Mass Spectrometry-Based Strategies for Assessing Human Exposure Using Hemoglobin Adductomics

Hemoglobin (Hb) adducts are widely used in human biomonitoring due to the high abundance of hemoglobin in human blood, its reactivity toward electrophiles, and adducted protein stability for up to 120 days. In the present paper, we compared three methods of analysis of hemoglobin adducts: mass spectrometry of derivatized N-terminal Val adducts, mass spectrometry of N-terminal adducted hemoglobin peptides, and limited proteolysis mass spectrometry . Blood from human donors was incubated with a selection of contact allergens and other electrophiles, after which hemoglobin was isolated and subjected to three analysis methods. We found that the FIRE method was able to detect and reliably quantify N-terminal adducts of acrylamide, acrylic acid, glycidic acid, and 2,3-epoxypropyl phenyl ether (PGE), but it was less efficient for 2-methyleneglutaronitrile (2-MGN) and failed to detect 1-chloro-2,4-dinitrobenzene (DNCB). By contrast, bottom-up proteomics was able to determine the presence of adducts from all six electrophiles at both the N-terminus and reactive hemoglobin side chains. Limited proteolysis mass spectrometry, studied for four contact allergens (three electrophiles and a metal salt), was able to determine the presence of covalent hemoglobin adducts with one of the three electrophiles (DNCB) and coordination complexation with the nickel salt. Together, these approaches represent complementary tools in the study of the hemoglobin adductome.

Investigation into Propolis Components Responsible for Inducing Skin Allergy: Air Oxidation of Caffeic Acid and Its Esters Contribute to Hapten Formation

Propolis is a resin-like material produced by bees from the buds of poplar and cone-bearing trees and is used in beehive construction. Propolis is a common additive in various biocosmetics and health-related products, despite the fact that it is a well-known cause of contact allergy. Caffeic acid and its esters have been the primary suspects behind the sensitization potency of propolis-induced contact allergy. However, the chemical structures of the protein adducts formed between these haptens and skin proteins during the process of skin sensitization remain unknown. In this study, the reactivity of three main contact allergens found in propolis, namely, caffeic acid (CA), caffeic acid 1,1-dimethylallyl ester (CAAE), and caffeic acid phenethyl ester (CAPE), was investigated. These compounds were initially subjected to the kinetic direct peptide reactivity assay to categorize the sensitization potency of CA, CAAE, and CAPE, but the data obtained was deemed too unreliable to confidently classify their skin sensitization potential based on this assay alone. To further investigate the chemistry involved in generating possible skin allergy-inducing protein adducts, model peptide reactions with CA, CAAE, and CAPE were conducted and analyzed via liquid chromatography-high-resolution mass spectrometry. Reactions between CA, CAAE, and CAPE and a cysteine-containing peptide in the presence of oxygen, both in closed and open systems, were monitored at specific time points. These studies revealed the formation of two different adducts, one corresponding to thiol addition to the α,β-unsaturated carbonyl region of the caffeic structure and the second corresponding to thiol addition to the catechol, after air oxidation to o-quinone. Observation of these peptide adducts classifies these compounds as prehaptens. Interestingly, no adduct formation was observed when the same reactions were performed under oxygen-free conditions, highlighting the importance of air oxidation processes in CA, CAAE, and CAPE adduct formation. Additionally, through NMR analysis, we found that thiol addition occurs at the C-2 position in the aromatic ring of the CA derivatives. Our results emphasize the importance of air oxidation in the sensitization potency of propolis and shed light on the chemical structures of the resultant haptens which could trigger allergic reactions in vivo.

Nature-Derived Epoxy Resin Monomers with Reduced Sensitizing Capacity─Isosorbide-Based Bis-Epoxides

Epoxy resin systems (ERSs) are a class of thermosetting resins that become thermostable and insoluble polymers upon curing. They are widely used as components of protective surfaces, adhesives, and paints and in the manufacturing of composites in the plastics industry. The diglycidyl ether of bisphenol A (DGEBA) is used in 75-90% of ERSs and is thus by far the most used epoxy resin monomer (ERM). Unfortunately, DGEBA is a strong skin sensitizer and it is one of the most common causes of occupational contact dermatitis. Furthermore, DGEBA is synthesized from bisphenol A (BPA), which is a petroleum-derived chemical with endocrine-disruptive properties. In this work, we have used isosorbide, a renewable and nontoxic sugar-based material, as an alternative to BPA in the design of ERMs. Three different bis-epoxide isosorbide derivatives were synthesized: the diglycidyl ether of isosorbide (1) and two novel isosorbide-based bis-epoxides containing either a benzoic ester (2) or a benzyl ether linkage (3). Assessment of the in vivo sensitizing potency of the isosorbide bis-epoxides in the murine local lymph node assay (LLNA) showed that all three compounds were significantly less sensitizing than DGEBA, especially 2 which was nonsensitizing up to 25% w/v. The peptide reactivity showed the same order of reactivity as the LLNA, i.e., 2 being the least reactive, followed by 3 and then 1, which displayed similar peptide reactivity as DGEBA. Skin permeation of 2 and 3 was compared to DGEBA using ex vivo pig skin and static Franz cells. The preliminary investigations of the technical properties of the polymers formed from 1-3 were promising. Although further investigations of the technical properties are needed, all isosorbide bis-epoxides have the potential to be less sensitizing renewable replacements of DGEBA, especially 2 that had the lowest sensitizing potency in vivo as well as the lowest peptide reactivity.

Pathways to Identify Electrophiles In Vivo Using Hemoglobin Adducts: Hydroxypropanoic Acid Valine Adduct and Its Possible Precursors

Analytical methods and tools for the characterization of the human exposome by untargeted mass spectrometry approaches are advancing rapidly. Adductomics methods have been developed for untargeted screening of short-lived electrophiles, in the form of adducts to proteins or DNA, in vivo. The identification of an adduct and its precursor electrophile in the blood is more complex than that of stable chemicals. The present work aims to illustrate procedures for the identification of an adduct to N-terminal valine in hemoglobin detected with adductomics, and pathways for the tracing of its precursor and possible exposure sources. Identification of the adduct proceeded via preparation and characterization of standards of adduct analytes. Possible precursor(s) and exposure sources were investigated by measurements in blood of adduct formation by precursors in vitro and adduct levels in vivo. The adduct was identified as hydroxypropanoic acid valine (HPA-Val) by verification with a synthesized reference. The HPA-Val was measured together with other adducts (from acrylamide, glycidamide, glycidol, and acrylic acid) in human blood (n = 51, schoolchildren). The HPA-Val levels ranged between 6 and 76 pmol/g hemoglobin. The analysis of reference samples from humans and rodents showed that the HPA-Val adduct was observed in all studied samples. No correlation of the HPA-Val level with the other studied adducts was observed in humans, nor was an increase in tobacco smokers observed. A small increase was observed in rodents exposed to glycidol. The formation of the HPA-Val adduct upon incubation of blood with glycidic acid (an epoxide) was shown. The relatively high adduct levels observed in vivo in relation to the measured reactivity of the epoxide, and the fact that the epoxide is not described as naturally occurring, suggest that glycidic acid is not the only precursor of the HPA-Val adduct identified in vivo. Another endogenous electrophile is suspected to contribute to the in vivo HPA-Val adduct level.

Exploring ethical issues arising from a problem-solving intervention in the Swedish Primary Care

Background

Common mental disorders count for a large percentage of sick leave cases in Europe and in Sweden. Problem-solving with workplace involvement have shown promising results in reducing the number of sick leave days for employees on sick leave for these conditions. Engaging the workplace by for example including the first-line manager in the return-to-work process changes the usual role of the primary care. Hence, this study aims to explore ethical issues that potentially arise when introducing workplace involvement as part of a problem-solving intervention.

Methods

A qualitative study in the Swedish Primary Care using data from semi-structured interviews with rehabilitation coordinators (n = 6), employees on sick leave for common mental disorders (n = 13), and their first-line managers (n = 8). A theoretical framework for systematic identification of ethical aspects of healthcare technologies was used to guide the interviews and reporting of results. Content analysis was used to code the data, searching for latent content. Ethical issues related to the ethical values privacy, identity, autonomy, professional values, third party, equality and justice were identified and described. The analysis was concluded by a normative discussion.

Results

Ethical issues were identified such as difficulties for the employees to control personal information. A need to create an integrated role of a patient and an employee and for coordinators to act neutral instead of as a patient advocate. Managers needed to balance the needs of the organization with the needs of the employee. A pre-requisite for participation was agreeing to manager involvement which may affect the equality of the intervention.

Conclusions

A conversation about sharing of information, roles, responsibilities and expectations during the rehabilitation should be initiated early and be continuous. Managers need support in learning the “how to” when having an employee on sick leave due to a common mental disorder.

Key messages

Haptenation of Macrophage Migration Inhibitory Factor: A Potential Biomarker for Contact Hypersensitivity

The immunological response in contact hypersensitivity is incited by small electrophilic compounds, known as haptens, that react with endogenous proteins after skin absorption. However, the identity of hapten-modified proteins seen as immunogenic remains as yet largely unknown. In a recent study, we have for the first time identified a hapten-modified protein in the local lymph nodes of mice treated topically with the model hapten tetramethylrhodamine isothiocyanate (TRITC). The TRITC modification was located on the N-terminal proline of the protein macrophage migration inhibitory factor (MIF). The focus of the current study was to investigate the presence of the same hapten-protein conjugate in blood samples from mice treated topically with TRITC. Furthermore, TRITC modifications of the two major blood proteins, namely hemoglobin (Hb) and albumin (Alb), as well as TRITC modifications of MIF other than the N-terminal proline, were examined. Following incubation with different molar ratios of TRITC, a proteomic approach was applied to characterize conjugate formation of the three aforementioned proteins, using high resolution mass spectrometry (HRMS). The targeted screening of the TRITC-treated mice blood and lymph node samples for these sites led to the identification of only the same TRITC-MIF conjugate previously detected in the lymph nodes. No Hb and Alb conjugates were detected. Quantification of both the TRITC-modified and unmodified N-terminal peptide of MIF in blood and lymph node samples gave interesting insights of MIF’s role in murine contact hypersensitivity. Incubation of MIF with four different haptens encompassing different reactivity mechanisms and potencies, showed adduct formation at different amino acid residues, suggesting that MIF can be the preferred target for a wide variety of haptens. The present study provides essential progress toward understanding of hapten-protein conjugate formation in contact hypersensitivity and identifies hapten-modified MIF as a potential biomarker for this condition. Further investigation of MIF as a target protein can be a next step to determine if MIF is a biomarker that can be used to develop better diagnostic tools and targeted therapeutics for individuals with allergic contact dermatitis.

Novel 4-Hydroxybenzyl Adducts in Human Hemoglobin: Structures and Mechanisms of Formation

Humans are exposed to large numbers of electrophiles from their diet, the environment, and endogenous physiological processes. Adducts formed at the N-terminal valine of hemoglobin are often used as biomarkers of human exposure to electrophilic compounds. We previously reported the formation of hemoglobin N-terminal valine adducts (added mass, 106.042 Da) in the blood of human smokers and nonsmokers and identified their structure as 4-hydroxybenzyl-Val. In the present work, mass spectrometry-based proteomics was utilized to identify additional sites for 4-hydroxybenzyl adduct formation at internal nucleophilic amino acid side chains within hemoglobin. Hemoglobin isolated from human blood was treated with para-quinone methide (para-QM) followed by global nanoLC-MS/MS and targeted nanoLC-MS/MS to identify amino acid residues containing the 4-hydroxybenzyl modification. Our experiments revealed the formation of 4-hydroxybenzyl adducts at the αHis20, αTyr24, αTyr42, αHis45, βSer72, βThr84, βThr87, βSer89, βHis92, βCys93, βCys112, βThr123, and βHis143 residues (in addition to N-terminal valine) through characteristic MS/MS spectra. These amino acid side chains had variable reactivity toward para-QM with αHis45, αTyr42, βCys93, βHis92, and βSer72 forming the largest numbers of adducts upon exposure to para-QM. Two additional mechanisms for formation of 4-hydroxybenzyl adducts in humans were investigated: exposure to 4-hydroxybenzaldehyde (4-HBA) followed by reduction and UV-mediated reactions of hemoglobin with tyrosine. Exposure of hemoglobin to a 5-fold molar excess of 4-HBA followed by reduction with sodium cyanoborohydride produced 4-hydroxybenzyl adducts at several amino acid side chains of which αHis20, αTyr24, αTyr42, αHis45, βSer44, βThr84, and βHis92 were verified in targeted mass spectrometry experiments. Similarly, exposure of human blood to ultraviolet radiation produced 4-hydroxybenzyl adducts at αHis20, αTyr24, αTyr42, αHis45, βSer44, βThr84, and βSer89. Overall, our results reveal that 4-hydroxybenzyl adducts form at multiple nucleophilic sites of hemoglobin and that para-QM is the most likely source of these adducts in humans.

Characterizing Adduct Formation of Electrophilic Skin Allergens with Human Serum Albumin and Hemoglobin

Skin (contact) allergy, the most predominant form of immunotoxicity in humans, is caused by small electrophilic compounds (haptens) that modify endogenous proteins. Approximately 20% of the general population in the Western world is affected by contact allergy. Although the importance of the hapten–protein conjugates is well established in the initiation of the immunological reaction, not much progress has been made regarding identification of these conjugates in vivo or exploration of their potential as diagnostic tools. In this study, the human serum albumin (HSA) and human hemoglobin (Hb) adductome for three representative contact allergens with different chemical properties, 1-chloro-2,4-dinitrobenzene (DNCB), 1,2-epoxy-3-phenoxypropane (PGE), and 2-bromo-2-(bromomethyl)glutaronitrile (MDBGN), were studied. Plasma and red blood cell lysate were used as a source for HSA and Hb, respectively. The Direct Peptide Reactivity Assay was used to investigate adduct formation of MDBGN with nucleophilic moieties and revealed that MDGBN is converted to 2-methylenepentanedinitrile in the presence of sulfhydryl groups prior to adduct formation. Following incubation of HSA and Hb with haptens, an Orbitrap Q Exactive high-resolution mass spectrometer was used to perform an initial untargeted analysis to screen for adduct formation, followed by confirmation by targeted Parallel Reaction Monitoring analysis. Although a subset of adducted sites was confirmed by targeted analysis, only some of the adducted peptides showed an increase in the relative amount of the adducted peptide with an increased concentration of hapten. In total, seven adduct sites for HSA and eight for Hb were confirmed for DNCB and PGE. These sites are believed to be the most reactive. Further, three of the HSA sites (Cys₃₄, Cys₆₂, and Lys₁₉₀) and six of the Hb sites (subunit α: Val₁, His₄₅, His₇₂; subunit β: Cys₉₃, His₉₇, and Cys₁₁₂) were haptenated already at the lowest level of hapten to protein molar ratio (0.1:1), indicating that these sites are the most likely to be modified in vivo. To the best of our knowledge, this is the first time that the adductome of Hb has been studied in the context of contact allergens. Identification of the most reactive sites of abundant proteins, such as HSA and Hb, is the first step toward identification of contact allergy biomarkers that can be used for biomonitoring and to develop better diagnostic tools based on a blood sample.

N-Glycosylation profiling of intact target proteins by high-resolution mass spectrometry (MS) and glycan analysis using ion mobility-MS/MS

Glycosylation characterization could lead to the discovery of biomarkers and is crucial in quality control of biopharmaceuticals. Here we present a method to quantify glycoforms on intact proteins, with parallel glycan identification by IMS-MS/MS.

Development of New Epoxy Resin Monomers - A Delicate Balance between Skin Allergy and Polymerization Properties

Epoxy resin monomers (ERMs) are used as building blocks for thermosetting polymers in applications where strong, flexible, and lightweight materials are required. Most epoxy resins are polymers of diglycidyl ether of bisphenol A (DGEBA). It is highly allergenic and causes occupational allergic contact dermatitis and contact allergy in the general population. Thus, measures to prevent exposure by protective clothing and education are not enough. This work describes a continuation of our research aiming at reducing the skin-sensitizing potency of ERMs while maintaining the ability to form polymers. Alternative ERMs were designed and synthesized whereafter the sensitizing potency was determined using the murine local lymph node assay (LLNA). The reactivity of the diepoxides toward a nucleophilic peptide was investigated, and the differences in reactivity explained using computational studies. The diepoxides were reacted with triethylenetetramine, and the formed polymers were tested for technical applicability using thermogravimetric analysis. We had previously shown that the absence of an oxygen atom in the side chains or removal of aromaticity reduced the sensitizing potency compared to that of DGEBA. Thus, a cycloaliphatic analogue 1 of DGEBA without ether oxygen in the side chains was considered promising and was synthesized. As predicted, the sensitizing potency was considerably reduced (10 times) compared to that of DGEBA. However, the technical properties of the polymer of this compound were not considered sufficient. More polar aromatic analogues were investigated, but they could not compete with our previously described ERMs regarding polymerization properties and with 1 regarding low skin sensitization properties. Development of alternative epoxy materials is a delicate balance between allergenic activity and polymerization properties. Tuning of structural properties together with investigation of polymerization conditions combined with skin sensitization studies should be used in industrial research and development. ERM 1 could be used as a lead compound for further studies of aliphatic ERMs.

Discovery of Novel N-(4-Hydroxybenzyl)valine Hemoglobin Adducts in Human Blood

Humans are exposed to a wide range of electrophilic compounds present in our diet and environment or formed endogenously as part of normal physiological processes. These electrophiles can modify nucleophilic sites of proteins and DNA to form covalent adducts. Recently, powerful untargeted adductomic approaches have been developed for systematic screening of these adducts in human blood. Our earlier untargeted adductomics study detected 19 unknown adducts to N-terminal valine in hemoglobin (Hb) in human blood. We now describe a full characterization of one of these adducts, which corresponds to the addition of a 4-hydroxybenzyl (4-OHBn) group to N-terminal valine in Hb to form N(4-hydroxybenzyl)valine (4-OHBn-Val). The adduct structure was determined by comparison of its accurate mass, HPLC retention time, and MS/MS fragmentation to that of authentic standards prepared by chemical synthesis. Average 4-OHBn-Val adduct concentrations in 12 human blood samples were estimated to 380 ± 160 pmol/g Hb. Two possible routes of 4-OHBnVal adduct formation are proposed using two different precursor electrophiles: 4-quinone methide (4-QM) and 4-hydroxybenzaldehyde (4-OHBA). We found that 4-QM reacts rapidly with valine to form the 4-OHBn-Val adduct; however, the quinone methide is unstable under physiological conditions due to hydrolysis. It was shown that 4-OHBA forms reversible Schiff base adducts with valine, which can be stabilized via reduction in blood generating the 4-OHBn-Val adduct. In addition, trace amounts of isomeric 2-hydroxybenzyl-valine (2-OHBn-Val) adducts were detected in 12 human blood samples (estimated mean adduct level, 5.0 ± 1.4 pmol/g Hb). Further studies are needed to quantify the contributions from identified possible precursor electrophiles to the observed hydroxybenzyl adducts in humans.

Is the matched extreme case-control design more powerful than the nested case-control design?

For time-to-event data, the study sample is commonly selected using the nested case-control design in which controls are selected at the event time of each case. An alternative sampling strategy is to sample all controls at the same (pre-specified) time, which can either be at the last event time or further out in time. Such controls are the long-term survivors and may therefore constitute a more 'extreme' comparison group and be more informative than controls from the nested case-control design. We investigate this potential information gain by comparing the power of various 'extreme' case-control designs with that of the nested case-control design using simulation studies. We derive an expression for the theoretical average information in a nested and extreme case-control pair for the situation of a single binary exposure. Comparisons reveal that the efficiency of the extreme case-control design increases when the controls are sampled further out in time. In an application to a study of dementia, we identified Apolipoprotein E as a risk factor using a 1:1 extreme case-control design, which provided a hazard ratio estimate with a smaller standard error than that of a 2:1 nested case-control design.

The Fate of a Hapten - From the Skin to Modification of Macrophage Migration Inhibitory Factor (MIF) in Lymph Nodes

Skin (contact) allergy, the most prevalent form of immunotoxicity in humans, is caused by low molecular weight chemicals (haptens) that penetrate stratum corneum and modify endogenous proteins. The fate of haptens after cutaneous absorption, especially what protein(s) they react with, is largely unknown. In this study the fluorescent hapten tetramethylrhodamine isothiocyanate (TRITC) was used to identify hapten-protein conjugates in the local lymph nodes after topical application, as they play a key role in activation of the adaptive immune system. TRITC interacted with dendritic cells but also with T and B cells in the lymph nodes as shown by flow cytometry. Identification of the most abundant TRITC-modified protein in lymph nodes by tandem mass spectrometry revealed TRITC-modification of the N-terminal proline of macrophage migration inhibitory factor (MIF) – an evolutionary well-conserved protein involved in cell-mediated immunity and inflammation. This is the first time a hapten-modified protein has been identified in lymph nodes after topical administration of the hapten. Most haptens are electrophiles and can therefore modify the N-terminal proline of MIF, which has an unusually reactive amino group under physiological conditions; thus, modification of MIF by haptens may have an immunomodulating role in contact allergy as well as in other immunotoxicity reactions.

Honokiol bis-dichloroacetate (Honokiol DCA) demonstrates activity in vemurafenib-resistant melanoma in vivo

The majority of human melanomas bears BRAF mutations and thus is treated with inhibitors of BRAF, such as vemurafenib. While patients with BRAF mutations often demonstrate an initial dramatic response to vemurafenib, relapse is extremely common. Thus, novel agents are needed for the treatment of these aggressive melanomas. Honokiol is a small molecule compound derived from Magnolia grandiflora that has activity against solid tumors and hematopoietic neoplasms. In order to increase the lipophilicity of honokiol, we have synthesized honokiol DCA, the dichloroacetate ester of honokiol. In addition, we synthesized a novel fluorinated honokiol analog, bis-trifluoromethyl-bis-(4-hydroxy-3-allylphenyl) methane (hexafluoro). Both compounds exhibited activity against A375 melanoma in vivo, but honokiol DCA was more active. Gene arrays comparing treated with vehicle control tumors demonstrated induction of the respiratory enzyme succinate dehydrogenase B (SDHB) by treatment, suggesting that our honokiol analogs induce respiration in vivo. We then examined its effect against a pair of melanomas, LM36 and LM36R, in which LM36R differs from LM36 in that LM36R has acquired vemurafenib resistance. Honokiol DCA demonstrated in vivo activity against LM36R (vemurafenib resistant) but not against parental LM36. Honokiol DCA and hexafluoro inhibited the phosphorylation of DRP1, thus stimulating a phenotype suggestive of respiration through mitochondrial normalization. Honokiol DCA may act in vemurafenib resistant melanomas to increase both respiration and reactive oxygen generation, leading to activity against aggressive melanoma in vivo.

Particle-based N-linked glycan analysis of selected proteins from biological samples using nonglycosylated binders

Glycosylation is one of the most common and important post-translational modifications, influencing both the chemical and the biological properties of proteins. Studying the glycosylation of the entire protein population of a sample can be challenging because variations in the concentrations of certain proteins can enhance or obscure changes in glycosylation. Furthermore, alterations in the glycosylation pattern of individual proteins, exhibiting larger variability in disease states, have been suggested as biomarkers for different types of cancer, as well as inflammatory and neurodegenerative diseases. In this paper, we present a rapid and efficient method for glycosylation analysis of individual proteins focusing on changes in the degree of fucosylation or other alterations to the core structure of the glycans, such as the presence of bisecting N-acetylglucosamines and a modified degree of branching. Streptavidin-coated magnetic beads are used in combination with genetically engineered immunoaffinity binders, called VHH antibody fragments. A major advantage of the VHHs is that they are nonglycosylated; thus, enzymatic release of glycans from the targeted protein can be performed directly on the beads. After deglycosylation, the glycans are analyzed by MALDI-TOF-MS. The developed method was evaluated concerning its specificity, and thereafter implemented for studying the glycosylation pattern of two different proteins, alpha-1-antitrypsin and transferrin, in human serum and cerebrospinal fluid. To our knowledge, this is the first example of a protein array-type experiment that employs bead-based immunoaffinity purification in combination with mass spectrometry analysis for fast and efficient glycan analysis of individual proteins in biological fluid.

Afri-Can Forum 2

A1 Introduction to the 2nd synchronicity forum of GHRI/CHVI-funded Canadian and African HIV prevention and vaccine teams

O1 Voluntary medical male circumcision for prevention of heterosexual transmission of HIV in adult males in Soweto: What do indicators and incidence rate show?

Hillary Mukudu, Neil Martinson, Benn Sartorius

O2 Developing a peer-led community mobilization program for sex workers in Soweto: HIV risk and demographics

Jenny Coetzee, Janan Dietrich, Kgaugelo Mokgatswana, Rachel Jewkes, Glenda E. Gray

O3 Salient beliefs about adherence: A qualitative survey conducted as part of the demonstration study on "treatment as prevention" (TasP) and "pre-exposure prophylaxis" (PrEP) among female sex workers (FSWS) in Cotonou, Benin

Marylène Dugas, Luc Béhanzin, Fernand A. Guédou, Marie-Pierre Gagnon, Michel Alary

O4 Relative perception of risk as a driver of unsafe sexual practices among key populations: Cases of fisherfolk and women and their partners involved in multiple sexual partnerships in Uganda

Rwamahe Rutakumwa, Martin Mbonye, Thadeus Kiwanuka, Sarah Nakamanya, Richard Muhumuza, Winfred Nalukenge, Janet Seeley

O5 Exploring the acceptability of new biomedical HIV prevention technologies among MSM, adolescents and heterosexual adults in South Africa

Millicent Atujuna, Melissa Wallace, Ben Brown, Linda Gail Bekker, Peter A. Newman

O6 HIV-susceptible target cells in foreskins after voluntary medical male circumcision in South Africa

Rushil Harryparsad, Abraham J. Olivier, Heather B. Jaspan, Douglas Wilson, Janan Dietrich, Neil Martinson, Hillary Mukudu, Nonhlanhla Mkhize, Lynn Morris, Gianguido Cianci, Minh Dinh, Thomas Hope, Jo-Ann S. Passmore, Clive M. Gray

O7 HIV-1 proteins activate innate immune responses via TLR2 heterodimers

Bethany M. Henrick, Xiao-Dan Yao, Kenneth L. Rosenthal, the INFANT Study Team

O8 Characterization of an innate factor in human milk and mechanisms of action against HIV-1

Bethany M. Henrick, Xiao-Dan Yao, Anna G. Drannik, Alash’le Abimiku, Kenneth L. Rosenthal, the INFANT Study Team

O9 Secretor status and susceptibility to HIV infections among female sex workers in Nairobi, Kenya

Nadia Chanzu, Walter Mwanda, Julius Oyugi, Omu Anzala

O10 Natural Killer cell recall responsiveness to Gag-HIV-1 peptides of HIV-1 exposed but uninfected subjects are associated with peripheral CXCR6+ NK cell subsets

Moustapha Mbow, Sabelle Jallow, Moussa Thiam, Alberta Davis, Assane Diouf, Cheikh T. Ndour, Moussa Seydi, Tandakha N. Dieye, Souleymane Mboup, Martin Goodier, Eleanor Rilley, Assan Jaye

O11 Profiles of resistance: Local innate mucosal immunity to HIV-1 in commercial sex workers

Xiao-Dan Yao, RW. Omange, Bethany M. Henrick, Richard T. Lester, Joshua Kimani, T. Blake Ball, Francis A. Plummer, Kenneth L. Rosenthal

O12 Early antiretroviral therapy and pre-exposure prophylaxis for HIV prevention among female sex workers in Cotonou, Benin: A demonstration project

Luc Béhanzin, Fernand A. Guédou, Nassirou Geraldo, Ella Goma Mastétsé, Jerôme Charles Sossa, Marcel Djimon Zannou, Michel Alary

O13 Building capacity for HIV prevention trials: Preliminary data from a Nigerian cohort of HIV exposed sero-negatives (HESN)

Sophia Osawe, Evaezi Okpokoro, Felicia Okolo, Stephen Umaru, Rebecca Abimiku, Sam Audu, Pam Datong, Alash’le Abimiku

O14 Equipping healthcare professionals with skills required for the conduct of clinical trials in an effort to build capacity. Lessons learned

Jacquelyn Nyange, Joyce Olenja, Gaudensia Mutua, Walter Jaoko, Gloria Omosa-Manyonyi, Bashir Farah, Maureen Khaniri, Omu Anzala

O15 Educational technology to support active learning for HIV researchers and planners

Anne Cockcroft, Kendra Tonkin, Indu Girish, Puna Mhati, Ashley Cunningham, Neil Andersson

O16 From Lake Kivu (Rwanda) and Lake Malawi (Tanzania) to the shores of Lake Victoria (Uganda): Strengthening laboratory capacity through Good Clinical Laboratory Practice training

Bashir Farah, Jackton Indangasi, Walter Jaoko, Gaudensia Mutua, Maureen Khaniri, Jacquelyn Nyange, Omu Anzala

O17 Rilpivirine and etravirine resistance mutations in HIV-1 subtype C infected patients on a non-nucleoside reverse transcriptase inhibitor-based combination antiretroviral therapy in Botswana

Thabo Diphoko, Simani Gaseitsiwe, Victoria Maiswe, Thato Iketleng, Dorcas Maruapula, Keabetswe Bedi, Sikhulile Moyo, Rosemary Musonda, Mark Wainberg, Joseph Makhema, Vladimir Novitsky, Richard Marlink, Max Essex

O18 From home-based HIV testing to initiation of treatment: The AIDS Support Organization (TASO) Experience with Home-based HIV Counselling and Testing (HBHCT) among Adolescents in Uganda, 2005-2011

Stephen Okoboi, Livingstone Ssali, Sam Kalibala, Josephine Birungi, Aggrey Egessa, Jonathan Wangisi, Lyavala Joanne Okullu, Celestin Bakanda, Francis Obare⁴¹

O19 Feasibility study on using real time medication monitoring among HIV infected and Tuberculosis patients in Kilimanjaro, Tanzania

I. Marion Sumari-de Boer, Hadija H. Semvua, Jossy van den Boogaard, Krisanta W. Kiwango, Kennedy M. Ngowi, Pythia T. Nieuwkerk, Rob E. Aarnoutse, Ireen Kiwelu, Eva Muro, Gibson S. Kibiki

O20 Deaths still among sero-discordant cohort in Nigeria despite Access to treatment

Ruth Datiri, Grace Choji, Sophia Osawe, Evaezi Okpokoro, Felicia Okolo, Stephen Umaru, Rebecca Abimiku, Samuel Audu, Pam Datong, Alash’le Abimiku

O21 Therapeutic HIV-1 vaccine trials in Denmark and Guinea-Bissau

Fomsgaard A, Karlsson I, Jensen KJ, Jensen SS, Leo-Hansen C, Jespersen S, Da Silva Té D, Rodrigues CM, da Silva ZJ, Janitzek CM, Gerstoft J, Kronborg G, the WAPHIR Group

O22 Willingness to participate in a HIV vaccine Trial among HIV exposed sero-negative (HESN) persons in Jos, Nigeria

Evaezi Okpokoro, Sophia Osawe, Ruth Daitiri, Grace Choji, Stephen Umaru, Felicia Okolo, Pam Datong, Alash'le Abimiku

O23 Clinical research volunteers’ perceptions and experiences of screening for enrolment at KAVI-Institute of Clinical Research, Kenya

Nyariki Emily, Olenja Joyce, Lorway R. Robert, Anzala Anzala

O24 Gut microbiome, HIV-exposure, and vaccine responses in South African infants

Katie Viljoen, Jerome Wendoh, Elvis Kidzeru, Ulas Karaoz, Eoin Brodie, Gerrit Botha, Nicola Mulder, Clive Gray, William Cameron, Alain Stintzi, Heather Jaspan, for the INFANT study team

O25 Analysis of HIV pol diversity in the concentrated HIV epidemic in Saskatchewan

Paul N. Levett, David Alexander, Naveed Gulzar, Prabvir S. Grewal, Art F. Y. Poon, Zabrina Brumme, P. Richard Harrigan, James I. Brooks, Paul A. Sandstrom, Stryker Calvez, Stephen E. Sanche, Jamie K. Scott

P1 Evaluating a HIV vaccine research community engagement programme at two HIV prevention research centres in the Western Cape

Leslie Swartz, Ashraf Kagee, Anthea Lesch, Zuhayr Kafaar, Anneliese De Wet

P2 Validating HIV acquisition risk score using a cohort HIV exposed sero-negative persons in a discordant relationship in Jos, Nigeria, West Africa

Evaezi Okpokoro, Sophia Osawe, Ruth Daitiri, Grace Choji, Stephen Umaru, Felicia Okolo, Pam Datong, Alash'le Abimiku

P3 Bridging the gap between adults and adolescents and youth adults (AYA) – Employing a youth-centred approach to investigate HIV risk among AYA in Soweto and Durban, South Africa

Janan Dietrich, Tricia Smith, Laura Cotton, Stefanie Hornschuh, Martin van der Watt, Cari L. Miller, Glenda Gray, Jenni Smit, Manjeetha Jaggernath, Thumbi Ndung’u, Mark Brockman, Angela Kaida, on behalf of the AYAZAZI study teams

P4 Neighbours to sex workers: A key population that has been ignored

Maureen Akolo, Joshua Kimani, Prof Larry Gelmon, Michael Chitwa, Justus Osero

P5 Young women’s access to structural support programmes in a district of Botswana

Anne Cockcroft, Nobantu Marokoane, Leagajang Kgakole, Boikhutso Maswabi, Neo Mpofu, Umaira Ansari, Neil Andersson

P6 Voices for action from peri-urban Ugandan students, teachers and parents on HIV/STI prevention: Qualitative research results

Nakinobe Elizabeth, Miiro George Mukalazi, Zalwango Flavia, Nakiyingi-Miiro Jessica, Kaleebu Potiano

P7 Engaging Social Media as an education tool on the fly: The use of Facebook for HIV and Ebola prevention and awareness amongst adolescents in Uganda

John Ross Semwanga, Emily Nyanzi, Saidat Namuli Musoke, Elizabeth Nakinobe, George Miiro, Edward Katongole Mbidde, Tom Lutalo, Pontiano Kaleebu

P8 Circulating HIV-1 subtypes among sexual minority populations in Zambia

Ray Handema, Graham P. Chianzu

P9 The Development of HIV Bio-bank resource management to support clinical trial and Intervention research: WAPHIR experience

Moussa Thiam, Diabou Diagne-Gueye, Mame K. Ndiaye, Moustapha Mbow, Birahim P. Ndiaye, Ibrahima Traore, Mamadou C. Dia, Gilleh Thomas, Coumba Tour-Kane, Souleymane Mboup, Assan Jaye

P10 Capacity building for clinical trials as a novel approach for scaling up HIV prevention research initiatives in East Africa: achievements and challenges

Emily Nyanzi, Edward Katongole Mbidde, Pontiano Kaleebu, Juliet Mpendo, Joshua Kimani, Josephine Birungi, Winnie Muyindike, Andrew Kambugu

P11 Community and media perspective of research; an advocacy workshop on HIV prevention research

Hachizovu Sebastian, Handema Ray, Chaponda Mike, Kabuya Jean Bertin, Mulenga Modest

P12 Development of a quantitative HIV-1 and HIV-2 real time PCR (qRT-PCR) viral load assay

Moussa Thiam, Omar Janha, Alberta Davis, Alfred Amambua-Ngwa, Davis C. Nwakanma, Souleymane Mboup, Assan Jaye

P13 Differential effects of sex in a West African Cohort of HIV-1, HIV-2 and HIV-1/2 dual infected patients: Men are worse off

Sanne Jespersen, Bo Langhoff Hønge, Joakim Esbjörnsson, Candida Medina, David Da Silva TÉ, Faustino Gomes Correira, Alex Lund Laursen, Lars Østergaard, Andreas Andersen, Peter Aaby, Christian Erikstrup, Christian Wejse, for the Bissau HIV Cohort study group

P14 HIV-infected adolescents in transition from pediatric to adult HIV care in Dakar, Senegal: sample characteristics and immunological and virological profiles

Siry Dieye, Moussa Sarr, Haby Sy, Helene D Mbodj, Marianne Ndiaye, Amy Ndiaye, Seydi Moussa, Assan Jaye, Souleymane Mboup¹⁰⁰

P15 Molecular characterization of vertically transmitted HIV-1 among children born to HIV-1 seropositive mothers in Northern Tanzania

Balthazar M. Nyombi, Elichilia R. Shao, Innocent B. Chilumba, Sikhulile Moyo, Simani Gaseitsiwe, Rosemary Musonda

P16 Breast-fed HIV-1 exposed infants play catch up. A preliminary report

Pam Datong, Bucky Inyang, Sophia Osawe, Abel Izang, Chundung Cole, Felicia Okolo, Bill Cameron, Kenneth Rosenthal, Clive Gray, Heather Jaspan, Alash’le Abimiku, the INFANT study team

P17 The frequency of N348I mutation in patient failing combination antiretroviral treatment In Botswana

Boitumelo Seraise, Kerstin Andrea-Marobela, Sikhulile Moyo, Rosemary Musonda, Joseph Makhema, Max Essex, Simani Gaseitsiwe

Metabolic and Hormonal Response to a Feed-challenge Test in Lean and Overweight Dogs

Background

Obese dogs risk poor life quality, creating a need for increased knowledge of metabolism in overweight dogs.

Objectives

Investigate postprandial metabolic and hormonal responses to a high‐fat mixed‐meal in dogs and responses of lean versus overweight dogs.

Animals

Twenty‐eight healthy intact male Labrador Retrievers were included.

Methods

Prospective observational study. Twelve dogs were grouped as lean (body condition score (BCS 4–5), 10 as slightly overweight (BCS 6), and 6 as overweight (BCS 6.5–8) on a 9‐point scale. After an overnight fast, urine and blood samples were collected. Dogs were then fed a high‐fat mixed‐meal, and blood was collected hourly for 4 hours and urine after 3 hours.

Results

Postprandial concentrations of insulin and glucagon were increased at 1 hour (both P < 0.0001), triglycerides at 2 hours (P < 0.0001), and glucose at 3 hours (P = 0.004); and all remained increased throughout the feed‐challenge in all dogs. Postprandial urine cortisol/creatinine ratio was higher than fasting values (P = 0.001). Comparing between groups, there was an overall higher triglyceride response in overweight compared to lean (P = 0.001) and slightly overweight (P = 0.015) dogs. Overweight dogs also had higher fasting cortisol/creatinine ratio compared to lean dogs (P = 0.024).

Conclusions and Clinical Importance

Postprandial responses of dogs to a high‐fat mixed‐meal were similar to those previously reported in people. The higher postprandial triglyceride response and fasting cortisol/creatinine ratio in the overweight dogs could be early signs of metabolic imbalance. Thus, although overweight dogs often appear healthy, metabolic alterations might be present.

Effect of tablets containing probiotic bacteria (Lactobacillus reuteri) on early caries lesions in adolescents: a pilot study

The objective of the study was to investigate the effect of tablets containing probiotic lactobacilli on early caries lesions in adolescents with quantitative light-induced fluorescence (QLF). 36 healthy adolescents of both sexes (12-17 years of age) were enrolled and randomly allocated to a placebo-controlled trial with two parallel groups. The test group received two tablets daily containing two strains of Lactobacillus reuteri (DSM 17938 and ATCC PTA 5289) for a period of three months, while the control group got identical placebo tablets without live bacteria. The primary outcome was QLF-readings (change in fluorescence, ΔF and lesion area, mm2) at baseline and after 3 months, conducted at two buccal sites of each individual, pre-selected with clearly visible clinical signs of enamel demineralisation (white spots). Significantly more premolars were allocated to the placebo group, while the test group had more incisors (P<0.05). There were no statistically significant differences in fluorescence values between the groups, neither at baseline, nor at the follow-up. There was however a significant decrease in fluorescence over time in the test group, but not in the placebo group (P<0.05). No alterations of the lesion area (ΔA) were found in any group. The inter-examiner intra-class correlation coefficient-value for QLF-readings was excellent. No side- or adverse effects were reported during the intervention period. This pilot study found a significant decrease over time in the test group. However, no statistically significant differences in fluorescence values between the groups were found. Hence, the null hypothesis could not be rejected.

Solenopsin A and analogs exhibit ceramide-like biological activity

BACKGROUND

(-)-Solenopsin A is a piperidine alkaloid that is a component of the venom of the fire ant Solenopsis invicta. Previously, we have demonstrated that solenopsin exhibit anti-angiogenic activity and downregulate phosphoinositol-3 kinase (PI3K) in the p53 deficient renal cell carcinoma cell line 786-O. Solenopsin has structural similarities to ceramide, a major endogenous regulator of cell signaling and cancer therapy induced apoptosis.

METHODS

Different analogs of solenopsin were synthesized in order to explore structure-activity relationships. The anti-proliferative effect of solenopsin and analogs was tested on six different cell lines, including three tumor cell lines, two normal cutaneous cell lines, and one immortalized hyperproliferative cell line. FRET-based reporters were used to study the affect of solenopsin and analogs on Akt activity and PDK1 activation and sucrose density gradient fractionation was performed to examine recruitment of PTEN to membrane rafts. Western-blotting was used to evaluate the affect of solenopsin and analogs on the Akt and the MAPK 44/42 pathways in three different tumor cell lines. Measurement of cellular oxygen consumption rate together with autophagy staining was performed to study mitochondrial function. Finally, the affect of solenopsin and analogs on ROS production was investigated.

RESULTS

In this paper we demonstrate that solenopsin analogs with potent anti-proliferative effects can be synthesized from inexpensive dimethylpyridines. To determine whether solenopsin and analogs act as ceramide analogs, we examined the effect of solenopsin and analogs on two stereotypic sites of ceramide activity, namely at lipid rafts and mitochondria. We found that native solenopsin, (-)-solenopsin A, inhibits functional Akt activity and PDK1 activation in lipid rafts in a similar fashion as ceramide. Both cis and trans analogs of solenopsin reduce mitochondrial oxygen consumption, increase reactive oxygen, and kill tumor cells with elevated levels of Akt phosphorylation. However, only solenopsin induces mitophagy, like ceramide.

CONCLUSIONS

The requirements for ceramide induced mitophagy and inhibition of Akt activity and PDK1 activation in lipid rafts are under strict stereochemical control. The naturally occurring (-)-solenopsin A mimic some of the functions of ceramide and may be therapeutically useful in the treatment of hyperproliferative and malignant disorders of the skin, even in the presence of elevated levels of Akt.

Ketoprofen-induced formation of amino acid photoadducts: possible explanation for photocontact allergy to ketoprofen

Photocontact allergy is a well-known side effect of topical preparations of the nonsteroidal anti-inflammatory drug ketoprofen. Photocontact allergy to ketoprofen appears to induce a large number of photocross allergies to both structurally similar and structurally unrelated compounds. Contact and photocontact allergies are explained by structural modification of skin proteins by the allergen. This complex is recognized by the immune system, which initiates an immune response. We have studied ketoprofen's interaction with amino acids to better understand ketoprofen's photoallergenic ability. Irradiation of ketoprofen and amino acid analogues resulted in four different ketoprofen photodecarboxylation products (6-9) together with a fifth photoproduct (5). Dihydroquinazoline 5 was shown to be a reaction product between the indole moiety of 3-methylindole (Trp analogue) and the primary amine benzylamine (Lys analogue). In presence of air, dihydroquinazoline 5 quickly degrades into stable quinazolinone 12. The corresponding quinazolinone (17) was formed upon irradiation of ketoprofen and the amino acids N-acetyl-l-Trp ethyl ester and l-Lys ethyl ester. The formation of these models of an immunogenic complex starts with the ketoprofen-sensitized formation of singlet oxygen, which reacts with the indole moiety of Trp. The formed intermediate subsequently reacts with the primary amino functionality of Lys, or its analogue, to form a Trp-Lys adduct or a mimic thereof. The formation of a specific immunogenic complex that does not contain the allergen but that can still induce photocontact allergy would explain the large number of photocross allergies with ketoprofen. These allergens do not have to be structurally similar as long as they can generate singlet oxygen. To the best of our knowledge, there is no other suggested explanation for ketoprofen's photoallergenic properties that can account for the observed photocross allergies. The formation of a specific immunogenic complex that does not contain the allergen is a novel hypothesis in the field of contact and photocontact allergy.

Cytokines as immunological markers for systemic inflammation in dogs with pyometra

Pyometra is a disease in dogs caused by bacterial infection of the uterus and resulting in SIRS (systemic inflammatory response syndrome) in nearly 6 of 10 cases. Clinical diagnostic criteria for SIRS are relatively unspecific, and biomarkers for the diagnosis of pyometra and SIRS in dogs are needed. Serum samples from 32 dogs were used in this study and grouped into dogs with pyometra and SIRS, dogs with pyometra without SIRS and healthy controls. The serum concentrations of IFN-γ, IL-4, IL-6, IL-7, IL-8, IL-10, IL-15, IL-18 and TNF-α were measured using multiplex analyses. The serum concentrations of CRP (C-reactive protein) were determined using sandwich ELISA. IL-7, IL-8, IL-15, IL-18 and TNF-α were detected in >94% of samples. IL-10 was detected in 28% of samples, and IL-4, IL-6 and IFN-γ were undetectable. Higher serum concentrations of IL-7 (p < 0.05) were detected in SIRS-positive dogs with pyometra (n = 13) as compared with healthy controls (n = 11). The concentrations of IL-8 were higher in SIRS-positive dogs with pyometra compared to the SIRS-negative group (n = 8; p < 0.05). Positive correlations of IL-15 with IL-18 (p < 0.0001) and with the concentrations of IL-7 (p < 0.0001 for both) were found, although there was no significant difference between groups. Furthermore, IL-15 correlated with concentrations of CRP (p < 0.05), which were higher in dogs with pyometra compared to controls (p < 0.0001). Our data suggest a role of several cytokines in the development of a systemic disease in dogs with pyometra and a possible diagnostic value for serum CRP, IL-7, IL-15 and IL-18 in canine SIRS caused by pyometra.

Oxidative coupling as a biomimetic approach to the synthesis of scytonemin

The first total synthesis of the dimeric alkaloid pigment scytonemin is described. The key transformations in its synthesis from 3-indole acetic acid are a Heck carbocyclization and a Suzuki-Miyaura cross-coupling, orchestrated in a stereospecific tandem fashion, followed by a biosynthetically inspired oxidative dimerization. The tandem sequence generates a tetracyclic (E)-3-(arylidene)-3,4-dihydrocyclopenta[b]indol-2(1H)-one that is subsequently dimerized into the unique homodimeric core structure of scytonemin.

A new multifunctional platform based on high aspect ratio interdigitated NEMS structures

A multifunctional NEMS platform based on a mass-producible, surface relief grating has been developed and fabricated directly in polymer materials. The pattern consists of high aspect ratio interdigitated nanometer-sized pairs of walls and can be produced in a low-complexity one-step patterning process with nanoimprint lithography. In this paper, we demonstrate the usefulness of the platform primarily by showing an application as a high-sensitivity mass sensor in air. The sensors, which are based on the high frequency resonant response of around 200 MHz, show a mass responsivity of the order of 0.1 Hz/zg per wall at room temperature and in ambient air. Their ability to selectively adsorb airborne target molecules, such as thiols, is also demonstrated. We also show that the same device can function as a varactor for electronic circuits based on its large tunable capacitive range.

Patterns of mutations in target genes in septicemia isolates of Escherichia coli and Klebsiella pneumoniae with resistance or reduced susceptibility to ciprofloxacin

Thirty-two Escherichia coli and 21 Klebsiella pneumoniae septicemia isolates with varying degrees of resistance to ciprofloxacin were analyzed for the presence of point mutations within the quinolone-resistance target genes. The number of mutations observed in the resistant isolates agreed with the level of ciprofloxacin resistance in both species. Such isolates were also resistant to nalidixic acid. Isolates with borderline susceptibility to ciprofloxacin, on the other hand, behaved differently in the two species. In E. coli all the isolates harbored at least one mutation and these isolates were also resistant to nalidixic acid, while no mutations were detected in the K. pneumoniae isolates, and susceptibility to nalidixic acid was unpredictable. Therefore, nalidixic acid cannot be used as a class representative. Time-kill curve studies on an isolate with borderline susceptibility from each species showed higher degrees of resistance to ciprofloxacin in comparison to that of the wild-type E. coli. A previously unreported parC mutation, S57-->T, was detected in a resistant E. coli isolate and might expand the QRDR of this gene. Normalized resistance interpretations of histograms confirmed the setting of microbiological zone breakpoints for ciprofloxacin testing.

Relationship between depressive symptomatology and the subcortical brain syndrome in dementia

OBJECTIVES

the aim of the present study was to elucidate a possible relationship between depressive symptomatology and regional brain symptomatology in demented patients.

METHODS

170 consecutive inpatients were studied. They suffered from Alzheimer's disease (103 patients), vascular dementia (48 patients), or frontotemporal dementia (19 patients). The patients underwent a neuropsychiatric investigation, which included assessments of (1) depression, and (2) regional brain symptomatology. Depressive symptomatology was assessed as presence of (a) depressed mood, and (b) anxiety. In the further statistical analysis, the presence of depressed mood and/or anxiety was also evaluated. The principle of the regional symptom analysis was the successive aggregation of observable symptom variables, leading to the final determination of four possible regional brain syndromes (frontal, subcortical, parietal and global), by way of the Stepwise comparative status analysis (STEP). The possible correlations between regional brain symptomatology and depressive symptomatology were analysed by means of (a) chi(2) statistics, and (b) a logistic regression analysis in which confounding factors were included (age, degree of dementia, duration).

RESULTS

the subcortical syndrome correlated with depressed mood (chi(2), p = 0.002; logistic regression, p = 0.002). A negative correlation was noted between the parietal syndrome and depressed mood (p = 0.010 and p = 0.013, respectively). No other significant correlations between presence of regional brain syndrome and presence of depressive symptomatology could be seen.

CONCLUSIONS

demented patients with a clinically established subcortical dysfunction appear to be more susceptible to depressive symptomatology. The results of this study also suggest that posterior brain dysfunction in dementia is not correlated with depressive symptomatology.

Tacrine and rate of progression in Alzheimer's disease--relation to ApoE allele genotype

Today, cognitive impairment can be successfully treated with acetylcholine esterase inhibitors (AChE-I) in many, but not all, patients with Alzheimer's disease (AD). To investigate the relation between tacrine treatment, inheritance of ApoE epsilon4 alleles, and rate of progression, the differences in MMSE and CIBIC scores (efficacy parameters) after 6 and 12 months of tacrine (an AChE-I) treatment were investigated in 145 AD patients. Of these, 84 were ApoE epsilon4-positive (ApoE4) and 61 were ApoE epsilon4-negative (ApoE2-3). No differences were found after 6 months of treatment, but after 12 months the CIBIC scores revealed that the ApoE4 patients had declined more than the ApoE2-3 patients (p < 0.05). No differences were found for the last 6 months of treatment. The results primarily suggest a faster rate of decline in the ApoE4 AD compared to the ApoE2-3, but may also reflect that ApoE epsilon4 genotype inheritance is a negative predictor of treatment effect of tacrine in AD patients.

Fusidic acid disk diffusion testing of clostridium difficile can be calibrated using single-strain regression analysis

Single-strain regression analysis (SRA) was employed to calibrate the disk diffusion antibiotic susceptibility test for fusidic acid and Clostridium difficile. MIC determinations of 40 clinical isolates of C. difficile were performed with the E-test. The disk diffusion test was standardized according to the Swedish Reference Group for Antibiotics (SRGA). Disks used for SRA contained 1.5, 5, 15, 50 and 150 microg fusidic acid and the routine disk contained 50 microg fusidic acid. A control strain, ATCC 9689, was also tested. SRA constants A and B of the regression lines were calculated. This permitted the determination of zone breakpoints for C. difficile. When applying the pharmacological MIC S and R limits set by SRGA to the E-test results I strain of C. difficile was interpreted as resistant. Zone breakpoints corresponding to the pharmacological MIC limits and calculated using the mean SRA constants for the 40 clinical isolates lead to all strains being interpreted as susceptible. SRA calculations enable laboratories to set up calibrated disk tests with species-related and laboratory-specific interpretations.

Wastewater sludge as a resource: sludge disposal strategies and corresponding treatment technologies aimed at sustainable handling of wastewater sludge

The paper discusses different strategies for the disposal of wastewater sludge, particularly the "use on land" strategy and the "productification" strategy. In the "use on land" strategy the new regulations in Europe call for stabilization as well as disinfection of sludge to be used on land. The paper discusses the design and operation experiences with stabilization/disinfection methods in Norway where such treatment has been compulsory since 1995. In the "productification" strategy it is differentiated between the production of "bio-soils" and production of specific products (energy, nutrients, coagulants etc) and the "marketability" of these products is evaluated. An example of a sludge treatment concept aimed at recycling--the KREPRO process--is presented.

Treatment of Alzheimer's disease with clioquinol

As heavy metal ions may be implicated in the formation of senile plaques in Alzheimer-afflicted brains, treatment with clioquinol was tested in 20 patients with Alzheimer's disease. Clioquinol is a chelator that crosses the blood-brain barrier and has greater affinity for zinc and copper ions than for calcium and magnesium ions. Treatment was given for 21 days at doses of 20 mg/day to 10 patients and 80 mg/day to another 10 patients. The study was blind to the dosages but included no controls. Cerebrospinal fluid (CSF) investigations revealed a significant increase at day 7 and a decrease at day 21 in Tau protein and growth-associated protein (GAP43). These proteins are increased in Alzheimer's disease and considered as rather stable markers. The initial increase may indicate a temporary cytotoxicity to the brain and/or an increased release into the CSF from stores in the tissue, possibly from senile plaques where the proteins are accumulated. The levels of CSF-Tau protein correlated positively and significantly with the serum levels of copper and also with the serum copper/zinc ratio. Clinical ratings showed slight improvement after 3 weeks treatment with clioquinol in this open study.

Fluconazole and voriconazole multidisk testing of Candida species for disk test calibration and MIC estimation

Fluconazole and voriconazole MICs were determined for 114 clinical Candida isolates, including isolates of Candida albicans, Candida glabrata, Candida krusei, Candida lusitaniae, Candida parapsilosis, and Candida tropicalis. All strains were susceptible to voriconazole, and most strains were also susceptible to fluconazole, with the exception of C. glabrata and C. krusei, the latter being fully fluconazole resistant. Single-strain regression analysis (SRA) was applied to 54 strains, including American Type Culture Collection reference strains. The regression lines obtained were markedly different for the different Candida species. Using an MIC limit of susceptibility to fluconazole of < or =8 microg/ml, according to NCCLS standards, the zone breakpoint for susceptibility for the 25-microg fluconazole disk was calculated to be > or =18 mm for C. albicans and > or =22 mm for C. glabrata and C. krusei. SRA results for voriconazole were used to estimate an optimal disk content according to rational criteria. A 5-microg disk content of voriconazole gave measurable zones for a tentative resistance limit of 4 microg/ml, whereas a 2.5-microg disk gave zones at the same MIC level for only three of the species. A novel SRA modification, multidisk testing, was also applied to the two major species, C. albicans and C. glabrata, and the MIC estimates were compared with the true MICs for the isolates. There was a significant correlation between the two measurements. Our results show that disk diffusion methods might be useful for azole testing of Candida isolates. The method can be calibrated using SRA. Multidisk testing gives direct estimations of the MICs for the isolates.

Reduction of the synaptic protein rab3a in the thalamus and connecting brain regions in post-mortem schizophrenic brains

Although the psychotic symptoms in schizophrenia can be alleviated by treatment with dopaminergic receptor antagonists, the etiology and underlying neurochemical pathology remains obscure. Both neuropathological and magnetic resonance imaging studies have found evidence for neuronal loss and atrophy in the thalamus in schizophrenia, implicating this key structure for gating information to cortical areas in the pathophysiology. Recent studies have also found evidence of synaptic loss in the thalamus in schizophrenia. To further examine possible synaptic disturbances, we studied the synaptic related protein rab3a as a marker for synaptic density, using both quantitative Western blotting and immunohistochemistry. The material consisted of brains from 22 schizophrenic patients (mean age 79.3 years), and 24 control subjects (74.8 years). Reduced rab3a protein levels were found in the left thalamus in schizophrenia (0.47 +/- 0.17 vs. 1.00 +/- 0.18; p < 0.0001), while a less marked decrease was found also in the right thalamus (0.75 +/- 0.13 vs. 1.00 +/- 0.09; p < 0.0001). Immunohistochemistry, performed on two schizophrenic and two control brains, revealed that rab3a immunoreactivity was most reduced in the left anterior and mediodorsal thalamic nuclei. Therefore, we extended the study to brain regions connected these thalamic nuclei. Reduced rab3a protein levels were found schizophrenia also in the frontal cortex, hippocampus, gyrus cinguli, and parietal cortex, while no significant differences were found in the temporal cortex, or in cerebellum. The reduction in rab3a was not found to be secondary to confounding factors such as age-differences, post-mortem delay time, generalized brain atrophy, or antipsychotic medication. Therefore, the reduction of rab3a probably reflects synaptic disturbances, possibly synaptic loss, in the limbic system and neocortical areas, in schizophrenia. This part of the brain is known to be involved in behavioral and emotional control, and thus to be crucial for higher mental functions, suggesting that synaptic disturbances in the limbic system may be of importance in the development of psychotic symptoms in schizophrenia.

[Depression and anxiety in the elderly still underdiagnosed. SSRI preparations in conjunction with psychotherapy provide effective treatment]

Depression and anxiety disorders in the elderly are common and under-diagnosed. As depressed elderly people often present with more somatic than psychiatric symptoms, diagnosis is difficult for the general practitioner. The Geriatric Depression Scale can be used as a screening instrument for diagnosis in the elderly. The etiology of depression and anxiety disorders is multifactorial. Important risk factors are psychological stress, reduced absorption of essential nutrients such as folacin and vitamin B12, and biological changes in the brain associated with aging. Selective serotonin reuptake inhibitors (SSRIs) are the drugs of choice in the treatment of elderly people with depression and anxiety disorders. Currently, the most widely used SSRI is citalopram, which according to controlled trials has an effect not only on depressed mood but also on anxiety. The use of SSRIs combined with support and psychotherapy elicits a positive response in nearly 90% of elderly patients. In Sweden, the use of antidepressants is currently most common in the age group 75-80 years, expressed in DDD (defined daily doses/1,000 inhabitants). This indicates a fairly active treatment of the elderly in Sweden.

Hyperactivity in the hypothalamic-pituitary-adrenal axis in demented patients with delirium

Occurrence of delirium is known to be related to, among other things, organic brain disorder, somatic disease and old age. It has been hypothesized that delirium is also associated with stress. Disturbances of the hypothalamic-pituitary-adrenal (HPA) system have been found in delirious patients in various studies. The aim of the present study was to determine the activity in the HPA axis in demented patients to ascertain whether the stress regulating system was more disturbed in patients with delirium than in those without delirium. Demented inpatients with no acute medical illness were included in the study. Basal cortisol levels in serum were measured and dexamethasone suppression test (DST) was performed. The most important finding of the study was a strong relationship between delirium and DST pathology irrespective of age and severity of dementia. It is suggested that certain demented individuals have an impaired HPA system and a low delirium threshold and respond to stress with delirium.

Antibiotic medication and bacterial resistance to antibiotics: a survey of children in a Vietnamese community

OBJECTIVE

To investigate antibiotic use and antibiotic susceptibility of respiratory tract pathogens in children aged 1-5 years in Bavi, Vietnam.

METHOD

Nasopharynx and throat specimens were collected from 200 children from randomly selected households in a demographically defined population. Respiratory isolates were tested for antibiotic susceptibility according to the standard disk diffusion method. A questionnaire survey of carers elicited information on type of antibiotic used, duration of treatment, where the antibiotics had been purchased, type of treatment information retained by carers and episodes of illness preceding the study.

RESULTS

82% of the children had at least one symptom of acute respiratory tract infection (ARI) in the 4 weeks prior to the study, and of these 91% were treated with antibiotics. The most commonly used antibiotics were ampicillin (74%), penicillin (12%), amoxicillin (11%), erythromycin (5%), tetracycline (4%) and streptomycin (2%). Ampicillin was used for 3.3 days on average (SD:1.8) and penicillin for 2.6 days (SD:0.7). When deciding which antibiotic to use, 67% of the carers consulted the pharmacy seller, 11% decided themselves and 22% followed the doctor's prescription. The carrier rate of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis was 50%, 39% and 17%, respectively. Isolates from 145 children were susceptibility tested, and 74% were found to carry resistant pathogens. Of the tested isolates, 90% of S. pneumoniae, 68% of H. influenzae and 74% of M. catarrhalis were resistant to at least one antibiotic. The mean number of antibiotics (susceptible strains excluded) to which resistance was found was 2.0 (SD:1.2), 2.5 (SD:1.8) and 2.1 (SD:0.9), respectively. S. pneumoniae and H. influenzae showed high resistance to tetracycline (88% and 32%, respectively), trimethoprim/sulphonamide (32% and 44%), and chloramphenicol (25% and 24%). 23% of S. pneumoniae were erythromycin-resistant and 18% of H. influenzae isolates were resistant to ampicillin. There was a significant difference in ampicillin and penicillin resistance between the group of children previously treated with beta lactam antibiotics and the group of children who did not receive antibiotics.

CONCLUSION

As reported by the carers, children in Bavi are treated with antibiotics frequently. Most antibiotics were obtained without consulting a doctor. High levels of antibiotic resistance and high prevalence of multidrug-resistant strains were found among respiratory pathogens. The existence of a large reservoir of resistance genes among children in low-income countries represents a threat to the success of antibiotic therapy throughout the world. Multi-faceted programmes to improve rational use of antibiotics in Vietnam are urgently needed.

[Inventory of geriatric psychiatry in Sweden. In short supply where demand does not determine resource allocation]

In 1999 The Swedish Society for Old Age Psychiatry conducted an investigation in all Swedish counties in order to survey existing organizations and resources for medical services intended for elderly people with psychiatric complaints. In some counties there were no out-patient units specifically aimed at elderly people with psychiatric diseases, while more than half had no out-patient units for the large group of elderly with psychiatric ailments other than dementia. The total number of beds was far less than international recommendations. Less than 5 per cent of the total number of Swedish psychiatrists and geriatricians hold positions exclusively for geriatric psychiatry. Access to geriatric psychiatry resources appears to be unevenly distributed, and may be found mainly in or near university cities.