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Birds (Aves) display high metabolic rates and oxygen consumption relative to mammals, increasing reactive oxygen species (ROS) formation. Although excess ROS reduces lifespan by causing extensive cellular dysfunction and damage, birds are remarkably long-lived. We address this paradox by identifying the constitutive activation of the NRF2 master antioxidant response in Neoaves (~95% of bird species), providing an adaptive mechanism capable of counterbalancing high ROS levels. We demonstrate that a KEAP1 mutation in the Neoavian ancestor disrupted the repression of NRF2 by KEAP1, leading to constitutive NRF2 activity and decreased oxidative stress in wild Neoaves tissues and cells. Our evidence suggests this ancient mutation induced a compensatory program in NRF2-target genes with functions beyond redox regulation—including feather development—while enabling significant metabolic rate increases that avoid trade-offs with lifespan. The strategy of NRF2 activation sought by intense clinical investigation therefore appears to have also unlocked a massively successful evolutionary trajectory. [ABSTRACT FROM AUTHOR]

All-trans retinoic acid (ATRA) is the only clinically useful differentiating agent, being used in the treatment of acute promyelocytic leukemia (APL). The use of ATRA in other types of acute myelogenous leukemia (AML) calls for the identification of novel strategies aimed at increasing its therapeutic activity. Here, we provide evidence that pharmacological inhibition of the mitogen-activated protein kinase, p38α, or silencing of the corresponding gene sensitizes APL and AML cell lines, as well as primary cultures of AML blasts to the anti-proliferative and cyto-differentiating activity of ATRA and synthetic retinoids. P38α inhibits ligand-dependent transactivation of the nuclear retinoic acid receptor, RARα, and the derived chimeric protein expressed in the majority of APL cases, PML-RARα. Inhibition is the consequence of ligand-independent binding of p38α, which results in stabilization of RARα and PML-RARα via blockade of their constitutive degradation by the proteasome. The inhibitory effect requires a catalytically active p38α and direct physical interaction with RARα and PML-RARα. Ser-369 in the E-region of RARα is essential for the binding of p38α and the ensuing functional effects on the activity of the receptor. [ABSTRACT FROM AUTHOR]

The high cardiovascular risk of HIV infected (HIV+) patients is still partly unexplained. We aimed to evaluate if HIV infection and highly active antiretroviral therapy (HAART) are linked per se to left ventricular (LV) remodelling, independently of blood pressure (BP) values. We enrolled 4 groups of patients matched by gender, age, body mass index and smoking habit: 30 HIV+ hypertensives, 30 HIV+ normotensives, 30 not-infected (HIV−) hypertensives and 30 HIV− normotensives. HIV+ patients were on chronic HAART. Hypertension was newly diagnosed (6 months) and never treated. Each patient underwent blood tests, 24-h BP monitoring and LV echocardiogram. The 4 groups had similar fasting glucose and cholesterol; triglycerides, HOMA index and prevalence of metabolic syndrome were higher in the HIV+ groups. Despite similar 24-h BP values, HIV+ hypertensives had greater LV mass and higher prevalence of preclinical diastolic dysfunction than HIV− hypertensives. Compared to HIV− normotensives, HIV+ normotensives had similar 24-h BP values, but greater LV mass and lower LV diastolic indices, similar to HIV− hypertensives, whose 24-h BP values were higher. Asymptomatic HIV infection and chronic HAART are associated with myocardial hypertrophy and preclinical diastolic dysfunction, independently of BP values. [ABSTRACT FROM AUTHOR]

The aim of this study was to carry out two different dose estimation approaches in patients with non-Hodgkin’s lymphoma (NHL) treated with a myeloablative amount of 90Y-labelled ibritumomab tiuxetan (Zevalin®) in an open-label dose escalation study. Twenty-seven patients with relapsed/refractory or de novo high-risk NHL receiving one myeloablative dose of 90Y-ibritumomab tiuxetan followed by tandem stem cell reinfusion were evaluated for dose estimate. The injected activity was 30 MBq/kg in 12 patients and 45 MBq/kg in 15 patients. Dose estimation was performed 1 week prior to 90Y-ibritumomab tiuxetan by injection of 111In-ibritumomab tiuxetan (median activity: 200 MBq). The absorbed dose (D) and the biologically effective dose (BED) were calculated. The absorbed doses per unit activity (Gy/GBq) were [median (range)]: heart wall 4.6 (2.5–9.7), kidneys 5.1 (2.8–10.5), liver 6.1 (3.9–10.4), lungs 2.9 (1.5–6.8), red marrow 1.0 (0.5–1.7), spleen 7.0 (1.5–14.4) and testes 4.9 (2.9–16.7). The absorbed dose (Gy) for the 15 patients treated with 45 MBq/kg were: heart wall 17.0 (8.7–25.4), kidneys 17.1 (7.9–22.4), liver 20.8 (15.4–28.3), lungs 8.1 (5.4–11.4), red marrow 3.1 (2.0–4.0), spleen 26.2 (17.0–35.6) and testes 17.3 (9.0–28.4). At the highest activities the acute haematological toxicity was mild or moderate and of very short duration, and it was independent of the red marrow absorbed dose. No secondary malignancy or treatment-related myelodysplastic syndrome was observed. No non-haematological toxicity (liver, kidney, lung) was observed during a follow-up period of 24–48 months. The use of 45 MBq/kg of 90Y-ibritumomab tiuxetan in association with stem cell autografting resulted in patients being free of toxicity in non-haematological organs. These clinical findings were in complete agreement with our dose estimations, considering both organ doses and BED values. [ABSTRACT FROM AUTHOR]

Endocytosis of cell surface receptors is an important regulatory event in signal transduction. The transforming growth factor β (TGF-β) superfamily signals to the Smad pathway through heteromeric Ser-Thr kinase receptors that are rapidly internalized and then downregulated in a ubiquitin-dependent manner. Here we demonstrate that TGF-β receptors internalize into both caveolin- and EEA1-positive vesicles and reside in both lipid raft and non-raft membrane domains. Clathrin-dependent internalization into the EEA1-positive endosome, where the Smad2 anchor SARA is enriched, promotes TGF-β signalling. In contrast, the lipid raft-caveolar internalization pathway contains the Smad7-Smurf2 bound receptor and is required for rapid receptor turnover. Thus, segregation of TGF-β receptors into distinct endocytic compartments regulates Smad activation and receptor turnover. [ABSTRACT FROM AUTHOR]

In the NB4 model of acute promyelocytic leukemia (APL), ATRA, 9-cis retinoic acid (9-cis RA), the pan-RAR and RARαselective agonists, TTNPB and AM580, induce growth inhibition, granulocytic differentiation and apoptosis. By contrast, two RXR agonists, a RARβ agonist and an anti-AP1 retinoid have very limited activity, ATRA- and AM580dependent effects are completely inhibited by RAR antagonistic blockade, while 9-cis RA-induced cell-growth-inhibition and apoptosis are equally inhibited by RAR and RXR antagonists. ATRA, 9-cis RA and AM580 cause upregulation of the mRNAs coding for pro-caspase-1, -7, -8, and -9, which, however, results in increased synthesis of only pro-caspase-1 and -7 proteins. These phenomena are associated with activation of pro-caspase-6, -7 and -8, cytochrome c release from the mitochondria, inversion of Bcl-2/Bax ratio and degradation of PML-RARα. Caspase activation is fundamental for retinoid-induced apoptosis, which is suppressed by the caspase-inhibitor z-VAD. [ABSTRACT FROM AUTHOR]

To reduce the sequelae from CNS irradiation (RT), 16 children younger than 3 years with medulloblastoma-PNET (13 cases) and ependymoma (3 cases) were treated between 1987–1993 according to different postsurgical chemotherapy (CT) programs. None of these patients presented with metastases. Eleven patients were rendered disease-free by surgery, while 5 had residual tumor. Adjuvant therapy depended on patients’ age, postsurgical status and parents’ consent to radiotherapy (RT). Nine of the 16 infants remained alive in continuous complete remission from the first neoplasm (median follow-up 7 years). Three of them had been treated with CT alone and 6 with combined CT+RT (posterior fossa 4, whole CNS 2). Seven patients relapsed a median of 13 months after diagnosis, and all 7 of them died of their disease. Despite the omission of RT in 6 of the 16 patients and administration of only focal RT in 8 of the 16, the outcome of this series was satisfactory. Local failure (in 5/7 patients) was the major problem, despite the high dose of RT used in 2 of these 5. In 4 of 6 evaluable children school performance was satisfactory. One child in whom the entire CNS was irradiated developed glioblastoma multiforme 120 months after the first diagnosis of medulloblastoma. [ABSTRACT FROM AUTHOR]

Acquired arachnoid cysts of the spinal cord are uncommon causes of spinal cord compression in the pediatric group. Meningitis, trauma and hemorrhage are considered to be causative or contributing factors. Interestingly, no spinal arachnoid cysts have been reported in patients after subarachnoid hemorrhage or meningitis, conditions expected to cause arachnoid scarring. We describe a child of 1 year and 10 months with thoracic spine trauma with crural paraplegia and anesthesia at level T5 submitted to serial magnetic resonance imagery at 5 days and 18 months, after trauma showing evolution from subarachnoid hemorrhage and adhesions of the arachnoid space to a posterior hyptertensive thoracic intradural arachnoid cyst. [ABSTRACT FROM AUTHOR]

Dietary needs during adolescence lack specific definitions, and most evidence is derived from indirect indications. The data on dietary needs for energy and proteins are mainly extrapolated from subjects in other age-classes. Lipids and carbohydrates are being progressively considered for preventive purposes since the qualitative distribution of saturated and unsaturated fats and slowly and rapidly absorbed carbohydrates, respectively, seems to be associated with metabolic index predictors of degenerative disorders in later stages of life. The recent results of multicentric autoptic studies in young people from the US indicate that the lipoprotein status of the second decade of life is associated with the first raised arterial lesions in the third decade. The evidence of these links needs further confirmation from ongoing surveys. We must recognize that adolescence is a critical period of life, and food fads may deeply change the dietary habits acquired within the familiar group. As nutritionists, we may suggest that all adolescents should be supplied with nutritional support in terms of education, maybe at school, to improve their knowledge of nutrition. Descriptors: adolescence; dietary habits; dietary recommendations; prevention European Journal of Clinical Nutrition (2000) 54, Suppl 1, S7–S10. [ABSTRACT FROM AUTHOR]