The impact of optimal dating on the assessment of fetal growth.

BACKGROUND: The impact of using the Intergrowth (IG) dating formulae in comparison to the commonly used Robinson dating on the evaluation of biometrics and estimated fetal weight (EFW) has not been evaluated. METHODS: Nationwide cross-sectional study of routine fetal ultrasound biometry in low-risk pregnant women whose gestational age (GA) had been previously assessed by a first trimester CRL measurement. We compared the CRL-based GA according to the Robinson formula and the IG formula. We evaluated the fetal biometric measurements as well as the EFW taken later in pregnancy depending on the dating formula used. Mean and standard deviation of the Z scores as well as the number and percentage of cases classified as <3rd, < 10th, >90th and > 97th percentile were compared. RESULTS: Three thousand five hundred twenty-two low-risk women with scans carried out after 18 weeks were included. There were differences of zero, one and 2 days in 642 (18.2%), 2700 (76.7%) and 180 (5%) when GA was estimated based on the Robinson or the IG formula, respectively. The biometry Z scores assessed later in pregnancy were all statistically significantly lower when the Intergrowth-based dating formula was used (p < 10- 4). Likewise, the number and percentage of foetuses classified as <3rd, < 10th, >90th and > 97th percentile demonstrated significant differences. As an example, the proportion of SGA foetuses varied from 3.46 to 4.57% (p = 0.02) and that of LGA foetuses from 17.86 to 13.4% (p < 10- 4). CONCLUSION: The dating formula used has a quite significant impact on the subsequent evaluation of biometry and EFW. We suggest that the combined and homogeneous use of a recent dating standard, together with prescriptive growth standards established on the same low-risk pregnancies, allows an optimal assessment of fetal growth.

A rapid chair-side method for the estimation of oral bacterial colonization density.

AIMS: Caries and periodontal disease are associated with inadequate control of oral bacteria. Since conventional microbiological evaluations are impractical in dental clinics or public engagement activities, a rapid test for the quantification of oral bacteria represents a useful tool. We describe the development of a colour change test to rapidly estimate bacterial colonisation density in the mouth. METHODS AND RESULTS: Volunteers rinsed with milk or milkshake. Viability indicators were added and colour changes quantified during incubation. Using milkshake and the resazurin-based solution PrestoBlue (9% v/v), the method distinguished between samples before and after brushing within 5 min. Colour changes were quantified and viable counts were obtained using oral rinses. Measured colour changes strongly correlated with total counts of both anaerobes and streptococci (Spearman's correlation coefficient of 0·782 and 0·769, respectively, P ≤ 0·001) and with perceived changes, as determined by volunteers (n = 10) visually ranking images. CONCLUSIONS: The resazurin milkshake test can rapidly and visually quantify viable bacteria in oral samples. SIGNIFICANCE AND IMPACT OF THE STUDY: The resazurin milkshake test could serve as a sensitive semi-quantitative method for measuring oral bacteria in human oral rinse samples.

[An independent observatory in Vendée on ST-elevated acute myocardial infarction (the OVISCA Register). A Departmental evaluation of demographic trends, mortality and delays before treatment]. / Observatoire Vendéen indépendant des syndromes Coronarien aigus avec sus-décalage du segment ST (Registre OVISCA). Évaluation départementale, évolution démographique, mortalité, délais de prise en charge.

AIM: Mortality from acute myocardial infarction has been falling during the past 30 years. The aim of the study was to evaluate the temporal trends of demographics, mortality rates, and time to treatment in patients admitted for acute ST elevation myocardial infarction (STEMI) in Vendée. PATIENTS AND METHODS: From 2008 to 2016, 1994 patients hospitalised in CHD Vendée for STEMI <48hours were included. Two groups were compared, 838 patients admitted between 2008 and 2011 (group 1), and 1156 admitted between 2013 and 2016 (group 2). RESULTS: Between the 2 periods, mean age was comparable (63.8 vs. 64.4 years), the gender ratio decreased (from 3.15 to 2.79 ; P=0.25). The mean duration of hospital stay was 0.8 day shorter (P=0.008). Treatment at discharge was optimum in 97.5% patients versus 92% (P<0.001). Left ventricular ejection fraction was comparable (50.6% vs. 50.2%). There was a non-significant trend to a decrease in hospital mortality (from 6.3% to 4.4%; p=0.12), and 6-month mortality (from 6.9% to 5.9%; P=0.51). There was a reduction in the use of emergency call-outs (74.9% to 68.9%; P<0.01), but an increase in direct presentations from 44% to 48.7% (P<0.05). The time before calling was comparable (2.5hours vs. 2.3hours; P=04.7). The "door-to-balloon" time decreased (0.71 vs. 0.55hour; P<0.001). The mean time between pain and angioplasty increased (5.7 vs. 6.8hours; P<0.05). CONCLUSIONS: In vendee, from 2011 to 2016, hospital and 6-month mortality of STEMI trend to decrease non-significantly. The door to balloon time decreased, although emergency call-out rates and delays did not. Considerable efforts are still required with respect to patient information and education. Our registry offers an excellent tool to improve practices, the aim being to ensure its integration in the CRAC-France PCI registry.

Treatment of maxillary retained canine with implants: new perspectives.

PURPOSE: The surgical-orthodontic treatment of impacted maxillary canine (IMC) remains a challenge to today's clinicians. The aim of the present paper is to describe an unconventional treatment of IMC with insertion of implant into the retained canine and 3 years follow-up. CASE REPORT: A 55-year-old female patient attended to rehabilitate her maxillary left canine site. An unconventional approach was proposed to the patient. A large diameter tapered implant (Ø 5 × 18 mm) was inserted (Nobel Active, Kolten, Swisse). An immediate loading prosthetic rehabilitation was performed. After checking for implant stability the prosthetic steps were carried out and a single crown was delivered with Procera system. CONCLUSION: The patient was happy of this kind of single non-invasive session for treating IMC. At the 3-year control, the implant did not show any mobility or signs of peri-implantitis clinically or radiographically. In addiction patient was satisfied of aesthetic results.

Retrospective analysis of technical success rate and procedure-related complications of 867 percutaneous CT-guided needle biopsies of lung lesions.

AIM: To investigate the technical success rate and procedure-related complications of computed tomography (CT)-guided needle biopsy of lung lesions and to identify the factors that are correlated with the occurrence of procedure-related complications. MATERIALS AND METHODS: This was a single- institution retrospective study of 867 consecutive CT-guided needle biopsies of lung lesions performed on 772 patients in a tertiary cancer centre. The technical success rate and complications were correlated with patient, lung lesion, and procedure-related variables. RESULTS: The technical success rate was 87.2% and the mortality rate was 0.12%. Of the 867 total biopsies 25.7% were associated with pneumothorax, and 6.5% required chest tube drainage. The haemothorax rate was 1.8%. There was positive correlation between the development of pneumothorax and smaller lesion diameter (p<0.001), longer transparenchymal distance (p<0.001), and prone position (p=0.027). There was positive correlation between the need for chest tube placement and longer transparenchymal distance (p=0.007) and smaller lesion diameter (p=0.018). Lesions in the left lower lobe had the lowest rates of pneumothorax (p=0.008) and chest tube drainage (p=0.018). Patients whose pneumothoraces were diagnosed on the follow-up chest X-ray, but not on the immediate post-procedural CT scan had significantly higher requirement for chest tube drainage (p=0.039). CONCLUSION: CT-guided lung biopsy has a high rate of technical success and a low rate of major complications. The present study has revealed several variables that can be used to identify high-risk procedures. A post-procedural chest X-ray within hours after the procedure is highly recommended to identify high-risk patients who require chest tube placement.

An unusual, deceptive delayed of profuse haemorrhage after mandibular implant dentistry: risk planning and medico-legal instruction.

Mandibular implant placement (MIP) has been accepted and widely used for decades all over the world, and has reached a very high level of therapeutic reliability. MIP is used mostly in elderly edentulous patients who lost their teeth when dentistry was not oriented to fixed or removable prosthetic. Notwithstanding this, every year cases of severe complications during MIP due to haemorrhage causing life-threatening airway's obstruction are reported. These severe complications of MIP need immediate therapy, usually with hospitalization, and may be potentially fatal. A 56-year-old man presented to the private practice requesting the placement of two dental implants at 41 and 31 previously lost for periodontal disease. Two implants of 3.3 mm of diameter, and 10 mm of length were inserted replacing teeth 31 and 41. Two hours after surgery and home delivery, the patient came to the emergency room complaining of dyspnoea and edema at the floor of the mouth. The maxillo-facial surgeon decided to perform tracheostomy and haemostasis under general anaesthesia. Two weeks after demission a complete healing was performed. This is important for dental practitioners to avoid severe bleeding complications during the MIP in the interforaminal region, especially on the midline. Moreover, when mandibles are severely atrophic, practitioners should be aware of this fact and the possible implications. The evaluation of these data is essential in the correct preoperative planning of implant procedures in the mandible, and with the increasing demand for MIP, the variations of the lingual foramen of the mandible should receive more attention.

Altered iPSC-derived neurons' sodium channel properties in subjects with Monge's disease.

Monge's disease, also known as chronic mountain sickness (CMS), is a disease that potentially threatens more than 140 million highlanders during extended time living at high altitudes (over 2500m). The prevalence of CMS in Andeans is about 15-20%, suggesting that the majority of highlanders (non-CMS) are rather healthy at high altitudes; however, CMS subjects experience severe hypoxemia, erythrocytosis and many neurologic manifestations including migraine, headache, mental fatigue, confusion, and memory loss. The underlying mechanisms of CMS neuropathology are not well understood and no ideal treatment is available to prevent or cure CMS, except for phlebotomy. In the current study, we reprogrammed fibroblast cells from both CMS and non-CMS subjects' skin biopsies into the induced pluripotent stem cells (iPSCs), then differentiated into neurons and compared their neuronal properties. We discovered that CMS neurons were much less excitable (higher rheobase) than non-CMS neurons. This decreased excitability was not caused by differences in passive neuronal properties, but instead by a significantly lowered Na(+) channel current density and by a shift of the voltage-conductance curve in the depolarization direction. Our findings provide, for the first time, evidence of a neuronal abnormality in CMS subjects as compared to non-CMS subjects, hoping that such studies can pave the way to a better understanding of the neuropathology in CMS.

Modeling non-syndromic autism and the impact of TRPC6 disruption in human neurons.

An increasing number of genetic variants have been implicated in autism spectrum disorders (ASDs), and the functional study of such variants will be critical for the elucidation of autism pathophysiology. Here, we report a de novo balanced translocation disruption of TRPC6, a cation channel, in a non-syndromic autistic individual. Using multiple models, such as dental pulp cells, induced pluripotent stem cell (iPSC)-derived neuronal cells and mouse models, we demonstrate that TRPC6 reduction or haploinsufficiency leads to altered neuronal development, morphology and function. The observed neuronal phenotypes could then be rescued by TRPC6 complementation and by treatment with insulin-like growth factor-1 or hyperforin, a TRPC6-specific agonist, suggesting that ASD individuals with alterations in this pathway may benefit from these drugs. We also demonstrate that methyl CpG binding protein-2 (MeCP2) levels affect TRPC6 expression. Mutations in MeCP2 cause Rett syndrome, revealing common pathways among ASDs. Genetic sequencing of TRPC6 in 1041 ASD individuals and 2872 controls revealed significantly more nonsynonymous mutations in the ASD population, and identified loss-of-function mutations with incomplete penetrance in two patients. Taken together, these findings suggest that TRPC6 is a novel predisposing gene for ASD that may act in a multiple-hit model. This is the first study to use iPSC-derived human neurons to model non-syndromic ASD and illustrate the potential of modeling genetically complex sporadic diseases using such cells.

Biparietal/transverse abdominal diameter ratio ≤ 1: potential marker for open spina bifida at 11-13-week scan.

OBJECTIVE: In the first trimester of pregnancy, a biparietal diameter (BPD) below the 5(th) percentile is a simple marker that enables the prenatal detection of half of all cases of open spina bifida. We hypothesized that relating the BPD measurement to the transverse abdominal diameter (TAD) might be another simple and effective screening method. In this study we assessed the performance of using the BPD/TAD ratio during the first trimester of pregnancy in screening for open spina bifida. METHODS: A total of 20,551 first-trimester ultrasound scans (11-13 weeks' gestation), performed between 2000 and 2013, were analyzed retrospectively; there were 26 cases of open spina bifida and 17,665 unaffected pregnancies with a crown-rump length of 45-84 mm and a record of both BPD and TAD measurements. RESULTS: The mean (± SD) BPD/TAD ratio was 1.00 ± 0.06 for fetuses with spina bifida and 1.13 ± 0.06 for those without (P < 0.0001). A BPD ≤ 5(th) percentile enabled the prenatal detection of 46.2% of spina bifida cases, while a BPD/TAD ratio of ≤ 1.00 detected 69.2%. If we considered cases in which either BPD was ≤ 5(th) percentile or BPD/TAD ratio was ≤ 1, we identified 76.9% of cases. In the latter case, the false-positive rate was 5.1%, while that for using a combination of both BPD ≤ 5th percentile and BPD/TAD ratio ≤ 1 was 0.6%, with a sensitivity of 38.5%. The positive predictive value of using a combination of BPD ≤ 5th percentile and BPD/TAD ratio ≤ 1 for detecting spina bifida was 8.5%. CONCLUSIONS: Between 11 and 13 weeks' gestation, relating BPD to TAD improves considerably the diagnostic performance of using BPD measurement alone in screening for open spina bifida. Screening using this marker is simple and applicable to a large population.

Patterns and outcomes of aortofemoral bypass grafting in the era of endovascular interventions.

OBJECTIVES: The aim of the study is to study contemporary presentation patterns and clinical results in patients undergoing aortofemoral bypass (AFB) surgery. DESIGN: This was a retrospective comparative study. MATERIAL AND METHODS: During a 14-year period, 269 consecutive patients (mean age 65 years) underwent AFB. Indications included occlusive disease with severe intermittent claudication (IC) (n = 86), critical limb ischaemia (CLI, n = 97) and aneurysmo-occlusive disease (n = 86). RESULTS: From 2000-07 on, AFB was performed more frequently for occlusive disease with CLI than for other indications (48% vs. 31% before 2000, P = 0.009) and also in women (51% vs. 32% before 2000, P = 0.003), compared to the period before 2000. Thirty-day mortality was reduced during 2000-2007 to 2.4%, compared with 4.3% during 1993-1999, although this difference was not statistically significant (P = 0.73). Morbidity did not change substantially over the study period. Predictors of 30-day mortality included indication (CLI = 4.1% vs. claudication = 1.2% (P = 0.37)) and chronic kidney disease (CKD, serum creatinine > 1.5 mg dl⁻¹) (11.1% vs. 2.9% in normal renal function, P = 0.07), the latter being the single predictor on multivariate analysis (hazard risk 4.2, P = 0.047). Overall 5 and 10-year assisted primary and secondary patency was 95% and 88%, and 99% and 95%, respectively. Survival at 5 and 10 years was 69% and 48%, respectively. Patient age (hazard risk 1.05, P < 0.001), CKD (hazard risk 1.79, P = 0.018) and diabetes (hazard risk 1.56, P = 0.022) were independent predictors of worse long-term survival. Long-term outcome did not change over the course of the study. CONCLUSIONS: In the contemporary era, AFB is more likely to be performed for CLI and in women than in the past. Despite these changes, perioperative mortality and morbidity remain low and long-term outcome excellent.

[Awareness and knowledge about risks of drinking during pregnancy in pregnant Lebanese women]. / Les conduites d'alcoolisation des femmes enceintes libanaises et leurs connaissances sur les risques et répercussions sur l'enfant à naître.

OBJECTIVE: To assess the awareness and knowledge of pregnant Lebanese women about the risks of drinking during pregnancy and the factors that influence their drinking patterns. MATERIALS AND METHODS: A prospective study was conducted on a sample of 107 women consulting the gynecology outpatient department of Hôtel-Dieu de France in Beirut, Lebanon, who completed the T-ACE screening test included in a 21 multiple choice questionnaire which examine knowledge and beliefs about alcohol use during pregnancy, drinking patterns and awareness of fetal alcohol exposure. RESULTS: The 107 women of our sample were all married, between 20 and 41 years old and had mostly a high educational level (86%). Most of the women (47%) were at their first pregnancy. Of the 20 women who self-reported drinking during pregnancy, 60% obtained a positive score on the T-ACE questionnaire, which indicates that more than 11% of the women engaged with potentially high risk drinking for the baby. There is not a significant difference between the different age categories or educational levels. This proportion is lower than that found in international publications. However, the rate of excessive drinking (4 drinks or more on any one occasion in females) was higher and one woman in five reported excessive drinking in the previous year. There is a high level of knowledge that alcohol use during pregnancy is harmful to the child, and the more consumption the more harmful and likely the effects, but there is confusion about the safety of small amounts of alcohol. Women (37%) think that there is a safe level of drinking during pregnancy; 29% tolerate up to one drink a month, 9% tolerate up to one drink a week and one woman thinks having one drink a day is safe. Women who actually drink during pregnancy are more likely to think that alcohol consumption to a certain level is safe. Women (31%) think that beer and/or wine are safe alcohols to a certain level during pregnancy. When asked about the source of this belief, 22% mention a gynecologist but the majority (61%) says it is a personal belief. Women (65%) in our sample are aware that alcohol use during pregnancy can lead to life-long disabilities in a child, such as delayed development (36%), birth defects/deformities (35%) and mental retardation (32%). However, up to 33% of the respondents report having no information about the effects of alcohol on the fetus and two women believe alcohol is not harmful at all. Women with lower levels of education are somewhat less knowledgeable about the risks of alcohol use during pregnancy than those with higher levels of education. There is no association between the drinking patterns of the women with their age, their professional habits and the alcohol consumption of their husbands. The women in our sample seem to be more aware of the necessity to stop smoking rather than stop drinking during pregnancy. CONCLUSION: Lebanese women are not fully aware of the recommendations and risks related to drinking during pregnancy. This is the reason why action must be taken to ensure better diffusion of these recommendations and better assessment of alcohol intake during prenatal visits.

Long-term complication and patency rates of Vectra and IMPRA Carboflo vascular access grafts with aggressive monitoring, surveillance and endovascular management.

The purpose of this study is to compare infection, pseudoaneurysm formation and patency rates during long-term follow-up of polyurethane and polytetrafluoroethylene (PTFE) vascular access grafts maintained with contemporary endovascular methods. During a 34-month period, 239 polyurethane and 125 carbon-impregnated PTFE vascular access grafts were placed in 324 consecutive patients. Thirty-six patients (9.9%) developed a pseudoaneurysm (anastomotic, n = 6 or at the needle-stick site, n = 30). An additional 19 patients (5.2%) required graft excision for infection. Three-year graft infection and pseudoaneurysm formation (at needle-stick site) rates were similar in polyurethane and PTFE grafts (11% versus 8%, P = 0.61, and 17% versus 23%, P = 0.72, respectively). Three-year secondary patency was better in polyurethane than PTFE grafts (69% versus 57%, respectively, P = 0.012). Straight upper arm polyurethane grafts had the best secondary patency (P = 0.001). Contemporary long-term secondary patency of vascular access grafts is satisfactory. Further follow-up is necessary to compare late infection and pseudoaneurysm formation rates.

Review: Hypoxic and oxidative stress resistance in Drosophila melanogaster.

Oxygen (O(2)) is essential for aerobic life; however, the level of O(2), whether too low (hypoxia) or too high (hyperoxia), can induce oxidative injury and increase morbidity and mortality. Disruption of O(2) homeostasis represents a major aspect of many disease etiologies and pathobiology. In the past, our laboratory has been using Drosophila melanogaster to investigate the cellular and molecular aspects of the response to hypoxia and oxidative stress. There are several advantages for using Drosophila as a model system, the most important one being an evolutionary conservation of genetic and signaling pathways from Drosophila to mammals. As a proof of this concept, we have shown that we can substantially improve the tolerance of human cells in culture by transfecting these cells with particular Drosophila genes. In this review, we summarize the recent findings from our laboratory using Drosophila as a model system to investigate the genetic basis of hypoxia/hyperoxia tolerance. We have done microarray studies and identified several oxidative stress resistance genes that play an important role in individual paradigms such as constant or intermittent hypoxia, short term (days) or long term (generations) hypoxia/hyperoxia. Our studies provide evidence that a pattern of oxidative stress is specific in inducing a gene expression profile which, in turn, plays an important role in modulating the phenotype. To improve our understanding of oxidative and hypoxic stress as well as its associated diseases, multi-disciplinary approaches are necessary and critical in the study of complicated issues in systems biology.

Basilic vein transposition: what is the optimal technique?

OBJECTIVES: To compare the outcome of the one-stage basilic vein transposition (BVT) fistula with a modified, two-stage technique. DESIGN: Retrospective case-controlled study, performed in an academic centre. MATERIAL: A total of 173 candidates for BVT fistula (87 males, mean age 61 years). METHODS: In one-stage BVT, the basilic vein is mobilised through a single incision, placed inside an anterolateral arm tunnel and anastomosed with the brachial artery. In two-stage procedures, the fistula-arterial anastomosis is created first, followed by the second stage, after fistula maturation several weeks later, when the basilic vein is mobilised through two skip incisions, transected near the anastomosis, placed inside an anterolateral arm tunnel and reanastomosed. Morbidity and fistula maturation rate were the main outcome measures. RESULTS: In one-stage BVT (n=76), the incidence of venous hypertension, wound haematomas and all complications (17%, 13% and 43%, respectively) was significantly higher than in two-stage procedures (n=98) (4%, p=0.004, 3%, p=0.012 and 11%, p<0.001, respectively). Time (68 days) to fistula use was significantly decreased in one-stage BVT than in two-stage procedures (132 days, p<0.001) but failure to mature rate was equivalent (15% vs. 18%, p=0.49). CONCLUSIONS: Our results indicate that the two-stage BVT fistula through two skip-arm incisions is superior to the established one-stage procedure in terms of less morbidity but at the cost of a second operation and longer time to access use. Further research comparing these two techniques is necessary. Until this issue is resolved, an individualised approach is suggested.

Association between palmoplantar pustulosis and cigarette smoking in Brazil: a case-control study.

BACKGROUND: Palmoplantar pustulosis (PPP) discloses some differences compared to vulgar psoriasis (PV) in terms of age of onset, female predominance and low occurrence of psoriasis lesions elsewhere. Cigarette smoking has been associated to PPP in international studies; nevertheless, these studies were never performed among Brazilian. OBJECTIVES: To compare prevalence of smoking among PPP, PV and other dermatologic patients (NPD). METHODS: Case-control study involving 25 PPP patients from a reference psoriasis centre. Two control groups were matched according to gender and age: 50 patients with PV and 50 NPD. Confounders were adjusted by conditional multiple logistic regression. RESULTS: Among cases, 84.0% were female and PPP age of disease onset (41.4 years) was greater than PV (34.5 years). Prevalence of ever smoking was higher among cases (92.0%) than PV (52.0%) and NPD (30.0%). Adjusted odds ratio of PPP ever smoking compared to PV and NPD was 9.5 and 36.2, respectively. All smokers reported the onset of their habit before the development of PPP. CONCLUSIONS: There was significant association between PPP and smoking. However, the impact of giving it up in the clinical course of the disease remains to be established.

Secondary patency of thrombosed prosthetic vascular access grafts with aggressive surveillance, monitoring and endovascular management.

BACKGROUND: To study the long-term patency of thrombosed prosthetic vascular access grafts treated with percutaneous mechanical thrombectomy (PMT) followed by aggressive surveillance and monitoring and repeated endovascular interventions. STUDY DESIGN: Two hundred seven vascular access grafts presented with first-time thrombosis were treated with PMT using the AngioJet device (n=185) or the Arrow-Trerotola percutaneous thrombolytic device (n=22) followed by angioplasty (+/- stenting) of the anatomical lesion responsible for the thrombotic event. Clinical success was considered at least one successful subsequent hemodialysis session. Graft surveillance/monitoring included clinical and hemodialysis parameters to detect a failing or thrombosed graft. RESULTS: PMT was technically successful in 202 cases (97.6%) and clinically successful in 193 cases (93.2%). During follow-up, 149 got thrombosed and either abandoned (n=33) or underwent at least once repeat thrombectomy (n=116); finally 100 grafts were abandoned (n=90), ligated (n=5) or removed (n=5). Endovascular management (0.54 procedures per 100 graft-days, thrombectomy, n=307 sessions and angioplasty, n=162 sessions) increased significantly functional assisted-primary patency rates from 29% and 14% at 1 and 2 years to a secondary patency of 62% and 47%, respectively. Secondary patency was worse in loop grafts (P=.02) and intermediate graft thrombosis (occurred between 31-182 days after graft placement, P<.001) and better when renal failure was due to hypertension or diabetes (compared to other or cryptogenic causes, P=.048) or isolated angioplasty for graft dysfunction during follow-up had been performed (P<.001). Multivariate analysis identified intermediate graft thrombosis and isolated angioplasty as independent predictors of secondary patency (P<.001, relative risk 2.77 and P<.001, relative risk 0.28, respectively). CONCLUSIONS: PMT is a highly successful procedure with acceptable long-term secondary patency results, provided that aggressive endovascular management of subsequent thrombotic or dysfunction episode is performed. Further research to identify the causes of intermediate graft thrombosis is justified.

The sodium-activated potassium channel Slack is modulated by hypercapnia and acidosis.

Slack (Slo 2.2), a member of the Slo potassium channel family, is activated by both voltage and cytosolic factors, such as Na(+) ([Na(+)](i)) and Cl(-) ([Cl(-)](i)). Since the Slo family is known to play a role in hypoxia, and since hypoxia/ischemia is associated with an increase in H(+) and CO(2) intracellularly, we hypothesized that the Slack channel may be affected by changes in intracellular concentrations of CO(2) and H(+). To examine this, we expressed the Slack channel in Xenopus oocytes and the Slo 2.2 protein was allowed to be inserted into the plasma membrane. Inside-out patch recordings were performed to examine the response of Slack to different CO(2) concentrations (0.038%, 5%, 12%) and to different pH levels (6.3, 6.8, 7.3, 7.8, 8.3). In the presence of low [Na(+)](i) (5 mM), the Slack channel open probability decreased when exposed to decreased pH or increased CO(2) in a dose-dependent fashion (from 0.28+/-0.03, n=3, at pH 7.3 to 0.006+/-0.005, n=3, P=0.0004, at pH 6.8; and from 0.65+/-0.17, n=3, at 0.038% CO(2) to 0.22+/-0.07, n=3, P=0.04 at 12% CO(2)). In the presence of high [Na(+)](i) (45 mM), Slack open probability increased (from 0.03+/-0.01 at 5 mM [Na(+)](i), n=3, to 0.11+/-0.01, n=3, P=0.01) even in the presence of decreased pH (6.3). Since Slack activity increases significantly when exposed to increased [Na(+)](i), even in presence of increased H(+), we propose that Slack may play an important role in pathological conditions during which there is an increase in the intracellular concentrations of both acid and Na(+), such as in ischemia/hypoxia.