Microjet wound therapy versus sharp debridement on wound size reduction: a pilot randomised controlled trial.

OBJECTIVE: There are several methods of treating hard-to-heal (chronic) wounds, each differing in terms of efficiency, selectivity, speed, cost and pain. The objective is to activate a wound to initiate the healing cascade. For this pilot study we assessed the feasibility of a new microjet wound therapy technology compared to standard sharp debridement in wound outcomes. METHOD: A randomised, controlled, open-label pilot study was conducted in one outpatient wound clinic in Western Switzerland from March 2022 to May 2023. RESULTS: A total of 13 consecutive patients were randomly assigned to receive either microjet wound therapy (n=5) or standard mechanical debridement with instruments (n=8). As a feasibility study, there was insufficient power to detect significant differences between the groups. However, in the intervention group, our analysis may indicate a modestly faster reduction in wound area. Microjet wound therapy appears to alleviate patient anxiety and offer cost savings due to the potential for reduced time, as well as the number of required treatments. This meant fewer overall consultations. CONCLUSION: This study highlights a trend that may indicate that microjet therapy holds value in promoting faster healing of hard-to-heal wounds, and it provides a feasibility basis for a sufficiently powered multicentre trial.

Prevalence and incidence of venous leg ulcers-A systematic review and meta-analysis.

Venous leg ulcers (VLU) represent a major public health challenge. Little is known about the prevalence and incidence of VLU internationally. Published studies are usually reporting different estimates because of disparities in study designs and measurement methods. Therefore, we conducted a systematic literature review and meta-analysis to identify the prevalence and incidence of VLU internationally and to characterise the population as reported in these studies. Studies were identified from searches in Medline (PubMed), CINAHL Complete (EBSCOhost), Embase, Scopus, Web of Science, LiSSa (Littérature Scientifique en Santé), Google Scholar and Cochrane Database of Systematic Reviews up to November 2022. Studies were included if their primary outcomes were reported as a period prevalence or point prevalence or cumulative incidence or incidence VLU rate. Fourteen studies met the inclusion criteria, 10 reporting estimates of prevalence, three reporting both prevalence and incidence estimates and one incidence. All were included in meta-analyses. The results show a pooled prevalence of 0.32% and a pooled incidence of 0.17%. Our results highlighted an extreme heterogeneity across effect sizes for both prevalence and incidence, which prevent a meaningful interpretation of pooled indexes and argue for further studies with specific prevalence-type reported and target population under study.

Superabsorbent charcoal dressing versus silver foam dressing in wound area reduction: a randomised controlled trial.

AIM: This study aimed to compare the effect of a novel sterile polyacrylate wound pad with activated carbon cloth treatment with a standard non-adhesive hydrocellular foam dressing with silver in reducing wound area. METHOD: A multicentre randomised controlled open-label wound-dressing trial was conducted in two wound care outpatient clinics in western Switzerland from November 2018 to March 2020. RESULTS: A total of 77 successive patients were randomised to receive either a sterile polyacrylate wound pad with activated carbon cloth treatment (n=38) or the standard non-adhesive hydrocellular foam dressing with silver (n=39). Reduction in wound area was the primary outcome, whereas the application period of the dressing, odour, maceration and pain were the secondary outcomes. Wound area was measured at baseline and during each wound dressing change until the dressings were no longer indicated. Wound area reduced faster in the intervention group than in the control group (0.45cm2 per day vs. 0.2cm2 per day), although the application period was longer in the intervention group compared with the control group (9.5 days vs. 8.1 days). Maceration reduction was more pronounced in the intervention group (-2.07cm2) than in the control group (-0.71cm2). Odour, pain and infection were similar in both groups. CONCLUSION: Sterile polyacrylate wound pad dressings with activated carbon cloth reduced the wound area, as well as the maceration area, faster than the non-adhesive hydrocellular foam dressing with silver.

Ether lipids, sphingolipids and toxic 1-deoxyceramides as hallmarks for lean and obese type 2 diabetic patients.

AIM: The worldwide increase in obesity and type 2 diabetes (T2D) represents a major health challenge. Chronically altered lipids induced by obesity further promote the development of T2D, and the accumulation of toxic lipid metabolites in serum and peripheral organs may contribute to the diabetic phenotype. METHODS: To better understand the complex metabolic pattern of lean and obese T2D and non-T2D individuals, we analysed the lipid profile of human serum, skeletal muscle and visceral adipose tissue of two cohorts by systematic mass spectrometry-based lipid analysis. RESULTS: Lipid homeostasis was strongly altered in a disease- and tissue-specific manner, allowing us to define T2D signatures associated with obesity from those that were obesity independent. Lipid changes encompassed lyso-, diacyl- and ether-phospholipids. Moreover, strong changes in sphingolipids included cytotoxic 1-deoxyceramide accumulation in a disease-specific manner in serum and visceral adipose tissue. The high amounts of non-canonical 1-deoxyceramide present in human adipose tissue most likely come from cell-autonomous synthesis because 1-deoxyceramide production increased upon differentiation to adipocytes in mouse cell culture experiments. CONCLUSION: Taken together, the observed lipidome changes in obesity and T2D will facilitate the identification of T2D patient subgroups and represent an important step towards personalized medicine in diabetes.

Development and feasibility of a multidisciplinary education program on adherence to treatment in persons with venous leg ulcers in the clinical setting: A pilot study.

AIMS: The aim of this study is to: (a) develop an evidence-based multidisciplinary educational intervention for patients with a venous leg ulcer; and (b) conduct a pilot study to assess the feasibility of the intervention in the clinical setting. DESIGN: A two-stage study design was used: (a) an multidisciplinary expert committee designed an educational intervention including support materials; and (b) a pilot randomized controlled trial was conducted to assess the feasibility of the intervention in one wound care outpatient clinic in Western Switzerland. METHODS: A multidisciplinary expert committee identified evidence for effective care interventions to improve venous leg ulcer patients' wound healing and recurrences rates. They subsequently designed the educational intervention and support materials. In this pilot study venous leg ulcer patients were then randomly assigned to receive multidisciplinary education or standard care from March-July 2018. The objective was to evaluate the feasibility of the intervention in the clinical setting. Allocation to groups was achieved to concealed, simple randomization. Participants and study nurses were not blinded, data analyst was blinded. RESULTS: The intervention, including support material was developed. Twelve of 16 invited venous leg ulcer patients were recruited and randomized (control group N = 6; intervention group N = 6). Participation rate was 75%. The implementation of the intervention was feasible in the clinical setting. The performance of the Venous Leg Ulcer Self Efficacy Tool for measuring adherence to therapy and the Mini Nutritional Assessment and Frequent Food Questionnaire for the assessment of the nutritional intake was satisfactory. However, Fitbit smartwatch for measuring activity was not a suitable device in this study population. CONCLUSION: The implementation of the designed multidisciplinary educational program was feasible. The pilot study identified weaknesses in the study protocol, which will be amended for the full-size clinical trial. IMPACT: Findings of the pilot study informed the improvement of the design of the main study.

Comparison of sterile polyacrylate wound dressing with activated carbon cloth and a standard non-adhesive hydrocellular foam dressing with silver: a randomised controlled trial protocol.

OBJECTIVE: Hard-to-heal wounds such as leg (LU) or diabetic foot ulcers (DFU) are slow healing, have a high recurrence rate and are associated with infection, smell and exudate. Current therapeutic approaches are multifaceted and focus on improving wound healing and preventing recurrences. Advanced wound dressings, especially super absorbent dressings are an important aspect of wound care, as hard-to-heal wounds tend to produce excessive amounts of exudate, which may contribute to maceration and excoriation, thus delaying wound healing. Additionally, excessive wound exudate is associated with malodour. Therefore, an important aspect of care is the management of exudate and odour. The use of effective advanced wound dressings is a promising strategy to achieve adequate absorption of wound exudate and malodour promoting wound healing. The aim of the current study is to determine whether there is a difference in wound size reduction between wounds dressed with either a sterile polyacrylate wound dressing with activated carbon cloth or a hydrocellular foam dressing with silver. METHOD: A randomised controlled trial with 248 participants in one wound care outpatient clinic is proposed. Randomisation will be concealed. The outcome assessor will be blinded to the group allocation of participants. CONCLUSION: This research project compares two wound dressings in an everyday care setting. Since the cost of hard-to-heal wounds to individuals, the economy and society is high, an evaluation of which wound dressing leads to a faster reduction of wound size and subsequent wound healing is an important issue/question for the individuals affected, their families, society and the health-care system.

MicroRNAs modulate core-clock gene expression in pancreatic islets during early postnatal life in rats.

AIMS/HYPOTHESIS: Evidence continues to emerge detailing a fine-tuning of the regulation of metabolic processes and energy homeostasis by cell-autonomous circadian clocks. Pancreatic beta cell functional maturation occurs after birth and implies transcriptional changes triggered by a shift in the nutritional supply that occurs at weaning, enabling the adaptation of insulin secretion. So far, the developmental timing and exact mechanisms involved in the initiation of the circadian clock in the growing pancreatic islets have never been addressed. METHODS: Circadian gene expression was measured by quantitative RT-PCR in islets of rats at different postnatal ages up to 3 months, and by in vitro bioluminescence recording in newborn (10-day-old) and adult (3-month-old) islets. The effect of the microRNAs miR-17-5p and miR-29b-3p on the expression of target circadian genes was assessed in newborn rat islets transfected with microRNA antisense or mimic oligonucleotides, and luciferase reporter assays were performed on the rat insulin-secreting cell line INS832/13 to determine a direct effect. The global regulatory network between microRNAs and circadian genes was computationally predicted. RESULTS: We found up to a sixfold-change in the 24 h transcriptional oscillations and overall expression of Clock, Npas2, Bmal1, Bmal2, Rev-erbα, Per1, Per2, Per3 and Cry2 between newborn and adult rat islets. Synchronisation of the clock machinery in cultured islet cells revealed a delayed cell-autonomous rhythmicity of about 1.5 h in newborn compared with adult rats. Computational predictions unveiled the existence of a complex regulatory network linking over 40 microRNAs displaying modifications in their expression profiles during postnatal beta cell maturation and key core-clock genes. In agreement with these computational predictions, we demonstrated that miR-17-5p and miR-29b-3p directly regulated circadian gene expression in the maturing islet cells of 10-day-old rats. CONCLUSIONS/INTERPRETATION: These data show that the circadian clock is not fully operational in newborn islets and that microRNAs potently contribute to its regulation during postnatal beta cell maturation. Defects in this process may have long-term consequences on circadian physiology and pancreatic islet function, favouring the manifestation of metabolic diseases such as diabetes.

Pancreatic α- and ß-cellular clocks have distinct molecular properties and impact on islet hormone secretion and gene expression.

A critical role of circadian oscillators in orchestrating insulin secretion and islet gene transcription has been demonstrated recently. However, these studies focused on whole islets and did not explore the interplay between α-cell and ß-cell clocks. We performed a parallel analysis of the molecular properties of α-cell and ß-cell oscillators using a mouse model expressing three reporter genes: one labeling α cells, one specific for ß cells, and a third monitoring circadian gene expression. Thus, phase entrainment properties, gene expression, and functional outputs of the α-cell and ß-cell clockworks could be assessed in vivo and in vitro at the population and single-cell level. These experiments showed that α-cellular and ß-cellular clocks are oscillating with distinct phases in vivo and in vitro. Diurnal transcriptome analysis in separated α and ß cells revealed that a high number of genes with key roles in islet physiology, including regulators of glucose sensing and hormone secretion, are differentially expressed in these cell types. Moreover, temporal insulin and glucagon secretion exhibited distinct oscillatory profiles both in vivo and in vitro. Altogether, our data indicate that differential entrainment characteristics of circadian α-cell and ß-cell clocks are an important feature in the temporal coordination of endocrine function and gene expression.

Parallel Measurement of Circadian Clock Gene Expression and Hormone Secretion in Human Primary Cell Cultures.

Circadian clocks are functional in all light-sensitive organisms, allowing for an adaptation to the external world by anticipating daily environmental changes. Considerable progress in our understanding of the tight connection between the circadian clock and most aspects of physiology has been made in the field over the last decade. However, unraveling the molecular basis that underlies the function of the circadian oscillator in humans stays of highest technical challenge. Here, we provide a detailed description of an experimental approach for long-term (2-5 days) bioluminescence recording and outflow medium collection in cultured human primary cells. For this purpose, we have transduced primary cells with a lentiviral luciferase reporter that is under control of a core clock gene promoter, which allows for the parallel assessment of hormone secretion and circadian bioluminescence. Furthermore, we describe the conditions for disrupting the circadian clock in primary human cells by transfecting siRNA targeting CLOCK. Our results on the circadian regulation of insulin secretion by human pancreatic islets, and myokine secretion by human skeletal muscle cells, are presented here to illustrate the application of this methodology. These settings can be used to study the molecular makeup of human peripheral clocks and to analyze their functional impact on primary cells under physiological or pathophysiological conditions.

Clock-Talk: Interactions between Central and Peripheral Circadian Oscillators in Mammals.

In mammals, including humans, nearly all physiological processes are subject to daily oscillations that are governed by a circadian timing system with a complex hierarchical structure. The central pacemaker, residing in the suprachiasmatic nucleus (SCN) of the ventral hypothalamus, is synchronized daily by photic cues transmitted from the retina to SCN neurons via the retinohypothalamic tract. In turn, the SCN must establish phase coherence between self-sustained and cell-autonomous oscillators present in most peripheral cell types. The synchronization signals (Zeitgebers) can be controlled more or less directly by the SCN. In mice and rats, feeding-fasting rhythms, which are driven by the SCN through rest-activity cycles, are the most potent Zeitgebers for the circadian oscillators of peripheral organs. Signaling through the glucocorticoid receptor and the serum response factor also participate in the phase entrainment of peripheral clocks, and these two pathways are controlled by the SCN independently of feeding-fasting rhythms. Body temperature rhythms, governed by the SCN directly and indirectly through rest-activity cycles, are perhaps the most surprising cues for peripheral oscillators. Although the molecular makeup of circadian oscillators is nearly identical in all cells, these oscillators are used for different purposes in the SCN and in peripheral organs.

Human peripheral clocks: applications for studying circadian phenotypes in physiology and pathophysiology.

Most light-sensitive organisms on earth have acquired an internal system of circadian clocks allowing the anticipation of light or darkness. In humans, the circadian system governs nearly all aspects of physiology and behavior. Circadian phenotypes, including chronotype, vary dramatically among individuals and over individual lifespan. Recent studies have revealed that the characteristics of human skin fibroblast clocks correlate with donor chronotype. Given the complexity of circadian phenotype assessment in humans, the opportunity to study oscillator properties by using cultured primary cells has the potential to uncover molecular details difficult to assess directly in humans. Since altered properties of the circadian oscillator have been associated with many diseases including metabolic disorders and cancer, clock characteristics assessed in additional primary cell types using similar technologies might represent an important tool for exploring the connection between chronotype and disease, and for diagnostic purposes. Here, we review implications of this approach for gathering insights into human circadian rhythms and their function in health and disease.

An evaluation of surface micro- and mesoplastic pollution in pelagic ecosystems of the Western Mediterranean Sea.

This study examines the distribution, abundance and characteristics of surface micro- and mesoplastic debris in the Western Mediterranean Sea. 41 samples were collected in 2011 (summer) and 2012 (summer). Results, firstly, revealed that micro- (<5 mm) and mesoplastic debris were widely and uniformly distributed in this area with average concentrations of 130,000 parts/km(2) and 5700 parts/km(2), respectively. Importantly, a strong correlation between micro- and mesoplastic concentrations was identified. Secondly, a classification based on the shape and appearance of microplastics indicated the predominant presence of fragments (73%) followed by thin films (14%). Thirdly, the average mass ratio of microplastic to dry organic matter has been measured at 0.5, revealing a significant presence of microplastics in comparison to plankton. Finally, a correction method was applied in order to correct wind mixing effect on microplastics' vertical distribution. This data allows for a comprehensive view, for the first time, of the spatial distribution and nature of plastic debris in the Western Mediterranean Sea.

Real-time recording of circadian liver gene expression in freely moving mice reveals the phase-setting behavior of hepatocyte clocks.

The mammalian circadian timing system consists of a master pacemaker in the suprachiasmatic nucleus (SCN) in the hypothalamus, which is thought to set the phase of slave oscillators in virtually all body cells. However, due to the lack of appropriate in vivo recording technologies, it has been difficult to study how the SCN synchronizes oscillators in peripheral tissues. Here we describe the real-time recording of bioluminescence emitted by hepatocytes expressing circadian luciferase reporter genes in freely moving mice. The technology employs a device dubbed RT-Biolumicorder, which consists of a cylindrical cage with reflecting conical walls that channel photons toward a photomultiplier tube. The monitoring of circadian liver gene expression revealed that hepatocyte oscillators of SCN-lesioned mice synchronized more rapidly to feeding cycles than hepatocyte clocks of intact mice. Hence, the SCN uses signaling pathways that counteract those of feeding rhythms when their phase is in conflict with its own phase.

Simulated body temperature rhythms reveal the phase-shifting behavior and plasticity of mammalian circadian oscillators.

The circadian pacemaker in the suprachiasmatic nuclei (SCN) of the hypothalamus maintains phase coherence in peripheral cells through metabolic, neuronal, and humoral signaling pathways. Here, we investigated the role of daily body temperature fluctuations as possible systemic cues in the resetting of peripheral oscillators. Using precise temperature devices in conjunction with real-time monitoring of the bioluminescence produced by circadian luciferase reporter genes, we showed that simulated body temperature cycles of mice and even humans, with daily temperature differences of only 3°C and 1°C, respectively, could gradually synchronize circadian gene expression in cultured fibroblasts. The time required for establishing the new steady-state phase depended on the reporter gene, but after a few days, the expression of each gene oscillated with a precise phase relative to that of the temperature cycles. Smooth temperature oscillations with a very small amplitude could synchronize fibroblast clocks over a wide temperature range, and such temperature rhythms were also capable of entraining gene expression cycles to periods significantly longer or shorter than 24 h. As revealed by genetic loss-of-function experiments, heat-shock factor 1 (HSF1), but not HSF2, was required for the efficient synchronization of fibroblast oscillators to simulated body temperature cycles.

Differential display of DNA-binding proteins reveals heat-shock factor 1 as a circadian transcription factor.

The circadian clock enables the anticipation of daily recurring environmental changes by presetting an organism's physiology and behavior. Driven and synchronized by a central pacemaker in the brain, circadian output genes fine-tune a wide variety of physiological parameters in peripheral organs. However, only a subset of circadianly transcribed genes seems to be directly regulated by core clock proteins. Assuming that yet unidentified transcription factors may exist in the circadian transcriptional network, we set out to develop a novel technique, differential display of DNA-binding proteins (DDDP), which we used to screen mouse liver nuclear extracts. In addition to several established circadian transcription factors, we found DNA binding of heat-shock factor 1 (HSF1) to be highly rhythmic. HSF1 drives the expression of heat-shock proteins at the onset of the dark phase, when the animals start to be behaviorally active. Furthermore, Hsf1-deficient mice have a longer free-running period than wild-type littermates, suggesting a combined role for HSF1 in the mammalian timekeeping and cytoprotection systems. Our results also suggest that the new screening method DDDP is not limited to the identification of circadian transcription factors but can be applied to discover novel transcriptional regulators in various biological systems.

Circadian gene expression in individual fibroblasts: cell-autonomous and self-sustained oscillators pass time to daughter cells.

The mammalian circadian timing system is composed of a central pacemaker in the suprachiasmatic nucleus (SCN) of the brain and subsidiary oscillators in most peripheral cell types. While oscillators in SCN neurons are known to function in a self-sustained fashion, peripheral oscillators have been thought to damp rapidly when disconnected from the control exerted by the SCN. Using two reporter systems, we monitored circadian gene expression in NIH3T3 mouse fibroblasts in real time and in individual cells. In conjunction with mathematical modeling and cell co-culture experiments, these data demonstrated that in vitro cultured fibroblasts harbor self-sustained and cell-autonomous circadian clocks similar to those operative in SCN neurons. Circadian gene expression in fibroblasts continues during cell division, and our experiments unveiled unexpected interactions between the circadian clock and the cell division clock. Specifically, the circadian oscillator gates cytokinesis to defined time windows, and mitosis elicits phase shifts in circadian cycles.