Economical LED based, real-time, in vivo imaging of murine corneal wound healing

Laser Therapy for Incision Healing in 9 Dogs

Laser therapy is becoming common place in veterinary medicine with little evidence proving efficacy or dosages. This study evaluated surgical wound healing in canines. Twelve Dachshunds underwent thoraco-lumbar hemilaminectomies for intervertebral disc disease (IVDD). Digital photographs were taken of their incisions within 24 h of surgery and 1, 3, 5, 7, and 21 days postoperatively. The first three dogs were used to create a standardized scar scale to score the other dogs' incision healing. The remaining 9 dogs were randomly assigned to either receive 8 J/cm2 laser therapy once a day for 7 days or the non-laser treated control group. Incision healing was scored based on the scar scale from 0 to 5, with zero being a fresh incision and five being completely healed with scar contraction and hair growth. All scar scores significantly improved with increasing time from surgery (<0.001). Good agreement was achieved for inter-rater reliability (p = 0.9). Laser therapy increased the scar scale score, showed improved cosmetic healing, by day seven and continued to be significantly increased on day 21 compared to control dogs (p < 0.001). Daily application of laser therapy at 8J/cm2 hastened wound healing in Dachshunds that received thoracolumbar hemilaminectomies for IVDD. It also improved the cosmetic appearance.

The impact of virulence factors of Porphyromonas gingivalis on wound healing in vitro

Background

Porphyromonas gingivalis inhibits oral epithelial wound healing in vitro more strongly than other oral bacteria, but it is unknown why P. gingivalis is such a potent inhibitor of wound healing.

Objective

Therefore, the aim of this study was to investigate the influence of major virulence factors of P. gingivalis on wound healing in an in vitro wound-healing model. The influence of the capsular polysaccharide, the Arg- and Lys- gingipains, the major fimbriae and lipopolysaccharide (LPS) was investigated.

Design

A standardized scratch was made in a confluent layer of human oral epithelial cells HO-1-N-1. The epithelial cells were then challenged with different concentrations of several P. gingivalis wild-type strains and knockout mutants. Closure of the scratch was determined after 17 h and compared to control conditions without bacteria.

Results

The P. gingivalis strains ATCC 33277, W83, and W50 significantly inhibited wound healing. The presence of a capsular polysaccharide lowered significantly the inhibition of epithelial cell migration, while gingipain activity significantly increased the inhibition of cell migration. LPS and the major fimbriae did not influence epithelial cell migration. None of the tested P. gingivalis strains completely prevented the inhibition of cell migration, suggesting that other characteristics of P. gingivalis also play a role in the inhibition of wound healing, and that further research is needed.

Conclusions

The capsular polysaccharide and the Arg- and Lys- gingipains of P. gingivalis influenced the capacity of P. gingivalis to hinder wound healing, while LPS and the major fimbriae had no effect.

A fiber-optic fluorescence microscope using a consumer-grade digital camera for in vivo cellular imaging

Background

Early detection is an essential component of cancer management. Unfortunately, visual examination can often be unreliable, and many settings lack the financial capital and infrastructure to operate PET, CT, and MRI systems. Moreover, the infrastructure and expense associated with surgical biopsy and microscopy are a challenge to establishing cancer screening/early detection programs in low-resource settings. Improvements in performance and declining costs have led to the availability of optoelectronic components, which can be used to develop low-cost diagnostic imaging devices for use at the point-of-care. Here, we demonstrate a fiber-optic fluorescence microscope using a consumer-grade camera for in vivo cellular imaging.

Methods

The fiber-optic fluorescence microscope includes an LED light, an objective lens, a fiber-optic bundle, and a consumer-grade digital camera. The system was used to image an oral cancer cell line labeled with 0.01% proflavine. A human tissue specimen was imaged following surgical resection, enabling dysplastic and cancerous regions to be evaluated. The oral mucosa of a healthy human subject was imaged in vivo, following topical application of 0.01% proflavine.

Findings

The fiber-optic microscope resolved individual nuclei in all specimens and tissues imaged. This capability allowed qualitative and quantitative differences between normal and precancerous or cancerous tissues to be identified. The optical efficiency of the system permitted imaging of the human oral mucosa in real time.

Conclusion

Our results indicate this device as a useful tool to assist in the identification of early neoplastic changes in epithelial tissues. This portable, inexpensive unit may be particularly appropriate for use at the point-of-care in low-resource settings.

Beta2-adrenergic receptor signaling mediates corneal epithelial wound repair

PURPOSE

Beta-adrenergic receptor (AR) antagonists are frequently prescribed ophthalmic drugs, yet previous investigations into how catecholamines affect corneal wound healing have yielded conflicting

RESULTS

With the use of an integrated pharmacologic and genetic approach, the authors investigated how the beta-AR impacts corneal epithelial healing.

METHODS

Migratory rates of cultured adult murine corneal epithelial (AMCE) cells and in vivo corneal wound healing were examined in beta2-AR(+/+) and beta2-AR(-/-) mice. Signaling pathways were evaluated by immunoblotting. results. The beta-AR agonist isoproterenol decreased AMCE cell migratory speed to 70% of untreated controls, and this was correlated with a 0.60-fold decrease in levels of activated phospho-ERK (P-ERK). Treatment with the beta-AR antagonist (timolol) increased speed 33% and increased P-ERK 2.4-fold (P < 0.05). The same treatment protocols had no effect on AMCE cells derived from beta2-AR(-/-) mice; all treatment groups showed statistically equivalent migratory speeds and ERK phosphorylation. In beta2-AR(+/+) animals, the beta-AR agonist (isoproterenol) delayed the rate of in vivo corneal wound healing by 79%, whereas beta-AR antagonist (timolol) treatment increased the rate of healing by 16% (P < 0.05) compared with saline-treated controls. In contrast, in the beta2-AR(-/-) mice, all treatment groups demonstrated equivalent rates of wound healing. Additionally, murine corneal epithelial cell expressed the catecholamine-synthesizing enzyme tyrosine hydroxylase and detectable levels of epinephrine (184.5 pg/mg protein).

CONCLUSIONS

The authors provide evidence of an endogenous autocrine catecholamine signaling pathway dependent on an intact beta2-AR for the modulation of corneal epithelial wound repair.