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Y Shoenfeld

Publications and source records attributed to Y Shoenfeld.

At least 343 records · Page 19Linked to original sources
PubMed1997

Neurological dysfunction and hyperactive behavior associated with antiphospholipid antibodies. A mouse model.

Antiphospholipid antibodies (aPL) have been associated with various neurological manifestations, but the underlying mechanism has not been elucidated. We assessed mice with induced experimental antiphospholipid syndrome (APS) for neurological and behavioral changes. After immunization with monoclonal human anticardiolipin antibody (H-3), female BALB/c mice developed elevated levels of circulating anti-negatively charged phospholipids (aPL), anti-beta2-glycoprotein I (abeta2GPI), and anti-endothelial cell antibodies (AECA), along with clinical manifestations of APS like thrombocytopenia and fetus resorption. APS mice were impaired neurologically and performed several reflexes less accurately compared to the controls, including placing reflex (P < 0.05), postural reflex (P < 0.05), and grip test (P = 0.05). The APS mice also exhibited hyperactive behavior in an open field, which tests spatial behavior (P < 0.03), and displayed impaired motor coordination on a rotating bar. aPL in combination with abeta2GPI and AECA is probably involved in the neurological and behavioral defects shown in mice with experimental APS.

Animals↗
PubMed1997

Autoantibodies to tyrosinase: the bridge between melanoma and vitiligo.

BACKGROUND: Tyrosinase is an enzyme that participates in the process of melanin production in normal melanocytes and melanoma cells. Enzymes are known to be autoantigens in various autoimmune disorders; thus, after the detection of antityrosinase antibodies in patients with vitiligo and melanoma, tyrosinase was defined as an autoantigen in these conditions. In some patients with melanoma the disease is associated with the appearance of "vitiligo-like" white patches on the skin, called melanoma-associated hypopigmentation (MAH). In this article, the authors summarize the recent data related to antityrosinase antibodies and expand on their role in the pathogenesis of vitiligo, melanoma, and MAH. In addition, the beneficial clinical applications of antityrosinase antibodies are presented. METHODS: An enzyme-linked immunoadsorbent assay to detect the antityrosinase antibodies in the serum of patients and healthy volunteers was established using mushroom tyrosinase. Employing this method, antityrosinase antibodies were analyzed in a diverse group of patients with melanoma and vitiligo and in mice immunized with tyrosinase. RESULTS: In patients with melanoma, those with metastatic disease had a higher titer of antityrosinase antibodies compared with healthy subjects, whereas patients with MAH and those with no evidence of disease had similar titers to the control group. The titer of antityrosinase antibodies in patients with metastatic melanoma treated by vaccination with antiidiotypic antibodies mimicking the high molecular weight melanoma-associated antigen (HMW MAA) initially increased after the vaccination and then decreased. High titers of antityrosinase antibodies were detected in patients with diffuse vitiligo compared with patients with localized disease and with the healthy control group. Mice immunized with tyrosinase generated a high titer of antityrosinase antibodies and after the inoculation of melanoma cells developed a lower number of lung metastases compared with an unvaccinated control group. CONCLUSIONS: The appearance of antityrosinase autoantibodies in the serum of patients with metastatic melanoma and diffuse vitiligo is characterized by these two pathologies. The changes in the serum level of these autoantibodies in patients with melanoma after immunization with another antigen (HMW MAA) may have diagnostic and therapeutic implications.

Animals↗
PubMed1997

[Ischemic hepatitis in congestive heart failure after an episode of hypotension].

Ischemic hepatitis can occur as an acute episode in advanced congestive heart failure (CHF). The mechanism is massive necrosis of the central lobules resulting from acute hypoxia when low cardiac output further reduces oxygen supply, aggravating underlying congestion due to poor venous outflow. We describe a 70-year-old woman with congestive heart failure for 7 years who was admitted with jaundice, vomiting, abdominal pain and oliguria after an episode of hypotension. The diagnosis of ischemic hepatitis was established by a documented episode of severe hypotension, followed by elevation of serum transaminases, a rise in serum bilirubin and LDH levels, prolonged prothrombin time and acute renal failure. Other causes of acute hepatitis, such as a virus or drugs were excluded, and improved liver and renal function followed hemodynamic stabilization. We conclude that ischemic hepatitis should be considered whenever acute hepatitis follows a recent episode of systemic hypotension, especially in the context of concomitant CHF.

Aged↗
PubMed1997

Anti-neutrophil cytoplasmic antibody-enriched IgG induces adhesion of human T lymphocytes to extracellular matrix proteins.

Recent studies have shown that anti-neutrophil cytoplasmic antibodies (ANCA) can activate neutrophils to adhere to endothelium, degranulate, and cause endothelial cell injury. These data have lead to the hypothesis that the T cell inflammatory response causing the vasculitis in Wegener's granulomatosis (WG) is secondary to stimulation of neutrophils by ANCA. So far there is no evidence for a direct effect of ANCA on lymphocytes. The present study was designed to examine whether lymphocytes can be directly stimulated by ANCA to adhere to endothelial extracellular matrix (ECM) proteins. Human and mouse ANCA-enriched IgG were tested for their ability to increase adhesion of human T lymphocytes to fibronectin, laminin, and intact ECM. Incubation of human T lymphocytes with human ANCA-enriched IgG increased adhesion of the lymphocytes in a dose-dependent manner to fibronectin, laminin, and intact ECM (the percentage adhesion to intact ECM was 55.7 +/- 3.1 and 45.0 +/- 1.0% for lymphocytes incubated with human IgG containing ANCA or control human IgG, respectively; P = 0.0045). The same induction of adhesion to fibronectin, laminin, and intact ECM was observed when the cells were incubated with the F(ab)2 fragment of ANCA-enriched IgG. Similarly, ANCA-enriched IgG produced in mice increased the adhesion of lymphocytes to fibronectin (the percentage adhesion to fibronectin was 29.7 +/- 4.3 and 16.6 +/- 1.9% for lymphocytes incubated with mouse IgG-ANCA or control mouse IgG, respectively; P = 0.0008). These results may suggest that ANCA can directly stimulate lymphocytes to adhere to endothelial ECM and to induce the vasculitic lesions of WG. It remains to be shown by which mechanisms ANCA stimulate lymphocytes to adhere to ECM.

Animals↗
PubMed1997

Subcutaneous T-cell lymphoma in a patient with rheumatoid arthritis not treated with cytotoxic agents.

This case report describes an 81-year-old patient with prolonged rheumatoid arthritis (RA), which was complicated by the occurrence of a subcutaneous T-cell lymphoma. During the course of his illness the patient had not been treated with disease-modifying agents (i.e. cytotoxic agents), but only symptomatically with anti-inflammatory drugs. This finding demonstrates a previously undescribed association between RA and a rare from of subcutaneous T-cell lymphoma, which may add more information to the controversial issue of emergence of malignancy in RA.

Aged↗
PubMed1997

Antiperinuclear factor--clinical, serological and genetic correlates in Israeli patients with rheumatoid arthritis.

The possible association between the presence of antiperinuclear factor (APF) and clinical and genetic parameters was investigated in 54 Israeli patients with rheumatoid arthritis (RA). Rheumatoid factor (RF) was detected in the sera of 43 patients (80%) and APF was positive in 33 (61%). No significant statistical differences were found in the presence of HLA-DR4 and/or DR1 between APF-positive and -negative patients. Furthermore, neither the Ritchie articular index nor the patient's functional class correlated with the presence of APF. The results of our study suggested that although Israeli patients have a different genetic background, the presence and behaviour of APF is similar to that of other Caucasian populations.

Adult↗