260 research outputs found
Myocardial Infarction After General Anesthesia
Few statistics are available about the incidence of primary or recurrent myocardial infarction after anesthesia. Mortality rates and their relation to age and sex, and to type and duration of anesthesia in existing reports, are based on a relatively small number of cases. This review attempts to provide additional data on these questions by analyzing a 2-year experience in a large anesthetic practice
Highly dynamic marine redox state through the Cambrian explosion highlighted by authigenic δ²³⁸U records
The history of oceanic oxygenation from the late Neoproterozoic to the early Cambrian is currently debated, making it difficult to gauge whether, and to what extent environmental triggers played a role in shaping the trajectory of metazoan diversification. Uranium isotope (U) records from carbonates have recently been used to argue for significant swings in the global marine redox state from the late Neoproterozoic to the early Cambrian. However, geochemical signatures in carbonates—the U isotope archive most commonly employed to argue for redox shifts—are susceptible to diagenetic alteration and may have variable offsets from seawater values. Therefore, there is an impetus to reconstruct seawater U isotopic evolution using another sedimentary archive, in order to verify that these excursions can indeed be linked to global shifts in marine redox landscape. Here we report new U isotope data from two fine-grained siliciclastic upper Ediacaran to lower Cambrian (ca. 551–515 Ma) successions in South China. We find large δ²³⁸U swings between -0.63‰ and +0.39‰ for calculated values of authigenic U in the siliciclastic rocks, consistent with correlative records from the carbonates. The replication of these patterns in both carbonate and siliciclastic units provides confirmatory evidence that the early Cambrian seawater was characterized by highly variable U isotope compositions. These new δ²³⁸U data also provide higher-resolution records of global oceanic redox conditions during Cambrian Age 3, coeval with a critical interval of the Cambrian explosion. These δ²³⁸U data bolster the case that the Ediacaran-Cambrian transition experienced massive swings in marine redox state, providing a dynamic environmental backdrop for and potentially even a key driver of the emergence and radiation of metazoans
Role of cellular senescence and NOX4-mediated oxidative stress in systemic sclerosis pathogenesis.
Systemic sclerosis (SSc) is a systemic autoimmune disease characterized by progressive fibrosis of skin and numerous internal organs and a severe fibroproliferative vasculopathy resulting frequently in severe disability and high mortality. Although the etiology of SSc is unknown and the detailed mechanisms responsible for the fibrotic process have not been fully elucidated, one important observation from a large US population study was the demonstration of a late onset of SSc with a peak incidence between 45 and 54 years of age in African-American females and between 65 and 74 years of age in white females. Although it is not appropriate to consider SSc as a disease of aging, the possibility that senescence changes in the cellular elements involved in its pathogenesis may play a role has not been thoroughly examined. The process of cellular senescence is extremely complex, and the mechanisms, molecular events, and signaling pathways involved have not been fully elucidated; however, there is strong evidence to support the concept that oxidative stress caused by the excessive generation of reactive oxygen species may be one important mechanism involved. On the other hand, numerous studies have implicated oxidative stress in SSc pathogenesis, thus, suggesting a plausible mechanism in which excessive oxidative stress induces cellular senescence and that the molecular events associated with this complex process play an important role in the fibrotic and fibroproliferative vasculopathy characteristic of SSc. Here, recent studies examining the role of cellular senescence and of oxidative stress in SSc pathogenesis will be reviewed
Reliability and validity of ultrasound imaging of features of knee osteoarthritis in the community
<p>Abstract</p> <p>Background</p> <p>Radiographs are the main outcome measure in epidemiological studies of osteoarthritis (OA). Ultrasound imaging has unique advantages in that it involves no ionising radiation, is easy to use and visualises soft tissue structures. Our objective was to measure the inter-rater reliability and validity of ultrasound imaging in the detection of features of knee OA.</p> <p>Methods</p> <p>Eighteen participants from a community cohort, had both knees scanned by two trained musculoskeletal sonographers, up to six weeks apart. Inter-rater reliability for osteophytes, effusion size and cartilage thickness was calculated by estimating Kappa (κ) and Intraclass correlation coefficients (ICC), as appropriate. A measure of construct validity was determined by estimating κ between the two imaging modalities in the detection of osteophytes.</p> <p>Results</p> <p><it>Reliability: </it>κ for osteophyte presence was 0.77(right femur), 0.65(left femur) and 0.88 for both tibia. ICCs for effusion size were 0.70(right) and 0.85(left). Moderate to substantial agreement was found in cartilage thickness measurements. <it>Validity: </it>For osteophytes, κ was moderate to excellent at 0.52(right) and 0.75(left).</p> <p>Conclusion</p> <p>Substantial to excellent agreement was found between ultrasound observers for the presence of osteophytes and measurement of effusion size; it was moderate to substantial for femoral cartilage thickness. Moderate to substantial agreement was observed between ultrasound and radiographs for osteophyte presence.</p
Association between ultrasound-detected synovitis and knee pain: a population-based case-control study with both cross-sectional and follow-up data
Background: Recently an important role for synovial pathology in the initiation and progression of knee osteoarthritis (OA) has been emphasised. This study aimed to examine whether ultrasonographydetected synovial changes (USSCs) associate with knee pain (KP) in a community population.
Methods: A case-control study was conducted to compare people with early KP (n=298), established KP (n=100) or no KP (n=94) at baseline. Multinomial logistic regression was used to estimate odds ratio (OR) and 95% confidence interval (CI) between groups adjusted for radiographic osteoarthritis (ROA) severity and other confounding factors. After one year 255 participants with early and established KP completed the followup questionnaire for changes in KP. Logistic regression with adjustment was used to determine predictors of KP worsening.
Results: At baseline, effusion was associated with early (OR 2.64, 95%CI 1.57 to 4.45) and established KP (OR 5.07, 95%CI 2.74 to 9.38). Synovial hypertrophy was also associated with early (OR 5.43, 95%CI 2.12 to 13.92) and established KP (OR 13.27, 95%CI 4.97 to 35.43). The association with effusion diminished when adjusted for ROA. Power Doppler signal was uncommon (early KP 3%, established KP 2%, controls 0%). Baseline effusion predicted worsening of knee pain at one year (OR 1.95, 95% CI 1.05 to 3.64). However, after adjusting for ROA, the prediction was insignificant (aORs 0.95, 95%CI 0.44 to 2.02).
Conclusion: US effusion and synovial hypertrophy are associated with KP, but only effusion predicts KP worsening. However, the association/prediction are not independent from ROA. Power Doppler signal is uncommon in people with KP. Further study is needed to understand whether synovitis is directly involved in different types of KP
Peritoneal changes due to laparoscopic surgery
Item does not contain fulltextBACKGROUND: Laparoscopic surgery has been incorporated into common surgical practice. The peritoneum is an organ with various biologic functions that may be affected in different ways by laparoscopic and open techniques. Clinically, these alterations may be important in issues such as peritoneal metastasis and adhesion formation. METHODS: A literature search using the Pubmed and Cochrane databases identified articles focusing on the key issues of laparoscopy, peritoneum, inflammation, morphology, immunology, and fibrinolysis. Results : Laparoscopic surgery induces alterations in the peritoneal integrity and causes local acidosis, probably due to peritoneal hypoxia. The local immune system and inflammation are modulated by a pneumoperitoneum. Additionally, the peritoneal plasmin system is inhibited, leading to peritoneal hypofibrinolysis. CONCLUSION: Similar to open surgery, laparoscopic surgery affects both the integrity and biology of the peritoneum. These observations may have implications for various clinical conditions.1 januari 201
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