Updated data on permanent cardiac pacing in Malaysia is presented. Over the past 3 1/2 years (1976-1980), 75 patients underwent insertion of pacemakers giving an annual incidence of about 20 cases as compared with a total of 21 cases in the previous 8 years (1968-1977). Many of the features reported in an earlier paper in 1977 viz mode of presentation, age and sex distribution and indications for pacing remain unchanged. Over this period only 4 patients required lead replacement. Since concentrating mainly on the use of epicardial leads implanted via a subxiphoid approach, complications have been remarkably low. The problem of availability of pacemakers has been averted. Cost remains a major consideration when recommending one pacemaker in preference over another. The details concerning clinical features, indications for pacing, complications and other problems encountered in the management of these patients are discussed.
The human concentrative nucleoside transporter (hCNT2), also known as SLC28A2, plays an important role in the cellular uptake across intestinal membrane of some naturally occurring nucleosides and nucleoside analogs. This study aims to determine the genetic variability of hCNT2 (SLC28A2) in three major Asian ethnic groups residing in Singapore: Chinese, Malay and Indian, and functionally characterize the variants of hCNT2. Healthy participants (n=96) from each group were screened for genetic variations in the exons of hCNT2 (SLC28A2) using denaturing high performance liquid chromatography and sequencing analyses. A total of 23 polymorphisms were identified in the exonic and flanking intronic regions, and ethnic differences in single nucleotide polymorphism frequencies were evident. Five novel nonsynonymous variants (L12R, R142H, E172D, E385K, M612T) were constructed by mutagenesis and functionally characterized in U-251 cells. Expression of these variants in U-251 cells revealed that all except E385K can uptake various substrates of hCNT2: inosine, ribavirin and uridine.
Allergens of Dermatophagoides and Blomia species are well-characterized but not for other species. This study was conducted to determine the prevalence of allergic sensitization to house dust (HDM) and storage mites (SM). One hundred adult subjects (aged ≥ 18) were recruited. The mite specific IgE of all allergic subjects were higher compared with healthy subjetcs despite being not statistically significant except for D. farinae and G. malaysiensis. The mean serum IgE levels against HDM and SM for allergic subjects were significantly higher compared with those in healthy subjects. They were mainly sensitized to Dermatophagoides farinae (35%) and Glycycometus malaysiensis (37%). Immunoblots revealed not all allergic subjects showed positive immuno-reactivity against the mites tested. Single or multiple bands were observed for different species. The subjects were commonly sensitized to Group 2 (9-12 kDa), 10 (38 kDa) and 18 (40-48 kDa) allergens. Twenty-one out of 60 allergic subjects were sensitized to either one or more species. The majority of them (71%) were sensitized to single species. The allergic subjects were mainly sensitized to D. pteronyssinus, followed by Tyrophagus putrecentiae and Aleuroglyphus ovatus. Seven were solely sensitized to HDM while 10 were solely sensitized to SM. Four subjects were sensitized to both. Pre-adsorption study revealed no cross-reactivity. There was difference between the prevalence and reactivity to allergens of HDM and SM in these subjects. Both ELISA and immunoblot did not correlate well but can complement each other in improving the detection of mite allergens to the species level.
To determine and compare the distribution of the FcgammaRIIIa 176 F/V polymorphism across three ethnically distinct populations (Chinese, Asian Indians and Malays) in Singapore.
The biophotovoltaic cell (BPV) is deemed to be a potent green energy device as it demonstrates the generation of renewable energy from microalgae; however, inadequate electron generation from microalgae is a significant impediment for functional employment of these cells. The photosynthetic process is not only affected by the temperature, CO2 concentration and light intensity but also the spectrum of light. Thus, a detailed understanding of the influences of light spectrum is essential. Accordingly, we developed spectrally optimized light using programmable LED arrays (PLA)s to study the effect on algae growth and bioelectricity generation. Chlorella is a green microalga and contains chlorophyll-a (chl-a), which is the major light harvesting pigment that absorbs light in the blue and red spectrum. In this study, Chlorella is grown under a PLA which can optimally simulate the absorption spectrum of the pigments in Chlorella. This experiment investigated the growth, photosynthetic performance and bioelectricity generation of Chlorella when exposed to an optimally-tuned light spectrum. The algal BPV performed better under PLA with a peak power output of 0.581 mW m-2 for immobilized BPV device on day 8, which is an increase of 188% compared to operation under a conventional white LED light source. The photosynthetic performance, as measured using pulse amplitude modulation (PAM) fluorometry, showed that the optimized spectrum from the PLA gave an increase of 72% in the rETRmax value (190.5 μmol electrons m-2 s-1), compared with the conventional white light source. Highest algal biomass (1100 mg L-1) was achieved in the immobilized system on day eight, which translates to a carbon fixation of 550 mg carbon L-1. When artificial light is used for the BPV system, it should be optimized with the light spectrum and intensity best suited to the absorption capability of the pigments in the cells. Optimum artificial light source with algal BPV device can be integrated into a power management system for low power application (eg. environment sensor for indoor agriculture system).