Prognostic markers for the clinical course in the blood of patients with SARS-CoV-2 infection.

BACKGROUND: The presentation of peptides and the subsequent immune response depend on the MHC characteristics and influence the specificity of the immune response. Several studies have found an association between HLA variants and differential COVID-19 outcomes and have shown that HLA genotypes are associated with differential immune responses against SARS-CoV-2, particularly in severely ill patients. Information, whether HLA haplotypes are associated with the severity or length of the disease in moderately diseased individuals is absent. METHODS: Next-generation sequencing-based HLA typing was performed in 303 female and 231 male non-hospitalized North Rhine Westphalian patients infected with SARS-CoV2 during the first and second wave. For HLA-Class I, we obtained results from 528 patients, and for HLA-Class II from 531. In those patients, who became ill between March 2020 and January 2021, the 22 most common HLA-Class I (HLA-A, -B, -C) or HLA-Class II (HLA -DRB1/3/4, -DQA1, -DQB1) haplotypes were determined. The identified HLA haplotypes as well as the presence of a CCR5Δ32 mutation and number of O and A blood group alleles were associated to disease severity and duration of the disease. RESULTS: The influence of the HLA haplotypes on disease severity and duration was more pronounced than the influence of age, sex, or ABO blood group. These associations were sex dependent. The presence of mutated CCR5 resulted in a longer recovery period in males. CONCLUSION: The existence of certain HLA haplotypes is associated with more severe disease.

Influence of a Calcium Phosphate Coating (BONIT®) on the Proliferation and Differentiation Potential of Human Mesenchymal Stroma Cells in the Early Phase of Bone Healing.

When implanting osteosynthetic materials or orthopedic implants, the surface condition plays a decisive role for mid- to long-term osseointegration. BONIT®, an electrochemically produced calcium phosphate (CaP) coating, has been used in the surface refinement of implants since 1995. More than 3.5 million coated implants have been successfully placed so far. BONIT® has thus been able to demonstrate clinical success. However, due to its surface properties and solubility, and the resulting difficulty in culturing cells, there are no in vitro studies investigating its influence at the molecular level, particularly on bone metabolism. In a first step, the cells from a total of ten donors were seeded separately on four different surfaces: 1. a pure corundum-blasted titanium surface (CELLTex®, CT), 2. CT with additional BONIT® coating (CT + B), 3. a hydroxyapatite-blasted titanium surface (DUOTex®, DT), 4. DT with additional BONIT® coating (DT + B). In a second step, the cells were grown for 48 h. The proliferation behavior and differentiation potential of hMSCs were investigated at three consecutive time points (12 h, 24 h and 48 h) by quantifying the mRNA expression of ten important differentiation markers using quantitative real-time polymerase chain reaction (qRT-PCR). We were able to show that BONIT® has an influence on the early proliferation and differentiation behavior of hMSCs in patients of all age groups. The additional BONIT® coating on CELLTex® or DUOTex® led to a defined mRNA expression pattern for the investigated factors: a tendency towards a higher expression rate with coating present could be found for bone morphogenetic protein 2 (BMP2), osteopontin (OPN), osteocalcin (OC), receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG). A similar or lower expression rate was detected for runt-related transcription factor 2 (RUNX2), alpha-1 type I collagen (COL1A1), alkaline phosphatase (AP), osteonectin (ON) and insulin-like growth factor I (IGF1). We have developed a new method that allows the cultivation of human mesenchymal stromal cells (hMSCs) on the soluble coating BONIT® for gene expression analysis. BONIT® has a significant influence on the proliferation and differentiation behavior of human mesenchymal stroma cells. This study describes a defined gene expression pattern of bone metabolism that may help to understand the influence of this CaP coating on the early phase of implant osseointegration.

Association of HLA genotypes, AB0 blood type and chemokine receptor 5 mutant CD195 with the clinical course of COVID-19.

BACKGROUND: COVID-19, the pandemic disease caused by infection with SARS-CoV-2, may take highly variable clinical courses, ranging from symptom-free and pauci-symptomatic to fatal disease. The goal of the current study was to assess the association of COVID-19 clinical courses controlled by patients' adaptive immune responses without progression to severe disease with patients' Human Leukocyte Antigen (HLA) genetics, AB0 blood group antigens, and the presence or absence of near-loss-of-function delta 32 deletion mutant of the C-C chemokine receptor type 5 (CCR5). PATIENT AND METHODS: An exploratory observational study including 157 adult COVID-19 convalescent patients was performed with a median follow-up of 250 days. The impact of different HLA genotypes, AB0 blood group antigens, and the CCR5 mutant CD195 were investigated for their role in the clinical course of COVID-19. In addition, this study addressed levels of severity and morbidity of COVID-19. The association of the immunogenetic background parameters were further related to patients' humoral antiviral immune response patterns by longitudinal observation. RESULTS: Univariate HLA analyses identified putatively protective HLA alleles (HLA class II DRB1*01:01 and HLA class I B*35:01, with a trend for DRB1*03:01). They were associated with reduced durations of disease instead decreased (rather than increased) total anti-S IgG levels. They had a higher virus neutralizing capacity compared to non-carriers. Conversely, analyses also identified HLA alleles (HLA class II DQB1*03:02 und HLA class I B*15:01) not associated with such benefit in the patient cohort of this study. Hierarchical testing by Cox regression analyses confirmed the significance of the protective effect of the HLA alleles identified (when assessed in composite) in terms of disease duration, whereas AB0 blood group antigen heterozygosity was found to be significantly associated with disease severity (rather than duration) in our cohort. A suggestive association of a heterozygous CCR5 delta 32 mutation status with prolonged disease duration was implied by univariate analyses but could not be confirmed by hierarchical multivariate testing. CONCLUSION: The current study shows that the presence of HLA class II DRB1*01:01 and HLA class I B*35:01 is of even stronger association with reduced disease duration in mild and moderate COVID-19 than age or any other potential risk factor assessed. Prospective studies in larger patient populations also including novel SARS-CoV-2 variants will be required to assess the impact of HLA genetics on the capacity of mounting protective vaccination responses in the future.

Informed consent and informed intervention: SARS-CoV-2 vaccinations not just call for disclosure of newly emerging safety data but also for hypothesis generation and testing.

BACKGROUND: COVID-19 infection is a major threat to patients and health care providers around the world. One solution is the vaccination against SARS-CoV-2. METHODS: We performed a comprehensive query of the latest publications on the prevention of viral infections including the recent vaccination program and its side effects. RESULTS: The situation is evolving rapidly and there is no reasonable alternative to population-scale vaccination programs as currently enrolled. CONCLUSION: Therefore, regulatory authorities should consider supplementing their conventional mandate of post-approval pharmacovigilance, which is based on the collection, assessment, and regulatory response to emerging safety findings.

Delayed skin reaction after mRNA-1273 vaccine against SARS-CoV-2: a rare clinical reaction.

BACKGROUND: The coronavirus disease 2019 (COVID-19) is associated with a wide clinical spectrum of skin manifestations, including urticarial, vesicular, vasculitic and chilblain-like lesions. Recently, delayed skin reactions have been reported in 1% individuals following mRNA vaccination against SARS-CoV-2. The exact pathophysiology and the risk factors still remain unclear. PATIENTS AND METHODS: 6821 employees and patients were vaccinated at our institutions between February and June 2021. Every patient received two doses of the mRNA-1273 vaccine in our hospitals, and reported back in case of any side effects which were collected in our hospital managed database. RESULTS: Eleven of 6821 vaccinated patients (0.16%) developed delayed skin reactions after either the first or second dose of the mRNA-1273 vaccine against SARS-CoV-2. Eight of 11 patients (73%) developed a rash after the first dose, while in 3/11 (27%), the rash occurred after the second dose. More females (9/11) were affected. Four of 11 patients required antihistamines, with two needing additional topical steroids. All the cutaneous manifestations resolved within 14 days. None of the skin reactions after the first dose of the vaccine prevented the administration of the second dose. There were no long-term cutaneous sequelae in any of the affected individuals. CONCLUSION: Our data suggests that skin reactions after the use of mRNA-1273 vaccine against SARS-CoV-2 are possible, but rare. Further studies need to be done to understand the pathophysiology of these lesions.

Neutrophil-Derived Tumor Necrosis Factor Drives Fungal Acute Lung Injury in Chronic Granulomatous Disease.

Chronic granulomatous disease (CGD) results from deficiency of nicotinamide adenine dinucleotide phosphate(NADPH) oxidase and impaired reactive oxygen species (ROS) generation. This leads to impaired killing of Aspergillus and, independently, a pathologic hyperinflammatory response to the organism. We hypothesized that neutrophil-derived ROS inhibit the inflammatory response to Aspergillus and that acute lung injury in CGD is due to failure of this regulation. Mice with gp91phox deficiency, the most common CGD mutation, had more severe lung injury, increased neutrophilinfiltration, and increased lung tumor necrosis factor (TNF) after Aspergillus challenge compared with wild-types. Neutrophils were surprisingly the predominant source of TNF in gp91phox-deficient lungs. TNF neutralization inhibited neutrophil recruitment in gp91phox-deficient mice and protected from lung injury. We propose that, in normal hosts, Aspergillus stimulates TNF-dependent neutrophil recruitment to the lungs and neutrophil-derived ROS limit inflammation. In CGD, in contrast, recruited neutrophils are the dominant source of TNF, promoting further neutrophil recruitment in a pathologic positive-feedback cycle, resulting in progressive lung injury.

Dose- and time-dependent effects of hyaluronidase on structural cells and the extracellular matrix of the skin.

INTRODUCTION: Hyaluronic acid (hyaluronan; HA) is an essential component of the extracellular matrix (ECM) of the skin. The HA-degrading enzyme hyaluronidase (HYAL) is critically involved in the HA-metabolism. Yet, only little information is available regarding the skin's HA-HYAL interactions on the molecular and cellular levels. OBJECTIVE: To analyze the dose- and time-dependent molecular and cellular effects of HYAL on structural cells and the HA-metabolism in the skin. MATERIALS AND METHODS: Chip-based, genome-wide expression analyses (Affymetrix® GeneChip PrimeView™ Human Gene Expression Array), quantitative real-time PCR analyses, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (DAB), and in vitro wound healing assays were performed to assess dose-dependent and time-kinetic effects of HA and HYAL (bovine hyaluronidase, Hylase "Dessau") on normal human dermal fibroblasts (NHDF), primary human keratinocytes in vitro and human skin samples ex vivo. RESULTS: Genome-wide expression analyses revealed an upregulation of HA synthases (HAS) up to 1.8-fold change in HA- and HYAL-treated NHDF. HA and HYAL significantly accelerated wound closure in an in vitro model for cutaneous wound healing. HYAL induced HAS1 and HAS2 mRNA gene expression in NHDF. Interestingly, low concentrations of HYAL (0.015 U/ml) resulted in a significantly higher induction of HAS compared to moderate (0.15 and 1.5 U/ml) and high concentrations (15 U/ml) of HYAL. This observation corresponded to increased concentrations of HA measured by ELISA in conditioned supernatants of HYAL-treated NHDF with the highest concentrations observed for 0.015 U/ml of HYAL. Finally, immunohistochemical analysis of human skin samples incubated with HYAL for up to 48 h ex vivo demonstrated that low concentrations of HYAL (0.015 U/ml) led to a pronounced accumulation of HA, whereas high concentrations of HYAL (15 U/ml) reduced dermal HA-levels. CONCLUSION: HYAL is a bioactive enzyme that exerts multiple effects on the HA-metabolism as well as on the structural cells of the skin. Our results indicate that HYAL promotes wound healing and exerts a dose-dependent induction of HA-synthesis in structural cells of the skin. Herein, interestingly the most significant induction of HAS and HA were observed for the lowest concentration of HYAL.

Clinical Applications of Hyaluronidase.

Hyaluronidases are enzymes that degrade hyaluronic acid, which constitutes an essential part of the extracellular matrix. Initially discovered in bacteria, hyaluronidases are known to be widely distributed in nature and have been found in many classes including insects, snakes, fish and mammals. In the human, six different hyaluronidases, HYAL1-4, HYAL-P1 and PH-20, have been identified. PH-20 exerts the strongest biologic activity, is found in high concentrations in the testicles and can be localized on the head and the acrosome of human spermatozoa. Today, animal-derived bovine or ovine testicular hyaluronidases as well as synthetic hyaluronidases are clinically applied as adjuncts to increase the bioavailability of drugs, for the therapy of extravasations, or for the management of complications associated with the aesthetic injection of hyaluronic acid-based fillers. Further applications in the fields of surgery, aesthetic medicine, immunology, oncology, and many others can be expected for years to come. Here, we give an overview over the molecular and cellular mode of action of hyaluronidase and the hyaluronic acid metabolism, as well as over current and potential future clinical applications of hyaluronidase.

A noncanonical role for the engulfment gene ELMO1 in neutrophils that promotes inflammatory arthritis.

Rheumatoid arthritis is characterized by progressive joint inflammation and affects ~1% of the human population. We noted single-nucleotide polymorphisms (SNPs) in the apoptotic cell-engulfment genes ELMO1, DOCK2, and RAC1 linked to rheumatoid arthritis. As ELMO1 promotes cytoskeletal reorganization during engulfment, we hypothesized that ELMO1 loss would worsen inflammatory arthritis. Surprisingly, Elmo1-deficient mice showed reduced joint inflammation in acute and chronic arthritis models. Genetic and cell-biology studies revealed that ELMO1 associates with receptors linked to neutrophil function in arthritis and regulates activation and early neutrophil recruitment to the joints, without general inhibition of inflammatory responses. Further, neutrophils from the peripheral blood of human donors that carry the SNP in ELMO1 associated with arthritis display increased migratory capacity, whereas ELMO1 knockdown reduces human neutrophil migration to chemokines linked to arthritis. These data identify 'noncanonical' roles for ELMO1 as an important cytoplasmic regulator of specific neutrophil receptors and promoter of arthritis.

Tensiomyography parameters and serum biomarkers after eccentric exercise of the elbow flexors.

PURPOSE: The tensiomyography (TMG) technique is increasingly used to determine muscle contractile properties in exercise and injury management. The present study investigated the informative value of TMG parameters in correlation with commonly used (creatine kinase, CK; myoglobin, Mb) and novel candidate biomarkers of muscle damage (heart-type fatty acid-binding protein, h-FABP; high-mobility group box 1, HMGB1). METHODS: Ten untrained men performed 6 × 10 eccentric contractions of the elbow flexors at 110% of the concentric one repetition maximum. CK, Mb, h-FABP, HMGB1, arm circumference, pain and TMG data, including maximal displacement (Dm) and temporal outcomes as the contraction time (Tc), sustained time (Ts), delay time (Td), and relaxation time (Tr), were assessed pre-exercise, post-exercise, 20 min, 2 h and on the consecutive 3 days post-exercise. RESULTS: CK and h-FABP significantly increased beginning at 24 h, Mb already increased at 2 h (p < 0.05). HMGB1 was only increased immediately post-exercise (p = 0.02). Tc and Td remained unchanged, whereas Ts and Tr were significantly slower beginning at 24 h (p < 0.05). Dm was decreased within the first 24 h and after 72 h (p < 0.01). The % change from pre-exercise correlated for Dm with CK, Mb, and h-FABP the highest at 48 h (r = - 0.95, - 0.87 and - 0.79; p < 0.01) and for h-FABP with CK and Mb the highest at 24 h (r = 0.96 and 0.94, for all p < 0.001). CONCLUSION: This study supports the correlation of TMG parameters with muscle damage markers after eccentric exercise. Therefore, TMG could represent a non-invasive and cost effective alternative to quantify the degree of muscle damage after exercise interventions.

Ingenol mebutate induces a tumor cell-directed inflammatory response and antimicrobial peptides thereby promoting rapid tumor destruction and wound healing.

BACKGROUND: Ingenol mebutat (IM)-gel is effective for the topical treatment of epithelial tumors, including actinic keratoses (AKs) or anogenital warts (AGW). AK patients treated with IM develop intensified inflammatory reactions on sights of prior clinical visible or palpable AKs as compared to the surrounding actinically damaged skin, suggesting the induction of a tumor cell-directed inflammation. AGW patients treated with IM develop even stronger inflammatory reactions with large erosions, suggesting a directed inflammatory response against HPV-infected keratinocytes. Of note, even widespread erosions heal very fast without any superinfections. Here, we set out to elucidate underlying molecular and cellular mechanisms of these clinical observations. METHODS: The effects of IM (10-9-10-5 M) on the expression and translation of a comprehensive set of chemokines (CXCL1, CXCL8, CXCL9, CXCL10, CXCL11, CXCL14, CCL2, CCL5, CCL20, CCL27) and antimicrobial peptides (AMP) (HBD1, HBD2, HBD3, LL37, RNase7) were analyzed in primary human epithelial keratinocytes (HEK) and a set of epithelial cancer cell lines by RT-qPCR and ELISA in vitro. To study the possible effects of different concentrations of IM on migratory, respectively wound healing responses, an in vitro scratch assay was conducted on HEK. RESULTS: Ingenol mebutat significantly and dose-dependently induced the expression of proinflammatory chemokines (CXCL8, CCL2) and AMP (RNase7, HBD3) in HEK and epithelial cancer cell lines. A significantly stronger induction of CXCL8 and CCL2 was observed in our tested tumor cells as compared to HEK. We did not observe any significant effect of IM on HEK migration, respectively wound healing responses in vitro for any tested concentration (10-9, 10-8, 10-6 M) except 10-7 M, which induced a significant inhibition. CONCLUSIONS: Our data suggest that tumor cells are more susceptible to IM as compared to differentiated HEK. This is evident by a stronger IM-mediated induction of proinflammatory chemokines in tumor cells, which may result in a tumor cell-directed inflammatory response and rapid tumor destruction. In addition, IM induces AMP in keratinocytes and seems not to severely interfere with keratinocyte migration, which contributes to a fast and uncomplicated wound healing. Surprising is a selective inhibition of keratinocyte migration by IM at the concentration of 10-7 M pointing to very dose depending biological effects, induced by IM.

Standardized in vitro analysis of the degradability of hyaluronic acid fillers by hyaluronidase.

BACKGROUND: Hyaluronidase is a hyaluronic acid (HA) metabolizing enzyme, which is approved as an adjuvant for infiltration anesthesia. The "off-label" use of hyaluronidase is regarded as gold standard for the management of HA-filler-associated complications. Yet, up to date there are only few studies that have systematically assessed the degradability of different HA-fillers by hyaluronidase. OBJECTIVE: To analyze the interactions of HA-fillers and hyaluronidase in a time-dependent manner using a novel standardized in vitro approach. METHODS: Comparable HA-fillers, Belotero Balance Lidocaine (BEL; Merz), Emervel classic (EMV; Galderma) and Juvederm Ultra 3 (JUV; Allergan), were incubated with a fluorescent dye and bovine hyaluronidase (HYAL; Hylase "Dessau", Riemser) or control (NaCl) and monitored by time-lapse videomicroscopy. The degradation of HA-fillers was assessed as decrease in fluorescence intensity of HA-filler plus hyaluronidase vs. HA-filler plus control, quantified by computer-assisted image analysis (ImageJ). RESULTS: Hyaluronidase showed a significant degradation of the HA-fillers BEL and EMV. Degradation was measurable at 5 h (BEL) and 7 h (EMV), respectively; significance was reached at 14 h (BEL) and 13 h (EMV). No effect of hyaluronidase was observed for JUV. CONCLUSION: Time-lapse microscopy enables systematically, standardized, comparative in vitro analyses of the interactions of hyaluronidase and HA-fillers.

Chemokine ligand-receptor interactions critically regulate cutaneous wound healing.

BACKGROUND: Wound healing represents a dynamic process involving directional migration of different cell types. Chemokines, a family of chemoattractive proteins, have been suggested to be key players in cell-to-cell communication and essential for directed migration of structural cells. Today, the role of the chemokine network in cutaneous wound healing is not fully understood. Unraveling the chemokine-driven communication pathways in this complex process could possibly lead to new therapeutic strategies in wound healing disorders. METHODS: We performed a systematic, comprehensive time-course analysis of the expression and function of a broad variety of cytokines, growth factors, adhesion molecules, matrixmetalloproteinases and chemokines in a murine cutaneous wound healing model. RESULTS: Strikingly, chemokines were found to be among the most highly regulated genes and their expression was found to coincide with the expression of their matching receptors. Accordingly, we could show that resting and activated human primary keratinocytes (CCR3, CCR4, CCR6, CXCR1, CXCR3), dermal fibroblasts (CCR3, CCR4, CCR10) and dermal microvascular endothelial cells (CCR3, CCR4, CCR6, CCR8, CCR9, CCR10, CXCR1, CXCR2, CXCR3) express a distinct and functionally active repertoire of chemokine receptors. Furthermore, chemokine ligand-receptor interactions markedly improved the wound repair of structural skin cells in vitro. CONCLUSION: Taken together, we here present the most comprehensive analysis of mediators critically involved in acute cutaneous wound healing. Our findings suggest therapeutic approaches for the management of wound closure by targeting the chemokine network.

Draft Genome Sequences of Phenotypically Distinct Janthinobacterium sp. Isolates Cultured from the Hudson Valley Watershed.

Investigation of the Hudson Valley watershed reveals many violacein-producing bacteria. These are of interest for their biotherapeutic potential in treating chytrid infections of amphibians. The draft whole-genome sequences for seven Janthinobacterium isolates with a variety of phenotypes are provided in this study.

Hepcidin-mediated iron sequestration protects against bacterial dissemination during pneumonia.

Gram-negative pneumonia is a dangerous illness, and bacterial dissemination to the bloodstream during the infection is strongly associated with death. Antibiotic resistance among the causative pathogens has resulted in diminishing treatment options against this infection. Hepcidin is the master regulator of extracellular iron availability in vertebrates, but its role in the context of host defense is undefined. We hypothesized that hepcidin-mediated depletion of extracellular iron during Gram-negative pneumonia protects the host by limiting dissemination of bacteria to the bloodstream. During experimental pneumonia, hepcidin was induced in the liver in an IL-6-dependent manner and mediated a rapid decline in plasma iron. In contrast, hepcidin-deficient mice developed a paradoxical increase in plasma iron during infection associated with profound susceptibility to bacteremia. Incubation of bacteria with iron-supplemented plasma enhanced bacterial growth in vitro, and systemic administration of iron to WT mice similarly promoted increased susceptibility to bloodstream infection. Finally, treatment with a hepcidin analogue restored hypoferremia in hepcidin-deficient hosts, mediated bacterial control, and improved outcomes. These data show hepcidin induction during pneumonia to be essential to preventing bacterial dissemination by limiting extracellular iron availability. Hepcidin agonists may represent an effective therapy for Gram-negative infections in patients with impaired hepcidin production or signaling.

Mechanisms underpinning protection against eccentric exercise-induced muscle damage by ischemic preconditioning.

Eccentric exercise training is effective for increasing muscle mass and strength, and improving insulin sensitivity and blood lipid profiles. However, potential muscle damage symptoms such as prolonged loss of muscle function and delayed onset of muscle soreness may restrict the use of eccentric exercise, especially in clinical populations. Therefore, strategies to reduce eccentric exercise-induced muscle damage (EIMD) are necessary, and an extensive number of scientific studies have tried to identify potential intervention modalities to perform eccentric exercises without adverse effects. The present paper is based on a narrative review of current literature, and provides a novel hypothesis by which an ischemic preconditioning (IPC) of the extremities may reduce EIMD. IPC consists of an intermittent application of short-time non-lethal ischemia to an extremity (e.g. using a tourniquet) followed by reperfusion and was discovered in clinical settings in an attempt to minimize inflammatory responses induced by ischemia and ischemia-reperfusion-injury (I/R-Injury) during surgery. The present hypothesis is based on morphological and biochemical similarities in the pathophysiology of skeletal muscle damage during clinical surgery and EIMD. Even though the primary origin of stress differs between I/R-Injury and EIMD, subsequent cellular alterations characterized by an intracellular accumulation of Ca2+, an increased production of reactive oxygen species or increased apoptotic signaling are essential elements for both. Moreover, the incipient immune response appears to be similar in I/R-Injury and EIMD, which is indicated by an infiltration of leukocytes into the damaged soft-tissue. Thus far, IPC is considered as a potential intervention strategy in the area of cardiovascular or orthopedic surgery and provides significant impact on soft-tissue protection and downregulation of undesired excessive inflammation induced by I/R-Injury. Based on the known major impact of IPC on skeletal muscle physiology and immunology, the present paper aims to illustrate the potential protective effects of IPC on EIMD by discussing possible underlying mechanisms.

Mechanisms of skin aging induced by EGFR inhibitors.

BACKGROUND: The mechanisms of skin aging have not been completely elucidated. Anecdotal data suggests that EGFR inhibition accelerates aging-like skin changes. OBJECTIVE: The objective of the study was to evaluate the clinical characteristics and investigate the cellular and molecular mechanisms underlying skin changes associated with the use of EFGRIs. PATIENTS AND METHODS: Patients during prolonged treatment with EGFRIs (>3 months) were analyzed for aging-like skin changes. Baseline EGFR expression was compared in young (<25 years old) vs. old (> 65 years old) skin. In addition, the regulation of extracellular matrix, senescence-associated genes, and cell cycle status was measured in primary human keratinocytes treated with erlotinib in vitro. RESULTS: There were progressive signs of skin aging, including xerosis cutis, atrophy, rhytide formation, and/or actinic purpura in 12 patients. Keratinocytes treated with erlotinib in vitro showed a significant down-modulation of hyaluronan synthases (HAS2 and HAS3), whereas senescence-associated genes (p21, p53, IL-6, maspin) were upregulated, along with a G1 cell cycle arrest and stronger SA ß-Gal activity. There was significantly decreased baseline expression in EGFR density in aged skin, when compared to young controls. CONCLUSIONS: EGFR inhibition results in molecular alterations in keratinocytes that may contribute to the observed skin aging of patients treated with respective targeted agents.

M-CSF Mediates Host Defense during Bacterial Pneumonia by Promoting the Survival of Lung and Liver Mononuclear Phagocytes.

Gram-negative bacterial pneumonia is a common and dangerous infection with diminishing treatment options due to increasing antibiotic resistance among causal pathogens. The mononuclear phagocyte system is a heterogeneous group of leukocytes composed of tissue-resident macrophages, dendritic cells, and monocyte-derived cells that are critical in defense against pneumonia, but mechanisms that regulate their maintenance and function during infection are poorly defined. M-CSF has myriad effects on mononuclear phagocytes but its role in pneumonia is unknown. We therefore tested the hypothesis that M-CSF is required for mononuclear phagocyte-mediated host defenses during bacterial pneumonia in a murine model of infection. Genetic deletion or immunoneutralization of M-CSF resulted in reduced survival, increased bacterial burden, and greater lung injury. M-CSF was necessary for the expansion of lung mononuclear phagocytes during infection but did not affect the number of bone marrow or blood monocytes, proliferation of precursors, or recruitment of leukocytes to the lungs. In contrast, M-CSF was essential to survival and antimicrobial functions of both lung and liver mononuclear phagocytes during pneumonia, and its absence resulted in bacterial dissemination to the liver and hepatic necrosis. We conclude that M-CSF is critical to host defenses against bacterial pneumonia by mediating survival and antimicrobial functions of mononuclear phagocytes in the lungs and liver.

Laser assisted Drug Delivery: Grundlagen und Praxis.

Die topische Applikation von Wirkstoffen ist eine zentrale Therapieoption der Dermatologie. Allerdings mindert die effektive Barrierefunktion der Haut die Bioverfügbarkeit der meisten Externa. Fraktionierte ablative Laser stellen ein innovatives Verfahren dar, um die epidermale Barriere standardisiert, kontaktfrei zu überwinden. Die Bioverfügbarkeit im Anschluss applizierter Externa wird im Sinne einer laser assisted drug delivery (LADD) signifikant gesteigert. Das Prinzip der LADD wird bereits in einigen Bereichen der Dermatologie erfolgreich eingesetzt. Die vorliegende Übersichtsarbeit soll einen Überblick über die aktuellen aber auch perspektivischen Einsatzmöglichkeiten der LADD bieten.