[Following 90 patients with antiphospholipid syndrome with antibody titers and correlations with clinical manifestations: symptoms of the disease, a new antibody and correlations with clinical manifestations in the Israeli population].

UNLABELLED: The antiphospholipid syndrome (APS) is defined by the presence of antiphospholipid antibodies (aPLs) with venous or arterial thrombosis, recurrent pregnancy loss or thrombocytopenia. The syndrome can be either primary or secondary to an underlying condition, most commonly systemic lupus erythematosus (SLE). The purpose of the study was to review the manifestations of the APS in Israeli patients and to investigate the difference between patients with primary or secondary syndrome. Analysis of the correlation between the manifestations of the disease and the antibody titers [LA (lupus anticoagulant), IgG aCL (anticardiolipin), IgM aCL] was also performed. In the study there were 90 patients with APS in the Sheba Medical Center. The clinical findings for all patients were recorded according to established protocol. RESULTS: Arterial thrombotic events were present in 51.1% of the patients; cerebral ischemic attacks were the most frequent arterial events. Venous thrombotic events were present in 45.6% patients; deep venous thrombosis was the most frequent venous event. Obstetric complications were found in 37.3% of patients; the most frequent complication was abortions. The clinical findings of patients with primary or secondary syndrome were similar. Patients with APS associated with lupus had a high prevalence of hemolytic anemia (28.6% v 3.3%; P = 0.001), and ANA (antinuclear antibody) (75% v 12.9%; P = 0.0001). There was no correlation between the antibody titers (LA, IgG aCL, IgM aCL) and clinical manifestations. The patients received anticoagulant treatment and antiaggregant drugs to prevent recurrence of symptoms. Clinical manifestations in Israeli patients did not differ from those in non-Israeli patients. CONCLUSIONS: Venous or arterial thrombosis and obstetric complications are the most frequent clinical findings in APS. There was no different in clinical manifestations between primary and secondary syndrome. The findings of autoimmune hemolytic anemia and ANA were more frequent in patients with secondary APS. There was no correlation between antiphospholipid antibody titers and manifestations of disease. Overall, the patients require therapy with anticoagulant treatment and antiaggregant drugs. The clinical manifestations were similar in Israeli and non-Israeli patients.

Antisense effects of cholesterol-oligodeoxynucleotide conjugates associated with poly(alkylcyanoacrylate) nanoparticles.

Oligonucleotides covalently attached to a cholesteryl moiety are more stable in biological media and better taken up by eukaryotic cells. However, their anchoring in hydrophobic cellular membranes and endosomes after endocytosis restricts their access to cellular nucleic acids. New methods of cellular delivery and the biological activity of the conjugates were studied. The cholesteryl residue was conjugated via disulfide bond to the 5' or 3' terminal phosphate group of two oligodeoxyribonucleotide dodecamers complementary to the mutated region of Ha-ras oncogene mRNA. The conjugates were able to form complementary duplexes with the mutated 27-b target fragment of mRNA but not with the wild-type sequence. Efficient sequence-specific RNase H cleavage of complementary mRNA was induced with low (< or = 500 nM) concentrations of the conjugates. At higher concentrations, this cleavage was progressively inhibited, probably due to an interaction between RNase H and the cholesterol residue. The hydrophobic conjugates could be adsorbed onto poly(isohexylcyanoacrylate) nanoparticles via their cholesteryl moieties and delivered to eukaryotic cells. Cholesterol-conjugated oligonucleotides were able to sequence-specifically inhibit the proliferation of T24 human bladder carcinoma cells in culture.

Rational design of point mutation-selective antisense DNA targeted to codon 12 of Ha-ras mRNA in human cells.

Antisense oligodeoxynucleotides targeted to Ha-ras mRNA have been designed to discriminate between the codon 12-mutated oncogene and the normal proto-oncogene. An in vitro assay using two different sources of RNase H (rabbit reticulocyte lysates and nuclear extract from HeLa cells) was used to characterize oligonucleotide binding to normal and mutated Ha-ras mRNA. Short oligonucleotides (12- or 13mers) centered on the mutation had a very high discriminatory efficiency. Longer oligonucleotides (16mers) did not discriminate efficiently between the mutated and the normal mRNA. We have tested the efficacy of dodecanucleotides to induce RNase H cleavage of the full-length mRNA, moving the target sequence from the loop to the stem region which is formed in the vicinity of mutated codon 12. The most selective oligonucleotides were centered on the mutation which is located near the junction between the loop and stem regions even though they were less efficient at inducing RNase H cleavage than those targeted to the loop region. The 12mer antisense oligonucleotide with the highest discriminatory power was selected for cell culture studies. This oligonucleotide inhibited the proliferation of a human cell line which had been transformed with the mutated Ha-ras gene (HBL100ras1) but had no effect on the parental cell line which was transfected with the vector DNA (HBL 100neo) and expressed only the normal Ha-ras gene. Growth inhibition of HBL100ras1 cells was associated with specific ablation of targeted Ha-ras mRNA as shown by RT-PCR. These results show that 'in vitro' evaluation using an RNase H assay allowed us to select an antisense oligonucleotide which elicited a selectivity towards point-mutated Ha-ras mRNA when added at 10 microM concentration to the culture medium of cells expressing wild type and mutated Ha-ras mRNA.

Photochemically and chemically activatable antisense oligonucleotides: comparison of their reactivities towards DNA and RNA targets.

Dodecadeoxyribonucleotides derivatized with 1,10-phenanthroline or psoralen were targeted to the point mutation (G<-->U) in codon 12 of the Ha-ras mRNA. DNA and RNA fragments, 27 nucleotides in length, and containing the complementary sequence of the 12mers, were used to compare the reactivity of the activatable dodecamers (cleavage of the target by the phenanthroline-12mer conjugates; photo-induced cross-linking of psoralen-12mer conjugates to the target). The reactivity of the RNA with the dodecamers was weaker than that of the DNA target. With psoralen-substituted oligonucleotides, it was possible to obtain complete discrimination between the mutated target (which contained a psoralen-reactive T(U) in the 12th codon) and the normal target (which contained G at the same position). When longer Ha-ras RNA fragments were used as targets (120 and 820 nucleotides), very little reactivity was observed. Part of the reactivity could be recovered by using 'helper' oligonucleotides that hybridized to adjacent sites on the substrate. A 'helper' chain length greater than 13 was required to improve the reactivity of dodecamers. However, the dodecanucleotides induced RNase H cleavage of the target RNA in the absence of 'helper' oligonucleotide. Therefore, in the absence of the RNase H enzyme, long oligonucleotides are needed to compete with the secondary structures of the mRNA. In contrast, formation of a ternary complex oligonucleotide-mRNA-RNase H led to RNAT cleavage with shorter oligonucleotides.

Hybridization specificity, enzymatic activity and biological (Ha-ras) activity of oligonucleotides containing 2,4-dideoxy-beta-D-erythro-hexopyranosyl nucleosides.

Antisense oligonucleotides with a 2,4-dideoxyhexopyranosyl nucleoside incorporated at the 3'-end and at a mutation site of the Ha-ras oncogene mRNA were synthesized. Melting temperature studies revealed that an A*-G mismatch is more stable than an A*-T mismatch with these hexopyranosyl nucleosides incorporated at the mutation site. The oligonucleotides are stable against enzymatic degradation. RNase H mediated cleavage studies revealed selective cleavage of mutated Ha-ras mRNA. The oligonucleotide containing two pyranose nucleosides at the penultimate position activates RNase H more strongly than natural oligonucleotides. No correlation, however, was found between DNA - DNA or RNA - DNA melting temperatures and RNase H mediated cleavage capacity. Although the A*-G mismatch gives more stable hybridization than the A*-T base pairing, only the oligonucleotides containing an A*-T base pair are recognized by RNase H. This modification is situated 3 base pairs upstream to the cleavage site. Finally, the double pyranose modified oligonucleotide was able to reduce the growth of T24 cells (bladder carcinoma) while the unmodified antisense oligonucleotide was not.

[Vitelliform dystrophy: study of 2 familial forms]. / Apport à l'étude de la dystrophie vitelliforme: étude de deux formes familiales.

The authors present seven cases of vitelliform macular dystrophy in two families. The cases comparison leads to oppose two different types: the classical type and the adult type with similar ophthalmoscopical and angiographical aspects but different genetical expressivity, evolution, and above all, different electrophysiological answer.