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1.
J Neurosci ; 42(8): 1587-1603, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-34987109

RESUMO

Astrocytes are critical for the development and function of synapses. There are notable species differences between human astrocytes and commonly used animal models. Yet, it is unclear whether astrocytic genes involved in synaptic function are stable or exhibit dynamic changes associated with disease states and age in humans, which is a barrier in understanding human astrocyte biology and its potential involvement in neurologic diseases. To better understand the properties of human astrocytes, we acutely purified astrocytes from the cerebral cortices of over 40 humans across various ages, sexes, and disease states. We performed RNA sequencing to generate transcriptomic profiles of these astrocytes and identified genes associated with these biological variables. We found that human astrocytes in tumor-surrounding regions downregulate genes involved in synaptic function and sensing of signals in the microenvironment, suggesting involvement of peritumor astrocytes in tumor-associated neural circuit dysfunction. In aging, we also found downregulation of synaptic regulators and upregulation of markers of cytokine signaling, while in maturation we identified changes in ionic transport with implications for calcium signaling. In addition, we identified subtle sexual dimorphism in human cortical astrocytes, which has implications for observed sex differences across many neurologic disorders. Overall, genes involved in synaptic function exhibit dynamic changes in the peritumor microenvironment and aging. These data provide powerful new insights into human astrocyte biology in several biologically relevant states that will aid in generating novel testable hypotheses about homeostatic and reactive astrocytes in humans.SIGNIFICANCE STATEMENT Astrocytes are an abundant class of cells playing integral roles at synapses. Astrocyte dysfunction is implicated in a variety of human neurologic diseases. Yet our knowledge of astrocytes is largely based on mouse studies. Direct knowledge of human astrocyte biology remains limited. Here, we present transcriptomic profiles of human cortical astrocytes, and we identified molecular differences associated with age, sex, and disease state. We found that peritumor and aging astrocytes downregulate genes involved in astrocyte-synapse interactions. These data provide necessary insight into human astrocyte biology that will improve our understanding of human disease.


Assuntos
Astrócitos , Transcriptoma , Envelhecimento/patologia , Animais , Astrócitos/fisiologia , Feminino , Humanos , Masculino , Camundongos , Sinapses/fisiologia , Microambiente Tumoral
2.
J Neurooncol ; 163(2): 417-427, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37294422

RESUMO

PURPOSE: There is limited knowledge about the associations between sodium and proton MRI measurements in brain tumors. The purpose of this study was to quantify intra- and intertumoral correlations between sodium, diffusion, and perfusion MRI in human gliomas. METHODS: Twenty glioma patients were prospectively studied on a 3T MRI system with multinuclear capabilities. Three mutually exclusive tumor volumes of interest (VOIs) were segmented: contrast-enhancing tumor (CET), T2/FLAIR hyperintense non-enhancing tumor (NET), and necrosis. Median and voxel-wise associations between apparent diffusion coefficient (ADC), normalized relative cerebral blood volume (nrCBV), and normalized sodium measurements were quantified for each VOI. RESULTS: Both relative sodium concentration and ADC were significantly higher in areas of necrosis compared to NET (P = 0.003 and P = 0.008, respectively) and CET (P = 0.02 and P = 0.02). Sodium concentration was higher in CET compared to NET (P = 0.04). Sodium and ADC were higher in treated compared to treatment-naïve gliomas within NET (P = 0.006 and P = 0.01, respectively), and ADC was elevated in CET (P = 0.03). Median ADC and sodium concentration were positively correlated across patients in NET (r = 0.77, P < 0.0001) and CET (r = 0.84, P < 0.0001), but not in areas of necrosis (r = 0.45, P = 0.12). Median nrCBV and sodium concentration were negatively correlated across patients in areas of NET (r=-0.63, P = 0.003). Similar associations were observed when examining voxel-wise correlations within VOIs. CONCLUSION: Sodium MRI is positively correlated with proton diffusion MRI measurements in gliomas, likely reflecting extracellular water. Unique areas of multinuclear MRI contrast may be useful in future studies to understand the chemistry of the tumor microenvironment.


Assuntos
Neoplasias Encefálicas , Glioma , Humanos , Prótons , Imageamento por Ressonância Magnética , Glioma/diagnóstico por imagem , Glioma/patologia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Imagem de Difusão por Ressonância Magnética , Perfusão , Necrose , Microambiente Tumoral
3.
Endocr Pract ; 26(1): 16-21, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31461359

RESUMO

Objective: Acromegaly results from the excessive production of growth hormone and insulin-like growth factor-1. While there is up to a 2-fold increased prevalence of thyroid nodules in patients with acromegaly, the incidence of thyroid cancer in this population varies from 1.6 to 10.6% in several European studies. The goal of our study was to determine the prevalence of thyroid nodules and thyroid cancer among patients with acromegaly at a large urban academic medical center in the United States (U.S.). Methods: A retrospective chart review was performed of all patients with acromegaly between 2006-2015 within the University of California, Los Angeles health system. Data were collected regarding patient demographics, thyroid ultrasounds, thyroid nodule fine needle aspiration (FNA) biopsy cytology, and thyroid surgical pathology. Results: In this cohort (n = 221, 49.3% women, mean age 53.8 ± 15.2 [SD] years, 55.2% Caucasian), 102 patients (46.2%) underwent a thyroid ultrasound, from which 71 patients (52.1% women, mean age 52.9 ± 15.2 [SD] years, 56.3% Caucasian) were found to have a thyroid nodule. Seventeen patients underwent a thyroid nodule FNA biopsy and the results revealed 12 benign biopsies, 1 follicular neoplasm, 3 suspicious for malignancy, and 1 papillary thyroid cancer (PTC), from which 6 underwent thyroidectomy; PTC was confirmed by surgical pathology for all cases (8.5% of all nodules observed). Conclusion: In this sample, the prevalence of thyroid cancer in patients with acromegaly and coexisting thyroid nodules is similar to that reported in the general U.S. population with thyroid nodules (7 to 15%). These findings suggest that there is no benefit of dedicated thyroid nodule screening in patients newly diagnosed with acromegaly. Abbreviations: AACE = American Association of Clinical Endocrinologists; ATA = American Thyroid Association; DTC = differentiated thyroid cancer; FNA = fine needle aspiration; GH = growth hormone; IGF-1 = insulin-like growth factor-1; PTC = papillary thyroid cancer; U.S. = United States.


Assuntos
Acromegalia , Neoplasias da Glândula Tireoide , Nódulo da Glândula Tireoide , Adulto , Idoso , Biópsia por Agulha Fina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
4.
J Neurooncol ; 138(3): 557-569, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29525972

RESUMO

A novel glucose transporter, the sodium glucose cotransporter 2 (SGLT2), has been demonstrated to contribute to the demand for glucose by pancreatic and prostate tumors, and its functional activity has been imaged using a SGLT specific PET imaging probe, α-methyl-4-[F-18]fluoro-4-deoxy-D-glucopyaranoside (Me-4FDG). In this study, Me-4FDG PET was extended to evaluate patients with high-grade astrocytic tumors. Me-4FDG PET scans were performed in four patients diagnosed with WHO Grade III or IV astrocytomas and control subjects, and compared with 2-deoxy-2-[F-18]fluoro-D-glucose (2-FDG) PET and magnetic resonance imaging (MRI) of the same subjects. Immunocytochemistry was carried out on Grade IV astrocytomas to determine the cellular location of SGLT proteins within the tumors. Me-4FDG retention was pronounced in astrocytomas in dramatic contrast to the lack of uptake into the normal brain, resulting in a high signal-to-noise ratio. Macroscopically, the distribution of Me-4FDG within the tumors overlapped with that of 2-FDG uptake and tumor definition using contrast-enhanced MRI images. Microscopically, the SGLT2 protein was found to be expressed in neoplastic glioblastoma cells and endothelial cells of the proliferating microvasculature. This preliminary study shows that Me-4FDG is a highly sensitive probe for visualization of high-grade astrocytomas by PET. The distribution of Me-4FDG within tumors overlapped that for 2-FDG, but the absence of background brain Me-4FDG resulted in superior imaging sensitivity. Furthermore, the presence of SGLT2 protein in astrocytoma cells and the proliferating microvasculature may offer a novel therapy using the SGLT2 inhibitors already approved by the FDA to treat type 2 diabetes mellitus.


Assuntos
Astrocitoma/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico por imagem , Glucosídeos , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Transportador 2 de Glucose-Sódio/metabolismo , Adulto , Idoso , Astrocitoma/metabolismo , Astrocitoma/patologia , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Encéfalo/patologia , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Feminino , Humanos , Imuno-Histoquímica , Imageamento por Ressonância Magnética , Masculino , Microvasos/metabolismo , Microvasos/patologia , Pessoa de Meia-Idade , Gradação de Tumores , Dados Preliminares
5.
Pituitary ; 21(3): 290-301, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29404894

RESUMO

PURPOSE: Pituitary tumors are the second most common intracranial tumors, however, pituitary carcinoma is a rare clinical entity which represents only 0.1-0.2% of all pituitary tumors. Diagnosis of pituitary carcinoma requires the presence of metastasis. Early identification of pituitary carcinoma is difficult, and only recently have guidelines been published for the treatment of aggressive pituitary tumors. We present two cases from our institution, with a review of other cases available in literature in order to better characterize this rare disease. METHODS: A retrospective review of two patients with pituitary carcinoma treated at a tertiary medical center was performed. The MEDLINE database was searched for all cases of pituitary carcinoma. Information for age at diagnosis, sex, pituitary tumor type, latency period from pituitary tumor to presentation of carcinoma, sites of metastasis, number of surgical therapies, radiation and chemotherapy, and survival after diagnosis were collected. RESULTS: A total of 69 studies were available for review for a total of 72 unique cases. The average age at diagnosis was 46.3 years. The most common tumors were ACTH-secreting (34.7%), Prolactin-secreting (23.6%), and Null Cell (15.3%). The average latency period from pituitary tumor diagnosis to metastasis was 9 years. All patients underwent surgical therapy during their treatment, with an average of 2.76 procedures. The mortality rate was 54.8% with average time to death after diagnosis of approximately 10 months. CONCLUSIONS: Pituitary carcinoma is a rare disease with high mortality rate and is a diagnostic and treatment challenge. Further study is required but is difficult due to its low incidence.


Assuntos
Carcinoma/complicações , Neoplasias Hipofisárias/complicações , Neoplasias do Colo do Útero/secundário , Carcinoma/patologia , Feminino , Humanos , Neoplasias Hipofisárias/patologia , Estudos Retrospectivos , Neoplasias do Colo do Útero/patologia
6.
Neuropathology ; 38(1): 54-61, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28833600

RESUMO

Only two prior cases of benign dendritic melanocytes colonizing a meningioma have been reported. We add a third case, describe clinicopathologic features shared by the three, and elucidate the risk factors for this very rare phenomenon. A 29 year-old Hispanic woman presented with headache and hydrocephalus. MRI showed a lobulated enhancing pineal region mass measuring 41 mm in greatest dimension. Subtotal resection of the mass demonstrated an atypical meningioma, WHO grade II, and the patient subsequently underwent radiotherapy. She presented 4 years later with diplopia, and MRI showed an enhancing extra-axial mass measuring 47 mm in greatest dimension and centered on the tentorial incisura. Subtotal resection showed a brain-invasive atypical meningioma with melanocytic colonization. The previous two cases in the literature were atypical meningiomas, one of which was also brain invasive. Atypical meningiomas may be at particular risk for melanocytic colonization as they upregulate molecules known to be chemoattractants for melanocytes. We detected c-Kit expression in a minority of the melanocytes as well as stem cell factor and basic fibroblast growth factor in the meningioma cells, suggesting that mechanisms implicated in normal melanocyte migration may be involved. In some cases, brain invasion with disruption of the leptomeningeal barrier may also facilitate migration from the subarachnoid space into the tumor. Whether there is low-level proliferation of the dendritic melanocytes is unclear. Given that all three patients were non-Caucasian, meningiomas in persons and/or brain regions with increased dendritic melanocytes may predispose to colonization. The age range spanned from 6 years old to 70 years old. All three patients were female. The role of gender and estrogen in the pathogenesis of this entity remains to be clarified. Whether melanocytic colonization may also occur in the more common Grade I meningiomas awaits identification of additional cases.


Assuntos
Melanócitos/patologia , Neoplasias Meníngeas/patologia , Meningioma/patologia , Adulto , Feminino , Humanos
7.
J Neurooncol ; 132(2): 351-358, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28161760

RESUMO

Latino Americans are a rapidly growing ethnic group in the United States but studies of glioblastoma in this population are limited. We have evaluated characteristics of 21,184 glioblastoma patients from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute. This SEER data from 2001 to 2011 draws from 28% of the U.S. POPULATION: Latinos have a lower incidence of GBM and present slightly younger than non-Latino Whites. Cubans present at an older age than other Latino sub-populations. Latinos have a higher incidence of giant cell glioblastoma than non-Latino Whites while the incidence of gliosarcoma is similar. Despite lower rates of radiation therapy and greater rates of sub-total resection than non-Latino Whites, Latinos have better 1 and 5 year survival rates. SEER does not record chemotherapy data. Survivals of Latino sub-populations are similar with each other. Age, extent of resection, and the use of radiation therapy are associated with improved survival but none of these variables are sufficient in a multivariate analysis to explain the improved survival of Latinos relative to non-Latino Whites. As molecular data is not available in SEER records, we studied the MGMT and IDH status of 571 patients from a UCLA database. MGMT methylation and IDH1 mutation rates are not statistically significantly different between non-Latino Whites and Latinos. For UCLA patients with available information, chemotherapy and radiation rates are similar for non-Latino White and Latino patients, but the latter have lower rates of gross total resection and present at a younger age.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Adulto , Idoso , Neoplasias Encefálicas/epidemiologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Estudos de Coortes , Metilases de Modificação do DNA/genética , Metilases de Modificação do DNA/metabolismo , Enzimas Reparadoras do DNA/genética , Enzimas Reparadoras do DNA/metabolismo , Conjuntos de Dados como Assunto/estatística & dados numéricos , Feminino , Glioblastoma/epidemiologia , Glioblastoma/genética , Glioblastoma/mortalidade , Glioblastoma/patologia , Hispânico ou Latino , Humanos , Incidência , Isocitrato Desidrogenase/genética , Masculino , Pessoa de Meia-Idade , Mutação/genética , Análise de Sobrevida , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Estados Unidos/epidemiologia
8.
Acta Neurochir (Wien) ; 159(11): 2193-2207, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28913667

RESUMO

PURPOSE: The aim of this systematic review is to evaluate the long-term endocrine outcomes and postoperative complications following endoscopic vs. microscopic transsphenoidal resection (TSR) for the treatment of acromegaly. METHODS: A literature review was performed, and studies with at least five patients who underwent TSR for acromegaly, reporting biochemical remission criteria and long-term remission outcomes were included. Data extracted from each study included surgical technique, perioperative complications, biochemical remission criteria, and long-term remission outcomes. RESULTS: Fifty-two case series from 1976 to 2016 met the inclusion criteria, comprising 4375 patients. Thirty-six reports were microsurgical (n = 3144) and 13 were endoscopic (n = 940). Three studies compared microsurgical (n = 111) to endoscopic TSR outcomes (n = 180). The overall initial and long-term remission rates were 58.2 vs. 57.4% and 69.2 vs. 70.2% for the microsurgical and endoscopic groups, respectively. For microadenomas, the initial and long-term remission rates were 77.6 vs. 82.2% and 76.9 vs. 73.5% for microsurgical and endoscopic approaches, respectively. For macroadenomas, the initial and long-term remission rates were 46.9 vs. 60.0% and 40.2 vs. 61.5% for microsurgical and endoscopic approaches, respectively. The rates of postoperative CSF leak were 3.0 vs. 2.3% for the microscopic and endoscopic groups, respectively. The rates of hypopituitarism and transient diabetes insipidus were 6.7 vs. 6.4% and 9.0 vs. 7.8% for the microscopic and endoscopic groups, respectively. CONCLUSIONS: Both endoscopic and microsurgical approaches for TSR of growth hormone-secreting adenomas are viable treatment options for patients with acromegaly, and yield similarly high rates of remission under the most current consensus criteria.


Assuntos
Acromegalia/cirurgia , Endoscopia/métodos , Adenoma Hipofisário Secretor de Hormônio do Crescimento/cirurgia , Microcirurgia/métodos , Neoplasias Hipofisárias/cirurgia , Vazamento de Líquido Cefalorraquidiano/epidemiologia , Humanos , Hipopituitarismo , Complicações Pós-Operatórias , Osso Esfenoide/cirurgia , Resultado do Tratamento
9.
Acta Neurochir Suppl ; 122: 339-45, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27165933

RESUMO

INTRODUCTION: The diversion of cerebrospinal fluid (CSF) remains the principal treatment option for patients with normal-pressure hydrocephalus (NPH). External lumbar drain (ELD) and overnight intracranial pressure (ICP) monitoring are popular prognostic tests for differentiating which patients will benefit from shunting. Using the morphological clustering and analysis of continuous intracranial pulse (MOCAIP) algorithm to extract morphological metrics from the overnight ICP signal, we hypothesize that changes in the third peak of the ICP pulse pressure waveform can be used to differentiate ELD responders and nonresponders. MATERIALS AND METHODS: Our study involved 66 patients (72.2 ± 9.8 years) undergoing evaluation for possible NPH, which included overnight ICP monitoring and ELD. ELD outcome was based on clinical notes and divided into nonresponders and responders. MOCAIP was used to extract mean ICP, ICP wave amplitude (waveAmp), and a metric derived to study P3 elevation (P3ratio). RESULTS: Of the 66 patients, 7 were classified as nonresponders and 25 as significant responders. The mean ICP and waveAmp did not vary significantly (p = 0.19 and p = 0.41) between the outcome groups; however, the P3ratio did show a significant difference (p = 0.04). CONCLUSION: Initial results suggest that the P3ratio might be used as a prognostic indicator for ELD outcome.


Assuntos
Derivações do Líquido Cefalorraquidiano , Hidrocefalia de Pressão Normal/cirurgia , Pressão Intracraniana/fisiologia , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Cloridrato de Bendamustina , Feminino , Humanos , Hidrocefalia de Pressão Normal/fisiopatologia , Masculino , Pessoa de Meia-Idade , Análise de Onda de Pulso , Estudos Retrospectivos
10.
Proc Natl Acad Sci U S A ; 110(21): 8555-60, 2013 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-23653479

RESUMO

Cushing disease (CD) is a life-threatening disorder attributed to excess pituitary tumor-derived adrenocorticotrophic hormone (ACTH) and adrenal steroid secretion caused by pituitary tumors. Whereas CD was first described in 1932, the underlying genetic basis driving tumor growth and ACTH secretion remains unsolved. Here, we show that testicular orphan nuclear receptor 4 (TR4, nuclear receptor subfamily 2, group C, member 2) is overexpressed in human corticotroph tumors as well as in human and mouse corticotroph tumor cell lines. Forced overexpression of TR4 in both human and murine tumor cells increased proopiomelanocortin transcription, ACTH secretion, cellular proliferation, and tumor invasion rates in vitro. Conversely, knockdown of TR4 expression reversed all phenotypes. Mechanistically, we show that TR4 transcriptionally activates proopiomelanocortin through binding of a direct repeat 1 response element in the promoter, and that this is enhanced by MAPK-mediated TR4 phosphorylation. In vivo, TR4 overexpression promotes murine corticotroph tumor growth as well as enhances ACTH and corticosterone production, whereas TR4 knockdown decreases circulating ACTH and corticosterone levels in mice harboring ACTH-secreting tumors. Our findings directly link TR4 to the etiology of corticotroph tumors, hormone secretion, and cell growth as well as identify it as a potential target in the treatment of CD.


Assuntos
Adenoma Hipofisário Secretor de ACT/metabolismo , Hormônio Adrenocorticotrópico/metabolismo , Proteínas de Neoplasias/metabolismo , Hipersecreção Hipofisária de ACTH/metabolismo , Receptores de Esteroides/metabolismo , Receptores dos Hormônios Tireóideos/metabolismo , Adenoma Hipofisário Secretor de ACT/genética , Adenoma Hipofisário Secretor de ACT/patologia , Adenoma Hipofisário Secretor de ACT/terapia , Hormônio Adrenocorticotrópico/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células , Corticosterona/genética , Corticosterona/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Camundongos , Proteínas de Neoplasias/genética , Hipersecreção Hipofisária de ACTH/genética , Hipersecreção Hipofisária de ACTH/patologia , Hipersecreção Hipofisária de ACTH/terapia , Pró-Opiomelanocortina/biossíntese , Pró-Opiomelanocortina/genética , Receptores de Esteroides/genética , Receptores dos Hormônios Tireóideos/genética , Elementos de Resposta/genética , Ativação Transcricional/genética
11.
Am J Otolaryngol ; 36(4): 521-5, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25794787

RESUMO

OBJECTIVES: Acromegalics present with a wide range of otolaryngic symptoms, including rhinosinusitis, changes in facial appearance, obstructive sleep apnea (OSA), and voice disturbances. Treatment typically involves transnasal-transsphenoidal (TNTS) resection of the offending pituitary adenoma. In this study, we identify the prevalence of otolaryngic symptoms of acromegalic patients, and evaluate Sinonasal Outcome Test (SNOT-22) scores preceding and following pituitary resection. DESIGN: Retrospective chart review. SETTING: Tertiary academic medical center. PARTICIPANTS: Patients diagnosed with acromegaly who underwent surgical resection of a growth-hormone secreting pituitary adenoma between August 2010 and September 2013. MAIN OUTCOME MEASURES: Subjects were asked to complete questionnaires detailing otolaryngic symptoms as well as SNOT-22 surveys before and after TNTS surgery. A Student's t-test was used to compare preoperative and postoperative SNOT-22 scores. RESULTS: Twenty-five patients underwent pituitary surgery for acromegaly. Acromegalic patients were found to have macroglossia (60%), OSA or sleep-disordered breathing (52%), thyroid neoplasia (20%), hearing loss/tinnitus (20%), sinonasal symptoms (16%), and parathyroid pathology (8%). Differences in preoperative and postoperative SNOT-22 scores were not statistically significant. CONCLUSION: Acromegalics present with assorted otolaryngic complaints. Routine screening of all acromegalics with sleep evaluations (for both surgical and perioperative planning), thyroid ultrasound, and audiologic testing should be strongly considered.


Assuntos
Acromegalia/complicações , Adenoma/diagnóstico , Adenoma Hipofisário Secretor de Hormônio do Crescimento/diagnóstico , Procedimentos Neurocirúrgicos/efeitos adversos , Otorrinolaringopatias/etiologia , Acromegalia/diagnóstico , Adenoma/complicações , Adenoma/cirurgia , Adolescente , Adulto , Idoso , Feminino , Adenoma Hipofisário Secretor de Hormônio do Crescimento/complicações , Adenoma Hipofisário Secretor de Hormônio do Crescimento/cirurgia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Cirurgia Endoscópica por Orifício Natural/efeitos adversos , Cirurgia Endoscópica por Orifício Natural/métodos , Otorrinolaringopatias/diagnóstico , Estudos Retrospectivos , Adulto Jovem
12.
Biomed Microdevices ; 16(1): 153-61, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24077662

RESUMO

The mechanical robustness of microfabricated torsional magnetic actuators in withstanding the strong static fields (7 T) and time-varying field gradients (17 T/m) produced by an MR system was studied in this investigation. The static and dynamic mechanical characteristics of 30 devices were quantitatively measured before and after exposure to both strong uniform and non-uniform magnetic fields. The results showed no statistically significant change in both the static and dynamic mechanical performance, which mitigate concerns about the mechanical stability of these devices in association with MR systems under the conditions used for this assessment. The MR-induced heating was also measured in a 3-T/128-MHz MR system. The results showed a minimal increase (1.6 °C) in temperature due to the presence of the magnetic microactuator array. Finally, the size of the MR-image artifacts created by the magnetic microdevices were quantified. The signal loss caused by the devices was approximately four times greater than the size of the device.


Assuntos
Imageamento por Ressonância Magnética/métodos , Microtecnologia/instrumentação , Próteses e Implantes , Artefatos , Desenho de Equipamento , Campos Magnéticos , Magnetismo/instrumentação
13.
J Neurooncol ; 117(3): 437-44, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24264534

RESUMO

Approximately 5,000 trans-sphenoidal surgeries are performed for resection of pituitary tumors each year in the United States. The rise in popularity of the trans-spehnoidal approach, though described nearly a century ago, has been facilitated over the last decades by advances in technique and technology. In this review, we discuss the relative strengths of microscopic and endoscopic techniques for pituitary tumor resection. However, despite being the standard of care for patients with most pituitary tumors, cure rates for many subtypes of pituitary lesions, such as secretory macroadenomas or tumors with significant cavernous sinus invasion, remain unsatisfactory. We also describe two more recent advances in neurosurgical technique which may offer promise of increased rates of surgical cure: pseudocapsular resection and cavernous sinus approaches.


Assuntos
Procedimentos Neurocirúrgicos/métodos , Neoplasias Hipofisárias/cirurgia , Humanos , Procedimentos Neurocirúrgicos/tendências
14.
J Neurooncol ; 117(3): 477-84, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24549751

RESUMO

Most patients with large pituitary tumors do not exhibit hyperprolactinemia as a result of pituitary lactotroph disinhibition (stalk effect). Studies have demonstrated that increased intrasellar pressure is associated with both "stalk effect" hyperprolactinemia and pituitary insufficiency. Our primary hypothesis was that, despite continued disinhibition, lactotroph failure is responsible for normoprolactinemia in patients with large macroadenomas. As a corollary, we proposed that the hyperprolactinemia phase, which presumably would precede the insufficiency/normoprolactinemic state, would more likely be discovered in premenopausal females and go unnoticed in males. Prospective, consecutive surgical series of 98 patients of clinically nonfunctional pituitary adenomas. Lactotroph insufficiency was inferred by the coexistence of insufficiency in another pituitary axis. The existence of pre-operative lactotroph disinhibition was inferred based on comparison of pre- versus post-operative prolactin levels. 87 % of patients with tumor size >20 mm and normoprolactinemia had pituitary insufficiency. Pre-operative prolactin in patients with pituitary insufficiency were lower than those with intact pituitary function. Prolactin levels dropped in nearly all patients, including patients with normoprolactinemia pre-operatively. Premenopausal women had smaller tumors and higher pre-operative prolactin levels compared to males. No premenopausal female exhibited evidence of pituitary insufficiency. Our study provides suggestive evidence that the "stalk effect" pathophysiology is the norm rather than the exception, and that the finding of normoprolactinemia in a patient with a large macroadenoma is likely a consequence of lactotroph insufficiency. In males, the hyperprolactinemia window is more likely to be missed clinically due to an absence of prolactin-related symptoms.


Assuntos
Hiperprolactinemia/metabolismo , Lactotrofos/metabolismo , Hipófise/fisiopatologia , Neoplasias Hipofisárias/metabolismo , Prolactina/metabolismo , Adulto , Idoso , Feminino , Humanos , Hiperprolactinemia/etiologia , Hiperprolactinemia/cirurgia , Masculino , Pessoa de Meia-Idade , Hipófise/citologia , Hipófise/cirurgia , Neoplasias Hipofisárias/complicações , Neoplasias Hipofisárias/cirurgia
15.
J Microelectromech Syst ; 23(4): 795-802, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29151776

RESUMO

Here, we report on the development and evaluation of novel unobstructing magnetic microactuators for maintaining the patency of implantable ventricular catheters used in hydrocephalus application. The treatment of hydrocephalus requires chronic implantation of a shunt system to divert excess cerebrospinal fluid from the brain. These shunt systems suffer from a high failure rate (>40%) within the first year of implantation, often due to biological accumulation. Previously, we have shown that magnetic microactuators can be used to remove biological blockage. The new cantilever-based magnetic microactuator presented in this paper improves upon the previous torsional design using a bimorph to induce a postrelease out-of-plane deflection that will prevent the device from occluding the pore at rest. The mechanical evaluations (i.e., postrelease deflection, static and dynamic responses) of fabricated devices are reported and compared with theoretical values.

16.
Neurosurg Focus ; 37(5): E7, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26223274

RESUMO

OBJECT: Knowledge of the costs incurred through the delivery of neurosurgical care has been lagging, making it challenging to design impactful cost-containment initiatives. In this report, the authors describe a detailed cost analysis for pituitary surgery episodes of care and demonstrate the importance of such analyses in helping to identify high-impact cost activities and drive value-based care. METHODS: This was a retrospective study of consecutively treated patients undergoing an endoscopic endonasal procedure for the resection of a pituitary adenoma after implementation and maturation of quality-improvement initiatives and the implementation of cost-containment initiatives. RESULTS: The cost data pertaining to 27 patients were reviewed. The 2 most expensive cost activities during the index hospitalization were the total operating room (OR) and total bed-assignment costs. Together, these activities represented more than 60% of the cost of hospitalization. Although value-improvement initiatives contributed to the reduction of variation in the total cost of hospitalization, specific cost activities remained relatively variable, namely the following: 1) OR charged supplies, 2) postoperative imaging, and 3) use of intraoperative neuromonitoring. These activities, however, each contributed to less than 10% of the cost of hospitalization. Bed assignment was the fourth most variable cost activity. Cost related to readmission/reoperation represented less than 5% of the total cost of the surgical episode of care. CONCLUSIONS: After completing a detailed assessment of costs incurred throughout the management of patients undergoing pituitary surgery, high-yield opportunities for cost containment should be identified among the most expensive activities and/or those with the highest variation. Strategies for safely reducing the use of the targeted resources, and related costs incurred, should be developed by the multidisciplinary team providing care for this patient population.


Assuntos
Adenoma/economia , Hospitalização/economia , Neuroendoscopia/economia , Neoplasias Hipofisárias/economia , Neoplasias Hipofisárias/cirurgia , Adenoma/cirurgia , Adolescente , Adulto , Idoso , Controle de Custos/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Salas Cirúrgicas/economia , Papel do Médico , Estudos Retrospectivos , Adulto Jovem
17.
Eur J Endocrinol ; 190(6): 467-478, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38781434

RESUMO

OBJECTIVE: Unravel the potential mechanism(s) of the on- and off-target actions of dopamine agonist therapy in both human prolactinoma tumors and neighboring stromal and immune cells. DESIGN AND METHODS: Five surgically resected prolactinomas (PRLomas) from 3 cabergoline (CBG)-treated patients and 2 treatment-naive patients were analyzed by using single-cell RNA sequencing (scRNA-seq) to compare the cellular composition and transcriptional landscape. RESULTS: Six major cell populations, namely tumor (88.2%), immune (5.6%), stromal (4.9%), progenitor cells (0.6%), proliferating cells (0.4%), and erythrocytes (0.2%), were observed. Tumor cells from CBG-treated patients expressed lower levels of genes that regulated hormone secretion, such as SCG2, VGF, TIMP1, NNAT, and CALD1, consistent with the inhibitory effects of CBG on hormone processing and secretion. Interestingly, we also observed an increased number of CD8+ T cells in the CBG-treated tissues. These cytotoxic CD8+ T cells expressed killing granule components such as perforin and the granzymes GZMB, GNLY, and KLRD1 as well as the inflammatory cytokine CCL5. Immune cell activation of these CD8+ T cells was further analyzed in a compartment-specific manner, and increased CD25 (IL2R) expression was noted in the CD8+ T cells from the CBG-treated samples. Additionally, and confirming prior reports, we noted a higher stromal cell population in the CBG-treated samples. CONCLUSIONS: Our scRNA-seq studies revealed key differences in the transcriptomic features of CBG-treated and CBG-untreated PRLomas in both tumor and microenvironment cellular constituents, and for the first time, describe the previously unknown activation of CD8+ T cells following CBG treatment, which may play a role in the tumoricidal actions of CBG.


Assuntos
Cabergolina , Neoplasias Hipofisárias , Prolactinoma , Humanos , Cabergolina/farmacologia , Cabergolina/uso terapêutico , Prolactinoma/tratamento farmacológico , Prolactinoma/metabolismo , Masculino , Feminino , Neoplasias Hipofisárias/metabolismo , Neoplasias Hipofisárias/tratamento farmacológico , Neoplasias Hipofisárias/patologia , Adulto , Pessoa de Meia-Idade , Fibrose , Prolactina/metabolismo , Agonistas de Dopamina/farmacologia , Agonistas de Dopamina/uso terapêutico , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/metabolismo , Células Estromais/efeitos dos fármacos , Células Estromais/metabolismo , Adulto Jovem , Microambiente Tumoral/efeitos dos fármacos
18.
J Neurol Surg B Skull Base ; 85(1): 15-20, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38274484

RESUMO

Objective While postoperative cerebrospinal fluid (CSF) leak rates of pituitary tumors have been frequently studied, there are fewer studies examining postoperative CSF leak rates for extrasellar tumors. The purpose of this study was to identify risk factors for the development of postoperative CSF leak in patients undergoing endoscopic surgery for extrasellar tumors. Methods A retrospective chart review was done for patients who underwent endoscopic resection for extrasellar tumors between 2008 and 2020. Age, gender, tumor type, tumor location, tumor size, reconstruction technique, medical comorbidities, and other potential risk factors were identified. Data was analyzed to identify significant risk factors for development of postoperative CSF leak. Results There were 100 patients with extrasellar tumors who developed intraoperative CSF leaks. Seventeen patients (17%) developed postoperative CSF leaks. Leaks occurred at a median of 2 days following surgery (range 0-34 days). Clival tumors had a significantly higher incidence of postoperative leak than those in other sites ( p < 0.05). There were no significant differences in other locations, body mass index, tumor size, reconstruction technique, medical comorbidities, or other factors. There were nearly twice as many intraoperative grade III leaks in those who developed postoperative CSF leak, but this was not statistically significant ( p = 0.12). Conclusion Extrasellar tumors, particularly clival tumors, have a higher rate of postoperative CSF leak than pituitary tumors. Prophylactic lumbar drains can be considered for patients at high risk for developing postoperative CSF leak.

19.
Artigo em Inglês | MEDLINE | ID: mdl-38646913

RESUMO

KEY POINTS: Patients with giant adenomas are more likely to have tumor extension into the paranasal sinuses. Compared to macroadenomas, giant adenomas are not associated with worse preoperative SNOT-22 scores.

20.
World Neurosurg ; 175: e465-e472, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37024082

RESUMO

OBJECTIVE: To identify factors associated with successful use of free tissue grafting versus vascularized reconstruction after resection of pituitary tumors. METHODS: A retrospective chart review of 2 tertiary academic medical centers over 3.5 years was conducted. Variables assessed included age, sex, body mass index, pathology, extent of surgical exposure, cavernous sinus or suprasellar extension, intraoperative cerebrospinal fluid (CSF) leak, grade of leak, previous radiation, and previous surgery. Reconstructive techniques were divided into no reconstruction, free tissue grafts, and vascularized flaps. RESULTS: A total of 485 patients were included. Free grafts were used in 299/485 cases (61.6%) and were more commonly used with smaller approaches (P < 0.001). Larger exposure size and CSF leak grades 2 and 3 were associated with vascularized flap use (P < 0.001 and P = 0.012, respectively). Using multivariate regression, type of reconstruction could be predicted by increasing extent of approach, intraoperative CSF leak grade, and suprasellar extension (odds ratio [OR], 2.014, P < 0.001, 95% confidence interval [CI], 1.335-3.039; OR, 1.636, P = 0.025, 95% CI, 1.064-2.517; OR, 1.975, P < 0.001, 95% CI, 1.554-2.510, respectively). Postoperative CSF leak occurred in 9 of 173 patients (5.2%) with intraoperative leak and was not associated with any factors on analysis. CONCLUSIONS: We propose an algorithm whereby grade 1 CSF leaks in sellar and parasellar resections can be successfully reconstructed with a free graft. Vascularized flaps may be reserved for grade 2 or 3 intraoperative CSF leaks, extended approaches, or tumors with suprasellar extension.


Assuntos
Neoplasias Hipofisárias , Procedimentos de Cirurgia Plástica , Humanos , Neoplasias Hipofisárias/cirurgia , Estudos Retrospectivos , Base do Crânio/cirurgia , Vazamento de Líquido Cefalorraquidiano/epidemiologia , Vazamento de Líquido Cefalorraquidiano/etiologia , Vazamento de Líquido Cefalorraquidiano/cirurgia , Complicações Pós-Operatórias/cirurgia , Tecido Conjuntivo , Endoscopia/métodos
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