Interaction with telencephalin and the amyloid precursor protein predicts a ring structure for presenilins.

The carboxyl terminus of presenilin 1 and 2 (PS1 and PS2) binds to the neuron-specific cell adhesion molecule telencephalin (TLN) in the brain. PS1 deficiency results in the abnormal accumulation of TLN in a yet unidentified intracellular compartment. The first transmembrane domain and carboxyl terminus of PS1 form a binding pocket with the transmembrane domain of TLN. Remarkably, APP binds to the same regions via part of its transmembrane domain encompassing the critical residues mutated in familial Alzheimer's disease. Our data surprisingly indicate a spatial dissociation between the binding site and the proposed catalytic site near the critical aspartates in PSs. They provide important experimental evidence to support a ring structure model for PS.

Modulation of human interferon-gamma biosynthesis by antisense oligodeoxynucleotides.

We investigated the inhibition of human interferon-gamma (HuIFN-gamma) production in cultures of lymphocytes with the use of the antisense strategy. Out of a series of antisense oligodeoxynucleotides (ODN) complementary to different regions of the HuIFN-gamma gene, a 16-mer specific for a sequence including the translation initiation codon was the most effective. Here we describe a detailed protocol for the isolation of lymphocytes from buffy coats, the rational design of antisense ODN, and the monitoring of HuIFN-gamma production of the antisense ODN-treated cells.

Inhibition of human interferon-gamma biosynthesis by an antisense RNA-expressing vector.

We applied antisense RNA technology for reducing the level of human IFN-gamma (HuIFN-gamma) expression. An antisense RNA vector containing the full-length HuIFN-gamma cDNA in the opposite orientation was electroporated into cells constitutively producing very high levels of the cytokine. Approximately 53% of the resulting clones exhibited a specific HuIFN-gamma inhibition of an average of 95.5%. The results of reverse transcription-polymerase chain reaction and Northern blot analyses revealed that the antisense effect originated from a specific reduction of the targeted mRNA caused by antisense RNA expression. This very effective antisense RNA strategy can have possible therapeutic applications in treating diseases where HuIFN-gamma is known to play a negative role, such as in certain autoimmune diseases.

Inhibition of human interferon-gamma expression by antisense oligodeoxynucleotides.

We investigated 12 antisense oligodeoxynucleotides, complementary to different regions of the human interferon-gamma (HuIFN-gamma) gene, for their ability to inhibit HuIFN-gamma production in cultures of single donor total leukocytes or lymphocytes (95% purity). Out of seven oligomers, specific for a sequence including the translation initiation codon, 15 to 21 nucleotides long, the one resulting in the greatest inhibition was the 16-mer. An inhibitory effect of 90% could be achieved when the oligomer was added to cultures of lymphocytes in separate doses. Three other 16-mers, complementary to a sequence in the 5' noncoding region, in the coding region, or at the donor splice junction of the third intron respectively, were inhibitory to a lesser extent. Two 16-mers, one complementary to a sequence at the donor splice junction of the second intron and one specific for a sequence in the 3' untranslated region, showed no effect.

Formocresol pulpotomy in primary molars: a long-term radiographic evaluation.

Of 137 pulpotomies with Tempophore, 13 percent failed. In comparison with pulpotomies using Ca(OH)2, in which higher failure rates occurred (Magnusson, Schröder), we can conclude that the pulpotomy with Tempophore, as well as with Buckley's formocresol, can be considered a clinically successful therapy. These therapies permit the preservation of even extensively carious primary molars, until their normal exfoliation time. The preservation of these teeth prevents the appearance of functional as well as orthodontic problems, because the arch-length is not adversely affected. The mesial tipping or drifting of the permanent molars is, furthermore, prevented.

[Radiographic follow-up of primary molars following sclerosing amputation]. / Radiografische kontrole van melkmolaren na scleroserende amputatie.

The effects of pulpotomy with the formocresol technique (Tempophore) were studied in a sample of 72 patients between 3 and 9 years of age. A total of 137 primary molars were treated and a longitudinal radiographical follow-up was executed with an interval of 4 months. Eighteen pulpotomies (13%) failed; in twelve of them an interradicular abscess was developing and 6 of them failed by internal resorption. It was striking that a rather great number of the failures occurred under 3 years of age and in patients older than 9 years. A second remarkable result was the higher frequency of failures in the mandible (18%) than in the maxilla (4%). This study reveals that the pulpotomy by formocresol is a successful therapy, by which primary molars with extensive carious lesions can be preserved until their usual time of shedding.