Tissue engineered indigenous pericardial patch urethroplasty: A promising solution to a nagging problem

Objective

Urethral stricture is a highly prevalent disease and has a continued rising incidence. The global burden of disease keeps rising as there are significant rates of recurrence with the existing management options with the need for additional repeat procedures. Moreover, the existing treatment options are associated with significant morbidity in the patient. Long segment urethral strictures are most commonly managed by augmentation urethroplasty. We explored the potential for the application of an acellular tissue engineered bovine pericardial patch in augmentation urethroplasty in a series of our patients suffering from urethral stricture disease. The decreased morbidity due to the avoidance of harvest of buccal mucosa, decreased operative time and satisfactory postoperative results make it a promising option for augmentation urethroplasty.

Methods

Nine patients with long segment anterior urethral strictures (involving penile and/or bulbar urethra and stricture length >4 cm) were included in the study after proper informed consent was obtained. Acellular tissue engineered indigenous bovine pericardial patch was used for urethroplasty using dorsal onlay technique.

Results

A total of nine patients underwent tissue engineered indigenous pericardial patch urethroplasty for long segment urethral strictures, mostly catheter injury induced or associated with balanitis xerotica obliterans. Median follow-up was 8 months (range: 2–12 months). Out of nine patients, eight (88.9%) were classified as success and one (11.1%) was classified as failure.

Conclusion

Our study brings a product of tissue engineering, already being used in the cardiovascular surgery domain, into the urological surgery operating room with satisfactory results achieved using standard operating techniques of one stage urethroplasty.

Potential application of the nisin Z preparation of Lactococcus lactis W8 in preservation of milk

AIMS

The aim of the study is to evaluate the effectiveness of the preparation of nisin Z from Lactococcus lactis W8-fermented milk in controlling the growth of spoilage bacteria in pasteurized milk.

METHODS AND RESULTS

Spoilage bacteria isolated from pasteurized milk at 8 and 15°C were identified as Enterococcus italicus, Enterococcus mundtii, Enterococcus faecalis, Bacillus thuringiensis, Bacillus cereus, Lactobacillus paracasei, Acinetobacter sp., Pseudomonas fluorescens and Enterobacter aerogenes. These bacteria were found to have the ability to survive pasteurization temperature. Except Enterobacter aerogenes, the spoilage bacteria were sensitive to the nisin Z preparation of the L. lactis W8. Addition of the nisin Z preparation to either the skim milk or fat milk inoculated with each of the spoilage bacteria reduced the initial counts (about 5 log CFU ml⁻¹) to an undetectable level within 8-20 h. The nisin Z preparation extended the shelf life of milk to 2 months under refrigeration.

CONCLUSIONS

The nisin Z preparation from L. lactis W8-fermented milk was found to be effective as a backup preservative to counteract postpasteurization contamination in milk.

SIGNIFICANCE AND IMPACT OF THE STUDY

A rapid inhibition of spoilage bacteria in pasteurized skim and fat milk with the nisin Z preparation of L. lactis W8 is more significant in comparison with the commercially available nisin (nisin A). The nisin Z preparation can be used instead of commercial nisin, which is not effective in fat milk.