Chitosan: antimicrobial action upon staphylococci after impregnation onto cotton fabric

BACKGROUND

High levels of viable Staphylococcus aureus, which are often found on inflamed skin surfaces, are usually associated with atopic dermatitis. Textiles, owing to their high specific surface area and intrinsic hydrophilicity, retain moisture while also providing excellent environmental conditions for microbial growth and proliferation. Recently, a number of chemicals have been added to textiles, so as to confer antimicrobial activity.

AIMS

To evaluate the antimicrobial action of chitosan upon selected skin staphylococci.

METHODS AND RESULTS

We isolated staphylococci from normal skin of 24 volunteers and studied their survival upon contact with chitosan-impregnated cotton fabric. Low and high molecular weight chitosans were used at two concentrations; all four did effectively reduce the growth of some staphylococci (namely Staph. aureus), by up to 5 log cycles, thus unfolding a potential towards control and even prevention of related skin disorders.

CONCLUSION

Our data suggest an effective, but selective antibacterial action of chitosans towards skin bacteria.

SIGNIFICANCE AND IMPACT OF THE STUDY

The possibility to use a natural biopolymer incorporated in a textile to alleviate and even treat some of the symptoms associated with this skin condition may raise an alternative to existing medical treatments. The selectivity observed prevents full elimination of bacteria from the skin surface, which is an advantage.

Vibration does not improve results of the canalith repositioning procedure

OBJECTIVE

To determine whether, in patients with benign paroxysmal positional vertigo (BPPV), the canalith repositioning procedure performed with vibration applied over the mastoid bone of the affected ear is more effective in resolving the symptoms and preventing recurrence of BPPV than the procedure performed without vibration.

DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Ninety-four patients diagnosed as having BPPV involving the posterior semicircular canal.

INTERVENTIONS

Patients were assigned to one of 2 treatment groups: the canalith repositioning procedure with vibration (n=44) and with no vibration (n=50).

MAIN OUTCOME MEASURES

Effectiveness of treatment was determined through clinical reevaluation or reported through a telephone interview 1 week after treatment. Intensity of symptoms was quantified on a scale of 1 to 3 (mild, moderate, or severe); effectiveness of treatment was categorized on a scale of 1 to 4 (cure, much better, better, or no change). Rate of recurrence was determined through later clinical reevaluation or a telephone interview.

RESULTS

At 1 week, 57 of the 94 patients were cured and 16 were much better, providing a 78% overall success rate. There was no significant difference in effectiveness of the treatment or the frequency of reoccurrence of BPPV between the vibration and no-vibration groups as determined from the Kaplan-Meier product-limit method and log-rank test. Rate of recurrence was 47% at a maximum follow-up of 5.25 years.

CONCLUSIONS

Our results suggest that, while the canalith repositioning procedure is effective in the treatment of BPPV, vibration applied during the maneuver does not significantly affect short-term or long-term outcomes.

Metabolic abnormalities detected by 1H-MRS in dyscalculia and dysgraphia

Proton MRS was performed in a patient with developmental acalculia. The results indicated a focal, wedge-shaped defect in the left temporoparietal brain region near the angular gyrus, with differential decreases in N-acetyl-aspartate, creatine, and choline. These results support the hypothesis that developmental acalculia, like acquired acalculia, is associated with left posterior hemisphere lesions.