Chemodiversity of dissolved organic matter exports from subtropical humid catchment driven by hydrological connectivity.

The quantity and quality of dissolved organic matter (DOM) exported from source areas are closely related to hydrological linkage between source areas and streams, that is hydrological connectivity. However, understanding of how hydrological connectivity regulates the export of catchment DOM components remains inadequate. In this study, high-frequency monitoring of groundwater and runoff from subtropical humid catchment was conducted for 20 months, and hydrological connectivity was quantitatively characterized by considering both surface and subsurface hydrological processes. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was utilized to investigate the DOM molecular composition. Results showed that over half of the areas in the catchment could not persistently establish hydrological connectivity with the stream during the rainfall. The average proportion of lignin was the highest in DOM components, followed by tannin and proteins. Additionally, both modified aromaticity index and double bond equivalence reached maximums at peak discharge, reflecting terrestrial materials could increase DOM aromaticity and unsaturated degree. Partial least square-structural equation modeling revealed significantly direct effects of rainfall, antecedent conditions, and hydrological connectivity on dissolved organic carbon (DOC) export. Furthermore, nonlinear relationships were observed between hydrological connectivity and DOC, tannin, and condensed aromatics. Specifically, the instantaneous DOC flux increased dramatically when the hydrological connectivity strength exceeded 0.14; tannin and condensed aromatics exhibited a rapid increase with rising connectivity strength, but remained stable at connectivity strength above 0.25. However, hydrological connectivity showed no significant correlation with unstable components (such as lipids, protein, amino sugars, and carbohydrates). These results provide new insights into hydrological controls on the quantity and quality of DOM export and contribute to developing appropriate catchment management strategies for carbon storage.

Serum immunoinflammation-related protein complexes discriminate between inflammatory bowel disease and colorectal cancer.

PURPOSE: Inflammatory bowel disease (IBD) is an important risk factor for colon cancer. Novel serum immunoinflammation-related protein complexes (IIRPCs) have shown associations with early cancer detection. Herein, we investigated the potential of serum IIRPCs for discriminating between IBD and colorectal cancer (CRC) patients. METHODS: Serum protein complexes of 65 healthy controls, 57 CRC, 69 (ulcerative colitis) UC, and 67 (Crohn's disease) CD patients were isolated by native-PAGE. The gray values of serum IIRPCs bands in the gel were quantified using Quantity One software. The receiver-operating characteristic (ROC) curves were constructed to assess the discriminating ability by calculating the area under the ROC curve. RESULTS: The serum IIRPCs levels in IBD and CRC patients were significantly elevated compared to healthy controls. ROC analysis indicated certain diagnostic ability of serum IIRPCs in differentiating IBD from CRC. Specifically, "a3" complex discriminated UC from CRC, with an AUC value of 0.722, sensitivity of 69.4% and specificity of 63.8%. Similarly, "b4" complex discriminated UC from CRC, with an AUC value of 0.709, sensitivity of 70.4%, and specificity of 60.0%. In addition, the "a3" complex also discriminated CD from CRC, with an AUC value of 0.785, sensitivity of 73.1%, and specificity of 74.1%, while the "b4" complex showed a tendency to discriminate CD from CRC, with an AUC value of 0.663, sensitivity of 67.9% and specificity of 50.0%. Thus, an equation based on multiple IIRPCs was built to further improve the discriminating power. CONCLUSIONS: Serum IIRPCs can be used to discriminate IBD from CRC and may also be associated with early screening of colitis-associated cancer.

[The efficacy of cyclosporine A as salvage therapy for severe active ulcerative colitis refractory to glucocorticoid].

Objective: To clarify the efficacy and safety of cyclosporine A (CsA) as salvage therapy in patients with severe active ulcerative colitis (UC) and refractory to steroids. Methods: A total of 24 severe active UC patients refractory to steroids and hospitalized from 2006 to 2012, were retrospectively enrolled.Data including demographic features, clinical manifestations, laboratory tests and medications were collected. Results: CsA was effective in 15(62.5%) patients, who did not receive colectomy during 12-week administration. This regimen was tolerable in most patients.Twelve (50.0%) patients reported 16 adverse events, but only one patient withdrew CsA due to intolerance.The rates of adverse events in initial intravenous CsA including 4 mg·kg(-1)·d(-1,) 3 mg·kg(-1)·d(-1) and 2 mg·kg(-1)·d(-1) were 2/2, 9/17 and 1/5 respectively.Responders had higher white blood cell count compared with non-responders (P= 0.045). Conclusions: CsA could be an effective alternative regimen to colectomy in severe active UC patients who are refractory to steroids.

[An analysis of clinical characteristics of twelve cases of mesenteric panniculitis].

Objective: Mesenteric panniculitis is an idiopathic, uncommon disease involving the adipose tissue of mesentery. The etiology, diagnosis and treatment are still unnoticed. We thus reported a case series to improve the understanding of this rare disorder. Methods: We retrospectively analyzed the clinical data of 12 patients with mesenteric panniculitis including manifestation, diagnosis, treatment and prognosis. Results: We found a male predominance (M∶F 3∶1) with the median age of 58 years old at diagnosis. The most common symptom was abdominal pain (9/12), followed by abdominal distension (3/12) and weight loss (3/12). Physical examination was unremarkable in the majority of patients (8/12). C reactive protein (9/12) and erythrocyte sedimentation rate (10/12) were normal in majority of patients. CT findings were of much diagnostic value. All patients had small intestinal mesentery involvement and multi-nodular appearance with increased fat density. Pseudo-capsule sign (8/12) and fat halo sign (6/12) were common. Pathological diagnosis was obtained in 4 cases showing fat tissue inflammation with local necrosis and fibrosis. Six cases all received prednisone, 2 with combined cyclophosphamide, 1 with azathioprine, 1 with tripterygium wilfordii. Short-term clinical response was achieved in all cases, but two patients relapsed. Conclusions: Mesenteric panniculitis occurs predominantly in middle-aged and elderly. Abdominal pain is the leading symptom. Inflammatory markers are often normal while computed tomography is the most important diagnostic tool. Surgery combined with cortical steroid and immunosuppressant agents is effective.

[A retrospective case-control study of immunoglobulin G4-related disease combined with malignancy].

IgG4-related disease (IgG4-RD) has been proved to be associated with malignancy.The incidence and risk factors of malignancy development in IgG4-RD were not clear. Nine IgG4-RD patients with malignancies and 27 IgG4-RD control cases were analyzed for risk factors and clinical features. The incidence of malignancy in IgG4-RD was 3.3%, higher than age-controlled general population. Smoking history was significantly more common in patients with malignancies than in the control group (9/9 vs 16/27, P<0.05). A total of 6/9 malignancies occurred within the first year after the diagnosis of IgG4-RD. Colorectal, biliary and thyroid cancers were the leading types. Smoking history is a risk factor for IgG4-RD associated malignancy. Careful vigilance to monitor malignancy needs to be paid during follow-up.

Structurally diverse amphiphiles exhibit biphasic modulation of GABAA receptors: similarities and differences with neurosteroid actions.

BACKGROUND AND PURPOSE: Some neurosteroids, notably 3alpha-hydroxysteroids, positively modulate GABA(A) receptors, but sulphated steroids negatively modulate these receptors. Recently, other lipophilic amphiphiles have been suggested to positively modulate GABA receptors. We examined whether there was similarity among the actions of these agents and the mechanisms of neurosteroids. Significant similarity would affect theories about the specificity of steroid actions. EXPERIMENTAL APPROACH: Xenopus laevis oocytes were challenged with Triton X-100, octyl-beta-glucoside, capsaicin, docosahexaenoic acid and sodium dodecyl sulphate (SDS), along with different GABA concentrations. KEY RESULTS: These compounds have both positive and negative effects on GABA currents, which can be accentuated according to the degree of receptor activation. A low GABA concentration (1 microM) promoted potentiation and a high concentration (20 microM) promoted inhibition of current, except for SDS that inhibited function even at low GABA concentrations. Amphiphile inhibition was characterized by enhanced apparent desensitization and by weak voltage dependence, similar to pregnenolone sulphate antagonism. We then tested amphiphile effects on mutated receptor subunits that are insensitive to negative (alpha1V256S) and positive (alpha1Q241L or alpha1N407A/Y410F) steroid modulation. Negative regulation by amphiphiles was nearly abolished in alpha1V256S-mutated receptors, but potentiation was unaffected. In alpha1Q241L- or alpha1N407A/Y410F-mutated receptors, potentiation by amphiphiles remained intact. CONCLUSIONS AND IMPLICATIONS: Structurally diverse amphiphiles have antagonist actions at GABA(A) receptors very similar to those of sulphated neurosteroids, while the potentiating mechanisms of these amphiphiles are distinct from those of neurosteroid-positive modulators. Thus, such antagonism at GABA(A) receptors does not have a clear pharmacophore requirement.

Cyclodextrins sequester neuroactive steroids and differentiate mechanisms that rate limit steroid actions.

BACKGROUND AND PURPOSE: Neuroactive steroids are potent modulators of GABA(A) receptors and are thus of interest for their sedative, anxiolytic, anticonvulsant and anaesthetic properties. Cyclodextrins may be useful tools to manipulate neuroactive effects of steroids on GABA(A) receptors because cyclodextrins form inclusion complexes with at least some steroids that are active at the GABA(A) receptor, such as (3alpha,5alpha)-3-hydroxypregnan-20-one (3alpha5alphaP, allopregnanolone). EXPERIMENTAL APPROACH: To assess the versatility of cyclodextrins as steroid modulators, we investigated interactions between gamma-cyclodextrin and neuroactive steroids of different structural classes. KEY RESULTS: Both a bioassay based on electrophysiological assessment of GABA(A) receptor function and optical measurements of cellular accumulation of a fluorescent steroid analogue suggest that gamma-cyclodextrin sequesters steroids rather than directly influencing GABA(A) receptor function. Neither a 5beta-reduced A/B ring fusion nor a sulphate group at carbon 3 affected the presumed inclusion complex formation between steroid and gamma-cyclodextrin. Apparent dissociation constants for interactions between natural steroids and gamma-cyclodexrin ranged from 10-60 microM. Although gamma-cyclodextrin accommodates a range of natural and synthetic steroids, C(11) substitutions reduced inclusion complex formation. Using gamma-cyclodextrin to remove steroid not directly bound to GABA(A) receptors, we found that cellular retention of receptor-unbound steroid rate limits potentiation by 3alpha- hydroxysteroids but not inhibition by sulphated steroids. CONCLUSIONS AND IMPLICATIONS: We conclude that gamma-cyclodextrins can be useful, albeit non-specific, tools for terminating the actions of multiple classes of naturally occurring neuroactive steroids.

Expression of fructose sensitive glucose transporter in the brains of fructose-fed rats.

Glucose transporters play a critical role in mammalian brain energy metabolism because glucose is the principal brain energy source and these transporters promote glucose movement into neural cells. When glucose is unavailable, fructose can serve as an alternative energy source. Using real-time polymerase chain reaction and actin as a reference mRNA, we investigated the impact of fructose feeding on rat brain and other tissue mRNA expression of glucose transporter 5 which has high affinity for fructose. Brain mRNA levels of glucose transporter 5 increased 1.5-fold in 35-day old rats after 7 days of fructose feeding compared with controls, whereas it increased 2.5-fold in jejunum. Semi-quantitative analysis of protein expression by immunofluorescence of glucose transporter 5 in rat hippocampi indicated a 2.4-fold increase. We demonstrated the specificity of fructose feeding on glucose transporter 5 expression by showing that the expression of the neuronal glucose transporter 3 and insulin-regulated glucose transporter 4 were unaffected. In addition, the expression of glucose transporter 5 increased in fructose fed older adult rats (8-months and 12-months old) when compared with controls. These results suggest that short-term fructose feeding increases the expression of glucose transporter 5 in both young and aging adult rats. Increased brain expression of glucose transporter 5 is likely to be important in the role of fructose as an alternative energy source.

Distinct RNP complexes of shuttling hnRNP proteins with pre-mRNA and mRNA: candidate intermediates in formation and export of mRNA.

Nascent pre-mRNAs associate with hnRNP proteins in hnRNP complexes, the natural substrates for mRNA processing. Several lines of evidence indicate that hnRNP complexes undergo substantial remodeling during mRNA formation and export. Here we report the isolation of three distinct types of pre-mRNP and mRNP complexes from HeLa cells associated with hnRNP A1, a shuttling hnRNP protein. Based on their RNA and protein compositions, these complexes are likely to represent distinct stages in the nucleocytoplasmic shuttling pathway of hnRNP A1 with its bound RNAs. In the cytoplasm, A1 is associated with its nuclear import receptor (transportin), the cytoplasmic poly(A)-binding protein, and mRNA. In the nucleus, A1 is found in two distinct types of complexes that are differently associated with nuclear structures. One class contains pre-mRNA and mRNA and is identical to previously described hnRNP complexes. The other class behaves as freely diffusible nuclear mRNPs (nmRNPs) at late nuclear stages of maturation and possibly associated with nuclear mRNA export. These nmRNPs differ from hnRNPs in that while they contain shuttling hnRNP proteins, the mRNA export factor REF, and mRNA, they do not contain nonshuttling hnRNP proteins or pre-mRNA. Importantly, nmRNPs also contain proteins not found in hnRNP complexes. These include the alternatively spliced isoforms D01 and D02 of the hnRNP D proteins, the E0 isoform of the hnRNP E proteins, and LRP130, a previously reported protein with unknown function that appears to have a novel type of RNA-binding domain. The characteristics of these complexes indicate that they result from RNP remodeling associated with mRNA maturation and delineate specific changes in RNP protein composition during formation and transport of mRNA in vivo.