Rapid tissue prototyping with micro-organospheres.

In vitro tissue models hold great promise for modeling diseases and drug responses. Here, we used emulsion microfluidics to form micro-organospheres (MOSs), which are droplet-encapsulated miniature three-dimensional (3D) tissue models that can be established rapidly from patient tissues or cells. MOSs retain key biological features and responses to chemo-, targeted, and radiation therapies compared with organoids. The small size and large surface-to-volume ratio of MOSs enable various applications including quantitative assessment of nutrient dependence, pathogen-host interaction for anti-viral drug screening, and a rapid potency assay for chimeric antigen receptor (CAR)-T therapy. An automated MOS imaging pipeline combined with machine learning overcomes plating variation, distinguishes tumorspheres from stroma, differentiates cytostatic versus cytotoxic drug effects, and captures resistant clones and heterogeneity in drug response. This pipeline is capable of robust assessments of drug response at individual-tumorsphere resolution and provides a rapid and high-throughput therapeutic profiling platform for precision medicine.

Prophylaxis of mitochondrial dysfunction caused by cellular decompression from hyperbaric exposure.

Mitochondrial dysfunction occurring in response to cellular perturbations can include altered mitochondrial motility and bioenergetic function having intracellular heterogeneity. Exogenous mitochondrial directed therapy may correct these dysfunctions. Using in vitro approaches, we find that cell perturbations induced by rapid decompression from hyperbaric conditions with specific gas exposures has differential effects on mitochondrial motility, inner membrane potential, cellular respiration, reactive oxygen species production, impaired maintenance of cell shape and altered intracellular distribution of bioenergetic capacity in perinuclear and cell peripheral domains. Addition of a first-generation cell-permeable succinate prodrug to support mitochondrial function has positive overall effects in blunting the resultant bioenergy responses. Our results with this model of perturbed cell function induced by rapid decompression indicate that alterations in bioenergetic state are partitioned within the cell, as directly assessed by a combination of mitochondrial respiration and dynamics measurements. Reductions in the observed level of dysfunction produced can be achieved with application of the cell-permeable succinate prodrug.

Efficacy of methylene blue in an experimental model of calcium channel blocker-induced shock.

STUDY OBJECTIVE: Calcium channel blocker poisonings account for a substantial number of reported deaths from cardiovascular drugs. Although supportive care is the mainstay of treatment, experimental therapies such as high-dose insulin-euglycemia and lipid emulsion have been studied in animal models and used in humans. In the most severe cases, even aggressive care is inadequate and deaths occur. In both experimental models and clinical cases of vasodilatory shock, methylene blue improves hemodynamic measures. It acts as a nitric oxide scavenger and inhibits guanylate cyclase that is responsible for the production of cyclic guanosine monophosphate (cGMP). Excessive cGMP production is associated with refractory vasodilatory shock in sepsis and anaphylaxis. The aim of this study is to determine the efficacy of methylene blue in an animal model of amlodipine-induced shock. METHODS: Sprague-Dawley rats were anesthetized, ventilated, and instrumented for continuous blood pressure and pulse rate monitoring. The dose of amlodipine that produced death within 60 minutes was 17 mg/kg per hour (LD50). Rats were divided into 2 groups: amlodipine followed by methylene blue or amlodipine followed by normal saline solution, with 15 rats in each group. Rats received methylene blue at 2 mg/kg during 5 minutes or an equivalent amount of normal saline solution in 3 intervals from the start of the protocol: minutes 5, 30, and 60. The animals were observed for a total of 2 hours after the start of the protocol. Mortality risk and survival time were analyzed with Fisher's exact test and Kaplan-Meier survival analysis with the log rank test. RESULTS: Overall, 1 of 15 rats (7%) in the saline solution-treated group survived to 120 minutes compared with 5 of 15 (33%) in the methylene blue-treated group (difference -26%; 95% confidence interval [CI] -54% to 0.3%). The median survival time for the normal saline solution group was 42 minutes (95% CI 28.1 to 55.9 minutes); for the methylene blue group, 109 minutes (95% CI 93.9 to 124.1 minutes). Pulse rate and mean arterial pressure (MAP) differences between groups were analyzed until 60 minutes. Pulse rate was significantly higher in the methylene blue-treated group beginning 25 minutes after the start of the amlodipine infusion (95% CI 30 to 113 minutes) that was analyzed until 60 minutes. MAP was significantly higher in the methylene blue-treated group starting 25 minutes after the amlodipine infusion (95% CI 2 to 30 minutes) that was analyzed until 60 minutes. CONCLUSION: Methylene blue did not result in a significant difference in mortality risk. There was an increased pulse rate, MAP, and median survival time in the methylene blue group.

Toxin-induced cardiovascular failure.

Adverse cardiovascular events comprise a large portion of the morbidity and mortality in drug overdose emergencies. Adverse cardiovascular events encountered by emergency physicians treating poisoned patients include myocardial injury, hemodynamic compromise with shock, tachydysrhythmias, and cardiac arrest. Early signs of toxin-induced cardiovascular failure include bradycardia, tachycardia, and specific ECG findings. Treatment of toxicologic tachycardia relies on rapid supportive care along with proper use of benzodiazepines for sedation. Treatment of toxicologic bradycardia consists of the use of isotonic fluids, atropine, calcium salts, and glucagon. High-dose insulin euglycemia should be used early in the course of suspected severe poisoning and intravenous lipid emulsion given to patients who suffer cardiac arrest.

Heavy metal chelation in neurotoxic exposures.

Metals such as iron and copper are critical to living organisms, whereas other metals such as lead and arsenic have no known biologic role. Any metals in large amounts may cause toxicity. Many metals cause pervasive systemic effects involving the nervous system, which can be subtle in some cases. Although challenging, the diagnosis and treatment of metal poisoning can be made based on history, physical examination, and the proper use of metal testing. This article focuses on the use, and misuse, of chelation in the diagnosis and management of metal intoxication.

Neuromonics™ Tinnitus Treatment: preliminary experience in a private practice setting.

EDUCATIONAL OBJECTIVE: At the conclusion of this presentation, the participants should be able to identify the principles behind the Neuromonics™ Tinnitus Treatment (NTT) and understand its strengths and potential shortfalls. OBJECTIVES: To describe the preliminary experience and efficacy of the NTT in an independent, non-industry sponsored private otology practice clinical study. STUDY DESIGN: Case series with retrospective chart review and post-intervention quality of life questionnaire. METHODS: Tinnitus Reaction Questionnaire (TRQ) scores, and awareness and disturbance scores, were obtained pre- and post-treatment. A posttreatment questionnaire based on the Glasgow Benefit Inventory (GBI) was conducted over the telephone. RESULTS: Eleven patients had completed the six-month program at the time of the study. Nine of the eleven patients completing therapy were considered "highly suitable". TRQ scores were universally improved (ranging from a 3 to 78% decrease in the TRQ score). However, only two of the seven (29%) had achieved a decrease in the TRQ score by 40% or more. Seven of ten patients (70%), and four of ten (40%) patients reported a reduction in the percentage of the time they were aware of and disturbed by their tinnitus, respectively. Eight of ten patients (80%) exhibited positive scores on the GBI (mean 17.39, median 7.81, range -3.1 to 67.6). When asked whether they thought the device was worth the cost, responses were divided equally between positive and negative responses. CONCLUSION: Neuromonics ™ Tinnitus Treatment appears to be a practical and promising treatment for tinnitus.