Tamoxifen Upregulates Collagenase Gene Expression in Human Dermal Fibroblasts.

Background: Tamoxifen is a known inhibitor of fibroblast transforming growth factor beta biosynthesis and wound scar formation. Tamoxifen is also known to be an estrogen antagonist and protein kinase C (PKC) inhibitor. Cells treated with tamoxifen and other PKC/calmodulin inhibitors depolymerize their membrane focal adhesion complexes and cytoskeletal protein structures. These effects result in substrate detachment, cell shape rounding, and upregulation of collagenase synthesis and extracellular matrix degradation. The purpose of our study was to test the hypothesis that tamoxifen treatment of human foreskin fibroblasts results in alteration of cytoskeletal protein organization, cell detachment and rounding, and increased collagenase synthesis similar to known PKC/calmodulin inhibitors such as H-7. Methods: We characterized the effects of PKC/calmodulin inhibitors tamoxifen and H-7 on human dermal fibroblast morphology, cytoskeletal protein organization, and collagenase gene expression in monolayer culture and within collagen gels. Results: We found that fibroblasts responded to tamoxifen by initiation of actin filament depolymerization followed by alteration from spindle to spheroidal shapes. This change in cell shape led to increased collagenase synthesis in cells treated with either tamoxifen or H-7 compared with controls. There was also a 23% increase of hydroxyproline release from tamoxifen-treated fibroblast-populated collagen matrices. Conclusions: Tamoxifen may reduce scarring by inhibiting fibroblast PKC/calmodulin activity, which down-regulates pro-fibrotic transforming growth factor beta signaling and upregulates collagenase production. These effects mimic those of the known PKC/calmodulin inhibitor H-7. Overall, these findings suggest that tamoxifen and its analogues are promising agents for clinical investigation as small molecule regulators of fibrosis and scarring disorders.

Pain Influences Neuropsychological Performance Following Electrical Injury: A Cross-Sectional Study.

OBJECTIVE: Electrical injury (EI) is a significant, multifaceted trauma often with multi-domain cognitive sequelae, even when the expected current path does not pass through the brain. Chronic pain (CP) research suggests pain may affect cognition directly and indirectly by influencing emotional distress which then impacts cognitive functioning. As chronic pain may be critical to understanding EI-related cognitive difficulties, the aims of the current study were: examine the direct and indirect effects of pain on cognition following EI and compare the relationship between pain and cognition in EI and CP populations. METHOD: This cross-sectional study used data from a clinical sample of 50 patients with EI (84.0% male; Mage = 43.7 years) administered standardized measures of pain (Pain Patient Profile), depression, and neurocognitive functioning. A CP comparison sample of 93 patients was also included. RESULTS: Higher pain levels were associated with poorer attention/processing speed and executive functioning performance among patients with EI. Depression was significantly correlated with pain and mediated the relationship between pain and attention/processing speed in patients with EI. When comparing the patients with EI and CP, the relationship between pain and cognition was similar for both clinical groups. CONCLUSIONS: Findings indicate that pain impacts mood and cognition in patients with EI, and the influence of pain and its effect on cognition should be considered in the assessment and treatment of patients who have experienced an electrical injury.

Peroxidation of tetronic 1107 reduces protein chaperone effect.

To enhance the stability of protein therapeutics, pharmaceutical companies have long used various copolymer surfactants as excipients. They act to stabilize proteins by adhering to the hydrophobic surface of the protein preventing denaturation and aggregation. However, some commonly used excipients possess polyoxyalkylene chains that are susceptible to oxidative degradation while in aqueous solution. We postulate that oxidation reactions involving the hydrophobic domains reduce the surfactant's ability to stabilize the native protein structure. We investigated the effect of UV (λ = 254 nm) radiated poloxamine T1107 (T1107) on its ability to disaggregate DTT denatured hen egg-white lysozyme (HEWL). Peroxidation of UV irradiated T1107 was analyzed using FTIR spectroscopy, the Fe+2to Fe+3ion reduction assay method, and1H NMR. Our results indicate that increased UV irradiation led to structural changes in T1107, specifically the addition of a carbonyl on the formate group. The structural change decreased T1107's ability to disaggregate HEWL thus supporting our hypothesis. These results indicate that peroxide content is an important parameter to control in polyoxyalkylene-based excipients.

Hidden realities of electrical injuries.

ABSTRACT: The clinical spectrum of electrical injury ranges from the absence of any external physical signs to severe and life-threatening trauma. This article discusses the fundamental concepts and misunderstandings surrounding electrical injuries and the best practices for evaluation and treatment.

Establishing the base rate of performance invalidity in a clinical electrical injury sample: Implications for neuropsychological test performance.

Objective: The base rate of neuropsychological performance invalidity in electrical injury, a clinically-distinct and frequently compensation-seeking population, is not well established. This study determined the base rate of performance invalidity in a large electrical injury sample, and examined patient characteristics, injury parameters, and neuropsychological test performance based on validity status.Method: This cross-sectional study included data from 101 patients with electrical injury consecutively referred for post-acute neuropsychological evaluation. Eighty-five percent of the sample was compensation-seeking. Multiple performance validity tests (PVTs) were administered as part of standard clinical evaluation. For patients with four or more PVTs, valid performance was operationalized as less than or equal to one PVT failure and invalid performance as two or more failures.Results: Frequency analysis revealed 66% (n = 67) had valid performance while 29% (n = 29) demonstrated probable invalid performance; the remaining 5% (n = 5) had indeterminate validity. No significant differences in demographics or injury parameters emerged between validity groups (0 vs. 1 vs. ≥2 PVT failures). In contrast, the electrical injury group with invalid performance performed significantly worse across tests of processing speed and executive abilities than those with valid performance (ps< .05, ηp2 = .19-.25).Conclusions: The current study is the first to establish the base rate of neuropsychological performance invalidity in electrical injury survivors using empirical methods and current practice standards. Patient and clinical variables, including compensation-seeking status, did not differ between validity groups; however, neuropsychological test performance did, supporting the need for multi-method, objective performance validity assessment.

The relationship between neuropsychological dispersion, processing speed and memory after electrical injury.

Introduction: Previous studies of neuropsychological performance in electrical injury (EI) patients have produced evidence of deficits in various cognitive domains, but studies have yet to investigate relationships among performance in cognitive domains post-EI. This study examined whether dispersion among neuropsychological test scores was associated with injury parameters and neuropsychological performance in EI patients. Additionally, we examined whether dispersion, processing speed and/or executive abilities explain variance in episodic verbal and visual memory performance among EI patients.Method: Data from 52 post-acute EI patients undergoing outpatient evaluation with objectively-verified valid neuropsychological test performance were examined. Tests included measures of verbal and visual memory, processing speed, and executive functioning. Dispersion was calculated from executive functioning and processing speed scores.Results: Dispersion was not related to mean performance or injury characteristics, but was significantly negatively correlated with performance on a test of processing speed, suggesting that increased dispersion is associated with reduced cognitive efficiency post-EI. Delayed visual memory was related to both dispersion scores and processing speed. Stepwise regression equations predicting delayed memory determined that processing speed most significantly predicted delayed visual memory, even after controlling for immediate visual memory. No significant relationships emerged between verbal memory and non-memory neuropsychological scores.Conclusions: This is the first study to examine neuropsychological dispersion and relationships among domains of cognitive functioning in EI. Current results suggested that neuropsychological dispersion is not a marker of general functioning or severity of injury in EI patients, but may represent more specific processing speed abilities. Processing speed predicts delayed visual memory performance in EI patients, which should be considered in interpreting test scores during evaluations.

Scalpel edge roughness affects post-transection peripheral nerve regeneration.

BACKGROUND: Gentle and precise tissue dissection reduces collateral tissue damage and preserves its structural quality for optimizing healing. This is particularly true for peripheral nerve neurorrhaphy. Axon regeneration kinetics across the repair is dependent on the amount of intraneural fibrosis. The purpose of this study was to determine whether scalpel blade smoothness was a deterministic factor in the kinetics of postneurorrhaphy peripheral axon regeneration. METHODS: Scalpel transection of the saphenous nerve was performed in 18 female Hartley guinea pigs either by a standard #15 stainless steel scalpel blade or a highly polished version of the same blade. Compound nerve action potential recordings and histochemical assay of neurofilament density proximal and 1 cm distal to the site of nerve transection were quantified postneurorrhaphy at postoperative weeks 5, 9, and 12. RESULTS: There was no action potential transmission observed in the distal axons immediately after neurorrhaphy. A substantial acceleration of axonal conduction recovery was observed in nerves transected with polished scalpel blades observed by high compound nerve action potential amplitudes at postneurorrhaphy weeks 5 and 9 (P < .05). In addition, an increased recovery of intra-axonal neurofilament density in nerves transected with polished scalpel blades was observed by postoperative week 5 (P < .05). CONCLUSION: The quality of the scalpel blade is an important determinate of postsurgical healing. Gentle handling of tissue matters.

Vitamin D Clinical Pharmacology: Relevance to COVID-19 Pathogenesis.

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Electromuscular Incapacitation Current Induced Neuromuscular Tissue Injury.

Electrical stun devices (ESDs) serve a basic role in law enforcement and provide an alternative to lethal options for target control by causing electromuscular incapacitation (EMI). A fundamental concern is the adverse health consequences associated with their use. The capability of EMI electric field pulses to disrupt skeletal muscle cells (i.e. rhabdomyolysis) was investigated over the operational range commonly used in commercial EMI devices. Functional and structural alteration and recovery of muscle and nerve tissue were assessed. In an anesthetized swine model, the left thigh was exposed to 2 min of electrical pulses, using a commercially available ESD or a custom-made EMI signal power amplifier. Serum creatinine phosphokinase (CPK), troponin, aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) levels were monitored intermittently for 6 h post-EMI exposure. A standard external cardiac defibrillator served as a positive control. Muscle and nerve tissue histology adjacent to the EMI contacts were examined. Post-EMI shock skeletal muscle function was evaluated by analyzing the compound muscle action potentials (CMAPs) of the rectus femoris muscle. Maximal energy cardiac defibrillator pulses resulted in rhabdomyolysis and marked elevation of CPK, LDH, and AST 6 h post-shock. EMI field pulses resulted in the animals developing transient acidosis. CMAP amplitudes decreased approximately 50% after EMI and recovered to near-normal levels within 6 h. Within 6 h post-EMI exposure, blood CPK was mildly increased, LDH was normal, and no arrhythmia was observed. Minimal rhabdomyolysis was produced by the EMI pulses. These results suggest that EMI exposure is unlikely to cause extremity rhabdomyolysis in normal individuals. Bioelectromagnetics. © 2020 Bioelectromagnetics Society.

Examination of the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) validity and substantive scales in patients with electrical injury.

Objective: Electrical injury (EI) is a distinct subtype of traumatic injury that often results in a unique constellation of cognitive sequelae and unusual sensory experiences due to peripheral nervous system injury that are uncommon in general medical/neurological populations and have been unexplored with the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF). Method: This study examined performance patterns on MMPI-2-RF validity and substantive scales among 62 EI patients who underwent neuropsychological evaluation, of which 46 demonstrated valid symptom reporting and neurocognitive test performance via multiple independent validity indicators and were retained for analysis. Results: Valid EI patients scored significantly higher than the MMPI-2-RF normative sample on several validity scales with the largest effect sizes on F-r (Infrequent Responses), Fs (Infrequent Somatic Responses), FBS-r (Symptom Validity), and RBS (Response Bias), and ≥33% obtaining elevated scores on these scales per standard interpretive criteria. Review of item content on these scales revealed several reflect disturbances in sensation, physical functioning, and/or cognition that are not infrequent in this population. Further, MMPI-2-RF clinical profiles did not reveal generalized distress or noncredible over-reporting. Rather, similar to the MMPI-2, valid EI patients had a specific pattern related to physical/sensory symptoms and reduced positive emotions with elevations on restructured clinical (RC) scale 1 (somatic complaints), somatic/cognitive specific problem scales, and low positive emotions (RC2). Conclusions: Elevations on some MMPI-2-RF validity scale may capture some degree of actual EI sequela that neuropsychologists need to consider to prevent erroneously concluding that a credible EI patient is over-reporting when s/he is reporting bona fide, EI-related symptoms.

Amphiphilic copolymers reduce aggregation of unfolded lysozyme more effectively than polyethylene glycol.

Certain amphiphilic block copolymers are known to prevent aggregation of unfolded proteins. To better understand the mechanism of this effect, the optical properties of heat-denatured and dithiothreitol reduced lysozyme were evaluated with respect to controls using UV-Vis spectroscopy, transmission electron microscopy (TEM) and circular dichroism (CD) measurements. Then, the effects of adding Polyethylene Glycol (8000 Da), the triblock surfactant Poloxamer 188 (P188), and the tetrablock copolymer Tetronic 1107 (T1107) to the lysozyme solution were compared. Overall, T1107 was found to be more effective than P188 in inhibiting aggregation, while PEG exhibited no efficacy. TEM imaging of heat-denatured and reduced lysozymes revealed spherical aggregates with on average 250-450 nm diameter. Using CD, more soluble lysozyme was recovered with T1107 than P188 with ß-sheet secondary structure. The greater effectiveness of the larger T1107 in preventing aggregation of unfolded lysozyme than the smaller P188 and PEG points to steric hindrance at play; signifying the importance of size match between the hydrophobic region of denatured protein and that of amphiphilic copolymers. Thus, our results corroborate that certain multi-block copolymers are effective in preventing heat-induced aggregation of reduced lysozymes and future studies warrant more detailed focus on specific applications of these copolymers.

The Pentablock Amphiphilic Copolymer T1107 Prevents Aggregation of Denatured and Reduced Lysozyme.

Aggregation of denatured or unfolded proteins establishes a large energy barrier to spontaneous recovery of protein form and function following traumatic injury, tissue cryopreservation, and biopharmaceutical storage. Some tissues utilize small heat shock proteins (sHSPs) to prevent irreversible aggregation, which allows more complex processes to refold or remove the unfolded proteins. It is postulated that large, amphiphilic, and biocompatible block copolymers can mimic sHSP function. Reduced and denatured hen egg white lysozyme (HEWL) is used as a model aggregating protein. The poloxamine T1107 prevents aggregation of HEWL at 37 °C by three complimentary measures. Structural analysis of denatured HEWL reveals a partially folded conformation with preserved or promoted beta-sheet structures only in the presence of T1107. The physical association of T1107 with denatured HEWL, and the ability to prevent aggregation, is linked to the critical micelle temperature of the polymer. The results suggest that T1107, or a similar amphiphilic block copolymer, can find use as a synthetic chaperone to augment the innate molecular repair mechanisms of natural cells.

Psychiatric Outcome Over a Decade After Electrical Injury: Depression as a Predictor of Long-Term Adjustment.

Electrical injury (EI) produces a variety of physical, cognitive, and emotional consequences. Psychiatric and neurocognitive symptoms may complicate survivors' psychosocial adjustment and ability to return to work. However, due to a paucity of longitudinal research, the long-term course of EI remains poorly understood. The purpose of this study was to investigate psychiatric and functional status in EI patients over a decade after injury. Fourteen EI patients who originally underwent baseline neuropsychological evaluation participated in this long-term follow-up. Participants completed a telephone survey of functional status, neuropsychological symptom checklist, and the Psychosocial Adjustment to Illness Scale Self-Report. Participants were grouped according to baseline Beck Depression Inventory (BDI) scores. After an average of 12.36 years postinjury, participants with elevated baseline BDI scores experienced difficulty across multiple domains of psychosocial adjustment at follow-up. This group was also less likely to return to work and exhibited a significant increase in psychological distress. EI results in significant chronic psychiatric complaints for many survivors. In the current sample, psychiatric sequelae of EI continue to persist over a decade after injury. Moreover, elevated baseline BDI scores predicted worse outcomes for vocational and psychosocial adjustment. Findings underscore the impact of emotional symptoms on recovery and need for specialized psychiatric intervention immediately following injury.

Mood and cognition after electrical injury: a follow-up study.

Individuals who have experienced an electrical injury have been reported to demonstrate both acute and delayed cognitive and psychiatric symptoms. The present study assessed 20 electrically injured patients who underwent neuropsychological evaluations twice following their injury. Time since injury, time between assessments, and longitudinal mood changes were evaluated for their potential impact on simple and complex attention outcomes. As an overall group, there was little change over time from low average to average baseline attention/concentration performance. However, results indicated that longitudinal increases in depressive symptoms were consistently associated with poorer performance on a measure of simple and complex attention. Loss of consciousness, litigation status, baseline injury status (acute vs. post-acute), and time between evaluations were not significant predictors of changes in cognitive performance. Implications for the treatment of comorbid psychiatric issues and for future research on victims of electrical trauma are discussed.

Convolving engineering and medical pedagogies for training of tomorrow's health care professionals.

Several fundamental benefits justify why biomedical engineering and medicine should form a more convergent alliance, especially for the training of tomorrow's physicians and biomedical engineers. Herein, we review the rationale underlying the benefits. Biological discovery has advanced beyond the era of molecular biology well into today's era of molecular systems biology, which focuses on understanding the rules that govern the behavior of complex living systems. This has important medical implications. To realize cost-effective personalized medicine, it is necessary to translate the advances in molecular systems biology to higher levels of biological organization (organ, system, and organismal levels) and then to develop new medical therapeutics based on simulation and medical informatics analysis. Higher education in biological and medical sciences must adapt to a new set of training objectives. This will involve a shifting away from reductionist problem solving toward more integrative, continuum, and predictive modeling approaches which traditionally have been more associated with engineering science. Future biomedical engineers and MDs must be able to predict clinical response to therapeutic intervention. Medical education will involve engineering pedagogies, wherein basic governing rules of complex system behavior and skill sets in manipulating these systems to achieve a practical desired outcome are taught. Similarly, graduate biomedical engineering programs will include more practical exposure to clinical problem solving.

Grand challenges in interfacing engineering with life sciences and medicine.

This paper summarizes the discussions held during the First IEEE Life Sciences Grand Challenges Conference, held on October 4-5, 2012, at the National Academy of Sciences, Washington, DC, and the grand challenges identified by the conference participants. Despite tremendous efforts to develop the knowledge and ability that are essential in addressing biomedical and health problems using engineering methodologies, the optimization of this approach toward engineering the life sciences and healthcare remains a grand challenge. The conference was aimed at high-level discussions by participants representing various sectors, including academia, government, and industry. Grand challenges were identified by the conference participants in five areas including engineering the brain and nervous system; engineering the cardiovascular system; engineering of cancer diagnostics, therapeutics, and prevention; translation of discoveries to clinical applications; and education and training. A number of these challenges are identified and summarized in this paper.

Mg ATP and antioxidants augment the radioprotective effect of surfactant copolymers.

Mediated by reactive oxygen species, the damaging effects of high-intensity ionizing irradiation on tissues are dose, frequency, oxygen concentration, and tissue property dependent. Intense ionizing irradiation exposure may cause rapid cellular necrosis by peroxidation of membrane lipids leading to membrane disruption. This leads to a loss of the transmembrane ionic gradients and a subsequent depletion of the cellular ATP store, followed by cellular generation of reactive oxygen species. When membrane disruption is extensive, acute cellular necrosis follows. Triblock copolymer surfactants, such as Poloxamer 188 (P188), are able to seal damaged rhabdomyocyte membranes, increasing post-irradiation viability. Separated rat rhabdomyocytes were exposed to 40 Gy (Co 1.5 Gy min) irradiation and treated at 20 min intervals with combination permutations of P188, N-acetylcysteine (NAC), and Mg-ATP. Cell viability at 18 and 48 h was determined using Calcein-AM and Ethidium Homodimer-1 staining. At 18 h after irradiation, the combined administration of P188, ATP, and NAC restored cell viability rates to near sham-exposed levels of 60%. At 48 h post-irradiation, cell viability dropped substantially to the 7-20% range, regardless of attempted intervention. Nevertheless, the combination of P188, ATP, and NAC more than doubled cell viability at the 48-h time point. Neither 8 kDa polyethylene glycol nor 10 kDa neutral dextran was as effective in enhancing cell viability. These results indicate that antioxidants and cellular energy substrates improve the efficacy of membrane-sealing copolymer surfactants in prolonging cellular viability following massive radiation exposure.