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1.
Cell ; 186(4): 764-785.e21, 2023 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-36803604

RESUMEN

The choroid plexus (ChP) is the blood-cerebrospinal fluid (CSF) barrier and the primary source of CSF. Acquired hydrocephalus, caused by brain infection or hemorrhage, lacks drug treatments due to obscure pathobiology. Our integrated, multi-omic investigation of post-infectious hydrocephalus (PIH) and post-hemorrhagic hydrocephalus (PHH) models revealed that lipopolysaccharide and blood breakdown products trigger highly similar TLR4-dependent immune responses at the ChP-CSF interface. The resulting CSF "cytokine storm", elicited from peripherally derived and border-associated ChP macrophages, causes increased CSF production from ChP epithelial cells via phospho-activation of the TNF-receptor-associated kinase SPAK, which serves as a regulatory scaffold of a multi-ion transporter protein complex. Genetic or pharmacological immunomodulation prevents PIH and PHH by antagonizing SPAK-dependent CSF hypersecretion. These results reveal the ChP as a dynamic, cellularly heterogeneous tissue with highly regulated immune-secretory capacity, expand our understanding of ChP immune-epithelial cell cross talk, and reframe PIH and PHH as related neuroimmune disorders vulnerable to small molecule pharmacotherapy.


Asunto(s)
Plexo Coroideo , Hidrocefalia , Humanos , Barrera Hematoencefálica/metabolismo , Encéfalo/metabolismo , Plexo Coroideo/metabolismo , Hidrocefalia/líquido cefalorraquídeo , Hidrocefalia/inmunología , Inmunidad Innata , Síndrome de Liberación de Citoquinas/patología
2.
Clin Chem ; 70(7): 978-986, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38757262

RESUMEN

BACKGROUND: Abuse of fentanyl and its analogs is a major contributor to the opioid overdose epidemic in the United States, but detecting and quantifying trace amounts of such drugs remains a challenge without resorting to sophisticated mass spectrometry-based methods. METHODS: A sensitive immunoassay with a sub-picogram limit of detection for fentanyl and a wide range of fentanyl analogs has been developed, using a novel high-affinity antibody fused with NanoLuc, a small-size luciferase that can emit strong and stable luminescence. When used with human urine samples, the assay has a sub-picogram limit of detection for fentanyl, with results fully concordant with LC-MS. RESULTS: When applied to clinical samples, the novel chemiluminescence immunoassay can detect low positive fentanyl missed by routine screening immunoassays, with a limit of detection of 0.8 pg/mL in human urine. When applied to environmental samples, the assay can detect levels as low as 0.25 pg fentanyl per inch2 of environment surface. Assay turnaround time is less than 1 h, with inexpensive equipment and the potential for high-throughput automation or in-field screening. CONCLUSIONS: We have established a novel assay that may have broad applications in clinical, environmental, occupational, and forensic scenarios for detection of trace amounts of fentanyl and its analogs.


Asunto(s)
Fentanilo , Mediciones Luminiscentes , Fentanilo/orina , Fentanilo/análisis , Humanos , Inmunoensayo/métodos , Mediciones Luminiscentes/métodos , Límite de Detección , Detección de Abuso de Sustancias/métodos , Analgésicos Opioides/orina , Analgésicos Opioides/análisis
3.
Am J Med Genet A ; : e63638, 2024 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-38779990

RESUMEN

Myhre syndrome is an increasingly diagnosed ultrarare condition caused by recurrent germline autosomal dominant de novo variants in SMAD4. Detailed multispecialty evaluations performed at the Massachusetts General Hospital (MGH) Myhre Syndrome Clinic (2016-2023) and by collaborating specialists have facilitated deep phenotyping, genotyping and natural history analysis. Of 47 patients (four previously reported), most (81%) patients returned to MGH at least once. For patients followed for at least 5 years, symptom progression was observed in all. 55% were female and 9% were older than 18 years at diagnosis. Pathogenic variants in SMAD4 involved protein residues p.Ile500Val (49%), p.Ile500Thr (11%), p.Ile500Leu (2%), and p.Arg496Cys (38%). Individuals with the SMAD4 variant p.Arg496Cys were less likely to have hearing loss, growth restriction, and aortic hypoplasia than the other variant groups. Those with the p.Ile500Thr variant had moderate/severe aortic hypoplasia in three patients (60%), however, the small number (n = 5) prevented statistical comparison with the other variants. Two deaths reported in this cohort involved complex cardiovascular disease and airway stenosis, respectively. We provide a foundation for ongoing natural history studies and emphasize the need for evidence-based guidelines in anticipation of disease-specific therapies.

4.
J Pathol ; 260(1): 43-55, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36752189

RESUMEN

Neuroendocrine (NE) cells comprise ~1% of epithelial cells in benign prostate and prostatic adenocarcinoma (PCa). However, they become enriched in hormonally treated and castration-resistant PCa (CRPC). In addition, close to 20% of hormonally treated tumors recur as small cell NE carcinoma (SCNC), composed entirely of NE cells, which may be the result of clonal expansion or lineage plasticity. Since NE cells do not express androgen receptors (ARs), they are resistant to hormonal therapy and contribute to therapy failure. Here, we describe the identification of glypican-3 (GPC3) as an oncofetal cell surface protein specific to NE cells in prostate cancer. Functional studies revealed that GPC3 is critical to the viability of NE tumor cells and tumors displaying NE differentiation and that it regulates calcium homeostasis and signaling. Since our results demonstrate that GPC3 is specifically expressed by NE cells, patients with confirmed SCNC may qualify for GPC3-targeted therapy which has been developed in the context of liver cancer and displays minimal toxicity due to its tumor-specific expression. © 2023 The Pathological Society of Great Britain and Ireland.


Asunto(s)
Adenocarcinoma , Células Neuroendocrinas , Neoplasias de la Próstata , Masculino , Humanos , Células Neuroendocrinas/metabolismo , Células Neuroendocrinas/patología , Glipicanos/metabolismo , Adenocarcinoma/patología , Recurrencia Local de Neoplasia/patología , Neoplasias de la Próstata/patología , Biomarcadores/metabolismo
5.
Cereb Cortex ; 33(8): 4262-4279, 2023 04 04.
Artículo en Inglés | MEDLINE | ID: mdl-36097331

RESUMEN

Pediatric hydrocephalus, the leading reason for brain surgery in children, is characterized by enlargement of the cerebral ventricles classically attributed to cerebrospinal fluid (CSF) overaccumulation. Neurosurgical shunting to reduce CSF volume is the default treatment that intends to reinstate normal CSF homeostasis, yet neurodevelopmental disability often persists in hydrocephalic children despite optimal surgical management. Here, we discuss recent human genetic and animal model studies that are shifting the view of pediatric hydrocephalus from an impaired fluid plumbing model to a new paradigm of dysregulated neural stem cell (NSC) fate. NSCs are neuroprogenitor cells that comprise the germinal neuroepithelium lining the prenatal brain ventricles. We propose that heterogenous defects in the development of these cells converge to disrupt cerebrocortical morphogenesis, leading to abnormal brain-CSF biomechanical interactions that facilitate passive pooling of CSF and secondary ventricular distention. A significant subset of pediatric hydrocephalus may thus in fact be due to a developmental brain malformation leading to secondary enlargement of the ventricles rather than a primary defect of CSF circulation. If hydrocephalus is indeed a neuroradiographic presentation of an inborn brain defect, it suggests the need to focus on optimizing neurodevelopment, rather than CSF diversion, as the primary treatment strategy for these children.


Asunto(s)
Hidrocefalia , Células-Madre Neurales , Animales , Niño , Humanos , Hidrocefalia/cirugía , Encéfalo , Ventrículos Cerebrales , Procedimientos Neuroquirúrgicos
6.
Pediatr Dermatol ; 41(4): 677-679, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38621697

RESUMEN

Several dermatologic concerns are known to disproportionally affect transgender and gender-diverse (TGD) adults, but little is known about dermatologic conditions in TGD youth. This study assesses the prevalence of acne, androgenic alopecia, scarring from gender-affirming procedures, and eczema in pediatric TGD patients seen at Boston Children's Hospital between April 2021 and April 2022. The results demonstrate that, for TGD youth, the studied dermatologic concerns are common, referral rates to dermatology are low, and acne is significantly associated with testosterone use. Future studies should examine additional dermatologic concerns and barriers to accessing dermatologic care for this historically underserved population.


Asunto(s)
Acné Vulgar , Personas Transgénero , Humanos , Femenino , Estudios Retrospectivos , Masculino , Adolescente , Personas Transgénero/estadística & datos numéricos , Acné Vulgar/epidemiología , Niño , Alopecia/epidemiología , Eccema/epidemiología , Prevalencia , Cicatriz , Enfermedades de la Piel/epidemiología , Procedimientos de Reasignación de Sexo
7.
Neurobiol Dis ; 175: 105913, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36341771

RESUMEN

Dysfunction of motile cilia in ependymal cells has been proposed to be a pathogenic cause of cerebrospinal fluid (CSF) overaccumulation leading to ventricular expansion in hydrocephalus, primarily based on observations of enlarged ventricles in mouse models of primary ciliary dyskinesia. Here, we review human and animal evidence that warrants a rethinking of the cilia hypothesis in hydrocephalus. First, we discuss neuroembryology and physiology data that do not support a role for ependymal cilia as the primary propeller of CSF movement across the ventricles in the human brain, particularly during in utero development prior to the functional maturation of ependymal cilia. Second, we highlight that in contrast to mouse models, motile ciliopathies infrequently cause hydrocephalus in humans. Instead, gene mutations affecting motile cilia function impact not only ependymal cilia but also motile cilia found in other organ systems outside of the brain, causing a clinical syndrome of recurrent respiratory infections and situs inversus, symptoms that do not typically accompany most cases of human hydrocephalus. Finally, we postulate that certain cases of hydrocephalus associated with ciliary gene mutations may arise not necessarily just from loss of cilia-generated CSF flow but also from altered neurodevelopment, given the potential functions of ciliary genes in signaling and neural stem cell fate beyond generating fluid flow. Further investigations are needed to clarify the link between motile cilia, CSF physiology, and brain development, the understanding of which has implications for the care of patients with hydrocephalus and other related neurodevelopmental disorders.


Asunto(s)
Cilios , Hidrocefalia , Animales , Ratones , Humanos , Cilios/patología , Hidrocefalia/etiología , Hidrocefalia/patología , Epéndimo/patología , Encéfalo/patología , Modelos Animales de Enfermedad
8.
J Am Acad Dermatol ; 87(6): 1295-1302, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36063987

RESUMEN

BACKGROUND: Although immunocompromised patients have a higher risk of developing cutaneous squamous cell carcinomas, it is unknown whether immune status is an independent risk factor for poor outcomes. OBJECTIVE: To compare cutaneous squamous cell carcinoma outcomes in immunocompromised and immunocompetent patients when controlling for T-stage. METHODS: We performed a retrospective cohort study at 2 tertiary care centers, examining 989 primary tumors from 814 immunocompromised patients (solid organ transplant: 259 [31.7%], chronic lymphocytic leukemia: 113 [13.9%]) and 6608 tumors from 4198 immunocompetent patients. Our primary outcome was the composite of disease-specific death or tumor metastasis ("poor outcomes"). RESULTS: Immunocompromised patients had 50% more high T-stage tumors (ie, Brigham and Women's Hospital stage T2b and T3), than immunocompetent patients (3.3% vs 4.9%, respectively; P < .001). Significant predictors of poor outcomes included tumor stage (sub hazards ratio [SHR], 14.8 for high T-stage tumors; 95% confidence interval [CI], 8.0-27.6; P < .001) and male sex (SHR, 2.3; 95% CI, 1.4-3.8; P = .002). Immune status was not a significant predictor (SHR, 1.04; 95% CI, 0.69-1.6; P = .85). LIMITATIONS: This study is retrospective. CONCLUSION: Although immunocompromised patients had 50% more high T-stage tumors than immunocompetent patients, immunocompromised patients had a similar chance of metastasis and disease-specific death when adjusting for T-stage in our cohort of primary tumors.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias Cutáneas , Humanos , Masculino , Femenino , Carcinoma de Células Escamosas/patología , Estudios Retrospectivos , Neoplasias Cutáneas/patología , Estadificación de Neoplasias , Estudios de Cohortes
9.
J Neurooncol ; 154(1): 1-11, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34251602

RESUMEN

BACKGROUND: Stereotactic needle biopsy remains the cornerstone for tissue diagnosis for tumors located in regions of the brain that are difficult to access through open surgery. OBJECTIVE: We perform a meta-analysis of the literature to examine the relation between number of samples taken during biopsy and diagnostic yield, morbidity and mortality. METHODS: We identified 2416 patients from 28 cohorts in studies published in PubMed database that studied stereotactic needle biopsies for tumor indications. Meta-analysis by proportions and meta-regression analyses were performed. RESULTS: On meta-analysis, the morbidity profile of the published needle biopsy studies clustered into three groups: studies that performed < 3 samples (n = 8), 3-6 samples (n = 13), and > 6 samples during biopsy (n = 7). Pooled estimates for biopsy related morbidity were 4.3%, 16.3%, and 17% for studies reporting < 3, 3-6, and > 6 biopsy samples, respectively. While these morbidity estimates significantly differed (p < 0.001), the diagnostic yields reported for studies performing < 3 biopsies, 3-6 samples, and > 6 samples were comparable. Pooled estimates of diagnostic yield for these three groups were 90.4%, 93.8%, and 88.1%, respectively. Mortality did not significantly differ between studies reporting differing number of samples taken during biopsy. CONCLUSIONS: Our meta-analysis suggests that morbidity risk in needle biopsy is non-linearly associated with the number of samples taken. There was no association between the number of biopsies taken, and diagnostic yield or mortality.


Asunto(s)
Biopsia con Aguja , Neoplasias Encefálicas , Técnicas Estereotáxicas , Biopsia con Aguja/efectos adversos , Biopsia con Aguja/estadística & datos numéricos , Neoplasias Encefálicas/mortalidad , Neoplasias Encefálicas/patología , Humanos , Técnicas Estereotáxicas/efectos adversos , Resultado del Tratamiento
10.
Gynecol Endocrinol ; 37(9): 798-801, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33355011

RESUMEN

OBJECTIVE: To evaluate the role of discordant Day-3 follicle stimulating hormone (FSH) & anti-Müllerian hormone (AMH) levels in predicting pregnancy outcome after controlled ovarian stimulation (COS) followed by intrauterine insemination or timed intercourse. METHODS: Retrospective study of 745 couples with regular menstrual cycles, at least one patent fallopian tube, and normal semen analysis that underwent infertility treatment between June 2013 and March 2017. Women with documented serum AMH and FSH levels (<10 (mIU/ml were considered normal), and undergo COS were studied. Clinical pregnancy rate is the cumulative pregnancy obtained after maximum of three cycles of COS with or without IUI. RESULTS: As expected, patients with normal concordant AMH/FSH achieved a significantly (p < .01) higher pregnancy than all other groups. 22.4% of those with discordant normal AMH/abnormal FSH became pregnant while only 10.8% of those with discordant abnormal AMH/normal FSH levels did. 11.7% of patients with abnormal concordant values achieved pregnancy. Patients with discordant abnormal AMH/normal FSH were not statistically different (p = .084) from abnormal concordance AMH/FSH but significantly (p < .01) lower than normal concordant AMH/FSH. However, patients with discordant normal AMH/abnormal FSH were statistically different from both concordant normal and concordant abnormal AMH/FSH values (p < .04). CONCLUSIONS: This study showed that both discordant abnormal Day-3 FSH and/or abnormal AMH serum levels, as well as concordant abnormal FSH and AMH values, were predictive of lower clinical pregnancy rates after COS. However, abnormal FSH with a normal AMH does not have as poor a prognosis as the presence of an abnormal AMH.


Asunto(s)
Hormona Antimülleriana/sangre , Hormona Folículo Estimulante/sangre , Infertilidad Femenina/terapia , Inducción de la Ovulación , Resultado del Embarazo , Técnicas Reproductivas Asistidas/estadística & datos numéricos , Adulto , Femenino , Humanos , Inseminación Artificial , Masculino , Reserva Ovárica , Embarazo , Índice de Embarazo , Estudios Retrospectivos , Resultado del Tratamiento
11.
Pediatr Transplant ; 24(2): e13646, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31960553

RESUMEN

Evaluation for liver transplant candidacy is a multidisciplinary effort that involves all aspects of clinical care including social work, nutrition, and a multitude of medical specialties. The prognosis of a pretransplant clinical condition is integrated into the decision to list a patient. Herein, we report a successful liver transplant and recovery of a 3-month-old male following a large right hemispheric subdural hematoma related to acute coagulopathy secondary to undiagnosed end-stage liver disease. On presentation with jaundice, lethargy, and unequal pupils, a CT scan was obtained which demonstrated a large right subdural hematoma with herniation. Once his coagulopathy was corrected, he went for decompressive craniectomy. He survived with medically controlled seizures and improving L-sided neglect and extremity weakness. Six weeks later, given his continued neurologic recovery and worsening liver function, the decision was made to list him for liver transplantation. One month later, he underwent orthotopic liver transplant. His post-operative hospital course was complicated by DVTs and heparin-induced thrombocytopenia, but no neurologic decline, and he was eventually discharged from the hospital on post-op day 26. Three years later, he has a well-functioning allograft and no clinically evident neurologic deficits. The prognosis following pediatric neurologic trauma remains somewhat unclear as recovery and neurologic examinations can be influenced by numerous extrinsic factors. This is one of the first reports of near full neurologic recovery of a pediatric liver transplant recipient following a large subdural hematoma with herniation.


Asunto(s)
Enfermedad Hepática en Estado Terminal/cirugía , Hematoma Subdural/etiología , Trasplante de Hígado , Enfermedad Hepática en Estado Terminal/complicaciones , Enfermedad Hepática en Estado Terminal/diagnóstico , Humanos , Lactante , Masculino
13.
N Engl J Med ; 374(15): 1424-34, 2016 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-27074067

RESUMEN

BACKGROUND: The comparative effectiveness of performing instrumented (rigid pedicle screws affixed to titanium alloy rods) lumbar spinal fusion in addition to decompressive laminectomy in patients with symptomatic lumbar grade I degenerative spondylolisthesis with spinal stenosis is unknown. METHODS: In this randomized, controlled trial, we assigned patients, 50 to 80 years of age, who had stable degenerative spondylolisthesis (degree of spondylolisthesis, 3 to 14 mm) and symptomatic lumbar spinal stenosis to undergo either decompressive laminectomy alone (decompression-alone group) or laminectomy with posterolateral instrumented fusion (fusion group). The primary outcome measure was the change in the physical-component summary score of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36; range, 0 to 100, with higher scores indicating better quality of life) 2 years after surgery. The secondary outcome measure was the score on the Oswestry Disability Index (range, 0 to 100, with higher scores indicating more disability related to back pain). Patients were followed for 4 years. RESULTS: A total of 66 patients (mean age, 67 years; 80% women) underwent randomization. The rate of follow-up was 89% at 1 year, 86% at 2 years, and 68% at 4 years. The fusion group had a greater increase in SF-36 physical-component summary scores at 2 years after surgery than did the decompression-alone group (15.2 vs. 9.5, for a difference of 5.7; 95% confidence interval, 0.1 to 11.3; P=0.046). The increases in the SF-36 physical-component summary scores in the fusion group remained greater than those in the decompression-alone group at 3 years and at 4 years (P=0.02 for both years). With respect to reductions in disability related to back pain, the changes in the Oswestry Disability Index scores at 2 years after surgery did not differ significantly between the study groups (-17.9 in the decompression-alone group and -26.3 in the fusion group, P=0.06). More blood loss and longer hospital stays occurred in the fusion group than in the decompression-alone group (P<0.001 for both comparisons). The cumulative rate of reoperation was 14% in the fusion group and 34% in the decompression-alone group (P=0.05). CONCLUSIONS: Among patients with degenerative grade I spondylolisthesis, the addition of lumbar spinal fusion to laminectomy was associated with slightly greater but clinically meaningful improvement in overall physical health-related quality of life than laminectomy alone. (Funded by the Jean and David Wallace Foundation and others; SLIP ClinicalTrials.gov number, NCT00109213.).


Asunto(s)
Laminectomía , Vértebras Lumbares/cirugía , Fusión Vertebral , Estenosis Espinal/cirugía , Espondilolistesis/cirugía , Anciano , Anciano de 80 o más Años , Descompresión Quirúrgica , Evaluación de la Discapacidad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Reoperación/estadística & datos numéricos , Estenosis Espinal/complicaciones , Espondilolistesis/complicaciones , Resultado del Tratamiento
15.
J Neurophysiol ; 117(5): 1847-1852, 2017 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-28250151

RESUMEN

The head direction (HD) circuit is a complex interconnected network of brain regions ranging from the brain stem to the cortex. Recent work found that HD cells corecorded ipsilaterally in the anterodorsal nucleus (ADN) of the thalamus displayed coordinated firing patterns. A high-frequency oscillation pattern (130-160 Hz) was visible in the cross-correlograms of these HD cell pairs. Spectral analysis further found that the power of this oscillation was greatest at 0 ms and decreased at greater lags, and demonstrated that there was greater synchrony between HD cells with similar preferred firing directions. Here, we demonstrate that the same high-frequency synchrony exists in HD cell pairs recorded contralaterally from one another in the bilateral ADN. When we examined the cross-correlograms of HD cells that were corecorded bilaterally, we observed the same high-frequency (~150- to 200-Hz) oscillatory relationship. The strength of this synchrony was similar to the synchrony seen in ipsilateral HD cell pairs, and the degree of synchrony in each cross-correlogram was dependent on the difference in tuning between the two cells. Additionally, the frequency rate of this oscillation appeared to be independent of the firing rates of the two cross-correlated cells. Taken together, these results imply that the left and right thalamic HD network are functionally related despite an absence of direct anatomical projections. However, anatomical tracing has found that each of the lateral mammillary nuclei (LMN) project bilaterally to both of the ADN, suggesting the LMN may be responsible for the functional connectivity observed between the two ADN.NEW & NOTEWORTHY This study used bilateral recording electrodes to examine whether head direction cells recorded simultaneously in both the left and right thalamus show coordinated firing. Cross-correlations of the cells' spike trains revealed a high-frequency oscillatory pattern similar to that seen in cross-correlations between pairs of ipsilateral head direction cells, demonstrating that the bilateral thalamic head direction signals may be part of a single unified network.


Asunto(s)
Núcleos Talámicos Anteriores/fisiología , Ondas Encefálicas , Navegación Espacial , Animales , Núcleos Talámicos Anteriores/citología , Femenino , Lateralidad Funcional , Neuronas/fisiología , Ratas , Ratas Long-Evans
17.
J Neurosci ; 35(6): 2547-58, 2015 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-25673848

RESUMEN

Head direction (HD) cells in the rat limbic system fire according to the animal's orientation independently of the animal's environmental location or behavior. These HD cells receive strong inputs from the vestibular system, among other areas, as evidenced by disruption of their directional firing after lesions or inactivation of vestibular inputs. Two brainstem nuclei, the supragenual nucleus (SGN) and nucleus prepositus hypoglossi (NPH), are known to project to the HD network and are thought to be possible relays of vestibular information. Previous work has shown that lesioning the SGN leads to a loss of spatial tuning in downstream HD cells, but the NPH has historically been defined as an oculomotor nuclei and therefore its role in contributing to the HD signal is less clear. Here, we investigated this role by recording HD cells in the anterior thalamus after either neurotoxic or electrolytic lesions of the NPH. There was a total loss of direction-specific firing in anterodorsal thalamus cells in animals with complete NPH lesions. However, many cells were identified that fired in bursts unrelated to the animals' directional heading and were similar to cells seen in previous studies that damaged vestibular-associated areas. Some animals with significant but incomplete lesions of the NPH had HD cells that were stable under normal conditions, but were unstable under conditions designed to minimize the use of external cues. These results support the hypothesis that the NPH, beyond its traditional oculomotor function, plays a critical role in conveying vestibular-related information to the HD circuit.


Asunto(s)
Movimientos de la Cabeza/fisiología , Sistema Límbico/fisiología , Orientación/fisiología , Puente/fisiología , Animales , Conducta Animal/fisiología , Señales (Psicología) , Electrodos Implantados , Fenómenos Electrofisiológicos , Femenino , Sistema Límbico/citología , Neuronas/fisiología , Ratas , Ratas Long-Evans , Tálamo/fisiología , Vestíbulo del Laberinto/fisiología
18.
Ann Surg ; 264(1): 81-6, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26501698

RESUMEN

OBJECTIVE: To determine whether patients who learned the views of an expert surgeons' panel's assessment of equipoise between 2 alternative operative treatments had increased likelihood of consenting to randomization. BACKGROUND: Difficulty obtaining patient consent to randomization is an important barrier to conducting surgical randomized clinical trials, the gold standard for generating clinical evidence. METHODS: Observational study of the rate of patient acceptance of randomization within a 5-center randomized clinical trial comparing lumbar spinal decompression versus lumbar spinal decompression plus instrumented fusion for patients with symptomatic grade I degenerative lumbar spondylolisthesis with spinal stenosis. Eligible patients were enrolled in the trial and then asked to accept randomization. A panel of 10 expert spine surgeons was formed to review clinical information and images for individual patients to provide an assessment of suitability for randomization. The expert panel vote was disclosed to the patient by the patient's surgeon before the patient decided whether to accept randomization or not. RESULTS: Randomization acceptance among eligible patients without expert panel review was 40% (19/48) compared with 81% (47/58) among patients undergoing expert panel review (P < 0.001). Among expert-reviewed patients, randomization acceptance was 95% when all experts or all except 1 voted for randomization, 75% when 2 experts voted against randomization, and 20% with 3 or 4 votes against (P < 0.001 for trend). CONCLUSIONS: Patients provided with an expert panel's assessment of their own suitability for randomization were twice as likely to agree to randomization compared with patients receiving only their own surgeon's recommendation.


Asunto(s)
Laminectomía/métodos , Vértebras Lumbares , Estenosis Espinal/cirugía , Espondilolistesis/cirugía , Anciano , Anciano de 80 o más Años , Descompresión Quirúrgica/métodos , Femenino , Estudios de Seguimiento , Humanos , Laminectomía/instrumentación , Masculino , Persona de Mediana Edad , Selección de Paciente , Guías de Práctica Clínica como Asunto , Estudios Prospectivos , Estenosis Espinal/diagnóstico por imagen , Espondilolistesis/diagnóstico por imagen , Resultado del Tratamiento , Estados Unidos
19.
Environ Manage ; 55(3): 564-77, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25549996

RESUMEN

The Collaborative Forest Landscape Restoration Program (CFLRP), established in 2009, encourages collaborative landscape scale ecosystem restoration efforts on United States Forest Service (USFS) lands. Although the USFS employees have experience engaging in collaborative planning, CFLRP requires collaboration in implementation, a domain where little prior experience can be drawn on for guidance. The purpose of this research is to identify the ways in which CFLRP's collaborative participants and agency personnel conceptualize how stakeholders can contribute to implementation on landscape scale restoration projects, and to build theory on dynamics of collaborative implementation in environmental management. This research uses a grounded theory methodology to explore collaborative implementation from the perspectives and experiences of participants in landscapes selected as part of the CFLRP in 2010. Interviewees characterized collaborative implementation as encompassing three different types of activities: prioritization, enhancing treatments, and multiparty monitoring. The paper describes examples of activities in each of these categories and then identifies ways in which collaborative implementation in the context of CFLRP (1) is both hindered and enabled by overlapping legal mandates about agency collaboration, (2) creates opportunities for expanded accountability through informal and relational means, and, (3) creates feedback loops at multiple temporal and spatial scales through which monitoring information, prioritization, and implementation actions shape restoration work both within and across projects throughout the landscape creating more robust opportunities for adaptive management.


Asunto(s)
Conservación de los Recursos Naturales/legislación & jurisprudencia , Conservación de los Recursos Naturales/métodos , Conducta Cooperativa , Ecosistema , Bosques , Política Pública , Responsabilidad Social , Humanos , Entrevistas como Asunto , Estados Unidos
20.
J Am Chem Soc ; 136(4): 1587-98, 2014 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-24400989

RESUMEN

Layered materials with controlled thickness down to monolayer are being intensively investigated for unraveling and harnessing their dimension-dependent properties. Copper antimony sulfide (CuSbS2) is a ternary layered semiconductor material that has been considered as an absorber material in thin film solar cells due to its optimal band gap (∼1.5 eV) with high absorption coefficient of over >10(4) cm(-1). We have for the first time developed solution-based approaches for the synthesis of mono-, few-, and multiple layers of CuSbS2. These include a colloidal bottom-up approach for the synthesis of CuSbS2 nanoplates with thicknesses from six layers to several layers, and a hybrid bottom-up-top-down approach for the formation of CuSbS2 mesobelts. The latter can be exfoliated by Li-ion intercalation and sonication to obtain layers down to monolayer thickness. Time-dependent TEM studies provide important insights into the growth mechanism of mesobelts. At the initial stage the nanoplates grow laterally to form nanosheets as the primary structure, followed by their folding and attachment through homoepitaxy to form prolate-like secondary structures. Eventually, these prolate-like structures form mesocrystals by oriented attachment crystal growth. The changes in optical properties with layer thickness down to monolayers have been studied. In order to understand the thickness-dependent optical and electrical properties, we have calculated the electronic structures of mono- and multiple layers (bulk) of CuSbS2 using the hybrid functional method (HSE 06). We find that the monolayers exhibit noticeably different properties from the multilayered or the bulk system, with a markedly increased band gap that is, however, compromised by the presence of localized surface states. These localized states are predominantly composed of energetically favorable Sb pz states, which break off from the rest of the Sb p states that would otherwise be at the top of the gap. The developed solution-based synthesis approaches are versatile and can likely be extended to other complex layered sulfides.

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