Evaluation of circulating miR-216a and miR-217 as biomarkers of pancreatic damage in the L-arginine-induced acute pancreatitis mouse model.

We investigated the usefulness of circulating miR-216a-5p and miR-217-5p that are pancreas-enriched micro RNAs (miRNAs) as biomarkers of acute pancreatic damage, and compared them with conventional pancreatic biomarkers in L-arginine-induced acute pancreatitis mouse model. As the results, amylase and lipase levels apparently increased and peaked on Day 3 when acute pancreatitis including acinar cell degeneration/necrosis and inflammatory cell infiltration reached its peak. In contrast, miR-216a-5p and miR-217-5p increased from Day 1 when histopathological findings in the acinar cells were limited to decreased zymogen granules, and the increases in ratios were much higher than those of amylase and lipase. The miRNAs remained at high levels until Day 5 when the pseudo-tubular complex and replacement of inflammatory cells and fibrotic cells were apparent instead of necrosis, whereas amylase and lipase levels decreased to the control levels. Furthermore, we examined the relationship between biomarker levels and histopathological degeneration/necrosis scores in the acinar cells. miR-216a-5p and miR-217-5p levels increased depending on the score of degeneration/necrosis, and all individual miRNAs exceeded the control levels from a score of 2 (focal necrosis), whereas all individual amylase and lipase levels exceeded the control levels at scores of 4 (lobular necrosis) and 3 (sublobular necrosis), respectively. In conclusion, we demonstrated that circulating miR-216a-5p and miR-217-5p could detect pancreatic damage earlier with greater magnitude, and the sensitivity to detect acinar cell degeneration/necrosis was superior to that of conventional biomarkers in the L-arginine-induced acute pancreatitis mouse model.

Preventing baker's asthma: an alternative strategy.

BACKGROUND: Although baker's asthma has attracted considerable research interest over the last 30 years, success in its prevention has been slow to achieve. This paper describes the results of an alternative preventive strategy, based on an observation that the excess of sensitization in bread bakers is largely due to IgE-mediated allergy to fungal amylase, contained in bread improvers. The practical application of the strategy has been to limit bread improver exposures to <1 mg/m3 [8 h time-weighted average (TWA)], whilst exposures to all other ingredients, including flour, have been limited to <10 mg/m3 (8 h TWA). METHOD: The paper describes the findings of in-house respiratory health surveillance and dust sampling programmes, from a UK food company whose primary interests are milling and baking, over the period following the introduction of the strategy to target the reduction in bread improver exposure. RESULTS: Over the 10 year period of surveillance, the incidence of symptomatic sensitization in the bread baking sector (2240 per million employees per annum) was greater than for the other flour-using groups (330 per million employees per annum), despite broadly similar total inhalable dust exposures. There was an overall reduction in the incidence of new cases of symptomatic sensitization, from 2085 per million employees per year in the first 5 years of the surveillance programme, to 405 per million employees per year in the subsequent 5 years. CONCLUSION: The strategy of targeting bread improver exposure is an effective approach for the prevention of new cases of symptomatic sensitization in bread bakeries.

The identification of the transcriptional regulator CRP in Aeromonas hydrophila JMP636 and its involvement in amylase production and the 'acidic toxicity' effect.

AIMS: The physiological examination of amylase production by Aeromonas hydrophila JMP636 and identification of the mechanism of regulation. METHODS AND RESULTS: Aeromonas hydrophila JMP636 was grown with single, then dual carbon sources; the growth cycle was followed and amylase activity throughout was monitored. The levels of cAMP, a known secondary messenger for the regulatory gene crp, were also examined. Amylase activity was regulated by catabolite repression. Physiological studies revealed that JMP636 exhibited both diauxic growth, with two carbon sources, and the 'acid toxicity' effect on glucose. The crp gene was cloned, expressed and inactivated from the JMP636 chromosome. Catabolite repression of amylase production and the 'acid toxicity' effect both require crp and were linked to cAMP levels. CONCLUSIONS: Regulation of amylase production was predicted to follow the model CRP-mediated cAMP-dependent Escherichia coli catabolite regulation system. SIGNIFICANCE AND IMPACT OF THE STUDY: This work provides an understanding of the physiology of the opportunistic pathogen Aer. hydrophila through identification of the mechanism of catabolite repression of amylase production and the existence of crp within this cell. It also provides a broader knowledge of global gene regulation and suggests regulatory mechanisms of other Aer. hydrophila gene/s.

Respiratory allergenicity of detergent enzymes in the guinea pig intratracheal test: association with sensitization of occupationally exposed individuals.

A guinea pig intratracheal test was used to set occupational operating guidelines for new enzyme proteins used in the detergent industry. In these studies, animals were intratracheally dosed with different levels of enzyme protein and sera from the animals were titered for allergic antibody to the enzyme. The amount of antibody produced to an enzyme was compared to the amount of antibody produced to the same protein doses of Alcalase, for which effective operating guidelines exist. These comparisons were used to determine if a new enzyme was more potent, less potent, or equivalent to Alcalase; operating guidelines were then established for the new enzyme. Termamyl was about 10-fold more potent than Alcalase and the protease subtilisin B was shown to be less potent. Another protease, Savinase, was shown to be equivalent in potency to Alcalase. The operating guidelines for Termamyl were adjusted lower, whereas the operating guidelines for the proteases were set the same as that of Alcalase. Under these conditions, we would predict that sensitizations to new enzymes would be comparable to or lower than the sensitizations to Alcalase. Prospective evaluation of skin prick test data of factory workers showed that sensitizations to Termamyl and Savinase were similar to sensitizations to Alcalase. The sensitizations to subtilisin B were lower than those to Alcalase. During this time period (7 years), only three respiratory incidents (rhinitis) were reported, demonstrating that employees with positive skin prick tests can continue to work. These comparisons indicate that the guinea pig intratracheal test is a good animal model for evaluating enzymes as respiratory allergens and that the data generated can be used to set operating guidelines for occupational allergens.

Subchronic toxicity studies in dogs and in utero-exposed rats fed diets containing Bacillus megaterium amylase derived from a recombinant DNA organism.

Subchronic toxicity studies were performed using a food-grade enzyme product from a recombinant Bacillus subtilis containing the B. megaterium amylase gene. Beagle dogs (four/sex/group) and Fischer 344 rats (25/sex/group) were fed diets containing 0, 20, 60 or 100 units amylase/g food. The dogs received treated diets for 13 wk. The parental (F0) rats received treated diets for 4 wk before breeding and through weaning of the F1 pups; 25 F1 rats/sex/group received treated diets for at least 13 wk (from weaning until necropsy). All animals appeared healthy throughout the studies. Treated animals had sporadic significant differences in body weight and food consumption values when compared with those of controls, but they were not considered toxicologically meaningful. There were no treatment-related effects on reproduction indices, growth variables or litter data in rats. There were no changes in clinical pathology values, organ weights or macroscopic and microscopic observations that were related to treatment. Based on the results of this study, the no-observable-effect level for this amylase fed to dogs or rats is no less than 100 units/g food. This is 6000-12,700 times the predicted human use level.