Inflaming the diseased brain: a role for tainted melanins.

Inflammation plays a crucial role in neurodegenerative diseases, but the irritants responsible for this response remain largely unknown. This report addressed the hypothesis that hypochlorous acid reacts with dopamine to produce melanic precipitates that promote cerebral inflammation. Spectrophotometric studies demonstrated that nM amounts of HOCl and dopamine react within seconds. A second-order rate constant for the reaction of HOCl and dopamine of 2.5 × 10(4)M(-1)s(-1) was obtained by measuring loss of dopaminergic fluorescence due to HOCl. Gravimetric measurements, electron microscopy, elemental analysis, and a novel use of flow cytometry confirmed that the major product of this reaction is a precipitate with an average diameter of 1.5 µm. Flow cytometry was also used to demonstrate the preferential reaction of HOCl with dopamine rather than albumin. Engulfment of the chlorodopamine particulates by phagocytes in vitro caused these cells to release TNFα and die. Intrastriatal administration of 10(6) particles also increased the content of TNFα in the brain and led to a 50% loss of the dopaminergic neurons in the nigra. These studies indicate that HOCl and dopamine react quickly and preferentially with each other to produce particles that promote inflammation and neuronal death in the brain.

[Appropriate use of psychotropic drugs in institutionalized elderly presenting acute confusional state (delirium)]. / Usage adéquat des psychotropes chez les personnes âgées institutionnalisées en cas d'état confusionnel aigu (delirium).

Delirium (acute confusion) is a common, morbid, and costly geriatric syndrome that affects onethird of hospitalized older adults. As evidence mounts that delirium may persist for weeks to months, concern about delirium can no longer be restricted to acute hospitals. We present a review about non-pharmacologic and pharmacologic management of delirium in institution.

Le " Delirium " (état confusionnel) est un syndrome gériatrique fréquent et coûteux qui affecte un tiers des personnes âgées hospitalisées ; sa prévalence en institution est mal connue. Il apparaît que ce syndrome peut persister pendant des semaines à des mois, et n'est donc pas limité aux hospitalisations aiguës. Nous présentons une revue de la littérature sur la prise en charge du delirium en institution suivie d'une proposition d'algorithme définissant l'approche pharmacologique et non pharmacologique de ce syndrome gériatrique.

Benzophenone C- and O-glucosides from Cyclopia genistoides (Honeybush) inhibit mammalian α-glucosidase.

An enriched fraction of an aqueous extract prepared from the aerial parts of Cyclopia genistoides Vent. yielded a new benzophenone di-C,O-glucoside, 3-C-ß-d-glucopyranosyl-4-O-ß-d-glucopyranosyliriflophenone (1), together with small quantities of a known benzophenone C-glucoside, 3-C-ß-d-glucopyranosylmaclurin (2). The isolated compounds showed α-glucosidase inhibitory activity against an enzyme mixture extracted from rat intestinal acetone powder. Compound 2 exhibited significantly (p < 0.05) higher inhibitory activity (54%) than 1 (43%) at 200 µM. In vitro tests in several cell models showed that 1 and its 3-C-monoglucosylated derivative (3-C-ß-d-glucopyranosyliriflophenone) were marginally effective (p ≥ 0.05) in increasing glucose uptake.

Characterisation of freeze-dried type II collagen and chondroitin sulfate scaffolds.

Collagen type-II is the dominant type of collagen in articular cartilage and chondroitin sulfate is one of the main components of cartilage extracellular matrix. Afibrillar and fibrillar type-II atelocollagen scaffolds with and without chondroitin sulfate were prepared using casting and freeze-drying methods. The scaffolds were characterised to highlight the effects of fibrillogenesis and chondroitin sulfate addition on viscosity, pore structure, porosity and mechanical properties. Microstructure analysis showed that fibrillogenesis increased the circularity of pores significantly in collagen-only scaffolds, whereas with it, no significant change was observed in chondroitin sulfate-containing scaffolds. Addition of chondroitin sulfate to afibrillar scaffolds increased the circularity of the pores and the proportion of pores between 50 and 300 µm suitable for chondrocytes growth. Fourier transform infrared spectroscopy explained the bonding between chondroitin sulfate and afibrillar collagen- confirmed with rheology results- which increased the compressive modulus 10-fold to 0.28 kPa. No bonding was observed in other scaffolds and consequently no significant changes in compressive modulus were detected.

A shift in the collagen V antigenic epitope leads to T helper phenotype switch and immune response to self-antigen leading to chronic lung allograft rejection.

Immune responses to human leucocyte antigen (HLA) and self-antigen collagen V (Col-V) have been proposed in the pathogenesis of chronic rejection (bronchiolitis obliterans syndrome, BOS) following human lung transplantation (LTx). In this study, we defined the role for the shift in immunodominant epitopes of Col-V in inducing T helper phenotype switch leading to immunity to Col-V and BOS. Sera and lavage from BOS(+) LTx recipients with antibodies to Col-V were analysed. Two years prior to BOS, patients developed antibodies to both Col-V,α1(V) and α2(V) chains. However, at clinical diagnosis of BOS, antibodies became restricted to α1(V). Further, lung biopsy from BOS(+) patients bound to antibodies to α1(V), indicating that these epitopes are exposed. Fourteen Col-V peptides [pep1-14, pep1-4 specific to α1(V), pep5-8 to α1,2(V) and pep9-14 to α2(V)] which bind to HLA-DR4 and -DR7, demonstrated that prior to BOS, pep 6, 7, 9, 11 and 14 were immunodominant and induced interleukin (IL)-10. However, at BOS, the response switched to pep1, 4 and 5 and induced interferon (IFN)-γ and IL-17 responses, but not IL-10. The T helper (Th) phenotype switch is accompanied by decreased frequency of regulatory T cells (T(regs) ) in the lavage. LTx recipients with antibodies to α1(V) also demonstrated increased matrix metalloproteinase (MMP) activation with decreased MMP inhibitor, tissue inhibitor of metalloproteinase (TIMP), suggesting that MMP activation may play a role in the exposure of new Col-V antigenic epitopes. We conclude that a shift in immunodominance of self-antigenic determinants of Col-V results in induction of IFN-γ and IL-17 with loss of tolerance leading to autoimmunity to Col-V, which leads to chronic lung allograft rejection.

How Low Can You Go? The Radiobiology of Hypofractionation.

Hypofractionated radical radiotherapy is now an accepted standard of care for tumour sites such as prostate and breast cancer. Much research effort is being directed towards more profoundly hypofractionated (ultrahypofractionated) schedules, with some reaching UK standard of care (e.g. adjuvant breast). Hypofractionation exerts varying influences on each of the major clinical end points of radiotherapy studies: acute toxicity, late toxicity and local control. This review will discuss these effects from the viewpoint of the traditional 5 Rs of radiobiology, before considering non-canonical radiobiological effects that may be relevant to ultrahypofractionated radiotherapy. The principles outlined here may assist the reader in their interpretation of the wealth of clinical data presented in the tumour site-specific articles in this special issue.

Development of Tri-Layered Biomimetic Atelocollagen Scaffolds with Interfaces for Osteochondral Tissue Engineering.

The development of biomimetic scaffolds containing cartilage, calcified cartilage, and bone regeneration for precise osteochondral repair remains a challenge. Herein, a novel tri-layered scaffold-with a top layer containing type II atelocollagen and chondroitin sulphate for cartilage regeneration, an intermediate layer with type II atelocollagen and hydroxyapatite for calcified cartilage formation, and a bottom layer with type I atelocollagen and hydroxyapatite for bone growth-that can be built using liquid-phase cosynthesis, is described. The tri-layered scaffolds are mechanically demonstrably superior and have a lower risk of delamination than monolayer scaffolds. This is due to higher cohesion arising from the interfaces between each layer. In vitro results show that although monolayer scaffolds can stimulate bone marrow stem cells to differentiate and form cartilage, calcified cartilage, and bone separately (detected using quantitative polymerase chain reaction analysis and staining with safranin-O and Alizarin Red S), the tri-layered scaffolds support the regeneration of cartilage, calcified cartilage, and bone simultaneously after 2 and 4 months of implantation (detected using gross and micro-computed tomography images, histological staining, and Avizo, a software used to detect microlevel defects in metals). This work presents data on a promising approach in devising strategies for the precise repair of osteochondral defects.

Validated intraclass correlation statistics to test item performance models.

A new method, with an application program in Matlab code, is proposed for testing item performance models on empirical databases. This method uses data intraclass correlation statistics as expected correlations to which one compares simple functions of correlations between model predictions and observed item performance. The method rests on a data population model whose validity for the considered data is suitably tested and has been verified for three behavioural measure databases. Contrarily to usual model selection criteria, this method provides an effective way of testing under-fitting and over-fitting, answering the usually neglected question "does this model suitably account for these data?"

What Can Proton Beam Therapy Achieve for Patients with Pectus Excavatum Requiring Left Breast, Axilla and Internal Mammary Nodal Radiotherapy?

AIMS: Exposure of the heart to radiation increases the risk of ischaemic heart disease, proportionate to the mean heart dose (MHD). Radiotherapy techniques including proton beam therapy (PBT) can reduce MHD. The aims of this study were to quantify the MHD reduction achievable by PBT compared with volumetric modulated arc therapy in breath hold (VMAT-BH) in patients with pectus excavatum (PEx), to identify an anatomical metric from a computed tomography scan that might indicate which patients will achieve the greatest MHD reductions from PBT. MATERIALS AND METHODS: Sixteen patients with PEx (Haller Index ≥2.7) were identified from radiotherapy planning computed tomography images. Left breast/chest wall, axilla (I-IV) and internal mammary node (IMN) volumes were delineated. VMAT and PBT plans were prepared, all satisfying target coverage constraints. Signed-rank comparisons of techniques were undertaken for the mean dose to the heart, ipsilateral lung and contralateral breast. Spearman's rho correlations were calculated for anatomical metrics against MHD reduction achieved by PBT. RESULTS: The mean MHD for VMAT-BH plans was 4.1 Gy compared with 0.7 Gy for PBT plans. PBT reduced MHD by an average of 3.4 Gy (range 2.8-4.4 Gy) compared with VMAT-BH (P < 0.001). PBT significantly reduced the mean dose to the ipsilateral lung (4.7 Gy, P < 0.001) and contralateral breast (2.7 Gy, P < 0.001). The distance (mm) at the most inferomedial extent of IMN volume (IMN to heart distance) negatively correlated with MHD reduction achieved by PBT (Spearman's rho -0.88 (95% confidence interval -0.96 to -0.67, P < 0.001)). CONCLUSION: For patients with PEx requiring left-sided breast and IMN radiotherapy, a clinically significant MHD reduction is achievable using PBT, compared with the optimal photon technique (VMAT-BH). This is a patient group in whom PBT could have the greatest benefit.

An HLA-DR1 transgene confers susceptibility to collagen-induced arthritis elicited with human type II collagen.

Rheumatoid arthritis (RA) is an autoimmune disease that is strongly associated with the expression of several HLA-DR haplotypes, including DR1 (DRB1*0101). Although the antigen that initiates RA remains elusive, it has been shown that many patients have autoimmunity directed to type II collagen (CII). To test the hypothesis that HLA-DR1 is capable of mediating an immune response to CII, we have generated transgenic mice expressing chimeric (human/mouse) HLA-DR1. When the DR1 transgenic mice were immunized with human CII (hCII), they developed a severe autoimmune arthritis, evidenced by severe swelling and erythema of the limbs and marked inflammation and erosion of articular joints. The development of the autoimmune arthritis was accompanied by strong DR1-restricted T and B cell responses to hCII. The T cell response was focused on a dominant determinant contained within CII(259-273) from which an eight amino acid core was defined. The B cell response was characterized by high titers of antibody specific for hCII, and a high degree of cross-reactivity with murine type II collagen. These data demonstrate that HLA-DR1 is capable of presenting peptides derived from hCII, and suggest that this DR1 transgenic model will be useful in the development of DR1-specific therapies for RA.

Detailed Phenolic Characterization of Protea Pure and Hybrid Cultivars by Liquid Chromatography-Ion Mobility-High Resolution Mass Spectrometry (LC-IM-HR-MS).

In this study we report a detailed investigation of the polyphenol composition of Protea pure (P. cynaroides and P. neriifolia) and hybrid cultivars (Black beauty and Limelight). Aqueous methanol extracts of leaf and bract tissues were analyzed by ultrahigh pressure liquid chromatography hyphenated to photodiode array and ion mobility-high resolution mass spectrometric (UHPLC-PDA-IM-HR-MS) detection. A total of 67 metabolites were characterized based on their relative reversed phase (RP) retention, UV-vis spectra, low and high collision energy HR-MS data, and collisional cross section (CCS) values. These metabolites included 41 phenolic acid esters and 25 flavonoid derivatives, including 5 anthocyanins. In addition, an undescribed hydroxycinnamic acid-polygalatol ester, caffeoyl-O-polygalatol (1,5-anhydro-[6-O-caffeoyl]-sorbitol(glucitol)) was isolated and characterized by 1D and 2D NMR for the first time. This compound and its isomer are shown to be potential chemo-taxonomic markers.

Roots and Nodules Response Differently to P Starvation in the Mediterranean-Type Legume Virgilia divaricata.

Virgilia divaricata is a tree legume that grows in the Cape Floristic Region (CFA) in poor nutrient soils. A comparison between high and low phosphate growth conditions between roots and nodules was conducted and evaluated for the plants ability to cope under low phosphate stress conditions in V. divaricata. We proved that the plant copes with low phosphate stress through an increased allocation of resources, reliance on BNF and enhanced enzyme activity, especially PEPC. Nodules had a lower percentage decline in P compared to roots to uphold its metabolic functions. These strategies partly explain how V. divaricata can sustain growth despite LP conditions. Although the number of nodules declined with LP, their biomass remained unchanged in spite of a plant decline in dry weight. This is achieved via the high efficiency of BNF under P stress. During LP, nodules had a lower % decline at 34% compared to the roots at 88%. We attribute this behavior to P conservation strategies in LP nodules that imply an increase in a metabolic bypass that operates at the PEP branch point in glycolysis. The enhanced activities of nodule PEPC, MDH, and ME, whilst PK declines, suggests that under LP conditions an adenylate bypass was in operation either to synthesize more organic acids or to mediate pyruvate via a non-adenylate requiring metabolic route. Both possibilities represent a P-stress adaptation route and this is the first report of its kind for legume trees that are indigenous to low P, acid soils. Although BNF declined by a small percentage during LP, this P conservation was evident in the unchanged BNF efficiency per weight, and the increase in BNF efficiency per mol of P. It appears that legumes that are indigenous to acid soils, may be able to continue their reliance on BNF via increased allocation to nodules and also due to increase their efficiency for BNF on a P basis, owing to P-saving mechanisms such as the organic acid routes.

Silencing S1P1 receptors regulates collagen-V reactive lymphocyte-mediated immunobiology in the transplanted lung.

Type V collagen (col[V])-reactive lymphocytes contribute to lung transplant rejection, but the mechanisms for emigration into the graft are unknown. Sphingosine-1-phosphate-1 receptors (S1P(1R)) are believed to be required for lymphocyte emigration in other studies, but their role in col(V)-reactive lymphocyte rejection responses is not known. Utilizing small interfering RNA (siRNA) to reduce S1P(1R) expression on col(V)-reactive lymphocytes, we examined the role of S1P(1R) in the rejection response. Quantitative polymerase chain reaction (PCR) revealed strong expression of S1P(1R) messenger RNA (mRNA)on col(V)-reactive lymphocytes isolated from immunized rats. S1P(1R)-specific siRNA (S1P(1R) siRNA) reduced expression of S1P(1R) mRNA and protein, whereas scramble siRNA (SC siRNA) had no effect. Adoptive transfer of lymphocytes treated with S1P(1R) siRNA to rat Wistar Kyoto (WKY) lung isograft recipients resulted in retention of cells within the liver with fewer cells in mediastinal lymph nodes when compared to cells exposed to SC siRNA. S1P(1R)-deficient cells proliferated in response to alloantigens, but not in response to col(V), and produced less interferon (IFN)-gamma in response to col(V) compared to controls. Downregulating S1P(1R) did not affect production of interleukin (IL)-10and tumor necrosis factor (TNF)-alpha, or expression of adhesion molecules critical for migration, but prevented rejection pathology and lowered local levels of IFN-gamma post adoptive transfer. These data demonstrate novel roles of S1P(1R,) which include regulating emigration and modulating lymphocyte activation.

RNA amplification of the HIV-1 Pol and env regions on dried serum and plasma spots.

BACKGROUND: Dried sample spots have molecular applications, but few data are available on conditions of HIV-1 RNA amplification. OBJECTIVES: To determine the impact of (i) the sample type (plasma or serum), (ii) various storage periods, (iii) transfer at ambient temperature of the dried spots via postal mail, and (iv) two different methods of elution-extraction, to amplify partial pol and env genes with a view to both phylogenic and resistance analyses. METHODS: Fourteen samples (dried plasma spot and dried serum spot) from seven patients were stored at 20-25 degrees C for 2, 5 and 7 days. Two extraction buffers were tested on these samples, followed by reverse transcriptase-polymerase chain reaction (RT-PCR) on pol and env genes. Sixteen spots from eight other patients were sent by postal mail at ambient temperature between two laboratories, and were analysed at both sites. RESULTS: We observed no influence of the 2-7 day storage period, whatever the sample type and viral load, but the choice of the extraction procedure is a critical step. Analysis of the mailed spots resulted in a good agreement between the two laboratories. CONCLUSIONS: This study shows that amplification of HIV-1 RNA on spots is possible in various conditions by different operators and using appropriate reagents. This finding could be particularly useful for large-scale molecular and resistance epidemiological studies in resource-rich and resource-limited countries alike.

Iron diapirs entrain silicates to the core and initiate thermochemical plumes.

Segregation of the iron core from rocky silicates is a massive evolutionary event in planetary accretion, yet the process of metal segregation remains obscure, due to obstacles in simulating the extreme physical properties of liquid iron and silicates at finite length scales. We present new experimental results studying gravitational instability of an emulsified liquid gallium layer, initially at rest at the interface between two glucose solutions. Metal settling coats liquid metal drops with a film of low density material. The emulsified metal pond descends as a coherent Rayleigh-Taylor instability with a trailing fluid-filled conduit. Scaling to planetary interiors and high pressure mineral experiments indicates that molten silicates and volatiles are entrained toward the iron core and initiate buoyant thermochemical plumes that later oxidize and hydrate the upper mantle. Surface volcanism from thermochemical plumes releases oxygen and volatiles linking atmospheric growth to the Earth's mantle and core processes.

Distractor effects during processing of words under load.

The perceptual load model of attention (Lavie, 1995) suggests that processing of irrelevant distractors depends on the extent to which a relevant task engages full perceptual capacity. Word recognition models suggest that letter perception is facilitated in words relative to nonwords. These models led us to hypothesize that increasing the number of letters would increase perceptual load more for nonwords than for words, and thus would be more likely to exhaust capacity and eliminate distractor processing for nonwords than for words. In support of this hypothesis, we found that increasing the number of search letters increases RTs more for nonwords than for words and only reduces distractor interference for nonwords. Thus, although readers process words more efficiently than nonwords, they also become more prone to distraction when processing words.

Ophthalmologic findings in infants after an apparent life-threatening event.

PURPOSE: An apparent life-threatening event (ALTE) refers to the sudden occurrence in an infant of a breathing abnormality, color change, or alteration in muscle tone or mental status. The finding of retinal hemorrhage in an infant who has experienced an ALTE strongly suggests the possibility of shaken baby syndrome. Previous ALTE studies have reported the frequency of this specific ocular abnormality but have not reported other ocular findings and their possible diagnostic significance. METHODS: This study reviews ophthalmologic findings from a series of 120 patients with ALTE who underwent eye examinations as part of their inpatient evaluation. Details of the history, physical examination, diagnostic testing, and discharge diagnosis were abstracted from the medical record while the patient was in the hospital. RESULTS: Ten patients (8.3%) had positive findings, including retinal hemorrhages in four of the six patients with shaken baby syndrome, the only ophthalmologic finding that helped establish the cause of an ALTE. CONCLUSIONS: Since the funduscopic examination can help identify child abuse as the cause of an apparent life-threatening event, ophthalmologists play a critical role in the early evaluation of infants who have experienced such an event.

Monomeric, porous type II collagen scaffolds promote chondrogenic differentiation of human bone marrow mesenchymal stem cells in vitro.

Osteoarthritis (OA) is a common cause of pain and disability and is often associated with the degeneration of articular cartilage. Lesions to the articular surface, which are thought to progress to OA, have the potential to be repaired using tissue engineering strategies; however, it remains challenging to instruct cell differentiation within a scaffold to produce tissue with appropriate structural, chemical and mechanical properties. We aimed to address this by driving progenitor cells to adopt a chondrogenic phenotype through the tailoring of scaffold composition and physical properties. Monomeric type-I and type-II collagen scaffolds, which avoid potential immunogenicity associated with fibrillar collagens, were fabricated with and without chondroitin sulfate (CS) and their ability to stimulate the chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells was assessed. Immunohistochemical analyses showed that cells produced abundant collagen type-II on type-II scaffolds and collagen type-I on type-I scaffolds. Gene expression analyses indicated that the addition of CS - which was released from scaffolds quickly - significantly upregulated expression of type II collagen, compared to type-I and pure type-II scaffolds. We conclude that collagen type-II and CS can be used to promote a more chondrogenic phenotype in the absence of growth factors, potentially providing an eventual therapy to prevent OA.

Cardiologists' practices compared with practice guidelines: use of beta-blockade after acute myocardial infarction.

OBJECTIVE: Our purpose was to measure cardiologists' level of adherence to guidelines for long-term use of beta-adrenergic blocker therapy after acute myocardial infarction. BACKGROUND: Beta-blocker therapy after acute myocardial infarction has been shown to reduce the incidence of reinfarction and associated mortality. To learn about cardiologists' use of this therapy after hospital discharge and their level of adherence to American College of Cardiology guidelines, we analyzed insurance claims from 17 network-model health plans located throughout the United States. METHODS: The study group included 150 cardiologists who had contracts with one of the health plans and their 280 patients who were plan members (excluding Medicare enrollees) and received inpatient treatment for acute myocardial infarction that did not include revascularization during 1992. These patients accounted for 307 separate hospital admissions. Insurance claims were used to measure beta-blocker usage and to identify possible contraindications. RESULTS: Forty-three percent of the cases (131 of 307) involved apparent deviations from the guidelines: 11% of cases (35 of 307) involved possible errors of commission (beta-blocker given in the presence of a contraindication) and 31% (96 of 307) errors of omission (beta-blocker not given in the absence of a contraindication). Of the 185 patients who were eligible for the therapy (no contraindications), only 48% (89 of 185) were treated. CONCLUSIONS: Cardiologists currently exhibit a low level of compliance with their specialty's guidelines for postinfarction beta-blockade. Slightly fewer than 50% of the study patients who were eligible for treatment actually received a beta-blocker after hospital discharge. This result, combined with the drug's known level of effectiveness in preventing recurrent myocardial infarction, suggests that increased use could avert approximately 1,900 deaths annually nationwide.