Recently, fluorescence microscopy becomes more available, presenting new opportunities to face several challenges of experimental biology and medicine. The study was aimed to assess the effectiveness of fluorescence microscopy for the identification of amyloid deposits in human tissues. Post-mortem samples of the myocardium (n = 12) and cerebral cortex (n = 8) obtained from subjects of both sexes aged 60–98 with verified amyloidosis were used as a material for the study. The specimens were stained using 11 different histochemical dyes and subsequently analyzed by light and fluorescence microscopy. Qualitative and quantitative analysis has shown that Thioflavin T is the most effective stain for fluorescence detection of β- and transthyretin amyloid in human tissues. Congo red staining is highly effective for the detection of transthyretin amyloidosis, however, it is ill-suited for the identification of β-amyloid plaques. It has been found that the ability of Congo red to exhibit fluorescence when binding to amyloid fibrils can be used for verification of amyloid deposits instead of the traditional polarized light microscopy. As has been first noted, methyl violet can selectively bind to β-amyloid with fluorescent complex formation. In addition, methyl violet treatment effectively reduces the autofluorescent background in the nervous tissue. This makes methyl violet staining a promising diagnostic tool for Alzheimer's-type pathology.
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Neonates born to mothers with COVID-19 are at risk for infection, they may have high risk of complications during the neonatal period, and long-term health consequences. The study was aimed to define the amino acid profile of blood plasma and amniotic fluid in patients with COVID-19 in order to assess the relationship between the COVID-19 infection during the antenatal period, and metabolomic alterations in the “intrauterine” patient. The levels of 31 amino acids in the samples of amniotic fluid and cord blood plasma of pregnant women with COVID-19, obtained during delivery, were assessed by high-performance liquid chromatography-mass spectrometry. The index group included 29 patients with confirmed diagnosis of COVID-19, and the control group included 17 healthy women with uncomplicated pregnancies. There were significant (p < 0.05) differences in the concentrations of eight amino acids between the studied groups. Logistic regression models were developed (sensitivity 0.84; specificity 1) making it possible to define, whether the assessed amniotic fluid was obtained from COVID-19 patients. Significant differences in the concentrations of four amino acids were observed in the umbilical cord blood. The models developed made it possible to define whether the studied cord blood plasma belonged to controls or to COVID-19 patients (sensitivity and specificity 1). Three amino acids were detected, and their levels were significantly different in COVID-19 patients simultaneously in two points (amniotic fluid and cord blood plasma), depicting the fetal metabolome in a holistic manner. The impact of the virus on those infected results in pronounced metabolomic alterations in the amniotic fluid and the fetal cord blood plasma, which may lead to impaired programming of protein production, but never show up at birth.
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Most cancer drugs used in a clinical setting are insufficiently effective and insufficiently safe. This prompts the search for novel substances to fight cancer. The aim of this study was to explore the effects of dihydrobromide 2-(3,4-dihydroxyphenyl)-9-diethylaminoethylimidazo[1,2-a] benzimidazole (RU-185) on the growth and metastasis of experimentally induced transplantable Lewis lung carcinoma (LLC). Fifty-five C57/Bl6 male mice (weight 18–20 g) were subcutaneously inoculated with LLC cells. The tested substance (0.5 ml) was administered intragastrically at 50, 220, and 500 mg/kg (groups 1, 2 and 3, respectively) once a day for 10 days starting at 48 h after inoculation. The control group received normal saline. Intragastric administration of the tested substance resulted in significantly longer survival in group 2 only (162.3%) and in the significant reduction of tumor size on day 1 after treatment in all groups. After the end of treatment, tumor sizes in groups 2 and 3 were 3.4 and 1.3 times smaller, respectively, on day 7 and 2.2. and 1.3 times smaller, respectively, on day 14 than in the control group (р < 0,05). The growth delay rate was sustained in group 2 by day 14 after the end of treatment; tumor regression was observed in 20% of the animals. The number of metastases in the lungs was lower in groups 1 and 2 than in the control group (2.6 and 3.1-fold, respectively), and the metastasis inhibition was 68.1% and 80%, respectively. The tested substance RU-185 has an anticancer effect in mice: it results in longer survival, slower growth of the primary tumor and fewer lung metastases of Lewis lung carcinoma.
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Lipid-lowering drugs affect standard lipoproteins. However, we have no knowledge of changes in other plasma lipids upon treatment. The study was aimed to assess the dynamic changes in cholesterol, high- and low-density lipoproteins (HDL and LDL), triglycerides, and sphingolipids against the background of lipidlowering therapy in patients with premature coronary artery disease, atherosclerosis and hypercholesterolemia. A total of 18 patients were enrolled (the average age was 53 ± 6.7 years): in group 1, six patients received starting statin doses; group 2 included six patients, who failed to achieve LDL target levels against the background of treatment with starting statin doses, and received escalated statin doses; seven patients in group 3 failed to achieve LDL target levels against the background of treatment with maximum tolerated doses of statins and ezetimibe, and received alirocumab. Sphingolipid levels were assessed by mass spectrometry. In group 1, the decreased levels of ceramide Cer 14:1 (p = 0.046) and sphingomyelins SM 22:1, SM 22:0, SM 24:0 (p = 0.028) were observed. There were no significant changes in the levels of total cholesterol, LDL-C, HDL-C, and triglycerides. In group 2, the significantly decreased levels of total cholesterol (p = 0.028), LDL (p = 0.043), sphingomyelins SM 18:1, SM 24:1 and SM 26:1, and ceramide Cer 16:1 (p = 0.028) were observed. The level of Cer 22:1 significantly increased (p = 0.028). In group 3, total cholesterol decreased by 36.2%, and LDL-C (p = 0.018) decreased by 60.1% compared to baseline (ΔLDL-C = –2.67 ± 3.12); the elevated levels of ceramide Cer 22:1 (p = 0.028) were observed. It has been shown, that decreased sphingomyelin levels are associated with statin therapy and correlate with decreased levels of LDL-C. No significant dynamic changes in ceramides and ceramide risk against the background of statin therapy were observed, however, PCSK9 inhibitor added to therapy reduced the Cer 16:0/24:0 ratio.
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Currently, biophysical studies are of great interest, the results of which are important for development of a method for diagnosis of the cells and tissue condition to be used in clinical practice. The study was aimed to use a non-invasive optical method (Raman spectroscopy) for assessment of changes in the composition and conformation of the molecules of the patient’s mandibular cells and tissues. This approach was proposed to increase the informativeness and effectiveness of studying the composition of autografts harvested for augmentation of alveolar processes with bone tissue deficiency  (elective bone grafting). In the course of the study the bone tissue samples obtained from three patients aged 51–73 (two men and one woman) were assessed. Raman signals were detected, indicating the presence of phosphate groups and carbonate ions (such as СО3–2) of the inorganic bone components. Raman bands indicating the presence of collagen, red blood cell hemoglobin, proteins (C–N bonds), lipids (С–Н groups of fatty acids and phosphate groups of phospholipids), as well as their OH groups may be considered the markers of periosteum tissue. The general possibility was suggested of studying single cells of autografts using the markers, indicating the presence of collagen, hemoglobin, proteins, lipids (С–Н groups of fatty acids of lipids; phosphate groups of phospholipids), and their OH groups. According to the authors, the results obtained can provide a basis for development of the new method for diagnosis of autograft bone using the combination of Raman spectroscopy and light guides.
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Repetitive transcranial magnetic stimulation (rTMS) is an alternative treatment option for patients with drug-resistant trigeminal neuralgia (TN). However, the effect of rTMS is variable. The aim of this study was to find neuroimaging biomarkers of clinical efficacy of navigated rTMS. Seventeen patients with TN (14 women and 3 men, median age 56 years) received 10 sessions of high-frequency rTMS of the motor cortex contralateral to pain side. The data were analyzed for correlations between functional connectivity (FC), the grey matter (GM) volume and the reduction in pain intensity. Positive correlations were established between the reduction in average pain intensity and GM volume in caudate nuclei in both hemispheres (p(unc) = 0.03), both cerebellar hemispheres (p(unc) = 0.002) and the postcentral gyrus contralateral to pain side (p(unc) = 0.005); between the reduction in peak pain intensity and GM volume in the caudate nucleus contralateral to pain side (p(unc) = 0.04) and the cerebellar hemisphere ipsilateral to pain (p(unc) = 0.03). Significant positive correlations were discovered between the reduction in average pain intensity and FC between the thalamus contralateral to pain side, the postcentral gyrus and the insular operculum (both ipsilateral to pain side; (p(FWE) = 0.018), as well as between the cingulate cortex and the anterior cingulate cortex ipsilateral to pain (p(FWE) = 0.017), between the contralateral subcallosal gyrus and the cerebellar hemisphere ipsilateral to pain (p(FWE) = 0.018). A negative correlation was established for FC between the contralateral putamen and the occipital lobes in both hemispheres (p(FWE) = 0.001). Our findings may spur the development of individual predictors of rTMS efficacy in patients with chronic pain.
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