Nearly Antiferromagnetic Fermi Liquids: A Progress Report

I describe recent theoretical and experimental progress in understanding the physical properties of the two dimensional nearly antiferromagnetic Fermi liquids (NAFL's) found in the normal state of the cuprate superconductors. In such NAFL's, the magnetic interaction between planar quasiparticles is strong and peaked at or near the commensurate wave vector, $Q \equiv (\pi,\pi)$. For the optimally doped and underdoped systems, the resulting strong antiferromagnetic correlations produce three distinct magnetic phases in the normal state: mean field above $T_{cr}$, pseudoscaling between $T_{cr}$ and $T_*$, and pseudogap below $T_*$. I present arguments which suggest that the physical origin of the pseudogap found in the quasiparticle spectrum below $T_{cr}$ is the formation of a precursor to a spin-density-wave-state, describe the calculations based on this scenario of the dynamical spin susceptibility, Fermi surface evolution, transport, and Hall effect, and summarize the experimental evidence in its support.Comment: LATEX + PS figures. To appear in the proceedings of the Euroconference on "Correlations in Unconventional Quantum Liquids," Evora, Portugal, October 199

Inhibition of Burkholderia Multivorans Adhesion to Lung Epithelial Cells by Bivalent Lactosides

Burkholderia cepacia complex (Bcc) is an opportunistic pathogen in cystic fibrosis patients which is inherently resistant to antimicrobial agents. The mechanisms of attachment and pathogenesis of Bcc, a group of 17 species, are poorly understood. The most commonly identified Bcc species in newly colonised patients, Burkholderia multivorans, continues to be acquired from the environment. Development of therapies which can prevent or reduce the risk of colonization on exposure to Bcc in the environment would be a better alternative to antimicrobial agents. Previously, it has been shown that Bcc strains bound to many glycolipid receptors on lung epithelia. Using a real-time PCR method to quantify the levels of binding of B. multivorans to the lung epithelial cells, we have examined glycoconjugate derivatives for their potential to inhibit host cell attachment. Bivalent lactosides previously shown to inhibit galectin binding significantly reduced the attachment of B. multivorans to CF lung epithelial cells at micromolar concentrations. This was in contrast to monosaccharides and lactose, which were only effective in the millimolar range. Development of glycoconjugate therapies such as these, which inhibit attachment to lung epithelial cells, represent an alternative means of preventing infection with inherently antimicrobially resistant pathogens such as B. multivorans

Inhibition of Burkholderia multivorans Adhesion to Lung Epithelial Cells by Bivalent Lactosides

Burkholderia cepacia complex (Bcc) is an opportunistic pathogen in cystic fibrosis patients which is inherently resistant to antimicrobial agents. The mechanisms of attachment and pathogenesis of Bcc, a group of 17 species, are poorly understood. The most commonly identified Bcc species in newly colonised patients, Burkholderia multivorans, continues to be acquired from the environment. Development of therapies which can prevent or reduce the risk of colonization on exposure to Bcc in the environment would be a better alternative to antimicrobial agents. Previously, it has been shown that Bcc strains bound to many glycolipid receptors on lung epithelia. Using a real-time PCR method to quantify the levels of binding of B. multivorans to the lung epithelial cells, we have examined glycoconjugate derivatives for their potential to inhibit host cell attachment. Bivalent lactosides previously shown to inhibit galectin binding significantly reduced the attachment of B. multivorans to CF lung epithelial cells at micromolar concentrations. This was in contrast to monosaccharides and lactose, which were only effective in the millimolar range. Development of glycoconjugate therapies such as these, which inhibit attachment to lung epithelial cells, represent an alternative means of preventing infection with inherently antimicrobially resistant pathogens such as B. multivorans

Synthesis of Bivalent Lactosides Based on Terephthalamide, N,N0-Diglucosylterephthalamide, and Glycophane Scaffolds and Assessment of Their Inhibitory Capacity on Medically Relevant Lectins

Glycan recognition by lectins initiates clinically relevant processes such as toxin binding or tumor spread. Thus, the development of potent inhibitors has a medical perspective. Toward this goal, we report the synthesis of both rigid and flexible bivalent lactosides on scaffolds that include secondary and tertiary terephthalamides and N,N0-diglucosylterephthalamides. Construction of these compounds involved Schmidt-Michel glycosidation, and amide coupling or Ugi reactions of relevant glycosyl amines in key steps. A glycocluster based on a rigid glycophane was also prepared from coupling of a glucuronic acid derivative and p-xylylenediamine with subsequent ring-closing metathesis. Finally, a more flexible bivalent lactoside was produced from lactosyl azide with use of the copper-catalyzed azide-alkyne cycloaddition. Distances between lactose residues were analyzed computationally as were their orientations for the relatively rigid subset of compounds. Distinct spacing properties were revealed by varying the structure of the scaffold or by varying the location of the lactose residue on the scaffold. To relate these features to bioactivity a plant toxin and human adhesion/growth-regulatory galectins were used as sensors in three types of assay, i.e. measuring agglutination of erythrocytes, binding to glycans of a surface-immobilized glycoprotein, or binding to human cells.Methodologically, the common hemeagglutination assaywas found to be considerably less sensitive than both solid-phase and cell assays. The bivalent compounds were less effective at interfering with glycoprotein binding to the plant toxin than to human lectins. Significantly, a constrained compound was identified that displayed selectivity in its inhibitory potency between galectin-3 and its proteolytically processed form. Conversely, compounds with a high degree of flexibility showed notable ability to protect human cells fromplant toxin binding. The applied conjugation chemistry thus is compatiblewith the long-termaim to produce potent and selective lectin inhibitors

Phenylenediamine-based bivalent glycocyclophanes: synthesis and analysis of the influence of scaffold rigidity and ligand spacing on lectin binding in cell systems with different glycomic profiles

The conjugation of carbohydrates to synthetic scaffolds has the goal of preparing potent inhibitors of lectin binding. We herein report the synthesis of a panel of bivalent compounds (cyclophane and terephthalamide-derivatives) then used to establish the influence of scaffold flexibility on respective inhibitory potency in a medically relevant test system. Synthetic routes to two phenylenediamine-based glycocyclophanes involving Ugi reactions of glucuronic acid derivatives and subsequent ring closing metathesis are described, as are improvements for producing terephthalamide-based carbohydrate carriers. Assays were performed with human tumour cells measuring quantitatively the influence of the test compounds on fluorescent surface staining by labelled lectins. Biological evaluation using two different lines of cancer cells as well as cells with known alterations in the glycomic profile (cells treated with an inhibitor of glycan processing and a glycosylation mutant) reduced the risk of generating premature generalizations regarding inhibitor potency. Bioactivity relative to free mannose was invariably determined for the synthetic compounds. A clear trend for enhanced inhibitory properties for macrocyclic compounds compared to non-macrocyclic derivatives was discerned for one type of glycocyclophane. Herein we also document the impact of altering the spacing between the mannose residues, altering cell surface ligand density and cell-type reactivity. The applied strategy for the cell assays is proposed to be of general importance in the quest to identify medically relevant lectin inhibitors

Incidence of first stroke and ethnic differences in stroke pattern in Bradford, UK: Bradford Stroke Study

Background: Information on ethnic disparities in stroke between White and Pakistani population in Europe is scarce. Bradford District has the largest proportion of Pakistani people in England; this provides a unique opportunity to study the difference in stroke between the two major ethnic groups. Aim: To determine the first-ever-stroke incidence and examine the disparities in stroke patterns between Whites and Pakistanis in Bradford. Methods: Prospective 12 months study consisting of 273,327 adults (≥18 years) residents. Stroke cases were identified by multiple overlapping approaches. Results: In the study period, 541 first-ever-strokes were recorded. The crude incidence rate was 198 per 100,000 person-years. Age adjusted-standardized rate to the World Health Organization world population of first-ever-stroke is 155 and 101 per 100,000 person-years in Pakistanis and Whites respectively. Four hundred and thirty-eight patients (81%) were Whites, 83 (15.3%) were Pakistanis, 11 (2%) were Indian and Bangladeshis, and 9 (1.7%) were of other ethnic origin. Pakistanis were significantly younger and had more obesity (p = 0.049), and diabetes mellitus (DM) (p = <0.001). They were less likely to suffer from atrial fibrillation (p = <0.001), be ex- or current smokers (p = <0.001), and drink alcohol above the recommended level (p = 0.007) compared with Whites. In comparison with Whites, higher rates of age-adjusted stroke (1.5-fold), lacunar infarction (threefold), and ischemic infarction due to large artery disease (twofold) were found in the Pakistanis. Conclusions: The incidence of first-ever-stroke is higher in the Pakistanis compared with the Whites in Bradford, UK. Etiology and vascular risk factors vary between the ethnic groups. This information should be considered when investigating stroke etiology, and when planning prevention and care provision to improve outcomes after stroke

Skin flora: Differences Between People Affected by Albinism and Those with Normally Pigmented Skin in Northern Tanzania - Cross Sectional Study.

Skin flora varies from one site of the body to another. Individual's health, age and gender determine the type and the density of skin flora. A 1  cm² of the skin on the sternum was rubbed with sterile cotton swab socked in 0.9% normal saline and plated on blood agar. This was cultured at 35 °C. The bacteria were identified by culturing on MacConkey agar, coagulase test, catalase test and gram staining. Swabs were obtained from 66 individuals affected by albinism and 31 individuals with normal skin pigmentation. Those with normal skin were either relatives or staying with the individuals affected by albinism who were recruited for the study. The mean age of the 97 recruited individuals was 30.6 (SD ± 14.9) years. The mean of the colony forming units was 1580.5 per cm2. Those affected by albinism had a significantly higher mean colony forming units (1680  CFU per cm²) as compared with 453.5  CFU per cm² in those with normally pigmented skin (p = 0.023). The skin type and the severity of sun- damaged skin was significantly associated with a higher number of colony forming units (p = 0.038). Individuals affected by albinism have a higher number of colony forming units which is associated with sun- damaged skin

Interaction and efficacy of Keigai-rengyo-to extract and acupuncture in male patients with acne vulgaris: A study protocol for a randomized controlled pilot trial

<p>Abstract</p> <p>Background</p> <p>In consideration of patients seeking to use traditional Chinese medicine, an evidence-based potentiality for safe and effective use of herbal medicine and acupuncture in treatment of acne vulgaris has been suggested. However, despite common use of a combination of herbal medicine and acupuncture in clinical practice, the current level of evidence is insufficient to draw a conclusion for an interaction and efficacy of herbal medicine and acupuncture. Therefore, considering these methodological flaws, this study was designed to assess the interaction and efficacy of an available herbal medicine, Keigai-rengyo-to extract (KRTE), and acupuncture for treatment of acne using the 2 × 2 factorial design and the feasibility of a large clinical trial.</p> <p>Methods/Design</p> <p>A randomized, assessor single blinded, 2 × 2 factorial pilot trial will be conducted. Forty four participants with acne vulgaris will be randomized into one of four groups: waiting list group (WL), KRTE only group (KO), acupuncture only group (AO), and KRTE and acupuncture combined treatment group (KA). After randomization, a total of 8 sessions of acupuncture treatment will be performed twice a week in the AO- and KA groups, respectively. Patients in the KO- and KA groups will be prescribed KRTE 3 times a day at a dose of 7.4 g after meals for 4 weeks. The following outcome measurements will be used in examination of subjects: the mean percentage change and the count change of inflammatory and non-inflammatory acne lesions, the Skindex 29, visual analogue scale (VAS) and investigator global assessment (IGA) from baseline to the end of the trial.</p> <p>Trial Registration</p> <p>The trial is registered with the Clinical Research Information Service (CRiS), Republic of Korea: KCT0000071.</p

Does Social Capital Promote Physical Activity? A Population-Based Study in Japan

To examine the association between individual-level social capital and physical activity.In February 2009, data were collected in a population-based cross-sectional survey in Okayama city, Japan. A cluster-sampling approach was used to randomly select 4,000 residents from 20 school districts. A total of 2260 questionnaires were returned (response rate: 57.4%). Individual-level social capital was assessed by an item inquiring about perceived trust of others in the community (cognitive dimension of social capital) categorized as low trust (43.0%), mid trust (38.6%), and high trust (17.3%), as well as participation in voluntary groups (structural dimension of social capital), which further distinguished between bonding (8.9%) and bridging (27.1%) social capital. Using logistic regression, we calculated the odds ratios (ORs) and 95% confidence intervals (CIs) for physical inactivity associated with each domain of social capital. Multiple imputation method was employed for missing data. Among total participants, 68.8% were physically active and 28.9% were inactive. Higher trust was associated with a significantly lower odds of physical inactivity (OR = 0.58, 95% CI = 0.42-0.79) compared with low trust. Both bridging and bonding social capital were marginally significantly associated with lower odds of physical inactivity (bridging, OR = 0.79, 95% CI = 0.62-1.00; bonding, OR = 0.71, 95% CI = 0.48-1.03) compared with lack of structural social capital.Low individual-level social capital, especially lower trust of others in the community, was associated with physical inactivity among Japanese adults

Characterization of the Fungal Microbiota (Mycobiome) in Healthy and Dandruff-Afflicted Human Scalps

The human scalp harbors a vast community of microbial mutualists, the composition of which is difficult to elucidate as many of the microorganisms are not culturable using current culture techniques. Dandruff, a common scalp disorder, is known as a causative factor of a mild seborrheic dermatitis as well as pityriasis versicolor, seborrheic dermatitis, and atopic dermatitis. Lipophilic yeast Malassezia is widely accepted to play a role in dandruff, but relatively few comprehensive studies have been reported. In order to investigate fungal biota and genetic resources of dandruff, we amplified the 26S rRNA gene from samples of healthy scalps and dandruff-afflicted scalps. The sequences were analyzed by a high throughput method using a GS-FLX 454 pyrosequencer. Of the 74,811 total sequence reads, Basidiomycota (Filobasidium spp.) was the most common phylum associated with dandruff. In contrast, Ascomycota (Acremonium spp.) was common in the healthy scalps. Our results elucidate the distribution of fungal communities associated with dandruff and provide new avenues for the potential prevention and treatment of dandruff