124 research outputs found
Emergency decompressive craniectomy after removal of convexity meningiomas
BACKGROUND: Convexity meningiomas are benign brain tumors that are amenable to complete surgical resection and are associated with a low complication rate. The aim of this study was to identify factors that result in acute postoperative neurological worsening after the removal of convexity meningiomas. METHODS: Clinical evaluation and neuroradiological analysis of patients who underwent removal of a supratentorial convexity meningioma were reviewed. Patients were selected when their postoperative course was complicated by acute neurological deterioration requiring decompressive craniectomy. RESULTS: Six patients (mean age: 43.3 years) underwent surgical removal of a supratentorial convexity meningioma. Brain shift (mean: 9.9 mm) was evident on preoperative imaging due to lesions of varying size and perilesional edema. At various times postoperatively, patient consciousness worsened (up to decerebrate posture) with contralateral paresis and pupillary anisocoria. Computed tomography revealed no postoperative hematoma, however, did indicate increased brain edema and ventricular shift (mean: 12 mm). Emergency decompressive craniectomy and brief ventilator assistance were performed in all patients. Ischemia of the ipsilateral posterior cerebral artery occurred in 3 patients and hydrocephalus occurred in 2 patients. Outcome was good in 2, fair in 2, 1 patient had severe disability, and 1 patient died after 8 months. CONCLUSIONS: Brain shift on preoperative imaging is a substantial risk factor for postoperative neurological worsening in young adult patients after the removal of convexity meningiomas. Emergency decompressive craniectomy must be considered because it is effective in most cases. Other than consciousness impairment, there is no reliable clinical landmark to guide the decision to perform decompressive craniectomy; however, brain ischemia may have already occurred
“Oxaliplatin plus high dose folinic acid and 5-fluoruracil i.v. bolus (OXAFAFU) versus irinotecan plus high dose folinic acid and 5-fluoruracil i.v. bolus (IRIFAFU) in patients with metastatic colorectal carcinoma: Southern Italy Cooperative Oncology Group trial 0103”
PURPOSE:
The primary end point of this phase III trial was to compare the response rate (RR) of oxaliplatin (OXA) plus levo-folinic acid (l-FA) and 5-fluorouracil (5-FU) bolus with that of irinotecan (IRI) plus l-FA and 5-FU bolus in advanced colorectal carcinoma.
PATIENTS AND METHODS:
Patients with measurable metastatic colorectal carcinoma were randomly allocated to receive: IRI 200 mg/m(2) on day 1, l-FA 250 mg/m(2) intravenously plus 5-FU 850 mg/m(2) on day 2 (IRIFAFU); or OXA 100 mg/m(2) on day 1, l-FA 250 mg/m(2) plus 5-FU 1050 mg/m(2) on day 2 [OXAFAFU high dose (hd)]. Cycles were given every 2 weeks. After a planned interim analysis, OXA was reduced to 85 mg/m(2) and 5-FU to 850 mg/m(2) [OXAFAFU low dose (ld)].
RESULTS:
Two hundred and seventy-four patients (IRIFAFU, 135; OXAFAFUhd, 71; OXAFAFUld, 68) were treated. Forty-two confirmed responses were achieved with IRIFAFU, 29 with OXAFAFUhd and 32 with OXAFAFUld. The response rate with OXAFAFU [44%; 95% confidence interval (CI) 35% to 52%] was significantly higher (P=0.029) than that of IRIFAFU (31%; 95% CI 23% to 40%). Occurrence of grade > or =3 neutropenia with OXAFAFUld was similar to that for IRIFAFU (29% versus 31%), while severe diarrhoea was significantly lower (12% versus 24%). Median failure-free survival (7 versus 5.8 months; P=0.046) and overall survival of patients (18.9 versus 15.6 months; P=0.032) were significantly prolonged with OXAFAFU.
CONCLUSIONS:
OXAFAFU was more active and less toxic than IRIFAFU, and it should be preferred in the first-line treatment of advanced colorectal cancer patients
“Randomised, open-label, phase II trial of paclitaxel, gemcitabine and cisplatin versus gemcitabine and cisplatin as first-line chemotherapy in advanced transitional cell carcinoma of the urothelium”
The purpose of the study was to evaluate the antitumor activity and the safety of paclitaxel combined with gemcitabine and cisplatin in patients affected by advanced transitional cell carcinoma of the urothelium (TCC). Eighty-five patients affected by advanced TCC and measurable disease were randomized to receive either paclitaxel at dosage of 70 mg/m2, gemcitabine 1000 mg/m2 and cisplatin 35 mg/m2 on days 1 and 8 every 3 weeks (GCP) or gemcitabine 1000 mg/m2 on days 1, 8, 15 and cisplatin 70 mg/m2 on day 2 every 4 weeks (GC). All enrolled patients were considered evaluable for response and toxicity (intention to treat). The observed response rate was 43% for GCP and 44% for GC combination, respectively. Median time to treatment failure was 32 weeks for GCP and 26 weeks for GC and overall survival 61 vs 49 weeks, respectively (p-value not significant). Grade 3-4 neutropenia was observed in 49% of patients treated with GCP vs 35% of those treated with GC (P=0.05) and grade 3-4 thrombocytopenia was observed in 36% of GCP treated patients as compared to 21% of those treated with GC (P=0.01). Seven patients over 70 years old or with poor PS were removed from the study: 6 patients from GCP group (2 toxic deaths, 2 grade 4 myelotoxicity and 2 grade 3 asthenia) and 1 from GC group was lost to follow-up after the first cycle. The combination of paclitaxel, gemcitabine and cisplatin is effective in the treatment of TCC. However, the addition of paclitaxel to the combination of gemcitabine plus cisplatin seems to increase toxicity, therefore it seems not suitable for poor PS patients and those over 70 years old. Larger and more powered studies are needed to exactly define the role of paclitaxel in this combination
A search for ultra-high-energy photons at the Pierre Auger Observatory exploiting air-shower universality
The Pierre Auger Observatory is the most sensitive detector to primary photons with energies above ∼0.2 EeV. It measures extensive air showers using a hybrid technique that combines a fluorescence detector (FD) with a ground array of particle detectors (SD). The signatures of a photon-induced air shower are a larger atmospheric depth at the shower maximum (X) and a steeper lateral distribution function, along with a lower number of muons with respect to the bulk of hadron-induced background. Using observables measured by the FD and SD, three photon searches in different energy bands are performed. In particular, between threshold energies of 1-10 EeV, a new analysis technique has been developed by combining the FD-based measurement of X with the SD signal through a parameter related to its muon content, derived from the universality of the air showers. This technique has led to a better photon/hadron separation and, consequently, to a higher search sensitivity, resulting in a tighter upper limit than before. The outcome of this new analysis is presented here, along with previous results in the energy ranges below 1 EeV and above 10 EeV. From the data collected by the Pierre Auger Observatory in about 15 years of operation, the most stringent constraints on the fraction of photons in the cosmic flux are set over almost three decades in energy
Study on multi-ELVES in the Pierre Auger Observatory
Since 2013, the four sites of the Fluorescence Detector (FD) of the Pierre Auger Observatory record ELVES with a dedicated trigger. These UV light emissions are correlated to distant lightning strikes. The length of recorded traces has been increased from 100 μs (2013), to 300 μs (2014-16), to 900 μs (2017-present), to progressively extend the observation of the light emission towards the vertical of the causative lightning and beyond. A large fraction of the observed events shows double ELVES within the time window, and, in some cases, even more complex structures are observed. The nature of the multi-ELVES is not completely understood but may be related to the different types of lightning in which they are originated. For example, it is known that Narrow Bipolar Events can produce double ELVES, and Energetic In-cloud Pulses, occurring between the main negative and upper positive charge layer of clouds, can induce double and even quadruple ELVES in the ionosphere. This report shows the seasonal and daily dependence of the time gap, amplitude ratio, and correlation between the pulse widths of the peaks in a sample of 1000+ multi-ELVES events recorded during the period 2014-20. The events have been compared with data from other satellite and ground-based sensing devices to study the correlation of their properties with lightning observables such as altitude and polarity
Extraction of the Muon Signals Recorded with the Surface Detector of the Pierre Auger Observatory Using Recurrent Neural Networks
We present a method based on the use of Recurrent Neural Networks to extract the muon component from the time traces registered with water-Cherenkov detector (WCD) stations of the Surface Detector of the Pierre Auger Observatory. The design of the WCDs does not allow to separate the contribution of muons to the time traces obtained from the WCDs from those of photons, electrons and positrons for all events. Separating the muon and electromagnetic components is crucial for the determination of the nature of the primary cosmic rays and properties of the hadronic interactions at ultra-high energies.
We trained a neural network to extract the muon and the electromagnetic components from the WCD traces using a large set of simulated air showers, with around 450 000 simulated events. For training and evaluating the performance of the neural network, simulated events with energies between 1018.5, eV and 1020 eV and zenith angles below 60 degrees were used. We also study the performance of this method on experimental data of the Pierre Auger Observatory and show that our predicted muon lateral distributions agree with the parameterizations obtained by the AGASA collaboration
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