Histopathological and biochemical changes following fat embolism with administration of corn oil micelles A NEW ANIMAL MODEL FOR FAT EMBOLISM SYNDROME
ABSTRACT Several experimental models have been used to produce intravascular fat embolism. We have developed a simple technique to induce fat embolism using corn oil emulsified with distilled water to form fatty micelles. Fat embolism was produced by intravenous administration of these fatty micelles in anaesthetised rats, causing alveolar oedema, haemorrhage and increased lung weight. Histopathological examination revealed fatty droplets and fibrin thrombi in the lung, kidney and brain. The arteriolar lumen was filled with fatty deposits. Following fat embolism, hypoxia and hypercapnia occurred. The plasma phospholipase A(2), nitrate/nitrite, methylguidanidine and proinflammatory cytokines were significantly increased. Mass spectrometry showed that the main ingredient of corn oil was oleic acid. This simple technique may be applied as a new animal model for the investigation of the mechanisms involved in the fat embolism syndrome.
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ABSTRACT: Future high-luminosity experiments make serious demands on detector technologies and have prompted a “chain” of inventions of new high-rate gaseous detectors: Microstrip Gas Counters (MSGC's), Microgap Chambers (MGC's), Compteur A Trou (CAT's), Micromesh Gas Structure (MICROMEGAS), and Gas Electron Multipliers (GEM's). We report results from a systematic study of breakdown mechanisms in these and other gaseous detectors recently chosen or considered as candidates for high-luminosity experiments. It was found that, for all the detectors tested, the maximum achievable gain before breakdown appeared, dropped dramatically with rate, sometimes inversely proportional to it. Further, in the presence of alpha particles, typical of the backgrounds in high-energy experiments, additional gain drops of 1-2 orders of magnitude were observed for some detectors. We discovered that the breakdown in these detectors was through a previously unknown mechanism for which we give a qualitative explanation. We also present possible ways of increasing the value of the maximum achievable detector gain at high rates and have verified these experimentallyIEEE Transactions on Nuclear Science 07/1999; DOI:10.1109/23.775537 · 1.46 Impact Factor
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ABSTRACT: Fat Embolism is a complication of long bone fractures, intramedullary fixation and joint arthroplasty. It may progress to fat embolism syndrome, which is rare but involves significant morbidity and can occasionally be fatal. Fat Embolism can be detected at the time of embolization by transoesophageal echocardiography or atrial blood sampling. Later, a combination of clinical signs and symptoms will point towards fat embolism but there is no specific test to confirm the diagnosis. We investigated serum Interleukin-6 (IL-6) as a possible early marker for fat embolism. An animal study was conducted to simulate a hip replacement in 31 adult male Sprague Dawley rats. The procedure was performed under general anesthesia and the animals divided into 3 groups: control, uncemented and cemented. Following surgery and recovery from anaesthesia, the rats allowed to freely mobilize in their cages. Blood was taken before surgery and at 6 hours, 12 hours and 24 hours to measure serum IL-6 levels. The rats were euthanized at 24 hours and lungs removed and stained for fat. The amount of fat seen was then correlated with serum IL-6 levels. No rats in the control group had fat emboli. Numerous fat emboli were seen in both the uncemented and cemented implant groups. The interleukin levels were raised in all groups reaching a peak at 12 hours after surgery reaching 100 pg/ml in the control group and around 250 pg/ml in the uncemented and cemented implant groups. The IL-6 levels in the control group were significantly lower than any of the implant groups at 12 and 24 hours. At these time points, the serum IL-6 correlated with the amount of fat seen on lung histology. Serum IL-6 is a possible early marker of fat embolism.Journal of Orthopaedic Surgery and Research 07/2009; 4:18. DOI:10.1186/1749-799X-4-18 · 1.58 Impact Factor
Article: Fat embolism – An update[Show abstract] [Hide abstract]
ABSTRACT: Fat embolism syndrome is an unexpected and alarming complication that is difficult to actively prevent, hard to diagnose with confidence and has limitations in effective treatment modalities. The syndrome is a melange of respiratory, haematological, neurological and cutaneous symptoms and signs associated with trauma and other disparate surgical and medical conditions. The pathogenesis is still debated. It is clear that fat emboli are quite common yet the clinical syndrome is rare. Diagnosis is by pattern recognition as befits a syndrome, but the recently defined features on MRI could now be used to increase the probability of the diagnosis. Various therapeutic options have been tried and failed. At present steroids have a single meta-analysis suggesting benefit but it is in the trauma population where they may be contra indicated for other reasons, i.e. infection, so their place is ill defined. Supportive treatment is the mainstay.Current Anaesthesia and Critical Care 10/2010; 21(s 5–6):277–281. DOI:10.1016/j.cacc.2010.03.003