Histology and histopathology Vol. 9, nº 3 (1994)
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- PublicationOpen AccessRetinal pigment epithelial fine structure in the short-tailed stingray. Dasyatis brevicaudata(Murcia : F. Hernández, 1994) Braekevelt, Charlie R.The retinal pigment epithelium (RPE), choriocapillaris and Bruch's membrane (complexus basalis) have been studied by light and electron microscopy in the short-tailed stingray (Dasyatis brevicaudata). The RPE consists of a single layer of cuboidal cells which display numerous basal (choroidal) infoldings as well as many apical (vitreal) processes which interdigitate with photoreceptor outer segments. The lateral cell borders are relatively smooth and joined by a series of tight junctions. Within these epithelial cells, smooth endoplasmic reticulum is the dominant organelle with only scattered profiles of rough endoplasmic reticulum. Polysosomes, mitochondria and phagosomes are abundant. Melanosomes are totally absent over the tapetum and are scarce in non-tapetal locations. The RPE nucleus is large, vesicular and centrally located. Rruch's membrane is a pentalaminate structure. The choriocapillaris is a single layer of large capillaries. The endothelium of these capillaries is typically thin but only minimally fenestrated.
- PublicationOpen AccessThe use of fluorescent dextrans as a marker of sarcolemmal injury(Murcia : F. Hernández, 1994) Carter, G.T.; Kikuchi, N.; Horasek, S.J.; Walsh, S.A.We investigated the use of intravenously injected fluorescent dextran molecules (FDx) as a histological marker of sarcolemmal injury. Using fluorescent microscopy, uptake of FDx (average MW 10 kD) was assessed in sections of quadriceps muscles from three models: l ) normal (C57BLlIOSnJ) mice. 2) normal mice run downhill (0, 3, and 7 days post exercise), and 3) non-exercised mdx (dystrophin-deficient) mice. These were compared to serial sections stained with hematoxylin and eosin (H&E). In control muscles. strong fluorescence was seen between fibers (intercellular). Intracellular FDx was observed within cells of the quadriceps from normal mice run downhill at days 0 and 3 post exercise, but not at day 7. On H&E staining. muscle pathology was not observed until day 3, with regeneration by day 7. Intracellular FDx was also observed within mdx muscles, particularly in fibers that appeared pre-necrotic on H&E stained sections. FDx appears to be useful as a histological marker of changes in sarcolemmal integrity associated with muscle injury from eccentric exercise or muscle disease.
- PublicationOpen AccessHirschsprung's disease - immunohistochemical findings(Murcia : F. Hernández, 1994) Larsson, L.T.Hirschsprung's disease (HSCR) is characterized by a non-propulsive distal intestinal segment (usually colon) leading to a functional obstruction. An absence of ganglia in the affected - - segment explains the synonymous term ccaganglionosis coli,,. The lack of peristalsis is partly due to a deficient intestinal smooth muscle relaxation based on an absence of non-adrenergic, non-cholinergic (NANC) inhibitory innervation. Morphological studies using conventional microscopy, imrnunohistochemistry and immunochemistry against general neuronal markers and neuropeptides have been used to characterize the disturbed NANC innervation in HSCR. An increased cholinergic and adrenergic innervation is registered in the aganglionic segment in spite of the lack of neuronal cell bodies: Neuropeptides like vasoactive intestinal peptide (VIP), pituitary adenylate cyclase-activating polypeptide (PACAP), gastrin-releasing peptide (GRP), calcitonin generelated peptide (CGRP), substance P (SP), enkephalins and galanin imrnunoreactive nerve fibres are all reduced in number i n the aganglionic segment. In contrast, neuropeptide Y (NPY)-containing nerve fibres are increased in number in the diseased segment, probably reflecting the adrenergic hyperinnervation. General neuronal markers including chromogranins have been used to map the ne~lron~l network in the HSCR intestine and also to investigate the endocrine cell system in the intestinal mucosa. Nitric oxide is a potent component of the NANC inhibitory innervation and its synthesizing enzyme, nitric oxide synthase (NOS). is shown to be almost absent in the neuronal system in aganglionic intestine.
- PublicationOpen AccessDifferentiation of human lymphocytes into nuclear vlimata by meiosis. The cytotoxic effect of calcium-activated neutral proteinase inhibitor(Murcia : F. Hernández, 1994) Logothetou-Rella, H.Phytohaemagglutinin (PHA)-activated lymphocytes differentiated into nuclear vlimata (NVs) in vitro. Lymphocyte attachment was followed by formation and extrusion of cytoplasmic vesicles. nuclear elongation and fragmentation into NVs. NVs and cytoplasmic vesicles were detached and organized into large cell nodules in suspension. Immunocytochemistry showed that T-lymphocytes differentiated mainly to NVs while B-lymphocytes to buds. During differentiation there was a loss or gain of T-antigenicity by either mother or daughter cell. Cytogenetic analysis by chromosomal spreading and in situ techniques showed that NVs do carry chromosomes of hypodiploid or hypohaploid sets. NVs were the result of meiosis stimulated by PHA. A ly~nphocyticp opulation exhibited diploidies attributed to mitosis or symmetrical meiosis and hypodiploidies, hypohaploidies attributed to meiosis. A comparison between NVs and spermatozoa was provided. The inhibitor of calcium-activated neutral proteinase (CANP-I) was cytotoxic to NVs without interfering with NV production. A model was proposed for the action of CANP-I which is a promising agent against autoimmune diseases.
- PublicationOpen AccessThe contribution of cavernous body biopsy in the diagnosis and treatment of male impotence(Murcia : F. Hernández, 1994) Malovrouvas, D.; Petraki, C.; Constantinidis, E.; Petraki, K.; Antoniadis, G.; Constantinidis, C.; Kranidis, A.This study concerns the results of penile biopsies in 50 patients aged 27 to 80, with secondary impotence removed with a biopty gun or during penile surgery. The biopty gun specimens were equally representative as the open biopsy ones. The cause and the degree of erectile dysfunction were determined by clinical and laboratorial investigation. The histological study of the cavernous bodies in the patients with psychogenic impotence revealed normal erectile tissue. In patients with organic impotence, histological lesions were graded as mild, moderate or severe. The most severe lesions were observed in the erectile tissue and in particular in the smooth muscle of the trabeculae and the helicine arteries, which had been reduced and replaced by connective tissue. Histological lesions were found not only in the arterial but also in the venous leak cases. There was a correlation between their severity and the degree of impotence, although of no statistical significance. The penile biopsy determines the condition (state) of the functional cavernous smooth muscle tissue, the integrity of which is essential for the erectile mechanism as well as for the action of the vasoactive drugs and the results of vascular surgery. Its important role is evident as it contributes not only to the diagnosis of the cause, but also to the choice of treatment of male impotence.