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  1. Prevalence of Bacillus cereus in selected foods and detection of enterotoxin using TECRA-VIA and BCET-RPLA
    Rusul G, Yaacob NH
    Int J Food Microbiol, 1995 Apr;25(2):131-9.
    PMID: 7547144
    Enterotoxigenic Bacillus cereus was detected in cooked foods (17), rice noodles (3), wet wheat noodles (2), dry wheat noodles (10), spices (8), grains (4), legumes (11) and legume products (3). One hundred ninety-four (42.3%), 70 (15.3%) and 23 (5.2%) of the 459 presumptive B. cereus colonies isolated from PEMBA agar were identified as B. cereus, Bacillus thuringiensis and B. mycoides, respectively. B. cereus isolates were examined for growth temperature, pH profile and enterotoxin production using both TECRA-VIA and BCET-RPLA kits. One hundred seventy-eight (91.8%) and 164 (84%) of the strains were enterotoxigenic as determined using TECRA-VIA and BCET-RPLA, respectively. Eighty-two (50%) of the enterotoxigenic strains were capable of growing at 5 degrees C, and 142 (86.6%) grew at 7 degrees C within 7 days of incubation. The enterotoxigenic strains did not grow at pH 4.0 but 69 (42.0%) of the strains were able to grow at pH 4.5 within 7 days at 37 degrees C. The isolates were resistant to ampicillin (98.8%), cloxallin (100%) and tetracycline (61.0%), and susceptible to chloroamphenicol (87%), erythromycin (77.4%), gentamycin (100%) and streptomycin (98.7%).
  2. Incorporating waste into an experimental school prototype: lessons regarding materials reclamation opportunities
    Yeap KS, Mohd Yaacob N, Rao SP, Hashim NR
    Waste Manag Res, 2012 Dec;30(12):1251-60.
    PMID: 23103414 DOI: 10.1177/0734242X12465459
    This article presents lessons learned from a design project that explored the possibility of incorporating waste into the design of a school prototype. The authors worked with professional architects, a waste artist, environmental scientists and local waste operators to uncover new uses and applications for discarded items. As a result, bottles, aluminium cans, reclaimed doors, crushed concrete and second-hand bricks, etc. were identified, explored and integrated into the architectural design. This article serves as a catalyst that advocates the use of reclaimed materials in the field of design and planning. In particular, it highlights the challenges and issues that need to be addressed in carrying out design work with waste. Designers and practitioners interested in minimizing waste generation by proposing the use of reclaimed materials will find this article useful.
  3. In vitro biocompatibility of chitosan porous skin regenerating templates (PSRTs) using primary human skin keratinocytes
    Lim CK, Yaacob NS, Ismail Z, Halim AS
    Toxicol In Vitro, 2010 Apr;24(3):721-7.
    PMID: 20079826 DOI: 10.1016/j.tiv.2010.01.006
    Biopolymer chitosan (beta-1,4-d-glucosamine) comprises the copolymer mixture of N-acetylglucosamine and glucosamine. The natural biocompatibility and biodegradability of chitosan have recently highlighted its potential use for applications in wound management. Chemical and physical modifications of chitosan influence its biocompatibility and biodegradability, but it is unknown as to what degree. Hence, the biocompatibility of the chitosan porous skin regenerating templates (PSRT 82, 87 and 108) was determined using an in vitro toxicology model at the cellular and molecular level on primary normal human epidermal keratinocytes (pNHEK). Cytocompatibility was accessed by using a 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl tetrazolium bromide (MTT) assay from 24 to 72h. To assess the genotoxicity of the PSRTs, DNA damage to the pNHEK was evaluated by using the Comet assay following direct contact with the various PSRTs. Furthermore, the skin pro-inflammatory cytokines TNF-alpha and IL-8 were examined to evaluate the tendency of the PSRTs to provoke inflammatory responses. All PSRTs were found to be cytocompatible, but only PSRT 108 was capable of stimulating cell proliferation. While all of the PSRTs showed some DNA damage, PSRT 108 showed the least DNA damage followed by PSRT 87 and 82. PSRT 87 and 82 induced a higher secretion of TNF-alpha and IL-8 in the pNHEK cultures than did PSRT 108. Hence, based on our experiments, PSRT 108 is the most biocompatible wound dressing of the three tested.
  4. Fulltext Effects of glucose, ethanol and acetic acid on regulation of ADH2 gene from Lachancea fermentati
    Yaacob N, Mohamad Ali MS, Salleh AB, Abdul Rahman NA
    PeerJ, 2016;4:e1751.
    PMID: 26989608 DOI: 10.7717/peerj.1751
    Background. Not all yeast alcohol dehydrogenase 2 (ADH2) are repressed by glucose, as reported in Saccharomyces cerevisiae. Pichia stipitis ADH2 is regulated by oxygen instead of glucose, whereas Kluyveromyces marxianus ADH2 is regulated by neither glucose nor ethanol. For this reason, ADH2 regulation of yeasts may be species dependent, leading to a different type of expression and fermentation efficiency. Lachancea fermentati is a highly efficient ethanol producer, fast-growing cells and adapted to fermentation-related stresses such as ethanol and organic acid, but the metabolic information regarding the regulation of glucose and ethanol production is still lacking. Methods. Our investigation started with the stimulation of ADH2 activity from S. cerevisiae and L. fermentati by glucose and ethanol induction in a glucose-repressed medium. The study also embarked on the retrospective analysis of ADH2 genomic and protein level through direct sequencing and sites identification. Based on the sequence generated, we demonstrated ADH2 gene expression highlighting the conserved NAD(P)-binding domain in the context of glucose fermentation and ethanol production. Results. An increase of ADH2 activity was observed in starved L. fermentati (LfeADH2) and S. cerevisiae (SceADH2) in response to 2% (w/v) glucose induction. These suggest that in the presence of glucose, ADH2 activity was activated instead of being repressed. An induction of 0.5% (v/v) ethanol also increased LfeADH2 activity, promoting ethanol resistance, whereas accumulating acetic acid at a later stage of fermentation stimulated ADH2 activity and enhanced glucose consumption rates. The lack in upper stream activating sequence (UAS) and TATA elements hindered the possibility of Adr1 binding to LfeADH2. Transcription factors such as SP1 and RAP1 observed in LfeADH2 sequence have been implicated in the regulation of many genes including ADH2. In glucose fermentation, L. fermentati exhibited a bell-shaped ADH2 expression, showing the highest expression when glucose was depleted and ethanol-acetic acid was increased. Meanwhile, S. cerevisiae showed a constitutive ADH2 expression throughout the fermentation process. Discussion. ADH2 expression in L. fermentati may be subjected to changes in the presence of non-fermentative carbon source. The nucleotide sequence showed that ADH2 transcription could be influenced by other transcription genes of glycolysis oriented due to the lack of specific activation sites for Adr1. Our study suggests that if Adr1 is not capable of promoting LfeADH2 activation, the transcription can be controlled by Rap1 and Sp1 due to their inherent roles. Therefore in future, it is interesting to observe ADH2 gene being highly regulated by these potential transcription factors and functioned as a promoter for yeast under high volume of ethanol and organic acids.
  5. Alteration of plasma alanine, glutamate, and glycine Level: A potentiate manic episode of bipolar disorder
    Wan Nasru WN, Ab Razak A, Yaacob NM, Wan Azman WN
    Malays J Pathol, 2021 Apr;43(1):25-32.
    PMID: 33903302
    INTRODUCTION: The amino acids that function as co-agonists at the N-methyl-D-aspartate (NMDA) receptor have been investigated in bipolar disorder (BD). However, studies comparing amino acid levels in the plasma of BD patients with healthy controls have yielded inconsistent results. We, therefore, conducted a study in Hospital Universiti Sains Malaysia to determine the plasma levels of glutamate, glycine, and alanine in BD patients and compared them with the healthy controls.

    MATERIALS AND METHODS: An overnight fast of 10-hour plasma levels of glutamate, glycine, alanine, and tryptophan were measured in 83 bipolar patients, and were compared to a group of 82 healthy controls.

    RESULTS: The mean (SD) age of bipolar patients was 40.9 (12.1), while the mean (SD) age for control groups was 35.6 (7.7) years. The median (25th, 75th percentile) of glutamate and alanine levels in bipolar patients was 111.0 (65.0,176.0) and 530.0 (446.0,629.0), respectively, while the mean (SD) of glycine level in bipolar patients was 304.0 (98.1). Significant higher glutamate, glycine, and alanine levels were found in bipolar disorder patients in the manic episode as compared to the healthy controls.

    CONCLUSION: Although the exact relationship between peripheral NMDA receptor co-agonist levels in the pathogenesis of BD is not well understood, these findings should be explored and may enlighten some new paths for BD therapy which could reward the patients also clinicians.

  6. Comparing the clinical effects of balanced electrolyte solutions versus normal saline in managing diabetic ketoacidosis: A systematic review and meta-analyses
    Tamzil R, Yaacob N, Noor NM, Baharuddin KA
    Turk J Emerg Med, 2023;23(3):131-138.
    PMID: 37529790 DOI: 10.4103/tjem.tjem_355_22
    The first-line treatment of diabetes ketoacidosis (DKA) involves fluid resuscitation with normal saline infusion to correct hypovolemia. Hyperchloremic metabolic acidosis from aggressive normal saline administration was associated with worse clinical outcomes in managing DKA. Other choices for normal saline include balanced electrolyte solutions (BESs). This study aimed to compare the clinical effects between BESs and normal saline in managing DKA. This study was a systematic review of probing articles published from inception to October 2021 in Cochrane Central Register of Controlled Trials, Medical Literature Analysis and Retrieval System Online, Google Scholar, and Scopus. Eight randomized controlled trials with a total of 595 individuals were included. The data were analyzed at 95% confidence level using random-effects models. For the primary outcomes, there was no difference in the duration of DKA resolution. (Mean difference [MD] -4.73, 95% confidence interval [CI] -2.72-4.92; I2 = 92%; P = 0.180). However, there was a significantly lower postresuscitation chloride concentration in the BES (MD 2.96 95% CI - 4.86 to - 1.06; I2 = 59%; P = 0.002). For the secondary outcomes, there was a significant reduction in duration for normalization of bicarbonate in the BES group (MD 3.11 95% CI - 3.98-2.23; I2 = 5%; P = 0.0004). There were no significant differences between groups in duration for recovery of pH, intensive unit admission, and adverse events (mortality and acute renal failure). Resuscitation with BES was associated with decreased chloride and increased bicarbonate values in DKA patients. It suggests that BES prevents DKA patients from hyperchloremic metabolic acidosis.
  7. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) method development for screening of potential tamoxifen-drug/herb interaction via in vitro cytochrome P450 inhibition assay
    Yong YF, Tan SC, Liew MWO, Yaacob NS
    J Chromatogr B Analyt Technol Biomed Life Sci, 2020 May 08;1148:122148.
    PMID: 32416571 DOI: 10.1016/j.jchromb.2020.122148
    Screening for potential drug-drug interaction (DDI) or herb-drug interaction (HDI) using in vitro cytochrome P450 inhibition (IVCI) assays requires robust analytical methods with high sensitivity and reproducibility. Utilization of liquid chromatography-mass spectrometry (LC-MS) for analyte quantification is often hampered by the presence of non-volatile IVCI sample buffer constituents that often results in ion suppression. In this study, to enable screening of drug interactions involving tamoxifen (TAM) metabolism using IVCI-LC-MS/MS, a liquid-liquid extraction (LLE) method was developed and optimized for sample clean-up. Utilization of chloroform as extraction solvent and adjustment of sample pH to 11 was found to result in satisfactory recovery (>70%) and low ion suppression (<19%). A LC-MS/MS method was subsequently developed and validated for simultaneous quantification of major TAM metabolites, such as N-desmethyltamoxifen (NDT), endoxifen (EDF) and 4-hydroxytamoxifen (HTF) to enable IVCI sample analysis. Satisfactory separation of E-/Z-isomers of endoxifen with peak resolution (Rs) of 1.9 was achieved. Accuracy and precision of the method was verified within the linear range of 0-50 ng/mL for NDT, 0-25 ng/mL for HTF and 0-25 ng/mL for EDF (E/Z isomers). Inhibitory potency (IC50, Ki and mode of inhibition) of known CYP inhibitors and Strobilanthes crispus extract was then evaluated using the validated method. In summary, the results demonstrated applicability of the developed LLE and validated LC-MS/MS method for in vitro screening of DDI and HDI involving TAM metabolism.
  8. Transarterial angioembolization versus surgery after failed endoscopic therapy for non-variceal upper gastrointestinal bleeding
    Jailani RF, Kosai NR, Yaacob NY, Jarmin R, Sutton P, Harunarrashid H, et al.
    Clin Ter, 2014;165(6):294-8.
    PMID: 25524184 DOI: 10.7417/CT.2014.1771
    BACKGROUND AND OBJECTIVE: To compare the outcome of transarterial angioembolization (TAE) and surgery with endoscopically unmanageable non-variceal hemorrhage of the upper gastrointestinal tract.

    MATERIALS AND METHODS: A case note review of all patients treated for non-variceal upper gastrointestinal bleeding from January 2006 till January 2012 was performed.

    RESULTS: Fifty-four of 667 patients with non-variceal bleeding did not respond to endoscopic treatment. Nine of the 54 patients had incomplete data, leaving 45 patients in the study; 24 had angiography and another 21 had surgery. The two groups were broadly similar in terms of relevant clinical variables. Nineteen of 24 having angiography had embolisation. Re-bleeding recurred in 8 patients (33%) in the TAE group and 6 patients (28.6%) in the surgery group (p = 0.28). There was no statistically significant difference in post procedural complications (81% vs 62.5%, p = 0.17), 30-day mortality (33% vs 29.1%, p = 0.17 ) units of blood transfused (12.24 vs 8.92, p = 0.177) and mean hospital stay (30.7 vs 22.9 days, p = 0.281) observed in patients undergoing surgery as compared to TAE.

    CONCLUSIONS: TAE and surgery have similar outcomes in patients with endoscopically unmanageable non-variceal upper gastrointestinal haemorrhage.
  9. Chlorella vulgaris modulates hydrogen peroxide-induced DNA damage and telomere shortening of human fibroblasts derived from different aged individuals
    Makpol S, Yaacob N, Zainuddin A, Yusof YA, Ngah WZ
    Afr J Tradit Complement Altern Med, 2009 Jul 03;6(4):560-72.
    PMID: 20606778
    The objective of this study was to investigate the modulatory effect of Chlorella vulgaris on cultured fibroblast cells derived from young and old aged individuals focusing on DNA damage, telomere length and telomerase activity. Dose-response test of the algal extract on cells in both age groups revealed that optimum viability was observed at a concentration of 50 microg/ml. Results obtained showed that Chlorella vulgaris exhibited protective effects against H(2)O(2)-induced oxidative stress as shown by the reduction in damaged DNA caused by H(2)O(2) treatment (p<0.05) in Chlorella vulgaris pre- and post-treated groups (p<0.05). Pre-treatment of Chlorella vulgaris resulted in a significant decrease in DNA damage suggesting a bioprotective effect against free radical attacks. A decline in DNA damage was observed in post-treated cells which proves Chlorella vulgaris to present bioremediative properties. In cells induced with oxidative stress, telomere length decreased significantly coupled with a concomitant decline of telomerase activity (p<0.05). However, these reductions were prevented with prior and post treatment of Chlorella vulgaris. Therefore, we concluded that Chlorella vulgaris exhibited bioprotective effects especially in cells obtained from young donor but were more bioremediative for cells obtained from old donor as indicated by DNA damage, telomere shortening and reduction in telomerase activity.
  10. Diffuse hepatic haemangiomatosis: A case report and review of literature
    Rao R, Naidu J, Muhammad Nawawi KN, Wong ZQ, Ngiu CS, Mohammed F, et al.
    Med J Malaysia, 2018 12;73(6):436-438.
    PMID: 30647226
    Hepatic haemangioma is a solitary liver lesion and prevalent among the female patients. We report a case of diffuse hepatic haemangiomatosis in a 62-year-old man, who was referred for an incidental finding of multiple liver nodules. History and physical examinations were unremarkable. Computed tomography and magnetic resonance imaging of the liver were performed and showed multiple haemangiomatosis. In view of the rarity of this condition in men, a liver biopsy was done and confirmed haemangiomas. Available published literature on diffuse hepatic haemangiomatosis was reviewed.
  11. Toluene promotes lid 2 interfacial activation of cold active solvent tolerant lipase from Pseudomonas fluorescens strain AMS8
    Yaacob N, Mohamad Ali MS, Salleh AB, Rahman RNZRA, Leow ATC
    J Mol Graph Model, 2016 07;68:224-235.
    PMID: 27474867 DOI: 10.1016/j.jmgm.2016.07.003
    The utilization of cold active lipases in organic solvents proves an excellent approach for chiral synthesis and modification of fats and oil due to the inherent flexibility of lipases under low water conditions. In order to verify whether this lipase can function as a valuable synthetic catalyst, the mechanism concerning activation of the lid and interacting solvent residues in the presence of organic solvent must be well understood. A new alkaline cold-adapted lipase, AMS8, from Pseudomonas fluorescens was studied for its structural adaptation and flexibility prior to its exposure to non-polar, polar aprotic and protic solvents. Solvents such as ethanol, toluene, DMSO and 2-propanol showed to have good interactions with active sites. Asparagine (Asn) and tyrosine (Tyr) were key residues attracted to solvents because they could form hydrogen bonds. Unlike in other solvents, Phe-18, Tyr-236 and Tyr-318 were predicted to have aromatic-aromatic side-chain interactions with toluene. Non-polar solvent also was found to possess highest energy binding compared to polar solvents. Due to this circumstance, the interaction of toluene and AMS8 lipase was primarily based on hydrophobicity and molecular recognition. The molecular dynamic simulation showed that lid 2 (residues 148-167) was very flexible in toluene and Ca(2+). As a result, lid 2 moves away from the catalytic areas, leaving an opening for better substrate accessibility which promotes protein activation. Only a single lid (lid 2) showed the movement following interactions with toluene, although AMS8 lipase displayed double lids. The secondary conformation of AMS8 lipase that was affected by toluene observed a reduction of helical strands and increased coil structure. Overall, this work shows that cold active lipase, AMS8 exhibits distinguish interfacial activation and stability in the presence of polar and non-polar solvents.
  12. Fulltext Serum Procalcitonin (PCT) - Is there a Role as an Early Biomarker in Infected Diabetic Foot Ulcer (IDFU) Patients?
    Omar J, Ahmad NS, Che-Soh N, Wan-Azman WN, Yaacob NM, Abdul-Ghani NS, et al.
    Malays Orthop J, 2023 Jul;17(2):62-69.
    PMID: 37583519 DOI: 10.5704/MOJ.2307.010
    INTRODUCTION: Infected diabetic foot ulcers may lead to serious complications if not recognised in the early stage. Diagnosis of infection is particularly challenging at that stage; thus, a sensitive inflammatory biomarker may be helpful. We aimed to evaluate the role of procalcitonin (PCT) as an early biomarker for infected diabetic foot ulcers (IDFU).

    MATERIALS AND METHOD: This cross-sectional study was conducted at Klinik Rawatan Keluarga (KRK), Orthopedic clinic and wards in Hospital Universiti Sains Malaysia (USM) from May 2020 to December 2020. A total of 264 participants were recruited and divided into three groups: 50 diabetic patients with no ulcers (control), 107 patients with non-infected diabetic foot ulcers (NIDFU), and 107 patients with infected diabetic foot ulcers (IDFU). The level of PCT was taken for all patients. Total white count (TWC) and C-reactive protein (CRP) were taken only for IDFU patients. Diagnosis of infection was based on the Infectious Disease Society of America-International Working Group of Diabetic Foot (IDSA-IMWGDF), and the severity of infection was graded according to the Wagner Classification.

    RESULTS: The level of PCT was higher in IDFU than in NIDFU and diabetic patient, with a median (IQR) of 0.355 (0.63) ng/mL, 0.077 (0.15) ng/mL and 0.028 (0.02) ng/mL, respectively. PCT and CRP showed moderate positive correlations in IDFU patients (p<0.001). The sensitivity and specificity were 63.6% and 83.2%, respectively, at the best cut-off at 0.25 ng/mL.

    CONCLUSION: PCT is a valuable biomarker for the diagnosis of infection; however, it adds little value in the early diagnosis of IDFU in view of its low sensitivity.

  13. Fulltext Comparison between hCG and GnRH Agonist for Ovulation Trigger in GnRH Antagonist In-Vitro Fertilization Cycles in a Tertiary Hospital in Malaysia: An observational study
    Aziz NA, Ibrahim A, Ramli R, Yaacob N, Rahman SNA, Ismail EHE, et al.
    JBRA Assist Reprod, 2024 Feb 26;28(1):21-26.
    PMID: 38224580 DOI: 10.5935/1518-0557.20230066
    OBJECTIVE: hCG is commonly used as an ovulation trigger in IVF. Its usage is associated with OHSS. GnRH agonist is an alternative to hCG and is associated with reduced incidence of OHSS. This study compared the cycle outcomes of GnRH agonists with hCG as an ovulation trigger in IVF cycles.

    METHODS: The medical notes of 209 IVF cycles receiving GnRH agonist and hCG as ovulation trigger over 18 months were reviewed in this retrospective study. The number and quality of mature oocytes, the number and quality of embryos, pregnancy rates, and outcomes were compared using Independent T-test or One-way ANOVA for normal distribution. The Mann-Whitney test or Kruskal-Wallis test was used for not normally distributed. p<0.05 was considered statistically significant.

    RESULTS: The cycle outcomes of 107 GnRH agonist-trigger and 102 hCG-trigger were compared. The MII oocytes retrieved and 2PN count was significantly higher in the GnRH agonist trigger group (p<0.001). Clinical pregnancy rate and ongoing pregnancy were higher in the GnRH agonist trigger group but were not statistically significant. The GnRH agonist trigger group was associated with low OHSS than the hCG trigger group (n=2(1.9%) and n=12(11.8%) respectively, p=0.004).

    CONCLUSION: GnRH agonist trigger is an option as a final maturation trigger in high-responder women undergoing IVF or ICSI cycles.

  14. Cold-adapted organic solvent tolerant alkalophilic family I.3 lipase from an Antarctic Pseudomonas
    Ganasen M, Yaacob N, Rahman RN, Leow AT, Basri M, Salleh AB, et al.
    Int J Biol Macromol, 2016 Nov;92:1266-1276.
    PMID: 27506122 DOI: 10.1016/j.ijbiomac.2016.06.095
    Lipolytic enzymes with cold adaptation are gaining increasing interest due to their biotechnological prospective. Previously, a cold adapted family I.3 lipase (AMS8 lipase) was isolated from an Antarctic Pseudomonas. AMS8 lipase was largely expressed in insoluble form. The refolded His-tagged recombinant AMS8 lipase was purified with 23.0% total recovery and purification factor of 9.7. The purified AMS8 lipase migrated as a single band with a molecular weight approximately 65kDa via electrophoresis. AMS8 lipase was highly active at 30°C at pH 10. The half-life of AMS8 lipase was reported at 4 and 2h under the incubation of 30 and 40°C, respectively. The lipase was stable over a broad range of pH. It showed enhancement effect in its relative activity under the presence of Li(+), Na(+), K(+), Rb(+) and Cs(+) after 30min treatment. Heavy metal ions such as Cu(2+), Fe(3+) and Zn(2+) inhibited AMS8 activity. This cold adapted alkalophilic AMS lipase was also active in various organic solvent of different polarity. These unique properties of this biological macromolecule will provide considerable potential for many biotechnological applications and organic synthesis at low temperature.
  15. Effects of Lid 1 Mutagenesis on Lid Displacement, Catalytic Performances and Thermostability of Cold-active Pseudomonas AMS8 Lipase in Toluene
    Yaacob N, Ahmad Kamarudin NH, Leow ATC, Salleh AB, Rahman RNZRA, Ali MSM
    Comput Struct Biotechnol J, 2019;17:215-228.
    PMID: 30828413 DOI: 10.1016/j.csbj.2019.01.005
    Pseudomonas fluorescens AMS8 lipase lid 1 structure is rigid and holds unclear roles due to the absence of solvent-interactions. Lid 1 region was stabilized by 17 hydrogen bond linkages and displayed lower mean hydrophobicity (0.596) compared to MIS38 lipase. Mutating lid 1 residues, Thr-52 and Gly-55 to aromatic hydrophobic-polar tyrosine would churned more side-chain interactions between lid 1 and water or toluene. This study revealed that T52Y leads G55Y and its recombinant towards achieving higher solvent-accessible surface area and longer half-life at 25 to 37 °C in 0.5% (v/v) toluene. T52Y also exhibited better substrate affinity with long-chain carbon substrate in aqueous media. The affinity for pNP palmitate, laurate and caprylate increased in 0.5% (v/v) toluene in recombinant AMS8, but the affinity in similar substrates was substantially declined in lid 1 mutated lipases. Regarding enzyme efficiency, the recombinant AMS8 lipase displayed highest value of kcat/Km in 0.5% (v/v) toluene, mainly with pNPC. In both hydrolysis reactions with 0% and 0.5% (v/v) toluene, the enzyme efficiency of G55Y was found higher than T52Y for pNPL and pNPP. At 0.5% (v/v) toluene, both mutants showed reductions in activation energy and enthalpy values as temperature increased from 25 to 35 °C, displaying better catalytic functions. Only T52Y exhibited increase in entropy values at 0.5% (v/v) toluene indicating structure stability. As a conclusion, Thr-52 and Gly-55 are important residues for lid 1 stability as their existence helps to retain the geometrical structure of alpha-helix and connecting hinge.
  16. Parametric analysis of lignocellulosic ultrafiltration in lab scale cross flow module using pore blocking and artificial neural network model
    Yogarathinam LT, Velswamy K, Gangasalam A, Ismail AF, Goh PS, Subramaniam MN, et al.
    Chemosphere, 2022 Jan;286(Pt 3):131822.
    PMID: 34416593 DOI: 10.1016/j.chemosphere.2021.131822
    In this study, fouling mechanism and modelling analysis of synthetic lignocellulose biomass and agricultural palm oil effluent was studied using polyethersulfone (PES) ultrafiltration (UF) 10 kDa membrane. The impact of process variables (transmembrane pressure (TMP), pH and concentration of feed solution) on lignocellulosic flux was analysed using pore blocking model. The feasible approaches on utilising deep learning artificial neural network (ANN) to predict smaller flux datasets are studied. Among the input variables, pH of lignin feed solution has significant control towards flux and lignin rejection coefficient for both lignin and lignocellulosic solution. Alteration in the structure of lignin at different pH conditions contributed in the improvement of lignin rejection coefficient to 0.98 at the feed pH of 9. A maximum steady state flux of 52.03 L/m2h was observed at the lower lignin concentration (0.25 g/L), TMP of 200 kPa and feed pH of 3. At high TMP and concentration, lignin rejection decreased due to enhancement of feed concentration on membrane surface. The mechanistic model exhibited that cake layer phenomena was dominant in both lignin and lignocellulosic solution. The proposed ANN model showed good correlation (R2-1.00) with experimental non-linear flux dynamic data of both lignin and synthetic lignocellulosic solution. In ANN analysis, activation function, algorithm and neuron effect have significant effect in design of accurate model for prediction of small flux datasets. Aerobically-treated palm oil mill filtration analysis also showed that cake layer phenomenon was dominant. A water recovery of 82 % was achieved even at low TMP under short durations.
  17. Fulltext The Role of Solvent-Accessible Leu-208 of Cold-Active Pseudomonas fluorescens Strain AMS8 Lipase in Interfacial Activation, Substrate Accessibility and Low-Molecular Weight Esterification in the Presence of Toluene
    Yaacob N, Ahmad Kamarudin NH, Leow ATC, Salleh AB, Raja Abd Rahman RNZ, Mohamad Ali MS
    Molecules, 2017 Aug 12;22(8).
    PMID: 28805665 DOI: 10.3390/molecules22081312
    The alkaline cold-active lipase from Pseudomonas fluorescens AMS8 undergoes major structural changes when reacted with hydrophobic organic solvents. In toluene, the AMS8 lipase catalytic region is exposed by the moving hydrophobic lid 2 (Glu-148 to Gly-167). Solvent-accessible surface area analysis revealed that Leu-208, which is located next to the nucleophilic Ser-207 has a focal function in influencing substrate accessibility and flexibility of the catalytic pocket. Based on molecular dynamic simulations, it was found that Leu-208 strongly facilitates the lid 2 opening via its side-chain. The KM and Kcat/KM of L208A mutant were substrate dependent as it preferred a smaller-chain ester (pNP-caprylate) as compared to medium (pNP-laurate) or long-chain (pNP-palmitate) esters. In esterification of ethyl hexanoate, L208A promotes a higher ester conversion rate at 20 °C but not at 30 °C, as a 27% decline was observed. Interestingly, the wild-type (WT) lipase's conversion rate was found to increase with a higher temperature. WT lipase AMS8 esterification was higher in toluene as compared to L208A. Hence, the results showed that Leu-208 of AMS8 lipase plays an important role in steering a broad range of substrates into its active site region by regulating the flexibility of this region. Leu-208 is therefore predicted to be crucial for its role in interfacial activation and catalysis in toluene.
  18. Fulltext A new biodegradable stent in bilio-pancreatic diseases: A prospective multi-center feasibility study
    Pérez-Cuadrado Robles E, Lakhtakia S, Othman H, Tewethia HV, Yaacob N, Jarmin R, et al.
    Rev Esp Enferm Dig, 2022 Jan 11.
    PMID: 35012320 DOI: 10.17235/reed.2022.8451/2021
    Introduction Biodegradable stents of various designs are reportedly used in pancreato-biliary conditions with promising results. Their major advantage is the avoidance of a repeat endoscopic procedure for stent removal thereby reducing overall cost along with ERCP associated adverse events. To evaluate the feasibility and safety of a new biodegradable stent in patients with pancreato-biliary diseases. Methods Prospective multicenter pilot study. All consecutive patients 18 years-old who underwent biliary or pancreatic stenting using the new biodegradable Archimedes stent were included. There were three biodegradation profiles. Technical and clinical success, feasibility and safety were assessed during a pre-established follow-up schedule. Results Fifty-three patients (mean age: 48.54±19.29, 66% male) having biliary (n=29, 54.7%%) or pancreatic (n=24, 45.3%) indications were included. The distribution of stents used according to degradation properties were as follows: fast (n=11, 20.8%), medium (n=16, 30.2%) and slow (n=26, 49.1%). The technical and clinical success were 100% and 77.8%. Thirty-five patients were followed for a median of 26 weeks (range: 4-56, 66%). There were 9 procedure-related adverse events (17%), all mild, including one uneventful stent-related event (external migration). Conclusion The biodegradable Archimedes stent placement is feasible and safe in pancreato-biliary diseases.
  19. Fulltext Post-partum streptococcal toxic shock syndrome associated with necrotizing fasciitis
    Chua WC, Mazlan MZ, Ali S, Che Omar S, Wan Hassan WMN, Seevaunnantum SP, et al.
    IDCases, 2017;9:91-94.
    PMID: 28725564 DOI: 10.1016/j.idcr.2017.05.002
    We report a fatal case of post-partum streptococcal toxic shock syndrome in a patient who was previously healthy and had presented to the emergency department with an extensive blistering ecchymotic lesions over her right buttock and thigh associated with severe pain. The pregnancy had been uncomplicated, and the mode of delivery had been spontaneous vaginal delivery with an episiotomy. She was found to have septicemic shock requiring high inotropic support. Subsequently, she was treated for necrotizing fasciitis, complicated by septicemic shock and multiple organ failures. A consensus was reached for extensive wound debridement to remove the source of infection; however, this approach was abandoned due to the patient's hemodynamic instability and the extremely high risks of surgery. Both the high vaginal swab and blister fluid culture revealed Group A beta hemolytic streptococcus infection. Intravenous carbapenem in combination with clindamycin was given. Other strategies attempted for streptococcal toxic removal included continuous veno-venous hemofiltration and administration of intravenous immunoglobulin. Unfortunately, the patient's condition worsened, and she succumbed to death on day 7 of hospitalization.
  20. The satisfaction and perception of Provisionally Registered Pharmacists (PRP) towards their internship training in the Ministry of Health, Malaysia facilities: A national survey
    Syed M Haq AH, Md Yusof FA, Chan PL, Chok MCF, Phua GSY, Teoh CJ, et al.
    Curr Pharm Teach Learn, 2018 07;10(7):854-874.
    PMID: 30236423 DOI: 10.1016/j.cptl.2018.04.005
    BACKGROUND: The pharmacy internship program is designed to provide comprehensive training for interns to perform various roles in pharmacy practice. In Malaysia, the current internship program has been in place since 2004 in public health facilities, but has never been extensively evaluated.

    AIM: To assess the level of job satisfaction and perception of Provisionally Registered Pharmacists (PRP) towards the internship training provided.

    METHODS: A cross-sectional nationwide survey was conducted amongst all PRPs undergoing training between December 2015 and February 2016 to assess their level of job satisfaction and perception towards the training requirements stipulated by the Pharmacy Board of Malaysia.

    RESULTS: A total of 733 PRPs participated in the survey and the response rate was 95.8%. On the basis of the response received, 92.5% (n = 678) felt that the one year training period was 'just nice', 30.5% (n = 223) felt that the logbooks were 'too complicated', and 33.2% (n = 241) said the targets set by the Pharmacy Board of Malaysia were 'too high'. On a scale of 1 to 5, respondents rated 3.32 (SD 0.54) for mean score of job satisfaction. Significant factors influencing mean score of job satisfaction were: perceived fairness at the work place; perceived self-competence after one year of training; preceptors' competence; and pharmacy as a chosen career pathway.

    CONCLUSION: Intern pharmacists were fairly satisfied with the internship training in government facilities in the Ministry of Health, Malaysia. A review of the internship logbooks and the practicality of targets set by the Pharmacy Board warrant further improvement.

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