Comparaison de l’Airtraq, du X-Lite et du laryngoscope standard pour la chirurgie thyroïdienne: une étude clinique randomisée

Purpose

To compare the performance of the Airtraq, X-Lite, and direct laryngoscopes for tracheal intubation for elective thyroid surgery.

Methods

In this randomized prospective study, Patients who were ASA (American Society of Anesthesiologists) I or II physical status I or II and patients undergoing thyroid surgery were included in this randomized prospective study. Patients with attributes for difficult intubation criteria were excluded. After induction of anesthesia with fentanyl, propofol, and cisatracurium, patients were randomized into three groups according to the intubating device used: Airtraq laryngoscope (Airtraq), X-Lite video laryngoscope (X-lLite), and direct laryngoscope with a Macintosh blade (Direct). The primary outcome measurement was the time needed for tracheal intubation. Secondary outcomes included intubation difficulty score (IDS), Cormack-Lehane classification, as well as hemodynamic and respiratory effects.

Results

One hundred and five patients were included. Mean (standard deviation) time for intubation was 28.2 (2.1) sec in the Airtraq group vs 36.6 (3.7) sec in the X-Lite group (P < 0.001), and 41.1 (4.4) sec in the Direct group (P < 0.001). Compared with to the direct laryngoscope, the Airtraq provided better visualization of the glottis (P = 0.003) with fewer attempts (P < 0.001) and lower IDS (P < 0.001). The intubation difficulty score was lower with the Airtraq than with the X-Lite (P = 0.003). Patients in the X-Lite and Direct groups showed more hemodynamic variations than those in the Airtraq group. There was only one failed intubation, in the direct group.

Conclusion

In thyroid surgery, the Airtraq and X-Lite laryngoscopes decrease time to intubation when compared with direct laryngoscopy.     

Is the knowledge of contact force beneficial in pulmonary vein antrum isolation?

Objective: To investigate the effect of the operator knowing the real-time contact force (CF) on the efficacy of pulmonary vein antrum isolation (PVAI).

Methods: Fifty patients with paroxysmal atrial fibrillation (AF) or short lasting persistent AF were randomized to CF guided PVAI (n?=?25) or conventional PVAI (n?=?25). In the CF guided group, CF between 10 and 40?g was aimed at. Efficacy of PVAI was measured as reduction in AF burden (AFB) and time to AF recurrence detected by implantable cardiac monitor (ICM), inserted three months before PVAI. Blanking period was three months and follow-up 12 months.

Results: All pulmonary veins were isolated in the CF guided group and all but one in the conventional group. Mean CF was 25?g in the CF guided group and 24?g in the conventional group (p?=?0.75). Compared to pre-ablation, median [IQR] relative reduction in AFB 3–12 months after ablation was 100 [99–100]% in the CF guided group (p?p?p?=?0.09). Nine patients (36%) had AF recurrence in the CF guided group and 13 (52%) in the conventional group (p?=?0.21, log-rank test). CF differed between operators. When adjusted for operator by regression analysis, patients without recurrent AF had lower proportion of ablation time with CF <10?g than recurrent patients (p?=?0.034). No complications occurred.

Conclusions: Operator knowledge of real-time CF had no significant effect on AFB reduction or time to AF recurrence. Larger trials should be done to study benefit of real-time CF.     

Muscle Strength and Damage Following Two Modes of Variable Resistance Training

Nautilus Machine (NM) and Elastic Resistance (ER) have gained considerable popularity among athletes and recreational lifters seeking to increase muscle strength. However, there is controversy concerning the use of ER for increasing muscle hypertrophy and strength among healthy-trained individuals. The aim of the study was to compare the effect of repeated near maximal contractions by ER/NM on indicators of muscle damage including: maximal strength decrement (MVIC), rate of muscle soreness (DOMS), concentration of plasma creatine kinase (CK) and increased high muscle signal on T2 weighted images using magnetic resonance imaging (MRI). Nine healthy male subjects completed two modalities of exercise (5 sets × 10RM ER/NM) in a counterbalance cross-over study design with three weeks “wash-out” period between experiments. The MVIC was measured and DOMS rated and recorded for 4 consecutive days while blood samples were collected on day 1, 3, 5 and 7. Prior to and forty eight hours after completion of each mode of exercise, subjects underwent MRI scanning. The average of applied forces demonstrated significantly higher value for NM compared with ER (362 ± 34.2 N vs 266.73 ± 44.6 N respectively) throughout the 5 sets of dynamic exercise (all p < 0.05). However, the indicators of muscle damage (T2 relaxation time, DOMS, MVIC and serum CK) exhibited a very similar response across both modes of training. Plasma CK increased significantly following both modes of training with the peak value on Day 3 (p < 0.05). The time course of muscle soreness reached a significant level after both modes of exercise and showed a peak value on the 2^nd day (p < 0.05). The T2 relaxation time demonstrated a statistically significant increase following ER and NM compared with the pre-test value (p < 0.05). The similarity of these responses following both the ER and NM exercise training session suggests that both modes of training provide a similar training stress; despite a considerably lower external force generation during ER. The importance of these findings is underlined by the fact that exercise-induced muscle damage has been shown to be the underlying mechanism of further muscle hypertrophy.

Key points

• Exercise induced muscle soreness increased levels of plasma CK, increased MRI T2 signal and prolonged strength loss indicate the moderate to intense nature of the training protocol.
• The similarity of these responses following both the Elastic Resistance and Nautilus Machine exercise training session suggests that both modes of training provide a similar training stress; despite a considerably lower external force generation during ER.
• The data in the present study suggest elastic training is a viable mode of resistance exercise that can provide a training stimulus greater than that employed in rehabilitation settings.

Key words: Elastic resistance training, magnetic resonance imaging, muscle strain, muscle hypertrophy     

Contribution of Fc fragment of monoclonal antibodies to tetanus toxin neutralization

Neurotoxicity Research - Monoclonal antibodies (MAbs) against neurotoxin of Clostridium tetani are considered as a novel source of immunoglobulins for passive immunotherapy of tetanus. Toxin...     

Long‐term accumulation of microglia with proneurogenic phenotype concomitant with persistent neurogenesis in adult subventricular zone after stroke

Neural stem cells (NSCs) in the adult rat subventricular zone (SVZ) generate new striatal neurons during several months after ischemic stroke. Whether the microglial response associated with ischemic injury extends into SVZ and influences neuroblast production is unknown. Here, we demonstrate increased numbers of activated microglia in ipsilateral SVZ concomitant with neuroblast migration into the striatum at 2, 6, and 16 weeks, with maximum at 6 weeks, following 2 h middle cerebral artery occlusion in rats. In the peri‐infarct striatum, numbers of activated microglia peaked already at 2 weeks and declined thereafter. Microglia in SVZ were resident or originated from bone marrow, with maximum proliferation during the first 2 weeks postinsult. In SVZ, microglia exhibited ramified or intermediate morphology, signifying a downregulated inflammatory profile, whereas amoeboid or round phagocytic microglia were frequent in the peri‐infarct striatum. Numbers of microglia expressing markers of antigen‐presenting cells (MHC‐II, CD86) increased in SVZ but very few lymphocytes were detected. Using quantitative PCR, strong short‐ and long‐term increase (at 1 and 6 weeks postinfarct) of insulin‐like growth factor‐1 (IGF‐1) gene expression was detected in SVZ tissue. Elevated numbers of IGF‐1‐expressing microglia were found in SVZ at 2, 6, and 16 weeks after stroke. At 16 weeks, 5% of microglia but no other cells in SVZ expressed the IGF‐1 protein, which mitigates apoptosis and promotes proliferation and differentiation of NSCs. The long‐term accumulation of microglia with proneurogenic phenotype in the SVZ implies a supportive role of these cells for the continuous neurogenesis after stroke. © 2008 Wiley‐Liss, Inc.     

The superiority of polymerase chain reaction over an amplified enzyme immunoassay for the detection of genital chlamydial infections

BACKGROUND/OBJECTIVES: The polymer conjugate enhanced enzyme immunoassay (IDEIA) and Cobas Amplicor polymerase chain reaction Chlamydia trachomatis (CT) (Amplicor PCR) are two commonly used assays for the diagnosis of CT infection. The performance of these assays was compared for the diagnosis of genital CT infection among 1000 consecutive patients attending a genitourinary medicine (GUM) clinic. Confirmation of positive results and the clinical significance of the absence of cryptic plasmid in chlamydia on the diagnosis of infection by Amplicor PCR were also investigated. METHODS: IDEIA, Amplicor PCR, and two nested in-house PCR assays targeting cryptic plasmid and omp1 gene were performed on all samples. DNA from Amplicor PCR negative samples was pooled for in-house PCR assays. Each pool contained DNA from seven Amplicor PCR negative samples. RESULTS: Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and efficiency of IDEIA in the diagnosis of genital CT infection were 80%, 97%, 80%, 97%, and 95%, respectively. Sensitivity, specificity, PPV, NPV and efficiency of Amplicor PCR were 99%, 98%, 89%, 100%, and 98%, respectively. 16 (11%) of 144 Amplicor PCR positive results were identified as false positive by in-house PCR assays. No isolate of plasmid free CT was detected among the study population. CONCLUSIONS: IDEIA should not be used for the diagnosis of CT infection because of its poor sensitivity. Although the analytic specificity of Amplicor PCR was 98%, because of the adverse medical, social, and psychological impact of false positive results for patients, confirmation of Amplicor PCR positive results by a different assay with comparable sensitivity is essential. Amplification assays targeting cryptic plasmid are appropriate for the diagnosis of genital CT infections.     

Parathyroid hormone regulation of NA+,K+-ATPase requires the PDZ 1 domain of sodium hydrogen exchanger regulatory factor-1 in opossum kidney cells

It was demonstrated that expression of murine sodium hydrogen exchanger regulatory factor (NHERF-1) lacking the ezrin-binding domain blocks parathyroid hormone (PTH) regulation of Na+,K+-ATPase in opossum kidney (OK) cells. The hypothesis that the NHERF-1 PDZ domains contribute to PTH regulation of Na+,K+-ATPase was tested by comparison of PTH regulation of Na+,K+-ATPase in wild-type OK (OK-WT) cells, NHERF-deficient OKH cells, OK-WT transfected with siRNA for NHERF (NHERF siRNA OK-WT), and OKH cells that were stably transfected with full-length NHERF-1 or constructs with mutated PDZ domains. OKH cells and NHERF siRNA OK-WT showed decreased expression of NHERF-1 but equivalent expression of ezrin and Na+,K+-ATPase alpha1 subunit when compared with OK-WT cells. PTH decreased Na+,K+-ATPase activity and stimulated phosphorylation of the Na+,K+-ATPase alpha1 in OK-WT cells but not in NHERF-deficient cells. Rubidium (86Rb) uptake was equivalent in OK-WT, OKH, and OKH cells that were transfected with all but the double PDZ domain mutants. PTH decreased 86Rb uptake significantly in OK-WT but not in OKH cells. PTH also significantly inhibited 86Rb uptake in OKH cells that were transfected with full-length NHERF-1 or NHERF-1 with mutated PDZ 2 but not in OKH cells that were transfected with mutated PDZ 1. Transfection with NHERF expressing both mutated PDZ domains resulted in diminished basal 86Rb uptake that was not inhibited further by PTH. PTH stimulated protein kinase Calpha activity and alpha1 subunit phosphorylation in OK-WT but not in NHERF-deficient cells. Transfection of OKH cells with NHERF constructs that contained an intact PDZ1 domain restored PTH-stimulated protein kinase Calpha activity and alpha1 subunit phosphorylation. These results demonstrate that NHERF-1 is necessary for PTH-mediated inhibition of Na+,K+-ATPase activity and that the inhibition is mediated through the PDZ1, not PDZ2, domain.