Necrosis Research Articles

Evidence-Informed Nursing Clinical Practices for Wound Debridement

ABSTRACT Debridement, a mainstay of nursing clinical practice, refers to the removal of dead or unhealthy tissue from a wound to facilitate healing. Debridement is one component of the concept of wound bed preparation that has long guided the approach to wound management. The ability of a wound to heal must be determined prior to the initiation of any method of debridement. In areas where high-quality, comparative studies on the relative benefits of different debridement modalities are lacking, nurses should adopt an evidence-informed approach to care. To do this, nurses must understand the importance of following a comprehensive, holistic approach when treating chronic wounds. Nurses should have knowledge of inflammation and infection control and of the fundamentals of moisture management, recognize the need for debridement in healable wounds, and be familiar with different debridement options. This article provides nurses with a wound management framework, an overview of wound debridement options based on the potential for wound healing, and scope of practice considerations for developing a plan of care. A composite case is presented to illustrate the critical considerations in wound care.

Diabetic Foot Infection: Understanding the Disease its Diagnosis and Prevention

The purpose of this manuscript is to provide a thorough overview of current concepts regarding the evaluation and management of diabetic foot infections. One of the most serious and frequent complications that patients with diabetes mellitus come across is diabetic foot infections. A comprehensive investigation of the literature on diabetic foot infections has been conducted, with a focus on the Diabetes mellitus, pathophysiology, identifiable risk factors, evaluation (including physical examination and laboratory values), treatment approaches, and determining the infection's severity. Preventing severe limb loss and maintaining function are the goals of treating diabetic foot infections. Most diabetic foot infections are caused by polymicrobial organisms. It is probable that a variety of gram-positive and gram-negative aerobes are present at the infection site. Controlling the infection and avoiding more morbidity requires early lesion detection, timely initiation of the proper antibiotic therapy, and surgical excision of necrotic tissue and bone.

Synergistic effect of curcumin and Piperine loaded Niosomal nanoparticles on acute pulmonary toxicity induced by Paraquat in mice.

Paraquat (PQ), a widely used non-selective herbicide, induces severe lung toxicity by promoting cell death and tissue necrosis through the generation of reactive oxygen species (ROS) and free radicals. This study aimed to develop and evaluate novel niosomal nanoparticles (NPs) encapsulating curcumin and piperine to mitigate PQ-induced acute pulmonary toxicity in Balb/c mice. The NPs were prepared using non-ionic surfactants and cholesterol via the thin film hydration method. Characterization revealed high encapsulation efficiency (>85%), proper particle sizes (264-286nm), narrow polydispersity index (PDI) (0.19±0.04 to 0.23±0.02), and good stability over 90days. Thermal analysis confirmed successful encapsulation of curcumin and piperine within the niosomal NPs. In vivo studies showed that PQ exposure significantly elevated ROS, lipid peroxidation (LPO), and protein carbonylation (PC) levels, while reducing glutathione (GSH) levels and impairing mitochondrial function (P<0.001). However, co-treatment with curcumin- and piperine-loaded niosomal NPs effectively reversed these effects (P<0.001), improving mitochondrial function. The combined formulation of curcumin and piperine in niosomal NPs offers a promising therapeutic strategy for treating PQ-induced pulmonary toxicity, likely due to enhanced bioavailability and potent antioxidant activity.

Repair of Radiation Ulcers After Breast Cancer Surgery With Simple Local Random Flaps

Background Radiation ulcers that develop after breast cancer surgery are mainly repaired with pedicled flaps or free flaps rather than local random flaps or skin grafts due to large skin defects and poor wound healing. Complicated surgical techniques and donor site reconstruction increase the risk of failure. We report our experience of using the local random long neck reading man flap (LNRMF) to cover large chest wall radiation ulcers, achieving good outcomes. Methods Eight patients who developed chest radiation ulcers after breast cancer surgery and were treated between January 2024 and June 2024 were included. The duration of the wounds ranged from 8 to 35 days. Necrotic and ischemic tissues were completely surgically removed, and subsequent wounds were repaired with LNRMFs. The wounds ranged from 6 cm × 8 cm to 15 cm × 16 cm in size. Visual analog scale scores were recorded during therapy. Results Eight patients healed well after the first stage. The sutures were removed 10–17 days (average, 12.63 days) after surgery, and no infections, necrosis, or necrotic skin flaps were observed. The average Visual analog scale score was 2.5. The follow-up period was 2–6 months (mean, 4.7 months). Slight linear scarring was observed, and no limitations in shoulder elevation were observed in seven patients; however, 1 patient had slightly limited shoulder elevation. The average SCAR scale score was 3.88, and all sensation scores (according to the Medical Research Council scale) were S3+. Conclusions LNRMFs are easily created and effectively repair secondary wounds that develop after the resection of radiation ulcers that develop after breast cancer surgery and large skin defects. These flaps can be widely used and should be promoted at the grassroots level.

A standard area diagram for Fusarium yellows rating in sugar beet (Beta vulgaris)

AbstractMembers of the Fusarium oxysporum species complex are pathogens of sugar beet causing Fusarium yellows. Fusarium yellows can reduce plant stand, yield and extractable sugar. Improving host plant resistance against Fusarium‐induced diseases, like Fusarium yellows, represents an important long‐term breeding target in sugar beet breeding programmes. Current methods for rating Fusarium yellows disease severity rely on an ordinal scale, which limits precision for intermediate phenotypes. In this study, we aimed to improve the accuracy and precision of rating Fusarium yellows by developing a standard area diagram (SAD). Two SAD versions were created using images of sugar beets infected with Fusarium oxysporum strain F19. Each version was tested using inexperienced raters. Version 1 and the improved version 2 SAD showed no statistical differences in Lin's concordance correlation coefficient (LCC) values, which was used to assess accuracy and precision between the two versions (Cb = 0.99 for both versions, c = 0.97 and 0.96 for version 1 and 2, respectively). In addition, five naïve Bayesian machine‐learning models that used pixel classification to determine disease score were tested for congruency to human estimates in SAD version 2. Root mean square error was lowest compared to the ‘true’ values for the unweighted model and a model where necrotic tissue was given a 2× weight (12.4 and 12.6, respectively). The creation of this SAD enables breeding programmes to make consistent, accurate disease ratings regardless of personnel's previous experience with Fusarium yellows. Additionally, more iterations of pixel quantification equations may overcome accuracy issues for rating Fusarium yellows.

Mycotic Necrotizing Fasciitis of the Face: A Case Report and Review of Literature

Necrotizing fasciitis is a rare but potentially serious and fatal infection. It is a dermo-hypodermitis with necrosis of the superficial fascia, typically caused by Streptococcus pyogenes. However, rare cases of fungal necrotizing fasciitis have been reported. We report the case of a 65-year-old type II diabetic patient who developed necrotizing cellulitis of the right hemiface with homolateral orbito-palpebral extension. The initial management was based on drainage of purulent collections with resection of necrotic tissues associated with parenteral antibiotherapy without clinical improvement. Bacteriological sampling revealed the presence of yeast. The mycological examination was positive for Candida albicans resistant to fluconazole. Antifungal treatment with intravenous amphotericin B was initiated with good clinical progression and complete remission after 1 month. The aim of this paper is to highlight the importance of promptly considering this diagnosis and extending the initial assessment of necrotic skin lesions to include mycological examination to detect severe forms of cutaneous candidiasis.

Immune Suppression and Rapid Invasion of Nile Tilapia Gills Following an Acute Challenge by Flavobacterium davisii

Flavobacterium davisii is one of the causative agents of columnaris disease, significantly impacting Nile tilapia aquaculture. This study examines the invasion and immune evasion mechanisms of a highly virulent F. davisii strain through transcriptomic profiling of tilapia gills following acute immersion. We identified 8192 differentially expressed genes (DEGs) at 2 h, 6 h, and 12 h post-infection. They are enriched in pathways related to oxidative stress, immune suppression, tissue necrosis, and bacterial infection. Notably, early overexpression of rhamnose-binding lectin and mucin genes facilitated bacterial adhesion. Key immune genes, including those encoding major histocompatibility complex (MHC), immunoglobulins (Ig), Toll-like receptors (TLRs), and chemokines, were downregulated, indicating immune suppression. Conversely, immune evasion genes such as Fc receptor-like (FcRL) and programmed death-ligand 1 (PDL1) were upregulated, along with genes associated with reactive oxygen species (ROS) production, leading to increased tissue damage. Additionally, the upregulation of fibroblast growth factor and collagen genes suggested active tissue repair. In conclusion, F. davisii rapidly invades its host by enhancing adhesion to gill tissues, suppressing immune function, and inducing tissue damage. These findings enhance our understanding of F. davisii infection mechanisms and support the future breeding of disease-resistant tilapia and the development of sustainable control strategies.

Efficacy of Cytoreg in the treatment of diabetic foot disease.

Complications from diabetic foot wounds, including bacterial infection, ulceration and gangrene, are major causes of hospitalisation and are responsible for 85% of amputations in patients with diabetes. Given that orally administered investigational therapeutic Cytoreg (Cytorex de Venezuela SA, Venezuela), a defined aqueous mixture of hydrofluoric, hydrochloric, sulfuric, phosphoric, citric and oxalic acids, has been shown to increase levels of arterial blood oxygen in a Wistar rat model, oral and oral+topical Cytoreg were tested on patients with diabetic foot ulcers (DFUs) under a humanitarian, compassionate-use protocol. All patients received oral Cytoreg (5.0 ml concentrate in fruit juice) for 30 days; half also received weekly wound washing with Cytoreg concentrate in isotonic saline (1:50 volume/volume) (oral+topical group). In addition to standard clinical observations, wounds were monitored against the Saint Elian checklist system for the diabetic foot. A total of 10 patients took part in the study. Complete wound closure was observed in 4/5 patients in the oral+topical group; in the remaining patient, necrotic and fibrin tissues on the wound edges were eliminated. Half (2/4) of the patients receiving oral-only Cytoreg experienced complete wound closure; one patient in this group was removed prematurely because of an unrelated illness and was not replaced. During the study, no significant differences were observed between groups in either the oxygen saturation of the affected tissues or in insulin and glycaemia levels (p<0.05). Significant increases in arterial haemoglobin and arterial oxygen partial pressure (p<0.05) were observed, and significant decreases were measured in the levels of glycosylated haemoglobin, aspartate aminotransferase, glutamic-pyruvic transaminase, creatine and urea (p<0.05). The results of this study justify an expanded clinical study for the treatment of DFUs with Cytoreg.

Compartment syndrome following self-injection of hydrocarbon: a case series

BackgroundHydrocarbon products are generally used by drug addict patients in attempt to emulate drug effects or as a means of self-harm. These substances can be assumed through inhalation or by intravenous or intramuscular injection. When hydrocarbons are injected intramuscularly into the limbs, they can cause the compartment syndrome, necessitating surgical intervention. Cases seriesWe describe a series of three cases in which compartment syndrome developed following hydrocarbon intramuscular injection of hydrocarbons and was successfully treated with urgent fasciotomy. The cases involve three young men who injected gasoline or diesel fuel in their arms and legs. In each case, urgent fasciotomy was necessary to evacuate the intramuscular collection that was rapidly expanding. The three patients were then discharged from our Surgical Department with no complications and were followed up in outpatient visits. ConclusionIntramuscular hydrocarbon injection can mainly lead to compartment syndrome and tissue necrosis. In the three cases we have reported, urgent fasciotomy successfully prevented ischemic damage to the limbs and facilitated the drainage of toxic substances, thereby preventing patient’s systemic poisoning and septic lethal consequences.

Antioxidant anthocyanin synergistic immune enhancer nanopeptide C-I20 remarkably enhances the protective effect of largemouth bass against largemouth bass ranavirus

Largemouth bass ranavirus (LMBV) infection results in huge economic losses in largemouth bass (Micropterus salmoides) industry. Nanopeptide C-I20 and anthocyanins have a positive effect on promoting immune responses and antioxidant mechanisms in several aquatic organisms, and are therefore used to inhibit LMBV infection. In this study, we developed an LMBV immersion challenge model using three different viral concentrations (1×104 copies/mL, 1×105 copies/mL, and 1×106 copies/mL) to infect largemouth bass, and LMBV-MCP mRNA expression was detected in infected fish. Following infection, the fish exhibited severe external ulceration, redness swelling, and darkening of the skin. Histopathological examination revealed significant necrosis and inflammation in muscle tissue, epithelial cell shedding in renal tubules, macrophage aggregation centers and cellular vacuolization in spleen and head kidney, and cellular hypertrophy in liver. To mitigate LMBV infection, we explored the protective effects of a combined treatment strategy involving C-I20 and anthocyanin. Overall, the combination of anthocyanin and C-I20 demonstrated the highest protective efficacy, significantly reducing viral loads in muscle, liver, spleen, and head kidney. Moreover, this treatment regimen enhanced antioxidant enzyme activities (T-AOC, TSOD, GSH-Px, CAT) and modulated important immune genes (IL-1, IL-8, TNF-α, IL-10, Mx, and IgM) expression. In conclusion, the synergistic application of anthocyanin and C-I20 demonstrates significant efficacy in mitigating LMBV infection. This research introduces a novel and promising approach to managing infectious diseases in aquaculture settings.

Molecular Identification, Histopathology and Antibiotic Susceptibility Profiling of Aeromonas veronii Isolated from Oreochromis niloticus in Bangladesh.

Tilapia (Oreochromis niloticus) is the most widely cultured freshwater fish species in Bangladesh and worldwide. However, commercial tilapia culture systems face increasing challenges from bacterial infections. The objective of this study was to identify the bacterial isolates from infected tilapia inan intensive cage culture farm located along the Shitalakshya River in Bangladesh. Infected fish samples were collected and underwentcomprehensive clinical and post-mortem investigations, followed by phenotypic, biochemical and molecular identification of the bacterial isolates, as well as histopathological and antibiotic susceptibility examinations. Phenotypic and biochemical characterization showed similarities of the -collected isolates with Aeromonas veronii. Moreover, molecular analysis of the bacterial conserved region 16S rRNA also confirmed these isolates as A. veronii. The analysed 16S rRNA sequence (GenBank accession no. PP832815) showed a close relationship (100% identity) with A. veronii from China (GenBank accession no. MT071624) in the NCBI BLAST search, and in the phylogenetic tree, they grouped in a single clade. This close genetic relationship is also supported by the low genetic distance between the isolates. Histopathological analysis revealed gross pathological changes like necrosis, hypertrophy and inflammation in muscle tissues. The isolates were found to be sensitive to multiple antibiotics but resistant to trimethoprim and sulphamethoxazole. This study investigated the presence of A. veronii infection in tilapia (O. niloticus) in an intensive cage culture farm in Bangladesh.

The biological effects of copper alloying in Zn-based biodegradable arterial implants

Biodegradable metals based on zinc are being developed to serve as temporary arterial scaffolding. Although the inclusion of copper is becoming more prevalent for grain refinement in zinc alloys, the biological activity of the copper component has not been well investigated. Here, two ZnCu alloys (0.8 and 1.5 wt% Cu) with and without thermal treatment were investigated for their hemocompatibility and biocompatibility. The microstructure was examined using scanning electron microscopy and X-ray diffraction. Zn-1.5Cu was found to contain nearly double the amount of second phase (CuZn5) precipitates as compared to Zn-0.8Cu. Thermal treatment dissolved a portion of the precipitates into the matrix. Since copper is a well-known catalyst for NO generation, the metals were tested both for their ability to generate NO release and for their thrombogenicity. Cellular responses and in vivo corrosion were characterized by a 6 months in vivo implantation of metal wires into rat arteries. The as-received Zn-1.5Cu displayed the least neointimal growth and smooth muscle cell presence, although inflammation was slightly increased. Thermal treatment was found to worsen the biological response, as determined by an increased neointimal size, increased smooth muscle cell presence and small regions of necrotic tissue. There were no trends in NO release between the alloys and thermal treatments. Corrosion progressed predominately through a pitting mechanism in vivo, which was more pronounced for the thermally treated alloys, with a more uniform corrosion seen for as-drawn Zn-1.5Cu. Differences in biological response are speculated to be due to changes in microstructure and pitting corrosion behavior.

Ascaris in infected pancreatic pancreatic necrosum: a case report of an intraoperative surprise

Introduction and importance: Ascariasis lumbricoides is a common gastrointestinal tract helminthic disease in developing countries and is also a cause of hepatobiliary and pancreatic disease in endemic areas of the world. Involvement of the pancreatic duct by worms and associated pancreatitis is less common than the hepatic and biliary involvement. Case presentation: A 38-year-old patient was admitted with a diagnosis of alcohol-induced acute pancreatitis and managed conservatively. However, the patient’s condition worsened after 2 weeks, and a CT scan revealed an acute necrotic collection with gas foci. After failed percutaneous pigtail catheter drainage, laparotomy was performed, revealing a necrotic collection in the right paracolic gutter, with the entire area frozen and a worm observed in the necrosum. The colon and small bowel were intact without perforation. The suspicion arose that the worm might have either migrated from a duodenal perforation, which had possibly sealed after the acute phase, or migrated from the major pancreatic duct. Debridement of easily accessible necrotic tissues was performed, and the patient was admitted to the intensive care unit (ICU). Unfortunately, the patient tested positive for COVID-19, and a few days later, blood was observed in the drain. Re-exploration revealed diffuse blood oozing, and the abdomen was closed with packing. Conclusion: The route of ascaris migration to necrosum or its association with severe acute pancreatitis needs to be ensured in endemic areas. Cautious use of antihelminthic therapy in endemic areas could prevent fatal pancreatobiliary complications and its associated mortality.

Hyperbaric Oxygen in Animal Model of Diabetes Nephropathy: Analysis of Blood Glucose, Proteinuria and Kidney Tissue Necrosis Cells

Hyperbaric Oxygen in Animal Model of Diabetes Nephropathy: Analysis of Blood Glucose, Proteinuria and Kidney Tissue Necrosis Cells

A novel protein elicitor (Cs08297) from Ciboria shiraiana enhances plant disease resistance.

Ciboria shiraiana is a necrotrophic fungus that causes mulberry sclerotinia disease resulting in huge economic losses in agriculture. During infection, the fungus uses immunity elicitors to induce plant tissue necrosis that could facilitate its colonization on plants. However, the key elicitors and immune mechanisms remain unclear in C. shiraiana. Herein, a novel elicitor Cs08297 secreted by C. shiraiana was identified, and it was found to target the apoplast in plants to induce cell death. Cs08297 is a cysteine-rich protein unique to C. shiraiana, and cysteine residues in Cs08297 were crucial for its ability to induce cell death. Cs08297 induced a series of defence responses in Nicotiana benthamiana, including the burst of reactive oxygen species (ROS), callose deposition, and activation of defence-related genes. Cs08297 induced-cell death was mediated by leucine-rich repeat (LRR) receptor-like kinases BAK1 and SOBIR1. Purified His-tagged Cs08297-thioredoxin fusion protein triggered cell death in different plants and enhanced plant resistance to diseases. Cs08297 was necessary for sclerotial development, oxidative-stress adaptation, and cell wall integrity but negatively regulated virulence of C. shiraiana. In conclusion, our results revealed that Cs08297 is a novel fungal elicitor in fungi inducing plant immunity. Furthermore, its potential to enhance plant resistance provides a new target to control agricultural diseases biologically.

Severe Vulvar Myiasis Case In A Crossbreed Limousin Cow

Background: Myiasis is caused by the infestation of Diptera fly larvae in vertebrate animals. In cases of myiasis, larvae will eat living or dead tissue, thereby expanding the infestation and infection of the host. Myiasis is a significant economic problem due to decreased productivity and tissue damage. Purpose: This study seeks to provide insights regarding managing and treating myiasis cases in cattle. Cases(s): The 4-year-old female Limousin cow was in the gestation period and kept in Buluagung Village, Pesanggaran, Banyuwangi. Based on the owner's statement, the cow experienced a decrease in appetite, and there were wounds in the vulva area accompanied by larvae, which had been present for five days. The clinical findings revealed an open wound that was red in color and soft in consistency, and there was an unpleasant odor in the vulva area. An infestation of Diptera fly larvae accompanied this. After the initial extraction of maggots, necrotic tissue, edema, friable tissue, and erythema were evident in the vulvar region and introitus. Case Management: Treatment carried out on the case cow involved cleaning the wound using 0.9% NaCl and removing both necrotic tissue and any larvae from the vulva wound using tweezers. The cow received an intramuscular injection of an analgesic and antipyretic (Sulprodon®) 7 mL, antihistamine (Prodryl®) 3 mL intramuscular injection, antibiotic (Limoxin-LA®) 10 mL, and multivitamin (Injectamin®) 7 mL. Conclusion: The vulvar myiasis in this cow was successfully cured with no more larvae found, and the wound dried out.

Development of Hybrid Implantable Local Release Systems Based on PLGA Nanoparticles with Applications in Bone Diseases

The current strategy for treating osteomyelitis includes surgical procedures for complete debridement of the formed biofilm and necrotic tissues, systemic and oral antibiotic therapy, and the clinical use of cements and three-dimensional scaffolds as bone defect fillers and delivery systems for therapeutic agents. The aim of our research was to formulate a low-cost hybrid nanoparticulate biomaterial using poly(lactic-co-glycolic acid) (PLGA), in which we incorporated the therapeutic agent (ciprofloxacin), and to deposit this material on titanium plates using the matrix-assisted pulsed laser evaporation (MAPLE) technique. The deposited material demonstrated antibacterial properties, with all analyzed samples inhibiting the growth of tested bacterial strains, confirming the release of active substances from the investigated biocomposite. The poly(lactic-co-glycolic acid)-ciprofloxacin (PLGA-CIP) nanoparticle scaffolds displayed a prolonged local sustained release profile over a period of 45 days, which shows great promise in bone infections. Furthermore, the burst release ensures a highly efficient concentration, followed by a constant sustained release which allows the drug to remain in the implant-adjacent area for an extended time period.

ESTRATÉGIAS DE PREVENÇÃO DE LESÃO POR PRESSÃO EM PACIENTES ACAMADOS: O PAPEL DA ENFERMAGEM

Pressure injuries (PPI) represent a serious public health problem that affects bedridden patients, especially in hospital environments, and can cause complications such as infections and tissue necrosis. This article aims to propose the implementation of PI prevention strategies in bedridden patients, focusing on the role of nursing. The research aims to identify effective prevention practices, such as position changes, risk assessment and use of pressure relief devices. The methodology adopted was a bibliographic review of articles published in the last ten years, using databases such as PubMed, Scielo and LILACS. Expected results include reducing the incidence of PPL, improving the quality of nursing care and promoting preventive protocols based on scientific evidence. It is concluded that the rigorous adoption of these strategies could significantly contribute to improving patient health and optimizing hospital resources. The main strategies identified include changing position, using pressure relief devices and risk assessment. It is concluded that this management significantly reduces the incidence of LPP, improving the quality of nursing care and promoting patient health.

030. Delayed Presentation of Blunt Traumatic Diaphragmatic Hernia 15 Years After Injury: A Case Report

Background: Traumatic diaphragmatic rupture is rare with incidence between 0.8-8% and often resulting from blunt or penetrating trauma. We present a case of delayed diaphragmatic hernia in a 41-year-old male, 15 years after blunt abdominal trauma. Case: A 41-year-old male presented with dyspnea and severe abdominal pain. He reported being struck in the abdomen with wood during a gang attack 15 years prior. A year after the accident, he complained of uncomfortable breathing that worsened in the past 6 years. Physical examination revealed decreased breath sounds on the left side and a distended abdomen. Imaging confirmed bowel herniation into the left hemithorax, partial lung collapse, and a mediastinal shift. Emergency laparotomy revealed a 5 cm diaphragmatic defect, massive gastric necrosis, and herniation of abdominal organs into the thoracic cavity. The defect was closed with primary repair, and necrotic gastric tissue was excised and repaired using primary closure with omental patch. The patient recovered well and was discharged on day 11. Conclusion: Diaphragmatic ruptures require prompt surgical repair to prevent complications. Physicians must carefully evaluate trauma history and conduct thorough examinations to improve outcomes in emergency settings.

In thermotolerance tests of tropical tree leaves, the chlorophyll fluorescence parameter Fv/Fm measured soon after heat exposure is not a reliable predictor of tissue necrosis.

Tropical rainforests are hot and may be particularly sensitive to ongoing anthropogenic global warming. This has led to increased interest in the thermotolerance of tropical trees. Thermotolerance of leaves of two tropical tree species, Terminalia catappa and Coccoloba uvifera, was determined by exposing leaf samples to 15-min heat treatments, followed by measurements of potential photosystem II quantum yield (dark-adapted value of variable/maximum chlorophyll a fluorescence, Fv/Fm) after 24 h and 14 days, and visible damage (necrosis) after 14 days. T50 (24 h), the temperature at which Fv/Fm declined by 50% 24 h after heat treatments, was associated with only ~10% leaf area damage in C. uvifera and no damage in T. catappa. In neither species was leaf necrosis observed at T5 (24 h), the temperature at which Fv/Fm declined by 5%. In both species, temperatures significantly higher than T50 (24 h) were required for 50% leaf area necrosis to occur. T50 (14 days) was a better proxy of visible leaf damage than T50 (24 h). The relationship between heat-induced Fv/Fm decline and tissue necrosis varies among species. In species surveys of leaf thermal tolerances, calibration of the Fv/Fm assay against the necrosis test is recommended for each species under investigation. Fv/Fm measurements soon after heat exposure do not reliably predict irreversible heat damage and may thus not be suitable to model and predict the thermostability of tropical forest trees.