Autofluorescence spectroscopy in photodynamic therapy for skin rejuvenation: A theranostic approach in aesthetic medicine.

BACKGROUND: The method of photodynamic therapy for skin rejuvenation (PDT-SR) provides an improvement in appearance with a safe and painless effect. The quality of treatment is most often assessed subjectively. The most informative morphological control methods are rarely used due to the invasiveness of the sampling procedure. AIM: This study aimed to find out the possibility of using skin autofluorescence spectroscopy (SAF) for an objective assessment of changes occurring in the skin during PDT-SR. METHODS: This study included 12 volunteers (10 women, 2 men) aged 32 to 79 years. Two (n = 6) or three (n = 6) PDT sessions were performed at intervals of 13-30 days. Photosensitizer chlorin e6, exposure 20 min, energy density 18-24 J/cm2 were used. SAF spectra were recorded using a two-wavelength fiber optic spectrometer under excitation at wavelengths (λex) of 365 nm and 440 nm. Measurements were made both before and after each PDT session and up to 25-238 days from the start of treatment. For the evaluation, we used the spectra AF365(λ) and AF440(λ) averaged over 40 points corrected for diffuse reflection at λex=440 nm in the range λem= 460-700 nm, as well as the spectra of the ratios AFN365(λ) and AFN440(λ), which were obtained by dividing the intensities of the current spectra by the intensities collected before PDT-SR. RESULTS: PDT-SR led to changes in both the intensity and shape of the spectra. Analysis of the spectra using numerical fitting of the spectra showed that the main changes can be explained by changes in the content of advanced glycation end products (AGEs), as well as lipofuscin-like lipopigments (LPs) and porphyrins (PPs). The spectra of AGEs upon excitation at wavelengths of 365 and 440 nm differ, which may be due to the formation of two types of bonds, with collagen and elastin. By the end of the study, the vast majority of the examined volunteers showed a significant decrease of the parameters characterizing both of these types of AGEs, AGE365 (0.56-1.2) and AGE440 (0.58-1.01), relative to the beginning of the study. In most cases, a decrease was also noted for LPs and PPs. AGE365 and AGE440 were positively correlated with the age of the volunteers (r2 = 0.26-0.46 %). A steady decrease in the content of AGEs occurred approximately on the 40th day. CONCLUSION: SAF spectroscopy makes it possible to assess changes in the content of AGEs, LPs, and PPs in the skin during PDT-SR. The method has great potential for non-invasive monitoring of the treatment process, as well as its improvement, including through its personalization. In addition, the method can be used to study the mechanisms of age-related skin changes at the molecular level and to study the processes of rejuvenation.

Thrombin generation test for evaluation of antiplatelet treatment in patients with coronary artery disease after percutaneous coronary intervention.

To study the possibility of using thrombin generation tests in platelet-rich and platelet-poor plasma for evaluation of dual antiplatelet therapy efficacy in patients with coronary artery disease (CAD), following percutaneous coronary intervention. Venous blood was analyzed from CAD patients aged 53-75 years who had undergone percutaneous coronary intervention with stenting within one year and had been receiving standard doses of clopidogrel and aspirin (75 and 75-100 mg per day, respectively). The control group comprised age- and sex-matched subjects without clinical signs of CAD who were not receiving these drugs. Thrombin generation tests were performed in platelet-rich and platelet-poor plasma. Intravascular platelet activation, induced platelet aggregation, and routine coagulation were evaluated. Antiplatelet treatment did not influence results of routine coagulation tests or intravascular platelet activation. The dual antiplatelet therapy affects collagen-induced platelet aggregation (44 ± 2.5 vs. 7.9 ± 2.6%, р = 10-7) and leads to decreases in endogenous thrombin potential (1900 ± 85 vs. 1740 ± 95 nM∙min, p = 0.0045), maximum thrombin concentration (134 ± 9.5 vs. 106 ± 6.5 nM, p = 4∙10-6), and increases in time to peak thrombin (27 ± 1.5 vs. 31 ± 2 min, p = 0.0012). Decreases in thrombin generation rate showed the highest statistical significance (13 ± 2 vs. 7.9 ± 0.8 nM/min, p = 10-8). Antiplatelet treatment did not alter thrombogram parameters for platelet-poor plasma.

L-theanine administration results in neuroprotection and prevents glutamate receptor agonist-mediated injury in the rat model of cerebral ischemia-reperfusion.

While the neuroprotective effect of green tea (Camellia sinensis) might be explained by the presence of amino acid L-theanine in the tea leaves, it is not known whether postischemic administration of L-theanine could also provide neuroprotection. In the present study, we investigated the neuroprotective effect of L-theanine (1 and 4 mg/kg) administered at 3, 12, and 24 h after reperfusion in the rat model of stroke. We also studied the effect of L-theanine on brain injury caused by exogenous administration of N-methyl-D-aspartate and α-amino-3-hydroxy-5-methyl-isoxazole-4-propionate/kainate receptor agonists during reperfusion. Rats were subjected to 30-min middle cerebral artery occlusion followed by 48-h reperfusion. Neurological deficit and infarct size were determined at the end of reperfusion. At 3 and 12 h, but not at 24 h of reperfusion, L-theanine substantially reduced the size of brain infarct. Neurological status was improved when L-theanine was administered 3, 12, and 24 h after reperfusion. Repeated intrastriatal injections of L-theanine at a total dose of 800 µg/kg during reperfusion prevented brain injury caused by glutamate receptor agonists. In conclusion, L-theanine at reperfusion exerts neuroprotective effect in the in vivo rat model of stroke. Local treatment with L-theanine at reperfusion prevents glutamate receptor agonist-mediated brain injury.

Immunomodulating and anti-tumor action of extracts of several mushrooms.

Aqueous extracts from fruit bodies and mycelia of various higher Basidiomycetes were studied in search for reliable biological effects. In vitro and in vivo experiments were conducted. The results showed that the aqueous extracts demonstrated various types of marked biological actions: an increased production of reactive oxygen forms by neutrophil cells of human peripheral blood; a significant mitogenic activity in a wide range of concentrations; stimulation on production of inflammatory cytokines interleukine 1-beta and interleukine-8 by peripheral blood cells; a decrease in both average tumor size in mice with transplanted melanoma B16 and a manifestation of tumorous intoxication; and a prolongation in the survival rate of such mice.