Influence of optical clearing agents on the scattering properties of human nail bed and blood microrheological properties: In vivo and in vitro study.

Optical clearing agents (OCAs) are substances that temporarily modify tissue's optical properties, enabling better imaging and light penetration. This study aimed to assess the impact of OCAs on the nail bed and blood using in vivo and in vitro optical methods. In the in vivo part, OCAs were applied to the nail bed, and optical coherence tomography and optical digital capillaroscopy were used to evaluate their effects on optical clearing and capillary blood flow, respectively. In the in vitro part, the collected blood samples were incubated with the OCA and blood aggregation properties were estimated using diffuse light scattering techniques. The results indicate that OCAs significantly influence the optical properties of the nail bed and blood microrheology. These findings suggest that OCAs hold promise for improving optical imaging and diagnostics, particularly for nail bed applications, and can modify blood microrheology.

Multimodal Optical Diagnostics of Glycated Biological Tissues.

Diabetes mellitus is a metabolic disorder characterized by chronic hyperglycemia accompanied by the disruption of carbohydrate, lipid, and proteins metabolism and development of long-term microvascular, macrovascular, and neuropathic changes. This review presents the results of spectroscopic studies on the glycation of tissues and cell proteins in organisms with naturally developing and model diabetes and in vitro glycated samples in a wide range of electromagnetic waves, from visible light to terahertz radiation. Experiments on the refractometric measurements of glycated and oxygenated hemoglobin in broad wavelength and temperature ranges using digital holographic microscopy and diffraction tomography are discussed, as well as possible application of these methods in the diabetes diagnostics. It is shown that the development and implementation of multimodal approaches based on a combination of phase diagnostics with other methods is another promising direction in the diabetes diagnostics. The possibilities of using optical clearing agents for monitoring the diffusion of substances in the glycated tissues and blood flow dynamics in the pancreas of animals with induced diabetes have also been analyzed.

[Role of platelets in the pathogenesis of Coxiella infection].

AIM: To determine the relationship of hemostatic disorders to the direct impact of Coxiella burnetii on platelets as one of the key mechanisms of the pathogenesis of Q fever. SUBJECTS AND METHODS; Platelet functional activity, plasma hemostatic parameters, von Willibrand factor (vWF) were investigated; and polymerase chain reaction assay was used to determine C. burnetii DNA in the leukocyte and platelet sediments of 41 patients aged 39.9 +/- 0.8 years diagnosed with Q fever at the Astrakhan Regional Clinical Hospital in 2009 to 2010. RESULTS: The examinees were recorded to have hemorrhagic phenomena (34.7%) as a hematoma (27.2%), gingival (2.4%) and nasal (9.2%) hemorrhages, vomiting blood streaks (3.4%), melena (4.5%), roseolous-papular (22.1%) and hemorrhagic (9.3%) rashes on the skin. Examination of hemostasis revealed thrombocytopenia and platelet hypoaggregation, increased plasma fibrinogen homeostasis, and significantly elevated vWF during convalescence. C. burnetii genomic DNA was isolated from platelets in all the examinees, from leukocytes and platelets in 78% of cases and only from platelets in 22%. A fluorescence signal indicating the pathogen genome was more early recorded in 54.8% of cases in the platelets than in the leukocytes. CONCLUSION: At week 1 of the disease, the absence of significant plasma hemostatic changes and the retention of the control level vWF with the lower count of platelets and their aggregatory activity suggest that the platelets are able to interact with this pathogen, which is confirmed by the results of genodiagnosis of this rickettsiosis with the pathogens being isolated from the platelet sediment. The determination of platelet aggregatory activity is a primary diagnostic test to detect disorders in the hemostatic system. The higher detection rate of C. burnetii genomic DNA from the platelets than from the leukocyte sediment can recommend that platelets be used as biological material in the diagnosis of Q fever.

[Implication of functional platelet activity in pathogenesis of Q-fever].

AIM: To ascertain the role of platelets in pathogenesis of clinical symptoms in patients with Q-fever. MATERIAL AND METHODS: We studied hemostasis with estimation of functional platelet activity in 49 patients with Q-fever. RESULTS: Hemorrhagic syndrome (HS) occurred in 34.4% patients with Q-fever (QF) during seasonal rise of morbidity. HS manifested with petechiae (12%), hematomas (32%), nasal bleeding (17%), stomatorrhagia (9%), melena (12%). Characteristics and duration of such symptoms as weakness (100%), myalgia (72%), arthralgia (52.9%) suggested hemocoagulatory disorders as a cause of the symptoms appearance. At the height of the disease thrombocytopenia was accompanied with inhibition of platelet aggregation activity, but regression of the clinical symptoms was associated with an increase in platelet count and platelet hyperaggregation. Fibrinogen content was elevated during hospitalization in 50% patients. CONCLUSION: Clinical manifestations of HS are typical for Q-fever prevalent in the Astrakhan Region. Hemostatic disorders because of altered functional activity of platelets were registered in all the cases and evidence for pathogenetic unbalance of homeostasis in Q-fever patients.

[Hemostatic disorders and their implication in the pathogenesis of Astrakhan rickettsial fever].

AIM: to define a role of hemostatic disorders in the pathogenesis of Astrakhan rickettsial fever (ARL). SUBJECTS AND METHODS: Platelet functional activity and plasma hemostatic parameters were studied in 89 patients of moderate ARL. RESULTS: The clinical manifestations of hemostatic disorders at the height of ARL were characterized by the appearance of typhoid maculopapular rashes in 91.4% of the patients, solitary elements of which were transformed to petechiae in 20% of cases. At convalescence (on day 10.2 +/- 1.3 of the disease), all eruptions regressed via pigmentation. At the peak of the fever, there were nasal hemorrhages and bleedings from the sites of injections; lowered platelet aggregation was detectable in the presence of thrombocytopenia at the height. Coagulation hemostasis changes were characterized only by elevated fibrinogen levels. Increased platelet functional activity and decreased fibrinogen concentrations were observed at convalescence. CONCLUSION: The basis of the clinical manifestations of ARL is hemostatic disorders due to thrombocytopenia and diminished platelet functional activity. In early convalescence, there was improved platelet aggregatability; however, the increasing trend for the rate of aggregation and the radius of aggregates suggests a risk of thrombogenesis in convalescents, which requires their follow-up with obligatory hemostatic monitoring.