Lack of augmenting effect of interferon-γ on dengue virus multiplication in human peripheral blood monocytes

The effect of interferon—γ (IFN-γ) on dengue virus multiplication in human peripheral blood mono-cytes was investigated. Enriched monocytes were treated with IFN-γ and then infected with dengue virus type 2 either directly or in the presence of optimal infection-enhancing levels of antibodies. Pretreatment of monocytes from dengue-immune donors with 100 IU/ml of IFN-γ caused 12- to 97-fold and 13- to 137-fold reduction of virus yields at 24 hr after infection in the absence and presence of an anti-flavivirus monoclonal antibody, respectively. IFN-γ also diminished virus yields when infection of monocytes from a donor who lacked anti-dengue antibody was enhanced 40-fold. The percentage of infected monocytes in IFN-γ-pretreated cultures was similarly reduced. Dominance of the antiviral effect of IFN-γ in monocytes is in contrast to an augmenting effect previously observed in the promonocytic cell line U937. © 1995 Wiley-Liss, Inc.     

Young Men Who Have Sex with Men at High Risk for HIV,Bangkok MSM Cohort Study,Thailand 2006–2014

High HIV incidence has been reported in young men who have sex with men (YMSM) in North America and Western Europe, but there are limited data from Southeast Asia suggesting MSM may be the driver of the HIV epidemic in this region. We described HIV incidence and risk factors among 494 YMSM enrolled in a cohort study in Bangkok, Thailand. The HIV incidence was 7.4 per 100 person-years. In multivariable analysis, reporting use of an erectile dysfunction drug in combination with club drugs, having receptive or both insertive and receptive anal intercourse with men, having hepatitis A infection, having rectal Chlamydia trachomatis, having hepatitis B infection prior to HIV seroconversion, and reporting not always using condoms with male steady partners were significantly associated with HIV incidence in YMSM. Reduction in new HIV infections in YMSM are critical to reach targets set by Thailand and the region.     

Vascular leakage in severe dengue virus infections: a potential role for the nonstructural viral protein NS1 and complement

BACKGROUND: Vascular leakage and shock are the major causes of death in patients with dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Thirty years ago, complement activation was proposed to be a key underlying event, but the cause of complement activation has remained unknown. METHODS: The major nonstructural dengue virus (DV) protein NS1 was tested for its capacity to activate human complement in its membrane-associated and soluble forms. Plasma samples from 163 patients with DV infection and from 19 patients with other febrile illnesses were prospectively analyzed for viral load and for levels of NS1 and complement-activation products. Blood and pleural fluids from 9 patients with DSS were also analyzed. RESULTS: Soluble NS1 activated complement to completion, and activation was enhanced by polyclonal and monoclonal antibodies against NS1. Complement was also activated by cell-associated NS1 in the presence of specific antibodies. Plasma levels of NS1 and terminal SC5b-9 complexes correlated with disease severity. Large amounts of NS1, complement anaphylatoxin C5a, and the terminal complement complex SC5b-9 were present in pleural fluids from patients with DSS. CONCLUSIONS: Complement activation mediated by NS1 leads to local and systemic generation of anaphylatoxins and SC5b-9, which may contribute to the pathogenesis of the vascular leakage that occurs in patients with DHF/DSS.     

Preserving Brain Function in Aging: The Anti-glycative Potential of Berry Fruit

Advanced glycation end products (AGEs) are naturally occurring macromolecules that are formed in vivo by the non-enzymatic modification of proteins, lipids, or nucleic acids by sugar, even in the absence of hyperglycemia. In the diet, AGEs are found in animal products, and additional AGEs are produced when those foods are cooked at high temperatures. Studies have linked AGEs to various age-related physiological changes, including wrinkles, diabetic complications, and neurodegenerative disease, including Alzheimer’s disease. Dietary berry fruits have been shown to reduce the severity or slow the progression of many physiological changes and disease pathologies that accompany aging. Emerging evidence has shown that the phytochemicals found in berry fruits exhibit anti-glycative activity. In this review, we briefly summarize the current evidence supporting the neuroprotective anti-glycative activity of berry fruits and their potential to preserve cognitive function during aging.     

Prognostic Value of Tumor Budding in Early-Stage Cervical Adenocarcinomas

Background: Tumor budding has recently been reported as an independent adverse prognostic factor for colorectal adenocarcinomas and other types of carcinoma in the digestive tract. This study aimed to evaluate the prognostic value of tumor budding in patients with early-stage cervical adenocarcinomas and any associations with other clinical and pathological features. Methods: Histological slides of patients with early-stage (IB-IIA) usual-type endocervical adenocarcinoma who underwent radical hysterectomy and pelvic lymph node dissection, without preoperative chemotherapy, between January 2006 and December 2012 were reviewed. Tumor budding was evaluated in routinely-stained sections and defined as detached single cells or clusters of fewer than 5 cells in a tumor invasive front and was stratified based on the number of bud counts in 10-high-power fields as low (follow-up outcomes were assessed. Results: Of 129 patients, a high tumor bud count was observed in 15 (11.6%), positively associated with histologic grade 3 (p<0.001), invasive pattern C (Silva System) (p=0.004), lymph node metastasis (p=0.008), stage IB2-IIA (p=0.016), and tumor size >2 cm (p=0.036). Kaplan-Meyer analysis showed a significant decrease in both disease-free survival and cancer-specific survival for patients with a high tumor bud count (p=0.027 and 0.031, respectively). On multivariate analysis, histologic grade 3 was the only independent predictor for decreased disease-free survival (p=0.004) and cancer-specific survival (p=0.003). Conclusions: A high tumor budding count based on assessment of routinely-stained sections was found to be associated with decreased disease-free and cancer-specific survival in patients with early-stage cervical adenocarcinomas. However, it was not found to be an independent prognostic predictor in this study.     

Generation and preclinical evaluation of a DENV-1/2 prM + E chimeric live attenuated vaccine candidate with enhanced prM cleavage

In the absence of a vaccine or sustainable vector control measures, illnesses caused by dengue virus infection remain an important public health problem in many tropical countries. During the export of dengue virus particles, furin-mediated cleavage of the prM envelope protein is usually incomplete, thus generating a mixture of immature, partially mature and mature extracellular particles. Variations in the arrangement and conformation of the envelope proteins among these particles may be associated with their different roles in shaping the antibody response. In an attempt to improve upon live, attenuated dengue vaccine approaches, a mutant chimeric virus, with enhanced prM cleavage, was generated by introducing a cleavage-enhancing substitution into a chimeric DENV-1/2 virus genome, encoding the prM + E sequence of a recent DENV-1 isolate under an attenuated DENV-2 genetic background. A modest increase in virus specific infectivity observed in the mutant chimeric virus affected neither the attenuation phenotype, when assessed in the suckling mouse neurovirulence model, nor multiplication in mosquitoes. The two chimeric viruses induced similar levels of anti-DENV-1 neutralizing antibody response in mice and rhesus macaques, but more efficient control of viremia during viral challenge was observed in macaques immunized with the mutant chimeric virus. These results indicate that the DENV-1/2 chimeric virus, with enhanced prM cleavage, could be useful as an alternative live, attenuated vaccine candidate for further tests in humans.     

Biomimetic scaffolds and dynamic compression enhance the properties of chondrocyte‐ and MSC‐based tissue‐engineered cartilage

Adult chondrocytes are surrounded by a protein‐ and glycosaminoglycan‐rich extracellular matrix and are subjected to dynamic mechanical compression during daily activities. The extracellular matrix and mechanical stimuli play an important role in chondrocyte biosynthesis and homeostasis. In this study, we aimed to develop scaffold and compressive loading conditions that mimic the native cartilage micro‐environment and enable enhanced chondrogenesis for tissue engineering applications. Towards this aim, we fabricated porous scaffolds based on silk fibroin (SF) and SF with gelatin/chondroitin sulfate/hyaluronate (SF‐GCH), seeded the scaffolds with either human bone marrow mesenchymal stromal cells (BM‐MSCs) or chondrocytes, and evaluated their performance with and without dynamic compression. Human chondrocytes derived from osteoarthritic joints and BM‐MSCs were seeded in scaffolds, precultured for 1 week, and subjected to compression with 10% dynamic strain at 1 Hz, 1 hr/day for 2 weeks. When dynamic compression was applied, chondrocytes significantly increased expression of aggrecan (ACAN) and collagen X (COL10A1) up to fivefold higher than free‐swelling controls. In addition, dynamic compression dramatically improved the chondrogenesis and chondrocyte biosynthesis cultured in both SF and SF‐GCH scaffolds evidenced by glycosaminoglycan (GAG) content, GAG/DNA ratio, and immunostaining of collagen type II and aggrecan. However, both chondrocytes and BM‐MSCs cultured in SF‐GCH scaffolds under dynamic compression showed higher GAG content and compressive modulus than those in SF scaffolds. In conclusion, the micro‐environment provided by SF‐GCH scaffolds and dynamic compression enhances chondrocyte biosynthesis and matrix accumulation, indicating their potential for cartilage tissue engineering applications.     

PCR-ELISA for diagnosis of Trypanosoma evansi in animals and vector

A highly sensitive and specific polymerase chain reaction (PCR) based assay for the detection of Trypanosoma evansi present in the blood of different animals and vector was developed. A simple lysis method was used to remove of the red blood cells to facilitate direct input of samples into the PCR reactions. The primer set was designed and synthesized to amplify a single band of 257 bp PCR product that was subsequently examined by enzyme-linked immunosorbent assay (ELISA). The sensitivity limit of PCR-ELISA was 0.01 pg that was corresponded to 1 parasite/ml of blood. No cross-reactivity of the assay was observed against Babesia bovis, B. bigemina, Anaplasma marginale,Theileria sp. and host DNA. The PCR-ELISA was shown to detect 33 samples of T. evansi infected blood of animals and 10 mosquitoes from different geographical area in Thailand. The results were corresponded to those of the PCR and mouse inoculation. This implies that the technique of PCR-ELISA is not only beneficial for diagnosis of the parasite but also useful for epidemiological study and designing rational trypanosomiasis control program.