NECASA I: A Practical Algorithm Integrating Skincare in the Management of Acne Patients in the Nordic European Countries.

BACKGROUND: Acne vulgaris is a multifactorial dermatosis primary of the face and trunk. Erythema, pruritus, and xerosis are frequent adverse effects of first-line acne treatment and, if not appropriately counseled and managed, can exacerbate, leading to regimen nonadherence and poor outcomes. METHODS: A panel of 6 dermatologists (five from the Nordic European Countries and one from the UK) employed a modified Delphi method and reached a consensus on a practical acne treatment and maintenance algorithm integrating skincare based on the best available evidence, and the panels' clinical experience, and opinions. RESULTS: The Nordic European Countries Acne Skincare Algorithm (NECASA) recommends integrating skincare and nonprescription acne treatment into acne regimens, addressing the relative lack of standardized guidance on their use as mono or adjunctives to acne treatment. The algorithm uses stratification by acne subtype and discusses management approaches per type of acne (comedonal, papulopustular, and nodulocystic acne), severity (mild to moderate and severe), and maintenance treatment. Skincare monotherapy may reduce acne lesions and maintain clearance in patients with mild acne. Adjunctive skincare may enhance the efficacy and improve tolerability of acne treatment, reduce pigmentary alterations, and improve skin barrier function. CONCLUSIONS: The NECASA algorithm may serve as a roadmap for integrating skincare in managing acne patients and tailoring acne treatment to improve adherence and tolerance to treatment and patient outcomes. J Drugs Dermatol. 2024;23(9):782-788. doi:10.36849/JDD.8472.

INDIVIDUAL ARTICLE: NECOM 4: Algorithm Integrating Skincare for the Management of Immunotherapy-Related Cutaneous Adverse Events for Cancer Patients and Survivors.

BACKGROUND: In the Nordic European Countries, cancer is the leading cause of death. The last decade has brought revolutionizing cancer treatments including immune checkpoint inhibitors (ICIs). Patients on ICIs have a high risk of developing cutaneous immune-related adverse events. Treating these side effects is of high importance to improve patient's quality of life (QoL) and continue the anti-cancer treatment. METHODS: The Nordic European Cutaneous Oncodermatology Management (NECOM) project develops tools to prevent and treat cancer therapy-related cutaneous adverse events (cAEs). The first 2 NECOM papers presented various cAEs and skincare regimens involving hygiene, moisturization, sun protection, and camouflage products for preventing and managing cAEs. The NECOM 3 practical algorithm was on the prevention and treatment of acute radiation dermatitis. This NECOM 4 practical algorithm is intended to prevent and manage cutaneous immunotherapy-related adverse events (cirAEs), improving cancer patients' QoL and outcomes. RESULTS: The NECOM advisors discussed the results of a systematic literature review and obtained consensus on the evidence and expert opinion-based practical algorithm for cirAEs to support all healthcare providers treating cancer patients in the Nordic European Countries. The algorithm starts with a simple skincare regimen of cleansing, moisturizing, and protection, followed by the exclusion of severe cutaneous adverse reactions, and then specific interventions to treat the most common cirAEs (pruritus, maculopapular eruption, eczematous eruption, psoriasis, lichenoid eruption, and bullous eruption). CONCLUSIONS: CirAEs are the most common side effects induced by ICIs and may lead to cancer treatment interruption or even discontinuation. Patient education on the prevention of cirAEs using a skincare regimen and treatment recommendations given in the NECOM 4 algorithm may help prevent and manage cirAEs and improve the QoL and outcome of patients receiving ICIs. J Drugs Dermatol. 2024;23:8(Suppl 2):s4-10.

Dynamic optical coherence tomography unveils subclinical, vascular differences across actinic keratosis grades I-III.

Actinic keratosis (AK) classification relies on clinical characteristics limited to the skin's surface. Incorporating sub-surface evaluation may improve the link between clinical classification and the underlying pathology. We aimed to apply dynamic optical coherence tomography (D-OCT) to characterize microvessels in AK I-III and photodamaged (PD) skin, thereby exploring its utility in enhancing clinical and dermatoscopic AK evaluation. This explorative study assessed AK I-III and PD on face or scalp. AK were graded according to the Olsen scheme before assessment with dermatoscopy and D-OCT. On D-OCT, vessel shapes, -pattern and -direction were qualitatively evaluated at predefined depths, while density and diameter were quantified. D-OCT's ability to differentiate between AK grades was compared with dermatoscopy. Forty-seven patients with AK I-III (n = 207) and PD (n = 87) were included. Qualitative D-OCT evaluation revealed vascular differences between AK grades and PD, particularly at a depth of 300 µm. The arrangement of vessel shapes around follicles differentiated AK II from PD (OR = 4.75, p < 0.001). Vessel patterns varied among AK grades and PD, showing structured patterns in AK I and PD, non-specific in AK II (OR = 2.16,p = 0.03) and mottled in AK III (OR = 29.94, p < 0.001). Vessel direction changed in AK II-III, with central vessel accentuation and radiating vessels appearing most frequently in AK III. Quantified vessel density was higher in AK I-II than PD (p ≤ 0.025), whereas diameter remained constant. D-OCT combined with dermatoscopy enabled precise differentiation of AK III versus AK I (AUC = 0.908) and II (AUC = 0.833). The qualitative and quantitative evaluation of vessels on D-OCT consistently showed increased vascularization and vessel disorganization in AK lesions of higher grades.

A global perspective on the treatment and maintenance of mature skin using gentle cleansers and moisturizers.

Xerosis is highly prevalent in the population aged over 50 years and substantially impacts quality of life due to the associated stigma, related pruritus, and potential sequelae. We propose that the term mature xerosis be used for subjects over 50 who suffer from age-related xerosis and replace senile xerosis to describe the phenomenon. The etiology of xerosis depends on genetic and environmental factors that affect stratum corneum hydration and skin barrier function. Skincare to restore barrier function is essential in xerosis treatment and is relevant for maintaining and preventing its progression. Many moisturizers and cleansers are available for xerosis; however, they are underutilized by patients with mature xerosis. A panel of eight global dermatologists reviewed the unique aspects of xerosis in mature skin and discussed the specific needs, relevance, and considerations for skincare selection to prevent, treat, and maintain skin with mature xerosis. The panel selected five statements based on evidence from a literature review and the panel's clinical experience to provide clinical considerations and recommendations for dermatologists and other healthcare providers treating patients with mature xerosis. Increased recognition of the burden of xerosis in mature skin is warranted. Gentle cleansers and barrier-restoring ceramide-containing moisturizers are essential to xerosis management, reducing signs and symptoms of xerosis, including associated pruritus.

Efficacy of Combinational Treatment versus Nicotinamide Monotherapy in the Prevention of Ultraviolet Radiation-Induced Skin Cancer.

INTRODUCTION: Ultraviolet radiation (UVR) is the primary risk factor for keratinocyte carcinomas. Oral supplementation with nicotinamide (NAM) is reported to reduce the formation of new keratinocyte carcinomas. NAM's photoprotection is mediated by enhanced DNA repair. We wanted to explore whether NAM in combination with antiproliferative (metformin [Met]) or antioxidant (phloroglucinol [PG]) compounds could potentially enhance its photoprotective effects. METHODS: Hairless mice (C3.Cg-Hrhr/TifBomTac) were treated orally with either a standard dose of NAM monotherapy (NAM-mono; 600 mg/kg) or NAM (400 mg/kg) combined with Met (200 mg/kg) (NAM-Met) or PG (75 mg/kg) (NAM-PG). Mice were irradiated with 3.5 standard erythema doses of UVR three times per week to induce tumour development. Photoprotective effects were based on (i) tumour onset of the first three tumours, (ii) skin photodamage, and (iii) DNA damage (cyclobutane pyrimidine dimers [CPDs] and pyrimidine-pyrimidone (6-4) photoproducts [6-4PPs]). RESULTS: All mice treated with NAM demonstrated a delay in tumour onset and reduced tumour burden compared to the UV control group (NAM, NAM-Met, NAM-PG vs. UV control: p ≤ 0.015). NAM-mono and NAM-PG increased time until all three tumours with no difference between them, indicating a similar degree of photoprotection. NAM-mono had no effect on DNA damage compared to the UV control group (p > 0.05), whereas NAM-PG reduced 6-4PP lesions (p < 0.01) but not CPDs (p > 0.05) compared to NAM-mono. NAM-Met delayed the onset of the third tumour compared to the UV control but demonstrated a quicker onset compared to NAM-mono, suggesting inferior photoprotection compared to nicotinamide monotherapy. CONCLUSION: NAM-PG was as effective in delaying UVR-induced tumour onset as NAM-mono. The reduction in 6-4PP lesions may indicate that the mechanism of NAM-PG is better suited for photoprotection than NAM-mono. NAM-mono was superior to NAM-Met, indicating a dose dependency of NAM's photoprotection. These results highlight the potential for combining photoprotective compounds to enhance photoprotection.

Pre-treatment with topical 5-fluorouracil increases the efficacy of daylight photodynamic therapy for actinic keratoses - A randomized controlled trial.

BACKGROUND: Daylight photodynamic therapy (dPDT) and topical 5-fluorouracil (5-FU) are each effective treatments for thin grade I actinic keratosis (AKs), but less so for thicker grade II-III AKs. Prolonged topical treatment regimens can be associated with severe skin reactions and low compliance. This study compares the efficacy of sequential 4 % 5-FU and dPDT with dPDT monotherapy for multiple actinic keratoses. METHODS: Sixty patients with a total of 1547 AKs (grade I: 1278; grade II: 246; grade III: 23) were treated in two symmetrical areas (mean size 75 cm2) of the face or scalp, which were randomized to (i) 4% 5-FU creme twice daily for 7 days before a single dPDT procedure and (ii) dPDT monotherapy. Daylight exposure was either outdoor or indoor daylight. RESULTS: Twelve weeks after treatment 87 % of all AKs cleared after 5-FU+dPDT compared to 74 % after dPDT alone (p<0.0001). For grade II AKs, the lesion response rate increased from 55 % with dPDT monotherapy to 79 % after 5-FU+dPDT (p<0.0056). Moderate/severe erythema was seen in 88 % 5-FU+dPDT areas compared to 41 % of dPDT areas two days after dPDT. Twelve weeks after treatment 75 % of the patients were very satisfied with both treatments. CONCLUSIONS: Sequential 5-FU and dPDT was more effective than dPDT monotherapy in the treatment of AKs, especially for grade II AKs. Local skin reactions were more pronounced after combination treatment, but no patients discontinued the treatment. The combination of 5-FU and dPDT is an effective treatment of large treatment areas with high compliance and satisfaction.

Oral intake of bucillamine, carvedilol, metformin, or phenformin does not protect against UVR-induced squamous cell carcinomas in hairless mice.

Squamous cell carcinoma represents the second most common type of keratinocyte carcinoma with ultraviolet radiation (UVR) making up the primary risk factor. Oral photoprotection aims to reduce incidence rates through oral intake of photoprotective compounds. Recently, drug repurposing has gained traction as an interesting source of chemoprevention. Because of their reported photoprotective properties, we investigated the potential of bucillamine, carvedilol, metformin, and phenformin as photoprotective compounds following oral intake in UVR-exposed hairless mice. Tumour development was observed in all groups in response to UVR, with only the positive control (Nicotinamide) demonstrating a reduction in tumour incidence (23.8%). No change in tumour development was observed in the four repurposed drug groups compared to the UV control group, whereas nicotinamide significantly reduced carcinogenesis (P = 0.00012). Metformin treatment significantly reduced UVR-induced erythema (P = 0.012), bucillamine and phenformin increased dorsal pigmentation (P = 0.0013, and P = 0.0005), but no other photoprotective effect was observed across the repurposed groups. This study demonstrates that oral supplementation with bucillamine, carvedilol, metformin, or phenformin does not affect UVR-induced carcinogenesis in hairless mice.

INDIVIDUAL ARTICLE: NECOM 3: A Practical Algorithm for the Management of Radiation Therapy-Related Acute Radiation Dermatitis.

BACKGROUND: In the Nordic European countries in 2020, cancer diagnoses accounted for 175,925 patients. About 50% of cancer patients receive radiation therapy (RT), which may lead to radiation dermatitis (RD). Notably, patients with breast, head, neck, and anal cancers may be prone to developing RD. However, few algorithms exist for the prevention and treatment of RD. METHODS: The Nordic European Cutaneous Oncodermatology Management (NECOM) project aims to improve cancer patient outcomes by offering tools to prevent and treat cancer therapy-related cutaneous adverse events (cAEs). The first 2 NECOM papers presented various cAEs and skincare regimens involving hygiene, moisturization, sun protection, and camouflage products for preventing and managing cAEs. The NECOM 3 practical algorithm for preventing and managing acute RD (ARD) is intended to promote healthy skin and reduce RT-related ARD, improving cancer patient outcomes.  Results: The NECOM advisors discussed the results of a systematic literature review and obtained consensus on the evidence and opinion-based practical algorithm for ARD to support all stakeholders in the Nordic European healthcare setting. The algorithm starts with skin-preserving therapy, followed by skin condition assessment and patient-specific interventions based on the grade of RD present.  Conclusion: ARD may lead to symptoms of pruritus and pain, decreased QoL and morbidity, and treatment interruptions. Patient education on the prevention of RD and treatment recommendations given in the NECOM 3 algorithm may help prevent and manage RD and improve the overall care of patients receiving RT. J Drugs Dermatol. 2023;22:11(Suppl 2):s3-s10.

Oral phytochemicals as photoprotectants in UVR exposed hairless mice: A study of hesperidin methyl chalcone, phloroglucinol, and syringic acid.

Ultraviolet radiation is the primary risk factor for keratinocyte carcinoma. Because of increasing incidence rates, new methods of photoprotection must be explored. Oral supplementation with photoprotective compounds presents a promising alternative. Phytochemical compounds like hesperidin methyl chalcone, phloroglucinol, and syringic acid are particularly of interest because of their antioxidant properties. Our primary outcome was to evaluate the effects of oral phytochemicals on photocarcinogenesis with time until tumour onset as the primary endpoint. A total of 125 hairless C3.Cg-Hrhr/TifBom Tac mice were randomised to receive tap water supplemented with either 100 mg/kg hesperidin methyl chalcone, phloroglucinol, or syringic acid, 600 mg/kg nicotinamide as a positive control, or no supplementation. The mice were irradiated with 3.5 standard erythema doses thrice weekly to induce photocarcinogenesis. Supplementation with the phytochemicals phloroglucinol and syringic acid and nicotinamide delayed tumour onset from a median of 140 days to 151 (p = 0.036), 157 days (p = 0.02), and 178 (p = 2.7·10-5), respectively. Phloroglucinol and nicotinamide supplementation reduced tumour number. Nicotinamide increased UV-induced pigmentation and reduced oedema formation, while phloroglucinol supplementation reduced epidermal thickness. These results indicate that oral supplementation with phloroglucinol and syringic acid protects against photocarcinogenesis in hairless mice, but not to the same extent as nicotinamide.

Improving the efficacy of photodynamic therapy for actinic keratosis: A comprehensive review of pharmacological pretreatment strategies.

BACKGROUND: Photodynamic therapy (PDT) is approved for treatment of actinic keratoses (AKs) and field-cancerisation. Pretreatment with pharmacological compounds holds potential to improve PDT efficacy, through direct interaction with PpIX formation or through an independent response, both of which may improve PDT treatment. OBJECTIVE: To present the currently available clinical evidence of pharmacological pretreatments prior to PDT and to associate potential clinical benefits with the pharmacological mechanisms of action of the individual compounds. METHODS: A comprehensive search on the Embase, MEDLINE, and Web of Science databases was performed. RESULTS: In total, 16 studies investigated 6 pretreatment compounds: 5-fluorouracil (5-FU), diclofenac, retinoids, salicylic acid, urea, and vitamin D. Two of these, 5-FU and vitamin D, robustly increased the efficacy of PDT across multiple studies, illustrated by mean increases in clearance rates of 21.88% and 12.4%, respectively. Regarding their mechanisms, 5-FU and vitamin D both increased PpIX accumulation, while 5-FU also induced a separate anticarcinogenic response. Pretreatment with diclofenac for four weeks improved the clearance rate in one study (24.9%), administration of retinoids had a significant effect in one of two studies (16.25%), while salicylic acid and urea did not lead to improved PDT efficacy. Diclofenac and retinoids demonstrated independent cytotoxic responses, whereas salicylic acid and urea acted as penetration enhancers to increase PpIX formation. CONCLUSION: 5-FU and vitamin D are well-tested, promising candidates for pharmacological pretreatment prior to PDT. Both compounds affect the haem biosynthesis, providing a target for potential pretreatment candidates. KEY WORDS: Photodynamic Therapy, Actinic Keratosis,Pre-tretment,Review,enhancement.

Supplement Individual Article: NECOM Skincare Algorithm for Patients With Cancer and Survivors.

BACKGROUND: Cancer treatment-related cutaneous adverse events (cAEs) frequently occur, which can interfere with anticancer treatment outcomes and can severely impact quality of life for patients. METHODS: The Nordic European Cutaneous Oncodermatology Management (NECOM) project aims to improve cancer patient outcomes by offering tools for preventing and managing cAEs. The first NECOM paper explored clinical insights in cAEs and focused on skincare regimens involving hygiene, moisturization, sun protection, and camouflage products. A skincare algorithm for patients with cancer and survivors follows this article to promote healthy skin and reduce cancer treatment-related cAEs. RESULTS: The NECOM panel discussed and reached a consensus on an evidence- and opinion-based practical algorithm for oncology skin care to support all stakeholders in the Nordic European health care setting. The oncology nurse is central in coordinating individual patient’s cancer care and performing triage for cAEs, seeking urgent care via an oncologist and/or the emergency department if needed. The care organization of the presented cAEs depends on the patient's general health and skin condition and the health care system. CONCLUSION: Communication on state-of-the-art treatment in the fast-evolving area of oncology is necessary to provide tailored general measures and skin care for cAEs supported by evidence and practice-based expert recommendations.J Drugs Dermatol. 2023;22:1(Suppl 2):s3-10.

Highlighting nuances of blue light phototherapy: Mechanisms and safety considerations.

The efficacy of blue light therapy in dermatology relies on numerous clinical studies. The safety remains a topic of controversy, where potentially deleterious effects were derived from in vitro rather than in vivo experiments. The objectives of this work were (1) to highlight the nuances behind "colors" of blue light, light propagation in tissue and the plurality of modes of action; and (2) to rigorously analyze studies on humans reporting both clinical and histological data from skin biopsies with focus on DNA damage, proliferation, apoptosis, oxidative stress, impact on collagen, elastin, immune cells, and pigmentation. We conclude that blue light therapy is safe for human skin. It induces intriguing skin pigmentation, in part mediated by photoreceptor Opsin-3, which might have a photoprotective effect against ultraviolet irradiation. Future research needs to unravel photochemical reactions and the most effective and safe parameters of blue light in dermatology.

The effect of induced hyperammonaemia on sleep and melanopsin-mediated pupillary light response in patients with liver cirrhosis: A single-blinded randomized crossover trial.

BACKGROUND & AIMS: Sleep disturbances are related to hepatic encephalopathy and hyperammonaemia in patients with cirrhosis. The circadian rhythm is regulated by light stimulation of the retina via melanopsin-containing ganglion cells. The study aimed to investigate whether induced hyperammonaemia affects the pupillary light response and sleep efficiency in patients with cirrhosis. METHODS: The study was a single-blinded crossover trial including nine patients with cirrhosis. Sleep was evaluated by Pittsburgh Sleep Quality Index (PSQI) and monitored for twelve nights with wrist accelerometers and sleep diaries. On two experimental days, separated by one week, patients were randomized to ingest either an oral amino acid challenge (AAC) or an isocaloric glucose solution (GS). We measured pupillary light response, capillary ammonia, the Karolinska Sleepiness Scale (KSS), and two neuropsychological tests on both experimental days. RESULTS: The patients had poor self-assessed sleep quality. The amino acid challenge led to a significant increase in capillary ammonia and KSS. The time spent in bed sleeping after AAC was longer and with a reduced movement index compared to baseline but not different from GS. We found no difference in the pupillary light response or neuropsychiatric tests when comparing the effect of AAC with GS. CONCLUSIONS: Patients with cirrhosis had impaired sleep quality. Induced hyperammonaemia led to increased sleepiness but had no acute effect on pupillary light response or the neuropsychiatric tests. TRIAL REGISTRATION: Registration number: NCT04771104.

Keratinocyte Carcinoma and Photoprevention: The Protective Actions of Repurposed Pharmaceuticals, Phytochemicals and Vitamins.

Ultraviolet radiation (UVR) arising from sun exposure represents a major risk factor in the development of keratinocyte carcinomas (KCs). UVR exposure induces dysregulated signal transduction, oxidative stress, inflammation, immunosuppression and DNA damage, all of which promote the induction and development of photocarcinogenesis. Because the incidence of KCs is increasing, better prevention strategies are necessary. In the concept of photoprevention, protective compounds are administered either topically or systemically to prevent the effects of UVR and the development of skin cancer. In this review, we provide descriptions of the pathways underlying photocarcinogenesis and an overview of selected photoprotective compounds, such as repurposed pharmaceuticals, plant-derived phytochemicals and vitamins. We discuss the protective potential of these compounds and their effects in pre-clinical and human trials, summarising the mechanisms of action involved in preventing photocarcinogenesis.

Effects of Er:YAG laser treatment on re-vascularization and follicle survival in frozen/thawed human ovarian cortex transplanted to immunodeficient mice.

PURPOSE: The huge loss of ovarian follicles after transplantation of frozen/thawed ovarian tissue is considered a major drawback on the efficacy of the procedure. Here we investigate whether Er:YAG laser treatment prior to xenotransplantation can improve re-vascularization and subsequently follicle survival in human ovarian tissue. METHODS: A total of 99 frozen/thawed human ovarian cortex pieces were included of which 72 pieces from 12 woman were transplanted to immunodeficient mice. Tissues from each woman were included in both an 8-day and an 8-week duration study and treated with either full-beam laser (L1) or fractionated laser (L2), or served as untreated controls. Vascularization of the ovarian xenografts were evaluated after 8 days by qPCR and murine Cd31 immunohistochemical analysis. Follicle densities were evaluated histologically 8 weeks after xenografting. RESULTS: Gene expression of Vegf/VEGF was upregulated after L1 treatment (p=0.002, p=0.07, respectively), whereas Angpt1, Angpt2, Tnf-α, and Il1-ß were significantly downregulated. No change in gene expression was found in Cd31/CD31, ANGPT1, ANGPT2, ANGTPL4, XBP1, or LRG1 after any of the laser treatments. The fraction of Cd31 positive cells were significantly reduced after L1 and L2 treatment (p<0.0001; p=0.0003, respectively), compared to controls. An overall negative effect of laser treatment was detected on follicle density (p=0.03). CONCLUSIONS: Er:YAG laser treatment did not improve re-vascularization or follicle survival in human ovarian xenografts after 8 days and 8 weeks grafting, respectively. However, further studies are needed to fully explore the potential angiogenic effects of controlled tissue damage using different intensities or lasers.

COVID-19 reopening causes high risk of irritant contact dermatitis in children.

INTRODUCTION: Childhood irritant contact dermatitis (ICD) is the most common cause for developing chronic hand eczema as an adult. The COVID-19 reopening in Denmark included regulations introducing frequent hand washing. The aim of the present study was to evaluate if frequent hand washing increases the incidence of ICD in children. METHODS: We conducted an observational study in Denmark during the reopening of schools and daycare facilities for children aged 0-12 years (April 22nd to May 1st 2020). A questionnaire was sent out to parents in four municipalities consisting of 20 questions about frequency of hand washing, use of hand sanitiser, symptoms of ICD, atopic dermatitis, allergy and predispositions. RESULTS: The study included 6,273 children. In children without any prior symptoms of dermatitis, 42.4% experienced ICD (dry, red and itchy skin) due to increased hand hygiene. Schoolchildren had a 1.5 times greater relative risk of developing ICD than preschool children. Frequency of hand washing was a strong risk factor, whereas this was not the case for alcohol-based hand sanitiser. Hand washing 7-10 times/day and >10 times/day increased the relative risk by 1.83 and 2.23 times, respectively. CONCLUSIONS: A higher frequency of hand washing during the COVID-19 reopening increased the incidence of ICD in children. Hand hygiene is essential in our fight against novel coronavirus, but prophylactic initiatives are important to reduce the possible long-term consequences of ICD in children. FUNDING: none TRIAL REGISTRATION: Clinicaltrials.gov (NCT04375410).

Increased oxidation of RNA despite reduced mitochondrial respiration after chronic electroconvulsive stimulation of rat brain tissue.

Major depressive disorder (MDD) affects 350 million people worldwide and is a serious socio-economic burden. The most efficient treatment of MDD is electroconvulsive therapy (ECT), which has been shown to influence the oxidative status believed to be part of the pathophysiology of MDD. We investigated the effects of chronic electroconvulsive stimulation (ECS) on mitochondrial respiration and mitochondrial hydrogen peroxide production, RNA oxidation, and the content of mitochondria in the piriform cortex of the rat. We found reductions of mitochondrial respiration in respiratory states 2 and 3 by 33% and 32%, respectively, and a 23% reduction in electron transfer capacity. RNA oxidation, as measured by 8-oxo-7,8-dihydroguanosine, was increased by 58%, while mitochondrial production of H2O2 was unaffected. The increased oxidative stress may thus be ascribed to extra-mitochondrial sources.

Cerebral Blood Flow and Metabolism in Hepatic Encephalopathy-A Meta-Analysis.

Hepatic Encephalopathy (HE) is associated with abnormalities in brain metabolism of glucose, oxygen and amino acids. In patients with acute liver failure, cortical lactate to pyruvate ratio is increased, which is indicative of a compromised cerebral oxidative metabolism. In this meta-analysis we have reviewed the published data on cerebral blood flow and metabolic rates from clinical studies of patients with HE. We found that hepatic encephalopathy was associated with reduced cerebral metabolic rate of oxygen, glucose, and blood flow. One exemption was in HE type B (shunt/by-pass) were a tendency towards increased cerebral blood flow was seen. We speculate that HE is associated with a disturbed metabolism-cytopathic hypoxia-and that type specific differences of brain metabolism is due to differences in pathogenesis of HE.

Impaired cerebral microcirculation induced by ammonium chloride in rats is due to cortical adenosine release.

BACKGROUND & AIMS: Liver failure results in hyperammonaemia, impaired regulation of cerebral microcirculation, encephalopathy, and death. However, the key mediator that alters cerebral microcirculation remains unidentified. In this study we show that topically applied ammonium significantly increases periarteriolar adenosine tone on the brain surface of healthy rats and is associated with a disturbed microcirculation. METHODS: Cranial windows were prepared in anaesthetized Wistar rats. The flow velocities were measured by speckle contrast imaging and compared before and after 30 min of exposure to 10 mM ammonium chloride applied on the brain surface. These flow velocities were compared with those for control groups exposed to artificial cerebrospinal fluid or ammonium plus an adenosine receptor antagonist. A flow preservation curve was obtained by analysis of flow responses to a haemorrhagic hypotensive challenge and during stepwise exsanguination. The periarteriolar adenosine concentration was measured with enzymatic biosensors inserted in the cortex. RESULTS: After ammonium exposure the arteriolar flow velocity increased by a median (interquartile range) of 21.7% (23.4%) vs. 7.2% (10.2%) in controls (n = 10 and n = 6, respectively, p <0.05), and the arteriolar surface area increased. There was a profound rise in the periarteriolar adenosine concentration. During the hypotensive challenge the flow decreased by 27.8% (14.9%) vs. 9.2% (14.9%) in controls (p <0.05). The lower limit of flow preservation remained unaffected, 27.7 (3.9) mmHg vs. 27.6 (6.4) mmHg, whereas the autoregulatory index increased, 0.29 (0.33) flow units per millimetre of mercury vs. 0.03 (0.21) flow units per millimetre of mercury (p <0.05). When ammonium exposure was combined with topical application of an adenosine receptor antagonist, the autoregulatory index was normalized. CONCLUSIONS: Vasodilation of the cerebral microcirculation during exposure to ammonium chloride is associated with an increase in the adenosine tone. Application of a specific adenosine receptor antagonist restores the regulation of the microcirculation. This indicates that adenosine could be a key mediator of the brain dysfunction seen during hyperammonaemia and is a potential therapeutic target. LAY SUMMARY: In patients with liver failure, disturbances in brain function are caused in part by ammonium toxicity. In our project we studied how ammonia, through adenosine release, affects the blood flow in the brain of rats. In our experimental model we demonstrated that the detrimental effect of ammonia on blood flow regulation was counteracted by blocking the adenosine receptors in the brain. With this observation we identified a novel potential treatment target. If we can confirm our findings in a future clinical study, this might help patients with liver failure and the severe condition called hepatic encephalopathy.