Monocytes and macrophages express a glycosyl phosphatidylinositol (GPI)-anchored lipopolysaccharide (LPS) receptor on the cell surface which enables them to detect minute amounts of LPS released from Gram-negative bacteria. A soluble form of CD14 is also found free in serum, though its physiological function is unknown. the interaction of LPS with CD14 on the monocyte surface leads to an activation of the cells which is manifested in the sudden release of reactive oxygen species, a process referred to as an oxidative burst. In patients suffering from the condition known as paroxysmal nocturnal haemoglobinuria (PNH), the synthesis of GPI anchors is blocked in haematopoietic cells which are therefore unable to express GPI-linked proteins on their surface. In severe cases, over 90% of monocytes lack membrane-bound CD14, though normal levels of the soluble form of the receptor-sCD14-are found in the serum. Despite this lack of membrane-bound CD14, monocytes from PNH patients can respond to low concentrations of LPS. Here we show that the LPS-induced oxidative burst of these PNH monocytes requires a component present in serum. The serum-dependent activation can be inhibited by monoclonal antibodies to CD14, can be removed from the serum by passage over a matrix to which an anti-CD14 antibody has been bound, and the depleted serum can be reconstituted by the addition of either purified natural or purified recombinant soluble CD14. We conclude that an LPS-dependent oxidative burst in PNH monocytes can be mediated by soluble CD14.

Acute-Phase Proteins↗

PubMedDate not supplied

[Azathioprine ingestion with suicidal intent by an adolescent with chronic juvenile polyarthritis].

We report on a 13 years 7 months old boy who ingested 650 mg azathioprine in a suicide attempt. His baseline medication was azathioprine and methotrexate for control of juvenile chronic polyarthritis. After the induction of vomiting by ipecacuanha sirup and administration of charcoal (1 g/kg), he was closely followed for haematological, hepatic, and renal side effects. During the following days, no serious adverse events were noted except that the thrombocyte (from 403,000 down to 199,000/microliter) and total leukocyte count decreased moderately (from 12,000 down to 7100/microliter). On the basis of this case report and the available literature, the potential acute toxicity of azathioprine and possible treatment modalities are discussed.

Adolescent↗

PubMedDate not supplied

Development of a completely encapsulated intraocular pressure sensor.

A completely encapsulated intraocular pressure (IOP) sensor equipped with telemetric signal and energy transfer is introduced integrated into a silicone disc for implantation into the eye. After implantation into enucleated pig eyes and into rabbit eyes in vivo, the IOP was recorded and compared to established techniques of IOP measurement. Pressure chamber tests showed that the sensor functioned correctly after biocompatible encapsulation in polydimethylsiloxane. In vivo and in vitro tests in rabbit and pig eyes demonstrated that the implanted system worked with the same precision as established techniques for IOP determination. The correlation between the measurements with the implanted device and pneumotonometry in several experiments was between 0.9 and 0.99. This device serves as a functioning model for the realization of a telemetric IOP sensor for integration into an artificial intraocular lens. Such a device will open new perspectives, not only in the management of glaucoma, but also in basic research for mechanisms of glaucoma.

Animals↗

PubMedDate not supplied

The effects of egg-derived antibodies to glucosyltransferases on dental caries in rats.

The role of Streptococcus mutans in the development of dental caries is well recognized. Important virulence factors include the glucosyltransferases (gtf), essential for production of glucans. We evaluated the anticariogenic effects of orally administered chicken anti-cell-associated (CA) Gtf antibodies in desalivated rats. The animals were infected with S. mutans MT8148R and treated with chicken anti-CA-Gtf egg yolk antibodies (IgY) or nonimmune egg yolk powder. Smooth surface lesions were significantly lower in the anti-CA-Gtf-treated group in comparison to the control groups. Sulcal surface caries was also decreased and of less severity. Our study suggests that chicken anti-CA-Gtf antibodies may have promise as a prophylaxis for high caries risk patients.

Analysis of Variance↗