Thoracic epidural analgesia prolongs postoperative QT interval on electrocardiogram in major non-cardiac surgery: a randomized comparison and a prospective cohort analysis.

Introduction: Prolongation of QT interval on electrocardiogram can be associated with perioperative lethal arrhythmia. Epidural analgesia is a commonly used modality to relieve surgical pain by blocking sensory nerves, which also blocks the autonomic nervous system and can affect QT interval. Since patient monitoring becomes much less frequent after surgery than intraoperative period, we investigated the effects of epidural analgesia on postoperative QT interval with a randomized clinical trial and a prospective cohort study. Methods: In a randomized study, we assigned 60 patients undergoing thoracic epidural analgesia to an epidural analgesia or no-epidural analgesia group, in which 3 ml/h of 0.25% epidural levobupivacaine (7.5 mg/h) was administered only in the epidural analgesia group during surgery. The primary outcome was the postoperative heart rate-corrected QT interval. In a prospective cohort study, patients were assigned to receive 5 ml/h epidural levobupivacaine (12.5 mg/h). The plasma concentration of levobupivacaine was measured using liquid chromatography-mass spectrometry. Results: The median postoperative corrected QT interval interval with 3 ml/h epidural levobupivacaine was significantly longer than that without epidural analgesia. Using multiple regression analysis for the factors known to affect postoperative corrected QT interval interval, epidural analgesia was found to be an independent variable for prolongation, and the mean difference of the corrected QT interval interval with or without epidural analgesia was 23 ms after adjustment. The median plasma concentration of levobupivacaine at the end of surgery was 164 ng/ml with 3 ml/h epidural levobupivacaine, and the correlation coefficient to the postoperative corrected QT interval interval was 0.14, showing a not significant correlation. A prospective cohort study showed that 5 ml/h epidural levobupivacaine significantly prolonged postoperative corrected QT interval interval compared to preoperative baseline. The median plasma concentration of levobupivacaine was 166 ng/ml with 5 ml/h, the correlation coefficient of which showed no significant correlation. Conclusion: Thoracic epidural analgesia could enhance postoperative corrected QT interval prolongation after general anesthesia. The mechanism is possibly caused by blocking neighboring or part of the cardiac sympathetic nerves, rather than by systemic effects of epidurally administered levobupivacaine. Clinical trial number: UMIN000013347 for the randomized study and UMIN000041518 for the prospective cohort study, which were registered at University hospital Medical Information Network Center.

Usefulness of Practitioner-Led Pancreatic Cancer Screening.

The 5-year survival rate for pancreatic cancer has improved (10%) but remains worse than that for other cancers. Early pancreatic cancer diagnosis is challenging, and delayed diagnosis can delay treatment, which impairs survival. Practitioners do not promptly refer cases to a general hospital, causing delayed discovery. Herein, we aimed to examine the usefulness of the Pancreatic Cancer Project in Matsue, whose objective is to detect pancreatic cancer in patients presenting at any medical institution in Matsue City. Clinical data were extracted from medical records, and abdominal ultrasonography and tumor marker blood level assessments were performed (n = 234; median age, 71 [range, 41-94] years; 51% male). Cases with abnormal abdominal ultrasonography or blood test findings were referred for specialist imaging and followed up. The pancreatic cancer detection rate was 6.0% (n = 14); all cases were referred to a general hospital by practitioners within 1 month. Patients had stage IA (n = 1), IIA (n = 6), IIB (n = 2), III (n = 1), and IV (n = 4) disease. Overall, pancreatic cancer could be detected at an earlier stage (I-II), but referral to a general hospital by visiting practitioners should be prompt. The Pancreatic Cancer Project in Matsue may help improve the detection and prognosis of pancreatic cancer.

Lipid emulsion facilitates reversal from volatile anesthetics in a rodent model.

BACKGROUND: Lipid emulsion infusion is a first-line therapy against the toxicity of local anesthetics and is a potential treatment for other drug overdoses, especially for highly lipophilic drugs. Considering the lipophilic property of volatile anesthetics, we hypothesized that lipid emulsion could reverse general anesthesia. METHODS: Using adult rats, we tested the effect of lipid emulsion infusion on time to emergence after discontinuation of sevoflurane and isoflurane, and further evaluated restoration of righting reflex under continuous sevoflurane anesthesia. Electroencephalogram during lipid emulsion infusion was also investigated under continuous sevoflurane inhalation. The effect of lipid emulsion on sevoflurane-induced respiratory and hemodynamic depressions was evaluated by measuring respiratory rate, PaCO2 (arterial partial pressure of CO2), blood pressure, and heart rate. The binding property of lipid emulsion on sevoflurane and isoflurane was assessed using in vitro setting with a conical flask. RESULTS: Lipid emulsion infusion significantly decreased time to emergence from sevoflurane anesthesia (131 ± 53 vs. 237 ± 69 s) and restored righting reflex during continuous sevoflurane inhalation, by comparing normal saline infusion. Consistent with the behavioral findings, the electroencephalogram under continuous sevoflurane showed decreased power of the δ bands at 5 min after the initiation of lipid emulsion infusion. In addition to reversing hypnosis, lipid emulsion recovered respiratory as well as hemodynamic depressions induced by sevoflurane. Decreased time to emergence was observed also in isoflurane anesthesia (203 ± 111 vs. 314 ± 154 s). To investigate the binding mechanism of lipid emulsion infusion, in vitro experiments revealed significantly decreased anesthetic concentrations of sevoflurane and isoflurane by mixing with lipid emulsion. CONCLUSIONS: Lipid emulsion facilitated reversal from volatile anesthetics, as shown by several parameters. As lipid emulsion could bind to volatile anesthetics and simply decrease their effects, our findings suggest that lipid emulsion is a potentially useful agent to reverse general anesthesia.

Orai1 Channels Are Essential for Amplification of Glutamate-Evoked Ca2+ Signals in Dendritic Spines to Regulate Working and Associative Memory.

Store-operated Orai1 calcium channels function as highly Ca2+-selective ion channels and are broadly expressed in many tissues including the central nervous system, but their contributions to cognitive processing are largely unknown. Here, we report that many measures of synaptic, cellular, and behavioral models of learning are markedly attenuated in mice lacking Orai1 in forebrain excitatory neurons. Results with focal glutamate uncaging in hippocampal neurons support an essential role of Orai1 channels in amplifying NMDA-receptor-induced dendritic Ca2+ transients that drive activity-dependent spine morphogenesis and long-term potentiation at Schaffer collateral-CA1 synapses. Consistent with these signaling roles, mice lacking Orai1 in pyramidal neurons (but not interneurons) exhibit striking deficits in working and associative memory tasks. These findings identify Orai1 channels as essential regulators of dendritic spine Ca2+ signaling, synaptic plasticity, and cognition.

Left Ventricular Hypertrophy Increases Susceptibility to Bupivacaine-induced Cardiotoxicity through Overexpression of Transient Receptor Potential Canonical Channels in Rats.

BACKGROUND: Local anesthetics, particularly potent long acting ones such as bupivacaine, can cause cardiotoxicity by inhibiting sodium ion channels; however, the impact of left ventricular hypertrophy on the cardiotoxicity and the underlying mechanisms remain undetermined. Transient receptor potential canonical (TRPC) channels are upregulated in left ventricular hypertrophy. Some transient receptor potential channel subtypes have been reported to pass relatively large cations, including protonated local anesthetics; this is known as the "pore phenomenon." The authors hypothesized that bupivacaine-induced cardiotoxicity is more severe in left ventricular hypertrophy due to upregulated TRPC channels. METHODS: The authors used a modified transverse aortic constriction model as a left ventricular hypertrophy. Cardiotoxicity caused by bupivacaine was compared between sham and aortic constriction male rats, and the underlying mechanisms were investigated by recording sodium ion channel currents and immunocytochemistry of TRPC protein in cardiomyocytes. RESULTS: The time to cardiac arrest by bupivacaine was shorter in aortic constriction rats (n =11) than in sham rats (n = 12) (mean ± SD, 1,302 ± 324 s vs. 1,034 ± 211 s; P = 0.030), regardless of its lower plasma concentration. The half-maximal inhibitory concentrations of bupivacaine toward sodium ion currents were 4.5 and 4.3 µM, which decreased to 3.9 and 2.6 µM in sham and aortic constriction rats, respectively, upon coapplication of 1-oleoyl-2-acetyl-sn-glycerol, a TRPC3 channel activator. In both groups, sodium ion currents were unaffected by QX-314, a positively charged lidocaine derivative, that hardly permeates the cell membrane, but was significantly decreased with QX-314 and 1-oleoyl-2-acetyl-sn-glycerol coapplication (sham: 79 ± 10% of control; P = 0.004; aortic constriction: 47± 27% of control; P = 0.020; n = 5 cells per group). Effects of 1-oleoyl-2-acetyl-sn-glycerol were antagonized by a specific TRPC3 channel inhibitor. CONCLUSIONS: Left ventricular hypertrophy exacerbated bupivacaine-induced cardiotoxicity, which could be a consequence of the "pore phenomenon" of TRPC3 channels upregulated in left ventricular hypertrophy.

Regulation of chemoconvulsant-induced seizures by store-operated Orai1 channels.

KEY POINTS: Temporal lobe epilepsy is a complex neurological disease caused by imbalance of excitation and inhibition in the brain. Growing literature implicates altered Ca2+ signalling in many aspects of epilepsy but the diversity of Ca2+ channels that regulate this syndrome are not well-understood. Here, we report that mice lacking the store-operated Ca2+ channel, Orai1, in the brain show markedly stronger seizures in response to the chemoconvulsants, kainic acid and pilocarpine. Electrophysiological analysis reveals that selective deletion of Orai1 channels in inhibitory neurons disables chemoconvulsant-induced excitation of GABAergic neurons in the CA1 hippocampus. Likewise, deletion of Orai1 in GABAergic neurons abrogates the chemoconvulsant-induced burst of spontaneous inhibitory postsynaptic currents (sIPSCs) on CA1 pyramidal neurons in the hippocampus. This loss of chemoconvulsant inhibition likely aggravates status epilepticus in Orai1 KO mice. These results identify Orai1 channels as regulators of hippocampal interneuron excitability and seizures. ABSTRACT: Store-operated Orai1 channels are a major mechanism for Ca2+ entry in many cells and mediate numerous functions including gene expression, cytokine production and gliotransmitter release. Orai1 is expressed in many regions of the mammalian brain; however, its role in regulating neuronal excitability, synaptic function and brain disorders has only now begun to be investigated. To investigate a potential role of Orai1 channels in status epilepticus induced by chemoconvulsants, we examined acute seizures evoked by intraperitoneal injections of kainic acid (KA) and pilocarpine in mice with a conditional deletion of Orai1 (or its activator STIM1) in the brain. Brain-specific Orai1 and STIM1 knockout (KO) mice exhibited significantly stronger seizures (P = 0.00003 and P < 0.00001), and higher chemoconvulsant-induced mortality (P = 0.02) compared with wildtype (WT) littermates. Electrophysiological recordings in hippocampal brain slices revealed that KA stimulated the activity of inhibitory interneurons in the CA1 hippocampus (P = 0.04) which failed to occur in Orai1 KO mice. Further, KA and pilocarpine increased the frequency of spontaneous IPSCs in CA1 pyramidal neurons >twofold (KA: P = 0.04; pilocarpine: P = 0.0002) which was abolished in Orai1 KO mice. Mice with selective deletion of Orai1 in GABAergic neurons alone also showed stronger seizures to KA (P = 0.001) and pilocarpine (P < 0.00001) and loss of chemoconvulsant-induced increases in sIPSC responses compared with WT controls. We conclude that Orai1 channels regulate chemoconvulsant-induced excitation in GABAergic neurons and that destabilization of the excitatory/inhibitory balance in Orai1 KO mice aggravates chemoconvulsant-mediated seizures. These results identify Orai1 channels as novel molecular regulators of hippocampal neuronal excitability and seizures.

CRAC channels regulate astrocyte Ca2+ signaling and gliotransmitter release to modulate hippocampal GABAergic transmission.

Astrocytes are the major glial subtype in the brain and mediate numerous functions ranging from metabolic support to gliotransmitter release through signaling mechanisms controlled by Ca2+ Despite intense interest, the Ca2+ influx pathways in astrocytes remain obscure, hindering mechanistic insights into how Ca2+ signaling is coupled to downstream astrocyte-mediated effector functions. Here, we identified store-operated Ca2+ release-activated Ca2+ (CRAC) channels encoded by Orai1 and STIM1 as a major route of Ca2+ entry for driving sustained and oscillatory Ca2+ signals in astrocytes after stimulation of metabotropic purinergic and protease-activated receptors. Using synaptopHluorin as an optical reporter, we showed that the opening of astrocyte CRAC channels stimulated vesicular exocytosis to mediate the release of gliotransmitters, including ATP. Furthermore, slice electrophysiological recordings showed that activation of astrocytes by protease-activated receptors stimulated interneurons in the CA1 hippocampus to increase inhibitory postsynaptic currents on CA1 pyramidal cells. These results reveal a central role for CRAC channels as regulators of astrocyte Ca2+ signaling, gliotransmitter release, and astrocyte-mediated tonic inhibition of CA1 pyramidal neurons.

Superior Efficacy of Lipid Emulsion Infusion Over Serum Alkalinization in Reversing Amitriptyline-Induced Cardiotoxicity in Guinea Pig.

BACKGROUND: Tricyclic antidepressants (TCAs) are a major cause of fatal drug poisoning due to their cardiotoxicity. Alkalinization by sodium bicarbonate (NaHCO3) administration, the first-line therapy for TCA-induced cardiotoxicity, can occasionally yield insufficient efficacy in severe cases. Because most TCAs are highly lipophilic, lipid emulsion may be more effective than alkalinization. However, it remains to be determined whether lipid emulsion is more beneficial than alkalinization in reversing amitriptyline-induced cardiotoxicity. METHODS: Hemodynamic variables were recorded from in vivo guinea pig models and Langendorff-perfused hearts. Whole-cell patch-clamp experiments were conducted on enzymatically isolated ventricular cardiomyocytes to record fast sodium currents (INa). Lipid solutions were prepared using 20% Intralipid. The pH of the alkaline solution was set at 7.55. We assessed the effect of lipid emulsion on reversing amitriptyline-induced cardiotoxicity, in vivo and in vitro, compared to alkalinization. The data were evaluated by Student t test, 1-way repeated-measures analysis of variance, or analysis of covariance (covariate = amitriptyline concentration); we considered data statistically significant when P < .05. RESULTS: In the in vivo model, intervention with lipids significantly reversed the amitriptyline-induced depression of mean arterial pressure and prolongation of QRS duration on electrocardiogram more than alkalinization (mean arterial pressure, mean difference [95% confidence interval]: 19.0 mm Hg [8.5-29.4]; QRS duration, mean difference [95% confidence interval] -12.0 milliseconds [-16.1 to -7.8]). In the Langendorff experiments, perfusion with 1% and 2% lipid solutions demonstrated significant recovery in left ventricular developed pressure (LVdevP), maximum change rate of increase of LVdevP (dP/dtmax) and rate-pressure product compared with alkaline solution (LVdevP [mm Hg], alkaline 57 ± 35, 1% lipid 94 ± 12, 2% lipid 110 ± 14; dP/dtmax [mm Hg/s], alkaline 748 ± 441, 1% lipid 1502 ± 334, 2% lipid 1753 ± 389; rate-pressure product [mm Hg·beats·minute], alkaline 11,214 ± 8272, 1% lipid 19,025 ± 8427, 2% lipid 25,261 ± 4803 with analysis of covariance). Furthermore, lipid solutions (0.5%-4%) resulted in greater recovery of hemodynamic parameters at 3 µM amitriptyline. Amitriptyline inhibited INa in a dose-dependent manner: the half-maximal inhibitory concentration (IC50) was 0.39 µM. The IC50 increased to 0.75 µM in the alkaline solution, 3.2 µM in 1% lipid solution, and 6.1 µM in 2% lipid solution. Furthermore, the lipid solution attenuated the use-dependent block of sodium channels by amitriptyline more than alkaline solution. On 30 consecutive pulses at 1 Hz, the current decreased to 50.1 ± 2.1, 60.3 ± 1.9, and 90.4% ± 1.8% in standard, alkaline, and 1% lipid solution, respectively. Even 0.5% lipid solution showed greater effects than the alkaline solution in all experiments. CONCLUSIONS: Lipid emulsion significantly suppressed amitriptyline-induced INa, inhibition, which was likely related to the marked improvement in hemodynamic status observed in vivo and in isolated perfused hearts. These results suggest the superiority of lipid emulsion as the first-line therapy for TCA-induced cardiotoxicity compared to alkalinization therapy.

Rapid sequence spinal anesthesia for the most urgent cesarean section: a simulation and clinical application.

Rapid sequence spinal anesthesia is a recently developed technique for the most urgent, category-1 cesarean section. To successfully perform this technique, it is important to multi-disciplinarily discuss with all staffs related to delivery, make a local protocol in each hospital and simulate the procedure with them. Owing to the above preparation, we were able to perform the technique smoothly also in the real patient. Considering possible benefits of rapid sequence spinal anesthesia, we should prepare enough before we use it in the actual clinical situations.

Usefulness and growing need for intraoperative transthoracic echocardiography: a case series.

BACKGROUND: Physician-performed transthoracic echocardiography (TTE) is still seldom used during anesthesia. Despite its various advantages, there are only a few reports of intraoperative TTE. We report 3 cases in which intraoperative TTE was successfully used. CASE PRESENTATION: A 75-year-old woman (Case 1) was scheduled for a posterior spinal fusion. When the wound was being closed, systolic blood pressure suddenly dropped to 30 mmHg. TTE revealed hypokinesis in the antero-septal region. Emergent coronary angiography showed 90% stenosis in left anterior descending artery (Segment 7), and a bare metal stent was implanted. A 71-year-old woman (Case 2) with hypertrophic cardiomyopathy was scheduled for brain tumor operation. During anesthesia induction, the patient developed hemodynamic instability. TTE showed systolic anterior motion of the mitral valve, and appropriate treatment was administered. A 78-year-old woman (Case 3) was scheduled for revision total hip arthroplasty. When the wound was closed, TTE revealed severe hypovolemia despite massive infusion. We insisted on reopening the wound and found additional massive hemorrhage. CONCLUSION: Intraoperative TTE is a potent tool for quick hemodynamic evaluation because it is noninvasive and has sufficient diagnostic capabilities. The successful outcomes of our cases suggest the great usefulness of intraoperative TTE, and more frequent use is to be encouraged.

The effect of lipid emulsion on intracellular bupivacaine as a mechanism of lipid resuscitation: an electrophysiological study using voltage-gated proton channels.

BACKGROUND: Lipid resuscitation has become a standard treatment for local anesthetic (LA) systemic toxicity, but its mechanisms remain to be fully elucidated. Although the partitioning effect is one of the proposed mechanisms, it is difficult to evaluate its impact independently from several other mechanisms or to examine the intracellular concentration of a LA, which is primarily responsible for LA systemic toxicity. We recently reported that LAs as weak bases reduced voltage-gated proton currents by increasing intracellular pH, which could be estimated from the reversal potentials of the channels (Vrev). Using this characteristic, we examined the partitioning effect in detail and showed its impact on lipid resuscitation. METHODS: A whole-cell voltage clamp technique was used to record proton channel currents in a rat microglial cell line (GMI-R1). We used Intralipid® 20% as lipid emulsion. The effects of lipid emulsion on the intracellular concentrations of LAs were evaluated by measuring the current amplitude and the Vrev. The intracellular concentrations of LAs were calculated by the Henderson-Hasselbalch equation, using estimated intracellular pH. To confirm the importance of partitioning, we separated lipid by centrifugation. Data are means ± SD unless otherwise stated. RESULTS: Bupivacaine (1 mM) decreased proton currents to 43% ± 10% of the control and shifted the Vrev to positive voltages (from -88.0 ± 4.1 to -76.0 ± 5.5 mV, n = 5 each, P = 0.02). An addition of the lipid emulsion recovered the currents to 79% ± 2% of the control and returned the Vrev toward the control value (to -86.0 ± 7.1 mV, n = 5, P = 0.03). Both recoveries of the current and Vrev in the centrifuged aqueous extract were almost the same as in the 4% lipid solution (-85.6 ± 4.9 mV, n = 5, P = 0.9, 95% confidence interval for difference = -9.3 to 8.6). When 1 mM bupivacaine was applied extracellularly, the intracellular concentration of the charged form of bupivacaine was estimated to reach about 18.1 ± 3.9 mM but decreased to 5.4 ± 1.8 mM by the 4% lipid solution. CONCLUSIONS: Here we quantitatively evaluated for the first time the partitioning effect of lipid emulsion therapy on the intracellular concentration of bupivacaine in real-time settings by analyzing behaviors of voltage-gated proton channels. Our results suggested that lipid emulsion markedly reduced the intracellular concentration of bupivacaine, which was mostly due to the partitioning effect. This could contribute to our understanding of the mechanisms underlying lipid resuscitation, especially the importance of the partitioning effect.

Acquired intraventricular arachnoid cyst of the third ventricle--case report.

A 35-year-old male showed slow progression of dilation of the lateral ventricles and third ventricle. He had undergone surgery for third ventricular colloid cyst and ventriculoperitoneal shunting when he was 3 years old. Computed tomography revealed progression of triventricular dilation. He underwent endoscopic fenestration of the arachnoid cyst and endoscopic third ventriculostomy. The postoperative course was good. Arachnoid cysts within the third ventricle are rare. Endoscopic treatment of an arachnoid cyst within the third ventricle is less invasive and effective for arachnoid cysts within the third ventricle associated with hydrocephalus.

[Case of chronic trifascicular block resulting in cardiac arrest during operation].

An 82-year-old man underwent thoracoscopic upper lobectomy of the left lung for the treatment of the lung cancer. The major complication was asymptomatic chronic trifascicular block. During the surgery, after the upper lobe had been resected, second degree atrioventricular block (Morbitz type II) occurred unexpectedly, soon evolving in complete AV block, with pulse wave disappearing, indicating pulseless electrical activity. Immediately, we used an epicardial pacing wire, and spontaneous circulation returned. Postoperatively, a permanent pacemaker was implanted. Asymptomatic chronic bifascicular block and trifascicular block rarely progress into complete AV block during operation, which we should be prepared in advance. Accordingly in some cases, preoperative insertion of a temporary pacemaker should be considered as a preventive measure.

Periprocedural hemodynamic instability with carotid angioplasty and stenting.

BACKGROUND: Carotid angioplasty and stenting is used for treatment of carotid stenosis. Stent deployment may induce HDI and thereby cause systemic or neurologic deficits. This study defines characteristics and predictors of HDI with CAS. METHODS: A total of 132 patients who had undergone CAS were evaluated for periprocedural and postprocedural HDI (hypertension, systolic blood pressure >160 mm Hg; hypotension, systolic blood pressure <90 mm Hg; or bradycardia, heart rate <60 beats per minute). RESULTS: Frequencies of HDI were 6.8% for hypertension, 32.6% for hypotension, and 15.9% for bradycardia. In addition, CAS of the right side (P < .01), carotid bulb lesions (P < .05), eccentric posterior carotid plaque (P < .0001), and general anesthesia (P < .05) were associated significantly with postprocedural HDI. Male sex (OR, 3.4; 95% CI, 1.8-67.2; P < .001), age of 80 years or older (OR, 0.4; 95%CI, 0.1-1.4; P = .011), and plaque ulceration (OR, 0.5; 95% CI, 0.1-9.5; P = .008) independently predicted postprocedural hypertension. Male sex (OR, 2.5; 95% CI, 1.3-24.9; P < .001), preprocedural major stroke (OR, 0.1; 95% CI, 0.01-0.8; P = .002), carotid bulb lesions (OR, 1.6; 95% CI, 1.1-25.9; P = .024), and contralateral carotid occlusion (OR, 0.6; 95% CI, 0.2-4.9; P = .040) all predicted postprocedural hypotension. Bradycardia was associated with diabetes mellitus (OR, 0.7; 95% CI, 0.3-2.4; P = .033), preprocedural TIA (OR, 1.7; 95% CI, 1.4-17.9; P = .020), and minor stroke (OR, 1.5; 95% CI, 1-10.9; P = .037). In 5 patients, HDI predisposed neurologic or systemic deterioration. CONCLUSIONS: Hemodynamic instability is common with CAS; hypotension and bradycardia are more frequent than hypertension. Some clinical, angiographic, and procedural variables can predict these HD changes.

Access site complications with carotid angioplasty and stenting.

BACKGROUND: Carotid angioplasty and stenting is a relatively new therapeutic alternative to CEA for treatment of carotid stenosis. The percutaneous transfemoral approach, the standard technique for angioplasty and stent deployment, may not be feasible in all patients. We present our experience with access site complications that occurred with CAS. METHODS: One hundred thirty-two CAS procedures were performed at our institution in the past 5 years for symptomatic (62.1%) or asymptomatic (37.9%) carotid stenosis. Mean age of patients was 70.72 +/- 6.53 years and the mean degree of stenosis of the treated carotids was 80.74% +/- 11.83%. The transfemoral approach was the access route in 126 CAS, the transbrachial approach was used in 2 CAS procedures, and direct carotid exposure was used in 5 patients. RESULTS: All CAS procedures were done successfully; 4 (3%) access site complications were detected, 3 (2.4%) groin hematomas with transfemoral approach and 1 hematoma on the left side of the neck, in patients treated with direct carotid cutdown. Surgical repair of FSA was successfully performed for the patients with groin hematoma, whereas surgical wound exploration in the neck for the remaining patient revealed no identifiable cause. All patients received blood transfusion for correction of associated hypovolemia or hemorrhagic anemia. No patients had experienced access site-related additional cardiac, systemic, or neurologic events. CONCLUSIONS: The authors' experience demonstrates that access site complications are rare events with CAS despite the large diameter of implantable devices and liberal anticoagulant and antiplatelet therapy. Transbrachial and direct carotid approaches are relatively safe, accepted alternatives in the setting of contraindicated femoral access.

Subcellular positioning of F plasmid mediated by dynamic localization of SopA and SopB.

SopA, SopB proteins and the cis-acting sopC DNA region of F plasmid are essential for partitioning of the plasmid, ensuring proper subcellular positioning of the plasmid DNA molecules. We have analyzed by immunofluorescence microscopy the subcellular localization of SopA and SopB. The majority of SopB molecules formed foci, which localized frequently with F plasmid DNA molecules. The foci increased in number in proportion to the cell length. Interestingly, beside the foci formation, SopB formed a spiral structure that was dependent on SopA, which also formed a spiral structure, independent of the presence of SopB, and these two structures partially overlapped. On the basis of these results and previous biochemical studies together with our simulations, we propose a theoretical model named "the reaction-diffusion partitioning model", using reaction-diffusion equations that explain the dynamic subcellular localization of SopA and SopB proteins and the subcellular positioning of F plasmid. We hypothesized that sister copies of plasmid DNA compete with each other for sites at which SopB multimer is at the optimum concentration. The plasmid incompatibility mediated by the Sop system might be explained clearly by this hypothesis.