A dual mode pulsed electro-magnetic cell stimulator

Title from PDF of title page, viewed on March 13, 2013Thesis advisor: Walter D. León SalasVitaIncludes bibliographic references (p. 96-97)Thesis (M.S.)--School of Computing and Engineering. University of Missouri--Kansas City, 2012This thesis presents the design and test of a dual-modality cell stimulator. The stimulator generates pulsing electric and magnetic fields at programmable rates and intensities. The target application is the stimulation of bone and muscle cells. While electric and magnetic stimulators have been reported before, this is the first device that combines both modalities. The ability of the dual stimulation to target bone and muscle tissue simultaneously has the potential to improve the therapeutic treatment of osteoporosis and sarcopenia. The device is fully programmable and easy to use and can run from a battery or a power supply. In-vitro tests show a 4% increase in protein synthesis 24 hours after the stimulation. These levels are comparable to heat shock stimulation.Introduction -- Hardware design -- Firmware design -- Device operation -- Measurements and data -- Conclusions and future work -- Appendix A. MSP430FG439 functional diagram -- Appendix B. Firmware C Code -- Appendix D. Serial communications user interface menu outpu

Hyperthermia Induces Functional and Molecular Modifications in Cardiac, Smooth and Skeletal Muscle Cells

Comparative Medicine - OneHealth and Comparative Medicine Poster SessionHyperthermia is used for the treatment of a number of diseases, including muscle injuries, inflammations, tendinitis, and osteoarticular disorder. More recently, hyperthermia has been used as an adjuvant in cancer treatment. Only two studies have shown that hyperthermia leads to hypertrophy in in-vitro models of cardiac and skeletal muscle cells. Functional, biochemical and molecular mechanisms of hyperthermia-induced hypertrophy in muscles remain largely undiscovered. We investigated the effects of mild heat shock (HS) on C2C12 skeletal, HL-1 cardiac and AR-75 smooth muscle cells. Mild HS (20 min 43ºC) induced increases in the cell area in all muscle cells tested. C2C12 cells are a well-accepted model of skeletal muscle fibers, and were selected for complementary studies. First, to biochemically confirm an increase in protein synthesis we measured and found an increase of ~6% in total protein content 24 hrs after HS. Second, we examined potential modifications in calcium (Ca) homeostasis regulation by measuring intracellular Ca. We detected a lower resting level of intracellular Ca and smaller and longer caffeine-induced Ca transients in C2C12 muscle cells 24 hrs after HS. Next, to search for molecular mechanisms involved with HS-induced hypertrophy and calcium homeostasis modifications, mRNA from C2C12 muscle cells was analyzed at different time points after HS (0, 1, 2, and 24 hrs). We used an ABI Step One Plus RT2 PCR Array System and a custom-built 96 gene array. We report for the first time that the expression of key heat-shock, hypertrophy/ metabolic, and Ca+2 signaling genes were altered after HS. Hsp70 and Hsp72 genes were highly expressed (211-1829 fold change) after HS. Also, Myh7 (MHC-I), Myh6, Srf, Ppp3r1 and Pck1 were up-regulated by 2-6 fold change compared with control cells.. Furthermore, a reduction in the expression of RyR and Trdn genes was observed (2- 3.6 fold change) with an associated increase in the expression of IP3R genes (2-4 fold change). These results indicate that hyperthermia modulates not only heat-shock related and hypertrophy genes, but also genes involved with metabolism, apoptosis repression, calcium homeostasis and signaling, and cell homeostasis. Our studies offer an initial exploration of the functional, biochemical and molecular mechanisms that may help explain the beneficially adaptive effects of hyperthermia on muscle function. Our studies shall also prove useful for the refinement of a specific device (EM-Stim) to be employed for the treatment of muscle and bone diseases (See poster by Hatem et al). Importantly, our studies have potential translational applications. By learning how to more precisely use hyperthermia to control specific genes that can improve or treat muscle injuries, musculoskeletal, and cardiovascular diseases, the ensuing benefits shall be unmistakable. Our short and long-term goals are: i) optimize our protocols; ii) test HS in animal models; iii) manipulate expression of promising genes of interest in vitro and in in-vivo animal models; iv) initiate clinical studies to fully translate from the bench to the bed-side

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

An Electro-magnetic cell stimulator [abstract]

Biomedical Tissue Engineering, Biomaterials, and Medical Devices Poster SessionA device to stimulate bone and muscle cell growth and possibly for treatment of bone and muscle injuries is presented. The device, called EStim, generates electric and magnetic pulses at programmable intervals. This device will also be used to study the crosstalk between bone and muscle cell growth. In a human or animal body, muscles and bones are intimately interrelated and the loss of activity in one of them affects the other. This interrelation is especially evident in persons with bone fractures. While the bone is healing, the muscles loose mass due to lack of exercise. Furthermore, when skeletal muscles are not exercised, bone mass decreases. In these situations, muscle mass can be partially maintained if externally stimulated by applying repetitive electric pulses. The EStim has been designed to generate electric pulses of different frequencies and amplitudes to stimulate muscle growth. It also generates magnetic pulses to stimulate bone growth. This dual stimulation is a unique feature of the EStim and makes it a promising device in the treatment of bone fractures or for muscle stimulation. Besides this clinical application, the EStim is being used to study the crosstalk at the cellular level between muscle and bone cells. A line of C2C12 cells is being used to test the effects of the electric and magnetic pulses on cell growth. Variables such as pulse repetition, field strength and rest period duration have been evaluated. Initial results show that electric stimulation induces cell hypertrophy similar to the ones observed in heat shock experiments (see abstract by Romero et al). The EStim device consists of three sections: the controller, the high-voltage generation unit and the high-current generation unit. The controller is built around the MSP430 low-power microcontroller. It handles communication with a host computer to change settings or to perform tests. Settings such as pulse repetition, pulse width, number of pulses, rest time between pulses, and magnetic field strength can be changed by the user. The controller also monitors the battery voltage and the maximum pulse current. As a safety measure, pulse generation is stopped if the current through the probe exceeds a preset value. The high-voltage generation unit consists of a boost converter that is able to generate voltages up to 40 V and an H-bridge that allows the generation of biphasic or monophasic electric pulses. The high-current unit consists of a buck converter able to generate currents up to 10 A. These large currents are used to generate magnetic fields of up to 10 mT. This device will be used to better understand the interplay between bones and muscles. Ultimately, our goal is test this device in animals and humans to fully realize its applications on musculoskeletal injuries and diseases