Low-Power Laser Irradiation (LPLI): A Clinical Point of View on a Promising Strategy to Improve Liver Regeneration

Study of laser fluorescence spectroscopy in livers of rats with hypothermic ischemia

PURPOSE

After partial hepatectomy (PH), the remaining liver (RL) undergoes regenerative response proportional to the host. Limited literature exists on hepatic viability after tissue injury during hypothermic preservation. Spectroscopy measures cellular fluorescence and is explored for tissue characterization and parameter investigation. This study aimed to assess fluorescence analysis (spectroscopy) in evaluating liver viability and its relationship with hepatic tissue regeneration 24 hours after PH. Additionally, we analyzed liver regeneration in RL after 70% partial hepatectomy under hypothermic conditions with laser irradiation.

METHODS

Fifty-six Wistar rats were divided into four groups: total non-perfused liver (control), total perfused liver, partial hepatectomy "in situ", and partial hepatectomy "ex situ". Tissue analysis was performed at 0 and 24 hours using spectroscopy with laser devices emitting at 532 (green) and 405 nm (violet).

RESULTS

Spectroscopy identified tissue viability based on consistent results with Ki67 staining. The fluorescence spectra and Ki67 analysis displayed similar patterns, linking proliferative activity and absorption intensity.

CONCLUSIONS

Fluorescence spectroscopy proves to be promising for real-time analysis of cellular activity and viability. Metabolic activity was observed in groups of live animals and hypothermically preserved samples, indicating cellular function even under blood deprivation and hypothermic conditions.

Increasing Quantity and Internal Quality of Japanese Quail (Coturnix coturnix japonica) Eggs by Shooting Laser Puncture at Reproductive Acupuncture Points

This study aims to determine the effect of laser puncture shooting on the reproductive acupuncture points of Japanese quail (Coturnix coturnix japonica) egg quantity (egg production) and internal egg quality (Haugh unit, yolk index, and yolk colour). This research was conducted for 30 days using a sample of Japanese quail aged 4 weeks because for the first 2 weeks, the quail did not produce and it was in production in the last 2 weeks. There were 4 treatments and 25 replications each. So, there were a total of 100 quails. Laser puncture shooting was carried out at 3-day intervals at the Ova point and 6-day intervals at Hu Men, Bei Ji, and Wei Gen points. So, on the first day, laser puncture shooting was carried out at 4 points, on the 4th day, only at 1 point, and then, on the 7th day, it returned to 4 points. And so, it was carried out for 4 weeks. T0 (-) was considered as a negative control because quails are not given laser puncture shooting; T0 (+) was considered as a positive control because quails are treated with laser puncture shooting which is deactivated or a dose of 0 Joule; T1 was a group treated with laser puncture shooting at a dose of 0.2 Joule, and T2 was a group treated with laser puncture shooting at a dose of 0.5 Joule. Then, the research results were analyzed using Analysis of Variance and followed by Duncan's Multiple Range Test. Laser puncture shooting at the reproductive acupuncture point of Japanese quail (Coturnix coturnix japonica) can increase the quantity of eggs (p < 0.05). While the results of the egg internal quality in the form of the Haugh unit value and the yolk index increased (p < 0.05), the value of the yolk colour did not change compared to the control (p > 0.05). Laser puncture shooting at the reproductive acupuncture point of Japanese quail (Coturnix coturnix japonica) can increase egg quantity (egg production) and internal egg quality (Haugh unit and yolk index) with the best dose of 0.5 Joule.

The Effect of Photobiomodulation Therapy on the Differentiation, Proliferation, and Migration of the Mesenchymal Stem Cell: A Review

Introduction: The purpose of this study is to investigate the effect of a low-power laser on the proliferation, migration, differentiation of different types of mesenchymal stem cells (MSCs) in different studies. Methods: The relevant articles that were published from 2004 to 2019 were collected from the sources of PubMed, Scopus, and only the articles specifically examining the effect of a lowpower laser on the proliferation, differentiation, and migration of the MSCs were investigated. Results: After reviewing the literature, only 42 articles were found relevant. Generally, most of the studies demonstrated that different laser parameters increased the proliferation, migration, and differentiation of the MSCs, except the results of two studies which were contradictory. In fact, changing the parameters of a low-power laser would affect the results. On the other hand, the source of the stem cells was reported as a key factor. In addition, the combination of lasers with other therapeutic approaches was found to be more effective. Conclusion: The different parameters of lasers has been found to be effective in the proliferation, differentiation, and migration of the MSCs and in general, a low-power laser has a positive effect on the MSCs, helping to improve different disease models.