Virtual reality-based exercises' effects on pulmonary functions, cardiopulmonary capacity, functional performance, and quality of life in children with repaired congenital diaphragmatic hernia.

OBJECTIVE: The long-term consequences of congenital diaphragmatic hernia (CDH), which include altered lung functions and compromised cardiopulmonary capacity, impact functional performance and quality of life. This study investigates the effects of virtual reality-based exercise programs on pulmonary functions, cardiopulmonary capacity, functional performance, and quality of life in children with repaired CDH. PATIENTS AND METHODS: A randomized controlled clinical trial was performed. Fifty-two children with repaired CDH (aged 6-10 years) were enrolled and randomly allocated to virtual reality-based exercises plus traditional physical therapy (VR-EX group, n = 26) or traditional physical therapy alone (control group, n = 26). Interventions were conducted three times a week for 12 weeks. Pulmonary functions, cardiopulmonary capacity, functional performance, and quality of life were assessed before and after the intervention. RESULTS: The VR-EX group demonstrated significantly enhanced post-treatment pulmonary functions and cardiopulmonary capacity compared to the control group after accounting for the pre-treatment values (p < 0.05). In addition, the values in functional performance and quality of life measures showed significantly larger improvements in the VR-EX group (p < 0.05). CONCLUSIONS: Children with repaired CDH may benefit more from VR-based exercises when combined with traditional physical therapy than from traditional physical therapy alone regarding their pulmonary functions, cardiopulmonary capacity, functional performance, and quality of life.

Distinct effects of trampoline-based stretch-shortening cycle exercises on muscle strength and postural control in children with Down syndrome: a randomized controlled study.

OBJECTIVE: The aim of the study was to investigate the effect of a 3-month, trampoline-based stretch-shortening cycle (SSC) exercises on muscle strength and postural control in children with Down's syndrome (DS). PATIENTS AND METHODS: Thirty-two children with DS aged between 7-9 years were enrolled and randomly assigned into the control group (n = 16); received standard physical therapy (sPT) or SSC group (n = 16); received sPT in addition to a 15-minute, trampoline-based SSC training program twice per week for 12 successive weeks. Lower limb muscle strength and postural stability [anterior/posterior stability index (A/P-SI), medial/lateral stability index (M/L-SI)], and overall stability index (O-SI) were assessed pre- and post-treatment. RESULTS: Strength of hip extensor (p=0.034) and adductor (p=0.015), knee extensor (p=0.028) and flexor (p=0.01), and ankle dorsi (p=0.033) and plantar flexor (p=0.007) muscles increased significantly in the SSC group when compared with the control group. Also, the A/P-SI (p=0.019), M/L-SI (p=0.002), and O-SI (p=0.021) decreased significantly in the SSC group when compared with the control group, suggesting better postural control. CONCLUSIONS: Twelve weeks of trampoline-based SSC exercises are likely effective for enhancing muscle strength and postural control in children with DS and should consequently be included in the rehabilitation programs for these children.

Interface morphology driven exchange interaction and magnetization reversal in a Gd/Co multilayer.

Rare-earth (RE)/transition metal (TM) ferromagnetic heterostructures with competing interfacial coupling and Zeeman energy provide a rich ground to study different phase states as a function of magnetic field and temperature. The interface morphology as a knob in these RE/TM heterostructures provides an excellent opportunity to engineer the macroscopic magnetic response by tuning the interface dependent microscopic interactions between the layers. We have investigated the interface morphology driven structure and magnetic properties of a Gd/Co multilayer. The interface morphology of the multilayer was controlled by annealing the multilayer at a relatively low temperature of 573 K under vacuum conditions. Combining the different experimental techniques and a simple one-dimensional spin-based model calculation, we studied the detailed magnetic structure and magnetization reversal mechanism in this system across compensation temperature (Tcomp), which suggested a strong interface dependent coupling in the system. We showed that changes in the interface morphology of the Gd/Co multilayer strongly influence the macroscopic magnetic properties of the system. The calculation also confirms the formation of a helical magnetic structure with a 2π domain wall in this system below Tcomp. The experimental finding and the simulation of this technologically important system will help to understand the physics of all-optical switching and related applications.

Incorporation of Pilates-based core strengthening exercises into the rehabilitation protocol for adolescents with patellofemoral pain syndrome: a randomized clinical trial.

OBJECTIVE: The objective of this study was to evaluate how a Pilates-based core strengthening exercise program affected pain, lower limb muscle strength, functional status, and health-related quality of life in adolescents with patellofemoral pain syndrome (PFPS). MATERIALS AND METHODS: In this randomized controlled clinical trial, 34 teenagers with PFPS (ages 14-17) were randomly assigned to receive either a standard PT program (control group) or Pilates exercises plus the conventional program (study group). Both groups continued the treatment sessions for 3 months (3 sessions/week). Pain intensity, lower limb muscle strength (hip abductors and external rotators and knee extensors), functional status, and health-related quality of life were evaluated pre-and post-intervention. RESULTS: Pain intensity (p =.005) reduced significantly post-treatment in the study group as compared to the control group, when controlled for the pre-treatment value. Also, muscle strength of hip abductors (p =.002) external rotators (p < .001), knee extensors (p = .013), functional status (p = .002), and health-related quality of life (p < .001) increased significantly in the study group when compared to the control group. CONCLUSIONS: The results of this study show that Pilates-based core strengthening exercises can help adolescents with PFPS reduce pain, enhance muscle strength, and improve their functional status and quality of life.

Evolution of structural and magnetic properties of FePtCu alloy films on annealing of FePt/Cu multilayers.

Thin films of ternary (FePt)100-xCux alloys were obtained by annealing of FePt (100 Å)/Cu (d Å) multilayers with d = 50 and 100 Å deposited by sputtering at room temperature on Si substrates. The evolution of structural and magnetic properties of these multilayers induced by isochronal and isothermal annealing in a vacuum has been studied using depth dependent characterization techniques. Isochronal annealing for 0.5 h at different temperatures (300 to 600 °C) showed very low interdiffusion at the interfaces with no signature of alloy phase formation. However, isothermal annealing of multilayers at 600 °C for longer times (1.5-6.5 h) showed significantly large interdiffusion accompanied by the formation of polycrystalline ternary alloy and iron silicide phases. The iron silicide formed at the substrate-film interface assists the growth of the L10 ordered ternary alloy phase, which showed different stoichiometry for different multilayers. The L10 phase formed with higher Cu content showed drastically different magnetic properties with a reduction in saturation magnetization and an increase in coercivity (∼6 kOe) at room temperature. The iron silicide formed on high temperature annealing showed ferromagnetic nature with a magnetization of ∼140 emu cm-3 at room temperature.

New insight into the diagnostic cut-off value of serum anti-Toxocara IgG for ocular toxocariasis in uveitis patients.

Uveitis is one of the commonest causes of vision loss worldwide and its exact etiology is still not clarified in most patients. The current study is a trial to assess the efficacy of serum anti-Toxocara immunoglobulin G (IgG) by enzyme-linked immunosorbent assay (ELISA) as a diagnostic tool for ocular toxocariasis (OT) and to detect OT prevalence and the associated ocular manifestations in sera of patients with uveitis. One hundred and twelve patients (62 females and 50 males) with uveitis were diagnosed by ophthalmologists, radiologists and rheumatologists according to ocular manifestations, laboratory and radiological investigations. Serum anti-Toxocara IgG titers were determined by ELISA in sera of all patients. Our results revealed that OT is highly associated with intermediate and posterior uveitis. Children and young adult females, especially those residing in rural areas, complained mainly of diminution of vision in the left eye, with strabismus and leukocoria. At a cut-off value of 0.258, the sensitivity and specificity of IgG ELISA were 93.3% and 100%, respectively. In conclusion, at a novel cut-off value of 0.258 the serum anti-Toxocara IgG ELISA is predicted to be a diagnostic tool for OT regarding sensitivity and specificity. Also, it has potential importance in the interpretation and differential diagnosis of OT. Thus, serum anti-Toxocara IgG ELISA should be a routine test for screening of suspected cases.

Interface induced magnetic properties of Gd/Co heterostructures.

Antiferromagnetic coupling between rare-earth and transition metal ferromagnetic layers gives rise to various magnetic ground states in heterostructures of these materials. Interface structure and morphology tend to play important roles in magnetic properties of such systems. Interface induced magnetization in Gd/Co heterostructures has been studied using a combination of structural and magnetic characterization techniques. The interface morphology of the Gd/Co system was varied by growing Gd/Co multilayers using magnetron sputtering under different argon partial pressures. Interfacial properties were further modified by annealing the multilayers under high vacuum. The macroscopic magnetization measurements have been correlated with depth dependent structure and magnetic properties of multilayers studied using X-ray and polarized neutron reflectometry techniques. Secondary ion mass spectrometry measurements from both as-deposited and annealed samples also confirmed modification at the interfaces. It has been shown that the interface structure, together with roughness, leads to a unique low-temperature magnetic phase characterized by twisting of Gd and Co moments.

Does MR spectroscopy of normal-appearing cervical spinal cord in patients with multiple sclerosis have diagnostic value in assessing disease progression? A prospective comparative analysis.

AIM: To clarify the role of magnetic resonance spectroscopy (MRS) in examining the normal-appearing cervical spinal cord of patients with multiple sclerosis (MS) to detect metabolite abnormalities in this disease and to assess its progression. MATERIAL AND METHODS: Thirty-six patients with MS and 30 healthy controls were enrolled. Each patient was submitted to MRS performed using a 1.5 T magnetic resonance imaging (MRI) scanner. The spectra of total N-acetyl-aspartate (tNAA), choline (Cho), creatine (Cr), and myoinositol (M-Ins), as well as the metabolite ratios of tNAA/Cr, tNAA/Cho, Cho/Cr, and M-Ins/Cr of the two groups were measured and compared. The correlations between the metabolite concentrations, disease duration, and clinical disability (expanded disability status scale, EDSS) were further explored. RESULTS: Significantly lower tNAA and higher M-Ins were observed in MS patients than in health controls. The tNAA/Cr and tNAA/Cho ratios were significantly lower in MS patients than in healthy controls. In MS patients, the EDSS was correlated with the tNAA/Cr ratio. The spinal cord cross-sectional area was significantly smaller in MS patients than in healthy controls. CONCLUSION: Reduced tNAA and increased M-Ins are important, sensitive indices for differentiating between MS patients and healthy controls. In MS patients, before lesions appear, MRS of the spinal cord may provide crucial information for assessing disease progression.

Tramadol (opioid) abuse is associated with a dose- and time-dependent poor sperm quality and hyperprolactinaemia in young men.

Tramadol, one of the most commonly abused drugs in Middle East, impacts spermatogenesis and disturbs reproductive hormones in animal studies. We aimed to investigate tramadol impact on sperm quality and on levels of testosterone, prolactin and gonadotropins, in tramadol abusers (n = 30) to age-matched control (n = 30). Abusers had significantly low percentages of sperm motility, normal forms and vitality compared with control (95% CI -40.7 to -19.3, -13.5 to -9.3 and -31.9 to -9.7 respectively). Hypoandrogenism (95% CI -4.5 to -2.8), hyperprolactinaemia (CI (95%) 4.9 to 9.4) and hypergonadotropinaemia (95% CI 2.9 to 7.2 for FSH and 2.0 to 7.8 for LH) were observed in tramadol abusers vs controls. Smokers (26 of 30), concurrently abusing other drugs (11 of 30) and asymptomatic leucocytospermic (15 of 30) patients subgroups significantly abused tramadol beyond 3 years (p = .02, <.001, = .03 respectively) and in excess >450 mg/day (p = .02, = .01, = .005 respectively). Progressive motility (a + b%) was significantly low in young men <25 years old (p = .03) subgroup. Tramadol abuse is associated with poor sperm quality, hyperprolactinaemia and hypergonadotropic hypogonadism. We recommend semen analysis for tramadol long-intakes, question sperm donors and follow-up studies to prevent and reverse tramadol-induced testicular damage.

Diagnostic value of early postoperative MRI and diffusion-weighted imaging following trans-sphenoidal resection of non-functioning pituitary macroadenomas.

AIM: To establish the value of early contrast-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) in differentiating residual pituitary adenoma from postoperative surgical changes. MATERIALS AND METHODS: Thirty patients with non-functioning pituitary macroadenomas, who were undergoing trans-sphenoidal adenomectomy, were prospectively studied. Patients were imaged with both MRI and DWI in the early postoperative period, as well as 6-months post-surgery. Patterns of postoperative contrast enhancement were described (non-enhancement, peripheral enhancement, and nodular enhancement). Apparent diffusion coefficient (ADC) maps were utilised to select the region of interest (ROI) for ADC calculations. RESULTS: Seventeen patients had postoperative surgical granulation tissue and 13 had residual adenoma based on the 6 months follow-up imaging. Mean ADC values of postoperative granulation tissue and residual adenoma were 1.476±0.476×10-3 mm2/s and 0.855±0.190×10-3 mm2/s, respectively, in the early postoperative period, and 1.357±0.416×10-3 mm2/s and 0.829±0.201×10-3 mm2/s, respectively, at the 6-month follow-up. ADC values of granulation tissue were significantly different from that of residual adenoma at both time points (p<0.001). Sensitivity, specificity, positive and negative predictive values of early MRI were 84.6%, 94.1%, 91.7%, and 88.9% respectively, and of early DWI were 91%, 97%, 94.3%, and 93%, respectively. CONCLUSION: Early postoperative DWI after trans-sphenoidal resection of pituitary macroadenomas may be more helpful than early MRI in differentiating residual adenoma from post-surgical changes.

A study of coupling interactions in finite arbitrarily-shaped grooves in electromagnetic scattering problem.

A study of coupling between finite number of general-shaped grooves in electromagnetic plane-wave scattering problem is presented. The formulation for a single groove [1] is extended to two grooves. The importance of inclusion of coupling interaction between two grooves in scattering analysis is presented and its dependence on the grooves separation distance and the angle of incident of the electromagnetic field is demonstrated quantitatively. For larger angle of incident and smaller separation distance between grooves indicate larger discrepancy between between simulation results with and without inclusion of the coupling effects. Although the results presented here considers two grooves, the formulation can be extended to arbitrary number of grooves.

Donor cerebral tissue pulmonary emboli in a functioning transplanted lung.

Cerebral tissue pulmonary embolus (CTPE) is a rare event following severe blunt or penetrating head trauma and is often complicated by coagulation disturbances and hemorrhage. Donor cerebral tissue pulmonary embolism has been reported to cause lethal, early graft dysfunction in lung transplant recipients. We report a case of donor cerebral tissue pulmonary embolism in a 41-year-old female single lung transplant recipient with excellent post-operative graft function.

Is it time to reposition vasopressors and inotropes in sepsis?

OBJECTIVES: To review the literature on the current use of vasopressors and inotropes in patients with sepsis and sepsis syndrome with respect to the choice of agent, therapeutic end points, and safe and effective doses to be used. To examine the available evidence that supports or refutes goal-directed therapy toward supranormal oxygen transport in optimizing the outcome of critically ill sepsis syndrome patients. DATA SOURCES: All pertinent English and French articles dealing with hemodynamic support with selected vasopressors and inotropic agents in human sepsis and sepsis syndrome retrieved from a computerized MEDLINE search from 1985 to 1994. STUDY SELECTION: Clinical studies with norepinephrine, epinephrine, phenylephrine, dopamine, and dobutamine in sepsis syndrome were considered if goal-directed therapy with oxygen transport variables was utilized. Emphasis was placed on prospective, randomized, controlled comparative trials. However, open-label, observational, and comparative studies, or case series, were also evaluated when limited data were available. DATA EXTRACTION: From the selected studies, information was obtained regarding patient population, dosing regimen, type of therapeutic goals or end points (hemodynamic, or normal vs. supranormal oxygen transport variables) and outcome data (e.g., achievement of goals, resolution of the episode, mortality rate, and development of end-organ dysfunction). DATA SYNTHESIS: When used in larger than usual doses, epinephrine, norepinephrine, and phenylephrine uniformly increased hemodynamic values. Epinephrine may increase oxygen transport values more reliably than norepinephrine. Dobutamine doses in the range of 2.5 to 6 microgram/kg/min increase oxygen transport variables and hemodynamics to predetermined goals in only 30% to 70% of patients. Larger infusion rates offer no further benefits. CONCLUSIONS: Insufficient evidence exists to support goal-directed therapy with vasopressors and inotropes in the treatment of sepsis syndrome. No definitive recommendations can be made about the superiority of a vasopressor or inotropic agent due to the lack of data. However, it may be that evaluation of vasopressors earlier in sepsis syndrome will yield more promising results. Large, comparative, controlled trials assessing mortality rate and development of multiple organ system dysfunction are needed.

Cytokines in the bronchoalveolar lavage fluid of patients with active pulmonary sarcoidosis.

Numerous cytokines are thought to be important in the pathogenesis of granulomatous inflammation and subsequent fibrosis in sarcoidosis. Interleukin (IL)-6 and IL-8, two recently described cytokines with a broad spectrum of proinflammatory effects, could participate in this disease. We obtained bronchoalveolar lavage fluid (BALF) from 16 subjects (13 African-American, three Caucasian) with untreated active pulmonary sarcoidosis and 10 healthy nonsmoking volunteers (nine Caucasian, one African-American). Concentrated BALF was analyzed by an ELISA for IL-6, IL-8, and albumin. The median IL-6 level was 9.8 pg/mg albumin (range, 0-278) for the sarcoid group compared with 0.14 pg/mg (range, 0.14-9.8) in the control subjects (p = 0.001). The corresponding values for IL-8 were 202 pg/mg (range, 35-2179) versus 5.0 pg/mg (range, 0-44) in the control subjects (p < 0.001). Among the sarcoid patients, BALF IL-6 and IL-8 levels correlated with each other (r = 0.96, p < 0.001), and both cytokines correlated with the BALF neutrophil percentage (r = 0.96 and 0.95, respectively; p < 0.001 for both). No difference was detected in IL-8 concentrations as measured by ELISA in culture supernatants of alveolar macrophages obtained from five sarcoid patients and five control subjects. We conclude that IL-6 and IL-8 are elevated in BALF of patients with active sarcoidosis and may be important modulators of the disease process.

Mechanism of induction of asthmatic attacks initiated by the inhalation of particles generated by airbag system deployment.

OBJECTIVE: We have previously demonstrated that inhalation of the dust produced by dual frontal airbag deployment can result in significant bronchospasm in approximately 40% of mild to moderate asthmatics. This study was performed to determine the cause of the asthmatic response. DESIGN: Controlled laboratory study. MATERIALS AND METHODS: Asthmatics who were previously tested for their response to airbag effluents were exposed for twenty minutes to either 1) airbag effluents from airbag systems in which the airbag was insulated from the hot deployment module; 2) non-sulfur containing airbag effluents; 3) sodium chloride aerosol; or 4) sodium carbonate-bicarbonate aerosol (pH 10). Pre-exposure, post-exposure, and 2 hour post exposure pulmonary spirometry and mechanics were measured. Subject's filled out symptoms questionnaires before exposure, 2, 4, 8, 12, and 19 minutes into the exposure, immediately post-exposure, and 2 hours post-exposure. MEASUREMENTS AND MAIN RESULTS: Prevention of the pyrolysis of the passenger-side bag as it rested on the hot module after deployment did not diminish the asthmatic response. Removal of sulfur-containing oxidants from the airbag pyrotechnic chemistry, which may have led to sulfite production, similarly did not alleviate the asthmatic response to the airbag effluents. Lastly, when asthmatics were exposed to sodium chloride and sodium carbonate-bicarbonate aerosols at approximately the same concentration (approximately 220 mg/m3) as the airbag aerosol concentration that occurred in the in-car tests, they had responses similar to those produced by the airbag exposures. CONCLUSIONS: We conclude that the amount of soluble particulate contained in the aerosol discharged into the passenger compartment by dual frontal airbag deployment is largely the cause of the observed evoked asthmatic attacks. The alkaline pH of the airbag and carbonate aerosols may have added an additional degree of provocation.

Bronchoalveolar lavage neutrophilia in asthmatic and healthy volunteers after controlled exposure to ozone and filtered purified air.

STUDY OBJECTIVE: To characterize the pulmonary response of asthmatic and healthy nonsmoking adult men to 0.20 ppm ozone by controlled chamber exposure. DESIGN: A prospective, crossover study of five atopic asthmatic and five normal subjects randomly exposed to ozone and filtered purified air (FPA) for 6 h, consisting of 30-min alternating periods of rest and moderate exercise. The two exposures were separated by at least 30 days. SETTING: A controlled exposure in a stainless steel chamber. PATIENTS: Five atopic asthmatic and five normal subjects between 18 and 45 years of age. Treatment with medications was withheld from asthmatics prior to the exposures. All subjects were nonsmokers. INTERVENTIONS: Symptoms were assessed throughout the exposures. Pulmonary function was measured at baseline, hourly throughout an exposure, and after an exposure. Bronchoalveolar lavage (BAL) was performed 18 h after the completion of an exposure. The BAL fluid (BALF) was analyzed for cell count and differential; the cell-free supernatant was analyzed for albumin, tumor necrosis factor (TNF), interleukin 1 (IL-1), interleukin 6 (IL-6), and interleukin 8 (IL-8). RESULTS: There were statistically significant increases in IL-8 levels, as well as percent polymorphonuclear neutrophils (PMNs) and PMNs per milliliter of lavage in asthmatics exposed to ozone as compared with the same asthmatics exposed to FPA and the same normal subjects exposed to ozone and FPA. Interleukin 6 was also significantly increased in asthmatics exposed to ozone. The BALF albumin, TNF, and IL-1 levels were not significantly different among the four groups. There were no differences between asthmatics and healthy controls exposed to ozone or FPA in baseline to postexposure FEV1, FVC, FEV1/FVC, and sRaw. CONCLUSIONS: We conclude that asthmatics exposed to ozone develop a significant BALF neutrophilia and increased levels of the cytokines, IL-8 and IL-6. These BALF findings occur even though the level of ozone exposure was not significant enough to reduce pulmonary function.

Acute pulmonary response of asthmatics to aerosols and gases generated by airbag deployment.

The purpose of this study was to determine whether the aerosols and gases that vent into an automobile's passenger compartment after airbag deployment pose a risk to the asthmatic population. After baseline pulmonary function measurements were taken, 24 diagnosed asthmatic subjects were placed in the rear seat of an automobile, and a driver-passenger airbag system was deployed. Subjects remained in the vehicle with the windows closed and no ventilation for 20 min or until they perceived or demonstrated signs of chest tightness and bronchoconstriction. They then exited the vehicle and were retested immediately after exposure and 2 and 4 h after exposure. Ten of the 24 subjects demonstrated clinically significant bronchoconstrictive episodes, three of which required medical intervention. These three events were quickly reversed by beta-agonist therapy. When eight of the responding subjects were reexposed at later dates to the same supplemental inflatable restraints emissions while wearing a high-efficiency particulate absolute respirator, which prevented inhalation of the particles but allowed passage of the gases, the pulmonary response was essentially eliminated. We conclude that the aerosols generated by deployment of automotive driver-passenger airbag systems can induce significant asthmatic reactions in some individuals.

Interleukin-8 gene expression by a pulmonary epithelial cell line. A model for cytokine networks in the lung.

Cellular constituents of the alveolar-capillary wall may be key participants in the recruitment of polymorphonuclear leukocytes to the lung through the generation of the novel neutrophil chemotactic peptide interleukin-8 (IL-8). This interaction appears to occur via the ability of human alveolar macrophage (AM)-derived monokines, tumor necrosis factor (TNF), and interleukin-1 (IL-1) to induce gene expression of IL-8 from pulmonary type II-like epithelial cells (A549). Northern blot analysis demonstrated that steady-state IL-8 mRNA expression, by either TNF- or IL-1 beta-treated A549 cells, occurred in both a dose- and time-dependent fashion. Similarly, extracellular antigenic IL-8, as assessed by specific ELISA, was expressed from TNF- or IL-1 beta-stimulated epithelial cells in a time-dependent fashion with maximal IL-8 antigen detected at 24 h poststimulation. Immunohistochemical staining utilizing rabbit anti-human IL-8 antibody identified immunoreactive, cell-associated IL-8 antigen as early as 8 h post-TNF or IL-1 beta stimulation. A549-generated neutrophil chemotactic bioactivity paralleled IL-8 steady-state mRNA levels. Signal specificity was demonstrated in this system as IL-8 mRNA or protein expression by lipopolysaccharide (LPS)-treated A549 cells was not different from unstimulated cells. Although LPS did not serve as a direct stimulus for the production of IL-8 by type II-like epithelial cells, the condition media from LPS-challenged AM induced a significant expression of IL-8 mRNA by the A549 cells. 24-h conditioned media from LPS-treated cells was as potent as either IL-1 beta or TNF in generating steady-state IL-8 mRNA by A549 cells. Preincubation of LPS-treated AM-conditioned media with anti-human TNF or IL-1 beta neutralizing antibodies resulted in significant abrogation of IL-8 gene expression by A549 pulmonary epithelial cells. These findings demonstrate potential cell-to-cell communication circuits that may be important between AMs and pulmonary epithelial cells during the recruitment phase of acute lung inflammation.

Mechanical disruption of pulmonary emboli in dogs with a flexible rotating-tip catheter (Kensey catheter).

Pulmonary embolism was induced in 11 dogs by the injection of three- to four-day-old allogeneic blood clots. The clots were made radiopaque by soaking them in contrast material. The resulting clots were firm, 3 to 4 cm long, and 1 cm in diameter. Injection of the clots into the external jugular vein consistently produced occlusion of at least one of the lobar pulmonary arteries. In every instance in which the tip of the catheter could be positioned at the clot embolus (six dogs), the clots were readily fragmented with a number 8 French (2.67 mm OD) flexible rotating tip catheter (Kensey catheter) activated at 80,000 rpm. Overall perfusion was shown by posttreatment angiograms to be markedly improved. These studies show that catheter-tip fragmentation of pulmonary emboli with a Kensey catheter has excellent potential for therapeutic application in patients with pulmonary embolism.

Host responses in mediating sepsis and adult respiratory distress syndrome.

Despite significant advances in intensive care unit technology and mechanical ventilatory support, mortality due to adult respiratory distress syndrome (ARDS) or multiorgan failure (MOF) has not changed significantly within the past two decades. The key to improving survival requires understanding and modifying (or eliminating) factors that may initiate (or modulate) these syndromes. Infection, and the host responses to infection, are major etiological factors responsible for the induction and perpetuation of the injury to the lung and microvasculature in ARDS and MOF, and contribute to late mortality. While the pathogenesis of ARDS and MOF-complicating sepsis remains to be elucidated, bacterially derived (eg, endotoxin or lipopolysaccharides [LPS]) and host-derived humoral and cellular mediators are of importance in both disease states. In fact, the host response to infection (or injurious stimuli) may be a more critical determinant of the outcome of sepsis and ARDS than the original inciting stimulus. The pleiotropic effects of LPS are largely indirect, and are orchestrated via its ability to trigger the release of an array of host-derived mediators of inflammation. Several potential mechanisms of injury in ARDS, sepsis, and MOF have been suggested and include a variety of inflammatory cells (neutrophils, mononuclear phagocytes, platelets), activated complement and coagulation components, vasoactive mediators (kinins, arachidonic acid metabolites, lipids, peptides), reactive oxygen radicals, and diverse cytokines. Interactions between these humoral and cellular mediators appear to set in motion an amplified cascade of events culminating in cellular and tissue injury. In this article, several of these putative inflammatory mediators are discussed in detail, and the importance of cytokine networking and the possible role of nonimmune cells in the orchestration of the inflammatory response associated with ARDS and MOF are explained. Finally, future therapeutic strategies aimed at blocking or suppressing the release or effects of endogenous mediators may be the key to improving the outcome of these disorders.