St Bartholomew's Hospital

About: St Bartholomew's Hospital is a healthcare organization based out in London, United Kingdom. It is known for research contribution in the topics: Population & Cancer. The organization has 11054 authors who have published 13229 publications receiving 501102 citations. The organization is also known as: St. Bartholomew's Hospital & The Royal Hospital of St Bartholomew.

Prevention of blindness by screening for diabetic retinopathy: a quantitative assessment.

Abstract: Diabetic retinopathy is an important cause of blindness in the Western World. A review of the randomised trials of laser photocoagulation of the retina as a method of preventing blindness from this disorder showed that this treatment is very effective, reducing the risk of blindness by 61% in a treated eye. As only one eye is needed for sight the reduction in blindness in a population will be greater than 61% because the effect of treatment in one eye is not always identical with the effect in the other eye. For analysis this reduction was taken as 73%, representing the average of the minimum and maximum estimates (61% and 85%). The effectiveness of this treatment suggests that there is the potential for a national screening programme to bring about a major reduction in blindness from this cause. A quantitative assessment of the effect of screening indicated that a programme in which patients with diabetes mellitus are systematically referred to ophthalmic opticians for a retinal examination could detect 88% of all diabetics with serious retinopathy and that 87% of these cases would be treatable. Screening and early treatment of retinopathy would prevent deterioration of visual acuity and could reduce the risk of blindness due to diabetic retinopathy by an estimated 56% (0.73 X 0.88 X 0.87). The findings suggest that an effectively managed community based screening programme encompassing detection, referral, treatment, and follow up would prevent about 260 new cases of blindness in diabetics under the age of 70 each year in England and Wales. This would represent over 10% of all cases of blindness in adults in this age group.

Pregnancy tests: a review.

Abstract: Pregnancy tests are widely used both by the public and by healthcare professionals. All tests depend on the measurement of human chorionic gonadotrophin (HCG) in urine. Other pregnancy-specific materials have been proposed as pregnancy tests but none can better the sensitivity and convenience offered by immunoassay of HCG. Ultrasound detection is also not as sensitive as HCG measurement. The current generation of tests is based on monoclonal antibodies to the beta-subunit of HCG; these virtually eliminate the possibility of cross-reaction with pituitary luteinizing hormone (LH) and it is this feature which permits the high sensitivity. However, it is important to recognize that the 'beta-subunit' antibody reacts with both intact HCG, which is the major component in pregnancy serum, and with fragments of the beta-subunit (beta-core), which are the major form in urine. Both the blood and urine of non-pregnant subjects contain small amounts of HCG. HCG from the implanting blastocyst first appears in maternal blood around 6-8 days following fertilization; the levels rise rapidly to reach a peak at 7-10 weeks. With most current pregnancy test kits (sensitivity 25 units per litre) urine may reveal positive results 3-4 days after implantation; by 7 days (the time of the expected period) 98% will be positive. A negative result 1 week after the missed period virtually guarantees that the woman is not pregnant. With the present generation of test kits, false positive results due to interfering materials are extremely unlikely. Pregnancy tests have now reached a level of sensitivity and specificity which is unlikely to be surpassed either by better tests or alternative technology.