Distinct Pathogenic Mechanisms Research Articles

Differential gene expression in human abdominal aortic aneurysm and aortic occlusive disease.

Abdominal aortic aneurysm (AAA) and aortic occlusive disease (AOD) represent common causes of morbidity and mortality in elderly populations which were previously believed to have common aetiologies. The aim of this study was to assess the gene expression in human AAA and AOD. We performed microarrays using aortic specimen obtained from 20 patients with small AAAs (≤ 55mm), 29 patients with large AAAs (> 55mm), 9 AOD patients, and 10 control aortic specimens obtained from organ donors. Some differentially expressed genes were validated by quantitative-PCR (qRT-PCR)/immunohistochemistry. We identified 840 and 1,014 differentially expressed genes in small and large AAAs, respectively. Immune-related pathways including cytokine-cytokine receptor interaction and T-cell-receptor signalling were upregulated in both small and large AAAs. Examples of validated genes included CTLA4 (2.01-fold upregulated in small AAA, P = 0.002), NKTR (2.37-and 2.66-fold upregulated in small and large AAA with P = 0.041 and P = 0.015, respectively), and CD8A (2.57-fold upregulated in large AAA, P = 0.004). 1,765 differentially expressed genes were identified in AOD. Pathways upregulated in AOD included metabolic and oxidative phosphorylation categories. The UCP2 gene was downregulated in AOD (3.73-fold downregulated, validated P = 0.017). In conclusion, the AAA and AOD transcriptomes were very different suggesting that AAA and AOD have distinct pathogenic mechanisms.

Methicillin-Resistant Staphylococcus aureus central nervous system infections – Analysis and outcome

Introduction. Methicillin-Resistant Staphylococcus aureus (MRSA)-associated infections are potentially devastating and fatal. It has two distinct pathogenic mechanisms: postoperative and spontaneous. In the study presented here, we review the epidemiology, clinical features, response to treatment, and outcome of MRSA central nervous system infections at our tertiary referral institute. Material and methods. In this analysis, we reviewed the medical records of all patients who were diagnosed with S. aureus meningitis between January 2010 and December 2012. Clinical information included predisposing factors, past medical history, comorbidities, mode of acquisition of infection, as well as therapeutic management, length of treatment, and clinical outcomes were analyzed. Results. A total of 34 cases of MRSA meningitis were diagnosed during the study period. There were 28 (82.4%) cases of postoperative meningitis and 6 (17.6%) cases of spontaneous meningitis. A majority (24/28) of the patients had one or the other predisposing conditions for the infection. Compared with patients with postoperative meningitis, patients with spontaneous meningitis had a significantly older (31.93 yrs vs 55.8 yrs; p = 0.021) and higher frequency of community-acquired infection (100% vs. 39%; p = 0.007). In patients with postoperative meningitis, the median postoperative day when the infection manifested clinically was day- 19 (range, 3–90 days). A total of 25/34 (74%) patients received definitive antibiotic (vancomycin and/or linezolid based) therapy. Nine patients were continued on empirical antimicrobial therapy (combination of ceftriaxone, amikacin, and metronidazole), as the organism was sensitive to those drugs. There were no in-hospital mortalities in our series, though 3/34 patients (8.8%) were discharged with Glasgow coma score (GCS)< 8 and 8/34 patients (23.5%) were discharged with GCS 9–12 from the hospital. Conclusion. In acute bacterial meningitis, there is a progressive shift from methicillin-sensitive strains to methicillin-resistant strains in recent years. Although most patients have a favorable response to vancomycin and linezolid, the beneficial effect of combined antimicrobial therapy or alternative antibiotics needs to be evaluated.

Chorea due to diabetic hyperglycemia and uremia: distinct clinical and imaging features.

This study was undertaken to describe the clinical and imaging characteristics of patients with chorea associated with nonketotic hyperglycemia (C-NKH) in comparison with patients with chorea associated with uremia (C-URE). We retrospectively analyzed the clinical data of consecutive 10 C-NKH and five C-URE patients who were treated between January 1, 2001 and January 31, 2013. Women were more frequently affected by C-NKH (70% vs. 30%) and C-URE (80% vs. 20%) compared with men. The C-NKH patients demonstrated T1-hyperintense and inhomogeneous lesions in the basal ganglia, whereas C-URE patients demonstrated T2-hyperintense and homogeneous lesions in the basal ganglia. The mean time for chorea resolution after treatment was significantly shorter in C-NKH patients than in C-URE patients (4.4 ± 2.6 d vs. 73.8 ± 14.2 d, respectively; P = 0.005). The clinical and imaging features are remarkably different between C-NKH and C-URE patients, suggesting distinct pathogenic mechanisms.

Distinct chronology of neuronal cell cycle re-entry and tau pathology in the 3xTg-AD mouse model and Alzheimer's disease patients.

Cell cycle re-entry in Alzheimer's disease (AD) has emerged as an important pathological mechanism in the progression of the disease. This appearance of cell cycle related proteins has been linked to tau pathology in AD, but the causal and temporal relationship between the two is not completely clear. In this study, we found that hyperphosphorylated retinoblastoma protein (ppRb), a key regulator for G1/S transition, is correlated with a late marker for hyperphosphorylation of tau but not with other early markers for tau alteration in the 3xTg-AD mouse model. However, in AD brains, ppRb can colocalize with both early and later markers for tau alterations, and can often be found singly in many degenerating neurons, indicating the distinct development of pathology between the 3xTg-AD mouse model and human AD patients. The conclusions of this study are two-fold. First, our findings clearly demonstrate the pathological link between the aberrant cell cycle re-entry and tau pathology. Second, the chronological pattern of cell cycle re-entry with tau pathology in the 3xTg-AD mouse is different compared to AD patients suggesting the distinct pathogenic mechanism between the animal AD model and human AD patients.

Indications for distinct pathogenic mechanisms of asbestos and silica through gene expression profiling of the response of lung epithelial cells.

Occupational and environmental exposures to airborne asbestos and silica are associated with the development of lung fibrosis in the forms of asbestosis and silicosis, respectively. However, both diseases display distinct pathologic presentations, likely associated with differences in gene expression induced by different mineral structures, composition and bio-persistent properties. We hypothesized that effects of mineral exposure in the airway epithelium may dictate deviating molecular events that may explain the different pathologies of asbestosis versus silicosis. Using robust gene expression-profiling in conjunction with in-depth pathway analysis, we assessed early (24 h) alterations in gene expression associated with crocidolite asbestos or cristobalite silica exposures in primary human bronchial epithelial cells (NHBEs). Observations were confirmed in an immortalized line (BEAS-2B) by QRT-PCR and protein assays. Utilization of overall gene expression, unsupervised hierarchical cluster analysis and integrated pathway analysis revealed gene alterations that were common to both minerals or unique to either mineral. Our findings reveal that both minerals had potent effects on genes governing cell adhesion/migration, inflammation, and cellular stress, key features of fibrosis. Asbestos exposure was most specifically associated with aberrant cell proliferation and carcinogenesis, whereas silica exposure was highly associated with additional inflammatory responses, as well as pattern recognition, and fibrogenesis. These findings illustrate the use of gene-profiling as a means to determine early molecular events that may dictate pathological processes induced by exogenous cellular insults. In addition, it is a useful approach for predicting the pathogenicity of potentially harmful materials.

Cognitive correlates of hallucinations and delusions in Parkinson's disease

BackgroundHallucinations and delusions that complicate Parkinson's disease (PD) could lead to nursing home placement and are linked to increased mortality. Cognitive impairments are typically associated with the presence of hallucinations but there are no data regarding whether such a relationship exists with delusions. ObjectiveWe hypothesized that hallucinations would be associated with executive and visuospatial disturbance. An exploratory examination of cognitive correlates of delusions was also completed to address the question of whether they differ from hallucinations. Methods144 PD subjects completed a neuropsychological battery to assess cognition and the SAPS to examine psychosis. Correlational analyses assessed associations between hallucinations and delusions with cognitive domains. Results48 subjects (33%) reported psychotic symptoms: 25 (17%) experienced hallucinations without delusions, 23 (16%) had symptoms dominated by delusions. Severity and/or number of hallucination subtypes were significantly correlated with lower scores in language, memory, attention, executive functioning, and visuospatial ability. Correlations with delusions were non-significant. Tests of differences in the size of the correlations between groups revealed a significant relationship between language and visuospatial performance with hallucinations. ConclusionsCognitive correlates of hallucinations and delusions appear to be different in PD, suggesting distinct pathogenic mechanisms and possibly anatomical substrates. Hence, delusions may not share the same associations with dementia as hallucinations. Since this is a new finding, further studies will be needed to confirm our results.

Transcription-Associated R-Loop Formation across the Human FMR1 CGG-Repeat Region

Expansion of a trinucleotide (CGG) repeat element within the 5′ untranslated region (5′UTR) of the human FMR1 gene is responsible for a number of heritable disorders operating through distinct pathogenic mechanisms: gene silencing for fragile X syndrome (>200 CGG) and RNA toxic gain-of-function for FXTAS (∼55–200 CGG). Existing models have focused almost exclusively on post-transcriptional mechanisms, but co-transcriptional processes could also contribute to the molecular dysfunction of FMR1. We have observed that transcription through the GC-rich FMR1 5′UTR region favors R-loop formation, with the nascent (G-rich) RNA forming a stable RNA:DNA hybrid with the template DNA strand, thereby displacing the non-template DNA strand. Using DNA:RNA (hybrid) immunoprecipitation (DRIP) of genomic DNA from cultured human dermal fibroblasts with both normal (∼30 CGG repeats) and premutation (55<CGG<200 repeats) alleles, we provide evidence for FMR1 R-loop formation in human genomic DNA. Using a doxycycline (DOX)-inducible episomal system in which both the CGG-repeat and transcription frequency can be varied, we further show that R-loop formation increases with higher expression levels. Finally, non-denaturing bisulfite mapping of the displaced single-stranded DNA confirmed R-loop formation at the endogenous FMR1 locus and further indicated that R-loops formed over CGG repeats may be prone to structural complexities, including hairpin formation, not commonly associated with other R-loops. These observations introduce a new molecular feature of the FMR1 gene that is directly affected by CGG-repeat expansion and is likely to be involved in the associated cellular dysfunction.

Comparative proteome analysis of tracheal tissues in response to infectious bronchitis coronavirus, Newcastle disease virus, and avian influenza virus H9 subtype virus infection

Infectious bronchitis coronavirus (IBV), Newcastle disease virus (NDV), and avian influenza virus (AIV) H9 subtype are major pathogens of chickens causing serious respiratory tract disease and heavy economic losses. To better understand the replication features of these viruses in their target organs and molecular pathogenesis of these different viruses, comparative proteomic analysis was performed to investigate the proteome changes of primary target organ during IBV, NDV, and AIV H9 infections, using 2D‐DIGE followed MALDI‐TOF/TOF‐MS. In total, 44, 39, 41, 48, and 38 proteins were identified in the tracheal tissues of the chickens inoculated with IBV (ck/CH/LDL/97I, H120), NDV (La Sota), and AIV H9, and between ck/CH/LDL/97I and H120, respectively. Bioinformatics analysis showed that IBV, NDV, and AIV H9 induced similar core host responses involved in biosynthetic, catabolic, metabolic, signal transduction, transport, cytoskeleton organization, macromolecular complex assembly, cell death, response to stress, and immune system process. Comparative analysis of host response induced by different viruses indicated differences in protein expression changes induced by IBV, NDV, and AIV H9 may be responsible for the specific pathogenesis of these different viruses. Our result reveals specific host response to IBV, NDV, and AIVH9 infections and provides insights into the distinct pathogenic mechanisms of these avian respiratory viruses.

Abstract P6-12-16: Treatment with indol-3-carbinol (I3C) in a mice xenograft model of canine breast carcinoma alter hormone metabolism and produce liver metastases

Abstract Indol-3-carbinol (I3C) is a chemical component found mainly in the cruciferous family lants (i.e. broccoli, cabbage, cauliflower, etc.). I3C is considered a potential anticancer agent that is naturally present in the diet and could prevents the development of certain tumors, activating tumor suppressor genes, genes involved in apoptosis and detoxifying genes. It has been observed in vitro that suppresses cell proliferation and induces apoptosis in some breast cancers. I3C is also estrogen receptor (ER) and androgen receptor (AR)Antagonist. Therefore, studies using I3C in breast cancer animal models for its action as a preventive or therapeutic substance have started. There are no data on the influence of I3C in human and/or spontaneous or experimental canine inflammatory breast cancers, that has shown to have distinct pathogenic mechanisms. The aim of this study was to analyze the effect of I3C administration at a comparable dose used as preventive in humans in a xenograft model of canine inflammatory carcinoma established in SCID mice. Eighteen mice were used as controls and 13 mice were treated with I3C dose 150 mg/kg/day. Tumor cell proliferation was decreased in the I3C-treated xenografts (lower Ki-67 index, p &amp;lt;0.001), but neoplasms were more frequently ulcerated (p = 0.028), and mice had a higher number of emboli in dermis (p = 0.012) (characteristic of inflammatory breast carcinoma) and liver metastases (p = 0.05). In the treated group the presence of a subpopulation of neoplastic lipid-rich cells was characteristic (p = 0.001) togetehr with a higher content of intratumor androgens (p = 0.02) and serum steroid hormone (p &amp;lt;0 05). These results indicate that treatment with I3C, as administered, is not suitable for inflammatory breast carcinoma. This study was funded by the research project of the Ministry of Science and Innovation SAF2009-10572. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-12-16.

The antimicrobial protein short palate, lung, and nasal epithelium clone 1 (SPLUNC1) is differentially modulated in eosinophilic and noneosinophilic chronic rhinosinusitis with nasal polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a highly heterogeneous disease with aberrant host defense responses. However, whether innate immunity is similarly impaired in patients with eosinophilic and those with noneosinophilic CRSwNP remains unclear. We sought to evaluate the expression and possible modulation of short palate, lung, and nasal epithelium clone 1 (SPLUNC1), an innate immune molecule, in the 2 CRSwNP subsets. Polyp tissue and uncinate processes were collected from 40 patients with CRSwNP, 27 patients with chronic rhinosinusitis without nasal polyps (CRSsNP), and 22 control subjects. Expression of SPLUNC1; Toll-like receptor (TLR) 2, TLR3, and TLR4; and the proinflammatory cytokines IL-1α, IL-4, IL-13, IL-17A, and IFN-γ was examined in nasal tissues. Additionally, SPLUNC1 expression in response to specific inflammatory stimulation was measured in cultured polyp epithelial cells and A549 cells. Polyp tissues exhibited significantly decreased expression of SPLUNC1 and other innate immune molecules compared with uncinate process tissues from patients with CRSwNP (P < .05), patients with CRSsNP, and healthy control subjects. Moreover, the eosinophilic CRSwNP subset exhibited significantly decreased SPLUNC1 expression and numbers of submucosal glands, as well as significantly increased IL-4 and IL-13 mRNA levels, compared with the noneosinophilic subset (P < .05). Accordingly, SPLUNC1 expression in polyp epithelial cells was significantly inhibited by IL-4 and IL-13 stimulation in vitro but was significantly upregulated after stimulation with TLR agonists and glucocorticoids (P < .05). Differential SPLUNC1 suppression between the eosinophilic and noneosinophilic CRSwNP subsets suggests that they possess distinct pathogenic mechanisms. This finding might benefit the design of appropriate therapeutic interventions targeted to each subset.

Atherosclerosis and venous thromboembolism — similarities

Copyright © Polskie Towarzystwo Kardiologiczne INTRODUCTION Venous thromboembolism (VTE), encompassing deep vein thrombosis (DVT) and pulmonary embolism (PE), and atherothrombosis have long been considered to be separate entities with distinct pathogenic mechanisms. The traditional rationale for this concept has been based on: (1) pathologic data showing platelet-rich thrombi in the arteries in contrast to ‘red clots’ observed in veins; (2) clinical data on a substantial efficacy of antiplatelet agents in the prevention of arterial thromboembolic events in contrast to negligible benefits from these drugs in patients with VTE; (3) experimental data demonstrating diffuse inflammatory infiltrates, extracellular cholesterol deposits, neovessel formation and calcification within advanced atherosclerotic lesions within the arterial wall in contrast to minor lesions largely within the endothelial layer of the thrombosed veins. A key component of this concept is the assumption that deranged local processes occurring inside the vessel wall account for arterial thrombosis with a minor contribution by blood-borne abnormalities, whereas a combination of extrinsic factors ranging from venous blood stasis to hypercoagulable blood that act on a normal wall of a vein determine the occurrence of venous thrombosis. Experimental data derived from biochemical laboratories, cell cultures and animal models has shown however many similarities in the pathophysiology of arterial and venous thrombosis [1]. Coagulation pathways and their regulation are in fact identical in arteries and veins. Blood circulating in the two types of vessels is the same in terms of coagulation proteins. All kinds of thrombosis are triggered with the same major physiological initiator of blood coagulation, i.e. tissue factor (TF) [2]. Finally, thrombus composition assessed following thrombectomy in patients with ST-segment elevation acute myocardial infarction (MI) is frequently hard to differentiate from that of thrombi obtained from thrombosed veins, as evidenced by the fact that fibrin represents the largest portion of the thrombotic mass in both types of vessels [3, 4]. Despite the key role of activated platelets as a driving factor of thrombus formation under high shear stress conditions, there is convincing evidence for a significant contribution of thrombin and blood coagulation proteins in arterial thrombosis, as well as for their expression in macrophages and other cells within atherosclerotic lesions [5]. Until the beginning of the current century, there was no clinical data to support basic science findings indicating that thrombus formation in most vessels follows the same pattern and once deranged haemostasis tilted toward thrombosis results in increased risk of thromboembolic events putting in danger both the arterial and venous beds. Within the last decade, accumulating evidence has indicated that patients following VTE are at risk of MI or ischaemic stroke and vice versa. However a lot of experimental and clinical questions are to be answered including those as to whether all affected patients are indeed prone to develop the other type of thrombosis and which diagnostic and therapeutic strategy should be adopted in such a clinical setting. This review summarises the most important clinical and experimental data on the association between arterial and venous thrombosis.

The ZZ Domain of Dystrophin in DMD: Making Sense of Missense Mutations

Duchenne muscular dystrophy (DMD) is associated with the loss of dystrophin, which plays an important role in myofiber integrity via interactions with β-dystroglycan and other members of the transmembrane dystrophin-associated protein complex. The ZZ domain, a cysteine-rich zinc-finger domain near the dystrophin C-terminus, is implicated in forming a stable interaction between dystrophin and β-dystroglycan, but the mechanism of pathogenesis of ZZ missense mutations has remained unclear because not all such mutations have been shown to alter β-dystroglycan binding in previous experimental systems. We engineered three ZZ mutations (p.Cys3313Phe, p.Asp3335His, and p.Cys3340Tyr) into a short construct similar to the Dp71 dystrophin isoform for in vitro and in vivo studies and delineated their effect on protein expression, folding properties, and binding partners. Our results demonstrate two distinct pathogenic mechanisms for ZZ missense mutations. The cysteine mutations result in diminished or absent subsarcolemmal expression because of protein instability, likely due to misfolding. In contrast, the aspartic acid mutation disrupts binding with β-dystroglycan despite an almost normal expression at the membrane, confirming a role for the ZZ domain in β-dystroglycan binding but surprisingly demonstrating that such binding is not required for subsarcolemmal localization of dystrophin, even in the absence of actin binding domains.

“Plasma Cell Hepatitis” in Liver Allografts: Identification and Characterization of an IgG4-Rich Cohort

Plasma cell hepatitis (PCH), also known as “de novo autoimmune” hepatitis, is an increasingly recognized, but suboptimally named and poorly understood, category of late allograft dysfunction strongly resembling autoimmune hepatitis (AIH): They share plasma-cell-rich necro-inflammatory activity on biopsy, autoantibodies and steroid responsiveness, but overlap with rejection is problematic. A retrospective study of clinical, serological, histopathological and IgG4 immunohistological features of PCH (n = 20) in liver allograft recipients, native liver AIH (n = 19) and plasma-cell-rich renal allograft rejection (n = 20) showed: (1) high frequency (44%) of HLA-DR15; (2) less female predominance (p = 0.03) and (3) n = 9/20 PCH recipients showed >25 IgG4+ plasma cells/high-power field (IgG4+ PCH) versus AIH (n = 1/19, p = 0.008) or plasma-cell-rich kidney rejection (n = 2/20, p = 0.03). The IgG4+ PCH (n = 9) subgroup showed lower alanine transaminase (ALT) (p < 0.01) and aspartate transaminase (AST) (p < 0.05) at index biopsy but (a) higher plasma cell number/percentage, (b) more aggressive-appearing portal/periportal and perivenular necro-inflammatory activity and (c) more severe portal/periportal fibrosis than IgG4− PCH (n = 11). Significant demographic, histopathologic and plasma cell phenotype differences between PCH and AIH suggest distinct pathogenic mechanisms for at least the IgG4+ PCH subgroup likely representing an overlap between allo- and auto-immunity. IgG4+ PCH was associated with fibrosis, but also highly responsive to increased immunosuppression.

Differences in vascular reactivity between pregnant women with chronic hypertension and preeclampsia

The purpose of this study was to evaluate the distinct pathogenic mechanisms underlying chronic hypertension in pregnancy and preeclampsia in terms of oxidative stress and vascular reactivity. A total of 17 women with uncomplicated pregnancies, 30 women with preeclampsia and 17 women with chronic hypertension were evaluated. We measured serum derivatives of reactive oxygen metabolites (d-ROMs; marker of oxygen free radicals), flow-mediated vasodilation (FMD; marker of endothelial function) and intima-media thickness in the carotid artery (IMT; marker of atherogenesis) during pregnancy and 1 month after delivery. Serum d-ROM concentrations were significantly higher in women with chronic hypertension and severe preeclampsia than in the control group during pregnancy. d-ROM concentrations in all groups significantly decreased to similar levels 1 month after delivery. FMD was significantly lower during pregnancy in preeclamptic and chronic hypertension groups compared with the control group. FMD in preeclamptic groups significantly increased and normalized to control levels after delivery. Similarly, FMD in the chronic hypertension group significantly increased after delivery but was still lower. IMT in the chronic hypertension group was significantly higher than that in control and preeclamptic groups. These findings suggest that endothelial dysfunction induced by enhanced oxidative stress is reversible in women with preeclampsia, whereas impaired vascular reactivity may be associated with atherosclerotic changes in women with chronic hypertension.

Ambient Air Pollution and Preeclampsia: A Spatiotemporal Analysis

Background: Available evidence concerning the association between air pollution and preeclampsia is limited, and specific associations with early- and late-onset preeclampsia have not been assessed.Objectives: We investigated the association, if any, between preeclampsia (all, early-, and late-onset) and exposure to nitrogen dioxide, nitrogen oxides, particulate matter with aerodynamic diameter ≤ 2.5 μm (PM2.5; fine particles), ≤ 10 μm, and 2.5–10 μm, and PM2.5 light absorption (a proxy for elemental carbon) during the entire pregnancy and during the first, second, and third trimesters.Methods: This study was based on 8,398 pregnancies (including 103 cases of preeclampsia) among women residing in Barcelona, Spain (2000–2005). We applied a spatiotemporal exposure assessment framework using land use regression models to predict ambient pollutant levels during each week of pregnancy at the geocoded residence address of each woman at the time of birth. Logistic and conditional logistic regression models were used to estimate unadjusted and adjusted associations.Results: We found positive associations for most of our evaluated outcome–exposure pairs, with the strongest associations observed for preeclampsia and late-onset preeclampsia in relation to the third-trimester exposure to fine particulate pollutants, and for early-onset preeclampsia in relation to the first-trimester exposure to fine particulate pollutants. Among our investigated associations, those of first- and third-trimester exposures to PM2.5 and third-trimester exposure to PM2.5 absorbance and all preeclampsia, and third-trimester PM2.5 exposure and late-onset preeclampsia attained statistical significance.Conclusion: We observed increased risk of preeclampsia associated with exposure to fine particulate air pollution. Our findings, in combination with previous evidence suggesting distinct pathogenic mechanisms for early- and late-onset preeclampsia, support additional research on this topic.Citation: Dadvand P, Figueras F, Basagaña X, Beelen R, Martinez D, Cirach M, Schembari A, Hoek G, Brunekreef B, Nieuwenhuijsen MJ. 2013. Ambient air pollution and preeclampsia: a spatiotemporal analysis. Environ Health Perspect 121:1365–1371; http://dx.doi.org/10.1289/ehp.1206430

Bone cysts after osteochondral allograft repair of cartilage defects in goats suggest abnormal interaction between subchondral bone and overlying synovial joint tissues

The efficacy of osteochondral allografts (OCAs) may be affected by osseous support of the articular cartilage, and thus affected by bone healing and remodeling in the OCA and surrounding host. Bone cysts, and their communication pathways, may be present in various locations after OCA insertion and reflect distinct pathogenic mechanisms. Previously, we analyzed the effect of OCA storage (FRESH, 4°C/14d, 4°C/28d, FROZEN) on cartilage quality in fifteen adult goats after 12months in vivo. The objectives of this study were to further analyze OCAs and contralateral non-operated (Non-Op) CONTROLS from the medial femoral condyle to (1) determine the effect of OCA storage on local subchondral bone (ScB) and trabecular bone (TB) structure, (2) characterize the location and structure of bone cysts and channels, and (3) assess the relationship between cartilage and bone properties. (1) Overall bone structure after OCAs was altered compared to Non-Op, with OCA samples displaying bone cysts, ScB channels, and ScB roughening. ScB BV/TV in FROZEN OCAs was lower than Non-Op and other OCAs. TB BV/TV in FRESH, 4°C/14d, and 4°C/28d OCAs did not vary compared to Non-Op, but BS/TV was lower. (2) OCAs contained “basal” cysts, localized to deeper regions, some “subchondral” cysts, localized near the bone–cartilage interface, and some ScB channels. TB surrounding basal cysts exhibited higher BV/TV than Non-Op. (3) Basal cysts occurred (a) in isolation, (b) with subchondral cysts and ScB channels, (c) with ScB channels, or (d) with subchondral cysts, ScB channels, and ScB erosion. Deterioration of cartilage gross morphology was strongly associated with abnormal μCT bone structure. Evidence of cartilage–bone communication following OCA repair may favor fluid intrusion as a mechanism for subchondral cyst formation, while bone resorption at the graft–host interface without affecting overall bone and cartilage structure may favor bony contusion mechanism for basal cyst formation. These findings suggest that cysts occurring after OCAs may result from aberrant mechanobiology due to (1) altered compartmentalization that normally separates overlying cartilage and subchondral bone, either from distinct ScB channels or more general ScB plate deterioration, and (2) bone resorption at the basal graft–host interface.

Tumor-related Lipid Exudation and Associated Tumor-related Complications after Plaque Radiotherapy of Posterior Uveal Melanoma

To identify complications associated with tumor-related lipid exudation (TRLE) after plaque radiotherapy of posterior uveal melanoma. Comparative study including 294 patients with posterior uveal melanoma who developed TRLE after plaque radiotherapy (TRLE group) and 294 patients who did not develop TRLE (non-TRLE group). Patients in the TRLE group were matched with patients in the non-TRLE group for age, gender, and initial tumor thickness. The TRLE group was associated with significantly higher incidence of postradiation complications including early transient increase of serous retinal detachment (p<0.001), iris neovascularization (NVI) (p<0.001), neovascular glaucoma (NVG) (p<0.001), posterior synechia (p<0.001), vitreous hemorrhage (p<0.001), subretinal hemorrhage (p<0.001), and retinoschisis (p<0.001). A significant relationship was found between extent of TRLE and NVI (p<0.001), NVG (p<0.001), posterior synechia (p = 0.007), and retinoschisis over tumor (p = 0.010). Radiation-induced retinopathy, maculopathy, and papillopathy were not associated with presence or extent of TRLE. Tumor-related lipid exudation was also associated with worse final visual acuity (p = 0.011), higher rate of secondary enucleation (p<0.001), and lower rate of systemic metastasis (p = 0.006). Tumor-related lipid exudation following plaque radiotherapy of posterior uveal melanoma is associated with major intraocular complications and portends poor prognosis for final visual acuity and eye retention. These findings provide evidence for the presence of 2 distinct pathogenic mechanisms, one radiation-induced and one tumor-related, in development of postradiation complications in eyes with posterior uveal melanoma.

Distinct mechanisms of axonal globule formation in mice expressing human wild type α-synuclein or dementia with Lewy bodies-linked P123H ß-synuclein

BackgroundAxonopathy is critical in the early pathogenesis of neurodegenerative diseases, including Parkinson’s disease (PD) and dementia with Lewy bodies (DLB). Axonal swellings such as globules and spheroids are a distinct feature of axonopathy and our recent study showed that transgenic (tg) mice expressing DLB-linked P123H β-synuclein (P123H βS) were characterized by P123H βS-immunoreactive axonal swellings (P123H βS-globules). Therefore, the objectives of this study were to evaluate α-synuclein (αS)-immunoreactive axonal swellings (αS-globules) in the brains of tg mice expressing human wild-type αS and to compare them with the globules in P123H βS tg mice.ResultsIn αS tg mice, αS-globules were formed in an age-dependent manner in various brain regions, including the thalamus and basal ganglia. These globules were composed of autophagosome-like membranous structures and were reminiscent of P123H βS-globules in P123H βS tg mice. In the αS-globules, frequent clustering and deformation of mitochondria were observed. These changes were associated with oxidative stress, based on staining of nitrated αS and 4-hydroxy-2-nonenal (4-HNE). In accord with the absence of mitochondria in the P123H βS-globules, staining of nitrated αS and 4-HNE in these globules was weaker than that for αS-globules. Leucine-rich repeat kinase 2 (LRRK2), the PARK8 of familial PD, was detected exclusively in αS-globules, suggesting a specific role of this molecule in these globules.ConclusionsLysosomal pathology was similarly observed for both αS- and P123H βS-globules, while oxidative stress was associated with the αS-globules, and to a lesser extent with the P123H βS-globules. Other pathologies, such as mitochondrial alteration and LRRK2 accumulation, were exclusively detected for αS-globules. Collectively, both αS- and P123H βS-globules were formed through similar but distinct pathogenic mechanisms. Our findings suggest that synuclein family members might contribute to diverse axonal pathologies.

Obstetric Nephrology

AKI in pregnancy remains a cause of significant fetomaternal mortality and morbidity, particularly in developing countries. Hypertensive complications of pregnancy (preeclampsia/eclampsia or hemolysis, elevated liver enzymes, and low platelets count syndrome) are the leading cause of AKI in pregnancy worldwide. Thrombotic microangiopathy is another peculiar and devastating cause of AKI in pregnancy. During the last decade, our understanding, and in some cases, our management, of these causes of AKI in pregnancy has dramatically improved. For instance, convincing data have linked pre-eclampsia/eclampsia to an increase in circulating antiangiogenic factors soluble Flt 1 and endoglin, which induce endothelial cell dysfunction, hypertension, and proteinuria. Several distinct pathogenic mechanisms underlying thrombotic microangiopathy, including thrombotic microangiopathy occurring during pregnancy, have been established. Thrombotic microangiopathy, which can present as hemolytic uremic syndrome or thrombotic thrombocytopenic purpura, can be reclassified in four potentially overlapping subtypes: disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 deficiency-related thrombotic microangiopathy, complement alternative pathway dysregulation-related thrombotic microangiopathy, secondary thrombotic microangiopathy (verotoxin and antiangiogenic drugs), and thrombotic microangiopathy of undetermined mechanism. In most cases, pregnancy is only a precipitating factor for thrombotic microangiopathy. Treatment of thrombotic microangiopathy occurring during pregnancy should be tailored to the underlying pathogenic mechanism: (1) restoration of a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 serum activity in the setting of thrombotic thrombocytopenic purpura through plasma exchanges and in some cases, B cell-depleting therapy and (2) inhibition of complement alternative pathway activation in atypical hemolytic uremic syndrome using antiC5 blocking antibody (eculizumab).

Integrating Genetics and Genomics in Primary Aldosteronism

Primary aldosteronism (PA) is the most common form of secondary hypertension, with an estimated prevalence of ≈10% in referred patients and 4% in primary care1,2 but as high as 20% in patients with resistant hypertension.3,4 It is characterized by hypertension with low plasma renin and elevated aldosterone that is often seen with hypokalemia. PA occurs as a result of a dysregulation of the normal mechanisms controlling adrenal aldosterone production. The 2 major causes are aldosterone-producing adenomas (APAs) and bilateral adrenal hyperplasia (BAH), also called idiopathic hyperaldosteronism. The early detection of PA has an enormous impact on clinical outcome and survival, given the major cardiovascular adverse effects of aldosterone excess, which are independent of blood pressure,5,6 and predict outcome after surgical treatment.7,8 Patients with PA have a significantly higher risk of nonfatal myocardial infarction, atrial fibrillation, and stroke compared with age-, sex-, and blood pressure–matched essential hypertensives.5 Furthermore, changes in cardiac structure and function9 and partially reversible renal dysfunction10 have been described, whereas the increased occurrence of metabolic abnormalities in patients with PA is still a matter of debate.11,12 Although the 2008 guidelines for the management of PA have been pivotal for homogenizing screening procedures and treatment among specialized centers,13 there remain a few critical issues related to diagnosis, subtype differentiation, and treatment of nonsurgically correctable forms. Reliable diagnostic and prognostic biomarkers are lacking for more sensitive and specific screening, as well as new therapeutic avenues, because medical and/or surgical treatment of PA leads to normotension in only a minority of patients. This may come from a better understanding of the pathogenic mechanisms of the disease, in particular, identification of the genetic and molecular determinants leading to the development of APA and …