Department of Biological Sciences

Amyloid diseases are global epidemics with profound health, social and economic implications and yet remain without a cure. This dire situation calls for research into the origin and pathological manifestations of amyloidosis to stimulate continued development of new therapeutics. In basic science and engineering, the cross-β architecture has been a constant thread underlying the structural characteristics of pathological and functional amyloids, and realizing that amyloid structures can be both pathological and functional in nature has fuelled innovations in artificial amyloids, whose use today ranges from water purification to 3D printing. At the conclusion of a half century since Eanes and Glenner's seminal study of amyloids in humans, this review commemorates the occasion by documenting the major milestones in amyloid research to date, from the perspectives of structural biology, biophysics, medicine, microbiology, engineering and nanotechnology. We also discuss new challenges and opportunities to drive this interdisciplinary field moving forward.

Focal adhesions (FAs) are mechanosensitive adhesion and signaling complexes that grow and change composition in response to myosin II-mediated cytoskeletal tension in a process known as FA maturation. To understand tension-mediated FA maturation, we sought to identify proteins that are recruited to FAs in a myosin II-dependent manner and to examine the mechanism for their myosin II-sensitive FA association. We find that FA recruitment of both the cytoskeletal adapter protein vinculin and the tyrosine kinase FA kinase (FAK) are myosin II and extracellular matrix (ECM) stiffness dependent. Myosin II activity promotes FAK/Src-mediated phosphorylation of paxillin on tyrosines 31 and 118 and vinculin association with paxillin. We show that phosphomimic mutations of paxillin can specifically induce the recruitment of vinculin to adhesions independent of myosin II activity. These results reveal an important role for paxillin in adhesion mechanosensing via myosin II-mediated FAK phosphorylation of paxillin that promotes vinculin FA recruitment to reinforce the cytoskeletal ECM linkage and drive FA maturation.

Systematic reviews and pairwise meta-analyses of randomized controlled trials, at the intersection of clinical medicine, epidemiology and statistics, are positioned at the top of evidence-based practice hierarchy. These are important tools to base drugs approval, clinical protocols and guidelines formulation and for decision-making. However, this traditional technique only partially yield information that clinicians, patients and policy-makers need to make informed decisions, since it usually compares only two interventions at the time. In the market, regardless the clinical condition under evaluation, usually many interventions are available and few of them have been studied in head-to-head studies. This scenario precludes conclusions to be drawn from comparisons of all interventions profile (e.g. efficacy and safety). The recent development and introduction of a new technique - usually referred as network meta-analysis, indirect meta-analysis, multiple or mixed treatment comparisons - has allowed the estimation of metrics for all possible comparisons in the same model, simultaneously gathering direct and indirect evidence. Over the last years this statistical tool has matured as technique with models available for all types of raw data, producing different pooled effect measures, using both Frequentist and Bayesian frameworks, with different software packages. However, the conduction, report and interpretation of network meta-analysis still poses multiple challenges that should be carefully considered, especially because this technique inherits all assumptions from pairwise meta-analysis but with increased complexity. Thus, we aim to provide a basic explanation of network meta-analysis conduction, highlighting its risks and benefits for evidence-based practice, including information on statistical methods evolution, assumptions and steps for performing the analysis.

INTRODUCTION: Periodontal disease is a chronic inflammation of the attachment structures of the teeth, triggered by potentially hazardous microorganisms and the consequent immune-inflammatory responses. In humans, the T helper type 17 (Th17) lineage, characterized by interleukin-17 (IL-17) production, develops under transforming growth factor-beta (TGF-beta), IL-1beta, and IL-6 signaling, while its pool is maintained by IL-23. Although this subset of cells has been implicated in various autoimmune, inflammatory, and bone-destructive conditions, the exact role of T lymphocytes in chronic periodontitis is still controversial. Therefore, in this study we investigated the presence of Th17 cells in human periodontal disease. METHODS: Gingival and alveolar bone samples from healthy patients and patients with chronic periodontitis were collected and used for the subsequent assays. The messenger RNA expression for the cytokines IL-17, TGF-beta, IL-1beta, IL-6, and IL-23 in gingiva or IL-17 and receptor activator for nuclear factor-kappaB ligand in alveolar bone was evaluated by real-time polymerase chain reaction. The production of IL-17, TGF-beta, IL-1beta, IL-6, and IL-23 proteins was evaluated by immunohistochemistry and the presence of Th17 cells in the inflamed gingiva was confirmed by immunofluorescence confocal microscopy for CD4 and IL-17 colocalization. RESULTS: Our data demonstrated elevated levels of IL-17, TGF-beta, IL-1beta, IL-6, and IL-23 messenger RNA and protein in diseased tissues as well as the presence of Th17 cells in gingiva from patients with periodontitis. Moreover, IL-17 and the bone resorption factor RANKL were abundantly expressed in the alveolar bone of diseased patients, in contrast to low detection in controls. CONCLUSION: These results provided strong evidence for the presence of Th17 cells in the sites of chronic inflammation in human periodontal disease.

Expression of enzymatically inactive caspase-8, or deletion of caspase-8 from basal epidermal keratinocytes, triggers chronic skin inflammation in mice. Unlike similar inflammation resulting from arrest of nuclear factor kappaB activation in the epidermal cells, the effect induced by caspase-8 deficiency did not depend on TNF, IL-1, dermal macrophage function, or expression of the toll-like receptor adapter proteins MyD88 or TRIF. Both interferon regulatory factor (IRF) 3 and TANK-binding kinase were constitutively phosphorylated in the caspase-8-deficient epidermis, and knockdown of IRF3 in the epidermis-derived cells from these mice abolished the expression of up-regulated genes. Temporal and spatial analyses of the alterations in gene expression that result from caspase-8 deficiency reveal that the changes are initiated before birth, around the time that cornification develops, and occur mainly in the suprabasal layer. Finally, we found that caspase-8-deficient keratinocytes display an enhanced response to gene activation by transfected DNA. Our findings suggest that an enhanced response to endogenous activators of IRF3 in the epidermis, presumably generated in association with keratinocyte differentiation, contributes to the skin inflammatory process triggered by caspase-8 deficiency.

BACKGROUND: Atopic dermatitis (AD) is the leading cause of the global burden from skin disease; no study has provided global and country-specific epidemiological estimates of AD. OBJECTIVES: To quantify global, regional and country-specific estimates of the epidemiology of AD. METHODS: A comprehensive search for epidemiological studies in AD was conducted in four electronic databases (PubMed, Embase, Web of Science and China National Knowledge Infrastructure). A Bayesian hierarchical linear mixed model was constructed to calculate epidemiological estimates of AD considering the heterogeneity of regions, countries, type of diagnoses and age strata. RESULTS: In total, 344 studies met the inclusion criteria. Incidence varied substantially with the location and age of the surveyed participants. The global prevalence of AD and the population affected by AD were estimated to be 2.6% [95% uncertainty interval (UI) 1.9-3.5] and 204.05 million people, respectively. Around 101.27 million adults and 102.78 million children worldwide have AD, corresponding to prevalence rates of 2.0% (95% UI 1.4-2.6) and 4.0% (95% UI 2.8-5.3), respectively. Females were more likely to suffer from AD than males: the global prevalence of AD in females was 2.8% (95% UI 2.0-3.7%) and affected 108.29 million people, while in males the corresponding estimates were 2.4% (95% UI 1.7-3.3%) and 95.76 million people. CONCLUSIONS: Epidemiological AD data are lacking in 41.5% of countries worldwide. The epidemiology of AD varies substantially with age and sex and is distributed unequally across geographical regions.

OBJECT: The objectives of this study were twofold: (1) to examine the prevalence of emotional symptoms among children and adolescents with a sports-related concussion (SRC) who were referred to a multidisciplinary pediatric concussion program and (2) to examine the prevalence, clinical features, risk factors, and management of postinjury psychiatric outcomes among those in this clinical population. METHODS: The authors conducted a retrospective chart review of all patients with SRC referred to a multidisciplinary pediatric concussion program between September 2013 and October 2014. Clinical assessments carried out by a single neurosurgeon included clinical history, physical examination, and Post-Concussion Symptom Scale (PCSS) scoring. Postinjury psychiatric outcomes were defined as a subjective worsening of symptoms of a preinjury psychiatric disorder or new and isolated suicidal ideation or diagnosis of a novel psychiatric disorder (NPD). An NPD was defined as a newly diagnosed psychiatric disorder that occurred in a patient with or without a lifetime preinjury psychiatric disorder after a concussion. Clinical resources, therapeutic interventions, and clinical and return-to-play outcomes are summarized. RESULTS: One hundred seventy-four patients (mean age 14.2 years, 61.5% male) were included in the study. At least 1 emotional symptom was reported in 49.4% of the patients, and the median emotional PCSS subscore was 4 (interquartile range 1-8) among those who reported at least 1 emotional symptom. Overall, 20 (11.5%) of the patients met the study criteria for a postinjury psychiatric outcome, including 14 patients with an NPD, 2 patients with isolated suicidal ideation, and 4 patients with worsening symptoms of a preinjury psychiatric disorder. Female sex, a higher initial PCSS score, a higher emotional PCSS subscore, presence of a preinjury psychiatric history, and presence of a family history of psychiatric illness were significantly associated with postinjury psychiatric outcomes. Interventions for patients with postinjury psychiatric outcomes included pharmacological therapy alone in 2 patients (10%), cognitive behavioral therapy alone in 4 (20%), multimodal therapy in 9 (45%), and no treatment in 5 (25%). Overall, 5 (25%) of the patients with postinjury psychiatric disorders were medically cleared to return to full sports participation, whereas 5 (25%) were lost to follow-up and 9 (45%) remained in treatment by the multidisciplinary concussion program at the end of the study period. One patient who was asymptomatic at the time of initial consultation committed suicide. CONCLUSIONS: Emotional symptoms were commonly reported among pediatric patients with SRC referred to a multidisciplinary pediatric concussion program. In some cases, these symptoms contributed to the development of an NPD, isolated suicidal ideation, and worsening symptoms of a preexisting psychiatric disorder. Future research is needed to clarify the prevalence, pathophysiology, risk factors, and evidence-based management of postinjury psychiatric outcomes after pediatric SRC. Successful management of these patients requires prompt recognition and multidisciplinary care by experts with clinical training and experience in concussion and psychiatry.

Abstract Three high molecular weight polycaprolactones (M̄ w = 35,000, 18,600, and 7,130) were utilized as the sole carbon source by five of six fungi tested by the American Standards for Testing and Materials (ASTM) agar plate method. The fungi were Aspergillus flavus, A. niger, A. fumigatus, Chaetomium globosum, Pencillium funiculosum , and a Fusarium sp. Quantitative analysis of degradation was performed using gel permeation chromatography (GPC). GPC analysis demonstrated differences between the activities of organisms which appeared similar by the ASTM method, and showed that, while all molecular weight species within each polymer were hydrolyzed, in several cases low molecular weight end products were not assimilated. Depending on the organism, the dominant factor determining degradability was either polymer molecular weight or degree of crystallinity.

BACKGROUND: Aggressive periodontitis is a specific form of periodontal disease that is characterized by rapid attachment loss and bone destruction. Cytokine profiles are of considerable value when studying disease course during treatment. The aim of this trial was to investigate cytokine levels in the gingival crevicular fluid (GCF) of patients with aggressive periodontitis, after treatment with photodynamic therapy (PDT) or scaling and root planing (SRP), in a split-mouth design on -7, 0, +1, +7, +30, and +90 days. METHODS: Ten patients were randomly treated with PDT using a laser source associated with a photosensitizer or SRP with hand instruments. GCF samples were collected, and the concentrations of tumor necrosis factor-alpha (TNF-alpha) and receptor activator of nuclear factor-kappa B ligand (RANKL) were determined by enzyme-linked immunosorbent assays. The data were analyzed using generalized estimating equations to test the associations among treatments, evaluated parameters, and experimental times (alpha = 0.05). RESULTS: Non-surgical periodontal treatment with PDT or SRP led to statistically significant reductions in TNF-alpha level 30 days following treatment. There were similar levels of TNF-alpha and RANKL at the different time points in both groups, with no statistically significant differences. CONCLUSION: SRP and PDT had similar effects on crevicular TNF-alpha and RANKL levels in patients with aggressive periodontitis.

Abstract The degradability of three high molecular weight polycaprolactones (M̄ w = 35,000, 18,600, and 7,130) and one low molecular weight polycaprolactone diol(M̄ w = 2060) by mixed and pure cultures of microorganisms was assayed. A yeast, Cryptococcus laurentii , a gram‐negative rod, Acinetobacter calcoaceticus var. lwoffi , and a gram‐positive coryneform rod were used in the pure culture assays. The analysis of degradation by gel permation chromatography (GPC) allowed for quantitation independent of the growth of the organisms or the addition of supplementary growth factors. GPC analysis showed that the degradation effected by pure cultures was often enhanced when alternate carbon sources were present. This was not the case for mixed cultures. Mixed cultures. Mixed cultures completely metabolized polymer breakdown products while in some cases pure cultures did not.

RATIONALE: Annual computed tomography (CT) is now widely recommended for lung cancer screening in the United States, although concerns remain regarding the potential harms, including those from overdiagnosis. OBJECTIVES: To examine the effect of airflow limitation on overdiagnosis by comparing lung cancer incidence, histology, and stage shift in a subgroup of the National Lung Screening Trial (NLST). METHODS: In an NLST subgroup (n = 18,714), screening participants were randomized to annual computed tomography (CT, n = 9,357) or chest radiograph (n = 9,357) screening and monitored for a mean of 6.1 years. After baseline prebronchodilator spirometry, to identify the presence of airflow limitation, 18,475 subjects (99%) were assigned as having chronic obstructive pulmonary disease (COPD) or no COPD. Lung cancer prevalence, incidence, histology, and stage shift were compared after stratification by COPD. MEASUREMENTS AND MAIN RESULTS: For screening participants with spirometric COPD (n = 6,436), there was a twofold increase in lung cancer incidence (incident rate ratio, 2.15; P < 0.001) and, when compared according to screening arm, no excess lung cancers and comparable histology. Compared with chest radiography, there was also a trend favoring reduced late-stage and increased early-stage cancers in the CT arm (P = 0.054). For those with normal baseline spirometry (n = 12,039), we found an excess of lung cancers during screening in the CT arm, almost exclusively early-stage adenocarcinoma-related cancers (histology shift and overdiagnosis). After correction for these excess cancers, stage shift was marginal (P = 0.077). CONCLUSIONS: In the CT arm of the NLST-ACRIN (American College of Radiology Imaging Network) cohort, COPD status was associated with a doubling of lung cancer incidence, no apparent overdiagnosis, and a more favorable stage shift.

Abstract This paper addresses the issue of forecasting individual items within a product line; where each line includes several independent but closely related products. The purpose of the research was to reduce the overall forecasting burden by developing and assessing schemes of disaggregating forecasts of a total product line to the related individual items. Measures were developed to determine appropriate disaggregated methodologies and to compare the forecast accuracy of individual product forecasts versus disaggregated totals. Several of the procedures used were based upon extensions of the combination of forecast research and applied to disaggregations of total forecasts of product lines. The objective was to identify situations when it was advantageous to produce disaggregated forecasts, and if advantageous, which method of disaggregation to utilize. This involved identification of the general conceptual characteristics within a set of product line data that might cause a disaggregation method to produce relatively accurate forecasts. These conceptual characteristics provided guidelines for forecasters on how to select a disaggregation method and under what conditions a particular method is applicable.

AIM: To compare the effectiveness of mineral trioxide aggregate (MTA), calcium hydroxide (CH) and formocresol (FC) as pulp dressing agents in carious primary teeth. METHODOLOGY: Forty-five primary mandibular molars with dental caries in 23 children [AUTHOR QUERY: How many children?] between 5 and 9 years old were treated by a conventional pulpotomy technique. The teeth were randomly assigned to the experimental (CH or MTA) or control (FC) groups. After coronal pulp removal and haemostasis, remaining pulp tissue was covered with MTA paste or CH powder in the experimental groups. In the control group, diluted FC was placed with a cotton pellet over the pulp tissue for 5 min and removed; the pulp tissue was then covered with zinc oxide-eugenol (ZOE) paste. All teeth were restored with reinforced ZOE base and resin modified glass-ionomer cement. Clinical and radiographic successes and failures were recorded at 3, 6, 12, 18 and 24 month follow-up. RESULTS: Forty-three teeth were available for follow-up. In the FC and MTA groups, 100% of the available teeth were clinically and radiographically successful at all follow-up appointments; dentine bridge formation could be detected in 29% of the teeth treated with MTA. In the CH group, 64% of the teeth presented clinical and radiographic failures detected throughout the follow-up period, and internal resorption was a frequent radiographic finding. CONCLUSIONS: Mineral trioxide aggregate was superior to CH and equally as effective as FC as a pulpotomy dressing in primary mandibular molars. Internal resorption was the most common radiographic finding up to 24 month after pulpotomies performed with CH.

The cellular prion protein (PrP(C)) is essential for the pathogenesis and transmission of prion diseases. PrP(C) is bound to the plasma membrane via a glycosylphosphatidylinositol anchor, although a secreted, soluble form has also been identified. Previously we reported that PrP(C) is subject to ectodomain shedding from the membrane by zinc metalloproteinases with a similar inhibition profile to those involved in shedding the amyloid precursor protein. Here we have used gain-of-function (overexpression) and loss-of-function (small interfering RNA knockdown) experiments in cells to identify the ADAMs (a disintegrin and metalloproteinases) involved in the ectodomain shedding of PrP(C). These experiments revealed that ADAM9 and ADAM10, but not ADAM17, are involved in the shedding of PrP(C) and that ADAM9 exerts its effect on PrP(C) shedding via ADAM10. Using dominant negative, catalytically inactive mutants, we show that the catalytic activity of ADAM9 is required for its effect on ADAM10. Mass spectrometric analysis revealed that ADAM10, but not ADAM9, cleaved PrP between Gly(228) and Arg(229), three residues away from the site of glycosylphosphatidylinositol anchor attachment. The shedding of another membrane protein, the amyloid precursor protein beta-secretase BACE1, by ADAM9 is also mediated via ADAM10. Furthermore, we show that pharmacological inhibition of PrP(C) shedding or activation of both PrP(C) and PrP(Sc) shedding by ADAM10 overexpression in scrapie-infected neuroblastoma N2a cells does not alter the formation of proteinase K-resistant PrP(Sc). Collectively, these data indicate that although PrP(C) can be shed through the action of ADAM family members, modulation of PrP(C) or PrP(Sc) ectodomain shedding does not regulate prion conversion.

Like many other African countries, incidence of drought is increasing in Nigeria. In this work, spatiotemporal changes in droughts under different representative concentration pathway (RCP) scenarios were assessed; considering their greatest impacts on life and livelihoods in Nigeria, especially when droughts coincide with the growing seasons. Three entropy-based methods, namely symmetrical uncertainty, gain ratio, and entropy gain were used in a multi-criteria decision-making framework to select the best performing General Circulation Models (GCMs) for the projection of rainfall and temperature. Performance of four widely used bias correction methods was compared to identify a suitable method for correcting bias in GCM projections for the period 2010-2099. A machine learning technique was then used to generate a multi-model ensemble (MME) of the bias-corrected GCM projection for different RCP scenarios. The standardized precipitation evapotranspiration index (SPEI) was subsequently computed to estimate droughts from the MME mean of GCM projected rainfall and temperature to predict possible spatiotemporal changes in meteorological droughts. Finally, trends in the SPEI, temperature and rainfall, and return period of droughts for different growing seasons were estimated using a 50-year moving window, with a 10-year interval, to understand driving factors accountable for future changes in droughts. The analysis revealed that MRI-CGCM3, HadGEM2-ES, CSIRO-Mk3-6-0, and CESM1-CAM5 are the most appropriate GCMs for projecting rainfall and temperature, and the linear scaling (SCL) is the best method for correcting bias. The MME mean of bias-corrected GCM projections revealed an increase in rainfall in the south-south, southwest, and parts of the northwest whilst a decrease in the southeast, northeast, and parts of central Nigeria. In contrast, rise in temperature for entire country during most of the cropping seasons was projected. The results further indicated that increase in temperature would decrease the SPEI across Nigeria, which will make droughts more frequent in most of the country under all the RCPs. However, increase in drought frequency would be less for higher RCPs due to increase in rainfall.

Abstract Thirty five species of free-living anaerobic flagellates from freshwater and coastal sediments from Danish and Australian sites are reported. These belong to the genera Ancyromonas, Barthelona n. gen., Bodo, Cafeteria, Carpediemonas, Cercomonas, Chilomastix, Chilomonas, Dimastigella, Goniomonas, Heteromita, Jakoba Mastigamoeba, Monotrichomonas n. gen., Paraphysomonas, Percolomonas, Pseudotrichomonas, Quasibodo n. gen., Rhabdomonas, Rhynchobodo, Rhynchomonas, Salpingoeca, Spumella, Trepomonas and Trimastix. Six new species are described, Barthelona vulgaris, Jakoba incarcerata, Mastigamoeba punctachora, Monotrichomonas carabina, Quasibodo laughtoni and Trimastix inaequalis. The composition of the communities encountered under anoxic conditions overlaps with communities observed in aerobic environments and includes species of heteroloboseids, kinetoplastids, euglenids, jakobids, stramenopiles, cercomonads, cryptomonads and choanoflagellates — all of which are mitochondriate. About half of the flagellates observed lack classical mitochondria, or belong to known amitochondriate groups. These taxa are assignable to the pelobionts, retortamonads, diplomonads, trichomonads, and to the genera Trimastix and Carpediemonas. Some taxa observed during this study have no clear identity and further study is necessary. This work confirms the existence of many poorly understood anaerobic flagellates, the study of which could increase our understanding of the pattern of mitochondrial gain and/or loss among extant eukaryotes, as well as the operation of anoxic ecosystems. Key words: anoxic sedimentsAustraliaDenmarkfree-living anaerobic flagellatesProtistataxonomy

The aims of this study were: (1) to correlate surface (SH) and cross-sectional hardness (CSH) with microradiographic parameters of artificial enamel lesions; (2) to compare lesions prepared by different protocols. Fifty bovine enamel specimens were allocated by stratified randomisation according to their initial SH values to five groups and lesions produced by different methods: MC gel (methylcellulose gel/lactic acid, pH 4.6, 14 days); PA gel (polyacrylic acid/lactic acid/hydroxyapatite, pH 4.8, 16 h); MHDP (undersaturated lactate buffer/methyl diphosphonate, pH 5.0, 6 days); buffer (undersaturated acetate buffer/fluoride, pH 5.0, 16 h), and pH cycling (7 days). SH of the lesions (SH(1)) was measured. The specimens were longitudinally sectioned and transverse microradiography (TMR) and CSH measured at 10- to 220-microm depth from the surface. Overall, there was a medium correlation but non-linear and variable relationship between mineral content and radicalCSH. radicalSH(1) was weakly to moderately correlated with surface layer properties, weakly correlated with lesion depth but uncorrelated with integrated mineral loss. MHDP lesions showed the highest subsurface mineral loss, followed by pH cycling, buffer, PA gel and MC gel lesions. The conclusions were: (1) CSH, as an alternative to TMR, does not estimate mineral content very accurately, but gives information about mechanical properties of lesions; (2) SH should not be used to analyse lesions; (3) artificial caries lesions produced by the protocols differ, especially considering the method of analysis.

Alzheimer's disease (AD) is a neurodegenerative disease leading to a progressive and irreversible loss of mental functions. It is characterized by 3 stages according to the evolution and the severity of the symptoms. This disease is associated with an immune disorder, which appears with significant rise in the inflammatory cytokines and increased production of free radicals such as nitric oxide (NO). Our study aims to investigate interferon (IFN)-γ and tumor necrosis factor-α (TNF-α) involvement in NO production, in vivo and ex vivo, in peripheral blood mononuclear cells from Algerian patients (n=25), according to the different stages of the disease (mild Alzheimer's, moderate Alzheimer's, and severe Alzheimer's) in comparison to mild cognitive impairment (MCI) patients. Interestingly, we observed that in vivo IFN-γ and TNF-α levels assessed in patients with AD in mild and severe stages, respectively, are higher than those observed in patients with moderate stage and MCI. Our in vivo and ex vivo results show that NO production is related to the increased levels of IFN-γ and TNF-α, in mild and severe stages of AD. Remarkably, significant IFN-γ level is only detected in mild stage of AD. Our study suggests that NO production is IFN-γ dependent both in MCI and mild Alzheimer's patients. Further, high levels of NO are associated with an elevation of TNF-α levels in severe stage of AD. Collectively, our data indicate that the proinflammatory cytokine production seems, in part, to be involved in neurological deleterious effects observed during the development of AD through NO pathway.

The formation of a functional spindle requires microtubule (MT) nucleation from within the spindle, which depends on augmin. How augmin contributes to MT formation and organization is not known because augmin-dependent MTs have never been specifically visualized. In this paper, we identify augmin-dependent MTs and their connections to other MTs by electron tomography and 3D modeling. In metaphase spindles of human cells, the minus ends of MTs were located both around the centriole and in the body of the spindle. When augmin was knocked down, the latter population of MTs was significantly reduced. In control cells, we identified connections between the wall of one MT and the minus end of a neighboring MT. Interestingly, the connected MTs were nearly parallel, unlike other examples of end–wall connections between cytoskeletal polymers. Our observations support the concept of augmin-dependent MT nucleation at the walls of existing spindle MTs. Furthermore, they suggest a mechanism for maintaining polarized MT organization, even when noncentrosomal MT initiation is widespread.

This review aims at presenting a current view on the physiopathologic mechanisms associated with temporomandibular disorders (TMDs). While joint pain is characterized by a well-defined inflammatory process mediated by tumor necrosis factor-α and interleukin, chronic muscle pain presents with enigmatic physiopathologic mechanisms, being considered a functional pain syndrome similar to fibromyalgia, irritable bowel syndrome, interstitial cystitis and chronic fatigue syndrome. Central sensitization is the common factor unifying these conditions, and may be influenced by the autonomic nervous system and genetic polymorphisms. Thus, TMDs symptoms should be understood as a complex response which might get worse or improve depending on an individual's adaptation.