[Paul Sudeck--his contribution to anesthesia]. / Paul Sudeck--Sein Beitrag zur Anaesthesie.

Paul Sudeck is not generally recognised as a pioneer in anaesthesia, although he is well known for the atrophy of bone named after him. However, he not only championed the use of ether as a safe anaesthetic agent, described a method of ether analgesia for outpatient surgery and devised an inhaler for its administration, but also reintroduced nitrous oxide into Germany and invented possibly the first circle carbon dioxide absorption system with an optional attachment for continuous positive pressure respiration useful for the performance of thoracotomies.

Discovery and evaluation of potent, tyrosine-based alpha4beta1 integrin antagonists.

Using disulphide cysteine-based inhibitors as lead structures, this communication describes our strategy for identifying more stable, potent antagonists of the alpha4beta1 integrin. These studies ultimately discovered potent, low molecular weight inhibitors based on D-thioproline-L-tyrosine.

CDP840: a novel inhibitor of PDE-4.

We present the in vitro characterization of a novel phosphodiesterase type 4 inhibitor, CDP840 (R-[+]-4-[2-¿3-cyclopentyloxy-4-methoxyphenyl¿-2-phenylethyl]pyridine), which has shown efficacy in a phase II allergen challenge study in asthmatics without adverse effects. CDP840 potently inhibits PDE-4 isoenzymes (IC50 2-30 nM) without any effect on PDE-1, 2, 3, 5, and 7 (IC50 > 100 microM). It exhibited no significant selectivity in inhibiting human recombinant isoenzymes PDE-4A, B, C or D and was equally active against the isoenzymes lacking UCR1 (PDE-4B2 and PDE-4D2). In contrast to rolipram, CDP840 acted as a simple competitive inhibitor of all PDE-4 isoenzymes. Studies with rolipram indicated a heterogeneity within all the preparations of PDE-4 isoenzymes, indicative of rolipram inhibiting the catalytic activity of PDE-4 with both a low or high affinity. These observations were confirmed by the use of a PDE-4A variant, PDE-4A330-886, which rolipram inhibited with low affinity (IC50 = 1022 nM). CDP840 in contrast inhibited this PDE-4A variant with similar potency (IC50 = 3.9 nM), which was in good agreement with the Kd of 4.8 nM obtained from [3H]-CDP840 binding studies. Both CDP840 and rolipram inhibited the high-affinity binding of [3H]-rolipram binding to PDE-4A, B, C, and D with similar Kd app (7-19 nM and 3-5 nM, respectively). Thus, the activity of CDP840 at the [3H]-rolipram binding site was in agreement with the inhibitor's activity at the catalytic site. However, rolipram was approximately 100-fold more potent than CDP840 at inhibiting the binding of [3H]-rolipram to mouse brain in vivo. These data clearly demonstrate that CDP840 is a potent selective inhibitor of all PDE-4 isoenzymes. In contrast to rolipram, CDP840 was well-tolerated in humans. This difference, however, cannot at present be attributed to either isoenzyme selectivity or lack of activity in vitro at the high-affinity rolipram binding site (Sr).

The in vivo and in vitro characterisation of an engineered human antibody to E-selectin.

BACKGROUND: E-selectin is an endothelial cell specific adhesion molecule that is believed to play an important role in the early stages of leukocyte extravasation. OBJECTIVES: Here we describe the construction and evaluation of an engineered human monoclonal antibody that blocks E-selectin function. RESULTS: SPLAT-1 is an engineered human monoclonal antibody that has a very similar affinity for E-selectin as its murine parent antibody. In vitro SPLAT-1 blocks the binding of human leukocytes to E-selectin and does not mediate antibody-dependent cellular cytotoxicity (ADCC) or complement-mediated lysis of endothelial cells. In vivo, SPLAT-1 inhibits the recruitment of leukocytes to cytokine-inflamed human skin grafted on to SCID mice and has a long circulating half-life in primates. It does not appear to provoke an immune response in primates even on repeat administration. CONCLUSIONS: SPLAT-1 has the characteristics of a antibody suitable for human therapy studies.

The inhibition of antigen-induced eosinophilia and bronchoconstriction by CDP840, a novel stereo-selective inhibitor of phosphodiesterase type 4.

1. The novel tri-aryl ethane CDP840, is a potent and selective inhibitor of cyclic AMP phosphodiesterase type 4 (PDE 4) extracted from tissues or recombinant PDE 4 isoforms expressed in yeast (IC50S: 4-45 nM). CDP840 is stereo-selective since its S enantiomer (CT 1731) is 10-50 times less active against all forms of PDE 4 tested while both enantiomers are inactive (IC50S: > 100 microM) against PDE types 1, 2, 3 and 5. 2. Oral administration of CDP840 caused a dose-dependent reduction of interleukin-5 (IL-5)-induced pleural eosinophilia in rats (ED50 = 0.03 mg kg-1). The eosinophils in pleural exudates from CDP840-treated animals contained higher levels of eosinophil peroxidase (EPO) than cells from control animals, suggesting a stabilizing effect on eosinophil degranulation. CDP840 was approximately equi-active with the steroid dexamethasone in this model and was 10-100 times more potent than the known PDE 4-selective inhibitors rolipram and RP73401. The activity of CDP840 was not influenced by adrenalectomy, beta-sympathomimetics or beta-sympatholytics. 3. Antigen-induced pulmonary eosinophilia in sensitized guinea-pigs was reduced dose-dependently by CDP840 (0.01-1 mg kg-1, i.p.) and intracellular EPO levels were significantly higher. CDP840 was more potent in these activities than CT1731 or rolipram and comparable in potency to RP73401. 4. Rolipram or CDP840 were less active than dexamethasone in preventing neutrophil accumulation, or exudate formation in carrageenan-induced pleurisy in rats and thus do not exhibit general anti-inflammatory activity. 5. In sensitized guinea-pigs, aerosols of the antigen ovalbumin caused a dose-dependent bronchoconstriction demonstrated by an increase in pulmonary inflation pressure. Administration of CDP840 (0.001-1.0 mg kg-1, i.p.), 1 h before antigen challenge, resulted in dose-dependent reduction in response to antigen. This activity was not due to bronchodilatation since higher doses of CDP840 (3 mg kg-1) did not significantly change the bronchoconstrictor response to histamine. Rolipram was approximately 10 times less active than CDP840 in preventing antigen-induced bronchoconstriction. 6. These results confirm the observations that selective PDE 4 inhibitors reduce antigen-induced bronchoconstriction and pulmonary eosinophilic inflammation. CDP840 is more potent than rolipram in inhibiting native or recombinant PDE 4. Unlike the recently described potent PDE 4 inhibitor RP73401, CDP840 is more active than rolipram in the rat IL-5 model following oral administration. The novel series of tri-aryl ethanes, of which CDP840 is the lead compound, could be the basis of an orally active prophylactic treatment for human asthma.

The in vivo and in vitro effects of antibodies against rabbit beta 2-integrins.

Beta 2-integrins play a crucial role in the development of an inflammatory response. In ours study, Abs have been used to investigate the role of individual members of this family of adhesion molecules in both in vivo and in vitro assays. An Ab against rabbit LFA-1 effectively inhibited the adhesion of rabbit polymorphonuclear leukocytes to rabbit endothelial cells in culture and was also effective in blocking cell recruitment to the peritoneum and vascular leakage at dermal sites of inflammation. An Ab that inhibited rabbit complement receptor type 3 function in vitro failed to inhibit cell recruitment to the peritoneum or vascular leakage in response to intradermal FMLP. Histologic studies suggested that the anti-complement receptor type 3 Ab may have modified the cell migration process.

Autoantibody to heat-shock protein 90 can mediate protection against systemic candidosis.

Epitope mapping shows that patients recovering from systemic infection with Candida albicans produce antibodies against both fungal-specific and conserved epitopes of the heat-shock protein (hsp) 90. In a mouse model of systemic candidosis, mortality was halved by prior administration of sera from two infected patients containing antibodies to hsp 90. One of these patients had no other candidal antibodies detectable on immunoblotting. The protective effect was mediated by the immunoglobulin fraction of the immune serum. It was not observed with a normal human serum. A mouse monoclonal antibody raised against one of the conserved peptide epitopes suggested that an autoantibody to hsp 90 could mediate protection against systemic candidosis in the animal model.

The protective effects of cell-free fluid exudate on cartilage degradation in vitro.

In a short-term culture system, polymorphonuclear neutrophils (PMNs) were shown to cause significant loss of glycosaminoglycan (GAG) from cartilage. In addition, a lysate of these cells, and in particular cells stimulated with a phorbol ester, greatly enhanced this loss of GAG. This loss could be partially or completely inhibited by the addition of cell-free fluid exudate to the system. In other long-term culture experiments, IL-1a was shown to enhance fibroblast-induced GAG loss from cartilage. In this system too the breakdown was inhibited by cell-free fluid exudate. Initial characterization of the protective agent or agents shows them to be heat-stable at 56 degrees C and to be non-dialysable. It is proposed that in the chronic inflammatory joint disease, rheumatoid arthritis, the fluid phase of an inflammatory response may have a protective effect against the underlying pathological processes.

The synergism between platelet-activating factor and interleukin-1 on cartilage breakdown.

The breakdown of rat articular cartilage has been studied in vivo and in vitro to observe the effect of platelet-activating factor (PAF) and interleukin-1 alpha (IL-1 alpha) on the net loss of glycosaminoglycan (GAG). When PAF was infused over a 2-week period into rats, there was no increased breakdown of implanted, cotton-wrapped, femoral head cartilage. However, there was a loss of proteoglycan from the femoral head cartilage of the recipient rats (native cartilage). This loss from the native cartilage was not apparent if the animal had not been implanted with cartilage. Using an in vitro system, the effect of PAF and IL-1 alpha on rat femoral head cartilage was further examined. Separately, neither agent had any significant effect on GAG content. However, when combined, there was a significant loss of GAG. The significance of these results is discussed.

Paul Sudeck--his contribution to anaesthesia.

Paul Sudeck is not generally recognized as a pioneer in anaesthesia, although he is well known for the atrophy of bone named after him. However, he not only championed the use of ether as a safe anaesthetic agent, described a method of ether analgesia for outpatient surgery and devised an inhaler for its administration, but also reintroduced nitrous oxide into Germany and invented possibly the first circle carbon dioxide absorption system with an optional attachment for continuous positive pressure respiration.

An investigation into the possible involvement of platelet activating factor in experimental allergic encephalomyelitis in rats.

Rats developing experimental allergic encephalomyelitis have been treated with intra-venous injections of Platelet-Activating Factor on days 5, 6 and 7 post adjuvant injection. Other rats have been treated with one of two different PAF antagonists or vehicle. The animals injected with PAF on day 5 post adjuvant developed a more severe form of the disease at an earlier time point than did control animals. Animals treated with the PAF antagonists did not develop the disease to any great extent. Treatment with the vehicle had no effect compared to control. These results implicate PAF in the aetiology of this model of multiple sclerosis and may suggest a role for PAF antagonists in the treatment of this disease.

The effect of indomethacin on cartilage breakdown.

The effects of recombinant interleukin-1 alpha (rIL-1 alpha) and indomethacin on the glycosaminoglycan (GAG) content of rat femoral head cartilage (FHC) were studied in vitro. Net GAG loss was observed from cartilage cultured in the presence of indomethacin plus rIL-1 alpha. Indomethacin and rIL-1 alpha alone caused no net loss of GAG from cartilage unless the cartilage was cultured in the presence of fibroblasts.