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1.
Neurosurg Rev ; 47(1): 114, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38480549

RESUMO

Supplementary motor area syndrome (SMAS) represents a common neurosurgical sequela. The incidence and time frame of its occurrence have yet to be characterized after surgery for brain tumors. We examined patients suffering from a brain tumor preoperatively, postoperatively, and during follow-up examinations after three months, including fine motor skills testing and transcranial magnetic stimulation (TMS). 13 patients suffering from a tumor in the dorsal part of the superior frontal gyrus underwent preoperative, early postoperative, and 3-month follow-up testing of fine motor skills using the Jebsen-Taylor Hand Function Test (JHFT) and the Nine-Hole Peg Test (NHPT) consisting of 8 subtests for both upper extremities. They completed TMS for cortical motor function mapping. Test completion times (TCTs) were recorded and compared. No patient suffered from neurological deficits before surgery. On postoperative day one, we detected motor deficits in two patients, which remained clinically stable at a 3-month follow-up. Except for page-turning, every subtest indicated a significant worsening of function, reflected by longer TCTs (p < 0.05) in the postoperative examinations for the contralateral upper extremity (contralateral to the tumor manifestation). At 3-month follow-up examinations for the contralateral upper extremity, each subtest indicated significant worsening compared to the preoperative status despite improvement to the immediate postoperative level. We also detected significantly longer TCTs (p < 0.05) postoperatively in the ipsilateral upper extremity. This study suggests a long-term worsening of fine motor skills even three months after SMA tumor resection, indicating the necessity of targeted physical therapy for these patients.


Assuntos
Neoplasias Encefálicas , Córtex Motor , Humanos , Córtex Motor/cirurgia , Destreza Motora , Neoplasias Encefálicas/etiologia , Estimulação Magnética Transcraniana , Procedimentos Neurocirúrgicos/efeitos adversos
2.
J Neurooncol ; 161(1): 107-115, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36566460

RESUMO

PURPOSE: Intradural spinal hemangioblastomas are rare highly hypervascularized benign neoplasms. Surgical resection remains the treatment of choice, with a significant risk of postoperative neurological deterioration. Due to the tumor infrequency, scientific evidence is scarce and limited to case reports and small case series. METHODS: We performed a retrospective multicenter study including five high-volume neurosurgical centers analyzing patients surgically treated for spinal hemangioblastomas between 2006 and 2021. We assessed clinical status, surgical data, preoperative angiograms, and embolization when available. Follow-up records were analyzed, and logistic regression performed to assess possible risk factors for neurological deterioration. RESULTS: We included 60 patients in Germany and Austria. Preoperative angiography was performed in 30% of the cases; 10% of the patients underwent preoperative embolization. Posterior tumor location and presence of a syrinx favored gross total tumor resection (93.8% vs. 83.3% and 97.1% vs. 84%). Preoperative embolization was not associated with postoperative worsening. The clinical outcome revealed a transient postoperative neurological deterioration in 38.3%, depending on symptom duration and preoperative modified McCormick grading, but patients recovered in most cases until follow-up. CONCLUSION: Spinal hemangioblastoma patients significantly benefit from early surgical treatment with only transient postoperative deterioration and complete recovery until follow-up. The performance of preoperative angiograms remains subject to center disparities.


Assuntos
Hemangioblastoma , Neoplasias da Medula Espinal , Humanos , Hemangioblastoma/diagnóstico por imagem , Hemangioblastoma/cirurgia , Estudos Retrospectivos , Neoplasias da Medula Espinal/diagnóstico por imagem , Neoplasias da Medula Espinal/cirurgia , Procedimentos Neurocirúrgicos , Angiografia , Resultado do Tratamento
3.
Am J Physiol Endocrinol Metab ; 322(2): E85-E100, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34927460

RESUMO

Activation of uncoupling protein 1 (UCP1) in brown adipose tissue (BAT) upon cold stimulation leads to substantial increase in energy expenditure to defend body temperature. Increases in energy expenditure after a high-caloric food intake, termed diet-induced thermogenesis, are also attributed to BAT. These properties render BAT a potential target to combat diet-induced obesity. However, studies investigating the role of UCP1 to protect against diet-induced obesity are controversial and rely on the phenotyping of a single constitutive UCP1-knockout model. To address this issue, we generated a novel UCP1-knockout model by Cre-mediated deletion of exon 2 in the UCP1 gene. We studied the effect of constitutive UCP1 knockout on metabolism and the development of diet-induced obesity. UCP1 knockout and wild-type mice were housed at 30°C and fed a control diet for 4 wk followed by 8 wk of high-fat diet. Body weight and food intake were monitored continuously over the course of the study, and indirect calorimetry was used to determine energy expenditure during both feeding periods. Based on Western blot analysis, thermal imaging and noradrenaline test, we confirmed the lack of functional UCP1 in knockout mice. However, body weight gain, food intake, and energy expenditure were not affected by loss of UCP1 function during both feeding periods. We introduce a novel UCP1-KO mouse enabling the generation of conditional UCP1-knockout mice to scrutinize the contribution of UCP1 to energy metabolism in different cell types or life stages. Our results demonstrate that UCP1 does not protect against diet-induced obesity at thermoneutrality.NEW & NOTEWORTHY We provide evidence that the abundance of UCP1 does not influence energy metabolism at thermoneutrality studying a novel Cre-mediated UCP1-KO mouse model. This model will be a foundation for a better understanding of the contribution of UCP1 in different cell types or life stages to energy metabolism.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Obesidade/etiologia , Obesidade/metabolismo , Temperatura , Proteína Desacopladora 1/metabolismo , Tecido Adiposo Marrom/metabolismo , Animais , Calorimetria Indireta/métodos , Suscetibilidade a Doenças/metabolismo , Ingestão de Alimentos/genética , Metabolismo Energético/genética , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Obesidade/genética , Termogênese/genética , Proteína Desacopladora 1/genética , Aumento de Peso/genética
4.
Int J Mol Sci ; 23(24)2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36555547

RESUMO

Acute myeloid leukemia (AML) is a hematological malignancy characterized by clonal expansion of stem and myeloid progenitor cells. Immunotherapy has revolutionized the care for other cancers such as solid tumors and lymphomas, and has the potential to effectively treat AML. There has been substantial progress in the developments of immunotherapeutic approaches for AML over the last several years, including the development of antibodies that further increase the innate immunogenicity of leukemia cells by the inhibition of NKG2D ligand-particularly MICA and MICB-shedding, chimeric proteins such as IL-15 superagonist that expand natural killer (NK) cells, blockers of immunologic checkpoints such as NKG2A, and chemicals that indirectly increase expression of immune stimulatory proteins in leukemia stem cells. Furthermore, cellular therapies have been designed to enable alloreactive immunity by allogeneic NK cells or target leukemia antigens such as mutated NPM1. These immunotherapeutic approaches have demonstrated remarkable efficacies in preclinical studies and have successfully transitioned to early phase clinical trials, to establish safety and initial signal of clinical activity. Here, we briefly discuss some of the most recent and impactful developments in the AML immunotherapy field and provide our perspectives for the future directions of this exciting and new therapeutic opportunity.


Assuntos
Leucemia Mieloide Aguda , Subfamília K de Receptores Semelhantes a Lectina de Células NK , Humanos , Ligantes , Subfamília K de Receptores Semelhantes a Lectina de Células NK/metabolismo , Leucemia Mieloide Aguda/metabolismo , Células Matadoras Naturais , Imunoterapia
5.
Cancer Immunol Immunother ; 70(9): 2483-2496, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33538861

RESUMO

Owing to their key role in several diseases including cancer, activating and inhibitory immune checkpoint molecules are increasingly exploited as targets for immunotherapy. Recently, we demonstrated that platelets, which largely influence tumor progression and immune evasion, functionally express the ligand of the checkpoint molecule GITR. This immunoreceptor modulates effector functions of T cells and NK cells with its function varying dependent on cellular context and activation state. Here, we provide a comparative analysis of platelet-derived GITRL (pGITRL) in breast cancer patients and healthy volunteers. The levels of pGITRL were found to be higher on platelets derived from cancer patients and appeared to be specifically regulated during tumor progression as exemplified by several clinical parameters including tumor stage/grade, the occurrence of metastases and tumor proliferation (Ki67) index. In addition, we report that pGITRL is upregulated during platelet maturation and particularly induced upon exposure to tumor-derived soluble factors. Our data indicate that platelets modulate the GITR/GITRL immune checkpoint in the context of malignant disease and provide a rationale to further study the GITR/GITRL axis for exploitation for immunotherapeutic intervention in cancer patients.


Assuntos
Plaquetas/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas de Checkpoint Imunológico/genética , Fatores de Necrose Tumoral/genética , Biomarcadores Tumorais , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Citometria de Fluxo , Proteína Relacionada a TNFR Induzida por Glucocorticoide/genética , Proteína Relacionada a TNFR Induzida por Glucocorticoide/metabolismo , Humanos , Proteínas de Checkpoint Imunológico/metabolismo , Imunofenotipagem , Linfócitos/imunologia , Linfócitos/metabolismo , Razão de Chances , Ativação Plaquetária , Agregação Plaquetária , Fatores de Necrose Tumoral/metabolismo
6.
J Physiol ; 598(23): 5317-5332, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32880976

RESUMO

KEY POINTS: Neurons of the enteric submucous plexus are challenged by osmolar fluctuations during digestion and absorption of nutrients. Central neurons are very sensitive to changes in osmolality but knowledge on that issue related to enteric neurons is sparse. The present study focuses on investigation of osmosensitivity of submucosal neurons including potential molecular mediating mechanisms. Results show that submucosal neurons respond to hypoosmolar stimuli with increased activity which is partially mediated by the transient receptor potential vanilloid 4 channel. We provided important information on osmosensitive properties of enteric neurons. These data are fundamental to better explain the nerve-mediated control of the gastrointestinal functions during physiological and pathophysiological (diarrhoea) conditions. ABSTRACT: Enteric neurons are located inside the gut wall, where they are confronted with changes in osmolality during (inter-) digestive periods. In particular, neurons of the submucous plexus (SMP), located between epithelial cells and blood vessels may sense and respond to osmotic shifts. The present study was conducted to investigate osmosensitivity of enteric submucosal neurons and the potential role of the transient receptor potential vanilloid 4 channel (TRPV4) as a mediator of enteric neuronal osmosensitivity. Therefore, freshly dissected submucosal preparations from guinea pig colon were investigated for osmosensitivity using voltage-sensitive dye and Ca2+ imaging. Acute hypoosmolar stimuli (final osmolality reached at ganglia of 94, 144 and 194 mOsm kg-1 ) were applied to single ganglia using a local perfusion system. Expression of TRPV4 in the SMP was quantified using qRT-PCR, and GSK1016790A and HC-067047 were used to activate or block the receptor, respectively, revealing its relevance in enteric osmosensitivity. On average, 11.0 [7.0/17.0] % of submucosal neurons per ganglion responded to the hypoosmolar stimulus. The Ca2+ imaging experiments showed that glia responded to the hypoosmolar stimulus, but with a delay in comparison with neurons. mRNA expression of TRPV4 could be shown in the SMP and blockade of the receptor by HC-067047 significantly decreased the number of responding neurons (0.0 [0.0/6.3] %) while the TRPV4 agonist GSK1016790A caused action potential discharge in a subpopulation of osmosensitive enteric neurons. The results of the present study provide insight into the osmosensitivity of submucosal enteric neurons and strongly indicate the involvement of TRPV4 as an osmotransducer.


Assuntos
Plexo Mientérico , Plexo Submucoso , Animais , Colo , Cobaias , Neuroglia , Neurônios
7.
Am J Physiol Endocrinol Metab ; 318(2): E198-E215, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31714796

RESUMO

Uncoupling protein 1 (Ucp1) provides nonshivering thermogenesis (NST) fueled by the dissipation of energy from macronutrients in brown and brite adipocytes. The availability of thermogenic fuels is facilitated by the uptake of extracellular glucose. This conjunction renders thermogenic adipocytes in brown and white adipose tissue (WAT) a potential target against obesity and glucose intolerance. We employed wild-type (WT) and Ucp1-ablated mice to elucidate this relationship. In three experiments of similar setup, Ucp1-ablated mice fed a high-fat diet (HFD) had either reduced or similar body mass gain, food intake, and metabolic efficiency compared with WT mice, challenging the hypothesized role of this protein in the development of diet-induced obesity. Despite the absence of increased body mass, oral glucose tolerance was robustly impaired in Ucp1-ablated mice in response to HFD. Postprandial glucose uptake was attenuated in brown adipose tissue but enhanced in subcutaneous WAT of Ucp1-ablated mice. These differences were explainable by expression of the insulin-responsive member 4 of the facilitated glucose transporter family and fully in line with the capacity for NST in these very tissues. Thus, the postprandial glucose uptake of adipose tissues serves as a surrogate measure for Ucp1-dependent and independent capacity for NST. Collectively, our findings corroborate Ucp1 as a modulator of adipose tissue glucose uptake and systemic glucose homeostasis but challenge its hypothesized causal effect on the development of obesity.


Assuntos
Glucose/metabolismo , Homeostase/fisiologia , Termogênese/fisiologia , Proteína Desacopladora 1/metabolismo , Tecido Adiposo Marrom/metabolismo , Animais , Dieta Hiperlipídica , Intolerância à Glucose/metabolismo , Teste de Tolerância a Glucose , Hiperglicemia/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Obesidade/genética , Obesidade/metabolismo , Transcriptoma/genética , Proteína Desacopladora 1/genética
8.
Handb Exp Pharmacol ; 251: 183-214, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30141101

RESUMO

Fatty acids are essential contributors to adipocyte-based non-shivering thermogenesis by acting as activators of uncoupling protein 1 and serving as fuel for mitochondrial heat production. Novel evidence suggests a contribution to this thermogenic mechanism by their conversion to bioactive compounds. Mammalian cells produce a plethora of oxylipins and endocannabinoids, some of which have been identified to affect the abundance or thermogenic activity of brown and brite adipocytes. These effectors are produced locally or at distant sites and signal toward thermogenic adipocytes via a direct interaction with these cells or indirectly via secondary mechanisms. These interactions are evoked by the activation of receptor-mediated pathways. The endogenous production of these compounds is prone to modulation by the dietary intake of the respective precursor fatty acids. The effect of nutritional interventions on uncoupling protein 1-derived thermogenesis may thus at least in part be conferred by the production of a supportive oxylipin and endocannabinoid profile. The manipulation of this system in future studies will help to elucidate the physiological potential of these compounds as novel, endogenous regulators of non-shivering thermogenesis.


Assuntos
Adipócitos , Ácidos Graxos/metabolismo , Mitocôndrias/metabolismo , Termogênese , Proteína Desacopladora 1/metabolismo , Animais , Mitocôndrias/fisiologia , Proteína Desacopladora 1/genética
9.
J Lipid Res ; 59(3): 452-461, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29343538

RESUMO

The recent characterization of functional brown adipose tissue in adult humans has opened new perspectives for regulation of energy expenditure with respect to obesity and diabetes. Furthermore, dietary recommendations have taken into account the insufficient dietary intake of ω3 PUFAs and the concomitant excessive intake of ω6 PUFA associated with the occurrence of overweight/obesity. We aimed to study whether ω3 PUFAs could play a role in the recruitment and function of energy-dissipating brown/brite adipocytes. We show that ω3 PUFA supplementation has a beneficial effect on the thermogenic function of adipocytes. In vivo, a low dietary ω6:ω3 ratio improved the thermogenic response of brown and white adipose tissues to ß3-adrenergic stimulation. This effect was recapitulated in vitro by PUFA treatment of hMADS adipocytes. We pinpointed the ω6-derived eicosanoid prostaglandin (PG)F2α as the molecular origin because the effects were mimicked with a specific PGF2α receptor agonist. PGF2α level in hMADS adipocytes was reduced in response to ω3 PUFA supplementation. The recruitment of thermogenic adipocytes is influenced by the local quantity of individual oxylipins, which is controlled by the ω6:ω3 ratio of available lipids. In human nutrition, energy homeostasis may thus benefit from the implementation of a more balanced dietary ω6:ω3 ratio.


Assuntos
Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Branco/efeitos dos fármacos , Suplementos Nutricionais , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-3/farmacologia , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Células Cultivadas , Humanos , Oxilipinas/metabolismo , Receptores de Prostaglandina/agonistas , Receptores de Prostaglandina/metabolismo
10.
Cancer Immunol Immunother ; 67(6): 935-947, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29556699

RESUMO

The first therapeutic proteasome inhibitor bortezomib has clinical efficacy in mantle cell lymphoma (MCL) which resulted in its incorporation in treatment algorithms for this disease. Impairment of proteasomal function by bortezomib is mediated via inhibition of the 20S core particle. However, proteasome function can also be modified by targeting upstream components of the ubiquitin-proteasome system. Recently, b-AP15 has been identified as a small molecule achieving proteasome inhibition by targeting the deubiquitinase (DUB) activity of the 19S regulatory subunit and was found to inhibit cancer cell growth in preclinical analyses. In the present study, both direct antitumor effects and the possibility to induce natural killer group 2 member D ligands (NKG2DL) to reinforce NK cell immunity with b-AP15 were investigated to provide a rational basis for clinical evaluation of this novel DUB inhibitor in MCL. Treatment with b-AP15 resulted in reduced viability as well as induction of apoptosis in a time- and dose-dependent manner, which could be attributed to caspase activation in MCL cells. In addition, treatment with b-AP15 differentially induced NKG2DL expression and subsequent NK cell lysis of MCL cells. These results indicate that the DUB inhibitor b-AP15 displays substantial antitumor activity in human MCL and suggest that b-AP15 might be a novel therapeutic option in the treatment of MCL that warrants clinical investigation.


Assuntos
Linfoma de Célula do Manto/genética , Piperidonas/uso terapêutico , Proteínas Secretadas Inibidoras de Proteinases/uso terapêutico , Apoptose , Linhagem Celular Tumoral , Humanos , Células Matadoras Naturais/metabolismo , Linfoma de Célula do Manto/metabolismo , Linfoma de Célula do Manto/patologia , Piperidonas/farmacologia , Proteínas Secretadas Inibidoras de Proteinases/farmacologia
11.
Cancer Immunol Immunother ; 67(5): 775-783, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29468363

RESUMO

In chronic myeloid leukemia (CML), the translocation t(9;22) results in the fusion protein BCR-ABL (breakpoint cluster region-abelson murine leukemia), a tyrosine kinase mediating oncogenic signaling which is successfully targeted by treatment with BCR-ABL inhibitors like imatinib. However, BCR-ABL inhibitors may also affect antitumor immunity. For instance, it was reported that imatinib impairs the function of dendritic cells (DCs) that play a central role in initiating and sustaining T cell responses. Meanwhile, second generation BCR-ABL inhibitors like nilotinib, which inhibits BCR-ABL with enhanced potency have become standard of treatment, at least in patients with BCR-ABL kinase domain mutations. In this study we analyzed the influence of therapeutic concentrations of nilotinib on human monocyte-derived DCs and compared its effects to imatinib. We found that both tyrosine kinase inhibitors (TKI) comparably and significantly impaired differentiation of monocytes to DCs as revealed by curtated downregulation of CD14 and reduced upregulation of CD1a and CD83. This was only partially restored after withdrawal of the TKI. Moreover, both TKI significantly reduced activation-induced IL-12p70 and C-C motif chemokine ligand (CCL) 3 secretion, while divergent TKI effects for CCL2 and CCL5 were observed. In contrast, only nilotinib significantly impaired the migratory capacity of DCs and their capacity to induce T-cell immune responses in MLRs. Our results indicate that imatinib and nilotinib may differ significantly with regard to their influence on antitumor immunity. Thus, for future combinatory approaches and particularly stop studies in CML treatment, choice of the most suitable BCR-ABL inhibitor requires careful consideration.


Assuntos
Células Dendríticas/efeitos dos fármacos , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Mesilato de Imatinib/farmacologia , Monócitos/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Células Cultivadas , Células Dendríticas/citologia , Células Dendríticas/imunologia , Humanos , Monócitos/citologia , Monócitos/imunologia , Fenótipo
12.
BMC Neurosci ; 19(1): 40, 2018 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-29996777

RESUMO

BACKGROUND: Visuospatial attention is executed by the frontoparietal cortical areas of the brain. Damage to these areas can result in visual neglect. We therefore aimed to assess a combination of the greyscales task and repetitive navigated transcranial magnetic stimulation (rTMS) to identify cortical regions involved in visuospatial attention processes. This pilot study was designed to evaluate an approach in a cohort of healthy volunteers, with the future aim of using this technique to map brain tumor patients before surgery. Ten healthy, right-handed subjects underwent rTMS mapping of 52 cortical spots in both hemispheres. The greyscales task was presented tachistoscopically and was time-locked to rTMS pulses. The task pictures showed pairs of horizontal rectangles shaded continuously from black at one end to white at the other, mirror-reversed. On each picture the subject was asked to report which of the two greyscales appeared darker overall. The responses were categorized into "leftward" and "rightward," depending on whether the subject had chosen the rectangle with the darker end on the left or the right. rTMS applied to cortical areas involved in visuospatial attention is supposed to affect lateral shifts in spatial bias. These shifts result in an altered performance on the greyscales task compared to the baseline performance without rTMS stimulation. RESULTS: In baseline conditions, 9/10 subjects showed classic pseudoneglect to the left. Leftward effects also occurred more often in mapping conditions. Yet, calculated rightward deviations were strikingly greater in magnitude (p < 0.0001). Overall, the right hemisphere was found to be more suggestible than the left hemisphere. Both rightward and leftward deviation scores were higher for the rTMS of this brain side (p < 0.0001). Right hemispheric distributions accord well with current models of visuospatial attention (Corbetta et al. Nat Neurosci 8(11):1603-1610, 2005). We observed leftward deviations triggered by rTMS within superior frontal and posterior parietal areas and rightward deviations within inferior frontal areas and the temporoparietal junction (TPJ). CONCLUSION: The greyscales task, in combination with rTMS, yields encouraging results in the examination of the visuospatial attention function. Future clinical implications should be evaluated.


Assuntos
Atenção/fisiologia , Mapeamento Encefálico , Desempenho Psicomotor , Estimulação Magnética Transcraniana , Adulto , Encéfalo/fisiologia , Encéfalo/cirurgia , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Transtornos da Percepção/fisiopatologia , Estimulação Luminosa/métodos , Percepção Espacial/fisiologia , Estimulação Magnética Transcraniana/métodos , Percepção Visual/fisiologia , Adulto Jovem
13.
BMC Neurosci ; 17(1): 67, 2016 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-27776478

RESUMO

BACKGROUND: The spatial resolution of repetitive navigated transcranial magnetic stimulation (rTMS) for language mapping is largely unknown. Thus, to determine a minimum spatial resolution of rTMS for language mapping, we evaluated the mapping sessions derived from 19 healthy volunteers for cortical hotspots of no-response errors. Then, the distances between hotspots (stimulation points with a high error rate) and adjacent mapping points (stimulation points with low error rates) were evaluated. RESULTS: Mean distance values of 13.8 ± 6.4 mm (from hotspots to ventral points, range 0.7-30.7 mm), 10.8 ± 4.8 mm (from hotspots to dorsal points, range 2.0-26.5 mm), 16.6 ± 4.8 mm (from hotspots to apical points, range 0.9-27.5 mm), and 13.8 ± 4.3 mm (from hotspots to caudal points, range 2.0-24.2 mm) were measured. CONCLUSIONS: According to the results, the minimum spatial resolution of rTMS should principally allow for the identification of a particular gyrus, and according to the literature, it is in good accordance with the spatial resolution of direct cortical stimulation (DCS). Since measurement was performed between hotspots and adjacent mapping points and not on a finer-grained basis, we only refer to a minimum spatial resolution. Furthermore, refinement of our results within the scope of a prospective study combining rTMS and DCS for resolution measurement during language mapping should be the next step.


Assuntos
Mapeamento Encefálico , Córtex Cerebral/fisiologia , Idioma , Estimulação Magnética Transcraniana , Adulto , Mapeamento Encefálico/métodos , Córtex Cerebral/diagnóstico por imagem , Humanos , Testes de Linguagem , Imageamento por Ressonância Magnética , Testes Neuropsicológicos , Fala/fisiologia , Estimulação Magnética Transcraniana/métodos , Adulto Jovem
14.
Neuroradiology ; 58(8): 807-18, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27079196

RESUMO

INTRODUCTION: Repetitive navigated transcranial magnetic stimulation (rTMS) can be used for preoperative language mapping, but it still suffers from comparatively high sensitivity and low specificity when compared to direct cortical stimulation (DCS). Therefore, this study evaluates whether the additional consideration of rTMS-based diffusion tensor imaging fiber tracking (DTI FT) for identifying language-positive brain regions improves specificity when compared to DCS. METHODS: We performed rTMS, rTMS-based DTI FT, and DCS during awake surgery combined with object naming in 20 patients suffering from left-sided perisylvian brain lesions. For rTMS, different error rate thresholds (ERTs) and error types were considered, and DTI FT was conducted with individualized fractional anisotropy thresholds (FATs). Then, receiver operating characteristics (ROC) for rTMS vs. DCS, rTMS-based DTI FT vs. DCS, and rTMS spots confirmed by rTMS-based DTI FT vs. DCS were calculated. RESULTS: In general, rTMS vs. DCS was in good accordance with previous literature (sensitivity/specificity: 92.7/13.3 % for all naming errors without ERT). In addition, rTMS-based DTI FT vs. DCS led to balanced results when tracking was based on all errors as well (sensitivity/specificity: 62.8/64.3 % for 100 % FAT). However, rTMS combined with rTMS-based DTI FT vs. DCS did not lead to any improvement in specificity when compared to rTMS vs. DCS alone. CONCLUSION: The additional use of rTMS-based DTI FT to rTMS did not improve the identification of DCS-positive language areas during awake surgery. Yet, concerning rTMS-based DTI FT, this new technique must be validated itself by intraoperative subcortical stimulation.


Assuntos
Mapeamento Encefálico/métodos , Neoplasias Encefálicas/patologia , Encéfalo/patologia , Encéfalo/fisiopatologia , Monitorização Neurofisiológica Intraoperatória/métodos , Idioma , Estimulação Magnética Transcraniana/métodos , Adulto , Encéfalo/cirurgia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/cirurgia , Criança , Imagem de Tensor de Difusão/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Rede Nervosa/patologia , Rede Nervosa/fisiopatologia , Cuidados Pré-Operatórios/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
15.
Neuroimage ; 116: 80-91, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-25979668

RESUMO

The mental practice of movements has been suggested as a promising add-on therapy to facilitate motor recovery after stroke. In the case of mentally practised movements, electroencephalogram (EEG) can be utilized to provide feedback about an otherwise covert act. The main target group for such an intervention are elderly patients, though research so far is largely focused on young populations (<30 years). The present study therefore aimed to examine the influence of age on the neural correlates of covert movements (CMs) in a real-time EEG neurofeedback framework. CM-induced event-related desynchronization (ERD) was studied in young (mean age: 23.6 years) and elderly (mean age: 62.7 years) healthy adults. Participants performed covert and overt hand movements. CMs were based on kinesthetic motor imagery (MI) or quasi-movements (QM). Based on previous studies investigating QM in the mu frequency range (8-13Hz) QM were expected to result in more lateralized ERD% patterns and accordingly higher classification accuracies. Independent of CM strategy the elderly were characterized by a significantly reduced lateralization of ERD%, due to stronger ipsilateral ERD%, and in consequence, reduced classification accuracies. QM were generally perceived as more vivid, but no differences were evident between MI and QM in ERD% or classification accuracies. EEG feedback enhanced task-related activity independently of strategy and age. ERD% measures of overt and covert movements were strongly related in young adults, whereas in the elderly ERD% lateralization is dissociated. In summary, we did not find evidence in support of more pronounced ERD% lateralization patterns in QM. Our finding of a less lateralized activation pattern in the elderly is in accordance to previous research and with the idea that compensatory processes help to overcome neurodegenerative changes related to normal ageing. Importantly, it indicates that EEG neurofeedback studies should place more emphasis on the age of the potential end-users.


Assuntos
Córtex Cerebral/fisiologia , Lateralidade Funcional/fisiologia , Imaginação/fisiologia , Movimento , Neurorretroalimentação , Adulto , Fatores Etários , Ondas Encefálicas , Eletroencefalografia/métodos , Feminino , Mãos , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
16.
BMC Neurosci ; 16: 5, 2015 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-25880838

RESUMO

BACKGROUND: Although language mapping by repetitive navigated transcranial magnetic stimulation (rTMS) gains importance in neuropsychological research and clinical utility, neuroscientists still use different mapping protocols including different stimulation frequencies. To refine the existing language protocol, we tested two different repetition rates of 5 Hz/10 pulses and 7 Hz/10 pulses with a 0 ms delay in 19 healthy subjects. We furthermore investigated differences between both frequencies in case of performance of four different language tasks: object naming, pseudoword reading, verb generation, and action naming. RESULTS: Even the small variance in frequencies revealed statistically significant differences concerning the number and type of language errors. Stimulation with 5 Hz evoked a higher number of all occurred language errors in all language tasks (error rate object naming 14% (5 Hz) vs. 12% (7 Hz); pseudoword reading 4% (5 Hz) vs. 3% (7 Hz); verb generation 13% (5 Hz) vs. 11% (7 Hz); action naming 11% (5 Hz) vs. 9% (7 Hz)), whereas 7 Hz evoked specifically more total speech arrests. CONCLUSION: These findings suggest that the stimulation frequency has to be adapted to the aim of the rTMS language investigation.


Assuntos
Córtex Cerebral/fisiologia , Idioma , Fala/fisiologia , Estimulação Magnética Transcraniana/métodos , Adulto , Mapeamento Encefálico/métodos , Feminino , Humanos , Testes de Linguagem , Masculino , Estimulação Luminosa , Fatores de Tempo , Percepção Visual/fisiologia , Adulto Jovem
17.
BMC Cancer ; 15: 261, 2015 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-25885761

RESUMO

BACKGROUND: Language mapping by repetitive navigated transcranial magnetic stimulation (rTMS) is used for resection planning in patients suffering from brain lesions within regions known to be involved in language function. Yet we also need data that show whether patients benefit clinically from preoperative rTMS for language mapping. METHODS: We enrolled 25 patients with language eloquently located brain lesions undergoing preoperative rTMS language mapping (GROUP 1, 2011-2013), with the mapping results not being available for the surgeon, and we matched these patients with 25 subjects who also underwent preoperative rTMS (GROUP 2, 2013-2014), but the mapping results were taken into account during tumor resection. Additionally, cortical language maps were generated by analyzing preoperative rTMS and intraoperative direct cortical stimulation (DCS) data. RESULTS: Mean anterior-posterior (ap) craniotomy extents and overall craniotomy sizes were significantly smaller for the patients in GROUP 2 (Ap: p = 0.0117; overall size: p = 0.0373), and postoperative language deficits were found significantly more frequently for the patients in GROUP 1 (p = 0.0153), although the preoperative language status did not differ between groups (p = 0.7576). Additionally, there was a trend towards fewer unexpected tumor residuals, shorter surgery duration, less peri- or postoperative complications, shorter inpatient stay, and higher postoperative Karnofsky performance status scale (KPS) for the patients in GROUP 2. CONCLUSIONS: The present study provides a first hint that the clinical course of patients suffering from brain tumors might be improved by preoperative rTMS language mapping. However, a significant difference between both groups was only found for craniotomy extents and postoperative deficits, but not for other clinical parameters, which only showed a trend toward better results in GROUP 2. Therefore, multicenter trials with higher sample sizes are needed to further investigate the distinct impact of rTMS language mapping on the clinical course of brain tumor patients.


Assuntos
Mapeamento Encefálico , Neoplasias Encefálicas/cirurgia , Patologia da Fala e Linguagem , Estimulação Magnética Transcraniana/métodos , Adulto , Neoplasias Encefálicas/fisiopatologia , Córtex Cerebral/fisiopatologia , Craniotomia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias
18.
J Neurol Surg A Cent Eur Neurosurg ; 85(3): 269-273, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-36914157

RESUMO

BACKGROUND: There has been a fivefold increase of neurosurgeons over the last three decades in Germany, despite a lesser increase in operations. Currently, there are approximately 1,000 neurosurgical residents employed at training hospitals. Little is known about the overall training experience and career opportunities for these trainees. METHODS: In our role as resident representatives, we implemented a mailing list for interested German neurosurgical trainees. Thereafter, we created a survey including 25 items to assess the trainees' satisfaction with their training and their perceived career prospects, which we then distributed through the mailing list. The survey was open from April 1 until May 31 2021. RESULTS: Ninety trainees were enrolled in the mailing list and we received 81 completed responses to our survey. Overall, 47% of the trainees were very dissatisfied or dissatisfied with their training. Sixty-two percent of the trainees reported a lack of surgical training. Fifty-eight percent of trainees found it difficult to attend courses or classes and only 16% had consistent mentoring. There was an expressed desire for a more structured training program and mentoring projects. In addition, 88% of trainees were willing to relocate for fellowships outside their current hospitals. CONCLUSIONS: Half of the responders were dissatisfied with their neurosurgical training. There are various aspects that require improvement, such as the training curriculum, structured mentoring, and reduction of the amount of administrative work. We propose the implementation of a modernized structured curriculum, which addresses the mentioned aspects, in order to improve neurosurgical training and, consecutively, patient care.


Assuntos
Internato e Residência , Humanos , Inquéritos e Questionários , Currículo , Alemanha
19.
J Immunother Cancer ; 10(2)2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35110356

RESUMO

T cell-based immunotherapy, for example, with T cell-recruiting bispecific antibody (bsAb), has revolutionized oncological treatment. However, many patients do not respond to treatment, and long-term remissions are still rare. Several tumor immune evasion mechanisms have been reported to counteract efficiency of T cell-engaging therapeutics. Platelets largely affect cancer pathophysiology by mediating tumor invasion, metastasis, and immune evasion. On treatment of patients in a clinical trial with a PSMA×CD3 bsAb (NCT04104607), we observed profound treatment-associated platelet activation, mirrored by a decrease of total platelet count. On modeling the treatment setting, we found that platelet activation significantly reduced bsAb-mediated CD4+ and CD8+ T-cell reactivity as revealed by impaired T-cell degranulation, secretion of perforin, and ultimately, inhibition of target cell lysis. This effect occurred in a transforming growth factor beta (TGF-ß)-dependent manner and was not restricted to PSMA×CD3 bsAb, but rather observed with various CD3-directed bispecific constructs, including the approved CD19×CD3 bsAb blinatumomab. BsAb-mediated T-cell reactivity could be restored by platelet inhibition and specifically by blocking the TGF-ß axis. Together, our findings demonstrate that platelets undermine the efficacy of T cell-recruiting bsAb and identify modulation of platelet function as a means to reinforce the effectiveness of bsAb treatment.


Assuntos
Anticorpos Biespecíficos/metabolismo , Plaquetas/metabolismo , Inibidores de Checkpoint Imunológico/uso terapêutico , Linfócitos T/metabolismo , Idoso , Feminino , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Masculino
20.
J Neurosurg ; 136(4): 1141-1146, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-34507274

RESUMO

OBJECTIVE: Despite the rising number of women in higher education and leadership positions, the proportional rise of female neurosurgeons still lags behind these fields. This study evaluates the gender distribution in German neurosurgical departments across all career levels, and is aimed at heightening the awareness of gender disparity and the need for improving gender equality and its related opportunities. METHODS: Data on gender distribution across all professional levels in German neurosurgical departments were obtained from departmental websites as well as by email and telephone request. Results were additionally analyzed in reference to hospital ownership type of the neurosurgical departments. RESULTS: A total of 140 German neurosurgical departments employing 2324 neurosurgeons were evaluated. The analysis revealed a clear preponderance of men in leadership positions. Only 9 (6.3%) of 143 department heads were women, and there were only 1 (2.4%), 17 (14.5%), and 4 (12.5%) women among 42 vice-directors, 117 chief senior physicians, and 32 managing senior physicians, respectively. Senior physicians not holding a leadership position were female in 23.1%, whereas board-certified neurosurgeons not holding a senior physician position and residents were female in 33.6% and 35.0%, respectively. Of note, the highest proportion of female department heads (15.6%) was found in private hospitals. CONCLUSIONS: The number of women in leadership positions in German neurosurgical departments is dramatically low, and with increasing leadership status gender disparity increases. Mentorship, recruitment, the perception of benefits offered by diversity and programs facilitating gender equality, job sharing, parental leave policies, and onsite childcare programs are needed to turn German neurosurgical departments into modern medical departments reflecting the gender profile of the general patient population.


Assuntos
Neurocirurgia , Médicas , Feminino , Humanos , Liderança , Masculino , Neurocirurgiões , Neurocirurgia/educação , Procedimentos Neurocirúrgicos
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