Long-term frequent fires do not decrease topsoil carbon and nitrogen in an Afromontane grassland

Fire has been an integral evolutionary force shaping and maintaining grassy biomes, such as the Afromontane grasslands of South Africa. Afromontane grasslands represent a large carbon reservoir, but it is uncertain how fire affects their long-term C storage. We investigated the effect of fire regime on soil organic C and N (SOC; SON) in a long-term (39-year) burning experiment in the Maloti-Drakensberg Park, South Africa. We compared SOC and SON sampled in 2004 and 2019 from six treatments differing in fire frequency (annual, biennial, five-year, infrequent) and season (spring, autumn). Average SOC increased significantly between 2004 and 2019. Average SON increased slightly, resulting in a significant increase in C:N ratio, indicating that soil organic matter is becoming less N-eutrophic. Importantly, burning annually in spring increased SOC and SON. This unexpected response is attributed to the aluandic (acidic, high organic matter) properties of Drakensberg soils. Burning in autumn did not increase SOC and SON. The lowest C stocks were observed in infrequently burnt plots. Average C sequestration across all fire treatments was 0.30 Mg ha(-1) y(-1). The observed increase in SOC under frequent fires is contrary to many findings from other studies in grassy ecosystems and notably driven by fire season

A Systematic Review of Atypical Teratoid Rhabdoid Tumor in Adults

Background: Atypical teratoid/rhabdoid tumor in adults is a relatively rare malignant neoplasm. It is characterized by the presence of rhabdoid cells in combination with loss of either the INI1 or BRG1protein from the tumor cells.Methods: A systematic review was conducted using MEDLINE using the terms “atypical teratoid rhabdoid tumor” AND “adult.” The systematic review was supplemented with relevant articles from the references. Cases were included if the pathology was confirmed by loss of INI1 or BRG1. We included a case from our institution. The dataset was analyzed using descriptive statistics and log-rank test.Results: A total of 50 cases from 29 articles were included in this study. The average age at diagnosis was 36.7 years. The most common locations reported are the sellar region and cerebral hemispheres (without deep gray matter involvement). Of the 50 cases, 14 were reported to show evidence of dissemination. The average overall survival was 20 months. There was a significant difference in survival between the adjuvant therapy groups (p = < 0.0001).Conclusion: Atypical teratoid rhabdoid tumor of the central nervous system in adults is a rare neoplasm associated with a poor prognosis in a majority of patients. The treatment and clinical course are highly variable, and it remains unclear which factors impact prognosis

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Reoperation for Acute Hemispheric Stroke after Carotid Endarterectomy: Is There Any Value?

Abstract OBJECTIVE: Because the clinical benefit of urgent investigation and carotid rerepair for acute stroke complicating carotid endarterectomy (CEA) is uncertain, the results of this approach were examined in a large series of patients. METHODS: In a consecutive series of 700 CEAs, 24 patients (3.4%) had a postoperative stroke. Thirteen of these 24 patients experienced major hemispheric deficits (hemiplegia with or without aphasia, forced eye deviation, and decreased consciousness) that prompted either immediate surgical reexploration or cerebral angiography with reoperation on the basis of angiogram results; these 13 patients are the subject of this report. Neurological improvement was attributed to carotid reopening when affected muscle strength increased to antigravity power within 6 hours of reoperation. RESULTS: Of the 13 patients with severe postoperative deficits, 5 (38%) had the deficits when they awakened, 7 deficits occurred within 12 hours of surgery, and the only intracerebral hemorrhage in this series occurred 8 days after surgery. Five patients underwent urgent reoperation without angiography, and carotid occlusions were found and repaired in two patients. In another patient, the carotid was patent, and an intra-arterial injection of tissue plasminogen activator (20 mg) was given. In the seven patients who underwent cerebral angiography as the first step, two carotid occlusions and one residual stenosis with thrombus were found and repaired on an urgent basis. Surgical reopening of occluded arteries was followed by improvement in two of four patients, and early improvement was noted in one patient with a stenosis correction as well as in the patient who received intraoperative tissue plasminogen activator. Four patients who underwent urgent reoperation did not demonstrate a benefit soon after surgery. Two patients died, two were left with major deficits and five with moderate deficits, and four patients eventually had good recovery at a minimum of 6 months of follow-up. CONCLUSION: In this series, approximately one-half of hemispheric strokes complicating CEA had an underlying correctable lesion (occlusion or stenosis), and these patients typically had delayed-onset strokes. Approximately one-half of these patients improved early as a result of reopening, although computed tomography revealed new infarcts in most of them. Urgent carotid repair may benefit a minority of selected patients who have a major stroke after CEA