Atopic Dermatitis: Disease Characteristics and Comorbidities in Smoking and Nonsmoking Patients from the TREATgermany Registry

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease with a multifactorial genesis including genetic predispositions and environmental risk and trigger factors. One of the latter possibly is smoking, indicated by an increased prevalence of AD in adults and children that are actively or passively exposed to cigarette smoke.

OBJECTIVES

In this study AD characteristics and its atopic comorbidities are compared in smoking and nonsmoking AD patients.

METHODS

TREATgermany is a non-interventional clinical registry which includes patients with moderate to severe AD in Germany. Baseline data of patients included into TREATgermany from inception in June 2016 to April 2020 in 39 sites across Germany was analyzed comparing AD disease characteristics and comorbidities in smokers versus non-smokers.

RESULTS

Of 921 patients, 908 (male: 58.7%) with a mean age of 41.9 ± 14.4 reported their smoking status. The objective Scoring of Atopic Dermatitis (oSCORAD) did not differ between smokers (n=352; 38.8%) and nonsmokers, however lesions' intensity of oozing/crusts and excoriations as well as patient global assessment scores (PGA) of AD severity were higher in smoking as opposed to nonsmoking patients. Smokers reported a lower number of weeks with well-controlled AD and more severe pruritus than nonsmokers. Total IgE levels were more elevated in smokers and they displayed a younger age at initial diagnosis of bronchial asthma. After adjustment for potential confounders, the increased intensity of oozing/crusts, the reduced number of weeks with well-controlled AD and the greater pruritus remained different in smokers compared to nonsmokers. In addition, smoking patients with adult-onset AD showed a 2.5 times higher chance of involvement of the feet.

CONCLUSIONS

German registry data indicate that AD patients who smoke have a higher disease burden with a different distribution pattern of lesions in adult-onset AD.

Addictions in patients with atopic dermatitis: a cross-sectional pilot study in Germany

BACKGROUND

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease worldwide and displays many atopic, but also non-atopic comorbidities. Among the latter, mental health disorders such as depression have been extensively studied. However, data on addictions are still rare.

OBJECTIVES

The aim of this study was to assess the prevalence of different kinds of addictions in adult AD patients using a single-centre approach.

METHODS

This non-interventional cross-sectional study was performed from 03/2020 to 05/2020 at the Department of Dermatology of a large German university hospital. Participants with a diagnosis of AD confirmed by a dermatologist answered questions about disease severity (patient-oriented eczema measure, POEM), quality of life (Dermatology Life Quality Index, DLQI) and smoking habits. They were screened for problematic alcohol consumption, drug abuse, internet addiction and pathological gambling using internationally established and validated questionnaires.

RESULTS

157 patients (56.1% female; mean age of 49.9 ± 20.4) with an average POEM of 13.7 ± 7.5 and DLQI of 6.1 ± 5.4 were evaluated. 14.1% were identified as regular smokers, 12.1% screened positive for alcohol dependency, 6.4% for drug use disorders, 4.5% for Internet addiction and 3.2% for pathological gambling. Co-occurrences of different addictions were observed, and a positive correlation was noted between DLQI scores and smoking.

CONCLUSIONS

In summary, this study hints at elevated positive screening rates for problematic alcohol consumption, drug use disorders, Internet addiction and problem gambling compared with the general population. Screening routinely for addictions may improve patient-centred health care of AD patients.

[Medical apps-possibilities for pruritus]

BACKGROUND

Apps have become part of our daily lives. Apps for pruritus could also play a role in the management of symptoms.

AIM

The aim of this article is to review existing apps for pruritus. In addition, we will discuss whether these apps have been validated and how and which offers might still be lacking.

MATERIALS AND METHODS

The two largest app stores as well as PubMed and Google were searched for apps regarding pruritus. Relevant medical apps were documented and categorized with respect to their functions. PubMed was searched to identify validation studies.

RESULTS

In total 21 apps for pruritus were identified. Of those 12 explicitly focused on pruritus, while 8 included pruritus as a symptom of an underlying disease (especially eczema and urticaria). The following app categories were derived: medical history of chronic pruritus, assessment of pruritus in clinical trials, assessment of nocturnal pruritus, information about pruritus, and diseases with pruritus as a symptom. Three of the apps with explicit focus on pruritus have been scientifically validated.

DISCUSSION

There are different apps for pruritus available. Most apps which explicitly focus on pruritus are aimed at physicians and scientists, while apps for diseases with pruritus as a symptom are more patient-centered. Due to technological advances, apps and wearables could improve management of pruritus in the future.

Happiness in dermatology: a holistic evaluation of the mental burden of skin diseases

BACKGROUND

According to the World Health Organization, mental health is a state of well-being and not merely the absence of disease. However, studies exploring subjective well-being in patients with skin diseases are very rare.

OBJECTIVES

To assess subjective well-being, i.e. 'happiness', in patients with different skin diseases and to compare them to other patient groups and healthy controls.

METHODS

A cross-sectional study was conducted from 12/2017 to 04/2019. Patients receiving in- or outpatient care for psoriasis, atopic eczema, nummular eczema, mastocytosis, skin cancer (malignant melanoma and keratinocyte carcinoma), human immunodeficiency virus (HIV) or chronic inflammatory bowel diseases (Crohn's disease and ulcerative colitis) were recruited at two hospitals in Bavaria, Germany. Healthy individuals living in or near Munich served as a control group. All participants filled in a questionnaire assessing happiness, measured as positive affect (PA), negative affect and satisfaction with life (SWL; together representing subjective well-being) and a heuristic evaluation of one's own happiness.

RESULTS

Data from 229 dermatologic patients (53.3 ± 18.5 years, 48% women), 49 patients with inflammatory bowel diseases (48.9 ± 18.7 years, 43% women), 49 patients with HIV (46 ± 10.1 years, 10% women) and 106 healthy controls (38.4 ± 13.4 years, 49% women) were analysed. Compared to the controls, dermatologic patients reported lower heuristic happiness (P = 0.023) and PA (P = 0.001) but higher SWL (P = 0.043). Patients with psoriasis and atopic eczema reported the lowest happiness, as they reported significantly lower PA (P = 0.032 and P < 0.001) and heuristic happiness (P = 0.002 and P = 0.015) than the control group. Patients with skin cancer reported higher SWL than the control group (P = 0.003). Dermatologic patients reported lower happiness than patients with HIV but reported greater happiness than patients with IBD.

CONCLUSIONS

Dermatologic patients experience lower levels of happiness, especially PA, compared to healthy controls. As PA is linked to desirable health outcomes, targeting PA could be a promising holistic approach for the treatment of skin diseases.

Primary prevention of keratinocyte carcinoma among outdoor workers, the general population and medical professionals: a systematic review updated for 2019

Worldwide 2-3 million cases of keratinocyte carcinoma (KC) are diagnosed annually. Sun-related knowledge is essential for adequate protection against solar ultraviolet radiation (UVR), the main risk factor for KC. The goal was (i) to provide an updated overview of primary prevention against KC including skin cancer-related knowledge, attitudes and sun protection behaviour (SPB) of outdoor workers, the general population and medical professionals as well as (ii) to evaluate the effectiveness and acceptability of sun protection programmes. We conducted a systematic review of articles indexed for MEDLINE on PubMed using selected MeSH terms and keywords related to the studied topic as well as an extensive hand search of publications between 1 January 2012 and 31 December 2018. We identified 51 relevant cross-sectional studies and 22 interventional studies. Sun-related knowledge and attitude showed substantial differences with some alarming results, including people who had not even heard about skin cancer before. Reported SPB varied enormously between the included studies, with none of the studies providing an overall sufficient SPB in their examined sun protection measures. However, sun protection programmes using new technologies seem to have great potential to increase sun-related knowledge and SPB. In countries worldwide, particularly in those where KC is not yet a public health issue, UVR protection should be promoted by healthcare institutions and authorities, politicians, cancer foundations and dermatologists to increase awareness as well as SPB and to decrease the worldwide burden of KC.

[Callus distraction and bone transport in the treatment of bone defects]

BACKGROUND

The method of "callus distraction" is the only technique which spontaneously produces vascularized bone within the surrounding soft tissues during lengthening reconstructive procedures. Remodeling of the regenerate bone to specific mechanical load can be influenced by the surgeon. In principle, there is no limit to the amount of new bone formation which can be created; this vascularized bone is both resistant to infection and can be created to replace resected infected bone. This is an important prerequisite for the successful treatment of large bone defects.

TECHNIQUE

The ring fixator is still a standard tool if no radiological control is available in the operating theater, or in other less sophisticated environments. Over the last 30 years, however, the development of motorized, external and fully implantable systems has made it possible to achieve a significant increase in device implementation, which goes far beyond the standard.

RESULTS

High-performance, reliable, custom-made external and fully implantable systems are cost intensive and require special surgical skills, which can only be ensured at specialized centers. However, the complication-free treatment results justify the effort both for the patient and, ultimately, for the cost bearers.

Lethal outcome after pelvic salvage radiotherapy in a patient with prostate cancer due to increased radiosensitivity : Case report and literature review

BACKGROUND

In general, late side effects after salvage radiotherapy (RT) for prostate cancer are below 10%. Patients with impaired DNA repair ability and genetic instability can have significantly increased reactions after RT.

CASE, CLINICAL FOLLOW-UP, AND EXAMINATION

We present a patient who experienced severe side effects after additive RT for prostate cancer and died from the complications 25 months after RT. Imaging (MR) is shown as well as three-color fluorescence in situ hybridization. The blood sample testing revealed that radiosensitivity was increased by 35-55%. We undertook a review of the literature to give an overview over the tests established that are currently considered useful.

CONCLUSION

This case highlights that the identification of patients with increased radiosensitivity is an important task in radiation protection. Groups of patients who should be screened have to be found and corresponding research facilities have to be set up.

Neurological Deficits of an Rps19(Arg67del) Model of Diamond-Blackfan Anaemia

Diamond-Blackfan anaemia is a rare disease caused by insufficient expression of ribosomal proteins and is characterized by erythroid hypoplasia often accompanied by growth retardation, congenital craniofacial and limb abnormalities. In addition, Diamond-Blackfan anaemia patients also exhibit a number of behavioural abnormalities. In this study we describe the behavioural effects observed in a new mouse mutant carrying a targeted single amino acid deletion in the ribosomal protein RPS19. This mutant, created by the deletion of arginine 67 in RPS19, exhibits craniofacial, skeletal, and brain abnormalities, accompanied by various neurobehavioural malfunctions. A battery of behavioural tests revealed a moderate cognitive impairment and neuromuscular dysfunction resulting in profound gait abnormalities. This novel Rps19 mutant shows behavioural phenotypes resembling that of the human Diamond-Blackfan anaemia syndrome, thus creating the possibility to use this mutant as a unique murine model for studying the molecular basis of ribosomal protein deficiencies.

Radiosensitization by BRAF inhibitor therapy-mechanism and frequency of toxicity in melanoma patients

BACKGROUND

Recent evidence suggests that ionizing radiation may be associated with unexpected side-effects in melanoma patients treated with concomitant BRAF inhibitors. A large multicenter analysis was carried out to generate reliable safety data and elucidate the mechanism.

METHODS

A total of 161 melanoma patients from 11 European skin cancer centers were evaluated for acute and late toxicity, of whom 70 consecutive patients received 86 series of radiotherapy with concomitant BRAF inhibitor therapy. To further characterize and quantify a possible radiosensitization by BRAF inhibitors, blood samples of 35 melanoma patients were used for individual radiosensitivity testing by fluorescence in situ hybridization of chromosomal breaks after ex vivo irradiation.

RESULTS

With radiotherapy and concomitant BRAF inhibitor therapy the rate of acute radiodermatitis ≥2° was 36% and follicular cystic proliferation was seen in 13% of all radiotherapies. Non-skin toxicities included hearing disorders (4%) and dysphagia (2%). Following whole-brain radiotherapy, rates of radiodermatitis ≥2° were 44% and 8% (P < 0.001) for patients with and without BRAF inhibitor therapy, respectively. Concomitant treatment with vemurafenib induced acute radiodermatitis ≥2° more frequently than treatment with dabrafenib (40% versus 26%, P = 0.07). In line with these findings, analysis of chromosomal breaks ex vivo indicated significantly increased radiosensitivity for patients under vemurafenib (P = 0.004) and for patients switched from vemurafenib to dabrafenib (P = 0.002), but not for patients on dabrafenib only. No toxicities were reported after stereotactic treatment.

CONCLUSION

Radiotherapy with concomitant BRAF inhibitor therapy is feasible with an acceptable increase in toxicity. Vemurafenib is a more potent radiosensitizer than dabrafenib.

[Strategies in the treatment of supracondylar fractures of the humerus in children - proven and controversial]

Elbow fractures are the 2nd most frequent fractures in children. Their therapy needs high expertise. Particularly an adequate analgesic therapy as well as an efficient and differentiated non-surgical or surgical therapy depending on the fracture type needs to be chosen. Secondary damage, especially growth disturbances, has to be prevented. Type I fractures can be managed conservatively with a cast. The crossed percutaneous pin fixation after open or closed reduction is the typical and most frequent surgical treatment option in supracondylar humeral fractures in children. Another good treatment option for supracondylar fractures type II to IV after closed reduction is the elastic-stable intramedullar nailing (ESIN). It is a minimally invasive treatment away from the fracture zone, which allows immediate free movement of the extremity. An immobilisation in a cast is therefore not necessary. That are the most possible effects (opinion of the authors) of the ESIN method, but discussed controversial in the literature. Especially neurovascular concomitant injuries require a differentiated treatment strategy to prevent long-term damage and should only be carried out in a specialised paediatric surgery unit. Long-term complications of supracondylar fractures are limitations in range of motion, nerval palsies, disturbances of growth, as well as cubitus varus (30 %) and valgus (3-7 %). These last ones often result from an insufficient initial anatomic reduction. The aim of the therapy should in any case be a patient-orientated treatment with the expected quickest recovery time and lowest long-term complications. Therefore supracondylar fractures should be treated only by a specialised paediatric trauma team, which can provide all non-surgical and surgical treatments. The spontaneous correcture is only seen in the sagittal view in young children between 6-7 years of age.

Extended middle cranial fossa approach for acoustic neuroma surgery

The enlarged middle cranial fossa approach was used for removal of acoustic neuromas in 209 cases. Complete tumor removal was accomplished in 96% of cases. Hearing was preserved in 51% of cases, with better results in smaller tumors. Our experience with the enlarged middle fossa approach has led us to discard the translabyrinthine approach for removal of acoustic neuromas.

Bilayer lipid membrane formation on a chemically modified S-layer lattice

The present paper describes the generation of a biomimetic model lipid membrane on bacterial surface (S-)layer which covered the entire surface of various sensors. The S-layer lattice allows one to be independent from the underlying solid material and provides a biological surface and anchoring structure for lipid membranes. S-layer proteins were chemically modified via binding of two amine-terminated phospholipids. Subsequently, a bimolecular lipid membrane anchored to the previously generated viscoelastic lipid monolayer was generated by the rapid solvent exchange technique. Characterization of the intermediate (monolayer) and final membrane structures (bilayer) was performed by imaging, surface-sensitive, and electrochemical techniques. This bilayer lipid membrane generated on an S-layer lattice revealed a thickness of ∼6 nm and constitutes a stable supported model membrane system with highly isolating properties showing a membrane resistance of 8.5 MΩ × cm(2).

Combining one-dimensional stray-field micro-imaging with mechanical field-cycling NMR: a new spectrometer design

A new spectrometer design combining stray-field micro-imaging with mechanical field-cycling Nuclear Magnetic Resonance (FC-NMR), allowing for one dimensional spatial resolution in the order of 10 μm is described. The field-cycle is implemented by moving the probe in the stray-field of a superconducting gradient magnet. In this way a field range between 10 mT and 6.3 T is covered. The maximum transfer time is less than 5 s. Further, methods to correct for some of the imaging artefacts found in previous studies are implemented. The main objective of this design is a depth- and field-dependent investigation of the defect structure caused by heavy-ion irradiation of ionic crystals.

Skeletal integrity and visceral transplantation

Despite continuous improvement in long-term survival, there is no knowledge about risk of bone health impairment and management strategies before and after intestinal transplantation. Therefore, 147 adults were retrospectively studied via chart review; 70 long-term survivors, 53 candidates and 24 recipients with longitudinal follow-up. Evaluation process included measurement of bone mineral density (BMD) and allied biochemical markers. Both long-term survivors and candidates showed low bone mass with lower (p < 0.05) z-scores at hip, femoral neck and spine. Vitamin D deficiency and secondary hyperparathyroidism were observed in both groups. Prevalence of osteoporosis was 44% among long-term survivors and 36% in candidates with age, BMD, duration of parenteral nutrition, type of immunosuppression and rejection being significant risk factors. Fragility fractures occurred at a higher (p = 0.02) rate among long-term survivors (20%) compared to candidates (6%). The longitudinal study documented acceleration (p = 0.025) of bone loss after transplantation with a decline of 13.4% (femoral neck), 12.7% (hip) and 2.1% (spine). Alendronate reduced (p < 0.05) but did not prevent bone loss. In conclusion, intestinal transplant recipients are at risk of osteoporosis secondary to bone loss before and after transplantation. Accordingly, current management includes comprehensive preventive measures with prompt therapeutic intervention utilizing intravenous bisphosphonates or subcutaneous human PTH.

Variation in umami taste perception in the German and Norwegian population

In this study, we investigated inter-individual differences in sensitivity to mono-sodium glutamate (MSG) and elucidated the familiarity to umami taste in two European populations. The study consisted of two parts: (1) a survey based on questionnaire and (2) psychophysical screening for inter-individual variation of MSG sensitivity. The psychophysical tests revealed that 3.2% of the German participants and 4.6% of the Norwegian participants were potential non-tasters of MSG. In conclusion, our study confirms inter-individual differences in sensitivity to MSG in humans.

Spatially resolved nuclear spin relaxation, electron spin relaxation and light absorption in swift heavy ion irradiated LiF crystals

Spatially resolved (19)F and (7)Li spin-lattice relaxation rates are measured for LiF single crystals after irradiation with two kinds of swift heavy ions ((12)C of 133 MeV and (208)Pb of 1.78 GeV incident energy). Like in earlier studies on (130)Xe and (238)U irradiated LiF crystals, we found a strong enhancement of the nuclear spin-lattice relaxation rate within the ion penetration depth and a slight--but still significant--enhancement beyond. By evaluating the nuclear relaxation rate enhancement within the ion range after irradiation with different projectiles, a universal relationship between the spin-lattice relaxation rate and the dose is deduced. The results of accompanying X-band electron paramagnetic resonance relaxation measurements and optical absorption spectroscopy are included in a physical interpretation of this relationship. Also the reason for the enhanced relaxation rate beyond the ion range is further discussed.

[Monitoring of anticoagulants of secondary haemostasis]

Vitamin K-antagonists and heparin belong to the established indirect acting anticoagulants. For many years these drugs were the only possibility for prophylaxis and treatment of venous and arterial thrombosis. The challenges for the routine laboratory related to the treatment with vitamin K-antagonists and heparin can be regarded as solved. However, in recent years a rapid development of new anticoagulants began. Although they are developed with guidelines for use without monitoring, the control of effective levels may be necessary in selected cases. As a consequence new challenges for the routine laboratory have to be solved. This paper presents an overview concerning monitoring methods.

Gustatory testing for clinicians

Gustatory testing for clinicians. By contrast with the evaluation of olfactory function, which has been standardised for almost two decades, the clinical assessment of gustatory function with psychophysical and objective testing is still in its infancy. This overview will attempt to summarise the knowledge that is important for clinicians in the awareness that progress in the field is ongoing. We focus on psychophysical testing but also discuss some recent achievements in the area of objective taste testing. There are now validated tests available for simple quick scans of gustatory function but debate continues about the extent to which such tests can be used for medico-legal purposes. In addition to emerging measures such as gustatory event-related potentials and functional imaging, routine objective gustatory testing will be needed in the future.

Monitoring of anticoagulants of secondary haemostasis

Vitamin K-antagonists and heparin belong to the established indirect acting anticoagulants. For many years these drugs were the only possibility for prophylaxis and treatment of venous and arterial thrombosis. The challenges for the routine laboratory related to the treatment with vitamin K-antagonists and heparin can be regarded as solved. However, in recent years a rapid development of new anticoagulants began. Although they are developed with guidelines for use without monitoring, the control of effective levels may be necessary in selected cases. As a consequence new challenges for the routine laboratory have to be solved. This paper presents an overview concerning monitoring methods.

Spatially resolved characterization of Xe ion irradiated LiF crystals using static field gradient NMR

Spatially resolved (19)F and (7)Li nuclear magnetic resonance (NMR) spin-lattice relaxation rates have been measured in LiF crystals irradiated with 1.44 GeV Xe ions at fluences from 10(10) to 10(12) ions cm(-2). In addition, the F-centre concentration has been measured by optical absorption spectroscopy and the concentration of paramagnetic centres by electron paramagnetic resonance (EPR). Within the ion range, the relaxation rate turns out to increase linearly with the concentration of paramagnetic centres but super-linearly with the F-centre concentration. Beyond the ion range, the relaxation rate is still significantly enhanced compared to non-irradiated LiF.

Solid supported lipid membranes: new concepts for the biomimetic functionalization of solid surfaces

Surface-layer (S-layer) supported lipid membranes on solid substrates are interfacial architectures mimicking the supramolecular principle of cell envelopes which have been optimized for billions of years of evolution in most extreme habitats. The authors implement this biological construction principle in a variety of layered supramolecular architectures consisting of a stabilizing protein monolayer and a functional phospholipid bilayer for the design and development of new types of solid-supported biomimetic membranes with a considerably extended stability and lifetime-compared to existing platforms-as required for novel types of bioanalytical sensors. First, Langmuir monolayers of lipids at the water/air interface are used as test beds for the characterization of different types of molecules which all interact with the lipid layers in various ways and, hence, are relevant for the control of the structure, stability, and function of supported membranes. As an example, the interaction of S-layer proteins from the bulk phase with a monolayer of a phospholipid synthetically conjugated with a secondary cell wall polymer (SCWP) was studied as a function of the packing density of the lipids in the monolayer. Furthermore, SCWPs were used as a new molecular construction element. The exploitation of a specific lectin-type bond between the N-terminal part of selected S-layer proteins and a variety of glycans allowed for the buildup of supramolecular assemblies and thus functional membranes with a further increased stability. Next, S-layer proteins were self-assembled and characterized by the surface-sensitive techniques, surface plasmon resonance spectroscopy and quartz crystal microbalance with dissipation monitoring. The substrates were either planar gold or silicon dioxide sensor surfaces. The assembly of S-layer proteins from solution to solid substrates could nicely be followed in-situ and in real time. As a next step toward S-layer supported bilayer membranes, the authors characterized various architectures based on lipid molecules that were modified by a flexible spacer separating the amphiphiles from the anchor group that allows for a covalent coupling of the lipid to a solid support, e.g., using thiols for Au substrates. Impedance spectroscopy confirmed the excellent charge barrier properties of these constructs with a high electrical resistance. Structural details of various types of these tethered bimolecular lipid membranes were studied by using neutron reflectometry. Finally, first attempts are reported to develop a code based on a SPICE network analysis program which is suitable for the quantitative analysis of the transient and steady-state currents passing through these membranes upon the application of a potential gradient.

Chemosensory specific reduction of trigeminal sensitivity in subjects with olfactory dysfunction

Humans with olfactory loss have been found to exhibit a decreased sensitivity of the chemosensory trigeminal system. It is not clear, whether the reduced trigeminal sensitivity is restricted to the chemosensitive properties of the trigeminal nerve, or whether it reflects a general decrease of trigeminal sensitivity which is also found for cutaneous afferents. To investigate the relationship between cutaneous somatosensory and intranasal chemosensory trigeminal sensitivity, 91 subjects were investigated. Forty-five of them were considered healthy controls, whereas 46 subjects had olfactory dysfunction. Subjects with olfactory dysfunction were found to have higher thresholds for CO2 than controls indicating lower trigeminal chemosensory sensitivity in subjects with olfactory dysfunction. Both etiology and degree of olfactory dysfunction appeared to have an impact on CO2 thresholds. In contrast, no such differences were found with regard to detection thresholds for electrical cutaneous stimulation. These results indicate that the decrease of trigeminal sensitivity in subjects with olfactory dysfunction is specific for chemosensory sensations.

S-layer proteins as key components of a versatile molecular construction kit for biomedical nanotechnology

Surface (S)-layer proteins and S-layer fusion proteins incorporating functional sequences, self-assemble into monomolecular lattices on solid supports and on various lipid structures. Based on these S-layer proteins, supramolecular assemblies can be constructed which are envisaged for label-free detection systems, as affinity matrix, as anti-allergic immuno-therapeutics, as membrane protein-based screening devices, and as drug targeting and delivery systems.

Functionalisation of surfaces with S-layers

Two-dimensional bacterial surface layer protein crystals (S-layers) are the most commonly observed cell surface structures in prokaryotic organisms (bacteria and archaea). Isolated S-layer proteins have the intrinsic tendency to self-assemble into two-dimensional arrays in suspension and at various interfaces. Basic research on the structure, genetics, chemistry, morphogenesis and function of S-layers has led to a broad spectrum of applications in molecular nanotechnology and biomimetics. The possibility to change the natural properties of S-layer proteins by genetic manipulation opens new ways for the tuning of their structural and functional features. Functionalised S-layer proteins that maintain their propensity for self-assembly have led to new affinity matrices, diagnostic tools, vaccines or biocompatible surfaces, as well as to biological templating or specific biomineralisation strategies at surfaces.

Subjects with Congenital Anosmia Have Larger Peripheral but Similar Central Trigeminal Responses

Most odorants not only stimulate olfactory receptor neurons but also activate the intranasal trigeminal nerve. The simultaneous activation of the olfactory and the trigeminal system leads to an interaction in the brain. Therefore, assessment of the trigeminal impact of odorants may be difficult in subjects with a normal sense of smell. To obtain a deeper insight into both, mechanisms of changes in trigeminal sensitivity in anosmic patients and interactions between the olfactory/trigeminal systems in healthy subjects, 21 patients with isolated congenital anosmia (ICA) were investigated in this series of explorative, hypothesis-generating experiments and compared with 35 healthy controls. Trigeminal sensitivity was measured by psychophysical (lateralization task, intensity ratings) and electrophysiological (trigeminal event-related potential, negative mucosal potential) means. ICA patients were found to have higher peripheral activation than controls. On central levels, however, similar responsiveness to trigeminal stimuli was found in ICA patients when compared with healthy subjects. The results of the study are discussed by proposing a model of mixed sensory adaptation/compensation in the interactions between olfactory and the trigeminal system.

Phase 2 trial of WR6026, an orally administered 8-aminoquinoline, in the treatment of visceral leishmaniasis caused by Leishmania chagasi

There are no recognized orally administered treatments for any of the leishmaniases. The 8-aminoquinoline WR6026 is an orally administered analog of primaquine that cured 50% of patients with kala-azar in Kenya at a dose of 1 mg/kg/day for 28 days. A further phase 2, open-label, dose-escalating safety and efficacy study was performed for kala-azar in Brazil. Cure rates for Brazilian patients treated for 28 days were as follows: 1 mg/kg/day: 0 of 4 (0%); 1.5 mg/kg/day: 1 of 6 (17%); 2.0 mg/kg/day: 4 of 6 (67%); 2.5 mg/kg/day: 1 of 5 (20%); and 3.25 mg/kg/day: 0 of 1 (0%). Nephrotoxicity that was not anticipated from preclinical animal studies or from phase 1 studies was seen at 2.5 mg/kg/day in 2 patients and in the single patient administered 3.25 mg/kg/day. WR6026 demonstrated the unusual clinical features of lack of increased efficacy against Brazilian kala-azar with increased dosing above 2 mg/kg/day and toxicity that was not present in previous investigations.

What did we learn about national organizational collaboration at the advisory committee level?

This article provides an overview of the typical roles and tasks of advisory groups in general, followed by a discussion of the roles and tasks the Interdisciplinary Generalist Curriculum (IGC) Project Advisory Committee was asked to assume and how these were fulfilled. It analyzes the lessons learned about advisory committees as a result of the IGC Project experience. Key elements of success in fulfilling advisory committee obligations include well-defined expectations, periodic evaluations, and clear communication between project leadership and the members of the advisory committee. In the spirit of lessons learned from the IGC Project, this critique identifies several philosophical and logistic issues that might be considered in the design and implementation of future projects, such as the need to choose committed, high-energy advisory committee members who are willing to perform many complex, time-consuming tasks.

S-layer-supported lipid membranes

Many prokaryotic organisms (archaea and bacteria) are covered by a regularly ordered surface layer (S-layer) as the outermost cell wall component. S-layers are built up of a single protein or glycoprotein species and represent the simplest biological membrane developed during evolution. Pores in S-layers are of regular size and morphology, and functional groups on the protein lattice are aligned in well-defined positions and orientations. Due to the high degree of structural regularity S-layers represent unique systems for studying the structure, morphogenesis, and function of layered supramolecular assemblies. Isolated S-layer subunits of numerous organisms are able to assemble into monomolecular arrays either in suspension, at air/water interfaces, on planar mono- and bilayer lipid films, on liposomes and on solid supports (e.g. silicon wafers). Detailed studies on composite S-layer/lipid structures have been performed with Langmuir films, freestanding bilayer lipid membranes, solid supported lipid membranes, and liposomes. Lipid molecules in planar films and liposomes interact via their head groups with defined domains on the S-layer lattice. Electrostatic interactions are the most prevalent forces. The hydrophobic chains of the lipid monolayers are almost unaffected by the attachment of the S-layer and no impact on the hydrophobic thickness of the membranes has been observed. Upon crystallization of a coherent S-layer lattice on planar and vesicular lipid membranes, an increase in molecular order is observed, which is reflected in a decrease of the membrane tension and an enhanced mobility of probe molecules within an S-layer-supported bilayer. Thus, the terminology 'semifluid membrane' has been introduced for describing S-layer-supported lipid membranes. The most important feature of composite S-layer/lipid membranes is an enhanced stability in comparison to unsupported membranes.

Probing the stability of S-layer-supported planar lipid membranes

Isolated protein subunits of the crystalline bacterial cell surface layer (S-layer) of Bacillus coagulans E38-66 have been recrystallized on one side of planar black lipid membranes (BLMs) and their influence on the electrical properties, rupture kinetics and mechanical stability of the BLM was investigated. The effect on the boundary potential, the capacitance or the conductance of the membrane was negligible whereas the mechanical properties were considerably changed. The mechanical stability was characterized by applying voltage pulses or ramps to induce irreversible rupture. The amplitude of the voltage pulse leading to rupture allows conclusions on the ability of membranes to resist external forces. Surprisingly, these amplitudes were significantly lower for composite S-layer/lipid membranes compared to undecorated BLMs. In contrast, the delay time between the voltage pulse and the appearance of the initial defect was found to be drastically longer for the S-layer-supported lipid bilayer. Furthermore, the kinetics of the rupture process was recorded. Undecorated membranes show a fast linear increase of the pore conductance in time, indicating an inertia-limited defect growth. The attachment of an S-layer causes a slow exponential increase in the conductance during rupture, indicating a viscosity-determined widening of the pore. In addition, the mechanical properties on a longer time scale were investigated by applying a hydrostatic pressure across the BLMs. This causes the BLM to bulge, as monitored by an increase in capacitance. Compared to undecorated BLMs, a significantly higher pressure gradient has to be applied on the S-layer face of the composite BLMs to observe any change in capacitance.

Understanding individual differences in word recognition skills of ESL children

This paper focuses on the extent to which the development of ESL (English as a Second Language) word recognition skills mimics similar trajectories in same-aged EL1 (English as a First Language) children, and the extent to which phonological processing skills and rapid naming can be used to predict word recognition performance in ESL children. Two cohorts of Grade 1 ESL and EL1 primary-level children were followed for two consecutive years. Results indicated that vocabulary knowledge, a measure of language proficiency, and nonverbal intelligence were not significant predictors of word recognition in either group. Yet, by considering individual differences in phonological awareness and rapid naming, it was possible to predict substantial amounts of variance on word recognition performance six months and one year later in both language groups. Commonality analyses indicated that phonological awareness and rapid naming contributed unique variance to word recognition performance. Moreover, the profiles of not at-risk children in the EL1 and ESL groups were similar on all but the oral language measure, where EL1 children had the advantage. In addition, EL1 and ESL profiles of children who had word-recognition difficulty were similar, with low performance on rapid naming and phonological awareness. Results indicate that these measures are reliable indicators of potential reading disability among ESL children.

The effect of S-layer protein adsorption and crystallization on the collective motion of a planar lipid bilayer studied by dynamic light scattering

A dedicated dynamic light scattering (DLS) setup was employed to study the undulations of freely suspended planar lipid bilayers, the so-called black lipid membranes (BLM), over a previously inaccessible spread of frequencies (relaxation times ranging from 10(-2) to 10(-6) s) and wavevectors (250 cm(-1) < q < 38,000 cm(-1)). For a BLM consisting of 1,2-dielaidoyl-sn-3-glycero-phosphocholine (DEPC) doped with two different proportions of the cationic lipid analog dioctadecyl-dimethylammonium bromide (DODAB) we observed an increase of the lateral tension of the membrane with the DODAB concentration. The experimentally determined dispersion behavior of the transverse shear mode was in excellent agreement with the theoretical predictions of a first-order hydrodynamic theory. The symmetric adsorption of the crystalline bacterial cell surface layer (S-layer) proteins from Bacillus coagulans E38-66 to a weakly cationic BLM (1.5 mol % DODAB) causes a drastic reduction of the membrane tension well beyond the previous DODAB-induced tension increase. The likely reason for this behavior is an increase of molecular order along the lipid chains by the protein and/or partial protein penetration into the lipid headgroup region. S-layer protein adsorption to a highly cationic BLM (14 mol % DODAB) shows after 7 h incubation time an even stronger decrease of the membrane tension by a factor of five, but additionally a significant increase of the (previously negligible) surface viscosity, again in excellent agreement with the hydrodynamic theory. Further incubation (24 h) shows a drastic increase of the membrane bending energy by three orders of magnitude as a result of a large-scale, two-dimensional recrystallization of the S-layer proteins at both sides of the BLM. The results demonstrate the potential of the method for the assessment of the different stages of protein adsorption and recrystallization at a membrane surface by measurements of the collective membrane modes and their analysis in terms of a hydrodynamic theory.

Microphase separation in low density lipoproteins. Evidence for a fluid triglyceride core below the lipid melting transition

The structural organization of the neutral lipid core in human low density lipoproteins (LDL) was investigated in physicochemically defined, distinct human LDL subspecies in the density range of 1. 0244-1.0435 g/ml by evaluation of the core lipid transition temperature, chemical composition, and the behavior of spin-labeled core lipids. Calorimetric studies were performed on more than 60 LDL preparations, and the transition temperature, which varied between 19 and 32 degreesC, was correlated to the chemical composition and revealed a discontinuity at a critical cholesteryl ester to triglyceride ratio of approximately 7:1. For electron spin resonance studies, several LDL preparations were probed with spin-labeled cholesteryl esters and triglycerides, respectively. In LDL with a high triglyceride content, both labels exhibited similar mobility behavior. In contrast, in LDL with only small concentrations of triglycerides, the behavior of labeled cholesteryl esters and labeled triglycerides differed distinctly. The cholesteryl esters were strongly immobilized below the transition temperature, whereas the triglycerides remained fluid throughout the measured temperatures. These results suggest that the critical cholesteryl ester to triglyceride mass ratio of 7:1 corresponds to two concentric compartments with a radial ratio of 2:1, where the liquid triglycerides occupy the core, and the cholesteryl esters form the frozen shell. At higher triglyceride contents, the triglyceride molecules insert into the cholesteryl ester shell and depress the peak transition temperature of the LDL core, whereas at lower triglyceride contents, excess cholesteryl esters are dissolved in the core.

Self-assembled alpha-hemolysin pores in an S-layer-supported lipid bilayer

The effects of a supporting proteinaceous surface-layer (S-layer) from Bacillus coagulans E38-66 on a 1,2-diphytanoyl-sn-glycero-3-phosphatidylcholine (DPhPC) bilayer were investigated. Comparative voltage clamp studies on plain and S-layer supported DPhPC bilayers revealed no significant difference in the capacitance. The conductance of the composite membrane decreased slightly upon recrystallization of the S-layer. Thus, the attached S-layer lattice did not interpenetrate or rupture the DPhPC bilayer. The self-assembly of a pore-forming protein into the S-layer supported lipid bilayer was examined. Staphylococcal alpha-hemolysin formed lytic pores when added to the lipid-exposed side. The assembly was slow compared to unsupported membranes, perhaps due to an altered fluidity of the lipid bilayer. No assembly could be detected upon adding alpha-hemolysin monomers to the S-layer-faced side of the composite membrane. Therefore, the intrinsic molecular sieving properties of the S-layer lattice do not allow passage of alpha-hemolysin monomers through the S-layer pores to the lipid bilayer. In comparison to plain lipid bilayers, the S-layer supported lipid membrane had a decreased tendency to rupture in the presence of alpha-hemolysin.

Voltage clamp studies on S-layer-supported tetraether lipid membranes

Isolated subunits from the cell surface proteins (S-layer) of Bacillus coagulans E38-66 have been recrystallized on a glycerol dialkyl nonitol tetraether lipid (GDNT)-monolayer and the electrophysical features of this biomimetic membrane have been investigated in comparison to unsupported GDNT-monolayers. The GDNT-monolayer, spread on a Langmuir-Blodgett trough, was clamped with the tip of a glass patch pipette. In order to investigate the barrier function and potential to incorporate functional molecules, voltage-clamp examinations on plain and S-layer-supported GDNT-monolayers were per-formed. Our results indicate the formation of a tight GDNT-monolayer sealing the tip of the glass pipette, and a decrease in conductance of the GDNT-monolayer upon recrystallization of the S-layer protein. Thus, the S-layer protein, apparently, did not penetrate or rupture the lipid monolayer. The valinomycin-mediated increase in conductance was less pronounced for the S-layer-supported than for the plain GDNT-monolayer, indicating differences in the accessibility and/or in the fluidity of the lipid membranes. Furthermore. in contrast to plain GDNT-monolayers. S-layer supported GDNT-monolayers with high valinomycin-mediated conductance persisted over long, periods of time, indicating enhanced stability. These composite S-layer/lipid films may constitute a new tool for electrophysical and electrophysiological studies on membrane-associated and membrane-integrated biomolecules.

Thermal stability of apolipoprotein B100 in low-density lipoprotein is disrupted at early stages of oxidation while neutral lipid core organization is conserved

The time course of the unfolding characteristics of the protein moiety and of the thermotropic behavior of the core-located apolar lipids of highly homogeneous low-density lipoprotein (LDL) subspecies (d 1.030-1.040 g/mL) have been evaluated during transition metal- and azo radical-induced oxidation using differential scanning calorimetry. Apolipoprotein B100 (apo-B100) structure was highly sensitive to oxidative modification; indeed, a significant loss of thermal stability was observed at initial stages irrespective of whether oxidation was mediated by site-specific binding of copper ions or by free radicals generated during decomposition of azo compounds. Subsequently, thermal protein integrity was destroyed, as a result of potentially irreversible protein unfolding, cross-linking reactions, and aggregation. Our results suggest that even minimal oxidative modification of apo-B100 has a major impact on the stability of this large monomeric protein. By contrast, the core lipids, which consist primarily of cholesteryl esters and triglycerides and play a determinant role in the thermal transition occurring near physiological temperature, preserved features of an ordered arrangement even during propagation of lipid peroxidation.

Applications of S-layers

The wealth of information existing on the general principle of S-layers has revealed a broad application potential. The most relevant features exploited in applied S-layer research are: (i) pores passing through S-layers show identical size and morphology and are in the range of ultrafiltration membranes; (ii) functional groups on the surface and in the pores are aligned in well-defined positions and orientations and accessible for binding functional molecules in very precise fashion; (iii) isolated S-layer subunits from many organisms are capable of recrystallizing as closed monolayers onto solid supports at the air-water interface, on lipid monolayers or onto the surface of liposomes. Particularly their repetitive physicochemical properties down to the subnanometer scale make S-layers unique structures for functionalization of surfaces and interfaces down to the ultimate resolution limit. The following review focuses on selected applications in biotechnology, diagnostics, vaccine development, biomimetic membranes, supramolecular engineering and nanotechnology. Despite progress in the characterization of S-layers and the exploitation of S-layers for the applications described in this chapter, it is clear that the field lags behind others (e.g. enzyme engineering) in applying recent advances in protein engineering. Genetic modification and targeted chemical modification would allow several possibilities including the manipulation of pore permeation properties, the introduction of switches to open and close the pores, and the covalent attachment to surfaces or other macromolecules through defined sites on the S-layer protein. The application of protein engineering to S-layers will require the development of straightforward expression systems, the development of simple assays for assembly and function that are suitable for the rapid screening of numerous mutants and the acquisition of structural information at atomic resolution. Attention should be given to these areas in the coming years.

Effect of temperature and phase transition on oxidation resistance of low density lipoprotein

The study of the effect of temperature on the kinetics of low density lipoprotein (LDL) oxidation was carried out by measuring the conjugated diene (CD) versus time curves at a fixed LDL concentration (0.1 microM) and at different Cu2+ concentrations (0.5-10 microM) in a wide temperature range, from 10 degrees C to 45 degrees C. The core melting point of the LDL determined with differential scanning calorimetry was 31.1 degrees C. We have demonstrated that temperature exerts a clear effect in the Cu(2+)-mediated LDL oxidation, with a strong decrease in lag time and a notable increase in the rate of propagation. This temperature dependence of lag time and rate of propagation fully obeys the Arrhenius law, suggesting that the core melting point of the LDL has no or only a minor effect on these oxidation indices. The Arrhenius plots of the binding of Cu2+ to LDL, measured by K, gave two breaks suggesting that this value is affected by the core transition of the LDL as well as by structural changes at around 15 degrees C. The mean activation energy during rate of initiation was 13.5 kcal/mol and tended to decrease with increasing Cu2+ concentration. The activation energy in the propagation phase was 10.6 kcal/mol and was independent of Cu2+ concentration. In this work we have also shown that the CD method can be conducted with high reproducibility and that a sucrose-supplemented plasma frozen at -80 degrees C can be used as a source of LDL with an unvarying vitamin E content and reproducible oxidation properties.

The mechanism of action of phenylalanine ammonia-lyase: the role of prosthetic dehydroalanine

Phenylalanine ammonia-lyase (EC 4.3.1.5) from parsley is posttranslationally modified by dehydrating its Ser-202 to the catalytically essential dehydroalanine prosthetic group. The codon of Ser-202 was changed to those of alanine and threonine by site-directed mutagenesis. These mutants and the recombinant wild-type enzyme, after treatment with sodium borohydride, were virtually inactive with L-phenylalanine as substrate but catalyzed the deamination of L-4-nitrophenylalanine, which is also a substrate for the wild-type enzyme. Although the mutants reacted about 20 times slower with L-4-nitrophenylalanine than the wild-type enzyme, their Vmax for L-4-nitrophenylalanine was two orders of magnitude higher than for L-phenylalanine. In contrast to L-tyrosine, which was a poor substrate, DL-3-hydroxyphenylalanine (DL-m-tyrosine) was converted by phenylalanine ammonia-lyase at a rate comparable to that of L-phenylalanine. These results suggest a mechanism in which the crucial step is an electrophilic attack of the prosthetic group at position 2 or 6 of the phenyl group. In the resulting carbenium ion, the beta-HSi atom is activated in a similar way as it is in the nitro analogue. Subsequent elimination of ammonia, concomitant with restoration of both the aromatic ring and the prosthetic group, completes the catalytic cycle.