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Chloroquine polymeric membrane electrodes: Development and applications

Saad B, Kanapathy K, Ahmad MN, Hussin AH, Ismail Z

Talanta, 1991 Dec;38(12):1399-402.
PMID: 18965315

Three main types of PVC solvent polymeric membrane ion-selective electrodes for chloroquine are described. They are based on three ion-pairing agents namely dipicrylamine (DPA), tetraphenylborate (TPB) or tetrakis(4-chlorophenyl)borate (TCPB) with either dioctylphenyl phosphonate (DOPP) or trioctyl phosphate (TOP) solvent mediator. All electrodes exhibit Nernstian responses, fast dynamic response times and a wide useful pH range. The best all-round electrode is based on TPB and TOP plasticizing solvent mediators with a limit of detection of 7.1 x 10(-6)M and was utilized for the assay of chloroquine in tablets. Direct potentiometric determinations with either the analyte addition method or the normal calibration method gave results comparable to the official method.

Matched MeSH terms: Phosphates
Isolation and characterization of a mo -reducing bacterium

Ghani B, Takai M, Hisham NZ, Kishimoto N, Ismail AK, Tano T, et al.

Appl Environ Microbiol, 1993 Apr;59(4):1176-80.
PMID: 16348915

A Mo -reducing bacterium (strain 48), which grew on medium supplemented with 200 mM Mo, was isolated from stream water obtained from Chengkau, Malaysia. The chemical properties of strain 48 conform to the characteristics of Enterobacter cloacae. Under anaerobic conditions in the glucose-yeast extract medium containing phosphate ion (2.9 mM) and Mo (10 mM), the bacterium reduced Mo to form molybdenum blue. Approximately 27% of Mo added to the medium was reduced after 28 h of cultivation. The reduction of Mo with glucose as an electron donor was strongly inhibited by iodoacetic acid, sodium fluoride, and sodium cyanide, suggesting an involvement of the glycolytic pathway and electron transport in Mo reduction. NADH and N,N,N',N' -tetramethyl-p-phenylenediamine served as electron donors for Mo reduction. When NADH was used as an electron donor, at first cytochrome b in the cell extract was reduced, and then molybdenum blue was formed. Sodium cyanide strongly inhibited Mo reduction by NADH (5 mM) but not the reduction of cytochrome b in the cell extract, suggesting that the reduced component of the electron transport system after cytochrome b serves as an electron donor for Mo reduction. Both ferric and stannous ions strongly enhanced the activity of Mo reduction by NADH.

Matched MeSH terms: Phosphates
Fulltext Purification and biochemical characterization of recombinant Persicaria minor β-sesquiphellandrene synthase

Ker DS, Pang SL, Othman NF, Kumaran S, Tan EF, Krishnan T, et al.

PeerJ, 2017;5:e2961.
PMID: 28265494 DOI: 10.7717/peerj.2961

BACKGROUND: Sesquiterpenes are 15-carbon terpenes synthesized by sesquiterpene synthases using farnesyl diphosphate (FPP) as a substrate. Recently, a sesquiterpene synthase gene that encodes a 65 kDa protein was isolated from the aromatic plant Persicaria minor. Here, we report the expression, purification and characterization of recombinant P. minor sesquiterpene synthase protein (PmSTS). Insights into the catalytic active site were further provided by structural analysis guided by multiple sequence alignment.
METHODS: The enzyme was purified in two steps using affinity and size exclusion chromatography. Enzyme assays were performed using the malachite green assay and enzymatic product was identified using gas chromatography-mass spectrometry (GC-MS) analysis. Sequence analysis of PmSTS was performed using multiple sequence alignment (MSA) against plant sesquiterpene synthase sequences. The homology model of PmSTS was generated using I-TASSER server.
RESULTS: Our findings suggest that the recombinant PmSTS is mainly expressed as inclusion bodies and soluble aggregate in the E. coli protein expression system. However, the addition of 15% (v/v) glycerol to the protein purification buffer and the removal of N-terminal 24 amino acids of PmSTS helped to produce homogenous recombinant protein. Enzyme assay showed that recombinant PmSTS is active and specific to the C15 substrate FPP. The optimal temperature and pH for the recombinant PmSTS are 30 °C and pH 8.0, respectively. The GC-MS analysis further showed that PmSTS produces β-sesquiphellandrene as a major product and β-farnesene as a minor product. MSA analysis revealed that PmSTS adopts a modified conserved metal binding motif (NSE/DTE motif). Structural analysis suggests that PmSTS may binds to its substrate similarly to other plant sesquiterpene synthases.
DISCUSSION: The study has revealed that homogenous PmSTS protein can be obtained with the addition of glycerol in the protein buffer. The N-terminal truncation dramatically improved the homogeneity of PmSTS during protein purification, suggesting that the disordered N-terminal region may have caused the formation of soluble aggregate. We further show that the removal of the N-terminus disordered region of PmSTS does not affect the product specificity. The optimal temperature, optimal pH, Km and kcat values of PmSTS suggests that PmSTS shares similar enzyme characteristics with other plant sesquiterpene synthases. The discovery of an altered conserved metal binding motif in PmSTS through MSA analysis shows that the NSE/DTE motif commonly found in terpene synthases is able to accommodate certain level of plasticity to accept variant amino acids. Finally, the homology structure of PmSTS that allows good fitting of substrate analog into the catalytic active site suggests that PmSTS may adopt a sesquiterpene biosynthesis mechanism similar to other plant sesquiterpene synthases.

Matched MeSH terms: Polyisoprenyl Phosphates
Fulltext Confocal laser scanning microscopy study of dentinal tubules in dental caries stained with alizarin red

Marzuki, A.F., Masudi, S.M.

Archives of Orofacial Sciences, 2008;3(1):2-6.
MyJurnal

Dentin morphology and the lesion found in dental caries have been studied for many years. It was first observed under optical microscopy, and later using electron microscopy. Confocal laser scanning microscopy (CLSM) applied with several fluorescent dyes such as alizarin red to see normal dentinal tubules. However, as far as authors aware, the CLSM studies of dentinal tubules in human caries using alizarin red is rare. The aim of this study is to examine histopathological and morphological changes in dentinal tubules of dentin caries stained with alizarin red using CLSM. Fifteen extracted carious teeth (premolar or molar) was collected and fixed in neutral formalin solution buffered with phosphate buffer, rinsed and stored in calcium free phosphate buffer saline (PBS) at 4°C. The specimens were dehydrated and embedded in resin. Longitudinal or cross sections were cut and polished and then stained with alizarin red S (100 μg/ml) in 0.5 M HCl solution for 24-48 hour at 37°C. After dehydration specimens were mounted on glass slide and examined under CLSM using epi-flourescent mode or transmission light mode with wave length of 512 nm. The images of dentinal tubules were taken serially and optimum images of three-dimensional structures were reconstructed using software of CLSM. Histopathological changes of dentinal tubules in human caries showed area of demineralized dentin, translucent zone, and normal area. The dentinal tubules were thin and had numerous branches. In conclusion, confocal microscopy revealed Study shows that confocal microscopy revealed histopathological changes in dentinal tubules affected by carious lesions.

Matched MeSH terms: Phosphates
Fulltext Pattern of toothpaste usage in children under six years old

S. Nagarajan M.P. Sockalingam, Suhairah Jani, Noridawati Mohd Nor

Malaysian Dental Journal, 2010;31(1):14-19.
MyJurnal

Objectives: To assess pattern of toothpaste usage among young children under 6 years old.

Materials and methods: This was a cross-sectional descriptive study carried out at the Faculty of Dentistry, Universiti Kebangsaan Malaysia. Parents of children below 6 years old were involved. 200 questionnaires were distributed and 136 (68%) were returned for analysis. The questionnaire covered the following parameters: type, frequency, and quantity of toothpaste usage among children, level of parental knowledge of fluoride concentration in toothpaste and selection criteria of suitable toothpaste for their children.

Results: Majority of the respondents (83.1%) said they used children’s toothpaste to brush their child’s teeth and 62.5 % of them knew that the toothpaste used had fluoride in it. Slightly more than half of the respondents (53.7%) said they started brushing their child’s teeth one year after eruption of the first tooth. Almost an equal proportion of the respondents reported using toothpaste twice daily (50.7%) and only 44.1% of them supervised their children’s brushing. Respondents generally used more than a pea-sized toothpaste quantity (53.6%). Taste, fluoride concentration and brand of the toothpaste appeared to be the main criteria that influenced the selection of the toothpaste (55.9%). Income and educational levels of the respondents did not influence the type of toothpaste used.

Conclusion: These findings indicated that although parents were brushing their childrens’ teeth with children toothpaste, they were still unaware of the proper usage and importance of fluoridated toothpaste.

Matched MeSH terms: Phosphates
Fulltext Monitoring of water quality and microalgae species composition of Penaeus monodon ponds in Pulau Pinang, Malaysia

Asma Liyana Shaari, Misni Surif, Faazaz Abd. Latiff, Wan Maznah Wan Omar, Mohd Noor Ahmad

Trop Life Sci Res, 2011;22(1):-.
MyJurnal

Many reports have revealed that the abundance of microalgae in shrimp ponds vary with changes in environmental factors such as light, temperature, pH, salinity and nutrient level throughout a shrimp culture period. In this study, shrimp cultivation period was divided into three stages (initial = week 0–5, mid = week 6–10 and final = week 11–15). Physical and chemical parameters throughout the cultivation period were studied and species composition of microalgae was monitored. Physical parameters were found to
fluctuate widely with light intensity ranging between 182.23–1278 µmol photon m–2s–1, temperature between 29.56ºC –31.59ºC, dissolved oxygen (DO) between 4.56–8.21 mg/l, pH between 7.65–8.49 and salinity between 20‰–30‰. Ammonium (NH4+-N), nitrite (NO2– -N), nitrate (NO3– -N), and orthophosphate (PO43– -P) concentrations in the pond at all cultivation stages ranged from 0.017 to 0.38 mg/l, 0.24 to 2.12 mg/l, 0.06 to 0.98 mg/l and 0.16 to 1.93 mg/l respectively. Statistical test (ANOVA) showed that there were no significant difference (p

Matched MeSH terms: Phosphates
Fulltext Oncogenic osteomalacia, you say? better start looking then - a case report

Vijay, A.P., Tan, A.T.B., Suhaida, A.M., Chan, S.P.

JUMMEC, 2010;13(1):63-68.
MyJurnal

Tumour-induced or oncogenic osteomalacia (OOM) is a rare paraneoplastic syndrome characterized by bone pain and muscle weakness. A biochemical profile consisting of normocalcaemia, hypophosphataemia, phosphaturia, increased serum alkaline phosphatase and inappropriately low serum levels of 1, 25-dihydroxyvitamin-D is diagnostic. OOM is usually caused by an osseous or soft-tissue tumour of mesenchymal origin that secretes phosphaturic substances leading to increased urinary phosphate wasting. These tumours are small and slow growing. The diagnosis continues to be easily missed and when eventually made, localization of the tumour can be difficult. We describe the case of a young man who presented with severe generalized pain associated with muscle weakness. He was extensively investigated and eventually diagnosed to have OOM 3 years after initial presentation. Specialized investigations were necessary to localize the offending tumour.

Matched MeSH terms: Phosphates
Fulltext Phenotypic MicroArray (PM) profiles (carbon sources and sensitivity to osmolytes and pH) of Campylobacter jejuni ATCC 33560 in response to temperature

Tang, J.Y.H., Carlson, J., Mohamad Ghazali, F., Saleha, A.A., Nishibuchi, M., Nakaguchi, Y., et al.

International Food Research Journal, 2010;17(4):837-844.
MyJurnal

The present study aimed to provide an insight of C. jejuni ATCC 33560 phenotype profiles (carbon sources and sensitivity to osmolytes and pH) using Phenotypic MicroArray (PM) system in response to optimal and suboptimal temperature. C. jejuni ATCC 33560 showed utilization carbon sources from amino acids and carboxylates but not from sugars. C. jejuni ATCC 33560 is sensitive to NaCl at 2% and above but showed survival in a wide range of food preservatives (sodium lactate, sodium phosphate, sodium benzoate, ammonium sulphate and sodium nitrate). When incubated at suboptimal temperature, no phenotype loss was observed in carbon source plates. Phenotype loss of C. jejuni ATCC 33560 was observed in sodium chloride (1%), sodium sulphate (2-3%), sodium formate (1%), sodium lactate (7-12%), sodium phosphate pH7 (100mM and 200mM), ammonium sulphate pH8 (50mM), sodium nitrate (60mM, 80mM and 100mM), sodium nitrite (10mM), and growth in pH5. The phenotypic profile from present study will provide a better insight related to survival of C. jejuni ATCC 33560.

Matched MeSH terms: Phosphates
Fulltext Occurrence of Norovirus GI in green and red onion

Noor Hidayah, M.S., Tuan Zainazor, C., Pui, C.F., Noorlis, A., Noor Eliza, M.R., Naziehah, M.D., et al.

International Food Research Journal, 2011;18(2):677-681.
MyJurnal

Several Norovirus cases due to consumption of green onions have been reported during recent years but reports on red onions are not found. Onions are one of the major tastes in Malaysian food which are sometimes consuming raw especially the green onion. Viral contamination in onions can occur due to planting condition and not properly prepared food. This situation can pose the human health risk. A method was developed to detect the Norovirus that might present on different type of onions. In this study, 60 samples were collected from local market. Elution by Tryptose Phosphate Glycine broth and concentration steps using negatively charge filter were applied to enhance the detection of virus in food due to low copies of virus on food surface. The viral RNA was extracted using Qiagen Rneasy Mini kit before further detection using One-step RT-PCR. The total incidence of Norovirus in green onion and red onion was 13.33% (4/30) and 3.33 % (1/30) respectively. This is the first report of the detection of Norovirus in red and green onions in Malaysia. Based on the results, it is concluded that this method is reliable to detect Norovirus on onions and vegetables surface and hence can be applied in the laboratories for routine or food borne outbreak investigation.

Matched MeSH terms: Phosphates
Fulltext Synthesis and characterization of β-tricalcium phosphate ceramic via sol-gel method

Mohd Al Amin Muhamad Nor, Maryam Mohd Ridzuan, Zainal Arifin Ahmad

Journal of Nuclear and Related Technologies, 2009;2009(1):199-205.
MyJurnal

Ceramic materials play key role in several biomedical applications. One of them is bone graft which is use in treating bone defect which caused by injury or osteoporosis. Calcium phosphates based ceramic are preferred as bone grafts in hard tissue engineering because of their chemical compositions are similar to the composition of human bone, superior bioresorbable and bioactivity. In this study, β-tricalcium phosphate (β-TCP) ceramic was synthesized by using sol-gel method. Phosphorous pentoxide (P2O5) and calcium nitrate tetrahydrate (Ca(NO3)2.4H2O) were used as calcium and phosphate precursors. The effects of calcination temperature on the synthesis powder were studied using the XRD, SEM-EDS and FTIR techniques. It was found that calcination temperature greatly influence the purity of the synthesized powders. The β-TCP was the dominant phase with the formation of α-TCP at calcination temperature from 600 to 800°C. Pure β-TCP was obtained at calcination of 900°C. As the temperature increased to 1000°C, the β-TCP was decomposed to for calcium phosphate oxide (CPO). The sol-gel method has some advantages over other methods, mainly its simplicity and ability to produce pure β-TCP at lower calcination temperature.

Matched MeSH terms: Calcium Phosphates
Fulltext Removal of copper from aqueous solution by adsorption using magnesium aluminium hydrogenphosphate layered double hydroxides

Zaini Hamzah, Mohd Najif Ab Rahman, Siti Mariam Sumari, Yamin Yasin, Ahmad Saat

Journal of Nuclear and Related Technologies, 2011;2011(2):60-67.
MyJurnal

Layered double hydroxide (LDH) with Mg/Al molar ratio of 4/1 (MAN-4) was synthesized by co-precipitation and followed by hydrothermal method. The compound was allowed to undergo ion exchange with K2HPO4 for 48 hours to produce MgAlHPO4 (MAHP-4). The solid produced was characterized using X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR). Adsorption of copper solution by MAHP-4 was carried out using batch experiment by mixing the copper solution and the sorbent MAHP-4. The effects of
various parameters such as contact time, pH, adsorbent dosage and initial concentration were investigated. The optimum pH for copper removal was found to be 4 and the optimum time of copper removal was found at 4 hours. The isotherm data was analysed using model isotherm Langmuir with the correlation coefficient of 0.999 was recorded. The maximum adsorption capacity, Qo (mg/g) of 142.8 mg/g was also recorded from the Langmuir isotherm. The remaining copper solution was determined by using EDXRF (Energy Dispersive XRay Fluorescence spectrometry) model MiniPal 4 (PAN analytical). The results in this study indicate that MAHP-4 has potential as an effective adsorbent for removing copper from aqueous solution.

Matched MeSH terms: Phosphates
Fulltext Physical, chemical & mineralogical properties of fly ash

Khairul Nizar Ismail, Kamarudin Hussin, Mohd Sobri Idris

Journal of Nuclear and Related Technologies, 2007;2005(1):47-51.
MyJurnal

Fly ash is the finely divided mineral residue resulting from the combustion of coal in electric generating plants. Fly ash consists of inorganic, incombustible matter present in the coal that has been fused during combustion into a glassy, amorphous structure. Fly ash particles are generally spherical in shape and range in size from 2 μm to 10 μm. They consist mostly of silicon dioxide (SiO2), aluminium oxide (Al2O3) and iron oxide (Fe2O3). Fly ash like soil contains trace concentrations of the following heavy metals: nickel, vanadium, cadmium, barium, chromium, copper, molybdenum, zinc and lead. The chemical compositions of the sample have been examined and the fly ash are of ASTM C618 Class F.

Matched MeSH terms: Phosphates
Fulltext DNA extraction from ghee and beef species identification using polymerase chain reaction (PCR) assay

Nooratiny, I., Sahilah, A.M., Alif Alfie, A.R., Mohd. Farouk, M.Y.

International Food Research Journal, 2013;20(5):2959-2961.
MyJurnal

A technique to isolate DNA from ghee was developed for the authentication of beef fat product. The method was based on pre-mixed ghee with phosphate buffer solution (PBS) prior to DNA extraction using Epicentre extraction method. The recovery of beef DNA was then analysed by polymerase chain reaction (PCR) using beef species-specific oligonucleotide primers which targeted the mitochondria DNA (mtDNA) of cytochrome b (cyt b) gene. The amplicon was 274 bp in size. The developed ghee extraction method offers a high yield of DNA providing 100 ng per μl and useful for validating beef fat product.

Matched MeSH terms: Phosphates
Fulltext Fluoride Level In Dentifrices

Abdul Kadir, R., Latifah Abdol Latif

Ann Dent, 1998;5(1):-.
MyJurnal

To date, fluorides has remained to be the best means of controlling dental caries. Fluoride is given either systematically via fluoridated water or topically through other supplements including toothpastes. In recent years increasing prevalence of enamel defects or fluorosis is observed in both populations receiving or not receiving water fluoridation. It is suspected that excessive ingestion of a "standard" 1000 to 1500 ppm fluoride from toothpastes might be a contributing factor to the presence of such defects. In Malaysia, reports of enamel defects occurring amongst 12 to 16 year-old schoolchildren ranged between 67 to 88 percent. Where water fluoridation is available, the amount of fluorides received from the home is between 0.3 to 0.5 ppm F. However, almost all toothpastes sold locally contains fluoride, the content of which is unknown to the consumers. This study reports on the analysis of fluoride levels carried out on 20 toothpaste samples sold locally. Results showed that fluoride levels in all 20 samples ranged between 20 to 1970 ppm F. Only two of the 20 samples analyzed, however, indicated having a level anywhere near the "standard" level. In addition, only two type~ of children's toothpaste with a fluoride concentration of 20 and 450 ppm F were commonly available as compared to adult toothpastes in all the samples studied.

Matched MeSH terms: Phosphates
Fulltext Toothpastes Available In The Malaysian Market

Saub, R.

Ann Dent, 1998;5(1):-.
MyJurnal

This study was undertaken to investigate the number and types (fluoride or non-fluoride) of toothpaste products available in the Malaysian market based on the label. Thirty-five brands of toothpaste were identified, of which ten (29%) were specifically recommended for children. Two of the children's toothpaste recommended that children below seven years old use a pea size amount of toothpaste. One (3%) was recommended for both children and adult. The remaining 24 (69%) did not state if they were recommended for either children or adults. To improve the flavour of the toothpastes, a variety of flavours had been added especially in children's toothpaste. Almost half of the toothpastes were for prevention of tooth decay and gum disease. Other indications were for tooth sensitivity, tooth whitening and stain removal. Twentyseven (77%) of the toothpastes were imported, while eight (23%) were made in Malaysia. Twenty-six (74%) of the toothpaste contained fluoride and the most common type of fluoride used was sodium monofluorophosphate (NaMFP). The fluoride concentration was not labeled in more than half (63%) of the fluoridated toothpaste. Of those that were fluoridated, different units of measurement were used. As there is no uniformity in the labelling of these products, it is recommended that the responsible authorities should take more action in enforcing proper labelling of the fluoride concentration in the toothpaste using standardized units.

Matched MeSH terms: Phosphates
Fulltext Characterization of Immunoglobulin E-Binding Proteins (IgE) of Scomberomorus commerson Lacepede

Rosmilah Misnan, Shahnaz Murad, Masita Arip, Noormalin Abdullah, Jamaludin Mohamed

Jurnal Sains Kesihatan Malaysia, 2005;3(2):79-87.
MyJurnal

The objective of this study was to determine the Immunoglobulin E-binding proteins (IgE) and major allergens of Scomberomorus commerson Lacepede (Narrow-barred Spanish mackerel). Allergen extracts were obtained from uncooked and cooked fish by homogenization in phosphate-buffered saline followed by continuous extraction at 4oC or on ice. Protein profiles and IgEbinding patterns were then detected by means of sodium dodecyl polyacrylamide gel electrophoresis (SDS PAGE) and immunoblotting using sera from patients sensitized to the fish. SDS-PAGE of the uncooked fish extracts revealed 26 protein bands in the range of about 11 to >175 kD, while the cooked extracts produced fewer protein bands. Immunoblotting demonstrated 17 IgE-binding bands, ranging in molecular weight from 11 to 151 kD. Two components with molecular weight of about ~50 and 42 kD showed the highest frequency of IgE-binding (62.2 and 51.4% respectively) and were identified as the major allergens of this fish allergy. Other IgE-binding proteins including a protein at ~12 kD which was equivalent in size to parvalbumin were identified as the minor allergens.

Matched MeSH terms: Phosphates
Fulltext Effect of uv-ozone treatment on physicochemical properties of mesoporous hollow carbon nanoparticles

Muhammad Nur Amir Azman, Yusilawati Ahmad Nor, Nur Husna Samsudin, Ma’an Fahmi Rashid Alkhatib, Yeow, Tshai Kim

Biological and Natural Resources Engineering Journal, 2020;3(2):35-45.
MyJurnal

Carbon nanoparticles have been widely used in various applications. However, they are commonly known to have low dispersibility and chemical inertness which limit their practical ability in medical or biological area. Some studies have been performed to modify carbon nanoparticles such as carbon nanotubes using ultraviolet (UV)-Ozone system. However, little is known on the effects of such system towards other types of carbon nanoparticles such as mesoporous hollow carbon nanoparticles (MHCNs). Thus, in this study, improvement of MHCNs physiochemical properties have been studied using UV-Ozone treatment for the first time. The treatment was conducted in water as dispersant agent at ozone flowrate of 1.0 L/min and exposure time of 45 min. SEM images observed that MHCNs morphology and surface structure remain intact after the treatment. Observations on the dispersibility of MHCNs in phosphate buffered saline (PBS) solution shows that the dispersibility was improved compared to the untreated ones. This was supported by the low Z-average and PDI values of treated MHCNs obtained at ~400 nm and 0.2, respectively when compared to the untreated MHCNs which was obtained at 970 nm and 0.417, respectively. Thermogravimetric analysis (TGA) showed an increased in weight loss of treated MHCNs at the lower temperature compared to untreated MHCNs. Results from Fourier Transform Infrared (FTIR) showed an increase number of new functional groups that includes carboxylic acid group presence at the surface of treated MHCNs which contributes to the improvement of their dispersibility, thermal properties and chemical functionality. These findings opened a new possibility of using UV-Ozone treatment to improve physicochemical properties of MHCNs for medical area such as in drug delivery application in addition to their excellent storage and carrier system.

Matched MeSH terms: Phosphates
Fulltext Evaluation of interface adhesion between silicone soft liners and denture base after immersion with denture cleansers by scanning electron microscope

Aiemeeza Rajali, Siti Fauzza Ahmad

Malaysian Journal of Medicine and Health Sciences, 2020;16(3):148-154.
MyJurnal

Introduction: The compatibility of denture cleanser is crucial in the prevention of failure of adhesion between silicone soft liner and acrylic denture base, thus ensuring the durability of the prosthesis. This scanning electron microscope (SEM) study was to determine the mode of failure and measured the gap formation between silicone soft liners and Polymethylmethacrylate (PMMA) denture base after immersion in denture cleansers. Methods: A total of 135 specimens of PMMA denture base lined with three different silicone soft liners (GC Reline Soft, Mollosil and Tokuyama Sofreliner Tough) were immersed into denture cleansers (Polident® and Stearadent) daily and stored in distilled water at 37±1°C. Specimens were examined and sectioned at 2.5mm and 5.0mm from the margin after 1 day, 30 days and 90 days before analyzed. Results: No significant difference detected in the mode of failure and gap formation after one-day immersion. Adhesive failure was the commonest failure at the margin after 30 days (71.11%) and after 90 days (95.56%). However, 33.33% of specimens showed mixed failure at 5.0mm sectioned after 90 days. A significant difference of gap formation was demonstrated from Mollosil in Steradent at the margin and at 2.5 mm sectioned after 30 days and after 90 days (p

Matched MeSH terms: Phosphates
Fulltext Antibacterial efficacy and drug-release behavior study of β-tricalcium phosphate micro-granules against staphylococcus aureus and Escherichia coli

Nor Hazliana Harun, Rabiatul Basria S.M.N. Mydin, Khairul Anuar Shariff, Nur Adila Rosdi, Davamunisvari Rames

Malaysian Journal of Medicine and Health Sciences, 2020;16(3):202-206.
MyJurnal

Introduction: This study aims to investigate different residue sizes of β-tricalcium phosphate (β-TCP) micro-granules as carriers to assess antibacterial activity and drug-control release behavior of ampicillin (AMP-) and antimycotic (AMC-). Incorporation of antibiotic into the β-TCP micro-granules and it sustain release behavior could be used as alternative solution to reduce the risk of osteomyelitis and bone infections risks. Methods: Three different residue sizes (less than 300 µm, 300 µm and 600 µm) were prepared and coated with antibiotics solution (20 µg/µl of ampi- cillin and 100X antimycotic solution) by using two methods; dip and stream coating. After 72 h, 1.5 mL of distilled water was added to the treated (β-TCP) micro-granules at two different pH value (5.0 and 7.4). The extracted solution was further analyzed by Kirby Bauer disc diffusion test and spectrophotometer assay. Results: The solution con- taining AMC-(β-TCP) micro-granules with the size of 300 µm residue produced the largest inhibition zones against Escherichia coli (E. coli). All residue sizes coated with AMP- showed no antibacterial activity against both strains; Staphylococcus aureus (S. aureus) and E.coli. Additionally, the release behavior of AMC-(β-TCP) micro-granules was found not depending on the pH, but on the size of residue. Complete drug release was rapidly observed within 48
h. Conclusion: Based on this findings, it showed AMC-(β-TCP) micro-granules had an antibacterial activity against Gram-negative strain. Specifically, it can reduced the growth rate of E. coli and the rapid release behavior of AMC- (β-TCP) micro-granules help in minimizing the risk-infections in early stage of implantation.

Matched MeSH terms: Calcium Phosphates
Fulltext Optical pH Sensor Based on Immobilization Anthocyanin from Dioscorea alata L. onto Polyelectrolyte Complex Pectin-Chitosan Membrane for a Determination Method of Salivary pH

Safitri E, Humaira H, Murniana M, Nazaruddin N, Iqhrammullah M, Md Sani ND, et al.

Polymers (Basel), 2021 Apr 14;13(8).
PMID: 33919956 DOI: 10.3390/polym13081276

A simple optical pH sensor based on immobilization, Dioscorea alata L. anthocyanin methanol extract, onto a pectin-chitosan polyelectrolyte complex (pectin-chitosan PEC), has been successfully fabricated. The optical pH sensor was manufactured as a membrane made of pectin-chitosan PEC and the extracted anthocyanin. This sensor has the highest sensitivity of anthocyanin content at 0.025 mg/L in phosphate buffer and 0.0375 mg/L in citrate buffer. It also has good reproducibility with a relative standard deviation (%RSD) of 7.7%, and gives a stable response at time values greater than 5 min from exposure in a buffer solution, and the sensor can be utilized within five days from its synthesis. This optical pH sensor has been employed to determine saliva pH of people of different ages and showed no significant difference when compared to a potentiometric method.

Matched MeSH terms: Phosphates

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