China
Africa
Explore chapters and articles related to this topic
Lysosomal Storage Disorders and Enzyme Replacement Therapy
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2020
Individuals with MPS II grow steadily until about age 5 and develop first features of this disease between ages 2 and 4 (full lips, large rounded cheeks, a broad nose, and an enlarged tongue, and frequent upper respiratory infections, due to airway narrowing). With disease progression nearly all organs and tissues become affected; this leads among others—apart from possible macrocephaly and hydrocephalus—to enlarged liver and spleen (hepatosplenomegaly), and enlarged heart (ventricular hypertrophy) due to heart valve abnormalities that may result in heart failure, too. Carpal tunnel syndrome (CTS) mediated by compression of the median nerve goes along with symptoms like pain, numbness, and tingling in fingers and the hands, and by narrowing the spinal canal the spinal cord becomes damaged (spinal stenosis). MPS II patients may also suffer from reduced vision and may develop hearing loss. Persons with this disease are of short stature (because growth slows beyond age 5), have joint deformities with the consequence of reduced mobility, and dysostosis multiplex which means severe abnormalities in development of skeletal cartilage and bone together with mental retardation. In patients with severe MPS II the disease progresses rapidly with loss of basic functional skills and mental retardation between ages 6 and 8 and the life expectancy is 10 to 20 years (Jones et al., 2009). Individuals with the mild form of MPS II may live into adulthood and their intelligence is not or comparatively slightly affected (Wraith et al., 2008; NIH, 2018, 2018).
Design and evaluation of the crimping of a hooked self-expandable caval valve stent for the treatment of tricuspid regurgitation
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
Gideon Praveen Kumar, Hwa Liang Leo, Fangsen Cui
The tricuspid valve consists of three leaflets that separates the right atrium from the right ventricle and maintains unidirectional blood flow. In addition to these, the leaflets, chordae tendinae, papillary muscles, fibrous annulus, the right atrial and ventricular myocardium make up the entire valvular complex (Séguéla et al. 2011). A disturbance of any of these structures may lead to tricuspid regurgitation (TR). With an increased volume of TR, cardiac output (CO) decreases and patients tend to develop symptoms of right heart failure with possible congestive hepatosplenomegaly, peripheral oedema and associated ascites (Filsoufi et al. 2005). Surgical correction with tricuspid valve repair or replacement which is the only corrective therapy available currently, carries an operative mortality of up to 22% in these patients, and is therefore not routinely offered (Lauten et al. 2010; Zhu et al. 2016). TR is more prevalent among the elderly which is also a concern as the patients are deemed high-risk for open heart valve replacement (Nkomo et al. 2006; Campelo-Parada et al. 2017). Thus, transcatheter tricuspid valve replacement offers a better prognosis for patients affected by TR (Muller et al. 2017). In this minimally invasive procedure, the transcatheter heart valve is crimped and inserted into the femoral vein via a small incision. The crimped valve is then moved to the heart using a delivery system. At the deployment site, which is the diseased tricuspid valve, the crimped valve re-expands to its pre-set diameter and become fully functional (Ismail et al. 2017).