Browsing by Subject "Capillaries"

Now showing 1 - 3 of 3
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    Microvascular pathology in Friedreich cardiomyopathy.
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Koeppen, Arnulf H.; Qian, Jiang; Travis, Alicia M.; Sossei, Alyssa B.; Feustel, Paul J.; Mazurkiewic, Joseph E.
    Heart disease is an integral part of Friedreich ataxia (FA). In addition to cardiomyocyte hypertrophy, fiber necrosis, and inflammatory infiltration, sections show fibrosis and disorganized capillaries. We examined the left ventricular wall (LVW) of 41 homozygous and 2 compound heterozygous FA patients aged 10-87 and 21 controls aged 2-69. Immunohistochemistry with an antibody to CD34 allowed quantitative counts of capillary profiles for a comparison with cardiomyocyte counts in the same field. Capillary counts (mean±standard deviation [SD]) in normal controls were 1926±341/mm2, while mean cardiomyocyte counts were 2003±686/mm 2 . The median ratio of capillaries to cardiomyocytes was 1.0 (interquartile range [IQR]: 0.9- 1.2). In FA, the number of cardiomyocytes/mm 2 was significantly less (704±361; p<0.001), and the median ratio of capillaries to heart fibers was 2.0 (IQR:1.4-2.4). There was a significant correlation of the expanded guanine-adenine-adenine trinucleotides (shorter allele, GAA1) with a younger age of onset, shorter disease duration, and lower cardiomyocyte counts. The ratio of capillaries to heart fibers was higher in patients with long GAA1 repeat expansions (e.g., 3.31 in GAA1 of 1200). Double-label immunofluorescence for CD34 and the fibroblast marker S100A4 revealed co-expression in endothelial cells, supporting endothelial-to- mesenchymal transition in the pathogenesis of cardiac fibrosis in FA. We propose that the pathogenesis of FA heart disease includes primary fibrosis.
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    The permeability of capillaries among the small granule-containing cells in rat superior cervical ganglia, an ultrastructural lanthanum tracer study
    (Murcia : F. Hernández, 1991) Yat-Pang Chau; Chung-Liang Chien; Kuo-Shyan Lu
    The permeability of blood capillaries associated with small granule-containing (SGC) cells in rat superior cervical ganglia was investigated at ultrastructural level by employing ionic lanthanum as an electron dense tracer. In rat superior cervical ganglia, the majority of blood capillaries were nonfenestrated. Both fenestrated and nonfenestrated capillaries were observed in the area associated with SGC cells. Lanthanum tracer was observed in the lumina1 surface, the interendothelial cleft and the subendothelial perivascular spaces of both fenestrated and nonfenestrated capillaries associated with SGC cells. The external lamina of the Schwann cell which surrounded the neurons, nerve fibres and SGC cells were clearly delineated by the lanthanum tracer. Furthermore, the perineuronal space, the periaxonal space, and the pericellular space of the SGC cells were readily accessible to the lanthanum ion. The results demonstrated an absence of blood-nerve barrier, bloodganglionic and blood-SGC cell barrier to the lanthanum ion in the parenchyma1 area of the SGC cells in rat superior cervical ganglia. It is proposed that lanthanum may pass through the endothelial cells via 1) the fenestrae of fenestrated capillaries, 2) the intercellular junctions of both fenestrated and nonfenestrated capillaries, i.e., a paracellular pathway; and 3) the process of endocytosislexocytosis, i.e., a transcellular pathway. to reach the subendothelial space and be distributed in the parenchyma of SGC cells in rat superior cervical ganglia.
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    Ultrastructural characteristics of blood vessels in the infant and adult human cerebral cortex
    (Murcia : F. Hernández, 1997) Zhang, H.F.; Ong, W.Y.; Leong, S.K.; Garey, L.J.
    Blood vessels in frontal and temporal cerebral cortex of adults and two infants aged 5 months and 5 years were studied by electron microscopy. The cells outside the endothelium were classified on their ultrastructural characteristics. Fibroblasts had prominent rough endoplasmic reticulum and few mitochondria in the cytoplasm. They were different from pericytes, which contained a prominent Golgi apparatus but only a few, isolated profiles of rough endoplasmic reticulum. Smooth muscle cells were distinguished from fibroblasts and pericytes by the presence of filaments and caveolae. Perivascular cells were characterised by the presence of lysosomes and granules of different sizes and electron densities, and were present at al1 ages studied. Plasma cells had abundant rough endoplasmic reticulum in the cytoplasm, and were present only in the 5-month-old infant cortex. Cortical vessel diameter increased with age.