Effect of plant neutrophil elastase inhibitor on leucocyte migration, adhesion and cytokine release in inflammatory conditions

BACKGROUND AND PURPOSE

The serine and cysteine peptidase inhibitor, BbCI, isolated from Bauhinia bauhinioides seeds, is similar to the classical plant Kunitz inhibitor, STI, but lacks disulphide bridges and methionine residues. BbCI blocks activity of the serine peptidases, elastase (K_iapp 5.3 nM) and cathepsin G (K_iapp 160.0 nM), and the cysteine peptidase cathepsin L (K_iapp 0.2 nM). These three peptidases play important roles in the inflammatory process.

EXPERIMENTAL APPROACH

We measured the effects of BbCI on paw oedema and on leucocyte accumulation in pleurisy, both induced by carrageenan. Leucocyte–endothelial cell interactions in scrotal microvasculature in Wistar rats were investigated using intravital microscopy. Cytokine levels in pleural exudate and serum were measured by elisa.

KEY RESULTS

Pretreatment of the animals with BbCI (2.5 mg·kg⁻¹), 30 min before carrageenan-induced inflammation, effectively reduced paw oedema and bradykinin release, neutrophil migration into the pleural cavity. The number of rolling, adhered and migrated leucocytes at the spermatic fascia microcirculation following carrageenan injection into the scrotum were reduced by BbCI pretreatment. Furthermore, levels of the rat chemokine cytokine-induced neutrophil chemo-attractant-1 were significantly reduced in both pleural exudates and serum from animals pretreated with BbCI. Levels of interleukin-1β or tumour necrosis factor-α, however, did not change.

CONCLUSIONS AND IMPLICATIONS

Taken together, our data suggest that the anti-inflammatory properties of BbCI may be useful in investigations of other pathological processes in which human neutrophil elastase, cathepsin G and cathepsin L play important roles.     

The appropriateness of surveillance colonoscopy intervals after polypectomy

BACKGROUND:

Adherence to surveillance colonoscopy guidelines is important to prevent colorectal cancer (CRC) and unnecessary workload.

OBJECTIVE:

To evaluate how well Canadian gastroenterologists adhere to colonoscopy surveillance guidelines after adenoma removal or treatment for CRC.

METHODS:

Patients with a history of adenomas or CRC who had surveillance performed between October 2008 and October 2010 were retrospectively included. Time intervals between index colonoscopy and surveillance were compared with the 2008 guideline recommendations of the American Gastroenterological Association and regarded as appropriate when the surveillance interval was within six months of the recommended time interval.

RESULTS:

A total of 265 patients were included (52% men; mean age 58 years). Among patients with a normal index colonoscopy (n=110), 42% received surveillance on time, 38% too early (median difference = 1.2 years too early) and 20% too late (median difference = 1.0 year too late). Among patients with nonadvanced adenomas at index (n=96), 25% underwent surveillance on time, 61% too early (median difference = 1.85) and 14% too late (median difference = 1.1). Among patients with advanced neoplasia at index (n=59), 29% underwent surveillance on time, 34% too early (median difference = 1.86) and 37% later than recommended (median difference = 1.61). No significant difference in adenoma detection rates was observed when too early surveillance versus appropriate surveillance (34% versus 33%; P=0.92) and too late surveillance versus appropriate surveillance (21% versus 33%; P=0.11) were compared.

CONCLUSION:

Only a minority of surveillance colonoscopies were performed according to guideline recommendations. Deviation from the guidelines did not improve the adenoma detection rate. Interventions aimed at improving adherence to surveillance guidelines are needed.     

RAW TROPICAL OYSTERS AS VEHICLES FOR MULTIDRUG-RESISTANT Vibrio parahaemolyticus

The following study aimed to determine the antimicrobial susceptibility profile of Vibrio parahaemolyticus strains from fresh and frozen oysters Crassostrea rhizophorae sold in Fortaleza-Brazil. An antibiogram was performed on 87 isolates using nine antibiotics: gentamicin (Gen 10 µg), ampicillin (Amp 10 µg), penicillin G (Pen 10U), ciprofloxacin (Cip 5 µg), chloramphenicol (Chl 30 µg), nalidixic acid (Nal 30 µg), tetracycline (Tet 30 µg), vancomycin (Van 30 µg) and erythromycin (Ery 15 µg). All strains were resistant to at least one antibiotic, and 85 (97.7%) were multi-resistant, with predominance of the Van+ Pen+Amp resistance profile (n = 46). Plasmid resistance to Pen, Amp and Ery was detected. Thus, the risk that raw oyster consumption poses to the health of consumers is highlighted, due to the fact that these bivalves may host antibacterial-resistant microorganisms.     

Parents, physicians, and antibiotic use

BACKGROUND: Emergence of resistant bacterial pathogens has increased concerns about antibiotic prescribing patterns. Parent expectations and pressure may influence these patterns. OBJECTIVE: To understand how parents influence the prescribing patterns of physicians and what strategies physicians believe are important if we are going to reduce inappropriate use of oral antimicrobial agents. DESIGNS AND METHODS: One thousand pediatricians who are members of the American Academy of Pediatrics were asked to complete a semi-structured questionnaire. The physicians were chosen randomly by the American Academy of Pediatrics. RESULTS: Nine hundred fifteen pediatricians were eligible and 610 surveys were analyzable, for a response rate of 67%. The majority of respondents were male (56%), worked in a group practice (51%), saw an average of 114 patients per week and were in practice for 14 years. Forty percent of the pediatricians indicated that 10 or more times in the past month a parent had requested an antibiotic when the physician did not feel it was indicated. Forty-eight percent reported that parents always, most of the time, or often pressure them to prescribe antibiotics when their children are ill but antibiotics are not indicated. In follow-up questions, approximately one-third of physicians reported they occasionally or more frequently comply with these requests. Seventy-eight percent felt that educating parents would be the single most important program for reducing inappropriate oral antibiotic use and 54% indicated that parental pressure, in contrast to concerns about legal liability (12%) or need to be efficient in practice (19%), contributed most to inappropriate use of oral antibiotics. CONCLUSIONS: Pediatricians acknowledge prescribing antimicrobial agents when they are not indicated. Pediatricians believe educating parents is necessary to promote the judicious use of antimicrobial agents.     

HELICOBACTER PYLORI-SPECIFIC TUMOUR-INFILTRATING T CELLS PROVIDE CONTACT DEPENDENT HELP FOR THE GROWTH OF MALIGNANT B CELLS IN LOW-GRADE GASTRIC LYMPHOMA OF MUCOSA-ASSOCIATED LYMPHOID TISSUE

Previous studies have shown that tumour cells from low-grade B-cell gastric lymphomas of mucosa-associated lymphoid tissue (MALT) type proliferate in vitro in response to heat-killed whole cell preparations of Helicobacter pylori , but only in the presence of tumour-infiltrating T cells. This response is strain-specific in that the tumours studied responded optimally to different strains of H. pylori . It was unclear from these studies, however, whether the ability to recognize the specific stimulating strains of H. pylori was a property of the tumour cells or the tumour-infiltrating T cells. This study shows that whereas the tumour cells do not respond to H. pylori , both freshly isolated tumour-infiltrating T cells and a T cell line derived from these cells proliferate in response to stimulating strains of H. pylori . T cells from the spleen of one of the patients do not share this property. These results suggest that B-cell proliferation in cases of low-grade gastric lymphoma of MALT type in vitro in response to H. pylori is due to recognition of H. pylori by tumour-infiltrating T cells, which in turn provide help for tumour cell proliferation. The observations provide an explanation for properties of gastric MALT-type lymphoma, such as regression following eradication of H. pylori and the tendency of the tumour to remain localized to the primary site.