Dopamine, Norepinephrine and Serotonin Participate Differently in Methylphenidate Action in Concomitant Behavioral and Ventral Tegmental Area, Locus Coeruleus and Dorsal Raphe Neuronal Study in Young Rats.

Methylphenidate (MPD), known as Ritalin, is a psychostimulant used to treat children, adults, and the elderly. MPD exerts its effects through increasing concentrations of dopamine (DA), norepinephrine (NE), and serotonin (5-HT) in the synaptic cleft. Concomitant behavioral and neuronal recording from the ventral tegmental area (VTA), locus coeruleus (LC), and from the dorsal raphe (DR) nucleus, which are the sources of DA, NE, and 5-HT to the mesocorticolimbic circuit, were investigated following acute and repetitive (chronic) saline, 0.6, 2.5, or 10.0 mg/kg MPD. Animals received daily saline or MPD administration on experimental days 1 to 6 (ED1-6), followed by a 3-day washout period and MPD rechallenge on ED10. Each chronic MPD dose elicits behavioral sensitization in some animals while inducing behavioral tolerance in others. The uniqueness of this study is in the evaluation of neuronal activity based on the behavioral response to chronic MPD. Neuronal excitation was observed mainly in brain areas of animals exhibiting behavioral sensitization, while neuronal attenuation following chronic MPD was observed in animals expressing behavioral tolerance. Different ratios of excitatory/inhibitory neuronal responses were obtained from the VTA, LC, or DR following chronic MPD. Thus, each brain area responds differently to each MPD dose used, suggesting that DA, NE, and 5-HT in the VTA, LC, and DR exert different effects.

Methylphenidate induces a different response in the dorsal raphe as compared to ventral tegmental area and locus coeruleus: behavioral and concomitant neuronal recordings in adult rats.

Methylphenidate (MPD) is a psychostimulant used to treat attention deficit hyperactivity disorder. MPD exerts its neurocognitive effects through increasing concentrations of dopamine (DA), norepinephrine (NE), and serotonin (5-HT) in the neuronal synapse. This study recorded from adult freely behaving rats a total of 1170 neurons, 403 from the ventral tegmental area (VTA), 409 from locus coeruleus (LC), and 356 from dorsal raphe (DR) nucleus, which are the main sources of DA, NE, and 5-HT to the mesocorticolimbic circuitry, respectively. Electrophysiological and behavioral activities were recorded simultaneously following acute and repetitive (chronic) saline or 0.6, 2.5, or 10.0 mg/kg MPD. The uniqueness of this study is the evaluation of neuronal activity based on the behavioral response to chronic MPD. Animals received daily saline or MPD administration on experimental days 1-6 (ED1-6), followed by a 3-day wash-out period, and then MPD rechallenge on ED10. Each chronic MPD dose elicits behavioral sensitization in some animals, while in others, behavioral tolerance. Neuronal excitation following chronic MPD was observed in brains areas of animals exhibiting behavioral sensitization, while neuronal attenuation following chronic MPD was observed in those animals expressing behavioral tolerance. DR neuronal activity was most affected in response to acute and chronic MPD administration and responded differently compared to the neurons recorded from VTA and LC neurons at all doses. This suggests that although not directly related, DR and 5-HT are involved in the acute and chronic effects of MPD in adult rats, but exhibit a different role in response to MPD.

Photochemical separation of plutonium from uranium.

Plutonium-based technologies would benefit if chemical hazards for purifying plutonium were reduced. One critical processing step where improvements could be impactful is the adjustment of plutonium oxidation-states during separations. This transformation often requires addition of redox agents. Unfortunately, many of the redox agents used previously cannot be used today because their properties are deemed incompatible with modern day processing facilities and waste stream safety requirements. We demonstrated herein that photochemistry can be used as an alternative to those chemical agents. We observed that (1) Pu4+ → Pu3+ and UO22+ → U4+ photoreduction proceeded in HCl(aq) and HNO3(aq) and (2) photogenerated Pu3+(aq) and U4+(aq) could be separated using anion exchange chromatography (high yield, >90%; good separation factor, 322).

Fusion Oncogenes Are Associated With Increased Metastatic Capacity and Persistent Disease in Pediatric Thyroid Cancers.

PURPOSE: In 2014, data from a comprehensive multiplatform analysis of 496 adult papillary thyroid cancer samples reported by The Cancer Genome Atlas project suggested that reclassification of thyroid cancer into molecular subtypes, RAS-like and BRAF-like, better reflects clinical behavior than sole reliance on pathologic classification. The aim of this study was to categorize the common oncogenic variants in pediatric differentiated thyroid cancer (DTC) and investigate whether mutation subtype classification correlated with the risk of metastasis and response to initial therapy in pediatric DTC. METHODS: Somatic cancer gene panel analysis was completed on DTC from 131 pediatric patients. DTC were categorized into RAS-mutant (H-K-NRAS), BRAF-mutant (BRAF p.V600E), and RET/NTRK fusion (RET, NTRK1, and NTRK3 fusions) to determine differences between subtype classification in regard to pathologic data (American Joint Committee on Cancer TNM) as well as response to therapy 1 year after initial treatment had been completed. RESULTS: Mutation-based subtype categories were significant in most variables, including age at diagnosis, metastatic behavior, and the likelihood of remission at 1 year. Patients with RET/NTRK fusions were significantly more likely to have advanced lymph node and distant metastasis and less likely to achieve remission at 1 year than patients within RAS- or BRAF-mut subgroups. CONCLUSION: Our data support that genetic subtyping of pediatric DTC more accurately reflects clinical behavior than sole reliance on pathologic classification with patients with RET/NTRK fusions having worse outcomes than those with BRAF-mutant disease. Future trials should consider inclusion of molecular subtype into risk stratification.

Western lifestyle as a driver of dysbiosis in colorectal cancer.

Landmark discoveries in the gut microbiome field have paved the way for new research aimed at illuminating the influence of microbiota in colorectal cancer. A major challenge is to account for the effect of inherently variable environmental factors on the host and the gut microbiome, while concurrently determining their contribution to carcinogenesis. Here, we briefly discuss the role of the gut microbial community in colorectal cancer and elaborate on the recent insight that environmental factors related to a Western diet and lifestyle may drive the bloom of tumorigenic members of the gut microbiota. We also discuss how future research focused on untangling host-microbe interactions in the colon may influence medical insights that relate to the prevention and treatment of colorectal cancer.

Extrathyroidal Extension is an Important Predictor of Regional Lymph Node Metastasis in Pediatric Differentiated Thyroid Cancer.

Introduction: The American Joint Committee Cancer (AJCC) TNM system predicts survival in patients with differentiated thyroid cancer (DTC). In the eighth edition of the AJCC TNM, microscopic extrathyroidal extension (microETE) was removed and tumor size >4 cm was maintained in the definition of T3 disease to reduce unnecessarily aggressive therapy for adults at low risk of death from DTC. In pediatric patients where DTC survival rates are high, the AJCC TNM is used to identify patients at increased risk of persistent, postsurgical disease, to identify patients who benefit from radioactive iodine therapy. The aim of this study was to assess the correlation of microETE with cervical lymph node (LN) metastasis in pediatric patients and to determine if tumor size or microETE is more informative in predicting regional LN disease. Methods: Patients with DTC <19 years of age at the time of thyroidectomy with AJCC T3 tumors (seventh edition) and the presence of LNs on the surgical specimen were included in this retrospective chart review. Pathological findings were confirmed by pathologist review. Results: Forty-five patients with AJCC T3 designation were included, 34 with microETE and 11 without microETE. Of those with microETE, 32 (94.1%) demonstrated regional LN metastasis compared with 5/11 patients (45.5%) without microETE (p = 0.001). In addition, microETE was associated with lateral neck LN metastasis (p = 0.004), bilateral disease (p = 0.001), and tumor multifocality (p = 0.003). Patients with microETE had smaller tumors (median = 2.5 cm, interquartile range [IQR]: 1.6-4.5) compared with patients without microETE (median = 5 cm, IQR: 4.2-5.4; p = 0.02). No increased association was found between microETE and vascular invasion, distant metastasis, or persistent/recurrent disease. Conclusions: In pediatric patients with DTC, microETE is a strong predictor of LN metastasis when compared with tumor size. For patients who do not undergo prophylactic central neck LN dissection, the presence of microETE predicts an increased risk of postsurgical disease and should be included in future revisions of the American Thyroid Association pediatric risk stratification categories.

Unraveling the Dynamic Network in the Reactions of an Alkyl Aryl Ether Catalyzed by Ni/γ-Al2O3 in 2-Propanol.

The reductive cleavage of aryl ether linkages is a key step in the disassembly of lignin to its monolignol components, where selectivity is determined by the kinetics of multiple parallel and consecutive liquid-phase reactions. Triphasic hydrogenolysis of 13C-labeled benzyl phenyl ether (BPE, a model compound for the major ß-O-4 linkage in lignin), catalyzed by Ni/γ-Al2O3, was observed directly at elevated temperatures (150-175 °C) and pressures (79-89 bar) using operando magic-angle spinning NMR spectroscopy. Liquid-vapor partitioning in the NMR rotor was quantified using the 13C NMR resonances for the 2-propanol solvent, whose chemical shifts report on the internal reactor temperature. At 170 °C, BPE is converted to toluene and phenol with k1 = 0.17 s-1 gcat-1 and an apparent activation barrier of (80 ± 8) kJ mol-1. Subsequent phenol hydrogenation occurs much more slowly (k2 = 0.0052 s-1 gcat-1 at 170-175 °C), such that cyclohexanol formation is significant only at higher temperatures. Toluene is stable under these reaction conditions, but its methyl group undergoes facile H/D exchange (k3 = 0.046 s-1 gcat-1 at 175 °C). While the source of the reducing equivalents for both hydrogenolysis and hydrogenation is exclusively H2/D2(g) rather than the alcohol solvent at these temperatures, the initial isotopic composition of adsorbed H/D on the catalyst surface is principally determined by the solvent isotopic composition (2-PrOH/D). All reactions are preceded by a pronounced induction period associated with catalyst activation. In air, Ni nanoparticles are passivated by a surface oxide monolayer, whose removal under H2 proceeds with an apparent activation barrier of (72 ± 13) kJ mol-1. The operando NMR spectra provide molecularly specific, time-resolved information about the multiple simultaneous and sequential processes as they occur at the solid-liquid interface.

Functionalization of Brain Region-specific Spheroids with Isogenic Microglia-like Cells.

Current brain spheroids or organoids derived from human induced pluripotent stem cells (hiPSCs) still lack a microglia component, the resident immune cells in the brain. The objective of this study is to engineer brain region-specific organoids from hiPSCs incorporated with isogenic microglia-like cells in order to enhance immune function. In this study, microglia-like cells were derived from hiPSCs using a simplified protocol with stage-wise growth factor induction, which expressed several phenotypic markers, including CD11b, IBA-1, CX3CR1, and P2RY12, and phagocytosed micron-size super-paramagnetic iron oxides. The derived cells were able to upregulate pro-inflammatory gene (TNF-α) and secrete anti-inflammatory cytokines (i.e., VEGF, TGF-ß1, and PGE2) when stimulated with amyloid ß42 oligomers, lipopolysaccharides, or dexamethasone. The derived isogenic dorsal cortical (higher expression of TBR1 and PAX6) and ventral (higher expression of NKX2.1 and PROX1) spheroids/organoids displayed action potentials and synaptic activities. Co-culturing the microglia-like cells (MG) with the dorsal (D) or ventral (V) organoids showed differential migration ability, intracellular Ca2+ signaling, and the response to pro-inflammatory stimuli (V-MG group had higher TNF-α and TREM2 expression). Transcriptome analysis exhibited 37 microglia-related genes that were differentially expressed in MG and D-MG groups. In addition, the hybrid D-MG spheroids exhibited higher levels of immunoreceptor genes in activating members, but the MG group contained higher levels for most of genes in inhibitory members (except SIGLEC5 and CD200). This study should advance our understanding of the microglia function in brain-like tissue and establish a transformative approach to modulate cellular microenvironment toward the goal of treating various neurological disorders.

The Culture of Carbapenem Overconsumption: Where Does It Begin? Results of a Single-Center Survey.

Purpose: The United States has seen an increased consumption of carbapenem antibiotics in recent years. The increased utilization of these agents has potential negative consequences, including the increasing incidence of carbapenem-resistant Enterobacteriaceae. Reasons for the rise in carbapenem use among providers in acute care hospitals are not well elucidated in literature. The objectives of this study were to identify factors that influence empiric carbapenem use among providers in a single academic medical center, and to assess therapeutic knowledge pertaining to carbapenem use. Methods: A cross-sectional, single-center, 9-item electronic research survey was developed independently and validated by an infectious diseases pharmacist and infectious diseases physician. The survey was distributed to email accounts of providers at a single academic medical center. Demographic data, factors affecting carbapenem prescription, and baseline therapeutic knowledge were assessed. Results: Ninety-five of 416 providers responded to the survey (response rate of 22.8%). Respondents were well distributed across all levels of training with primary roles in internal medicine and surgery. The most important factors influencing empiric carbapenem use were suspected pathogens at the site of infection, drug allergies, history of multidrug resistant organisms, severity of illness, type of infection, and local resistance rates. A recommendation from a pharmacist was selected as the most likely factor for deterring carbapenem use. Misconceptions pertaining to penicillin drug allergy and beta-lactam cross reactivity, knowledge of local resistance rates according to the institutional antibiogram, and comparative efficacy data for carbapenems were apparent across all levels of training. Conclusions: Provider misconceptions regarding several factors appear to contribute to unnecessary use of carbapenems. An opportunity exists for hospital pharmacists to improve the prescribing patterns of carbapenems by correcting provider misconceptions through education.

A resorbable antibiotic eluting bone void filler for periprosthetic joint infection prevention.

Periprosthetic joint infection (PJI) following total knee arthroplasty is a globally increasing procedural complication. These infections are difficult to treat and typically require revision surgery. Antibiotic-loaded bone cement is frequently utilized to deliver antibiotics to the site of infection; however, bone cement is a nondegrading foreign body and known to leach its antibiotic load, after an initial burst release, at subtherapeutic concentrations for months. This work characterized a resorbable, antibiotic-eluting bone void filler designed to restore bone volume and prevent PJI. Three device formulations were fabricated, consisting of different combinations of synthetic inorganic bone graft material, degradable polymer matrices, salt porogens, and antibiotic tobramycin. These formulations were examined to determine the antibiotic's elution kinetics and bactericidal potential, the device's degradation in vitro, as well as osteoconductivity and device resorption in vivo using a pilot rabbit bone implant model. Kirby-Bauer antibiotic susceptibility tests assessed bactericidal activity. Liquid chromatography with tandem mass spectrometry measured antibiotic elution kinetics, and scanning electron microscopy was used to qualitatively assess degradation. Results indicated sustained antibiotic release from all three formulations above the Staphylococcus aureus minimum inhibitory concentration for a period of 5 to 8 weeks. Extensive degradation was observed with the Group 3 formulation after 90 days in phosphate-buffered saline, with a lesser degree of degradation observed in the other two formulations. Results from the pilot rabbit study showed the Group 3 device to be biocompatible, with minimal inflammatory response and no fibrous encapsulation in bone. The device was also highly osteoconductive-exhibiting an accelerated mineral apposition rate. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1632-1642, 2016.

Acute and chronic dose-response effect of methylphenidate on ventral tegmental area neurons correlated with animal behavior.

Methylphenidate (MPD) is used to treat ADHD and as a cognitive enhancement and recreationally. MPD's effects are not fully understood. One of the sites of psychostimulant action is the ventral tegmental area (VTA). The VTA neuronal activity was recorded from freely behaving rats using a wireless system. 51 animals were divided into groups: saline, 0.6, 2.5, and 10.0 mg/kg MPD. The same repetitive MPD dose can elicit either behavioral sensitization or tolerance; thus the evaluation of the VTA neuronal activity was based on the animals' behavioral response to chronic MPD exposure: animals exhibiting behavioral tolerance or sensitization. Acute MPD elicits dose-related increases in behavioral activity. About half of the animals exhibited behavioral sensitization or tolerance to each of the MPD doses. 361 units were recorded from the VTA and exhibited similar spike shape on experimental day 1 (ED1) and on ED10. 71, 84, and 79 % of VTA units responded to acute 0.6, 2.5, and 10.0 mg/kg MPD, respectively. The neuronal baseline activity at ED10 was significantly modified in 94, 95, and 100 % of VTA units following 0.6, 2.5 and 10.0 mg/kg MPD, respectively. Following chronic MPD exposure, 91, 98, and 100 % exhibit either electrophysiological tolerance or sensitization of 0.6, 2.6, or 10.0 mg/kg MPD, respectively. In conclusion, the chronic administration of the same dose of MPD caused some animals to exhibit behavioral sensitization and other animals to exhibit tolerance. The VTA units recorded from animals exhibiting behavioral sensitization responded significantly differently to MPD from animals that exhibited behavioral tolerance.

Dose response effect of methylphenidate on ventral tegmental area neurons and animal behavior.

Methylphenidate (MPD) is the drug of choice prescribed to treat ADHD patients. More recently, MPD is also used as a cognitive enhancement and recreationally by young adults and its therapeutic effects are not fully understood. One of the neuroanatomical sites is reported to be the ventral tegmental area (VTA). The ventral tegmental area neuronal activity was recorded from freely behaving non-anesthetized rats implanted bilaterally with semi-permanent electrodes which were recorded from a wireless telemetric system. Thirty-three animals, divided randomly into four groups, were used: saline (n=10), 0.6 mg/kg (n=6), 2.5 mg/kg (n=7) and 10.0 mg/kg MPD (n=10). MPD caused an increase in locomotor activity with a dose response characteristic; 0.6 mg/kg MPD elicited some increase in locomotion, but not significantly, while 2.5 and 10.0 mg/kg MPD elicited significant increases in behavior of 191% and 870% respectively. A total of 209 ventral tegmental area units were recorded; 100% (36/36) units showed no response to saline; 89% (154/173) of the neurons responded to MPD, with the majority 66% (101/154) showing an increase in activity. In response to 0.6 mg/kg (n=52), the majority of units 54% (28/52) showed a decrease in activity. For both 2.5 (n=60) and 10.0 mg/kg (n=61), the majority of ventral tegmental area units responded with an increase in activity with 63% (38/60) and 70% (43/61) respectively. This study demonstrated that the majority of ventral tegmental area neurons respond to acute MPD in a dose response characteristic and are not related to the animal's locomotor activity.