480 research outputs found
“Bottled” Spiro-Doubly Aromatic Trinuclear [Pd2Ru]+ Complexes
Following an ongoing interest in the study of transition metal complexes with exotic bonding networks, we report herein the synthesis of a family of heterobimetallic triangular clusters involving Ru and Pd atoms. These are the first examples of trinuclear complexes combining these nuclei. Structural and bonding analyses revealed both analogies and unexpected differences for these [Pd2Ru]+ complexes compared to their parent [Pd3]+ peers. Noticeably, participation of the Ru atom in the π-aromaticity of the coordinated benzene ring makes the synthesized compound the second reported example of ‘bottled’ double aromaticity. This can also be referred to as spiroaromaticity due to the participation of Ru in two aromatic systems at a time. Moreover, the [Pd2Ru]+ kernel exhibits unprecedented orbital overlap of Ru dz2 AO and two Pd dxy or dx2−y2 AOs. The present findings reveal the possibility of synthesizing stable clusters with delocalized metal–metal bonding from the combination of non-adjacent elements of the periodic table which has not been reported previously
Counteracting the Common Shwachman–Diamond Syndrome-Causing SBDS c.258+2T>C Mutation by RNA Therapeutics and Base/Prime Editing
Shwachman-Diamond syndrome (SDS) represents one of the most common inherited bone marrow failure syndromes and is mainly caused by SBDS gene mutations. Only supportive treatments are available, with hematopoietic cell transplantation required when marrow failure occurs. Among all causative mutations, the SBDS c.258+2T>C variant at the 5 ' splice site (ss) of exon 2 is one of the most frequent. Here, we investigated the molecular mechanisms underlying aberrant SBDS splicing and showed that SBDS exon 2 is dense in splicing regulatory elements and cryptic splice sites, complicating proper 5 ' ss selection. Studies ex vivo and in vitro demonstrated that the mutation alters splicing, but it is also compatible with tiny amounts of correct transcripts, which would explain the survival of SDS patients. Moreover, for the first time for SDS, we explored a panel of correction approaches at the RNA and DNA levels and provided experimental evidence that the mutation effect can be partially counteracted by engineered U1snRNA, trans-splicing, and base/prime editors, ultimately leading to correctly spliced transcripts (from barely detectable to 2.5-5.5%). Among them, we propose DNA editors that, by stably reverting the mutation and potentially conferring positive selection to bone-marrow cells, could lead to the development of an innovative SDS therapy
Retinoid metabolism and mode of action.
Vitamin A and its derivaties (retinoids) are necessary for the maintenance of normal phenotypic expression. An attempt at understanding the biochemical role of vitamin A had led to the demonstration of a new pathway for retinol. In this pathway, vitamin A is phosphorylated to retinylphosphate (RP), which is then glycosylated to retinylphosphatemannose (MRP). These two derivatives have been found in a variety of tissues in vivo and in vitro and appear to be ubiquitous components of cellular membranes. The suggestion has been made that MRP may mediate specific cellular interactions by functioning as a lipid intermediate in the biosynthesis of specific glycoconjugates. A study on spontaneously-transformed mouse fibroblasts (Balb/c 3T12-3 cells) has shown that retinoids are active in increasing the adhesive properties of these cells as measured in an EDTA-mediated detachment assay. Various retinoids were tested for their activity in the adhesion test, and this activity was found to correlate well with their biological activity in maintaining the expression of normal epithelial differentiation in other systems. Retinoic acid, 5,6-epoxyretinol, and 5,6-epoxyretinoic acid were the most active compounds. Retinoids without biological activity in other systems were also inactive in inducihg adhesive properties of 3T12-3 cells. Among these were the synthetic derivatives of retinol, anhydroretinol, and 4,5-monoeneperhydroretinol, and the phenyl derivative of retinoic acid. Beta-Ionone, abscisic acid, and juvenile hormone, which are devoid of vitamin A activity in other systems, were also inactive in this system. Retinoid-induced changes in cell surface proteins were investigated but no difference in 125I-fibronectin (MW 220,000) was detectable between retinoid-treated and untreated cells. However, these cells synthesized retinylphosphatemannose and the incorporation of 2-3H-mannose into a specific glycoprotein (gp 180) was found to be enhanced specifically by retinoid treatment. Investigations of the involvement of gp 180 in adhesion are in progress
Somatic mutations of thymic epithelial tumors with myasthenia gravis
BackgroundThymic epithelial tumors are rare malignant neoplasms that are frequently associated with paraneoplastic syndromes, especially myasthenia gravis. GTF2I is an oncogene mutated in a subgroup of thymomas that is reputed to drive their growth. However, for GTF2I wild-type tumors, the relevant mutations remain to be identified.MethodsWe performed a meta-analysis and identified 4,208 mutations in 339 patients. We defined a panel of 63 genes frequently mutated in thymic epithelial tumors, which we used to design a custom assay for next-generation sequencing. We sequenced tumor DNA from 67 thymomas of patients with myasthenia gravis who underwent resection in our institution.ResultsAmong the 67 thymomas, there were 238 mutations, 83 of which were in coding sequences. There were 14 GTF2I mutations in 6 A, 5 AB, 2 B2 thymomas, and one in a thymoma with unspecified histology. No other oncogenes showed recurrent mutations, while sixteen tumor suppressor genes were predicted to be inactivated. Even with a dedicated assay for the identification of specific somatic mutations in thymic epithelial tumors, only GTF2I mutations were found to be significantly recurrent.ConclusionOur evaluation provides insights into the mutational landscape of thymic epithelial tumors, identifies recurrent mutations in different histotypes, and describes the design and implementation of a custom panel for targeted resequencing. These findings contribute to a better understanding of the genetic basis of thymic epithelial tumors and may have implications for future research and treatment strategies
Influence of habitual dairy food intake on LDL cholesterol in a population-based cohort
Background: Cholesterol has a pivotal role in human physiology, exerting both structural and functional activity. However, higher blood cholesterol levels, especially low-density lipopro-tein cholesterol (LDL-C), are a major cardiovascular risk factor. Therefore, special attention has been given to the effect of dietary factors in influencing LDL-C blood levels. In particular, much research has focused on dairy products, since they are a main component of different dietary patterns world-wide. A large body of evidence did not support the hypothesis that dairy products significantly increase circulating LDL-C, but no definitive data are available. Hence, we aimed to assess the rela-tionships among LDL-C, habitual dairy food intake and anthropometric variables in a cohort representative of the general population in a Mediterranean area. Methods: We evaluated 802 healthy adults included in the ABCD_2 (Alimentazione, Benessere Cardiovascolare e Diabete) study (ISRCTN15840340), a longitudinal observational single-center study of a cohort representative of the general population of Palermo, Sicily. The habitual intake of dairy products was assessed with a validated food frequency questionnaire, and LDL-C serum levels and several anthropometric pa-rameters were measured. Results: The group with high LDL-C serum concentrations (≥130 vs. <130 mg/dL) exhibited higher age, body mass index (BMI), waist-to-hip ratio (WHR), body fat percent-age, systolic and diastolic blood pressure, carotid intima-media thickness and glycated hemoglobin. The habitual diet was not different between the groups in terms of macronutrient, cholesterol, egg and dairy food intake, with the exception of the weekly number of portions of milk (higher in the low LDL-C group vs. the high LDL-C group) and ricotta cheese (higher in the high LDL-C group vs. the LDL-C group). No significant correlation was found between LDL-C blood levels and the habitual intake of dairy products or the dietary intake of cholesterol and fats. The multivariate regression analyses (R2 = 0.94) showed that LDL-C blood levels were significantly associated with the habitual intake of milk (p < 0.005) and ricotta cheese (p < 0.001) and with BMI (p < 0.001). Conclusion: Our study reported that total dairy food consumption was not correlated with LDL-C blood levels. However, multivariate analyses showed an inverse association between serum LDL-C and milk intake as well as a positive association between ricotta cheese intake and LDL-C concentrations. More studies are needed to better characterize the relationship between dairy products and circulating LDL-C
Microencapsulación mediante secado por aspersión: efecto sobre la estabilidad oxidativa de los aceites de Chía (Salvia hispanica L.) y nuez (Juglans regia L.)
Evaluar la estabilidad oxidativa del AC y del AN (con y sin el agregado de ER) microencapsulados en condiciones de almacenamiento prolongado.http://www.fcq.unc.edu.ar/documentos/Libro_resumenes_JP6-Final.pdfFil: Curti, María I. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; Argentina.Fil: Martinez, Marcela L. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Martinez, Marcela L. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Ciencia y Tecnología de los Alimentos; Argentina.Fil: Roccia, Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; Argentina.Fil: LLabot, Juan M. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica.Fil: Maestri, Damián M. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Maestri, Damián M. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Ciencia y Tecnología de los Alimentos; Argentina.Fil: Ribotta, Pablo D. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; Argentina.Otras Ciencias Química
Italian Association of Sleep Medicine (AIMS) position statement and guideline on the treatment of menopausal sleep disorders
Insomnia, vasomotor symptoms (VMS) and depression often co-occur after the menopause, with consequent health problems and reductions in quality of life. The aim of this position statement is to provide evidence-based advice on the management of postmenopausal sleep disorders derived from a systematic review of the literature. The latter yielded results on VMS, insomnia, circadian rhythm disorders, obstructive sleep apnea (OSA) and restless leg syndrome (RLS). Overall, the studies show that menopausal hormone therapy (MHT) improves VMS, insomnia, and mood. Several antidepressants can improve insomnia, either on their own or in association with MHT; these include selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Long-term benefits for postmenopausal insomnia may also be achieved with non-drug strategies such as cognitive behavioral therapy (CBT) and aerobic exercise. Continuous positive airway pressure (CPAP) and mandibular advancement devices (MADs) both reduce blood pressure and cortisol levels in postmenopausal women suffering from OSA. However, the data regarding MHT on postmenopausal restless legs syndrome are conflicting
Female heterozygotes for the hypomorphic R40H mutation can have ornithine transcarbamylase deficiency and present in early adolescence: a case report and review of the literature
<p>Abstract</p> <p>Introduction</p> <p>Ornithine transcarbamylase deficiency is the most common hereditary urea cycle defect. It is inherited in an X-linked manner and classically presents in neonates with encephalopathy and hyperammonemia in males. Females and males with hypomorphic mutations present later, sometimes in adulthood, with episodes that are frequently fatal.</p> <p>Case presentation</p> <p>A 13-year-old Caucasian girl presented with progressive encephalopathy, hyperammonemic coma and lactic acidosis. She had a history of intermittent regular episodes of nausea and vomiting from seven years of age, previously diagnosed as abdominal migraines. At presentation she was hyperammonemic (ammonia 477 μmol/L) with no other biochemical indicators of hepatic dysfunction or damage and had grossly elevated urinary orotate (orotate/creatinine ratio 1.866 μmol/mmol creatinine, reference range <500 μmol/mmol creatinine) highly suggestive of ornithine transcarbamylase deficiency. She was treated with intravenous sodium benzoate and arginine and made a rapid full recovery. She was discharged on a protein-restricted diet. She has not required ongoing treatment with arginine, and baseline ammonia and serum amino acid concentrations are within normal ranges. She has had one further episode of hyperammonemia associated with intercurrent infection after one year of follow up. An R40H (c.119G>A) mutation was identified in the ornithine transcarbamylase gene (<it>OTC</it>) in our patient confirming the first symptomatic female shown heterozygous for the R40H mutation. A review of the literature and correspondence with authors of patients with the R40H mutation identified one other symptomatic female patient who died of hyperammonemic coma in her late teens.</p> <p>Conclusions</p> <p>This report expands the clinical spectrum of presentation of ornithine transcarbamylase deficiency to female heterozygotes for the hypomorphic R40H <it>OTC </it>mutation. Although this mutation is usually associated with a mild phenotype, females with this mutation can present with acute decompensation, which can be fatal. Ornithine transcarbamylase deficiency should be considered in the differential diagnosis of unexplained acute confusion, even without a suggestive family history.</p
- …