bluuebunny/crossref_metadata_2025_split huggingface dataset:
The benefit and risk of stereotactic radiosurgery for prolactinomas: an international multicenter cohort study
Authors: Hung Yi-Chieh , Lee Cheng-Chia , Yang Huai-che , Mohammed Nasser , Kearns Kathryn N. , Nabeel Ahmed M. , Abdel Karim Khaled , Emad Eldin Reem M. , El-Shehaby Amr M. N. , Reda Wael A. , Tawadros Sameh R. , Liscak Roman , Jezkova Jana , Lunsford L. Dade , Kano Hideyuki , Sisterson Nathaniel D. , Martínez Álvarez Roberto , Martínez Moreno Nuria E. , Kondziolka Douglas , Golfinos John G. , Grills Inga , Thompson Andrew , Borghei-Razavi Hamid , Maiti Tanmoy Kumar , Barnett Gene H. , McInerney James , Zacharia Brad E. , Xu Zhiyuan , Sheehan Jason P. 
Published: August 2019

OBJECTIVEThe most common functioning pituitary adenoma is prolactinoma. Patients with medically refractory or residual/recurrent tumors that are not amenable to resection can be treated with stereotactic radiosurgery (SRS). The aim of this multicenter study was to evaluate the role of SRS for treating prolactinomas.METHODSThis retrospective study included prolactinomas treated with SRS between 1997 and 2016 at ten institutions. Patients’ clinical and treatment parameters were investigated. Patients were considered to be in endocrine remission when they had a normal level of prolactin (PRL) without requiring dopamine agonist medications. Endocrine control was defined as endocrine remission or a controlled PRL level ≤ 30 ng/ml with dopamine agonist therapy. Other outcomes were evaluated including new-onset hormone deficiency, tumor recurrence, and new neurological complications.RESULTSThe study cohort comprised 289 patients. The endocrine remission rates were 28%, 41%, and 54% at 3, 5, and 8 years after SRS, respectively. Following SRS, 25% of patients (72/289) had new hormone deficiency. Sixty-three percent of the patients (127/201) with available data attained endocrine control. Three percent of patients (9/269) had a new visual complication after SRS. Five percent of the patients (13/285) were recorded as having tumor progression. A pretreatment PRL level ≤ 270 ng/ml was a predictor of endocrine remission (p = 0.005, adjusted HR 0.487). An increasing margin dose resulted in better endocrine control after SRS (p = 0.033, adjusted OR 1.087).CONCLUSIONSIn patients with medically refractory prolactinomas or a residual/recurrent prolactinoma, SRS affords remarkable therapeutic effects in endocrine remission, endocrine control, and tumor control. New-onset hypopituitarism is the most common adverse event.
Conflicts of interest in randomized controlled trials reported in neurosurgical journals
Authors: Staartjes Victor E. , Klukowska Anita M. , Sorba Elena L. , Schröder Marc L. 
Published: August 2019

OBJECTIVERandomized controlled trials (RCTs) form the basis of today’s evidence-based approach to medicine, and play a critical role in guidelines and the drug and device approval process. Conflicts of interest (COIs) are commonplace in medical research, but little is known about their influence. The authors aimed to evaluate the extent and influence of COIs in recent RCTs published in core neurosurgical journals using a cross-sectional analysis.METHODSThrough review of 6 general neurosurgical journals, all interventional RCTs published from January 2009 to January 2019 were identified. Because it is difficult to objectively assess study outcome, the authors opted for a strict rating approach based on the statistical significance of unambiguously reported primary endpoints, and the reported statistical protocol.RESULTSA total of 129 RCTs met the inclusion criteria. During the study period, the Journal of Neurosurgery published the largest number of RCTs (n = 40, 31%). Any potential COI was disclosed by 57%, and a mean of 12% of authors had a personal COI. Nonfinancial industry involvement was reported in 10%, while 31% and 20% received external support and sponsoring, respectively. Study registration was reported by 56%, while 51% of studies were blinded. Registration showed an increasing trend from 17% to 76% (p < 0.001). The median randomized sample size was 92 (interquartile range 50–153), and 8% were designed to investigate noninferiority or equality. Sixty-three RCTs (49%) unambiguously reported a primary endpoint, of which 13% were composite primary endpoints. In 43%, study outcome was positive, which was associated with a noninferiority design (31% vs 3%, p = 0.007) and a composite primary endpoint (46% vs 9%, p = 0.002). Potential COIs were not significantly associated with study positivity (69% vs 59%, p = 0.433). In the multivariate analysis, only a composite primary endpoint remained predictive of a positive study outcome (odds ratio 6.34, 95% confidence interval 1.51–33.61, p = 0.017).CONCLUSIONSThis analysis provides an overview of COIs and their potential influence on recent trials published in core neurosurgical journals. Reporting of primary endpoints, study registration, and uniform disclosure of COIs are crucial to ensure the quality of future neurosurgical randomized trials. COIs do not appear to significantly influence the outcome of randomized neurosurgical trials.
Form follows function: estimation of CSF flow in the third ventricle–aqueduct–fourth ventricle complex modeled as a diffuser/nozzle pump
Authors: Longatti Pierluigi , Fiorindi Alessandro , Peruzzo Paolo , Basaldella Luca , Susin Francesca Maria 
Published: August 2019

OBJECTIVEIn the last 20 years, researchers have debated cerebrospinal fluid (CSF) dynamics theories, commonly based on the classic bulk flow perspective. New hypotheses do not consider a possible hydraulic impact of the ventricular morphology. The present study investigates, by means of a mathematical model, the eventual role played by the geometric shape of the “third ventricle–aqueduct–fourth ventricle” complex in CSF circulation under the assumption that the complex behaves like a diffuser/nozzle (DN) pump.METHODSDN pumps are quite recent devices introduced as valveless micropumps in various industrial applications given their property of driving net flow when subjected to rhythmic pulsations. A novel peculiar DN pump configuration was adopted in this study to mimic the ventricular complex, with two reservoirs (the ventricles) and one tube provided with a conical reach (the aqueduct–proximal fourth ventricle). The flow was modeled according to the classic equations of laminar flow, and the external rhythmic pulsations forcing the system were reproduced as a pulsatile pressure gradient between the chambers. Several physiological scenarios were implemented with the integration of data acquired by MRI in 10 patients with no known pathology of CSF dynamics, and a quantitative analysis of the effect of geometric and hydraulic parameters (diverging angle, sizes, frequency of pulsations) on the CSF net flow was performed.RESULTSThe results showed a craniocaudal net flow in all the given values, consistent with the findings of cine MRI studies. Moreover, the net flow estimated for the analyzed cohort of patients ranged from 0.221 to 0.505 ml/min, remarkably close to the values found on phase contrast cine MRI in healthy subjects. Sensitivity analysis underlines the pivotal role of the DN configuration, as well as of the frequency of forcing pressure, which promotes a relevant net flow considering both the heart and respiration rate.CONCLUSIONSThis work suggests that the geometry of the third ventricle–aqueduct–fourth ventricle complex, which resembles a diverter, appears to be functional in the generation of a net craniocaudal flow and potentially has an impact on CSF dynamics. These conclusions can be drawn by observing the analogies between the shape of the ventricles and the geometry of DN pumps and by recognizing the basis of the mathematical model of the simplified third ventricle–aqueduct–fourth ventricle complex proposed.
Vasa vasorum formation is associated with rupture of intracranial aneurysms
Authors: Miyata Haruka , Imai Hirohiko , Koseki Hirokazu , Shimizu Kampei , Abekura Yu , Oka Mieko , Kawamata Takakazu , Matsuda Tetsuya , Nozaki Kazuhiko , Narumiya Shuh , Aoki Tomohiro 
Published: August 2019

OBJECTIVESubarachnoid hemorrhage (SAH) has a poor outcome despite modern advancements in medical care. The development of a novel therapeutic strategy to prevent rupture of intracranial aneurysms (IAs) or a novel diagnostic marker to predict rupture-prone lesions is thus mandatory. Therefore, in the present study, the authors established a rat model in which IAs spontaneously rupture and examined this model to clarify histopathological features associated with rupture of lesions.METHODSFemale Sprague Dawley rats were subjected to bilateral ovariectomy; the ligation of the left common carotid, the right external carotid, and the right pterygopalatine arteries; induced systemic hypertension; and the administration of a lysyl oxidase inhibitor.RESULTSAneurysmal SAH occurred in one-third of manipulated animals and the locations of ruptured IAs were exclusively at a posterior or anterior communicating artery (PCoA/ACoA). Histopathological examination using ruptured IAs, rupture-prone IAs induced at a PCoA or ACoA, and IAs induced at an anterior cerebral artery–olfactory artery bifurcation that never ruptured revealed the formation of vasa vasorum as an event associated with rupture of IAs.CONCLUSIONSThe authors propose the contribution of a structural change in an adventitia, i.e., vasa vasorum formation, to the rupture of IAs. Findings from this study provide important insights about the pathogenesis of IAs.
Usefulness of positron emission tomography for differentiating gliomas according to the 2016 World Health Organization classification of tumors of the central nervous system
Authors: Takei Hiroaki , Shinoda Jun , Ikuta Soko , Maruyama Takashi , Muragaki Yoshihiro , Kawasaki Tomohiro , Ikegame Yuka , Okada Makoto , Ito Takeshi , Asano Yoshitaka , Yokoyama Kazutoshi , Nakayama Noriyuki , Yano Hirohito , Iwama Toru 
Published: August 2019

OBJECTIVEPositron emission tomography (PET) is important in the noninvasive diagnostic imaging of gliomas. There are many PET studies on glioma diagnosis based on the 2007 WHO classification; however, there are no studies on glioma diagnosis using the new classification (the 2016 WHO classification). Here, the authors investigated the relationship between uptake of 11C-methionine (MET), 11C-choline (CHO), and 18F-fluorodeoxyglucose (FDG) on PET imaging and isocitrate dehydrogenase (IDH) status (wild-type [IDH-wt] or mutant [IDH-mut]) in astrocytic and oligodendroglial tumors according to the 2016 WHO classification.METHODSIn total, 105 patients with newly diagnosed cerebral gliomas (6 diffuse astrocytomas [DAs] with IDH-wt, 6 DAs with IDH-mut, 7 anaplastic astrocytomas [AAs] with IDH-wt, 24 AAs with IDH-mut, 26 glioblastomas [GBMs] with IDH-wt, 5 GBMs with IDH-mut, 19 oligodendrogliomas [ODs], and 12 anaplastic oligodendrogliomas [AOs]) were included. All OD and AO patients had both IDH-mut and 1p/19q codeletion. The maximum standardized uptake value (SUV) of the tumor/mean SUV of normal cortex (T/N) ratios for MET, CHO, and FDG were calculated, and the mean T/N ratios of DA, AA, and GBM with IDH-wt and IDH-mut were compared. The diagnostic accuracy for distinguishing gliomas with IDH-wt from those with IDH-mut was assessed using receiver operating characteristic (ROC) curve analysis of the mean T/N ratios for the 3 PET tracers.RESULTSThere were significant differences in the mean T/N ratios for all 3 PET tracers between the IDH-wt and IDH-mut groups of all histological classifications (p < 0.001). Among the 27 gliomas with mean T/N ratios higher than the cutoff values for all 3 PET tracers, 23 (85.2%) were classified into the IDH-wt group using ROC analysis. In DA, there were no significant differences in the T/N ratios for MET, CHO, and FDG between the IDH-wt and IDH-mut groups. In AA, the mean T/N ratios of all 3 PET tracers in the IDH-wt group were significantly higher than those in the IDH-mut group (p < 0.01). In GBM, the mean T/N ratio in the IDH-wt group was significantly higher than that in the IDH-mut group for both MET (p = 0.034) and CHO (p = 0.01). However, there was no significant difference in the ratio for FDG.CONCLUSIONSPET imaging using MET, CHO, and FDG was suggested to be informative for preoperatively differentiating gliomas according to the 2016 WHO classification, particularly for differentiating IDH-wt and IDH-mut tumors.
Improving medical student recruitment to neurosurgery
Authors: Lubelski Daniel , Xiao Roy , Mukherjee Debraj , Ashley William W. , Witham Timothy , Brem Henry , Huang Judy , Wolfe Stacey Quintero 
Published: August 2019

OBJECTIVENeurosurgery seeks to attract the best and brightest medical students; however, there is often a lack of early exposure to the field, among other possible barriers. The authors sought to identify successful practices that can be implemented to improve medical student recruitment to neurosurgery.METHODSUnited States neurosurgery residency program directors were surveyed to determine the number of medical student rotators and medical students matching into a neurosurgery residency from their programs between 2010 and 2016. Program directors were asked about the ways their respective institutions integrated medical students into departmental clinical and research activities.RESULTSComplete responses were received from 30/110 institutions. Fifty-two percent of the institutions had neurosurgery didactic lectures for 1st- and 2nd-year medical students (MS1/2), and 87% had didactics for MS3/4. Seventy-seven percent of departments had a neurosurgery interest group, which was the most common method used to integrate medical students into the department. Other forms of outreach included formal mentorship programs (53%), lecture series (57%), and neurosurgery anatomy labs (40%). Seventy-three percent of programs provided research opportunities to medical students, and 57% indicated that the schools had a formal research requirement. On average, 3 medical students did a rotation in each neurosurgery department and 1 matched into neurosurgery each year. However, there was substantial variability among programs. Over the 2010–2016 period, the responding institutions matched as many as 4% of the graduating class into neurosurgery per year, whereas others matched 0%–1%. Departments that matched a greater (≥ 1% per year) number of medical students into neurosurgery were significantly more likely to have a neurosurgery interest group and formal research requirements. A greater percentage of high-matching programs had neurosurgery mentorship programs, lecture series, and cadaver training opportunities compared to the other institutions.CONCLUSIONSIn recent decades, the number of applicants to neurosurgery has decreased. A major deterrent may be the delayed exposure of medical students to neurosurgery. Institutions with early preclinical exposure, active neurosurgery interest groups, research opportunities, and strong mentorship recruit and match more students into neurosurgery. Implementing such initiatives on a national level may increase the number of highly qualified medical students pursuing neurosurgery.
Intraoperative acquisition of DTI in cranial neurosurgery: readout-segmented DTI versus standard single-shot DTI
Authors: Elliott Cameron A. , Danyluk Hayden , Aronyk Keith E. , Au Karolyn , Wheatley B. Matt , Gross Donald W. , Sankar Tejas , Beaulieu Christian 
Published: August 2019

OBJECTIVEDiffusion tensor imaging (DTI) tractography is commonly used in neurosurgical practice but is largely limited to the preoperative setting. This is due primarily to image degradation caused by susceptibility artifact when conventional single-shot (SS) echo-planar imaging (EPI) DTI (SS-DTI) is acquired for open cranial, surgical position intraoperative DTI (iDTI). Readout-segmented (RS) EPI DTI (RS-DTI) has been reported to reduce such artifact but has not yet been evaluated in the intraoperative MRI (iMRI) environment. The authors evaluated the performance of RS versus SS EPI for DTI of the human brain in the iMRI setting.METHODSPre- and intraoperative 3-T 3D T1-weighted and 2D multislice RS-iDTI (called RESOLVE [readout segmentation of long variable echo-trains] on the Siemens platform) and SS-iDTI images were acquired in 22 adult patients undergoing intraaxial iMRI resections for suspected low-grade glioma (14; 64%), high-grade glioma (7; 32%), or focal cortical dysplasia. Regional susceptibility artifact, anatomical deviation relative to T1-weighted imaging, and tractographic output for surgically relevant tracts were compared between iDTI sequences as well as the intraoperative tract shifts from preoperative DTI.RESULTSRS-iDTI resulted in qualitatively less regional susceptibility artifact (resection cavity, orbitofrontal and anterior temporal cortices) and mean anatomical deviation in regions most prone to susceptibility artifact (RS-iDTI 2.7 ± 0.2 vs SS-iDTI 7.5 ± 0.4 mm) compared to SS-iDTI. Although tract reconstruction success did not significantly differ by DTI method, susceptibility artifact–related tractography failure (of at least 1 surgically relevant tract) occurred for SS-iDTI in 8/22 (36%) patients, and in 5 of these 8 patients RS-iDTI permitted successful reconstruction. Among cases with successful tractography for both sequences, maximal intersequence differences were substantial (mean 9.5 ± 5.7 mm, range −27.1 to 18.7 mm).CONCLUSIONSRS EPI enables higher quality and more accurate DTI for surgically relevant tractography of major white matter tracts in intraoperative, open cranium neurosurgical applications at 3 T.
Evaluación de la calidad de los servicios hoteleros de segunda categoría del sector céntrico de Guayaquil
Authors: Zambrano Camacho Nuria , Arteaga Cisneros Janina 
Published: August 2019

La presente investigación trata de la evaluación de la calidad de los servicios en los establecimientos hoteleros de segunda categoría del sector céntrico de la ciudad de Guayaquil, con el objetivo de determinar si existen falencias en el servicio para mejorar la gestión de sus elementos tangibles e intangibles que inciden en la satisfacción de sus usuarios.De igual forma se recopilo información por medio de encuestas, lo que permitió conocer la situación actual de los hoteles de segunda categoría así como la percepción que tienen sus usuarios referentes al cumplimiento de sus expectativas y proponer planes de mejora.
Propuesta de un complejo turístico en la Parroquia Chanduy, Provincia de Santa Elena
Authors: Olivero Sánchez Félix , Montesdeoca Peralta Marlene 
Published: August 2019

La investigación tiene como objetivo proponer un complejo Turístico en Chanduy, provincia de Santa Elena. Realizado el diagnostico situacional se pudo determinar que la Parroquia Chanduy, cuenta con elementos naturales y autóctonos para atraer turismo rentable y beneficioso, generando fuentes de empleo a los comuneros, en el primer capítulo denominado estudio de mercado muestra al lector el comportamiento de los clientes potenciales, la demanda y oferta del sector económico al cual pertenece la entidad, definir las condiciones que la organización debe tener para ser competente en el mercado y la estrategia comercial, el capítulo del estudio técnico permite determinar los recursos necesarios para el desarrollo del proyecto, sus respectivos costosoperacionales y la ubicación del complejo, estudios organizacionales y legales los cuales permitirán diseñar la estructura, políticas de la empresa teniendo en cuenta los demuestra la factibilidad del proyecto utilizando indicadores financieros tales como el VAN, TIR.
Cultivo de tilapia en jaulas en la represa San Vicente de Colonche
Authors: Marín Richard Duque , Cuenca Zambrano Mayra 
Published: August 2019

La represa de San Vicente, está situada en la cuenca alta del río Javita al noroeste de la Provincia de Santa Elena. Es una represa de tierras de 25 m de altura que embalsa unos 40 Hm3que se distribuirá a través de canales para conducir el líquido vital por gravedad, favoreciendo a las comunidades ubicadas en varios sectores como: Colonche, San Marcos, Bellavista, Manantial de Guangala, Manantial de Colonche, Jambelí, Palmar, Bambil Desecho, Rio Seco, Aguadita y Cerezal, se establece que serían 26.000 las hectáreas que se beneficiarían en la provincia de Santa Elena (CEDEGÉ, 1984). La Subsecretaría de Acuacultura, junto a los representantes del Ministerio del Litoral, Ambiente y los habitantes de las diferentes comunas de la Provincia de Santa Elena, presenciaron la siembra de 120.000 de los 500.000 alevines de tilapia donados por la compañía MODERCORP que fueron sembrados en la represa de San Vicente de Colonche. (SA, 2008). Las tilapias desde que fueron sembradas crecieron y se reproducen sin control alguno, generando una densidad poblacional alta, reduciendo el espacio de traslado de estos organismos en el cuerpo de agua.Como consecuencia de aquello las tallas han disminuido, afectando la disponibilidad del recurso en tallas mayores que satisfagan a los consumidores locales. Las pocas oportunidades de trabajo en las comunidades rurales, hace que se dediquen a otras actividades que la zona les brinda, teniendo como un complemento en el sustento diario la pesca en la Represa sin predecir o prevenir los riesgos que estos representan, es así que desde las primeras capturas de tilapias no han cesado ni han planificado su sustentabilidad.
EFEK KATETER TERHADAP FUNGSI PSA SERUM SEBAGAI PREDIKTOR VOLUME PROSTAT PADA PASIEN YANG TERBUKTI BENIGN PROSTATIC HYPERPLASIA PADA PEMERIKSAAN HISTOPATOLOGIS
Authors: Tranggono Untung , Mochtar Chaidir A , Umbas Rainy 
Published: August 2019

Objective: To define the use of Prostate Specific Antigen (PSA) as a predictor of prostate volume in catheterized BPH patients. Material & methods: Data were collected from medical record of symptomatic BPH patients who underwent prostate biopsy at Cipto Mangunkusumo Hospital Urology Clinic since 1994 until 2006. Data of age, serum PSA, indwelling catheter, maximal flow, urine residue, and prostate volume were recorded as variables. Patients who had histopathological result of BPH with or without prostatitis were included; while who had prostate carcinoma, high grade prostatic intraepithelial neoplasm (HGPIN), and BPH with atypical small acinar proliferation (ASAP) were excluded. Subject were then divided into 2 groups, catheterized or not. Data were analyzed using Mann-Whitney test, analysis of variance, correlation test and linear regression test. Results: Of 2283 patients were performed prostate biopsy, 1036 patients had results of BPH with or without prostatitis, 766 patients had prostate carcinoma, while 581 patient’s biopsy result were not recorded. Of the 1036 patients, 347 were catheterized, 192 non-catheterized, and 457 were not recorded. In the catheterized group the average age were 67,04 years old, serum PSA 26,88 ng/ml, prostate volume 54,33 ml, PSA density 0,39. In non-catheterized group the average age were 66,32 years old, serum PSA 16,58 ng/ml, prostate volume 53,94 ml, PSA density 0,33. Regression test showed that serum PSA could be used as a predictor of prostate volume (F=12,830; p < 0,001); in non-catheterized group it was stronger (F=12,989; p<0,001) than in catheterized group (F=6,814; p<0,01). The accuracy of serum PSA as a prostate volume predictor based on Receiver Operating Curve (ROC) as indicated by Area Under the Curve (AUC), in the catheterized group was 0,678 - 0,725 (p<0,001); in non-catheterized group was 0,723 - 0,784 (p<0,001). Conclusion: Serum PSA could be used as a predictor of prostate volume in patients with BPH wether catheterized or not. This predictor function is stronger in non-catheterized patients. Catheter has the effect of lowering the function of serum PSA as a prostate volume predictor in patients with BPH.