An experimental study to test the efficacy of Mesenchymal Stem Cells in reducing corneal scarring in an ex-vivo organ culture model.

In this study, we evaluated the effect of placenta-derived Mesenchymal Stem Cells (MSCs) versus placebo in improving corneal transparency following experimental injury in an ex-vivo organ culture model of post-mortem human corneas. We also compared the influence of MSCs on the basic histopathology of the cornea and the immunohistochemistry markers of fibrotic corneal scarring. Mesenchymal Stem Cells extracted from the placenta were isolated and expanded in-vitro. Five pairs of post-mortem human corneas harvested for the corneal transplant of equal grade were included in the study. Corneas of the same pair were randomly assigned to either the case arm or the control arm. All corneas underwent a standardized superficial keratectomy, 4 mm in diameter. The case and control arm corneas received an intrastromal injection of MSCs and placebo respectively. The corneal button was maintained in an organ culture system for 28 days under the standard protocol. Laser light was passed through the corneas mounted on a self-styled modified artificial anterior chamber. Image analysis was used to quantify corneal transparency. Haematoxylin & Eosin staining and Immunohistochemistry was done for Alpha SMA (Smooth Muscle Actin). Laser scatter measurements were measured using Image Analysis (Image J Software). The difference in the mean of Full-Width Half Maximum (FWHM), Max intensity and Red pixel intensity between the cases and the controls was 101.5, 16.3 and 11.4 respectively which was found to be statistically significant (P < 0.05). Histopathology showed a disorganized Bowman's layer in the controls as compared to the cases. Alpha Smooth Muscle Actin at the injury site stained 3 + in all controls as compared to 1 + in the cases, showing a statistically significant difference (p = 0.005). Based on our findings, we consider that placenta-derived Mesenchymal Stem Cells can alter evolving corneal scarring into a more favourable outcome with better corneal transparency and lesser fibrotic corneal scarring.

The utility of indocyanine green (ICG) for the identification and assessment of viability of the parathyroid glands during thyroidectomy.

We conducted this study to evaluate the ability of indocyanine green (ICG) and near infra-red fluorescence (NIRF) camera to aid in the identification and assessment of viability of parathyroid glands during thyroid surgery. A prospective observational study was conducted between May and October 2020 among 50 consecutive patients who underwent total thyroidectomy at a single institution. Parathyroid glands were identified under white light during thyroidectomy following which reconstituted ICG was injected through a peripheral vein and the location of parathyroid glands was confirmed. The perfusion to the parathyroid gland was assessed by documenting the fluorescence intensity score (FIS) and the parathyroid angiogram score (PAS). There was no difference in the number of parathyroid glands seen on visual inspection 147 (73.5%) when compared to under NIRF camera, 146 (73%). Though the rate of postoperative hypoparathyroidism was lower in the cohort with FIS 3 (14.2%) compared to score 2 and 1 (28.5% and 100%, respectively), this was not significant (p = 0.35). A significant correlation was noted between a delayed flow on PAS and the development of post-thyroidectomy hypoparathyroidism (p = 0.01). PAS had a sensitivity of 100%, specificity of 88.6%, NPV of 100% and PPV of 55.6% to predict the development of post-thyroidectomy hypoparathyroidism. In this study, there was no additional benefit of ICG and NIRF camera in the identification of parathyroid glands. However, ICG angiogram seems to be a good adjunct for the intraoperative assessment of the viability of the parathyroid glands and accurately predicts the development of postoperative hypoparathyroidism.

Microfluidic nanomaterials: From synthesis to biomedical applications.

Microfluidic platforms gain popularity in biomedical research due to their attractive inherent features, especially in nanomaterials synthesis. This review critically evaluates the current state of the controlled synthesis of nanomaterials using microfluidic devices. We describe nanomaterials' screening in microfluidics, which is very relevant for automating the synthesis process for biomedical applications. We discuss the latest microfluidics trends to achieve noble metal, silica, biopolymer, quantum dots, iron oxide, carbon-based, rare-earth-based, and other nanomaterials with a specific size, composition, surface modification, and morphology required for particular biomedical application. Screening nanomaterials has become an essential tool to synthesize desired nanomaterials using more automated processes with high speed and repeatability, which can't be neglected in today's microfluidic technology. Moreover, we emphasize biomedical applications of nanomaterials, including imaging, targeting, therapy, and sensing. Before clinical use, nanomaterials have to be evaluated under physiological conditions, which is possible in the microfluidic system as it stimulates chemical gradients, fluid flows, and the ability to control microenvironment and partitioning multi-organs. In this review, we emphasize the clinical evaluation of nanomaterials using microfluidics which was not covered by any other reviews. In the future, the growth of new materials or modification in existing materials using microfluidics platforms and applications in a diversity of biomedical fields by utilizing all the features of microfluidic technology is expected.

Time to Revisit a Low-Cost Alternative? Palpation Assessment Nerve Monitoring (PANM) for Recurrent Laryngeal Nerve to Predict Postoperative Vocal Cord Function-a Validation Study Using an In-House Neuromonitoring Device.

Neuromonitoring has proved to be a useful technique in reducing nerve injury during thyroid surgery; however, costs continue to limit its use in resource-constrained settings. This study was done to assess the functional integrity of the recurrent laryngeal nerve (RLN) during thyroid surgery using palpation assessment of posterior cricoarytenoid muscle twitch in response to RLN stimulation. Between August 2016 and July 2017, 24 patients with 47 nerves at risk (NARs) underwent thyroid surgery with visual identification and testing of 44 RLNs. The functional integrity of the RLN was checked by stimulation of the RLN. Intraoperative assessment showed 100% sensitivity and positive predictive value in predicting postoperative vocal cord function. The postoperative vocal cord assessment confirmed all 44 nerves tested to be normally functioning. The mean (standard deviation) peak-to-peak amplitude and latency of the CMAP were 0.889 (0.740)/1.336 (1.660) mV and 2.295 (0.319)/2.217 (0.393) ms for left/right side NARs, respectively, with no statistically significant difference (P > 0.05). Palpation assessment of the posterior cricoarytenoid muscle provides a simple and reliable technique for confirming integrity of the RLN. Combining palpation assessment with CMAP from the inferior constrictor muscle may help reduce potential false negative results. With the use of our in-house built device which is significantly cheaper than the commercial ones, this could be considered a low-cost alternative to current established techniques.

A versatile stretch sensor for measuring physiological movement using a centre loaded, end-supported load cell.

Acquisition of movement of some body parts can provide important physiological information. In clinical practice as well as for research purposes different types of sensors such as piezoelectric crystals, conductive rubber and optical displacement sensors are used for such measurements. Each of these sensors is associated with its problems. This paper discusses the use of a stretch sensor constructed using a small metal bar, approximately the size of a zipper slider that can be sewn into a fabric in the form of a belt. A combination of elastic, and Velcro material attached to the metal bar, provides a sensor that is capable of linear, steady state measurement as well as rapid response detecting slow and fast movement of the target. Incorporating the sensor in an elastic belt, allows measurement of physiological movements such as respiratory chest movements, abdominal and limb movements. This paper also discusses the potential use of the novel stretch sensor in measuring change in calf circumference during different manoeuvres, making it a useful assessment tool for calf venous function.

A simple method for quantitative assessment of elbow flexion strength.

Assessment of elbow flexion strength is an important component of upper limb neurological examination and is necessary for patient screening, planning of surgical interventions and rehabilitation. Medical Research Council (MRC) Scale is the most widely used method for grading muscle strength. The major drawback of MRC grading is that it is observer dependent and imprecise. A quantitative measure of elbow flexion strength is an objective measure that eliminates such bias. Several instruments have been developed for quantifying the elbow flexion power. However, availability, quality and measuring standards vary widely between these instruments most being cumbersome and expensive. We report the design of an instrument that is simple and cost effective for quantifying elbow flexion strength objectively. The validity of elbow flexion strength obtained from normal participants using this in-house instrument supports its clinical use in patients with brachial plexus injury.