Biomedical subjects

A Barat

Publications and source records attributed to A Barat.

At least 37 records · Page 2Linked to original sources

PubMed1996

Interferon-inducible protein-10 is highly expressed in rats with experimental nephrosis.

Interferon-inducible protein (IP)-10 is a small glycoprotein member of a family of chemotactic cytokines structurally related to interleukin-8. We have recently described the induction of IP-10 mRNA in mouse mesangial cells stimulated with lipopolysacharide, interferon-gamma, and tumor necrosis factor-alpha. To further evaluate a possible role for this chemokine in renal injury, we have studied IP-10 in an experimental model of nephrosis induced in rats by adriamycin. High levels of glomerular IP-10 mRNA expression and glomerular and tubulointerstitial IP-10 protein were seen on day 21, coinciding with maximal proteinuria, glomerular tumor necrosis factor mRNA expression, and interstitial cellular infiltrates. Maintenance on a low protein diet not only delayed the appearance of proteinuria and interstitial cellular infiltrate but also decreased glomerular IP-10 mRNA expression. Isolated normal glomeruli and cultured glomerular epithelial and mesangial cells from normal rats expressed IP-10 mRNA upon stimulation with 100 U/ml interferon or 1 microgram/ml lipopolysaccharide for 3 hours. IP-10 mRNA expression was also inducible by lipopolysaccharide and cytokines in NRK 49F renal interstitial fibroblasts and, to a lesser extent, in NRK 52E tubular epithelial cells. Furthermore, IP-10 protein was inducible in murine mesangial cells. We conclude that IP-10 is highly inducible in vitro and in vivo in resident glomerular and tubulointerstitial cells. IP-10 may participate in the modulation of renal damage in experimental nephrosis.

Animals↗

PubMed1995

Cutaneous tuberculosis: a clinical, histopathologic, and bacteriologic study.

BACKGROUND: In recent years cutaneous infections with Mycobacterium tuberculosis with an atypical clinical appearance have become more common because of the increasing number of immunocompromised patients. OBJECTIVE: We report the clinical, histopathologic, and bacteriologic data of 11 patients with several forms of cutaneous tuberculosis seen during the past 14 years. METHODS: Patients from whom M. tuberculosis was isolated from culture of skin biopsy specimens, sinus drainage, or material aspirated from cutaneous abscesses were included. In all but two patients a biopsy specimen was obtained for histopathologic study. All but one patient received combined antituberculous therapy. RESULTS: The clinical diagnoses were scrofuloderma (four cases), cutaneous miliary tuberculosis (two), lupus vulgaris (two), tuberculous gumma (two), and one unclassified. All but three patients had evidence of either previous or simultaneous tuberculous foci other than in the skin. Histopathologic findings varied according to the type of cutaneous tuberculosis. CONCLUSION: In some patients with cutaneous tuberculosis, lesions are atypical in appearance because of immunodeficiency. Culture for M. tuberculosis should be performed in all suspected cases, even in those in whom special stains for acid-fast bacilli are negative.

Abscess↗

PubMed1995

Malignant hidroacanthoma simplex. A case report and literature review.

A 73-year-old woman with a malignant hidroacanthoma simplex on her right lower limb is reported. The lesion was immunohistochemically studied. Carcino-embryonic antigen and epithelial membrane antigen were found in the luminal border of ductal structures within the aggregations of neoplastic cells. We review the literature on this subject.

Acrospiroma↗

PubMed1994

Prevention of mercuric chloride-induced nephritis in the brown Norway rat by treatment with antibodies against the alpha 4 integrin.

HgCl2 induces the synthesis of anti-GBM Abs with the development of glomerular and interstitial nephritis, as well as proteinuria, in the Brown Norway rat. The development of this autoimmune disease is a consequence of the appearance of an autoreactive T cell subset-inducing activation of B cells. The administration to mercury-treated rats of the mouse anti-human VLA alpha 4 HP2/1 mAb, which cross-reacts with the rat homologue integrin, completely abrogated the interstitial cell infiltrates. As demonstrated by peripheral blood analysis, this effect is not a result of the depletion of circulating leukocytes or leukocyte subsets. Interestingly, the administration of Abs specific for the alpha 4 integrin also highly reduced anti-GBM Ab synthesis, thus preventing detectable glomerular deposits and proteinuria. Our results confirm that in vivo alpha 4 functions in adhesive interaction of circulating leukocytes and vascular endothelium, and is centrally important in the extravasation and migration of T lymphocytes to sites of tissue injury. We also found a complete absence of interstitial cell infiltrates, together with a positive glomerular IgG lineal deposition pattern, when anti-GBM Abs were passively transferred to rats pretreated with anti-alpha 4 mAb, thus indicating an independent role of alpha 4 integrin in both extravasation of immune cells and production of autoantibodies. Furthermore, these in vivo findings provide preliminary evidence for the participation of the VLA-4 integrin in mediating the intercellular interaction of leukocytes regulating the production of Abs, most likely through the existence of additional yet unknown ligand(s).

Animals↗

PubMed1993

Giant trichoblastoma on the scalp.

We describe a case of giant trichoblastoma that had been present for many years on the scalp of a 69-year-old man. The specimen was examined histopathologically, immunohistochemically, and ultrastructurally. Histopathologic examination showed that neoplastic cells were arranged in different patterns from area to area, including rippled, adenoid, and palisading patterns. In some areas of the neoplasm, foci of sebaceous differentiation were also present. The ultrastructural characteristics of neoplastic cells support the notion that trichoblastomas are neoplasms composed mostly of follicular germinative cells.

Aged↗

PubMed1993

Blockade of endothelium-dependent responses in conscious rats by cyclosporin A: effect of L-arginine.

This study was undertaken to examine the effect of the major immunosuppressive drug, cyclosporin A (CyA), on endothelial function. Conscious Wistar rats, treated with CyA (25 mg.kg-1 x day-1 im for 15 days), developed an inhibition of the endothelium-dependent acetylcholine (ACh)-mediated vasodilation, diuresis, natriuresis, and guanosine 3',5'-cyclic monophosphate excretion. The response to two endothelium-independent agents, i.e., sodium nitroprusside and atrial natriuretic peptide was preserved in similarly treated rats. The toxic effects of CyA were acutely overcome by the administration of the amino acid L-arginine (L-Arg), a source of substrate for nitric oxide. Moreover, the simultaneous administration of L-Arg (200 mg/kg ip for 15 days) significantly prevented the functional effects of CyA toxicity. The present data suggest that, in early stages of CyA toxicity, the predominant functional alteration occurs at the endothelial level. The reversibility of such alteration by L-Arg opens the possibility for further strategies aimed to reduce the harmful effects of CyA.

Acetylcholine↗

PubMed1993

[Calciphylaxis in chronic renal failure].

Three cases of calciphylaxis in patients with terminal renal insufficiency are discussed. The existence of metastatic calcifications, mainly vascular, in patients with chronic renal insufficiency is frequent. However calciphylaxis is a process which is rarely found in these patients. This entity is characterized by the obliteration of small vessels with ischemia and necrosis. The exceptionality of the disease, its difficult treatment and poor evolution make calciphylaxis a bad prognostic complication which should be considered in the differential diagnosis of cutaneous lesions in patients with chronic renal insufficiency.

Aged↗

PubMed1992

Acquired symmetric lipomatosis of the soles. A plantar form of the Madelung-Launois-Bensaude syndrome.

Benign symmetric acquired lipomatosis is a rare condition characterized by multiple, diffuse, subcutaneous collections of nonencapsulated mature adipose tissue. A thick and disfiguring deposit of fat is symmetrically distributed in the subcutaneous tissue of the neck, upper trunk and proximal portions of the upper extremities. The face, distal extremities, hands, and feet are characteristically spared. We describe a case in which only plantar involvement was present.

Adipose Tissue↗

PubMed1992

[The immunological characterization of 63 cases of Hodgkin's disease with a panel of 8 antibodies].

Sixty three cases of Hodgkin's disease are studied (two with lymphonodular predominance, 15 with diffuse lymphocyte predominance, 26 nodular sclerosis, 15 mixed cell and 5 lymphocyte depletion) with a panel of 8 monoclonal antibodies, material routinely used and included in paraffin: Ber H2 (CD30), Leu M1 (CD15), Common Leukocyte Antigen (CD45), L26 (CD20), MB2, UCHL1 (CD45 RO), MTI (CD43) and Epithelial Membrane Antigen. Ber H2 turned out to be the most usefull marker, positive in 100% of cases, independently of the histologic type. Positiveness with Leu M1 ranged from 100% (2/2 cases) of lymphonodular predominance, to 53.3% (8/15 cases) of diffuse lymphocyte predominance. The reactivity of the rest was variable, 1 though it is note worthy the positiveness of B markers (L26, MB2) in the two cases with lymphonodular predominance. In the other subtypes, reactivity with L26 was greater than that with MB2. T cell marker expression was minimal, except for the positiveness in 40% of cases (2/5) of the lymphocyte depletion type. In addition, the results of other series are revised and as a result the possible histogenesis of Hodgkin's disease is discussed.

Antibodies, Monoclonal↗

PubMed1991

Chondroitinases release acetylcholinesterase from chick skeletal muscle.

Bacterial chondroitinases (both ABC and AC types) release asymmetric and globular forms of AChE from chick skeletal muscle samples. Heparinases, however, including heparitinase I, fail to do so under different incubation conditions. These results do not support the direct implication of the heparin/heparan sulfate family of GAGs in the interaction of the different AChE molecular forms with the muscle ECM. GAGs of the chondroitin/dermatan sulfate group could however be involved, either directly or indirectly, in the attachment of the AChE collagen-like tail to the muscle basal lamina.

Acetylcholinesterase↗

PubMed1991

Solubilization of asymmetric acetylcholinesterase by polyanions.

A number of polyanions, including polysulfates (sulfated glycosaminoglycans (GAGs), dextran and pentosan sulfates, and polyvinylsulfate), polyphosphates (tetrapolyphosphate, polyadenylate) and polycarboxylates (polyaspartate, polyglutamate) solubilize asymmetric acetylcholinesterase (AChE) from chick muscle at low ionic strength, and partially or totally displace AChE tailed forms bound to heparin-agarose columns. The previously reported solubilization of asymmetric AChE by heparin, or the proven affinity of the tailed enzyme forms for this GAG, cannot therefore be taken as direct proof of the involvement of heparin-like heparan sulfate proteoglycans in the anchorage of the collagenous tail of the enzyme to the basal lamina in skeletal muscle.

Acetylcholinesterase↗

PubMed1991

Malignant combined nevus.

This report describes an example of combined nevus with malignant transformation. The clinical impression was blue nevus. Histologically, the lesion was composed of a cellular blue nevus in the reticular dermis and an overlying compound melanocytic nevus. The junctional component of the melanocytic nevus showed transition to malignant melanoma in situ. A review of the literature failed to find a precedent for the present case.

Cell Nucleus↗

PubMed1991

Erythema elevatum diutinum mimicking porphyria cutanea tarda.

A case of erythema elevatum diutinum (EED) closely resembling porphyria cutanea tarda (PCT) is reported. The initial skin biopsies were suggestive for PCT but porphyrin levels in the urine, stool and plasma were normal. A further biopsy from an early cutaneous lesion showed a leucocytoclastic vasculitis with fibrinoid necrosis of the vessel walls.

Adult↗

PubMed1991

Localized epidermal necrolysis (erythema multiforme-like reaction) following intravenous injection of vinblastine.

We report a case of localized epidermal necrolysis that developed 24 hours after an intravenous injection of vinblastine. Clinically, the lesions consisted of erythematous macules, vesicles, and bullae with a linear arrangement over the injected vein. Histologically, the lesions showed features closely resembling erythema multiforme (epidermal necrolysis). We discuss the pathogenesis of this curious cutaneous drug reaction and review the literature concerning local cutaneous complications associated with intravenously administered chemotherapeutic agents.

Erythema Multiforme↗

PubMed1991

Postlymphography linear dermatitis.

Cutaneous effects secondary to lymphography are rare events. We herein report a patient with Hodgkin's disease who developed a linear dermatitis in both lower limbs 6 days after a pedal lymphography. Histopathologic examination of the lesions demonstrated a subacute dermatitis. Patch tests with the substances used in the lymphography yielded negative results. We discuss the possible pathogenic mechanisms of this striking linear dermatitis.

Adult↗

PubMed1991

Erythema elevatum diutinum in a patient with acquired immunodeficiency syndrome. Another clinical simulator of Kaposi's sarcoma.

Several types of vasculitis have been described in patients with human immunodeficiency virus infection. Erythema elevatum diutinum is a rare variant of cutaneous leukocytoclastic vasculitis which, with the exception of the case reported herein, has been described only once in human immunodeficiency virus-infected patients. Our male patient, a longtime intravenous drug abuser, had cutaneous lesions, closely resembling Kaposi's sarcoma, on the extensor surfaces of the lower extremities. Cutaneous biopsy specimens, however, demonstrated leukocytoclastic vasculitis with fibrinoid necrosis of the vessel walls and areas of basophilic degeneration of collagen bundles in early lesions, whereas late lesions showed dense diffuse fibrosis with proliferation of dermal spindle cells and some foci of residual leukocytoclastic vasculitis. Oral therapy with dapsone resulted in marked clearing of the cutaneous lesions within few days. This case raises the necessity of histologic confirmation for all cases of suspected Kaposi's sarcoma in patients with acquired immunodeficiency syndrome. We discuss the possible pathogenesis of leukocytoclastic vasculitis in human immunodeficiency virus-infected patients.

Acquired Immunodeficiency Syndrome↗

PubMed1991

Localized hyperkeratosis lenticularis perstans (Flegel's disease).

A case of hyperkeratosis lenticularis perstans involving only the back of a thirty-nine-year-old woman is reported. Histologic examination showed foci of compact and eosinophilic hyperkeratosis overlying a thinned stratum malpighii. In the underlying papillary dermis there was no evidence of inflammatory infiltrate. This case demonstrates that hyperkeratosis lenticularis perstans may appear as a localized disorder, and that the inflammation is not an essential pathogenic process in this disorder.

Adult↗

PubMed1990

Asymmetric acetylcholinesterase is absent from chick retina, but present in choroid, ciliary muscles and iris.

Freshly dissected chick neural retina and pigmented epithelium do not apparently contain asymmetric molecular forms (A-forms) of acetylcholinesterase (AChE). The neighboring choroid, and the ciliary muscles and iris, are however rich in type II A-forms (high salt/EDTA-extractable). Most if not all the asymmetric AChE activity detected in chick 'whole retina' preparations could then be explained in terms of contamination by non-retinal eye tissues.

Acetylcholinesterase↗