane width, motorcycle speed, and loading conditions, also have significant effects on motorcycle driver maneuvers.

CONCLUSIONS

To reduce the effects and potential risks from the manhole covers, highway authorities not only need to make sure that any newly installed manhole covers are as level as possible but also need to regularly maintain all the manhole covers to ensure that they are in good condition. In the long run, the size of manhole covers should be kept as small as possible so that the impact of manhole covers on motorcycle drivers can be effectively reduced. Supplemental materials are available for this article. Go to the publisher's online edition of Traffic Injury Prevention to view the supplemental file.

Modeling tenderness for genetic and quantitative trait loci analyses

Tenderness is the one of the most important attributes of beef with regards to the intent of consumers to repurchase. Beef tenderness is frequently measured objectively as Warner-Bratzler shear force. However, to better understand the genetics underlying tenderness, better descriptors were derived herein. Two traits, adjusted shear force and aging rate, were calculated to incorporate measures of Warner-Bratzler shear force repeated over aging time of 2 muscles, longissimus dorsi (LD) and semitendinosus (ST). Analysis of these traits indicated that the shear forces of the 2 muscles are lowly correlated and aging rate, as calculated, was not correlated with adjusted shear force. Breed, SNP, and QTL effects were analyzed for the 4 traits (2 traits × 2 muscles). For adjusted shear force, the QTL were located on cattle chromosomes BTA 5, 18, 25, and 29. With the exception of the QTL on BTA 5, the adjusted shear force QTL were observed for either the LD or the ST but not both muscles. The QTL for aging rate were located on BTA 1, 4, 7, 11, 13, 19, and 20.

A program to interest medical students in Changhua, Taiwan in the incorporation of visual arts in medicine

INTRODUCTION

Visual arts have been used to facilitate the teaching of the United States Accreditation Council for Graduate Medical Education (ACGME) competencies used in some countries. Some medical students may not appreciate the usefulness of incorporating arts in medical education. Therefore, arts programs that can interest medical students are necessary. We initiated and evaluated a visual arts program at the Changhua Christian Hospital in Changhua, Taiwan, with an aim to give the students a short review of visual arts and to interest them in the incorporation of arts in medicine.

METHODS

A total of 110 students in clerkship or internship participated in a visual arts program with emphasis on medicine-related visual arts. Content analysis of the data from the notes made by the instructor from direct observation of students; descriptions during discussions and the written feedback from students at the end of the program was used to evaluate the effect of the program. Anonymous questionnaires were also used for self-assessment of students.

RESULTS

Qualitative analysis of the data revealed that the course was interesting to students. Themes emerged including its helpfulness to students in interpreting paintings, enhanced empathy, increased cultural awareness, enhanced observational skills, better team work, listening and communication skills and reduced stress. Ratings on the questionnaire showed similar results. Moreover, students had an increase in their confidence and desire to interpret paintings.

CONCLUSION

The structured visual arts program, with emphasis on medicine-related visual arts and other humanities subjects, was able to attract the attention of medical students. It might be helpful to improve the required skills of ACGME competencies, but further studies are needed to support these conclusions.

Characterization of Nipah virus from naturally infected Pteropus vampyrus bats, Malaysia

We isolated and characterized Nipah virus (NiV) from Pteropus vampyrus bats, the putative reservoir for the 1998 outbreak in Malaysia, and provide evidence of viral recrudescence. This isolate is monophyletic with previous NiVs in combined analysis, and the nucleocapsid gene phylogeny species.

Association between coronary artery calcification using low-dose MDCT coronary angiography and bone mineral density in middle-aged men and women

Six hundred sixty-one participants who had at least one cardiac risk factor but were without known coronary heart disease underwent low-dose multidetector computed tomography coronary angiography (MDCT-CA) and dual-energy X-ray absorptiometry. The association between presence of subclinical coronary calcified plaque and low bone mineral density for the middle-aged individual was not significant after multivariate adjustment.

INTRODUCTION

Results of previous clinical studies assessing the relationship between osteoporosis and coronary calcification are inconsistent. This study aimed to evaluate the association between subclinical coronary calcification and osteoporosis in middle-aged men, premenopausal women, and postmenopausal women by using low-dose MDCT-CA and bone mineral density (BMD).

METHODS

This study enrolled 661 participants with at least one cardiac risk factor but without known coronary artery disease (CAD). All subjects underwent low-dose MDCT-CA and dual-energy X-ray absorptiometry on the same day.

RESULTS

The mean age was 52.2 years for men, 44.8 years for premenopausal women, and 59.1 years for postmenopausal women. The prevalence of calcified plaques between men with normal BMD and low BMD at lumbar spine were significantly different (P=0.042). The prevalence of mixed plaque and calcified plaque between pre- and postmenopausal women with normal BMD and low BMD at lumbar spine and femoral neck were not significantly different (P>0.05). Possible association between lumbar spine, femoral neck, and total proximal femur BMD and the presence of CAP was evaluated for men, premenopausal women, and postmenopausal women using multivariate logistic regression analysis: results were not significant (P>0.05).

CONCLUSION

Our study demonstrates that the association between the presence of subclinical coronary calcification and low BMD among middle-aged men and women was not significant after controlling for age and other risk factors for CAD and osteoporosis.

Synaptic plasticity after chemical deafening and electrical stimulation of the auditory nerve in cats

The effects of deafness on brain structure and function have been studied using animal models of congenital deafness that include surgical ablation of the organ of Corti, acoustic trauma, ototoxic drugs, and hereditary deafness. This report describes the morphologic plasticity of auditory nerve synapses in response to ototoxic deafening and chronic electrical stimulation of the auditory nerve. Normal kittens were deafened by neonatal administration of neomycin that eliminated auditory receptor cells. Some of these cats were raised deaf, whereas others were chronically implanted with cochlear electrodes at 2 months of age and electrically stimulated for up to 12 months. The large endings of the auditory nerve, endbulbs of Held, were studied because they hold a key position in the timing pathway for sound localization, are readily identifiable, and exhibit deafness-associated abnormalities. Compared with those of normal hearing cats, synapses of ototoxically deafened cats displayed expanded postsynaptic densities, a 35.4% decrease in synaptic vesicle (SV) density, and a reduction in the somatic size of spherical bushy cells (SBCs). In comparison with normal hearing cats, ototoxically deafened cats that received cochlear stimulation had endbulbs that expressed postsynaptic densities (PSDs) that were statistically identical in size, showed a 48.1% reduction in SV density, and whose target SBCs had a 25.5% reduction in soma area. These results demonstrate that electrical stimulation via a cochlear implant in chemically deafened cats preserves PSD size but not other aspects of synapse morphology. This determination further suggests that the effects of ototoxic deafness are not identical to those of hereditary deafness.

Human neuronal cell protein responses to Nipah virus infection

BACKGROUND

Nipah virus (NiV), a recently discovered zoonotic virus infects and replicates in several human cell types. Its replication in human neuronal cells, however, is less efficient in comparison to other fully susceptible cells. In the present study, the SK-N-MC human neuronal cell protein response to NiV infection is examined using proteomic approaches.

RESULTS

Method for separation of the NiV-infected human neuronal cell proteins using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) was established. At least 800 protein spots were resolved of which seven were unique, six were significantly up-regulated and eight were significantly down-regulated. Six of these altered proteins were identified using mass spectrometry (MS) and confirmed using MS/MS. The heterogenous nuclear ribonucleoprotein (hnRNP) F, guanine nucleotide binding protein (G protein), voltage-dependent anion channel 2 (VDAC2) and cytochrome bc1 were present in abundance in the NiV-infected SK-N-MC cells in contrast to hnRNPs H and H2 that were significantly down-regulated.

CONCLUSION

Several human neuronal cell proteins that are differentially expressed following NiV infection are identified. The proteins are associated with various cellular functions and their abundance reflects their significance in the cytopathologic responses to the infection and the regulation of NiV replication. The potential importance of the ratio of hnRNP F, and hnRNPs H and H2 in regulation of NiV replication, the association of the mitochondrial protein with the cytopathologic responses to the infection and induction of apoptosis are highlighted.

Detecting genetic predisposition for complicated clinical outcomes after burn injury

Sepsis, septic shock and organ failure are common among patients with moderate to severe burns. The inability of demographic and clinical factors to identify patients at high risk for such complications suggests that genetic variation may influence clinical outcome. Moreover, the genetic predisposition to death from infection has been estimated to be greater than for cardiovascular disease or cancer . While it is widely accepted that genetic factors influence many complex disease processes, controversy has emerged regarding the most appropriate methods for detection and even the validity of many published allelic associations . This article will review the few studies of genetic predisposition that have been conducted in the setting of burn injury, then discuss some of the obstacles and potential approaches for the discovery of additional allelic associations.

Analysis of traffic injury severity: an application of non-parametric classification tree techniques

Statistical regression models, such as logit or ordered probit/logit models, have been widely employed to analyze injury severity of traffic accidents. However, most regression models have their own model assumptions and pre-defined underlying relationships between dependent and independent variables. If these assumptions are violated, the model could lead to erroneous estimations of injury likelihood. The classification and regression tree (CART), one of the most widely applied data mining techniques, has been commonly employed in business administration, industry, and engineering. CART does not require any pre-defined underlying relationship between target (dependent) variable and predictors (independent variables) and has been shown to be a powerful tool, particularly for dealing with prediction and classification problems. This study uses the 2001 accident data for Taipei, Taiwan. A CART model was developed to establish the relationship between injury severity and driver/vehicle characteristics, highway/environmental variables and accident variables. The results indicate that the most important variable associated with crash severity is the vehicle type. Pedestrians, motorcycle and bicycle riders are identified to have higher risks of being injured than other types of vehicle drivers in traffic accidents.

HREM of the {111} surfaces of iron oxide nanoparticles

Mixed phase Fe3O4-gamma-Fe2O3 (magnetite-maghemite) iron oxide nanoparticles have been fabricated by colloidal routes. HRTEM/HRSTEM images of the nanoparticles show the presence of [111] facets that terminate with enhanced contrast, which is shown to be caused by the presence of additional cations at the edges of the nanoparticles. HRTEM images were taken on a FEI CM200 FEGTEM, a JEOL 3100 with a LaB6 source, and a double aberration corrected JEOL-JEM 2200FS FEGTEM. The enhanced contrast effect was observed on the [111] surface atomic layers resolved using each machine. HRSTEM images, taken on an aberration corrected STEM, resolved enhanced contrast at specific surface sites. Exit wave reconstruction was also carried out on focal series taken on a double aberration corrected JEOL-JEM 2200FS and showed similar highly resolved enhanced contrast at specific surface cation sites. It is apparent that additional cations are occupying the [111] terminating layers of these nanoparticle surfaces. The use of different microscopes and techniques in this paper provides strong evidence that the enhanced contrast is a real effect and not an effect caused by microscope aberrations.

Quantitative estimation of Nipah virus replication kinetics in vitro

BACKGROUND

Nipah virus is a zoonotic virus isolated from an outbreak in Malaysia in 1998. The virus causes infections in humans, pigs, and several other domestic animals. It has also been isolated from fruit bats. The pathogenesis of Nipah virus infection is still not well described. In the present study, Nipah virus replication kinetics were estimated from infection of African green monkey kidney cells (Vero) using the one-step SYBR Green I-based quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) assay.

RESULTS

The qRT-PCR had a dynamic range of at least seven orders of magnitude and can detect Nipah virus from as low as one PFU/microL. Following initiation of infection, it was estimated that Nipah virus RNA doubles at every approximately 40 minutes and attained peak intracellular virus RNA level of approximately 8.4 log PFU/microL at about 32 hours post-infection (PI). Significant extracellular Nipah virus RNA release occurred only after 8 hours PI and the level peaked at approximately 7.9 log PFU/microL at 64 hours PI. The estimated rate of Nipah virus RNA released into the cell culture medium was approximately 0.07 log PFU/muL per hour and less than 10% of the released Nipah virus RNA was infectious.

CONCLUSION

The SYBR Green I-based qRT-PCR assay enabled quantitative assessment of Nipah virus RNA synthesis in Vero cells. A low rate of Nipah virus extracellular RNA release and low infectious virus yield together with extensive syncytial formation during the infection support a cell-to-cell spread mechanism for Nipah virus infection.

On the importance of fifth-order spherical aberration for a fully corrected electron microscope

Next generation aberration correctors will not only eliminate the third-order spherical aberration, but also improve the information limit by correction of chromatic aberration. As a result of these improvements, higher order aberrations, which have largely been neglected in image analysis, will become important. In this paper, we concern ourselves with situations where sub-A resolution can be achieved, and where the third-order spherical aberration is corrected and the fifth-order spherical aberration is measurable. We derive formulae to explore the maximum value of the fifth-order spherical aberration for directly interpretable imaging and discuss the optimum imaging conditions and their applicable range.

Expression of a thermostable xylanase gene from Bacillus coagulans ST-6 in Lactococcus lactis

AIMS

The aim of the study is to evaluate whether xylanase can be used as a potential reporter gene for cloning and expression studies in Lactococcus.

METHODS AND RESULTS

The 750 bp xylanase gene was amplified and subcloned into the unique NheI restriction enzyme site of pMG36e and subsequently transformed into competent Escherichia coli XLI-blue MRF cells and Lactococcus lactis cells. Bacterial culture containing pMG36e-Xy has an enzyme activity of 390 microg xylose ml(-1) culture 30 min(-1), respectively, when compared with 40 microg xylose ml(-1) culture 30 min(-1) for the negative control (plasmidless strain).

CONCLUSIONS

The thermostable xylanase gene was successfully expressed in both E. coli and L. lactis. The activity of xylanase can be easily detected by the formation of visible clearing zones around the transformed colonies on Remazol Brilliant Blue-Xylan (RBB-Xylan) agar media. However, there were some significant differences in the optimum growth temperature and plasmid stability in the new clones.

SIGNIFICANCE AND IMPACT OF THE STUDY

The constructed reporter vector has the potential to be used as a reporter system for Lactococcus as well as E. coli, and it is an addition to the pool of lactococcal vector systems.

Nipah virus RNA synthesis in cultured pig and human cells

Nipah virus infection of porcine stable kidney cells (PS), human neuronal cells (SK-N-MC), human lung fibroblasts cells (MRC-5), and human monocytes (THP-1) were examined. Rapid progression of cytopathic effects (CPE) and cell death were noted in PS cell cultures treated with Nipah virus, followed by MRC-5, SK-N-MC, and THP-1 cell cultures, in descending order of rapidity. Significant increase in the intracellular Nipah virus RNA occurred beginning at 24 hr PI in all the infected cells. Whereas, the extracellular release of Nipah virus RNA increased significantly beginning at 48 and 72 hr PI for the infected MRC-5 cells and PS cells, respectively. No significant release of extracellular Nipah virus RNA was detected from the Nipah virus-infected SK-N-MC and THP-1 cells. At its peak, approximately 6.6 log PFU/microl of extracellular Nipah virus RNA was released from the Nipah virus-infected PS cells, with at least a 100-fold less virus RNA was recorded in the Nipah virus-infected SK-N-MC and THP-1. Approximately 15.2% (+/-0.1%) of the released virus from the infected PS cell cultures was infectious in contrast to approximately 5.5% (+/-0.7%) from the infected SK-N-MC cells. The findings suggest that there are no differences in the capacity to support Nipah virus replication between pigs and humans in fully susceptible PS and MRC-5 cells. However, there are differences between these cells and human neuronal cells and monocytes in the ability to support Nipah virus replication and virus release.