Melin, Matthew M

Objective: Diabetes mellitus affects over 25% of adults aged 65+ in the United States and is associated with a heightened risk of developing diabetic foot ulcers. Accumulation of senescent cells within the wound microenvironment can impair cutaneous repair, and senolytic therapies offer a promising approach to accelerate wound healing. Approach: In this study, topical fisetin, a flavonoid that promotes apoptosis of senescent cells, was evaluated for its impact on diabetic wound repair. Full-thickness excisional wounds were created on the dorsal skin of diabetic (db/db) mice. Animals were randomized to receive either topical vehicle ( n = 12) or fisetin ( n = 12) for three consecutive days per week, and wound healing outcomes were longitudinally assessed. Results: Topical fisetin significantly increased the ratio of healthy dermis to granulation by day 7 ( p = 0.04) and reduced dermal fibrosis by day 21 ( p = 0.03). Fisetin decreased p16+ cells ( p = 0.01) but increased p21+ cells ( p = 0.02) at day 7 in the dermis, indicating varied effects on senescent cells. M1 macrophages (CD80+) were decreased in the fisetin-treated group ( p = 0.05) at day 21, accompanied by a decrease in pro-inflammatory senescence-associated secretory phenotype cytokines, tumor necrosis factor alpha ( p = 0.03), and interleukin-1beta ( p = 0.01) at day 7. Innovation: Fisetin is the first topical seno-modulatory agent shown to enhance wound repair when administered after injury onset. Its favorable safety and efficacy in both modulating senescence and inflammation highlight its potential as a novel therapy for diabetic wounds. Conclusion: Topical fisetin enhances diabetic wound healing by reducing fibrosis and promoting healthy dermal regeneration through senescence and inflammation modulation. Saranya Wyles, MD, PhD

Space exploration exposes astronauts to unique conditions such as microgravity and space radiation, potentially influencing gene expression and triggering carcinogenesis. Paradoxically, these extreme environments could uncover other pro-treatment aspects of cancer biology. Despite numerous reviews addressing these aspects in isolation, a comprehensive synthesis of the effects of space stressors on cancer development is incomplete. This scoping review aims to provide a holistic perspective on the influence of spaceflight and associated stressors—including gravitation (hyper- and microgravity), radiation, and vibration—on the potential for cancer development and altered cellular mechanisms. We adhered to the PRISMA-ScR checklist for our review. A multitiered search strategy was employed in English, starting with a preliminary keyword identification in Google Scholar and PubMed. Subsequently, the main search was conducted across five databases—Cochrane, Embase, PubMed, Scopus, and Web of Science—until 22 February 2024. All included studies were thoroughly assessed by two independent reviewers. Of the 15,553 identified articles, 158 were deemed eligible. The majority (92%) were experimental studies, predominantly cell-based (74.17%). Breast (15.19%), thyroid (13.92%), and hematopoietic (11.40%) cancers were the most frequently examined. Spaceflight stressors could affect different biological systems variably, with microgravity impacting spatial growth and metastasis, and cosmic radiation exerting both tumor-suppressive and mutagenic effects. Our findings highlight the need for large-scale, prolonged analog studies mimicking space conditions to enhance mission safety and shed light on the nuanced effects of space stressors on cancer. Additionally, further extensive studies need to be performed in the true weightlessness of spaceflight, both animal-based and on human tissue (cell cultures and potentially whole perfusion organ models), in addition to crew pre/intra/post-flight long-duration evaluations. Furthermore, this unique research avenue may reveal cancer cell sensitivities to these stressors, opening new pathways for innovative therapeutic strategies in cancer treatment.

ABSTRACTVenous leg ulcers (VLUs) are traditionally managed with standard‐of‐care dressings, compression and appropriate adjunctive venous interventions for pathologic venous reflux. Due to pathophysiological complexity and underlying patient comorbidities, conducting randomised controlled trials to evaluate the comparative efficacy of advanced treatment modalities is difficult, as many patients would likely be excluded. This retrospective, pragmatic, real‐world evidence (RWE) study compared the healing outcomes of VLUs treated with either ovine forestomach matrix (OFM) (n = 312) or collagen/oxidised regenerated cellulose (ORC) (n = 239) in outpatient wound care centres. Unlike restrictive randomised controlled trials, minimal inclusion and exclusion criteria were applied to create two treatment cohorts that reflected the general VLU population. The incidence (%) of closure was greater in OFM‐treated VLUs at 12, 24 and 36 weeks, and this difference was significant at 24 and 36 weeks compared to collagen/ORC. Median time to wound closure was significantly faster (p = 0.045) in the OFM cohort (11.1 ± 0.6 weeks) compared to the collagen/ORC group (12.3 ± 1.0 weeks). Cox proportional hazards analysis demonstrated that OFM‐treated VLUs had a significantly greater probability of healing (up to ~40%). This RWE comparative efficacy study further substantiates the clinical benefit of OFM in the treatment of chronic wounds, such as VLU, in a real‐world patient cohort.

Abstract Managing pelvic osteomyelitis (POM) in the setting of stage IV pressure injuries requires multidisciplinary evaluation as well as patient and caregiver engagement and is complicated by the lack of high-evidence data to guide best practices. In this review, we describe our approach to pressure injury and POM evaluation and management through multidisciplinary collaboration and highlight areas of future research that are necessary to enhance patient outcomes, reduce healthcare costs, and improve the quality of life of those affected by POM.

Abstract Managing pelvic osteomyelitis (POM) in the setting of stage IV pressure injuries requires multidisciplinary evaluation as well as patient and caregiver engagement and is complicated by the lack of high-evidence data to guide best practices. In this review, we describe our approach to pressure injury and POM evaluation and management through multidisciplinary collaboration and highlight areas of future research that are necessary to enhance patient outcomes, reduce healthcare costs, and improve the quality of life of those affected by POM.

Abstract Under the influence of standard developmental physiology on the Earth’s surface (1 gravity equivalent known as “1G”), 70% of body fluids reside below the level of the heart.Fluid shifts towards the cephalic region during microgravity have also been speculated to contribute towards spaceflight associated neuro-ocular syndrome (SANS).Although a significant barrier to spaceflight, the underlying mechanism of SANS is not well understood, partially due to the spaceflight environment and limited medical capabilities including invasive diagnostic testing. Thus, non-invasive approaches to studying real-time fluid shifts in weightlessness could serve as critical areas of research to further SANS study and effective countermeasure protocol development. For continuous fluid shift monitoring and management, the goal is to establish baseline assessments utilizing real time point of care noninvasive imaging devices (NIID). NIID will first need to be quantified and validated through ground-based analogues, with subsequent acquisition of near continuous imaging from arrival in the weightlessness of LEO and during the time of adaptation, which may be variable among crew members. The purpose of this study was to examine temperature differential alterations, superficial venous flow patterns (head, neck, upper torso), and venous flow patterns along the lymphatic ventromedial bundles of the medial calves and thighs. Imaging was obtained in three different positions using three standards of care medical NIIDs: SnapShotTM by Kent Imaging, Scout by WoundVisionTM and LymphScannerTM by Delfin. 30 volunteers were assessed for temperature and lymphatic/venous flow using three different non-invasive devices that can measure temperature, perfusion, and image the lymphatic and venous structures. The volunteers were assessed in the sitting, supine, and 6-degree head down tilt (HDT) positions, with pre/post assessments for the HDT position. Venous and lymphatic flow patterns may vary upon position changes (sitting vs. supine vs. 6-degree head down tilt), and in response to MLD performance in the treatment group. Fifteen subjects per group (N = 30) completed all visits and were used in the full analysis. The sitting and supine position data did not show statistical significance at any of the time points and with the devices used. The HDT data from SnapShot (looking at perfusion, deoxy and oxyhemoglobin) and Wound Vision Scout (thermal imaging) did not show statistical significance between the control and treatment groups at any time points. No significant difference for any of the within-group comparisons were found with the Lymphscanner. A significant reduction in left temple TDC for the treatment group was found at post-30-minutes (5.77, 95% CI: 1.24, 10.30) and post-180-minutes. A significant reduction in right subclavicular TDC for the treatment group was found at post-180-Minutes (5.09, 95% CI: 0.16, 10.03). A significant increase in the left ventromedial bundle for the treatment group was found at post-90-Minutes (5.72, 95% CI: 0.34, 11.10) and post-120-Minutes (5.85, 95% CI: 0.47, 11.23). A significant increase in the right ventromedial bundle for the treatment group was found at post-90 minutes (5.53, 95% CI: 0.21, 10.84). This is the first HDT spaceflight analogue study, to our knowledge, in which dermal fluid shifts were evaluated using point-of-care noninvasive imaging modalities including Near Infrared Spectroscopy (NIRS), thermography and a subcutaneous edema monitor, with subsequent application of manual lymphatic drainage (MLD) techniques to stimulate dermal lymphatic function as a countermeasure and mitigation therapeutic for intervention in cephalad fluid shifts. Further validating studies are indicated for NIIDs to further quantify fluid shifts in both analogues and weightlessness.

Medical and surgical emergencies occasionally present as ruptured abdominal aortic aneurysms (RAAA). To assess benefits of laparotomies and adverse effects of unnecessary operations, the authors reviewed their experience. Thirteen patients, 9 women, 4 men (mean age: 72 years, range: 41-85) underwent emergency laparotomy between 1988 and 1996 for presumed RAAA and were found to have other surgical or medical emergencies. All the patients presented with hypotension, 12 had abdominal or back pain, four had pulsatile abdominal mass. Rupture was not excluded by computed tomography scan in three or by ultrasonography in two patients. Laparotomy disclosed intact abdominal aorta in all, but seven patients had abdominal aortic aneurysm. Of five surgical emergencies, laparotomy was indicated in four: three for ruptured visceral artery aneurysms, one for perforated duodenal ulcer. The fifth patient required thoracotomy for ruptured thoracic aneurysm. Four of eight medical emergencies were myocardial infarctions. One iatro genic complication required reoperation for bleeding. Mean hospital stay was 18 days; mean hospital charges were $40,771. Seven (54%) early deaths occurred; none were caused directly by the operation. Laparotomy was indicated in one third of deceptive emergencies that present as RAAA. Although mortality, morbidity, and costs were high, iatrogenic surgical complica tions were rare and deaths were not caused by unnecessary operations.

Abstract Percutaneous cholecystostomy offers a potentially important therapeutic modality for critically ill patients with acute cholecystitis who represent a high risk for general anaesthesia. The aim of the study was to assess experience with percutaneous cholecystostomy in resolving the acute episode of cholecystitis without operative intervention. Twenty-two consecutive patients with a clinical diagnosis of acute cholecystitis underwent the procedure. All were at high risk for general anaesthesia, and all but one developed cholecystitis while hospitalized for another co-morbid condition; 14 were in an intensive care unit. Twenty-one of the 22 patients proved to have acute cholecystitis (11 acalculous, ten cholelithiasis). There were no acute technical complications. Toxaemia resolved in 17 of the 21 patients with acute cholecystitis. Acute cholecystitis failed to resolve in three patients; all died within 48 h from overwhelming generalized sepsis. One patient required emergency cholecystectomy for bile peritonitis when the cholecystostomy catheter became dislodged 24 h after placement. The 60-day mortality rate for the acalculous and calculous patient groups was 55 and 20 per cent, respectively. Only three interval cholecystectomies have been performed at a mean follow-up of 19 months. In conclusion, percutaneous cholecystostomy may be the procedure of choice for the management of acute cholecystitis in the very high-risk critically ill patient. If symptoms fail to resolve quickly, ongoing sepsis, cholangitis or gallbladder necrosis should be suspected.