Ingrid Caceres muller - Academia.edu (original) (raw)

Papers by Ingrid Caceres muller

Journal of diabetes research, 2018

Diabetes self-management education (DSME) is considered essential for improving the prevention an... more Diabetes self-management education (DSME) is considered essential for improving the prevention and care of diabetes through empowering patients to increase agency in their own health and care processes. However, existing evidence regarding DSME in the EU Member States (EU MS) is insufficient to develop an EU-wide strategy. This study presents the state of DSME in the 28 EU MS and contrasts it with 3 non-EU countries with comparable Human Development Index score: Israel, Taiwan, and the USA (ITU). Because type 2 diabetes mellitus (T2DM) disproportionately affects minority and low-income groups, we paid particular attention to health literacy aspects of DSME for vulnerable populations. Data from multiple stakeholders involved in diabetes care were collected from Feb 2014 to Jan 2015 using an online Diabetes Literacy Survey (DLS). Of the 379 respondents (249 from EU MS and 130 from ITU), most were people with diabetes (33% in the EU MS, 15% in ITU) and care providers (47% and 72%). The...

BMJ open, Jan 11, 2018

Vitiligo is a relatively common autoimmune condition causing loss of skin pigment. Around 1 in 10... more Vitiligo is a relatively common autoimmune condition causing loss of skin pigment. Around 1 in 100 people in the UK develop vitiligo. It can have a significant impact on quality of life for many of those affected. How people access information and help for vitiligo may influence how they manage such impact. We aimed to explore people's views and experiences of seeking health information and help for vitiligo. Qualitative analysis of free-text responses to four open-ended questions in an online survey. Online survey conducted in the UK between February and March 2016. A survey link was emailed to 675 members of The Vitiligo Society, a UK-based charity providing information and support for people with vitiligo. One hundred and sixty-one members responded to the survey (24%). Many participants wrote extensive free text, often reporting frustration with help-seeking. They perceived general practitioners (GP) as their primary source of advice but felt that GPs had low awareness of av...

PLoS pathogens, Jan 19, 2018

Leishmania parasites are transmitted to vertebrate hosts by female phlebotomine sand flies as the... more Leishmania parasites are transmitted to vertebrate hosts by female phlebotomine sand flies as they bloodfeed by lacerating the upper capillaries of the dermis with their barbed mouthparts. In the sand fly midgut secreted proteophosphoglycans from Leishmania form a biological plug known as the promastigote secretory gel (PSG), which blocks the gut and facilitates the regurgitation of infective parasites. The interaction between the wound created by the sand fly bite and PSG is not known. Here we nanoinjected a sand fly egested dose of PSG into BALB/c mouse skin that lead to the differential expression of 7,907 transcripts. These transcripts were transiently up-regulated during the first 6 hours post-wound and enriched for pathways involved in inflammation, cell proliferation, fibrosis, epithelial cell differentiation and wound remodelling. We found that PSG significantly accelerated wound healing in vitro and in mice; which was associated with an early up-regulation of transcripts in...

PLOS Neglected Tropical Diseases, 2017

Visceral leishmaniasis (VL) is a neglected tropical disease that affects the poorest communities ... more Visceral leishmaniasis (VL) is a neglected tropical disease that affects the poorest communities and can cause substantial morbidity and mortality. Visceral leishmaniasis is characterized by the presence of Leishmania parasites in the spleen, liver and bone marrow, hepatosplenomegaly, pancytopenia, prolonged fever, systemic inflammation and low body mass index (BMI). The factors impacting on the severity of VL are poorly characterized. Here we performed a cross-sectional study to assess whether co-infection of VL patients with intestinal parasites influences disease severity, assessed with clinical and haematological data, inflammation, cytokine profiles and BMI. Data from VL patients was similar to VL patients co-infected with intestinal parasites, suggesting that co-infection of VL patients with intestinal parasites does not alter disease severity.

PLOS Neglected Tropical Diseases, 2017

Accurate diagnosis of cutaneous leishmaniasis (CL) is important for chemotherapy and epidemiologi... more Accurate diagnosis of cutaneous leishmaniasis (CL) is important for chemotherapy and epidemiological studies. Common approaches for Leishmania detection involve the invasive collection of specimens for direct identification of amastigotes by microscopy and the culturing of promastigotes from infected tissues. Although these techniques are highly specific, they require highly skilled health workers and have the inherent risks of all invasive procedures, such as pain and risk of bacterial and fungal super-infection. Therefore, it is essential to reduce discomfort, potential infection and scarring caused by invasive diagnostic approaches especially for children. In this report, we present a novel noninvasive method, that is painless, rapid and user-friendly, using sequential tape strips for sampling and isolation of DNA from the surface of active and healed skin lesions of CL patients. A total of 119 patients suspected of suffering from cutaneous leishmaniasis with different clinical manifestations were recruited and samples were collected both from their lesions and from uninfected areas. In addition, 15 fungal-infected lesions and 54 areas of healthy skin were examined. The duration of sampling is short (less than one minute) and species identification by PCR is highly specific and sensitive. The sequential tape stripping sampling method is a sensitive, non-invasive and cost-effective alternative to traditional diagnostic assays and it is suitable for field studies as well as for use in health care centers.

Molecules, 2017

Surgical site infections (SSIs) are one of the most common nosocomial infections, which can resul... more Surgical site infections (SSIs) are one of the most common nosocomial infections, which can result in serious complications after surgical interventions. Foreign materials such as implants or surgical sutures are optimal surfaces for the adherence of bacteria and subsequent colonization and biofilm formation. Due to a significant increase in antibiotic-resistant bacterial strains, naturally occurring agents exhibiting antibacterial properties have great potential in prophylactic therapies. The aim of this study was to develop a coating for surgical sutures consisting of the antibacterial substance totarol, a naturally occurring diterpenoid isolated from Podocarpus totara in combination with poly(lactide-co-glycolide acid) (PLGA) as a biodegradable drug delivery system. Hence, non-absorbable monofilament and multifilament sutures were coated with solutions containing different amounts and ratios of totarol and PLGA, resulting in a smooth, crystalline coating. Using an agar diffusion test (ADT), it became evident that the PLGA/totarol-coated sutures inhibited the growth of Staphylococcus aureus over a period of 15 days. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that the coated sutures were not cytotoxic to murine fibroblasts. Overall, the data indicates that our innovative, biodegradable suture coating has the potential to reduce the risk of SSIs and postoperative biofilm-formation on suture material without adverse effects on tissue.

Drug Design, Development and Therapy, 2017

Polypropylene mesh implants are routinely used to repair abdominal wall defects or incisional her... more Polypropylene mesh implants are routinely used to repair abdominal wall defects or incisional hernia. However, complications associated with mesh implantation, such as meshrelated infections, can cause serious problems and may require complete surgical removal. Hence, the aim of the present study was the development of a safe and efficient coating to reduce postoperative mesh infections. Biodegradable poly(lactide-co-glycolide acid) microspheres loaded with rifampicin as an antibacterial agent were prepared through single emulsion evaporation method. The particle size distribution (67.93±3.39 µm for rifampicin-loaded microspheres and 64.43±3.61 µm for unloaded microspheres) was measured by laser diffraction. Furthermore, the encapsulation efficiency of rifampicin (61.5%±2.58%) was detected via ultraviolet-visible (UV/Vis) spectroscopy. The drug release of rifampicin-loaded microspheres was detected by UV/Vis spectroscopy over a period of 60 days. After 60 days, 92.40%±3.54% of the encapsulated rifampicin has been continuously released. The viability of BJ fibroblasts after incubation with unloaded and rifampicin-loaded microspheres was investigated using an MTT (3-(4,5dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, which showed no adverse effects on the cells. Furthermore, the antibacterial impact of rifampicin-loaded microspheres and mesh implants, coated with the antibacterial microspheres, was investigated using an agar diffusion model with Staphylococcus aureus. The coated mesh implants were also tested in an in vivo mouse model of staphylococcal infection and resulted in a 100% protection against mesh implant infections or biofilm formation shown by macroscopic imaging, scanning electron microscopy, and histological examinations. This effective antibacterial mesh coating combining the benefit of a controlled drug delivery system and a potent antibacterial agent possesses the ability to significantly reduce postoperative implant infections.

BMJ open, Jan 4, 2017

The objective of this study was to examine the value of time-driven activity-based costing (TDABC... more The objective of this study was to examine the value of time-driven activity-based costing (TDABC) in understanding the process and costs of delivering diabetes self-management education (DSME) programmes in a multicountry comparative study. Outpatient settings in five European countries (Austria, Denmark, Germany, Ireland, UK) and two countries outside Europe, Taiwan and Israel. Providers of DSME programmes across participating countries (N=16) including healthcare professionals, administrators and patients taking part in DSME programmes. Primary measure: time spent by providers in the delivery of DSME and resources consumed in order to compute programme costs. Secondary measures: self-report measures of behavioural self-management and diabetes disease/health-related outcomes. We found significant variation in costs and the processes of how DSME programmes are provided across and within countries. Variations in costs were driven by a combination of price variances, mix of personnel...

Frontiers in Immunology, 2016

Immunologically, active visceral leishmaniasis (VL) is characterized by profound immunosuppressio... more Immunologically, active visceral leishmaniasis (VL) is characterized by profound immunosuppression, severe systemic inflammatory responses, and an impaired capacity to control parasite replication. Neutrophils are highly versatile cells, which play a crucial role in the induction as well as the resolution of inflammation, the control of pathogen replication, and the regulation of immune responses. Neutrophil functions have been investigated in human cutaneous leishmaniasis; however, their role in human VL is poorly understood. In the present study we evaluated the activation status and effector functions of neutrophils in patients with active VL and after successful anti-leishmanial treatment. Our results show that neutrophils are highly activated and have degranulated; high levels of arginase, myeloperoxidase, and elastase, all contained in neutrophils' granules, were found in the plasma of VL patients. In addition, we show that a large proportion of these cells are immature. We also analyzed effector functions of neutrophils that are essential for pathogen clearance and show that neutrophils have an impaired capacity to release neutrophil extracellular traps, produce reactive oxygen species, and phagocytose bacterial particles, but not Leishmania parasites. Our results suggest that impaired effector functions, increased activation, and immaturity of neutrophils play a key role in the pathogenesis of VL.

Pilot and Feasibility Studies, 2015

Background: This paper provides three illustrations of how the "person-based approach" can be use... more Background: This paper provides three illustrations of how the "person-based approach" can be used to assess and enhance the acceptability and feasibility of an intervention during the early stages of development and evaluation. The person-based approach involves using mixed methods research to systematically investigate the beliefs, attitudes, needs and situation of the people who will be using the intervention. The in-depth understanding of users' perspectives derived from this research then enables intervention developers to design or modify the intervention to make it more relevant, persuasive, accessible and engaging. Methods: The first illustration describes how relevant beliefs and attitudes of people with asthma were identified from the existing qualitative and quantitative literature and then used to create guiding principles to inform the design of a web-based intervention to improve quality of life. The second illustration describes how qualitative "think-aloud" interviews and patient and public involvement (PPI) input are used to improve the acceptability of a booklet for people with asthma. In the third illustration, iterative think-aloud methods are used to create a more accurate and accessible activity planner for people with diabetes. Results: In the first illustration of the person-based approach, we present the guiding principles we developed to summarise key design issues/objectives and key intervention features to address them. The second illustration provides evidence from interviews that positive, non-medical messages and images were preferred in booklet materials for people with asthma. The third illustration demonstrates that people with diabetes found it difficult to complete an online activity planner accurately, resulting in incorrect personalised advice being given prior to appropriate modification of the planner. Conclusions: The person-based approach to intervention development can complement theory-and evidence-based development and participant input into intervention design, offering a systematic process for systematically investigating and incorporating the views of a wide range of users.

Mitteilungen Aus Dem Julius Kuhn Institut, 2009

Atherosclerosis Supplements, 2001

Evidence from in vivo Leishmania spp. infection models have demonstrated that pathology is closel... more Evidence from in vivo Leishmania spp. infection models have demonstrated that pathology is closely associated with the host’s underlying immune response towards the protozoan parasite, including the activation state and parasiticidal ability of Leishmania’s main target cell, the macrophage. We have investigated the role of the host’s immune response in both in vitro and in vivo infection experiments using a metabolic profiling approach, in order to determine interactions between metabolism and immune system in the host specific to Leishmania infection and to identify novel candidate metabolites for diagnostic and immune enhancement for Leishmaniases. Our recent metabolic profiling studies on L. major using 1H nuclear magnetic resonance (NMR) spectroscopy have demonstrated that classical, alternative and non-activated macrophages show different metabolic phenotypes, with the highest cell medium glucose consumption observed in classically activated macrophages. Significantly higher le...

Thrombosis and haemostasis, 2003

The loss of blood through vessel wall ruptures is initially prevented by the rapid adhesion of pl... more The loss of blood through vessel wall ruptures is initially prevented by the rapid adhesion of platelets to the subendothelium, and the formation of a thrombus consisting of platelets and different types of leukocytes. Concomitantly, the coagulation process is thought to be activated by vascular wall tissue factor (TF). Here, a new model for the initiation of coagulation is presented, based on unexpected findings on the presence and functional activation of TF within the blood itself. TF was recently found to be stored in the alpha-granules of resting platelets under physiological conditions. Activation by collagen exposes TF on the platelet cell membrane and on platelet derived microvesicles. Adhesive interactions of the TF bearing platelets and microvesicles to neutrophils and monocytes support the functional activation of the blood based TF. The intravascular TF pathway is proposed to play a significant role during hemostasis by enabling the generation of fibrin at the site of th...

Coatings, 2013

Polyvinylpyrrolidone (PVP) is a conventionally applied hydrophilic lubricious coating on catheter... more Polyvinylpyrrolidone (PVP) is a conventionally applied hydrophilic lubricious coating on catheter-based cardiovascular devices, used in order to ease movement through the vasculature. Its use as drug reservoir and transfer agent on drug-coated balloons (DCB) is therefore extremely promising with regard to the simplification of its approval as a medical device. Here, we developed a PVP-based coating for DCB, containing paclitaxel (PTX) as a model drug, and studied the impact of crosslinking via UV radiation on drug stability, wash off, and transfer during simulated use in an in vitro vessel model. We showed that crosslinking was essential for coating stability and needed to be performed prior to PTX incorporation due to decreased drug bioavailability as a result of photodecomposition and/or involvement in vinylic polymerization with PVP under UV radiation. Moreover, the crosslinking time needed to be carefully controlled. While short radiation times did not provide enough coating stability, associated with high wash off rates during DCB insertion, long radiation times lowered drug transfer efficiency upon balloon expansion. A ten minutes radiation of PVP, however, combined a minimized drug wash off rate of 34% with an

Methods in Microbiology, 2010

ABSTRACT This chapter briefly discusses the leishmaniasis model. The leishmaniases are a group of... more ABSTRACT This chapter briefly discusses the leishmaniasis model. The leishmaniases are a group of vector-borne parasitic diseases that represent a major international public health problem; they belong to the most neglected tropical diseases, are major causes of morbidity and mortality and impede economic development especially in the developing world. The leishmaniases in humans are caused by more than 20 different species of Leishmania parasites. The chapter discusses the various methods, such as parasite isolation and maintenance, maintenance media, and blood agar. Promastigotes of Leishmania spp. can be maintained in different media. The most commonly used media are Schneider's Drosophila Medium (Gibco), Grace's Insect Cell Culture Medium (Gibco), and a biphasic system, consisting of a liquid phase of Dulbecco's Modified Eagle Medium (DMEM, Gibco) over a solid layer of rabbit blood agar. In laboratory one uses the biphasic culture. The DMEM medium used to routinely maintain the parasites in culture is supplemented with the 10% complement inactivated fetal bovine serum (FBS, Gibco). The chapter also explains enumeration of macrophage parasite burden by microscopy.

Transactions of the Royal Society of Tropical Medicine and Hygiene, 2010

Arginase-induced L-arginine deprivation is emerging as a key mechanism for the downregulation of ... more Arginase-induced L-arginine deprivation is emerging as a key mechanism for the downregulation of immune responses. We hypothesised that arginase activity increases with disease severity in HIVseropositive patients. Our results show that peripheral blood mononuclear cells (PBMCs) from 23 HIV-seropositive patients with low CD4 + T cell counts (≤350 cells/μl) expressed significantly more arginase compared with 21 patients with high CD4 + T cell counts. Furthermore, we found a significant association between the two principal prognostic markers used to monitor HIV disease (CD4 + T cell count and plasma viral load) and PBMC arginase activity in antiretroviral therapy naïve patients but not in patients undergoing therapy.

The FASEB Journal, 2003

Although tissue factor (TF), the principial initiator of physiological coagulation and pathologic... more Although tissue factor (TF), the principial initiator of physiological coagulation and pathological thrombosis, has recently been proposed to be present in human blood, the functional significance and location of the intravascular TF is unknown. In the plasma portion of blood, we found TF to be mainly associated with circulating microvesicles. By cell sorting with the specific marker CD42b, platelet-derived microvesicles were identified as a major location of the plasma TF. This was confirmed by the presence of full-length TF in microvesicles acutely shedded from the activated platelets. TF was observed to be stored in the α-granules and the open canalicular system of resting platelets and to be exposed on the cell surface after platelet activation. Functional competence of the blood-based TF was enabled when the microvesicles and platelets adhered to neutrophils, as mediated by P-selectin and neutrophil counterreceptor (PSGL-1, CD18 integrins) interactions. Moreover, neutrophil-secreted oxygen radical species supported the intravascular TF activity. The pools of platelet and microvesicle TF contributed additively and to a comparable extent to the overall blood TF activity, indicating a substantial participation of the microvesicle TF. Our results introduce a new concept of TF-mediated coagulation crucially dependent on TF associated with microvesicles and activated platelets, which principally enables the entire coagulation system to proceed on a restricted cell surface. Key words: lipopolysaccharide • platelet rich plasma • superoxide dismutase • catalase • microparticles T wo principal events that are initiated after disrupture of the endothelial barrier are thought to mark the initiation of hemostasis. Blood platelets adhere to subendothelial collagen providing a provisional, mechanically unstable closure of the vessel perforation. Concomitantly, the coagulation process is started. This is mainly due to the formation of an initiator complex between tissue factor (TF), an integral cell membrane protein predominantly

PLoS ONE, 2012

The mechanisms resulting in progressive immune dysfunction during the chronic phase of HIV infect... more The mechanisms resulting in progressive immune dysfunction during the chronic phase of HIV infection are not fully understood. We have previously shown that arginase, an enzyme with potent immunosuppressive properties, is increased in HIV seropositive (HIV+) patients with low CD4 + T cell counts. Here we show that the cells expressing arginase in peripheral blood mononuclear cells of HIV+ patients are low-density granulocytes (LDGs) and that whereas these cells have a similar morphology to normal-density granulocyte, they are phenotypically different. Importantly, our results reveal that increased frequencies of LDGs correlate with disease severity in HIV+ patients.

PLoS ONE, 2013

Tumor-growth is often associated with the expansion of myeloid derived suppressor cells that lead... more Tumor-growth is often associated with the expansion of myeloid derived suppressor cells that lead to local or systemic arginine depletion via the enzyme arginase. It is generally assumed that this arginine deficiency induces a global shutdown of T cell activation with ensuing tumor immune escape. While the impact of arginine depletion on polyclonal T cell proliferation and cytokine secretion is well documented, its influence on chemotaxis, cytotoxicity and antigen specific activation of human T cells has not been demonstrated so far. We show here that chemotaxis and early calcium signaling of human T cells are unimpaired in the absence of arginine. We then analyzed CD8 + T cell activation in a tumor peptide as well as a viral peptide antigen specific system: (i) CD8 + T cells with specificity against the MART-1 aa26-35*A27L tumor antigen expanded with in vitro generated dendritic cells, and (ii) clonal CMV pp65 aa495-503 specific T cells and T cells retrovirally transduced with a CMV pp65 aa495-503 specific T cell receptor were analyzed. Our data demonstrate that human CD8 + T cell antigen specific cytotoxicity and perforin secretion are completely preserved in the absence of arginine, while antigen specific proliferation as well as IFN-c and granzyme B secretion are severely compromised. These novel results highlight the complexity of antigen specific T cell activation and demonstrate that human T cells can preserve important activationinduced effector functions in the context of arginine deficiency.

Journal of diabetes research, 2018

Diabetes self-management education (DSME) is considered essential for improving the prevention an... more Diabetes self-management education (DSME) is considered essential for improving the prevention and care of diabetes through empowering patients to increase agency in their own health and care processes. However, existing evidence regarding DSME in the EU Member States (EU MS) is insufficient to develop an EU-wide strategy. This study presents the state of DSME in the 28 EU MS and contrasts it with 3 non-EU countries with comparable Human Development Index score: Israel, Taiwan, and the USA (ITU). Because type 2 diabetes mellitus (T2DM) disproportionately affects minority and low-income groups, we paid particular attention to health literacy aspects of DSME for vulnerable populations. Data from multiple stakeholders involved in diabetes care were collected from Feb 2014 to Jan 2015 using an online Diabetes Literacy Survey (DLS). Of the 379 respondents (249 from EU MS and 130 from ITU), most were people with diabetes (33% in the EU MS, 15% in ITU) and care providers (47% and 72%). The...

BMJ open, Jan 11, 2018

Vitiligo is a relatively common autoimmune condition causing loss of skin pigment. Around 1 in 10... more Vitiligo is a relatively common autoimmune condition causing loss of skin pigment. Around 1 in 100 people in the UK develop vitiligo. It can have a significant impact on quality of life for many of those affected. How people access information and help for vitiligo may influence how they manage such impact. We aimed to explore people's views and experiences of seeking health information and help for vitiligo. Qualitative analysis of free-text responses to four open-ended questions in an online survey. Online survey conducted in the UK between February and March 2016. A survey link was emailed to 675 members of The Vitiligo Society, a UK-based charity providing information and support for people with vitiligo. One hundred and sixty-one members responded to the survey (24%). Many participants wrote extensive free text, often reporting frustration with help-seeking. They perceived general practitioners (GP) as their primary source of advice but felt that GPs had low awareness of av...

PLoS pathogens, Jan 19, 2018

Leishmania parasites are transmitted to vertebrate hosts by female phlebotomine sand flies as the... more Leishmania parasites are transmitted to vertebrate hosts by female phlebotomine sand flies as they bloodfeed by lacerating the upper capillaries of the dermis with their barbed mouthparts. In the sand fly midgut secreted proteophosphoglycans from Leishmania form a biological plug known as the promastigote secretory gel (PSG), which blocks the gut and facilitates the regurgitation of infective parasites. The interaction between the wound created by the sand fly bite and PSG is not known. Here we nanoinjected a sand fly egested dose of PSG into BALB/c mouse skin that lead to the differential expression of 7,907 transcripts. These transcripts were transiently up-regulated during the first 6 hours post-wound and enriched for pathways involved in inflammation, cell proliferation, fibrosis, epithelial cell differentiation and wound remodelling. We found that PSG significantly accelerated wound healing in vitro and in mice; which was associated with an early up-regulation of transcripts in...

PLOS Neglected Tropical Diseases, 2017

Visceral leishmaniasis (VL) is a neglected tropical disease that affects the poorest communities ... more Visceral leishmaniasis (VL) is a neglected tropical disease that affects the poorest communities and can cause substantial morbidity and mortality. Visceral leishmaniasis is characterized by the presence of Leishmania parasites in the spleen, liver and bone marrow, hepatosplenomegaly, pancytopenia, prolonged fever, systemic inflammation and low body mass index (BMI). The factors impacting on the severity of VL are poorly characterized. Here we performed a cross-sectional study to assess whether co-infection of VL patients with intestinal parasites influences disease severity, assessed with clinical and haematological data, inflammation, cytokine profiles and BMI. Data from VL patients was similar to VL patients co-infected with intestinal parasites, suggesting that co-infection of VL patients with intestinal parasites does not alter disease severity.

PLOS Neglected Tropical Diseases, 2017

Accurate diagnosis of cutaneous leishmaniasis (CL) is important for chemotherapy and epidemiologi... more Accurate diagnosis of cutaneous leishmaniasis (CL) is important for chemotherapy and epidemiological studies. Common approaches for Leishmania detection involve the invasive collection of specimens for direct identification of amastigotes by microscopy and the culturing of promastigotes from infected tissues. Although these techniques are highly specific, they require highly skilled health workers and have the inherent risks of all invasive procedures, such as pain and risk of bacterial and fungal super-infection. Therefore, it is essential to reduce discomfort, potential infection and scarring caused by invasive diagnostic approaches especially for children. In this report, we present a novel noninvasive method, that is painless, rapid and user-friendly, using sequential tape strips for sampling and isolation of DNA from the surface of active and healed skin lesions of CL patients. A total of 119 patients suspected of suffering from cutaneous leishmaniasis with different clinical manifestations were recruited and samples were collected both from their lesions and from uninfected areas. In addition, 15 fungal-infected lesions and 54 areas of healthy skin were examined. The duration of sampling is short (less than one minute) and species identification by PCR is highly specific and sensitive. The sequential tape stripping sampling method is a sensitive, non-invasive and cost-effective alternative to traditional diagnostic assays and it is suitable for field studies as well as for use in health care centers.

Molecules, 2017

Surgical site infections (SSIs) are one of the most common nosocomial infections, which can resul... more Surgical site infections (SSIs) are one of the most common nosocomial infections, which can result in serious complications after surgical interventions. Foreign materials such as implants or surgical sutures are optimal surfaces for the adherence of bacteria and subsequent colonization and biofilm formation. Due to a significant increase in antibiotic-resistant bacterial strains, naturally occurring agents exhibiting antibacterial properties have great potential in prophylactic therapies. The aim of this study was to develop a coating for surgical sutures consisting of the antibacterial substance totarol, a naturally occurring diterpenoid isolated from Podocarpus totara in combination with poly(lactide-co-glycolide acid) (PLGA) as a biodegradable drug delivery system. Hence, non-absorbable monofilament and multifilament sutures were coated with solutions containing different amounts and ratios of totarol and PLGA, resulting in a smooth, crystalline coating. Using an agar diffusion test (ADT), it became evident that the PLGA/totarol-coated sutures inhibited the growth of Staphylococcus aureus over a period of 15 days. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that the coated sutures were not cytotoxic to murine fibroblasts. Overall, the data indicates that our innovative, biodegradable suture coating has the potential to reduce the risk of SSIs and postoperative biofilm-formation on suture material without adverse effects on tissue.

Drug Design, Development and Therapy, 2017

Polypropylene mesh implants are routinely used to repair abdominal wall defects or incisional her... more Polypropylene mesh implants are routinely used to repair abdominal wall defects or incisional hernia. However, complications associated with mesh implantation, such as meshrelated infections, can cause serious problems and may require complete surgical removal. Hence, the aim of the present study was the development of a safe and efficient coating to reduce postoperative mesh infections. Biodegradable poly(lactide-co-glycolide acid) microspheres loaded with rifampicin as an antibacterial agent were prepared through single emulsion evaporation method. The particle size distribution (67.93±3.39 µm for rifampicin-loaded microspheres and 64.43±3.61 µm for unloaded microspheres) was measured by laser diffraction. Furthermore, the encapsulation efficiency of rifampicin (61.5%±2.58%) was detected via ultraviolet-visible (UV/Vis) spectroscopy. The drug release of rifampicin-loaded microspheres was detected by UV/Vis spectroscopy over a period of 60 days. After 60 days, 92.40%±3.54% of the encapsulated rifampicin has been continuously released. The viability of BJ fibroblasts after incubation with unloaded and rifampicin-loaded microspheres was investigated using an MTT (3-(4,5dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, which showed no adverse effects on the cells. Furthermore, the antibacterial impact of rifampicin-loaded microspheres and mesh implants, coated with the antibacterial microspheres, was investigated using an agar diffusion model with Staphylococcus aureus. The coated mesh implants were also tested in an in vivo mouse model of staphylococcal infection and resulted in a 100% protection against mesh implant infections or biofilm formation shown by macroscopic imaging, scanning electron microscopy, and histological examinations. This effective antibacterial mesh coating combining the benefit of a controlled drug delivery system and a potent antibacterial agent possesses the ability to significantly reduce postoperative implant infections.

BMJ open, Jan 4, 2017

The objective of this study was to examine the value of time-driven activity-based costing (TDABC... more The objective of this study was to examine the value of time-driven activity-based costing (TDABC) in understanding the process and costs of delivering diabetes self-management education (DSME) programmes in a multicountry comparative study. Outpatient settings in five European countries (Austria, Denmark, Germany, Ireland, UK) and two countries outside Europe, Taiwan and Israel. Providers of DSME programmes across participating countries (N=16) including healthcare professionals, administrators and patients taking part in DSME programmes. Primary measure: time spent by providers in the delivery of DSME and resources consumed in order to compute programme costs. Secondary measures: self-report measures of behavioural self-management and diabetes disease/health-related outcomes. We found significant variation in costs and the processes of how DSME programmes are provided across and within countries. Variations in costs were driven by a combination of price variances, mix of personnel...

Frontiers in Immunology, 2016

Immunologically, active visceral leishmaniasis (VL) is characterized by profound immunosuppressio... more Immunologically, active visceral leishmaniasis (VL) is characterized by profound immunosuppression, severe systemic inflammatory responses, and an impaired capacity to control parasite replication. Neutrophils are highly versatile cells, which play a crucial role in the induction as well as the resolution of inflammation, the control of pathogen replication, and the regulation of immune responses. Neutrophil functions have been investigated in human cutaneous leishmaniasis; however, their role in human VL is poorly understood. In the present study we evaluated the activation status and effector functions of neutrophils in patients with active VL and after successful anti-leishmanial treatment. Our results show that neutrophils are highly activated and have degranulated; high levels of arginase, myeloperoxidase, and elastase, all contained in neutrophils' granules, were found in the plasma of VL patients. In addition, we show that a large proportion of these cells are immature. We also analyzed effector functions of neutrophils that are essential for pathogen clearance and show that neutrophils have an impaired capacity to release neutrophil extracellular traps, produce reactive oxygen species, and phagocytose bacterial particles, but not Leishmania parasites. Our results suggest that impaired effector functions, increased activation, and immaturity of neutrophils play a key role in the pathogenesis of VL.

Pilot and Feasibility Studies, 2015

Background: This paper provides three illustrations of how the "person-based approach" can be use... more Background: This paper provides three illustrations of how the "person-based approach" can be used to assess and enhance the acceptability and feasibility of an intervention during the early stages of development and evaluation. The person-based approach involves using mixed methods research to systematically investigate the beliefs, attitudes, needs and situation of the people who will be using the intervention. The in-depth understanding of users' perspectives derived from this research then enables intervention developers to design or modify the intervention to make it more relevant, persuasive, accessible and engaging. Methods: The first illustration describes how relevant beliefs and attitudes of people with asthma were identified from the existing qualitative and quantitative literature and then used to create guiding principles to inform the design of a web-based intervention to improve quality of life. The second illustration describes how qualitative "think-aloud" interviews and patient and public involvement (PPI) input are used to improve the acceptability of a booklet for people with asthma. In the third illustration, iterative think-aloud methods are used to create a more accurate and accessible activity planner for people with diabetes. Results: In the first illustration of the person-based approach, we present the guiding principles we developed to summarise key design issues/objectives and key intervention features to address them. The second illustration provides evidence from interviews that positive, non-medical messages and images were preferred in booklet materials for people with asthma. The third illustration demonstrates that people with diabetes found it difficult to complete an online activity planner accurately, resulting in incorrect personalised advice being given prior to appropriate modification of the planner. Conclusions: The person-based approach to intervention development can complement theory-and evidence-based development and participant input into intervention design, offering a systematic process for systematically investigating and incorporating the views of a wide range of users.

Mitteilungen Aus Dem Julius Kuhn Institut, 2009

Atherosclerosis Supplements, 2001

Evidence from in vivo Leishmania spp. infection models have demonstrated that pathology is closel... more Evidence from in vivo Leishmania spp. infection models have demonstrated that pathology is closely associated with the host’s underlying immune response towards the protozoan parasite, including the activation state and parasiticidal ability of Leishmania’s main target cell, the macrophage. We have investigated the role of the host’s immune response in both in vitro and in vivo infection experiments using a metabolic profiling approach, in order to determine interactions between metabolism and immune system in the host specific to Leishmania infection and to identify novel candidate metabolites for diagnostic and immune enhancement for Leishmaniases. Our recent metabolic profiling studies on L. major using 1H nuclear magnetic resonance (NMR) spectroscopy have demonstrated that classical, alternative and non-activated macrophages show different metabolic phenotypes, with the highest cell medium glucose consumption observed in classically activated macrophages. Significantly higher le...

Thrombosis and haemostasis, 2003

The loss of blood through vessel wall ruptures is initially prevented by the rapid adhesion of pl... more The loss of blood through vessel wall ruptures is initially prevented by the rapid adhesion of platelets to the subendothelium, and the formation of a thrombus consisting of platelets and different types of leukocytes. Concomitantly, the coagulation process is thought to be activated by vascular wall tissue factor (TF). Here, a new model for the initiation of coagulation is presented, based on unexpected findings on the presence and functional activation of TF within the blood itself. TF was recently found to be stored in the alpha-granules of resting platelets under physiological conditions. Activation by collagen exposes TF on the platelet cell membrane and on platelet derived microvesicles. Adhesive interactions of the TF bearing platelets and microvesicles to neutrophils and monocytes support the functional activation of the blood based TF. The intravascular TF pathway is proposed to play a significant role during hemostasis by enabling the generation of fibrin at the site of th...

Coatings, 2013

Polyvinylpyrrolidone (PVP) is a conventionally applied hydrophilic lubricious coating on catheter... more Polyvinylpyrrolidone (PVP) is a conventionally applied hydrophilic lubricious coating on catheter-based cardiovascular devices, used in order to ease movement through the vasculature. Its use as drug reservoir and transfer agent on drug-coated balloons (DCB) is therefore extremely promising with regard to the simplification of its approval as a medical device. Here, we developed a PVP-based coating for DCB, containing paclitaxel (PTX) as a model drug, and studied the impact of crosslinking via UV radiation on drug stability, wash off, and transfer during simulated use in an in vitro vessel model. We showed that crosslinking was essential for coating stability and needed to be performed prior to PTX incorporation due to decreased drug bioavailability as a result of photodecomposition and/or involvement in vinylic polymerization with PVP under UV radiation. Moreover, the crosslinking time needed to be carefully controlled. While short radiation times did not provide enough coating stability, associated with high wash off rates during DCB insertion, long radiation times lowered drug transfer efficiency upon balloon expansion. A ten minutes radiation of PVP, however, combined a minimized drug wash off rate of 34% with an

Methods in Microbiology, 2010

ABSTRACT This chapter briefly discusses the leishmaniasis model. The leishmaniases are a group of... more ABSTRACT This chapter briefly discusses the leishmaniasis model. The leishmaniases are a group of vector-borne parasitic diseases that represent a major international public health problem; they belong to the most neglected tropical diseases, are major causes of morbidity and mortality and impede economic development especially in the developing world. The leishmaniases in humans are caused by more than 20 different species of Leishmania parasites. The chapter discusses the various methods, such as parasite isolation and maintenance, maintenance media, and blood agar. Promastigotes of Leishmania spp. can be maintained in different media. The most commonly used media are Schneider's Drosophila Medium (Gibco), Grace's Insect Cell Culture Medium (Gibco), and a biphasic system, consisting of a liquid phase of Dulbecco's Modified Eagle Medium (DMEM, Gibco) over a solid layer of rabbit blood agar. In laboratory one uses the biphasic culture. The DMEM medium used to routinely maintain the parasites in culture is supplemented with the 10% complement inactivated fetal bovine serum (FBS, Gibco). The chapter also explains enumeration of macrophage parasite burden by microscopy.

Transactions of the Royal Society of Tropical Medicine and Hygiene, 2010

Arginase-induced L-arginine deprivation is emerging as a key mechanism for the downregulation of ... more Arginase-induced L-arginine deprivation is emerging as a key mechanism for the downregulation of immune responses. We hypothesised that arginase activity increases with disease severity in HIVseropositive patients. Our results show that peripheral blood mononuclear cells (PBMCs) from 23 HIV-seropositive patients with low CD4 + T cell counts (≤350 cells/μl) expressed significantly more arginase compared with 21 patients with high CD4 + T cell counts. Furthermore, we found a significant association between the two principal prognostic markers used to monitor HIV disease (CD4 + T cell count and plasma viral load) and PBMC arginase activity in antiretroviral therapy naïve patients but not in patients undergoing therapy.

The FASEB Journal, 2003

Although tissue factor (TF), the principial initiator of physiological coagulation and pathologic... more Although tissue factor (TF), the principial initiator of physiological coagulation and pathological thrombosis, has recently been proposed to be present in human blood, the functional significance and location of the intravascular TF is unknown. In the plasma portion of blood, we found TF to be mainly associated with circulating microvesicles. By cell sorting with the specific marker CD42b, platelet-derived microvesicles were identified as a major location of the plasma TF. This was confirmed by the presence of full-length TF in microvesicles acutely shedded from the activated platelets. TF was observed to be stored in the α-granules and the open canalicular system of resting platelets and to be exposed on the cell surface after platelet activation. Functional competence of the blood-based TF was enabled when the microvesicles and platelets adhered to neutrophils, as mediated by P-selectin and neutrophil counterreceptor (PSGL-1, CD18 integrins) interactions. Moreover, neutrophil-secreted oxygen radical species supported the intravascular TF activity. The pools of platelet and microvesicle TF contributed additively and to a comparable extent to the overall blood TF activity, indicating a substantial participation of the microvesicle TF. Our results introduce a new concept of TF-mediated coagulation crucially dependent on TF associated with microvesicles and activated platelets, which principally enables the entire coagulation system to proceed on a restricted cell surface. Key words: lipopolysaccharide • platelet rich plasma • superoxide dismutase • catalase • microparticles T wo principal events that are initiated after disrupture of the endothelial barrier are thought to mark the initiation of hemostasis. Blood platelets adhere to subendothelial collagen providing a provisional, mechanically unstable closure of the vessel perforation. Concomitantly, the coagulation process is started. This is mainly due to the formation of an initiator complex between tissue factor (TF), an integral cell membrane protein predominantly

PLoS ONE, 2012

The mechanisms resulting in progressive immune dysfunction during the chronic phase of HIV infect... more The mechanisms resulting in progressive immune dysfunction during the chronic phase of HIV infection are not fully understood. We have previously shown that arginase, an enzyme with potent immunosuppressive properties, is increased in HIV seropositive (HIV+) patients with low CD4 + T cell counts. Here we show that the cells expressing arginase in peripheral blood mononuclear cells of HIV+ patients are low-density granulocytes (LDGs) and that whereas these cells have a similar morphology to normal-density granulocyte, they are phenotypically different. Importantly, our results reveal that increased frequencies of LDGs correlate with disease severity in HIV+ patients.

PLoS ONE, 2013

Tumor-growth is often associated with the expansion of myeloid derived suppressor cells that lead... more Tumor-growth is often associated with the expansion of myeloid derived suppressor cells that lead to local or systemic arginine depletion via the enzyme arginase. It is generally assumed that this arginine deficiency induces a global shutdown of T cell activation with ensuing tumor immune escape. While the impact of arginine depletion on polyclonal T cell proliferation and cytokine secretion is well documented, its influence on chemotaxis, cytotoxicity and antigen specific activation of human T cells has not been demonstrated so far. We show here that chemotaxis and early calcium signaling of human T cells are unimpaired in the absence of arginine. We then analyzed CD8 + T cell activation in a tumor peptide as well as a viral peptide antigen specific system: (i) CD8 + T cells with specificity against the MART-1 aa26-35*A27L tumor antigen expanded with in vitro generated dendritic cells, and (ii) clonal CMV pp65 aa495-503 specific T cells and T cells retrovirally transduced with a CMV pp65 aa495-503 specific T cell receptor were analyzed. Our data demonstrate that human CD8 + T cell antigen specific cytotoxicity and perforin secretion are completely preserved in the absence of arginine, while antigen specific proliferation as well as IFN-c and granzyme B secretion are severely compromised. These novel results highlight the complexity of antigen specific T cell activation and demonstrate that human T cells can preserve important activationinduced effector functions in the context of arginine deficiency.