Mutational Analysis of the Cyanobacterial Nitrogen Regulator PipX

PipX provides a functional link between the cyanobacterial global transcriptional regulator NtcA and the signal transduction protein PII, a protein found in all three domains of life as integrators of signals of the nitrogen and carbon balance. PipX, which is toxic in the absence of PII, can form alternative complexes with NtcA and PII and these interactions are respectively stimulated and inhibited by 2-oxoglutarate, providing a mechanism by which PII can modulate expression at the NtcA regulon. Structural information on PipX-NtcA complexes suggests that PipX coactivates NtcA controlled genes by stabilizing the active conformation of NtcA bound to 2-oxoglutarate and by possibly helping recruit RNA polymerase. To get insights into PipX functions, we perform here a mutational analysis of pipX informed by the structures of PipX-PII and PipX-NtcA complexes and evaluate the impact of point mutations on toxicity and gene expression. Two amino acid substitutions (Y32A and E4A) were of particular interest, since they increased PipX toxicity and activated NtcA dependent genes in vivo at lower 2-oxoglutarate levels than wild type PipX. While both mutations impaired complex formation with PII, only Y32A had a negative impact on PipX-NtcA interactions

New Insight into the Transcarbamylase Family: The Structure of Putrescine Transcarbamylase, a Key Catalyst for Fermentative Utilization of Agmatine

Transcarbamylases reversibly transfer a carbamyl group from carbamylphosphate (CP) to an amine. Although aspartate transcarbamylase and ornithine transcarbamylase (OTC) are well characterized, little was known about putrescine transcarbamylase (PTC), the enzyme that generates CP for ATP production in the fermentative catabolism of agmatine. We demonstrate that PTC (from Enterococcus faecalis), in addition to using putrescine, can utilize L-ornithine as a poor substrate. Crystal structures at 2.5 Å and 2.0 Å resolutions of PTC bound to its respective bisubstrate analog inhibitors for putrescine and ornithine use, N-(phosphonoacetyl)-putrescine and δ-N-(phosphonoacetyl)-L-ornithine, shed light on PTC preference for putrescine. Except for a highly prominent C-terminal helix that projects away and embraces an adjacent subunit, PTC closely resembles OTCs, suggesting recent divergence of the two enzymes. Since differences between the respective 230 and SMG loops of PTC and OTC appeared to account for the differential preference of these enzymes for putrescine and ornithine, we engineered the 230-loop of PTC to make it to resemble the SMG loop of OTCs, increasing the activity with ornithine and greatly decreasing the activity with putrescine. We also examined the role of the C-terminal helix that appears a constant and exclusive PTC trait. The enzyme lacking this helix remained active but the PTC trimer stability appeared decreased, since some of the enzyme eluted as monomers from a gel filtration column. In addition, truncated PTC tended to aggregate to hexamers, as shown both chromatographically and by X-ray crystallography. Therefore, the extra C-terminal helix plays a dual role: it stabilizes the PTC trimer and, by shielding helix 1 of an adjacent subunit, it prevents the supratrimeric oligomerizations of obscure significance observed with some OTCs. Guided by the structural data we identify signature traits that permit easy and unambiguous annotation of PTC sequences

CIBERER : Spanish national network for research on rare diseases: A highly productive collaborative initiative

Altres ajuts: Instituto de Salud Carlos III (ISCIII); Ministerio de Ciencia e Innovación.CIBER (Center for Biomedical Network Research; Centro de Investigación Biomédica En Red) is a public national consortium created in 2006 under the umbrella of the Spanish National Institute of Health Carlos III (ISCIII). This innovative research structure comprises 11 different specific areas dedicated to the main public health priorities in the National Health System. CIBERER, the thematic area of CIBER focused on rare diseases (RDs) currently consists of 75 research groups belonging to universities, research centers, and hospitals of the entire country. CIBERER's mission is to be a center prioritizing and favoring collaboration and cooperation between biomedical and clinical research groups, with special emphasis on the aspects of genetic, molecular, biochemical, and cellular research of RDs. This research is the basis for providing new tools for the diagnosis and therapy of low-prevalence diseases, in line with the International Rare Diseases Research Consortium (IRDiRC) objectives, thus favoring translational research between the scientific environment of the laboratory and the clinical setting of health centers. In this article, we intend to review CIBERER's 15-year journey and summarize the main results obtained in terms of internationalization, scientific production, contributions toward the discovery of new therapies and novel genes associated to diseases, cooperation with patients' associations and many other topics related to RD research

Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216

Is There an Adequate Therapeutic Approach to Thyroid Pathology in Patients with Down Syndrome?

Thyroid dysfunction stands as the most prevalent endocrine disorder in individuals with Down syndrome, particularly showcasing both clinical and subclinical hypothyroidism. TSH and FT4 blood values serve as common diagnostic and treatment adjustment markers. In Down syndrome (DS), hormone values may deviate from those observed in the general population, which may lead to overdiagnosis and consequent iatrogenesis of subclinical hypothyroidism. The objective of this study was to analyze the appropriateness of the replacement therapeutic approach by identifying the TSH and FT4 values that can be considered normal in these patients. Methods: A cross-sectional study was conducted in 503 subjects with DS of both sexes and without age limit drawn from the Health Program for individuals with DS in Valencia (Spain) from February 1993 to November 2021. The exclusion criteria included hyperthyroidism, nodules, tumors, or individuals under treatment with drugs influencing iodine metabolism. The normality of data distribution was assessed using the Shapiro–Wilk test. Outliers were detected using the Reed’s criterion. Hormone values were estimated using quantile regression models for the 2.5th and 97.5th percentiles. Results: The normal values identified were 0.88–11.25 mIU/L for TSH and 0.71–1.63 ng/dL for FT4. The Wald test indicated no significant differences in the reference intervals based on age or sex. Conclusion: The establishment of these values, which, in people with DS, can be considered unique, is of great importance, allowing a watchful waiting attitude to be maintained before starting replacement therapy that is unnecessarily or adjusting medication in diagnosed cases

Selective use of diagnostic tests inpatients with syncope of unknown cause

AbstractObjectivesWe sought to prospectively assess the diagnostic yielding of a protocol in which electrophysiologic studies (EPS), tilt-table tests (TTTs), and loop recorder implantation are selectively used.BackgroundThe optimal strategy in the diagnosis of patients with syncope of unknown cause has not been defined.MethodsA total of 184 consecutive patients with syncope of unknown cause were classified into two groups. Group A consisted of 72 patients fulfilling any of the following criteria: 1) presence of structural heart disease or family history of sudden death; 2) abnormal electrocardiogram; 3) significant non-symptomatic arrhythmia on Holter monitoring; and 4) paroxysmal palpitations immediately before or after syncope. These patients initially underwent an EPS and, if this study was negative, TTT. In the remaining 112 patients (group B), TTT was performedResultsThe EPS was positive in 32 patients (44%) in group A. The TTT was positive in 80 patients (71%) in group B. An additional patient had carotid sinus hypersensitivity. In patients of group A with a negative EPS, the TTT was positive in 23 (57%). A loop recorder was implanted in 15 patients from group A with negative conventional testing, and diagnostic activation was obtained in seven patients. Overall, a positive diagnosis was achieved in 143 patients (78%).ConclusionsIn patients with syncope of unknown cause, selective use of EPS or TTT leads to a positive diagnosis in >70% of the cases. An implantable loop recorder can be useful in non-diagnosed cases

Effects of spontaneous mutations in PipX functions and regulatory complexes on the cyanobacterium Synechococcus elongatus strain PCC 7942

In Synechococcus elongatus sp. PCC 7942, PipX forms complexes with PII, a protein found in all three domains of life as an integrator of signals of the nitrogen and carbon balance, and with the cyanobacterial nitrogen regulator NtcA. We recently showed that previous inactivation of pipX facilitates subsequent inactivation of the glnB gene. Here, we show that the three spontaneous pipX point mutations pipX-92delT, pipX160C>T and pipX194T>A, initially found in different glnB strains, are indeed suppressor mutations. When these mutations were reconstructed in the wild-type background, the glnB gene could be efficiently inactivated. Furthermore, the point mutations have different effects on PipX levels, coactivation of NtcA-dependent genes and protein–protein interactions. Further support for an in vivo role of PipX–PII complexes is provided by interaction analysis with the in vivo-generated PIIT-loop+7 protein, a PII derivative unable to interact with its regulatory target N-acetyl-L-glutamate kinase, but which retains the ability to bind to PipX. The implications of these results are discussed.This work was supported by grants BFU2006-12424, BFU2009-07374, ACOMP06/083, PR2009-0378 and HA2007-0074. M.A.C. is the recipient of a predoctoral fellowship from the Universidad de Alicante

Metabolomic Profile of Human Myocardial Ischemia by Nuclear Magnetic Resonance Spectroscopy of Peripheral Blood Serum A Translational Study Based on Transient Coronary Occlusion Models

Objectives The aim of this study was to investigate the metabolomic profile of acute myocardial ischemia (MIS) using nuclear magnetic resonance spectroscopy of peripheral blood serum of swine and patients undergoing angioplasty balloon-induced transient coronary occlusion. Background Biochemical detection of MIS is a major challenge. The validation of novel biosignatures is of utmost importance. Methods High-resolution nuclear magnetic resonance spectroscopy was used to profile 32 blood serum metabolites obtained (before and after controlled ischemia) from swine (n = 9) and patients (n = 20) undergoing transitory MIS in the setting of planned coronary angioplasty. Additionally, blood serum of control patients (n = 10) was sequentially profiled. Preliminary clinical validation of the developed metabolomic biosignature was undertaken in patients with spontaneous acute chest pain (n = 30). Results Striking differences were detected in the blood profiles of swine and patients immediately after MIS. MIS induced early increases (10 min) of circulating glucose, lactate, glutamine, glycine, glycerol, phenylalanine, tyrosine, and phosphoethanolamine; decreases in choline-containing compounds and triacylglycerols; and a change in the pattern of total, esterified, and nonesterified fatty acids. Creatine increased 2 h after ischemia. Using multivariate analyses, a biosignature was developed that accurately detected patients with MIS both in the setting of angioplasty-related MIS (area under the curve 0.94) and in patients with acute chest pain (negative predictive value 95%). Conclusions This study reports, to the authors' knowledge, the first metabolic biosignature of acute MIS developed under highly controlled coronary flow restriction. Metabolic profiling of blood plasma appears to be a promising approach for the early detection of MIS in patients. (J Am Coll Cardiol 2012;59:1629-41) (c) 2012 by the American College of Cardiology FoundationFrom the *Cardiology Department, Hospital Clinico Universitario-INCLIVA, Universidad de Valencia, Valencia, Spain; dagger Unidad Central de Investigacion en Medicina, Universidad de Valencia, Valencia, Spain; double dagger Centro de Biomateriales e Ingenier a Tisular, Universidad Politecnica de Valencia, Valencia, Spain; Department of Clinical Analyses, Hospital Clinico Universitario-INCLIVA, Valencia, Spain; parallel to Cardiology Department, Hospital Clinic, IDIBAPS, Universidad de Barcelona, Barcelona, Spain; Department of Biochemistry and Molecular Biology, Facultad de Medicina, Universidad de Valencia, Valencia, Spain; and the #Fundacion Investigacion, Hospital Clinico Universitario-INCLIVA, Valencia, Spain. The present study was supported by Instituto de Salud Carlos III (PI 11/02323 and Heracles grants to Dr. Bodi), Fundacion Gent per Gent (to Drs. Bodi and Monleon), the Ministry of Science and Innovation of Spain (grant SAF2008- 00270 to Dr. Monleon), and Generalitat Valenciana (grant GVASAN AP014/2009 to Dr. Monleon and grant PROMETEO2010-075 to Dr. Vina). Dr. Monleon gratefully acknowledges a 2006 Ramon y Cajal contract from the Ministry of Education of Spain. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.Bodi, V.; Sanchis, J.; Morales, JM.; Marrachelli, VG.; Nunez, J.; Forteza, MJ.; Chaustre Mendoza, LF.... (2012). Metabolomic Profile of Human Myocardial Ischemia by Nuclear Magnetic Resonance Spectroscopy of Peripheral Blood Serum A Translational Study Based on Transient Coronary Occlusion Models. Journal of the American College of Cardiology. 59(18):1629-1641. https://doi.org/10.1016/j.jacc.2011.09.083S16291641591