On the other hand, brand E is very similar to brand A in these fe

On the other hand, brand E is very similar to brand A in these features, and they both present extreme behaviour in the presence of the additives. Consequently, other important characteristics of the cigarettes, DAPT mouse such as the tobacco type and composition, additives included during manufacturing, the paper additives and permeability, which are not specified by the tobacco

companies, may affect their behaviour. In a previous paper [22] the composition of the smoke evolved from these tobacco cigarettes brands was studied and multivariant analysis was applied to establish relationships among the main features of the cigarette design and the smoke composition. It was shown as some of the variables considered, especially the WTC and also filter and paper length, play an important role in the smoking process. By brands the classification of the studied brands based on the chemical composition of the gas phase and the TPM revealed

that brand C always appeared separated from the other brands, while brands G, H and I form a homogeneous group. Nevertheless, in this work, with the inclusion of the catalyst in the tobacco, the scene is much more complex and such relationships have not been found. Table 4 shows, as an example, the results of the gas fraction analysed by GC/FID in the case of tobacco F, which is the one where the largest reductions were observed, Selleck Lumacaftor while Table 5 shows the results for the compounds condensed in the filters and Vorinostat mw in the CFP, analysed by GC/MS. The results obtained for the other brands are annexed as supplementary data. The distribution of the different

compounds retained in the filters and in the CFP reveals that the filters seem to preferably retain the lighter components, whereas the heaviest are preferably retained in the CFP located thereafter. This trend was also observed in previous works [21] and [22] and may be related to the vapour pressure of the different compounds, their affinity for the filter and the traps and their relative concentrations in addition to the pressure fluctuations during and between the puffs [4] and [14]. In the following, the analysis of liquids is carried out on the sum of the yields obtained in filters plus traps, in order to better represent the additives action. Figure 3 shows the total yields obtained for HCN, 1,3-butadiene, benzene, acetaldehyde from the gas fraction and phenol and nicotine from the liquid fraction. These compounds have been selected because of their high toxicity, since all of them are included in the Hoffman and in the Canadian lists (Hofmann and Hofmann, 1997; [3]; WHO technical report series 951). According to [10], HCN is the smoke component presenting the highest index of cardiovascular effects, while 1,3-butadiene is the one showing the highest cancer risk index (CRI).

The 2008 IFOMPT Educational Standards Document is the culmination

The 2008 IFOMPT Educational Standards Document is the culmination of such a demand and forms the basis of manual therapy education programmes in its Member Countries. The “Maitland Concept” is now a truly global phenomenon. There will not be many National Physiotherapy Associations throughout the World that will not be aware of “Maitland”. Geoff’s classic texts, Vertebral Manipulation, now in its 7th edition and Peripheral Manipulation, now in its 4th edition, are available world-wide and have been translated into several

languages including Japanese, selleck chemical Spanish and German. These Physiotherapy books still feature in publisher’s best-seller lists. The honours Geoff received during his career are a testament to the esteemed regard in which he is held by the Physiotherapy World. Notably he received the MBE in 1981 and

The Mildred Elson Award from the WCPT in 1995 for his life’s work. The legacy of the life’s work of G.D. Maitland is assured and can be seen developing within the work of others and their organisations. Take, for example, Mark Jones who has taken Geoff’s decision making process and developed it into a structured and evidence-based Clinical Reasoning framework. David Butler and his NOI have SD-208 taken Geoff’s early research on “pain-sensitive structures in the vertebral canal” and Bob Elvey’s work on “The Upper Limb Tension Test” and advanced our knowledge, skills and strategies for dealing with neurogenic and other pain mechanisms. Peter Wells and his colleagues from the MACP were greatly influenced by Geoff’s work and teachings as they followed on from Morin Hydrate Greg Grieve in shaping the future of Manipulative

Physiotherapy in the UK. Gisela Rolf along with Geoff and Peter Wells helped to establish the International Maitland Teacher’s Association [IMTA] which has continued to serve many European Countries with quality Manual Therapy education based on Geoff’s principles and practice. In summary, G.D. Maitland supported by Anne and his close family and colleagues has established his place in our Profession’s History. He is the Donald Bradman of Physiotherapists. Sir Donald, a fellow Australian, had a career Test Match batting average of 99.94 and, as with Geoff, many have aspired to reach such a standard but none, to date, have come anywhere near.

Results demonstrated that the mAb assay correlated well with dens

Results demonstrated that the mAb assay correlated well with densitometry (representative data in Fig. 3). Given the success of the mAb assay at detecting FLC in urine, the clinical utility of the mAb assay was then assessed in 13,090 unconcentrated urine samples sent to the laboratory for routine FLC analysis between April 2008 and Nov 2010. All samples were also analysed by urine IFE (the gold standard for presence of LC in urine) to assess the specificity of the mAb assay, and to ensure that the mAb assay detected all FLC paraproteins.

All samples were analysed as they arrived in the laboratory. After initial routine analyses, samples were stored Gefitinib at − 20 °C. 2995 samples (22.8%) had monoclonal κ, 1180 samples (9.0%) had monoclonal λ, and 105 samples (0.8%) had poly LC, as detected by IFE. 12,242 of these samples were from patients who had a known immunoglobulin paraprotein in serum by IFE (93.5%), 641 samples had no paraprotein in matched serum, and 207 had no serum IFE diagnosis or no serum available. 3806 samples were received from patients enrolled in myeloma trials and the remaining 9284 samples were non-trial samples. Because two anti-κ FLC and two anti-λ FLC mAbs were used in each test, UK-371804 cell line the maximal concentration detected by each anti-κ (BUCIS 01

or BUCIS 04) and each anti-λ mAb (BUCIS 03 or BUCIS 09) was chosen as the final urine FLC result. As a means of determining

the specificity of the mAb assay in urine, any results that were immunofixation positive and mAb assay negative (recorded clinically as < 10 mg/L), were classed as discrepant. To ensure that each of the anti-FLC mAbs targeted all FLC epitopes, all discrepant samples were re-tested on the mAb assay and by urine IFE. If a discrepancy remained, a full urine IFE was conducted to exclude the presence of whole paraprotein because initial IFE used anti-sera against LC free and bound. Further investigation of matched serum and patient history was conducted DOK2 where necessary and available. Freelite™ κ and λ FLC assays were conducted on a Roche Hitachi Modular analyser using manufacturer’s instructions. The reported working range of Freelite™ on this instrument from the manufacturer was 3.7–56.2 mg/L for κ FLC and 5.6–74.8 mg/L for λ FLC (Bradwell, 2008). Urine and serum IFE was performed using Hydragel IF 2/4 gels on a Hydrasys analyser according to manufacturer’s instructions (all antisera from Sebia, France). Routine serum IFE comprised a panel of antisera against: bound and free κ and λ LC, IgA, IgM, and IgG. Where necessary, antisera against IgD, IgE, and κ and λ FLCs were also used. Routine IFE on unconcentrated urine comprised a panel of antisera against bound and free κ and λ LC. Where necessary, antisera against IgA, IgD, IgE, IgG, IgM and κ and λ FLCs were used.

In MEFs adduct formation increased with time at 20 μM but at 50 μ

In MEFs adduct formation increased with time at 20 μM but at 50 μM after 48 h resulted in lower adduct levels (compare Fig. 2F). As indicated above, it may be possible that the increased cytotoxicity at this condition may have impacted metabolic activation of the compound and/or DNA adduct formation. Highest DNA binding in MEFs was observed at 50 μM after 24 h with 2810 ± 1048

adducts per 108 nucleotides which was 468-fold higher than the adduct levels observed under the same experimental conditions in ES cells (6 ± 3 adducts per 108 nucleotides). AAI-induced Histone Acetyltransferase inhibitor DNA damage in MEFs was associated with a strong induction of the DNA damage response proteins p53 and p21 ( Fig. 4B). Interestingly, AAI exposure also led to a

strong p53 induction in ES cells and also subsequently its downstream target p21 but at considerably lower DNA adduct levels than in MEFs. In ES cells neither Nqo1 nor Cyp1a1 mRNA expression was significantly altered after AAI treatment (Figs. 5E and 6E). In contrast, we found a significant induction of Nqo1 and Cyp1a1 in MEFs (Figs. 5F and 6F) but the levels of transcriptional alterations in MEFs are very small, and thus do not explain GDC-0980 the differences of AAI–DNA adduct formation observed in the two cell types. Further, as the basal Cyp1a1 and Nqo1 mRNA expression levels in untreated ES cells and MEFs were only marginally different, if at all (see legends to Fig. 5 and Fig. 6), this also did not provide

an explanation for the huge differences in AAI–DNA adduct formation between cell types. Therefore we investigated whether the observed alterations in AAI-induced DNA damage are linked to epigenetic changes. Tumours are characterized by a global reduction in DNA methylation (hypomethylation) and/or a locus-specific increase in DNA methylation (hypermethylation) (Esteller, 2008). DNA methylation can regulate gene expression and it has been shown in cancer cells that DNA hypermethylation of CpG islands near tumour suppressor genes switches off the expression of these genes (Tommasi et al., 2014). Further, it has been suggested that epigenetic mechanisms may function as an interface between environmental factors and the genome and that aberrant epigenetic changes associated with environmental TCL exposures might deregulate not only key cellular processes such as DNA damage response and DNA repair but also carcinogen metabolism (Herceg and Vaissiere, 2011). Several environmental pollutants have been shown to affect DNA methylation in mammalian cells in vitro. Tabish et al. (2012) demonstrated for example that benzene, hydroquinone, styrene, carbon tetrachloride and trichloroethylene induced global DNA hypomethylation in human TK6 cells. However, little is known about equivalent mechanisms in embryonic stem cells or MEFs.

All spectra were obtained in the positive-ion mode

All spectra were obtained in the positive-ion mode. SB431542 Data acquisition and deconvolution of data were performed on Xcalibur Windows NT PC data acquisition system. OcyKTx2 was compared against all α-KTxs described until now (for a complete list see http://www.uniprot.org/docs/scorpktx). Multiple sequence alignments were performed by ClustalW XXL (at http://embnet.vital-it.ch/software/ClustalW-XXL.html) followed by manual adjustment. This result was subsequently used to build phylogenetic analysis and consensus sequences. In the sequence matrix, all positions containing gaps and missing data were eliminated. The Maximum

Parsimony method with 500 Bootstrap replications and Close–Neighbor–Interchange algorithm model on MEGA 5 software were used in the reconstruction of the phylogenetic tree. The analysis involved 124 amino acid sequences. Insect Sf9 cells were grown at 27 °C in Grace’s

media (Gibco BRL). The cells were infected with a multiplicity of infection of 10, with a recombinant baculovirus (Autographa californica nuclear polyhedrosis virus) containing the cDNA of Shaker-B K+-channels. Electrophysiological recordings were conducted 48–72 h after the infection, as previously reported [26]. Macroscopic currents were recorded with the whole cell configuration of the patch-clamp technique, with an Axopatch 1D (Axon Instruments, Inc.). The currents were filtered Y-27632 manufacturer at 5 kHz and sampled every 100 μs with a DigiData 1200 interface (Axon Instruments, Inc.). Electrodes were pulled from borosilicate glass (KIMAX 51) to

a 1–1.5 MΩ resistance. 80% of the series resistance was electronically compensated. The holding potential used throughout the work was −90 mV. The recording solutions were: external bath (in mM): 145 NaCl, 10 Ca2Cl, buffered with 10 HEPES-Na at pH 7.2; internal pipette solution (in mM): 90 KF, 30 KCl, 10 EGTA, buffered with 10 HEPES-K at pH 7.2. Lymphocyte separation: Kv1.3 currents were measured in human peripheral T lymphocytes. Heparinized human peripheral venous blood was obtained from healthy volunteers. Mononuclear cells were separated by ADP ribosylation factor Ficoll–Hypaque density gradient centrifugation. Collected cells were washed twice with Ca2+- and Mg2+-free Hanks’ solution containing 25 mM HEPES buffer, pH 7.4. Cells were cultured in a 5% CO2 incubator at 37 °C in 24-well culture plates in RPMI 1640 medium supplemented with 10% fetal calf serum (Sigma–Aldrich Kft, Budapest, Hungary), 100 μg/mL penicillin, 100 μg/mL streptomycin, and 2 mM L-glutamine at 0.5 × 106/mL density for 3 to 4 days. The culture medium also contained 2.5 or 5 μg/mL phytohemagglutinin A (Sigma–Aldrich Kft, Budapest, Hungary) to increase K+-channel expression [11]. For the measurement of ionic currents standard whole-cell patch-clamp procedures were performed. The bath solution consisted of (in mM) 145 NaCl, 5 KCl, 1 MgCl2, 2.5 CaCl2, 5.5 glucose, and 10 HEPES, pH 7.35, supplemented with 0.

Although sterile nitrogen sources are available, sterile working

Although sterile nitrogen sources are available, sterile working conditions are expensive and delicate [33], [35] and [36]. Also, direct handling of Thermanox© substrates is difficult due their small size and overlapping during cultivation. The cultivation surface has to be as thin as possible to achieve the very high heat transfer rates needed Y-27632 datasheet for vitrification and re-warming. In this work, the consequent advancement of the surface based vitrification technique on modified Thermanox© substrates led to the development of the “twisted vitrification” technique and a respective cultivation and vitrification

device. It is based on a two compartment system with a thin cultivation surface separating the two compartments. It allows the adherent cultivation of hESC colonies and a surrounding feeder layer without constraints to the normal hESC culture. To avoid direct contact with liquid nitrogen learn more of the samples, vitrification and re-warming of the cells was achieved through the cultivation surface. hESC cell colonies cryopreserved by “twisted vitrification “showed almost no colony- or cell-loss caused by the vitrification and thawing process (Fig. 3A–H). Only small areas in the border regions of the cultivation surface showed partial cell- and colony loss, probably due to inhomogeneities in the thickness of the CPA film covering the cells during vitrification (Fig. 3, asterisks). Too much medium (e.g. a meniscus) reduces

the surface to volume ratio and cooling rates are too low for successful vitrification, resulting in ice crystallization. However, the high survival rates imply that cooling rates achieved through the cultivation surface were high enough to permit successful vitrification although there is no independent confirmation of this. Vital residual areas show an increase in the “twisted vitrification” prototype 99% (±1%) compared to vitrification

on modified Thermanox© discs (89% (±11%). This improvement may be the result of reducing the mechanical stress caused by the constant movement of discs through media and liquid nitrogen. Overall recovery and growth rate of the colonies during the first 24 h post-thaw showed no significant difference Reverse transcriptase from non-frozen control colonies. Apoptosis (seen in slow-rate freezing) can be excluded as a source of cell loss after thawing [17]. Post-thaw functionality is not severely affected by “twisted vitrification”. FACS analysis of Tra-1-81 and Oct-4 was not significantly different from a non-frozen control (Fig. 5) and further passage and cultivation of thawed colonies did not result in morphological differences to control colonies (Fig. 3I–L). Although the overall cryopreservation success and post-thawing functionality are very satisfying, the prototype can be improved. The rim of the nitrogen compartment has to be detached to allow high magnification microscopy inside the device. Otherwise, the working distance is too large, so microscopy is not possible.

Destexhe et al , 2001, Freeman, 1979 and Rajagovindan and Ding, 2

Destexhe et al., 2001, Freeman, 1979 and Rajagovindan and Ding, 2010). The basic idea is that an increase in excitation in a task relevant network depends on background/spontaneous activity. The larger this activity is, the larger the gain. This relationship is not linear but obeys a sigmoidal function. The important point for our theory is that we have to consider two functions, one for excitatory and another for inhibitory activity. The latter regulates the local inhibitory gain in the task relevant network in order to optimize SNR. This means that the inhibitory background

activity and the event-related inhibitory gain depend on the excitatory background U0126 price activity and the excitatory event-related gain. As a consequence, in order to increase the SNR in task relevant networks inhibition will increase as excitation increases. These considerations suggest that the P1 reflects the event related change in background inhibitory activity

and allows the following predictions. (i) For task relevant networks, an inverted U-shaped function may be predicted between prestimulus (ongoing) alpha power (reflecting inhibitory background activity) and P1 amplitude (reflecting the event related change in inhibition), provided check details phase locking does not play a specific or interfering role. The inverted U-shaped function simply means that beyond a certain level of background activity, the level of event-related inhibition is reduced

in order to avoid blocking of information processing in task relevant networks. This prediction is very similar to that BCKDHA of Rajagovindan and Ding (2010) with the only but important difference that (according to their view) the inverted U-shaped function (between ongoing alpha and P1 amplitude) is thought to reflect excitatory processes. (ii) For task competing networks, there is no need to control/modify the SNR. Thus, inhibition may be set to a certain level (depending again on excitation), which does not reflect the local inhibitory gain (and the modulation of SNR) but the blocking of information processing. I am grateful for insightful and critical discussions with my colleagues Robert Fellinger and Roman Freunberger. I am also very grateful for critical comments of 3 Reviewers who helped to improve earlier drafts of this article. “
“In the July 1998 issue of Brain Research, we used Figures 5A and 5B which had been already published as Figures 5A and 5B in our previous paper published in Critical Care Medicine 25; 874–879:1997. Although we cited our previous paper as reference 26 in our paper by Taoka, et al., we unintentionally missed the attribution of Figures 5A and 5B in the figure legend of our paper by Taoka, et al. The correct figure legend is as follows: Figure 5.

0; 95% CI 2 8–8 9; P < 01) Delirium alone (OR 2 4; 95% CI

0; 95% CI 2.8–8.9; P < .01). Delirium alone (OR 2.4; 95% CI

1.0–5.7; P = .04) and dementia alone (OR 3.3; 95% CI 2.1–5.3; P < .01) were also significantly associated with institutionalization. Finally, DSD was associated with an almost twofold increase in the risk of mortality (OR 1.8; 95% CI 1.1–2.8; P = .01), whereas an association was not detected between either dementia alone or delirium alone and mortality. No statistically significant association was found for the interaction between delirium and dementia in buy NVP-BKM120 the 3 additional models, including the interaction term delirium and dementia (data not shown). This study specifically investigated the association between DSD and short- and long-term functional outcomes, including the risk of long-term mortality and institutionalization,

in a large population of elderly patients admitted to a rehabilitation setting. DSD was found to be significantly associated with almost a 15-fold increase in the odds of walking dependence at rehabilitation discharge after rehabilitation training and even at 1-year follow-up. Although patients with delirium alone or dementia alone also had higher risks CYC202 of worse functional outcomes at discharge and at 1-year follow-up, these risks appeared lower than in patients with DSD. DSD was also associated with a fivefold increase in the risk of institutionalization and an almost twofold increase in the risk of mortality at 1-year PAK6 follow-up. Previous studies have investigated the role of delirium on functional outcomes but they have not specifically addressed the effect of the combination of delirium and dementia.4 and 21 A first study, carried out in postacute care facilities with a total population of 551 patients, found that persistent or worsening delirium on

admission was significantly associated with poor functional recovery over a 1-week period both in activities of daily living (ADLs) and in instrumental ADLs.21 Only 5% of the sample had a preexisting diagnosis of dementia and no specific analysis addressed the effect of DSD on functional outcomes compared with patients with only delirium or dementia. The study also was limited by the fact that nurses performed delirium assessments without using a specific clinical tool to detect its presence, but used the Minimum Data Set for Post-Acute Care (MDS-PAC). The MDS-based delirium assessment has been recently reported to have limited validity.34 More recently, in a population of 393 elderly patients, Kiely and colleagues4 found that persistence of delirium was a predictor of unsuccessful functional recovery at 2-week and 1-, 3-, and 6-month follow-up. Patients who resolved their delirium by 2 weeks of postacute admission regained 100% of their preadmission functional status, whereas patients for whom delirium never resolved retained less than 50% of their preadmission functional status. Nearly a third of these patients had preexisting dementia.

Selective excitation removes the effect such nuclei since their m

Selective excitation removes the effect such nuclei since their magnetization does not get encoded. However, the effect of nuclei subject of double exchange events is retained; that is, nuclei can be initially Palbociclib manufacturer encoded, get exchanged to the non-encoded site, experience site-selective displacement there and exchange back to the encoded site thereby affecting the diffusional signal decay. In the experiment proposed here, we remove the effect of such processes because we continually suppress magnetization at the “bound” pool. The effect of double exchange events is also suppressed if, as in experiments in protein solutions with selective excitation [41], the non-encoded pool is

much larger than the encoded one and thereby the probability of return is low. For our present system, this is clearly not the case. The efficiency of the exchange suppression on signal attenuation can be

estimated by simulating signal attenuations with one or more filters embedded and comparing those to the attenuations obtained in the classical Stejskal–Tanner expression. For the simulations represented in Fig. 3 and Fig. 4, we used parameters obtained for our agarose/water solution (see below and see Table 1) with Nutlin-3a solubility dmso a diffusion coefficient for water set to Df   = 3 × 10−11 m2 s−1 (and Db   = 0; changing to other values do not significantly change the character of the result). Keeping constant the diffusion time Δ   and increasing the number of T  2-filters (i.e., decreasing τex  ), Atezolizumab mouse the signal attenuation for the proposed pulse sequence is progressively evolving to an attenuation equivalent to obtained from the classical diffusion equation without the presence of exchange ( Fig. 3a). Note that Fig. 3 provide decays with relative intensities and does not highlight the intensity loss given by the e-kfΔe-kfΔ factor in Eq. (10). In Fig. 3b and c, we simulated signal attenuation

for τex ≈ 2/kb and τex ≈ 1/kb, respectively. Clearly, for the τex ≈ 1/kb case, the signal attenuation approaches that without exchange except for the longest diffusion times. Hence, under those conditions the diffusion coefficient extracted by the simple Stejskal–Tanner expression in Eq. (1) should provide accurate Df values. This particular point is further illustrated in Fig. 4, where the apparent diffusion coefficients were extracted by fitting the classical Stejskal–Tanner expression in Eq. (1) to the theoretical signal attenuation curves given by Eq. (8b). For Δ = 20 ms and qmax = 4 × 105 m−1 and with material parameters set as for Fig. 3, the obtained decays were clearly multi-exponential for long τex (>4 ms) or small n (<4), while with more intensive filtering the signal attenuation showed no significant deviation from mono-exponentiality.

1) The reference lists of these included articles were manually

1). The reference lists of these included articles were manually screened, but they did not yield additional studies. After excluding 17 duplications, a total of 21 articles were included for further synthesis.6, 7, 8, 9, 10, 11, 12, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42 and 43 No randomized or nonrandomized, controlled trials were identified. Of the 21 included MS-275 in vitro studies, 9 used a prospective case series design8, 11, 30, 32, 33, 34, 35, 36 and 38; the remaining 12 studies used a retrospective case series approach. Eight studies used MPSs after OLT,6, 7, 8, 9, 10, 11, 12 and 37 3 studies used MPSs after LDLT,41, 42 and 43 whereas 10 studies used SEMSs after OLT

for ABSs. No study using SEMSs after LDLT was identified. The 5 most important criteria in the Centre for Reviews and Dissemination quality assessment checklist primarily addressed selection bias (eligibility criteria, consecutive cases), attrition bias (patient follow-up), and detection bias (prospective design).28 In the studies that we identified, patient inclusion and exclusion criteria were clearly reported in all but 2 studies.31 and 35 Consecutive enrollment of cases was clearly reported in only 4 studies.32, 34, 35 and 38 All 21 studies followed 100% of the included patients. Clear descriptions of study design with inclusion and exclusion Selleckchem Buparlisib criteria were provided in 13 of the 21 studies.6, 7, 8, 9, 10, 11, 12, 30, 37, 39, 40, 41 and 43

None of the studies met all 5 criteria, thus reaching a quality rating of “poor.” Nine studies met 4 of 5 criteria,8, 9, 11, 30, 32, 34, 35, 38 and 43 11 studies met 3 of 5 criteria,6, 7, 10, 12, 33, 36, 37, 39, 40, 41 and 42 and 1 study met 2 of 5 criteria.31 Patient baseline characteristics and outcomes are summarized in Table 1 (OLT), Table 2 (LDLT) for MPSs, and Table 3 for SEMS studies. There

was significant heterogeneity in primary outcomes, such as stricture resolution rates, stent removability, mafosfamide and stent patency rates. The stent protocols, including the diameter of PSs, diameter of the dilating balloon used, number of side-by-side PSs placed, number of BDs or stent exchanges performed, the interval between stent exchanges, overall duration of stent placement, and stent-free follow-up, varied significantly in MPS studies. There was also heterogeneity in the types of SEMSs used, the use of BD or MPSs and duration before SEMS placement, overall stent duration, and stent-free follow-up in SEMS studies. The various stent protocols are summarized in Table 4. Eight studies used MPSs to treat a total of 440 OLT patients.6, 7, 8, 9, 10, 11, 12 and 37 Overall technical success rates were high, ranging from 92% to 100%. The stent exchange interval was approximately 3 months in most studies, except for that in the study by Morelli et al,8 who used an exchange interval of 2 weeks. The mean or median number of stents per ERCP was between 2 and 3.