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1.
J Physiol ; 600(18): 4227-4245, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35861594

RESUMO

In patients with chronic obstructive pulmonary disease (COPD), exertional dyspnoea generally arises when there is imbalance between ventilatory demand and capacity, but the neurophysiological mechanisms are unclear. We therefore determined if disparity between elevated inspiratory neural drive (IND) and tidal volume (VT ) responses (neuromechanical dissociation) impacted dyspnoea intensity and quality during exercise, across the COPD severity spectrum. In this two-centre, cross-sectional observational study, 89 participants with COPD divided into tertiles of FEV1 %predicted (Tertile 1 = FEV1 = 87 ± 9%, Tertile 2 = 60 ± 9%, Tertile 3 = 32 ± 8%) and 18 non-smoking controls, completed a symptom-limited cardiopulmonary exercise test (CPET) with measurement of IND by diaphragm electromyography (EMGdi (%max)). The association between increasing dyspnoea intensity and EMGdi (%max) during CPET was strong (r = 0.730, P < 0.001) and not different between the four groups who showed marked heterogeneity in pulmonary gas exchange and mechanical abnormalities. Significant inspiratory constraints (tidal volume/inspiratory capacity (VT /IC) ≥ 70%) and onset of neuromechanical dissociation (EMGdi (%max):VT /IC > 0.75) occurred at progressively lower minute ventilation ( V ̇ E ${\dot{V}}_{{\rm{E}}}$ ) from Control to Tertile 3. Lower resting IC meant earlier onset of neuromechanical dissociation, heightened dyspnoea intensity and greater propensity (93% in Tertile 3) to select qualitative descriptors of 'unsatisfied inspiration'. We concluded that, regardless of marked variation in mechanical and pulmonary gas exchange abnormalities in our study sample, exertional dyspnoea intensity was linked to the magnitude of EMGdi (%max). Moreover, onset of critical inspiratory constraints and attendant neuromechanical dissociation amplified dyspnoea intensity at higher exercise intensities. Simple measurements of IC and breathing pattern during CPET provide useful insights into mechanisms of dyspnoea and exercise intolerance in individuals with COPD. KEY POINTS: Dyspnoea during exercise is a common and troublesome symptom reported by patients with chronic obstructive pulmonary disease (COPD) and is linked to an elevated inspiratory neural drive (IND). The precise mechanisms of elevated IND and dyspnoea across the continuum of airflow obstruction severity in COPD remains unclear. The present study sought to determine the mechanisms of elevated IND (by diaphragm EMG, EMGdi (%max)) and dyspnoea during cardiopulmonary exercise testing (CPET) across the continuum of COPD severity. There was a strong association between increasing dyspnoea intensity and EMGdi (%max) during CPET across the COPD continuum despite significant heterogeneity in underlying pulmonary gas exchange and respiratory mechanical impairments. Critical inspiratory constraints occurred at progressively lower ventilation during exercise with worsening severity of COPD. This was associated with the progressively lower resting inspiratory capacity with worsening disease severity. Earlier critical inspiratory constraint was associated with earlier neuromechanical dissociation and greater likelihood of reporting the sensation of 'unsatisfied inspiration'.


Assuntos
Doença Pulmonar Obstrutiva Crônica , Mecânica Respiratória , Estudos Transversais , Dispneia , Teste de Esforço , Humanos , Testes de Função Respiratória , Mecânica Respiratória/fisiologia
2.
Ann Ig ; 34(6): 627-634, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35107122

RESUMO

Background: The International Standardization Organization operates the world's most widely recognized quality management system standard, the ISO 9001:2015. In the healthcare sector, the adoption of this standard within an organization helps to improve the overall performance and provides a foundation for development and continuous progress. Our study aims to describe the implementation process of a quality management system according to the ISO 9001:2015 standards in an Angiology Unit of an Italian Univer-sity hospital. Methods: The project was structured in 5 operational phases, which were carried out during a time frame of 14 months (March 2018-May 2019) and entailed several improvement actions associated with quality and safety outputs such as clinical management, clinical practice, safety, and patient-centeredness. Results: Implementation of the quality management system led to the improvement of many aspects of the processes performed in the Angiology Unit, both in the outpatient and day hospital setting. Overall, the project positively impacted on systems for patient safety, particularly in communication and data transmis-sion, and clinical leadership. Conclusions: The implementation of the ISO 9001 certification is a process that apparently may seem ex-pensive in terms of resources used, commitment, work, comparison, but it leads to substantial and always progressive improvements in the offer of Services to the user, safety both for the users and for the healthcare personnel involved, in addition to the care processes that translate into significant benefits in terms of quality of care for patients, as well as management savings for the organization.


Assuntos
Cardiologia , Hospitais , Certificação , Humanos , Segurança do Paciente , Padrões de Referência
3.
BMC Pediatr ; 20(1): 201, 2020 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-32386509

RESUMO

BACKGROUND: Monosomy 1p36 is the most common terminal deletion syndrome with an autosomal dominant pattern of inheritance. This syndrome is defined by an extremely wide spectrum of characteristics; however, developmental delay and intellectual disability of various degree are present in all patients and about the 90% of patients have a severe intellectual disability. Dental agenesis or other dental anomalies have not been described in previous reports. CASE PRESENTATION: We report the case of two little sisters born from healthy and non-consanguineous parents, presenting with dental anomalies and one of them with epilepsy, dilated cardiomyopathy with left-ventricular non-compaction, strabismus, history of poor growth, hypotonia and mild language delay. Patients were evaluated in several departments (genetic, child neuropsychiatric, cardiology, odontostomatology, ophthalmology, otorhinolaryngology) of Institute for Maternal and Child Health, IRCCS Burlo Garofolo, Trieste, Italy. They underwent investigations such as electrocardiogram, echocardiogram, dental orthopantomography X-Ray and Computed Tomography, electroencephalograms, abdomen ultrasound, blood tests, IQ tests, genetic analysis. They both have an Intelligence Quotient greater than 70 and a negative neurologic exam. Each sister carries the same 1p36 deletion of about 2.3 Mb. Genetic analysis of the parents' blood samples (Single Nucleotide Polymorphism- array, karyotype and Fluorescent In Situ Hybridization) did not reveal any deletion, translocation or inversion and confirmed the paternity. A third sib of the probands does not carry the 1p36 deletion or other quantitative alterations. CONCLUSION: This report describes a new trait linked to monosomy 1p36, namely a mild intellectual outcome associated with significant dental anomalies. Our finding suggests that 1p36 deletion syndrome may present with a mild cognitive impairment or even with a normal intellectual development: this is very important for the genetic counselling, especially in a prenatal setting. Moreover, we report the third study with recurrent 1p36 deletion syndrome in two siblings, likely due to germline mosaicism. Finally, we believe that the dental anomalies should be investigated in 1p36 deletion syndrome and that the spectrum of the condition could be broader than we assume.


Assuntos
Células Germinativas , Mosaicismo , Criança , Deleção Cromossômica , Transtornos Cromossômicos , Cromossomos Humanos Par 1 , Humanos , Hibridização in Situ Fluorescente , Itália
4.
PLoS One ; 19(2): e0298052, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38394148

RESUMO

BACKGROUND: Personal Protective Equipment (PPE) Portraits is a hybridized art and medical intervention that lessens the alienating appearance of PPE through wearable, smiling headshot pictures. During the pandemic, the use of these portraits was expanded, but Canadian initiatives offered portraits only to immediate stakeholders. PPE Portraits Canada (PPC) aimed to provide PPE portraits to any Canadian healthcare institution and surveyed healthcare workers (HCW) regarding these portraits' impact. METHODS: University student volunteers founded PPC via online platforms and coast-to-coast collaborations that allowed any HCW nationwide to request a free portrait via an accessible online form. PPC has gathered feedback from participating HCWs directly via an anonymous and bilingual survey. RESULTS: 70% of HCWs wore their portraits "always" or "usually", 69% of HCWs "definitely would" recommend their portrait, 89.5% of HCWs found that the PPE portraits made a difference in their experiences with patients and 74% found the same for their colleagues. The pre- and post-effect of the portraits, led to a 37.5% greater likelihood that HCWs felt "connected" or "very connected" to patients/residents. For the thematic analysis, 70% or more of the comments were rated as positive, with less than 5% of comments being rated as negative. CONCLUSION: This model's logistical framework can be expanded beyond PPE portraits to other initiatives with limited resources, allowing them to reach and positively impact diverse populations. HCW feedback was predominantly positive. The optimal design and impact of PPE portraits on patients and HCWs should be studied further to improve portrait adoption.


Assuntos
Pessoal de Saúde , Equipamento de Proteção Individual , Humanos , Canadá , Instalações de Saúde , Pandemias
5.
Artigo em Inglês | MEDLINE | ID: mdl-23956498

RESUMO

We present a microfluidic based injection system designed to achieve intracellular delivery of macromolecules by directing a picoliter-jet of a solution towards individual cells. After discussing the concept, we present design specification and criteria, elucidate performance and discuss results. The method has the potential to be quantitative and high throughput, overcoming limitations of current intracellular delivery protocols.

6.
ERJ Open Res ; 9(5)2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37753287

RESUMO

Background: Computed tomography (CT) is increasingly used for assessing skeletal muscle characteristics. In cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD), reduced limb muscle mass predicts poor clinical outcomes. However, the degree to which quantity or quality of respiratory and nonrespiratory muscles is affected by these diseases remains controversial. Methods: Thoracic CT images of 29 CF, 21 COPD and 20 normal spirometry control subjects were analysed to measure indices of muscle quantity (volume or cross-sectional area) and quality (radiodensity) in respiratory (diaphragm, abdominal) and nonrespiratory (pectoralis, lumbar paraspinal) muscles. Multivariable linear regression assessed relationships of CT measurements with body mass index (BMI), forced expiratory volume in 1 s (FEV1) % pred, inflammation and infection biomarkers, nutritional status and CF genotype. Results: Diaphragm volume in CF was significantly higher than in COPD (by 154%) or controls (by 140%). Abdominal muscle area in CF was also greater than in COPD (by 130%). Nonrespiratory muscles in COPD had more low radiodensity muscle (marker of lipid content) compared to CF and controls. In CF but not COPD, higher BMI and FEV1 % pred were independently associated with higher diaphragm and/or abdominal muscle quantity indices. Serum creatinine also predicted respiratory and nonrespiratory muscle quantity in CF, whereas other biomarkers including genotype correlated poorly with muscle CT parameters. Conclusions: Our data suggest that the CF diaphragm undergoes hypertrophic remodelling, whereas in COPD the nonrespiratory muscles show altered muscle quality consistent with greater lipid content. Thoracic CT can thus identify distinctive respiratory and nonrespiratory muscle remodelling signatures associated with different chronic lung diseases.

7.
bioRxiv ; 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-38106192

RESUMO

Chromothripsis, the process of catastrophic shattering and haphazard repair of chromosomes, is a common event in cancer. Whether chromothripsis might constitute an actionable molecular event amenable to therapeutic targeting remains an open question. We describe recurrent chromothripsis of chromosome 21 in a subset of patients in blast phase of a myeloproliferative neoplasm (BP-MPN), which alongside other structural variants leads to amplification of a region of chromosome 21 in ∼25% of patients ('chr21amp'). We report that chr21amp BP-MPN has a particularly aggressive and treatment-resistant phenotype. The chr21amp event is highly clonal and present throughout the hematopoietic hierarchy. DYRK1A , a serine threonine kinase and transcription factor, is the only gene in the 2.7Mb minimally amplified region which showed both increased expression and chromatin accessibility compared to non-chr21amp BP-MPN controls. We demonstrate that DYRK1A is a central node at the nexus of multiple cellular functions critical for BP-MPN development, including DNA repair, STAT signalling and BCL2 overexpression. DYRK1A is essential for BP-MPN cell proliferation in vitro and in vivo , and DYRK1A inhibition synergises with BCL2 targeting to induce BP-MPN cell apoptosis. Collectively, these findings define the chr21amp event as a prognostic biomarker in BP-MPN and link chromothripsis to a druggable target.

8.
Ann Biomed Eng ; 50(4): 387-400, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35171393

RESUMO

Immunohistochemistry for vascular network analysis plays a fundamental role in basic science, translational research and clinical practice. However, identifying vascularization in histological tissue images is time consuming and markedly depends on the operator's experience. In this study, we present "blood vessel detection-BVD", an automatic algorithm for quantitative analysis of blood vessels in immunohistochemical images. BVD is based on extraction and analysis of low-level image features and spatial filtering techniques, which do not require a training phase. BVD algorithm performance was comparatively evaluated on histological sections from three different in vivo experiments. Collectively, 173 independent images were analyzed, and the algorithm's results were compared to those obtained by human operators. The developed BVD algorithm proved to be a robust and versatile tool, being able to quantify number, area, and spatial distribution of blood vessels within all three considered histologic datasets. BVD is provided as an open-source application working on different operating systems. BVD is supported by a user-friendly graphical interface designed to facilitate large-scale analysis.


Assuntos
Algoritmos , Engenharia Tecidual , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imuno-Histoquímica , Neovascularização Patológica
9.
Asian J Neurosurg ; 17(3): 399-406, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36398177

RESUMO

Ventriculo-peritoneal shunt placement is the most commonly performed procedure for the treatment of hydrocephalus. The complication of migration of the distal ventriculo-peritoneal shunt is one of the many complications that occur after ventriculo-peritoneal shunt placement. The migration of the ventriculo-peritoneal shunt through the vagina is infrequently reported in children. The aim of this review is to help all the providers caring for children with ventriculo-peritoneal shunts to identify issues early when encountered with this complication and thus limit morbidity and mortality. We reviewed all cases of migration of ventriculo-peritoneal shunt through the vagina in children less than 18 years of age that were published in the literature using PubMed, Google Scholar, Web of Science, and Cochrane Library. A total of 11 articles met the eligibility criteria and were included in this review among the 93 articles obtained with title and abstract screening. Previous non-shunt-related abdominal operations and shunt revisions are consistent risk factors in all cases. We did not recognize specific approaches to catheter placement or management that could have prevented this complication. Ventriculitis necessitating shunt removal and therapies requiring additional procedures and prolonged hospitalization are the major consequences identified. Awareness of this unusual complication is very important among health care providers such as emergency care health providers who are likely to be the first to encounter these children on initial presentation.

10.
Can Med Educ J ; 13(6): 80-89, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36440078

RESUMO

Organizational backends and logistics are often complex and many institutions set-up their workflows based on manual and tedious processes that negatively shape their interactions with stakeholders. Incorporating new technologies can be intimidating. However, a plethora of financially and technically accessible resources that do not require any coding knowledge, can be utilized by institutions to enhance their organizational workflow and stakeholder experience. Guided by our own learning experiences in optimal logistical set-up and user design, we wish to highlight five effective and easily implementable tricks to aid higher institutions and student groups in healthcare to accomplish their administrative duties.


Les backends et la logistique des organisations sont souvent complexes et de nombreuses institutions établissent leurs flux de travail sur la base de processus manuels et fastidieux qui influencent négativement leurs interactions avec les parties prenantes. L'intégration de nouvelles technologies peut être intimidante. Cependant, il existe une pléthore de ressources financièrement et techniquement accessibles, qui ne nécessitent aucune connaissance en codage, que les institutions peuvent utiliser pour améliorer leur flux de travail organisationnel et l'expérience des parties prenantes. Guidés par nos propres expériences d'apprentissage en matière de mise en place d'une logistique optimale et de conception pour l'utilisateur, nous souhaitons mettre en avant cinq astuces efficaces et faciles à mettre en œuvre pour aider les établissements supérieurs et les groupes d'étudiants en soins de santé à accomplir leurs tâches administratives.

11.
Ann Am Thorac Soc ; 18(6): 955-962, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33321048

RESUMO

Rationale: Chronic obstructive pulmonary disease (COPD) is associated with abnormal skeletal muscle morphology and function. Objectives: To test the hypothesis that in vivo diaphragm muscle morphology assessed by computed tomography (CT) imaging would be associated with COPD severity, exacerbations, health status, and exercise capacity. Methods: The COPD Morphometry Study is a cross-sectional study that enrolled a clinical sample of smokers with COPD. Spirometry was performed and COPD severity was defined according to guidelines. Three-dimensional left hemidiaphragm morphology was segmented from contiguous axial CT images acquired at maximal inspiration, yielding quantitative measures of diaphragm CT density in Hounsfield units, dome height, and muscle volume. Exacerbations prompting pharmacotherapy or hospitalization in the preceding 12 months and St. George's Respiratory Questionnaire for COPD were assessed. Incremental symptom-limited cycle ergometry quantified peak oxygen uptake ([Formula: see text]o2Peak). Associations were adjusted for age, sex, body height, body mass index, and smoking status. Results: Among 65 smokers with COPD (75% male; [mean ± standard deviation (SD)] 56 ± 26 pack-years; forced expiratory volume in 1 second [FEV1] percentage predicted 55 ± 23%), mean diaphragm CT density was 3.1 ± 10 Hounsfield units, dome height was 5.2 ± 1.3 cm, and muscle volume was 57 ± 24 cm3. A 1-SD decrement in the diaphragm CT density was associated with 8.3% lower FEV1, 3.27-fold higher odds of exacerbation history, 9.7-point higher score on the St. George's Respiratory Questionnaire for COPD, and 2.5 ml/kg/min lower [Formula: see text]o2Peak. A 1-SD decrement in dome height was associated with 11% lower FEV1 and 1.3 ml/kg/min lower [Formula: see text]o2Peak. There were no associations with diaphragm volume observed. Conclusions: CT-assessed diaphragm morphology was associated with COPD severity, exacerbations, impaired health status, and exercise intolerance. The mechanisms and functional impact of lower diaphragm CT density merit investigation.


Assuntos
Diafragma , Doença Pulmonar Obstrutiva Crônica , Estudos Transversais , Diafragma/diagnóstico por imagem , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Doença Pulmonar Obstrutiva Crônica/diagnóstico por imagem , Tomografia Computadorizada por Raios X
12.
Biochim Biophys Acta Rev Cancer ; 1871(1): 192-198, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30599188

RESUMO

Stromal cells, deriving from mesenchymal stromal cells (MSCs), are crucial component of tumour microenvironment and represent key regulators of tumour processes. MSCs can be recruited to the tumour environment and interact with many cellular elements, thus influencing tumour biology. Cell-to-cell communication is in part mediated by the release of extracellular vesicle (EVs). EVs can induce significant molecular changes in recipient cells, delivering bioactive molecules. In this review, we describe the MSC-derived EVs content and discuss their role in different processes related to cancer biology. Furthermore, we summarize chemical or biological EVs modifications aiming to develop more efficient antitumor therapies.


Assuntos
Vesículas Extracelulares/metabolismo , Células-Tronco Mesenquimais/metabolismo , Neoplasias/patologia , Microambiente Tumoral/fisiologia , Animais , Comunicação Celular/fisiologia , Vesículas Extracelulares/patologia , Humanos , Células-Tronco Mesenquimais/patologia , Neoplasias/metabolismo
14.
Redox Biol ; 11: 469-481, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28086195

RESUMO

Zinc deficiency affects the development of the central nervous system (CNS) through mechanisms only partially understood. We previously showed that zinc deficiency causes CNS oxidative stress, damaging microtubules and impairing protein nuclear shuttling. STAT1 and STAT3 transcription factors, which require nuclear import for their functions, play major roles in CNS development. Thus, we investigated whether zinc deficiency disrupts STAT1 and STAT3 signaling pathways in the developing fetal CNS, characterizing the involvement of oxidative stress and the cytoskeleton in the adverse effects. Maternal (gestation day 0-19) marginal zinc deficiency (MZD) reduced STAT1 and STAT3 tyrosine phosphorylation and their nuclear translocation in the embryonic day 19 (E19) rat brain. Similar effects were observed in zinc depleted IMR-32 neuroblastoma cells, with an associated decrease in STAT1- and STAT3-dependent gene transactivation. Zinc deficiency caused oxidative stress (increased 4-hydroxynonenal-protein adducts) in E19 brain and IMR-32 cells, which was prevented in cells by supplementation with 0.5mM α-lipoic acid (LA). In zinc depleted IMR-32 cells, the low tyrosine phosphorylation of STAT1, but not that of STAT3, recovered upon incubation with LA. STAT1 and STAT3 nuclear transports were also restored by LA. Accordingly, chemical disruption of the cytoskeleton partially reduced STAT1 and STAT3 nuclear levels. In summary, the redox-dependent tyrosine phosphorylation, and oxidant-mediated disruption of the cytoskeleton are involved in the deleterious effects of zinc deficit on STAT1 and STAT3 activation and nuclear translocation. Therefore, disruption of the STAT1 and STAT3 signaling pathways may in part explain the deleterious effects of maternal MZD on fetal brain development.


Assuntos
Encéfalo/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT3/genética , Zinco/metabolismo , Animais , Encéfalo/crescimento & desenvolvimento , Sistema Nervoso Central/metabolismo , Sistema Nervoso Central/patologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Humanos , Oxirredução , Fosforilação , Transporte Proteico/efeitos dos fármacos , Ratos , Fator de Transcrição STAT1/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Ácido Tióctico/administração & dosagem , Ativação Transcricional/efeitos dos fármacos , Tirosina/metabolismo , Zinco/deficiência
16.
Food Funct ; 7(1): 84-92, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26645329

RESUMO

This paper investigated if marginal zinc nutrition during gestation could affect fetal exposure to glucocorticoids as a consequence of a deregulation of placental 11ßHSD2 expression. Placenta 11ß-hydroxysteroid dehydrogenase type 2 (11ßHSD2) plays a central role as a barrier protecting the fetus from the deleterious effects of excess maternal glucocorticoids. Rats were fed control (25 µg zinc per g diet) or marginal (10 µg zinc per g diet, MZD) zinc diets from day 0 through day 19 (GD19) of gestation. At GD19, corticosterone concentration in plasma, placenta, and amniotic fluid was similar in both groups. However, protein and mRNA levels of placenta 11ßHSD2 were significantly higher (25% and 58%, respectively) in MZD dams than in controls. The main signaling cascades modulating 11ßHSD2 expression were assessed. In MZD placentas the activation of ERK1/2 and of the downstream transcription factor Egr-1 was low, while p38 phosphorylation and SP-1-DNA binding were low compared to the controls. These results point to a central role of ERK1/Egr-1 in the regulation of 11ßHSD2 expression under the conditions of limited zinc availability. In summary, results show that an increase in placenta 11ßHSD2 expression occurs as a consequence of gestational marginal zinc nutrition. This seems to be due to a low tissue zinc-associated deregulation of ERK1/2 rather than to exposure to high maternal glucocorticoid exposure. The deleterious effects on brain development caused by diet-induced marginal zinc deficiency in rats do not seem to be due to fetal exposure to excess glucocorticoids.


Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 2/metabolismo , Fenômenos Fisiológicos da Nutrição Materna , Placenta/enzimologia , Zinco/deficiência , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/análise , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/genética , Animais , Dieta , Feminino , Expressão Gênica/fisiologia , Idade Gestacional , Glucocorticoides/análise , Masculino , Proteína Quinase 1 Ativada por Mitógeno/fisiologia , Proteína Quinase 3 Ativada por Mitógeno/fisiologia , Placenta/química , Gravidez , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Zinco/administração & dosagem , Proteínas Quinases p38 Ativadas por Mitógeno/fisiologia
17.
Mech Dev ; 107(1-2): 119-31, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11520668

RESUMO

We analyzed the influence of presenilins on the genetic cascades that control neuronal differentiation in Xenopus embryos. Resembling sonic hedgehog (shh) overexpression, presenilin mRNA injection reduced the number of N-tubulin+ primary neurons and modulated Gli3 and Zic2 according to their roles in activating and repressing primary neurogenesis, respectively. Presenilin increased shh expression within its normal domain, mainly in the floor plate, whereas an antisense X-presenilin-alpha morpholino oligonucleotide reduced shh expression. Both shh and presenilin promoted cell proliferation and apoptosis, but the effects of shh were widely distributed, while those resulting from presenilin injection coincided with the range of shh signaling. We suggest that presenilin may modulate primary neurogenesis, proliferation, and apoptosis in the neural plate, through the enhancement of shh signaling.


Assuntos
Proteínas de Membrana/genética , Proteínas do Tecido Nervoso , Neurônios/citologia , Proteínas Repressoras , Transativadores/genética , Proteínas de Xenopus , Xenopus laevis/embriologia , Secretases da Proteína Precursora do Amiloide , Animais , Apoptose , Ácido Aspártico Endopeptidases , Diferenciação Celular , Divisão Celular , Sistema Nervoso Central/embriologia , Proteínas de Ligação a DNA/genética , Regulação para Baixo , Embrião não Mamífero/citologia , Embrião não Mamífero/metabolismo , Endopeptidases/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteínas Hedgehog , Hibridização In Situ , Fatores de Transcrição Kruppel-Like , Proteínas de Membrana/fisiologia , Mutagênese Sítio-Dirigida , Oligonucleotídeos Antissenso , Presenilina-1 , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Transativadores/fisiologia , Fatores de Transcrição/genética , Tretinoína/farmacologia , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismo , Xenopus laevis/genética , Xenopus laevis/metabolismo , Proteína Gli3 com Dedos de Zinco
18.
Biotechniques ; 7(8): 830-8, 1989 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2698661

RESUMO

We developed a system for rapid, manual and automated sequence analysis by utilizing and modifying methods used in conjunction with the polymerase chain reaction (PCR). We are using these techniques to detect single base mutations in the dihydrofolate reductase (DHFR) gene giving rise to methotrexate (MTX) resistance of tumor cells obtained from patients with malignancies. Amplifying in vitro both genomic DNA and transcripts of the human DHFR we are able to reproducibly generate single-stranded templates. Utilizing [alpha-35S]dATP and both the universal and reverse sequencing primers we obtain sequence information from either strand. The methods described have been successfully used for automated sequencing with the Applied Biosystems Model 370A Sequencer using both modified T7 DNA polymerase and Taq I. DNA polymerase for dideoxy-termination sequencing. The use of this methodology to detect a single base change in a human colon carcinoma cell line, HCT-8, is illustrated.


Assuntos
Amplificação de Genes , Técnicas Genéticas , Metotrexato/farmacologia , Reação em Cadeia da Polimerase , Tetra-Hidrofolato Desidrogenase/genética , Adenocarcinoma/genética , Automação , Sequência de Bases , DNA/biossíntese , DNA de Cadeia Simples/síntese química , DNA Polimerase Dirigida por DNA , Resistência a Medicamentos/genética , Eletroforese em Gel de Ágar , Humanos , Dados de Sequência Molecular , Oligonucleotídeos/síntese química , Oligonucleotídeos/genética , RNA Mensageiro/isolamento & purificação , RNA Neoplásico/isolamento & purificação , Taq Polimerase , Células Tumorais Cultivadas
19.
Int J Dev Neurosci ; 4(6): 513-7, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3455609

RESUMO

Using catalase activity as a marker enzyme of microperoxisomes we determined the presence of these organelles in rat cerebral cortex (grey matter) and in brain stem (white matter) throughout development. While in grey matter the values of specific activity of catalase remained constant during all the period studied, in white matter the values increased up to 17 days of age, remained constant up to 31 days and decreased thereafter. Studies carried out in isolated oligodendroglial cells confirmed the results obtained in white matter. The results give support to the hypothesis of a possible relationship between the increase in the population of microperoxisomes and the appearance of myelin.


Assuntos
Envelhecimento/metabolismo , Tronco Encefálico/crescimento & desenvolvimento , Córtex Cerebral/crescimento & desenvolvimento , Microcorpos/fisiologia , Bainha de Mielina/fisiologia , Animais , Tronco Encefálico/metabolismo , Tronco Encefálico/fisiologia , Catalase/metabolismo , Córtex Cerebral/metabolismo , Córtex Cerebral/fisiologia , Feminino , Masculino , Microcorpos/enzimologia , Ratos , Ratos Endogâmicos
20.
IEEE Trans Med Imaging ; 6(3): 258-65, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-18244029

RESUMO

Statistical considerations on the precision in the determination of blood vessel dimensions from digitized cine angiographic images are described. The resolution requirements related to "point measurements" and segmental diameter curve evaluations are discussed. The error associated with inaccurate determination of the vessel's centerline is analyzed. The concepts have been implemented on a high-speed image analyzing system, which measures blood vessel diameters with advanced automation. The performance of the system was evaluated with blood vessel phantoms, ranging in diameter from 0.88 to 6.26 mm. For these phantoms the minimum measurable change in vessel dimension over 20-pixel (-1.1 mm) long segments ranged from 3.4 to 0.2 percent, respectively.

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