Understanding Deformation and Breakup Tendency of Shear-Thinning Viscoelastic Drops in Constricted Microchannels.

The study of drop deformation in response to various stresses has long piqued the interest of several academics. The deformation behavior of cells, drug carriers, and even drug particles moving via microcapillaries inside the human body can be modeled using a viscoelastic drop model. A drop breakup study can also provide better design guidance for nanocarriers that can deliver on-demand burst drug releases at specific cancer sites. Thus, we attempted to investigate the deformation and breakup of a shear-thinning finitely extensible nonlinear elastic-peterlin (FENE-P) drop moving through the constricted microchannel. The computational simulation suggested that drop deformation and breakup can be manipulated by varying of parameters like channel confinement, Deborah number, solvent viscosity ratio, viscosity ratio, and capillary number. We attempted to find the critical capillary number for initiation of drop breakup. Observations from present study will give valuable insights into deformation and breakup patterns of drug carriers inside constricted microcapillaries. The simulations of the two-phase viscoelastic drop─Newtonian matrix system were performed on an open-source solver, Basilisk.

An unreported case of intraoperative frozen section diagnosis of a sclerosing stromal tumor of the ovary- A report with a review.

ABSTRACT: Sclerosing stromal tumor is a benign sex cord-stromal tumor, that commonly occurs in the second and third decades of age. Intraoperative diagnosis of this entity poses a great challenge because of the rare occurrence and can mimic malignant lesions. A 15-year-old female presented with a right ovarian mass. Serum markers were within normal limits. The radiological evaluation showed a large heterogeneously enhancing solid cystic abdominopelvic mass of size 16 × 14 × 9 cm with non-visualization of both ovaries separately and a few areas of calcification with mild ascites. An open cystectomy was performed. A part of the cyst wall was sent for an intraoperative frozen section. It was reported as sclerosing stromal tumor, and the post-operative specimen also confirmed the same. Areas of calcification and ossification were also identified as additional findings. We reported this case because of the uncommon occurrence, highlighting additional histological features, and also did a literature review, especially focussing on the intra-operative diagnosis.

Transport Behavior of Commercial Anticancer Drug Protein-Bound Paclitaxel (Paclicad) in a Micron-Sized Channel.

Protein-bound paclitaxel has been developed clinically as one of the most successful chemotherapy drugs for the treatment of a wide variety of cancers. However, these medications, due to their nanoscale properties, may often induce capillary blocking while migrating through minute blood vessels. Considering the detrimental impact of this restriction, we investigated the transport of protein-bound paclitaxel, Paclicad, in a 7 µm microchannel mimicking the identical mechanical confinement of the blood capillaries. The drug was reported to migrate through a constricted microchannel without obstruction at a solution flow rate of 20-50 µL/h. The onset of an agglomeration site was observed at higher flow rates of 70-90 µL/h, while complete capillary obstruction was observed at 100 µL/h. The mobility of the particles was also calculated, and the results suggested that the presence of varying cross-sections affects the mobility of the drug particles. The trajectory of the particle migration was observed to be less tortuous at the higher flow rate, but the tortuous nature appeared to increase with the presence of agglomeration sites in the flow field. The experimental results were also compared with the computational model of the drug particle. The drug particle was modeled both as Newtonian and as an FENE-P viscoelastic drop. The drop interface tracking was done by the VOF method using the open source software Basilisk. The particle displacement was better estimated by both the FENE-P and Newtonian model at a flow rate of 30 µL/h, while deviation was observed at a flow rate of 50 µL/h. The FENE-P model was observed to show higher deformation than the Newtonian model at both flow rates. The experimental results provided better insight into the agglomeration tendency of Paclicad, migrating through a constricted microchannel at higher flow rates. The numerical model could be further employed to understand the more complex intravenous transport of drugs.

Utility of Flow Cytometry in Diagnosis of Acute Leukemias: A Study at RIMS, Ranchi, India.

Introduction: Leukemia is a neoplastic disorder originating in a hematopoietic cell that has undergone an intrinsic change, causing it to escape from the normal restraints imposed on proliferative activity. Immunophenotyping is now the preferred method for diagnosing, classifying, staging and monitoring the disease progression as well as response to therapy. Material and Method: The material of the present study consisted of 51 patients suffering from hematological malignancies who attended and /or were admitted in Rajendra Institute of Medical Sciences, Ranchi during the period from March 2018 to August 2019. Results: A total of 51 cases were diagnosed as acute leukemia on microscopic examination. On immunophenotyping, 36 cases (70.6%) were diagnosed as Acute Myeloid Leukemia (AML), 15 cases (29.4%) were diagnosed as Acute Lymphoblastic Leukemia (ALL). ALL cases were further divided into B-Cell ALL and T-Cell ALL with 8 cases (15.7%) and 7 cases (13.7%) respectively. Cytogenetics could not be done for these cases due to non-availability of the set-up for the same at the institute. Conclusion: Flowcytometry can be a great tool in diagnosis and categorisation of leukemia especially at centres where cytogenetics is not available.

Serial Doppler Gradients Are Predictive of Future Bioprosthetic Valve Degeneration.

Doppler echocardiography and color flow imaging are helpful techniques in evaluating the functional status of a bioprosthetic valve. The aim of this study was to determine whether serial Doppler gradients are predictive of future bioprosthetic valve degeneration. We performed serial echo-Doppler studies over a 6-year period (1988-1994) on 228 patients who had undergone mitral (n = 112) or aortic (n = 116) bioprosthetic valve implantation between 1973 and 1994. Thirty-nine mitral prostheses and 30 aortic prostheses became dysfunctional and required reoperation. A serial rise in mean gradient of 5 mmHg or more across the mitral valve and 25 mmHg or more across the aortic valve was significantly associated with increased valve degeneration (odds ratio 3.40 and 16.11 and 95% confidence intervals 1.31 and 8.80 and 13.6 and 72.13 for the mitral and aortic valve, respectively). Both aortic and mitral valves began to degenerate after 8 years. Serial echo-Doppler studies showed a rise in transvalvular gradients around the same time. Closer evaluation for prosthetic valve dysfunction should be considered in patients 8 or more years status post surgery, especially those with high transvalvular gradients.