Publications by authors named "S K Addae"

We report a new approach to colorimetric Enzyme-Linked Immunosorbent Assay (ELISA) that reduces the total assay time to < 2 min and the lower-detection-limit by 100-fold based on absorbance readout. The new approach combines the use of silver nanoparticles, microwaves and split ring resonators (SRR). The SRR structure is comprised of a square frame of copper thin film (30 µm thick, 1 mm wide, overall length of ~9.

View Article and Find Full Text PDF

In this paper, we have reported that split ring resonators (SRRs) structures can be used for bioassay applications in order to further improve the assay time and sensitivity. The proof-of-principle demonstration of the ultrafast bioassays was accomplished by using a model biotin-avidin bioassay. While the identical room temperature bioassay (without microwave heating) took 70 min to complete, the identical bioassay took less than 2 min to complete by using SRR structures (with microwave heating).

View Article and Find Full Text PDF

Analysis of available radiographs of the skeletal system in 50 patients suffering from sickle cell anaemia in the Assir Region (South Western height and valley) of the Kingdom of Saudi Arabia taken over a three year period showed a wide spectrum of bone changes. Both infarctions and medullary hyperplasia were common, producing the usual previously reported changes. Spinal changes, mostly osteoporosis and vertebral end plate depression were more prominent in the younger age group.

View Article and Find Full Text PDF

The concentrations of serum calcium, parathyroid hormone (PTH), 25 Hydroxyvitamin D (25OHD), and 1,25 Dihydroxyvitamin D (1,25(OH)2D) were determined in 99 Saudi patients with sickle cell disease and in 104 matching healthy controls. Serum calcium and 25OHD were significantly lower in the patients, with 14% and 12% of them had serum calcium and 25OHD concentrations, respectively, below the normal range. PTH was significantly higher in the patients, with 31% having values above the normal range.

View Article and Find Full Text PDF

Serum alkaline phosphatase, alkaline phosphatase isoenzymes, and urinary hydroxyproline excretion were studied in 20 young adult sickle cell patients and 58 matching normal controls. Total alkaline phosphatase was significantly higher in the sickle cell patients than in controls. Heat inactivation test and isoenzyme electrophoresis indicated that bone is the predominant isoenzyme in patients.

View Article and Find Full Text PDF