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Background: In man two mitochondrial aspartate/glutamate carrier (AGC) isoforms, known as aralar and citrin, are required to accomplish several metabolic pathways. In order to fill the existing gap of knowledge in Drosophila melanogaster, we have studied aralar1 gene, orthologue of human AGC-encoding genes in this organism., Methods: The blastp algorithm and the "reciprocal best hit" approach have been used to identify the human orthologue of AGCs in Drosophilidae and non-Drosophilidae. Aralar1 proteins have been overexpressed in Escherichia coli and functionally reconstituted into liposomes for transport assays., Results: The transcriptional organization of aralar1 comprises six isoforms, three constitutively expressed (aralar1-RA, RD and RF), and the remaining three distributed during the development or in different tissues (aralar1-RB, RC and RE). Aralar1-PA and Aralar1-PE, representative of all isoforms, have been biochemically characterized. Recombinant Aralar1-PA and Aralar1-PE proteins share similar efficiency to exchange glutamate against aspartate, and same substrate affinities than the human isoforms. Interestingly, although Aralar1-PA and Aralar1-PE diverge only in their EF-hand 8, they greatly differ in their specific activities and substrate specificity., Conclusions: The tight regulation of aralar1 transcripts expression and the high request of aspartate and glutamate during early embryogenesis suggest a crucial role of Aralar1 in this Drosophila developmental stage. Furthermore, biochemical characterization and calcium sensitivity have identified Aralar1-PA and Aralar1-PE as the human aralar and citrin counterparts, respectively., General Significance: The functional characterization of the fruit fly mitochondrial AGC transporter represents a crucial step toward a complete understanding of the metabolic events acting during early embryogenesis., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: The introduction of multislice computed tomography (MSCT) in 1998 has led to a considerable boost of CT angiography. Four-row MSCT has been employed in the diagnostic assessment of vascular rings. Sixteen-row MSCT is expected to further increase the diagnostic power of MSCT. We report three cases of double aortic arch diagnosed by a 16-row MSCT, and discuss the possible advantages of this diagnostic tool., Patients and Methods: From April 1, 2003, to September 1, 2003, three patients underwent 16-row MSCT at our institution to evaluate the possible presence of a vascular ring. All patients presented with stridor and feeding difficulties. MSCT was performed under bland sedation (chloral hydrate 60 mg/kg). ECG gating and breath hold were not employed. Three-dimensional reconstructions were employed to assess the presence of airway compromise as well as of vascular anomalies., Results: Scanning time averaged 4 s (3.8-4.5 s). Motion artefacts were not relevant. The CT scan showed the existence of a vascular anomaly as well as of a significant tracheal compression in all cases, and was considered conclusively diagnostic by the cardiac surgeons. All three patients underwent uncomplicated corrective surgery without further investigations., Conclusion: Sixteen-row MSCT with 3D reconstruction allows a precise evaluation of the airway compromise and a detailed assessment of the anatomy of vascular anomalies. The very short scanning time allows to avoid deep sedation and anaesthesia, and to obtain higher image quality and spatial resolution, with a concomitant reduction of the radiation dose.

The concentrations of thyroid hormones were measured in 14 pediatric patients before, during, and after cardiopulmonary bypass. The ages of the patients ranged between 18 months and 14 years. Patients were kept normothermic, or moderate or deep hypothermia was induced depending on the specific pathologic condition involved. A marked reduction in the levels of total triiodothyronine, total thyroxine, free triiodothyronine, and thyroid-stimulating hormone, and in the ratio of free triiodothyronine to free thyroxine was detected during the time frame of the study. The minimum levels of each hormone were reached between 12 and 48 hours after cardiopulmonary bypass, indicating that changes in thyroid function and in the conversion of thyroxine to triiodothyronine are triggered by cardiopulmonary bypass and represent specific phenomena, and that these changes are progressively exacerbated during the post-operative period. The thyroid-stimulating hormone level was markedly reduced versus its baseline values (24% +/- 0.13%), despite low levels of both total (40% +/- 18%) and free (39% +/- 20%) triiodothyronine: it returned to its preoperative level by the third postoperative day, but both the total (75% +/- 10%) and free (74% +/- 3%) triiodothyronine levels remained below their baseline values for 7 days postoperatively. Neither hemodilution nor hypothermia was responsible for the alteration observed. We conclude that pediatric patients undergoing cardiopulmonary bypass manifest changes in hormone metabolism similar to those seen in adult patients. These changes increase progressively during the postoperative period, and are still present 7 days postoperatively. The exact mechanism responsible for causing these changes is not thoroughly understood. Whether triiodothyronine replacement therapy is beneficial or deleterious remains controversial.