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A new expandable cannula system for endoscopic evacuation of intraparenchymal hemorrhages

Waran V, Vairavan N, Sia SF, Abdullah B

J. Neurosurg., 2009 Dec;111(6):1127-30.
PMID: 19408977 DOI: 10.3171/2009.4.JNS081506

The authors describe a newly developed expandable cannula to enable a more efficient use of an endoscope in removing intraparenchymal spontaneous hypertensive intracerebral hematomas. The cannula is introduced like a conventional brain cannula, using neuronavigation techniques to reach the targeted hematoma accurately, and, once deployed, conventional microsurgical techniques are used under direct endoscopic visualization. This method was used in 6 patients, and, based on the results of intraoperative intracranial pressure monitoring and postoperative CT scanning, the authors were able to achieve good hematoma removal. They found that by using the expandable cannula, efficient endoscopic surgery in the brain parenchyma was possible.

Matched MeSH terms: Intracranial Pressure
Fulltext Severe traumatic brain injury: outcome in patients with diffuse axonal injury managed conservatively in Hospital Sultanah Aminah, Johor Bahru--an observational study

Liew BS, Johari SA, Nasser AW, Abdullah J

Med J Malaysia, 2009 Dec;64(4):280-8.
PMID: 20954551

Patients with isolated severe head injury with diffuse axonal injury and without any surgical lesion may be treated safely without cerebral resuscitation and intracranial pressure (ICP) monitoring. Seventy two patients were divided into three groups of patients receiving treatment based on ICP-CPP-targeted, or conservative methods either with or without ventilation support. The characteristics of these three groups were compared based on age, gender, Glasgow Coma Scale (GCS), pupillary reaction to light, computerized tomography scanning according to the Marshall classification, duration of intensive care unit (ICU) stays, Glasgow Outcome Score (GOS) and possible complications. There were higher risk of mortality (p < 0.001), worse GCS improvement upon discharge (p < 0.001) and longer ICU stays (p = 0.016) in ICP group compared to Intubation group. There were no significant statistical differences of GOS at 3rd and 6th months between all three groups.

Matched MeSH terms: Intracranial Pressure
Effects of asiatic acid on passive and active avoidance task in male Spraque-Dawley rats

Nasir MN, Habsah M, Zamzuri I, Rammes G, Hasnan J, Abdullah J

J Ethnopharmacol, 2011 Mar 24;134(2):203-9.
PMID: 21167268 DOI: 10.1016/j.jep.2010.12.010

Centella asiatica has a reputation to restore declining cognitive function in traditional medicine. To date, only a few compounds that show enhancing learning and memory properties are available. Therefore, the present study investigates the effects of for acute administration of asiatic acid (A-A) isolated from Centella asiatica administration on memory and learning in male Spraque-Dawley rats.

Matched MeSH terms: Blood Pressure/drug effects
Acute toxicity study of the standardized methanolic extract of Mitragyna speciosa Korth in rodent

Harizal SN, Mansor SM, Hasnan J, Tharakan JK, Abdullah J

J Ethnopharmacol, 2010 Sep 15;131(2):404-9.
PMID: 20643198 DOI: 10.1016/j.jep.2010.07.013

ETHNOPHARMACOLOGICAL RELEVANCE: Mitragyna speciosa Korth (ketum) is widely used in Malaysia as a medicinal agent for treating diarrhea, worm infestations and also acts as an analgesic and antipyretic.
AIM: The aim of the study is to determine the acute toxicity of Mitragyna speciosa Korth standardized methanol extract in vivo in 4-weeks-old Sprague-Dawley rats.
METHODOLOGY: Rats were orally administrated single dose of 100, 500 and 1000 mg/kg Mitragyna speciosa Korth standardized methanol extract and the control group received 430 mg/kg of morphine orally. There were 10 rats in each group. All animals were sacrificed after 14 days of treatment. Eight parameters were tested: cage side observation, body weight measurement, food and water consumption, blood pressure, absolute and relative organ weight, hematology, biochemical analysis and histopathology, to look for evidence of toxicity.
RESULT: No mortality was noted after 14 days of treatment. In general, behavior, food and water consumption, hematological studies and organ weights showed no significant changes. The standardized methanol extraction of Mitragyna speciosa Korth increased rat blood pressure (systolic: 147.4+/-1.01, 131.64+/-4.94 and 137.8+/-4.46) after an hour of 100, 500 and 1000 mg/kg doses, respectively. Biochemical studies showed significant elevation of ALT, AST, albumin, triglycerides, cholesterol and albumin (p>0.05), at all levels of doses. But, nephrotoxicity evidenced by elevated creatinine was seen only at a dose of 1000 mg/kg. Histological examination showed congestion of sinusoids, hemorrhage hepatocytes, fatty change, centrilobular necrosis and increased number of Kuppfer cells in the liver of all Mitragyna speciosa Korth standardized methanol extract treated groups.
CONCLUSION: Oral administration of standardized methanolic extraction of Mitragyna speciosa Korth resulted in increasing rat blood pressure after an hour of drug administration. The highest dose of extract also induced acute severe hepatotoxicity and mild nephrotoxicity. However, Mitragyna speciosa Korth shows no effects on body weight, food and water consumption, absolute and relative organ weight and also hematology parameters.

Matched MeSH terms: Blood Pressure/drug effects*
Cerebrospinal fluid nitric oxide metabolite levels as a biomarker in severe traumatic brain injury

Kandasamy R, Kanti Pal H, Swamy M, Abdullah J

Int J Neurosci, 2013 Jun;123(6):385-91.
PMID: 23270401 DOI: 10.3109/00207454.2012.761983

Nitric oxide has a definitive role in the complex pathophysiology of traumatc brain injury (TBI). This prospective cohort study investigated the changes in nitric oxide metabolite (NOx) levels in cerebrospinal fluid (CSF) and their correlation with factors associated with severity and prognosis after severe TBI. NOx levels were measured in CSF obtained via ventriculostomy in 44 adult patients admitted after severe TBI (Glasgow Coma Scale ≤ 8/15). The overall mean level of CSF NOx in the study population was 7.40 ± 1.59 μmol/L. Levels of CSF NOx were found to be significantly higher in subgroups of patients with poorer outcome measured by Glasgow Outcome Scale score (p < 0.042), in patients with high intracranial pressure (ICP) readings (p < 0.027) and in those with higher Marshall computed tomography (CT) grading scores (p < 0.026). Simple logistic regression demonstrated that CSF NOx levels were a significant predictor of ICP (b = 0.493, 95%CI: 1.03, 2.58, p = 0.033). A patient with 1 μmol/L increase in NOx level had 1.6 times the odds to have an ICP ≥ 20 mmHg when other confounders were not adjusted. NOx level is also a significant predictor of Marshall CT grading (b = 0.473, 95%CI: 1.02, 2.50, p = 0.037). A patient with 1 μmol/L increase in NOx level had 1.6 times the odds to have a high Marshall grade when other confounders were not adjusted. It can be concluded that CSF NOx levels may serve as a potentially useful biomarker in severe TBI given its significant association with ICP readings as well as Marshall CT grading.

Matched MeSH terms: Intracranial Pressure/physiology
Micromechanical modelling of oil palm empty fruit bunch fibres containing silica bodies

Omar FN, Hanipah SH, Xiang LY, Mohammed MAP, Baharuddin AS, Abdullah J

J Mech Behav Biomed Mater, 2016 09;62:106-118.
PMID: 27183430 DOI: 10.1016/j.jmbbm.2016.04.043

Experimental and numerical investigation was conducted to study the micromechanics of oil palm empty fruit bunch fibres containing silica bodies. The finite viscoelastic-plastic material model called Parallel Rheological Network model was proposed, that fitted well with cyclic and stress relaxation tensile tests of the fibres. Representative volume element and microstructure models were developed using finite element method, where the models information was obtained from microscopy and X-ray micro-tomography analyses. Simulation results showed that difference of the fibres model with silica bodies and those without ones is larger under shear than compression and tension. However, in comparison to geometrical effect (i.e. silica bodies), it is suggested that ultrastructure components of the fibres (modelled using finite viscoelastic-plastic model) is responsible for the complex mechanical behaviour of oil palm fibres. This can be due to cellulose, hemicellulose and lignin components and the interface behaviour, as reported on other lignocellulosic materials.

Matched MeSH terms: Pressure
Outcome of severe traumatic brain injury: comparison of three monitoring approaches

Isa R, Wan Adnan WA, Ghazali G, Idris Z, Ghani AR, Sayuthi S, et al.

Neurosurg Focus, 2003 Dec 15;15(6):E1.
PMID: 15305837

The determination of cerebral perfusion pressure (CPP) is regarded as vital in monitoring patients with severe traumatic brain injury. Besides indicating the status of cerebral blood flow (CBF), it also reveals the status of intracranial pressure (ICP). The abnormal or suboptimal level of CPP is commonly correlated with high values of ICP and therefore with poor patient outcomes. Eighty-two patients were divided into three groups of patients receiving treatment based on CPP and CBF, ICP alone, and conservative methods during two different observation periods. The characteristics of these three groups were compared based on age, sex, time between injury and hospital arrival, Glasgow Coma Scale score, pupillary reaction to light, surgical intervention, and computerized tomography scanning findings according to the Marshall classification system. Only time between injury and arrival (p = 0.001) was statistically significant. There was a statistically significant difference in the proportions of good outcomes between the multimodality group compared with the group of patients that underwent a single intracranial-based monitoring method and the group that received no monitoring (p = 0.003) based on a disability rating scale after a follow up of 12 months. Death was the focus of outcome in this study in which the multimodality approach to monitoring had superior results.

Matched MeSH terms: Blood Pressure; Intracranial Pressure
Fulltext Intracranial bleeding following induction of anesthesia in a patient undergoing elective surgery for refractory epilepsy

Kandasamy R, Tharakan J, Idris Z, Abdullah JM

Surg Neurol Int, 2013;4:124.
PMID: 24232072 DOI: 10.4103/2152-7806.119006

BACKGROUND: A patient with refractory epilepsy due to underlying mesial temporal sclerosis underwent general anesthesia for an elective anterior temporal lobectomy and amgydalo-hippocampectomy. He was a known hypertensive and his blood pressure was well controlled on medication.
CASE DESCRIPTION: Following induction of general anesthesia and subsequent opening of the craniotomy flap it was noted that the patient had a very swollen brain that herniated out of the dural defect. There was an underlying spontaneous intraparenchymal bleed encountered in the region of the left temporal lobe with associated subarachnoid hemorrhage within the sylvian fissure. The clot was evacuated and subsequently brain swelling reduced allowing us to proceed with the intended surgery. Despite the intracranial findings there was no overt abnormality in the hemodynamic status from the time of induction of anesthesia to the craniotomy opening excepting a mild nonsustained elevation of blood pressure at the outset.
CONCLUSION: This case is of interest due to the fact that spontaneous intraparenchymal bleeding after induction of anesthesia has not been reported before in literature and should be considered in any patient in which brain swelling occurs in a setting of elective neurosurgery in which the primary lesion does not cause elevated intracranial pressure.

Matched MeSH terms: Blood Pressure; Blood Pressure Determination
Optic nerve sheath diameter measurement: a means of detecting raised ICP in adult traumatic and non-traumatic neurosurgical patients

Raffiz M, Abdullah JM

Am J Emerg Med, 2017 Jan;35(1):150-153.
PMID: 27852525 DOI: 10.1016/j.ajem.2016.09.044

INTRODUCTION: Bedside ultrasound measurement of optic nerve sheath diameter (ONSD) is emerging as a non-invasive technique to evaluate and predict raised intracranial pressure (ICP). It has been shown in previous literature that ONSD measurement has good correlation with surrogate findings of raised ICP such as clinical and radiological findings suggestive of raised ICP.
OBJECTIVES: The objective of the study is to find a correlation between sonographic measurements of ONSD value with ICP value measured via the gold standard invasive intracranial ICP catheter, and to find the cut-off value of ONSD measurement in predicting raised ICP, along with its sensitivity and specificity value.
METHODS: A prospective observational study was performed using convenience sample of 41 adult neurosurgical patients treated in neurosurgical intensive care unit with invasive intracranial pressure monitoring placed in-situ as part of their clinical care. Portable SonoSite ultrasound machine with 7 MHz linear probe were used to measure optic nerve sheath diameter using the standard technique. Simultaneous ICP readings were obtained directly from the invasive monitoring.
RESULTS: Seventy-five measurements were performed on 41 patients. The non-parametric Spearman correlation test revealed a significant correlation at the 0.01 level between the ICP and ONSD value, with correlation coefficient of 0.820. The receiver operating characteristic curve generated an area under the curve with the value of 0.964, and with standard error of 0.22. From the receiver operating characteristic curve, we found that the ONSD value of 5.205 mm is 95.8% sensitive and 80.4% specific in detecting raised ICP.
CONCLUSIONS: ONSD value of 5.205 is sensitive and specific in detecting raised ICP. Bedside ultrasound measurement of ONSD is readily learned, and is reproducible and reliable in predicting raised ICP. This non-invasive technique can be a useful adjunct to the current invasive intracranial catheter monitoring, and has wide potential clinical applications in district hospitals, emergency departments and intensive care units.

Matched MeSH terms: Intracranial Pressure
Fulltext Germinated Brown Rice Alters Aβ(1-42) Aggregation and Modulates Alzheimer's Disease-Related Genes in Differentiated Human SH-SY5Y Cells

Azmi NH, Ismail M, Ismail N, Imam MU, Alitheen NB, Abdullah MA

Evid Based Complement Alternat Med, 2015;2015:153684.
PMID: 26858770 DOI: 10.1155/2015/153684

The pathogenesis of Alzheimer's disease involves complex etiological factors, of which the deposition of beta-amyloid (Aβ) protein and oxidative stress have been strongly implicated. We explored the effects of H2O2, which is a precursor for highly reactive hydroxyl radicals, on neurotoxicity and genes related to AD on neuronal cells. Candidate bioactive compounds responsible for the effects were quantified using HPLC-DAD. Additionally, the effects of germinated brown rice (GBR) on the morphology of Aβ(1-42) were assessed by Transmission Electron Microscopy and its regulatory effects on gene expressions were explored. The results showed that GBR extract had several phenolic compounds and γ-oryzanol and altered the structure of Aβ(1-42) suggesting an antiamyloidogenic effect. GBR was also able to attenuate the oxidative effects of H2O2 as implied by reduced LDH release and intracellular ROS generation. Furthermore, gene expression analyses showed that the neuroprotective effects of GBR were partly mediated through transcriptional regulation of multiple genes including Presenilins, APP, BACE1, BACE2, ADAM10, Neprilysin, and LRP1. Our findings showed that GBR exhibited neuroprotective properties via transcriptional regulation of APP metabolism with potential impact on Aβ aggregation. These findings can have important implications for the management of neurodegenerative diseases like AD and are worth exploring further.

Matched MeSH terms: Chromatography, High Pressure Liquid
Fulltext Optimizing supercritical antisolvent process parameters to minimize the particle size of paracetamol nanoencapsulated in L-polylactide

Kalani M, Yunus R, Abdullah N

Int J Nanomedicine, 2011;6:1101-5.
PMID: 21698077 DOI: 10.2147/IJN.S18979

The aim of this study was to optimize the different process parameters including pressure, temperature, and polymer concentration, to produce fine small spherical particles with a narrow particle size distribution using a supercritical antisolvent method for drug encapsulation. The interaction between different process parameters was also investigated.

Matched MeSH terms: Pressure
Interaction between irbesartan, peroxisome proliferator-activated receptor (PPAR-γ), and adiponectin in the regulation of blood pressure and renal function in spontaneously hypertensive rats

Afzal S, Sattar MA, Johns EJ, Abdulla MH, Akhtar S, Hashmi F, et al.

J Physiol Biochem, 2016 Dec;72(4):593-604.
PMID: 27405250

Adiponectin exerts vasodilatory effects. Irbesartan, an angiotensin receptor blocker, possesses partial peroxisome proliferator-activated receptor gamma (PPAR-γ) agonist activity and increases circulating adiponectin. This study explored the effect of irbesartan alone and in combination with adiponectin on blood pressure, renal hemodynamic excretory function, and vasoactive responses to angiotensin II and adrenergic agonists in spontaneously hypertensive rat (SHR). Irbesartan was given orally (30 mg/kg/day) for 28 days and adiponectin intraperitoneally (2.5 μg/kg/day) for last 7 days. Groups of SHR received either irbesartan or adiponectin or in combination. A group of Wistar Kyoto rats (WKY) served as controls. Metabolic data and plasma samples were taken on days 0, 21, and 28. In acute studies, the renal vasoconstrictor actions of angiotensin II (ANGII), noradrenaline (NA), phenylephrine (PE), and methoxamine (ME) were determined. SHR control rats had a higher mean blood pressure than the WKY (132 ± 7 vs. 98 ± 2 mmHg), lower plasma and urinary adiponectin, creatinine clearance, urine flow rate and sodium excretion, and oxidative stress markers compared to WKY (all P

Matched MeSH terms: Blood Pressure/drug effects
Fulltext Exposure to High-Fat Style Diet Induced Renal and Liver Structural Changes, Lipid Accumulation and Inflammation in Intact and Ovariectomized Female Rats

Sucedaram Y, Johns EJ, Husain R, Abdul Sattar M, H Abdulla M, Nelli G, et al.

J Inflamm Res, 2021;14:689-710.
PMID: 33716510 DOI: 10.2147/JIR.S299083

Purpose: We hypothesized that low estrogen levels aggravate obesity-related complications. Diet-induced obesity can cause distinct pathologies, including impaired glucose tolerance, inflammation, and organ injury that leads to fatty liver and chronic kidney diseases. To test this hypothesis, ovariectomized (OVX) rats were fed a high-fat style diet (HFSD), and we examined structural changes and inflammatory response in the kidney and liver.
Methods: Sprague-Dawley female rats were ovariectomized or sham-operated and divided into four groups: sham-operated rats fed a normal diet (ND); ovariectomized rats fed a normal diet (OVX-ND); sham-operated rats fed a HFSD; ovariectomized rats fed a high-fat style diet (OVX-HFSD). Mean blood pressure and fasting blood glucose were measured on weeks 0 and 10. The rats were sacrificed 10 weeks after initiation of ND or HFSD, the kidney and liver were harvested for histological, immunohistochemical and immunofluorescence studies.
Results: HFSD-fed rats presented a significantly greater adiposity index compared to their ND counterparts. Liver index, fasting blood glucose and mean blood pressure was increased in OVX-HFSD rats compared to HFSD rats at study terminal. Histological and morphometric studies showed focal interstitial mononuclear cell infiltration in the kidney of HFSD rats with mesangial expansion being greater in the OVX-HFSD rats. Both HFSD fed groups showed increased expressions of renal inflammatory markers, namely TNF-alpha, IL-6 and MCP-1, and infiltrating M1 macrophages with some influence of ovarian hormonal status. HFSD-feeding also caused hepatocellular steatosis which was aggravated in ovariectomized rats fed the same diet. Furthermore, hepatocellular ballooning was observed only in the OVX-HFSD rats. Similarly, HFSD-fed rats showed increased expressions of the inflammatory markers and M1 macrophage infiltration in the liver; however, only IL-6 expression was magnified in the OVX-HFSD.
Conclusion: Our data suggest that some of the structural changes and inflammatory response in the kidney and liver of rats fed a HFSD are exacerbated by ovariectomy.

Matched MeSH terms: Blood Pressure
Fulltext Comparison of high-fat style diet-induced dysregulation of baroreflex control of renal sympathetic nerve activity in intact and ovariectomized female rats: Renal sympathetic nerve activity in high-fat style diet fed intact and ovariectomized female rats

Sucedaram Y, Johns EJ, Husain R, Sattar MA, Abdulla M, Khalilpourfarshbafi M, et al.

Exp Biol Med (Maywood), 2020 05;245(9):761-776.
PMID: 32212858 DOI: 10.1177/1535370220915673

IMPACT STATEMENT: Over activation of renal sensory nerve in obesity blunts the normal regulation of renal sympathetic nerve activity. To date, there is no investigation that has been carried out on baroreflex regulation of renal sympathetic nerve activity in obese ovarian hormones deprived rat model, and the effect of renal denervation on the baroreflex regulation of renal sympathetic nerve activity. Thus, we investigated the role of renal innervation on baroreflex regulation of renal sympathetic nerve activity in obese intact and ovariectomized female rats. Our data demonstrated that in obese states, the impaired baroreflex control is indistinguishable between ovarian hormones deprived and non-deprived states. This study will be of substantial interest to researchers working on the impact of diet-induced hypertension in pre- and postmenopausal women. This study provides insight into health risks amongst obese women regardless of their ovarian hormonal status and may be integrated in preventive health strategies.

Matched MeSH terms: Blood Pressure
Obesity can predict and promote systemic inflammation in healthy adults

Ellulu MS, Khaza'ai H, Rahmat A, Patimah I, Abed Y

Int J Cardiol, 2016 Jul 15;215:318-24.
PMID: 27128554 DOI: 10.1016/j.ijcard.2016.04.089

BACKGROUND: To find out the differences on biomedical data between obese and non-obese participants, and to identify risk factors associated with systemic inflammation in healthy Palestinian adults.
METHODOLOGY: A cross-sectional study involved 105 apparently healthy adults. Interview questionnaire was used to collect personal information. Participants were excluded if they suffered from acute or chronic inflammatory diseases, or continued using medicines, which might affect the biomedical results.
RESULTS: In association with increased Body Mass Index (BMI), the obese group displayed significant higher markers including: interleukin 6 (IL-6), high sensitivity C reactive protein (hs-CRP), total cholesterol (TC), systolic blood pressure (SBP), and diastolic blood pressure (DBP). Obese group in association with increased waist circumference (WC) was higher significantly in inflammatory markers (IL-6, hs-CRP), lipid profile (TC) and triglyceride (TG), and blood pressure (SBP, DBP). A tertile of a feature of systemic inflammation (hs-CRP) was created, by Ordinal Logistic Regression, after adjusting for the age, gender, smoking habits, physical activity pattern, father and mother's health history; risk factors were the increased BMI [OR: 1.24] (95% CI: 1.005-1.548, P=0.050), IL-6 [OR: 3.35] (95% CI: 1.341-8.398, P=0.010), DBP [OR: 1.19] (95% CI: 1.034-1.367, P=0.015), and reduced Adiponectin [OR: 0.59] (95% CI: 0.435-0.820, P=0.001). Finally, BMI correlated with IL-6 and hs-CRP (r=0.326, P=0.005; r=0.347, P<0.001; respectively), and hs-CRP correlated with IL-6 (r=0.303, P=0.010), and inversely with Adiponectin (r=-0.342, P=0.001).
CONCLUSION: The increased level of IL-6 and reduced Adiponectin, which strongly associated with obesity, indicated that having high BMI is a useful marker in association with IL-6 and further developed systemic inflammation.

Matched MeSH terms: Blood Pressure
A study evaluating prevalence of hypertension and risk factors affecting on blood pressure control among type 2 diabetes patients attending teaching hospital in Malaysia

Abougalambou SS, Abougalambou AS

Diabetes Metab Syndr, 2013 Apr-Jun;7(2):83-6.
PMID: 23680246 DOI: 10.1016/j.dsx.2013.02.019

INTRODUCTION: Hypertension is extremely common disease found in patients with diabetes mellitus. Eighty to 90% of patients with type 2 diabetes mellitus will develop hypertension, and about 20% of hypertensive patients develop diabetes. The aim of this study was designed to assess the prevalence of hypertension and factors affecting the control of hypertension among type 2 diabetic patients.
MATERIALS AND METHODS: A total of 1077 type 2 diabetes mellitus patients were included in this study who attended at diabetes clinic of Universiti Sains Malaysia (USM) teaching hospital in Kelantan. All these patients were prospectively followed from January to December 2008. Logistic regression analysis was used to assess the independent effect of variables on hypertension.
RESULTS: The prevalence of hypertension (BP>130/80 or on medication for high blood pressure) was 92.7%. A total 471 (47.2%) patients had achieved blood pressure targets ≤ 130/80 mmHg. The logistic regression indicated that hypertension was positively associated with age (P=0.040), BMI (P=0.027), HbA1c (P=0.046), and level of education (P=0.039).
CONCLUSION: Hypertension is a common co-morbidity among diabetic patients. Hypertension was not controlled to the recommended levels of blood pressure in about one-half (52.8%) of diabetes patients. Age, BMI, HbA1c and level of education are factors affecting on hypertension.

Matched MeSH terms: Blood Pressure/physiology*; Blood Pressure Determination/methods; Blood Pressure Determination/standards*
Chromatographic comparison of atenolol separation in reaction media on cellulose tris-(3,5-dimethylphenylcarbamate) chiral stationary phase using ultra fast liquid chromatography

Agustian J, Kamaruddin AH, Aboul-Enein HY

Chirality, 2012 May;24(5):356-67.
PMID: 22517322 DOI: 10.1002/chir.22019

Because chiral liquid chromatography (LC) could become a powerful tool to estimate racemic atenolol quantity, excellent enantiomeric separation should be produced during data acquisition for satisfactory observation of atenolol concentrations throughout the racemic resolution processes. Selection of chiral LC column and analytical protocol that fulfill demands of the ultra fast LC analysis is essential. This article describes the characteristics of atenolol chromatographic separation that resulted from different resolution media and analytical protocols with the use of a Chiralcel® OD column. The chromatograms showed quite different characteristics of the separation process. The single enantiomer and racemic atenolol could be recognized by the Chiralcel® OD column in less than 20 min. Symmetrical peaks were obtained; however, several protocols produced peaks with wide bases and slanted baselines. Observations showed that efficient enantioresolution of racemic atenolol was obtained at slow mobile phase flow rate, decreased concentration of amine-type modifier but increased alcohol content in mobile phase and highest ultraviolet detection wavelength were required. The optimal ultra fast LC protocol enables to reduce and eliminate the peaks of either the atenolol solvent or the buffers and provided the highest peak intensities of both atenolol enantiomers.

Matched MeSH terms: Chromatography, High Pressure Liquid/methods
Application of continual injection liquid-phase microextraction method coupled with liquid chromatography to the analysis of organophosphorus pesticides

Raharjo Y, Sanagi MM, Ibrahim WA, Naim AA, Aboul-Enein HY

J Sep Sci, 2009 Feb;32(4):623-9.
PMID: 19165835 DOI: 10.1002/jssc.200800566

A liquid-phase microextraction coupled with LC method has been developed for the determination of organophosphorus pesticides (methidation, quinalphos and profenofos) in drinking water samples. In this method, a small amount (3 microL) of isooctane as the acceptor phase was introduced continually to fill-up the channel of a 1.5 cm polypropylene hollow fiber using a microsyringe while the hollow fiber was immersed in an aqueous donor solution. A portion of the acceptor phase (ca. 0.4 microL) was first introduced into the hollow fiber and additional amounts (ca. 0.2 microL) of the acceptor phase were introduced to replenish at intervals of 3 min until set end of extraction (40 min). After extraction, the acceptor phase was withdrawn and transferred into a 2 mL vial for a drying step prior to injection into a LC system. Parameters that affect the extraction efficiency were studied including the organic solvent, length of fiber, volume of acceptor and donor phase, stirring rate, extraction time, and effect of salting out. The proposed method provided good enrichment factors of up to 189.50, with RSD ranging from 0.10 to 0.29%, analyte recoveries of over 79.80% and good linearity ranging from 10.0 to 1.25 mg/L. The LOD ranged from 2.86 to 82.66 microg/L. This method was applied successfully to the determination of organophosphorus pesticides in selected drinking water samples.

Matched MeSH terms: Chromatography, High Pressure Liquid/instrumentation*; Chromatography, High Pressure Liquid/methods*
Determining weight-bearing tissue condition using peak reactive hyperemia response trend and ultrasonographic features: Implications for pressure ulcer prevention

Yapp JH, Raja Ahmad RMK, Mahmud R, Mohtarrudin N, Mohamad Yusof L, Abdul Rahim E, et al.

Wound Repair Regen, 2019 05;27(3):225-234.
PMID: 30667138 DOI: 10.1111/wrr.12698

Frequent repositioning is important to prevent pressure ulcer (PU) development, by relieving pressure and recovering damages on skin areas induced by repetitive loading. Although repositioning is the gold standard to prevent PU, there is currently no strategy for determining tissue condition under preventive approaches. In this study, the peak reactive hyperemia (RH) trends and ultrasonographic (US) features are compared with the tissue condition under histopathological examination to determine the potential use of these features in determining the tissue condition noninvasively. Twenty-one male Sprague-Dawley rats (seven per group), with body weight of 385-485 g, were categorized into three groups and subjected to different recovery times, each with three repetitive loading cycles at skin tissues above of right trochanter area. The first, second, and third groups were subjected to short (3 minutes), moderate (10 minutes), and prolonged (40 minutes) recovery, respectively, while applying fixed loading time and pressure (10 minutes and 50 mmHg, respectively), to provide different degree of recovery and tissue conditions (tissue damage and tissue recovery). Peak RH was measured in the three cycles to determine RH trend (increasing, decreasing, and inconsistent). All rat tissues were evaluated using ultrasound at pre- and post-experiment and rated by two raters to categorize the severity of tissue changes (no, mild, moderate, and severe). The tissue condition was also evaluated using histopathological examination to distinguish between normal and abnormal tissues. Most of the samples with increasing RH trend is related to abnormal tissue (71%); while inconsistent RH trends is more related to normal tissue (82%). There is no relationship between the tissue conditions evaluated under ultrasonographic and histopathological examination. Peak RH trend over repetitive loading may serve as a new feature for determining the tissue condition that leading to pressure ulcer.

Matched MeSH terms: Pressure Ulcer/pathology; Pressure Ulcer/prevention & control*
Association of insertion/deletion polymorphism of angiotensin-converting enzyme gene among Malay male hypertensive subjects in response to ACE inhibitors

Heidari F, Vasudevan R, Mohd Ali SZ, Ismail P, Etemad A, Pishva SR, et al.

J Renin Angiotensin Aldosterone Syst, 2015 Dec;16(4):872-9.
PMID: 25002132 DOI: 10.1177/1470320314538878

Several studies show that the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene has been associated with hypertension in various populations. The present study sought to determine the association of the I/D gene polymorphism among Malay male essential hypertensive subjects in response to ACE inhibitors (enalapril and lisinopril).

Matched MeSH terms: Blood Pressure

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