Neurally adjusted ventilatory assist decreases ventilator-induced lung injury and non-pulmonary organ dysfunction in rabbits with acute lung injury

OBJECTIVE: To determine if neurally adjusted ventilatory assist (NAVA) that delivers pressure in proportion to diaphragm electrical activity is as protective to acutely injured lungs (ALI) and non-pulmonary organs as volume controlled (VC), low tidal volume (Vt), high positive end-expiratory pressure (PEEP) ventilation. DESIGN: Prospective, randomized, laboratory animal study. SUBJECTS: Twenty-seven male New Zealand white rabbits. INTERVENTIONS: Anesthetized rabbits with hydrochloric acid-induced ALI were randomized (n = 9 per group) to 5.5 h NAVA (non-paralyzed), VC (paralyzed; Vt 6-ml/kg), or VC (paralyzed; Vt 15-ml/kg). PEEP was adjusted to hemodynamic goals in NAVA and VC6-ml/kg, and was 1 cmH2O in VC15-ml/kg. MEASUREMENTS AND MAIN RESULTS: PaO2/FiO2; lung wet-to-dry ratio; lung histology; interleukin-8 (IL-8) concentrations in broncho-alveolar-lavage (BAL) fluid, plasma, and non-pulmonary organs; plasminogen activator inhibitor type-1 and tissue factor in BAL fluid and plasma; non-pulmonary organ apoptosis rate; creatinine clearance; echocardiography. PEEP was similar in NAVA and VC6-ml/kg. During NAVA, Vt was lower (3.1 +/- 0.9 ml/kg), whereas PaO2/ FiO2, respiratory rate, and PaCO2 were higher compared to VC6-ml/kg (p<0.05 for all). Variables assessing ventilator-induced lung injury (VILI), IL-8 levels, non-pulmonary organ apoptosis rate, and kidney as well as cardiac performance were similar in NAVA compared to VC6-ml/kg. VILI and non-pulmonary organ dysfunction was attenuated in both groups compared to VC15-ml/kg. CONCLUSIONS: In anesthetized rabbits with early experimental ALI, NAVA is as effective as VC6-ml/kg in preventing VILI, in attenuating excessive systemic and remote organ inflammation, and in preserving cardiac and kidney function.

Five-year results evaluating the effects of platelet-rich plasma on the healing of intrabony defects treated with enamel matrix derivative and natural bone mineral

BACKGROUND Regenerative periodontal surgery using the combination of enamel matrix derivative (EMD) and natural bone mineral (NBM) with and without addition of platelet-rich plasma (PRP) has been shown to result in substantial clinical improvements, but the long-term effects of this combination are unknown. METHODS The goal of this study was to evaluate the long-term (5-year) outcomes after regenerative surgery of deep intrabony defects with either EMD + NBM + PRP or EMD + NBM. Twenty-four patients were included. In each patient, one intrabony defect was randomly treated with either EMD + NBM + PRP or EMD + NBM. Clinical parameters were evaluated at baseline and 1 and 5 years after treatment. The primary outcome variable was clinical attachment level (CAL). RESULTS The sites treated with EMD + NBM + PRP demonstrated a mean CAL change from 10.5 ± 1.6 to 6.0 ± 1.7 mm (P <0.001) at 1 year and 6.2 ± 1.5 mm (P <0.001) at 5 years. EMD + NBM-treated defects showed a mean CAL change from 10.6 ± 1.7 to 6.1 ± 1.5 mm (P <0.001) at 1 year and 6.3 ± 1.4 mm (P <0.001) at 5 years. At 1 year, a CAL gain of ≥4 mm was measured in 83% (10 of 12) of the defects treated with EMD + NBM + PRP and in 100% (all 12) of the defects treated with EMD + NBM. Compared to baseline, in both groups at 5 years, a CAL gain of ≥4 mm was measured in 75% (nine of 12 in each group) of the defects. Four sites in the EMD + PRP + NBM group lost 1 mm of the CAL gained at 1 year. In the EMD + NBM group, one defect lost 2 mm and four other defects lost 1 mm of the CAL gained at 1 year. No statistically significant differences in any of the investigated parameters were observed between the two groups. CONCLUSIONS Within their limits, the present results indicate that: 1) the clinical outcomes obtained with both treatments can be maintained up to a period of 5 years; and 2) the use of PRP does not appear to improve the results obtained with EMD + NBM.

Clustering of HCV coinfections on HIV phylogeny indicates domestic and sexual transmission of HCV

BACKGROUND: HCV coinfection remains a major cause of morbidity and mortality among HIV-infected individuals and its incidence has increased dramatically in HIV-infected men who have sex with men(MSM). METHODS: Hepatitis C virus (HCV) coinfection in the Swiss HIV Cohort Study(SHCS) was studied by combining clinical data with HIV-1 pol-sequences from the SHCS Drug Resistance Database(DRDB). We inferred maximum-likelihood phylogenetic trees, determined Swiss HIV-transmission pairs as monophyletic patient pairs, and then considered the distribution of HCV on those pairs. RESULTS: Among the 9748 patients in the SHCS-DRDB with known HCV status, 2768(28%) were HCV-positive. Focusing on subtype B(7644 patients), we identified 1555 potential HIV-1 transmission pairs. There, we found that, even after controlling for transmission group, calendar year, age and sex, the odds for an HCV coinfection were increased by an odds ratio (OR) of 3.2 [95% confidence interval (CI) 2.2, 4.7) if a patient clustered with another HCV-positive case. This strong association persisted if transmission groups of intravenous drug users (IDUs), MSMs and heterosexuals (HETs) were considered separately(in all cases OR >2). Finally we found that HCV incidence was increased by a hazard ratio of 2.1 (1.1, 3.8) for individuals paired with an HCV-positive partner. CONCLUSIONS: Patients whose HIV virus is closely related to the HIV virus of HIV/HCV-coinfected patients have a higher risk for carrying or acquiring HCV themselves. This indicates the occurrence of domestic and sexual HCV transmission and allows the identification of patients with a high HCV-infection risk.

Risk of very early recurrent cerebrovascular events in symptomatic carotid artery stenosis

OBJECT The risk of recurrence of cerebrovascular events within the first 72 hours of admission in patients hospitalized with symptomatic carotid artery (CA) stenoses and the risks and benefits of emergency CA intervention within the first hours after the onset of symptoms are not well known. Therefore, the authors aimed to assess (1) the ipsilateral recurrence rate within 72 hours of admission, in the period from 72 hours to 7 days, and after 7 days in patients presenting with nondisabling stroke, transient ischemic attack (TIA), or amaurosis fugax (AF), and with an ipsilateral symptomatic CA stenosis of 50% or more, and (2) the risk of stroke in CA interventions within 48 hours of admission versus the risk in interventions performed after 48 hours. METHODS Ninety-four patients were included in this study. These patients were admitted to hospital within 48 hours of a nondisabling stroke, TIA, or AF resulting from a symptomatic CA stenosis of 50% or more. The patients underwent carotid endarterectomy (85 patients) or CA stenting (9 patients). At baseline, the cardiovascular risk factors of the patients, the degree of symptomatic CA stenosis, and the type of secondary preventive treatment were assessed. The in-hospital recurrence rate of stroke, TIA, or AF ipsilateral to the symptomatic CA stenosis was determined for the first 72 hours after admission, from 72 hours to 7 days, and after 7 days. Procedure-related cerebrovascular events were also recorded. RESULTS The median time from symptom onset to CA intervention was 5 days (interquartile range 3.00-9.25 days). Twenty-one patients (22.3%) underwent CA intervention within 48 hours after being admitted. Overall, 15 recurrent cerebrovascular events were observed in 12 patients (12.8%) in the period between admission and CA intervention: 3 strokes (2 strokes in progress and 1 stroke) (3.2%), 5 TIAs (5.3%), and 1 AF (1.1%) occurred within the first 72 hours (total 9.6%) of admission; 1 TIA (1.1%) occurred between 72 hours and 7 days, and 5 TIAs (5.3%) occurred after more than 7 days. The corresponding actuarial cerebrovascular recurrence rates were 11.4% (within 72 hours of admission), 2.4% (between 72 hours and 7 days), and 7.9% (after 7 days). Among baseline characteristics, no predictive factors for cerebrovascular recurrence were identified. Procedure-related cerebrovascular events occurred at a rate of 4.3% (3 strokes and 1 TIA), and procedures performed within the first 48 hours and procedures performed after 48 hours had a similar frequency of these events (4.5% vs. 4.1%, respectively; p = 0.896). CONCLUSIONS The in-hospital recurrence of cerebrovascular events was quite low, but all recurrent strokes occurred within 72 hours. The risk of stroke associated with a CA intervention performed within the first 48 hours was not increased compared with that for later interventions. This raises the question of the optimal timing of CA intervention in symptomatic CA stenosis. To answer this question, more data are needed, preferably from large randomized trials.

Hohlraum Target for Overcoming Refractive Losses in Plasma X-ray Lasers

Refractive losses in laser-produced plasmas used as gain media are caused by electron density gradients, and limit the energy transport range. The pump pulse is thus deflected from the high-gain region and the short wavelength laser signal also steers away, causing loss of collimation. A Hohlraum used as a target makes the plasma homogeneous and can mitigate refractive losses by means of wave-guiding. A computational study combining a hydrodynamics code and an atomic physics code is presented, which includes a ray-tracing modeling based on the eikonal theory of the trajectory equation. This study presents gain calculations based on population inversion produced by free-electron collisions exciting bound electrons into metastable levels in the 3d94d1(J = 0) → 3d94p1(J = 1) transition of Ni-like Sn. Further, the Hohlraum suggests a dramatic enhancement of the conversion efficiency of collisionally excited x-ray lasing for Ni-like Sn.