92 research outputs found

    Bat species diversity trend along an elevation gradient: A study in Crocker Range Park, Sabah, Borneo

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    Bats (Order: Chiroptera) is a recognised group of bioindicators due to their sensitivity towards alterations in their immediate surroundings. With the threats of climate change becoming more severe on a daily basis, it is reasonable to collect data on how bat diversity is influenced by elevation. This will be useful to predict and monitor possible upslope shifting of bat species due to increase in surrounding temperature or anthropogenic pressure. Hence, this study aims to uncover the bat diversity trend at different elevations in Crocker Range Park (CRP), Sabah, Malaysia. Bat trappings were conducted in four substations within this park, covering an elevation spectrum from 450 to 1900 m a.s.l. The overall sampling managed to capture 133 individuals of bats, predominantly Pteropodidae, with the addition of two new species locality records for CRP, Murina peninsularis and Hypsugo vondermanni. Simple linear regression analyses revealed that both bat diversity and richness have an inverse linear relationship with elevation. Likewise, the Pearson’s correlation value, associating bat diversity with elevation, also shows that they have a negative relationship at r = -0.852. Heterogeneity of habitats explain this trend, as in the lower counterpart of CRP, lowland forests, which are richer in fruit and insect resources persist. Besides, lower land forests have better niche assortment, due to the distinctive layers stratification, allowing bats utilising different guilds to thrive in the same vegetation profile. This study further emphasises the role of CRP to protect most of the bat species found in Borneo, as well as serving as the baseline data for the future studies that look into the impact of temperature increment towards the upslope shifting of the bat population in CRP

    Development of a Humanized Antibody with High Therapeutic Potential against Dengue Virus Type 2

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    Dengue virus (DENV) infection remains a serious health threat despite the availability of supportive care in modern medicine. Monoclonal antibodies (mAbs) of DENV would be powerful research tools for antiviral development, diagnosis and pathological investigations. Here we described generation and characterization of seventeen mAbs with high reactivity for E protein of DENV. Four of these mAbs showed high neutralizing activity against DENV-2 infection in mice. The monoclonal antibody mAb DB32-6 showed the strongest neutralizing activity against diverse DENV-2 and protected DENV-2-infected mice against mortality in therapeutic models. We identified neutralizing epitopes of DENV located at residues K310 and E311 of viral envelope protein domain III (E-DIII) through the combination of biological and molecular strategies. Comparing the strong neutralizing activity of mAbs targeting A-strand with mAbs targeting lateral ridge, we found that epitopes located in A-strand induced stronger neutralizing activity than those located on the lateral ridge. DB32-6 humanized version was successfully developed. Humanized DB32-6 variant retained neutralizing activity and prevented DENV infection. Understanding the epitope-based antibody-mediated neutralization is crucial to controlling dengue infection. Additionally, this study also introduces a novel humanized mAb as a candidate for therapy of dengue patients

    HURP Expression-Assisted Risk Scores Identify Prognosis Distinguishable Subgroups in Early Stage Liver Cancer

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    Hepatoma up-regulated protein (HURP) is a component of the chromatin-dependent pathway for spindle assembly. We examined the prognostic predictive value of HURP in human hepatocellular carcinoma (HCC).HURP expression was evaluated by immunocytochemistry of fine needle aspirated hepatoma cells in 97 HCC patients with Barcelona Clinic Liver Cancer (BCLC) stage A. Subsequently, these patients underwent partial hepatectomy (nβ€Š=β€Š18) or radiofrequency ablation (nβ€Š=β€Š79) and were followed for 2 to 35 months. The clinicopathological parameters were submitted for survival analysis.HURP expression in aspirated HCC cells was detected in 19.6% patients. Kaplan-Meier survival analysis showed that positive HURP expression (Pβ€Š=β€Š0.023), cytological grading β‰₯3 (Pβ€Š=β€Š0.008), AFP β‰₯35 ng/mL (Pβ€Š=β€Š0.039), bilirubin β‰₯1.3 mg/dL (Pβ€Š=β€Š0.010), AST β‰₯50 U/L (Pβ€Š=β€Š0.003) and ALT β‰₯35 U/L (Pβ€Š=β€Š0.005) were all associated with a shorter disease-free survival. A stepwise multivariate Cox proportional hazard model revealed that positive HURP expression (HR, 2.334; 95% CI, 1.165-4.679, Pβ€Š=β€Š0.017), AST β‰₯50 U/L (HR, 3.697; 95% CI, 1.868-7.319, p<0.001), cytological grade β‰₯3 (HR, 4.249; 95% CI, 2.061-8.759, P<0.001) and tumor number >1 (HR, 2.633; 95% CI, 1.212-5.722, Pβ€Š=β€Š0.014) were independent predictors for disease-free survival. By combining the 4 independent predictors, patients with different risk scores (RS) showed distinguishable disease-free survival (RS≀1 vs. RSβ€Š=β€Š2, Pβ€Š=β€Š0.001; RSβ€Š=β€Š2 vs. RSβ€Š=β€Š3, P<0.001). In contrast, the patients cannot be separated into prognosis distinguishable subgroups by using AJCC/UICC TNM staging system.HCC patients with BCLC stage A can be separated into three prognosis-distinguishable groups by use of a risk score that is based upon HURP expression in aspirated HCC cells, ALT, cytological grade and tumor number

    Analysis of Epitopes on Dengue Virus Envelope Protein Recognized by Monoclonal Antibodies and Polyclonal Human Sera by a High Throughput Assay

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    Dengue virus is the leading cause of arboviral diseases worldwide. The envelope protein is the major target of neutralizing antibodies and vaccine development. While previous studies have reported several epitopes on envelope protein, the possibility of interdomain epitopes and the relationship of epitopes to neutralizing potency remain unexplored. We developed a high throughput dot blot assay by using 67 alanine mutants of surface-exposed envelope residues as a systematic approach to identify epitopes recognized by mouse monoclonal antibodies and polyclonal human sera. Our results suggested the presence of interdomain epitopes more frequent than previously appreciated. Compared with monoclonal antibodies generated by traditional protocol, the potent neutralizing monoclonal antibodies generated by a new protocol showed several unique features of their epitopes. Moreover, the predominant epitopes of antibodies against envelope protein in polyclonal sera can be identified by this assay. These findings have implications for future development of epitope-specific diagnostics and epitope-based dengue vaccine, and add to our understanding of humoral immune responses to dengue virus at the epitope level

    Phenomic analysis of chronic granulomatous disease reveals more severe integumentary infections in X-Linked compared with autosomal recessive chronic granulomatous disease

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    BACKGROUND : Chronic granulomatous disease (CGD) is an inborn error of immunity (IEI), characterised by recurrent bacterial and fungal infections. It is inherited either in an Xlinked (XL) or autosomal recessive (AR) mode. Phenome refers to the entire set of phenotypes expressed, and its study allows us to generate new knowledge of the disease. The objective of the study is to reveal the phenomic differences between XL and AR-CGD by using Human Phenotype Ontology (HPO) terms. METHODS : We collected data on 117 patients with genetically diagnosed CGD from Asia and Africa referred to the Asian Primary Immunodeficiency Network (APID network). Only 90 patients with sufficient clinical information were included for phenomic analysis. We used HPO terms to describe all phenotypes manifested in the patients. RESULTS : XL-CGD patients had a lower age of onset, referral, clinical diagnosis, and genetic diagnosis compared with AR-CGD patients. The integument and central nervous system were more frequently affected in XL-CGD patients. Regarding HPO terms, perianal abscess, cutaneous abscess, and elevated hepatic transaminase were correlated with XL-CGD. A higher percentage of XL-CGD patients presented with BCGitis/BCGosis as their first manifestation. Among our CGD patients, lung was the most frequently infected organ, with gastrointestinal system and skin ranking second and third, respectively. Aspergillus species, Mycobacterium bovis, and Mycobacteirum tuberculosis were the most frequent pathogens to be found. CONCLUSION : Phenomic analysis confirmed that XL-CGD patients have more recurrent and aggressive infections compared with AR-CGD patients. Various phenotypic differences listed out can be used as clinical handles to distinguish XL or AR-CGD based on clinical features.The Society for Relief of Disabled Children and Jeffrey Modell Foundation.https://www.frontiersin.org/journals/immunologydm2022Paediatrics and Child Healt
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