121 research outputs found
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Use of the Neurological Pupil Index to Predict Postoperative Visual Function After Resection of a Tuberculum Sellae Meningioma: A Case Report.
The Neurological Pupil index (NPi) is a standardized method for evaluating pupil reactivity that removes inter-examiner variability. Changes in the NPi can predict clinical deterioration in patients with traumatic brain injury (TBI); however, its use to predict visual impairment after the resection of parasellar meningiomas has not been described. A 71-year-old female underwent a modified expanded bifrontal craniotomy for resection of a 3.1 cm tuberculum sella meningioma that caused compression of the optic chiasm and resulted in left temporal and right superior temporal visual field deficits. Postoperatively, she lost vision in the right eye. Pupillometer measurements demonstrated an asymmetrically low NPi at that time, which improved to normal prior to partial vision recovery. The average NPi in the right pupil was 1.67 during the time of vision loss compared to 3.47 in the left pupil (p=1.7x10-10). Statistical analysis was performed with the Student's t-test and the significance level was set at p-value < 0.01. Resection of parasellar meningiomas is challenging because of the proximity of the optic apparatus. We report a case of unilateral vision loss after resection of a tuberculum sella meningioma in which the impaired eye's NPi value correlated closely with visual function. NPi values that decrease below 3 predict spikes in intracranial pressure in TBI patients; similarly, increases in the NPi value above 2.5-3 predict improvement in vision in the case reported here. By monitoring the proximal portion of the oculomotor reflex, the NPi can be a marker of visual impairment after surgery
Global Monopoles in the Extended Gauss-Bonnet Gravity
We discuss self-gravitating global O(3) monopole solutions associated with
the spontaneous breaking of O(3) down to a global O(2) in an extended Gauss
Bonnet theory of gravity in (3+1)-dimensions, in the presence of a non-trivial
scalar field that couples to the Gauss-Bonnet higher curvature
combination with a coupling parameter . We obtain a range of values for
(in our notation and conventions), which are such that a global
(Israel type) matching is possible of the space time exterior to the monopole
core with a de-Sitter interior, guaranteeing the positivity of the ADM
mass of the monopole, which, together with a positive core radius ,
are both dynamically determined as a result of this matching. It should be
stressed that in the General Relativity (GR) limit, where , and
constant, such a matching yields a negative ADM monopole mass,
which might be related to the stability issues the (Barriola-Vilenkin (BV))
global monopole of GR faces. Thus, our global monopole solution, which shares
many features with the BV monopole, such as an asymptotic-space-time deficit
angle, of potential phenomenological/cosmological interest, but has, par
contrast, a positive ADM mass, has a chance of being a stable configuration,
although a detailed stability analysis is pending.Comment: 13 pages, numerical analysis on the solution added in new section IV,
further phenomenological discussion added in conclusions and outlook section.
No effect on conclusions. Version accepted for publication in Phys. Rev.
Motion of particles around a magnetically charged Euler-Heisenberg black hole with scalar hair and the Event Horizon Telescope
We study the motion of uncharged particles and photons in the background of a
magnetically charged Euler-Heisenberg (EH) black hole (BH) with scalar hair.
The spacetime can be asymptotically (A)dS or flat. After investigating particle
motions around the BH and the behavior of the effective potential of the
particle radial motion, we determine the contribution of the BH parameters to
the geodesics. Photons follow null geodesics of an effective geometry induced
by the corrections of the EH non-linear electrodynamics. Thus, after
determining the effective geometry, we calculate the shadow of the BH. Upon
comparing the theoretically calculated BH shadow with the images of the shadows
of M87* and Sgr A* obtained by the Event Horizon Telescope collaboration, we
impose constraints on the BH parameters, namely the scalar hair (), the
magnetic charge () and the EH parameter ().Comment: 38 pages, 23 figures, references adde
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Supervised machine learning algorithms demonstrate proliferation index correlates with long-term recurrence after complete resection of WHO grade I meningioma.
ObjectiveMeningiomas are the most common primary intracranial tumor, and resection is a mainstay of treatment. It is unclear what duration of imaging follow-up is reasonable for WHO grade I meningiomas undergoing complete resection. This study examined recurrence rates, timing of recurrence, and risk factors for recurrence in patients undergoing a complete resection (as defined by both postoperative MRI and intraoperative impression) of WHO grade I meningiomas.MethodsThe authors conducted a retrospective, single-center study examining recurrence risk for adult patients with a single intracranial meningioma that underwent complete resection. Uni- and multivariate nominal logistic regression and Cox proportional hazards analyses were performed to identify variables associated with recurrence and time to recurrence. Two supervised machine learning algorithms were then implemented to confirm factors within the cohort that were associated with recurrence.ResultsThe cohort consisted of 823 patients who met inclusion criteria, and 56 patients (6.8%) had recurrence on imaging follow-up. The median age of the cohort was 56 years, and 77.4% of patients were female. The median duration of head imaging follow-up for the entire cohort was 2.7 years, but for the subgroup of patients who had a recurrence, the median follow-up was 10.1 years. Estimated 1-, 5-, 10-, and 15-year recurrence-free survival rates were 99.8% (95% confidence interval [CI] 98.8%-99.9%), 91.0% (95% CI 87.7%-93.6%), 83.6% (95% CI 78.6%-87.6%), and 77.3% (95% CI 69.7%-83.4%), respectively, for the entire cohort. On multivariate analysis, MIB-1 index (odds ratio [OR] per 1% increase: 1.34, 95% CI 1.13-1.58, p = 0.0003) and follow-up duration (OR per year: 1.12, 95% CI 1.03-1.21, p = 0.012) were both associated with recurrence. Gradient-boosted decision tree and random forest analyses both identified MIB-1 index as the main factor associated with recurrence, aside from length of imaging follow-up. For tumors with an MIB-1 index < 8, recurrences were documented up to 8 years after surgery. For tumors with an MIB-1 index ≥ 8, recurrences were documented up to 12 years following surgery.ConclusionsLong-term imaging follow-up is important even after a complete resection of a meningioma. Higher MIB-1 labeling index is associated with greater risk of recurrence. Imaging screening for at least 8 years in patients with an MIB-1 index < 8 and at least 12 years for those with an MIB-1 index ≥ 8 may be needed to detect long-term recurrences
Giant sacral schwannoma: A report of six cases
Sacral and presacral schwannomas are often found incidentally, because they present with vague symptoms or symptomless. Schwannoma occurring in this area occasionally presents with enormous dimensions, known as a giant schwannoma. The tumor removal is a surgical challenge due to the difficult approach and abundant vascularity. The aim of this study is to review cases of giant sacral schwannomas focusing the surgical management and outcome. Six patients with sacral and presacral schwannoma were treated surgically. The patients included two males and four females, and the mean age was 47.8 years. All patients experienced pain at the time of presentation. The tumors were classified as intraosseous type in one case, dumb-bell type in four cases, and retroperitoneal type in one case. The tumors were removed with a piecemeal subtotal excision in three patients, a partial excision in two patients, and enucleation in one patient. The surgeries were performed by the combination of an anterior and posterior approach in three patients, a posterior approach in two patients, and an anterior approach in one patient. The mean surgical time was 7.8 hrs, and the mean blood loss was 2572 g. The tumor recurred in one patient after the partial excision and was removed completely in a second surgery. No patient, including the patient who underwent the second surgery, presented with pain and obvious neurological deficit at the final follow-up. The surgical treatment of the giant sacral schwannoma with a piecemeal subtotal excision can achieve a good outcome, avoiding unnecessary neurological deficit
Aggressive treatment of metastatic squamous cell carcinoma of the rectum to the liver: a case report and a brief review of the literature
BACKGROUND: Rectal squamous cell carcinoma (SCC) is a rare tumor. The incidence of this malignancy has been reported to be 0.25 to 1 per 1000 colorectal carcinomas. From a review of the English literature 55 cases of SCC of the rectum have been published. In this study we report a rectal metastatic SCC to the liver, discussing the efficacy of aggressive adjuvant and neo-adjuvant therapies on survival and prognosis. CASE PRESENTATION: A 39-year-old female patient with a pure SCC of the rectum diagnosed endoscopically is presented. The patient underwent initially neoadjuvant chemo-radiotherapy and then abdominoperineal resection with concomitant bilateral oophorectomy and hysterectomy, followed by adjuvant chemo-radiotherapy. Five months after the initial operation liver metastasis was demonstrated and a liver resection was carried out, followed by adjuvant chemotherapy. Eighteen months after the initial operation the patient is alive. CONCLUSION: Although prognosis of rectal SCC is worse than that of adenocarcinoma, an aggressive therapeutic approach with surgery as the primary treatment, followed by combined neo- and adjuvant chemo-radiotherapy, may be necessary in order to improve survival and prognosis
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Recurrent non-canonical histone H3 mutations in spinal cord diffuse gliomas.
The effect of ω-fatty acids on mrna expression level of PPARγ in patients with gastric adenocarcinoma
Background: The antineoplastic role of peroxisome proliferator-activated receptor gamma (PPARγ) ligandshas previously been demonstrated in several gastric cancer cell lines. Activation of PPARγ by polyunsaturated fatty acids (PUFAs) inhibits growth and proliferationof tumor cells. In this double-blind clinical study, we evaluate the effect of PUFAs on PPARγ mRNA expression in patients with gastric adenocarcinoma. Materials and Methods: A total of 34 chemotherapy-naive patients diagnosed with gastric adenocarcinoma were enrolled in the present study. According to treatment strategies, all subjects were divided into two groups, the first group (17 individuals) received cisplatin without supplements and the second group (17 individuals) received cisplatin plus orally administered PUFAs supplements for 3 weeks. The gastric biopsy samples were obtained from all participants before and after treatment, and PPARγ mRNA expression levels were evaluated by quantitative real-time polymerase chain reaction using validated reference genes. Results: Our findings revealed that PPARγ mRNA expression is significantly upregulated in group II afterreceiving cisplatin plus orally administered PUFAs supplements for three weeks (p < 0.0001), whereas PPARγ mRNA expression did not show significant alteration in group I after receiving cisplatin alone. Conclusion: The results of the study evidence that PPARγ may act as a potential target for the therapy of human gastric adenocarcinoma
Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.
PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks
Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study
PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks
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