Polydopamine Adhesion: Catechol, Amine, Dihydroxyindole, and Aggregation Dynamics

While polydopamine (PDA) possesses the surface-independent adhesion property of mussel-binding proteins, significant differences exist between them. Particularly, PDA's short and rigid backbone differs from the long and flexible protein sequence of mussel-binding proteins. Given that adhesion relies on achieving a conformal contact with large surface coverage, PDA has drawbacks as an adhesive. In our study, we investigated the roles of each building block of PDA to build a better understanding of their binding mechanisms. Initially, we anticipated that catecholamine oligomers form specific binding with substrates. However, our study showed that the universal adhesion of PDA is initiated by the solubility limit of growing oligomers by forming agglomerates, complemented by multiple binding modes of catechol. Notably, in the absence of amines, poly(catechol) either remained in solution or formed minor suspensions without any surface coating, underscoring the essential role of amines in the adhesion process by facilitating insoluble aggregate formation. To substantiate our findings, we induced poly(catechol) aggregation using quaternized poly(4-vinylpyridine) (qPVP), leading to subsequent surface adhesion upon agglomerate formation.

Differential Modulation of Catecholamine and Adipokine Secretion by the Short Chain Fatty Acid Receptor FFAR3 and α2-Adrenergic Receptors in PC12 Cells

Sympathetic nervous system (SNS) hyperactivity is mediated by elevated catecholamine (CA) secretion from the adrenal medulla, as well as enhanced norepinephrine (NE) release from peripheral sympathetic nerve terminals. Adrenal CA production from chromaffin cells is tightly regulated by sympatho-inhibitory α2-adrenergic (auto)receptors (ARs), which inhibit both epinephrine (Epi) and NE secretion via coupling to Gi/o proteins. α2-AR function is, in turn, regulated by G protein-coupled receptor (GPCR)-kinases (GRKs), especially GRK2, which phosphorylate and desensitize them, i.e., uncouple them from G proteins. On the other hand, the short-chain free fatty acid (SCFA) receptor (FFAR)-3, also known as GPR41, promotes NE release from sympathetic neurons via the Gi/o-derived free Gβγ-activated phospholipase C (PLC)-β/Ca2+ signaling pathway. However, whether it exerts a similar effect in adrenal chromaffin cells is not known at present. In the present study, we examined the interplay of the sympatho-inhibitory α2A-AR and the sympatho-stimulatory FFAR3 in the regulation of CA secretion from rat adrenal chromaffin (pheochromocytoma) PC12 cells. We show that FFAR3 promotes CA secretion, similarly to what GRK2-dependent α2A-AR desensitization does. In addition, FFAR3 activation enhances the effect of the physiologic stimulus (acetylcholine) on CA secretion. Importantly, GRK2 blockade to restore α2A-AR function or the ketone body beta-hydroxybutyrate (BHB or 3-hydroxybutyrate), via FFAR3 antagonism, partially suppress CA production, when applied individually. When combined, however, CA secretion from PC12 cells is profoundly suppressed. Finally, propionate-activated FFAR3 induces leptin and adiponectin secretion from PC12 cells, two important adipokines known to be involved in tissue inflammation, and this effect of FFAR3 is fully blocked by the ketone BHB. In conclusion, SCFAs can promote CA and adipokine secretion from adrenal chromaffin cells via FFAR3 activation, but the metabolite/ketone body BHB can effectively inhibit this action.

Impaired metabolic flexibility to fasting is associated with increased ad libitum energy intake in healthy adults

OBJECTIVE

We investigated how changes in 24-h respiratory exchange ratio (RER) and substrate oxidation during fasting versus an energy balance condition influence subsequent ad libitum food intake.

METHODS

Forty-four healthy, weight-stable volunteers (30 male and 14 female; mean [SD], age 39.3 [11.0] years; BMI 31.7 [8.3] kg/m2) underwent 24-h energy expenditure measurements in a respiratory chamber during energy balance (50% carbohydrate, 30% fat, and 20% protein) and 24-h fasting. Immediately after each chamber stay, participants were allowed 24-h ad libitum food intake from computerized vending machines.

RESULTS

Twenty-four-hour RER decreased by 9.4% (95% CI: -10.4% to -8.5%; p < 0.0001) during fasting compared to energy balance, reflecting a decrease in carbohydrate oxidation (mean [SD], -2.6 [0.8] MJ/day; p < 0.0001) and an increase in lipid oxidation (2.3 [0.9] MJ/day; p < 0.0001). Changes in 24-h RER and carbohydrate oxidation in response to fasting were correlated with the subsequent energy intake such that smaller decreases in fasting 24-h RER and carbohydrate oxidation, but not lipid oxidation, were associated with greater energy intake after fasting (r = 0.31, p = 0.04; r = 0.40, p = 0.007; and r = -0.27, p = 0.07, respectively).

CONCLUSIONS

Impaired metabolic flexibility to fasting, reflected by an inability to transition away from carbohydrate oxidation, is linked with increased energy intake.

Cardiogenic pulmonary edema - is it lone cardiogenic? "Missing link" between hemodynamic and other existing mechanisms

The current traditional pathophysiologic concept of pulmonary edema of cardiogenic origin explains its development by a hydrostatic effect due to increased pulmonary capillary pressure resulting in fluid flux to alveolar and interstitial areas from capillaries. However, several experimental studies and clinical data of poor response to hemodynamic and diuretic treatment in many scenarios provide further evidence of the involvement of several other contributing factors to the development of cardiogenic pulmonary edema. Several experimental and clinical studies have found that sympathetic overactivity with elevated plasma catecholamine concentrations may play an important role in the development of cardiovascular-associated pulmonary edema. Catecholamine-induced pulmonary injury may be one of the key mechanisms in acute cardiogenic pulmonary edema triggering proinflammatory cytokine overactivation, oxidative stress and myocardial injury. In the everyday treatment of acute heart failure, physicians should consider the possibility of other noncardiogenic mechanisms involved in the progression of acute pulmonary edema, particularly catecholamine overactivity, lymphatic drainage, inflammatory and oxidative stress, high surfactant protein. The classic, hemodynamic treatment approach in pulmonary edema with the coexistence of other contributing factors may not provide adequate clinical benefit during treatment.

Non-paroxysmal junctional tachycardia complicating disseminated intravascular coagulation during massive surgical hemorrhage: A case report

RATIONALE

Non-paroxysmal junctional tachycardia (NPJT) is a self-limiting supraventricular tachycardia associated with primary heart disease, cardiac surgery, digitalis toxicity, and metabolic or electrolyte imbalances. However, NPJT caused enhanced normal automaticity even in the absence of structural heart disease can be fatal if not managed properly.

PATIENT CONCERNS

A 74-year-old hypertensive female patient was scheduled for transureteroureterostomy and right ureteroneocystostomy under general anesthesia.

DIAGNOSIS

The patient developed NPJT without visible P wave and severe hypotension due to adrenergic stimulation in response to massive hemorrhage during surgery.

INTERVENTIONS

NPJT with hypotension was initially converted to sinus rhythm with normotension with administration of adenosine and esmolol. However uncontrolled surgical hemorrhage and administration of large dose of vasopressors eventually perpetuated NPJT refractory to antiarrhythmic drugs.

OUTCOMES

Despite intravenous fluid resuscitation and massive transfusion, the patient was deteriorated hemodynamically due to uncontrolled bleeding and persistent NPJT, which resulted in hypovolemic shock and fatal disseminated intravascular coagulation (DIC).

LESSONS

NPJT can occur by enhanced automaticity due to increased catecholamine during severe surgical hemorrhage. Although NPJT is generally self-limiting, it can be refractory to antiarrhythmic agents and accelerate hypotension if the surgical bleeding is uncontrolled. Therefore, aggressive management of the primary pathologic condition is crucial for the management of NPJT and hemodynamic collapse even in the absence of structural heart disease.

Diabetic Ketoacidosis: A Rare Complication of Type 3c Diabetes

Recently termed pancreoprivic diabetes, type 3c diabetes refers to high blood sugar values secondary to disease of the exocrine pancreas. The disease is most commonly misdiagnosed as type 2 diabetes mellitus (DM) and is overlooked by physicians and the general public. Chronic pancreatitis (CP) accounts for most cases of type 3c diabetes. Diabetic ketoacidosis (DKA) is a rare occurrence in type 3c diabetes as both alpha and beta cell dysfunction occur concurrently. In this case, the major hormones involved in lipolysis and ketone body production would be catecholamines, cortisol, and growth hormone. We report a case of a 37-year-old female with a history of endocrine pancreatic insufficiency secondary to CP who presented with DKA, one of the life-threatening but preventable complications of diabetes. Noncompliance with insulin and concurrent urinary tract infection were the inciting factors. Her condition improved with DKA management according to standard protocol, intravenous antibiotics, and other supportive care. She got discharged after optimization of insulin therapy, with proper advice for home blood sugar monitoring and regular follow-up. A patient with pancreatic pathology may present to the emergency with DKA as the first manifestation, and if not properly evaluated, the diagnosis of type 3c diabetes can be missed.

mTORC1 hyperactivation and resultant suppression of macroautophagy contribute to the induction of cardiomyocyte necroptosis by catecholamine surges

Previous studies revealed a controversial role of mechanistic target of rapamycin complex 1 (mTORC1) and mTORC1-regulated macroautophagy in isoproterenol (ISO)-induced cardiac injury. Here we investigated the role of mTORC1 and potential underlying mechanisms in ISO-induced cardiomyocyte necrosis. Two consecutive daily injections of ISO (85 mg/kg, s.c.) or vehicle control (CTL) were administered to C57BL/6J mice with or without rapamycin (RAP, 5 mg/kg, i.p.) pretreatment. Western blot analyses showed that myocardial mTORC1 signaling and the RIPK1-RIPK3-MLKL necroptotic pathway were activated, mRNA expression analyses revealed downregulation of representative TFEB target genes, and Evan's blue dye uptake assays detected increased cardiomyocyte necrosis in ISO-treated mice. However, RAP pretreatment prevented or significantly attenuated the ISO-induced cardiomyocyte necrosis, myocardial inflammation, downregulation of TFEB target genes, and activation of the RIPK1-RIPK3-MLKL pathway. LC3-II flux assays confirmed the impairment of myocardial autophagic flux in the ISO-treated mice. In cultured neonatal rat cardiomyocytes, mTORC1 signaling was also activated by ISO, and inhibition of mTORC1 by RAP attenuated ISO-induced cytotoxicity. These findings suggest that mTORC1 hyperactivation and resultant suppression of macroautophagy play a major role in the induction of cardiomyocyte necroptosis by catecholamine surges, identifying mTORC1 inhibition as a potential strategy to treat heart diseases with catecholamine surges.

65 years of research on dopamine's role in classical fear conditioning and extinction: A systematic review

Dopamine, a catecholamine neurotransmitter, has historically been associated with the encoding of reward, whereas its role in aversion has received less attention. Here, we systematically gathered the vast evidence of the role of dopamine in the simplest forms of aversive learning: classical fear conditioning and extinction. In the past, crude methods were used to augment or inhibit dopamine to study its relationship with fear conditioning and extinction. More advanced techniques such as conditional genetic, chemogenic and optogenetic approaches now provide causal evidence for dopamine's role in these learning processes. Dopamine neurons encode conditioned stimuli during fear conditioning and extinction and convey the signal via activation of D1-4 receptor sites particularly in the amygdala, prefrontal cortex and striatum. The coordinated activation of dopamine receptors allows for the continuous formation, consolidation, retrieval and updating of fear and extinction memory in a dynamic and reciprocal manner. Based on the reviewed literature, we conclude that dopamine is crucial for the encoding of classical fear conditioning and extinction and contributes in a way that is comparable to its role in encoding reward.

Omega-3 and -6 Fatty Acids Alter the Membrane Lipid Composition and Vesicle Size to Regulate Exocytosis and Storage of Catecholamines

The two essential fatty acids, alpha-linolenic acid and linoleic acid, and the higher unsaturated fatty acids synthesized from them are critical for the development and maintenance of normal brain functions. Deficiencies of these fatty acids have been shown to cause damage to the neuronal development, cognition, and locomotor function. We combined electrochemistry and imaging techniques to examine the effects of the two essential fatty acids on catecholamine release dynamics and the vesicle content as well as on the cell membrane phospholipid composition to understand how they impact exocytosis and by extension neurotransmission at the single-cell level. Incubation of either of the two fatty acids reduces the size of secretory vesicles and enables the incorporation of more double bonds into the cell membrane structure, resulting in higher membrane flexibility. This subsequently affects proteins regulating the dynamics of the exocytotic fusion pore and thereby affects exocytosis. Our data suggest a possible pathway whereby the two essential fatty acids affect the membrane structure to impact exocytosis and provide a potential treatment for diseases and impairments related to catecholamine signaling.

Optical Control of Cell-Surface and Endomembrane-Exclusive β-Adrenergic Receptor Signaling

Beta-adrenergic receptors (βARs) are G protein-coupled receptors (GPCRs) that mediate catecholamine-induced stress responses, such as heart rate increase and bronchodilation. In addition to signals from the cell surface, βARs also broadcast non-canonical signaling activities from the cell interior membranes (endomembranes). Dysregulation of these receptor pathways underlies severe pathological conditions. Excessive βAR stimulation is linked to cardiac hypertrophy, leading to heart failure, while impaired stimulation causes compromised fight or flight stress responses and homeostasis. In addition to plasma membrane βAR, emerging evidence indicates potential pathological implications of deeper endomembrane βARs, such as inducing cardiomyocyte hypertrophy and apoptosis, underlying heart failure. However, the lack of approaches to control their signaling in subcellular compartments exclusively has impeded linking endomembrane βAR signaling with pathology. Informed by the β1AR-catecholamine interactions, we engineered an efficiently photo-labile, protected hydroxy β1AR pro-ligand (OptoIso) to trigger βAR signaling at the cell surface, as well as exclusive endomembrane regions upon blue light stimulation. Not only does OptoIso undergo blue light deprotection in seconds, but it also efficiently enters cells and allows examination of G protein heterotrimer activation exclusively at endomembranes. In addition to its application in the optical interrogation of βARs in unmodified cells, given its ability to control deep organelle βAR signaling, OptoIso will be a valuable experimental tool.

Successful extracorporeal membrane oxygenation treatment of catecholamine-induced cardiomyopathy-associated pheochromocytoma: a case report

The main mechanism of Takotsubo cardiomyopathy (TCM) is catecholamine-induced acute myocardial stunning. Pheochromocytoma, a catecholamine-secreting tumor, can cause several cardiovascular complications, including hypertensive crisis, myocardial infarction, toxic myocarditis, and TCM. A 29-year-old woman presented to our hospital with general weakness, vomiting, dyspnea, and chest pain. The patient was nullipara, 28 weeks' gestation, and had a cachexic morphology. Her cardiac enzyme levels were elevated and bedside echocardiography showed apical akinesia, suggesting TCM. The next day, she could not feel the fetal movement, and an emergency cesarean section was performed. After delivery, the patient experienced cardiac arrest and was transferred to the intensive care unit for cardiopulmonary resuscitation (CPR). Spontaneous circulation returned after 28 minutes of CPR, but cardiogenic shock continued, and extracorporeal membrane oxygenation (ECMO) was initiated. On the third day of ECMO maintenance, left ventricular ejection fraction improved and blood pressure stabilized. On the eighth day after ECMO insertion, it was removed. However, complications of the left leg vessels occurred, and several surgeries and interventions were performed. A left adrenal gland mass was found on computed tomography and was removed while repairing the leg vessels. Pheochromocytoma was diagnosed and left adrenalectomy was performed.

Pheochromocytoma With High Adrenocorticotropic Hormone Production Capacity Without Pigmentation and Cushingoid Symptoms: A Case Report With a Literature Review

Pheochromocytoma or paraganglioma (PPGL) originating from chromaffin cells can produce diverse hormones in addition to catecholamines, including adrenocorticotropic hormone (ACTH). In pheochromocytoma, high levels of ACTH might not result in pigmentation as typically observed in Addison's disease, and patients might not exhibit the symptoms of Cushing's syndrome, despite ACTH-dependent hypercortisolism. A 63-year-old male patient with hypertension was admitted to our facility, and computed tomography (CT) revealed a large right adrenal tumor. Despite high plasma ACTH (700-1300 pg/mL) and serum cortisol (90-100 µg/dL) levels, no physical pigmentation or Cushingoid symptoms were observed. Urinary metanephrine and normetanephrine levels reached as high as 16.0 mg and 3.2 mg, respectively. 123I-metaiodobenzylguanidine (MIBG) scintigraphy was negative. Low-dose dexamethasone paradoxically increased ACTH and cortisol levels, indicating the potential positive feedback regulation of both hormones by glucocorticoids. The patient was diagnosed with an ACTH-producing pheochromocytoma and underwent successful laparoscopic surgery to remove the adrenal tumor under the intravenous administration of a high-dose α-blocker and hydrocortisone. The levels of ACTH, cortisol, and urinary metanephrine/normetanephrine returned close to normal after tumor removal. We report a rare case of pheochromocytoma with extremely high ACTH/cortisol production but without pigmentation or Cushingoid symptoms. We also reviewed previous reports of ACTH-producing PPGL regarding the paradoxical regulation of ACTH/cortisol by glucocorticoids, pigmentation, Cushingoid symptoms, and negativity of 123I-MIBG scintigraphy.

Neuromelanin-sensitive MRI as a promising biomarker of catecholamine function

Disruptions to dopamine and noradrenergic neurotransmission are noted in several neurodegenerative and psychiatric disorders. Neuromelanin-sensitive (NM)-MRI offers a non-invasive approach to visualize and quantify the structural and functional integrity of the substantia nigra and locus coeruleus. This method may aid in the diagnosis and quantification of longitudinal changes of disease and could provide a stratification tool for predicting treatment success of pharmacological interventions targeting the dopaminergic and noradrenergic systems. Given the growing clinical interest in NM-MRI, understanding the contrast mechanisms that generate this signal is crucial for appropriate interpretation of NM-MRI outcomes and for the continued development of quantitative MRI biomarkers that assess disease severity and progression. To date, most studies associate NM-MRI measurements to the content of the neuromelanin pigment and/or density of neuromelanin-containing neurons, while recent studies suggest that the main source of the NM-MRI contrast is not the presence of neuromelanin but the high-water content in the dopaminergic and noradrenergic neurons. In this review, we consider the biological and physical basis for the NM-MRI contrast and discuss a wide range of interpretations of NM-MRI. We describe different acquisition and image processing approaches and discuss how these methods could be improved and standardized to facilitate large-scale multisite studies and translation into clinical use. We review the potential clinical applications in neurological and psychiatric disorders and the promise of NM-MRI as a biomarker of disease, and finally, we discuss the current limitations of NM-MRI that need to be addressed before this technique can be utilized as a biomarker and translated into clinical practice and offer suggestions for future research.

Possible Molecular Mechanisms of Hypertension Induced by Sleep Apnea Syndrome/Intermittent Hypoxia

Intermittent hypoxia (IH) is a central characteristic of sleep apnea syndrome (SAS), and it subjects cells in the body to repetitive apnea, chronic hypoxia, oxygen desaturation, and hypercapnia. Since SAS is linked to various serious cardiovascular complications, especially hypertension, many studies have been conducted to elucidate the mechanism of hypertension induced by SAS/IH. Hypertension in SAS is associated with numerous cardiovascular disorders. As hypertension is the most common complication of SAS, cell and animal models to study SAS/IH have developed and provided lots of hints for elucidating the molecular mechanisms of hypertension induced by IH. However, the detailed mechanisms are obscure and under investigation. This review outlines the molecular mechanisms of hypertension in IH, which include the regulation systems of reactive oxygen species (ROS) that activate the renin-angiotensin system (RAS) and catecholamine biosynthesis in the sympathetic nervous system, resulting in hypertension. And hypoxia-inducible factors (HIFs), Endotheline 1 (ET-1), and inflammatory factors are also mentioned. In addition, we will discuss the influences of SAS/IH in cardiovascular dysfunction and the relationship of microRNA (miRNA)s to regulate the key molecules in each mechanism, which has become more apparent in recent years. These findings provide insight into the pathogenesis of SAS and help in the development of future treatments.

Lasting mesothalamic dopamine imbalance and altered exploratory behavior in rats after a mild neonatal hypoxic event

Introduction

Adversities during the perinatal period can decrease oxygen supply to the fetal brain, leading to various hypoxic brain injuries, which can compromise the regularity of brain development in different aspects. To examine the catecholaminergic contribution to the link between an early-life hypoxic insult and adolescent behavioral aberrations, we used a previously established rat model of perinatal hypoxia but altered the hypobaric to normobaric conditions.

Methods

Exploratory and social behavior and learning abilities were tested in 70 rats of both sexes at adolescent age. Inherent vertical locomotion, sensory-motor functions and spatial learning abilities were explored in a subset of animals to clarify the background of altered exploratory behavior. Finally, the concentrations of dopamine (DA) and noradrenaline in midbrain and pons, and the relative expression of genes for DA receptors D1 and D2, and their down-stream targets (DA- and cAMP-regulated phosphoprotein, Mr 32 kDa, the regulatory subunit of protein kinase A, and inhibitor-5 of protein phosphatase 1) in the hippocampus and thalamus were investigated in 31 rats.

Results

A lesser extent of alterations in exploratory and cognitive aspects of behavior in the present study suggests that normobaric conditions mitigate the hypoxic injury compared to the one obtained under hypobaric conditions. Increased exploratory rearing was the most prominent consequence, with impaired spatial learning in the background. In affected rats, increased midbrain/pons DA content, as well as mRNA levels for DA receptors and their down-stream elements in the thalamus, but not the hippocampus, were found.

Conclusion

We can conclude that a mild hypoxic event induced long-lasting disbalances in mesothalamic DA signaling, contributing to the observed behavioral alterations. The thalamus was thereby indicated as another structure, besides the well-established striatum, involved in mediating hypoxic effects on behavior through DA signaling.

The involvement of the adrenergic system in feeding and eating disorders. A systematic review

BACKGROUND

Adrenergic dysregulation has been proposed as a possible underlying mechanism in feeding and eating disorders (FED). This review aims to synthesise the current evidence on the role of adrenergic dysregulation in the pathogenesis and management of FED.

METHODS

A systematic review was conducted in MEDLINE, Cochrane Library, and Clinicaltrials.gov. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was adopted. Preclinical, clinical, and pharmacological studies assessing the adrenergic system in FED were included.

RESULTS

Thirty-one out of 1415 recognised studies were included. Preclinically, studies on adrenaline's anorectic impact, receptor subtypes, and effects on hepatic function in rats show that catecholamine anorexia is primarily alpha-adrenergic, whereas beta-adrenergic anorexia can be obtained only after puberty, implying an impact of sexual hormones. Clinically, catecholamine levels may be higher in FED patients than in healthy controls (HC). Individuals with anorexia nervosa (AN) may show higher epinephrine-induced platelet aggregability response than HC. Pharmacological trials suggest that the alpha-2-adrenergic medication clonidine may not lower AN symptoms, but agents regulating the adrenaline-noradrenaline neurotransmission (bupropion, reboxetine, duloxetine, sibutramine) have been found to improve binge eating symptoms.

CONCLUSION

Adrenergic dysregulation may be involved in the pathophysiology of FED. More research is needed to comprehend underlying mechanisms and treatment implications.

Activity-dependent constraints on catecholamine signaling

Catecholamine signaling is thought to modulate cognition in an inverted-U relationship, but the mechanisms are unclear. We measured norepinephrine and dopamine release, postsynaptic calcium responses, and interactions between tonic and phasic firing modes under various stimuli and conditions. High tonic activity in vivo depleted catecholamine stores, desensitized postsynaptic responses, and decreased phasic transmission. Together, these findings provide a more complete understanding of the inverted-U relationship, offering insights into psychiatric disorders and neurodegenerative diseases with impaired catecholamine signaling.

Takotsubo cardiomyopathy following scorpion envenomation: a literature review

BACKGROUND

Takotsubo syndrome is comparable to microvascular acute coronary syndrome. It may partly share the same pathophysiology debated during scorpion envenomation (SE), with an adrenergic storm, without myocardial infarction due to the absence of coronary artery stenosis. Takotsubo cardiomyopathy can help to better understand the pathophysiology of cardiac involvement during scorpion envenomation. However, Takotsubo syndrome seems to be underestimated in the literature in patients suffering from cardiac failure following SE.

METHODS

In this review, we aimed to detail all described cases, the mechanism, and outcomes of scorpion envenomation complicated by Takotsubo cardiomyopathy. We used the PubMed database by using the following keywords in MeSH research: scorpion envenomation, Takotsubo cardiomyopathy, and Takotsubo syndrome.

RESULTS

The literature analysis showed the existence of only four cases of confirmed Takotsubo cardiomyopathy following severe SE. All four patients developed a transient reversible left ventricular systolic dysfunction in the absence of coronary artery disease, following a positive history of scorpion envenomation. A cardiac MRI was performed in all cases, showing a ballooning in the left ventricle associated with a left ventricular ejection fraction in all cases. All patients were improved under symptomatic treatment, and complete recovery of the wall motion was observed.

CONCLUSION

Takotsubo syndrome, although not often reported in the literature in severe SE, can represent an effective hypothesis explaining the pathophysiology of cardiac involvement during SE. In severe scorpion envenomation, multiple mechanisms exist and can explain the development of Takotsubo syndrome. Its management is based on oxygen, with invasive or non-invasive ventilator support in patients with respiratory failure and/or cardiogenic shock. Beta-blockers, mineralocorticoid receptor antagonists, and diuretics are usually used in Takotsubo syndrome. However, in severe scorpion envenomation, all reported cases of Takotsubo cardiomyopathy are associated with cardiogenic shock and acute pulmonary edema. As a consequence, we advise the use of Dobutamine since it has already been confirmed that cardiac dysfunction following scorpion envenomation improves well and safely under Dobutamine infusion.

Comparison of Cardiac Indices Using Two Different Concentrations of Topical Adrenaline during Endoscopic Transsphenoidal Pituitary Surgery: A Prospective Randomized Observational Study

Introduction  Adrenaline-soaked wicks are often employed to decongest nasal mucosa during transsphenoidal pituitary surgeries to ensure proper hemostasis and visibility of the operating field. Considerable debate exists regarding the optimum concentration of adrenaline that strikes a balance between hemostasis as well as the hemodynamic side effects of adrenaline. This study assessed cardiac indices like cardiac output and cardiac index using a FloTrac Vigileo cardiac output monitor to compare two different concentrations of adrenaline used for topical instillation. Materials and Methods  60 adult patients undergoing transsphenoidal pituitary surgery were randomly assigned to receive cotton wicks soaked in adrenaline solution (either 1:100,000 or 1:200,000) for nasal decongestion. Following a standardized anesthetic regime, a FloTrac Vigileo cardiac output monitor was attached with the invasive arterial line for precise monitoring and recording of cardiac indices (cardiac output and cardiac index). Additionally, quality of surgical field (as reported by the operating surgeon) blood loss, incidences of adverse hemodynamic events, and rescue drug usage were recorded. Results  No difference in cardiac outputs and cardiac indexes of the patients was observed during baseline to 55 minutes and at 80 minutes and onward, whereas difference rose to statistical significance at the time points of 60 minutes and 70 minutes ( p  < 0.05). Other parameters like stroke volume, stroke volume variation, and hemodynamic parameters were similar. Quality of the surgical fields (as reported by the surgeon), intraoperative bleeding, incidences of adverse effects, and frequency of rescue drugs usage were similar. Conclusion  Instillation of 1:100,000 dilution of adrenaline solution compared with 1:200,000 for nasal decongestion is associated with significant rise in cardiac output and cardiac index at 60 and 70 minutes of the surgery with similar blood loss and hemodynamic variables. Therefore, the lower concentration of adrenaline can be recommended for usage during transsphenoidal pituitary surgeries.

Dopamine alters phage morphology to exert an anti-infection effect

Antiviral drug development is important for human health, and the emergence of novel COVID-19 variants has seriously affected human lives and safety. A bacteriophage-a bacterial virus with a small and simple structure-is an ideal experimental candidate for studying the interactions between viruses and their hosts. In this study, the effects and mechanisms of catecholamines on phages were explored, and dopamine (DA) was found to have general and efficient anti-infection effects. A clear dose-dependent effect was observed when different phages were treated with DA, with higher DA concentrations exhibiting stronger anti-phage activity. The half maximal inhibitory concentration values of DA for vB-EcoS-IME167, T4 Phage, and VMY22 were determined as 0.26, 0.12, and 0.73 mg mL-1, respectively. The anti-phage effect of DA increased with treatment duration. In addition, the anti-infection activities of DA against vB-EcoS-IME167, T4 Phage, and VMY22 were increased by 105, 104, and 104 folds compared to that of the control. This ability of DA was observed only in phages and not in the host bacteria. Morphological changes of phages were observed under transmission electron microscopy following their treatment with DA, and considerable changes in adsorption were confirmed via quantitative reverse transcription polymerase chain reaction. These results suggest that the anti-phage effect of DA is primarily due to the destruction of the external structure of the phage. This study, to the best of our knowledge, is the first to report the universal anti-phage infection effect of dopamine, which provides novel information regarding DA and forms a basis for further research and development of antiviral drugs. Moreover, it provides a new perspective for the research about the defense and counter-defense of bacteria and bacteriophages.

Synthesis of 2D VO2 Nanosheets for the Dual Optical Sensor Method by Colorimetric and Fluorometric Sensing of Catecholamines

For the first time, we report a dual optical sensor method (DOSM) using novel 2D VO2 nanosheets to act as fluorometric and colorimetric sensors to perform quantitative analysis of epinephrine (EP) and dopamine (DA). The wide color spectrum of the 2D vanadium oxidation series and specifically metastable blue 2D VO2 nanosheets were used to develop a DOSM biosensor. DA and EP are the major catecholamines in the human body that play vital roles as neurotransmitters and stress-responsive hormones of the endocrine system, respectively. Accurate and selective detection of these biomolecules can assist in the diagnosis of many neuroendocrine system-related diseases. The newly synthesized 2D VO2 nanosheet sensor showed bluish-green fluorescence as the first-ever fluorescence from 2D VO2 nanosheets. This sensor showed dual-function sensing toward EP by a dominant color change and fluorescence quenching. It is capable of individually detecting and quantifying both EP and DA with high selectivity and sensitivity by using both colorimetry and fluorometry simultaneously, with the detection limits of 1.07 and 5.54 μM for colorimetric analysis, respectively, and 48.07 and 3.98 μM for fluorescence analysis, respectively. The DOSM sensor was directly applied to real urine samples and gained satisfactory recovery above 90% by means of spiked concentrations. This study has opened a new platform using the DOSM and the vanadium oxidation spectrum in a much more effective way for biosensing. The fluorescence capabilities of this metal oxide can be further applied to many sensor applications based on both fluorescence and colorimetric detection.

Biochemically Silent Pheochromocytoma in an Asymptomatic Patient With a Unilateral Lipid-Poor Adrenal Adenoma

In this case, a Caucasian woman was incidentally found to have a left adrenal gland incidentaloma a decade ago. Initial tests indicated a non-functional lipid-poor adenoma, but ongoing surveillance revealed irregularities in biochemical testing for pheochromocytoma. The patient was concurrently taking an SNRI, known to elevate biochemical markers artificially. Given the adenoma's growth and mild biochemical abnormalities, laparoscopic surgery was performed, and the tumor was found to be a 2.4 cm × 1.8 cm pheochromocytoma. Following the procedure, hormone levels normalized, and the patient experienced relief from symptoms. This case underscores the rarity of pheochromocytomas, emphasizing the importance of accurate diagnosis and effective management. Imaging techniques, notably computed tomography (CT) and magnetic resonance imaging (MRI), played a crucial role in localization, particularly through contrast-enhanced methods. Key characteristics like Hounsfield density, enhancement patterns, and washout behavior aided in distinguishing diverse adrenal masses. For cases where imaging had limitations, complementary techniques such as 23I-metaiodobenzylguanidine (MIBG) scintigraphy, specialized MR sequences, and GA-DOTATATE scans provided supplementary diagnostic insights, collectively contributing to a comprehensive clinical understanding. Despite advancements, challenges persist in differentiating specific adrenal tumors, highlighting the need for continued research and refined imaging methodologies.

Practical therapeutic approach in the management of diabetes mellitus secondary to Cushing's syndrome, acromegaly and neuroendocrine tumours

Cushing's syndrome, acromegaly and neuroendocrine disorders are characterized by an excess of counterregulatory hormones, able to induce insulin resistance and glucose metabolism disorders at variable degrees and requiring immediate treatment, until patients are ready to undergo surgery. This review focuses on the management of diabetes mellitus in endocrine disorders related to an excess of counterregulatory hormones. Currently, the landscape of approved agents for treatment of diabetes is dynamic and is mainly patient-centred and not glycaemia-centred. In addition, personalized medicine is more and more required to provide a precise approach to the patient's disease. For this reason, we aimed to define a practical therapeutic algorithm for management of diabetes mellitus in patients with glucagonoma, pheochromocytoma, Cushing's syndrome and acromegaly, based on our practical experience and on the physiopathology of the specific endocrine disease taken into account. This document is addressed to all specialists who approach patients with diabetes mellitus secondary to endocrine disorders characterized by an excess of counterregulatory hormones, in order to take better care of these patients. Care and control of diabetes mellitus should be one of the primary goals in patients with an excess of counterregulatory hormones requiring immediate and aggressive treatment.

Catecholamine Variations in Pediatric Gastrointestinal Disorders and Their Neuropsychiatric Expression

The interplay between the central nervous system and the intestinal environment hinges on neural, hormonal, immune, and metabolic reactions. Over decades, significant effort has gone into exploring the link between the digestive system and the brain. The primary objective of this study is to assess catecholamine levels in children with neuropsychiatric disorders. We aim to examine how these levels impact the mental and physical wellbeing of these children, with a specific focus on psychoemotional symptoms and cognitive performance. Our research seeks to identify the significance of modifying neurotransmitter levels in pediatric medical interventions, ultimately striving to reduce mental health risks and enhance children's future development. A total of 135 individuals were chosen to partake, and they engaged in regular monthly consultations according to established study protocols. Clinical evaluations were conducted in a medical environment, encompassing the observation of constipation, diarrhea, and additional gastrointestinal anomalies not confined to constipation or diarrhea. This entailed the assessment of neurotransmitter imbalances, with a specific focus on dopamine, adrenaline, noradrenaline, and the noradrenaline/adrenaline ratio. Gastrointestinal disorders are indicative of imbalances in catecholamines, with lower gastrointestinal problems being correlated with such imbalances. In subjects with psychiatric disorders, a more pronounced dopamine and noradrenaline/adrenaline ratio was observed, while elevated adrenaline levels were associated with psychoanxiety disorders.

Catecholamines Promote Ovarian Cancer Progression through Secretion of CXC-Chemokines

Considerable evidence has accumulated in the last decade supporting the notion that chronic stress is closely related to the growth, metastasis, and angiogenesis of ovarian cancer. In this study, we analyzed the conditioned media in SKOV3 ovarian cancer cell lines treated with catecholamines to identify secreted proteins responding to chronic stress. Here, we observed that epinephrine and norepinephrine enhanced the secretion and mRNA expression of CXC-chemokines (CXCL1, 2, 3, and 8). Neutralizing antibodies to CXCL8 and CXCL8 receptor (CXCR2) inhibitors significantly reduced catecholamine-mediated invasion of SKOV3 cells. Finally, we found that the concentration of CXCL1 and CXCL8 in the plasma of ovarian cancer patients increased with stage progression. Taken together, these findings suggest that stress-related catecholamines may influence ovarian cancer progression through the secretion of CXC-chemokines.