Lymphatic vessels in human eyelids: an immunohistological study in dermatochalasis and chalazion.

We investigated lymphatic morphology and expression of endothelin (ET-1) axis molecules in human eyelids affected by an inflammatory state (chalazion) and an age-related degenerative condition (dermatochalasis). Lymphatics were immunohistologically detected by D2-40/LYVE-1 staining. Absorbing lymphatic vessels were localized in papillary dermis and around skin appendages with distinctive morphology. In chalazion, D2-40 reactive flattened lymphatic profiles were compressed by inflammatory infiltrate; in dermatochalasis, large fully opened lymphatics were observed, with a significantly wider total area (lymphatic lumina/200x field; p < 0.05). The lymphatic density (number/200x field) in the two groups was within the same range. Lymphatic dilation is possibly dependent on reduction and fragmentation of the dermal elastic network as well as of oxytalanic fibers in the papillary dermis of dermatochalasis, as shown by Weigert's reaction. Multifunctional peptide ET-1, involved in vasomotion, inflammation and connective proliferation, was faintly and discontinuously localized on lymphatics, as was its type A receptor. In contrast, the consistent expression of type B receptor indicates that lymphatic endothelium is a physiological target for ET-1, whose effects are modulated by multiple pathophysiological conditions. Thus, vasoactive factors play a role in the physiology of richly vascularized eyelids, and therefore, morphofunctional characterization of lymphatic vessels may be useful in suggesting treatment options.

Lymphatic vessels in human sural nerve: immunohistochemical detection by D2-40.

Lymphatics were detected in the epineurium of the human sural nerve by D-240 immunostaining and confirmed by ultrastructural examination.

Type 3 (chronic) GM1 gangliosidosis presenting as infanto-choreo-athetotic dementia, without epilepsy, in three sisters.

Three sisters (ages 27, 24, and 17 years) presented with slowly progressing dystonic dementia and spastic tetraparesis with infantile onset. CSF, bone marrow, and conjunctival cells showed storage vacuoles. Biochemical analysis revealed increased urinary oligosaccharide excretion and decreased activity of acid beta-D-galactosidase and beta-D-fucosidase in serum, leukocytes, and cultured fibroblasts. The parents' enzyme values were in the heterozygous range. This is the only case in the literature of severe dementia associated with the clinical symptoms of type 3 GM1 gangliosidosis. The clinical heterogeneity of GM1 gangliosidosis and the significance of the combination of beta-D-galactosidase and beta-D-fucosidase defects in this syndrome are discussed.

Smooth muscle cells of the media in the dilatative pathology of ascending thoracic aorta: morphology, immunoreactivity for osteopontin, matrix metalloproteinases, and their inhibitors.

The etiopathogenesis of thoracic aortic aneurysms is currently an issue of debate. The present study investigated ultrastructural, morphometric, and immunohistochemical aspects of smooth muscle cells (SMCs) in chronic aneurysm of the thoracic aorta (aneurysm group), aortic dilatation associated with valvular disease (valvular group), and dissection of the thoracic aorta (dissection group). Fragments of the ascending aorta that had been taken from the patients during coronary bypass surgery were used as controls. No significant difference was observed in the density of SMCs between the 3 pathologic groups put together and the controls. Only separate analysis of SMC density in each of the pathologic groups showed that the valvular group samples had significantly smaller amounts of SMCs in the internal layer of the media than the dissection group samples and controls. Ultrastructural analysis, in situ end labeling, propidium iodide assay, and DNA laddering did not show apoptosis of SMCs in the samples investigated. Ultrastructure of SMCs characteristic of the synthetic phenotype, together with increased expression of osteopontin in the media of pathologic thoracic aortas indicated the transition of SMCs from the contractile to the synthetic phenotype. Immunohistochemical investigation showed that medial SMCs in the samples taken from aortas of all 3 pathologic groups expressed stronger immunoreactivity for matrix metalloproteinase 1, 2, and 9 and tissue inhibitor of metalloproteinase 1 and 2 than the controls. The present study shows that during the formation of aneurysms, dissection of the thoracic aorta, or aortic dilatation associated with valvular disease, loss of SMCs was not of great importance with respect to their transition from the contractile to the synthetic type in leading to increased production of matrix metalloproteinases.

A new model for studying differentiation and growth of epidermal cultures on hyaluronan-based carrier.

Here, a three-dimensional model based on fragments of human de-epidermized dermis (DED) is prepared in order to study the performance of a microperforated, hyaluronan-based membrane as a carrier of cultured epidermal cells. Hyaluronic acid is, in fact, considered to be an optimal biomaterial allowing proliferation of both keratinocytes and melanocytes, and it is already used for clinical aims. The carrier with subconfluent human epidermal cultures is positioned onto the DED and kept in culture until a new epidermis is formed. This model system allowed to study the migration and growth of human epidermal cells from the carrier, resembling 'in vivo' re-epithelization.

Endogenous codeine and morphine are stored in specific brain neurons.

Codeine and morphine have been detected in mammalian brain by radioimmunoassay (RIA), and in brain and other tissues by gas-chromatography/mass-spectrometry (GCMS) in different laboratories. It has been also shown that rat liver can synthesize the skeleton of the morphine molecule, thus suggesting that this alkaloid, which is the prototype of mu-receptor agonists, plays a physiological role in brain. We report the presence of morphine-like immunoreactive compounds inside the cell body, fibers and terminals of neurons in different brain areas. Moreover, neurons localized in the same brain areas were capable of accumulating and storing [3H]morphine slowly infused intracerebroventricularly (i.c.v.) through an osmotic minipump.

Ultrastructural observations in lichen nitidus.

Lichen nitidus (LN) and lichen planus (LP) are considered by some investigators to be two variants of the same disease, and by others to be two distinct dermatoses. In order to obtain further information about the relationship between LN and LP we examined the ultrastructure of lesions from two LN patients. In the central part of the lesion, the basement membrane was absent, or was interrupted by migrating phagocytes or lymphocytes. The basal cells and the lower cells of the stratum spinosum exhibited karyolysis and appeared to be compressed and often necrotic. In the upper dermis irregular cell debris full of clumps of tonofilaments and colloid-body-like structures was observed. A dense dermal infiltrate of macrophages, lymphocytes, fibrocytes, and Sezary-like cells was present. Signs of cooperation between lymphocytes and macrophages were also evident. The periphery of the lesion showed no pathological features except for enlargement of the intercellular spaces and the presence of mononuclear cells scattered through the epidermis. Several normal Langerhans cells were noticed. These ultrastructural findings were quite similar to those reported for LP.

Mid-dermal elastolysis: an ultrastructural and biochemical study.

Mid-dermal elastolysis (MDE) is a particular elastic tissue disorder in which selective loss of elastic fibres occurs in the mid-dermis. It is clinically characterized by the appearance of fine wrinkling of the epidermis and perifollicular protrusion which gives the skin an aged appearance. It is sometimes associated with an inflammatory event such as urticaria while other cases are regarded as idiopathic. The pathogenesis of MDE is still obscure. Some authors have underlined the role of macrophage activation and others have imputed UV radiation. We report here a typical case of MDE arising after several attacks of solar urticaria. Electron microscopic and biochemical studies were carried out. Ultrastructural examination showed active elastophagocytosis by macrophages and mast cells, often degranulated, near phagocytosing cells. Biochemical studies demonstrated that fibroblasts derived from lesional skin of the MDE patient produced high levels of elastase and cathepsin G compared with fibroblasts from a healthy sex- and age-matched control. Phagocytosis of morphologically normal elastic tissue is a noticeable characteristic feature of MDE. In our case mast-cell activation and the abnormal synthesis and/or release of fibroblast elastolytic enzymes seemed to play a role in the pathogenesis of the MDE.

Hemolytic drugs aniline and dapsone induce iron release in erythrocytes and increase the free iron pool in spleen and liver.

Incubation of rat erythrocytes with the hydroxylated metabolites of aniline and dapsone (4-4'-diaminodiphenylsulfone), phenylhydroxylamine and dapsone hydroxylamine, respectively, induced marked release of iron and methemoglobin formation. On the contrary, no release of iron nor methemoglobin formation was seen when the erythrocytes were incubated with the parent compounds (aniline and dapsone). The acute intoxication of rats with aniline or dapsone induced a marked increase in the erythrocyte content of free iron and methemoglobin, indicating that the xenobiotics are effective only after biotransformation to toxic metabolites in vivo. Prolonged administration of aniline or dapsone to rats produced continuous release of iron from erythrocytes. Marked iron overload was seen in the spleen and in the liver Kupffer cells, as detected histochemically. The spleen weight in these subchronically treated animals was significantly increased. The free iron pool was markedly increased in the spleen and to a lower extent in the liver. The possible relationships between iron release in erythrocytes, oxidative damage seen in senescent cells, hemolysis, overwhelmed capacity of spleen and liver to keep iron in storage forms and subsequent increase in low molecular weight, catalitically active iron is discussed.

Peripheral nerve involvement in ataxia telangiectasia: histological and ultrastructural studies of peroneal nerve biopsy in two cases.

The authors report a histological and electron-microscopic study of the peripheral nerve in two cases of ataxia-telangiectasia showing fiber loss, storage material in Schwann cells and nuclear changes. Nuclear changes are the most typical finding and are correlated with the primary metabolic disorder of DNA repair.

An immunological correlation between the anchoring filaments of initial lymph vessels and the neighboring elastic fibers: a unified morphofunctional concept.

Little has been published on the histochemical and cytochemical properties of anchoring filaments of initial lymph vessels. Previous research suggests that the microfibrils of the anchoring filaments have ultrastructural, histochemical and cytochemical characteristics similar to those of the microfibrils associated with elastic fibers. With the aim of further investigating the histological identity of anchoring filaments, we performed an immunohistochemical study with human skin lymphatics, using antibody HB8, specific for elastic fiber microfibrils. The findings suggested strong molecular similarities between elastic fibers and the fibrils of anchoring filaments of the initial lymph vessels. A comparison of these fibrils showed both constitutional homogeneity and structural continuity from the abluminal surface of the initial lymph vessel to the perivascular elastic fibers and to the adjacent elastic network of connective tissue. In conjunction with previous findings, we propose a unified hypothesis that the elastic fiber system composed of anchoring filaments, perilymphatic sheath and adjacent connective tissue acts by alternating stretching and relaxation to propel lymph towards lymph collectors and draining lymph nodes.

Peptidergic innervation of mesenteric lymphatics in guinea pigs: an immunocytochemical and pharmacological study.

By immunocytochemistry, substance P immunoreactive (SP-IR) and vasoactive intestinal peptide immunoreactive (VIP-IR) nerve fibers were examined in guinea pig mesenteric lymph collectors. The immunoreactive nerve fibers, located in the adventitia of lymphatics, were few and were irregularly distributed along the vessel wall. These fibers appeared to be more numerous and more evenly distributed along the corresponding artery and vein walls within the same area. SP immunoreactivity in the vascular nerves was depleted in guinea pigs injected with capsaicin but was unaffected by the injection of 6-hydroxydopamine. By contrast, VIP-IR nerve fibers were unaffected by both treatments. It is concluded that SP-IR nerve fibers in the lymphatics are likely to be of sensory origin and that VIP containing nerves in the lymph collectors are distinct from SP-containing and noradrenergic nerves. It is also suggested that lymph collectors possess a complex although limited innervation pattern not only of autonomic nerve fibers containing classic neurotransmitters but also of peptidergic nerve fibers of a different origin with a vasomotor and/or sensory action.

The behaviour of Sarcoptes scabiei var. hominis in human skin: an ultrastructural study.

The biology of Sarcoptes scabiei var. hominis is poorly understood because of the lack of an in vivo or in vitro propagation system. To obtain more information on the mite behaviour in its natural habitat we conducted an ultrastructural study of burrows in a number of patients with common scabies. Scanning electron microscopy furnished attractive images of the tunnel, parasite body and eggs architecture and demonstrated the presence of holes in the tunnel roof probably representing aeration structures. Transmission electron microscopy showed a marked keratinocyte damage around burrowing mites, well evident ahead of the mite capitulum also. Faecal pellets containing keratinocyte micro-organelles (melanosomes and mitochondria) were documented in posterior midgut. For the first time we disclosed the adhesion mechanism of eggs to the burrow floor. We showed that the typical finger-like projections of the outer layer of the egg shell gradually disappear where the eggs are in contact with the tunnel floor. This allows the inner layer of the egg shell to fuse and stick with the damaged keratinocytes lining the tunnel floor. Our observation substantiates that Sarcoptes scabiei produces a proteolytic substance (salivary secretions?) that has a key role in its life cycle allowing burrowing, feeding and eggs-burrow adhesion.

[Bullous congenital ichthyosiform erythroderma in a mother and son]. / Eritrodermia congenita ittiosiforme bollosa in madre e figlio.

The occurrence of two cases of bullous congenital ichthyosiform erythroderma (BCIE) in a mother and son is reported. Clinical diagnosis was confirmed by histological and ultrastructural findings, which demonstrated marked changes in the cyto-skeleton of the keratinocytes of the Malpighian layer and areas of cytolysis and hypoplasia of the tonofilament-hemidesmosome complexes in the cells of the granulosa layer. These results and the possible aetiopathogenic mechanisms are discussed in the light of the most recent data in the literature. Treatment with oral etretinate proved to be helpful, but not long lasting.

Eosinophilia-associated muscle disorders: an immunohistological study with tissue localisation of major basic protein in distinct clinicopathological forms.

AIMS: (a) To evaluate tissue eosinophil density, location of eosinophil cytotoxic products, histopathological muscle changes and inflammatory cell types in different eosinophilia-associated myopathies that are clinicopathologically heterogeneous. (b) To determine the immunohistological range of tissue eosinophil density in non-eosinophilic inflammatory myopathies. METHODS: Muscle biopsy specimens from seven patients with blood and/or tissue eosinophilia and clinicolaboratory myopathic signs (five chronic course myopathies, one subacute onset fasciitis/myositis, one acute myositis), and from 18 non-eosinophilic inflammatory myopathies, underwent routine staining, inflammatory infiltrate immunophenotyping, immunostaining for eosinophil major basic protein (MBP) and transmission electron microscopy examination. Eosinophil and total inflammatory cell counts were statistically analysed. RESULTS: Histological examination showed occasional or no infiltrating eosinophils in all cases. MBP staining showed that tissue eosinophil density and percentages in eosinophilia-associated myopathies were significantly higher than in idiopathic myositides. Extracellular MBP diffusion, the hallmark of eosinophil cytotoxicity, was recurrent on sarcolemma and endothelium. Electron microscopy showed eosinophils close to sarcolemma, abundant mast cells, and capillary endothelial swelling. Immunostaining detected a higher mean eosinophil density in idiopathic myositides than previously assessed histologically. CONCLUSIONS: MBP immunohistology on skeletal muscle, previously performed only for acute eosinophilic polymyositis, suggests that eosinophil-mediated injury of muscle cells may occur in a wider spectrum of less aggressive eosinophilia-associated myopathies than previously thought. As conventional histology is likely to underestimate this leucocyte subset, MBP staining may be a useful tool in the analysis of tissue infiltration of eosinophils as a possible treatment target.

Endothelin-1 and endothelin-converting enzyme-1 in human granulomatous pathology of eyelid: an immunohistochemical and in situ hybridization study in chalazia.

Endothelin-1 (ET-1), a potent vasoconstrictor peptide, is involved in several functions of eye pathophysiology, such as regulation of intraocular tension and retinal reactive vasoconstriction. As ET-1 pro-inflammatory and fibrosing activity is emerging in different fields of pathology, we investigated the expression of ET-1 and endothelin-converting enzyme-1 (ECE-1) in chalazia, granulomatous lesions of the eyelid. ET-1 and ECE-1 were analyzed by immunohistochemistry (IHC) in twenty surgically removed chalazia, with regard to expression in eyelid structures and inflammatory infiltrate. Phenotype of ET-1 expressing inflammatory cells was established by double immunofluorescence. The cellular localization of prepro-ET-1 (pp-ET-1) mRNA and ECE-1 mRNA was studied by nonisotopic in situ hybridization (ISH). Neutrophils (PMNs), macrophages and T-lymphocytes were scattered in stroma, around alveoli and grouped in lipogranulomas. PMNs, macrophages, basal epithelium of meibomian adenomers and central ducts immunostained for ET-1. ECE-1 protein was found in meibomian adenomers, conjunctival epithelium, tarsal mucous glands and in inflammatory cells. Hybridization signals for pp-ET-1 mRNA and ECE-1 mRNA were recognized in healthy and degenerating meibomian ducts, adenomers, inflammatory cells, as well as in vessel walls. ECE-1 mRNA was also present in conjunctival epithelium and Henle's crypts. Our findings suggest that the multifunctional peptide ET-1 may have a role in molecular genesis of tissue damage in chalazia. ET-1 cytokine activity is likely to support the migration of inflammatory cells and the setting of lipogranulomas; ET-1 stimulation might contribute to proliferation of fibroblasts and collagen synthesis. ET-1 upregulation on meibomian adenomers and ducts may further enhance granulomas formation by stimulating lipid release.

Initial lymph vessels of the skin and elastic fibres form an integral morphofunctional structure.

Little has been published on the histochemical and cytochemical properties of anchoring filaments of the initial lymph vessels. Previous research suggests that the microfibrils of the anchoring filaments have ultrastructural, histochemical and cytochemical characteristics similar to those of the microfibrils associated with the elastic fibres. With the aim of further investigating the histological identity of anchoring filaments, we performed an immunohistochemical study in human skin lymphatics, using the antibody HB8, specific for elastic fibre microfibrils. There is now a body of evidence suggesting a new concept in the framework of the lymphatic system. It unifies the initial lymph vessels, the anchoring filaments and the satellite elastic fibres in a single and integral entity.