Comparative effects of tetrandrine and berbamine on subcutaneous air pouch inflammation induced by interleukin-1, tumour necrosis factor and platelet-activating factor

The effects of the bisbenzylisoquinoline alkaloids tetrandrine and berbamine on the action of IL-1, TNF and PAF were investigated in the rat subcutaneous air pouch model of inflammation. Both compounds were equipotent in the suppression of leukocyte infiltration into air pouches induced by IL-1 and TNF, with ED₅₀ values in the range 20–30 mg/kg/3 days. Both were also equiptent in suppression of PMN infiltration induced by PAF with ED₅₀ values in the same range as that for IL-1 and TNF. However, tetrandrine was more potent than berbamine as a suppressant of PAF-induced MNC infiltration, but much less potent than berbamine in carageenen-induced PMN infiltration. These results suggest that these bisbenzylisoquinolines may have value in the therapy of chronic inflammatory diseases where IL-1, TNF and PAF have a role in pathogenesis.     

Effect of twenty-three chemotherapeutic agents on the adherence and growth of Giardia lamblia in vitro

The sensitivity of Giardia lamblia to 23 chemotherapeutic agents was evaluated in vitro with a Growth Inhibition Assay and a recently developed Adherence Inhibition Assay. Of the four established anti-giardia drugs, tinidazole, metronidazole, and furazolidone were found to have strong inhibitory effects on both growth and adherence, while mepacrine had a strong effect on growth only. Three drugs (mefloquine, doxycycline and rifampin) not previously used in giardiasis were found to have significant activity in vitro and may deserve consideration for clinical evaluation of efficacy. Also, the concurrent use of these two in vitro methods provided significant insights into the modes of action of some of these drugs on G. lamblia.     

Identification of cathepsin C mutations in ethnically diverse papillon-Lefèvre syndrome patients

INTRODUCTION—Papillon-Lefèvre syndrome (PLS) is an autosomal recessive disorder characterised by palmoplantar keratoderma and severe, early onset periodontitis, which results from deficiency of cathepsin C activity secondary to mutations in the cathepsin C gene. To date, 13 different cathepsin C mutations have been reported in PLS patients, all of which are homozygous for a given mutation, reflecting consanguinity.
AIM—To evaluate the generality of cathepsin C mutations in PLS, we studied an ethnically diverse group of 20 unrelated families.
METHODS—Mutations were identified by direct automated sequencing of genomic DNA amplified for exonic regions and associated splice site junctions of the cathepsin C gene. Long range PCR was performed to determine the genomic structure of the cathepsin C gene.
RESULTS—The cathepsin C gene spans over 46 kb, with six introns ranging in size from 1.6 to 22.4 kb. Eleven novel mutations and four previously reported mutations were identified in affected subjects from 14 families. Missense mutations were most common (9/15), followed by nonsense mutations (3/15), insertions (2/15), and deletions (1/15). Among these 14 probands, two were compound heterozygotes. Affected subjects with transgressions of the dermal lesions onto the knees or elbows or both had mutations in both the pro- and mature regions of the enzyme, although most were in the mature region.
CONCLUSION—Mutations in the mature region of cathepsin C were more likely to be associated with the transgressions of the dermatological lesions, although the results were not statistically significant. A comprehensive list of all cathepsin C mutations described to date, representing 25 mutations from 32 families with PLS and related conditions, is also presented.


Keywords: cathepsin C; genetics; severe early onset periodontitis; hyperkeratosis     

A phage-displayed single chain variable fragment that interacts with hepatitis B core antigen: library construction, selection and diagnosis.

BACKGROUND: Phage display is an alternative method for constructing and selecting antibodies with desired specificity towards an antigen. OBJECTIVES: To construct a library of single chain variable fragment (ScFv) towards hepatitis B core antigen (HBcAg). To isolate a ScFv phage clone that interacts with HBcAg and to develop a phage-ELISA for detecting the antigen. STUDY DESIGN: Mice were inoculated with HBcAg and RNA was extracted from their spleen cells. The genes encoding heavy (V(H)) and light (V(L)) chains were amplified, linked via PCR and cloned into a phagemid vector. Phage particles displaying ScFv were panned against HBcAg and a selected clone was characterized and employed as a diagnostic reagent for detecting HBcAg in serum samples. RESULTS: A phage clone that interacts with HBcAg was selected from the antibody library. The binding of the phage to HBcAg was inhibited by a cyclic peptide bearing the WSFFSNI sequence. A phage-ELISA was established using the recombinant phage and as low as 10ng of HBcAg can be detected by the assay. CONCLUSION: The ScFv displayed on the surface of filamentous phage is an alternative choice for diagnosis of HBcAg in serum samples.     

Lymphocyte-neutrophil interactions: opposite effects of interleukin-2 and tumour necrosis factor-beta (lymphotoxin) on human neutrophil adherence

Human neutrophil adherence was enhanced by recombinant human tumour necrosis factor-beta (TNF beta) but suppressed by recombinant human interleukin-2 (IL-2). The opposite effects of these two lymphokines were observed over a range of concentrations consistent with their other biological activities, occurred within 15 min of incubation, and were still evident after 60 min. Pretreatment of neutrophils with both IL-2 and TNF beta resulted in adherence values intermediate between the values obtained with the individual lymphokines. IL-2 suppressed the stimulatory effects of both the chemotactic peptide formyl-methionyl-leucyl-phenyl-alanine (FMLP) and the phorbol ester phorbol myristate acetate (PMA). The combination of TNF beta with either FMLP or PMA produced enhancement of neutrophil adherence which exceeded that of either agent alone. These effects of the lymphokines were not due to endotoxin contamination since their effects were sensitive to heating and insensitive to polymyxin B treatment. These experiments provide further evidence for the critical role of these lymphokines in the regulation of acute and chronic inflammatory processes.     

Bruceine B, A Potent Inhibitor of Leukocyte-Endothelial Cell Adhesion

Leukocyte adhesion to vascular endothelial cells is an essential step in the development of inflammatory diseases. We have searched for inhibitors of leukocyte-endothelial cell adhesion that could be used as anti-inflammatory drugs and found that bruceine B (0.2 g/ml; 0.44 M) inhibited human neutrophil or T cell adhesion to tumor necrosis factor- (TNF) stimulated human umbilical vein endothelial cells (HUVEC). The inhibition of neutrophil adhesion to TNF-stimulated HUVEC by bruceine B was not derived from cytotoxic effects, as determined by measurement of the level of lactate dehydrogenase (LDH) activity in conditioned medium. The effect of bruceine B on neutrophil adhesion to HUVEC was not seen when the neutrophils were preincubated with bruceine B. However, inhibitory effects were evident when the HUVEC were preincubated with bruceine B. Bruceine B also inhibited neutrophil adhesion to lipopolysaccharide-stimulated HUVEC and T cell adhesion to TNF-stimulated HUVEC. These findings suggest that bruceine B may have anti-inflammatory activity.     

Lack of increase in time to blood culture positivity in a patient with persistent methicillin-resistant Staphylococcus aureus bacteremia predicts failure of antimicrobial therapy

Time to positivity is an available parameter in automated blood culture systems. We report a patient with persistent methicillin-resistant Staphylococcus aureus bacteremia who received various regimens for treatment of methicillin-resistant S. aureus, and demonstrate that monitoring of the time to positive blood culture might be helpful in the early recognition of treatment failure.