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1.
Radiother Oncol ; 181: 109464, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36640946

RESUMEN

BACKGROUND AND PURPOSE: To establish an international quality standard for contouring and planning for high-risk neuroblastoma within the prospective High-Risk Neuroblastoma Study 2 of SIOP-Europe-Neuroblastoma (SIOPEN HR-NBL2), which includes a randomized question on dose escalation for residual disease. MATERIALS AND METHODS: Data on four patients with high-risk neuroblastoma were selected and distributed to the radiotherapy committee of the HR-NBL2 study for independent contouring and planning. Differences in contouring were analyzed using apparent and kappa-corrected agreement. Plans were analyzed regarding the dose-volume histogram metrics. Results were discussed among experts and agreement was obtained. RESULTS: Substantial agreement was found for contouring of the heart (0.64), liver (0.70), left lung (0.74), and right lung (0.74). For contouring of the gastrointestinal tract (0.54), left kidney (0.60), and right kidney (0.59) moderate agreement was obtained. For target volume delineation, agreement for preoperative tumour extent was moderate (0.42), for CTV fair (0.35) and only low (0.06) for residual tumour, respectively. The dose planning strategies appeared to be relatively homogeneous among all experts. CONCLUSION: Considerable variability was found for the delineation of target volumes, particularly the boost volume, whereas the contouring of the organs at risk and the planning strategy were reasonably consistent. In order to obtain reliable results from the randomized HR-NBL2 trial, standardization of target volume delineation based on adequate imaging is crucial.


Asunto(s)
Neuroblastoma , Oncología por Radiación , Humanos , Planificación de la Radioterapia Asistida por Computador/métodos , Estudios Prospectivos , Pulmón , Neuroblastoma/diagnóstico por imagen , Neuroblastoma/radioterapia , Variaciones Dependientes del Observador
2.
Curr Oncol ; 30(1): 758-768, 2023 01 06.
Artículo en Inglés | MEDLINE | ID: mdl-36661707

RESUMEN

BACKGROUND: The aim of this study is to examine the dosimetric influence of endorectal balloons (ERB) on rectal sparing in prostate cancer patients with implanted hydrogel rectum spacers treated with dose-escalated or hypofractionated intensity-modulated proton beam therapy (IMPT). METHODS: Ten patients with localized prostate cancer included in the ProRegPros study and treated at our center were investigated. All patients underwent placement of hydrogel rectum spacers before planning. Two planning CTs (with and without 120 cm3 fluid-filled ERB) were applied for each patient. Dose prescription was set according to the h strategy, with 72 Gray (Gy)/2.4 Gy/5× weekly to prostate + 1 cm of the seminal vesicle, and 60 Gy/2 Gy/5× weekly to prostate + 2 cm of the seminal vesicle. Planning with two laterally opposed IMPT beams was performed in both CTs. Rectal dosimetry values including dose-volume statistics and normal tissue complication probability (NTCP) were compared for both plans (non-ERB plans vs. ERB plans). RESULTS: For ERB plans compared with non-ERB, the reductions were 8.51 ± 5.25 Gy (RBE) (p = 0.000) and 15.76 ± 11.11 Gy (p = 0.001) for the mean and the median rectal doses, respectively. No significant reductions in rectal volumes were found after high dose levels. The use of ERB resulted in significant reduction in rectal volume after receiving 50 Gy (RBE), 40 Gy (RBE), 30 Gy (RBE), 20 Gy (RBE), and 10 Gy (RBE) with p values of 0.034, 0.008, 0.003, 0.001, and 0.001, respectively. No differences between ERB and non-ERB plans for the anterior rectum were observed. ERB reduced posterior rectal volumes in patients who received 30 Gy (RBE), 20 Gy (RBE), or 10 Gy (RBE), with p values of 0.019, 0.003, and 0.001, respectively. According to the NTCP models, no significant reductions were observed in mean or median rectal toxicity (late rectal bleeding ≥ 2, necrosis or stenosis, and late rectal toxicity ≥ 3) when using the ERB. CONCLUSION: ERB reduced rectal volumes exposed to intermediate or low dose levels. However, no significant reduction in rectal volume was observed in patients receiving high or intermediate doses. There was no benefit and also no disadvantage associated with the use of ERB for late rectal toxicity, according to available NTCP models.


Asunto(s)
Neoplasias de la Próstata , Terapia de Protones , Masculino , Humanos , Recto , Terapia de Protones/métodos , Planificación de la Radioterapia Asistida por Computador/métodos , Neoplasias de la Próstata/radioterapia , Hidrogeles
3.
Neuron ; 110(18): 2949-2960.e4, 2022 09 21.
Artículo en Inglés | MEDLINE | ID: mdl-35931070

RESUMEN

Transmission from striatal cholinergic interneurons (CINs) controls dopamine release through nicotinic acetylcholine receptors (nAChRs) on dopaminergic axons. Anatomical studies suggest that cholinergic terminals signal predominantly through non-synaptic volume transmission. However, the influence of cholinergic transmission on electrical signaling in axons remains unclear. We examined axo-axonal transmission from CINs onto dopaminergic axons using perforated-patch recordings, which revealed rapid spontaneous EPSPs with properties characteristic of fast synapses. Pharmacology showed that axonal EPSPs (axEPSPs) were mediated primarily by high-affinity α6-containing receptors. Remarkably, axEPSPs triggered spontaneous action potentials, suggesting that these axons perform integration to convert synaptic input into spiking, a function associated with somatodendritic compartments. We investigated the cross-species validity of cholinergic axo-axonal transmission by recording dopaminergic axons in macaque putamen and found similar axEPSPs. Thus, we reveal that synaptic-like neurotransmission underlies cholinergic signaling onto dopaminergic axons, supporting the idea that striatal dopamine release can occur independently of somatic firing to provide distinct signaling.


Asunto(s)
Dopamina , Receptores Nicotínicos , Axones/metabolismo , Colinérgicos , Fibras Colinérgicas/metabolismo , Cuerpo Estriado/fisiología , Dopamina/fisiología , Interneuronas/metabolismo , Receptores Nicotínicos/metabolismo , Transmisión Sináptica/fisiología
4.
Stud Health Technol Inform ; 290: 512-516, 2022 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-35673068

RESUMEN

Especially in chronic diseases, such as shoulder impingement syndrome (SIS), good self-management is important for patients to take personal responsibility for their treatment and make informed decisions in rehabilitation processes. Mobile apps integrating game design elements have great potential to increase patients self-management skills. A total of 21 functionalities for a self-management app were derived from semi-structured interviews with six patients and three therapists. Thereby, welcome messages, a personalized home-screen, and training plans are rated as particular useful. Ten of these functionalities could be implemented in a first prototype of SISco: your shoulder impingement syndrome companion. SISco provides possibilities for creating and executing training programs, learning about SIS, checking daily challenges, and making diary entries. Thereby, SISco motivates patients via progress bars, collecting XP, unlocking content and Dr. SISco the virtual therapist. Future work includes the implementation of further functionalities and the evaluation of SISco for usability and user acceptance.


Asunto(s)
Aplicaciones Móviles , Automanejo , Síndrome de Abducción Dolorosa del Hombro , Telemedicina , Enfermedad Crónica , Humanos , Síndrome de Abducción Dolorosa del Hombro/terapia
5.
Radiat Oncol ; 17(1): 64, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35365170

RESUMEN

PURPOSE: To examine the dosimetric feasibility of hypofractionated/dose escalated radiation therapy in patients with localized prostate carcinoma using simultaneous integrated boost intensity-modulated proton beam therapy (SIB-IMPT) in absence or presence of prostate-rectum spacer. METHODS: IMPT technique was implemented in 23 patients with intermediate- and high-risk prostate cancer treated at West German Proton Therapy Centre from March 2016 till June 2018, using SIB technique prescribing 60 GyRBE and 72 GyRBE in 30 fractions to PTV1 (prostate and seminal vesicle) and PTV2 boost (prostate and proximal seminal vesicle), respectively. In 15 patients, a transperineal injection of hydrogel was applied prior to radiotherapy to increase the distance between prostate and rectum. Planning and all treatments were performed with a 120 ml fluid-filled endorectal balloon customised daily for each patient. For each patient, 2 lateral IMPT beams were implemented taking a field-specific range uncertainty (RU) into account. Dose volume histograms (DVH) were analyzed for PTV2, PTV2 with range uncertainty margin (PTV2RU), rectum, bladder, right/left femoral heads, and penile bulb. For late rectal toxicities, the normal tissue complication probabilities (NTCP) were calculated using different biological models. A DVH- and NTCP-based dosimetric comparison was carried out between non-spacer and spacer groups. RESULTS: For the 23 patients, high-quality plans could be achieved for target volume and for other organs at risk (OARs). For PTV2, the V107% was 0% and the Dmax did not exceed 106.2% of the prescribed dose. The volume PTV2RU covered by 95% of the dose ranged from 96.16 to 99.95%. The conformality index for PTV2RU was 1.12 ± 0.057 and the homogeneity index (HI) was 1.04 ± 0.014. Rectum Dmax and rectal volume receiving 73-50 Gy could be further reduced for the spacer-group. Significant reductions in mean and median rectal NTCPs (stenosis/necrosis, late rectal bleeding ≥ 2, and late rectal toxicities ≥ 3) were predicted for the spacer group in comparison to the non-spacer group. CONCLUSION: Hypofractionated/dose escalated radiotherapy with SIB-IMPT is dosimetrically feasible. Further reduction of the rectal volumes receiving high and medium dose levels (73-50 Gy) and rectal NTCP could be achieved through injection of spacers between rectum and prostate.


Asunto(s)
Neoplasias de la Próstata , Terapia de Protones , Estudios de Factibilidad , Humanos , Hidrogeles , Masculino , Próstata/patología , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/radioterapia , Planificación de la Radioterapia Asistida por Computador/métodos , Recto/patología
6.
Science ; 375(6587): 1378-1385, 2022 03 25.
Artículo en Inglés | MEDLINE | ID: mdl-35324301

RESUMEN

Information flow in neurons proceeds by integrating inputs in dendrites, generating action potentials near the soma, and releasing neurotransmitters from nerve terminals in the axon. We found that in the striatum, acetylcholine-releasing neurons induce action potential firing in distal dopamine axons. Spontaneous activity of cholinergic neurons produced dopamine release that extended beyond acetylcholine-signaling domains, and traveling action potentials were readily recorded from dopamine axons in response to cholinergic activation. In freely moving mice, dopamine and acetylcholine covaried with movement direction. Local inhibition of nicotinic acetylcholine receptors impaired dopamine dynamics and affected movement. Our findings uncover an endogenous mechanism for action potential initiation independent of somatodendritic integration and establish that this mechanism segregates the control of dopamine signaling between axons and somata.


Asunto(s)
Potenciales de Acción , Axones , Neuronas Colinérgicas , Cuerpo Estriado , Dopamina , Transmisión Sináptica , Acetilcolina/metabolismo , Animales , Axones/fisiología , Neuronas Colinérgicas/metabolismo , Cuerpo Estriado/fisiología , Dopamina/metabolismo , Ratones , Receptores Nicotínicos/fisiología
8.
Neuro Oncol ; 24(7): 1193-1202, 2022 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-34964901

RESUMEN

BACKGROUND: Radiotherapy (RT) of ependymoma in children is an important part of the interdisciplinary treatment concept. However, feasibility and dose concepts are still under investigation, particularly in very young children. The aim of this study was to evaluate the standard dose and volume of proton therapy (PT) in children with ependymoma. METHODS: In this analysis, 105 patients with localized, intracranial ependymoma under the age of 18 years treated with PT between 2013 and 2018 were included. Patient characteristics, treatment, outcome, and follow-up data were analyzed using descriptive statistics, Kaplan-Meier, and Cox regression analysis. RESULTS: The median age of patients at PT was 2.8 years (0.9-17.0 years). The molecular subgroup analysis was performed in a subset of 50 patients (37 EP-PFA, 2 EP-PFB, 7 EP-RELA, 2 EP-YAP, 2 NEC [not elsewhere classified]). The median total dose was 59.4 Gy (54.0-62.0 Gy). The median follow-up time was 1.9 years. The estimated 3-year overall survival (OS), local control (LC), and progression-free survival (PFS) rates were 93.7%, 74.1%, and 55.6%, respectively. Within univariable analysis, female gender and lower dose had a positive impact on OS, whereas age ≥4 years had a negative impact on OS and PT given after progression had a negative impact on PFS. In the multivariable analysis, multiple tumor surgeries were associated with lower PFS. New ≥3° late toxicities occurred in 11 patients. CONCLUSION: For children with localized ependymoma, PT was effective and well tolerable. Multiple surgeries showed a negative impact on PFS.


Asunto(s)
Neoplasias Encefálicas , Ependimoma , Terapia de Protones , Adolescente , Neoplasias Encefálicas/patología , Niño , Preescolar , Ependimoma/patología , Ependimoma/radioterapia , Femenino , Humanos , Estudios Prospectivos , Resultado del Tratamiento
9.
Front Oncol ; 11: 599018, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34055596

RESUMEN

Proton therapy makes use of the favorable depth-dose distribution with its characteristic Bragg peak to spare normal tissue distal of the target volume. A steep dose gradient would be desired in lateral dimensions, too. The widespread spot scanning delivery technique is based, however, on pencil-beams with in-air spot full-widths-at-half-maximum of typically 1 cm or more. This hampers the sparing of organs-at-risk if small-scale structures adjacent to the target volume are concerned. The trimming of spot scanning fields with collimating apertures constitutes a simple measure to increase the transversal dose gradient. The current study describes the clinical implementation of brass apertures in conjunction with the pencil-beam scanning delivery mode at a horizontal, clinical treatment head based on commercial hardware and software components. Furthermore, clinical cases, which comprised craniopharyngiomas, re-irradiations and ocular tumors, were evaluated. The dosimetric benefits of 31 treatment plans using apertures were compared to the corresponding plans without aperture. Furthermore, an overview of the radiation protection aspects is given. Regarding the results, robust optimization considering range and setup uncertainties was combined with apertures. The treatment plan optimizations followed a single-field uniform dose or a restricted multi-field optimization approach. Robustness evaluation was expanded to account for possible deviations of the center of the pencil-beam delivery and the mechanical center of the aperture holder. Supplementary apertures improved the conformity index on average by 15.3%. The volume of the dose gradient surrounding the PTV (evaluated between 80 and 20% dose levels) was decreased on average by 17.6%. The mean dose of the hippocampi could be reduced on average by 2.9 GyRBE. In particular cases the apertures facilitated a sparing of an organ-at-risk, e.g. the eye lens or the brainstem. For six craniopharyngioma cases the inclusion of apertures led to a reduction of the mean dose of 1.5 GyRBE (13%) for the brain and 3.1 GyRBE (16%) for the hippocampi.

10.
Elife ; 92020 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-32870779

RESUMEN

Axons of dopaminergic neurons innervate the striatum where they contribute to movement and reinforcement learning. Past work has shown that striatal GABA tonically inhibits dopamine release, but whether GABA-A receptors directly modulate transmission or act indirectly through circuit elements is unresolved. Here, we use whole-cell and perforated-patch recordings to test for GABA-A receptors on the main dopaminergic neuron axons and branching processes within the striatum of adult mice. Application of GABA depolarized axons, but also decreased the amplitude of axonal spikes, limited propagation and reduced striatal dopamine release. The mechanism of inhibition involved sodium channel inactivation and shunting. Lastly, we show the positive allosteric modulator diazepam enhanced GABA-A currents on dopaminergic axons and directly inhibited release, but also likely acts by reducing excitation from cholinergic interneurons. Thus, we reveal the mechanisms of GABA-A receptor modulation of dopamine release and provide new insights into the actions of benzodiazepines within the striatum.


Asunto(s)
Cuerpo Estriado/fisiología , Diazepam/farmacología , Inhibición Neural , Receptores de GABA-A , Animales , Benzodiazepinas/farmacología , Neuronas Colinérgicas/efectos de los fármacos , Dopamina/metabolismo , Neuronas Dopaminérgicas/efectos de los fármacos , Neuronas Dopaminérgicas/metabolismo , Ratones , Inhibición Neural/efectos de los fármacos , Inhibición Neural/fisiología , Receptores de GABA-A/efectos de los fármacos , Receptores de GABA-A/metabolismo , Canales de Sodio/metabolismo , Ácido gamma-Aminobutírico/metabolismo
11.
PLoS One ; 12(11): e0187732, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29117230

RESUMEN

Neuronal cells receive a variety of excitatory and inhibitory signals which they process to generate an output signal. In order to study the interaction between excitatory and inhibitory receptors with exogenously applied transmitters in the same preparation, two caging chromophores attached to glutamate and GABA were developed that were selectively photolyzed by different wavelengths of light. This technique has the advantage that the biologically inactive caged compound can be applied at equilibrium prior to the near instantaneous release of the transmitters. This method therefore mimics the kinetics of endogenously released transmitters that is otherwise not possible in brain slice preparations. Repeated photolysis with either of the two wavelengths resulted in GABA- or glutamate-induced activation of both ionotropic and metabotropic receptors to evoke reproducible currents. With these compounds, the interaction between inhibitory and excitatory receptors was examined using whole field photolysis.


Asunto(s)
Ácido Glutámico/metabolismo , Neuronas/metabolismo , Fotones , Receptores de GABA/metabolismo , Receptores de Glutamato Metabotrópico/metabolismo , Ácido gamma-Aminobutírico/metabolismo , Potenciales de Acción/fisiología , Animales , Compuestos de Bifenilo/química , Color , Cumarinas/química , Femenino , Colorantes Fluorescentes/química , Expresión Génica , Glutamatos/química , Ácido Glutámico/química , Hipocampo/citología , Hipocampo/metabolismo , Masculino , Microtomía , Neuronas/citología , Técnicas de Placa-Clamp , Fotólisis , Ratas , Ratas Sprague-Dawley , Receptores de GABA/genética , Receptores de Glutamato Metabotrópico/genética , Sustancia Negra/citología , Sustancia Negra/metabolismo , Técnicas de Cultivo de Tejidos , Ácido gamma-Aminobutírico/química
12.
Cell Rep ; 17(12): 3246-3255, 2016 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-28009293

RESUMEN

Synaptic transmission is mediated by ionotropic and metabotropic receptors that together regulate the rate and pattern of action potential firing. Metabotropic receptors can activate ion channels and modulate other receptors and channels. The present paper examines the interaction between group 1 mGluR-mediated calcium release from stores and GABAB/D2-mediated GIRK currents in rat dopamine neurons of the Substantia Nigra. Transient activation of mGluRs decreased the GIRK current evoked by GABAB and D2 receptors, although less efficaciously for D2. The mGluR-induced inhibition of GIRK current peaked in 1 s and recovered to baseline after 5 s. The inhibition was dependent on release of calcium from stores, was larger for transient than for tonic currents, and was unaffected by inhibitors of PLC, PKC, PLA2, or calmodulin. This inhibition of GABAB IPSCs through release of calcium from stores is a postsynaptic mechanism that may broadly reduce GIRK-dependent inhibition of many central neurons.


Asunto(s)
Neuronas Dopaminérgicas/metabolismo , Canales de Potasio Rectificados Internamente Asociados a la Proteína G/metabolismo , Receptores de Dopamina D2/metabolismo , Receptores de GABA-B/metabolismo , Receptores de Glutamato Metabotrópico/metabolismo , Potenciales de Acción/fisiología , Animales , Calcio/metabolismo , Calmodulina/metabolismo , Dopamina/metabolismo , Canales de Potasio Rectificados Internamente Asociados a la Proteína G/genética , Proteína Quinasa C/metabolismo , Ratas , Sustancia Negra/metabolismo , Sustancia Negra/fisiología , Transmisión Sináptica/genética , Transmisión Sináptica/fisiología , Fosfolipasas de Tipo C/metabolismo
13.
Neuropsychopharmacology ; 40(10): 2418-24, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25829143

RESUMEN

Midbrain dopamine neurons are important mediators of reward and movement and are sensitive to cocaine-induced plasticity. After even a single injection of cocaine, there is an increase in AMPA-dependent synaptic transmission. The present study examines cocaine-induced plasticity of mGluR-dependent currents in dopamine neurons in the substantia nigra. Activation of mGluR1 and mGluR5 resulted in a mixture of inward and outward currents mediated by a nonselective cation conductance and a calcium-activated potassium conductance (SK), respectively. A single injection of cocaine decreased the current activated by mGluR1 in dopamine neurons, and it had no effect on the size of the mGluR5-mediated current. When the injection of cocaine was preceded by treatment of the animals with a blocker of mGluR5 receptors (MPEP), cocaine no longer decreased the mGluR1 current. Thus, the activation of mGluR5 was required for the cocaine-mediated suppression of mGluR1-mediated currents in dopamine neurons. The results support the hypothesis that mGluR5 coordinates a reduction in mGluR1 functional activity after cocaine treatment.


Asunto(s)
Cocaína/farmacología , Inhibidores de Captación de Dopamina/farmacología , Neuronas Dopaminérgicas/efectos de los fármacos , Neuronas Dopaminérgicas/metabolismo , Receptor del Glutamato Metabotropico 5/metabolismo , Receptores de Glutamato Metabotrópico/metabolismo , Potenciales de Acción/efectos de los fármacos , Animales , Fármacos actuantes sobre Aminoácidos Excitadores/farmacología , Femenino , Técnicas In Vitro , Iontoforesis , Masculino , Metoxihidroxifenilglicol/análogos & derivados , Metoxihidroxifenilglicol/farmacología , Ratones , Ratones Endogámicos C57BL , Técnicas de Placa-Clamp , Bloqueadores de los Canales de Potasio/farmacología , Canales de Potasio de Pequeña Conductancia Activados por el Calcio/metabolismo , Sustancia Negra/citología
14.
Nat Neurosci ; 16(5): 632-8, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23542690

RESUMEN

A hallmark of addiction is the loss of control over drug intake, which is seen in only a fraction of those exposed to stimulant drugs such as cocaine. The cellular mechanisms underlying vulnerability or resistance to compulsive drug use remain unknown. We found that individual variability in the development of highly motivated and perseverative behavior toward cocaine is associated with synaptic plasticity in medium spiny neurons expressing dopamine D2 receptors (D2-MSNs) in the nucleus accumbens (NAc) of mice. Potentiation of glutamatergic inputs onto indirect pathway D2-MSNs was associated with resilience toward compulsive cocaine seeking. Inhibition of D2-MSNs using a chemicogenetic approach enhanced the motivation to obtain cocaine, whereas optogenetic activation of D2-MSNs suppressed cocaine self-administration. These results indicate that recruitment of D2-MSNs in NAc functions to restrain cocaine self-administration and serves as a natural protective mechanism in drug-exposed individuals.


Asunto(s)
Cocaína/administración & dosificación , Conducta Compulsiva/fisiopatología , Inhibidores de Captación de Dopamina/administración & dosificación , Vías Nerviosas/fisiología , Núcleo Accumbens/fisiología , Animales , Proteínas Bacterianas/genética , Channelrhodopsins , Clozapina/análogos & derivados , Clozapina/farmacología , Conducta Compulsiva/genética , Potenciales Postsinápticos Excitadores/efectos de los fármacos , Potenciales Postsinápticos Excitadores/fisiología , Proteínas Fluorescentes Verdes/genética , Proteínas Luminiscentes/genética , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , N-Metilaspartato/metabolismo , Red Nerviosa/efectos de los fármacos , Red Nerviosa/fisiología , Vías Nerviosas/efectos de los fármacos , Neuronas/citología , Neuronas/efectos de los fármacos , Neuronas/fisiología , Núcleo Accumbens/citología , Núcleo Accumbens/efectos de los fármacos , Receptores de Dopamina D2/genética , Recompensa , Autoadministración , Sinapsis/efectos de los fármacos , Sinapsis/fisiología , Factores de Tiempo , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiónico/metabolismo
15.
Gynecol Oncol ; 127(1): 121-5, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22796462

RESUMEN

OBJECTIVE: Chemoradiation is the mainstay of therapy for advanced cervical cancer, with the most effective treatment regimens involving combinations of radiosensitizing agents. However, administration of radiosensitizing chemotherapeutics concurrently with pelvic radiation is not without side effects. The aim of this study was to examine the utility of localized drug delivery as a means of improving drug targeting of radiosensitizing chemotherapeutics to the cervix while limiting systemic toxicities. METHODS: An initial proof-of-concept study was performed in 14 healthy women following local administration of diazepam utilizing a novel cervical delivery device (CerviPrep™). Uterine vein and peripheral blood samples were collected and diazepam was measured using a GC-MS method. In the follow-up study, gemcitabine was applied to the cervix in 17 women undergoing hysterectomy for various gynecological malignancies. Cervical tissue, uterine vein blood samples, and peripheral plasma were collected, and gemcitabine and its deaminated metabolite 2',2'-difluorodeoxyuridine (dFdU) were measured using HPLC-UV and LC/MS methods. RESULTS: Targeted delivery of diazepam to the cervix was consistent with parent drug detectable in the uterine vein of 13 of 14 women. In the second study, pharmacologically relevant concentrations of gemcitabine (0.01-6.6 nmol/g tissue) were detected in the cervical tissue of 11 of 16 available specimens with dFdU measureable in 15 samples (0.04-8.8 nmol/g tissue). Neither gemcitabine nor its metabolites were detected in the peripheral plasma of any subject. CONCLUSIONS: Localized drug delivery to the cervix is possible and may be useful in limiting toxicity associated with intravenous administration of chemotherapeutics for radiosensitization.


Asunto(s)
Cuello del Útero/efectos de los fármacos , Cuello del Útero/metabolismo , Desoxicitidina/análogos & derivados , Diazepam/administración & dosificación , Neoplasias de los Genitales Femeninos/tratamiento farmacológico , Neoplasias de los Genitales Femeninos/cirugía , Antimetabolitos Antineoplásicos/administración & dosificación , Antimetabolitos Antineoplásicos/sangre , Antimetabolitos Antineoplásicos/farmacocinética , Cuello del Útero/cirugía , Desoxicitidina/administración & dosificación , Desoxicitidina/sangre , Desoxicitidina/farmacocinética , Diazepam/sangre , Diazepam/farmacocinética , Sistemas de Liberación de Medicamentos , Interacciones Farmacológicas , Femenino , Neoplasias de los Genitales Femeninos/metabolismo , Humanos , Fármacos Sensibilizantes a Radiaciones/administración & dosificación , Fármacos Sensibilizantes a Radiaciones/farmacocinética , Gemcitabina
16.
J Neurosci ; 31(1): 126-32, 2011 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-21209197

RESUMEN

Bacteria artificial chromosome (BAC) transgenic mice expressing the reporter protein enhanced green fluorescent protein (EGFP) under the control of the D1 and D2 dopamine receptor promoters (Drd1-EGFP and Drd2-EGFP) have been widely used to study striatal function and have contributed to our understanding of the physiological and pathological functions of the basal ganglia. These tools were produced and promptly made available to address questions in a cell-specific manner that has transformed the way we frame hypotheses in neuroscience. However, these mice have not been fully characterized until now. We found that Drd2-EGFP mice display an ∼40% increase in membrane expression of the dopamine D2 receptor (D2R) and a twofold increase in D2R mRNA levels in the striatum when compared with wild-type and Drd1-EGFP mice. D2R overexpression was accompanied by behavioral hypersensitivity to D2R-like agonists, as well as enhanced electrophysiological responses to D2R activation in midbrain dopaminergic neurons. Dopamine (DA) transients evoked by stimulation in the nucleus accumbens showed slower clearance in Drd2-EGFP mice, and cocaine actions on DA clearance were impaired in these mice. Thus, it was not surprising to find that Drd2-EGFP mice were hyperactive when exposed to a novel environment and locomotion was suppressed by acute cocaine administration. All together, this study demonstrates that Drd2-EGFP mice overexpress D2R and have altered dopaminergic signaling that fundamentally differentiates them from wild-type and Drd1-EGFP mice.


Asunto(s)
Regulación de la Expresión Génica/genética , Receptores de Dopamina D2/genética , Receptores de Dopamina D2/metabolismo , Animales , Repetición de Anquirina/genética , Conducta Animal/fisiología , Cocaína/farmacología , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/metabolismo , Agonistas de Dopamina/farmacología , Inhibidores de Captación de Dopamina/farmacología , Relación Dosis-Respuesta a Droga , Electroquímica/métodos , Proteínas Fluorescentes Verdes/genética , Técnicas In Vitro , Locomoción/efectos de los fármacos , Ratones , Ratones Transgénicos , Neuronas/efectos de los fármacos , Neuronas/fisiología , Unión Proteica/efectos de los fármacos , Quinpirol/farmacología , ARN Mensajero/metabolismo , Ensayo de Unión Radioligante/métodos , Receptores de Dopamina D1/genética , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Estadísticas no Paramétricas , Factores de Tiempo , Área Tegmental Ventral/citología
17.
JACC Cardiovasc Interv ; 2(7): 594-600, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19628179

RESUMEN

OBJECTIVES: The aim of this study was to determine 5-year clinical status for patients treated with percutaneous left atrial appendage transcatheter occlusion with the PLAATO (Percutaneous Left Atrial Appendage Transcatheter Occlusion) system. BACKGROUND: Anticoagulation reduces thromboembolism among patients with nonvalvular atrial fibrillation (AF). However, warfarin is a challenging medication due to risks of inadequate anticoagulation and bleeding. Thus, PLAATO was evaluated as a treatment strategy for nonwarfarin candidate patients with AF at high risk for stroke. METHODS: Sixty-four patients with permanent or paroxysmal AF participated in this observational, multicenter prospective study. Primary end points were: new major or minor stroke, cardiac or neurological death, myocardial infarction, or requirement for cardiovascular surgery related to the procedure within 1 month of the index procedure. Patients were followed for up to 5 years. RESULTS: Thirty-day freedom from major adverse events rate was 98.4% (95% confidence interval: 90.89% to >99.99%). One patient, who did not receive a PLAATO implant, experienced 2 events within 30 days (cardiovascular surgery, death). Treatment success was 100% 1 month after device implantation. At 5-year follow-up, there were 7 deaths, 5 major strokes, 3 minor strokes, 1 cardiac tamponade requiring surgery, 1 probable cerebral hemorrhage/death, and 1 myocardial infarction. Only 1 event (cardiac tamponade) was adjudicated as related to the implant procedure. After up to 5 years of follow-up, the annualized stroke/transient ischemic attack (TIA) rate was 3.8%. The anticipated stroke/TIA rate (with the CHADS(2) scoring method) was 6.6%/year. CONCLUSIONS: The PLAATO system is safe and effective. At 5-year follow-up the annualized stroke/TIA rate in our patients was 3.8%/year, less than predicted by the CHADS(2) scoring system.


Asunto(s)
Anticoagulantes/uso terapéutico , Fibrilación Atrial/terapia , Cateterismo Cardíaco/métodos , Accidente Cerebrovascular/prevención & control , Tromboembolia/prevención & control , Warfarina/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Apéndice Atrial , Fibrilación Atrial/complicaciones , Fibrilación Atrial/tratamiento farmacológico , Fibrilación Atrial/mortalidad , Canadá/epidemiología , Cateterismo Cardíaco/efectos adversos , Cateterismo Cardíaco/instrumentación , Cateterismo Cardíaco/mortalidad , Procedimientos Quirúrgicos Cardíacos , Cineangiografía , Ecocardiografía Doppler en Color , Ecocardiografía Transesofágica , Diseño de Equipo , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/etiología , Estudios Prospectivos , Medición de Riesgo , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/mortalidad , Tromboembolia/etiología , Tromboembolia/mortalidad , Factores de Tiempo , Insuficiencia del Tratamiento , Estados Unidos/epidemiología
19.
EuroIntervention ; 4(4): 437-42, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19284064

RESUMEN

AIMS: Percutaneous repair of mitral regurgitation (MR) by leaflet apposition using a clip deployed via transseptal catheterisation is undergoing evaluation. METHODS AND RESULTS: In order to detect the potential for clinically significant left ventricular inflow obstruction after percutaneous repair, we measured mitral valve area (MVA) and mean transmitral gradient (MVG) echocardiographically in 96 patients implanted with a clip followed for up to 24 months. By planimetry, the mean MVA decreased from 6.0 +/- 1.3 cm2 to 3.6 +/- 1.2 cm2 (p < 0.05) (range 1.9 to 7.6 cm2) after clip placement, and remained unchanged after 24 months of follow-up (3.5 +/- 0.8 cm2). The mean MVG increased after clip placement from 1.7 +/- 0.9 mmHg to 4.1 +/- 2.2 mmHg (p < 0.05), and did not increase further to 24 months (3.8 +/- 1.9 mmHg). There were no differences in MVA or MVG between patients who received 1-clip (69%) and those receiving 2-clips (31%). Patients with functional MR (23%) had a slightly smaller MVA, both at baseline and after clip placement, but did not differ from degenerative MR patients at later follow-up. After 2 years of follow-up, no patient required surgery for LV inflow obstruction. CONCLUSIONS: Mitral repair with the MitraClip device for MR decreases MVA without significant mitral obstruction. After 2 years of follow-up, no patient required surgery for LV inflow obstruction, and these results were not influenced by the use of more than 1 clip or the aetiology of MR.


Asunto(s)
Cateterismo Cardíaco/instrumentación , Insuficiencia de la Válvula Mitral/terapia , Instrumentos Quirúrgicos , Anciano , Anciano de 80 o más Años , Cateterismo Cardíaco/efectos adversos , Ecocardiografía Doppler , Femenino , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia de la Válvula Mitral/diagnóstico por imagen , Sistema de Registros , Factores de Tiempo , Resultado del Tratamiento , Obstrucción del Flujo Ventricular Externo/etiología
20.
J Reprod Med ; 53(6): 441-8, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18664063

RESUMEN

OBJECTIVE: To determine the efficacy of a self-test device for obtaining vaginal/cervical samples for HPV DNA and cytologic testing. STUDY DESIGN: We recruited 878 Appalachian women; 775 were able to submit a self-test sample and a provider-collected sample. Each specimen was assessed for cytologic abnormalities and for high-risk HPV infection. RESULTS: Specimen adequacy: 869 of 878 (99%) women had sufficient material for cytologic analysis in provider-collected samples compared to 771 of 775 (99%) self-collected specimens (p = NS). There was sufficient cellular material (DNA) for HPV testing in 724 of 834 (87%) provider-collected samples compared to 690 of 736 (94%) self-collected specimens (p <0.04). In the provider-collected samples, 654 of 869 (75%) women had endocervical cells compared to 103 of 771 (13%) self-collected specimens (p <0.001). HPV assessment: 142 (19%) had high-risk HPV DNA detected. Of those women, 28 (20%) had HPV infection detected on the provider-collected specimen only, 51 (36%) on the self-collected specimen only, and 63 (44%) had HPV DNA on both specimens. CONCLUSION: Our device is sufficient to obtain an adequate number of epithelial cells for cytologic and HPV testing.


Asunto(s)
Tamizaje Masivo/instrumentación , Infecciones por Papillomavirus/diagnóstico , Servicios de Salud Rural , Autoexamen/instrumentación , Frotis Vaginal/instrumentación , Adulto , Región de los Apalaches , Estudios de Cohortes , Femenino , Humanos , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados
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