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Seroprevalence and risk factors of Trypanosoma evansi infection in horses in Peninsular Malaysia

Elshafie EI, Sani RA, Hassan L, Sharma R, Bashir A, Abubakar IA

Res Vet Sci, 2013 Apr;94(2):285-9.
PMID: 23021152 DOI: 10.1016/j.rvsc.2012.09.004

A cross-sectional study was designed to assess the seroprevalence and risk factors associated with Trypanosoma evansi infection among horses, using a total of 527 blood samples obtained from eight states in Peninsular Malaysia. A structured questionnaire was used to collect data on risk factors associated with T. evansi seroprevalence. The overall seroprevalence detected by card agglutination test for T. evansi (CATT/T. evansi) was 13.90% (73/527, CI: 11.2-17.1%). Female and exogenous horses showed a higher risk in association with the disease seroprevalence compared to other groups. The majority of the horse owners were not familiar with surra (85.30%). However, most of them were very cautious with the health of their animals. In conclusion, this study showed that T. evansi occurred in low frequency among horses in Peninsular Malaysia, and the good management system adopted by horse owners was probably responsible for the low T. evansi occurrence.
Myocardial collagen deposition and inflammatory cell infiltration in cats with pre-clinical hypertrophic cardiomyopathy

Khor KH, Campbell FE, Owen H, Shiels IA, Mills PC

Vet J, 2015 Feb;203(2):161-8.
PMID: 25573453 DOI: 10.1016/j.tvjl.2014.11.018

The histological features of feline hypertrophic cardiomyopathy (HCM) have been well documented, but there are no reports describing the histological features in mild pre-clinical disease, since cats are rarely screened for the disease in the early stages before clinical signs are apparent. Histological changes at the early stage of the disease in pre-clinical cats could contribute to an improved understanding of disease aetiology or progression. The aim of this study was to evaluate the histological features of HCM in the left ventricular (LV) myocardium of cats diagnosed with pre-clinical HCM. Clinically healthy cats with normal (n = 11) and pre-clinical HCM (n = 6) were identified on the basis of echocardiography; LV free wall dimensions (LVFWd) and/or interventricular septal wall (IVSd) dimensions during diastole of 6-7 mm were defined as HCM, while equivalent dimensions <5.5 mm were defined as normal. LV myocardial sections were assessed and collagen content and inflammatory cell infiltrates were quantified objectively. Multifocal areas of inflammatory cell infiltration, predominantly lymphocytes, were observed frequently in the left myocardium of cats with pre-clinical HCM. Tissue from cats with pre-clinical HCM also had a higher number of neutrophils and a greater collagen content than the myocardium of normal cats. The myocardium variably demonstrated other features characteristic of HCM, including arteriolar mural hypertrophy and interstitial fibrosis and, to a lesser extent, myocardial fibre disarray and cardiomyocyte hypertrophy. These results suggest that an inflammatory process could contribute to increased collagen content and the myocardial fibrosis known to be associated with HCM.
Fulltext A Comparison of Plain Radiography with Computer Tomography in Determining Coronal and Sagittal Alignments following Total Knee Arthroplasty

Solayar GN, Chinappa J, Harris IA, Chen DB, Macdessi SJ

Malays Orthop J, 2017 Jul;11(2):45-52.
PMID: 29021879 MyJurnal DOI: 10.5704/MOJ.1707.006

Introduction: Optimal coronal and sagittal component positioning is important in achieving a successful outcome following total knee arthroplasty (TKA). Modalities to determine post-operative alignment include plain radiography and computer tomography (CT) imaging. This study aims to determine the accuracy and reliability of plain radiographs in measuring coronal and sagittal alignment following TKA. Materials and Methods: A prospective, consecutive study of 58 patients undergoing TKA was performed comparing alignment data from plain radiographs and CT imaging. Hip-knee-angle (HKA), sagittal femoral angle (SFA) and sagittal tibial angle (STA) measurements were taken by two observers from plain radiographs and compared with CT alignment. Intra- and inter-observer correlation was calculated for each measurement. Results: Intra-observer correlation was excellent for HKA (r>0.89) with a mean difference of <1.9°. The least intra-observer correlation was for SFA (mean r=0.58) with a mean difference of 8°. Inter-observer correlation was better for HKA (r>0.95) and STA (r>0.8) compared to SFA (r=0.5). When comparing modalities (radiographs vs CT), HKA estimations for both observers showed the least maximum and mean differences while SFA observations were the least accurate. Conclusion: Radiographic estimation of HKA showed excellent intra- and inter-observer correlation and corresponds well with CT imaging. However, radiographic estimation of sagittal plane alignment was less reliably measured and correlated less with CT imaging. Plain radiography was found to be inferior to CT for estimation of biplanar prosthetic alignment following TKA.
Fulltext An Investigation into a Gear-Based Knee Joint Designed for Lower Limb Prosthesis

Bhuiyan MSH, Choudhury IA, Dahari M, Nukman Y, Dawal SZ

Appl Bionics Biomech, 2017;2017:7595642.
PMID: 28584518 DOI: 10.1155/2017/7595642

A gear-based knee joint is designed to improve the performance of mechanical-type above-knee prostheses. The gear set with the help of some bracing, and bracket arrangement, is used to enable the prosthesis to follow the residual limb movement. The motion analysis and finite-element analysis (FEA) of knee joint components are carried out to assess the feasibility of the design. The maximum stress of 29.74 MPa and maximum strain of 2.393e-004 are obtained in the gear, whereas the maximum displacement of 7.975 mm occurred in the stopper of the knee arrangement. The factor of safety of 3.5 obtained from the FE analysis indicated no possibility of design failure. The results obtained from the FE analysis are then compared with the real data obtained from the literature for a similar subject. The pattern of motion analysis results has shown a great resemblance with the gait cycle of a healthy biological limb.
Synthesis and characterization of magnetic graphene oxide for arsenic removal from aqueous solution

Sherlala AIA, Raman AAA, Bello MM

Environ Technol, 2019 May;40(12):1508-1516.
PMID: 29300679 DOI: 10.1080/09593330.2018.1424259

A magnetic graphene oxide (MGO) was developed for the adsorption of As(III) from aqueous solution. The characteristics of MGO were investigated using Fourier-transform infrared (FTIR), X-ray diffraction and field emission scanning electron microscope-E/energy-dispersive X-ray analyses. Batch adsorption experiments were designed using central composite design, and the effects of adsorbent dosage, pH, contact time and concentration of As(III) were investigated. The MGO showed an excellent performance, removing up to 99.95% of As(III) under the following condition: initial As(III) concentration = 100 mg/L, pH = 7, adsorbent dosage = 0.3 g/L and contact time = 77 min. MGO dosage and initial pH were the most significant parameters influencing the process performance. FTIR analysis of the used adsorbent confirms the adsorption of As(III) through complexation between surface functional groups of the MGO and the oxyanions of As(III). The adsorbent maintained a significant level of performance even after four cycles of adsorption. Thus, the developed MGO has the potential to be used for the abatement of arsenic pollution.
Fulltext Liver injury induced by the non-steroidal anti-inflammatory drug mefenamic acid

Somchit N, Sanat F, Gan EH, Shahrin IA, Zuraini A

Singapore Med J, 2004 Nov;45(11):530-2.
PMID: 15510325

Non-steroidal anti-inflammatory drugs (NSAIDs) are used to treat musculoskeletal disorders, inflammation and to control pain. Virtually all NSAIDs are capable of producing liver injury ranging from mild reversible elevation of liver enzymes to severe hepatic necrosis.
Scoring systems, expert assessment, and identification of risk factors for the emergence of delirium in paediatric patients: Prospective cohort study

Sari D, Widyastuti Y, Hendy HH, Dharma IA, Pancarani A, Krislee A

Med J Malaysia, 2024 Mar;79(2):151-156.
PMID: 38553919

INTRODUCTION: Emergence delirium (ED) is a transient irritative and dissociative state that arises after the cessation of anaesthesia in patients who do not respond to calming measures. There are many risk factors for ED, but the exact cause and underlying mechanism have not been determined because the definition of ED is still unclear in consensus. This study aims to determine ED incidence, identify ED risk factors and external validation of Watcha, Cravero and expert assessment to Pediatric Anesthesia Emergence Delirium (PAED) scoring system in ED prediction.
MATERIALS AND METHODS: This study is a prospective cohort study on 79 paediatrics who underwent elective surgery with general anaesthesia. Parameter measures include the incidence of ED, ED risk factors, and the relationship between PAED, Watcha, Cravero score and expert assessment. The ED risk factor was analysed using univariate and multivariate analysis. The relationship between PAED, Watcha, Cravero score, and expert assessment was determined using Receiver Operating Characteristic (ROC) curve analysis.
RESULTS: The incidence of ED was 22.8%. All parameters examined in this study showed p < 0.05. Watcha's scoring correlates with the PAED scoring and shows the highest discrimination ability with AUC 0.741 and p < 0.05.
CONCLUSION: The incidence of ED in paediatrics is relatively high. Compared to others, Watcha score are more reliable for ED prediction. However, some demographic and perioperative factors are not the risk factor of ED.
Fulltext Painful Pes Anserine Bursitis Following Total Knee Replacement Surgery: Two cases

Ariff MAM, Ros MIAC, Yahaya NHM

Sultan Qaboos Univ Med J, 2018 Feb;18(1):e97-e99.
PMID: 29666689 DOI: 10.18295/squmj.2018.18.01.016

Pes anserine bursitis (PAB) is an inflammation of the bursa located between the medial aspect of the tibia and the hamstring muscles. It is common in patients with degenerative or inflammatory knee arthritis, usually has a self-limiting course and tends to respond well to conservative treatment. However, painful PAB directly following total knee replacement surgery is rare. We report two such cases who were diagnosed via ultrasonography at the Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Malaysia, in 2015. Both patients were treated locally with triamcinolone acetonide under ultrasound guidance and responded well to treatment.
Fulltext Influence of forced-air precooling time on the changes in quality attributes and consumer acceptance of Musa AAA Berangan

Kuan, C.H., Ahmad, S. H., Son, R., Yap, E. S. P., Zamri, M. Z., Shukor, N. I. A., et al.

International Food Research Journal, 2015;22(5):1864-1869.
MyJurnal

A good temperature management, such as precooling and cold storage, can delay deterioration of fresh produce. In this study, different forced-air precooling times were applied on Musa AAA Berangan to investigate the influence of forced-air precooling time on the changes of quality attributes and consumer acceptance. The banana was subjected to forced-air precooling treatment (5 ± 1°C) for 0, 14, 50, and 120 min and then stored in a cold room (13 ± 1°C) for 2 weeks. Then, all the fruits were transferred to a ripening room (25 ± 2°C) and initiated to ripen with ethylene gas. Quality attributes analyses and sensory evaluations were conducted when the fruits reached maturity index 5. Quality parameters, such as soluble solids concentration, titratable acidity, pulp firmness, and peel colour, showed no significant differences when fruits were precooled at different times. Blackening of peel as a result of chilling injury occurred in fruits treated with forced-air precooling for 50 and 120 min. This blackening significantly influenced consumer acceptance, although it did not affect the pulp colour and taste.
Educating medical students in oral health care: current curriculum and future needs of institutions in Malaysia and Australia

Ahmad MS, Abuzar MA, Razak IA, Rahman SA, Borromeo GL

Eur J Dent Educ, 2017 Nov;21(4):e29-e38.
PMID: 27273317 DOI: 10.1111/eje.12211

Poor oral health has been associated with compromised general health and quality of life. To promote comprehensive patient management, the role of medical professionals in oral health maintenance is compelling, thus indicating the need for educational preparation in this area of practice. This study aimed to determine the extent of training in oral health in Malaysian and Australian medical schools. An audio-recorded semi-structured phone interview involving Academic Programme Directors in Malaysian (n = 9, response rate=81.8%) and Australian (n = 7, response rate = 35.0%) medical schools was conducted during the 2014/2015 and 2014 academic years, respectively. Qualitative data was analysed via thematic analysis, involving coding and grouping into emerging themes. Quantitative data were measured for frequencies. It was found that medical schools in Malaysia and Australia offered limited teaching of various oral health-related components that were mostly integrated throughout the curriculum, in the absence of structured learning objectives, teaching methodologies and assessment approaches. Barriers to providing oral health education included having insufficient expertise and overloaded curriculum. As medical educators demonstrated support for oral health education, collaboration amongst various stakeholders is integral to developing a well-structured curriculum and practice guidelines on oral health management involving medical professionals.
Fulltext A pilot randomized control cross over study evaluating the effectiveness and safety of mechanical percussor compared with conventional chest physiotherapy in adults with productive cough

Punithavathi N, Ong LM, Irfhan Ali HA, Mohd Izmi IA, Dharminy T, Ang AH, et al.

Med J Malaysia, 2014 Feb;69(1):16-20.
PMID: 24814623 MyJurnal

INTRODUCTION: Conventional Chest Physiotherapy (CCPT) remains the mainstay of treatment for sputum mobilization in patients with productive cough such as bronchiectasis and "Chronic Obstructive Airway Disease" (COPD). However CCPT is time consuming requires the assistance of a physiotherapist and limits the independence of the patient. Mechanical percussors which are electrical devices used to provide percussion to the external chest wall might provide autonomy and greater compliance. We compared safety and efficacy of a mechanical chest percusser devised by Formedic Technology with conventional chest percussion.
METHODS: Twenty patients (mean age 64years) were randomly assigned to receive either CCPT or mechanical percussor on the first day and crossed over by "Latin square randomisation" to alternative treatment for 6 consecutive days and the amount of sputum expectorated was compared by dry and wet weight. Adverse events and willingness to use was assessed by a home diary and a questionnaire.
RESULTS: There were 13 males and 7 females, eight diagnosed as bronchiectasis and 12 COPD. The mean dry weight of sputum induced by CCPT (0.54g ± 0.32) was significantly more compared with MP (0.40g + 0.11); p-value = 0.002. The mean wet weight of sputum with CCPT (10.71g ± 8.70) was also significantly more compared with MP (5.99g ± 4.5); p-value < 0.001. There were no significant difference in adverse events and majority of patients were willing to use the device by themselves.
CONCLUSION: The mechanical percussor although produces less sputum is well tolerated and can be a useful adjunct to CCPT.
Accuracy of MRI in the diagnosis of meniscal tears in patients with chronic ACL tears

Sharifah MI, Lee CL, Suraya A, Johan A, Syed AF, Tan SP

Knee Surg Sports Traumatol Arthrosc, 2015 Mar;23(3):826-30.
PMID: 24240983 DOI: 10.1007/s00167-013-2766-7

PURPOSE: This study was conducted to evaluate the accuracy of magnetic resonance imaging (MRI) in diagnosing meniscal tears in patients with anterior cruciate ligament (ACL) tears and to determine the frequency of missed meniscal tears on MRI.
METHODS: This prospective comparative study was conducted from 2009 to 2012. Patients with ACL injuries who underwent knee arthroscopy and MRI were included in the study. Two radiologists who were blinded to the clinical history and arthroscopic findings reviewed the pre-arthroscopic MR images. The presence and type of meniscal tears on MRI and arthroscopy were recorded. Arthroscopic findings were used as the reference standard. The accuracy, sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of MRI in the evaluation of meniscal tears were calculated.
RESULTS: A total of 65 patients (66 knees) were included. The sensitivity, specificity, accuracy, PPV, and NPV for the MRI diagnosis of lateral meniscal tears in our patients were 83, 97, 92, 96, and 90 %, respectively, whereas those for medial meniscus tears were 82, 92, 88, 82, and 88 %, respectively. There were five false-negative diagnoses of medial meniscus tears and four false-negative diagnoses of lateral meniscus tears. The majority of missed meniscus tears on MRI affected the peripheral posterior horns.
CONCLUSION: The sensitivity for diagnosing a meniscal tear was significantly higher when the tear involved more than one-third of the meniscus or the anterior horn. The sensitivity was significantly lower for tears located in the posterior horn and for vertically oriented tears. Therefore, special attention should be given to the peripheral posterior horns of the meniscus, which are common sites of injury that could be easily missed on MRI. The high NPVs obtained in this study suggest that MRI is a valuable tool prior to arthroscopy.
An improved enzyme assay for molybdenum-reducing activity in bacteria

Shukor MY, Rahman MF, Shamaan NA, Lee CH, Karim MI, Syed MA

Appl Biochem Biotechnol, 2008 Mar;144(3):293-300.
PMID: 18556818

Molybdenum-reducing activity in the heterotrophic bacteria is a phenomenon that has been reported for more than 100 years. In the presence of molybdenum in the growth media, bacterial colonies turn to blue. The enzyme(s) responsible for the reduction of molybdenum to molybdenum blue in these bacteria has never been purified. In our quest to purify the molybdenum-reducing enzyme, we have devised a better substrate for the enzyme activity using laboratory-prepared phosphomolybdate instead of the commercial 12-phosphomolybdate we developed previously. Using laboratory-prepared phosphomolybdate, the highest activity is given by 10:4-phosphomolybdate. The apparent Michaelis constant, Km for the laboratory-prepared 10:4-phosphomolybdate is 2.56 +/- 0.25 mM (arbitrary concentration), whereas the apparent V(max) is 99.4 +/- 2.85 nmol Mo-blue min(-1) mg(-1) protein. The apparent Michaelis constant or Km for NADH as the electron donor is 1.38 +/- 0.09 mM, whereas the apparent V(max) is 102.6 +/- 1.73 nmol Mo-blue min(-1) mg(-l) protein. The apparent Km and V(max) for another electron donor, NADPH, is 1.43 +/- 0.10 mM and 57.16 +/- 1.01 nmol Mo-blue min(-1) mg(-1) protein, respectively, using the same batch of molybdenum-reducing enzyme. The apparent V(max) obtained for NADH and 10:4-phosphomolybdate is approximately 13 times better than 12-phoshomolybdate using the same batch of enzyme, and hence, the laboratory-prepared phosphomolybdate is a much better substrate than 12-phoshomolybdate. In addition, 10:4-phosphomolybdate can be routinely prepared from phosphate and molybdate, two common chemicals in the laboratory.
Proteomics of Grade 3 infiltrating ductal carcinoma in Malaysian Chinese breast cancer patients

Othman MI, Majid MI, Singh M, Subathra S, Seng L, Gam LH

Biotechnol Appl Biochem, 2009 Mar;52(Pt 3):209-19.
PMID: 18564057 DOI: 10.1042/BA20070271

Breast cancer is the leading cause of cancer-related mortality and morbidity among women worldwide and IDC (infiltrating ductal carcinoma) is the most common type of invasive breast cancer. The changes in the biological behaviour of cancer tissue can be predicted by measuring the differential protein expression of normal and cancerous tissues. Using a combination of SDS/PAGE and LC (liquid chromatography)-MS/MS (tandem MS), we identified 82 common and differentially expressed proteins from normal and cancerous breast tissues in 20 Malaysian Chinese patients with IDC. These proteins are extracted from the normal and cancerous tissue of patients and therefore represent the actual proteins involved in cancer development. Proteins identified possibly have significant roles in the development of breast cancer in Malaysian Chinese patients in view of their consistent expression in most of the patients, although some of the proteins had not been detected in earlier studies that were mostly carried out in Western countries. This observation suggests that molecular mechanisms leading to breast cancer development in this region may not be identical with those leading to IDC in Western regions.
Fulltext Isolation, identification and quantification of differentially expressed proteins from cancerous and normal breast tissues

Othman MI, Majid MI, Singh M, Man CN, Lay-Harn G

Ann. Clin. Biochem., 2008 May;45(Pt 3):299-306.
PMID: 18482919 DOI: 10.1258/acb.2007.007104

Infiltrating ductal carcinoma (IDCA) is the most common type of breast cancer accounting for 85% of all invasive breast cancers.
Antinociceptive and anti-inflammatory activities of the aqueous extract of Kaempferia galanga leaves in animal models

Sulaiman MR, Zakaria ZA, Daud IA, Ng FN, Ng YC, Hidayat MT

J Nat Med, 2008 Apr;62(2):221-7.
PMID: 18404328 DOI: 10.1007/s11418-007-0210-3

This study was performed to determine the antinociceptive and anti-inflammatory activities of aqueous extract of Kaempferia galanga leaves using various animal models. The extract, in the doses of 30, 100, and 300 mg/kg, was prepared by soaking (1:10; w/v) the air-dried powdered leaves (40 g) in distilled water (dH(2)O) for 72 h and administered subcutaneously in mice/rats 30 min prior to the tests. The extract exhibited significant (P < 0.05) antinociceptive activity when assessed using the abdominal constriction, hot-plate and formalin tests, with activity observed in all tests occurring in a dose-dependent manner. Furthermore, the antinociceptive activity of K. galanga extract was significantly (P < 0.05) reversed when prechallenged with 10 mg/kg naloxone. The extract also produced a significantly (P < 0.05) dose-dependent anti-inflammatory activity when assessed using the carrageenan-induced paw-edema test. In conclusion, this study demonstrated that K. galanga leaves possessed antinociceptive and anti-inflammatory activities and thus supports the Malay's traditional uses of the plant for treatments of mouth ulcer, headache, sore throat, etc.
Typhonium flagelliforme inhibits cancer cell growth in vitro and induces apoptosis: an evaluation by the bioactivity guided approach

Lai CS, Mas RH, Nair NK, Majid MI, Mansor SM, Navaratnam V

J Ethnopharmacol, 2008 Jun 19;118(1):14-20.
PMID: 18436400 DOI: 10.1016/j.jep.2008.02.034

Typhonium flagelliforme (Lodd.) Blume (Araceae) is a Malaysian plant used locally to combat cancer. In order to evaluate its antiproliferative activity in vitro and to possibly identify the active chemical constituents, a bioactivity guided study was conducted on the extracts of this plant.
Clonidine and a novel clonidine analog AL-12 cause sympathoinhibition in spontaneously hypertensive and diabetic spontaneously hypertensive rats

Lazahari MI, Sattar MA, Abdullah NA, Khan MA, Johns EJ

Methods Find Exp Clin Pharmacol, 2008 Apr;30(3):193-9.
PMID: 18597003 DOI: 10.1358/mf.2008.30.3.1166221

This study examined the sympathoinhibitory effects of clonidine and a novel clonidine analog, AL-12, in rat models of genetic hypertension and a combined state of genetic hypertension and diabetes. Rats in the treatment groups were given either clonidine or AL-12 while the respective control groups received either saline or Tween 80 for 6 days. Physiological data were collected during this period, which was followed by acute studies on day 7 when bolus administrations (i.v.) of graded doses of noradrenaline, phenylephrine and methoxamine were carried out. It was observed that in AL-12-treated nondiabetic spontaneously hypertensive rats (SHR), the pressure responses to all adrenergic agonists were greater (p < 0.05) in the treated group, while in the diabetic SHR rats a larger pressure response was observed only to noradrenaline (p < 0.05). In nondiabetic SHR rats treated with clonidine, a greater (p < 0.05) pressure response was observed only in the case of phenylephrine. In the diabetic SHR rats treated with clonidine, the pressure responses to the adrenergic agonists were similar (p > 0.05) in the treated and its control animals except that methoxamine caused a greater (p < 0.05) pressure response in the control group. The data obtained suggest that clonidine and AL-12 act possibly via vascular alpha1 and alpha2 adrenoceptors present at both pre- and postsynaptic locations.
Biosynthesis of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer by Cupriavidus sp. USMAA1020 isolated from Lake Kulim, Malaysia

Amirul AA, Yahya AR, Sudesh K, Azizan MN, Majid MI

Bioresour Technol, 2008 Jul;99(11):4903-9.
PMID: 17981028

Cupriavidus sp. USMAA1020 was isolated from Malaysian environment and able to synthesize poly(3-hydroxybutyrate-co-4-hydroxybutyrate), [P(3HB-co-4HB)] when grown on gamma-butyrolactone as the sole carbon source. The polyester was purified from freeze-dried cells and analyzed by nuclear magnetic resonance (NMR) spectroscopy. 1H and 13C NMR results confirmed the presence of 3HB and 4HB monomers. In a one-step cultivation process, P(3HB-co-4HB) accumulation by Cupriavidus sp. USMAA1020 was affected by carbon to nitrogen ratio (C/N). A two-step cultivation process accumulated P(3HB-co-4HB) copolyester with a higher 4HB fraction (53 mol%) in nitrogen-free mineral medium containing gamma-butyrolactone. The biosynthesis of P(3HB-co-4HB) was also achieved by using 4-hydroxybutyric acid and alkanediol as 1,4-butanediol. The composition of copolyesters varied from 32 to 51 mol% 4HB, depending on the carbon sources supplied. The copolyester produced by Cupriavidus sp. USMAA1020 has a random sequence distribution of 3-hydroxybutyrate (3HB) and 4-hydroxybutyrate (4HB) units when analyzed by nuclear magnetic resonance (NMR) spectroscopy. When gamma-butyrolactone was used as the sole carbon source, the 4HB fraction in copolyester increased from 25 to 60 mol% as the concentration of gamma-butyrolactone in the culture medium increased from 2.5 g/L to 20.0 g/L.
Optimization and validation of RP-HPLC-UV method with solid-phase extraction for determination of buparvaquone in human and rabbit plasma: application to pharmacokinetic study

Venkatesh G, Majid MI, Ramanathan S, Mansor SM, Nair NK, Croft SL, et al.

Biomed Chromatogr, 2008 May;22(5):535-41.
PMID: 18205140 DOI: 10.1002/bmc.965

A simple, sensitive and specific reversed-phase high-performance liquid chromatographic method with UV detection at 251 nm was developed for quantitation of buparvaquone (BPQ) in human and rabbit plasma. The method utilizes 250 microL of plasma and sample preparation involves protein precipitation followed by solid-phase extraction. The method was validated on a C18 column with mobile phase consisting of ammonium acetate buffer (0.02 m, pH 3.0) and acetonitrile in the ratio of 18:82 (v/v) at a flow rate of 1.1 mL/min. The calibration curves were linear (correlation coefficient>or=0.998) in the selected range. The method is specific and sensitive with limit of quantitation of 50 ng/mL for BPQ. The validated method was found to be accurate and precise in the working calibration range. Stability studies were carried out at different storage conditions and BPQ was found to be stable. Partial validation studies were carried out using rabbit plasma and intra- and inter-day precision and accuracy were within 7%. This method is simple, reliable and can be routinely used for preclinical pharmacokinetic studies for BPQ.

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