Evaluation of biodegradable paclitaxel-eluting nanofibre-covered metal stents for the treatment of benign cardia stricture in an experimental model

BACKGROUND

Benign strictures at the cardia are troublesome for patients and often require repeated endoscopic treatments. Paclitaxel can reduce fibrosis. This study evaluated a biodegradable paclitaxel-eluting nanofibre-covered metal stent for the treatment of benign cardia stricture in vitro and in vivo.

METHODS

Drug release was investigated in vitro at pH 7·4 and 4·0. Eighty dogs were divided randomly into four groups (each n = 20): controls (no stent), bare stent (retained for 1 week), and two drug-eluting stent (DES) groups with retention for either 1 week (DES-1w) or 4 weeks (DES-4w). Lower oesophageal sphincter pressure (LOSP) and 5-min barium height (5-mBH) were assessed before, immediately after stent deployment, at 1 week, and 1, 3 and 6 months later. Five dogs in each group were killed for histological examination at each follow-up point.

RESULTS

Stent migration rates were similar (0 bare stent versus 2 DES; P = 0·548). The percentage and amount of paclitaxel released in vitro was higher at pH 4·0 than at pH 7·4. After 6 months, LOSP and 5-mBH were both improved in the DES-1w (P = 0·004 and P = 0·049) and DES-4w (both P < 0·001) groups compared with the bare-stent group, with better relief when the stent was retained for 4 weeks (P = 0·004 and P = 0·007). The DES was associated with a reduced peak inflammatory reaction and less scar formation compared with bare stents, especially when inserted for 4 weeks.

CONCLUSION

The DES was more effective for the treatment of benign cardia stricture than bare stents in a canine model. Retention of the DES for 4 weeks led to a better clinical and pathological outcome than 1 week.

Observation of two new N* resonances in the decay ψ(3686)→ppπ0

Based on 106×10(6)ψ(3686) events collected with the BESIII detector at the BEPCII facility, a partial wave analysis of ψ(3686)→ppπ0 is performed. The branching fraction of this channel has been determined to be B(ψ(3686)→ppπ0)=(1.65±0.03±0.15)×10(-4). In this decay, 7 N* intermediate resonances are observed. Among these, two new resonances, N(2300) and N(2570) are significant, one 1/2+ resonance with a mass of 2300(-30-0)(+40+109)  MeV/c2 and width of 340(-30-58)(+30+110)  MeV/c2, and one 5/2- resonance with a mass of 2570(-10-10)(+19+34)  MeV/c2 and width of 250(-24-21)(+14+69)  MeV/c2. For the remaining 5 N* intermediate resonances [N(1440), N(1520), N(1535), N(1650) and N(1720)], the analysis yields mass and width values that are consistent with those from established resonances.

Responses of brain and behavior to changing day-length in the diurnal grass rat (Arvicanthis niloticus)

Seasonal affective disorder (SAD) is a major depressive disorder that recurs in the fall and winter when day-length gets short. It is well accepted that day-length is encoded by the principal circadian clock located in the suprachiasmatic nucleus (SCN), but very little is known about day-length encoding in diurnal mammals. The present study utilized the grass rat, Arvicanthis niloticus, to investigate how the circadian system responds to photoperiodic changes in a diurnal mammal that shows day-length-dependent mood changes. The animals were initially housed in equatorial day-length (12h, EP) followed by either long (16h, LP) or short (8h, SP) photoperiods. The LP animals showed an expansion of the peak phase of the PER1 and PER2 rhythm in the SCN as well as an extended behavioral active phase. In contrast, the SP animals did not show any compression of their active phase nor a change in the peak duration of PER1 or PER2 expression, compared to those in EP. The results suggest that the circadian system in the diurnal grass rats is less responsive when day-length gets short compared to when it gets longer. The depression-like behaviors were assessed using sweet solution preference (SSP) and forced swimming test (FST). Animals in the SP group showed decreased SSP and increased immobility time in FST as compared to the EP group, suggesting a depressive phenotype. The present study serves as the first step toward exploring the role that the circadian system plays in SAD using a diurnal rodent model.

Acute behavioral responses to light and darkness in nocturnal Mus musculus and diurnal Arvicanthis niloticus

The term masking refers to immediate responses to stimuli that override the influence of the circadian timekeeping system on behavior and physiology. Masking by light and darkness plays an important role in shaping an organism's daily pattern of activity. Nocturnal animals generally become more active in response to darkness (positive masking) and less active in response to light (negative masking), and diurnal animals generally have opposite patterns of response. These responses can vary as a function of light intensity as well as time of day. Few studies have directly compared masking in diurnal and nocturnal species, and none have compared rhythms in masking behavior of diurnal and nocturnal species. Here, we assessed masking in nocturnal mice (Mus musculus) and diurnal grass rats (Arvicanthis niloticus). In the first experiment, animals were housed in a 12:12 light-dark (LD) cycle, with dark or light pulses presented at 6 Zeitgeber times (ZTs; with ZT0 = lights on). Light pulses during the dark phase produced negative masking in nocturnal mice but only at ZT14, whereas light pulses resulted in positive masking in diurnal grass rats across the dark phase. In both species, dark pulses had no effect on behavior. In the 2nd experiment, animals were kept in constant darkness or constant light and were presented with light or dark pulses, respectively, at 6 circadian times (CTs). CT0 corresponded to ZT0 of the preceding LD cycle. Rhythms in masking responses to light differed between species; responses were evident at all CTs in grass rats but only at CT14 in mice. Responses to darkness were observed only in mice, in which there was a significant increase in activity at CT 22. In the 3rd experiment, animals were kept on a 3.5:3.5-h LD cycle. Surprisingly, masking was evident only in grass rats. In mice, levels of activity during the light and dark phases of the 7-h cycle did not differ, even though the same animals had responded to discrete photic stimuli in the first 2 experiments. The results of the 3 experiments are discussed in terms of their methodological implications and for the insight they offer into the mechanisms and evolution of diurnality.

Surface-emission studies in a high-field RF gun based on measurements of field emission and Schottky-enabled photoemission

We report on investigations into the fundamental surface emission parameters, the geometric field enhancement factor (β) and the work function (φ), by making both field emission and Schottky-enabled photoemission measurements. The measurements were performed on a copper surface in the Tsinghua University S-band RF gun in two separate experiments. Fitting our data to the models for each experiment indicate that the traditionally assumed high value of β(≈50-500) does not provide a plausible explanation of the data, but incorporating a low value of φ at some sites does. In addition, direct measurements of the surface conducted after the experiment show that β is on the order of a few, consistent with our understanding of the electron emission measurements. Thus we conclude that the dominant source of electron emission in high gradient RF cavities is due to low φ sites, as opposed to the conventionally assumed high β sites. The origin of low φ at these sites is unclear and should be the subject of further investigation.

Evidence for the direct two-photon transition from ψ(3686) to J/ψ

The two-photon transition ψ(3686)→γγJ/ψ is studied in a sample of 1.06×10(8) ψ(3686) decays collected by the BESIII detector. The branching fraction is measured to be (3.1±0.6(stat)(-1.0)(+0.8)(syst))×10(-4) using J/ψ→e(+)e(-) and J/ψ→μ(+)μ(-) decays, and its upper limit is estimated to be 4.5×10(-4) at the 90% confidence level. This work represents the first measurement of a two-photon transition among charmonium states. The orientation of the ψ(3686) decay plane and the J/ψ polarization in this decay are also studied. In addition, the product branching fractions of sequential E1 transitions ψ(3686)→γχ(cJ) and χ(cJ)→γJ/ψ(J=0,1,2) are reported.

Association between HLA-DRB1 polymorphisms and pemphigus vulgaris: a meta-analysis

Summary

Background Several studies have reported that HLA-DRB1 may be correlated with pemphigus vulgaris (PV), but most have been based on small samples and the results remain inconsistent and unclear.

Objectives To investigate the correlation between DRB1 and PV by a meta-analysis of case–control/nonfamily studies.

Methods PubMed, Wiley Online Library, ScienceDirect, Google Scholar, Cochrane Library, Chinese National Knowledge Infrastructure and Wanfang databases were searched for studies including: (i) ‘pemphigus’; and (ii) ‘human leukocyte antigen’, ‘HLA’, ‘major histocompatibility complex’, ‘MHC’ or ‘DRB1’. Eighteen selected studies were used in meta-analyses to evaluate DRB1 alleles and phenotypes by calculating the respective odds ratios (ORs) and 95% confidence intervals (CIs). Stratified meta-analyses and meta-regression analysis were also conducted.

Results The frequencies of three genotypes (allele and phenotype, respectively) were significantly increased in PV: DRB1*04 [P-value for comparability (Pc) < 0·00001, OR 3·61, 95% CI 2·28–5·71; Pc = 0·0002, OR 4·14, 95% CI 1·98–8·65], DRB1*08 (Pc = 0·03, OR 2·25, 95% CI 1·07–4·70; Pc = 0·0003, OR 2·46, 95% CI 1·51–4·01) and DRB1*14 (Pc < 0·00001, OR 6·47, 95% CI 4·52–9·26; Pc < 0·00001, OR 9·68, 95% CI 4·47–20·98). Three others (allele and phenotype, respectively) were significantly decreased in PV: DRB1*03 (Pc < 0·00001, OR 0·28, 95% CI 0·19–0·41; Pc = 0·0001, OR 0·25, 95% CI 0·12–0·51), DRB1*07 (Pc = 0·004, OR 0·45, 95% CI 0·26–0·78; Pc = 0·0002, OR 0·27, 95% CI 0·14–0·54) and DRB1*15 (Pc = 0·001, OR 0·35, 95% CI 0·18–0·66; Pc = 0·002, OR 0·32, 95% CI 0·16–0·65). Ethnicity partially explained the heterogeneity of DRB1*07, DRB1*08 and DRB1*14 phenotypes.

Conclusions Our findings suggest that DRB1*04, DRB1*08 and DRB1*14 are statistically significant susceptibility factors for PV. Conversely, DRB1*03, DRB1*07 and DRB1*15 may be negatively associated with PV. Specific HLA-DRB1 types may influence the susceptibility or resistance to PV, which needs further investigations.

Vascular endothelial growth factor-induced expression of its receptors and activation of the MAPK signaling pathway during ovine oocyte maturation in vitro

The vascular endothelial growth factor (VEGF) has beneficial effects on ovine oocytes during in vitro maturation and their subsequent early embryonic development, but the biochemical pathway underlying this effect has not been elucidated. Therefore, the focus of the present study was to investigate the activation of the mitogen-activated protein kinase (MAPK) pathway in response to the addition of VEGF to the maturation medium, and to study the subcellular localization of VEGF and its receptors during ovine oocyte maturation. We concluded that: (1) VEGF mainly localized in the cytoplasm, whereas its receptors, fms-tyrosine kinase-1 and kinase domain region (KDR), were localized on the plasma membrane of oocytes; (2) the addition of 5 ng/mL VEGF increased the percentage of oocytes with extruded first polar bodies (50.9 ± 2.2% vs. 34.6 ± 2.9%; treatment vs. control, respectively; P < 0.01) and the rate of oocytes competent to undergo nuclear maturation (70.6 ± 0.9% vs. 62.9 ± 1.9%, P < 0.01); and (3) as the expression of VEGF, fms-tyrosine kinase-1, and KDR increased after supplementation with 5 ng/mL, expression of VEGF, mitogen-activated protein kinase kinase (MEK), and MAPK mRNA, as well as MAPK phosphorylation, were stimulated in a time-dependent manner. We inferred that, in a paracrine manner, exogenous VEGF bound to KDR, its main receptor, and then activated the MAPK signaling pathway, which promoted maturation of ovine oocytes. However, the VEGF system also had an autocrine regulatory loop that contributed to creating an environment optimal for oocyte maturation.

Prevalence of the HPA-18w to -21w alleles in the Chinese Han population

Recently, four new platelet alloantigen (HPA) systems HPA-18w to-21w were identified. However, genotyping for HPA-18w to -21w alleles was rarely reported. Here, we established a polymerase chain reaction sequence-based typing (PCR-SBT) method and investigated the distribution of HPA-18w to -21w alleles in the Chinese Han population. The specific primers of HPA-18w, -19w, -20w and -21w were designed, and the PCR products were bidirectionally sequenced. 855 randomly selected platelet donors were genotyped for HPA-18w to -21w with the PCR-SBT method. The results showed that all individuals were monomorphic for HPA-18w to HPA-20w with a/a homozygous frequency of 1.0 and absence of HPA-18bw to -20bw alleles. The frequencies of the HPA-21a/21a and HPA-21a/21b genotypes were 0.981(839/855) and 0.019(16/855), respectively. Seven mutations were confirmed on sequenced region separate from HPA polymorphisms, including ITGA2 (IVS17+48G>A and IVS17+72G>A), ITGA2B (IVS19-26C>G) and ITGB3 (IVS4+234C>T, IVS11-19 T>C, IVS11-104T>C and GT repeats from IVS11-131 to IVS11-109). These data will provide useful information for diagnosis, prevention and treatment of alloimmune thrombocytopaenia.

First observation of the M1 transition ψ(3686)→γη(c)(2S)

Using a sample of 106×10(6) ψ(3686) events collected with the BESIII detector at the BEPCII storage ring, we have made the first measurement of the M1 transition between the radially excited charmonium S-wave spin-triplet and the radially excited S-wave spin-singlet states: ψ(3686)→γη(c)(2S). Analyses of the processes ψ(3686)→γη(c)(2S) with η(c)(2S)→K(S)(0)K(±)π(∓) and K(+)K(-)π(0) give an η(c)(2S) signal with a statistical significance of greater than 10 standard deviations under a wide range of assumptions about the signal and background properties. The data are used to obtain measurements of the η(c)(2S) mass (M(η(c)(2S))=3637.6±2.9(stat)±1.6(syst) MeV/c(2)), width (Γ(η(c)(2S))=16.9±6.4(stat)±4.8(syst) MeV), and the product branching-fraction (B(ψ(3686)→γη(c)(2S))×B(η(c)(2S)→KKπ)=(1.30±0.20(stat)±0.30(syst))×10(-5)). Combining our result with a BABAR measurement of B(η(c)(2S)→KKπ), we find the branching fraction of the M1 transition to be B(ψ(3686)→γη(c)(2S))=(6.8±1.1(stat)±4.5(syst))×10(-4).

One-hour upright posture is an ideal position for serum aldosterone concentration and plasma renin activity measuring on primary aldosteronism screening

The serum aldosterone concentration (SAC) to plasma renin activity (PRA) ratio (ARR) is considered a useful screening test in the differential diagnosis of essential hypertension (EH) and primary aldosteronism (PA). The purpose of this study is to investigate the variation of ARR and compare the screening efficiency of it under different postures.37 patients with PA and 92 patients with EH were recruited in this study. Blood was sampled for measuring SAC and PRA under conditions of overnight recumbency, keeping upright posture for 1 h, 2 h and 4 h. The variation and screening efficiency of ARR under these conditions were compared according to repeated measured ANOVA and ROC curve analysis.In the EH group, ARR measured under recumbency posture was higher than those measured under keeping upright posture for 1 h and 2 h. In the PA group, there is no statistical difference for ARR between any 2 postures. AUCs of ARR measured under 4 conditions were 0.976, 0.995, 0.988, and 0.974 respectively. Cutoff values were ranging from 24.75 ng/dl per ng/ml/h under keeping upright for 2 h to 69.19 ng/dl per ng/ml/h under overnight recumbercy. ARR measured under keeping upright posture for 1 h produced the best characteristic of screening efficiency.Keeping upright posture for 1 h was the ideal position for ARR measuring and using a cutoff value of 35.90 ng/dl per ng/ml/h will have a sensitivity and specificity of 100.00% and 92.30% respectively.

Orexinergic signaling mediates light-induced neuronal activation in the dorsal raphe nucleus

Seasonal affective disorder (SAD), a major depressive disorder recurring in the fall and winter, is caused by the reduction of light in the environment, and its depressive symptoms can be alleviated by bright light therapy. Both circadian and monoaminergic systems have been implicated in the etiology of SAD. However, the underlying neural pathways through which light regulates mood are not well understood. The present study utilized a diurnal rodent model, Arvicanthis niloticus, to explore the neural pathways mediating the effects of light on brain regions involved in mood regulation. Animals kept in constant darkness received light exposure in early subjective day, the time when light therapy is usually applied. The time course of neural activity following light exposure was assessed using Fos protein as a marker in the following brain regions/cells: the suprachiasmatic nucleus (SCN), orexin neurons in the perifornical-lateral hypothalamic area (PF-LHA) and the dorsal raphe nucleus (DRN). A light-induced increase in Fos expression was observed in orexin neurons and the DRN, but not in the SCN. As the DRN is densely innervated by orexinergic inputs, the involvement of orexinergic signaling in mediating the effects of light on the DRN was tested in the second experiment. The animals were injected with the selective orexin receptor type 1 (OXR1) antagonist SB-334867 prior to the light exposure. The treatment of SB-334867 significantly inhibited the Fos induction in the DRN. The results collectively point to the role of orexin neurons in mediating the effects of light on the mood-regulating monoaminergic areas, suggesting an orexinergic pathway that underlies light-dependent mood fluctuation and the beneficial effects of light therapy.

Measurements of the mass and width of the η(c) using the decay ψ(3686)→γη(c)

The mass and width of the lowest-lying S-wave spin singlet charmonium state, the η(c), are measured using a data sample of 1.06×10(8) ψ(3686) decays collected with the BESIII detector at the BEPCII storage ring. We use a model that incorporates full interference between the signal reaction, ψ(3686)→γη(c), and a nonresonant radiative background to describe the line shape of the η(c) successfully. We measure the η(c) mass to be 2984.3±0.6±0.6 MeV/c(2) and the total width to be 32.0±1.2±1.0 MeV, where the first errors are statistical and the second are systematic.

First observation of η(1405) decays into f(0)(980)π0

The decays J/ψ → γ π+ π- π0 and J/ψ → γ π0 π0 π0 are analyzed using a sample of 225×10(6) J/ψ events collected with the BESIII detector. The decay of η(1405) → f(0)(980)π0 with a large isospin violation is observed for the first time. The width of the f(0)(980) observed in the dipion mass spectra is anomalously narrower than the world average. Decay rates for three-pion decays of the η' are also measured precisely.

Spin-parity analysis of pp¯ mass threshold structure in J/ψ and ψ(3686) radiative decays

A partial wave analysis of the pp¯ mass-threshold enhancement in the reaction J/ψ→γpp¯ is used to determine its J(PC) quantum numbers to be 0(-+), its peak mass to be below threshold at M=1832(-5)(+19)(stat)(-17)(+18)(syst)±19(model) MeV/c(2), and its total width to be Γ<76 MeV/c(2) at the 90% C.L. The product of branching ratios is measured to be BR[J/ψ→γX(pp¯)]BR[X(pp¯)→pp¯]=[9.0(-1.1)(+0.4)(stat)(-5.0)(+1.5)(syst)±2.3(model)]×10(-5). A similar analysis performed on ψ(3686)→γpp¯ decays shows, for the first time, the presence of a corresponding enhancement with a production rate relative to that for J/ψ decays of R=[5.08(-0.45)(+0.71)(stat)(-3.58)(+0.67)(syst)±0.12(model)]%.