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1.
Langmuir ; 40(27): 13810-13818, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38918081

ABSTRACT

The friction of solids is primarily understood through the adhesive interactions between the surfaces. As a result, slick materials tend to be nonstick (e.g., Teflon), and sticky materials tend to produce high friction (e.g., tires and tape). Paradoxically, cartilage, the slippery bearing material of human joints, is also among the stickiest of known materials. This study aims to elucidate this apparent paradox. Cartilage is a biphasic material, and the most cited explanation is that both friction and adhesion increase as load transfers from the pressurized interstitial fluid to the solid matrix over time. In other words, cartilage is slippery and sticky under different times and conditions. This study challenges this explanation, demonstrating the strong adhesion of cartilage under high and low interstitial hydration conditions. Additionally, we find that cartilage clings to itself (a porous material) and Teflon (a nonstick material), as well as other surfaces. We conclude that the unusually strong interfacial tension produced by cartilage reflects suction (like a clingfish) rather than adhesion (like a gecko). This finding is surprising given its unusually large roughness, which typically allows for easy interfacial flow and defeats suction. The results provide compelling evidence that cartilage, like a clingfish, conforms to opposing surfaces and effectively seals submerged contacts. Further, we argue that interfacial sealing is itself a critical function, enabling cartilage to retain hydration, load support, and lubrication across long periods of inactivity.


Subject(s)
Cartilage, Articular , Cartilage, Articular/chemistry , Animals , Friction , Lubrication , Surface Properties , Adhesiveness , Polytetrafluoroethylene/chemistry
2.
Curr Opin Microbiol ; 79: 102467, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38569418

ABSTRACT

Bacterial cells have a unique challenge to organize their cytoplasm without the use of membrane-bound organelles. Biomolecular condensates (henceforth BMCs) are a class of nonmembrane-bound organelles, which, through the physical process of phase separation, can form liquid-like droplets with proteins/nucleic acids. BMCs have been broadly characterized in eukaryotic cells, and BMCs have been recently identified in bacteria, with the first and best studied example being bacterial ribonucleoprotein bodies (BR-bodies). BR-bodies contain the RNA decay machinery and show functional parallels to eukaryotic P-bodies (PBs) and stress granules (SGs). Due to the finding that mRNA decay machinery is compartmentalized in BR-bodies and in eukaryotic PBs/SGs, we will explore the functional similarities in the proteins, which are known to enrich in these structures based on recent proteomic studies. Interestingly, despite the use of different mRNA decay and post-transcriptional regulatory machinery, this analysis has revealed evolutionary convergence in the classes of enriched enzymes in these structures.


Subject(s)
Bacteria , RNA Stability , Bacteria/genetics , Bacteria/metabolism , Eukaryotic Cells/metabolism , Proteomics , Biomolecular Condensates/metabolism , Biomolecular Condensates/chemistry , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , RNA, Bacterial/metabolism , RNA, Bacterial/genetics , Evolution, Molecular
3.
bioRxiv ; 2023 Jul 13.
Article in English | MEDLINE | ID: mdl-36712072

ABSTRACT

Bacterial RNP bodies (BR-bodies) are non-membrane-bound structures that facilitate mRNA decay by concentrating mRNA substrates with RNase E and the associated RNA degradosome machinery. However, the full complement of proteins enriched in BR-bodies has not been defined. Here we define the protein components of BR-bodies through enrichment of the bodies followed by mass spectrometry-based proteomic analysis. We found 111 BR-body enriched proteins, including several RNA binding proteins, many of which are also recruited directly to in vitro reconstituted RNase E droplets, showing BR-bodies are more complex than previously assumed. While most BR-body enriched proteins that were tested cannot phase separate, we identified five that undergo RNA-dependent phase separation in vitro, showing other RNP condensates interface with BR-bodies. RNA degradosome protein clients are recruited more strongly to RNase E droplets than droplets of other RNP condensates, implying that client specificity is largely achieved through direct protein-protein interactions. We observe that some RNP condensates assemble with preferred directionally, suggesting that RNA may be trafficked through RNP condensates in an ordered manner to facilitate mRNA processing/decay, and that some BR-body associated proteins have the capacity to dissolve the condensate. Finally, we find that RNA dramatically stimulates the rate of RNase E phase separation in vitro, explaining the dissolution of BR-bodies after cellular mRNA depletion observed previously. Altogether, these results suggest that a complex network of protein-protein and protein-RNA interactions controls BR-body phase separation and RNA processing.

4.
Basic Res Cardiol ; 117(1): 21, 2022 04 07.
Article in English | MEDLINE | ID: mdl-35389088

ABSTRACT

Inflammatory cell infiltration is central to healing after acute myocardial infarction (AMI). The relation of regional inflammation to edema, infarct size (IS), microvascular obstruction (MVO), intramyocardial hemorrhage (IMH), and regional and global LV function is not clear. Here we noninvasively characterized regional inflammation and contractile function in reperfused AMI in pigs using fluorine (19F) cardiovascular magnetic resonance (CMR). Adult anesthetized pigs underwent left anterior descending coronary artery instrumentation with either 90 min occlusion (n = 17) or without occlusion (sham, n = 5). After 3 days, in surviving animals a perfluorooctyl bromide nanoemulsion was infused intravenously to label monocytes/macrophages. At day 6, in vivo 1H-CMR was performed with cine, T2 and T2* weighted imaging, T2 and T1 mapping, perfusion and late gadolinium enhancement followed by 19F-CMR. Pigs were sacrificed for subsequent ex vivo scans and histology. Edema extent was 35 ± 8% and IS was 22 ± 6% of LV mass. Six of ten surviving AMI animals displayed both MVO and IMH (3.3 ± 1.6% and 1.9 ± 0.8% of LV mass). The 19F signal, reflecting the presence and density of monocytes/macrophages, was consistently smaller than edema volume or IS and not apparent in remote areas. The 19F signal-to-noise ratio (SNR) > 8 in the infarct border zone was associated with impaired remote systolic wall thickening. A whole heart value of 19F integral (19F SNR × milliliter) > 200 was related to initial LV remodeling independently of edema, IS, MVO, and IMH. Thus, 19F-CMR quantitatively characterizes regional inflammation after AMI and its relation to edema, IS, MVO, IMH and regional and global LV function and remodeling.


Subject(s)
Contrast Media , Myocardial Infarction , Animals , Gadolinium , Hemorrhage/pathology , Inflammation , Magnetic Resonance Imaging , Magnetic Resonance Spectroscopy , Myocardial Infarction/pathology , Swine
5.
Internist (Berl) ; 61(9): 980-988, 2020 Sep.
Article in German | MEDLINE | ID: mdl-32572515

ABSTRACT

The Spanish Hygia study has led to considerable irritation due to the general recommendation to prescribe antihypertensives preferably to be taken in the evening, especially since the lay press as well as medical media made enthusiastic comments. The discussion about the optimal time to take antihypertensive drugs shows once again how dangerous the uncritical handling of study data can be. No possible risks were pointed out. The Hygia study compared 19,084 patients with morning and evening intake of antihypertensive drugs under the control of a 48­h blood pressure measurement (!). There was a significantly better reduction in blood pressure and the rate of cardiovascular and cerebrovascular events with evening intake. The data are scientifically valuable; however, the conclusions are incomprehensible based on the data, contradict many other studies and are dangerous for certain patient groups. There are also methodological shortcomings. Therefore, a general evening intake is not justified and nonsensical due to the diverse, individually very different pathophysiological findings of the nocturnal blood pressure behavior. Basically, the outpatient 24­h blood pressure measurement (ABPM) enables a better assessment of the individual cardiovascular and cerebrovascular risks and prevents an incorrect assessment of the blood pressure and thus unnecessary or sufficient treatment. Instead of a general recommendation, the ABPM offers the option of an individually tailored treatment. Taking antihypertensive drugs in the evening should always be preceded by an ABDM in the case of prognostically unfavorable nocturnal hypertension in order to avoid the risk of nocturnal ischemic risks due to excessive drops in blood pressure.


Subject(s)
Antihypertensive Agents/therapeutic use , Hypertension/drug therapy , Blood Pressure , Blood Pressure Determination , Blood Pressure Monitoring, Ambulatory , Humans , Time Factors , Treatment Outcome
6.
J Dent Res ; 97(8): 946-953, 2018 07.
Article in English | MEDLINE | ID: mdl-29514008

ABSTRACT

Tristetraprolin (TTP) is an RNA-binding protein that targets numerous immunomodulatory mRNA transcripts for degradation. Many TTP targets are key players in the pathogenesis of periodontal bone loss, including tumor necrosis factor-α. To better understand the extent that host immune factors play during periodontal bone loss, we assessed alveolar bone levels, inflammation and osteoclast activity in periodontal tissues, and immune response in draining cervical lymph nodes in TTP-deficient and wild-type (WT) mice in an aging study. WT and TTP-deficient (knockout [KO]) mice were used for all studies under specific pathogen-free conditions. Data were collected on mice aged 3, 6, and 9 mo. Microcomputed tomography (µCT) was performed on maxillae where 3-dimensional images were generated and bone loss was assessed. Decalcified sections of specimens were scored for inflammation and stained with tartrate-resistant acid phosphate (TRAP) to visualize osteoclasts. Immunophenotyping was performed on single-cell suspensions isolated from primary and peripheral lymphoid tissues using flow cytometry. Results presented indicate that TTP KO mice had significantly more alveolar bone loss over time compared with WT controls. Bone loss was associated with significant increases in inflammatory cell infiltration and an increased percentage of alveolar bone surfaces apposed with TRAP+ cells. Furthermore, it was found that the draining cervical lymph nodes were significantly enlarged in TTP-deficient animals and contained a distinct pathological immune profile compared with WT controls. Finally, the oral microbiome in the TTP KO mice was significantly different with age from WT cohoused mice. The severe bone loss, inflammation, and increased osteoclast activity observed in these mice support the concept that TTP plays a critical role in the maintenance of alveolar bone homeostasis in the presence of oral commensal flora. This study suggests that TTP is required to inhibit excessive inflammatory host responses that contribute to periodontal bone loss, even in the absence of specific periodontal pathogens.


Subject(s)
Alveolar Bone Loss/diagnostic imaging , Alveolar Bone Loss/immunology , Tristetraprolin/immunology , Animals , Biomarkers/blood , Disease Models, Animal , Female , Flow Cytometry , Homeostasis/immunology , Imaging, Three-Dimensional , Male , Mice , Mice, Knockout , Osteoclasts/metabolism , Phenotype , Specific Pathogen-Free Organisms , Tristetraprolin/deficiency , X-Ray Microtomography
7.
Herz ; 43(3): 197-206, 2018 May.
Article in German | MEDLINE | ID: mdl-29188356

ABSTRACT

Arterial hypertension is the most common modifiable risk factor for cerebrovascular and cardiovascular morbidity and mortality in old age. The prevention of cognitive brain disorders is also a therapeutic goal of long-term treatment of hypertension. Older patients also have a higher risk of developing cardiovascular diseases and therefore benefit from a relatively moderate reduction in blood pressure. With respect to the high prevalence of hypertension in old age and the increasing incidence with time, the therapy of hypertension is becoming increasingly more important to achieve an improved prognosis for patients along with a reduction of costs. The accurate blood pressure measurement for elderly patients includes repeated measurements while standing and sitting. Additionally, the measurements should also be conducted by the patient or by a family member. The most accurate method for assessing the daily blood pressure level, e.g. practice hypertension, non-dipping and intermittent hypertension, is the 24-h blood pressure measurement by ambulatory blood pressure monitoring (ABPM). General measures and lifestyle interventions are effective for reducing blood pressure of elderly patients with hypertension and a low salt diet is scientifically proven to be superior. The same drugs used for young people are also recommended for older patients and most give preference to diuretics, renin-angiotensin-aldosterone system (RAAS) inhibitors and calcium antagonists. The target blood pressure in elderly patients is repeatedly the focus of scientific discussions. The current recommendations are presented in the text and the characteristics which must be particularly considered in the therapy of elderly patients are presented in detail.


Subject(s)
Antihypertensive Agents , Blood Pressure Monitoring, Ambulatory , Hypertension , Aged , Antihypertensive Agents/therapeutic use , Blood Pressure , Blood Pressure Determination , Humans , Hypertension/drug therapy
8.
J Dermatol Sci ; 87(3): 292-299, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28743609

ABSTRACT

BACKGROUND: Application of haptens to the skin induces release of immune stimulatory ATP into the extracellular space. This "danger" signal can be converted to immunosuppressive adenosine (ADO) by the action of the ectonucleotidases CD39 and CD73, expressed by skin and immune cells. Thus, the expression and regulation of CD73 by skin derived cells may have crucial influence on the outcome of contact hypersensitivity (CHS) reactions. OBJECTIVE: To investigate the role of CD73 expression during 2,4,6-trinitrochlorobenzene (TNCB) induced CHS reactions. METHODS: Wild type (wt) and CD73 deficient mice were subjected to TNCB induced CHS. In the different mouse strains the resulting ear swelling reaction was recorded along with a detailed phenotypic analysis of the skin migrating subsets of dendritic cells (DC). RESULTS: In CD73 deficient animals the motility of DC was higher as compared to wt animals and in particular after sensitization we found increased migration of Langerin+ DC from skin to draining lymph nodes (LN). In the TNCB model this led to a stronger sensitization as indicated by increased frequency of interferon-γ producing T cells in the LN and an increased ear thickness after challenge. CONCLUSION: CD73 derived ADO production slows down migration of Langerin+ DC from skin to LN. This may be a crucial mechanism to avoid over boarding immune reactions against haptens.


Subject(s)
5'-Nucleotidase/metabolism , Cell Movement/immunology , Dendritic Cells/immunology , Dermatitis, Allergic Contact/immunology , Skin/cytology , 5'-Nucleotidase/genetics , 5'-Nucleotidase/immunology , Adenosine/immunology , Adenosine/metabolism , Adenosine Triphosphate/immunology , Adenosine Triphosphate/metabolism , Animals , Antigens, Surface/metabolism , Cells, Cultured , Dendritic Cells/metabolism , Disease Models, Animal , GPI-Linked Proteins/genetics , GPI-Linked Proteins/immunology , GPI-Linked Proteins/metabolism , Haptens/administration & dosage , Haptens/immunology , Interferon-gamma/metabolism , Lectins, C-Type/metabolism , Lymph Nodes/cytology , Lymph Nodes/immunology , Mannose-Binding Lectins/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Picryl Chloride/administration & dosage , Picryl Chloride/immunology , Skin/immunology , Skin/metabolism , T-Lymphocytes/immunology , T-Lymphocytes/metabolism
10.
Eur J Surg Oncol ; 43(4): 758-762, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28131667

ABSTRACT

BACKROUND: The risk assessment of intraductal papillary mucinous neoplasms (IPMN) to either guide patients to surgical resection or watchful waiting is still under debate. Additional markers to better separate low and high-risk lesions would improve patient selection. METHODS: Patients who underwent pancreatic resections for IPMNs between January 2008 and December 2012 with available blood samples were selected and retrospectively assessed. Data on cyst characteristics such as cyst size, duct relation and main-duct dilatation were collected and plasma fibrinogen levels were measured. RESULTS: A total of 73 patients fulfilled the inclusion criteria by pancreatic resection for pathologically confirmed IPMN and available blood sample. Histologically, IPMNs were classified as low-grade and borderline in 52 (71.2%, group 1) and as high-grade and invasive in 21 (28.8%, group 2) of all cases. Fibrinogen levels showed significant differences between the two groups (group 1: mean 3.62 g/L (SD ± 1.14); group 2: mean 4.49 g/L (SD ± 1.57); p = 0.027). A ROC-curve analysis calculated cut-off value of 4.71 g/L separated groups 1 and 2 (p = 0.008). Fibrinogen levels remained as the only significant factor in multivariable analysis, cyst size and duct relation were not significant. CONCLUSION: Blood fibrinogen differed between low and high risk IPMNs and therefore, the use of fibrinogen as an additional discriminator in the pre-operative risk assessment of IPMNs should be further evaluated.


Subject(s)
Adenocarcinoma, Mucinous/blood , Carcinoma, Pancreatic Ductal/blood , Carcinoma, Papillary/blood , Fibrinogen/metabolism , Pancreatic Neoplasms/blood , Adenocarcinoma, Mucinous/pathology , Adenocarcinoma, Mucinous/surgery , Adult , Aged , Aged, 80 and over , Carcinoma, Pancreatic Ductal/pathology , Carcinoma, Pancreatic Ductal/surgery , Carcinoma, Papillary/pathology , Carcinoma, Papillary/surgery , Female , Humans , Male , Middle Aged , Multivariate Analysis , Neoplasm Grading , Neoplasm Invasiveness , Pancreatectomy , Pancreatic Neoplasms/pathology , Pancreatic Neoplasms/surgery , ROC Curve , Retrospective Studies
11.
J Periodontal Res ; 52(3): 377-387, 2017 Jun.
Article in English | MEDLINE | ID: mdl-27509894

ABSTRACT

BACKGROUND AND OBJECTIVE: Periodontal disease pathogenesis is comprised of the complex inflammatory immune response to oral bacterial dysbiosis. Like other inflammatory diseases, there is sexual dimorphism evident in periodontal diseases. During periodontitis, inflammatory chemokines direct neutrophils to migrate to the site of infection to neutralize the pathogen. Interestingly, these same chemokines are also involved in regulating pathogen-induced osteoclast formation. Previous reports show differences in bone turnover and lymphocyte recruitment between sexes. We hypothesize that chemokine expression is differentially regulated by sex and thus results in differential osteoclast formation. MATERIAL AND METHODS: Male and female mice were utilized to isolate neutrophils based on expression of Ly6G-specific, as well as defined osteoclast progenitors. Cells were stimulated with lipopolysaccharide (LPS; 100 ng/mL) then analyzed for neutrophil infiltration and gene expression. Defined osteoclast progenitors were primed: macrophage-colony stimulating factor (25 ng/mL), receptor activator of NF-κB ligand (50 ng/mL), then stimulated with LPS. Osteoclasts were enumerated via TRAP stain and mRNA isolated for gene expression analysis via quantitative polymerase chain reaction. RESULTS: In response to LPS, male neutrophils in vitro respond with increased chemokine expression and significantly more osteoclast formed in response to LPS compared to females. CONCLUSIONS: Findings support observations in humans regarding a sexual dimorphism in oral bacterial infections of alveolar bone loss. Males have a strong inflammatory response to bacterial infection, resulting in increased inflammatory microenvironment, reduced pathogenic bacteria clearance and increased osteoclast-driven bone loss in response to differential expression of key chemokines.


Subject(s)
Bone Resorption/microbiology , Animals , Bone Resorption/physiopathology , Chemokines/metabolism , Female , Lipopolysaccharides/pharmacology , Male , Mice , Neutrophils/physiology , Osteoclasts/metabolism , Polymerase Chain Reaction , Sex Factors
12.
J Neuroinflammation ; 13: 48, 2016 Feb 26.
Article in English | MEDLINE | ID: mdl-26920550

ABSTRACT

BACKGROUND: Conditions of inflammatory tissue distress are associated with high extracellular levels of adenosine, due to increased adenosine triphosphate (ATP) degradation upon cellular stress or the release of extracellular ATP upon cell death, which can be degraded to adenosine by membrane-bound ecto-enzymes like CD39 and CD73. Adenosine is recognised to mediate anti-inflammatory effects via the adenosine A2a receptor (A2aR), as shown in experimental models of arthritis. Here, using pharmacological interventions and genetic inactivation, we investigated the roles of A2aR in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). METHODS: We used two independent mouse EAE variants, i.e. active immunization in C57BL/6 with myelin oligodendrocyte glycoprotein (MOG)35-55 or transfer-EAE by proteolipid protein (PLP)139-155-stimulated T lymphocytes and EAE in mice treated with A2aR-agonist CGS21680 at different stages of disease course and in mice lacking A2aR (A2aR(-/-)) compared to direct wild-type littermates. In EAE, we analysed myelin-specific proliferation and cytokine synthesis ex vivo, as well as inflammation and demyelination by immunohistochemistry. In vitro, we investigated the effect of A2aR on migration of CD4(+) T cells, macrophages and microglia, as well as the impact of A2aR on phagocytosis of macrophages and microglia. Statistical tests were Mann-Whitney U and Student's t test. RESULTS: We found an upregulation of A2aR in the central nervous system (CNS) in EAE, predominantly detected on T cells and macrophages/microglia within the inflamed tissue. Preventive EAE treatment with A2aR-specific agonist inhibited myelin-specific T cell proliferation ex vivo and ameliorated disease, while application of the same agonist after disease onset exacerbated non-remitting EAE progression and resulted in more severe tissue destruction. Accordingly, A2aR-deficient mice showed accelerated and exacerbated disease manifestation with increased frequencies of IFN-γ-, IL-17- and GM-CSF-producing CD4(+) T helper cells and higher numbers of inflammatory lesions in the early stage. However, EAE quickly ameliorated and myelin debris accumulation was lower in A2aR(-/-) mice. In vitro, activation of A2aR inhibited phagocytosis of myelin by macrophages and primary microglia as well as migration of CD4(+) T cells, macrophages and primary microglia. CONCLUSIONS: A2aR activation exerts a complex pattern in chronic autoimmune neurodegeneration: while providing anti-inflammatory effects on T cells and thus protection at early stages, A2aR seems to play a detrimental role during later stages of disease and may thus contribute to sustained tissue damage within the inflamed CNS.


Subject(s)
Encephalomyelitis, Autoimmune, Experimental/metabolism , Receptor, Adenosine A2A/metabolism , Adenosine/analogs & derivatives , Adenosine/therapeutic use , Animals , Anti-Inflammatory Agents/therapeutic use , CD4-Positive T-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/metabolism , Cell Movement/drug effects , Cell Movement/genetics , Cell Movement/immunology , Cell Proliferation/drug effects , Cell Proliferation/genetics , Cells, Cultured , Cytokines/metabolism , Disease Models, Animal , Encephalomyelitis, Autoimmune, Experimental/chemically induced , Encephalomyelitis, Autoimmune, Experimental/drug therapy , Encephalomyelitis, Autoimmune, Experimental/pathology , Macrophages/drug effects , Macrophages/metabolism , Mice , Mice, Inbred C57BL , Mice, Transgenic , Microglia/drug effects , Microglia/metabolism , Myelin Proteolipid Protein/toxicity , Myelin-Oligodendrocyte Glycoprotein/toxicity , Peptide Fragments/toxicity , Phagocytosis/drug effects , Phagocytosis/genetics , Phenethylamines/therapeutic use , Receptor, Adenosine A2A/genetics , Time Factors , Up-Regulation/drug effects , Up-Regulation/genetics
13.
Eur Heart J Cardiovasc Imaging ; 16(6): 612-20, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25733209

ABSTRACT

AIM: Inflammation is a hallmark of cardiac healing after myocardial infarction and it determines subsequent cardiovascular morbidity and mortality. The aim of the present study was to explore whether inflammation imaging with two perfluorocarbon (PFC) nanoemulsions and fluorine magnetic resonance imaging ((19)F MRI) is feasible at 3.0 T with sufficient signal-to-noise ratio (SNR) using explanted hearts, an (19)F surface coil and dedicated MR sequences. METHODS AND RESULTS: Acute myocardial infarction (AMI) was induced by balloon angioplasty (50 min) of the distal left anterior descending artery in 12 pigs. One day thereafter, PFCs were injected intravenously to label circulating monocytes. Either emulsified perfluoro-15-crown-5 ether or already clinically applied perfluorooctyl bromide (PFOB) was applied. Four days after AMI and immediately after gadolinium administration, hearts were explanted and imaged with a 3.0 T Achieva MRI scanner. (19)F MRI could be acquired with an SNR of >15 using an in-plane resolution of 2 × 2 mm(2) within <20 min for both agents. Combined late gadolinium enhancement (LGE) and (19)F MRI revealed that (19)F signal was inhomogenously distributed across LGE myocardium reflecting patchy macrophage infiltration as confirmed by histology. In whole hearts, we found an apico-basal (19)F gradient within LGE-positive myocardium. The (19)F-positive volume was always smaller than LGE volume. Ex vivo experiments on isolated monocytes revealed that pig and human cells phagocytize PFCs even more avidly than mouse monocytes. CONCLUSION: This pilot study demonstrates that (19)F MRI at 3.0 T with clinically applicable PFOB is feasible, thus highlighting the potential of (19)F MRI to monitor the inflammatory response after AMI.


Subject(s)
Fluorine-19 Magnetic Resonance Imaging , Myocardial Infarction/pathology , Animals , Contrast Media , Crown Ethers , Fluorocarbons , Gadolinium , Hydrocarbons, Brominated , Imaging, Three-Dimensional , Monocytes , Nanoparticles , Pilot Projects , Signal-To-Noise Ratio , Swine
14.
Internist (Berl) ; 56(2): 195-6, 198-202, 2015 Feb.
Article in German | MEDLINE | ID: mdl-25608999

ABSTRACT

BACKGROUND: Therapy-resistant hypertension is commonly encountered in daily practice. It is present when the therapeutic goal is not achieved after trying at least three antihypertensives from different groups with adequate doses and including a diuretic. Between 10 and 20% of patients are affected and their prognosis is poor. Thus, intensive strategies are required to achieve normotension. DIAGNOSIS: An exact diagnosis is essential. Pseudoresistance needs to be excluded in addition to secondary hypertension and sleep apnea syndrome. The most common cause of pseudoresistance is incorrect blood pressure measurement, false estimation of the real blood pressure level, lack of compliance, unhealthy lifestyle, and drug interactions. Therapeutic resistance should not be diagnosed without 24 h ambulatory blood pressure measurement. This significantly reduces the total number of "resistant" patients. THERAPY: Successful control of blood pressure is achieved in the majority of patients by taking advantage of all possible therapy options. Treatment with 4-6 antihypertensive drugs is justified because of the improvement of cardiovascular prognosis. However, prerequisite is the absence of undesirable side effects which is the most important condition for adequate and reliable patient compliance. Only in the case of failure of the above therapy options can invasive procedures--renal denervation and baroreflex activation therapy--be applied as they are still experimental. Successful management of patients with resistant hypertension is only possible with intensive and time-consuming physician-patient relationships.


Subject(s)
Antihypertensive Agents/administration & dosage , Diuretics/administration & dosage , Hypertension/diagnosis , Hypertension/therapy , Risk Reduction Behavior , Chronic Disease , Humans , Treatment Failure
15.
Exp Clin Endocrinol Diabetes ; 123(2): 118-25, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25393342

ABSTRACT

Class 1A phosphoinositide 3-kinase (PI3K) is essential for beta-cell growth and survival. Although PI3K has been studied extensively in diabetes the effect of alternatively spliced isoforms of the catalytic subunit p85α on beta cell proliferation and survival remains to be defined.We examined expression and signaling of alternatively spliced PI3K regulatory subunits p85α, p55α and p50α in insulinoma cells (INS-1E), an insulin-producing beta cell line. PI3K regulatory isoforms were knocked down by siRNA transfection or overexpressed by adenoviral gene delivery.Knockdown of p85α elevated PI3K activation determined by Akt phosphorylation at baseline and after stimulation with growth factors. In contrast, Akt phosphorylation was inhibited by overexpression of all isoforms of p85α. Correspondingly, p55α and p85α overexpression decreased downstream kinase GSK-3 phosphorylation as well, whereas p50α overexpression resulted in an activation of GSK-3. Moreover, overexpression of p50α and p85α lead to retinoblastoma protein hyperphosphorylation and S-phase entry. Upon challenge of INS-1E cells with a cytotoxic cytokine cocktail, levels of p85α were reduced and p50α was upregulated. Selective overexpression of p50α prevented cytokine induced apoptosis in INS-1E cells.In conclusion, signalling of p50α, p55α and p85α is similar at the level of Akt, but differentially influence downstream GSK-3 activation and cell cycle entry. PI3K isoform p50α induction by cytokines provides a link between regeneration and cell survival under cytotoxic stress in insulin-producing pancreatic beta-cells.


Subject(s)
Cell Survival/physiology , Insulinoma/metabolism , Pancreatic Neoplasms/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Signal Transduction/physiology , Animals , Cell Line, Tumor , Glycogen Synthase Kinase 3/metabolism , Phosphorylation , Rats
16.
Yeast ; 32(1): 145-57, 2015 Jan.
Article in English | MEDLINE | ID: mdl-24910400

ABSTRACT

Trichoderma atroviride IMI 206040 synthesizes the coconut lactone 6-pentyl-α-pyrone (6-PAP) de novo and Aspergillus niger DSM 821 produces the rose-like flavour compound 2-phenylethanol (2-PE) from the precursor l-phenylalanine. Here, microparticles of different chemical composition and nominal particle diameter in the range 5-250 µm were added to shake-flask cultures of both fungi to investigate the particles' effect on product formation. Maximum 2-PE concentration increased by a factor of 1.3 to 1430 mg/l with the addition of 2% w/v talc (40 µm diameter). Maximum 6-PAP concentration increased by a factor of 2 to 40 mg/l with the addition of 2% w/v iron (II, III) oxide. The influence of ions leaching out of the particles was investigated by cultivating the fungi in leached particle medium. For the first time, the positive effect of the microparticle-enhanced cultivation (MPEC) technique on the microbial production of volatile metabolites, here flavour compounds from submerged fungal cultures, is demonstrated. The effect is strain- and particle-specific.


Subject(s)
Aspergillus niger/metabolism , Batch Cell Culture Techniques/methods , Phenylalanine/chemistry , Phenylethyl Alcohol/metabolism , Pyrones/metabolism , Trichoderma/metabolism , Aspergillus niger/genetics , Batch Cell Culture Techniques/instrumentation , Particle Size , Phenylalanine/metabolism , Trichoderma/genetics
17.
Biotechnol Lett ; 36(11): 2193-8, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25048234

ABSTRACT

Prostaglandins (PGs) act as potent local hormones in nearly all tissues of the human body and are used for various medical applications. Heterologous expression of PG endoperoxide H-synthase from the alga, Gracilaria vermiculophylla, into E. coli and the application of this strain in biotransformation experiments resulted in a highly efficient conversion of arachidonic acid (ARA) yielding up to 130 mg natural PGs l(-1) in a laboratory scale approach. Detailed analyses of the products and production kinetics were performed, confirming a rapid conversion of ARA to PGs.


Subject(s)
Biotechnology/methods , Escherichia coli/metabolism , Prostaglandins/analysis , Prostaglandins/metabolism , Arachidonic Acid/metabolism , Bioreactors , Biotransformation , Escherichia coli/genetics , Gracilaria/enzymology , Gracilaria/genetics , Prostaglandin-Endoperoxide Synthases/genetics , Prostaglandin-Endoperoxide Synthases/metabolism , Prostaglandins/genetics
18.
Minerva Gastroenterol Dietol ; 58(4): 401-26, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23207615

ABSTRACT

Pancreatic neuroendocrine tumors originate from the diffuse neuroendocrine system in the pancreatic region. These tumors exhibit a rising incidence despite their rareness and due to their benign behavior a considerable prevalence. Pathogenesis of pancreatic neuroendocrine tumors is characterized by common pathways of hereditary and sporadic tumors. Pancreatic neuroendocrine tumors may secrete peptide hormones or biogenic amines in an autonomous fashion as functional active tumors. Pathological grading and staging by TNM systems has been established in recent years classifying well and moderately differentiated pancreatice neuroendocrine tumors and poorly differentiated neuroendocrine carcinomas. Chromogranin A and less so pancreatic polypeptide are suitable tumor markers for pancreatic neuroendocrine tumors. Expression of receptors for somatostatin is the basis of treatment of pancreatic neuroendocrine tumors with somatostatin analogues as antisecretive and antiproliferative agents. In addition, somatostatin scintigraphy or PET/CT allows comprehensive diagnosis of pancreatic neuroendocrine tumors, which should be supported by (endoscopic and contrast enhanced) ultrasound, CT and MRI. Therapy of pancreatic neuroendocrine tumors consists of somatostatin analogues, chemotherapy, targeted therapy and peptide receptor radionuclide therapy. Two molecular substances hav been registered for pancreatic neuroendocrine tumors recently, sunitinib (Sutent®) and everolimus (Afinitor®). Predominant tumor load in the liver may be treated by local ablative therapy or liver transplantation. These treatment options have been included in guidelines of several professional societies and weighted for sequential therapy of patients with pancreatic neuroendocrine tumors according to effects and side effects.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Neuroendocrine Tumors/diagnosis , Neuroendocrine Tumors/drug therapy , Pancreatic Neoplasms/diagnosis , Pancreatic Neoplasms/drug therapy , Biomarkers/blood , Chromogranin A/blood , Endosonography , Everolimus , Germany/epidemiology , Hepatectomy , Humans , Incidence , Indoles/administration & dosage , Liver Transplantation , Magnetic Resonance Imaging , Multimodal Imaging , Neoplasm Grading , Neoplasm Staging , Neuroendocrine Tumors/blood , Neuroendocrine Tumors/epidemiology , Pancreatic Neoplasms/blood , Pancreatic Neoplasms/epidemiology , Positron-Emission Tomography , Prevalence , Prognosis , Pyrroles/administration & dosage , Sirolimus/administration & dosage , Sirolimus/analogs & derivatives , Somatostatin/analogs & derivatives , Sunitinib , Tomography, X-Ray Computed , Treatment Outcome
20.
Front Immunol ; 3: 87, 2012.
Article in English | MEDLINE | ID: mdl-22586427

ABSTRACT

Most monoclonal antibodies (mAbs) generated from humans infected or vaccinated with the 2009 pandemic H1N1 (pdmH1N1) influenza virus targeted the hemagglutinin (HA) stem. These anti-HA stem mAbs mostly used IGHV1-69 and bound readily to epitopes on the conventional seasonal influenza and pdmH1N1 vaccines. The anti-HA stem mAbs neutralized pdmH1N1, seasonal influenza H1N1 and avian H5N1 influenza viruses by inhibiting HA-mediated fusion of membranes and protected against and treated heterologous lethal infections in mice with H5N1 influenza virus. This demonstrated that therapeutic mAbs could be generated a few months after the new virus emerged. Human immunization with the pdmH1N1 vaccine induced circulating antibodies that when passively transferred, protected mice from lethal, heterologous H5N1 influenza infections. We observed that the dominant heterosubtypic antibody response against the HA stem correlated with the relative absence of memory B cells against the HA head of pdmH1N1, thus enabling the rare heterosubtypic memory B cells induced by seasonal influenza and specific for conserved sites on the HA stem to compete for T-cell help. These results support the notion that broadly protective antibodies against influenza would be induced by successive vaccination with conventional influenza vaccines based on subtypes of HA in viruses not circulating in humans.

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