MyMedR

Hypersensitivity reaction to dapsone: report from Malaysia

Mohamed KN

Lepr Rev, 1984 Dec;55(4):385-9.

Mohamed KN

Ann Trop Paediatr, 1988 Dec;8(4):222-4.

Yaws was detected in a six-member family in the southern Malaysia state of Johor. This stresses the need to be vigilant against a long-forgotten disease of childhood which was of great public health concern in the past.

Late yaws and optic atrophy

Mohamed KN

Ann Trop Med Parasitol, 1990 Dec;84(6):637-9.

PMID: 2076042

Verrucous lesions in children in the tropics

Mohamed KN

Ann Trop Paediatr, 1990;10(3):273-7.

PMID: 1703744

A wide variety of skin disorders in children are encountered by doctors practising in tropical countries. While some of them are common and pose little difficulty in their management, a few are uncommon, run a protracted course and cause errors in diagnosis. Two patients--one with cutaneous tuberculosis and the other with chromomycosis--are described and illustrate the importance of early and prompt detection of disease in children.

Fulltext Angioimmunoblastic lymphadenopathy--a fulminant case

Mohamed KN

Singapore Med J, 1991 Aug;32(4):276-8.

PMID: 1776012

A 60 year old male presented with pruritus, excoriations and enlargement of several groups of lymph nodes associated with constitutional symptoms following the intake of an aspirin preparation. Lymph node biopsy established the diagnosis of angioimmunoblastic lymphadenopathy. The need to be aware of this condition is highlighted when patients present with clinical features suspicious of lymphoma.

Occupational contact dermatitis from arsenic in a tin-smelting factory

Mohamed KB

Contact Derm., 1998 Apr;38(4):224-5.

PMID: 9565305

Fixed drug eruption associated with co-trimoxazole

Mohamed KB

J Pediatr, 1999 Sep;135(3):396.

PMID: 10484812

Myxozoan pathogens in cultured Malaysian fishes. II. Myxozoan infections of redtail catfish Hemibagrus nemurus in freshwater cage cultures

Molnár K, Székely C, Mohamed K, Shaharom-Harrison F

Dis Aquat Organ, 2006 Mar 2;68(3):219-26.

PMID: 16610587

Cage-cultured Asian redtail catfish Hemibagrus nemurus (Valenciennes, 1840), a popular food fish in Southeast Asia, proved to be infected by 3 myxozoan species. All the 3 species belonged to the genus Henneguya: 2 were identified as H. mystusia Sarkar, 1985 and H. hemibagri Tchang et Ma, 1993, while the other was described as H. basifilamentalis sp. n. All plasmodia were found in the gills and were characterised by a specific site selection. H. mystusia formed plasmodia in the multi-layered epithelium between the gill lamellae and in the non-lamellar edge of the gill filaments, while H. hemibagri developed in the capillary network of the lamellae. H. basifilamentalis sp. n. had large oval plasmodia located deep among the filaments just above the gill arch.

Myxozoan pathogens in cultured Malaysian fishes. I. Myxozoan infections of the sutchi catfish Pangasius hypophthalmus in freshwater cage cultures

Molnár K, Székely C, Mohamed K, Shaharom-Harrison F

Dis Aquat Organ, 2006 Mar 2;68(3):209-18.

PMID: 16610586

Cage-cultured sutchi catfish Pangasius hypophthalmus (Sauvage, 1878), a favourite food fish in Southeast Asia, proved to be infected by 6 myxozoan species. Three species belonged to the genus Hennegoides (H. berlandi, H. malayensis, and H. pangasii), 1 to Henneguya (H. shariffi) and 2 to Myxobolus (M. baskai, and M. pangasii). Five myxozoans infected the gills and 1 was found on the spleen. Myxozoans infecting the gills were characterised by a specific site selection. H. shariffi sp. n. and H. berlandi sp. n. formed plasmodia in the multi-layered epithelium of the gill filaments. Of the 2 vascular species H. pangasii sp. n. developed in the gill arteries, while M. baskai sp. n. infected the capillary network of the gill lamellae. Plasmodia of H. malayensis sp. n. were found inside the cartilaginous gill rays of the filaments. Large plasmodia of M. pangasii sp. n. were located in a groove of the spleen but they affected only the serosa layer covering the spleen.

Fulltext Myxozoan pathogens of Malaysian fishes cultured in ponds and net-cages

Székely C, Shaharom-Harrison F, Cech G, Mohamed K, Molnár K

Dis Aquat Organ, 2009 Jan 28;83(1):49-57.

PMID: 19301636 DOI: 10.3354/dao01990

We describe new myxosporean species from Malaysian fishes cultured in pond farms and net-cages. Myxobolus omari sp. nov. and M. leptobarbi sp. nov. were found in the muscles of Pangasianodon hypophthalmus and Leptobarbus hoevenii, respectively, while plasmodia and spores of Thelohanellus zahrahae sp. nov. and Henneguya daoudi sp. nov. were detected in the gills of Barbonymus gonionotus and Trichogaster trichopterus, respectively. Plasmodia and spores found in these fishes differed from the known myxosporean species in respect of their morphology, tissue tropism and 18S rDNA structure. No major pathological changes were found, but in the future these species might pose a potential threat to more intensified fish culture.

A packed bed membrane reactor for production of biodiesel using activated carbon supported catalyst

Baroutian S, Aroua MK, Raman AA, Sulaiman NM

Bioresour Technol, 2011 Jan;102(2):1095-102.

PMID: 20888219 DOI: 10.1016/j.biortech.2010.08.076

In this study, a novel continuous reactor has been developed to produce high quality methyl esters (biodiesel) from palm oil. A microporous TiO2/Al2O3 membrane was packed with potassium hydroxide catalyst supported on palm shell activated carbon. The central composite design (CCD) of response surface methodology (RSM) was employed to investigate the effects of reaction temperature, catalyst amount and cross flow circulation velocity on the production of biodiesel in the packed bed membrane reactor. The highest conversion of palm oil to biodiesel in the reactor was obtained at 70 °C employing 157.04 g catalyst per unit volume of the reactor and 0.21 cm/s cross flow circulation velocity. The physical and chemical properties of the produced biodiesel were determined and compared with the standard specifications. High quality palm oil biodiesel was produced by combination of heterogeneous alkali transesterification and separation processes in the packed bed membrane reactor.

Myxozoan infection of the Malaysian mahseer, Tor tambroides, of Tasik Kenyir Reservoir, Malaysia: description of a new species Myxobolus tambroides sp.n

Székely C, Shaharom F, Cech G, Mohamed K, Zin NA, Borkhanuddin MH, et al.

Parasitol Res, 2012 Oct;111(4):1749-56.

PMID: 22782473

Tor tambroides, a common and appreciated cyprinid fish of the Tasik Kenyir water reservoir in Malaysia, is one of the species selected for propagation. This fish was first successfully propagated in Malaysia by the Department of Agriculture, Sarawak, Malaysia, and the breeding program continued throughout the country. The gills were frequently infected by a Myxobolus species to be described as Myxobolus tambroides sp. n. The small, 50 to 70 μm, round plasmodia of this species is located intralamellarly. Plasmodia were filled with pyriform myxospores, 9.9 and 7.4 μm wide. In sutural view, the caudal end of the myxospores had a distinctive valvular groove, parallel with the suture. Plasmodia caused deformations on the affected and the neighbouring gill lamellae. The 18S rDNA sequence of M. tambroides sp.n. did not show a close relationship with any other Myxobolus spp., represented in the GenBank. This might be an emerging parasite likely to impact the propagation of this fish.

Fulltext Preparation and elastic moduli of germanate glass containing lead and bismuth

Sidek HA, Bahari HR, Halimah MK, Yunus WM

Int J Mol Sci, 2012;13(4):4632-41.

PMID: 22606000 DOI: 10.3390/ijms13044632

This paper reports the rapid melt quenching technique preparation for the new family of bismuth-lead germanate glass (BPG) systems in the form of (GeO(2))(60)-(PbO)(40-) (x)-(½Bi(2)O(3))(x) where x = 0 to 40 mol%. Their densities with respect of Bi(2)O(3) concentration were determined using Archimedes' method with acetone as a floatation medium. The current experimental data are compared with those of bismuth lead borate (B(2)O(3))(20)-(PbO)(80-) (x)-(Bi(2)O(3))(x). The elastic properties of BPG were studied using the ultrasonic pulse-echo technique where both longitudinal and transverse sound wave velocities have been measured in each glass samples at a frequency of 15 MHz and at room temperature. Experimental data shows that all the physical parameters of BPG including density and molar volume, both longitudinal and transverse velocities increase linearly with increasing of Bi(2)O(3) content in the germanate glass network. Their elastic moduli such as longitudinal, shear and Young's also increase linearly with addition of Bi(2)O(3) but the bulk modulus did not. The Poisson's ratio and fractal dimensionality are also found to vary linearly with the Bi(2)O(3) concentration.

Fulltext Infrared study of Er(3+)/Yb(3+) Co-Doped GeO(2)-PbO-Bi(2)O(3) glass

Bahari HR, Sidek HA, Adikan FR, Yunus WM, Halimah MK

Int J Mol Sci, 2012;13(7):8609-14.

PMID: 22942723 DOI: 10.3390/ijms13078609

Heavy metal oxide glasses, containing bismuth and/or lead in their glass structure are new alternatives for rare eart (RE) doped hosts. Hence, the study of the structure of these vitreous systems is of great interest for science and technology. In this research work, GeO(2)-PbO-Bi(2)O(3) glass host doped with Er(3+)/Yb(3+) ions was synthesized by a conventional melt quenching method. The Fourier transform infrared (FTIR) results showed that PbO and Bi(2)O(3) participate with PbO(4) tetragonal pyramids and strongly distort BiO(6) octahedral units in the glass network, which subsequently act as modifiers in glass structure. These results also confirmed the existence of both four and six coordination of germanium oxide in glass matrix.

Investigation of a nanofabrication process to achieve high aspect-ratio nanostructures on a quartz substrate

Mohamed K, Alkaisi MM

Nanotechnology, 2013 Jan 11;24(1):015302.

PMID: 23221357 DOI: 10.1088/0957-4484/24/1/015302

This work investigates the development of a nanofabrication process to achieve high aspect-ratio nanostructures on quartz substrates using electron beam lithography (EBL) patterning and fluorinated plasma etching processes. An imaging layer of a poly(methyl methacrylate) bi-layer resist was spun coated on quartz substrate and exposed by an e-beam with the designed patterns of sub-100 nm feature sizes using a Raith-150 EBL patterning tool. Additive pattern transfer was employed by depositing a 40 nm thick Nichrome layer on the resist pattern using a metal evaporator which was later lifted off by soaking in acetone. Nichrome was employed as an etch mask and an Oxford Plasmalab 80Plus reactive ion etcher was used for the etching process. The etching process was carried out in a gas mixture of CHF(3)/Ar with a flow rate ratio of 50/30 sccm, pressure of 20 mTorr, radiofrequency power of 200 W and at room temperature. These etching process parameters were found to achieve a 10 nm min(-1) etch rate and tall vertical side walls profile. An aspect-ratio of 10:1 was achieved on 60 nm feature size structures.

Antimutagenic effects of aqueous fraction of Myristica fragrans (Houtt.) leaves on Salmonella typhimurium and Mus musculus

Akinboro A, Bin Mohamed K, Asmawi MZ, Yekeen TA

Acta Biochim. Pol., 2014;61(4):779-85.

PMID: 25520963

Natural plant extracts offer a promising hope in the prevention/treatment of cancer arising from genetic mutations. This study evaluated in vitro and in vivo mutagenic and antimutagenic effects of aqueous fraction of Myristica fragrans (AFMF) leaves on TA100 strain of Salmonella typhimurium and Mus musculus (Male Swiss albino mice), respectively. The antioxidant activity of AFMF against 2,2-diphenyl-1-picrylhydrazyl (DPPH), total phenolic and flavonoid contents were determined, followed by its phytochemical elucidation using the Ultra Performance Liquid Chromatography technique (UPLC). The mutagenicity of AFMF at 4, 20, 50, 100, 200, 500, and 1000 µg/well was <2.0 in S. typhimurium and the induced micronucleated polychromatic and normochromatic erythrocytes at 500, 1000, 2000, and 4000 mg/kg were not significantly different from the negative control (p≥0.05). The mutagenic activity of benzo[a]pyrene and cyclophosphamide was significantly suppressed above 50.0% throughout the tested concentrations. Fifty percent of the free radicals from DPPH were scavenged by AFMF at 0.11 mg/ml. Total phenolic and flavonoid contents of AFMF were 51.0 mg GAE/g and 27 mg QE/g, respectively. Rutin was elucidated by the UPLC technique, and thereby suspected to be the phytochemical responsible for the observed antimutagenic activity. Thus far, AFMF seems to contain a promising chemotherapeutic agent for the prevention of genetic damage that is crucial for cancer development.

Fulltext A review of roll-to-roll nanoimprint lithography

Kooy N, Mohamed K, Pin LT, Guan OS

Nanoscale Res Lett, 2014;9(1):320.

PMID: 25024682 DOI: 10.1186/1556-276X-9-320

Since its introduction in 1995, nanoimprint lithography has been demonstrated in many researches as a simple, low-cost, and high-throughput process for replicating micro- and nanoscale patterns. Due to its advantages, the nanoimprint lithography method has been rapidly developed over the years as a promising alternative to conventional nanolithography processes to fulfill the demands generated from the recent developments in the semiconductor and flexible electronics industries, which results in variations of the process. Roll-to-roll (R2R) nanoimprint lithography (NIL) is the most demanded technique due to its high-throughput fulfilling industrial-scale application. In the present work, a general literature review on the various types of nanoimprint lithography processes especially R2R NIL and the methods commonly adapted to fabricate imprint molds are presented to provide a clear view and understanding on the nanoimprint lithography technique as well as its recent developments.

Fulltext Evaluation of cytogenotoxic and antimutagenic potency of water extract of Centella asiatica Linn. using the Allium cepa assay

Akinboro, A., Baharudeen, I., Mohamed, K.

International Food Research Journal, 2016;23(6):2449-2452.

MyJurnal

In this study, toxicological safety (mutagenicity) and therapeutic potential (antimutagenicity)
of water extract of Centella asiatica Linn., were evaluated using the Allium cepa assay. The
mitotic index (MI) at 6.25% concentration of the extract decreased significantly from 3.13% to
2.05% after 24 h and 48 h, respectively, however, the MI increased significantly by 60% and
400% at 12.5% and 50.0% concentrations, respectively. There was total arrest of cell division
at 100% concentration after 24 h and 48 h of onion’s roots exposure to the water extract.
The chromosomal aberrations (CA) induced by the extract were not significantly different
from the negative control (p ≥ 0.05) at the tested concentrations. The mutagenic activity of
cyclophosphamide was significantly suppressed above 50% at the tested concentrations. These
results suggest non-genotoxic effect, and antimutagenic potency of water extract of C. asiatica
in A. cepa cells, being desirable characteristics of anticancer therapeutics.

Fulltext Comparative validity of a Food Frequency Questionnaire (MyUM Adolescent FFQ) to estimate the habitual dietary intake of adolescents in Malaysia

Mohamed K, Tin TS, Jalaludin MY, Al-Sadat N, Majid HA

Asia Pac J Clin Nutr, 2018 7 27;27(4):898-907.

PMID: 30045437 DOI: 10.6133/apjcn.022018.03

BACKGROUND AND OBJECTIVES: The food frequency questionnaire (FFQ) is a dietary tool used to assess the habitual intake of the population. The goal of this study is to examine the reproducibility and validity of the FFQ that was developed for a multi-ethnic population in Malaysia.

METHODS AND STUDY DESIGN: Collective food data from MyHeARTs 2012 database were used to construct the MyUM Adolescent FFQ. Seventy-eight participants between 13 and 15 years old in 2014 were selected through convenient sampling for test-retest study. They completed the MyUM Adolescent FFQ twice, with an interval period of one week. One hundred and fifty-six MyHeARTs study participants who were 15 years old in 2014 were randomly selected for this comparative valid-ity study. They completed a 7-day diet history (7DDH) and subsequently completed the self-administered MyUM Adolescent FFQ.

RESULTS: Pearson's correlations between the FFQ and 7DDH for all macronutrients were statistically significant. Energy-adjusted correlations for protein, carbohydrate, and fat were 0.54, 0.63 and 0.49 respectively. Most of the micronutrients and minerals, were statistically correlated ranging from 0.31 to 0.49 after energy adjustment. Cross-classification analyses revealed that more than 70 percent of adolescents were classified into either the same or adjacent quartile of nutrient intake when comparing data of 7DDH and FFQ. No serious systematic bias was evident in the Bland-Altman plots.

CONCLUSION: The 200-item FFQ developed for Malaysian adolescents has moderate to good comparative validity for assessment of macronutrient and micronutrient intake.

Fulltext NiO nanoparticles induce cytotoxicity mediated through ROS generation and impairing the antioxidant defense in the human lung epithelial cells (A549): Preventive effect of Pistacia lentiscus essential oil

Mohamed K, Zine K, Fahima K, Abdelfattah E, Sharifudin SM, Duduku K

Toxicol Rep, 2018;5:480-488.

PMID: 29854619 DOI: 10.1016/j.toxrep.2018.03.012

Nickel oxide nanoparticles (NiO NPs) have attracted increasing attention owing to potential capacity to penetrate to several human cell systems and exert a toxic effect. Elsewhere, the use of medicinal plants today is the form of the most widespread medicine worldwide. Utilizing aromatic plants as interesting source of phytochemicals constitute one of the largest scientific concerns. Thus this study was focused to investigate antioxidant and cytoprotective effects of essential oil of a Mediterranean plant P. lentiscus (PLEO) on NiO NPs induced cytotoxicity and oxidative stress in human lung epithelial cells (A549). The obtained results showed that cell viability was reduced by NiO NPs, who's also found to induce oxidative stress in dose-dependent manner indicated by induction of reactive oxygen species and reduction of antioxidant enzymes activities. Our results also demonstrated that PLEO contains high amounts in terpinen-4-ol (11.49%), germacrene D (8.64%), α-pinene (5.97%), sabinene (5.19%), caryophyllene (5.10%) and δ-Cadinene (4.86%). PLEO exhibited a potent antioxidant capacity by cell viability improving, ROS scavenging and enhancing the endogenous antioxidant system against NiO NPs in this model of cells. The present work demonstrated, for the first time, the protective activity of PLEO against cell oxidative damage induced by NiO NPs. It was suggested that this plant essential oil could be use as a cells protector.

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