[Invasive Streptococcal infections - an interdisciplinary challenge]. / Invasive Streptokokken-Infektionen ­ eine interdisziplinäre Herausforderung.

HISTORY AND CLINICAL FINDINGS: We report on a 34-year-old female patient and a 50-year-old male patient, both of whom were admitted to our emergency department with severe septic conditions. MEDICAL EXAMINATIONS: Both patients were resuscitated and exhibited clinical as well as laboratory evidence of a severe bacterial infection. DIAGNOSIS: Both patients had an invasive infection with Group A Streptococcus. The female patient had a Streptococcal sepsis with severe pneumonia, while the male patient had a Streptococcus-induced necrotizing fasciitis of the upper extremity. THERAPY AND COURSE: While the female patient unfortunately died in the emergency department`s resuscitation room despite all intensive medical treatments, the male patient survived after prompt surgical therapy and an extended stay in the intensive care unit. CONCLUSION: Patients with invasive infections caused by Group A Streptococcus can deteriorate rapidly clinically. Prompt diagnosis and initiation of often interdisciplinary treatment are important. Nevertheless, these conditions can be fatal.

[Motives of patients presenting independently at the emergency department-a prospective monocentric observational study]. / Beweggründe von Patienten, die sich selbständig in der Notaufnahme vorstellen ­ eine prospektive monozentrische Beobachtungsstudie.

BACKGROUND: In the ongoing professional, societal, and political discussion, the hypothesis is repeatedly put forward that a large portion of patients who independently visit the emergency department could also be treated in other care settings such as by a general practitioner, the statutory medical on-call service, or in emergency clinics. Various reasons are cited for why these alternative care settings are not utilized in these cases. OBJECTIVES: This study investigates the motives of patients who presented independently at the emergency department, as well as the socio-demographic parameters of this study cohort. MATERIALS AND METHODS: The survey was carried out as part of a prospective monocentric observational study of internal medicine patients at a university emergency department. RESULTS: A total of 1086 patients were included in the study. In total, 33% of the study participants visited the emergency department based on a physician's recommendation or referral instead of opting for an alternative care option. The main reason for visiting the emergency department was the subjectively assessed urgency of their symptoms. Among the patients who presented independently at the emergency department, 28% required further inpatient care during the course of treatment. Awareness of alternative care pathways, such as utilizing emergency medical services, seeking care from the statutory medical on-call service, or visiting an emergency clinic, was low. CONCLUSIONS: Emergency departments remain an important point of contact for patients who present there independently, without being brought by emergency medical services. The motives behind why patients choose a visit to the emergency department over treatment in an alternative care setting vary. If alternatives are to be used instead of emergency departments, structures first need to be established or expanded.

[Vasculitis oft the skin after cocaine use]. / Vaskulitis der Haut nach Kokainkonsum.

HISTORY AND CLINICAL FINDINGS: A 20-years-old patient presented himself to our emergency room with extensive and extremely painful purpura with necrotizing spots and blisters, especially on the lower extremities, but also on the arms, trunk and ears. There was a pre-existing use of cocaine. MEDICAL EXAMINATIONS: Laboratory tests showed increased signs of inflammation as well as an increase in proteinase 3- and myeloperoxidase-ANCA (Anti-neutrophil cytoplasmatic antibody). DIAGNOSIS: In combination with the medical history, the clinical findings, and the laboratory values, vasculitis of the skin after cocaine use was revealed. THERAPY AND COURSE: Under therapy with steroids and cocaine abstinence, there was a regression of the changes. CONCLUSION: Vasculitis is a serious complication of cocaine use.

Medical and cardio-vascular emergency department visits during the COVID-19 pandemic in 2020: is there a collateral damage? A retrospective routine data analysis.

BACKGROUND: In this retrospective routine data analysis, we investigate the number of emergency department (ED) consultations during the COVID-19 pandemic of 2020 in Germany compared to the previous year with a special focus on numbers of myocardial infarction and acute heart failure. METHODS: Aggregated case numbers for the two consecutive years 2019 and 2020 were obtained from 24 university hospitals and 9 non-university hospitals in Germany and assessed by age, gender, triage scores, disposition, care level and by ICD-10 codes including the tracer diagnoses myocardial infarction (I21) and heart failure (I50). RESULTS: A total of 2,216,627 ED consultations were analyzed, of which 1,178,470 occurred in 2019 and 1,038,157 in 2020. The median deviation in case numbers between 2019 and 2020 was - 14% [CI (- 11)-(- 16)]. After a marked drop in all cases in the first COVID-19 wave in spring 2020, case numbers normalized during the summer. Thereafter starting in calendar week 39 case numbers constantly declined until the end of the year 2020. The decline in case numbers predominantly concerned younger [- 16%; CI (- 13)-(- 19)], less urgent [- 18%; CI (- 12)-(- 22)] and non-admitted cases [- 17%; CI (- 13)-(- 20)] in particular during the second wave. During the entire observation period admissions for chest pain [- 13%; CI (- 21)-2], myocardial infarction [- 2%; CI (- 9)-11] and heart failure [- 2%; CI (- 10)-6] were less affected and remained comparable to the previous year. CONCLUSIONS: ED visits were noticeably reduced during both SARS-CoV-2 pandemic waves in Germany but cardiovascular diagnoses were less affected and no refractory increase was noted. However, long-term effects cannot be ruled out and need to be analysed in future studies.

[COVID-19 in GP Practice and Emergency Rooms - Update 2021]. / Update 2021: COVID-19 aus Sicht der Praxen und Notaufnahmen.

COVID-19 continues to pose major challenges for GP practice and emergency rooms across Germany. Even if there is now a certain routine, the optimal treatment of patients is still difficult. This article provides an overview of the aspects of caring for COVID-19 patients in GP practice and emergency rooms and the changes since the beginning of the pandemic.

[COVID-19 in GP Practice and Emergency Rooms]. / COVID-19 aus Sicht der Praxen und Notaufnahmen.

COVID-19 challenges GP practice and emergency rooms across Germany. In addition to hygiene, the correct assignment of patients to outpatient, inpatient or intensive care management is difficult. This article provides an overview of aspects of initial care, management and risk assessment in COVID-19 patients. The care of corona infected patients can be improved at the interface between outpatient and inpatient care. There can be no "business as usual" after the crisis! Age, male sex and overweight are among the most important risk factors for serious corona disease. Poor oxygen saturation (< 88 %) and increased signs of inflammation (CRP > 97 mg/l and/or IL-6 > 80 pg/ml) indicate a critical course and should be determined in symptomatic patients. Only through regular dialogue between hospital and practice can meaningful decisions be made to slowly move from individual cases to a basic care structure.

[Prevention of "contrast-induced" acute kidney injury - practical considerations]. / Prävention der "Kontrastmittel-induzierten" Nephropathie ­ was ist zu beachten?

Acute kidney injury (AKI) episodes after iodine radiocontrast application are decreasing since non-ionic agents are routinely used. Retrospective studies (in total comprising more than 100 000 patients) DO NOT show increased AKI rates after CT scans with the application of radiocontrast (vs. uncontrasted CT scans). AKI rates are generally higher after intra-arterial (i. a.) compared with intra-venous (i. v.) radiocontrast application - cholesterol embolism due to catheter manipulation does play a role in this setting. Because of the multifactorial pathogenesis the term "contrast-associated AKI" (CA-AKI) should be used preferentially. The AMACING trial, which prospectively evaluated the use of i. v. volume administration before contrast application to prevent CA-AKI, DID NOT show a benefit for volume therapy. Instead, the trial found a significant increase in symptomatic heart failure episodes in patients after volume administrastion. "Hydration" before (emergency) contrasted CT scans therefore can put patients at risk through both volume overload and diagnostic delay. The PRESERVE trial prospectively evaluated the use of volume administration and N-acetyl cysteine (NAC) before i. a. contrast application to prevent CA-AKI. While NAC, which was placebo controlled, did not show any benefit (and therefore should not be used anymore), all patients in the PRESERVE trial received i. v. volume (either sodium chloride or sodium bicarbonate). Interestingly, the incidence of CA-AKI in both groups was below 5 % and hence almost half of what was expected based on previous trials. If the baseline volume status is checked in order to avoid overload, volume administration in patients with i. a. contrast application can be safely performed until definitive data are available. The type of solution can be pragmatically guided by the patient's acid base status. While preventive measures to avoid CA-AKI are limited, the clinical relevance of (any) AKI remains - new data showing increased morbidity and mortality with creatinine increments of onl 0.3 mg/dl. In order to distinguish CA-AKI from other, potentially treatably forms of AKI (e. g. pre- or post-renal AKI), early consultation of a nephrologist seems favorable.

Double-stranded DNA induces a prothrombotic phenotype in the vascular endothelium.

Double-stranded DNA (dsDNA) constitutes a potent activator of innate immunity, given its ability to bind intracellular pattern recognition receptors during viral infections or sterile tissue damage. While effects of dsDNA in immune cells have been extensively studied, dsDNA signalling and its pathophysiological implications in non-immune cells, such as the vascular endothelium, remain poorly understood. The aim of this study was to characterize prothrombotic effects of dsDNA in vascular endothelial cells. Transfection of cultured human endothelial cells with the synthetic dsDNA poly(dA:dT) induced upregulation of the prothrombotic molecules tissue factor and PAI-1, resulting in accelerated blood clotting in vitro, which was partly dependent on RIG-I signalling. Prothrombotic effects were also observed upon transfection of endothelial cells with hepatitis B virus DNA-containing immunoprecipitates as well human genomic DNA. In addition, dsDNA led to surface expression of von Willebrand factor resulting in increased platelet-endothelium-interactions under flow. Eventually, intrascrotal injection of dsDNA resulted in accelerated thrombus formation upon light/dye-induced endothelial injury in mouse cremaster arterioles and venules in vivo. In conclusion, we show that viral or endogenous dsDNA induces a prothrombotic phenotype in the vascular endothelium. These findings represent a novel link between pathogen- and danger-associated patterns within innate immunity and thrombosis.

Arterial thrombosis in the context of HCV-associated vascular disease can be prevented by protein C.

Hepatitis C virus (HCV) infection is a major problem worldwide. HCV is not limited to liver disease but is frequently complicated by immune-mediated extrahepatic manifestations such as glomerulonephritis or vasculitis. A fatal complication of HCV-associated vascular disease is thrombosis. Polyriboinosinic:polyribocytidylic acid (poly (I:C)), a synthetic analog of viral RNA, induces a Toll-like receptor 3 (TLR3)-dependent arteriolar thrombosis without significant thrombus formation in venules in vivo. These procoagulant effects are caused by increased endothelial synthesis of tissue factor and PAI-1 without platelet activation. In addition to human umbilical endothelial cells (HUVEC), human mesangial cells (HMC) produce procoagulatory factors, cytokines and adhesion molecules after stimulation with poly (I:C) or HCV-containing cryoprecipitates from a patient with a HCV infection as well. Activated protein C (APC) is able to prevent the induction of procoagulatory factors in HUVEC and HMC in vitro and blocks the effects of poly (I:C) and HCV-RNA on the expression of cytokines and adhesion molecules in HMC but not in HUVEC. In vivo, protein C inhibits poly (I:C)-induced arteriolar thrombosis. Thus, endothelial cells are de facto able to actively participate in immune-mediated vascular thrombosis caused by viral infections. Finally, we provide evidence for the ability of protein C to inhibit TLR3-mediated arteriolar thrombosis caused by HCV infection.

BK virus infection activates the TNFα/TNF receptor system in Polyomavirus-associated nephropathy.

Polyomavirus-associated nephropathy due to BK virus infection (BKVAN) is recognized as an important cause of significant kidney transplant dysfunction often leading to renal graft loss. The activation of innate immune defense mechanisms during BKVAN is still poorly understood and an altered regulation of inflammatory mediators by resident kidney cells upon viral infection can be expected to contribute to the onset and progression of disease. TNFα interacting with its receptors, TNF receptor 1 (TNFR1) and TNF receptor 2 (TNFR2), is largely accepted to be involved in viral responses, exhibiting both proinflammatory and immunosuppressive effects. Our aim was to examine the expressions of TNFα and TNFR1 and 2 in human collecting duct epithelial cells (HCDC) after infection with BKV as well as to study the effect of TNFα and poly(I:C), a synthetic analog of viral RNA, on the expressions of TNF receptors and proinflammatory cytokines and chemokines in HCDC. Quantitative RT-PCR analyses showed a downregulation of TNFα and an upregulation of both TNFR1 and 2 upon exposure of HCDC to the BK virus. TNFα stimulation induced the expressions of IL-6, IL-8, RANTES, and TNFR2. Poly(I:C) upregulated the expressions of both TNFR1 and TNFR2, a response that could be effectively blocked by siRNA to TLR3 and RIG-I, two double-stranded (ds) RNA receptors of the innate immune system. Poly(I:C)-dependent expression of TNFR2 but not TNFR1 was enhanced by TNFα. Taken together, our results suggest an involvement of TNF/TNFR system in virus-associated nephropathy.

LL37 inhibits the inflammatory endothelial response induced by viral or endogenous DNA.

In viral infection, morbidity and mortality often result from extrahepatic disease manifestations such as vasculitis. We hereby show that human microvascular endothelial cells express viral receptors of the innate immune system which are induced upon ligand engagement. Furthermore, stimulation of endothelial cells with the synthetic analog of viral DNA, poly (dA:dT), human DNA and hepatitis B virus-containing immunoprecipitates from a patient with polyarteritis nodosa induces an inflammatory response including the upregulation of adhesion molecules, which is mediated exclusively by TLR9 and involves an IRF3-dependent pathway. Thus, endothelial cells are able to actively participate in immune mediated vascular inflammation caused by viral infections. Furthermore, we provide evidence for the ability of LL37 to bind and internalize viral or endogenous DNA into non-immune cells. DNA nucleotides internalized by LL37 suppress the production of proinflammatory mediators suggesting a protective effect against direct responses to viral infection or circulating DNA-fragments of endogenous origin.

The tyrosine phosphatase SHP-1 regulates hypoxia inducible factor-1α (HIF-1α) protein levels in endothelial cells under hypoxia.

INTRODUCTION: The tyrosine phosphatase SHP-1 negatively influences endothelial function, such as VEGF signaling and reactive oxygen species (ROS) formation, and has been shown to influence angiogenesis during tissue ischemia. In ischemic tissues, hypoxia induced angiogenesis is crucial for restoring oxygen supply. However, the exact mechanism how SHP-1 affects endothelial function during ischemia or hypoxia remains unclear. We performed in vitro endothelial cell culture experiments to characterize the role of SHP-1 during hypoxia. RESULTS: SHP-1 knock-down by specific antisense oligodesoxynucleotides (AS-Odn) increased cell growth as well as VEGF synthesis and secretion during 24 hours of hypoxia compared to control AS-Odn. This was prevented by HIF-1α inhibition (echinomycin and apigenin). SHP-1 knock-down as well as overexpression of a catalytically inactive SHP-1 (SHP-1 CS) further enhanced HIF-1α protein levels, whereas overexpression of a constitutively active SHP-1 (SHP-1 E74A) resulted in decreased HIF-1α levels during hypoxia, compared to wildtype SHP-1. Proteasome inhibition (MG132) returned HIF-1α levels to control or wildtype levels respectively in these cells. SHP-1 silencing did not alter HIF-1α mRNA levels. Finally, under hypoxic conditions SHP-1 knock-down enhanced intracellular endothelial reactive oxygen species (ROS) formation, as measured by oxidation of H2-DCF and DHE fluorescence. CONCLUSIONS: SHP-1 decreases half-life of HIF-1α under hypoxic conditions resulting in decreased cell growth due to diminished VEGF synthesis and secretion. The regulatory effect of SHP-1 on HIF-1α stability may be mediated by inhibition of endothelial ROS formation stabilizing HIF-1α protein. These findings highlight the importance of SHP-1 in hypoxic signaling and its potential as therapeutic target in ischemic diseases.

Hepatitis C virus induced endothelial inflammatory response depends on the functional expression of TNFα receptor subtype 2.

In hepatitis C virus (HCV) infection, morbidity and mortality often result from extrahepatic disease manifestations. We provide evidence for a role of receptors of the innate immune system in virally induced inflammation of the endothelium in vitro and in vivo. Corresponding to the in vitro finding of an HCV-dependent induction of proinflammatory mediators in endothelial cells, mice treated with poly (I:C) exhibit a significant reduction in leukocyte rolling velocity, an increase in leukocyte adhesion to the vessel wall and an increased extravasation of leukocytes. HCV directly promotes activation, adhesion and infiltration of inflammatory cells into the vessel wall by activation of endothelial viral receptors. Poly (I:C) induces the expression of TLR3 in vivo and hereby allows for amplification of all of the aforementioned responses upon viral infection. Proinflammatory effects of viral RNA are specifically mediated by TLR3 and significantly enhanced by tumor necrosis factor alpha (TNFα). HCV-RNA induces the endothelial expression of TNFα and TNFα receptor subtype 2 and we provide evidence that leucocyte adhesion and transmigration in response to activation of viral RNA receptors seem to depend on expression of functional TNFR2. Our results demonstrate that endothelial cells actively participate in immune mediated vascular inflammation caused by viral infections.

Viral nucleic acid recognition in human nonimmune cells: in vitro systems.

The innate immune system detects viral infections through a variety of receptors that sense the virus via their nucleic acid genome and evokes initial antiviral responses. Nonimmune cells possess pathogen-recognition mechanisms that enable them to respond to virus by the expression of RNA or DNA recognition receptors, thereby initiating the first steps in the host-pathogen interaction and inducing the production of pro-inflammatory and antiviral mediators. To better understand the activation of innate-immune defense mechanisms by nonimmune cells, we describe an experimental procedure that mimics viral infection, using four human nonimmune cell culture models under stimulation with synthetic analogues of RNA and DNA virus. Furthermore, we exemplify two viral infection models using cultured nonimmune cells and hepatitis C virus (HCV) or polyomavirus BK (BKV). In addition, we report the importance of siRNA technique in gene regulation in order to identify specific markers involved in innate antiviral responses in these cells.

Renal lipidosis in patients enrolled in a methadone substitution program.

Kidney biopsies often show accumulation of lipids or lipidlike material. Evidence has been provided that lipids can directly initiate and contribute to the progression of glomerular and tubulointerstitial lesions. In this study we describe a renal lipidosis occurring in patients with a positive history of narcotic abuse who were enrolled in a methadone substitution program. All 3 patients presented with proteinuria (2.5-20 g/d) and impaired renal function. Renal biopsy revealed a pronounced extracellular and intracellular deposition of lipidlike material in the glomerular, interstitial, and tubular compartments. Known causes of lipid storage could be excluded clinically and morphologically. We consider this to be a distinct renal lipidosis associated with narcotic abuse, methadone intake, or intravenous abuse thereof.

The endothelial tyrosine phosphatase SHP-1 plays an important role for vascular haemostasis in TNFα -induced inflammation in vivo.

INTRODUCTION: Inflammation and endothelium-derived superoxides are important pathomechanisms in atherothrombotic diseases. We could previously show that the tyrosine phosphatase SHP-1 acts as a negative regulator in endothelial superoxide production. In this study we investigated the influence of SHP-1 on platelet-endothelium interaction and arterial thrombosis in TNFα -induced endothelial inflammation in vivo. METHODS: Arteriolar thrombosis and platelet rolling in vivo were investigated in C57BL/6 mice using intravital microscopy in the dorsal skinfold chamber microcirculation model. RESULTS: Inhibition of SHP-1 by the specific pharmacological inhibitor sodium stibogluconate did not significantly enhance platelet-endothelium interaction in vivo under physiological conditions but led to an augmented fraction of rolling platelets in TNFα -induced systemic inflammation. Accordingly, ferric-chloride-induced arteriolar thrombus formation, which was already increased by SHP-1 inhibition, was further enhanced in the setting of TNFα -induced inflammation. Platelet aggregation in vitro as well as ex vivo was not influenced by SHP-1-inhibition. In cultured endothelial cells, sodium stibogluconate increased TNFα -induced surface expression of p-selectin and von Willebrand factor. Additionally, TNFα increased SHP-1 activity and protein expression. CONCLUSIONS: The endothelial tyrosine phosphatase SHP-1 plays an important role for vascular hemostasis in vivo, which is crucial in TNF α -induced endothelial inflammation where it may serve as an autoinhibitory molecule to prevent excess inflammatory response and thrombus formation.

PAR-1 mediates the thrombin-induced mesothelial cell overproduction of VEGF and PAI-1.

PURPOSE: Thrombin mediates an excess in the production of neoangiogenetic (VEGF) and profibrotic (PAI-1) factors in human peritoneal mesothelial cells (HMC). The mechanisms leading to this overproduction have not been elucidated so far; in the context of peritoneal dialysis it can result in impaired peritoneal membrane function. OBJECTIVES: This study was performed to evaluate the presence of the thrombin receptor protease-activated receptor-1 (PAR-1) in HMC and to characterize its function in the thrombin-dependent effects mentioned above. METHODS: All experiments were performed using cultured primary HMC. Real-Time PCR and Western Blot were used to evaluate PAR-1; ELISA and Real-Time PCR were employed to examine PAR-1 effects on target mediators. RESULTS: We found that cultivated primary HMC show a basal presence of PAR-1. Stimulation with IL-1ß induced an increase of the mesothelial PAR-1 expression whereas stimulation with glycosilated human serum albumin or the ligand thrombin itself resulted in decreased PAR-1 expression. Stimulation with the specific PAR-1 ligand TFLLR-NH(2) caused increased VEGF and PAI-1 levels similar to stimulation with thrombin, whereas preincubation with PAR-1 blocking antibodies ATAP2 and WEDE15 attenuated the thrombin-induced overproduction of VEGF and PAI-1. CONCLUSIONS: HMC express PAR-1 and the receptor is involved in thrombin effects on these cells. These findings may be a basis for pharmacological prevention of neoangiogenesis and adhesions in the context of peritoneal dialysis and peritonitis.

Prothrombotic effects of tumor necrosis factor alpha in vivo are amplified by the absence of TNF-alpha receptor subtype 1 and require TNF-alpha receptor subtype 2.

INTRODUCTION: Elevated serum levels of the proinflammatory cytokine tumor necrosis factor alpha (TNFα) correlate with an increased risk for atherothrombotic events and TNFα is known to induce prothrombotic molecules in endothelial cells. Based on the preexisting evidence for the impact of TNFα in the pathogenesis of autoimmune disorders and their known association with an acquired hypercoagulability, we investigated the effects of TNFα and the role of the TNF receptor subtypes TNFR1 and TNFR2 for arteriolar thrombosis in vivo. METHODS: Arteriolar thrombosis and platelet-rolling in vivo were investigated in wildtype, TNFR1-/-, TNFR2-/- and TNFR1-/R2-/- C57BL/6 mice using intravital microscopy in the dorsal skinfold chamber microcirculation model. In vitro, expression of prothrombotic molecules was assessed in human endothelial cells by real-time PCR and flow cytometry. RESULTS: In wildtype mice, stimulation with TNFα significantly accelerated thrombotic vessel occlusion in vivo upon ferric chloride injury. Arteriolar thrombosis was much more pronounced in TNFR1-/- animals, where TNFα additionally led to increased platelet-endothelium-interaction. TNFα dependent prothrombotic effects were not observed in TNFR2-/- and TNFR1-/R2- mice. In vitro, stimulation of human platelet rich plasma with TNFα did not influence aggregation properties. In human endothelial cells, TNFα induced superoxide production, p-selectin, tissue factor and PAI-1, and suppressed thrombomodulin, resulting in an accelerated endothelial dependent blood clotting in vitro. Additionally, TNFα caused the release of soluble mediators by endothelial cells which induced prothrombotic and suppressed anticoagulant genes comparable to direct TNFα effects. CONCLUSIONS: TNFα accelerates thrombus formation in an in vivo model of arteriolar thrombosis. Its prothrombotic effects in vivo require TNFR2 and are partly compensated by TNFR1. In vitro studies indicate endothelial mechanisms to be responsible for prothrombotic TNFα effects. Our results support a more selective therapeutic approach in anticytokine therapy favouring TNFR2 specific antagonists.