Mapping homeostatic synaptic plasticity using cable properties of dendrites

When chronically silenced, cortical and hippocampal neurons homeostatically upregulate excitatory synaptic function. However, the subcellular position of such changes on the dendritic tree is not clear. We exploited the cable-filtering properties of dendrites to derive a parameter, the dendritic filtering index (DFI), to map the spatial distribution of synaptic currents. Our analysis indicates that young rat cortical neurons globally scale AMPA receptor-mediated currents, while mature hippocampal neurons do not, revealing distinct homeostatic strategies between brain regions and developmental stages. The DFI presents a useful tool for mapping the dendritic origin of synaptic currents and the location of synaptic plasticity changes.

Tofacitinib withdrawal and retreatment in moderate-to-severe chronic plaque psoriasis: a randomized controlled trial

BACKGROUND

Tofacitinib is an oral Janus kinase inhibitor being investigated for the treatment of moderate-to-severe plaque psoriasis.

OBJECTIVES

To compare outcomes following tofacitinib withdrawal with outcomes of continuation.

METHODS

In this phase 3 study (NCT01186744), patients received tofacitinib 5 mg (n = 331) or 10 mg (n = 335) twice daily for 24 weeks. The patients who achieved both ≥ 75% reduction in Psoriasis Area and Severity Index (PASI 75) score from baseline and Physician's Global Assessment (PGA) of 'clear' or 'almost clear' (PGA response) received a placebo (withdrawal) or the previous dose. At relapse (> 50% reduction in the PASI improvement during initial treatment) or week 40, the patients received the initial dose.

RESULTS

Initial treatment: 33·5% and 55·2% achieved both PASI 75 and PGA responses with tofacitinib 5 and 10 mg twice daily, respectively, making them eligible for the treatment-withdrawal period. Withdrawal: 56·2%, 62·3%, 23·3% and 26·1% maintained PASI 75 responses with tofacitinib 5, 10 mg, placebo (5 mg) and placebo (10 mg) twice daily, respectively; 49·9%, 63·9%, 22·9% and 18·0% maintained PGA responses; and 92·3%, 93·0%, 32·8% and 42·9% did not relapse. Elevations in low-density lipoprotein-cholesterol levels following initial treatment (mean increase: 8·71 mg dL(-1) with 5 mg twice daily, 10·26 mg dL(-1) with 10 mg twice daily) were reversed upon withdrawal. Retreatment: 36·8% and 61·0% of patients who relapsed achieved PASI 75 responses with tofacitinib 5 or 10 mg after 16 weeks; 44·8% and 57·1% regained PGA responses.

CONCLUSIONS

Patients who received continuous treatment maintained a response more effectively when compared with placebo recipients. Safety profiles were comparable in both the continuous treatment group and retreatment group. Of those patients who relapsed, up to 60% recaptured a response with tofacitinib.

Anisotropic thermal conductivity of graphene wrinkles

In this paper, the anisotropic thermal conductivity characteristics of graphene wrinkles are observed for the first time using a non-equilibrium molecular dynamics method. Our results reveal that the wrinkling level has little effect on the thermal conductivity along the wrinkling direction. However, the wrinkling level plays an important role in the reduction of thermal conductivity along the texture direction, which results from the contributions of increased bond length, von Mises stress, broadening of phonon modes and G-band redshift. These results indicate that graphene wrinkles can be a promising candidate to modulate thermal conductivity properties in nanoscale thermal managements and thermoelectric devices.

Comprehensive overexpression analysis of cyclic-di-GMP signalling proteins in the phytopathogen Pectobacterium atrosepticum reveals diverse effects on motility and virulence phenotypes

Bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) is a ubiquitous bacterial signalling molecule produced by diguanylate cyclases of the GGDEF-domain family. Elevated c-di-GMP levels or increased GGDEF protein expression is frequently associated with the onset of sessility and biofilm formation in numerous bacterial species. Conversely, phosphodiesterase-dependent diminution of c-di-GMP levels by EAL- and HD-GYP-domain proteins is often accompanied by increased motility and virulence. In this study, we individually overexpressed 23 predicted GGDEF, EAL or HD-GYP-domain proteins encoded by the phytopathogen Pectobacterium atrosepticum strain SCRI1043. MS-based detection of c-di-GMP and 5'-phosphoguanylyl-(3'-5')-guanosine in these strains revealed that overexpression of most genes promoted modest 1-10-fold changes in cellular levels of c-di-GMP, with the exception of the GGDEF-domain proteins ECA0659 and ECA3374, which induced 1290- and 7660-fold increases, respectively. Overexpression of most EAL domain proteins increased motility, while overexpression of most GGDEF domain proteins reduced motility and increased poly-β-1,6-N-acetyl-glucosamine-dependent flocculation. In contrast to domain-based predictions, overexpression of the EAL protein ECA3549 or the HD-GYP protein ECA3548 increased c-di-GMP concentrations and reduced motility. Most overexpression constructs altered the levels of secreted cellulases, pectinases and proteases, confirming c-di-GMP regulation of virulence in Pe. atrosepticum. However, there was no apparent correlation between virulence-factor induction and the domain class expressed or cellular c-di-GMP levels, suggesting that regulation was in response to specific effectors within the network, rather than total c-di-GMP concentration. Finally, we demonstrated that the cellular localization patterns vary considerably for GGDEF/EAL/HD-GYP proteins, indicating it is a likely factor restricting specific interactions within the c-di-GMP network.

A novel staging model to classify oesophageal squamous cell carcinoma patients in China

BACKGROUND

Oesophageal squamous cell carcinoma (ESCC) is the predominant subtype of oesophageal carcinoma in China, with the overall 5-year survival rate of <10%. The current tumour-node-metastasis (TNM) staging system has become so complex that it is not easy to use in the life expectancy assessment. We aim to combine clinical variables and biomarkers to develop and validate a relative simple and reliable model, named the FENSAM, for ESCC prognosis.

METHODS

To build the FENSAM, we analysed 22 potential prognostic factors from 461 patients, including 9 biomarkers (Ezrin, Fascin, desmocollin 2 (DSC2), pFascin, activating transcription factor 3 (ATF3), connective-tissue growth factor (CTGF), neutrophil gelatinase-associated lipocalin (NGAL), NGAL receptor (NGALR), and cysteine-rich angiogenic protein 61 (CYR61)) and other 13 clinical variables. We selected significant factors associated with survival of ESCC patients, and used them to build our FENSAM model. We then obtained the hazard risk score of the model to classify ESCC patients. In addition, we validated the model in an independent cohort of 290 patients from the same hospital. The predictive performance of the model was assessed by the Area under the Receiver Operating Characteristic Curve (AUC) and Kaplan-Meier survival analysis.

RESULTS

We found six markers significantly associated with survival of ESCC patients (Ezrin, Fascin, ATF3, surgery extent, N-stage, and M-stage). They were combined to create a novel four-stage FENSAM model for patients' classification. FENSAM possessed a high classification precision similar to the TNM staging system, but with a much simpler model. The efficiency of FENSAM was evaluated by different quantiles of AUC and the results of survival analysis. The validation result demonstrated the potential of the FENSAM model to improve classification accuracy for ESCC patients.

CONCLUSIONS

FENSAM provides an alternative classifier for ESCC patients with a high classification precision using a simple model.

Effect of vitamin D therapy in addition to amitriptyline on migraine attacks in pediatric patients

The purpose of this study was to investigate the effect of supplementary vitamin D therapy in addition to amitriptyline on the frequency of migraine attacks in pediatric migraine patients. Fifty-three children 8-16 years of age and diagnosed with migraine following the International Headache Society 2005 definition, which includes childhood criteria, were enrolled. Patients were classified into four groups on the basis of their 25-hydroxyvitamin D [25(OH)D] levels. Group 1 had normal 25(OH)D levels and received amitriptyline therapy alone; group 2 had normal 25(OH)D levels and received vitamin D supplementation (400 IU/day) plus amitriptyline; group 3 had mildly deficient 25(OH)D levels and received amitriptyline plus vitamin D (800 IU/day); and group 4 had severely deficient 25(OH)D levels and was given amitriptyline plus vitamin D (5000 IU/day). All groups were monitored for 6 months, and the number of migraine attacks before and during treatment was determined. Calcium, phosphorus alkaline phosphatase, parathormone, and 25(OH)D levels were also determined before and during treatment. Results were compared between the groups. Data obtained from the groups were analyzed using one-way analysis of variance. The number of pretreatment attacks in groups 1 to 4 was 7±0.12, 6.8±0.2, 7.3±0.4, and 7.2±0.3 for 6 months, respectively (all P>0.05). The number of attacks during treatment was 3±0.25, 1.76±0.37 (P<0.05), 2.14±0.29 (P<0.05), and 1.15±0.15 (P<0.05), respectively. No statistically significant differences in calcium, phosphorus, alkaline phosphatase, or parathormone levels were observed (P>0.05). Vitamin D given in addition to anti-migraine treatment reduced the number of migraine attacks.

Effect of intra-abdominal volume increment on lungs in hemorrhagic shock

PURPOSE

Intra-abdominal hypertension (IAH) causes lung dysfunction in patients after hemorrhagic shock resuscitation. We performed intra-abdominal volume increment (IAVI) to IAH and studied its effect on pulmonary function.

METHODS

Eight minipigs established for IAH model by exsanquination until shock, incomplete blockage of portal vein and overload resuscitation were randomly divided into IAVI group (n=4) and sham-operated control group (n=4). Bladder pressure, arterial blood gas analysis and thoraco-abdominal computed tomography (CT) scans were measured. The minipigs were sacrificed 26 h after surgery, and lung samples were harvested for measuring the wet-to-dry weight ratio and hematoxylin-eosin staining.

RESULTS

Compared with sham-operated control group, the respiratory rate and paCO2 remarkably decreased and paO2 notably increased at 8 and 12 h in the IAVI group. The bladder pressure also notably decreased at 8, 12, and 22 h after IAVI treatment. However, a significant improvement in diaphragm height was observed at 22 h after IAVI treatment. The wet-to-dry weight ratio of the lungs in IAVI group was also significantly higher than that that in the sham-operated control group.

CONCLUSION

Our data indicate that IAVI surgery could improve the damaged pulmonary function caused by IAH after hemorrhagic shock resuscitation (Tab. 1, Fig. 7, Ref. 21).

Chronic treatment with the mood-stabilizing drug lithium up-regulates nuclear factor E2-related factor 2 in rat pheochromocytoma PC12 cells in vitro

The mood-stabilizing drug lithium is the most commonly used treatment for bipolar disorder. Previous studies have shown that chronic treatment with lithium produces a protective effect against oxidative stress. Nuclear factor E2-related factor 2 (Nrf2) is a gene transcription factor that binds to the electrophile response element (EpRE) and triggers expression of various genes with antioxidant properties. Nrf2 contributes significantly to cytoprotection against oxidative stress. The purpose of this study is to determine the role of Nrf2 in the protective effect of lithium against oxidative stress. We found, using immunoblotting analysis, that chronic, but not acute treatment with lithium increased nuclear levels of Nrf2 in rat pheochromocytoma PC12 cells. DNA pull-down assay has shown that Nrf2 can bind to a double-strained oligonucleotide containing an EpRE site from glutathione s-transferase A4. Electrophorectic gel shift analysis further showed that chronic treatment with lithium increased Nrf-2-EpRE binding activity. We also found that knocking down Nrf2 with its short hairpin RNA inhibited lithium-increased expression of Nrf2 and suppressed the protective effect of lithium against hydrogen peroxide (H₂O₂)-reduced cell viability and H₂O₂-increased DNA fragmentation. Because Nrf2 can induce expression of various genes that play important roles in cytoprotection, the current findings suggest that Nrf2 may mediate the neuroprotective effect of lithium against oxidative stress.