The association between iron deficiency and outcomes: a secondary analysis of the intravenous iron therapy to treat iron deficiency anaemia in patients undergoing major abdominal surgery (PREVENTT) trial.

In the intravenous iron therapy to treat iron deficiency anaemia in patients undergoing major abdominal surgery (PREVENTT) trial, the use of intravenous iron did not reduce the need for blood transfusion or reduce patient complications or length of hospital stay. As part of the trial protocol, serum was collected at randomisation and on the day of surgery. These samples were analysed in a central laboratory for markers of iron deficiency. We performed a secondary analysis to explore the potential interactions between pre-operative markers of iron deficiency and intervention status on the trial outcome measures. Absolute iron deficiency was defined as ferritin <30 µg.l-1 ; functional iron deficiency as ferritin 30-100 µg.l-1 or transferrin saturation < 20%; and the remainder as non-iron deficient. Interactions were estimated using generalised linear models that included different subgroup indicators of baseline iron status. Co-primary endpoints were blood transfusion or death and number of blood transfusions, from randomisation to 30 days postoperatively. Secondary endpoints included peri-operative change in haemoglobin, postoperative complications and length of hospital stay. Most patients had iron deficiency (369/452 [82%]) at randomisation; one-third had absolute iron deficiency (144/452 [32%]) and half had functional iron deficiency (225/452 [50%]). The change in pre-operative haemoglobin with intravenous iron compared with placebo was greatest in patients with absolute iron deficiency, mean difference 8.9 g.l-1 , 95%CI 5.3-12.5; moderate in functional iron deficiency, mean difference 2.8 g.l-1 , 95%CI -0.1 to 5.7; and with little change seen in those patients who were non-iron deficient. Subgroup analyses did not suggest that intravenous iron compared with placebo reduced the likelihood of death or blood transfusion at 30 days differentially across subgroups according to baseline ferritin (p = 0.33 for interaction), transferrin saturation (p = 0.13) or in combination (p = 0.45), or for the number of blood transfusions (p = 0.06, 0.29, and 0.39, respectively). There was no beneficial effect of the use of intravenous iron compared with placebo, regardless of the metrics to diagnose iron deficiency, on postoperative complications or length of hospital stay.

Correction to: Heparin resistance in COVID­19 patients in the intensive care unit.

In the original publication of this article, one of the co-author name "D. de Monteverde-Robb" was inadvertently mentioned as "R. de Monteverde-Robb". The correct author name is "D. de Monteverde-Robb". This error has been corrected with this erratum.

Heparin resistance in COVID-19 patients in the intensive care unit.

Patients with COVID-19 have a coagulopathy and high thrombotic risk. In a cohort of 69 intensive care unit (ICU) patients we investigated for evidence of heparin resistance in those that have received therapeutic anticoagulation. 15 of the patients have received therapeutic anticoagulation with either unfractionated heparin (UFH) or low molecular weight heparin (LMWH), of which full information was available on 14 patients. Heparin resistance to UFH was documented in 8/10 (80%) patients and sub-optimal peak anti-Xa following therapeutic LMWH in 5/5 (100%) patients where this was measured (some patients received both anticoagulants sequentially). Spiking plasma from 12 COVID-19 ICU patient samples demonstrated decreased in-vitro recovery of anti-Xa compared to normal pooled plasma. In conclusion, we have found evidence of heparin resistance in critically unwell COVID-19 patients. Further studies investigating this are required to determine the optimal thromboprophylaxis in COVID-19 and management of thrombotic episodes.

Clinical utility of the Quantra® point-of-care haemostasis analyser during urgent cardiac surgery.

Coagulopathic bleeding during and after cardiac surgery is associated with increased morbidity and mortality. Viscoelastic testing is increasingly used instead of laboratory testing. Our aim was to compare a new viscoelastic point-of-care device, the Quantra® System, with thromboelastography and standard laboratory testing. After ethical approval and with written informed consent, we prospectively recruited adult patients undergoing urgent cardiac surgery at increased risk of bleeding. Clot time and clot stiffness values were compared before, during and after cardiopulmonary bypass. We prospectively recruited 52 patients, of whom 34 (65%) were transfused with red blood cells. Our usual transfusion thresholds for fibrinogen (1.5 g.l-1 ), platelets (100,000.µl-1 ), prothrombin time (20 s), activated partial thromboplastin time (48 s) and maximum amplitude on thromboelastography (50 mm) corresponded to Quantra values of fibrinogen clot stiffness 2.0 hPa, platelet clot stiffness 13.5 hPa, clot time 159 s, clot time 183 s and clot stiffness 17.0 hPa, respectively. These Quantra thresholds showed high negative predictive value for low platelets (platelet clot stiffness, 97.4%), prolonged activated partial thromboplastin time (clot time, 92.6%) and reduced maximum amplitude on thromboelastography (clot stiffness, 93.6%). The Quantra predicted clinical need for transfusion of platelets (area under the curve 0.71, p = 0.001) but all tests performed poorly at predicting the need for fresh frozen plasma transfusion. We have shown that point-of-care testing using the novel Quantra system provides useful data for guiding transfusion management.

Efficacy of adoptive therapy with tumor-infiltrating lymphocytes and recombinant interleukin-2 in advanced cutaneous melanoma: a systematic review and meta-analysis.

Adoptive cell therapy (ACT) using autologous tumor-infiltrating lymphocytes (TIL) has been tested in advanced melanoma patients at various centers. We conducted a systematic review and meta-analysis to assess its efficacy on previously treated advanced metastatic cutaneous melanoma. The PubMed electronic database was searched from inception to 17 December 2018 to identify studies administering TIL-ACT and recombinant interleukin-2 (IL-2) following non-myeloablative chemotherapy in previously treated metastatic melanoma patients. Objective response rate (ORR) was the primary end point. Secondary end points were complete response rate (CRR), overall survival (OS), duration of response (DOR) and toxicity. Pooled estimates were derived from fixed or random effect models, depending on the amount of heterogeneity detected. Analysis was carried out separately for high dose (HD) and low dose (LD) IL-2. Sensitivity analyses were carried out. Among 1211 records screened, 13 studies (published 1988 - 2016) were eligible for meta-analysis. Among 410 heavily pretreated patients (some with brain metastasis), 332 received HD-IL-2 and 78 LD-IL-2. The pooled overall ORR estimate was 41% [95% confidence interval (CI) 35% to 48%], and the overall CRR was 12% (95% CI 7% to 16%). For the HD-IL-2 group, the ORR was 43% (95% CI 36% to 50%), while for the LD-IL-2 it was 35% (95% CI 25% to 45%). Corresponding pooled estimates for CRR were 14% (95% CI 7% to 20%) and 7% (95% CI 1% to 12%). The majority of HD-IL-2 complete responders (27/28) remained in remission during the extent of follow-up after CR (median 40 months). Sensitivity analyses yielded similar results. Higher number of infused cells was associated with a favorable response. The ORR for HD-IL-2 compared favorably with the nivolumab/ipilimumab combination following anti-PD-1 failure. TIL-ACT therapy, especially when combined with HD-IL-2, achieves durable clinical benefit and warrants further investigation. We discuss the current position of TIL-ACT in the therapy of advanced melanoma, particularly in the era of immune checkpoint blockade therapy, and review future opportunities for improvement of this approach.

Impact of probiotics on pathogen survival in an innovative human plasma biofilm model (hpBIOM).

BACKGROUND: Despite of medical advances, the number of patients suffering on non-healing chronic wounds is still increasing. This fact is attended by physical and emotional distress and an economic load. The majority of chronic wounds are infected of harmful microbials in a protecting extracellular matrix. These biofilms inhibit wound healing. Biofilm-growing bacteria developed unique survival properties, which still challenge the appropriate wound therapy. The present in-vitro biofilm models are not suitable for translational research. By means of a novel in-vivo like human plasma biofilm model (hpBIOM), this study systematically analysed the influence of 3 probiotics on the survival of five clinically relevant pathogenic microorganisms. METHODS: Human plasma was used to produce the innovate biofilm. Pathogenic microorganisms were administered to the plasma. By stimulating the production of a fibrin scaffold, stable coagula-like discs with integrated pathogens were produced. The five clinically relevant pathogens P. aeruginosa, S. aureus, S. epidermidis, E. faecium and C. albicans were challenged to the probiotics L. plantarum, B. lactis and S. cerevisiae. The probiotics were administered on top of the biofilm and the survival was quantified after 4 h and 24 h of incubation. For statistics, two-way ANOVA with post-hoc Tukey's HSD test was applied. P-value > 0.05 was considered to be significant. RESULTS: SEM micrographs depicted the pathogens on the surface of the fibrin scaffold, arranged in close proximity and produced the glycocalyx. The application of probiotics induced different growth-reducing capacities towards the pathogens. B. lactis and S. cerevisiae showed slight bacteria-reducing properties. The survival of C. albicans was not affected at all. The most antimicrobial activity was detected after the treatment with L. plantarum. CONCLUSIONS: This study successfully reproduced a novel human biofilm model, which provides a human wound milieu and individual immune competence. The success of bacteriotherapy is dependent on the strain combination, the number of probiotics and the activity of the immune cells. The eradicating effect of L. plantarum on P. aeruginosa should be emphasized.

International consensus statement on the peri-operative management of anaemia and iron deficiency.

Despite current recommendations on the management of pre-operative anaemia, there is no pragmatic guidance for the diagnosis and management of anaemia and iron deficiency in surgical patients. A number of experienced researchers and clinicians took part in an expert workshop and developed the following consensus statement. After presentation of our own research data and local policies and procedures, appropriate relevant literature was reviewed and discussed. We developed a series of best-practice and evidence-based statements to advise on patient care with respect to anaemia and iron deficiency in the peri-operative period. These statements include: a diagnostic approach for anaemia and iron deficiency in surgical patients; identification of patients appropriate for treatment; and advice on practical management and follow-up. We urge anaesthetists and peri-operative physicians to embrace these recommendations, and hospital administrators to enable implementation of these concepts by allocating adequate resources.

Peripheral blood-derived, γ9δ2 t cell-enriched cell lines from glioblastoma multiforme patients exert anti-tumoral effects in vitro.

The goal of this work was to assess the potential of T cells expressing Vγ9Vδ2+ T cell receptors (TCR, γ9δ2T cells) present in peripheral blood (PB) m ononuclear cells (MC, PBMC) of glioblastoma multiforme (GBM) patients to act as anti-tumoral agents. We found that γ9δ2T cell levels were decreased in patients' PB relative to a cohort of healthy donors (HD) (respectively 0.52±0.55%, n=16, vs 1.12±0.6%, n=14, p=0.008) but did not significantly correlate with postoperative survival (R=0.6, p=0.063). Importantly, however, the γ9δ2T cells could be expanded in vitro to consist 51±23% of the cultured lymphocytes (98% CD3+). This was achieved after 14 days of culture in medium containing the amino-bisphosphonate (ABP) Zoledronate (Zol) and interleukin (IL)-2, resulting in γ9δ2T cell-enriched lines (gdTCEL) similar to those of HD derived gdTCEL (54±19%). Moreover, gdTCEL from patients and HD mediated cytotoxicity to GBM-derived cell lines (GBMDCL), which was abrogated by immune-magnetic removal of the γ9δ2T cells. Furthermore, low level interferon (IFN) γ secretion was induced by gdTCEL briefly co-cultured with GBMDCL or autologous - tumor-derived cells, which was greatly amplified in the presence of Zol. Importantly, IFNγ secretion was inhibited by mevastatin but enhanced by cross-linking of butyrophilin 3A1 (CD277) on a CD277+ GBMDCL (U251MG) or by pretreatment of GBMDCL with temozolomide (TMZ). Taken together, these data suggest that γ9δ2T cells in PB of GBM patients can give rise to gdTCEL that mediate anti-tumoral activities.

Haemostatic management of cardiac surgical haemorrhage.

Almost 30,000 cardiopulmonary bypass operations are performed in the UK every year, consuming a considerable portion of the UK blood supply. Each year, in cardiac surgery, 90% of blood products are used by only 10% of patients, and over the past 25 years, much innovation and research has gone into improving peri-operative diagnosis and therapy for these patients. Visco-elastic tests performed at the bedside, with modifications to allow direct quantification of fibrinogen levels, are probably the biggest advancement. There is no clear advantage of thromboelastometry over thromboelastography, and the published literature remains scarce. Visco-elastic testing has recently been coupled with the systematic replacement of clotting factors by means of factor concentrates, with objective improvement in terms of blood loss, red blood cell usage and surgical re-exploration. The National Institute for Health and Care Excellence has reviewed the available evidence and recommended visco-elastic tests as cost effective in cardiac surgery. Factor concentrates, however, carry significant risks, particularly unnecessary donor exposures, potential selective over-correction of partial deficiencies and the possibility that the postoperative risk of venous thromboembolism is increased; as yet there are no data on risk-benefit analysis. There are a number of promising drugs used in topical haemostasis, but the requirement to apply these before major bleeding is manifest limits their use considerably. Hyperfibrinolysis is less important than in the past due to the wide spread adoption of antifibrinolytic agents and close intra-operative monitoring of heparin effect.

Haemoconcentration of residual cardiopulmonary bypass blood using Hemosep ®: a randomised controlled trial.

Cardiac surgery and cardiopulmonary bypass are associated with haemodilution, activation of haemostasis and blood transfusion. We undertook a randomised controlled trial that included 53 patients in order to compare autotransfusion of residual cardiopulmonary bypass blood with residual blood concentrated using the novel Hemosep(®) device. There was no difference in patients' mean (SD) haemoglobin concentration after autotransfusion of unprocessed blood compared with Hemosep; 103.5 (10.2) g.l(-1) vs 106.2 (12.4) g.l(-1), respectively, p = 0.40. The mean (SD) change in haemoglobin concentration after autotransfusion was 5.9 (5.3) g.l(-1) in the control group compared with 4.9 (6.3) g.l(-1) in the Hemosep group, p = 0.545. Adjusted for baseline haemoglobin concentrations, the estimated mean (95% CI) difference in change in haemoglobin concentration (control vs Hemosep) was 0.57 (-2.65 to 3.79) g.l(-1), p = 0.72. This was despite Hemosep's reducing the weight of the blood from a mean (SD) of 778.7 (243.0) g to 607.3 (248.2) g, p < 0.001. The haemoglobin concentration in the processed blood increased from a mean (SD) of 87.0 (15.1) g.l(-1) to 103.7 (17.4) g.l(-1), p < 0.001. We conclude that Hemosep is capable of haemoconcentration when employed to process residual cardiopulmonary bypass blood, but that this is insufficient to increase patient haemoglobin.

Antifibrinolytic agents in current anaesthetic practice.

Antifibrinolytic drugs have become almost ubiquitous in their use during major surgery when bleeding is expected or commonplace. Inhibition of the fibrinolytic pathway after tissue injury has been consistently shown to reduce postoperative or traumatic bleeding. There is also some evidence for a reduction of perioperative blood transfusion. However, evidence of complications associated with exaggerated thrombosis also exists, although this appears to be influenced by the choice of the individual agent and the dose administered. There is controversy over the use of the serine protease inhibitor aprotinin, whose license was recently withdrawn but may shortly become available on the market again. In the UK, tranexamic acid, a tissue plasminogen and plasmin inhibitor, is most commonly used, with evidence for benefit in cardiac, orthopaedic, urological, gynaecological, and obstetric surgery. In the USA, ε-aminocaproic acid, which also inhibits plasmin, is commonly used. We have reviewed the current literature for this increasingly popular class of drugs to support clinical judgement in daily anaesthetic practice.

THE PAPWORTH PLUG - successful use of high dose fibrinogen concentrate and platelet concentrate in potential life-threatening complication after cardiopulmonary bypass surgery in a patient with Type 2M Vicenza von Willebrand Disease.

Anecdotally, fibrinogen concentrate (FC) has been used as a "universal" haemostatic agent in complex post-cardiopulmonary bypass (CPB) coagulopathy. We present a case where FC and two pools of platelets prevented life-threatening bleeding in a patient with moderate von Willebrand Disease (vWD) immediately post CPB.

Coagulopathy associated with massive cell salvage transfusion following aortic surgery.

Cell saver blood is used within the peri-operative setting of cardiothoracic surgery to reduce the need for transfusion of allogenic blood products. Several meta-analyses have proven a significant decrease in allogenic transfusion with the use of cell salvage techniques. Washing of red cells by the cell saver and subsequent transfusion of suspended red cells can occasionally cause coagulopathy, particularly when using high concentration heparin saline to wash the spilled blood. We present the case of a 74-year-old female who underwent complicated aortic surgery and was transfused large volumes of cell-saved blood due to post-operative bleeding, which subsequently led to coagulopathy.

The prevalence and association with transfusion, intensive care unit stay and mortality of pre-operative anaemia in a cohort of cardiac surgery patients.

Anaemia is increasingly prevalent in the United Kingdom. Despite recommendations to the contrary, many patients undergo cardiac surgery with undiagnosed and untreated anaemia. According to the World Health Organization definition, 1463/2688 (54.4%) patients undergoing cardiac surgery between 2008 and 2009 in our institution were anaemic. Compared with non-anaemic patients, anaemia was significantly associated with transfusion (791 (54.1%) vs 275 (22.4%), p < 0.001, OR (95% CI) 3.4 (2.8-4.1)), death (45 (3.1%) vs 13 (1.1%), p = 0.0005, OR 2.4 (1.2-4.5)), and prolonged ICU stay (287 (19.6%) vs 168 (13.7%) p < 0.001, OR 1.3 (1.0-1.6)). The prevalence of anaemia in this cohort is much greater than that previously reported. The cause of this excess is not clear. Pre-operative anaemia is a strong predictor of increased transfusion requirement, risk of ICU stay and death during cardiac surgery. The effect of increasing haemoglobin concentration therapeutically is not yet clear.

Near-patient platelet function testing in patients undergoing coronary artery surgery: a pilot study.

Platelet dysfunction after cardiopulmonary bypass contributes to microvascular bleeding and is associated with blood transfusion and resternotomy. Platelet count can be readily performed, but currently there are no standardised, reproducible, rapidly available platelet function tests. We studied platelet function as measured by multiple electrode platelet aggregometery (multiplate) and light transmission aggregometry in 44 patients undergoing routine coronary artery surgery. Platelet aggregation as measured by multiplate was reduced during and after cardiopulmonary bypass compared with baseline with evidence of partial recovery by the time of transfer to ITU. In patients transfused blood, platelet aggregation measured by multiplate was reduced during chest closure with adenosine diphosphate (18 U vs 29 U, p = 0.01) and thrombin receptor agonist peptide-6 agonist (65 U vs 88 U, p = 0.01) compared with patients not transfused. This suggests that multiplate, a new point of care analyser, can detect platelet dysfunction in this setting.

Comparative analysis of biofilm models to determine the efficacy of antimicrobials.

Biofilms are one of the greatest challenges in today's treatment of chronic wounds. While antimicrobials kill platonic bacteria within seconds, they are rarely able to harm biofilms. In order to identify effective substances for antibacterial therapy, cost-efficient, standardized and reproducible models that aim to mimic the clinical situation are required. In this study, two 3D biofilm models based on human plasma with immune cells (lhBIOM) or based on sheep blood (sbBIOM) containing S. aureus or P. aeruginosa, are compared with the human biofilm model hpBIOM regarding their microscopic structure (scanning electron microscopy; SEM) and their bacterial resistance to octenidine hydrochloride (OCT) and a sodium hypochlorite (NaOCl) wound-irrigation solution. The three analyzed biofilm models show little to no reaction to treatment with the hypochlorous solution while planktonic S. aureus and P. aeruginosa cells are reduced within minutes. After 48 h, octenidine hydrochloride manages to erode the biofilm matrix and significantly reduce the bacterial load. The determined effects are qualitatively reflected by SEM. Our results show that both ethically acceptable human and sheep blood based biofilm models can be used as a standard for in vitro testing of new antimicrobial substances. Due to their composition, both fulfill the criteria of a reality-reflecting model and therefore should be used in the approval for new antimicrobial agents.

Achieving large uniform tensile ductility in nanocrystalline metals.

Synchrotron x-ray diffraction and high-resolution electron microscopy revealed the origin of different strain hardening behaviors (and dissimilar tensile ductility) in nanocrystalline Ni and nanocrystalline Co. Planar defect accumulations and texture evolution were observed in Co but not in Ni, suggesting that interfacial defects are an effective passage to promote strain hardening in truly nanograins. Twinning becomes less significant in Co when grain sizes reduce to below ~15 nm. This study offers insights into achieving excellent mechanical properties in nanocrystalline materials.

Efficacy of antiseptics in a novel 3-dimensional human plasma biofilm model (hpBIOM).

The increasing incidence of non-healing wounds constitutes a pivotal socio-economic burden. 60-80% of chronic wounds are colonized by pathogenic microorganisms within a protective extracellular polymeric substance, bearing a great challenge in wound management. Human plasma was used to prepare the biofilm model (hpBIOM), adding pathogens to the plasma and forming Coagula-like discs with integrated pathogens were produced. The antiseptics Octenisept and Lavasorb were tested regarding their antibacterial properties on clinically relevant biofilm-growing bacteria (MRSA, P. aeruginosa) in the hpBIOM. Biofilm-typical glycocalyx-formation was confirmed using immunohistochemical staining. Treatment of a 12 h-maturated biofilm with Octenisept resulted in complete eradication of P. aeruginosa and MRSA after 48 h. Lavasorb proved less effective than Octenisept in this setting. In more mature biofilms (24 h), both antiseptics showed a delayed, partially decreased efficacy. Summarized, the hpBIOM provides essential factors for a translational research approach to be used for detailed human biofilm analyses and evaluation of antimicrobial/-biofilm properties of established and novel therapeutic strategies and products. Octenisept and Lavasorb showed an attenuated efficacy in the hpBIOM compared to planktonic conditions and previously published biofilm-studies, prompting the question for the necessity of introducing new international standards and pre-admission requirements on a translational base.

Modifying interleukin-2 concentrations during culture improves function of T cells for adoptive immunotherapy.

BACKGROUND: Adoptive immunotherapy with cytotoxic T cells has shown promising clinical results in patients with metastatic melanoma and post-transplant-associated viral infections. Cell transfer therapies often require the ex vivo expansion of large numbers of reactive lymphocytes. Therefore interleukin-2 (IL-2), a potent T-cell mitogenic cytokine that critically affects the features and effectiveness of T cells, is frequently added to cell culture media. METHODS: We examined the influence of various IL-2 concentrations on cell growth, cytotoxicity, cytokine release and surface marker expression of tumor-infiltrating lymphocytes (TIL) during a standard 14-day rapid expansion phase. The study was conducted under good manufacturing practice (GMP) conditions, using approved reagents in a class 10000 laboratory. RESULTS: T-cell cultures grown in very high IL-2 concentrations (600-6000 IU/mL) expanded massively and maximally secreted interferon (IFN)-gamma in response to antigenic stimulation, but exhibited only low direct cytotoxicity. On the other hand, TIL cultures grown in low concentrations of IL-2 throughout the rapid expansion phase expanded to a lower extent and barely secreted IFN-gamma but displayed high cytotoxic activity. A combined approach of starting with 10-120 IU/mL IL-2 during the first week, followed by increasing the IL-2 concentration to 6000 IU/mL during the second week, results in T cells that expand well, maximally produce IFN-gamma and are highly cytotoxic against tumor cells. DISCUSSION: Fine tuning of the IL-2 concentration during ex vivo expansion of T cells can yield high numbers of T cells with optimal features for clinical use.

Side effects of frequently used oral antidiabetics on wound healing in vitro.

Lifestyle diseases such as diabetes and arteriosclerosis are rising in the increasingly aging society, and the number of patients with daily intake of glucose-lowering medication has also increased. Interestingly, knowledge about oral antidiabetics with regard to wound healing is scarce. Therefore, the aim of this study was to identify possible (side) effects of the most frequently prescribed oral antidiabetics on skin cells and wound healing. Four oral antidiabetics of different substance classes (i.e., metformin, glibenclamide, sitagliptin, repaglinide) were investigated with regard to the promotion of cell metabolism and migration of human skin fibroblasts and keratinocytes by XTT and scratch assays. In addition, histological and immunohistochemical analyses were performed in a 3D wound model to address the impact of the antidiabetics on regeneration processes, such as cell migration, fibroblast activity, epidermal thickness, and cell apoptosis. In comparison to systemic application, metformin displayed the most adverse effects in vitro in nearly all analyses, interestingly at serum equivalent concentrations. In contrast, sitagliptin and glibenclamide had a slight but insignificant effect on fibroblasts compared with keratinocytes. Repaglinide tended to have a negative influence on keratinocyte metabolism. Interestingly, antidiabetics generally induced a significantly enhanced rate of apoptosis in fibroblasts, with the exception of repaglinide.Antidiabetics influenced key players in wound healing, namely, keratinocytes and fibroblasts. Particularly, metformin impaired human skin cells. These findings should be kept in mind in further studies because of their putative relevance in patients suffering from chronic wounds that do not respond to various wound therapies.