Power Allocation for Adaptive OFDM Index Modulation in Cooperative Networks

In this paper, we propose a power allocation strategy for the adaptive orthogonal frequency-division multiplexing (OFDM) index modulation (IM) in cooperative networks. The allocation strategy is based on the Karush-Kuhn-Tucker (KKT) conditions, and aims at maximizing the average network capacity according to the instantaneous channel state information (CSI). As the transmit power at source and relay is constrained separately, we can thus formulate an optimization problem by allocating power to active subcarriers. Compared to the conventional uniform power allocation strategy, the proposed dynamic strategy can lead to a higher average network capacity, especially in the low signal-to-noise ratio (SNR) region. The analysis is also verified by numerical results produced by Monte Carlo simulations. By applying the proposed power allocation strategy, the efficiency of adaptive OFDM IM can be enhanced in practice, which paves the way for its implementation in the future, especially for cell-edge communications

Role of cytokines secreted from mast cells act on dengue hemorrhagic fever pathogenesis

Dengue infection is currently a major human health problem across the globe, especially in Thailand. The lack of an effective treatment or vaccine makes research into the pathogenesis and the development of promising important treatments. This study aimed to investigate the quantity and type of cytokines that are secreted from mast cells after dengue infection related to the pathogenesis of human vascular endothelial cells (HUVEC). The study analyzed the quantity of cytokine secretion from human mast cells (HMC-1) compared with monocytic cells (THP-1), after infection with type 2-dengue virus (DENV-2-16681) by high throughput magnetic bead-based Bio-PlexÒassay. The effect of cytokine stimulation from HMC-1 and THP-1 on the HUVEC was determined. The results showed significantly increased levels of cytokines, which were similar to those secreted from Th1 and Th2 including interleukin (IL)-5, IL-8, tumor necrosis factor (TNF)-a, macrophage inflammatory protein (MIP)-1, and granulocyte macrophage colony-stimulating factor (GM-CSF) (p<0.01). However, the study found that there was specificity between cytokine secretions and particular cell types. It was found that TNF-a secretion was higher in THP-1 cells, while IL-5 was found at higher levels in HMC-1 cells after dengue infection. The stimulation of dengue-infected HMC-1 cells on vascular endothelial cells showed a higher secretion of ICAM-1 and VCAM-1 in THP-1 cells. This study concluded that increased secretion of IL-5 from mast cells has an effect on vascular endothelial cells, which is an important step to explain the pathogenesis of dengue. This work may elucidate the role of mast cells in dengue pathogenesis to determine disease severity and development of novel treatments

In Vitro

Growing rates of fungal infections and increasing resistance against standard antifungal drugs can cause serious health problems. There is, therefore, increasing interest in the potential use of medicinal plants as novel antifungal agents. This study investigates the antifungal properties of crude plant extracts from ten medicinal plant species. Crude samples were extracted using the hot water extraction process. The minimum inhibitory concentrations (MIC) and diameter zone of inhibition were determined in each extract against ten fungal strains, and fluconazole was used as a positive control. The cytotoxicity of crude extracts on in vitro human skin fibroblast (HSF) cell models was determined by MTT assay. Of the ten crude extracts, Psidium guajava L. exhibited the highest antifungal activity, diameter zone of inhibition, and percentage HSF cell viability. Although all extracts exhibited antifungal activity, Psidium guajava L. had the greatest potential for developing antifungal treatments

Evaluation of pathogenic microorganisms contaminated in dermatology outpatient clinic during the midst of rainy season

The pathogenic microorganism can be rapidly grown in condition of high humidity, which was a common condition in rainy season and led to cause of diseases especially in immune-compromised patients. Due to most of the patients visited the clinic presented with skin infection caused from pathogenic microorganisms, the scratch and pick out of the scaly residue were always the common patients manner that can spread out of contamination in the clinic. This study aimed to evaluate the contamination of pathogenic microorganisms in dermatology outpatient clinic during the rainy season. Samples were collected from 7 rooms in the dermatology clinic in which 15 spot sampling sites each by using spot test technique and collected 3 times a day (3 hours before clinic opened, 3 hours after clinic opened, and 3 hours after clinic closed). The sample was cultured and determined. The results found that 85% were positive and could be identified as 15% of gram-positive bacteria, 6% of gram-negative bacteria, 24% of yeast, and 55% of mold. This study provided promising information to prevent pathogenic contamination in dermatology outpatient clinic. Hygienic practical routine (effective methods and suitable chemical agents) needs to be encouraged in the clinic in order to decrease the contamination. Moreover, the statistical data of new pathogenic infection in patients should be monitored and compared with other similar dermatology outpatient clinics, which will help to improve human health and minimal the risk of contamination effects

Investigation of the activity of phospholipase, esterase, and hemolysin in Scedosporium apiospermum

Currently, the opportunistic infection from Scedosporium apiospermum has beenincreasing in immunocompromised host, due to this pathogen could be detected in environment. Thus, the study of virulence factors are important for assessment the severity and disease pathogenesis. The aim of this study was to investigate the activity of phospholipase, esterase and hemolysin in S. apiospermum. The activity of phospholipase, esterase and hemolysin performedby simple egg yolk agar, tween 80 opacity test agar and Brain Heart Infusion agar, respectively. The Pz score calculation were performed to analyse the results. This showed the expression of esterase and hemolysin from S. apiospermum. Both of esterase and hemolysin are the virulencefactors, which usually found in Candida albicans and Aspergillus spp. Thus, the study of esterase, hemolysin and phospholipase secretion in S. apiospermum are important for pathogenesis and severity analysis to find out the specific enzyme in the nearly future

A powerful in vivo alternative model in scientific research: Galleria mellonella

Murine models are suggested as the gold standard for scientific research, but they have many limitations of ethical and logistical concern. Then, the alternative host models have been developed to use in many aspects especially in invertebrate animals. These models are selected for many areas of research including genetics, physiology, biochemistry, evolution, disease, neurobiology, and behavior. During the past decade, Galleria mellonella has been used for several medical and scientific researches focusing on human pathogens. This model commonly used their larvae stage due to their easy to use, non-essential special tools or special technique, inexpensive, short life span, and no specific ethical requirement. Moreover, their innate immune response close similarly to mammals, which correlate with murine immunity. In this review, not only the current knowledge of characteristics and immune response of G. mellonella, and the practical use of these larvae in medical mycology research have been presented, but also the better understanding of their limitations has been provided

Antimicrobial activity of nisin on common dermatological pathogens

Environmental changes and lack of proper medical treatments can induce drug resistant microbes including those from dermatological infections. Therefore, alternative and effective treatments against dermatological pathogens from natural resources and herbs become essential. This study aimed to determine a promising nisin treatment as an alternative way for preventing dermatological infections. Nisin from Lactococcus lactis was used for in vitro treating common dermatological pathogens usually found in tropical regions including Trichophyton rubrum, Candida albicans, and Staphylococcus aureus. The results showed that nisin reduced the growth of S. aureus as indicated by ที่ Minimal Inhibitory Concentration and Minimal Bactericidal Concentration (120 and 1,920 μg/ml, respectively). Moreover, 960 μg/ml of nisin was found to reduce the growth of T. rubrum and C. albicans as indicated by MIC. In addition, this concentration of nisin 120 μg/ml did not exhibit any effect on fibroblast cells in vitro. Therefore, this study demonstrated that nisin can be probably used as an alternative therapeutic agent for treating dermal infection caused by common dermatological pathogens

Dengue and Chikungunya Coinfection – The Emergence of an Underestimated Threat

Both Dengue (DENV) and Chikungunya (CHIKV) viruses can be transmitted by Aedes mosquito species and the diseases that they cause have several clinical symptoms in common. Co-circulation of DENV and CHIKV is increasing around the world and must therefore be considered as an emerging threat with an important public health concern. At present, very little is known about the clinical manifestations and biological consequences of coinfection by both viruses. Thus, numerous questions such as clinical severity and dynamics of viral replication of DENV and CHIKV coinfections, as well as vectorial competence, have yet to be addressed in this important and challenging research area. The ensuring knowledge will enhance the clinical surveillance and the development of diagnostic tools able to differentiate DENV and CHIKV in order to early detect virus invasion and local transmission, as well as to improve patient care and timely control measures. In this review, we highlight the current knowledge on DENV and CHIKV coinfections. We also discuss research perspectives and challenges in order to further understand the ecology and biology of this phenomenon

Aedesin : structure and antimicrobial activity against multidrug resistant bacterial strains

Multidrug resistance, which is acquired by both Gram-positive and Gram-negative bacteria, causes infections that are associated with significant morbidity and mortality in many clinical settings around the world. Because of the rapidly increasing incidence of pathogens that have become resistant to all or nearly all available antibiotics, there is a need for a new generation of antimicrobials with a broad therapeutic range for specific applications against infections. Aedesin is a cecropin-like anti-microbial peptide that was recently isolated from dengue virus-infected salivary glands of the Aedes aegypti mosquito. In the present study, we have refined the analysis of its structural characteristics and have determined its antimicrobial effects against a large panel of multidrug resistant bacterial strains, directly isolated from infected patients. Based the results from nuclear magnetic resonance spectroscopy analysis, Aedesin has a helix-bend-helix structure typical for a member of the family of α-helix anti-microbial peptides. Aedesin efficiently killed Gram-negative bacterial strains that display the most worrisome resistance mechanisms encountered in the clinic, including resistance to carbapenems, aminoglycosides, cephalosporins, 4th generation fluoroquinolones, folate inhibitors and monobactams. In contrast, Gram-positive strains were insensitive to the lytic effects of the peptide. The anti-bacterial activity of Aedesin was found to be salt-resistant, indicating that it is active under physiological conditions encountered in body fluids characterized by ionic salt concentrations. In conclusion, because of its strong lytic activity against multidrug resistant Gram-negative bacterial strains displaying all types of clinically relevant resistance mechanisms known today, Aedesin might be an interesting candidate for the development of alternative treatment for infections caused by these types of bacteria

Induction of a Peptide with Activity against a Broad Spectrum of Pathogens in the Aedes aegypti Salivary Gland, following Infection with Dengue Virus

The ultimate stage of the transmission of Dengue Virus (DENV) to man is strongly dependent on crosstalk between the virus and the immune system of its vector Aedes aegypti (Ae. aegypti). Infection of the mosquito's salivary glands by DENV is the final step prior to viral transmission. Therefore, in the present study, we have determined the modulatory effects of DENV infection on the immune response in this organ by carrying out a functional genomic analysis of uninfected salivary glands and salivary glands of female Ae. aegypti mosquitoes infected with DENV. We have shown that DENV infection of salivary glands strongly up-regulates the expression of genes that encode proteins involved in the vector's innate immune response, including the immune deficiency (IMD) and Toll signalling pathways, and that it induces the expression of the gene encoding a putative anti-bacterial, cecropin-like, peptide (AAEL000598). Both the chemically synthesized non-cleaved, signal peptide-containing gene product of AAEL000598, and the cleaved, mature form, were found to exert, in addition to antibacterial activity, anti-DENV and anti-Chikungunya viral activity. However, in contrast to the mature form, the immature cecropin peptide was far more effective against Chikungunya virus (CHIKV) and, furthermore, had strong anti-parasite activity as shown by its ability to kill Leishmania spp. Results from circular dichroism analysis showed that the immature form more readily adopts a helical conformation which would help it to cause membrane permeabilization, thus permitting its transfer across hydrophobic cell surfaces, which may explain the difference in the anti-pathogenic activity between the two forms. The present study underscores not only the importance of DENV-induced cecropin in the innate immune response of Ae. aegypti, but also emphasizes the broad-spectrum anti-pathogenic activity of the immature, signal peptide-containing form of this peptide