bluuebunny/crossref_metadata_2025 huggingface dataset:
Using Pooled Kappa to Summarize Interrater Agreement across Many Items
Authors: De Vries Han , Elliott Marc N. , Kanouse David E. , Teleki Stephanie S.
Published: April 2008

We propose the pooled estimator of kappa, an efficient estimator when summarizing the interrater agreement for qualitative data with many items but few subjects. We evaluate this estimator through a simulation of proposed and alternative (average kappa) estimators and subsequently apply our method to calculate pooled and average kappas over 2,176 rated items from six semistructured interviews with sponsors of the CAHPS. The proposed pooled kappa estimator efficiently summarizes interrater agreement by domain. It is more widely applicable and makes better use of scarce subjects than simply averaging item-level kappas.
A Response to Wang and Swanson's Article on National HRD and Theory Development
Authors: McLean Gary N. , Lynham Susan A. , Azevedo Ross E. , Lawrence John E.S. , Nafukho Fredrick M.
Published: April 2008

Wang and Swanson (2008) have provided a critique of the current state of the research and theory of national human resource development (NHRD). In this article, the authors provide a critique based on the following issues: insistence on a single paradigm of truth or reality, theory development methodology, the bounding process, the definitional process, scope of NHRD efforts, and reliance on economics (and only development economics).
Making Computer Games and Design Thinking
Authors: Hayes Elisabeth R. , Games Ivan Alex
Published: April 2008

This article provides an overview of computer software and instructional strategies intended to engage young people in making computer games, to achieve a variety of educational goals. It briefly describes the most popular of such programs and compares their key features, including the kinds of games that can be created with the software, the types of communities and resources that are associated with each program, claims made for learning outcomes resulting from use of the software, and the results of empirical research (if any) on the application and outcomes of the software in formal or informal educational settings. A key finding is that existing software and educational applications stress the goal of teaching users about computer programming and place little or no emphasis on teaching concepts related to game design. It concludes by discussing the potential value of explicit attention to “design thinking” as goal of game making in education.
Effect of combined application of electromagnetic fields on horizontal direct chill casting of 7050 aluminium alloy
Authors: Zhu Q. F. , Zhao Z. H. , Cui J. Z. , Zuo Y. B. , Wang X. J.
Published: April 2008

Influence of combined electromagnetic field application on horizontal direct chill casting of 7050 aluminium alloy is investigated. Temperature measurement and structure observation are carried out to analyse the casting process under different electromagnetic fields. Combined electromagnetic field can reduce the harmful gravitational thermal effect in the horizontal direct chill casting process and improve the ingot properties. With application of combined electromagnetic field, temperature distribution in the melt is more uniform, sump of the ingot becomes flat and symmetric, surface quality of ingot improves markedly, grain morphology changes from feathery grains to equiaxed grains and grain size decreases. Distribution of copper and zinc in the transverse section of the ingot becomes more uniform.
Determinants of hospital costs in community-acquired pneumonia
Authors: Reyes S. , Martinez R. , Vallés J. M. , Cases E. , Menendez R.
Published: April 2008

Community-acquired pneumonia (CAP) has a high incidence and involves an important consumption of healthcare resources. The present authors analysed the influence of comorbidity, initial severity and complications upon the direct costs associated with hospitalised CAP patients.

Direct hospitalisation costs (room cost, treatment, laboratory and diagnostic tests) were assessed in a prospective, observational study of 271 patients admitted to a hospital ward due to CAP.

The mean±sdpatient age was 70±15 yrs. The mortality rate was 11.1%. Complications were found in 72.3% and comorbidities in 74.9%. The median (interquartile range) total cost was \#8364;1,683 (\#8364;1,291–2,471) and the component costs were: room cost \#8364;1,286 (\#8364;857–1,714); laboratory tests \#8364;212 (\#8364;171–272); treatment \#8364;187 (\#8364;114–304); and diagnostic procedures \#8364;58 (\#8364;29–122). Complications and higher Pneumonia Severity Index increased the costs, but age and comorbidity did not. A logistic regression analysis to predict high cost (>\#8364;1,683) showed that infectious (odds ratio 6.8, 95% confidence interval 1.3–36), digestive (5.9 (1.5–22.8)), pulmonary (2.6 (1.4–4.7)) and other complications (3.9 (1.8–8.4)) were independent risk factors, as were previous hospitalisation (2.3 (1.2–4.3)) and hypoalbuminaemia (2 (1.1–3.6)).

Complications, hypoalbuminaemia and previous hospitalisation were the main determinants of high direct costs of hospitalisation due to community-acquired pneumonia. Neither age nor comorbidities were independently associated with cost.
Rapid diagnosis of pulmonary TB by BAL enzyme-linked immunospot assay in an immunocompromised host
Authors: Strassburg A. , Jafari C. , Ernst M. , Lotz W. , Lange C.
Published: April 2008

Immunocompromised patients with acid-fast bacilli (AFB) smear-negative active pulmonary tuberculosis (pTB) often present with nonspecific clinical symptoms and findings. T-cell interferon-γ release assays (TIGRA) performed on whole blood (using ELISA) or peripheral blood mononuclear cells (using enzyme-linked immunospot assay (ELISPOT)) are more sensitive for the diagnosis ofMycobacterium tuberculosis(MTB) infection than the tuberculin skin test (TST), but cannot distinguish active from latent MTB infection.

The present authors report a 38-yr-old female presenting with a 3-week history of malaise, dyspnoea, fevers and coughing, who had received immunosuppressive therapies over 8 months for mixed connective tissue disease. Chest radiograph and thoracic computed tomography showed ground glass opacities in both lower lobes. The TST-induration was 0 mm and AFBs or MTB nucleic acid was not detected on sputum and bronchial secretions. However, TIGRAs performed on peripheral blood cells were reactive. A high frequency of MTB-specific T-cells compatible with the immunodiagnosis of active pTB was detected among bronchoalveolar lavage cells using ELISPOT. Antituberculous therapy was initiated 18 days before MTB was discovered on sputum cultures.

Detection ofMycobacterium tuberculosis-specific T-cells in the bronchoalveolar lavage using enzyme-linked immunospot assay is a promising tool for the diagnosis of active pulmonary tuberculosis in immunocompromised patients with negative acid-fast bacilli smears.
Novel tests for diagnosing tuberculous pleural effusion: what works and what does not?
Authors: Trajman A. , Pai M. , Dheda K. , van Zyl Smit R. , Zwerling A. A. , Joshi R. , Kalantri S. , Daley P. , Menzies D.
Published: April 2008

Tuberculous pleuritis is a common manifestation of extrapulmonary tuberculosis and is the most common cause of pleural effusion in many countries. Conventional diagnostic tests, such as microscopic examination of the pleural fluid, biochemical tests, culture of pleural fluid, sputum or pleural tissue, and histopathological examination of pleural tissue, have known limitations. Due to these limitations, newer and more rapid diagnostic tests have been evaluated. In this review, the authors provide an overview of the performance of new diagnostic tests, including markers of specific and nonspecific immune response, nucleic acid amplification and detection, and predictive models based on combinations of markers. Directions for future development and evaluation of novel assays and biomarkers for pleural tuberculosis are also suggested.
Cupin: A candidate molecular structure for the Nep1-like protein family
Authors: Cechin Adelmo L , Sinigaglia Marialva , Lemke Ney , Echeverrigaray Sérgio , Cabrera Odalys G , Pereira Gonçalo AG , Mombach José CM
Published: April 2008

Background

NEP1-like proteins (NLPs) are a novel family of microbial elicitors of plant necrosis. Some NLPs induce a hypersensitive-like response in dicot plants though the basis for this response remains unclear. In addition, the spatial structure and the role of these highly conserved proteins are not known.

Results

We predict a 3d-structure for the β-rich section of the NLPs based on alignments, prediction tools and molecular dynamics. We calculated a consensus sequence from 42 NLPs proteins, predicted its secondary structure and obtained a high quality alignment of this structure and conserved residues with the two Cupin superfamily motifs. The conserved sequence GHRHDWE and several common residues, especially some conserved histidines, in NLPs match closely the two cupin motifs. Besides other common residues shared by dicot Auxin-Binding Proteins (ABPs) and NLPs, an additional conserved histidine found in all dicot ABPs was also found in all NLPs at the same position.

Conclusion

We propose that the necrosis inducing protein class belongs to the Cupin superfamily. Based on the 3d-structure, we are proposing some possible functions for the NLPs.
PCR-based gene synthesis to produce recombinant proteins for crystallization
Authors: Marsic Damien , Hughes Ronny C , Byrne-Steele Miranda L , Ng Joseph D
Published: April 2008

Background

Gene synthesis technologies are an important tool for structural biology projects, allowing increased protein expression through codon optimization and facilitating sequence alterations. Existing methods, however, can be complex and not always reproducible, prompting researchers to use commercial suppliers rather than synthesize genes themselves.

Results

A PCR-based gene synthesis method, referred to as SeqTBIO, is described to efficiently assemble the coding regions of two novel hyperthermophilic proteins, PAZ (Piwi/Argonaute/Zwille) domain, a siRNA-binding domain of an Argonaute protein homologue and a deletion mutant of a family A DNA polymerase (PolA). The gene synthesis procedure is based on sequential assembly such that homogeneous DNA products can be obtained after each synthesis step without extensive manipulation or purification requirements. Coupling the gene synthesis procedure to in vivo homologous recombination techniques allows efficient subcloning and site-directed mutagenesis for error correction. The recombinant proteins of PAZ and PolA were subsequently overexpressed in E. coli and used for protein crystallization. Crystals of both proteins were obtained and they were suitable for X-ray analysis.

Conclusion

We demonstrate, by using PAZ and PolA as examples, the feasibility of integrating the gene synthesis, error correction and subcloning techniques into a non-automated gene to crystal pipeline such that genes can be designed, synthesized and implemented for recombinant expression and protein crystallization.
Awareness of the need for safe storage of Methadone at home is not improved by the use of protocols on recording information giving
Authors: Mullin Annemarie , McAuley Rosanna J , Watts Derrett J , Crome Ilana B , Bloor Roger N
Published: April 2008

Background

Methadone is a synthetic, narcotic analgesic used in the treatment of drug misuse. Tragedies involving children being poisoned by the accidental ingestion of methadone are no longer a rare occurrence. Following an audit of the effectiveness of the provision and recall of information to patients attending an NHS Methadone Clinic a protocol was introduced to ensure that staff documented the provision of such information and patients gave a written confirmation that they had received the information.

Methods

The study was undertaken in the setting of an NHS methadone clinic with the aim of re- auditing the storage of methadone at home following the introduction of the new protocols. 174 patients completed an anonymous questionnaire regarding where they store methadone at home and whether they recall being given advice about safe storage. Community pharmacists were contacted by telephone to assess the level of advice given to methadone patients regarding safety.

Results

Only 49 (28.2%) patients recalled being given advice about safe storage, 24 (13.8%) recalled that information was provided by clinic staff. 170 (97.7%) patients regard methadone as being dangerous. (28.2%). Methadone is most commonly stored in a cupboard (37.9%). All methadone is dispensed in a bottle with a child resistant cap on it. All patients reported they stored their methadone in the original bottle provided by the pharmacist.

Conclusion

Recall of information on safety issues is very poor. Provision of written as well as verbal information is needed. The use of printed safety information cards which patients can take away for future reference may be of use. It is the responsibility of health professionals to ensure they provide information and advice to methadone users on the safe storage of their methadone at home.
Genetic diversity and silencing suppression effects of Rice yellow mottle virus and the P1 protein
Authors: Siré Christelle , Bangratz-Reyser Martine , Fargette Denis , Brugidou Christophe
Published: April 2008

Background

PTGS (post-transcriptional gene silencing) is used to counter pathogenic invasions, particularly viruses. In return, many plant viruses produce proteins which suppress silencing directed against their RNA. The diversity of silencing suppression at the species level in natural hosts is unknown.

Results

We investigated the functional diversity of silencing suppression among isolates of the African RYMV (Rice yellow mottle virus) in rice. The RYMV-P1 protein is responsible for cell-to-cell movement and is a silencing suppressor. Transgenic gus-silencing rice lines were used to investigate intra-specific and serogroup silencing suppression diversity at two different levels: that of the virion and the P1 silencing suppressor protein. Our data provide evidence that silencing suppression is a universal phenomenon for RYMV species. However, we found considerable diversity in their ability to suppress silencing which was not linked to RYMV phylogeny, or pathogenicity. At the level of the silencing suppressor P1 alone, we found similar results to those previously found at the virion level. In addition, we showed that cell-to-cell movement of P1 was crucial for the efficiency of silencing suppression. Mutagenesis of P1 demonstrated a strong link between some amino acids and silencing suppression features with, one on the hand, the conserved amino acids C95 and C64 involved in cell-to-cell movement and the strength of suppression, respectively, and on the other hand, the non conserved F88 was involved in the strength of silencing suppression.

Conclusion

We demonstrated that intra-species diversity of silencing suppression is highly variable and by mutagenesis of P1 we established the first link between silencing suppression and genetic diversity. These results are potentially important for understanding virus-host interactions.
Differential Activation of p38 and Extracellular Signal-Regulated Kinase in Spinal Cord in a Model of Bee Venom-Induced Inflammation and Hyperalgesia
Authors: Cui Xiu-Yu , Dai Yi , Wang Sheng-Lan , Yamanaka Hiroki , Kobayashi Kimiko , Obata Koichi , Chen Jun , Noguchi Koichi
Published: April 2008

Background:

Honeybee's sting on human skin can induce ongoing pain, hyperalgesia and inflammation. Injection of bee venom (BV) into the intraplantar surface of the rat hindpaw induces an early onset of spontaneous pain followed by a lasting thermal and mechanical hypersensitivity in the affected paw. The underlying mechanisms of BV-induced thermal and mechanical hypersensitivity are, however, poorly understood. In the present study, we investigated the role of mitogen-activated protein kinase (MAPK) in the generation of BV-induced pain hypersensitivity.

Results:

We found that BV injection resulted in a quick activation of p38, predominantly in the L4/L5 spinal dorsal horn ipsilateral to the inflammation from 1 hr to 7 d post-injection. Phosphorylated p38 (p-p38) was expressed in both neurons and microglia, but not in astrocytes. Intrathecal administration of the p38 inhibitor, SB203580, prevented BV-induced thermal hypersensitivity from 1 hr to 3 d, but had no effect on mechanical hypersensitivity. Activated ERK1/2 was observed exclusively in neurons in the L4/L5 dorsal horn from 2 min to 1 d, peaking at 2 min after BV injection. Intrathecal administration of the MEK inhibitor, U0126, prevented both mechanical and thermal hypersensitivity from 1 hr to 2 d. p-ERK1/2 and p-p38 were expressed in neurons in distinct regions of the L4/L5 dorsal horn; p-ERK1/2 was mainly in lamina I, while p-p38 was mainly in lamina II of the dorsal horn.

Conclusion:

The results indicate that differential activation of p38 and ERK1/2 in the dorsal horn may contribute to the generation and development of BV-induced pain hypersensitivity by different mechanisms.
Medical history-taking in psychiatry
Authors: Phelan Michael , Blair Grant
Published: April 2008

A good medical history is an essential starting point in ensuring that the
physical health needs of people with severe mental illness are addressed.
Psychiatrists have an important role in helping to tackle the general ill
health, excess of undiagnosed physical illness and reduced survival rates
among their patients. To do this they need to use their medical training,
communication skills and regular contact with patients. Assessments should
include family history, past and current physical health, medication,
lifestyle, healthcare and physical symptoms. Some groups of patients will
need more detailed assessments.
Mentalisation and metaphor in poetry and
psychotherapy
Authors: Holmes Jeremy
Published: April 2008

People turn to poetry and to psychotherapy when in states of heightened
emotion – love, elation, despair, death and loss. Through the analysis of a
particular poem this article suggests that there are formal similarities
between poetry and psychotherapy that can illuminate the workings of the
latter. Perhaps the most overarching of these is mentalisation: the capacity
to ‘think about feelings’ or to be ‘mind-minded’. Finding the ‘right words
in the right order’ is a task for therapists and their patients as well as
for poets, since the appropriate image or metaphor can mirror or evoke
feelings in the listener in a way that facilitates empathic attunement. If
feelings can be objectified, their power to distress or overwhelm is
mitigated. Thus, poetry and psychotherapy are similarly concerned with
processes of repair of the human experiential and communicative fabric.
Detained – what's my choice? Part 2: Conclusions and
recommendations
Authors: Dorkins Eluned , Roberts Glenn , Wooldridge James , Hewis Elaine
Published: April 2008

We have developed this succession of articles as a series of iterative
steps, each seeking to uphold the recovery values of co-working and
collaboration, looking for agreement and commonality but valuing equally
diverse viewpoints and difference. Our conclusion is that this is the
beginning of a creative dialogue on choice as a route to recovery for people
who are psychiatrically detained. We commend our method of engaging with the
inevitable tensions and dilemmas by: clarifying the story behind difficult
interactions, identifying the relevant guiding principles and jointly
working to explore from different viewpoints what can be done to promote
recovery.
Effects of timing and duration of gestational exposure to serotonin reuptake inhibitor antidepressants: Population-based study
Authors: Oberlander Tim F. , Warburton William , Misri Shaila , Aghajanian Jaafar , Hertzman Clyde
Published: April 2008

Background

Late-gestational serotonin reuptake inhibitor (SRI) exposure has been linked to adverse neonatal outcomes; however, the impact of timing and duration of exposure is unknown.

Aims

To determine whether late-gestational exposure to an SRI is associated with increased risk of adverse neonatal outcome relative to early exposure.

Method

Population-based maternal and neonatal health records were linked to prenatal maternal prescription records for an SRI medication (n=3500).

Results

After controlling for maternal illness and duration of exposure, using propensity score matching, neonatal outcomes did not differ between late and early exposure (PIQ>0.05). After controlling for maternal illness, longer prenatal exposure increased the risks of lower birth weight, respiratory distress and reduced gestational age (P<0.05).

Conclusions

Using population health data, length of gestational SRI exposure, rather than timing, increased the risk for neonatal respiratory distress, lower birth weight and reduced gestational age, even when controlling for maternal illness and medication dose. These findings highlight the importance of distinguishing the specific impact of medication exposure from exposure to maternal illness itself.
Medical disorders in people with recurrent
depression
Authors: Farmer Anne , Korszun Ania , Owen Michael J. , Craddock Nick , Jones Lisa , Jones Ian , Gray Jo , Williamson Richard J. , McGuffin Peter
Published: April 2008

Background

Few studies have examined the rates of physical disorders in those with
recurrent depression.

Aims

To examine self-reported physical disorders in people with recurrent
depression compared with a psychiatrically healthy control group.

Method

As part of a genetic case-control association study, 1546 participants
with recurrent depression and 884 controls were interviewed about
lifetime ever treatment for 16 different physical health disorders.

Results

The cases group had a significantly higher frequency of 14 physical
disorders and more obesity than the control group. After controlling for
age, gender, body mass index (BMI) and multiple testing, those in the
cases group had significantly higher rates of gastric ulcer, rhinitis/hay
fever, osteoarthritis, thyroid disease, hypertension and asthma.

Conclusions

People with recurrent depression show high rates of many common physical
disorders. Although this can be partly explained by BMI, shared
aetiological pathways such as dysfunction of the hypothalamic–pituitary
axis may have a role.
Invited commentary on … Proposals for massive expansion of
psychological therapies would be counterproductive across
society
Authors: King Michael
Published: April 2008

Will an expansion of access to cognitive-behavioural therapy lead to greater
happiness? Summerfield and Veale debate this question by focusing on the
nature of mental distress and the best evidence for ameliorating it.
Stimulating though it is, their debate left me wondering about the wider
philosophical and ethical implications behind our rush to therapy.
Building capacity for leadership and teamwork: developing, delivering and evaluating an experiential group relations conference
Authors: Bryson Sandy , Asher Carolyn J.
Published: April 2008

Aim and Methods

Specialist registrars in psychotherapy, at various stages of their training, attended a 1-day experiential group relations conference. The aim was to provide a training context in which trainees could reflect, through direct experience, on their capacity for leadership and teamwork, and the difficulties in taking up one's own authority in role.

Results

Participants rated (on a 5-point Likert scale) the various structured elements of the conference as being greater than moderately useful for their learning. At 9-month follow-up, median scores were 4, indicating that the conference had a moderate to high impact on the participants' learning in four key dimensions: effective communication, taking up a leadership role, dealing with task-and role-related anxiety, and containing others' psychological projections.

Clinical Implications

There is often little time to reflect on one's experiences or behaviour in professional environment. The study demonstrates that learning about one's behaviour, capacity for leadership, performing various roles and the ability to act with authority, in a facilitated experiential learning environment can make a significant contribution to the development of future consultant psychiatrists in psychotherapy. In the light of the new curriculum (Royal College of Psychiatrists, 2006), this training model may facilitate the achievement of core and general competencies for all trainee psychiatrists.
Immunological Detection of Nω‐(Carboxymethyl)arginine by a Specific Antibody
Authors: Mera Katsumi , Fujiwara Yukio , Otagiri Masaki , Sakata Noriyuki , Nagai Ryoji
Published: April 2008

N
ω‐(carboxymethyl)arginine (CMA) is an acid‐labile advanced glycation end product (AGE) that was discovered in enzymatic hydrolysate of glycated collagen. Subsequently, CMA was also detected in human serum, and its level in patients with diabetes was found to be higher than in people without the disease. However, the histological localization of CMA and its pathophysiological significance remains poorly understood. Here, to address this issue, we developed a monoclonal antibody specific for CMA. This antibody reacted with CMA and CMA‐protein adduct, whereas it did not cross‐react with its analogues, such as Nɛ‐(carboxymethyl)lysine and S‐(carboxymethyl)cysteine, indicating that the antibody specifically recognizes CMA. Upon immunohistochemical analysis, a significant CMA immnoreactivity was found in atherosclerotic lesions, whereas no such immunoreactivity was observed in normal regions. This suggests that the accumulation of CMA in tissue proteins may contribute to the pathophysiologies associated with aging and age‐related diseases.
Usefulness of Antibodies for Evaluating the Biological Significance of AGEs
Authors: Nagai Ryoji , Fujiwara Yukio , Mera Katsumi , Motomura Keita , Iwao Yasunori , Tsurushima Keiichiro , Nagai Mime , Takeo Kazuhiro , Yoshitomi Makiko , Otagiri Masaki , Ikeda Tsuyoshi
Published: April 2008

Polyclonal and monoclonal antibodies have been widely applied to demonstrate the presence of advanced glycation end products (AGEs) in vivo. However, our previous study showed that monoclonal anti‐AGE antibody (6D12) and polyclonal anti‐Nɛ‐(carboxymethyl)lysine (CML) antibody recognize not only CML but also Nɛ‐(carboxyethyl)lysine (CEL), thus indicating that we should pay attention to the specificity of the antibodies. As a result, we prepared specific monoclonal antibodies against CML, CEL, Nω‐(carboxymethyl)arginine (CMA), and S‐(carboxymethyl)cysteine (CMC). Our immunochemical study using anti‐CMA antibody demonstrated that the CMA content increased in a time‐dependent manner when collagen was incubated with glucose, indicating that immunological quantification using the specific antibody is especially useful for measuring an acid‐labile AGE structure, such as CMA. Monoclonal antibody is also applied to identify a novel biological marker in pathological lesions. We prepared antibody libraries against proteins modified with aldehydes, such as glyoxal, methylglyoxal, and glycolaldehyde (GA), and one antibody, GA5, which specifically reacts with the GA‐modified protein that is recognized in human atherosclerotic lesions. Following successive high‐performance liquid chromatography purification, the GA5‐reactive compound was isolated and its chemical structure was found to be 3‐hydroxy‐4‐hydroxymethyl‐1‐(5‐amino‐5‐carboxypentyl) pyridinium cation, which was named GA‐pyridine. Taken together, these results demonstrate that a specific antibody is a powerful tool for analyzing novel biomarkers, formation pathways, and the efficacy of AGE inhibitors.
Comparison of Pharmacokinetics between Highly and Mildly Modified AGE Proteins in Mice
Authors: Nagai Ryoji , Mera Katsumi , Fujiwara Yukio , Nagai Mime , Otagiri Masaki
Published: April 2008

We previously demonstrated that RAW 264.7 cells (murine macrophage cell line) recognize highly modified advanced glycation end products (AGE)‐bovine serum albumin (BSA) (high‐AGE‐BSA), which was prepared by incubating BSA with 1600 mmol/L glucose for 40 weeks. In the present study, we prepared mildly modified AGE‐BSA (mild‐AGE‐BSA) and conducted an endocytic uptake study using human monocyte‐derived macrophages and Chinese hamster ovary cells which overexpressed such scavenger receptors as CD36, SR‐BI (scavenger receptor class B type‐I), and LOX‐1 (lectin‐like oxidized low‐density lipoprotein receptor‐1). Although high‐AGE‐BSA was significantly recognized by these cells, mild‐AGE‐BSA did not show any ligand activity to these cells. Furthermore, when 111In‐labeled mild‐ or high‐AGE‐BSA was injected into the tail vein of male ddY mice, 111In‐high‐AGE‐BSA was rapidly cleared from the circulation, with about 80% of the injected 111In‐high‐AGE‐BSA being eliminated within 5 min. In contrast, the clearance rate of 111In‐mild‐AGE‐BSA was very slow, similar to the 111In‐native BSA. Taken together, our results indicate that the ligand activity of AGE‐BSA to scavenger receptors and those pharmacokinetic properties depend on their rate of modification by AGEs.
Kinetic Study of the Reaction of Glycolaldehyde with Two Glycation Target Models
Authors: Adrover Miquel , Vilanova Bartolomé , Muñoz Francisco , Donoso Josefa
Published: April 2008

We have studied the reactivity of glycolaldehyde (GLA) with N‐acetyl‐Cys and N‐acetyl‐Phe‐Lys at physiological conditions of pH and temperature. The reaction between the N‐Ac‐Phe‐Lys and GLA was studied in the presence of NaCNBH3 and then by using high‐performance liquid chromatography (HPLC)‐UV/Vis. The reaction between N‐Ac‐Cys and GLA was followed by stopped‐flow spectroscopy with UV/Vis detection. Both the reduced Schiff base and thiohemiacetal were identified by 1H‐NMR and HPLC‐mass spectrometry detection. The kinetic rate constant for the thiohemiacetal formation is four orders of magnitude higher than that for the Schiff base formation. This result suggests that the thiol group represents the most important target in protein glycation.
Formation Mechanisms of Melanoidins and Fluorescent Pyridinium Compounds as Advanced Glycation End Products
Authors: Hayase Fumitaka , Usui Teruyuki , Ono Yoriyuki , Shirahashi Yoshinobu , Machida Tomomi , Ito Takashi , Nishitani Nozomu , Shimohira Kazuhito , Watanabe Hirohito
Published: April 2008

The formation mechanisms of melanoidins as advanced glycation end products (AGEs) have not been resolved. Blue and red pigments generated in the D‐xylose–glycine reaction system are postulated to be intermediate oligomers in the generation of melanoidins. A novel blue pigment, designated blue‐M5, was identified as a similar structure to blue‐M1 except for the side chain of two dihydroxypropyl groups. Blue pigments were also generated in the D‐glucose–glycine and D‐xylose–β‐alanine reaction systems as well as in the D‐xylose–glycine reaction system. Blue pigments by the Maillard reaction might be formed by the decarboxylation of two molecules of pyrrolopyrrole‐2‐carbaldehydes (PPA). PPA, composed of a side chain of a dihydroxypropyl group, was identified as a precursor of blue pigments. In fact, blue‐M5 was generated by the incubation of PPA alone. Blue pigments, which involved pyrrolopyrrole structures, were readily changed to brown polymers. Glyceraldehyde‐derived pyridinium (GLAP) compound, a glyceraldehyde‐derived fluorescent AGE, and lysyl‐pyrropyridine, a 3‐deoxyglucosone‐derived fluorescent AGE, were detected at higher levels in the plasma proteins and the tail tendon collagen of streptozotocin‐induced diabetic rats compared to normal rats. GLAP and lysyl‐pyrropyridine, therefore, might be related to the progression of diabetic complications.
A419C (E111A) Polymorphism of the Glyoxalase I Gene and Vascular Complications in Chronic Hemodialysis Patients
Authors: Kalousová Marta , Germanová Alexandra , Jáchymová Marie , Mestek Oto , Tesav̌ Vladimír , Zima Tomáš
Published: April 2008

Advanced glycation end products (AGEs) take part in the pathogenesis of vascular, diabetic, and uremic complications. Their precursors are detoxified by the glyoxalase system. Our aim was to study A419C (E111A) single nucleotide polymorphism (SNP) of the glyoxalase I gene in hemodialysis (HD) patients. A419C SNP, several laboratory parameters including soluble receptor for AGEs (sRAGE), and clinical data were studied in 214 HD patients and 89 controls. Allelic and genotypic frequencies did not differ between HD patients and controls. A419C SNP was significantly linked with serum sRAGE, which sensitively reflects the AGE burden of the organism (3986 ± 1638 pg/mL in the CC variant versus 3277 ± 1398 pg/mL in the AC variant and 3297 ± 1445 pg/mL in the AA variant, P < 0.01). In the CC variant, significantly higher prevalence of cardiovascular disease and peripheral vascular disease was found, while the prevalence of hypertension, diabetes mellitus, and dyslipidemia did not differ between genotypes. In summary, in this study we demonstrate for the first time the association of A419C polymorphism of the glyoxalase I gene with sRAGE levels and show the genetic predisposition to vascular complications in HD patients.
N‐terminal Glycation of Proteins and Peptides in Foods andin Vivo
Authors: Penndorf Ilka , Li Changhao , Schwarzenbolz Uwe , Henle Thomas
Published: April 2008

Specific determination of N‐(2‐furoylmethyl)valine (FM‐Val) together with furosine in acid hydrolyzates of human hemoglobin of healthy volunteers (n = 6) and diabetic patients (n = 14) by means of reversed‐phase HPLC with electrospray ionization–time‐of‐flight mass spectroscopy is reported. Whereas FM‐Val is formed during acid hydrolysis of the N‐terminal hemoglobin adduct N‐fructosylvaline, furosine results from acid degradation of lysine residues glycated at the ɛ‐amino group. Quantification was based on the use of synthesized isotopomers, namely N‐[2‐(13C6)furoylmethyl]valine and N‐ɛ‐[2‐(13C6)furoylmethyl]lysine, thus enabling interference‐free detection and calibration. Taking the conversion factors into account, the amount of N‐terminally bound N‐fructosylvaline in human hemoglobin was between 518 and 774 pmol/mg protein for healthy volunteers and between 586 and 1426 pmol/mg protein for diabetic patients. Derivatization at the side chain of peptide‐bound lysine residues to N‐ɛ‐fructosyllysine was from 1156 to 1753 pmol/mg protein for healthy controls and from 1191 to 2409 pmol/mg protein for diabetics. For these patients, the amount of N‐fructosylvaline showed good correlation with the values for HbA1c. The significantly higher relative extent of glycation at the N terminus compared to side‐chain glycation points to a specific and intraindividual capacity for enzymatic deglycation in human erythrocytes, which can be assessed using the proposed method.
Inflammation and the Redox‐sensitive AGE–RAGE Pathway as a Therapeutic Target in Alzheimer's Disease
Authors: Maczurek Annette , Shanmugam Kirubakaran , Münch Gerald
Published: April 2008

Alzheimer's disease (AD) is the most common cause of dementia. Neuritic amyloid plaques and concomitant chronic inflammation are prominent pathological features of AD. β‐amyloid peptide (Aβ), the major component of plaques, and advanced glycation end products (AGEs), post‐translational protein modifications, are key activators of plaque‐associated inflammation. Aβ, AGEs, S100b, and amphoterin bind to the receptor for AGEs (RAGE), which transmits the signal from RAGE via redox‐sensitive pathways to nuclear factor kappa‐B (NF‐κB)‐regulated cytokines. RAGE‐mediated inflammation caused by glial cells and subsequent changes in neuronal glucose metabolism are likely to be important contributors to neurodegeneration in AD. As long as the neuronal damage is reversible, drugs interfering with the Aβ and AGE–RAGE pathways might be interesting novel therapeutics for the treatment of AD.
Pathophysiological Role of the Glyoxalase System in Renal Hypoxic Injury
Authors: Kumagai Takanori , Nangaku Masaomi , Inagi Reiko
Published: April 2008

Methylglyoxal (MG), a reactive dicarbonyl compound mainly produced by metabolic pathways, such as glycolysis, binds to proteins or nucleic acids and forms advanced glycation end products. MG is efficiently metabolized by the glyoxalase system where MG is converted by glyoxalase I (GLO I) to S‐D‐lactoylglutathione. Although the glyoxalase system has been shown to play a pathological role in various diseases, including diabetic complications, its detailed pathophysiological function remains to be elucidated. We are interested in renal hypoxic diseases, but very little information is available regarding the association between the glyoxalase system and renal hypoxic diseases. Therefore, we investigated the biological role of GLO I in renal hypoxic diseases by using the rat ischemia/reperfusion (I/R) injury model. I/R induced the reduction of renal GLO I activity associated with morphological changes and renal dysfunction. Interestingly, the rats that overexpress human GLO I (GLO I Tg rats) showed amelioration of these manifestations in renal I/R (e.g., improvement of the tubulointerstitial injury and renal function). Accumulation of renal MG adducts, carboxyethyllysine, induced by I/R also decreased in GLO I Tg rats compared to wild‐type rats. These results demonstrate that GLO I has renoprotective effects in I/R injury via reduction of protein modification by MG.
Determination ofNɛ‐(Carboxymethyl)lysine in Foods and Related Systems
Authors: Ames Jennifer M.
Published: April 2008

The sensitive and specific determination of advanced glycation end products (AGEs) is of considerable interest because these compounds have been associated with pro‐oxidative and proinflammatory effects in vivo. AGEs form when carbonyl compounds, such as glucose and its oxidation products, glyoxal and methylglyoxal, react with the ɛ‐amino group of lysine and the guanidino group of arginine to give structures including Nɛ‐(carboxymethyl)lysine (CML), Nɛ‐(carboxyethyl)lysine, and hydroimidazolones. CML is frequently used as a marker for AGEs in general. It exists in both the free or peptide‐bound forms. Analysis of CML involves its extraction from the food (including protein hydrolysis to release any peptide‐bound adduct) and determination by immunochemical or instrumental means. Various factors must be considered at each step of the analysis. Extraction, hydrolysis, and sample clean‐up are all less straight forward for food samples, compared to plasma and tissue. The immunochemical and instrumental methods all have their advantages and disadvantages, and no perfect method exists. Currently, different procedures are being used in different laboratories, and there is an urgent need to compare, improve, and validate methods.
Glycation of Plasma Lipoprotein Lipid Membrane and Screening for Lipid Glycation Inhibitor
Authors: Nakagawa Kiyotaka , Ibusuki Daigo , Yamashita Shinji , Miyazawa Teruo
Published: April 2008

We recently reported that phosphatidylethanolamine (PE)‐linked Amadori product (Amadori‐PE) increased abnormally in diabetic plasma. However, the glycation mechanism of human plasma low‐density lipoprotein (LDL) is still unclear. Moreover, lipid glycation inhibitors have yet to be discovered. In this study, we compared the glycation kinetics of LDL lipid and LDL protein in vitro and screened lipid glycation inhibitors. LDL‐PE was converted to Amadori‐PE followed by LDL protein (apoB) glycation. Pyridoxal 5′‐phosphate could easily react with PE before the glucose–PE reaction, and the PE–pyridoxal 5′‐phosphate adduct was detected in human red blood cells. Pyridoxal 5′‐phosphate can be used in diabetes prevention.
Dicarbonyls Stimulate Cellular Protection Systems in Primary Rat Hepatocytes and Show Anti‐inflammatory Properties
Authors: Buetler Timo M. , Latado Hélia , Baumeyer Alexandra , Delatour Thierry
Published: April 2008

Advanced glycation endproducts (AGEs) and their precursor dicarbonyls are generally perceived as having adverse health effects. They are also considered to be initiators and promoters of disease and aging. However, proof for a causal relationship is lacking. On the other hand, it is known that AGEs and melanoidins possess beneficial properties, such as antioxidant and metal‐chelating activities. Furthermore, some AGEs may stimulate the cellular detoxification system, generally known as the phase II drug metabolizing system. We show here that several reactive dicarbonyl intermediates have the capability to stimulate the cellular phase II detoxification systems in both a reporter cell line and primary rat hepatocytes. In addition, we demonstrate that dicarbonyls can attenuate the inflammatory signaling induced by tumor necrosis factor‐α in a reporter cell system.
Post‐Schiff Base Chemistry of the Maillard Reaction
Authors: Chu Fong Lam , Yaylayan Varoujan A.
Published: April 2008

Schiff bases play a critical role, not only in initiating the Maillard reaction, but also in its propagation. Little attention has been paid so far to the ability of these imines to undergo isomerization and thus contribute to the diversity of Maillard reaction products. In this study, imine isomerization through 5‐oxazolidinone formation was explored in a phenylalanine/glyceraldehyde model system, and spectroscopic evidence was provided for its formation by taking advantage of the strong carbonyl absorption band centered at 1784 cm−1. The importance of 5‐oxazolidinone formation lies in its ability to decarboxylate to azomethine ylide and subsequently form two isomeric imines, each capable of producing distinct Maillard products. Evidence for the formation of such ylides was also provided through their ability to undergo 1,3‐dipolar cycloaddition with dipolarophiles.
The Peptide‐catalyzed Maillard Reaction
Authors: Garbe Leif Alexander , Würtz Alexander , Piechotta Christian T. , Tressl Roland
Published: April 2008

The reaction pathways of amino acids and reducing sugars are now fully understood. The focus in the last few years, however, has turned to the reaction of peptides and proteins with reducing sugars. We have investigated the reaction of γ‐aminobutanoic acid, the heptapeptide Nα‐Acetyl‐Lys‐Lys‐β‐Ala‐Lys‐β‐Ala‐Lys‐Gly, and the model protein β‐casein in Maillard reactions with 1‐13C arabinose. Characterization of 13C‐labeled acetic acid and norfuraneol by gas chromatography–mass spectrometry and nuclear magnetic resonance revealed new formation pathways. The results demonstrate significant differences in the labeling pattern of the products depending on the amine used, indicating different formation pathways of acetic acid and norfuraneol.
Maillard Products as Biomarkers in Cancer
Authors: Bachmeier Beatrice E. , Nerlich Andreas G. , Rohrbach Helmut , Schleicher Erwin D. , Friess Ulrich
Published: April 2008

Because tumors exert increased glycolysis rates, a high intracellular carbonyl stress with the formation of Maillard products may evolve. Therefore, we studied the presence of Nɛ‐(carboxymethyl)lysine (CML) modification in breast cancer tissues from 20 patients and found significant cytoplasmatic staining in tumor cells that was independent of the tumor stage, tumor type, and microanatomic localization. Studying breast cancer cell lines, we also found strong cytoplasmatic CML staining that was again independent of their invasive or metastatic behavior. Our results reveal that tumor cells show a strong cytoplasmatic immunoreactivity to CML without evident association with breast carcinoma type, differentiation, tumor stage, or intratumoral localization. We conclude that CML formation is a general tumor cell‐associated process.
Induction of Heat Shock Proteins and the Proteasome System by Casein‐Nɛ‐(Carboxymethyl)lysine and Nɛ‐(Carboxymethyl)lysine in Caco‐2 Cells
Authors: Schmid Karoline , Haslbeck Martin , Buchner Johannes , Somoza Veronika
Published: April 2008

Repeated mild heat shock treatment has been shown to have anti‐aging effects on cellular mechanisms in vitro. Among these, the age‐associated accumulation of advanced glycation end products (AGEs), such as Nɛ‐(carboxymethyl)lysine (CML), has been demonstrated to be effectively prevented in glyoxal‐exposed human skin fibroblasts following mild heat shock treatment. The biochemical mechanism responsible for this inhibition is not yet known. However, the involvement of heat shock proteins (HSPs) and the misfolded proteins degrading the ubiquitin–proteasome system have been hypothesized. As AGE‐modified proteins are likely to be conformationally modified, we investigated whether treatment of human intestinal cells with casein‐linked CML or nonprotein‐linked CML affects the expression of HSPs and the ubiquitin–proteasome system by using matrix‐assisted laser desorption/ionization–time‐of‐flight tandem mass spectroscopy (after protein separation by two‐dimensional gel electrophoresis) and by Western blotting. Compared to nontreated control cells, expression of HSP90, HSP60, HSP70 chaperones, and the proteasome S26 ATPase subunit 2 were significantly upregulated in casein‐CML and in CML‐treated cells. Exposure of Caco‐2 cells to β‐amyloid, a nonglycation product, revealed similar results. In conclusion, the results indicate that CML and casein‐linked CML activate the expression of HSPs as well as the proteasome system, which are involved in the degradation of misfolded and possibly glycated proteins. Whether this mechanism is based on binding to cell surface receptors, such as the receptor for AGE, has to be clarified in future studies.
Aging, Diabetes, and Renal Failure Catalyze the Oxidation of Lysyl Residues to 2‐Aminoadipic Acid in Human Skin Collagen
Authors: Sell David R. , Strauch Christopher M. , Shen Wei , Monnier Vincent M.
Published: April 2008

The ɛ‐amino group of lysyl residues oxidatively deaminates in the presence of α‐dicarbonyl sugars and redox‐active metals forming α‐aminoadipic acid‐δ‐semialdehyde (allysine; Suyama's hypothesis), which can further oxidize into 2‐aminoadipic acid. Here we show that 2‐aminoadipic acid is significantly (P < 0.05) correlated with 6‐hydroxynorleucine, carboxyethyllysine (CEL), and carboxymethyllysine (CML) in human skin collagen. Since CEL and CML can originate from carbohydrate and lipid by oxidative decomposition and α‐dicarbonyl formation, these results provide support for Suyama's hypothesis. Allysine, in turn, is readily converted by oxidation into 2‐aminoadipic acid, which accumulates to high levels in skin (i.e., > 2 nmol/mg collagen).
Advanced Glycation as a Basis for Understanding Retinal Aging and Noninvasive Risk Prediction
Authors: Pawlak Anna M. , Glenn Josephine V. , Beattie James R. , McGarvey John J. , Stitt Alan W.
Published: April 2008

The retina is exquisitely sensitive to age‐related processes, and, in many cases, these can precipitate progressive and profound loss of vision. Many asymptomatic abnormalities that accrue in the outer retina as we get older can serve as a sinister preamble to age‐related macular degeneration (AMD). This condition remains the leading cause of irreversible blindness in industrialized countries, but its precise pathogenesis has yet to be completely elucidated. Over recent years, increasing evidence has suggested that the accumulation of advanced glycation end products (AGEs) and activation of the receptor for AGEs in the outer retina could play a significant role in the initiation and progression of AMD. The current review outlines this evidence and indicates how products of Maillard chemistry could be used as robust markers for outer retinal aging and susceptibility to AMD. The utility of Raman spectroscopy to measure AGE adducts in human tissues is presented. The methodology reinforces the association between AGE formation and retinal aging and provides exciting possibilities for assessing these pathogenic agents in the living eye and, perhaps, for providing a valuable index for AMD susceptibility.