Histology and histopathology Vol.13, nº 1 (1998)
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- PublicationOpen AccessThe cytoskeleton in skeletal, cardiac and smooth muscle cells(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 1998) Stromer, M. H.The muscle cell cytoskeleton consists of proteins or structures whose primary function is to link, anchor or tether structural components inside the cell. Two important attributes of the cytoskeleton are strength of the various attachments and flexibility to accommodate the changes in cell geometry that occur during contraction. In striated muscle cells, extramyofibrillar and intramyofibrillar domains of the cytoskeleton have been identifi ed , Evidence of the extramyofibrillar cytoskeleton is seen at the cytoplasmic face of the sa rcolemma in striated muscle where vinculin- and dystrophin-rich costameres adjacent to sarcomeric Z lines anchor intermedi a te filaments that span from peripheral myofibrils to the sarcolemma. Intermediate filaments also link Z lines of adjacent myofibrils and may, in some muscles, link successive Z lines within a myofibril at the surface of the myofibril. The intramyofibrillar cytoskeletal domain includes elastic titin filaments from adjacent sarcomeres that are anchored in the Z line and continue through the M line at the center of the sa rcomere; inelastic nebulin filaments also anchored in the Z line and co-extensible with thin filaments; the Z line, which also anchors thin filaments from adjacent sarcomeres; and the M line, which forms bridges between the centers of adjacent thick filaments, In smooth muscle, the cytoskeleton includes adherens junctions at the cytoplasmic face of the sarcolemma, which a nchor B-actin filaments and intermediate filaments of the cytoskeleton, and dense bodies in the cytoplasm, which also anchor actin filaments and intermediate filaments and which may be the interface between cytoskeletal and contractile elements.
- PublicationOpen AccessHistochemical and ultrastructural study of skeletal muscle in patients with sepsis and multiple organ failure syndrome (MOFS)(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 1998) Díaz, N. L.; Finol, H. J.; Torres, S. H.; Zambrano, C. I.; Adjounian, H.Muscle biopsies for histochemical and ultrastuctural analysis were obtained from seven critically ill patients admitted to the Intensive Care Unit of the "Domingo Luciani" Hospital, Caracas, Venezuela. The sample included two patients with sepsis of abdominal origin, and five that presented sepsis/MOFS, with renal, hepatic, and respiratory disturbances and muscular weakness. Sections were examined for myosin adenosine triphosphatase (ATPase) after pre-incubation with both acid buffer (pH 4.37 and 4.6) and alkaline buffer (pH 10.3), for reduced nicotinamide dinucleotide diaphorase (NADHd), and for a-glycerophosphate dehydrogenase (a-GPDH). Sections were stained with hematoxilin and eosin to look for pathological changes and examined with a transmission electron microscope. Skeletal muscle of patients in early stage of sepsis showed a normal aspect with light microscopy, but at the ultrastructural level some of the fibres showed atrophy and some capillaries looked altered . Patients with sepsis/MOFS exhibited an evident muscle disorder with oedema. infiltrate, atrophy and segmental necrosis. All fibre types showed decrease in diameter; specially fibre types IIA and lIB . Intramuscular capillaries were thickened and occluded , indexes of capillarity were slightly reduced, and fibre oxidative activity was decreased. At ultrastructural level fibres showed severe atrophy, contractile system disorganization and segmental necrosis. Capillaries were also altered and the mononuclear cell infiltrate was abundant and represented by macrophages. lymphocytes and mastocytes.
- PublicationOpen AccessHyperlipidemia and kidney disease: Concepts derived from histopathology and cell biology of the glomerulus(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 1998) Kamanna, V. S.; Roh, D. D.; Kirschenbaum, M. A.The association between hyperlipidemia and renal disease was noted by Virchow as earl y as the 19th ce ntury. Subseq ue ntl y, similar histopatho log ica l lipid depo siti o ns we re confirme d in diverse huma n a nd experimental renal diseases. Altho ugh, no studies have been established in man to suggest a causal re lationship between lipid s and the pathogenesis of rena l disease . compe llin g ev id e nce acc umul a te d in experimental animals suggests a direct role of lipids in the initiation and progression of glome rular disease. These studi es showed that cho lesterol-feed ing to various experimental animals induced the development of glomerul ar injury. Furthermore. the treatment of hype rlipidemic a nima ls with lipid lowering drugs prevented the deve lopment of glomenllosclerosis. In this article, we will rev iew recent advances made in understanding various aspects of lipid-mediated rena l injury inc ludin g bioc he mi ca l mec ha nisms of hype rlipidemia, a possible direct role of hyperlipidemi a in the pa th oge nesis o f ren a l disease, pathobiological acc umulation of lipids and lipoprote ins, biochemi cal and histological similarities between systemic atherosclerosis and glomerulosclerosis, and cellular processes invo lved in the development of glomerul ar disease. Furthermore, we will define cellular and mo lecul ar hypotheses that provide putative mechanisms by which hyperlipidemia a nd a theroge ni c lipo pro tei ns indu ce se ri es o f cy toregulatory peptide- med iated eve nts in vo lved in the development of glomerul ar disease.
- PublicationOpen AccessParacrine control of steroid hormone secretion by chromaffin cells in the adrenal gland of lower vertebrates(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 1998) Mazzocchi, G.; Gottardo, G.; Nussdorfer, G. G.The adrenal glands of lowe r vertebrates display a notable intermingling between steroidogenic and chromaffin tissues, which increases from Pisces to Al'es. As in mammals, adrenal chromaffin cells contain and release, in addition to catechol amines, serotonin and several peptides, which may affect the secretory acti vity of steroidogeni c cells in a paracrine manner. Stimulatory molec ul es in c lud e se roto nin , arg inin e-va so tocin. tachykinin s, vasoac ti ve intestinal peptide , pituita ry adenylate cyclase-acti vating peptide and calcitonin generelated peptide: inhibitory molec ul es are dopamine, somatotropic hormone-release inhibiting hormone and ga lanin . Epin ephrine and no repinephrine appe ar to stimulate steroid sec retion in Aves and to inhibit it in Pisces, while their ac tion in Amphibia is controversial. Likewise . atri a l natriureti c peptide exe rts an antisec re ta gog ue ac ti o n in Amphibia and a ma rk ed secretagogue effe ct in Pisces and Aves. The effects of opioids (enkephalins and endorphins) have scarcely been in vesti ga ted a nd th e findin gs obt a ined a re hi g hly qu esti o nabl e. Compared with the ama zin g ma ss of in vestigations carried out in mammals, studies in lower ve rtebrates a re few, and in large part pe rformed in Amphibia and Al'es. It appears that much further work has to be done by comparati ve endocrinologists to fully clari fy the physiolog ica l relevance of th e functi onal interactions between chromaffin and steroidogeni c cells in the adrenal glands of lower vertebrates.
- PublicationOpen AccessPresence of pigment in the ovine pineal gland during embryonic development(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 1998) Regodón, S.; Franco, A. J.; Gazquez, A.; Redondo, E.Light- and electron-mi croscopi c analyses were used 10 id entify and desc ribe th e charac teristi c features of cells containing pigment in the ov ine pineal gland during prenatal deve lopment. 72 ov ine embryos (36 male, 36 female) ranging in age from 54 to 150 days were used fo r this study. Ce lls co nt aining pigment granules were a constant fea ture in this gland . Wh en samples from the di f'ferent groups were inspected using the naked eye, the detection of pigment was of 61 % in groups I (54 to 67 days of prenatal development) and II (7 1 to 92 days of prenatal development), ~3 % in group III (9t; to 113 days of prenatal development) and 25% in gro up IV (II R to 150 days of prenatal deve lopment). The morphologica l featu res and histochemical properties of the pineal pigment enab led it to be identified as me lanin . Several types o f pigme nt granules were ultrastru cturall y distinguished; th ese varied in size, shape and loca tion within pinea l cell populations. The pigment g ranul es were de tec ted in pine alocy te s, interstitial cells and pigmented ce lls. The largest amount and the widest variety of pigmented granules were found in pigment ed ce lls. The prese nce of cells containing pigmented gra nules amongst the cell populations of the developing ov in e pineal gland was a nal ysed a nd compared with that of other mammalian species.