Abdulrahman Alfuraih

Vitamin D production in UK Caucasian and South Asian women following UVR exposure.

BACKGROUND It is known that skin pigmentation reduces the penetration of ultraviolet radiation (UVR) and thus photosynthesis of 25-hydroxvitamin D (25(OH)D). However ethnic differences in 25(OH)D production remain to be elucidated. OBJECTIVE The aim of this study was to investigate differences in vitamin D production between UK South Asian and Caucasian postmenopausal women, in response to a defined and controlled exposure to UVR. DESIGN Seventeen women; 9 white Caucasian (skin phototype II and III), 8 South Asian women (skin phototype IV and V) participated in the study, acting as their own controls. Three blood samples were taken for the measurement of vitamin D status during the run in period (9days, no sunbed exposure) after which, all subjects underwent an identical UVR exposure protocol irrespective of skin colour (9 days, 3 sun bed sessions, 6, 8 and 8min respectively with approximately 80% body surface exposed). Skin tone was measured four times during the study. RESULTS Despite consistently lower 25(OH)D levels in South Asian women, they were shown to synthesise vitamin D as efficiently as Caucasians when exposed to the same dose of UVR. Interestingly, the baseline level of vitamin D rather than ethnicity and skin tone influenced the amount of vitamin D synthesised. CONCLUSIONS This study have found no ethnic differences in the synthesis of 25(OH)D, possibly due to the baseline differences in 25(OH)D concentration or due to the small population size used in this study. Applying mixed linear model, findings indicated no effect of ethnicity and skin tone on the production of vitamin D; baseline level and length of exposure were the critical factors. To confirm that ethnicity and skin tone has no effect on 25(OH)D production, a larger sample size study is required that considers other ethnic groups with highly pigmented skin. Initial vitamin D status influences the amount of UVB needed to reach equal serum concentrations.

Magnetic Targeting and Delivery of Drug-Loaded SWCNTs Theranostic Nanoprobes to Lung Metastasis in Breast Cancer Animal Model: Noninvasive Monitoring Using Magnetic Resonance Imaging.

PurposeIn this study, we aimed to develop novel therapeutic and diagnostic approaches by improving the targeting of doxorubicin-loaded single-walled carbon nanotubes (SWCNTs) to metastatic regions, and monitor their preferential homing and enhanced therapeutic effect using noninvasive free-breathing magnetic resonance imaging (MRI) and bioluminescence imaging.ProceduresHigh-energy flexible magnets were specifically positioned over the metastatic tumor sites in the lungs. SWCNTs biodistribution, tumor progression, and subsequent treatment efficiency were assessed following administration of the magnetically attracted doxorubicin-loaded anti-CD105 conjugated nanocarriers.ResultsThe use of high-energy magnets offered improved theranostic effect of doxorubicin-loaded nanocarriers, by magnetically targeting them towards metastatic tumor sites in the lungs. MRI allowed sensitive monitoring of nanocarriers biodistribution in the abdominal organs, their preferential homing towards the metastatic sites, and their enhanced therapeutic effect.ConclusionsCombination of noninvasive MRI to localize sensitively the tumor sites, with specific positioning of magnets that can enhance the magnetic targeting of nanocarriers, allowed increasing the treatment efficiency.

Breast Cancer Epidemiology in Gulf Cooperation Council Countries: A Regional and International Comparison

Abstract Breast cancer is the most frequently diagnosed noncutaneous malignancy in women living in Gulf Cooperation Council countries. The present report aimed to highlight the similarities and variations in breast cancer incidence, age at diagnosis, clinicopathologic features, molecular characteristics, and lifestyle factors that contribute to an increasing incidence of breast cancer compared with neighboring Arab and westernized countries. The data presented, although having important implications for policy makers, also highlights the need for further research. Such research would ensure that effective prevention and detection strategies are tailored to the specific needs of the Gulf women such that the management of breast cancer is optimized.

Measurement of three gamma annihilation by lanthanum-based crystals compared with NaI(Tl) and HPGe

The relative yield of 3γ to 2γ annihilation was measured for a positron emitter, 22Na, with the new scintillator detectors lanthanum chloride (LaCl3:Ce) and lanthanum bromide (LaBr3:Ce), which had been characterised for comparison with high-purity germanium (HPGe) and sodium iodide (NaI(Tl)) detectors. The information obtained from the ortho-positronium 3γ decay in positron emission tomography (PET) can be a measure of the oxygen content in biological tissues by determination of this relative yield. However, it requires high resolution spectroscopy and detection efficiency. Characterisation of the new generation of scintillator detectors determines whether they could replace conventional scintillators and semiconductors. A series of experiments was carried out with different samples in order to study the effect of ortho-positronium formation. The peak-to-peak and the peak-to-valley methods were compared in the measurement of the relative yield of 3γ to 2γ annihilation.