Rickettsial microbiology

Optimized fixation of actin filaments for improved indirect immunofluorescence staining of rickettsiae

Objective

The objective was to investigate fixative solutions: 3.7% formaldehyde, 4% paraformaldehyde, 4% paraformaldehyde in the cytoskeletal buffer and 4% paraformaldehyde in PHEM buffer (containing PIPES, HEPES, EGTA and MgCl₂), applicable for immunofluorescence assay.

Results

Herein we optimized this serological technique, testing four fixative solutions, for the sensitive detection of rickettsial antigens, and preservation of intracellular structures of the host cells, particularly filamentous actin. Rickettsial antigens were presented equally well both with formaldehyde and all paraformaldehyde-based fixations, but only protocol with 4% paraformaldehyde in PHEM buffer allowed accurate imaging of actin filaments, and simultaneously allows monitoring of rickettsiae using actin-based motility during infection inside the host cells.

The efficacy of amlexanox OraDisc on the prevention of recurrent minor aphthous ulceration

BACKGROUND

The study was designed to determine the efficacy of OraDisc (active component 2 mg amlexanox) on the prevention of aphthous ulcers treated at the prodromal stage.

METHODS

Thermographic imaging was used to confirm the presence of a prodromal ulcer. Fifty-two patients were randomized to receive OraDisc (N = 26) or vehicle patches (N = 26). Patches were applied four times a day for 72 h over the prodromal area. The percentage of subjects who developed an ulcer at 72 h was compared between groups using the Fisher's exact test.

RESULTS

About 50% of subjects in the OraDisc group developed an ulcer by day 4 compared with 69% in the vehicle group. Erythema score, ulcer size, pain scores and thermographically active area and temperature all showed trends towards healing in the OraDisc group.

CONCLUSION

The OraDisc prevents ulcers from developing when compared with the vehicle patch.

A comparative study of the efficacy of AphthealTM in the management of recurrent minor aphthous ulceration

BACKGROUND

Recurrent minor aphthous ulceration (RAU) is a common condition which is multifactorial in origin.

METHODS

This study, firstly, aimed to treat the prodromal stage of RAU with Aphtheal (5% amlexanox paste) to determine if ulcer development could be prevented. A second arm of the study investigated treatment of RAU with Aphtheal once ulceration had developed. Ulcer duration, ulcer size and associated pain were measured. Both groups of subjects had previously undergone a no-treatment run-in period to establish these parameters over an untreated episode of ulceration.

RESULTS

By day 3, only 35% of the prodromal group had developed an ulcer compared with 97% of the ulcer group (P < 0.001). In the treated ulcer group only 66% had an ulcer present by day 3. Treatment at the onset of prodromal symptoms reduced the maximum ulcer size score by 84% (P < 0.01), extent of ulceration by 88% (P < 0.01), maximum pain score by 69% (P < 0.01) and extent of pain by 85% (P < 0.01) compared to no treatment.

CONCLUSION

Treatment with Aphtheal at the onset of prodromal RAU symptoms can prevent progression to ulcer development and significantly reduced symptoms if ulcers do develop.