Relationship between pulmonary fat embolism and core body temperature in rats with a severe fatty liver

We previously demonstrated that pulmonary fat embolism was induced by elevation of the core body temperature, in rats with a fatty liver. The aim of the present examination was to investigate the core body temperature at which pulmonary fat embolism developed capillaries through exposure to a high temperature, in rats with a fatty liver. Following heat stress, pulmonary fat embolism was observed to a slight degree at a core body temperature of 41 and 42 degrees C, whereas the severity of pulmonary fat embolism was greatly increased and was classified as severe at a core body temperature of 43 degrees C. Moreover, the concentrations of aspartate aminotransferase and alanine aminotransferase within plasma were significantly increased at a core body temperature of 43 degrees C. These results clearly indicate that the development of pulmonary fat embolism could be related to hyperthermia at above 42 degrees C following heat stress, and that fat emboli may be derived from the fatty liver itself. It is thus likely that pulmonary fat embolism can be considered as one form of evidence of hyperthermia in an individual with a fatty liver.     

Pulmonary fat embolization as a diagnostic finding for heat exposure

The aim of this study was to examine whether the detection of pulmonary fat embolization is valid as a significant indicator of heat exposure in forensic autopsies. In 54 cases where there was no evidence of fracture, burn or pancreatitis, 25 cases (46.3%) showed pulmonary fat embolization, the degree of which was pathohistologically classified as slight in all cases. Among the 25 cases where the pulmonary fat embolization was detected, the individual had died under a high ambient temperature in 14 cases (56%). Based on logistic regression analysis, pulmonary fat embolization was found to be associated with a high ambient temperature, but not associated with coronary arteriosclerosis, fatty infiltration in the liver, severe infectious diseases, intracranial hemorrhage or the detection of methamphetamine in the blood. Further investigations are necessary before these findings can be applied in forensic autopsy cases; however, it is likely that the detection of pulmonary fat embolization is valuable as one of the diagnostic findings indicating antemortem heat exposure.     

Fettleber und Fettembolie

We report the case of a 77-year-old woman who was admitted to hospital with a relapsed vertebral compression syndrome due to herniation of the intervetrebral disk. Death occurred 2 days after admittance to hospital and the autopsy and histology revealed sepsis originating from purulent bronchopneumonia. In addition, pulmonary fat embolism grade II-III was present and was also detectable in other organs. The pathogenesis of fat embolism is discussed in the light of the literature. In the present case, postmortem findings in conjunction with the preceding clinical course favour the concept of a hepatic origin of fat embolism due to a pre-existing, partly cystic, fatty degeneration of the liver with spread of fat emboli from congestive liver parenchyma necrosis in the course of increasing right heart insufficiency. Pulmonary fat embolism was clinically relevant and contributed to the fatal outcome.     

Pulmonary fat embolism after pelvic and long bone fractures in a trauma patient

Fat embolism is a common complication of pelvic and long bone fractures. Macroscopic fat emboli in the pulmonary arteries on computed tomography have been reported postoperatively after fixation of long bone fractures for trauma, however the quantification of attenuation values of fat emboli have been infrequently reported in the literature. We present a case of pulmonary fat embolism in a 52-year-old female after acute bony trauma sustained during a motor vehicle accident. To the authors' knowledge however, pulmonary fat embolism has not been described on the initial trauma CT scan.     

A case of sudden death by decidual cell embolism

Summary A 35-year-old multipara died suddenly of a pulmonary embolism about 12h after delivery. The morphological features and the entry site of the emboli into the circulation suggested that they were decidual cells. Intact decidual cells accounted for only a minority of the emboli: the great majority were cells that had lost their nuclei and/or had been fragmented. The presence of embolized areas, accompanied by fibroblasts and newly formed capillaries, suggested that the embolization process had started before the beginning of labor. However, no symptoms suggesting embolism had been recorded on the clinical chart.     

Fat embolism syndrome

The fat embolism syndrome is clinically evident in approximately 0.5-2.0% of patients with long bone fractures. The clinical signs and symptoms are evident in 60% of patients within 24 hours and 85% of patients within 48 hours after trauma. A patient is reported who complained of dyspnea and hemoptysis approximately 72 hours after sustaining a fracture to the distal tibia and fibula. Radionuclide ventilation/perfusion imaging was obtained to rule out pulmonary thromboemboli. Perfusion imaging demonstrated the characteristic diffuse, subsegmental ("mottled") appearance of fatty emboli to the lung.     

CT of pulmonary thromboembolic disease

A good quality CT pulmonary angiogram has a high accuracy rate for the evaluation of pulmonary embolism. Investigators have reported that the subsegmental emboli can be missed; however, visualization of smaller arterial branches, and therefore, detection of small emboli may improve with the availability of multidetector scanners. Some of the advantages of using CT for pulmonary embolism compared with lung scintigraphy include: (1) direct visualization of emboli on CT, (2) evaluation of lung parenchyma and mediastinum, which may provide an alternate diagnosis, and (3) capability to acquire CT venogram without additional contrast with "one-stop examination" for evaluation of thromboembolic disease.     

长期游泳训练和补充大豆多肽对高脂饮食大鼠脂肪肝形成过程中脂代谢的影响

目的:研究长期游泳训练和补充大豆多肽对高脂饮食大鼠脂肪肝形成的干预作用及其机制。方法:雄性SD大鼠60只,随机分为C组(普通饲料对照组)、HF组(高脂饮食组)、HE组(高脂饮食 运动组)、HS组(高脂饮食 大豆多肽组)、HES组(高脂饮食 运动 大豆多肽组)5组,HE组和HES组大鼠进行每周6次、每次60min的无负重游泳训练,HS组和HES组大鼠按500mg/kgBW的剂量补充大豆多肽。10周后观察大鼠肝脏的形态结构,并检测大鼠血清甘油三酯(TG)、总胆固醇(TC)和肝内TG、TC以及游离脂肪酸(FFA)含量。结果:(1)HF组大鼠肝脏出现严重的大泡性脂肪变性,并有不同程度的炎性细胞浸润,且血清TG(P<0.05)、TC(P<0.01)和肝内TG(P<0.05)、TC(P<0.01)以及FFA(P<0.01)含量显著高于对照组。(2)与HF组相比,HE、HS和HES组大鼠肝脂肪变性显著减轻。双因素方差分析表明,有氧游泳训练使高脂饮食大鼠肝TG、TC含量虽有降低,但不显著;而使血清TG(P<0.01)、TC(P<0.01)以及肝FFA含量(P<0.01)显著降低。补充大豆多肽可使高脂饮食大鼠血清、肝TG、TC以及肝内FFA含量(P<0.01)显著降低。有氧游泳训练联合补充大豆多肽对降低高脂饮食大鼠血清TG(P<0.01)、TC(P<0.05)和肝TG(P<0.01)、TC(P<0.01)、FFA(P<0.01)含量具有显著的交互作用。结论:(1)10周的高脂饮食可以诱导大鼠脂肪肝的形成,且与脂肪代谢紊乱有关。(2)有氧运动和补充大豆多肽可通过改善高脂饮食大鼠的脂肪代谢预防脂肪肝的形成。     

Pulmonary fat embolism: common and unusual computed tomography findings

Fat embolism syndrome (FES) is a common complication of fractures, usually of the long bones and pelvis. Common computed tomography findings of pulmonary FES include areas of consolidation, ground-glass opacities, and small nodules of various sizes, whereas filling defects in pulmonary arteries are rarely described in nonfulminant syndromes. We present an unusual case of nonfulminant pulmonary FES in which computed tomography disclosed multiple macroscopic pulmonary fat emboli associated to diffuse ground-glass attenuation in both lungs.     

Pulmonary embolism after hip or knee replacement: postoperative changes on pulmonary scintigrams in asymptomatic patients

Serial pulmonary imaging has proved to be effective in the evaluation of patients undergoing total joint arthroplasty. A clinical dilemma arises in asymptomatic patients whose postoperative pulmonary images differ from the preoperative images. The authors prospectively evaluated 403 patients with serial imaging to determine the significance of changed postoperative images in asymptomatic patients undergoing total hip or knee arthroplasty. Twenty-two (5.5%) patients had significant changes on postoperative images. Seventeen were asymptomatic; all but one underwent pulmonary angiography. Documented pulmonary emboli were demonstrated in 100% of patients whose postoperative images changed to indicate a high probability of pulmonary embolism, 71% whose images changed to a moderate probability, and 0% whose images changed to indeterminate probability. Overall, pulmonary emboli occurred in 76% of all asymptomatic patients with significantly change postoperative images. Asymptomatic pulmonary embolism is a significant occurrence after total hip or knee repair, and a changed lung scan with appropriate clinical evaluation is an accurate indicator of pulmonary emboli in asymptomatic postarthroplasty patients.     

Experimental pulmonary fat embolism induced by injection of triolein in rats

The relationship between the volume of fat flowing in the bloodstream and the degree of pulmonary fat embolism has remained unclear. In this study, in order to examine whether the volume of fat particles in the bloodstream could be estimated from the degree of pulmonary fat embolism, 0.05, 0.1, 0.15, 0.2 and 0.25 ml of triolein were injected into male rats weighing 300-320 g, through the caudal vein. Consequently, it was noted that the severity of pulmonary fat embolism tended to gradually increase in proportion to the volume of injected triolein, with the severity of pulmonary fat embolism being significantly augmented by the injection of 0.2 and 0.25 ml of triolein, based on morphometric analysis. In application to human cases, about 60 ml of fat particles was estimated to flow into the bloodstream after the occurrence of a pelvic fracture. Moreover, the results of this study led to the hypothesis that the prognosis of pulmonary fat embolism is affected by the severity of preceding conditions which have caused fat embolism.     

Osmium impregnation detection of pulmonary intravascular fat in sudden death: A study of 65 cases

Pulmonary fat embolism is widely recognised in forensic pathology. Pulmonary fat embolism requires mobilisation of free fat, entry of free fat into the circulation and lodging of fat globules in fine venous capillaries. This paradigm of fat embolisation has been used to support the evidence of antemortem fat depot disruption when the presence of intravascular fat is confirmed at autopsy. However, sporadic reports of intravascular fat in various medical conditions, which contradict the above mechanism, have opened questions about the alternative pathogenesis. In this study, 65 cases of sudden deaths were examined for the presence of pulmonary intravascular fat (PIF) by osmium impregnation. Cases were selected based on the criteria that were designed to eliminate the possible confounding effect from medical intervention or postmortem changes. Slides were graded based on their ease of search and only the fat droplets confined by the blood vessel or capillary wall were considered as a positive finding. The results show surprisingly high PIF incidences of varying degrees in all the categories of sudden deaths. Further study is needed to devise criteria for diagnosis of fatal fat embolism since the histological appearance of the high-grade PIF in natural sudden death may not be easily distinguishable from the traumatic fat embolism.     

高糖高脂肪饲料诱导大鼠非酒精性脂肪肝模型的动态研究

目的观察非酒精性脂肪肝的形成过程和停止造模后自然愈合情况。方法用高糖高脂肪饲料喂养大鼠30 d后改为标准鼠料喂养。分别于实验10、20、30、40、50、60 d时观察血清、肝脏生化指标及组织病理学。结果大鼠血清中甘油三脂（TG）、总胆固醇（TC）含量和谷丙转氨酶（ALT）、谷草转氨酶（AST）于实验10 d时明显升高;肝脏中TG、TC于实验10 d时明显升高,丙二醛（MDA）于实验20 d时明显升高,同时超氧化物岐化酶（SOD）活力显著降低,到实验结束时,所有指标与正常大鼠存在明显差异。肝脏组织病理学观察可见随着造模时间的延长,肝细胞脂肪变程度加重,在实验30 d时,肝细胞脂肪变程度严重,伴肝细胞点状及片状坏死,为重度脂肪肝,停止造模30 d内肝脏自然愈合在组织病理学上不明显。结论用高糖高脂肪饲料喂养大鼠30 d成功建立非酒精性脂肪肝模型,停止造模后,该模型在30 d内稳定,可用于抗脂肪肝药物的筛选及药效实验。     

An autopsy case of massive pulmonary tumor embolism due to undiagnosed prostatic adenocarcinoma

Adenocarcinoma of the prostate is occasionally associated with pulmonary embolism, occurring as a result of secondary hypercoagulable states or cancer-associated emboli. The objective of this study was to provide a review of clinical, histopathological and immunohistochemical features of poorly differentiated prostatic adenocarcinoma, emphasizing the relevance of undiagnosed malignancy as a cause of pulmonary embolism. The current study describes the case of a 78-year-old male who experienced remarkable clinical symptoms suggestive of pulmonary embolism. Following several diagnostic examinations, the patient was diagnosed with pulmonary embolism, which led to the detection of prostatic adenocarcinoma. Poorly differentiated adenocarcinoma with a Gleason’s score of nine was set as a definite diagnosis. Multiple tumor emboli within small and medium-sized pulmonary blood vessels were found in all specimens taken from lung tissue. Immunohistochemical analysis showed diffuse and strong positivity of tumor cells within pulmonary arteries. Hidden malignancy is a diagnostic challenge that should be considered in the differential diagnosis of pulmonary embolism. Laboratory and radiological findings with additional histopathological evaluation are needed for the definite diagnosis.     

Chronic pulmonary embolism in children

Chronic pulmonary embolism with pulmonary hypertension in children is rarely diagnosed clinically; literature review yielded only 17 recorded cases. To demonstrate the radiographic features as well as to encourage the diagnostic consideration of chronic pulmonary embolism in children, this report focuses on three additional children with chronic pulmonary embolism. Of these 20 total cases, only two were not catheter-related; 17 patients had emboli as a complication of ventriculoatrial shunting, and one had emboli secondary to indwelling venous hyperalimentation. Analysis of the information available on the 20 cases revealed the following radiographic features: cardiomegaly (19 cases), large central pulmonary arteries with rapid distal tapering (15 cases), oligemia (five cases), "infiltrate" (three cases), and effusion (two cases). With increasing use of central catheterization as treatment for children with chronic illness, the incidence of chronic pulmonary embolism will likely increase; therefore, clinical diagnosis should reflect this increase. The radiologist in particular should be aware of the clinical and radiologic features of chronic pulmonary embolism in children.     

Acute pulmonary embolism: diagnosis with MR angiography

PURPOSE: To prospectively evaluate pulmonary magnetic (MR) angiography as a diagnostic examination for acute pulmonary embolism (PE). MATERIALS AND METHODS: Thirty-six consecutive patients (19 women, 17 men; age range, 28-84 years) underwent pulmonary digital subtraction angiography (DSA) and pulmonary MR angiography. MR angiograms were obtained during suspended respiration and the pulmonary arterial phase of gadolinium-based contrast medium injection. A steady-state gradient-recalled-echo sequence with free induction decay sampling was used. DSA studies were interpreted for the presence of acute PE by two independent radiologists; an adjudicator made the final decision on discordant interpretations. RESULTS: By using DSA, a total of 19 acute pulmonary emboli were depicted in 13 patients. Prospectively, 13 of these emboli were depicted by using MR angiography. MR angiography missed six emboli: Four required the DSA adjudicator to make the decision, and one was in a patient whose MR angiogram was acquired during breathing. Four of these six emboli were small subsegmental emboli, and two were segmental. CONCLUSION: Performed without pulmonary arterial catheterization, iodinated contrast media, or ionizing radiation, pulmonary MR angiography had a high accuracy for depicting lobar and segmental emboli, but was unable to depict four of five subsegmental emboli.     

How I do it: CT pulmonary angiography

OBJECTIVE: The purpose of this article is to describe the techniques to improve motion artifacts, vascular enhancement, flow artifacts, body habitus image noise, vascular opacification in parenchymal lung disease, streak artifacts, and the indeterminate CT pulmonary angiogram. In addition, this article will illustrate the diagnostic criteria of acute and chronic pulmonary emboli. CONCLUSION: Pulmonary embolism is the third most common acute cardiovascular disease, after myocardial infarction and stroke, and it leads to thousands of deaths each year because it often goes undetected. For the more than 25 years that the direct signs of pulmonary embolism have been available to the radiologist on CT, this noninvasive technique has produced a paradigm shift that has raised the standard of care for patients with this disease.     

大鼠高原红细胞增多症疾病模型肺肾的电镜观察

目的与方法：为了对高红症发病机理进行深入的研究和筛选防治高红症的新药，我们以低氧、高寒、口服氯化钻等复合因素复制了大鼠高红疟疾病模型。本文报道高红症大鼠肺与肾脏超微结构的形态学研究；结果：大鼠肺泡腔内见有血浆蛋白渗出，肺泡毛细血管基膜受损；肾小球毛细血管基膜呈板层样改变，且于肾小球毛细血管腔内见有红血球堆积；结果：急性缺氧时大鼠的肺与肾脏均出现明显的缺氧性损害；结论：本研究为大鼠高红症疾病模型的建立提供了形态学依据。     

Spiral CT of pulmonary embolism: diagnostic approach, interpretive pitfalls and current indications

The introduction of spiral CT has recently modified the diagnostic work-up of pulmonary embolism, because it is possible to depict noninvasively endoluminal clots in second- to-fourth-division pulmonary arteries. If this technique is currently considered a powerful imaging alternative for the detection of acute central emboli, it is mainly related to the possibility to obtain a uniform and high degree of arterial enhancement of pulmonary arteries down to 2–3 mm in diameter. Minimal experience in spiral CT angiography is necessary to achieve this goal and requires familiarity with both data acquisition and contrast medium injection. Numerous interpretive pitfalls exist in assessing spiral CT images, and certain caveats have to be heeded. However, their recognition becomes increasingly less problematic as the radiologist gains experience with spiral CT of the pulmonary vasculature. Therefore, the purpose of this article is to review the diagnostic approach to pulmonary embolism with spiral CT, with special emphasis on protocol parameters and scan interpretation. Received 21 January 1998; Accepted 4 February 1998     

肺栓塞的螺旋CT诊断(附15例分析)

目的:探讨螺旋CT对肺栓塞的诊断价值。方法:回顾性分析15例肺栓塞患者CT平扫及增强扫描表现。结果:15例平扫显示片状实变影、磨玻璃影、楔型影、“马赛克”征等。增强扫描中央型肺栓塞12例,周围型肺栓塞3例;中央肺动脉扩张10例;右心室增大7例;支气管动脉显示15例,其中扩张6例;支气管静脉显示并扩张1例;根据肺动脉内栓子形态分4类。结论:CT对肺动脉栓塞具有较高的诊断价值。