In-situ investigation of solid phase evolution during lyophilization of mannitol-based antibody formulations using an XRPD climate chamber

Crystalline mannitol is commonly used as bulking agent in antibody formulations to provide structure to the lyophilized cake and prevent collapse. Depending on the lyophilization process conditions mannitol can either crystallize as α-, β-, δ-mannitol, mannitol-hemihydrate, or transition to its amorphous state. While crystalline mannitol helps to create a firmer cake structure this is not true for amorphous mannitol. The hemihydrate is also an undesired physical form as it may reduce the drug product stability by releasing bound water molecules into the cake. Our aim was to simulate lyophilization processes in an X-ray powder diffraction (XRPD) climate chamber. In the climate chamber, the process can be carried out fast with low sample quantities to determine optimal process conditions. Insights on the emergence of desired anhydrous mannitol forms helps to adjust the process parameters in larger scale freeze-dryers. In our study we have identified the critical process steps for our formulations and then varied relevant process parameters, which were the annealing temperature, annealing time and temperature ramp rate of the freeze-drying process. Furthermore, the effect of the presence of antibodies on excipient crystallization was investigated by performing the studies on placebo solutions versus two respective antibody formulations. A comparison of the products obtained in a freeze-dryer and the simulated process in the climate chamber showed good accordance demonstrating the method as suitable tool to identify ideal process conditions on a laboratory scale.

Large abdominal mechanoreceptive sense organs in small plant-dwelling insects

The Hemiptera, with approximately 98 000 species, is one of the largest insect orders. Most species feed by sucking sap from plant tissues and are thus often vectors for economically important phytopathogens. Well known within this group are the large cicadas (Cicadomorpha: Cicadoidea: Cicadidae) because they produce extremely loud airborne sounds. Less well known are their mostly tiny relatives, the leafhoppers, spittlebugs, treehoppers and planthoppers that communicate by silent vibrational signals. While the generation of these signals has been extensively investigated, the mechanisms of their perception are poorly understood. This study provides a complete description and three-dimensional reconstruction of a large and complex array of mechanoreceptors in the first abdominal segments of the Rhododendron leafhopper Graphocephala fennahi (Cicadomorpha: Membracoidea: Cicadellidae). Further, we identify homologous organs in the spittlebug Philaenus spumarius (Cicadomorpha: Cercopoidea: Aphrophoridae) and the planthopper Issus coleoptratus (Fulgoromorpha: Fulgoroidea: Issidae). Such large abdominal sensory arrays have not been found in any other insect orders studied so far. This indicates that these sense organs, together with the signal-producing tymbal organ, constitute a synapomorphy of the Tymbalia (Hemiptera excl. Sternorrhyncha). Our results contribute to the understanding of the evolution from substrate-borne to airborne communication in insects.

Contributions to the biodiversity of Vietnam – Results of VIETBIO inventory work and field training in Cuc Phuong National Park

VIETBIO [Innovative approaches to biodiversity discovery and characterisation in Vietnam] is a bilateral German-Vietnamese research and capacity building project focusing on the development and transfer of new methods and technology towards an integrated biodiversity discovery and monitoring system for Vietnam. Dedicated field training and testing of innovative methodologies were undertaken in Cuc Phuong National Park as part and with support of the project, which led to the new biodiversity data and records made available in this article collection.

VIETBIO is a collaboration between the Museum für Naturkunde Berlin – Leibniz Institute for Evolution and Biodiversity Science (MfN), the Botanic Garden and Botanical Museum, Freie Universität Berlin (BGBM) and the Vietnam National Museum of Nature (VNMN), the Institute of Ecology and Biological Resources (IEBR), the Southern Institute of Ecology (SIE), as well as the Institute of Tropical Biology (ITB); all Vietnamese institutions belong to the Vietnam Academy of Science and Technology (VAST).

The article collection "VIETBIO" (https://doi.org/10.3897/bdj.coll.63) reports original results of recent biodiversity recording and survey work undertaken in Cuc Phuong National Park, northern Vietnam, under the framework of the VIETBIO project. The collection consist of this “main” cover paper – characterising the study area, the general project approaches and activities, while also giving an extensive overview on previous studies from this area – followed by individual papers for higher taxa as studied during the project. The main purpose is to make primary biodiversity records openly available, including several new and interesting findings for this biodiversity-rich conservation area. All individual data papers with their respective primary records are expected to provide useful baselines for further taxonomic, phylogenetic, ecological and conservation-related studies on the respective taxa and, thus, will be maintained as separate datasets, including separate GUIDs also for further updating.

Process optimization and transfer of freeze-drying in nested vial systems

Scale-up and transfer of freeze-drying processes is a crucial challenge in biopharma industry. With the success of small batch processing lines utilizing rack vial holding systems, further detailed knowledge about freeze-drying cycles and their scale-up for vials in a rack is required. Therefore, product temperature (T_P) profiles as well as Kv values of vials nested in a Polyetheretherketon (PEEK) rack were compared to those of vials placed in a commonly used stainless steel tray. Additionally, both setups were challenged with varying fill volume and partially versus fully loaded rack. Additionally, a process developed for rack was compared to a tray freeze-drying cycle. Freeze-drying in vials placed in the rack is markedly faster for center vials and more homogeneous compared to vials in bulk tray setting, as indicated by T_P and Kv values. Due to the more homogeneous drying the rack is more flexible regarding variation of the fill volume. The key point for the transfer of a freeze-drying cycle from rack to tray is to consider the higher sublimation rates in the rack by adapting chamber pressure or shelf temperature for the tray. Furthermore, transfer from one rack per shelf in a laboratory freeze-dryer to pilot scale with four racks per shelf was successful. Thus, understanding of the process in rack and tray setup was enhanced to ensure efficient scale-up and transfer of freeze-drying processes.

Impact of chamber wall temperature on energy transfer during freeze-drying

Minimization of radiation coming from the chamber wall during lyophilization has the potential to reduce the edge-vial-effect. The edge-vial-effect is a phenomenon in which vials positioned at the shelf edges and corners tend to run warmer compared to center vials. A higher product temperature may result in product collapse in these vials. Consequently, more conservative and time-consuming freeze-drying cycles with lower shelf temperatures and pressures are chosen to ensure a product temperature below the collapse temperature in all vials. The edge-vial-effect is of even higher impact in small batches, where the ratio of corner and edge to center vials is higher compared to large scale manufacturing. The chamber wall is often discussed as the primary source of radiation impacting corner and edge vials. A radiation cage was set at different low temperatures to determine the impact of chamber wall temperatures below 0 °C on product temperature. At the end of primary drying, product temperature of corner vials could be reduced by 6 °C through the radiation cage but primary drying was elongated. Compared to vials in a tray, the chamber wall temperature had less impact on vials nested in a rack system due to a shielding effect of the rack itself. Corner and center vials ran more homogeneous with radiation cage since the edge and corner vials were slowed down. The difference in primary drying time between corner and center vials in the tray could be significantly reduced by 18% by means of 7 h when the radiation cage was controlled at product temperature and combined with a higher shelf temperature. In summary, the radiation cage is a useful tool for a more homogeneous batch with the potential to reduce primary drying time. Nevertheless, the drying difference between corner and center vials could only be reduced and was not completely eliminated.

Estimating and Explaining the Prevalence of Tuberculosis for Asylum Seekers Upon Their Arrival in Germany

Up until recently incidences of tuberculosis (TB) had been declining for many years in Germany. The rise in TB cases coincided with a large increase in the number of people applying for asylum. We combine data from various sources to estimate the at-entry prevalence of TB for asylum seekers from 18 countries of origin and rely on survey data to explain the varying risk of suffering from TB. Our results reveal that asylum seekers from Eastern Africa show a much higher risk of suffering from TB than asylum seekers from Afghanistan, Syria, or Iraq. The survey data suggests that asylum seekers from Africa were by far more underprivileged in their respective countries of origin and experienced a higher risk of contracting TB on their way to Germany. Information about the socio-economic situation and the circumstances of the journey to Germany may help to improve TB surveillance.

Secondary Syphilis

Case Presentation

A 40-year-old male presented the the emergency department (ED) due to a diffuse body rash after a sexual encounter. Examination revealed a maculopapular rash that included the palms and soles of the feet bilaterally. A rapid plasma reagin was positive, and the patient was treated with 2.4 million units of benzathine benzylpenicillin intramuscularly.

Diagnosis

Secondary syphilis can mimic many disease processes but classically presents as a painless macular rash on the palms of the hands and soles of the feet. Diagnosis is based upon clinical examination coupled with serological testing. Emergency department management should include 2.4 million units of benzathine benzylpenicillin intramuscularly and mitigation strategies.

Trouble With the Neighbor During Freeze-Drying: Rivalry About Energy

Batch homogeneity during lyophilization is crucial to ensure products with high quality. Known as edge-vial-effect, vials at the corners and edges tend to run warmer than center vials during primary drying. This is associated with risk of collapse or increased costs due to use of more conservative, longer drying conditions resulting in lower product temperature. The edge-vial-effect has been attributed to radiation coming from the chamber wall. We could show that the neighbor vial has a dominant impact on product temperature during lyophilization. Depending on the number of neighbors as well as the distance to a neighbor vial, the neighbor vial exerts a remarkable cooling effect. Energy transfer by gas conduction enables the cooling effect of a neighboring vial over a distance up to 10 mm. This not only leads to prolonged primary drying but also impacts cake appearance. Thus, to avoid trouble during lyophilization you have to watch out for the neighborhood.

Taxonomy and biogeography of Hemphillia (Gastropoda: Pulmonata: Arionidae) in North American rainforests, with description of a new species (Skade’s jumping-slug, Hemphillia skadei sp. nov.)

Species diversity of the genus Hemphillia Bland and W.G. Binney, 1872 (jumping-slugs) was studied across its range in western North America’s inland temperate rainforests. The taxonomic relationships among jumping-slug populations were clarified by integrating morphological, molecular, and biogeographic approaches. A new species, Skade’s jumping-slug (Hemphillia skadei sp. nov.), was discovered in this process and is described herein. We base this taxonomic decision on molecular comparison of representatives from other Hemphillia species and four morphological characters that distinguish H. skadei from its sister species, the pale jumping-slug (Hemphillia camelus Pilsbry and Vanatta, 1897). The distribution of H. skadei and H. camelus is described along with the notable lack of detection of the marbled jumping-slug (Hemphillia danielsi Vanatta, 1914) within the primary survey area.

In vivo virulence of Mycobacterium tuberculosis depends on a single homologue of the LytR-CpsA-Psr proteins

LytR-cpsA-Psr (LCP) domain containing proteins fulfil important functions in bacterial cell wall synthesis. In Mycobacterium tuberculosis complex (Mtbc) strains, the causative agents of tuberculosis (TB), the genes Rv3484 and Rv3267 encode for LCP proteins which are putatively involved in arabinogalactan transfer to peptidoglycan. To evaluate the significance of Rv3484 for Mtbc virulence, we generated a deletion mutant in the Mtbc strain H37Rv and studied its survival in mice upon aerosol infection. The deletion mutant failed to establish infection demonstrating that Rv3484 is essential for growth in mice. Following an initial phase of marginal replication in the lungs until day 21, the Rv3484 deletion mutant was almost eliminated by day 180 post-infectionem. Interestingly, the mutant also showed higher levels of resistance to meropenem/clavulanate and lysozyme, both targeting peptidoglycan structure. We conclude that Rv3484 is essential for Mtbc virulence in vivo where its loss of function cannot be compensated by Rv3267.

Major Contributors to Hospital Mortality in Very-Low-Birth-Weight Infants: Data of the Birth Year 2010 Cohort of the German Neonatal Network

The German Neonatal Network (GNN) is a prospective cohort study with the focus on long term development of very-low-birth-weight infants. It was the aim of this study to determine detailed information on causes of mortality in the GNN birth cohort 2010.

Major contributors to hospital mortality were recorded by the attending neonatologists for the cohort of very-low-birth-weight (VLBW) infants born in centres of the German Neonatal Network (GNN) in 2010. The data quality was approved by on-site monitoring.

2 221 VLBW infants were born in GNN centres in 2010, and death occurred in 221 infants. Male infants carried a higher risk than females (58.8% males among non-survivors vs. 51.7% among survivors, p=0.047). In 11 infants, the major contributor to death was not determined by the attending neonatologist. In 25 infants born at the limit of viability, comfort palliative care was primarily initiated and 14 infants had lethal malformations. The majority of non-survivors suffered from inflammatory diseases including sepsis- or necrotizing enterocolitis (NEC)-associated death (n=56). Respiratory pathology was a major contributor to death in 65 infants including 11 infants who died from pulmonary haemorrhage.

Potentially preventable complications of preterm birth such as sepsis, NEC and pulmonary haemorrhage predominate the major contributors to mortality in the GNN 2010 cohort. In order to decrease the rate of these associated deaths, future trials should focus on prophylaxis and therapy optimization strategies for these outcomes.

Fast uncoiling kinetics of F1C pili expressed by uropathogenic Escherichia coli are revealed on a single pilus level using force-measuring optical tweezers

Uropathogenic Escherichia coli (UPEC) express various kinds of organelles, so-called pili or fimbriae, that mediate adhesion to host tissue in the urinary tract through specific receptor-adhesin interactions. The biomechanical properties of these pili have been considered important for the ability of bacteria to withstand shear forces from rinsing urine flows. Force-measuring optical tweezers have been used to characterize individual organelles of F1C type expressed by UPEC bacteria with respect to such properties. Qualitatively, the force-versus-elongation response was found to be similar to that of other types of helix-like pili expressed by UPEC, i.e., type 1, P, and S, with force-induced elongation in three regions, one of which represents the important uncoiling mechanism of the helix-like quaternary structure. Quantitatively, the steady-state uncoiling force was assessed as 26.4 ±1.4 pN, which is similar to those of other pili (which range from 21 pN for S(I) to 30 pN for type 1). The corner velocity for dynamic response (1,400 nm/s) was found to be larger than those of the other pili (400-700 nm/s for S and P pili, and 6 nm/s for type 1). The kinetics were found to be faster, with a thermal opening rate of 17 Hz, a few times higher than S and P pili, and three orders of magnitude higher than type 1. These data suggest that F1C pili are, like P and S pili, evolutionarily selected to primarily withstand the conditions expressed in the upper urinary tract.

The risk of tuberculosis related to tumour necrosis factor antagonist therapies: a TBNET consensus statement

Anti-tumour necrosis factor (TNF) monoclonal antibodies or soluble TNF receptors have become an invaluable treatment against chronic inflammatory diseases, such as rheumatoid arthritis, inflammatory bowel disease and psoriasis. Individuals who are treated with TNF antagonists are at an increased risk of reactivating latent infections, especially tuberculosis (TB). Following TNF antagonist therapy, the relative risk for TB is increased up to 25 times, depending on the clinical setting and the TNF antagonist used. Interferon-γ release assays or, as an alternative in individuals without a history of bacille Calmette-Guérin vaccination, tuberculin skin testing is recommended to screen all adult candidates for TNF antagonist treatment for the presence of latent infection with Mycobacterium tuberculosis. Moreover, paediatric practice suggests concomitant use of both the tuberculin skin test and an interferon-γ release assay, as there are insufficient data in children to recommend one test over the other. Consequently, targeted preventive chemotherapy is highly recommended for all individuals with persistent M. tuberculosis-specific immune responses undergoing TNF antagonist therapy as it significantly reduces the risk of progression to TB. This TBNET consensus statement summarises current knowledge and expert opinions and provides evidence-based recommendations to reduce the TB risk among candidates for TNF antagonist therapy.

99th Dahlem conference on infection, inflammation and chronic inflammatory disorders: lifestyle changes affecting the host-environment interface

In industrialized nations and high-income regions of the world, the decline of infectious diseases is paralleled by an increase in allergic, autoimmune and chronic inflammatory diseases (AACID). Changes in lifestyle in westernized societies, which impact individually and collectively on intestinal microbiota, may – at least in part – account for the AACID pandemic. Many disease genes that contribute to AACID encode pattern recognition and signalling molecules in barrier-associated cells. Interactions between gene products and environmental factors depend highly upon the host's state of maturation, the composition of the skin and gut microflora, and exposure to pollutants, antibiotics and nutrients. Inflammatory stress responses, if regulated appropriately, ensure immunity, health and relative longevity; when they are dysregulated, they can no longer be terminated appropriately and thus precipitate AACID. The 99th Dahlem Conference brought together experts of various disciplines (genetics, evolution biology, molecular biology, structural biology, cell biology, immunology, microbiology, nutrition science, epidemiology and clinical medicine) to discuss the multi-faceted relationships between infection, immunity and inflammation in barrier organs and the development of AACID. In Clinical and Experimental Immunology we are presenting a compilation of background papers that formed the basis of discussions. Controversial viewpoints and gaps in current knowledge were examined and new concepts for prevention and treatment of CID were formulated.

[Pharmacological treatment of fibromyalgia syndrome]

BACKGROUND

An interdisciplinary guideline for the treatment of fibromyalgia syndrome (FMS) and chronic widespread pain (CWP) was developed in cooperation with ten German medical and psychological associations and two patients' self-help organizations.

METHODS

Using the Cochrane Collaboration Reviews (1993-12/2006), Medline (1980-2006), PsychInfo (1966-12/2006), and Scopus (1980-12/ 2006) a systematic literature search was performed, which included all randomised controlled trials (RCT) evaluating multicomponent therapy in FMS and CWP. Levels of evidence were assigned according to the classification system of the Oxford Centre for Evidence-Based Medicine. The strength of recommendation was graded according to the German program for disease management guidelines. Consensus was achieved using a multi-step nominal group procedure.

RESULTS

The short-term use of amitriptyline is strongly recommended (grade A) and the short-term use of fluoxetine und duloxetine is recommended (grade B).

CONCLUSIONS

The recommendations regarding pharmacological treatment of FMS are limited by the short duration of the RCT, the lack of follow-ups and absence of cost-effectiveness studies.

Interferon-gamma-dependent mechanisms of mycobacteria-induced pulmonary immunopathology: the role of angiostasis and CXCR3-targeted chemokines for granuloma necrosis

The mechanisms leading to granuloma caseation, a hallmark of tuberculosis (TB) in humans, are poorly understood. Lung histopathology of C57BL/6 (WT) mice 16 weeks after aerosol infection with Mycobacterium avium strain TMC724 is uniquely characterized by centrally necrotizing granulomas, strongly resembling human TB lesions. However, IFN-gamma-deficient (GKO) and IFN-gamma-receptor-deficient (GRKO) mice did not develop granuloma necrosis following M. avium infection. Comparison of differentially expressed genes in infected WT and GKO lungs by DNA microarray and RNase protection assays revealed that the angiostatic chemokines CXCL9-11 were significantly reduced in GKO mice. In contrast, angiogenic mediators such as angiopoietin and vascular endothelial growth factor, and angiogenic chemokines such as CXCL2, CCL3, and CCL4, remained unchanged or were expressed at higher levels than in infected WT mice, suggesting impaired neovascularization of the granuloma as a possible mechanism for caseation in WT mice. Granuloma vascularization was significantly decreased in central, but not peripheral, areas of granulomas of infected WT compared to GKO mice. In contrast to GRKO mice, WT mice showed signs of severe hypoxia in cells immediately surrounding the necrotic core of granulomas as measured immunohistochemically with a reagent detecting pimonidazole adducts. To test the hypothesis that CXCR3, the common receptor for the angiostatic chemokines CXCL9-11, is involved in granuloma caseation, histomorphology was assessed in M. avium-infected mice deficient for CXCR3 (CXCR3-KO). 16 weeks after infection, these mice developed caseating granulomas similar to WT mice. We conclude that IFN-gamma causes a dysbalance between angiostatic and angiogenic mediators and a concomitant reduction in granuloma vascularization, but that CXCR3-targeted chemokines are not sufficient to induce granuloma necrosis in a mouse model of mycobacteria-induced immunopathology.

Oxygen status of lung granulomas in Mycobacterium tuberculosis-infected mice

It is often assumed that Mycobacterium tuberculosis (Mtb)-induced granulomatous lesions, particularly those undergoing central caseation, are anoxic, and that the survival of Mtb in these lesions requires the integrity of its non-oxidative respiratory pathways. Using the hypoxia marker pimonidazole, we now provide immunohistochemical evidence that in the most frequently used animal model system of inbred mice Mtb-induced granulomas, even after more than one year of aerogenic infection, are not severely hypoxic. In contrast, chronic aerosol infection with M. avium strain TMC724 was associated with hypoxia surrounding necrotizing granuloma centres. Direct measurements of oxygen tension with a flexible microelectrode in mouse lungs chronically infected with Mtb disclosed a wide range of oxygen partial pressures in different parts of the lungs which, however, rarely approached the anoxic conditions consistently found in necrotizing tumours. We further show that an Mtb mutant, defective in nitrate reductase (narG) necessary for survival under anaerobic conditions in vitro, can persist in the lungs of chronically infected mice to a similar extent as wild-type Mtb. These findings have important implications for the use of the mouse model of Mtb infection in developing eradication chemotherapy and for evaluating putative mechanisms of chronic persistence and latency of Mtb.

Solid lipid nanoparticles (SLN)--effects of lipid composition on in vitro degradation and in vivo toxicity

Solid lipid nanoparticles (SLN) composed of two different lipid matrices were produced to assess their in vivo toxicity in mice. Matrix substances were (i) Compritol (glycerol behenate), a physiological lipid with GRAS status (generally recognized as safe [FDA]), and (ii) cetyl palmitate, a less physiological compound. Physicochemical data proved the suitability of SLN batches for intravenous administration. To assess the in vivo toxicity of produced batches, 400 microl SLN dispersion (lipid content 10% [m/m]) were administered to mice via a bolus injection for six times within a period of 20 days (high dose administration). Additionally, a multiple low dose administration was performed with Compritol-SLN as well (200 microl SLN dispersion, lipid content 2.5% [m/m]). Hepatic and splenic tissues were analysed histologically. In vivo results were dependent on the lipid matrix, as well as on the dose administered. For cetyl palmitate containing SLN no pathological results were obtained, while high dosed Compritol containing formulations led to accumulation of the lipid in liver and spleen and subsequently to pathological alterations. These alterations were found to be partially reversible within six weeks after completing intravenous administration. Liver architecture was nearly recovered. In contrast, low dosed Compritol SLN were well tolerated. Lipid accumulation and pathological alterations of high dosed Compritol SLN were attributed to the slow degradation of the Compritol matrix which could be shown by performing in vitro studies in human plasma.

Lipoprotein processing is required for virulence of Mycobacterium tuberculosis

Lipoproteins are a subgroup of secreted bacterial proteins characterized by a lipidated N-terminus, processing of which is mediated by the consecutive activity of prolipoprotein diacylglyceryl transferase (Lgt) and lipoprotein signal peptidase (LspA). The study of LspA function has been limited mainly to non-pathogenic microorganisms. To study a potential role for LspA in the pathogenesis of bacterial infections, we have disrupted lspA by allelic replacement in Mycobacterium tuberculosis, one of the world's most devastating pathogens. Despite the presence of an impermeable lipid outer layer, it was found that LspA was dispensable for growth under in vitro culture conditions. In contrast, the mutant was markedly attenuated in virulence models of tuberculosis. Our findings establish lipoprotein metabolism as a major virulence determinant of tuberculosis and define a role for lipoprotein processing in bacterial pathogenesis. In addition, these results hint at a promising new target for therapeutic intervention, as a highly specific inhibitor of bacterial lipoprotein signal peptidases is available.

Tertiary structure of Staphylococcus aureus cell wall murein

The recently described scaffold model of murein architecture depicts the gram-negative bacterial cell wall as a gel-like matrix composed of cross-linked glycan strands oriented perpendicularly to the plasma membrane while peptide bridges adopt a parallel orientation (B. A. Dmitriev, F. V. Toukach, K. J. Schaper, O. Holst, E. T. Rietschel, and S. Ehlers, J. Bacteriol. 185:3458-3468, 2003). Based on the scaffold model, we now present computer simulation studies on the peptidoglycan arrangement of the gram-positive organism Staphylococcus aureus, which show that the orientation of peptide bridges is critical for the highly cross-linked murein architecture of this microorganism. According to the proposed refined model, staphylococcal murein is composed of glycan and oligopeptide chains, both running in a plane that is perpendicular to the plasma membrane, with oligopeptide chains adopting a zigzag conformation and zippering adjacent glycan strands along their lengths. In contrast to previous models of murein in gram-positive bacteria, this model reflects the high degree of cross-linking that is the hallmark of the staphylococcal cell wall and is compatible with distinguishing features of S. aureus cytokinesis such as the triple consecutive alteration of the division plane orientation and the strictly centripetal mode of septum closure.

Phagocytes transmit Chlamydia pneumoniae from the lungs to the vasculature

Chlamydia pneumoniae, a major cause of community-acquired pneumonia, primarily infects the respiratory tract. Chronic infection of nonrespiratory sites, such as the vascular wall, the brain or blood monocytes, requires evasion from the lungs and spreading via the bloodstream. The cell types involved in dissemination are insufficiently characterised. In this study, New Zealand White rabbits were infected intratracheally with C. pneumoniae, and lung manifestation and systemic dissemination were monitored by polymerase chain reaction and immunohistochemistry. Infection of the lungs was characterised by an early phase dominated by granulocytes and a late phase dominated by alveolar macrophages (AM). Granulocytes, AM and alveolar epithelial cells acted as host cells for chlamydiae, which remained detectable for up to 8 weeks. AM transported the pathogen to the peribronchiolar lymphatic tissue, and subsequently C. pneumoniae entered the spleen and the aorta via dissemination by peripheral blood monocytes. In conclusion, Chlamydia pneumoniae-infected alveolar macrophages transmigrate through the mucosal barrier, and give the pathogen access to the lymphatic system and the systemic circulation. Infected peripheral blood monocytes are the vector system within the bloodstream and transmit the infection to the vascular wall. This is the first description of granulocytes acting as a reservoir for Chlamydia pneumoniae early in infection.

Role of tumour necrosis factor (TNF) in host defence against tuberculosis: implications for immunotherapies targeting TNF

Studies in mouse infection models clearly demonstrate tumour necrosis factor (TNF) to be a critical component of both the antibacterially protective and the inflammatory immune response to Mycobacterium tuberculosis. It is therefore not surprising that treatment of patients-for example, those with rheumatoid arthritis-with biological agents interfering with TNF activity have shown an increased risk of reactivating tuberculosis. However, conceivably, TNF targeting biological agents can be developed that because of their particular mode of action and their specific pharmacodynamics may be less likely to have this side effect.

Update on the pathogenesis of Churg-Strauss syndrome

Churg-Strauss syndrome (CSS) is a rare form of systemic vasculitis occurring in patients with asthma. The cause of CSS is unknown, and yet little data are available regarding its pathogenesis. The presence of a marked tissue- and blood-eosinophilia, as well as secretory products of eosinophils in blood and tissues, implicates a pathogenetic role of eosinophil granulocytes. Prolonged survival of eosinophils due to inhibition of CD95-mediated apoptosis by soluble CD95 seems to contribute to eosinophilia in CSS. Although the mechanisms involved in eosinophil-activation in CSS have not been elucidated, recent data suggest a possible role of T lymphocytes secreting eosinophil-activating cytokines. This review describes the current insights into the pathogenesis of CSS in the light of its putative nature as a type 2 granulomatous disease. Recent clinical, experimental and epidemiologic data regarding the possible role of inflammatory cells and their secretory products, anti neutrophil cytoplasm antibodies (ANCA), epidemiologic factors and anti-asthma treatments are summarized.

Formalpathogenese der tuberkul�sen Gewebsver�nderungen

The histopathological hallmark of infections with Mycobacterium tuberculosis is the development of centrally necrotizing granulomatous lesions. Granulomas are focal accumulations of mononuclear cells in various states of differentiation, in which the local activation of mycobacteria-infected macrophages by specific T cells takes place. On the one hand, this assures efficient containment of mycobacterial growth and demarcation of the infectious focus. On the other hand this is associated with the displacement of and irreversible damage to functionally vital organ tissue (predominantly in the lungs). New insights, emerging from animal models of infection, into the dynamic mechanisms regulating the induction, maintenance and caseation of tuberculous granulomas explain why highly effective anti-inflammatory therapies, e. g. administration of anti-TNF monoclonal antibodies, may result in reactivation of tuberculosis.

Enhanced frequency of a PTPRC (CD45) exon A mutation (77C-->G) in systemic sclerosis

A point mutation in exon A (C to G transversion at position 77) of human PTPRC (CD45) has recently been associated with the development of multiple sclerosis (MS) for at least a subgroup of patients. In the present report, we studied the frequency of the 77C-->G transversion in two other autoimmune diseases namely systemic sclerosis (SSc) and systemic lupus erythematosus (SLE). The mutation was found with significantly enhanced frequency in patients suffering from SSc suggesting that PTPRC could play a role as susceptibility gene not only in MS but also in other autoimmune diseases. Further understanding of the mode of interaction of mutant PTPRC with other susceptibility genes may uncover mechanisms common in various autoimmune disorders.

Alphabeta T cell receptor-positive cells and interferon-gamma, but not inducible nitric oxide synthase, are critical for granuloma necrosis in a mouse model of mycobacteria-induced pulmonary immunopathology

The immunological basis of tuberculin-induced necrosis, known for more than a century as "Koch's phenomenon," remains poorly understood. Aerosol infection in mice with the highly virulent Mycobacterium avium strain TMC724 causes progressive pulmonary pathology strongly resembling caseating necrosis in human patients with tuberculosis. To identify the cellular and molecular mediators causing this pathology, we infected C57BL/6 mice and mice selectively deficient in recombinase activating gene (RAG)-1, alphabeta T cell receptor (TCR), gammadelta TCR, CD4, CD8, beta2-microglobulin, interferon (IFN)-gamma, interleukin (IL)-10, IL-12p35, IL-12p35/p40, or iNOS with M. avium by aerosol and compared bacterial multiplication, histopathology, and respiratory physiology in these mice. The bacterial load in the lung was similarly high in all mouse groups. Pulmonary compliance, as a surrogate marker for granulomatous infiltrations in the lung, deteriorated to a similar extent in all groups of mice, except in alphabeta TCR-knockout (KO) and IL-12-KO mice in which compliance was higher, and in IFN-gamma and inducible nitric oxide synthase-KO mice in which compliance was reduced faster. Progressive caseation of pulmonary granulomas never occurred in alphabeta TCR-KO, IL-12-KO, and IFN-gamma-KO mice and was reduced in CD4-KO mice. In summary, alphabeta TCR(+) cells and IFN-gamma are essential for the development of mycobacteria-induced pulmonary caseous necrosis. In contrast, high mycobacterial load and extensive granulomatous infiltration per se are not sufficient to cause caseation, nor is granuloma necrosis linked to the induction of nitric oxide.

Complex encounters at the macrophage-mycobacterium interface: studies on the role of the mannose receptor and CD14 in experimental infection models with Mycobacterium avium

The initial interactions between mycobacterial cell wall components and receptor structures on the surface of macrophages may be critical in determining the outcome of infection. They may trigger the ingestion and digestion of microorganisms, but they may also promote the intracellular persistence and growth of mycobacteria. Using Mycobacterium avium as a model system, three approaches of different complexities were used to analyse some structural features and some functional consequences of M. avium interacting with the macrophage mannose receptor or CD14, a pattern recognition receptor. Binding specificities of a recombinant, truncated extracellular portion of the mannose receptor were assayed in a novel ELISA-formatted system using viable M. avium cells as ligands. Infection with M. avium strains differing in their virulence were performed in murine bone marrow-derived macrophages and in mice with a targeted deletion of the CD14 gene. These parallel and converging approaches not only help define the molecular basis for understanding early events in the pathogenesis of mycobacterial infections, but are also necessary to ultimately determine the relevance of in vitro findings in the context of actual manifestations of disease in vivo.

Infection of the skin caused by Corynebacterium ulcerans and mimicking classical cutaneous diphtheria

Extrapharyngeal infections caused by Corynebacterium ulcerans have rarely been reported previously, and diphtheria toxin production has usually not been addressed. This case demonstrates that strains of C. ulcerans that produce diphtheria toxin can cause infections of the skin that completely mimic typical cutaneous diphtheria, thereby potentially providing a source of bacteria capable of causing life-threatening diseases in the patient's environment. Therefore, it is recommended to screen wound swabs for coryneform bacteria, identify all isolates, carefully assess possible toxin production, and send questionable strains to a specialist or a reference laboratory.

Public and private self-consciousness and smoking behavior in head and neck cancer patients

Patients who continue to use tobacco following treatment for head and neck cancers are at a greater risk for cancer recurrence and earlier mortality. This study examined the unique effects of public and private self-consciousness and negative affect on smoking behavior in a sample of 40 patients with cancers of the head and neck. Measures of public and private self-consciousness and negative affect were administered and assessments of past and current smoking behavior were obtained. Only public self-consciousness was a significant predictor of continued smoking following oncologic treatment. Specifically, individuals with low levels of public self-consciousness were nearly 13 times more likely to continue smoking compared to those with relatively higher levels of public self-consciousness. This pattern is interpreted in the context of previous theorizing that suggests individuals high in public self-consciousness are more likely to discontinue habitual behavior that is perceived as socially undesirable or incorrect.

Mycobacteria-induced TNF-alpha and IL-10 formation by human macrophages is differentially regulated at the level of mitogen-activated protein kinase activity

The clinical course of mycobacterial infections is linked to the capacity of pathogenic strains to modulate the initial antimycobacterial response of the macrophage. To elucidate some of the mechanisms involved, we studied early signal transduction events leading to cytokine formation by human monocyte-derived macrophages (MDM) in response to clinical isolates of Mycobacterium avium. TNF-alpha production induced by M. avium was inhibited by anti-CD14 mAbs, but not by Abs against the macrophage mannose receptor. Analysis of mitogen-activated protein (MAP) kinase activation (extracellular signal-regulated kinase 1/2, p38, and c-Jun NH(2)-terminal kinase) showed a rapid phosphorylation of all three subfamilies in response to M. avium, which was inhibited by anti-CD14 Abs. Using highly specific inhibitors of p38 (SB203580) and MAP kinase kinase-1 (PD98059), we found that activation of the extracellular signal-regulated kinase pathway, but not of p38, was essential for the M. avium-induced TNF-alpha formation. In contrast, IL-10 production was abrogated by the p38 inhibitor, but not by the MAP kinase kinase-1 inhibitor. In conclusion, M. avium-induced secretion of TNF-alpha and IL-10 by human macrophages is differentially regulated at the level of MAP kinase activity.

Inflammation and lymphocyte activation during mycobacterial infection in the interferon-gamma-deficient mouse

Interferon-gamma is a pivotal cytokine in the protective response to tuberculosis. In its absence rampant bacterial growth results in tissue destruction and death. While macrophage activation is key, this pleiotropic cytokine has other secondary but significant roles. To investigate these roles, both intravenous and aerosol infection of the IFN-gamma gene disrupted (GKO) mouse was performed. For the first time we describe the very similar growth of bacteria, during the initial phase of infection, between control and GKO mice. During this initial phase, however, very different histopathologic consequences between control and GKO mice were observed. Key observations included an early increased accumulation of granulocytes and a much more rapid and pronounced interstitial pneumonia in the GKO mice. As infection developed, GKO mice mounted an antigen-specific response; however, lymphocyte activation was much more rapid in these mice. Of interest is the fact that this increased rapidity occurred prior to significant differences in bacterial number. Taken together these data support a role for IFN-gamma in limiting both initial cellular recruitment and acquired lymphocytic responses to mycobacterial infection. This role may be key in surviving the kind of chronic stimulatory disease caused by Mycobacterium tuberculosis.

Mycobacterium avium infection in CD14-deficient mice fails to substantiate a significant role for CD14 in antimycobacterial protection or granulomatous inflammation

CD14 is a pattern-recognition receptor implicated in the inflammatory response to microbial components such as lipopolysaccharide, peptidoglycan and lipoarabinomannan. In this work, we made use of CD14-deficient (CD14-/-) mice to evaluate the relative importance of CD14 in response to infection with viable, intact cells of Mycobacterium avium in vitro and in vivo. Following co-incubation of either bone marrow-derived macrophages (Mphi) or thioglycollate-elicited peritoneal Mphi from CD14-/- mice with viable M. avium, tumour necrosis factor (TNF) production was significantly reduced and delayed compared to TNF secretion by infected CD14+/+ Mphi. However, following intravenous infection with a M. avium strain of either high virulence (TMC724) or intermediate virulence (SE01), there was no difference in the bacterial loads of lungs, livers or spleens at 3, 5 and 8 weeks postinfection in CD14-/- mice when compared with syngeneic CD14+/+ mice. At these time-points, TNF and interferon-gamma (IFN-gamma) mRNA expression in the liver was similar in infected CD14+/+ and CD14-/- mice, and granuloma formation and expression of inducible nitric oxide synthase within granuloma Mphi was the same in both mouse groups. In conclusion, although the absence of CD14 results in significantly reduced and delayed TNF production in response to stimulation with M. avium in vitro, there is no evidence that CD14 plays a significant role in either the antibacterial defence or the chronic granulomatous reaction to M. avium infection in vivo.

Differential requirement for interferon-gamma to restrict the growth of or eliminate some recently identified species of nontuberculous mycobacteria in vivo

In recent years, a number of newly identified species of the genus Mycobacterium (M.) have been isolated from tissues of both immunocompetent and immunocompromised patients, e.g. M. celatum, M. intermedium, M. interjectum, M. bohemicum, M. conspicuum, M. confluentis, M. heidelbergense, M. lentiflavum, and M. branderi. Little is known about their in vivo virulence characteristics and the host factors predisposing to infection with these strains. In an effort to elucidate the pathogenesis of these nontuberculous mycobacterial species, BALB/c and syngeneic IFNgamma-deficient (GKO) mice were intravenously infected with 106 colony forming units of each of these species, and bacterial growth in infected organs and the development of splenomegaly and granulomatous liver lesions were examined for a period of 3 months. Based on their in vivo virulence, mycobacterial strains could be divided into three major groups: (i) Most species examined either grew progressively or persisted at plateau levels in the livers and spleens of immunocompetent mice, and their growth was increased in GKO mice. (ii) M. heidelbergense, M. intermedium and another species not officially accorded separate taxonomical status were eliminated in BALB/c mice, but persisted in GKO mice. (iii) M. confluentis, M. lentiflavum and another novel species were eradicated even in the absence of IFNgamma. Nontuberculous mycobacterial species differed widely in their capacity to induce splenomegaly and lymphadenopathy in GKO mice. In conclusion, IFNgamma is a crucial determinant of infection outcome with most, but not all opportunistic mycobacterial species.