Dielectric Characterization of Coastal Cartilage Chondrocytes

BACKGROUND: Chondrocytes respond to biomechanical and bioelectrochemical stimuli by secreting appropriate extracellular matrix proteins that enable the tissue to withstand the large forces it experiences. Although biomechanical aspects of cartilage are well described, little is known of the bioelectrochemical responses. The focus of this study is to identify bioelectrical characteristics of human costal cartilage cells using dielectric spectroscopy. METHODS: Dielectric spectroscopy allows non-invasive probing of biological cells. An in house computer program is developed to extract dielectric properties of human costal cartilage cells from raw cell suspension impedance data measured by a microfluidic device. The dielectric properties of chondrocytes are compared with other cell types in order to comparatively assess the electrical nature of chondrocytes. RESULTS: The results suggest that electrical cell membrane characteristics of chondrocyte cells are close to cardiomyoblast cells, cells known to possess an array of active ion channels. The blocking effect of the non-specific ion channel blocker gadolinium is tested on chondrocytes with a significant reduction in both membrane capacitance and conductance. CONCLUSIONS: We have utilized a microfluidic chamber to mimic biomechanical events through changes in bioelectrochemistry and described the dielectric properties of chondrocytes to be closer to cells derived from electrically excitably tissues. GENERAL SIGNIFICANCE: The study describes dielectric characterization of human costal chondrocyte cells using physical tools, where results and methodology can be used to identify potential anomalies in bioelectrochemical responses that may lead to cartilage disorders

The treatment of hyperthyroidism with methimazole in a pregnant who developed agranulocytosis due to propylthiouracil

The most common cause of hyperthyroidism during pregnancy is Graves' disease. Anti-thyroid drugs are primarily used in the treatment of pregnant women with Graves’ disease. Anti-thyroid drugs’ side effects include itching, jaundice, skin rash, drug fever, arthralgia, lupus-like syndrome, toxic hepatitis, vasculitis, hypergammaglobulinemia, and lymphadenopathy.  Although agranulocytosis, a serious side effect of anti-thyroid drugs, is rare, it is difficult to treat when it occurs during pregnancy. In this article, we aimed to present a pregnant case with Graves' disease who developed agranulocytosis after the initiation of propylthiouracil, whose agranulocytosis was treated with granulocyte colony-stimulating factor, and subsequently, hyperthyroidism was treated with methimazole without any problem

DYNAMIC STABILITY ANALYSIS OF LAMINATED CURVED BEAMS

Bu çalışmada, düzlem içerisinde belirli bir eğriliğe sahip tabakalı kompozit dairesel bir yay parçasının, merkez açısının ve tabakalardaki fiber açılarının değişiminin dinamik kararlılığa etkileri sonlu elemanlar metodu kullanılarak araştırılmıştır. Ayrıca birinci doğal frekans ve burkulma yükü değerleri ANSYS programından elde edilen sonuçlarla karşılaştırılmış ve eğri çubuğun merkez açısının, fiber açılarının, statik ve dinamik yük parametresinin kararlılık bölgeleri üzerindeki etkileri grafikler ile gösterilmiştir. In this study, the effects of variations of subtended angle and orientation angle of a laminated curved beam having an in-plane curvature, on the dynamic stability have been investigated by using the Finite Element Method. In addition, the results obtained from this study are compared with the results obtained from ANSYS program for the fundamental natural frequency and critical buckling load. The effects of variations of subtended angle, orientation angle, static and dynamic load parameters on the stability regions are shown in graphics

NATURAL FREQUENCY AND BUCKLING ANALYSIS OF LAMINATED CURVED BEAMS

Bu çalışmada, düzlem içerisinde belirli bir eğriliğe sahip tabakalı kompozit dairesel bir yay parçasının merkez açısının, eğrilik yarıçapının değişiminin ve tabakalardaki fiber açılarının doğal frekans ve burkulma yüküne etkileri sonlu elemanlar metodu kullanılarak araştırılmıştır. Bu analizde kullanılan sonlu eleman modelinin oluşturulması için Sabir ve Ashwell'in yer değiştirme fonksiyonları kullanılmıştır. Geliştirilen modelle elde edilen sonuçlar ANSYS programından elde edilen sonuçlarla karşılaştırılmıştır. In this study, the effects of variations of subtended angle, curvature of a laminated curved beam and orientation angle, having an in-plane curvature, on the natural frequencies and buckling load have been investigated by using the Finite Element Method. Sabir and Ashwell's displacement functions have been used to develop a finite element model to employ in this study. The results obtained with the present element are compared with the results obtained from ANSYS program

Probing Nanoparticle Interactions in Cell Culture Media

Nanoparticle research is often performed in vitro with little emphasis on the potential role of cell culture medium. In this study, gold nanoparticle interactions with cell culture medium and two cancer cell lines (human T-cell leukemia Jurkat and human pancreatic carcinoma PANC1) were investigated. Gold nanoparticles of 10, 25, 50, and 100 nm in diameter at fixed mass concentration were tested. Size distributions and zeta potentials of gold nanoparticles suspended in deionized (DI) water and Dulbecco\u27s Modified Eagle\u27s Media (DMEM) supplemented with fetal calf serum (FCS) were measured using dynamic light scattering (DLS) technique. In DI water, particle size distributions exhibited peaks around their nominal diameters. However, the gold nanoparticles suspended in DMEM supplemented with FCS formed complexes around 100 nm, regardless of their nominal sizes. The DLS and UV-vis spectroscopy results indicate gold nanoparticle agglomeration in DMEM that is not supplemented by FCS. The zeta potential results indicate that protein rich FCS increases the dispersion quality of gold nanoparticle suspensions through steric effects. Cellular uptake of 25 and 50 nm gold nanoparticles by Jurkat and PANC1 cell lines were investigated using inductively coupled plasma-mass spectroscopy. The intracellular gold level of PANC1 cells was higher than that of Jurkat cells, where 50 nm particles enter cells at faster rates than the 25 nm particles

Effects of COVID-19 pandemic lockdown on the metabolic control of type 2 diabetes mellitus in patients

ABSTRACT Objective: The effects of the COVID-19 pandemic on the control of diabetes mellitus in patients are largely unknown. In this study we aimed to analyze the impact of the pandemic and the ensuing lockdown on the management of type 2 diabetes mellitus. Subjects and methods: A total of 7,321patients with type 2 diabetes mellitus (4,501 from the pre-pandemic period, 2,820 from the post-pandemic period) were studied retrospectively. Results: The admission of patients with diabetes melitus (DM) decreased significantly during the pandemic (4,501 pre-pandemic vs. 2,820 post-pandemic; p < 0.001). The mean age of patients was statistically lower (51.5 ± 14.0 vs. 49.7 ± 14.5 years; p < 0.001), and the mean glycated hemoglobin (A1c) level was significantly higher (7.9% ± 2.4% vs. 7.3% ± 1.7%; p < 0.001) in the post-pandemic period than in the pre-pandemic. The female/male ratio was similar in both periods (59.9%/40.1% for pre-pandemic, 58.6%/41.4% for post-pandemic; p = 0.304). As calculated by month the pre-pandemic rate of women was higher only in January (53.1% vs. 60.6%, p = 0.02). Mean A1c levels were higher in the postpandemic period than in the same month of the previous year, excluding July and October (p = 0.001 for November, p < 0.001 for others). Postpandemic patients admitted to the outpatient clinic were significantly younger than prepandemic visits for July (p = 0.001), August (p < 0.001) and December (p < 0.001). Conclusion: The lockdown had detrimental effects on blood sugar management in patients with DM. Hence, diet and exercise programs should be adapted to home conditions, and social and psychological support should be provided to patients with DM

Microfluidic Impedance Spectroscopy as a Tool for Quantitative Biology and Biotechnology

A microfluidic device that is able to perform dielectric spectroscopy is developed. The device consists of a measurement chamber that is 250 μm thick and 750 μm radius. Around 1000 cells fit inside the chamber assuming average quantities for cell radius and volume fraction. This number is about 1000 folds lower than the capacity of conventional fixtures. A T-cell leukemia cell line Jurkat is tested using the microfluidic device. Measurements of deionized water and salt solutions are utilized to determine parasitic effects and geometric capacitance of the device. Physical models, including Maxwell-Wagner mixture and double shell models, are used to derive quantities for sub-cellular units. Clausius-Mossotti factor of Jurkat cells is extracted from the impedance spectrum. Effects of cellular heterogeneity are discussed and parameterized. Jurkat cells are also tested with a time domain reflectometry system for verification of the microfluidic device. Results indicate good agreement of values obtained with both techniques. The device can be used as a unique cell diagnostic tool to yield information on sub-cellular units. (C) 2012 American Institute of Physics

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P &lt; 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely