Cornelia de Lange syndrome (CdLS) is a multisystem congenital anomaly disorder characterized by prenatal and postnatal growth retardation, developmental delay, distinctive facial dysmorphism, limb malformations, and multiple organ defects. Mutations in the NIPBL gene have been discovered recently as a major etiology for this syndrome, and were detected in 27-56% of patients. Two groups have found significant differences in the severity or penetrance of some phenotypes between mutation positive and mutation negative patients. Different clinical features have also been described among patients with missense versus truncating mutations. In this study, we identified 13 NIPBL mutations in 28 unrelated Polish CdLS patients (46.4%), 11 were novel. Mutation positive patients were more severely affected in comparison to mutation negative individuals with respect to weight, height, and mean head circumference at birth, facial dysmorphism and speech impairment. Analyses of combined data from this and the two previous studies revealed that the degree of growth, developmental delay and limb defects showed significant differences between patients with and without mutations and between patients with missense and truncating mutations, whereas only a portion of these features differed significantly in any individual study. Furthermore, bioinformatic analyses of the NIPBL protein revealed several novel domains, which may give further clues about potential functions of this protein.

In the present work, a sterically constrained noncoded amino acid, 1-aminocyclohexane-1-carboxylic acid (Acc), was substituted in position 8 of the peptide chain of bradykinin (BK) and position 6, 7, or 8 of its B2 receptor antagonist [D-Arg0,Hyp3,Thi,(5,8)D-Phe7]BK, previously synthesized by Stewart's group, to reduce the flexibility of the peptides, thus forcing the peptide backbone and side chains to adopt specific orientations. Knowing that acylation of the N-terminus of several known B2 blockers with a variety of bulky groups has consistently improved their antagonistic potency in the rat blood pressure assay, the Acc substituted analogues were also synthesized in the N-acylated form with 1-adamantaneacetic acid (Aaa). The activity of eight new analogues was assayed in isolated rat uterus and in rat blood pressure tests. The results clearly demonstrated the importance of the position in the peptide chain into which the sterically restricted Acc residue was inserted. Meanwhile, Acc at positions 6 and 7 led to reduction of antagonistic qualities or even restored the agonism, respectively. Acc at position 8 enhanced antagonistic qualities in both tests. The Acc at position 8 of BK strongly reduced the agonistic potency. In most cases acylation of the N-terminus led either to enhancement of antagonistic potencies or to further decrease of agonistic potency. Our findings offer new possibilities for designing new potent and selective B2 blockers.

A sterically constrained non-coded amino acid, 1-aminocyclopentane-1-carboxylic acid (Apc), was introduced in position 7 or 8 of the bradykinin (BK) B(2) receptor antagonist, [D-Arg(0), Hyp(3), Thi(5, 8), D-Phe(7)]BK, previously synthesized by Stewart's group. This modification is believed to reduce the flexibility of the peptides, thereby forcing the peptide backbone and side chains to adopt specific orientations. Apc substitution was combined with acylation of the N-terminus with 1-adamantaneacetic acid (Aaa). The activity of four new analogues was assayed in isolated rat uterus and in rat blood pressure tests. The results clearly demonstrated that the Apc residue inserted in position 7 led to a reduction of antagonistic properties in the rat uterus assay or even restored the agonism in the blood pressure test, whereas Apc at position 8 enhanced antagonistic potency in both the tests. In both cases, acylation of the N-terminus led to the enhancement of the antagonistic potency. On the basis of these findings, new potent and selective B(2) blockers might be designed.

We assessed the vasodilator effect of endothelium-derived nitric oxide by inhibiting its formation with JV G -monomethyl L-arginine (LNMMA) on systemic and regional hemodynamics in conscious, normotensive rats, using the radioactive microsphere technique. In rats injected with 10 mg/kg LNMMA (n=8), mean blood pressure increased by 16.2±2.6 mm Hg, and heart rate decreased by 543 ±16.7 beats per minute. In comparison with rats injected with 5% dextrose (n=14), cardiac index was lower by 35.6% (/?<0.01), and total peripheral vascular resistance was higher by 51.6% (p<0.01); regional blood flows were lower and vascular resistance higher in most organs. Changes were significant in the heart, kidney, stomach, large intestine, skin, and adrenals (/?<0.05). Preinjection of 100 mg/kg L-arginine prevented the pressor response but only partially attenuated the other hemodynamic effects of LNMMA. Combination of LNMMA with the bradykinin antagonist (D-Arg-Arg-Pro-Hyp-Gly-Thi-Ser-D-Phe-Thi-Arg)trifluoroacetic acid (50 jtg/min for 5 minutes) did not produce systemic or regional effects different from those obtained with LNMMA alone. Combination of LNMMA with indomethacin (10 mg/kg) resulted in additional changes in the cerebral circulation, blood flow decreasing by an additional 44.2% (p<0.01) and vascular resistance increasing by 753% (p<0.01) compared with changes produced by LNMMA alone. The data suggest that endothelium-derived nitric oxide contributes differently to the resting vascular tone of various vascular beds; it mediates most of the vasodilator effects of bradykinin and partly those of prostaglandins, but the effect of the latter on the cerebral circulation is not nitric oxide dependent (Hypertension 1992;19 [suppl II]:II-255-II-261)E ndothelium-derived relaxing factor (EDRF) is a vasodilator substance generated by endothelial cells within the vessel wall. Many vasodilators, such as bradykinin, acetylcholine, and substance P, induce relaxation of isolated vascular tissue by release of EDRF 12 and therefore are called endothelium-dependent vasodilators. Recent evidence indicates that the main EDRF is nitric oxide 3 -11 and that its biosynthetic precursor is L-arginine. 1012 Af G -Monomethyl L-arginine (LNMMA) was found to inhibit vascular nitric oxide production in endothelial cells and thus inhibit relaxation induced by endothelium-dependent vasodilators both in vitro 12 -13 and in vivo. 1415 Inhibition of the endotheliumderived nitric oxide formation by LNMMA increased blood pressure in anesthetized rabbits, 14 rats, 15 and guinea pigs 16 and decreased forearm blood flow in