Olmesartan-Induced Enteropathy: When the Treatment of One Disease Causes Another

Olmesartan is an angiotensin II receptor antagonist used for the management of hypertension. This drug can lead to an enteropathy that clinically and histologically resembles coeliac disease. Symptoms may appear months or years after the introduction of the drug and usually resolve after discontinuation. The authors present a case of an 86-year-old woman with hypertension who was treated with olmesartan for 10 years. She presented to the emergency department with diarrhoea after three months of development and weight loss. The aetiological study that was conducted excluded infectious, inflammatory, endocrinological, and neoplastic causes. The pathological anatomy of the duodenal biopsy was suggestive of coeliac disease, but the serology was not compatible. The patient presented complete remission of the condition with the suspension of the drug and subsequent recrudescence when, by self-initiation, she resumed olmesartan. This case study aims to alert readers of a rare cause of enteropathy with a clinical manifestation that mimics coeliac disease. Olmesartan-induced enteropathy seems to be a diagnosis of exclusion and should be considered in patients chronically medicated with olmesartan.

Chronic Lithium Intoxication: A Challenging Diagnosis

Lithium has been used in clinical practice since the 1970s. This medication is commonly used to treat and prevent bipolar disorder, but it has a narrow therapeutic index, making toxicity a frequent occurrence. Chronic lithium intoxication can arise due to progressive accumulation, particularly in contexts of dehydration. The effects of chronic lithium intoxication on the nervous, renal, and cardiac systems, as well as on the thyroid and parathyroid glands, are well documented in the literature. The authors present the case of a 66-year-old woman with schizoaffective psychosis and chronic kidney disease, admitted due to altered mental status and dysarthria. Notwithstanding an earlier clinical recommendation to cease lithium administration more than a year ago, the patient continued its usage, culminating in neurological, cardiac, renal, and endocrine manifestations. Although the diagnosis was delayed, her clinical progression was favorable, obviating the need for renal replacement therapy. This case highlights the importance of a detailed medical history and the diagnostic challenges in clinical practice. The use of this drug without proper monitoring can lead to multisystem dysfunction.

From Suspected COVID-19 to Anti-synthetase Syndrome: A Diagnostic Challenge in the Pandemic Era

Anti-synthetase syndrome (ASS), a rare immunomediated disease, is characterized by multiple signs and symptoms. Not all patients develop the entire clinical spectrum of the syndrome, as it often varies depending on the involved antibodies. In this case report, a 53-year-old non-smoking woman had complaints of fatigue and dyspnea on exertion for five weeks. The outpatient study revealed creatine kinase (CK) 351U/L, ANAs+, anti-SSa+, normal echocardiogram, and a chest X-ray suggesting imaging suspicion of SARS-CoV-2 pneumonia. Referred to the emergency department, she was hospitalized for bilateral interstitial pneumonia without respiratory failure. Three SARS-CoV-2 polymerase chain reaction tests were negative. She underwent a five-day course of dexamethasone 6mg due to suspected coronavirus disease 2019 (COVID-19) sequelae with favorable progress. About a month later, she experienced fatigue, exertional intolerance, morning cough, and Raynaud's phenomenon episodes. Anti-SARS-CoV-2 antibodies were negative, and a follow-up chest CT showed bilateral organizing pneumonia. Bronchofibroscopy and bronchoalveolar lavage with cytology suggestive of inflammatory appearance, predominantly CD8+ lymphocytes, were performed. Subsequently, positive results for anti-OJ antibodies were obtained. A diagnosis of ASS was established, and prednisolone was initiated at 60mg/day with a tapering regimen, resulting in clinical and radiological improvement. Additional therapy with azathioprine was proposed. This case is presented due to highly suggestive COVID-19 imaging changes, emphasizing the importance of a high suspicion of ASS, despite nearly exclusive pulmonary involvement, with only one isolated elevated CK value and no musculoskeletal complaints. It is also noteworthy for the association with anti-OJ antibodies, rarely identified, often presenting interstitial lung disease as an isolated manifestation.

Dipyrone (Metamizole)-Induced Stevens-Johnson Syndrome

Stevens-Johnson Syndrome (SJS), a severe mucocutaneous hypersensitivity reaction primarily triggered by drugs, poses a low-incidence, high-mortality challenge. This report explores its clinical nuances and emphasizes supportive care as the mainstay of treatment. A 74-year-old female, burdened with a complex medical history, presented with a non-pruritic macular rash escalating to skin and oral mucosal involvement. A recent introduction of dipyrone (metamizole) implicated drug-induced SJS. Histopathological confirmation guided treatment involving supportive care, corticosteroids, and wound care, resulting in clinical improvement. The case underscores the significance of histopathological confirmation and thorough medication history in navigating SJS complexities, especially in patients with comorbidities like connective tissue disease. A successful multidisciplinary approach and the decision for post-discharge monitoring highlight the intricate management challenges. This case illuminates the intricate interplay of medication-induced hypersensitivity, comorbidities, and management challenges in SJS. Optimal outcomes require prompt diagnosis, trigger identification, and a multidisciplinary treatment approach, emphasizing ongoing research and clinical vigilance.

Adenosine A2A receptor regulation of microglia morphological remodeling-gender bias in physiology and in a model of chronic anxiety

Developmental risk factors, such as the exposure to stress or high levels of glucocorticoids (GCs), may contribute to the pathogenesis of anxiety disorders. The immunomodulatory role of GCs and the immunological fingerprint found in animals prenatally exposed to GCs point towards an interplay between the immune and the nervous systems in the etiology of these disorders. Microglia are immune cells of the brain, responsive to GCs and morphologically altered in stress-related disorders. These cells are regulated by adenosine A_2A receptors, which are also involved in the pathophysiology of anxiety. We now compare animal behavior and microglia morphology in males and females prenatally exposed to the GC dexamethasone. We report that prenatal exposure to dexamethasone is associated with a gender-specific remodeling of microglial cell processes in the prefrontal cortex: males show a hyper-ramification and increased length whereas females exhibit a decrease in the number and in the length of microglia processes. Microglial cells re-organization responded in a gender-specific manner to the chronic treatment with a selective adenosine A_2A receptor antagonist, which was able to ameliorate microglial processes alterations and anxiety behavior in males, but not in females.

Presynaptic adenosine A2A receptors dampen cannabinoid CB1 receptor-mediated inhibition of corticostriatal glutamatergic transmission

BACKGROUND AND PURPOSE

Both cannabinoid CB1 and adenosine A2A receptors (CB1 receptors and A2A receptors) control synaptic transmission at corticostriatal synapses, with great therapeutic importance for neurological and psychiatric disorders. A postsynaptic CB1 -A2A receptor interaction has already been elucidated, but the presynaptic A2A receptor-mediated control of presynaptic neuromodulation by CB1 receptors remains to be defined. Because the corticostriatal terminals provide the major input to the basal ganglia, understanding the interactive nature of converging neuromodulation on them will provide us with novel powerful tools to understand the physiology of corticostriatal synaptic transmission and interpret changes associated with pathological conditions.

EXPERIMENTAL APPROACH

Pharmacological manipulation of CB1 and A2A receptors was carried out in brain nerve terminals isolated from rats and mice, using flow synaptometry, immunoprecipitation, radioligand binding, ATP and glutamate release measurement. Whole-cell patch-clamp recordings were made in horizontal corticostriatal slices.

KEY RESULTS

Flow synaptometry showed that A2A receptors were extensively co-localized with CB1 receptor-immunopositive corticostriatal terminals and A2A receptors co-immunoprecipitated CB1 receptors in these purified terminals. A2A receptor activation decreased CB1 receptor radioligand binding and decreased the CB1 receptor-mediated inhibition of high-K(+) -evoked glutamate release in corticostriatal terminals. Accordingly, A2A receptor activation prevented CB1 receptor-mediated paired-pulse facilitation and attenuated the CB1 receptor-mediated inhibition of synaptic transmission in glutamatergic synapses of corticostriatal slices.

CONCLUSIONS AND IMPLICATIONS

Activation of presynaptic A2A receptors dampened CB1 receptor-mediated inhibition of corticostriatal terminals. This constitutes a thus far unrecognized mechanism to modulate the potent CB1 receptor-mediated presynaptic inhibition, allowing frequency-dependent enhancement of synaptic efficacy at corticostriatal synapses.

Effects of melatonin on DNA damage induced by cyclophosphamide in rats

The antioxidant and free radical scavenger properties of melatonin have been well described in the literature. In this study, our objective was to determine the protective effect of the pineal gland hormone against the DNA damage induced by cyclophosphamide (CP), an anti-tumor agent that is widely applied in clinical practice. DNA damage was induced in rats by a single intraperitoneal injection of CP (20 or 50 mg/kg). Animals received melatonin during the dark period for 15 days (1 mg/kg in the drinking water). Rat bone marrow cells were used for the determination of chromosomal aberrations and of formamidopyrimidine DNA glycosylase enzyme (Fpg)-sensitive sites by the comet technique and of Xpf mRNA expression by qRT-PCR. The number (mean ± SE) of chromosomal aberrations in pinealectomized (PINX) animals treated with melatonin and CP (2.50 ± 0.50/100 cells) was lower than that obtained for PINX animals injected with CP (12 ± 1.8/100 cells), thus showing a reduction of 85.8% in the number of chromosomal aberrations. This melatonin-mediated protection was also observed when oxidative lesions were analyzed by the Fpg-sensitive assay, both 24 and 48 h after CP administration. The expression of Xpf mRNA, which is involved in the DNA nucleotide excision repair machinery, was up-regulated by melatonin. The results indicate that melatonin is able to protect bone marrow cells by completely blocking CP-induced chromosome aberrations. Therefore, melatonin administration could be an alternative and effective treatment during chemotherapy.