The assessment of the beta-adrenoceptor blocking activity and cardioselectivity of Koe 3290 in normal subjects

Comparisons of screening strategies for identifying Lynch syndrome among patients with MLH1-deficient colorectal cancer

BRAF and MLH1 promoter methylation testings have been proven effective prescreens for Lynch Syndrome. We aimed to compare different screening strategies for Lynch Syndrome in patients with MLH1(-) CRC. Patients with MLH1(-) CRC who had been tested for BRAF mutation and germline variants of DNA mismatch repair genes were included. We compared the sensitivities and specificities for identifying Lynch Syndrome and the cost-effectiveness of four screening approaches that used the following tests as prescreens: BRAF testing, MLH1 methylation testing, MLH1 methylation & BRAF testing, and MLH1 methylation testing & Revised Bethesda Criteria. Of 109 patients included, 23 (21.1%) were Lynch Syndrome patients. BRAF mutation and MLH1 methylation occurred in 6 (5.5%) and 40 (36.7%) patients, respectively. The sensitivity for identifying Lynch syndrome of BRAF testing was 100%, but the specificity was only 7%. MLH1 methylation testing had a lower sensitivity than BRAF testing (97.5% vs 100%), but had a markedly higher specificity (45.3% vs 7%). The combination of the two testings had a slightly higher specificity than MLH1 methylation testing alone (47.7% vs 45.3%). The MLH1 methylation testing approach had a 10% lower cost of identifying MLH1(-) Lynch syndrome carriers per case than universal genetic testing, but it missed 4.5% of patients. BRAF and MLH1 promoter methylation testings as prescreens for Lynch syndrome are less effective in Chinese patients with MLH1(-) CRC than in their Western counterparts. Universal genetic testing could be considered an up-front option for this population.

Characterization of the beta-adrenoreceptors which mediate the isoprenaline-induced changes in finger tremor and cardiovascular function in man

We have studied the contribution of beta 1- and beta 2-adrenoceptors to the isoprenaline-induced changes in heart rate, blood pressure, forearm blood flow, peripheral vascular resistance, and finger tremor. This was achieved by a comparison of the effects of atenolol 50 mg, ICI 118551 25 mg, propranolol 80 mg, atenolol 50 mg combined with ICI 118551 25 mg, propranolol 80 mg combined with ICI 118551 25 mg, and placebo. Atenolol 50 mg and ICI 118551 25 mg caused similar attenuations in the isoprenaline-induced changes in heart rate and diastolic blood pressure, but the responses after the combination of atenolol and ICI 118551 were similar to those after propranolol 80 mg. There was no difference in the forearm blood flow responses to isoprenaline after atenolol 50 mg and ICI 118551, but atenolol 50 mg did not reduce peripheral vascular resistance compared with placebo. Both responses after treatment with atenolol combined with ICI 118551 were similar to those after propranolol 80 mg. Finger tremor responses to isoprenaline were antagonized by ICI 118551 alone and in combination with propranolol and atenolol but not by atenolol alone, suggesting that the response is beta 2-adrenoceptor-mediated. We conclude that the cardiovascular responses to isoprenaline are mediated by both beta 1- and beta 2-adrenoceptors, whereas the finger tremor response is mediated by beta 2-adrenoceptors.