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Biomedical subjects

M San

Publications and source records attributed to M San.

14 recordsLinked to original sources

A catalyst of peroxynitrite decomposition inhibits murine experimental autoimmune encephalomyelitis.

Peroxynitrite (PN), the product of nitric oxide (NO) reacted with superoxide, is generated at sites of inflammation. Nitrotyrosine (NT), a marker of PN formation, is abundant in lesions of acute experimental autoimmune encephalomyelitis (EAE), and in active multiple sclerosis (MS) plaques. To determine whether PN plays a role in EAE pathogenesis, mice induced to develop EAE were treated with a catalyst specific for the decomposition of PN. Because this catalyst has no effect upon NO, using it allowed differentiation of PN-mediated effects from NO-mediated effects. Mice receiving the PN decomposition catalyst displayed less severe clinical disease, and less inflammation and demyelination than control mice. Encephalitogenic T cells could be recovered from catalyst-treated mice, indicating that the PN decomposition catalyst blocked the pathogenic action of PN at the effector stage of EAE, but was not directly toxic to encephalitogenic T cells. PN plays an important role distinct from that of NO in the pathogenesis of EAE, a major model for MS.

Animals↗

Mobile right atrial hydatid cyst with multiorgan involvement.

A 25-year-old woman who had hydatid cysts in her lung was referred to our clinic for the hydatid cyst in her cardiac localization. Multiple hydatid cysts of different cardiac localizations were diagnosed by two-dimensional echocardiography, confirmed by computed tomography and magnetic resonance imaging, supported by enzyme-linked immunosorbent assay (ELISA) for echinococcosis. Surgical resection was performed for the right atrial cyst and pathology confirmed the diagnosis. Oral albendazole treatment was given postoperatively. Cathet. Cardiovasc. Intervent. 49:204-207, 2000.

Adult↗

Association between idiopathic mitral valve prolapse and panic disorder.

AIM: To evaluate the association between idiopathic mitral valve prolapse and panic disorder. METHODS: The study comprised 50 patients with idiopathic mitral valve prolapse, 50 patients with panic disorder, and 50 healthy controls. All subjects underwent echocardiographic evaluation. If idiopathic mitral valve prolapse was present, the level of prolapse was measured. To reach psychiatric diagnosis, the Structured Clinical Interview for DSM-IV Axis I Disorders, clinician version, was administered to all subjects. For psychometric evaluation, all subjects completed the Symptom Check List, Beck Depression Inventory, and State and Trait Anxiety Inventory. RESULTS: The prevalence of panic disorder was 16% in patients with idiopathic mitral valve prolapse, and 2% in healthy controls (p=0.03). The average scores on all psychometric scales were the highest in the panic disorder group, whereas average scores in idiopathic mitral valve prolapse group were significantly higher than in the control group (p<0.001). Idiopathic mitral valve prolapse and panic disorder groups displayed similar features of panic attack symptoms. Panic disorder cases with idiopathic mitral valve prolapse and those without it did not significantly differ in terms of psychometric evaluations and clinical symptoms. CONCLUSION: The possibility of comorbidity of panic disorder and idiopathic mitral valve prolapse should be taken into account in the approach to the patients diagnosed with either of the disorders.

Adolescent↗

CTLA-4-Fc treatment of ongoing EAE improves recovery, but has no effect upon relapse rate. Implications for the mechanisms involved in disease perpetuation.

Several laboratories including ours have shown that T cell co-stimulation mediated through B7-1 or B7-2 is critical to the initiation of EAE. The role of T cell co-stimulation in ongoing EAE is less clear. In the present study, 32 mice with established EAE were randomly assigned to receive treatment with either CTLA-4-Fc or control Ig. Mice were followed daily by clinical scoring for 2 months post-immunization. A significant improvement in the degree of recovery following the acute episode and following relapses of EAE was observed in those mice randomized to CTLA-4-Fc treatment. Full clinical remission occurred twice as often in the CTLA-4-Fc group as in those mice receiving placebo, whereas placebo-treated mice were more likely to develop a stable prolonged neurologic deficit. Serial clinical scoring revealed no effect of CTLA-4-Fc upon relapse rate, with greater than 80% of the mice in each group displaying at least one clinical EAE relapse. In that the activation of memory T cells is relatively independent of T cell co-stimulation, these results indicate that development of chronic disease is associated with the activation of naive T cells and the recruitment of the latter cells into the disease process. Blocking B7 molecules may be beneficial in the treatment of established CNS inflammatory demyelinating diseases such as multiple sclerosis.

Abatacept↗

T cells are the main cell type expressing B7-1 and B7-2 in the central nervous system during acute, relapsing and chronic experimental autoimmune encephalomyelitis.

T cell co-stimulation through the CD28 receptor on T cells is critical to the induction of experimental autoimmune encephalomyelitis (EAE). In this study, expression of the co-stimulatory ligands B7-1 (CD80) and B7-2 (CD86), as well as the receptors CD28 and CTLA-4, were quantitated in central nervous system (CNS) tissues from mice at various stages of EAE. Immunohistochemistry and flow cytometry of CNS-infiltrating cells revealed a high percentage of infiltrating T cells expressing B7-1 and B7-2 during acute, chronic and relapsing EAE. Of the infiltrating cells 10-20% were CTLA-4(+), most of which were CD4(+) T cells. B7-1 and B7-2 expression within the CNS during active EAE might increase the potential for local activation of autoimmune T cells; however, the high level of expression of B7 molecules may also provide a mechanism for the autoregulation of activated CTLA-4(+) T cells.

Abatacept↗

B cells are critical to induction of experimental allergic encephalomyelitis by protein but not by a short encephalitogenic peptide.

While the pathology of multiple sclerosis implicates a role for B cells and antibodies in the disease process, results from animal models have yielded conflicting results. To further characterize the role of B cells in experimental allergic encephalomyelitis (EAE), wild-type and B cell-deficient C57BL/6 mice were immunized with either a recombinant form of myelin oligodendrocyte glycoprotein (MOG) or with the encephalitogenic MOG(35-55) peptide. B cell-deficient mice did not develop EAE when immunized with MOG, although they were susceptible to MOG(35-55)-induced disease. In contrast, wild-type mice were fully susceptible to both MOG and MOG(35-55)-induced EAE. B cell-deficient mice immunized with MOG were primed to the encephalitogenic MOG(35- 55) epitope, as their spleen cells responded with Th1 cytokine production in a fashion similar to WT cells when challenged in vitro with MOG protein or MOG(35-55) peptide. These results demonstrate that the form of inducing antigen (protein vs. peptide) plays a role in the pathogenesis of EAE and may be relevant when applying results from the EAE model to multiple sclerosis.

Amino Acid Sequence↗

Left Ventricular Systolic and Diastolic Functions in Patients With Sickle Cell Anemia

The aim of this study was to evaluate the left ventricular systolic and diastolic functions in patients with sickle cell anemia. Fifty-four patients (34 male, 20 female, mean age 22.6 +/- 7.3 years) and 23 healthy persons (12 male, 11 female, mean age 26.7 +/- 6.8 years) were studied. After clinical examination and routine biochemical evaluation by a hematologist, patients with sickle cell anemia were admitted to the study. M-mode and 2-dimensional and Doppler echocardiographic measurements of patients and controls were performed according to criteria of the American Echocardiography Society. The values of the patient groups were compared with the values of normal healthy subjects (controls). Left ventricular systolic and diastolic diameters of sickle cell patients were greater than those of controls (p < 0.001). All of the sickle cell anemia patients had reduced systolic cardiac function (EF: 0.57 +/- 0.1 vs 0.63 +/- 0.06 and FS: 0.30 +/- 0.06 vs 0.34 +/- 0.04, p < 0.02) and abnormal diastolic left ventricular function parameters compared with the control group (IRT: 114 +/- 20 msec vs 65 +/- 7 msec, p < 0.0001; E/A ratio: 1.2 +/- 0.5 vs 1.6 +/- 0.04, p < 0.01). Left ventricular mass (LVM) was greater in patients than in controls (222 +/- 78 g vs 177 +/- 46 g, p < 0.01). Left ventricular systolic and diastolic functions were abnormal in patients with sickle cell anemia, and the left ventricular mass was greater in the patients compared with controls.

Journal Article↗

Inducible nitric oxide synthase gene expression and enzyme activity correlate with disease activity in murine experimental autoimmune encephalomyelitis.

Messenger RNA encoding inducible NO synthase (iNOS) was measured by competitive reverse transcriptase polymerase chain reaction (cRT-PCR) and ribonuclease protection assays in spinal cords from mice at varying stages of experimental allergic encephalomyelitis (EAE) and from control mice. iNOS mRNA was increased in spinal cords from mice with acute EAE. cRT-PCR assays revealed a 10-20-fold increase in iNOS mRNA in spinal cords during acute EAE compared with the level observed in normal mouse spinal cords. Functional iNOS activity, as assessed by assay of calcium-independent citrulline production, was also significantly increased in spinal cords from mice with acute EAE in comparison to normal controls. The correlation of functional iNOS expression with active disease in EAE in consistent with a pathogenic role for excess NO in this model of cell-mediated central nervous system autoimmunity.

Adoptive Transfer↗

A serious complication of percutaneous mitral valvuloplasty: systemic embolism. How can we decrease it? Case history.

Systemic embolism is a potential and severe complication of percutaneous balloon mitral valvuloplasty (PBMV). The incidence of systemic embolism during PBMV has been reported to be less than 5% and only 0.6% with the Inoue technique. This is less than that reported in closed commissurotomy series and about the same as in open commissurotomy. In the authors' series of 50 cases, the incidence of systemic embolism was 2% (1 case). The patient had mitral restenosis (after closed commissurotomy) with mild to moderate valvular and subvalvular calcification, and cerebral embolism occurred during the procedure. To prevent systemic embolism, the authors' standard policy was to perform transesophageal echocardiography (TEE), computed tomography, and magnetic resonance imaging before the procedure and to give heparin during the procedure and two months preceding it in cases with atrial fibrillation or with a history of previous embolism and to limit manipulation of the catheter in the left atrium. The authors believe that a close scrutiny in the selection of patients, improved technology of the dilating system, good experience with PBMV, and adequate heparinization are also of great importance in the prevention of thromboembolic complications.

Anticoagulants↗

Hydatid disease presenting as cardiac tamponade. A case history.

Although hydatid disease has been reported in almost all human tissues, cardiac involvement is uncommon. The authors report a case of cardiac hydatid disease presenting with cardiac tamponade. The diagnostic value of transthoracic and transesophageal echocardiography, computed tomography, and angiography in hydatid heart disease is also discussed.

Adult↗

Ultrastructural alterations in the myocardium of patients with sickle cell anemia.

Endomyocardial biopsies of patients with sickle cell anemia (SCA) were examined ultrastructurally. Myocardial fibers of patients revealed prominent degenerative changes such as nuclear chromatin condensation, myofibrillar degeneration, sarcosomal changes, dilatation of sarcoplasmic reticulum, formation of autophagic vacuoles, increase of lipofuscin granules and occurrence of vacuoles derived from endoplasmic reticulum and/or transverse tubules in some micrographs. Furthermore, edematous changes were developed at the same area where the degenerative changes were prominent. All of these cellular alterations could be related with ischemia resulting from local microvascular occlusion.

Adult↗