Elevation of zinc protoporphyrin (ZPP) levels in the blood has served as an indicator of lead poisoning and iron deficiency anemia for many years. We have discovered that sublethal doses of whole body irradiation with x-rays also elevates ZPP 2-3-fold over normal levels. The ZPP level does not begin to increase until days 12-14 postirradiation and peaks between days 18 and 20 before returning t...

Two recently developed kinematic models of human eye movements predict systematic departures from Listing's law which are associated with changes in vergence. This vergence-dependent torsion t is proportional to elevation e and vergence v, that is t = kev/2. The proposed value for k is either 1 (Van Rijn, L. J., & Van den Berg, A. V. (1993). Vision Research, 33, 691-708) or 1/2 (Minken, A. W. H...

1. Chan E. Thrombolytic service of acute ischaemic stroke in Hong Kong. Hong Kong Med J 2012;18:170. 2. Lau AY, Soo YO, Graham CA, et al. An expedited stroke triage pathway: the key to shortening the door-to-needle time in delivery of thrombolysis. Hong Kong Med J 2010;16:455-62. 3. Cheung NK, Yeung JH, Chan JT, Cameron PA, Graham CA, Rainer TH. Primary trauma diversion: initial experience in H...

In 1975, dihydropteridine reductase (DHPR) deficiency was first recognized as a cause of tetrahydrobiopterin (BH4) deficiency, leading to hyperphenylalaninemia (HPA) and impaired biogenic amine deficiency. So far, more than 150 patients scattered worldwide have been reported and major progresses have been made in the understanding of physiopathology, screening, diagnosis, treatment, and molecul...

PURPOSE To evaluate the effects of the wearer's pupil size and spherical aberration on visual performance with centre-near, aspheric multifocal contact lenses (MFCLs). The advantage of binocular over monocular vision was also investigated. METHODS Twelve young volunteers, with an average age of 27 ± 5 years, participated in the study. LogMAR Visual Acuity (VA) was measured under cycloplegia f...

A t one time, the diagnosis of a deficiency of vitamin B12 or folate was considered to be relatively straightforward. As knowledge has accumulated, the limitations of such tests as serum vitamin level measurements and the Schilling test have become apparent. With the development of newer tests, atypical and subclinical deficiency states have been recognized. In this review, available tests used...

Vitamin D deficiency is one of the major health problems that is unexpectedly prevalent in Iran. The ultraviolet (UV) rays of the sunlight are the most important source of vitamin D in humans. In contrast, environmental factors are one of the reasons for decrease in UV transmission to the earth which results in the reduction of vitamin D absorption. Since the role of environmental factors has b...

Apolipoprotein E (apoE) is hypothesized to mediate lipoprotein clearance by binding to two receptors: (i) the low density lipoprotein receptor (LDLR) and (ii) a chylomicron remnant receptor. To test this hypothesis, we have compared plasma lipoproteins in mice that are homozygous for targeted disruptions of the genes for apoE [apoE(-/-)], the LDLR [LDLR(-/-)], and both molecules [poE(-/-); LDLR...