Synergism between platelet-activating factor-like phospholipids and peroxisome proliferator-activated receptor gamma agonists generated during low density lipoprotein oxidation that induces lipid body formation in leukocytes.
(1/34)
Oxidized low density lipoprotein (LDL) has an important proinflammatory role in atherogenesis. In this study, we investigated the ability of oxidized LDL (oxLDL) and its phospholipid components to induce lipid body formation in leukocytes. Incubation of mouse peritoneal macrophages with oxidized, but not with native LDL led to lipid body formation within 1 h. This was blocked by platelet-activating factor (PAF) receptor antagonists or by preincubation of oxLDL with rPAF acetylhydrolase. HPLC fractions of phospholipids purified from oxLDL induced calcium flux in neutrophils as well as lipid body formation in macrophages. Injection of the bioactive phospholipid fractions or butanoyl and butenoyl PAF, a phospholipid previously shown to be present in oxLDL, into the pleural cavity of mice induced lipid body formation in leukocytes recovered after 3 h. The 5-lipoxygenase and cyclooxygenase-2 colocalized within lipid bodies formed after stimulation with oxLDL, bioactive phospholipid fractions, or butanoyl and butenoyl PAF. Lipid body formation was inhibited by 5-lipoxygenase antagonists, but not by cyclooxygenase-2 inhibitors. Azelaoyl-phosphatidylcholine, a peroxisome proliferator-activated receptor-gamma agonist in oxLDL phospholipid fractions, induced formation of lipid bodies at late time points (6 h) and synergized with suboptimal concentrations of oxLDL. We conclude that lipid body formation is an important proinflammatory effect of oxLDL and that PAF-like phospholipids and peroxisome proliferator-activated receptor-gamma agonists generated during LDL oxidation are important mediators in this phenomenon. (+info)
Relation of postural vasovagal syncope to splanchnic hypervolemia in adolescents.
(2/34)
BACKGROUND: The mechanisms of simple faint remain elusive. We propose that postural fainting is related to excessive thoracic hypovolemia and splanchnic hypervolemia during orthostasis compared with healthy subjects. METHODS AND RESULTS: We studied 34 patients 12 to 22 years old referred for multiple episodes of postural faint and 11 healthy subjects. Subjects were studied in the supine position and during upright tilt to 70 degrees for 30 minutes and subgrouped into S+, historical fainters who fainted during testing (n=24); S-, historical fainters who did not faint during testing (n=10); and control subjects. Supine venous occlusion plethysmography showed no differences between blood flows of the forearm and calf in S+, S-, or control. Cardiac index, total peripheral resistance, and blood volume were not different. Using impedance plethysmography, we assessed blood redistribution during upright tilt. This demonstrated decreased thoracic blood volume and increased splanchnic, pelvic, and leg blood volumes for all subjects. However, thoracic blood volume was decreased in S+ compared with control volume, correlating well with the maximum upright heart rate. Splanchnic volume was decreased in the S+ and S- groups, correlating with the change in thoracic blood volume. Pelvic and leg volume changes were similar for all groups and uncorrelated to thoracic blood volume. CONCLUSIONS: Enhanced postural thoracic hypovolemia and splanchnic hypervolemia are associated with postural simple faint. (+info)
Thoracic penetration following mid-shaft clavicular fracture.
(3/34)
We describe a patient who sustained a widely displaced, high-energy, mid-shaft clavicular fracture in association with brachial plexus damage. The distal fragment was subsequently found to have penetrated the thoracic cavity. We describe the treatment of this rare injury with a successful outcome. (+info)
Ultrasonographic assessment of arterial cross-sectional area in the thoracic outlet on postural maneuvers measured with power Doppler ultrasonography in both asymptomatic and symptomatic populations.
(4/34)
OBJECTIVE: The purpose of this study was to evaluate the feasibility and potential usefulness of power Doppler ultrasonography (PDU) in the assessment of changes in arterial cross-sectional area in the thoracic outlet during upper limb elevation. METHODS: Forty-four volunteers and 28 patients with a clinical diagnosis of arterial thoracic outlet syndrome were evaluated by B-mode imaging and PDU. Arterial cross-sectional area was assessed in the 3 compartments of the thoracic outlet with the arm alongside the body and at 90 degrees, 130 degrees, and 170 degrees of abduction. The percentage of arterial stenosis was calculated for each of these arm positions. Nineteen of the 28 patients were also assessed by magnetic resonance (MR) imaging. RESULTS: No significant arterial stenosis was shown in the interscalene triangle and in the retropectoralis minor space of the volunteers and patients. A significant difference (P < .01) in stenosis between volunteers and patients was seen for all degrees of abduction in the costoclavicular space. The 130 degrees hyperabduction maneuver appeared to be the most discriminating postural maneuver. Seven patients assessed with MR imaging did not have any arterial stenosis on MR images, whereas an appreciable degree of arterial stenosis was shown with ultrasonography. CONCLUSIONS: Arterial compression inside the thoracic outlet can be detected and quantified with B-mode imaging in association with PDU. (+info)
Thoracic duct variations may complicate the anterior spine procedures.
(5/34)
The aim of this study is to localize and document the anatomic features of the thoracic duct and its tributaries with special emphasis on the spinal surgery point of view. The thoracic ducts were dissected from nine formaldehyde-preserved male cadavers. The drainage patterns, diameter of the thoracic duct in upper, middle and lower thoracic segments, localization of main tributaries and morphologic features of cisterna chyli were determined. The thoracic duct was detected in all cadavers. The main tributaries were concentrated at upper thoracic (between third and fifth thoracic vertebrae) and lower thoracic segments (below the level of ninth thoracic vertebra) at the right side. However, the main lymphatic tributaries were drained into the thoracic duct only in the lower thoracic area (below the level of the tenth thoracic vertebra) at the left side. Two major anatomic variations were detected in the thoracic duct. In the first case, there were two different lymphatic drainage systems. In the second case, the thoracic duct was found as bifid at two different levels. In formaldehyde preservation, the dimensions of the soft tissues may change. For that reason, the dimensions were not discussed and they may not be a guide in surgery. Additionally, our study group is quite small. Larger series may be needed to define the anatomic variations. As a conclusion, anatomic variations of the thoracic duct are numerous and must be considered to avoid complications when doing surgery. (+info)
Comparison of the ratio of upper to lower chest wall in children with spastic quadriplegic cerebral palsy and normally developed children.
(6/34)
The upper chest wall does not grow properly in children with spinal muscular atrophy (SMA) with paradoxical breathing. This suggests that long-term inability to take a deep breath in developing children may result in underdevelopment of the upper chest wall. In addition, a rapid and paradoxical breathing pattern is frequently observed in children with severe cerebral palsy (CP), which often corresponds to the underdevelopment of the upper chest wall. The present study is designed to evaluate the ratio of the upper to lower chest wall in children with severe spastic quadriplegic CP, compared with normal children. We compared normal children with children that had spastic quadriplegic CP who did not have kyphosis or scoliosis. Test subjects were matched in terms of age, height, and weight. The diameters of upper chest (D(apex)) and of lower chest (D(base)) were measured on the anteroposterior (AP) view of a chest X-ray and the D(apex) to D(base) ratio was calculated. In selected cases the forced vital capacity (FVC) was measured using a Wright Respirometer. The D(apex) to D(base) ratio was significantly lower in the CP group than in the control group (p < 0.001). The ratio increased linearly with age (p < 0.001) in both CP (R = 0.372) and control groups (R = 0.477). The FVC/preFVC showed significant correlation with the D(apex) to D(base) ratio (R = 0.542, p < 0.01). The results of this study suggest a deviation of optimal chest wall structure in children with spastic quadriplegic CP. (+info)
Lack of eosinophil peroxidase or major basic protein impairs defense against murine filarial infection.
(7/34)
Eosinophils are a hallmark of allergic diseases and helminth infection, yet direct evidence for killing of helminth parasites by their toxic granule products exists only in vitro. We investigated the in vivo roles of the eosinophil granule proteins eosinophil peroxidase (EPO) and major basic protein 1 (MBP) during infection with the rodent filaria Litomosoides sigmodontis. Mice deficient for either EPO or MBP on the 129/SvJ background developed significantly higher worm burdens than wild-type mice. Furthermore, the data indicate that EPO or MBP is involved in modulating the immune response leading to altered cytokine production during infection. Thus, in the absence of MBP, mice showed increased interleukin-10 (IL-10) production after stimulation of macrophages from the thoracic cavity where the worms reside. In addition to elevated IL-10 levels, EPO(-/-) mice displayed strongly increased amounts of the Th2 cytokine IL-5 by CD4 T cells as well as a significantly higher eosinophilia. Interestingly, a reduced ability to produce IL-4 in the knockout strains could even be seen in noninfected mice, arguing for different innate propensities to react with a Th2 response in the absence of either EPO or MBP. In conclusion, both of the eosinophil granule products MBP and EPO are part of the defense mechanism against filarial parasites. These data suggest a hitherto unknown interaction between eosinophil granule proteins, defense against filarial nematodes, and cytokine responses of macrophages and CD4 T cells. (+info)
Pulmonary function assessment in an infant with Barnes syndrome: proactive evaluation for surgical intervention.
(8/34)
Our aim for this study was to report pulmonary mechanics in a neonate with a severe case of Barnes syndrome, a rare form of thoracolaryngopelvic dysplasia, and to use these data to guide ventilatory support and serve as a presurgical screening tool. A comprehensive pulmonary function evaluation was performed on a 36-day-old patient with Barnes syndrome who was being mechanically ventilated because of severe pulmonary distress secondary to thoracic dystrophy. The measurements consisted of respiratory volumes including functional residual capacity, ventilatory mechanics including compliance and resistance, and thoracoabdominal synchrony. Chest wall compliance was 64% below normal, and the thoracoabdominal motion was indicative of predominantly abdominal displacement during inspiratory breaths. The lungs were functioning at a low functional residual capacity, resulting in low lung compliance and increased pulmonary resistance. As a result of the evaluation, the patient was recommended for lateral thoracic expansion surgery and the ventilatory management was adjusted to focus on end-distending pressure support. (+info)