Characterization of cervical tissue using Mueller matrix polarimetry.

The cervix is composed of layers of squamous epithelium and connective tissue. The main component of the cervical connective tissue is collagen, which has specific orientations in different parts of the cervix and provides mechanical strength. Cervical pathologies such as cervical intraepithelial neoplasia (CIN), cancer, pregnancy, and spontaneous preterm birth (sPTB) allow for structural remodeling of both squamous epithelium and connective tissue. Mueller matrix (MM) polarimetry is an optical imaging technique that uses polarized light to characterize the morphologic changes in pathological cervix. In this study, advances in MM polarimetry in characterizing cervical tissue and associated pathologies were reviewed. In particular, the basic structure of the MM polarimeter is described. The interaction of polarized light with cervical tissue in terms of polarimetric parameters such as depolarization and birefringence is discussed. The assessment of cervical pathologies including CIN, cancer, pregnancy, and sPTB with MM polarimetry and the underlying reasons that produce the contrast in optical imaging are outlined. The clinical implementation of MM polarimetry, especially the Müller polarimetry colposcope, is also discussed. Finally, the challenges for MM polarimetry in cervical clinics are also speculated.

Evaluation and Association of Hematological and Biochemical Parameters of Untreated COVID-19 Patients on the Basis of Differences in Ethnicity and Curcumin as a Possible Treatment.

BACKGROUND: CBC (complete blood count) tests, along with RPM (Renal parameters) and LFT (Liver function tests), are clinically important for coronavirus patients; curcumin can serve as a possible treatment for SARS- CoV. OBJECTIVE: The objective of the study was to determine the relationship of CBC parameters with renal parameters and liver function tests and to develop the hypothesis that curcumin may be the best and non-invasive drug for coronavirus. Materials &Methods: The differences between the results of 91 confirmed cases of covid-19 (symptomatic and asymptomatic) and 100 controls were assessed by an independent t-test and Mann-Witney U Wilcoxon test. Microscopy, hematological tools, and techniques were used to assess the improvements/abnormalities in blood components and parameters. RESULTS: This is a case control study along with the feasibility of curcumin as covid treatment. The association between parameters was assessed by Pearson & Spearman correlation analysis. The level of significance was p<0.05. Changes were observed in urea (p=0.000), creatinine (p=0.02), total bilirubin (P=0.000), SGPT (ALT) (p=0.000), RBC (p=0.001), HGB (p=0.001), MCV (p=0.002), MCH (p=0.03), MPV, PDW, NE%, LY%, and MO% EO% (p=0.00), in comparison to normal controls. Differences in the correlation of electrolytes, RPM, and LFT tests along with CBC parameters in Pakistani and Chinese individuals provided a new idea for using various diagnostic and therapeutic tools in different ethnic groups. The covid-19 infected blood components and parameters showed rapid improvement/recovery, especially the total count of platelets and WBCs (lymphocytes and basophils), HGB, HCT, MCV, and MCH. CONCLUSION: Curcumin drugs can be used as an immediate remedy/treatment to cure COVID-19 patients.

Characterization of radiofrequency ablated myocardium with optical coherence tomography.

Certain types of cardiac arrhythmias are best treated with radiofrequency (RF) ablation, in which an electrode is inserted into the targeted area of the myocardium and then RF electrical current is applied to heat and destroy surrounding tissue. The resulting ablation lesion usually consists of a coagulative necrotic core surrounded by a rim region of mixed viable and non-viable cells. The characterization of the RF ablated lesion is of potential clinical importance. Here we aim to elaborate optical coherence tomography (OCT) imaging for the characterization of RF-ablated myocardial tissue. In particular, the underlying principles of OCT and its polarization-sensitive counterpart (PS-OCT) are presented, followed by the knowledge needed to interpret their optical images. Studies focused on real-time monitoring of RF lesion formation in the myocardium using OCT systems are summarized. The design and development of various hybrid probes incorporating both OCT guidance and RF ablation catheters are also discussed. Finally, the challenges related to the transmission of OCT imaging systems to cardiac clinics for real-time monitoring of RF lesions are outlined.

Isolating individual polarization effects from the Mueller matrix: comparison of two non-decomposition techniques.

The prevailing formalisms for isolating individual polarization effects from the experimental Mueller matrix M can be broadly divided into two categories; decomposition of M to derive the individual optical effects and directly associating the individual optical effects to specific elements of M (i.e., non-decomposition techniques). Mueller matrix transformation (MMT) and direct interpretation of Mueller matrix (DIMM) are two popular techniques of the latter category. In this study, these two non-decomposition techniques (i.e., MMT and DIMM) are compared in a detailed quantitative analysis comprising of tissues (n = 53) and phantom (n = 45) samples. In particular, two commonly investigated polarimetric variables (i.e., depolarization and retardance) were calculated from the experimentally measured M using both the non-decomposition (i.e., MMT and DIMM) techniques. The comparison carried out with scatter plots (integrated with the correlation coefficients), violin plots and Bland and Altman plots revealed better agreement of depolarization-related variables (as compared to the retardance) between the two non-decomposition techniques. The comparative analyses presented here would be beneficial for the interpretation of polarimetric variables and optical characterization of turbid media.

Cell refractive index: Models, insights, applications and future perspectives.

Cell refractive index (RI) is an intrinsic optical parameter that governs the propagation of light (i.e., scattering and absorption) in the cell matrix. The RI of cell is sensitively correlated with its mass distribution and thereby has the capability to provide important insights for diverse biological models. Herein, we review the cell refractive index and the fundamental models for measurement of cell RI, summarize the published RI data of cell and cell organelles and discuss the associated insights. Illustrative applications of cell RI in cell biology are also outlined. Finally, future research trends and applications of cell RI, including novel imaging techniques, reshaping flow cytometry and microfluidic platforms for single cell manipulation are discussed. The rapid technological advances in optical imaging integrated with microfluidic regime seems to enable deeper understanding of subcellular dynamics with high spatio-temporal resolution in real time.

Ex vivo characterization of normal and adenocarcinoma colon samples by Mueller matrix polarimetry.

Mueller matrix polarimetry along with polar decomposition algorithm was employed for the characterization of ex vivo normal and adenocarcinoma human colon tissues by polarized light in the visible spectral range (425-725 nm). Six derived polarization metrics [total diattenuation (DT ), retardance (RT ), depolarization(ΔT ), linear diattenuation (DL), retardance (δ), and depolarization (ΔL)] were compared for normal and adenocarcinoma colon tissue samples. The results show that all six polarimetric properties for adenocarcinoma samples were significantly higher as compared to the normal samples for all wavelengths. The Wilcoxon rank sum test illustrated that total retardance is a good candidate for the discrimination of normal and adenocarcinoma colon samples. Support vector machine classification for normal and adenocarcinoma based on the four polarization properties spectra (ΔT , ΔL, RT ,and δ) yielded 100% accuracy, sensitivity, and specificity, while both DTa nd DL showed 66.6%, 33.3%, and 83.3% accuracy, sensitivity, and specificity, respectively. The combination of polarization analysis and given classification methods provides a framework to distinguish the normal and cancerous tissues.