MyMedR

Displaying publications 1 - 20 of 134 in total

Abstract:

Sort:

Simple blood-spot sampling with nested polymerase chain reaction detection for epidemiology studies on Brugia malayi

Cox-Singh J, Pomrehn AS, Rahman HA, Zakaria R, Miller AO, Singh B

Int J Parasitol, 1999 May;29(5):717-21.
PMID: 10404266

In the absence of a suitable Brugia malayi antigen detection assay, PCR remains one of the more sensitive alternatives to Giemsa-stained thick blood films for B. malayi detection. The need for refrigerated storage and transportation of blood has limited the use of PCR for large-scale epidemiology studies in remote endemic areas. Here we report simple finger-prick blood-spot collection, a one-tube DNA template extraction method and the development of a B. malayi-specific nested PCR assay. The assay was tested on 145 field samples and was positive for all 30 microscopy-positive samples and for an additional 13 samples which were microscopy-negative.
Cyproterone acetate and reversal of the impaired endometrial decidualization in streptozotocin-diabetic pseudopregnant rats

Zakaria R, Ismail Z, Chatterjee A

Pharmacol Res, 2000 Aug;42(2):183-6.
PMID: 10887050

Reproductive dysfunction in the female diabetic rat is associated with impaired hypothalamic-hypophyseal system, anovulation, insufficiency of ovarian steroidogenesis and spontaneous failure of pregnancy. Formation of decidua, the highly modified endometrium of pregnancy and pseudopregnancy could only be achieved when the uterus was sensitized by a sequence of oestrogen and progesterone. In this study, we examined whether the impaired expression of endometrial decidualization in the pseudopregnant rat is linked with diabetes-associated hypersecretion of testosterone. Rats were made pseudopregnant by sterile mating. Diabetes was induced by streptozotocin on day 1 p.c. Deciduogenic stimulus was given on day 5 p.c. Treatment of cyproterone acetate (10 mg kg(-1)) was scheduled from day 5 through day 9 p.c. Animals were killed on day 10 p.c, and the degree of endometrial decidual growth, plasma levels of oestradiol, progesterone, ACTH and testosterone were determined. Results showed that compared to controls there was a concomitant drop in endometrial decidual growth concurrently with impaired levels of oestradiol and progesterone in diabetic pseudopregnant rats. ACTH and testosterone levels were, however, profoundly elevated. Cyproterone acetate treatment in the diabetic pseudopregnant rat resulted in a simultaneous elevation of oestradiol and progesterone, which eventually helped the endometrial differentiation to decidua in the diabetic pseudopregnant rat parallel to controls. Present experimental data suggest that diabetes-associated impaired endometrial decidualization in the pseudopregnant rat is possibly caused by testosterone-induced oestrogen deficiency.
Short report: differences in dihydrofolate reductase but not dihydropteroate synthase alleles in Plasmodium falciparum isolates from geographically distinct areas in Malaysia

Cox-Singh J, Zakaria R, Abdullah MS, Rahman HA, Nagappan S, Singh B

Am J Trop Med Hyg, 2001 6 27;64(1-2):28-31.
PMID: 11425158

Dihydropteroate synthase (dhps) and dihydrofolate reductase (dhfr) alleles were typed in 67 Malaysian Plasmodium falciparum isolates. The isolates were collected from two geographically distinct locations: 51 from Sabah, Malaysian Borneo, where sulfadoxine/pyrimethamine (SDX/PYR) is used to treat uncomplicated malaria and 16 from Peninsular Malaysia where in vivo resistance to SDX/PYR has been reported. A total of seven dhps alleles were identified with no significant difference in allele frequency between the 2 populations. Two of the dhps alleles described here have not been previously reported. Four dhfr alleles were detected in 67 P. falciparum isolates. Eighty-seven percent of the isolates from the Peninsula, where clinical SDX/PYR failure has been reported, had dhfr alleles with triple point mutations while all of the isolates from Sabah had dhfr alleles with 2 or less point mutations. The difference in dhfr allele frequency between the two populations was highly significant. There was no correlation between in vitro PYR response and accumulation of dhfr point mutations.
Diabetes alters the mRNA expression of insulin-like growth factors and their receptors in the mouse fallopian tube and uterus during the preimplantation stages

Zakaria R, Rajikin MH, Yaacob NS, Nor NM

Reprod Biol, 2007 Mar;7(1):41-53.
PMID: 17435832

The possible role of insulin-like growth factors (IGFs) and their receptors (IGFRs) in the pathogenesis of diabetic embryopathy was investigated. Sexually mature female ICR mice of 6-8 weeks old were made diabetic by a single intraperitoneal injection with 200 mg/kg streptozotocin ten days prior to mating. Fallopian tubes and uterine tissues were obtained from the superovulated diabetic and normal mice 48, 72 and 96 hours following human chorionic gonadotropin (hCG) injection. The mRNA expression of IGF-1 and IGF-2 as well as their receptors was determined in the tissues using Real-time Polymerase Chain Reaction (Real-time PCR). The mRNA expression of IGF-1 in the fallopian tube and uterus of the diabetic mice was significantly lower 72 and 96 hours after hCG treatment, respectively, as compared to the controls. The mRNA expression of IGF-1R at 96 hours post-hCG treatment was significantly higher in the fallopian tube and lower in the uterus of the diabetic mice as compared to the controls. The mRNA expression IGF-2 in the fallopian tube was significantly higher 48 and 96 hours after hCG treatment, but was lower in the uterus of diabetic mice 96 hours after hCG treatment as compared to controls. The mRNA expression of IGF-2R in the diabetic mice was significantly higher 48 and 96 hours (the fallopian tube) and 48 hours (uterus) after hCG treatments as compared to the controls. In conclusion, an alteration in mRNA expression of IGFs and their receptors in the diabetic mice as observed in this study could possibly result in diabetic embryopathy.
Fulltext Superselective embolisation in acute lower gastrointestinal haemorrhage: a single institution experience

Md Ralib AR, Zakaria R, Mohamad Z, Muda AS

Malays J Med Sci, 2009 Oct;16(4):34-41.
PMID: 22135510 MyJurnal

Superselective embolisation has been recognised as integral in the management of lower gastrointestinal haemorrhage. It has also reduced the need for emergency surgery. The objective of this case series was to describe the lower gastrointestinal haemorrhage cases seen in our centre, its diagnosis and the role of superselective embolisation in patient management.
Immunolocalization of insulin-like growth factors and their receptors in the diabetic mouse oviduct and uterine tissues during the preimplantation period

Zakaria R, Rajikin MH, Yaacob NS, Nor NM

Acta Histochem, 2009;111(1):52-60.
PMID: 18676006 DOI: 10.1016/j.acthis.2008.04.002

The aim of the present study was to analyze the immunolocalization of insulin-like growth factor (IGF)-1 and IGF-2 and their receptors in the oviduct and uterus of control and diabetic mice. Sexually mature female ICR mice aged 6-8 weeks were rendered diabetic by streptozotocin (200 mg/kg, administered intraperitoneally). Oviductal and uterine tissues were obtained from the superovulated control and diabetic mice at 48, 72 and 96 h post-human chorionic gonadotropin (hCG) treatment. Localization of IGF-1, IGF-2, IGF-1R and IGF-2R was determined by immunohistochemistry and a semi-quantitative scoring of immunolabelling was performed using a standardized 5-point system. The immunohistochemical scorings for both IGF-1 and IGF-1R were significantly decreased in the oviducts of diabetic mice at 96 h post-hCG treatment. The scores for IGF-2 were significantly increased in the oviducts of diabetic mice at 48 and 72 h post-hCG treatment, and for IGF-2R at 72 h post-hCG treatment. However, there was no significant difference in the scores of IGFs and their receptors in the uterus of control and diabetic mice. In conclusion, the oviductal immunolabelling for IGFs and their receptors was significantly altered by maternal diabetes, which may be of importance in the pathogenesis of preimplantation diabetic embryopathy.
Exogenous leptin administration decreases sperm count and increases the fraction of abnormal sperm in adult rats

Haron MN, D'Souza UJ, Jaafar H, Zakaria R, Singh HJ

Fertil. Steril., 2010 Jan;93(1):322-4.
PMID: 19709655 DOI: 10.1016/j.fertnstert.2009.07.995

Daily intraperitoneal injection of 5-30 microg/kg body weight of leptin for 42 days to adult rats decreases sperm count and increases the fraction of abnormal sperm.
Effects of antenatal, postpartum and post-weaning melatonin supplementation on blood pressure and renal antioxidant enzyme activities in spontaneously hypertensive rats

Lee SK, Sirajudeen KN, Sundaram A, Zakaria R, Singh HJ

J Physiol Biochem, 2011 Jun;67(2):249-57.
PMID: 21210316 DOI: 10.1007/s13105-010-0070-2

Although melatonin lowers blood pressure in spontaneously hypertensive rats (SHR), its effect following antenatal and postpartum supplementation on the subsequent development of hypertension in SHR pups remains unknown. To investigate this, SHR dams were given melatonin in drinking water (10 mg/kg body weight/day) from day 1 of pregnancy until day 21 postpartum. After weaning, a group of male pups continued to receive melatonin till the age of 16 weeks (Mel-SHR), while no further melatonin was given to another group of male pups (Maternal-Mel-SHR). Controls received plain drinking water. Systolic blood pressure (SBP) was measured at 4, 6, 8, 12 and 16 weeks of age, after which the kidneys were collected for analysis of antioxidant enzyme profiles. SBP was significantly lower till the age of 8 weeks in Maternal-Mel-SHR and Mel-SHR than that in the controls, after which no significant difference was evident in SBP between the controls and Maternal-Mel-SHR. SBP in Mel-SHR was lower than that in controls and Maternal-Mel-SHR at 12 and 16 weeks of age. Renal glutathione peroxidase (GPx) and glutathione s-transferase (GST) activities, levels of total glutathione and relative GPx-1 protein were significantly higher in Mel-SHR. GPx protein was however significantly higher in Mel-SHR. No significant differences were evident between the three groups in the activities of superoxide dismutase, catalase and glutathione reductase. In conclusion, it appears that while antenatal and postpartum melatonin supplementation decreases the rate of rise in blood pressure in SHR offspring, it however does not alter the tendency of offspring of SHR to develop hypertension.
Fulltext Soils on exposed Sunda shelf shaped biogeographic patterns in the equatorial forests of Southeast Asia

Slik JW, Aiba S, Bastian M, Brearley FQ, Cannon CH, Eichhorn KA, et al.

Proc Natl Acad Sci U S A, 2011 Jul 26;108(30):12343-7.
PMID: 21746913 DOI: 10.1073/pnas.1103353108

The marked biogeographic difference between western (Malay Peninsula and Sumatra) and eastern (Borneo) Sundaland is surprising given the long time that these areas have formed a single landmass. A dispersal barrier in the form of a dry savanna corridor during glacial maxima has been proposed to explain this disparity. However, the short duration of these dry savanna conditions make it an unlikely sole cause for the biogeographic pattern. An additional explanation might be related to the coarse sandy soils of central Sundaland. To test these two nonexclusive hypotheses, we performed a floristic cluster analysis based on 111 tree inventories from Peninsular Malaysia, Sumatra, and Borneo. We then identified the indicator genera for clusters that crossed the central Sundaland biogeographic boundary and those that did not cross and tested whether drought and coarse-soil tolerance of the indicator genera differed between them. We found 11 terminal floristic clusters, 10 occurring in Borneo, 5 in Sumatra, and 3 in Peninsular Malaysia. Indicator taxa of clusters that occurred across Sundaland had significantly higher coarse-soil tolerance than did those from clusters that occurred east or west of central Sundaland. For drought tolerance, no such pattern was detected. These results strongly suggest that exposed sandy sea-bed soils acted as a dispersal barrier in central Sundaland. However, we could not confirm the presence of a savanna corridor. This finding makes it clear that proposed biogeographic explanations for plant and animal distributions within Sundaland, including possible migration routes for early humans, need to be reevaluated.
Note: Fabrication of tapered fibre tip using mechanical polishing method

Cheong YK, Lim KS, Lim WH, Chong WY, Zakaria R, Ahmad H

Rev Sci Instrum, 2011 Aug;82(8):086115.
PMID: 21895293 DOI: 10.1063/1.3627374

Tapered fibre tips fabricated using mechanical polishing method is studied. The fibre tips are formed by sequential polishing flat-ended single mode fibres with decreasing aluminium oxide polishing film grit size. Based on the proposed technique, tapered fibre tips with cone angle ranging from 30° to 130° are fabricated by controlling the polishing angle. Besides the variety of cone angle, considerable smoothness of the fibre tip surface may assist in good metal coating and hence a well-defined aperture can be obtained. In addition, this paper presents a two-step hybrid fabrication method combining the proposed polishing method with chemical etching method to increase the possible fibre tip cone angles achievable by chemical etching method.
Fulltext The vanishing veins: difficult venous access in a patient requiring translumbar, transhepatic, and transcollateral central catheter insertion

Yaacob Y, Zakaria R, Mohammad Z, Ralib AR, Muda AS

Malays J Med Sci, 2011 Oct;18(4):98-102.
PMID: 22589680

Central venous catheter placement is indicated in patients requiring long-term therapy. With repeated venous catheterisations, conventional venous access sites can be exhausted. This case illustrates the expanding role of radiology in managing difficult venous access. We present a case of translumbar, transhepatic, and transcollateral placement of central catheter in a woman with a difficult venous access problem who required lifelong parenteral nutrition secondary to short bowel syndrome. This case highlights the technical aspects of interventional radiology in vascular access management.
Fulltext Y-stent-assisted coil embolisation of wide-necked aneurysms using a new fully retrievable and detachable intracranial stent: report of two cases

Muda AS, Ralib AR, Yaacob Y, Zakaria R, Bakar AA

Malays J Med Sci, 2011 Oct;18(4):91-7.
PMID: 22589679

Endovascular treatment of wide-necked aneurysms poses a challenge for the endovascular therapist. The Y-stent-assisted technique has been used for stent-assisted coil embolisation for wide-necked bifurcation aneurysms. This technique has been described for basilar tip aneurysms and middle cerebral artery bifurcation aneurysms using Neuroform and Enterprise stents. We report 2 cases of wide-necked bifurcation aneurysms that were treated with Y-stent-assisted coil embolisation using a new, fully retrievable and detachable intracranial stent (Solitaire AB™). We describe the advantages of a fully retrievable and detachable stent and its feasibility of forming a Y configuration.
Improvement in immediate memory after 16 weeks of tualang honey (Agro Mas) supplement in healthy postmenopausal women

Othman Z, Shafin N, Zakaria R, Hussain NH, Mohammad WM

Menopause, 2011 Nov;18(11):1219-24.
PMID: 21926932 DOI: 10.1097/gme.0b013e31821e2044

The aim of this study was to evaluate the verbal learning and memory performance of postmenopausal women who received tualang honey (Agro Mas) in comparison with women receiving estrogen plus progestin therapy and untreated controls.
Sensitivity and specificity of visual clinical assessment as compared to WHO 2006 standard and NCHS 1977 reference in measuring the growth status of Malaysian infants

Selamat R, Zain F, Raib J, Zakaria R, Marzuki MS, Ibrahim TF

J Am Coll Nutr, 2011 Dec;30(6):522-8.
PMID: 22331687

OBJECTIVE: To study the validity of the visual clinical assessment of weight relative to length and length relative to age as compared to the World Health Organization (WHO) 2006 standard and National Center for Health Statistics (NCHS) 1977 reference in asssessing the physical growth of children younger than 1 year.
MATERIALS AND METHODS: A prospective cohort study was carried out among 684 infants attending goverment health clinics in 2 states in Malaysia. Body weight, length, and clinical assessment were measured on the same day for 9 visits, scheduled every month until 6 months of age and every 2 months until 12 months of age. All of the 3 z-scores for weight for age (WAZ), length for age (HAZ), and weight for length (WHZ) were calculated using WHO Anthro for Personal Computers software.
RESULTS: The average sensitivity and specificity for the visual clinical assessment for the detection of thinness were higher using the WHO 2006 standard as compared with using NCHS 1977. However, the overall sensitivity of the visual clinical assessment for the detection of thin and lean children was lower from 1 month of age until a year as compared with the WHO 2006 standard and NCHS 1977 reference. The positive predictive value (PPV) for the visual clinical assessment versus the WHO 2006 standard was almost doubled as compared with the PPV of visual clinical assessment versus the NCHS 1977 reference. The overall average sensitivity, specificity, PPV, and negative predictive value for the detection of stunting was higher for visual clinical assessment versus the WHO 2006 standard as compared with visual clinical assessment versus the NCHS 1977 reference.
CONCLUSION: The sensitivity and specificity of visual clinical assessment for the detection of wasting and stunting among infants are better for the WHO 2006 standard than the NCHS 1977 reference.
Effect of cross-fostering on renal anti-oxidant/oxidant status and development of hypertension in spontaneously hypertensive rats

Lee SK, Sirajudeen KN, Sundaram A, Zakaria R, Singh HJ

Clin Exp Pharmacol Physiol, 2011 Dec;38(12):854-9.
PMID: 21973174 DOI: 10.1111/j.1440-1681.2011.05624.x

1. The hypotensive effect of cross-fostering in spontaneously hypertensive rats (SHR) is thought to involve adjustments in renal function. However, its association with renal anti-oxidant/oxidant balance during cross-fostering is not known. 2. The present study examined the effect of cross-fostering and in-fostering of 1-day-old offspring between SHR and Wistar-Kyoto (WKY) dams on renal anti-oxidant/oxidant status and systolic blood pressure (SBP). Renal anti-oxidant/oxidant status and SBP were determined in the offspring from 4-16 weeks of age. 3. Cross-fostered SHR had significantly lower SBP than in-fostered SHR at 6, 8 and 12 weeks, but not at 16 weeks (127 ± 1 vs 144 ± 2, 138 ± 1 vs 160 ± 1, 174 ± 2 vs 184 ± 2 and 199 ± 2 vs 194 ± 3 mmHg at 6, 8, 12 and 16 weeks, respectively). No differences in SBP were evident between cross-fostered and in-fostered WKY rats. There were no significant differences in levels of thiobarbituric acid-reactive substances (TBARS), protein carbonyl and total anti-oxidant status (TAS) or superoxide dismutase, catalase, glutathione peroxidase (GPx), glutathione S-transferase and glutathione reductase activity between cross-fostered and in-fostered SHR or WKY offspring. However, compared with WKY rats, catalase activity was higher at 6 and 16 weeks, TAS was higher at 16 weeks and GPx activity and TBARS were lower at 16 weeks in SHR. 4. It appears that cross-fostering of SHR offspring to WKY dams during the early postnatal period causes a transient delay in the rise in blood pressure in SHR and that this does not involve the renal anti-oxidant/oxidant system.
Arterial stiffness, inflammatory and pro-atherogenic markers in gestational diabetes mellitus

Salmi AA, Zaki NM, Zakaria R, Nor Aliza AG, Rasool AH

VASA, 2012 Mar;41(2):96-104.
PMID: 22403127 DOI: 10.1024/0301-1526/a000171

This study aims to determine whether gestational diabetes mellitus (GDM) is associated with increased arterial stiffness, inflammatory and pro-atherogenic markers compared to age matched controls.
Fulltext Fatal mediastinal biopsy: How interventional radiology saves the day

Yaacob Y, Muda S, Zakaria R

Ann Thorac Med, 2012 Apr;7(2):107-9.
PMID: 22558017 DOI: 10.4103/1817-1737.94534

This was a case of a 35-year-old man with mediastinal mass requiring computed tomography (CT)-guided biopsy for tissue diagnosis. A posterior approach with an 18-gauge biopsy needle was used to obtain tissue sample. Post biopsy, patient condition deteriorated and multiphase CT study detected active bleeding in arterial phase at the biopsy site with massive hemothorax. Subsequent angiography showed arterial bleeder arising from the apical branch of the right pulmonary artery. Selective endovascular embolization with NBCA (n-Butyl cyanoacrylate) was successful. Patient survived the complication. The case highlighted a rare complication in a common radiology procedure and the value of the interventional radiology unit in avoiding a fatal outcome.
Melatonin effects on Plasmodium life cycle: new avenues for therapeutic approach

Srinivasan V, Ahmad AH, Mohamed M, Zakaria R

Recent Pat Endocr Metab Immune Drug Discov, 2012 May;6(2):139-47.
PMID: 22537380

Malaria remains a global health problem affecting more than 515 million people all over the world including Malaysia. It is on the rise, even within unknown regions that previous to this were free of malaria. Although malaria eradication programs carried out by vector control programs are still effective, anti-malarial drugs are also used extensively for curtailing this disease. But resistance to the use of anti-malarial drugs is also increasing on a daily basis. With an increased understanding of mechanisms that cause growth, differentiation and development of malarial parasites in rodents and humans, new avenues of therapeutic approaches for controlling the growth, synchronization and development of malarial parasites are essential. Within this context, the recent discoveries related to IP3 interconnected signalling pathways, the release of Ca2+ from intracellular stores of Plasmodium, ubiquitin protease systems as a signalling pathway, and melatonin influencing the growth and differentiation of malarial parasites by its effects on these signalling pathways have opened new therapeutic avenues for arresting the growth and differentiation of malarial parasites. Indeed, the use of melatonin antagonist, luzindole, has inhibited the melatonin's effect on these signalling pathways and thereby has effectively reduced the growth and differentiation of malarial parasites. As Plasmodium has effective sensors which detect the nocturnal plasma melatonin concentrations, suppression of plasma melatonin levels with the use of bright light during the night or by anti-melatonergic drugs and by using anti-kinase drugs will help in eradicating malaria on a global level. A number of patients have been admitted with regards to the control and management of malarial growth. Patents related to the discovery of serpentine receptors on Plasmodium, essential for modulating intra parasitic melatonin levels, procedures for effective delivery of bright light to suppress plasma melatonin levels and thereby arresting the growth and elimination of malarial parasites from the blood of the host are all cited in the paper. The purpose of the paper is to highlight the importance of melatonin acting as a cue for Plasmodium faciparum growth and to discuss the ways of curbing the effects of melatonin on Plasmodium growth and for arresting its life cycle, as a method of eliminating the parasite from the host.
Fulltext The distribution of anacardiaceae in teluk bahang forest reserve, pulau pinang

Juperi S, Zakaria R, Mansor A

Trop Life Sci Res, 2012 May;23(1):35-44.
PMID: 24575224 MyJurnal

To investigate the distribution of Anacardiaceae in Teluk Bahang Permanent Forest Reserve (TBPFR) in Pulau Pinang, all trees with a diameter at breast high (DBH) ≥ 5 cm were enumerated in a study site constituting 0.4 ha of the reserve. Seventy five individuals of Anacardiaceae (14% of all trees) are recorded. These individuals represent 4 genera and 5 species, namely, Mangifera pentandra, Mangifera macrocarpa, Gluta elegans, Campnosperma auriculatum and Swintonia floribunda. The mean density of Anacardiaceae within the study plots is 7.50±8.14 (mean±S.D.) per ha whereas the basal area (BA) calculated is 0.97 m(2)/0.40 ha. The importance value (IVi) for Anacardiaceae is 81%. The estimated total aboveground biomass (TAGB) for Anacardiaceae is 24.24 ton/0.40 ha. A total of 333 Anacardiaceae saplings with a DBH < 5 cm are recorded. These saplings have been identified as juveniles of the genera Gluta (9.99%), Swintonia (84.90%) and Mangifera (5.11%).
Malaria, anti malarial drugs and the role of melatonin

Srinivasan V, Mohamed M, Zakaria R, Ahmad AH

Infect Disord Drug Targets, 2012 Oct;12(5):371-9.
PMID: 23082960

Malaria, one of the most deadly diseases of our time affects more than 200 million people across the globe and is responsible for about one million deaths annually. Until recently Plasmodium falciparum has been the main cause for malarial infection in human beings but now Plasmodium knowlesi from Malaysia remains as one of the most virulent parasite spreading fast not only in Malaysia but in different parts of the world. Hence there is urgent need for the global fight to control malaria. Global malaria eradication program by use of insecticide spraying has resulted in good response in the past. Treatment of malaria infected patients with anti-malarial drugs has helped to eliminate malarial infections successfully but with increased resistance displayed by malarial parasites to these drugs there is resurgence of malaria caused both by drug resistance as well as by infection caused by new malarial species like Plasmodium knowlesi. With recent advances on molecular studies on malarial parasites it is now clear that the pineal hormone melatonin acts as a cue for growth and development of Plasmodium falciparum. Same may be true for Plasmodium knowlesi also. Hence treatment modalities that can effectively block the action of melatonin on Plasmodium species during night time by way of using either bright light therapy or use of melatonin receptor blocking can be considered as useful approaches for eliminating malarial infection in man.

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links