排序方式: 共有55条查询结果,搜索用时 18 毫秒
1.
Cementum and dentin in hypophosphatasia 总被引:2,自引:0,他引:2
van den Bos T Handoko G Niehof A Ryan LM Coburn SP Whyte MP Beertsen W 《Journal of dental research》2005,84(11):1021-1025
Hypophosphatasia (HPP) often leads to premature loss of deciduous teeth, due to disturbed cementum formation. We addressed the question to what extent cementum and dentin are similarly affected. To this end, we compared teeth from children with HPP with those from matched controls and analyzed them microscopically and chemically. It was observed that both acellular and cellular cementum formation was affected. For dentin, however, no differences in mineral content were recorded. To explain the dissimilar effects on cementum and dentin in HPP, we assessed pyrophosphate (an inhibitor of mineralization) and the expression/activity of enzymes related to pyrophosphate metabolism in both the periodontal ligament and the pulp of normal teeth. Expression of nucleotide pyrophosphatase phosphodiesterase 1 (NPP1) in pulp proved to be significantly lower than in the periodontal ligament. Also, the activity of NPP1 was less in pulp, as was the concentration of pyrophosphate. Our findings suggest that mineralization of dentin is less likely to be under the influence of the inhibitory action of pyrophosphate than mineralization of cementum. 相似文献
2.
Walter J Paulus Carsten Tsch?pe John E Sanderson Cesare Rusconi Frank A Flachskampf Frank E Rademakers Paolo Marino Otto A Smiseth Gilles De Keulenaer Adelino F Leite-Moreira Attila Borbély István Edes Martin Louis Handoko Stephane Heymans Natalia Pezzali Burkert Pieske Kenneth Dickstein Alan G Fraser Dirk L Brutsaert 《European heart journal》2007,28(20):2539-2550
Diastolic heart failure (DHF) currently accounts for more than 50% of all heart failure patients. DHF is also referred to as heart failure with normal left ventricular (LV) ejection fraction (HFNEF) to indicate that HFNEF could be a precursor of heart failure with reduced LVEF. Because of improved cardiac imaging and because of widespread clinical use of plasma levels of natriuretic peptides, diagnostic criteria for HFNEF needed to be updated. The diagnosis of HFNEF requires the following conditions to be satisfied: (i) signs or symptoms of heart failure; (ii) normal or mildly abnormal systolic LV function; (iii) evidence of diastolic LV dysfunction. Normal or mildly abnormal systolic LV function implies both an LVEF > 50% and an LV end-diastolic volume index (LVEDVI) <97 mL/m(2). Diagnostic evidence of diastolic LV dysfunction can be obtained invasively (LV end-diastolic pressure >16 mmHg or mean pulmonary capillary wedge pressure >12 mmHg) or non-invasively by tissue Doppler (TD) (E/E' > 15). If TD yields an E/E' ratio suggestive of diastolic LV dysfunction (15 > E/E' > 8), additional non-invasive investigations are required for diagnostic evidence of diastolic LV dysfunction. These can consist of blood flow Doppler of mitral valve or pulmonary veins, echo measures of LV mass index or left atrial volume index, electrocardiographic evidence of atrial fibrillation, or plasma levels of natriuretic peptides. If plasma levels of natriuretic peptides are elevated, diagnostic evidence of diastolic LV dysfunction also requires additional non-invasive investigations such as TD, blood flow Doppler of mitral valve or pulmonary veins, echo measures of LV mass index or left atrial volume index, or electrocardiographic evidence of atrial fibrillation. A similar strategy with focus on a high negative predictive value of successive investigations is proposed for the exclusion of HFNEF in patients with breathlessness and no signs of congestion. The updated strategies for the diagnosis and exclusion of HFNEF are useful not only for individual patient management but also for patient recruitment in future clinical trials exploring therapies for HFNEF. 相似文献
3.
Emmy Manders Harm-Jan Bogaard M. Louis Handoko Marielle C. van de Veerdonk Anne Keogh Nico Westerhof Ger J.M. Stienen Cristobal G. dos Remedios Marc Humbert Peter Dorfmüller Elie Fadel Christophe Guignabert Jolanda van der Velden Anton Vonk-Noordegraaf Frances S. de Man Coen A.C. Ottenheijm 《Journal of the American College of Cardiology》2014
Background
After lung transplantation, increased left ventricular (LV) filling can lead to LV failure, increasing the risk of post-operative complications and mortality. LV dysfunction in pulmonary arterial hypertension (PAH) is characterized by a reduced LV ejection fraction and impaired diastolic function.Objectives
The pathophysiology of LV dysfunction in PAH is incompletely understood. This study sought to assess the contribution of atrophy and contractility of cardiomyocytes to LV dysfunction in PAH patients.Methods
LV function was assessed by cardiac magnetic resonance imaging. In addition, LV biopsies were obtained in 9 PAH patients and 10 donors. The cross-sectional area (CSA) and force-generating capacity of isolated single cardiomyocytes was investigated.Results
Magnetic resonance imaging analysis revealed a significant reduction in LV ejection fraction in PAH patients, indicating a reduction in LV contractility. The CSA of LV cardiomyocytes of PAH patients was significantly reduced (∼30%), indicating LV cardiomyocyte atrophy. The maximal force-generating capacity, normalized to cardiomyocyte CSA, was significantly reduced (∼25%). Also, a reduction in the number of available myosin-based cross-bridges was found to cause the contractile weakness of cardiomyocytes. This finding was supported by protein analyses, which showed an ∼30% reduction in the myosin/actin ratio in cardiomyocytes from PAH patients. Finally, the phosphorylation level of sarcomeric proteins was reduced in PAH patients, which was accompanied by increased calcium sensitivity of force generation.Conclusions
The contractile function and the CSA of LV cardiomyocytes is substantially reduced in PAH patients. We propose that these changes contribute to the reduced in vivo contractility of the LV in PAH patients. 相似文献4.
Dal Canto Elisa Remmelzwaal Sharon van Ballegooijen Adriana Johanne Handoko M. Louis Heymans Stephane van Empel Vanessa Paulus Walter J. Nijpels Giel Elders Petra Beulens Joline WJ 《Heart failure reviews》2022,27(1):207-218
Heart Failure Reviews - This study aimed to evaluate the diagnostic performance of echocardiographic markers of heart failure with preserved ejection fraction (HFpEF) and left ventricular diastolic... 相似文献
5.
6.
Handoko ML Schalij I Kramer K Sebkhi A Postmus PE van der Laarse WJ Paulus WJ Vonk-Noordegraaf A 《Pflügers Archiv : European journal of physiology》2008,455(5):951-959
Implantable radio-telemetry methodology, allowing for continuous recording of pulmonary haemodynamics, has previously been
used to assess effects of therapy on development and treatment of pulmonary hypertension. In the original procedure, rats
were subjected to invasive thoracic surgery, which imposes significant stress that may disturb critical aspects of the cardiovascular
system and delay recovery. In the present study, we describe and compare the original trans-thoracic approach with a new,
simpler trans-diaphragm approach for catheter placement, which avoids the need for surgical invasion of the thorax. Satisfactory
overall success rates up to 75% were achieved in both approaches, and right ventricular pressures and heart and respiratory
rates normalised within 2 weeks. However, recovery was significantly faster in trans-diaphragm than in trans-thoracic operated
animals (6.4 ± 0.5 vs 9.5 ± 1.1 days, respectively; p < 0.05). Stable right ventricular pressures were recorded for more than 4 months, and pressure changes, induced by monocrotaline
or pulmonary embolisms, were readily detected. The data demonstrate that right ventricular telemetry is a practicable procedure
and a useful tool in pulmonary hypertension research in rats, especially when used in combination with echocardiography. We
conclude that the described trans-diaphragm approach should be considered as the method of choice, for it is less invasive
and simpler to perform.
Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users. 相似文献
7.
8.
Maureen Handoko Lisa T. Emrick Jill A. Rosenfeld Xia Wang Alyssa A. Tran Alicia Turner John W. Belmont Undiagnosed Diseases Network Brendan H. Lee Carlos A. Bacino Hsiao‐Tuan Chao 《American journal of medical genetics. Part A》2019,179(3):475-479
Genetic alterations leading to overactivation of mammalian target of rapamycin (mTOR) signaling result in brain overgrowth syndromes such as focal cortical dysplasia (FCD) and megalencephaly. Megalencephaly with cutis tri‐color of the Blaschko‐linear type pigmentary mosaicism and intellectual disability is a rare neurodevelopmental disorder attributed to the recurrent mosaic c.5930C > T (p.Thr1977Ile) MTOR variant. This variant was previously reported at low to intermediate levels of mosaicism in the peripheral blood of three unrelated individuals with consistent clinical findings. We report a fourth case of a 3‐year‐old female presenting with megalencephaly, obstructive hydrocephalus due to cerebral aqueductal stenosis, asymmetric polymicrogyria, dysgenesis of the corpus callosum, hypotonia, developmental delay, and cutaneous pigmentary mosaicism. Oligonucleotide and SNP chromosomal microarray (CMA), karyotype, and trio whole exome sequencing (WES) in the peripheral blood, as well as a targeted gene variant panel from fibroblasts derived from hyperpigmented and non‐hyperpigmented skin did not detect any abnormalities in MTOR or other genes associated with brain overgrowth syndromes. Unlike the previously reported cases, the de novo c.5930C > T (p.Thr1977Ile) MTOR variant was detected at 32% mosaicism in our patient only after WES was performed on fibroblast‐derived DNA from the hyperpigmented skin. This case demonstrates the tissue variability in mosaic expression of the recurrent p.Thr1977Ile MTOR variant, emphasizes the need for skin biopsies in the genetic evaluation of patients with skin pigmentary mosaicism, and expands the clinical phenotype associated with this pathogenic MTOR variant. 相似文献
9.