Publications by authors named "Steven Kroon"

Haploinsufficiency for Endoglin (ENG) and activin A receptor type II-like I (/ALK1) lead to the formation of weak and abnormal vessels in hereditary hemorrhagic telangiectasia (HHT). These cause epistaxis (nosebleeds) and/or gastrointestinal blood loss. In vitro in cultured endothelial cells, tacrolimus has been shown to increase ENG and ALK1 expression.

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Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease in which gastrointestinal bleeding is a rare presenting symptom in children. Gastrointestinal bleeding in children is treated locally by endoscopy. When a focus of bleeding cannot be reached by endoscopy, management of these patients can be challenging.

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Treatment with neurotrophins prevents degeneration of spiral ganglion cells (SGCs) after severe hair cell loss. In a previous study we demonstrated a long-lasting effect with brain-derived neurotrophic factor (BDNF) after cessation of treatment. In that study the survival of the SGC cell bodies was examined.

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Hereditary hemorrhagic telangiectasia (HHT), an autosomal dominant disease, is characterized by telangiectases and arteriovenous malformations (AVMs). Untreated AVMs, especially in the lungs-pulmonary AVMs (PAVMs)-can result in morbidity with a decreased life expectancy. We have investigated whether HHT patients, systematically screened for HHT-related organ involvement and treated if needed, have a similar survival as persons without HHT.

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Aims: Transthoracic contrast echocardiography (TTCE) is the recommended screening tool to detect pulmonary right-to-left shunt (RLS) caused by pulmonary arteriovenous malformations (PAVMs). We assessed a novel method to quantify the RLS using the change in echo density (ED) following contrast injection.

Methods And Results: An analysis of 437 consecutive patients [58% female, 47 years, interquartile range (IQR) 33-60] who underwent TTCE for the detection of a pulmonary RLS.

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Abnormal vasculature is a key feature of hereditary hemorrhagic telangiectasia (HHT) and can also present in the nail fold capillary beds. However, the exact prevalence and the clinical diagnostic value in HHT are still largely unknown. The nail fold can be easily and noninvasively inspected with a capillary microscope.

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Background: Hereditary Hemorrhagic Telangiectasia type 2 (HHT2) is an inherited genetic disorder characterized by vascular malformations and hemorrhage. HHT2 results from ACVRL1 haploinsufficiency, the remaining wild-type allele being unable to contribute sufficient protein to sustain endothelial cell function. Blood vessels function normally but are prone to respond to angiogenic stimuli, leading to the development of telangiectasic lesions that can bleed.

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Purpose Of Review: Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant inherited disease characterized by telangiectasia and arteriovenous malformations (AVMs). To date, five genetic types of HHT and one combined juvenile polyposis syndrome and HHT are known. Clinical and genetic screening of patients suspected with HHT is recommended to confirm the diagnosis and to prevent complications associated with HHT.

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Damage to and loss of the organ of Corti leads to secondary degeneration of the spiral ganglion cell (SGC) somata of the auditory nerve. Extensively examined in animal models, this degeneration process of SGC somata following deafening is well known. However, degeneration of auditory nerve axons, which conduct auditory information towards the brainstem, and its relation to SGC soma degeneration are largely unknown.

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