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Fulltext Laparoscopic sterilization with fallope rings - a Malaysian experience

Abdul Rahman A, Sinnathuray TA, Sivanesaratnam V, Ng KH

Med J Malaysia, 1981 Jun;36(2):92-9.
PMID: 6211595

The early Malaysian experience of laparoscopic sterilisation with the Fallope tubal rings, as undertaken at the Obstetrical and Gynaecological Unit of the University Hospital, University of Malaya in Kuala Lumpur, Malaysia is reported in a study of 291 consecutive females that had had the procedure undertaken during the one year period, May 1975 to April 1976. Of the 291 cases, 247 women were sterilised in the "interval" period, 43 after "menstrual regulation" procedure and one after a spontaneous abortion. General anaesthesia was used in all except one case. The salient socio-demographic, contraceptive and reproductive characteristics of study cases are presented and discussed. The technical problems, the early complications and morbidity encountered in this study are presented and discussed in the light of other similar studies, and in relation to sterilisation by laparoscopic tubal electrocoagulation. The overall impression is that laparoscopic sterilisation with the Fallope tubal rings is preferred to that by tubal electrocoagulation, in view of the possible inadvertent serious electrical burns of other structures during the use of the latter procedure.
An in vitro study comparing two different film-screen combinations in the detection of impacted fish bones

Abdullah BJ, Kaur H, Ng KH

Br J Radiol, 1998 Sep;71(849):930-3.
PMID: 10195007

Dried fish bones from eight species of Malaysian fish were placed in an animal cadaver at four sites (tonsil, valleculae, larynx and oesophagus) and radiographed using a double and a single film-screen combination. The use of the single film-screen combination resulted in visibility of all fish bones placed in the larynx, two of which were not visible on the double film-screen combination. There was a 50% increase of the visibility of the fish bones in the oesophagus using the single film-screen combination. The difference in dose and cost between the two different film-screen combinations was not significant.
In the eyes of the beholder: what we see is not what we get

Abdullah BJ, Ng KH

Br J Radiol, 2001 Aug;74(884):675-6.
PMID: 11511489
Fulltext The impact of teleradiology in clinical practice--a Malaysian perspective

Abdullah BJ, Ng KH, Pathmanathan R

Med J Malaysia, 1999 Jun;54(2):169-74.
PMID: 10972025

Teleradiology is the most mature and rapidly evolving specialty in telemedicine. The use of teleradiology has grown tremendously during the past few years. This article describes the role of teleradiology in health care along with a brief history of its development in tandem with advances in telecommunications and computer technologies. Teleradiology standards, image acquisition, data compression, transmission and image interpretation are summarised. The impact of teleradiology in the practice of radiology, traces the evolution of the modality especially in the Malaysian perspective and its current and future role are discussed.
Fulltext A parallel spatiotemporal saliency and discriminative online learning method for visual target tracking in aerial videos

Aghamohammadi A, Ang MC, A Sundararajan E, Weng Ng K, Mogharrebi M, Banihashem SY

PLoS One, 2018;13(2):e0192246.
PMID: 29438421 DOI: 10.1371/journal.pone.0192246

Visual tracking in aerial videos is a challenging task in computer vision and remote sensing technologies due to appearance variation difficulties. Appearance variations are caused by camera and target motion, low resolution noisy images, scale changes, and pose variations. Various approaches have been proposed to deal with appearance variation difficulties in aerial videos, and amongst these methods, the spatiotemporal saliency detection approach reported promising results in the context of moving target detection. However, it is not accurate for moving target detection when visual tracking is performed under appearance variations. In this study, a visual tracking method is proposed based on spatiotemporal saliency and discriminative online learning methods to deal with appearance variations difficulties. Temporal saliency is used to represent moving target regions, and it was extracted based on the frame difference with Sauvola local adaptive thresholding algorithms. The spatial saliency is used to represent the target appearance details in candidate moving regions. SLIC superpixel segmentation, color, and moment features can be used to compute feature uniqueness and spatial compactness of saliency measurements to detect spatial saliency. It is a time consuming process, which prompted the development of a parallel algorithm to optimize and distribute the saliency detection processes that are loaded into the multi-processors. Spatiotemporal saliency is then obtained by combining the temporal and spatial saliencies to represent moving targets. Finally, a discriminative online learning algorithm was applied to generate a sample model based on spatiotemporal saliency. This sample model is then incrementally updated to detect the target in appearance variation conditions. Experiments conducted on the VIVID dataset demonstrated that the proposed visual tracking method is effective and is computationally efficient compared to state-of-the-art methods.
Optimal beam quality selection based on contrast-to-noise ratio and mean glandular dose in digital mammography

Aminah M, Ng KH, Abdullah BJ, Jamal N

Australas Phys Eng Sci Med, 2010 Dec;33(4):329-34.
PMID: 20938762 DOI: 10.1007/s13246-010-0035-3

The performance of a digital mammography system (Siemens Mammomat Novation) using different target/filter combinations and tube voltage has been assessed. The objective of this study is to optimize beam quality selection based on contrast-to-noise ratio (CNR) and mean glandular dose (MGD). Three composition of breast were studied with composition of glandular/adipose of 30/70, 50/50, and 70/30. CNR was measured using 2, 4 and 6 cm-thick simulated breast phantoms with an aluminium sheet of 0.1 mm thickness placed on top of the phantom. Three target/filter combinations, namely molybdenum/molybdenum (Mo/Mo), molybdenum/rhodium (Mo/Rh) and tungsten/rhodium (W/Rh) with various tube voltage and mAs were tested. MGD was measured for each exposure. For 50/50 breast composition, Mo/Rh combination with tube voltage 26 kVp is optimal for 2 cm-thick breast. W/Rh combination with tube voltage 27 and 28 kVp are optimal for 4 and 6 cm-thick breast, respectively. For both 30/70 and 70/30 breast composition, W/Rh combination is optimal with tube voltage 25, 26 and 27 kVp, respectively. From our study it was shown that there are potential of dose reduction up to 11% for a set CNR of 3.0 by using beam quality other than that are determined by AEC selection. Under the constraint of lowest MGD, for a particular breast composition, calcification detection is optimized by using a softer X-ray beam for thin breast and harder X-ray beam for thick breast. These experimental results also indicate that for breast with high fibroglandular tissues (70/30), the use of higher beam quality does not always increase calcification detection due to additional structured noise caused by the fibroglandular tissues itself.
The empty sella syndrome

Anuar M, Ng KK, Chong KF

Med J Malaysia, 1977 Mar;31(3):244-6.
PMID: 904521
Post partum splenic artery aneurysm rupture

Asokan S, Chew EK, Ng KY, Thanaletchimy N, Asmiati A, Kong NM

J Obstet Gynaecol Res, 2000 Jun;26(3):199-201.
PMID: 10932982

Ruptured splenic artery aneurysm during pregnancy is a rare event with high maternal and fetal mortality rate. A case of ruptured splenic artery aneurysm in the post partum period is presented. The literature is reviewed on pathophysiology, clinical presentation and management of this rare and potentially fatal entity.
A low cost solution for post-biopsy complications using available RFA generator and coaxial core biopsy needle

Azlan CA, Mohd Nasir NF, Saifizul AA, Faizul MS, Ng KH, Abdullah BJ

Australas Phys Eng Sci Med, 2007 Dec;30(4):288-91.
PMID: 18274069

Percutaneous image-guided needle biopsy is typically performed in highly vascular organs or in tumours with rich macroscopic and microscopic blood supply. The main risks related to this procedure are haemorrhage and implantation of tumour cells in the needle tract after the biopsy needle is withdrawn. From numerous conducted studies, it was found that heating the needle tract using alternating current in radiofrequency (RF) range has a potential to minimize these effects. However, this solution requires the use of specially designed needles, which would make the procedure relatively expensive and complicated. Thus, we propose a simple solution by using readily available coaxial core biopsy needles connected to a radiofrequency ablation (RFA) generator. In order to do so, we have designed and developed an adapter to interface between these two devices. For evaluation purpose, we used a bovine liver as a sample tissue. The experimental procedure was done to study the effect of different parameter settings on the size of coagulation necrosis caused by the RF current heating on the subject. The delivery of the RF energy was varied by changing the values for delivered power, power delivery duration, and insertion depth. The results showed that the size of the coagulation necrosis is affected by all of the parameters tested. In general, the size of the region is enlarged with higher delivery of RF power, longer duration of power delivery, and shallower needle insertion and become relatively constant after a certain value. We also found that the solution proposed provides a low cost and practical way to minimizes unwanted post-biopsy effects.
An indicator device for monitoring of room illuminance level in the radiological image viewing environment

Azlan CA, Ng KH, Anandan S, Nizam MS

Australas Phys Eng Sci Med, 2006 Sep;29(3):278-80.
PMID: 17058591

Illuminance level in the softcopy image viewing room is a very important factor to optimize productivity in radiological diagnosis. In today's radiological environment, the illuminance measurements are normally done during the quality control procedure and performed annually. Although the room is equipped with dimmer switches, radiologists are not able to decide the level of illuminance according to the standards. The aim of this study is to develop a simple real-time illuminance detector system to assist the radiologists in deciding an adequate illuminance level during radiological image viewing. The system indicates illuminance in a very simple visual form by using light emitting diodes. By employing the device in the viewing room, illuminance level can be monitored and adjusted effectively.
Molecular cloning, homology modeling and site-directed mutagenesis of vanadium-dependent bromoperoxidase (GcVBPO1) from Gracilaria changii (Rhodophyta)

Baharum H, Chu WC, Teo SS, Ng KY, Rahim RA, Ho CL

Phytochemistry, 2013 Aug;92:49-59.
PMID: 23684235 DOI: 10.1016/j.phytochem.2013.04.014

Vanadium-dependent haloperoxidases belong to a class of vanadium enzymes that may have potential industrial and pharmaceutical applications due to their high stability. In this study, the 5'-flanking genomic sequence and complete reading frame encoding vanadium-dependent bromoperoxidase (GcVBPO1) was cloned from the red seaweed, Fracilaria changii, and the recombinant protein was biochemically characterized. The deduced amino acid sequence of GcVBPO1 is 1818 nucleotides in length, sharing 49% identity with the vanadium-dependent bromoperoxidases from Corralina officinalis and Cor. pilulifera, respectively. The amino acid residues associated with the binding site of vanadate cofactor were found to be conserved. The Km value of recombinant GcVBPO1 for Br(-) was 4.69 mM, while its Vmax was 10.61 μkat mg(-1) at pH 7. Substitution of Arg(379) with His(379) in the recombinant protein caused a lower affinity for Br(-), while substitution of Arg(379) with Phe(379) not only increased its affinity for Br(-) but also enabled the mutant enzyme to oxidize Cl(-). The mutant Arg(379)Phe was also found to have a lower affinity for I(-), as compared to the wild-type GcVBPO1 and mutant Arg(379)His. In addition, the Arg(379)Phe mutant has a slightly higher affinity for H2O2 compared to the wild-type GcVBPO1. Multiple cis-acting regulatory elements associated with light response, hormone signaling, and meristem expression were detected at the 5'-flanking genomic sequence of GcVBPO1. The transcript abundance of GcVBPO1 was relatively higher in seaweed samples treated with 50 parts per thousand (ppt) artificial seawater (ASW) compared to those treated in 10 and 30 ppt ASW, in support of its role in the abiotic stress response of seaweed.
Evaluating the quality of images produced by soft X-ray units

Bradley DA, Wong CS, Ng KH

Appl Radiat Isot, 2000 9 26;53(4-5):691-7.
PMID: 11003508

For broad-beam soft X-ray sources, assessment of the quality of image produced by such units is made complex by the low penetration capabilities of the radiation. In the present study we have tested the utility of several types of test tool, some of which have been fabricated by us, as part of an effort to evaluate several key image defining parameters. These include the film characteristic, focal-spot size, image resolution and detail detectability. The two sources of X-rays used in present studies were the University of Malaya flash X-ray device (UMFX1) and a more conventional soft X-ray tube (Softex, Tokyo), the latter operating at peak accelerating potentials of 20 kVp. We have established, for thin objects, that both systems produce images of comparable quality and, in particular, objects can be resolved down to better than 45 microm.
Use of a modified natural-rubber phantom for radiotherapy dosimetry measurements

Bradley DA, Ng KH, Aziz YB

Int J Rad Appl Instrum A, 1988;39(5):439-40.
PMID: 2840420

The utility of a phantom material, based on SMR(L) [Standard Malaysian Rubber] grade natural rubber and a formulation used for the proprietary rubber phantom-material, Temex, has been examined for the 1-MeV photon-Measurement has also been performed with 60-keV photons using the radionuclide 241Am. At photon-therapy energy levels the measured response, when compared with tabulated central-axis percentage depth doses for the defined measuring conditions, produces everywhere (in the range 1-19 cm depth) better than 2% deviation. The favourable measured response characteristics combined with the ease of processing and casting the phantom material provide the basis for useful radiotherapy machine calibration and anthropomorphic dosimetry measurements. The measured mass-attenuation coefficient, at 60keV, of 0.204 cm2 g-1 (+/- 3%) is in close agreement with tabulated values for water (0.2055 cm2 g-1).
Anesthetic management of a parturient with superior vena cava obstruction for cesarean section

Chan YK, Ng KP, Chiu CL, Rajan G, Tan KC, Lim YC

Anesthesiology, 2001 Jan;94(1):167-9.
PMID: 11135739
A survey of the current practice of obstetric anaesthesia and analgesia in Malaysia [correction of Malaysis]

Chan YK, Ng KP

J Obstet Gynaecol Res, 2000 Apr;26(2):137-40.
PMID: 10870307

OBJECTIVE: A survey covering 30% of the deliveries in Malaysia was done to determine the practice of obstetric anaesthesia and analgesia for 1996.
RESULTS: From the survey, it was found that the regional anaesthesia rate for caesarean section was 46% in the government hospitals compared to 29.2% in the private hospitals, with spinal anaesthesia being the most common regional anaesthetic technique used in both types of hospitals. The epidural rate for labour analgesia was only 1.5% overall for the country. Epidural analgesia services were available in all private hospitals whereas 17.6% of government hospitals surveyed did not offer this service at all.
CONCLUSIONS: Although the use of epidural analgesia for labour was low in Malaysia, the overall rate of regional anaesthesia for caesarean section (41.9%) is very much in keeping with the standards of safe practice recommended by the United Kingdom.
Trends in obstetric anaesthesia and analgesia over a ten year period in the University Malaya Medical Centre, Kuala Lumpur

Chan YK, Ng KP, Chiu CL

Int J Obstet Anesth, 2002 Jul;11(3):176-9.
PMID: 15321544 DOI: 10.1054/ijoa.2002.0954

Available data for obstetric care in the University Malaya Medical Centre, Kuala Lumpur from 1987 to 1999 were reviewed. Despite incomplete data, we were able to determine fairly well the practice of obstetric anaesthesia and analgesia in the unit, and the changes over the years. There was a decline in the use of general anaesthesia for both elective and emergency caesarean sections from 41.3% and 69.4% respectively in 1995 to 21.6% and 26.9% respectively in 1999. By 1999, regional anaesthesia had become the most common method of anaesthesia administered in both elective (14.3% epidural and 63.5% spinal) and emergency (30.2% epidural and 42.6% spinal) caesarean sections. The percentage of patients delivering vaginally who received epidural analgesia appeared to have stabilised at about 8 to 9% in the last few years, with a gradual decline in the total instrumental delivery rate from a high of about 12% to the pre-epidural rate of 7%.
A survey of regional analgesia and anaesthesia for obstetrics in selected countries in the Far East

Chan YK, Ng KP

Int J Obstet Anesth, 2000 Oct;9(4):225-32.
PMID: 15321075

A survey was conducted in several countries in the Far East in an attempt to determine the practice of obstetric analgesia and anaesthesia there. Survey forms were sent to a total of 11 countries but in the end responses from only four countries were able to provide useful information. Responses from Singapore, Hong Kong, Taiwan and Malaysia covered between 44.9% (Singapore) and 24.6% (Malaysia) of their countries' total deliveries in 1997 and were thought to be adequate to give an impression of the obstetric analgesia and anaesthesia services in their respective countries, although this would not necessarily be completely accurate. From our survey, we found that the availability of regional analgesia for labour paralleled the economic status of the country and that a significant number of caesarean sections are conducted under regional anaesthesia, mainly spinals.
The effects of oestradiol and relaxin on extensibility and collagen organisation of the pregnant rat cervix

Cheah SH, Ng KH, Johgalingam VT, Ragavan M

J Endocrinol, 1995 Aug;146(2):331-7.
PMID: 7561646

The effects of exogenously introduced oestradiol-17 beta (E) and relaxin (RLX) on cervical extensibility and collagen organisation were tested in rats ovariectomised in late pregnancy. When the cervices were stretched in vitro by 1 mm increments, it was found that those from rats given E alone generated significantly higher tensions than those from control rats, while cervices from rats given both E and RLX had tensions similar to controls. Examination of cervical sections under the light microscope and ultra-thin sections under the electron microscope showed that the collagen fibres in the cervices from E-treated rats were highly organised, whereas those from animals given E+RLX and control animals were disorganised and dispersed. It was concluded that E decreased cervical extensibility, while RLX counteracted the effect of E to maintain a soft and easily extensible cervix.
Fulltext A review of dengue research in Malaysia

Cheah WK, Ng KS, Marzilawati AR, Lum LC

Med J Malaysia, 2014 Aug;69 Suppl A:59-67.
PMID: 25417953 MyJurnal

Dengue infection is a major cause of morbidity and mortality in Malaysia. To date, much research on dengue infection conducted in Malaysia have been published. One hundred and sixty six articles related to dengue in Malaysia were found from a search through a database dedicated to indexing all original data relevant to medicine published between the years 2000-2013. Ninety articles with clinical relevance and future research implications were selected and reviewed. These papers showed evidence of an exponential increase in the disease epidemic and a varying pattern of prevalent dengue serotypes at different times. The early febrile phase of dengue infection consist of an undifferentiated fever. Clinical suspicion and ability to identify patients at risk of severe dengue infection is important. Treatment of dengue infection involves judicious use of volume expander and supportive care. Potential future research areas are discussed to narrow our current knowledge gaps on dengue infection.
Fulltext Anthropometry, dietary patterns and nutrient intakes of Malaysian estate workers

Chee S, Zawiah H, Ismail M, Ng K

Malays J Nutr, 1996 Sep;2(2):112-26.
PMID: 22692134 MyJurnal

Studies were carried out in two estates in Kedah and Johor to characterize the anthropometry and dietary patterns of 334 (169 females, 165 males) Malaysian estate workers. Subjects were Malay and Indian adults (aged 18 to 60 years) engaged in various work activities including rubber tappers, palm fruit harvesters, field supervisors and workers in the estate factories. Anthropometric results showed that the prevalence of overweight (26% in men, 25% in women) and obesity (5% in men, 11% in women) were higher compared to prevalence of underweight (11% in men, 9% in women) in these workers despite being engaged in moderate to heavy activities. The dietary intake pattern revealed that the main sources of calories in the diet were rice, cooking oil and sugar. Major sources of protein in the Malay diet were anchovies and fish whilst in the Indian diet protein was provided by salted fish, anchovies, eggs, fish, and pulses. The consumption of poultry, meat and dairy products were low for both ethnic groups. The dietary intakes of a subsampel of 108 normal weight subjects (56 females, 52 males) were recorded for 3 days. The results showed that the mean energy intake was 8.44 ± 2.12 MJ in males and 6.48 ± 1.29 MJ in females. The contribution of calories from protein, fat and carbohydrate were 13%, 22% and 60% in males and 12%, 23% and 65% in females, respectively. Alcohol intake was found to contribute five percent of energy in the diet of the Indian male subjects. Calcium, iron, vitamin A, thiamin, riboflavin and niacin intake were below 66% of the Malaysian RDA, particularly amongst the women. Income appeared to have a significant correlation with energy and iron intakes of the female workers as well as thiamin, niacin and riboflavin intakes of the male workers. There is a need for improving the quality of the dietary intakes of these workers as well as nutrition education on the prevention of obesity and its consequences.

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