Astrocytic water channel aquaporin-4 modulates brain plasticity in both mice and humans: a potential gliogenetic mechanism underlying language-associated learning

The role of astrocytes in brain plasticity has not been extensively studied compared with that of neurons. Here we adopted integrative translational and reverse-translational approaches to explore the role of an astrocyte-specific major water channel in the brain, aquaporin-4 (AQP4), in brain plasticity and learning. We initially identified the most prevalent genetic variant of AQP4 (single nucleotide polymorphism of rs162008 with C or T variation, which has a minor allele frequency of 0.21) from a human database (n=60 706) and examined its functionality in modulating the expression level of AQP4 in an in vitro luciferase reporter assay. In the following experiments, AQP4 knock-down in mice not only impaired hippocampal volumetric plasticity after exposure to enriched environment but also caused loss of long-term potentiation after theta-burst stimulation. In humans, there was a cross-sectional association of rs162008 with gray matter (GM) volume variation in cortices, including the vicinity of the Perisylvian heteromodal language area (Sample 1, n=650). GM volume variation in these brain regions was positively associated with the semantic verbal fluency. In a prospective follow-up study (Sample 2, n=45), the effects of an intensive 5-week foreign language (English) learning experience on regional GM volume increase were modulated by this AQP4 variant, which was also associated with verbal learning capacity change. We then delineated in mice mechanisms that included AQP4-dependent transient astrocytic volume changes and astrocytic structural elaboration. We believe our study provides the first integrative evidence for a gliogenetic basis that involves AQP4, underlying language-associated brain plasticity.

Minimum Two-Year Follow-up of Anterior Cruciate Ligament Reconstruction in Patients with Generalized Joint Laxity

BACKGROUND

The purposes of this investigation were to compare outcomes of anterior cruciate ligament (ACL) reconstruction between patients with generalized joint laxity and those without it and to investigate the effect of generalized joint laxity on outcomes of ACL reconstruction from 2 to 8 years postoperatively.

METHODS

We retrospectively reviewed 163 patients who had undergone unilateral ACL reconstruction from January 2001 to December 2008. Patients were divided into 2 groups according to presence or absence of generalized joint laxity. The proportions of patients with meniscectomy, graft rupture, and contralateral ACL rupture were compared. Rupture rates were compared with Kaplan-Meier analysis. The Lachman test, pivot-shift test, and anterior translation measured with the KT-2000 arthrometer were evaluated. The Lysholm knee score and International Knee Documentation Committee (IKDC) subjective score were compared. The IKDC objective grade and radiographic grade were also evaluated. Follow-up assessments were performed at 2, 5, and 8 years postoperatively.

RESULTS

The proportions of meniscectomy, graft rupture, and contralateral ACL rupture in patients with generalized joint laxity were higher than in patients without generalized joint laxity during the whole evaluation period. However, differences in proportions and cumulative rupture rates did not reach significance (p > 0.05). Patients with generalized joint laxity had less stability and poorer functional outcomes at the 8-year follow-up compared with patients without generalized joint laxity. With regard to the Lachman test and anterior translation, poorer results were shown in patients with generalized joint laxity than in patients without generalized joint laxity during the whole evaluation period. The results of pivot-shift testing differed significantly at 5 years (p = 0.002) and 8 years (p = 0.007). Patients with generalized joint laxity also had worse Lysholm knee scores and IKDC subjective scores during the whole evaluation period; these differences may not be clinically important. Comparisons between serial outcomes measured at 2, 5, and 8-year follow-ups within each patient group showed that anterior translation (p = 0.002), Lysholm knee score (p = 0.014), and IKDC subjective score (p = 0.002) deteriorated over time, although the values at 8 years were similar to those at 5 years, in patients with generalized joint laxity.

CONCLUSIONS

Generalized joint laxity as an inherent physiologic characteristic of patients was related to a significant adverse effect on stability and functional outcomes of ACL reconstruction for patients followed for 2 to 8 years. Generalized joint laxity should be considered a risk factor for poor outcomes after ACL reconstruction.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Butyrate and retinoic acid imprint mucosal-like dendritic cell development synergistically from bone marrow cells

Accumulating data show that the phenotypes and functions of distinctive mucosal dendritic cells (DCs) in the gut are regulated by retinoic acid (RA). Unfortunately, the exact role of butyrate in RA-mediated mucosal DC differentiation has not been elucidated thoroughly to date. Mucosal-like dendritic cell differentiation was completed in vitro by culturing bone marrow cells with growth factors [granulocyte-macrophage colony-stimulating factor (GM-CSF/interleukin (IL)-4], RA and/or butyrate. The phenotypes, cytokine secretion, immune functions and levels of retinal dehydrogenase of different DCs were detected using quantitative polymerase chain reaction (qPCR), enzyme-linked immunosorbent assay (ELISA) and flow cytometry, respectively. The results showed that RA-induced DCs (RA-DCs) showed mucosal DC properties, including expression of CD103 and gut homing receptor α₄ β₇ , low proinflammatory cytokine secretion and low priming capability to antigen-specific CD4⁺ T cells. Butyrate-treated RA-DCs (Bu-RA-DCs) decreased CD11c, but increased CD103 and α₄ β₇ expression. Moreover, the CD4⁺ T priming capability and the levels of retinal dehydrogenase of RA-DCs were suppressed significantly by butyrate. Thus, butyrate and retinoic acid have different but synergistic regulatory functions on mucosal DC differentiation, indicating that immune homeostasis in the gut depends largely upon RA and butyrate to imprint different mucosal DC subsets, both individually and collectively.

Removal of a broken trigen intertan intertrochanteric antegrade nail

Implant breakage is a serious complication after cephalomedullary nailing for unstable intertrochanteric fracture. Failure usually occurs at the lag screw hole in the nail body. On the other hand, lag screw failure is extremely rare and occurs around the nail-lag screw junction. We experienced rare mechanical failure of the Intertan nail, which showed breakage at the lag screw hole and failure of the integrated compression screw underneath the main lag screw.

Partial protease activity characterization of squid (Todaropsis eblanae) mantle / Caracterización parcial de la actividad proteolítica del manto de pota (Todaropsis eblanae)

Proteolytic activity in mantle of Todaropsis eblanae was maximum at 40 and 65 °C. Several peaks of activity were detected over the pH range studied (1.5-9.5), indicating the presence of acidic, neutral and alkaline proteases, depending on the temperature. The substantial enzymic inhibition at acidic pH by the inhibitor trans-epoxysuccinyl-L-leucylamine-4-guanidine butane (E-64) revealed the pre dominance of lysosomal cysteine proteases (cathepsins) which showed higher activity at 65 °C than at 40 °C. At 65 °C and pH 5.5 metallo-proteases were also detected by the inhibition with phenanthroline. Serine protease activity predominated at neutral pH (higher at 40 °C than at 65 °C), and cysteine proteases were detected at alkaline pH. There was evidence of cathepsin B and L activity at 65 °C and to a lesser degree at 40 °C.

Novel statistical methodology reveals that hip shape is associated with incident radiographic hip osteoarthritis among African American women

INTRODUCTION

Hip shape is a risk factor for the development of hip osteoarthritis (OA), and current methods to assess hip shape from radiographs are limited; therefore this study explored current and novel methods to assess hip shape.

METHODS

Data from a prior case-control study nested in the Johnston County OA Project were used, including 382 hips (from 342 individuals). Hips were classified by radiographic hip OA (RHOA) status as RHOA cases (baseline Kellgren Lawrence grade [KLG] 0 or 1, follow-up [mean 6 years] KLG ≥ 2) or controls (KLG = 0 or 1 at both baseline and follow-up). Proximal femur shape was assessed using a 60-point model as previously described. The current analysis explored commonly used principal component analysis (PCA), as well as novel statistical methodologies suited to high dimension low sample size settings (Distance Weighted Discrimination [DWD] and Distance Projection Permutation [DiProPerm] hypothesis testing) to assess differences between cases and controls.

RESULTS

Using these novel methodologies, we were able to better characterize morphologic differences by sex and race. In particular, the proximal femurs of African American women demonstrated significantly different shapes between cases and controls, implying an important role for sex and race in the development of RHOA. Notably, discrimination was improved with the use of DWD and DiProPerm compared to PCA.

CONCLUSIONS

DWD with DiProPerm significance testing provides improved discrimination of variation in hip morphology between groups, and enables subgroup analyses even under small sample sizes.

Systemic inflammation score predicts postoperative prognosis of patients with clear-cell renal cell carcinoma

BACKGROUND

Growing evidence indicates that inflammation has a crucial role in the development and progression of cancer. We developed a novel systemic inflammation score (SIS) based on preoperative serum albumin and lymphocyte-to-monocyte ratio (LMR), and examined its prognostic value for patients with clear-cell renal cell carcinoma (ccRCC) after surgery.

METHODS

The study comprised 441 ccRCC patients undergoing nephrectomy between 2008 and 2009 in a single centre. The SIS was developed and its associations with clinicopathological features and overall survival (OS) were evaluated.

RESULTS

The SIS consisted of serum albumin and LMR that were both retained as independent indicators adjusting for other haematological and laboratory markers of systemic inflammation responses and traditional clinicopathological features. A high SIS was significantly associated with aggressive tumour behaviours and served as an independent prognostic factor of reduced OS. Furthermore, the SIS could significantly stratify patient prognosis in different tumour stages and Mayo Clinic stage, size, grade and necrosis scores. Incorporation of the SIS into a prognostic model including TNM stage, Fuhrman grade and lymphovascular invasion generated a nomogram, which predicted accurately 3- and 5-year survival for ccRCC patients.

CONCLUSIONS

The SIS as a potentially powerful prognostic biomarker might improve traditional clinicopathological analysis to refine clinical outcome prediction for ccRCC patients after surgery.

Asymmetries in core-collapse supernovae from maps of radioactive 44Ti in Cassiopeia A

Asymmetry is required by most numerical simulations of stellar core-collapse explosions, but the form it takes differs significantly among models. The spatial distribution of radioactive (44)Ti, synthesized in an exploding star near the boundary between material falling back onto the collapsing core and that ejected into the surrounding medium, directly probes the explosion asymmetries. Cassiopeia A is a young, nearby, core-collapse remnant from which (44)Ti emission has previously been detected but not imaged. Asymmetries in the explosion have been indirectly inferred from a high ratio of observed (44)Ti emission to estimated (56)Ni emission, from optical light echoes, and from jet-like features seen in the X-ray and optical ejecta. Here we report spatial maps and spectral properties of the (44)Ti in Cassiopeia A. This may explain the unexpected lack of correlation between the (44)Ti and iron X-ray emission, the latter being visible only in shock-heated material. The observed spatial distribution rules out symmetric explosions even with a high level of convective mixing, as well as highly asymmetric bipolar explosions resulting from a fast-rotating progenitor. Instead, these observations provide strong evidence for the development of low-mode convective instabilities in core-collapse supernovae.

PPM1A is a RelA phosphatase with tumor suppressor-like activity

Nuclear factor-κB (NF-κB) signaling contributes to human disease processes, notably inflammatory diseases and cancer. NF-κB has a role in tumorigenesis and tumor growth, as well as promotion of metastases. Mechanisms responsible for abnormal NF-κB activation are not fully elucidated; however, RelA phosphorylation, particularly at serine residues S536 and S276, is critical for RelA function. Kinases that phosphorylate RelA promote oncogenic behaviors, suggesting that phosphatases targeting RelA could have tumor-inhibiting activities; however, few RelA phosphatases have been identified. Here, we identified tumor inhibitory and RelA phosphatase activities of the protein phosphatase 2C (PP2C) phosphatase family member, PPM1A. We show that PPM1A directly dephosphorylated RelA at residues S536 and S276 and selectively inhibited NF-κB transcriptional activity, resulting in decreased expression of monocyte chemotactic protein-1/chemokine (C-C motif) ligand 2 and interleukin-6, cytokines implicated in cancer metastasis. PPM1A depletion enhanced NF-κB-dependent cell invasion, whereas PPM1A expression inhibited invasion. Analyses of human expression data revealed that metastatic prostate cancer deposits had lower PPM1A expression compared with primary tumors without distant metastases. A hematogenous metastasis mouse model revealed that PPM1A expression inhibited bony metastases of prostate cancer cells after vascular injection. In summary, our findings suggest that PPM1A is a RelA phosphatase that regulates NF-κB activity and that PPM1A has tumor suppressor-like activity. Our analyses also suggest that PPM1A inhibits prostate cancer metastases and as neither gene deletions nor inactivating mutations of PPM1A have been described, increasing PPM1A activity in tumors represents a potential therapeutic strategy to inhibit NF-κB signaling or bony metastases in human cancer.

Platelet glycoprotein IaC807T polymorphisms and ischemic stroke in young Chinese Han population

OBJECTIVES

The objective of this study was to investigate the association between platelet glycoprotein (GP) Ia C807T polymorphisms and ischemic stroke in young Chinese Han Population.

MATERIALS AND METHODS

We conducted a case-control study in 92 consecutive young (</= 50 years) first-ever hospitalized ischemic stroke inpatients and outpatients, 86 elder ischemic stroke control (> 50 years), and 160 age- and sex-matched healthy control. Genotyping of platelet GP Ia C807Tpolymorphisms was performed by polymerase chain reaction followed by sequencing nucleic acid with dideoxy chain-termination method and an ABI PRISM3100 (Perkin-Elmer Co) genetic analyzer. Student's t-test, chi-square test, and logistic regression modeling were used for data significance analyses.

RESULTS

Hypertension and smoking were found to be the independent risk factors for ischemic stroke patients (aged </= 50 years), while hypertension, diabetes and smoking were the independent risk factors for ischemic stroke patients (aged > 50 years). There was no significant difference observed in the T allele frequency of GPIa C807T polymorphisms between young stroke patients and corresponding controls.

CONCLUSIONS

These findings suggest that there is no role of GPIa C807T polymorphisms in the development of young first-ever ischemic stroke in Chinese Han Population.

Factors leading to under-reporting of tuberculosis in the private sector in Korea

OBJECTIVE

To identify factors associated with under-reporting of tuberculosis (TB) in the private sector in Korea.

DESIGN

A cross-sectional study of 37,820 cases in whom treatment was initiated between January and December 2008 using data from the Nationwide Medical Records Survey of Patients with TB. Adjusted odds ratios (aOR) for under-reporting with respect to socio-demographic and clinical factors were estimated.

RESULTS

Among the 37,820 identified cases, 21,611 (57.1%) were reported to the Korean TB Surveillance System. Factors associated with under-reporting on univariate analysis included young children, foreign-born persons, non-multidrug-resistant TB, persons prescribed fewer than four anti-tuberculosis drugs, non-performance of or negative result on sputum smear and extra-pulmonary TB (particularly abdominal or genitourinary TB). For pulmonary TB, cases with no sputum smear results vs. smear-positive patients (aOR 2.23, P < 0.001) and those prescribed <4 drugs vs. those who were prescribed ≥4 drugs (aOR 1.60, P < 0.001) were strongly related to under-reporting on multivariate analysis.

CONCLUSION

The extent of under-reporting was greater among young children, persons who had not received sputum smear testing and those who had been prescribed fewer than four drugs. Furthermore, TB diagnostic investigations were often inadequate. Education on reporting requirements, including the importance of following guidelines on TB management, and a stricter enforcement of the existing TB Prevention Law, are needed.

Haloperidol and clozapine block formation of autophagolysosomes in rat primary neurons

Early intervention and maintenance treatment for schizophrenia patients may prolong the duration of exposure to antipsychotic agents; however, there have been few studies on the neurotoxicity of these agents. Here, we investigated the effects of antipsychotics on cell viability and autophagy in rat primary neurons. Cultured cortical neurons obtained from rat embryos were treated with various concentrations of haloperidol and clozapine, and the neuronal toxicity was assessed by measuring lactate dehydrogenase (LDH) activity and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. Autophagosomes were quantitated by measuring the level of microtubule-associated protein 1A/1B-light chain 3 (LC3-II) by Western blot and immunofluorescence staining. Autophagic flux was assayed using bafilomycin A1 and GFP-mCherry-LC3 transfection. Haloperidol and clozapine decreased the viability of neurons in vitro in a concentration- and time-dependent manner. We also observed increased accumulation of autophagosomes after antipsychotic treatment. Using bafilomycin A1 and GFP-mCherry-LC3 transfection, we discovered that haloperidol and clozapine inhibited autophagosome turnover resulting in a dysfunctional autophagic process, including impaired lysosomal fusion. Together, these results suggest that haloperidol and clozapine negatively affect neuronal viability, possibly by blocking autophagolysosome formation.

The effect of the respiratory cycle on liver stiffness values as measured by transient elastography

The findings of several studies suggest that liver stiffness values can be affected by the degree of intrahepatic congestion respiration influence intrahepatic blood volume and may affect liver stiffness. We evaluated the influence of respiration on liver stiffness. Transient elastography (TE) was performed at the end of inspiration and at the end of expiration in patients with chronic liver disease. The median values obtained during the inspiration set and during the expiration set were defined as inspiratory and expiratory liver stiffness, respectively. A total of 123 patients with chronic liver disease were enrolled (mean age 49years; 64.2% men). Liver cirrhosis coexisted in 29 patients (23.6%). Expiratory liver stiffness was significantly higher than inspiratory liver stiffness (8.7 vs 7.9kPa, P=0.001), while the expiratory interquartile range/median ratio (IQR ratio) did not differ from the inspiratory IQR ratio. Expiratory liver stiffness was significantly higher than inspiratory liver stiffness in 49 (39.8%) patients (HE group), expiratory liver stiffness was significantly lower than inspiratory stiffness in 15 (12.2%) patients, and there was no difference in 59 (48.0%) patients. Liver cirrhosis was more frequent in those who had a lower liver stiffness reading in expiration, and only the absence of liver cirrhosis was significantly associated with a higher reading in expiration in multivariate analysis. In conclusion, liver stiffness was significantly elevated during expiration especially in patients without liver cirrhosis. The effect of respiration should be kept in mind during TE readings.

Expression of activating and inhibitory leukocyte immunoglobulin-like receptors in rheumatoid synovium: correlations to disease activity

Rheumatoid arthritis (RA) is a heterogeneous chronic inflammatory joint disease characterized by excessive activation of inflammatory cells of which the underlying mechanisms are not fully elucidated. Perturbed expression and function of immune regulatory molecules called leukocyte immunoglobulin-like receptors (LILRs) may contribute to uncontrolled inflammation. LILRs primarily expressed on the surface of leukocytes are emerging as critical regulators of the threshold and amplitude of leukocyte activation. Inhibitory LILRs (LILRBs) contain cytoplasmic tails with immunoreceptor tyrosine-based inhibitory motifs that provide negative signals. Activating LILRs (LILRAs) have short cytoplasmic domains lacking signaling motifs but transmit activating signals by linking to immunoreceptor tyrosine-based activation motifs of the FcR γ-chain. Here we show that activating LILRA2, A5 and inhibitory LILRB2, B3 were abundantly expressed in synovial tissue of > 75% RA patients. Expression of LILRA2, A5, and B3 significantly correlated to disease activity. In contrast, LILRA1 and B4 were expressed in a subset of patients and no B1 or B5 expression was detected. LILRA2 and A5 were mainly expressed by synovial macrophages and endothelial cells but not lymphocytes, whereas B2 and B3 were expressed by macrophages and lymphocytes. Increase in the number of macrophages expressing activating LILRs and macrophages and lymphocytes expressing inhibitory LILRs suggest a crosstalk between these cells that may regulate the levels of cellular activation and disease severity, while differences in expression pattern may contribute to disease heterogeneity.