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Fulltext Molecular Characterization and Gene Expression of Glutathione Peroxidase 1 in Tor tambroides Exposed to Temperature Stress

Do TD, Thi Mai N, Duy Khoa TN, Abol-Munafi AB, Liew HJ, Kim CB, et al.

Evol Bioinform Online, 2019;15:1176934319853580.
PMID: 31236006 DOI: 10.1177/1176934319853580

Temperature is an abiotic factor that affects various biological and physiological processes in fish. Temperature stress is known to increase the production of reactive oxygen species (ROS) that subsequently cause oxidative stress. Fish is known to evolve a system of antioxidant enzymes to reduce ROS toxicology. Glutathione peroxidase (GPx) family consists of key enzymes that protect fish from oxidative stress. In this study, full-length GPx1 cDNA (GenBank accession no. KY984468) of Tor tambroides was cloned and characterized by rapid amplification of cDNA ends (RACE). The 899-base-pair (bp) GPx1 cDNA includes a 576-bp open reading frame encoding for 191 amino acids, plus 28 bp of 5'-untranslated region (UTR) and 295 bp of 3'-UTR. Homology analysis revealed that GPx1 of T tambroides (Tor-GPx1) shared high similarity with GPx1 sequences of other fish species. The phylogenetic construction based on the amino acid sequence showed that Tor-GPx1 formed a clade with GPx1 sequences of various fish species. Real-time polymerase chain reaction (PCR) was performed to assess the levels of GPx1 gene expression in the liver and muscle of T tambroides under thermal stress. The results indicated that GPx1 gene expression was down-regulated under decreased temperature. However, there was no significant difference between GPx1 gene expression in fish exposed to high temperature and control. Our study provides the first data regarding GPx gene expression in T tambroides under thermal stress.

Matched MeSH terms: Temperature
Immigrant Health Study. 5. Faecal pathogens in foreign workers. [Abstract]

Suresh K, Rajah S, Khairul Anuar A, Anuar Zaini MZ, Saminathan R, Ramakrishnan S

JUMMEC, 1998;3:62-63.

One hundred seventy three stool samples were obtained from workers from Indonesia, Bangladesh, Myanmar, Pakistan and others. The stool samples were examined for Ascaris, Trichuris, Hookworm, Schistosomes, trematodes and cestodes. The protozaon parasites included Bnlantidiirrir coli, Blastocystis honlinis, Cyclospora cryptosporidium, Microsporidiirin, Entamoeeba histolytica, Giardia lamblia, lodamoeba butschilli. Of these 21.9%, 17% and 1% of the population studied had hookworm, Trichuris trichiura and Ascaris lumbricoides infections respectively. There was only one Indonesian reported to have Hymenolepis nana infections. The most common protozoan seen in the faecal sample is Blastocystis hominis (36%) followed by Giardia lamblia (4%). Most of the stools positive with these faecal pathogens were semisolid especially the ones positive for the protozoan. We have also shown Blastocystis from the Indonesian workers show very small forms almost 3-5 in size compared to the normal size of 10-15 pm in the other nationalities. These forms show a distinct growth profile in cultures and appears to be more resistant to temperature changes than Blastocystis seen in the other two nationalities. The high incidence of Hookworm and Trichuris infections is suggestive that if these workers are left unheated their productivity will be hampered by other possible serious complications such as anaemia, weight loss, abdominal pain with diarrhoea1 stools and nausea. There are increasing reports that Blastocystis hominis is pathogenic. Flatulence, abdominal discomfort and the increase in the frequency of the passing watery stool has been noted in patients infected with the parasite. Since most of the workers are generally housed in crowded rooms it is highly likely that this will facilitate transmission through the faecal-oral route of both Giardia and Blastocystis possibly increasing the incidences of these infections among workers.

Matched MeSH terms: Temperature
Entrapment of porous cross-linked enzyme aggregates of maltogenic amylase from Bacillus lehensis G1 into calcium alginate for maltooligosaccharides synthesis

Nawawi NN, Hashim Z, Rahman RA, Murad AMA, Bakar FDA, Illias RM

Int J Biol Macromol, 2020 May 01;150:80-89.
PMID: 32035147 DOI: 10.1016/j.ijbiomac.2020.02.032

Maltooligosaccharides (MOSs) are emerging oligosaccharides in food-based applications and can be synthesized through the enzymatic synthesis of maltogenic amylase from Bacillus lehensis G1 (Mag1). However, the lack of enzyme stability makes this approach unrealistic for industrial applications. The formation of cross-linked enzyme aggregates (CLEAs) is a promising tool for improving enzyme stability, and the substrate accessibility problem of CLEA formation was overcome by the addition of porous agents to generate porous CLEAs (p-CLEAs). However, p-CLEAs exhibited high enzyme leaching and low solvent tolerance. To address these problems, p-CLEAs of Mag1 (Mag1-p-CLEAs) were entrapped in calcium alginate beads (CA). Mag1-p-CLEAs-CA prepared with 2.5% (w/v) sodium alginate and 0.6% (w/v) calcium chloride yielded 53.16% (17.0 U/mg) activity and showed a lower deactivation rate and longer half-life than those of entrapped free Mag1 (Mag1-CA) and entrapped non-porous Mag1-CLEAs (Mag1-CLEAs-CA). Moreover, Mag1-p-CLEAs-CA exhibited low enzyme leaching and high tolerance in various solvents compared to Mag1-p-CLEAs. A kinetic study revealed that Mag1-p-CLEAs-CA exhibited relatively high affinity towards beta-cyclodextrin (β-CD) (Km = 0.62 mM). MOSs (300 mg/g) were synthesized by Mag1-p-CLEAs-CA at 50 °C. Finally, the reusability of Mag1-p-CLEAs-CA makes them as a potential biocatalyst for the continuous synthesis of MOSs.

Matched MeSH terms: Temperature
Fulltext Zinc oxide from aloe vera extract: two-level factorial screening of biosynthesis parameters

Rasli NI, Basri H, Harun Z

Heliyon, 2020 Jan;6(1):e03156.
PMID: 32042952 DOI: 10.1016/j.heliyon.2020.e03156

Zinc oxide (ZnO) was biosynthesised from aloe vera plant extract. The aloe vera plant extract was used as a reducing agent in biosynthesis process. Green synthesis method was proposed because it is cost effective and environmentally friendly. ZnO was characterised using SEM, EDX, FTIR, and XRD analyses. The antibacterial property was tested against Escherichia coli. The effects of aloe vera volume (2-50) mL, precursor concentration (0.001-0.300) M, reaction time (20 min-48 h), and temperature of the reaction (26-200) °C on ZnO characteristics were investigated and screened using a two-level factorial method. Based on the observation and ANOVA analysis result, precursor concentration was the only significant parameter that affected the production of the ZnO nanoparticles (NPs). The EDX analysis proved the presence of ZnO while the SEM analysis confirmed the average size of ZnO particle size was in the range of (18-618) μm with a rod-shape appearance. The XRD analysis showed that the average crystallite size was 0.452 μm and it was in the hexagonal phase. It was also proven to have antibacterial property against E. coli.

Matched MeSH terms: Temperature
Mitigation of 3-MCPD esters and glycidyl esters during the physical refining process of palm oil by micro and macro laboratory scale refining

Sim BI, Khor YP, Lai OM, Yeoh CB, Wang Y, Liu Y, et al.

Food Chem, 2020 Oct 30;328:127147.
PMID: 32497897 DOI: 10.1016/j.foodchem.2020.127147

The reduction of the 3-monochloropropane-1,2-diol esters (3-MCPDE) and glycidyl esters (GE) was successfully achieved by the optimization of four processing parameters: phosphoric acid dosage, degumming temperature, bleaching earth dosage, and deodorization temperature by response surface methodology without the need for additional processing steps. The optimized processing conditions were 0.31% phosphoric acid dosage, 50 °C degumming temperature, 3% bleaching earth dosage, and 240 °C deodorization temperature. The optimization resulted in more than 80% and 65% reduction of 3-MCPDE and GE levels, respectively with color and FFA contents maintained in the acceptable range specified by Palm Oil Refiners Association of Malaysia. The optimized refining condition was transferred to macro scale refining units of 1 kg and 3 kg capacities to investigate its successful application during scale-up process.

Matched MeSH terms: Temperature
Influences of Temperature and Ootheca Age on the Life History of the Cockroach Ootheca Parasitoid Aprostocetus hagenowii (Hymenoptera: Eulophidae)

Tee HS, Lee CY

J Econ Entomol, 2017 02 01;110(1):213-220.
PMID: 28028170 DOI: 10.1093/jee/tow287

The influences of ootheca age and temperature on the life history of Aprostocetus hagenowii (Ratzeburg) (Hymenoptera: Eulophidae), a gregarious ootheca parasitoid of the American cockroach Periplaneta americana (L.) (Dictyoptera: Blattidae), were evaluated. Oothecae were incubated at 20, 25, and 30 °C to produce oothecae aged 1-60, 1-40, and 1-30 d old, respectively. Fitness traits (development time, percentage emergence, number of progeny, percentage female progeny, and female body size) of A. hagenowii developing in these different-aged oothecae were determined. For oothecae incubated at 20, 25, and 30 °C, parasitoids successfully developed in oothecae aged up to 50, 30, and 20 d old, which represent 72.9%, 65.9%, and 61.9% of the total embryonic development time of P. americana, respectively, without any changes in their fitness traits. When A. hagenowii from oothecae kept at constant temperatures (20, 25, 30, 32, and 35 °C) were compared, the immature development time (71.0-34.0 d) and adult life span decreased with increasing temperature. No parasitoid emerged at 35 °C. The lower, upper, and optimal temperature-dependent developmental thresholds were 9.5, 34.2, and 31.1 °C, respectively. Thermal constant for total immature development was 666.7 degree-days. Temperature did not affect lifetime realized fecundity and number of oothecae parasitized by females but did influence parasitism activities over time. Sugar-fed females sustained longer periods of high parasitism rates (≥70%) at 20-30 °C (15-30 d) than at 32-35 °C (1-5 d). These results are useful for determining the ootheca age and temperature range optimal for parasitoid rearing and for estimating the effectiveness of biological control by the wasps.

Matched MeSH terms: Temperature
Biomechanics of ant adhesive pads: frictional forces are rate- and temperature-dependent

Federle W, Baumgartner W, Hölldobler B

J Exp Biol, 2004 Jan;207(Pt 1):67-74.
PMID: 14638834

Tarsal adhesive pads enable insects to hold on to smooth plant surfaces. Using a centrifuge technique, we tested whether a "wet adhesion" model of a thin film of liquid secreted between the pad and the surface can explain adhesive and frictional forces in Asian Weaver ants (Oecophylla smaragdina). When forces are acting parallel to the surface, pads in contact with the surface can slide smoothly. Force per unit pad contact area was strongly dependent on sliding velocity and temperature. Seemingly consistent with the effect of a thin liquid film in the contact zone, (1) frictional force linearly increased with sliding velocity, (2) the increment was greater at lower temperatures and (3) no temperature dependence was detected for low-rate perpendicular detachment forces. However, we observed a strong, temperature-independent static friction that was inconsistent with a fully lubricated contact. Static friction was too large to be explained by the contribution of other (sclerotized) body parts. Moreover, the rate-specific increase of shear stress strongly exceeded predictions derived from estimates of the adhesive liquid film's thickness and viscosity. Both lines of evidence indicate that the adhesive secretion alone is insufficient to explain the observed forces and that direct interaction of the soft pad cuticle with the surface ("rubber friction") is involved.

Matched MeSH terms: Temperature
Detection of microleakage around dental restorations: a review

Alani AH, Toh CG

Oper Dent, 1997 Jul-Aug;22(4):173-85.
PMID: 9484158
Matched MeSH terms: Hot Temperature
Temperature differentially regulates the two kisspeptin systems in the brain of zebrafish

Shahjahan M, Kitahashi T, Ogawa S, Parhar IS

Gen Comp Endocrinol, 2013 Nov 1;193:79-85.
PMID: 23899715 DOI: 10.1016/j.ygcen.2013.07.015

Kisspeptins encoded by the kiss1 and kiss2 genes play an important role in reproduction through the stimulation of gonadotropin-releasing hormone (GnRH) secretion by activating their receptors (KissR1 EU047918 and KissR2 EU047917). To understand the mechanism through which temperature affects reproduction, we examined kiss1 and kiss2 and their respective receptor (kissr1 and kissr2) gene expression in the brain of male zebrafish exposed to a low temperature (15°C), normal temperature (27°C), and high temperature (35°C) for 7-days. kiss1 mRNA levels in the brain were significantly increased (2.9-fold) in the low temperature compared to the control (27°C), while no noticeable change was observed in the high temperature conditions. Similarly, kissr1 mRNA levels were significantly increased (1.5-2.2-folds) in the low temperature conditions in the habenula, the nucleus of the medial longitudinal fascicle, oculomotor nucleus, and the interpeduncular nucleus. kiss2 mRNA levels were significantly decreased (0.5-fold) in the low and high temperature conditions, concomitant with kissr2 mRNA levels (0.5-fold) in the caudal zone of the periventricular hypothalamus and the posterior tuberal nucleus. gnrh3 but not gnrh2 mRNA levels were also decreased (0.5-fold) in the low and high temperature conditions. These findings suggest that while the kiss1/kissr1 system is sensitive to low temperature, the kiss2/kissr2 system is sensitive to both extremes of temperature, which leads to failure in reproduction.

Matched MeSH terms: Temperature
Functional properties and utilization of Artocarpus heterophyllus Lam seed starch from new species in China

Zhang Y, Hu M, Zhu K, Wu G, Tan L

Int J Biol Macromol, 2018 Feb;107(Pt B):1395-1405.
PMID: 29017887 DOI: 10.1016/j.ijbiomac.2017.10.001

Jackfruit is now receiving extensive attention as a new source of starch. However, jackfruit seeds are discarded as waste, although they are rich in starch. The functional properties of the starches were investigated from new Chinese jackfruit species. All the starches have a high amylose (26.56-38.34%) with a potential to become functional foods rich in resistant starch. The jackfruit starches varied from trigonal and tetragonal, round to semi-oval/bell shapes and showed significant variations in particle sizes (5.53-14.46μm). These variations led to significant differences in their functional properties, and significant correlations were found in their pasting, thermal, crystal and texture parameters. Hierarchical cluster analysis sorted the samples into three groups of 1) Malaysia 8 (M8) and ZhenZhu (ZZ); 2) Malaysia 2, Malaysia 3 and Malaysia 4, (M2, M3, M4); and 3) Xiangyinsuo 11, Xiangyinsuo 4, Xiangyinsuo 3 and Xiangyinsuo 2 (X11, X4, X3, X2). The first group could be used as food thickening or gelling agents. The second group could be applied in glutinous foods. The third group make them suitable for fillings in confectionery or weaning foods.

Matched MeSH terms: Temperature
Force delivery of NiTi orthodontic arch wire at different magnitude of deflections and temperatures: A finite element study

Razali MF, Mahmud AS, Mokhtar N

J Mech Behav Biomed Mater, 2018 Jan;77:234-241.
PMID: 28954242 DOI: 10.1016/j.jmbbm.2017.09.021

NiTi arch wires are used widely in orthodontic treatment due to its superelastic and biocompatibility properties. In brackets configuration, the force released from the arch wire is influenced by the sliding resistances developed on the arch wire-bracket contact. This study investigated the evolution of the forces released by a rectangular NiTi arch wire towards possible intraoral temperature and deflection changes. A three dimensional finite element model was developed to measure the force-deflection behavior of superelastic arch wire. Finite element analysis was used to distinguish the martensite fraction and phase state of arch wire microstructure in relation to the magnitude of wire deflection. The predicted tensile and bending results from the numerical model showed a good agreement with the experimental results. As contact developed between the wire and bracket, binding influenced the force-deflection curve by changing the martensitic transformation plateau into a slope. The arch wire recovered from greater magnitude of deflection released lower force than one recovered from smaller deflection. In contrast, it was observed that the plateau slope increased from 0.66N/mm to 1.1N/mm when the temperature was increased from 26°C to 46°C.

Matched MeSH terms: Temperature
Fulltext A response surface approach on hydrolysis condition of eel (Monopterus Sp.) protein hydrolysate with antioxidant activity

Halim, N. R. A., Sarbon, N. M.

International Food Research Journal, 2017;24(3):1081-1093.
MyJurnal

The study aims to determine the optimized condition of eel protein hydrolysate (EPH)
produced using alcalase. The proximate compositions of eel flesh were determined as well.
Enzymatic hydrolysis conditions were optimized using response surface methodology (RSM)
by applying four factors, 3-levels Central Composite Design (CCD) with six centre points. The
model equation was proposed with regards to the time (60min, 120min, 180min), temperature
(40°C, 50°C, 60°C), pH (7, 8, 9) and enzyme concentration (1%, 2%, 3%). The optimum of
hydrolysis condition that be suggested to obtain the optimum yield, degree of hydrolysis (DH)
and antioxidant activity were 84.02 min, 50.18°C, pH 7.89 and 2.26% [enzyme]. The predicted
response values using quadratic model were 10.03% for yield, 83.23% for DH and 89.24%
for antioxidant activity. The chemical composition determination showed that the protein
content increased by more than 5-fold (16.88% to 98.53%) while the fat content was decreased
by 96.48% after hydrolysis. Hydrolysis process had significantly increased the amount of
both hydrophilic (serine and threonine) and hydrophobic amino acids (valine, isoleucine,
phenylalanine, methionine) which contributed to the antioxidant activity of hydrolyzed eel
protein. The enzymatic hydrolysis of eel protein had improved the protein content of EPH with
potential as new natural antioxidant.

Matched MeSH terms: Temperature
Fulltext A rapid and sensitive Loop-mediated isothermal amplification assay for detection of pork DNA based on porcine tRNA lys and ATPase 8 genes

Abdullahi, U.F., Igwenagu, E., Aliyu, S., Mu’azu, A., Naim, R., Wan-Taib, W.R.

International Food Research Journal, 2017;24(4):1357-1361.
MyJurnal

This study describes the development of a rapid and sensitive Loop-mediated isothermal
amplification assay for detection of swine DNA in adulterated meat and meat products. The
need to protect consumer’s right to eat foods of their choices, has made it imperative for
researchers to develop efficient means of screening and certification of food products. Six sets
of LAMP primers designed based on porcine tRNA lysine gene and ATPase subunit 8 genes
were used for the assay. Amplification was carried out under constant temperature (630C), using
a simple laboratory water bath. Average time spent in amplification and detection of results was
25 min. All results were visually detected and confirmed by electrophoresis. Detection limit of
the assay was 0.03 femtogram (fg) much high than the PCR assay, and detection probability of
the assay was 100%. Detection of 0.5% of pork spiked with 99.5% of cattle beef is indicative
of the sensitivity and robustness of the assay. This could serve as a prototype for development
of a sensitive and inexpensive Swine DNA LAMP detection kit.

Matched MeSH terms: Temperature
Functional Properties of Partially Characterized Polysaccharide from the Medicinal Mushroom Ganoderma neo-japonicum (Agaricomycetes)

Subramaniam S, Raman J, Sabaratnam V, Heng CK, Kuppusamy UR

Int J Med Mushrooms, 2017;19(10):849-859.
PMID: 29256840 DOI: 10.1615/IntJMedMushrooms.2017024355

This study was conducted to evaluate the mycochemical composition and antiglycemic and antioxidant activities of Ganoderma neo-japonicum hot aqueous extracts, prepared at different boiling durations, and polysaccharides isolated from them. Ground basidiocarps of G. neo-japonicum were double-boiled at 100°C for 0.5, 3, or 4 hours, and the antiglycemic activity was assessed by α-amylase and α-glucosidase enzyme inhibition assays. The antioxidant capacity of the crude hot aqueous extracts (AE-1, AE-2, AE-3) was assessed by DPPH and ABTS radical scavenging and ferric-reducing antioxidant power assays. The total phenolics, protein, and sugar in the crude extracts were also determined. The hot aqueous extract (AE-3) containing a significant amount of total sugar and having enhanced antiglycemic and antioxidant activities was selected for polysaccharide isolation. The isolated crude polysaccharide was separated and purified using diethylaminoethyl-cellulose-52 and Sepharose 6B column chromatography. Fourier transform infrared spectroscopy studies of the purified polysaccharide fraction (PF) showed the presence of typical bands corresponding to polysaccharides. The estimated β-glucan concentration in the PF was 39.26%. In general, the PF exhibited significantly lower antioxidant activity than AE-3. Nevertheless, its potency in inhibiting carbohydratehydrolyzing enzymes may have potential in the management of diabetes mellitus.

Matched MeSH terms: Hot Temperature
Fulltext Improved In Vivo Efficacy of Anti-Hypertensive Biopeptides Encapsulated in Chitosan Nanoparticles Fabricated by Ionotropic Gelation on Spontaneously Hypertensive Rats

Auwal SM, Zarei M, Tan CP, Basri M, Saari N

Nanomaterials (Basel), 2017 Dec 02;7(12).
PMID: 29207480 DOI: 10.3390/nano7120421

Recent biotechnological advances in the food industry have led to the enzymatic production of angiotensin I-converting enzyme (ACE)-inhibitory biopeptides with a strong blood pressure lowering effect from different food proteins. However, the safe oral administration of biopeptides is impeded by their enzymatic degradation due to gastrointestinal digestion. Consequently, nanoparticle (NP)-based delivery systems are used to overcome these gastrointestinal barriers to maintain the improved bioavailability and efficacy of the encapsulated biopeptides. In the present study, the ACE-inhibitory biopeptides were generated from stone fish (Actinopyga lecanora) protein using bromelain and stabilized by their encapsulation in chitosan (chit) nanoparticles (NPs). The nanoparticles were characterized for in vitro physicochemical properties and their antihypertensive effect was then evaluated on spontaneously hypertensive rats (SHRs). The results of a physicochemical characterization showed a small particle size of 162.70 nm, a polydispersity index (pdi) value of 0.28, a zeta potential of 48.78 mV, a high encapsulation efficiency of 75.36%, a high melting temperature of 146.78 °C and an in vitro sustained release of the biopeptides. The results of the in vivo efficacy indicated a dose-dependent blood pressure lowering effect of the biopeptide-loaded nanoparticles that was significantly higher (p < 0.05) compared with the un-encapsulated biopeptides. Moreover, the results of a morphological examination using transmission electron microscopy (TEM) demonstrated the nanoparticles as homogenous and spherical. Thus, the ACE-inhibitory biopeptides stabilized by chitosan nanoparticles can effectively reduce blood pressure for an extended period of time in hypertensive individuals.

Matched MeSH terms: Temperature
Efficient conversion of lignocellulosic biomass to levulinic acid using acidic ionic liquids

Khan AS, Man Z, Bustam MA, Nasrullah A, Ullah Z, Sarwono A, et al.

Carbohydr Polym, 2018 Feb 01;181:208-214.
PMID: 29253965 DOI: 10.1016/j.carbpol.2017.10.064

In the present research work, dicationic ionic liquids, containing 1,4-bis(3-methylimidazolium-1-yl) butane ([C4(Mim)2]) cation with counter anions [(2HSO4)(H2SO4)0], [(2HSO4)(H2SO4)2] and [(2HSO4)(H2SO4)4] were synthesised. ILs structures were confirmed using 1H NMR spectroscopy. Thermal stability, Hammett acidity, density and viscosity of ILs were determined. Various types of lignocellulosic biomass such as rubber wood, palm oil frond, bamboo and rice husk were converted into levulinic acid (LA). Among the synthesized ionic liquids, [C4(Mim)2][(2HSO4)(H2SO4)4] showed higher % yield of LA up to 47.52 from bamboo biomass at 110°C for 60min, which is the better yield at low temperature and short time compared to previous reports. Surface morphology, surface functional groups and thermal stability of bamboo before and after conversion into LA were studied using SEM, FTIR and TGA analysis, respectively. This one-pot production of LA from agro-waste will open new opportunity for the conversion of sustainable biomass resources into valuable chemicals.

Matched MeSH terms: Temperature
Emulsifying conditions and processing parameters optimisation of kenaf seed oil-in-water nanoemulsions stabilised by ternary emulsifier mixtures

Cheong AM, Tan CP, Nyam KL

Food Sci Technol Int, 2018 Jul;24(5):404-413.
PMID: 29466882 DOI: 10.1177/1082013218760882

Kenaf ( Hibiscus cannabinus L.) seed oil has been proven for its multi-pharmacological benefits; however, its poor water solubility and stability have limited its industrial applications. This study was aimed to further improve the stability of pre-developed kenaf seed oil-in-water nanoemulsions by using food-grade ternary emulsifiers. The effects of emulsifier concentration (1, 5, 10, 15% w/w), homogenisation pressure (16,000, 22,000, 28,000 psi), and homogenisation cycles (three, four, five cycles) were studied to produce high stability of kenaf seed oil-in-water nanoemulsions using high pressure homogeniser. Generally, results showed that the emulsifier concentration and homogenisation conditions had great effect ( p

Matched MeSH terms: Hot Temperature
Effect of storage temperature on the stability of spray dried bacteriophage powders

Leung SSY, Parumasivam T, Nguyen A, Gengenbach T, Carter EA, Carrigy NB, et al.

Eur J Pharm Biopharm, 2018 Jun;127:213-222.
PMID: 29486303 DOI: 10.1016/j.ejpb.2018.02.033

This study aimed to assess the robustness of using a spray drying approach and formulation design in producing inhalable phage powders. Two types of Pseudomonas phages, PEV2 (Podovirus) and PEV40 (Myovirus) in two formulations containing different amounts of trehalose (70% and 60%) and leucine (30% and 40%) were studied. Most of the surface of the produced powders was found to be covered in crystalline leucine. The powders were stored at 4 °C and 20 °C under vacuum. The phage stability and in vitro aerosol performance of the phage powders were examined on the day of production and after 1, 3 and 12 months of storage. A minor titer loss during production was observed for both phages (0.2-0.8 log10 pfu/ml). The storage stability of the produced phage powders was found to be phage and formulation dependent. No further reduction in titer occurred for PEV2 powders stored at 4 °C across the study. The formulation containing 30% leucine maintained the viability of PEV2 at 20 °C, while the formulation containing 40% leucine gradually lost titer over time with a storage reduction of ∼0.9 log10 pfu/ml measured after 12 months. In comparison, the PEV40 phage powders generally had a ∼ 0.5 log10 pfu/ml loss upon storage regardless of temperature. When aerosolized, the total in vitro lung doses of PEV2 were of the order of 107 pfu, except the formulation containing 40% leucine stored at 20 °C which had a lower lung dose. The PEV40 powders also had lung doses of 106-107 pfu. The results demonstrate that spray dried Myoviridae and Podoviridae phage in a simple formulation of leucine and trehalose can be successfully stored for one year at 4 °C and 20 °C with vacuum packaging.

Matched MeSH terms: Temperature
Fulltext Kinetics and Optimization of Lipophilic Kojic Acid Derivative Synthesis in Polar Aprotic Solvent Using Lipozyme RMIM and Its Rheological Study

Ishak N, Lajis AFB, Mohamad R, Ariff AB, Mohamed MS, Halim M, et al.

Molecules, 2018 Feb 24;23(2).
PMID: 29495254 DOI: 10.3390/molecules23020501

The synthesis of kojic acid derivative (KAD) from kojic and palmitic acid (C16:0) in the presence of immobilized lipase from Rhizomucor miehei (commercially known as Lipozyme RMIM), was studied using a shake flask system. Kojic acid is a polyfunctional heterocycles that acts as a source of nucleophile in this reaction allowing the formation of a lipophilic KAD. In this study, the source of biocatalyst, Lipozyme RMIM, was derived from the lipase of Rhizomucor miehei immobilized on weak anion exchange macro-porous Duolite ES 562 by the adsorption technique. The effects of solvents, enzyme loading, reaction temperature, and substrate molar ratio on the reaction rate were investigated. In one-factor-at-a-time (OFAT) experiments, a high reaction rate (30.6 × 10-3 M·min-1) of KAD synthesis was recorded using acetone, enzyme loading of 1.25% (w/v), reaction time of 12 h, temperature of 50 °C and substrate molar ratio of 5:1. Thereafter, a yield of KAD synthesis was optimized via the response surface methodology (RSM) whereby the optimized molar ratio (fatty acid: kojic acid), enzyme loading, reaction temperature and reaction time were 6.74, 1.97% (w/v), 45.9 °C, and 20 h respectively, giving a high yield of KAD (64.47%). This condition was reevaluated in a 0.5 L stirred tank reactor (STR) where the agitation effects of two impellers; Rushton turbine (RT) and pitch-blade turbine (PBT), were investigated. In the STR, a very high yield of KAD synthesis (84.12%) was achieved using RT at 250 rpm, which was higher than the shake flask, thus indicating better mixing quality in STR. In a rheological study, a pseudoplastic behavior of KAD mixture was proposed for potential application in lotion formulation.

Matched MeSH terms: Temperature
Stability of dobutamine in continuous ambulatory delivery devices

Al Madfai F, Valah B, Zaidi STR, Wanandy T, Ming LC, Peterson GM, et al.

J Clin Pharm Ther, 2018 Aug;43(4):530-535.
PMID: 29500838 DOI: 10.1111/jcpt.12674

WHAT IS KNOWN AND OBJECTIVE: Continuous infusion of dobutamine plays an important role in the management of patients with end-stage heart failure. Home infusion of dobutamine using a continuous ambulatory delivery device (CADD) facilitates the management of patients in their home, avoiding complications associated with long-term hospitalization. However, the stability of dobutamine in CADD is currently unknown. Therefore, this study investigated the physicochemical stability of dobutamine in CADDs at three different temperatures over various time points.
METHODS: Six CADDs (three containing dobutamine 10 mg/mL in 0.9% sodium chloride and three containing dobutamine 10 mg/mL in 5% glucose) were prepared and stored at 4°C for 7 days, followed by 12 hours at 35°C and then for another 12 hours at 25°C. An aliquot (n = 3) was withdrawn aseptically at 0, 24, 48, 72, 96, 120, 144 and 168 hours when stored at 4°C, and at 0, 6 and 12 hours when stored at the other two temperatures. Each sample was analysed for dobutamine concentration using a stability-indicating high-performance liquid chromatography. All the samples were also evaluated for change in pH, colour and for particle content.
RESULTS AND DISCUSSION: No evidence of particle formation, colour or pH change was observed throughout the study period. Dobutamine, when admixed with 0.9% sodium chloride or 5% glucose, was found to be chemically stable for at least 168 hours at 4°C and for another 12 hours at 35°C and for another 12 hours at 25°C.
WHAT IS NEW AND CONCLUSIONS: Our findings will allow health professionals to provide a weekly supply of dobutamine-containing CADDs to patients for home infusions. Continuous infusion over a 24-hour period using one CADD per day will also decrease the number of exchanges required and thus reduce the risk of catheter-related bloodstream infections.

Matched MeSH terms: Temperature

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