Correction: Genetic risk for schizophrenia and psychosis in Alzheimer disease.

A number of collaborators were not acknowledged for their contribution to this published article. The acknowledgements that were missing in this published article can now be found in the associated correction.

Genetic risk for schizophrenia and psychosis in Alzheimer disease.

Psychotic symptoms, defined as the occurrence of delusions or hallucinations, are frequent in Alzheimer disease (AD), affecting ~40 to 60% of individuals with AD (AD with psychosis (AD+P)). In comparison with AD subjects without psychosis, AD+P subjects have more rapid cognitive decline and poor outcomes. Prior studies have estimated the heritability of psychosis in AD at 61%, but the underlying genetic sources of this risk are not known. We evaluated a Discovery Cohort of 2876 AD subjects with (N=1761) or without psychosis (N=1115). All subjects were genotyped using a custom genotyping array designed to evaluate single-nucleotide polymorphisms (SNPs) with evidence of genetic association with AD+P and include SNPs affecting or putatively affecting risk for schizophrenia and AD. Results were replicated in an independent cohort of 2194 AD subjects with (N=734) or without psychosis (N=1460). We found that AD+P is associated with polygenic risk for a set of novel loci and inversely associated with polygenic risk for schizophrenia. Among the biologic pathways identified by the associations of schizophrenia SNPs with AD+P are endosomal trafficking, autophagy and calcium channel signaling. To the best of our knowledge, these findings provide the first clear demonstration that AD+P is associated with common genetic variation. In addition, they provide an unbiased link between polygenic risk for schizophrenia and a lower risk of psychosis in AD. This provides an opportunity to leverage progress made in identifying the biologic effects of schizophrenia alleles to identify novel mechanisms protecting against more rapid cognitive decline and psychosis risk in AD.

Experimental antibiotic treatment identifies potential pathogens of white band disease in the endangered Caribbean coral Acropora cervicornis.

Coral diseases have been increasingly reported over the past few decades and are a major contributor to coral decline worldwide. The Caribbean, in particular, has been noted as a hotspot for coral disease, and the aptly named white syndromes have caused the decline of the dominant reef building corals throughout their range. White band disease (WBD) has been implicated in the dramatic loss of Acropora cervicornis and Acropora palmata since the 1970s, resulting in both species being listed as critically endangered on the International Union for Conservation of Nature Red list. The causal agent of WBD remains unknown, although recent studies based on challenge experiments with filtrate from infected hosts concluded that the disease is probably caused by bacteria. Here, we report an experiment using four different antibiotic treatments, targeting different members of the disease-associated microbial community. Two antibiotics, ampicillin and paromomycin, arrested the disease completely, and by comparing with community shifts brought about by treatments that did not arrest the disease, we have identified the likely candidate causal agent or agents of WBD. Our interpretation of the experimental treatments is that one or a combination of up to three specific bacterial types, detected consistently in diseased corals but not detectable in healthy corals, are likely causal agents of WBD. In addition, a histophagous ciliate (Philaster lucinda) identical to that found consistently in association with white syndrome in Indo-Pacific acroporas was also consistently detected in all WBD samples and absent in healthy coral. Treatment with metronidazole reduced it to below detection limits, but did not arrest the disease. However, the microscopic disease signs changed, suggesting a secondary role in disease causation for this ciliate. In future studies to identify a causal agent of WBD via tests of Henle-Koch's postulates, it will be vital to experimentally control for populations of the other potential pathogens identified in this study.

Silver nanoparticles: a microbial perspective.

Silver nanoparticles (NPs) are used for a wide range of commercial reasons to restrict microbial growth. The increasing use of silver NPs in modern materials ensures they will find their way into environmental systems. The mode of action which makes them desirable as an antimicrobial tool could also pose a severe threat to the natural microbial balance existing in these systems. Research into the potential environmental threats of silver NPs has mainly focused on particular areas, such as their influence in rivers and estuaries or their effect on organisms such as earthworms and plants. There is a need to focus studies on all aspects of the microbial world and to highlight potential risks and methods of overcoming problems before significant damage is done. This review focuses on the antimicrobial uses, mechanisms of toxicity, and effects on the environment (mainly soil) of silver NPs, illustrating gaps in current knowledge.

Opposing actions of c-ets/PU.1 and c-myb protooncogene products in regulating the macrophage-specific promoters of the human and mouse colony-stimulating factor-1 receptor (c-fms) genes.

The receptor for macrophage colony stimulating factor (CSF-1), the c-fms gene product, is a key determinant in the differentiation of monocytic phagocytes. Dissection of the human and mouse c-fms proximal promoters revealed opposing roles for nuclear protooncogenes in the transcriptional regulation of this gene. On the one hand, c-ets-1, c-ets-2, and the macrophage-specific factor PU.1, but not the ets-factor PEA3, trans-activated the c-fms proximal promoter. On the other hand c-myb repressed proximal promoter activity in macrophages and blocked the action of c-ets-1 and c-ets-2. Basal c-fms promoter activity was almost undetectable in the M1 leukaemia line, which expressed high levels of c-myb, but was activated as cells differentiated in response to leukemia inhibitory factor and expressed c-fms mRNA. The repressor function of c-myb depended on the COOH-terminal domain of the protein. We propose that ets-factors are necessary for the tissue-restricted expression of c-fms and that c-myb acts to ensure correct temporal expression of c-fms during myeloid differentiation.

Gastro-oesophageal reflux and aspiration in patients with advanced lung disease.

Numerous small observational studies have shown that gastro-oesophageal reflux is prevalent among patients with advanced lung disease. The fundamental concern is that reflux is a risk factor for recurrent microaspiration, which may cause lung injury. For example, in lung transplant patients, a molecular marker of aspiration was a risk factor for the bronchiolitis obliterans syndrome in one study. To date, however, there are no large prospective studies measuring the impact of aspiration on clinical outcomes. The major obstacle limiting the study of reflux and aspiration in patients with advanced lung disease is the absence of a reliable diagnostic tool. Proximal oesophageal acid detection by pH monitoring is the only widely available measure of aspiration risk. Impedance monitoring may be a superior measure of aspiration risk as it measures both acid and non-acid reflux episodes. Molecular markers of aspiration, such as pepsin or bile salts in the bronchoalveolar lavage or exhaled breath condensate, may be the optimal diagnostic tests, but they are not currently available outside the research setting. Larger observational studies are needed to determine the following: (1) the clinical significance of aspiration in patients with advanced lung disease and in patients who have had lung transplantation and (2) the diagnostic test that best predicts adverse outcomes.

Phosphorylation of linker histone is associated with transcriptional activation in a normally silent nucleus.

Previous studies have suggested that micronuclear linker histones are phosphorylated by cAMP-dependent protein kinase (PKA) in Tetrahymena (Sweet, M.T., and C.D. Allis. 1993. Chromosoma. 102: 637-647). In this study, we report that a rapid and dramatic phosphorylation of the micronuclear linker histone, delta, occurs early in the sexual pathway, conjugation. Phosphorylated isoforms of delta are detected as early as 30 min after mixing cells of different mating types; blocking pair formation abolishes this induction completely. Phosphorylation of delta is stimulated by the addition of N6-benzoyladenosine 3':5' cyclic monophosphate to starved (nonmating) cells, suggesting that a PKA/cAMP signal transduction pathway is involved. Maximal phosphorylation of delta is observed during meiotic prophase, a period when micronuclei become transcriptionally active. In situ staining, using phospho-delta-specific antibodies combined with [3H]uridine autoradiography, shows that decondensed micronuclear chromatin undergoing active transcription is enriched in phosphorylated delta isoforms. In contrast, condensed inactive micronuclear chromatin is enriched in dephosphorylated delta. These results strongly suggest that phosphorylation of linker histone plays an important and previously unsuspected role in establishing transcriptional competence in micronuclei.

Minocycline Prevents the Development of Mechanical Allodynia in Mouse Models of Vincristine-Induced Peripheral Neuropathy.

Vincristine is an antineoplastic substance that is part of many chemotherapy regimens, used especially for the treatment of a variety of pediatric cancers including leukemias and brain tumors. Unfortunately, many vincristine-treated patients develop peripheral neuropathy, a side effect characterized by sensory, motoric, and autonomic symptoms. The sensory symptoms include pain, in particular hypersensitivity to light touch, as well as loss of sensory discrimination to detect vibration and touch. The symptoms of vincristine-induced neuropathy are only poorly controlled by currently available analgesics and therefore often necessitate dose reductions or even cessation of treatment. The aim of this study was to identify new therapeutic targets for the treatment of vincristine-induced peripheral neuropathy (VIPN) by combining behavioral experiments, histology, and pharmacology after vincristine treatment. Local intraplantar injection of vincristine into the hind paw caused dose- and time-dependent mechanical hypersensitivity that developed into mechanical hyposensitivity at high doses, and lead to a pronounced, dose-dependent infiltration of immune cells at the site of injection. Importantly, administration of minocycline effectively prevented the development of mechanical hypersensitivity and infiltration of immune cells in mouse models of vincristine induce peripheral neuropathy (VIPN) based on intraperitoneal or intraplantar administration of vincristine. Similarly, Toll-like receptor 4 knockout mice showed diminished vincristine-induced mechanical hypersensitivity and immune cell infiltration, while treatment with the anti-inflammatory meloxicam had no effect. These results provide evidence for the involvement of Toll-like receptor 4 in the development of VIPN and suggest that minocycline and/or direct Toll-like receptor 4 antagonists may be an effective preventative treatment for patients receiving vincristine.

Antireflux surgery for patients with end-stage lung disease before and after lung transplantation.

BACKGROUND: Gastroesophageal reflux disease (GERD) is prevalent among patients with end-stage lung disease (ESLD). This disease can lead to microaspiration and may be a risk factor for lung damage before and after transplantation. A fundoplication is the best way to stop reflux, but little is known about the safety of elective antireflux surgery for patients with ESLD. This study aimed to report the safety of laparoscopic fundoplication for patients with ESLD and GERD before or after lung transplantation. METHODS: Between January 1997 and January 2007, 305 patients were listed for lung transplantation, and 189 patients underwent the procedure. In 2003, routine esophageal studies were added to the pretransplantation evaluation. After the authors' initial experience, gastric emptying studies were added as well. RESULTS: A total of 35 patients with GERD or delayed gastric emptying were referred for surgical intervention. A laparoscopic fundoplication was performed for 32 patients (27 total and 5 partial). For three patients, a pyloroplasty also was performed. Two patients had a pyloroplasty without fundoplication. Of the 35 operations, 15 were performed before and 20 after transplantation. Gastric emptying of solids or liquids was delayed in 12 (92%) of 13 posttransplantation studies and 3 (60%) of 5 pretransplantation studies. All operations were completed laparoscopically, and 33 patients recovered uneventfully (94%). The median hospital length of stay was 2 days (range, 1-34 days) for the patients admitted to undergo elective operations. Hospitalization was not prolonged for the three patients who had fundoplications immediately after transplantation. CONCLUSIONS: The results of this study show that laparoscopic antireflux surgery can be performed safely by an experienced multidisciplinary team for selected patients with ESLD before or after lung transplantation, and that gastric emptying is frequently abnormal and should be objectively measured in ESLD patients.

The use of gamification in the teaching of disease epidemics and pandemics.

With the launch of the teaching excellence framework, teaching in higher education (HE) is under greater scrutiny than ever before. Didactic lecture delivery is still a core element of many HE programmes but there is now a greater expectation for academics to incorporate alternative approaches into their practice to increase student engagement. These approaches may include a large array of techniques from group activities, problem-based learning, practical experience and mock scenarios to newly emerging approaches such as flipped learning practices and the use of gamification. These participatory forms of learning encourage students to become more absorbed within a topic that may otherwise be seen as rather 'dry' and reduce students engagement with, and therefore retention of, material. Here we use participatory-based teaching approaches in microbiology as an example to illustrate to University undergraduate students the potentially devastating effects that a disease can have on a population. The 'threat' that diseases may pose and the manner in which they may spread and/or evolve can be challenging to communicate, especially in relation to the timescales associated with these factors in the case of an epidemic or pandemic.

The effect of Medicaid payer status on patient outcomes following repair of massive rotator cuff tears.

BACKGROUND: The influence of socioeconomic status and insurance type has not been studied extensively for RCR, particularly not in the high risk massive RCT population. The purpose of this study is to identify relationships between Medicaid payer status and patient outcomes following massive RCR. METHODS: A retrospective review of shoulder surgery database identified 29 patients undergoing massive rotator cuff repair. Patients were stratified based on insurance type into two cohorts, Medicaid (14 patients) and non-Medicaid (15 patients). Missed routine follow-up appointments and comorbidities were recorded and compared between groups. Group comparisons were made for pre- and postoperative patient-reported and functional outcomes. Outcome scores included American Shoulder and Elbow Shoulder Score (ASES), the Penn Shoulder Score, and the Subjective Shoulder Value (SSV). A p value of < 0.05 was considered significant for all statistical analyses. RESULTS: Medicaid patients were on average 7.1 years younger than non-Medicaid patients (49.8 vs. 56.9 years, respectively), and remaining demographics were comparable between groups. Preoperative patient-reported outcomes were only significantly different for ASES and ASES pain (p = 0.010, 0.037). There was excellent average improvement for Medicaid patients but no significant differences compared to non-Medicaid patients for ASES (p = 0.630), PENN scores (p = 0.395), and SSV (p = 0.198). Medicaid patients also had a higher number of missed and canceled appointments (28%) compared to non-Medicaid patients (18%). CONCLUSION: Medicaid coverage will expand to millions of uninsured Americans under current healthcare reform. Medicaid patients with massive RCT appear to significantly improve with surgical treatment.

Four distinct and unusual linker proteins in a mitotically dividing nucleus are derived from a 71-kilodalton polyprotein, lack p34cdc2 sites, and contain protein kinase A sites.

Tetrahymena thermophila micronuclei contain four linker-associated proteins, alpha, beta, gamma, and delta. Synthetic oligonucleotides based on N-terminal protein sequences of beta and gamma were used to clone the micronuclear linker histone (MLH) gene. The MLH gene is single copy and is transcribed into a 2.4-kb message encoding all four linker-associated proteins. The message is translated into a polypeptide (Mic LH) that is processed at the sequence decreases RTK to give proteins whose amino acid sequences differ markedly from each other, from the sequence of macronuclear H1, and from sequences of typical H1s of other organisms. This represents the first example of multiple chromatin proteins derived from a single polyprotein. The delta protein consists largely of two high-mobility-group (HMG) boxes. An evolutionary analysis of HMG boxes indicates that the delta HMG boxes are similar to the HMG boxes of tsHMG, a protein that appears in elongating mouse spermatids when they condense and cease transcription, suggesting that delta could play a similar role in the micronucleus. The micronucleus divides mitotically, while the macronucleus divides amitotically. Surprisingly, macronuclear H1 but not Mic LH contains sequences resembling p34cdc2 kinase phosphorylation sites, while each of the Mic LH-derived proteins contains a typical protein kinase A phosphorylation site in its carboxy terminus.

Variation in size frequency distribution of coral populations under different fishing pressures in two contrasting locations in the Indian Ocean.

This study aimed to assess how the size-frequency distributions of coral genera varied between reefs under different fishing pressures in two contrasting Indian Ocean locations (the Maldives and East Africa). Using generalized linear mixed models, we were able to demonstrate that complex interactions occurred between coral genera, coral size class and fishing pressure. In both locations, we found Acropora coral species to be more abundant in non-fished compared to fished sites (a pattern which was consistent for nearly all the assessed size classes). Coral genera classified as 'stress tolerant' showed a contrasting pattern i.e. were higher in abundance in fished compared to non-fished sites. Site specific variations were also observed. For example, Maldivian reefs exhibited a significantly higher abundance in all size classes of 'competitive' corals compared to East Africa. This possibly indicates that East African reefs have already been subjected to higher levels of stress and are therefore less suitable environments for 'competitive' corals. This study also highlights the potential structure and composition of reefs under future degradation scenarios, for example with a loss of Acropora corals and an increase in dominance of 'stress tolerant' and 'generalist' coral genera.

Methylation of CpGs as a determinant of transcriptional activation at alternative promoters for transforming growth factor-beta3.

The human transforming growth factor-beta3 (TGF-beta3) gene has a typical CpG island, the core of which is centered just upstream of its principle promoter. Activation of an alternative downstream promoter, leading to the production of a truncated mRNA lacking the portion of the 5' noncoding region responsible for translational inhibition of TGF-beta3 mRNA, is only evident in breast cancer cells. We compared the methylation status of genomic DNA isolated from a panel of breast (SKBR-3 and T47-D) and non-breast cancer (HT-1080, A673, and A375) cell lines by sequencing sodium metabisulfite-treated DNA. In all cell lines, the core of the TGF-beta3 CpG island was predominantly unmethylated, irrespective of promoter usage associated with that cell line. In contrast, we observed a marked difference in methylation at 19 CpG sites immediately flanking and downstream of the alternative promoter's transcription initiation site. Specifically, the non-breast cancer cell lines exhibited nearly complete methylation of these CpG sites, whereas in the breast cancer cell lines, these CpGs were predominantly unmethylated. Our data support the hypothesis that methylation of a limited number of CpGs at the periphery of an otherwise unmethylated CpG island underlies the transcriptional repression of the downstream promoter in non-breast cancer cells, thereby serving to regulate the use of alternative promoters for TGF-beta3.

Strain- and host species-specific inflammasome activation, IL-1ß release, and cell death in macrophages infected with uropathogenic Escherichia coli.

Uropathogenic Escherichia coli (UPEC) is the main etiological agent of urinary tract infections (UTIs). Little is known about interactions between UPEC and the inflammasome, a key innate immune pathway. Here we show that UPEC strains CFT073 and UTI89 trigger inflammasome activation and lytic cell death in human macrophages. Several other UPEC strains, including two multidrug-resistant ST131 isolates, did not kill macrophages. In mouse macrophages, UTI89 triggered cell death only at a high multiplicity of infection, and CFT073-mediated inflammasome responses were completely NLRP3-dependent. Surprisingly, CFT073- and UTI89-mediated responses only partially depended on NLRP3 in human macrophages. In these cells, NLRP3 was required for interleukin-1ß (IL-1ß) maturation, but contributed only marginally to cell death. Similarly, caspase-1 inhibition did not block cell death in human macrophages. In keeping with such differences, the pore-forming toxin α-hemolysin mediated a substantial proportion of CFT073-triggered IL-1ß secretion in mouse but not human macrophages. There was also a more substantial α-hemolysin-independent cell death response in human vs. mouse macrophages. Thus, in mouse macrophages, CFT073-triggered inflammasome responses are completely NLRP3-dependent, and largely α-hemolysin-dependent. In contrast, UPEC activates an NLRP3-independent cell death pathway and an α-hemolysin-independent IL-1ß secretion pathway in human macrophages. This has important implications for understanding UTI in humans.

An oligosaccharide component in proteoglycans of articular cartilage.

Two types of sialic acid-containing component are released from articular cartilage proteoglycan monomer (D1) treated with 0.05 M NaOH containing 1 M NaBH4. The smaller component, which has not been described before, contains galactosamine, glucosamine, galactose and sialic acid (Molar ratio 1:1:1:2). It is eluted from ECTEOLA-cellulose with low molarity (0.4 M) sodium formate and has Kav of 0.70 on Bio-gel P30. Its presence on the proteoglycan monomer was demonstrated at all stages of foetal and adult life.

Characterization of a proteoglycan of high electrophoretic mobility.

Proteoglycans from articular cartilage of young baboons (Papio papio) were fractionated on an associative density gradient. Material from the top of the gradient was shown to contain a proteoglycan of high electrophoretic mobility on large porosity gels. Associated and/or contaminating proteins were removed by ion-exchange chromatography on DEAE-cellulose and subsequent gel filtration on Sepharose 4B in the presence of 0.1% SDS. The electrophoretically homogeneous proteoglycan (Kd 0.43 on Sepharose 4B SDS) contained 39.7% protein, was rich in aspartate, glutamate, leucine and glycine and had a GalN : GluN molar ratio of 3.87.

Biochemical changes in intervertebral disc degeneration.

The distribution of the principal matrix components, collagen, proteoglycans and water, across the diameter of human normal and degenerate intervertebral discs was compared. Little difference in collagen distribution was noted between normal and degenerate tissue but water and proteoglycan content decreased with degeneration, particularly in the centre of the disc. Proteoglycans of the nucleus pulposus and annulus fibrosus of normal and degenerate intervertebral discs were examined. In comparison with monomers of normal tissues, degenerate disc proteoglycans were of larger average hydrodynamic size and had a higher glucosamine to galactosamine ratio. Proteoglycans were digested with chondroitinase ABC and passed over an HS-Sepharose 2B affinity column. A greater proportion of the keratan sulphate-protein cores from degenerate disc were capable of interaction with the immobilized hyaluronate. Loss of aggregating ability was associated with diminution in size of the core. It is suggested that a large proportion of proteoglycans from normal disc have undergone a degree of degradation in the hyaluronate binding region and that proteoglycan synthesis in this tissue is slower than in degenerate tissue.

Glycosaminoglycans and proteoglycans of human chondrosarcoma.

The glycosaminoglycans and proteoglycans of a human chondrosarcoma have been studied. Glycosaminoglycans were fractionated and identified by cetylpirdium chloride (CPC) cellulose chromatography, ECTEOLA cellulose ion-exchange chromatography and electrophoresis on cellulose acetate. Proteoglycans were extracted by low ionic strength solutions and by 4 M guanidinium chloride and fractioned by equilibrium density-gradient centrifugation and gel chromatography on Sepharose 2B. The tumour matrix contained both the 4- and 6-sulphate isomers of chondroitin sulphate and a high concentration (12% of hexosamine) of hyaluronic acid. Proteoglycans were poor in carbohydrate moieties and proportion were capable of aggregation. Amino acid analysis of the fractionated proteoglycans suggested the presence of a single protein core. A substance with the characteristic amino acid composition of glycoprotein link was recovered from the top of the dissociative density gradient.

Regional distribution of water and glycosaminoglycan in immature articular cartilage.

The distribution of water and glycosaminoglycan in different functional regions of bovine immature articular cartilage were studied. There was always more water in each articulating than in the corresponding growing zone, but there was less water in both zones in the areas of maximum contact. There was more hyaluronate and much more keratan sulphate in the articulating areas of maximum contact than in the minimum contact areas. In the growing zone the distribution of these two glycosaminoglycans did not vary as significantly but there was slightly more keratan sulphate in the area of maximum contact. Regional variations in chondroitin sulphate content were also present although not as striking as those of keratan sulphate. The results suggest that some keratan sulphate may be synthesized as a reaction to load.