Enterovirus 71 (EV71)-associated hand, foot, and mouth disease may be complicated by encephalomyelitis. We investigated EV71 brainstem infection and whether this infection could be ameliorated by passive immunization in a mouse model. Enterovirus 71 was injected into unilateral jaw/facial muscles of 2-week-old mice, and hyperimmune sera were given before or after infection. Harvested tissues were studied by light microscopy, immunohistochemistry, in situ hybridization, and viral titration. In unimmunized mice, viral antigen and RNA were detected within 24 hours after infection only in ipsilateral cranial nerves, motor trigeminal nucleus, reticular formation, and facial nucleus; viral titers were significantly higher in the brainstem than in the spinal cord samples. Mice given preinfection hyperimmune serum showed a marked reduction of ipsilateral viral antigen/RNA and viral titers in the brainstem in a dose-dependent manner. With optimum hyperimmune serum given after infection, brainstem infection was significantly reduced in a time-dependent manner. A delay in disease onset and a reduction of disease severity and mortality were also observed. Thus, EV71 can directly infect the brainstem, including the medulla, via cranial nerves, most likely by retrograde axonal transport. This may explain the sudden cardiorespiratory collapse in human patients with fatal encephalomyelitis. Moreover, our results suggest that passive immunization may still benefit EV71-infected patients who have neurologic complications.
Amidst growing concerns over the spread of antibiotic-resistant Staphylococcus aureus strains, the identification of alternative therapeutic molecules has become paramount. Previously, we utilized a Caenorhabditis elegans-S. aureus screening platform to identify potential anti-infective agents from a collection of natural extracts and synthetic compounds. One of the hits obtained from the screen was the aqueous extract of Orthosiphon stamineus leaves (UE-12) that enhanced the survival of infected nematodes without interfering with bacterial growth. In this study, we used a fluorescent transgenic reporter strain and observed that the repressed expression of the lys-7 defense gene in infected nematodes was restored in the presence of UE-12. Analysis of a selected panel of PMK-1 and DAF-16-regulated transcripts and loss-of-function mutants in these pathways indicates that the protective role of UE-12 is mediated via the p38 MAP kinase and insulin-like signaling pathways. Further analysis of a panel of known bioactive compounds of UE-12 proposed eupatorin (C18H16O7) as the possible candidate active molecule contributing to the anti-infective property of UE-12. Taken together, these findings strongly suggest that the O. stamineus leaf extract is a promising anti-infective agent that confers an advantage in survival against S. aureus infection by modulating the immune response of the infected host.
Novel nanoemulsion-based drug delivery systems (DDS) have been proposed as alternative and effective approach for the delivery of various types of poorly water-soluble drugs in the last decade. This nanoformulation strategy significantly improves the cell uptake and bioavailability of numerous hydrophobic drugs by increasing their solubility and dissolution rate, maintaining drug concentration within the therapeutic range by controlling the drug release rate, and reducing systemic side effects by targeting to specific disease site, thus offering a better patient compliance. To date, cavitation technology has emerged to be an energy-efficient and promising technique to generate such nanoscale emulsions encapsulating a variety of highly potent pharmaceutical agents that are water-insoluble. The micro-turbulent implosions of cavitation bubbles tear-off primary giant oily emulsion droplets to nano-scale, spontaneously leading to the formation of highly uniform drug contained nanodroplets. A substantial body of recent literatures in the field of nanoemulsions suggests that cavitation is a facile, cost-reducing yet safer generation tool, remarkably highlighting its industrial commercial viability in the development of designing novel nanocarriers or enhancing the properties of existing pharmaceutical products. In this review, the fundamentals of nanoemulsion and the principles involved in their formation are presented. The underlying mechanisms in the generation of pharmaceutical nanoemulsion under acoustic field as well as the advantages of using cavitation compared to the conventional techniques are also highlighted. This review focuses on recent nanoemulsion-based DDS development and how cavitation through ultrasound and hydrodynamic means is useful to generate the pharmaceutical grade nanoemulsions including the complex double or submicron multiple emulsions.
The commercial freshwater crayfish Cherax quadricarinatus complete mitochondrial genome was recovered from partial genome sequencing using the MiSeq Personal Sequencer. The mitogenome has 15,869 base pairs consisting of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a non-coding AT-rich region. The base composition of C. quadricarinatus is 32.16% for T, 23.39% for C, 33.26% for A, and 11.19% for G, with an AT bias of 65.42%.
The complete mitochondrial genome of the conservationally significant Macquarie perch (Macquaria australasica) was obtained from low-coverage shotgun sequencing using the MiSeq sequencer. The M. australasica mitogenome has 16,496 base pairs (55% A + T content) made up of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a 819 bp non-coding AT-rich region. This is the first mitogenome sequence for the genus Macquaria, and the third to be reported for the family Percichthyidae.
Glutathione transferases (GST) were purified from locally isolated bacteria, Acinetobacter calcoaceticus Y1, by glutathione-affinity chromatography and anion exchange, and their substrate specificities were investigated. SDS-polyacrylamide gel electrophoresis revealed that the purified GST resolved into a single band with a molecular weight (MW) of 23 kDa. 2-dimensional (2-D) gel electrophoresis showed the presence of two isoforms, GST1 (pI 4.5) and GST2 (pI 6.2) with identical MW. GST1 was reactive towards ethacrynic acid, hydrogen peroxide, 1-chloro-2,4-dinitrobenzene, and trans,trans-hepta-2,4-dienal while GST2 was active towards all substrates except hydrogen peroxide. This demonstrated that GST1 possessed peroxidase activity which was absent in GST2. This study also showed that only GST2 was able to conjugate GSH to isoproturon, a herbicide. GST1 and GST2 were suggested to be similar to F0KLY9 (putative glutathione S-transferase) and F0KKB0 (glutathione S-transferase III) of Acinetobacter calcoaceticus strain PHEA-2, respectively.
The main challenge in microfiltration (MF) is membrane fouling, which leads to a significant decline in permeate flux and a change in membrane selectivity over time. This work aims to elucidate the mechanisms of membrane fouling in cold MF of skim milk by identifying and quantifying the proteins and minerals involved in external and internal membrane fouling. Microfiltration was conducted using a 1.4-μm ceramic membrane, at a temperature of 6±1°C, cross-flow velocity of 6m/s, and transmembrane pressure of 159kPa, for 90min. Internal and external foulants were extracted from a ceramic membrane both after a brief contact between the membrane and skim milk, to evaluate instantaneous adsorption of foulants, and after MF. Four foulant streams were collected: weakly attached external foulants, weakly attached internal foulants, strongly attached external foulants, and strongly attached internal foulants. Liquid chromatography coupled with tandem mass spectrometry analysis showed that all major milk proteins were present in all foulant streams. Proteins did appear to be the major cause of membrane fouling. Proteomics analysis of the foulants indicated elevated levels of serum proteins as compared with milk in the foulant fractions collected from the adsorption study. Caseins were preferentially introduced into the fouling layer during MF, when transmembrane pressure was applied, as confirmed both by proteomics and mineral analyses. The knowledge generated in this study advances the understanding of fouling mechanisms in cold MF of skim milk and can be used to identify solutions for minimizing membrane fouling and increasing the efficiency of milk MF.
Quorum sensing (QS) is a mechanism adopted by bacteria to regulate expression of genes according to population density. N-acylhomoserine lactones (AHLs) are a type of QS signalling molecules commonly found in Gram-negative bacteria which have been reported to play a role in microbial spoilage of foods and pathogenesis. In this study, we isolated an AHL-producing Hafnia alvei strain (FB1) from spherical fish pastes. Analysis via high resolution triple quadrupole liquid chromatography/mass spectrometry (LC/MS) on extracts from the spent supernatant of H. alvei FB1 revealed the existence of two short chain AHLs: N-(3-oxohexanoyl) homoserine lactone (3-oxo-C6-HSL) and N-(3-oxo- octanoyl) homoserine lactone (3-oxo-C8-HSL). To our knowledge, this is the first report of the production of AHLs, especially 3-oxo-C8-HSL, by H. alvei.
Vancomycin has been documented to cause various adverse cutaneous reactions. We present a case report of a man, who developed a large localized erythematous plaque in his forearm following parenteral vancomycin therapy. We believe this to be the first reported case of such cutaneous reaction associated with parenteral vancomycin therapy.
We report a 29-year-old Malay man who had pulmonary manifestations as an initial presentation for systemic lupus erythematosus. He had prolonged hospitalization and was treated with intensive care therapy with immunosuppressants.
Optimisation of protein extraction yield from pinto bean was investigated using response surface methodology. The maximum protein yield of 54.8 mg/g was obtained with the optimal conditions of: temperature=25 °C, time=1 h and buffer-to-sample ratio=20 ml/g. PBPI was found to obtain high amount of essential amino acids such as leucine, lysine, and phenylalanine compared to SPI. The predominant proteins of PBPI were vicilin and phytohemagglutinins whereas the predominant proteins of SPI were glycinin and conglycinins. Significantly higher emulsifying capacity was found in PBPI (84.8%) compared to SPI (61.9%). Different isoelectric points were found in both PBPI (4.0-5.5) and SPI (4.0-5.0). Also, it was found that PBPI obtained a much higher denaturation temperature of 110.2 °C compared to SPI (92.5 °C). Other properties such as structural information, gelling capacity, water- and oil-holding capacities, emulsion stability as well as digestibility were also reported.
Topical keratolytic agents such as benzoyl peroxide (BP) and salicylic acid (SA) are one of the common treatments for inflammatory skin diseases. However, the amount of drug delivery through the skin is limited due to the stratum corneum. The purposes of this study were to investigate the ability of fish oil to act as penetration enhancer for topical keratolytic agents and to determine the suitable gelator for formulating stable fish oil oleogels. 2 types of gelling agents, beeswax and sorbitan monostearate (Span 60), were used to formulate oleogels. To investigate the efficacy of fish oil oleogel permeation, commercial hydrogels of benzoyl peroxide (BP) and salicylic acid (SA) were used as control, and comparative analysis was performed using Franz diffusion cell. Stability of oleogels was determined by physical assessments at 20°C and 40°C storage. Benzoyl peroxide (BP) fish oil oleogels containing beeswax were considered as better formulations in terms of drug permeation and cumulative drug release. All the results were found to be statistically significant (p<0.05, ANOVA) and it was concluded that the beeswax-fish oil combination in oleogel can prove to be beneficial in terms of permeation across the skin and stability.
The emulsification-evaporation method was used to prepare astaxanthin nanodispersions using a three-component emulsifier system composed of Tween 20, sodium caseinate and gum Arabic. Using Response-surface methodology (RSM), we studied the main and interaction effects of the major emulsion components, namely, astaxanthin concentration (0.02-0.38 wt %, x1), emulsifier concentration (0.2-3.8 wt %, x2) and organic phase (dichloromethane) concentration (2-38 wt %, x3) on nanodispersion characteristics. The physicochemical properties considered as response variables were: average particle size (Y1), PDI (Y2) and astaxanthin loss (Y3).
This study aimed to establish, as a proof of concept, whether bacterial cellulose (BC)-derived plant cell wall models could be used to investigate foodborne bacterial pathogen attachment. Attachment of two strains each of Salmonella enterica and Listeria monocytogenes to four BC-derived plant cell wall models (namely, BC, BC-pectin [BCP], BC-xyloglucan [BCX], and BC-pectin-xyloglucan [BCPX]) was investigated. Chemical analysis indicated that the BCPX composite (31% cellulose, 45.6% pectin, 23.4% xyloglucan) had a composition typical of plant cell walls. The Salmonella strains attached in significantly (p<0.05) higher numbers (~6 log colony-forming units [CFU]/cm(2)) to the composites than the Listeria strains (~5 log CFU/cm(2)). Strain-specific differences were also apparent with one Salmonella strain, for example, attaching in significantly (p<0.05) higher numbers to the BCX composite than to the other composites. This study highlights the potential usefulness of these composites to understand attachment of foodborne bacteria to fresh produce.
Plasmid vaccination is a smart gene delivery application mostly achieved through the utilisation of viral or copolymeric systems as surrogated carriers in micro or nano formulations. A common polymeric protocol for plasmid vaccine formulation, which as somewhat been successful, is via the complexation of the DNA molecules with a cationic polymer, and encapsulating in a vehicular carrier polymer. Even though plasmid vaccination research has not witnessed the much anticipated success, due a number of cellular and physicochemical reasons, application of copolymeric carriers with tight functionalities is a promising strategy to optimally deliver the DNA molecules; in view of the available chemistries and physical properties that could be tuned to enable enhanced targeted delivery, uptake and specific transfection. This also enables the targeting of specific epitopes and antigen presenting cells for the treatment of many pathogenic infections and cancer. This paper provides a brief critical review of the current state of plasmid vaccines formulation and molecular delivery with analysis of performance data obtained from clinical trials.
Primary lacrimal sac lymphoma is rare. The common clinical features are epiphora and medial canthal swelling which mimic nasolacrimal duct obstruction. Histological examination is therefore important to avoid delay in diagnosis and treatment. We report a case of primary lacrimal sac lymphoma in a 72-year-old female who developed a metachronous tumour at the hard palate one year after excision of the lacrimal sac tumour.
The increasing popularity and widespread use of traditional Chinese herbs as alternative medicine have sparked an interest in understanding their biosafety, especially in decoctions that are consumed. This study aimed to assess the level of microbial and heavy metal contamination in commonly consumed herbal medicine in Malaysia and the effects of boiling on these contamination levels.
OBJECTIVE: In this study, 218 national drug rehabilitation center helpers in Malaysia were surveyed regarding perceptions of their on-the-job clinical supervision needs and preferred supervisor roles and emphasis areas in their supervision sessions.
METHODS: Descriptive analyses were conducted.
RESULTS: Findings suggest that drug rehabilitation center helpers in Malaysia expressed high level of on-the-job supervision needs. In addition, professional behavior skills were found to be the most desirable supervisory area followed by process, conceptualization, and personalization skills.
CONCLUSIONS: Implications for providing clinical supervision for drug rehabilitation center helpers in Malaysia were discussed, along with suggestions for future research.
Utilization of macroalgae biomass for bioethanol production appears as an alternative source to lignocellulosic materials. In this study, for the first time, Amberlyst (TM)-15 was explored as a potential catalyst to hydrolyze carbohydrates from Eucheuma cottonii extract to simple reducing sugar prior to fermentation process. Several important hydrolysis parameters were studied for process optimization including catalyst loading (2-5%, w/v), reaction temperature (110-130°C), reaction time (0-2.5 h) and biomass loading (5.5-15.5%, w/v). Optimum sugar yield of 39.7% was attained based on the following optimum conditions: reaction temperature at 120°C, catalyst loading of 4% (w/v), 12.5% (w/v) of biomass concentration and reaction time of 1.5h. Fermentation of the hydrolysate using Saccharomyces cerevisiae produced 0.33 g/g of bioethanol yield with an efficiency of 65%. The strategy of combining heterogeneous-catalyzed hydrolysis and fermentation with S. cerevisiae could be a feasible strategy to produce bioethanol from macroalgae biomass.