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1.
Materials (Basel) ; 14(20)2021 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-34683783

RESUMO

The construction sector is one of the most demanding sectors of raw materials in existence today. As a consequence, the extraction of these materials has a significant impact on the environment. At the same time, mining activities produce a series of wastes, in some cases with polluting elements, which must be treated to avoid pollution. Therefore, the use of mining waste for the conformation of new construction materials is an important environmental advantage, even more so when such waste is prevented from producing polluting leachates. Therefore, in this research, geopolymers are developed with mine tailings from the Linares lead mines, chemically activated with potassium hydroxide. For this purpose, different percentages of the alkaline activator were tested and the physical and mechanical properties of the conformed materials were evaluated. The analysis of the different conformed geopolymers determined the optimum percentage of potassium hydroxide for conforming the geopolymer with the best mechanical and physical properties. In addition, the concentration in the leachate of potentially contaminating chemical elements in the mining waste was estimated to be lower than those regulated by the regulations. Consequently, this research shows the development of a sustainable material for construction with mining waste and reduction of the environmental impact of traditional products.

2.
World Neurosurg ; 2021 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-34403796

RESUMO

BACKGROUND: Deep brain stimulation of the nucleus accumbens, ventral striatum, or internal capsule region has shown a 45%-60% response rate in adults with severe treatment-refractory obsessive-compulsive disorder, regardless of which target is used. We sought to improve the effectiveness of deep brain stimulation by placing the electrode along a trajectory including these 3 targets, enabling a change of stimulation site depending on the patient's response. METHODS: This study used the medical records of 14 patients from 4 different Spanish institutions: 7 from the Hospital Universitario La Princesa, 3 from the Hospital Universitario Central de Asturias, 2 from Hospital Universitario Fundación Jiménez Díaz, and 2 from Hospital Universitari Son Espases. All patients were operated on under the same protocol. Qualitative and quantitative data were collected. RESULTS: Of 14 patients, 11 showed significant improvement in obsessive-compulsive disorder symptoms, as evident in a reduction ≥35% in Yale-Brown Obsessive Compulsive Scale scores following stimulation relative to preoperative scores. Seven patients responded to stimulation at the nucleus accumbens (the first area we set for stimulation), whereas 4 patients needed to have the active contact switched to the internal capsule to benefit from stimulation. CONCLUSIONS: Deep brain stimulation of the nucleus accumbens, internal capsule, and ventral striatum significantly benefited our cohort of patients with medication-resistant obsessive-compulsive disorder. Electrode insertion through the 3 main targets might confer additional therapeutic efficacy.

3.
Materials (Basel) ; 14(13)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206646

RESUMO

Most concrete studies are concentrated on mechanical properties especially strength properties either directly or indirectly (fresh and durability properties). Hence, the ratio of split tensile strength to compressive strength plays a vital role in defining the concrete properties. In this review, the impact of design parameters on the strength ratio of various grades of Self-Compacting Concrete (SCC) with recycled aggregate is assessed. The design parameters considered for the study are Water to Cement (W/C) ratio, Water to Binder (W/B) ratio, Total Aggregates to Cement (TA/C) ratio, Fine Aggregate to Coarse Aggregate (FA/CA) ratio, Water to Solid (W/S) ratio in percentage, superplasticizer (SP) content (kg/cu.m), replacement percentage of recycled coarse aggregates (RCA), replacement percentage of recycled fine aggregates (RFA), fresh density and loading area of the specimen. It is observed that the strength ratio of SCC with recycled aggregates is affected by design parameters.

4.
Food Chem Toxicol ; 155: 112387, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34252473

RESUMO

Since seafood is a significant source of nutrients with known health benefits, its consumption is promoted as a healthy food choice. However, seafood can also contain potentially hazardous environmental pollutants. In the context of the ECsafeSEAFOOD FP7 project, FishChoice (www.fishchoice.eu) was developed as a communication tool to help to the consumers to take the most appropriate decisions on their seafood consumption habits. FishChoice relies on scientific information that allows calculating, on an individual basis, intakes of nutrients and pollutants derived from seafood consumption. In the framework of the EU-H2020 funded SEAFOODTOMORROW project, an optimized version of the online tool has been released. FishChoice is available in 25 EU languages with a customized list of seafood species per EU country, considering specific (national) consumption habits. The list of nutrients has been extended according to the latest EFSA recommendations, while pollutants data incorporate results from recent studies. The sustainability of seafood consumption has been also implemented, providing recommendations to help preserve the marine environment. Finally, FishChoice is suitable not only for consumers, but also health professionals, schools and academia, as well as the industrial sector and public health providers.

5.
Mol Brain ; 14(1): 115, 2021 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-34274007

RESUMO

T-type calcium channels are important regulators of neuronal excitability. The mammalian brain expresses three T-type channel isoforms (Cav3.1, Cav3.2 and Cav3.3) with distinct biophysical properties that are critically regulated by temperature. Here, we test the effects of how temperature affects spike output in a reduced firing neuron model expressing specific Cav3 channel isoforms. The modeling data revealed only a minimal effect on baseline spontaneous firing near rest, but a dramatic increase in rebound burst discharge frequency for Cav3.1 compared to Cav3.2 or Cav3.3 due to differences in window current or activation/recovery time constants. The reduced response by Cav3.2 could optimize its activity where it is expressed in peripheral tissues more subject to temperature variations than Cav3.1 or Cav3.3 channels expressed prominently in the brain. These tests thus reveal that aspects of neuronal firing behavior are critically dependent on both temperature and T-type calcium channel subtype.

6.
Light Sci Appl ; 10(1): 143, 2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34257273

RESUMO

Neuromodulation at high spatial resolution poses great significance in advancing fundamental knowledge in the field of neuroscience and offering novel clinical treatments. Here, we developed a tapered fiber optoacoustic emitter (TFOE) generating an ultrasound field with a high spatial precision of 39.6 µm, enabling optoacoustic activation of single neurons or subcellular structures, such as axons and dendrites. Temporally, a single acoustic pulse of sub-microsecond converted by the TFOE from a single laser pulse of 3 ns is shown as the shortest acoustic stimuli so far for successful neuron activation. The precise ultrasound generated by the TFOE enabled the integration of the optoacoustic stimulation with highly stable patch-clamp recording on single neurons. Direct measurements of the electrical response of single neurons to acoustic stimulation, which is difficult for conventional ultrasound stimulation, have been demonstrated. By coupling TFOE with ex vivo brain slice electrophysiology, we unveil cell-type-specific responses of excitatory and inhibitory neurons to acoustic stimulation. These results demonstrate that TFOE is a non-genetic single-cell and sub-cellular modulation technology, which could shed new insights into the mechanism of ultrasound neurostimulation.

7.
Am J Cardiol ; 151: 105-113, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34049674

RESUMO

Left atrial (LA) enlargement predicts adverse cardiovascular events in patients with chronic kidney disease (CKD). The aim of our study was to evaluate the value of LA reservoir strain, a novel measure of LA function, as a prognostic marker for adverse renal outcomes. A total of 280 patients (65.8 ± 12.2years, 63% male) with stable Stage 3 and 4 CKD without prior cardiac history were evaluated with transthoracic echocardiography and prospectively followed for up to 5 years. The primary end point was progressive renal failure, which was the composite of death from renal cause, end-stage renal failure and/or doubling of serum creatinine. Over a mean follow up of 3.9 ± 2.7years, 56 patients reached the composite endpoint. By log rank test, older age, lower baseline eGFR, anemia, diabetes mellitus, higher urinary albumin/creatinine ratio, number of antihypertensive medications, higher indexed left ventricular mass, larger LA volumes, and impaired LA reservoir strain were significant predictors of the composite outcome (p <0.01 for all). Multi-variable Cox regression analysis found LA reservoir strain, eGFR, number of antihypertensive medications and urinary albumin/creatinine ratio were independent predictors for progressive renal failure (p <0.01 for all). Impaired LA reservoir strain was associated with a 2.5-fold higher risk of the composite outcome (HR 2.51, 95% CI 1.19 to 5.30, p = 0.02) and was the only echocardiographic parameter that predicted progressive renal failure independent of established clinical risk factors for end-stage renal failure. Its utility requires validation in high risk CKD patients with cardiac disease.


Assuntos
Função do Átrio Esquerdo , Átrios do Coração/diagnóstico por imagem , Falência Renal Crônica/fisiopatologia , Insuficiência Renal Crônica/fisiopatologia , Idoso , Creatinina/sangue , Progressão da Doença , Ecocardiografia , Feminino , Seguimentos , Átrios do Coração/fisiopatologia , Humanos , Falência Renal Crônica/sangue , Falência Renal Crônica/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/mortalidade
9.
Clin Biochem ; 94: 80-82, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33901469

RESUMO

Sickle cell disease (SCD) is a common hemoglobinopathy, secondary to alterations in the ß globin chain, resulting in an abnormal hemoglobin variant named as hemoglobin S. These disorders show a wide phenotypical spectrum, and the prevalence of these disorders has significantly changed over the time because of multiple factors such as migration. We report a case of a 17-year-old black male, born in Gambia, diagnosed with sickle cell disease, who presented an associated mutation only described in a Japanese family (Oshima et al., 1996).


Assuntos
Anemia Hemolítica/genética , Mutação/genética , Talassemia/genética , Adolescente , Hemoglobinopatias/genética , Humanos , Masculino
10.
Microbiol Resour Announc ; 10(14)2021 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-33833023

RESUMO

HarryOW and Peeb are Mycobacterium smegmatis mc2 155 Siphoviridae temperate phages with 52,935 and 41,876 base pairs in genome length, respectively. HarryOW belongs to the A1 subcluster and Peeb to the G1 subcluster. They were isolated and annotated by students from the SUNY Old Westbury Science and Technology Entry Program.

11.
Clin Biochem ; 92: 77-81, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33675809

RESUMO

OBJECTIVE: To describe a new mutation causing alpha thalassemia and its mechanism of action. DESIGN AND METHODS: The propositus was a 37-year-old man who presented maintained microcytosis without iron deficiency. Molecular characterization was undertaken using automatic sequencing after testing negative for the most frequent α-globin mutations by multiplex PCR followed by reverse-hybridization. RESULTS: The mutation is a single base substitution at codon 65 of the α1 globin gene [α65(E14) Ala>Pro; HBA1: c.196G>C] and leads to the substitution of a proline residue in the E helix. The resulting hemoglobin variant has been named Hb Maruchi. This new variant cannot be separated from Hb A by electrophoretic and chromatographic techniques. CONCLUSIONS: The substitution α65(E14) Ala>Pro; HBA1: c.196G>C causes a α-thalassemia silent associated with a very mild phenotype. The diagnosis of this type of mutation is important because it may cause alpha thalassemia if inherited with other clinically relevant HBA1/HBA2 variants.


Assuntos
Hemoglobinas Anormais/genética , alfa-Globinas/genética , Talassemia alfa , Adulto , Humanos , Masculino , Mutação Puntual , Prolina/genética , Espanha , Talassemia alfa/diagnóstico , Talassemia alfa/genética
12.
Cir Esp (Engl Ed) ; 2021 Jan 29.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-33610261

RESUMO

INTRODUCTION: The COVID-19 pandemic led to the cancellation of non-essential surgical procedures in March 2020. With the resumption of surgical activity, patients undergoing surgery were one of the first population groups to be systematically tested for PCR. The aim of this study was to determine the prevalence of asymptomatic SARS-CoV-2 carriers after the resumption of non-essential surgical activity. METHODS: Retrospective multicenter observational study of patients scheduled for surgery or undergoing emergency surgery in Catalonia between 20 April and 31 May 2020. The microbiological results of preoperative PCR tests and clinical records were reviewed, and an epidemiological survey was conducted on patients with positive PCR for SARS-CoV-2. RESULTS: A total of 10,838 patients scheduled for surgery or who underwent emergency surgery were screened for COVID-19. One hundred and eighteen patients (1.09%) were positive for SARS-CoV-2 in the 72hours prior to surgery. The prevalence of asymptomatic carriers was 0.7% (95%CI: 0.6% - 0.9%). The first week of the study presented the highest prevalence of asymptomatic carriers [1.9% (95%CI: 1.1%-3.2%)]. CONCLUSIONS: The low levels of asymptomatic carriers of COVID-19 infection obtained in the surgical population of hospitals in Catalonia after the resumption of surgical activity, shows that most patients were able to undergo surgical procedures without the risks of COVID-19 associated complications in the perioperative period.

13.
J Clin Pathol ; 74(3): 198-201, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32796052

RESUMO

Screening of haemoglobinopathies is indicated for the detection of sickle cell anaemia; thus, neonates can benefit from early and adequate treatment that prevents neurological damage, reduces morbidity and mortality associated with the disease. These types of programmes sometimes lead to unexpected findings. We present a new haemoglobin (Hb) variant (Hb Miguel Servet) detected by newborn screening. During neonatal screening of haemoglobinopathies by cation-exchange high-performance liquid chromatography (CE-HPLC) newborn, an Hb variant was detected. An analysis at 8 months of age using capillary zone electrophoresis (CZE) confirmed the presence of this new Hb. The molecular characterisation was performed by automatic sequencing of the α and ß globin genes in an ABI PRISM 3100 Genetic Analyzer. Hb analysis by CE-HPLC ß-thalassaemia short programmedid not indicate the presence of abnormal Hbs. By CZE showed a peak in the zone 12 zone comprising 3.3% of the total Hb. A new analysis by CE-HPLC on a Tosoh G8-2 (Horiba) shown a peak, in the region of HbA1b, did not interfere with the quantification of HbA1c. Sequencing of the ß gene revealed the substitution of a guanine for a thymine (GGT >TGT) in codon 69 of the second exon, resulting in substitution of cysteine for the amino acid glutamine (HBB:c.208G>T). Hb Miguel Servet is a ß-chain globin variant detected by CE-HPLC newborn (BioRad), by CZE and by CE-HPLC-CE Tosoh G8-2 (Horiba), but no by CE-HPLC-CE ß-thalassaemia short programme (BioRad). In fact, for all the techniques that are visualised, what would be detected would be the glutathione variant of Hb (Miguel Servet).


Assuntos
Anemia Falciforme/diagnóstico , Hemoglobinopatias/diagnóstico , Talassemia beta/diagnóstico , Anemia Falciforme/genética , Anemia Falciforme/patologia , Cromatografia Líquida de Alta Pressão , Eletroforese Capilar , Hemoglobinopatias/genética , Hemoglobinopatias/patologia , Humanos , Masculino , Globinas beta/genética , Talassemia beta/genética , Talassemia beta/patologia
14.
J Am Soc Echocardiogr ; 34(2): 166-175, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33223356

RESUMO

BACKGROUND: Patients with chronic kidney disease (CKD) are at increased risk of adverse cardiovascular events, which is underestimated by traditional risk stratification algorithms. We sought to determine clinical and echocardiographic predictors of adverse outcomes in CKD patients. METHODS: Two hundred forty-three prospectively recruited stage 3/4 CKD patients (male, 63%; mean age, 59.2 ± 14.4 years) without previous cardiac disease made up the study cohort. All participants underwent a transthoracic echocardiogram, with left ventricular (LV) and left atrial (LA) strain analysis. Participants were followed for 3.9 ± 2.7 years for the primary end point of cardiovascular death and major adverse cardiovascular event (MACE). The secondary end point was the composite of all-cause death and MACE. RESULTS: Fifty-four patients met the primary end point, and 65 the secondary end point. On log-rank tests, older age, diabetes mellitus, anemia, greater LV mass, reduced LV global longitudinal strain, larger indexed LA volume, higher E/e' ratio, and reduced LA reservoir strain (LASr; P < .01 for all) were independent predictors of cardiovascular death and MACE. On multivariable regression analysis of univariate predictors, LASr (P < .01) was the only independent predictor for the primary end point as well as for the secondary end point. Receiver operating characteristic curve analysis showed LASr was a stronger predictor of adverse events (area under the curve [AUC] = 0.84) compared to the Framingham (AUC = 0.58) and Atherosclerotic Cardiovascular Disease (AUC = 0.59) risk scores. CONCLUSIONS: LASr is an independent predictor of cardiovascular death and MACE in CKD patients, superior to clinical risk scores, LV parameters, and LA volume.

15.
J Am Heart Assoc ; 10(1): e017840, 2021 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-33372523

RESUMO

Background Left atrial (LA) function plays a pivotal role in modulating left ventricular performance. The aim of our study was to evaluate the relationship between resting LA function by strain analysis and exercise capacity in patients with chronic kidney disease (CKD) and evaluate its utility compared with exercise E/e'. Methods and Results Consecutive patients with stage 3 and 4 CKD without prior cardiac history were prospectively recruited from outpatient nephrology clinics and underwent clinical evaluation and resting and exercise stress echocardiography. Resting echocardiographic parameters including E/e' and phasic LA strain (LA reservoir [LASr], conduit, and contractile strain) were measured and compared with exercise E/e'. A total of 218 (63.9±11.7 years, 64% men) patients with CKD were recruited. Independent clinical parameters associated with exercise capacity were age, estimated glomerular filtration rate, body mass index, and sex (P<0.01 for all), while independent resting echocardiographic parameters included E/e', LASr, and LA contractile strain (P<0.01 for all). Among resting echocardiographic parameters, LASr demonstrated the strongest positive correlation to metabolic equivalents achieved (r=0.70; P<0.01). Receiver operating characteristic curves demonstrated that LASr (area under the curve, 0.83) had similar diagnostic performance as exercise E/e' (area under the curve, 0.79; P=0.20 on DeLong test). A model combining LASr and clinical metrics showed robust association with metabolic equivalents achieved in patients with CKD. Conclusions LASr, a marker of decreased LA compliance is an independent correlate of exercise capacity in patients with stage 3 and 4 CKD, with similar diagnostic value to exercise E/e'. Thus, LASr may serve as a resting biomarker of functional capacity in this population.


Assuntos
Função do Átrio Esquerdo/fisiologia , Ecocardiografia/métodos , Tolerância ao Exercício/fisiologia , Átrios do Coração , Insuficiência Renal Crônica , Índice de Massa Corporal , Correlação de Dados , Feminino , Taxa de Filtração Glomerular , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/fisiopatologia , Índice de Gravidade de Doença
16.
Entropy (Basel) ; 22(6)2020 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-33286447

RESUMO

Nowadays, across the most important problems faced by health centers are those caused by the existence of patients who do not attend their appointments. Among others, these patients cause loss of revenue to the health centers and increase the patients' waiting list. In order to tackle these problems, several scheduling systems have been developed. Many of them require predicting whether a patient will show up for an appointment. However, obtaining these estimates accurately is currently a challenging problem. In this work, a systematic review of the literature on predicting patient no-shows is conducted aiming at establishing the current state-of-the-art. Based on a systematic review following the PRISMA methodology, 50 articles were found and analyzed. Of these articles, 82% were published in the last 10 years and the most used technique was logistic regression. In addition, there is significant growth in the size of the databases used to build the classifiers. An important finding is that only two studies achieved an accuracy higher than the show rate. Moreover, a single study attained an area under the curve greater than the 0.9 value. These facts indicate the difficulty of this problem and the need for further research.

17.
Int. j. odontostomatol. (Print) ; 14(4): 540-543, dic. 2020.
Artigo em Espanhol | LILACS | ID: biblio-1134534

RESUMO

RESUMEN: El coronavirus tipo 2, SARS-CoV-2, que causa la enfermedad denominada por la OMS como COVID-19, se ha expandido provocando una pandemia desde 2019, sin cura hasta la fecha. El mecanismo de transmisión del SARS-CoV-2 entre humanos es mediante las secreciones generadas durante la respiración y estornudos, presentándose con un período de incubación desde 1 a 14 días. Se describen fiebre, tos y astenia como los síntomas más habituales. El diagnóstico definitivo se logra a través de la correlación entre la presentación clínica y exámenes complementarios, pero en la actualidad, el método de muestreo de preferencia para el diagnóstico de SARS-CoV-2 es mediante una muestra de nasofaringe, en donde se analiza la presencia de material genético viral por medio de RT-PCR. Debido a las complicaciones en la obtención de la muestra, tanto para el personal sanitario como para el paciente, se ha implementado la muestra de saliva con finalidad diagnóstica, como un método que proporciona una detección rápida, simple y no invasiva de la infección viral. Esta alternativa diagnóstica podría entregar información respecto a la patogenia de la enfermedad, permitiendo el manejo y control de pacientes positivos. El siguiente artículo, tiene por objetivo realizar una comparación entre las tomas de muestra de saliva y de nasofaringe para el diagnóstico de SARS-CoV-2, mediante la prueba de reacción en cadena de la polimerasa con transcriptasa inversa (RT-PCR).


SUMMARY: The type 2 coronavirus, SARS-CoV-2, named by the WHO like COVID-19, has expanded causing a pandemic since 2019, with no cure to date. The mechanism of transmission of SARS-CoV-2 between humans is through secretions generated during breathing and sneezing, presenting with an incubation period range from 1 - 14 days. Fever, cough, and fatigue are described as the most common symptoms. The definitive diagnosis is achieved through the correlation between the clinical presentation and the complementary exams, but at present, the preferred sampling method for the diagnosis of SARS-CoV-2 is through a nasopharyngeal swab specimen, where it is analyzed the presence of viral genetic material by the RT-PCR. Due to the complications in obtaining the sample, both for health personnel and for the patient, the saliva sample has been implemented, as a method that provides rapid, simple and non-invasive detection of viral infection. This diagnostic alternative could provide information on the pathogenesis of the disease, the management and control of positive patients. The following article aims to make a comparison between the saliva and nasopharyngeal samples taken for the diagnosis of SARS-CoV-2, using the reverse transcription polymerase chain reaction test (RT-PCR).


Assuntos
Saliva/virologia , Infecções por Coronavirus/diagnóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Betacoronavirus , Nasofaringe/virologia , Infecções por Coronavirus/epidemiologia , Técnicas de Laboratório Clínico
18.
Materials (Basel) ; 13(24)2020 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-33339318

RESUMO

This article presents an overview of the bibliographic picture of the design parameter's influence on the mix proportion of self-compacting concrete with recycled aggregate. Design parameters like water-cement ratio, water to paste ratio, and percentage of superplasticizers are considered in this review. Standardization and recent research on the usage of recycled aggregates in self-compacting concrete (SCC) exploit its significance in the construction sector. The usage of recycled aggregate not only resolves the negative impacts on the environment but also prevents the usage of natural resources. Furthermore, it is necessary to understand the recycled aggregate property's role in a mixed design and SCC properties. Design parameters are not only influenced by a mix design but also play a key role in SCC's fresh properties. Hence, in this overview, properties of SCC ingredients, calculation of design parameters in mix design, the effect of design parameters on fresh concrete properties, and the evolution of fresh concrete properties are studied.

19.
Microbiol Resour Announc ; 9(45)2020 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-33154012

RESUMO

Rahel is a lytic Myoviridae bacteriophage that infects Mycobacterium smegmatis mc2155. It has 1,555,955 bp and 64.7% G+C content. Rahel has a circularly permuted genome with 270 genes, 53 of them of known function, 33 tRNAs, and 1 transfer-messenger RNA (tmRNA). Only five genes are coded on the reverse strand.

20.
J Neurosci ; 40(50): 9576-9588, 2020 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-33158963

RESUMO

Single-cell analysis is revealing increasing diversity in gene expression profiles among brain cells. Traditional promotor-based viral gene expression techniques, however, cannot capture the growing variety among single cells. We demonstrate a novel viral gene expression strategy to target cells with specific miRNA expression using miRNA-guided neuron tags (mAGNET). We designed mAGNET viral vectors containing a CaMKIIα promoter and microRNA-128 (miR-128) binding sites, and labeled CaMKIIα+ cells with naturally low expression of miR-128 (Lm128C cells) in male and female mice. Although CaMKIIα has traditionally been considered as an excitatory neuron marker, our single-cell sequencing results reveal that Lm128C cells are CaMKIIα+ inhibitory neurons of parvalbumin or somatostatin subtypes. Further evaluation of the physiological properties of Lm128C cell in brain slices showed that Lm128C cells exhibit elevated membrane excitability, with biophysical properties closely resembling those of fast-spiking interneurons, consistent with previous transcriptomic findings of miR-128 in regulating gene networks that govern membrane excitability. To further demonstrate the utility of this new viral expression strategy, we expressed GCaMP6f in Lm128C cells in the superficial layers of the motor cortex and performed in vivo calcium imaging in mice during locomotion. We found that Lm128C cells exhibit elevated calcium event rates and greater intrapopulation correlation than the overall CaMKIIα+ cells during movement. In summary, the miRNA-based viral gene targeting strategy described here allows us to label a sparse population of CaMKIIα+ interneurons for functional studies, providing new capabilities to investigate the relationship between gene expression and physiological properties in the brain.SIGNIFICANCE STATEMENT We report the discovery of a class of CaMKIIα+ cortical interneurons, labeled via a novel miRNA-based viral gene targeting strategy, combinatorial to traditional promoter-based strategies. The fact that we found a small, yet distinct, population of cortical inhibitory neurons that express CaMKIIα demonstrates that CaMKIIα is not as specific for excitatory neurons as commonly believed. As single-cell sequencing tools are providing increasing insights into the gene expression diversity of neurons, including miRNA profile data, we expect that the miRNA-based gene targeting strategy presented here can help delineate many neuron populations whose physiological properties can be readily related to the miRNA gene regulatory networks.


Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/genética , Marcação de Genes , Interneurônios/metabolismo , MicroRNAs/genética , Córtex Motor/metabolismo , Animais , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Feminino , Vetores Genéticos , Masculino , Camundongos , MicroRNAs/metabolismo
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