Thermoacoustic waves along the critical isochore

Near the liquid-gas critical point, thermal disturbances can generate sounds. We study the acoustic emission over four decades of reduced temperatures [defined as ɛ=(T-T(c))/T(c), with T(c) the critical temperature] along the critical isochore, under linear and nonlinear temperature perturbations, respectively. We identify various thermoacoustic behaviors by numerically solving the governing equations. It is shown that a homogeneous thermoacoustic-wave pattern dominates in the linear case, largely independent of ɛ; whereas under the nonlinear perturbation, variation in ɛ could lead to severe wavefront deformation. The strong nonlinear effect is found to be of a transient nature because, in due time, both cases tend to converge in terms of the energy yield of the adiabatic process.

Radiation-induced intercellular signaling mediated by cytochrome-c via a p53-dependent pathway in hepatoma cells

The tumor suppressor p53 has a crucial role in cellular response to DNA damage caused by ionizing radiation, but it is still unclear whether p53 can modulate radiation-induced bystander effects (RIBE). In the present work, three different hepatoma cell lines, namely HepG2 (wild p53), PLC/PRF/5 (mutation p53) and Hep3B (p53 null), were irradiated with γ-rays and then co-cultured with normal Chang liver cell (wild p53) in order to elucidate the mechanisms of RIBE. Results showed that the radiosensitivity of HepG2 cells was higher than that of PLC/PRF/5 and Hep3B cells. Only irradiated HepG2 cells, rather than irradiated PLC/PRF/5 or Hep3B cells, could induce bystander effect of micronuclei (MN) formation in the neighboring Chang liver cells. When HepG2 cells were treated with 20 μM pifithrin-α, an inhibitor of p53 function, or 5 μM cyclosporin A (CsA), an inhibitor of cytochrome-c release from mitochondria, the MN induction in bystander Chang liver cells was diminished. In fact, it was found that after irradiation, cytochrome-c was released from mitochondria into the cytoplasm only in HepG2 cells in a p53-dependent manner, but not in PLC/PRF/5 and Hep3B cells. Interestingly, when 50 μg/ml exogenous cytochrome-c was added into cell co-culture medium, RIBE was significantly triggered by irradiated PLC/PRF/5 and Hep3B cells, which previously failed to provoke a bystander effect. In addition, this exogenous cytochrome-c also partly recovered the RIBE induced by irradiated HepG2 cells even with CsA treatment. Our results provide new evidence that the RIBE can be modulated by the p53 status of irradiated hepatoma cells and that a p53-dependent release of cytochrome-c may be involved in the RIBE.

Do preoperative factors predict subsequent diagnosis of Crohn's disease after ileal pouch-anal anastomosis for ulcerative or indeterminate colitis?

AIM

The aim of this study was to determine preoperative clinical factors associated with subsequent diagnosis revision to Crohn's disease (CD) following total proctocolectomy with ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC) or indeterminate colitis (IC) patients.

METHOD

Presumed UC and IC patients undergoing IPAA from a large single-institution prospective database with change of diagnosis to CD were identified and compared with patients without diagnosis change.

RESULTS

A total of 2814 patients (47% male, median age 37 years) with presumed UC (85%) or IC (15%) underwent primary IPAA. At a median follow up of 9.6 years, 184 (7%) had the diagnosis revised to CD from histopathological examination of the colectomy specimen immediately in 97 (53%) or at a median interval of 36 months in 87 (47%). CD and UC/IC patients had had a similar operative technique, length of stay and 30-day morbidity. The postoperative CD diagnosis was associated with a preoperative diagnosis of IC (P < 0.0001) and perianal fistula (P = 0.002). Patients with a delayed diagnosis of CD were associated with a 3-stage procedure (P < 0.0001, OR = 2.8) (95% CI = 1.8-4.4), colonic stricture (P = 0.04, OR = 2.9 [95% CI = 1.1-7.4]), perianal fistula (P = 0.02, OR = 2.9 [95% CI = 1.2-7.2]), oral ulceration (P = 0.009, OR = 3.8 [95% CI = 1.2-9.6]) and younger age (P < 0.0001, OR = 0.048 [95% CI = 0.011-0.19]).

CONCLUSION

A few patients having IPAA for presumed UC/IC were subsequently diagnosed to have CD which was associated with perianal fistula and the diagnosis of postoperative preoperative IC. The delayed diagnosis of CD was associated with a three-stage procedure, colorectal stricture, anal fissure, mouth ulceration and younger age.

The Treg/Th17 imbalance in patients with idiopathic dilated cardiomyopathy

To assess whether Treg/Th17 balance was broken in patients with idiopathic dilated cardiomyopathy (DCM). We studied 25 patients who were diagnosed as idiopathic DCM (18 men and seven women, mean age 35.6 +/- 5.2) and 25 normal persons (18 men and seven women, mean age 33.8 +/- 4.9). Then, we detected Treg/Th17 functions on different levels including cell frequencies, related cytokine secretion and key transcription factors in patients with idiopathic DCM and controls. The results demonstrated that patients with idiopathic DCM revealed significant increase in peripheral Th17 number, Th17-related cytokines (IL-17, IL-6, IL-23) and transcription factor (RORgammat) levels and obvious decrease in Treg number, Treg-related cytokines (TGF-beta1 and IL-10) and transcription factor (Foxp3) levels when compared to normal persons. Results indicated that Treg/Th17 functional imbalance existed in patients with idiopathic DCM, suggesting a potential role for Treg/Th17 imbalance in the development of idiopathic DCM.

Novel sulfated glucomannan-barium-alginate microcapsules in islet transplantation: significantly decreased the secretion of monocyte chemotactic protein 1 and improved the activity of islet in rats

The sulfated glucomannan can be used to filter the heparin-binding properties of cytokines. In this study, novel sulfated glucomannan-barium-alginate (SGA) microcapsules were prepared to encapsulate islets with barium-alginate (ABa) and calcium alginate-poly-l-lysine (APA) microcapsules as controls. SD rat islets were purified as donor cells to Lewis rats that had been treated with streptozotocin. Intraperitoneal transplantation was performed with about 3000 islet equivalent (IEQ) rat. At week three after transplantation, the concentrations of monocyte chemotactic protein-1 (MCP-1), interleukin (IL)-1 beta, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha in intraperitoneal fluid were determined using ELISA. At week 8, the islet cell mass in the abdominal microcapsules was excised to test insulin release. The EB-FDA fluorescence staining method was used to observe the functional activity of the islet cells. Compared with ABa and APA microcapsules, SGA microcapsules showed significantly decreased MCP-1 secretion by beta-cells. Also, the concentrations of cytokines IL-1beta, IFN-gamma, and TNF-alpha were decreased significantly. The activity of the transplanted islets was significantly improved in SGA microcapsules, which shielded against cytokines better than ABa or APA microcapsules and may serve as novel method.

Natural history of Crohn's disease in patients who underwent intentional restorative proctocolectomy with ileal pouch-anal anastomosis

BACKGROUND

Crohn's disease is generally considered a relative contraindication for restorative proctocolectomy with ileal pouch anastomosis (IPAA). The natural history of IPAA in these patients has not well been defined.

AIM

To evaluate the natural history of IPAA in patients with a well-defined preoperative Crohn's disease.

METHODS

All patients from the Pouchitis Clinic who had a preoperative diagnosis of Crohn's disease were screened and 11 patients met the inclusion criteria. The control group (with a 1:4 ratio) consisted of IPAA patients with a preoperative diagnosis of UC.

RESULTS

During the follow-up period of 5.0 years, 7 of 11 (63.6%) with a preoperative diagnosis of Crohn's disease developed Crohn's disease of the pouch. Crohn's disease of the pouch developed 0.2-15 years after ileostomy closure. The remaining four patients with a preoperative diagnosis of Crohn's disease did not demonstrate signs of Crohn's disease in 2, 11, 11 and 24 years after pouch surgery, respectively.

CONCLUSIONS

Post-operative development of Crohn's disease of the pouch was common in patients with a preoperative diagnosis of Crohn's disease who underwent IPAA. Long-term medical therapy was often required. Large multi-centre studies are warranted to delineate further the natural history of the disease, before Crohn's disease is considered an indication for IPAA.

Pyloric gland metaplasia and pouchitis in patients with ileal pouch-anal anastomoses

BACKGROUND

Diagnosis and management of chronic antibiotic-refractory pouchitis and Crohn's disease of the pouch can be challenging. Pyloric gland metaplasia is a histological feature indicative of chronic mucosal inflammation. Its value in diagnosis and prognosis of pouch disorders has not been investigated.

AIM

To assess the prevalence, diagnostic and prognostic value, and risk factors of pyloric gland metaplasia in pouch patients.

METHODS

Patients were identified from our prospectively maintained Pouchitis Database. Pouch biopsy specimens were re-reviewed for pyloric gland metaplasia and other histological features. Two cohorts of patients were studied: a historical cohort (n = 111) and the second, a validation cohort (n = 100). Univariate and multivariate analyses were performed to assess risk factors for pyloric gland metaplasia.

RESULTS

The prevalence of pyloric gland metaplasia in the historical cohort and validation cohort was 45 (40.1%) and 24 (24.0%), respectively. The sensitivity and specificity of pyloric gland metaplasia for the diagnosis of chronic antibiotic-refractory pouchitis or Crohn's disease were 70.7% and 92.5%, respectively, for the first cohort and 39.0% and 86.4%, respectively, for the 2nd validation cohort. In multivariate analysis of the first cohort, patients with refractory pouchitis or Crohn's disease were 28 times (95% CI, 7.3-107.1) more likely to have pyloric gland metaplasia than those with a normal pouch or irritable pouch syndrome. The factor of refractory pouchitis or Crohn's disease remained in the model for the 2nd validation cohort with odds ratio of 4.58 (95% CI, 1.6-13.4).

CONCLUSIONS

Pyloric gland metaplasia is associated with diagnosis of chronic antibiotic-refractory pouchitis or Crohn's disease of the pouch and appears to be a specific marker for both disease entities.

Contrasting spin dynamics between underdoped and overdoped Ba(Fe1-xCox)2As2

We report the first NMR investigation of spin dynamics in the overdoped nonsuperconducting regime of Ba(Fe1-xCox)2As2 up to x=0.26. We demonstrate that the absence of interband transitions with large momentum transfer Q{AF} approximately (pi/a,0) between the hole and electron Fermi surfaces results in complete suppression of antiferromagnetic spin fluctuations for x greater than or approximately 0.15. Our experimental results provide direct evidence for a correlation between T{c} and the strength of Q{AF} antiferromagnetic spin fluctuations.

Clinical features of ileal pouch-anal anastomosis in African American patients with underlying ulcerative colitis

BACKGROUND

The prevalence of inflammatory bowel disease in African Americans appears to be increasing. The data on differences in disease behavior and severity between the races have been conflicting.

AIM

To evaluate the effect of race on outcome and natural history of patients with ileal pouch-anal anastomosis.

METHODS

All African American patients with underlying ulcerative colitis and ileal pouch-anal anastomosis who were seen in our subspecialty Pouchitis Clinic from 2002 to 2008 were included. The control group consisted of Caucasian patients with ulcerative colitis and ileal pouch-anal anastomosis who were randomly selected from the same Pouch Registry at a ratio of 4:1. We compared pouch failure, Crohn's disease of the pouch, and chronic pouchitis rates, as well as other 23 demographic and clinical variables between African American and Caucasian patients.

RESULTS

A total of 12 African American patients and 48 Caucasian patients were evaluated in this case-control study. There were no significant differences in the frequency of pouch failure, Crohn's disease of the pouch, or chronic pouchitis between the African American and Caucasian groups. However, African American patients were found to have a significantly shorter duration of inflammatory bowel disease (11.5 years vs. 17.0 years, P = 0.024) as well as significantly shorter duration of pouch (1.5 years vs. 4 years, P = 0.02). African Americans were also less likely to have pancolitis at the time of colectomy (83% vs. 100%, P = 0.037).

CONCLUSIONS

While there were no significant differences in pouch outcomes between the races, African American patients appeared to have more left-sided colitis at the time of colectomy, with a shorter duration of inflammatory bowel and ileal pouch. This finding suggests that the natural history of ulcerative colitis and disease course before and after restorative proctocolectomy may be different between these racial groups.

Endoscopic treatment for pill bezoars after continent ileostomy

Difficulty intubation is the most common long-term complication after continent ileostomy, which can be associated with nipple valve slippage, parastomal hernia, stenosis. Diagnosis and management of a patient with nipple valve stricture and partial bowel obstruction associated with dietary supplement retention in the pouch reservoir is described. A 50-year-old female patient with ulcerative colitis and a 15-year history of continent ileostomy after total proctocolectomy reported 5-week symptoms of abdominal pain and difficulty in intubating the pouch. Pill bezoar composed of dietary supplement was found in diagnostic pouch endoscopy. Therapeutic pouch endoscopy was performed with balloon dilation of a nipple valve stenosis and retrieval of 224 dietary supplement tablets. Pill bezoar in the pouch is rare. However, patients with continent ileostomy should be advised to avoid taking hard-to-dissolve foods and medications.

Thermoacoustic wave propagation and reflection near the liquid-gas critical point

We study the thermoacoustic wave propagation and reflection near the liquid-gas critical point. Specifically, we perform a numerical investigation of the acoustic responses in a near-critical fluid to thermal perturbations based on the same setup of a recent ultrasensitive interferometry measurement in CO2 [Y. Miura, Phys. Rev. E 74, 010101(R) (2006)]. The numerical results agree well with the experimental data. Different features regarding the reflection pattern of thermoacoustic waves near the critical point under pulse perturbations are revealed by the proper inclusion of the critically diverging bulk viscosity.

A new low drift integrator system for the Experiment Advanced Superconductor Tokamak

A new type of the integrator system with the low drift characteristic has been developed to accommodate the long pulse plasma discharges on Experiment Advanced Superconductor Tokamak (EAST). The integrator system is composed of the Ethernet control module and the integral module which includes one integrator circuit, followed by two isolation circuits and two program-controlled amplifier circuits. It compensates automatically integration drift and is applied in real-time control. The performance test and the experimental results in plasma discharges show that the developed integrator system can meet the requirements of plasma control on the accuracy and noise level of the integrator in long pulse discharges.

Administration of adalimumab in the treatment of Crohn's disease of the ileal pouch

BACKGROUND

Crohn's disease (CD) of the pouch can develop in patients with ileal pouch-anal anastomosis (IPAA). Scant data are available on the treatment of this disease entity.

AIM

To evaluate efficacy and safety of adalimumab in treating CD of the ileal pouch.

METHODS

From June 2007 to June 2008, 17 IPAA patients with inflammatory (n = 10), fibrostenotic (n = 2) or fistulizing (n = 5) CD of the pouch treated with adalimumab were evaluated. Inclusion criteria were CD of the pouch who failed medical therapy and were otherwise qualified for permanent pouch diversion or excision. All qualified patients received the standard dosing regimen of subcutaneous injection adalimumab (160 mg at week 0, 80 mg at week 1, and 40 mg every other week thereafter). Complete clinical response was defined as resolution of symptoms. Partial clinical response was defined as improvement in symptoms. Endoscopic inflammation before and after therapy was recorded, using the Pouchitis Disease Activity Index (PDAI) endoscopy subscores.

RESULTS

The median age was 36 years with 12 patients (70.6%) being male. At 4 weeks, seven patients (41.2%) had a complete symptom response and 6 (35.3%) had a partial response. There was also a significant improvement in the PDAI endoscopy subscores at week 4 (P < 0.05). At the last follow-up (median of 8 weeks), eight patients (47.1%) had a complete symptom response and 4 (23.5%) had a partial response. Four patients (23.6%) developed adverse effects. Three patients (17.7%) eventually had pouch failure after failing to respond to adalimumab therapy.

CONCLUSION

Adalimumab appeared to be well-tolerated and efficacious in treating CD of the pouch in this open-labelled induction study.

Experimental and molecular dynamics investigation on tribological properties of nanocrystalline diamond films

Nanocrystalline diamond films were deposited on cemented tungsten carbide substrates using hot filament chemical vapor deposition (HFCVD) method, and their tribological properties were investigated by friction experiments and classical molecular dynamics simulations. The friction tests were performed on a ball-on-plate type reciprocating friction tester under various normal loads and sliding velocities conditions; the experimental results suggested that the friction coefficient of diamond films showed increasing tendency with the growing normal load and sliding velocity. Furthermore, classical molecular dynamics simulations were conducted to investigate the changes in atomic scale friction behaviors of diamond films under extremely high normal load and sliding velocity conditions, the atomistic sliding mechanism was also discussed in this study.

Intensive glycemic control lowers plasma visfatin levels in patients with type 2 diabetes

Visfatin is an independent association factor for type 2 diabetes mellitus (T2DM). In order to evaluate the plasma visfatin levels and investigate whether plasma visfatin concentrations are altered by intensive glycemic control in patients with diabetes, we determined plasma visfatin concentrations and metabolic parameters in 53 newly diagnosed type 2 diabetic patients and 35 healthy controls. Visfatin levels were also investigated before and after intensive glycemic control for three months in subgroup of patients with T2DM. Plasma visfatin levels were significantly elevated in diabetic patients compared with healthy controls (p<0.001). Circulating visfatin concentration was associated with fasting plasma glucose (FPG), 2-hour OGTT plasma glucose (2hPG), HOMA-beta indexes (r=0.338, p=0.001; r=0.340, p=0.002; r=-0.296, p=0.006, respectively), but not with insulin sensitivity (HOMA-IR) or other metabolic or anthropometric parameters in all subjects. In addition, visfatin levels were also correlated with HbA1c levels in diabetic patients. Furthermore, visfatin concentrations reduced from 25.0+/-6.5 ng/ml at baseline to 20.3+/-4.7 ng/ml (p<0.01) after 3 months of intensive glycemic control, while HbA1c levels decreased from 9.0+/-1.8% to 6.2+/-0.7% (p<0.01). We conclude that the change of visfatin concentration may be a compensatory mechanism to ameliorate insulin deficiency due to pancreatic beta-cell dysfunction.

The pathogenic role of interleukin-27 in autoimmune diabetes

Interleukin (IL)-27 is an IL-12-related cytokine that can promote both anti- and pro-inflammatory immune responses. This study investigated the potential role of IL-27 in autoimmune diabetes. We detected a high level of IL-27 in diabetic NOD mice. In addition, blockade of IL-27 significantly delayed the onset of diabetic splenocyte-transferred diabetes, while IL-27-treated diabetic splenocytes promoted the onset of the disease, compared with untreated controls. Furthermore, IL-27 up-regulated pro-inflammatory cytokines IFN-gamma and IL-17 and down-regulated anti-inflammatory cytokines IL-4, TGF-beta, and IL-10 secreted by diabetic splenocytes. These results demonstrate a pathogenic role of IL-27 in T cell-mediated autoimmune diabetes.

A new strategy to induce effective antitumour response in vitro and in vivo

To induce Her2-specific cell immune response, we used xenogeneic antigen rat neu L2-S2 domains as the vaccine antigen. The antigenic protein was engineered as a chimeric protein with human IgG1 Fc region (neu-Fc). Neu-Fc could stimulate the cell proliferation in mixed lymphocyte reaction effectively. Simultaneous neu-Fc and IFN-gamma stimulation dramatically elevated IL-12 secretion and reduced IL-10 production in PBMC. To further augment the activating effects on Th1-type response, Bacille Calmette-Guerin (BCG) was utilized as a non-specific stimulus. Neu-Fc, IFN-gamma and BCG costimulation exhibited the most conspicuous effects on the reversal of the Th1-type inhibitory effects by MCF-7 cell supernatant compared with neu-Fc alone or IFN-gamma and BCG costimulation. The lytic activity of effector cells to Her2 overexpressing cells was greatly promoted by neu-Fc, IFN-gamma and BCG stimulation simultaneously. Neu-Fc led to considerable retardation in EMT6/Her2 tumour growth in Balb/c mice. IFN-gamma and BCG efficiently enhanced the antitumour activity. A large amount of inflammatory cells were found to be accumulated in the tumour tissues or surrounded tumours in mice treated with neu-Fc, IFN-gamma and BCG but no inflammatory cell infiltration was observed in control tumours, indicating that the strategy is potent enough to support the initiation and propagation of tumour-specific immune response in an established tumour and generate a proinflammatory environment.

Anomalous photogalvanic effect of circularly polarized light incident on the two-dimensional electron gas in Al{x}Ga{1-x}N/GaN heterostructures at room temperature

Under normal incidence of circularly polarized light at room temperature, a charge current with swirly distribution has been observed in the two-dimensional electron gas in Al{0.25}Ga{0.75}N/GaN heterostructures. We believe that this anomalous charge current is produced by a radial spin current via the reciprocal spin Hall effect. It suggests a new way to research the reciprocal spin Hall effect and spin current on the macroscopic scale and at room temperature.

Overexpression, refolding, purification of Erbin PDZ domain from Escherichia coli and preparation of its polyclonal antibody

The Erbin was recently identified. The antibody against Erbin has not been commercially available. As a new member of peripheral protein LAP family and novel type of adaptor protein, its functions and binding partners are not completely known. In the present study, cDNA encoding PDZ domain of Erbin was inserted in a prokaryotic expression vector. His-tagged recombinant protein was overproduced in E. coli and purified by Ni-NTA column chromatography. About 14.4 mg of the purified protein was obtained from 500 mL of cell culture. The purity of the recombinant protein was higher than 90%. The polyclonal antibody against this protein was raised. The antibody can recognize both denatured and natural Erbin protein. It will be used to further identify the new binding partners of Erbin and study its unknown functions.