Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Mol Psychiatry ; 28(2): 722-732, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36352123

RESUMEN

Increasing extracellular levels of serotonin (5-HT) in the brain ameliorates symptoms of depression and anxiety-related disorders, e.g., social phobias and post-traumatic stress disorder. Recent evidence from preclinical and clinical studies established the therapeutic potential of drugs inducing the release of 5-HT via the 5-HT-transporter. Nevertheless, current 5-HT releasing compounds under clinical investigation carry the risk for abuse and deleterious side effects. Here, we demonstrate that S-enantiomers of certain ring-substituted cathinones show preference for the release of 5-HT ex vivo and in vivo, and exert 5-HT-associated effects in preclinical behavioral models. Importantly, the lead cathinone compounds (1) do not induce substantial dopamine release and (2) display reduced off-target activity at vesicular monoamine transporters and 5-HT2B-receptors, indicative of low abuse-liability and low potential for adverse events. Taken together, our findings identify these agents as lead compounds that may prove useful for the treatment of disorders where elevation of 5-HT has proven beneficial.


Asunto(s)
Dopamina , Serotonina , Encéfalo , Proteínas Portadoras
2.
Int J Legal Med ; 138(3): 823-831, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38214738

RESUMEN

Synthetic cannabinoids become increasingly popular as a supposedly safe and legal alternative to cannabis. In order to circumvent the German New Psychoactive Substances Law, producers of so-called herbal mixtures rapidly design new substances with structural alterations that are not covered by the law. Acting as full agonists not only at the cannabinoid receptors 1 and 2, synthetic cannabinoids might have not only desired mental but also serious physical adverse effects. However, knowledge of adverse effects of specific substances is sparse and incomplete. This also accounts for 5F-Cumyl-PEGACLONE, a synthetic cannabinoid, which has been detected regularly in Germany in recent years. By using an animal model, the isolated perfused Langendorff heart, the study at hand aimed on finding out more about possible cardiovascular adverse effects of 5F-Cumyl-PEGACLONE. Hearts of male Wistar rats, which were excised postmortem, were exposed to two different concentrations of 5F-Cumyl-PEGACLONE: 13 hearts were exposed to 50 ng/ml and 12 hearts were exposed to 100 ng/ml. Thirteen control hearts were merely exposed to an additional amount of buffer solution. Functional parameters heart rate, minimal and maximum left ventricular pressure and coronary flow were documented at pre-defined time points during and after the administration of 5F-Cumyl-PEGACLONE/additional buffer solution. Electrocardiograms (ECGs) were documented throughout the experiments and evaluated afterwards. Kruskal-Wallis analysis was performed for each functional parameter as well as for the duration of the QRS complexes and the duration of RR intervals as derived from the ECGs. Furthermore, a multivariate analysis, comprising all functional and ECG parameters, was performed. Kruskal-Wallis analysis revealed only single significant p-values for QRS duration and minimum left ventricular pressure that did not pass a Bonferroni test. The results of the multivariate approach were also comparably homogeneous, but still the model correctly recognized hearts exposed to 100 ng/ml of 5F-Cumyl-PEGACLONE more often than hearts exposed to the low concentration of 5F-Cumyl-PEGACLONE or additional buffer solution. Evaluation of the ECGs presented single cases of ST depression and QT prolongation. Though certainly not unambiguous, these findings support the assumption that 5F-Cumyl-PEGACLONE can cause severe, if not lethal, cardiac adverse effects like arrhythmias or myocardial infarctions especially if it is consumed in combination with other drugs like alcohol or if the consumer suffers from pre-existing heart diseases.


Asunto(s)
Cannabinoides , Cannabis , Alucinógenos , Masculino , Ratas , Animales , Ratas Wistar , Cannabinoides/análisis
3.
Mol Psychiatry ; 27(12): 4869-4880, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36117213

RESUMEN

Virtually all neuropsychiatric disorders display sex differences in prevalence, age of onset, and/or clinical symptomology. Although altered dopamine (DA) signaling is a feature of many of these disorders, sex-dependent mechanisms uniquely responsive to DA that drive sex-dependent behaviors remain unelucidated. Previously, we established that anomalous DA efflux (ADE) is a prominent feature of the DA transporter (DAT) variant Val559, a coding substitution identified in two male-biased disorders: attention-deficit/hyperactivity disorder and autism spectrum disorder. In vivo, Val559 ADE induces activation of nigrostriatal D2-type DA autoreceptors (D2ARs) that magnifies inappropriate, nonvesicular DA release by elevating phosphorylation and surface trafficking of ADE-prone DAT proteins. Here we demonstrate that DAT Val559 mice exhibit sex-dependent alterations in psychostimulant responses, social behavior, and cognitive performance. In a search for underlying mechanisms, we discovered that the ability of ADE to elicit D2AR regulation of DAT is both sex and circuit-dependent, with dorsal striatum D2AR/DAT coupling evident only in males, whereas D2AR/DAT coupling in the ventral striatum is exclusive to females. Moreover, systemic administration of the D2R antagonist sulpiride, which precludes ADE-driven DAT trafficking, can normalize DAT Val559 behavioral changes unique to each sex and without effects on the opposite sex or wildtype mice. Our studies support the sex- and circuit dependent capacity of D2ARs to regulate DAT as a critical determinant of the sex-biased effects of perturbed DA signaling in neurobehavioral disorders. Moreover, our work provides a cogent example of how a shared biological insult drives alternative physiological and behavioral trajectories as opposed to resilience.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad , Trastorno del Espectro Autista , Dopamina , Animales , Femenino , Masculino , Ratones , Trastorno por Déficit de Atención con Hiperactividad/metabolismo , Trastorno del Espectro Autista/metabolismo , Estimulantes del Sistema Nervioso Central/farmacología , Estimulantes del Sistema Nervioso Central/uso terapéutico , Dopamina/metabolismo , Dopamina/farmacología , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/metabolismo , Transducción de Señal
4.
Int J Legal Med ; 136(1): 133-147, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34181078

RESUMEN

The diagnosis of death due to violent asphyxiation may be challenging if external injuries are missing, and a typical acute emphysema (AE) "disappears" in pre-existing chronic emphysema (CE). Eighty-four autopsy cases were systematically investigated to identify a (histo-) morphological or immunohistochemical marker combination that enables the diagnosis of violent asphyxiation in cases with a pre-existing CE ("AE in CE"). The cases comprised four diagnostic groups, namely "AE", "CE", "acute and chronic emphysema (AE + CE)", and "no emphysema (NE)". Samples from all pulmonary lobes were investigated by conventional histological methods as well as with the immunohistochemical markers Aquaporin 5 (AQP-5) and Surfactant protein A1 (SP-A). Particular attention was paid to alveolar septum ends ("dead-ends") suspected as rupture spots, which were additionally analyzed by transmission electron microscopy. The findings in the four diagnostic groups were compared using multivariate analysis and 1-way ANOVA analysis. All morphological findings were found in all four groups. Based on histological and macroscopic findings, a multivariate analysis was able to predict the correct diagnosis "AE + CE" with a probability of 50%, and the diagnoses "AE" and "CE" with a probability of 86% each. Three types of "dead-ends" could be differentiated. One type ("fringed ends") was observed significantly more frequently in AE. The immunohistochemical markers AQP-5 and SP-A did not show significant differences among the examined groups. Though a reliable identification of AE in CE could not be achieved using the examined parameters, our findings suggest that considering many different findings from the macroscopical, histomorphological, and molecular level by multivariate analysis is an approach that should be followed.


Asunto(s)
Enfisema , Enfisema Pulmonar , Asfixia/patología , Autopsia , Enfisema/metabolismo , Enfisema/patología , Humanos , Pulmón/patología , Enfisema Pulmonar/diagnóstico , Enfisema Pulmonar/patología
5.
Int J Legal Med ; 135(1): 167-173, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32632799

RESUMEN

Age estimation based on the analysis of DNA methylation patterns has become a focus of forensic research within the past few years. However, there is little data available regarding postmortem DNA methylation analysis yet, and literature mainly encompasses analysis of blood from corpses without any signs of decomposition. It is not entirely clear yet which other types of specimen are suitable for postmortem epigenetic age estimation, and if advanced decomposition may affect methylation patterns of CpG sites. In living persons, buccal swabs are an easily accessible source of DNA for epigenetic age estimation. In this work, the applicability of this approach (buccal swabs as source of DNA) under different postmortem conditions was tested. Methylation levels of PDE4C were investigated in buccal swab samples collected from 73 corpses (0-90 years old; mean: 51.2) in different stages of decomposition. Moreover, buccal swab samples from 142 living individuals (0-89 years old; mean 41.2) were analysed. As expected, methylation levels exhibited a high correlation with age in living individuals (training set: r2 = 0.87, validation set: r2 = 0.85). This was also the case in postmortem samples (r2 = 0.90), independent of the state of decomposition. Only in advanced putrified cases with extremely low DNA amounts, epigenetic age estimation was not possible. In conclusion, buccal swabs are a suitable and easy to collect source for DNA methylation analysis as long as sufficient amounts of DNA are present.


Asunto(s)
Envejecimiento/genética , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/genética , Metilación de ADN , Mucosa Bucal/química , Cambios Post Mortem , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Islas de CpG/genética , Epigénesis Genética , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Reacción en Cadena en Tiempo Real de la Polimerasa , Adulto Joven
6.
J Environ Manage ; 290: 112557, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33865154

RESUMEN

Due to the amendment of the sewage sludge ordinance, both a thermal post-treatment and a phosphorous recovery from sewage sludge will become mandatory for large-scale wastewater treatment plants in Germany. This study analyzed four prospective treatment paths for sewage sludge by means of life cycle assessment. In the realm of a gate-to-cradle approach, environmental impacts were quantified for all compartments of the ReCiPe Midpoint (H) 2016 method. The spreading of digested sludge on agricultural soils was considered as the base case (system: AD + spreading). It was compared to the centralized incineration of sludge (system: AD + I), a decentralized hydrothermal carbonization followed by centralized incineration (system: AD + HTC + I) and a decentralized pyrolysis of sludge followed by centralized incineration (system: AD + P + I). For all cases, phosphorous recovery from the ash was included. A comparative evaluation showed that AD + spreading resulted in least environmental impacts in most categories but was subject to a high local immission potential due to sewage sludge spreading. It was found to be only justifiable, if toxicity and eutrophication were not compromised. Alternatively, a thermal post-treatment step is required. Hereby, AD + I and AD + HTC + I showed the overall least environmental impacts, while AD + P + I was characterized by similar or higher environmental impacts throughout all impact categories. Alongside the comparative analysis, a hotspot analysis was carried out and mitigation potentials were identified. For all thermochemical post-treatment paths, it was derived that (i) the share of fossil external energy must be kept to a minimum, (ii) primary or secondary measures to control N2O emissions during the incineration and pyrolysis should be implemented and (iii) the technological approach to recover phosphorous must be carefully selected.


Asunto(s)
Incineración , Aguas del Alcantarillado , Animales , Alemania , Estadios del Ciclo de Vida , Estudios Prospectivos
7.
J Biol Chem ; 292(10): 4235-4243, 2017 03 10.
Artículo en Inglés | MEDLINE | ID: mdl-28096460

RESUMEN

The human dopamine transporter (DAT) has a tetrahedral Zn2+-binding site. Zn2+-binding sites are also recognized by other first-row transition metals. Excessive accumulation of manganese or of copper can lead to parkinsonism because of dopamine deficiency. Accordingly, we examined the effect of Mn2+, Co2+, Ni2+, and Cu2+ on transport-associated currents through DAT and DAT-H193K, a mutant with a disrupted Zn2+-binding site. All transition metals except Mn2+ modulated the transport cycle of wild-type DAT with affinities in the low micromolar range. In this concentration range, they were devoid of any action on DAT-H193K. The active transition metals reduced the affinity of DAT for dopamine. The affinity shift was most pronounced for Cu2+, followed by Ni2+ and Zn2+ (= Co2+). The extent of the affinity shift and the reciprocal effect of substrate on metal affinity accounted for the different modes of action: Ni2+ and Cu2+ uniformly stimulated and inhibited, respectively, the substrate-induced steady-state currents through DAT. In contrast, Zn2+ elicited biphasic effects on transport, i.e. stimulation at 1 µm and inhibition at 10 µm A kinetic model that posited preferential binding of transition metal ions to the outward-facing apo state of DAT and a reciprocal interaction of dopamine and transition metals recapitulated all experimental findings. Allosteric activation of DAT via the Zn2+-binding site may be of interest to restore transport in loss-of-function mutants.


Asunto(s)
Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/metabolismo , Metales/metabolismo , Elementos de Transición/metabolismo , Zinc/metabolismo , Regulación Alostérica , Sitios de Unión , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/química , Humanos , Unión Proteica , Especificidad por Sustrato
8.
J Inherit Metab Dis ; 37(4): 505-23, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24687294

RESUMEN

To attain functionality, proteins must fold into their three-dimensional native state. The intracellular balance between protein synthesis, folding, and degradation is constantly challenged by genetic or environmental stress factors. In the last ten years, protein misfolding induced by missense mutations was demonstrated to be the seminal molecular mechanism in a constantly growing number of inborn errors of metabolism. In these cases, loss of protein function results from early degradation of missense-induced misfolded proteins. Increasing knowledge on the proteostasis network and the protein quality control system with distinct mechanisms in different compartments of the cell paved the way for the development of new treatment strategies for conformational diseases using small molecules. These comprise proteostasis regulators that enhance the capacity of the proteostasis network and pharmacological chaperones that specifically bind and rescue misfolded proteins by conformational stabilization. They can be used either alone or in combination, the latter to exploit synergistic effects. Many of these small molecule compounds currently undergo preclinical and clinical pharmaceutical development and two have been approved: saproterin dihydrochloride for the treatment of phenylketonuria and tafamidis for the treatment of transthyretin-related hereditary amyloidosis. Different technologies are exploited for the discovery of new small molecule compounds that belong to the still young class of pharmaceutical products discussed here. These compounds may in the near future improve existing treatment strategies or even offer a first-time treatment to patients suffering from nowadays-untreatable inborn errors of metabolism.


Asunto(s)
Errores Innatos del Metabolismo/terapia , Chaperonas Moleculares/uso terapéutico , Pliegue de Proteína , Deficiencias en la Proteostasis/terapia , Animales , Sistemas de Liberación de Medicamentos , Degradación Asociada con el Retículo Endoplásmico/fisiología , Humanos , Cinética , Errores Innatos del Metabolismo/complicaciones , Errores Innatos del Metabolismo/metabolismo , Chaperonas Moleculares/farmacología , Pliegue de Proteína/efectos de los fármacos , Proteínas/química , Proteínas/metabolismo , Deficiencias en la Proteostasis/complicaciones , Deficiencias en la Proteostasis/metabolismo
9.
Int J Legal Med ; 128(5): 787-94, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24819153

RESUMEN

The verification of acute and lethal myocardial infarctions remains a crucial problem in the daily routine work of legal medicine. In order to enhance the possibilities in micromorphologic diagnostics, we investigated if dityrosine as a protein product of oxidative stress can be detected in myocardial tissue after an infarction and, if so, if it occurs early enough to be used in the diagnosis of infarctions with a short survival time. We examined tissue samples from 61 autopsy cases (37 male, 24 female) with verified or suspected infarctions as well as 11 control cases (7 male, 4 female). Immunohistochemical staining was performed for dityrosine and the established markers fibronectin and C5b-9. Positive staining for dityrosine was obtained in nearly all cases with infarctions aged 4 h to 2 weeks. Single positive results were obtained in cases with older (up to 2 months) or assumedly very fresh (up to 4 h) infarctions. Furthermore, single positive results with a different staining pattern were obtained in the control group. We concluded that dityrosine as a marker of oxidative stress can be detected after infarctions and might occur early enough to be helpful in the diagnosis of infarctions with a short survival time. Though dityrosine does not seem to be specific for infarctions, the different staining patterns enable a differentiation.


Asunto(s)
Infarto del Miocardio/metabolismo , Miocardio/metabolismo , Tirosina/análogos & derivados , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores/metabolismo , Estudios de Casos y Controles , Niño , Preescolar , Complejo de Ataque a Membrana del Sistema Complemento/metabolismo , Femenino , Fibronectinas/metabolismo , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Infarto del Miocardio/patología , Estrés Oxidativo , Factores de Tiempo , Tirosina/metabolismo , Adulto Joven
10.
Basic Clin Pharmacol Toxicol ; 134(2): 206-218, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37987120

RESUMEN

Aberrant dopamine (DA) signalling has been implicated in various neuropsychiatric disorders, including attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), schizophrenia, bipolar disorder (BPD) and addiction. The availability of extracellular DA is sculpted by the exocytotic release of vesicular DA and subsequent transporter-mediated clearance, rendering the presynaptic DA transporter (DAT) a crucial regulator of DA neurotransmission. D2-type DA autoreceptors (D2ARs) regulate multiple aspects of DA homeostasis, including (i) DA synthesis, (ii) vesicular release, (iii) DA neuron firing and (iv) the surface expression of DAT and DAT-mediated DA clearance. The DAT Val559 variant, identified in boys with ADHD or ASD, as well as in a girl with BPD, supports anomalous DA efflux (ADE), which we have shown drives tonic activation of D2ARs. Through ex vivo and in vivo studies of the DAT Val559 variant using transgenic knock-in mice, we have uncovered a circuit and sex-specific capacity of D2ARs to regulate DAT, which consequently disrupts DA signalling and behaviour differently in males and females. Our studies reveal the ability of the construct-valid DAT Val559 model to elucidate endogenous mechanisms that support DA signalling, findings that may be of translational and/or therapeutic importance.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad , Trastorno del Espectro Autista , Humanos , Masculino , Ratones , Animales , Femenino , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/genética , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/metabolismo , Trastorno por Déficit de Atención con Hiperactividad/genética , Ratones Transgénicos , Transducción de Señal
11.
Nat Commun ; 15(1): 417, 2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38195746

RESUMEN

The presynaptic serotonin transporter (SERT) clears extracellular serotonin following vesicular release to ensure temporal and spatial regulation of serotonergic signalling and neurotransmitter homeostasis. Prescription drugs used to treat neurobehavioral disorders, including depression, anxiety, and obsessive-compulsive disorder, trap SERT by blocking the transport cycle. In contrast, illicit drugs of abuse like amphetamines reverse SERT directionality, causing serotonin efflux. Both processes result in increased extracellular serotonin levels. By combining molecular dynamics simulations with biochemical experiments and using a homologous series of serotonin analogues, we uncovered the coupling mechanism between the substrate and the transporter, which triggers the uptake of serotonin. Free energy analysis showed that only scaffold-bound substrates could initiate SERT occlusion through attractive long-range electrostatic interactions acting on the bundle domain. The associated spatial requirements define substrate and inhibitor properties, enabling additional possibilities for rational drug design approaches.


Asunto(s)
Proteínas de Transporte de Serotonina en la Membrana Plasmática , Serotonina , Humanos , Ligandos , Ansiedad , Trastornos de Ansiedad
13.
Neuropharmacology ; 240: 109704, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37703919

RESUMEN

Mephedrone (4-methylmethcathinone) is a cathinone derivative that is recreationally consumed for its energizing and empathogenic effects. The stimulating properties are believed to arise from the ability of mephedrone to interact with the high-affinity transporters for dopamine (DA) (DAT) and norepinephrine (NET), whereas the entactogenic effect presumably relies on its activity at the serotonin (5-HT) transporter (SERT). Early studies found that mephedrone acts as a releaser at NET, DAT and SERT, and thus promotes efflux of the respective monoamines. Evidence linked drug-induced reverse transport of 5-HT via SERT to prosocial effects, whereas activity at DAT is strongly correlated with abuse liability. Consequently, we sought to evaluate the pharmacology of mephedrone at human (h) DAT and SERT, heterologously expressed in human embryonic kidney 293 cells, in further detail. In line with previous studies, we report that mephedrone evokes carrier-mediated release via hDAT and hSERT. We found this effect to be sensitive to the protein kinase C inhibitor GF109203X. Electrophysiological recordings revealed that mephedrone is actively transported by hDAT and hSERT. However, mephedrone acts as a full substrate of hSERT but as a partial substrate of hDAT. Furthermore, when compared to fully efficacious releasing agents at hDAT and hSERT (i.e. S(+)-amphetamine and para-chloroamphetamine, respectively) mephedrone displays greater efficacy as a releaser at hSERT than at hDAT. In summary, this study provides additional insights into the molecular mechanism of action of mephedrone at hDAT and hSERT.

14.
bioRxiv ; 2023 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-37205452

RESUMEN

Aberrant dopamine (DA) signaling is implicated in schizophrenia, bipolar disorder (BPD), autism spectrum disorder (ASD), substance use disorder, and attention-deficit/hyperactivity disorder (ADHD). Treatment of these disorders remains inadequate. We established that the human DA transporter (DAT) coding variant (DAT Val559), identified in individuals with ADHD, ASD, or BPD, exhibits anomalous DA efflux (ADE) that is blocked by therapeutic amphetamines and methylphenidate. As the latter agents have high abuse liability, we exploited DAT Val559 knock-in mice to identify non-addictive agents that can normalize DAT Val559 functional and behavioral effects ex vivo and in vivo. Kappa opioid receptors (KORs) are expressed by DA neurons and modulate DA release and clearance, suggesting that targeting KORs might offset the effects of DAT Val559. We establish that enhanced DAT Thr53 phosphorylation and increased DAT surface trafficking associated with DAT Val559 expression are mimicked by KOR agonism of wildtype preparations and rescued by KOR antagonism of DAT Val559 ex vivo preparations. Importantly, KOR antagonism also corrected in vivo DA release and sex-dependent behavioral abnormalities. Given their low abuse liability, our studies with a construct valid model of human DA associated disorders reinforce considerations of KOR antagonism as a pharmacological strategy to treat DA associated brain disorders.

15.
Cells ; 11(24)2022 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-36552823

RESUMEN

Identified across multiple psychiatric disorders, the dopamine (DA) transporter (DAT) Ala559Val substitution triggers non-vesicular, anomalous DA efflux (ADE), perturbing DA neurotransmission and behavior. We have shown that DAT Val559 mice display a waiting impulsivity and changes in cognitive performance associated with enhanced reward motivation. Here, utilizing a within-subject, lever-pressing paradigm designed to bias the formation of goal-directed or habitual behavior, we demonstrate that DAT Val559 mice modulate their nose poke behavior appropriately to match context, but demonstrate a perseverative checking behavior. Although DAT Val559 mice display no issues with the cognitive flexibility required to acquire and re-learn a visual pairwise discrimination task, devaluation of reward evoked habitual reward seeking in DAT Val559 mutants in operant tasks regardless of reinforcement schedule. The direct DA agonist apomorphine also elicits locomotor stereotypies in DAT Val559, but not WT mice. Our observation that dendritic spine density is increased in the dorsal medial striatum (DMS) of DAT Val559 mice speaks to an imbalance in striatal circuitry that might underlie the propensity of DAT Val559 mutants to exhibit compulsive behaviors when reward is devalued. Thus, DAT Val559 mice represent a model for dissection of how altered DA signaling perturbs circuits that normally balance habitual and goal-directed behaviors.


Asunto(s)
Trastornos Mentales , Ratones , Masculino , Animales , Conducta Compulsiva , Recompensa , Cuerpo Estriado , Motivación
16.
Waste Manag ; 130: 93-106, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-34062462

RESUMEN

By means of source-segregation, organic waste streams are deterred from mass-burning and more sustainable treatment paths may be enabled. This study analyzed the environmental and economic performance of custom treatment paths for organic waste streams in Germany towards energy generation. The reference quantity was the production and export of 1 kWh of exergy, while treating a certain amount of waste. The methodologies of environmental life cycle assessment (eLCA) and levelized costs of exergy (LCOE) were applied. The considered treatment systems were (i) anaerobic digestion, (ii) hydrothermal carbonization (HTC) and (iii) incineration. The technologies were considered individually or in a cascade. The analyzed waste streams were the organic fraction of municipal solid waste (OFMSW), food waste and waste wood. For food waste and OFMSW, anaerobic digestion followed by the spreading of the digestate was characterized by overall beneficial environmental and economic properties. As the preferable treatment system was the same for both substrates, a separate collection of food waste was not considered worthwhile. For waste wood, the most environmentally friendly and economic option was direct incineration - either in a waste incinerator or in a lignite power plant. The implementation of an HTC process appeared viable for the treatment of OFMSW and food waste, both from an environmental and economic point of view. However, the energy intensive system must be outlined towards an environmentally friendly heat source. In this context, a cascading of anaerobic digestion with the HTC-process proofed to be an acceptable alternative.


Asunto(s)
Incineración , Eliminación de Residuos , Anaerobiosis , Animales , Alimentos , Alemania , Estadios del Ciclo de Vida , Residuos Sólidos/análisis
17.
Front Cell Neurosci ; 15: 681539, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34512264

RESUMEN

The dopamine 2 receptors (D2R) are G-protein coupled receptors expressed both in pre- and post-synaptic terminals that play an important role in mediating the physiological and behavioral effects of amphetamine (Amph). Previous studies have indicated that the effects of Amph at the D2R mainly rely on the ability of Amph to robustly increase extracellular dopamine through the dopamine transporter (DAT). This implies that the effects of Amph on D2R require the neurotransmitter dopamine. However, because of its lipophilic nature, Amph can cross the cellular membrane and thus potentially affect D2R expression independently of dopamine and DAT, e.g., in post-synaptic terminals. Here we used an in vitro system to study whether Amph affects total expression, cellular distribution, and function of the human D2R (hD2R), endogenously expressed in HEK293 cells. By performing Western blot experiments, we found that prolonged treatments with 1 or 50 µM Amph cause a significant decrease of the endogenous hD2R in cells transfected with human DAT (hDAT). On the other hand, in cells lacking expression of DAT, quantification of the hD2R-mediated changes in cAMP, biotinylation assays, Western blots and imaging experiments demonstrated an increase of hD2R at the cellular membrane after 15-h treatments with Amph. Moreover, imaging data suggested that barbadin, a specific inhibitor of the ßarrestin-ßadaptin interaction, blocked the Amph-induced increase of hD2R. Taken together our data suggest that prolonged exposures to Amph decrease or increase the endogenous hD2R at the cellular membrane in HEK293 cells expressing or lacking hDAT, respectively. Considering that this drug is often consumed for prolonged periods, during which tolerance develops, our data suggest that even in absence of DAT or dopamine, Amph can still alter D2R distribution and function.

18.
Neurochem Int ; 142: 104894, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33161093

RESUMEN

Various stimuli have been employed as reinforcers in preclinical rodent models to elucidate the underpinnings of reward at a molecular and circuit level, with the release of dopamine (DA) in the nucleus accumbens (NAc) as a well-replicated, physiological correlate. Many factors, however, including strain differences, sex, prior stress, and reinforcer administration protocols can influence reward responding and DA release. Although previous evidence indicates that access to the home cage can be an effective reinforcer in behavioral tasks, whether this simple environmental manipulation can trigger DA release in the NAc has not been demonstrated. Here, using fiber photometric recordings of in vivo NAc dopamine release from a genetically-encoded DA sensor, we show that the movement of animals from the home cage to a clear, polycarbonate recording chamber evokes little to no DA release following initial exposure whereas returning animals from the recording chamber to a clean, home-like cage or to the home cage robustly triggers the release of DA, comparable in size to that observed with a 10 mg/kg i.p. Cocaine injection in the recording chamber. Although DA release can be evoked in moving mice to a clean cage, this release was significantly augmented when moving animals from the clean cage to the home cage. Our data provide direct evidence that home cage return from a foreign environment results in a biochemical change consistent with that of a rewarding stimulus. This simple environmental manipulation provides a minimally invasive approach to study the reward circuitry underlying an ethologically relevant reinforcer, return to the safe confines of "home". The home cage - DA release paradigm may also represent a biomarker-driven paradigm for the evaluation of genetic and experiential events that underlie anhedonic states, characteristic of major mood disorders, and to present new opportunities to identify their treatments.


Asunto(s)
Dopamina/metabolismo , Vivienda para Animales , Núcleo Accumbens/metabolismo , Recompensa , Animales , Cocaína/administración & dosificación , Inhibidores de Captación de Dopamina/administración & dosificación , Masculino , Ratones , Ratones de la Cepa 129 , Ratones Endogámicos C57BL , Núcleo Accumbens/efectos de los fármacos , Fotometría/métodos
19.
J Forensic Sci ; 66(4): 1524-1532, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33942892

RESUMEN

It has already been proposed that a combined use of different molecular and morphological markers of aging in multivariate models may result in a greater accuracy of age estimation. However, such an approach can be complex and expensive, and not every combination may be useful. The significance and usefulness of combined analyses of D-aspartic acid in dentine, pentosidine in dentine, DNA methylation in buccal swabs at five genomic regions (PDE4C, RPA2, ELOVL2, DDO, and EDARADD), and third molar mineralization were tested by investigating a sample of 90 oral surgery patients. Machine learning models for age estimation were trained and evaluated, and the contribution of each parameter to multivariate models was tested by assessment of the predictor importance. For models based on D-aspartic acid, pentosidine, and the combination of both, mean absolute errors (MAEs) of 2.93, 3.41, and 2.68 years were calculated, respectively. The additional inclusion of the five DNAm markers did not improve the results. The sole DNAm-based model revealed a MAE of 4.14 years. In individuals under 28 years of age, the combination of the DNAm markers with the third molar mineralization stages reduced the MAE from 3.85 to 2.81 years. Our findings confirm that the combination of parameters in multivariate models may be very useful for age estimation. However, the inclusion of many parameters does not necessarily lead to better results. It is a task for future research to identify the best selection of parameters for the different requirements in forensic practice.


Asunto(s)
Determinación de la Edad por los Dientes/métodos , Adolescente , Adulto , Anciano , Arginina/análogos & derivados , Arginina/metabolismo , Biomarcadores/metabolismo , Niño , Islas de CpG/genética , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/metabolismo , D-Aspartato Oxidasa/metabolismo , Ácido D-Aspártico/metabolismo , Metilación de ADN , Dentina/metabolismo , Proteína de Dominio de Muerte Asociada a Edar/metabolismo , Elongasas de Ácidos Grasos/metabolismo , Humanos , Lisina/análogos & derivados , Lisina/metabolismo , Aprendizaje Automático , Persona de Mediana Edad , Tercer Molar/crecimiento & desarrollo , Análisis Multivariante , Proteína de Replicación A/metabolismo , Calcificación de Dientes , Adulto Joven
20.
Bioresour Technol ; 318: 124038, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32889125

RESUMEN

This study outlines the entire process chain related to an industrial-sized hydrothermal carbonization (HTC) plant, which treats the organic fraction of municipal solid waste. A parameter study, carried out in laboratory-scaled experiments, was used to create a model starting with the substrate preparation and ending with the production of electricity. It was designed to be infinitely variable with respect to different reaction intensities within certain boundary conditions. Contrary to previous research endeavors, all components related to the HTC process and modules for the post-treatment of co-products including heat recovery and process water treatment were integrated. Based on this model, the claim that HTC-char is a more environmentally friendly energy carrier than lignite was investigated. In the realm of a life cycle assessment, a GWP of 0.45-0.70 kg CO2,Eq/kWhel was revealed for the electricity production from HTC-char. It, thus, outcompetes the electricity production from lignite (1.05-1.40 kg CO2,Eq/kWhel).


Asunto(s)
Eliminación de Residuos , Carbono , Electricidad , Calor , Residuos Sólidos/análisis , Temperatura
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA