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Biomedical subjects

Yair Levy

Publications and source records attributed to Yair Levy.

At least 19 recordsLinked to original sources
PubMed2006

Novel bioresorbabale composite fiber structures loaded with proteins for tissue regeneration applications: microstructure and protein release.

Novel bioresorbable core/shell composite fiber structures loaded with proteins were developed and studied. These unique polymeric structures are designed to combine good mechanical properties with a desired controlled protein-release profile, to serve as scaffolds for tissue regeneration applications. Core/shell fiber structures were formed by "coating" poly(L-lactic acid) fibers with protein-containing poly(DL-lactic-co-glycolic acid) porous structures. Shell preparation (coating) was performed by the freeze-drying of water in oil emulsions. The present study focused on the effect of the emulsion's formulation on the porous shell structure and on the resulting cumulative protein release from the composite fibers for 90 days. Horseradish peroxidase (HRP) was used as the protein source. The release profiles usually exhibited an initial burst effect, accompanied by a decrease in release rate with time, as is typical for diffusion-controlled systems. The HRP content and the emulsion's organic:aqueous phase ratio exhibited significant effects on both the shell microstructure and the HRP release profile from the composite fibers, whereas the polymer content of the emulsion's organic phase only affected these fiber characteristics in certain cases. Proper selection of the emulsion's parameters can yield core/shell fiber structures with the desired protein release behavior and other useful physical properties.

Biocompatible Materials↗
PubMed2006

Anti-beta2-glycoprotein I in Sjogren's syndrome is associated with parkinsonism.

The nervous system may be involved in up to 30% of patients with Sjogren's syndrome (SS). We describe three patients with Sjogren's syndrome and a concomitant parkinsonian syndrome. Elevated titers of anti-beta2-glycoprotein I IgG were found in the serum of all three patients. This autoantibody is strongly associated with anticardiolipin (aCL) antibodies, antiphospholipid syndrome (APS), and thromboembolic phenomena, but its role in the pathogenesis of the parkinsonian disorder in SS is unclear. These patients may present a subtype of SS patients in which the presence of aCL antibodies is associated with central nervous system involvement predominantly in the basal ganglia.

Aged↗
PubMed2006

Participation of family members in ward rounds: Attitude of medical staff, patients and relatives.

OBJECTIVE: To assess the attitude of medical staff, patients and their relatives to the presence of FMs in WRs. METHODS: This prospective study was performed in an Internal Medicine Department in Israel. WRs were conducted without (phase 1) and with (phase 2) the presence of FMs. Questionnaires were completed by staff members (N = 26, 23), patients (N = 26, 35) and FMs (N = 32, 40) during phases 1 and 2, respectively. RESULTS: 82.6%, 96% and 96.7% of staff, patients and relatives, respectively, expressed a positive attitude towards the participation of FMs in WRs. Staff members became significantly more positive about the concept after having undergone the experience. Patients believed it contributed to a better understanding of their disease and FMs felt it provided them with an opportunity to participate in medical decision-making. CONCLUSION: Hospitalized patients would like their FMs to participate in WRs. Staff members were reluctant at first, but developed a more positive attitude towards the idea after the experience. PRACTICE IMPLICATIONS: Incorporating FMs into WRs is plausible, though adjustment of WRs' routine to the change will be needed. This move might increase patients' satisfaction from WRs.

Attitude of Health Personnel↗
PubMed2006

Rehabilitation time after simultaneous bilateral photorefractive keratectomy for low to moderate myopia.

PURPOSE: To evaluate the visual acuity rehabilitation time after simultaneous bilateral photorefractive keratectomy (PRK) using a flying small spot laser. SETTING: Eye Tech Medical Laser, Tel Aviv, Israel. METHODS: In this prospective interventional nonrandomized clinical trial, 42 consecutive eyes (21 patients) with myopia ranging from -0.75 to -5.50 diopters (D) (mean -2.75 D +/- 1.18 [SD]) and astigmatism up to -2.75 D (mean -0.64 +/- 0.55 D) were treated with bilateral simultaneous PRK using the ESIRIS excimer laser (Schwind). Main outcome measures were uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), and manifest refraction up to 12 weeks after surgery. Both eyes of each patient were examined at the same follow-up after initial treatment. RESULTS: Within 2 weeks and 1 month of the laser procedure, the UCVA was at least 20/40 in 1 eye in 85.7% of patients (18 patients) and 100% of patients (21 patients), respectively. After 2 weeks, UCVA was at least 20/20, 20/25, and 20/40 in 7.1%, 40.5%, and 80.9% of eyes. The final mean manifest spherical equivalent 12 weeks post laser treatment was -0.10 +/- 0.26 D, with a mean sphere of +0.02 +/- 0.22 D and a mean cylinder of -0.24 +/- 0.37 D. No eye had a BCVA loss during the follow-up. CONCLUSION: Simultaneous bilateral PRK using a flying small spot excimer laser for low to moderate myopia allowed most patients to return to most daily tasks in a couple of weeks without compromising safety.

Adult↗
PubMed2006

Immunomodulation of experimental pulmonary fibrosis by intravenous immunoglobulin (IVIG).

OBJECTIVES: To assess the immunomodulatory effect of intravenous immunoglobulin (IVIG) using an experimental model of bleomycin-induced pulmonary fibrosis. METHODS: Pulmonary fibrosis was induced in C57BL/6 mice by direct intratracheal injection of bleomycin. Mice were treated with IVIG 1 week prior to (prevention protocol), or 10 days following bleomycin injection, when the disease was in progress. The controls used in the study included mice given phosphate buffered saline (PBS) and mice subjected to a commercial individual-IgG. Collagen-I deposits in the affected lungs were detected by Sirius red staining of paraffin embedded lung sections. The collagen-I content was measured by employing the hydroxyproline assay. RESULTS: Prevention of bleomycin-induced pulmonary fibrosis by IVIG has been demonstrated by reduced expression of collagen-I protein in the affected lungs. The hydroxyproline levels in the lungs of the IVIG-treated mice were 214.33 +/- 13.56 microg/1 g tissue, compared to the higher levels in lungs of IgG treated mice (342.44 +/- 35.60 microg/1 g tissue) or untreated controls 328.00 +/- 45.55 microg/1 g tissue, (p < 0.0001). Effective treatment of bleomycin-induced pulmonary fibrosis by IVIG has been demonstrated by the reduced expression of collagen-I protein in the affected lungs, detected by sirius red histological staining. The hydroxyproline levels in the lungs of the IVIG-treated mice were 261.00 +/- 18.81 microg/1 g tissue, in comparison to the higher levels in the lungs of the IgG treated mice (342.43 +/- 32.89 microg/1 g tissue) and of untreated controls (344.33 +/- 49.85 microg/1 g tissue), (p < 0.001). CONCLUSIONS: Based on these preliminary studies, we conclude that IVIG may have a beneficial effect in the down regulation of collagen-I levels in the lungs of mice with bleomycin-induced pulmonary fibrosis.

Animals↗
PubMed2005

Increased platelet deposition on extracellular matrix under flow conditions in patients with antiphospholipid syndrome who experience thrombotic events.

OBJECTIVE: To assess platelet function under defined flow conditions in patients with antiphospholipid syndrome (APS) and to correlate the results with thrombotic complications and the presence of subsets of antiphospholipid antibodies (aPL), lupus anticoagulant (LAC), and/or anticardiolipin antibodies (aCL). METHODS: We studied 88 randomized APS patients with or without a history of thrombosis. Seventeen patients with other thrombosis (no APS) and 26 healthy subjects served as controls. Platelet adhesion and aggregation on the extracellular matrix were measured with a cone-and-plate(let) analyzer (CPA) by examining the percentage of total area covered with platelets (surface coverage [SC]) and the mean size of surface-bound objects (average size [AS]) and were compared with platelet responses to different ADP concentrations by conventional aggregometry. RESULTS: Under defined flow conditions, SC and AS were significantly higher for venous thrombosis and arterial thrombosis in APS patients compared with no thrombosis, other thrombosis, and healthy control groups. The increased platelet adhesion and aggregation in APS patients with thrombotic events was associated with higher levels of von Willebrand factor (vWF) antigen (mean +/- SD 230.6 +/- 51.2%) and ristocetin cofactor activity (181.0 +/- 36.0%). No change in CPA and vWF parameters was found in APS patients with positive results for aPL who did not undergo thrombotic events or in patients with other thrombosis. The CPA parameters were neither associated with the high response of platelets to ADP nor associated with the presence of LAC, aCL, or both. The CPA parameters were similarly increased irrespective of aspirin use. The results suggest that the increased adhesion properties of platelets in APS patients could be mediated by high levels and activity of vWF. This complements the known ability of APS antibodies to enhance platelet response to agonists in conventional aggregometry. CONCLUSION: The CPA test was found to be valuable in differentiating APS patients with and without thrombotic complications.

Adult↗
PubMed2005

Ocular higher-order aberrations in eyes with supernormal vision.

PURPOSE: To quantify ocular higher-order aberrations (HOAs) in eyes with supernormal vision, that is, natural uncorrected visual acuity (UCVA) > or = 20/15, to analyze the correlation between ocular HOAs and age in these eyes, and to investigate the correlation of HOAs between right and left eyes. DESIGN: Observational case series. METHODS: Ocular HOAs were examined across a naturally dilated pupil with a diameter > or = 6.0 mm in 70 eyes of 35 subjects with > or = 20/15 UCVA (mean age 24.3 years +/- 7.7 [SD]) using the Nidek OPD scan wavefront aberrometer. Root-mean-square (RMS) values of HOA, total spherical aberration (TSA), total coma (TC), and total trefoil (TT) were analyzed. Correlation analysis was performed to assess the association between ocular HOAs and age and the correlation of HOAs between right and left eyes. RESULTS: Mean RMS values were 0.334 +/- 0.192 microm for HOA, 0.110 +/- 0.077 microm for TSA, 0.136 +/- 0.081 microm for TC, and 0.268 +/- 0.220 microm for TT. There were no significant differences in the mean values of HOA, TSA, TC, and TT between right and left eyes. The Pearson correlation coefficient between right and left eyes for TSA was 0.764 (P<.0001). No significant correlation was found between right and left eyes for HOA, TC, and TT. No significant correlation was found between each of the ocular aberrations and age. CONCLUSIONS: The amount of ocular HOAs in eyes with natural supernormal vision is not negligible, and is comparable to the reported amount of HOAs in myopic eyes.

Adolescent↗
PubMed2005

Ocular higher-order aberrations in myopia and skiascopic wavefront repeatability.

PURPOSE: To study the distribution of ocular higher-order aberrations (HOAs) in a myopic population and to assess the repeatability of HOA measurements determined by a commercially available skiascopic wavefront sensor. SETTING: Department of Ophthalmology, Assaf Harofeh Medical Center, Zerifin, Israel. METHODS: Ocular HOAs were examined 3 times across a 6.0 mm naturally dilated pupil in 61 eyes using the Optical Path Difference (OPD)-scan wavefront aberrometer. Root-mean-square (RMS) values of HOAs, total spherical aberration (TSA), total coma (TC), and total trefoil (TT) were analyzed. Correlation analysis was performed to assess the aberration symmetry between right and left eyes. The repeatability of the OPD-scan measurements was assessed by calculating Pearson r correlation coefficients between each pair of measurements and the interclass correlation coefficients between the 3 measurements of each score. RESULTS: The mean RMS values of HOAs, TSA, TC, and TT were 0.347 microm +/- 0.252 (SD), 0.120 +/- 0.174 microm, 0.165 +/- 0.168 microm, and 0.252 +/- 0.157 microm, respectively. The HOAs, TSA, TC, and TT changed slightly and not significantly with increasing refractive error (all P>.05). The RMS level of HOAs and TTR of the 3rd measurement was significantly different from the 1st and 2nd measurements (P<.05), with overall low correlation between the 3 measurements for the HOAs, TSA, TC, and TT. CONCLUSIONS: The ocular wavefront aberrations varied greatly from subject to subject. Ocular HOAs were not correlated with refractive error. The repeatability of HOAs measurements with the OPD-aberrometry was low.

Adolescent↗
PubMed2005

Functional T-lymphocyte dichotomy in the peripheral blood of patients with unstable angina.

OBJECTIVES: Herein, we investigated the percentage of T-helper (Th1) and Th2 cells among the general T-cell population in the peripheral blood of patients with stable angina (SA) and unstable angina (UA). BACKGROUND: Recent evidence suggests that Th1 cells and the cytokines that they secrete (especially IFN-gamma) have a role in the activation of macrophages, promotion of clot formation and destabilization of atherosclerotic plaques. Thus, Th1 cytokines may contribute to the initiation and progression of UA. In contrast, cytokines secreted by Th2 cells (e.g. IL-10) are known to inhibit activation and proliferation of Th1 cells and the secretion of IFN-gamma, lysosomal enzymes and metalloproteinases. Therefore, we sought to examine whether the ratio of IFN-gamma to IL-10 secreting cells is altered in patients with UA. METHODS: The percentage of Th1 and Th2 cells among the general T-cell population was determined by fluorescent intracellular cytokine staining (IFN-gamma and IL-10, out of the total CD3 positive cells). RESULTS: The percentage of T-cells positive for intracellular IFN-gamma was significantly higher in patients with UA (n = 22) in comparison with SA (n = 20) patients (39.0+/-2.8% and 29.6+/-2.7%, respectively. P = 0.02). There was no significant difference in intracellular IL-10 positive cells between the two groups. In addition, there was no significant difference in the ratio between the intracellular IFN-gamma positive cells and the intracellular IL-10 positive cells. CONCLUSIONS: There is an increased activity of Th1 cells in patients with UA in comparison with patients with SA. There is no evidence of heightened activity of Th2 cells in either group. Thus, IFN-gamma secreted by peripheral blood T-lymphocytes,may be an important immunomodulator contributing to destabilization of the atheromatous plaque lying at the base of the etiopathogenesis of unstable angina.

Aged↗
PubMed2005

Response of vasculitic peripheral neuropathy to intravenous immunoglobulin.

Peripheral neuropathy is a prominent feature of the systemic and secondary vasculitides. Usually, it responds to corticosteroids therapy, but in certain cases it may resist corticosteroid or immunosuppressive treatment, or both. The objective of this study is to present case reports of patients who exhibited various inflammatory diseases, accompanied with vasculitic peripheral neuropathies, for which intravenous immunoglobulin (IVIg) was used for treatment. The study included 10 patients with the following: Sjögren's syndrome (1), systemic lupus erythematosus (2), vaccination-induced vasculitis (1), Churg-Strauss vasculitis (1), mixed cryoglobulinemia (2), polyarteritis nodosa (1), sarcoidosis (1), and scleroderma (1). All developed vasculitic peripheral neuropathy and were treated with 1-13 cycles of high-dose IVIg (2 g/kg body weight). The patients were followed up for 1-5 years after this treatment. Results showed that in all but two patients (mixed cryoglobulinemia associated with hepatitis C and sarcoidosis), neuropathy improved or completely resolved after IVIg treatment. In conclusion, IVIg may be beneficial in cases of resistant vasculitic peripheral neuropathy. IVIg should probably be considered as a sole or adjuvant treatment in patients for whom conventional treatment is contraindicated, or for patients in whom conventional treatment has failed.

Child↗
PubMed2005

Intravenous immunoglobulin therapy and systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease with diverse manifestations. We suggest that intravenous immunoglobulin (IVIg) therapy may be beneficial and safe for various manifestations in SLE. A structured literature search of articles published on the efficacy of IVIg in the treatment of SLE between 1983 and 2005 was conducted. We searched the terms "IVIg," "intravenous immunoglobulin," "lupus," "SLE," and "systemic lupus erythematosus." The various clinical manifestations of SLE that were reported to be successfully treated by IVIg in case reports include autoimmune hemolytic anemia, acquired factor VIII inhibitors, acquired von Willebrand disease, pure red cell aplasia, thrombocytopenia, pancytopenia, myelofibrosis, pneumonitis, pleural effusion, pericarditis, myocarditis, cardiogenic shock, nephritis, end-stage renal disease, encephalitis, neuropsychiatric lupus, psychosis, peripheral neuropathy, polyradiculoneuropathy, and vasculitis. The most extensive experience is with lupus nephritis. There are only a few case series of IVIg use in patients with SLE with various manifestations, in which the response rate to IVIg therapy ranged from 33 to 100%. We suggest that IVIg devoid of sucrose, at a dose of 2 g/kg over a 5-d period given uniformly and at a slow infusion rate in patients without an increased risk for thromboembolic events or renal failure, is a safe and beneficial adjunct therapy for cases of SLE that are resistant to or refuse conventional treatment. The duration of therapy is yet to be established. Controlled trials are warranted.

Adult↗
PubMed2005

Intravenous immunoglobulin in therapy of peripheral neuropathy.

Peripheral neuropathy (PN) can be a manifestation of various neurological, infectious, metabolic, autoimmune, rheumatic, and malignant diseases. During the past decade, intravenous immunoglobulin (IVIg) has been increasingly used in the therapy of PN. Compared with other immunomodulatory therapies, IVIg has an excellent safety profile. IVIg is used today as a first-line therapy in the treatment of Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, and multifocal motor neuropathy. Some small studies and reports of clinical cases presented in this article found benefit from IVIg in treating PN associated with diabetes, paraproteinemia, HIV, multisystem rheumatic diseases, and paraneoplastic PN. No clear recommendations can be made relating the use of IVIg in these conditions. Prospective, randomized trials are required to clarify this issue.

Autoimmune Diseases↗
PubMed2004

Early response to immunosuppressive therapy predicts good renal outcome in lupus nephritis: lessons from long-term followup of patients in the Euro-Lupus Nephritis Trial.

OBJECTIVE: In the Euro-Lupus Nephritis Trial (ELNT), 90 patients with lupus nephritis were randomly assigned to a high-dose intravenous cyclophosphamide (IV CYC) regimen (6 monthly pulses and 2 quarterly pulses with escalating doses) or a low-dose IV CYC regimen (6 pulses of 500 mg given at intervals of 2 weeks), each of which was followed by azathioprine (AZA). After a median followup of 41 months, a difference in efficacy between the 2 regimens was not observed. The present analysis was undertaken to extend the followup and to identify prognostic factors. METHODS: Renal function was prospectively assessed quarterly in all 90 patients except 5 who were lost to followup. Survival curves were derived using the Kaplan-Meier method. RESULTS: After a median followup of 73 months, there was no significant difference in the cumulative probability of end-stage renal disease or doubling of the serum creatinine level in patients who received the low-dose IV CYC regimen versus those who received the high-dose regimen. At long-term followup, 18 patients (8 receiving low-dose and 10 receiving high-dose treatment) had developed permanent renal impairment and were classified as having poor long-term renal outcome. We demonstrated by multivariate analysis that early response to therapy at 6 months (defined as a decrease in serum creatinine level and proteinuria <1 g/24 hours) was the best predictor of good long-term renal outcome. CONCLUSION: Long-term followup of patients from the ELNT confirms that, in lupus nephritis, a remission-inducing regimen of low-dose IV CYC followed by AZA achieves clinical results comparable with those obtained with a high-dose regimen. Early response to therapy is predictive of good long-term renal outcome.

Adolescent↗
PubMed2004

Intraocular inflammation in autoimmune diseases.

BACKGROUND: The uveal tract represents the vascular organ of the eye. In addition to providing most of the blood supply to the intraocular structures, it acts as a conduit for immune cells, particularly lymphocytes, to enter the eye. Consequently, the uveal tract is represented in many intraocular inflammatory processes. Uveitis is probably a misnomer unless antigens within the uvea are the direct targets of the inflammatory process. A better term of the condition is "intraocular inflammation" (IOI). OBJECTIVES: To review the presence of IOI in autoimmune diseases, the immunopathogenic mechanisms leading to disease, and treatment. METHODS: We reviewed the English medical literature by using MEDLINE (1984-2003) employing the terms "uveitis," "intraocular inflammation," and "autoimmune diseases." RESULTS: An underlying autoimmune disease was identified in up to 40% of patients with IOI, and included spondyloarthropathies, Behcets disease, sarcoidosis, juvenile chronic arthritis, Vogt-Koyanagi-Harada syndrome (an inflammatory syndrome including uveitis with dermatologic and neurologic manifestations), immune recovery syndrome, and uveitis with tubulointerstitial disease. The immunopathogenesis of IOI involves enhanced T-cell response. Recently, guidelines for the use of immunosuppressive drugs for inflammatory eye disease were established and include: corticosteroids, azathioprine, methotrexate, mycophenolate mofetil, cyclosporine, tacrolimus, cyclophosphamide, and chlorambucil. New therapies with limited experience include the tumor necrosis factor alpha inhibitors, interferon alfa, monoclonal antibodies against lymphocyte surface antigens, intravenous immunoglobulin (IVIG), and the intraocular delivery of immunosuppressive agents. CONCLUSION: An underlying autoimmune disease was identified in up to 40% of patients with IOI. Immunosuppressive drugs, biologic agents, and IVIG are employed for the treatment of IOI in autoimmune diseases.

Autoimmune Diseases↗
PubMed2004

Pericarditis following permanent pacemaker insertion.

BACKGROUND: The appearance of pericarditis following insertion of a permanent pacemaker is not widely acknowledged in the literature. OBJECTIVES: To describe our experience with pericarditis following 395 permanent pacemaker implantations over 2 years. METHODS: We retrospectively reviewed the medical records of 395 consecutive patients in whom new pacing systems or pacemaker leads had been implanted over a 2 year period. We searched the records for pericarditis that developed within 1 month after pacemaker implantation according to the ICD-9 code. The incidence, clinical picture, response to treatment, and relationship to lead design and location were studied. RESULTS: Eight cases (2%) of pericarditis following implantation were detected. Clinical manifestations in all patients were similar to those of post-pericardiotomy syndrome and included chest pain (n = 7), friction rub (n = 1), fever (n = 2), fatigue (n = 2), pleural effusion (n = 2), new atrial fibrillation (n = 2), elevated erythrocyte sedimentation rate (n = 4), and echcardiographic evidence of pericardial effusion (n = 8). All affected patients had undergone active fixation (screw-in) lead implantation in the atrial position. The incidence of pericarditis with screw-in atrial leads was 3% compared to 0% in other cases (P < 0.05). CONCLUSIONS: Pericarditis is not uncommon following pacemaker implantation with active fixation atrial leads. Special attention should be paid to identifying pericardial complications following pacemaker implantation, especially when anticoagulant therapy is resumed or initiated. The use of passive fixation leads is likely to reduce the incidence of pericarditis but this issue should be further investigated.

Adrenal Cortex Hormones↗