Evaluating the Ability of Brachial Plexus-Injured Patients to Control an Externally Powered (Myoelectric) Hand Prosthesis.

BACKGROUND: Restoration of hand function after traumatic brachial plexus injury (BPI) remains a formidable challenge. Traditional methods such as nerve or free muscle transfers yield suboptimal results. Advancements in myoelectric prostheses, characterized by novel signal acquisition and improved material technology, show promise in restoring functional grasp. This study evaluated the ability of adults with a BPI injury to control an externally powered prosthetic hand using nonintuitive signals, simulating the restoration of grasp with a myoelectric prosthesis. It also assessed the effectiveness of a comprehensive multidisciplinary evaluation in guiding treatment decisions. METHODS: A multidisciplinary brachial plexus team assessed adults with compromised hand function due to BPI. The feasibility of amputation coupled with fitting of a myoelectric prosthesis for grasp reconstruction was evaluated. Participants' ability to control a virtual or model prosthetic hand using surface electromyography (EMG) as well as with contralateral shoulder motion-activated linear transducer signals was tested. The patient's input and injury type, along with the information from the prosthetic evaluation, were used to determine the reconstructive plan. The study also reviewed the number of participants opting for amputation and a myoelectric prosthetic hand for grasp restoration, and a follow-up survey was conducted to assess the impact of the initial evaluation on decision-making. RESULTS: Of 58 subjects evaluated, 47 (81%) had pan-plexus BPI and 42 (72%) received their initial assessment within 1 year post-injury. Forty-seven patients (81%) could control the virtual or model prosthetic hand using nonintuitive surface EMG signals, and all 58 could control it with contralateral uniscapular motion via a linear transducer and harness. Thirty patients (52%) chose and pursued amputation, and 20 (34%) actively used a myoelectric prosthesis for grasp. The initial evaluation was informative and beneficial for the majority of the patients, especially in demonstrating the functionality of the myoelectric prosthesis. CONCLUSIONS: The study indicates that adults with traumatic BPI can effectively operate a virtual or model myoelectric prosthesis using nonintuitive control signals. The simulation and multidisciplinary evaluation influenced informed treatment choices, with a high percentage of patients continuing to use the myoelectric prostheses post-amputation, highlighting its long-term acceptance and viability. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The Role of Amputation and Myoelectric Prosthetic Fitting in Patients with Traumatic Brachial Plexus Injuries.

BACKGROUND: A cohort of patients with traumatic brachial plexus injuries (BPIs) underwent elective amputation following unsuccessful surgical reconstruction or delayed presentation. The results of amputation with and without a myoelectric prosthesis (MEP) using nonintuitive controls were compared. We sought to determine the benefits of amputation, and whether fitting with an MEP was feasible and functional. METHODS: We conducted a retrospective review of patients with BPI who underwent elective upper-extremity amputation at a single institution. Medical records were reviewed for demographics, injury and reconstruction details, amputation characteristics, outcomes, and complications. Prosthesis use and MEP function were assessed. The minimum follow-up for clinical outcomes was 12 months. RESULTS: Thirty-two patients with BPI and an average follow-up of 53 months underwent elective amputation between June 2000 and June 2020. Among the cases were 18 transhumeral amputations, 12 transradial amputations, and 2 wrist disarticulations. There were 29 pan-plexus injuries, 1 partial C5-sparing pan-plexus injury, 1 lower-trunk with lateral cord injury, and 1 lower-trunk injury. Amputation occurred, on average, at 48.9 months following BPI and 36.5 months following final reconstruction. Ten patients were fitted for an MEP with electromyographic signal control from muscles not normally associated with the intended function (nonintuitive control). Average visual analog scale pain scores decreased post-amputation: from 4.8 pre-amputation to 3.3 for the MEP group and from 5.4 to 4.4 for the non-MEP group. Average scores on the Disabilities of the Arm, Shoulder and Hand questionnaire decreased post-amputation, but not significantly: from 35 to 30 for the MEP group and from 43 to 40 for the non-MEP group. Patients were more likely to be employed following amputation than they were before amputation. No patient expressed regret about undergoing amputation. All patients in the MEP group reported regular use of their prosthesis compared with 29% of patients with a traditional prosthesis. All patients in the MEP group demonstrated functional terminal grasp/release that they considered useful. CONCLUSIONS: Amputation is an effective treatment for select patients with BPI for whom surgical reconstruction is unsuccessful. Patients who underwent amputation reported decreased mechanical pain, increased employment rates, and a high rate of satisfaction following surgery. In amputees with sufficient nonintuitive electromyographic signals, MEPs allow for terminal grasp/release and are associated with high rates of prosthesis use. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Temporal characterization of flowback and produced water quality from a hydraulically fractured oil and gas well.

This study examined water quality, naturally-occurring radioactive materials (NORM), major ions, trace metals, and well flow data for water used and produced from start-up to operation of an oil and gas producing hydraulically-fractured well (horizontal) in the Denver-Julesburg (DJ) Basin in northeastern Colorado. Analysis was conducted on the groundwater used to make the fracturing fluid, the fracturing fluid itself, and nine flowback/produced water samples over 220days of operation. The chemical oxygen demand of the wastewater produced during operation decreased from 8200 to 2500mg/L, while the total dissolved solids (TDS) increased in this same period from 14,200 to roughly 19,000mg/L. NORM, trace metals, and major ion levels were generally correlated with TDS, and were lower than other shale basins (e.g. Marcellus and Bakken). Although at lower levels, the salinity and its origin appear to be the result of a similar mechanism to that of other shale basins when comparing Cl/Br, Na/Br, and Mg/Br ratios. Volumes of returned wastewater were low, with only 3% of the volume injected (11millionliters) returning as flowback by day 15 and 30% returning by day 220. Low levels of TDS indicate a potentially treatment-amenable wastewater, but low volumes of flowback could limit onsite reuse in the DJ Basin. These results offer insight into the temporal water quality changes in the days and months following flowback, along with considerations and implications for water reuse in future hydraulic fracturing or for environmental discharge.

Partitioning of naturally-occurring radionuclides (NORM) in Marcellus Shale produced fluids influenced by chemical matrix.

Naturally-occurring radioactive materials (NORM) associated with unconventional drilling produced fluids from the Marcellus Shale have raised environmental concerns. However, few investigations into the fundamental chemistry of NORM in Marcellus Shale produced fluids have been performed. Thus, we performed radiochemical experiments with Marcellus Shale produced fluids to understand the partitioning behavior of major radioelements of environmental health concern (uranium (U), thorium (Th), radium (Ra), lead (Pb), and polonium (Po)). We applied a novel radiotracer, (203)Pb, to understand the behavior of trace-levels of (210)Pb in these fluids. Ultrafiltration experiments indicated U, Th, and Po are particle reactive in Marcellus Shale produced fluids and Ra and Pb are soluble. Sediment partitioning experiments revealed that >99% of Ra does not adsorb to sediments in the presence of Marcellus Shale produced fluids. Further experiments indicated that although Ra adsorption is related to ionic strength, the concentrations of heavier alkaline earth metals (Ba, Sr) are stronger predictors of Ra solubility.

Understanding the Radioactive Ingrowth and Decay of Naturally Occurring Radioactive Materials in the Environment: An Analysis of Produced Fluids from the Marcellus Shale.

BACKGROUND: The economic value of unconventional natural gas resources has stimulated rapid globalization of horizontal drilling and hydraulic fracturing. However, natural radioactivity found in the large volumes of "produced fluids" generated by these technologies is emerging as an international environmental health concern. Current assessments of the radioactivity concentration in liquid wastes focus on a single element-radium. However, the use of radium alone to predict radioactivity concentrations can greatly underestimate total levels. OBJECTIVE: We investigated the contribution to radioactivity concentrations from naturally occurring radioactive materials (NORM), including uranium, thorium, actinium, radium, lead, bismuth, and polonium isotopes, to the total radioactivity of hydraulic fracturing wastes. METHODS: For this study we used established methods and developed new methods designed to quantitate NORM of public health concern that may be enriched in complex brines from hydraulic fracturing wastes. Specifically, we examined the use of high-purity germanium gamma spectrometry and isotope dilution alpha spectrometry to quantitate NORM. RESULTS: We observed that radium decay products were initially absent from produced fluids due to differences in solubility. However, in systems closed to the release of gaseous radon, our model predicted that decay products will begin to ingrow immediately and (under these closed-system conditions) can contribute to an increase in the total radioactivity for more than 100 years. CONCLUSIONS: Accurate predictions of radioactivity concentrations are critical for estimating doses to potentially exposed individuals and the surrounding environment. These predictions must include an understanding of the geochemistry, decay properties, and ingrowth kinetics of radium and its decay product radionuclides.

Monitoring radionuclides in subsurface drinking water sources near unconventional drilling operations: a pilot study.

Unconventional drilling (the combination of hydraulic fracturing and horizontal drilling) to extract oil and natural gas is expanding rapidly around the world. The rate of expansion challenges scientists and regulators to assess the risks of the new technologies on drinking water resources. One concern is the potential for subsurface drinking water resource contamination by naturally occurring radioactive materials co-extracted during unconventional drilling activities. Given the rate of expansion, opportunities to test drinking water resources in the pre- and post-fracturing setting are rare. This pilot study investigated the levels of natural uranium, lead-210, and polonium-210 in private drinking wells within 2000 m of a large-volume hydraulic fracturing operation--before and approximately one-year following the fracturing activities. Observed radionuclide concentrations in well waters tested did not exceed maximum contaminant levels recommended by state and federal agencies. No statistically-significant differences in radionuclide concentrations were observed in well-water samples collected before and after the hydraulic fracturing activities. Expanded monitoring of private drinking wells before and after hydraulic fracturing activities is needed to develop understanding of the potential for drinking water resource contamination from unconventional drilling and gas extraction activities.

A simple-rapid method to separate uranium, thorium, and protactinium for U-series age-dating of materials.

Uranium-series dating techniques require the isolation of radionuclides in high yields and in fractions free of impurities. Within this context, we describe a novel-rapid method for the separation and purification of U, Th, and Pa. The method takes advantage of differences in the chemistry of U, Th, and Pa, utilizing a commercially-available extraction chromatographic resin (TEVA) and standard reagents. The elution behavior of U, Th, and Pa were optimized using liquid scintillation counting techniques and fractional purity was evaluated by alpha-spectrometry. The overall method was further assessed by isotope dilution alpha-spectrometry for the preliminary age determination of an ancient carbonate sample obtained from the Lake Bonneville site in western Utah (United States). Preliminary evaluations of the method produced elemental purity of greater than 99.99% and radiochemical recoveries exceeding 90% for U and Th and 85% for Pa. Excellent purity and yields (76% for U, 96% for Th and 55% for Pa) were also obtained for the analysis of the carbonate samples and the preliminary Pa and Th ages of about 39,000 years before present are consistent with (14)C-derived age of the material.

Nitric oxide produced by cytochrome c oxidase helps stabilize HIF-1α in hypoxic mammalian cells.

The mitochondrial respiratory chain has been reported to play a role in the stabilization of HIF-1α when mammalian cells experience hypoxia, most likely through the generation of free radicals. Although previous studies have suggested the involvement of superoxide catalyzed by complex III more recent studies raise the possibility that nitric oxide (NO) catalyzed by cytochrome c oxidase (Cco/NO), which functions in hypoxic signaling in yeast, may also be involved. Herein, we have found that HEK293 cells, which do not express a NOS isoform, possess Cco/NO activity and that this activity is responsible for an increase in intracellular NO levels when these cells are exposed to hypoxia. By using PTIO, a NO scavenger, we have also found that the increased NO levels in hypoxic HEK293 cells help stabilize HIF-1α. These findings suggest a new mechanism for mitochondrial involvement in hypoxic signaling in mammalian cells.

Microbiological Water Quality Monitoring in a Resource-Limited Urban Area: a Study in Cameroon; Africa

In resource-limited developing nations; such as Cameroon; the expense of modern water-quality monitoring techniques is prohibitive to frequent water testing; as is done in the developed world. Inexpensive; shelf-stable 3MT PetrifilmT Escherichia coli/Coliform Count Plates potentially can provide significant opportunity for routine water-quality monitoring in the absence of infrastructure for state-of-the-art testing. We used shelf-stable E. coli/coliform culture plates to assess the water quality at twenty sampling sites in Kumbo; Cameroon. Culture results from treated and untreated sources were compared to modern bacterial DNA pyrosequencing methods using established bioinformatics and statistical tools. Petrifilms were reproducible between replicates and sampling dates. Additionally; cultivation on Petrifilms suggests that treatment by the Kumbo Water Authority (KWA) greatly improves water quality as compared with untreated river and rainwater. The majority of sequences detected were representative of common water and soil microbes; with a minority of sequences (40) identified as belonging to genera common in fecal matter and/or causes of human disease. Water sources had variable DNA sequence counts that correlated significantly with the culture count data and may therefore be a proxy for bacterial load. Although the KWA does not meet Western standards for water quality (less than one coliform per 100 mL); KWA piped water is safer than locally available alternative water sources such as river and rainwater. The culture-based technology described is easily transferrable to resource-limited areas and provides local water authorities with valuable microbiological safety information with potential to protect public health in developing nations